# Crack;Bottlehead OTL



## ironbut

Maybe the subject heading is a little confusing for folks that aren't used to Doc Bottlehead's tendency for naming his DIY kits a little differently than the run of the mill audio company. 

 Doc's just announced a new OTL headphone kit called "Crack". If you've ever been interested in developing some soldering skills and learn about what's going on inside of a tube amp, Bottlehead kits are a great place to start.
 The fantastic part about this all tube design is the whole kit just costs $200!

 While I haven't heard this amp yet, I do know Doc pretty well and nothing that isn't pretty special gets past the prototype stage.

 Here's a link to the details.

Crack OTL Headphone Amplifier Kit


----------



## oldskoolboarder

Dang you. I already have a S.E.X. amp that is HEAVEN with my HF2s. I bought it used. It'd be interesting to build my own...

 Too bad we didn't have one at the last meet in Burlingame to check out.


----------



## Uncle Erik

Very, very cool! I might have to order one for the hell of it. Not that I really need another amplifier.


----------



## ironbut

I know what you mean Uncle Eric! I need another tube headphone amp like another hole in the head but it's such a nice simple design that it begs to be modified.

 One thing I really like about Doc's kits are the instruction manuals. Not only are the easy to follow but they usually explain a lot of the operating principles.
 The Bottlehead forum is killer too since they have a forum for each current production product so you can share ideas and the results of any mods.

Bottlehead Forum - Index


----------



## jpstereo

Wow. This looks like an interesting option and relatively easy project. I may have to consider this!


----------



## atbglenn

Looks great. I might be ordering one soon!


----------



## mrarroyo

Man, that is an enticing amp. But like some of you I need another amp like a hole in the head!


----------



## Skylab

Same here - just can't do it, but this is VERY cool, and a great place to point people who want to build an amp for cheap.

 Interesting he says he "thinks" you can use a 6AS7 - the 6080 and 6AS7 are electrically identical, so you CAN use a 6AS7. The others are in fact different to varying degrees from the 6080/6AS7, so indeed maybe they would not work. I've owned a lot of 6AS7-based amps, and all of them have tolerated the 5998, since it actually draws slightly less current than a 6AS7G. The 6528, OTOH, draws twice the heater current of a 6080/6AS7G, so that might be a no-no here. But IME it's a crappy sounding tube anyway.

 Sorry for the tube digression. This looks like a cool offering, though!


----------



## Spareribs

love the design! Tempting


----------



## Doc B.

Hi Skylab,

 Yes of course you are right, the 6AS7 and 6080 are interchangeable. The context of that sentence in my product description is a little shaky, isn't it? And you are correct that the 6528A won't work, my flub. I gotta remember to wear my readers when I look at those tube manuals! 

 This puppy was done partly as an exercise to see just how quickly and efficiently we could get a project from the hand waving phase to the production prototype phase, and consequently there just hasn't been enough time to try everything in terms of tube types and circuit mods that we would like to try. 

 I'm happy to answer questions anyone might have about how we're running the prototype, but I don't want to wear out my welcome here with what might be perceived by some as a bunch of unsolicited marketing hype. I'll document the upgrades we develop as they happen over on the Bottlehead Forum. IME Head-Fi'ers are a super bunch and you are all most welcome to come visit.


----------



## nikongod

Hi Doc

 Any thoughts on cutting the top panel for an octal socket and shipping with one of those little adapters & noval sockets like on the foreplay?

 Edited/added:
 I have not seen internal pics, are they up anywhere?

 Edited a second time:
 The photos are up on the bottlehead site :facepalm: Great news, there is room for smallish OPT's


----------



## aristos_achaion

This is perfect...I'd been really wanting a Bottlehead kit, but couldn't justify springing for the SEX yet. And was sitting on a pile of nice 12AU7's since I sold my EF1. And have several high-impedance headphones.


----------



## Doc B.

Quote:


  Originally Posted by *nikongod* /img/forum/go_quote.gif 
_Hi Doc

 Any thoughts on cutting the top panel for an octal socket and shipping with one of those little adapters & noval sockets like on the foreplay?_

 

I would like to have added that potential for mods. A good part of the reason we can put this kit out for a reasonable price is that we were able to employ an existing power transformer (designed by Bottlehead's chief engineer, Paul Joppa, and made in the US) that we have made for us in quantity. That big ol' 6080 heater sucks up a lot of current and the power trans is running pretty much at the design limit current-wise with the addition of the 300mA heater draw of the 12AU7. We felt that the additional 300mA current draw of the most likely octal candidate, 6SN7, would tax it. 

 Also the addition of the adapter would raise the kit price and, though it doesn't always make sense, sometimes one is at the mercy of marketing psychology when it comes to choosing a price point. In the current economic climate I have been reminded of Bottlehead's roots as a maker of bang for the buck stuff. 

 That said, a person could probably figure out a way to enlarge the existing hole if they had an octal candidate in mind with a 300mA heater current draw. We have a CNC machine here in the lab and we might be able to rework a few of the laser cut plates, but the machine is so busy running as an engraver for our other business that I don't foresee being able to reconfigure it anytime soon. Another option is to have a custom plate made by Front Panel Express. We use them for all of our prototypes.


----------



## ulyses

Based on the output explanations I assume this otl design not very suitable for low impedance phones like k702, isn't it?


----------



## Doc B.

There are a couple of threads going at once about this kit in different forums. Forgive me if this seems redundant to anyone following both threads - in the other one I mentioned that yes, this is really intended for high impedance cans, but it will work with low impedance cans though not optimally. I also mention that we have another kit with a low output impedance that works very well with low impedance headphones, so I felt we could afford to do this second, more focused design for the high impedance phone users.


----------



## ulyses

The other kit must be s.e.x I guess. It really looks great, but not so cheap and simple to build unfortunately.


----------



## roger_s

I absolutely don't need another amp. I ordered mine yesterday. I've built a few Bottlehead kits. Great folks to do business with and killer products.


----------



## TheAudioDude

I've always wanted to build a Bottlehead amp, even way back about six years ago for my 2-channel setup. Right now I'm pretty content with my WA22, but perhaps one day...
	

	
	
		
		

		
		
	


	




 I'll have to modify the chassis and install a female 4-pin XLR connector.


----------



## flatmap

I have been specifically avoiding buying more stuff. However I saw this thread, looked at the amp description, and bought it instantly. What happened...? My analysis: one of those had-to-have-it moments where the object in question is so ideally affordable.

 And -- being a head-fi zombie in good standing -- if it doesn't work with my current 'phones then more's the reason to buy another pair!


----------



## roger_s

Over on the Bottlehead forum Doc B. says they've had to double their order of top plates. Not bad at all. Looking forward to putting one together.


----------



## ironbut

One of the really cool things about these kits is, once you have the stock amp working and get a handle on the way it sounds, you can modify them very easily. Doing upgrades one step at a time is very affordable and you'll learn what mods tickle your particular fancy (or your favorite cans).

 None of that paying an arm and a leg and waiting for months for your amp to come back. And if something doesn't go right, no big deal. There's a forum full of helpful folks that'll help you get it going again.


----------



## lextek

Looks like an fun project. Wish there was an option for low imp cans.


----------



## igotyofire

I have only built a cmoy, i wonder if im capable of doing this amp & do the tubes come with it? Also does anyone know what other amps this design compares too?


----------



## Skylab

Can't answer the first question, but yes, tubes do come with it. And while I'm not sure how similar the circuits are, I'm guessing it's so different from the Darkvoice 336 or Woo WA3, which both use a single 6AS7/6080 power tube (although the DV336 uses a 6SN7 driver and the WA3 a pair of 6DJ8's).


----------



## igotyofire

well i think im willing to give it a shot, It doesn't look like there is too many parts to it, So might be doable at my skill level, but i really dont see the point in ordering this early. Unless after the first shipment they are going to be on back order. So im assuming no drilling required, all the holes for tube, volume knob....etc are provided.(what are those white things that say X1CON)

 All i have is my senn hd600's and my 600ohm dt880s, So im not sure If my Bravo or My maverick is doing either of them full justice since most people here have much costlier amps. but this Crack Amp looks like the the other amps that would cost one somewhere in the $400-$500 range. which is why this thing as kinda got my full attention at the moment


----------



## roger_s

No drilling required and all of the parts are supplied. You supply the solder, soldering iron, wire strippers, screwdrivers, etc. and the sweat equity. You also have to assemble the wood box the chassis sits on and apply the finish of your choice. 

 The white things are 3k ohm 10 watt resistors that tie the tubes (don't know if it's the plates or the grids) to ground.

 Bottlehead is pretty much a mom and pop shop. Thus everything is on backorder most of the time. They will take your order, charge your card, get the components and ship it to you in a few weeks. They are VERY up-front about that. No or very low inventory is how they keep their prices low. There are times when they have inventory but that's not usually the case. I've bought a few of their kits and have always been treated well. Good folks that sell good stuff.

  Quote:


  Originally Posted by *igotyofire* /img/forum/go_quote.gif 
_
 well i think im willing to give it a shot, It doesn't look like there is too many parts to it, So might be doable at my skill level, but i really dont see the point in ordering this early. Unless after the first shipment they are going to be on back order. So im assuming no drilling required, all the holes for tube, volume knob....etc are provided.(what are those white things that say X1CON)

 All i have is my senn hd600's and my 600ohm dt880s, So im not sure If my Bravo or My maverick is doing either of them full justice since most people here have much costlier amps. but this Crack Amp looks like the the other amps that would cost one somewhere in the $400-$500 range. which is why this thing as kinda got my full attention at the moment_


----------



## Doc B.

We have indeed decided to keep Bottlehead more or less a mom and pop kind of deal over the years, though there are actually seven people who work in various aspects of the business these days. We just initiated some new project management software this week, and our tentative ship date for the the first Crack kits in that program worked out to April 7. That date is not cast in stone as we are at the mercy of our jobbers, in particular our laser cutter. They usually take about three weeks to get our order shipped, but they do have backlogs and sometimes it can take a bit longer.


----------



## Doc B.

Quote:


 but i really dont see the point in ordering this early. Unless after the first shipment they are going to be on back order. 
 

I can't say for sure how things will go timing-wise on a second run, but I can tell you that we have already doubled our parts orders for the first run based on the number of pre-orders we have been getting, and as of today we only have ten kits not spoken for in that first run. Tech Shawn spent a day sorting through my stash of old stock 6080s with a TV-10 tube tester, and I think we should have enough to cover the first run of kits. After those run out we will be buying new stock Russian tubes and there will be a price increase necessary to cover the cost of the tubes.


----------



## unl3a5h3d

Couple of questions. 1) Does it come with the case? 2) Is there another way to mount the RCA jacks so they aren't standing straight up? Thanks.

 EDIT: I found the answer to both. Sorry for the lack of research.

 I am really liking the looks of this thing. I saw in one of the questions that a balanced one would be a lot more, but could you not buy two of these and make a balanced?


----------



## Doc B.

Small correction, make that seven kits left from the first run as of this afternoon.


----------



## mteinum

Nice project!

 Doc, let say you want to upgrade the volume pot with a ELMA type (I have the ones from goldpoint in mine Foreplay III) how many k ohms are suited for this kit?


----------



## Doc B.

We use a 100K ohm stereo pot. While we are on the subject, some pots and switches have slightly different locations for that little lug that keeps the body from spinning, and sometimes you might need to do just a bit of file work at one side or the other of the stock lug hole in the chassis to allow the index lug of a non-stock pot or switch to fit. IIRC the Goldpoints are like that. Very nice attenuators, well worth with that small bit of extra work. Of course they do cost about 3/4 as much as the Crack kit.


----------



## igotyofire

sweet will be ordering very soon


----------



## burgunder

If only I had some high impedance cans I would order this ASAP.


----------



## igotyofire

Quote:


  Originally Posted by *burgunder* /img/forum/go_quote.gif 
_If only I had some high impedance cans I would order this ASAP._

 

hmmz i know in my cmoy build u could change the gain by changing resitors....seems like that would be the case here as well if someone really wanted this kit opposed to the sex kit


----------



## dongringo

I just ran across the Crack while browsing the links on the MAD site and just had to have it so ordered it right away. This will be my first build and it doesn't seem as overwhelming as most DIYers I've been looking at. Plus, after finishing the body black laquered it will match my Ear+ nicely. This is going to be fun.

 EDIT: Where is Bottlehead located? Can't seem to find it anywhere. I don't even know where my amp will be coming from. lol


----------



## Steve Eddy

Quote:


  Originally Posted by *dongringo* /img/forum/go_quote.gif 
_EDIT: Where is Bottlehead located? Can't seem to find it anywhere. I don't even know where my amp will be coming from. lol_

 

Place called Poulsbo. Next state up from you. 
	

	
	
		
		

		
			





 se


----------



## dongringo

Quote:


  Originally Posted by *Koyaan I. Sqatsi* /img/forum/go_quote.gif 
_Place called Poulsbo. Next state up from you. 
	

	
	
		
		

		
		
	


	




 se_

 

Thanks, just looked it up. Wow, so close.


----------



## igotyofire

still trying to think of a finish for mine as well


----------



## Steve Eddy

Quote:


  Originally Posted by *dongringo* /img/forum/go_quote.gif 
_Thanks, just looked it up. Wow, so close. 
	

	
	
		
		

		
		
	


	


_

 

Yet so far away.

 At least until it finally shows up on your doorstep. 
	

	
	
		
		

		
		
	


	




 se


----------



## dongringo

@Koyaan haha "yet so far away" you aren't kidding.

 Does anyone know if it is recommended to paint the aluminum chassis and top of the power supply and, if so, what kind of paint would work? I was thinking maybe car paint.


----------



## roger_s

Take a look at the Gallery at the Bottlehead Forum. Some pretty cool builds to get a bit of inspiration from.

  Quote:


  Originally Posted by *dongringo* /img/forum/go_quote.gif 
_@Koyaan haha "yet so far away" you aren't kidding.

 Does anyone know if it is recommended to paint the aluminum chassis and top of the power supply and, if so, what kind of paint would work? I was thinking maybe car paint._


----------



## dongringo

Quote:


  Originally Posted by *roger_s* /img/forum/go_quote.gif 
_Take a look at the Gallery at the Bottlehead Forum. Some pretty cool builds to get a bit of inspiration from._

 

Thanks 
	

	
	
		
		

		
		
	


	




 Well that answered my questions. Lots of good ideas there. Good stuff!


----------



## igotyofire

todays the 7th.....shipped? (crosses fingers)


----------



## igotyofire

Im feenin man! feenin!......i got these cheese burgers man


----------



## nikongod

Quote:


  Originally Posted by *igotyofire* /img/forum/go_quote.gif 
_todays the 7th.....shipped? (crosses fingers)_

 

The bottlehead shipping page says they start shipping "around" tomorrow. 

 Im psyched too!


----------



## Doc B.

Quote:


 The bottlehead shipping page says they start shipping "around" tomorrow. 
 

We had intended to start shipping Monday, but we discovered that tbe hookup wire we were sent was stranded and the kit uses solid core wire (which is much easier to work with). The solid wire is on its way, and we will begin shipping just as soon as it shows up.


----------



## tdogzthmn

I am looking to buy one of these amps to build with my grandfather who recently started suffering from depression. He used to wire submarines in WWII so he has electrical experience. I figure this would be a good way to engage his mind and have some fun! I just need to save up for it first.


----------



## tdogzthmn

Have any Head-fies ordered one of these? I would like to know some impressions once you get it built. I plan to use it with a DT880, hope they make for a good match.


----------



## dongringo

Quote:


  Originally Posted by *tdogzthmn* /img/forum/go_quote.gif 
_Have any Head-fies ordered one of these? I would like to know some impressions once you get it built. I plan to use it with a DT880, hope they make for a good match._

 

I ordered one from the second run so it will be awhile before I receive it. I also got it to pair with the DT880, the 600 ohm version.

 I think it's a great idea to build it with your grandfather. Would be a nice experience to share together.


----------



## roger_s

I got my shipping notice today. UPS alleges it'll be here Friday. Yay! Solder fumes!


----------



## Todd R

Ordered mine early on. Hope I'm in the 1st run. 
 Well see....


----------



## ironbut

Got mine!
 I'm fooling with some cosmetics before I put it together but I should be able to give some early impressions by the weekend.


----------



## tdogzthmn

Quote:


  Originally Posted by *ironbut* /img/forum/go_quote.gif 
_Got mine!
 I'm fooling with some cosmetics before I put it together but I should be able to give some early impressions by the weekend._

 

Sweet, I'm excited to hear what you think. I wonder when the 'speedball' upgrade will be released?


----------



## orkney

Ordered mine. During the wait I'm going to practice by carefully soldering the local invasive red squirrel population to the freshly-repaired eaves of my house.

 o


----------



## Todd R

Got mine today. 
 Glued the base together & primer the top plate. 
 Hmm...
 Maybe I should post pictures as I go?


----------



## tdogzthmn

Quote:


  Originally Posted by *Todd R* /img/forum/go_quote.gif 
_Got mine today. 
 Glued the base together & primer the top plate. 
 Hmm...
 Maybe I should post pictures as I go?_

 

That would be cool!


----------



## roger_s

Mine arrived. The process of voiding the warranty begins: Different pot, different 'phone jack (locking Neutrik), and different coupling caps.


----------



## ironbut

By ironbut at 2010-04-24




 By ironbut, shot with Canon PowerShot A590 IS at 2010-04-24

 A couple of photos of my completed (dead stock) Bottlehead Crack OTL. 
 I polished the chassis plate and painted the transformer bell. I'm pondering some fancy-dancy stuff for the base so that could take a bit longer.

 With just an initial listen, it's kinda shocking how good this thing sounds. Right now I'm using my AT AD2000's which aren't ideal impedance wise, but if you notice, the volume pot is at about 9 o'clock and it's plenty loud. I'll run it dead stock for at least a couple of weeks to get it's measure with several cans, but I couldn't be happier with this little amp. 
 What a freakin' bargain!

 BTW, I screwed around with the cosmetics on Thursday, put it together on Friday, did the final tests this morning (there were a couple of typos in the manual,.. at least it seemed like it to me,.. so find out for sure before you start soldering) and now I'm burning it in.


----------



## roger_s

Great looking amp and I'm glad to learn that it sounds great as well. How'd you polish the top plate? And how'd you polish it so fast? Mine's primed and painted.


----------



## ironbut

Quote:


  Originally Posted by *roger_s* /img/forum/go_quote.gif 
_Great looking amp and I'm glad to learn that it sounds great as well. How'd you polish the top plate? And how'd you polish it so fast? Mine's primed and painted._

 

Unfortunately, I have lots of experience in fine finishing from working on hardwoods mostly. 
 I try not to waste any time and start very aggressively.
 Of course, wear ear, eye and breathing protection.

 I started by mowing off the wire brush scratches with some "Sandblaster" 120 grit (I think it's a 3M product) on a palm sander. That stuff is hell on wheels and if you used it on wood, it could gouge in an instant but for removing some mil's on metal, it's great. 
 It does leave major swirl marks so I then went down to 150 grit aluminum oxide then 320 grit. All that took me about 1.5 hours. The last sandpaper I used was some more 320 grit that I rubbed against each other and that makes it closer to 1000 grit.
 With each grit, stop after a few minutes, wipe off the surface with a rag and look to see what "new" swirl marks you're making and what you're getting rid of. It doesn't pay to go any further than the grit will allow.

 After the sandpaper, I cut up some rags into squares and put them on the sander. I smear "Mother's Aluminum and Mag Polish" (at your auto parts store) and polish it till most of the sanding swirls are gone. This means every 10 minutes or so, you need to clean off the polish and take a soft clean rag and polish. You'll be able to see when most of the sandpaper swirls are gone and just the very fine polishing swirls are being created now.

 When you get to the point that you aren't making any progress, take a foam car wax applicator (I like Meguires), apply a light coating of the Mag polish and using a very light touch in circular motions, get rid of as much of the swirling as you can. 
 Polish it with clean, soft cloths and wash with 409/fantastic type cleaners and water. Examine closely at every angle.
 If you weren't super careful, you may find marks from earlier sandings. In this case, it's better to just give up and go back to that point in the polishing rather than wear your arm off trying to get it with too light a finishing stage.

 I then put clear gloss lacquer to protect the polishing (it'll scratch by just looking at it if you don't). If it's a flat surface like this plate, I flood it on in one coat (just short of dripping off the edges). Of course, keeping everything totally clean and dust free is key to the final finish you'll get.
 Wear a respirator if you value your brain cells too.

 I guess I spent about 3.5 hours doing this and painting the transformer bell.

 This process won't yield a totally mirror finish but this isn't silver we're working with. You can totally remove any swirls by using the compounds that are used to polish the mirrors in reflecting telescope kits (Edmund Scientific) but I don't think it's worth the extra time.


----------



## igotyofire

wow so how long did it take to build it minus the metal finishing?


----------



## ironbut

Hmm, I guess if I'd worked on nothing but the Crack amp,.. ,maybe 6-7 hours.
 Unfortunately, between watching TV, fooling with another amp, cooking dinner, doing some sketches of the base design and daydreaming about sex, it's kinda tough to get an exact figure.

 A couple of things that I found handy was, a pair of lineman's pliers to hold and trim stuff (one of the terminal bases butted up against a tube socket so I could clip off the end a bit). I have a cheap one I got at Home Depot that comes in handy for all kinds of stuff,.. it's the blunt end of the stick.
 I double stick taped a ruler to my desk so I didn't have to search for it for the gazillion wire cuts you have to make.
 A small file set. The power switch hole was very tight (maybe all that lacquer?) so a few swipes with a file helped. 

 I guess I was on kind of a mission but if I'd spread it over more than one day, it would've been a relaxed easy job.


----------



## Todd R

Quote:


  Originally Posted by *roger_s* /img/forum/go_quote.gif 
_Great looking amp and I'm glad to learn that it sounds great as well. How'd you polish the top plate? And how'd you polish it so fast? Mine's primed and painted._

 

It looks great. 
 Primed & painted mine today. Kind of sorry now.


----------



## ironbut

Viva la difference!
 I've seen some fantastic looking Bottlehead plates that are painted and what I did certainly isn't the easy way. I've just done it enough so each time it gets a little easier and the finishes are a little better.
 There's a lot of iffy results behind me.


----------



## Lil' Knight

Looks very nice, ironbut.

 Just wondering how it compares with your other amps?


----------



## ironbut

Quote:


  Originally Posted by *Lil' Knight* /img/forum/go_quote.gif 
_
 Just wondering how it compares with your other amps?_

 

Any real comparisons are a long way off I think. Aside from burn in time, my other amps (currently in use at least) have the advantage of finding just the right combo of tubes and cables to optimize them for a particular headphone (for the most part, I only use one headphone per amp or set up).
 I do have a couple of amps in my gear list that I don't really use very often (ASL Mg Head OTL and Eddie Current EC-01). Having the Crack will keep me from ever using them again.


----------



## tdogzthmn

Quote:


  Originally Posted by *ironbut* /img/forum/go_quote.gif 
_Any real comparisons are a long way off I think. Aside from burn in time, my other amps (currently in use at least) have the advantage of finding just the right combo of tubes and cables to optimize them for a particular headphone (for the most part, I only use one headphone per amp or set up).
 I do have a couple of amps in my gear list that I don't really use very often (ASL Mg Head OTL and Eddie Current EC-01). Having the Crack will keep me from ever using them again._

 

I would like to know how the crack sounds with your DT880. I am planning to build one and will either use it with my DT880 (250 ohm) or maybe get an HD600 again.


----------



## ironbut

I won't be home tomorrow but I'll give the DT880's a listen on Monday and post something then.
 I have a feeling from the way they sounded with my AD2000's that it should be a really nice pairing.


----------



## dannie01

Great work ironbut on the Crack. It looks awesome. Would you mind to take some pics of the soldering work inside, thanks?


----------



## roger_s

Thanks for the detailed reply! I'll have to give polishing a try on whatever my next Bottlehead project is.


----------



## ironbut

Just to emphasize the point (it was kinda low in my other post), there are a couple of typo's in the first run of the assembly cd. Doc knows and will be doing corrections on these Monday but if you're hot and heavy into assembly already, you should check out this thread on the Bottlehead forum.

 BTW the resistance checks won't pass without the corrections and it should be needless to say, don't do the voltage checks if the the ohms don't jive.

I swear baby, this has never happened before (please help me, Crack won't work)


----------



## Todd R

After fixing those 2 wiring mistakes the Crack is running. 

 Played for about an hour tonight and it sounds pretty good (HD-650).
 Even though it uses the same 6080 tube that the Wheatfield HA-2 I used to own does, it sounds cleaner & more detailed than the HA-2, but not quite as rich. 

 I'll try to see if I can get picts of my build progress up tomorrow sometime.


----------



## ironbut

As usual, Doc hopped on getting out the manual corrections as soon as the office was open. Great customer service!

Crack Manual - corrections for the kits shipped the week of 4/19

 I did get a chance to listen to my DT880's this morning. I think this amp has given them the bass that I always felt was somewhat lacking. Needless to say, the Crack had no problem driving these to ear shattering levels with my laptop>Metric Halo. The highs were a little edgy but there's lots of burning in still to do not to mention a world of upgrades that should clean those up with very little cash.
 I'm still totally shocked by what this ultra simple circuit will do!
 Kudos to Paul Birkeland and the rest of the Bottlehead design team. With this amp, I don't see any reason why new headphone fans can't have a great sounding rig right off the bat.


----------



## mrarroyo

Todd, will you be getting the upgrades that are being planned for the Crack?


----------



## Todd R

Quote:


  Originally Posted by *mrarroyo* /img/forum/go_quote.gif 
_Todd, will you be getting the upgrades that are being planned for the Crack?_

 

If I can afford them. (Living off eBay right now)


----------



## ironbut

I broke my word and did a couple of minor upgrades last night. Just signal wire so far (I tried using a TKD pot I had on hand but it was toast,.. literally since it was in a little amp fire I had!). Shielded Cardas 24AWG and solid silver 21AWG from Michael Percy since it was just sitting in my wire bin begging to be used. 
 That seemed to smooth things out and bring out more details just a hair. 
 Of course it could be that everything else is burning in so don't hold me to it.

 I did spend some more time listening to the DT880's just now and this could be a match made in heaven. Great bass, and smooth, crystal clear highs. So far, it doesn't seem to be presenting as good a soundstage as I'm used to with the Beyers but that's usually the last thing to show up with burn in. 
 I was going to sell my 880's but I don't think so anymore.


----------



## Todd R

Ok, here's some pictures: 
 The base glued together.






 Metal parts painted with primer.






 If you're going to use the base to support the plate while you're building, I suggest protecting the wood with some painters tape.






 Installing the hardware. I suggest trimming the front of this bracket as it's very close to the tube mounting socket.






 Hardware all bolted in.






 2 of my favorite amp building accessories. 






 Most of the wiring done (I was on a roll)






 Close up of the 9 pin socket wiring.






 Transformer wiring. 






 Here's something that I like to do on Bottlehead kits. Since the plate just sits in top of the base, I like to drill some holes in the plate, add some mounting blocks so I can screw it down. 





 All done! 
	

	
	
		
		

		
		
	


	









 Probably about 6 hrs work if you take your time, not counting the wood finishing time.


----------



## ironbut

Beautiful job Todd!
 Good idea about the blocks and screws. My Seduction has never had the base finished and the plate just sits on it. Probably not a great idea since I live in earthquake country!
 I'm gonna try and use silicone glue on the Crack eventually but it's so convenient to use the base to work on it, yours is probably the better idea.


----------



## smeggy

looks awesome, shame my phones are only 50 Ohms.


----------



## igotyofire

are the blocks just glued in? seems like they would fall with too much pressure applied


----------



## tdogzthmn

Todd: Looks great, I like the nice navy-blue color.

 ironbut: glad to hear the DT880 pairs well. I hope the amp helps flush out the midrange because I am finding the DT880 to be lagging behind my K271 which has lovely detailed mids.


----------



## Todd R

Quote:


  Originally Posted by *igotyofire* /img/forum/go_quote.gif 
_are the blocks just glued in? seems like they would fall with too much pressure applied_

 

Yes, glued with Elmer's carpenters glue. I dare you to try & tear them out. You can't


----------



## atbglenn

Quote:


  Originally Posted by *Todd R* /img/forum/go_quote.gif 
_Yes, glued with Elmer's carpenters glue. I dare you to try & tear them out. You can't 
	

	
	
		
		

		
		
	


	


_

 

With Elmer's Carpenter's Glue, the bond is actually stronger than the wood itself. 

 BTW, Your amp look great. Nice color choice


----------



## ironbut

One very cool thing that no one's mentioned are the tubes that are being supplied with the Crack kit. I've got a bunch of nice tubes in my stash but nothing like Bottlehead Central.
 The "tube lottery", as Doc likes to call it, supplies really nice NOS tubes to lucky customers and, unlike every other company I can think of, doesn't just give you a bunch of new production crap that's hardly worth the space they occupy. 
 I've got a stack of 12au7 types waiting in the wings to try with this amp, but so far, I haven't rolled one yet.
 If you've been into tube rolling for long, you'll realize that some highly regarded tubes will cost more per pair than this entire kit!


----------



## dannie01

Great work Todd, your Crack looks a very nice built.


----------



## igotyofire

mine comes tomorrow, so hopefully i will have it built this weekend, I think im going to try and stain the wood as well as this is somthing ive never done b4.


----------



## Todd R

Quote:


  Originally Posted by *dannie01* /img/forum/go_quote.gif 
_Great work Todd, your Crack looks a very nice built._

 

Thanks a lot. 
 FYI if you don't visit the Bottlehead forum often, there are 2 important wiring changes to the kit that you will need to correct if it wasn't done in your manual. 
Wiring changes,


----------



## Todd R

Quote:


  Originally Posted by *igotyofire* /img/forum/go_quote.gif 
_mine comes tomorrow, so hopefully i will have it built this weekend, I think im going to try and stain the wood as well as this is somthing ive never done b4._

 

It's easy. 
 Personally I would avoid those products that are stain & sealer all in one. I never had good results with those.


----------



## ironbut

I got around to putting a finish on my base yesterday. I routed a little pattern in the front with my Dremel, sanded the crap out of it, applied stain controller, mixed some cherry and dark mahogany gel stain, then applied a bunch of coats of sanding sealer and lacquer. Not perfect but good enough for now.





 By ironbut at 2010-04-29





 By ironbut at 2010-04-29


----------



## tdogzthmn

Any more impressions?


----------



## mrarroyo

Todd that amp looks great, same with yours ironbut.


----------



## igotyofire

going to start working on mine now, im sure im going to have alot of questions and comments as this will be the most complicated thing ive ever built, going to try using gorilla glue for the base since thats what i have lying around,figure once its together then i can start the light sanding & stain process


----------



## ironbut

One detail of the building of this amp that some might skip (or in my case, forget) is putting the feet on the bottom of the base. It might seem kind of trivial but I find that the top plate stays much cooler with this ventilation.

 Properly ventilating amp cases is something that I've found is often skipped with commercial builds. In some cases, it's for aesthetic reasons which I can sort of understand, but getting components too hot shortens their useful lives.
 And with some components, their values can even change with extremes in temperature.
 So, don't forget the feet. Your amp will appreciate it.


----------



## Todd R

Quote:


  Originally Posted by *tdogzthmn* /img/forum/go_quote.gif 
_Any more impressions?_

 

Yeah, 
 I'm pretty impressed with how good it sounds. I swapped in my Sylvania 7236 and got even more improvement. The original tube was a touch polite sounding. 
 I might bring it to CanJam if someone would let me sit it on their table.


----------



## nikongod

Im anxious to get cracking on my crack build, but one of my pieces of wood came chipped. I emailed bottlehead and they said they would get a new piece out for me ASAP. IME there is noting that a shipping service can not screw up, and bottlehead was nice enough to fix it nice and quick. I suppose they should be here Monday or Tuesday.

  Quote:


  Originally Posted by *Todd R* /img/forum/go_quote.gif 
_Yeah, 
 I'm pretty impressed with how good it sounds. I swapped in my Sylvania 7236 and got even more improvement. The original tube was a touch polite sounding. 
 I might bring it to CanJam if someone would let me sit it on their table._

 

I dont know how things are going to go this year, but there was basically a DIY room at last year's can-jam. for sure someone will have room to plop the amp down. Bring your own y-splitters 
	

	
	
		
		

		
		
	


	




 Id for sure let you share a table, but I'm bumming from someone else at the moment (and I dont even know who yet!).


----------



## ironbut

Quote:


  Originally Posted by *Todd R* /img/forum/go_quote.gif 
_Yeah, 
 I'm pretty impressed with how good it sounds. I swapped in my Sylvania 7236 and got even more improvement. The original tube was a touch polite sounding. 
 I might bring it to CanJam if someone would let me sit it on their table._

 

That would be very cool if you could bring it. I still haven't made up my mind if I'm going to drag any gear along with me. 

 I put a nice mid 50's CBS Hytron 5814 in mine yesterday and I'm lovin' it. 
 BTW what tubes are you guys getting with your kit? Mine came with an RCA 6080 and a Toshiba 5963 labeled HP. The Toshiba was a little edgy compared to the Hytron.


----------



## Todd R

I'm sure it's in one of the huge threads, but what was the deal with member tables? How did you get one?


----------



## aristos_achaion

Quote:


  Originally Posted by *ironbut* /img/forum/go_quote.gif 
_That would be very cool if you could bring it. I still haven't made up my mind if I'm going to drag any gear along with me. 

 I put a nice mid 50's CBS Hytron 5814 in mine yesterday and I'm lovin' it. 
 BTW what tubes are you guys getting with your kit? Mine came with an RCA 6080 and a Toshiba 5963 labeled HP. The Toshiba was a little edgy compared to the Hytron._

 

I got a GE 6080 and a bit of a mystery 5963...it's clearly labelled "USA / 5963", but the manufacturer below is mostly rubbed off. I can make out the end of the label as

 ARD
 RCA

 It's got fairly normal-looking plates and a halo getter. The only tube manufacturer I can think of ending in ARD would be Mullard, but would they be making tubes in the US? Or with RCA?

 Anyhow, my very noobish build is nearing completion, so we'll see how it sounds sometime in the next few days (unless, of course, I've screwed the whole thing up, which is very much not impossible).


----------



## ironbut

It could always be another supplier that Hewlett Pack-_ard_ relabeled for use in their equipment.
 They used tons of nice tubes in their test gear. Lots of Amperex 7308/6922 types in fact. After all, the stuff they made would have been used to "test" things like medical equipment that were already as low noise as possible.


----------



## Todd R

Mine came with an RCA 6080. The 12AU7 I have no idea, all the lettering is gone.


----------



## igotyofire

I was reading ahead and was just curious are you guys doing the voltage checks? that seems kinda dangerous & id prefer to only do the resistance check, seems like they accomplish the same thing. as far as determining whats to connected to what & what its measuring at.


----------



## ironbut

If you just keep the same ground as the resistance checks, all you really need to do is touch the indicated terminals with the red probe to do the voltage checks. You just need to be careful not to touch more than one at a time. 
 For the most part, the voltage checks just assures that you're not feeding the high voltage or filament supply to the wrong place. The resistance checks will still be in the right neighborhood even if they aren't.
 Doing the one hand in the pocket will keep you out of trouble even if you do get zapped (in other words, don't ground your free hand).


----------



## ironbut

Quote:


  Originally Posted by *Todd R* /img/forum/go_quote.gif 
_I'm sure it's in one of the huge threads, but what was the deal with member tables? How did you get one?_

 

I was looking for one myself. They usually have a "Sign Up" thread going once they have some kind of table map penciled in.
 I haven't noticed an official "Vendor list" thread posted yet either. 
 I would imagine that those are some of the things that go into those "reserved" posts at the beginning of the main thread.
 Last year, the table sign ups didn't begin till pretty late too.


----------



## aristos_achaion

What's the best way to contact Bottlehead? I managed to break off one of the leads of one of the 3KOhm resistors, and need to see if I can order a replacement.

 Also, does anyone know a good source for such a resistor? I'm a bit hesitant to order just one resistor from, say, Mouser...it seems like that would kill me on shipping.


----------



## Todd R

Quote:


  Originally Posted by *aristos_achaion* /img/forum/go_quote.gif 
_What's the best way to contact Bottlehead? I managed to break off one of the leads of one of the 3KOhm resistors, and need to see if I can order a replacement.

 Also, does anyone know a good source for such a resistor? I'm a bit hesitant to order just one resistor from, say, Mouser...it seems like that would kill me on shipping._

 

The forum is good for quick question answers.
E mail or phone them.


----------



## Doc B.

The Queen and I were away for the weekend, but we're back in the office today. Give us a ring and we will take care of you, 360-697-1936. Or you can email Eileen at queen at bottlehead dot com. While I have your attention, it just clicked in my fuzzy old brain that CanJam is in Chicago next month. My family has a condo in Chicago, so Eileen and I are thinking of coming out for the event. Would folks be interested in having Crack and S.E.X. at CanJam?


----------



## nikongod

I would like to have sex and crack at canjam.


----------



## Todd R

Quote:


  Originally Posted by *Doc B.* /img/forum/go_quote.gif 
_While I have your attention, it just clicked in my fuzzy old brain that CanJam is in Chicago next month. My family has a condo in Chicago, so Eileen and I are thinking of coming out for the event. Would folks be interested in having Crack and S.E.X. at CanJam?_

 

That would be so awesome if you two showed up.


----------



## ironbut

Hey Doc,
 It would be very cool to see Eileen again,.. and you could tag along too!
 Just kidding. I think it would be fantastic. 
 You know how it goes at these things, you should be prepared to have every headphone ever made plugged into each. 

 What would be really-really fantastic is if you could bring a Crack with the Speedball and any other upgrades you've come up with so we can hear the difference.


----------



## ironbut

If you guys haven't popped over to the Bottlehead forum today, the pre order/order page is up for the Speedball upgrade kit.
  Get um while you can because just like the Crack, it's gonna sell out fast!
   
  http://www.bottlehead.com/store.php?crn=44&rn=446&action=show_detail


----------



## tdogzthmn

Need to get the amp before I can upgrade it.


----------



## Todd R

Quote: 





ironbut said:


> If you guys haven't popped over to the Bottlehead forum today, the pre order/order page is up for the Speedball upgrade kit.
> Get um while you can because just like the Crack, it's gonna sell out fast!
> 
> http://www.bottlehead.com/store.php?crn=44&rn=446&action=show_detail


 
   
  Arrgh! More money flying out of my wallet. (yes I ordered it)


----------



## ironbut

I was wondering if any of you guys have one of those cable rigs that can link two single ended headphone amps to a balanced output?
  If so, I'd love to hear how it would sound with a balanced pair of HD800's. I've listened to those cans on several rigs and it really seemed to come alive when it was driven balanced.
  With CanJam just around the corner, I'm sure we could get a couple of Cracks together in Chicago.
  So,.. what I'm wondering is if one of the "ultimate" amps for the HD800 is a DIY , $400 amp?


----------



## tdogzthmn

Has anyone been able to compare this amp with others in a similar price range?


----------



## milosz

Just what I need, YET another headphone amp!  So, *OF COURSE* I ordered one, with the Speedball upgrade.  It'll be nice to listen to these when I end up living in a van down by the river because I couldn't pay my rent......
   
  I have built a Bijou, which is a very nice sounding OTL tube amp.  It will be interesting to hear how it compares to the Crack.  
   
  I also have a Little Dot MK III..... and a β22... and etc etc  WAAY too many amps.


----------



## tdogzthmn

What would be a good volume pot to use with this amp?  I am looking at various parts I could upgrade without spending too much.


----------



## milosz

First I would measure how well the existing pot tracks. A pot is simply a variable resistor. A stereo volume control is two pots on one shaft.  To give good performance, the two pots should be at the same level of resistance at any point in the rotation of the volume control.  This keeps the stereo balance accurate at all volume settings.  Unless a pot is REALLY BAD, it is not going to add noise to the signal, and there is no difference is sound quality between a 99 cent surplus bargain pot and a $140 machined metal custom pot.  The difference is that a $25 Alps Blue Velvet pot will have closer to identical  values of resistance between the two pot sections (left and right gain controls) at various points along the pot's rotation.  The Blue Velvet pots also have a nice smooth action that is pleasant to use in terms of ergonomics, and it is made of quality materials that should last longer without wear-related failure.  A stepped switch with hand-selected matched resistors gives the most accurate tracking.
   
  So, if the existing pot tracks pretty well, there is no sonic reason to replace it.
   
  Some people claim they hear differences in resistor types.  However this has never been shown in double-blind tests to the best of my knowledge. (Anyone knows of any such studies, please chime in with a reference- )


----------



## tdogzthmn

Quote: 





milosz said:


> First I would measure how well the existing pot tracks. A pot is simply a variable resistor. A stereo volume control is two pots on one shaft.  To give good performance, the two pots should be at the same level of resistance at any point in the rotation of the volume control.  This keeps the stereo balance accurate at all volume settings.  Unless a pot is REALLY BAD, it is not going to add noise to the signal, and there is no difference is sound quality between a 99 cent surplus bargain pot and a $140 machined metal custom pot.  The difference is that a $25 Alps Blue Velvet pot will have closer to identical  values of resistance between the two pot sections (left and right gain controls) at various points along the pot's rotation.  The Blue Velvet pots also have a nice smooth action that is pleasant to use in terms of ergonomics, and it is made of quality materials that should last longer without wear-related failure.  A stepped switch with hand-selected matched resistors gives the most accurate tracking.
> 
> So, if the existing pot tracks pretty well, there is no sonic reason to replace it.
> 
> Some people claim they hear differences in resistor types.  However this has never been shown in double-blind tests to the best of my knowledge. (Anyone knows of any such studies, please chime in with a reference- )


 

 Good to know, are there other components such as capacitors that have more of an audible difference?


----------



## igotyofire

Still in the assembly phase of mine. Ive been so busy with Work & working on my motorcycle, made a bit more progress today.I think i need to take out the screws and make sure i used the right ones......it looks like the diameter is suppose to be different but i cant tell or is it the pitch?....seems like as long as it fits it should be fine...
   
   
  Here is a quick pic, I smoothed out that aluminum top so it looks good at certain angles and would is stained and has a nice gloss as well at certain angles, but its by no means professional looking under close inspection. First time ever staining wood and slightly polishing metal, heh


----------



## milosz

People say they can hear the difference in capacitors.  I have seen some studies that tends to support this idea, but it really isn't "solid proof" that you can hear the difference.
   
  Some capacitors make a MEASURABLE difference. My Musical Fidelity XCAN v3 had some really cheap filter caps in the power supply; replacing those cheap ones with with quality capacitors with lower ESR made a slight but measurable difference in the the amp's S/N ratio, especially at the top end of the audio band.  And, removing the DC blocking cap off the input and changing the output coupling caps to non-polarized parts with higher capacitance made a _measurable_ improvement in low frequency response.
   
  Coupling capacitors - capacitors that connect the preamp stage to the amp stage, or those that connect the output of the amp to the headphones-  people say that electrolytic caps sound distorted when used in these circuit positions.  The audio is flowing directly through these capacitors, and maybe people can hear differences in sound quality between electrolytic capacitors and polyester or polypropylene film capacitors, or oil-in-paper capacitors.  Certainly these capacitors all differ in certain real, measurable properties like ESR and so on, and so maybe you'll hear differences. However, capacitors rated to handle the high voltages inside a tube amp and capable of the high capacitance values needed in coupling capacitors are expensive.  It seems kind of silly to use $600 coupling capacitors in a $200 amp.
   
  Bypass capacitors can also be important, some say, and most people like film capacitors in this application. It doesn't look to me like the stock Bottlehead Crack amp uses any - or has any need for bypass caps anywhere, though.
   
  Power suppliy filter capacitors should be good quality, low ESR electrolytics, and it looks like the Bottlehead Crack uses good quality parts for this already.
   
  So, I'd say, build the Crack in stock form.  Then, watch the Forums to see what people do to modify them.  See if anyone finds coupling caps that improve the sound.  You could go out and BUY a few hundred dollars worth of exotic caps and experiment yourself to see if any improve the sound.... but I'd guess you have better things to do with your money.
   
  For example, people in the Bijou D.I.Y. tube amp forum have found some oil-based motor starting capacitors to replace the electrolytic output coupling caps and they report that they sound better. These caps can bought off eBay from someone who is selling them to use with motors  and doesn't realize that there are audiophiles out there who think oil-in-paper capacitors are "magic" and will pay silly prices for them.
   
  Another tweak you can do is trying different tubes. There are tubes currently manufactured in Russia and China, and I think the Czech Republic too; maybe you'll like the Chinese tubes and hate the Russian ones.  Also, there are "New, Old Stock"  (NOS) tubes available on the market that have been sitting on some shelf since the early 1960's when tubes were still common.  There were many manufacturers of tubes in the US, England, Holland and Germany in those days.  You might find that the RCA tubes are great, or maybe Telefunken.  Be careful, though, some tubes have gained such a reputation that the prices have shot through the roof- and so there are people out there COUNTERFEITING them!  See http://reviews.ebay.com/Amperex-Bugle-Boy-12AX7-ECC83-preamp-tubes_W0QQugidZ10000000002395429  this guy explains how to spot certain fakes.


----------



## dynasonic

Would this amp work well with Beyer DT-990 600 ohm phones? I know crap about the fundamental laws of electricity but I read this amp works best with high impedance cans, and my cans are 600ohm... that seems pretty high but it doesn't make sense to me as to why a lower power amp works well with something that is harder to drive. Any help would be welcome.


----------



## aristos_achaion

Quote: 





dynasonic said:


> Would this amp work well with Beyer DT-990 600 ohm phones? I know crap about the fundamental laws of electricity but I read this amp works best with high impedance cans, and my cans are 600ohm... that seems pretty high but it doesn't make sense to me as to why a lower power amp works well with something that is harder to drive. Any help would be welcome.


 

 I'm not sure about the electrical reasons for this, but I can tell you that some tube amps have an unacceptably high noise floor with low-impedance 'phones. My SSMH, for instance, sounds terrible out of my SR225's, but sounds great with my HD580s. I'm not sure what, electrically, is making this happen, but from a practical viewpoint, one has a loud hiss in the background and the other doesn't.
  I think 600Ohm is a pretty standard value for "high impedance", so you should be good.


----------



## Shark50521

Quote: 





dynasonic said:


> Would this amp work well with Beyer DT-990 600 ohm phones? I know crap about the fundamental laws of electricity but I read this amp works best with high impedance cans, and my cans are 600ohm... that seems pretty high but it doesn't make sense to me as to why a lower power amp works well with something that is harder to drive. Any help would be welcome.


 

 Very interested in this myself, hoping someone has an answer.


----------



## milosz

The amp works best with higher impedance headphones because the amp is capable of developing more output voltage into a higher impedance.  Lower impedance loads, like Grado headphones, might "load it down" too much, with the result that a listener to the lower impedance headphones might not be able to play music LOUD ENOUGH.  That's the main reason that this unit is said to be more suitable to the typical 300~600 ohm "high impedance" headphones.
   
  I think aristos_achaion's experience might be more likely attributed to the greater efficiency of his Grado headphones when used with a solid state oputput stage like the SSMH. Their efficiency (ability to turn voltage into sound) is high, and so the low voltages of noise on the output stage of his SSMH become audible on his Grados but not his Sennheiser 580's.  It should be noted that the SSMH uses a SOLID STATE output stage which delivers more power into a lower impedance headphone than it would into a higher impedance headphone.  In the SSMH the headphones are not connected to the tubes; the 19J6 tube is a gain stage which increases the voltage of the incoming signal, and the tube passes it's signal on to an IRF510 MOSFET - a type of transistor- which provides the power to drive the headphones.
   
  In the Bottlehead Crack, there is a tube gain stage and a tube power stage.  There are no transistors at all.
   
  Typically, with a tube output stage you will get good highs without solid state "glare" which comes with many transistor amplifiers. However, since the tube has a higher output impedance, it's damping factor is lower and there may be a loss of "tautness" or "control,"  especially in the low end.  This is one reason why tube amps sometimes sound a bit "wooly" on the bass.  These are gross generalizations, however, and a lot depends on the actual circuit and the headphones used with it.  A tube design which does not use an output transformer to couple the headphones to the tube often has very good extension in the bass which can temper the "wooly" lows and result in a sound that is a bit "warm" or "rich" without seeming to have sloppy midbass.  The Bottlehead Crack is such a design.


----------



## tdogzthmn

The output impedance on the amp is 120 ohms so I am wondering is this amp would pair well with the DT 48 E which has a nominal source impedance of 120 ohms although the nominal impedance is rated at 200 ohms.


----------



## Doc B.

Quote: 





> the DT 48 E which has a nominal source impedance of 120 ohms although the nominal impedance is rated at 200 ohms.


 
   
  I have not listened to DT 48 E so I can't give you a subjective answer, but the "nominal source impedance" means the output impedance of the headphone amp (and in fact 120 ohms is a rather ignored standard set by the IHF many, many years ago for headphone outputs). The "nominal impedance" of 200 ohms appears to be the actual impedance of the headphones. So on paper it looks like it should work well.


----------



## nikongod

I 2/3 finished my Crack build earlier this evening.
   
  One of the pieces of wood I received in my original package came with a nasty chip in it, A quick email and all was better. I built the actual "amp" in an all night pleasure fest of solder smoke and soda. The building of the amplifier was fairly uneventful. I penned in DOC's notes for the corrections necessary and got busy with the soldering.
   
  Today I got the base built and the amp all tested and ready to fire up. The process was also fairly uneventful. Its really boring when things just work, so to throw me a curve ball one of my tubes is defective! Mneh, these things happen.
   
  The behavior of the output tube is quite odd based on my previous experience. The tube runs well for a few minutes and then 1 section (the right channel) stops working with a soft pop. It was quite the shock the first time it happened listening to music, but cooling the amp and restarting it got the gears turning.
   
  Despite my best efforts to make tracking the problem down as difficult as possible my suspicions were confirmed when the cathode voltage (pin 3) on the output tube was measured and 0V came up when it was supposed to be (and previously was!) 100V. All I needed to check this thing out was a multimeter!
   
  To determine that the output tube was at fault I employed a wide selection of expensive test equipment to follow a 10Khz signal through the amp. On initial startup the amp performed as expected swinging in excess of 10vp-p into 300 ohms before clipping. After several minutes the right channel cut out and I traced the signal through the amp (I have never actually done this before so I was very excited to have a reason to do so!) and found it passed through the 12au7 properly and got to the grid of the 6080/6as7 OK but then went away. The other channel still went end to end OK. It was at about this time that I thought to do a simple voltage check which came back "really wrong". Its amazing how complicated one can make something they only needed a multimeter to figure out when they have all sorts of fancy test equipment handy.
   
  Satisfied that I solved my problem and seeing how everything was already hooked up I decided to measure away. I got numbers largely in agreement with those posted by bottlehead as to the bandwidth, maximum voltage swing, and the like for the left channel.
   
  My numbers were:
  Note: all numbers are for 12vp-p swing, into 300 ohms.
   
  Bandwidth: (-3db, volume control set to max) 10hz to a bit more than 80Khz
  Voltage swing: 12vp-p before "xy" breaks a line. The sine wave still looks pretty pretty at 15vp-p.
  10K square wave response: Very steep leading edge with no overshoot or ringing at all. Overall very good.


----------



## tdogzthmn

So did you get a new tube? Or are you still unable to use the amp?


----------



## ironbut

Just give Eileen a call. If you can catch her before stuff gets shipped out, she can get it on it's way to you before the weekend.


----------



## Skylab

It's a good idea to pick up a few extra 6080/6AS7G's anyway - they are cheap as dirt, and you often have to go through a few to find one that isn't badly microphonic.


----------



## Doc B.

It could well be that the tube has some sort of heat related issue and we are happy to send a replacement, just give Eileen a call or email. The tubes have all been tested on both sections, but unfortunately my tech doesn't have time to let them each sit for several minutes in the tester (we use a TV-10D/U). So that kind of heat induced short or open could sneak through the screening process. Just for the sake of being thorough I would suggest making sure the other possible causes for 0V on the cathode be covered - rewet the solder joints at both ends of the cathode resistor and the cathode pin of the tube socket, and try giving the tube pins a little polishing with something like a scotch brite pad. Those are also places where a heat related open circuit could occur.


----------



## nikongod

I resoldered all of my joints between pin3 and ground (and pin2 as well) and the tube still stopped working when it warmed up. 
   
  No worries, and I agree it is an unusual problem that a tube checker would not catch. Eillen got a new tube out to me in the mail so things should be great soon.
   
  For the song or so it did play it sounded awesome, and the measurements look very good too. I'l post better impressions when it gets running under full power.


----------



## ironbut

Hey nikongod,
   
  A buddy of mine just got a pair of R10's.
  He's got a Crack kit that he hasn't built and he's figuring on selling it since the R10's are lower impedance than it's recommended for use with this amp.
  I've got a pair of ATH AD2000's that sound great on my Crack (with certain tube sets especially). They're about the same impedance as the Sonys.
  When you get a chance, could you post some impressions of how the your R10s sound with your Crack?
  It would be much appreciated.


----------



## nikongod

Some Pics of my crack.
   
  Im about the worlds least skilled wood worker. Good news, the wood looks nice with some sanding (coarse and fine paper) and 2 coats of tung oil. Tung oil FTW. I need to put 1 more coat of tung oil on and then I will put the little feet on the amp.


   
  The end bell for the transformer was begging for some hammertone love. I cleaned as much of the protective grease and oil off as I could and sanded it a tiny bit just because. Hammertone paint is awesome for stuff like this because it covers and fills little voids in the metal ooh so very nicely.
   

  
  My initial impressions with the HD800 and the T1 (on loan) are that the amp has a slightly "sweet" sound. It draws me in, and it is a touch of color, but it is not syrupy like some other amps. It still has good edges on transients and keeps things from smearing together VERY well. The image placements (in 3d!) and separation are quite good.
   
  Im not sure what else to say about the amp, I have surely spent more money and time on less sonicly rewarding projects in the past.
  Quote: 





ironbut said:


> Hey nikongod,
> 
> A buddy of mine just got a pair of R10's.
> He's got a Crack kit that he hasn't built and he's figuring on selling it since the R10's are lower impedance than it's recommended for use with this amp.
> ...


 

 I think I should note first that I tend to listen fairly quietly(60-65db peak). If your friend listens really LOUD I suppose he may run the amp out of class A which would of course be terrible.
   
  On that note, at my low listening levels the crack holds up well with my R10. The sound is overall very good. Despite the fact that the crack should work better with the HD800 than the R10 a quick head to head still puts the R10 on top. IMO the biggest strength of the R10 VS the HD800 is that it just catches EVERY little detail where the 800 is a hair smoothed over still. The R10 still shines just like that.
   
  I have a bass-heavy low-serial number pair of R10 (crazy! #35x) and the bass performance is good despite the fact that the calculator says that the output caps are too small for a low impedance headphone.
   
  As another thought:
  Although it kind of goes away from the "OTL" idea, it should not be too hard to wire up a set of transformers (or autoformers) in their own little box to put between the amp and the headphones.


----------



## tdogzthmn

Thanks for sharing your impressions, which tubes are you running in your amp?  I see one is a Jan 6AS7G, not sure about the other.  I dont own any tubes so I will have to buy some to roll with.


----------



## ironbut

Thanks nikongod.
  That's a great description of the amps sound.
 I'm kinda shocked how good those humble Panasonic caps sound but I'll probably get around to trying some bypass caps in the weeks leading up to CanJam (I'll be bringing my Crack).
  I might even try some boutique resistors on the 12au7 Rp if I have the right value laying around here.
  I'm holding off on buying the Speedball upgrade until after Chicago. I know from experience that if it's in the house, I won't be able to resist installing it. I want to let folks who're interested in getting a Crack, get a listen to it in essentially stock form.
   
  See you there!


----------



## tdogzthmn

nikongod, is the 6AS7G you are using able to just be popped into the socket or do alterations need to be made to accommodate it?
   
  NM, I did some more research and found they are swappable.


----------



## nikongod

I made this transformer box some time ago as a "prroof of concept" for the SP extreme I had at the time, but it works quite nicely on the Crack too.
   

   

   
  It is a pair of inexpensive Speeco transformers set up as auto-formers with the knob on the front to select between the bunches of various step-down ratios they allow. They sound great with the crack and low impedance headphones.


----------



## Ypoknons

You should commercialize that thing and sell it to the legions of OTL tube amp users out there you know.


----------



## ironbut

I'd love to hear those Speeco's. Could you bring them to CanJam?
   
  Speaking of which, I'll have my AD2000's which isn't a great match for this amp, so you'll be welcome to come by and plug in any headphone you want. Except for signal wire and a TKD pot, it's dead stock.
  I'm dying to try a pair of HD800's and the T1 with it myself. I think the punchy bass and the nice midrange body of this amp could be just what these phones need (for my tastes of course).
  I sent my amp to the Hyatt so it should be there the day I arrive. I have 2 tube sets that seem to be pretty nice that will be there too.
  Tung-sol 6080WB graphite plate/ Tungsram E80cc
  Sylvania 6080WB/CBS-Hytron 5814a
   
  Both sets have their pluses and minuses and which one will spend the most time in the Crack will just come with time. I'm still waiting for a 5998 to arrive so the whole thing could change when that happens.
   
  I'm planning on ordering the Speedball upgrade when I get home from Chicago so we'll see where that puts the sound too.


----------



## HiGHFLYiN9

Well I just bit the bullet, this amp looks like too much fun to pass up, and I have a nice 100K stepped attenuator laying around that would be perfect to swap in.
   
  I saw that the price is going up $20 in the next week, that was the straw that broke my relatively weak camel's back


----------



## ironbut

I just got the UPS tracking notice that confirms that aside from the stock Crack amp I'll have at CanJam, I'll also have a freshly built Crack amp with the Speedball upgrade.
  My thanks to Doc B for finishing one up and next day airing it to the Hyatt.
   
  See you guys there!


----------



## HiGHFLYiN9

Nice! You'll have to post some brief impressions if you have time.


----------



## tdogzthmn

What is a good and reasonably priced stepped attenuator for use in the crack?  Would this be a difficult part to install?  I have limited knowledge of electrical circuitry but I always eager to learn.


----------



## HiGHFLYiN9

Years ago I rolled a Blue Velvet ($25), a Chinese stepped attenuator with soldered in Vishay resistors ($70), and the DACT ($150). The DACT was the clearest and best sounding of the bunch, and the Chinese stepped attenuator wasn't too far off. There was a marked difference between the Blue Velvet and the Chinese SA. Goldpoint runs about $150 as well, but I haven't tried one myself. I don't know if the DACT would be worth purchasing for a $200 amp, I just have one laying around that I'd figured I'd use. If you go searching for a Chinese SA, be sure to pay close attention to the number of steps. 24 is pretty typical, and a minimum imho.
   
  Potentiometers and Stepped attenuators just have six pins that you solder to, it shouldn't pose a problem.


----------



## ironbut

Ya know, I put in a pretty decent TKD pot in my Crack amp. I've used them in a couple of projects and I've found to be a fairly good performer. They are kind of expensive for what you get (around $70) but to get a much better pot you have to spend a lot more. I've also tried some of the "made in china" DACT  copies but I don't really like the sound of those SMD resistors. I think you'll find a pretty small gain in performance for the money spent on fancy pots. To me, it's kind of the icing on the cake.
  After spending some time with the Speedball upgrade, I have no problem sticking my neck out and saying that there isn't going to be anything you can replace in this amp that's going to equal what this does.
  The sound is more detailed, , the noise level is reduced (which may be revealing the improved details), the bass seems to go lower and is tighter, and there's a few dB more gain. Without doing any A/B testing with my stock Crack amp, I found that all vocals sounded more true to life and instrumental separation is better. Best of all, the amp remains very musical and doesn't become clinical which can happen with many well intentioned upgrades.
  It's still just as hard to rip yourself away from the music. That's always the "acid test" for me. When I change something then listen to some music to see how the change effected the sound, and all of the sudden I realize that I've listened to a whole album, I know I'm on the right track.
  Bottom line is, the improvements aren't subtle.


----------



## tdogzthmn

My amp is assembled but I have voltage problems on a few of the terminals and pins.  Both of the tubes have power and have a nice glow.  I want to listen soo badly!
   
  Anyone know if both LEDs should be light?  Right now only the one between A3 and the center pin is lit up.


----------



## Todd R

Quote: 





tdogzthmn said:


> My amp is assembled but I have voltage problems on a few of the terminals and pins.  Both of the tubes have power and have a nice glow.  I want to listen soo badly!
> 
> Anyone know if both LEDs should be light?  Right now only the one between A3 and the center pin is lit up.


 

 Have you posted this at the Bottlehead Forum?  Someone there probably has the answer.


----------



## Canuck57

bump for more build pics or impressions!


----------



## Todd R

Quote: 





canuck57 said:


> bump for more build pics or impressions!


 

 Oh just buy it, it's cheap enough and you know you want one


----------



## nsorens

Oh yeah it's bang for buck!  If can solder and follow directions this has got to be the best tube amp deal out there right now....
  I just installed the Speedball upgrade, it's *VERY* good.  Much more improvement than the cap upgrade that I tried first. 
  Here are some pics.


----------



## gbacic

changing the volume looks dangerous on that amp; your finger would be so close to the tube!


----------



## ironbut

The 12au7 never gets much more than warm. Even so, I don't think I've ever even touched it while changing the volume. I have to the left on my desk so I have to reach across the amp to get to the volume knob too.
  In other words,.. total non issue.


----------



## Canuck57

Quote: 





todd r said:


> Oh just buy it, it's cheap enough and you know you want one


 

 I have! Waiting for it to arrive, ordered the speedball upgrade too! I ordered it assembled, figured I'd probably screw up the assembly...


----------



## Canuck57

@ nsorens   nice crack buddy!


----------



## dannie01

Quote: 





nsorens said:


> Oh yeah it's bang for buck!  If can solder and follow directions this has got to be the best tube amp deal out there right now....
> I just installed the Speedball upgrade, it's *VERY* good.  Much more improvement than the cap upgrade that I tried first.
> Here are some pics.


 

 Wow, the output coupling caps are HUGE.


----------



## nsorens

Thanks Canuck, it sounds great.  You will be very happy with your Speedballed Crack...


----------



## HiGHFLYiN9

I have a pair of Solen 100ufs and a big fat Solen 220uf for the last cap in the power supply whenever my kit arrives, hope they all fit 
  
  Nsorens, how did you color the bell of the transformer black?


----------



## nsorens

That's actually some gun blueing treatment that my brother let me use.  It's a very deep blue (I left it on a little too long) but it came out all right...


----------



## Frihed89

Has anyone used K-701/2s with this amp?  If so, what is your experience?


----------



## druelle

@Nsorens: Did you stain / varnish the wood or is that the natural finish?  Love the color of it!


----------



## nsorens

That's the natural alder wood with two coats of varnish.  It's a nice NW hardwood chassis!


----------



## tdogzthmn

I am still having voltage issues with mine so I am taking it in to a shop to get looked at.  The kit itself was simple to assemble and the instructions were good but I had some issues with the radioshack soldering iron which was not the best tool.  I hope to get the amp running this week!


----------



## Todd R

Quote: 





tdogzthmn said:


> I am still having voltage issues with mine so I am taking it in to a shop to get looked at.  The kit itself was simple to assemble and the instructions were good but I had some issues with the radioshack soldering iron which was not the best tool.  I hope to get the amp running this week!


 
   
  Did you see the 2 revisions posted to the instructions at the Bottlehead forum?


----------



## HiGHFLYiN9

I picked up some "Hammered" type spray paint and some 220 grit sandpaper for the aluminum cover, anyone foresee any problems with painting it?


----------



## tdogzthmn

Yes I have a kit with the revised manual, and I did post my problem on the bottlehead forum but I was still unable to rectify the problem.  Its at a local repair shop now and the guy said he would have it back to me later this week.


----------



## Todd R

Quote: 





highflyin9 said:


> I picked up some "Hammered" type spray paint and some 220 grit sandpaper for the aluminum cover, anyone foresee any problems with painting it?


 

 I always use hammertone paint, it works fine, but sticks better if you shoot a layer of primer & sand it before putting on the color.


----------



## scompton

Quote: 





frihed89 said:


> Has anyone used K-701/2s with this amp?  If so, what is your experience?


 

 I believe this is designed for higher impedance cans and the SEX is designed for low impedance cans.


----------



## apatN

What do I have to do to make this work @ 220v?


----------



## apatN

Doh never mind...


----------



## burgunder

You just have to order the kit with the correct transformer, you will find the option for a 240 VAC transformer at the buttom of the page for the Crack were you can order the kit.
  
  Quote: 





apatn said:


> What do I have to do to make this work @ 220v?


----------



## HiGHFLYiN9

Thanks for the suggestion Todd, I snagged some metal primer. The Queen said mine is finally shipping out, I'm getting a bit anxious


----------



## Todd R

Guys,
  Grab the Speedball upgrade too.
  I listened for 6 hrs straight after I got it installed, a real good sign that something is sounding very right!


----------



## Canuck57

I rec'd my built Crack with the speedball upgrade and I'm really impressed with the sound. My T1s sound GREAT with it, it drives them with no problem at all. I haven't heard a stock Crack so I can't comment on the impact of speedball upgrade. Sounds like it has a huge impact as Todd R indicated above.


----------



## druelle

@Canuck57
   
  If you don't mind could I ask you a few questions regarding the Crack and your setup?  I've noticed in your sig that one of your sources is the Compass. Have you tried feeding the Compass into the Crack?  If so, how were the results?
   
  Also, just wondering if you could give a few comments comparing the Crack to the DV337 (if you still use it, that is) with the HD650s. It looks like our setups are relatively similar (I'm still using the DV336 but was super close to ordering the DV337 before discovering the Crack) and would love to hear your comments.
   
  I ordered the Crack about a week ago with the speedball upgrade, but the Bottlehead crew is still awaiting the wood bases for the Crack and backordered parts for the speedball. The wait is killing me!


----------



## tdogzthmn

My Crack went into the shop for a check-up and I decided to get the speedball installed because it seems inevitable!  I would be curious to see this amp compared to something much more expensive such as the DNA Sonett.


----------



## tdogzthmn

I have my amp back and running!  It sounds fantastic so far and I am very pleased.  I have been letting it run to burn in a bit but I have also been sneaking listens while it plays.  So far I have been mostly using my K400 which sounds incredible!  I can now fully appreciate this under rated headphone.


----------



## Todd R

Quote: 





tdogzthmn said:


> I have my amp back and running!  It sounds fantastic so far and I am very pleased.  I have been letting it run to burn in a bit but I have also been sneaking listens while it plays.  So far I have been mostly using my K400 which sounds incredible!  I can now fully appreciate this under rated headphone.


 
  Great.
  I'm curious, what was wrong with it?


----------



## tdogzthmn

Quote: 





todd r said:


> Great.
> I'm curious, what was wrong with it?


 

 It had some cold solder connections and a bad LED diode.  I also got the speedball installed while it was on the bench.  I have been feeding it lots of CDs and DVD-A and the results are fantastic.


----------



## Todd R

Glad it's working now. I sure love mine too.


----------



## tdogzthmn

What's everyone using with their crack?  Also we should get some pics up of our cracks!!!


----------



## HiGHFLYiN9

I've started the painting / staining process with my crack. Hope to move onto the actual soldering by next week.
   
  I noticed the wood isn't staining too evenly, so other builders should be advised to use a pre-stain treatment. I'm just going to roll with it


----------



## tdogzthmn

Todd, I am giessing you mostly use your HD650 with the crack?  I think you should get some vintage AKGs, they really have a beautiful ring to them.


----------



## Todd R

Quote: 





tdogzthmn said:


> Todd, I am giessing you mostly use your HD650 with the crack?  I think you should get some vintage AKGs, they really have a beautiful ring to them.


 

 Yeah, just what I need, more headphones


----------



## Doc B.

Quote: 





> I noticed the wood isn't staining too evenly, so other builders should be advised to use a pre-stain treatment.


 
  Usually alder takes stain very well, that's one reason we use it. What stain are you using? I get very good results with water base aniline dye, and the worst is probably the Minwax one step combo stain/varnish stuff. You may find that a second application of the stain evens out the color.


----------



## tdogzthmn

Quote: 





doc b. said:


> Usually alder takes stain very well, that's one reason we use it. What stain are you using? I get very good results with water base aniline dye, and the worst is probably the Minwax one step combo stain/varnish stuff. You may find that a second application of the stain evens out the color.


 

 Doc.  I am thinking about buying another base "just the wood" for my amp because I love to experiment with colors and finishes.  What is the price for just the wood?  By the way the amp has been running beautifully since I got it back and I have been most pleased.  I have been stuck using my NAD  player because my DAC is not good enough for the crack!  Let us know when the Bottlehead DAC is close!!!


----------



## HiGHFLYiN9

Quote: 





doc b. said:


> Usually alder takes stain very well, that's one reason we use it. What stain are you using? I get very good results with water base aniline dye, and the worst is probably the Minwax one step combo stain/varnish stuff. You may find that a second application of the stain evens out the color.


 

 Doh, that's exactly what I'm using (Minwax one step seal and stain - Red Oak). I've put two applications on so far, and it looks like a third might help, but I don't think I'll be getting an even stain out of it no matter how many applications I put on. Live and learn, as they say.


----------



## HiGHFLYiN9

Quote:  





> Let us know when the Bottlehead DAC is close!!!


 

 Now that's something I'd be very interested in, there's a lack of tube DAC kits on the marketplace, or even affordable tube DACs in general (aside from a few Chinese designs), I think there would be quite a calling for it.


----------



## tdogzthmn

Quote: 





highflyin9 said:


> Doh, that's exactly what I'm using (Minwax one step seal and stain - Red Oak). I've put two applications on so far, and it looks like a third might help, but I don't think I'll be getting an even stain out of it no matter how many applications I put on. Live and learn, as they say.


 

 Regarding the stain did you sand the wood first?  Sometimes if you sand too hard or with too high a grit the wood can get burnished which prevents the pores in the wood from taking in stain.


----------



## HiGHFLYiN9

I sanded with 180 and then 220, both pretty briefly with an electric sander.


----------



## Doc B.

I've never had good results with the one step stuff on any kind of wood. It's kind of surprising that it dominates the shelves at the home improvement stores. If you want to take another shot at it some day we do sell wood base kits by themselves. Around here we pretty much stick with premixed water based aniline dyes and Varathane Premium oil base polyurethane finish for dark colors and Varathane Diamond water base finish for the blond finish like you see on most of the web site photos. For a really amazing and astoundingly labor intensive old school finish I recommend aniline dye, a white shellac fill coat (Bullseye) and then several coats of hand rubbed Ace Hardware spray lacquer
   
  Re the DAC, it's a pretty involved project and it will still be a while before it's ready. But it should be fairly versatile, capable of up to 192/24, and we're working to make it able to automatically adjust to different sample rates.
   
  Looks like I may have some AKG1000s on the way, so I guess it's time to start planning a Paramount 300B headphone amp setup next...


----------



## Canuck57

I bought a used S.E.X. amplifier and didn't like the finish on the wood base so I sanded it down to bare wood and applied 3 coats of Danish Oil. It's VERY easy to work with, I've used it tons of times and highly recommend it. You just brush it on (or use an rag to apply it), wait about 20 minutes for it to sink in, then rub off the excess. Applying additional coats deepens the colour.
   
  My Crack (pre-built my Bottlehead) came with the light blonde natural finish which is quite nice as well. Excellent amp.! T1s and 650s sound excellent with it!


----------



## ironbut

Quote: 





doc b. said:


> Looks like I may have some AKG1000s on the way, so I guess it's time to start planning a Paramount 300B headphone amp setup next...


 

 Sounds like you're hooked!
  A Paramount K1000 amp is a natural. A nice sounding 300b amp with plenty of drive is just what those cans need IMHO.
  If you can get one up and running by Oct., you should plan a trip to Denver to show off _all_ your headphone offerings. John's running the Headfi end of that show again and I'm sure you'd be a very welcome addition to the headphone vendor list there.
   
  http://www.head-fi.org/forum/thread/499107/canjam-at-rmaf-2010


----------



## Doc B.

Folks who were at the Bay Area Head-fi event last year may have heard a Paramount/K1000 setup that we were demoing. I'll check in with John.


----------



## HiGHFLYiN9

Quote: 





doc b. said:


> I've never had good results with the one step stuff on any kind of wood. It's kind of surprising that it dominates the shelves at the home improvement stores. If you want to take another shot at it some day we do sell wood base kits by themselves.


 

 I may take you up on that offer at some point Doc, I'll have to see how satisfied I am once the final coat is applied.


----------



## maverickronin

I'm considering one of these for my HD650s.  Could anyone with the relevant experience answer a few questions for me?  How does it compare to prebuilt tube amps in the same price range (LD MKIII, Darkvoice 336, etc)?  Is it a 'tube-y' tube amp, and in what way?  Liquid midrange? Syrupy? Rolled off bass and treble?  I looking for liquid mids, a drizzling of syrup, and all the bass I can get.
   
  Thank you in advance.


----------



## tdogzthmn

Mine just sounds stupid good.


----------



## komebudu

Is there beneficial of using impedance adapter for low impedance hp...? ie... 150ohms onwards...
   
http://cgi.ebay.com.my/IMPEDANCE-RESISTANCE-ADAPTOR-3-5MM-6-35MM-PLUG-/300338066075?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item45ed8b329b


----------



## Todd R

Quote: 





komebudu said:


> Is there beneficial of using impedance adapter for low impedance hp...? ie... 150ohms onwards...
> 
> http://cgi.ebay.com.my/IMPEDANCE-RESISTANCE-ADAPTOR-3-5MM-6-35MM-PLUG-/300338066075?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item45ed8b329b


 
  Since that is something aimed at the ER-4, it's simply an in line resistor. I think a true impedance matching would take some type of transformer or a circuit change as discussed here. Even though I started the thread, I haven't made any changes to my Crack yet to see how well it might work.


----------



## komebudu

Thx Todd,
   
  Perhaps Bottlehead will consider in the future...selling crack with different coupling caps value ...


----------



## tdogzthmn

There are some posts about changing the cracks resistance in the bottlehead fourm.  I suggest reading through those threads for answers.


----------



## druelle

Just received notice that my Crack shipped today. Now begins the painful process known as waiting...


----------



## HiGHFLYiN9

Quote: 





druelle said:


> Just received notice that my Crack shipped today. Now begins the painful process known as waiting...


 
  Nice! Welcome to the club


----------



## druelle

While I'm waiting for it to arrive, any tips for a first time builder?


----------



## Todd R

Quote: 





druelle said:


> While I'm waiting for it to arrive, any tips for a first time builder?


 

 Read the directions carefully and check off each step as you do it. Don't burn your fingers, and don't eat the solder


----------



## Doc B.

Here's a few suggestions:
   
  Plan on taking your time. Most kits that are assembled in a hurry end up with something mis-wired or with a bad solder joint somewhere, that might keep the amp from working the first time, or might create a failure a week or a month down the road. One can build this kit in an evening with some dedication and a good espresso, but a more reasonable (and enjoyable) time frame is to consider the build something to be done over a couple of evenings or on a weekend. A lot of folks end up with a sort of "post-build'em depression" once the kit is done, and typically the second thing they build is done at a more leisurely pace in order the savor the actual process of creation.
   
  Good tools always make the job more pleasant. A good solder station costs more than a cheapo Radio Shack soldering iron, but it will work better. Based on my experiences soldering equipment together over the past 16 years I would say something on the order of 1000 times better. A good Weller or Hakko can cost under $100 and is worth its weight in gold when you get to those particularly tricky soldering bits. The most popular solution, for good reason, is to buy a Hakko 936. You will probably not need another iron for the rest of your life. Used solder stations are usually a reasonable purchase if you can make sure they work and the tip is in good shape. If you get a Radio Shack iron the tip will be ready for the garbage can when you are done with your first kit - if it makes it all the way to the end.
   
  A magnifier will save you lots of headaches. Use it to examine every solder joint. Don't let some sort of goofy notion that only old farts need a magnifier keep you from using one. I've shown more than one under 40 yo guy a solder joint that wasn't right through my flip down magnifiers (chicks really dig me when I wear them) that he didn't catch with his naked eye. Same goes for a good work light. Makes the experience much more pleasant.
   
  Good wire cutters like Weller (Cooper Tool) side cutters are a joy to use, and I like the "automatic" style wire strippers that have little jaws that come together and jaws that pull the wire out from the insulation as you squeeze the handles. Once again, it is hard to be certain that the Radio Shack equivalents will even make it all the way through the build without breaking.


----------



## ironbut

Quote: 





doc b. said:


> A magnifier will save you lots of headaches. Use it to examine every solder joint. Don't let some sort of goofy notion that only old farts need a magnifier keep you from using one. I've shown more than one under 40 yo guy a solder joint that wasn't right through my flip down magnifiers (chicks really dig me when I wear them) that he didn't catch with his naked eye. Same goes for a good work light. Makes the experience much more pleasant.


 
   
  Best advice ever! I got a pair of flip downs a couple of years ago on Doc's advice and man,.. what a difference these guys make (at least to my 50+ year old eyes)!
  Not just for soldering but have you ever tried to remove a metal splinter? You know, the ones that get lodged in a pore of your finger then you grab something and it gets pushed in?
  Well, finding the end of these and getting a pair of tweezers on it is a breeze with my flip downs.
  Also great for reading that tiny printing on tiny stuff and doing neurosurgery on your sisters cat (just kidding).
   
  I bought these and I'm happy with them but there are certainly cheaper ones and maybe Doc and others can chime in on what they've got.
   
  http://www.amazon.com/Magna-Visor-Bausch-Lomb-Lenses/dp/B003E6OJ9U/ref=sr_1_76?ie=UTF8&s=hpc&qid=1279313719&sr=1-76


----------



## tdogzthmn

^ I agree with what doc says.  Also make sure you have a decent soldering iron and extra tips, I had a few bad connections due to cold joints.  A good iron will thoroughly heat the solder and the joint.


----------



## Armaegis

Hmm, I got a pair of Sextetts coming in but didn't realize they were 600 ohm, so this kit looks like just the thing I'd need (argh, this hobby feeds itself!)
   
  Has anyone tried this with Orthos? I've been thinking of getting the Fostex T50RP from my local music shop, which are only 50 ohm.


----------



## tdogzthmn

Quote: 





armaegis said:


> Hmm, I got a pair of Sextetts coming in but didn't realize they were 600 ohm, so this kit looks like just the thing I'd need (argh, this hobby feeds itself!)
> 
> Has anyone tried this with Orthos? I've been thinking of getting the Fostex T50RP from my local music shop, which are only 50 ohm.


 

 No orthos but I have the K240 M which is also 600 ohms.  Sounds very detailed and neutral.


----------



## gopack87

I'm thinking about getting some NOS 1958 RCA 6AS7G tubes off ebay to try some tuberolling.  6080 and 6AS7G are interchangeable, right?  My Crack with speedball upgrade was assembled by the Bottlehead team and I don't know if any mods or anything need to be done to try different variants


----------



## Doc B.

6080 and 6AS7 are interchangeable, and you can also plug in a 5998 without making any other change even though it has somewhat different specs.


----------



## gopack87

Quote: 





doc b. said:


> 6080 and 6AS7 are interchangeable, and you can also plug in a 5998 without making any other change even though it has somewhat different specs.


 

 Awesome, thanks!  Let the tube rolling began


----------



## druelle

I'm currently building my Crack and have done a bit of research on 12AU7 tubes, but haven't come across any recommendations for 12AU7 replacements for the Crack.  Does anybody have any experience rolling 12AU7s in the Crack?


----------



## maverickronin

I've already got a small collection of 12AU7s for my Indeed G2 Hybrid, that I'll be able to try out eventually.  I just ordered my crack last week, so It will be a bit before I receive it and get a chance to build it.


----------



## Doc B.

So far I have found that the same 12AU7s I like in other gear work for me in the Crack. Mullards, Teles, Amperex, the usual suspects.


----------



## ironbut

Yeah, that Mullard that Doc supplied with the "Demo" Crack/Speedball for CanJam was real nice! IIRC, it was mated with an RCA 6080 (or GE?)
  I certainly don't have the level of experience that Doc has with 12au7 types but I tried a few of the common subs. As usual, what tube you're using in the 6080 position and any component mods makes a difference in the 'tuning'.
  Subs I've tried;
  Tungsram E80cc
  CBS/Hytron 5814a
  Brimar 13D5
  RCA 5963 bp d getter
   
  and a few other 12au7's that just happened to laying around that really weren't memorable.
   
  6080 types
   
  Sylvania 6080
  RCA 6080 (supplied w/kit)
  Tung-sol 6080 graphite plate
  Tung-sol/Heintz and Kaufman 5998
   
  My fav's depended on whether the Crack had the Speedball upgrade or not.
   
  Stock, I like the Tungsram E80cc with the Sylvania or the graphite plate Tung-sol. Pretty subtle differences so your cans and ears will make all the difference.
  BTW, I didn't have a 5998 before I upgraded so that could be total hogwash if you have this tube.
   
  After the upgrade, I really like the CBS/Hytron 5814a with the Tung-sol 5998. I think the CBS is in the same ballpark as the Mullard I mentioned above so I'd say that Doc's recommendations with the 5998 are all bound to be over the center field wall as well.
   
  Some particulars;
   
  The Tungsram E80cc is slightly higher gain and very clear/transparent. For many of the 6080's,it was too much of a good thing IMHO. Very impressive sounding and great for demo type listening but not something that I'd enjoy day in and day out. IOW audiophile sounding.
   
  I really found the Sylvania 6080 to be something of a sleeper. It went well with a large majority of 12au7 types including the E80cc. Great bass, fluid mids and highs and just didn't do anything wrong.
   
  The TS graphite plate had a quicker sound and with something like the CBS/Mullard it was a great match. With others, it seemed a little bass shy.
   
  The Tung-sol 5998 with the CBS, Mullard is heaven IMHO. Bear in mind that I have made a couple of mods to my Speedballed Crack such as film output caps, slightly upgraded pot and silver signal wire but those pale in comparison with the improvements that the Speedball and the 5998 made. They were done before the Speedball since it would be tougher to get in there after the extra boards were installed.
   
  As usual, YMMV. These listening impressions were done with my AD2000.


----------



## HiGHFLYiN9

Coming along slowly but surely, just waiting on a part at the moment


----------



## tdogzthmn

^ impressive looking build.


----------



## ironbut

Looks good Highflyin9!
  Damn, your picture reminds me of some subs I meant to try before installing the Speedball. Oh well.
  Those Kiwame's sound pretty nice but I don't like the smell when they get warm.


----------



## HiGHFLYiN9

Thanks! I found out later on that the larger wirewounds end up getting tossed to the curb when the speedball is installed... doh.
   
  If I'm able to swing the space, the third 220uf is going to get pulled in favor of a solen film cap. The 100uf caps are going to be Solens, perhaps bypassed with some Russian PIOs.
   
  Tube sockets are the teflon type with Woo boards. I punched the chassis and dropped in a Neutrik locking as you can see. Stepper is a DACT I had in the parts bin, I probably would have went with a TKD or Noble otherwise.
   
  I'm beginning to use the Kiwames for everything now, not only do they sound really nice, but I really like the unusual flat green look. I haven't noticed the smell yet, lol, an added bonus I suppose. Here's a bonus photo of a kiwame stepper I just put together tonight:


----------



## tdogzthmn

I forgot how good the K240 M sounded with this amp,  I have been too busy with the K340 and K400.  I would really like to hear a K240 sextett, whos got one?


----------



## Armaegis

I've got a sextett. Just need to get off my duff and actually build this thing...


----------



## HiGHFLYiN9

I finally got the 9 pin PCB I was waiting on, so I finished the initial build last night (minus wiring in the speedball, that will have to wait until after testing and initial listening). Also I've gotta touch up the paint on the top-plate a little bit before it's photo-worthy.
   
  I'd love to see some photos of some other peoples builds, even if they're still in progress like mine


----------



## HiGHFLYiN9

A couple more photos:
   
  I have a friend in the promotional products business. I created a vector file with a nice vintage font and sent it over to him to have made into a metal badge for the amp. I picked "Bottlehead" rather than "Crack" as it sounds a little classier  It's a weathered copper finish, about 3" wide. He passed a sample along to Doc, just in case he wants to have a few made for customers.
   





   
   
   
  Here's a progress pic with the big'ol Solens. It should be ready for testing, then I can drop the Speedball and the bypass caps in.
   

   
   
*EDIT: I've had countless people ask about how to get a badge made like the one above. Unfortunately my contact is no longer in the promotional products business so I do not have any referral information. *


----------



## TheWuss

that's one sweet lookin' badge.
  very well done, highflying.


----------



## mrarroyo

Bryan, that "Crack Amp" is coming along sweeeet! I wish I could listen to it or have the building abilities you have. Enjoy it.


----------



## tdogzthmn

Did you use a custom wood with your amp? It looks too good to be stain.


----------



## Armaegis

Hmm, solder looks ok, resistance checks look good, powers up, tubes glow... but I'm getting negative voltages... Help?
   
   


Spoiler



1      -1
 2      0
 3      0  
 4      -1
 5      0

 6    0
 7    0
 8    0
 9    0
 10    0

 11    0
 12    0
 13    -1
 14    -232
 15    -1
 16    0

 17    0
 18    -90
 19    -86
 20    -232
 21    -1
 22    0
     
 a1    0
 a2    0
 a3    1
 a4    -232
 a5    -232
 a6    -1
 a7    0    
 a8    0
 a9    -232

 b1    -1
 b2    -1
 b3    0
 b4    -1
 b5    -1
 b6    0
 b7    -232
 b8    -233


----------



## HiGHFLYiN9

Thanks gents. Miguel, I'm still a little green at the whole amp making thing, trying to learn what I can here and there. Doc includes some pretty detailed instructions if you want to give a "crack" at it 
   
  TDogz, that's the stain from the hardware store; MinWax stain and seal and four coats of Minwax satin polyurethane. It's on the base that came with the kit. I'm not super satisfied with the way the stain laid on the wood, but it's a nice color. You're seeing the best side in the photo 
   
  Armaegis, are you sure you don't have the leads on the multimeter reversed?


----------



## Armaegis

Quote: 





highflyin9 said:


> Armaegis, are you sure you don't have the leads on the multimeter reversed?


 

 Positive (pun intended). Triple checked all my solder points and component orientations. I wonder if I just have a bad component somewhere.


----------



## ironbut

You've got either got your diodes reversed or the wiring and resistor out of the bridge is reversed,.. almost certainly the diodes.
  If you think of the band on the diodes just like the line on a schematic with the arrow pointing into the line from the opposite end. That means the current is traveling in from the end of the diode without a band. Two of the four junctions are the + and - terminals. The + junction is the one where the two diodes are pointed together and the negative junction is the one where the two diodes are pointed away from each other. The positive junction is where the resistor leading to the power supply caps is and the negative is connected to the wire that leads to the negative end of the caps.
  If you do have these reversed, don't bother taking the diodes out, just switch the resistor and wire connections.
  There's a good picture of what's going on in this wiki page;
   
  http://en.wikipedia.org/wiki/Diode_bridge
   
  That capacitor off to the right is the same as the filter caps in the Crack.


----------



## Armaegis

Grr, nope. Diode and cap orientation was the first thing I checked. Too tired to check it over for a fifth time right now. Will need to take a crack (oi, another pun) at it tomorrow or the day next with some fresh eyes.


----------



## Todd R

Armaegis,
  Don't forget to post this problem at the Bottlehead site too. Someone there can help also.


----------



## andrew3199

Beautiful looking amp. Has anyone tried the Bottlehead with Ety's?


----------



## WyldRage

Etymotic IEMs? Real bad idea: they have far too low impedance for this amp. The Crack has an output impedance of 120 ohm in stock form, so you should try to match it using 120 ohm or higher input impedance. That means Beyers Premium line 250 or 600 ohm, old AKGs and the K601, or top-of-the-line Sennheisers. I may be missing a few, but I believe that's pretty much it for high impedance, in-production headphones.


----------



## Armaegis

I made myself some resistance adapters so I could use my low impedance cans. Now if only I could get the crack to work...


----------



## ironbut

This thread (and well as the Crack forum on the Bottlehead forum) has gotten big enough that some of the stuff that was discovered by the "early adopters club" is pretty well buried now. Some of that "stuff" were typos in the manual that was shipped with the first run of kits. Doc did a great job of posting the corrections on the Bottlehead site and rewriting those items in the manuals that went out with the subsequent runs.
  If you bought your kit from an original owner who never assembled it, you would be advised to check the early threads on the Bottlehead site for any threads with titles like "Crack Manual -corrections".
  Here's the one that Doc posted with the first manuals;
   
  http://www.bottlehead.com/smf/index.php/topic,657.0.html


----------



## Armaegis

Much to my dismay, my crack doesn't have enough juice to suitably push my vintage Fostex T40 (orthos). I wonder if the speedball will fix this? I'm comparing to my G&W T2.6f tube amp which does seem to adequately power them.


----------



## Todd R

Quote: 





armaegis said:


> Much to my dismay, my crack doesn't have enough juice to suitably push my vintage Fostex T40 (orthos). I wonder if the speedball will fix this? I'm comparing to my G&W T2.6f tube amp which does seem to adequately power them.


 

 The Speedball update isn't going to make the amp any more powerful, it replaces some resistors with a constant current source.
  What impedance are those headphones?


----------



## Nebby

If my google-fi is correct, it's got an impedance of 50ohms which is certainly less than the recommended 100ohm min impedance for the Crack amp.
   
   
  Quote: 





> Crack is an output transformerless amp designed specifically for running higher impedance (100 ohms or higher) headphones like the many Sennheiser, AKG and Beyer designs.


 

  Quote: 





todd r said:


> The Speedball update isn't going to make the amp any more powerful, it replaces some resistors with a constant current source.
> What impedance are those headphones?


----------



## Beefy

Quote: 





armaegis said:


> Much to my dismay, my crack doesn't have enough juice to suitably push my vintage Fostex T40 (orthos). I wonder if the speedball will fix this? I'm comparing to my G&W T2.6f tube amp which does seem to adequately power them.


 
   
  Quote: 





todd r said:


> The Speedball update isn't going to make the amp any more powerful, it replaces some resistors with a constant current source.
> What impedance are those headphones?


 


 The Fostex is just 50 ohms, I think, and quite insensitive thus requiring a lot of current. Not a good match for the Crack at all.
   
  The G&W T2.6f looks like it is a hybrid with output MOSFETs supplying a decent current drive and low output impedance, which is why it works a lot better.


----------



## Doc B.

We try to point out everywhere we can that Crack is intended for headphones of 100 ohms or higher impedance. A lower impedance, low sensitivity headphone is going to work a lot better with our S.E.X. kit, which can drive loads down to 4 ohms with 2000 mW of output. A third alternative for extreme cases of low sensitivity is our Paramount amps, which can deliver 8 watts into 16 ohms, and which we use with the notoriously difficult to drive AKG K1000s. Amongst these three choices we should pretty much have every headphone covered, save for electrostats.


----------



## Armaegis

I've read about impedance matching, which is why I was using my low resistance cans with an impedance adapter (I made a couple in 90 and 280 ohm flavours). Overall I found it just gave me better control over the volume and tightened up the bass. The adapters didn't help much with the T40s though. Could it be because orthos are very current hungry cans? (at least from my understanding they are)
   
  Impedance matching is generally about optimizing power transfer correct?
   
  On the flip side, I liked my Sextetts (600 ohm) better out of the Crack than the G&W.


----------



## Beefy

Quote: 





> Originally Posted by *Armaegis* /img/forum/go_quote.gif
> 
> Impedance matching is generally about optimizing power transfer correct?


 


 From my terribly uneducated viewpoint, the benefits of impedance matching for maximal power transfer _seem_ to be grossly over-rated. In the case of your orthos damping factor is FAR more important, so you want as low an output impedance as possible and no series or parallel resistances between the amp and the driver, because they reduce the amp's control over the driver.
   
  And yes, your orthos need a lot of current.


----------



## Skylab

One thing I have definitely learned is you cannot just add in-line resistors and think that is "impedance matching".  Impedance matching can only be accomplished with transformers.


----------



## Armaegis

Well what's the point of that Etymotic 4S-4P adapter then?


----------



## Beefy

In that case, it is to deliberately increase the amp's output impedance. The exception that proves the rule.


----------



## Doc B.

Yes, damping factor seems to be an issue as the more common complaint from folks who use Crack with low impedance cans is soft bass, which is typically very well controlled and punchy with high impedance headphones. The low impedance output of amps like the S.E.X. amp means that DF can be lower and they will be able to keep the bass tight on the bottom end with low and high impedance cans, and the S.E.X. can also put out enough power to offer decent voltage swing into higher impedance headphones. So it seems to be a more universal solution. That said, most folks (including me) prefer the Crack with high impedance cans, S.E.X. with lower impedance cans.
   
  If one can justify buying several different headphones, it might be most rewarding to optimize the amp setup for each one.


----------



## Beefy

Quote: 





doc b. said:


> The low impedance output of amps like the S.E.X. amp means that DF can be lower and they will be able to keep the bass tight on the bottom end with low and high impedance cans, and the S.E.X. can also put out enough power to offer decent voltage swing into higher impedance headphones. So it seems to be a more universal solution. That said, most folks (including me) prefer the Crack with high impedance cans, S.E.X. with lower impedance cans.


 


 I'm curious about this...... I've been looking at your kits, trying to decide on my next project. I'm interested in S.E.X. for my low impedance phones, but am a little confused by the fact that it uses 120ohm resistors in series with the output.
   
  Also, I have seen some complaints of the gain of S.E.X. being too high, even with high impedance phones. Can you possibly tell us the overall voltage gain of the Crack and S.E.X. into 32 and 300 ohm loads?


----------



## Armaegis

In my case with the orthos, it wasn't that the bass was soft. The bass actually extended quite well. The issue was that the sound was congested, especially during "busy" or complex passages in the music. At those points, the music became flabby and almost sounded like clipping, especially in the lower end.
   
  I'm not looking for a solution per se; more interested in an explanation. I'm assuming it's a power delivery thing, but if there are other factors I'm all ears.


----------



## Beefy

Quote: 





armaegis said:


> In my case with the orthos, it wasn't that the bass was soft. The bass actually extended quite well. The issue was that the sound was congested, especially during "busy" or complex passages in the music. At those points, the music became flabby and almost sounded like clipping, especially in the lower end.
> 
> I'm not looking for a solution per se; more interested in an explanation. I'm assuming it's a power delivery thing, but if there are other factors I'm all ears.


 


 If the bass is soft, it is an effect of the output coupling capacitors being too small. The coupling capacitors form a high pass filter with the 'resistance' of the phones, literally cutting off the bass. You can help improve that by increasing the capacitor size.
   
  But in your case, congested flabby bass is almost certainly from poor damping factor. Very little that you can do about that. Apparently, there are alternatives to the 6080 that decrease output impedance from 120 ohms to 70 ohms which may help somewhat, but the Bottlehead forum is a better place to find this info than my memory.


----------



## Armaegis

Hmm... at this point I'm thinking I have a misunderstanding of the term damping factor... what does it mean in technical terms?


----------



## Nebby

Wiki has a good overview of Damping Factor: http://en.wikipedia.org/wiki/Damping_factor


----------



## Beefy

Quote: 





armaegis said:


> Hmm... at this point I'm thinking I have a misunderstanding of the term damping factor... what does it mean in technical terms?


 


 I don't fully understand the nuances myself, but I personally think of it this way...... if the damping factor is high, the amp has a very strong hold over the headphone driver. Helps stop resonance, overshoot, etc. If the damping factor is low, the amp has less control over the driver. It overshoots and otherwise flops about.
   
  In headphones with heavy and stiff drivers, low damping factor is not that big of an issue because the mechanical effects hold it in check. Orthos, however, have a _very_ light driver that can flop around a lot if the amp doesn't have tight control.
   
  And yes, Wikipedia article is quite helpful. Basically, damping factor is driver impedance divided by amp output impedance. Your 50R ortho from a 120R OTL tube amp has a damping factor of 0.42. The same headphones from a stout solid state amp like the B22 with an output impedance below 1R would have a damping factor of greater than 50.


----------



## Doc B.

Quote: 





beefy said:


> I'm curious about this...... I've been looking at your kits, trying to decide on my next project. I'm interested in S.E.X. for my low impedance phones, but am a little confused by the fact that it uses 120ohm resistors in series with the output.
> 
> Also, I have seen some complaints of the gain of S.E.X. being too high, even with high impedance phones. Can you possibly tell us the overall voltage gain of the Crack and S.E.X. into 32 and 300 ohm loads?


 

 The gain of both amps is 15 dB. The Crack is measured into 300 ohms and the S.E.X. into a load that matches the output tap, i.e., 8 ohm load on the 8 ohm tap. There is no problem at all with removing the 120 ohm series resistors from the S.E.X. and wiring the output directly to the headphone jack if that is your favorite flavor. The resistors are there to meet the standard for headphone jack output impedance established by the IHF many years ago, and they serve simply to keep the output level fairly even when you swap from low impedance headphones to high impedance ones.
   
  I do wonder if those who complained that the gain is too high noticed that there is a volume control on both amps. As we have no control over the source output level we have to allow for lower source levels in some systems. In other words if some guys say they have too much gain, others will say they don't have enough. The only standard in audio that is adhered to with any conviction is that manufacturers pretty much ignore standards.
   
  Also re soft bass: I believe that there may have been a semantics crosswire, largely my fault. By soft bass I meant uncontrolled, not rolled off. Small caps do indeed cause bass rolloff. Way small caps can even cause a bass hump above the rolloff in some systems. And yes, low damping factor causes flabby, slow bass. In some cases speakers can be designed specifically for amps with lower damping factors. Most are not designed this way.


----------



## Beefy

Quote: 





> Originally Posted by *Doc B.* /img/forum/go_quote.gif
> 
> I do wonder if those who complained that the gain is too high noticed that there is a volume control on both amps.


 

 HA! 
	

	
	
		
		

		
			




   
  Thanks for the reply Doc, it is very helpful to myself and other prospective builders.


----------



## milosz

OK  I finished building the Crack with Speedball.  Even though I goofed and at first it didn't work the folks at the Bottlehead Crack forum pointed me in the right direction and I found what I did wrong. (I didn't read the model numbers on the sides of the TO-18 small signal transistors, I just said to myself  "these 4 transistors are all the same"  well guess what there are two 2N2097  and two 2N2222's!  And they are not interchangeable. DOH! Oh well I put them right and now it works.)
   
  I also replaced the 100 uF electrolytic output caps with 100 uF / 250 v  Dayton polypropylene metalized film caps, which do sound a bit nicer in the highs.
   
  This is a GREAT sounding amp for the Sennheiser HD800's, IMHO.


----------



## HiGHFLYiN9

I'm digging the gloss white finish. Did you take any pics of your handiwork on the inside?


----------



## ironbut

Yeah, I like the white on white and the different knob!
  The "through the blinds at sunset" photo is pretty cool too.
  Have fun.


----------



## milosz

The inside is not anything special. Maybe I'll post a picture of it later.
   
  Paint is Rust-oleum gloss white with a coat of Rust-oleum clear gloss laquer over. (Home Depot)
   
  Wood is Minwax "chestnut" stain (3 coats) with 5 coats of Minwax rub-on poly.
   
  The knobs are Kilo from Digi-Key, solid machined aluminum, under $4. http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=226-4131-ND


----------



## HiGHFLYiN9

Finally finished with mine (mostly, I want to add a vintage pilot light at some point).
   

  A pic of the inside. A few variations to the kit, including:
   
  Cardas Rhodium RCAs
  DACT 100k stepped attenuator
  Kimber TCSS wiring
  Kiwame Resistors
  Neutrik Locking Plug
  Obbligato 1uF Copper coupling caps (hidden under Speedball board)
  Solen 100uF Capacitors
  Teflon Tube Sockets
  Woo Audio Tube Socket PCBs
   
   
   
   

  Attached to the bottom are EAR feet for ample ventilation
   
   

  Here's a photo of the bypass caps nestled under the vent holes. Do note that if you use these caps, the shell is conductive.
   
   
   

  Here's the whole shebang
   
   
   

  Made especially for the kit is a 10 gauge power cable with Marinco plug, Right angle IEC and DHLabs power cable.
   
   
*EDIT: I've had countless people ask about how to get a badge made like the one above. Unfortunately my contact is no longer in the promotional products business so I do not have any referral information. *


----------



## Skylab

WOW! Nicely done - very, very nice looking.


----------



## TheWuss

i think i just messed myself.
  that amp looks amazing.
  highflying, it took you a while, but you should be very proud of the results.
  best looking crack i've seen.  
	

	
	
		
		

		
		
	


	



  heck - one of the best looking amps i've seen...


----------



## HiGHFLYiN9

Haha, thanks fellas. It did take forever, most the of the time waiting was for random parts to arrive, but the actual build was pretty quick. I really like the hammertone paint, but I've decided that future builds will be powder-coated for increased durability. I actually had to second coat the plate after the amp was completely built to cover a couple of small scratches, carefully masking everything off with painters tape.


----------



## Armaegis

If I ever build another one, I'm either going to layer the plate with painter's tape to protect it or cut out a sheet of cardboard and tape that on top. I spent way too much time polishing mine by hand (I don't have a hand sander), only to scratch it up carelessly. There's one particularly bad gouge where I slipped up with a dremel because one of the holes was slightly out of line so I tried widening it (I know, I know, I should have been going from the back side, gimme a break this was my first time doing this sort of thing 
	

	
	
		
		

		
		
	


	




).
   
  Sigh, I also botched the finish. Note to self: spray on poly is terrible stuff.


----------



## Doc B.

Quote: 





> I actually had to second coat the plate after the amp was completely built to cover a couple of small scratches, carefully masking everything off with painters tape.


 
  Yup, hammertone finishes really need some time to harden up. To be safe it's best to let the plate sit for at least a week, maybe more. Hardly anyone has that much patience, including me!


----------



## Canuck57

Beautiful job Highflyin9! Love the new Bottlehead nameplate, couldn't find it on their website though?


----------



## Calypso

Quote: 





canuck57 said:


> Beautiful job Highflyin9! Love the new Bottlehead nameplate, couldn't find it on their website though?


 

 Try checking out page 16. That might give you a hint 
	

	
	
		
		

		
		
	


	




.


----------



## Doc B.

That badge is very nice. We have been having a badge made for our products for several years now, that uses the logo I designed for Bottlehead. We make it optional because they are a bit spendy, and we sell them at our cost.


----------



## milosz

I love that Bottlehead badge, the logo is a riot.  It looks like it came from a DeVry ad near the back of a 1956 issue of RADIO-ELECTRONICS.....


----------



## ztsen

I have ordered Crack+speedball. But need to wait for the 240V to be available. So need to wait patiently now.
   
  Now i have below tools, any other tools I need to complete Crack?
  -soldering gun
  -desoldering pump
  -helping hand+magnifier glass (1 hand tightening button already broken....china made)


----------



## Beefy

Quote: 





> Originally Posted by *ztsen* /img/forum/go_quote.gif
> 
> -desoldering pump


 


 Check, double check, and triple check to make sure you get it right the first time. Then you won't need to desolder anything.
   
  I would also suggest you buy some good quality wire strippers.


----------



## Todd R

Quote: 





ztsen said:


> I have ordered Crack+speedball. But need to wait for the 240V to be available. So need to wait patiently now.
> 
> Now i have below tools, any other tools I need to complete Crack?
> -soldering gun
> ...


 
  Wire stripper, screwdrivers, needle nose pliers are very helpful.


----------



## kboe

WOW!  
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
  Thats it, just WOW!


----------



## WyldRage

You'll need some solder as well. I recommend getting some good one: it will be much easier to use. An eutectic one is always good. Lead-based solders are suposed to be easier to work with, since it flows easier, though some believe that lead can degrade the signal since it is a poor conductor.  I didn't take any chance and I used Lead-free Wonder Solder Ultraclear, bought off e-bay, and it was much easier to use than some cheap lead-free solder (which is now gathering dust on my shelves). I have also heard good things about the Cardas Tri and Quad Eutectic solders, the latter being leaded.


----------



## HiGHFLYiN9

Quote: 





todd r said:


> Wire stripper, screwdrivers, needle nose pliers are very helpful.


 

 Indeed. A cheap set of small pliers will go a long way.


----------



## ztsen

I still have some WBT solder..think i will use that
  
  Quote: 





wyldrage said:


> You'll need some solder as well. I recommend getting some good one: it will be much easier to use. An eutectic one is always good. Lead-based solders are suposed to be easier to work with, since it flows easier, though some believe that lead can degrade the signal since it is a poor conductor.  I didn't take any chance and I used Lead-free Wonder Solder Ultraclear, bought off e-bay, and it was much easier to use than some cheap lead-free solder (which is now gathering dust on my shelves). I have also heard good things about the Cardas Tri and Quad Eutectic solders, the latter being leaded.


----------



## ztsen

do i need multimeter? digital or analog?


----------



## ztsen

thx...i have this already..shd have mentioned that...   does it come with wire? anyone use there own wire?
  Quote: 





todd r said:


> Wire stripper, screwdrivers, needle nose pliers are very helpful.


----------



## Todd R

Yes it comes with it's own wire.
  Yes you should have a multi meter so you can check voltages and resistance at final assembly.


----------



## HiGHFLYiN9

Quote:


todd r said:


> Yes you should have a multi meter so you can check voltages and resistance at final assembly.


 
   
  Harbor Freight has one for a few dollars that should be enough to get you by. Or if you want to invest, a Fluke with auto-ranging is nice.

  
  Quote: 





ztsen said:


> thx...i have this already..shd have mentioned that...   does it come with wire? anyone use there own wire?


 

 The wire included was Carole brand solid core in something like PVC or PE insulation, it will work perfectly well for the application. If you'd prefer to go the boutique route, Kimber makes a nice low-strand count wire in teflon called TCSS, which I consider ideal for internal hookup. You could also use Cardas internally litzed wire, but the wiring is enamelled so you have to burn it off after stripping the ends, requiring a hot iron. With the speedball, I'd recommend using the included wiring, which appears to be 24 gauge SPC in teflon.


----------



## Nebby

What are the voltage outputs on the transformer? I'm thinking of adding an AMB ε12 muting delay pcb before the headphone out if possible.


----------



## Doc B.

It doesn't need to be the wire we supply, but I'm going to strongly recommend using solid core wire for hookup unless you are very experienced with stranded wire. Solid core will stay where you put it and the possibility of whiskers of wire poking out at a terminal attachment that could short to other terminals is eliminated. I happen to like the sound of it better too, but that is of course a personal preference.


----------



## ztsen

mind to briefly describe what improvement by using Cardas internally litzed wire?
  
  Quote: 





highflyin9 said:


> Quote:
> 
> Harbor Freight has one for a few dollars that should be enough to get you by. Or if you want to invest, a Fluke with auto-ranging is nice.
> 
> ...


----------



## ironbut

I've always thought that the sonic differences of using different chassis wire is very subtle. It can help to nudge the sound in one direction or another. In the case of Cardas, it has a good balance of good details, bass and never seems to sound harsh (even though it has good frequency extension). It also has good spacial qualities. It is a total pain to work with unless you have a solder pot and have some practice using one.
  I changed the signal wire between the RCA jacks and the pot (where I used a TKD conductive plastic) after listening to the stock amp for a while and before I installed the Speedball (I wanted to make any changes that would be more difficult once the CCS boards were crowding the access). I can't say that there was any dramatic difference with those two changes. Far less than finding the right tube combos for sure.


----------



## Armaegis

A sort of related yet unrelated question, has anyone ever tried using wire glue? http://www.thinkgeek.com/gadgets/tools/b70c/
   
  Not that I would build an entire kit using glue, but there were a couple spots during my build where I had a lot of trouble getting the iron into position without bumping other components, or I botched something and tried to fix it but now stuff was in the way, etc. Glue seems like it would be a nice simple fix for those trouble spots, though I don't know if it can handle higher current/voltage, etc.


----------



## Doc B.

We know for sure that solder will result in a reliable finished product. The money might be better spent on some different tips for your iron that might allow better access in tight spots. Good soldering is like playing an instrument or any other type of pursuit the requires muscle memory. The first time you try you may be a little disappointed that it didn't end up just like the more experienced guys can do. But it just takes some practice to get proficient at it. If you aren't goofing it up a little here and there you aren't learning anything.


----------



## HiGHFLYiN9

Quote: 





ironbut said:


> I've always thought that the sonic differences of using different chassis wire is very subtle. It can help to nudge the sound in one direction or another. In the case of Cardas, it has a good balance of good details, bass and never seems to sound harsh (even though it has good frequency extension). It also has good spacial qualities. It is a total pain to work with unless you have a solder pot and have some practice using one.
> I changed the signal wire between the RCA jacks and the pot (where I used a TKD conductive plastic) after listening to the stock amp for a while and before I installed the Speedball (I wanted to make any changes that would be more difficult once the CCS boards were crowding the access). I can't say that there was any dramatic difference with those two changes. Far less than finding the right tube combos for sure.


 
   
  Agreed on all points. The Cardas is a warm sounding wire but still maintains a good amount of detail, it's great for people who are sensitive to brightness. I've always used an iron set at 900 degrees and some solder on the tip to burn away the enamel, same way you would with magnet wire. A solder pot would do the same job a little quicker.


----------



## Todd R

Quote: 





highflyin9 said:


> Agreed on all points. The Cardas is a warm sounding wire but still maintains a good amount of detail, it's great for people who are sensitive to brightness. I've always used an iron set at 900 degrees and some solder on the tip to burn away the enamel, same way you would with magnet wire. A solder pot would do the same job a little quicker.


 
  I managed to find a very inexpensive solder pot years ago that I use. There are no controls on it, but it does the job. Sort of like this one.
  Well worth having on you bench for enameled wire like Cardas. Also good for tinning wires or any time you need a high heat solder joint.


----------



## tdogzthmn

Im sure many people using this kit have done some tube experimentations, so lets hear about your results.  I have mainly been using an RCA 6AS7G blackplate and a GE 6AS7G cleartop with halo getters.  Of the two I am prefering the GE which has more clarity and a larger soundstage than the RCA which is warmer and richer sounding of the two.


----------



## RockinCannoisseur

has anyone compared the hag bugle, piccolo,   to the  bottleneck eros or seduction??????
   
  thanks


----------



## Nebby

You may have better results asking in a new thread, as this one is for the Bottlehead Crack headphone amp. Also, It's Bottlehead not Bottleneck 
  
  Quote: 





rockincannoisseur said:


> has anyone compared the hag bugle, piccolo,   to the  bottleneck eros or seduction??????
> 
> thanks


----------



## ztsen

Just bought a Sanwa CD800a DMM hope it do a good job for my coming Crack.


----------



## RockinCannoisseur

Quote: 





nebby said:


> You may have better results asking in a new thread, as this one is for the Bottlehead Crack headphone amp. Also, It's Bottlehead not Bottleneck


 

 right u r neb, lol bottleneck still sounds cool


----------



## Doc B.

We only call ourselves Bottleneck when we are struggling to keep up with orders...though I do pretend to play a little bottleneck guitar - very badly, but through a Bottlene, uh, I mean Bottlehead prototype guitar amp.


----------



## tdogzthmn

doc b. said:


> We only call ourselves Bottleneck when we are struggling to keep up with orders...though I do pretend to play a little bottleneck guitar - very badly, but through a Bottlene, uh, I mean Bottlehead prototype guitar amp.







 Wow, I never knew the Doc was so punny!


----------



## Frihed89

Quote: 





doc b. said:


> We try to point out everywhere we can that Crack is intended for headphones of 100 ohms or higher impedance. A lower impedance, low sensitivity headphone is going to work a lot better with our S.E.X. kit, which can drive loads down to 4 ohms with 2000 mW of output. A third alternative for extreme cases of low sensitivity is our Paramount amps, which can deliver 8 watts into 16 ohms, and which we use with the notoriously difficult to drive AKG K1000s. Amongst these three choices we should pretty much have every headphone covered, save for electrostats.


 

 But it looks like only the Crack has a headphone jack and the Paramount is an integrated. I am not sure how much would have to be done to the preamp to reduce the gain (if necessary).  Wouldn't one also have to reduce the output power, even for hard to drive headphones?  Has anyone worked on this?  I am looking for a 2A3 amp (or other low power DHT) I can dedicate to a pair of LDC-2s.


----------



## HiGHFLYiN9

I think it would be very cool to have the Stereomore in[size=smaller][size=small] 45 configuration powering a pair of headphones. I'm actually surprised someone hasn't done it already   [/size][/size]


----------



## WyldRage

I was thinking about it as well for my pair of HE-5LE, since my current amps are not up to the task (the Castanet neds all its power, and they still sound off). So Doc, would you recommend S.E.X. for orthos? Or the Stereomore?


----------



## HiGHFLYiN9

I proposed the question regarding using the Stereomore for headphones on the Bottlehead forum. Doc mentioned that the Stereomore may be a little on the noisy side due to the AC heaters for headphones. Dropping a resistor in-line with the headphone output may help, but no one has tried it yet.


----------



## Doc B.

Also, IIRC you had mentioned doing this with the 45 version of the Stereomour over on the Bottlehead Forum. The SEX amp will put out pretty much the same power level as a Stereomour on 45s, probably even a 1/4W or so more than the S'mour. And indeed, it will likely be more quiet doing so.
   
  Regarding the desire to use DHTs with headphones - the DC supply of the Paramount is part of what makes it more expensive (and of course it's a pair of monoblocks which is problematic with headphone connections), but it does make a really nice DHT based headphone amp because it is very quiet. I use a pair in 300B configuration for AKG K1000s, but the 2A3 version could be plenty of power for most cans. It's direct coupled between stages in 2A3 config, so it has a little bit better resolution.


----------



## thewolf1976

How would the Crack do with Yamaha HP1 Ortho's? Just discovered these cans, thinking about trying to grab a pair but don't know a lot about what type of amp is needed. I posted in the Ortho thread also.
   
*Technical specifications:*
  Impedance: 150 ohms
  Frequency Response: 20-20,000Hz
  Diaphragm: 12 micron polyester
  Magnet: sintered ferrite or anisotropic ferrite, 55mm Diameter
  Sensitivity: 94dB/mW (Anisotropic model: 96dB/mW)
  Rated input: 3w
  Max input: 10w
  Harmonic distortion: < 0.3% at 90dB SPL


----------



## tdogzthmn

It sounds great with most cans.  If the orthos require alot of current the crack should work very well.


----------



## ironbut

I had a pair of Yamaha ortho's back when they were new (they used to sell them in record stores in the late 70's or early 80's). They were very easy to drive for planar drivers. I think the Crack wouldn't have any trouble with those.
  On the other hand, from the limited exposure that I've had with the Audeze and Fang's planars, they're a different beast altogether. I've only heard the LCD sound really good (I've heard them in about 4 different versions with more than 10 different amps)  with transformer output amps. Just like planar speakers, the amp driving them needs plenty of output power.
  Also, both of the current production planars are what the audio press like to call "ruthlessly revealing". Maybe it's just me, but almost all the amps I've listened to them on sounded pretty bad and pairing them with the planars made it pretty obvious that the amp was the issue.
  IMHO, anyone that wants to enjoy either of those headphones should be prepared climb up the amp ladder pretty far.


----------



## Nebby

Wood base still needs clear coating but I couldn't resist putting the amp together once the powder coater was done with the panel and bell. Speedball install tomorrow, should be interesting to hear the difference before and after (though I'm also changing output caps at the same time, so it won't really be comparable I guess..).


----------



## mrarroyo

Nice work there Nebby! Instead of clearcoat have you considered a wax finish?


----------



## Nebby

Speedball has been installed along with Erse output caps. The speedball definitely lowered the noise floor of the amp and improved the already good sound. I'm not very good at describing sound but it definitely sounds better to me!
   
  Mrarroyo: I considered it, but given the heat-producing nature of the amp (it doesn't get hot-hot, but it does get warm) I opted not to use a wax finish.


----------



## HiGHFLYiN9

Nice work there Nebby!  Opt for anything out of the ordinary on the inside?


----------



## Nebby

I didn't change too much:
  TKD 100k pot
  Erse MPX output caps
  Neutrik chrome bushing jack
  Powder coated plate and transformer bell
   
  and of course:
  Obnoxiously large aluminum volume knob
  (still not sure if I want to stick with the black volume knob or go for the silver knob, I have both and have been swapping back and forth)


----------



## Armaegis

I would stick with the black knob for a solid two-tone look (and I would blacken the base of the big tube as well).


----------



## Nebby

The base of the tube I'm using now is black


----------



## Armaegis

Ah, well there you go then


----------



## HiGHFLYiN9

That must be the stock tube in the photo. I got the same one with that tan fabric going around the base. I did some swapping and settled on a Sylvania 6AS7 for now.


----------



## tdogzthmn

Who's still having fun with their crack? I know I sure am!


----------



## Nebby

The Crack amp sounds fantastic! 
   
   
   
....now to finish clearcoating the wood base 
  
  Quote: 





tdogzthmn said:


> Who's still having fun with their crack? I know I sure am!


----------



## Beefy

Quote: 





tdogzthmn said:


> Who's still having fun with their crack? I know I sure am!


 
   
  I'm still waiting for my kit. Canadian customs is pathetic.
   
  *
   
  In the mean time, a quick question to HiGHFLYiN9...... how did you mount your big Solen caps? It looks like zip ties around the tops, but I can't quite make out how they are attached to the chassis plate......


----------



## Nebby

I'm going to guess zip-tie mount that's adhesively attached to the plate:


----------



## Bones13

My Crack + Speedball kit arrived end of last week.  I have a wood shop, and woodworking experience.  I have done some minor electrical work, but nothing on this scale.  I am really looking forward to the challenge.
   
  I received the Goldpoint attenuator and knob today.  I don't think I am going to go whole hog with capacitors at this point.  Getting the basic kit and the speedball upgrade up and running should do fine.
   
  Simple tube choices so far - Gold Lion EC882 with matched sections and a Winged "C" 6AS7G  (could not resist, I love my Winged "C" EL34s
   
  Aesthetically I plan a silver hammertone surface for the top and bell cap.  Black paint on the transformer plates.  Ebony stain on the wood with a rub in satin varnish.
   
  I do plan to router the edges of the box to smooth things over, but I have not chosen feet as yet.


----------



## Beefy

Quote: 





nebby said:


> I'm going to guess zip-tie mount that's adhesively attached to the plate:


 


 Cool. I've never actually seen those before!
   
  *
   
  Now I just need to decide on what output caps I am actually going to put in there. I was originally going to use 100µF Solens bought directly from Solen (one possible perk of living in Canada)...... but, since I am buying my pot from Partsconnexion I have been looking at options there and the Axon 91µF are a _really_ good price so I will probably grab those instead. However the option of bypass caps raises its head as well, but so few people talk about those I wouldn't know where to start.
   
  So I'll fire blind - Jensen 0.1µF copper foil in aluminium case are $30 a pop and look very pretty. Can anybody suggest a better option for the $$$ at Partsconnexion?


----------



## Nebby

You should be able to pick them up at your local hardware store near where the zipties are. At least that's where I found them.


----------



## Doc B.

There is a slightly different type of  zip tie hold down that we use, that along with a sticky foam mount has a dimple in the center that you can use as a template to drill a hole, so that you can secure it with a screw and nut. This can turn out to be useful in an amp where the chassis plate gets warm, as the glue on the foam pads can break down over time from the heat.


----------



## Nebby

I just realized mine also have a spot for a screw in the middle, I think I'll go ahead and screw them in next chance I get 
	

	
	
		
		

		
			





 Thanks for bringing up the idea!
  
  Quote: 





doc b. said:


> There is a slightly different type of  zip tie hold down that we use, that along with a sticky foam mount has a dimple in the center that you can use as a template to drill a hole, so that you can secure it with a screw and nut. This can turn out to be useful in an amp where the chassis plate gets warm, as the glue on the foam pads can break down over time from the heat.


----------



## HiGHFLYiN9

Quote: 





nebby said:


> I'm going to guess zip-tie mount that's adhesively attached to the plate:


 
  That's exactly what I used. You can pick them up in the electrical section of home depot (they have holes for screws too). I also use them on circuit boards with metal cased capacitors to prevent any shorts if there are multiple through-holes.
   
   
   Quote: 





			
				Beefy said:
			
		

> So I'll fire blind - Jensen 0.1µF copper foil in aluminium case are $30 a pop and look very pretty. Can anybody suggest a better option for the $$$ at Partsconnexion?


 

  There's a better $ per performance option out there for PIOs, check out ebay at take a look at the Russian PIOs. http://cgi.ebay.com/Russian-PIO-Capacitor-K40Y-9-0-1uF-400V-1pc-or-more-/380243439777?pt=Vintage_Electronics_R2&hash=item58884670a1
  There are plenty of builders that use them, along with the teflon versions, which are massive and probably wouldn't fit without some unique mounting.
   
   
  If you prefer name brand stuff and are looking for bang for the buck; check out Sonicraft Sonicaps and DiyHifiSupply Obbligato caps. They aren't PIO though.


----------



## maverickronin

I managed to completely shear a lead off one of the rectifier diodes.  
	

	
	
		
		

		
		
	


	



   
  I tried some of that wire glue which I had sitting around but never used before, but its not very strong at all.  Am I likely to be able to pick something with the same specs at radio shack?


----------



## Doc B.

Contact Eileen during business hours tomorrow and she will put a replacement in the mail to you. If you want to try to find a replacement locally, it is a UF4007 rectifier. One can sub in a more common 1N4007. It makes more reverse recovery spike noise than the UF (ultrafast, soft start) version if you look at the power supply output on a scope. This might possibly be perceived as a bit of edge being added to the sonics, but it will function properly in the power supply and get you up and running.


----------



## maverickronin

Thank you very much!


----------



## druelle

Well after taking my sweet old time, I've finally finished building the Crack and Speedball upgrade. What a sense of accomplishment (it's my first ever foray into DIY and I'm already a self-confessed addict!)  I still haven't finished putting the wooden base together so the innards of the amp are sitting on my bedside table, but man oh man does it ever sound good!  Compared to my Darkvoice 336, it just sings with the HD650s!  I've only got a few hours on the Crack so far, so it hasn't been fully burnt in, and I'm sure it will only get better with age.
   
  I'm planning on upgrading the 12AU7 (I've already swapped the 6080 out for a 5998) and would like to buy 2-3 quality tubes but not spend too, too much money on them.  There are so many choices for 12AU7, but I was leaning towards one or some of the following:
   
  * Siemens 5814A (1980s)
  * Mullard CV4003
  * RCA clear-top 12AU7A
  * maybe splurge for a Telefunken Germany (not sure smooth or ribbed plates)
  * maybe splurge for a Amperex 7316 (not sure tall or short plate)
   
   
  If anybody could offer their insight (especially when paired with the HD650s) or other suggestions, I'd really appreciate it.
   
  Enjoy the music!


----------



## Nebby

I found that the 5998 with the Mullard CV4003 or the RCA worked very well. Similar sounding with the RCA a bit more tubey/warmer from what I remember.


----------



## maverickronin

I keep managing to break things.  This time its one of those tiny red LEDs.  Its the right way around but it won't light up.  My DMM's continuity mode will make the first one light up a little, but the second one stays dark, both ways.  Does it have any special specifications or is it just a 1.2V red LED?  Would I have to replace the one that works with an identical one as well?


----------



## Nebby

I'd say give Bottlehead a call, they probably chose the led's for reason and I hear they're pretty good about sending out replacement parts. The typical forward voltage for the HLMP-6000 series is 1.6V and if you were to swap in a different led you would indeed need to swap out the other one as well.


----------



## Beefy

Changing the LED for something different is a bad idea. The Vf of the LED sets the operating point of the 12AU7, and I believe that the resulting plate voltage of the 12AU7 sets the operating voltage of the 6080, so a slight change might have significant negative effects.
   
  Also, even if you can match the Vf, the dynamic impedance might be different.
   
  Take home message...... contact Bottlehead and ask for a replacement.


----------



## larcenasb

Has anyone heard the Bottlehead with AKG K601s?
   
  I had a vintage Marantz receiver that gave my K601s a warm, tubey sound that was also powerful -- I fell in love with the combo but the receiver broke. Will the Bottlehead give a similar sound (smooth and powerful) or do receivers handle headphones better 'cause of their power?
   
  Thanks in advance.


----------



## WyldRage

Quote: 





larcenasb said:


> Has anyone heard the Bottlehead with AKG K601s?
> 
> I had a vintage Marantz receiver that gave my K601s a warm, tubey sound that was also powerful -- I fell in love with the combo but the receiver broke. Will the Bottlehead give a similar sound (smooth and powerful) or do receivers handle headphones better 'cause of their power?
> 
> Thanks in advance.


 

 I have both and I just tried it with 3 different tubes. With the NOS 5963 in the kit, I find that the sound is bright, with a subdued bass that lacks definition. With a Electro-Harmonix 12BH7, the sound is more neutral, but lacks extension on both sides, especially the bass. With a EH 12AU7, the amp sounds better: it's still bright, but the bass is present and well-defined, if a bit lacking for my tastes.
   
  In any case, the Crack has no problem driving them.


----------



## tdogzthmn

wyldrage said:


> In any case, the Crack has no problem driving them.







 How's the detail and bass extension on the K601? I sometimes miss mine.


----------



## Doc B.

Quote: 





nebby said:


> I'd say give Bottlehead a call, they probably chose the led's for reason and I hear they're pretty good about sending out replacement parts. The typical forward voltage for the HLMP-6000 series is 1.6V and if you were to swap in a different led you would indeed need to swap out the other one as well.


 

 Yeah, you really want to stick with the HLMP-6000 (V drop is actually 1.56V). We are in Chicago until next Wednesday (doing a presentation for the Chicago Audio Society on Sunday). Give us a call or email next week and we will be happy to send out a replacement LED.


----------



## ironbut

Quote: 





larcenasb said:


> Has anyone heard the Bottlehead with AKG K601s?
> 
> I had a vintage Marantz receiver that gave my K601s a warm, tubey sound that was also powerful -- I fell in love with the combo but the receiver broke. Will the Bottlehead give a similar sound (smooth and powerful) or do receivers handle headphones better 'cause of their power?
> 
> Thanks in advance.


 
  The Crack responds very well to tube rolling. I would venture to guess that with the right tube combo, you should be able to tailor the sound just about any way you want (there are limits of course). If you like a warmish sound, you'd be better off listening to the stock amp and skip the Speedball upgrade until you've got a good handle on the way it sounds without it.
  I've found that all the Bottlehead gear that I've heard have fantastic bass. If that's what you mean by powerful, you'll probably love the Crack.


----------



## larcenasb

Thank you very much for responding WyldRage and ironbut -- I'll post my comments about the K601 + Crack combo once I get it. Cheers.


----------



## Mak333

Quote: 





larcenasb said:


> Thank you very much for responding WyldRage and ironbut -- I'll post my comments about the K601 + Crack combo once I get it. Cheers.


 

 I'm also interested to see how the BottleHead Crack sounds with my newly acquired HD600s.  I just ordered the amp today so hopefully we are pushing the limits for the order quantity 
	

	
	
		
		

		
			





  I'm very new to serious audio equipment and I think the HD600s straight from an X-Fi sound card sound amazing - Lack of bass ofcourse, but everything else sounds great.  I wonder how much this amp will enhance my listening experience.


----------



## thewolf1976

Have any of you added an input to the Crack? I need two inputs, rather not have to unplug the rca cables. Can anyone recommend a switch, or do you know what kind of switch Bottlehead uses for their other amps? Also the rca inputs they use? I sent an email, but I think they are out of the office this week.
   
  I ordered my Crack back on the 11th, maybe next shipment!


----------



## tdogzthmn

The crack only has a spot on the panel for one pair of RCA inputs to be installed.  If you wanted to have multiple inputs I would suggest buying a separate device.  I dont know of any off the top of my head but I am sure you can find one.


----------



## thewolf1976

I thought about building a switch box, but the cost gets a little high with the rca's and the extra cables.
   
  Looks like there is enough room to add a pair of rca's and the switch knob. What do you think?
   
  Hopefully bottlehead will get back to me. I was hoping to use the parts they use in their multi input amps, but I'll do whatever.


----------



## Doc B.

Hi guys,
   
  Yes, we were out of town and just getting back to it this morning. It will take a couple of days to get through all of our correspondence. In the meantime - the input selector toggle switch setup of our Quickie amp could be used. Or you could just buy a DPDT toggle and a couple of RCAs from Radio Shack. You just connect the signal + from the right channel jacks to one pole and the + of the left channel jacks to the other pole. Then route the signal from the switch to the volume pot.


----------



## thewolf1976

Doc,
   
  Thanks for the reply. That is what I was thinking, use the switch from the quickie. I emailed queen for the specifics. I wanted to use the same materials, knobs, rca to match the Crack. Just aesthetics.


----------



## ztsen

I just received my package. But my wood base kit and the rubber feet already assembled when I open the box. one of the wood have already broken but I cant find the broken piece.
  Anyone have such issue before?


----------



## Doc B.

That's just a natural imperfection in the wood and it's on the inside where it won't show. It's typical of the millwork on the bases we include. Yours happened to be one we had glued up for a custom project that was canceled, so we though we would be nice and send it on to a customer to save them a little construction time. If you would prefer an unassembled base we can exchange it for you, no problem.


----------



## dongringo

Now that's customer service. 
	

	
	
		
		

		
			




   
  I really need to start my Crack kit that's been sitting here for 3 months. What can I say? I got hooked on cycling and the season is short in the Pacific NW.


----------



## ironbut

Another alternative is to make a new panel for multiple inputs and a switch. Here's a mock-up made of some aluminum stock I get at Orchard Supply Hardware.
  The back of the case seems like a logical spot so you could mask off the back and use a jig saw to cut out the bottom a little smaller than the new panel (it might even be worth it to make the hole 1/2 and inch taller to get better airflow from the back to the vents).
  The mock up just have some spare RCA's that I have laying around and a nice switch that I got from Michael Percy ( I can't remember what it was for!).




   
  This way of adding inputs would make it harder to pull the chassis plate off to work on the amp (remove the 4 screws) but I think it would be better than trying to cram it all onto the top plate.
  You can buy inserts to put in the two holes where the original jacks were and if you decided to get fancy, Orchard also has copper plate stock (I think the 10x4 inch aluminum was under $10 and so was the copper).
  BTW, that isn't the right type of switch. It's just there to illustrate the idea.


----------



## ztsen

I only have a WBT silver solder which I bought a kit from Audio-gd accesories left over, according to the web site it is 4% fine silver content but the Crack manual mentioned below:
   
  Solder - we recommend standard 60/40 or 63/37 tin/lead solder as the easiest to work with. 2% sil-ver solder is OK, but stay away from 4% silver solder. It does not flow well. If you are using an ad-justable solder station you will want to set the temperature to about 650-700 degrees.
   
   
  In this case, I should not use the WBT silver solder, am I right?


----------



## WyldRage

You can use it, it's simply harder to use.


----------



## ztsen

there are below:
  ( ) 2- #8 round lockwasher (large)
 ( ) 2- #6 round lockwasher (small) 
   
  2 x #8 round lockwasher used for safety ground
  1 x #6 round lockwasher used for the 9 pin socket
   
  but look like i need a #8 round lockwasher for the transformer. the remaining #6 lockwasher doesnt seem fit...
   
  how's you guys do for this?


----------



## RedBull

Quote:


highflyin9 said:


>


 


 Eeasily the best looking Crack casing I've ever seen.
   
  Wow, those HUGE caps remind me of Aromatherapy candles


----------



## tdogzthmn

^ It's audio therapy.


----------



## HiGHFLYiN9

Thanks Redbull.
   
  I just recently added a vintage pilot light and a power bypass cap so I'll throw up some new pics:
   



   
   



   
   
   



  Vintage Photograph style in Photoshop 
	

	
	
		
		

		
		
	


	



   
   
*EDIT: I've had countless people ask about how to get a badge made like the one above. Unfortunately my contact is no longer in the promotional products business so I do not have any referral information. *


----------



## Beefy

Auricap as a power bypass? Money money than sense, dude


----------



## Nebby

Hey now, AC waves have feelings too!


----------



## HiGHFLYiN9

Yeah yeah, I have a few extra solid-lead Auricaps in my parts bin because they were on sale; stuff is always cheaper when you already have it. Besides Beefy... if you were an amp I'm sure you'd want an Auricap power bypass cap


----------



## ztsen

anyone  can help?
  Quote: 





ztsen said:


> there are below:
> ( ) 2- #8 round lockwasher (large)
> ( ) 2- #6 round lockwasher (small)
> 
> ...


----------



## HiGHFLYiN9

Quote: 





ztsen said:


> anyone  can help?


 

 Not sure if Singapore has something like a Home Depot, but a #8 lockwasher will probably set you back about 5 cents, why not just pick one up?


----------



## ztsen

Thanks, will do.
   
  Do you think is a good idea to reverse the position of the power entry?
  My power cord can easily touch the transformer with the original position of the power entry.

  
  Quote: 





highflyin9 said:


> Not sure if Singapore has something like a Home Depot, but a #8 lockwasher will probably set you back about 5 cents, why not just pick one up?


----------



## RedBull

Quote: 





tdogzthmn said:


> ^ It's audio therapy.


 
   
  Hahah, you're right.

  
  Quote: 





highflyin9 said:


> I just recently added a vintage pilot light and a power bypass cap so I'll throw up some new pics:
> 
> 
> 
> ...


 

 I can buy yours just from the look alone, pretty ...


----------



## RedBull

Quote:


ztsen said:


> there are below:
> ( ) 2- #8 round lockwasher (large)
> ( ) 2- #6 round lockwasher (small)
> 
> ...


 

 I wish I understand what you guys are talking about


----------



## HiGHFLYiN9

Quote: 





ztsen said:


> Thanks, will do.
> 
> Do you think is a good idea to reverse the position of the power entry?
> My power cord can easily touch the transformer with the original position of the power entry.


 
  Are you worried about the heat of the transformer touching the power cord?


----------



## ztsen

yes. anyway, i do it reverse just to make my life easier to try different power cord.  
	

	
	
		
		

		
		
	


	



  
  Quote: 





highflyin9 said:


> Are you worried about the heat of the transformer touching the power cord?


----------



## Beefy

Can somebody do me a _huge_ favour and measure the voltage drop across the two 270R resistors in the Crack's power supply? I'd like to work out how much power they dissipate.
   
  Thanks!


----------



## dwh91307

I get 19.2v across each 270R on my Crack.
  
  Quote: 





beefy said:


> Can somebody do me a _huge_ favour and measure the voltage drop across the two 270R resistors in the Crack's power supply? I'd like to work out how much power they dissipate.
> 
> Thanks!


----------



## Beefy

So that would be consistent with the amp drawing ~70mA, and the 270R resistors dissipating ~1.4W each. Sweet, dropping a nice 5W carbon film in there will be A-O-K.
   
  Thanks again!


----------



## HiGHFLYiN9

Anyone want to go halfsies on two S.E.X. kits? They're $422.10 when you buy two or more!


----------



## Armaegis

Argh, very tempting... except with shipping to Canada I'm not too sure how that would work out.


----------



## HiGHFLYiN9

USPS is usually the best way to go with shipments to Canada, not sure exactly how much it would be though


----------



## diego

Are the 2 resistors in series and that's the total for the 2 channels?
  
  Quote: 





beefy said:


> So that would be consistent with the amp drawing ~70mA, and the 270R resistors dissipating ~1.4W each. Sweet, dropping a nice 5W carbon film in there will be A-O-K.
> 
> Thanks again!


----------



## Beefy

Yes. The power supply is CRCRC.
  
  Quote: 





diego said:


> Are the 2 resistors in series and that's the total for the 2 channels?


----------



## ztsen

I done the crack but not the speedball yet.
   
  I find it a bit at towards the bright side with T1. Is it due to still running in or this is the sound character of Crack?


----------



## WyldRage

From my experience, it's the sound character.


----------



## Todd R

Quote: 





ztsen said:


> I done the crack but not the speedball yet.
> 
> I find it a bit at towards the bright side with T1. Is it due to still running in or this is the sound character of Crack?


 


  My experience says it's the T1


----------



## Beefy

A question of optimisation...... with the Speedball installed, the amp should have better PSRR. So could there be some benefit in making the filtering a little less aggressive in order to boost the B+ a bit?
   
  I've simmed the Crack up in PSUD2, with 150VAC supplied at 42R (measured) transformer resistance, CRCRC with 220µF 850mR ESR caps and 270R resistors, and a 72mA CCS load. Final result is ~155.5VDC with ~0.8mV ripple. Switching to 135R on the either the first or the second filter resistor (two 270R in parallel to make it easy) gives me ~164.9VDC with ~2mV ripple.
   
  My thinking is that the CCS's now have almost 10V more headroom which should translate into a bit more voltage swing, and that the CCS should be able to filter out the extra ripple, at the expense of a little bit more heat on the CCS transistors. My output caps are going to be 250V film jobbies, thus can handle the higher voltage.
   
  Thoughts?


----------



## nikongod

The PSRR of the output stage is unaffected by the speedball. Whether you can run it with the more ripply supply or not... I guess you would have to test. Additionally, if the CCS's already have "enough" headroom (the tube(s) clips before the CCS runs out of voltage) more voltage just means more heat for them to deal with. 
   
  In the end, I would probably not do it.
  My line of reasoning goes like this: The stock amp has more than enough voltage swing for pretty much any headphone you would realistically use with it. Why risk more noise for more voltage swing when you already have more than enough voltage swing? More voltage swing is DEFINITELY not better if it comes with more noise...
   
  Build a little parafeed transformer box if your bored. That was a very worthwhile expenditure of a few bills. Crack + Outboard transformer + Low impedance headphones = awesometoast!


----------



## Beefy

Pretty sure that the Speedball adds a CCS for the output stage as well...... or am I mis-reading the schematic as to how it is connected?
   
  But point well taken on whether the tubes are clipping due to voltage or 'other'. It was actually your post much earlier in the thread that had me semi-worried about voltage swing; you noted it clipped at 12V P-P which seemed really low to me. Did you perhaps mean 12VRMS?


----------



## nikongod

Quote: 





beefy said:


> Pretty sure that the Speedball adds a CCS for the output stage as well...... or am I mis-reading the schematic as to how it is connected?
> 
> But point well taken on whether the tubes are clipping due to voltage or 'other'. It was actually your post much earlier in the thread that had me semi-worried about voltage swing; you noted it clipped at 12V P-P which seemed really low to me. Did you perhaps mean 12VRMS?


 

 Im pretty sure it was p-p. 12vp-p is still a lot, and I did get it up to 15vp-p before things started to get really ugly. For fun, measure how much voltage swing you use. Most people stay well below 2.8vp-p/1vrms with anything except electrostatics.
   
  The speedball upgrade does add a CCS for the output stage. CCS's only improve PSRR when they are between the tube and the power supply. The CCS in the output stage is "under" the tube. The PSRR of the output stage is the PSRR of a cathode follower, which is not as good as a CCS loaded common cathode (gain stage) OTOH, a cathode follower has WAY better PSRR than a resistor loaded gain stage


----------



## maverickronin

Quote: 





nikongod said:


> Build a little parafeed transformer box if your bored. That was a very worthwhile expenditure of a few bills. Crack + Outboard transformer + Low impedance headphones = awesometoast!


 

 That sounds awesome.  Got any plans, parts lists, or instructions?


----------



## Doc B.

Just to clarify here, the Speedball adds a CCS to the output stage and also to the input stage. The input stage does indeed see better PSRR because of the CCS loading the plate.


----------



## nikongod

Quote: 





maverickronin said:


> That sounds awesome.  Got any plans, parts lists, or instructions?


 

 I dont really do instructions. Sorry. I have a schematic, take it as is. 
   

   
  The 0.625W setting is MUCH quieter than the 10W setting. I'd start somewhere in the middle and re solder as necessary. The switch may be total overkill, but I can never settle on just 1 setting knowing there are other settings....


----------



## TobyTyler

I am the happy owner of the Crack and transformer box built by nikongod from earlier in this thread.  I have used it with my AKG K501 to much satisfaction.  I started out at the lowest setting on his advice.  It was very quiet, especially compared to beyer DT990-600 ohm without using the transformers.  So I tried the next setting and it was a big difference.  I would say at setting 2, the volume levels are pretty close between the beyer 600 ohm straight out of the Crack and the K501 through the transformer box.  I suppose I should experiment more, but I'm liking what I'm hearing too much.


----------



## maverickronin

Quote: 





nikongod said:


> I dont really do instructions. Sorry. I have a schematic, take it as is.


 


  Thank you very much!


----------



## Nebby

Any suggested vendors for the Speco transformer? I'm going to buy it from allied electronics unless you have a recommendation elsewhere 
	

	
	
		
		

		
		
	


	



  
  Quote: 





nikongod said:


> I dont really do instructions. Sorry. I have a schematic, take it as is.
> 
> 
> 
> The 0.625W setting is MUCH quieter than the 10W setting. I'd start somewhere in the middle and re solder as necessary. The switch may be total overkill, but I can never settle on just 1 setting knowing there are other settings....


----------



## nikongod

Quote: 





nebby said:


> Any suggested vendors for the Speco transformer? I'm going to buy it from allied electronics unless you have a recommendation elsewhere


 

 I got mine from allied, there are better prices elsewhere but allied is quite reputable and it was easy to find a nice enclosure with them


----------



## Nebby

Hah! Thanks for reminding me I need an enclosure as well!
  Quote: 





nikongod said:


> I got mine from allied, there are better prices elsewhere but allied is quite reputable and it was easy to find a nice enclosure with them


----------



## ztsen

T1 have middle mid dominion but not upper mid/lower high and not bright.
  If only Crack, the power stage 6080 really too bright, 6H13C will be more suitable and less bright.
   
  I done the speedball upgrade, which is pretty fast.
   
  Initial impression, is all the excessive higher mid is gone, smoother, more punchy, more transparent but slightly dark. (Impression using back stock 6080)
  The stock EH12AU7 is harsh. (Never have gd impression on EH) So I use JJ ECC802S Gold.
   

  
  Quote: 





todd r said:


> My experience says it's the T1


----------



## RedBull

Quote: 





doc b. said:


> Just to clarify here, the Speedball adds a CCS to the output stage and also to the input stage. The input stage does indeed see better PSRR because of the CCS loading the plate.


 


 Hi Doc,
  I'm not expert in electronic, just want to understand that in layman term 
	

	
	
		
		

		
		
	


	




  Does it means it works like a buffer between Preamp to Power stage?
   
  Thanks.


----------



## Beefy

No, nothing like that. A CCS is a way of loading the tube. Here is a good primer written in the context of parafeed amps, but the principles apply to the tubes in the Crack as well.
   
  http://www.ecpaudio.com/pdf/parafeed_basics.pdf


----------



## ironbut

It's been a while now so the "new toy syndrome" should be worn off of most members Crack amps by now.
  I'd like to see what cans folks are using with it (especially the lower impedance).
   
  I'm currently using my AD2000 and HD800's and loving it.
  Tubes are Tung-sol 5998 and Mullard 12au7 or CBS Hytron 5814a.


----------



## HiGHFLYiN9

I'm using mine almost entirely with my DT990 250ohm and some NOS Sylvania tubes. I tried a pair of Headphile Alessandro MS-2s with it and didn't really care for the synergy.
   
  I'll be building a S.E.X. in the coming months which should do the Alessandros justice.


----------



## RedBull

Quote:


beefy said:


> No, nothing like that. A CCS is a way of loading the tube. Here is a good primer written in the context of parafeed amps, but the principles apply to the tubes in the Crack as well.
> 
> http://www.ecpaudio.com/pdf/parafeed_basics.pdf


 

 Don't completely understand, but I got a slight hint 
	

	
	
		
		

		
			




  Thanks Beefy ...


----------



## milosz

I usually use mine with Sennheiser HD800s.
   
  By the way, I tried my Audeze LCD-2's on the Crack / Speedball.  Didn't drive the 50-ohm LCD-2's, really.
   
  One would expect that this amp wouldn't like the LCD-2's.  But I had to try it, and report on it here.


----------



## ironbut

Thanks for trying the LCD-2's. After living with planar magnetic speakers for a long time (and have tried a gazillion amps with them), I had a feeling that they wouldn't pair up very well.
  The only other cans that I've tried that didn't work very well with the Crack was a pair of K701's (but, I never was very fond of them anyway).
  With the HD800's, it's pretty much a tie with my Zana.


----------



## andrew3199

I would love to get in on some Crack and while my soldering skills would get the job done it would look very messy and being so "anal retentive" as I am would want the point to point wiring to look perfect. My plan is to buy the kit, get the top plate painted and the wooden enclosure stained to my liking then get the amp shipped of to a builder to get built, it would have to be someone with impeccable amp building and soldering skills.......I wonder if I could get JMT out of retirement for one more build.....


----------



## Armaegis

Quote: 





ironbut said:


> The only other cans that I've tried that didn't work very well with the Crack was a pair of K701's (but, I never was very fond of them anyway).


 
  I was not a fan of the Crack + K701 either. The K240 Sextett on the other hand is a beautiful match.


----------



## maverickronin

Just finished mine a few days ago.
   
  Its great with my K340s.  They got HUGE upgrade in quality over the amp in my Maverick D1.  My HD650s sound great as well, though they didn't get nearly as huge of a leap as the K340s got.  Those suckers are hard to drive.
   
  Also quite surprisingly my Koss KSC75s sound awesome from the Crack.  $13 headphones that scale with amping, wonder of wonders.


----------



## tdogzthmn

Quote: 





ironbut said:


> Thanks for trying the LCD-2's. After living with planar magnetic speakers for a long time (and have tried a gazillion amps with them), I had a feeling that they wouldn't pair up very well.
> The only other cans that I've tried that didn't work very well with the Crack was a pair of K701's (but, I never was very fond of them anyway).
> With the HD800's, it's pretty much a tie with my Zana.


 

  
  You feel the crack drives the HD800 comparatively to the Zana? Interesting.


----------



## Armaegis

Quote: 





maverickronin said:


> Just finished mine a few days ago.
> 
> Its great with my K340s.  They got HUGE upgrade in quality over the amp in my Maverick D1.  My HD650s sound great as well, though they didn't get nearly as huge of a leap as the K340s got.  Those suckers are hard to drive.
> 
> Also quite surprisingly my Koss KSC75s sound awesome from the Crack.  $13 headphones that scale with amping, wonder of wonders.


 

  
  I was not that satisfied with the K340s. Then again, I felt kinda unsatisfied with them out of just about every amp I had except the G&W which pumped out 2W of power, and even then I think it wanted more. Those K340s are hungry hungry beasts. I think the only way to drive them properly is to reterminate them to balanced then run the ends directly off speaker terminals (get a small T-amp or something).


----------



## maverickronin

Quote: 





armaegis said:


> I was not that satisfied with the K340s. Then again, I felt kinda unsatisfied with them out of just about every amp I had except the G&W which pumped out 2W of power, and even then I think it wanted more. Those K340s are hungry hungry beasts. I think the only way to drive them properly is to reterminate them to balanced then run the ends directly off speaker terminals (get a small T-amp or something).


 

 That may be.  The Crack is the strongest amp I've heard them from so far though.  I'll have to try some more experimentation then.  Thanks for the heads up.


----------



## ironbut

Quote: 





tdogzthmn said:


> You feel the crack drives the HD800 comparatively to the Zana? Interesting.


 

 I feel the ZD is more accurate but the Crack is more fun. Because of that, I find myself listening to the Crack/HD800 more often. If I'm analyzing the sound of something, I usually go for the Zana  with either the 800's or my AD2000's.


----------



## larcenasb

So I'm just about ready to buy the Bottlehead Crack, however, a very real hesitation has gotten a hold over me. I'm nervous about shelling out $219 to be disappointed, as I've done in the past, unfortunately. I have a question WyldRage:
   
  With my Shanling PH100, my AKGs get very fatiguing, very quickly -- I'm looking for a tube amp to warm things up the way my vintage Marantz 2235 receiver used to. I am under the impression that tubes offer that, but when you say the K601 sounds "bright" with the Bottlehead, I start to turn away. Bright does not mean fatiguing right?
   
  And if it's not too much trouble, could you give some more impressions of the Bottlehead with the K601?
   
  Examples from my experience:
   
  - With the Shanling, Nirvana's rendition of David Bowie's_ The Man Who Sold the World_ bites its way into my eardrums, the sound is not at all engaging, and I can barely hear Krist's bass guitar, sounding very light. With the Marantz, I can bathe in the sound, searing guitars are smooth and airy, the bass is equal with the rest of the mix, and it makes me utterly happy; my sonic bliss.
   
  - When listening to the end of _Breakfast at Tiffany's_, Henry Mancini's score sounded perfect (to me) with the Marantz, the bass came alive with power and depth I've never heard with the K601 before, the whole sound was weightier, pure, organic; all these words I read on this forum finally becoming realized. But as I've said earlier in this thread, the Marantz is broken and the Shanling sounds exactly the opposite to me; lean, fatiguing... if the mids and highs have a loudness of 8/10, then the bass has 3/10.
   
  So I know the sound I want is possible with the K601, I'm in search of a headphone amp that'll achieve it, but is the Bottlehead Crack my ticket? If not, what would you recommend, based on my descriptions? Anyone's input would be greatly appreciated. Thank you.


----------



## WyldRage

I compared it, with the k601, to my other amps here: http://www.head-fi.org/forum/thread/503622/showdown-3-diy-tube-and-hybrid-amps-millett-hybrid-minimax-bottlehead-speedball-crack-hagerman-castanet/15#post_6975208


----------



## tdogzthmn

I dont have a K601 but I do have a K400 and K500 and both come through blazingly clear.  You really hear how the amp controls the music.  
  Quote: 





larcenasb said:


> So I'm just about ready to buy the Bottlehead Crack, however, a very real hesitation has gotten a hold over me. I'm nervous about shelling out $219 to be disappointed, as I've done in the past, unfortunately. I have a question WyldRage:
> 
> With my Shanling PH100, my AKGs get very fatiguing, very quickly -- I'm looking for a tube amp to warm things up the way my vintage Marantz 2235 receiver used to. I am under the impression that tubes offer that, but when you say the K601 sounds "bright" with the Bottlehead, I start to turn away. Bright does not mean fatiguing right?
> 
> ...


----------



## HiGHFLYiN9

After becoming addicted to my Crack, I had to get my next fix from the Seduction build. Here's some photos to enjoy 
	

	
	
		
		

		
			




   
   




   
   




   
   




   
   
  It features the following upgrades:
  C4S Upgrade Board
  Gold Obbligato Caps (0.47uf and 0.1uf)
  Cardas Rhodium input and output RCAs
  Slightly nicer than stock Pany and Neutrik caps in the power supply
  Cardas, Kimber and Neotech Teflon wiring.
  Teflon Noval Sockets and PCBs
  Takman Carbon Film Resistors


----------



## RedBull

Pretty!  Where's the transformer?


----------



## HiGHFLYiN9

Quote: 





redbull said:


> Pretty!  Where's the transformer?


 

 It's that little box on the bottom that says Bottlehead PT-1


----------



## RedBull

Oh, you tweak it to face down, smart! 
	

	
	
		
		

		
		
	


	




 look neat.


----------



## Beefy

Quick clarification: is this the same LED as used in the Crack? HLMP-6000
   
  Part numbers match obviously, but there are a lot of HLMP-6xxx in the datasheet, and I want to make sure I am looking at the right one.


----------



## thewolf1976

Crack building first steps. How can I get the tung oil to soak in on the top corners? I think a little glue overlapped. I sanded lightly to remove, but no luck. Could I wet sand or use mineral spirits to open the grain?


----------



## HiGHFLYiN9

I had a little bit of the same problem with the glue. I sanded down the base using an electric sander with 220 grit and spent a little bit of extra time on the corners. That took care of most of it in my case.


----------



## ironbut

Glue on the miters is always an issue if you don't realize that when you first assemble two pieces of wood.
  Of course, if you know that you can tape off the the miter before you glue it together or just be super careful to wipe any off before it dries. No matter how many times I ask carpenters (particularly with veneered wood), it usually falls on dead ears unfortunately.
   
  In your case, the first thing to try is to tape off one side of the miter and take some sandpaper that's dipped in your tung oil and work on that corner till it blends in. Once you get one side done, do the other. Unfortunately, your tape won't want to stick to the fresh oil so you just have to be careful not to mess up the side that you've already done.
  In extreme cases where the glue has penetrated deep into the grain and pores, the easiest way is to tape off one side at a time and use a small, ultra sharp chisel to remove the glue, then even out the top with a sanding block. Always finish with hand sanding with exactly the same grit that you used on the rest of the base. Avoid cross graining since it could end up being too dark.
  As always, if you need to do serious surgery (like with a chisel), practice in an inconspicuous spot first.


----------



## Armaegis

Would it not have been easier to oil/finish the wood before glueing it together?


----------



## Beefy

Glue won't stick to oiled wood.


----------



## Armaegis

Can you just stain the outer surfaces then? or does oil not work that way?


----------



## Beefy

Oil does not work that way, it is designed to penetrate into the wood. In any case, you should *always* glue before you finish the wood, because it is easier to clean up glue mistakes while finishing, than to repair finishing mistakes if you damage it while gluing.


----------



## thewolf1976

Thanks everyone, It is looking pretty good. I think I will wet sand with a little tung oil to really even it out. Some of it is the end grain.  Got the paint on the cover, came out pretty well. I am going to let the top cure over the weekend, start assembly Monday!


----------



## Armaegis

Quote: 





beefy said:


> Oil does not work that way, it is designed to penetrate into the wood. In any case, you should *always* glue before you finish the wood, because it is easier to clean up glue mistakes while finishing, than to repair finishing mistakes if you damage it while gluing.


 

 Ah, good to know. I finished before glueing... but I kinda did a sloppy job on both


----------



## zlobby

I am probably going to be buying one of these kits to use with my hd600.  I also listen to grado sr-80s from time to time.  I know this amp isnt supposed to be great for low ohm cans, but can anyone attest to it from personal experience?


----------



## HiGHFLYiN9

This is a bargain priced kit and the sound quality is fantastic with higher impedance cans, but I had a listen to a pair of MS2is with the Crack and it wasn't the best I've heard them. Listening to the same cans with a Millet MiniMAX and M Cubed yielded more dynamic results.


----------



## Armaegis

Crack is fantastic with the HD600, not so much with the SR80 (or MS1, or HF-2).


----------



## tdogzthmn

Quote: 





armaegis said:


> Crack is fantastic with the HD600, not so much with the SR80 (or MS1, or HF-2).


 


  Hmm, I have been interested in an SR325 but sign's are pointing to this being a poor match.  Also I have new tubes on the way, one being a Tung-Sol 5998


----------



## Armaegis

Bottlehead designed the Crack for high impedance cans. My experiences seem pretty consistent with that. It's not that low impedance cans sound bad, just... *shrug*.
   
  I'd be curious to see someone take one of the Beyers with the 32 vs 250 vs 600 ohm and see how they sound coming out of a Crack.


----------



## hypoicon

The Crack works well with my DT990s (600 ohm) and sounds terrific (as many others have remarked) with my Senn HD-650s. It actually doesn't sound bad with my HF-1 grados, or my RS-1s; but as others have remarked as well, it's not the best match. Other amps I own sound better.


----------



## Doc B.

Quote: 





armaegis said:


> Bottlehead designed the Crack for high impedance cans.


 


 Yes, that was the intended usage from the start and we have gone to some lengths to emphasize this. The amp will make good sound with lower impedance headphones, but it is not going to allow them to give their absolute best bass performance. This is simply going to be a matter of taste in a lot of cases.


----------



## Neogeo333

I want to thanks Doc for this wonderfull amp, using it witha DT 990 600ohm.  One question for Doc, i remember that you said back in the Bottle head forums that if used witha  5998 tube it might  work well with cans low as 70ohm?  I wonder if it can do better with WE 421A?


----------



## Skylab

Quote: 





neogeo333 said:


> I want to thanks Doc for this wonderfull amp, using it witha DT 990 600ohm.  One question for Doc, i remember that you said back in the Bottle head forums that if used witha  5998 tube it might  work well with cans low as 70ohm?  I wonder if it can do better with WE 421A?


 


  The WE 421A and the Tung-Sol 5998 are the exact same tube.  Only Tung-Sol made this tube; the WE 421A is just a rebranded 5998.


----------



## Beefy

And even if the 421A do sound better through some phantasmagorical effect, it is not because of the output impedance which is still the same.


----------



## diego

The output impedance using 5998s is probably lower than 80, depending on the exact operating point which I don't know. As a reference, I have a different amplifier with an output impedance of 65 and it sounds good with my 62 ohm AKG 701. However, the bass is tighter with my 300 or 600 ohm headphones.


----------



## tdogzthmn

The 5998 has a very clean and detailed sound which is what I was looking for.  Mine is branded IBM and I scored it off ebay for $30.


----------



## zlobby

Just a heads up for those interested in buying one of these.  We are starting a group buy on this forum.  This thread has all the information...
   
http://www.head-fi.org/forum/thread/527004/bottlehead-crack-group-buy


----------



## Armaegis

I just installed the Speedball upgrade last night. Wow. For lack of a better word, the _resolution_ was amazing. The changes were subtle yet not; like little micro details were restored to the music. I'm not even talking about "things I've never heard before" trope... no, more in the sense that I could now hear how each note would sing just a little sweeter, and have just that touch of air and vibrato. For acoustic and vocals, this was simply magical. If you listen to music where the breath between notes is just as important as the music itself, then this is a highly recommended (if not mandatory) upgrade.
   
  That said, I couldn't hear much of a difference when playing some heavy and "crowded" music. In these cases, that sense of detail and intimacy was not so much lost as it was obscured. Nowhere to "breath" so to say.


----------



## james93

Quote: 





armaegis said:


> I just installed the Speedball upgrade last night. Wow. For lack of a better word, the _resolution_ was amazing. The changes were subtle yet not; like little micro details were restored to the music. I'm not even talking about "things I've never heard before" trope... no, more in the sense that I could now hear how each note would sing just a little sweeter, and have just that touch of air and vibrato. For acoustic and vocals, this was simply magical. If you listen to music where the breath between notes is just as important as the music itself, then this is a highly recommended (if not mandatory) upgrade.
> 
> That said, I couldn't hear much of a difference when playing some heavy and "crowded" music. In these cases, that sense of detail and intimacy was not so much lost as it was obscured. Nowhere to "breath" so to say.


 

 Which headphones are you using?
   
  I'm on the list for the group buy for the Crack with Speed and my current headphones are Grado SR-60, which I will still use for work.  I'm looking to upgrade to either the Grado HF-2, Senn HD-600 or 650.
   
  James


----------



## WyldRage

Quote: 





james93 said:


> Quote:
> 
> 
> 
> ...


 

 Get one of the Senns then: the Crack won't play well with Grados, since they are low impedance. But I must add that I prefer my HF-2 to my HD600, I simply never use the Crack for the former.


----------



## james93

Thanks WyldRage, I will start looking at the Senn for my next headphone.
   
  James
   
  BTW, which amp do you like with your HF-2?


----------



## WyldRage

Hagerman Castanet. It's a DIY, transformer-coupled SET. I used it for all my headphones, but it only barely has enough power for orthos.


----------



## Armaegis

The high end Senns are generally well regarded with the Crack, and my experiences are no different (though sadly I've never tried the 800, though I've tried the 580/600/650). Grados were ok, but didn't impress as well as the Senns (though an impedance cable made it better).
   
  My favourite headphones to pair with the Crack is my Sextett (MP). I've gone through a fair bit of gear this past year, buying and selling stuff all over the place looking for a certain sound, and this combo has stuck with me through it all. I've even got a 2nd pair of Sextetts (LP) I want to sell... *cough* 
	

	
	
		
		

		
			





 I was going to try and collect all three, but then reality and mortgage payments brought me back down to earth.


----------



## Beefy (May 18, 2021)

I finally got around to uploading some photos of my Crack......

 External:




 Upskirt, mostly stock:




 Plus Speedball and film output caps:




 Highlights:
 TKD 2CP2511 50kohm pot
 50kohm 1W PRP resistors in series with the pot for approx -6dB pre-attenuation
 Speedball with a couple of resistor upgrades
 Axon 91µF/250V film output coupling caps
 Cardas RCA jacks (rhodium plating is a BITCH to solder)
 Teflon tube sockets plus PCBs (Woo Audio branded)
 2.2µF Axon film bypass cap on the last electrolytic filter cap
 Better PSU filter resistors
 PRP resistors for bleeding DC offset
 Neutrik jack with chrome ferrule

 The wood was finished with Watco Danish Oil in cherry, while the top plate and transformer cover were finished with Krylon hammered metal finish. All the screws were replaced with stainless steel socket cap jobbies. It is currently running a JJ ECC802S and a Cetron branded 5998. With the HD650, it gives a _very_ different presentation to what I am used to from the AD900 or SR-Lambda, but it is definitely growing on me - particularly for anything with brass or woodwind. All in all a great intro to PTP and tubes!


----------



## Armaegis

Gorgeous work. Boy, I'm glad I never took pics of my internals; it looks like rubbish compared to you guys.


----------



## Armaegis

So I've got this crazy though of hooking up two cracks to run balanced headphones... bad idea?


----------



## Beefy

The gain would be pretty damn high......


----------



## HiGHFLYiN9

Quote: 





beefy said:


> I finally got around to taking proper photos of my Crack......


 
  Love it! Very nice work.


----------



## Beefy

Thanks, HF9. I took a lot of inspiration from your build, with just a sprinkle of my own personal flavour 
	

	
	
		
		

		
		
	


	



  
  Quote: 





highflyin9 said:


> Love it! Very nice work.


 


  Speedball went in today as well. No concrete listening impressions yet...... but it did decrease the B+ current draw from ~81mA to ~71mA. So everything runs a tad cooler now, which is pretty handy.


----------



## Armaegis

Quote: 





beefy said:


> The gain would be pretty damn high......


 


  You say that like it's a bad thiing.
   
   
  Quote: 





beefy said:


> Speedball went in today as well. No concrete listening impressions yet...... but it did decrease the B+ current draw from ~81mA to ~71mA. So everything runs a tad cooler now, which is pretty handy.


 
   
  I was quite impressed with the speedball in my system (I think I posted about it earlier). It gave it just a tad more resolution. Now I just need to get some quieter tubes.


----------



## SilverS

Hey I have a question about the Crack, I have one on backorder, but I've just picked up on how they don't work to well with Grado's Headphones. Is it worth the extra $250 to jump up to the S.E.X. or will I be ok with the Crack? Also note that I have a Quickie so I don't want to go to far out of my range here with a S.E.X. being fed by a Quickie.


----------



## Beefy

Well yes, it is. I've got pre-attenuation in my system, and still barely turn the volume knob to get things too loud with the HD650. With most balanced sources, the gain is doubled...... you would have no play on the volume knob at all.
  
  Quote: 





armaegis said:


> You say that like it's a bad thiing.


----------



## WyldRage

Quote: 





silvers said:


> Hey I have a question about the Crack, I have one on backorder, but I've just picked up on how they don't work to well with Grado's Headphones. Is it worth the extra $250 to jump up to the S.E.X. or will I be ok with the Crack? Also note that I have a Quickie so I don't want to go to far out of my range here with a S.E.X. being fed by a Quickie.


 


  I don't have a S.E.X., but I do own a Hagerman Castanet, another transformer-coupled SET. I must say that it should be well worth it to go from an OTL to a SET for a Grado. The much lower output impedance will greatly improve the quantity and control of the bass.


----------



## Armaegis

Really? I've run both the 580 and 600 off my Crack and would have the knob up to 2 or 3 o'clock before things were "too loud". Source is my iBasso D10 lineout or HotAudio DacDestroyer lineout.

  
  Quote: 





beefy said:


> Well yes, it is. I've got pre-attenuation in my system, and still barely turn the volume knob to get things too loud with the HD650. With most balanced sources, the gain is doubled...... you would have no play on the volume knob at all.
> 
> Quote:
> 
> ...


----------



## Beefy

Bloody hell. How loud do you listen?
  
  Quote: 





armaegis said:


> Really? I've run both the 580 and 600 off my Crack and would have the knob up to 2 or 3 o'clock before things were "too loud". Source is my iBasso D10 lineout or HotAudio DacDestroyer lineout.


----------



## Armaegis

Not that loud really. Comfortable listening is usually around 10 o'clock. Maybe the gain on mine isn't as high? *shrug* I've got one of the older kits that came with different tubes... but I don't know which ones since the markings are all rubbed off.


----------



## Beefy

And just one more pic of my Crack, with all the upgrades installed......


----------



## Henerenry

Yum, that looks fantastic Beef.
   
  What is the purpose of that bypass cap on the power supply?


----------



## Beefy

Bypassing electrolytic capacitors is fairly common to improve performance.
  
  Quote: 





henerenry said:


> Yum, that looks fantastic Beef.
> 
> What is the purpose of that bypass cap on the power supply?


----------



## ztsen

How does it sounds after all this upgrade?
  Quote: 





beefy said:


> And just one more pic of my Crack, with all the upgrades installed......


----------



## Beefy

It sounds very, very good with the HD650. Each upgrade made noticeable improvements on an already very nice amp.
  
  Quote: 





ztsen said:


> How does it sounds after all this upgrade?


----------



## tdogzthmn

Does anyone own both a S.E.X and a Crack?  It would be nice to hear how the two sound next to each other.


----------



## WyldRage

Quote: 





tdogzthmn said:


> Does anyone own both a S.E.X and a Crack?  It would be nice to hear how the two sound next to each other.


 


  Try asking at the Bottlehead forums.


----------



## zlobby

Just a heads up to those interested in buying a bottlehead crack.  We now have over 12 people, which means the group buy in on.  For anyone interested, the group buy will be open for one more week and then we will start collecting funds.  We also need a few more people to get on for the speedball discount, so if you already have a crack and just want a speedball, if we can get 12 for that, it will be a 15% discount as well.
   
http://www.head-fi.org/forum/thread/527004/bottlehead-crack-group-buy


----------



## thewolf1976

Wanted to post my completed Crack and setup. Listening to Alison Krauss "Forget about It" SACD with Yamaha YH-2's at the moment. Plenty of volume and sounds good! Got a pair of HD650's on the way too! Got that Raytheon power tube to try, plus a couple others in the bag.


----------



## KuKuBuKu

Could you modify this to have a balanced input/output?


----------



## Armaegis

You could do it if you built a second Crack and used one to control each channel (maybe get yourself a 4-way pot to simplify volume control).


----------



## KuKuBuKu

Can anyone give a general description of how this sounds?


----------



## tdogzthmn

^ It sounds good.  Or is that too general?


----------



## StephenPM

Curses on all of you! Just slipped a couple of benjamins to Doc for my Crack fix. If the wife catches me I'm ratting all of you guys out...


----------



## KuKuBuKu

Quote: 





tdogzthmn said:


> ^ It sounds good.  Or is that too general?


 

 Sorry, I meant if anyone could give me a description of sound signature


----------



## Bojamijams

Has anyone ordered a Crack and had the Bottlehead guys build it? I'm curious as to the quality of their work. Also, who here on the boards is willing to make them?


----------



## Todd R

I'll built it for you. 
PM me and we'll discuss....


----------



## KuKuBuKu

Quote: 





todd r said:


> I'll built it for you.
> PM me and we'll discuss....


 
  Price?
 While I would happily get someone else to build a Crack for me, I think Bottlehead charges a tad too much for laziness.


----------



## Armaegis

Quote: 





			
				Bojamijams said:
			
		

> /img/forum/go_quote.gif
> 
> Has anyone ordered a Crack and had the Bottlehead guys build it? I'm curious as to the quality of their work. Also, who here on the boards is willing to make them?


 


  
  Heck, I'd build one for cheap (and I'm in Canada too, so shipping would be way cheaper).


----------



## KuKuBuKu

Can anyone describe the sound signature? I might get one for my HD650s...maybe even buy another one to make a balanced amp...
   
  I am returning my Dayton DTA 100a. Don't buy it.


----------



## Armaegis

I would describe it as warm and mid focused, but I guess it also depends on your tubes and any mods you've done to it.


----------



## HiGHFLYiN9

Quote: 





bojamijams said:


> Has anyone ordered a Crack and had the Bottlehead guys build it? I'm curious as to the quality of their work. Also, who here on the boards is willing to make them?


 

 Building it is half the fun and educational to boot


----------



## KuKuBuKu

Quote: 





armaegis said:


> I would describe it as warm and mid focused, but I guess it also depends on your tubes and any mods you've done to it.


 
  Thanks!


----------



## Todd R

Quote: 





kukubuku said:


> Quote:
> 
> 
> 
> ...


 

 Price, what you want done to it, wood finish, paint, etc....


----------



## tdogzthmn

Quote: 





kukubuku said:


> Quote:
> 
> 
> 
> ...


 

 I have an HD600 which is close to the HD650.  IMO they match up very well.  The HD600 has a very realistic and natural sound coming from the crack.  Lots of fast and snappy bass with very clear highs.  Im sure you would be happy.  I had the speedball put in mine before I heard the stock version but I am sure its pretty close.  Running the 5998 tube the amp is dead silent, even with volume at the max.  My other 6AS7G's exhibit a slight hum but not enough to influence the sound when music is playing.


----------



## KuKuBuKu

Sounds good. Now to return this blasted Dayton...


----------



## vuntruong

WOW,  After reading all the post .  I really want one.  I dont need one, but no one really needs crack.  I just wish Doc would release the Dac that they are working on.  I hope there is an option to have the DAC + Crack+Crack for ballanced headphones goodness.  New school digital tech feeding Oldschool tubes, all enclosed in a homemade half wood, half silver Alu metal case.  Oh yeah, 60s, 70s, and 2010s in a box.


----------



## tdogzthmn

Quote: 





vuntruong said:


> WOW,  After reading all the post .  I really want one.  I dont need one, but no one really needs crack.  I just wish Doc would release the Dac that they are working on.  I hope there is an option to have the DAC + Crack+Crack for ballanced headphones goodness.  New school digital tech feeding Oldschool tubes, all enclosed in a homemade half wood, half silver Alu metal case.  Oh yeah, 60s, 70s, and 2010s in a box.


 


  I tried talking the Doc into bringing one to the upcoming bayarea meet, but unfortunately he did not believe it would be ready enough to show just yet!  I am trying to be patient too, and I know that good things come to those who wait!


----------



## vuntruong

Yeah, I stop buying any gears until I see or hear how this Bottlehead DAC thing turn out.   When it get release, I guess it would be time to hit rewind, and rebuild my stereo system around the DAC.  It is just so hard to switch to Tube audio.  U have to get new speakers because tube amp cant drive ineffecient speakers, then u gotta get the amp, and then the right Preamp.... AAHHHH.  Who have time for all that.  Just get a Tube DAC.


----------



## Doc B.

> I tried talking the Doc into bringing one to the upcoming bayarea meet, but unfortunately he did not believe it would be ready enough to show just yet!  I am trying to be patient too, and I know that good things come to those who wait!


 

 We had a lot going on in the past year with the construction and moving in to a new office, some important kits to get out (Crack, Speedball, Stereomour and the soft start upgrade for Paramount), and a higher commitment to doing shows in the name of my second job - Tape Project  (CES 2010 and 2011, a demo in Chicago, RMAF2010, and two, no, three Head Fi events). Something had to give for a bit and I decided the DAC was the best bet partly because it seemed that server software was still maturing. Things have eased up a bit now that we are 85% moved in and the above kits are in production. So we should have a pretty good block of time to work on the DAC, assuming that all involved in the project have time available to put in. And maybe there will even be some time to keep working on our experimental headphone...


----------



## Armaegis

Quote: 





doc b. said:


> And maybe there will even be some time to keep working on our experimental headphone...


 

  
  Wait... what?!? You can't tease us like that man!


----------



## skeptic

Quote: 





armaegis said:


> Quote:
> 
> 
> 
> ...


 

 He's not teasing.  Check out the thread on the Bottlehead forum: http://www.bottlehead.com/smf/index.php/topic,1145.0.html  I can't wait to hear more about this potential project!


----------



## grokit

Perhaps call it the Bottlehead Cranium? Sounds great...


----------



## tdogzthmn

Who else really likes this amp with their HD600?  I certainly do.


----------



## maverickronin

Its great with my HD650s.  I'm using a RCA 6AS7G and Sylvania 5814A Goldbrand right now.


----------



## Armaegis

Has anyone ever compared the Crack vs the Ear+ series?


----------



## tdogzthmn

Got more music to feed my addiction.


----------



## dirkpitt45

Tdogzthmn how did the crack compare to the minimax with the hd600s(if you remember)? I'm debating between the two I think. Only have a starving student right now, and it's got way more than enough power for the hd600s so I'm not sure if the crack would be less than optimal for the 600s since they're low impendance.


----------



## Beefy

Quote: 





dirkpitt45 said:


> so I'm not sure if the crack would be less than optimal for the 600s since they're low impendance.


 

  
  ..... eh? The HD600 are 300 ohm - ideal for the Crack


----------



## dirkpitt45

I thought it was the 650 that was 300ohm, the 600's were lower? I'm probably wrong though


----------



## maverickronin

They have the same nominal impedance, but the HD650s have a nastier curve.


----------



## Armaegis

Finished building a S.E.X. amp the other day. Haven't really given it a full run down yet, but both the Crack+Speedball and S.E.X.+C4S have a warm mid-centric sound with wide staging. Paired with my Sextetts, I would say the Crack sounds better... it just has this deeper feel to it that's hard to qualify. The S.E.X. sounds great with my Phiatons though. Probably the first time I really enjoyed listening to the PS 500, which is normally a little thin in the mids for my tastes (compare to the MS400 which are thick like gravy).

  
  Quote: 





maverickronin said:


> They have the same nominal impedance, but the HD650s have a nastier curve.


 


  Eh? The 600 actually looks worse than the 650...


----------



## maverickronin

Quote:


armaegis said:


> Eh? The 600 actually looks worse than the 650...


 


  Whoops!  You're right.  That's what I get for pasting in pictures without triple checking them...


----------



## HiGHFLYiN9

Quote: 





armaegis said:


> Finished building a S.E.X. amp the other day. Haven't really given it a full run down yet, but both the Crack+Speedball and S.E.X.+C4S have a warm mid-centric sound with wide staging. Paired with my Sextetts, I would say the Crack sounds better... it just has this deeper feel to it that's hard to qualify. The S.E.X. sounds great with my Phiatons though. Probably the first time I really enjoyed listening to the PS 500, which is normally a little thin in the mids for my tastes (compare to the MS400 which are thick like gravy).


 
   
  Congrats on finishing it up. I've only started mine, still waiting for the paint to harden on the Magnequest Xformers


----------



## Armaegis

I marathoned the build in one day (heh... sex all day...) which was probably not the smartest thing to do. I didn't bother with painting or prepping the plate. It was the first free evening I've had in a while so I was intent on getting it all done.
   
  One thing I don't like about the build (applies to the Crack as well) is the placement of the caps with the stubby little leads. I've only got a cheap soldering iron from radio shack. A nicer one with skinny tip or angled tip would have been much better for soldering in those hard to reach places.
   
  I've got a hankering to build another Crack, but don't really want to toss out the cash for another one. I'm hoping someone will take me up on my ad in the forums to trade a kit for my completed one


----------



## HiGHFLYiN9

Quote: 





armaegis said:


> I marathoned the build in one day (heh... sex all day...) which was probably not the smartest thing to do. I didn't bother with painting or prepping the plate. It was the first free evening I've had in a while so I was intent on getting it all done.


 

 Lol, we have very different building philosophies. I try to draw out builds as long as possible. Reason being is that if I finish too quickly; I'll feel obligated to buy something else to put together  I also tend to get bored if I spend too much time in front of the soldering iron. Thankfully I have a very busy powdercoater; he can add a month or two to a build while I'm waiting for him to take care of something.
   
  In regards to the caps, you could easily mount them with some squares and zip ties in the middle of the chassis, then run wire to the terminals. Wouldn't look as clean though.
   
  You should *definitely* experiment with the coupling capacitors if you aren't satisfied with the sound. Try some Obbligatos or Russian PIOs for a cheap tweak.


----------



## Armaegis

I normally would have spread it out over a few days, but sometimes I get into a good rhythm and simply lose track of time. Also, with my schedule the way it is, the next opportunity might not come along in a while.
   
  I tried bypassing the 120 ohm resistors with some simple clip leads. It sounded a little better, but volume also went up so I won't discount the placebo effect. The background hum becomes a little more prominent though. With the resistors in you can barely notice them (or not at all), but without the resistors and with sensitive headphones you can notice. It disappears when you have music playing though. I was thinking of maybe trying a shunt volume pot config with the output resistors bypassed.


----------



## tdogzthmn

I'm really sad my 5998 went out on me yesterday.  Going back to the 6AS7G just isn't cutting it.  Does anyone else notice a big difference between this tube and their others or am I crazy?


----------



## Skylab

The 5998 and 6AS7G are quite different tubes, so you should notice a big difference


----------



## KuKuBuKu

Quote: 





skylab said:


> The 5998 and 6AS7G are quite different tubes, so you should notice a big difference


 
  Hoping you get to hear the Crack sometimes, would love to hear your opinion.


----------



## Bones13

Finally found the circuit fault keeping the right channel from working this weekend.  My Crack/Speedball is now alive and burning in in my home system. Sounds wonderful with my HD650s.
   
  Not too hard to build (my first audio project) and was fun to work the wood frame, I do have a woodshop.  My main workbench is covered with wire strippings and tail cut offs.
   
  I did put in teflon sockets with PCBs, and upgraded the caps and attenuator.  Very detailed, and not mushy at all.


----------



## skeptic

What caps and attenuator did you end up going with?  I've been contemplating picking up some film output caps but am having trouble deciding between Axons ($16), Daytons ($22), or Obbligatos ($40).  All have been mentioned on the bottlehead forums but there's been little comparison between the three at least in so far as I've been able to find.  A further question on this topic, if I am going to upgrade the caps, will it be any harder for me to do this after my speedball is installed?  Should I be planning to do it first?
   
  My build is chugging along and has been quite enjoyable - with one exception.  Maybe I have particularly clumsy fingers, but attaching the 2 LED's to the 9-pin socket was kind of a struggle for me.  I got it done eventually, but working with those tiny leads was tough.  I probably need to invest in some appropriate tweezers.  Needle nose pliers were way too big to be of much assistance with the LED's.


----------



## KuKuBuKu

Quote: 





bones13 said:


> Finally found the circuit fault keeping the right channel from working this weekend.  My Crack/Speedball is now alive and burning in in my home system. *Sounds with my HD650s.*
> 
> Not too hard to build (my first audio project) and was fun to work the wood frame, I do have a woodshop.  My main workbench is covered with wire strippings and tail cut offs.
> 
> I did put in teflon sockets with PCBs, and upgraded the caps and attenuator.  Very detailed, and not mushy at all.


 
  what?


----------



## Bones13

Quote: 





skeptic said:


> What caps and attenuator did you end up going with?


 
  I got the Axons (91 uF) from partsconnexion and I got the goldpoint attenuator off of their site, with one of their knobs.
  
   


  Quote: 





kukubuku said:


> Quote:
> 
> what?


 
  edited, thanks.


----------



## Beefy

The 91µF Axon caps and TKD 2CP2511 pot from Partsconnexion are hard to beat for value-for-money.
   
  With respect to installing caps, you will have to install fly leads of some sort and something to mount them with. Of builds detailed on Head-Fi, check Highflying9 and my build for ideas and pics. Do this first, then I would recommend installing the Speedball next. You will find it hard to get access to the terminal strips one the bigger caps are in there. Big caps go in last.
  
  Quote: 





skeptic said:


> What caps and attenuator did you end up going with?  I've been contemplating picking up some film output caps but am having trouble deciding between Axons ($16), Daytons ($22), or Obbligatos ($40).  All have been mentioned on the bottlehead forums but there's been little comparison between the three at least in so far as I've been able to find.  A further question on this topic, if I am going to upgrade the caps, will it be any harder for me to do this after my speedball is installed?  Should I be planning to do it first?


----------



## bcg27

Quote: 





skeptic said:


> What caps and attenuator did you end up going with?  I've been contemplating picking up some film output caps but am having trouble deciding between Axons ($16), Daytons ($22), or Obbligatos ($40).  All have been mentioned on the bottlehead forums but there's been little comparison between the three at least in so far as I've been able to find.  A further question on this topic, if I am going to upgrade the caps, will it be any harder for me to do this after my speedball is installed?  Should I be planning to do it first?
> 
> My build is chugging along and has been quite enjoyable - with one exception.  Maybe I have particularly clumsy fingers, but attaching the 2 LED's to the 9-pin socket was kind of struggle for me.  I got it done eventually, but working with those tiny leads was tough.  I probably need to invest in some appropriate tweezers.  Needle nose pliers were way to big to be of much assistance with the LED's.


 
   
  The LEDs were a little difficult for me as well. I think a combination of a bunch of stuff in the way plus the leads were really thin made it hard. A good pair of tweezers can be very helpful in places where pliers are too big though.


----------



## skeptic

Thanks very much for the info and advice Beefy, Bones, and bcg!  
   
  It makes perfect sense now that you've spelled it all out for me, but as a complete novice builder, it simply hadn't dawned on me to hook up fly leads before installing the speedball.  Thanks again for the explanation and for sharing your photos Beefy (beautiful build by the way!).  This was tremendously helpful!


----------



## Armaegis

Quote: 





bcg27 said:


> The LEDs were a little difficult for me as well. I think a combination of a bunch of stuff in the way plus the leads were really thin made it hard. A good pair of tweezers can be very helpful in places where pliers are too big though.


 

 Sometimes I use chopsticks to handle the small components...


----------



## maverickronin

Do you remember to clean the lead off before eating with them or do you just have a spare set in you toolbox?


----------



## Armaegis

I'm Asian... I have a spare set of chopsticks in practically every drawer and toolbox in the house


----------



## james93

tag
   
  James


----------



## Skylab

Oh-oh...lookie what I bought...custom build Crack Bottlehead w/Speedball...


----------



## Armaegis

Wow... that is gorgeous. Who buiild that?


----------



## Skylab

Ordered here:
   
  http://www.soundingenuity.com/custom_vacuum_tube_headphone_amp.htm
   
  They did a custom wood color for me, to match my other stuff.  Really nice job.
   
  I've been impressed with the Speedballed Crack so far - nice sounding amp!


----------



## Armaegis

Come to think of it, I've seen that posted here before.
   
  The Crack+Speedball is definitely one of my favourite amps.


----------



## Skylab

Yeah I posted the link before - I finally went ahead and bought one 
	

	
	
		
		

		
		
	


	




  I'm impressed, with the 600 ohm Beyers it is really nice.


----------



## Armaegis

Yeah, I'm not even a fan of Beyers but I thought they were nice out of the Crack.. still not enough to make me buy a Beyer though


----------



## pigmode

Quote: 





skylab said:


> Yeah I posted the link before - I finally went ahead and bought one
> 
> 
> 
> ...


 
   

  
  I know its basically an inexpensive amp, but any thoughts on its power, dynamics, and resolution? This could be a fun tide-me-over till I get the amp I really want later this year.


----------



## Skylab

Like many triode based OTL amps, I think it's very good in this regard _*with high impedance headphones*_.  With low impedance headphones, not so much.


----------



## maverickronin

Quote: 





skylab said:


> Like many triode based OTL amps, I think it's very good in this regard _*with high impedance headphones*_.  With low impedance headphones, not so much.


 
  It great with my HD650s but pretty awful with my modded T50RPs.  Even with the transformer box I built from nikongod's schematic earlier in the thread. I was thinking about the Bottlehead SEX, but the Lyr is cheaper, stronger, and I won't have to spend a weekend trying to do tricky soldering.  I'm too ham-fisted to do anything more cramped than a cable or IC without a lot of trial and error.
   
  Decisions, decisions...


----------



## pigmode

^ This would be for my HD600 but I am going to have to think this through as well. I have all the tools, but my last diy experience still hovers like a dark cloud. That being a Buschorn Mark II project, with all of the cut pieces of baltic birch ply laying around for a year before getting thrown out.
   
  PS  thats a classy looking custom Crack.


----------



## Skylab

LOL!  Yeah that's why I had someone build one for me


----------



## Armaegis

Quote: 





maverickronin said:


> It great with my HD650s but pretty awful with my modded T50RPs.  Even with the transformer box I built from nikongod's schematic earlier in the thread. I was thinking about the Bottlehead SEX, but the Lyr is cheaper, stronger, and I won't have to spend a weekend trying to do tricky soldering.  I'm too ham-fisted to do anything more cramped than a cable or IC without a lot of trial and error.
> 
> Decisions, decisions...


 

 My experience with trying to run orthos off a Crack have been less than stellar (T50rp, T40v1, YH1, YH3), but orthos are generally power hungry beasts anyways.
   


  Quote: 





pigmode said:


> ^ This would be for my HD600 but I am going to have to think this through as well. I have all the tools, but my last diy experience still hovers like a dark cloud. That being a Buschorn Mark II project, with all of the cut pieces of baltic birch ply laying around for a year before getting thrown out.
> 
> PS  thats a classy looking custom Crack.


 
   
  Quote: 





skylab said:


> LOL!  Yeah that's why I had someone build one for me


 

 With the exception of a couple tricky capacitor placements, I found the crack quite easy to build. The manual is very clear with step-by-step pictures and the whole build can be done in a weekend.


----------



## bcg27

That's pretty cool that it holds your headphones. Not an entirely unreasonable price either, considering the custom case. The speedball construction is the same price bottlehead charges to make it for you. It definitely looks better than the one I built 
	

	
	
		
		

		
			




   
  For those wary of building it yourself it really is an easy build with excellent step by step instructions including pics. Took me 3 hours, not including the gluing and staining the case. It sounds really nice with hd600s


----------



## Bones13

I did the Crack/Speedball build as a first DIY project (other than a few cables).  I cut some corners, and upgraded some parts before I started construction. (stepped attenuator/caps/tube sockets with PCB adapters)  I have a woodshop, so the glue-up and finishing of the case and main board were not difficult.  I was very excited to have mine work right out of the gate, well on one side.  After re-flowing and inspecting all the joints, I got the other side working too.  Very nice amp with HD650s.  On the smooth side, but then thats what tubes are for.


----------



## BmWr75

Quote: 





skylab said:


> Ordered here:
> 
> http://www.soundingenuity.com/custom_vacuum_tube_headphone_amp.htm
> 
> ...


 
   
   
  Skylab,
   
  What tubes are you running?  I see the GEC logo on the power tube.  Didn't know GEC made a 6AS7.
   
  BMWR75


----------



## alvin sawdust

That would be the GEC 6AS7G / A1834. A really great tube, I use two of them on my Darkvoice 337se.
  Quote: 





bmwr75 said:


> Skylab,
> 
> What tubes are you running?  I see the GEC logo on the power tube.  Didn't know GEC made a 6AS7.
> 
> BMWR75


----------



## Skylab

Yip, IMHO, the very best 6AS7 you can get...if you can find one. Very hard to come by. Pity, since they are terrific.


----------



## SDMAN

I found a guy overseas with a for sale listing 'claiming' he has 49 NOS GEC A1834's. Its not an english website, and google translator isnt very good. But I have just contacted someone who can read the site, and is making contact with them. Requires an acct so you can log on to ask questions or make a purchase. We will see if this pans out.


----------



## Skylab

Wow - please post what you learn!


----------



## alvin sawdust

Consider my interest piqued!
  Quote: 





sdman said:


> I found a guy overseas with a for sale listing 'claiming' he has 49 NOS GEC A1834's. Its not an english website, and google translator isnt very good. But I have just contacted someone who can read the site, and is making contact with them. Requires an acct so you can log on to ask questions or make a purchase. We will see if this pans out.


----------



## james93

Quote: 





alvin sawdust said:


> Consider my interest piqued!


 


 Same here...
   
  James


----------



## zlobby

Finally started working on my crack from the group buy.  While I havent gotten to any electrical components, I have the base stained and the chassis plate painted.  I still need to let the chassis paint harden up a bit before I dive into the amp itself.  Really happy with how the hammered finish turned out.  But I personally think its looking pretty good so far


----------



## james93

WOW Zlobby, its looking good.  What color stain did you use?  It goes real good with the hammer tone.
   
  I still haven't started mine from the group buy.  I'm still trying to decide what color stain and what color to paint the top.  I'm thinking about painting it a solid color as apposed of doing the hammered tone.
   
  James


----------



## zlobby

Thanks james. I used minwax "golden oak".  It came out a little darker than I was expecting, but i'm happy with the results.  I will probably finish it with a satin poly.  For anyone interested, I used Rustoleum Universal Hammertone spray paint in brown.  This stuff really benefits from sanding in between coats as well as laying several down.  I think I have 4 total.


----------



## KuKuBuKu

Quote: 





skylab said:


> Oh-oh...lookie what I bought...custom build Crack Bottlehead w/Speedball...


 

 Put it in your amp ranking please


----------



## Skylab

I will as soon as I feel I have the full measure of it


----------



## zlobby

I "finished" building my crack today, but when i went to do the resistance check, I am getting bad readings at terminal 14 and 20.  They are both reading 5.3k, when they should be reading zero... Any ideas?  Will post this on the bottlehead forum, but i need to wait to be approved first.


----------



## tdogzthmn

I recently got a Valvo E80 CC to try out with my amp.  I was not quite sure what to excpet from it other than more gain but after listening to it a bit I found it very forward and ritch in the mids.  I am running it with a 5998 which has been my favorite power tube so far.


----------



## skeptic

Quote: 





beefy said:


> The 91µF Axon caps and TKD 2CP2511 pot from Partsconnexion are hard to beat for value-for-money.
> 
> With respect to installing caps, you will have to install fly leads of some sort and something to mount them with. Of builds detailed on Head-Fi, check Highflying9 and my build for ideas and pics. Do this first, then I would recommend installing the Speedball next. You will find it hard to get access to the terminal strips one the bigger caps are in there. Big caps go in last.


 

 I had to set my build aside for a few weeks after tweaking my back (and then getting buried at work), but I'm looking to get back at it this coming weekend.  I was hoping I might obtain a little bit of additional advice concerning installation of the zip tie mounts you used for the eventual mounting of your film caps, among other things.
   
  It looks like you drilled your case 4 times on each side to put these in?  I've never drilled metal before, and I'm a bit nervous about how to take it on given that my kit is already 3/4 assembled.  Do you think this is still manageable?  If so, a few additional questions:
  (1) I assume I should be using the caps (once they arrive) to measure the exact placement of the zip time mounts (to avoid fit issues)?
  (2) Do you recall the size of the screws and drill bit you used for the mounts and are there particular zip tie mounts you like?
  (3) Can you recommend some internal wire for me to pick up from partsconnexion for purposes of the fly leads?
  (4) I saw your reference to installing a resister in series with the stepped attenuator you recommended.  Any chance you can give me a link for the part you used and elaborate about exactly how it get soldered into the circuit?
   
  Thanks again for any and all help you are able to provide!


----------



## Bones13

I put those caps in my amp.  I used wiring left over from the construction for the fly leads, and left them long enough to allow enough motion to be able to check connections etc in that area.
   
  I mounted mine in a simple manner, I put the caps in the approximate location on the underside, and found the center point.  I then drilled one hole on either side (one per cap) .  Drilling the aluminum plate is not difficult, just don't press too hard, and be careful as you go through the far side of the plate.  It's best to have the plate supported on some wood that you can drill into.  This minimizes the burring that will occur on the other side.
   
  I put a screw from the top, then used some velcro strapping (hooks on one side, and loops on the other), and made a hole in the strap, and pushed the strap onto the bolt, then put the washer and nylon locking nut on, and tightened up.  Wrap the velcro around the cap, and extra wiring, and _voila_, your done.  My method allows the caps to shift a bit as you put the plate back in the wooden case, but does not allow them to fall down.  I have not heard any vibration or other sound to indicate that the loose holding system is an SQ liability.


----------



## Beefy

Quote: 





skeptic said:


> I had to set my build aside for a few weeks after tweaking my back (and then getting buried at work), but I'm looking to get back at it this coming weekend.  I was hoping I might obtain a little bit of additional advice concerning installation of the zip tie mounts you used for the eventual mounting of your film caps, among other things.
> 
> It looks like you drilled your case 4 times on each side to put these in?  I've never drilled metal before, and I'm a bit nervous about how to take it on given that my kit is already 3/4 assembled.  Do you think this is still manageable?  If so, a few additional questions:
> (1) I assume I should be using the caps (once they arrive) to measure the exact placement of the zip time mounts (to avoid fit issues)?
> ...


 

 Yes, I drilled four holes on each side to attach the cable tie mounts. It should be manageable if you are careful, because the aluminium is very soft. Just make sure you give it a decent whack with a centre punch to ensure you don't skate the drill bit all over the place. It might pay to cover as much of the top plate as you can to prevent scratching.
   
  1) Yes, very good idea.
  2) 4-40 1/4 inch screws and nuts, 3mm drill bit, zip tie mounts were from Home Depot (unsure of brand).
  3) I don't believe in using 'boutique' wire; I used the wire in the Crack kit.
  4) I used part # PRP-163-70176 from Partsconnexion. PRP-162-50205 would probably be better, as it is physically smaller. It is used in-series with a 50k pot to give the pre-attenuation... so on page 21 of the manual, second image, where it shows connecting the red and white wires to the pot from the inputs, you would solder in the resistor instead, and connect the input wires to the other end of the resistor. If you use the TKD pot I linked, all of the wire connections are in the same physical location. Of course, you could just use a 100k TKD pot, which even without the pre-attenuation would still be much better than the stock pot.


----------



## zlobby

Finally finished.  It wasn't without a hitch, as I ran into a couple small problems, but the people on the bottlehead forum were helpful.


----------



## pigmode

^ Impressive. For the meantime I decided to go with another (assembled) amp, but will probably get one of these in the future.


----------



## Armaegis

They're also developing another headphone amp called Smack... and a Dac... and their own headphones... argh I don't have enough money to spend!


----------



## milosz

Hwy, Zlobby-  what did you use to finish your wood base?  I've done two Bottlehead wood bases now and they look nice but I didn't get that nice "Tiger's Eye" effect in the figuring that you got.  
   
  I've done the wood finishing and am now working on the electronics for an Eros phono preamp;  and not to be rude but let me show you my Crack...
   
  You can see the wood on mine has nice grain but nothing like that "depth" you got on yours.  I used Minwax stain followed by 5 coats of Minwax Wipe-On Poly with lots of sanding / 0000 steel wool in between.


----------



## zlobby

Honestly I think it is more a result of the wood itself than the finish.  But for the finish, I used minwax golden oak stain (came out much darker than expected, but im not complaining).  Then minwax wipe on poly in satin.  I probably put on about 6 coats over the course of 2 days, lightly sanding with 0000 steel wool on every coat but the last.  I really wanted to do tung oil, but it was more expensive.


----------



## milosz

Interesting, we both used near-identical Minwax products.  I guess maybe your panels just had nicer figuring in them.
   
  The alder wood seems to vary quite a bit.  The pieces I got for my Eros phono pre came out quite a different color than the Crack with the same stain/same technique.


----------



## skeptic

Beefy and Bones - Thank you again so much for your detailed explanations and invaluable advice on the cap and pot upgrades!  I truly appreciate your willingness to take the time to guide me along.
  I'm now eagerly awaiting the arrival of my axons and TKD (100k) pot


----------



## skeptic

So I finished my basic build and finally got around to running all the measurements last night.  The good news is that: (1) my tubes produce a lovely glow; (2) nothing started smoking; (3) my led's light up; and, most importantly, (4) all of my resistance and voltage measurements are as they should be per the instructions. 
   
  That said: I'm not getting any sound at all out of my headphones.  Talk about buzz-kill.  I'm guessing this means my issue is somewhere in the signal path, but I'd welcome and greatly appreciate any advice you guys may have on tracking it down.  (For the record, I was swapping the same RCA input cable back and forth between my crack and my woo3, so I know that's not the issue.)
   
  Would it be feasible for me to simply start at the RCA jacks, clip my black lead to ground, and then follow the signal path through the amp watching for fluctuating voltages so as to confirm that music is in fact passing through each node on the way to the 1/4" output?  Thanks in advance for your guidance!
   
  Also, if it helps, here is the low res photo I had time to grab on my way out the door to work this morning.  The only current deviation from a stock build (that I intended) is the fly leads I used in contemplation of upgraded output caps.


----------



## Doc B.

Hmm, what we can see in the photo looks OK. Best bet is to take this to the Bottlehead forum for help troubleshooting. That said, your idea of tracing an injected signal is a good one. Look for it at terminals 6 and 10. If it is there, inspect the headphone jack. If there is no signal at 6 and 10 check to see if there is any signal at the outboard pair of terminals on the volume pot (signal will be much smaller there). If there is no signal there inspect your RCA jacks for shorts.


----------



## skeptic

Thank you very much for the quick response Doc!  Two questions:

 How high, if at all, would you recommend that I set the volume when measuring at terminals 6 & 10 and/or at the outboard terminals on the pot? 
 What setting/sensitivity would you suggest I use for measuring the injected signal?  My meter is a craftsman model no. 82140 (owner's manual visible at: http://c.kenmore.com/assets/own/03482146e.pdf )
   
  I'll give those 4 sets of measurements a go, hopefully tonight (time, wife and child permitting) and will report back.  I have a pending account registration over on the Bottlehead forum, and I will transplant this discussion over there as soon as my admin approval comes through.  Thanks again!


----------



## skeptic

Thank you very much for the quick response Doc!  Two questions:

 How high, if at all, would you recommend that I set the volume when measuring at terminals 6 & 10 and/or at the outboard terminals on the pot? 
 What setting/sensitivity would you suggest I use for measuring the injected signal?  My meter is a craftsman model no. 82140 (owner's manual visible at: http://c.kenmore.com/assets/own/03482146e.pdf )
   
  I'll give those 4 sets of measurements a go, hopefully tonight (time, wife and child permitting) and will report back.  I have a pending account registration over on the Bottlehead forum, and I will transplant this discussion over there as soon as my admin approval comes through.  Thanks again!
   
  -----
   
  Edit to report back:
   
  All four nodes revealed small fluctuating voltages (which were amplified at terminals 6, 10, and the headphone jack), demonstrating the transmission of at least some audio signal, but _initially_, when I flipped it back over and fired it back up, I still had no sound other than a very soft buzz.
   
  Further scrutiny revealed the need to clip a stray lead from the resistor at terminal 13L (forgotten/concealed beneath the filter cap) - that may or may not have been touching the chassis plate.  Harboring some hope that this was it, I checked all the resistances and voltages again, and plugged in my phones.  Still no dice other than the aforementioned soft buzz.  Then, unthinking, I gently tapped my finger on the top of the plate to the right of the power tube.  The sound of microphonics instantly interrupted and cut-off the buzz - and glorious audio faded in, reaching full volume in about 1 second's time.  A few minutes later, it faded back out, to be replaced by buzz.  One more very gentle tap restored the sound and the pitch-black noise floor - which has yet to cut out again.
   
  Clearly I've still got something loose on the inside (a cold joint, a short - or maybe an issue with the power tube?), but I'm simply elated to finally hear this amp sing.  In fact, I sat flipping lossless tracks (with a giant stupid grin on my face) until about 1 a.m. last night.  This amp, even in stock form, is undeniably a keeper 
	

	
	
		
		

		
		
	


	



   
  In any event, if any of my long-winded description happens to spark any insights as to what might be causing my audio to fade in or out, replaced by a very soft buzz (and reparable by a light tap or two), I'd be most grateful for your further guidance.  Thanks again!


----------



## Doc B.

If tapping makes it work you should go over the connections with a magnifier, as it is a 90% likelihood that a solder joint was missed and the wire is making intermittent contact when you tap on the chassis plate. The other 10% chance is that there is an intermittent in a tube.


----------



## skeptic

Quote: 





doc b. said:


> If tapping makes it work you should go over the connections with a magnifier, as it is a 90% likelihood that a solder joint was missed and the wire is making intermittent contact when you tap on the chassis plate. The other 10% chance is that there is an intermittent in a tube.


 

 Thanks for the further guidance Doc!  I never clearly identified which contact was loose, but retouching all the solder joints on the 8 pin socket did the trick.  I dropped in a tkd pot while I was at it, and my Crack is now working reliably and sounding better than ever.  Hats off to you and your crew at Bottlehead for creating this marvelous project amp  - and all the more so for managing to make the build and directions so beginner friendly, supplemented by trouble-shooting support.
   
	

	
	
		
		

		
			




   
  As it turns out, I'm not the only one in the family with a high regard for the Crack.  I put my 'phones on my 14 month old for kicks.  Little did I know she would love it, start dancing, and then burst into tears when I eventually tried to my headphones back.  At this rate, I just may have to pick up a second kit.  Thanks again!


----------



## Doc B.

So you're saying that I'm responsible for a Crack baby?


----------



## tdogzthmn

^ it's never too early to start forming good habits. 

 I spent more time today with the E80CC and found it to be noticeably clearer then my other 12au7s and should have a long life. The only down side it the the extra gain does not work well for my lower 120 ohm K400s which distort quicker than they did with the less powerful tubes. The HD600 sound crystal clear and have lots of slam and detail, quite addicting.


----------



## fishski13

welcome to DIY Skeptic.  the real addiction has just started.  btw, what a beautiful daughter you have.  my 3.5 yr old girl loves listening to my HPs and she did even at your daughter's age, but there's no way i would let my 15 mo. old boy touch 'em - being boy, they'd be trashed in under a minute.


----------



## skeptic

Quote: 





doc b. said:


> So you're saying that I'm responsible for a Crack baby


 
   
  Only indirectly.  You may traffic the "Crack," but your end users are the local pushers 
	

	
	
		
		

		
		
	


	




  
  Quote: 





fishski13 said:


> welcome to DIY Skeptic.  the real addiction has just started.  btw, what a beautiful daughter you have.  my 3.5 yr old girl loves listening to my HPs and she did even at your daughter's age, but there's no way i would let my 15 mo. old boy touch 'em - being boy, they'd be trashed in under a minute.


 
   
  Thanks fishski!  My daughter is actually something of a thrower (remotes, my ps3 controller, books, you name it, regularly take flight in her vicinity these days) - so I kept a pretty close eye on her during her "audition."  But if anything, she was actively working to keep the phones on her head.  It really was awesome to get to share my audio fascination with her even at this early age, particularly via the kit I had just completed.  It must be all the more rewarding at 3.5 years of age!
   
  You're totally right about DIY being the real addiction.  In addition to completing my Crack upgrades, I've already got a mini^3 kit lined up as my next project.  Pending its upcoming release, the bottlehead dac also sounds like an asboslute "must build."  Lots to look forward to in this hobby for sure!


----------



## Feynman

Okay, I ordered the crack amp a couple of weeks ago and still awaiting the shipping of the amp but in the meantime I'm looking for a good soldering iron as this is the first diy project I'm doing. 
  I'm quite confused over what to get but it seems that it's worth shelling out some more money for a good soldering station, is this one up to the task?
   
  https://www.elfa.se/elfa3~se_sv/elfa/init.do?item=82-302-03&toc=19658
   
  It is a Weller WHS 40!


----------



## dirkpitt45

I picked up a Weller over Christmas for my first project, don't remember the model name off the top of my head. It worked great though, nice and light "wand" and the cord was nice and flexible. 
   
  Just finished up my crack build, the soldering parts at least. I've got it sitting in a cardboard box for testing haha. Waiting for the base to finish drying so I can glue it together. I'll post some pictures once its all finished. 
   
  How hot are everyone's crack builds getting? After about an hour the metal plate gets hot, can't leave my hand on it for more than 30-40 seconds or so before its uncomfortable.


----------



## Doc B.

Quote: 





dirkpitt45 said:


> How hot are everyone's crack builds getting? After about an hour the metal plate gets hot, can't leave my hand on it for more than 30-40 seconds or so before its uncomfortable.


 


  Sound like it's working fine, that's what it's supposed to do.


----------



## jbeard

Skylab,
   
  I noticed you had your T-1's on the crack.
   
  I just received my pair of T-1's and am very serious debating which amp I should get for her.
   
  I am considering Crack very serious and wondered about your impressions of this pairing.


----------



## Armaegis

I thought the Crack paired very well the DT770/880/990. Can't say about the T1 though...


----------



## Skylab

The T1 and the Crack are excellent together. Definitely a good pairing.


----------



## jbeard

Thanks for the replies.
   
  I am definitely leaning toward the Crack.  Sounds like it has a killer bang for the buck value just like its namesake.
   
  I am curious if anyone has compared the Crack with the Little Dot MKIII or the Decware CSP using the Beyer T-1's?


----------



## Tinola

Bought the crack yesterday! Looking forward to building it!

Anyone think upgrading the caps worth it?
I am going to get an AXON 91uf maybe.
Also, does black gate caps really make a difference? I was thinking of replacing the other caps to black gates to improve the sound.
I'm also gonna roll tubes with these. I already have 3 different 12au7's in my collection, but am going to buy more..
Will look for 5998's. Really hard to find Tung Sol branded ones.

Ahh! The addiction!


----------



## Armaegis

Quote: 





jbeard said:


> Thanks for the replies.
> 
> I am definitely leaning toward the Crack.  Sounds like it has a killer bang for the buck value just like its namesake.
> 
> I am curious if anyone has compared the Crack with the Little Dot MKIII or the Decware CSP using the Beyer T-1's?


 

 I compared the Crack vs LDmk3 a couple months ago with an AKG K240 Sextett (MP) and DT880/600. To my ears, the Crack had better staging/separation and had a warmer tone.


----------



## Beefy

Quote: 





tinola said:


> 1) Anyone think upgrading the caps worth it?





>


  2) I am going to get an AXON 91uf maybe.
   


> 3) Also, does black gate caps really make a difference? I was thinking of replacing the other caps to black gates to improve the sound.


 

  
  1) Yes. Output coupling caps are ripe for upgrades.
   
  2) Good, inexpensive choice.
   
  3) Complete and utter waste in this amp. Spend the money on the Speedball and a better volume pot instead.


----------



## roadcykler

For you Crackheads who've actually built one of these, what are some tips and/or hints you might offer future builders? Especially ones with little building experience?


----------



## Beefy

Don't eat the solder.


----------



## Todd R

Quote: 





roadcykler said:


> For you Crackheads who've actually built one of these, what are some tips and/or hints you might offer future builders? Especially ones with little building experience?


 


  Print out the instructions so you have a copy at the workbench. Check off each step as you go.


----------



## Armaegis

Label/number the steps, prep the wires beforehand and lay them out, and carefully read over the placement of those capacitors because there's a couple of them which are a real bear to get in place properly.


----------



## roadcykler

beefy said:


> Don't eat the solder.




I definitely avoid anything with lead in it but silver solder makes my insides all sparkly and clearer.


----------



## maverickronin

Quote: 





roadcykler said:


> I definitely avoid anything with lead in it but silver solder makes my insides all sparkly and clearer.


 
  Don't eat the silver either.  Its not nearly as toxic, but it does have it heath effects.  One of them is turning you into a smurf.


----------



## roadcykler

maverickronin said:


> Don't eat the silver either.  Its not nearly as toxic, but it does have it heath effects.  One of them is turning you into a smurf.




Of course I was joking but that is just odd. I remember colloidal silver was touted as a miracle ingredient to purify water, disinfect things, and keep you healthy. Glad I never fell for it.


----------



## maverickronin

roadcykler said:


> maverickronin said:
> 
> 
> > Don't eat the silver either.  Its not nearly as toxic, but it does have it heath effects.  One of them is turning you into a smurf.
> ...




I figured you were probably joking but its just so weird I can never resist an opportunity to link to it.


----------



## james93

Great builds and even better advice from the people here.
   
  I still haven't built my from the recent GB.  I am planing on building the base tomorrow and the rest little at a time over the week and hope to have it finished next weekend.  That's if work can cooperate like it has this past week.
   
  James


----------



## zlobby

Can anyone recommend a cheaper tube to roll with?  While i'd love to spend $150 for a GEC, its just not in the funds.


----------



## BmWr75

Quote: 





zlobby said:


> Can anyone recommend a cheaper tube to roll with?  While i'd love to spend $150 for a GEC, its just not in the funds.


 

 Look for a 6080 black plate or coke bottle 6AS7 on eBay.


----------



## skeptic

Quote: 





zlobby said:


> Can anyone recommend a cheaper tube to roll with?  While i'd love to spend $150 for a GEC, its just not in the funds.


 

 Can't go wrong with a Tungsol 5998, but they've become _way_ overpriced on ebay.  I'd call around between the various mainstream web retailers and see if you can find any available.  Sites like Tubeworld are generally more expensive than what you can find on ebay, but this doesn't seem to hold true with 5998's.  My Tungsol 7236 (a computer rated version of the 5998 in a straight tube) also sounds quite good in the crack, and can generally be found cheaper than the 5998's.


----------



## Bones13

the Crack + Speedball was my first DIY to make.  A fun project, I am planning more kit work.  It will be a great while before I do a totally DIY tube amp.
   
  1) get a good solder station if funds allow.
  2) be sure to mark the underside of the plate as shown in the instructions.
  3) I put the instructions on my iPad, and could scroll back and forth, and zoom as needed to see things well
  4) Upgrades for me were coupling caps, Goldpoint stepped attenuator, both of which I feel make a big difference.  I also upgraded the tube sockets, and RCA sockets, which are superficial, I did pick tube sockets that mounted PCB boards, which I liked.
  5) I used silver hammertone paint for the finish, and stained the wood with black stain. Of course your tastes need determine this.
   
  A picture of my my build, about half way along is in the Bottlehead forum.  I have the same moniker there.


----------



## ironbut

Quote: 





zlobby said:


> Can anyone recommend a cheaper tube to roll with?  While i'd love to spend $150 for a GEC, its just not in the funds.


 
  Don't overlook buying used tubes also. If you buy used ones from a dealer like Branden @ Tube World, you can be sure that it'll be good for at least half as long as an NOS one sometimes for a quarter of the price. You won't have to wait quite so long for "burn in" either.
  I usually don't buy used tubes from anyone that doesn't have a stake in keeping my business though.


----------



## Feynman

Hi! I just got my bottlehead crack kit this friday and yesterday evening I started to put the things in place, then I noticed that one of the rca-jacks looks really strange, I tried taking a rca-cable to test if it fit and it sure did, do you think it is something I should worry about?

   
  Oh! And also one more thing. I get confused with the safety ground, I currently have two screws left, one philips 3/8" and one normal (star) 3/8" and one #8 lockwasher and one small lockwasher. In the manual it says that I should use  #8 screw, lockwasher, soldertab, lockwasher but I only have ony big lockwasher left and one small, and the small one doesn't fit the screw. 
  And what should I do with the screw thats left? I've read trough the manual several times but I can't figure out where to put the last one.


----------



## Todd R

Post your question here: Bottlehead forum.
  You will get a faster answer


----------



## Feynman

I would have posted in that forum if it weren't for the fact that someone have to approve my member before I can post.


----------



## Yoga Flame

Quote: 





feynman said:


> Hi! I just got my bottlehead crack kit this friday and yesterday evening I started to put the things in place, then I noticed that one of the rca-jacks looks really strange, I tried taking a rca-cable to test if it fit and it sure did, do you think it is something I should worry about?


 

 I would be concerned about the signal and ground contacts shorting together when the RCA cable is connected.


----------



## roadcykler

I got that much anticipated e-mail today telling me the Crack has been shipped.


----------



## Tinola

Same here! Yay! Will finish building by Sunday


----------



## MrDavis

I have my crack and speedball kit to.  Just waiting for the mail man to deliver the Axon film caps so I can start building it.


----------



## skeptic

Quote: 





mrdavis said:


> I have my crack and speedball kit to.  Just waiting for the mail man to deliver the Axon film caps so I can start building it.


 

 I'd say build away.  As Beefy previously advised me, you will want to put in fly leads and zip tie mounts for the Axons before installing your speedball, but the Axons will actually go in last.


----------



## Tinola

skeptic said:


> I'd say build away.  As Beefy previously advised me, you will want to put in fly leads and zip tie mounts for the Axons before installing your speedball, but the Axons will actually go in last.




Sorry for my ignorance, but what are fly leads? Are they just wires soldered to where the capacitor should attach to so it can reach where the axon is placed?


----------



## Beefy

Correct. My post here shows how I did it.


----------



## Tinola

Thanks, am I limited to use a 250V Film cap? I'm looking around for other film caps besides axon and am wondering if there's a minimum uf and volts or maximum uf and volts I can use for the crack. Sorry, I don't know anything about electronics and I'm still new to DIY'ing. I'm getting there though.


----------



## Beefy

The cap should not be rated lower than 160V and 50µF. There is no real maximum, although you would need to make some other tweaks if you go above, say, 200µF.


----------



## MrDavis

Quote: 





beefy said:


> Correct. My post here shows how I did it.


 

 Yep, I've seen your build and have been using it as a benchmark.


----------



## Tinola

beefy said:


> The cap should not be rated lower than 160V and 50µF. There is no real maximum, although you would need to make some other tweaks if you go above, say, 200µF.




Thanks a lot. Now that cleared stuff up.


----------



## skeptic

There was a chart posted on the BH forums a while back looking at the appropriate range for substitute output caps.  (It is referenced in this thread http://www.bottlehead.com/smf/index.php/topic,526.60.html but the link appears to be broken and the image does not display.) 
   
  My recollection is that if you go below a certain threshold capacitance, it will result in bass roll-off, but that threshold varies based on the impedance of your cans.


----------



## milosz

Quote: 





feynman said:


> I would have posted in that forum if it weren't for the fact that someone have to *approve my member* before I can post.


 

  
  I beg your pardon!?!?!


----------



## Tinola

My kit has arrived. I really want to start but I got class until evening...


----------



## skeptic

So I finally got my Speedball kit up and running over the weekend!  With the constant current kit in place, the Crack does indeed sound even more dynamic and enjoyable, with noticeably tighter bass.  I'm absolutely loving the end result with my HD800's.
   
  A couple of quick pointers to any other novice builders who might be able to benefit from the mistakes I made along the way:
   
  (1) if you are new to through-hole soldering (like I was), watch a couple of youtube videos on the subject before giving the speedball a go and potentially making a mess of things.  Understanding how to form a solder bridge, and then to apply the solder from the opposite side of the lead, is invaluable when populating the three boards, and it is really easy once you've seen how its done.  
   
  (2) be as careful as possible when putting in your nylon stand-offs around the 9-pin socket.  I don't know exactly how I managed it, but in shifting the existing wires to the side of the screw holes, I apparently damaged the LED at A8 in the process.  Bottlehead was extremely gracious about shipping me a replacement, and I got some great advice and explanation on the BH forums in handling the testing and repair, but if you can avoid having to partially uninstall your speedball boards to replace a damaged component, your life will be a lot easier


----------



## james93

Well I finally started building my from the last GB.
   
  James


----------



## Armaegis

Whoa, what kind of wacky texture is that?


----------



## james93

It's RustOleum Stone Spray, *Sienna Stone*.  It has a base coat of a brown RustOleum that I already had.
   
  The thing is the more you spray on the rougher the texture gets, I didn't put too many coats on just enough to get a little rough surface.
   
  James


----------



## Flaggro

Just finished my Crack kit this morning.  This was my first DIY kit, and it went pretty well.  The only hiccup I had was that I put way too much solder on the tip of the RCA jack, and it ran down into the ring.  Melted the plastic and caused a short.  Ended up having to replace it, but no biggy.
   
  Thanks to everyone who recommended this thing.  I'm loving it with my DT990s.


----------



## skeptic

Congrats flaggro! 

Sent from my ADR6400L using Tapatalk


----------



## LoweArt

Hey Peoples,
   
  I have been M.I.A. for a while due to work and health related issues. Spied the thread started by Ironbut last year and pulled the trigger with BottleHead and got some of the parts but was able to start to get around to this until April.
   
  I've built kits before and still have my MAD Ear + purist going strong, but wanted to get a feel for the OTL design applied differently ( previously owned an Earmax ) and liked the tubes used and the simplicity of design of the Crack.
   
  Happy to say that once assembled, the unit fired up first time and sang like a champ and before I could fashion a new base to put the unit
  into ( I bought the kit without the wooden base or top plate so I could make my own ), I took the amp around to friends and in between the travel the amp started to fail intermittently with the biasing LEDs not lighting up. Although I wrote to Bottlehead for assistance and they were super quick in replying, some checking and fiddling and hours and hours later I tracked it down to a faulty Electrolytic cap. De-soldered and replaced this capacitor and everything is now back in action !
   
  Hope other Crack owners are loving it as much as I am driving my Sennie HD600's.
   
  Cheers,
  Lok


----------



## roadcykler

Wow, I really like that design. Definitely something much different than anything I've seen. Nice job.
  
  Quote: 





loweart said:


> Hey Peoples,
> 
> I have been M.I.A. for a while due to work and health related issues. Spied the thread started by Ironbut last year and pulled the trigger with BottleHead and got some of the parts but was able to start to get around to this until April.
> 
> ...


----------



## LoweArt

Quote: 





roadcykler said:


> Wow, I really like that design. Definitely something much different than anything I've seen. Nice job.


 

 Thanks for your most kind comments on my custom Bottlehead Crack amp. It's quite simple in that the top plate that also forms the front and rear of the amp chassis is laser cut and bent from a single piece of 0.9mm stainless steel sheet. The wooden sides are then routed so that the stainless steel slides into and is held inside the routed groove. I deliberately made the front panel shorter than the rear so I could finish the bottom off with a curved look with the use of a routed piece of wooden dowel to break up that angular/boxy look.
   
  Why did I choose to re-design the look of the Crack ?  Well, I don't like having all the cables being all plugged into the top of the Crack kit which means all cables have to curve and bend back over the unit ( just thinking of long term cable/connector stresses ). I understand they made the kit this way for ease of assembly and for maintaining a low cost for manufacture.  Since making this, I've already received 2 orders from friends/work mates to make this for them !
   
  Here's a photo of the rear of my Crack amp

   
   
   
  Here's a photo of my first attempt at customising my MAD Ear + purist headphone amp that got me on this path.....
   

  
  Really appreciated your comments/feedback !
   
  Cheers,
  Lok


----------



## Doc B.

Another simple way to have the cables exit horizontally is to use right angle connectors. That is how we configured our listening station at Bottleheadquarters.


----------



## Doc B.

Meant also to say that these kits are looking great, folks. Nice work!


----------



## LoweArt

Thanks for your help/advice Doc B when I had the issue with the BIASING led's coming on and then going off, turned out to be a faulty electrolytic capacitor.


----------



## Doc B.

Curiously that is the first time I've heard of a faulty electrolytic cap straight out of the box except for the rare case where it was damaged in shipping. Did it look dented or otherwise damaged? If so, we will adjust the packaging to avoid that in the future. Glad you got the puzzle solved, good work!


----------



## larcenasb

Some impressions on the Bottlehead Crack:
   
  http://www.head-fi.org/forum/thread/556480/an-audio-odyssey-ending-w-akg-k601-bottlehead-crack-impressions
   
  It may sound like I am not completely for the Crack's sound. But once you read my impressions, I think you will understand my position. So let me just say here, I really am happy w/ the Crack and have no plans to upgrade. I love the Crack's simplicity of design but, more importantly, it reveals to me the magic of my music and that helps keep me sane on a daily basis.


----------



## LoweArt

Quote: 





doc b. said:


> Curiously that is the first time I've heard of a faulty electrolytic cap straight out of the box except for the rare case where it was damaged in shipping. Did it look dented or otherwise damaged? If so, we will adjust the packaging to avoid that in the future. Glad you got the puzzle solved, good work!


 


  It took me a little while to actually find the problem as there was no visible external signs of damage to the capacitor and it was the 1st time that I have ever come across something
  like that and I've been a DIY and kit builder for a while. It turned out that the negative axial lead on the cap was moving around inside the body of the cap, never seen that before !


----------



## larcenasb

Has anyone experimented modifying the Bottlehead Crack w/ an external power supply. I'd like to enjoy music at lower levels w/ full, full, full impact. Any advice on this?
   
  http://www.amazon.com/review/R9ACSP38KYZ2D/ref=cm_cr_dp_cmt?ie=UTF8&ASIN=B001P6FO5E&nodeID=172282&tag=&linkCode=#wasThisHelpful
   
  ...the link above gave me the idea. If one can add a PSU like that to a dac, is it possible to do w/ the Crack?


----------



## williaty

Quote: 





larcenasb said:


> Has anyone experimented modifying the Bottlehead Crack w/ an external power supply. I'd like to enjoy music at lower levels w/ full, full, full impact. Any advice on this?
> 
> http://www.amazon.com/review/R9ACSP38KYZ2D/ref=cm_cr_dp_cmt?ie=UTF8&ASIN=B001P6FO5E&nodeID=172282&tag=&linkCode=#wasThisHelpful
> 
> ...the link above gave me the idea. If one can add a PSU like that to a dac, is it possible to do w/ the Crack?


 
  While in theory, something like that would be possible, in practice, it's just not reasonable to do. First, many of the things inside the Crack take SUBSTANTIALLY different voltages. The power supply built into it takes care of this. It's not set up to be fed from a single DC voltage level at all. Second, the power supply in Bottlehead kits is almost always VERY good. They don't screw around with that kind of stuff. So finding a power supply that's actually better than the one you build is going to be a hard (though possible) task.
   
  The most common way of improving the power supply, if you really feel you have to, is to move the power circuit from the main kit into its own enclosure to facilitate the use of chokes, bigger caps, etc. However, to do this, you're on your own and better have a very good understanding of electrical engineering and how the Crack's circuits operate.
   
  If you want to substantially improve the Crack, just add the Speedball. My Crack and Speedball are still in the mail, but the Speedball is the same basic kind of circuit as the Anticipation in the original Foreplay 1 and 2. Having built that myself, the circuit upgrade WORKS.


----------



## Armaegis

Um... not really. You wouldn't use an external power supply with the Crack unless you're doing some very heavy duty modding. You could use a power conditioner though.
   
  In that link, the user replaced a wallwart (which I'm guessing was a simple AC->DC converter) with a higher quality AC->DC converter. The Crack doesn't have a wallwart, and instead feeds AC directly into it's own custom made transformer. You gotta have some pretty good DIY chops if you're going to replace their transformer with something else.


----------



## larcenasb

Thanks Williaty & Armaegis -- I am grateful for your responses.
   
  Yes, I just didn't have an understanding of why that wouldn't work.
   
  I have a new idea though! What are the possibilities of using two Cracks in a balanced mode? First getting Moon-Audio's balanced XLR cable upgrade, and then buying two XLR female to 1/4 male adapters (pictures below). What do you guys think would be the resulting sound of doing that? More power? Thank you very much for your time.


----------



## BmWr75

The Crack amp is OTL, which does not work well with low impedance cans like your AKGs.


----------



## Doc B.

Quote: 





larcenasb said:


> Has anyone experimented modifying the Bottlehead Crack w/ an external power supply. I'd like to enjoy music at lower levels w/ full, full, full impact. Any advice on this?
> 
> http://www.amazon.com/review/R9ACSP38KYZ2D/ref=cm_cr_dp_cmt?ie=UTF8&ASIN=B001P6FO5E&nodeID=172282&tag=&linkCode=#wasThisHelpful
> 
> ...the link above gave me the idea. If one can add a PSU like that to a dac, is it possible to do w/ the Crack?


 

 The poster suggesting that the 62 ohm headphones you are using might not be the best match probably has the most plausible explanation, since the Crack is designed to run headphones over 120 ohms impedance and specifically to be optimal with those in the 300 to 600 ohm range. It could also be that the output level of your source is a bit low with respect to the gain structure of the Crack. The stock power supply is actually overkill, we use the same setup in an amp that puts out 2 watts per channel. We are working on a new kit called Smack that will have transformer output with taps at 16/32/64/128 ohms and the ability to be wired for balanced output at at least one of those impedances. It should prove to be more appropriate for lower impedance headphones that the Crack amp was not designed to use, like the K701. At this point your best bet might be to replace the 6080 with a 5998 which will lower the output impedance to around 70 ohms.


----------



## Armaegis

Quote: 





larcenasb said:


> I have a new idea though! What are the possibilities of using two Cracks in a balanced mode? First getting Moon-Audio's balanced XLR cable upgrade, and then buying two XLR female to 1/4 male adapters (pictures below). What do you guys think would be the resulting sound of doing that? More power? Thank you very much for your time.


 

 Should be doable. I've been wanting to try that myself actually.


----------



## larcenasb

I'm sorry, I only posted the picture of the K701 'cause that's the only one moon-audio had w/ the balanced cabling. I have the K601, 120 ohms. I am in fact using a Tung-Sol 5998 tube, is that not the ideal match for my headphones? Should I use a 6AS7/6080? Thanks so much for your time.


----------



## Beefy

Frankly, the whole amp isn't the best match for your headphones, even with the 5998. Your damping factor is only just above 1, which isn't enough to grab the driver by the cojones.
   
  Some people are happy with the Crack on lower impedance phones like the K601, but the higher the better IMHO.
  
  Quote: 





larcenasb said:


> I'm sorry, I only posted the picture of the K701 'cause that's the only one moon-audio had w/ the balanced cabling. I have the K601, 120 ohms. I am in fact using a Tung-Sol 5998 tube, is that not the ideal match for my headphones? Should I use a 6AS7/6080? Thanks so much for your time.


----------



## Doc B.

5998 will be the best choice. When you say you want low levels with full impact I must admit that I was a bit confused. I wasn't really clear if you meant the amp isn't playing loud enough (low levels) or if you meant the headphones are lacking low _frequency_ punch. Presumably you mean the latter. I have found the K601s and K701s kinda bass light in general, and I'm not sure I have much to offer in terms of improving that beyond installing the Speedball upgrade if you have not already done so. It does tighten up the bass over the stock configuration.


----------



## larcenasb

Ha! I'm sorry, I really should be more clear! I'm actually very happy w/ the bass performance through the Crack. I meant at low _volume_ levels, I would love to be able to hear the same impact as with higher volume levels -- would it still be called "headroom" like w/ speakers? I'm thinking of getting Beyerdynamic DT 880s 600 ohms; would the higher impedance yield the powerful sound @ any volume level that I'm looking for? Thanks so much Doc for being so responsive.


----------



## Doc B.

I think maybe we are talking about the overall dynamic range. To put it a bit converse to the way you are stating it, the quiet parts aren't quiet enough for you when you have the volume turned up to where you like the transient peaks. For what it's worth I haven't heard a complaint about the Crack being compressed sounding. The only real complaints have been about flabby bass when using the Crack with low impedance headphones, and that is certainly logical given the nature of the circuit. That said, headphones all behave a little differently and I haven't logged much time with the AKGs so I can't speak very intelligently about that exact setup. My SWAG is this could be a case of compression from the source rather than compression at the headphone amp or headphones. Before you change headphones you might experiment with different music and, if possible, different front end gear and see if the problem changes character at all.


----------



## tdogzthmn

Quote: 





larcenasb said:


> Ha! I'm sorry, I really should be more clear! I'm actually very happy w/ the bass performance through the Crack. I meant at low _volume_ levels, I would love to be able to hear the same impact as with higher volume levels -- would it still be called "headroom" like w/ speakers? I'm thinking of getting Beyerdynamic DT 880s 600 ohms; would the higher impedance yield the powerful sound @ any volume level that I'm looking for? Thanks so much Doc for being so responsive.


 


   
 [size=medium]I own a K500 (120ohm) and a HD600 (300ohm)  and my crack is running a 5998 with speedball.  Listening between these two cans , I can definitely hear more control and precision with the HD600.  I can also say that you will get "more" sound at lower volumes with higher impedance cans.  I always have to turn the volume up a good amount when switching from the HD600 to the K500.  Hope my experiences can help with your decision.​[/size]


----------



## ccklone

Hey Now,
   
  Just finished up my Crack today. Woo-hoo, it sounds terrific with the HD650s as many have stated. Really enjoying it. 
   
  I had to re-solder a cold joint to get the right channel to play, otherwise it was a very enjoyable build. I love the Bottlehead support and instructions. I bought the Crack and Speedball together, but am going to listen to the stock Crack for a while before doing the Speedball upgrade. I already got some tubes for rolling, a Sylvania and Electro-Harmonix. 
   
  I wanna build something else, maybe a Foreplay?
   
  --
  Finest kind,
  Chris


----------



## Tinola

ccklone said:


> Hey Now,
> 
> Just finished up my Crack today. Woo-hoo, it sounds terrific with the HD650s as many have stated. Really enjoying it.
> 
> ...




Update the caps! LoL, I plan on upgrading my caps soon as a "summer" project. It's going to be expensive -_-. I'll probably get the speedball as well.


----------



## c540

Here is a quick pic of my crack/speedball :
   
  This still needs to be finished, but I put it back together to listen for a few days until I have time to sand, re-coat and add the finishing touches...(new knob, cap the side holes, ect.)


----------



## bcg27

Very unique look, I like it. Is it all wood?


----------



## c540

Yes, it is all wood, I wanted to keep it simple and inexpensive. I have been buying a lot of tubes lately!


----------



## larcenasb

Due to tight finances, I have to part ways w/ my Bottlehead Crack.
   
  http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280698792806&ssPageName=STRK:MESELX:IT
   
  Good day.


----------



## Arainach

I was the lucky individual who picked up larcenasb's Crack.  Sounds like heaven with my HD650s so far.


----------



## tdogzthmn

Quote: 





arainach said:


> I was the lucky individual who picked up larcenasb's Crack.  Sounds like heaven with my HD650s so far.


 


  I also really enjoy my ER4S with the Crack.  Lots of rich texture and detail!


----------



## roadcykler

Did you design that yourself or find plans somewhere? That is outstanding. My creativity level is near zero but I can build lots of stuff if I had the plans. 
  
  Quote: 





c540 said:


> Here is a quick pic of my crack/speedball :
> 
> This still needs to be finished, but I put it back together to listen for a few days until I have time to sand, re-coat and add the finishing touches...(new knob, cap the side holes, ect.)


----------



## c540

Thank you for the kind comments! I did design it myself and cut everything on a sliding compound miter saw and a table saw. I still haven't gotten around to the recoat...
   
  I bought Skylab's custom Bottlehead, but the chassis was a bit big for everyday use. (I can easily replace the panel to the original build in the future)
   
  I am using a Nuforce HDP as a DAC/Preamp and for tubes:
   
  Tung-sol 5998 and RCA 6as7g
   
  12au7's:
  Tung-sol black glass
  Westinghouse blackplates
  Amperex Bugle Boy
  Brimar 13d5's
  RCA blackplates
  RCA Cleartop
  +
  Amperex 6085.
   
  It sounds GREAT paired with the HD800's and the Dt880's!


----------



## williaty

Quote: 





skylab said:


> Oh-oh...lookie what I bought...custom build Crack Bottlehead w/Speedball...


 

 Skylab, what's the designation for that Genelec tube? I've been trying to google to find a Genelec version of the 6080/6AS7G but I'm coming up with no joy.


----------



## tdogzthmn

^ G.E.C makes those tubes.  I believe Genelec is a Finnish company that makes monitor speakers.


----------



## williaty

Odd. I'd heard them as G.E.C. (General Electric Company, the British one, not the American one) and shortened to Genelec. That's what I get for watching videos on the internet :lol:


----------



## Doc B.

Quote: 





tdogzthmn said:


> ^ G.E.C makes those tubes.  I believe Genelec is a Finnish company that makes monitor speakers.


 

 Yeah, the tube brand name is Genele*x*, not Genele*c*. It's confusing because a pair of the speakers is usually referred to in plural -  "Genelecs" in a studio.


----------



## williaty

Quote: 





doc b. said:


> Yeah, the tube brand name is Genele*x*, not Genele*c*. It's confusing because a pair of the speakers is usually referred to in plural -  "Genelecs" in a studio.


 
  So then is Genelex, the tube maker, the same as G.E.C., the tube maker?


----------



## BmWr75

Quote: 





williaty said:


> So then is Genelex, the tube maker, the same as G.E.C., the tube maker?


 

 Originally it was.  Also have seen Marconi Osram name associated with the G.E.C./Genelex name.  I think both are just short for General Electric Corporation.
   
  I say originally it was because New Sensor now owns the "Genalex" name (don't know why spelling is different) and is selling Russian made tubes under the name.
   
  Brent Jesse - tube expert says this "*KT-66:* This version is the European equivalent to the 6L6GC and the 7581 type. These often have a fairly large coke bottle ST shape, and are found in both clearglass and greyglass. They can be used to replace virtually any 6L6 type. Most of those available were made by the *Marconi*-*Osram* Valve Co., under their Genalex label, or may be found with either the "*Marconi*" or "*Osram*" label. A premium audiophile version was introduced in the late 1950s under their "Gold Lion" label. These were screened for audio use, with handwritten data sheets included in the box with the tube."


----------



## Skylab

Not sure about that. But that tube is a GEC 6AS7G, which is, IMHO, the finest sounding 6AS7G there is, although they are the very devil to find, and expensive as the devil when you do.


----------



## tdogzthmn

Are there any companies today that make vacuum tubes today using modern materials and design approach?  I know its not a high demand product but it would be interesting to hear what sound might be achievable using the advancements we have today to revisit the design. 
   
  And it would be even better if it was able to work in my Crack!


----------



## BmWr75

Quote: 





skylab said:


> Not sure about that. But that tube is a GEC 6AS7G, which is, IMHO, the finest sounding 6AS7G there is, although they are the very devil to find, and expensive as the devil when you do.


 


  Sorry, knew when I posted that I should have mentioned Brent's comment was on a KT-66, not the 6080/6AS7G required by the Crack.


----------



## Skylab

tdogzthmn said:


> Are there any companies today that make vacuum tubes today using modern materials and design approach?  I know its not a high demand product but it would be interesting to hear what sound might be achievable using the advancements we have today to revisit the design.
> 
> And it would be even better if it was able to work in my Crack!


The only recent example I know of this was a year or so ago a company called Blackburn Microtech started to make tubes at the famous former Mullard factory in Blackburn, Lancashire. They made 12AX7 and 12AU7's which were a totally fresh design. Sadly, the company, which made other products besides the new tube venture, went bankrupt before more than a small number of the tubes were sold. I have a pair and found them to be very good sounding. Pity.

Almost all other current-production tubes are basically working hard to copy tubes of the past. 

One other thing - there a no current-production 6AS7/6080 tube types made. However, there are truly mountains of the Russian and Chinese equivalents.


----------



## LoweArt

Quote: 





skylab said:


> Not sure about that. But that tube is a GEC 6AS7G, which is, IMHO, the finest sounding 6AS7G there is, although they are the very devil to find, and expensive as the devil when you do.


 


 +1


----------



## RingingEars

Hey all. New guy here.
  I've been lurking for a few months now. Since finding this site I have been growing more obsessed with headphone Hi-Fi. It started with a pair of ATH-A700 then a pair of ATH-EW9 to go with my Sanza Clip+/Ebay CMoy amp combo. Since then, and through all the great info on this site, I have set up foobar, purchased DB PowerAmp and ripped all my CDs to FLAC. I have an NOS Valab DAC that I run on my Hi-FI system that I have moved over to the computer until my Fubar II MKII comes in and I also bought one of the Topping TP21 amps along with the Dayton dta 100a. I'm keeping the Topping and sending the Dayton back, that amp is sketchy to say the least.
  Anyway. So now I'm hooked and I just ordered one of the Crack Amps(should be a fun build). I have a Dynaco ST-70 on my Hi-Fi system and I love the tube sound so I figured the Crack would be a great amp for headphones.
  I'll be using my low impedance ATH-A700 for now so I don't expect the wow factor, but I will be picking up a pair of HD600 in a month.


----------



## skeptic

Just don't judge the crack based on its performance with your a700's. I plugged in a pair of ad700's to mine for kicks and they sounded incredibly thin/anemic. 

The amp is outstanding paired with Senns and Beyers though. Congrats on your purchase!

Sent from my ADR6400L using Tapatalk


----------



## RingingEars

Oh no. I won't. I've done enough research here and and elsewhere to know that the Crack was not designed around low impedance phones so I'll reserve judgment for the Sennheisers. 
	

	
	
		
		

		
		
	


	



  Quote: 





skeptic said:


> Just don't judge the crack based on its performance with your a700's. I plugged in a pair of ad700's to mine for kicks and they sounded incredibly thin/anemic.
> 
> The amp is outstanding paired with Senns and Beyers though. Congrats on your purchase!
> 
> Sent from my ADR6400L using Tapatalk


----------



## BmWr75

The Crack sounds really bad with low impedance cans.  I will not listen to it with my AKG K702s, but it sounds great with 600 ohm Beyerdynamic cans.


----------



## RingingEars

Are you the same BmW @ AudioKarma? Good to see you. 
	

	
	
		
		

		
		
	


	



  Yeah I can't wait to get the Senns. The Crack will be my first audio DIY. I've soldered in the past... Cables, bay buses for computers, just a few simple things so this will be a fun and challenging project. Hopefully it's here for the three day weekend. 
	

	
	
		
		

		
		
	


	



  Quote: 





bmwr75 said:


> The Crack sounds really bad with low impedance cans.  I will not listen to it with my AKG K702s, but it sounds great with 600 ohm Beyerdynamic cans.


----------



## BmWr75

One in the same.


----------



## RingingEars

Anyone know an approx. shipping schedule on the next batch?


----------



## bcg27

^^
   
  This page gives updates on the shipping status of the various Bottlehead offerings: http://www.bottlehead.com/et/deliverystatus.htm


----------



## Doc B.

We are awaiting a new shipment of chassis plates. Apparently the company that laser cuts the panels for us had to find a new company to grain finish the panels for them, and this has caused a bit of a delay. We were hoping to see the panels by the end of this week, so hopefully we'll see them sometime next week.


----------



## RingingEars

Quote: 





doc b. said:


> We are awaiting a new shipment of chassis plates. Apparently the company that laser cuts the panels for us had to find a new company to grain finish the panels for them, and this has caused a bit of a delay. We were hoping to see the panels by the end of this week, so hopefully we'll see them sometime next week.


 


  Thanks for info Doc. Appreciate it. I'm looking forward to this build and the tweaking that will come later.


----------



## thewolf1976

I am thinking about adding a set of inputs and a toggle switch to my Crack. What is the best way to drill holes in the plate? I have a stepped drill bit and also a dremel. Do I need a punch, then drill? I don't want to screw up my plate.


----------



## Aart

I'd post this on the bottlehead forum but I'm still awaiting my approval.
   
  There is a possibility that one of my LEDs (HLMP-6000) is broken, I know bottlehead will ship me new LEDs if I ask for it but shipping x LEDs from America to Europa seems "meh..." 
   
  Called my local electronics shop and asked for "HLMP-6000", they didn't have those but the person on the phone did take a look at the datasheet and told me it looked like a regular LED. This true? I can just go to that store and get a normal LED and it'll work? Or should I ask for something more specific?


----------



## williaty

You need to match the specs listed on the datasheet exactly. Small differences matter.


----------



## Beefy

Quote: 





aart said:


> Called my local electronics shop and asked for "HLMP-6000", they didn't have those but the person on the phone did take a look at the datasheet and told me it looked like a regular LED. This true? I can just go to that store and get a normal LED and it'll work? Or should I ask for something more specific?


 

 That LED is commonly used in tube amps for a very specific reason - it has a very low and flat dynamic resistance. You can match the specs to build the amp initially without 'hurting' anything, But ultimately, you do want to replace it with the correct LED.


----------



## Doc B.

Beefy is right that we have chosen the HLMP-6000 for its linearity at low currents. The most important consideration is that the HLMP-6000 has a voltage drop of 1.56V. If you do decide to use some other LED it must have that same voltage drop, that is to say a 2V or other voltage drop will not set the current to the proper value.


----------



## RingingEars

Man Doc. I'm chomping at the bit. I even bought myself a new soldering station just for this build.


----------



## tdogzthmn

Has anyone experienced good synergy with a particular DAC and their Crack?  I have been meaning to pick up a good DAC to pair with my crack but I would like to hear what users are having good experiences with!


----------



## williaty

My setup of a HRT MusicStreamer II+, Crack+Speedball, and Sennheiser HD600s is working EXTREMELY well. They all seem to want to present the music in a particular way that's very clear, very revealing, but at the same time not pushy or fatiguing. They just sort of get out of the way really well.


----------



## BmWr75

Crack+Speedball and a Cambridge Audio DACMagic work very well together for me.


----------



## skeptic

In truth, any competent dac will probably sound really good with your crack.  nick_charles' posts in this sound science thread regarding dac performance are definitely worth a read: http://www.head-fi.org/forum/thread/560122/all-dac-s-sound-the-same/150#post_7571556

  I'm continuing to thoroughly enjoy my current setup, from pc -> blue circle usb "thingee" -> keces 131 dac -> crack -> HD800.  That said, I'm also really looking forward to the release of bottlehead's dac kit.


----------



## RingingEars

As soon as I get mine in and built I'll report with the Fubar II MKII running both the LM4562 and the AD797AN chips. I'll also run it with the stock NOS Valab.


----------



## tdogzthmn

williaty said:


> My setup of a HRT MusicStreamer II+, Crack+Speedball, and Sennheiser HD600s is working EXTREMELY well. They all seem to want to present the music in a particular way that's very clear, very revealing, but at the same time not pushy or fatiguing. They just sort of get out of the way really well.




I have basically the same setup minus the music streamer DAC so it's good to hear it's working well for you. I really think the crack does a great job of creating a very life like sound with great detail and I'm hoping to keep those great qualities. I do know bottlehead has been working on a dac but no release date has been given as of yet.


----------



## williaty

Quote: 





tdogzthmn said:


> I have basically the same setup minus the music streamer DAC so it's good to hear it's working well for you. I really think the crack does a great job of creating a very life like sound with great detail and I'm hoping to keep those great qualities. I do know bottlehead has been working on a dac but no release date has been given as of yet.


 
  I remain hopeful but skeptical, if that makes any sense, of the Bottlehead DAC. I have a great deal of respect for their engineering ability and a great deal of faith in their drive to produce good products, which is the reason that I'm hopeful. I became very worried when I heard they were going to use a non-oversampling (aka NOS, R2R) circuit topology. While it's possible to end up with a good product using an R2R topology, there's just so many significant technological limitations to that circuit design that I am left wondering why they chose it. It's a way of doing it that sounds good at first, but when you look at some of the secondary and tertiary consequences of using R2R, it just stops making sense. Sure, you could fight a boxing match with one hand behind your back and a 3-weight class disadvantage, but the odd are not in your favor for it ending well. I will be very interested to hear what their final result sounds like.


----------



## skeptic

Williaty - is there an article or site you could link that discusses the pros and cons of nos vs. oversampling dacs? I'd be very interested to read more on the topic and about the limitations you referenced. Thanks!

Sent from my ADR6400L using Tapatalk


----------



## williaty

Quote: 





skeptic said:


> Williaty - is there an article or site you could link that discusses the pros and cons of nos vs. oversampling dacs? I'd be very interested to read more on the topic and about the limitations you referenced. Thanks!
> 
> Sent from my ADR6400L using Tapatalk


 
  I did find one but I didn't bookmark it again after I read through it since I didn't think I'd ever be designing a DAC. I would imagine a bit of googling for something like "R2R vs DS DAC" or "non-oversampling vs sigma-delta DAC" would probably turn up good discussions. You'll want to read the ones with engineers talking, not audiophiles.


----------



## Armaegis

Here's my latest shot of Crack. I had a rather embarrassing episode when I turned it on the first time and nothing happened, and I spent an hour checking and rechecking all my connections only to discover that I didn't have my extension cord plugged in 
	

	
	
		
		

		
			




   
  Painting and staining probably took longer than the amp assembly itself. I'm half decent with a soldering iron, but my woodworking still needs work 
   

   
  Only one channel working so far. One of my tube bias LEDs is dead 
	

	
	
		
		

		
		
	


	




 so I'm waiting on replacement.
   
  It's also amazing how much easier life is when you clip all your wires ahead of time...


----------



## tdogzthmn

How do you like the K240 with the Crack?  Im a big fan of the old AKG models.  
  
  Quote: 





armaegis said:


> Here's my latest shot of Crack. I had a rather embarrassing episode when I turned it on the first time and nothing happened, and I spent an hour checking and rechecking all my connections only to discover that I didn't have my extension cord plugged in
> 
> 
> 
> ...


----------



## Armaegis

That's my NOS K240 Sextett MP, and it is easily my favourite pairing out of all the gear I've tried so far (which is quite a lot). It's got a great midrange forwardness that brings vocals to front and centre, while being able to keep up with a reasonably deep bottom end.
   
  Sadly, it gets almost no head time as I'm rarely home. Heck, I barely even use my portables. I should probably just sell it all to fund other things...


----------



## RingingEars

I received my shipping notification today. Kit will be here tomorrow and I'll order my HD600 on Fri. This is going to be a good weekend.


----------



## RingingEars

Got it done today.
  It sounds great. Now I just need to finish the base.


----------



## skeptic

Way to get her done RE!  Looks like you may have been enjoying good sound and good beer together per your photo


----------



## RingingEars

Quote: 





skeptic said:


> Way to get her done RE!  Looks like you may have been enjoying good sound and good beer together per your photo


 

 Yeah I got after it Fri when I got home from  work and saw the box sitting there. I only live 6 hours from Bottlehead head quarters so it was only a 1 day turn around on shipping.
  Nothing like a good Chimay and good music to set the soul right.
  I kind of like the amp in the "raw" so I may just oil the base and call it good.
  Here are the build pics:


----------



## MrDavis

My crack + speedball + some upgrades is coming along slowly but surely.


----------



## RingingEars

^^^That's going to be a nice build when it's done.


----------



## caracara08

ugh im so jealous.  i wish i had DIY skills.  nice job! it looks great.


----------



## RingingEars

Quote: 





caracara08 said:


> ugh im so jealous.  i wish i had DIY skills.  nice job! it looks great.


 


  The crack is a lot easier to build than you think. If I can build one anyone can.
	

	
	
		
		

		
		
	


	



  The included instructions pretty much "hold your hand" through the whole process. Some of the best instructions I've ever seen in a kit.


----------



## skeptic

Quote:


caracara08 said:


> ugh im so jealous.  i wish i had DIY skills.  nice job! it looks great.


 
  Edit: RE beat me to the punch here - but to echo his comment...

 No need for jealousy.  The stock crack really is a beginner project.  It was my first build aside from terminating some cables, and the step by step instructions (accompanied by color photos) really are good enough to let a total novice (like me) fumble his/her way from start to finish and come out with a **** nice amp. 
   
  If you have access to an adequately hot iron (or preferably a soldering station), a youtube video or two will teach you a lot more than you need to know to knock it out.  The through-hole soldering required to complete the speedball upgrade requires some minor skill and a basic understanding of how to form a solder bridge, and then to apply heat from the opposite side of the lead, but again, 10 minutes on youtube will have you in fine form to populate the boards.
   
  This thread and the BH forum are also great resources due to the awesome community that has formed around this amp and the frequent help and input provided by the folks at BH.


----------



## Armaegis

The Crack is a fairly easy build. The only part that gets me is the placement of those capacitors. Ugh, stupid fumbling balancing act there. 
   
  I also highly recommend cutting and stripping the majority of the wires ahead of time. This makes your life much easier as you build.


----------



## breakfastchef

I built an entire Bottlehead system shortly after building a few CMOY amps. The instructions are very thorough; you just need to learn how to use your soldering iron to make good joints. My Bottlehead system includes two Paramounts (300b mono block amps; one for each channnel), Seduction (phono pre-amp), and Foreplay III (pre-amp). All worked from the start. Follow the directions, take your time and anyone can build a Bottlehead kit.
   
  I am smitten by the Crack and long to build one. After selling my HD650's and Woo Audio WA6SE, I still yearn for the times I would have slipped on the headphones and escaped for a little while.


----------



## RingingEars

Quote: 





breakfastchef said:


> I buit an entire Bottlehead system shortly after building a few CMOY amps. The instructions are very thorough; you just need to learn how to use your soldering iron to make good joints. My Bottlehead system includes two Paramount (mono block amps; one for each channnel), Seduction (phono pre-amp), and Foreplay III (pre-amp) all worked from the start. Follow the directions, take your time and anyone can build a Bottlehead kit.
> 
> I am smitten by the Crack and long to build one. After selling my HD650's and Woo Audio WA6SE, I still yearn for the times I would have slipped on the headphones and escaped for a little while.


 

 You owe it to yourself to build the crack breakfastchef.
  Sounds like you have a very nice system.


----------



## boirefish

I can't speak for the crack's performance, but all I can say is Elaine and Doc at bottlehead are the best people I've ever dealt with. They responded to all my emails and addressed all the problems I ran into, even though the issues were all caused by me. A fantastic couple (and company) . I would definitely recommend them if you are considering purchasing a diy amp, or anything that they offer.
   
  thanks for all the trouble Elaine & Doc


----------



## MilesDavis2

I can back that statement as I spoke to both and they are just plain GREAT!  In fact I told Doc that talking to him is just great as I have spoken to some audio sellers that just thinks that they're a gift to the audio world. One thing's for sure, you don't get my dinero.
  Quote: 





boirefish said:


> I can't speak for the crack's performance, but all I can say is Elaine and Doc at bottlehead are the best people I've ever dealt with. They responded to all my emails and addressed all the problems I ran into, even though the issues were all caused by me. A fantastic couple (and company) . I would definitely recommend them if you are considering purchasing a diy amp, or anything that they offer.
> 
> thanks for all the trouble Elaine & Doc


----------



## tdogzthmn

The Crack fead by the HRT II + is quite impressive.


----------



## williaty

Quote: 





tdogzthmn said:


> The Crack fead by the HRT II + is quite impressive.


 


  Yes it is! HRT MSII+>Crack+Speedball>HD600 is quite a nice setup for a lot less money than you'd expect to pay for sound this good.


----------



## tdogzthmn

Winning combo here!  I'm glad to be part of the club.
   
  Cheers


----------



## Armaegis

I feed mine with the lineout from my iBasso D10.


----------



## RingingEars

I feed mine with a Fubar II MKII. I'm kind of partial to an NOS DAC. I really like the Fubar for it's versatility. I've rolled a couple different op-amps in it.


----------



## MrDavis

I'm just using a grubDAC.


----------



## sennheiserhd485

I am almost ready to buy the Crack. How does this work with the shipping? Do I have to wait until they get some in? Also, will the DT880/600 synergize well with the stock Crack?


----------



## Armaegis

You place your order, wait a bit until they have all the parts on stock (if they don't already), then they ship it to you. 
   
  It pairs very well with the DT880/600. I used to have one and it sounded good (and this coming from a guy who doesn't like Beyers).


----------



## RingingEars

Quote: 





sennheiserhd485 said:


> I am almost ready to buy the Crack. How does this work with the shipping? Do I have to wait until they get some in? Also, will the DT880/600 synergize well with the stock Crack?


 


  Generally it takes 3-4 weeks to get in.
  The Crack, in it's stock form, pairs very well with the DT 880/600. I haven't done the speedball upgrade yet, but I did order a coupe AXON 91uF caps and an Alps blue velvet pot yesterday. Speedball will be next. Also thinking of swapping the stock 1/4" jack for a Neutrik locking style.


----------



## captouch

Anyone in the Bay Area interested in getting a Crack kit?  I'm interested and we can save $22 each by buying 2.


----------



## Aart

Bought a pair of tung sol 5998 tubes.
  These work together with the standard (the one that came with the kit) "little" tube, right?


----------



## BmWr75

Quote: 





aart said:


> Bought a pair of tung sol 5998 tubes.
> These work together with the standard (the one that came with the kit) "little" tube, right?


 


  Correct.  The 5998 tube is equivalent to the 6080 power tube that came in the amp.  6AS7G is another equivalent.


----------



## Doc B.

The 6AS7G is essentially equivalent. The 5998 is actually a little bit different spec, but for this circuit it can be considered equivalent and plugs right in. I happen to like the sound of the 5998s I've used a wee bit better than the 6080 or 6AS7, but YMMV.


----------



## c540

I am also a fan of the 5998! 
   
  Doc, I remember reading that the 5998 lowers the output impedance to about 50 ohms, is this correct?
   
  The 5998 sounds great paired with a tungsol black glass and a bugle boy 12au7a.


----------



## Doc B.

In the Crack it probably lowers the output impedance to more like 90 to 100 ohms.


----------



## c540

Thanks Doc!


----------



## MrDavis

I finally finished my Bottlehead Crack + Speedball + Upgrades.  Its painted with rustoleum hammered copper and the wood has a gloss finish on it.
   

Upgrades

 Speedball
 Neutrik locking jack
 TKD 2CP2511 100kohm pot
 Genuine Sylvania Pilot Light
 2.2µF Axon film bypass cap on the last power supply cap _(Probably don't need this with a choke installed?)_
 Triad C7X  choke replacing the last power supply resistor
 Axon 91µF/250V output film caps
   
Tubes
   
  Currently using a Tung-sol  5998 and JJ ECC82


----------



## aroldan

Whoa! beautiful!. What tubes are those?
  
  Quote: 





mrdavis said:


> I finally finished my Bottlehead Crack + Speedball + Upgrades.  Its painted with rustoleum hammered copper and the wood has a gloss finish on it.
> 
> 
> Upgrades
> ...


----------



## RingingEars

Nice work MrDavis. I'll be installing my AXON 91µF caps and Alps blue velvet pot later this afternoon.
  Have you had a chance to A/B the resistor/choke? Do you notice a substantial difference(or any difference) between the two configurations?


----------



## MrDavis

It was a subtle difference.  I'm still new at this hobby and really don't know how to describe it.  Anyway, it was an inexpensive upgrade. 
	

	
	
		
		

		
			




  
  Quote: 





ringingears said:


> Nice work MrDavis. I'll be installing my AXON 91µF caps and Alps blue velvet pot later this afternoon.
> Have you had a chance to A/B the resistor/choke? Do you notice a substantial difference(or any difference) between the two configurations?


----------



## RingingEars

Quote: 





mrdavis said:


> It was a subtle difference.  I'm still new at this hobby and really don't know how to describe it.  Anyway, it was an inexpensive upgrade.


 
  That's what's so nice about the crack. It's an inexpensive amp to begin with and you can upgrade it pretty inexpensively also and it sounds flat out great with high impedance cans.


----------



## BmWr75

Any idea which of these mods had the greatest impact on improving the sonics?  My guess is the large caps.​

  Quote: 





mrdavis said:


> I finally finished my Bottlehead Crack + Speedball + Upgrades.  Its painted with rustoleum hammered copper and the wood has a gloss finish on it.
> 
> 
> Upgrades
> ...


----------



## MrDavis

My ears liked the Tung-sol  5998 tube upgrade the most.  Followed by the large caps.
  
  Quote: 





bmwr75 said:


> Any idea which of these mods had the greatest impact on improving the sonics?  My guess is the large caps.​


----------



## RingingEars

Quote: 





mrdavis said:


> My ears liked the Tung-sol  5998 tube upgrade the most.  Followed by the large caps.


 


  Even more-so than the speedball upgrade or did that go in right away?


----------



## MrDavis

The speedball went in first and then a day or two later the caps went in.  I didn't spend much time comparing the difference. The tung-sol 5998 tube is the one that really stands out. Its gives the amp more clarity and tighter bass.  My ears really like it.  YMMV.
  
  Quote: 





ringingears said:


> Even more-so than the speedball upgrade or did that go in right away?


----------



## RingingEars

I've heard that from more than one person. The 5998 sounds like the way to go. I'm running an RCA 6AS7G at the moment. I love the ST shaped tubes, but didn't hear a big difference between it and the stock 6080. The new caps and pot are going in in the next couple hours. I'll report back.


----------



## Beefy

Quote: 





bmwr75 said:


> Any idea which of these mods had the greatest impact on improving the sonics?  My guess is the large caps.​


 

 In my build, the Speedball was the first upgrade and made by far the biggest improvement.


----------



## captouch

beefy said:


> In my build, the Speedball was the first upgrade and made by far the biggest improvement.




Have you tube swapped at all?


----------



## Beefy

Quote: 





captouch said:


> Have you tube swapped at all?


 

 I have tried several 12AU7/12BH7 options for the driver, and a couple of 6AS7/5998 for the power tube.
   
  Swapping the driver tube makes very little difference, while the 5998 offers a small additional improvement over 6080/6AS7 - but not nearly as much as the Speedball.


----------



## BmWr75

Quote: 





beefy said:


> In my build, the Speedball was the first upgrade and made by far the biggest improvement.


 

 I built my Crack with the Speedball from the get go, so never heard it without the Speedball upgrade.


----------



## RingingEars

The speedball will be the next upgrade to go in mine.
  I just love huge caps and the cheap stereo pot had to go so now that I have that out of my system I'll do the speedball.
  I do notice a small sonic improvement in the cap/pot upgrade I did last night. It brought the mids forward a little more on the DT880 and made the highs clearer.
  I hear a lot about the DT880 highs being a little overwhelming, but I have never noticed it. They always sound smooth to me paired with the stock crack and now with the upgrades even more-so. I'm loving it so far. I would like to try other tube or even some SS amps with the Beyers just so I can have some comparative notes, but so far I don't see any reason too.


----------



## tdogzthmn

Are any Crack owners looking to get a Smack amp?  I wonder if it would make a good compliment.


----------



## Armaegis

I should have a Smack coming in as soon as they get their first run of their kits finished up.


----------



## Oberst Oswald

I built the SEX 2.1 and am more than happy with it.  The sound is excellent with the 3 dynamic headphones that I have.  Bottlehead is on a roll with the 3 headphone amps and should be interesting reading to compare the 3 amps with, lets say, Senn HD 800 with is in the middle at 300 ohms to be fair.


----------



## tdogzthmn

I fully agree that a threesome review of these amps is a must. I would be more than willing to do such a review but it will take some time for me to get all three in my possession. I would also say the HD600 would make a good can to use due its popularity and that most of these amps were built using the HD600 as a reference point.


----------



## RingingEars

It would be nice to try the Smack(or have the Smack along side the Crack) since there are so many great lower impedance cans out there...


----------



## Aart

On my quest to eliminate annoying background noise, I have tried swapping output tubes. Next step is to swap driver tubes, which driver tube would you guys recommend me ? (I use a tung-sol 5998 as output tube).


----------



## tdogzthmn

Quote: 





aart said:


> On my quest to eliminate annoying background noise, I have tried swapping output tubes. Next step is to swap driver tubes, which driver tube would you guys recommend me ? (I use a tung-sol 5998 as output tube).


 


  For me the 5998 was noticeably quieter than the other tube types I tried.  The other tube I use is the E80CC which is very detailed followed by the 5814 blackplate and 6189 which I also enjoy alot.


----------



## captouch

Just ordered my kit including Speedball.

In terms of tubes, I have some 12au7's on hand to try out (Amperex Bugle Boy, Full Music that came with my EF5), but the power tubes are pricey.

It sounds like some are saying a 5998 or 421A makes a pretty big improvement, even with Speedball. However, cheapest I've seen is $80 used, and who knows how long a used tube will last.

Anyone done any comparisons between a 5998/421A and a Cetron 7236??? These are available NOS for a little over $40. I've read they're computer rated 5998A's and I've also read the 5998A's are inferior to true 5998's. Any comments would be appreciated - I don't know if I want to go down this path, but if it does make a big improvement, knowing me, it's just a matter of time before I do it.

Also, I've seen several people doing the Axon 91uF caps - it seems the effect of these are more subtle.

Roughly, does the stock Crack and Speedball get you at least 80% to the potential of the amp, or is it a no brainer, if you can afford it, to replace the power tube and caps? I don't want to chase diminishing returns, but am willing to spend some more for noticeable (not really subtle) improvements.

Thanks!


----------



## RingingEars

I did the pot and cap upgrade at the same time so I don't which one made the biggest difference, but there is a definite improvement. I dropped in a set of the AXON 91uF caps and an Alps Blue Velvet on Sat. The difference wasn't subtle at all. It really brought the mids forward.


----------



## captouch

ringingears said:


> I did the pot and cap upgrade at the same time so I don't which one made the biggest difference, but there is a definite improvement. I dropped in a set of the AXON 91uF caps and an Alps Blue Velvet on Sat. The difference wasn't subtle at all. It really brought the mids forward.




No Speedball in yet, right? I understand the role of larger caps, but would the pot improve SQ as well, or just L/R balance?

Were both upgrades very easy, or quite a bit more complicated than the base build?


----------



## Beefy

Quote: 





captouch said:


> It sounds like some are saying a 5998 or 421A makes a pretty big improvement, even with Speedball. However, cheapest I've seen is $80 used, and who knows how long a used tube will last.


 

 They do sound a bit better, but that price is ridiculous. I picked up *two* lightly used 5998 for $80 shipped when I built mine, which was pushing it - so $80 for one is downright silly.
   
  If I were you, I would do all the other easy upgrades instead, and forget the 5998 power tubes. Grab a couple of NOS RCA 6AS7 for $15 a pop and they will keep you going for years.


----------



## MilesDavis2

My crack is stock and I changed the 6080 amperex to Tungsol 5998 and there was an improvement.  Also, with the 6080, there was a subtle hum at volumes beyond 1:00.  With the 5998, the hum was gone.  Just a quiet background.  Also with the 5998, noticed that the amp was just warm not hot on the top plate.


----------



## Doc B.

I would remind everyone that the way to do mods is to first determine what it is that you want to change sonically and then figure what you need to do physically to make that happen. I admit to having gone through many hobbies, buying some new toy and then reading all I can about how to mod it. I've messed up a lot of neat stuff in the process and also made a few really neat personalized toys. The ones that came out the best were ones that I took my time on, changing one thing at a time and trying it out before I changed anything else. The worst ones were often things where I piled on every mod imaginable from the start. In that scenario you can end up with mods that work against each other and you can't determine what went wrong unless you go back to the start.
   
  The Crack is intended to be an educational journey as much as a (hopefully) enjoyable amp, and I encourage everyone to take that journey a step at a time and savor the process.


----------



## RingingEars

Quote: 





captouch said:


> No Speedball in yet, right? I understand the role of larger caps, but would the pot improve SQ as well, or just L/R balance?
> 
> Were both upgrades very easy, or quite a bit more complicated than the base build?


 


  Right. No speedball yet. Not really sure what I'm waiting for to be honest. I was going to save it for winter weekend project, but that seems pretty silly at this point.
  As far as the SQ of the pot? That's a good question that I can't really answer as I did the pot/cap install at the same time. I can tell you that the pot did make a difference in balancing the L/R at lower volumes so that's a plus.
  As far as ease of the upgrades? Yeah, they're pretty easy. The pins on the pot are kind of a PITA so I recommend you hook the wires up to the pot before install. Also you will need to dremel out the key hole on the chassis a little as the stock pot key and the Alps key do not line up.
  The caps are simple. I took a page from Beefy and installed "fly leads" when I installed the new caps. I should have done it when I first built the amp. So do like Beefy did and install them during the initial build.


----------



## RingingEars

Quote: 





doc b. said:


> I would remind everyone that the way to do mods is to first determine what it is that you want to change sonically and then figure what you need to do physically to make that happen. I admit to having gone through many hobbies, buying some new toy and then reading all I can about how to mod it. I've messed up a lot of neat stuff in the process and also made a few really neat personalized toys. The ones that came out the best were ones that I took my time on, changing one thing at a time and trying it out before I changed anything else. The worst ones were often things where I piled on every mod imaginable from the start. In that scenario you can end up with mods that work against each other and you can't determine what went wrong unless you go back to the start.
> 
> The Crack is intended to be an educational journey as much as a (hopefully) enjoyable amp, and I encourage everyone to take that journey a step at a time and savor the process.


 

 That's what's so nice about the crack Doc. It's enjoyable to build and to listen too.
  I personally feel quite a bit of satisfaction every time I look at it and know that I put it together and when I strap on the cans it just amazes me. I listen to this more than my main stereo.


----------



## captouch

Question for all those that did the Axon cap grade. . .
   
  Why 91uF?  Was there any theoretical calculation behind picking this value, or is it just the largest cap that would fit within the form factor?
   
  I'm not sure what the default/stock capacitor value is, but I'm guessing the theory behind the larger cap is to have more stored charge immediately available for fast/large transients that require a lot of energy very quickly?
   
  I'm just wondering whether this is way overkill for the application and another lower value cap (say 41uF just for example) would more than do the job.


----------



## diego

It's not for the energy stored. The cap forms a filter with the headphones and cuts off the bass. For instance, if you are using 300 ohm headphones,  you will have no bass below 5.83 hz with a 91uf cap but you'll have no bass below 12.94 hz with a 41uf cap.
   
  As a reference, I have an amplifier with a similar output stage and 66uf caps and in my opinion it has very good bass with HD 800 but almost nothing with k701s.
   
  Regards,
   
  Diego


----------



## MrDavis

Because 100uF was not available at Parts Connexion.   And because that is what Beefy did...
	

	
	
		
		

		
			




   
  100 uf  capacitors come with the kit.
  
  Quote: 





captouch said:


> Question for all those that did the Axon cap grade. . .
> 
> Why 91uF?  Was there any theoretical calculation behind picking this value, or is it just the largest cap that would fit within the form factor?
> 
> ...


----------



## captouch

Thanks guys for the education on caps. 
   
  So if the higher uF is desirable for low bass extension and 100uF already came with the kit, then what's the benefit of going with the humongously sized, but lower valued 91uF caps?
   
  Quote: 





mrdavis said:


> Because 100uF was not available at Parts Connexion.   And because that is what Beefy did...
> 
> 
> 
> ...


----------



## RingingEars

Quote: 





captouch said:


> Thanks guys for the education on caps.
> 
> So if the higher uF is desirable for low bass extension and 100uF already came with the kit, then what's the benefit of going with the humongously sized, but lower valued 91uF caps?


 
  The size difference stems from the different materials used in the caps. The stock caps are electrolytic where as the AXON (or others brands everyone is using) are film caps. I couldn't tell you the science behind it, but evidently it takes more of the film than the electrolytic to reach equal values ie: microfarad and/or voltage.


----------



## Doc B.

Quote: 





diego said:


> As a reference, I have an amplifier with a similar output stage and 66uf caps and in my opinion it has very good bass with HD 800 but almost nothing with k701s.
> 
> Regards,
> 
> Diego


 
  This is dependent upon the operating point as well as the cap value, since the op point determines the output impedance of the amp. As an experiment we just doubled the current through the 6080 in our lab Crack in order to lower the output impedance and we got quite nice bass with K701s. Before everyone jumps on this mod - we are letting it run for a while to see if the semiconductor devices and heat sinks we use in the active loads can handle the additional power dissipation.


----------



## Beefy

Quote: 





doc b. said:


> Before everyone jumps on this mod - we are letting it run for a while to see if the semiconductor devices and heat sinks we use in the active loads can handle the additional power dissipation.


 
   
  Must be pretty tough on the transformer as well?


----------



## RingingEars

I know it's already been done, but here's a pic of the cap/pot mod I did to mine.


----------



## captouch

Looks nice RingingEars. 
   
  You still have the Speedball to go, right?  Anything else planned?
   
  You may have said before, but what tubes are you using?


----------



## RingingEars

Quote: 





captouch said:


> Looks nice RingingEars.
> 
> You still have the Speedball to go, right?  Anything else planned?
> 
> You may have said before, but what tubes are you using?


 

 Yeah. Still need to do the speedball. Other upgrades will include a Neutrik locking jack, RCA jacks, bypass cap or choke, maybe a jewel light indicator. I would like to get the PCB style sockets too, but we'll see. I would also like to rewire the whole thing. My wiring is kind of helter-skelter.
  I'm using an NOS RCA 6AS7G that I found cheap on that auction site and the original 12AU7 that  came with the amp. I'll probably start rolling others here soon.


----------



## ShibaInu

Off-topic, but where can one go to test tubes to verify they're good before putting them into the Crack?  I'm in Bay Area, CA (San Jose).  Radio Shack doesn't have tube testers, do they?


----------



## Doc B.

Quote: 





beefy said:


> Must be pretty tough on the transformer as well?


 

 The transformer can handle it fine. PJ estimates a heat rise to maybe 105C and the trans is rated to 155C. The only thing that might be marginal is the capacity of heat sinks on the TIP50s in the Speedball. We'll probably redesign that PC board for a bigger heat sink if this works out.


----------



## RingingEars

Quote: 





shibainu said:


> Off-topic, but where can one go to test tubes to verify they're good before putting them into the Crack?  I'm in Bay Area, CA (San Jose).  Radio Shack doesn't have tube testers, do they?


 


  No they don't. Your best bet is to just buy tubes from a reputable dealer or maybe find a tube tech or TV repair guy in the area that has a tester.


----------



## Doc B.

For years I have maintained that the very best tube tester is the device you want to run the tube in. A good sounding tube can test poorly in a drug store tester and a great testing tube can sound lousy in an amp. All a tube tester will tell you is how the tube is working at the operating point that has been preset in the tester, which may not be the same as the amp you want to use it in. And you won't be able to test for noise. Unless the tube is smashed or otherwise badly shorted you're not going to hurt the Crack by putting it in there, measuring the voltages to see if they fall reasonably within spec and then listening for noise or imbalance.


----------



## ShibaInu

Quote: 





doc b. said:


> For years I have maintained that the very best tube tester is the device you want to run the tube in. A good sounding tube can test poorly in a drug store tester and a great testing tube can sound lousy in an amp. All a tube tester will tell you is how the tube is working at the operating point that has been preset in the tester, which may not be the same as the amp you want to use it in. And you won't be able to test for noise. Unless the tube is smashed or otherwise badly shorted you're not going to hurt the Crack by putting it in there, measuring the voltages to see if they fall reasonably within spec and then listening for noise or imbalance.


 

 Thanks Doc, great to know.  I wasn't so concerned about the remaining life as measured on a tester, but more to verify the tubes weren't damaged before putting it into the Crack (to avoid damage to the Crack).
   
  Is a shorted tube something you can measure with a multi-meter prior to insertion, or is there some other visible indication of a bad short (I know I can visually identify a smashed tube, but wondering about the bad short case).


----------



## Draygonn

Ok guys, you peaked my interest in this fun DIY project. I ordered a speedballed crack today. Can't wait to start putting it together. Now I gottta go find a soldering kit...


----------



## RingingEars

^^Nice. Try to find a decent soldering station with variable temp. It makes soldering so much easier.


----------



## BmWr75

I have a Weller soldering station with variable temperature.  Built a Crack -w- Speedball using it.  However, I have always run the Weller station on maximum temperature.  How does one figure out when to use an appropriate lower temperature setting?


----------



## RingingEars

Quote: 





bmwr75 said:


> I have a Weller soldering station with variable temperature.  Built a Crack -w- Speedball using it.  However, I have always run the Weller station on maximum temperature.  How does one figure out when to use an appropriate lower temperature setting?


 

 When I first started I just read as much as I could on soldering equipment and techniques. I set mine around 650F for soldering duty and 725F or so for desoldering. I've never really veered from that for fear of burning something up. I know when I put the Crack together I was sweating bullets when it came time to solder those little LEDs.


----------



## Doc B.

Re tube shorts:
   
  Unfortunately some tube shorts don't conduct until they get hit with a high potential, so you might find a short, or you might not when using a
  DMM on the tubes pins. So I should temper my initial comment to say that the tube tester can be useful to find shorts, but honestly I don't run across tubes that are shorted badly enough to arc and cause damage more than once in a very great while and a minor short is probably not going to hurt anything, you will just hear it when you check the output noise.
   
  Re soldering temp:
   
  One day I was sitting around with a few other old solder jockeys. We had all been building our own gear and doing repairs for years and a couple of the guys had been to the Navy soldering school. The discussion of tip temp came up. We all admitted to using our stations with the knob dialed to max. The temp you use has a lot to do with technique. Once you have a feel for how the iron works the best way to get the job done is to heat the joint as quickly possible to avoid prolonged exposure of the neighboring parts to the heat. This takes a lot of practice, like building a point to point wired amp kit can give you.
   
  Re the LEDs:
   
  The size of the tip is the critical issue. For the point to point wiring to terminal strips a 1/16" chisel tip works well as it has enough surface area to contact both the wire and the terminal to heat them. For PC board work and for soldering tiny parts like those HP LEDs I like a very fine pencil tip or perhaps better yet one of the tips that I think one might call a "mechanical pencil tip" - it tapers to a skinny rod with a bologna slice at the end, and for the really delicate stuff like the LEDs you can turn the tip temp down to 650 F or a bit lower.


----------



## RingingEars

Doc. I also used a heatsink on the LEDs just to go the extra mile. They had me a little nervous.
	

	
	
		
		

		
		
	


	



  I used to build fan buses for my computers back in the late 90's(this was before you could buy them) with a cheap rad shack soldering gun. I was never really all that confident in my soldering skills, but the station really helped my confidence level during the crack build and made it a truly, super enjoyable project. Now that I have under my belt, I'll try using max temp on the next one. Do you run it that high on the PC boards ie: speedball, as well?


----------



## Doc B.

Yeah, I do, but on the other hand tech Shawn turns the temp down a bit. It's really just a matter of developing your own style. Shawn prefers to use a Hakko 936 and doesn't really like to change tips, and I spent years with a Hexacon Thermo-O-Trac I inherited from one of those other old solder jockeys and switch tips for different jobs. They have a little bit different feel to them and the recovery time is a little different, and we had each gotten used to using either, but kept our preference. I like to have choices for different jobs so I also keep a little 15 watt iron around for really delicate stuff and a pretty big old Ungar iron for massive stuff like all metal speaker posts. The Hexacon broke recently and I just bought an Ersa 2000A to replace it, as the Hexacon replacement parts are uber expensive for what they are. Still getting used to the Ersa, it's like getting a new pair of shoes.


----------



## RingingEars

You know, using the cheap rad shack unit with the pencil tip for so many years and then recently watching you-tube videos on proper soldering techniques I couldn't understand why the pros favored using the chisel style tips so much. To me they looked cumbersome, but when I started to build the crack, and especially doing the cap upgrades, it all started to make sense to me. You got to heat a larger area quickly that a pencil tip just won't do. I found myself using the side of the tip quite a bit. I think I'll pick up a chisel tip for my next go-round...


----------



## Doc B.

Here's a couple of ideas for Hakko 936, 937, etc. users.
   
  For PC board work
   

   
http://www.all-spec.com/products/Plato/Soldering_and_Rework|Replacement_Tips%5E_Electrodes_and_Cartridges|TIP-07/HS-5702.html
   
  for PTP wiring:
   

http://www.all-spec.com/products/Plato/Soldering_and_Rework|Replacement_Tips%5E_Electrodes_and_Cartridges|TIP-01/HS-2751.html
   

 One can probably find similar types for Weller, Pace, Hexacon, Edsyn, etc. from Plato.


----------



## BmWr75

Actually, I did use a cheap low power iron with a pencil tip (instead of the Weller unit) for the fine soldering work on this kit.  Forgot this until you mentioned it.  I later order some more different size tips for the Weller unit.


----------



## captouch

My kit is arriving today.
   
  I have a Hakko 454 soldering iron (25W, 842C) and Kester Silver Solder (62% tin, 36% lead, 2% silver) - no replaceable tips.  This temp sounds a little hotter than what others have advised using and this is just a pointy tip (no chisel tip option).
   
  Does these sound like they'll do the job fine, or am I asking for trouble using what I have and be better advised to get an adjustable temp, replaceable tip iron?
   
  Very novice soldering skills, btw.  I'll be checking youtube videos for technique.


----------



## Doc B.

I'm not familiar with the 454. 850 degrees is a pretty standard max temp for solder stations, but I usually recommend a 40W iron or higher power rating for the point to point work on the terminal strips.


----------



## MilesDavis2

Tonight, using my stock crack with tungsol 5998 and electro harmonix 12au7. Used the dt880 600 ohm and listened to Bill Evans, Keith Jarrett then switched to Janis Joplin, Nina Simone, and finished with Joe Bonamassa;s "Sloe Gin". This amp is built like an american muscle car. Wow! It has alot of reserve power. Requesting for advice with regards on the speedball upgrade. Would there be a noticeable difference other than the joy I;m having tonight? Would appreciate input on this.


----------



## Beefy

Quote: 





milesdavis2 said:


> Requesting for advice with regards on the speedball upgrade. Would there be a noticeable difference other than the joy I;m having tonight? Would appreciate input on this.


 
   

Plenty of discussion of that over the last few pages. Many - including myself - consider the Speedball the single best upgrade that you can do.​


----------



## MilesDavis2

Thank you.
  Quote: 





beefy said:


> Plenty of discussion of that over the last few pages. Many - including myself - consider the Speedball the single best upgrade that you can do.​


----------



## captouch

Received some Tung Sol 5998's for my yet-to-be-built Crack.  Man, these tubes are really beautiful.  Can't wait to hear how they sound!


----------



## Magedark

One day, in the future, I will make a Crack. It's at the top of next DIY stuff and I'll run it through my now-incoming K500.


----------



## captouch

I just built my Crack and had a question: For those of you using DT880/600's, where's the volume knob typically for you at reasonable (not very loud) listening levels?  Mine's around 1:00-3:00 - which seemed high to me - just wondering if that's typical.  Thanks.


----------



## Armaegis

Mine's usually at 12 o'clock, but I don't listen at high volumes unless I'm testing.


----------



## Doc B.

Where the knob is set has to do with the sensitivity of the headphones and also the output level of your source. So it's rather difficult to make comparisons unless you are comparing setups with the same source level as well as the same headphones. As long as you can go a bit louder than you need before running out of room to turn the knob you are OK.


----------



## BmWr75

I listen to my Crack with DT770/600s mainly.  Volume is set pretty much in the same range as yours.  I can't listen to them turned all the way up......so what Doc B. said works for me.


----------



## MilesDavis2

Mine is set comfortably with power at 11:00.  This is on the DT880.  Great amp.


----------



## captouch

Thanks all for the volume level feedback.
   
  Now to roll some tubes. . .Speedball upgrade to be built and installed later after I have some time with the stock unit.  Not to mention. . .I've had my fill of soldering and wire-stripping for awhile. . .


----------



## captouch

doc b. said:


> Where the knob is set has to do with the sensitivity of the headphones and also the output level of your source. So it's rather difficult to make comparisons unless you are comparing setups with the same source level as well as the same headphones. As long as you can go a bit louder than you need before running out of room to turn the knob you are OK.




Very true as I found out this evening. I had been using a line out cable from a 1st gen iPod Touch when I had to turn up to 1:00-3:00. I assumed that using line out would give me a strong signal. But using the fixed output of a NFB-12 DAC resulted in much higher volume with the same headphones. Now 9:00-11:00 is more than enough - so source level is very much a factor as you said Doc. More than enough juice for my needs.

Still sticking with stock tubes at the moment, and haven't done any comparisons with my other amp yet. Have both a Tung Sol 5998 and a RCA 12BH7 that came from a McIntosh amp to try out later.


----------



## sennheiserhd485

Quote: 





tdogzthmn said:


> I fully agree that a threesome review of these amps is a must. I would be more than willing to do such a review but it will take some time for me to get all three in my possession. I would also say the HD600 would make a good can to use due its popularity and that most of these amps were built using the HD600 as a reference point.


 


 In your opinion, would the HD600 sound best with the Crack, or a SS Dynalo? I like a lively sound, but with neutral bass.


----------



## Doc B.

We will have all three amps in their latest iterations at RMAF next week, lined up together and playing from the same source. And of course they will all be available for audition at Bottleheadquarters after the show.


----------



## MilesDavis2

Quote: 





sennheiserhd485 said:


> In your opinion, would the HD600 sound best with the Crack, or a SS Dynalo? I like a lively sound, but with neutral bass.


 


 I am using HD600 and the DT880 600ohm...I also like a lively sound with neutral bass.  The crack fills that.  I have not used the ss dynalo but can only speak for the crack.  My crack is stock and am very pleased with it.  Hope this helps.


----------



## Armaegis

Quote: 





sennheiserhd485 said:


> In your opinion, would the HD600 sound best with the Crack, or a SS Dynalo? I like a lively sound, but with neutral bass.


 

 I brought the Crack to a meet the other week and a guy had his HD600 plugged into it for a while. Out of the various amps there, the Crack was the only one that made him say "how much?"...
   
... followed immediately by "no wait, don't tell me, the wife will kill me if I buy any more..."


----------



## captouch

Quote: 





milesdavis2 said:


> I am using HD600 and the DT880 600ohm...I also like a lively sound with neutral bass.  The crack fills that.  I have not used the ss dynalo but can only speak for the crack.  My crack is stock and am very pleased with it.  Hope this helps.


 

 I was thinking of picking up a 2nd set of headphones and have the DT880/600 now.  Do you think the HD600 makes a good alternative headphone to complement the 880's?  I'd like to stick with two cans only (for now).  I was thinking HD650 might be more of a contrast, but heard the HD600 sounds great as well.


----------



## MilesDavis2

Quote: 





captouch said:


> I was thinking of picking up a 2nd set of headphones and have the DT880/600 now.  Do you think the HD600 makes a good alternative headphone to complement the 880's?  I'd like to stick with two cans only (for now).  I was thinking HD650 might be more of a contrast, but heard the HD600 sounds great as well.


 


 I have not heard the HD65o but I am glad that I have the HD600.  I would suggest that you do add a HD600 as a second set as they truly have their own different sound flavors.  I like using the DT880 for classical and solo piano and guitar music. Detailed music where you could hear each movement of the fingers on the string.  I use the HD600 for rock, fusion, and blues. Not that the HD600 won't make you smile with classical and solo instrumentation. I am confirsent that you would be happy with the two phones.
   
  Now of course, we're talking about using them on the crack as I've used them on other amps but it just doesn't move me like the crack does.  And again, my crack is stock.  I will of course still elevate to the speedball but right now, I am fine and contented.  Hope this helps in some way.


----------



## captouch

Thanks MD2 - will keep my eyes open for a deal on HD600's.

Does the Crack require much in the way of burn-in? It already seems to sound a bit better than yesterday, but could be my imagination. 

Also, had a heck of a time getting the tubes in initially. Was wondering if my lack of soldering skills caused a problem, but eventually got them in. Do the sockets loosen with time?


----------



## MilesDavis2

Quote: 





captouch said:


> Thanks MD2 - will keep my eyes open for a deal on HD600's.
> 
> Does the Crack require much in the way of burn-in? It already seems to sound a bit better than yesterday, but could be my imagination.
> 
> Also, had a heck of a time getting the tubes in initially. Was wondering if my lack of soldering skills caused a problem, but eventually got them in. Do the sockets loosen with time?


 


 When you spot one that's practically new...go for it.
   
  I've got abot 30 hours on mine and each listening session gets better. Think the tungsol 5998 also has something to do with it. Not your imagination...it does get better.
   
  It will loosen as you roll tubes. Enjoy the amp...It is a good amp with a great value.


----------



## sennheiserhd485

So, I guess it's a no-go on the Crack and the HD600?
   
  I wouldn't be using a Gilmore Lite. I would be using the Sheer Audio HA-006++.
   
  I assume that they are the same?


----------



## captouch

sennheiserhd485 said:


> So, I guess it's a no-go on the Crack and the HD600?
> 
> I wouldn't be using a Gilmore Lite. I would be using the Sheer Audio HA-006++.
> 
> I assume that they are the same?




Why do you say "no-go"? People have said it's a great match.


----------



## MilesDavis2

Quote: 





sennheiserhd485 said:


> So, I guess it's a no-go on the Crack and the HD600?
> 
> I wouldn't be using a Gilmore Lite. I would be using the Sheer Audio HA-006++.
> 
> I assume that they are the same?


 


 It's a go, 485


----------



## MilesDavis2

Tonight. the crack is poweing the DT880 and listening to Bill Evans - Complete Village Vanguard recordings 1961.


----------



## sennheiserhd485

Quote: 





captouch said:


> Why do you say "no-go"? People have said it's a great match.


 


 Sorry, I didn't see those posts at first. I guess it is a split decision over the two amps.


----------



## sennheiserhd485

Quote: 





milesdavis2 said:


> Tonight. the crack is poweing the DT880 and listening to Bill Evans - Complete Village Vanguard recordings 1961.


 


  Wow, I really like the look of this one. How long did it take you to build it?


----------



## MilesDavis2

Quote: 





sennheiserhd485 said:


> Wow, I really like the look of this one. How long did it take you to build it?


 


 Didn't build it.  The seller practiced in putting it together  for his next bottlehead project.  Sold it for cost. That's why the next thing is the speedball upgrade.  Beautifully put together though.


----------



## sennheiserhd485

Quote: 





milesdavis2 said:


> Didn't build it.  The seller practiced in putting it together  for his next bottlehead project.  Sold it for cost. That's why the next thing is the speedball upgrade.  Beautifully put together though.


 


 If I buy a Crack, I would have to spend around $500 on it. I am not brave enough to build it myself.
   
  I am concerned over whether it is still a good value if I spend that much on it.
   
  There are possibly some other tube amps for $500 that might be better, right?


----------



## Armaegis

Plenty of guys around here who'd be willing to build you one for relatively cheap...


----------



## MilesDavis2

Quote: 





sennheiserhd485 said:


> If I buy a Crack, I would have to spend around $500 on it. I am not brave enough to build it myself.
> 
> I am concerned over whether it is still a good value if I spend that much on it.
> 
> There are possibly some other tube amps for $500 that might be better, right?


 


 The $500 would include the speedball upgrade.  I was going that route until I found the crack on audiogon for cost.  Just lucked out. I was ready to order from bottlehead complete with the upgrades and assembly.  Even at $500, believe me...its still is good value.


----------



## captouch

Quote: 





sennheiserhd485 said:


> If I buy a Crack, I would have to spend around $500 on it. I am not brave enough to build it myself.
> 
> I am concerned over whether it is still a good value if I spend that much on it.
> 
> There are possibly some other tube amps for $500 that might be better, right?


 
   
  The kit itself sounds very nice stock and is normally $219 + shipping w/o Speedball upgrade.  I didn't see this mentioned here, but Bottlehead is giving a automatic 5% discount for Crack _*+ Speedball*_ orders through Sunday, and IF enough people (only 6 more at this point) order by Sunday night, they're giving other 10% off for a total of 15% off (so $270 + shipping instead of $318 + shipping).  If anyone is thinking about this amp for their high impedance cans, I'd jump on this deal.
   
  I built it myself over the course of 1 day (off and on - took breaks, went out with family for lunch and shopping).  I had very, very little soldering/DIY experience.  I watched a couple of soldering videos on YouTube (which made me realize I'd been doing it wrong in the past).  But I got everything right the first time by taking it slow and checking connection integrity after virtually every soldering step to make sure I made a good solder joint (I really didn't want to debug later).  It probably took me 8hrs of actual labor, taking it slow.  This doesn't include painting the top or staining the bottom (which I haven't done yet).  But it was mostly enjoyable (I was tired near the end of the day and pushed myself to finish, but that was my impatience to wrap it up before the workweek started).
   
  The hardest part for me was sometimes you had 3 connections going through one point.  In a couple of cases, I "attached and soldered" when I should have just "attached" and soldered later when the other wires were in place (my bad for not noticing this in the instructions).  And the heat travels fast from the iron along the lead to the component, so I was always a bit worried about leaving the iron there too long and frying a component - but it all turned out fine.  Also, there was one case where the full length of the resistor provided was too short to span the connection points, requiring that I bend the connection points closer to enable the resistor to be connected - that was a bit of a pain, but I made due.
   
  Point is, I was also pretty hesitant to build it, but if you get the right tools (iron, wire stripper, needle nose pliers, etc), it's not so bad.  It does take awhile, but overall not too difficult even for a beginner like me.


----------



## MrDavis

Indeed. Very easy to build.  Just take your time and follow the excellent instructions.


----------



## sennheiserhd485

Quote: 





captouch said:


> The kit itself sounds very nice stock and is normally $219 + shipping w/o Speedball upgrade.  I didn't see this mentioned here, but Bottlehead is giving a automatic 5% discount for Crack _*+ Speedball*_ orders through Sunday, and IF enough people (only 6 more at this point) order by Sunday night, they're giving other 10% off for a total of 15% off (so $270 + shipping instead of $318 + shipping).  If anyone is thinking about this amp for their high impedance cans, I'd jump on this deal.
> 
> I built it myself over the course of 1 day (off and on - took breaks, went out with family for lunch and shopping).  I had very, very little soldering/DIY experience.  I watched a couple of soldering videos on YouTube (which made me realize I'd been doing it wrong in the past).  But I got everything right the first time by taking it slow and checking connection integrity after virtually every soldering step to make sure I made a good solder joint (I really didn't want to debug later).  It probably took me 8hrs of actual labor, taking it slow.  This doesn't include painting the top or staining the bottom (which I haven't done yet).  But it was mostly enjoyable (I was tired near the end of the day and pushed myself to finish, but that was my impatience to wrap it up before the workweek started).
> 
> ...


 


 Wow. Okay, I hope enough people order by Sunday. I should probably go ahead and order mine.
   
  You have give me some _very_ good information about the build, but I still feel like I could ruin the whole thing.
   
  What kind of return policy do they have? Would they give me back my money if I did something horribly wrong?


----------



## captouch

sennheiserhd485 said:


> Wow. Okay, I hope enough people order by Sunday. I should probably go ahead and order mine.
> 
> You have give me some _very_ good information about the build, but I still feel like I could ruin the whole thing.
> 
> What kind of return policy do they have? Would they give me back my money if I did something horribly wrong?




I don't think they would give a refund if you messed it up, but I think they might replace individual components that were accidentally damaged. If you check your connections along the way, you can probably tell if you're veering off track. For example, if point A was connected/soldered via wire to point B and point B to point C, then if you checked resistance from A to C and you're solidly connected (0 ohms), you've probably made good connections from A to B and B to C.

I have to admit I did the w/o power resistance checks after the build was complete, but after that was confirmed okay and once I powered up and saw the tubes glowed properly, I just plugged in cheap sacrificial earbuds and checked if I got sound, which I did. I really didn't want to poke around in a live powered device and chose to risk blowing a cheap pair of buds rather than do the final voltage verification.

Anyway, watch some YouTube videos on soldering if that's what you're most uncomfortable with. Honestly, if you can solder, you should be fine. If you haven't before, you can always buy some piece parts from radio shack that are similar to the components in the kit and practice on those first.

What's telling to me is I haven't seen a single post of someone saying they messed the whole thing up beyond repair. People get cold solder joints or have to debug a build sometimes, but I think the Bottlehead folks and forum members are pretty readily available to help.


----------



## Timbeh

i tried to make account for bottlehead forums 3 days ago, and got one email asking why i want the account. i replied, but i think if it´s so hard i rather skip this one.


----------



## MilesDavis2

Quote: 





timbeh said:


> i tried to make account for bottlehead forums 3 days ago, and got one email asking why i want the account. i replied, but i think if it´s so hard i rather skip this one.


 


 That happened to me. They're just filtering spammers. Try again. It is such a good amp to turn away for a simple forum question. I used my crack again last night and it validated the fact that it is such a GOOD AMP!


----------



## Doc B.

Yes, one of the moderators of the Bottlehead Forum contacts registrants individually simply to keep out spammers. We will be updating the website, including the forum, in the near future and the registration process will be more automated in the newer version. To give you an idea of the scope of the spammer problem, I installed the new automated anti spam registration software on another forum I host, that gets about 80% of the traffic of the Bottlehead Forum. In the past couple of weeks it has weeded out pretty close to 5000 spammers. That's just one little ol' website that gets maybe a quarter million page views a month. Multiply that by the number of forums on the web - I think there might be countries whose entire economic subsistence is based upon meatbot forum spamming for hire.
   
  The response to the offer has been great, we are just a couple orders away from hitting the goal already with almost three full days left. So I think that one can order with the confidence that the deepest discount offered will be credited to your account.


----------



## Timbeh

Thanks for the response, Doc. And i didn´t mean to be impatient, i´m working in IT and i know that spam is serious problem all over, in fact over 90% of our corporations emails are spam. And btw, got my ACC activated, say my thanks to your admin


----------



## lextek

Just placed my order for my Crack fix! Birthday present to myself. I'm. Really excited to get this amp. Planning on moving the AC cord and inputs to the rear panel. Probably leave the volume knob and headphone jack on top for now


----------



## sennheiserhd485

Does the Crack have a stepped attenuator?


----------



## lextek

sennheiserhd485 said:


> Does the Crack have a stepped attenuator?



As far as I know. No. That is the stock kit.


----------



## sennheiserhd485

Quote: 





lextek said:


> As far as I know. No. That is the stock kit.


 


 I can't get past the idea of channel volume imbalance. A stepped attenuator is the only fix, right?


----------



## Armaegis

Almost all pots will have a slight imbalance at the lowest volumes, but will balance out at normal listening levels. If you're really picky, then you can order a bunch of pots and test each one with a multimeter and pick the best one. Or you could use a separate mono pot for each channel and control them separately.


----------



## jjinh

Finally started to do some work on my Crack amp... after putting it off for like a year, but it should be finished soon


----------



## Beefy

Quote: 





sennheiserhd485 said:


> I can't get past the idea of channel volume imbalance. A stepped attenuator is the only fix, right?


 

  
http://www.partsconnexion.com/tkd_64187.html <- I can strongly recommend this as an upgrade to the included pot. Considerably better than the Alps Blue pot in most commercial amps as well.


----------



## captouch

beefy said:


> http://www.partsconnexion.com/tkd_64187.html <- I can strongly recommend this as an upgrade to the included pot. Considerably better than the Alps Blue pot in most commercial amps as well.




Was it really night and day difference between stock pot and this one? $100 is a lot to spend on volume control and I haven't heard any channel imbalance yet. Where would you rank this on the list of upgrades you'd recommend making? Thanks.


----------



## sennheiserhd485

Quote: 





captouch said:


> Was it really night and day difference between stock pot and this one? $100 is a lot to spend on volume control and I haven't heard any channel imbalance yet. Where would you rank this on the list of upgrades you'd recommend making? Thanks.


 


 +1


----------



## BmWr75

Quote: 





captouch said:


> Was it really night and day difference between stock pot and this one? $100 is a lot to spend on volume control and I haven't heard any channel imbalance yet. Where would you rank this on the list of upgrades you'd recommend making? Thanks.


 


  +2
   
  I don't hear any channel imbalance in my Crack either using the stock volume pot.  A $100 volume control upgrade in an amp kit that costs $219 better make a huge sonic difference.


----------



## sennheiserhd485

Does anyone know how many mW a Crack puts out?
   
  I am not sure if it can drive the HD 600 to its *full* potential.


----------



## MilesDavis2

Quote: 





sennheiserhd485 said:


> Does anyone know how many mW a Crack puts out?
> 
> I am not sure if it can drive the HD 600 to its *full* potential.


 


 It drives my DT880 600Ohm to it's full potential with alot more to give on demand. It will drive your HD600 like it was just training day.


----------



## Armaegis

My first crack had only minor imbalance at the lowest levels. My second had a very serious imbalance to the point where one side didn't even attenuate fully (though at normal listening it was balanced); but Doc had a new pot sent out to me.
   

  
  Quote: 





sennheiserhd485 said:


> Does anyone know how many mW a Crack puts out?
> 
> I am not sure if it can drive the HD 600 to its *full* potential.


 

  
  I've driven an HD600, HD650, the Beyers in every single impedance rating, and my 600 ohm Sextetts, all with ample headroom to spare.


----------



## Timbeh

Do you know do they work at the weekend? Eileen was very helpful and promised me shipping fee to overseas combined with crack / speedball so that i can make my order, but i´m thinking should i make the order from website already, just to make sure i dont miss the price reduction


----------



## Beefy

Quote: 





captouch said:


> Was it really night and day difference between stock pot and this one? $100 is a lot to spend on volume control and I haven't heard any channel imbalance yet. Where would you rank this on the list of upgrades you'd recommend making? Thanks.


 
   
  Speedball first, but I would upgrade the pot before I bothered upgrading the output caps.
   
  Quote: 





bmwr75 said:


> I don't hear any channel imbalance in my Crack either using the stock volume pot.  A $100 volume control upgrade in an amp kit that costs $219 better make a huge sonic difference.


 

 Yeah, I wouldn't put one in a stock Crack. But if you are going balls to the wall with Speeball, output caps, 5998 tubes, etc. etc. then the $100 for an excellent pot makes a lot more sense.
   
  In all fairness, I didn't realise the pot was now $100. They used to be $72, and I picked mine up during PCX's 20% off sale. Absolute no brainer for the ~$58 I paid.


----------



## Tegmentum

I've really been wanting to try one of these. Heard a S.E.X. and it was quite good sounding the HD600s and so I'm imagining the Crack, as a dedicated headphone amp, will be the one to have.


----------



## BmWr75

Quote: 





tegmentum said:


> .......so I'm imagining the Crack, as a dedicated headphone amp, will be the one to have.


 


  Depends on your headphones.  The Crack is only compatible with higher impedance cans.  The Sex works with all impedances since it uses output transformers.


----------



## BmWr75

Quote: 





beefy said:


> Speedball first, but I would upgrade the pot before I bothered upgrading the output caps.
> 
> Yeah, I wouldn't put one in a stock Crack. But if you are going balls to the wall with Speeball, output caps, 5998 tubes, etc. etc. then the $100 for an excellent pot makes a lot more sense.
> 
> In all fairness, I didn't realise the pot was now $100. They used to be $72, and I picked mine up during PCX's 20% off sale. Absolute no brainer for the ~$58 I paid.


 

 Agree, after all those upgrades, a new volume pot is not out off line..  I've done the Speedball, but didn't install fly leads.  So, doing the cap upgrade would be more difficult.


----------



## Project22a

Quote: 





sennheiserhd485 said:


> Does anyone know how many mW a Crack puts out?
> 
> I am not sure if it can drive the HD 600 to its *full* potential.


 


  Seconded. A bit superficial of me, but I like seeing numbers. What's the power output @ 300ohms?


----------



## igotyofire

I have had this kit sitting for a year now......finally started the wiring up today because a buddy motivated me to finish this project & offered assistance. Hopefully the rest will be done tomorrow.
   
   
   

   
   

   

  all going in this finish


----------



## roadcykler

Quote: 





project22a said:


> Seconded. A bit superficial of me, but I like seeing numbers. What's the power output @ 300ohms?


 

  
  From the Bottlehead website, "max output about 10V into a 300 ohm load." I bet if you e-mailed them they'd tell you the milliwatts.


----------



## jjinh

Quote: 





igotyofire said:


> I have had this kit sitting for a year now......finally started the wiring up today because a buddy motivated me to finish this project & offered assistance. Hopefully the rest will be done tomorrow.


 
   
  Hey, I've also had my kit for >1 year! I'm just lazy but I had an hour to spare so I soldered in all that stuff there in the pic below.


----------



## Armaegis

Quote: 





roadcykler said:


> From the Bottlehead website, "max output about 10V into a 300 ohm load." I bet if you e-mailed them they'd tell you the milliwatts.


 


  P = V^2/R, or roughly a third a watt in this case.


----------



## sennheiserhd485

Quote: 





armaegis said:


> P = V^2/R, or roughly a third a watt in this case.


 


 Ick. So, 333 mW?


----------



## igotyofire

Quote: 





jjinh said:


> Hey, I've also had my kit for >1 year! I'm just lazy but I had an hour to spare so I soldered in all that stuff there in the pic below.


 


  Good luck bro! I just finished mine tonight & unless you have some better amp's lying around you will be kicking yourself for waiting so long for your fix! This thing is sweet & is only the 2nd amp I have built(CMOY first for experience). I did all the soldering & my buddy cut up all the wires for me. Only had 1 cold solder join with the LED's that was probably the one of the hardest parts since everything was so tiny. Everything voltage tested perfectly fine with various amounts off to small percentages. Now I was ready to throw my HD600's away as my Maverick D1 wasn't doing them any justice. My 600ohm Dt880's far exceeded them & the HD600s sounded far better on Ray Samaual's premier amp on a balanced setup that I once heard which was the whole reason i purchased the HD600s. Well the Crack amp & the HD600s was a match made in heaven. It makes the DT880's almost seem useless in certain circumstances in the very short amount of listening Ive done. Ofcourse its all genre specific but I will have to do some more listening & critique after I can get some more time in!  So thats my two cents for now! Here is the finished product below


----------



## captouch

Pictures of my recent build. . .
   
  Underside, currently stock.

   
   
  Top looks black, but isn't really.  It's Rustoleum Universal Metallic Oil-Rubbed Bronze.  Pretty easy to apply - satisfied with that.  A little sparkly at the right angles.
   

   
  With tubes: Tung Sol 5998 and Amperex Bugle Boy 12AU7.  Have the stock '72 Sylvania 6080 that shipped with the unit, as well as the stock Electro Harmonix 12AU7, plus another Amperex Voice of Music 12AU7 as well as a McIntosh by RCA 12BH7 tube, which I haven't tried yet.  
   

   
  Not really satisfied with the wood finish.  Would try wood conditioner next time to smooth out the staining, and tape the edges where the glue could overflow and touch since that affects stain absorption.  Used Varithane stain (red chestnut) and glossy polyurethane finish.  It was hard to tell how much poly finish was going on with the spray - would get liquid next time and apply with brush.
   
  Speedball will be added later.  No plans for other upgrades or tubes at the moment.
   
  Sounds really great with DT880/600's on most tracks - some sound a little trebly/harsh (due to recording).  May pick up some HD600's to smooth out those harsher recordings.
   
  Very happy so far with amp.  Haven't done a huge amount of comparative listening against my HiFiMan EF5 - both sound really good, but I do think there are some differences.  Just haven't had time to do a really good comparison yet.


----------



## captouch

Quiet here.  Haven't some of the group buy people received their kits yet?  Looking forward to hearing other people's feedback and experiences.


----------



## tdogzthmn

It's quiet because we are all too busy listening to sweet sounding music!


----------



## Timbeh

I hope they will ship my order soon, then there´s still the delivery time to Finland


----------



## Doc B.

Hi folks,
   
  We've been at the Rocky Mountain Audiofest over the weekend and we're just getting back to work today. Shipping Cracks from the recent sale is a priority and we should see lots of them going out over the next few days. Here's one Crack related comment from the show, courtesy of Tyll Hertsens:
   
http://www.innerfidelity.com/content/canjam-rmaf-2011-bottlehead


----------



## kongmw

seriously thinking of ordering my Crack. in fact the only thing holding me back right now is that i have no experience finishing wood case and aluminum plate. 
   
  any suggestions on how i should go about finishing the surfaces? i've read the first 20 or so pages in this thread...


----------



## Doc B.

The chassis panel really needs no finish. The transformer end bell is raw steel and it will benefit from a spray of some kind of clear coat if you don't want to spray paint it with a color coat. As for the base, it's really easy. It just glues together with wood glue like a picture frame, using a few strips of masking tape. Just be sure to clean off any excess glue that squeezes out and let it dry. Sand it with 220 grit paper and then you can either stain it and then clear coat it when dry, or do like we do and just put on a clear urethane finish. I prefer aniline dye if it needs to be stained, but a good quality wood stain will work fine. I know some folks like the one step stain and finish products, but I have never found them to be very satisfactory. Varathane makes good clear finishes in both oil and water based versions. The oil based version will bring out more of the grain, the water based version will keep the wood grain looking more like it does when unfinished.


----------



## kongmw

Quote: 





doc b. said:


> The chassis panel really needs no finish. The transformer end bell is raw steel and it will benefit from a spray of some kind of clear coat if you don't want to spray paint it with a color coat. As for the base, it's really easy. It just glues together with wood glue like a picture frame, using a few strips of masking tape. Just be sure to clean off any excess glue that squeezes out and let it dry. Sand it with 220 grit paper and then you can either stain it and then clear coat it when dry, or do like we do and just put on a clear urethane finish. I prefer aniline dye if it needs to be stained, but a good quality wood stain will work fine. I know some folks like the one step stain and finish products, but I have never found them to be very satisfactory. Varathane makes good clear finishes in both oil and water based versions. The oil based version will bring out more of the grain, the water based version will keep the wood grain looking more like it does when unfinished.


 


  Thanks Doc! Now other than the initial sanding with 220 grit paper, is there additional sanding required between the polyurethane coats? I might just forego the staining part this time to minimize my chance of messing it up entirely. Although I'm still thinking of spray-painting the panel so it's not bare aluminum, is this (spray painting) recommended at all? Probably need to use a primer as well. Oh, and do I need to finish/seal the inside of the wooden case?


----------



## Doc B.

You can sand lightly between varnish coats and carefully wipe the dust off (tack rags are great) to get a really smooth finish. Hammertone type paint is probably the easiest finish to apply to the chassis plate, and quite durable after it hardens for a couple of weeks. I just lay on several thin coats in quick succession ( don't let them dry) to build up one heavier coat that hammers out very nicely - no primer is necessary with this paint. It will work on the transformer bell too, just be sure to clean both the plate and bell really well with a good degreaser like Formula 409 or maybe some VM&P Naptha before spraying.


----------



## Armaegis

Quote: 





kongmw said:


> Thanks Doc! Now other than the initial sanding with 220 grit paper, is there additional sanding required between the polyurethane coats? I might just forego the staining part this time to minimize my chance of messing it up entirely. Although I'm still thinking of spray-painting the panel so it's not bare aluminum, is this (spray painting) recommended at all? Probably need to use a primer as well. Oh, and do I need to finish/seal the inside of the wooden case?


 

 If you do decide to stain, I found the lighter ones easier to work with as a beginner. The dark stuff get get splotchy if you don't do it right or some of it rounds a corner if you don't notice it.


----------



## captouch

Quote: 





kongmw said:


> Thanks Doc! Now other than the initial sanding with 220 grit paper, is there additional sanding required between the polyurethane coats? I might just forego the staining part this time to minimize my chance of messing it up entirely. Although I'm still thinking of spray-painting the panel so it's not bare aluminum, is this (spray painting) recommended at all? Probably need to use a primer as well. Oh, and do I need to finish/seal the inside of the wooden case?


 

 As a beginner to all this, I did have some complications with the stain and finish.  The staining complications came from having some wood glue seepage near the corners that affected absorption of the stain in those areas.  If I had to do it again, I'd put blue painters tape on the exterior edges so any glue seepage would be blocked from hitting the actual wood.  And then the spray on polyeurethane I used either didn't go on thick enough or I didn't wait long enough for it to dry (though I wanted 24hrs which the instructions said was fully dry), because when I tried to sand before the final coat, I ended up sanding some of the stain off.  So if you like the natural alder color okay, it would eliminate one possible mess-up to just leave it natural color and finish it.  Even if it's not perfectly smooth, you're not dealing with a non-uniform or blotchy stain.
   
  As for the bare aluminum, that was pretty easy.  I used Rustoleum Universal (primer and paint in one) Metallic spray paint.  The only non-ideal thing I did was not apply it as uniformly as I should have, but it didn't show up as bad in the end.  As they advise, more light coats is better than few heavy costs in terms of the end result. Both with the build itself (soldering) and the finishing, don't rush if you can help it.  Be patient.


----------



## Armaegis

For the hammertone, I've seen some guys recommend doing one heavy coat rather than multiple thin ones. Has anyone tried both methods?


----------



## Doc B.

Yes, I have. What I am describing is to wait like 30 seconds between coats - the paint does not dry, but it gets a chance to level out - and you avoid getting runs or fisheyes. Shooting it all in one blast can create those problems


----------



## kongmw

thanks guys for all the help! will be ordering tonight, i don't think im going to be able to wait for my next paycheck


----------



## mosshorn

Hopefully will be ordering one of these in the near future for my DT990 600ohms.....can't wait!!!!!


----------



## MilesDavis2

Quote: 





mosshorn said:


> Hopefully will be ordering one of these in the near future for my DT990 600ohms.....can't wait!!!!!


 


   
  Oh yes, for your 600 ohm beyers, order it ASAP!


----------



## kongmw

just ordered my Crack! let the waiting commence


----------



## Raguvian

Sorry if this has been asked before, but how would the Crack sound with Grados? Does it work well with them?
   
  Also, how hard is it to build? Is the wood finishing necessary or more of a customizing thing? I'm good at soldering wires and have had a bit of experience with soldering PCB's, but I'd still rather not mess up a $220 kit.
   
  Thanks


----------



## BmWr75

Quote: 





raguvian said:


> Sorry if this has been asked before, but how would the Crack sound with Grados? Does it work well with them?
> 
> Also, how hard is it to build? Is the wood finishing necessary or more of a customizing thing? I'm good at soldering wires and have had a bit of experience with soldering PCB's, but I'd still rather not mess up a $220 kit.
> 
> Thanks


 

 No, Grados are low impedance cans.......right?  The Crack is OTL so only works well with high impedance cans, >200 ohms per bottlehead.com.  It hums pretty bad and distorts with low impedance cans.
   
  It is not hard to build.  Was the most complex electronics project I had done at the time, probably still is.  But the provided step by step instructions are excellent and easy to follow.  Mine worked great with no troubleshooting required.


----------



## Doc B.

It has not been my experience that Crack hums and distorts with low impedance headphones. The biggest issue I have noticed is that the bass tends to be loose. At any rate the Smack amp and the S.E.X. amp will both work very well with Grados.


----------



## MilesDavis2

Quote: 





raguvian said:


> Sorry if this has been asked before, but how would the Crack sound with Grados? Does it work well with them?
> 
> Also, how hard is it to build? Is the wood finishing necessary or more of a customizing thing? I'm good at soldering wires and have had a bit of experience with soldering PCB's, but I'd still rather not mess up a $220 kit.
> 
> Thanks


 


 They said that low impedance phones won't sound good but I plugged my SR80 and it sounded good to me.


----------



## Armaegis

Quote: 





raguvian said:


> Also, how hard is it to build? Is the wood finishing necessary or more of a customizing thing? I'm good at soldering wires and have had a bit of experience with soldering PCB's, but I'd still rather not mess up a $220 kit.


 
  The instructions are quite comprehensive. The Crack was my first big project and I managed through it without too much trouble. I recommend cutting out all the wire lengths and stripping them ahead of time; it makes life a lot easier.


----------



## captouch

I'm in the process of registering on Bottlehead's site for the forum, but meanwhile, thought I'd pose the question here.
   
  I have a low level audible hum on my Crack, in both channels, and it doesn't vary with the volume knob.  When I tap the side of the chassis, sometimes I can get it to go away, but most of the time it's there.  When I turn off the Crack using on/off switch, I hear some static and a semi-loud pop before it finally powers off.  I tried different tubes, so it's not the tubes.
   
  Anyone have any ideas?  Can a cold solder joint can cause a hum like this?  Since it's on both channels and not dependent upon volume control, can I conclude it's somewhere early in the signal/power chain?
   
  I just upgraded to Speedball tonight.  The hum was there before the upgrade, I was semi-hoping that the upgrade might cure the hum, but not so lucky.
   
  I have to admit. . .and maybe this is where I start.  I never did voltage checks after the original build or upgrade.  I figured the whole thing was powered up already, the tubes were on, and I'd take a chance by plugging in a cheap pair of headphones and just seeing whether I get music rather than risk shocking myself silly.  

 But maybe I'll have to do some voltage probing after all.  One thing I couldn't figure out how everyone else handles: When your tubes are in and you're probing voltages, do you prop up the amp at an angle so you have access to the underside without having the amp sitting tube side down?  Or have it sit upside down in the chassis and route the power cord from below?
   
  Thanks for any help - I know this is technical support, but since this is a DIY and this is really bugging me (and while I'm waiting for my request to be approved on Bottlehead's forum), I'm hoping for some thoughts/suggestions in the meanwhile.


----------



## Armaegis

I would definitely run the voltage check. Also check for an offset from the headphone jack L/R to ground.
   
  When I was testing mine, I just flipped it over and propped it up at an angle with whatever random object I had nearby.


----------



## glenda

What is the highest Vrms output before clipping (~assume voltage limited ie 600 ohm cans)?


----------



## Todd R

captouch
  I think you are on the right track with a bad solder joint early in the chain. 
  Just go back & reheat them. That amp doesn't have that many parts and shouldn't take long.


----------



## captouch

Quote: 





armaegis said:


> I would definitely run the voltage check. Also check for an offset from the headphone jack L/R to ground.
> 
> When I was testing mine, I just flipped it over and propped it up at an angle with whatever random object I had nearby.


 

 Checked all voltages.  All within 10-15% of expected.
   
  However, the final voltage check for the HP jack: About 15s after power on, the voltage spikes above 20v momentarily before going back to zero (stays there after that).  When I power off, it hits about -14-15V.  I know it's only supposed to go to 9v upon power on.
   
  Any idea what might be causing mine to spike to a higher voltage?  
   
  I reheated the joints early in the chain (from socket plug to power switch to power supply for L/N/G), but same thing still happening.  Haven't plugged in any cans to see if the hum is still there (will use cheap ones and plug them in after warm-up).
   
  But not sure if the 20V HP jack issue is related to the hum or not.


----------



## Doc B.

The voltage will go higher than 9V with the speedball upgrade. I don't think this is related to the hum.
   
  A couple of questions that might lead to a better idea of where the issue comes from:
  What headphones are you using? Sensitivity? We have noticed that some headphones tend to emphasize low level hum, as if they perhaps have a boost in their response around 60 or 120Hz.
  Is the hum buzzy, or not-buzzy/soft sounding? Buzzy hum might mean that you have a ground issue like a ground loop or a sketchy ground connection. Soft hum might be the pickup of the magnetic field of a nearby transformer.


----------



## kongmw

alright guys, need some help here. 
	

	
	
		
		

		
			




   
  so today was the second day i spent on wiring my crack and everything was going smoothly until when doing the voltage check on A8, I accidentally shorted the pin with A9. so the LED between A8 and center pin went out and I think I blew one channel there. Some voltage readings related to that blown channel went crazy a bit. (say terminal 1 was reading ~90V and now it reads 140V, terminal 2 was at 165V now it's 154V) 
   
  the other LED between center pin on and A4 is still on and the voltage on A4 is 1.5, whereas the voltage on A8 now is ~14V. 
   
  any idea how to fix this? can i just replace the little LED? 
   
  any input is appreciated. thanks!


----------



## skeptic

Yup - you're going to want to replace that LED.  I damaged an LED while installing my speedball and got a very similar voltage at A8.  (As discussed here: http://www.bottlehead.com/smf/index.php/topic,1825.0.html )
   
  If you call Bottlehead during business hours, they should be able to mail you a couple of replacement LED's.  Per the link I posted, you do not want to try and substitute another generic LED for the HLMP-6000.


----------



## kongmw

Quote: 





skeptic said:


> Yup - you're going to want to replace that LED.  I damaged an LED while installing my speedball and got a very similar voltage at A8.  (As discussed here: http://www.bottlehead.com/smf/index.php/topic,1825.0.html )
> 
> If you call Bottlehead during business hours, they should be able to mail you a couple of replacement LED's.  Per the link I posted, you do not want to try and substitute another generic LED for the HLMP-6000.


 


  thanks for the quick reply! i'll try contacting them tomorrow. 
   
  this is such a bummer tho, i was really hoping to hook this up to my HD650 tonight 
	

	
	
		
		

		
		
	


	



   
  oh well...


----------



## Armaegis

I think a busted LED must be one of the most common errors encountered.


----------



## captouch

Quote: 





doc b. said:


> The voltage will go higher than 9V with the speedball upgrade. I don't think this is related to the hum.
> 
> A couple of questions that might lead to a better idea of where the issue comes from:
> What headphones are you using? Sensitivity? We have noticed that some headphones tend to emphasize low level hum, as if they perhaps have a boost in their response around 60 or 120Hz.
> Is the hum buzzy, or not-buzzy/soft sounding? Buzzy hum might mean that you have a ground issue like a ground loop or a sketchy ground connection. Soft hum might be the pickup of the magnetic field of a nearby transformer.


 

 Thanks Doc.  
   
  I'm using DT880/600's and HD650's.  
   
  The hum is not buzzy/soft sounding.  More of a hummm.  The Crack is sitting on my pre-amp, so I thought (after seeing your post) that it might have been picking up the pre-amp transformer, but I lifted it up and it was still there.  
   
  When I tried gently jiggling the base of the 6080 tube, I could get it to go away.  Perhaps I have a cold solder joint on one of the connections to the 8-pin tube socket?


----------



## Doc B.

Try cleaning the pins of the 6080. These tubes are new old stock from 40 or more years ago, and they can get some oxidation on the pins. A Q-Tip and some metal polish or contact cleaner will usually do the trick. If you have a Dremel tool you can cut the Q-Tip in half and chuck it into the Dremel to make a teeny polishing bit. Just scrubbing the pins a bit with a scotchbrite pad can help if you don't have any cleaner handy. Even inserting the tube into the socket a few times can clean some oxidation off.


----------



## kongmw

hey Doc, wanted to ask you if those HLMP-6000 LEDs on the 9pin socket are the same as these guys (found on digikey http://search.digikey.com/us/en/products/HLMP-6000/516-1396-ND/637657)
   
  thanks!


----------



## Doc B.

Yes, those are the same.


----------



## kongmw

Quote: 





doc b. said:


> Yes, those are the same.


 


  Thanks! I did email Eileen about maybe getting a couple of them for replacements from you guys. But if it's just too much hassle then I could just always order my own.


----------



## kongmw

Quote: 





kongmw said:


> Thanks! I did email Eileen about maybe getting a couple of them for replacements from you guys. But if it's just too much hassle then I could just always order my own.


 


  Aaaaaaaand Eileen will be putting a couple of LEDs in the mail for me today. Man this must be the best customer service I've ever experienced.


----------



## skeptic

Quote: 





doc b. said:


> Try cleaning the pins of the 6080. These tubes are new old stock from 40 or more years ago, and they can get some oxidation on the pins. A Q-Tip and some metal polish or contact cleaner will usually do the trick. If you have a Dremel tool you can cut the Q-Tip in half and chuck it into the Dremel to make a teeny polishing bit. Just scrubbing the pins a bit with a scotchbrite pad can help if you don't have any cleaner handy. Even inserting the tube into the socket a few times can clean some oxidation off.


 
   
  Definitely give this a shot.  Doc gave me the same advice 6 months back concerning some hum I was hearing in one of my older 12bh7a's.  Sure enough, a few minutes with some fine grain sandpaper, followed by inserting/reinserting the tube several times cured it.


----------



## captouch

Quote: 





skeptic said:


> Definitely give this a shot.  Doc gave me the same advice 6 months back concerning some hum I was hearing in one of my older 12bh7a's.  Sure enough, a few minutes with some fine grain sandpaper, followed by inserting/reinserting the tube several times cured it.


 

 Thanks Doc and Skeptic.  Will give this a shot.  It seemed to be there with two different tubes (original 6080 and a 5998), but both are old, so will do some polishing and see if it goes away.


----------



## kongmw

so i replaced the blown LED and my Crack is finally up and running! 
	

	
	
		
		

		
		
	


	



   
  now I don't really hear a lot of microphonics when I tap the chassis/case but what does come through only exists in the left channel. is this more tube related than anything else? I'm just starting out with the whole tube amp business so I don't have a couple of spare ones to swap out. Will be getting some of both 6080 and 12au7 after thanksgiving.


----------



## Draygonn

kongmw said:


> so i replaced the blown LED and my Crack is finally up and running!




This is the last thing I have to do.


----------



## skeptic

Quote: 





kongmw said:


> so i replaced the blown LED and my Crack is finally up and running!


 
   
  Congrats kong!  Very glad to hear this did the trick.


----------



## Hughkk

can someone take a pic of the bottom of the amp please


----------



## Armaegis

Quote: 





hughkk said:


> can someone take a pic of the bottom of the amp please


 

 there are pics are on product page...
http://www.bottlehead.com/store.php?crn=224&rn=442&action=show_detail
http://www.bottlehead.com/store.php?crn=224&rn=446&action=show_detail


----------



## Hughkk

so it is a sheet of metal with those part on top?
  or are those parts hanging down the bottom of the amp?
   
  I hav read those pages and thought those are inside the amp, isn't it??


----------



## RingingEars

Quote: 





hughkk said:


> or are those parts hanging down the bottom of the amp?


 


  Yes.


----------



## captouch

Quote: 





hughkk said:


> so it is a sheet of metal with those part on top?
> or are those parts hanging down the bottom of the amp?
> 
> I hav read those pages and thought those are inside the amp, isn't it??


 

 They hang from the bottom of the metal plate that sits unattached (its weight keeps it in place) on top of the wood base.  So it's protected from the sides and top, but there's no bottom protection under the wood base.  So it could get damaged from below if you're not careful, plus have to make sure the metal plate doesn't fall off the wood base if it gets turned sideways or upside down, though some people screw the top down.
   
  Really don't think I'd regularly travel with the Crack.


----------



## Hughkk

will making a protection under the bottome affect the performance?


----------



## BmWr75

Quote: 





hughkk said:


> will making a protection under the bottome affect the performance?


 

 It could if you block off the air circulation.  The amp might overheat.


----------



## captouch

Quote: 





hughkk said:


> will making a protection under the bottome affect the performance?


 

 I suppose you could make it removable so you only put it on when you travel.  But still, I don't think you want this jostled around much - definitely hand-carry not check-in!  Or buy a hard-case for it to protect the bottom - but still hand-carry though not sure what TSA will make of it.


----------



## Armaegis

I wonder if anyone has ever made a pcb version of the Crack?


----------



## tdogzthmn

Anyone here use an E80CC tube?  I have a Valvo branded one with the gold pins which sounds a bit brighter than the average 12au7 but I enjoy the clear sounding and detailed tubes.


----------



## Chuke

Just ordered a Crack kit the other day...and finally finished reading the 59 pages of this thread.  Thanks everyone.  Great info.  
   
  I haven't soldered in about 30 years, so this should be fun!


----------



## Hughkk

thanks everyone.
  i think i might put my crack in home and get a solid amp like m-stage matrix or asgard to travel.
   
  Well that's expensive


----------



## skeptic

Sounds like a good plan hughkk.  For travel - you might also consider an O2.  It is transportable by design, and I suspect it measures quite a bit better than the asgard and m-stage - for about half the cash.
   
  As far as putting some protection under the bottom of the crack - a screen of some sort would probably do the trick without creating heat issues.


----------



## Armaegis

Quote: 





skeptic said:


> For travel - you might also consider an O2.  It is transportable by design, and I suspect it measures quite a bit better than the asgard and m-stage


 

 I really wish people would stop assuming this sort of thing.


----------



## skeptic

If I'm wrong, I'm happy to be corrected...  Have you seen numbers posted for either of those amps?  Various comments on the O2 designer's site (and elsewhere) led me to believe that those two amps probably weren't as accurate as one designed for the purpose of measuring well (particularly when the matrix is being forced to run in class A), but hey, I'm more than happy to consider any evidence to the contrary.
   
  With respect to widespread generalizations concerning the O2, this is, in my mind, largely the unfortunate result of the ban on linking directly, or indirectly, or citing to specifics from the designer's site.  I can understand your frustration to that extent at least.
   
  Edit: to the extent one can base a conclusion on the _minimal_ specs published by the makers of the asgard and matrix, the O2 does, in fact, appear to measure better than either amp.  Caveat: the m-stage folks only provide THD at 300ohms (without specifying frequency), so you can't easily compare and contrast this with the more detailed THD measurements posted by the O2 designer (at 15 and 150 ohms, at various frequencies).


----------



## Armaegis

I don't have a bone to pick either way, but I'm just so tired of the O2 getting hyped. I don't mind people offering it as a alternative choice, but to add on "and it probably measures better" is the part that irks me.


----------



## skeptic

I'm more irked by all the marketing hype for commercial amps that, in this case at least, don't measure as well as a ultra affordable alternative. To each their own though. 

Sent from my ADR6400L using Tapatalk


----------



## Beefy

Quote: 





skeptic said:


> I'm more irked by all the marketing hype for commercial amps that, in this case at least, don't measure as well as a ultra affordable alternative. To each their own though.


 

 Thankyou for enlightening us. Now, there's the door.


----------



## skeptic

Quote: 





beefy said:


> Thankyou for enlightening us. Now, there's the door.


 
   
  I'm not sure if you read the prior page or just lept into the fray, but for context, my post was a continuation of a discussion on the previous page, responding to a question from hughkk about purchasing a transportable amp to _complement_ his anticipated BH Crack - which I (among others) highly recommended and discussed with him at some length in the hd650 thread.
   
  I suggested looking at the O2 as a semi-portable simply because (i) I "suspect[ed]" it measured better than two other options he was considering - which it apparently does; and (ii) it is cheap.  If there's a reason you disagree with this suggestion - I'd be interested to hear it.  In any event, I don't want to derail this thread any further.  
   
  I really appreciated your guidance in building my crack beefy, and I'm sorry my quip rubbed you the wrong way.  I didn't mean to stomp any toes - well aside from armaegis', just a little.


----------



## Aart

Quote: 





skeptic said:


> I'm not sure if you read the prior page or just lept into the fray, but for context, my post was a continuation of a discussion on the previous page, responding to a question from hughkk about purchasing a transportable amp to _complement_ his anticipated BH Crack - which I (among others) highly recommended and discussed with him at some length in the hd650 thread.
> 
> I suggested looking at the O2 as a semi-portable simply because (i) I "suspect[ed]" it measured better than two other options he was considering - which it apparently does; and (ii) it is cheap.  If there's a reason you disagree with this suggestion - I'd be interested to hear it.  In any event, I don't want to derail this thread any further.
> 
> I really appreciated your guidance in building my crack beefy, and I'm sorry my quip rubbed you the wrong way.  I didn't mean to stomp any toes - well aside from armaegis', just a little.


 

 Don't say "sorry" man, that's lame. You gave advice and your opinion, you didn't offend anyone and even if you did, it's your opinion, don't apoligize.
   
  I don't know anything about electrical engineering and very little to nothing about audio but what I did notice during these first couple of months of browsing amps,headphones,sources,.. is that a lot of people aren't buying what they think sounds best, they are buying what other people are buying because it's supposed to be the best, earns you the most bragging rights and makes you feel special.
   
  Apart from buying and building a CRACK, all I've done is browse amps/sources, you know, dream a little about what I'd get for when the upgrading day comes. When I read about the O2, my first reaction was to deny it and ignore it.. It simply isn't as special as any other amp that you can buy. I would rather have bought a schiit amp and DAC than look into the O2. Wonder what it must feel like when you actually own any of the gear that the O2 supposedly beats.
   
*On topic*: The hum is back .. what the hell.. my crack was dead silent for a couple of weeks, didn't use it for one week and now the hum is back. I swapped between my two 5998 and it's identical, I swapped back to my stock tube and the hum was superlow, it was still there, exactly the same but a lot more silent (to the point it isn't an issue anymore). I have noticed that volume is louder with the 5998 compared to the stock tubes. My gut tells me that the problem is actually the 12AU7 tube but that the hum is simply louder because volume in general is louder with the 5998, could this be correct?
  Last time I had this problem (hum, volume independent), it was the 12AU7 tube.
   
  Thx in advance


----------



## Hughkk

have a hard time finding soldering equipment, don't know the size of wire, solder, nothing


----------



## Aart

Quote: 





hughkk said:


> have a hard time finding soldering equipment, don't know the size of wire, solder, nothing


 


  I can't imagine it matters that much for this project.


----------



## Hughkk

Quote: 





aart said:


> I can't imagine it matters that much for this project.


 

  
  i hav 0 experience for soldering.
  don't even know how it works.
   
  BTW is 1mm 60/40 solder wire good for this project?
http://www.amazon.co.uk/gp/product/B001IHGCRE/ref=ox_sc_act_title_6?ie=UTF8&m=A2N9G9UY1E6KSU
  these one


----------



## Aart

Quote: 





hughkk said:


> i hav 0 experience for soldering.
> don't even know how it works.
> 
> BTW is 1mm 60/40 solder wire good for this project?
> ...


 


  http://diyaudioprojects.blogspot.com/2011/04/how-to-solder-comic-book-guide.html


----------



## BmWr75

Quote: 





aart said:


> *On topic*: The hum is back .. what the hell.. my crack was dead silent for a couple of weeks, didn't use it for one week and now the hum is back. I swapped between my two 5998 and it's identical, I swapped back to my stock tube and the hum was superlow, it was still there, exactly the same but a lot more silent (to the point it isn't an issue anymore). I have noticed that volume is louder with the 5998 compared to the stock tubes. My gut tells me that the problem is actually the 12AU7 tube but that the hum is simply louder because volume in general is louder with the 5998, could this be correct?
> Last time I had this problem (hum, volume independent), it was the 12AU7 tube.
> 
> Thx in advance


 

 What HPs are you using with the Crack?


----------



## Aart

HD650's


----------



## BmWr75

Have you tried cleaning the pins on your 12AU7 tube?   Deoxit will do the trick.  Easy to do and might solve the problem.  Just a guess.


----------



## Hughkk

how much solder wire is needed?
  planning to buy a 500g 63/37 at about 40USD.
  do i need that much?
   
  don't seeing myself doing another soldering job in a few years


----------



## captouch

Quote: 





hughkk said:


> how much solder wire is needed?
> planning to buy a 500g 63/37 at about 40USD.
> do i need that much?
> 
> don't seeing myself doing another soldering job in a few years


 


  Don't think you need that much.  I bought this one for about $7.50:
http://www.amazon.com/gp/product/B00030AP48/ref=oh_o00_s00_i01_details
   
  Have plenty left over.  
   
  If you don't get a soldering station, at least get a iron holder:
http://www.amazon.com/Elenco-Soldering-Iron-Holder/dp/B0002LLWEU/ref=sr_1_cc_1?s=electronics&ie=UTF8&qid=1321980302&sr=1-1-catcorr
   
  You'll need to set the iron down many times and you don't want to worry about where it is or burning yourself - a holder keeps it contained and out of your way.
   
  Any questions on anything, feel free to PM me.  I understand it can be intimidating for someone who hasn't soldered before - I was very much a newbie as well.


----------



## Doc B.

Quote: 





hughkk said:


> how much solder wire is needed?
> planning to buy a 500g 63/37 at about 40USD.
> do i need that much?
> 
> don't seeing myself doing another soldering job in a few years


 


  That's practically a lifetime supply! You probably need more like a 50 gm. reel. Around 0.8mm is good, 63Sn/37Pb is a good choice. Lead free like 96Sn/4Ag is OK too, but a lot harder to work with. I would also suggest looking at a Hakko 936 solder station.


----------



## Armaegis

When I built my second Crack, I pre-cut/stripped all the wires beforehand which made the work immensely easier and faster.
  
   
  Quote: 





aart said:


> *On topic*: The hum is back .. what the hell.. my crack was dead silent for a couple of weeks, didn't use it for one week and now the hum is back. I swapped between my two 5998 and it's identical, I swapped back to my stock tube and the hum was superlow, it was still there, exactly the same but a lot more silent (to the point it isn't an issue anymore). I have noticed that volume is louder with the 5998 compared to the stock tubes. My gut tells me that the problem is actually the 12AU7 tube but that the hum is simply louder because volume in general is louder with the 5998, could this be correct?
> Last time I had this problem (hum, volume independent), it was the 12AU7 tube.
> 
> Thx in advance


 

 Did you recheck you voltages and LEDs?


----------



## greggie

Tools I purchased for my Crack build:

 Hakko FX-888 solder station
 Xcelite 54CG wire cutters
 Xcelite 57CG needle-nose pliers
 Ideal Stripmaster automatic wire stripper
   
  The Xcelite tools are small and easy to maneuver in tight spaces.  The solder station heats very quickly and maintains temperature well, plus there is a wide range of tips available.  However, I used the stock tip that came with the unit.  The automatic wire stripper is wonderful and I can't believe I waited all these years to get one...
   
  You may not have access to these exact items, but can find their equivalents.
   
   



hughkk said:


> don't seeing myself doing another soldering job in a few years


 
   
  Don't forget about the Speedball upgrade!


----------



## Hughkk

here is my list to buy to prepare for my soldering:
http://www.amazon.co.uk/gp/product/B001KOTNK8/ref=ox_sc_act_title_9?ie=UTF8&m=A2HSTWY2X7JJ9H





http://www.amazon.co.uk/gp/product/B004HSSJXG/ref=ox_sc_act_title_8?ie=UTF8&m=A2X1ST6CC1USDW




http://www.amazon.co.uk/gp/product/B000O3RJFC/ref=ox_sc_act_title_7?ie=UTF8&m=AOM7YUJHF35YE




http://www.amazon.co.uk/gp/product/B000LFTMUI/ref=ox_sc_act_title_6?ie=UTF8&m=A1LX22KXKURBO0




http://www.amazon.co.uk/gp/product/B000ELJ0C4/ref=ox_sc_act_title_5?ie=UTF8&m=A3P5ROKL5A1OLE




http://www.amazon.co.uk/gp/product/B000LFTKKK/ref=ox_sc_act_title_4?ie=UTF8&m=A1FD9VFM4GBHD




http://www.amazon.co.uk/gp/product/B004O9DQ36/ref=ox_sc_act_title_3?ie=UTF8&m=A1K4MY34Z7396A




http://www.amazon.co.uk/gp/product/B003D07BVK/ref=ox_sc_act_title_2?ie=UTF8&m=A2DICHIH6QJA6P




http://www.amazon.co.uk/gp/product/B0034BLRSQ/ref=ox_sc_act_title_1?ie=UTF8&m=A3P5ROKL5A1OLE




   
  here is my list to buy
   
  will you kindly tell me if i bought something xtra or missed something?
   
  thanks in advance


----------



## BmWr75

None of your links work for me (I'm in the U.S.).


----------



## captouch

Quote: 





bmwr75 said:


> None of your links work for me (I'm in the U.S.).


 
  Hughkk sent me the links in PM, they worked there.  Here they are:
   

http://www.amazon.co.uk/gp/product/B001KOTNK8/ref=ox_sc_act_title_9?ie=UTF8&m=A2HSTWY2X7JJ9H




http://www.amazon.co.uk/gp/product/B004HSSJXG/ref=ox_sc_act_title_8?ie=UTF8&m=A2X1ST6CC1USDW




http://www.amazon.co.uk/gp/product/B000O3RJFC/ref=ox_sc_act_title_7?ie=UTF8&m=AOM7YUJHF35YE




http://www.amazon.co.uk/gp/product/B000LFTMUI/ref=ox_sc_act_title_6?ie=UTF8&m=A1LX22KXKURBO0




http://www.amazon.co.uk/gp/product/B000ELJ0C4/ref=ox_sc_act_title_5?ie=UTF8&m=A3P5ROKL5A1OLE




http://www.amazon.co.uk/gp/product/B000LFTKKK/ref=ox_sc_act_title_4?ie=UTF8&m=A1FD9VFM4GBHD




http://www.amazon.co.uk/gp/product/B004O9DQ36/ref=ox_sc_act_title_3?ie=UTF8&m=A1K4MY34Z7396A




http://www.amazon.co.uk/gp/product/B003D07BVK/ref=ox_sc_act_title_2?ie=UTF8&m=A2DICHIH6QJA6P




http://www.amazon.co.uk/gp/product/B0034BLRSQ/ref=ox_sc_act_title_1?ie=UTF8&m=A3P5ROKL5A1OLE


----------



## greggie

Quote: 





hughkk said:


> here is my list to buy to prepare for my soldering:
> http://www.amazon.co.uk/gp/product/B001KOTNK8/ref=ox_sc_act_title_9?ie=UTF8&m=A2HSTWY2X7JJ9H
> 
> 
> ...


 

 I was only able to see those links by copying them as text and pasting into my browser.
   
  Everything looks good with these exceptions.
   
  The first item, the pliers, should be needle-nose pliers.  You will need this tool to bend component leads, thread them through the terminal strips, and crimp them in place before soldering.  It is delicate work and the pliers you picked are blunt-nose, not correct for the job.  Perhaps these:
http://www.amazon.co.uk/Silverline-250388-Needle-Nose-Pliers/dp/B001C7HJ6I
   
  You do not have wire strippers in your list.  I would suggest this one:
http://www.amazon.co.uk/Rolson-Tools-20857-Automatic-Striper/dp/B001KOTNLW
   
  The Helping Hands are interesting, but I'm not sure they will be useful.  The components are all being attached to the aluminum chassis plate which you will have on the table, and I do not think the clips on the Hands will reach.  The magnifying glass might be handy.


----------



## Hughkk

i'm getting these stripers instead
http://www.amazon.co.uk/gp/product/B000LFTNKW/ref=ox_sc_act_title_1?ie=UTF8&m=A2KWSZB804VQD5
   
  don't think it will make a difference?
  trying to save every pound, since if i add all those tools together, it will cost be 50pounds, which is like 80USD


----------



## greggie

Quote: 





hughkk said:


> i'm getting these stripers instead
> http://www.amazon.co.uk/gp/product/B000LFTNKW/ref=ox_sc_act_title_1?ie=UTF8&m=A2KWSZB804VQD5
> 
> don't think it will make a difference?
> trying to save every pound, since if i add all those tools together, it will cost be 50pounds, which is like 80USD


 


  Those strippers will work just fine.  Good luck with your build.


----------



## Armaegis

For a second I thought I was in the lounge and thought... "Whoa, you can buy those on Amazon...?!?"


----------



## greggie

Quote: 





armaegis said:


> For a second I thought I was in the lounge and thought... "Whoa, you can buy those on Amazon...?!?"


 


  That's why we LOVE Amazon!!!


----------



## tdogzthmn

My HD800's arrived this morning and have since spent an hour or two running with the Crack.  It is still very early to form any solid opinion but my feelings so far is that the HD600 does a better job with the Crack than the HD800 overall.  There seems to be a natural pairing between the HD600 which is lost when I switch over, and is more noticeable with faster genres of music.  On the other hand I can hear the superiority's of the HD800 with some of the high-res acoustic music.  Just some thoughts, but it would be good to hear from others who also have both cans.


----------



## Hughkk

got a crack two weeks before,
  anyone know how long does the shipping take?
   
  and can anyone tell me what HP i should get to pair with my amp?
  have HD650 in mind, but the veiled thing made me consider again


----------



## Doc B.

We have been swamped with orders for Crack kits the past couple of months, and we're playing catch-up. Right now we are awaiting an order of chassis panels and once those are here we should begin shipping again.


----------



## Hughkk

will they be avaliable before christmas? roughly


----------



## Doc B.

We just checked and the laser cutter says the plates are about 10 - 12 days out.


----------



## skeptic

Quote: 





hughkk said:


> and can anyone tell me what HP i should get to pair with my amp?
> have HD650 in mind, but the veiled thing made me consider again


 

 While the crack also sounds great with DT880's, my favorite pairing is with Sennheisers.  Unless you are contemplating picking up a pair of HD800's, HD650's or HD600's definitely get my vote.  There is nothing at all "veiled" about the way the 650's sound with the crack to my ears.


----------



## Hughkk

Quote: 





skeptic said:


> While the crack also sounds great with DT880's, my favorite pairing is with Sennheisers.  Unless you are contemplating picking up a pair of HD800's, HD650's or HD600's definitely get my vote.  There is nothing at all "veiled" about the way the 650's sound with the crack to my ears.


 


  thanks
  then hd650 it is.
   
  hope can save enough money to get it before easter


----------



## captouch

Quote: 





hughkk said:


> thanks
> then hd650 it is.
> 
> hope can save enough money to get it before easter


 
   
  I thought they (DT880/600 and HD650) both sounded great with the Crack.  I haven't done any comparisons since I installed the Speedball.  I'll compare them soon and post some thoughts.


----------



## Hughkk

Quote: 





captouch said:


> I thought they (DT880/600 and HD650) both sounded great with the Crack.  I haven't done any comparisons since I installed the Speedball.  I'll compare them soon and post some thoughts.


 

 thank you
  looking forward to it


----------



## Hughkk

and i also want to ask, since i have no experience on soldering/diy before, would it be a better idea if i diy a cmoy before assmbling a bottlehead crack?
  or makin crack as my first ever soldering diy project is good?


----------



## greggie

Quote: 





hughkk said:


> and i also want to ask, since i have no experience on soldering/diy before, would it be a better idea if i diy a cmoy before assmbling a bottlehead crack?
> or makin crack as my first ever soldering diy project is good?


 


  It will not hurt, but I think it is not necessary - unless you want a cmoy as well.  There is a difference between soldering components on a printed circuit board (cmoy) and the point-to-point wiring of the Crack.  You can practice soldering easily enough by removing insulation from two pieces of wire, twisting them together, and flowing solder into them.


----------



## tdogzthmn

Quote: 





hughkk said:


> and i also want to ask, since i have no experience on soldering/diy before, would it be a better idea if i diy a cmoy before assmbling a bottlehead crack?
> or makin crack as my first ever soldering diy project is good?


 


  The Crack was my first DIY project and I found it to be very straight forward it you follow the directions which are quite easy and can always ask for help on headfi or bottlehead's own website if you need it.  There is a certain satisfaction you get from building your own product that can not be emulated and often leads to a more intimate listening experience.  
   
  So yes, makin crack as my first ever soldering diy project is good!


----------



## captouch

Quote: 





hughkk said:


> thank you
> looking forward to it


 

 Agree with Skeptic after listening last night - I'd go with HD650's.
   
  DT880's sound nice and highs are more prominent (and they sound a bit faster and more air), but they don't sound as full or as well-integrated to me.  Very detailed and I might choose them for critical listening, but I find the HD650's more pleasant to listen to when just enjoying the music.  HD650 highs and details are still very much present and not lacking and I wouldn't call them slow - I just feel like everything is better blended.
   
  But this difference and what is better is going to depend upon listener preference (if you like prominent highs, the most detail, fastest and most air), then you might prefer the DT880's.


----------



## Hughkk

Quote: 





captouch said:


> Agree with Skeptic after listening last night - I'd go with HD650's.
> 
> DT880's sound nice and highs are more prominent (and they sound a bit faster and more air), but they don't sound as full or as well-integrated to me.  Very detailed and I might choose them for critical listening, but I find the HD650's more pleasant to listen to when just enjoying he music.  HD650 highs and details are still very much present and not lacking and I wouldn't call them slow - I just feel like everything is better blended.
> 
> But this difference and what is better is going to depend upon listener preference (if you like prominent highs, the most detail, fastest and most air), then you might prefer the DT880's.


 
  have u also heard from a HD600 too?
   
  i think i am going with HD650 since I don't prefer lots of details
   
  thanks


----------



## captouch

Quote: 





hughkk said:


> have u also heard from a HD600 too?
> 
> i think i am going with HD650 since I don't prefer lots of details
> 
> thanks


 


  No, would love to, but no opportunity yet.  Did you order the Speedball too?
   
  I think you'll be very satisfied with HD650 and Crack/Speedball.  
   
  Note, in my listening tests, I was using non-stock tubes.  I don't think that's going to affect anything by much, but FYI I was using a McIntosh branded RCA 12BH7 in place of the stock Electro Harmonix 12AU7 and a Tung Sol 5998 in place of the 6080 I was sent.  I think there is no one stock 6080 tube, as Bottlehead is shipping NOS of what they have (mine was a '72 Sylvania).
   
  Keep your eyes open for gently used HD650's - can save a few bucks this way.


----------



## Hughkk

i didn't order the speedball upgrade.
  i was planning to get the hd650 before getting the speedball.
  the only HP i have right now is SRH840, so i don't think it will sound very good in the crack
   
  I am kind of scared that i will break some parts while making the amp, or soldering into the wrong place.
  did u broke any parts in the amp when u are making it?
  do they have spare-parts just in case?


----------



## captouch

Quote: 





hughkk said:


> i didn't order the speedball upgrade.
> i was planning to get the hd650 before getting the speedball.
> the only HP i have right now is SRH840, so i don't think it will sound very good in the crack
> 
> ...


 
   
  No, I didn't break any parts.  The kit doesn't come with any spares, except extra wire length.  
   
  Of course I can't speak for them, but Bottlehead seems to be very good about replacing minor components (resistors, LED's, even the power switch I think I've read) that are accidentally damaged during the assembly process.  Of course if you somehow damage the transformer, that's probably a different story. . .


----------



## skeptic

Quote: 





captouch said:


> DT880's sound nice and highs are more prominent (and they sound a bit faster and more air), but they don't sound as full or as well-integrated to me.  Very detailed and I might choose them for critical listening, but I find the HD650's more pleasant to listen to when just enjoying he music.  HD650 highs and details are still very much present and not lacking and I wouldn't call them slow - I just feel like everything is better blended.


 

 Excellent description!  This is exactly how I perceive the differences between these two headphones as well.  But I've never been able to articulate it nearly as well as you just did.


----------



## skeptic

Quote:


hughkk said:


> .....did u broke any parts in the amp when u are making it?  do they have spare-parts just in case?


 

 No breakage here either, and the stock kit was my first diy project as well.  Most of the components in the crack kit are pretty robust.  If you are really worried about breakage, try watching a couple of youtube videos on basic soldering before you get going on it.  
   
  Understanding how heat transfers, and how you can form a "solder bridge" and then apply most of your solder from the back side of the joint, makes it a lot easier.  (Basically, if you hold the solder against the joint and touch it with the iron, then you can keep your iron in place, pull the solder away, and then "flow" the solder on by pressing it against the lead on the opposite side from where your iron is touching.  In essence, the heat transfers from the iron, through the "solder bridge" to the lead, which then melts the solder directly against itself.)
   
  I did damage an LED in the process of installing the standoffs for the speedball upgrade.  Be careful if/when you put in the upgrade kit, but BH was really great about sending me a couple of replacement LED's asap upon request.


----------



## Amarphael

captouch said:


> Top looks black, but isn't really.  It's Rustoleum Universal Metallic Oil-Rubbed Bronze.  Pretty easy to apply - satisfied with that.  A little sparkly at the right angles.


 
   
  Hey man, I really like the finish you came up with. Did you rougned it up with a sandpaper before applying the paint?


----------



## captouch

Quote: 





amarphael said:


> Hey man, I really like the finish you came up with. Did you rougned it up with a sandpaper before applying the paint?


 

 Yeah, I did.  I don't know if you really have to, because it was already a little rough, but I figured it wouldn't hurt and it only took a couple of extra minutes.


----------



## Unicorns

Does anyone know what the current delivery time is? I emailed them a little while ago, but no reply yet.
   
  I would have to get it within 3 weeks, but I doubt that's possible..


----------



## captouch

Quote: 





unicorns said:


> Does anyone know what the current delivery time is? I emailed them a little while ago, but no reply yet.
> 
> I would have to get it within 3 weeks, but I doubt that's possible..


 

[size=11.0pt]I'd give them a quick call @ (206) 451- 4275.  I'm sure they could tell you whether it's possible or not.[/size]


----------



## Doc B.

We have been really slammed with orders this season and we are cranking at full speed to keep up. We have already sold out the production run of chassis panels that are on their way to us and Eileen will be ordering another run today. It typically takes two weeks to get them. So I can confidently say "maybe" about getting a new Crack kit order out in three weeks.


----------



## lextek

Oops didn't see the above post.  I called and ordered one today.  They said they were waiting for the top plates.  Hoping they would have them by the end of the week.  Don't know if that helps.


----------



## Hughkk

Quote: 





doc b. said:


> We have been really slammed with orders this season and we are cranking at full speed to keep up. We have already sold out the production run of chassis panels that are on their way to us and Eileen will be ordering another run today. It typically takes two weeks to get them. So I can confidently say "maybe" about getting a new Crack kit order out in three weeks.


 


  so if i ordered it two weeks ago, when should i expect it to dispatch?


----------



## Unicorns

Ah, ok. Thanks for the reply.
  I'll think about putting in an order, and just suck it up I have to cancel it..
   
  Quote: 





doc b. said:


> We have been really slammed with orders this season and we are cranking at full speed to keep up. We have already sold out the production run of chassis panels that are on their way to us and Eileen will be ordering another run today. It typically takes two weeks to get them. So I can confidently say "maybe" about getting a new Crack kit order out in three weeks.


----------



## Doc B.

Quote: 





hughkk said:


> so if i ordered it two weeks ago, when should i expect it to dispatch?


 


  This kind of stuff is answered most accurately by giving Eileen a call or an email, as she has exact counts on inventory. What I know is that the chassis panel order that we have coming in this week is about three (it's been a couple of hours since I checked and orders are really rolling in these days, so it's probably now more like five) short of the current orders. I would imagine that an order from two weeks ago will be covered by the incoming shipment. And all of the orders from today will be covered by the shipment of panels we hope to see in a couple of weeks.
   
  Funny thing is we were pretty well caught up just a few weeks ago. It is really tough to predict when there will be a spike on a certain kit's orders. We sold so many Cracks in October that I kind of figured things would taper off a bit, but instead the orders keep pouring in. Not that I'm complaining!


----------



## MilesDavis2

It is worth the wait.  You won't be disappointed.


----------



## Tequilasunriser

Quote: 





doc b. said:


> This kind of stuff is answered most accurately by giving Eileen a call or an email, as she has exact counts on inventory. What I know is that the chassis panel order that we have coming in this week is about three (it's been a couple of hours since I checked and orders are really rolling in these days, so it's probably now more like five) short of the current orders. I would imagine that an order from two weeks ago will be covered by the incoming shipment. And all of the orders from today will be covered by the shipment of panels we hope to see in a couple of weeks.
> 
> Funny thing is we were pretty well caught up just a few weeks ago. It is really tough to predict when there will be a spike on a certain kit's orders. We sold so many Cracks in October that I kind of figured things would taper off a bit, but instead the orders keep pouring in. Not that I'm complaining!


 
  I ordered one last night only to read this today lol.
   
  This is going to be a looooong few weeks for me.


----------



## Hughkk

i want to ask if shipping need to be paid separately afterwards?
   
  since i am shipping these to asia, and when i checked out, they didn't charge me shipping?
   
  am i lucky or do i need to pay afterwards?


----------



## Doc B.

Yes Eileen will contact you with the shipping amount. There is a glitch in our shopping cart that won't calculate shipping outside the U.S., that is waiting for us to migrate to a new web host before we can fix it.


----------



## BmWr75

Hey Guys,
   
  I'm surprised by this, but the hum of the Crack with Beyerdynamic's new 250 ohm T70 is noticeable to me.  It is not obtrusive, but I can still hear it while the music is playing.  Have never noticed any hum with the Crack when using my 600 ohm DT770s.  I had to roll in a another tube amp that uses output transformers for listening to the T70s.
   
  Scott
   
  EDIT - the noise I'm hearing is probably not hum, but just a high noise floor due to the sensitivity of the T70s.  The noise does not get louder as the volume is increased.


----------



## WyldRage

The Crack is very sensitive to the tube used in it. If you have access to other tubes, try rolling them: you might find some with very low noise floor.


----------



## BmWr75

I've not tried any other tubes to try and reduce the noise floor.  Will do so sometime though, got lots of tubes to try.


----------



## lextek

Waiting for your Crack is the hardest part............


----------



## Hughkk

still waiting for m crack......
   
  want to ask what tube does it pair well? will the deafult ones do the job well?


----------



## Doc B.

We're still just waiting for the chassis panels to arrive from the laser cutter. They are supposed to have shipped Friday or today. As soon as they get here a large batch will be shipping, and there should be another shipment of panels arriving not too far behind them for more recent orders. Bear with us guys, during the Xmas season our orders just about triple and we're pedaling as fast as we can.


----------



## MilesDavis2

Quote: 





hughkk said:


> still waiting for m crack......
> 
> want to ask what tube does it pair well? will the deafult ones do the job well?


 


  The default ones are good enough. I suggest you enjoy them first so that you'll have a standard set. I am using a tungsol jan 5998/electro harmonics 12au7 alternating with an rca 12au7 clear top.  Very quiet.


----------



## tmd24

Great news! I've been waiting for this since early November. Hopefully, it arrives before Xmas. That would make for a fun project during the holidays. 
	

	
	
		
		

		
			





 
  
  Quote: 





doc b. said:


> We're still just waiting for the chassis panels to arrive from the laser cutter. They are supposed to have shipped Friday or today. As soon as they get here a large batch will be shipping, and there should be another shipment of panels arriving not too far behind them for more recent orders. Bear with us guys, during the Xmas season our orders just about triple and we're pedaling as fast as we can.


----------



## Doc B.

The laser cutter is running behind schedule this month and has pushed the delivery date to the end of the week. We have been packing up all the other parts of the kit orders in anticipation of the arrival of the panels so that we can ship all of the oldest orders and, in particular, orders that need to arrive by Xmas the minute the panels arrive.


----------



## Saturn

I really want to order a kit, but the DIY part gets me thinking. I have zero experience with soldering parts, and I am just worried if I screw up.
   
  How easy are the instructions to follow for someone that knows the minimal for electric circuitry. Has any first DIY'er manage to build the Bottlehead Crack kit by themselves?


----------



## Timbeh

Quote: 





saturn said:


> I really want to order a kit, but the DIY part gets me thinking. I have zero experience with soldering parts, and I am just worried if I screw up.
> 
> How easy are the instructions to follow for someone that knows the minimal for electric circuitry. Has any first DIY'er manage to build the Bottlehead Crack kit by themselves?


 


  i did, and besides easy, it was fun. Don´t get the building part get in the way, it´s sweet to plug your phones to an amp you built yourself


----------



## Doc B.

Quote: 





saturn said:


> Has any first DIY'er manage to build the Bottlehead Crack kit by themselves?


 


  Hundreds of first timers have built the kit.We designed it with them in mind.


----------



## Armaegis

The Crack was my first "real" project. Just look up some videos on soldering techniques, practice on a couple pieces of scrap wire, etc. You could get by on a $20 soldering iron kit from radio shack, but I'd recommend getting something in the $60-80 range, with temperature control preferably, and an extra tip or two (one chisel tip and one pencil tip should be enough for most projects).


----------



## LoweArt

It's a really easy kit to build even for a first timer and the instructions are spot on if you follow it to the letter.
   
  If you get stuck there's the Bottlehead forums and even Doc B. will come to the rescue if needed !
   
  I've got more expensive/elaborate amps than the CRACK, but I can't recommend this little GEM highly enough and if you have other skills like me you can even be a little more individual !


----------



## mosshorn

That's gorgeous enough of an idea, I might have to do that!
  
  Quote: 





loweart said:


> It's a really easy kit to build even for a first timer and the instructions are spot on if you follow it to the letter.
> 
> If you get stuck there's the Bottlehead forums and even Doc B. will come to the rescue if needed !
> 
> I've got more expensive/elaborate amps than the CRACK, but I can't recommend this little GEM highly enough and if you have other skills like me you can even be a little more individual !


----------



## LoweArt

I have a few of the stainless steel top plates that I had made left available for sale ( have sold 6 already ), so if you're handy with woodworking it
  wouldn't take you much to make up wood side panels to suit. PM if you're interested.


----------



## Gojo

Please send me a pm if anyone in the Los Angeles area is willing to assemble me a bottlehead crack for $50 or a $40 newegg gift card + $18 pre-paid amex card. I will of course be providing the amp kit.


----------



## Doc B.

Panels have arrived! A large stack of Cracks will be shipping today.


----------



## tmd24

Thanks for the update Doc. Holiday crack is on the way.
  Quote: 





doc b. said:


> Panels have arrived! A large stack of Cracks will be shipping today.


----------



## Draygonn

Got my Crack finished today.  Eileen was tons of help and sent parts I messed up or lost. Happy Holidays everyone!


----------



## lextek

Quote: 





draygonn said:


> Got my Crack finished today.
> 
> 
> 
> ...


 


   
  Looks great!  Mine should ship with the next batch.  Are those right angle adapters on the interconnects?


----------



## MilesDavis2

That looks great! Would love to hear your impressions.  Love mine and it does not have the speedball upgrade yet. Enjoy yours.
  Quote: 





draygonn said:


> Got my Crack finished today.
> 
> 
> 
> ...


----------



## qib

What about international shipping, voltage here in the UK is 230v i think. Would it be possible to use here?


----------



## Draygonn

lextek said:


> Are those right angle adapters on the interconnects?



Yes. They are Monster cables, the only right angle RCAs I could find. I also got a right angle power cable from monoprice. 




milesdavis2 said:


> That looks great! Would love to hear your impressions.  Love mine and it does not have the speedball upgrade yet. Enjoy yours.



Thanks. I'll do the Speedball upgrade next month. I'm liking what I hear, it sounds good with the planars.


----------



## tmd24

The site shows you can order the kit with a 240VAC power transformer for an extra fee. It's listed as an option in the buy section.
  
  Quote: 





qib said:


> What about international shipping, voltage here in the UK is 230v i think. Would it be possible to use here?


----------



## lextek

Thinking of relocating the RCAs and power cord to the rear of the amp.  Maybe the headphone jack to the front.  I know some components need to have contact to the chassis plate for ground.  Any issues with doing this?


----------



## genclaymore

Do they make tube's that has the colorless sound signature while being neutral? Now I don't have the tube amp' I just couldn't find the info on any tubes that exist with it.


----------



## mosshorn

@lextek, I don't see an issue coming from this, just make sure the connections stay the same.


Also, I was going to ask this on the Bottlehead forums but havent finished registration. I have a 6080 power tube in right now, is it easily replaceable with a 6SN7? I've read a couple things about needing to rewire, but others saying its a drop and go. If anyone can help, that would be awesome =)


----------



## Beefy

The 6SN7 is *not* suitable for the power tube. It can be used as a *driver* tube with an adapter.


----------



## mosshorn

Sorry, I meant 6AS7, I was at work when I posted and mixed the letters up :X


----------



## BmWr75

6AS7G tubes are a direct replacement in the Crack amp.  That is what I'm running now.


----------



## hodgjy

For most circuits using the 6080, you can use any of the following: 6AS7, 6AS7G, 6AS7GA, 5998, 5998, 7236, 2399, 6N13, 6N13P, and 6520.  Of course, check with the owner's manual or manufacturer first before dropping these tubes in.  Of these, I'd say the most "colorless" would be the Sylvania 7236.  On the opposite side, the RCA 6AS7G is very colored and warm.
  
  Quote: 





mosshorn said:


> @lextek, I don't see an issue coming from this, just make sure the connections stay the same.
> Also, I was going to ask this on the Bottlehead forums but havent finished registration. I have a 6080 power tube in right now, is it easily replaceable with a 6SN7? I've read a couple things about needing to rewire, but others saying its a drop and go. If anyone can help, that would be awesome =)


----------



## lextek

From the Bottlehead forum  Tubes for the Crack
   
  http://www.bottlehead.com/smf/index.php/topic,663.0.html


----------



## petercintn

Ordered the basic Crack and a couple of cheap tubes, a Tong Sol 12ua7 and a RCA 6as7g Black Plate just to get a feel of the sound, I've only heard a GE and a Raytheon lately (last 35 years or so!) and their 5670's, but don't each company have a house sound so to speak?
   
  I guess I have a month or so of waiting so at least I can read up on everything Bottlehead Crack.
   
  I have two receivers, a Pioneer and a new Yamaha. My DT990's sound great through both of them and I have been hesitant in buying the Crack, thinking it can't sound 2 to 300 dollars better, so why waste my money, but I had to see if I was missing anything so I pulled the trigger.  I sure hope it's better than the receivers.


----------



## hodgjy

I run my Dt990s through my Yamaha RX-V467 from time to time.  It sounds pretty darn good.  But, they reach their full potential on my tube amp.  You're gonna love your new tubes.
  
  Quote: 





petercintn said:


> I have two receivers, a Pioneer and a new Yamaha. My DT990's sound great through both of them and I have been hesitant in buying the Crack, thinking it can't sound 2 to 300 dollars better, so why waste my money, but I had to see if I was missing anything so I pulled the trigger.  I sure hope it's better than the receivers.


----------



## mosshorn

Quote: 





hodgjy said:


> I run my Dt990s through my Yamaha RX-V467 from time to time.  It sounds pretty darn good.  But, they reach their full potential on my tube amp.  You're gonna love your new tubes.


 


  Second this. I haven't run them thru a receiver, but the sound upgrade from my NFB-12's amp is a lot higher than I could have imagined.


----------



## mosshorn

Finished the other day, not too crazy but here's a couple pics


----------



## lextek

Ah you're killing me.  I ordered mine on 12/6.   Still waiting.  Have to get by with a non-tube sounding Valhalla.......
  Wish I had my old MG Head


----------



## mosshorn

All I can say is put your stain/coat on your finished base BEFORE you finish the circuit! I'm doing mine after (waiting for a poly coat to dry right now), and it sucks having to not listen to it!
   
  I almost dropped for the Valhalla, but I couldn't resist Crack, and now I'm hooked!


----------



## lextek

When I get my Crack.  I'm planning on relocating the headphone jack to the front plate and the RCAs and IEC to the rear.  I've had time to think about it.


----------



## Tequilasunriser

Quote: 





lextek said:


> Ah you're killing me.  I ordered mine on 12/6.   Still waiting.  Have to get by with a non-tube sounding Valhalla.......
> Wish I had my old MG Head


 


  Tell me 'bout it, I ordered mine on 12/7. The wait is killing me.
   
  I ordered the speedball upgrade separate, about a week. I hope they ship together. :S


----------



## hodgjy

Looks pretty awesome.  Congrats on it!
  
  Quote: 





mosshorn said:


> Finished the other day, not too crazy but here's a couple pics


----------



## mosshorn

Thank you 
   
   
  I also thought about putting my jacks like that lextek, it makes more sense, but for some reason I've grown fond of everything coming out of the top.
   
   
  Also found out today that the humming noise wasn't coming from my tubes, but actually my RCA jacks. When they are unplugged, completely silent. But when I plug the jacks in, even if the DAC isn't turned on, I get that static-y noise.
   
  Would my jacks not be properly grounded, or perhaps a crappy solder into the jacks?


----------



## hodgjy

Could be a ground loop.  Try running your DAC on a different circuit than the amp.  A different outlet on the same circuit would still cause a hum.  If you discover running the power from a different circuit fixes the problem, then it's a done deal.  If running the cords is a pain, you can get a $17 ground loop isolator from Radio Shack.
  
  Quote: 





mosshorn said:


> Also found out today that the humming noise wasn't coming from my tubes, but actually my RCA jacks. When they are unplugged, completely silent. But when I plug the jacks in, even if the DAC isn't turned on, I get that static-y noise.
> 
> Would my jacks not be properly grounded, or perhaps a crappy solder into the jacks?


----------



## mosshorn

Quote: 





hodgjy said:


> Could be a ground loop.  Try running your DAC on a different circuit than the amp.  A different outlet on the same circuit would still cause a hum.  If you discover running the power from a different circuit fixes the problem, then it's a done deal.  If running the cords is a pain, you can get a $17 ground loop isolator from Radio Shack.


 

 Thanks for the help! Tried it, didn't work. Just to see, I plugged my crappy turntable's RCA jacks into the amp, dead silent. Then I plugged the RCA plugs from my DAC in, but unconnected. Still no noise. But connecting them, noise. I'm going to find some other RCA plugs to see if my cables are the problem, if not, then I'm going to try resoldering.


----------



## tmd24

This is a question for those that painted the power transformer on their Crack. Did you use special paint or apply any primer? The reason I ask is I have some Rust-Oleum primer and flat black lying around. The directions say not to use on surfaces that exceed 200 degrees Fahrenheit or on galvanized metal. I'm not sure if the Crack's power transformer gets that hot. I'm assuming no, but wanted to ask before starting the paint process.


----------



## mosshorn

It doesn't get that hot (or at least I don't think it does)


----------



## tmd24

Awesome! Thanks for the input. Now I can start the paint process with more confidence.
  Quote: 





mosshorn said:


> It doesn't get that hot (or at least I don't think it does)


----------



## Doc B.

Rustoleum is fine. The trick is to clean the end bell really well before painting, as it has a slight sticky/oily coating on it to keep it from rusting. Naptha will do a pretty good job.


----------



## tmd24

Thanks Doc. I used some steel wool to remove the oil layer and polished it with compound. I'm going to blue the bell cap and paint the transformer.
  
  Quote: 





doc b. said:


> Rustoleum is fine. The trick is to clean the end bell really well before painting, as it has a slight sticky/oily coating on it to keep it from rusting. Naptha will do a pretty good job.


----------



## lextek

Oh yeah my Crack shipped.  I had all these great ideas relocating jack, different wood and stuff.  Now I just want to build it and listen.  Haven't been this excited about an amp in some time...


----------



## hodgjy

Sweet.  It would be awesome if you took pictures of it as you build it and post them here!
  
  Quote: 





lextek said:


> Oh yeah my Crack shipped.  I had all these great ideas relocating jack, different wood and stuff.  Now I just want to build it and listen.  Haven't been this excited about an amp in some time...


----------



## Draygonn

I started on my speedball upgrade. A small soldering tip is required for the pcb connections. For the crack I used a soldering gun with a big tip and I couldn't find replacement tips so I picked up another soldering iron (and some desoldering braid). I've been enjoying the crack with a TS5998 and the Fostex's the last two weeks. I've heard great things about the speedballed Crack/HD800 combo.


----------



## Tequilasunriser

Quote: 





lextek said:


> Oh yeah my Crack shipped.  I had all these great ideas relocating jack, different wood and stuff.  Now I just want to build it and listen.  Haven't been this excited about an amp in some time...


 


  I think mine may have shipped too. Did your order status change under your profile though? Mine still says "payment received" but I ordered before 12/8/11


----------



## mosshorn

I messed mine up today, at least I think I did XD headphone out give a nasty crackle buzz sound, idk if I messed up my RCA jacks or what


----------



## Doc B.

The shipping status info on the shopping cart is not functional. We are in the process of changing over new server that should allow some features like that, that have not been working, to work. You should get a tracking number by email the day your kit ships. If you are in the States it will be a UPS Quantum View notice. If outside the US it will be an email with your USPS tracking number. The best way to get updates on individual orders is to contact Eileen at queen at bottlehead dot com or call us M-F 10-6 PT, 206-451-4275.


----------



## Tequilasunriser

Quote: 





doc b. said:


> The shipping status info on the shopping cart is not functional. We are in the process of changing over new server that should allow some features like that, that have not been working, to work. You should get a tracking number by email the day your kit ships. If you are in the States it will be a UPS Quantum View notice. If outside the US it will be an email with your USPS tracking number. The best way to get updates on individual orders is to contact Eileen at queen at bottlehead dot com or call us M-F 10-6 PT, 206-451-4275.


 


  Ahh, thanks for the info Doc.


----------



## lextek

Quote: 





tequilasunriser said:


> Ahh, thanks for the info Doc.


 


   
  I got a UPS Quantum View email when mine shipped.


----------



## Tequilasunriser

Quote: 





lextek said:


> I got a UPS Quantum View email when mine shipped.


 

 Yup! I just checked my email and it accidentally got deleted. Very cool, can't wait to build my kit.


----------



## BmWr75

Hey Doc,
   
  I see people talking about running a 6SN7 adapter in place of the 12au7 on the Bottlehead forum.  Is this a plug and play adapter/tube combo?  Or, does the Crack have to be modified some to make it work?  If plug and play, where could I buy the adapter?
   
  I'd ask the question on the Bottlehead forum, but am waiting on my approval over there.
   
  Thanks,
  Scott


----------



## Doc B.

IDK, it's not something I have used and I don't know how it is wired with respect to the heater connections. It might be a lot cleaner to simply rewire the tube socket heater connections and plug in a 6CG7/6FQ7, which is electrically identical to the 6SN7.


----------



## lextek

Somebody suggested I post photos of my Crack build.  Here's the first
   
   

  yes I'm a little bored....


----------



## hodgjy

I did!  And that is ROFLMAO, actually.  Thanks for that.  
	

	
	
		
		

		
			




  
  Quote: 





lextek said:


> Somebody suggested I post photos of my Crack build.  Here's the first
> 
> 
> 
> yes I'm a little bored....


----------



## skeptic

Quote: 





bmwr75 said:


> Hey Doc,
> 
> I see people talking about running a 6SN7 adapter in place of the 12au7 on the Bottlehead forum.  Is this a plug and play adapter/tube combo?  Or, does the Crack have to be modified some to make it work?  If plug and play, where could I buy the adapter?
> 
> ...


 
   
  There is an adapter that several BH members bought from an ebay seller a while back - see this thread: http://www.bottlehead.com/smf/index.php?topic=2338.0
   
  My recollection is that some users reported a bit of hum when running 6sn7's, but I don't recall whether the conclusion was that it was the particular tubes of the adapter causing the issue.  Once you have a speedball in place, 12bh7's are another great alternative input tube.


----------



## Paganini Alfredo

I just bought a Crack amp from the for sale forum and have been doing some research on vacuum tubes and could just about hit myself repeatedly for wasting money on amps that aren't proper tube amps... So far in my hifi career I've listened to SS and hybrid amps such as the Schitt Lyr.
   
  But I know I love tubes and prefer tubes... the reason why I know this is because I love the sound that comes from tubed guitar amps. I suppose the reason I've avoided tube amps so far is that they seem a bit daunting, but not anymore. And I haven't really understood the way the electronics and circuits work inside. Which is also silly cause I have experience with electronics and went to electronic tech school for the military... so I understand how electricity works.
   
  Sheesh I just hope I've finally found the "sound" I've been looking for. I have some Senn HD600s that are inbound as well so I should be a happy camper at the end of the week.


----------



## hodgjy

I really think power tubes have a profound influence on sound, particularly from the 6AS7 family, which the Crack uses.  I have the Woo 3, which also uses the 6AS7 family.
   
  Have you looked at the 6AS7 tube rolling thread?  Lots of good info there. 
   
  I love the Tung-sol 5998 as my power tube.  But, other great alternatives include the Sylvania 7236, RCA 6AS7G, Tung-sol 6AS7G, and the GE 6AS7GA.
  
  Quote: 





paganini alfredo said:


> I just bought a Crack amp from the for sale forum and have been doing some research on vacuum tubes and could just about hit myself repeatedly for wasting money on amps that aren't proper tube amps... So far in my hifi career I've listened to SS and hybrid amps such as the Schitt Lyr.
> 
> But I know I love tubes and prefer tubes... the reason why I know this is because I love the sound that comes from tubed guitar amps. I suppose the reason I've avoided tube amps so far is that they seem a bit daunting, but not anymore. And I haven't really understood the way the electronics and circuits work inside. Which is also silly cause I have experience with electronics and went to electronic tech school for the military... so I understand how electricity works.
> 
> Sheesh I just hope I've finally found the "sound" I've been looking for. I have some Senn HD600s that are inbound as well so I should be a happy camper at the end of the week.


----------



## Beefy

Quote: 





hodgjy said:


> I really think power tubes have a profound influence on sound, particularly from the 6AS7 family, which the Crack uses.  I have the Woo 3, which also uses the 6AS7 family.


 

 For the resistor-loaded Crack and Woo 3, this is probably the case. For a Speedballed Crack though, with the CCS-load, differences between power tubes is substantially reduced.
   
  The 5998 is good, but you really don't miss much with a bog-standard $15 RCA 6AS7G.


----------



## hodgjy

I really like the RCA, but all of mine are noisy.  I've gone through too many to keep searching.  It's a shame, they really are good sounding tubes.
  
  Quote: 





beefy said:


> For the resistor-loaded Crack and Woo 3, this is probably the case. For a Speedballed Crack though, with the CCS-load, differences between power tubes is substantially reduced.
> 
> *The 5998 is good, but you really don't miss much with a bog-standard $15 RCA 6AS7G.*


----------



## Paganini Alfredo

Quote: 





hodgjy said:


> Have you looked at the 6AS7 tube rolling thread?  Lots of good info there.


 

 Nope, thanks. Not that I know a thing yet, but I read that the Tungsol is a good tube to have, no?


----------



## hodgjy

Many of us love it, but tube rolling is fun because you can decide what you like.  Plus, since the 5998 has been hunted to extinction, they are hard to get and are expensive.  Other cheaper options have become more favorable and sound very good.
  
  Quote: 





paganini alfredo said:


> Nope, thanks. Not that I know a thing yet, but I read that the Tungsol is a good tube to have, no?


----------



## lextek

It's here!  I decided not to relocate the RCAs and headphone jack.  Just build it "stock" at first.  Hard to believe this pile of parts will make music.............


----------



## BmWr75

I read somewhere that one vacuum tube does the same work as 20-30 discrete, solid state parts.
  
  Quote: 





lextek said:


> It's here!  I decided not to relocate the RCAs and headphone jack.  Just build it "stock" at first.  Hard to believe this pile of parts will make music.............


----------



## hodgjy

I would believe it.  The insides of my Woo are orders of magnitude more simple than solid state amps I've opened up.  There's all kinds of widgetry inside solid state amps.
  
  Quote: 





bmwr75 said:


> I read somewhere that one vacuum does the same work as 20-30 discrete, solid state parts.


----------



## lextek

Just started working on my Crack kit today. Not to sound to corny, butnImam justnhaving a blastnbuilding this thing. So far I've justngot the top plate, transformer and endbell painted.  Used Rustoleum hammertone and it looks great.  Mounted the hardware on the plate and assembled the wood base.  Very, nice woodworking.  I'm sure this "simple" box is often  overlooked.  Alder is a beautiful wood.
      At first I was intimidated about the electrical part.  But after looking at the manual I feel very confident.  Awesome instructions.  I'll post some pictures later.  Thanks Doc.


----------



## Quake1028

I freaking love how this amp looks.


----------



## mosshorn

Quote: 





quake1028 said:


> I freaking love how this amp looks.


 


  Second.


----------



## lextek

Spend most of this snowy, day building the Crack.  It sounds great.  Hd600/Crack=special combo. The voltage check was fun.


----------



## hodgjy

Looking great!
  
  Quote: 





lextek said:


> Spend most of this snowy, day building the Crack.  It sounds great.  Hd600/Crack=special combo. The voltage check was fun.


----------



## tdogzthmn

The last piece you need is the Cardas bottlehead cable with right angle termination.  It opens up the detail more, and adds some tightness to the bass.  A worth while upgrade in my opinion.
  
  Quote: 





lextek said:


> Spend most of this snowy, day building the Crack.  It sounds great.  Hd600/Crack=special combo. The voltage check was fun.


----------



## Tequilasunriser

I'm working on the base of mine right now. Just got done with 2 coats of stain. Looks pretty sweet!
   
  I can't start work on the electrical portion of the amp until I get the top plate painted but the temperatures in the Midwest haven't been favorable lately. The spray paint can says it needs to be at lease 50 degrees Fahrenheit. 
   
  Anyone know what could possibly happen if I spray paint the top plate in, say, 30 degree weather?


----------



## lextek

Quote: 





tdogzthmn said:


> The last piece you need is the Cardas bottlehead cable with right angle termination.  It opens up the detail more, and adds some tightness to the bass.  A worth while upgrade in my opinion.


 


  What cable is this you are talking about?  Headphone?  I have Moon Audio Blue Dragon and a Smurf Cardas for the HD.


----------



## lextek

Quote: 





tequilasunriser said:


> I'm working on the base of mine right now. Just got done with 2 coats of stain. Looks pretty sweet!
> 
> I can't start work on the electrical portion of the amp until I get the top plate painted but the temperatures in the Midwest haven't been favorable lately. The spray paint can says it needs to be at lease 50 degrees Fahrenheit.
> 
> Anyone know what could possibly happen if I spray paint the top plate in, say, 30 degree weather?


 


   
  Tried spraying another project in thengarage when it was cold.  Not very, good results.  I painted my plate in the basement withmwindows open and a fan.


----------



## mosshorn

He's talking about the power cable Bottlehead sells. It looks nice 
   
   
  Speaking of which, absolutely beautiful build lex!


----------



## Doc B.

Quote: 





mosshorn said:


> He's talking about the power cable Bottlehead sells. It looks nice
> 
> 
> Speaking of which, absolutely beautiful build lex!


 


  No, he's talking about an HD600/650 cable we used to sell which was a Cardas cable with a right angle Neutrik TRS plug on it made for us by DIY Cable. I keep one on my 600s. The Cardas cable is a very nice upgrade. Andy Regan of Cardas brought by a balanced cable to try out on the HD800s we had at the last RMAF and I thought it was the best sound we heard from them during the show.


----------



## lextek

Quote: 





doc b. said:


> No, he's talking about an HD600/650 cable we used to sell which was a Cardas cable with a right angle Neutrik TRS plug on it made for by DIY Cable. I keep one on my 600s. The Cardas cable is a very nice upgrade. Andy Regan of Cardas brought by a balanced cable to try out on the HD800s we had at the last RMAF and I thought it was the best sound we heard from them during the show.


 

 Decided to keep the headphone jack where it is.  Ordered a right angle TRS connector to swap on to my Moon-Audio Blue Dragon (DIY) cable.  Easier.


----------



## tdogzthmn

Quote: 





doc b. said:


> No, he's talking about an HD600/650 cable we used to sell which was a Cardas cable with a right angle Neutrik TRS plug on it made for us by DIY Cable. I keep one on my 600s. The Cardas cable is a very nice upgrade. Andy Regan of Cardas brought by a balanced cable to try out on the HD800s we had at the last RMAF and I thought it was the best sound we heard from them during the show.


 


  Yes Doc has the same cable but mine is plain grey without the teckflex jacket.  I would like to know where I can acquire one of the balanced cardas cables for the HD800 which I plan to use it with the future purchase of a smack.  Hopefully it's not too over priced, I was able to get the Cardas cable for the HD600 at $150.  Most cables are priced too high and its not overly complicated to build your own.


----------



## Doc B.

I would imagine the usual Cardas dealers like Music Direct carry the HD800 clear cable. You can also purchase HD800 style connectors from Parts Connexion and build your own. IIRC they are $50 the pair. By the time you purchase premium connectors for both ends, and premium wire, and good quality heat shrink and Tech Flex and solder and then spend the time it takes to terminate the cables in such a way as to make them truly rugged you start to see why some cables go for a fair penny.


----------



## tdogzthmn

For those interested in an affordable cable for the HD600 with right angle termination, this company was where I purchased mine.
   
  http://www.diycable.com/main/product_info.php?products_id=515


----------



## hy fi

Lextek I see we share another hobby, RC heli's if that drop cloth is any indication. I'm not advanced enough for the Align T-Rex stuff yet though...


----------



## lextek

Quote: 





hy fi said:


> Lextek I see we share another hobby, RC heli's if that drop cloth is any indication. I'm not advanced enough for the Align T-Rex stuff yet though...


 


  Yup started withe the E-Flite Blade coax then a Trex 450.  Last one was a CY Rave.


----------



## lextek

Finally got around to swapping out the connector on the Blue Dragon cable for a right angle one.  Much cleaner look with the Crack.


----------



## kongmw

Just got the email stating that the Crack kit price is going up in a week. Maybe I should just order a second one as a back up? LOL


----------



## lextek

Quote: 





kongmw said:


> Just got the email stating that the Crack kit price is going up in a week. Maybe I should just order a second one as a back up? LOL


 


   
  Yup me too.  Love my Crack.  Speedball going up too.  Think I'll order soon. Anyway the Crack is worth it at almost any price.


----------



## Draygonn

kongmw said:


> Maybe I should just order a second one as a back up? LOL




MonoBlock Cracks! Muahhahhaha


----------



## lextek

Just placed my Speedball order.   Taking my Crack to a new level!


----------



## Ultrainferno

I have to admit not having read the full thread but what is wrong with their customer service? I've emailed them 4 times in the last 5 months and haven't gotten one single reply, it makes it kind of hard to order (when needing something special). I hope this is just the case for me alone, seems everyone is very happy with Bottlehead (which is good)
   
  And now with the price increase, I doubt I'll ever get one at all. Bummer


----------



## liamstrain

How much do they expect the price to rise?
   
  Edit - found the note on the Bottlehead page.


----------



## Doc B.

Quote: 





ultrainferno said:


> I have to admit not having read the full thread but what is wrong with their customer service? I've emailed them 4 times in the last 5 months and haven't gotten one single reply, it makes it kind of hard to order (when needing something special). I hope this is just the case for me alone, seems everyone is very happy with Bottlehead (which is good)
> 
> And now with the price increase, I doubt I'll ever get one at all. Bummer


 


  I'm sorry you have not received a response. As I don't know what your email address is it's difficult for me to try to work out what is happening. Perhaps a PM would get through to us.


----------



## Draygonn

ultrainferno said:


> I have to admit not having read the full thread but what is wrong with their customer service? I've emailed them 4 times in the last 5 months and haven't gotten one single reply, it makes it kind of hard to order (when needing something special). I hope this is just the case for me alone, seems everyone is very happy with Bottlehead (which is good)
> 
> And now with the price increase, I doubt I'll ever get one at all. Bummer




I've always had prompt replies from Eileeen. She was very helpful when I needed replacement parts. 

Anyone who wants a Crack has until the 12th to get it at the 219 price. Still good value at 279 but not as much of steal. This is one hell of an amp.


----------



## mosshorn

I emailed for a replacement part and didn't receive a reply, but I also called so I just kind of assumed that's what happened. They are a great bunch of people though, so don't lose faith, it's probably some email junk 
  Quote: 





ultrainferno said:


> I have to admit not having read the full thread but what is wrong with their customer service? I've emailed them 4 times in the last 5 months and haven't gotten one single reply, it makes it kind of hard to order (when needing something special). I hope this is just the case for me alone, seems everyone is very happy with Bottlehead (which is good)
> 
> And now with the price increase, I doubt I'll ever get one at all. Bummer


----------



## kongmw

Quote: 





ultrainferno said:


> I have to admit not having read the full thread but what is wrong with their customer service? I've emailed them 4 times in the last 5 months and haven't gotten one single reply, it makes it kind of hard to order (when needing something special). I hope this is just the case for me alone, seems everyone is very happy with Bottlehead (which is good)
> 
> And now with the price increase, I doubt I'll ever get one at all. Bummer


 

 I can almost guarantee you that it's just your case alone, as I'd never seen anyone complain anything about Bottlehead, and their customer service has always been beyond excellent. That I can attest myself.
   
  Easiest way is to give them a call during their business hours.


----------



## Ultrainferno

Quote: 





kongmw said:


> I can almost guarantee you that it's just your case alone, as I'd never seen anyone complain anything about Bottlehead, and their customer service has always been beyond excellent. That I can attest myself.
> 
> Easiest way is to give them a call during their business hours.


 

 I'm contacting the good sir from Bottlehead via PM right now!
  Giving a call isn't always easy when there is like a 10 hour time difference or so


----------



## kongmw

Quote: 





ultrainferno said:


> I'm contacting the good sir from Bottlehead via PM right now!
> Giving a call isn't always easy when there is like a 10 hour time difference or so


 


  ahhh... Sorry I missed the upper right corner on your post: "Location: Country of chocolate and beer"


----------



## liamstrain

My tax refund came quicker than I expected, so I could place the order before the price boost. Huzzah. 
   
  I'll be joining you all soon.


----------



## Ultrainferno

Just a quick post to say everything finally is sorted out with Bottlehead. Doc B and queen are really nice!
  Now let's hope the Cracks get here soon. Not sure if my customs dpt will like reading "Crack" on the Invoice


----------



## lextek

Little quiet at this Crack house.  Figured out how to post photos from iPad.  Here are some showing the right angle connections.
   
   
  .


----------



## hy fi

"Page not found" error.
  Quote: 





lextek said:


> Little quiet at this Crack house.  Figured out how to post photos from iPad.  Here are some showing the right angle connections.


----------



## Ultrainferno

Quote: 





lextek said:


> Little quiet at this Crack house.  Figured out how to post photos from iPad.  Here are some showing the right angle connections.


 

  
  http://i44.photobucket.com/albums/f21/lextek/2012/126ef3cb.jpg
  http://i44.photobucket.com/albums/f21/lextek/2012/58730821.jpg


----------



## hy fi

Quote: 





ultrainferno said:


> http://i44.photobucket.com/albums/f21/lextek/2012/126ef3cb.jpg
> http://i44.photobucket.com/albums/f21/lextek/2012/58730821.jpg


 


  I'm dumb


----------



## BmWr75

Quote: 





hy fi said:


> I'm dumb


 


  From many of the posts I read on Head-Fi every day you are in good company.


----------



## Ultrainferno

So we placed our order for 4 or 5 amps the week before the price increase and transfered the money. Since then, no single word from Bottlehead. I'm sure they're very busy but we don't even have any clue about our order (2 other emails since then have been left unanswered too). Is it ok (special requests)? When will it be transfered? I'm really having bad luck communicating with them, Doc B was very nice before by PM, guess I'll contact him again on here.
   
  Anyone else order weeks ago and hasn't heard anything?


----------



## liamstrain

From what I can tell, they got a huge influx of orders (including my order too) and are backed up. As I understand it, they only just got the Christmastime orders fulfilled... so I expect a they will be sending out soon. 
   
  Delivery status page:
  "Most recent update to this list - 2/27/12 - we have just returned from a week away. We will be working through the weekend to catch up on orders. "
  http://www.bottlehead.com/et/deliverystatus.htm


----------



## Ultrainferno

Quote: 





liamstrain said:


> From what I can tell, they got a huge influx of orders (including my order too) and are backed up. As I understand it, they only just got the Christmastime orders fulfilled... so I expect a they will be sending out soon.
> 
> Delivery status page:
> "Most recent update to this list - 2/27/12 - we have just returned from a week away. We will be working through the weekend to catch up on orders. "
> http://www.bottlehead.com/et/deliverystatus.htm


 


  I just saw. thanks for the link. It also says:
   
  [size=x-small]Crack OTL Headphone amp [/size] [size=x-small]orders thru 1/9 shipped - more shipping this week[/size]


----------



## Doc B.

Yes, we were buried by another Xmas sized rush right before the price increase. Actually that was a typo on the status page about our return, we have been back for two weeks and working 7 days a week to catch up. Crikey, even_ I_ have been kitting parts! 
	

	
	
		
		

		
		
	


	




 As of today we have the backlog down to around 75 kits. Another shipment of tubes should be coming in this week and we should be getting another large group of Crack kits out in the next week or so. Thanks to everyone for the enthusiastic support and your patience while we work to get everyone's kit to them.


----------



## lextek

Speedball upgrade kit arrived today.  Hope to get it put together tomorrow.  Hard to imagine it sounding better.


----------



## liamstrain

Thanks for the update, Doc! The bittersweet problems of success 
   
  Can't wait to get crackin', as it were.


----------



## Twinster

Lucky the one that got in before the price increase. It's now $279 + $125 = $404 before finishing products. Now the WOO 3 doesn't seem that expensive. Anyone tried both with 600 ohm Beyer? Comments would be appreciate.


----------



## Draygonn

I'm finally getting around to finishing the speedball. I picked up a tiny clamp from Fry's for $5 to hold the boards while I work on them.


----------



## Doc B.

Just a quick update to note that we got a good number of kits out in the past two days and I have updated the delivery status to reflect this. We have moved from where we were on Monday - the second week of January's orders - to currently packing the very end of January's orders. Waiting for a few more bits to arrive and we should be able to do another good sized packing session that moves us into shipping February orders next week.


----------



## Doc B.

The Woo Audio products are very nice and I enjoyed meeting Jack at RMAF. Do bear in mind when comparing that the Woo 3 circuit is much closer to the stock $279 Crack kit circuit, not the upgraded circuit that includes the cascode constant current sources.


----------



## Twinster

Thank you for the reply back Doc.  I know you make good product. It's my fault that I miss the sale before the increase. I'll wait a bit longer. I currently have a pretty decent tube amp made in Canada (My country 
	

	
	
		
		

		
		
	


	




) by Mappletree Audio Desing. It's very good with Grado headphones and fair very well with my 600 ohm T1 but I would not know until I try the Crack how much better an OTL is with the T1.
   
   
  Quote: 





doc b. said:


> The Woo Audio products are very nice and I enjoyed meeting Jack at RMAF. Do bear in mind when comparing that the Woo 3 circuit is much closer to the stock $279 Crack kit circuit, not the upgraded circuit that includes the cascode constant current sources.


----------



## lextek

Finished up the Speedball.  Another fun build.  Very, nice upgrade.  Noticed better bass extension and seperation.  Really sounds great.  Overall a "cleaner bigger" sound.  If that makes sense.


----------



## skeptic

Quote: 





twinster said:


> Lucky the one that got in before the price increase. It's now $279 + $125 = $404 before finishing products. Now the WOO 3 doesn't seem that expensive. Anyone tried both with 600 ohm Beyer? Comments would be appreciate.


 
   
  A few comparative comments for you:
   
I have a Woo 3 in my office, and a modded Crack w/ speedball in my main rig at home - both running well regarded tubes (specifics in profile).  While I certainly still enjoy my Woo (on a daily basis, in fact), the Crack is the better amp.  I found this to be true even when my Crack was still in stock form.  It is simply a more detailed and dynamic amp, with a better defined bottom end. 
   
I haven't had a chance to hear the 600 ohm Beyers with either amp, but the above holds true with all of my high impedance cans: HD800's, 650's and DT880 (250 ohm). 
   
This is no knock on Woo Audio.  I've heard every amp in their lineup, excluding the new reference monoblocks, and they make wonderful gear - especially their high end stuff!  The Crack is just an absolute steal even after the minor price bump.  Also, FWIW, when considering cost, nice nos input tubes for the Crack (like clear tops and bugle boys) can be had fairly cheaply on ebay.  Premium tubes for the WA3, like the 7308 pq's I'm running, are selling for pretty absurd amounts these days.


----------



## lazybill

I just checked out your profile and I'm wondering if by chance you tried the 7236 in your Woo3 in your Crack just to see if there is much difference.  I just ordered a 7236 for the crack as a 5998 is impossible to find at a decent price.  I found a 421a but it was costing more than the crack.
   
  Thanks Bill


----------



## skeptic

Bill - I did try it, and the 7236 sounds really nice in the crack.  I still prefer 5998's by a slight margin (in both of my amps), but I agree the pricing has gotten absurd.  On the other side of the coin, there are also headfier's who strongly prefer the sound of the 7236: http://www.head-fi.org/t/393811/woo-wa2-tube-rolling-recommendations/135
   
  I can't imagine ever cashing out for a 421a.  For that kind of money, you could probably get your hands on a GEC 6as7g - which is supposedly the real holy grail of the family of tubes (according to veterans like skylab).
   
  All that said, I did most of my b-socket tube rolling before putting in my speedball.  I know Beefy (and maybe others?) have commented that the differences between power tubes are much less audible once your unit is receiving constant current.


----------



## Beefy

Quote: 





lazybill said:


> I just checked out your profile and I'm wondering if by chance you tried the 7236 in your Woo3 in your Crack just to see if there is much difference.  I just ordered a 7236 for the crack as a 5998 is impossible to find at a decent price.  I found a 421a but it was costing more than the crack.
> 
> Thanks Bill


 

 The 7236 is the computer rated version of the 5998*A*, which you may be able to get at a better price.


  Quote: 





skeptic said:


> I can't imagine ever cashing out for a 421a.  For that kind of money, you could probably get your hands on a GEC 6as7g - which is supposedly the real holy grail of the family of tubes (according to veterans like skylab).


 

 The 421A is just a hand-picked 5998 anyway. I can't ever imagine that they would be worth the price premium.


----------



## Twinster

Thank you Skeptic for your feedback on these two amplifier.  I'm probably going to sell my MAD Ear+ Purist HD with my gizzilion tubes. I don't think I'll go back to Grado sound. Ever since I got the T1 I can't get use to the lack of soundstage anymore. Crack & Speedball will be coming home. 
	

	
	
		
		

		
			




   
  Can I dare asking if anyone have compared the Crack/Speedball to the Decware CSP-2 & Woo 2?
  Quote: 





skeptic said:


> A few comparative comments for you:
> 
> I have a Woo 3 in my office, and a modded Crack w/ speedball in my main rig at home - both running well regarded tubes (specifics in profile).  While I certainly still enjoy my Woo (on a daily basis, in fact), the Crack is the better amp.  I found this to be true even when my Crack was still in stock form.  It is simply a more detailed and dynamic amp, with a better defined bottom end.
> 
> ...


----------



## lazybill

Thanks guys for the come back.  No I wouldn't spring for a 421a, just happen to see it while looking for a 5998.  On the other hand I guess I didn't read far enough on tube spec.  I took the 7236 to be the computer 5998 not the 5998a.  I can find plenty of 5998a's.  Oh well live and learn.  I guess it will probably still be better than the stock 6080(actually the stock tubes sounded pretty good til' you hear something better).
   
  Thanks again for the info.
  Bill


----------



## Mak333

Quote: 





lextek said:


> Finished up the Speedball.  Another fun build.  Very, nice upgrade.  Noticed better bass extension and seperation.  Really sounds great.  Overall a "cleaner bigger" sound.  If that makes sense.


 

  
  lextek - Just got mine installed tonight as well.
   
  I've had the Crack for about a year and a half now.  Speedball came in from Bottlehead on Wednesday.  Got it installed tonight, didn't bother with voltage checks yet (too excited to listen). All I know is that the lower frequencies, while do not overpower, do have more presence and fill out tracks well, as well as adding more detail in the low range.
   
  Leaving technical descriptions aside and in summary, I _definitely_ find every track in my 'playlist' much more enjoyable to listen to with Speedball.


----------



## Draygonn

Well I almost got the speedball finished today. A few voltage checks were off(1 and 5), the LEDs on the little boards did not light, and the turn on voltage spike hit 30. Gonna touch up the little boards tomorrow in the daylight and get everything runnin'.


----------



## johnman1116

Whats the word on helping hands vs vise? From what I understand, helping hands would be a better choice for cables. What im wondering is if there is any down side to using helping hands on a circuit board. Are the little clips conductive, potentially damaging the board. etc/
   
  I always thought they were more expensive so i was leaning toward helping hands but now that i found the holy "$5 vise", things got interesting 
  
  Quote: 





draygonn said:


> I'm finally getting around to finishing the speedball. I picked up a tiny clamp from Fry's for $5 to hold the boards while I work on them.
> 
> 
> Spoiler: Warning%3A%20Spoiler!


----------



## Mak333

Quote: 





johnman1116 said:


> Whats the word on helping hands vs vise? From what I understand, helping hands would be a better choice for cables. What im wondering is if there is any down side to using helping hands on a circuit board. Are the little clips conductive, potentially damaging the board. etc/
> 
> I always thought they were more expensive so i was leaning toward helping hands but now that i found the holy "$5 vise", things got interesting


 

 Just finished mine last night.  The boards aren't very complex, and I don't think you could damage anything unless you're cutting through connections.  (They are pretty robust).  I used a smaller locking pliers that had enough weight to it so the board wouldn't move around with too much force applied when soldering.  Just grab the ends of the board where you won't be soldering and you're good to go.  A vice like johnman1116 has may be a "better" option, but definitely not necessary, especially since the 3 circuit boards require minimal soldering and do not take long at all.


----------



## Mak333

I should add that I found the most complex part of the Speedball assembly was removing Crack components and installing it into the circuit.  I don't know about others, but I find solder joints that hold multiple connections can be a pain.
   
  I'd say Speedball (the entire assembly) took me 5 hours to complete, and the only soldering experience I've had is building the Crack in 2010.  I didn't need any other tools outside of what I used for the Crack... might want a solder wick or some type of remover if it comes to that.


----------



## lextek

Quote: 





johnman1116 said:


> Whats the word on helping hands vs vise? From what I understand, helping hands would be a better choice for cables. What im wondering is if there is any down side to using helping hands on a circuit board. Are the little clips conductive, potentially damaging the board. etc/
> 
> I always thought they were more expensive so i was leaning toward helping hands but now that i found the holy "$5 vise", things got interesting


 

 I put some heat shrink over the clips.  You could also use some silicone tubing I guess.


----------



## lextek

Quote: 





mak333 said:


> I should add that I found the most complex part of the Speedball assembly was removing Crack components and installing it into the circuit.  I don't know about others, but I find solder joints that hold multiple connections can be a pain.
> 
> I'd say Speedball (the entire assembly) took me 5 hours to complete, and the only soldering experience I've had is building the Crack in 2010.  I didn't need any other tools outside of what I used for the Crack... might want a solder wick or some type of remover if it comes to that.


 


  I thought soldering the lugs of the heatsink to the PCBs was a pain.  I was afraid of overheating the board.


----------



## captouch

lextek said:


> I thought soldering the lugs of the heatsink to the PCBs was a pain.  I was afraid of overheating the board.




I was most nervous around the small red LED's because they seemed so fragile. And on Speedball, I soldered some wires through the wrong holes and had to des older with wick. That was stressful as well as desoldering is something I'm not very good at.


----------



## Mak333

Quote: 





lextek said:


> I thought soldering the lugs of the heatsink to the PCBs was a pain.  I was afraid of overheating the board.


 

 lextek - I found that moving the iron around helps the solder flow to all areas, especially on those large lugs.  Same goes for soldering a PC board... I rarely let the iron stay still because solder just didn't want to flow to all open cavities.  But if you think about it... the heatsink is conducting most of that heat at that point so I doubt much heat was being put through the board.


----------



## johnman1116

Hey, really cool idea.
  thanks,
  
  Quote: 





lextek said:


> I put some heat shrink over the clips.  You could also use some silicone tubing I guess.
> 
> 
> 
> ...


----------



## Draygonn

Is there a way to test the LEDs to see if I've blown them out?


----------



## lextek

draygonn said:


> Is there a way to test the LEDs to see if I've blown them out?



I know my Fluke 87 meter has a diode setting. Never used it.


----------



## skeptic

Quote: 





draygonn said:


> Is there a way to test the LEDs to see if I've blown them out?


 

 I damaged a diode on my A-socket while putting in the stand-offs for my speedball, and had some similar questions at the time.  
   
  If you don't have a diode setting on your meter (like me), you can still cause a good diode to light up by measuring resistance across the diode (in the right orientation), with your meter on the most sensitive scale.  Per what I have read in various places, it is possible to damage a good diode if your meter is not set to one of its highest sensitivity resistance settings.  Also note - even when your leads are oriented correctly, causing the LED to light up, resistance will, within a second, max out on your meter.  More details are discussed in my bottlehead troubleshooting thread here: http://www.bottlehead.com/smf/index.php?topic=1825.0  
   
  Hope this helps!


----------



## Doc B.

Quote: 





draygonn said:


> Is there a way to test the LEDs to see if I've blown them out?


 

 Sure. A diode measures very high (i.e. near infinite) resistance in one direction and the HLMP-6000 measures around 1500 ohms in the other direction. Just use your DMM on the ohms setting to measure, swapping the test leads for each direction. In some cases the battery in the meter will make the LED light up, in other cases it won't, so that is not a useful indicator.
   
  There is a lot of tech support info for Crack kit builders on the Bottlehead Forum. 
   
http://www.bottlehead.com/smf/index.php/board,24.0.html


----------



## skeptic

Quote: 





doc b. said:


> Sure. A diode measures very high (i.e. near infinite) resistance in one direction and the HLMP-6000 measures around 1500 ohms in the other direction. Just use your DMM on the ohms setting to measure, swapping the test leads for each direction. In some cases the battery in the meter will make the LED light up, in other cases it won't, so that is not a useful indicator.
> 
> There is a lot of tech support info for Crack kit builders on the Bottlehead Forum.
> 
> http://www.bottlehead.com/smf/index.php/board,24.0.html


 

 The interesting part of this, in my experience, was that when my meter was set to a scale that would have allowed me to measure 1500 ohms, it would not cause any of my diodes (the good or the damaged) to light up.  However, if I had it set to either the highest, or second highest, sensitivity - it would light up all of my good diodes, but it would not light up the damaged one.  Sure enough, when I replaced the diode that would not light up with a new one from BH, all of the voltages in my crack + speedball were right on the mark.
   
  There is clearly some nuance to what goes on when measuring resistance across diodes...  For example, this resource suggests that the measured resistance will "will vary substantially with the particular ohmmeter used to take the reading."  http://www.allaboutcircuits.com/vol_3/chpt_3/2.html
   
  Edit: this thread makes for a pretty good read about measuring LED's and their non-linear nature, if anyone else finds this topic at all interesting: http://cr4.globalspec.com/thread/4943/Resistance-of-LED-s  (See in particular the posts by Masu)


----------



## Doc B.

That is why many DMMs have a diode checking setting. If yours has one, using that setting that is the best way to measure.


----------



## Draygonn

Thanks for the diode checking info guys. The LEDs check out fine but I can't find what's wrong so she'll go back in the closet for a while. Fortunately I don't need it to be completed until the summer.


----------



## lextek

Came across a post on the Bottlehead forum about using the Crack as a preamp. I had to ty it. Made up a cable to go from headphone jack to my little SS amp. Used some Kimber speaker cable I had. Must say the Crack/Speedball makes a nice little preamp/linestage not sure which is the correct term. Pretty cool.


----------



## nikongod

Quote: 





lextek said:


> Came across a post on the Bottlehead forum about using the Crack as a preamp. I had to ty it. Made up a cable to go from headphone jack to my little SS amp. Used some Kimber speaker cable I had. Must say the Crack/Speedball makes a nice little preamp/linestage not sure which is the correct term. Pretty cool.


 

 A line stage is a preamp that does not include a phono-stage. 
   
  The term preamp is commonly misused.


----------



## peanuthead

Does anyone else find gain on Crack to be a little too high?  Using my CDP with the typical output of 2V, I can't move the volume knob past 7-8 o'clock before it's too loud on HD650/HD800.
  I've resorted to connecting Crack to the preamp output of my HeadAmp GS-1 in order to "attenuate" the source signal.  Still sounds very good...


----------



## RonO

Yep, I find the POT a bit quick for my tastes.  I set my volume knob to point at 6 o'clock when muted, and 7 or 8 is already to or beyond what I need for normal listening. I've been reading the bottlehead forums, and it seems others are either replacing the POT with different models that can help, or using resistors on the line to the POT to reduce the signal.  My pot has a bit of an imbalance at low volume. I have enough volume swing with my older tunes that have high dynamic range, but new music with 4-6 db or less of dynamic range gets loud so quick I can't make the volume low enough for my preferred listening level.


----------



## Beefy

You have a few options to tame the gain, mostly involving pre-attenuation on the input.
   
  In my case, I replaced the stock 100k pot with a 50k TCK-2CP2511 in series with a 50k resistor, giving approx 6dB of attenuation. The TKD also has excellent channel matching and sounds better than the stock pot. You can also use a resistor divider on the input, as detailed here: http://www.goldpt.com/mods.html


----------



## peanuthead

Thanks Beefy.  Is the TDK a drop-in replacement or did you have to make some changes to the panel?


----------



## Beefy

It required drilling of the panel to accommodate the locking pin.


----------



## peanuthead

Thanks.
  
  Quote: 





beefy said:


> It required drilling of the panel to accommodate the locking pin.


----------



## kongmw

Interesting. I have my Crack connected to my Rega RP1 through a V-LPS phono and mostly feel that I need about 10-11 o'clock for good listening level on my HD650. Granted, I mounted the pot so that the mute position is somewhere between 6 and 7.


----------



## Doc B.

Yes, the volume setting is very dependent upon the source level as well as headphone sensitivity, and both of those are all over the map. The beauty of DIY is you can tailor the amp's gain with input attenuators if you have more than you need.


----------



## peanuthead

I got my Crack/Speedball recently expecting some cheap fun with good amount of coloration, but I'm seriously surprised by how good this amp sounds.  Much more neutral than I had anticipated, with excellent control and detail.  This is a great amp period.  Crack and HD800 are making some sweet sweet music right now...thanks and kudos to the folks at Bottlehead.


----------



## skeptic

Quote: 





peanuthead said:


> This is a great amp period.  Crack and HD800 are making some sweet sweet music right now...thanks and kudos to the folks at Bottlehead.


 

 Amen to that.  It is a great combo!


----------



## matti620

I'm considering buying a used one. Is it a good idea with tube amps?
   
  What transformer should I get to replace the built-in 120VAC with a 240VAC ?


----------



## telecaster

Crack amp is using 6080 tube, and as the 6AS7G are both tubes that are very musical, dynamic, and cheap! My La Figaro 339 is using 6AS7G in dual mono configuration and it has even more authority, clarity and good sound than Crack! You should also check out other 6AS7G/6080 tube amp out there, they are gorgeous and tube rolling is affordable and fun!


----------



## Ultrainferno

Quote: 





telecaster said:


> Crack amp is using 6080 tube, and as the 6AS7G are both tubes that are very musical, dynamic, and cheap! My La Figaro 339 is using 6AS7G in dual mono configuration and it has even more authority, clarity and good sound than Crack! You should also check out other 6AS7G/6080 tube amp out there, they are gorgeous and tube rolling is affordable and fun!


 


  Do you have a crack and a 339? On what is the statement based?
  My crack is on its way (and I have the 339)


----------



## telecaster

It is pure hypothesys, double power supply vs single in all the other gear I tested including mostly power amps and loudspeakers. Soz didn't want to bash you new acquisition! It seems Crack is great buy for the price!


----------



## Ultrainferno

Quote: 





telecaster said:


> It is pure hypothesys, double power supply vs single in all the other gear I tested including mostly power amps and loudspeakers. Soz didn't want to bash you new acquisition! It seems Crack is great buy for the price!


 


  No problem, I just bought it to test it with my HD650, that's all


----------



## telecaster

I should have refrein myself doing such a comment, promess I will watch my mouth next time!


----------



## GeorgeNapalm

peanuthead said:


> I got my Crack/Speedball recently expecting some cheap fun with good amount of coloration, but I'm seriously surprised by how good this amp sounds.  Much more neutral than I had anticipated, with excellent control and detail.  This is a great amp period.  Crack and HD800 are making some sweet sweet music right now...thanks and kudos to the folks at Bottlehead.




Can you compare your Crack with GS-1 as to how they play with HD800?


----------



## peanuthead

They are both very good with HD800...
  
  Quote: 





georgenapalm said:


> Can you compare your Crack with GS-1 as to how they play with HD800?


----------



## GeorgeNapalm

Quote: 





peanuthead said:


> They are both very good with HD800...


 


 Thanks! I'm waiting for my HD800 to arrive and plan to build the Crack very soon. We'll see how it compares with Lyr...


----------



## hedphonz

Quote:  





> Crack and HD800 are making some sweet sweet music right now...thanks and kudos to the folks at Bottlehead.


 
   
  thats exactly what i heard - i have the hd800's and very keen to explore the tube sound - and the more i research this amp the more i realise that for the money you cant go wrong


----------



## telecaster

I don't believe it's such a good match, Crack being DIY and "ugly" looking (not soundwise) is not a good match for that beauty of HD800 phones. I believe you would always want to upgrade later just because of the ergonomics and looks of that unit.
  Spending that much on the phones and so little on the amp will always keep one wanting for "more".


----------



## BmWr75

Quote: 





telecaster said:


> I don't believe it's such a good match, Crack being DIY and "ugly" looking (not soundwise) is not a good match for that beauty of HD800 phones. I believe you would always want to upgrade later just because of the ergonomics and looks of that unit.
> Spending that much on the phones and so little on the amp will always keep one wanting for "more".


 
   
  That is a form over function statement if there ever was one.
   
  There are some real deals in life, the Crack is one of them (with the right high impedance cans)!!


----------



## Yoga Flame

Quote: 





telecaster said:


> I don't believe it's such a good match, Crack being DIY and "ugly" looking (not soundwise) is not a good match for that beauty of HD800 phones. I believe you would always want to upgrade later just because of the ergonomics and looks of that unit.
> Spending that much on the phones and so little on the amp will always keep one wanting for "more".


 
   
  I disagree. There definitely have been very beautiful Crack builds. It's up to you to decide how far you want to take it. And it's always an option to splurge on top of the line components. Go wild with a premium stepped attenuator, boutique caps, or even commission a skilled craftsperson to make you a custom enclosure in the material, finishing and even shape of your choice. It's only inexpensive if you want it to be.


----------



## Draygonn

Haha, calling the Crack ugly and the HD800's beautiful made me laugh.


----------



## ben_r_

Quote: 





draygonn said:


> Haha, calling the Crack ugly and the HD800's beautiful made me laugh.


 
   
  Beauty, like many other things around here as well, is in the eye of the beholder. I agree, the Crack is ugly and the HD-800 is gorgeous. Takes all kinds.


----------



## matti620

Some do want their amp (and headphones) to have a crude non-plastic look.


----------



## twizzleraddict

"Ugly" as in saves the customer a great deal of $$ instead of a nicely designed and CNC'ed chassis to make it look commercially acceptable. Either way, this is irrelevant as it's about how the damn thing sounds. And that's what matters in the end.
   
  You can always change the chassis it comes with for something much more pleasing to the eye anyway.


----------



## hedphonz

I have this romantic vision of me working at a bench soldering all night, a craftsman at work with all the best tools and making amazing amps. 
   
  Reality is I will spend big $ on " the best" tools, end up with a dogs breakfast and never use the tools again lol
   
  I think buying built is the best option for me
   
   
  EDIT: im not sure i expressed myself properly - i mean im ordering a bottlehead built as knowing me i would spend a fortune on tools, muck it up and end up not using them again. Wasnt meaning to troll


----------



## telecaster

Ah ok then...


----------



## liamstrain

Beauty is in the eye of the beholder. I actually like the simplicity and honesty of Bottlehead's designs. Sure there are "prettier" tube amps out there, but there is a grace in their "form follows function" aesthetic. 
   
  *shrug*


----------



## telecaster

IME when I solder things myself especially in anything audio things I always ended wondering if I didn't screw up a solder or if it would have sound better if I used silver solder and teflon wire with better cap and so on..


----------



## telecaster

Oh well I need to shut this computer down and breath some fresh air, what is it about fora these days..


----------



## captouch

liamstrain said:


> Beauty is in the eye of the beholder. I actually like the simplicity and honesty of Bottlehead's designs. Sure there are "prettier" tube amps out there, but there is a grace in their "form follows function" aesthetic.
> 
> *shrug*




I agree and like simplicity and customizability of Crack, just the way it is. No two (built as DIY) are exactly alike, which is cool to me. Pop in a 5998 and vintage 12AU7 and aesthetics get even better. 

Not to mention what a great value and sound it provides.


----------



## telecaster

.


----------



## Bones13

The Bottlehead "theme" of a metal plate (common ground) on a wood chassis is the classic DIY type of enclosure.  Inexpensive, the common ground is a safety feature.  It also makes it easy to open and close during construction, troubleshooting, and upgrading.  This enclosure can be constructed with masking tape, some glue, and sandpaper and varnish.  No special tools needed.  A kitchen table with good light and your soldering iron, solder and wire stripper/clipper will get the job done.  Screwdriver and pliers to tighten some bolts.
   
  Sure these kits don't have custom metal enclosures, or polished walnut burl wood facings.  The whole point of these kits is to make really great gear affordable to an average DIY person.  The instructions with the kits make anyone who can do a bit of soldering make a super set of 300b monoblocks, or the OTL Crack.  As stated above, you are welcome to upgrade any part of the kit that you want to, or feel comfortable doing.  Experimentation is encouraged.
   
  I have seen folks putting the bottlehead kit guts into metal enclosures, or the wooden frame substituted with all sorts of pretty woods, or more complex structures.  Tube rolling, Capacitor rolling, fancy inputs, outputs, attenuators.  Lights, knobs etc, whatever the creative juices of the builder allow/demand.
   
  Hard to beat these kits IMO.  Heck, you can do headphone listening to the S.E.X. kit, both the headphone amps, and even with the Paramount 300b/2A4 monoblocks.  A very headphone friendly set of DIY kits.  Also with a great forum of folks to help, and display their creative skills.
   
  Just remember, beauty, and sound are in the eye/ear of the beholder.  I have listened to my HD650s with many amps,  Hard to beat the Crack with Speedball and Cap upgrades.


----------



## Armaegis

Quote: 





hedphonz said:


> I have this romantic vision of me working at a bench soldering all night, a craftsman at work with all the best tools and making amazing amps.
> 
> Reality is I will spend big $ on " the best" tools, end up with a dogs breakfast and never use the tools again lol
> 
> ...


 
   

 I shall commission elves to craft the finery of the circuits, while the dwarves will build a mighty chassis of marble and steel... or y'know, just ask Bottlehead to build it. That works too


----------



## skeptic

Just came across this review of the crack, posted on headfonia's FB page: https://www.facebook.com/note.php?note_id=387463131298390
   
  Nice to see that someone else agrees with my assessment: "I tried the Crack with the HD800 and it is phenomenal. "  (posted in the comments section)


----------



## mackat

What is the best decently priced 6as7g tube on eBay?


----------



## mackat

I only can afford one


----------



## RonO

Quote: 





mackat said:


> I only can afford one


 
   
  In my case, I tried a couple of used RCA 6AS7G's, while they sounded good they were exceptionally microphonic, and buzzy.  They work well if you can wait about 2 hours to get them HOT.  I grew sick of this, and got some new "old" russian 6H13C's, for $6 each.  These came is original packaging which was a treat in itself.  These are dead silent, warm up quick and are quite pleasing to my ear.  The boxes show these as 1984 manufacture, and do appear in every way to have been unused. All these tubes have subtle differences in sound, but they all sound good.


----------



## runswithaliens

Quote: 





beefy said:


> You have a few options to tame the gain, mostly involving pre-attenuation on the input.
> 
> In my case, I replaced the stock 100k pot with a 50k TCK-2CP2511 in series with a 50k resistor, giving approx 6dB of attenuation. The TKD also has excellent channel matching and sounds better than the stock pot. You can also use a resistor divider on the input, as detailed here: http://www.goldpt.com/mods.html


 
   

 If you have a DAC with adjustable volume out, do you lose anything sound quality wise if you just attenuate the volume from the DAC before sending to the amp?


----------



## Beefy

Yeah, that works as well.
   
  But it makes little sense to use more than one volume control is series. Better to use an appropriate volume control from the start.


----------



## Ultrainferno

Just got a nos GEC 6AS7G and TS 6AS7G for the Crack, can't wait for it to get here!


----------



## liamstrain

It lives! 
   
  After being without a Crack for a few months (returned a loaner, and no time to build my kit) - I finished wiring up mine this evening. 
   
  Resistance check is good. Tubes light up and it plays music (through cheapo test headphones)!
   
  I still need to sit down and do the voltage check to make sure nothing is amiss before it enters real service, but I'm optimistic. I'll be very happy to get that sweet sound back into my regular listening station.


----------



## matti620

I need my Crack! I ordered it two weeks ago and haven't even received a delivery confirmation...


----------



## liamstrain

Quote: 





matti620 said:


> I need my Crack! I ordered it two weeks ago and haven't even received a delivery confirmation...


 
   
  Check their status page - they did have a huge backlog for a while, on shipping out. 
  http://www.bottlehead.com/et/deliverystatus.htm


----------



## Ultrainferno

Mine took almost 2 months to ship


----------



## kongmw

lol they're backed up for almost 2 months....
  i remember the excruciating wait, but in the end, it was all worth it


----------



## Doc B.

Yes, between a special offer and a price increase we were slammed with orders this winter and we have been playing catch up as our vendors deliver our ever increasing orders. Right now we are awaiting the next shipment of chassis panels, which we hope to see in the next week. At that point we should be catching up quite a bit more.


----------



## Windsor

Using the Sennheiser HD 800, has anyone compared the Bottlehead Crack and the Bottlehead Crack with the Speedball upgrade?


----------



## liamstrain

I don't recall the Crack I had been borrowing getting quite so warm as the one I just completed does. The top plate and power tube base, especially. 
   
  All the resistance and voltage checks out, though some of the voltage readings did trend high. 1/5/7/9 were all about 20% high. Everything else was dead on or less than 10-15% high.
   
  Sounds great with only a slight background hiss. Just checking to make sure nothing is wonky.


----------



## liamstrain

update:
   
  Doc B confirmed on the Bottlehead forum that all was well, and it's doing what it should with the 6080 tube.


----------



## wullymc

Just got my headphones...DT880s...now just waiting for my Crack....almost 5 weeks now....


----------



## Twinster

Quote: 





wullymc said:


> Just got my headphones...DT880s...now just waiting for my Crack....almost 5 weeks now....


 
  Can't wait to get your impression on the Crack. Hopefully you can bring it to our next meet 
	

	
	
		
		

		
			





. I want to try my T1 with it.


----------



## Paganini Alfredo

as far as high impedance phones go... this is the best amp i'd gather.


----------



## GeorgeNapalm

Quote: 





paganini alfredo said:


> as far as high impedance phones go... this is the best amp i'd gather.


 
  Your profile says you have Schiit Lyr . Did you compare Lyr and Crack on HD800?


----------



## Jidonsu

I actually just picked up a used factory assembled Crack w/ Speedball from the FS here.  My setup will be Matrix Mini-i --> Crack ---> HD650. I just bought the HD650 as well and it'll show up separately with the amp next week.  I have to say I'm pretty excited.  I kind of wished I had built the amp myself after seeing all the upgrade possibilities.  I'm tempted to pick up a bare kit this summer to learn with and mod.


----------



## liamstrain

Quote: 





paganini alfredo said:


> as far as high impedance phones go... this is the best amp i'd gather.


 
   
  Best? No - there are many that will outperform it in just about every measure (the Zana Deux, for instance). What the Crack offers, however, is great value. Fantastic performance, especially for the price. You have to spend a good chunk of change to outperform it.


----------



## MilesDavis2

Quote: 





wullymc said:


> Just got my headphones...DT880s...now just waiting for my Crack....almost 5 weeks now....


 
  Congrats on the DT880.  The wait will worth it.


----------



## MilesDavis2

Quote: 





jidonsu said:


> I actually just picked up a used factory assembled Crack w/ Speedball from the FS here.  My setup will be Matrix Mini-i --> Crack ---> HD650. I just bought the HD650 as well and it'll show up separately with the amp next week.  I have to say I'm pretty excited.  I kind of wished I had built the amp myself after seeing all the upgrade possibilities.  I'm tempted to pick up a bare kit this summer to learn with and mod.


 
  My crack is stock and I am very happy with it.


----------



## mackat

milesdavis2 said:


> Quote:
> 
> 
> 
> ...




I really like mine with my HD650's!


Ben aka MacKat


----------



## MayorSimpleton

I'm very serious considering popping my DIY cherry and ordering a Crack - to the point where I'm already considering finish options.
   
  Has anybody powdercoated their top-plate and transformer cover?  Powercoating doesn't like too much heat IIRC and I was wondering if the Crack generates enough heat to worry the powdercoat?
   
  N


----------



## Paganini Alfredo

Quote: 





georgenapalm said:


> Your profile says you have Schiit Lyr . Did you compare Lyr and Crack on HD800?


 
  Nah, If i'm gonna bust out my Lyr it's for my LCDs. Crack is much better for the HD800s.
  Quote: 





liamstrain said:


> Best? No - there are many that will outperform it in just about every measure (the Zana Deux, for instance). What the Crack offers, however, is great value. Fantastic performance, especially for the price. You have to spend a good chunk of change to outperform it.


 
  When I say best that's exactly what i mean... taking into consideration price and performance. You get absolutely phenomenal sound out of the crack. I have no interest or inclination to even try out something like the zana deux. I mean why??? I'd rather spend that kind of money towards a better amp for my speakers.


----------



## Doc B.

Quote: 





mayorsimpleton said:


> Has anybody powdercoated their top-plate and transformer cover?  Powercoating doesn't like too much heat IIRC and I was wondering if the Crack generates enough heat to worry the powdercoat?
> 
> N


 
   
  Yes you can powdercoat both and they will handle the heat. We have done quite a few over the years. Be careful to clean the transformer bell end very thoroughly as it has a sort of oily/sticky coating to keep the raw steel from rusting. Running it in the dishwasher will usually strip it off.


----------



## MayorSimpleton

Quote: 





doc b. said:


> Yes you can powdercoat both and they will handle the heat. We have done quite a few over the years. Be careful to clean the transformer bell end very thoroughly as it has a sort of oily/sticky coating to keep the raw steel from rusting. Running it in the dishwasher will usually strip it off.


 
  Lovely - thanks for the tips.  I put my order in today - looking forward to it.
   
  N


----------



## Jidonsu

I just received a used Crack with the Speedball upgrade.  I have some background noise coming through the left channel even with the volume turned down and inputs disconnected. The right channel is silent.  Is this normal?  Thanks.


----------



## BmWr75

No, it is not normal.
   
  Turn the amp off.  Pull both tubes and then reinstall them.  It is a long shot, but easy to try.


----------



## Jidonsu

Thanks.  I tried that. No luck.  I tried cleaning the pins on the output tube a bit, no luck there either.  Get new tubes? Haha. 
  
  This is my first tube amp, so I'm not completely familiar with how it works.  After powering on, the the left channels comes through first after a few seconds, followed by the right channel a couple seconds after that.


----------



## Yoga Flame

Not really related, but with tube amps it's best to leave the headphones unplugged for 30 seconds or so while the amp warms up.


----------



## liamstrain

what kind of background noise? 
   
  hiss? or hum?


----------



## Jidonsu

It's a hiss, like white noise.  I read on the Bottlehead forum that it can happen with some tubes, especially if the tubes are fairly new.  I ordered some 6AS7G to replace the 6080.  If that helps, great.  If not, we'll see.


----------



## liamstrain

That is true - the tubes need some time for the cathodes to form up... and the hiss *should* decrease. If you are getting it in one channel and not the other - it is possible that you have a tube that is in not great shape, and one triode is uneven.


----------



## BmWr75

Quote: 





yoga flame said:


> Not really related, but with tube amps it's best to leave the headphones unplugged for 30 seconds or so while the amp warms up.


 
   
  Really????  I can think of no reason this would be advantageous.  Letting the amp warm up with the cans connected and the volume turned down is probably better for the amp.  Many folks say a tube amp should never be powered up with no load on it.......this is probably an old wives tale though.


----------



## Ultrainferno

It actually depends on the amp, no?. I think even Bottlehead recommended turning it on/off without headphones plugged in, because of the voltage? spikes.
  Correct me if I'm wrong, I'm no techie.


----------



## Beefy

Quote: 





bmwr75 said:


> Really????  I can think of no reason this would be advantageous.  Letting the amp warm up with the cans connected and the volume turned down is probably better for the amp.  Many folks say a tube amp should never be powered up with no load on it.......this is probably an old wives tale though.


 
   
  Just because you can't think of reasons doesn't mean there are none. OTL amps can have large spikes of DC when the tubes start conducting. With low impedance phones it dissipates quickly but it can translate into a pretty high current.
   
  And the amp does have a load even with no phones connected; a couple of resistors. These bleed away the DC if no phones are connected.


----------



## BmWr75

I admit that me being wrong is a very real possibility. 
   
  Maybe Doc from Bottlehead with chime in with some facts.


----------



## Beefy

Quote: 





bmwr75 said:


> I admit that me being wrong is a very real possibility.
> 
> Maybe Doc from Bottlehead with chime in with some facts.


 
   
  It isn't a possibility, and Doc's input is not required - you _are_ wrong.


----------



## Doc B.

I don't think any of this is reason enough to get feathers ruffled. None of our gear needs to be connected to a load to run. There is a bit of DC offset at startup of a Crack, which is why we have a bleeder resistor across the output. It's probably not necessary in the  majority of situations (and honestly I forget sometimes myself), but we do recommend waiting to plug in headphones until after the amp has warmed up for 30 seconds or so.


----------



## BmWr75

Thanks for the clarification Doc B.  I had never hear this before and have always had my HPs plugged in when turning the Crack on.  It has never caused any problems that I'm aware of so far.  Most of my HPs are 600 ohm that I use with the Crack.  Will try to remember this in the future.
   
  I have 4-5 other tube amps I use with headphones, all with output transformers though, and have always kept the HPs plugged into them to as they are powered on and off.  That was the basis for my original response to the question.


----------



## Doc B.

There could be an amp design that would be better off with a load on the output at start up. One situation that comes to mind would be an amp with a fair amount of global negative feedback, that might need an output load to maintain stability. We don't make our amps that way and they all run fine without anything attached to the output, but naturally I can't speak about other manufacturer's designs.


----------



## Ultrainferno

My crack is finally finished! 3 months after ordering


----------



## liamstrain

Oh. That GEC is a good looking tube too... 
   
  How does she sound?


----------



## Ultrainferno

I expected more to be honest, but it was NOS so I should give it some time. For the moment i'm using a pre burned in 6080 TS with excellent results together with a RCA clear top.


----------



## telecaster

Nice! So you finally get to hear it! You use it with your senns?
   
  Quote: 





ultrainferno said:


> My crack is finally finished! 3 months after ordering


----------



## Ultrainferno

Yes, only with the Sennsheiser HD650. It's quite nice, but overall I prefer the 339. The soundsignatures are different, the Crack is the clearer and quicker one but the 339 just is more pleasant to listen to, it's the better one. More later


----------



## telecaster

Now I wonder how HD800 will sound with 339!


----------



## Armaegis

Quote: 





jidonsu said:


> I just received a used Crack with the Speedball upgrade.  I have some background noise coming through the left channel even with the volume turned down and inputs disconnected. The right channel is silent.  Is this normal?  Thanks.


 
   
  Check the LEDs (turn off the lights if you have to). Do all of them light up?


----------



## Jidonsu

I found the problem that caused the hiss.  I replaced the 6080 with a RCA 6AS7G, no luck.  Swapped the EH 12AU7 with another one (Mullard) and the hiss instantly went away.  Now I can't seem to take my headphones off.


----------



## liamstrain

Hurrah!


----------



## Jidonsu

And I'm already ready to upgrade. Haha.


----------



## liamstrain

Heh.
   
  I've now got a mid 60's Dumont/Sylvania on the way to replace my EH 12AU7 (and bidding on some mullard long plates) - it never stops... what upgrade are you thinking of? Different tubes? different amp? Other?


----------



## Jidonsu

Quote: 





liamstrain said:


> Heh.
> 
> I've now got a mid 60's Dumont/Sylvania on the way to replace my EH 12AU7 (and bidding on some mullard long plates) - it never stops... what upgrade are you thinking of? Different tubes? different amp? Other?


 
   
  I'm thinking of upgrading to the long plates too, but I don't really know the differences I should be expecting.  I picked up these short plates Mullards for $9.50 shipped on ebay since my only intention was to solve the hissing problem.  My HD650s are also fairly new, so I should probably listen to them for a while first.  I am tempted to upgrade to an even better set of headphones though.....that's just the way I am.


----------



## liamstrain

Decided the Mullards were getting too pricey. But the Dumont is here - quieted down the amp entirely - much blacker background than the EH provided. I'm very happy with this input tube so far. 
   
  edit... 
  Whoompf. HD600 and Listening to a recording of Liszt's transcription of Beethoven's 7th symphony - played by Csaba Kiraly. Holy crap. 
   
  Just wow. The piano notes just dance out from black velvet, pirouette in my head, and float away. Really lovely and engaging.


----------



## .Sup

Hey guys I would like to order the Crack today as my first DIY project. My question is is my solder iron good enough for the job. Especially the speedball upgrade seems to have really small parts and so I worry if the tip is too thick though I have made several cables and never had any issues with that. The iron I use is this: http://www.amazon.co.uk/Weller-Sp25L-Soldering-Iron-230V/dp/B0009VX232
  thanks!


----------



## Doc B.

You should have no trouble building the kit if you have soldered cables successfully. In fact I think making properly constructed cables is one of the trickier jobs. The 25W iron is a little on the small side but will do the job. We recommend a 40w iron, though the 25W iron could come in very handy if you decide to add the Speedball kit, as it will be easier to use on the PC boards.


----------



## .Sup

Quote: 





doc b. said:


> You should have no trouble building the kit if you have soldered cables successfully. In fact I think making properly constructed cables is one of the trickier jobs. The 25W iron is a little on the small side but will do the job. We recommend a 40w iron, though the 25W iron could come in very handy if you decide to add the Speedball kit, as it will be easier to use on the PC boards.


 
  Thank you very much!


----------



## ztsen

Finally bought a dynamic headphone that I like after so long, unbox Crack and setup to listen again. Sweet, it still makes my new headphone, PSB sings!


----------



## ztsen

ultrainferno said:


> Yes, only with the Sennsheiser HD650. It's quite nice, but overall I prefer the 339. The soundsignatures are different, the Crack is the clearer and quicker one but the 339 just is more pleasant to listen to, it's the better one. More later




Dont sound the best is ok, at least it looks great! Lol.


----------



## c540

I started a thread with another photo, but here is my bottle head crack with speed ball Chassis that I  made from aluminum and stainless steel.
  I already had the Crack board from another chassis.


----------



## liamstrain

Well, that might help mitigate some of the heat. 
   
  Nice looking build.


----------



## McGrathSunny

I just checked out the Bottlehead website and saw they’re having a special promotion where you get a free Speedball upgrade kit when you purchase a Crack kit ($279). It’s only for the first 25 orders and I don’t know how fast they sell their stuff but if you are looking for a great tube amp that is fairly simple to put together, you should check it out. http://www.bottlehead.com/store.php?crn=224&rn=442&action=show_detail. I put together my first Crack a few years ago and got the Speedball upgrade recently. I love it for my Sennheiser HD 650s and Beyerdynamic DT 880 Premiums. The Speedball upgrade is definitely noticeable and also helps keep the unit cooler. Anyways, thought I’d share this as it’s a fun kit to build and very popular among Head-fiers.


----------



## twizzleraddict

^ In for one. Don't know when I'll get time to build it but hope to get some downtime from work next year to do some soldering iron slinging.


----------



## captouch

Great deal - love mine


----------



## hipcat

Got mine soldered up today and alls I have to say is WOW it sounds good!! and I have the speedball upgrade to do yet
	

	
	
		
		

		
			




  .


----------



## OJNeg

Quote: 





hipcat said:


> Got mine soldered up today and alls I have to say is WOW it sounds good!! and I have the speedball upgrade to do yet
> 
> 
> 
> ...


 
   
  Looks great! I imagine you varnished the wood pieces that came with the kit? How'd you treat it exactly?


----------



## hipcat

I didn't use the wood that came with the kit it's oak I had. I mixed dark walnut and mahogany stain to get the color and than put 6 coats of deft (lacquer) on it


----------



## liamstrain

Holy output caps, batman.


----------



## MilesDavis2

Don't you just love the crack and the HRT combo?


----------



## hipcat

Yes the hrt a great match with the crack best sounding setup I've had yet.


----------



## telecaster

Those are MKP 100µF caps?


----------



## hipcat

those are solen 100uF  400v caps.


----------



## johnman1116

I just got done with the resistance checks. I open my tube boxes so I can start the voltage checks and notice this. Seems like the part came off of the Octal tube, the center piece in the shape of a cylinder with a little bump.
  Wondering if this is still usable or not.
   
  Thanks,


----------



## BmWr75

Quote: 





johnman1116 said:


> I just got done with the resistance checks. I open my tube boxes so I can start the voltage checks and notice this. Seems like the part came off of the Octal tube, the center piece in the shape of a cylinder with a little bump.
> Wondering if this is still usable or not.
> 
> Thanks,


 
   
  Yes, the tube is still useable, you just have to make sure you install it correctly.  The broken off piece had an alignment tab on it so the tubes would only fit into the socket one way.
   
  I'd try super glueing or hot glueing the pin back on the base.  Hopefully you can tell how to align it correctly.


----------



## johnman1116

All my readings check out but a few.
   
  A6 - 150
  A8 - 12.6
   
  B1 - 150
  B3 - 150
   
  I would post on the BottleHead Forums but my account is still waiting approval. Not sure if anyone can help me here with my current problems though.


----------



## GeorgeNapalm

I placed the order on Crack yesterday and I'm wondering -  how long was the wait recently?


----------



## hipcat

Took mine about 8 weeks but it was worth the wait!


----------



## liamstrain

They seem to be almost caught up on shipments - it may not be that long.


----------



## Mak333

I posted this earlier on BH Forums, but I'll post here for duplicity-sake!
   
  [size=12pt]*UPDATE (6/23/12):*[/size]

 Was getting anxious to get the capacitors off of the ground from the adhesive cable tie mounts not bonding well when the chassis gets hot.  Found some #10 bolts and nuts (1/2" length, but wanted 1/4") and bolted the mounts to the underside.  The cable ties were not easy threading through the mounts, now with a screw there.  Would have been easier with a smaller bolt/nut.  I threw the aluminum knob on again too.  Overall it wasn't too bad, but I wish I used a different mounting system to make the job easier.  I'm borrowing the interconnects from a friend, who also sold me the KECES DA-151 DAC (USB) at a generous price.


----------



## .Sup

Hey guys just a quick question. Well pictures should explain better.
   

   

   

   
  The rear tube socket isn't straight when I tighten the screws, its like I should use the washer but I am worried I might need it later.


----------



## liamstrain

As long as it holds securely, I wouldn't worry too much. As far as I know, there is no reason that both sides of the bracket MUST touch the plate. You might try loosening the other side slightly, to balance it a bit. As long as it is secure, and so is the component strip, you're in good shape.


----------



## Doc B.

Yeah, if you bottom the soft aluminum bracket against the chassis on both sides you will actually bend it and create a situation where the socket can eventually start to wiggle around. The bracket needs to have a little space to properly clamp the socket to the plate. 
   
  Sometimes what seems to be less than perfect is the way something works best. As another example I sometimes see people making perfect sharp right angle bends in their wiring. It looks very neat, but bending a wire at a sharp angle can create fractures in the internal crystal structure that are not particularly desirable.


----------



## Draygonn

Finished my Speedball upgrade. Magical.



I accidentally swapped the 237 and 31.6 ohm resistors. Took a while to figure that out. The small board LEDs were not lighting up and I did a lot of re-soldering in an attempt to find the culprit. My eyes could not tell those resistors apart, the multimeter had no such problems.

Hi .Sup, glad to see you are joining the Crack family.


----------



## .Sup

Thanks for the replies guys. I ended up using that washer anyway, it was a bit wiggly but a tightened the screws and it looks really good now, hopefully I won't need that washer. I started soldering.
   
  Thanks for the welcome Dray! I got an email from customs asking me if I can describe what these parts are for, maybe they suspected they were bomb parts hehe


----------



## ValentinHogea

I'm quite intrigued about this amp... How does the Crack w/ Speedball compare with La Figaro 339. Especially regarding HD650.
   
  Tx,


----------



## Ultrainferno

Quote: 





valentinhogea said:


> I'm quite intrigued about this amp... How does the Crack w/ Speedball compare with La Figaro 339. Especially regarding HD650.
> 
> Tx,


 
   
  The 339 is the smoother, warmer sounding and the more tube sounding amp of both. The Crack is faster, clearer and has a better defined bass. Bass depth is better on the 339.
  The HD650 is great with both, If you want to clear up the HD650 go for the Crack, if you like it's darkness go for the 339.


----------



## .Sup

I finished building and everything checked out except the resistance to the right RCA connector is 85 (ohms?) compared to 90 like it should be on the left RCA. When listening, the left channel sounds audibly louder, not by much but still enough to perceive it. I also measured from the potentiometer and its still 86. Any ideas?


----------



## Beefy

Quote: 





.sup said:


> I finished building and everything checked out except the resistance to the right RCA connector is 85 (ohms?) compared to 90 like it should be on the left RCA. When listening, the left channel sounds audibly louder, not by much but still enough to perceive it. I also measured from the potentiometer and its still 86. Any ideas?


 
   
  Yeah, that isn't helpful. You need to tell us exactly what you are measuring - where from, where to, and the correct units.
   
  I suspect you are measuring ground to signal, through the pot. In that case, the difference in resistance of 5kohm doesn't make a difference. The pot is a voltage divider, and the absolute resistance doesn't matter.


----------



## liamstrain

Quote: 





> When listening, the left channel sounds audibly louder, not by much but still enough to perceive it.


 
   
   
  That could easily be a tube issue (triode imbalance on either tube) - if it is mostly noticable at low volumes (or when the volume pot is turned low due to high sensitivity headphones), it could be the Pot ... I don't think a 5kohm difference at the RCA's would cause that. Maybe Doc B will have an idea though.


----------



## .Sup

liamstrain said:


> That could easily be a tube issue (triode imbalance on either tube) - if it is mostly noticable at low volumes (or when the volume pot is turned low due to high sensitivity headphones), it could be the Pot ... I don't think a 5kohm difference at the RCA's would cause that. Maybe Doc B will have an idea though.



The front tube looks like new but I have never seen a tube glow so little, there is only a tiny part glowing. That power tube looks like it was made 50 years ago being very dirty, pins need cleaning and a lot of the metal portion has oxidized. It was difficult to insert it.



The sound is OK though.


----------



## liamstrain

the little input tubes are not a very "glowy" type - that's normal.


----------



## .Sup

liamstrain said:


> the little input tubes are not a very "glowy" type - that's normal.



thanks for the info Liam. Could the power tube cause this? All the measurements I took checked out.


----------



## Draygonn

.sup said:


> The front tube looks like new but I have never seen a tube glow so little, there is only a tiny part glowing. That power tube looks like it was made 50 years ago being very dirty, pins need cleaning and a lot of the metal portion has oxidized. It was difficult to insert it.


If you are planning on keeping the stock tubes, clean the pins with deoxit. I wouldn't worry about the input tube glowing just a little, that is normal with the tubes I have used.


----------



## .Sup

draygonn said:


> If you are planning on keeping the stock tubes, clean the pins with deoxit. I wouldn't worry about the input tube glowing just a little, that is normal with the tubes I have used.



Thanks Draygonn. I haven't decided if I will invest in a better tube yet, at this point I'm not even sure if I will install the SpeedBall upgrade even though I have it sitting on my desk. Would really like to remedy the problem first.


----------



## liamstrain

Have you posted on the Bottlehead forum?


----------



## .Sup

liamstrain said:


> Have you posted on the Bottlehead forum?



Haven't yet, will do so tomorrow Liam.


----------



## .Sup

Guys before I make a post on the Bottle forum I thought I'd buy a tube just to rule that out. What is a good place to buy a tube suitable for this amp?
thanks


----------



## hipcat

If you haven't read through this thread yet I would say read through it there is some info on tubes here I would also go to the bottlehead forum there is a thread on tube rolling in the crack area and read through it you'll get an idea on what tubes people like. I use ebay alot but I try to buy used tubes, they are cheaper and I havent got a bad tube yet, and you get a feeling for if you like that tube and if it goes bad you won't mind paying more money for a nos tube.


----------



## .Sup

hipcat said:


> If you haven't read through this thread yet I would say read through it there is some info on tubes here I would also go to the bottlehead forum there is a thread on tube rolling in the crack area and read through it you'll get an idea on what tubes people like. I use ebay alot but I try to buy used tubes, they are cheaper and I havent got a bad tube yet, and you get a feeling for if you like that tube and if it goes bad you won't mind paying more money for a nos tube.



Okay thanks hipcat. Should I look at replacing both tubes?


----------



## .Sup

Hello guys, I just got the tubes and guess what - channels are now balanced! I am so proud of myself right now as this was my first DIY project and I was really thorough when building and refused to admit to myself I could have done something wrong. I am ecstatic right now as I got the tubes a day before I go on vacation till the end of the month and now I will be able to enjoy myself there even more. I am writing slightly under influence because after last night's live Buena Vista Social club concert I am still sobering up but could not wait to thank everybody who offered help here and the Bottlehead family. I just hope tubes are properly tested before shipped in the future as I was unable to listen to the amp for weeks because of the faulty tube. Thank you again!

Will be working on Speedball next month.

On a second thought I might take Speedball with me and work on it on my vacation!


----------



## Draygonn

Good to hear. Enjoy your Crack .Sup!


----------



## .Sup

draygonn said:


> Good to hear. Enjoy your Crack .Sup!



Thanks D!


----------



## twizzleraddict

Nice Sup. I've got a box from Bottlehead in the office staring me every time I go in. Crack & Speedball inside, unopened, whispering and taunting me to take it out and build it! 
   
  I will likely be listening to this taunting for quite some time. Best not to let the HD650s know about it (they're at home) or I will have to hear it from both ends.
   
  Am I going insane???


----------



## .Sup

twizzleraddict said:


> Am I going insane??? :confused_face(1):




Hmm hard to base a diagnosis on so little info... 

Do it when you have the time, don't rush. I usually always rush when I am making something, like toy models and it never works out like I want. When I was building the crack I didn't rush and its working flawlessly. You need to be enjoying building it, I told myself If I screw it up then I screw it up, its not going to be the end of world but if I was nervous when building it then I would certainly mess something up. Although I do admit I got seriously scared when, at the end, I had to start measuring voltages.


----------



## lextek

How's everyones Crack?  I've been using headphones sparingly during the Summer months.  On the weekends I do fire up the Crack w/HD600s before everybody  else in the house is up.  I really enjoy my morning Jazz and coffee sessions on Crack................


----------



## roadcykler

My crack is just fine. I use it a few times a week but I don't think that's a problem. I could quit any time I want.


----------



## liamstrain

I have to use my crack for hours every work day, or I cannot function well. I definitely have a problem.


----------



## GeorgeNapalm

My Crack still hasn't arrived even though I ordered it on June 21


----------



## Doc B.

You are right at the head of the line. We were waiting several weeks for a large shipment of power transformers, which showed up yesterday. We plan to work through the weekend and be shipping Crack orders again early next week.


----------



## GeorgeNapalm

Thanks for the update Doc!


----------



## Draygonn

I'm very tempted to pickup an HD650 to fuel my crack addiction.


----------



## Ultrainferno

I really should use more Crack, but with the Woo coming in too that's going to be hard


----------



## milosz

The Crack w/ Speedball is a favorite of mine for my HD800's
  

My Crack is white.  
I have replaced the output electrolytic caps with film caps.
I did eventually find my Bottlehead badge and put it on the front
  
 8/30/14 update-  I sold my HD800's but now love using a pair of 600-ohm Beyer DT880's on this amp.  I have pretty much gone over to electrostatic headphones, and have gotten rid of most of my dynamic 'phones and amps-  but the Crack is a keeper!
  
  
  

  
 I also have an Eros phono stage.  Stock except fancy film caps for output coupling.


----------



## Draygonn

milosz said:


> The Crack w/ Speedball is a favorite of mine for my HD800's



It is an amazing combination. Doc and Queen have given us a very capable amp. I love your white faceplates with the dark stain.


----------



## moviedave

I want to get one of these really bad.  See if the Crack, HD650 combo is as good as everyone says it is.


----------



## Doc B.

We just got a large batch of power transformers and chassis plates in. We're on vacation for a week or so and we will be getting back to packing and shipping when we return, so the wait could be a little shorter than usual.


----------



## ben_r_

Does Bottlehead sell the Crack transformer and/or chassis plate separately? If so for how much?


----------



## Doc B.

We do sell the chassis plate for $45, but we don't sell that particular power transformer (PT-3) due to our agreement with the designer. We have a very similar transformer, the PT-7, that differs only in having a single high voltage secondary winding rather than two windings that are each rated for half as much current in the PT-3. I'm out of town until next week and don't have access to the prices, but I think it is around $80 or $90.


----------



## .Sup

Anyone know for a good Schuko angled cable?


----------



## SpaceUnicorn9

Hi all,
   
  I'm new here and I was curious if anyone had any humble advice for me regarding amps.   I have a asgard/650/bifrost now and I think its great. However, been thinking about to the crack w/speedball.  Regarding music genre, I listen to acoustic/shoegaze/punk rock.  Would the crack be "worse"?  I was thinking about the figaro 339 but I heard its slower, and the crack is faster. I assume this affects the genre of music.
   
  What's the approximate build price for good tools for the kit? I have no tools and no experience, otherwise its about 620$ prebuilt vs my 250$ asgard.
   
  thanks in advance for any advice!


----------



## captouch

spaceunicorn9 said:


> Hi all,
> 
> I'm new here and I was curious if anyone had any humble advice for me regarding amps.   I have a asgard/650/bifrost now and I think its great. However, been thinking about to the crack w/speedball.  Regarding music genre, I listen to acoustic/shoegaze/punk rock.  Would the crack be "worse"?  I was thinking about the figaro 339 but I heard its slower, and the crack is faster. I assume this affects the genre of music.
> 
> ...




I'd say the tools would be in the range of $100 if you had absolutely nothing and depending on what quality you wanted. I used a Hakko 25W (I know higher watt is recommended, but I had it already) that was $25-30, a $5 soldering iron stand, a helping hands tool (so it can hold a PCB for example while your hands hold the iron and solder) for <$10, and you'll want a multimeter ($30?), wire-stripper (<$10), needle nose pliers (<$10), solder. Nothing I have is great, but they're all good enough quality to be reliable and re-use.

I see Cracks on the FS forum from time to time as low as $300, so you can always keep an eye open for a used one as well if you want to save some $, but they don't seem to come up really frequently.


----------



## Doc B.

Couple of things I should mention -
   
  one is that we have stopped offering kit assembly for a flat rate. One important aspect of the sound to me is due to the fact is that it is hand wired, point to point. While the process does not require extreme skill, it does require a fair amount of time investment to hand wire a complete amp with care. That combined with the fact that the number of amps that we sell assembled is tiny compared to the number of amp kits we sell (which is awesome, as DIY rules) has made us realize that we can't really cover our labor at the old prices. So we would have to charge our full shop rate to build an amp. That might cost about as much as the amp itself. 
   
  the other thing is that we see a fair number of amps coming in that were purchased used and need repair. Bear in mind that what may seem to be a great deal may end up costing more in terms of repair. Some folks meticulously build beautifully crafted amps. Some folks hurry and disregard some suggested tools or techniques and may end up with something with problems. Naturally we have no control over this. My suggestion is at the very least ask for a photo of the underside if you are considering a used amp. It it looks great and the seller promises it works you will probably be OK. If it looks scary and the seller is vague about operation you may end up with more than you bargained for. And by the way we only work on stock builds. A different set of caps or a couple different resistors is fine, but if an amp has been heavily modified with custom attenuators, different tubes, etc, we can't work on it.
   
  Probably the last thing I should mention is that we have been cranking to get caught up on orders after a family member passed away earlier this month. We have some needed components arriving in the next couple of days and quite a few Crack kits will be shipping next week.


----------



## Armaegis

Sorry to hear about your family Doc. Hope all is well.


----------



## Doc B.

Thanks, for the kind words. It was my 94 year old mom who passed, so it was not like we didn't expect it someday. But even so there is some time needed to recover. On the brighter side we got a few of the oldest Crack kit orders out yesterday and I got word this morning that the tube sockets and some tubes we need will be here tomorrow, so I am envisioning more kits leaving for their new homes Monday.


----------



## SpaceUnicorn9

Thank you very much Captouch and Doc for your informative replies. I appreciate it, however I called Elieen at Bottlehead a couple days ago and I was lucky enough to grab a prebuilt crack/speedball that another customer cancelled. She was very nice and helpful.  I cannot wait to fire it up. 
   
  Doc, sorry to hear about your mother, condolences,  sounds like she lived a very full life.


----------



## captouch

spaceunicorn9 said:


> Thank you very much Captouch and Doc for your informative replies. I appreciate it, however I called Elieen at Bottlehead a couple days ago and I was lucky enough to grab a prebuilt crack/speedball that another customer cancelled. She was very nice and helpful.  I cannot wait to fire it up.
> 
> Doc, sorry to hear about your mother, condolences,  sounds like she lived a very full life.




Perfect, sounds great. Let us know how you like it!


----------



## SpaceUnicorn9

I just swapped out my Asgard for the Crack/Speedball and it really brings these headphones alive, its unbelievable and somewhat surreal.  The depth, clarity and soundstage is outstanding.  These should come bundled with this amp!  Great combo.   Wish I had time to build this amp, maybe down the road but for now, I can't thank that person enough for cancelling this beauty.  Kudos to Doc and his crew!!  I can't wait to experiment with tube rolling. I hear its fun. 
   
  Any good recommendations for rca (digital or analog?)interconnects? I'm using a set of high end component video cables at the moment.


----------



## OJNeg

http://www.monoprice.com/products/department.asp?c_id=102
  or
  http://www.bluejeanscable.com/


----------



## SpaceUnicorn9

great thanks


----------



## ben_r_

Def monoprice!


----------



## Kajun

I am wondering if I can use my Audioengine D1 as the dac through the RCA's out the back and into the Crack?? would that work I don know if the RCA's out are amplified or not or if it matters??


----------



## liamstrain

I do not believe that the D1's volume control affects the RCAs - so you could use it as a line out to the Crack without dealing with double volume pots..


----------



## Kajun

Quote: 





liamstrain said:


> I do not believe that the D1's volume control affects the RCAs - so you could use it as a line out to the Crack without dealing with double volume pots..


 
  Any way to test it real quick?I dont have speakers with rca plugs


----------



## Kajun

lol, when in doubt read the manual.. Yeah, the rear rca's are meant for powered speakers or a receiver..so it should work fine...


----------



## .Sup

Here is mine



Photostream link: http://www.flickr.com/photos/sups_photos/sets/72157631541967824/


----------



## longbowbbs

.SUP, nice project! How long did it take you to assemble everything?


----------



## .Sup

longbowbbs said:


> .SUP, nice project! How long did it take you to assemble everything?



Thanks long! In hours about 8. As impatient of a person I am I expected to be done sooner but decided before starting to take is slowly and reliably. That's why I had no problems, at least not from my work. Dead silent all the way. So I worked for 3 days. The stock front tube left channel didn't work properly so I had to wait 2 weeks for a new tube from ebay. Then another day to install Speedball and another day to paint it.


----------



## longbowbbs

Quote: 





.sup said:


> Thanks long! In hours about 8. As impatient of a person I am I expected to be done sooner but decided before starting to take is slowly and reliably. That's why I had no problems, at least not from my work. Dead silent all the way. So I worked for 3 days. The stock front tube left channel didn't work properly so I had to wait 2 weeks for a new tube from ebay. Then another day to install Speedball and another day to paint it.


 
  Looks like your patience paid off. How is the sound?


----------



## .Sup

longbowbbs said:


> Looks like your patience paid off. How is the sound?



Well lets just say the HD800 have been dusted off.  I now have two amazing setups: HE-500 and SLP Auditor and HD800 and Crack. Both headphones plugged into these amps 24/7


----------



## longbowbbs




----------



## .Sup

longbowbbs said:


>



My father loves their shirts, I have bought him one in most available colours hehe

I don't feel a need to a get another amp now, just desire to have more. Will you build one 2 long?


----------



## liamstrain

Looks like a nice build .Sup. Did you do much listening before you put in the Speedball? or did you pretty much just install it right away?


----------



## Ultrainferno

Never enjoyed it as much as with the HD700 now!


----------



## .Sup

liamstrain said:


> Looks like a nice build .Sup. Did you do much listening before you put in the Speedball? or did you pretty much just install it right away?



Not as much as I wanted to since the stock tube wasn't working. About two weeks of moderate listening. To me bass seems tighter after Speedball, haven't noticed anything else.


----------



## LordWormwood

Just found this thread and the amp itself - so forgive if this has been asked before.

What would be the factory equiv. of the crack?

I am new to the world of quality audio and therefore treading the path carefully & slowly. Would I be 'wasting' money on the Crack for Q701?



I have never soldered a board before and know nothing of resistances etc - is this our of my legue?


Wormwood


----------



## Armaegis

A review from InnerFidelity... http://www.innerfidelity.com/content/marvelously-addictive-bottlehead-crack
   
  Quote: 





lordwormwood said:


> Just found this thread and the amp itself - so forgive if this has been asked before.
> What would be the factory equiv. of the crack?
> I am new to the world of quality audio and therefore treading the path carefully & slowly. Would I be 'wasting' money on the Crack for Q701?
> I have never soldered a board before and know nothing of resistances etc - is this our of my legue?
> Wormwood


 
   
  From my memory, I did not think the K701 was a good match with the Crack. That was a long time ago though. 
   
  The Crack isn't too hard to solder, and it comes with a fantastic manual. It helps if you've had some experience soldering other things before though. Check some youtube videos, try soldering on some scrap materials and wire to get a feel for it.


----------



## liamstrain

Because this is an OTL design (output transformer-less) it is not usually considered a good match with low impedance headphones like the Q701 - the impedance mismatch will lead to bloated less controlled bass. 
   
  I would look for either Transformer coupled tube amps (usually more expensive), hybrid tube amps (less expensive, usually), or solid state designs - which pair better with low impedance headphones. 
   
  (Low impedance headphones need more current, less voltage, while high impedance headphones require higher voltage, but less current).


----------



## LordWormwood

Thank you both. 
   
  Any directions for either of these?
   
   
   
  Wormwood


----------



## liamstrain

From a DIY standpoint, none of your other Tube options are going to be as beginner friendly as the Crack. And frankly, it's a good enough amplifier, it's probably worth it to go ahead and make some day, and acquire a different set of cans to really take advantage of it - you can of course, use your Q701 with the Crack, it is just not a very good pairing to get the best out of both... 
   
  So with that in mind, I would probably look at a basic solid state option to power the Q701. The "Lovely Cube" is a clone of the Lehmann Black Linear Cube (so is the M-Stage) and can be bought fully built, partially built, or as a full kit to build yourself. Likewise the 02 can be found fully built, or in various stages of partial builds for less money. Both of them will serve admirably paired with the Q701.
   
  If you really want to go with Tubes and the Q701 (and DIY) - I would look at a hybrid like the Millet MiniMAX kit from Beezar - it's going to be a more complicated build though. 
   
  Commercial tube amps to pair with it, would be the Schiit amps, the Little Dot 1+, Hifiman EF 5...


----------



## LordWormwood

Liam,
   
  Thanks for that. It's the second time that the O2 has been recommended for the Q701... so I just might head down that path. Of course now that I have stumbled through this doorway it's going to nag and eat away at me until I get one - so I will look into starting a Crack habit also.
   
   
  Cheers all for the sagely advice.
   
   
  Wormwood


----------



## Draygonn

armaegis said:


> from InnerFidelity...



[VIDEO]http://www.youtube.com/watch?feature=player_embedded&v=s5rWCEux_BI[/VIDEO]


----------



## LordWormwood

Thanks Draygonn for posting that link correctly... I was on an ipad so I didn't know if it was the forum/ipadness or just a slightly wrong cut&paste.
   
  Wormwood


----------



## .Sup

lordwormwood said:


> I have never soldered a board before and know nothing of resistances etc - is this our of my legue?
> Wormwood



I haven't either but made it work.


----------



## Armaegis

Quote:  
   
  Whoops, can't believed I blundered like that. Edited the most... move along... nothing to see here...


----------



## longbowbbs

Quote: 





armaegis said:


> Whoops, can't believed I blundered like that. Edited the most... move along... nothing to see here...


 
  Hey, reruns are supposed to end after Labor day!!


----------



## LordWormwood

That is a great vid - the tips and tricks really help make me feel that this could be done by me without too much of a hic-up. 
   
   
  Thanks for the posting of it.
   
   
  Wormwood


----------



## Ultrainferno

Someone made a Facebook Fan Club for the Crack:
   
  https://www.facebook.com/BottleheadCrackFanpage


----------



## elwappo99

There's a group buy for this amplifier over at massdrop
   
  I'm extremely tempted to jump in and get back into tubes!


----------



## .Sup

I extremely impressed by the Crack. Ref5 into the Crack with HD800 is an amazing setup. I think I am done with upgrades.


----------



## ben_r_

Quote: 





elwappo99 said:


> There's a group buy for this amplifier over at massdrop
> 
> I'm extremely tempted to jump in and get back into tubes!


 

 If they get 25+ committed Ill probably jump on this as I really dont feel the Crack is worth more than $200.


----------



## elwappo99

Quote: 





ben_r_ said:


> If they get 25+ committed Ill probably jump on this as I really dont feel the Crack is worth more than $200.


 
   
  Unfortunately the deal has been running a few days and only has 1 person committed. I don't think a lot of people on head-fi have jumped on it though.


----------



## LordWormwood

The sad thing is that I would have jumped on this but I am just about to grab the S.E.X kit from BottleHead.
   
  Thanks for the heads though
   
   
  Wormwood


----------



## Beefy

Quote: 





ben_r_ said:


> If they get 25+ committed Ill probably jump on this as I really dont feel the Crack is worth more than $200.


 
   
  What are you basing that on, exactly? The Crack is a phenomenal amp for the price.


----------



## ben_r_

Quote: 





beefy said:


> What are you basing that on, exactly? The Crack is a phenomenal amp for the price.


 

 The fact that I have a degree in electrical engineering, have poured over the schematic for it, and the cost of the parts involved. Either way its my opinion, nothing more.


----------



## liamstrain

Quote: 





ben_r_ said:


> The fact that I have a degree in electrical engineering, have poured over the schematic for it, and the cost of the parts involved. Either way its my opinion, nothing more.


 
   
  This is true of 99% of all consumer electronics equipment though. It would be difficult to find an OTL tube amplifier as good as it, built by any manufacturer for anything close to this price. And for 8 hours worth of work - with a well documented, all inclusive kit, this still represents a lot of value to those of us who are not up to the task of (or have enough time to) drafting our own schematics, sourcing our own parts, and truly scratch building. 
   
  *shrug*
   
  Everyone's definition of value is different. For many of us, this represents a good balance between high end sound, cost, and time/effort. Your own equation will be different based on your own variables of time, expertise, and budget.


----------



## Beefy

Quote: 





ben_r_ said:


> The fact that I have a degree in electrical engineering, have poured over the schematic for it, and the cost of the parts involved. Either way its my opinion, nothing more.


 
   
  Never mind the fact that extremely similar commercial offerings go for substantially more money, and use similarly inexpensive parts......


----------



## Bojamijams

Quote: 





ben_r_ said:


> The fact that I have a degree in electrical engineering, have poured over the schematic for it, and the cost of the parts involved. Either way its my opinion, nothing more.


 
   
  That is a very limited and simple view.
   
  There is the enclosure and the cost of cutting it... the cost of the training material that ships with it.. the cost of packaging and sourcing of tubes (and matching the tubes)
   
  There's a LOT more to the final price then just the price of the electronics


----------



## MrDavis

The Crack is indeed a phenomenal amp for the price.   It was the 3rd headphone amp I built and I have not built another since.   The first two amps are in the closet collecting dust....


----------



## ben_r_

Quote: 





liamstrain said:


> This is true of 99% of all consumer electronics equipment though. It would be difficult to find an OTL tube amplifier as good as it, built by any manufacturer for anything close to this price. And for 8 hours worth of work - with a well documented, all inclusive kit, this still represents a lot of value to those of us who are not up to the task of (or have enough time to) drafting our own schematics, sourcing our own parts, and truly scratch building.
> 
> *shrug*
> 
> Everyone's definition of value is different. For many of us, this represents a good balance between high end sound, cost, and time/effort. Your own equation will be different based on your own variables of time, expertise, and budget.


 

 Very true and well put. That is why I suffixed the statement with "just my opinion".


----------



## Doc B.

That's why I don't ask our engineers to establish margins. Nor do I ask our accountants to design our gear.


----------



## BmWr75

I'd like to upgrade the volume pot on my Crack.  Any recommendations??  Where to buy also would be helpful.


----------



## Pr0fessiona1

I hear blue alps is a good one. I love my crack, powers my hd650's beautifully.


----------



## skeptic

tkd 2511 pots, available at parts connexion, are quite nice and a drop in substitute for stock.  I've been very pleased with mine.


----------



## ben_r_

Quote: 





doc b. said:


> That's why I don't ask our engineers to establish margins. Nor do I ask our accountants to design our gear.


 
  Well put Doc


----------



## mosshorn

I miss my Crack so much  I'm starting to regret my venture into portable audio when I see pictures of my old baby


----------



## lextek

I start my weekend mornings with Crack, coffee and jazz.


----------



## longbowbbs

Quote: 





lextek said:


> I start my weekend mornings with Crack, coffee and jazz.


 
   
  Tubes are the way to start the day!


----------



## roadcykler

Quote: 





skeptic said:


> tkd 2511 pots, available at parts connexion, are quite nice and a drop in substitute for stock.  I've been very pleased with mine.


 
   
  I'll second that. I don't like how they do their shipping calculations but I like the part.


----------



## Warrax

Hello, I would like to ask, what DAC is good for CRACK.
   
  Second question, if I use also studio monitors, and switching between headphones and monitors (on night to headphones, to not disturb neightboars),
  what DAC should I use for this purpose. It needs to have 2 sets of DAC out, right? One I connect directly to studio monitors, and one, I connect to CRACK.
  Right now I have NFB11.32, which is DAC/preamp + headphones amplifier, and I'm looking at back plate, and there is only one set of DAC out. So, in this case, it's not possible to use connected it to monitors and CRACK at once?
   
  Now question, what do you see as better combination:
  300$ standalone DAC + CRACK
  or
  NFB10.32 with balanced output


----------



## skeptic

I've also been spending some quality time with my crack and HD800's this weekend, and I am loving a new tube complement I just picked up from the fs forum!  In addition to a host of other highly regarded 6as7's/5998's/6080's etc., neogeo333 had, and may yet have, a few rare GEC 6as7g's for sale - a tube I have always wanted to try based on skylab's highly favorable reviews.  
   
  In any event, I bought one, along with a spare 5998, and my initial impression is that I am _really_ going to enjoy the GEC tube.  The gain on my crack has always been a little bit high for my HD800's when running 5998's (which have been my favorites to date nonetheless).  It seems like the GEC tube is just as refined as a 5998, but with a lower gain that works really really well in my configuration.  (Thought I'd mention this here, sooner rather than later, in case any others on team-crack are looking for modestly priced, high quality, well cared-for 6as7's - which sadly seem to be harder and harder to find in recent years).  
   
  It should be lots of fun comparing my various 5998's with the GEC over the coming weeks.  I'm pretty well settled on a 1959 TS 12bh7 as my favorite tube in the A socket.  Also thinking it may finally be time to try a pair of obbligato's in place of the axon's I'm using as output caps.  The joy of experimenting with this outstanding little amp really is endless!


----------



## liamstrain

Quote: 





warrax said:


> Right now I have NFB11.32, which is DAC/preamp + headphones amplifier, and I'm looking at back plate, and there is only one set of DAC out. So, in this case, it's not possible to use connected it to monitors and CRACK at once?
> 
> Now question, what do you see as better combination:
> 300$ standalone DAC + CRACK
> ...


 
   
  You could make or buy a source distribution box, or even just do a split cable. 
   
  As a better combination - I prefer a separate dac + crack, than an all in one - gives more options for upgrades down the line. I really like the Yulong D100 with my crack - which does have balanced line outs (depending on your monitors, you could use XLR cables from there) as well as a set of standard stereo audio outs. It's a bit more than $300 though - unless you find used.


----------



## Warrax

Quote: 





liamstrain said:


> You could make or buy a source distribution box, or even just do a split cable.
> 
> As a better combination - I prefer a separate dac + crack, than an all in one - gives more options for upgrades down the line. I really like the Yulong D100 with my crack - which does have balanced line outs (depending on your monitors, you could use XLR cables from there) as well as a set of standard stereo audio outs. It's a bit more than $300 though - unless you find used.


 

 Can you please give example of such distribution box, or split cable (some pictures)... from what I've read, I cannot imagine it, what it is.
   
  Thank you, yes my monitors have also XLR inputs, so balanced DAC is not a problem.
  Crack on other side, don't have balanced output for headphones, just normal one?
   
  So Yulong D100 + crack, will make better sound for headphones for a bit higher price than NFB10.32?
  What about sound to monitors... will Yulong D100 alone (I assume it's only DAC, not preamp) will make better sound on monitors, than NFB10.32?
   
  As I've have NFB11.32 now, I've tried fixed and variable output to my Monitors, and I assume, that fixed is just DAC, but variable is also DAC + preamp (or only DAC + volume control, with no amping?). Because I've had feeling, that variable made slightly better sound then fixed on active monitors.


----------



## Draygonn

warrax said:


> Can you please give example of such distribution box, or split cable (some pictures)... from what I've read, I cannot imagine it, what it is.



RCA Splitter Cable


Switchbox


----------



## skeptic

Quote: 





warrax said:


> So Yulong D100 + crack, will make better sound for headphones for a bit higher price than NFB10.32?
> What about sound to monitors... will Yulong D100 alone (I assume it's only DAC, not preamp) will make better sound on monitors, than NFB10.32?


 
   
  This is going to boil down to personal preferences Warrax.  If you are using high impedance headphones, you will *probably* really enjoy the crack, paired with any decent quality dac.  As you can tell from this thread, many head-fiers really like this amp a lot.  That said, some people have different preferences and might prefer the nfb10.
   
  As one of many possible alternatives to the yulong, keces also makes some very nice budget dacs you might take a look at.  They measure well and have generally received positive reviews (see, e.g., http://www.enjoythemusic.com/magazine/equipment/0808/keces_da151.htm).  I've had my Keces 131 for several years now, and it is a very solid little unit.


----------



## irishsammy

Hi everybody.  Just finished my first Crack build and plugged in my DT880/600's. 
   
  Holy crap does this thing sound good.


----------



## liamstrain

Looks good. Enjoy! What's the pretty KT88 piece next to it?
   
   
  Does anyone have a spare (unused preferred) alder base they didn't use from their kit?


----------



## Warrax

Quote: 





irishsammy said:


> Hi everybody.  Just finished my first Crack build and plugged in my DT880/600's.
> 
> Holy crap does this thing sound good.


 
  What's that for color of wood? I've always seen CRACK as bright brown wooden color. This is looking really really awesome with this darker wood color. Do they ship such wooden pieces now, or it is made by you?


----------



## captouch

They ship wood pieces unfinished, and you can stain them (or not stain them at all) whatever color you want.  Most that I've seen are unstained or stained some shade of brown.  But you do see dark/black ones occasionally like this one.  
   
  That's the cool thing - each one that has anything done to it is really pretty unique.  You can also paint the top plate as well.  
   
  Here's mine:


----------



## roadcykler

Quote: 





captouch said:


> They ship wood pieces unfinished, and you can stain them (or not stain them at all) whatever color you want.  Most that I've seen are unstained or stained some shade of brown.  But you do see dark/black ones occasionally like this one.


 
   
  If you look on the Bottlehead site, you'll see all manner of base modifications and colours. I stained mine a dark blue and painted the top plate with the hammered copper paint. There's probably a picture of it in this thread somewhere.


----------



## Draygonn

irishsammy said:


> Hi everybody.  Just finished my first Crack build and plugged in my DT880/600's.
> 
> Holy crap does this thing sound good.  :eek:


Yes it does. Welcome to the club. I like the colors you used. 

I recently painted my transformer cover black. 

It was starting to show signs of wear.


----------



## skeptic

Quote: 





irishsammy said:


> Hi everybody.  Just finished my first Crack build and plugged in my DT880/600's.
> 
> Holy crap does this thing sound good.


 
   
  That was my initial reaction as well.  Even in stock form, the crack is surprisingly detailed, punchy and dynamic for an OTL tube amp, and it only gets better with tweaks.  You have to love those rare moments in life when the reality of a product actually surpasses high expectations.
   
  In any event, congrats and welcome aboard!


----------



## irishsammy

Thanks everybody for the comments. 
   
  I used Minwax stain in the Ebony color for the base.  The alder wood they send you for the base is really nice so I hated to make it so dark but I just made a headboard for my wife where I used the same stain and it came out looking really, really good.  My base still doesn't have any polyurethane on it (I was too excited to finish the amp to do that part) and when you put that on, it lightens things up noticeably but it still has that nice dark wood look.  My speakers are finished in a beautiful dark African wenge veneer and I'm hoping to end up with something like that...
   
  ...when I can stop listening to this stupid thing!  Seriously...[insert cheesy "addicted to Crack" line here].


----------



## irishsammy

Quote: 





skeptic said:


> That was my initial reaction as well.  Even in stock form, the crack is surprisingly detailed, punchy and dynamic for an OTL tube amp, and it only gets better with tweaks.  You have to love those rare moments in life when the reality of a product actually surpasses high expectations.
> 
> In any event, congrats and welcome aboard!


 
   
  I was shocked that I put the thing together correctly, let alone that it makes such amazing music.  It's enough to make you into one of those motivational If-I-Can-Do-It-Anybody-Can people.


----------



## Armaegis

I really like the look of the copper hammertone paint on mine. I tried to take some pictures, but I just can't capture the paint texture.


----------



## RonO

I went with the ebony minwax as well, with poly - hammertone black on the top.  I never put the badge on, I'm still noodling on doing something else to the finish.


----------



## networkn

Hi Guys, 
   
  I have read through some pages here and am leaning toward trying this AMP. I am not 100% Confident I can build it, but hopefully if I get stuck I can get some help. 
   
  I have some questions if someone wouldn't mind;
   
  1) What are the dimensions of this and the weight please?
  2) What is the power supply? I am from NZ and we have 240v, do I need to specify at time of ordering?
  3) I am thinking of pairing this amp with the O2 Odac, will this be OK? What connection will run between the ODAC and BHCA?
  4) I am fairly close to my budget, and I have read the speed-ball upgrade is worthwhile, I'll be pairing this with my HD650's
  5) I already have an Asus Xonar STX, which is apparently a capable Dac/AMP, is it reasonable to assume the BHCA will be a reasonably noticeable upgrade? I have just been conversing with someone who has the STX and the Dot III and they said listening they thought the Dot III was better, but in a blind test they couldn't pick them apart from the STX. I am concerned about spending $400 and not getting a noticeable improvement.
  6) Which parts are most likely to get damaged in assembly, and should I order spares? I guess I am mostly concerned about parts getting too hot during soldering, and secondly damage caused by mis-assembly and having to wait weeks for replacements.
  7) I was thinking about doing the wood in a black finish and polishing the metal to a high shine, anyone have any experience with this and recommend a method of it?
  8) Anyone know of any other assemblies other than the Wooden Box?
   
  Thanks for your time.


----------



## liamstrain

Quote: 





networkn said:


> Hi Guys,
> 
> I have read through some pages here and am leaning toward trying this AMP. I am not 100% Confident I can build it, but hopefully if I get stuck I can get some help.
> 
> ...


----------



## Cryok95

Hey guys, I just bought my Crack amp today with speedball, bottlehead's 15% off for Cyber Monday was too tempting. Not to mention the fact that I got an extra 10% off buying with a friend.

Now, any recommendations for boutique film capacitators to build inside? I'm thinking Mundorf Supreme and perhaps some Obligato Gold


----------



## networkn

Yup I jumped whilst everything was 15% off and got both the crack and speedball. I hope it's amazing!


----------



## DairyProduce

I was going to jump on cyber monday sale as well...but I wasn't sure about building one myself  (don't want to solder etc... I'm just lazy 
	

	
	
		
		

		
		
	


	




)
   
  I've been thinking about trying some tube amps with my HD 800's that should be coming soon. I've been seeing that the Crack is something of a giant killer? Is this the tube amp that I should get for under $1k if I want to try the tube sound? 
   
  Also, what happened to the Smack? o_o


----------



## LordWormwood

From what I understood the Smack might come back but it was run to the ground (stock) mainly due to having the S.E.X which covered that range of headphone impedance. The SEX also drives speakers which made it better value at the same price point. 

I guess it (the Smack) became too niche for the store. I enquired into modding the Crack to run High impedance cans - the cost would shift the unit to the SEX level (which is what the Smack was, from whati understand). 

I got the Quickie per-amp on the Cyber Monday sale.



Wormwood


----------



## BmWr75

Quote: 





lordwormwood said:


> I enquired into modding the Crack to run High impedance cans - the cost would shift the unit to the SEX level (which is what the Smack was, from whati understand).


 
   
  The Crack is designed for high impedance cans, >120 ohm if I remember correctly.  It works poorly with low impedance cans.


----------



## LordWormwood

I totally blame posting before 7am and only on half a cup of tea.







Wormwood


----------



## Takaki

When will my cyber monday order ever gonna shippppppppppppppppppppp.

Cant wait to start on it already.


----------



## Cryok95

I forsee a month or two


----------



## BmWr75

Bottlehead customers learn patience.   You are ordering from a small business, not Amazon.com.


----------



## Ultrainferno

Quote: 





bmwr75 said:


> Bottlehead customers learn patience.   You are ordering from a small business, not Amazon.com.


 
   
  I waited for 2.5 months. It'll be worth it guys, be patient


----------



## tiestolife

Hey guys im new here and looking for a first audiophile set-up. I'm just wondering what degree of electronic knowledge one needs for this DIY kit? I have the basics at soldering but thats pretty much it...


----------



## liamstrain

None is required. The circuit is set, and the instructions are very complete, even walking you through voltage checks. A basic knowledge of soldering is all that is required.


----------



## Mak333

Quote: 





liamstrain said:


> None is required. The circuit is set, and the instructions are very complete, even walking you through voltage checks. A basic knowledge of soldering is all that is required.


 

 BASIC knowledge of soldering, emphasized.  As in: I've never soldered anything before, went to Home Depot, bought a soldering iron and solder, watched a 5 minute YouTube video on how to solder, then built the Crack amp in two evenings by myself.
  
  No need for practice really... Just start off with the instruction manual that Doc & team has put together.  Not too much can be damaged from overheating in the first few pages I believe, so there's your practice.  Again, I reiterate, I've never soldered before;  the Bottlehead Crack amp was my first time soldering ever, and I've since completed the Crack, installed a different potentiometer, speedball upgrade (well worth it), and new capacitors.


----------



## networkn

Quote: 





mak333 said:


> BASIC knowledge of soldering, emphasized.  As in: I've never soldered anything before, went to Home Depot, bought a soldering iron and solder, watched a 5 minute YouTube video on how to solder, then built the Crack amp in two evenings by myself.
> 
> No need for practice really... Just start off with the instruction manual that Doc & team has put together.  Not too much can be damaged from overheating in the first few pages I believe, so there's your practice.  Again, I reiterate, I've never soldered before;  the Bottlehead Crack amp was my first time soldering ever, and I've since completed the Crack, installed a different potentiometer, speedball upgrade (well worth it), and new capacitors.


 
   
  Thanks for the information, I'm interested to know why you would replace the potentiometer and new capacitors? How long did the speedball upgrade take you?


----------



## Doc B.

[size=small]Just a quick update - we have been hammering on our parts suppliers to get us the parts we need for the gigantic number of orders we got on cyber Monday. Parts are coming in, our kids are on winter break from college and stepping up to help pack, and Queenie says we will begin shipping those orders this week. It may take a week or two to get them all out as some more parts are due to arrive over the next several days, but be assured we have the packing pedal to the metal at Bottleheadquarters.[/size]


----------



## longbowbbs

Glad to see business is good, Doc! Congrats.....I hope it keeps going for you.


----------



## Draygonn

Looks like plenty of Crack addicts will be joining the family over the holidays. I spent most of last weekend listening to 650s on Crack. A truly magical experience!


----------



## Takaki

Thanks doc for the update!!

Can't wait to start on it, I think it would really be great if we could have a condensed FAQ thread about the crack amps.


----------



## Doc B.

Quote: 





takaki said:


> Thanks doc for the update!!
> Can't wait to start on it, I think it would really be great if we could have a condensed FAQ thread about the crack amps.


 
  Don't know if it is really any easier to plow through than this 90 page thread, but you might peruse the Crack category on the Bottlehead Forum. 5400 posts, 435 topics - at least the different Crack related topics have subject headers. We also have a fair coverage of FAQs on the Crack product page and a separate page that discusses good headphone matches for Crack.


----------



## Mak333

Quote: 





networkn said:


> Thanks for the information, I'm interested to know why you would replace the potentiometer and new capacitors? How long did the speedball upgrade take you?


 

 A friend/co-worker suggested the potentiometer upgrade.  I don't know if I've heard an audible difference, but it looks cool and it's a little smoother back and forth... (That's me admittedly not understanding the full science of a potentiometer and quality).  The capacitors did make a difference, in addition to the speedball upgrade.
   
  If you're looking for more info as to how the upgrades work and differences, as Doc said, check out the Bottlehead forums under the "Crack" category and there are pages and pages and pages of people's crack builds and input/feedback.


----------



## Draygonn

Does anyone have in-line attenuator recommendations? I'm running from a SBT at 100% and want more volume play without dealing with the channel imbalance at the low end

Anyone have experience with these? What's a good db to use?
http://www.amazon.com/Harrison-Labs-Line-Level-Attenuator/dp/B0006N41B0/ref=?ie=UTF8&m=A385A0XNQBW8HY


----------



## Cryok95

Just use an alps potentiometer.


----------



## Cryok95

Double post


----------



## Draygonn

cryok95 said:


> Just use an alps potentiometer.


I'm not in a soldering mood so I ordered those Harrison Labs in-lines with an amazon gift card. If they do what I want I will give this rig my endgame stamp of approval. I just sold my HD800/WA2 rig. I love the 650s on Crack presentation and rarely want to listen to anything else.


----------



## longbowbbs

I love it DG! I can't get right with the 800's. Love to hear the Crack one day to compare with my CSP2+ on my 650's.


----------



## irishsammy

Quote: 





draygonn said:


> I'm not in a soldering mood so I ordered those Harrison Labs in-lines with an amazon gift card. If they do what I want I will give this rig my endgame stamp of approval. I just sold my HD800/WA2 rig. I love the 650s on Crack presentation and rarely want to listen to anything else.


 
   
  Whew.  
	

	
	
		
		

		
			





  I have the same view of my HD600's/Crack vs. my LCD-2/WA6-SE.  Glad I'm not the only one killing giants here.


----------



## MilesDavis2

irishsammy said:


> Whew.     I have the same view of my HD600's/Crack vs. my LCD-2/WA6-SE.  Glad I'm not the only one killing giants here.




Love the crack vs. WA6 in driving my 600 ohm DT880


----------



## Cryok95

My crack just shipped together with the other Cyber Monday batch!! Hopefully I will be getting it soon  can't wait!!


----------



## Doc B.

Yes, we did a marathon session yesterday when the chassis panels we had been waiting for arrived, and we got all Cyber Monday Crack orders (equivalent to about a full month's worth of orders) shipped. Actually all Crack kits ordered up through December 5th shipped.


----------



## networkn

If you bought the crack and speedball parts together, is there an updated manual that shows you how to assemble it in one go rather than unsoldering and replacing parts?


----------



## themusic2

I too would like to know that. I have standard Crack circuits in a very small footprint chassis which makes speedball upgrade impossible. This is it next to a Lyr ...
  https://picasaweb.google.com/lh/photo/ScvbclqB5rysDnp9SvRWLdMTjNZETYmyPJy0liipFm0?feat=directlink
  So I wouldn't mind having another diy session and get Crack + Speedball (in another custom chassis of course  to hear the difference.


----------



## uzi

I've built one with the speedball upgrade.  Honestly, you want to start with the normal crack built and then add the upgrade... you only have to remove a few things from the crack before applying the speedball.  Plus, as an added bonus, you can listen to your crack while you do the three little boards for the speedball upgrade.


----------



## Armaegis

Quote: 





themusic2 said:


> I too would like to know that. I have standard Crack circuits in a very small footprint chassis which makes speedball upgrade impossible. This is it next to a Lyr ...
> https://picasaweb.google.com/lh/photo/ScvbclqB5rysDnp9SvRWLdMTjNZETYmyPJy0liipFm0?feat=directlink
> So I wouldn't mind having another diy session and get Crack + Speedball (in another custom chassis of course  to hear the difference.


 
   
  Oh that's nice! I've seen a build like that before some time ago... maybe it was yours?


----------



## Armaegis

Quote: 





networkn said:


> If you bought the crack and speedball parts together, is there an updated manual that shows you how to assemble it in one go rather than unsoldering and replacing parts?


 
   
  Well basically you just omit four resistors during construction of the Crack and install the speedball components when you get to it.


----------



## networkn

I would really like to find a nice Black Finish on the wood. Anyone able to recommend something?


----------



## networkn

Quote: 





themusic2 said:


> I too would like to know that. I have standard Crack circuits in a very small footprint chassis which makes speedball upgrade impossible. This is it next to a Lyr ...
> https://picasaweb.google.com/lh/photo/ScvbclqB5rysDnp9SvRWLdMTjNZETYmyPJy0liipFm0?feat=directlink
> So I wouldn't mind having another diy session and get Crack + Speedball (in another custom chassis of course  to hear the difference.


 
   
  Wow that looks awesome man! I'd love to see some more pictures and also an idea on that  finish for the wood.


----------



## lextek

themusic2 said:


> I too would like to know that. I have standard Crack circuits in a very small footprint chassis which makes speedball upgrade impossible. This is it next to a Lyr ...
> https://picasaweb.google.com/lh/photo/ScvbclqB5rysDnp9SvRWLdMTjNZETYmyPJy0liipFm0?feat=directlink
> So I wouldn't mind having another diy session and get Crack + Speedball (in another custom chassis of course  to hear the difference.




Beautiful job on the Crack. I had originally planned on doing something very, similar with the layout on mine. I got anxious and built it stock. Very, nice job.


----------



## ben_r_

themusic2 said:


> I too would like to know that. I have standard Crack circuits in a very small footprint chassis which makes speedball upgrade impossible. This is it next to a Lyr ...
> https://picasaweb.google.com/lh/photo/ScvbclqB5rysDnp9SvRWLdMTjNZETYmyPJy0liipFm0?feat=directlink
> So I wouldn't mind having another diy session and get Crack + Speedball (in another custom chassis of course  to hear the difference.



Man that does look clean! Post some more pics on that and give us some build tips!


----------



## irishsammy

Quote: 





networkn said:


> I would really like to find a nice Black Finish on the wood. Anyone able to recommend something?


 

 I used Ebony Minwax stain with 2 coats of Minwax polyurethane and mine looks great.  It's not black black (has an ever-so-slight brownish hue to it) but if you put 2 coats of the Ebony stain on it, I think you could end up with the pitch black look.


----------



## themusic2

Thanks for the compliments. The finish is simply a Jarrah timber stain on pine wood, then multiple coats of polyurethane spray rubbed down with 800 grit between about 6 coats. I've been thinking of re-making the woodwork on it as I have gotten hold of some nice western red cedar on which I'd try bees wax. But for now the Crack looks good and performs well. Just I'm keen to do the Speedball upgrade, or build another Crack with that upgrade to try to pick the sonic differences... will have to contact Bottlehead


----------



## Jimmy24

How much difference in sound will I hear from Crack + Speedball with my HD 650's vs my O2+ODAC combo?


----------



## BmWr75

Quote: 





jimbo24 said:


> How much difference in sound will I hear from Crack + Speedball with my HD 650's vs my O2+ODAC combo?


 
   
  Apples and oranges comparison.  You are asking folks to comment on differences between a tube amp (no DAC) and a solid state amp and DAC.  I have the Crack + Speedball and can tell you it sounds excellent with Beyer T70 and other 250 ohm or higher impedance cans.  But, I am feeding it lossless files via an Emotiva XDAC-1.  Have never heard either the O2 amp or ODAC.


----------



## Mak333

Quote: 





bmwr75 said:


> Apples and oranges comparison.  You are asking folks to comment on differences between a tube amp (no DAC) and a solid state amp and DAC.  I have the Crack + Speedball and can tell you it sounds excellent with Beyer T70 and other 250 ohm or higher impedance cans.  But, I am feeding it lossless files via an Emotiva XDAC-1.  Have never heard either the O2 amp or ODAC.


 

 Also keep in mind that even [Crack] vs [Crack + Speedball] sounds different, for the better.  Speedball is definitely worth the extra cash.
   
  Someone also asked earlier if they could just install Speedball in conjunction with building the Crack.  You can, but it is recommended you build the Crack FULLY first and run resistance and voltage measurements to ensure everything is installed correctly.  THEN uninstall those components to be replaced with Speedball.  Some have run into issues integrating the Speedball installation into the Crack and it could take considerable more time to troubleshoot than just the Crack itself.


----------



## networkn

Quote: 





mak333 said:


> Also keep in mind that even [Crack] vs [Crack + Speedball] sounds different, for the better.  Speedball is definitely worth the extra cash.
> 
> Someone also asked earlier if they could just install Speedball in conjunction with building the Crack.  You can, but it is recommended you build the Crack FULLY first and run resistance and voltage measurements to ensure everything is installed correctly.  THEN uninstall those components to be replaced with Speedball.  Some have run into issues integrating the Speedball installation into the Crack and it could take considerable more time to troubleshoot than just the Crack itself.


 
   
  Thanks, that is very useful. 
   
  I will complete the crack amp first (Started last night and assembly less to the beginning of the soldering section took about 1.5 hours I think. Most of that time was spent trying to determine which screws were which etc, I think it could be clearer honestly, as for those of us who a) don't work with this stuff a lot and b) work in metric, these descriptions can be troublesome.


----------



## networkn

Quote: 





irishsammy said:


> I used Ebony Minwax stain with 2 coats of Minwax polyurethane and mine looks great.  It's not black black (has an ever-so-slight brownish hue to it) but if you put 2 coats of the Ebony stain on it, I think you could end up with the pitch black look.


 
   
  Hmm trying to find the equivalent product in NZ is proving to be difficult as we don't have a lot of the brands people talk about here. Is there a specification based description I could use to try and track down the equivalent?


----------



## Armaegis

Just go to the hardware store and ask someone in the paints department about wood stains and they should be able to fill you in on what you need. Bring a piece of the enclosure with you.


----------



## skeptic

So I had a chance to do a little monkeying around with my crack over the holidays, including the installation of a pair of 100 uF / 400 V obbligato's in place of the 91 uF axons I was previously running as output caps. The folks in the bh forums weren't kidding about the easily audible improvement you can get from changing up these caps! Treble instruments are now totally grain free, and the bass response is bigger and better than it was with the axon's - although I imagine the latter has more to do with the change in capacitance than anything else (based on Doc et al.'s comments about expected bass roll off from using lower value caps).

In any event, if any of you are looking for a <$100 upgrade with an obvious impact on sound quality, this is definitely worth considering and only takes about 10 minutes if you already have zip tie pads in place. Happy listening and new year to you all!


----------



## lextek

Quote: 





skeptic said:


> So I had a chance to do a little monkeying around with my crack over the holidays, including the installation of a pair of 100 uF / 400 V obbligato's in place of the 91 uF axons I was previously running as output caps. The folks in the bh forums weren't kidding about the easily audible improvement you can get from changing up these caps! Treble instruments are now totally grain free, and the bass response is bigger and better than it was with the axon's - although I imagine the latter has more to do with the change in capacitance than anything else (based on Doc et al.'s comments about expected bass roll off from using lower value caps).
> In any event, if any of you are looking for a <$100 upgrade with an obvious impact on sound quality, this is definitely worth considering and only takes about 10 minutes if you already have zip tie pads in place. Happy listening and new year to you all!


 
  Could you post some pictures?  I've been thinking of "upgrading" my Crack/Speedball, but afraid to mess with it.  Sounds so good now.


----------



## skeptic

Quote: 





lextek said:


> Could you post some pictures?  I've been thinking of "upgrading" my Crack/Speedball, but afraid to mess with it.  Sounds so good now.


 
   
  Sure lextek.  Beefy held my hand through doing this, and hopefully these pics will give you what you need.  I haven't photographed the internals with the new obbligato's installed, but they are similar in size to the axon's depicted below (albeit a little longer).
   
  I would recommend going about it in the following order:
   
  First - install fly leads for the output caps before doing your speedball.  You can see that I am still using the stock caps at this point, but they are now on leads.  This is really the most important piece of the equation because it would be a real hassle to do after installing the speedball boards.
   
   

   
  Second - based on the size of the caps you ultimately want to use, measure the placement of your zip tie mounts, then drill your top plate to install the zip tie mounts that will hold your film caps in place.  Here are photos of the top and bottom showing the mounts and visible screws on the top, prior to installing the film caps:
   
   

   
   

   
  Third - solder in and tie down your film caps:
   
   

   
  Fourth - sit back with drink in hand and enjoy the music.  Hope this helps!


----------



## baxter97

How much for a pre-assembled unit? Does Bottlehead even offer such a service any longer?


----------



## swmtnbiker

baxter97 said:


> How much for a pre-assembled unit? Does Bottlehead even offer such a service any longer?




They do. $780 plus shipping for a pre-built Crack + Speedball.


----------



## T.F.O.A

What difference do you get when you upgrade the caps? Does it change the sound character? and is it really noticeable?


----------



## networkn

I am just starting the soldering section and I found : 
   
    AC Mains and power switch wiring
  The standard procedure for AC mains wiring in the
  US is to connect the neutral wire to one end of the
  power transformer primary, and to connect the live
  wire to a fuse, which is then connected to a power
  switch, which then connects to the other end of the
  power transformer primary.
   
  Is it likely the NZ power connection would be wired identically?


----------



## Doc B.

Yes, the IEC power cord socket is a universal kind of connector. You will just need to find an IEC style power cord with the proper plug for your local AC mains sockets.


----------



## Jimmy24

How does O2 compare with the Crack on HD 650's? Looking to upgrade to a Crack and possibly with speed ball but I'm not sure if it is worth the upgrade if I am only going to hear a slight difference.


----------



## liamstrain

Not sure there is an easy answer to that scjarrett87. Maybe you can find someone locally who has one you can audition? Are you in/near a major city?


----------



## skeptic

t.f.o.a said:


> What difference do you get when you upgrade the caps? Does it change the sound character? and is it really noticeable?




Yup - since the coupling caps are directly in the signal path in an otl amp, they do audibly change the sound, much akin to rolling tubes IMO. Two sets of *perfect caps, of identical spec and tolerance, and with "inaudible esr" would presumably sound the same, but I suspect you would have to spend big bucks to hit that threshold (assuming it can even be done from a manufacturing standpoint) when we are talking about quality film caps of ~100 uF and at least 250 V (as required in the crack output stage). The stock electolytics, axons, and obbligato's I've tried all do sound different from one another in the crack, and there are a couple of good threads on the topic on the bh forums where you can find more condensed info along these lines. 

Bob Crites also has a nice q&a style discussion regarding caps in relation to the xovers he makes for vintage klipsch speakers: http://www.critesspeakers.com/frequently-asked-questions.html.


----------



## T.F.O.A

is it possible to upgrade the caps right away when you're building it? how do you pick the upgrade caps? (sorry if it's sounds like a stupid question, but i'd rather get it all done on the 1st time then going back and redo some stuff)


----------



## BmWr75

Quote: 





t.f.o.a said:


> is it possible to upgrade the caps right away when you're building it? how do you pick the upgrade caps? (sorry if it's sounds like a stupid question, but i'd rather get it all done on the 1st time then going back and redo some stuff)


 
   
  How about going back one page in this thread and reading post 1376.


----------



## T.F.O.A

Quote: 





bmwr75 said:


> How about going back one page in this thread and reading post 1376.


 
  Hey thanks for the tip! Didn't realize it's only one page behind.


----------



## j123my

Whohooooooo~ I have just finished building my crack + speedball this morning. And it sounds aweeeessoommeeeee!! 
	

	
	
		
		

		
			




 Highs are crystal clear, mids are sweet, and bass, oh the bass is sooo tight and warm. Soundstage is, too, amazing. Feels like listening to a live concert 
	

	
	
		
		

		
		
	


	




. My HD600 has never sounded this good before.
   
  Is it weird if I enjoy looking at my crack? I smile every time I flip the chassis over, maybe somewhat proud that I have built this baby with my own hands..


----------



## longbowbbs

Gorgeous! Great point to point work. I love the braiding on the long cables!


----------



## networkn

Re Manual;
   
  Load Plate Resistors. Can I trim the ends on that and the LED Leads once I have soldered?
   
  My DMM doesn't have a clip lead, what else could I do to make the earth lead stay in place that won't affect the results?
   
  How much wire would you expect to have left over at the end of build?
   
  Thanks in advance.


----------



## j123my

Yes, once soldered you can just trim the leads. In fact, it is recommended not only for tidiness but also to prevent accidental shorting.
   
  For resistance measurement, you can just hold the ground/black probe by hand and use the other hand to move the red probe. You COULD do that for voltage measurement, but I don't recommend that! As Doc said in the manual, try not to work on a live equipment with both hands to reduce the possibility of getting shocked. You can try to use a paper clip or some other trick to hold ground probe in place.
   
  As for the wire, if you follow the manual and cut wires with lengths as specified, you'll have about a foot left once done. I don't think you need to cut more than what is said in the manual. Thanks to the mindful Doc, those are already pretty long such that you'll still make it even though you accidentally clip both ends when stripping the wires.


----------



## BmWr75

Quote: 





j123my said:


> Whohooooooo~ I have just finished building my crack + speedball this morning. And it sounds aweeeessoommeeeee!!
> 
> 
> 
> ...


 
   
  Beautiful work!!


----------



## j123my

Quote: 





longbowbbs said:


> Gorgeous! Great point to point work. I love the braiding on the long cables!


 
  Thanks, longbowbbs! To be fair, that is my third crack build. I have build 2 cracks for my friend before, so I already know what I am doing when I build mine. For the first one, I just followed the manual closely and got a pretty standard-looking crack:
   

   
  The wires given by the manual are somewhat long. Then on the second build I tried to measure the actual length from point to point and cut only what needed for a prettier look:
   

   
  It took me much longer (~18 hrs) to do since I have to re-measure everything, but I think it is well worth it, IMHO! 
	

	
	
		
		

		
		
	


	




 Then I think I am only getting better from there onwards. The third one took me only about 12 hrs to do (with speedball!)
  Anyway, I never thought building it to be that fun! I doubt that my crack will be the last crack I build. In fact if any head-fiers need help, I would consider helping them build one when I have time. Just PM me. But they should be warned: they'll be missing half of the fun!


----------



## longbowbbs

j123my,
   
  You effort is certainly worth it. This is one of the cleanest builds I have ever seen. Congrats on a job well done!


----------



## Cryok95

skeptic said:


> So I had a chance to do a little monkeying around with my crack over the holidays, including the installation of a pair of 100 uF / 400 V obbligato's in place of the 91 uF axons I was previously running as output caps. The folks in the bh forums weren't kidding about the easily audible improvement you can get from changing up these caps! Treble instruments are now totally grain free, and the bass response is bigger and better than it was with the axon's - although I imagine the latter has more to do with the change in capacitance than anything else (based on Doc et al.'s comments about expected bass roll off from using lower value caps).
> In any event, if any of you are looking for a <$100 upgrade with an obvious impact on sound quality, this is definitely worth considering and only takes about 10 minutes if you already have zip tie pads in place. Happy listening and new year to you all!





Wow so I guess you are using 100uf Obbligato PSU caps? Are they worth the price compared to the axon/solen 100uf caps?


----------



## skeptic

Quote: 





cryok95 said:


> Wow so I guess you are using 100uf Obbligato PSU caps? Are they worth the price compared to the axon/solen 100uf caps?


 
   
  I can't personally comment on the axon/solen 100uf caps.  I did my initial upgrade from the stock caps in the Spring of '11, after parts connexion had already sold out of their 100uf stock.  So I bought the 91uf version instead.  To my ears, the obbligatos are definitely worth the ~$50 premium over my old axons.  The sonic differences between these caps is about on the same order of magnitude as rolling various well made 12bh7's.  
   
  If you check out the cap comparison at www.humblehomemadehifi.com/cap.html , the author describes the axons as good budget caps, having a slight "focus in the lower treble range" and lacking in air and micro detailing.  I haven't compared very many different caps, and wouldn't try to describe the differences to this level of detail by ear even if I had.  But with the obbligatos, I am finding the trebles to be just a tad less prominent and more natural sounding (closer to live instruments) and that deep bass is improved in quality and quantity.  (Again, I assume the change in bass stems mostly from the 9uF increase in capacitance, as several of the threads on bh discuss how deep bass rolls off as you decrease the capacitance of your output caps.)  These were welcome changes from my perspective, particularly given that I spend the bulk of my listening time with hd800's (that do not require any added "focus" in the lower trebles).
   
  For example, in addition to my ordinary array of well recorded test tracks (e.g. k2hd jazz at the pawnshop and we get requests, simon&garfunkel - live in nyc, mfsl gold ella and louis again, chanticleer - evening prayer, songs for distingue lovers, etc.), I decided to throw on some 2pac (all eyez on me), to see if I was really hearing things right down low.  Lemme just say, the bass was hitting _hard_, in a good way - a way I did not expect to hear from flagship open Senns.  Needless to say, I'm really enjoying my crack these days!


----------



## networkn

I am wondering if someone could answer a couple of voltage testing stage questions for me?
   
  [size=small]How are you guys securing your rigs for the voltage checks? I can't find a stable way to do this? If I need to have in both of the tubes which are quite high, I can't rest it on the wood base (Which I haven't yet assembled) and I don't have a vice or anything.[/size]
   
  [size=small] I don't understand the instructions 5 and 6 on page 38. If I use the negative probe clip to connect to terminal 12, how can I connect the same lead to the ground buss?[/size]


----------



## GeorgeNapalm

Quote: 





networkn said:


> [size=small]How are you guys securing your rigs for the voltage checks? I can't find a stable way to do this? If I need to have in both of the tubes which are quite high, I can't rest it on the wood base (Which I haven't yet assembled) and I don't have a vice or anything.[/size]


 
  I put two thick flat markers on both sides between the top plate and the wood base closer to the transformer. That way the tubes didn't touch the table and I had access to the power switch. Or, you can put something under the wood base on both sides, like books. Be careful with the voltage checks. Remember to have your shoes on and put one hand in the pocket. And don't lean over live circuit! To be on the safe side I put on rubber gloves when I perform voltage checks.
   
   
  Quote: 





networkn said:


> I am wondering if someone could answer a couple of voltage testing stage questions for me?
> 
> [size=small]I don't understand the instructions 5 and 6 on page 38. If I use the negative probe clip to connect to terminal 12, how can I connect the same lead to the ground buss?[/size]


 
   
  Terminal 12 is connected to the ground.


----------



## kongmw

Quote: 





networkn said:


> I am wondering if someone could answer a couple of voltage testing stage questions for me?
> 
> [size=small]How are you guys securing your rigs for the voltage checks? I can't find a stable way to do this? If I need to have in both of the tubes which are quite high, I can't rest it on the wood base (Which I haven't yet assembled) and I don't have a vice or anything.[/size]


 
  I just used some plastic boxes lying around and put one under each corner of the face plate. Just make sure all the boxes are roughly the same height and all of them taller than the tallest tube you have on it. (But then I work in a bio/chem lab so I have more plastic pipette tip boxes than I care to admit 
	

	
	
		
		

		
			





)


----------



## j123my

I flipped the chassis over and let it rest on the wood base in a perpendicular direction, such that the power transformer and the 6080 tube is inside the base, and the 12AU7 is outside. Resting the chassis flush to the right gives you easy access to the power switch, which you will when checking the headphone out voltage during power-up/down.


----------



## Takaki

That custom crack in gold is stunning ;_:


----------



## Cryok95

Got my crack, realised the speedball boards were on backorder...
   
  Which is not a problem, except i just forwarded my crack amp from US to SG.
  So forwarding charges will apply again...


----------



## Cryok95

Just finished my amp. Sounds sweeeet. Will post pics soon!


----------



## rs01

I just got a UPS shipping notice from my order on Dec 13, I guess I know what I'm doing this weekend!


----------



## Cryok95

Listening to the crack with an rare amperex bugleboy 12au7. This tube is something special. Rolling around with other 12au7s also, but i prefer the amperex so far.
  RCA Cleartops are actually not too bad either. I have a mazda 12au7 coming also, does anyone here know how the mazda sounds?
   
  Will try a rca 12bh7a once my speedball boards arrive.
   
  TUBE ROLLING FTW.


----------



## Beefy

Quote: 





cryok95 said:


> TUBE ROLLING FTW.


 
   
  Meh. I've tried to enjoy tube rolling but I get REALLY bored REALLY fast. I'd much rather just sit and listen than try and analyse any possible differences.


----------



## Nixon

Just ordered mine, hope shipping it to the UK doesn't take too long.


----------



## Warrax

I see, HD600/HD650 + Crack is wonderfull combination. Anyone has tried HD700 + Crack combination yet? Will it fit same good too?


----------



## m17xr2b

Crack + HD700 = Heroin for me...it's that good.


----------



## Amarphael

Hi fellas, I need some advice about refining my formula ingridients
	

	
	
		
		

		
		
	


	



   
  I have an oppurtunity to  replace the output caps with 630v/10uF paper-in-oil Ampohms. They're 65mm in diameter and 95mm in length. Questions:
   
  1. Any info on the quality of the quality of these caps?
  2. I don't have any experience at dealing with installing such big caps, Do you think these would be hard to fit in the case?
  3. What would be the best value to compensate the output resistors for 600ohm 'phones? Would it have an eefect on the output impedance?
   
  I have the SB installed btw.


----------



## Beefy

Quote: 





amarphael said:


> I have an oppurtunity to  replace the output caps with 630v/10uF paper-in-oil Ampohms. They're 65mm in diameter and 95mm in length.


 
   
  10µF is far too small for the output caps. Your corner frequency with even 600ohm phones will be into the audible range (26.5Hz), meaning you will get pretty bad deep-bass roll off.
   
  Switching in, say, 300ohm phones in the future will be even worse, pushing the corner frequency to 53Hz.


----------



## Amarphael

Thanks for the heads up Beefy. Could you please enlighten me as to what formula I need to calculate the corner freq?


----------



## Amarphael

.


----------



## Beefy

Quote: 





amarphael said:


> Thanks for the heads up Beefy. Could you please enlighten me as to what formula I need to calculate the corner freq?


 
   
  http://www.muzique.com/schem/filter.htm
   
  The amp specifies 100µF, and you should try to stick to this value.


----------



## Amarphael

Great. Does paper-oil caps are any "better" than other types of film caps for this application? 
   
  Btw, do yo mind (or anyone) linking me to a nice budget cap, up to 10$,  from a retailer who does intl' orders?


----------



## BmWr75

Quote: 





amarphael said:


> Great. Does paper-oil caps are any "better" than other types of film caps for this application?
> 
> Btw, do yo mind (or anyone) linking me to a nice budget cap, up to 10$,  from a retailer who does intl' orders?


 
   
  You are not going to find any 100uF film cap for <=$10.  The cheapest I've seen was some AXON caps from Canada that ran about $25 each, but are no longer available.  You could parallel a 75uF and 22uF though, if you have the room.
   
  http://www.partsconnexion.com/capacitor_film_axon.html


----------



## Beefy

Quote: 





bmwr75 said:


> You are not going to find any 100uF film cap for <=$10.  The cheapest I've seen was some AXON caps from Canada that ran about $25 each, but are no longer available.  You could parallel a 75uF and 22uF though, if you have the room.
> 
> http://www.partsconnexion.com/capacitor_film_axon.html


 
   
  The Solen PA series at 91 or 100µF are virtually identical, and not much more expensive; people were buying the Axon instead because they were so cheap. But the Solen are now also OoS at PartsConnexion......


----------



## Hun7er

Nobody has experienced the bottlehead S.E.X vs Crack + Speedball upgraded ?


----------



## Amarphael

Those 75uF Axon's are doing 3.5hz corner freq by Beefy's link so i'm pretty fine with that. However is that the final load the amp sees? How is the interaction between the 'phones load and output resistors is figured, Is it combined or substracted from each other? Can't i play with the output resitor value to adjust to the Ampohm' btw?


----------



## Beefy

Quote: 





amarphael said:


> Those 75uF Axon's are doing 3.5hz corner freq by Beefy's link so i'm pretty fine with that. However is that the final load the amp sees? How is the interaction between the 'phones load and output resistors is figured, Is it combined or substracted from each other? Can't i play with the output resitor value to adjust to the Ampohm' btw?


 
   
  Good point, the bleeder resistor does have to be included for things to be accurate. This resistor makes less difference on typical 300ohm phones, so I completely forgot about it.
   
  The parallel resistance of the 2.49kohm and 600ohm phones decreases the apparent load to 483.5ohms. So your corner frequency is 4.4Hz. This is better than for a 91µF cap and 300ohm phones and should be AOK.


----------



## swmtnbiker

Hey all! Considering a Crack + Speedball and am wondering if anyone here has heard it compared with the Burson Soloist amping the HD-650? Any impressions on how the two amps stack up against each other out there?


----------



## uzi

Quote: 





swmtnbiker said:


> Hey all! Considering a Crack + Speedball and am wondering if anyone here has heard it compared with the Burson Soloist amping the HD-650? Any impressions on how the two amps stack up against each other out there?


 
   
  I have exactly that set of gear.  They've got their differences, as should be expected.  The best description I can give is "analog versus digital".  I'd compare the Soloist to listening to an SACD... very detailed, clean, precise and exact.  And likewise, I'd the Crack + Speedball to listening to vinyl... not as precise (but that's part of the charm), more warm and more fun.  I haven't gotten too much into tube rolling and I imagine there's a world of discovery in that, but I'm resisting the urge for the moment.
   
  They both have their strengths and shine at different things.  In general, I think the more analog/acoustic the recording the listen to, the more I'll favor it on the Crack+Speedball ... and the more digital, the more I'll favor the Soloist.  That said, there's a heap of overlap where I'm happy both ways (like the Stevie Wonder stuff I'm listening to at this given moment via the Crack + Speedball).
   
  My Soloist gets more use because the HD650 already has some warmth to it and I like the added detail.  I also always use my Denon AH-D2000 via the Soloist and never the Crack+Speedball.  It's simply a more versatile unit... but it also costs like twice as much.
   
  I wanted to have both solid state and tube options to play with, and I'm very happy in both cases.  Having one is not like having the other... so if you already have the Soloist and also want a tube amp, I certainly wouldn't discourage it.
   
  Edit: Just wanted to add that while the Soloist seems like it has more detail, the Crack+Speedball seems to have more depth.


----------



## swmtnbiker

Thanks a lot for your impressions. They pretty much echo what I'm experiencing with the Soloist and the Lyr, although I don't feel that the Schiit has more depth than the Burson. I've been pondering a Crack + Speedball for a while now and was wondering, if it was closer to the Soloist than the Lyr, if it would be worthwhile to grab one and give it a go. The Soloist certainly is a clean power beast (besides being HUGE), but as you mention it's twice the price. Decisions, decisions!!


----------



## Armaegis

Quote: 





hun7er said:


> Nobody has experienced the bottlehead S.E.X vs Crack + Speedball upgraded ?


 
   
  I've built both. Really, they're meant for different sets of headphones. Crack runs well with all the high impedance stuff. Sex does well with all the lower ones. Granted, at the time I compared them the best I had was a Sextett and a Beyer DT880 for high impedance, and a whole gamut of mid-fi low impedance ones.


----------



## uzi

Quote: 





swmtnbiker said:


> Thanks a lot for your impressions. They pretty much echo what I'm experiencing with the Soloist and the Lyr, although I don't feel that the Schiit has more depth than the Burson. I've been pondering a Crack + Speedball for a while now and was wondering, if it was closer to the Soloist than the Lyr, if it would be worthwhile to grab one and give it a go. The Soloist certainly is a clean power beast (besides being HUGE), but as you mention it's twice the price. Decisions, decisions!!


 
  The Lyr is a hybrid amp and definitely has some tubey goodness... but not to the amount that, say, Schiit's Valhalla did when I heard them side by side.  I'd sooner compare the Crack+Speedball to the Valhalla than to the Lyr.  Makes sense... they're both high impedance loving OTL amps.
   
  To circle back to your question... the Crack+Speedball would be more like the Lyr than the Soloist.


----------



## swmtnbiker

Quote: 





uzi said:


> The Lyr is a hybrid amp and definitely has some tubey goodness... but not to the amount that, say, Schiit's Valhalla did when I heard them side by side.  I'd sooner compare the Crack+Speedball to the Valhalla than to the Lyr.  Makes sense... they're both high impedance loving OTL amps.
> 
> To circle back to your question... the Crack+Speedball would be more like the Lyr than the Soloist.


 
   
  Yep, I'm aware of the design differences.


----------



## ben_r_

So what IS the Speedball upgrade exactly? Is it a linear power supply for the DC portion of the amp?


----------



## Beefy

Quote: 





ben_r_ said:


> So what IS the Speedball upgrade exactly? Is it a linear power supply for the DC portion of the amp?


 
   
  Erm, no.
   
  It is a constant current source (CCS) load for the tubes. Every tube must be 'loaded' with something to allow for current-to-voltage conversion. The default Crack has a resistor load, and replacing it with the Speedball CCS is a very solid improvement.


----------



## ben_r_

Quote: 





beefy said:


> Erm, no.
> 
> It is a constant current source (CCS) load for the tubes. Every tube must be 'loaded' with something to allow for current-to-voltage conversion. The default Crack has a resistor load, and replacing it with the Speedball CCS is a very solid improvement.


 

 Ah, yea I was way off there. Thanks. Just never done any circuit design with tubes before so Im pretty uninformed on them as a whole. Time to do some fundamental reading.


----------



## Dgiant

Hi, I was planning on buying this kit, however I have no experience with soldering and DIY. Will I be able to build this kit without much problem?


----------



## RonO

Quote: 





dgiant said:


> Hi, I was planning on buying this kit, however I have no experience with soldering and DIY. Will I be able to build this kit without much problem?


 
  Based on my own experience, I think anyone willing could build this kit. The manual is very good.  They key to the build is being patient and double checking your work. I'd recommend you get a variable soldering iron rather than just a fixed wattage. Cooler temps worked well for the Speedball, with it's thin gauge wires, and higher temps were needed for some of the terminals with 2 or more attachments. Don't forget to allocate thought and time for the box and top plate.  Unless you go with a "naked" unfinished build, you'll need to sand, stain/paint etc. In my own case I spent nearly as much time getting the finish on my wood box to my satisfaction as I did on soldering up the kit.


----------



## amcananey

Supposedly the best tube for the Crack is a GEC 6AS7G. These normally go for $150-$200. If anyone is interested in buying one *with* me for substantially less, please PM me. I've got +99 feedback here on Head-Fi.
   
  I apologize for posting this here, but I figured I was more likely to find someone interested in joining me here.
   
  Best regards,
  Adam


----------



## ben_r_

Quote: 





amcananey said:


> Supposedly the best tube for the Crack is a GEC 6AS7G. These normally go for $150-$200. If anyone is interested in buying one *with* me for substantially less, please PM me. I've got +99 feedback here on Head-Fi.
> 
> I apologize for posting this here, but I figured I was more likely to find someone interested in joining me here.
> 
> ...


 

 How much is "substantially less"? And why is it the best tube?


----------



## ben_r_

Quote: 





doc b. said:


> We do sell the chassis plate for $45, but we don't sell that particular power transformer (PT-3) due to our agreement with the designer. We have a very similar transformer, the PT-7, that differs only in having a single high voltage secondary winding rather than two windings that are each rated for half as much current in the PT-3. I'm out of town until next week and don't have access to the prices, but I think it is around $80 or $90.


 

 Hey Doc, this quote was from a post you made quite a while ago, but Im curious again about this PT-7 so I had another quick question about it:
   
  If the PT-7 lacks the secondary high voltage winding thats the PT-3 has (at half the current) does that mean that when using the PT-7 the high voltage output terminals are already twice the current of one of the two outputs that the PT-3 has but are still at the 150v output that the PT-3 is? In other words in a Crack build the two high voltage output terminals are wired in parallel, to double the current Im assuming, so when using the PT-7 there wouldnt be a need for that and the single output terminals would be used instead giving something near 150V near 70mA?


----------



## Doc B.

Yes, that is correct. Just a note - I don't make it over here as often as our own forum, so my response time (or that of the other technical guys) on technical stuff might be shorter on the Bottlehead Forum.


----------



## Nixon

Does anyone know how long these usually take to ship?


----------



## snip3r77

Quote: 





doc b. said:


> There are a couple of threads going at once about this kit in different forums. Forgive me if this seems redundant to anyone following both threads - in the other one I mentioned that yes, this is really intended for high impedance cans, but it will work with low impedance cans though not optimally. I also mention that we have another kit with a low output impedance that works very well with low impedance headphones, so I felt we could afford to do this second, more focused design for the high impedance phone users.


 
  Hi Doc, which amp would then be suitable for the Hifiman HE-500?


----------



## amcananey

Quote: 





snip3r77 said:


> Hi Doc, which amp would then be suitable for the Hifiman HE-500?


 
   
  You want the S.E.X. for the HiFiMAN HE-500. But if you have any high impedance headphones (Senn HD600, HD650, HD700, HD800, or the 250 or 600 Ohm versions of the Beyer DT770, DT880 or DT990s, or the Beyer T1s), then I *highly* recommend the Crack. I have owned a fully-balanced, top-of-the-line, no-holds-barred, fully premium Beta 22, a Woo Audio WA22 with $600 worth of tube upgrades, and a WA6 with just about every tube imaginable, and the combination of the Crack with any of my Senn HD600s, HD800s or my Beyer DT990s 600 Ohm smoked all of them. Not even close.
   
  I haven't heard the S.E.X., and I'm sure it's very good, but don't just default to the more versatile tool. Sometimes a highly specialized tool can perform better (but in this case only if you have high impedance cans).
   
  Best regards,
  Adam


----------



## ben_r_

Quote: 





amcananey said:


> You want the S.E.X. for the HiFiMAN HE-500. But if you have any high impedance headphones (Senn HD600, HD650, HD700, HD800, or the 250 or 600 Ohm versions of the Beyer DT770, DT880 or DT990s, or the Beyer T1s), then I *highly* recommend the Crack. I have owned a fully-balanced, top-of-the-line, no-holds-barred, fully premium Beta 22, a Woo Audio WA22 with $600 worth of tube upgrades, and a WA6 with just about every tube imaginable, and the combination of the Crack with any of my Senn HD600s, HD800s or my Beyer DT990s 600 Ohm smoked all of them. Not even close.
> 
> I haven't heard the S.E.X., and I'm sure it's very good, but don't just default to the more versatile tool. Sometimes a highly specialized tool can perform better (but in this case only if you have high impedance cans).
> 
> ...


 

 What about the WA3? Have you compared it to the Crack with the HD-600's?


----------



## Beefy

Quote: 





ben_r_ said:


> What about the WA3? Have you compared it to the Crack with the HD-600's?


 
   
  Technically speaking, the stock Crack is pretty similar to the WA3. However a Crack with speedball spanks the WA3 in 64 different ways. Add some custom upgrades like a nicer pot, output caps, etc. and you are even further ahead.


----------



## ben_r_

Quote: 





doc b. said:


> Yes, that is correct. Just a note - I don't make it over here as often as our own forum, so my response time (or that of the other technical guys) on technical stuff might be shorter on the Bottlehead Forum.


 

 Cool. Im kinda thinking I want to use the PT-7 in my Crack build as I have read around the audio forums that its a better transformer than the PT-3. Im just a little concerned with how much I would have to alter the circuit to accommodate it. However if its as simple as omitting the wiring from terminals 6 and 7 to 9 and 10 on the PT-3 (shown on page 26 of the manual) then I'd be good to go to use the PT-7. Can you confirm thats all it would be, or are we talking more in depth circuit alterations here?


----------



## amcananey

I have the Speedball in my Crack (ermmmm.......somehow that doesn't sound right).
   
   
  In any case, even the stock Crack sounds wonderful. I'm not just some fanboy, and I'm not talking without having a good basis for comparison. I own, or have owned, the following:
   
  HiFiMAN EF-6
  Violectric V181
 Woo Audio WA22 w/ Princess Sophia, Sylvania brown base driver tubes and Sylvania power tubes
 Woo Audio WA6 w/ Princess Sophia and various driver/power tubes and adapters
 Balanced ß22 (Beta 22) with dual Sigma 22 power supplies
  Burson HA-160D
  SinglePower MPX3 Slam
  Audio-Gd NFB-10SE
  Trends TA-10.2SE
  AMB M³ (a/k/a M^3 or MMM)
 HiFiMAN EF-5
 Eddie Current Laconic EC-01
 K.I.C.A.S. Caliente
  Objective O2
  Beresford Caiman w/ Gator Board and Burson discrete opamp
  Graham Slee Novo
 Meier Corda Move
 Meier Corda Headamp-1
 Neco Soundlab BOSFET v2.1 (PCB v7)
 Neco Soundlab v3 Portable (18V w/ battery upgrade)
 Neco Soundlab Mosfet

 And many more besides (yes, I'm serious). The best amp I have heard for my HD800s / HD600s / DT990s (600 Ohm) is the Bottlehead Crack + Speedball. The EF-6 and Violectric V181 are also very good, but the Crack + Speedball is the best I've heard so far.
   
  I'm expecting to receive a Little Dot Mk VI+ tomorrow, maybe that's better, but it seems unlikely. Maybe an Eddie Current Zana Deux would be better - that seems plausible. I've been trying to convince the Bottlehead team to develop a no-holds-barred OTL headphone amp, and they are considering it, but it's not as though the Crack + Speedball has any glaring flaws as-is. And with the money you save vs. other offerings, you can upgrade the tubes or other compotents (e.g., insert film caps or an upgraded volume pot). I don't have either in my Crack yet (just the Speedball), so it's not as though you need those things for the Crack to sound great. Moreover, note that great tubes for the Crack don't cost a fortune. A Tung-Sol 5998 will cost you $85. And the smaller tube variants are all less than $50, even for the most sought-after versions.
   
  Plus, you can customize the look of your Crack and make it look awesome. The kit is easy to build, even if you've never done this kind of stuff before (a little bit of experience soldering is helpful, but not strictly necessary). I did it in two nights.
   
  Best regards,
  Adam


----------



## Doc B.

Quote: 





ben_r_ said:


> I have read around the audio forums that its a better transformer than the PT-3.


 
  The PT-7 is simply more idiot-proof. PJ was always worried that someone was going to DIY some homebrew circuit with the PT-3 and not have enough knowledge to understand that they couldn't wire the two bifilar high voltage secondaries in _series_ without smoking them. Those separate secondaries were put in the PT-3 for a specific design that was improved recently and in the process a PT-7 was spec'd for the sake of simplicity. But the PT-3 with HV secondaries wired in _parallel_ functions the same as the PT-7 would in the Crack.


----------



## ben_r_

Quote: 





doc b. said:


> The PT-7 is simply more idiot-proof. PJ was always worried that someone was going to DIY some homebrew circuit with the PT-3 and not have enough knowledge to understand that they couldn't wire the two bifilar high voltage secondaries in _series_ without smoking them. Those separate secondaries were put in the PT-3 for a specific design that was improved recently and in the process a PT-7 was spec'd for the sake of simplicity. But the PT-3 with HV secondaries wired in _parallel_ functions the same as the PT-7 would in the Crack.


 

 Gotcha. That makes sense. I thought I had remembered reading somewhere that the PT-7 was actually a quieter transformer as well, but I could have been thinking of something else. I get so overloaded with all the stuff I read that in the end I just end up confusing myself sometimes! lol


----------



## Hibuckhobby

New Crack head here.  Just got mine today and I have to admit, it's better than I expected.
  I have a number of "decent" amps:  WA2, WA6, Headroom Home and even without much 
  time to burn in, the Bottlehead doesn't take a backseat to any of them.  This is flat out, the
  best my Senn HD 600's have ever sounded.  Diana Krall is simply intoxicating.
  Hibuck....


----------



## Jmstrmbn

Quote: 





hibuckhobby said:


> New Crack head here.  Just got mine today and I have to admit, it's better than I expected.
> I have a number of "decent" amps:  WA2, WA6, Headroom Home and even without much
> time to burn in, the Bottlehead doesn't take a backseat to any of them.  This is flat out, the
> best my Senn HD 600's have ever sounded.  Diana Krall is simply intoxicating.
> Hibuck....


 
  What DAC are you using the crack with?  I am using mine with the Nuforce HDP and feel that the Crack is ahead of it but only a little and I feel it might be time for a dedicated DAC.


----------



## ben_r_

Quote: 





jmstrmbn said:


> What DAC are you using the crack with?  I am using mine with the Nuforce HDP and feel that the Crack is ahead of it but only a little and I feel it might be time for a dedicated DAC.


 

 That is what I was planning to use as well. What DAC are you looking at getting that youre expecting to be a better pairing?


----------



## Jmstrmbn

I haven't really started looking since I don't have the money right now but have read good things about the Schiit Gungir, it seems reasonable for the price.


----------



## lextek

Quote: 





hibuckhobby said:


> New Crack head here.  Just got mine today and I have to admit, it's better than I expected.
> I have a number of "decent" amps:  WA2, WA6, Headroom Home and even without much
> time to burn in, the Bottlehead doesn't take a backseat to any of them.  This is flat out, the
> best my Senn HD 600's have ever sounded.  Diana Krall is simply intoxicating.
> Hibuck....


 
  Bingo!


----------



## Hibuckhobby

I'm going old school with a PSAudio DLIII.  Been very happy with it.
  For me, detail is important, but tonality is most important.
  Hibuck....


----------



## Draygonn

hibuckhobby said:


> This is flat out, the best my Senn HD 600's have ever sounded.  Diana Krall is simply intoxicating.


Yessss... the Crack works magic with Senns. Have you got some TS5998s yet?


----------



## swmtnbiker

Question for you Crack/Speedball owners - what's your gain like? I purchased a pre-built Crack + Speedball and am still trying to pick my jaw up off the floor after hearing how ungodly good this amp pairs with my HD-650. Damn. BUT, I'm barely getting the volume pot to the 8:00 position before it becomes too loud. This amp was designed for high impedance cans, so that kind of gain just seems off to me for a 300 ohm headphone. Any ideas? Or am I just a dunce?


----------



## Draygonn

swmtnbiker said:


> Question for you Crack/Speedball owners - what's your gain like? I purchased a pre-built Crack + Speedball and am still trying to pick my jaw up off the floor after hearing how ungodly good this amp pairs with my HD-650. Damn. BUT, I'm barely getting the volume pot to the 8:00 position before it becomes too loud. This amp was designed for high impedance cans, so that kind of gain just seems off to me for a 300 ohm headphone. Any ideas? Or am I just a dunce?


That's normal. I use 12DB inline attenuators with my 650s to get the pot to a desirable position away from the channel imbalance.

Glad you are experiencing the Crack goodness


----------



## swmtnbiker

Thanks Draygonn. I'll look into a pair. Where did you get yours if you don't mind me asking?
   
  I'm sure this has already been discussed to death concerning the Crack, but I find it mystifying that the gain issue hasn't been addressed in the design. This amp is specifically targeted at high impedance headphones. It seems weird that I'd have to add kludgy inline attenuators to get an acceptable gain level with the very type of headphone the amp is engineered to drive.


----------



## Draygonn

swmtnbiker said:


> Thanks Draygonn. I'll look into a pair. Where did you get yours if you don't mind me asking?


http://www.amazon.com/Harrison-Labs-Line-Level-Attenuator/dp/B0006N41B0/ref=sr_1_1?s=electronics&ie=UTF8&qid=1360288707&sr=1-1

They are one-way. I had them connected improperly the first time and had a weird echo effect with some tunes.


----------



## swmtnbiker

Yep, I found the Harrisons with a quick search. Thanks!
   
  BTW, I don't mean to sound whiney about the gain issue. The Crack + Speedball flat-out rocks the HD-650. Everyone who's posted about what a great combo this is has been 100% right all of these years.


----------



## Doc B.

Quote: 





swmtnbiker said:


> Yep, I found the Harrisons with a quick search. Thanks!
> 
> BTW, I don't mean to sound whiney about the gain issue. The Crack + Speedball flat-out rocks the HD-650. Everyone who's posted about what a great combo this is has been 100% right all of these years.


 
  What's your source output level?


----------



## swmtnbiker

Quote: 





doc b. said:


> What's your source output level?


 
   
  Hi Doc! I'm feeding the Crack with a Channel Islands Audio VDA-1 DAC and can't find the specs for it any longer. It's successor, the VDA-2, is rated at 2.25 vRMS. I will assume that the VDA-1 is the same.
   
  EDIT: The VDA-1 outputs 2.4 vRMS.


----------



## BmWr75

Quote: 





draygonn said:


> http://www.amazon.com/Harrison-Labs-Line-Level-Attenuator/dp/B0006N41B0/ref=sr_1_1?s=electronics&ie=UTF8&qid=1360288707&sr=1-1
> 
> They are one-way. I had them connected improperly the first time and had a weird echo effect with some tunes.


 
   
  So do these attenuators go in-line on the inputs of the Crack?


----------



## swmtnbiker

Quote: 





bmwr75 said:


> So do these attenuators go in-line on the inputs of the Crack?


 
   
  Yes.


----------



## Hibuckhobby

[RIGHT[/RIGHT]





draygonn said:


> Yessss... the Crack works magic with Senns. Have you got some TS5998s yet?




Not yet, but have tried 1939 vintage 6SA7's. This thing is so close to the amp I bought from you that I may sell that amp, add a speedball and call it good.
Hibuck...


----------



## ben_r_

So what caps are you guys upgrading to now that the Aeon ones are gone (they are gone right?)


----------



## Doc B.

Quote: 





swmtnbiker said:


> Hi Doc! I'm feeding the Crack with a Channel Islands Audio VDA-1 DAC and can't find the specs for it any longer. It's successor, the VDA-2, is rated at 2.25 vRMS. I will assume that the VDA-1 is the same.
> 
> EDIT: The VDA-1 outputs 2.4 vRMS.


 
  Yeah that would be part of the issue then. Way back in the olden days there were things called standards. This is black art stuff now, no one understands them in the 21st century. But back when these strange things called CDs first came out the people who made players for them said the output level should be 2V. Pretty soon others figured out that if their player was louder, people thought it sounded better. And so output levels kept rising. IIRC one of the craziest was the Art Audio DIO which had like 7V output. To further confound this, the standard for phono playback is 0.5V. And back in the day the standard for cassette tape playback was something like 150mV!
   
  Also, bear in mind that Crack has to be able to work with 600 ohm cans too. They will usually require the volume knob level to be set higher than lower impedance cans. So between the differences in source output levels and headphone sensitivity, volume control settings are really a moving target. But hey, that's why the knob turns.


----------



## liamstrain

Aye - since I use a computer as the primary source (feeding into the D100), I use the pre-amp there to attenuate - the Crack can get loud with my HD-600s. 
   
  But what a great pairing.


----------



## swmtnbiker

doc b. said:


> Yeah that would be part of the issue then. Way back in the olden days there were things called standards. This is black art stuff now, no one understands them in the 21st century. But back when these strange things called CDs first came out the people who made players for them said the output level should be 2V. Pretty soon others figured out that if their player was louder, people thought it sounded better. And so output levels kept rising. IIRC one of the craziest was the Art Audio DIO which had like 7V output. To further confound this, the standard for phono playback is 0.5V. And back in the day the standard for cassette tape playback was something like 150mV!
> 
> Also, bear in mind that Crack has to be able to work with 600 ohm cans too. They will usually require the volume knob level to be set higher than lower impedance cans. So between the differences in source output levels and headphone sensitivity, volume control settings are really a moving target. But hey, that's why the knob turns.


 

   
  Thanks for the feedback Doc. While I agree that you can't possibly accommodate all possible scenarios, it still seems to me that perhaps the design of the Crack might be a bit more forgiving in this respect. For example, I've recently spent quite a bit of time comparing other DACs to my VDA-1, including the Schiit Audio Bifrost and Modi, the HRT Music Streamer II, and the ODAC using the Schiit Asgard, Lyr, and Magni for amplification as well as the Matrix Audio M-Stage and and the Burson Soloist. All of the above mentioned DACs had line-level output so close to the VDA-1 that I rarely had to make a volume change when swapping them out, and when I did it was minimal. With that large a sampling of contemporary DACs, the 2.4 vRMS output of the VDA-1 seems to be well within the industry norm. My issue with the gain on the Crack and the HD-650 is that I'm barely getting the volume pot up to 1/6th of its range before it's too loud. Does that work? Surely, but I think that a more realistic gain level would allow me to move it up to 9:00 or even 10:00 for a 300 ohm load. That would leave plenty of headroom for higher impedance cans and it would also get the volume pot out of potential channel imbalance territory.
   
  Of course I may be almost completely clueless too. This is just my two cents. As I've said I love love LOVE the way the Crack + Speedball sounds with my Senns. If this gain issue continues to be a problem for me I'll probably end up doing what others have done, get a pair of 12dB attenuators, and deal with it. Just wish I didn't have to go that route or incur the additional expense. If you have any alternative suggestions or can point me to any I'd be grateful.
   
  Thanks for listening.


----------



## Doc B.

I'm chuckling because two weeks ago we had a long thread on the Bottlehead Forum a guy who said Crack didn't have _enough_ gain. I just want to know which one of you guys is right?!!
   
  Part fo the the reason the Crack sounds good is the simple direct coupled circuit. There are very few tube combos that will work for this and almost all have more gain, not less. So the best bet is to adjust the source level. If you can trim the output of your music server in the software, that is one solution. The in-line attenuators are another. And of course they are not rocket science, you can look online and find info about making a voltage divider that you could build into the input. Simplest thing to start with might be putting a 100K resistor between the input jack and the volume pot.


----------



## swmtnbiker

Quote: 





doc b. said:


> I'm chuckling because two weeks ago we had a long thread on the Bottlehead Forum a guy who said Crack didn't have _enough_ gain. I just want to know which one of you guys is right?!!


 
   
  Why, I am, of course! 
	

	
	
		
		

		
		
	


	



   
  Seriously though, thanks for the suggestions. Since I subscribe to the "purest path possible" line of thinking I'll probably just live with it as-is.


----------



## BmWr75

I have a Crack + Speedball with 100uF P-E film caps installed.  It is fed by an AppleTV playing lossless files through an Emotiva X-DAC1.  The main cans I use with it are Beyerdynamic T-70s.
   
  The same source feeds a PrimaLuna Dialogue Two tube integrated amp and ADS L1230 speakers.
   
  The headphone set up absolutely slays the speaker set up.  I can switch back and forth between the two easily.  The results are not even close and I have the L1230s set up decently in the listening room.
   
  The Crack is amazing with some certain cans and good source material.


----------



## TheKillerPiglet

I received a Crack with Speedball from a fellow hf member, and it seems it did not travel well.
   
  I was going to post this on the BH forums, but my account has not been verified and I woudl like to start working on a resolution.
   
  The problem is that the right channels does not play. The problem is not with the small signal tube, but I will not have a spare power tube to test with until Thursday.
   
  Looking at the undersides of the amp, the top arrow hows a loose connection. Tapping this will cause the LED's in the SB to turn off/on.
   
  The second arrows shows a pair of LED's that will not turn on, I think it is safe to assume this relates to the dead channel.
   
  I do not have any schematics or assembly manuals, not sure if these are available online.
  Any advise woudl be appreciated.
   
  (I had to remove  the image else the entire post goes invisible. Imagine, if you will, an  elegant and graceful blue dashed arrow pointing to the cap near the RCA inputs while its equally graceful but slightly less elegant twin leads the intrepid viewer's vision to the LED's by the lower heat sink on the speed ball)
   
  KP


----------



## TheKillerPiglet

Well, that was creepy, my post and its image disappeared after saving. If I edit the post it's all there, but after Submit it goes blank.
   
  KP


----------



## j123my

> Looking at the undersides of the amp, the top arrow hows a loose connection. Tapping this will cause the LED's in the SB to turn off/on.


 
   
  Sounds like bad solder joint(s) to me.. Easiest fix would be to send it back to the original owner and ask him to fix that 
	

	
	
		
		

		
			





 Or you could try to reheat the solder joints and see if that fix the intermittent LED problem. Swapping both tubes is also a good idea, since most problems can be traced to a bad tube.
   
  BTW you might have known this, but be careful when tapping on things while the amp is on! There are high voltages there. If I have the correct picture in my mind, you are pointing to the first cap in the power supply just next to the diode bridge, and if I remember correctly that cap has about ~200V on it.
   
   
   


> I do not have any schematics or assembly manuals, not sure if these are available online.
> Any advise woudl be appreciated.


 
  Again, the previous owner is your best bet here. As far as I know, the manual is only distributed in a CD when you buy the kit and is not available online for copyright reasons.


----------



## TheKillerPiglet

Thank you for the reply.
   
  This amp was originally assembled by BH, my understanding is that it was the first to use the speedball.
   
  To clarify, the set of LED's near the lower heat sink never turn on even when the other do. The bad solder joint seems simple enough, the dead right channel less so unless it's a bad tube.
   
  KP


----------



## j123my

> my understanding is that it was the first to use the speedball.


 
  That sounds familiar.. 
	

	
	
		
		

		
		
	


	



   
  Well, I'd do the following (in order, proceed only if the previous step did not solve the problem):

 Reflow all suspicious joints (if you have the manual, you can do the resistance check to narrow down the potential problematic joints)
 Swap the driver tube when you have it with you.
 Get the manual, do voltage checks, and post the results on BH forum. The experts there should be able to tell you what went wrong by looking at those numbers.
 If the issue is still not solved, cry.


----------



## TheKillerPiglet

I don't know if it sheds any light but the right channel went out when I swapped cans. Hopefully the tube just shorted.
   
  KP


----------



## Jmstrmbn

Top View: Copper Hammertone with a Golden Oak Finish
   
   
   

   
  Under the hood: totally stock except for some heat shrink over some of the exposed leads.
   
  Can't believe how great this sounds with the HD600s.  Compared to the Nuforce HDP they sound like a totally new headphone, I didn't expect this kind of difference for this price.


----------



## ben_r_

Quote: 





jmstrmbn said:


> Top View: Copper Hammertone with a Golden Oak Finish
> 
> 
> 
> ...


 
  Are you using the HDP as a DAC for the setup now?


----------



## Jmstrmbn

Yes I have it pre-amping the Crack now and it works well but I can't but feel a dedicated DAC would perform better.


----------



## ben_r_

Quote: 





jmstrmbn said:


> Yes I have it pre-amping the Crack now and it works well but I can't but feel a dedicated DAC would perform better.


 
  I hear ya. I Have the HDP and an ASUS Xonar Essence ST now and am thinking about buying an HRT Music Streamer II and an ODAC so that I can do a little comparison of my own.


----------



## TheKillerPiglet

Ebay seller shipped like greased lightning, turns out to be bad tube.
  Thank you, j123my.
   
  Yay.


----------



## j123my

> Ebay seller shipped like greased lightning, turns out to be bad tube.
> Thank you, j123my.


 
  You should thank the ebay seller instead 
	

	
	
		
		

		
		
	


	



  Bad tube is a *very* common problem. It is a good idea to have some spare tubes lying around, just in case..


----------



## TheKillerPiglet

Quote: 





j123my said:


> You should thank the ebay seller instead
> 
> 
> 
> ...


 

 Oh I did.
  I have stockpiles of various tubes but this 6080 family is new to me. Let the hoarding begin.
   
  KP


----------



## greyhorse

Does anyone know how the Crack compares with the Bijou for use on HD650s?
  I already have all the parts to build the Bijou, so this will get built for sure, but I am wondering if I need to try the Crack as well.
  So far I am listening with the EHHA, and the HD650s sound boring.  Thanks for any info.


----------



## eganz

dpipple - To change the range of the volume pot, a simpler solution is to install some padding resistors before the volume pot. 50 Or 100 kohm Should do the trick.


----------



## Beefy

Quote: 





eganz said:


> dpipple - To change the range of the volume pot, a simpler solution is to install some padding resistors before the volume pot. 50 Or 100 kohm Should do the trick.


 
   
  You don't want to just increase this too much though, because it introduces noise. My solution was to use a 50k pot with a 50k resistor, for the same 100k input impedance.


----------



## swmtnbiker

Quote: 





eganz said:


> dpipple - To change the range of the volume pot, a simpler solution is to install some padding resistors before the volume pot. 50 Or 100 kohm Should do the trick.


 
   
  I'm no DIYer, have no tools, and no electronics fabrication or soldering skills. My Crack was built by someone else (who did a supreme job BTW!). My solution was to buy a pair of Harrison Labs 12dB line-level attenuators. They'll be here on Friday, so I don't have long to wait to see if they do the trick without compromising sound quality.


----------



## GrindingThud

OK, I'm looking at committing apostacy and install portions of the crack speedball kit into my WA3. The two amps are very similar, with exception of maybe the B+ and tube bias points. They both use 6AS7 output tubes with simple cathode follower resistor bias...crack with 3K and WA3 with 1.5K. My question is if the speedball instructions contain enough information for me to choose proper resistor values to match my current Woo bias? With 193V on my plate, I'm seeing about 35V on the cathode. Thoughts?


----------



## ben_r_

Quote: 





grindingthud said:


> OK, I'm looking at committing apostacy and install portions of the crack speedball kit into my WA3. The two amps are very similar, with exception of maybe the B+ and tube bias points. They both use 6AS7 output tubes with simple cathode follower resistor bias...crack with 3K and WA3 with 1.5K. My question is if the speedball instructions contain enough information for me to choose proper resistor values to match my current Woo bias? With 193V on my plate, I'm seeing about 35V on the cathode. Thoughts?


 

 Thoughts? You probably wont find much help here on the matter, but you should check out this thread: LINK


----------



## jhamdg

Quote: 





swmtnbiker said:


> I'm no DIYer, have no tools, and no electronics fabrication or soldering skills. My Crack was built by someone else (who did a supreme job BTW!). My solution was to buy a pair of Harrison Labs 12dB line-level attenuators. They'll be here on Friday, so I don't have long to wait to see if they do the trick without compromising sound quality.


 
  Hi,
   
  Can you tell me who build your amp? I'm new to this forum. Just got a pair of HD650, a step up from Audio Technica M50. I am interested in this crack amp but I am too not a DIY person... Thanks!


----------



## swmtnbiker

Quote: 





jhamdg said:


> Can you tell me who build your amp? I'm new to this forum. Just got a pair of HD650, a step up from Audio Technica M50. I am interested in this crack amp but I am too not a DIY person... Thanks!


 
   
  Check out the Amplification For Sale Forum here, and your PM.


----------



## amcananey

Has anyone tried one of the Psvane 12AU7s or CV181s/6SN7s (using a 6SN7 adapter)? If so, what are your impressions?

 Best regards,
 Adam


----------



## Jmstrmbn

Been toying with the idea of getting an HE-500 recently however I don't really have an amp to drive them (Nuforce HDP, Crack).  If any of you own the Crack and the 500s can you give the combo a green light?
   
  Thanks in advance for the help.


----------



## TheKillerPiglet

No! Red light, flashing lights, helicopters overhead, children screaming, mothers running away with baby strollers, some open mouthed fat guy dropping a hotdog.
   
  Serious distortion.
   
  KP


----------



## Armaegis

Not the Crack, no... but the HDP should be good to go. 
   
  I don't have an HE-500, but I have an HE-6 and the HDP does surprisingly well with it. If it can handle the HE-6, I think the HE-500 will be ok. If not, it will still be enjoyable and you can always upgrade later.
   
  I actually have my HDP feeding into the Nuforce Icon speaker amp to drive my HE-6. It's a nice little combo.


----------



## liamstrain

Quote: 





jmstrmbn said:


> Been toying with the idea of getting an HE-500 recently however I don't really have an amp to drive them (Nuforce HDP, Crack).  If any of you own the Crack and the 500s can you give the combo a green light?
> 
> Thanks in advance for the help.


 
   
  No. The crack is optimized for high voltage. The HE-500 need high current. Build the Smack or Sex (or any number of other fine designs), but not the Crack for this headphone.


----------



## FraGGleR

Quote: 





liamstrain said:


> No. The crack is optimized for high voltage. The HE-500 need high current. Build the Smack or Sex (or any number of other fine designs), but not the Crack for this headphone.


 
  I haven't heard the Crack, but I do have a S.E.X. and it does wonderful things with my LCD-2s and with the HE-500s I originally auditioned it on.  It also does a very good job with my HD650s and HD800s.  I am thinking about building a Crack just to compare the two.


----------



## Doc B.

Yes, we recommend the S.E.X. amp for Audeze, HiFiMan and AKG K1000s.


----------



## j123my

That makes me want to build the S.E.X, sounds like gonna be fun.... No, no!! Must.. resist.. temptation...


----------



## wazzupi

http://www.youtube.com/watch?v=rpJ73JmT9HA I want to know what you guys think listening to this song with the hd650's !


----------



## wazzupi

Quote: 





j123my said:


> That makes me want to build the S.E.X, sounds like gonna be fun.... No, no!! Must.. resist.. temptation...


 
  must ...resist.... the temptation.... of s.e.x.


----------



## lextek

Quote: 





amcananey said:


> Has anyone tried one of the Psvane 12AU7s or CV181s/6SN7s (using a 6SN7 adapter)? If so, what are your impressions?
> 
> Best regards,
> Adam


 
  I've tried some 6SN7 tubes with an adapter.  Very, pleased with the sound.  To me they seemed to open up the soundstage.  Kind of a "bigger" sound. I have an old Motorola in there now.


----------



## Mak333

Maybe it's just me, but I've tried a Tung-Sol 6080 (JAN-CTL-6080) that Bottlehead supplied with the Crack amp, and I've also tried a NOS RCA 6AS7G.
   
  The RCA 6AS7G doesn't have the musicality that the 6080 does.... I know other listeners like 6AS7G tubes, but maybe I need to try a different brand or variant.  The Tung-Sol 6080 just seems to have more overall musicality and provides a little more low-end than the 6AS7G from what I can tell.


----------



## swmtnbiker

Where did you get your adapter if you don't mind me asking?


----------



## lextek

Quote: 





swmtnbiker said:


> Where did you get your adapter if you don't mind me asking?


 
  Ebay


----------



## swmtnbiker

Thanks!


----------



## TheKillerPiglet

I really do like the 6sn7's quite a bit in this amp. Running a chrome top Sylvania right. Seems you really can't wrong with any decent 6sn7 in this position.
   
  KP


----------



## amcananey

Quote: 





swmtnbiker said:


> My solution was to buy a pair of Harrison Labs 12dB line-level attenuators. They'll be here on Friday, so I don't have long to wait to see if they do the trick without compromising sound quality.


 
   
  I just bought a pair of these. They work perfectly. And it may just be my imagination, or it may be the fact that I also installed a new TDK volume pot and the attenuators let me set it to work within its sweet spot, but I actually find that my system sounds better now. The treble isn't quite as hot, making the amp very relaxing to listen to. In any case, the Harrison attenuators are highly recommended.
   
  Best,
  Adam


----------



## ben_r_

Quote: 





amcananey said:


> I just bought a pair of these. They work perfectly. And it may just be my imagination, or it may be the fact that I also installed a new TDK volume pot and the attenuators let me set it to work within its sweet spot, but I actually find that my system sounds better now. The treble isn't quite as hot, making the amp very relaxing to listen to. In any case, the Harrison attenuators are highly recommended.
> 
> Best,
> Adam


 

 You guys are using those coming out of what source again?


----------



## amcananey

I'm using an Audio-Gd Ref. 5.32. It puts out 2.5V over RCA.


----------



## ben_r_

Quote: 





amcananey said:


> I'm using an Audio-Gd Ref. 5.32. It puts out 2.5V over RCA.


 

 Huh, I have an HRT Music Streamer II and the manual says it outputs 2.25V. Maybe Ill pick up the 6dB Attenuator and give it a try. Hell Ill just order both the 6dB and 12dB just to have since my gear rotates so frequently its good to have both around!


----------



## amcananey

Ben,
   
  I would just go for the 12 dB version. Even the 12 dB doesn't make as much of a difference as you would think. I would expect the 6 dB version to be fairly useless, to be honest...
   
  Best regards,
  Adam


----------



## ben_r_

Quote: 





amcananey said:


> Ben,
> 
> I would just go for the 12 dB version. Even the 12 dB doesn't make as much of a difference as you would think. I would expect the 6 dB version to be fairly useless, to be honest...
> 
> ...


 

 Good advice, Ill start with the 12dB.


----------



## swmtnbiker

Quote: 





amcananey said:


> I just bought a pair of these. They work perfectly. And it may just be my imagination, or it may be the fact that I also installed a new TDK volume pot and the attenuators let me set it to work within its sweet spot, but I actually find that my system sounds better now. The treble isn't quite as hot, making the amp very relaxing to listen to. In any case, the Harrison attenuators are highly recommended.


 
   
  Mine came yesterday and they're working great for me as well. The usable range on my volume pot is now 0 to about 10:00. MUCH more reasonable!


----------



## swmtnbiker

Quote: 





ben_r_ said:


> You guys are using those coming out of what source again?


 
   
  Channels Islands Audio VDA-1 outputting 2.4V.


----------



## Jmstrmbn

These stories make me kinda glad I am preamping my crack with the Nuforce HDP.  It may not be the most straight forward signal path but I have a lot of leeway on the volume pot.


----------



## ben_r_

For anyone interested Vacuum Tubes.net has Tung-Sol/Chatham 5998 tubes in stock! $92 shipped for one. LINK
   
  And Parts ConneXion.com has Obbligato PSU and Mundorf MKP 100uf Film Caps both in stock for $39 or $48 each plus shipping.


----------



## Pudu

I don't know if it has been mentioned here yet, but there is a bit of a group buy of Chatham 2399 tubes (which the same tube as Tungsol 5998) going on in the Woo thread. 



ultrainferno said:


> I managed to get twenty 2399 Chatham/Tung sol tubes (equals 5998 Tung Sol). 4 are already spoken for so 16 are left, if you're interested pm me for prices and info.
> First come, first serve. I have a USA distributor as well to save on shipping costs.




Last I heard there were still 5 left. It's a really good price on an increasingly difficult tube to find. Shoot Ultrainferno a pm if you are interested.

Apologies if this has already been brought to attention.


----------



## eantala

HI guys, I'm really enjoying the hell out of the Crack /w Speedball. Using 5998 power tube and mullard cv4003 input (the only 12au7 I own) its pretty nice.
   
  I've searched and searched but couldn't find anything conclusive.  
  Due to having a Jeff Korneff integrated I have many 6sn7 lying around.
  I heard something about 6sn7 using more current than the 12au7, but some said it wasn't a problem
  So my question is can I simply ( with no mods to the amp), just drop in a 12au7 to 6sn7 socket converter and begin to use 6sn7's?
  or is this not advisable??


----------



## ben_r_

eantala said:


> HI guys, I'm really enjoying the hell out of the Crack /w Speedball. Using 5998 power tube and mullard cv4003 input (the only 12au7 I own) its pretty nice.
> 
> I've searched and searched but couldn't find anything conclusive.
> Due to having a Jeff Korneff integrated I have many 6sn7 lying around.
> ...




Have you tried contacting Bottlehead about this?


----------



## j123my

With the appropriate adapter, yes you can roll in 6SN7. I have tried it myself.


----------



## TheKillerPiglet

Quote: 





eantala said:


> So my question is can I simply ( with no mods to the amp), just drop in a 12au7 to 6sn7 socket converter and begin to use 6sn7's?
> or is this not advisable??


 
   
  Not juts advisable, I recommend this. Love the 6sn7's here.
   
  KP


----------



## eantala

Quote: 





j123my said:


> With the appropriate adapter, yes you can roll in 6SN7. I have tried it myself.


 
  I just ordered an adapter, good stuff , let the rolling begin..      thanks again!


----------



## eantala

Quote: 





thekillerpiglet said:


> Not juts advisable, I recommend this. Love the 6sn7's here.
> 
> KP


 
  thanks again I been looking on ebay all day at 12au7 tubes, but luckily didnt buy any, 
  I want to see how things go with the 6sn7's as I already have a bunch of them.


----------



## ben_r_

Quote: 





eantala said:


> I just ordered an adapter, good stuff , let the rolling begin..      thanks again!


 

 What adapter did you order?


----------



## j123my

There are several adapters of different brand/seller you can get from ebay. Unfortunately those ships from China, so be patient.. 
	

	
	
		
		

		
			




   
  To be honest, I don't quite like my crack paired with 6sn7's as much as I like it with Telefunken 12au7. Also for all the 6sn7's I have tried (mostly Tung Sols and RCAs), I always have a noise problem that increases with the volume pot, peaks at around 1/2 way through, and gone if you crank the pot further up. This happens to all my 6sn7's and none with other 12au7 tubes, so I am guessing that it might be due to the fact the crack is not designed to be paired with 6sn7... Anyone has the same issue?
   
  Paired with a Telefunken 12au7 and a 5998, the crack is simply heavenly. Will find out soon how much better it gets with upgraded components.


----------



## Doc B.

I've always been in what seems to be a very small minority when it comes to the 12AU7 vs. 6SN7 thing too, finding the 12AU7 to be a little more articulate and the 6SN7 a little too tubey for my taste. Most everyone I know prefers the 6SN7, and it looks to be a more linear tube overall in the published spec. My hunch about the rising and dropping noise floor is that it may be the additional contacts and signal path length created by using the adapter that are causing the noise, rather than the 6SN7 itself.


----------



## TheKillerPiglet

Interesting. My "tubiest" setup on the Crack is 12bh7 (any brand) + RCA 6AS7G, the "least" Sylvania chrome top 6sn7 + GE 5 Star 6080.
   
  KP


----------



## eantala

great feedback , I'd stick to 12au7's but I only have one (mullard cv3004), while having so many nice 6sn7 lying around unused.  
   
  I figure $14 for an adapter might as well at least try out the 6sn7s, hopefully I get good results like killerpiglet don't get any noise floor issues.


----------



## larcenasb

Hello all,
   
*help needed*: On bypassing the 220uF 250V power cap in the Crack, I want to use the Auricap XO 2.2uF. Is the 200V vers. not enough? Is the 400V vers. too much? Can someone please break this voltage matching and allowances down for me, I can't find anything conclusive online and I'm kind of nervous from my ignorance about it. And ultimately, which voltage should I use? Thanks so much. Happy listening


----------



## BmWr75

Quote: 





larcenasb said:


> Hello all,
> 
> *help needed*: On bypassing the 220uF 250V power cap in the Crack, I want to use the Auricap XO 2.2uF. Is the 200V vers. not enough? Is the 400V vers. too much? Can someone please break this voltage matching and allowances down for me, I can't find anything conclusive online and I'm kind of nervous from my ignorance about it. And ultimately, which voltage should I use? Thanks so much. Happy listening


 
   
  General rule is higher voltage rating will always be OK, lower voltage rating can some times be a problem.


----------



## larcenasb

Thanks so much for the response -- I'll go with the 400V then, cheers


----------



## Zynec

Curious how the Russian Military 6SN7 (ie 1578) works with the Crack?  Anybody know?  Since I have some NOS 1578's here that have less than 100hrs on them, I really need to find some way to use them!


----------



## skeptic

There was a discussion on the BH boards a while back about how 6sn7's might not be an ideal match for the crack due to PS circuit.  My recollection is that the crack delivers ac to the tubes' heaters, whereas 6sn7's should ideally be getting dc - to say nothing of the possible noise introduced by the adapters.
   
  At the time, this was enough to send me hunting 12bh7's instead - my favorite of which is a 1959 Tung Sol.  But I confess I am still curious to hear how a good 6sn7 sounds.


----------



## Doc B.

6SN7s are fine with AC heaters.


----------



## EraserXIV

I'm getting a lot of noise through my Crack when I attach a USB DAC to it. I hear the noise regardless of whether music is playing. Pretty sure it's the USB because when I unplug the cable from my computer it completely disappears. I don't get any noise from the USB DAC when I use my M-stage as an amp though.
   
When I use an E10 as an SPDIF interface and output coax to my DAC, it's dead quiet. When I input coax (SPDIF) from my Oppo 980H CD player it's dead quiet as well. However, when I use the E10 as the DAC and output it's analog line-out directly to the Crack, I hear the noise again.
   
Do I just have a noisy USB socket on my computer, or is it the cable, or is the DAC not filtering out the noise?
Or could it be that the braid on the wires from the RCA inputs to the pot in the Crack wasn't done well enough?
Any ideas on why I'm hearing so much noise?


----------



## Armaegis

Do you get the noise when plugging in an mp3 player? What about running the laptop from battery?
   
  Is the noise like a low hum, or more like static/white noise?
   
  My initial guesses would be noisy usb socket and/or power supply, or a ground loop.


----------



## EraserXIV

It's like static/white noise that seems random but does have a slight pattern to it (if that makes any sense). It seems like it has a cyclic pattern where it gets louder and softer at intervals without me touching anything on the amp, DAC, or computer. I haven't tried an mp3 player or unplugging the laptop, will definitely try that when I get home later tonight.


----------



## Beefy

Sounds like switching PSU noise polluting the ground. I had the same thing when trying to listen to my Crack on my old laptop.


----------



## EraserXIV

So that's an issue with the power supply to the laptop? I guess this can be tested easily by unplugging my laptop, will do that later today.
Just curious, why does this noise not transfer when I use an SPDIF interface in the middle of the chain?
   
  Also, if it is the switching power supply from the laptop, are there any ways to fix the noise? I don't really mind using the SPDIF interface, but I like keeping the chain as simple as possible and if I can avoid it, the better. Will certain DACs filter the noise better than others? How come the M-stage didn't pick up the noise?


----------



## Armaegis

The spdif is essentially isolated from dirty power noise.
   
  It could be the Matrix has better power or input filtering, or is configured in a way that happens to reject that particular sort of noise. 
   
  To "fix" the laptop... well, you could get a better power supply, or just run off battery (maybe a bigger battery, or external battery pack). You can also try a ground loop isolator. They're cheap... like $10 from radio shack. It looks like a regular RCA interconnect with a block in the middle (typically about the size/shape of a D cell battery).


----------



## EraserXIV

So I think the noise I was hearing is a combination of a couple things. I switched power supplies on my laptop to one with a 2 prong plug and it reduced the noise a lot. At first, I thought it completely eliminated the noise, but when I turned the pot up on the Crack past 12 I started hearing it again (albiet only slightly). Before I switched supplies I was able to hear the noise with the pot completely turned down to 6 (and it was much louder than the new supply past 12).
   
  With the pot turned up to 12 using the new power supply, unplugging the power supply altogether slightly reduced the noise. The noise doesn't completely disappear unless I unplug the USB from my laptop. I'm thinking it's a combination of noise from the power supply (ground loop?) and a noisy USB port. I do most of my listening between 8-10 so it's not really an issue for me I guess. I only barely hear it at 12. I might still toy with the idea of the SPDIF interface though as it completely eliminates the noise.
   
  Any ideas on what a powered USB hub would do?
   
   
   
  Edit: this video gave me the idea to switch to a 2 prong plug power supply: http://www.youtube.com/watch?v=jSA2F1AwboU


----------



## Armaegis

The powered usb hub *might* help, but no guarantee. You're better off with the unearthed power supply or a signal isolator.


----------



## Jmstrmbn

> I might still toy with the idea of the SPDIF interface though as it completely eliminates the noise.


 
   
   
  Just curious, is he describing jitter or is it simply dirty power from the USB port?


----------



## EraserXIV

I'm pretty sure it's dirty power from the USB port


----------



## Armaegis

There's no way any jitter would cause noise that bad. That'd be an utter failure of the device right there.


----------



## Jmstrmbn

Gotcha, thanks for the clarification.


----------



## silverhead

Hello everyone,  I'm new here, and new to 'head phone hi-fi.'
   
  Saturday I 'won' someone's Bottlehead Crack project on ebay.  It's in transit at the moment.   I have in my possession Sennheiser HD 650 headphones as well as Beyerdynamic DT990 Pro (250 ohm version.)
   
  My random question is that I just noticed the transformer in the crack is hanging low.  The person who built it mounted it underneath the aluminum plate.  Is this an issue?  All of the photos I've seen have it sitting on top of the plate.   I'm planning on cleaning it up when I get it but I wanted to know if this is definitely incorrect.  
   
  Here's a photo.  I don't know how to embed photos on this message board yet since I'm new and it doesn't appear to take BB code or HTML.
   
  http://farm9.staticflickr.com/8378/8533534049_26365b3014_c.jpg
   
  Here's the underneath shot:
   
  http://farm9.staticflickr.com/8377/8534642286_26dd8b5673_c.jpg
   
   
  Thanks for any info!


----------



## captouch

Quote: 





silverhead said:


> Hello everyone,  I'm new here, and new to 'head phone hi-fi.'
> 
> Saturday I 'won' someone's Bottlehead Crack project on ebay.  It's in transit at the moment.   I have in my possession Sennheiser HD 650 headphones as well as Beyerdynamic DT990 Pro (250 ohm version.)
> 
> ...


 
  Great price - I saw that for sale on Audiokarma.  Already have one otherwise I would have bought it!
   
  I think you're fine, but I'm sure Doc will be here to comment.


----------



## FraGGleR

Quote: 





silverhead said:


> Hello everyone,  I'm new here, and new to 'head phone hi-fi.'
> 
> Saturday I 'won' someone's Bottlehead Crack project on ebay.  It's in transit at the moment.   I have in my possession Sennheiser HD 650 headphones as well as Beyerdynamic DT990 Pro (250 ohm version.)
> 
> ...


 
  Lol, so you are who outbid me 
   
  I wanted to build one myself anyways, just tried to see if I could snag it for cheap.


----------



## liamstrain

I don't think there would be any issues. Looks interesting that way.


----------



## Armaegis

The only thing I can think of is that there might be a bit of hum by putting the transformer underneath the plate, but I don't know for certain.


----------



## liamstrain

Quote: 





armaegis said:


> The only thing I can think of is that there might be a bit of hum by putting the transformer underneath the plate, but I don't know for certain.


 
   
  I was thinking having it further away from the power tube, might actually reduce hum. :/
   
  Hopefully Doc can chime in.


----------



## Armaegis

I dunno... further away from the tube, but closer to all the other guts.


----------



## FraGGleR

Anyone know off hand what gauge wire comes with the kit?  I'm assuming it is solid core.


----------



## ben_r_

Quote: 





fraggler said:


> Anyone know off hand what gauge wire comes with the kit?  I'm assuming it is solid core.


 

 Solid core 20AWG.


----------



## FraGGleR

Quote: 





ben_r_ said:


> Solid core 20AWG.


 
  Thanks!


----------



## dave1109

Quote: 





silverhead said:


> Hello everyone,  I'm new here, and new to 'head phone hi-fi.'
> 
> Saturday I 'won' someone's Bottlehead Crack project on ebay.  It's in transit at the moment.   I have in my possession Sennheiser HD 650 headphones as well as Beyerdynamic DT990 Pro (250 ohm version.)
> 
> ...


 
   
  Quote: 





fraggler said:


> Lol, so you are who outbid me
> 
> I wanted to build one myself anyways, just tried to see if I could snag it for cheap.


 

 congrats, bid on that myself, also wanted one on the cheap just to try with my hd650's


----------



## imackler

Quote: 





dave1109 said:


> congrats, bid on that myself, also wanted one on the cheap just to try with my hd650's


 
   
  Seeing how imperfect that one was on ebay and how it went for around 200, it makes me more willing to try one! I could always sell my first imperfect, but working, attempt. 
   
  Does anyone know when the last time there was a group buy on headfi for the Crack? 
   
  Are there any pre-fabricated OTL tube amps that come close to the Crack in the price range? I'm scared of DIY...though I'm getting tempted!


----------



## FraGGleR

Quote: 





imackler said:


> Seeing how ugly that one was on ebay and how it went for nearly 200, it makes me more willing to try one! I could always sell my first ugly attempt.
> 
> Does anyone know when the last time there was a group buy on headfi for the Crack?
> 
> Are there any pre-fabricated OTL tube amps that come close to the Crack in the price range? I'm scared of DIY...though I'm getting tempted!


 
   
  I was hoping that since it was so ugly, I'd get it closer to $125-150.  I was wrong.
   
  From what I understand, this kit is as paint by numbers as you can get.  Maybe not as simple as stuffing a PCB, but a lot of people have done this as their first DIY project and completed it an evening or two.
   
  No idea about the group buy, but I regret not going in with another Headfier on Black Friday.  Not only was there a discount, but by going in with another person, there was a discount for buying more than one.  
   
  Reading a bit about this kit on the forum and speaking to several experienced Headfiers, there isn't really anything in its price range that can compare quality wise.  Someone who's opinion I very much respect has tried his HD800 with a number of amps, including a couple Woo Audio amps that approach $2000 and he still says the Crack with Speedball is the better sounding match.


----------



## Armaegis

The Crack comes with an excellent manual. I would say it's doable in two nights, but don't rush it. I've done it in a single day before, but that wasn't my first time and I spent a separate day prepping and pre-cutting/stripping all the wires beforehand. 
   
  Actually, I'd highly recommend spending time to prep all the wires beforehand anyways, and maybe tinning some of the strips if you've got a lousy iron. For first time builders, also take a careful look at the placement of those capacitors near the transformer. It can be a bugger getting them into place and finding room to sneak the iron in.


----------



## captouch

Quote: 





fraggler said:


> I was hoping that since it was so ugly, I'd get it closer to $125-150.  I was wrong.
> 
> From what I understand, this kit is as paint by numbers as you can get.  Maybe not as simple as stuffing a PCB, but a lot of people have done this as their first DIY project and completed it an evening or two.


 
   
  They made a very weird choice to not glue the base and bracket/brace it (badly w/gaps) instead.  Easy fix to remove the brackets, wood glue it to look nice, optionally stain and poly it.  It'd be harder to finish the top plate since it's built out, but the aluminum with nicely stained bottom would look nice.
   
  Build wasn't the cleanest, but if it didn't hum, no big deal since the innards are hidden.  And that transformer placement was unconventional, but again, as long as it doesn't cause problems or degrade SQ, it's actually lower profile.  
   
  It is a pretty straightforward kit to build.  I did it with little previous soldering experience and my only issue as a hum it took me awhile to track down (cold solder joint).  There are some points in the assembly where you have to get into tighter spaces (soldering wires and LEDs near the tube sockets) that require steadier hands and decent hand/eye coordination, but I consider myself pretty much a hacker and I did it without issues.
   
  I'd do it in multiple evenings as well.  It is enjoyable if you don't rush through it, and spending time prepping (measuring and stripping wires in advance) can minimize interruptions.  I found it a little annoying to measure/strip each wire as I needed it.  Would have been nicer to have the all ready to go in case you're feeling in a "soldering groove".


----------



## silverhead

My plan when I saw it was to bid what the cost of a new one is given the wait to get a new one + the cost of buying one pre-assembled.  I REALLY wanted to build my own, but I can always start messing with this one. 
   
  I'm into Haywood Wakefield furniture, so I plan on trying to build a new case based on this style of bed, out of birch.
   
  http://p2.la-img.com/919/16340/5516892_1_l.jpg
   
  I figured with people paying over 400 dollars for other peoples' projects that the price I paid was safe.  I'll be able to get it up and running, but this is my first foray into this sort of thing.  I know how to solder and I have several other useless hobbies to help me extrapolate on this one 
   
  Is the assembly manual available for download anywhere?  I'd love to reverse engineer it a bit.  Otherwise I'll try to read through this thread to learn about the common upgrades to capacitors, tube sockets, etc...


----------



## FraGGleR

Quote: 





silverhead said:


> My plan when I saw it was to bid what the cost of a new one is given the wait to get a new one + the cost of buying one pre-assembled.  I REALLY wanted to build my own, but I can always start messing with this one.
> 
> I'm into Haywood Wakefield furniture, so I plan on trying to build a new case based on this style of bed, out of birch.
> 
> ...


 
  You can probably get the manual if you ask on the Bottlehead forum.
   
  I decided to not raise my bid because building it from scratch would be easier than a complete rebuild.


----------



## silverhead

I'm going to listen to it first.  If it's dead quiet, I might just leave it alone and let it sit there looking like a  Homer Simpson spice rack.   I'm pretty stoked to get it.  The simplicity of the design is what I appreciate most.   It keeps it dumbed down to that 1940's era electronics theory that I can digest mentally.  I'll sign up over on the Bottlehead forums now.


----------



## Doc B.

We're gearing up for AXPONA at the moment, but I have a few thoughts to offer -

We aren't able to offer assembled kits anymore. My techs are hired for R&D and have been so busy that there is little time available to do assembly. The assembly does take some time because the kits are hand wired, which we feel is important for sound quality. It's also a fun process. The Crack kits are built primarily by first timers, and there are many hundreds of them in the field. I don't think people need to worry about whether or not they can build one. We have sold a few million dollars worth of Bottlehead kits in the past 19 years. If they were hard to get working I think I would be saying we sold a few hundred dollars worth - and maybe still making pastries for a living.

As to buying used, from my perspective it's a crap shoot. That may be because those who buy a good used kit are happy with it and I don't hear about it. But when one does buy a bad one, it has often been "improved" and then the guy who originally built it dumps it on ebay for someone else to sort out the problems he introduced with his "improvements". You can find some of them coming to the Bottlehead forum for help, because as near as I can tell the seller seldom offers to help.

My advice in most cases is build it yourself, and build it stock first. It's more rewarding to build it from the start and not as much fun to sort out some other newb's mistake. The process is also not an instantaneous one, that is to say that buying a kit and reading something on the interweb does not always qualify you to dive in, make changes and know for sure the change was a positive one . You have to have a baseline to start with, the stock kit. Get it running the way it was designed, then move on to learning about modifications. 

I would also suggest not getting so hung up on cosmetics that you need change the basic layout. There may or may not be issues of noise, cooling etc., that arise and we may not have tried doing it the different way you want to do it. 

Don't take this the wrong way, I'm totally for finding the killer deal myself. And I started Bottlehead out of a love for building and modifying gear. So much so that I like to see others go about the process in a way that lets their skill and knowledge grow without getting too frustrated in the process.


----------



## FraGGleR

Quote: 





doc b. said:


> We're gearing up for AXPONA at the moment, but I have a few thoughts to offer -
> 
> We aren't able to offer assembled kits anymore. My techs are hired for R&D and have been so busy that there is little time available to do assembly. The assembly does take some time because the kits are hand wired, which we feel is important for sound quality. It's also a fun process. The Crack kits are built primarily by first timers, and there are many hundreds of them in the field. I don't think people need to worry about whether or not they can build one. We have sold a few million dollars worth of Bottlehead kits in the past 19 years. If they were hard to get working I think I would be saying we sold a few hundred dollars worth - and maybe still making pastries for a living.
> 
> ...


 
  Thanks for chiming in Doc.  I hope that both the super headphone amp and DAC that have been talked about on the Bottlehead forums come to fruition.  As happy as I am with the S.E.X. that I bought second hand, I don't think I can resist ordering a Crack to do myself.


----------



## silverhead

Oh, I understand the risks of ebay and other peoples' projects =)   From what I could see the only 'modification' was that the transformer was 'low rider.'  
   
  I'm the sort of person that'll take the whole thing apart a time or two by the time I'm done probably.  This just happens to be my first amplifier (as opposed to my first camera, car, motorcycle, etc...)    I'm really excited to get it because I've read nothing but good things about the design and simplicity. 
   
  Who knows, maybe the guy is sending along the paperwork.  I doubt it though...  eBay stuff tends to come wrapped in Pampers diaper boxes smelling like cigarettes.  
   
  I'm in that beginning phase of the hobby trying to sort out hype and religious experiences from things I can actually hear.   My hearing's not so great.  I can't hear any sounds above 15khz.   I'm currently listening to my headphones through a restored Marantz 2275.   The bottlehead is going to be fun for me to change tubes in to see how it affects the sound.    If I end up really liking messing with it I'll probably be after the Stereomour kit to use with my home speakers and turntable.


----------



## amcananey

Just to briefly chime in, the Crack manual is excellent. The instructions are super-detailed and accompanied by color pictures that are fairly high resolution. As long as you take your time, don't rush and take the instructions literally, you won't have any problem. And even if you do, the Bottlehead Team (and the rest of the Bottlehead community) is *very* fast to respond to questions on the Bottlehead forum with lots of very helpful advice.
   
  I have zero qualms recommending the Crack to someone with no previous amp-building experience. Building it was fun and the instructions were so clear and methodical, that it was actually pretty relaxing.
   
  I do have one piece of advice: if you want to upgrade your volume pot (to be clear, I do *not* consider this necessary or even really cost-effective), then I would do it when you first built the kit, since doing it later is a pain. Also, as someone indicated above, fitting everything into the hole on Terminal 14U (if I'm remembering this correctly) can be a real pain, so alot some time to figuring out how you're going to do that, and don't solder anything to that terminal until instructed to do so.
   
  Best regards,
  Adam


----------



## Doc B.

@silverhead, yeah I've bought a bunch of stuff from that pampers and cig smoke guy myself. Once I received a microphone in the mail, that had been taped onto a single piece of cardboard. The guy had a fit when I suggested he might want to spend a little money on packing material. I guess they got a different way of packing in some states. Maybe he needed the rest of the cardboard box to sleep in that night.

@adam, I am hesitant to suggest anyone who has never built a kit before change up something like a volume pot during the initial construction. Different attenuators might connect to the circuit differently than the stock pot and that could be pretty confusing for some noobs. Recently someone went into a series of mods on a Bottlehead kit and bought an "upgrade" pot from someone else that came with the wrong instructions. Mondo frustration vent on the Bottlehead Forum (I guess maybe the guys who sold the pot didn't have a tech forum for him to vent on). If someone feels confident about it, go for it. But if one feels they are in new territory I suggest sticking with the basic program first and then doing mods.


----------



## silverhead

My ebay Crack showed up today.  As expected, it was wrapped in newspaper and shipped in a used box.  No power cord and no paperwork of any kind.  
   
  Here's a few images:
   

   
  bigger: http://farm9.staticflickr.com/8530/8540582081_ff29638a39_h.jpg
   

   
  bigger: http://farm9.staticflickr.com/8380/8540581821_468ed70814_h.jpg
   

   
  bigger: http://farm9.staticflickr.com/8234/8541683888_b8f7a4bfe9_h.jpg
   
   
  I looked it over carefully and there's a few solder joints I'm not that fond of, but they're all seemingly 'attached.'   I used come Caig Deoxit to clean the tube, RCA, and power sockets.   I cleaned the tubes so the big one wouldn't stink when it heated up.   So I powered it up and it came up just fine.    I'm supplying a signal from my iphone using a Pure brand DAC.   The amp is dead silent with the volume knob cranked when no song is playing.   To power my 250ohm headphones I've got the knob set to about 5-7 on a scale of 0-10.  7 is probably loud enough to cause me hearing damage over time.    The amp sounds really good.  Stereo works fine and both bass and treble are fine.   I'll probably be leaving it alone for the time being because it sounds how I want it to.
   
  I've had it powered up for about 6 hours now.  The aluminum plate is quite warm, about to the point you wouldn't want to hold your finger onto it all that long, but it didn't burn me after holding my finger on it for 30 seconds.   I'll have to read about what temperature the 6080 tube should be running and how hot the transformer should get, etc.. I have an IR thermometer to check those values. 
   
  All in all, I'm very happy.  The gamble on eBay appears to have paid off.   I am going to get up some time in the morning and get some supplies to square up the box and stain it.  I'm also going to sand off those gluey fingerprints on it.


----------



## captouch

Congrats Silverhead, glad to hear it worked out well.
   
  If those gluey fingerprints don't sand off well, just make that the back side.  
   
  Post pics when you're done.


----------



## liamstrain

The crack does run warm. Your description sounds pretty in line with how mine runs, fwiw. Enjoy it!


----------



## Armaegis

The transformer shouldn't get that hot, but the tube can burn you (pretty sure I scorched a fingerprint into it once). The plate vent area also gets quite hot if you don't have a speedball in there.


----------



## silverhead

I'm not a woodworker.  I tried using a router (not mounted in a table) and a crappy miter saw today to make a case out of oak.  That worked in terms of making the right dimension pieces, but my saw doesn't cut 45 degrees flat across boards well enough to mate up the corners.   So I decided to take apart the factory box and shore it up using wood glue and metal angle brackets internally.  That worked out OK.  The corners didn't meet up perfectly because the last guy had some dry wood glue in there.  But I think it looks fab-tabulous anyway.   I sanded it down to 400 grit and smoothed off all of the corners and edges just a tad.   I used some Danish wood oil (walnut color) to finish it off when I was done sanding.    
   
  The front panel looks cool because there's a knot in the wood, so it sort of looks like an eye.   It catches the light the same way a tiger eye agate does.    Here's some photos now that it's dry.
   

   
   
  Bigger: http://farm9.staticflickr.com/8237/8543872572_d9adfe5c2b_h.jpg
   

   
  Bigger: http://farm9.staticflickr.com/8511/8542771581_bbe0a83fe6_h.jpg
   

   
  Bigger: http://farm9.staticflickr.com/8094/8542771027_4afa2e12bf_h.jpg
   

   
  Bigger: http://farm9.staticflickr.com/8089/8543871982_24a6778a4a_h.jpg


----------



## FraGGleR

Quote: 





silverhead said:


> I'm not a woodworker.  I tried using a router (not mounted in a table) and a crappy miter saw today to make a case out of oak.  That worked in terms of making the right dimension pieces, but my saw doesn't cut 45 degrees flat across boards well enough to mate up the corners.   So I decided to take apart the factory box and shore it up using wood glue and metal angle brackets internally.  That worked out OK.  The corners didn't meet up perfectly because the last guy had some dry wood glue in there.  But I think it looks fab-tabulous anyway.   I sanded it down to 400 grit and smoothed off all of the corners and edges just a tad.   I used some Danish wood oil (walnut color) to finish it off when I was done sanding.
> 
> The front panel looks cool because there's a knot in the wood, so it sort of looks like an eye.   It catches the light the same way a tiger eye agate does.    Here's some photos now that it's dry.
> 
> ...


 
  Fantastic job!  Looks MUCH better with some proper attention.


----------



## swmtnbiker

I bought a pre-built Crack + Speedball from a fellow Head-fier a few weeks ago and couldn't be happier with the amp. Not only does it sound absolutely *phenomenal* with my HD 650, the build is a thing of beauty. It's a very, very cleanly done job with braided wiring pre-cut to the proper length and practically flawless soldering. The Crack's wood housing however was received in its raw state, so this past week I decided to complete it. Ordered a Bottlehead badge from Doc to top it all off and settled on a distressed satin black finish with a few "antique " dings and dents here and there. Thought I'd post a few pics. Here ya go...


----------



## swmtnbiker

Quote: 





silverhead said:


> I'm not a woodworker.  I tried using a router (not mounted in a table) and a crappy miter saw today to make a case out of oak.  That worked in terms of making the right dimension pieces, but my saw doesn't cut 45 degrees flat across boards well enough to mate up the corners.   So I decided to take apart the factory box and shore it up using wood glue and metal angle brackets internally.  That worked out OK.  The corners didn't meet up perfectly because the last guy had some dry wood glue in there.  But I think it looks fab-tabulous anyway.   I sanded it down to 400 grit and smoothed off all of the corners and edges just a tad.   I used some Danish wood oil (walnut color) to finish it off when I was done sanding.
> 
> The front panel looks cool because there's a knot in the wood, so it sort of looks like an eye.   It catches the light the same way a tiger eye agate does.    Here's some photos now that it's dry.


 
   
  Very nicely done!!


----------



## FraGGleR

Stop it guys!  You are really making me want to order a kit.
   
  And possibly one of these: http://www.blumensteinaudio.bigcartel.com/product/wooden-chassis-for-bottlehead-tube-amplifiers


----------



## Draygonn

silverhead said:


> Spoiler


Stunning



swmtnbiker said:


> Spoiler


I love the worn look.


----------



## TheKillerPiglet

Good stuff, guys.
   
  KP


----------



## silverhead

The pre-fab case might seem spendy at 95 bucks, but the tools at Home Depot to make the same thing will run you several hundred dollars    I was contemplating it today, but I haven't lost all of my mind yet.


----------



## FraGGleR

Quote: 





silverhead said:


> The pre-fab case might seem spendy at 95 bucks, but the tools at Home Depot to make the same thing will run you several hundred dollars    I was contemplating it today, but I haven't lost all of my mind yet.


 
  As someone who has spent more on tools and experiments trying to come up with a way to get around spending money on front panels from Front Panel Express on another project, I am finally coming to my senses.  I adore DIY and will one day have a workshop that can match my passion, but right now, I need to save myself time, money, and frustration and just pay for pretty things.


----------



## j123my

Quote: 





silverhead said:


> Spoiler: Warning%3A%20Spoiler!


 
  Quote: 





swmtnbiker said:


> Spoiler: Warning%3A%20Spoiler!


 
  Damn.. I need to learn how to finish wood..


----------



## swmtnbiker

Quote: 





j123my said:


> Damn.. I need to learn how to finish wood..


 
   
  Uh huh-huh-huh. You said wood...


----------



## elwappo99

Great work and since no one else mentioned it, the pictures are also really good! Nice job! 
   
  Also, I'm first in line to buy them


----------



## Armaegis

Quote: 





fraggler said:


> As someone who has spent more on tools and experiments trying to come up with a way to get around spending money on front panels from Front Panel Express on another project, I am finally coming to my senses.  I adore DIY and will one day have a workshop that can match my passion, but right now, I need to save myself time, money, and frustration and just pay for pretty things.


 
   
  Every time I'm at the hardware store and pass by the sales for their tools, I keep reaching out for one then pulling my hand back. Same thing when I'm at the electronics shop and start wondering if I should pick up a kit to start etching my own boards. I *could* do it, but then I'd have an excuse to spend even more money and take up even more space that I don't have. All to make something that isn't quite as good and probably doesn't look as nice as one that I'd buy... sigh. DIY is a trap sometimes.


----------



## lextek

Gotta love Crack!


----------



## FraGGleR

Quote: 





armaegis said:


> ... *DIY is a trap sometimes. *


 
  Amen to that.


----------



## amcananey

Quote: 





doc b. said:


> @adam, I am hesitant to suggest anyone who has never built a kit before change up something like a volume pot during the initial construction. Different attenuators might connect to the circuit differently than the stock pot and that could be pretty confusing for some noobs. Recently someone went into a series of mods on a Bottlehead kit and bought an "upgrade" pot from someone else that came with the wrong instructions. Mondo frustration vent on the Bottlehead Forum (I guess maybe the guys who sold the pot didn't have a tech forum for him to vent on). If someone feels confident about it, go for it. But if one feels they are in new territory I suggest sticking with the basic program first and then doing mods.


 
   
  Doc,
   
  Ermmm....I was that guy. 
	

	
	
		
		

		
		
	


	




  FWIW, I never blamed Bottlehead for that problem - it was clearly the seller's fault and Paul quickly straightened me out by indicating that I should just wire it the same way as the stock pot. I was *very* grateful for his quick and helpful response. Paul also noted that "It is incredibly rare that a volume pot differs from the stock pot in the Crack in terms of connections." For me at least, it would have been 10x easier if I had just dropped that pot in when building the kit, since there are a lot of connections on the volume pot, and redoing them afterwards was a bit challenging to me, but I get why it makes sense for people to build the kit in stock form before experimenting and "upgrading" (FWIW, other than the Speedball, I wouldn't say any of my Crack upgrades were necessary or cost-effective. They were generally fun to do, and trying them gave me peace of mind that I wasn't missing out on anything, but to be clear: the stock Crack does not need to be upgraded in any way to sound phenomenal. Other than the Speedball, mods and upgrades are more about fun and personalization than about objective improvements in sound quality.
   
  Best regards,
  Adam


----------



## stephenbou

I have an order placed, and I've started thinking about how I'd like to finish the wood. My plan is to polish the aluminum plate and treat the wood to look like this
   

   
  adapting from these step-by-step instructions for finishing a guitar body.
   
  I feel much more comfortable with the electrical assembly than the woodworking.


----------



## elwappo99

In blue? That would look pretty clean with the aluminum top. Hope you report back with pics! 
   
   
  Quote: 





stephenbou said:


> I have an order placed, and I've started thinking about how I'd like to finish the wood. My plan is to polish the aluminum plate and treat the wood to look like this
> 
> 
> 
> ...


----------



## Armaegis

I tried polishing the top plate once... gave up shortly thereafter and went with paint instead 
	

	
	
		
		

		
			




   
  Although now that I think of it, a mirror finish paint might work...


----------



## elwappo99

Has anyone ever tried putting an adapter on the headphone out to make this work better with a lower impedance headphone (like the D7000)?  Something like a 70Ohm resistor ?


----------



## Armaegis

I've tried it with both ~70 ohm and ~250 ohm resistors. Both seemed to work just fine.


----------



## Beefy

Quote: 





elwappo99 said:


> Has anyone ever tried putting an adapter on the headphone out to make this work better with a lower impedance headphone (like the D7000)?  Something like a 70Ohm resistor ?


 
   
  Just what are you expecting that resistor to do?
   
  The problem with an OTL for low impedance headphones is the small size of the output cap causing bass cutoff, and poor damping due to the high output impedance. Adding a resistor will marginally improve the first issue, while simultaneously making the second worse.


----------



## Doc B.

One significant issue with a series resistor is that the added resistor creates a voltage divider with the headphone impedance and thus the headphone sees much less signal voltage, i.e., it won't play as loud. If the cans are very sensitive it might work OK. This is the kind of experiment that is simple and inexpensive to try - and share your results! You might try about 120 ohms as a starting point with sensitive 32 ohm cans. Resistor should be conservatively rated for about a watt of power dissipation, half watt is marginal but probably OK.


----------



## stephenbou

Quote: 





armaegis said:


> I tried polishing the top plate once... gave up shortly thereafter and went with paint instead
> 
> 
> 
> ...


 

 What did you use for polish? I'm going to give Mothers Mag & Aluminum Polish a try. I've never used it; hope it works.


----------



## ben_r_

Quote: 





stephenbou said:


> What did you use for polish? I'm going to give Mothers Mag & Aluminum Polish a try. I've never used it; hope it works.


 

 If youre going for a mirror finish I think youre gonna need something a lot more abrasive than that.


----------



## Armaegis

The one time I tried for a mirror finish, I started with some wet sanding with sandpaper from 400 to 1200, which took more time than I care to admit. I then started with a dremel polishing kit, did one pass across the surface... and gave up. If I had a bigger polishing attachment for a drill, maybe, but that's hours of polishing in total. It might be more time/cost/sanity effective to go with a reflective paint, several layers of clear coat, and polish the top coat.


----------



## ben_r_

Or get a cheap random orbital sander and use it as a buffer too: LINK


----------



## elwappo99

Quote: 





doc b. said:


> One significant issue with a series resistor is that the added resistor creates a voltage divider with the headphone impedance and thus the headphone sees much less signal voltage, i.e., it won't play as loud. If the cans are very sensitive it might work OK. This is the kind of experiment that is simple and inexpensive to try - and share your results! You might try about 120 ohms as a starting point with sensitive 32 ohm cans. Resistor should be conservatively rated for about a watt of power dissipation, half watt is marginal but probably OK.


 
   
  Quote: 





beefy said:


> Just what are you expecting that resistor to do?
> 
> The problem with an OTL for low impedance headphones is the small size of the output cap causing bass cutoff, and poor damping due to the high output impedance. Adding a resistor will marginally improve the first issue, while simultaneously making the second worse.


 
   
  Awesome to hear! It wouldn't be for like an orthodynamic that needs a lot of power, but being able to swing the oddity in my collection (Denon D7000) without having a whole separate amp would be great! thanks for the info.


----------



## silverhead

As far as polishing aluminum goes, sorry for the photos of my motorcycle, but this is how I did it cheaply.  In the case of the Crack panel, you can probably start at 800, and work your way to 2000 or 3000 grit sandpaper.   At that point you need some sort of high speed buffing technique using buffing compounds of finer and finer grit.     It can be done cheaply with an electric drill using cloth buffing wheels, but the higher speed you attain, the more mirror-like your results will be.
   
  This is what 1000 grit sandpaper does to aluminum

   
   
  It doesn't look much different from what ships from the Bottlehead company in terms of the way it catches and reflects light.
   
  I used cheap Harbor Freight buffing wheels that cost about 8 dollars for a three pack.  They look like this:
   
  http://www.harborfreight.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/i/m/image_17472.jpg
   
  Then you buy an assortment of buffing compound sticks that look like this.
   
  http://atomictoasters.com/wp-content/gallery/sharpening101-7/buffing-compounds-4oz-bars.jpg
   
  You use grittier or finer compounds on your three wheels.  And don't ever mix them up.  That way you get a more mirror-like finish with each finer buffing wheel you use.  
   
  This is what my engine looked like after getting after it with the drill and buffing compounds.
   

   

   
  Sorry for the off topic photos, but I wanted to let you know that no sand paper, even 3000 grit auto body stuff will give you a mirror finish.  It'll look like 'brushed nickel.'  You need to use some sort of higher speed buffer with compounds to pull out a reflective finish.


----------



## Armaegis

Nice work! How long did that take from sandpaper and up?


----------



## silverhead

About three hours and a lot of elbow grease.  Mostly, I was learning as I went though.  The Crack panel would go more quickly.  The trick is to sand in one direction so you don't have swirl marks the catch the light.  You can buff in multiple directions though.  
   
  The trick with the amp plate is keeping it secure.  I'd probably screw it to a board so there was no chance of bending it because you have to push hard when sanding and buffing.  I'd secure it with flat or domed screws so something solid before pushing on it much.


----------



## Armaegis

Usually when I polish metal samples in the lab, I alternate sanding/polishing directions and criss cross them to sand out the previous lines with each pass. But that's for tiny specimens where I'm going down to nanometer finishes. Large surfaces probably take better or don't care about unidirectional rough sanding.


----------



## ben_r_

You might be able to 3M foam double sided tape it down to something to work on it and then use some Goo Gone afterwards to remove the stickiness from the foam tape.


----------



## EraserXIV

When a tube is approaching its threshold for its mmhos rating, what changes are to be expected? Does the tube sound the same until it fails, or are there noticeable changes that occur as it runs its course?


----------



## silverhead

Tonight when I got home from work, both of my eBay tubes had shown up.  I bought an RCA 6AS7G tube that tested 95/95 and an RCA 12AU7A (clear top) tube that tested 101/102.    It looks awesome with the shouldered tube in there.  The musical aspect of the amp is better.  Stereo separation is wider and the sibilant sounds are handled better.   The only downside is that I hear a 60hz hum out of the power tube and if you pick the amp up and move it around, you get all sort of harmonics out of that tube.   If you tap your finger on the table you hear it through the headphones.  Much like a turntable that is not isolated.
   
  Is the 60hz hum a function of the tube or the filtering capacitors?  (could have something to do with my transformer mounted low?)
   
  The 6080 tube doesn't behave this way and is quiet.   But, the 6AS7G sounds better while music is playing.   The push and shove of analog parts swapping I guess.   Some photos of my rig tonight:
   

   
   
   

   
   
   

   
   
   

   
   
   
  I'm sure everyone has seen photos like this a million times by now, but I'm loving it as a noob.  Laying on the livingroom floor staring into space while listening to music.


----------



## liamstrain

For me the input tube was the hum culprit - not the power tube. The microphonics are a different issue - it shouldn't be that sensitive. Did you only get one 6AS7G - it could just be a bad tube...


----------



## FlySweep

> Originally Posted by *silverhead* /img/forum/go_quote.gif
> 
> 
> 
> ...


 
   
  Those pics were excellent.. love the tube closeups..


----------



## silverhead

I only purchased one tube.  Being new to it all, I am keeping an eye on ebay and trying to purchase the reasonably priced stuff that have decent test numbers.  I realize that doesn't really mean anything if they don't sound OK.   I'm waiting to find someone locally that has a cache of tubes I can try out.    I swapped the Electro Harmonix tube in with the 6AS7G and you still have the same result of the hum and rapping on the case picking up the microphonic noise.    With the original RCA 6080 tube in there, you don't have any hum and tapping on the tube doesn't result in any sort of noise.
   
  The 6080 tube and the clear top RCA combo also sounds really nice.  It'll be fun to build a small collection of both style tubes to try out.  I'm the sort of person that'll watch ebay for mis-listed Telefunken tubes and attempt to snipe them.


----------



## imackler

Does anyone listen via a line out from an ipod compared to a DAC? How much am I wasting the potential of the Bottlehead if I'm just using my ipod' line out? (lossless files)


----------



## liamstrain

Quote: 





silverhead said:


> I'm waiting to find someone locally that has a cache of tubes I can try out.


 
   
  Out of curiosity, where is "locally?"


----------



## FraGGleR

Quote: 





imackler said:


> Does anyone listen via a line out from an ipod compared to a DAC? How much am I wasting the potential of the Bottlehead if I'm just using my ipod' line out? (lossless files)


 
  Depends on the Ipod, I think.  I have a 3G Ipod Touch which sounds very warm and relaxed using a LOD listening to 24/96 files.  More clear than the headphone out, but not nearly as detailed or crisp as when using something as simple as the ODAC.  I don't mind because I specifically bought a 3G instead of a newer one because it was supposed to have a nice warm presentation, which is what I want when traveling.  I haven't heard anything other than my 6G Nano which isn't as musical or dynamic as the Touch, but is a bit more neutral.
   
  This is obviously not with a Crack, but I think in general it holds enough general truth for the question at hand.


----------



## silverhead

Quote: 





liamstrain said:


> Out of curiosity, where is "locally?"


 
  I'm in central Iowa, USA.


----------



## Armaegis

Quote: 





imackler said:


> Does anyone listen via a line out from an ipod compared to a DAC? How much am I wasting the potential of the Bottlehead if I'm just using my ipod' line out? (lossless files)


 
   
  I ran mine off a Fuze and the headphone output of a laptop many times. I didn't feel like I was missing anything too significant other than all my toys weren't being used


----------



## amcananey

Other than buying and building the Crack, which has transformed my HD800s, the greatest improvement in my music listening experience has been *getting away from my computer*!!!
   
  Getting to this point has been nothing short of a revelation. I'm not sitting upright, staring at a computer screen, distracted by the Internet, surrounded by papers and various bits and pieces of office crap. Instead, I'm relaxed, in an armchair (with a footstool), in my study, with nothing but low light, either reading a physical book or just enjoying the music with my eyes closed.
   
  The ipod Touch coupled with Spotify has made it possible. Here is my setup:
   
ipod Touch --> Cable Jive Dock Extender --> Pure i-20 dock --> Blue Jeans Cable coaxial cable --> Audio-Gd Reference 5.32 --> [From here it splits as described below]
   
  RCA outputs on Ref. 5.32 --> Mapletree Audio Design LR1 line router --> [See switch positions below]
  1. Bottlehead Crack
  2. Bottlehead Smack
  3. Mapletree Audio Ear+
  4. Brocksieper Earmax
  5. Emotiva mini-X a-100
  
  XLR outputs on Ref. 5.32 --> Mapletree Audio Design LR1 *Pro* line router --> [See switch positions below]
  1. Violectric V181
  2. Little Dot Mk VI+
  3. Audio-Gd Roc SA
  4. Balanced AMB M^3
   
  This system is great, because the storage capacity of the ipod Touch isn't a limiting factor. With Spotify, the world is my oyster. The Pure i-20 dock extracts the digital (*not* analog) audio stream, and passes it to my external DAC, which in turn feeds all of my amps. No computer and no NAS needed. Just WiFi, and ipod Touch and a Spotify account.
   
  This is obviously complete overkill, but at it's most basic, here is what I recommend:
   
ipod Touch --> Cable Jive Dock Extender --> Pure i-20 dock --> Bottlehead Crack.
   
  The Pure i-20 also has a built-in DAC that is surprisingly good (or, for anyone who has heard my private views on DACs, perhaps not-so-surprising). You just use the RCA outs instead of the coaxial out. And it will charge your ipod while you're listening. For less than $100, it is very hard to go wrong. I have 3 Pure i-20s, and I consider them the Swiss army knife of audio gear - incredibly versatile and shockingly cheap for what they do.
   
  FWIW, the Cable Jive cables are ridiculously overpriced. Unfortunately, they are also the best cables of their kind that I have seen, and therefore recommended. Note that when I say "best", I'm not implying that they have any effect on sound quality, it is just that they are very robustly built and I find most ipod cables start to crack shockingly fast. The Cable Jive cable lets me hold my ipod Touch in my hand when selecting music, rather than trying to awkwardly manipulate it while it is plugged into the dock itself.
   
  Best regards,
  Adam


----------



## m17xr2b

Quote: 





imackler said:


> Does anyone listen via a line out from an ipod compared to a DAC? How much am I wasting the potential of the Bottlehead if I'm just using my ipod' line out? (lossless files)


 

 In my case it did not make a difference with various sources until I went for a hi end dac(Ad Labs RD26 850$). The detail now from the HD700 is really breathtaking. I don't regret the purchase one bit as I hear that the soundstage is larger, instrument separation is perfect.


----------



## teb1013

I came to within one click of getting one of these! I want a tube amp badly and the increase of quality over similarly priced imported product had me convinced. Then I remembered my clumsy attempts at building things as a kid. I'm truly all thumbs and the projects I undertook (including a disasterous attempt at a Hethkit radio I got as a gift) made me realize that I was fooling myself in thinking that this time I'd do better. Although the Bottlehead site suggests that assembly is available, Doc B's recent posting says this has been discontinued. Too bad! Doc if this situation changes I'll be first in line.


----------



## lextek

Quote: 





teb1013 said:


> I came to within one click of getting one of these! I want a tube amp badly and the increase of quality over similarly priced imported product had me convinced. Then I remembered my clumsy attempts at building things as a kid. I'm truly all thumbs and the projects I undertook (including a disasterous attempt at a Hethkit radio I got as a gift) made me realize that I was fooling myself in thinking that this time I'd do better. Although the Bottlehead site suggests that assembly is available, Doc B's recent posting says this has been discontinued. Too bad! Doc if this situation changes I'll be first in line.


 
  I had such a great time building mine.  I'd build one for you.


----------



## Mak333

Quote: 





amcananey said:


> Other than buying and building the Crack, which has transformed my HD800s, the greatest improvement in my music listening experience has been *getting away from my computer*!!!
> 
> Getting to this point has been nothing short of a revelation. I'm not sitting upright, staring at a computer screen, distracted by the Internet, surrounded by papers and various bits and pieces of office crap. Instead, I'm relaxed, in an armchair (with a footstool), in my study, with nothing but low light, either reading a physical book or just enjoying the music with my eyes closed.
> 
> ...


 

 Adam - While I can't say my Crack isn't "laced" with a PC, I 100% agree with your opinion.  Having a long headphone cable (stock) with the HD-600s is also a benefit, because while I'm running all my music from my PC (USB out to a KECES DAC) I am able to get away from the monitor, computer, and the area in general to truly listen without any distraction.
   
  Back to your point - It's the _distraction_ that makes a huge difference in what my brain is able to process from a musical standpoint.  Now maybe other fellows on here can still point out every detail while surfing the Head-Fi forums, but I can't!  I enjoy music best with my eyes closed and zero distractions.


----------



## ben_r_

Im with ya Mak333. When I want to enjoy just music and nothing else I have my headphone listening area where I can comfortably lay with my eyes closed and enjoy the experience without distractions.


----------



## TheKillerPiglet

I have a couch right behind the chair in my home office, just plop down on that. Also just got a 25' Mogami extension so I can reach the couch in my speaker room (very quiet there) or the couch in the Florida room.
   
  Come to think of it, if I drop this cable through the window I can listen in the backyard...
   
  KP


----------



## ben_r_

Quote: 





thekillerpiglet said:


> I have a couch right behind the chair in my home office, just plop down on that. Also just got a 25' Mogami extension so I can reach the couch in my speaker room (very quiet there) or the couch in the Florida room.
> 
> Come to think of it, if I drop this cable through the window I can listen in the backyard...
> 
> KP


 

 LOL I know and own the exact same cable!


----------



## EraserXIV

So I got around to refinishing the base. Sanded it down, restained it with ebony, and put a few layers of satin poly over it. Also drilled some holes on the bottom for some rubber feet to help with ventilation and sliding around. Looks great in person, the cell phone picture doesn't really do it justice but that's all I have right now. Pretty happy with the results.
   
  Before:
   

   
   
  After:


----------



## liamstrain

That looks great, Eraser.


----------



## FlySweep

Anyone know of a good place to get a _single_ Tung Sol 5998?  eBayers are all selling them as pairs & the TubeDepot's, etc. of the world are sold out.
   
  Am I going to have to buy a pair and sell one?  Yeesh.


----------



## swmtnbiker

+1
   
  Been looking for a while...


----------



## EraserXIV

Yeah that and they've been going for ridiculous prices too. Pretty sure it'd be easy to sell in the FS forums though if you do get a pair for a reasonable price.


----------



## liamstrain

I like having a pair anyway. A spare tube isn't a bad thing to have around given that they are a consumable.


----------



## EraserXIV

Quote: 





liamstrain said:


> I like having a pair anyway. A spare tube isn't a bad thing to have around given that they are a consumable.


 
   
  Good point, they're likely to only go up in price too.


----------



## j123my

You can buy a pair and sell one if you must. I did that and ended up keeping both, though, so be careful.. 
	

	
	
		
		

		
			





 Looks like vacuumtubes.net has some 5998's. But I have to say I have no experience with them, I got mine NOS from a headfier sometime ago.


----------



## ben_r_

Single Tung Sol 5998's right here folks: LINK
   
  This is where I bought mine.


----------



## GrindingThud

Where I got mine as well. Very nice business with good communications and fast shipping.


ben_r_ said:


> Single Tung Sol 5998's right here folks: LINK
> 
> This is where I bought mine.


----------



## Mak333

Brent Jesse Recording Inc. might have some?
   
  http://www.audiotubes.com/bjtubes.htm


----------



## swmtnbiker

Quote: 





grindingthud said:


> Where I got mine as well. Very nice business with good communications and fast shipping.


 
   
  I've emailed them twice today with zero response. Not a very good first impression.


----------



## darrellpratt

Just finished my Crack tonight. I should be sleeping but I'm enjoying my Sennheiser HD650s with some Tortoise playing.


----------



## ben_r_

Quote: 





swmtnbiker said:


> I've emailed them twice today with zero response. Not a very good first impression.


 

 Call. Thats what I did.


----------



## Beefy

Quote: 





swmtnbiker said:


> I've emailed them twice today with zero response. Not a very good first impression.


 
   
  Indeed. I mean hell, how did commerce ever possibly proceed before the days of instantly answered emails?


----------



## BmWr75

Quote: 





swmtnbiker said:


> I've emailed them twice today with zero response. Not a very good first impression.


 
   
  Patience Grasshopper (am pretty sure you won't get this 1970s TV reference).  Tube selling is a side-line business for many people.


----------



## Mak333

darrellpratt - Looking good.  Would like to see more shots from different angles!  Maybe one from under the hood too!


----------



## swmtnbiker

Quote: 





beefy said:


> Indeed. I mean hell, how did commerce ever possibly proceed before the days of instantly answered emails?


 
   
  Quote: 





bmwr75 said:


> Patience Grasshopper (am pretty sure you won't get this 1970s TV reference).  Tube selling is a side-line business for many people.


 
   
  Geez guys, cut me some slack will ya? 
	

	
	
		
		

		
			





 They have an email address for a reason, no? It should be no different than making a phone call. Pet peeve of mine. If you offer your customers three different email addresses as a means of contacting your business, then answer your messages during normal business hours. Especially sales inquiries. And I don't know if I'd categorize a company that boasts having an "inventory of over 12 million tubes in stock!" as a side business.
   
  BTW BmWr75, I got your reference just fine. Now I'm gonna go walk the Earth while I wait for my email to be answered...


----------



## ben_r_

Just pick up the phone and CALL. I tried emailing at first too and got nothing, then I called and got everything answered and squared away and was emailed an invoice shortly after.


----------



## swmtnbiker

Timing doesn't work for me. I'm 3 hours behind EDT and it's problematic to make personal calls during working hours. They just need to answer their email. I don't NEED that tube...


----------



## FlySweep

I emailed vacuumtubes.net a couple of days ago (right after Jeremy posted the link) about wanting to purchase a 5998.. got a reply back within two hours.. they needed my shipping address).. I responded right away with it.  Got an email from them yesterday to let me know the 5998 has shipped.  Very smooth transaction and excellent service in my case.


----------



## BmWr75

Quote: 





swmtnbiker said:


> BTW BmWr75, I got your reference just fine. Now I'm gonna go walk the Earth while I wait for my email to be answered..


 
   
  If you see any boiling cauldrons, don't pick them up.


----------



## swmtnbiker

But then I won't have those cool dragon brandings on my forearms...


----------



## ben_r_

Quote: 





swmtnbiker said:


> Timing doesn't work for me. I'm 3 hours behind EDT and it's problematic to make personal calls during working hours. They just need to answer their email. I don't NEED that tube...


 

 They are about the only ones you can get NOS ones from though, so you might have to take a 15 minute break from work and give them a call.


----------



## swmtnbiker

No need. They finally got back to me.


----------



## silverhead

Every fringe hobby I have requires calling people on the phone.  Mostly because the people I'm dealing with aren't internet savvy or they're too busy repairing things during the day to have time to sit around watching email.  Some of them don't even like to be called (in the case of antique camera repairmen.)   I've just been sitting around taking potshots at ebay auctions and after two weeks' time, I have about 8 6AS7G tubes and about 6 12AU7 tubes sitting here at home.   
   
   
  Speaking of which, the 6AS7G tubes have 'hum' but this hum I'm referring to is constant from volume setting zero all the way to maxed out.   So I'm starting to wonder if it's not the tubes themselves, rather I might be overtaxing some part of the Crack?   Do I need bigger electrolytic capacitors somewhere?    Because it's not really noise from a bad signal since I can hear it at zero volume and it's the same intensity throughout the volume range.     Is there a name for this condition?


----------



## darrellpratt

Quote: 





mak333 said:


> darrellpratt - Looking good.  Would like to see more shots from different angles!  Maybe one from under the hood too!


 
   
   
   

   
   
  The innards right before testing.  I was impressed that everything tested fine after the build.  I did screw up a few bits while building but caught them quickly.  The parts are bone stock at this point.  I didn't want to mess with any upgraded caps or resistors before knowing what it would sound like stock. 
   
   

   
  Basically the same angle.  I just put on a coat of paste wax this morning so I'll get some other glamour shots this weekend.


----------



## Doc B.

Sounds like your tubes have some heater-cathode leakage. The solution is to use a different tube.


----------



## silverhead

Quote: 





doc b. said:


> Sounds like your tubes have some heater-cathode leakage. The solution is to use a different tube.


 
  OK, will do!   This  humming noise comes and goes if you tap on the tube with a pencil and then comes back after a bit.
   
  Is there a technical reason for what's happening like part of the guts that aren't supposed to be touching actually are, or something?  The guy I bought the tube from claimed it tested 95/95 and had 'no microphonics.'    Meanwhile if you tap it lightly with a pencil it sounds like a mule kicking a spring reverb in a guitar amp.


----------



## Doc B.

Well, maybe he meant that it had no microphonics when it was not plugged into an amp.


----------



## EraserXIV

Quote: 





doc b. said:


> Well, maybe he meant that it had no microphonics when it was not plugged into an amp.


----------



## silverhead

I gave him the benefit of the doubt that the postman was playing football with the package on the way to my house.
   
  The hum isn't all that loud (you quit hearing it as soon as you start playing music at low volume.)    How risky is it to use leaking tubes though in terms of them going 'full short' ??


----------



## Doc B.

As long as it isn't crackling or popping it will probably be OK. And sometimes the hum can reduce with some burn time. Sometimes not.


----------



## silverhead

This is a circa 1943 RCA 6AS7G.  I noticed people online doing things like baking them in the oven to 'dry out' the bakelite base in case of shorting that way.   I presume the heat generated while being used would cause that moisture to flee the base though.    I'm going to test the 'bulb' from the base to make sure it's not loose tonight.  I'd love for it to quiet down because I really like the way it sounds.     I need to befriend someone locally with a tube tester and the knowledge required to use it.


----------



## darrellpratt

silverhead said:


> This is a circa 1943 RCA 6AS7G.  I noticed people online doing things like baking them in the oven to 'dry out' the bakelite base in case of shorting that way.   I presume the heat generated while being used would cause that moisture to flee the base though.    I'm going to test the 'bulb' from the base to make sure it's not loose tonight.  I'd love for it to quiet down because I really like the way it sounds.     I need to befriend someone locally with a tube tester and the knowledge required to use it.




Not sure what circa I have, but I've got no noise. I can post a pic tonight of it. In fact have three spares.


----------



## skeptic

How do the pins look on that tube silverhead?  Back in mid-2011, I had an RCA12bh7 blackplate with an unfortunate hum issue, and Doc suggested buffing the pins with fine steel wool as a possible fix.  I used fine grain sand paper, in the absence of steel wool, and then inserted and removed the tube a dozen or so times.  The hum was completely eliminated.
   
  I don't know if this has the same probability of success on a power tube, but I figured it would be worth tossing out there.


----------



## silverhead

I get after everything that comes to the house with Caig DeOxit D5 and Q-tips.   I can try to burnish the tips, but they're already pretty clean and newish looking   I have 00 steel wool to try though.   My guess is that it took a hard knock on the USPS truck.  I have more coming in the mail.
   
  I've been trying to score oddball 12AU7 equivalents to see what sort of differences I hear as well.  It's been fun.


----------



## igotyofire

does anyone know what this amp is worth fully assembled & built without the upgrade kit?


----------



## elwappo99

Quote: 





igotyofire said:


> does anyone know what this amp is worth fully assembled & built without the upgrade kit?


 
   
  Hard to say. I've been looking around for awhile and it seems they basically go for the price of the kit,* if they are built well*. Everything I've read on the bottlehead forums is pretty wary of buying prebuilt kits because if any issues show up down the road they are hard to pinpoint. If the kit isn't built well it could easily be a mess. 
   
  edit: Should also add you shouldn't sell the kit for more than it costs directly from bottlehead on the head-fi forums unless you are a member of the trade.


----------



## richbass

Is it sold as assembled or only diy kit ?


----------



## igotyofire

Quote: 





richbass said:


> Is it sold as assembled or only diy kit ?


 
   
  it is a DIY kit, but bottlehead will assemble it for a fee im pretty sure. I was part of the first groupbuy i believe for the Crack amp . I don't really use the amp anymore but still deciding on whether I want to keep it or not, I have an emotional attachment too actually since I built it.  I haven't been on head-fi for awhile, pursuing other hobbies. The only thing I cant seem to live without is IEMs though.


----------



## Doc B.

We no longer build amps for customers. My techs are hired for R&D work and they don't have the time to fit kit assembly into their schedule any more. But anybody can build one of these kits. There are literally thousands of Bottlehead kits out there that have been built by beginners.


----------



## swmtnbiker

I've been enjoying my Crack + Speedball immensely over the past weeks and have been playing around with tube rolling to some degree. I found a NOS Tung-Sol 6080 that I really love, and I've tried two different 12AU7s in addition to the stock tube. One of them is my favorite as it noticeably adds some air and high frequency extension. Today, however, I finally received my 12AU7/6SN7 adapter from China and was able to try out a vintage Tung-Sol 6SN7 that I picked up from a local tube seller.
   
  Oh. My. God.
   
  I think I'm in audio nirvana! My rig has NEVER sounded this dynamic or detailed. Soundstage seems to have almost doubled. Air and separation around instruments is much, much better, and there is some serious PRAT happening as well. The Crack sounded fantastic before, but adding this 6SN7 to the signal path has just opened it up and elevated the listening experience to a whole new level. This is probably the most blatantly apparent improvement I've ever heard from a tube roll. I think that little $14 adapter just saved me a whole lot of money, because I can't imagine this particular audio chain getting much better than this. It looks a bit ghetto compared to having a 12AU7 alone in the socket, but I think I can live with that.
   
  Sorry for gushing, but I'm sitting here almost stupefied after listening to some of my most familiar test tracks for a half hour. So much for the list of chores I was going to get done today!!


----------



## TheKillerPiglet

Agree, I have tried about 10 different old USA 6sn7's, all work very well. Tung sol long plates are top three. Try a Sylvania chrome top and GE 5 Star 6080 if you can.
   
  KP


----------



## lextek

Quote: 





swmtnbiker said:


> I've been enjoying my Crack + Speedball immensely over the past weeks and have been playing around with tube rolling to some degree. I found a NOS Tung-Sol 6080 that I really love, and I've tried two different 12AU7s in addition to the stock tube. One of them is my favorite as it noticeably adds some air and high frequency extension. Today, however, I finally received my 12AU7/6SN7 adapter from China and was able to try out a vintage Tung-Sol 6SN7 that I picked up from a local tube seller.
> 
> Oh. My. God.
> 
> ...


 
  Yeah the 6SN7 does add something.....


----------



## swmtnbiker

Indeed it does, and thanks for the recommendations KP.


----------



## Jmstrmbn

Quote: 





swmtnbiker said:


> I've been enjoying my Crack + Speedball immensely over the past weeks and have been playing around with tube rolling to some degree. I found a NOS Tung-Sol 6080 that I really love, and I've tried two different 12AU7s in addition to the stock tube. One of them is my favorite as it noticeably adds some air and high frequency extension. Today, however, I finally received my 12AU7/6SN7 adapter from China and was able to try out a vintage Tung-Sol 6SN7 that I picked up from a local tube seller.
> 
> Oh. My. God.
> 
> ...


 
   
  I'm curious, what headphones are you using with this combo?


----------



## swmtnbiker

Sennheiser HD 650.


----------



## j123my

I think I'll dig up my adapter, buy a nos tube, and try 6sn7 once more. I swear I wasn't impressed with the 6sn7 tubes I tried sometime ago (and decided to stick with 12au7). But since people keep saying so, well.. I do hope I am missing something.


----------



## swmtnbiker

Obviously, you are...


----------



## silverhead

I bought five 6AS7G tubes off of ebay and the seller sent them to me in a generic Cap'n Crunch cereal box!  5 tubes bouncing around in a cereal box.   This is a seller on ebay who is selling a lot of tubes. 
   
   

   
   
  Anyway, they all ended up sounding great.  No microphonics, no 60hz hum.  All five of them work and do their thing.  
   
  I'm digging this Raytheon tube.  The others were unmarked or RCA.


----------



## liamstrain

Glad it proved to be a bad tube (and that the new ones were not damaged... were they wrapped up in that box at all?). That Raytheon looks great too.


----------



## silverhead

Yep.  The tube sold on ebay, tested NOS with "no microphonics" from a major tube seller ended up being messed up and the bargain bin ones are all fine, haha.
   
  They were all wrapped in one roll of bubble wrap and just dropped loosely into the cereal box.  I'm amazed that they survived.  Also, they would have fit into a USPS flat rate box which is more sturdy, costs less to ship, and is -free- at the post office, ha!


----------



## darrellpratt

Seems the packing worked. Since they went the extra mile over a flat rate box I hope you gave them 5 stars on shipping. 



silverhead said:


> Yep.  The tube sold on ebay, tested NOS with "no microphonics" from a major tube seller ended up being messed up and the bargain bin ones are all fine, haha.
> 
> They were all wrapped in one roll of bubble wrap and just dropped loosely into the cereal box.  I'm amazed that they survived.  Also, they would have fit into a USPS flat rate box which is more sturdy, costs less to ship, and is -free- at the post office, ha!


----------



## silverhead

Quote: 





darrellpratt said:


> Seems the packing worked. Since they went the extra mile over a flat rate box I hope you gave them 5 stars on shipping.


 
   
  It worked out, but I just just put off a bit when the mail lady showed up Friday afternoon with a box of cereal, haha.  Here's an unpacking video I made with my phone.
   




   
  But, the end result is what matters, and they all test as quiet and working.   For whatever reason, the 6AS7G play louder than the two 6080 tubes I have.   The 6080 tubes get way hotter.


----------



## Armaegis

Oh that's a lot better than I thought from your initial description which made me think all of them were wrapped up in one piece of bubble wrap and dropped in a box. They're all individually wrapped, there's foam peanuts, and extra cardboard in there. S'all good.


----------



## silverhead

I was mostly disappointed it wasn't Capn Crunch.


----------



## eantala

guys I tried 2 different 6sn7 (a black glass ken rad and a sylvania ) and the sound is absolutely fantastic, however its very microphonic, you have to shift around till reduce the noise/hum..
  and if you adjust to reduce the noise by ear you will hear alot of crackles/pops..I can never get the black background I get with the 12au7..Im not sure if its just my adapter, are you guys getting noise?
  is there something you can do to eliminate the noise like a tube shield cover?


----------



## amcananey

I also found 6SN7s to be loud. I don't see any reason to use them. I've tried 12AU7s, 12BH7s and E80CCs and they all seem superior/quieter to me.


----------



## richbass

Anybody has the mW rating @ 300 and 600 ohms ?


----------



## Doc B.

We spec the max voltage output before clipping into 300 ohms as 10Vrms. That would be a power output of about 100V^2rms/300ohms = 333mW rms. Sorry to say I don't have a measurement for 600 ohms handy, but it will probably be pretty close. I can say that the 300 and 600 ohms headphones I have tried have had plenty of output with a reasonable source level.


----------



## silverhead

Quote: 





doc b. said:


> That big ol' 6080 heater sucks up a lot of current and the power trans is running pretty much at the design limit current-wise with the addition of the 300mA heater draw of the 12AU7. We felt that the additional 300mA current draw of the most likely octal candidate, 6SN7, would tax it.


 
   
  I just put in an order from Hong Kong for an adapter to try 6SN7 tubes on my amp.  Do 6AS7G power tubes use less heater current?   I notice my aluminum top plate stays much cooler with the 6AS7G tubes than with the two 6080 tubes I have. 
   
  Thanks!


----------



## Doc B.

6080 and 6AS7 are essentially identical. But don't worry about using a 6SN7, since I posted that we have determined that the power transformer can handle the extra current draw.


----------



## silverhead

For whatever it's worth, my transformer doesn't really get that warm.


----------



## EraserXIV

I was auditioning the built-in amp on my D100 for a while as I was surprisingly impressed by it. Once or twice I almost caught myself questioning if it was worth keeping the Crack around. However, after switching back to the Crack with a newly arrived 5998 it was as a "veil" was lifted (I _hate _to use that word but it really is the best word to describe it). A whole new layer of clarity and detail while still being silky smooth. Sound was more natural and airy, imaging and soundstage much better. Sounded as if I was in the the same room as the singer and they were personally serenading me. The lush, sweet mids were the highlight for me.
   
  Before, I was using an RCA 6AS7G and the difference between the built-in amp on the D100 and the Crack was much less pronounced (the Crack still being better, but not as obvious).


----------



## VALIENTE

Hello guys, anyone among you know the weight in lbs or kg of the headphone amplifier kit because I will use it to compute for its shipping fee. Thank you!


----------



## Doc B.

7lbs.


----------



## VALIENTE

Quote: 





doc b. said:


> 7lbs.


 
  Thanks Sir. Can I know the dimensions of its box, length, width and height please? And also about the 240V AC transformer, can it be placed inside the amplifier kit box, or it comes on another box? And if yes, what its weight and dimensions? Thank you.


----------



## Doc B.

One box, 10"x12"x6". It's probably easiest to simply contact Eileen at queen at bottlehead dot com and ask her what the shipping would cost.


----------



## rs01

For anyone that's put in some big/upgraded caps, how did you mount them?  I'm thinking of using a metal punch to punch holes in the alloy top plate and then using some screw-in zip tie mounts, but would like to hear what anyone else has done.  The caps will be Mundorf M-Cap 100uf/250v, so they're just under silly-huge size for the chassis .


----------



## BmWr75

I used peel and stick zip tie anchors, 2 per cap.  But, I also routed the fly wires so they helped hold the large caps to the bottom of the plate.


----------



## ben_r_

Quote: 





rs01 said:


> For anyone that's put in some big/upgraded caps, how did you mount them?  I'm thinking of using a metal punch to punch holes in the alloy top plate and then using some screw-in zip tie mounts, but would like to hear what anyone else has done.  The caps will be Mundorf M-Cap 100uf/250v, so they're just under silly-huge size for the chassis .


 

 Right here man: LINK


----------



## GrindingThud

That is a very cool website....



ben_r_ said:


> Right here man: LINK


----------



## skeptic

rs01 said:


> For anyone that's put in some big/upgraded caps, how did you mount them?  I'm thinking of using a metal punch to punch holes in the alloy top plate and then using some screw-in zip tie mounts, but would like to hear what anyone else has done.  The caps will be Mundorf M-Cap 100uf/250v, so they're just under silly-huge size for the chassis .




I used a cheap cordless drill to punch through the top plate, but otherwise this is exactly what a number of us have done. Be prepared to dispose of your bit afterwards. The adhesive on the zip tie mounts is pretty strong in its own right but can theoretically fail over time due to heat. Screws are a worthwhile precaution imo.


----------



## Beefy

rs01 said:


> For anyone that's put in some big/upgraded caps, how did you mount them?  I'm thinking of using a metal punch to punch holes in the alloy top plate and then using some screw-in zip tie mounts, but would like to hear what anyone else has done.  The caps will be Mundorf M-Cap 100uf/250v, so they're just under silly-huge size for the chassis .




I used these, attached to the top plate with screws, exactly as you plan to do: http://www.homedepot.ca/product/uv-black-mounting-base-bag-of-8/977480
It works very well, but I would recommend drilling rather than punching.



bmwr75 said:


> I used peel and stick zip tie anchors, 2 per cap.  But, I also routed the fly wires so they helped hold the large caps to the bottom of the plate.




Those mounts WILL fail due to heat over time, and your caps will be hanging by their wires. Not a good outcome. The zip tie anchors should absolutely be held in place with screws.


----------



## rs01

Cool, thanks for the responses everyone.  The capacitor holder looks pretty much perfect Ben, but I might just go forward with the zip tie anchor with screws and ties since I can grab everything I need from Home Depot on the way home from work.


----------



## Doc B.

Quote: 





skeptic said:


> . Be prepared to dispose of your bit afterwards.


 
  The panel is aluminum. Any decent bit will come out unscathed, particularly if one uses a proper cutting fluid. A spritz of WD-40 will work, as will a bit of candle wax on the tip of the bit.


----------



## silverhead

Is there a generally agreed upon 'giant capacitor' to upgrade to?  I know that they all have some sort of impact on the sound quality, but is there a universal holy grail that people would flock to if money was no option?   I don't plan to put the speed ball upgrade onto this one I have because I like something about the lack of solid state anything on board.  I guess the tiny LEDs technically count... but yeah.
   
  I'm thinking about ordering another kit so I can get the pleasure of building it myself as well as having one of them at work so I could be listening right this instant.   And it's the beginning of the month, so I just got paid (yeah!)


----------



## ben_r_

Quote: 





silverhead said:


> Is there a generally agreed upon 'giant capacitor' to upgrade to?  I know that they all have some sort of impact on the sound quality, but is there a universal holy grail that people would flock to if money was no option?   I don't plan to put the speed ball upgrade onto this one I have because I like something about the lack of solid state anything on board.  I guess the tiny LEDs technically count... but yeah.
> 
> I'm thinking about ordering another kit so I can get the pleasure of building it myself as well as having one of them at work so I could be listening right this instant.   And it's the beginning of the month, so I just got paid (yeah!)


 

 There are really only two that anyone gets now a days and I doubt anyone could tell the difference between them. They are the Mundorf's and the Obligatto's.


----------



## Armaegis

Quote: 





doc b. said:


> The panel is aluminum. Any decent bit will come out unscathed, particularly if one uses a proper cutting fluid. A spritz of WD-40 will work, as will a bit of candle wax on the tip of the bit.


 
   
  Huh, I've never heard of using candle wax before. I'll have to give that a try sometime.


----------



## liamstrain

Quote: 





silverhead said:


> I know that they all have some sort of impact on the sound quality, but is there a universal holy grail that people would flock to if money was no option?


 
   
  This is not generally agreed upon, and especially not in this particular circuit.


----------



## rs01

Quote: 





liamstrain said:


> This is not generally agreed upon, and especially not in this particular circuit.


 

 I agree - personally I'm not really expecting a noticeable sonic change by adding the big caps, I'm doing it more out of my desire to keep tinkering with the amp.  I've already changed the pot, added a bypass cap, added the Speedball, rolled a bunch of different tubes, etc, and adding new output caps is just another step on the tinkering path.


----------



## amcananey

That was exactly why I did it. I installed Clarity Cap ESA 100 mfd 250V caps that I got from Madisound here.
   
  I wound up using some plastic straps used to mount the large vent tubes from clothes driers to hold the caps in place. Ultimately, I thought this solution worked quite well, because there was adequate separation between the caps and the rest of the chassis. The plastic straps are extremely robust (they can hold hundreds of pounds), can be easily cut to size using household scissors, are quite cheap and won't scratch the caps. For pictures, see here.
   
  On the downside, this means I have to desolder the caps every time I need to do anything to the amp, because the caps are secured to the side of the wooden case, and need to be separated from the metal plate. But since you have already upgraded everything else, this should be less of a concern.
   
  I should also add that the size of the caps, and the need to create clearance between the caps and the other components, means that I also had to raise the wooden case a bit. I wound up using adjustable/extendable feet, but you could do whatever works best for you.
   
  Best,
  Adam


----------



## rs01

Quote: 





amcananey said:


> That was exactly why I did it. I installed Clarity Cap ESA 100 mfd 250V caps that I got from Madisound here.
> 
> I wound up using some plastic straps used to mount the large vent tubes from clothes driers to hold the caps in place. Ultimately, I thought this solution worked quite well, because there was adequate separation between the caps and the rest of the chassis. The plastic straps are extremely robust (they can hold hundreds of pounds), can be easily cut to size using household scissors, are quite cheap and won't scratch the caps. For pictures, see here.
> 
> ...


 

 The 78mm diameter is crazy, the Mundorfs I bought I think are 48mm and they'll be enough of a challenge to mount.


----------



## amcananey

Quote: 





rs01 said:


> The 78mm diameter is crazy, the Mundorfs I bought I think are 48mm and they'll be enough of a challenge to mount.


 
   
  Where is the challenge in that? 
	

	
	
		
		

		
			




   
  It's the tinkering that is fun...the harder the better!


----------



## amcananey

Actually, when I first got them, I didn't think they were going to fit.
   

   
   So I first tried different orientations:
   

   

   
  Actually, I was initially tempted to just send them back. But I finally found a mounting solution that worked:
   

   
  As you can see, these straps provide excellent clearance from the metal plate and components. The caps aren't touching anything else. The straps themselves were cheap. A whole roll of that light gray plastic material only cost a couple of bucks and worked like a charm.
   
  Here you can see the adjustable feet I installed to raise the height of the case to clear the caps hanging down:


----------



## Armaegis

Every time I see these giant caps I get this funny idea to build an amp into a Tonka truck and use the caps as wheels...


----------



## skeptic

Quote: 





doc b. said:


> The panel is aluminum. Any decent bit will come out unscathed, particularly if one uses a proper cutting fluid. A spritz of WD-40 will work, as will a bit of candle wax on the tip of the bit.


 
   
  The panel was no problem.  It was the unpunched adhesive backings on my four zip tie mounts that thoroughly gunked up the bit.  Appreciate the advice about working with aluminum in general though!


----------



## Doc B.

Acetone might be good for cleaning off the sticky pad residue. FWIW the pads we buy have the screw hole in them already. You can easily poke the screw through the adhesive foam under the hole.


----------



## Jasper9395

I am going to build a crack with speedball soon, I am going to build it in stock configuration first to see how it sounds. Now I will be using it with my HD650s which are 300 ohms. I will eventually be wanting to upgrade the output capacitors. I was thinking of using a Clarity cap SA with a 47uf value and bypassing it with a Mundorf M-cap with 4.7uf. According to Tony Gee who runs humblehomemadehifi this mix works quite well. This would give me a cutoff frequency of 10.3hz with the 650s. Is this a sound plan or am I missing something?


----------



## dsound

I'm in week 2 of Crack ownership and it's been great.  Props to Doc and his team for putting out a great product.
   
  I ordered a Chatham 5998 
	

	
	
		
		

		
			





  .  I'm currently using a RCA 6AS7G so I'm pretty excited to hear the differences in my (stock) crack.
   
  Pic of completed kit:


----------



## ben_r_

Anybody use their Crack to power two headphones at the same time? Say if I wanted to run two HD-650's off it with a parallel Y splitter? Seems to have WAY too much power output for a single set of HD-650's, so Im thinking there should be plenty of power left for a second.


----------



## dsound

@ ben_r_
   
  I don't think it should be a problem since most people report that the Crack does fine with 600ohm headphones..
   
  Since 2x 650 @ 300 Ohm = 600 Ohms that should be fine.
   
  Here's a similar post that corroborates this:
  http://www.head-fi.org/t/612316/headphone-splitter


----------



## Doc B.

No, two 300 ohm headphones in parallel would make a 150 ohm load. That's still OK for the Crack but perhaps not quite as optimal. As regards power, you can't really have too much as long as you are careful not to blow the headphones with signal (that would blow your ears too). Do you perhaps mean there is too much gain? That is a different issue that has to do with how high the output of the source feeding the Crack is.


----------



## dsound

I stand corrected 
	

	
	
		
		

		
		
	


	




 .  Thanks for the clarification.


----------



## ben_r_

Quote: 





doc b. said:


> No, two 300 ohm headphones in parallel would make a 150 ohm load. That's still OK for the Crack but perhaps not quite as optimal. As regards power, you can't really have too much as long as you are careful not to blow the headphones with signal (that would blow your ears too). Do you perhaps mean there is too much gain? That is a different issue that has to do with how high the output of the source feeding the Crack is.


 

 Gain is what I was referring to sorry Doc B. And yes it is directly proportional to the incoming signal. That being said do you think it would be better to split the headphone out in series for a 600 ohm load?


----------



## Doc B.

I would run two headphones in parallel rather than series, but it wouldn't hurt anything to try it both ways.


----------



## ben_r_

Quote: 





doc b. said:


> I would run two headphones in parallel rather than series, but it wouldn't hurt anything to try it both ways.


 

 Very true. I would think the Crack would perform better with a 600 ohm load rather than a 150 ohm, but Im only basing that on what Ive read around the net with various headphone combinations.
   
  Doc B, I had another question, I have them both, but since one is already mounted and installed its easier to just as here: the PT-7 is the exact same size and shape have can use the same mounting hold cutouts as the PT-3 correct?


----------



## Mak333

Quote: 





ben_r_ said:


> Very true. I would think the Crack would perform better with a 600 ohm load rather than a 150 ohm, but Im only basing that on what Ive read around the net with various headphone combinations.
> 
> Doc B, I had another question, I have them both, but since one is already mounted and installed its easier to just as here: the PT-7 is the exact same size and shape have can use the same mounting hold cutouts as the PT-3 correct?


 

 I don't believe changing the headphones changes the resistance of the amp.  I'm not knowledgeable when it comes to this stuff, but I do believe that changing what the amp outputs to, doesn't affect the performance of the amp, but only the output device.


----------



## BmWr75

Quote: 





mak333 said:


> I don't believe changing the headphones changes the resistance of the amp.  I'm not knowledgeable when it comes to this stuff, but I do believe that changing what the amp outputs to, doesn't affect the performance of the amp, but only the output device.


 
   
  Just because you don't believe, doesn't mean it isn't true.


----------



## silverhead

My 6SN7 to 12AU7 adapter(s) showed up from China finally.   The first one (nice, gold looking one) doesn't work.   The second one that showed up does work, however.
   
  Do you run the risk of toasting the transformer by using this setup with no other modifications?
   
  My unprofessional opinion is that compared to my RCA clear top 12AU7, the  GE and HP 6SN7 tubes I bought cheaply, both sound nice.   I'm getting more output out of them (louder in the headphones at the same volume setting) than 12AU7 tubes.
   
  This is my opinion about how the sound has changed:  Less sibilance out of 'S' words, as if maybe the high end is more compressed.  Boomier bass at the 80ish-150hz range which is somewhat annoying.   But otherwise, stereo separation seems to be slightly wider and the sound is a bit more tight and punchy.  Sort of like taking a little hit of nitrous oxide where the whole world feels a bit more refreshing, rubbery, and springy.  Like being thrown into a padded cell after winning the lottery..   I'm not sure I'm good at describing what I'm hearing, but I think the 6SN7 tube can make the hairs on the back of your neck stand up better with some songs than the 12AU7.  
   
  It looks weird having one jammed into the front of the amplifier though.   I haven't yet researched what brands or models of the 6SN7 are desirable.  I paid 5 bucks for this pair.  Both are made by GE (one was made by GE for HP.)  So they look identical and sound identical to my ears.  
   
  Does anyone have the pinout so I can figure out why the nicer looking one is broken?
   
  By the way, this is the one that doesn't work:
   

   
   
  It's got a nice ceramic top with gold plated pins and sockets.
   
  Meanwhile, this one works fine
   

   
   
  It looks to be of lesser quality, but it works... It also costs less on ebay.     I'm trying to figure out how to take the white one apart, but I think it's expoxied together. 
   
  And since I'm bored, I figured out the pinout combos of both adapters.  The 'nicer' looking one has two mixed up connections:


----------



## BmWr75

I've got one like the one you have that doesn't work.  Mine works fine.


----------



## silverhead

I wish I knew how to take it apart.. But I think it's glued together.  Otherwise I'd fix the connection mix up.


----------



## mink70

I've owned a Crack that I bought from a fellow Head-Fier for several weeks, and I have to say that my initial impression with the HD800 and HD650 was not great. Compared to my JDS Labs  portable C421 op-amp powered unit (about $170), the Crack sounded bassy, rolled off on top, slow and lacking in detail—poky and boring. This was with a Sylvania 12BH7 driving a Tung Sol 6080. What I've discovered since is that the Crack is more responsive to tube rolling than any piece of equipment I've ever heard. Which is to say, unbelievably so.
   
  Since then: I tried plenty of 12AU7s—Telefunken (my fave), Amperex bugle boy and globe, Mullard, RCA cleartop, EH Russians—then tried 12BH7s. Among those, RCA long black plate was best, with a clear, analytical, extended sound. So I got the Chinese adapter and tried a Sylvania brown-base 6SN7GT. The sound came alive for the first time. Dynamic, involving. Then the Tung Sol 5998 (actually a Chatham 2399) arrived, which I liked a lot. More air, bigger soundstage, easier, more fun. But it didn't love the Sylvania. So I tried all the input tubes again. The 12AU7s were okay (the cleartop sounded nice, but very midrangey and rolled), the RCA 12BH7, again, offered an incredibly detailed and wide-band sound, but a little cold and uninvolving. So today I tried a Raytheon VT-321. Some of the best sound I've ever heard, anywhere, anytime. Burnished, dynamic, intense detail, cavernous acoustic, and so engaging. A sound so compelling it's almost mysterious. All kinds of reverberant cues are audible—singers breathing, people moving—and there's a palpable sensation of air compressing in the microphone. Details like the spittiness of a trumpet or the wood of a drum rim are now completely audible. All of this makes listening fun rather than just impressive in an audiophile kind of way. Was going to try a Tung Sol round-plate 6SN7 but no desire to mess around with the amp anymore. The improvement from stock is simply amazing. 
   
  Now if I could only figure out how to decrease the gain a little. Turning down the digital volume control in Audirvana is probably not a great idea. Oy.


----------



## EraserXIV

Nice, thanks for the impressions. I've been looking to roll my input tube for a while but can't seem to decide which direction I want to go. Was going to go for the Telefunken but the 6SN7's seem pretty interesting. How did the Tele pair with the 5998?


----------



## liamstrain

Quote: 





silverhead said:


> I wish I knew how to take it apart.. But I think it's glued together.  Otherwise I'd fix the connection mix up.


 
   
  Try warming it up a bit - depending on the type of glue used, you might get enough flexibility to crack it open.


----------



## Cryok95

Finally managed to get my speedball and other upgrades soldered in today. 

It sounds amazing. Really can't believe the details. Gonna roll a RCA 12bh7 black plate tomorrow 

Pics to come


----------



## skeptic

mink70 said:


> I've owned a Crack that I bought from a fellow Head-Fier for several weeks, and I have to say that my initial impression with the HD800 and HD650 was not great. Compared to my JDS Labs  portable C421 op-amp powered unit (about $170), the Crack sounded bassy, rolled off on top, slow and lacking in detail—poky and boring. This was with a Sylvania 12BH7 driving a Tung Sol 6080. What I've discovered since is that the Crack is more responsive to tube rolling than any piece of equipment I've ever heard. Which is to say, unbelievably so.
> 
> Since then: I tried plenty of 12AU7s—Telefunken (my fave), Amperex bugle boy and globe, Mullard, RCA cleartop, EH Russians—then tried 12BH7s. Among those, RCA long black plate was best, with a clear, analytical, extended sound. So I got the Chinese adapter and tried a Sylvania brown-base 6SN7GT. The sound came alive for the first time. Dynamic, involving. Then the Tung Sol 5998 (actually a Chatham 2399) arrived, which I liked a lot. More air, bigger soundstage, easier, more fun. But it didn't love the Sylvania. So I tried all the input tubes again. The 12AU7s were okay (the cleartop sounded nice, but very midrangey and rolled), the RCA 12BH7, again, offered an incredibly detailed and wide-band sound, but a little cold and uninvolving. So today I tried a Raytheon VT-321. Some of the best sound I've ever heard, anywhere, anytime. Burnished, dynamic, intense detail, cavernous acoustic, and so engaging. A sound so compelling it's almost mysterious. All kinds of reverberant cues are audible—singers breathing, people moving—and there's a palpable sensation of air compressing in the microphone. Details like the spittiness of a trumpet or the wood of a drum rim are now completely audible. All of this makes listening fun rather than just impressive in an audiophile kind of way. Was going to try a Tung Sol round-plate 6SN7 but no desire to mess around with the amp anymore. The improvement from stock is simply amazing.
> 
> Now if I could only figure out how to decrease the gain a little. Turning down the digital volume control in Audirvana is probably not a great idea. Oy.




Thanks for the impressions on the raytheon tube. That's one I've always wanted to try and just may have to pick one up now. 

As far as reducing the volume (aka padding the pot), take a look at www.goldpt.com/mods.html


----------



## dsound

+1.  The Crack definitely responds well to tube upgrades.  My tube-rolling path went from stock (Sylvania 6080) >RCA 6AS7G>Chatham 5998.  
   
  The RCA 6AS7G produces such a wonderful musical experience.  Very laid-back and relaxing.
   
  In my limited experience with the 5998's, they retain the musicality of the RCA's and add a sparkle to the highs that are really engaging.  Also, the bottom end seems to gain additional tightness and detail.
   
  My only regret is that I didn't get into this hobby 2 years ago.. when 5998's were much cheaper.. my wallet hurts.
   


Spoiler: Spoiler



 
  Quote: 





mink70 said:


> I've owned a Crack that I bought from a fellow Head-Fier for several weeks, and I have to say that my initial impression with the HD800 and HD650 was not great. Compared to my JDS Labs  portable C421 op-amp powered unit (about $170), the Crack sounded bassy, rolled off on top, slow and lacking in detail—poky and boring. This was with a Sylvania 12BH7 driving a Tung Sol 6080. What I've discovered since is that the Crack is more responsive to tube rolling than any piece of equipment I've ever heard. Which is to say, unbelievably so.
> 
> Since then: I tried plenty of 12AU7s—Telefunken (my fave), Amperex bugle boy and globe, Mullard, RCA cleartop, EH Russians—then tried 12BH7s. Among those, RCA long black plate was best, with a clear, analytical, extended sound. So I got the Chinese adapter and tried a Sylvania brown-base 6SN7GT. The sound came alive for the first time. Dynamic, involving. Then the Tung Sol 5998 (actually a Chatham 2399) arrived, which I liked a lot. More air, bigger soundstage, easier, more fun. But it didn't love the Sylvania. So I tried all the input tubes again. The 12AU7s were okay (the cleartop sounded nice, but very midrangey and rolled), the RCA 12BH7, again, offered an incredibly detailed and wide-band sound, but a little cold and uninvolving. So today I tried a Raytheon VT-321. Some of the best sound I've ever heard, anywhere, anytime. Burnished, dynamic, intense detail, cavernous acoustic, and so engaging. A sound so compelling it's almost mysterious. All kinds of reverberant cues are audible—singers breathing, people moving—and there's a palpable sensation of air compressing in the microphone. Details like the spittiness of a trumpet or the wood of a drum rim are now completely audible. All of this makes listening fun rather than just impressive in an audiophile kind of way. Was going to try a Tung Sol round-plate 6SN7 but no desire to mess around with the amp anymore. The improvement from stock is simply amazing.
> 
> Now if I could only figure out how to decrease the gain a little. Turning down the digital volume control in Audirvana is probably not a great idea. Oy.


----------



## mikek200

Quote: 





silverhead said:


> My 6SN7 to 12AU7 adapter(s) showed up from China finally.   The first one (nice, gold looking one) doesn't work.   The second one that showed up does work, however.
> 
> Do you run the risk of toasting the transformer by using this setup with no other modifications?
> 
> ...


 
   
  Do you happen to have the link,to the second adapter,or,maybe the exact name.
  Unfortunately,I ordered the first one...might need a backup
   
  Great post-thank you,excellent info.
   
  Mike


----------



## silverhead

Here's the link to the auction.  Multiple are available.  This is also the best price I found:
   
http://www.ebay.com/itm/320659633166


----------



## Utopia

I'm getting interested in trying to build one of these for my Beyerdynamic T1s, but I'm wondering it the Crack is perhaps a little bit too bright for those? As I've understood it, it's not quite as warm-sounding as the Woo amps or Darkvoice/La Figaro, and the T1 can definitely use some added warmth. Has anyone tried that combination?


----------



## TheKillerPiglet

Quote: 





utopia said:


> I'm getting interested in trying to build one of these for my Beyerdynamic T1s, but I'm wondering it the Crack is perhaps a little bit too bright for those? As I've understood it, it's not quite as warm-sounding as the Woo amps or Darkvoice/La Figaro, and the T1 can definitely use some added warmth. Has anyone tried that combination?


 
  Yes, it is a top notch combo. Not bright at ll, gives the T1 some much needed body without sacrificing precision. I really enjoy it with the humble RCA 6AS7G and 12bh7 tubes. This is a very warm combination. The Crack can easily sound warmer than the 339 (which I also own) while the 339 can easily sound sharper than the Crack. Much depends on the tubes.
   
  I have tried countless tube combinations in both amps, including 6sn7's in the Crack and EF80 types in the 339. They are both highly enjoyable amps. I do not think you can go wrong.
   
  A couple of things to keep in mind:
   
  - if you are planning on picking up HE500's then the 339 is your choice. It drives them nicely, listening to this combo right now (RCA Red 6sj7's, Sylvania 6080WC's in amp, Bugle Boy 6992's pinched waist in DAC).
   
  - the 339 needs twice as many tubes, so twice as much money to roll. If you are going to stick to 600 ohm T1's, or 300 ohm Senns (the 650's are just plain seductive on these amps) then I'd go the Crack route.
   
  Another thing to keep in mind: they both share the same power tubes....
   
   
  KP


----------



## dsound

Listening to my just-completed (5minutes ago) Speedballed Crack.. Very impressed with the improvements in all frequencies.  Great job Doc!


----------



## elwappo99

Quote: 





dsound said:


> Listening to my just-completed (5minutes ago) Speedballed Crack.. Very impressed with the improvements in all frequencies.  Great job Doc!


 
   
  Congrats on the build! How about some pics?


----------



## Doc B.

Quote: 





dsound said:


> Great job Doc!


 
  Thank you. We continue to receive many Crack kit orders every day. The crew just got another good sized batch of 6080 tubes in and I believe another week or two worth of orders will begin packing today and shipping very soon.


----------



## dsound

Quote: 





elwappo99 said:


> Congrats on the build! How about some pics?


 
   
  Sure 
	

	
	
		
		

		
			





 (go Bruins).  Please excuse the rats-nest of wires.
   
  Does anyone know if there's is there a burn-in period for the Speedball?


----------



## liamstrain

They are solid state components. So, there should be no audible change over time (until failure).


----------



## Utopia

Quote: 





thekillerpiglet said:


> Yes, it is a top notch combo. Not bright at ll, gives the T1 some much needed body without sacrificing precision. I really enjoy it with the humble RCA 6AS7G and 12bh7 tubes. This is a very warm combination. The Crack can easily sound warmer than the 339 (which I also own) while the 339 can easily sound sharper than the Crack. Much depends on the tubes.
> 
> I have tried countless tube combinations in both amps, including 6sn7's in the Crack and EF80 types in the 339. They are both highly enjoyable amps. I do not think you can go wrong.
> 
> ...


 
   
  Thanks for that, KP! Very encouraging to hear.


----------



## dsound

Quote: 





liamstrain said:


> They are solid state components. So, there should be no audible change over time (until failure).


 
   
  Thanks Liamstrain.  Looks like it's a nice day to stay inside in Chicago and listen to the Crack (38degrees F last I checked)


----------



## elwappo99

Quote: 





dsound said:


> Sure
> 
> 
> 
> ...


 
   
  Looking good! This kit is on my list of amps to try out before I finally settle. I heard it once with a pair of HD650s and I looked at the owner and said "How much did this cost???" I couldn't believe it.


----------



## amcananey

Quote: 





mink70 said:


> Now if I could only figure out how to decrease the gain a little. Turning down the digital volume control in Audirvana is probably not a great idea. Oy.


 
   
  Simple. Try these. They work incredibly well and are (obviously) removable, so better than other most other solutions. While lower levels of attenuation are available, even -12dB isn't as much as you think. I would say you should go straight for the -12dB. Anything lower won't be worth your time.
   
  FWIW, they are too long and thin to work well in the verticle orientation required by the Crack's default RCA inputs, so I would get a pair of these, too.
   
  Best regards,
  Adam


----------



## ben_r_

Quote: 





amcananey said:


> Simple. Try these. They work incredibly well and are (obviously) removable, so better than other most other solutions. While lower levels of attenuation are available, even -12dB isn't as much as you think. I would say you should go straight for the -12dB. Anything lower won't be worth your time.
> 
> FWIW, they are too long and thin to work well in the verticle orientation required by the Crack's default RCA inputs, so I would get a pair of these, too.
> 
> ...


 

 Exactly what I do and use. And yes, -12dB is very subtle.


----------



## j123my

Do you guys feel the Harrison attenuators are too long? I looked at the pics (the one with Schiit DAC) and boy it is really long! I don't think it is gonna fit my setup - I don't have much space behind the DAC, and putting it on the crack side might not work too (even with the L adapter).
   
  I am currently using this, asked the seller for 300 ohms. It cuts the signal a bit just before the headphone, and you might also be able to use lower impedance cans with the crack (YMMV, never tried it). If your aim is to cut the signal, get the highest resistance just like with the Harrisons, lower ones won't do much.


----------



## Draygonn

j123my said:


> Do you guys feel the Harrison attenuators are too long?


I put the Harrison attenuators between 2 RCA cables so they don't stick out of the top of the Crack.


----------



## silverhead

Apparently with the 12AU7 to 6SN7 there is a difference between the 6.3V and 12V version of the adapters.   The ebay seller told me that the one I have that doesn't work is wired for 12V and that I need the 6.3V version.
   
  I have no idea if this is true or not, but I wanted to relay the info here for anyone concerned.


----------



## BmWr75

Hmmmm......here's the link to the exact adapter I purchased.  It does mention in the ad a 6.3V version and a 12V version.  There is then a link to the 12V version.
   
http://www.ebay.com/itm/300854844401?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649


----------



## telecaster

Is the transformer upgraded in the crack? When reading the begining of this thread Doc mentionned the transformer is ran at its limit and that the extra power requierement of the 6SN7 may be too much that is why the Crack doesn't have an octal socket in the first place.


----------



## silverhead

Quote: 





bmwr75 said:


> Hmmmm......here's the link to the exact adapter I purchased.  It does mention in the ad a 6.3V version and a 12V version.  There is then a link to the 12V version.
> 
> http://www.ebay.com/itm/300854844401?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649


 
  Is yours working in the Bottlehead?
   
  I got mine from the same seller and mine is the 12v version.   They're offering to send me another.


----------



## BmWr75

Quote: 





telecaster said:


> Is the transformer upgraded in the crack? When reading the begining of this thread Doc mentionned the transformer is ran at its limit and that the extra power requierement of the 6SN7 may be too much that is why the Crack doesn't have an octal socket in the first place.


 
   
   
 Here is what Doc said specifically about 4 weeks ago.
  
 http://www.head-fi.org/t/476650/crack-bottlehead-otl/1680#post_9308197


----------



## BmWr75

Quote: 





silverhead said:


> Is yours working in the Bottlehead?
> 
> I got mine from the same seller and mine is the 12v version.   They're offering to send me another.


 
   
  Yes, mine is installed and works fine in the Crack.  Have been using it ever since it arrived.
   
  On the 6.3v vs, 12v issue, I am not sure why they make two versions.  The 6SN7 requires a 6.3v heater voltage, have no idea how a 12v heater voltage would work with a 6SN7 tube.


----------



## audiojun

Going to join the crack and speed addicts club in maybe 2 weeks. that kit does take a long time to ship.


----------



## ben_r_

Quote: 





audiojun said:


> Going to join the crack and speed addicts club in maybe 2 weeks. that kit does take a long time to ship.


 

 When did you place your order? It typically takes a ridiculous 6 weeks to get it. They are always behind schedule.


----------



## bahorn

I placed my order for a Crack on April 3 and am receiving it today.  So it is taking about 4 weeks to get mine.


----------



## audiojun

I placed my order on april 1st and still havent shipped i don't know how you are receiving yours first because on the delievering status page they only shipped orders up to 3/22. 





bahorn said:


> I placed my order for a Crack on April 3 and am receiving it today.  So it is taking about 4 weeks to get mine.


----------



## Doc B.

We ship kits just as soon as the parts to kit them up arrive. Some customers order kits with the Speedball upgrade. Right now those kits are shipping slightly behind kits ordered without the upgrade because we are waiting for parts for the Speedball kits, which should be here later in the week. In some cases there may be differences in delivery based upon the carrier used as well.
   
  We use small local companies to make the chassis panels, the wood bases, the transformers, the PC boards and a few other components. The kits are also designed with parts that are suitable for 20th century style point to point wiring in this 21st century where everything is made to be surface mounted. Because of these factors parts can be difficult to keep in steady supply.
   
  The old saying is "good, fast, cheap - you can only have two of the three". We choose high quality at a budget price as our two priorities.


----------



## bahorn

I haven't ordered the Speedball upgrade -- yet.  From everything I have read, and assuming I can get through the Crack build (I'm not a DIYer), then I'll likely order the Speedball at some point in the future.


----------



## audiojun

Alright Doc B. it is understandable I prefer good and cheap too. I ordered my kit with speedball.


----------



## Draygonn




----------



## btrancho

Quote: 





draygonn said:


>


 
  +1


----------



## Doc B.

Thanks guys. We've been doing it this way for about 17 or 18 years now. Thankfully we have a lot of patient customers!


----------



## bahorn

Quote: 





doc b. said:


> Thanks guys. We've been doing it this way for about 17 or 18 years now. Thankfully we have a lot of patient customers!


 
  Thanks Doc B!  My Crack just arrived today.  I was hoping to get it by mid-May.  So you exceeded my expectations.  I'm now looking forward to building and listening to it.


----------



## EraserXIV

Swapped out the stock EH 12AU7 for a Telefunken, really liking what I'm hearing so far. Complements the HD650 very well by bringing out more air and details. It's also dead silent with no microphonics, the EH was terrible in that regard. Pretty much had to hold my breath every time I walked past the Crack.


----------



## dsound

Quote: 





eraserxiv said:


> Swapped out the stock EH 12AU7 for a Telefunken, really liking what I'm hearing so far. Complements the HD650 very well by bringing out more air and details. It's also dead silent with no microphonics, the EH was terrible in that regard. Pretty much had to hold my breath every time I walked past the Crack.


 
   
  Glad your enjoying the Telefunken.  I'm currently having microphonic issues with my RCA 6as7g.  But on the plus side.. my RCA 12BH7 is finally burned in and sounds great.


----------



## audiojun

My crack came in today!


----------



## dsound

Quote: 





audiojun said:


> My crack came in today!


 
  Have fun building!! Measure>Cut>Strip>Attach>Solder


----------



## elwappo99

Quote: 





dsound said:


> Have fun building!! Measure>Cut>Strip>Attach>Solder


 
   
   Measure>Measure>Cut>Strip>Attach>Solder
   
  Fixed! 
   
  At some point I hope I can build one of these  My headphone inventory just doesn't match the high impedance of the amp though :/


----------



## Jmstrmbn

For those of you who have the speedball upgrade installed, how big of an impact did it make compared to the stock kit?


----------



## Beefy

Quote: 





jmstrmbn said:


> For those of you who have the speedball upgrade installed, how big of an impact did it make compared to the stock kit?


 
   
  Big. It is the single best upgrade IMHO, and money is better spent on Speedball than tube rolling, output caps, magical crystals, etc.


----------



## Jmstrmbn

That's good to hear, I should be ordering one in the next week or two.


----------



## dsound

+1 Big Impact.  The sound out of the Crack is more engaging with the Speedball.  IMO there is some tradeoff though, I loved the laid-back sound of the stock Crack and some of that is gone with the addition of the Crack.  
   
  I am currently listening to "Nojima Plays Liszt" out of my Crack + Speedball + 7236 Tube and the piano is presented beautifully.
   
   
  Quote: 





jmstrmbn said:


> For those of you who have the speedball upgrade installed, how big of an impact did it make compared to the stock kit?


----------



## dsound

Hehe, you're right.. It's a good thing they give you more than enough wire with the Crack kit 
	

	
	
		
		

		
			




   
  I thought I saw some others report that your T1 pairs nicely with the Crack (just sayin')... 
   
   
  Quote: 





elwappo99 said:


> Measure>Measure>Cut>Strip>Attach>Solder
> 
> Fixed!
> 
> At some point I hope I can build one of these  My headphone inventory just doesn't match the high impedance of the amp though :/


----------



## crayonz

Hi,

Just used the crack + speedball with gec 6as7g brown base and telefunken smooth plate.

The sounds is above my expectation 

Pairing with hd 800, i also surprise for the incredible bass sound


----------



## mikek200

Congradulations...
   
  I'm waiting on my Gec's to come in,also using the HD800's,will pair them with the Siemens silver plates
   
  Any more impressions you'd like to share will be welcome.
   
  Mike


----------



## Cryok95

I tried the telefunken 12au7. It's good but overpriced IMO. I bought a bugle boy and preferred it over the telefunken. Telefunken may be more refined and neutral but the bugle boy brings out the 'fun' in the music. The bass on the bugle boys are not to be trifled with. It has all the 'Oomph' that I love.


----------



## EraserXIV

Like most NOS tubes these days it is over priced, but if you can get one for around $30 I think it's worth it. Like all things, it depends on your system. I got it to bring out more air and detail in the darker sounding HD650. I'm not sure it would be the 12AU7 I would reach for though if I was listening to a DT880 for example.
   
  I'm pretty intrigued by the new production Psvane 12AU7, at $65 it's not the cheapest (but also not the most expensive), and reviews have been very interesting.


----------



## mikek200

Quote: 





eraserxiv said:


> Like most NOS tubes these days it is over priced, but if you can get one for around $30 I think it's worth it. Like all things, it depends on your system. I got it to bring out more air and detail in the darker sounding HD650. I'm not sure it would be the 12AU7 I would reach for though if I was listening to a DT880 for example.
> 
> I'm pretty intrigued by the new production Psvane 12AU7, at $65 it's not the cheapest (but also not the most expensive), and reviews have been very interesting.


 
  i just ordered one of those,wasn't sure if I should get the Sophie's or the Psvane,?..$65.00 is not so bad.
  If I told you what I paid for one GEC??..
  Anxious to get the psvanes,,a few guys had high praise for them.


----------



## EraserXIV

mikek200 said:


> i just ordered one of those,wasn't sure if I should get the Sophie's or the Psvane,?..$65.00 is not so bad.
> If I told you what I paid for one GEC??..
> Anxious to get the psvanes,,a few guys had high praise for them.




Awesome, keep us updated. I may just purchase one too.


----------



## Cryok95

If you could get a bugle boy(made in holland) for $15 or less I would say go for it. 

It's in my opinion the best or one of the best 12au7. I have tried RCA clear tops and Mazda 12au7s but always kept coming back to the bugle boy. 

Now... To try 6sn7s. I have an adapter coming in soon and some 6sn7gt's from eBay. I'm crossing my fingers now and hoping for the best.


----------



## mikek200

Getting a BB for $15.00 isn't a sale --it's a gift...buy all you kind find.
   
  I have a set ,which I paid $59.00,recently
  I've used the BB's on my lyr,& now on my crack..a wonderful tube
   
  "Awesome, keep us updated. I may just purchase one too."
   
Will do..if I ever get them--they are coming in from England..so could take some time.


----------



## skeptic

My bugle boy is my favorite 12au7 with my hd800's, but I think I actually prefer my cheapie rca clear top with my hd650s. They don't need the warmth of the amperex tube like the hd800s, and the rca makes their trebles sound a little more extended.

With the speedball in place though, I tend to favor 12bh7's across the board. I scored a flawless 1959 tung sol for < $20 a couple years back that has been my go to ever since. RCA black and grey plates are also quite nice and a little fuller sounding than the 12au7's I own. 

I finally ordered a 6sn7 adaptor this week. Anyone have any comments on some relatively affordable tubes of this type that I should try? I've been eyeing some mouse ears, possibly a raytheon or sylvania vt231, and I would also love to try a bad boy if I can find one at a reasonable price.


----------



## Ultrainferno

I just discovered I left my crack turned on for the last 4 days without being home. Problematic?


----------



## Beefy

Quote: 





ultrainferno said:


> I just discovered I left my crack turned on for the last 4 days without being home. Problematic?


 
   
  Whoa dude! At a power draw of ~35W, and 96 hr, and 15c/kW/hr, that would have cost you 50 cents!!!!!!!!!111
   
  No, its perfectly fine.


----------



## 2359glenn

Quote: 





ultrainferno said:


> I just discovered I left my crack turned on for the last 4 days without being home. Problematic?


 
  That should be no problem in the past tube equipment was on 24/7
  When I build a new amp I leave it on 24/7 for a week before I ship it.


----------



## Ultrainferno

Quote: 





2359glenn said:


> That should be no problem in the past tube equipment was on 24/7
> When I build a new amp I leave it on 24/7 for a week before I ship it.


 
   
  Quote: 





beefy said:


> No, its perfectly fine.


----------



## TheKillerPiglet

Quote: 





ultrainferno said:


> I just discovered I left my crack turned on for the last 4 days without being home. Problematic?


 
   

 Doubt it, tubes are made to run 24/7. My DAC has been on 24/7 the last 8 years. As long as the transformer can take it and there are no cold solder joints.
   
  KP


----------



## Beefy

Quote: 





thekillerpiglet said:


> Doubt it, tubes are made to run 24/7. My DAC has been on 24/7 the last 8 years. As long as the transformer can take it and there are no cold solder joints.
> 
> KP


 
   
  Well see, I joked about the power usage for the Crack above...... but leaving something on like that is just insanely and unnecessarily wasteful.
  
  It is something like 70,000 hours, which is *definitely* a drain on tube function, but also passive components like capacitors. Not to mention a minimum of $100 in electricity charges assuming just a 10W draw..


----------



## TheKillerPiglet

Quote: 





beefy said:


> Well see, I joked about the power usage for the Crack above...... but leaving something on like that is just insanely and unnecessarily wasteful.
> 
> It is something like 70,000 hours, which is *definitely* a drain on tube function, but also passive components like capacitors. Not to mention a minimum of $100 in electricity charges assuming just a 10W draw..


 
  This the recommended use of the DAC, power cycling puts greater strain on the tubes that leaving it on. The only casualty so far has been a rectifier tube going after 7 years, although the other tubes do get rolled. I would not do this with a power amp, though. Having said that, I've left the big tube monoblocks on for 3-4 days running over long weekends.
   
  KP


----------



## Beefy

Quote: 





thekillerpiglet said:


> This the recommended use of the DAC, power cycling puts greater strain on the tubes that leaving it on.


 
   
  Complete and utter audiophool rubbish.


----------



## TheKillerPiglet

Quote: 





beefy said:


> Complete and utter audiophool rubbish.


 

 Thank you for playing, do pickup a parting gift.
   
  KP


----------



## btrancho

The folks at Bottlehead recommend that you shut down the Crack if it isn't going to be used within 2 hours.  I'd take their recommendation over most others.


----------



## Beefy

Quote: 





thekillerpiglet said:


> Thank you for playing, do pickup a parting gift.


 
   
  Please, tell us all exactly what "strains" in a tube during power cycling. I'm sure we'd all love to hear your explanation of what imaginary effect is worse than other very-real-and-well-characterised degradation effects.


----------



## BmWr75

Quote: 





beefy said:


> Complete and utter audiophool rubbish.


 
   
  +1 on that.


----------



## Doc B.

I don't recall having said shut it down if it isn't going to be used in 2 hours. Maybe one of the other guys here did. My take on this is that tubes are kind of like incandescent light bulbs (does anybody use those anymore?), but not exactly. There is a limit to the lifetime but it is typically much longer lifetime than an incandescent light filament. The cathode (filaments or cathode heated by a heater) gradually loses its ability to emit electrons with use. Like a light bulb, power cycling the tube heater or filament probably does create some potential stress from the thermal change. But generally a filament or heater break is not the way a tube dies. More often the cathode runs out of emissive material. So it's probably better to leave tubes off if you don't plan to use them for a while.  
   
  The other side of the coin here is that a tube needs to heat up for a while to sound its best. So my suggestion is to turn the amp on for a while, like 20 minutes to an hour before you do any critical listening. And shut the amp off when you know you are finished with it for the day.


----------



## mikek200

I posted this on the buy/sell forum,just in case,someone here might be interested:
   
     http://www.head-fi.org/t/664605/bottlehead-crack-amp-w-speedball-upgrade
   
  Please PM me if interested
   
  Thanks
  Mike


----------



## EraserXIV

Getting a mainline?


----------



## MrEleventy

it's the wait time for a bottle head crack still about 4 weeks? what about with the speed ball? thx.


----------



## mikek200

Quote: 





eraserxiv said:


> Getting a mainline?


 
  LOL,Gee,what gave you that idea???


----------



## Doc B.

mreleventy said:


> it's the wait time for a bottle head crack still about 4 weeks? what about with the speed ball? thx.




Right now the wait is estimated at about 2 weeks. We are awaiting some power transformers before the next batch can pack. They may arrive some time next week.


----------



## ffivaz

I just finished my BH Crack a week ago. I didn't have any problems with building it, even if it was my first DIY project (except a non-working 6080 tube that I replaced). The guys at BH really helped me sort out the problem (thanks Doc). It sounds really good with my HD 650 and my 600 Ohms Revox RH 310 (reviewed here). And I just can wait to start rolling tubes, and maybe some day go for the Speedball !
   
  Here are some pictures.
   
​   
​  ​


----------



## dsound

Congrats on your build, looks great!
   
  On another note, I am ashamed to admit that I incorrectly attributed noise from my Crack to the amp.  After inspecting + reflowing the connections, it turned out to be noise from the Line-out of my iPod..
   
  Moral of the story:  The Crack is dead-silent and shorting-plugs are awesome for diagnosing noise-issues.
   

   
   
  Quote: 





ffivaz said:


> Spoiler: Warning%3A%20Spoiler!
> 
> 
> 
> ...


----------



## EraserXIV

Yeah I had a similar issue. I was hearing some noise that I didn't hear before and I thought something had gone wrong with my Crack. I inspected it, resoldered joints, the whole 9 yards. Turns out it was the Wifi antenna from my computer causing interference, I just needed to move the antenna to another position and the Crack was back to being dead silent.


----------



## uzi

For me, it was a baby monitor.  That, and some noisy tubes.


----------



## tdogzthmn

Curious is any Crack owners have the K240DF on hand.  I sold my Crack before I got this headphone which sounds great on my SEX but I would have liked to try it with the Crack which is more suited to the 600 ohm load.  Anyone who's looking for a neutral headphone should look into picking one up!


----------



## Armaegis

Not the DF, but the Crack + K240 Sextett was one of my favourite combos ever.


----------



## FlySweep

Speedball'ed Crack (with Alps RK pot & Erse X-Pulse output cap upgrades) just arrived.  Lovingly built by Jeremy (j23my).
   
  Running Tung-Sol 5998, a NOS Tungsram 12AU7 & using a Bottlehead power cord.  Only been listening for a short period of time.. I love it so far.. terrific match with the Fischer Audio FA-002w "High Edition" (pictured) & the HD800.  Feeding it with an ODAC.  Smooth, dynamic, clean, airy, very transparent, with just a touch of liquidity.  Impressive.


----------



## mikek200

Great pic...
  Those Fischers' look great as well,may I ask where you got them??
   
  I've been using the same setup,with my HD800's.
  Recently,I got a 12au7 tung-sol blackplate tube,and ,they are outstanding..might want to give them a shot
  j23my,sold me my first crack


----------



## liamstrain

Quote: 





armaegis said:


> Not the DF, but the Crack + K240 Sextett was one of my favourite combos ever.


 
   
  Aye. Great with my MP sextetts, as well as my later 240 monitors. Killer mids.


----------



## FlySweep

> Originally Posted by *mikek200* /img/forum/go_quote.gif
> 
> Great pic...
> Those Fischers' look great as well,may I ask where you got them??
> ...


 
   
  Thanks.. I bought the High Edition from MusicaAcoustics.  Dimitri's got a few left at very good prices.  Fischer Audio's opened up a reliable store that ships worldwide, as well.  They've released the Ti (which is an updated 003).. but it's got much lower impedance (64 ohms) than the HE (~200 ohms), so the High Edition is better suited to be driven off tube amps (with typically high OI).  Plus, I bet the HE is still better than the Ti.


----------



## FlySweep

> Originally Posted by *mikek200* /img/forum/go_quote.gif
> 
> Recently,I got a 12au7 tung-sol blackplate tube,and ,they are outstanding..might want to give them a shot
> j23my,sold me my first crack


 
   
  Oh, and thanks for the tube recco.. I was looking at the Tung Sol reissue (being made by New Sensor corp) as another low-budget tube.. heard it sounds pretty good.. but I've read that Black Plates you mentioned are the best of the Tung Sols.  Will look into those.  Just got a Mazda '"CIFTE" 12AU7 tonight, too.  Another nice tube.  Excellent soundstage.. reminds me a bit of the USA-made Amperex "white-label" PQ 6922 tube (which might be my favorite 6922/6DJ8 tube).  WIll give it some time to break in, though.
   
  Jeremy's been great to work with.. excellent communication & his BH builds are _impeccably_ clean.


----------



## crayonz

Hi i want to sharing due to surprisingly the gec 6as7 (with gec sticker) and gec 6as7 (cv 2523 printed on the tube and without gec sticker)sounds different. The 1st tube is sound more solid state while the 2nd tube is sound more warm and have an excellent mid low.

Both tube has a brown base tube..


----------



## crayonz

flysweep said:


> Speedball'ed Crack (with Alps RK pot & Erse X-Pulse output cap upgrades) just arrived.  Lovingly built by Jeremy (j23my).
> 
> Running Tung-Sol 5998, a NOS Tungsram 12AU7 & using a Bottlehead power cord.  Only been listening for a short period of time.. I love it so far.. terrific match with the Fischer Audio FA-002w "High Edition" (pictured) & the HD800.  Feeding it with an ODAC.  Smooth, dynamic,
> clean, airy, very transparent, with just a touch of liquidity.  Impressive.



Fantastic


----------



## mikek200

Quote: 





flysweep said:


> Thanks.. I bought the High Edition from MusicaAcoustics.  Dimitri's got a few left at very good prices.  Fischer Audio's opened up a reliable store that ships worldwide, as well.  They've released the Ti (which is an updated 003).. but it's got much lower impedance (64 ohms) than the HE (~200 ohms), so the High Edition is better suited to be driven off tube amps (with typically high OI).  Plus, I bet the HE is still better than the Ti.


 
  Thanks Fly,
  Are you having any issues driving this headphone with the Crack??
  Are those Tung-sol re-issues ,made in Russia?
  After many e-mails to a few sellers,including my favorite,Brent Jesse..the blackPlates are the ones to get...the greyplates,have a different SQ..in there opinion.
  I was so impressed with the Blackplates,with the GEC tube,I bought 6 pairs....,a previous customer of Brent, bought 15 pairs..
  If you find any-jump on it..think you'll love em
   
  Mike


----------



## crayonz

Hi mike





mikek200 said:


> Thanks Fly,
> Are you having any issues driving this headphone with the Crack??
> Are those Tung-sol re-issues ,made in Russia?
> After many e-mails to a few sellers,including my favorite,Brent Jesse..the blackPlates are the ones to get...the greyplates,have a different SQ..in there opinion.
> ...




Hi mike, may i know the price for the tungsol?

Tx


----------



## crayonz

Hi mike





mikek200 said:


> Thanks Fly,
> Are you having any issues driving this headphone with the Crack??
> Are those Tung-sol re-issues ,made in Russia?
> After many e-mails to a few sellers,including my favorite,Brent Jesse..the blackPlates are the ones to get...the greyplates,have a different SQ..in there opinion.
> ...




Hi mike, may i know the price for the tungsol?

Tx


----------



## mikek200

They varied in price..
  The matched pair I got from Brent Jesse were ..$115.00 ..they are NOS


----------



## audiojun

Installed speedball last night. It was late and I stayed up till 3am listening to music. The music was so good that I had tears in my eyes. noticed faster attack, a lot more micro details, better instrument seperation and soundstage. better than the stock crack in everyway.


----------



## dsound

Congrats!  I've been enjoying mine for a while now and it's a worthwhile upgrade. 
   
  One interesting note; once I installed the Speedball, I also purchased a RCA 12bh7 because I heard great things about it.  While I did enjoy the increased treble detail of the 12bh7, I felt like it made the Crack less musical/lush when compared to the RCA 12au7.  All ears are different I guess


----------



## commtrd

How does the Crack / Speedball drive the Audeze LCD2.2 and 3 phones?


----------



## audiojun

the damping factor would be too low because crack has an high output impedance. it will sound loose and distorted. high impedance amp into low impedance headphones is a no. The sex kit and mainline kit would be great though.


commtrd said:


> How does the Crack / Speedball drive the Audeze LCD2.2 and 3 phones?


----------



## SoupRKnowva

Quote: 





audiojun said:


> the damping factor would be too low because crack has an high output impedance. it will sound loose and distorted. high impedance amp into low impedance headphones is a no. The sex kit and mainline kit would be great though.


 
  High output impedance doesnt really do anything to orthos since orthos dont really have electrical dampening like a standard dynamic driver. they are mostly damped by the air and other dampening materials on the earphones. The crack just wouldnt put out enough power into that load though to make the orthos sing, its not designed for it is all.


----------



## Armaegis

The output impedance doesn't have an effect on frequency response since ortho impedance is essentially flat/resistive.
   
  Damping factor is still affected. That said, the audible difference is *tiny*. I've A/B'd directly between two identical amps with the only difference being an output resistor to change the output impedance. I could only tell the difference by listening to a very specific passage repeatedly and immediately switching between the headphones. There's no way I'd be able to tell them apart under normal circumstances. 
   
  Which is all moot, since the LCD2 doesn't sound very good on the Crack anyways 
	

	
	
		
		

		
		
	


	




 Well, it doesn't sound bad (at low volumes), but I've heard better.


----------



## Dark Helmet

I just got my Crack with Speedball mod up and running into my new HD 600.  Wow!  I was running an O2 into DT770's and I really dug that, but this is in another league.  Pure tube goodness.
   
  Any other easy mods for further enhancements on this unit that isn't going to break the bank?


----------



## ffivaz

dark helmet said:


> I just got my Crack with Speedball mod up and running into my new HD 600.  Wow!  I was running an O2 into DT770's and I really dug that, but this is in another league.  Pure tube goodness.
> 
> Any other easy mods for further enhancements on this unit that isn't going to break the bank?




Tube rolling! Although it could break the bank....


----------



## W0lfd0g

I am due to take arrival of my Crack in a few days (with Speedball) and this is my first crack at DIY (other than a Cmoy) and circuit modification. 

 I am thinking of going with a ClarityCap 100uf SA bypassed with a 10uf / 600V, Mundorf M-CAP Supreme for the output (in parallel).  Anyone tried this combo and can predict results?  Any words of affirmation or impassioned pleas for an immediate change of mind would be most welcome.


----------



## FlySweep

I recently got my hands on a NOS Mazda CIFTE 12AU7 (purchased here).  I took a flyer on it after seeing that this tube had quite a good rep in some of the other hifi forums.  The book on them is that they supposedly possess an Amperex-inspired low end & soundstage (punchy, dynamic bass & a deep, vibrant stage).. the famous (warm, liquid, full) "Mullard" mids w/o the thickness or slowness (that some of their tube variants possess).. and a clean, airy, open treble response.  Too good to be true?
   
  ..I rolled them into my (speedballed) Crack (w/ a Tung Sol 5998 output tube) earlier this week & listened with my full sized phones (see sig)..
   
  Initial impressions, unfortunately, yielded to that age-old adage, "if it seems to good to be true, it probably is" : Bass response was nice, but it lacked extension and dynamics.. the mids were thin and recessed.. the upper mids were edgy and treble sounded harsh and peaky.
   
  As of yesterday, I've logged around fifty hours on them, and goodness.. what a difference.   This tube's sound has smoothed out and filled in very impressively.  I'm now hearing the cause for all that praise I read about (and which, in my humble opinion, is well deserved now).  The bass is terrific.  It plays to my neutral-leaning sensibilities while offering excellent punch, texturing ability, and extension.  The Amperex comparisons are apt.  The mids.. an area that I (initially) considered the weakest part of this tube's presentation.. has morphed into its strength.  They're warm, smooth, liquid, and dynamic.. with a presentation that's decidedly airy, spacious, and open (and less thick, lush, and intimate).  The presence of an edgy upper mid & harsh treble has also subsided.  It's given way to a crisp, clean, balanced treble response that's complimentary to the midrange without ever playing 'second fiddle' to the other two-thirds of the freq. spectrum.
   
  The show stealer is the soundstage, though.  It boasts excellent proportionality (width x depth x height) and serves up an incredibly immersive space for you to "get lost in".  It isn't incredibly panoramic or breathtakingly deep.. it simply balances space extremely well and allows spatial cues to image very cleanly.  Well recorded live sets are a real treat to listen to with this tube (and the HD800, of course).
   
  If you like the sound of some of the better Amperex tubes.. but want to hear a bit of a fun twist on it (i.e. a dash of the Mullard mids and a more airy & open treble response), I can't recommend this tube enough.  The eBay buyer I bought them from (linked above) was excellent and shipping was very prompt.  The tube arrived very well packaged, too.  Hope more people take the plung on this tube, I think it's quite nice and has a mass appeal quality to it.. while being able to impress (even) the (snobbiest) audiophiles among us.


----------



## Dark Helmet

Quote: 





flysweep said:


> I recently got my hands on a NOS Mazda CIFTE 12AU7 (purchased here).  I took a flyer on it after seeing that this tube had quite a good rep in some of the other hifi forums.  The book on them is that they supposedly possess an Amperex-inspired low end & soundstage (punchy, dynamic bass & a deep, vibrant stage).. the famous (warm, liquid, full) "Mullard" mids w/o the thickness or slowness (that some of their tube variants possess).. and a clean, airy, open treble response.  Too good to be true?
> 
> ..I rolled them into my (speedballed) Crack (w/ a Tung Sol 5998 output tube) earlier this week & listened with my full sized phones (see sig)..
> 
> ...


 
  Nicely described Fly.  I'll definitely look into it.


----------



## mikek200

Selling a few Crack tubes..
  Thought some of you guys might be interested..
   
     http://www.head-fi.org/t/666426/fs-crack-tubes
  Please PM me,if you have any questions..
   
  Thanks
  Mike


----------



## FlySweep

Mikek200 was kind enough to let me audition one of his beloved Tung-Sol "black plate" 12AU7 tubes.
   
  This evening, I spent some time with it in the (SB'ed) Crack.. listening was done with the HD800.  It didn't take long, but I found this tube to sound, quite simply.. _jaw-dropping_.  I'm hearing terrific tonal purity along with eye popping transparency.  The soundstage & dynamics are nothing short spectacular.  This leads to some of the finest instrument separation & pinpoint imaging I've ever heard from a tube.  It isn't particularly liquid or even slightly warm (or lush, or dry, or thick, or lean) to my ears.. just wonderfully neutral and a bonafide "resolution monster."
   
  It does lean to the slightly brighter side of neutral since the bass appears to be very linear to my ears (midbass, in particular, is exceptionally flat) & there some emphasis in the upper mids/treble.  The midrange is impeccably clear, detailed, and transparent.  It's requires no effort to hear very deep into the 'meat' of recordings since much of the sound originates in the midrange.  The BP's upper midrange-through-treble are so clean, clear, controlled, open, and detailed.. that the precise HD800 simply serves it up for us to marvel at in all it's glory.  Normally, one would think a "bright leaning" tube would not bode well when it comes to pairing with the (already somewhat bright) HD800.. nothing could be further from the truth.  If this tube had a tendency to sound harsh, edgy, peaky, or unrefined.. even in the slightest.. the HD800 would (ruthlessly) show it.  What I'm hearing is crystalline reproduction of anything and everything that resides in this frequency region.  The lack of any grain.. anywhere in the freq. spectrum.. is astonishing.
   
  This TS BP appears to be the the proverbial 'total package' if you're looking for a very articulate, mesmerizingly-transparent, detailed sound.


----------



## skeptic

from the description, they sound a bit like the 1950's TS black plate 12bh7 that I have been running in mine, per the recommendations of a few posters on the bh forums. 

have either of you heard this tube? it would be cool to compare them back to back.


----------



## mikek200

I have a pair of them,running on my new /used Taboo II
  Comparing the matched 12au7 version from Brent Jesse,.. to the matched pair of 12BH7.....-I'd say Brents pair wins out ,by a hair.
  One thing ,I did notice,the 12BH7 seems to run a bit hotter
  Both versions are excellent,IMHO..& wish I could get more
  Brent told me that one of his clients bought 15 pairs from him...so,BP's are now on the extinction list


----------



## JmanOfIsrael

Very close to pulling the trigger on a Crack kit. Would you HIGHLY recommend the $80 power cord. Does it really make that much of a difference if I just use a regular IEC cable? I'd rather take that $80 to invest in some nice RCA cables...


----------



## Armaegis

I'd spend the money on the Speedball first.


----------



## Dark Helmet

The h $80 power cord would be the last upgrade I would make.


----------



## JmanOfIsrael

Thanks for the quick replies! I'm also looking for a good DAC to pair with the Crack and the HD650s. I'm trying to stay under $200 and I'd like it to have optical input but I will settle for USB input. I was considering the Schiit Modi but if you guys push me I might jump for the Bifrost. Any other suggestions?


----------



## FlySweep

> Originally Posted by *Armaegis* /img/forum/go_quote.gif
> 
> I'd spend the money on the Speedball first.


 


dark helmet said:


> The h $80 power cord would be the last upgrade I would make.


 
   
  ^ Agreed ^
   
  I built the BH power cord (which I'm using with my Crack).  I'll offer some thoughts on if I hear a difference in a week or so.



jmanofisrael said:


> Thanks for the quick replies! I'm also looking for a good DAC to pair with the Crack and the HD650s. I'm trying to stay under $200 and I'd like it to have optical input but I will settle for USB input. I was considering the Schiit Modi but if you guys push me I might jump for the Bifrost. Any other suggestions?


 
   
  I'm using the ODAC (~$160) with my Crack/HD800.  It only has USB input.. but I'm more than satisfied with it.  It doesn't feel/sound like a 'bottleneck' at all, BTW.  I've owned the Modi (and Magni) as well.. I liked my time with the Schiit stack & came away impressed with the M/M.. but I preferred the ODAC to the Modi (I found the ODAC's output to be cleaner.. and perhaps, slightly more resolving).


----------



## JmanOfIsrael

Thanks for the impressions! I've heard a lot of mixed reviews about the modi and odac. Some prefer the odac while others prefer the modi... I wonder if it is a personal preference?


----------



## liamstrain

You should be able to build a Gamma 1 (maybe gamma 2) for less than $200 as well. Coax and USB for the 1, optical added in for the 2. Very capable dac.


----------



## Beefy

Quote: 





jmanofisrael said:


> Very close to pulling the trigger on a Crack kit. Would you HIGHLY recommend the $80 power cord. Does it really make that much of a difference if I just use a regular IEC cable? I'd rather take that $80 to invest in some nice RCA cables...


 
   
  Cable upgrades make the skeptical scientist within me *very* twitchy. So here is a list of things I would invest in to improve my music listening experience before buying a fancy power cable:

 Speedball
 Output caps
 Volume pot
 Tubes
 A comfy chair
 Mood lighting
 A purring lap-cat
 Top-shelf alcohol
 High-class adult magazines
 ...
 ...
 75 other potentially amusing things
 ...
 ...
 
 Power cable


----------



## uzi

Quote: 





jmanofisrael said:


> Thanks for the impressions! I've heard a lot of mixed reviews about the modi and odac. Some prefer the odac while others prefer the modi... I wonder if it is a personal preference?


 
  I haven't heard the Modi, but I've compared the ODAC with the HRT MusicStreamer II and found them to be very similar with a slight (very very slight) victory in musicality to the MSII.  I've since upgraded to the MSII+ and found it to be noticeably more detailed and better sounding that its little brother.  With your budget, I'd be considering spending a slight bit more on the MSII+ or looking into the AudioQuest Dragonfly.


----------



## JmanOfIsrael

That all sounds great! I'm in the midst of purchasing an ODAC so I think I will probably stick with that. And Beefy, I'm glad you were able to confirm my scientific skepticism, even if having a cat supposedly reduces the value of our HiFi gear. And I had a good laugh, that is important too.


----------



## skeptic

Mike - thanks for the input on the two tungsol tubes! I look forward to your description of how the 12au7 black plate sounds in the mainline, as I am also on the preorder list!

Jman - I use a JDS odac in my bedside rig, and agree with the comments above that it is very nice, and sounds great with my Crack, particularly given it's minimal price tag. That said, my Keces 131 is a bit better sounding (measures better as well), and last I checked, someone had one posted in the FS forum at $165, barely more than an odac. If your preference is an spdif dac, the keces 131 is a steal at that price. The review on enjoythemusic describes the sound signature very nicely and compares it to keces' other model, the usb based 151: http://www.enjoythemusic.com/magazine/equipment/0808/keces_da151.htm

beefy - awesome and hilarious post!


----------



## JmanOfIsrael

I wasn't able to find the Keces but I just got the odac for $130 shipped which I am happy with. I think I will be able to live without SPDIF input. The way I look at it, this is going to be a huge upgrade in the first place provided I don't botch the Crack build.


----------



## mikek200

"Mike - thanks for the input on the two tungsol tubes! I look forward to your description of how the 12au7 black plate sounds in the mainline, as I am also on the preorder list!"
   
They are outstanding,IMHO ,the best tube I ever used ,with maybe an exception for the Lorenz Stuttgarts.
I leave it in ,& use it on almost all of my music now.
When I had the Lyr,I spent over $3K on tubes,{many duplicates though}..I wish I had the BP's then
Of course,this is with my Cryoed ears,HD800 ,and uber bifrost...YMMV.
   
Also,..I sold my crack-now using a Taboo II.
   
I have a spare set,of BP's,,..--PM me,if you're interested.
I bought 6 pairs-2 are matched
   
Mike


----------



## Dark Helmet

> I built the BH power cord (which I'm using with my Crack).  I'll offer some thoughts on if I hear a difference in a week or so.


 
  Where did you get the Right angle IEC?


----------



## FlySweep

> Originally Posted by *Dark Helmet* /img/forum/go_quote.gif
> 
> Where did you get the Right angle IEC?


 
   
  It came with the BH Power Cord kit.


----------



## liamstrain

Right angle IEC's are around. I got mine from Markertek (there are others) for $8. Bloody brilliant.


----------



## EraserXIV

monoprice has a 14AWG right angle IEC cord for pretty cheap


----------



## Dark Helmet

I was actually looking for just the connector as I prefer to make my own.


----------



## FlySweep

Got my hands on a Bendix 6080WB (solid graphite cross-columns) today.  This was, again, from Mikek200's stock so it's already had some use.  I dropped it into the Crack and let it burn in for about six hours before listening.  12AU7's tubes used were the: Tung-Sol "black plate," RCA/Conn "clear top," Mazda "CIFTE," and a Tungsram.
   
  The 6080 reminds me a lot of the 5998 as far as technical ability: very resolving, excellent freq bandwidth, top notch clarity & tonal accuracy, etc.  The 6080 seems even tighter in terms of control while possessing even better instrument separation, soundstage, and dynamics.  The 5998 might be (barely) more neutral in terms of freq. response & has better treble linearity; it also has more gain.. but I absolutely love how robust, musical, dynamic, and spacious the 6080 sounds.
   
  The respect the Bendix 6080WB gets for its bass performance is most definitely justified.  Bass frequencies seem quite neutral as far as tuning.. but the low-end has terrific speed, extension & impact.. without exhibiting even a hint of looseness or bloat.  Relative to the 5998's midrange, I find the 6080's midrange more liquid, rich.. and tinted with a lovely, ethereal warmth that i quite simply cannot get enough of.  The treble frequencies might be where the 5998 gets the nod.  It sounds a touch cleaner, more extended, and linear.  Even with the HD800.. I had to listen closely to discover this, though.  Make no mistake, the 6080's treble presentation doesn't disappoint in the slightest.. it's just an eighth of a step behind the 5998 as far as refinement.
   
  Overall, I find the 6080 on par with (if not slightly better than) the 5998 as far as technicalities go.. it offers a slight "change of pace" to the 5998 in terms of sound signature.  Call it "new toy" syndrome, but right now, I find myself reaching for the 6080 more than the 5998.  The wonderfully dynamic bass, buttery smooth, liquid midrange, and easy-going treble is ticking all the boxes for me.  I feel very fortunate to have both the 5998 & 6080 since both these tubes should keep me more than satisfied as far as power tube rolling for the Crack.


----------



## mikek200

Hi Fly,
  Glad you liked the 6080's.
  I too,considered it ,a go to tube..either or,to me they were close ...5998/6080
  Question:-why did let it burn in for 6 hours??..I only burned it in 30-40 minutes..am I missing something?
  Out of all those 12au7's,which one did you feel, gave you the best SQ combination?
   
  Mike


----------



## EraserXIV

Anyone have recommendations on tubes to run with the HD800? The 5998, Tele 12AU7 combo I was running with the HD650 is a bit too bright at times. I switched to the RCA 6AS7G which tamed it down, but I feel like I'm missing a layer of detail compared to the 5998. I'm thinking of keeping the 5998 in and switching around the 12AU7 to a warmer tube than the Tele. Thoughts, any suggestions?


----------



## mikek200

Might want to try one of the Mullards...many of them have a warm sound signature,with the exception of the bugleboys
  I've been using the CV491-ECC82 ,when I had the Crack.


----------



## FlySweep

> Originally Posted by *EraserXIV* /img/forum/go_quote.gif
> 
> Anyone have recommendations on tubes to run with the HD800? The 5998, Tele 12AU7 combo I was running with the HD650 is a bit too bright at times. I switched to the RCA 6AS7G which tamed it down, but I feel like I'm missing a layer of detail compared to the 5998. I'm thinking of keeping the 5998 in and switching around the 12AU7 to a warmer tube than the Tele. Thoughts, any suggestions?


 
   
  The (NOS) Tungsram 12AU7 might fit the bill.  Rolled it in tonight (after using it on and off for the past couple of weeks) and I think it's finally "matured" in terms of sound.  This tube seemed to take longer than other to break in.. OOTB (and for a good while afterwards), I found it a bit underwhelming.  Flat soundstage, grainy mids, and lacking adequate extension.
   
  Using it the last two days, this tube's shook that grain out to reveal some _really_ impressive transparency.  The eye-popping dynamics make me want to jump out of my chair and start dancing!  In fact, this tube seems like it has the best dynamics of the (small) collection I have now.  I'm digging the bold, smooth, clear sound.  The bass is simply phoenomenal.  It has excellent punch, detail, texture, and weight.  This kind of robust, low end precision reminds me of what I've heard from some of the better solid state amps.  Mids are very liquid, deep, and clean sounding...perhaps slightly warm, but I sense a lot of neutrality in terms of tonal accuracy and that liquidity keeps it very musical and engaging.  It resolves at a very high level.. and presents all those micro details in a smooth, effortless manner.  Going along with the midrange theme, the treble is airy, clean, detailed, and .. smooth.  Cymbals have realistic shimmer.. but rougher passages don't grate or sound uncomfortably rough.  I feel this tube's upper frequencies strike a really nice balance between what I (personally) prefer from treble presentations, in general.  I'm seriously impressed with the totality of this tube's presentation.
   
  I've been listening to the Tungsram tube for the better part of 12 hours (off and on).. and, amazingly, I've had no desire to roll in _any_ of my other tubes.  The Bendix 6080 is in the driver position, so this dynamic duo seems to have some awesome synergy going with it.  There's just a very smooth, substantial, spacious, focused quality to the sound that both my full sized phones are eating up.  This tube combo reminds me of the Violectric stack's sound, actually.. just more liquid, musical, and spacious.. no wonder I like it.. LOL.  I'm impressed by _how much_ it's cleaned up (since I initially rolled it in) and feel it's one of the best values going.  I'd be really interested to hear this tube with the HD650, actually.. I think you're in for a treat (and it offers a tone more than great bass).
   
  Speaking of the Bendix 6080.. I'm in love with it.. and the fact I may prefer over the 5998 is becoming a very certain reality.  The 5998 sounds, comparatively, leaner and lacks the sheer power and depth of the Bendix tube's presentation.  The 6080 is capable of sound very rich, smooth, vibrant, and full bodied without a _hint_ of stuffiness or slowness.  It just sounds incredibly musical, competent, and articulate from end to end.  I'm going to do more comparative listening between the 5998 & 6080 this weekend (will probably leave the Tungsram in since I'm digging the transparency) to see what else I can pick up, but in the short time I've had both these drivers, the 6080 sounds like the more "complete"-sounding tube to me.


----------



## mikek200

Yes,I agree,with flysweep
  I do have a tungsram,& I get great sound from it ..
   
  Fly,what I used to do with the 6080 & the crack--I'd use it when I was listening to some fast ,bright music,such as -Albert Cummings,or,any fast rock music,it seemed to have brought down the sq down just enough ,to please my old cryoed ears.
  Just more .02..


----------



## skeptic

Makes sense.  6080's (and 6as7g's) have a higher output impedance than 5998's, so they should produce a slightly fatter, fuller sounding mid-bass.  5998's, by contrast, are higher gain, a bit brighter, clearer and more articulate, and have a more holographic soundstage to my ears.
   
  For a nice warm input tube to pair with hd800's and a 5998, I really like bugleboys.  When I want something more neutral and detailed, I swap in my 1959 TS 12bh7.


----------



## orri

Hi,
   
  New addict joining the Crack Anonymous.
   
  I recently installed the Speedball upgrade and while it did a lot of positives to the sound I also found it added some unwanted brightness. I'm using the HD650s and to be frank, they've never sounded this bright before. Since I'm really sensitive to brightness I'm seriously thinking about going back to the basic Crack.
   
  What I wanted to know is; has anyone else experienced this and could it be fixed with new tubes (I'm using stock tubes) without breaking the bank?


----------



## BmWr75

Try different driver tube to tame the brightness.  Maybe a Mullard 12au7.


----------



## dsound

The cheap RCA 6AS7G Black-plate also works well to roll-off the highs a bit (IMO)


----------



## gregr507

Quote: 





orri said:


> Hi,
> 
> New addict joining the Crack Anonymous.
> 
> ...


 
   
  What positives did you notice with the speedball? I currently have the crack and already have the speedball kit but haven't installed it yet (partially because I'm worried about adding too much brightness)


----------



## captouch

Quote: 





orri said:


> Hi,
> 
> New addict joining the Crack Anonymous.
> 
> ...


 
   
  I'm using HD650's with the Crack+Speedball, but don't notice any brightness.  I'm using a Telefunken 12AU7 and Tung Sol 5998.


----------



## mikek200

Quote: 





orri said:


> Hi,
> 
> New addict joining the Crack Anonymous.
> 
> ...


 
  Orri,
  What exact tubes are you using?
  Are they brand new??,& well broken in??


----------



## orri

Quote: 





gregr507 said:


> What positives did you notice with the speedball? I currently have the crack and already have the speedball kit but haven't installed it yet (partially because I'm worried about adding too much brightness)


 
  The sound gets tighter, faster and more dynamic i.e. less laid-back. The background also got quieter and I think I need to use less of the volume knob. But the sound did get a little brighter. The good thing is though that the upgrade is reversible...
   
   
   
  Quote: 





mikek200 said:


> Orri,
> What exact tubes are you using?
> Are they brand new??,& well broken in??


 
  I ordered two sets of tubes and got two 6080s and one each of 12au7 and 5963. These are the first tubes I've seen so I can't be sure if they are brand new or not...
   
  How long is the burn-in period of tubes?
   
  How long is the burn-in period of tubes and


----------



## mikek200

With the hd650,things should not be sounding overly bright..,when I had mine,the SQ was neutral ,to slightly warm..
  I usually give 100 hours breakin ,on a new tube.,some tubes might need  longer?
   
  I'd leave things as they are ,for atleast a week,before,uninstalling the speedball upgrade,or until you start to hear a change in the SQ???
  .


----------



## JmanOfIsrael

Received the kit yesterday and finished building it last night and everything checks out! Except one thing... is this the place to ask for help? Would someone point me out to the help forum if this is not the right one?
   
  My problem: Everything works fine when I plug the RCA to 3.5mm from the Crack directly into my phone or computers stereo jack. Sounds great! However, when I plug the 3.5mm end into my ODAC and then ODAC into MacBook via USB things get weird. The music sounds fine once it is playing but whenever I do anything on my computer the quality of the music gets warped and sounds terrible (a real noticeable difference). Even when I move the mouse on my computer this happens. I am very confused. Is it a problem with the ODAC you think, or maybe I should try plugging the DAC into a different USB port. The DAC seems to work fine with other amps so I'm worried something has been wired incorrectly but everything sounds fine when the source is plugged in directly via stereo jack.
   
  Thanks for any help answering or pointing me in the right direction!


----------



## ffivaz

jmanofisrael said:


> Received the kit yesterday and finished building it last night and everything checks out! Except one thing... is this the place to ask for help? Would someone point me out to the help forum if this is not the right one?
> 
> My problem: Everything works fine when I plug the RCA to 3.5mm from the Crack directly into my phone or computers stereo jack. Sounds great! However, when I plug the 3.5mm end into my ODAC and then ODAC into MacBook via USB things get weird. The music sounds fine once it is playing but whenever I do anything on my computer the quality of the music gets warped and sounds terrible (a real noticeable difference). Even when I move the mouse on my computer this happens. I am very confused. Is it a problem with the ODAC you think, or maybe I should try plugging the DAC into a different USB port. The DAC seems to work fine with other amps so I'm worried something has been wired incorrectly but everything sounds fine when the source is plugged in directly via stereo jack.
> 
> Thanks for any help answering or pointing me in the right direction!




I would check the dac... Could not understand how the dac could be influenced by the Crack. BTW, I had a similar problem with a Dell where the USB ports had a power problem (not enough power) to drive the dac, which worked perfectly when plugged to a powered USB hub...


----------



## JmanOfIsrael

Thanks for the help! I'm going to give it a try.


----------



## JmanOfIsrael

Quote: 





ffivaz said:


> I would check the dac... Could not understand how the dac could be influenced by the Crack. BTW, I had a similar problem with a Dell where the USB ports had a power problem (not enough power) to drive the dac, which worked perfectly when plugged to a powered USB hub...


 
  Man, I wish I could give you a hug! That did the trick exactly! This thing with the HD650s is incredible. I've never had such a quiet background with a full sound. My next question: where should I keep the volume on my computer vs. the volume on the Crack?


----------



## Armaegis

My initial thought was a usb power supply issue as well. If running on your desktop, a port on the opposite side of the computer might be running off a different card bus and thus might have less of a power issue (depending what else is plugged into it). 
   
  For volume control, typically you will keep the digital side at maximum (or close to) and handle attenuation on the amp. In general this will maximize your signal to noise. Some exceptions to this would be if your dac output is clipping for some reason, if the amp has input protection (that clips if the signal is too high), or if the amp gain is so high that you have no useable range on the pot.


----------



## Doc B.

Yes, I have found fairly often that it is best keep keep the digital level control just a dB or two below max, because there can be an occasional track that will clip at full volume.


----------



## JmanOfIsrael

Thanks very much for the responses. I am still in awe of how clear the soundstage is on orchestral recordings. I feel like live music is going to have an entire new feel. As this was my first build, I still can't believe I built this thing in 8 hours and I made no (obvious) technical mistakes. Doc B., your instructions were incredibly clear and easy to read while very informative--I felt like I was getting a valuable lesson in electronics! Thanks again!
   
  As I burn the Crack in, do you recommend I play music through it, or is it enough just to leave it on for several hours at a time followed by a lengthy resting period?


----------



## ffivaz

In my opinion, digitally reducing the volume on a USB dac (like the ODAC) equals introducing jitter in the music. And this is equal or quite equal to lower SQ. Am I wrong ?


----------



## Beefy

Quote: 





ffivaz said:


> In my opinion, digitally reducing the volume on a USB dac (like the ODAC) equals introducing jitter in the music. And this is equal or quite equal to lower SQ. Am I wrong ?


 
   
  Audible jitter is a figment of your imagination.
   
  Reducing digital volume can reduce sound quality at low bit depths or with crappy software. But for a 24-bit DAC with decent software it will be inaudible.


----------



## Doc B.

Quote: 





jmanofisrael said:


> Thanks very much for the responses. I am still in awe of how clear the soundstage is on orchestral recordings. I feel like live music is going to have an entire new feel. As this was my first build, I still can't believe I built this thing in 8 hours and I made no (obvious) technical mistakes. Doc B., your instructions were incredibly clear and easy to read while very informative--I felt like I was getting a valuable lesson in electronics! Thanks again!
> 
> As I burn the Crack in, do you recommend I play music through it, or is it enough just to leave it on for several hours at a time followed by a lengthy resting period?


 
  Music playing is the best way to break in the amp.
   
   


> In my opinion, digitally reducing the volume on a USB dac (like the ODAC) equals introducing jitter in the music. And this is equal or quite equal to lower SQ. Am I wrong ?


 
  If you have a recording that is distorting from clipping the DAC output at max volume and you feel the SQ will be worse if you reduce the output level to just below clipping, I'm guessing that we probably have different listening habits.


----------



## Beefy

Quote: 





doc b. said:


> If you have a recording that is distorting from clipping the DAC output at max volume and you feel the SQ will be worse if you reduce the output level to just below clipping, I'm guessing that we probably have different listening habits.


 
   
  Oh, SNAP.


----------



## Dark Helmet

Quote: 





jmanofisrael said:


> Man, I wish I could give you a hug! That did the trick exactly! This thing with the HD650s is incredible. I've never had such a quiet background with a full sound. My next question: where should I keep the volume on my computer vs. the volume on the Crack?


 
  I know for iTunes on a Mac you have two volume controls.  One for iTunes which I would put at about three quarters of the way up and you can go all the way to about 1 db or 2 below full on the main system volume, as Doc redommended.  I have always found a lot of distortion on the volume with iTunes up too high.  Experiment with this one and find he happy spot for you.


----------



## liamstrain

Quote: 





ffivaz said:


> In my opinion, digitally reducing the volume on a USB dac (like the ODAC) equals introducing jitter in the music. And this is equal or quite equal to lower SQ. Am I wrong ?


 
   
  There is no indication that this is the case. Certainly not jitter. Possibly removing some digital data (but not as much as clipping would cause), depending on the bit rate and other factors - audibility is another question, and for a couple of DB down, would be very hard to demonstrate reliably in objective testing.


----------



## ffivaz

Looks like I confused jitter and dither, which is bad for me, but not for the music. Thanks guys.


----------



## FlySweep

Another Bendix 6080WB arrived today.. this one has the _slotted_ graphite columns (opposed to the _solid_ graphite columns that the other 6080 I have provided impressions of).  Haven't had a ton of time to listen & compare.. but so far, it seems like a marriage between the best aspects of the 6080/solid graphite & the TungSol 5998.
   
  The 6080/slotted graphite tube is less liquid, rich, and warm than the 6080/solid graphite.. but it's more transparent, neutral, and resolving.. perhaps even more than the 5998, in fact.  The 6080/slotted graphite's soundstage and dynamics are _eye-popping_.  Again, it probably has a leg up on the 6080/solid graphite in this area (which, in turn, I found to be more dynamic than the 5998).  It preserves the terrific bass response of the 6080/solid graphite.. but possesses better extension and clarity (from end to end).  The 6080/solid graphite has a 'fatter' bass response.. the 6080/slotted graphite's bass is just as dynamic and punchy. but it's tighter and cleaner than the solid graphite's bass response.  The 6080/slotted graphite's midrange is neutral, smooth, & incredibly vibrant.  The 5998 sounds thin, in comparison (to me).
   
  So far, this seems to be my favorite driver tube for Crack.  I'm going to try and get a Sylvania "Gold Brand" 6080.. just to see if it's immense 'liquidity' is all that it's cracked up to be... and for a different flavor.  I'll have more comparisons between the 6080/slotted graphite & the 5998 later.


----------



## Doc B.

Small technical point - in tube circuits the big tube that runs the speaker or headphone is called the output tube - in this case the 6080. The smaller tube that drives the output tube is called the driver - in this case the 12AU7.


----------



## Dark Helmet

Quote: 





flysweep said:


> Another Bendix 6080WB arrived today.. this one has the _slotted_ graphite columns (opposed to the _solid_ graphite columns that the other 6080 I have provided impressions of).  Haven't had a ton of time to listen & compare.. but so far, it seems like a marriage between the best aspects of the 6080/solid graphite & the TungSol 5998.
> 
> The 6080/slotted graphite tube is less liquid, rich, and warm than the 6080/solid graphite.. but it's more transparent, neutral, and resolving.. perhaps even more than the 5998, in fact.  The 6080/slotted graphite's soundstage and dynamics are _eye-popping_.  Again, it probably has a leg up on the 6080/solid graphite in this area (which, in turn, I found to be more dynamic than the 5998).  It preserves the terrific bass response of the 6080/solid graphite.. but possesses better extension and clarity (from end to end).  The 6080/solid graphite has a 'fatter' bass response.. the 6080/slotted graphite's bass is just as dynamic and punchy. but it's tighter and cleaner than the solid graphite's bass response.  The 6080/slotted graphite's midrange is neutral, smooth, & incredibly vibrant.  The 5998 sounds thin, in comparison (to me).
> 
> So far, this seems to be my favorite driver tube for Crack.  I'm going to try and get a Sylvania "Gold Brand" 6080.. just to see if it's immense 'liquidity' is all that it's cracked up to be... and for a different flavor.  I'll have more comparisons between the 6080/slotted graphite & the 5998 later.


 
  I jsut got one of the Bendix slotted 6080 the other day from a friend who gets NOS tubes for $35.  He's bringing me some clear top RCA's for $5 today.  Once I get some technical issues sorted out with my crack I'll get a chance to run these through their paces.


----------



## FlySweep

doc b. said:


> Small technical point - in tube circuits the big tube that runs the speaker or headphone is called the output tube - in this case the 6080. The smaller tube that drives the output tube is called the driver - in this case the 12AU7.


 
   
  Thanks Doc.. I tend to mix those terms up when I ramble on. 



dark helmet said:


> I jsut got one of the Bendix slotted 6080 the other day from a friend who gets NOS tubes for $35.  He's bringing me some clear top RCA's for $5 today.  Once I get some technical issues sorted out with my crack I'll get a chance to run these through their paces.


 
   
  Looking forward to your thoughts on the Bendix tube.. glad to see someone else getting their hands on one.  Terrific price you got it for, too.
   
  I rolled the Tung-Sol "black plate" in with the 6080/slotted graphite tonight.. _oh my goodness_.  The HD800 sounds _*unreal*_.  I could go on and on about all the impressive sonic aspects.. but one particular thing that kept impressing me was the wonderfully natural separation of sounds, voices, and instruments.  Opposed to some tubes that "lift" a particular band (i.e. vocals) above the rest to perpetuate a (false) sense of separation, this combo separates everything with incredibly natural, _realistic_ precision.  For anyone who thinks the HD800 doesn't do metal as well as some other TOTL phones hasn't heard it with the 6080-slotted graphite/TS "black plate" combo.  If you listen to rock music, this may be a 'holy grail' tube.  The crunch of electric guitars is _so_ full bodied, articulate, and.. here's that word again.. _realistic_.
   
  I found the slotted graphite/TS BP combo preferred to be played at slightly higher volumes, too.  Dynamics seem to find their sweet spot with a bit more gain.  I've been listening to a lot of my favorite rock & metal albums and even at high volumes, fatigue _never_ set in thanks to this tube's ability to sound very lively, dynamic with impeccable control.  After listening for the last three or fours hours, I realized why I'm so impressed with the 6080-slotted graphite/Tung-Sol "black plate" tube combo: it harmoniously balances the best aspects of (what I traditionally associate with) solid state & tube sounds.  I'm not sure how the BP sounds in other OTL amps, but it's a "tour de force" in the SB'ed Crack.


----------



## FlySweep

Well, well.. maybe I've been impatient with the 5998 or it's just now opening up.. looks like I might be eating _some_ of my words on it's performance.  It's ok, though.. this is the best tasting crow I've had in awhile.


----------



## Dark Helmet

No having any luck at the Bottlehead forum so I'll ask here.  I just installed the Goldpoint MiniV stereo Attenuator in My Bottlehead Crack.  In the process of doing so I had to remove some components and when I went to do my voltage check I noticed that at terminal 6 and 10 it measures 40V, when it should measure 0V.


----------



## Armaegis

Well, that kinda tells me that something that should be grounded... isn't.


----------



## Beefy

Quote: 





dark helmet said:


> No having any luck at the Bottlehead forum so I'll ask here.  I just installed the Goldpoint MiniV stereo Attenuator in My Bottlehead Crack.  In the process of doing so I had to remove some components and when I went to do my voltage check I noticed that at terminal 6 and 10 it measures 40V, when it should measure 0V.


 
   
  I'm not surprised you aren't having luck, because you haven't exactly given us much to go on.
   
  What, exactly, did you have to remove? Any photos? What have you actually tried to do to fix it?
   
  [EDIT] OK, so I whipped out my schematic, and terminals 6 and 10 are after the output capacitors and are connected directly to the headphone jack. This means that the capacitors are not bleeding down the DC; I hope you didn't plug your headphones in. I suspect that either your grounding at the headphone jack has been disconnected from both the volume pot and terminal 12, or your resistors at the headphone jack are not connected properly.


----------



## BmWr75

Quote: 





dark helmet said:


> No having any luck at the Bottlehead forum so I'll ask here.  I just installed the Goldpoint MiniV stereo Attenuator in My Bottlehead Crack.  In the process of doing so I had to remove some components and when I went to do my voltage check I noticed that at terminal 6 and 10 it measures 40V, when it should measure 0V.


 
   
  Stupid is as stupid does.


----------



## audiowize

Quote: 





dark helmet said:


> No having any luck at the Bottlehead forum so I'll ask here.  I just installed the Goldpoint MiniV stereo Attenuator in My Bottlehead Crack.  In the process of doing so I had to remove some components and when I went to do my voltage check I noticed that at terminal 6 and 10 it measures 40V, when it should measure 0V.


 
   
  A response time of ~24 hours is pretty reasonable for a tech support forum, 6 hours is asking a little much.


----------



## JmanOfIsrael

Hey guys, I just encountered my first problem with the Crack. It was fine a week ago after I had finished it; played beautiful sound with no background noise. Now a prominent crackling sound with a slight buzz appears in the left channel and very faintly in the right channel. The noise stays for 15 seconds and then goes away. Sometimes it returns a minute or two later and other times it comes back a day later. The trouble shoot say this may mean a bad tube. Which tube would I need to replace? Do you guys have any other suggestions where to check for a cold solder joint or something else like that? Thanks for any help!


----------



## JmanOfIsrael

Quote: 





jmanofisrael said:


> Hey guys, I just encountered my first problem with the Crack. It was fine a week ago after I had finished it; played beautiful sound with no background noise. Now a prominent crackling sound with a slight buzz appears in the left channel and very faintly in the right channel. The noise stays for 15 seconds and then goes away. Sometimes it returns a minute or two later and other times it comes back a day later. The trouble shoot say this may mean a bad tube. Which tube would I need to replace? Do you guys have any other suggestions where to check for a cold solder joint or something else like that? Thanks for any help!


 
  To add to this. Sometimes I find that turning the amp off for 5 minutes and then back on is all that is needed to stop this sound. Thanks again for any help!


----------



## Dark Helmet

armaegis said:


> Well, that kinda tells me that something that should be grounded... isn't.




I should be flogged for spacing on this but after further inspection I didn't have the I put jack grounded. Sorry for not replying sooner. I pretty much figured it out shortly after posting. All is well.


----------



## Dark Helmet

audiowize said:


> A response time of ~24 hours is pretty reasonable for a tech support forum, 6 hours is asking a little much.




I just thought it was a good idea to post elsewhere to see if I could get a response quicker. I wasn't trolling for you on this forum. Typically if I need info or answers i always get it faster here than any other forum. Sorry for the trouble.


----------



## liamstrain

Quote: 





jmanofisrael said:


> To add to this. Sometimes I find that turning the amp off for 5 minutes and then back on is all that is needed to stop this sound. Thanks again for any help!


 
   
  Any other details you can add? What is your source? And does it happen even if you try a different audio input (e.g. MP3 player, vs. computer, vs. cd player)?


----------



## JmanOfIsrael

I haven't tried another input. I am running from a MacBook>ODAC>Bottlehead. I initially had problems with my USB port on my MacBook. I will see if this trend continues if I leave the source unplugged. I will also try switching the source.


----------



## Dark Helmet

How do you like the ODAC with the Crack?


----------



## JmanOfIsrael

Quote: 





dark helmet said:


> How do you like the ODAC with the Crack?


 
  It has been great so far! Granted, this is my first decent DAC. But virtually no background noise and wonderful instrument separation would be the two features that stand out to me the most when I use the ODAC vs. strait out of my MacBook.


----------



## Dark Helmet

I'm definitely considering the ODAC.


----------



## JmanOfIsrael

I was between the odac and the HRT music streamer ii. They are both comparable, I just managed to find the odac on head-fi used so went with that option. I really am loving it with the crack besides the little hiccup I have recently encountered.


----------



## Dark Helmet

Do you have a cell phone near the cables or the ODAC?  If so move it out of the way.  It can definitely cause intermittent noises like that.  It may still be a tube, but try and rule out other things also.


----------



## JmanOfIsrael

Not a bad idea actually, I use my cellphone for internet connection. I will try moving it out of the room!


----------



## ffivaz

Quote: 





jmanofisrael said:


> Hey guys, I just encountered my first problem with the Crack. It was fine a week ago after I had finished it; played beautiful sound with no background noise. Now a prominent crackling sound with a slight buzz appears in the left channel and very faintly in the right channel. The noise stays for 15 seconds and then goes away. Sometimes it returns a minute or two later and other times it comes back a day later. The trouble shoot say this may mean a bad tube. Which tube would I need to replace? Do you guys have any other suggestions where to check for a cold solder joint or something else like that? Thanks for any help!


 
   
  I had a similar problem. The Crack buzzed and popped when warm, only after a couple of minutes, in the left channel. It disappeared when I changed the 6080 tube (the big one). You can also try the chopstick test to look for cold solder joints : try pocking all the connections inside with a wooden stick (be careful doing this). The buzz and popping should get worse when you hit the part with a bad joint. And try pocking the tubes to see which one is bad.


----------



## FlySweep

So.. I had a couple of tubes arrive today... an E80CC & a 12BH7.  Rolled them into the Crack a few hours ago (w/ the 5998 in the output position).  Wow.  I'll keep it short for now:
   
  I don't think I can go back to a 12AU7 tube.. *any 12AU7*, actually.
   
  More later..


----------



## Dark Helmet

What DAC ar you guys using with the Crack.  I'm thinking about getting a DAC to pair with my Mac Mini.   
  was thinking about starting cheap with either the ODAC, Schiit Modi, or HRT MS II.  Also considering using Amarra with this setup.  Any thoughts or suggestions?
   
  I'll be using my HD600's with it.


----------



## uzi

Quote: 





dark helmet said:


> What DAC ar you guys using with the Crack.  I'm thinking about getting a DAC to pair with my Mac Mini.
> was thinking about starting cheap with either the ODAC, Schiit Modi, or HRT MS II.  Also considering using Amarra with this setup.  Any thoughts or suggestions?
> 
> I'll be using my HD600's with it.


 
  I used to use the HRT MS II, and I found the ODAC was very similar to it.  (I imagine the Modi would be as well.)
   
  I'm currently using the HRT MS II+, which is noticeably better than the HRT MS II.  More detailed, better soundstage, etc.


----------



## GeorgeNapalm

I'm using Bifrost and now after Uber upgrade it's an absolutely amazing combo.


----------



## FlySweep

> Originally Posted by *Dark Helmet* /img/forum/go_quote.gif
> 
> What DAC ar you guys using with the Crack.  I'm thinking about getting a DAC to pair with my Mac Mini.
> was thinking about starting cheap with either the ODAC, Schiit Modi, or HRT MS II.  Also considering using Amarra with this setup.  Any thoughts or suggestions?
> ...


 
   
  I'm using the ODAC with my Crack.  I find it to be a terrific DAC that doesn't feel like a bottleneck in the slightest.  In fact, I prefer to use the ODAC over the Violectric V800 with the BH Crack (why?  I'm not entirely sure.. I just like the synergy more for some reason).  I'm tempted to upgrade but it's really difficult to make the move cause the ODAC isn't giving me a reason to buy something else.  It's exceptionally clean, compact, and transparent.


----------



## Dark Helmet

I went ahead and ordered the Schiit Modi.  It should be here by Friday. I've heard many good things about it, and at $99 it will be my entry into the DAC world.  A no brainer I think.


----------



## Dark Helmet

Just a friendly reminder if you guys decide to buy a 6SN7 to 12AU7 adapter (8 pin to 9 pin) from e-bay.  Do not buy it from Lowther Club.  I got one that was crooked and had a glob of solder on one of the pins.  Perhaps mine was a fluke but apparently it's not because he thought it was just fine
   
   After sending him pictures which he asked for his reply was.  It's hand made it's not going to be perfect and to just scrape the solder off or cycle the tube in and out of the socket with the solde glob on there
	

	
	
		
		

		
		
	


	




.  I wasn't looking for perfection, I just wanted it to be straight.  I had to open a case with e-bay and the guy has been antagonistic towards me and he is the seller.  After I told him to stop e-mailing me he continues to do so.  Do not buy from this guy.  Bad dude!  
   
  To be fair i did call him a moron and an idiot
	

	
	
		
		

		
		
	


	




 (dude was relentless).   I did so after he accused me of saying that I expected a full refund and that I was not going to send it back, which I did not.  Anyway e-bay is well aware of what is going on, but I thought I should warn you guys.


----------



## mikek200

Quote: 





dark helmet said:


> I went ahead and ordered the Schiit Modi.  It should be here by Friday. I've heard many good things about it, and at $99 it will be my entry into the DAC world.  A no brainer I think.


 
  It's definetly a no brainer
  I just got delivery ,yesterday of the Magni,I was totally amazed at the SQ.
  I'm using it with the Uber Bifrost & the HD800's
  I've had a few Schiit amps ,Lyr,Mjolnir,now this..it even drives my Maddogs,perfectly.
   
  Going to order the M&M combo ,for my daughter ,whose in college-it will be perfect for her dorm audio setup.
   
  Good luck Dark Helmet,with the new toy


----------



## BmWr75

I am running a G.E. JAN 5998A Sylvania JAN 6080WC (black plate) power tube right now.  Rolled in an Amperex 12AU7 as the driver tube.  Result was a very solid state sounding amp.  My Crack has the Speedball upgrade and 100uF metallized polypropylene output capacitors.
   
  I then switched to a G.E. E80CC driver and it resulted in a very different sounding amp to me.  More tubey, better sound stage, just more fun to listen to.
   
  EDIT - I should have put my glasses on, the actual power tube I am running is a Sylvania JAN 6080WC (black plate)


----------



## Dark Helmet

mikek200 said:


> It's definetly a no brainer
> I just got delivery ,yesterday of the Magni,I was totally amazed at the SQ.
> I'm using it with the Uber Bifrost & the HD800's
> I've had a few Schiit amps ,Lyr,Mjolnir,now this..it even drives my Maddogs,perfectly.
> ...




Mike,

Is there a slight imperfection, a spot that looks irregular about 3/4 of an inch from the left curve cutout on the Magni?


----------



## Dark Helmet

bmwr75 said:


> I am running a G.E. JAN 5998A power tube right now.  Rolled in an Amperex 12AU7 as the driver tube.  Result was a very solid state sounding amp.  My Crack has the Speedball upgrade and 100uF metallized polypropylene output capacitors.
> 
> I then switched to a G.E. E80CC driver and it resulted in a very different sounding amp to me.  More tubey, better sound stage, just more fun to listen to.




The E80CC will be the next tube I try. I've tried the BH7 and I liked but it subdued the output and the soundstage a bit. I'm currently using an RCA clear top 12AU7 with an RCA 6AS7G.


----------



## mikek200

Quote: 





dark helmet said:


> Mike,
> 
> Is there a slight imperfection, a spot that looks irregular about 3/4 of an inch from the left curve cutout on the Magni?


 
  Nope


----------



## Dark Helmet

Quote: 





mikek200 said:


> Nope


 
  Just sent this pic to Jason at Schiit and he said all the ones he has are like this.  Now mind you it's more noticeable in person.


----------



## mikek200

My irregularity looks  pretty regular to me???
   
  Are you referring to the curve in the metal  base??


----------



## Dark Helmet

No, just to the right of the left cutout about 3/4 of an inch away on the straight edge, there is a spot that sticks down a bit.


----------



## Beefy

Quote: 





dark helmet said:


> No, just to the right of the left cutout about 3/4 of an inch away on the straight edge, there is a spot that sticks down a bit.


 
   
  I can see what you mean, but..........
   
  Seriously? I mean that actually bothers you? ~10,000 children die of starvation every day, and that tiny little imperfection on a $99 product is what occupies your thoughts?


----------



## Armaegis

One minute with a piece of sandpaper ought to fix that.


----------



## mikek200

Quote: 





dark helmet said:


> No, just to the right of the left cutout about 3/4 of an inch away on the straight edge, there is a spot that sticks down a bit.


 
  well,on your pic,it looks like part of the amp itself-not the metal case--in your pic,it is black in color?could be a slight mis alighnment in the case fitting-if we are talking about the same thing?
  I checked my amp,& I do NOT have that showing.
   
  Question:
  Are you having any kind of issues with this amp?,& why,are so focused on this?
  Do you feel it is causing you some sort of problem,& why are you being so anal about it?
  Wish I could be more help.but I feel if it is not causing any problems..leave it alone,& it will leave you alone.
   
  Enjoy the amp,thats what I'm doing,& I love it-Jason's the best--$99-bucks..lol.-Jesus


----------



## Dark Helmet

Mike, 

It's on the silver edge.u

Mike and Beefy,

Because where it sits in my listening area, its right in front of my face. That and my neurotic ness. I know, lame for a $99 item, but I can't help it. I'll get over it, just the newness factor of it I guess. Just wanted to see if others had the same spot. I sounds really good, though I have no other DAC's to compare it too.


----------



## mikek200

DH,
  Not the end of the world--I did the same thing ,after I got the Lyr.kept insisting I was hearing a slight crackling noise in the right side--turns out it was the tube.
  Its all part of the new gear syndrome-I guess
  Are you planning on getting the Magni--I'd be interested in having you do an A/B test with the crack?..I know,I know..just curious
   
  Just for the record,I have the Magni,not,the Modi.
  My Taboo is in for a warranty re-certification,thats why I bought the Magni,just needed an amp to tied my over ,untilI get the Taboo back
  But,I must say,I love this little amp..drives my Hd800,& Maddogs perfectly
   
  Enjoy your new dac..


----------



## Dark Helmet

No, no plans for the Magni. I also have the O2 and the C&C BH. Maybe a better DAC down the road. For now, just music.


----------



## W0lfd0g

It lives! - "Crack of Dawn"
   

   

   

   

   
  I can't help but saying that I am pretty darn proud of myself as this is my first real build, not including a cmoy.  I know that sounds lame as everyone reading this has probably been there and done it a million times before.  There is just such a buzz from firing it up for the first time and listening to music through a product that wouldn't have existed without your own handiwork.  The fact that this has been repeated thousands of time all over the world is a credit to Bottlehead.  Thanks Doc and the rest of the team.


----------



## dsound

Congrats on completing the build!  Did you get a chance to listen to the Crack in stock form before you upgraded?  
   
  I have just started a non-Bottlehead amp project and miss Doc's insanely-detailed instruction manual.
  Quote: 





w0lfd0g said:


> It lives! - "Crack of Dawn"
> 
> I can't help but saying that I am pretty darn proud of myself as this is my first real build, not including a cmoy.  I know that sounds lame as everyone reading this has probably been there and done it a million times before.  There is just such a buzz from firing it up for the first time and listening to music through a product that wouldn't have existed without your own handiwork.  The fact that this has been repeated thousands of time all over the world is a credit to Bottlehead.  Thanks Doc and the rest of the team.


----------



## W0lfd0g

Thanks dsound.

Unfortunately I raced ahead with the project and added all the upgrades at once. Should have taken the time to learn from he effects of each upgrade. I'm sure to do another Bottlehead build some time soon and will take my time.

I don't think I have ever seen a better set of instructions in my life. Even a know-nothing like me can come away with a great product and great learning experience.

Let us know how you go with the new amp.

Cheers


----------



## Armaegis

Wow, I think that wins for the biggest caps I've ever seen in a Crack. Next up... Mainline!


----------



## W0lfd0g

Who said that good things come in small packages?


----------



## walls

Just ordered a Crack, sure hope its as easy to build as everyone says LOL!!  This is my first attempt at something like this and I figured its a good way to start.
   
  Can anyone give me rec's on which tools I will need? I think I have most/all but anything you guys think made your build easier will sure help me too.


----------



## dsound

Congrats on your order!  A good pair of wire-strippers will help your process a lot, I have the Irwin 2078317 and love it.  
   
  The other thing that I absolutely love is my Tip Tinner.  It keeps my soldering iron's tip nice and clean (and tinned).  When I first started out I couln't understand why my iron was not getting hot enough, it was because the tip was not appropriately tinned.


----------



## W0lfd0g

Good luck, although I'm sure you won't need it. The hardest part is the wait. 

If you do get stuck during the build or hit any problems after, the guys on the Bottlehead forum responding quickly and helpfully. They are very generous with their knowledge and experience.

Here is the link, just in case you haven't seen it before:

http://www.bottlehead.com/smf/index.php/board,24.0.html

Cheers.


----------



## Armaegis

Quote: 





walls said:


> Just ordered a Crack, sure hope its as easy to build as everyone says LOL!!  This is my first attempt at something like this and I figured its a good way to start.
> 
> Can anyone give me rec's on which tools I will need? I think I have most/all but anything you guys think made your build easier will sure help me too.


 
   
  Pre cut and strip all your wires (and lightly tin if you want). It makes your life so much easier during the actual build.


----------



## walls

Hey thanks guys!  I will post pics of my progress as it goes, of course thats after I get the kit. Hopefully it will be here within 4 weeks and not much longer.
   
  I was going to have it built but I figure the satisfaction of doing it myself will make the bang for the buck even better.
   
  I am not too sure what to expect, I am sure it wont touch my WA2 but I am anxious to see how it compares to the LittleDot.


----------



## Draygonn

walls said:


> I am not too sure what to expect, I am sure it wont touch my WA2


With the 650s I slightly preferred the Crack/Speedball/TS5998, with HD800s I preferred the WA2 by a larger margin. No contest in the looks department though, WA2 is the best looking amp IMO.


----------



## walls

Well I honestly hope that I like my WOO more. LOL. I can't wait to get this amp!!


----------



## W0lfd0g

Quote: 





draygonn said:


> With the 650s I slightly preferred the Crack/Speedball/TS5998, with HD800s I preferred the WA2 by a larger margin. No contest in the looks department though, WA2 is the best looking amp IMO.


 
   
  One of the joys of DIY is that you can customise the kit to look how you want.  It may not measure up to the WA2, but beauty is in the eye of the beholder.
   
  Here is Skylab's customised Crack case:


----------



## StivVid

Screwed up this post.  What I meant to say is below...


----------



## StivVid

Quote: 





silverhead said:


> Apparently with the 12AU7 to 6SN7 there is a difference between the 6.3V and 12V version of the adapters.   The ebay seller told me that the one I have that doesn't work is wired for 12V and that I need the 6.3V version.
> 
> I have no idea if this is true or not, but I wanted to relay the info here for anyone concerned.


 
   
  So...  I've just ordered one of these adapters too.  Mine is the 6.3V version.  Did I order the right thing?


----------



## Dark Helmet

Who did you order it from?


----------



## Beefy

Quote: 





walls said:


> Well I honestly hope that I like my WOO more. LOL. I can't wait to get this amp!!


 
   
  If that is what you hope for, then that is what will happen. Expectation is like that.
   
  Of course whether you are actually right or not flies completely out the window......


----------



## shotgunshane

I just received my second hand crack purchased from the classifieds here. It's a limited edition Bottlehead built and sold last year. I believe 1 of 6. 

Sounds wonderfully delicate with my HD600. Very nice air, space and background silence. I'm going to enjoy this combo very much.


----------



## walls

Quote: 





beefy said:


> If that is what you hope for, then that is what will happen. Expectation is like that.
> 
> Of course whether you are actually right or not flies completely out the window......


 

 Actually I am pretty honest with myself and if I like the Crack more I will admit it, I just made the comment because if I DO like the Crack more then there goes $1200. LOL!!
   
  I have only heard about a dozen headphone amps and the WA2 is my fave so far, it is one hard amp to beat honestly.


----------



## amcananey

I have tried (meaning bought and lived with for an extended period, not just briefly listened to) dozens of amps. I've owned a WA6 and WA22. The WA22 had about $600-700 worth of upgrade tubes. I had it before I built my Crack. As soon as I built the Crack (and had lived with it long enough to be sure that what I was hearing was real), I sold the WA22 and have never regretted it. The Crack demolished the WA22 with my HD800s. By comparison, the WA22 sounded thick, slow and muffled. Of course, the WA6 and WA22 are WOT, which might account for the difference, and I have certainly heard good things about the WA2 (which is obviously OTL). 

Best regards,
Adam


----------



## JmanOfIsrael

I recently added the GEC Brown Strait Base 12AU7 to the Crack and it is incredible. I am still astonished at how quiet the background is. I am considering how much a DAC upgrade (from the odac) would improve the sound.


----------



## Beefy

Quote: 





amcananey said:


> Of course, the WA6 and WA22 are WOT, which might account for the difference, and I have certainly heard good things about the WA2 (which is obviously OTL).


 
   
  The truth of the matter is, aside from the WA2 using paralleled sections on the output and thus having higher peak power output, the Crack is potentially a FAR better amp.
   
  With a Speedball, you have a much better tube load than the resistors in the WA2. LED biasing should be superior. Bit hard to tell from the photos whether the WA2 is direct or AC coupled. Add a good pot and film caps on the output, and you are miles ahead for far lower cost.


----------



## geetarman49

Quote: 





jmanofisrael said:


> ... GEC Brown Strait Base 12AU7 ...


 
  ???


----------



## JmanOfIsrael

Quote: 





geetarman49 said:


> ???


 
  6AS7G! My bad, got confused between input and driver tubes!!


----------



## geetarman49

i thought as much ... unfortunately, current pricing on those is just plain scary.


----------



## JmanOfIsrael

I couldn't agree more, I got mine off eBay for $165 shipped while biting my lip the entire time. I'm not much of a tube roller so I feel okay considering that is the only tube, excluding the stock GE tube, I own. Unfortunately, I am guessing that quality tubes will only go up in price since they aren't manufactured anymore.


----------



## BmWr75

Quote: 





stivvid said:


> So...  I've just ordered one of these adapters too.  Mine is the 6.3V version.  Did I order the right thing?


 
   
  I have the 6.3V version and it works fine.  Somebody reported receiving the 12V version and it didn't work with the Crack.  I'm not sure why they even sell a 12V version that you plug a 6SN7 into that has a 6.3V heater filament.  Maybe someone else can explain this.


----------



## skeptic

6.3v is the right one.  Unfortunately, my experience with these adapters doesn't quite match bmwr's.  The first one I ordered had a horrible buzz in the left channel that increased in loudness as you turned up the volume.  The second one, from a different vendor, is arguably "listenable", but has a bit of audible noise in both channels.  (Also - from other posters here and on the bh boards, I know I'm not the only one who has dealt with QC issues, so caveat emptor when dealing with the overseas ebay sellers who make these things...)
   
   
  The only thing my forray into adapters and 6sn7's really accomplished was to show me how very much I love my dead quiet, faultless tung sol 12bh7.  
   
  ---
   
  As an aside, in reference to the discussion of woo amps above - the transformer coupled amps in their lineup are actually faster and more dynamic sounding than their otl options.  So you definitely want to stick to the speedball crack, and stay away from the wa3 and wa2 if you found the wa6 and wa22 thick and slow sounding.  To my ears, a speedball crack (made even better with the upgrades recommended by beefy above) bests all of these amps by a significant margin, particularly with hd800's.


----------



## Dark Helmet

Quote: 





skeptic said:


> 6.3v is the right one.  Unfortunately, my experience with these adapters doesn't quite match bmwr's.  The first one I ordered had a horrible buzz in the left channel that increased in loudness as you turned up the volume.  The second one, from a different vendor, is arguably "listenable", but has a bit of audible noise in both channels.  (Also - from other posters here and on the bh boards, I know I'm not the only one who has dealt with QC issues, so caveat emptor when dealing with the overseas ebay sellers who make these things...)
> 
> 
> The only thing my forray into adapters and 6sn7's really accomplished was to show me how very much I love my dead quiet, faultless tung sol 12bh7.
> ...


 
  Add a Goldpoint stepped attenuator and it gets even better.


----------



## skeptic

Always wanted to try a goldpoint, but I'm very wary of steps on a hp amp.  I feel like I am making minute adjustments to my volume all the time - so I went with beefy's suggestion of a well regarded pot: http://www.partsconnexion.com/tkd_64186.html  No regrets here!


----------



## Dark Helmet

I got the Mini-V Custom Goldpoint and populated it with Dale's, which was Doc's recommendation.  Very big sonic improvement.  I have heard good things about the TKD as well.  The steps on the Goldpoint, however, aren't drastic.


----------



## amcananey

beefy said:


> The truth of the matter is, aside from the WA2 using paralleled sections on the output and thus having higher peak power output, the Crack is potentially a FAR better amp.
> 
> With a Speedball, you have a much better tube load than the resistors in the WA2. LED biasing should be superior. Bit hard to tell from the photos whether the WA2 is direct or AC coupled. Add a good pot and film caps on the output, and you are miles ahead for far lower cost.




Well, I've got the Speedball installed, and I also installed a TKD volume pot and 100uf ClarityCap ESA film caps on the output, plus I bypassed the last cap on the power supply, again with a ClarityCap ESA. As for output power, I actually installed a pair of in-line RCA signal attenuators on the inputs on my Crack, since I actually found it had too much gain...

Oh, and I'm using a GEC straight brown base 6AS7G and I've got a decent selection of driver tubes (12AU7, 12BH7 and E80CC).

Of all of my amps, the one I am least willing to part with is my Crack. Check my profile...


Adam


----------



## amcananey

If I were doing it over again, I wouldn't have spent $100 on the TKD. I don't have any complaints about the TKD, I'm just not sure its the best use of money. I've built a Bottlehead Quickie with various upgrades, including a Vintage Audio Lab (VALab) ladder-style stepped attenuator. I think the VALab has the edge over the TKD, although it is difficult to really be sure about this kind of thing. But for $25, it seems like an absolute steal. After I finish building my balanced M^3, I will be building a Bottlehead Smack and a S.E.X. I will drop VALab attenuators into each of them. FYI, I found the steps in the VALab to be small enough to make it easy to find a comfortable volume level. I do recommend using a larger, heavier knob with a stepped attenuator, however. It improves the ergonomics in practice, since stepped attenuators are harder to turn than volume pots, and the larger knobs give greater leverage and grip.

Best regards,
Adam


----------



## Beefy

Quote: 





amcananey said:


> If I were doing it over again, I wouldn't have spent $100 on the TKD. I don't have any complaints about the TKD, I'm just not sure its the best use of money. I've built a Bottlehead Quickie with various upgrades, including a Vintage Audio Lab (VALab) ladder-style stepped attenuator. I think the VALab has the edge over the TKD.....


 
   
  It is entirely possible that the VALab has the edge, but there is no way I would ever trade out a 'proper' smooth pot like the TKD for a stepped attenuator. Not being able to find an exact volume level would drive me nuts.


----------



## W0lfd0g

Quote: 





beefy said:


> It is entirely possible that the VALab has the edge, but there is no way I would ever trade out a 'proper' smooth pot like the TKD for a stepped attenuator. Not being able to find an exact volume level would drive me nuts.


 

 Are there any disadvantages to making minute controls to volume via source - eg preamp or DAC with a volume control?


----------



## Beefy

Quote: 





w0lfd0g said:


> Are there any disadvantages to making minute controls to volume via source - eg preamp or DAC with a volume control?


 
   
  I try to keep everything at max and use the volume control at the final step. You are less likely to throw out information that way, and get fewer surprises if you accidentally set something wrong. But it depends very heavily on the equipment, software, personal preference, etc.


----------



## W0lfd0g

Thanks Beefy


----------



## Doc B.

FWIW we spent a lot of time and money listening to all the attenuators we could lay hands on last year, for our BeePre preamp. The end result was our own stepped attenuator design, that we felt sounded better than anything we could buy. A spinoff kit from this work is our Submissive passive attenuator and source selector. It is a stand alone volume control that can be used ahead of pretty much any amp. One could use it in front of a Crack and probably hear an improvement over the stock control.


----------



## Dark Helmet

Quote: 





doc b. said:


> FWIW we spent a lot of time and money listening to all the attenuators we could lay hands on last year, for our BeePre preamp. The end result was our own stepped attenuator design, that we felt sounded better than anything we could buy. A spinoff kit from this work is our Submissive passive attenuator and source selector. It is a stand alone volume control that can be used ahead of pretty much any amp. One could use it in front of a Crack and probably hear an improvement over the stock control.


 
  Is it better than a Goldpoint and are they on your website for sale.


----------



## skeptic

FYI - http://www.bottlehead.com/store.php/products/submissive-volumesource-control-kit  The same is also built into the mainline.


----------



## skeptic

Quote: 





amcananey said:


> Well, I've got the Speedball installed, and I also installed a TKD volume pot and 100uf ClarityCap ESA film caps on the output, plus I bypassed the last cap on the power supply, again with a ClarityCap ESA. As for output power, I actually installed a pair of in-line RCA signal attenuators on the inputs on my Crack, since I actually found it had too much gain...
> 
> Oh, and I'm using a GEC straight brown base 6AS7G and I've got a decent selection of driver tubes (12AU7, 12BH7 and E80CC).
> ....


 
   
  I love the photos of the claritycaps you posted on bh, and the risers were a great solution to the size issue!  It would be a lot of fun to hear, and compare back to back, how they stack up against the obbligato axial's I have in mine - particularly given that we are running the same pots and GEC 6as7g.  Do you know if there are any dissipation measurements published on the ESA's?  Diyhifi's short list, and the very favorable comparison to blackgates, was a big part of what sold me on the obbligatos: http://www.diyhifisupply.com/catalog/34  Wish they had a 5% rather than 10% tolerance, but I do think they sound better than the axon's I was previously using.


----------



## Doc B.

"Is it better" needs some definition. The Goldpoints are very good. We designed the Submissive because I felt we could come up with something that I prefer the sound of (or perhaps "the lack of sonic influence of" is a better description) to any of the other attenuators we tried. And I do prefer Submissive. In my room, in my system, in my ears.


----------



## amcananey

skeptic said:


> I love the photos of the claritycaps you posted on bh, and the risers were a great solution to the size issue!  It would be a lot of fun to hear, and compare back to back, how they stack up against the obbligato axial's I have in mine - particularly given that we are running the same pots and GEC 6as7g.  Do you know if there are any dissipation measurements published on the ESA's?  Diyhifi's short list, and the very favorable comparison to blackgates, was a big part of what sold me on the obbligatos: http://www.diyhifisupply.com/catalog/34
> Wish they had a 5% rather than 10% tolerance, but I do think they sound better than the axon's I was previously using.




I don't know if there are published dissipation measurements. To be perfectly honest with you, I'm willing to spend the cash to install quality film caps, but I have neither the patience, nor the ears, nor the budget to try out multiple sets of caps and compare them. I would much rather spend that time either building another amp or listening to music. That's not intended as a slight against anyone who is willing to put in the time and effort and has the requisite golden ear, it's just being honest about my own limitations and where I've decided to draw the line in this disease we all share. 

As for published reviews of how different film caps sound...well, I am deeply skeptical. Even assuming that there are clear differences that 2 (or 10 or 20) different people would agree upon, I suspect that which cap sounds best is highly system dependant and all of the published reviews I've seen (from anyone with some sort of experience/knowledge to back up their opinions) have involved systems that didn't bear any resemblance to my own whatsoever. And to be honest, I tend to doubt that 20, 10 or even 2 people would consistently agree on differences between caps. On top of which, you also have the question of whether the caps being tested have all been fully broken in (to the extent you believe in that sort of thing). 

Why am I so skeptical? Well, I've tried A/B-ing components, and the time it takes me to swap out one component and insert another, then get the music test clip queued up and playing, has rendered any attempt at objectivity meaningless. I simply can't remember what the first clip really sounded like long enough. I can barely do it with tubes. I certainly can't do it with anything that takes longer to swap.

Best regards,
Adam


----------



## amcananey

Three quick notes to add to this thread:

1. Changing volume pots is not a night-and-day difference. Maybe not even a morning-and-afternoon difference. And any differences may well be more imagined than real. I feel the need to repeat that whenever I find myself discussing a tweak that is fairly minimal, lest anyone get the wrong idea. The stock Bottlehead pot is perfectly serviceable and more than up to the task. In a double-blind test, I wouldn't bet on me being able to identify the stock pot vs. my TKD. You can leave the stock pot in and not worry that you're missing out on some great improvement to your Crack

2. If you do want to upgrade the volume pot, an ALPS Blue Velvet pot can be had for about $12-15. There is a reason they are so popular and are used in so many systems, including fairly high-end systems: they sound good. I would never recommend to anyone that they buy a $100 TKD pot over an ALPS. 

3. The best upgrade for a Crack is the Speedball. Everything else is secondary.

Best regards,
Adam


----------



## Beefy

Quote: 





amcananey said:


> Three quick notes to add to this thread:


 
   
  You must be my brother from another mother! Although I would be less diplomatic about those who review caps and think they hear amazifying differences. Great post.
   
  Like you, I really doubt I could pick the TKD out of an audio lineup...... although the reason I went for it anyway is for better channel matching, particularly at low volumes. I've had a couple of amps with Alps Blues that were a 1-2 dB off at the very low end - not so with the TKD.


----------



## amcananey

One thing to remember is that there are two ways to get around poor tracking at low volume levels....(a) replace the stock pot with an expensive pot that tracks better at low levels (though note that stepped attenuators have the best tracking, and the VALab is only $25), or (b) turn the volume up. 

I'm actually serious about (b), not just being a wise-ass. If you install a (relatively) cheap pair of inline RCA attenuators on the inputs, you have a much greater useable range on the volume pot. I use a pair of Harrison Labs attenuators. Go for the highest attenuation level. Anything else is too insignificant to be worthwhile. 

Best regards,
Adam


----------



## elwappo99

Seems this weekend if you buy a Crack kit you get the speedball for fwreeeee .... Any takers?
   
  Seems like a great deal, too bad all my headphones sit in the low impedance category. Anyone have much luck with low impedance cans? Would something like this raise the noise floor enough to make it viable?


----------



## imackler

Quote: 





elwappo99 said:


> Seems this weekend if you buy a Crack kit you get the speedball for fwreeeee .... Any takers?


 
  So wish I were a DIY guy! I thought I was going to try it until I watched Tyll's video. Gotta know when to fold them...
   
  First six orders get a couple tubes: "Order a Crack kit this weekend and get a free Speedball upgrade. That's a $125 savings! Now we know some of you guys are gonna wait until Sunday night to order. But we need your dollars today so we can order all sorts of parts. Sooo, we are going to spice the first six orders up and ship them with an RCA clear top 12AU7 and a triple mica 6080."


----------



## amcananey

1. These are the attenuators I use and recommend: http://www.amazon.com/Harrison-Labs-Line-Level-Attenuator/dp/B0006N41B0/ref=sr_1_1?ie=UTF8&qid=1373666346&sr=8-1&keywords=harrison+labs 

I do NOT recommend trying the 3 dB or 6 dB versions.

2. If you buy the right equipment (which isn't expensive and will serve you well for a long time to come), watch a couple of YouTube videos on soldering, practice soldering for half an hour with some scrap pieces and follow the instructions (which include detailed pictures for EVERY step) carefully and methodically, then ANYONE can build a Crack.

In terms of what qualifies as the right equipment, I recommend the following:

- a basic temperature controlled soldering station (check Amazon or eBay, these are NOT expensive - and a digital display doesn't add anything over analog controls) - this should come with a soldering iron holder and a sponge
- 63/37 leaded solder with a rosin flux core (don't go for lead-free, silver or 60/40 solder
- wire strippers (the kind with holes marked for various wire gauges, it should have holes for 20, 22 and 24 AWG)
- a quality pair of flush-cut wire cutters (these are small, not the kind you use for cutting household electrical wire)
- some solder braid to take care of the inevitable mistakes
- high quality tweezers

[LATER EDIT: I foolishly forgot to mention two of the most important tools!!
1. A digital multimeter, and 
2. Needle-nose pliers (small ones, with a long, thin "nose"). 

You can get a cheap multimeter for $10 and, surprisingly, they actually aren't terrible. I have one that is fairly accurate. But I wound up buying this one for not much more cash and it is a big improvement in readability, ergonomics, convenience and flexibility. Most importantly, you can swap out the probes for ones that have clip leads, which are safer.]

Other things that come in handy: a magnifying glass, a penlight, forceps. I think that's it.

There are four rules when it comes to soldering:

1. FIRST establish a good physical connection, THEN solder in place.
2. Heat BOTH components you are looking to connect equally.
2. Adding a tiny bit of solder to the soldering iron tip before touching the components will help to conduct heat.
3. Add solder by touching the components, not the soldering iron tip. The solder is attracted to heat, and adding solder to cold components will give you a weak, brittle solder connection that will soon break or give you only intermittent contact.

I know soldering sounds difficult intimidating, but the Crack was my first soldering project and it worked the first time. And it sounds phenomenal and was an incredibly satisfying process.

IF YOU RUN INTO ANY PROBLEMS, DON'T GET FRUSTRATED. Post on the Bottlehead forums and the Bottlehead team will respond very quickly with detailed, helpful advice. They provide better service in their forums, then I've had from most places in person or over the phone. And if anything seems unclear, then again just post in the Bottlehead forum and you will get an answer.

You can easily build a Crack in two nights. Three if you go really slow and want to do some practicing first. 

Best regards,
Adam


----------



## captouch

Great post Adam. It was my first DIY as well and it worked the first time. Turns out I had a single cold solder joint that reared its head occasionally, but that was it.

I would just say if you have particularly shaky hands, that could be an issue. Some of that soldering work neat the tube leads with the LEDs isn't for the trembly among us.


----------



## skeptic

FYI - as an alternative to buying inline attenuators, you can simply pad your input by adding 4 resisters as shown: http://www.goldpt.com/mods.html The tables set out the values you want for varying degrees of attenuation.


----------



## amcananey

skeptic said:


> FYI - as an alternative to buying inline attenuators, you can simply pad your input by adding 4 resisters as shown: http://www.goldpt.com/mods.html The tables set out the values you want for varying degrees of attenuation.




Adding resistors definitely works, and it is an approach commonly recommended in the Bottlehead forum. I prefer the attenuators, since they can easily be removed and inserted, especially if you change your source down the line and need the extra gain. No soldering or changes to the stock layout needed. 

Best regards,
Adam


----------



## hedphonz

Quote: 





amcananey said:


> 1. These are the attenuators I use and recommend: http://www.amazon.com/Harrison-Labs-Line-Level-Attenuator/dp/B0006N41B0/ref=sr_1_1?ie=UTF8&qid=1373666346&sr=8-1&keywords=harrison+labs
> 
> I do NOT recommend trying the 3 dB or 6 dB versions.
> 
> ...


 
  thanks for that timely advice Adam,
   
  i just been tempted to buy the crack yesterday through a sweet deal that bottlehead were offering - free speedball upgrade and with premium tubes (though the tubes were only for the first 6 orders)
   
  I havent soldered anything for over 20 years so will be an interesting experience


----------



## howie75

Wow. That is a sweet deal. Too bad I ordered mine a couple of weeks too early.


----------



## ben_r_

Quote: 





howie75 said:


> Wow. That is a sweet deal. Too bad I ordered mine a couple of weeks too early.


 

 Thinking the same thing myself. It was insulting enough as it was paying $125 for less than $10 in parts in the Speedball Kit, and now they are giving it away for free?! Nice.


----------



## walls

ben_r_ said:


> Thinking the same thing myself. It was insulting enough as it was paying $125 for less than $10 in parts in the Speedball Kit, and now they are giving it away for free?! Nice.




I ordered mine a couple weeks ago as we'll, I called Bottlehead and while they were already out of the tubes they were more then happy to add the speedball to me order. Really great people to work with IMO.


----------



## leothan

Really cool , just order the a set as I missed the last promotion , hopefully still can get the free tube  .
   
  anw can I check whether I can use 6SN7 with converter with this amp ? really tempting to see how it 's performance with TS5998 and Sylvania 6SN7 bad boy , they are great with the DV336


----------



## amcananey

leothan said:


> anw can I check whether I can use 6SN7 with converter with this amp ? really tempting to see how it 's performance with TS5998 and Sylvania 6SN7 bad boy , they are great with the DV336




You can. You need an adapter available on eBay. It comes in 6V and 12V versions. You need the 6V version. Be warned, however: in my experience 6SN7s aren't the best match for the Crack. I would stick to 12AU7s and 12BH7s. Others have a different view, of course...


----------



## Utopia

Ordered one on Sunday (with the free Speedball upgrade, but no extra tubes, as far as I know). Shipping by the end of the week or early next.


----------



## walls

I might build mine without the speedball for a while and then add it later to compare. From everything I have read about this amp I should have my old friend the LittleDotII++ up for sale in a few weeks. LOL!


----------



## ffivaz

Quote: 





walls said:


> I might build mine without the speedball for a while and then add it later to compare. From everything I have read about this amp I should have my old friend the LittleDotII++ up for sale in a few weeks. LOL!


 

 It will also be easier to troubleshoot if you first build the stock Crack, and when it works add the speedball.


----------



## mellowbob

Quote: 





utopia said:


> Ordered one on Sunday (with the free Speedball upgrade, but no extra tubes, as far as I know). Shipping by the end of the week or early next.


 
  I ordered mine Friday. Are they shipping that quickly? From reading, it seems like it'd take 2-3 weeks.


----------



## amcananey

amcananey said:


> 1. These are the attenuators I use and recommend: http://www.amazon.com/Harrison-Labs-Line-Level-Attenuator/dp/B0006N41B0/ref=sr_1_1?ie=UTF8&qid=1373666346&sr=8-1&keywords=harrison+labs
> 
> I do NOT recommend trying the 3 dB or 6 dB versions.
> 
> ...



 
 I'm feeling sheepish...I forgot two of the most important tools: 1. A digital multimeter, and 2. Needle-nose pliers (small ones, with a long, thin "nose"). You can get a cheap multimeter for $10 and, surprisingly, they actually aren't terrible. I have one that is fairly accurate. But I wound up buying this one for not much more cash and it is a big improvement in readability, ergonomics and flexibility. Most importantly, you can swap out the probes for ones that have clip leads, which are safer. Best regards, Adam


----------



## Doc B.

Quote: 





mellowbob said:


> I ordered mine Friday. Are they shipping that quickly? From reading, it seems like it'd take 2-3 weeks.


 
  Yes. Some of the first kits ordered on Friday may ship within the next week or so. We have what we felt was a typical month's worth of inventory on hand. But we had such a huge response that we had to call in emergency orders to all of our vendors yesterday and order double our normal quantity, and some of them will take a couple/three weeks to get parts made and sent to us.
   
  Okay, I'd better get back to tracking down parts and brushing panels!


----------



## amcananey

doc b. said:


> Okay, I'd better get back to tracking down parts and brushing panels!



 
 Doc, Any chance you can use this as an opportunity to post a video of you brushing the panels? Doesn't have to be studio quality, it would just be cool to see your technique as I make my own replacement chassis. Even a cellphone video on YouTube would be helpful... Best, Adam


----------



## Doc B.

When we are done with this production crunch I will try to carve out some time to do so.


----------



## fcpchop88

Quote: 





walls said:


> I ordered mine a couple weeks ago as we'll, I called Bottlehead and while they were already out of the tubes they were more then happy to add the speedball to me order. Really great people to work with IMO.


 

 +1 awesome people over there at bottlehead, hopped on this deal too. Can't wait to get started! I think I too will build just the crack first then the speedball after


----------



## hedphonz

Quote: 





fcpchop88 said:


> +1 awesome people over there at bottlehead, hopped on this deal too. Can't wait to get started! I think I too will build just the crack first then the speedball after


 
  cant wait to get started too - been bitten by the tube and tube rolling bug after buying the lyr so having the crack will give me even more tubes to hunt down and buy - great fun


----------



## ULUL

1st post here.  I asked this question on the HD800 appreciation thread, figuring it would be the right place, but got one limited response which I appreciate but was hoping for more.  So I'm here instead - hope it is OK to post. 
   
  Two questions: 
   
  1. Does the Crack w. Speedball do the HD800 sufficient justice so that its strengths are adequately utilized?  i realize that one can well spend north of four figures to maximize the HD800 and that it scales up very well.  However, there is a sense generally that at a certainly level, a piece of equipment is does something justice or not.  Where the line is is subjective of course but I think there's a general concensus that develops after a while. 
   
  2. If I want to have the Crack/Speedball dedicated primarily to the HD800, what other modifications would be recommended where the bang for the buck return for the additional cost is high?  Or should one just stay stock? 
   
  Thanks in advance for any help. 
UL


----------



## mikek200

Quote: 





ulul said:


> 1st post here.  I asked this question on the HD800 appreciation thread, figuring it would be the right place, but got one limited response which I appreciate but was hoping for more.  So I'm here instead - hope it is OK to post.
> 
> Two questions:
> 
> ...


 
  definetly get the speedball upgrade,thats the biggie
  Others will chime in about the v-caps..??


----------



## Draygonn

ulul said:


> 1st post here.  I asked this question on the HD800 appreciation thread, figuring it would be the right place, but got one limited response which I appreciate but was hoping for more.  So I'm here instead - hope it is OK to post.


Crack with Speedball does a great job with the HD800s. Find tubes you like and you're in for a wild ride.


----------



## amcananey

Check my profile for all of the headphones and amps I have tried (actually, I've tried more, but there is a character limit on profiles, so I had to stop adding more reviews). The Crack + Speedball is the best amp for the HD800 I have ever heard, bar none. In fact, I would argue there is nothing close, even for several times the price. (One exception is the Little Dot Mk VI+, but I have had problems with mine, and the large number of tubes means it is a very, very finicky amp to run.) 

Get the Speedball. All other "upgrades" are optional. I installed ClarityCap ESAs in mine. I would go for an Alps Blue volume pot at a minimum. If you don't mind a stepped attenuator, I would go for a Vintage Audio Lab (VALab on eBay) "ladder-style" stepped attenuator, which probably offers the best price/performance ratio imaginable. 

But really, all you need is the Speedball and you will be in heaven. 

Best regards,
Adam


----------



## tdogzthmn

I have a genuine Telefunken 12au7 sitting around... might be time to build myself another Crack so I can hear what this tube can do. Anyone have experience with one and can comment on the sound?


----------



## W0lfd0g

IMO it is a waste of time and money to roll driver tubes (12AU7 Et al) if you have the Speedball installed.

I have tried three flavours of NOS Telefunken, and they sounded no different to me to some ECC82 Mullards, RCA, Mazda Siemens, Tung Sol and others. Try rolling the output tube. Much more beneficial.


----------



## tdogzthmn

I do remember the Output tube having a big impact on the sound and performance of the amp. The 5998 was the favorite of the tubes I owned at the time. Luckily for me I was given the tube so it didn't cost me anything.


----------



## ULUL

Adam, a few quick points: 1. Thanks for your reply to my query. 2. I checked your profile. Yowzer - that's quite an impressive list. 3. Given your experience, your comment about the combo is very reassuring and it is possible that my end point is the HD800 and Crack/Speedball and I'm done. Thank you. Much grateful. UL  


amcananey said:


> Check my profile for all of the headphones and amps I have tried (actually, I've tried more, but there is a character limit on profiles, so I had to stop adding more reviews). The Crack + Speedball is the best amp for the HD800 I have ever heard, bar none. In fact, I would argue there is nothing close, even for several times the price. (One exception is the Little Dot Mk VI+, but I have had problems with mine, and the large number of tubes means it is a very, very finicky amp to run.)
> 
> Get the Speedball. All other "upgrades" are optional. I installed ClarityCap ESAs in mine. I would go for an Alps Blue volume pot at a minimum. If you don't mind a stepped attenuator, I would go for a Vintage Audio Lab (VALab on eBay) "ladder-style" stepped attenuator, which probably offers the best price/performance ratio imaginable.
> 
> ...


----------



## Draygonn

w0lfd0g said:


> IMO it is a waste of time and money to roll driver tubes (12AU7 Et al) if you have the Speedball installed.


I had a different experience. I used to switch driver tubes between Electro-Harmonix 12AU7 for HD650s and JJ ECC82 for HD800s. The JJ ECC82 was too dark for the HD650s but gave a nice sweetness to the 800s.



tdogzthmn said:


> The 5998 was the favorite of the tubes I owned at the time. Luckily for me I was given the tube so it didn't cost me anything.


Lucky you. I love the 5998s. I bought 4 and 2 died the first year.


----------



## W0lfd0g

Quote: 





draygonn said:


> I had a different experience. I used to switch driver tubes between Electro-Harmonix 12AU7 for HD650s and JJ ECC82 for HD800s. The JJ ECC82 was too dark for the HD650s but gave a nice sweetness to the 800s.
> Lucky you. I love the 5998s. I bought 4 and 2 died the first year.


 
   






  He he - Obviously I have a set of brittle alloy ears compared to the golden ears around here.  Oh well - I can save my tube money for something else.  Viva la difference.


----------



## Cryok95

Quote: 





tdogzthmn said:


> I have a genuine Telefunken 12au7 sitting around... might be time to build myself another Crack so I can hear what this tube can do. Anyone have experience with one and can comment on the sound?


 
   
  Some may kill me for saying this but i prefer the 12au7 amperex bugle boy... slightly smoother presentation with foot-tapping bass


----------



## Draygonn

Can the Crack be used as a pre-amp for active speakers? I got a pair of Emotiva Airmotiv 4s for my computer setup. I'm curious to see what they would sound like with some tube goodness and I happen to have a cable with 1/4" jack into RCAs laying around.


----------



## amcananey

It certainly "can" be. In terms of whether it sounds good...well, why not try it and find out? You won't harm anything (assuming you start with the volume turned down and work your way up). Pay particular attention to the quality of the bass during your test.


----------



## ULUL

Curious.  How is the "RCA clear top 12AU7 and a triple mica 6080" better than what is supplied with the Stock crack kit?
   
Thanks,
UL


----------



## brunk

ulul said:


> Curious.  How is the [COLOR=454545]"[/COLOR]RCA clear top 12AU7
> and a triple mica 6080" better than what is supplied with the Stock crack kit?
> 
> 
> ...


 I ordered an RCA clear top, but im waiting on my kit to arrive


----------



## Draygonn

amcananey said:


> It certainly "can" be. In terms of whether it sounds good...well, why not try it and find out? You won't harm anything (assuming you start with the volume turned down and work your way up). Pay particular attention to the quality of the bass during your test.


I used a switchbox to test direct and through the crack. Very little difference, largest being a slight imaging change. My curiosity is now satisfied.


----------



## FlySweep

ulul said:


> Curious.  How is the [COLOR=454545]"[/COLOR]RCA clear top 12AU7
> and a triple mica 6080" better than what is supplied with the Stock crack kit?
> 
> 
> ...




I have a RCA "curved black plate w/ horseshoe getter" 12BH7.. it's fantastic! .. and sounds better (cleaner, more dynamic, better detailed, and quieter) than any of the RCA 12AU7s I've heard (in the Crack). I actually prefer 12BH7s in general & can't go back to listening to _any_ 12AU7s in the Crack. Considering the that "better" 12AU7s cost an arm and a leg these days.. and that even the average 12BH7 tubes are generally considered to sound better than even some of the best 12AU7s.. and that the 12BH7s are cheaper.. and that 12BH7s are much quieter/less microphonic.. it's a bit of a no brainer, to me. Do note, you need to have the Speedball installed in order to run 12ABH7 tubes.

I've got a couple of 6SN7s (Sylvania VT-99 & Raytheon VT-231).. but the 6SN7 adapter I just got (via eBay/China) appears to be defective


----------



## FlySweep

False alarm on the 6SN7 adapter.. looks like it works just fine, actually... perhaps it was the VT-99 I tried that was the issue. The Raytheon VT-231 arrived today so I promptly rolled it in with the adapter..

HOLY. SMOKES.

What a lovely sound!

It takes all the things I love about the better 12BH7s and "kicks it up a notch." Thing I noticed first was even better dynamics and what seems like an even lower noise floor. The better 12BH7 I've heard hardly leave me wanting when it comes to resolution.. but incredibly, the VT-231 seems to top that. Tonal reproduction is terrific, as well. It's a wonderfully smooth, airy, neutral tube. Bass is lean, mean, and fast.... but has excellent punch and impact when the music calls for it. The mids are very transparent, detailed, and spacious. Smooth, detailed, and possessing terrific depth, the mids are nothing short of jaw droppingly good. Treble, too is, perfect for my tastes. Not recessed, not excessively bright.. but balanced, extended, crisp, and smooth. There's a romantic quality to this tube's sound that makes me want to keep listening with the HD800.

To date, this is my favorite to in the Crack. Simply wonderful... and what sounds like a match-made-in-heaven with the HD800.

..VT-99 tomorrow..


----------



## ULUL

Quick question on DACS for the Crack/Speedball to be matched with the HD800. I am considering one of two DACS that are on the same level - one is more neutral/detailed while the other slightly more romantic/warm and possibly a hair behind in detail. Would there be a general concensus on which type of DAC is better with an OTL like the Crack/Speedball combo? Thanks, UL


----------



## walls

I have not received my crack yet but my WA2 is an OTL amp and it pairs quite nicely with my Bifrost with the Uber upgrade. Adds a nice amount of upper end clarity with a very nice bottom end punch. 

Hopefully I will get my Crack and build it soon enough then I will be able to give impressions on it with the Schiit.


----------



## amcananey

ulul said:


> Quick question on DACS for the Crack/Speedball to be matched with the HD800. I am considering one of two DACS that are on the same level - one is more neutral/detailed while the other slightly more romantic/warm and possibly a hair behind in detail. Would there be a general concensus on which type of DAC is better with an OTL like the Crack/Speedball combo? Thanks, UL




1. FWIW, Bottlehead is on the verge of releasing its own DAC, in case you want to go for an all-Bottlehead setup. No word on price or timing, but it will be announced fairly soon.

2. The Crack is definitely on the fast and slightly bright end of the spectrum. Prior to buying the Crack, I thought I preferred "warm", "lush" and "tubey" amps. I was wrong. The speed and detail of the Crack is absolutely addictive. Everything else sounds muddy by comparison. So.....you have two options: (1) go for the neutral/detailed DAC to get more of a good thing, or (2) go for the warm/romantic DAC with the goal of tempering the Crack's natural tendencies. I would go for option (1), without question, but everyone has a different view. 

Best regards,
Adam


----------



## FlySweep

mink70 said:


> I've owned a Crack that I bought from a fellow Head-Fier for several weeks, and I have to say that my initial impression with the HD800 and HD650 was not great. Compared to my JDS Labs  portable C421 op-amp powered unit (about $170), the Crack sounded bassy, rolled off on top, slow and lacking in detail—poky and boring. This was with a Sylvania 12BH7 driving a Tung Sol 6080. What I've discovered since is that the Crack is more responsive to tube rolling than any piece of equipment I've ever heard. Which is to say, unbelievably so.
> 
> Since then: I tried plenty of 12AU7s—Telefunken (my fave), Amperex bugle boy and globe, Mullard, RCA cleartop, EH Russians—then tried 12BH7s. Among those, RCA long black plate was best, with a clear, analytical, extended sound. So I got the Chinese adapter and tried a Sylvania brown-base 6SN7GT. The sound came alive for the first time. Dynamic, involving. Then the Tung Sol 5998 (actually a Chatham 2399) arrived, which I liked a lot. More air, bigger soundstage, easier, more fun. But it didn't love the Sylvania. So I tried all the input tubes again. The 12AU7s were okay (the cleartop sounded nice, but very midrangey and rolled), the RCA 12BH7, again, offered an incredibly detailed and wide-band sound, but a little cold and uninvolving.
> 
> ...




I wanted to bring this fantastic post back to the front of the thread.. cause it perfectly captures what I'm hearing from the Raytheon VT-231. From a technical & musical perspective, the Raytheon VT-231 is one of the most _complete_ sounding tubes I've heard.. in the Crack or elsewhere. It's nothing short of _breathtaking_ and the HD800 sounds criminally good with it. I presume it'll sound just as good with the HD600/650, too. I love my 12BH7 tubes (faves being the Amperex 6085, Tungsram E80CC, and an (early 1950s) RCA "curved black plate w/ a horseshoe getter").. but if they were somehow (unfortunately) whisked away at this very moment.. I wouldn't shed a single tear. Where it comes out ahead of even the better 12BH7s (I've owned) is articulation and refinement at the edges of the freq spectrum, soundstage, resolving ability, and clarity. I'm not even going to bother making comparisons to 12AU7s.. it makes them sound like "Fisher Price" tubes (personally speaking, of course.. and no, I'm not exaggerating).

The Raytheon's VT-231's bass is tight, clean, extended, speedy. It textures with excellent precision and offers just the perfect punch when the music calls for it. The midrange is, undoubtedly, a show stealer. It's spacious, incredibly detailed, vibrant, clear, and possesses wonderful tonal purity. All this is presented in an impeccably smooth, liquid manner. Vocals have a naturally effortless quality in the way they're presented.. as if they're "suspended" in space. You're delicately surrounded and immersed in the music in such a natural manner. To use an old cliche.. I'm hearing plenty of things in records (I've listened to a thousand times) that I "never knew existed before".. or if I knew such details existed, I haven't heard them with the kind of clarity and accuracy I'm hearing now. The treble in no way, takes a backseat to the bass and midrange.. as it carries over a lot of the same qualities of the midrange.. smooth, detailed, even, and very resolving.. but never piercing, fatiguing, or harsh.

I could go on an on about this tube.. but I've already taken up enough of your time. it's an 'end game' level tube for me, as far the the BH Crack/HD800 combo is concerned. Mink70 said it best: "A sound so compelling it's almost mysterious."


----------



## ULUL

Alert: OT...OT....Off Topic....
	

	
	
		
		

		
			




   
  But it is related in a sense.  Hope I don't offend anyone with this query. 
   
  Is there a tube amp for speakers that is equivalent to the Crack?  In short, the Crack is DIY, highest performance to cost ratio, and has incredibly excellent documentation along with a great community around it. 
   
  However, Crack is for headphones. Is there an equivalence for tube speaker amps? i figure if any would know, it would be this community.  
   
  Thanks!
 UL


----------



## hedphonz

Quote: 





ulul said:


> Alert: OT...OT....Off Topic....
> 
> 
> 
> ...


 
  www.bottlehead.com has a range of them


----------



## dsound

@ ULUL  PM'ed you.


----------



## GaryPham

Does anyone know if the Bottlehead crack will come with free speedball again anytime soon?  I totally dawdled around the deal couple of weeks ago and am totally kicking myself now for not jumping aboard after hearing it at a meet. T.T


----------



## Doc B.

That kind of sale - that is, that deep of a discount - happens only once in a great while. It started with us kicking around the idea of a "Xmas in July" thing. We had no idea how huge it would turn out to be. Probably losing money on every sale, but I guess we'll make up for it in volume...Anyway, we do not have any set pattern for any sale pricing. It simply happens when a combination of things comes together in just the right way. I can say that the free Speedball sale in specific will not happen again any time in the foreseeable future.


----------



## fcpchop88

Quote: 





doc b. said:


> That kind of sale - that is, that deep of a discount - happens only once in a great while. It started with us kicking around the idea of a "Xmas in July" thing. We had no idea how huge it would turn out to be. Probably losing money on every sale, but I guess we'll make up for it in volume...Anyway, we do not have any set pattern for any sale pricing. It simply happens when a combination of things comes together in just the right way. I can say that the free Speedball sale in specific will not happen again any time in the foreseeable future.


 
   
  Sorry to hear you guys aren't making money off those sales. Kinda makes me feel guilty but I'm stoked for my crack w/speedball kit to get here! Certainly will be like Xmas in July


----------



## caracara08

I am very excited as well. This is the end of the road desktop amp for me. It will be great not feeling I am missing out on anything by not upgrading.


----------



## DefQon

Great amp for sure. Despite mine enclosure-less, enjoying it every minute I listen to them with the 600's.


----------



## RedBull

Has anyone any impression comparison of Crack and CSP2+ and Taboo mkiii? Please forget the price at the moment, just sound signature alone, as I don't always believe price = quality.


----------



## amcananey

Well...I'm not really sure what you are asking be compared. The appropriate comparison would be between the Crack and the CSP2+. The CSP2+ is an OTL headphone amplifier. Like the Crack, it is best suited for high-impedance headphones. The Taboo is a WOT amp better suited for low impedance headphones. The Taboo is most directly comparable to the Bottlehead S.E.X. 2.1. I have a Crack + Speedball, a Taboo mk II and a S.E.X. 2.1 kit that I haven't built yet. Since I don't have a CSP2+, I can't answer the question that I suspect is most relevant for your purposes (i.e., how do the CSP2+ and Crack compare?). Nor can I give you a direct comparison of how the Taboo and the S.E.X. 2.1 compare. But here are a few general comments: 1. Decware recommends that you use a preamp with the Taboo mk II (I don't remember whether they removed this recommendation for the mk III). This isn't an idle recommendation. At least with my HiFiMAN HE-6s, the Taboo quickly ran out of gas when used without a preamp, even though my source put out a nominal 2 VRMS signal. I bought and built a Bottlehead Quickie preamp ($99) for use with the Taboo, and it is indeed much improved now. (I've been told the S.E.X. v. 2.1 does not need any sort of a preamp, even for use with the HE-6.) 2. The Taboo is optically much nicer looking than the Bottlehead products in the form shipped, although the Bottlehead products make customization easy, so the sky is the limit. You can make your amp as nice as you want to. 3. The Taboo is freakin' huge. I thought I would like that before I bought it. Now that I have it, I find it a PITA. It is very, very deep, so it can't be put on most shelves. It really needs a tabletop surface of its own. 4. The Taboo's power switch has got to be in the most annoying place possible. It is all the way toward the back of the amp, sandwiched between the IEC plug and the transformer. I have big hands and I find it incredibly annoying to reach in there. 5. The Taboo uses 4 tubes. If my experience with various tube amps has taught me anything, it is this: tubes can be finicky and a royal PITA to deal with. Sure, the sound is wonderful, and I use my tube amps more than my solid state amps, but the more tubes you have, the more opportunity there is for something to go wrong. The pictures of amps with lots of beautiful glowing tubes used to make me envious. Now I look at them and just think: you will never be able to enjoy that amp, because you will spend all your time trying to find tubes that work, and work well together. Then one will act up and you will be out of commission until you can secure a replacement... The S.E.X. only uses 2 tubes. 6. The Taboo has more features. I won't go into all of the details, but it has more jacks, more connections, more adjustments, etc. I haven't found any amp, even amps I've owned that cost over $2k, that can beat the Crack + Speedball when paired with my HD800s. The Taboo sounds excellent with my HE-6s, but I have a little bit of noise with mine that I can't seem to eliminate. I don't know whether it is due to the fact that I'm using a different source than I use with my Crack, or whether I have a tube issue, or whether I need still more preamplification, or whether there is something wrong inside my Taboo itself, but I sometimes have some crackling/static that I can't fully eliminate. After I build my S.E.X. 2.1, I will compare it to the Taboo, and sell whichever one I like less. Given my experience with Bottlehead products so far, I suspect the Taboo will be the one I sell. In light of the cost difference, the room for customization and the amazing sound, I would recommend the Bottlehead products over the Decware products. That's not intended as a slight against Decware, it's just that I think Bottlehead offers great products at great prices and the process of building your own amp is extremely rewarding. You can use the cost savings compared to the Taboo products to buy a stepped attenuator, boutique film caps, extra tubes, upgraded chassis hardware, etc. And still have lots of money leftover. BTW, I don't know if it has enough power for HE-6s, but you might want to consider the Bottlehead Mainline instead of a Crack + S.E.X. or a CSP2+ & Taboo. According to the Bottlehead team, the Mainline is superior to both the Crack and the S.E.X. I will eventually build a Mainline, but I doubt I will ever sell my Crack. It is THAT good with the HD800s. Best regards, Adam


----------



## GaryPham

So I'm about to order a Bottlehead crack to accompany my hd650s. Pretty excited about that. Problem is that I have a couple other headphones which are low impedance. Was thinking of buying a resistance adapter plug to increase the impedance on them. Should that work or would that screw up up the free response? (thinking of picking up a 250ohm adapter to use with my mdr1rs and xba3s.


----------



## amcananey

Gary, I can't explain the technical details, but my understanding is that impedance adapters are largely a gimmick that don't really work (at least not in the sense of negating the negative effects of using low-impedance headphones with an OTL tube amp). That said, I still think the Crack is worth buying, even if only for use with your HD650s. And you can always try your low impedance headphones with the Crack. It isn't as though they won't work at all, the combo just won't be optimal, with reduced power output and some rolled-off bass. Even so, some people quite enjoy their low impedance headphones out of the Crack. Best regards, Adam


----------



## ben_r_

Yea seriously, I bought it JUST for my HD-650's. I have other amps better matched for other headphones, but for the HD-650's the Crack is were its at.


----------



## RedBull

amcananey said:


> Well...I'm not really sure what you are asking be compared. The appropriate comparison would be between the Crack and the CSP2+. The CSP2+ is an OTL headphone amplifier. Like the Crack, it is best suited for high-impedance headphones. The Taboo is a WOT amp better suited for low impedance headphones. The Taboo is most directly comparable to the Bottlehead S.E.X. 2.1. I have a Crack + Speedball, a Taboo mk II and a S.E.X. 2.1 kit that I haven't built yet. Since I don't have a CSP2+, I can't answer the question that I suspect is most relevant for your purposes (i.e., how do the CSP2+ and Crack compare?). Nor can I give you a direct comparison of how the Taboo and the S.E.X. 2.1 compare. But here are a few general comments: 1. Decware recommends that you use a preamp with the Taboo mk II (I don't remember whether they removed this recommendation for the mk III). This isn't an idle recommendation. At least with my HiFiMAN HE-6s, the Taboo quickly ran out of gas when used without a preamp, even though my source put out a nominal 2 VRMS signal. I bought and built a Bottlehead Quickie preamp ($99) for use with the Taboo, and it is indeed much improved now. (I've been told the S.E.X. v. 2.1 does not need any sort of a preamp, even for use with the HE-6.) 2. The Taboo is optically much nicer looking than the Bottlehead products in the form shipped, although the Bottlehead products make customization easy, so the sky is the limit. You can make your amp as nice as you want to. 3. The Taboo is freakin' huge. I thought I would like that before I bought it. Now that I have it, I find it a PITA. It is very, very deep, so it can't be put on most shelves. It really needs a tabletop surface of its own. 4. The Taboo's power switch has got to be in the most annoying place possible. It is all the way toward the back of the amp, sandwiched between the IEC plug and the transformer. I have big hands and I find it incredibly annoying to reach in there. 5. The Taboo uses 4 tubes. If my experience with various tube amps has taught me anything, it is this: tubes can be finicky and a royal PITA to deal with. Sure, the sound is wonderful, and I use my tube amps more than my solid state amps, but the more tubes you have, the more opportunity there is for something to go wrong. The pictures of amps with lots of beautiful glowing tubes used to make me envious. Now I look at them and just think: you will never be able to enjoy that amp, because you will spend all your time trying to find tubes that work, and work well together. Then one will act up and you will be out of commission until you can secure a replacement... The S.E.X. only uses 2 tubes. 6. The Taboo has more features. I won't go into all of the details, but it has more jacks, more connections, more adjustments, etc. I haven't found any amp, even amps I've owned that cost over $2k, that can beat the Crack + Speedball when paired with my HD800s. The Taboo sounds excellent with my HE-6s, but I have a little bit of noise with mine that I can't seem to eliminate. I don't know whether it is due to the fact that I'm using a different source than I use with my Crack, or whether I have a tube issue, or whether I need still more preamplification, or whether there is something wrong inside my Taboo itself, but I sometimes have some crackling/static that I can't fully eliminate. After I build my S.E.X. 2.1, I will compare it to the Taboo, and sell whichever one I like less. Given my experience with Bottlehead products so far, I suspect the Taboo will be the one I sell. In light of the cost difference, the room for customization and the amazing sound, I would recommend the Bottlehead products over the Decware products. That's not intended as a slight against Decware, it's just that I think Bottlehead offers great products at great prices and the process of building your own amp is extremely rewarding. You can use the cost savings compared to the Taboo products to buy a stepped attenuator, boutique film caps, extra tubes, upgraded chassis hardware, etc. And still have lots of money leftover. BTW, I don't know if it has enough power for HE-6s, but you might want to consider the Bottlehead Mainline instead of a Crack + S.E.X. or a CSP2+ & Taboo. According to the Bottlehead team, the Mainline is superior to both the Crack and the S.E.X. I will eventually build a Mainline, but I doubt I will ever sell my Crack. It is THAT good with the HD800s. Best regards, Adam




Thanks for the detailed comparison, Adam, it's really useful.
What I want to know is actually just sound signature alone, regardless the price difference and amp design (I don't care it's OTL or OT), not quality, as quality can be very subjective.
Why I am comparing Taboo with Crack is because:
+ Crack has so many positive reviews, very sheldom I heard bad ones, and I kinda like the look too.
+ Taboo esp mk iii, has a cool looking too, with 2 meters in the front. And I think now the master volume control is in the front? (Correct me if I am wrong). It also can generate 1.7 watt all range from 50 to 300 ohms. And mk iii is now specially designed for headphone, I heard it doesn't need pre amp anymore.
+ csp2+ is also known to have good synergy with 800. I am aware it's an OTL, hence may have low power for orthos, I am optimizing my 800 for now.

I had OTL before, dv337. While it sounds terrific with HD650, the bass is sufficient, butt rather not very firm. So I am wondering if crack (as OTL) also inherited similar character by design.


----------



## GrindingThud

Although a resistive adapter may be a gimmick, adding real output transformers is not. The Mad Ear amp uses the Hammond 119DA in the design. I put a pair on the WA3 and it drives low impedance phones quite well. 
http://www.head-fi.org/t/652270/output-coupling-cap-and-transformer-mod/15#post_9211384
Now, it's not OTL any more, and it alao changes the sound characteristics of the amp. I've never listened to the Mad Ear, but I bet you would not be able to tell the two apart using the same output transformers and similar OTL driver.



amcananey said:


> Gary, I can't explain the technical details, but my understanding is that impedance adapters are largely a gimmick that don't really work (at least not in the sense of negating the negative effects of using low-impedance headphones with an OTL tube amp). That said, I still think the Crack is worth buying, even if only for use with your HD650s. And you can always try your low impedance headphones with the Crack. It isn't as though they won't work at all, the combo just won't be optimal, with reduced power output and some rolled-off bass. Even so, some people quite enjoy their low impedance headphones out of the Crack. Best regards, Adam


----------



## amcananey

If you are optimizing for the HD800, I think it is an easy choice: the Crack. With the Crack, the HD800's bass is hard-hitting and incredibly tight. I find the bass on the HD800s sounds completely different out of the Crack compared to other amps I've tried. It is just so much more solid than with other amps. 

As for sound signature, the Crack is incredibly clean and natural, very fast, great dynamics, with a hint of sparkle, but not in a bad way at all. The Taboo is more romantic, mellow and sweet. While that sounds good, with the HD800s I easily prefer the Crack + Speedball. The Crack + Speedball combo is also much better at detail retrieval than the Taboo.

Even if the Crack + Speedball cost as much as the Taboo (thankfully it does not, and actually only costs a fraction of the Taboo), I would prefer the Crack + Speedball with the HD800s. If you are looking at using other headphones, there is no question the Taboo is more flexible (although in that case, if you are considering the Taboo you should also consider the S.E.X. 2.1), but for the HD800s, the Crack + Speedball is the best I've heard. 

Best regards,
Adam


----------



## EraserXIV

Adam, what's your preferred tube setup with the HD800?


----------



## amcananey

I'm using a Brimar 12BH7 and a GEC 6AS7G. I'm not claiming the GEC imparts any particular magic, I like it because it is dead quiet. I also like the Bendix 6080s with graphite plates, which are much, much cheaper. But although I've tried a variety of 12AU7s, 12BH7s and E80CCs as input tubes, and a variety of 6080s, 6AS7Gs and 5998s as the power tubes, I haven't found a tube yet that didn't sound good. And by good I mean great! 

Best regards,
Adam


----------



## FlySweep

amcananey said:


> I haven't found a tube yet that didn't sound good.


 
   
  I've noticed this as well. In my Speedballed Crack, I've rolled a fair number of the same tubes families Adam has (and just now dipping my toes in the 6SN7 waters).  I've yet to find a tube that sounds bad or even average.. everything I've rolled sounds good (and this is with me listening to the ultra-revealing HD800).. and some sound incredible... though, a big part of what's "incredible" is personal preference, too.  One thing I will say.. I would skip the 12AU7 family entirely.. 12BH7 and/or 6SN7 is the way to you (for me, anyways).
   
  As far as output tubes.. 5998 is the way to go.. if you can get your hands on a Bendix 6080 w/ slotted graphite plates, it's quite nice as well.
   
  Adam.. is the GEC worth the premium over the 5998, IYO?


----------



## ULUL

Adam,  you've been absolutely wonderful in your private messaging help regarding the Crack. (Flysweep, also much grateful for your help.)
   
  I read your comment about how the Crack impact the HD800 with great interest.  My mainstay is HD650 and ZMX T50RP as I mentioned to you.   I am using a neutral detailed solid state amp with a good DAC.   I auditioned a HE-500 extensively last week and was very very impressed though I did not keep it and passed it on to the next guy who is ecstatic to have it.  With the HE-500, there's just an incredible sense of transparency/detail, speed and sweetness.   I thought it was significantly better than the HD650 in those department.    After many hours with the HE-500, the HD650 did have a nice contrasting warmth or the 'warm yummy baby blanket' factor - but only for a bit.  (I know, I may be banned from head-fi for that analogy... 
   
  I'm now auditioning a HD800 and find that, for some reason, i did not have the sense of the immediate transparency or bass that I had with the HE-500.  In all the HD800 has good clarity and large coherent soundstage.  But not very emotionally involving.  I realize that others have said this for their rigs so this is not a surprise. 
   
  BUT I am hoping that the Crack/Speedball would add the sense of involving romance/warmth that I'd love to have, while keeping the larger soundstage that I was missing in the HE-500 and the main reason for giving it a pass.  
   
  This is subjective but your comment does give hope.  I really like large soundstage with headphones and the HD800 has the largest of them all. Just need more of the weight/warmth/romance/sweetness. 
   
  UL
   
   
   
  Quote:


amcananey said:


> If you are optimizing for the HD800, I think it is an easy choice: the Crack. With the Crack, the HD800's bass is hard-hitting and incredibly tight. I find the bass on the HD800s sounds completely different out of the Crack compared to other amps I've tried. It is just so much more solid than with other amps.
> 
> As for sound signature, the Crack is incredibly clean and natural, very fast, great dynamics, with a hint of sparkle, but not in a bad way at all. The Taboo is more romantic, mellow and sweet. While that sounds good, with the HD800s I easily prefer the Crack + Speedball. The Crack + Speedball combo is also much better at detail retrieval than the Taboo.
> 
> ...


----------



## amcananey

As far as I'm concerned, there is no contest between the HD800 and HD650. Heck, I even like the HD600 better than the HD650 by a fair margin, and I've owned three pairs of HD650s. I won't say that the Crack will turn the HD800s into HD650s (thank God), but you certainly haven't seen what the HD800s (or HD650s, for that matter) can do until you have heard them with the Crack. Sennheisers don't do particularly well with solid state amps, in my experience. They don't sound BAD, mind you, but once you have heard them out of the Crack there is no going back.

If you still don't like the HD800s with the Crack, you can try the Anaxilus (spelling?) mod, which is reversible. I'm in 7th heaven with my HD800s as-is, so I've never tried it.

FWIW, I've owned the HE-500s, and they, together with the HD600s, are my favorite budget Summit-Fi headphones. I know some will argue that the HD600s aren't Summit-Fi, but I disagree, provided they are properly amped. Both the HE-500 and the HD600 offer phenomenal performance for their price. In my opinion, both are easily better than the LCD-2s, Beyer T1s, HD700s, etc. Still, they aren't the best there is. While significantly more expensive, the HD800s are better, as are the HE-6s. The Crack is my end-game amp for the HD800s. I'm still surveying the field for my favorite amp for the HE-6s. I've tried many amps, and found many that work very, very, VERY well (the HE-6s aren't as hard to drive as everyone likes to claim), but I suspect the best is yet to come.

Best regards,
Adam


----------



## captouch

They're not as common, but you may want to try the HE-5LE's. At one point, I had the HE-500, HE-5LE, DT-880/600, and HD650. I kept the HE-5LE and HD650 as the most complementary and preferred (by me). The HE-5LE has more sparkle/highs than the 500 and isn't as 'dense', though the mids aren't as sweet. Depends what you like, but a few people have thought the 5LE was closest to the HE6, though not scaling as high of course.

Adam, have you tried the 5LE and if so, your thoughts?


----------



## amcananey

captouch said:


> They're not as common, but you may want to try the HE-5LE's. At one point, I had the HE-500, HE-5LE, DT-880/600, and HD650. I kept the HE-5LE and HD650 as the most complementary and preferred (by me). The HE-5LE has more sparkle/highs than the 500 and isn't as 'dense', though the mids aren't as sweet. Depends what you like, but a few people have thought the 5LE was closest to the HE6, though not scaling as high of course.
> 
> Adam, have you tried the 5LE and if so, your thoughts?




I have not. I briefly owned the HE-400s, but I hated those. Well, hate is probably too strong, but I never warmed to them in the least...

I've owned the DT-990s, DT-880s, DT-770s, T1s and the DT1350s. Of that bunch, I liked the DT990/600 Ohm the best by a mile, and they are the ones I still have. The T1s are wildly overpriced and kind of boring, nowhere close to the HD800s. The DT880s were too thin and brittle sounding for my tastes. The DT770s were fun, but kind of flabby. At the time I owned Denon D5000s and they easily beat the DT770s. I've since upgraded to Denon D7000s. Two other great options for bass-heavy cans are the Ultrasone Signature DJs and the ... well, I own them, but I forget what they are called. M100s, maybe? Both have a similar sound signature. Oddly enough, I do own a pair of Darth Beyers, which are based on the DT770 / 80 Ohm, and I love those. Whatever mods go into those, they really work.

Best regards,
Adam


----------



## amcananey

V-Moda M100s. That's the other pair of bass-heavy cans I was trying to remember. Tons of fun, but ultimately one-trick ponies. The D7000 is much better rounded.

FWIW, I have to lob in a recommendation for the best headphones nobody has ever tried: the Ultrasone Signature Pros. They come within spitting distance of the HD800s in a set of closed cans. In my book, that is actually a way more impressive feat from a technical perspective than even the HD800s. I put the Signature Pros on the same level as the HD800s, the HE-6 and the K1000s (another one trick pony, but MAN, what a trick it is!!!). The HD600s and HE-500s are just a step below those. And a half-step behind them I would list the D7000s, the Darth Beyers and the Kenwood KH-K1000s (another great headphone nobody seems to know very well).

Best regards,
Adam


----------



## captouch

Yeah, I ultimately concluded the DT880/600's were too thin and brittle as well. They never got any headtime once I had the others. 

But I do enjoy the HD650's on the Crack, and the HE-5LE (on Hifiman EF5 or vintage receiver) provides a nice complement depending upon music and mood.


----------



## amcananey

The Crack is pretty much the ultimate antidote for the HD650s weaknesses. It is fast, detailed, and has a touch of sparkle, where the HD650 can be slightly slow, muddled and lacks sparkle. I don't mean to slam the HD650s, they are still very good, and especially so when paired with the Crack. I'm just miffed at Sennnheiser for introducing them at a price point above the HD600s even though I think they are a step down.


----------



## GaryPham

What DAC are you guys running with the bottlehead?  Anyone using the Hifimedy Sabre ESS9023 with it??  How is the pairing?


----------



## uzi

Quote: 





garypham said:


> What DAC are you guys running with the bottlehead?


 
  I was running the HRT Musicstreamer II ... then upgraded to the HRT Musicstreamer II+.  The MSII is very similar sounding to the ODAC (I compared)... decent, but not earth-shattering.  The MSII+ is a noticeable improvement over them, and I'm very happy with it for the price.  I tried the Bifrost Uber at the LA meet last weekend... it's a slight step up from the MSII+, but not as drastic as the MSII to the MSII+.


----------



## DefQon

Odd, I found the Crack + HD600 a supreme orgasmic pairing. This pairing with "special tubes" in place of the usual 6AS7 and 12AU7 suspects, my HD600 sounded better than I had it on my b22, few other OTL designs and the Woo line of amps up to the WA22 it was about on par. I never found anything special about the HD800 + Crack pairing maybe bit romantic sounding but was about it, the Crack's lush sound glossed over the HD800 detail revealing characteristics at times.


----------



## Beefy

Quote: 





flysweep said:


> I've noticed this as well. In my Speedballed Crack, I've rolled a fair number of the same tubes families Adam has (and just now dipping my toes in the 6SN7 waters).  I've yet to find a tube that sounds bad or even average..


 
   
  I'm not a fan of the 12BH7. I have tried three different examples, and they were all a bit slow and bloated compared with the 12AU7 variants I've had. My favourite is still the new production JJ ECC802S, which is an excellent tube in every aspect.
   
  I do definitely agree when it comes to the driver tube though. While the 5998 is an undisputed favourite, I could absolutely live with any of the 6080 or 6AS7 variants.


----------



## amcananey

Interesting. The Crack was actually the amp that led me to sell my WA22. Even with $500-600 of upgrade tubes in my WA22, I thought the Crack + Speedball demolished it. In comparison to the Crack, I thought the WA22 sounded thick, slow and lacking in detail. The speed, details and transparency of the Crack seemed like a revelation to me...


----------



## EraserXIV

Quote: 





beefy said:


> I'm not a fan of the 12BH7. I have tried three different examples, and they were all a bit slow and bloated compared with the 12AU7 variants I've had. My favourite is still the new production JJ ECC802S, which is an excellent tube in every aspect.
> 
> I do definitely agree when it comes to the driver tube though. While the 5998 is an undisputed favourite, I could absolutely live with any of the 6080 or 6AS7 variants.


 
   
  How would you describe the signature of the JJ ECC802S? Does it lean more towards the warm Mullard signature or the detailed Tele signature?
   
Also curious about the Psvane 12au7 variant if anyone has heard it.


----------



## younglee200

Since everyone seems to have a difference in terms of preference in terms of tube rolling, what are the reliable sites that I can purchase from?


----------



## Beefy

Quote: 





eraserxiv said:


> How would you describe the signature of the JJ ECC802S? Does it lean more towards the warm Mullard signature or the detailed Tele signature?


 
   
  Blerg, sorry, but I've got better things to do than that sort of linguistic masturbation about sound signatures. It sounds plain good.


----------



## DefQon

Lol. If it sounds good thats aplthat matterd


----------



## amcananey

I've purchased tubes from a number of different vendors. They were all generally fine, but I would say that I've had the best customer service from Brent Jessee Recording & Supply, a/k/a Audiotubes: http://www.audiotubes.com/ Best regards, Adam


----------



## amcananey

FWIW, I would agree about not going overboard in trying to describe what various tubes sound like. To be honest with you, in my experience the changes are generally much, much smaller than some would have you believe. And think about what it takes to compare tubes: 1. Turn on amp with Tube 1 in it. 2a. Let amp and tubes warm up until you hear undistorted music. 2b. [Optional: Arguably, you should wait until the tubes are REALLY warmed up, say 10-15 minutes or so.] 3. Listen to music until you get a good feel for it. 4. Turn off amp. 5. Let tubes cool down. 6. Remove Tube 1. 7. Insert Tube 2. 8. Turn on amp with Tube 2 in it. 9a. Let amp and tubes warm up until you hear undistorted music. 9b. [Optional: Wait 10-15 minutes until the tubes are REALLY warmed up.] 10. Listen to music until you get a good feel for it. This is just for a single A/B comparison. I don't know about you, but I usually need to do something like A/B/A/B/A in order to really hear any differences. How long between hearing music through warmed up Tube 1 and warmed up Tube 2? 10 minutes? 15 minutes? If I'm being brutally honest, I can't reliably remember what Tube 1 sounded like by the time I get around to listening to Tube 2. The one thing I do notice, and that I feel is fairly objective, is how noisy a tube is, and whether it is highly microphonic. Best regards, Adam


----------



## amcananey

Can anybody explain to me why it is that my posts and IMs here on Head-Fi now lose all formating? My paragraph breaks just get tossed out the window, and everything becomes an uninterrupted and unformatted blob of text that is very difficult to read... Grrrrrrrrrrrrrrr, Adam


----------



## Armaegis

Do you have the upper toolbar in your textbox? There's a "Source" button there that can mess up all the formatting.


----------



## amcananey

Nope. No toolbar whatsoever. I've posted a note in the bug report forum.


----------



## Jmstrmbn

Amcananey, what is your source with the HD 800 rig?  I've got 600s now and a Crack but no speedball yet.  I feel if I ever feel the need to upgrade it will be the 800s.  The reason I ask is my next upgrade will be a new Dac to replace the Nuforce HDP.


----------



## Armaegis

edit. sent pm instead


----------



## GaryPham

Alright just placed my order.  Excited!! This is actully going to my very first amp building project, but I'm going to be receiving some help from my electrical engineer friend.  For all you guys who have experience buidling this amp, is there any common pitfalls we should be looking out for?  I really want to make this amp as clean and neat as possible so any useful tips would be greatly appreciated = D.  Thanks!! and hopefully I'll be part of the club and discussing tube rolling with you guys in a few weeks.


----------



## ben_r_

Quote: 





garypham said:


> Alright just placed my order.  Excited!! This is actully going to my very first amp building project, but I'm going to be receiving some help from my electrical engineer friend.  For all you guys who have experience buidling this amp, is there any common pitfalls we should be looking out for?  I really want to make this amp as clean and neat as possible so any useful tips would be greatly appreciated = D.  Thanks!! and hopefully I'll be part of the club and discussing tube rolling with you guys in a few weeks.


 

 Just read the entire instruction manual and take your time and do everything slowly and surely. Youll be fine.


----------



## Beefy

Quote: 





garypham said:


> For all you guys who have experience buidling this amp, is there any common pitfalls we should be looking out for?


 
   
  This amp is pretty easy, but general advice...... take your time, plan everything well in advance, and get it right the first time. And irrespective of how most tooling discussion focuses on which soldering iron you should buy, I get the most 'joy' out of good quality pliers and wire strippers.


----------



## Utopia

Quote: 





garypham said:


> Alright just placed my order.  Excited!! This is actully going to my very first amp building project, but I'm going to be receiving some help from my electrical engineer friend.  For all you guys who have experience buidling this amp, is there any common pitfalls we should be looking out for?  I really want to make this amp as clean and neat as possible so any useful tips would be greatly appreciated = D.  Thanks!! and hopefully I'll be part of the club and discussing tube rolling with you guys in a few weeks.


 
   
  This article has some interesting notes regarding the build that seem useful (still waiting for my kit, so I have no experience from building it myself yet):
   
http://www.innerfidelity.com/content/marvelously-addictive-bottlehead-crack


----------



## GaryPham

How long does it usually take to receive the kit after ordering?


----------



## Doc B.

It just depends upon order volume. Right now we are working through a large number of orders from the recent sale. We have had to order an additional run of power transformers to cover all of the orders and it will probably be a couple or three weeks before we see them.


----------



## walls

Bottlehead shows Crack orders up till July 7th have shipped, I ordered mine on the 8th. DAMMIT. LOL!!


----------



## dsound

Congrats on the purchase.
   
  Think of the wait as part of the shared-Bottlehead experience.  
	

	
	
		
		

		
			




  Quote: 





walls said:


> Bottlehead shows Crack orders up till July 7th have shipped, I ordered mine on the 8th. DAMMIT. LOL!!


----------



## amcananey

jmstrmbn said:


> Amcananey, what is your source with the HD 800 rig?  I've got 600s now and a Crack but no speedball yet.  I feel if I ever feel the need to upgrade it will be the 800s.  The reason I ask is my next upgrade will be a new Dac to replace the Nuforce HDP.




I'm using an Audio-Gd Ref. 5-32. But I'll be blunt --- I'm deeply skeptical when it comes to differences between DACs. There are about 100 other things I would spend money on before "upgrading" my DAC. I have a number of different DACs, and I doubt I could tell them apart in a blind test...

(That said, if you catch me in the right (i.e., mostly delusional) mindset, you might be able to convince me that DACs based on the PCM1704UK chips sound better than DACs based on newer chips. Look up those chips if you're not familiar with them. Different technology from almost all other chips used today. I have a couple of DACs that use them, and they seem to be my favorites...)


----------



## amcananey

Four tips:

1. There is a note in the manual about less noise if you wire a wire to terminal 14 instead of whatever the other option is. Terminal 14 gets very, Very, VERY crowded. You really need to work to get everything to fit. It's possible, but you will have to get creative and be patient.

2. NOTE THE DIFFERENCE BETWEEN "ATTACH" and "SOLDER". True, the manual mentions this, and there are only a few places where it is relevant, but never assume you're supposed to solder something unless the manual explicitly says to solder it. Just attach it, then wait until later in the manual when you are instructed to solder it.

3. At the end, you have to do voltage checks with the tubes in and the power on. To do this, put a couple of books or something under each end of the wood case to raise it a few inches, then flip the metal chassis over and lay it on top of the wooden case. Otherwise you won't have enough clearance for the tubes.

4. When the manual references the "ground bus", just use the ground terminal that is also referenced for the resistance checks. 

Best regards,
Adam


----------



## RedBull

amcananey said:


> I'm using an Audio-Gd Ref. 5-32. But I'll be blunt --- I'm deeply skeptical when it comes to differences between DACs. There are about 100 other things I would spend money on before "upgrading" my DAC. I have a number of different DACs, and I doubt I could tell them apart in a blind test...
> 
> (That said, if you catch me in the right (i.e., mostly delusional) mindset, you might be able to convince me that DACs based on the PCM1704UK chips sound better than DACs based on newer chips. Look up those chips if you're not familiar with them. Different technology from almost all other chips used today. I have a couple of DACs that use them, and they seem to be my favorites...)




Lucky you  ignorance is bliss.
Believe me, some people can't even tell amps apart, best of all, some people can't seem to tell headphones apart.
Imagine how much money have they saved.


----------



## uzi

Quote: 





amcananey said:


> I'm using an Audio-Gd Ref. 5-32. But I'll be blunt --- I'm deeply skeptical when it comes to differences between DACs. There are about 100 other things I would spend money on before "upgrading" my DAC. I have a number of different DACs, and I doubt I could tell them apart in a blind test...


 
  I was a skeptic too, but I'll wager that you'd be able to easily hear a difference between the HRT Musicstreamer II and the HRT Musicstreamer II+ with my HD650 (and either my Bottlehead Crack+Speedball or my Burson Soloist).  The MSII+ is clearly better... after I bought it used, I gave my wife a quick listen to prove I wasn't nuts.  It just took the opening parts of Elton John's "Take Me To The Pilot" to do so.
   
  (Meanwhile, the MSII and the ODAC were so similar sounding that I was thinking it was snake oil until I heard the MSII+.)


----------



## younglee200

I've been trying to consolidate all my little equipments into one, got myself the crack+speedball (currently on order), the audio gd 3.2 as the DAC and the hd650+cardas.
   
  The other headphones that even come close to the price-range of the HD650 is the Audio Technica a900x and HFI 780, both closed headphones.  
   
  Now, with that said, I hate the HD650s.  Sound feels extremely veiled, very very dark, and muddy.
   
  Right now, as I'm waiting for the crack, I'm driving them out of an M^3 amp with Sigma11 PSU.  I realize that higher cost often doesn't equate to better quality, and I know it's been said over and over that SS amp's generally don't do good justice with the 650s, but I've always thought that the M^3 was supposed to sound closer to a tube-amp.
   
  The 650 sounds dark, muddy, murky, definitely not relaxing by any means... and I definitely prefer the 780 or A900x to this.  Sometimes even the Grado 60 sounds better.
   
  With that said, could I really be hoping for that big of an improvement with the Crack?  I still have really high hopes for the 650s, but it's not looking too bright right now.  I've no plan to upgrade to an 800 for a long while.  Any other headphones that I could potentially look into if the 650s just don't look right for me?


----------



## amcananey

A couple of points:

- I also have an M^3 with Sigma 11. Yes, the HD650s will sound noticeably better out of the Crack. Don't get me wrong, the M^3 is one of my favorite amps (I liked it better than my top-of-the-line Beta 22), but the HD650s do sound better with the Crack.

- I also find the HD650s to sound veiled, which is why I keep harping that the HD600s are better, despite being cheaper. The HD650s are basically like HD600s, minus treble extension, sparkle and some resolution. So you could try the HD600s.

- I am surprised to hear you say you prefer the Ultrasone HFi 780s. While they are decent, and although I don't like the HD650s, I do think the HD650s are better. With but one exception (which I will get to in a minute) I have found the closed back Ultrasones to be kind of wonky and give me headaches. If you can find a used pair, an excellent option for you would be the Ultrasone Pro 2900s, which are open-backed and solve a lot of the problems I've found with other Ultrasone models. Plus, they will retain that Ultrasone house sound for you (some people dislike it, but that obviously doesn't seem to be an issue for you). The Pro 2900s are a step up from the HFI 780s in every way.

- The only closed-back Ultrasone I've liked are actually some of my favorite headphones, and they are very close to being the closed-back HD800s (sounds insane, but its true). I'm talking about the Ultrasone Signature Pros. They do NOT have the Ultrasone house sound. In fact, they stick out like a sore thumb in the Ultrasone lineup, since they seem to come out of nowhere and are head and shoulders above the rest of the Ultrasone models on technicalities. But they're not cheap, so try to find a used pair.

- if you can find a pair (new or used), I highly recommend the Kenwood KH-K1000s. Very balanced, neutral headphone, good bass and resolution, exceptionally comfortable, easy to drive, not that expensive. I prefer the HD600s properly amped, but I can see how others might prefer the K1000s, especially if they need or want closed-back headphones. 

- Lastly, I highly recommend the HiFiMAN HE-500s. In fact, you might even want to put them at the top of your list. World-class performance. I really have no complaints (except that my HE-6s are even better ). 

I think that gives you a number of good options at different price points. But you might want to build the Crack+Speedball before making a final decision. Like I've said before, the Crack cures a lot of what ails the HD650s. Still, I would prefer any of my suggestions above over the HD650s.

Best regards,
Adam


----------



## younglee200

I hear a lot of good things about the HE-500s, but I want to avoid them as much as possible because the weight is too heavy for me. I owned the HE-400s before this and the biggest reason for selling those into the HD650s was due to the heavy weight.
   
  A big must for me (probably the most important factor, probably just as important as sound itself) in headphones is comfort.
   
  If the 650's aren't for me, I'm thinking about just trying to move into the Audio-Technica, Denon, or the Grado line.  I feel like that the downside (if you could even call it that) of the Crack is that because it's an OTL tube amplifier, it does not pair well with lot of headphones in the market, due to the low resistance.  I don't even know of headphones that hold high enough impedance other than few of the Senn headphones & the Beyer headphones.
   
  Regardless, despite all this negativity from me, I still have very very high expectations from the Crack - almost everyone claiming and swearing by them can't be wrong... right?  Regardless of what might happen, I will ideally still keep the amplifier as my one tube amp with the M^3.


----------



## amcananey

The KH-K1000s and Ultrasone Signature Pros are both extremely comfortable and lightweight. I'd give the nod to the K1000s in terms of comfort, but they are a bit bulkier than the Sig Pros.


----------



## amcananey

If you go for Denons, try to find a pair of D2000s. I love the D5000s and D7000s, but the D7000s are expensive, and the D5000s are definitely colored (albeit in a way I love). The D2000s are the best value, and in some ways the best performers. Too bad they were discontinued and are so expensive now...

For the most part, I dislike the shrill Grados (SR325s, RS-1s, etc.), and I find the non-shrill Grados (HF-2, PS500s, etc.) to be wildly overpriced relative to their performance. The best option in the Grado lineup is probably the SR225is or the Alessandro MS-2s.


----------



## Beefy

Quote: 





younglee200 said:


> Regardless of what might happen, I will ideally still keep the amplifier as my one tube amp with the M^3.


 
   
  Just an additional perspective...... I have some ATH-AD900 from an M3, HD650 from a Crack, and some Stax. Many headphones and amps have come and gone, but these have been with me for a while.
   
  They are all very different combinations, all kept for very deliberate purposes. I don't switch around headphones with amps, they stay where they are because that is how they sound best.


----------



## ULUL

Quick question - probably revealing my ignorance more than I'd like....
	

	
	
		
		

		
			




   
  Is there a way to use a BALANCED DAC output from XLR output to the RCA input of the Crack without impacting the signal?  I have a very detailed and neutral DAC that puts its best output via XLR balanced jacks. This is of course assuming that CRACK pairs better with a highly detailed neutral DAC than one that is more warm/liquid as the Crack probably provides the liquid touch.  (Please correct me if I am wrong.)
   
  Thanks,
  UL


----------



## brunk

Quote: 





ulul said:


> Quick question - probably revealing my ignorance more than I'd like....
> 
> 
> 
> ...


 
  You can use XLR-to-RCA cables, but i would expect very little play with volume control because the signal will be 2x strength.


----------



## Beefy

Quote: 





brunk said:


> You can use XLR-to-RCA cables, but i would expect very little play with volume control because the signal will be 2x strength.


 
   
  It probably wouldn't be stronger, because XLR-RCA cables usually only take half the signal around ground.


----------



## uzi

Quote: 





younglee200 said:


> Now, with that said, I hate the HD650s.  Sound feels extremely veiled, very very dark, and muddy.
> 
> The 650 sounds dark, muddy, murky, definitely not relaxing by any means... and I definitely prefer the 780 or A900x to this.  Sometimes even the Grado 60 sounds better.
> 
> With that said, could I really be hoping for that big of an improvement with the Crack?  I still have really high hopes for the 650s, but it's not looking too bright right now.  I've no plan to upgrade to an 800 for a long while.  Any other headphones that I could potentially look into if the 650s just don't look right for me?


 
  I love the HD650.  It is warm and relaxing to me.  I have a feeling that if you don't like 'em with the M^3 that you won't like 'em with the Crack.
   
  Do you perhaps like brighter headphones?  Perhaps consider the DT880/600?  Related: if it interests you, I have a pair I'll sell you.


----------



## GaryPham

For you guys who are saying the 650 sounds veiled and muddy, do you have the white driver version? I have he white driver version and don't find them veiled or muddy at all. Maybe it's the ess9018 dac, but on my audio gd nfb 11.32 they sound just as revealing and detailed as my 600ohm 880, except with slightly less bright treble and slightly more bass


----------



## amcananey

I've had three different pairs of HD650s with various drivers. All sounded the same to me. I don't want to overhype this and claim that the HD650s are complete crap and sound like sludge. That's obviously not true. But I do think they are a solid step behind the HD600s. Here is the thing: if you listen to music that is mostly focused in the mids and bass, the HD600s and HD650s sound pretty similar. But anything with significant treble in it and the HD650s take a nose dive in relative clarity.


----------



## RedBull

But HD650 wins on smoothness, soundstage depth and instrument separation over HD600, which soundstage appears to be flatter.


----------



## skeptic

The problem with the hd600 in my opinion (and setting aside the horrendous paint job) - is the unfortunate peak around 2.5khz.  This means they have the same problem dt880's have.  Many natural instruments, including violins, play fundamental frequencies >3khz, so that peak will actually impact the loudness of certain treble notes, rather than simply impacting overtones (i.e. timbre), like peaks higher on the curve do.
   
  Compare:


----------



## DefQon

The 600 is more neutral than the 650.


----------



## skeptic

That's certainly the common lore on head-fi, but I think "neutral" needs defining.  The hd600's don't have the mid-bass hump, but a gradual roll-off as opposed to a 5db peak at ~3khz makes the hd650's more neutral (although less detailed sounding) in the upper mids, imo.


----------



## Hibuckhobby

I find that I prefer the spatiality (made up that word) of the HD650 especially on acoustic music.
  The difference between the two tonally, I do not find to be huge....although the 600 does sound a
  bit flatter above 3k.   At the end of the day, it's about what your ears/tastes find pleasing.  You
  listen with your ears, not an RTA microphone.
  Hibuck....


----------



## Beefy

My whole point in keeping the HD650 around is because they are more relaxed than my other phones. I have plenty of music that is just far too energetic with the speed/precision of the Stax or AD900; it is terrible for just chilling out with the music. That being said, the Crack does give the HD650 more life than the other amps I have tried with them.
   
  And FWIW, I can't see how anybody could possibly call the HD650 neutral - way too much low end.


----------



## amcananey

To get the conversation back on track...whatever the differences between the HD650s and HD600s (I've owned enough copies of both to be confident that I have picked the right ones for me), the Crack is the best amp I've found for either, and whatever flaws I personally perceived in the HD650s, I found the Crack went a long way toward remedying them.
   
  So....Bottlehead for the win! 
	

	
	
		
		

		
			




   
  Best regards,
  Adam
   
  P.S. I agree about the paint job on the HD600s. _*WHO ON EARTH*_ looked at that and said, "Oh, this would be a great design for our [then] flagship headphones!" Lord knows I love my HD600s, but that paint job is just hideous. The HD580s look better, and the HD650s look better. The HD600s are just butt-effing ugly. Then again, my favorite all-time headphones are the HD800s, which are probably even uglier than the HD600s. But at least there you can argue form follows function, whereas the HD580s and HD650s make it abundantly clear there is no reason for the HD600s to look like they were made with some leftover wallpaper your grandmother had up in her attic...


----------



## ULUL

Just one vote here from someone who also prefers the HD650 over the HD600 for its warmth 'fatness' of tone. But I also like other more articulate, balanced headphones - just not the HD600 as much for some reason.
   
  UL


----------



## FlySweep

I've got a pair of Sylvania 6F8G/VT-99.. my understanding is that this tube is a drop in/replacement for the 6SN7.. so I should just be able to use my 6SN7 adapter for the Crack.  Well, this doesn't seem to be the case since after installing it in the Crack with the 6SN7 adapter, I hear no music and get a slight hum in one channel.  As I noted, I have two of these tubes.. both were bought from the same (reputable) tube supplier (who has tested them thoroughly).. so I'm quite confident this isn't a "faulty tube" issue.
   
  Can anyone confirm the 6F8G/VT-99 works in the Speedballed Crack?


----------



## GrindingThud

6F8G requires a different adapter, not the same pinout as 6SN7 and also has a wire going to the pin on top.

http://www.ebay.com/itm/1pc-gold-plated-6F8G-6C8G-TO-6SN7-tube-adapter-Free-shipping-/200905127802?pt=Vintage_Electronics_R2&hash=item2ec6e0f77a



flysweep said:


> I've got a pair of Sylvania 6F8G/VT-99.. my understanding is that this tube is a drop in/replacement for the 6SN7.. so I should just be able to use my 6SN7 adapter for the Crack.  Well, this doesn't seem to be the case since after installing it in the Crack with the 6SN7 adapter, I hear no music and get a slight hum in one channel.  As I noted, I have two of these tubes.. both were bought from the same (reputable) tube supplier (who has tested them thoroughly).. so I'm quite confident this isn't a "faulty tube" issue.
> 
> 
> Can anyone confirm the 6F8G/VT-99 works in the Speedballed Crack?


----------



## AION

Quote: 





flysweep said:


> I've got a pair of Sylvania 6F8G/VT-99.. my understanding is that this tube is a drop in/replacement for the 6SN7.. so I should just be able to use my 6SN7 adapter for the Crack.  Well, this doesn't seem to be the case since after installing it in the Crack with the 6SN7 adapter, I hear no music and get a slight hum in one channel.  As I noted, I have two of these tubes.. both were bought from the same (reputable) tube supplier (who has tested them thoroughly).. so I'm quite confident this isn't a "faulty tube" issue.
> 
> Can anyone confirm the 6F8G/VT-99 works in the Speedballed Crack?


 
   
   
  6F8G definitely works with Crack, but looks like you can't just use 6SN7 to 12AU7 adapter. You need another adapter for 6F8G exclusively.
  See these links:
  http://www.bottlehead.com/smf/index.php/topic,4196.msg38814.html#msg38814
  http://www.head-fi.org/t/548267/new-product-universal-teflon-tube-adapter
   
  Hope this helps.
  Kris


----------



## AION

oooops. Looks like GrindingThud responded as I was typing


----------



## FlySweep

grindingthud said:


> 6F8G requires a different adapter, not the same pinout as 6SN7 and also has a wire going to the pin on top.
> 
> http://www.ebay.com/itm/1pc-gold-plated-6F8G-6C8G-TO-6SN7-tube-adapter-Free-shipping-/200905127802?pt=Vintage_Electronics_R2&hash=item2ec6e0f77a


 



aion said:


> 6F8G definitely works with Crack, but looks like you can't just use 6SN7 to 12AU7 adapter. You need another adapter for 6F8G exclusively.
> See these links:
> http://www.bottlehead.com/smf/index.php/topic,4196.msg38814.html#msg38814
> http://www.head-fi.org/t/548267/new-product-universal-teflon-tube-adapter
> ...


 
   
  Thanks fellas.. can the 6F8G adapter be "daisy chained" with the 6SN7 adapter?  Yep, it's gonna look jankety as hell.. but I just want to know my options.. or would it better to go with this?


----------



## GrindingThud

Yes and yes



flysweep said:


> Thanks fellas.. can the 6F8G adapter be "daisy chained" with the 6SN7 adapter?  Yep, it's gonna look jankety as hell.. but I just want to know my options.. or would it better to go with this?


----------



## Cryok95

Quote: 





amcananey said:


> To get the conversation back on track...whatever the differences between the HD650s and HD600s (I've owned enough copies of both to be confident that I have picked the right ones for me), the Crack is the best amp I've found for either, and whatever flaws I personally perceived in the HD650s, I found the Crack went a long way toward remedying them.
> 
> So....Bottlehead for the win!
> 
> ...


 

 I couldn't agree more. The colour scheme for the hd600s are HORRIBLE. Other than that, i do prefer the hd600s over the hd650s. Of course the hd800 triumphs both, but at what price?
 Though, for the hd600 owners out there, i'll recommend for you to change the stock cable to an aftermarket cable to get rid of the senhisser veil.

 My dream headphones are still the hd800s. Fell in love with it while testing my friend's unit with my crack.


----------



## skeptic

Quote: 





flysweep said:


> Thanks fellas.. can the 6F8G adapter be "daisy chained" with the 6SN7 adapter?  Yep, it's gonna look jankety as hell.. but I just want to know my options.. or would it better to go with this?


 
   
  Daisy chained adapters seems like a pretty dicey proposition to me (if for no other reason than the terrible QC of the ebay sellers).  From your recent impressions of your crack + vt231, it sounds like you got pretty lucky with your first adapter.  I've purchased two now, and both add audible noise to the equation that makes going back to my 12au7's and 12bh7's feel like a breath of fresh air.  Maybe you'll roll the dice and win again, but I'd encourage anyone contemplating adapters to bear in mind that it is a gamble and a very frustrating waste of time and money if your experience ends up matching my own....


----------



## amcananey

Couldn't agree more. I have a 6SN7 --> 12AU7 adapter and it adds incredibly annoying noise. Just stick to the 12AU7s, 12BH7s and, if you want, E80CCs.


----------



## J-Pak

Quote: 





doc b. said:


> It just depends upon order volume. Right now we are working through a large number of orders from the recent sale. We have had to order an additional run of power transformers to cover all of the orders and it will probably be a couple or three weeks before we see them.


 


 This is great news, I ordered a kit for my work setup. It will replace a M^3. I built my friend one with Axon caps and Speedball last year. I was testing it out with my HD580 and it was so good I had to sneak in a listen with the HD800. It's not up to the Balancing Act, but still a fine amplifier.


----------



## Doc B.

I just got news that we will be able to ship a few more kits, primarily ones that were ordered right before the sale and maybe some of the very first sale amps ordered. Then there will be a gap in shipping until the next production run of power transformers arrives, which have an ETA of August 20th. We are working to have everything else in place so that when the transformers get here the kits should ship right away.


----------



## EraserXIV

I have this recurrent issue where I hear white noise through the Crack and I need to jiggle around the 12AU7 socket a bit for it to go away. The white noise does not fluctuate with the volume knob. Anyone know what might be causing this? I know it's not the tube since it happens irregardless of the tube I use and those tubes are quiet in other amps. I'm thinking it's a cold solder joint but wanted to hear any other thoughts before I try to resolder everything on that socket.


----------



## amcananey

You're better off posting in the Bottlehead forum. You will get diagnostic advice very quickly over there.


----------



## fcpchop88

Quote: 





doc b. said:


> I just got news that we will be able to ship a few more kits, primarily ones that were ordered right before the sale and maybe some of the very first sale amps ordered. Then there will be a gap in shipping until the next production run of power transformers arrives, which have an ETA of August 20th. We are working to have everything else in place so that when the transformers get here the kits should ship right away.


 
   
  Thanks for the update doc! Looks like I'll be waiting another few weeks or so, understandable considerining the unexpected volume of orders. keep us posted


----------



## amcananey

amcananey said:


> You're better off posting in the Bottlehead forum. You will get diagnostic advice very quickly over there.



 
 Ha! I see you posted on the Bottlehead forum, and Doc responded 12 minutes later! That's customer service for you...


----------



## EraserXIV

Quote: 





amcananey said:


> Ha! I see you posted on the Bottlehead forum, and Doc responded 12 minutes later! That's customer service for you...


 
   
  Haha yeah thanks for the tip! I got impatient and just resoldered all the joints at the 12AU7 socket before I even checked for a response. It's back to being dead silent. Problem solved!


----------



## captouch

I had a cold solder joint that also lead to an intermittent hum. Such a relief when you find the root cause and it goes silent, eh?


----------



## Doc B.

Quote: 





doc b. said:


> I just got news that we will be able to ship a few more kits, primarily ones that were ordered right before the sale and maybe some of the very first sale amps ordered. Then there will be a gap in shipping until the next production run of power transformers arrives, which have an ETA of August 20th. We are working to have everything else in place so that when the transformers get here the kits should ship right away.


 
  Trying to be a man of my word - the last few not-yet-shipped Crack orders that came in previous to the sale have shipped, and the first group of the sale kits have shipped. A few 120V sale kits shipped and a few 240V sale kits shipped. The next batch to ship will probably be on Monday, and that will be most or all of the outstanding 240V kits, as we have plenty 240V power transformers in stock. Eileen will be talking to our winder to see if we can sneak a few 120V transformers in ahead of the bulk of the order and get those shipping out again as soon as we can. Thanks to all for your patience. We got about 5 times the quantity of orders we expected, and we are pedaling really hard to get them all delivered.


----------



## brunk

Quote: 





doc b. said:


> Trying to be a man of my word - the last few not-yet-shipped Crack orders that came in previous to the sale have shipped, and the first group of the sale kits have shipped. A few 120V sale kits shipped and a few 240V sale kits shipped. The next batch to ship will probably be on Monday, and that will be most or all of the outstanding 240V kits, as we have plenty 240V power transformers in stock. Eileen will be talking to our winder to see if we can sneak a few 120V transformers in ahead of the bulk of the order and get those shipping out again as soon as we can. Thanks to all for your patience. We got about 5 times the quantity of orders we expected, and we are pedaling really hard to get them all delivered.


 
  Thanks for the update Doc, great customer service! Can't wait to get hooked on Crack!


----------



## caracara08

got my shipment confirmation for my sale order of the crack!


----------



## walls

Got mine too!


----------



## mellowbob

Ditto. Just saw a UPS notification. Time to shop for a soldering iron!


----------



## GaryPham

Excited to be receiving mine too.  Looks like I'll have to wait for next shipment batch though.  Not sure if this is an appropriate thread to be asking this though, but I was looking on getting an affordable upgrade driver tube and was wondering if anyone here can give me impressions of the re-issued Tung-Sol 6189.  I see that I can get it for around 15 bucks shipped on ebay and saw some positive feedback on the bottlehead forums, but was wondering if I should even bother or if it's not much of an improvement from the stock tube.  I'm not quite ready yet to be dropping big bucks for upgraded tubes and was just hoping to get the best bang for my buck (going to be pairing with NFB 11.32 and HD650).


----------



## Doc B.

In general the reissue tubes have little to do with the originals other than that they work fine as replacements. Typically they are "select" samples of current production Russian tubes, sometimes with gold plated pins. Not saying it's a bad tube, the price is quite reasonable. Just saying, don't expect it to sound like a Tung Sol.


----------



## GaryPham

Doc what would you say is a good replacement tube over the original for someone who isn't ready to spend too much? Anything worthwhile under 30 dollars? (preferably under 20)?


----------



## Doc B.

That depends in part upon what the original tube is. We tend to buy old stock tubes and thus our customers receive whatever brands and types we may have acquired recently. Thus the assumption that it must be improved upon is not a given. I'm not really the guy to ask about what flavor of the week to buy as I use tubes that I gathered many years ago, that now go for stupid money. One that I like that is not stupid expensive is the Mullard CV4003. There is a thread about 500 posts long on the Bottlehead Forum that is all about what tubes people use in their Crack amps. Reading it might be an interesting way to spend an hour or two.


----------



## amcananey

I'd like to underline what Doc just said. Don't assume that you need to replace the stock tube, or even that you will see an appreciable difference when using a different tube. Frankly, I haven't heard any tubes (other than 6SN7 tubes via adapter) that sounded bad (or, to be precise, anything less than stellar) with the Crack, and the differences among the tubes I have tried have honestly been minimal, at best. I wouldn't really bother swapping tubes unless you have a compelling reason to do so, and I can't imagine what that would be. Best regards, Adam


----------



## Doc B.

240V Crack kits from the sale are all packing today, which means a few to US addresses go out today UPS and the rest via USPS are shipping out tomorrow. Eileen called our winder and talked them into bumping our order for 120V power transformers up a week, so the shipping of the outstanding 120V sale kits will probably begin in about a week and a half to two weeks.


----------



## Dark Helmet

Tubes can be very synergistic in terms of how the driver  tube sounds with the power tube.  I have tried a few combinations and I like the Clear top RCA 12AU7 with my RCA 6AS7G.  I keep going back to this combination, which works well for me.  Remember not all tubes of the exact same type/brand will sound the same either.  Both of the tubes I use can be had for a price on par with the new russian tubes that are now available.


----------



## Sayari

Crack w/ Speedball mod rules ! Doc, many thanks for your timeless design...


----------



## Doc B.

Thanks for the kind words!


----------



## mellowbob

I received the package today. Really excited to see if I was one of the first 6 to place an order during the free speedball sale. Opened the box and no tubes were included in the package. The packing list had the tubes checked off but none were found. 



Looks like I'll be calling Bottlehead in the morning.


----------



## amcananey

Eileen will take care of you. You'll have them before you finish your build...


----------



## hedphonz

Quote: 





mellowbob said:


> I received the package today. Really excited to see if I was one of the first 6 to place an order during the free speedball sale. Opened the box and no tubes were included in the package. The packing list had the tubes checked off but none were found.
> 
> 
> 
> Looks like I'll be calling Bottlehead in the morning.


 
  I too will be waiting to see if i am one of the lucky ones - i ordered within 10mins of receiving the email - however I wont be too upset as the free speedball is a huge bonus already.
  Also i can almost guarantee that I wont be able to resist the temptation of investing in 1 or 2 " premium " tubes so the tubes that come with it will probably be stored for back up anyway.
   
  Just bought myself a hakko soldering station - cant wait to abuse it on the crack haha


----------



## brunk

Quote: 





hedphonz said:


> Spoiler: Warning%3A%20Spoiler!
> 
> 
> 
> ...


 
  Haha nice! I bought the cheap Stahl soldering station for $12 on parts-express. It does go to 450 though, which will work the 4% silver solder i got there under their house brand. 1/2lb. for $44, pretty good considering the WBT 4% silver solder is $44 for 1/8lb. 
	

	
	
		
		

		
			




   
  Also got a bunch of extra tips, pliers, solder tools, wicks, DMM etc. The works for about $200 including a nice Plano toolbox for it all to go in


----------



## palmfish

I finally got to hear the Crack with my HD800's at the last Seattle meet and I really liked it. I bought a kit from a fellow Seattle head-fier who never got around to building his. His kit was BNIB. I started building it this past weekend and got all the pre-soldering work completed tonight.
   
  Ive been taking pictures along the way and here's where I'm at so far...
   

   

   

   

   

   
  More to follow in the coming days!


----------



## DefQon

Didn't you stripe off the paper stuck to the underside of the metal plate?


----------



## palmfish

Nah, it doesnt bother me.


----------



## Nowhere

are these sold pre built with the speedball upgrade anymore? if so how much does it normally cost?


----------



## telecaster

Love the hammertone on the plate, will you stain the wooden casework?


----------



## DefQon

Quote: 





nowhere said:


> are these sold pre built with the speedball upgrade anymore? if so how much does it normally cost?


 
  Nope. Both are sold separately unless Doc runs one of those special limited orders where if you order a Crack before a date you get free Speedball upgrades, one recently just went by. All details and pricing is at bottlehead.com. Contact Eileen (Queen) or Doc for help on ordering or make an inquiry on the forums.


----------



## amcananey

Doc just announced in the Bottlehead forum that they will start working with a Bottlehead authorized builder, for people who don't want to build their own kits. The guy isn't ready to accept work yet, however. So no word on pricing or on when this service will be available.


----------



## palmfish

telecaster said:


> Love the hammertone on the plate, will you stain the wooden casework?




Thanks! i browsed the Bottlehead forums one night and looked at a bunch of pictures of other builds. It gave me some great ideas including using hammertone paint.

The plate is Dark Bronze and I plan to stain the base in English Chestnut.


----------



## GaryPham

So I'm pretty excited bout the BH crack (should work beautifully for my HD650s) but was wondering if anyone had first hand experience on how it sounds with Denons.  I have a pair of D2000s which I absolutely love but am not quite sure how it will match up with the BH Crack.  I know on theory it will be a bad match due to the low impedance on the Denons, but I have heard lots of people say that Grados work surprisingly well with the BH crack.  Can someone who's had first hand experience give me their impression? (I ordered a BH crack with speedball if that makes any difference).


----------



## palmfish

I used to have D7000's and still have D2000's and I suspect they will sound great with the Crack. In my experience, the Denon's are more or less unaffected by high output impedance amps because their impedance is stable across the entire frequency range and they have a lot of mechanical damping. In other words, they do not rely on electrical damping to control the driver.


----------



## telecaster

Quote: 





palmfish said:


> Thanks! i browsed the Bottlehead forums one night and looked at a bunch of pictures of other builds. It gave me some great ideas including using hammertone paint.
> 
> The plate is Dark Bronze and I plan to stain the base in English Chestnut.


 
  Sweet choice of finishes!!
  If I could lay my hand on a kit, I'll be inspired to do a dark gray hammertone and a black stain


----------



## brunk

Quote: 





garypham said:


> So I'm pretty excited bout the BH crack (should work beautifully for my HD650s) but was wondering if anyone had first hand experience on how it sounds with Denons.  I have a pair of D2000s which I absolutely love but am not quite sure how it will match up with the BH Crack.  I know on theory it will be a bad match due to the low impedance on the Denons, but I have heard lots of people say that Grados work surprisingly well with the BH crack.  Can someone who's had first hand experience give me their impression? (I ordered a BH crack with speedball if that makes any difference).


 
  My only concern would be the noise of a stock Crack with Denons. Hopefully someone can share those experiences here.


----------



## Greed

Just wanted to get an update from those that didn't receive tubes in their packages. My package was delivered yesterday, and it seems I was also short the tubes and they were checked off on the packing list. Any news? I still need to do a proper inventory to see if I'm missing anything else.


----------



## brunk

Quote: 





greed said:


> Just wanted to get an update from those that didn't receive tubes in their packages. My package was delivered yesterday, and it seems I was also short the tubes and they were checked off on the packing list. Any news? *I still need to do a proper inventory to see if I'm missing anything else.*


 
  That's something I'll definitely be doing now once i receive my kit.


----------



## mellowbob

greed said:


> Just wanted to get an update from those that didn't receive tubes in their packages. My package was delivered yesterday, and it seems I was also short the tubes and they were checked off on the packing list. Any news? I still need to do a proper inventory to see if I'm missing anything else.




I was also missing the #4 small nuts when I was putting it together last night.
I called this morning to get the missing tubes and nuts. The guy I talked to just needed my name. Don't forget to mention that you might be the first 6 orders to get the clear top rca tube.


----------



## Greed

Quote: 





mellowbob said:


> I was also missing the #4 small nuts when I was putting it together last night.
> I called this morning to get the missing tubes and nuts. The guy I talked to just needed my name. Don't forget to mention that you might be the first 6 orders to get the clear top rca tube.


 
   
  Thanks - I sent them an email, but I will likely call them tomorrow if I don't hear back. I will double check on the #4 small nuts. I did a full inventory check and found everything was in order other than the tubes.


----------



## DefQon

Yeah sometimes there is a bit of missing parts from the inventory as sometimes they are short on parts for specific orders, this happened to me and Eileen informed me anything missing will be posted out to me.


----------



## calipilot227

I was missing the #4 nuts in my kit as well, nothing a quick trip to Radioshack didn't fix. I did however get the free Speedball upgrade


----------



## proid

Quote: 





palmfish said:


> I used to have D7000's and still have D2000's and I suspect they will sound great with the Crack. In my experience, the Denon's are more or less unaffected by high output impedance amps because their impedance is stable across the entire frequency range and they have a lot of mechanical damping. In other words, they do not rely on electrical damping to control the driver.


 
   
  Eh i think it not only about high impedance of the crack, it also about power output with low impedance headphones. These Denon should pair with optimal amps which have low output impedance and high output power.


----------



## Doc B.

Sorry about the tubes, guys. We've been working at double speed to keep up lately and it appears that four kits got shipped without them. Eileen is sending them out as soon as she confirms that a customer needs them. So do let us know if you were one of the folks who kit was shorted. I have the pleasure of having some minor surgery today so we may not be at the office if you call, but do leave a message.


----------



## palmfish

telecaster said:


> Sweet choice of finishes!!
> If I could lay my hand on a kit, I'll be inspired to do a dark gray hammertone and a black stain




That was actually my first choice. Lowes didnt have Dk Grey hammertone - only Dk Bronze, so I adjusted my color scheme to accomodate.


----------



## kozmos

man, i can't wait until i get my crack, got all parts stacked up for it at home


----------



## brunk

Quote: 





kozmos said:


> man, i can't wait until i get my crack, got all parts stacked up for it at home


 
  Hehe same here, I dropped about $180 for everything including a nice size electrical toolbox for it all to go in (thanks parts-express). I'm chomping at the bit!


----------



## DownhomeUpstate

Quote: 





kozmos said:


> man, i can't wait until i get my crack, got all parts stacked up for it at home


 
  Hey Kozmos,
   
  What mods are you planning for your Crack?
   
  Mike


----------



## DownhomeUpstate

Quote: 





brunk said:


> Hehe same here, I dropped about $180 for everything including a nice size electrical toolbox for it all to go in (thanks parts-express). I'm chomping at the bit!


 
  Ditto Brunk,
   
  What have you got in store for yours?
   
  M


----------



## kozmos

Cool 

 I got mills mra5 resistors for the PSU, neutrik lock jack, and mundorf mkp capacitors that i will use as output caps.
 I will also buy the speedball upgrade but not until October becouse im planning on buying a new dac next month, plus i have to get GTA V.
  
  Any suggestions on other cheap and worthwhile upgrades?


----------



## brunk

Quote: 





downhomeupstate said:


> Ditto Brunk,
> 
> What have you got in store for yours?
> 
> M


 
  I'm going to stick with stock Crack for a while so i understand its sound sig, then i'll install the speedball. After that i will do some very minor tube rolling and perhaps some cap upgrades, but nothing off the wall lol. For cosmetics, I'm thinking about doing a complete Olive Drab, with black spray paint stenciling to give it a funky 70's military look. I think i would stencil something like "BottleHead Crack" on one side and " Danger: High Voltage" on the other. We'll see what else i come up with, but im pretty set on the retro military look.


----------



## DownhomeUpstate

I'm new here, so I guess I should go first.
   
  Ordered my Crack w/Speedball during Doc B's special, and I've stocked up, too. Eagerly awaiting delivery.
   
  Picked up a Precision Electronic Corp. 50K log taper dual deck pot, a pair of 100 uf metalized polypropylene film caps to replace the electrolytics in the signal path, a Neutrik 1/4" locking panel jack w/silver contacts, some Cardas CTFA RCAs, Belton tube sockets, Neotech UP-OCC 20 GA. for power, 22 and 24 ga solid silver for signal wiring. That's it for now.
   
  Never had a set of headphones before worth speaking of. Just took delivery of a lightly used HD600 and a Stefan Audio Art Equinox 6' cable. Looking forward to driving the HD600's with this rig. After its built, I'll undoubtedly lose some cash rolling tubes.
   
  Sources include Mac2Music Mac Mini w/Pure Music, Halide DAC HD, Oppo 93 and a Merrill ES-R1 w/Jelco 750D, Denon DL-103R, Audio Sensibility hot-rodded Jelco tonearm cable, Cinemag 3440A step-ups, and a Bottlehead Seduction w/C4S with Dynamicap-E coupling and output caps. 2-channel amp is a Bottlehead 2A3 Stereomour that I'm in the process of tweaking a bit.
   
  NIce to be here, and look forward to listening and learning.
   
  MIke


----------



## DownhomeUpstate

Oops, sorry. Didn't see your replies before I posted again.


----------



## brunk

Quote: 





downhomeupstate said:


> I'm new here, so I guess I should go first.
> 
> Ordered my Crack w/Speedball during Doc B's special, and I've stocked up, too. Eagerly awaiting delivery.
> 
> ...


 
  Where did you pick up the caps, pot, sockets and wire?


----------



## J-Pak

Has anyone ordered Axon caps from Zalytron? A strange experience... almost like they _don't_ want to sell people stuff.


----------



## DownhomeUpstate

Quote: 





brunk said:


> Where did you pick up the caps, pot, sockets and wire?


 
  Got the caps from Parts Express - nothing fancy - Dayton Audio, but Doc (and I think Paul B) mentioned on the BH Crack forum thread that any film cap would do. And the price was right: less than $27 ea.
   
  Pot was from DigiKey - their part no. KKA5031S28-ND  I read somewhere on the BH forum that some folks found that using a 50K pot was quieter than the stock pot at 100K. I guess I'll find out. Doc B likes the PEC pots for the money.
   
  Sockets and silver wire were from Handmade Electronics. THeir prices on silver wire can't be beat. http://www.hndme.com/productcart/pc/viewCat.asp
   
  Neotech Up-OCC copper wire was from parts connexion (pcx). pcx is still running their 20% off storewide sale through August.


----------



## kozmos

I've been looking into the silver wire myself, does the wire have any sort of insulation or do i have to apply that by my self?
 Are you gonna use the silver wire between rca and the volume control?


----------



## DownhomeUpstate

Quote: 





kozmos said:


> I've been looking into the silver wire myself, does the wire have any sort of insulation or do i have to apply that by my self?
> Are you gonna use the silver wire between rca and the volume control?


 
  It's uninsulated. The owner of Handmade says that because it is soft-annealed silver, it doesn't work with directly-applied insulation. You can use teflon tubing that you can buy there or elsewhere (really cheap to buy), or maybe try the nail polish thing.  Check this out:
   
  http://www.hndme.com/silverwire.html
   
  I am going to run the silver from the RCAs to the pot, from the pot to the 12AU7 driver, from the 12AU7 to the 6080 output tube, and from the 6080 to the Neutrik panel jack, and everywhere else in the signal chain in-between.


----------



## kozmos

Thanks, Im gonna read it tonight.
 What's the difference between the original sockets and the once they are selling?


----------



## DownhomeUpstate

The Belton sockets (Korean manufacture) are well made, with glass fiber-filled plastic sockets instead of ceramics, and use tight-fitting phosphor brass pins. They are cheap, well made and have a good rep. (You can spend way too much money on teflon, gold-plated sockets that look fabulous, can make audiophools like me drool over the purity of the materials used to transfer signal, and probably add nothing to discernible sound quality. Or, you can spend 2 or 3 bucks and get the Beltons.) 
   
  There is absolutely nothing wrong with the stock ceramic tube sockets. I just like these better. And, a tighter and more consistent grip on the pins can't be a bad thing.


----------



## kozmos

The three wires that goes from the PSU to the output socket, are you gonna use silver wire there too?
 As i see it, that is not a part of the signal path even though they power the output tube, am i right?


----------



## skeptic

Just a quick pointer for all the new/soon to be crackheads - if you are going to put in film output caps at some point, make sure you install fly leads _before_ putting mounting your speedball boards. If you search this thread for "fly leads" you will see pics posted by beefy and others illustrating this.


----------



## DownhomeUpstate

Quote: 





kozmos said:


> The three wires that goes from the PSU to the output socket, are you gonna use silver wire there too?
> As i see it, that is not a part of the signal path even though they power the output tube, am i right?


 
  That would be the heater power, and B+ for the output tube. Thats where you use the 600 vdc rated hook-up wire, in this case, the Neotech UP-OCC stuff.


----------



## DownhomeUpstate

Quote: 





skeptic said:


> Just a quick pointer for all the new/soon to be crackheads - if you are going to put in film output caps at some point, make sure you install fly leads _before_ putting mounting your speedball boards. If you search this thread for "fly leads" you will see pics posted by beefy and others illustrating this.


 
  Yup, Beefy rules. The pics of his build are great.


----------



## kozmos

By fly leads you mean soldering wires into the output caps terminals?


----------



## brunk

Quote: 





kozmos said:


> By fly leads you mean soldering wires into the output caps terminals?


 
  Yup.


----------



## brunk

Quote: 





downhomeupstate said:


> Got the caps from Parts Express - nothing fancy - Dayton Audio, but Doc (and I think Paul B) mentioned on the BH Crack forum thread that any film cap would do. And the price was right: less than $27 ea.
> 
> Pot was from DigiKey - their part no. KKA5031S28-ND  I read somewhere on the BH forum that some folks found that using a 50K pot was quieter than the stock pot at 100K. I guess I'll find out. Doc B likes the PEC pots for the money.
> 
> ...


 
  Well i broke down and bought the wire, pot, and caps lol. Came out to be around $150 for it all shipped. Only thing i changed was i went with the alps blue velvet, i read somewhere that it tracked just fine at low levels. *One question though, since its a 50k pot, do i need to install any resistors in series, or does it not matter? thanks.*


----------



## skeptic

Exactly.  Here's an old pic of my amp with fly leads and zip tie mounts installed, but before I put in the speedball and film caps.  Otherwise, your stock output caps simply attach directly to terminals 6 + 7 and 9 + 10.
   

   
  edit: looks like brunk beat me to the punch while I was digging for the pic 
	

	
	
		
		

		
			





  In any event, for the easiest installation, I'd build stock + fly leads + zip tie mounts.  Then do the speedball.  Then add in the big caps.  Otherwise things get a bit cramped.


----------



## kozmos

Nice 

 These seems to be fairly cheap if you want gold plated and teflon, they don't have the pins so you can put an adaptor on but they look cool anyway.
  http://www.partsconnexion.com/socket_tefcom.html


----------



## kozmos

Yea, i've had that in mind before, i probably put my caps on the shelf until i get my speedball.
 It's a smart idéa, should make it easier to line up all the mounts in the right places!


----------



## palmfish

Quote: 





skeptic said:


> Exactly.  Here's an old pic of my amp with fly leads and zip tie mounts installed, but before I put in the speedball and film caps.  Otherwise, your stock output caps simply attach directly to terminals 6 + 7 and 9 + 10.


 
   
  I googled the nomenclature on your volume pot and found a link to TDK. Is this a worthwhile upgrade? Guys on the forums are telling me to get a Korean ladder type stepped attenuator. Don't know how I feel about that...


----------



## DefQon

I'm using a Dact ct2 stepper in mine. Great pot.


----------



## amcananey

palmfish said:


> I googled the nomenclature on your volume pot and found a link to TDK. Is this a worthwhile upgrade? Guys on the forums are telling me to get a Korean ladder type stepped attenuator. Don't know how I feel about that...




I installed a $100 TKD potentiometer in my Crack. Then I built a Quickie with a $26 Vintage Audio Lab (VALab on eBay) ladder-style stepped attenuator. If I were doing it over again, I would have put a VALab attenuator in my Crack, too. I'm building a Smack and a S.E.X. and have already purchased VALab attenuators for both.

To me, the TKD isn't worth the money, whereas the VALab is worth MORE than what it costs. I keep thinking there is some mistake in their price list they just haven't realized it yet...


----------



## amcananey

To be clear, the TKD is excellent, and I don't have any complaints about it other than its cost. An Alps Blue pot costs about $15. I'm not convinced I could tell the difference between the TKD and an Alps Blue in a blind test.


----------



## Greed

Quote: 





amcananey said:


> I installed a $100 TKD potentiometer in my Crack. Then I built a Quickie with a $26 Vintage Audio Lab (VALab on eBay) ladder-style stepped attenuator. If I were doing it over again, I would have put a VALab attenuator in my Crack, too. I'm building a Smack and a S.E.X. and have already purchased VALab attenuators for both.
> 
> To me, the TKD isn't worth the money, whereas the VALab is worth MORE than what it costs. I keep thinking there is some mistake in their price list they just haven't realized it yet...


 
   
  Adam, how is the VALab attenuator vs some of the more popular stepped offerings like Goldpoint, DACT, etc.? Is it really the best value?


----------



## Beefy

downhomeupstate said:


> Yup, Beefy rules. The pics of his build are great.




ROAR! Pics of my cap mounting and fly leads are in the Crack link in my sig, no need to search.

Best advice I can offer, is that whatever upgrades you think you might want, prep for it from the start. Virtually impossible to switch out tube sockets after the fact, a new volume pot with different mounting holes will kill the finish on the top plate, as will holes for cap mounting.


----------



## DownhomeUpstate

Quote: 





brunk said:


> Well i broke down and bought the wire, pot, and caps lol. Came out to be around $150 for it all shipped. Only thing i changed was i went with the alps blue velvet, i read somewhere that it tracked just fine at low levels. *One question though, since its a 50k pot, do i need to install any resistors in series, or does it not matter? thanks.*


 
  Nope, no additional padding necessary.


----------



## Beefy

Quote: 





downhomeupstate said:


> Nope, no additional padding necessary.


 
   
  As long as your source is good with 50k (and the _vast_ majority are) then no resistor padding is required.
   
  But in my case, I did add an extra 50k back in series with a 50k pot. The Crack has a pretty damn high gain - the resistors give more usable range on the pot, while still letting you deafen yourself at max volume.


----------



## amcananey

I haven't tried the others. The VALab costs $26, shipped. A Goldpoint costs $149, plus shipping. Value is subjective. But the VALab seems robustly made with quality resistors. It has enough steps for me to find a suitable volume level. Does the Goldpoint sound better? Well, first you have to believe the potentiometer / attenuator makes a significant difference in the first place. Then you have to believe that the Goldpoint sounds $135 better than another quality stepped attenuator (I.e., the VALab). For $135, you can buy upgraded film caps, a bunch of exotic tubes, or put the money toward a pair of HD800s. Then again, maybe the Goldpoint also makes you breakfast...


----------



## amcananey

beefy said:


> ROAR! Pics of my cap mounting and fly leads are in the Crack link in my sig, no need to search.
> 
> Best advice I can offer, is that whatever upgrades you think you might want, prep for it from the start. Virtually impossible to switch out tube sockets after the fact, a new volume pot with different mounting holes will kill the finish on the top plate, as will holes for cap mounting.




FWIW, the VALab is damn close to a drop-in replacement for the stock pot. The anti-rotation pin fits perfectly, you just need to widen the main hole by a hair's breadth, and I do mean a hair's breadth. 30 seconds of work and you're done.


----------



## brunk

Quote: 





downhomeupstate said:


> Nope, no additional padding necessary.


 
 Thanks, I also bought a PANASONIC EET-ED2E221BA 220uf 250v for the last power supply cap upgrade
  
 Darn thing is hard to find, had to buy some extra stuff on that website to make it worth my while.


----------



## amcananey

brunk said:


> Thanks, I also bought a PANASONIC EET-ED2E221BA 220uf 250v for the last power supply cap upgrade
> 
> 
> Darn thing is hard to find, had to buy some extra stuff on that website to make it worth my while.




Out of curiosity, why are you replacing the stock cap for another electrolytic, instead of for a film cap?


----------



## caracara08

Ugh, apparently the Alps velvet pot I bought, the nice volume know and the rhodium rca jacks all don't fit without some dremel work


----------



## brunk

Quote: 





amcananey said:


> Out of curiosity, why are you replacing the stock cap for another electrolytic, instead of for a film cap?


 
  It has better specs than the stock that will result in lower noise floor. $4 vs. $60 for a film to make a minor difference is too far in the realm of diminishing returns for me.


----------



## ULUL

I thought I posted this earlier today but don't think it took.
   
  Quick question.
   
  Per my understanding, for the Crack/Speedball combo, this is the order of improvements people are doing starting with the greatest difference for the $ and then going towards the points of diminishing return. 
   
  1. Tube rolling.
  2. Attenuator.  (I got the VaLab stepped.  Thanks Americaney.   I listen at low volumes and balance matters.)
  3. Caps.  I'm still not sure exactly what Caps does - is it a very clear auditory difference?  What would I hear - more detail?  Warmth?  Speed? 
  4. ?? What is after caps?
   
  Thanks,
  UL


----------



## brunk

Quote: 





ulul said:


> I thought I posted this earlier today but don't think it took.
> 
> Quick question.
> 
> ...


 
  I think it goes like this from what i gathered:
  1. Speedball
  2. Synergistic tube combo (way too much money can be spent here)
  3. Output coupling caps (typically $60+)
  4. Attenuator for better low level tracking and maybe some resistors to attenuate the signal to your liking ($15-150)
  5. Last power supply cap ($4-60)
  6. High quality signal/power wire, silver solder (varies too much, maybe start around $100 for the whole thing)
  7. Misc. stuff like RCA jacks, Neutrik jack, tube sockets ($4-50 a piece)


----------



## palmfish

I have finished my Crack..well, mostly. I decided to build it bone stock after all - though I'm still seriously considering the VALab potentiometer. I also still have to stain and Satin Poly the base. Resistance checks are all good. Unfortunately, it seems I melted my power switch (it does the belly flop with no clicky) so I need to get another one. 
	

	
	
		
		

		
			





 I was really excited about seeing those tubes glow for the first time and plugging my headphones in...hoping I can find a switch off-the-shelf at a neighborhood brick and mortar store.
   
  And the pics...


----------



## Beefy

Quote: 





brunk said:


> It has better specs than the stock that will result in lower noise floor. $4 vs. $60 for a film to make a minor difference is too far in the realm of diminishing returns for me.


 
   
  That's silly. Just put a small film cap in parallel to the last electrolytic like almost every other Crack-upgrader does, rather than replacing it with a 'better' electrolytic.
   
   
  Quote: 





ulul said:


> 1. Tube rolling.
> 2. Attenuator.  (I got the VaLab stepped.  Thanks Americaney.   I listen at low volumes and balance matters.)
> 3. Caps.  I'm still not sure exactly what Caps does - is it a very clear auditory difference?  What would I hear - more detail?  Warmth?  Speed?
> 4. ?? What is after caps?


 
   
  Speedball is by far the most important upgrade. Without the Speedball, tubes do make a BIG difference. But after installing the Speedball the differences between the same tubes are far more subtle and it is far less important to buy a whole heap of fancy tubes.
   
  I installed the attenuator before any other changes, so I'm not sure where that fits in a ranking, but it is still an essential upgrade IMO. If only for physical interaction and volume matching and not for sound quality.
   
  Output caps make less difference than the Speedball, but are still quite important.
   
  I also installed Teflon tube sockets and fancy RCA jacks...... but that is only because I was bored, wanted it to look/interact 'better', and these have no audible benefit whatsoever. I also switched out a few resistors to higher reliability/precision versions, but that was only because I was already making a Mouser and PCX order for other things.
   
  So for a lazy person summary:
   
  1. Speedball
  2. Attenuator
  3. Caps
  4. Assuming you did the Speedball, _maybe_ tubes


----------



## DefQon

The crap thing about those Valab attenuator's is the build quality and the tight tension between the stepper inside, you almost have to put force into turning the damn thing.
   
  IME boutique film caps do more good and benefit in the signal path or for decoupling, I found no differences whatsoever swapping out the stock 250v Panny lytics for the PS to a Jensen, Rifa, Mundorf, Wima and Auricap film cap at all. Since the stock Panny's became a good source for another amp, I replaced mine with NOS German Roederstein metal caps, very low ESR and very high ripple with a high rated life span at normal operating temps, better than any modern in production lytic cap's tech specs wise.
   
  Don't be fooled by the looks and size of moar is better. Save your money on appropriate upgrades/mods such as the speedball, tubes and pots if you're feeling it.


----------



## kozmos

What does the smaller film cap improve when you put it parallel to the last cap in the psu?


----------



## amcananey

Palmfish,

Very nice build. What do you mean when you say you melted your power switch? I assume you mean you applied too much heat while soldering it in, not that it melted when you turned the amp on, is that correct?

If the former, you're OK to get another switch to replace it. If the latter, then you have a problem you need to fix first. 

Best regards,
Adam


----------



## W0lfd0g

Until very recently I agreed whole heartedly with Beefy about the impact of tube rolling on the Crack + SB. 

 I have spent a bucket load of money on tubes in search of that enigmatic "perfect sound", money that I thought I had flushed down the toilet. 
   
  Have found a combination that works for me:

 Driver tube: Mullard E80CC (Philips made)
 Output tube: GEC 6AS7G Brown Base

 Has anyone else tried this combination?

 Only a matter of hours ago I described tube rolling as "Emperor's New Clothes" syndrome to a fellow forum member.  I have stuck with the combination noted above for perhaps fifty hours - Maybe I didn't give tubes long enough to burn in.  Maybe I am a victim of the "mass psychosis". 

 In any case, I am hearing clarity, bass extension and speed without the sacrifice of warmth or treble roll off to a degree I have never heard before in this system or any other.  Is the difference subtle? Certainly, and a good thing too as I don't want to lose the "Crack" sound.  Am I sticking with these tubes?  You bet! 

 The context?  BH Crack with Speed Ball, cap upgrades, 100K Blue Alps pot, driven by a Meier Audio Stage DAC playing FLAC files.  Headphones are Beyer T90s.

 My Nirvana... until the urge to tinker strikes again.  Or until I have paid off my tube debt and can afford to get the BH Mainline.


----------



## amcananey

kozmos said:


> What does the smaller film cap improve when you put it parallel to the last cap in the psu?




In theory, at least, film caps discharge faster than electrolytics. So at least in this application (I.e., the last power supply cap), my understanding is that by paralleling a small value film cap, the film cap will dump its charge first, giving the electrolytic enough time to react and deliver the bulk of the charge. 

FWIW, I initially bypassed the last power supply cap with a 2.2uf film cap, but out of boredom, I now plan on replacing it with two 100uf oil-filled caps I got off eBay for $15, each, shipped. Boutique caps aren't necessary or advantageous in that position.


----------



## dsound

Congrats on finishing the build!  Looks great.  If I remember correctly Bottlehead will send you a new switch if you ask nicely 
	

	
	
		
		

		
			




  Quote: 





palmfish said:


> I have finished my Crack..well, mostly. I decided to build it bone stock after all - though I'm still seriously considering the VALab potentiometer. I also still have to stain and Satin Poly the base. Resistance checks are all good. Unfortunately, it seems I melted my power switch (it does the belly flop with no clicky) so I need to get another one.
> 
> 
> 
> ...


----------



## Beefy

Quote: 





kozmos said:


> What does the smaller film cap improve when you put it parallel to the last cap in the psu?


 
   
  Drops the ESR and reduces ripple. To a far better extent than even the best electrolytic I might add.
   
   
  Quote: 





w0lfd0g said:


> Until very recently I agreed whole heartedly with Beefy about the impact of tube rolling on the Crack + SB.


 
   
  I'm not saying it removes the benefit of tube rolling entirely, but the Speedball absolutely reduces the difference.
   
  It is my semi-educated opinion that a 'good' tube is one that copes with an imperfect load better than a 'bad' tube. A CCS is almost a perfect load, so the relative benefits of a good tube diminish.


----------



## amcananey

FWIW, with my Speedballed Crack, I would also say that the differences among tubes have been very, very minor, to the point where I don't trust any fleeting impressions I have in the least. The only differences between tubes that are worth paying attention to are (i) microphonics, and (ii) noise (in other words, not any illusory differences in bass, treble, midrange, soundstage, dynamics, etc.). I suspect microphonics and noise have more to do with individual tube variation and basic tube design, rather than "premium" or "boutique" tube manufacturers. 6080 tubes and 12AU7s / 12BH7s seem to be the quietest of the tube families I've tried, with no particularly noteworthy differences among brands.
   
  Here is my takeaway recommendation after having tried a fair number of tubes: stick with what came with your Crack and be happy. You are unlikely to noticeably improve the sound by buying other tubes. You are much better off spending the money you would have spent on tubes on the Speedball.


----------



## palmfish

Quote: 





amcananey said:


> Palmfish,
> 
> Very nice build. What do you mean when you say you melted your power switch? I assume you mean you applied too much heat while soldering it in, not that it melted when you turned the amp on, is that correct?
> 
> ...


 
   
  Adam and dsound:
   
  Thanks! I'm very pleased with it overall. I had my daughter braid the RCA to pot wires for me.. 
	

	
	
		
		

		
		
	


	



   
  Yes the switch got too hot while soldering. I could blame it on my 13 year-old son who did most of the earlier soldering, but I accept full responsibility 
	

	
	
		
		

		
		
	


	




. I live in Seattle and can't stand the thought of waiting a few days for a part that is sitting on a shelf an hour away...LOL! But I'm leaving on a one week business trip tomorrow and want to finish my Crack today (I'm Jonesing, you might say...LOL) so I'll go pick one up retail.
   
  One other observation - while building, I saw the 2010 revision with the wire going to 14U to reduce noise - with 2 wires, one cap lead and a resistor lead it got very tight in there - I ended up heating and cooling and reheating that point several times. It was one of the most difficult and confusing parts of the build. Resistance checks out fine, but it could look prettier...
   
  And thanks for all your info here and on the other dedicated forum. I didn't put together 2+2 who you are until I saw your signiature here.


----------



## kozmos

I've seen people soldering smaller film caps prallel with their output film caps, what's the purpose of that?


----------



## brunk

Quote: 





beefy said:


> That's silly. Just put a small film cap in parallel to the last electrolytic like almost every other Crack-upgrader does, rather than replacing it with a 'better' electrolytic.
> 
> 
> 
> ...


 
  Oh ok. Do you have a reccomendation for a cap? Thanks.


----------



## palmfish

Quote: 





amcananey said:


> FWIW, with my Speedballed Crack, I would also say that the differences among tubes have been very, very minor, to the point where I don't trust any fleeting impressions I have in the least. The only differences between tubes that are worth paying attention to are (i) microphonics, and (ii) noise (in other words, not any illusory differences in bass, treble, midrange, soundstage, dynamics, etc.). I suspect microphonics and noise have more to do with individual tube variation and basic tube design, rather than "premium" or "boutique" tube manufacturers. 6080 tubes and 12AU7s / 12BH7s seem to be the quietest of the tube families I've tried, with no particularly noteworthy differences among brands.
> 
> Here is my takeaway recommendation after having tried a fair number of tubes: stick with what came with your Crack and be happy. You are unlikely to noticeably improve the sound by buying other tubes. You are much better off spending the money you would have spent on tubes on the Speedball.


 
   
  Re: tube rolling. I plan on installing Speedball too and although I've read a lot about the various tube options, in the end I decided to not pursue boutique (expensive) tubes for my Crack. That said, I did buy a CBS (Hytron) 6AS7G (black plate) and CBS 5814A (black plate D-Getter). I love the "big bottlehead" look and I dig the tubes both having matching orange CBS silkscreening.


----------



## amcananey

This cap would be perfectly fine for bypassing the last cap in the power supply.
   
  If you want to replace that cap entirely, and don't want to buy a film cap (which will run you about $65), you can wire two of these in parallel, though obviously, space and mounting will be an issue! (These are the ones I bought - I will probably just mount them outside the case.)
   
  Best regards,
  Adam


----------



## amcananey

Palmfish,
   
  Yep, 14U is a complete nightmare. Don't worry, you're not the only one that had trouble there!
   
  Best,
  Adam


----------



## Beefy

Quote: 





kozmos said:


> I've seen people soldering smaller film caps prallel with their output film caps, what's the purpose of that?


 
   
  Very little, in comparison. Once you have any film cap in there instead of an electrolytic, you have made the vast majority of potential improvements. Of course, you can read a whole heap of audiophile stuff and people will talk about more holographic soundstage, sparkling highs, generic audio improvement #54 with X/Y/Z cap combination...... to put it diplomatically, I'm skeptical.
   
   Quote
  :


amcananey said:


> Yep, 14U is a complete nightmare. Don't worry, you're not the only one that had trouble there!


 
   
  I moved some stuff to 14L; no problems.


----------



## palmfish

Phew!
   
  Hey, quick question... I'm browsing online and found this "illuminated rocker switch." It's rated 15 amp instead of 5 amps at 120 VAC. I have no idea what other specs (contact resistance?) the stock switch is rated at.
   
  I like the idea of having one that lights up - do you think it's compatible?
   
  http://www.e-switch.com/product/tabid/96/productid/113/sename/r1966-series-illuminated-rocker-switches/default.aspx


----------



## brunk

For those interested in a decent dremel set i found a pretty good deal on a variable speed 8k-35k RPMs. Chicago Electric Variable Speed Rotary Kit use 20% off code '94990488' it comes out to $25 shipped.


----------



## kozmos

Okay, one more question.
 Did the crack come with enough wire to do the fly wiring or do i have to buy some more ?


----------



## brunk

Quote: 





kozmos said:


> Okay, one more question.
> Did the crack come with enough wire to do the fly wiring or do i have to buy some more ?


 
  Most people say they end up with about a foot left of each wire, so long as you don't mangle up your cuts.


----------



## brunk

Quote: 





amcananey said:


> This cap would be perfectly fine for bypassing the last cap in the power supply.
> 
> If you want to replace that cap entirely, and don't want to buy a film cap (which will run you about $65), you can wire two of these in parallel, though obviously, space and mounting will be an issue! (These are the ones I bought - I will probably just mount them outside the case.)
> 
> ...


 
  Dang, those motor runs caps are almost 6in. long! I don't even think those would fit at all, even if you mounted them vertically and raised the chassis with feet.


----------



## ben_r_

Quote: 





kozmos said:


> Okay, one more question.
> Did the crack come with enough wire to do the fly wiring or do i have to buy some more ?


 

 Ha I ended up with almost enough wire to do TWO Crack builds. It all depends on how good you are at soldering and how much experience you have with building stuff like this. You do not have to follow the Crack manuals measurements, they are all way longer than you should need but are so to make working with the runs easier. Even if you do, yes there should be enough to make some short fly leads for custom film output caps. And if you dont, just pick up some 20AWG solid or stranded wire from online or a store for under $5 for 25ft or so and youll have plenty.


----------



## brunk

Quote: 





brunk said:


> Dang, those motor runs caps are almost 6in. long! I don't even think those would fit at all, even if you mounted them vertically and raised the chassis with feet.


 
  Well, I found a nice cap that doesn't cost alot with shipping lol. MKP Audio 2.2uf 250v $3.50 shipped.


----------



## amcananey

Quote: 





ben_r_ said:


> Even if you do, yes there should be enough to make some short fly leads for custom film output caps. And if you dont, just pick up some 20AWG solid or stranded wire from online or a store for under $5 for 25ft or so and youll have plenty.


 
   
  I would stick to solid core wire and avoid stranded. You might get away with stranded for the fly leads, but in general, solid core is much easier to work with in these applications.
   
  Best,
  Adam


----------



## amcananey

Quote: 





brunk said:


> Well, I found a nice cap that doesn't cost alot with shipping lol. MKP Audio 2.2uf 250v $3.50 shipped.


 
   
  Well, yeah, but that's a 2.2uf cap. Suitable for bypassing the electrolytic in the power supply, but not replacing it. I'm not claiming you need to replace it (in my Crack I currently have the cap bypassed with a 2.2uf ClarityCap ESA), but the motor run caps are 100uf each, so you can take two of them to replace the last power supply cap.
   
  Also, FWIW, the cap I suggested for bypassing (instead of replacing) the electrolytic only cost $1.72, and is from a brand and vendor that are well-known (though I assume shipping adds to the price). I don't know anything about the cap you linked to, so I'm not saying it isn't just as good. If you decide to bypass all three electrolytics in the power supply, the cost would probably be about the same.


----------



## brunk

Quote: 





amcananey said:


> Well, yeah, but that's a 2.2uf cap. Suitable for bypassing the electrolytic in the power supply, but not replacing it. I'm not claiming you need to replace it (in my Crack I currently have the cap bypassed with a 2.2uf ClarityCap ESA), but the motor run caps are 100uf each, so you can take two of them to replace the last power supply cap.
> 
> Also, FWIW, the cap I suggested for bypassing (instead of replacing) the electrolytic only cost $1.72, and is from a brand and vendor that are well-known (though I assume shipping adds to the price). I don't know anything about the cap you linked to, so I'm not saying it isn't just as good. If you decide to bypass all three electrolytics in the power supply, the cost would probably be about the same.


 
  Yeah I'm just going to bypass it with that cap i got. PE wants to charge like $7 for shipping lol.


----------



## brunk

Quote: 





brunk said:


> Yeah I'm just going to bypass it with that cap i got. PE wants to charge like $7 for shipping lol.


 
  Well, I just added up my total cost of the crack + upgrades and misc. tubes. Comes out to $500, not including the $300 i spent on a wide variety of tools that i really needed anyway. Not too bad honestly considering the top quality parts. Only things i wont be upgrading for now is the input and output jacks lol. Everything else is pretty much upgraded.
   
  Crack + Speedball (promo) = $290
  MKP Audio PSU Bypass cap $3.50
  solid Silver signal wire + teflon tubing = $37.25
  alps 50k pot, up-occ power wire and tube sockets = $41
  dayton film output coupling caps $60
  misc. tubes $65
   
  Total: $497


----------



## Nic Rhodes

I can understand 100microFarad  film caps for an upgrade, but have some 100microFarad + 100microFarad blackgates hanging around from years ago and an old project (405v). How do these compare nowdays (15 years on...)?


----------



## Seamaster

Quote: 





palmfish said:


> Re: tube rolling. I plan on installing Speedball too and although I've read a lot about the various tube options, in the end I decided to not pursue boutique (expensive) tubes for my Crack. That said, I did buy a CBS (Hytron) 6AS7G (black plate) and CBS 5814A (black plate D-Getter). I love the "big bottlehead" look and I dig the tubes both having matching orange CBS silkscreening.


 
  Congrats on your amp
  Quote: 





palmfish said:


> Phew!
> 
> Hey, quick question... I'm browsing online and found this "illuminated rocker switch." It's rated 15 amp instead of 5 amps at 120 VAC. I have no idea what other specs (contact resistance?) the stock switch is rated at.
> 
> ...


 
  I think old school toggle switch looks better with Crack.


----------



## mellowbob

Well I couldn't wait for the missing #4 nuts + tubes so I went to my local Home Depot and picked up some nuts so I can continue my build.
For the wooden stand, I went for the weathered look.

Finished product minus tubes:


Now I just need to get the tubes in, get some listening time, then start working on the speedball!


----------



## palmfish

Quote: 





mellowbob said:


> Well I couldn't wait for the missing #4 nuts + tubes so I went to my local Home Depot and picked up some nuts so I can continue my build.
> For the wooden stand, I went for the weathered look.
> 
> Finished product minus tubes:
> ...


 
   
  Nice, clean build! Congrats!


----------



## palmfish

Here's my finished product. I'm working out a couple of small bugs but she looks good and is playing music very well


----------



## brunk

Quote: 





palmfish said:


> Here's my finished product. I'm working out a couple of small bugs but she looks good and is playing music very well
> 
> 
> 
> ...


 
  Looks good! What is it sitting on top of?


----------



## palmfish

Quote: 





brunk said:


> Looks good! What is it sitting on top of?


----------



## brunk

Quote: 





palmfish said:


>


 
  I had a feeling it was a vintage Pio! Looks like a cozy place to wind down in the evening too


----------



## palmfish

Quote: 





brunk said:


> I had a feeling it was a vintage Pio! Looks like a cozy place to wind down in the evening too


 
   
  Yeah, it's pretty cozy. I like it...  (my vintage Pioneer and Crack are only in that spot temporarily while I play with them, BTW)


----------



## brunk

Very nice! Now you must tell me what TT is hiding under that dustcover 
	

	
	
		
		

		
			





 I almost went with building a phono-pre instead of crack, i think that will be my next project...
  Quote: 





palmfish said:


> Yeah, it's pretty cozy. I like it...


----------



## ben_r_

Quote: 





palmfish said:


> Yeah, it's pretty cozy. I like it...  (my vintage Pioneer and Crack are only in that spot temporarily while I play with them, BTW)


 
  Arent the Squeezebox's amazing?! I have them all over the house and all linked to my server. They have been nothing but wonderful! The E1 is what I use to feed my Crack too. Im a Denon guy though. Never much liked Pioneer. And I dont have a pair of HD-800's yet  sadly.


----------



## palmfish

Quote: 





brunk said:


> Very nice! Now you must tell me what TT is hiding under that dustcover
> 
> 
> 
> ...


 
   
  Ha ha, every time I sit down, I read your next post and get up to take another picture...lol! Maybe you'd like a tour of my house? I have a home theater and a Porsche too... 
	

	
	
		
		

		
		
	


	



   
  Here's my turntable. It's a Pioneer PL-707. Enjoy!


----------



## palmfish

Quote: 





			
				ben_r_ said:
			
		

> Arent the Squeezebox's amazing?! I have them all over the house and all linked to my server. They have been nothing but wonderful! The E1 is what I use to feed my Crack too. Im a Denon guy though. Never much liked Pioneer. And I dont have a pair of HD-800's yet  sadly.


 
   
  Yes, I love mine. I have two - one upstairs in my stereo rig (pictured above) and one downstairs in my home theater. It's a shame Logitech stopped making them...
   
  I have owned Denon too - D7000, D2000, AVR-1900 (old home theater subsequently replaced with a Pioneer AVR 
	

	
	
		
		

		
		
	


	




 ) and my cassette deck which you can just see the corner of in the above picture.


----------



## brunk

Quote: 





palmfish said:


> Yes, I love mine. I have two - one upstairs in my stereo rig (pictured above) and one downstairs in my home theater. It's a shame Logitech stopped making them...


 
  I know, i barely missed the boat on those when i was really getting into this audio hobby! Thanks for the mini tour palmfish 
	

	
	
		
		

		
		
	


	



  I have a 9.2 home theater system consisting of Polk LSI-9s through out (I have their 15s too collecting dust...) and some very nice sealed 8in. passive radiator subs that defy their size, love the zero port chuffing. All hooked up to 2x Emotiva XPA-5's. I'm anxiously awaiting for Emotiva's new Prepro. TV is a lowly 47in. but i am in no rush to upgrade it just yet.


----------



## palmfish

Hey Ben, speaking of the Crack, do you have any "hum" in yours? Mine hums all the time, no matter the volume or source. Same loudness with all my headphones even.


----------



## brunk

Quote: 





palmfish said:


> Hey Ben, speaking of the Crack, do you have any "hum" in yours? Mine hums all the time, no matter the volume or source. Same loudness with all my headphones even.


 
  Maybe try switching out tubes, that could be the culprit. /shrug


----------



## ben_r_

Quote: 





palmfish said:


> Hey Ben, speaking of the Crack, do you have any "hum" in yours? Mine hums all the time, no matter the volume or source. Same loudness with all my headphones even.


 

 Nope, mine is dead silent. Have you tried different tubes? I tried a different than stock 6080 and immediately upon powering it on and plugging my HD-650's into it I heard a hiss while no source was plugged in. The stock tube never gave any noise at all. Maybe its coming from your tube? As I understand it the 6080 is known for being noisy and a bit more difficult to "get a good one". Though TONS of people in this thread would be complaining about it if that were the case, so either Bottlehead found a good brand to buy or maybe the other one I got (an RCA) was just no good? I dont know.


----------



## palmfish

brunk said:


> I know, i barely missed the boat on those when i was really getting into this audio hobby! Thanks for the mini tour palmfish
> 
> 
> 
> ...




Nice! I have always liked Polk speakers - I remember when Matthew Polk first hit the market and got rave reviews. Now Polk and Def Tech are owned by the same "mega company" (DEI Holdings). I actually still get by with 5.1.....well, actually 5.2 I guess. I have Def Tech Mythos ST powered towers. 

I almost bought Emotivas first AV Processor too in 2009. It was still buggy and I chickened out - bought a Pioneer AVR instead.

Too bad you missed out of the Squeezebox era. You can still find them on eBay, but at a ridiculous mark up unfortunately. It'll be a dinosaur soon with all the new A/V devices now including network connectivity and DNLA (I think thats what its called) functionality to stream music from your PC directly.

Cheers!


----------



## mellowbob

LOL I'm trying to put together the pcb for the speedball but I'm having a hell of a time soldering the heatsink to the pcb. It keeps draining the heat from my tip!


----------



## brunk

Quote: 





palmfish said:


> Nice! I have always liked Polk speakers - I remember when Matthew Polk first hit the market and got rave reviews. Now Polk and Def Tech are owned by the same "mega company" (DEI Holdings). I actually still get by with 5.1.....well, actually 5.2 I guess. I have Def Tech Mythos ST powered towers.
> 
> I almost bought Emotivas first AV Processor too in 2009. It was still buggy and I chickened out - bought a Pioneer AVR instead.
> 
> ...


 
  Yeah 5.1 is just fine IMO, but getting that feel of "looking up at the band in front row" is an awesome wall of sound. I can also stretch it out really wide and feel like you're in a theater. Cool stuff. Yeah the polks i have i got a killer deal on their refurb warehouse (they are new, with a refurb sticker slapped on the box lol) on ebay during a black friday, best deal of the decade for some high-end speakers. Well i guess high end is a relative term but you get the idea, certainly overkill for a 9.2 system lol.


----------



## palmfish

@ ben - I have another set of tubes on the way so hopefully you're right. I'll see. My only other gripe is small travel on volume knob and channel imbalance. Both were solved by turning down the output level on my E1.

@ mellowbob - I'm anxious to hear how your install goes. I intent to upgrade with Speedball as well in the near future.

@ brunk - I love watching concert videos and listening to multi-channel music too. I bet your system sounds amazing!


----------



## brunk

Quote: 





palmfish said:


> @ brunk - I love watching concert videos and listening to multi-channel music too. I bet your system sounds amazing!


 
  I have to admit. When I popped in the Blu-Ray "Adele - Live at Royal Albert Hall" for the first time i had shed some tears. It sounds like i am right there, and it's a truly amazing performance, i couldn't recommend it higher.


----------



## palmfish

Havent seen it. I will definitely pick it up!


----------



## amcananey

Just got back and am catching up now:

1. 6080s are NOT loud tubes. They are actually quite solid structurally and I have generally found them to be quite quiet, even among different brands, and without regard to price.

2. If you're experiencing hum, try moving your Crack to a different location. In particular, try moving it away from your router, or that squeezebox.

3. I believe another common cause of hum is a problem with your ground channel, or possibly your inputs. In any case, post over at the Bottlehead forum, and they will get you sorted out quite quickly. A properly assembled Crack that isn't close to another device causing interference should be quite quiet (the Speedball makes it even quieter).

4. When soldering the heatsinks for the Speedball, make sure you are using a large tip and maximizing the surface contact between your iron and the heatsink post. With a small tip, you can try forever and you won't be successful. For example, I used a small tip for most of the PCB soldering to avoid solder bridges and overheating those tiny components, but I had to switch tips for the heatsinks. And make sure you apply some solder to your tip before touching the heatsinks, to conduct the heat better. Also, make sure the tip of your soldering iron is extremely clean. If it is oxidized, it won't conduct heat as well. 

Best regards,
Adam


----------



## amcananey

If the gain on the Crack is too high and/or you're experiencing channel imbalance on the volume pot at low volume settings, you can insert resistors on the inputs signals inside the Crack or else use signal attenuators in-line with the signal from your source. For the former, check the Bottlehead forums. This has been described a few times. For the latter, try the Harrison Labs attenuators. Be sure to get the -12 dB version. The smaller values wont do you any good at all.


----------



## palmfish

Good advice Adam, thanks! I will definitely try moving it away from my SBT. I have also gotten good advice at the Bottlehead forums too.
   
  Cheers!


----------



## brunk

Quote: 





palmfish said:


> Good advice Adam, thanks! I will definitely try moving it away from my SBT. I have also gotten good advice at the Bottlehead forums too.
> 
> Cheers!


 
  I think another common issue with the hum is also loose braiding between the input jack and pot. The tighter the better.


----------



## amcananey

The Harrison Labs attenuators are available here. I like using them because they are easily removable if I change sources in the future (to something with a weaker output signal).


----------



## palmfish

Those attenuators are often used in car stereo installations IIRC.
   
  I moved my Crack all over the house - as far away from the router and Squeezebox as I could. The "hum" remains the same. I have noticed that my 6080 tube seems highly microphonic, so maybe it's the culprit after all. Even a gentle tap of the finger anywhere on the amp produces a "tuning fork" type sound in my headphones. Is this typical?


----------



## amcananey

I wouldn't say it is necessarily typical, but not necessarily all that unusual, either. It might not be the 6080. Could be the 12AU7, too.

As for the attenuators, I have them on my Crack. I used it for a quite a while without them, then installed them, and have had plenty of time since. As far as I can tell, all they do is....attenuate the signal. I haven't noticed any change in the quality of the sound. I highly recommend them.


----------



## amcananey

As for the hum, you might want to follow your ground line through the Crack, and reheat all of the relevant solder joints. That has worked for several people in the past. A pain, but worth it.


----------



## palmfish

Quote: 





amcananey said:


> As for the hum, you might want to follow your ground line through the Crack, and reheat all of the relevant solder joints. That has worked for several people in the past. A pain, but worth it.


 
   
  OK, I'll do it. Thanks!
   
  Unfortunately, Im leaving on a business trip tomorrow so it'll have to wait until next weekend. I hate unfinished work...


----------



## amcananey

LOL, then DIY amp-building is not for you...you're never done tweaking!


----------



## calipilot227

Palmfish: My Crack is dead silent as well. Definitely go through and double-check your solder joints. I get a pesky hum from my phonostage, but that's a whole other issue


----------



## palmfish

Quote: 





amcananey said:


> LOL, then DIY amp-building is not for you...you're never done tweaking!


 
   
  Quote: 





calipilot227 said:


> Palmfish: My Crack is dead silent as well. Definitely go through and double-check your solder joints. I get a pesky hum from my phonostage, but that's a whole other issue


 
   
  Oh, don't get me wrong, I'm definitely a "tweaker" - ha ha, get it? Crack...tweaker? Sometimes I "crack" myself up - heh, there I go again... 
	

	
	
		
		

		
		
	


	



   
  Yeah, I will check and recheck all the ground solders. Seems strange though since all my resistance and voltage measurements checked out good. Plus, I don't know if this is a valid test, but just for grins, I connected a wire from the RCA input ground wire directly to the #8 ground screw to see if maybe the ground wasn't solid at the end of the line. Unfortunately, it made no difference in the "hum."
   
  And on a possibly different note, my 6080 is most certainly the tube with the microphonics. Its different than the "hum" so maybe unrelated, but all I have to do is very lightly touch the glass of the 6080 and I can hear it in my headphones. Not so with the 12AU7, which requires an actual tap. Its weird...it's so microphonic that even lightly tapping my headphone cable between two fingers 2 feet away from the amp causes the "tuning fork" noise in my headphones. That can't be normal...
   
  If I'm lucky (but I'm not counting on it), my new tubes will solve the noises. I'm not discouraged though, beyond the hum (which is masked by music mostly), this is already the best-sounding amp I've ever owned. I'm going to stick with it like free base residue to a burnt spoon!
   
  This is going to bug me all week...LOL. Fortunately, I live an hour away from Bottlehead HQ. Paul already invited me to stop by to let them have a look. If all else fails, I'll take him up on his offer.


----------



## amcananey

Microphonics are a funny thing. I certainly won't argue with you, sounds like the 6080 is the culprit. But don't give up on 6080s. My 2nd favorite tube for my Crack is a 6080 (Bendix with graphite plates).


----------



## palmfish

Oh don't worry, I'm not giving up on them. I bought the CBS Hytron 6AS7G simply because I like the way it looks. As I understand it, with the Speedball upgrade (which I intend to get), it almost makes tube rolling a waste of time (I think you are the one who said this - paraphrasing of course). I'm thinking that the differences between tubes are, as a rule, highly overstated anyways. Subjective vs. objective and all that...
   
  FWIW, the tube that came with my kit is a "5919 JAN CAHG Chatham 6080." A mil spec tube if I'm not mistaken - it certainly looks beefy inside.
   
  This is simply a fun road to walk down and I'm enjoying the new toys and knowledge. It's already been a great experience - with more to come.


----------



## DefQon

Didn't know Dayton Audio made "audio" caps. 
   
  Where are you guys bypassing the 2.2uf film caps on the PS section, that's about the only thing I haven't done to mine. (Or pic)


----------



## amcananey

Bottlehead even uses Dayton caps in some of its kits.

The primary cap to bypass is the cap that is furthest to the left, at the top of the amp (when looking at the underside, with the power supply at the top, the way all the Bottlehead pics are oriented). It's the one that sticks out to the left, rather than straight up. You can bypass the other 220uf electrolytics, too, but the last one is most relevant for these purposes.

Best regards,
Adam


----------



## amcananey

This is another one of my favorite Crack upgrades...especially when using the Harrison attenuators!

Best regards,
Adam


----------



## brunk

Quote: 





amcananey said:


> This is another one of my favorite Crack upgrades...especially when using the Harrison attenuators!
> 
> Best regards,
> Adam


 
  yeah i think im going to get some of those and maybe make a decent power cord myself with a right angle plug.


----------



## amcananey

Meh. This does it for me: http://www.amazon.com/SF-Cable-Universal-Right-IEC320/dp/B006VZI4QA/ref=sr_1_1?ie=UTF8&qid=1376286618&sr=8-1&keywords=right+angle+power+cord


----------



## ffivaz

Quote: 





palmfish said:


> Oh don't worry, I'm not giving up on them. I bought the CBS Hytron 6AS7G simply because I like the way it looks. As I understand it, with the Speedball upgrade (which I intend to get), it almost makes tube rolling a waste of time (I think you are the one who said this - paraphrasing of course). I'm thinking that the differences between tubes are, as a rule, highly overstated anyways. Subjective vs. objective and all that...
> 
> FWIW, the tube that came with my kit is a "5919 JAN CAHG Chatham 6080." A mil spec tube if I'm not mistaken - it certainly looks beefy inside.
> 
> This is simply a fun road to walk down and I'm enjoying the new toys and knowledge. It's already been a great experience - with more to come.


 
   

 You could also try to let the tubes "burn in" (settle ?). I had some tubes in a phono stage that needed about 30 hours to become quiet. BTW, is it a hiss (ssss or shhh) or a hum (60 hz or something background sound often changing with volume) ?


----------



## palmfish

It's a 60 Hz "mains hum." Unaffected by volume. Definitely sounds like a ground issue to me.


----------



## amcananey

For anyone who has a Crack kit on the way (or who has one, but hasn't built it yet), I highly recommend following the LED advice on this page: http://www.bottlehead.com/smf/index.php/topic,4687.msg44445.html#msg44445. It will save you a lot of frustration. Note that you do NOT solder the center pin right away. As he says, just push the leads through and then wait until the manual tells you to solder that pin. Best regards, Adam P.S. When I post from work, formatting gets all screwed up. I can't embed links and text becomes a continuous block without any line breaks...


----------



## Beefy

Quote: 





amcananey said:


> For anyone who has a Crack kit on the way (or who has one, but hasn't built it yet), I highly recommend following the LED advice on this page: http://www.bottlehead.com/smf/index.php/topic,4687.msg44445.html#msg44445. It will save you a lot of frustration. Note that you do NOT solder the center pin right away. As he says, just push the leads through and then wait until the manual tells you to solder that pin.


 
   
  I would also recommend that you pre-install the mouting standoffs for the Speedball before soldering anything on that socket, rather than just routing it differently.


----------



## Doc B.

Whoa, I lay low for a couple days and come back to find 113 new posts on this thread! Palmfish, are you stacking the Crack on top of another piece of gear? Magnetic coupling with another component's power transformer can be the cause of steady 60Hz. 

All this mod stuff is cool. My suggestion to first timers however is to ignore what the guys who have built a bunch of gear say about must have this cap or that pot, and just build your kit with stock parts. It will make any troubleshootinng a lot easier and you can always change it out later. Also, if you are going to spend $4K on tubes for Crack, go Mainline instead. Just sayin'.


----------



## amcananey

As usual, Doc says it best. Definitely build stock first.


----------



## Beefy

I have to disagree. For some potential upgrades, pre-planning is absolutely essential.


----------



## Armaegis

Quote: 





beefy said:


> I would also recommend that you pre-install the mouting standoffs for the Speedball before soldering anything on that socket, rather than just routing it differently.


 
   
  +1
   
  The first time I installed a speedball, I had a bugger of a time getting it into place. The second time through I laid out all the parts that could be done ahead of time and even the resistors that would be eventually cut out I left them "hanging" with extra lead length to make them easier to remove. This made the upgrade incredibly easier.


----------



## amcananey

beefy said:


> I have to disagree. For some potential upgrades, pre-planning is absolutely essential.



 
 I don't think Doc meant you shouldn't do any pre-planning, such as installing fly leads or cable ties ahead of time. But you should stick to the basic circuit and stock parts. Otherwise troubleshooting is much more difficult, both for you, and for the Bottlehead team. Get the Crack working first, then you can experiment. And offhand, I can't think of any upgrades that can't be implemented after the fact. There may be a little more effort involved, but the differences aren't huge. In general, all you're doing is clipping out one component and soldering in another. The problems that you will have with "upgrades" are largely mounting and space considerations. Frankly, you will have these problems one way or the other, and I'm not convinced they are that much easier to solve in advance, vs. tackling them after the Crack is already built in stock form and fully functional. Lastly, building it stock first lets you make an informed decision on whether you want to make a change, and if so, what you want to change. All this talk of mods and "upgrades" tends to obscure one basic fact: the Crack and/or Crack + Speedball sound excellent in stock form. Wonderful sounds and tone, with low noise. The tweaks discussed above don't make the Crack 50% better. Or 20% better or even 5-10% better. We are talking about really subtle tweaks to an already outstanding amp. The modding is fun, and I enjoy customizing my amp, but the sonic benefits are frankly modest. The stock Crack parts are well-chosen to provide good value AND good performance, not just because they are the cheapest parts that won't make the kit explode. After building the Crack in stock form, you may well find that you don't have any complaints and don't want to mess with a good thing. And.........I just realized that this is all going to appear without formatting as a giant, unintelligible block of text that nobody will want to wade through.....


----------



## amcananey

Actually, to really put a fine point on it...I have generally found that the greatest impediment to future upgrades was not anything in the stock Crack from a component or layout perspective...it was the upgrades I had installed earlier, which then made accessing the circuit or finding space and suitable mounting options difficult! Sometimes I'm my own worst enemy...


----------



## J-Pak

Does the top plate need to be modified to accommodate an RK27 pot?
   
  I have a suspicion that this will not fit inside


----------



## mellowbob

Quote: 





j-pak said:


> Does the top plate need to be modified to accommodate an RK27 pot?
> 
> I have a suspicion that this will not fit inside


 
  That thing's a beaut! Where can I get one? I'd mount that upside down and drive it with a gear just to show it off!


----------



## GaryPham

Still hoping someone out there with first hand experience with Denons D2/D5k/D7k can tell me how it matches with the BH crack.  I've been hearing mixed opinions, with some people saying it should be fine and some saying that its a terrible match, but so far it's all been theoretical.  Was hoping I can get direct opinions before I go and sell my current dac/SS amp combo and purchase a new DAC for the BH crack.


----------



## amcananey

I'll try to remember to try it with my D7000 tonight.


----------



## brunk

Quote: 





amcananey said:


> Meh. This does it for me: http://www.amazon.com/SF-Cable-Universal-Right-IEC320/dp/B006VZI4QA/ref=sr_1_1?ie=UTF8&qid=1376286618&sr=8-1&keywords=right+angle+power+cord


 
  Now where's the fun in that?


----------



## amcananey

That, in and of itself, is not fun. But it does free me up to do stuff that IS fun!


----------



## brunk

Quote: 





amcananey said:


> That, in and of itself, is not fun. But it does free me up to do stuff that IS fun!


 
  Lol i guess it depends how you look at it. For $6 though it is mighty tempting since it does seem like building a power cord is quite time consuming anyways.


----------



## Armaegis

Years ago I tried the Crack with a D2000 but do not recall being particularly wowed by the combination.


----------



## GaryPham

armaegis said:


> Years ago I tried the Crack with a D2000 but do not recall being particularly wowed by the combination.




Does the combination make it sound even worse than if were unamped? I know that some headphones actually sound worse when amped, my amperiors specifically sounded way cleaner without an external amp.


----------



## mellowbob

Quote: 





mellowbob said:


> That thing's a beaut! Where can I get one? I'd mount that upside down and drive it with a gear just to show it off!


 

 Found it. It's an ALPS RK50114A0001. The price for it is just a bit out of my range.


----------



## Armaegis

Quote: 





garypham said:


> Does the combination make it sound even worse than if were unamped? I know that some headphones actually sound worse when amped, my amperiors specifically sounded way cleaner without an external amp.


 
   
  I'm running off years old memory here... it was definitely better out of my iBasso D10. I don't remember how unamped compared to the Crack.


----------



## brunk

Quote: 





mellowbob said:


> Found it. It's an ALPS RK50114A0001. The price for it is just a bit out of my range.


 
  *Rubs eyes* 
   
  Am I seeing that price right?!


----------



## Nic Rhodes

I have had a look at my 'stock capacitors' for amp building that I have in (so don't have to buy any new ones which is my plan atm). On the film caps I have 47mF 630v which are large (x8, >2" long, 1.5" diameter) and 100mF 630v (x2, 3" long, 2" diameter) which are truely immence with large bolt fixing (M10?!!). Both are are few years old now and are made I think by Solen if memory serves? Marked PPE MKP FC 47mF 630v 5% made in France and MKP FC 47mF 630v 5% made in France. Are these still competitive (97 era I think) and does anyone have any advice re installing these biggies? Other options are 100mF Blackgates.


----------



## brunk

Quote: 





nic rhodes said:


> I have had a look at my 'stock capacitors' for amp building that I have in (so don't have to buy any new ones which is my plan atm). On the film caps I have 47mF 630v which are large (x8, >2" long, 1.5" diameter) and 100mF 630v (x2, 3" long, 2" diameter) which are truely immence with large bolt fixing (M10?!!). Both are are few years old now and are made I think by Solen if memory serves? Marked PPE MKP FC 47mF 630v 5% made in France and MKP FC 47mF 630v 5% made in France. Are these still competitive (97 era I think) and does anyone have any advice re installing these biggies? Other options are 100mF Blackgates.


 
  I'm not one to offer the final advice on these, but i did read on the bottlehead forums somewhere that using something like those 630v caps may possibly have a negative effect because they wont discharge as fast as the 250v can. Hopefully someone more experienced than me can chime in here.


----------



## brunk

I've got a question for you experienced Crack builders. Will it be a problem fitting 18ga. wire as the PSU hot in the terminals with the other stuff? Thanks in advance.


----------



## ben_r_

Quote: 





brunk said:


> I've got a question for you experienced Crack builders. Will it be a problem fitting 18ga. wire as the PSU hot in the terminals with the other stuff? Thanks in advance.


 

 Nope, I used some 18AWG. Just a bit stiffer.


----------



## brunk

Quote: 





ben_r_ said:


> Nope, I used some 18AWG. Just a bit stiffer.


 
  Awesome, thank you sir


----------



## amcananey

brunk said:


> I'm not one to offer the final advice on these, but i did read on the bottlehead forums somewhere that using something like those 630v caps may possibly have a negative effect because they wont discharge as fast as the 250v can. Hopefully someone more experienced than me can chime in here.



 
 Nope. You can always use caps that are rated higher than stock (and some claim that higher-rated caps sound better, anyway). The only problem is getting them to fit. Here are some pics showing how I did it (using Clarity Cap ESA caps): http://www.head-fi.org/g/a/735260/bottlehead-crack-speedball/ And here are some pics of my Bottlehead Quickie, using even bigger caps: http://www.bottlehead.com/smf/index.php/topic,4375.0.html In both cases, I've made additional mods to the Crack and Quickie since the pictures were taken.


----------



## brunk

Quote: 





amcananey said:


> Nope. You can always use caps that are rated higher than stock (and some claim that higher-rated caps sound better, anyway). The only problem is getting them to fit. Here are some pics showing how I did it (using Clarity Cap ESA caps): http://www.head-fi.org/g/a/735260/bottlehead-crack-speedball/And here are some pics of my Bottlehead Quickie, using even bigger caps: http://www.bottlehead.com/smf/index.php/topic,4375.0.html In both cases, I've made additional mods to the Crack and Quickie since the pictures were taken.


 
  Where did you get those adjustable feet, I want something like that instead of isolation cones or rubber pads so i can have some ventilation underneath.


----------



## J-Pak

Quote: 





mellowbob said:


> Found it. It's an ALPS RK50114A0001. The price for it is just a bit out of my range.


 

 That might be the part number for he 2 channel version, the one pictured is a quad pot, maybe 2x the price 
	

	
	
		
		

		
		
	


	




 Anyway I no longer have that pot or any of the parts that go for that amp; simply too insanely complex for me.


----------



## amcananey

brunk said:


> Where did you get those adjustable feet, I want something like that instead of isolation cones or rubber pads so i can have some ventilation underneath.



 
 LOL...it was a bit of a Frankenstein construction. Here is what I did: 1. Drilled fairly short (maybe 3/8" deep?) holes in the four corners using a slightly wider drill bit. 2. Within each of those holes, drilled a considerably deeper (1.5 - 2") hole using a much thinner drill bit. 3. Screwed a threaded "sleeve" into each of the wide/shallow holes. I picked this up at my local hardware store. When you buy it, they can tell you what drill bit to use. You use a hex wrench to screw the sleeve into the hole. It had metal fins/tabs on the outside the bite into the wood and hold it in place. The inside is threaded to accept machine screws. 4. Screwed a long (3-4") flat-headed machine screw into each of the threaded sleeves. 5. Used some epoxy to glue the "feet" onto the heads of the machine screws. While it is a bit tricky, be sure to flip the chassis over before the epoxy sets, so that the "feet" are resting level on a table as the epoxy sets. Otherwise the feet will be off-kilter and look funky. Once that is done, you can adjust the height of the Crack, and of the feet, simply by turning the feet/screws within the metal sleeves. The long/narrow holes provide clearance for the machine screws within the wood as you lower the Crack case.


----------



## amcananey

Oh, I forgot to add...the feet are just some sort of round rubber feet with a raised lip or ring around the outside. They are actually meant to be used with the flat part against the relevant object (e.g., a chair or table) and the lip/ring resting on the ground. You are supposed to attach them using a screw from the bottom (with the head of the screw inside the center of the lip/ring. I flipped them around, and put the flat part on the bottom, and used the indentation in the center of the lip/ring to glue the machine screw heads. This is sort of what they looked like: http://www.electronicplus.com/images/products/B-322-C.jpg The only difference is that mine didn't have a hole in the middle, but you get the general idea.


----------



## brunk

Cool, thanks.


----------



## brunk

Well i found some pretty nice feet that will allow for a little air flow and prevent vibrations. Cost like $5 and got them in black
http://www.vibrationmounts.com/Store.asp?Page=Products6.htm


----------



## skeptic

Quote: 





beefy said:


> I would also recommend that you pre-install the mouting standoffs for the Speedball before soldering anything on that socket, rather than just routing it differently.


 
   
  +2 for this guidance!  Way back when, I somehow managed to damage one of my a-socket led's when I was trying to place the standoffs for my speedball.  Had a devil of a time figuring out what the problem was, and when I finally concluded that I needed a new led, I had to fully remove the speedball boards to access the socket and replace it.  If you do decide to wait to put in the standoffs, make sure you are gentle when you go about it.
   
  More generally, it's really fun to see all the new participants and activity in this thread.  The recent discussion of various possible mods reminded me that I never got around to dropping in the 2.2uf axon bypass cap I had ordered for the psu (more than 2 years ago!) or grounding the two empty terminals on the headphone jack.  Made both changes yesterday, and although it may just be in my head, I think my crack sounds just a tad better and smoother than it did before the addition of the bypass cap.


----------



## palmfish

doc b. said:


> Palmfish, are you stacking the Crack on top of another piece of gear? Magnetic coupling with another component's power transformer can be the cause of steady 60Hz'.




Nah, that was just a glamor shot Doc. 

Ive moved my Crack all over the house and the hum is the same everywhere.


----------



## brunk

Quote: 





palmfish said:


> Nah, that was just a glamor shot Doc.
> 
> 
> 
> ...


 
  You might want to see a doctor about that


----------



## Zashoomin

Hi guys I am building a crack and just finished and for some reason everytime I turn on the amp I blow a fuse even though all the resistances are correct.  I have also had a couple people double check my work and it seems as though everything is right.  Anyone have any suggestions?  here is a picture of it currently.  Also I am now using ceramic 500ma fuses even though that doesn't make any difference. I think. 
   

   

   

   
  Thanks in advance.  For some reason this one is causing me trouble.  All the other ones I have build have been just fine.


----------



## Beefy

I have always had terrible problems with ceramic fuses blowing way faster than normal fuses, even in slow-blow form. Strongly recommend against them.


----------



## Zashoomin

Quote: 





beefy said:


> I have always had terrible problems with ceramic fuses blowing way faster than normal fuses, even in slow-blow form. Strongly recommend against them.


 
   
  Alright what fuse would you recommend?


----------



## calipilot227

Check your caps and the small black resistors. I had one oriented incorrectly and blew about 5 fuses until I found the problem. Then, head to Radioshack and pick up some 1a 250v slow-blow fuses.


----------



## DefQon

Checking for the resistor resistance mean's nothing when trouble shooting amps. Check that you've actually soldered components with marked polarity the right way, no cold solder joints and things are soldered to the right place.


----------



## Nic Rhodes

Thanks for the large cap images, much food for thought there. I will be making some new plinths at Christmas and capacitor management seems to be the driving issue


----------



## mellowbob

Got my tubes today! Plugged em in and finished my voltage checks.
I am fortunate to not have any balance problems or noise problems. It's dead silent even at max volume!
I am very impressed by the sound. It's definitely a "smoother" sound compared to my iCan and E9k. 
It's like comparing a 10 yr old single malt scotch to an 18 yr old one. Harsh vs mellow smooth.
So far so good. Going to spend a week or so listening stock then I'm adding the speedball. 
I don't know if there's a break in period for tubes but I notice the volume is starting to increase so I have to turn down the knob a little.
Very cool kit. Great job to the guys at Bottlehead.


----------



## Zashoomin

Thanks guys for all the help and after another 3 hours of troubleshooting I still can't find the reason why so I am going to blame it on the fuses at this point.  See how it works out when I get new fuses tomorrow.


----------



## ffivaz

Check this out : http://www.bottlehead.com/smf/index.php?topic=3074.0
   
  Your rectifier diodes could be toasted...
   
  Quote: 





zashoomin said:


> Hi guys I am building a crack and just finished and for some reason everytime I turn on the amp I blow a fuse even though all the resistances are correct.  I have also had a couple people double check my work and it seems as though everything is right.  Anyone have any suggestions?  here is a picture of it currently.  Also I am now using ceramic 500ma fuses even though that doesn't make any difference. I think.
> 
> Thanks in advance.  For some reason this one is causing me trouble.  All the other ones I have build have been just fine.


----------



## Beefy

Quote: 





zashoomin said:


> Alright what fuse would you recommend?


 
   
  Well, the one that came in your kit, for starters. But any bog standard glass fuse from the hardware store with the correct rating.
   
  Obviously if it stills blows you have bigger problems.


----------



## DefQon

Do a diode check. If no reading on your DMM under the diode test, it means its open/shorted.


----------



## amcananey

Just a reminder to everyone building a kit: if you have any problems, I highly recommend posting in the Bottlehead forum, rather than here. While Doc checks in here regularly, the Bottlehead team monitors the Bottlehead forum more frequently, and there are many seasoned Bottlehead customers who also provide helpful advice. You will get more timely, and comprehensive, service by posting on the Bottlehead forum than you will by posting here. Best regards, Adam


----------



## brunk

Quote: 





amcananey said:


> Just a reminder to everyone building a kit: if you have any problems, I highly recommend posting in the Bottlehead forum, rather than here. While Doc checks in here regularly, the Bottlehead team monitors the Bottlehead forum more frequently, and there are many seasoned Bottlehead customers who also provide helpful advice. You will get more timely, and comprehensive, service by posting on the Bottlehead forum than you will by posting here. Best regards, Adam


 
  +1 will keep that in mind, thanks.


----------



## Zashoomin

Thank you all for all your help and as it turns out it was just the fuses.  Everything is working and all the voltages are correct.  I am now in the process of installing speedball.  Again thank you for all the help.


----------



## brunk

Quote: 





zashoomin said:


> Thank you all for all your help and as it turns out it was just the fuses.  Everything is working and all the voltages are correct.  I am now in the process of installing speedball.  Again thank you for all the help.


 
  Whew that's a relief i bet! Keep us posted on the upgrade


----------



## Zashoomin

Quote: 





brunk said:


> Whew that's a relief i bet! Keep us posted on the upgrade


 
  Photos will be accompanying the upgrade.   Almost done too just need to make sure everything is working as it should be.


----------



## brunk

Quote: 





zashoomin said:


> Photos will be accompanying the upgrade.   Almost done too just need to make sure everything is working as it should be.


 
  Sweet! I'm still munching...


----------



## Aeolus Kratos

Hi guys,

 I'm pretty new to this fantastic Crack community.
   
  Last night, I've experimented a problem with my Crack again 

 I turned my Crack on and let the tubes warm up for about 10 minutes, then I plugged my HD650 into it. But when the music was playing for just a few minutes, there was a big 'pop' sound coming from the left channel ( it was like there is an 'explosion' in the left channel ). Then it was back to silent again and nothing happened after that.

 My Crack killed my $5 headphone once when I tested it with bad tubes back then. Now I'm really afraid that what if would kill my HD650 too, I don't want to take risks again, especially with a $400 headphone 
   
  I'm using the Chatham 2399 ( Tung-sol 5998 ) as my power tube and the Tungsram E80CC as my input tube in my Speedballed Crack.

 Any advice?

 Best regards,
 Kratos.


----------



## amcananey

garypham said:


> Still hoping someone out there with first hand experience with Denons D2/D5k/D7k can tell me how it matches with the BH crack.  I've been hearing mixed opinions, with some people saying it should be fine and some saying that its a terrible match, but so far it's all been theoretical.  Was hoping I can get direct opinions before I go and sell my current dac/SS amp combo and purchase a new DAC for the BH crack.




I tested my D7000s with my Crack tonight. Perhaps unsurprisingly, it is not a combo I would recommend. I don't know if I heard bass roll-off, which is one of the theoretical disadvantages of using low impedance headphones with an OTL amp, but the bass was definitely mushy and ill-defined. And the lack of power was striking - the Crack still had plenty of power to get to high volume, but I found myself turning the volume pot up to levels I would never go with my HD800s. Lastly, the D7000s generally seemed to lack resolution. 

Now bear in mind that there are mods you can make to the Crack to make it slightly more amenable to low impedance headphones, but ultimately I doubt this will ever be an ideal pairing. FWIW, I own, and have owned, a LOT of amps. My reference amps for the D7000s are the HiFiMAN EF-6 (which I actually liked better with the D7000 than with my HE-6s...go figure) and Audio-Gd Roc SA (an amazing, and unfortunately no longer available amp). The Violectric V200 would be my 3rd choice, just behind the first two by a minuscule hair's breadth. 

But with that said, the Crack is the best amp I've ever heard for Sennheiser and high-impedance Beyers, full stop. If you want an all-purpose amp, the Crack isn't it. It is a specialized tool that does what it is designed to do exceptionally well. If you want an all-rounder, there is the S.E.X. or Mainline. 

Last note: while the D7000s sound better amped, and with the amps mentioned above in particular, I have always found that they do pretty well with small portable amps, too. You don't need to blow big bucks on an amp for the D7000.

Best regards,
Adam


----------



## amcananey

Probably a bad tube. I'm guessing the output tube, just because the same thing happened to me with a bad 6080. Try putting the stock tubes back in again and see if you still have problems.


----------



## ben_r_

Quote: 





garypham said:


> Still hoping someone out there with first hand experience with Denons D2/D5k/D7k can tell me how it matches with the BH crack.  I've been hearing mixed opinions, with some people saying it should be fine and some saying that its a terrible match, but so far it's all been theoretical.  Was hoping I can get direct opinions before I go and sell my current dac/SS amp combo and purchase a new DAC for the BH crack.


 

 I have tested my D5000's with it and wouldnt recommend it. Its pretty well known that the Crack is for high impedance headphones only. I bought the Crack specifically just for my HD-650's and will someday only use it with any other high impedance cans I get. I have solid state amps for the lower impedance headphones. I personally like the NuForce HDP or ASUS Essence One with my D5000s.


----------



## amcananey

I just need to give a shout out to the D2000, D5000 and D7000s. Three unique sets of cans, each excellent in their own way. They never got quite the respect they deserved, but I still think Denon was monumentally stupid to discontinue them. I've neglected my D7000s in favor of my HD800s, HE-6s and K1000s lately. This was a good excuse to put my D7000s through their paces. I'm falling in love all over again. I should have been in bed a while ago, but I can't stop listening...


----------



## GaryPham

Thanks guys, I really appreciate you guys for testing out the Denons on the BH crack for me.  Looks like I'll be keeping my 11.32 around as well then, as I really do love both the Denon D2000s and the HD650s.  Was hoping to limit myself down to just solid state or OTL, but looks like I'll be keeping one of each =p/


----------



## Nic Rhodes

I have heard of several 5998 tubes doing this.


----------



## Cryok95

Quote: 





aeolus kratos said:


> Hi guys,
> 
> I'm pretty new to this fantastic Crack community.
> 
> ...


 

 It could be a cold solder joint...


----------



## Aeolus Kratos

Quote: 





amcananey said:


> Probably a bad tube. I'm guessing the output tube, just because the same thing happened to me with a bad 6080. Try putting the stock tubes back in again and see if you still have problems.


 
  Hi Adam,
   
  Thanks, I'll put my other tubes back again.
  Quote: 





nic rhodes said:


> I have heard of several 5998 tubes doing this.


 
  
  Quote: 





cryok95 said:


> It could be a cold solder joint...


 
  Just to clarify, When the music was playing last night, I got popping, then the music was back to be good and nothing wrong had happened again since that. Just a popping showed up once when I heard the Crack, after that it no longer happened.


----------



## ffivaz

Quote: 





aeolus kratos said:


> Hi Adam,
> 
> Thanks, I'll put my other tubes back again.
> 
> Just to clarify, When the music was playing last night, I got popping, then the music was back to be good and nothing wrong had happened again since that. Just a popping showed up once when I heard the Crack, after that it no longer happened.


 
   
  I have a RCA 6AS7G doing the same thing. It's popping during warm-up (the first 10 minutes, about 5 or 6 pops), but afterwards quite quiet. I don't think it can hurt your headphones...


----------



## amcananey

Kratos,

If the music is playing, then you should be OK. Your tube probably just needs some time to settle in. I had understood that you didn't hear any music after there was the loud pop. I think you can leave the 5998 / E80CC in.

Regards,
Adam


----------



## Nic Rhodes

These were the caps I was looking at!!


----------



## Aeolus Kratos

Quote: 





ffivaz said:


> I have a RCA 6AS7G doing the same thing. It's popping during warm-up (the first 10 minutes, about 5 or 6 pops), but afterwards quite quiet. I don't think it can hurt your headphones...


 
   
  Quote: 





amcananey said:


> Kratos,
> 
> If the music is playing, then you should be OK. Your tube probably just needs some time to settle in. I had understood that you didn't hear any music after there was the loud pop. I think you can leave the 5998 / E80CC in.
> 
> ...


 

 Thank you guys! I'm much relieved now. My Crack is back to dead silent, I feel that it's even more quite than it was before the pop happened 
	

	
	
		
		

		
			




   
  Cheers! And happy listening!
  Kratos.


----------



## GaryPham

Just picked up a Sylvania 12BH7 black plate and an RCA 6as7g black plate.  Now just waiting for my BH with speedball kit to arrive =p.  Is anyone running this combination of tubes?  impressions?


----------



## dsound

I love the 12bh7/ RCA 6AS7G combo.  Warm and dynamic with a nice sparkle on the top-end.  It's actually one of the few instances I've found where I like the 12bh7 
	

	
	
		
		

		
		
	


	




.
   
   
  Quote: 





garypham said:


> Just picked up a Sylvania 12BH7 black plate and an RCA 6as7g black plate.  Now just waiting for my BH with speedball kit to arrive =p.  Is anyone running this combination of tubes?  impressions?


----------



## Zashoomin

Pictures as promised.  This is something I built for another head-fi member.  
   

   

   

   

   
  Also how hot do the your guy's tubes run?


----------



## GaryPham

that looks gorgeous


----------



## brunk

Is that a custom power cord? Can you provide more info on that? Thanks  Excellent job by the way!
  Quote: 





zashoomin said:


> Pictures as promised.  This is something I build for another head-fi member.


----------



## Zashoomin

Quote: 





brunk said:


> Is that a custom power cord? Can you provide more info on that? Thanks  Excellent job by the way!


 
   
  Sure so It has got a right angle IEC connector and on the other side is a Wattgate connector.  So inside the paracord is round litz braid of 4 wires that connect to the positive and negative leads.  The bare wire wrapped around the paracord is just a twisted pair that is connected to the ground.  All the wires are 20awg silver plated copper and there is pair of them per lead so 6 wires total effectively making it about 17awg per lead.  
   
  Quote: 





garypham said:


> that looks gorgeous


 
  Thank you


----------



## amcananey

Crazy deal on Bottlehead S.E.X. kits going on right now: http://www.bottlehead.com/smf/index.php/topic,4702.0/topicseen.html Hurry! Offer expires at noon tomorrow...


----------



## Doc B.

Eileen heard from our winder that the power transformers for the outstanding Crack orders should be shipping out to us tomorrow. So we should be back to packing and shipping Crack kits early next week. Thanks for hanging in with us while we get caught up with the huge number of orders.


----------



## brunk

Quote: 





amcananey said:


> Crazy deal on Bottlehead S.E.X. kits going on right now: http://www.bottlehead.com/smf/index.php/topic,4702.0/topicseen.html Hurry! Offer expires at noon tomorrow...


 
  So tempting but i already have a great integrated amplifier plus the crack on the way, just not a SET amp


----------



## brunk

Quote: 





downhomeupstate said:


> Got the caps from Parts Express - nothing fancy - Dayton Audio, but Doc (and I think Paul B) mentioned on the BH Crack forum thread that any film cap would do. And the price was right: less than $27 ea.
> 
> Pot was from DigiKey - their part no. KKA5031S28-ND  I read somewhere on the BH forum that some folks found that using a 50K pot was quieter than the stock pot at 100K. I guess I'll find out. Doc B likes the PEC pots for the money.
> 
> ...


 
  I just want to note that i had received the soft-annealed solid silver wire and teflon tubing from Handmade Electronics. I highly recommend NOT getting the 24ga. silver wire. It is so soft and thin that its a royal PITA fishing it through the tubing even a couple of feet without it kinking every 1/2in. Spend the few extra $ and get the 22 or 20ga. it's not worth the effort at all.


----------



## sjeffrey

Quote: 





doc b. said:


> Eileen heard from our winder that the power transformers for the outstanding Crack orders should be shipping out to us tomorrow. So we should be back to packing and shipping Crack kits early next week. Thanks for hanging in with us while we get caught up with the huge number of orders.


 

 Are the orders from after the July deal far behind?  I placed my order on the 5th.  Just wondering if there were a lot of placed after the free upgrade deal expired.
   
  Thanks


----------



## Doc B.

We ordered plenty of transformers to cover current and future orders. Orders have indeed continued to be quite brisk since the special. It's been a very busy summer, for which we are most thankful to those of you who have ordered and those who will be ordering.


----------



## rosgr63

Quote: 





aeolus kratos said:


> Thank you guys! I'm much relieved now. My Crack is back to dead silent, I feel that it's even more quite than it was before the pop happened
> 
> 
> 
> ...


 
  The 5998's have been known to pop and damage headphones with some amps and I am not referring to Bottlehead amps.
  Be careful it could happen again at random.
   
  The 6AS7G are usually safer.


----------



## brunk

Quote: 





rosgr63 said:


> The 5998's have been known to pop and damage headphones with some amps and I am not referring to Bottlehead amps.
> Be careful it could happen again at random.
> 
> The 6AS7G are usually safer.


 
  I bought a couple sets of $2 headphones for when i first try my crack and various tubes. Thanks for the heads up. I dont want my T1 or HD-800s having a blowout!


----------



## ben_r_

This is the first I have heard of the 5998's causing literal blowouts. How often does this occur? Is it only used ones or has it happened to NOS or something like a new Chatham?


----------



## Doc B.

With all due respect, it would be unfortunate if this turned into an internet legend of 5998s regularly blowing up headphones all over the planet. This stuff is DIY, and we do it for the reward of great sound at a reasonable cost and a sense of accomplishment. Sometimes it is easier to blame some particular item for all of our problems based upon one or two occurrences rather than looking at the probabilities of the cause of it happening. One can screw up their equipment lots of ways - hot plugging, bad solder joints, miswires and yeah, occasionally, flakey tubes. It's just part of the learning experience. As my old bud John Tucker used to say when we were building (and occasionally blowing up) circuits - "no balls, no fly medal".


----------



## brunk

Quote: 





doc b. said:


> With all due respect, it would be unfortunate if this turned into an internet legend of 5998s regularly blowing up headphones all over the planet. This stuff is DIY, and we do it for the reward of great sound at a reasonable cost and a sense of accomplishment. Sometimes it is easier to blame some particular item for all of our problems based upon one or two occurrences rather than looking at the probabilities of the cause of it happening. One can screw up their equipment lots of ways - hot plugging, bad solder joints, miswires and yeah, occasionally, flakey tubes. It's just part of the learning experience. As my old bud John Tucker used to say when we were building (and occasionally blowing up) circuits - "no balls, no fly medal".


 
  Well said Doc!


----------



## ben_r_

Quote: 





doc b. said:


> With all due respect, it would be unfortunate if this turned into an internet legend of 5998s regularly blowing up headphones all over the planet. This stuff is DIY, and we do it for the reward of great sound at a reasonable cost and a sense of accomplishment. Sometimes it is easier to blame some particular item for all of our problems based upon one or two occurrences rather than looking at the probabilities of the cause of it happening. One can screw up their equipment lots of ways - hot plugging, bad solder joints, miswires and yeah, occasionally, flakey tubes. It's just part of the learning experience. As my old bud John Tucker used to say when we were building (and occasionally blowing up) circuits - "no balls, no fly medal".


 

 All well and good when your blowing up 20 cent resistors, but $400+ headphones and $100+ tubes is a different story to which would never want to try and justify with "just part of the learning experience".


----------



## Doc B.

Well, we seem to agree that you have to decide for yourself what the reasonable cost to learn something is. I won't upset you by stopping to figure out how much stuff I have blown up over a lifetime of DIY audio


----------



## amcananey

I really don't think that is what Doc was saying. As I read it, his point was: don't blame the 5998 and claim that it is prone to blowing up headphones. There may have been one or two 5998s that were bad, but that could just as easily have been due to some sort of problem with the relevant amp. Or it could have been those specific 5998s that were bad, but it isn't as though there are no bad 6AS7Gs or 6080s or whatever. Absent some sort of statistical evidence from a large sample size over time using a variety of amps, it seems irresponsible to claim, based on anecdotal evidence, that 5998s are particularly dangerous and should be avoided. Best regards, Adam


----------



## amcananey

And to further clarify: yes, Doc was making the point that you can't make an omelette without breaking a few eggs, but I consider that a separate point from the question of whether 5998s are fault-prone.


----------



## Doc B.

Quote: 





amcananey said:


> Absent some sort of statistical evidence from a large sample size over time..., it seems irresponsible to claim, based on anecdotal evidence, that ... are particularly dangerous and should be avoided.


 
  Don't tell CNN or FOX that.


----------



## kozmos

that's why i bought Sennheisers, if i blow a driver i can always buy a new one and replace it


----------



## GrindingThud

This is not really a 5998 specific issue. Any tube at any time can fail in an arc-over mode. Most of the time, your ears ring and the driver is fine. In an OTL amp using CCS, the current gets limited and the event is pretty much a non event. For OTL with just a resistor in cathode, the pop can be much louder. I'm only aware of a couple on the forum that have stated they've lost a driver....I believe this is a very rare occurrence. I've had a number of arc-over events and none have damaged my HD558. Specifically, I've had 2399, TS7236 (box plates), and 5998A do this....all high transconductance tubes. It's almost always used tubes from unknown sellers (cheap ebay) and none of mine were NOS failures. Also, they all did it within a few minutes of warmup. My standard procedure now is to treat questionable tubes with caution and let them warm up for a few minutes without my headphones plugged in to be sure they are good. 



ben_r_ said:


> This is the first I have heard of the 5998's causing literal blowouts. How often does this occur? Is it only used ones or has it happened to NOS or something like a new Chatham?


----------



## brunk

Quote: 





grindingthud said:


> It's almost always used tubes from unknown sellers (cheap ebay) and none of mine were NOS failures. Also, they all did it within a few minutes of warmup. My standard procedure now is to treat questionable tubes with caution and let them warm up for a few minutes without my headphones plugged in to be sure they are good.


 
  Sage advice indeed. I have had similar experiences with ebay tubes, and a couple of scares with my speakers.


----------



## Armaegis

Quote: 





> Originally Posted by *Doc B.* /img/forum/go_quote.gif
> 
> "no balls, no fly medal".


 
   
  fly medal?
   
  (the reference is lost on me)


----------



## skeptic

Being the generous and helpful guy that I am, I will save you all from your dangerous 5998's by taking them off your hands for $10/each


----------



## Loquah

Quote: 





armaegis said:


> fly medal?
> 
> (the reference is lost on me)


 
   
  It sounds to me like an air force reference or similar, but I don't know for sure. I figure it's something along the lines of "no guts, no glory"... maybe "no broken drivers, no awesome amplifier"?
   
  Only kidding, I actually think Doc's comments seem reasonable given that we're in the DIY world here and it just makes me think that I'll plug in my cheap, old and worn-out AKGs to test any new tubes before firing them up with my HD650s or T1s.


----------



## Armaegis

I just want to mention as a counterpoint, I've smoked more headphones with DIY solid state amps than I have tubes.


----------



## Aeolus Kratos

Quote: 





rosgr63 said:


> The 5998's have been known to pop and damage headphones with some amps and I am not referring to Bottlehead amps.
> Be careful it could happen again at random.
> 
> The 6AS7G are usually safer.


 














 . Looks like I have to go for a GEC 6AS7G Brown base, right? 
	

	
	
		
		

		
		
	


	



  Quote: 





amcananey said:


> I really don't think that is what Doc was saying. As I read it, his point was: don't blame the 5998 and claim that it is prone to blowing up headphones. There may have been one or two 5998s that were bad, but that could just as easily have been due to some sort of problem with the relevant amp. Or it could have been those specific 5998s that were bad, but it isn't as though there are no bad 6AS7Gs or 6080s or whatever. Absent some sort of statistical evidence from a large sample size over time using a variety of amps, it seems irresponsible to claim, based on anecdotal evidence, that 5998s are particularly dangerous and should be avoided. Best regards, Adam


 
  You had some very good point, Adam.
  Quote: 





kozmos said:


> that's why i bought Sennheisers, if i blow a driver i can always buy a new one and replace it


 
  Hi kozmos,
   
  Does Sennheiser sell their headphone drivers separately? And where I can buy them?
   
  Thanks.
  Quote: 





skeptic said:


> Being the generous and helpful guy that I am, I will save you all from your dangerous 5998's by taking them off your hands for $10/each


 
  LOL
   
  It is my pleasure to take all of your very dangerous 5998's off you for $20/each.
  Now I guess I'm twice as generous and helpful as you 
	

	
	
		
		

		
		
	


	



   
  Quote: 





ben_r_ said:


> This is the first I have heard of the 5998's causing literal blowouts. How often does this occur? Is it only used ones or has it happened to NOS or something like a new Chatham?


 
   


> I don't know about you guys, but my Crack actually KILLED my Panasonic HTF-600 about a month ago. But it was not due to the 5998's as I still have not had a 5998 back then. It was the bad stock 6080 tube.


   
  I only had this popping happen once two days ago, but it has not happened again since. I'm using NOS Chatham 2399 by the way.
   
  Kratos.


----------



## thunkerdo

Stupid question.  Just ordered the crack, but am hearing the end of this forum where people are talking about amps busting headphones.  Are you guys modding the crack?  Or do I not have to worry with the stock crack?


----------



## brunk

Quote: 





thunkerdo said:


> Stupid question.  Just ordered the crack, but am hearing the end of this forum where people are talking about amps busting headphones.  Are you guys modding the crack?  Or do I not have to worry with the stock crack?


 
  This is a rare occurence and typically only happens if youre not paying attention to the manual. Had to put that in perspective. All is well.


----------



## Cryok95

Quote: 





thunkerdo said:


> Stupid question.  Just ordered the crack, but am hearing the end of this forum where people are talking about amps busting headphones.  Are you guys modding the crack?  Or do I not have to worry with the stock crack?


 
   
  I had no problems with the crack whatsoever.


----------



## thunkerdo

Great.  Thanks, guys.  Was a little worried for a sec.  Now if I could only decide on an under $200 DAC, which I know nothing about.


----------



## amcananey

I have generally found that the entire Audio-Gd lineup provides excellent value for money. While their stand-alone DACs cost more than $300, they have combined DAC, headphone amps and pre-amp units that are value-priced, yet still offer a ton of features and performance. Take a look at their $299 NFB-11.32 (http://www.audio-gd.com/Pro/Headphoneamp/NFB11.32/NFB11.32EN.htm) based on the ES9018 chip, and their $235 NFB-15.32 (http://www.audio-gd.com/Pro/Headphoneamp/NFB15.32/NFB15.32EN.htm), which uses dual WM8741 chips.


----------



## amcananey

Whoops, I apologize. I just saw that you said under $200, not under $300. Are you using USB, or do you need optical and/or coaxial inputs? If you only need USB, then just go for an ODAC. I wouldn't really waste too much time thinking about it. If you need optical and/or coaxial, then consider a used DAC.


----------



## thunkerdo

Quote: 





amcananey said:


> Whoops, I apologize. I just saw that you said under $200, not under $300. Are you using USB, or do you need optical and/or coaxial inputs? If you only need USB, then just go for an ODAC. I wouldn't really waste too much time thinking about it. If you need optical and/or coaxial, then consider a used DAC.


 
   
  This was extremely helpful.  I'm new to all this.  I just need USB.  I think I'll go with standalone ODAC from JDS Labs.  Oh, would I need the RCA output?  Or just the standard output.


----------



## amcananey

thunkerdo said:


> This was extremely helpful.  I'm new to all this.  I just need USB.  I think I'll go with standalone ODAC from JDS Labs.  Oh, would I need the RCA output?  Or just the standard output.



 
 I would go for the RCA output version. Do you NEED it? Maybe not, but it gives you a lot more cable flexibility going forward, and is generally just more convenient.


----------



## GaryPham

Quote: 





amcananey said:


> I would go for the RCA output version. Do you NEED it? Maybe not, but it gives you a lot more cable flexibility going forward, and is generally just more convenient.


 
   
  Apologies if this question has been answered before, but is there a disadvantage to using an RCA to 3.5mm interconnect vs regular rca to rca?  I'm also looking at picking up an ODAC as well and wondering if its worth it to spring extra for the RCA outputs version.  I already have an RCA to 3.5mm interconnect, but willing to spend extra for the ODAC with RCA if its actually better.


----------



## Armaegis

The rca-rca connection is physically/mechanically stronger and more secure against fuzziness/static if you move the unit around (which shouldn't be an issue as it's serving purely as dac).


----------



## palmfish

RCA to RCA might be more reliable if you'll be frequently plugging and unplugging the cord, but sound-wise, there shouldnt be an audible difference.

EDIT: I see Armaegis hit enter before me...


----------



## amcananey

It's been argued that RCA-RCA has lower potential for crosstalk. Whether that pans out in real life, I don't know. Again, I see it as more of a convenience question, plus the opportunity to use any number of interconnects going foward.


----------



## thunkerdo

So, as far as tools needed for this build I have
   
  1) Greenlee 1917A Wire Stripper/Cutters, 26-16 AWG
  2) Xcelite CN255V Curved Nose Plier 
  3) Xcelite MS54V Semi-flush Oval Head Cutter
   
  What soldering station have you used?  Can I buy the cheapest one on amazon?
   
  I also see this is helpful:
  http://www.head-fi.org/t/476650/crack-bottlehead-otl/1965#post_9611502


----------



## Armaegis

A small bottle of liquid/paste flux is also useful. And a box of little bandaids for the inevitable small burns, lol.


----------



## palmfish

thunkerdo said:


> So, as far as tools needed for this build I have
> 
> 1) Greenlee 1917A Wire Stripper/Cutters, 26-16 AWG
> 2) Xcelite CN255V Curved Nose Plier
> 3) Xcelite MS54V Semi-flush Oval Head Cutter




Oh no! Dont spend that much. Here's what I used...

http://www.amazon.com/gp/product/B000NPR2LW/ref=oh_details_o02_s00_i00?ie=UTF8&psc=1

http://www.amazon.com/gp/product/B000JNLUN4/ref=oh_details_o03_s01_i02?ie=UTF8&psc=1

http://www.amazon.com/Mini-Diagonal-Cutting-Pliers-Memory/dp/B000VKUP1I/ref=sr_1_1?s=hi&ie=UTF8&qid=1376671478&sr=1-1&keywords=Diagonal+cut+pliers


----------



## brunk

Quote: 





thunkerdo said:


> So, as far as tools needed for this build I have
> 
> 1) Greenlee 1917A Wire Stripper/Cutters, 26-16 AWG
> 2) Xcelite CN255V Curved Nose Plier
> ...


 
  Per Crack Manual:
   
*Tools and additional materials you will need:*
   

 eye protection
 slotted tip screwdriver
 needlenose pliers
 wire cutters
 wire stripper for 12ga. and smaller wire
 soldering iron, 40W is fine. An inexpensive solder station is much, much better
 volt-ohm meter - we suggest a 'pocket DMM' - use this for sorting out hard to read resistors
 a good light source
 Sharpie or other marking pen for terminal ID
 a soft towel or placemat to rest the amps on while working on the underside—the sticky bubble 
 wrap supplied with your kit can also work well as a cushion for your project.
   
*other tools that are nice to have:*
   

 magnifying glass for parts identification
 desoldering tool or desoldering braid
 A set of small sockets and a socket wrench for tightening the mounting hardware
 A “third hand” tool can be useful for situations where you need support the parts you are working 
 on while keeping both hands free to solder
   
*Solder -*
  we recommend standard 60/40 or 63/37 tin/lead solder as the easiest to work with. 2% silver solder is OK, but stay away from 4% silver solder. It does not flow well. If you are using an adjustable solder station you will want to set the temperature to about 650-700 degrees.
   
*Paint—*
  you may wish to paint the power transformer bell end. We suggest a light scuff sanding with 
  220 grit sandpaper and cleaning of the surfaces with a good degreaser like formula 409 or Fantastik 
  before spraying.
   
*Materials for finishing the wood bases - *
  220 grit sandpaper, wood glue, masking tape, stain, and 
  a finish. Analine dyes are a great way to get a clear finish that really shows off the wood grain. The 
  newer  polymer  finishes  such  as  Varathane  Diamond  are  easy  to  use  and  easy  to  clean  up  with 
  water. Spar varnish gives a nice glossy finish.


----------



## Doc B.

JT was avionics tech in the Navy, and our old mentor John Buddha Camille was an F4 Phantom pilot in Viet Nam, who had shot down 4 MIGs. So the phrase is probaby from their experiences. As an interesting tie in to this talk about building electronic stuff - Buddha would have been an ace with 5 kills, but twice he had missles fail to fire during a dogfight. In both cases it was found that there were bad solder joints in their electronics.

Regarding headphones being damaged when connected to Crack kits - there are thousands of Crack kits in the field, and I'm pretty sure this is the first case we've heard of noise from the output tube damaging headphones.


----------



## palmfish

Or all three of these for less than $10 total...

http://www.harborfreight.com/4-3-4-quarter-inch-bent-needle-nose-pliers-40698.html

http://www.harborfreight.com/7-inch-wire-stripper-with-cutter-98410.html

http://www.harborfreight.com/4-1-2-half-inch-diagonal-cutters-40695.html


----------



## thunkerdo

So, this soldering station is fine?  It's $20 on amazon.
   
  Also, do I really need a digital multimeter?  Or will this suffice:
  http://www.csgnetwork.com/resistcolcalc.html
   
  Also, thank you guys for the help.  I really cannot wait for my crack to ship.


----------



## amcananey

1. That soldering station is variable power, which is not the same thing as temperature controlled. You really want a temperature controlled soldering station, believe me. It doesn't need to be digital (and in fact, most digital displays don't really do anything all that useful). I highly recommend the Weller WES51. It's not the cheapest, not the most expensive, but it is very common, which means replacement tips in various sizes are fairly common and not that expensive. It is also well-made and very comfortable to use. I would definitely recommend spending a bit extra on your soldering station. You will use it for a lot of things going forward, not just this project. 2. You need a digital multimeter. You're not just checking the values of the resistors you install, you also need to check resistances and voltages at various places in the amp after completing your build. There are very cheap multimeters available. I've had $5 ones that were suprisingly accurate. But they also have significant limitations, including short, non-replaceable test leads, no auto-ranging function, and unergonomic leads that can make it more difficult to safely test voltages. I bought this multimeter and I've been absolutely stunned at how good it is for the price. http://www.amazon.com/gp/product/B0050LVFS0/ref=oh_details_o00_s00_i02?ie=UTF8&psc=1 3. As for shear cutters, I have these and love them. http://www.amazon.com/gp/product/B000IBU1JQ/ref=oh_details_o00_s00_i01?ie=UTF8&psc=1 I bought these after a host of others that were all crappy for one reason or another. These just work, and work well. Best regards, Adam


----------



## amcananey

Oh, and I also recommend getting some solder braid (also called desolder wick). This is very useful if you make a mistake. Since it wasn't immediately clear to me how you use it, here is what you do: (1) pull about 6" of braid out of the dispenser. Pick a spot that is 2-3" from the tip of the braid. Place this spot on the solder joint you want to desolder. Place the tip of the soldering iron against the solder braid, on the opposite side of the solder braid from the solder joint you want to remove. Let your iron tip heat the braid and the solder joint for 5-10 seconds, then slowly pull on the solder braid from the side closest to the spool. Keep your iron tip stationary, directly over the solder joint you're removing. The solder braid will get pulled between your iron tip and the solder joint. The tip will keep the solder melted, and it will get absorbed by the solder braid. You need to keep the solder braid moving, because it quickly saturates with the melted solder. If you still have extra solder on the joint you want to remove, then trim the piece of the solder braid with the solder in it, and repeat the process. In my experience, when doing point-to-point wiring, solder braid works better than a solder sucker or desoldering pump. Here is a link to what you need: http://www.amazon.com/dp/B008O9VX6O/ref=biss_dp_t_asn For $3, you are better off having it ready when you need it. Best regards, Adam


----------



## Zashoomin

The variable temperature definately helps. If you make a mistake I find that a higher temperature make it a lot easier to desolder stuff. Also if you have different kinds of solder you will need different temperatures and what not so it will help. Yes get some solder wick and strippers, solder, wood glue, diagonal cutters, definately a multimeter, and needle nose pliers. Its a lot of stuff upfront but if you get quality tools they will last you a lifetime and maybe even longer so its all an investment.


----------



## thunkerdo

Thanks guys!  I just finished buying everything.  I don't think I've been this excited in a while.  I bought the JDS Labs ODAC to go with it (not sure if it was the right choice or not) and it shipped almost right away, so that was great.  Headphones should be here Monday.  Gear by Wednesday.  Not sure on the Crack.
   
  So hoping that the Bottlehead Crack isn't backlogged.  I'm already ready to put this together


----------



## amcananey

You will have to wait a bit, but fortunately is sounds as thought the wait won't be unreasonable. I'm curious: what soldering iron did you get, and what headphones will you be using?


----------



## thunkerdo

I purchased the HD 650's, as I like a warmer/fuller sound and heard that these offer that.  These are also the ones I've always wanted, but never have been able to afford until recently.  I also bought the soldering iron you recommended (Weller WES51) as well as those wire cutters.


----------



## amcananey

Well, I have a hard time arguing with your choices!  If you are going to go with HD650s, I think the Crack is the best amp for them I've ever heard. Enjoy, you will have a great setup when you're done!


----------



## calipilot227

HD650, Crack... just add a Schiit Modi DAC and you'll have my rig 
	

	
	
		
		

		
			




   
  In case you were still looking at DACs, the Modi is an excellent value at $99.


----------



## sjeffrey

Or bifrost and you'll have my to be setup


----------



## Aeolus Kratos

sjeffrey said:


> Or bifrost and you'll have my to be setup


 
  I'm using the Modi with my Crack and HD650. Have you ever heard the Modi? If so, how would you compare it to your Bifrost? I'm planning to upgrade the DAC to the Bifrost, but I'm not sure if the differences are worth the premium price or not 
   
  Thanks,
  Kratos.


----------



## W0lfd0g

Hi Kratos
   
  Did you decide on getting a GEC 6AS7G brown base?  One just finished for well under $200.00 - Was this you?
   
  Cheers


----------



## Nic Rhodes

whoever it was they just pipped me to it!


----------



## W0lfd0g

Check out eBay international - One ending in the land of Oz in about 18 hours currently @ $120.00 US (76 GBP)


----------



## lextek

Time for some morning Crack and coffee. Best way to start the day.


----------



## W0lfd0g

Up at the Crack of Dawn, hey lextek!


----------



## Loquah

Quote: 





w0lfd0g said:


> Check out eBay international - One ending in the land of Oz in about 18 hours currently @ $120.00 US (76 GBP)


 
   
  Sssshhhhh!! Don't tell people - I'm stalking that one right now!!


----------



## brunk

Quote: 





lextek said:


> Time for some morning Crack and coffee. Best way to start the day.


----------



## amcananey

aeolus kratos said:


> I'm using the Modi with my Crack and HD650. Have you ever heard the Modi? If so, how would you compare it to your Bifrost? I'm planning to upgrade the DAC to the Bifrost, but I'm not sure if the differences are worth the premium price or not
> 
> Thanks,
> Kratos.




Kratos,

I know people will disagree, but in my experience all DACs sound the same once you (a) get over the $100 price point, and (b) equalize for strength of output signal. I have a $1,000 DAC, I have several $300-500 DACs, and I have two $100 DACs. In a blind test, I don't think I could tell the difference between any of them, there are a lot of things you could spend money on rather than a DAC and get bigger improvements in sound. YMMV

Best regards,
Adam


----------



## W0lfd0g

I think you need to have a yard sale, Adam.  Make sure you invite me!


----------



## ben_r_

Quote: 





amcananey said:


> Kratos,
> 
> I know people will disagree, but in my experience all DACs sound the same once you (a) get over the $100 price point, and (b) equalize for strength of output signal. I have a $1,000 DAC, I have several $300-500 DACs, and I have two $100 DACs. In a blind test, I don't think I could tell the difference between any of them, there are a lot of things you could spend money on rather than a DAC and get bigger improvements in sound. YMMV
> 
> ...


 
   
  I have found the same to be true here as well.


----------



## Aeolus Kratos

Quote: 





amcananey said:


> Kratos,
> 
> I know people will disagree, but in my experience all DACs sound the same once you (a) get over the $100 price point, and (b) equalize for strength of output signal. I have a $1,000 DAC, I have several $300-500 DACs, and I have two $100 DACs. In a blind test, I don't think I could tell the difference between any of them, there are a lot of things you could spend money on rather than a DAC and get bigger improvements in sound. YMMV
> 
> ...


 

 Hi Adam,
   
  Really? Actually this is the first time I've heard someone saying that there is NO difference in sound quality when you change DACs, my experience is different, I'm not as fortunate as you, I can hear the differences between DACs, I guess you can save bunch of dollars thanks to that 
	

	
	
		
		

		
		
	


	



   
  Which equipment should I spend money on to get big improvements in your opinion? 
	

	
	
		
		

		
		
	


	



   
  Thanks for your reply,
   
  Best regards,
  Kratos.


----------



## Aeolus Kratos

Quote: 





w0lfd0g said:


> Hi Kratos
> 
> Did you decide on getting a GEC 6AS7G brown base?  One just finished for well under $200.00 - Was this you?
> 
> Cheers


 

 Hi WOlfdOg,
   
  No, after receiving some recommendations from Adam here and in Bottlehead forum, which I guess you read also, I decided not to go for the premium tubes, and I'm gonna save pennies for the coming BH DAC 
	

	
	
		
		

		
		
	


	



   
  Best,
  Kratos.
   
  P/S: I'm really jealous with your huge tube inventory by the way


----------



## brunk

Quote: 





aeolus kratos said:


> Hi Adam,
> 
> Really? Actually this is the first time I've heard someone saying that there is NO difference in sound quality when you change DACs, my experience is different, I'm not as fortunate as you, I can hear the differences between DACs, I guess you can save bunch of dollars thanks to that
> 
> ...


 
  Buy the best headphone you can afford, first and foremost.


----------



## uzi

Quote: 





amcananey said:


> I know people will disagree, but in my experience all DACs sound the same once you (a) get over the $100 price point, and (b) equalize for strength of output signal. I have a $1,000 DAC, I have several $300-500 DACs, and I have two $100 DACs. In a blind test, I don't think I could tell the difference between any of them, there are a lot of things you could spend money on rather than a DAC and get bigger improvements in sound. YMMV


 
  I'll disagree as I do hear differences between DACs.  For example, I can definitely easily hear a difference between the HRT MS II and HRT MSII+.... but I could barely hear a difference between the ODAC and the HRT MSII.  The difference is easier to hear with certain setups than others.


----------



## W0lfd0g

aeolus kratos said:


> Hi WOlfdOg,
> 
> No, after receiving some recommendations from Adam here and in Bottlehead forum, which I guess you read also, I decided not to go for the premium tubes, and I'm gonna save pennies for the coming BH DAC
> 
> ...




I can definitely appreciate where Adam is coming from.

That said, everyone has a differing system and ears. I am looking at refining something I love to bits and don't want to alter dramatically. Tube rolling is a fun way to do this.

There is room for the subjective in this hobby. And for differences of opinion.

Cheers


----------



## Loquah

Quote: 





w0lfd0g said:


> Check out eBay international - One ending in the land of Oz in about 18 hours currently @ $120.00 US (76 GBP)


 
   
  It's finished and on it's way to my Crack! 
	

	
	
		
		

		
		
	


	



   
  My first significant tube purchase (i.e. >$50). I hope it will be a nice upgrade over my existing GE 6AS7GA which sounds brilliant with Genalex Gold ECC82 and driving my T1s.


----------



## W0lfd0g

Congrats!


----------



## Aeolus Kratos

Quote: 





brunk said:


> Buy the best headphone you can afford, first and foremost.


 
  Hi Brunk,
   
  How would you think about using the TH-900 with the Crack? I've heard the TH-900 once and I totally loved it. But I'm not sure if they are good when paired with the Crack or not 
   
  Cheers.
  Quote: 





loquah said:


> It's finished and on it's way to my Crack!
> 
> 
> 
> ...


 
   
  Nice! And don't forget to leave some impressions on how the sound is when you get the GEC 
	

	
	
		
		

		
		
	


	



   
  Happy listening.


----------



## brunk

Quote: 





aeolus kratos said:


> Hi Brunk,
> 
> How would you think about using the TH-900 with the Crack? I've heard the TH-900 once and I totally loved it. But I'm not sure if they are good when paired with the Crack or not
> 
> Cheers.


 
  I'm still awaiting my crack, but it will surely not be a good match because they are a low impedance headphone. That said, if you want to DIY an excellent amp for them, "The Wire" is a good place to start. That may be my next DIY amp project for the TH-900s, but i still need a good phono-pre and switch box hehe. If you want a finished amp that has superb specs for its price ($360), the Yulong A100 is an excellent choice. Plus I don't know about you, but i am a sucker for VU meters!


----------



## kozmos

kratos, you can buy parts from Sennheiser.


----------



## amcananey

brunk said:


> Buy the best headphone you can afford, first and foremost.




Headphones are the first, second and third-best thing you can spend money on. They make the biggest difference in sound quality, by far. Everything else basically amounts to tweaking.

Best regards,
Adam


----------



## Armaegis

Some would make the argument that a few refreshing drinks would also have a profound effect on sound quality.


----------



## Beefy

armaegis said:


> Some would make the argument that a few refreshing drinks would also have a profound effect on sound quality.




Helps make the forum easier to read as well.......


----------



## palmfish

I had a productive weekend! I finally got around to staining the base and I also plugged in my new tubes...


----------



## Aeolus Kratos

Quote: 





kozmos said:


> kratos, you can buy parts from Sennheiser.


 
  Hi Kozmos,
   
  Thanks. I guess I'll have to order a pair of HD650's drivers for back up before they discontinue to produce the HD650's 
	

	
	
		
		

		
			




  Quote: 





palmfish said:


> I had a productive weekend! I finally got around to staining the base and I also plugged in my new tubes...


 
  Congrats on your fantastic work! What tubes are you using for your Crack?


----------



## palmfish

Thank you! That's a CBS 6AS7G and CBS 5814a


----------



## Zashoomin

Quote: 





palmfish said:


> I had a productive weekend! I finally got around to staining the base and I also plugged in my new tubes...


 
  Very nicely done.  Any other mods that I can't see on the underside?


----------



## Armaegis

Quote: 





beefy said:


> Helps make the forum easier to read as well.......


 
   
  Staying out of the iem and high end forums has helped with that considerably...


----------



## brunk

Quote: 





armaegis said:


> Staying out of the iem and high end forums has helped with that considerably...


 
  Hehe no kidding


----------



## brunk

Quote: 





palmfish said:


> I had a productive weekend! I finally got around to staining the base and I also plugged in my new tubes...
> 
> 
> Spoiler: Warning%3A%20Spoiler!


 
  Looks very nice!
  Quote: 





zashoomin said:


> Very nicely done.  Any other mods that I can't see on the underside?


 
  I'm interested in this as well


----------



## palmfish

Quote: 





zashoomin said:


> Very nicely done.  Any other mods that I can't see on the underside?


 
   
  Quote: 





brunk said:


> Looks very nice!
> I'm interested in this as well


 
   
  Nope, no mods. No upgraded parts - the kit comes with high quality parts already so I didn't feel the need to change anything.


----------



## Doc B.

Power transformers have arrived and we have begun the next round of packing Crack kits. Kits should begin shipping out tomorrow with many, many more to follow over the next week or so.


----------



## thunkerdo

Do you guys recommend a pointed or flat solder tip for the Crack (without the speedball)?  Also, I heard someone on here recommend this tip tinner.  Is this something I should look into?  Or is just tinning the tip with my solder good enough?  I have the WES51 solder.


----------



## ben_r_

Quote: 





thunkerdo said:


> Do you guys recommend a pointed or flat solder tip for the Crack (without the speedball)?  Also, I heard someone on here recommend this tip tinner.  Is this something I should look into?  Or is just tinning the tip with my solder good enough?  I have the WES51 solder.


 

 Chisel tip is what I recommend and just tinning the tip with solder should be good enough.


----------



## Zashoomin

Quote: 





thunkerdo said:


> Do you guys recommend a pointed or flat solder tip for the Crack (without the speedball)?  Also, I heard someone on here recommend this tip tinner.  Is this something I should look into?  Or is just tinning the tip with my solder good enough?  I have the WES51 solder.


 
  I personally like the pointed just because i can surface solder better but I think flat is going to be easier for soldering point to point.  Also you can just tin your own tips with solder...you don't need to spend $10 on something like that.


----------



## palmfish

Another vote for chisel tip here. And solder is all you need.


----------



## GrindingThud

Chisel tip.... Save the $ for good solder.
I like this solder.....a lot: http://www.ebay.com/itm/High-Tech-Rosin-Core-Silver-Bearing-Solder-1-5-Oz-2160630-/400539389561?pt=LH_DefaultDomain_0&hash=item5d42020e79


----------



## brunk

Quote: 





doc b. said:


> Power transformers have arrived and we have begun the next round of packing Crack kits. Kits should begin shipping out tomorrow with many, many more to follow over the next week or so.


 
  Woo hoo, my kit has shipped and will be here on the 26th! Thanks Doc


----------



## Zashoomin

Quote: 





brunk said:


> Woo hoo, my kit has shipped and will be here on the 26th! Thanks Doc


 
  I ordered the reduction phono preamp can't wait to start building it.  Hope it ships soon.  
   
  Quote: 





grindingthud said:


> Chisel tip.... Save the $ for good solder.
> I like this solder.....a lot: http://www.ebay.com/itm/High-Tech-Rosin-Core-Silver-Bearing-Solder-1-5-Oz-2160630-/400539389561?pt=LH_DefaultDomain_0&hash=item5d42020e79


 
  I will be honest that stuff isn't horrible but Cardas stuff is a lot better.  Best solder I have used to date.  Its a bit expensive but I think its worth it.  You can buy small amounts here to try it out.


----------



## palmfish

Solder doesnt matter, as long as its easy to work with. I use Kester 60/40.


----------



## GrindingThud

Yes, that Cardas looks extremely nice....I'll need to pick some up next time I get low.. I find .032 a little thick, do they make .022? Easy to work with is 1st priority. 



zashoomin said:


> I ordered the reduction phono preamp can't wait to start building it.  Hope it ships soon.
> 
> I will be honest that stuff isn't horrible but Cardas stuff is a lot better.  Best solder I have used to date.  Its a bit expensive but I think its worth it.  You can buy small amounts here to try it out.


----------



## Zashoomin

Quote: 





grindingthud said:


> Yes, that Cardas looks extremely nice....I'll need to pick some up next time I get low.. I find .032 a little thick, do they make .022? Easy to work with is 1st priority.


 
  Nope Cardas only makes 2 different kinds and both are the same thickness the only difference is one has lead and the other does not.


----------



## brunk

Quote: 





grindingthud said:


> Yes, that Cardas looks extremely nice....I'll need to pick some up next time I get low.. I find .032 a little thick, do they make .022? Easy to work with is 1st priority.


 
http://www.cmlsupply.com/kester-44-020-solder-1lb.html has what youre looking for. Plus, you get a free gadget with your purchase


----------



## Loquah

brunk said:


> http://www.cmlsupply.com/kester-44-020-solder-1lb.html has what youre looking for. Plus, you get a free gadget with your purchase




And free cancer according to their disclaimers at the bottom :-o


----------



## brunk

Quote: 





loquah said:


> And free cancer according to their disclaimers at the bottom :-o


 
  LMAO, that's a stupid California thing...amongst several hehe.


----------



## caracara08

Quote: 





zashoomin said:


> I ordered the reduction phono preamp can't wait to start building it.  Hope it ships soon.
> 
> I will be honest that stuff isn't horrible but Cardas stuff is a lot better.  Best solder I have used to date.  Its a bit expensive but I think its worth it.  You can buy small amounts here to try it out.


 
   
  I've created a monster.  Soon youre going to own every BH product available!  Cant wait to try out the Crack you built me!


----------



## amcananey

I started out using lead-free solder, with and without silver. Leaded solder was a revelation, and I found I much prefer 63/37 over 60/40. FWIW, I like Kester 245 better than Kester 44. The difference is that Kester 245 has a no-clean flux core, which is better if you do any PCB soldering.


----------



## Zashoomin

Quote: 





caracara08 said:


> I've created a monster.  Soon youre going to own every BH product available!  Cant wait to try out the Crack you built me!


 
  Ya since yours I am on my 4th one haha.  A couple cracks, sex, and reduction.  I hope you like it.


----------



## Zashoomin

Quote: 





amcananey said:


> I started out using lead-free solder, with and without silver. Leaded solder was a revelation, and I found I much prefer 63/37 over 60/40. FWIW, I like Kester 245 better than Kester 44. The difference is that Kester 245 has a no-clean flux core, which is better if you do any PCB soldering.


 
  Honestly lead-free solder is pretty horrible.  solder with lead is so much more easy to work with. 
   
  Edit:  Let me clarify lead free is a lot harder to work with but not atrocious.  if you have something against lead than you won't have much of a choice.  Also its honestly not any more unhealthy to use leaded solder as the fumes that come off are boiling rosin not lead fumes.  Just make sure to wash your hands after.


----------



## ffivaz

Quote: 





thunkerdo said:


> Do you guys recommend a pointed or flat solder tip for the Crack (without the speedball)?  Also, I heard someone on here recommend this tip tinner.  Is this something I should look into?  Or is just tinning the tip with my solder good enough?  I have the WES51 solder.


 
   
  I used a flat one, with the simple method demonstrated by Tyll Hertsens on his nice video about making the BH Crack. And it worked fine.
   
  I used solder with lead. It is easier and is not environnementaly dangerous until you throw your kit away, in decades


----------



## Beefy

Quote: 





amcananey said:


> I started out using lead-free solder, with and without silver. Leaded solder was a revelation, and I found I much prefer 63/37 over 60/40. FWIW, I like Kester 245 better than Kester 44. The difference is that Kester 245 has a no-clean flux core, which is better if you do any PCB soldering.


 
   
  Yes, 63/37 (eutectic) is a must for electronics. It makes the 'freezing' point of the solder much more consistent, otherwise the solder can give a poor connection if anything is physically moved during cooling.
   
  Wikipedia rocks this topic: http://en.wikipedia.org/wiki/Solder


----------



## Doc B.

Thanks for the enthusiasm, and thanks for patience with delivery! It may not seem it, but we are a pretty dinky outfit. Our margins basically allow only for part time help and at any given time we only have two people packing and shipping. Though lately we have had all hands on deck a few times to get this latest round of Crack shipments moving.

Nothing is pre-packaged, every *&^*&%^&! screw and washer gets counted out and bagged by a very patient, meticulous and over qualified Bottlehead employee. With all of the different kits we have these days we have to move through the packing in groups whenever possible. So they tend to ship out in batches, on a rotation that is largely influnced by "did those vendors ship those parts we ordered yet?". When a spike in orders like we had last month on Crack kits happens, it makes this process particularly interesting, kinda like you are juggling three tennis balls and a guy walks up with a big blue bowling ball and motions that he is going to throw it to you.

As for soldering, yes, 1/16" chisel tip, 63/37 leaded solder, and a sponge for tip cleaning are the way we do it. A decent soldering station is paramount. Hakko, Weller etc. are fine. We use a Hakko at work, I have an Ersa at home (really nice but $$$ and hard to find parts).


----------



## calipilot227

Crack build approaching final form...

   
  Still need to install the Speedball upgrade, and the base needs some clearcoat. But I've been having too much fun listening


----------



## amcananey

What paint did you use on the base?
   
  Too bad the Bottlehead flair isn't available in silver!
   
  Best regards,
  Adam


----------



## calipilot227

Just some standard high-gloss black, sanded between coats (600 grit), and rubbed with steel wool following the final coat. I'll have to check the specific brand, I may have thrown out the can already.
   
  And because we never get tired of glowing tubes,


----------



## brunk

Quote: 





calipilot227 said:


> Just some standard high-gloss black, sanded between coats (600 grit), and rubbed with steel wool following the final coat. I'll have to check the specific brand, I may have thrown out the can already.
> 
> And because we never get tired of glowing tubes,


 
  Oh my...are you trying to seduce me? 
	

	
	
		
		

		
		
	


	



   
  Seriously though, well done!


----------



## Doc B.

Interesting about the silver flair- 
I made a key fob a few years ago that is a piece of mpingo with some elephant hide connecting the key ring to the fob. The wood has a Bottlehead badge attached. Over the years of riding around in a pocket the gold color has worn off the badge, revealing the bare metal underneath. So if one wanted a silver badge I think running it over some 400 grit wet or dry taped to a flat surface might do the trick. Have not tried it myself, so don't blame me if it turns out funky...


----------



## brunk

Quote: 





doc b. said:


> Interesting about the silver flair-
> I made a key fob a few years ago that is a piece of mpingo with some elephant hide connecting the key ring to the fob. The wood has a Bottlehead badge attached. Over the years of riding around in a pocket the gold color has worn off the badge, revealing the bare metal underneath. So if one wanted a silver badge I think running it over some 400 grit wet or dry taped to a flat surface might do the trick. Have not tried it myself, so don't blame me if it turns out funky...


 
  I was thinking about how to make it silver colored myself. I'd like to request a silver option at checkout Doc


----------



## Doc B.

OK, but I'll just charge an extra buck and include a piece of sandpaper.


----------



## brunk

Quote: 





doc b. said:


> OK, but I'll just charge an extra buck and include a piece of sandpaper.


 
  Lol, DIY to the very last detail


----------



## kozmos

I got my mundorf mkp caps today, how do i locate positive and negative ?


----------



## amcananey

Unless the manufacturer indicates how you can/should identify which end is which, don't worry about it. Film caps don't really have positive and negative leads... It's not like electrolytics where if you install them the wrong way it goes "BOOM!".


----------



## amcananey

brunk said:


> Lol, DIY to the very last detail



 
 I find this idea extremely amusing...I would love to see Doc actually implement it! :-D


----------



## Armaegis

Quote: 





amcananey said:


> Unless the manufacturer indicates how you can/should identify which end is which, don't worry about it. Film caps don't really have positive and negative leads... It's not like electrolytics where if you install them the wrong way it goes "BOOM!".


 
   
  I wonder if we have a gallery anywhere of DIY gone wrong?


----------



## MrEleventy

DIW (Doing It Wrong)?


----------



## dsound

Quote: 





armaegis said:


> I wonder if we have a gallery anywhere of DIY gone wrong?


 

 The build thread for my newest amp could be such a gallery.. sigh.  Time to get out the DMM.


----------



## caracara08

any slightly more budget friendly recommendations for tube rolling?  I went ot the BH forum and looked up a few but theyre all expensive.  I received the tubes from BH but the 6080 (I think it is) has something loose inside it and its rattling.  
   
  Thank you.


----------



## FlySweep

> riginally Posted by *caracara08* /img/forum/go_quote.gif
> 
> any slightly more budget friendly recommendations for tube rolling?  I went ot the BH forum and looked up a few but theyre all expensive.  I received the tubes from BH but the 6080 (I think it is) has something loose inside it and its rattling.
> 
> Thank you.


 
   
  Get a Tung Sol 5998.  Sorry, it's not cheap @ the current going rate ($85).. but, IMO, it's most definitely worth it... and it should be a one time purchase that will *most likely* last you the life of your Crack.  For an input tube, get the Tesla ECC802S.  It's a phenomenal tube that's got the special reputation of being a near copy (in sound and build) of the famed, exquisite sounding.. and stupid expensive, Telefunken ECC802S... but for much _much_ cheaper.  I have it and can confirm that it, indeed, sounds _wonderful_.  Certainly one of the best sounding tubes I've rolled into the Crack.  If I could have just two or three (input) tubes for the Crack, it would definitely be one of them.


----------



## caracara08

perfect. the 5998 is a bit more than I want to spend but I sent them an email.   Will also look into the Tesla.  Thanks a bunch.


----------



## amcananey

FWIW, the fact that something (probably bits of glass) is rattling around in your 6080 isn't unusual or detrimental unless you are somehow getting microphonics. Also, my personal opinion, after having tried lots of tubes in my Crack, including tubes that cost hundreds of dollars, is that (a) if you have installed the Speedball, then tube rolling makes an almost imperceptible difference and isn't worth the cost and hassle, and (b) if you haven't installed the Speedball, then you are far better off spending your money on the Speedball than on tubes. Best regards, Adam


----------



## caracara08

Thanks Adam, it does have the speedball.  Yeah, I'll give the stock tube a try tonight.  It does look like a piece of glass.  I should also go through my old tubes... i might have something good in there that would work.  Ive had the WA2, CSP2+, Lyr, WA6 and a couple others.  Collected tubes along the way.  Just got it delivered today.  Its actually the one that zashoomin posted pictures of a couple pages ago! He also made me 2 sets of RCA cables and a power cable.  When BH comes out with their DAC, I will be sending it to him to build me as well.  
   
  I know that the Crack is beginner status but with 3 kids under 5 years old and no space to melt metal onto metal, I decided not to try and have someone make it for me.


----------



## EraserXIV

Difference between the 5998 and an RCA 6AS7G is definitely not subtle when I roll them through, even with speedball. Now if the difference is better, that's something you need to decide on your own.


----------



## GaryPham

How long did it take for you guys to receive your BH cracks from the day it gets shipped out?  I'm heading on vacation in about 2 weeks and am a bit worried about delivery date since my kit hasn't been shipped out yet....(hopefully not too long since I'm from California..)


----------



## Doc B.

A brief update - we got almost all of the orders from the second day of the special (7/13) shipped today. The rest of the kits ordered during the special should be shipping tomorrow, and we will be getting into packing and shipping of orders received after the special early next week. Wish I had had time to take a picture of the towers of kit boxes stacked up in the lobby, but the UPS driver arrived while we were putting the last labels on.


----------



## Zashoomin

Quote: 





caracara08 said:


> When BH comes out with their DAC, I will be sending it to him to build me as well.


 
  haha I have yet to hear about this but sounds like fun 
	

	
	
		
		

		
		
	


	




.  Surface soldering those stupid chips though is such a pain.  Can't wait to work on it though.


----------



## Doc B.

There will be no surface mount soldering to be done in our kit, it will come with the surface mount parts already installed.


----------



## Beefy

Quote: 





eraserxiv said:


> Difference between the 5998 and an RCA 6AS7G is definitely not subtle when I roll them through, even with speedball. Now if the difference is better, that's something you need to decide on your own.


 
   
  Properly volume matched, I assume? The 5998 has substantially higher gain.


----------



## brunk

Hey Beefy,
   
  I'm going to be building my Crack and SB soon and was hoping i can get some advice on ease of installation.
   
  I understand it's a good idea to put in the LEDs before the wires, installing the SB standoffs before wiring, and installing fly leads for my film caps. Is there anything else recommended? Thanks.


----------



## amcananey

If you are installing a different volume pot, check whether you need to widen the hole before starting your build.

When attaching anything to terminal 14U, try to keep it as clean as possible, because you will need every fraction of a millimeter you can get there, since a ton of stuff runs through there.

Best regards,
Adam


----------



## brunk

Quote: 





amcananey said:


> If you are installing a different volume pot, check whether you need to widen the hole before starting your build.
> 
> When attaching anything to terminal 14U, try to keep it as clean as possible, because you will need every fraction of a millimeter you can get there, since a ton of stuff runs through there.
> 
> ...


 
  check and check. thanks.


----------



## Loquah

Quote: 





caracara08 said:


> any slightly more budget friendly recommendations for tube rolling?  I went ot the BH forum and looked up a few but theyre all expensive.  I received the tubes from BH but the 6080 (I think it is) has something loose inside it and its rattling.
> 
> Thank you.


 
   
  I started out trying a bunch of cheap tubes (all <$30) and found the following to be a nice upgrade from the stock. Each one sounds different and the combination of different power and iput tubes allowed me to tune the Crack quite differently depending on which headphones I was using (e.g. HD650s vs Beyer T1s)
   
*Power*
   

 Mullard 6080WA (great with HD650)
 GE 6AS7G (great with Beyer T1)
 RCA 6080 (great with HD650)
   
*Input*
   

 RCA Cleartop 12AU7 (great with HD650)
 Mullard ECC82 (great with Beyer T1)
 Genalex Gold Lion ECC82 / 12AU7 (can't remember which code it's officially listed as) - this isn't quite as good as the other 2, but readily available and BNIB


----------



## caracara08

Quote: 





loquah said:


> I started out trying a bunch of cheap tubes (all <$30) and found the following to be a nice upgrade from the stock. Each one sounds different and the combination of different power and iput tubes allowed me to tune the Crack quite differently depending on which headphones I was using (e.g. HD650s vs Beyer T1s)
> 
> *Power*
> 
> ...


 
   
  I was able to get the free upgraded tubes with my order.  I think that was the RCA 6080 and the RCA Cleartop 12AU7.. if I remembre correctly.  Can anyone else confirm?


----------



## Beefy

Quote: 





brunk said:


> I understand it's a good idea to put in the LEDs before the wires, installing the SB standoffs before wiring, and installing fly leads for my film caps. Is there anything else recommended? Thanks.


 
   
  You should prep something for mounting the film caps. Common solution is a sticky zip tie mount, but the sticky isn't really a good long term solution because they will eventually give way over time. I drilled out the top plate and screwed down the zip tie mounts I used: http://www.homedepot.ca/product/uv-black-mounting-base-bag-of-8/977480
   
  Quote: 





amcananey said:


> When attaching anything to terminal 14U, try to keep it as clean as possible, because you will need every fraction of a millimeter you can get there, since a ton of stuff runs through there.


 
   
  For the modification on page 19, you can use 14L. Makes it much easier at that terminal.


----------



## Zashoomin

Quote: 





doc b. said:


> There will be no surface mount soldering to be done in our kit, it will come with the surface mount parts already installed.


 
  Kinda sad but also kinda relieved.  That will cut the amount of work people have to do by like half and also Doc you won't get 50% of the people who ordered telling you they need a new pcb and parts.


----------



## brunk

Quote: 





beefy said:


> You should prep something for mounting the film caps. Common solution is a sticky zip tie mount, but the sticky isn't really a good long term solution because they will eventually give way over time. I drilled out the top plate and screwed down the zip tie mounts I used: http://www.homedepot.ca/product/uv-black-mounting-base-bag-of-8/977480
> 
> 
> For the modification on page 19, you can use 14L. Makes it much easier at that terminal.


 
  I did buy some zip tie mounts and some reusable zip ties. I think im going to mount them to the side of the case with some gorilla glue. Should make for a prettier faceplate, with the minor hassle of unzipping them to remove the cover. So, i can use 14L for the SB? Cool.


----------



## Doc B.

You haven't seen the board. It would be more like 100%.


----------



## Zashoomin

Quote: 





doc b. said:


> You haven't seen the board. It would be more like 100%.


 
  Haha that sounds like a challenge.  I would be willing to take it on if you give me a discount when I buy the DAC.


----------



## brunk

Quote: 





zashoomin said:


> Haha that sounds like a challenge.  I would be willing to take it on if you give me a discount when I buy the DAC.


 
  Might want to buy some insurance with that too 
	

	
	
		
		

		
			




   
  "We got your crack covered!"


----------



## Beefy

Quote: 





brunk said:


> I did buy some zip tie mounts and some reusable zip ties. I think im going to mount them to the side of the case with some gorilla glue. Should make for a prettier faceplate, with the minor hassle of unzipping them to remove the cover. So, i can use 14L for the SB? Cool.


 
   
  Frankly, I think gluing anything is a terrible idea. It is far too messy to be a non-permanent/serviceable solution, yet it is not robust enough to be 'properly' permanent.


----------



## brunk

Quote: 





beefy said:


> Frankly, I think gluing anything is a terrible idea. It is far too messy to be a non-permanent/serviceable solution, yet it is not robust enough to be 'properly' permanent.


 
  Hmm, maybe I can use industrial velcro instead of glue to mount it, i know that stuff is strong. I just don't want to make extra holes in the case if i can help it


----------



## Loquah

brunk said:


> Hmm, maybe I can use industrial velcro instead of glue to mount it, i know that stuff is strong. I just don't want to make extra holes in the case if i can help it




Some little screw holes might be preferable to possible damage caused if you ever need to remove glue / adhesive which can take chunks of timber with it. Your call of course and it's on the inside anyway - just my 5c worth.


----------



## Beefy

Quote: 





brunk said:


> Hmm, maybe I can use industrial velcro instead of glue to mount it, i know that stuff is strong. I just don't want to make extra holes in the case if i can help it


 
   
  Look, there's a corner! Lets cut it!
   
  The top plate is aluminium which drills very easily. Draw your holes accurately on paper (or print it out from CAD if you are that anal), carefully use a centre punch, then drill through the paper to prevent the filings from scratching anything. A nice socket-cap screw, and QED.
   
  And if you are painting the top plate anyway, there is even less cause for concern because you don't have to worry so much about scratches. Just make sure you let the paint set properly before screwing anything to it. The photo in my original build gallery 404's, but here it is again...... it really doesn't mess with the aesthetics at all.
   
  *


----------



## brunk

Oh, that's not too bad at all, thanks for the pic. I thought it would look much worse.
  Quote: 





beefy said:


> Look, there's a corner! Lets cut it!
> 
> The top plate is aluminium which drills very easily. Draw your holes accurately on paper (or print it out from CAD if you are that anal), carefully use a centre punch, then drill through the paper to prevent the filings from scratching anything. A nice socket-cap screw, and QED.
> 
> ...


----------



## Armaegis

I like it... Sort of like a buttoned up "formal" look, lol.


----------



## Beefy

Quote: 





armaegis said:


> I like it... Sort of like a buttoned up "formal" look, lol.


 
   
  I like the "those caps are *never* going to fall off" look.
   
  Should remember to drop you a private line, Armaegis. I'm moving to Winnipeg in 4 weeks......


----------



## Nic Rhodes

My crack is here  but stuck at PO depot awaiting on customs payment but it is the bank holiday weekend Tuesday at the earliest.


----------



## amcananey

That is the WORST feeling in the world...hang in there! (I bet this weekend is wide open, but the next three weekends you will be bogged down with work. Want to bet?)


----------



## Doc B.

The last of the kits ordered during the special shipped today, along with a few more recent orders. More kits will be shipping next week.


----------



## Loquah

doc b. said:


> The last of the kits ordered during the special shipped today, along with a few more recent orders. More kits will be shipping next week.




Any news on SEX orders, Doc?


----------



## brunk

Quote: 





loquah said:


> Any news on *SEX orders*, Doc?


 
  Ewww, with Doc B. ?!


----------



## kozmos

Mine is stuck in the customs too, I called them and they told me it would take over a week before they send it, probably gonna have to pay them for delaying the shipping time, sneaky bastards!
 Swedish customs sucks!


----------



## Armaegis

Quote: 





beefy said:


> Should remember to drop you a private line, Armaegis. I'm moving to Winnipeg in 4 weeks......


 
   
  Cool, just shoot me a PM. It's mostly me and DigitalFreak holding the fort these days. We have a lot of local members (over 40 by my last count) that I've seen on the forums, but I've only met about half of them.


----------



## bala

Received my Crack+Speedball, customs took just two days!...and they charged me nothing 
	

	
	
		
		

		
		
	


	




 (except the VAT - which turned out to be lesser than I expected). Thanks Doc & Queen.


----------



## Loquah

My GEC brown base arrived today courtesy of wolfdog (via eBay).


It sounds beautifully smooth. So much so that I had to switch out the Mullard ECC82 for RCA 12AU7 Cleartop. More impressions tomorrow, but seems like an improvement in smoothness and warmth without losing clarity and detail compared to the GE 6AS7GA I had been using.


----------



## Cryok95

Quote: 





loquah said:


> My GEC brown base arrived today courtesy of wolfdog (via eBay).
> 
> 
> It sounds beautifully smooth. So much so that I had to switch out the Mullard ECC82 for RCA 12AU7 Cleartop. More impressions tomorrow, but seems like an improvement in smoothness and warmth without losing clarity and detail compared to the GE 6AS7GA I had been using.


 

 Congrats, you now own the best or at least one of the best 6AS7G series tubes in the world 
	

	
	
		
		

		
		
	


	




 Too bad i can only afford the 5998


----------



## netmask254

It's hard to find some "spec" about this amp. I'm interested that whether it supports 220v voltage and what's the size of it?


----------



## kozmos

You can choose the crack with 240v transformer, so it's no problem


----------



## J-Pak

Silly question for Doc- do you guys send shipping emails? I'm just curious since I will probably be gone on vacation the second week of September. But it sounds like the kit should be here before then.


----------



## ben_r_

Quote: 





j-pak said:


> Silly question for Doc- do you guys send shipping emails? I'm just curious since I will probably be gone on vacation the second week of September. But it sounds like the kit should be here before then.


 

 They do. They forward you the UPS shipping confirmation with the USP tracking number. Might be different for those outside the US, but thats how it works here.


----------



## GaryPham

Do you guys know approximately how long shipping takes once it gets shipped out?  I'm really hoping that my kit gets shipped out either today or tomrorow since I'm leaving for vacation September 4th.  Going to be a doozy especially with the holiday this Monday....


----------



## ben_r_

Quote: 





garypham said:


> Do you guys know approximately how long shipping takes once it gets shipped out?  I'm really hoping that my kit gets shipped out either today or tomrorow since I'm leaving for vacation September 4th.  Going to be a doozy especially with the holiday this Monday....


 

 Being that your in the US, once it ships out and UPS sends you the confirmation email, UPS will tell you the expected delivery date, so youll know it very accurately.


----------



## Doc B.

Check your email for a shipping notice, Gary.


----------



## GaryPham

Quote: 





doc b. said:


> Check your email for a shipping notice, Gary.


 
  Awesome, thanks so much Doc!  I can now enjoy my vacation in peace knowing that my Crack is sitting on my table ready to be built upon my return = D


----------



## Loquah

The GEC brown base I received is beautiful, but I'm having a hard time finding the right 12AU7 (or equivalent) to pair with it. I have various 12AU7 options (Baldwin, Conn, etc.) as well as Mullard ECC82, RCA Cleartop 12AU7, and Genalex Gold Lion ECC82.
   
  I don't have speedball yet, so need to stick with 12AU7 / ECC82. Any suggestions?


----------



## W0lfd0g

^
   
  Try the Siemens silver plate ECC82.  Here are a couple of impressions from others:
   
  http://tubemaze.info/siemens-12au7-silver-plates/
   
  http://www.tubes.tw/shop/htm/review/review_brimar_ecc82_d_getter.htm
   
  Not cheap, but the GEC deserves a good companion.
   
  Try the Mullard (Philips) E80CC when you have the SB installed.
   
  Cheers!


----------



## Loquah

Quote: 





w0lfd0g said:


> ^
> 
> Try the Siemens silver plate ECC82.  Here are a couple of impressions from others:
> 
> ...


 
   
  Wolfdog, have you tried the Mullard ECC82?
   
  I have given it another go today and it pairs much better than I thought. My initial impression was that the Mullard was too smooth and was creating a "smooth overload" in conjunction with the GEC. I should add that I was using the line out from my RWAK100 at the time and it errs towards warmth ever so slightly.
   
  Listening to the non-SB Crack today via PC --> Audio-gd NFB-5.2, the sound is rich and warm, but beautifully detailed. Paired with the Beyer T1s, the sound is as close to perfect as I've heard with none of the edge that the T1s can sometimes create. I can still hear a poor, overly compressed recording vs a clean and open recording, but it's not because of harshness so much as the space and detail available in well-recorded tracks.


----------



## W0lfd0g

Hi Loquah

Yep - The Mullard ECC82 is a very nice example of the family. Which variety do you have?

I have not had the opportunity to hear it without the SB installed. Frankly, with the SB I couldn't hear a huge difference between members of the 12AU7/ECC82 family.

I can imagine it working well with the T1, T90 etc but it might be a "warmth overdose" with certain other headphones when using the GEC as the output tube. Depends what sound you are after.


Cheers


----------



## W0lfd0g

loquah said:


> The GEC brown base I received is beautiful, but I'm having a hard time finding the right 12AU7 (or equivalent) to pair with it. I have various 12AU7 options (Baldwin, Conn, etc.) as well as Mullard ECC82, RCA Cleartop 12AU7, and Genalex Gold Lion ECC82.
> 
> I don't have speedball yet, so need to stick with 12AU7 / ECC82. Any suggestions?




Just as a point of interest, I am not aware of Baldwin or Conn manufacturing their own tubes. From what I know they were manufacturers of musical instruments, including early electric organs that used tubes. From memory, I have seen Baldwin use Japenesse made 12AU7 tubes (Toshiba I think) and Conn use RCA clear tops.

Cheers


----------



## DefQon

I'm actually interested in what Doc's setup is at home...


----------



## Loquah

Quote: 





w0lfd0g said:


> Just as a point of interest, I am not aware of Baldwin or Conn manufacturing their own tubes. From what I know they were manufacturers of musical instruments, including early electric organs that used tubes. From memory, I have seen Baldwin use Japenesse made 12AU7 tubes (Toshiba I think) and Conn use RCA clear tops.
> 
> Cheers


 
   
  I think you're right. The Baldwin and Conn options appear to be generic relabels rather than specific variants of the 12AU7 family. The plates look slightly different, but not enough that I would think they're different models, just stock 12AU7s from different factories I expect.


----------



## DefQon

Quote: 





loquah said:


> I think you're right. The Baldwin and Conn options appear to be generic relabels rather than specific variants of the 12AU7 family. The plates look slightly different, but not enough that I would think they're different models, just stock 12AU7s from different factories I expect.


 
  Sylvania and later on RCA were major suppliers for Baldwin organs and Baldwin usually slapped there own red or yellow label/markings on the 12AU7 tubes predominantly used in there organs.


----------



## Loquah

I thought I'd take the chance to do some direct 12AU7 comparisons to share here. I used the same FLAC files for all tests running PC --> NFB-5.2 --> Crack (non SB) with GEC straight brown base 6AS7G --> Beyerdynamic T1. I began with John Schofield "Whip the Mule" on each tube then reviewed my findings with Daft Punk "Within" and Minnesota Orchestra "Snow Maiden - Dance of the Tumblers".
   
*Conn 12AU7 (green print) - NOS*
   

   
  This is my baseline tube as it was provided stock with the Crack kit. Sound is clean and defined. Nothing jumps out as exceptional, but also nothing at all to complain about. 
   
*Baldwin 12AU7 (yellow print) - NOS*
   

   
  This is also a stock tube and therefore show no real variance from the Conn tube above. There might be ever-so-slightly less clarity from the Baldwin, but it'd be normal variance, not a completely different sound style and may just be my ears adapting to the same track over and over! 
	

	
	
		
		

		
			




   
*Genalex Gold Lion ECC82 - Brand New*
   

   
  I can't decide if I like this tube. The mids are forward compared to the stock 12AU7s, but the stage is compressed in terms of forward depth and feels noticeably closer and smaller. The sound is still great, but I think I would lean towards the stock tubes for my current setup (as above). The Gold Lion would be great with a headphone that doesn't boast the potential to create a large stage (i.e. not HD800 / T1, etc.) and also with a headphone requiring subtle mid-range reinforcement. FWIW the piano solo on my test track sounds super sweet through this tube!
   
*RCA 12AU7 Cleartop - NOS*
   

   
   
  This tube is regularly touted as a top option for the Crack (without spending a fortune) and it's no surprise. It has a nicely balanced sound with great top end detail and a noticeably more open stage than the Gold Lion above. To my ears it's not miles ahead of the generic 12AU7s above, but it brings a certain refinement and delicacy that the generic options lack. It provides a bit more definition in the sound which helps make the soundstage seem a little larger and definitely more spacious.
   
  With the T1s I actually find the Cleartop to have a slightly tinny edge on some high frequencies - while this high frequency clarity paired perfectly with the HD650s, I find it a little distracting with the T1s which already have a spike at the 9k range (roughly). I feel like the Cleartop is showing me just a little too much of the cymbals and even some twang of the strings on higher piano notes - a nice trick to demonstrate its resolution, but ultimately a little distracting. I guess my verdict here is a resounding yes for phones with rolled off highs (i.e. HD6x0), but maybe not the best option for Beyer owners as most (but not all) Beyers seem to have the Beyer 8-9k treble spike. This also depends on the recording quality / emphasis as well.
   
*Mullard ECC82 - NOS*
   

   
  The thing I love about this tube is that it creates a really holographic sound. It doesn't massively extend the soundstage, but it seems to somehow recreate the ambience and space in the stage better than my other input tubes. It's definitely smoother than the alternatives above and my first impression is that I've lost detail, but on further listening I wonder if the detail has just been balanced out across all frequencies so nothing is jumping out. That would also explain the wonderfully spacious soundstage because no specific instrument or frequency is dominating the space.
   
*Final Verdict*
   
  If I really want to listen into the music, the RCA Cleartop might be my choice because it's got the edge in top-end clarity. If I'm after an enjoyable listening experience, I would choose the Mullard ECC82.
   
  Now if anyone can suggest something not quite as bright as the RCA Cleartop, but still with plenty of clarity (i.e. a little more resolving at higher frequencies than the Mullard) I'd be really interested. Does the Siemens silver plate fit that bill?


----------



## DefQon

Those first two tubes are by Sylvania. I had 50 of them. Still have 2 Baldwin ones that are bit different as they are made in the same factory as the British Mullards, flashes on powerup is a dead giveaway for a British dual triode tube.


----------



## W0lfd0g

A worthy addition to the Crack tube rolling record. Thanks for taking the time to share your experience.


----------



## W0lfd0g

defqon said:


> Those first two tubes are by Sylvania. I had 50 of them. Still have 2 Baldwin ones that are bit different as they are made in the same factory as the British Mullards, flashes on powerup is a dead giveaway for a British dual triode tube.




Interesting to know. Could be a good opportunity to get the Mullard sound at a fraction of the price. Do they have etch codes that give away heir origins? Other European ECC82s also have the same flash at start up.


----------



## Loquah

Those with the Speedball, would you recommend 12AU7/ECC82 equivs or 12BH7/ECC80 equivs?


----------



## dsound

Quote: 





loquah said:


> Those with the Speedball, would you recommend 12AU7/ECC82 equivs or 12BH7/ECC80 equivs?


 
  It depends on your preference.  I love the 12AU7 RCA Cleartop with the 5998 but much-prefer the 12BH7 with the RCA 6as7g. 
   
  To summarize, get both!


----------



## caracara08

was trying to hold off buying tubes but one of the supplied tubes is microphonic, or at least i think it is.  I was under the impression that touching the tube would cause some noise but there was none.  Without music playing, I hear a buzzing in the right channel that comes and goes.  tried two headphones, same thing, only on the right.  Any ideas?


----------



## MrEleventy

caracara08 said:


> was trying to hold off buying tubes but one of the supplied tubes is microphonic, or at least i think it is.  I was under the impression that touching the tube would cause some noise but there was none.  Without music playing, I hear a buzzing in the right channel that comes and goes.  tried two headphones, same thing, only on the right.  Any ideas?


Try leaving it on for a few hours. I had some NOS tubes that buzzed on first plug in. Went away after a day burning in.


----------



## dsound

Quote: 





caracara08 said:


> was trying to hold off buying tubes but one of the supplied tubes is microphonic, or at least i think it is.  I was under the impression that touching the tube would cause some noise but there was none.  Without music playing, I hear a buzzing in the right channel that comes and goes.  tried two headphones, same thing, only on the right.  Any ideas?


 
   
  If the problem persists after a couple days, you can also try using Deoxit to clean the leads.


----------



## caracara08

thanks guys. will do.  i hope it just needs some Deoxit and/or burn in time.


----------



## Doc B.

Quote: 





defqon said:


> I'm actually interested in what Doc's setup is at home...


 
  This may sound strange, but home is where I go to get away from audio. My setup at home is a 1956 Telefunken Salzburg console with the stereo upgrade amp, tonearm and speakers. Basically it gets turned on to FM on Saturday and Sunday night to listen to the local blues show. I also have a room dedicated to a front projection home theater with a 96" screen, that is slowly getting a full Blumenstein Audio surround speaker setup powered by our amps. I get my morning dose of home listening when I run 3 miles, via Pandora on an iphone with UE Triple Fi 10s.
   
  If you mean what do I run in a Crack amp, I usually put in a 5998 that a friend gave me a few years back (when they were going for $15!), and a Mullard 8136. But lately I have been using a Mainline for headphone listening. The Mainline sits here in the office for computer listening, currently with some Anax mod HD800s and a custom balanced cable. Bear in mind that we have a dedicated room for the big system here at Bottleheadquarters, and that is the primary system used for critical listening. That system is the following:
   
  Mac Mini music server running Amarra into a prototype Bottlehead DAC
  Analog Engineering modded Empire 208 with SME 309 and Haniwa HCTR01 cart, into a prototype all tube active step up preamp and Eros phono stage
  Nagra T Audio 1/4" tape machine with Bottlehead Tube Repro
  Studer A80 1" 2 track tape machine with Bottlehead Tube Repro
  Bottlehead BeePre 300B preamp
  Custom Bottlehead all tube three way crossover
  Seven Bottlehead Paramount amps per channel - one on Raal ribbon Tweeter, four in series on ATD Hypergraph 5" midrange, two driving an array of four 6.5" Exodus woofers. Drivers are in individual ported cabinets with heavy felt diffraction treatment, time aligned. Room has been treated.


----------



## sjeffrey

Note to self: need to visit Bottlehead HQ and listen to witness/listen to audio room they have setup


----------



## Doc B.

Everyone is most welcome to stop by for a listen. That's part of why we moved Bottleheadquarters a few years ago, to have a comfortable place for equipment auditions.


----------



## whatthedac

I like understanding how things work, especially things I plan on building.  While I've been (happily) waiting on the Crack to ship, I've put together some videos that others may find useful as well.  They are mostly beginner videos.
   
  If you guys have any videos that you'd like to add to this, then please let me know and I'll try to edit this post.
   
  Also, are there any good online videos that explain how the Crack or Speedball works?
     
The Bottlehead Crack DIY Tube Headphone Amp Kit - YouTube
How to Do It: Basic Soldering - YouTube
Electronics at Work - 1943 (Complete) - YouTube (a really old and neat video that describes how vacuum tubes work)
The Learning Series - Vacuum Tubes and Amps Part 2 - YouTube (describes the schematic for a vacuum tube / triode) 
The Learning Series - Vacuum Tubes and Amps Part 5 - YouTube (how tube amplifiers works)


How to use a Multimeter for beginners: Part 1 - Voltage measurement / Multimeter tutorial - YouTube (also describes what voltage is)


----------



## Loquah

Quote: 





whatthedac said:


> I like understanding how things work, especially things I plan on building.  While I've been (happily) waiting on the Crack to ship, I've put together some videos that others may find useful as well.  They are mostly beginner videos.
> 
> If you guys have any videos that you'd like to add to this, then please let me know and I'll try to edit this post.
> 
> ...


 
   
  Great links, thanks. I'm really interested to watch the Learning Series videos as I've built and love my Crack (SEX on the way as of today 
	

	
	
		
		

		
		
	


	




), but have never taken the time to understand the wonders of how tubes work.
   
  On a different note, after my post last night about the various input tubes I have, I reverted from the Mullard ECC82 back to the RCA Cleartop this morning and I'm hearing the details that the Mullard couldn't grab. Listening to "Jane" by Ben Folds Five I could actually hear the textures of the interplay between the piano strings which is pretty magic (note: it's an old-sounding piano in the recording and has some variance between the tuning of the strings on each single note - not something you should hear from a new, well-tuned piano)


----------



## DefQon

Quote: 





w0lfd0g said:


> Interesting to know. Could be a good opportunity to get the Mullard sound at a fraction of the price. Do they have etch codes that give away heir origins? Other European ECC82s also have the same flash at start up.


 
  No etch codes that I know of. I found it odd that my Baldwin's flashes a bit on start-up as they don't have the 4 pinched groves that British tubes such as Amperex and Mullard equivalents have and most other experienced users on AK forums have Sylvania or RCA based Baldwins, so my ones are a bit of a odd duck. Yes European made British based re-badge/equivalents do flash on startup. Holland plant Amperex and Mullard and few others that I can't think off the top of my head are also ones that flash on startup.


----------



## palmfish

defqon said:


> No etch codes that I know of. I found it odd that my Baldwin's flashes a bit on start-up as they don't have the 4 pinched groves that British tubes such as Amperex and Mullard equivalents have and most other experienced users on AK forums have Sylvania or RCA based Baldwins, so my ones are a bit of a odd duck. Yes European made British based re-badge/equivalents do flash on startup. Holland plant Amperex and Mullard and few others that I can't think off the top of my head are also ones that flash on startup.




OK, I need to find one of these. i dont care what they sound like, I just want a tube that flashes!


----------



## amcananey

Maxxximum CAPacity Crack --- a cautionary tale.
   
   
   
  [Note: the Mullard 12AU7 flashes. 
	

	
	
		
		

		
			





]


----------



## Loquah

Quote: 





amcananey said:


> Maxxximum CAPacity Crack --- a cautionary tale.
> 
> 
> 
> ...


 
   
  Great bedtime story, amcananey!!
   
  You've got me thinking about upgrading the power supply caps now... The Icar caps are what you used to replace the power supply electrolytics, yes?


----------



## amcananey

There are three 220uf 250V electrolytics in the power supply. The first two stick up straight. The last one is on the far left when looking at the underside of the Crack and sticks out horizontally. I used two Icar caps to replace the first two electrolytics, and I used two of the TEMCo oil-filled caps wired in parallel (to get a total of 200uf capacitance) for the last electrolytic. Of course, there is no reason you couldn't use 3 of the Icar caps, or 6 of the TEMCo caps, if you were so inclined.
   
  Best regards,
  Adam


----------



## Zashoomin

Quote: 





amcananey said:


> Maxxximum CAPacity Crack --- a cautionary tale.
> 
> 
> 
> ...


 
  You have created a monster.  The caps are bigger than the amp....I bet it sounds amazing but OH GOODNESS


----------



## amcananey

It sounds incredible. 

Vote on its looks here.


----------



## FlySweep

> Originally Posted by *amcananey* /img/forum/go_quote.gif
> 
> Maxxximum CAPacity Crack --- a cautionary tale.


 
   
  Good lord, man.. that thing is frightening (to look at.. but probably sounds amazing).  Only thing left for it to do is creep into your bedroom in the middle of the night and choke you with its cold, dead hands butt cheeks.
   
  BTW.. my Tesla ECC802S flashes on start-up, too.


----------



## Aeolus Kratos

Quote: 





amcananey said:


> Maxxximum CAPacity Crack --- a cautionary tale.
> 
> 
> 
> ...


 
   


 It is...huge 
	

	
	
		
		

		
		
	


	



   
  I bet this is gonna take you to heaven when you listen to it 
	

	
	
		
		

		
		
	


	



   
  Fantastic work, Adam!
   
  Enjoy your 'lovely' Crack! 
	

	
	
		
		

		
		
	


	



  Kratos.


----------



## DefQon

Quote: 





palmfish said:


> OK, I need to find one of these. i dont care what they sound like, I just want a tube that flashes!


 
  Amperex, Mullard's, pretty much any non low class British tube will flash. Though not all. All Mullard dual triode's (12xxx family) with a CV code in front will flash on powerup. 
   
  Quote: 





amcananey said:


> Maxxximum CAPacity Crack --- a cautionary tale.
> 
> 
> 
> ...


 
  What? LOL! Hardcore. You Sir have taken the extreme to the extreme.


----------



## gikigill

Not the SEX thread but wanted to ask if this attenuator would be suitable for the SEX,
   
  http://www.ebay.com.au/itm/VALAB-23-Step-Attenuator-Potentiometer-10K-Stereo-Log-/300537542974?pt=AU_Electronics_Audio_Amplifiers&hash=item45f96ef93e


----------



## Beefy

Quote: 





amcananey said:


> Maxxximum CAPacity Crack --- a cautionary tale.


 
   
  As much as I am a fan of DIY as a chance to go a bit nutty, thus goes well beyond even the remotest common sense. Exposed HV terminals is *such* a terrible idea.


----------



## amcananey

Yeah, I'm going to cover those with shrink tubing. Didn't plan on leaving those that way long-term.


----------



## BobJS

I've become disenchanted with my Little Dot MKIV/SE .... it's also an OTL amp .....
   
  Has anyone had an opportunity to compare the MkIV with the  Bottlehead Crack with Speedball?  Do these OTL amps go head to head?
   
  Please forgive me if this has already been discussed within this thread.  My search didn't find any mention of the LD MKIV.


----------



## brunk

Lol nice avatar with those big blue butt cheeks Adam!


----------



## palmfish

amcananey said:


> Maxxximum CAPacity Crack --- a cautionary tale.
> 
> 
> 
> ...




I love it!


----------



## Zashoomin

Quote: 





gikigill said:


> Not the SEX thread but wanted to ask if this attenuator would be suitable for the SEX,
> 
> http://www.ebay.com.au/itm/VALAB-23-Step-Attenuator-Potentiometer-10K-Stereo-Log-/300537542974?pt=AU_Electronics_Audio_Amplifiers&hash=item45f96ef93e


 
  No you need a 100k one but the same seller on ebay has one that is 100k as well so yes that will work very well.  Also another upgrade would be a alps blue pot.


----------



## amcananey

palmfish said:


> I love it!




Thanks, Palmfish. So do I. It has been a true labor of love. My very own Frankenbride!


----------



## whatthedac

amcananey, it won't be long before your Crack takes flight.


----------



## palmfish

```

```



amcananey said:


> Thanks, Palmfish. So do I. It has been a true labor of love. My very own Frankenbride!




It has a face only a mother could love! But I can relate to how proud and pleased you surely feel. 

I have been enjoying my Crack for more than a week now and I really can't imagine improving it over stock. It just makes my HD800 sound so good. Can you, if possible, describe how your Crack progressively changed, sound wise, as you progressed? Im curious because I really am happy and have no real desire to upgrade or modify mine at all, but of course I am ever curious.


----------



## GaryPham

Any of you guys have good tips on wood finish/varnish?  I'm hoping to get my BH crack lookin slick and shiny as glass =p


----------



## Loquah

Quote: 





palmfish said:


> Code:
> 
> ```
> 
> ...


 
   
  Palmfish, in addition to Adam's awesome hardware mods, I can highly recommend tube changes to get dramatically good improvements from the already excellent stock sound. I am completely blown away by the difference made by the GEC 6AS7 straight brown base and RCA 12AU7 cleartop. All up it's about a $200 upgrade and involves no time or soldering, but turns the Crack into an absolute killer (even without the Speedball!)
   
  Not saying you shouldn't follow in Adam's crazy footsteps as well though - I know I plan too! 
	

	
	
		
		

		
			




   
  Quote: 





garypham said:


> Any of you guys have good tips on wood finish/varnish?  I'm hoping to get my BH crack lookin slick and shiny as glass =p


 
   
  I am really happy with my Japan Black stain and then used a quality satin varnish (but you would want gloss for the glassy look). The best tips I learned are to smooth the finish with a super fine sand paper prior to each layer of varnish and keep the varnish thin (i.e. don't lather it on because you'll get an uneven surface).
   
  Some stain ideas I got from the Bottlehead forum threads involved staining and sanding to create an aged / uneven effect. Here are some shots of my process.
   

   

   

   

   
  I got lazy at the end and the finish shows some signs of brush strokes if you look closely, but it sounds too good and I don't want to take it away from my desk for further work!


----------



## palmfish

$200 tubes in my $200 amp isn't gonna happen...lol


----------



## W0lfd0g

Your loss!


----------



## Loquah

Quote: 





palmfish said:


> $200 tubes in my $200 amp isn't gonna happen...lol


 
   
  Fair point. I thought you were considering spending money on caps, etc. which will soon add up to similar figures.
   
  On the tube front, you can also get good improvements for less.
   
  My favourite combo before getting the GEC was a Mullard 6080WA and the RCA 12AU7 Cleartop. I paid just $37.50 plus postage for the 2 tubes and it's a significant improvement IMO.


----------



## amcananey

Loquah,

Although I show a Mullard 12AU7 in the pictures, I'm actually using the GEC 6AS7G (straight brown bass) with an RCA 12AU7 clear top right now (thanks, W0lfd0g!). I think this is probably the best combo I've heard with my Crack. I still need to do more testing to confirm, but it is interesting to hear you like this combo, too.

A much cheaper alternative to the GEC is the Bendix 6080 with solid graphite plates. I haven't used it since I got my two GECs, but I might even like that better than the Tung-Sol 5998s.

Best regards,
Adam


----------



## W0lfd0g

I agree, Adam.
   
  Bendix 6080WB with graphite plates + RCA clear top 12au7a = Very nice combination


----------



## palmfish

Everything Ive read from experienced owners says to install the Speedball first for the biggest improvement.


----------



## amcananey

I agree. I've been one of the most vocal advocates of doing just that.


----------



## amcananey

In terms of how my Crack has changed: 1. Installing the Speedball make my Crack quieter and seemed to improve resolution. 2. Installing the ClarityCap ESA 100uf coupling caps seemed to do the same thing, although I have to admit that there was a week between when I started installing the caps, and when I had them in and working, so I couldn't really do an A/B comparison, so I can't really speak to the nature of all of the changes. 3. Installing a film bypass cap on the last electrolytic cap in the power supply didn't seem to make a noticeable difference. 4. Using Harrison Labs inline RCA attenuators helped give me more room on the volume pot, and seemed to slightly tame the treble, although the bit about the treble might be imagined, since I found the attenuators to really be quite neutral. It may just be that because volume ramps up more gradually with the attenuators, I don't wind up overshooting the mark as much. 5. The GEC 6AS7G made my Crack quieter still. (I just got lucky, I'm not claiming this is a trait of all GEC 6AS7Gs, nor am I claiming that other tubes can't be just as quiet) 6. I wouldn't swear that installing the TKD had much of an audible effect at all. 7. Replacing the electrolytic caps in the power supply made a very noticeable difference in terms of bass extension, slam and tightness, and possibly increased overall resolution.


----------



## amcananey

I apologize that my previous post turned into a solid block of text without formatting, but there is some glitch in our computer system at work that causes this...


----------



## GrindingThud

What did you use for power supply caps?


----------



## amcananey

See here: http://www.bottlehead.com/smf/index.php/topic,4775.0.html


----------



## GrindingThud

I feel so inadequate... 


amcananey said:


> See here: http://www.bottlehead.com/smf/index.php/topic,4775.0.html


----------



## amcananey

If it makes you feel better, you can diss my creation (or not) here: http://www.head-fi.org/t/679064/maxxximum-capacity-crack 



Best regards,
Adam


----------



## palmfish

I was thinking of you when I commented on people who recommend the Speedball first.

Reading the rest of your response, it seems the power supply caps are really the only thing that made a significant change (besides the Speedball).

I am very happy with the stock sound, but do note that bass is bigger than neutral. Im deciding if I like it that way, or if I want to address it. My fear is that if I "fix" the bass, then it will sound just like all the solid state amps Ive owned. I mean, right now, switching back and forth between the Crack and Essence One, the bass is really the only difference I notice between them. I like the added "body" of the crack with most over-produced pop and studio recordings, but on some of my close-miked jazz recordings, double bass can sound bloated and I prefer the Essence One.


----------



## amcananey

I'll just throw this out there: I see you are using HD800s. In my view, the HD800s don't have bigger than neutral bass with the Crack. Instead, I would argue that the Crack is one of the few amps that can give the HD800s accurate bass. Other amps (especially solid state or WOT tube amps) result in "less than neutral" bass when paired with the HD800s. If you have been using the HD800s with a solid state amp for a while, I can understand how you might perceive the Crack as having boosted bass initially. Give the Crack some time so your ears can adjust. I suspect that you will soon find that you prefer the Crack for all genres.

Also: try an RCA 12AU7 clear top as your input tube. They are cheap, and they seem to yield a very neutral sound. What do you have in their right now?

And yes, the film caps in the power supply made the biggest difference after the Speedball, although I'm willing to bet the 100uf coupling caps were also pretty important. Coupling caps take time to burn in, which also makes A/B comparisons difficult,even under the best of circumstances.

Best regards,
Adam


----------



## palmfish

You make a very good point about the HD800. I will give it more time Adam - my Crack isn't going anywhere! Like I said, I am really enjoying my Crack and I have already told people it is the best sounding headphone amp I have ever owned. I will also check out the RCA clear top - I have read about them in a number of places...
   
  I'm using a CBS Hytron 5814A and matching CBS Hytron 6AS7G


----------



## DefQon

Quote: 





garypham said:


> Any of you guys have good tips on wood finish/varnish?  I'm hoping to get my BH crack lookin slick and shiny as glass =p


 
  Seal the wood before oil stain or you can just use multiple layers of oil stain (dark colour). Polyutherane (lacquer) spray or brushed on, but sprayed on promotes a finer finish. Buff between each coat (dried) with 200 grit sand paper (preferably wet under the tap) just kiss the previous layer so the next layer sticks on. The more layers you put on the more finer finish you end up with. I have 4 coats on mine and still unfinished. Can also polish it after the layers to have a fine acrylic like ultra gloss sheen to it.


----------



## dxanex

hey guys quick question:
   
  I've built a couple of Crack amps, but for the first time I am having issues with loud popping/hissing. I've ruled out the tubes and I believe I've narrowed it down to the Speedball transistors (need resolder)
   
  I'm just wondering how long I should wait before it's safe to poke around in there... does the Crack/Speedball need a long time to dump it's electrical charge after being unplugged?


----------



## amcananey

No. What you need to worry about are the capacitors, but if you built it properly, then there are bleeder resistors that drain the charge pretty quickly. If you wait a minute or so, you should be fine.
   
  Best regards,
  Adam


----------



## dxanex

Thank you for the quick response, amcananey.


----------



## Zashoomin

Quote: 





dxanex said:


> hey guys quick question:
> 
> I've built a couple of Crack amps, but for the first time I am having issues with loud popping/hissing. I've ruled out the tubes and I believe I've narrowed it down to the Speedball transistors (need resolder)
> 
> I'm just wondering how long I should wait before it's safe to poke around in there... does the Crack/Speedball need a long time to dump it's electrical charge after being unplugged?


 
  I wouldn't put my hand down there with lightning speed but give it like 30sec to let the caps drain and you should bee in the all clear.


----------



## drizek

So after taking a bit of a break from audio, I decided I wanted to upgrade my setup.
  
 I currently have a nuForce uDAC (first generation) that I use to drive my Triple.Fi 10s and Sennheiser HD 580s. 
  
 I picked up the Crack w/ Speedball from massdrop yesterday and am pretty excited. It will be my first real build.
  
 Of course, this being head-fi, I'm now thinking I need to upgrade my DAC. Any recs for some that will go well with my 580s?
  
 Currently the plan is to get HD 800s a year from now (when I will hopefully have an actual job) so I want something that works well with them, too.
  
 Any tips? Also, I notice a ton of people in here have 800s. Did you all pay full price for them or have there been some promotions going on?
  
 Also, I can't believe I've been on this site for 7 years now. Damn.


----------



## amcananey

For DACs, it is tough to beat the ODAC or the Schiit Modi for value, as long as you only need USB. If you go above that, I find the Audio-Gd DACs are well implemented and offer excellent value for money, although the array of options can be tough to decipher...


----------



## drizek

I was actually just looking at the Gd 3.33. Is that overkill?


----------



## sjeffrey

amcananey said:


> For DACs, it is tough to beat the ODAC or the Schiit Modi for value, as long as you only need USB. If you go above that, I find the Audio-Gd DACs are well implemented and offer excellent value for money, although the array of options can be tough to decipher...


 
 If drizek plans to upgrade to HD800 then I would suggest getting the next step up for a DAC to keep the price ratio closer.  Maybe a Schiit Bifrost?
 Or wait to see how much you'll like to build the Crack and get the Bottlehead DAC once they release it?


----------



## NoGood

Hey guys, how would the Crack compare with the Little Dot Mk III in order to drive the HD 600/HD 650?


----------



## kozmos

I can't speak for this dac because i haven't tried it yet but im going to buy the Abrahamsen DAC II, it has gotten some nice reviews here in sweden and it's ridiculous cheap.


----------



## Jmstrmbn

sjeffrey said:


> If drizek plans to upgrade to HD800 then I would suggest getting the next step up for a DAC to keep the price ratio closer.  Maybe a Schiit Bifrost?
> Or wait to see how much you'll like to build the Crack and *get the Bottlehead DAC once they release it*?


 
 I have the crack and a Nuforce HDP as a DAC I also plan on getting the 800s in the future and the only reason I have not bought a new DSD approved DAC yet is because I'm sure the bottlehead DAC will be a killer deal!  Using HD 600s for your perspective


----------



## calipilot227

nogood said:


> Hey guys, how would the Crack compare with the Little Dot Mk III in order to drive the HD 600/HD 650?


 
  
 MILES ahead. I found the Little Dot to be lacking in warmth and it sounded a little bland when I owned it. The Crack is one of the best amps I've heard with the HD600/650.


----------



## amcananey

Check my profile for an (incomplete) list of amps I have owned. The Crack is the best amp I have found for the HD800s, HD650s and HD600s bar none, even at (literally!) 10x the price. Yes, it is that good.


----------



## froger

amcananey said:


> Check my profile for an (incomplete) list of amps I have owned. The Crack is the best amp I have found for the HD800s, HD650s and HD600s bar none, even at (literally!) 10x the price. Yes, it is that good.


May I know what is the amp the Crack beats at 10 times it's price?


----------



## Loquah

froger said:


> May I know what is the amp the Crack beats at 10 times it's price?


 
  
 +1 - not because I doubt it, but because I love knowing how good this beast of an amp is!!
  
 I just finished installing the Speedball in my pre-existing Crack. I wish I could A/B it with the non-Speedball version because the sound was so good before (with GEC 6AS7G straight brown base + RCA Cleartop 12AU7) that I can't tell how much better it is 
	

	
	
		
		

		
			





.
  
 I know it sounds ridiculously good now through the Beyer T1s, but I have no real direct comparison to be amazed by. It does seem more articulate and transparent now, but it's hard to now how much of that is in my head due to my expectations...


----------



## amcananey

Woo Audio WA22 ($2,000) with Tung-Sol 7236 upgrade tubes ($160) + Sylvania 6SN7GT upgrade tubes ($330) + Sophia Princess 274B upgrade ($160).

But for what it's worth, with the HD800s I also preferred the Crack over the following:

- ECP Audio DSHA-1
- HiFiMAN EF-6
- Schiit Mjolnir
- Violectric V181
- Fully top-of-the-line AMB Beta 22 that I sold for over $2k
- Little Dot Mk VI+ with about $600 of upgrade tubes
- etc., etc.

To be clear, I would take a stock Crack over any of the above.


----------



## amcananey

Also: these aren't amps that I listened to for five minutes at a meet or that my friend has. These are amps I owned (or still own) and that I used extensively.


----------



## Loquah

The magic of the Crack must be in its simplicity I think. It is such an easy amp to enjoy - just add >250ohm headphones!

It's a bonus to be able to role tubes to adjust the sound.


----------



## FlySweep

So... the Ken Rad 6C8G (w/ round plates) arrived.. rolled it into the Crack.. then this happened:


----------



## Loquah

flysweep said:


> So... the Ken Rad 6F8G (w/ round plates) arrived.. rolled it into the Crack.. then this happened:


 
  
 Haha. I take it that's a good reaction?


----------



## Zashoomin

loquah said:


> Haha. I take it that's a good reaction?


 
  
 I was wondering the same thing.  Is that good or bad???? Or both?


----------



## FlySweep

zashoomin said:


> I was wondering the same thing.  Is that good or bad???? Or both?


 


loquah said:


> Haha. I take it that's a good reaction?


 
  
 INDEED!
  
 A few tube enthusiasts have opined to me that they found the Ken Rad 6C8G (RPs) to sound fairly similar to the (famed) Ken Rad 6SN7 (RPs).  Now, I've haven't had a chance to actually hear the highly regarded 6SN7 version.. but if the sound of the 6F8G variant is any indication, the 6SN7 version must certainly be something special.  The 6F8G's bass is definitely punchy and impactful.. w/ the focus being on the sub bass rather than the midbass.  The treble has a smooth, balanced (in reference to the midrange) presence and good depth  Treble is crisp & complimentary to the addictive bass and deep, engaging midrange.  It's certainly in the top two or three favorite tubes I've rolled into the Crack.


----------



## Nowhere

i took a chance on a crack + speedball that was modified by the user with caps, bypass, etc on ebay as i've wanted to try one for awhile and it's quite difficult to find a prebuilt one. i hope it works out.
 could someone perhaps give me a beginner's breakdown on tube rolling? this is my first tube amp and i want to try out different tubes here and there, is it as simple as finding out the compatible tubes and purchasing it and then plugging it in? that's it?
 does there need to be any synergy between the 2 tubes at all?
  
 also what's a good dac to go with it to bring out the "tubey" sound in the $200-250 USED range, i'm currently using an odac but would that be too neutral/analytical? i was thinking maybe a music streamer ii+ or a dacport lx, they're both highly recommended on headphonia.
  
 i'm using an hd600 currently but i plan to try to get a hd650 used in the near future.


----------



## amcananey

Yes, you can just plug in any compatible tube. If you find yourself using any tube other than a 12AU7, ECC82 or 6SN7 (via adapter) regularly as your input tube, you might want to consider some mods in order to optimize the amp for those tube types (e.g., 12BH7 or E80CC), but frankly I don't think it is worth it unless you are sure you will never want to use a 12AU7, ECC82 or 6SN7 again.

Some people claim there are synergies between certain tube combinations. There may well be, but the added benefit is small and trying to find reliable information on tubes, let alone two specific tubes in combination, is almost impossible. The bottom line is that almost every tube I've tried has sounded good in my Crack.

I'll let other comment on the DAC, as I'm not a big believer in differences between DACs once you get above the $100 price point and provided you account for differences in output signal strength.

As for the HD650s....just....don't. The HD600s are better. I've owned three pairs of HD650s. Each time I keep telling myself they can't be as bad as I remember, and each time I confirm that, yes, they are as bad as I remember. I know the HD650s are newer, have a higher number and cost more, but they are still worse than the HD580s/HD600s. Save your cash for something else. If you want an upgrade from the HD600s, save your pennies and buy a pair of HD800s when you can. They are absolutely amazing, especially out of a Crack. Skip the HD650s and HD700s.

Regards,
Adam


----------



## Nowhere

amcananey said:


> Yes, you can just plug in any compatible tube. If you find yourself using any tube other than a 12AU7, ECC82 or 6SN7 (via adapter) regularly as your input tube, you might want to consider some mods in order to optimize the amp for those tube types (e.g., 12BH7 or E80CC), but frankly I don't think it is worth it unless you are sure you will never want to use a 12AU7, ECC82 or 6SN7 again.
> 
> Some people claim there are synergies between certain tube combinations. There may well be, but the added benefit is small and trying to find reliable information on tubes, let alone two specific tubes in combination, is almost impossible. The bottom line is that almost every tube I've tried has sounded good in my Crack.
> 
> ...


 
  
 cool... thanks for the input. so the 12AU7, ECC82 are the 2 types of tubes i can choose from? without any modifications.
  
 i'm surprised you say that about the 650 as i've heard so much praise of them and they seem to fit a sound that i'm seeking over the hd600.
 i might simply buy them used to try them out and then resell them if i don't like them, i've read alot about them and it just seems they would fit a type of sonic signature with a tube that i'm looking for. a bit darker, more romantic with a little more bass over the hd600 from what i've read.
 i doubt i'll be able to afford the hd800 anytime soon hehe. just getting the crack + hd600 took alot of saving, i can probably get 1-2 more pair of used cheaper headphones and some tubes here and there and that's it for a long while on the audio front for a long time.


----------



## swmtnbiker

Opinions are like, well, you know... 
	

	
	
		
		

		
			




  
 The HD650 is enjoyed by a LOT of people. It's not one of the most talked about headphones here, years of discussion, for no reason. For some it's the perfect combination of performance to price and it scales extremely well. For some it's not their cup of tea. YMMV. The only real way to find out is to listen for yourself. I'll say this - for me the combination of the Crack+Speedball and the HD650 is heaven. They were made for each other.


----------



## amcananey

FWIW, the HD650 does not have more bass than the HD600. It simply has less treble.

I will say that the Crack is the amp that best compensates for the HD650's flaws. But the HD600 is still a better headphone with the Crack than the HD650s.

Are the HD650s bad headphones? Well, that's a matter of perspective. Compared to many, many, MANY headphones out there, they are obviously very good. But you can't compare a headphone in the abstract. You have to evaluate it based on price, and relative to its closest competition. The closest competition for the HD650 is the HD600, a headphone that costs less and performs better. That is the only reason I am so dismissive of the HD650. If the HD600 were slightly cheaper and slightly worse than the HD650, you could debate whether the loss in performance was worth the cost savings. If the HD600 were slightly better and slightly more expensive than the HD650, then you could debate whether it was worth paying extra for the better performance. But given that the HD600 is better AND cheaper, there isn't really a lot to discuss. We are talking about headphones that cost $500. That's 1/2 of a thousand. For that amount of money, we have a right to be picky, especially if Sennheiser is billing it as an "upgrade" over the previous model.

Many people who talk about the HD650s haven't done the same degree of testing and comparison that I've done. I've owned three pairs of HD650s, still own two pairs of HD600s and did own a pair of HD580s. I've also owned two pairs of HD800s (still own one) and a pair of HD700s (now sold), not to mention a ton of other headphones. Does that mean I'm unquestionably right? No. My subjective opinion is still my subjective opinion. But take a look at the Inner Fidelity review of the HD580 vs. HD600 vs. HD650. Tyll provides some objective support for my subjective opinion.

In my view, Sennheiser didn't add anything to the HD600 when creating the HD650. It only took away part of the upper end of the spectrum. In the bass and most of the mids, the HD650 and HD600 sound virtually identical. The missing treble is what makes the HD650 sound darker and slightly lifeless, and it leads people to believe the HD650s offer more bass, when they don't.

That doesn't mean that there aren't people who will prefer the HD650 sound signature over the HD600 sound signature, and that is certainly up to them. But the HD650 is not an objectively better headphone than the HD600 in terms of reproducing the audible frequency spectrum, it is worse. Far too many people here buy into the model numbering and cost-status hype of the HD650 and believe it must be better, just because it is "50" more and costs more...

Feel free to dismiss and/or ignore this post. If anyone wants to buy the HD650s, or has HD650s and likes them, that's perfectly fine by me. I'm just trying to give people additional information so they can make an informed decision on their next purchase/upgrade.

And to bring the discussion back on topic: the Bottlehead Crack is, in my experience, unquestionably the best amp for either the HD600 or the HD650! 

Best regards,
Adam


----------



## Nowhere

great, convincing points. .
 although if buying used they're around the same price usually, i see both the hd600 and 650 around 320-400 used.. and i have read that article you mentioned about the comparison.
  
 it might be that i'm easily swayed but you might have convinced me lol.  
 perhaps i will look to another headphone away from sennheiser sound instead of the 650.
  
 okay, i agree back on topic to the crack.


----------



## Jd007

In general less treble does mean more bass/mid-bass though. Frequency response shows the relative loudness of the frequencies, normalized at a certain point (eg 0dB at 1khz). If the treble region is lower you can think of it as the bass and mid regions being higher. Think of bass strength as the dB difference between bass region and other regions. Raising the bass response or lowering the treble response both increase that frequency response delta (in dB), as a result increases perceived bass.


----------



## skeptic

The same hd650/hd600 debate pops up from time to time if you skim back through the thread, and there's no right answer.
  
 Compare the FR graphs below and pick your poison.  hd650's have a little bit of mid-bass bloat (which makes them sound fuller but can also obscure details), hd600's have a mild treble peak around 2.5khz which *can* make them sound more clear.  On the downside, there are a lot of instruments (e.g. violin, piano, trumpet, etc.) that play fundamental frequencies > 2.5khz - so the hd600's will actually make some treble notes (not just overtones) sound louder than they are on the recording.  For me, that's a big strike against them, and I prefer hd650's to 600's (when I'm not listening to my hd800's). 
  
 Edit: oh and the paint job on the hd600's is ugly 
	

	
	
		
		

		
		
	


	



  

 As for tubes, you can also use 12bh7's in the front socket without any mods (assuming you have a speedball).  1950's Tung Sol 12bh7's can be had for under $30 and are my favorite input tube to date.  In the rear, you can run 6as7, 6as7g, 6080, 7236, and 5998.  The last two have higher gain and also higher transconductance than 6as7's/6080's.  They actually lower the output impedance of the amp and provide a slightly different flavor.


----------



## amcananey

The paint job on the HD600s is beyond ugly. No questions there. I actually like the HD580s in terms of looks...

You can certainly use 12BH7s without any mods. It won't harm the amp and will sound fine. But as indicated here: http://www.bottlehead.com/smf/index.php/topic,663.msg45199.html#msg45199, the Bottlehead team recommends removing the red LED's on the 9 pin socket and replacing them with 1/8 Watt 1.2K resistors when using the 12BH7, since it otherwise changes the operating point of the output tube.


----------



## Nowhere

thanks for the tube info, any tips on a reputable seller i can start with... (ebay and store)
 i don't plan to buy tons and tons of tubes, i'd prefer to buy a couple here and there  and then spend time with it and not switch tubes out all of the time.. more of a quality rather than quantity approach.
  
 i was looking at this place but they're not the cheapest ever, i like in some of them they have the option for "cryogenically treated".  haha that's awesome.
 https://www.upscaleaudio.com/12AU7/
  
 there's a Tung-Sol 12AU7W / 6189 platinum grade for $25... but of course the more expensive ones interest me more as usually the case hah.


----------



## skeptic

amcananey said:


> The paint job on the HD600s is beyond ugly. No questions there. I actually like the HD580s in terms of looks...
> 
> You can certainly use 12BH7s without any mods. It won't harm the amp and will sound fine. But as indicated here: http://www.bottlehead.com/smf/index.php/topic,663.msg45199.html#msg45199, the Bottlehead team recommends removing the red LED's on the 9 pin socket and replacing them with 1/8 Watt 1.2K resistors when using the 12BH7, since it otherwise changes the operating point of the output tube.


 
  
 Thanks for the heads-up!  I've been running various 12bh7s for quite a while now (based on much earlier posts in the tube rolling thread), and had thought they were a drop in replacement.  You've certainly piqued my interest as to the potential for further improvement.  On the downside, pulling the speedball boards to gain clean access to the a-socket is a bit of a hassle.  Going to have to think on this one.


----------



## amcananey

Also: remember how small and delicate those LEDs are. Once you pull those, there is no going back. They aren't expensive to replace, but I'm just saying...


----------



## skeptic

I hear you. I damaged one of those suckers inadvertently during my speedball install. Removing the speedball and then the broken led, and installing the new one, was definitely the most complicated maneuver I've attempted with a bh amp. 

Maybe instead, I should take this as an opportunity to try some new 12au7s


----------



## Zashoomin

Hey guys was looking for an upgrade to the stock pot and came across this: http://www.ebay.com/itm/281158933289?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649.
  
 It looks like it would be a lot easier to solder than with those small pins.  Anyone know if this is really an alps pot or not?  Its from hong kong.


----------



## whatthedac

Still haven't built the Crack yet.  What's the point of the LEDs?  They get installed underneath the tubes, right?  Is it just to let you know they are on?  To give it extra glow?


----------



## Loquah

whatthedac said:


> Still haven't built the Crack yet.  What's the point of the LEDs?  They get installed underneath the tubes, right?  Is it just to let you know they are on?  To give it extra glow?


 
  
 They're used as a resistor.


----------



## Zashoomin

loquah said:


> They're used as a resistor.


 
  
 They also show if everything is working. If they don't turn on than you know something is wrong.


----------



## whatthedac

> They're used as a resistor.


 
  
 Thanks.  Excuse my ignorance in the subject, but why not just use a typical resistor?
  
 Edit:  Zashoomin, that is a plus.


----------



## Jmstrmbn

Someone correct me if I'm wrong but I believe the LEDs are used to bias the voltage the tubes receive.  In older circuits biasing was done manually and often "wandered" in and out of the correct bias.  Thankfully, the LEDs negate the need for manual adjustment as the resistor changes so does the voltage the tube sees.  
  
 I don't have much background in circuits just some light reading so this may be totally of base and is more or less my understanding of the matter.
  
 Anyway hope it helps clear things up!
  
 John


----------



## netmask254

My location China has a voltage as 220V. I heard Crack has a 240v version, is it also usable in my area without any sound quality loss?

Besides, can someone give a rough ship weight of Crack since I need to calculate the oversea ship cost. Thanks a lot!


----------



## clowkoy

You should have no problem running a 240-volt crack in your country.
You can go to the Bottlehead website, put a crack in the cart and it will calculate the shipping cost.


----------



## Zashoomin

whatthedac said:


> Thanks.  Excuse my ignorance in the subject, but why not just use a typical resistor?
> 
> Edit:  Zashoomin, that is a plus.


 
  
 Well they also are diodes so current can only run in one direction.  If that helps.


----------



## Aeolus Kratos

flysweep said:


> INDEED!
> 
> A few tube enthusiasts have opined to me that they found the Ken Rad 6C8G (RPs) to sound fairly similar to the (famed) Ken Rad 6SN7 (RPs).  Now, I've haven't had a chance to actually hear the highly regarded 6SN7 version.. but if the sound of the 6F8G variant is any indication, the 6SN7 version must certainly be something special.  The 6F8G's bass is definitely punchy and impactful.. w/ the focus being on the sub bass rather than the midbass.  The treble has a smooth, balanced (in reference to the midrange) presence and good depth  Treble is crisp & complimentary to the addictive bass and deep, engaging midrange.  It's certainly in the top two or three favorite tubes I've rolled into the Crack.


 
 May I ask what are the rest of your favorite tubes? I'm using the Raytheon 6SN7 thanks to your recommendation which you posted about a month ago and I love it!
  
 Just be curious if the Raytheon is still in your favorite tube list


----------



## trentrosa

Wow!

Finished my Crack today. I'm a first time diy guy and noob with the soldering iron. Luckily, the only mistake I made was a backwards rectifier, blew a fuse. Honestly I'm quite proud of myself.

With my HD650s, I first listened to some Waylon Jennings, Ronnie Milsap, and Allison Krauss, immediately noticing tighter bass and amazingly clearer instrument separation opposed to my fiio e11.

Very well done on the Crack Doc. B, wonderful investment.


----------



## Zashoomin

trentrosa said:


> Wow!
> 
> Finished my Crack today. I'm a first time diy guy and noob with the soldering iron. Luckily, the only mistake I made was a backwards rectifier, blew a fuse. Honestly I'm quite proud of myself.
> 
> ...


 
  
 Congrats man and enjoy.  Once the DIY bug bites it doesn't let go.  Don't say I didn't warn you


----------



## brunk

zashoomin said:


> Congrats man and enjoy.  Once the DIY bug bites it doesn't let go.  Don't say I didn't warn you


 
  
 LOL i still don't have my crack complete yet because of some parts i ordered went missing and are now on backorder. However, I now have a DIY Lightspeed Attenuator and First Watt F5 clone in the works. I'm in parts up to my elbows!


----------



## amcananey

How much is the Lightspeed? I assume there are multiple options, so if you could describe yours and how much it cost, that would be great.

Thanks,
Adam


----------



## netmask254

clowkoy said:


> You should have no problem running a 240-volt crack in your country.
> You can go to the Bottlehead website, put a crack in the cart and it will calculate the shipping cost.


 
 Thanks for your advice!


----------



## brunk

amcananey said:


> How much is the Lightspeed? I assume there are multiple options, so if you could describe yours and how much it cost, that would be great.
> 
> Thanks,
> Adam


 
  
 I believe the original lightspeed cost around $700.
  
 There are several different approaches you can take. It can range from $50 in a cardboard box, to $2k for a fully decked out unit. I spent about $250 on my project and that includes a remote control!
  
DIY LDR3X board from Tortuga Audio. I got it on promo sale for $195, I can't tell if it's still on promo or not because the site is currently down. All i needed to buy was a suitable power supply, steel enclosure (with enough space for addon board in future), chassis jacks (RCA/PSU), status LED, and some wire.
  
 If you want to go full-blown DIY without remote you can get matched LDRs here. Soon as you go into remote control territory, Tortuga Audio is the better deal because most the work is done for you. If you would like an assembled unit that has a very good price with remote, the EVA 2 is a great choice, but who knows when it will be back in stock.


----------



## amcananey

Cool, thanks for the info and links!

Best regards,
Adam


----------



## brunk

amcananey said:


> Cool, thanks for the info and links!
> 
> Best regards,
> Adam


 
  
 No prob Adam 
	

	
	
		
		

		
		
	


	



  
 My LDR unit has shipped, but I'm waiting on a back order from pcX to be able to complete BOTH my Lightspeed and Crack lol. I'm hoping it ships this week!
  
 EDIT: LDR3X diagram picture below
  
  


Spoiler: LDR3X diagram


----------



## J-Pak

flysweep said:


> INDEED!
> 
> A few tube enthusiasts have opined to me that they found the Ken Rad 6C8G (RPs) to sound fairly similar to the (famed) Ken Rad 6SN7 (RPs).  Now, I've haven't had a chance to actually hear the highly regarded 6SN7 version.. but if the sound of the 6F8G variant is any indication, the 6SN7 version must certainly be something special.  The 6F8G's bass is definitely punchy and impactful.. w/ the focus being on the sub bass rather than the midbass.  The treble has a smooth, balanced (in reference to the midrange) presence and good depth  Treble is crisp & complimentary to the addictive bass and deep, engaging midrange.  It's certainly in the top two or three favorite tubes I've rolled into the Crack.


 
  
 I agree 6F8G are terrific tubes, electrically identical to 6SN7, so there shouldn't be any reason for them to sound too different if at all. There are a lot of different ones out there, I have tried around 5-7 different brands. In my experience VT-99 military labeled brands being my favorite. Will need to check my listening notes for more detail.


----------



## brunk

Good news, my backordered products have shipped today and will be arriving this week! Finally get to complete my Crack and Lightspeed attenuator


----------



## dsound

Just ordered the DT770 Premium (600Ohm) version to use with the Crack. 
  
 Sweet isolated blisss.


----------



## netmask254

Does crack consume much power and generate lot of heat?
  
 I sold my Valhalla not because of its sound, but because it's too hot to get a good user experience in summer. Valhalla has a rated power consumption of 35W, however I can't get any spec on Crack 
  
 I'm also interested its size.


----------



## Zashoomin

netmask254 said:


> Does crack consume much power and generate lot of heat?
> 
> I sold my Valhalla not because of its sound, but because it's too hot to get a good user experience in summer. Valhalla has a rated power consumption of 35W, however I can't get any spec on Crack
> 
> I'm also interested its size.


 
  
 It is larger than the valhalla mainly it is taller because of the wooden stand and because everything is point to point instead of put neatly onto a PCB.  Also the tubes and also transformer run pretty hot meaning that the plate that everything sits on will be one giant heat sink and will be a bit warm as well.


----------



## trentrosa

netmask254 said:


> Does crack consume much power and generate lot of heat?
> 
> I sold my Valhalla not because of its sound, but because it's too hot to get a good user experience in summer. Valhalla has a rated power consumption of 35W, however I can't get any spec on Crack
> 
> I'm also interested its size.


 
  
 As zash said, the resistors beneath the aluminum plate heat it up making it rather warm, as with the tubes, however that's the way amps are, they mostly run warm. I do not find the heat of the crack to be an issue at all. The volume knob is comfortable to the touch, and it's not radiating heat my way as I sit beside it.
  
 Good luck


----------



## Armaegis

The big tube is hot enough to burn you. So is the vent area just above the big resistors. The Speedball upgrade does seem to cut down on that heat though (or dissipates it more widely so it doesn't seem as strong).


----------



## Zashoomin

armaegis said:


> The big tube is hot enough to burn you. So is the vent area just above the big resistors. The Speedball upgrade does seem to cut down on that heat though (or dissipates it more widely so it doesn't seem as strong).


 
  
 Well you get rid of two of the large resistors leaving you with just a couple left.  Also the heat splitters do a good job of not getting too hot. Oh and don't touch the tube like I did because your curious...that was not the smartest thing I have done.  Lets just say it hurt.


----------



## DefQon

amcananey said:


> Woo Audio WA22 ($2,000) with Tung-Sol 7236 upgrade tubes ($160) + Sylvania 6SN7GT upgrade tubes ($330) + Sophia Princess 274B upgrade ($160).
> 
> But for what it's worth, with the HD800s I also preferred the Crack over the following:
> 
> ...


 
  
 Really shows how amazingly different everybody's impressions are. For the HD800 I'd pick the VI+ over the Crack easily any day of the week. B22 is a hit and miss and same with the Violectric but superb with other headphones. The Crack is definitely good for it's value and performance but at the end of the end it is still a low-mid tier amp that greatly synergises more with the HD580, 600 and 650 than the high z Beyer's and the HD800's. 
  
 You're the first poster I've heard that would pick the HD800's running off the Crack over that list of amplification.


----------



## amcananey

I may be the first person to prefer the Crack over that specific list of amplification, but I'm hardly the first person to think that the Crack works particularly well with the HD800s.

The LD Mk VI+ is indeed a great amp. But bear in mind that it was really optimized for use with planars and inefficient, low impedance headphones. I think LD recommends the Mk VIII for use with high impedance cans. I haven't heard the Mk VIII. FWIW, I still have my Mk VI+, so I do appreciate its performance with other cans. I'm just guessing here, but I think the Crack benefits from its simplicity compared to the LD VI+. Fewer tubes and no need for matched pairs and quads. My LD Mk VI+ tubes are incredibly closely matched, but even so, 6 tubes vs. 2, when the extra power isn't needed? Something has to give somewhere...

The Beta 22 I pretty much hated. Cold and lifeless. Detailed but totally lacking in PRAT or musicality. Can't tell you how disappointed I was. I really tried to love it, but eventually had to throw in the towel and just sold it. I prefer the M^3 over the Beta 22 by a fair margin.

The Violectric is actually a brilliant amp. One of, maybe even "THE", best I've ever heard overall. It works incredibly well with almost any headphones you throw at it. It is amazingly versatile. Dead quiet, yet with power to spare, even for my HE-6s and K1000s. All wrapped up in an impossibly small and power efficient package. But, in my experience, it is not the best amp for the HD800s in particular. It does a very good job, but I find bass is any area where the Crack is noticeably better with the HD800s. I still have my V181 as well, and I don't have any plans to sell it.


----------



## DefQon

Yeah fair enough.
  
 I don't know why people hyped the HD800 + B22 combo as unbelievable sounding and a good synergising combo. The B22 + HD800 is as you describe, just cold, clinical and lifeless, if there is anything the HD800 needs is a bit more body and meat to the sound to round the treble peak off a bit, tubes is a hit and miss (I found it sometimes made things bit too euphonic and syrupy sounding, taking too much of what I liked and added too much of what I disliked) but some solid states really do sound well with it (Phonitor for one).
  
 Yes the LD MK VIII SE is the VI+ version to drive high z headphones but not suited for planars. The HD800 still worked fine off my VI+ but I still preferred it over the Crack. 
  
 The Crack + any of the HD580/600/650 can's is a different story. A good $1k end game setup right there, throw in a fancy cables a good DAC and you still have enough money to buy yourself a beer within the $2k bracket.


----------



## amcananey

Have you heard the LD Mk VIII? To say I am curious about it is a serious understatement...

Also, FWIW, I didn't much like the Beta 22 with any of my other cans either. I don't doubt it's technical sophistication, but as a device for listening to music, it basically seemed like a complete fail TO ME. I know there are people who love their Beta 22s, and I don't want to get into an argument with anyone over this -- I'm just relaying my personal experience in my setup with my cans.

Best regards,
Adam


----------



## caracara08

I also really, really enjoyed the Vio V200 when I had it.  That and the M3 I had custom built were the only two solid state desktop amps I truly enjoyed.  That said, I am done with amps with my Crack.  I just need to upgrade my DAC and maybe add another headphone and I am done (possibly the HD800 down the line).


----------



## FlySweep

caracara08 said:


> I also really, really enjoyed the Vio V200 when I had it.  That and the M3 I had custom built were the only two solid state desktop amps I truly enjoyed.  That said, I am done with amps with my Crack.  I just need to upgrade my DAC and maybe add another headphone and I am done (possibly the HD800 down the line).


 
  
 Agreed.. I loved the V200.. with everything I threw at it.. from custom IEMs.. to the HD800.  It's a phenomenal amp.. and one of the few solid state (desktop) amps I could see my self living with, indefinitely.  The V200 (and Violectric's amps, in general) absolutely love planars, too.  The Crack, V200, and the TBI Millenia are my favorite amps for the HD800.  I will be buying the balanced version of the V200 when it drops (in 2014, per Fried).


----------



## caracara08

flysweep said:


> Agreed.. I loved the V200.. with everything I threw at it.. from custom IEMs.. to the HD800.  It's a phenomenal amp.. and one of the few solid state (desktop) amps I could see my self living with, indefinitely.  The V200 (and Violectric's amps, in general) absolutely love planars, too.  The Crack, V200, and the TBI Millenia are my favorite amps for the HD800.  I will be buying the balanced version of the V200 when it drops (in 2014, per Fried).


 
  
 Balanced version?? aw man. its a sign. when i upgraded my cable, for my HD650, i did it balanced with an adapter... even though i didnt have any plans to own a balanced amp.  hmm..  any idea on pricing?


----------



## amcananey

Guys, the balanced version of the V200 essentially already exists. Its called the V181 and I own it. It's wonderful. They may be coming out with a higher-end balanced amp, but I would consider the V181 the balanced version of the V200.

In any case (and I realize I am partially to blame), we should bear in mind that this thread is really about the Crack.

Regards,
Adam


----------



## FlySweep

caracara08 said:


> Balanced version?? aw man. its a sign. when i upgraded my cable, for my HD650, i did it balanced with an adapter... even though i didnt have any plans to own a balanced amp.  hmm..  any idea on pricing?


 
  
 HA!  Getting a balanced adapter for headphones is the _worst_... cause I want all my (SE) upstream gear to be balanced now, too.. LOL.
  
 No ideas on pricing on the balanced, V200.. but, for me, it's one of those, "close-your-eyes-and-click-buy," type of things.. cause I'm an unabashed, Violectric "fanboy" (lol).  After having owned two of their amps (and presently having one of their DACs), I'm convinced Fried Reim is an extremely tiny human that lives in the folds of my wallet.


----------



## caracara08

amcananey said:


> Guys, the balanced version of the V200 essentially already exists. Its called the V181 and I own it. It's wonderful. They may be coming out with a higher-end balanced amp, but I would consider the V181 the balanced version of the V200.
> 
> In any case (and I realize I am partially to blame), we should bear in mind that this thread is really about the Crack.
> 
> ...


 
  
 All your fault Adam!  last point, i was under the impression that the V181 was a lesser balanced amp. Could be wrong. 
  
 In any case, I still have to post more pictures of my Crack that Zashoom built for me.  Absolutely perfect.


----------



## netmask254

trentrosa said:


> As zash said, the resistors beneath the aluminum plate heat it up making it rather warm, as with the tubes, however that's the way amps are, they mostly run warm. I do not find the heat of the crack to be an issue at all. The volume knob is comfortable to the touch, and it's not radiating heat my way as I sit beside it.
> 
> Good luck


 
  
 Thanks a lot for your info!
  
 Looks like I need to adjust myself to accomodate it, maybe a good idea to buy it some months later in the winter.


----------



## amcananey

The heat from the Crack really isn't objectionable at all. I've had amps that really run hot. The Crack isn't one of them.


----------



## DefQon

amcananey said:


> Have you heard the LD Mk VIII? To say I am curious about it is a serious understatement...
> 
> Also, FWIW, I didn't much like the Beta 22 with any of my other cans either. I don't doubt it's technical sophistication, but as a device for listening to music, it basically seemed like a complete fail TO ME. I know there are people who love their Beta 22s, and I don't want to get into an argument with anyone over this -- I'm just relaying my personal experience in my setup with my cans.
> 
> ...


 
  
 Nope it seemed pointless for me own a VIII when I had the VI+, but I have owned and (still own) some of those amp's you listed including the Crack. The B22 + HD800 = woeful but the B22 + HD600/650 and the LCD2's are really awesome sounding.


----------



## DefQon

amcananey said:


> Guys, the balanced version of the V200 essentially already exists. Its called the V181 and I own it. It's wonderful. They may be coming out with a higher-end balanced amp, but I would consider the V181 the balanced version of the V200.
> 
> In any case (and I realize I am partially to blame), we should bear in mind that this thread is really about the Crack.
> 
> ...


 
  
 Actually that is what I thought at the start as well. The V181 is the balanced version of the V100 not the V200. SE I couldn't pick much difference between the V200 and V181 (neither did I with the V100 and V200).
  
 Back on the topic.


----------



## brunk

Can anyone comment on a 12BH7 + JH13C combo compared to the usual 12AU7 clear top + 6080, or variants of those 4 tubes? I have them and am curious on impressions.


----------



## W0lfd0g

brunk said:


> Can anyone comment on a 12BH7 + JH13C combo compared to the usual 12AU7 clear top + 6080, or variants of those 4 tubes? I have them and am curious on impressions.


 
 Do you mean the 6H13C?


----------



## brunk

w0lfd0g said:


> Do you mean the 6H13C?


 
  
 oops, yeah i do


----------



## DefQon

I personally hate the winged 6H13C 6AS7G Russian equivalent for anything that takes the tube. Rugged, built like a tank and long lasting - indeed, good sounding - No.


----------



## brunk

defqon said:


> I personally hate the winged 6H13C 6AS7G Russian equivalent for anything that takes the tube. Rugged, built like a tank and long lasting - indeed, good sounding - No.


 
  
 These are the tubes that came with my kit. I think i got the promo tubes. Would a 12BH7 + this RCA 6080 be a good combo, or stick with what's pictured?


----------



## DefQon

brunk said:


> These are the tubes that came with my kit. I think i got the promo tubes. Would a 12BH7 + this RCA 6080 be a good combo, or stick with what's pictured?


 
  
 Depends on yourself though. If you like the sound and not curious, don't buy more tubes (it leads to a dirty and addictive habit). 
  
 My personal crack uses a Psvane grade A 12AU7 and Ratheon 6080's.


----------



## W0lfd0g

defqon said:


> Depends on yourself though. If you like the sound and not curious, don't buy more tubes (it leads to a dirty and addictive habit).
> 
> My personal crack uses a Psvane grade A 12AU7 and Ratheon 6080's.




Use a GEC 6AS7G brown base and a 1959 Philips 7316 - Love this combination.

My name is Nathan and I am a tube-aholic.


----------



## DefQon

w0lfd0g said:


> Use a GEC 6AS7G brown base and a 1959 Philips 7316 - Love this combination.
> 
> My name is Nathan and I am a tube-aholic.


 
  
 I got over the GEC 6AS7G phase. Good sounding tube but definitely not worth the asking price on ebay nowadays.


----------



## amcananey

My experiences trying 12AU7s (and ECC82s), 12BH7s, E80CCs and 6SN7s -- and taking Bottlehead guidance into account -- has firmly convinced me that the best thing to do is to stick with 12AU7s and their ECC82 equivalents. There are plenty of these out there, so you are hardly limiting your ability to roll tubes forever. And you will be using the tubes that the Crack circuit is optimized for. 

If your goal is the best possible sound quality, and you don't want to use 12AU7s / ECC82s, then I think you should modify your Crack for the tube type you want to use. For 12BH7s, this means replacing some of the LEDs on the 9-pin socket with resistors. For the 6SN7s, it means replacing the nine-pine socket with an octal socket so you don't need to use an adapter. 

This isn't just a matter of convenience, but rather one of performance. I have FOUR 6SN7 --> 12AU7 adapters at home with three different designs from three different manufacturers. They ALL result in unacceptable noise, even when used with 6SN7s that are dead quiet in other amps. And my Crack is dead quiet when used with my various 12AU7s.

Regards,
Adam


----------



## brunk

amcananey said:


> My experiences trying 12AU7s (and ECC82s), 12BH7s, E80CCs and 6SN7s -- and taking Bottlehead guidance into account -- has firmly convinced me that the best thing to do is to stick with 12AU7s and their ECC82 equivalents. There are plenty of these out there, so you are hardly limiting your ability to roll tubes forever. And you will be using the tubes that the Crack circuit is optimized for.
> 
> If your goal is the best possible sound quality, and you don't want to use 12AU7s / ECC82s, then I think you should modify your Crack for the tube type you want to use. For 12BH7s, this means replacing some of the LEDs on the 9-pin socket with resistors. For the 6SN7s, it means replacing the nine-pine socket with an octal socket so you don't need to use an adapter.
> 
> ...


 
  
 I have an EH 12BH7, do you find better performance after the proper modification than the 12AU7?


----------



## amcananey

Can't say. I didn't find my 12BH7s to be better than my 12AU7s in an un-modified Crack. The Bottlehead guys recommend modding the Crack if you plan on using 12BH7s. I didn't want to get locked into 12BH7s, so I never made the recommended mod to my Crack.


----------



## brunk

amcananey said:


> Can't say. I didn't find my 12BH7s to be better than my 12AU7s in an un-modified Crack. The Bottlehead guys recommend modding the Crack if you plan on using 12BH7s. I didn't want to get locked into 12BH7s, so I never made the recommended mod to my Crack.


 
  
 Yeah, I am debating if i should put the resistors in first thing and save the LEDs for later, but i just dont know. Perhaps if there is a Mouser/Digi-Key part number for those LEDs i would roll a couple times and see what seems best. Do you know the part number by chance?
  
 EDIT: A quick search turned up the LED as HLMP-6000


----------



## amcananey

Those LEDs are not fun to install. In fact, they might even be the worst part of the build. They are relatively delicate and you're working in a small, crowded area of the amp. My desire to muck around with that socket multiple times is exactly zero.

You may be more skilled and/or patient, but I just don't have the temperament for it...

Best,
Adam


----------



## Nowhere

here's my reaction to listening to the bottlehead crack + speedball on the hd600 for the first time. (from the hd600 thread). just got mine and listened to a few songs on it. very satisfied. 
  
 first reaction follows:
  
 -------------------------
  
  OMG!!! just received the bottlehead crack + speedball i ordered, i've never thought music could sound this good.. i started to tear up as a unstoppable reaction to the experience, i almost can't listen to it as i feel i'm unworthy to hear these sounds that are floating around me so ethereal. BY THE STARS! literally taking my breath away.
  
 listened to around 5 songs on it so far and just wow, wow, wow! mindblowing.
  
 don't even know how to describe it except heavenly or ethereal.
  
 listening to Sugar Ray - Spinning Away from the beach soundtrack atm and it's transcendent. :O
  
 just had to vent somehow to my reaction from just now hearing this for the first time.
  
 humbled.


----------



## amcananey

LOL! HD600 + Crack is indeed sublime, and amazingly cheap for what you get. That specific combo easily outperforms most other amp + headphone combos costing many times more.

Congratulations and enjoy it!

Best regards,
Adam


----------



## Nowhere

indeed, sometimes things actually live up to the hype. 
 couldn't be happier with the sound i'm hearing from that combo.


----------



## whatthedac

Nowhere, that's the experience I'm hoping for.  I ordered the HD 650's about a month ago with the C5 (to hold me over until the Crack ships).  My friend asked me how the combo was and I said, "I definitely notice a difference when I listen to my 650's for a while and then put on my other (inexpensive) headphones -- they now sound muffled.  But, I was expecting something more mind blowing."
  
 I think the crack will be what I'm looking for, but I ordered it without the speedball.  A few weeks later I then saw it go on sale with the speedball (for only $25 more than what I paid) and was tempted to cancel my existing order and get the deal, but I thought I'd support the small biz.  I can always get it later and will now have something else to look forward to.


----------



## Nowhere

whatthedac said:


> Nowhere, that's the experience I'm hoping for.  I ordered the HD 650's about a month ago with the C5 (to hold me over until the Crack ships).  My friend asked me how the combo was and I said, "I definitely notice a difference when I listen to my 650's for a while and then put on my other (inexpensive) headphones -- they now sound muffled.  But, I was expecting something more mind blowing."
> 
> I think the crack will be what I'm looking for, but I ordered it without the speedball.  A few weeks later I then saw it go on sale with the speedball (for only $25 more than what I paid) and was tempted to cancel my existing order and get the deal, but I thought I'd support the small biz.  I can always get it later and will now have something else to look forward to.


 
  
 hopefully you obtain a similar experience as i have... try not to expect to be blown away or that it will be the most amazing thing ever because oftentimes if you do that even if something is great it becomes a letdown. i knew it would be great but kept to a realistic expectation and just kind of let it be what it was going to be.
  
 mine has the speedball, some minor upgrades here and there from the previous owner and i'm using a great rca cable so i can't say if it will be the exact same experience without being the exact set up as i have. and since i never heard the basic crack unit i can't compare if mine is that different.
  
 well, anyway i hope it works out for you.. if it's even close to what i'm hearing from my set up i can't imagine anyone being disappointed.


----------



## FlySweep

One the really great things about the Crack + SB is that not only does it sound fantastic with the 600/650, if you're ever inclined to move from the HD6x0 to the HD800.. there's no need to fret about finding a suitable amp for the Senn flagship: the Crack sounds TERRIFIC w/ the HD800.  I've heard the HD800 on a number of well regarded amps.. and, IME, the Crack + SB remains one of the best pairings, regardless of price.


----------



## amcananey

flysweep said:


> One the really great things about the Crack + SB is that not only does it sound fantastic with the 600/650, if you're ever inclined to move from the HD6x0 to the HD800.. there's no need to fret about finding a suitable amp for the Senn flagship: the Crack sounds TERRIFIC w/ the HD800.  I've heard the HD800 on a number of well regarded amps.. and, IME, the Crack + SB remains one of the best pairings, regardless of price.



 


+1


----------



## W0lfd0g

defqon said:


> I got over the GEC 6AS7G phase. Good sounding tube but definitely not worth the asking price on ebay nowadays.




To each their own. For some it's cables. For me it's tubes. I hope my GEC brown base phase continues.


----------



## skeptic

flysweep said:


> One the really great things about the Crack + SB is that not only does it sound fantastic with the 600/650, if you're ever inclined to move from the HD6x0 to the HD800.. there's no need to fret about finding a suitable amp for the Senn flagship: the Crack sounds TERRIFIC w/ the HD800.  I've heard the HD800 on a number of well regarded amps.. and, IME, the Crack + SB remains one of the best pairings, regardless of price.


 
  
 +2


----------



## trentrosa

I notice lotsof folks upgrade the capacitors in their crack w/ sb, and was just wondering what the main advantages are and where I could possibly buy some in the future?


----------



## Loquah

w0lfd0g said:


> To each their own. For some it's cables. For me it's tubes. I hope my GEC brown base phase continues.


 
  
 I agree.
  
 And Nathan, you are not just a tube-aholic, but also an enabler for other tube-aholics! I love the 6AS7G brown base you sold me and it sings with my T1s to the point that I desire no other headphone gear at the moment! Yes, that state of peace will pass, but I'm reveling in it for now.
  
 As for Crack plus 6X0 combination, at a recent Melbourne meet, we had HD800, HE-6s, vintage amps, Woo Fireflies, NAD M51 and various other awesome gear, but what stole the show was the Crack with HD650s (no speedball or mods) - it's just a great pairing (with either HD600/650) and for the price it might be unbeatable.


----------



## amcananey

Depending on who you talk to and what caps you replace, the benefits are improved resolution/detail, speed and bass impact. Others claim greater extension up or down the frequency spectrum. Others reduced noise.

There are four places that most people seem to use when sourcing caps (though there are countless others):

1. Madisound (http://www.madisoundspeakerstore.com/capacitors/) - Madisound has a decent selection that covers the most popular caps, low prices (for boutique caps), excellent service and low shipping costs.

2. Parts Connexion (http://www.partsconnexion.com/) - Large selection. Prices are higher than Madisound. Shipping costs tend to be high in my experience (they are located in Canada and shipping from Canada is expensive).

3. Parts Express (http://www.parts-express.com/cat/metalized-polypropylene-capacitors/1382) - Fairly small selection (in terms of brands). They carry the Dayton Audio film caps, which are a good way to try out film caps without dropping the big bucks for boutique caps.

4. eBay - In my experience, eBay is a good source for small-value caps from Russia (teflon and paper-in-oil caps of 0.1uf or less) and large-value film caps for use in the power supply.

Best regards,
Adam


----------



## lugnut

amcananey said:


> Can't say. I didn't find my 12BH7s to be better than my 12AU7s in an un-modified Crack. The Bottlehead guys recommend modding the Crack if you plan on using 12BH7s. I didn't want to get locked into 12BH7s, so I never made the recommended mod to my Crack.


 
  
 I was under the impression that it was safe to use 12BH7s with the Crack with Speedball. Am I correct or wrong ?  Thanks


----------



## DefQon

Thank goodness this ain't diyaudio. 
  
 Cap upgrades, sonic improvements, spec'f ESR and ripple current etc etc can become quite the heated topic almost as much as cables.
  
 Personally for me, I like to drop in good spec'd caps over your typical bog standard Nichicon or Panasonic (FM/FC are great ps/filtering/decoupling) because one it looks good, two it looks good, three it looks good and if I'm hearing it, some sonic improvements but it usually depends. I.e. I find Silmics very warm sounding if used too much in the signal path, KZ's and Silmic and Cerafine's are great mix in the signal path and maybe throw in a few boutique polypropylene caps for decoupling which in most cases give a cleaner sound than many boutique PIO cap. 
  
 I like to go overkill with caps but not to the extent of borderlining stupidity someone here has gone with there Crack LOL (jks 
	

	
	
		
		

		
			





, you know who you are).


----------



## amcananey

I'm sure I have no idea what you're talking about. 

Lugnut, it is safe, it is just not optimal. The 12BH7 changes the operating point of the 6AS7G / 6080 unless you replace the LEDs on the 9-pin socket with resistors.


----------



## W0lfd0g

amcananey said:


> I'm sure I have no idea what you're talking about.
> 
> 
> 
> ...


 
  
 I am a diy newb.  Please explain.  What is the operating point and what sonic effect does it have?


----------



## amcananey

http://vinylsavor.blogspot.com/2011/01/search-for-that-magical-operating-point.html 

But as a reminder, I did NOT make any modifications to my Crack when trying my 12BH7s, so I can't say what (if any) audible difference it would make.

Just so everyone has it (even though I've posted it several times in this thread), here is the source of my comment: http://www.bottlehead.com/smf/index.php/topic,663.msg45199.html#msg45199

Regards,
Adam


----------



## W0lfd0g

Thanks for the link, Adam. Can you please explain it in language that a newb can understand? From the little I read before my head started spinning (think Exorcist) it is the author's opinion that a forgiving amp can be a good thing - ie one that does not require a very tight matching to a theoretically optimal operating point (whatever that is). Is the Crack forgiving? I can only go by what I hear and I love the sound of the E80CC in my Crack (in which I haven't messed around by replacing LEDs with resistors)


----------



## Nowhere

interestingly my grandmother came over last night and i was showing her the amp and she actually loved the way it looked and thought it was something rich people would have out on display because of how vintage it looked and reminded her of her day. i know some talk about how it's not the best looking but i actually love the look of it, it's so oldschool.
  
 she listened to a little of chasing cars by snow patrol and was blown away hehe.


----------



## amcananey

Nathan,

I'm no expert, and I can't say for certain whether the Crack is forgiving or not from a technical perspective, but I would argue that the fact that the Crack sounds good with both 12BH7s and E80CCs indicates that it probably IS a fairly forgiving amp. I've used both 12BH7s and E80CCs and didn't really have any complaints about the sound quality. But since my 12AU7s sound just as good (and some even seem to sound better) and since Bottlehead has made it clear that the stock Crack isn't optimal with the 12BH7 and E80CCs, I've just decided to stick with 12AU7s and their DIRECT equivalents.

Also, FWIW, I don't know whether the E80CC differs at all from the 12BH7. The Bottlehead advice I linked to was specific to the 12BH7. If the E80CC is different, you might need to make different mods to optimize the circuit. (Don't ask me what they are, I'm just as clueless as you are.)



Best regards,
Adam


----------



## W0lfd0g

Thanks Adam.
  
 I'm happy with the sound and that's all that matters.  I'm not going to go messing with the circuit when I also love other driver tube varieties, not least of which is the 7316.
  
 Cheers.


----------



## amcananey

w0lfd0g said:


> I'm happy with the sound and that's all that matters.



 


Sound quality? Since when does that factor into anything?!?!??



Adam


----------



## bala

Folks, can someone send me a copy of the Speedball manual please, the CD was unreadable and I am still waiting for a reply to my email from DocB.


----------



## Loquah

bala said:


> Folks, can someone send me a copy of the Speedball manual please, the CD was unreadable and I am still waiting for a reply to my email from DocB.


 
  
 PM'ed


----------



## bala

Thanks Loquah, looking forward to the speedball upgrade!


----------



## sp3llv3xit

amcananey said:


> Yes, you can just plug in any compatible tube. If you find yourself using any tube other than a 12AU7, ECC82 or 6SN7 (via adapter) regularly as your input tube, you might want to consider some mods in order to optimize the amp for those tube types (e.g., 12BH7 or E80CC), but frankly I don't think it is worth it unless you are sure you will never want to use a 12AU7, ECC82 or 6SN7 again.
> 
> Some people claim there are synergies between certain tube combinations. There may well be, but the added benefit is small and trying to find reliable information on tubes, let alone two specific tubes in combination, is almost impossible. The bottom line is that almost every tube I've tried has sounded good in my Crack.
> 
> ...


 


 You sound like the type of guide or guru who can really be within my sonic preference.  I've got absolutely no love for the 650s.  I had them. Went crazy modding them believing I could make them better.  YOU ARE CORRECT.  *"they are as bad as I remember. I know the HD650s are newer, have a higher number and cost more, but they are still worse than the HD580s/HD600s. Save your cash for something else. If you want an upgrade from the HD600s, save your pennies and buy a pair of HD800s when you can. They are absolutely amazing, especially out of a Crack. Skip the HD650s and HD700s"*
  
 2 months ago, I got my brand new HD800.  I am currently using the WA6-SE to drive it.  Since it is an upgrade to the Burson that I had, I've got nothing better to compare it against.  However, I still feel that the HD800s have more to give given proper amplification.  I have NOT soldered anything in my entire life, would you recommend I get the Bottlehead Crack?  BTW, I also own a Beyerdynamic T1.   At the moment, I am loving the WA6-SE (w/ Sophia rectifier and RCA 6GL7) with the T1 more than its pairing with the 800s.


----------



## whatthedac

sp3llv3xit, I did a lot of research before ordering the Crack.  I consistently came across stories where people with no soldering experience or electronics background were able to successfully build the Crack.  I wouldn't let that be a reason to stop you from getting it.  I don't know if they still do it, but there used to be a way to order the crack pre-built.  I'd recommend doing it yourself.  It'll be fun, give you confidence in modding your Crack (if you ever feel that's necessary), and it's something to be proud of.
  
 Adam seems really passionate about the HD 800 + Crack combo.  I wish he'd do a nationwide tour, so I could try his mods and his higher-end headphones.
  
 Edit:  please note that if you don't have experience soldering, then you likely don't have the equipment.  That'll be an additional, but small, investment -- just a heads up.


----------



## sp3llv3xit

whatthedac said:


> sp3llv3xit, I did a lot of research before ordering the Crack.  I consistently came across stories where people with no soldering experience or electronics background were able to successfully build the Crack.  I wouldn't let that be a reason to stop you from getting it.  I don't know if they still do it, but there used to be a way to order the crack pre-built.  I'd recommend doing it yourself.  It'll be fun, give you confidence in modding your Crack (if you ever feel that's necessary), and it's something to be proud of.
> 
> Adam seems really passionate about the HD 800 + Crack combo.  I wish he'd do a nationwide tour, so I could try his mods and his higher-end headphones.
> 
> Edit:  please note that if you don't have experience soldering, then you likely don't have the equipment.  That'll be an additional, but small, investment -- just a heads up.


 

 Thank you for the pros-cons discourse.  

 I shall certainly read more about the Bottlehead before ordering.  It came late to me that DIY amps though not as visually pleasing as mass produced ones, can more often sound better.  I am using a DIY portable to drive my full-sized as well as my IEMs (after my rounds with the ALO line of amps).


----------



## amcananey

I've never owned a WA6-SE, but I owned a WA6 w/ Princess Sophia and a WA22, with every upgrade tube Woo offers. As soon as I had built my Crack and spent enough time with it to be sure what I was hearing was real, I sold both of them, and have never regretted it for a second. The Crack was so much better than the WA22 with the HD800s that it was embarrassing. 

But don't get me wrong, Woo build quality and aesthetics are awesome. 

FYI, Bottlehead just recently reactivated it's assembly service, only it isn't a Bottlehead service: they have an outside guy they know and trust, and you work directly with him. Crack assembly is $250. See here.here Speedball is an extra $90.

Build it yourself. First, it isn't that hard. Second, you save money. Third, you will be equipped to make your own modifications and upgrades. (Which you will want to do, if for no other reason than its fun.) Fourth, Bottlehead customer support (through their forums) is excellent and very, very fast. Fifth, it will give you the skills and confidence to undertake other DIY projects, which is fun and will save you even more money. Sixth, you can't really break anything meaningful in the Crack. Worst comes to worst, you overheat a part and have to order a replacement, which will probably cost you $1-2. 

Go for it. The Crack is AWESOME with the HD800s. 

Regards,
Adam


----------



## brunk

^^^ Yep. Crack is the perfect gateway DIY drug 
	

	
	
		
		

		
			





 I have six DIY projects in the works now thanks to it...included a back loaded horn project!


----------



## sp3llv3xit

amcananey said:


> I've never owned a WA6-SE, but I owned a WA6 w/ Princess Sophia and a WA22, with every upgrade tube Woo offers. As soon as I had built my Crack and spent enough time with it to be sure what I was hearing was real, I sold both of them, and have never regretted it for a second. The Crack was so much better than the WA22 with the HD800s that it was embarrassing.
> 
> But don't get me wrong, Woo build quality and aesthetics are awesome.
> 
> ...


 

 Thanks!


----------



## DefQon

+1 the HD600+Crack. Just love it, the HD580/600 are definitely more neutral than the 650's. The 650's are nice too but I find they shine better on solid state amps and not tubes. But hey that's just me.


----------



## Loquah

Ditto on the comments about building the Crack even as a novice. I'm currently assisting a novice solderer to build the SEX kit which is harder than the Crack, but we're doing fine. Also, have to 2nd the point that the worst you can do is overheat a part (like I did with one of the little LEDs), but it's a low cost lesson and nothing to be worried about.


----------



## sjeffrey

Doc B, do we get an email when product has shipped? I've been refreshing the delivery status page madly everyday and last update was almost 2 weeks ago. On top of that the crack status was shipped up to the day before my order :/


----------



## amcananey

The kits are packed and shipped in batches. The hold up between batches is usually due to the need to wait for parts to arrive. If you ordered as part of a promotional deal, then there were likely a large number of orders, and it can take a while for the team to work through those.

Best regards,
Adam


----------



## ben_r_

sjeffrey said:


> Doc B, do we get an email when product has shipped? I've been refreshing the delivery status page madly everyday and last update was almost 2 weeks ago. On top of that the crack status was shipped up to the day before my order :/


 
 You do, with the tracking number.


----------



## Doc B.

The next batch of Crack kits is scheduled to ship at the end of this week.


----------



## trentrosa

It may take awhile to ship, however once out of Bottlehead's hands, I got mine very swiftly, 3 or 4 days.


----------



## ngyu

woo hoo! I ordered one, can't wait for it to come in! Picked up a Valab stepped attenuator to go with it too. Gonna be pairing it with my HD650. I also have a Schiit Lyr + Uberfrost, but my HE-500 seems to be hogging it all the time right now =P


----------



## younglee200

Thought I should chime in here.  I ordered the Crack kit + Speedball few weeks back, and completed the initial kit about a week ago.  
 Only problem I have right now with the amp is that it sounds so good that when I have free time, I can't leave these alone which leaves me no time to install the Speedball   I will probably upgrade them this upcoming weekend.
  
I'm selling my SS amplifier counter-part (M^3), because for the Senn 650s, the Crack is that much better.  Other headphones I own and have owned are pale in comparison compared to this combo.  The Crack is probably an end of the road for me as far as Amplifiers go.  I might go for a upgrades in my source and possibly upgrade to the 800s in the future... but for as far as amps go, especially for high impedance phones, this is it.  I don't know how much more I would have to spend to get better sound than this and I probably wouldn't be able to justify its costs.
  
 I'd also like to add on in saying that the Bottlehead Crack is not too difficult of a project.  My DIY experience was limited to cables and such, and mine worked flawlessly the first time I turned it on.  My only advice, is to take your time on it, and to triple check your work.  The whole build took two weekends for me to complete.  It could get a little frustrating, but it's also very fun and rewarding at the same time.  I've had to post on their forum once due to an issue (I lost the fuse), but responses were expeditious and helpful.
  
 I couldn't recommend this amp more to any Senn owners out there.


----------



## Nowhere

Hey guys and gals, quick question... When going for tubes which should receive my priority, for example... Say i have $150 to spend and i'm going to put $100 of it toward one of the tubes and $50 to the other, which tube should get the larger investment, the power tube or the input?


----------



## georgehifi

brunk said:


> I believe the original lightspeed cost around $700.


 
 Hi all, I manufacture the original Lightspeed Attenuator MkII, and some one pointed me to this pricing misquote.
 The Lightspeed Attenuator is $490 aud (Australian Dollars) this is the shipped price world wide.
 For more info email me at georgehifi@Xoptusnet.com.au please delete the X
  
 Cheers George


----------



## W0lfd0g

The output tube (6080/6AS7G/5998 and variants) produces the biggest difference in sound quality IMO, but the best ones aren't cheap.
  
 If you have $150.00 here are my recommendations (in order of preference) :
  
 1. GEC 6AS7G brown base and an RCA 12AU7A clear top.  Others here have tried and loved the combination. 
  
 2. A second option would be a Tung Sol 7236 (computer rated 5998 that sounds tighter/faster), again driven by an RCA cleartop
  
 3. 5998 driven by (you guessed it) RCA clear top
  
 4. Bendix slotted graphite plate 6080WB driven by early 60s Mullard ECC82
  
 The best bang for buck driver tube is the RCA 12AU7 clear top.
  
 Send me a PM if these combinations interest you - I may be able to find some for you in my stockpile


----------



## palmfish

I swore I wouldnt do it, but my curiosity got the best of me and so I just bought a NOS brown base GEC 6AS7G.

I personally cant imagine hearing a difference, but after so many positive comments, I decided to see for myself.


----------



## W0lfd0g

Curiosity can be an expensive habit!


----------



## Loquah

w0lfd0g said:


> The output tube (6080/6AS7G/5998 and variants) produces the biggest difference in sound quality IMO, but the best ones aren't cheap.
> 
> If you have $150.00 here are my recommendations (in order of preference) :
> 
> ...


 
  
 I agree with the Cleartop being great bang for buck. I'm split though on which tube has the most potential impact and would probably call it equal between the 2, meaning that I'd buy the best tube I can with the available budget regardless of whether it's an input or power tube.
  
 Either that, or see if you can pick up 2 good tubes for your money. For example, my previous favourite combo was a Mullard 6080WA paired with the RCA Cleartop 12AU7, all comfortably <$150.
  
 I can recommend chatting with Wolfdog to see what he might have that fits in your budget - his taste in tubes is excellent and he was great to deal with when I purchased from him.


----------



## Nowhere

w0lfd0g said:


> The output tube (6080/6AS7G/5998 and variants) produces the biggest difference in sound quality IMO, but the best ones aren't cheap.
> 
> If you have $150.00 here are my recommendations (in order of preference) :
> 
> ...


 
  
 That sounds great except it won't be right now, i'm sort of doing some recon at the moment in preperation. I'm currently using two rca unmarked tubes that came with my unit but i want to make sure to have a back up plan.
 So... I figure i'll try and buy 2 new decent ones and store these away as a backup if anything happens...but it won't be for weeks.
  
 If you're still around at that time i'll PM ya.


----------



## W0lfd0g

Wise to do your research first.


----------



## silversurfer616

Hi Guys,need some help.
Have just purchased a Crack with SB but have to use it with a stepdown transformer as I live in New Zealand and we are running 240V instead of 110V.
To get the matching transformer I need to know the power rating of the Crack but can't find any info online.
Any ideas?Thanks for your help!:regular_smile :


----------



## W0lfd0g

You know that you can order the crack with a 240 V transformer? It's a few bucks extra, but cheaper than the option you are suggesting.


----------



## silversurfer616

Yes,I know but I just bought one from an american HeadFier which is naturally the US version.


----------



## Loquah

silversurfer616 said:


> Yes,I know but I just bought one from an american HeadFier which is naturally the US version.


 
  
 You could email Bottlehead and just buy the transformer to add to your kit. I'm sure they'd sell it separately.


----------



## silversurfer616

Might do that,thanks!


----------



## Doc B.

We're happy to sell you a 240V power transformer, but the reality is it's kind of a PITA to change out because of the number of things that need to be disconnected and reconnected under the chassis. So a step down transformer might be the easiest approach. A 100VA step down should be ample.


----------



## Aeolus Kratos

palmfish said:


> I swore I wouldnt do it, but my curiosity got the best of me and so I just bought a NOS brown base GEC 6AS7G.
> 
> I personally cant imagine hearing a difference, but after so many positive comments, I decided to see for myself.


 

 Did your GEC arrive? If so, how are the differences between the GEC and your previous power tube?
  
 Looking forward to hearing from you. Because my curiosity is becoming the same as yours


----------



## silversurfer616

​


doc b. said:


> We're happy to sell you a 240V power transformer, but the reality is it's kind of a PITA to change out because of the number of things that need to be disconnected and reconnected under the chassis. So a step down transformer might be the easiest approach. A 100VA step down should be ample.



Thank you,that is exactly what I need to know!


----------



## palmfish

aeolus kratos said:


> Did your GEC arrive? If so, how are the differences between the GEC and your previous power tube?
> 
> Looking forward to hearing from you. Because my curiosity is becoming the same as yours


 
  
 Not yet. Hopefully next week. I'll post my impressions once I have them.


----------



## Loquah

Surfer, I thought you were yet to build it - that you bought the kit, not a completed amp. 

Doc's comments are of course very true (he would know) if it's already built, but if you're building it from scratch then it'll be a piece of cake to change the transformer before you build.


----------



## silversurfer616

Should get the amp Monday and will buy a transforner then.Really excited how the Crack sounds with my HD600/800 and how it compares to the WA6.
Then reading up on tube rolling!!!


----------



## W0lfd0g

Check this out.  6080WB Bendix with slotted graphite plate for $40.00 (presumably used).  Nice tube at a reasonable price.  I have just purchased a pair myself and thought I would give someone else the chance rather than snap it up. 
  
 http://www.ebay.com.au/itm/RARE-Bendix-6080WB-5998-6as7G-Graphite-Plates-tube-Test-Very-Strong-/171131589193?pt=Vintage_Electronics_R2&hash=item27d83cd249
  
 This is not a recommendation for this particular seller or this particular tube (neither of which I know) - Just the tube type.


----------



## brunk

w0lfd0g said:


> Check this out.  6080WB Bendix with slotted graphite plate for $40.00 (presumably used).  Nice tube at a reasonable price.  I have just purchased a pair myself and thought I would give someone else the chance rather than snap it up.
> 
> http://www.ebay.com.au/itm/RARE-Bendix-6080WB-5998-6as7G-Graphite-Plates-tube-Test-Very-Strong-/171131589193?pt=Vintage_Electronics_R2&hash=item27d83cd249
> 
> This is not a recommendation for this particular seller or this particular tube (neither of which I know) - Just the tube type.


 
  
 I snatched it up 
	

	
	
		
		

		
		
	


	




 Thanks!


----------



## W0lfd0g

I have one NOS 6AS7G GEC straight brown base available if anyone is interested. $150 and I will include an RCA clear top 12AU7 (White box). Will post tomorrow (Monday). Send me a PM if interested Shipping via registered post is about $25 worldwide. Selling at cost to give others the chance to hear it - Don't want to be a hog.

Keeping my remaining two brown bases for my Crack, though. They will need to be prised from my cold, dead hands.

Cheers


----------



## brunk

w0lfd0g said:


> I have one NOS 6AS7G GEC straight brown base available if anyone is interested. $150 and I will include an RCA clear top 12AU7 (White box). Will post tomorrow (Monday). Send me a PM if interested Shipping via registered post is about $25 worldwide. Selling at cost to give others the chance to hear it - Don't want to be a hog.
> 
> Keeping my remaining two brown bases for my Crack, though. They will need to be prised from my cold, dead hands.
> 
> Cheers


 
  
 Have you tested it by chance?


----------



## W0lfd0g

Yep - Tested in my recently calibrated Precision Instruments Emission tester and in my Crack. NOS, tests strong (as expected for new tube), no microphonic behaviour and hum free.  In government brown box. 
  
 Already sold though, sorry brunk.  Will let you know if it falls through.
  
 Enjoy your tubes everyone, but remember that they are just tinting on the window to the music.


----------



## W0lfd0g

Fell through - Would-be buyer realised he had other commitments. 
  
 My apologies everyone.  Didn't mean to derail the thread.
  
 Now... back to our regular program


----------



## Aeolus Kratos

Hello everyone,
  
 After a pretty long time working fine, my speedballed crack started to have some little problems. When I turned the Crack on today, the tubes did not light up, then I slipped my Crack to see underneath, all the LEDs did not light up too ( that means there were no electricity in the Crack ), even though I pressed the power switch. I changed different power cords but could not help. I swapped the tubes, still did not work. Then I slipped the plate again, did not forget wearing shoes to avoid electric shock. I tried to touch and move the connector pins of the driver tube underneath the plate, then suddenly I was shocked and let the plate fall back to the wood base. But magically, the LEDs and the tubes lighted up again, and the Crack worked perfectly ever since.
  
 I actually have no idea if there are some problems with the transformer or the joints.
  
 Any idea?
  
 Sorry for my bad English, I was trying to describe what happened to me.
  
 Best regards,
 Kratos.


----------



## brunk

aeolus kratos said:


> Hello everyone,
> 
> After a pretty long time working fine, my speedballed crack started to have some little problems. When I turned the Crack on today, the tubes did not light up, then I slipped my Crack to see underneath, all the LEDs did not light up too ( that means there were no electricity in the Crack ), even though I pressed the power switch. I changed different power cords but could not help. I swapped the tubes, still did not work. Then I slipped the plate again, did not forget wearing shoes to avoid electric shock. I tried to touch and move the connector pins of the driver tube underneath the plate, then suddenly I was shocked and let the plate fall back to the wood base. But magically, the LEDs and the tubes lighted up again, and the Crack worked perfectly ever since.
> 
> ...


 
  
 Sounds like there's a bad solder joint at that connection and you happened to push it back in contact. If it gives you problems again, i would suck out the old solder and redo it with new solder. Glad to see you're okay, but i bet that gave you a good scare!


----------



## amcananey

Sounds like you have some bad solder joints. I would reheat them and add a touch of solder.


----------



## palmfish

w0lfd0g said:


> Fell through - Would-be buyer realised he had other commitments.
> 
> My apologies everyone.  Didn't mean to derail the thread.
> 
> Now... back to our regular program




I wish I had known you had one before I bought mine. I paid about $150 for it but would definitely prefer to deal with a fellow head-fier every time. Thanks for offering - someone should take advantage of your offer for two exceptional tubes at a very fair price!


----------



## W0lfd0g

It was me Palmfish via my eBay store! Posted this morning. Please let me know how you enjoy it.

Cheers

Nathan


----------



## palmfish

w0lfd0g said:


> It was me Palmfish via my eBay store! Posted this morning. Please let me know how you enjoy it.
> 
> Cheers
> 
> Nathan




Oh! I assumed you are in the UK.

I bought mine last Thursday from "arnold_rimmer" in Australia.


----------



## Loquah

w0lfd0g said:


> It was me Palmfish via my eBay store! Posted this morning. Please let me know how you enjoy it.
> 
> Cheers
> 
> Nathan


 
  
 It's like you're everywhere! An omnipresent source of tubey goodness!


----------



## W0lfd0g

Quote: 





palmfish said:


> Oh! I assumed you are in the UK.
> 
> I bought mine last Thursday from "arnold_rimmer" in Australia.


 
  
  
 That's me! The GEC brown bases are all gone (except for the one I am keeping for myself.  Hands off!)


----------



## Aeolus Kratos

w0lfd0g said:


> That's me! The GEC brown bases are all gone (except for the one I am keeping for myself.  Hands off!)


 
 And now I'm eagerly waiting for my arriving GEC Brown base 
	

	
	
		
		

		
		
	


	



  
 Thank you so much Nathan!


----------



## palmfish

w0lfd0g said:


> That's me! The GEC brown bases are all gone (except for the one I am keeping for myself.  Hands off!)




Well done! Im glad to know that Nathan. 

The Douglas Adams reference threw me off the scent...


----------



## W0lfd0g

I am selling off 95% of my Crack tubes in the form of sample packs.  Not trying to turn a profit, just distribute my stash to those who can put its constituent parts to good use. 
  
 Four options: $30.00 sample pack, $60.00 sample pack, $90.00 sample pack and $150.00 sample pack.  The goal is to give people some tube rolling options at a variety of budget levels.  A way in without investing too heavily. 
  
 http://www.head-fi.org/t/682754/tube-rolling-fest-for-crack-owners
  
 If you do not think this post is appropriate advertising I am happy to remove it immediately.
  
 Cheers
  




  
 Nathan


----------



## Loquah

Crap! I think my newly completed SEX just made my Crack obsolete!
  
 Anyone here have / had both and care to comment on your thoughts. Are there times you would choose to return to the Crack over the SEX?
  
 I should add that the Crack has the Speedball and I run it with the GEC 6AS7 brown base (straight) and RCA Cleartop 12AU7 so it's about as good as a Crack can get, but the SEX just seems to have the edge in higher frequency timbre and presentation as well as overall transparency. The Crack might still have the edge in midrange thanks to the GEC tube.


----------



## gikigill

I told you so!


----------



## W0lfd0g

And the Mainline will make the SEX a dust collector....
  
 It never ends!  I'm blocking my ears and covering my eyes.


----------



## Loquah

gikigill said:


> I told you so!


 
  
 I know, but I really didn't want to believe that after pouring so much love (and $$$) into the Crack...


----------



## brunk

loquah said:


> I know, but I really didn't want to believe that after pouring so much love (and $$$) into the Crack...


 
  
 SEX is a SET amp right?


----------



## Aeolus Kratos

w0lfd0g said:


> And the Mainline will make the SEX a dust collector....
> 
> It never ends!  I'm blocking my ears and covering my eyes.


 
 Well said!


----------



## Loquah

brunk said:


> SEX is a SET amp right?


 
  
 That's correct. It's very transparent, clean and offers extremely nice, large, but coherent soundstage. A slight hum is audible when the music is silent, but I expect the C4S upgrade will sort that out.


----------



## Zashoomin

loquah said:


> Crap! I think my newly completed SEX just made my Crack obsolete!
> 
> Anyone here have / had both and care to comment on your thoughts. Are there times you would choose to return to the Crack over the SEX?
> 
> I should add that the Crack has the Speedball and I run it with the GEC 6AS7 brown base (straight) and RCA Cleartop 12AU7 so it's about as good as a Crack can get, but the SEX just seems to have the edge in higher frequency timbre and presentation as well as overall transparency. The Crack might still have the edge in midrange thanks to the GEC tube.


 
  
 I own the sex and honestly it is fantastic.  If you get the C4S upgrade it will be even better and with the impedence switches it is even more convinient.  It also drives everything from low impedence to high impedence phones wonderfully.  Also the best part is I can't tube roll it.  I know it sounds strange but if I don't have a choice I can't spend money.  On the other hand finding a matched pair is a pain in the butt.  But overall I love my sex.  It sounds fantastic with my LCD2's.


----------



## Zashoomin

loquah said:


> That's correct. It's very transparent, clean and offers extremely nice, large, but coherent soundstage. A slight hum is audible when the music is silent, but I expect the C4S upgrade will sort that out.


 
  
 Even with the C4S upgrade there will still be a little hum.  I mean it isn't noticable when music is playing but if nothing is going on it is definately there.


----------



## Loquah

zashoomin said:


> I own the sex and honestly it is fantastic.  If you get the C4S upgrade it will be even better and with the impedence switches it is even more convinient.  It also drives everything from low impedence to high impedence phones wonderfully.  Also the best part is I can't tube roll it.  I know it sounds strange but if I don't have a choice I can't spend money.  On the other hand finding a matched pair is a pain in the butt.  But overall I love my sex.  It sounds fantastic with my LCD2's.


 
  
 I know what you mean. I thought I'd be bummed about that, but it's kind of nice to know that it's already as good as it gets (which is darn good).
  
 Do you have the Crack too? And do you still use it over the SEX? If so, for what cans / music?


----------



## Zashoomin

loquah said:


> I know what you mean. I thought I'd be bummed about that, but it's kind of nice to know that it's already as good as it gets (which is darn good).
> 
> Do you have the Crack too? And do you still use it over the SEX? If so, for what cans / music?


 
  
 I used to have a crack that I used to use with some dt800 600s but now I have lcd2 and 3's so I figured that the crack couldn't drive them (trust me I tried).  Honestly that hiss kinda bugs me so I am thinking about the mainline but other than that everything sounds fantastic.  Everyone talks about how good the certain amps are with the lcd2's but I think that the SEX definately should be one that is mentioned.  If you are asking if I like the dt880s better with the crack or sex. I don't remember sorry.  
  
 Edit: I listen to everything and anything mostly things that aren't mainstream but I thought that especially with songs that aren't as busy the SEX shines.


----------



## W0lfd0g

Hey you two...yes Loquah and Zashoomin - I'm lookingat you.  Take all your dirty SEX talk to a suitable thread and leave us kids here playing with Crack to our innocent pleasures.


----------



## W0lfd0g

Actually, Lachlan, it's good to hear some comparisons. It would be great to read a side by side comparison of the Crack, the SEX and the Mainline to determine what differences each bring to the table, the value factor and which headphones work best with each. Any volunteers?


----------



## Loquah

Yes, hand up from me!

First step is a Crack / SEX comparison and then the Mainline later. I'll likely sell the Crack to help fund the Mainline purchase. 

There currently isn't a SEX thread. Would you guys prefer to let this thread go all things Bottlehead (Crack, SEX and Mainline) or keep it Crack only?


----------



## Zashoomin

Well as long as there is some crack reference it should be fine.  and I plan on doing a comparison but I might have to borrow someone's crack for it since I currently don't have one.  But it will happen as soon as I gather the funds for the mainline.


----------



## W0lfd0g

1. I think that there should be a dedicated SEX thread. 
2. Lachlan, you could create your review as the first post of an all things Bottlehead review, reserving the first five posts.
A. Crack
B. Sex
C. Mainline
D. Summary comparison of amps
E. Bottlehead DAC

Lachlan, perhaps you could approach Doc with the idea to see if he would send you a review sample to build. I suggest you provide him with a link to your blog to show your writing quality and style. It would be good if you had all three amps at the same time to compare as auditory memory is a fickle thing.

Cheers and thanks. I look forward to something like this with pleasure.


----------



## W0lfd0g

Perhaps you two could collaborate.


----------



## Zashoomin

w0lfd0g said:


> Perhaps you two could collaborate.


 
  


w0lfd0g said:


> 1. I think that there should be a dedicated SEX thread.
> 2. Lachlan, you could create your review as the first post of an all things Bottlehead review, reserving the first five posts.
> A. Crack
> B. Sex
> ...


 
  
 That sounds fantastic.  I would love to build the mainline or any of the other ones as honestly I think the most fun thing about bottlehead stuff is the opertunity to build and customize whatever kit I can get my hands on.  also reviewing everything would be an amazing chance as well.  Loquah, I would love to work with you on this.


----------



## brunk

All this Bottlehead talk is making me hungry...


----------



## Loquah

w0lfd0g said:


> 1. I think that there should be a dedicated SEX thread.
> 2. Lachlan, you could create your review as the first post of an all things Bottlehead review, reserving the first five posts.
> A. Crack
> B. Sex
> ...


 
  
 Good points, Wolfdog. I've emailed Doc.
  
 Currently reviewing the Beyer T1s (via the SEX and Crack) and will move onto my Crack vs SEX review this weekend.
  
 Early impressions give the bass and mids slightly to the Crack in terms of weight and volume of bass, plus smoothness of presentation. The SEX has the edge in staging and separation / transparency. Both are outstanding anyway you look at them.


----------



## Zashoomin

loquah said:


> Good points, Wolfdog. I've emailed Doc.
> 
> Currently reviewing the Beyer T1s (via the SEX and Crack) and will move onto my Crack vs SEX review this weekend.
> 
> Early impressions give the bass and mids slightly to the Crack in terms of weight and volume of bass, plus smoothness of presentation. The SEX has the edge in staging and separation / transparency. Both are outstanding anyway you look at them.


 
  
 I don't know if that is a fair comparison as I think that the SEX excels in driving lower impedence phones and the crack higher but if that is the case than I don't know what a fair comparison would be.  Ignore my ramblings just a thought.


----------



## Loquah

zashoomin said:


> I don't know if that is a fair comparison as I think that the SEX excels in driving lower impedence phones and the crack higher but if that is the case than I don't know what a fair comparison would be.  Ignore my ramblings just a thought.


 
  
 I'm currently driving 600ohm T1s from the SEX and loving it. My fiancee prefers the Crack with the T1s, but I prefer the SEX - the beauty of preference and opinion in audio!
  
 I wonder if the Crack is a dedicated high impedance headphone amp more because the price dictates the design which results in a high output impedance and therefore a need for high impedance loads? The price of the SEX might allow for more components to better balance different possible loads.
  
 I think the Crack is the best thing you can buy for <$400 (or maybe even higher) to drive high impedance headphones whereas the SEX is just a great amp with whatever you pair it with (low or high impedance), but also nearly twice the price of the Crack!


----------



## amcananey

Yes and no. The Crack is an output transformerless (OTL) tube amp. Without an output transformer, you will have high output impedance, which is why the Crack isn't well-suited to use with low impedance headphones. Is this a cost issue? Not really. While it is true that an OTL design can be cheaper, because a good output transformer is expensive, the reason to go for an OTL design isn't really about avoiding the cost of the output transformer, it's about avoiding the output transformer itself! Transformers, even very good ones, create problems. And very good output transformers are quite expensive. If your headphones are high impedance headphones, then the cheapest AND best-sounding option is often to go with an OTL design. There is an excellent article that describes the various problems created by output transformers (it is a fascinating read), but unfortunately...I can't find it right now. I'll keep looking.


----------



## amcananey

Here it is: http://www.hificollective.co.uk/pdf/otl_head.pdf

Great article. Highly recommended.


----------



## brunk

amcananey said:


> Here it is: http://www.hificollective.co.uk/pdf/otl_head.pdf
> 
> Great article. Highly recommended.


 
  
 wow great article


----------



## whatthedac

Yeah, thanks for sharing that.  I've been looking for something like that.  I think the learning process is what makes the DYI route fun.
  
 Also, does anyone know if the Crack shipment went out last Friday?  Doc B. mentioned it in the forum, but I didn't get any emails from Bottlehead.  And queen doesn't seem to be replying.  I'm wondering if mentioning "Crack" in my emails is causing them to go to her spam.


----------



## brunk

whatthedac said:


> Yeah, thanks for sharing that.  I've been looking for something like that.  I think the learning process is what makes the DYI route fun.
> 
> Also, does anyone know if the Crack shipment went out last Friday?  Doc B. mentioned it in the forum, but I didn't get any emails from Bottlehead.  And queen doesn't seem to be replying.  I'm wondering if mentioning "Crack" in my emails is causing them to go to her spam.


 
  
 You will receive an automatic message of your tracking number when they print out your label.


----------



## Doc B.

Wow, this thread got kinda busy yesterday. Let me try to address some of the comments.
  
 Re: hum from the SEX amp - use a lower impedance tap. Sensitive headphones can pick up some hum at the 32 ohm tap. That hum will be reduced greatly at the 8 ohm tap, and you will still have more than enough power. 
  
 Re: separate threads - Probably a good idea as this thread is already over 2700 posts. If started, someone please hip me to it so I can subscribe and be ready to answer questions.
  
 Re: Mainline sample - I will read the reviews and certainly give it consideration. There is one thing that is terribly important about a review of one of our products -  the review must be of a stock kit with no mods. It is pointless to review something other than the exact kit we send out. That of course doesn't include cosmetics. But no $50 caps, no $250 attenuators, etc.  If there is to be a comparison of all three kits, this of course would hold true for all three kits.
  
 Re shipping: We get a large number of orders for Crack kits and because of this we typically run about 4-5 weeks delivery. I have attempted to put that in obvious places on our web site. We got a particularly large number of orders last month due to a sale and because of this delivery might run a bit more than 4-5 weeks. We did ship a lot of kits last week, and we will be shipping more later this week. We have a large order of wood bases that will not arrive until Oct. 1st, and that will influence the timing of shipment of quite a few of the more recent orders. I'm sorry that I don't know specifics of individual orders, that is not my bailiwick. I can say that Crack kits are worked on every day here, just to keep up the flow.


----------



## Zashoomin

doc b. said:


> Re: hum from the SEX amp - use a lower impedance tap. Sensitive headphones can pick up some hum at the 32 ohm tap. That hum will be reduced greatly at the 8 ohm tap, and you will still have more than enough power.
> 
> Re: separate threads - Probably a good idea as this thread is already over 2700 posts. If started, someone please hip me to it so I can subscribe and be ready to answer questions.
> 
> Re: Mainline sample - I will read the reviews and certainly give it consideration. There is one thing that is terribly important about a review of one of our products -  the review must be of a stock kit with no mods. It is pointless to review something other than the exact kit we send out. That of course doesn't include cosmetics. But no $50 caps, no $250 attenuators, etc.  If there is to be a comparison of all three kits, this of course would hold true for all three kits.


 
 Doc I am using LCD 2 and 3 would turning the impedence switches down work for those as well?
  
 Ya the SEX that I have is modded way too much than.


----------



## amcananey

Setting your SEX for a lower output impedance will work fine with the LCD 2 and 3. The higher output impedance settings just increase the power available when using high impedance headphones. If you can get loud enough at a lower impedance setting, even when using your HD600s, then just leave the amp on the lower setting. I forget the exact number, but I think the LCD-2s are 32 Ohm, so I would certainly try one of the lower impedance settings with those...


----------



## amcananey

[Comment deleted. I meant to post in the HD600 thread. Sorry for any confusion.]


----------



## Loquah

amcananey said:


> Here it is: http://www.hificollective.co.uk/pdf/otl_head.pdf
> 
> Great article. Highly recommended.




Thanks for the article Adam. I'll have a read on the train today. 

Also, to clarify, I wasn't suggesting Crack is what it is just to be cheap. My point was basically what you said only not as well expressed. I was guessing that both price and performance were involved and that the Crack represents a great option for high impedance cans at a low pricepoint. At the same time, the need for output transformers with lower impedance loads means a higher starting price for a good sound with a wider range of loads. You said it beautifully.


----------



## amcananey

[Comment deleted. I meant to post in the HD600 thread. Sorry for any confusion.]


----------



## Loquah

doc b. said:


> Wow, this thread got kinda busy yesterday. Let me try to address some of the comments.
> 
> Re: separate threads - Probably a good idea as this thread is already over 2700 posts. If started, someone please hip me to it so I can subscribe and be ready to answer questions.
> 
> Re: Mainline sample - I will read the reviews and certainly give it consideration. There is one thing that is terribly important about a review of one of our products -  the review must be of a stock kit with no mods. It is pointless to review something other than the exact kit we send out. That of course doesn't include cosmetics. But no $50 caps, no $250 attenuators, etc.  If there is to be a comparison of all three kits, this of course would hold true for all three kits.




I'm very happy to start a new Bottlehead thread this weekend, beginning with reviews of the Crack and SEX. I'll post a link here as soon as it's done. 

Doc, I currently have both of the above kits in 100% stock configuration and began without Speedball or C4S before adding the Speedball (C4S to come). As per my email I'd be honoured if we could come to an arrangement regarding the Mainline.


----------



## Loquah

I had a few moments while I baked some bread (yes, literally) so I've created the thread. Updates to follow ASAP.
  
 http://www.head-fi.org/t/683012/bottlehead-amplifier-discussion-comparison-thread-crack-sex-mainline


----------



## W0lfd0g

Brilliant!  Can't wait to read your results.


----------



## HPiper

I have heard it said that the Bottlehead Crack is the best amp you can get for the HD600/650 (or at least one of the best) As I already have both of those phones and am planning to upgrade, would the same also be true of the HD700 and 800, or is there something about those that causes the Crack amp some problems? I was going to get a Lyr but the more I think about it, the more I think it would be fun just to build my own, plus Bottlehead is just across the water from me so I can go yell at em if it doesn't work out


----------



## Loquah

hpiper said:


> I have heard it said that the Bottlehead Crack is the best amp you can get for the HD600/650 (or at least one of the best) As I already have both of those phones and am planning to upgrade, would the same also be true of the HD700 and 800, or is there something about those that causes the Crack amp some problems? I was going to get a Lyr but the more I think about it, the more I think it would be fun just to build my own, plus Bottlehead is just across the water from me so I can go yell at em if it doesn't work out


 
  
 I have briefly tried the HD800 with the Crack and it sounds great (and that was pre-Speedball and pre-GEC brown base tube). From all reports, it's a great option for the price and up to about $1000. I know a fellow Head-Fier that owns and prefers the Woo Fireflies over the Crack (setup as described above), but to me it was more a personal taste thing and the Fireflies cost <$1000. I believe the additional performance brought by the Speedball and right choice of tubes would make it neck-and-neck or even go in the Crack's favour.


----------



## amcananey

If you search this thread, you will find my thoughts on this subject (repeated more often than many people would like). I find the Crack to be the best amp I've tried with my HD800s, and that includes amps that cost up to about $2,500 with tubes. Have I tried all amps below $2,500? No, but I have tried a fair number of amps in the $1,000-2,000 range and I still like the Crack the best. Some of those $1,000-2,000 amps I still own, because they are very good with other headphones, but aren't ideal with the Sennheiser HD600/650/800 or high impedance Beyers and AKGs, where the Crack really excels. And with all of my gear (check my profile), I do 95% of my listening with my HD800s and the Crack.

The one thing I would note is that the HD700s are 150 Ohm, which is really on the border of Bottlehead's recommendations (I think the Crack is recommended for cans over 120 Ohms). In any case, I would recommend either the HD600s or the HD800s over the HD700s. The HD700s were the most comfortable cans I've ever tried, but the HD800s over significantly better performance, while the HD600s offer comparable (I actually preferred the HD600s) performance at a much lower cost.

Best regards,
Adam


----------



## silversurfer616

Have the HD600/800 with the Crack and it certainly beats the Phoenix(balanced)and the WA6 which I had at the same time/before.


----------



## Loquah

Good point regarding the HD700s, Adam. I didn't realise they were 150ohm. I haven't heard them, but I would expect less-than-ideal performance pairing the HD700s with the Crack based on my experiences with other <300ohm headphones. To my ears there's just not enough damping of the bass with such a small gap between output impedance and headphone impedance and the sound gets loose and flabby with the the sub-300ohm cans I've tried.


----------



## palmfish

loquah said:


> I have briefly tried the HD800 with the Crack and it sounds great (and that was pre-Speedball and pre-GEC brown base tube). From all reports, it's a great option for the price and up to about $1000. I know a fellow Head-Fier that owns and prefers the Woo Fireflies over the Crack (setup as described above), but to me it was more a personal taste thing and the Fireflies cost <$1000. I believe the additional performance brought by the Speedball and right choice of tubes would make it neck-and-neck or even go in the Crack's favour.




I have tried the Fireflies several times with my HD800 (in my home and at a friend's house). I wasnt impressed. There was nothing wrong with it, but it just didnt do anything special - basically sounded like what any well designed, competent, uncolored solid state amp would sound like. In other words, like nothing.

IMO, with the Fireflies, you are paying a premium for form over function. With the Crack, while hardly neutral sounding, you are getting an amp with the ideal coloration for the high impedance Sennheisers. The fact that its so affordable is simply icing on the cake.


----------



## olegausany

I'm currently using Crack with Speedball which I bought freshly assembled from a member at for sale forum. I'm using KEN-RAD 6SN7/VT231 also labeled JAN-CKR  which I got from EBay where seller stating they manufactured 1944-1945 plus Chatham 5998 labeled 2399 which I got from a member as local NYC pickup and this combo drives HD700 really great but not better Than Lyr with 6N1P so I don't if getting are more expensive replacement of 6080 tube will give better performance. I also really interested to hear HD800 and T1 with both amps


----------



## Nic Rhodes

The issue is not with the tubes but the impedance of the 700. 700 is not a great performer on the Crack because of the too low impedance, 800 and T1 however are.


----------



## Zashoomin

nic rhodes said:


> The issue is not with the tubes but the impedance of the 700. 700 is not a great performer on the Crack because of the too low impedance, 800 and T1 however are.


 
  
 I would honestly just skip the HD700s and buy the HD800s getting rid of the "should I buy a crack problem"


----------



## amcananey

zashoomin said:


> I would honestly just skip the HD700s and buy the HD800s getting rid of the "should I buy a crack problem" :tongue_smile:




I honestly agree. The HD700s are too expensive for what they are. The HD800s cost more, but are amazing. The fact that they pair incredibly well with a cheap amp helps mitigate the cost of the cans themselves.


----------



## Loquah

amcananey said:


> I honestly agree. The HD700s are too expensive for what they are. The HD800s cost more, but are amazing. The fact that they pair incredibly well with a cheap amp helps mitigate the cost of the cans themselves.


 
  
 That's a really good point about the price pairing with the Crack. I'd never thought of that before.


----------



## mithrandir38

Well, I ditched my Fidelio X1's for being more "veiled" than the infamous 650's (which I now own), and just ordered my Crack today.  It's gonna be a seriously rough month of waiting...


----------



## Loquah

mithrandir38 said:


> Well, I ditched my Fidelio X1's for being more "veiled" than the infamous 650's (which I now own), and just ordered my Crack today.  It's gonna be a seriously rough month of waiting...


 
  
 I've called in some support to help you through this difficult time, mithrandir
  
 http://www.head-fi.org/t/683752/head-fi-gear-separation-support-thread/15#post_9847236
  
 It's a great (and funny) support thread for all those waiting for or living without their gear


----------



## kozmos

Any usb Dac recommendations for my bottlehead crack?
 I don't really wanna pay more than 300$


----------



## FlySweep

kozmos said:


> Any usb Dac recommendations for my bottlehead crack?
> I don't really wanna pay more than 300$


 
  
 W/ my BH Crack, I prefer a DACs that's very transparent.. since the Crack/tube will add it's own gentle coloration to the sound.  Under $300?  If you don't need SPDIF/optical, I'd recommend the ODAC... Stoner Acoustics just came out with the successor to the immensely successful UD100, the UD110 (which has asynchronous USB and does 32-bit hi-res).  There's also the forthcoming Light Harmonic GEEK (which has a pre-order sale going now, I think).  They've got a very good reputation with their TOTL, cost-no-object "Da Vinci" DAC, so many are excited to see what they bring to the table in their very affordable GEEK DAC/amp.


----------



## olegausany

What you guys think about Sovtek 6AS7 annd compare to 5998?


----------



## palmfish

Look what came in the mail today...
  

  
 GEC 6AS7G Brown Base care of Nathan!


----------



## Loquah

palmfish said:


> Look what came in the mail today...
> 
> 
> 
> GEC 6AS7G Brown Base care of Nathan!


 
  
 So it's safe to say you're in a happy place now then! That would be a great pairing with the HD800s. What input tube is that? Cleartop?


----------



## palmfish

My input tube is a CBS 5814A Black Plate

What I have found is that it's almost impossible to compare tubes because of the time it takes to swap them and let them warm up. But so far, with only a couple of hours of play/listening, I can't tell the difference between the GEC, my CBS Hytron 6AS7G, or the original 6080 that came with my Crack. I will say the GEC is significantly better than the 6080 in microphonics though (and equal to the CBS Hytron). 

I'll give it more time, but my first impression is that either the GEC is highly over-rated or the CBS Hytron is an undiscovered gem.

BTW, today is the first day I have listened to music in over 2 weeks due to travel and ear fatigue. I've been listening to k.d. Lang "Ingenue" and man oh man thie Crack/HD800 sounds so sweet. One of the best combinations Ive ever heard. To be cliche, it really is just a musical, fun, organic sound quality. I really can't imagine the Speedball (or anything else) improving it.


----------



## palmfish

Here are the GEC and CBS tubes side by side. It's hard to tell, but the CBS is almost 1/4" taller than the GEC and has a silver painted top. Im not sure what all that extra stuff in the top is...

  
 And here is the CBS in action. I primarily bought the CBS Hytron just for looks...lol. It's a really good-looking tube! Here's a better look at the insides (especially the top section)...


----------



## W0lfd0g

Sorry to hear that, Palmfish. I hoped that you would enjoy it and would hear a difference. Perhaps someone else would like to take a near NOS GEC brown base off your hands.


----------



## Loquah

palmfish said:


> My input tube is a CBS 5814A Black Plate
> 
> What I have found is that it's almost impossible to compare tubes because of the time it takes to swap them and let them warm up. But so far, with only a couple of hours of play/listening, I can't tell the difference between the GEC, my CBS Hytron 6AS7G, or the original 6080 that came with my Crack. I will say the GEC is significantly better than the 6080 in microphonics though (and equal to the CBS Hytron).
> 
> ...


 
  
 Interesting.
  
 I have no doubt that the GEC is better than the standard 6080s, but it's in the subtleties rather than an in-your-face difference like going from low-end headphones to hi-end headphones.
  
 It'll be interesting if you can test the CBS vs GEC once you get used to the GEC. My preferred method (given the swap over delay you mentioned) is to cue up a good 2-3 song playlist and play it in full through one tube and then the other. After hearing the playlist on both tubes I just decide which renditions I preferred overall because it's all about enjoyment in the end.
  
 I should add that I find it needs to be tracks I'm familiar with or I "discover" the songs with the first tube and am bored of them with the second tube. It gives an unfair advantage to whichever tube goes first.


----------



## palmfish

w0lfd0g said:


> Sorry to hear that, Palmfish. I hoped that you would enjoy it and would hear a difference. Perhaps someone else would like to take a near NOS GEC brown base off your hands.




No need to feel that way W0lfd0g. I literally plugged it in only 2 hours ago. Let me give it some quality time with a variety of music and get to know it better before I come to a firm conclusion.

I must admit Im really curious about my CBS now...

Loquah, I hear what you're saying, but in my experience, audio memory is very fleeting. I can only concentrate on one thing at a time when Im listening (critically), and the subtleties are gone from my memory within a few fleeting moments - long before the tube is swapped and warmed up and the music cued up again. Your method just doesnt work for me.


----------



## Loquah

palmfish said:


> Loquah, I hear what you're saying, but in my experience, audio memory is very fleeting. I can only concentrate on one thing at a time when Im listening (critically), and the subtleties are gone from my memory within a few fleeting moments - long before the tube is swapped and warmed up and the music cued up again. Your method just doesnt work for me.


 
  
 Fair point. I may have been mixing my messages. When I spoke about the testing method, I wasn't talking about listening for specific differences because I agree with you that it can be really challenging. My point with the testing method was more a case of long term use of both tubes and then seeing which one you gravitate towards at the end of the testing period.
  
 I often use the same approach with IEM cables to work out what I enjoy more. I don't always understand why I prefer one over the other, but I almost always find a definite preference.
  
 Of course, this method is very open to the influence of things like aesthetic preferences, but that's OK - if you like A better than B, then go with A regardless of why - so long as we find what makes us happy, that's all that matters.


----------



## palmfish

loquah said:


> Fair point. I may have been mixing my messages. When I spoke about the testing method, I wasn't talking about listening for specific differences because I agree with you that it can be really challenging. My point with the testing method was more a case of long term use of both tubes and then seeing which one you gravitate towards at the end of the testing period.
> 
> I often use the same approach with IEM cables to work out what I enjoy more. I don't always understand why I prefer one over the other, but I almost always find a definite preference.
> 
> Of course, this method is very open to the influence of things like aesthetic preferences, but that's OK - if you like A better than B, then go with A regardless of why - so long as we find what makes us happy, that's all that matters.




I see your point. 

Trouble is its also influenced by expectation bias and without volume matching, the louder one will sound better. And once you decide one sounds better, thats it...


----------



## Loquah

palmfish said:


> I see your point.
> 
> Trouble is its also influenced by expectation bias and without volume matching, the louder one will sound better. And once you decide one sounds better, thats it...


 
  
 Very true. It's an inexact science at best


----------



## palmfish

Thats when I tell myself to relax and just enjoy the music


----------



## W0lfd0g

You can measure a signal - You can't measure pleasure.  Enjoy!


----------



## palmfish

I am Nathan! 

Already got through Daft Punk. Now listening to Dishwalla.

I would say I love my Crack, but I could lose my job (not that Im getting paid anyways after today...:rolleyes


----------



## amcananey

palmfish said:


> What I have found is that it's almost impossible to compare tubes because of the time it takes to swap them and let them warm up. But so far, with only a couple of hours of play/listening, I can't tell the difference between the GEC, my CBS Hytron 6AS7G, or the original 6080 that came with my Crack. I will say the GEC is significantly better than the 6080 in microphonics though (and equal to the CBS Hytron).
> 
> I'll give it more time, but my first impression is that either the GEC is highly over-rated or the CBS Hytron is an undiscovered gem.




1. I agree about comparing tubes. For me it is virtually impossible, for the exact reasons you mentioned. Not to mention the need to let tubes COOL before removing them...

2. I agree about the GEC. I've basically stuck with mine because it is low noise and not microphonic, not because it reproduces tones in a way that is appreciably different from my other tubes. 

3. Crack + HD800 is indeed amazing. But the Speedball does indeed improve things. And, in my case, I felt that upgrading the power supply caps also improved things, particularly the bass.

Best regards,
Adam


----------



## Aeolus Kratos

palmfish said:


> I am Nathan!
> 
> Already got through Daft Punk. Now listening to Dishwalla.
> 
> ...


 
  
 Let's see how I would feel about my upcoming GEC


----------



## HPiper

amcananey said:


> 1. I agree about comparing tubes. For me it is virtually impossible, for the exact reasons you mentioned. Not to mention the need to let tubes COOL before removing them...
> 
> 2. I agree about the GEC. I've basically stuck with mine because it is low noise and not microphonic, not because it reproduces tones in a way that is appreciably different from my other tubes.
> 
> ...


 
 I am assuming you would replace the existing caps with others of the same value. Question is how does that improve the sound, what does one cap (of the same value) do better than another?


----------



## palmfish

amcananey said:


> 1. I agree about comparing tubes. For me it is virtually impossible, for the exact reasons you mentioned. Not to mention the need to let tubes COOL before removing them...
> 
> 2. I agree about the GEC. I've basically stuck with mine because it is low noise and not microphonic, not because it reproduces tones in a way that is appreciably different from my other tubes.
> 
> ...




Its reassuring to know that it isnt just me. Speedball is on my list for sure. Im a little hesitant to tackle SMC soldering though...


----------



## dsound

palmfish said:


> Its reassuring to know that it isnt just me. Speedball is on my list for sure. Im a little hesitant to tackle SMC soldering though...


 
  
 It's totally manageable.  I'm not particularly dextrous and I was able to install the upgrade with no issues.  Plus, those heatsinks look pretty awesome.


----------



## captouch

dsound said:


> It's totally manageable.  I'm not particularly dextrous and I was able to install the upgrade with no issues.  Plus, those heatsinks look pretty awesome.




I agree. I'm not very good soldering either compared to many others, but it was no harder for me than the stock kit.


----------



## palmfish

Cool, thanks for the encouragement. 
	

	
	
		
		

		
		
	


	



  
 And now for one last bit of tube porn before I head to bed...


----------



## Loquah

dsound said:


> It's totally manageable.  I'm not particularly dextrous and I was able to install the upgrade with no issues.  Plus, those heatsinks look pretty awesome.


 
  
 +1 on the manageable part - nothing scary at all
  
 Curse you, dsound, you've got me thinking about ways to display the heatsinks now!!


----------



## FlySweep

Well, my (second) pair of HD600's arrived today and I *finally* got to hear it with the Crack.  Not surprisingly, the combo is *every bit* as impressive as I envisioned it being.  Doing some swapping between the 600 & 800 on the Crack tonight.. where the HD800 separates itself from the HD600 is the (spectacularly open) soundstage, more effortless dynamics, an even blacker background, wider frequency bandwidth, and better resolving ability.  Also, I found the HD800's can texture with more finesse.  There are more subtle differences between the two phones.. but those are the areas the differences were most obvious to me.  As far as comfort and fit, I actually prefer the HD600 to the HD800.  Versus the HD800, the HD600 is lighter & I prefer the 600's (comparatively) tighter clamp (since the HD800 tends to shift around somewhat easily when I swing or turn my head).
  
Setting all that aside and coming back to the sound..  I discovered that the HD600 (when driven by the SB'ed Crack) sounds just as _engaging_ and _enjoyable_ (to my ears) as the HD800 does.  Sure the HD800 is more adept and does sound (technically) superior, but what I love *most* about the Senn/Crack pairing is the _organic tonality.  _I've also come to realize that with full sized, open headphones, I tend to value tonal quality more than absolute technical ability or ultra-high resolution.  So, I'm going to miss my (already sold) HD800's immense technical ability and mesmerizing soundstage.. but I can't say I'm going to be devastated to see it go... thanks to just how impressive the HD600 sounds w/ the Crack.  This is the second time I've owned the HD600.. now that I've found what appears to be its 'kindred' amp, I don't anticipate this rig leaving my possession for the foreseeable future.


----------



## ngyu

palmfish said:


> Look what came in the mail today...
> 
> 
> 
> GEC 6AS7G Brown Base care of Nathan!


 
  
 dang... that dark brown finish with the dark grey hammered metal paint looks nice... think I might do that color scheme too!


----------



## Doc B.

The Speedball does not use SMC. It is composed of much easier to solder thru hole components. In fact the only kit with SMCs we plan to do is the new DAC, and there the SMC bits will be pre assembled.


----------



## dsound

loquah said:


> +1 on the manageable part - nothing scary at all
> 
> Curse you, dsound, you've got me thinking about ways to display the heatsinks now!!


 
  





  Vented plexi-window?


----------



## Loquah

dsound said:


> Vented plexi-window?




More like outboard Speedball


----------



## palmfish

doc b. said:


> The Speedball does not use SMC. It is composed of much easier to solder thru hole components. In fact the only kit with SMCs we plan to do is the new DAC, and there the SMC bits will be pre assembled.


 
  
 Good to know. Thanks!


----------



## amcananey

hpiper said:


> I am assuming you would replace the existing caps with others of the same value. Question is how does that improve the sound, what does one cap (of the same value) do better than another?




Actually, I think I used 200uf film caps, whereas the stock electrolytics are 220uf. You could use anything in the 200-250uf range, provided they can handle the voltage. The benefit of film caps is they discharge faster than electrolytics. Bass, for example, draws a lot of power. Film caps can deliver that power faster than electrolytics.


----------



## ffivaz

doc b. said:


> The Speedball does not use SMC. It is composed of much easier to solder thru hole components. In fact the only kit with SMCs we plan to do is the new DAC, and there the SMC bits will be pre assembled.


 
  
 New DAC ? When ?


----------



## W0lfd0g

^
 http://www.bottlehead.com/smf/index.php/topic,4086.0.html


----------



## ffivaz

w0lfd0g said:


> ^
> http://www.bottlehead.com/smf/index.php/topic,4086.0.html




Thanks! I missed the last updates. So, that will be a Christmas DAC


----------



## W0lfd0g

Hi everyone
 
It is time for me to part ways with my Crack.  Unfortunately, its name was prophetic and I have truly become addicted to tube rolling, so much so that I am going to have to take the SS route for a while.
 
Anyway, please let me know if you are interested in any of the following tubes (my premium tubes that I had been holding back):
 
Output
 
2 x Chatham 2399 (5998 equivalent) - NOS white box
1 x Osram 6AS7G round brown base (same as GEC brown base, but with different label) - NOS NIB (sold)
2 x Mullard 6080WA - NOS NIB
3 x Tung Sol 7236 (computer rated version of 5998 in a straight bottle) - NOS white box
2 x Bendix slotted graphite plate 6080WB - NOS white box (1 sold, 1 remaining)
 
Driver
 
9 x Mullard E80CC - NOS NIB
2 x Siemens ECC82 silver plate - NOS minus ~50 hours NIB
1 x Amperex 7316 (ECC186) relabelled for IEC Mullard 1959 D getter - NOS minus ~50 hours NIB
2 x Amperex 7316 (ECC186) - NOS NIB
1 x Tung Sol 12AU7 black glass and black plates - NOS NIB (arrival pending)
 
Please send me a PM if you are interested in any of these and I will do my best to describe the sonic characteristics of each as I hear them.  Before making offers, please research their value.  These are premium tubes.  I'm not a tube trader, so I'm not out to make a profit.  That said, I'm trying to come back from a nasty financial situation. 
 
I've had fun, but it's time for me to heal, pay back my family and take a different path.  When a hobby controls your life, it's time to give that hobby a rest. 
 




 
Nathan


----------



## palmfish

Last night I decided to spend some time tube swapping to see what influence the 12AU7 tube has on the sound. I went back and forth between my CBS 5814a and the 12AU7 that came with my kit (no markings so I don't know what it is). Left the GEC 6AS7G in for the session.
  
 I've come to the conclusion that I am just not able to discern subtle differences between various tubes. Maybe my hearing simply isn't good enough to detect the differences. Whatever the reason, I am satisfied that tube rolling isn't for me.
  
 So... if anyone would like to sample a NOS GEC 6AS7G Brown Base with about 5 hours on it, I would be happy to pass it on for what I paid ($140 USD plus shipping). I'll put a listing up in the FS forum later today, but if you want a crack at it early (pun intended 
	

	
	
		
		

		
			





) drop me a PM.


----------



## sjeffrey

I received my Crack and Speedball parts yersterday.  In the process of building it now.  I remember a post from a member that had suggestions for new builds that would get the speedball installed.  A few things to make the speedball upgrade easier to install.  For the life of me I cannot find that post anymore.  Does anyone know where I can find that post or if someone doesn`t mind posting again?
  
 Thanks,
 Stephane


----------



## Loquah

sjeffrey said:


> I received my Crack and Speedball parts yersterday.  In the process of building it now.  I remember a post from a member that had suggestions for new builds that would get the speedball installed.  A few things to make the speedball upgrade easier to install.  For the life of me I cannot find that post anymore.  Does anyone know where I can find that post or if someone doesn`t mind posting again?
> 
> Thanks,
> Stephane


 
  
 I'm not sure exactly what you're referring to, but I would guess that if you're installing Speedball straight away and not using the amp stock first, you will want to leave out 4 components.
  
 The 4 components replaced by the Speedball are:

The 2 long, white ceramic resistors that sit underneath the vents in the chassis plate (sorry, I don't remember the ratings of the components)
The smaller, more "traditional" looking resistors (sausage shape) that sit to the left and right of the big white ones, on the terminal strip nearest the front of the chassis (see bottom edge of the image below)
  
​


----------



## FlySweep

Loquah.. how does your FA-011 LE sound off the speedballed Crack?


----------



## Loquah

flysweep said:


> Loquah.. how does your FA-011 LE sound off the speedballed Crack?


 
  
 A bit sloppy I'm afraid. Even though the LE version has higher impedance than the standard version, it's still only 120 ohms which is about the same as the Crack's output impedance. You can hear the impact. I still find the LEs to be a solid state-loving headphone. They sound good on my Bottlehead S.E.X., but better from the NFB-5.2 (which is a lower quality amp, but better suited for the LEs)


----------



## sjeffrey

loquah said:


> I'm not sure exactly what you're referring to, but I would guess that if you're installing Speedball straight away and not using the amp stock first, you will want to leave out 4 components.
> 
> The 4 components replaced by the Speedball are:
> 
> ...


 
  
 Thanks Loqah, actually I want to build stock first to get more OMG moments  and to make sure I built everything correctly before going with Speedball.  I actually found the post I was referring to.  Sorry it was over at the BH here: forums, http://www.bottlehead.com/smf/index.php?topic=1870.0


----------



## Armaegis

loquah said:


> I'm not sure exactly what you're referring to, but I would guess that if you're installing Speedball straight away and not using the amp stock first, you will want to leave out 4 components.
> 
> The 4 components replaced by the Speedball are:
> 
> ...


 
  
 Also angle those those two lower caps so you don't have to bend them when the boards go in. Oh and install the spacers before you start putting components in. It's a real bugger finagling some of those little nuts when there's junk in the way.
  
 edit: wow that's possibly the dirtiest unintended sentence I've written on here


----------



## brunk

flysweep said:


> Well, my (second) pair of HD600's arrived today and I *finally* got to hear it with the Crack.  Not surprisingly, the combo is *every bit* as impressive as I envisioned it being.  Doing some swapping between the 600 & 800 on the Crack tonight.. where the HD800 separates itself from the HD600 is the (spectacularly open) soundstage, more effortless dynamics, an even blacker background, wider frequency bandwidth, and better resolving ability.  Also, I found the HD800's can texture with more finesse.  There are more subtle differences between the two phones.. but those are the areas the differences were most obvious to me.  As far as comfort and fit, I actually prefer the HD600 to the HD800.  Versus the HD800, the HD600 is lighter & I prefer the 600's (comparatively) tighter clamp (since the HD800 tends to shift around somewhat easily when I swing or turn my head).
> 
> Setting all that aside and coming back to the sound..  I discovered that the HD600 (when driven by the SB'ed Crack) sounds just as _engaging_ and _enjoyable_ (to my ears) as the HD800 does.  Sure the HD800 is more adept and does sound (technically) superior, but what I love *most* about the Senn/Crack pairing is the _organic tonality.  _I've also come to realize that with full sized, open headphones, I tend to value tonal quality more than absolute technical ability or ultra-high resolution.  So, I'm going to miss my (already sold) HD800's immense technical ability and mesmerizing soundstage.. but I can't say I'm going to be devastated to see it go... thanks to just how impressive the HD600 sounds w/ the Crack.  This is the second time I've owned the HD600.. now that I've found what appears to be its 'kindred' amp, I don't anticipate this rig leaving my possession for the foreseeable future.


 
  
 Does that mean your millenia's impedance box is for sale by chance?


----------



## amcananey

armaegis said:


> It's a real bugger finagling some of those little nuts when there's junk in the way.
> 
> edit: wow that's possibly the dirtiest unintended sentence I've written on here



 


LOL. Too funny...


----------



## Loquah

armaegis said:


> Also angle those those two lower caps so you don't have to bend them when the boards go in. Oh and install the spacers before you start putting components in. It's a real bugger finagling some of those little nuts when there's junk in the way.
> 
> edit: wow that's possibly the dirtiest unintended sentence I've written on here


 
  
 ROFL!!
  
 Great advice too


----------



## Armaegis

It's all in the finagling...


----------



## skeptic

Sjeffrey - a couple of additional recommendations with the speedball addon in mind: (i) screw on the nylon standoffs for the speedball boards before wiring/soldering the A socket, and (ii) to hook up your output caps using fly leads in the event that you ever want to put in film caps.  Happy building!


----------



## Loquah

Ooh, fly leads at initial build stage. Way to prime him to slide down a very slippery (but awesome) track!


----------



## sjeffrey

You guys are terrible 
i am starting to think the non audio version of crack might be a cheaper hobby 

thanks for the advice.


----------



## olegausany

Totally agree. I already spent on tubes as much as I paid for amp


----------



## amcananey

FWIW, I just want to mention that -- while I totally get why people do this, and I am as guilty as anyone else (I have two GEC brown base 6AS7Gs, five 5998s, two Bendix 6080s with graphite plates, etc.) -- it is completely and utterly unnecessary and (I would argue) a waste of money. We are guilty of our own obesessions, and I don't want to keep anyone from tube-rolling to their heart's delight, but I don't want anyone considering the Crack to get the misguided notion that buying expensive tubes is necessary -- or even particularly helpful -- with the Crack. Almost EVERY single tube I've tried in my Crack has sounded wonderful, as long as I wasn't using an adapter. Roll tubes if you want to and it is fun, but don't feel compelled to do so in order to get excellent sound. The Crack will sound wonderful with just about every tube (subject to the usual tube variation with regard to noise and microphonics).

Best regards,
Adam


----------



## palmfish

amcananey said:


> FWIW, I just want to mention that -- while I totally get why people do this, and I am as guilty as anyone else (I have two GEC brown base 6AS7Gs, five 5998s, two Bendix 6080s with graphite plates, etc.) -- it is completely and utterly unnecessary and (I would argue) a waste of money. We are guilty of our own obesessions, and I don't want to keep anyone from tube-rolling to their heart's delight, but I don't want anyone considering the Crack to get the misguided notion that buying expensive tubes is necessary -- or even particularly helpful -- with the Crack. Almost EVERY single tube I've tried in my Crack has sounded wonderful, as long as I wasn't using an adapter. Roll tubes if you want to and it is fun, but don't feel compelled to do so in order to get excellent sound. The Crack will sound wonderful with just about every tube (subject to the usual tube variation with regard to noise and microphonics).
> 
> Best regards,
> Adam




Well said


----------



## skeptic

I'll join in the chorus on this point.  The 6as7g rolling thread, among others, is frankly full of hyperbole and, in certain instances, blatant shilling.  
  
 I do perceive differences between tubes, but they are generally subtle, particularly once the speedball is in place.  Tube rolling is basically a very costly means of eq'ing your rig, which doubles as an excuse for collecting.  My experience has been that there is no direct link between price and sound quality.  For example, I own and enjoy a gec 6as7g, but I am not at all convinced that this tube sounds any better, objectively, than a basic, noise free chatham 6080 I bought for $7.  Having listened to both regularly for a year or so, and now that the new toy syndrome has worn off, I am fairly convinced that I would fail a DBT if asked to differentiate between them.  My favorite input tube at present is fairly a common place 1960's tung sol 12au7, for which I believe I paid $9, plus a couple bucks in shipping.  
  
 Higher transconductance power tubes (5998's, 2339, 7236, and 7802's) do sound a bit different - which makes sense given that they: (i) lower the amp's output impedance, impacting damping, and (ii) have higher gain.  Ultimately, my conclusion, fwiw, is that It is a fool's errand to spend big money on tubes for an amp that sounds great with a wide range of cheap tubes.


----------



## amcananey

skeptic, you said it even better than I did...


----------



## skeptic

Not at all, but thanks!  I just wanted to reinforce the sound advice you and palmfish have been promulgating.  In five years of reading head-fi, this may be the only series of consecutive posts I've ever seen (at least outside of sound science) that advocates saving cash and enjoying the excellent amp we all already own.
  
 Experimenting with tweaks for, uh, lofty scientific purposes is of course exempted


----------



## Doc B.

You are starting to get it, grasshoppers. When you can take the vacuum tube from my hand, it will be time for you to leave.


----------



## mithrandir38

doc b. said:


> You are starting to get it, grasshoppers. When you can take the vacuum tube from my hand, it will be time for you to leave.


 doc, would I be right in assuming that most tube amp makers design their amps to sound as intended with the stock tubes?


----------



## whatthedac

Just got my kit!  It came with an RCA 7152 tube.  I noticed some rattling when I picked it up to examine it.  Is that normal?  I'm still in the build process, so I haven't tested it.


----------



## W0lfd0g

It is not uncommon for there to be very small particles of debris, even glass fragments, inside the tube.  They generally do no impact performance.  Look very carefully just to make they are very small.
  
 Cheers


----------



## W0lfd0g

My love affair has ended.  The flame just burnt too brightly and too hot.  I have pulled my hand back from the fire.  Goodbye Crack.  How I will miss thee!  Tube rolling has been my joy and my bane.


----------



## W0lfd0g

BYW - I do notice a difference in tubes, albeit subtle.  Worth spending the money to optimise the sound of something you already love.  The difference is in more than EQ IMO.  Think speed, clarity and sound stage. 
  
 Just don't go to the extremes that I have!


----------



## Loquah

w0lfd0g said:


> BYW - I do notice a difference in tubes, albeit subtle.  Worth spending the money to optimise the sound of something you already love.  The difference is in more than EQ IMO.  Think speed, clarity and sound stage.
> 
> Just don't go to the extremes that I have!


 
  
 I agree with W0lfd0g that the tubes change more than just the frequency response (i.e. more than just EQing), but I also agree that there's no need to feel like you have to spend a bucket on tubes. 
  
 As much as I prefer the 6AS7G over my other 6080 equivalents, I would still be very happy with any of my sub $35 tubes (which are the majority of my collection). The 6AS7G is an incremental upgrade only, there are no exponential gains that I've found in any of my limited tub rolling experience.


----------



## W0lfd0g

loquah said:


> I agree with W0lfd0g that the tubes change more than just the frequency response (i.e. more than just EQing), but I also agree that there's no need to feel like you have to spend a bucket on tubes.
> 
> As much as I prefer the 6AS7G over my other 6080 equivalents, I would still be very happy with any of my sub $35 tubes (which are the majority of my collection). The 6AS7G is an incremental upgrade only, there are no exponential gains that I've found in any of my limited tub rolling experience.


 
 +1
  
 Don't expect a huge change in sound, just a tweak.  All tubes sound great in this amp.


----------



## palmfish

At least in my case, the difference in microphonics is significant between my 6080 and the 6AS7G. That alone is reason enough for me to use the 6AS7G. That, and the 6AS7G just looks so badass...


----------



## Loquah

palmfish said:


> At least in my case, the difference in microphonics is significant between my 6080 and the 6AS7G. That alone is reason enough for me to use the 6AS7G. That, and the 6AS7G just looks so badass...


 
  
 Yeah, I held back from commenting on the superficial fact that I'd almost stick with the 6AS7G JUST because it looks awesome!


----------



## palmfish

LOL...Im superficial and not ashamed to admit it


----------



## Aeolus Kratos

loquah said:


> Yeah, I held back from commenting on the superficial fact that I'd almost stick with the 6AS7G JUST because it looks awesome!


 
 Haha, and if you are willing to spend $170 just to make your Crack look more awesome, get a GEC 
	

	
	
		
		

		
		
	


	



  
 Unfortunately, I am


----------



## W0lfd0g

Tube rolling skeptic? Don't bother reading this. 
  
 Believer?  Read on!
  
 "Goodbye Crack" tube liquidation!
  
 I'm auctioning off all my tubes, gents.  Could be a chance to get some rare and awesome tubes for $20.00.  Silver plate Siemens ECC82?  Check.  Chatham 5998?  Check (in the form of a 2399).  Slotted graphite plate?  Amperex 7316? Tung Sol 7236?  Check, check and check.
  
 Check it out!
  
 http://stores.ebay.com.au/Winter-Cottage-Books/Audio-Tubes-/_i.html?_fsub=6093602015&_sid=1070780425&_trksid=p4634.c0.m322
  




  
 I have no affiliation with this seller, other than being the seller himself.


----------



## olegausany

So while waiting for the tubes I ordered from Nathan to arrive I got Winged C 6H13C to try with HD700 and after few hours of listening to tracks of different style and recording quality (they are all loseless) I prefer it over 5998 tube cause it adds more body to the bass and gives less shrill to highs while maintaining clarity and details


----------



## sjeffrey

I'm happy to say that my Crack is built and working 
 Took a few hours to troubleshoot what end up being a cold solder joint.  All in all the build was fun and very straightforward.  I soldered more on this build than the rest of my life combined.  I ended up retouching some of my solders by the time I was halfway done because my soldering skills got better as I built.  I would say it took me about 12 hours to build plus another 3 to troubleshoot.  I also set it up to simplify the Speedball upgrade by putting in standoffs so wires would be routed around them and mounted the output capacitors so they wont be in the way of the Speedball.
  
 First impressions: WOW!  I am glad I got this thing and can't wait to see how it will be with the Speedball upgrade.
 I'll be pairing it with my Uber Bifrost later.  Testing with an iTouch now because it was simpler.
 Also got a few tubes from Nathan on the way which I will be testing and a Tung Sol 5998 courtesy of Pepper that I'll be trying this week.
  
 Now I have to somehow pull myself away from my Crack to get some sleep.  Not sure I will be successful at that 
  
 Steph


----------



## palmfish

Congrats!
  
 How about some pictures?


----------



## sjeffrey

Pictures soon, first I have to stain the base. I also painted the plate and bell but messed up the bell a little :|. As long as she sounds fine I don't mind a few scars.


----------



## Loquah

sjeffrey said:


> Pictures soon, first I have to stain the base. I also painted the plate and bell but messed up the bell a little :|. As long as she sounds fine I don't mind a few scars.


 
  
 I can fully relate. My Crack was very "no frills" and has some minor scarring, but I love the sound regardless. I took more time on the SEX and had the benefit of a working Crack to keep me busy while I waited to perfect the paint finishes.


----------



## olegausany

Finally got a chance to try HD800 with silver/cooper cable instead of stock one with the gear I have. First of all I found out that sound great with Crack using KENRAD 6SN7/VT231 and Winged C 6H13C i prefer with HD700 but it's clear that HD800 is better mach for Crack. For those who want to save money on tubes I would recommend  to use provided 6080WA tube paired with Westinghouse 12AU7 black plate from 1956 but if you want more highs clarity I would use Chatham 5998 labeled 2399 instead of 6080 cause difference is easily noticeable. I also tried RCA 12AU7 Cleartop instead of Westinghouse with the tubes above but prefer Westinghouse over RCA.


----------



## sjeffrey

So I wanted to try a used 5998 tube that I have and after a few seconds of turning it on and both tubes glowing there was smoke coming out the case.  I put the stock 6080 tube and had popping sound when plugging the headphones in.  Well the popping I figured would be a bad ground connection as it was only happening when inserted my headphones plug.  Got that resolved pretty easily.  It might be worth mentioning that over at the BH forum the guys mentioned you can connect all 3 outboard connections on the TRS jack which will keep the voltage at 0 when no headphones are plugged in.
  
 So now my stock tube is playing fine, headphones are also fine.  What could cause the smoke?  Should I try the tube again?  Also wanted to mention there is a lot of broken glass in the 5998 tube.  I read it should be ok but this is not a small amount, I would say at least a dozen pieces, small bigger than others.
  
 Thanks,
 Steph


----------



## brunk

sjeffrey said:


> So I wanted to try a used 5998 tube that I have and after a few seconds of turning it on and both tubes glowing there was smoke coming out the case.  I put the stock 6080 tube and had popping sound when plugging the headphones in.  Well the popping I figured would be a bad ground connection as it was only happening when inserted my headphones plug.  Got that resolved pretty easily.  It might be worth mentioning that over at the BH forum the guys mentioned you can connect all 3 outboard connections on the TRS jack which will keep the voltage at 0 when no headphones are plugged in.
> 
> So now my stock tube is playing fine, headphones are also fine.  What could cause the smoke?  Should I try the tube again?  Also wanted to mention there is a lot of broken glass in the 5998 tube.  I read it should be ok but this is not a small amount, I would say at least a dozen pieces, small bigger than others.
> 
> ...


 
  
 My crack is finished, but i installed a 12bh7 first with resistors in place of LEDs. However, it burned out my 2 sets of 5w cement resistors so im waiting for replacements. I scoured the BH forums and a guy installed a 12BH7 and had same resistors burnt out. It turned out to be a bad 12BH7. I have a new BH7, but am waiting for my resistors. Im dying to hear my maxed out crack lol!


----------



## sjeffrey

sjeffrey said:


> So I wanted to try a used 5998 tube that I have and after a few seconds of turning it on and both tubes glowing there was smoke coming out the case.  I put the stock 6080 tube and had popping sound when plugging the headphones in.  Well the popping I figured would be a bad ground connection as it was only happening when inserted my headphones plug.  Got that resolved pretty easily.  It might be worth mentioning that over at the BH forum the guys mentioned you can connect all 3 outboard connections on the TRS jack which will keep the voltage at 0 when no headphones are plugged in.
> 
> So now my stock tube is playing fine, headphones are also fine.  What could cause the smoke?  Should I try the tube again?  Also wanted to mention there is a lot of broken glass in the 5998 tube.  I read it should be ok but this is not a small amount, I would say at least a dozen pieces, small bigger than others.
> 
> ...


 
 I just tried the tube again and was keeping an eye on the tube and board.  Everything was fine up until about 3-4 minutes.  Smoke started gathering in the top right corner where the power is fed.  The plate was propped open on top of the box as I dont want to put the tube with all broken glass upside down.  I posted in the BH forum, hopefully someone can give me hand.  I had the Crack running for about 1 hour this morning with the stock tube and there was no smoke at all.


----------



## palmfish

Sure sounds like a bad tube to me.

A little dust on the inside of the glass is normal, but pieces of broken glass inside the tube is not.


----------



## Loquah

sjeffrey said:


> I just tried the tube again and was keeping an eye on the tube and board.  Everything was fine up until about 3-4 minutes.  Smoke started gathering in the top right corner where the power is fed.  The plate was propped open on top of the box as I dont want to put the tube with all broken glass upside down.  I posted in the BH forum, hopefully someone can give me hand.  I had the Crack running for about 1 hour this morning with the stock tube and there was no smoke at all.


 
  
 So is the smoke coming from the Crack wiring or the tube? (I'm assuming the Crack because the tube should be sealed)


----------



## sjeffrey

loquah said:


> So is the smoke coming from the Crack wiring or the tube? (I'm assuming the Crack because the tube should be sealed)


 
 From the crack.  Got a message from Doc B. saying it's probably a bad tube.  I've been listening for about 1 hour now with the stock 6080 and no issues, other than my head bobbing to the music


----------



## Aeolus Kratos

If the Crack works fine with other tubes except the 5998, it's pretty certain that is a bad 5998.
  
 The broken glass inside your tubes is not a problem as long as your tubes work fine. My 6080 and 5998 have some small pieces of glass inside them, but they work perfectly fine.


----------



## Aeolus Kratos

After weeks of waiting....
  
 Finally, I've got delivery 
	

	
	
		
		

		
			




  

  


 The Chatham 2399
  

 The wonderful GEC 6AS7G Brown Base
  

 Matched pair Tungsram E80CC
  

  
 That's a GEC 6AS7G Brown Base from Nathan!!
  
 Thanks again W0lfd0g


----------



## olegausany

My GEC which I purchased from Brian and he originally from Nathan just came in so will do aquick listen before I leave to work


----------



## JamieMcC

aeolus kratos said:


> After weeks of waiting....
> 
> Finally, I've got delivery
> 
> ...


 
  
  
 Oh man such posts should come with a warning attached the temptation for us newbie crack addicts is damn near irresistible. Its taken me all my will power and resilience so far to hold off from buying any tubes until after my Crack kit arrives and then you go and post the above! It must seem like Christmas has come early in your house  
  
 It would be great if you could give some feed back on the different combos when you try them.
  
 In the meantime I will just have to satisfy myself by keeping an eye out on ebay and checking on a few dealers sites as I would like to have a couple of spares to hand.
  
  
  
  
  
 .


----------



## olegausany

So after quick audition I clearly hear that GEC 6AS7G gives improved clarity of details and bass control. Remember that all these with not recommended HD700


----------



## Doc B.

sjeffrey said:


> From the crack.  Got a message from Doc B. saying it's probably a bad tube.  I've been listening for about 1 hour now with the stock 6080 and no issues, other than my head bobbing to the music


 
  
 I said it was absolutely a bad tube and stop using it before the amp is permanently damaged. Seeing smoke is always bad. The smoke inside the parts is what makes amps work. If you let the smoke out of the parts they won't work anymore.


----------



## palmfish

[COLOR=FF00AA][/COLOR]





olegausany said:


> So after quick audition I clearly hear that GEC 6AS7G gives improved clarity of details and bass control. Remember that all these with not recommended HD700




Hey Oleg, Im glad to hear it worked out for you! Enjoy!


----------



## olegausany

palmfish said:


> [COLOR=FF00AA][/COLOR][quote name="olegausany" url="/t/476650/crack-bottlehead-otl/2850#post_9868252"]So after quick audition I clearly hear that GEC 6AS7G gives improved clarity of details and bass control. Remember that all these with not recommended HD700


Hey Oleg, Im glad to hear it worked out for you! Enjoy![/quote]

Thanks a lot but you made a big mistake. Which headphones you have?


----------



## palmfish

olegausany said:


> Thanks a lot but you made a big mistake. Which headphones you have?




No mistake Oleg. I have HD 800's.


----------



## whatthedac

I'm about to do the voltage check.  It says to attach the negative lead of the DMM to ground (terminal 12).  Then the next step says to turn the chassis over and reconnect the negative lead of the DMM to the ground bus.  Now it says to plug it in and turn it on to see if the filaments glow.  Then wait and test with the positive leads of the DMM.
  
 Why am I putting the negative leads on in the first step.  And then putting them on again in the second step?


----------



## sjeffrey

That part of the instructions confused me as well. As long as you have checked for smoke you can safely unplug it, turn it over, put negative lead in t12, turn back on and take positive lead for the terminal readings.


----------



## whatthedac

Last question, what if the TRS jack test at the end stays around a few mV (20-35)?  I thought I saw it jump to 1V, but I'm not sure.  I was touching the inboard TRS ring terminal with ground at terminal 12.


----------



## sjeffrey

As long as it doesn't go over 9v. Mine would slowly climb to a few volts then back down to 0. You should do the mod the guys from BH posted in their forums. You simply connect the 2 unused terminals from TRS jack to the bottom closest to plate. This will keep voltage at 0v when you power on.


----------



## sjeffrey

Edit, on mobile and can't seem to quote posts properly. This is re: Doc B's comment.

Just to be 100% clear, the smoke came from the crack and not the tube. The tube is intact on the outside. There is quite a lot of glass moving inside and you can see the 2 outer copper wires have glass broken off exposing a bit of copper. I can post pictures later, I am on mobile phone now and can't figure out how to attach.

since I don't have speedball on yet, are the 6080 and 2399 the same requirements? I purchased this tube from a fellow headfi member and we want to get to the bottom of this.

thanks,
Stephane


----------



## whatthedac

sjeffrey said:


> As long as it doesn't go over 9v. Mine would slowly climb to a few volts then back down to 0. You should do the mod the guys from BH posted in their forums. You simply connect the 2 unused terminals from TRS jack to the bottom closest to plate. This will keep voltage at 0v when you power on.


 
  
 Thanks for your help (and the tip).  All done!  Everything checked out and it sounds great.  Couldn't be happier.


----------



## sjeffrey

aeolus kratos said:


> After weeks of waiting....
> 
> Finally, I've got delivery
> 
> ...


 
 I saw this post together and got excited as I was also waiting for some tubes from W0lfd0g.
 When I got home I had a pretty box waiting for me 
  
 Put in the Tung Sol 7236 and RCA clear top first.  Listening right now and it sounds great although A/B comparison at this point will be to hard.  I'm still on my honeymoon with my BH Crack 
 I'm saving the famous Brown Base for later.  W0lfd0g recommended the 7236 for my HD650s but I was too curious to pass up a good price for the BB.
 I also have a few input tubes for later, GE and Sylvania 5936, RCA clear top and a Baldwin (12UA7, not one of the actors)
  
 Oh and good news / bad news, no smoke...  So my crack is still go but  I'm bit bummed about not getting to try the 2399/5998.  Most likely the tube got damaged in shipment 
  
 Big thanks to Nathan for the tubes.
  
 Steph


----------



## Loquah

doc b. said:


> I said it was absolutely a bad tube and stop using it before the amp is permanently damaged. Seeing smoke is always bad. The smoke inside the parts is what makes amps work. If you let the smoke out of the parts they won't work anymore.


 
  
 So, Doc, do tube amps use the same magic smoke as solid state gear?


----------



## amcananey

I can't answer that question. I can tell you that when I fumigated my Crack, I noticed a clear and unmistakable increase in bass extension and impact, a sweetening of the mids, and additional treble clarity. I would say this had a greater impact than tube swapping, installing my TKD pot, or upgrading the coupling caps, although not as great as upgrading the power supply caps. Of course, the downside was the need to tent my Crack for two weeks in order to allow sufficient time for the smoke to absorb into all of the components. It's hard to quit Crack cold-turkey! The twitches and spasms have now mostly subsided, however...


----------



## Aeolus Kratos

jamiemcc said:


> Oh man such posts should come with a warning attached the temptation for us newbie crack addicts is damn near irresistible. Its taken me all my will power and resilience so far to hold off from buying any tubes until after my Crack kit arrives and then you go and post the above! It must seem like Christmas has come early in your house
> 
> It would be great if you could give some feed back on the different combos when you try them.
> 
> In the meantime I will just have to satisfy myself by keeping an eye out on ebay and checking on a few dealers sites as I would like to have a couple of spares to hand.


 
 Hi Jamie,
  
 Indeed, I could not be happier my Crack. But as everyone else would say, if your Crack doesn't have the Speedball yet, get one first. There is no doubt that it is the best upgrade for the Crack. But the speedball will reduce the effect of tubes you try. That means you will not experience huge change in sound when you roll tubes if your Crack have the speedball installed.
  
 In my own experience, the 5998 and the famous GEC Brown base are truly among the best power tubes you can try with your Crack. They have different sound characteristics. I actually can't decide which is 'better', all I can say that I slightly prefer the GEC over the 5998, because it gives my Crack a more 'tubey' sound - sweet, warm, liquid but still with a lot of details and clarity.
  
 Enjoy building your Crack and happy listening!
  
 Cheers,
 Kratos.
  


olegausany said:


> So after quick audition I clearly hear that GEC 6AS7G gives improved clarity of details and bass control. Remember that all these with not recommended HD700


 
 Nice! Glad you like it. I assume your Crack does not have the Speedball installed yet?
  


sjeffrey said:


> I saw this post together and got excited as I was also waiting for some tubes from W0lfd0g.
> When I got home I had a pretty box waiting for me
> 
> Put in the Tung Sol 7236 and RCA clear top first.  Listening right now and it sounds great although A/B comparison at this point will be to hard.  I'm still on my honeymoon with my BH Crack
> ...


 
 As far as I know, the 7236s are pretty similar with the 5998s ( not equivalent I think ). I have not tried a 7236, but I've tried several 5998s with my HD650 and it sounded fantastic, thanks to their transparency, clarity and some nice sparkling treble, they added perfectly with the dark, 'veil' and muddy sound of the HD650s, I think the 7236s would also do the same thing to the HD650.
  
 I have to admit that I initially thought the GEC Brown base is just the tweak of sound when compared with the 5998s, but after several hours of listening, the most noticeable improvement was the microphonics, the GEC did not cause ANY microphonics AT ALL. It made the Crack even more 'dead silent', one of the darkest and cleanest background I've ever heard. The bass control although was not as tight as the 5998, but it gave the bass more body, depth and make it fuller. The mid-range was sweet, liquid and neutral.
  
 I also have a not-Alec-Baldwin-actor 12AU7 ( actually it is a Toshiba 12AU7 ), a RCA Clear-top, GE 5936, a RCA Smoked-glass 6SN7 from Nathan. And I liked the RCA the most among those, but my favorite input tube so far is still the Tungsram E80CC.
  
 Thanks again, Nathan. I'm sorry to hear that you sold your Crack, hope you'll be back


----------



## olegausany

My Crack has Speedball installed


----------



## W0lfd0g

Glad to hear that people's tubes have started arriving. I really appreciate the impressions that you have posted. It's great to get other opinions and gear matching experiences.

I wish I could have kept the Crack. The matching with the Beyer T90s is one of the most synergistic systems I have owned. 

I'll be back in the tube amp game one day, Kratos. I will explore DIY SS in the meantime.

Cheers

Nathan


----------



## Nic Rhodes

I don't see my Crack as a rollers amp, quite the opposite tbh especially with the speedball upgrade but the comments about low microphonics with the GEC A1834 is smack on (pun intended). This is why I like this tube on the Crack. On other 'roller amps however it is a gem....unfortunately now expensive but on this amp it is the noise or lack of it that makes it an excellent match.


----------



## Loquah

nic rhodes said:


> I don't see my Crack as a rollers amp, quite the opposite tbh especially with the speedball upgrade but the comments about low microphonics with the GEC A1834 is smack on (pun intended). This is why I like this tube on the Crack. On other 'roller amps however it is a gem....unfortunately now expensive but on this amp it is the noise or lack of it that makes it an excellent match.


 
  
 I'm not questioning these experiences, but I have never experienced any significant microphonics with the Crack, except for with 1 dodgy tube.


----------



## ffivaz

w0lfd0g said:


> I'll be back in the tube amp game one day, Kratos. I will explore DIY SS in the meantime.




And you'll end rolling opamps


----------



## brunk

w0lfd0g said:


> Glad to hear that people's tubes have started arriving. I really appreciate the impressions that you have posted. It's great to get other opinions and gear matching experiences.
> 
> I wish I could have kept the Crack. The matching with the Beyer T90s is one of the most synergistic systems I have owned.
> 
> ...


 
  
 What DIY SS you going with? Maybe we can compare notes!


----------



## W0lfd0g

Looking into the M^3 and gamma 1, but am open to suggestions. What projects are you working on ATM?


----------



## brunk

w0lfd0g said:


> Looking into the M^3 and gamma 1, but am open to suggestions. What projects are you working on ATM?


 
  
 Currently, two First Watt F5 amps, and a Hagerman Tech Cornet2 SET (Single Ended Triode) Phono Pre as far as electronics go. I don't have anything against AMB Labs whatsoever, but I just don't like the fact they use so many parts and that the pieces aren't cheap. I honestly think their vested interest is in selling you electronic tidbits before anything else IMO. My next project may be a F5 Turbo, Aleph J, or "The Wire" headphone amp.
  
 What is the end goal with your desired project? I may be able to recommend some alternative options for you 
  
 Apologies if I have gone off-topic, feel free to PM me if you wish.


----------



## Nic Rhodes

loquah said:


> I'm not questioning these experiences, but I have never experienced any significant microphonics with the Crack, except for with 1 dodgy tube.


 
  I think you will notice it more when it is not there more than when it is there in variable amounts.


----------



## olegausany

So I'm using GEC6AS7 for few hours and as I said in my previous post sounds great when paired with Westinghouse 12AU7 black plate from '50 with yellow CONN labeling. Also I decided to try GE5814 with GEC and I found that at first the combo sounds identical to Westinghouse 12AU7 so it's impossible to hear the difference but later I found 2 recordings where I by some reason prefer 5814 over 12AU7 so I gonna keep like this but will try KENRAD6SN7 just out of curiosity tomorrow but I doubt it will work well. Honestly my current setup could be easily end of the game for me but after hearing HD800 I deffinitely want them and only than call the end because for me the difference between HD700 and HD800 very noticeable.


----------



## Aeolus Kratos

w0lfd0g said:


> Glad to hear that people's tubes have started arriving. I really appreciate the impressions that you have posted. It's great to get other opinions and gear matching experiences.
> 
> I wish I could have kept the Crack. The matching with the Beyer T90s is one of the most synergistic systems I have owned.
> 
> ...


 
  
 Great to hear that, Nathan! I couldn't happier with the GEC. I sold all of my other power tubes ( including the popular Tung-sol 5998 ) and save pennies for the upcoming Bottlehead DAC, can't wait to have full BH setup


----------



## olegausany

So I did try to pair KENRAD 6SN7 with GEC 6AS7 and while It sounds better than paired with 5998 I still recommend to use 5814 or 12AU7 because of the way bass is presented


----------



## rujunfei

he photos are up on the bottlehead site :facepalm: Great news, there is room for smallish OPT's


----------



## diaBoliQu3

I can't find comparison for O2amp vs Crack. Interested with Crack but the price, phew....


----------



## palmfish

diaboliqu3 said:


> I can't find comparison for O2amp vs Crack. Interested with Crack but the price, phew....




Depends on the headphone.


----------



## diaBoliQu3

palmfish said:


> Depends on the headphone.


 
 Sorry. Forget to mention. Senn HD600...


----------



## palmfish

Well, the short answer then is... The O2 is fast, articulate, lean, and clear while the Crack is warmer, meatier, smoother, and more liquid.


----------



## diaBoliQu3

palmfish said:


> Well, the short answer then is... The O2 is fast, articulate, lean, and clear while the Crack is warmer, meatier, smoother, and more liquid.


 
 So you compared both right? Does Crack really good as they are hyped?


----------



## JamieMcC

Has anyone used or are using a Brimar 13D5 in their Crack if so could you please share your views on it.
  
 I am not sure if they are a 12UA7 or a direct replacement I am a bit wary of taking the "direct replacement" comments as gospel?
  
 Cheers


----------



## Nic Rhodes

diaboliqu3 said:


> So you compared both right? Does Crack really good as they are hyped?


 

 Palmfish description is smack on imho, with the HD 600 both these amps work very well but are just different. I have a soft spot for OTLs (headphone 300 ohms and above) but the O2 (Epiphany Audio here) and E12 are really excellent small solid state amps. Does the Crack live upto the hype, yes, add a speedball and it gets a bit special but only for headphones 300 ohms and above.


----------



## diaBoliQu3

nic rhodes said:


> Palmfish description is smack on imho, with the HD 600 both these amps work very well but are just different. I have a soft spot for OTLs (headphone 300 ohms and above) but the O2 (Epiphany Audio here) and E12 are really excellent small solid state amps. Does the Crack live upto the hype, yes, add a speedball and it gets a bit special but only for headphones 300 ohms and above.


 
 Currently using Aune T1. Wondering if I should change my DAC together too or just spend price of Objective combor or Schiit combo and invest in amp only with Aune T1 DAC. I wonder if above combo is an upgrade from Aune T1. Crack with speedball over my balls could afford. 
	

	
	
		
		

		
		
	


	




 Or I guess, try hard to funding for Crack OTL at least?


----------



## olegausany

I have both right now Crack with Speedball  and Lyr with Bifrost Uber driving not recommended HD700 and with right set of tubes I prefer Biffrost/Crack combo over Bifrost/Lyr and yes I have Amperex Orange Globes but Buggle Boys for Lyr


----------



## Loquah

I would say that Crack and Aune T1 would pair well. You can always add Speedball later and / or upgrade the DAC


----------



## palmfish

Not knowing what the Aune DAC sounds like, I will say I agree with Loquah.

I really havent noticed much difference between all the DACs Ive heard over the years. The only notable exception is the prototype Bottlehead DAC. It was noticeably warmer and lusher sounding than the Benchmark DAC1 I compared it to, and the DAC1 sounded the same to my ears as all of my other DACs (both discrete and built in). 

Thats why Im done buying DACs - at least until I decide to start using a computer as a music source, which I have no current plans to do. If or when I do, I think an ODAC or something similar is the way I would go.


----------



## olegausany

I didn't try many DACs but for Bifrost is noticeable improvement over DAC of WA7 when used with either WA7 amp, Lyr or Crack


----------



## i luvmusic 2

has anyone paired CRACK with dt880 600 ohms?


----------



## DefQon

Bit bright and shrilly top end.


----------



## brunk

i luvmusic 2 said:


> has anyone paired CRACK with dt880 600 ohms?


 
 Yes, several have and report that it's good. Matter of fact, I honestly haven't seen any real complaints about the Crack with 300+ ohm headphones. It's a specialty amp for made for Beyers and Senns really


----------



## i luvmusic 2

brunk said:


> Yes, several have and report that it's good. Matter of fact, I honestly haven't seen any real complaints about the Crack with 300+ ohm headphones. It's a specialty amp for made for Beyers and Senns really


 
 ok thanks! i'm planning to get this for my first DIY AMP.


----------



## brunk

i luvmusic 2 said:


> ok thanks! i'm planning to get this for my first DIY AMP.


 
 Definitely a great first choice for a beginner and those headphones.


----------



## amcananey

palmfish said:


> Well, the short answer then is... The O2 is fast, articulate, lean, and clear while the Crack is warmer, meatier, smoother, and more liquid.




For what it's worth, as far as I'm concerned, when it comes to high impedance headphones, I think the comparison is a no brainer in favor of the Crack.

Yes, the O2 is fast, articulate and clear, but I don't find the Crack to be any less fast, articulate or clear. The O2 is, however, decidedly lean, and it is here that the Crack just stomps all over the O2 (which is a very, very good amp and still recommended for use with other headphones). In particular, bass is entirely different through the O2 and the Crack. And there are big differences in aesthetics and practicalities. The O2 runs off batteries, shouldn't be left plugged in all the time, and has an exceptionally crowded front faceplate. The Crack is...a desktop amp that can be as beautiful as you make it (or, in my case, as ugly). 

For high impedance cans, save up and get the Crack.


----------



## amcananey

palmfish said:


> I really havent noticed much difference between all the DACs Ive heard over the years. ... the DAC1 sounded the same to my ears as all of my other DACs (both discrete and built in).
> 
> Thats why Im done buying DACs - at least until I decide to start using a computer as a music source, which I have no current plans to do. If or when I do, I think an ODAC or something similar is the way I would go.




Palmfish,

I couldn't agree more. I doubt I could tell the difference between my current $1,000 DAC and an ODAC in a blind test, and I've owned all kinds of DACs. Other than really cheap units, I think they all sound the same once you control for strength of the output signal. 

Best regards,
Adam


----------



## amcananey

And by really cheap, I mean under $100.


----------



## amcananey

defqon said:


> Bit bright and shrilly top end.




+1, but I think that is the fault of the DT880s, not the Crack.


----------



## skeptic

palmfish said:


> Well, the short answer then is... The O2 is fast, articulate, lean, and clear while the Crack is warmer, meatier, smoother, and more liquid.




Well said! I would add to this that the crack 's sound stage is also far better than my diy o2 with high Z headphones, and timbre is also more natural to my ears. o2 uses heavy global negative feedback to achieve its noise targets, and I tend to agree with the folks who have suggested that this translates into a tiny amount of treble glare. Generally speaking, listening to my crack is just a more immersive, enjoyable, and with upbeat music, toe tapping experience than listening to my o2. 

Also, as far as tube amps go, bear in mind that crack is on the detailed and dynamic side of the spectrum. It sounds a lot faster, punchier and more exciting than something like a woo 3 - which I enjoyed for several years but proved, in comparison to the crack, slow, overly warm and flat from the stand point of dynamics. For me, there was no going back once I had finished my crack. 

Finally, the crack has outstanding synergy with 300 ohm Senns, and I don't feel that the o2 pairs very well with these phones at all. I still use my o2 regularly in a tiny bedside rig, driven by an ipad4->cck->hub->odac, but I find it far better with my modded fostex t50rp's, w4's and even dt880's (250 ohm), than with my 650's or 800's. Assuming that I can manage the smd work, my long term plan is to build and replace the o2 with a se "wire" amp (since my side table is just too low and accessible to my toddler to run tubes in that spot any time in near future).


----------



## palmfish

I spent a few hours listening to music yesterday - about half of the time with my Crack and the other half with my Essence One Muses.
  
 For a lot of my 80's vintage CDs (FLAC rips) the Crack adds just the right about of meat and body to compensate for the overly thin master sound. OTOH, some of my recordings that have a "boosted" bass in the recording (Daft Punk - Randon Access Memories for example), the Crack can sound a bit too thick and heavy and I prefer the more neutral-sounding Essence One.
  
 What I started noticing yesterday though is that there is a slight "haze" or "veil" with the Crack when compared to the Essence One. In other words, the Essence One sounds just a little cleaner and clearer (but not brighter in treble).
  
 It has me wondering if this is what the Speedball addresses and that I may be finally ready to go for it (when the govt starts paying me again, that is 
	

	
	
		
		

		
			





 ). My concern about the Speedball has always been that it will make my Crack sound more like my Essence One and I don't want that because I enjoy the unique qualities of both amps. However, if I can keep my Crack sounding the same, only cleaner and clearer, then it's a no-brainer to me.
  
 Thoughts? Adam?


----------



## Loquah

The Speedball tightens the bass and drops the noise floor, but doesn't change the character of the amp. Although I haven't heard the Essence, I'm pretty comfortable in suggesting that they'll still sound very different. 

With Speedball the Crack is still warm, creamy and musical, but a bit tighter and punchier.


----------



## palmfish

Thanks for the feedback Loquah - I was hoping you would chime in.
  
 The trouble I have is that the bass seems to be the major difference between the Crack and the SS amps I have owned/used in the past. The big, round, musical bass that adds warmth and body yet doesn't muddy up the mids or affect the treble. Yet I think that the upper bass warmth is contributing to the "haze" Im hearing, so I don't know what to think.
  
 Tightening up the bass sounds good in theory, but if it loses that warm body, then it will be more "SS sounding" Im afraid.
  
 I guess the only thing is for me to hear for myself. Perhaps another visit to BH HQ is in order. Listen to my Crack side-by-side with a Speedball Crack and decide. If I like it, I suppose I can get the Speedball kit on the spot and take it home with me


----------



## brunk

palmfish said:


> Thanks for the feedback Loquah - I was hoping you would chime in.
> 
> The trouble I have is that the bass seems to be the major difference between the Crack and the SS amps I have owned/used in the past. The big, round, musical bass that adds warmth and body yet doesn't muddy up the mids or affect the treble. Yet I think that the upper bass warmth is contributing to the "haze" Im hearing, so I don't know what to think.
> 
> ...


 
 If you're worried about the the "SS" sound, i think the best course of action before adding the Speedball for you would be to add a film cap or three in the power supply. I have a Solen 200uf 250v installed on the last (3rd) cap in the power supply. It's a tricky fit if you have film signal caps already like i do, but it does fit in the stock chassis just fine.


----------



## amcananey

I agree that the Speedball doesn't change the overall nature/quality of the sound. I also agree with inserting film caps in the power supply. I found bypassing the last cap didn't do anything for me. Replacing all three made a big difference, but I can't say whether just replacing the last one would be enough to do the trick. It might.


----------



## palmfish

$65 ea. for film capacitors?!?! Damn!

And these replace the large black and silver caps that are on there now? At least they look easier to install thanks to there long wire leads...

EDIT: Holy crap! Those solen caps are 60mm X 108mm!


----------



## amcananey

The ones I installed were $10 each. Bought them off ebay.


----------



## amcananey

See here: http://www.ebay.com/itm/ICAR-LNF-P3B-200-30-CAPACITOR-200uF-10-Un-420V-Urms-300VAC-420VDC-/230968898220?pt=LH_DefaultDomain_0&hash=item35c6d1b2ac


----------



## palmfish

Ah ha! The caps in your photos.

No, my Crack is not going there...lol. I'll try the Speedball and call it good.


----------



## brunk

palmfish said:


> Ah ha! The caps in your photos.
> 
> *No, my Crack is not going there...lol.* I'll try the Speedball and call it good.


 
 Lol, you never know...


----------



## palmfish

brunk said:


> Lol, you never know...


 

 True. But I have time to think about it...
  
 I just finished what has to be the most tedious soldering project ever. I replaced the 24 individual incandescent light bulbs from my cars third brake light and replaced them with LEDs (after having to crack each one open like a walnut). My fingers are raw - I am so done with soldering!


----------



## amcananey

You could always use these (wired in parallel), but even I ruled them out as too ugly...


----------



## palmfish

amcananey said:


> You could always use these (wired in parallel), but even I ruled them out as too ugly...


 
  
 You Crack me up Adam (pun intended)! You could mount them on the side and paint them flesh colored and then paint the nuts pink...


----------



## brunk

palmfish said:


> You Crack me up Adam (pun intended)! You could mount them on the side and paint them flesh colored and then paint the nuts pink...


 
 LMAO... that's exactly what he needs to complete his blue butt cheeks, some pink nuts! 
	

	
	
		
		

		
		
	


	




 Though blue nuts and a pink butt cheek might be better if hes a masochist


----------



## palmfish

Youre killin me guys...


----------



## whatthedac

How difficult do you guys think it would be to add an auto-shutoff to the crack?  I keep forgetting to turn it off before I leave.  And if not difficult, would it change the sound at all?
  
 Edit:  Last week I bought a Sino 6AS7G, just for fun.  I much prefer the RCA 6080 tube that with the crack.  No speedball.


----------



## Loquah

You could probably use a power socket timer device. I expect some would have a delayed shutoff system on them where they automatically switch off after a period of time. I haven't specifically ever looked for this, but wouldn't be surprised if it's out there. Of course, it might get annoying if it powers down halfway through a listening session though. Maybe a more intelligent system would be better, but not sure how that would work.


----------



## olegausany

Finally got my tubes from Nathan and first of all decided to try Mullard E80CC and GEC 6AS7 combo and got the best sound I heard so far with smooth sound and holographic soundstage


----------



## brunk

loquah said:


> You could probably use a power socket timer device. I expect some would have a delayed shutoff system on them where they automatically switch off after a period of time. I haven't specifically ever looked for this, but wouldn't be surprised if it's out there. Of course, it might get annoying if it powers down halfway through a listening session though. Maybe a more intelligent system would be better, but not sure how that would work.


 
 I use this. Better than a timer, and easier to remember since it's just a push of a button on a remote. 
	

	
	
		
		

		
		
	


	



  
http://www.amazon.com/Stanley-31165-Wireless-Remote-System/dp/B00A3XTCOE/ref=pd_sim_sbs_hi_10


----------



## olegausany

I also tried Mullard E80CC with Telefunken 6AS7 and with this combo bass i presented is a little bit forward. Replacing E80CC with GE 8514 rolls off highs so will be suitable for those who feel that their headphones sound bright. To remove the roll off and to balance the bass while keeping punch and body you can use Westinghouse 12AU7, also Kenrad 6SN7 pairs nice with Telefunken 6AS7 eleminating bass emphasis completely but keeping depth and body. If you replace Telefunken with RCA it pairs well too but bass depth will be less


----------



## amcananey

whatthedac said:


> How difficult do you guys think it would be to add an auto-shutoff to the crack?  I keep forgetting to turn it off before I leave.  And if not difficult, would it change the sound at all?




1. What is your source?
2. Do you ever use your source with anything other than the Crack?
3. Do you ever forget to turn off your source, or is it just the Crack you forget to turn off?


----------



## olegausany

Tried Tumgsol 7236 with both Kenrad 6SN7 and GE 8514 and it's nice with 8514 but treble are rolled off with Kenrad but too much treble if you replace Kenrad with Mullard E80CC


----------



## ALL212

Can I play?!!
 I have a Crack with Speedball upgrade and other up'd parts.  I've ran through the following 12AU7's and variants.
 RCA cleartops
 CBS Hytron 12au7
 CBS Hytron 5814
 5963 "Black Pearls"
 Siemens 5814 triple mica
 Amperex 12au7
 Amperex 7316
 Valvo E80CC
  
 The Amperex 7316 and Valvo E80CC's are the winners there.
  
 I've run some 6AS7's and 6080's also and the winner there is the Raytheon 6080Wc with the heavy carbon plates.
  
 I found that once I settled on the big tube I could then listen more carefully to the little guy to pick out the good ones.  Then I rotated back to the big tubes to insure the pair was optimal.
  
 I run HD650's with upgraded cable.


----------



## brunk

all212 said:


> Can I play?!!
> I have a Crack with Speedball upgrade and other up'd parts.  I've ran through the following 12AU7's and variants.
> RCA cleartops
> CBS Hytron 12au7
> ...


 
 Outstanding first post! Let me be the first to say, welcome to Head-Fi, sorry about your wallet!


----------



## ALL212

Thanks!  And ya...that wallet thing hurts!!  I had most of the 12's from a prior and current preamp but the 6a's were all a new experience.  Just picked up a 5998 from the 'bay.  Very excited to get that in and see if there really is magic in that tube.


----------



## younglee200

Thinking about selling the Crack amp w/ speedball to fund the SEX kit so that it could power both my speakers (emotiva) and my headphones........
  
 Any thoughts?


----------



## amcananey

How sensitive are your speakers?


----------



## younglee200

Not quite sure...
http://shop.emotiva.com/products/airmotiv4
  
 Can't seem to find it...
  
 I should also note that I also have the Dayton budget speakers for my Keyboard*


----------



## Loquah

younglee200 said:


> Thinking about selling the Crack amp w/ speedball to fund the SEX kit so that it could power both my speakers (emotiva) and my headphones........
> 
> Any thoughts?


 
  
 Great looking speakers! Only thing is they're active (self -amplified) so no S.E.X. required. My recommendation would be to keep the Crack for your HPs and buy the Emotiva speakers. You'll have to sort out your source switching then which is the problem I currently face - 1 output, but needing 2 (switchable) inputs for HP amps on one hand and active speakers on the other.


----------



## younglee200

Thanks for the advice,
  
 I wasn't sure whether it would benefit the speakers to have the SEX as a preamp or something, even though they are still active speakers.
  
 I have an Audio GD 3.3 as my source which just lets me switch between outputs at a push of a button, so that's not too much of a hassle 
  
 I'm going to be trying to my phone as a remote with the raspberry fi too so that should be cool.


----------



## Loquah

younglee200 said:


> Thanks for the advice,
> 
> I wasn't sure whether it would benefit the speakers to have the SEX as a preamp or something, even though they are still active speakers.
> 
> ...


 
  
 In my experience, the S.E.X. isn't quiet enough to act as a pre-amp for actives and you hear a lot of hum. It's no issue with headphones, but the actives amplify the hum along with the rest of the signal.


----------



## ffivaz

younglee200 said:


> Not quite sure...
> http://shop.emotiva.com/products/airmotiv4
> 
> Can't seem to find it...
> ...


 
  
 You could buy yourself a Bottlehead Quickie preamp. Quiet (battery powered) and fun to build !


----------



## Loquah

I'll be receiving one soon to use with active speakers. I'll post full details on the Bottlehead Comparison thread


----------



## olegausany

Quick question is 274b tube compatible with the Crack?


----------



## sjeffrey

It would seem like it is not.
 Refer to this thread for compatible tubes http://www.bottlehead.com/smf/index.php/topic,663.0.html


----------



## ngyu

On the Bottlehead site, it says it would be possible to modify the crack to run off of 6922 tubes, has anyone tried and is there a guide to convert from 12AU7 to 6922?


----------



## Doc B.

olegausany said:


> Quick question is 274b tube compatible with the Crack?


 
 No, Crack uses UF4007  ultra fast solid state rectifiers.


----------



## olegausany

doc b. said:


> olegausany said:
> 
> 
> > Quick question is 274b tube compatible with the Crack?
> ...



Thanks a lot for fast answer. 
This also should mean that 5AU4G will not work either since it also is recertifier type as much as I know


----------



## Nic Rhodes

the crack doesn't use any tube rectifier


----------



## Loquah

I think (big emphasis on THINK) that Doc is referring to the rectifiers in the under-chassis circuitry, not rectifier tubes.


----------



## skeptic

Correct - crack uses a diode bridge to turn ac -> dc.  See: http://en.wikipedia.org/wiki/Diode_bridge  When looking at the underside of the amp, they are the four little black components on the right side of the transformer.


----------



## trentrosa

Nice and simple solid state diode rectifier bridge. Keeps it clean


----------



## chadbang

Hello, I've become interested in purchasing a Bottlehead Crack, but I'm hesitant to pay up front and then wait for delivery. There was once a (well-known) amp builder who ran his business this way and wait for this amps grew longer....and longer.... until they exceeded a year and people began shouting "theft." My question is, why is Bottlehead, after several years of being in business, unable to stock sufficient material to avoid this waiting period? The price of the amp has risen to a price point that is no longer an insignificant amount of money, and the fear of a business suddenly going under makes paying upfront somewhat unattractive. My question is: Does this waiting period go in precise time segments, coinciding with regular shipments (say, of laser cut boards)? Or is it more random than that? Thanks for your help!


----------



## Nic Rhodes

i think it is merely the business model Bottlehead use to keep costs to a minimum. Nothing to worry about at all and despite my amp being at a rush period I thought delivery was swift and well done. There is nothing to worry about here, Bottlehead seems a good organisation.


----------



## chadbang

Well, that's good to know, Nic. Can you give me an approximation of the time from your order until it was shipped. 2,3,4 weeks?


----------



## Zashoomin

chadbang said:


> Well, that's good to know, Nic. Can you give me an approximation of the time from your order until it was shipped. 2,3,4 weeks?


 
 I would say anywhere from 2-8 weeks depending on what parts they are missing.


----------



## Nic Rhodes

without checking I would say 3 to 4 weeks but that was for the UK delivery and with all the customs surcharges / taxes also.


----------



## Loquah

I'd agree with all the above re shipping. You can always shoot them an email and ask if they're experiencing any backlog. 

FWIW they are great to deal with and seem to truly care about their community of customers. I don't see them going anywhere. 

Final point us that Crack is their top selling HP amp so if they have to wait for quantities before ordering parts (eg chassis plates) the Crack would be the one hitting those minimum numbers more quickly / regularly.


----------



## sjeffrey

chadbang said:


> Well, that's good to know, Nic. Can you give me an approximation of the time from your order until it was shipped. 2,3,4 weeks?


 

 You can check their delivery status page, http://www.bottlehead.com/et/deliverystatus.htm
 They only update it once or twice a week but it gives you an idea on how long it should take.
 They seem to be a bit longer now because they are in the process or just completed a massive group buy that happened about 2 months ago.


----------



## amcananey

Look, I don't love the way Bottlehead runs the order process, but I understand why they do it.

1. They don't pack and ship individual kits as order comes in (e.g., one Crack, then one S.E.X., then one Stereomour, then another Crack, then an Eros, then a Quickie, etc.). Instead, they pack kits in batches. One week they might pack 50 Crack kits, then the next week they pack 50 S.E.X. kits, then the week after that they pack 100 Quickie kits (I'm just using sample numbers, and they might pack more than 1 kit in a given week). This is obviously more efficient for them, since they can basically run an assembly line.

2. They take orders, then when they have a sufficient volume of orders, they place an order for parts. Then they wait for the parts to arrive. Some parts arrive sooner than others, and they can't ship the kits until they have ALL the parts. This basically keeps their working capital at close to zero, which helps keep down the price of the kits. But as a customer, it is annoying.

3. In terms of the amp builder who screwed his customers, if you're referring to who I think you you're referring to, then: (a) I think that was an unusual situation -- I believe there were external factors that played a role in that situation that are unlikely to affect anyone within Bottlehead, and (b) he was an amp BUILDER -- Bottlehead just sells kits. If you have problems like those that I suspect the amp builder had, then I can easily see how you could get behind on actually doing the work of building kits. But Bottlehead is a team, they can cover for eachother as needed (at least to a certain degree), and they aren't building amps, they are "just" selling kits. Yes, there is manual work involved (especially the brushing of the chassis plates), but it isn't on the same level as building an amp.

Again, I find the Bottlehead approach slightly irritating, but maybe we are all just spoiled by Amazon and next-day delivery and we should remember that Bottlehead's model wasn't all that unusual a couple of years ago...

Best regards,
Adam


----------



## skeptic

Chad - as you can see if you skim even a few pages of this thread, or the forums at bottlehead, Doc B and his team are in constant communication with their customer base - providing both prompt technical support and regular updates on when then next batch will ship.  Having purchased a couple of bh products now, I can assure you that there are absolutely no parallels between bottlehead's business model and the SP fiasco.  
  
 Frankly, as I assume you know as a long term member here, most of the highly recommended amps on head-fi have waiting lists, and all require payment up front.  This kit is well worth a few week wait.  Pull the trigger with confidence.


----------



## brunk

amcananey said:


> Again, I find the Bottlehead approach slightly irritating, but maybe we are all just spoiled by Amazon and next-day delivery and we should remember that Bottlehead's model wasn't all that unusual a couple of years ago...
> 
> Best regards,
> Adam


 
 This is so true. I find it irritating myself when people treat you as though you are a billion dollar company which has miles upon miles of warehouse inventory. Bottlehead's products are a niche product in a niche market. I am willing to accept a month of waiting, because I understand the difference. Plus, I appreciate the fact it's not a faceless company and Doc has a great sense of humor too. Heck, if you were to order all these parts yourself, it would probably take the same amount of time, and more money just in shipping costs alone. Sorry for the slight rant, but that last sentence struck a chord with me because several people have treated me as such.


----------



## Doc B.

There is an old saying - "good, fast, inexpensive - you can have two out of three." 
  
 We decided 19 years ago to concentrate on good and inexpensive - make the best sounding gear we could come up with for the price, work the business on a cash basis to keep the prices as low as possible, trim labor to the quick and to take pains to be very up front about the lead times of various products.  I can understand that some folks might think that is not the way that we should do business. However I have to weigh this against our current 20% growth rate which seems to indicate that some customers find it an acceptable approach. If fast is what is the priority over good or inexpensive there are certainly manufacturers out there who will have products in stock. 
  
 Since we've only been in the kit business for 19 years, we don't claim to know that much about it. We do know that we don't want to be responsible for making unhappy customers, and there is usually little to be gained by forming a relationship with someone who has preconceived dissatisfaction. But if you want a pretty nice sounding piece of gear that you can call your own and you have some patience we would love to create a kit for you.


----------



## Zashoomin

Doc's Kits are amazing.  Sometimes you might have to wait a little bit but they are well worth the wait.  If you ever buy a high end amp it is the same way.  You have to wait for it to be built and shipped and I am fine with that because the products are so good.  That is why I keep going back to Bottlehead to buy more stuff.   That and I like building them.  Also the manuals are so good I think that I sometimes buy the kit just for that.  
	

	
	
		
		

		
			





.  
  
 I know that the customer service has already been mentioned but I can also vouch that it is fantastic.  Every fast email responses and Doc is always very active on the Headfi and Bottlehead forums. My most favorite part about the service is that when you call them though you don't have to press 1 for more options.  It takes you directly to a human being.


----------



## NightFlight

I've never met any of the crew at BH. But I'd like to. Everything I've read and heard tells me they are sensible and good people. A rare thing.


----------



## palmfish

They love music and audio, and support head-fiers, thats for sure. Great hospitality too - they welcome visitors.


----------



## NightFlight

Is there a thread somewhere.. 'Crack OTL' mods for neophytes? I found the tube rolling on BH, which already has me rubbing my hands.


----------



## mithrandir38

Three weeks in and waiting for my Crack...I'm getting super-itchy to do some soldering!  Looking forward to it, Doc B!


----------



## JamieMcC

mithrandir38 said:


> Three weeks in and waiting for my Crack...I'm getting super-itchy to do some soldering!  Looking forward to it, Doc B!


 
 I have been waiting about the same, I think waiting for the kit is all part of the experience it does give you plenty of time to do some research on tubes solder tools finishes etc! 
  
 And as one of my favourite adds says
  
 Good things come to those who wait
  
 Tick followed tock followed tick


----------



## Mahdi8

I've just build the crack last week end and really happy with it? anyone know what's the stock tubes called? I'm pretty happy with the stock tubes and want to buy some spares.


----------



## Mahdi8

BTW both of them doesn't have any marking so couldn't figure it out by myself


----------



## audiowize

mahdi8 said:


> BTW both of them doesn't have any marking so couldn't figure it out by myself


 
 It's right on the product page, about 1/3 of the way down:
http://www.bottlehead.com/store.php/products/crack-otl-headphone-amplifier-kit
  
 The tube lottery is still in play.  We send out a lot of clear tops, a few mullard, 5963's, etc for the 9 pin tube.  The octal tube is nearly always a 6080 of some variety.


----------



## Mahdi8

so basically since there is no marking on the tubes I can't tell what's the make of the tubes? Sorry I'm a real beginner on tube selection. and so many types it confuses me. Most of recommendation tube tread seems out of date and their prices are much more than they used to now. for under $50 what's the recommended upgrade for the stock power and input for a flat frequency, largest detail and most sound stage? or I have to spend up to $100 or more?


----------



## Mahdi8

BTW is 6n8s russian tube with black plate any good for input tube?


----------



## brunk

mahdi8 said:


> so basically since there is no marking on the tubes I can't tell what's the make of the tubes? Sorry I'm a real beginner on tube selection. and so many types it confuses me. Most of recommendation tube tread seems out of date and their prices are much more than they used to now. for under $50 what's the recommended upgrade for the stock power and input for a flat frequency, largest detail and most sound stage? or I have to spend up to $100 or more?


 
 For the input tube, 12AU7 RCA cleartop (organ stock), and for power tube I would stick with the 6080 variant.


----------



## Aeolus Kratos

mahdi8 said:


> so basically since there is no marking on the tubes I can't tell what's the make of the tubes? Sorry I'm a real beginner on tube selection. and so many types it confuses me. Most of recommendation tube tread seems out of date and their prices are much more than they used to now. for under $50 what's the recommended upgrade for the stock power and input for a flat frequency, largest detail and most sound stage? or I have to spend up to $100 or more?


 
  
 I have great result with the RCA Clear-top ( relabeled by Conn ) and the GEC 6AS7G Brown base ( driving HD650 ). If you want details and big sound stage, don't look else where but the RCA Clear-tops, you can get them at a cheap price is also a plus.


----------



## Loquah

My favourite low price 6080 is the Mullard 6080WA. It's a little warm, but has a great soundstage and pairs beautifully with 12AU7 Cleartop


----------



## Aeolus Kratos

My new input tube for the Crack... 
	

	
	
		
		

		
			




  

  

  

  
 This is one of, if not the most glorious input tubes I have ever seen. It is also the biggest and best sounding input tubes I've tried in the Crack. I have to admit that I initially doubt that there is a noticeable difference, but I was wrong. The sound is simply amazing.
  
 The only little problem is...now my Crack looks a bit weird, because the 'monster' input tube is even bigger than my GEC brown base power tube


----------



## younglee200

Where's the cheapest place to order the RCA Clear-top?
  
 I'm interested in trying one.
  
 Do I need to purchase another tube to pair it with?


----------



## caracara08

aeolus kratos said:


> My new input tube for the Crack...
> 
> 
> 
> ...


 
  
 Sorry, Im not too familiar with tubes, what is that tube and adapter? price?


----------



## FlySweep

> Originally Posted by *Aeolus Kratos* /img/forum/go_quote.gif
> 
> 
> Spoiler: Warning: Spoiler!
> ...


 
  
 Very nice!  Psvane 6SN7, I presume?  I'm, by and large, done with tube rolling for my Crack.. but I'd consider grabbing that beauty!


----------



## drizek

Got my kit yesterday and had so much fun building it. It was my first headphone-related DIY project and it was awesome. I spent 7 hours straight doing it; I was originally planning on doing it over two or three days but I just couldn't tear myself away. I built the base model and will be adding in the speedball in a couple weeks.
  
 As far as I can tell, everything works properly. The voltages are within the right range, although I was a bit worried about the fact that the resistance on the left/right inputs is about 10ohms apart (95 versus 105). Is that going to be something I will hear, and is it normal to have such variations or is it symptomatic of an error on my part?
  
 I can't actually listen to it yet because I realized I don't actually own RCA cables (yet)


----------



## ben_r_

drizek said:


> I can't actually listen to it yet because I realized I don't actually own RCA cables (yet)


 
 Oh that has got to hurt!


----------



## amcananey

LOL. I had to laugh at that one, too. I would run out and buy a pair from Radio Shack or Walmart or wherever, just to get myself up and running. Congrats on the build, you won't be disappointed!


----------



## brunk

amcananey said:


> LOL. I had to laugh at that one, too. I would run out and buy a pair from Radio Shack or Walmart or wherever, just to get myself up and running. Congrats on the build, you won't be disappointed!


 
 Hehe yeah that reminds me when I make cables and sometimes forget to put the housing on the cable before i solder the wires lol!


----------



## drizek

The plan is to build a matching set of cables for AC/RCA/Sennheiser.
  
 I never anticipated that someday I'd be living in an apartment without RCA cables; they are supposed to be ubiquitous.
  
 Another voltage question: the final check in the manual says to measure the voltage on power on of the powered L/R channels. It says it should go up to 9V then drop to 0. On mine it goes all the way up to 12V before dropping. Is that too high or within the correct range? i did not find any other voltage/resistance issues (other than the L/R resistance mismatch), so I'm not really sure why it is going up to 12 instead of 9.


----------



## brunk

drizek said:


> The plan is to build a matching set of cables for AC/RCA/Sennheiser.
> 
> I never anticipated that someday I'd be living in an apartment without RCA cables; they are supposed to be ubiquitous.
> 
> Another voltage question: the final check in the manual says to measure the voltage on power on of the powered L/R channels. It says it should go up to 9V then drop to 0. On mine it goes all the way up to 12V before dropping. Is that too high or within the correct range? i did not find any other voltage/resistance issues (other than the L/R resistance mismatch), so I'm not really sure why it is going up to 12 instead of 9.


 
 far as i know, as long as it goes to 0 there shouldn't be an issue.


----------



## Loquah

brunk said:


> far as i know, as long as it goes to 0 there shouldn't be an issue.


 
  
 That's my understanding too. There are always variations on the measurements so no doubt those variations carry through to the HP socket also.


----------



## W0lfd0g

Hi there
  
 I have a NOS NIB Tung Sol black glass black plate 12AU7 I'm selling (ordered six weeks ago, but just arrived) - Please see my signature for link to listing (sorry Lachlan - I need to sell). 
  
 Also the following:
 Matched pair NOS NIB 6AS7G RCA JAN
 NOS NIB Tung Sol clear top 12AU7A
 Tung Sol clear top 12AU7 (used but strong, printed marking rubbed off)
3 x used but strong Tungsram E80CC (white box) - Only 1 left
 Quite a few Baldwin branded but Japanese made 12AU7 tubes (white box, lightly used but strong)
 Matched pair Mullard ECC82 (Mitcham 1960) wrinkled glass (white box, lightly used but strong)
 RCA 5963 (driver tube for Crack) long black laddered plate with top D getter, 1956 (NOS, white box)
  
 That's it gents and I'm out of tubes for the Crack.
  
 Let me know if you are interested in any or all of the above.  I am in the middle of a major depressive episode, agoraphobic, unable to work and out of money, so you would be doing me a favour.
  
 Cheers and sorry for the sob story.
  
 Nathan


----------



## drizek

... and I just shocked myself. 
  
 Pretty sure I touched one of the live AC leads on the power switch. 
  
 Tip: don't play with this thing while it is still plugged in. 
	

	
	
		
		

		
		
	


	



  
 I actually feel really stupid right now. Glad I didn't die.


----------



## Loquah

drizek said:


> ... and I just shocked myself.
> 
> Pretty sure I touched one of the live AC leads on the power switch.
> 
> ...


 
  
 I'm glad you didn't die too!!
  
 Very important to take lots of care when testing the circuit and always unplug the cable from the power socket (i.e. mains power supply) before doing anything "under the hood". A friend of mine fried himself on a capacitor even after unplugging the unit for a few minutes (the circuit was faulty and didn't drain the caps) so beware of loaded capacitors to - a rubber handled set of pliers can serve as a good guinea pig for live current.


----------



## mcandmar

Funny when i seen that pic of the open side i was going to post and say for god sake be careful around that amp.  Then decided not to state the obvious...


----------



## olegausany

w0lfd0g said:


> Hi there
> 
> I have a NOS NIB Tung Sol black glass black plate 12AU7 I'm selling (ordered six weeks ago, but just arrived) - Please see my signature for link to listing (sorry Lachlan - I need to sell).
> 
> ...



By any chance any of the 12AUs sound exactly as Mullard E80CC?
Why am I asking cause I just got Simens 12AU which does exactly that


----------



## captslow

Just read through this thread... The Crack just made it to the top of my want list. It is unbelievably cheap and looks like a fun project, may have to build it and the reduction for my turntable.


----------



## Bimbleton

Painting & varnishing the wood to make it look nice... does that have to be done before or after assembly?


----------



## Loquah

simanick said:


> Painting & varnishing the wood to make it look nice... does that have to be done before or after assembly?


 
  
 It's probably easier after assembly because gluing will be tricky once there's varnish in the joints.
  
 I've done the stain and varnish on both of mine after assembly with no problems.


----------



## drizek

loquah said:


> I'm glad you didn't die too!!
> 
> Very important to take lots of care when testing the circuit and always unplug the cable from the power socket (i.e. mains power supply) before doing anything "under the hood". A friend of mine fried himself on a capacitor even after unplugging the unit for a few minutes (the circuit was faulty and didn't drain the caps) so beware of loaded capacitors to - a rubber handled set of pliers can serve as a good guinea pig for live current.


 
  
 It was a bit ambiguous in the manual, so I figure I will ask: the capacitors in the Crack will be drained automatically by resistors after a few minutes, right? I'm not an electrical engineer or anything so I don't understand the diagrams intuitively, but my goal is to actually know what all the bits and pieces do before I go ahead and upgrade it with a speedball and make it even more complex.
  
 Anyway, I couldn't stand not being able to listen to it due to my lack of possession of RCA cables, so I unplugged my subwoofer and used that cable to get one channel connected. At first I was concerned that the volume was really low, then I realized that I had plugged it in to the other channel, and all the volume I was getting was actually crosstalk 
	

	
	
		
		

		
		
	


	




. How much of that is normal for this amp? At maximum volume, the crosstalk alone reaches a comfortable listening level.
  
 Edit: I do enjoy taking pictures of this thing,


----------



## Loquah

drizek said:


> It was a bit ambiguous in the manual, so I figure I will ask: the capacitors in the Crack will be drained automatically by resistors after a few minutes, right? I'm not an electrical engineer or anything so I don't understand the diagrams intuitively, but my goal is to actually know what all the bits and pieces do before I go ahead and upgrade it with a speedball and make it even more complex.
> 
> Anyway, I couldn't stand not being able to listen to it due to my lack of possession of RCA cables, so I unplugged my subwoofer and used that cable to get one channel connected. At first I was concerned that the volume was really low, then I realized that I had plugged it in to the other channel, and all the volume I was getting was actually crosstalk
> 
> ...


 
  
 Yes, the resistors will drain the capacitors fairly quickly once power is disconnected.
  
 I don't fully understand your setup with the woofer cable, but there is very little crosstalk (i.e. not noticeable even with excellent cans) in the normal setup.


----------



## drizek

loquah said:


> Yes, the resistors will drain the capacitors fairly quickly once power is disconnected.
> 
> I don't fully understand your setup with the woofer cable, but there is very little crosstalk (i.e. not noticeable even with excellent cans) in the normal setup.


 
 It is just a single RCA cable, so I only get one channel. I initially had it hooked up to the wrong channel, so the sound coming into my headphones on the right channel was actually all from crosstalk from the left channel. 
  
 I guess I'll have to go through and see where this might be coming from.


----------



## sjeffrey

loquah said:


> Yes, the resistors will drain the capacitors fairly quickly once power is disconnected.
> 
> I don't fully understand your setup with the woofer cable, but there is very little crosstalk (i.e. not noticeable even with excellent cans) in the normal setup.


 
  
 This confuses me too.  I understand that you took just 1 cable so you have either a left or a right plugged in.
 The only thing I can think of is either your cable was carrying the crosstalk and not the crack generating it(?)
 Or, you have something wrong with your wiring and 1 channel is not working and cranking volume up allowed you to hear the music in other channel.  Have you tried plugging the one cable in each channel?
  
 EDIT: Have any component cables around?  That would work just as good as your subwoofer cable


----------



## drizek

The other complication is that my HD 580 cable's left channel is gone, so I am waiting on a new pair of Sennheiser cables before I can actually listen in stereo. My actual setup was Left Out of DAC, Left In to Crack (with the woofer cable), then the headphones plugged in, but with only the Right side functioning. So the sound I was hearing through the Right driver was actually going into the Crack through the Left channel. 
  
 And I couldn't find any component cables either. I made a point of making my home theater system 100% HDMI 1.4.


----------



## sjeffrey

drizek said:


> The other complication is that my HD 580 cable's left channel is gone, so I am waiting on a new pair of Sennheiser cables before I can actually listen in stereo. My actual setup was Left Out of DAC, Left In to Crack (with the woofer cable), then the headphones plugged in, but with only the Right side functioning. So the sound I was hearing through the Right driver was actually going into the Crack through the Left channel.
> 
> And I couldn't find any component cables either. I made a point of making my home theater system 100% HDMI 1.4.


 
 LOL, this has got to be the sketchiest setup so far.  And you are telling us you got shocked?  No!, really?? 
	

	
	
		
		

		
		
	


	



 Just messing with you.  I'm sure you'll enjoy the crack once you get RCAs and working headphone cables


----------



## Loquah

drizek said:


> The other complication is that my HD 580 cable's left channel is gone, so I am waiting on a new pair of Sennheiser cables before I can actually listen in stereo. My actual setup was Left Out of DAC, Left In to Crack (with the woofer cable), then the headphones plugged in, but with only the Right side functioning. So the sound I was hearing through the Right driver was actually going into the Crack through the Left channel.
> 
> And I couldn't find any component cables either. I made a point of making my home theater system 100% HDMI 1.4.


 
  
 Not sure what would have caused the cross-talk, but I just checked my Crack with my Beyer T1s and there was no audible cross-talk and listening levels. I couldn't turn a channel up to full volume without risking damage to my cans.


----------



## amcananey

sjeffrey said:


> LOL, this has got to be the sketchiest setup so far.  And you are telling us you got shocked?  No!, really?? :blink:
> Just messing with you.  I'm sure you'll enjoy the crack once you get RCAs and working headphone cables




Word. That is seriously the funniest, most effed-up way to test the Crack I've ever heard of. Next thing I know you'll tell us your source only outputs a signal on the right channel...except when there is a Tuesday with a full moon, in which case it is reversed...


Adam


----------



## palmfish

Oh, come on...ease up a bit everyone.

You remember how excited you were to power it up and listen after the build was done. He's only doing what each of us would do given the same circumstances - which admittedly, are pretty hilarious... 

I must say drizek, you do take really good photos!


----------



## drizek

I couldn't help myself. It was sitting right next to me all day, glowing, begging to be listened to.


----------



## amcananey

I wasn't making fun of him. I was laughing WITH him, not AT him, and I'm glad he's still with us after that scare!


----------



## drizek

Besides, after what you did to your Crack, I think you've waived the right to call anybody else's ridiculous.


----------



## palmfish

Too - shay!


----------



## Aeolus Kratos

caracara08 said:


> Sorry, Im not too familiar with tubes, what is that tube and adapter? price?


 
 The orange-base input tube is Psvane CV131 Mark II and the power tube is GEC 6AS7G Brown base. Also, the tube adapter is a Chinese adapter which I purchased from Ebay.
  
 Cheers,
 Kratos.
  


flysweep said:


> Very nice!  Psvane 6SN7, I presume?  I'm, by and large, done with tube rolling for my Crack.. but I'd consider grabbing that beauty!


 
 Yes, you're right 
	

	
	
		
		

		
			




  
 There are many people who are willing to pay hundreds of dollars just to make their amps look more awesome, so don't be afraid to pull the trigger, I guarantee you that your Crack will look much better after installing this tube, not to mention how it will sound


----------



## brunk

drizek said:


> Besides, after what you did to your Crack, I think you've waived the right to call anybody else's ridiculous.


 
 Hah! 
	

	
	
		
		

		
		
	


	




 There's so many puns waiting to be had with that statement too!


----------



## amcananey

drizek said:


> Besides, after what you did to your Crack, I think you've waived the right to call anybody else's ridiculous.




Ahhhhh, but you see, my Crack isn't ridiculous. 




I left ridiculous behind a looooooooong time ago. I am fully into absurd territory.


----------



## DefQon

> ... absurd territory.


 
  
 More like insanely overkill territory. You may as well start de-soldering all the caps in your house appliances and attach those fist sized motor run caps for better transients and power deliver. Might make your fridge run colder or your microwave a faster heater.


----------



## Armaegis

amcananey said:


> Ahhhhh, but you see, my Crack isn't ridiculous.
> 
> 
> 
> ...


 
  
 Oh come now. You haven't even attached the lightning rods yet!


----------



## amcananey

armaegis said:


> Oh come now. You haven't even attached the lightning rods yet!



 


That's because thus far I haven't figured out a way to rig the rocket booster packs such that they will enable the Crack to maintain a constant velocity of 88 mph. With variable thrust and acceleration, it is still too difficult to time the lightning strike just right...


----------



## Armaegis

Physical propellant? Oh come now, we both know a magnetic levitation system is the best way to provide a constant speed *and *voltage for those tubes...


----------



## DefQon

Does it attract women that is the question?


----------



## amcananey

defqon said:


> Does it attract women that is the question?



 


Yes, but it turns out she was my mother.











[Please tell me everyone is getting the BTTF references, otherwise I will sound like a complete perv...]


----------



## palmfish

defqon said:


> Does it attract women that is the question?




You're joking, of course. It is a well known fact that the only thing in the universe that turns a woman colder than sci-fi/fantasy role playing games is tube amplifiers and flux capacitors.








(My hommage to the BTTF references)


----------



## amcananey

Calvin Klein underwear, on the other hand, is a major turn-on. Especially if she thinks you're Calvin Klein...


----------



## palmfish

^^
You are a little too well versed in BTTF trivia. Disturbingly well versed.


----------



## DefQon

I'm in tears.


----------



## JamieMcC

Whoohooo, just received shipping notification for me Crack.


----------



## Loquah

Happy times!


----------



## Mahdi8

is rca clear top 12au7a compatible with the crack? is it the same with normal 12au7?


----------



## W0lfd0g

12AU7A is an updated 12AU7 - Entirely compatible.


----------



## mithrandir38

jamiemcc said:


> Whoohooo, just received shipping notification for me Crack.


 me too, dude! arriving Monday! just need to buy a couple tools to make things go a little smoother


----------



## drizek

sjeffrey said:


> LOL, this has got to be the sketchiest setup so far.  And you are telling us you got shocked?  No!, really??
> 
> 
> 
> ...


 
  
 Yup, just got all the parts in and got it all set up. I even closed off the front side so I won't get shocked again.
  
 Whatever issues I was having before are now completely gone. I've only been listening for a few minutes, but it sounds absolutely amazing so far.


----------



## JamieMcC

While on the subject of tubes I won a assorted lot of nine tubes on ebay the other day for $10.5 amongst them were three 12au7, but only one was listed as a 12au7 type so looking forward to trying them.
  
 12au7 Mullard uk made (the one you could see in the sellers pic).
  
 12au7something?  Mullard with box plates, uk made
 (very hard to read as most of the white print had come off I had to get the magnifying glass out)
  
 12au7something? Sylvania with long black plates, again I had the magnifying glass out.
  
 Other than having most of the print worn off two of the tubes they all look to be in good condition.


----------



## JamieMcC

mithrandir38 said:


> me too, dude! arriving Monday! just need to buy a couple tools to make things go a little smoother


 
  
 I should see mine in about 7-10 days by the time it arrives in the UK and clears customs, which is good timing as am taking the family away for a weeks holiday during the school half term.
  
 I have been pondering over having a go at something like this in the pics below for the top plate.
  
 I would be fine doing the swirl marks etc and a single colour but getting that blended sunburst effect would be a challenge on something the size of the Bottlehead Cracks top plate and more airbrush territory which I am hopeless at.
  
 The effect is essentially ground metal plate covered with clear etch primer and adhesion promoter, then a inter clear coat to fill the grind marks smooth followed by a candy pigment based paint, colour of choice (a coloured transparent paint which allows the light to pass through it and be reflected back out by the ground metal underneath which gets the nice effects). Followed by more layers of clear coat to get the depth of shine.
  
  

  

  

  
 I also have a bit of thin carbon fibre flat plate which I could cut out to match and go over the alloy top plate which might also look a bit different.
  
 
  
 I tried experimenting with dying thin strips of wood the thought was to laminate them up laid vertically for a multi coloured stripped base. However I am finding it hard to get the aniline dye to penetrate the wood fully think I might have to dye them under pressure or vacuum to work and that would take a lot of messing about, so perhaps I will save it for a later follow on project and I would get to enjoy the Crack sooner.
  
 On the other hand  I also like the clean finished Alder and painted top which has a nice classic look.
  
 Edit
  
 Thinking about it I perhaps I have been suffering from some sort of Pre-Crack builders syndrome! Something to do with the wait the symptom creep up slowly unnoticed on you during those long days and nights waiting for your crack to arrive.


----------



## ngyu

jamiemcc said:


> I should see mine in about 7-10 days by the time it arrives in the UK and clears customs, which is good timing as am taking the family away for a weeks holiday during the school half term.
> 
> I have been pondering over having a go at something like this in the pics below for the top plate.
> 
> ...


 
  
 nice materials, carbon fiber would be sick. i wish i had access to those kinds of materials.


----------



## drizek

I get microphonics in the right channel. Does that mean I have a bad tube?


----------



## brunk

drizek said:


> I get microphonics in the right channel. Does that mean I have a bad tube?


 
 Is this while playing music, or just touching it? It does sound like a bad tube if it's just the right channel. If it's a new tube you may just need to burn it in for 100 hours or so.


----------



## drizek

Just by touching it, and it is only on the right channel.
  
 I'm hearing some distortion as well during some bass notes, in both channels. (Intro by The XX causes it a lot, for example).
  
 It is still new though, so I'll let it run for a day or two to see if it goes away.


----------



## brunk

drizek said:


> Just by touching it, and it is only on the right channel.
> 
> I'm hearing some distortion as well during some bass notes, in both channels. (Intro by The XX causes it a lot, for example).
> 
> It is still new though, so I'll let it run for a day or two to see if it goes away.


 
 It may not be an issue if its only audible while touching it. The distortion could also be from clipping in the track, thanks to the ongoing loudness wars. Yeah, give it atleast a couple more days and see if the problem diminishes. Most tubes are going to have this issue to some degree, some worse than others. You can look into damping the tube with tube dampers, tube shields, or try reseating the tube.


----------



## Jmstrmbn

drizek said:


> Just by touching it, and it is only on the right channel.
> 
> I'm hearing some distortion as well during some bass notes, in both channels. (Intro by The XX causes it a lot, for example).
> 
> It is still new though, so I'll let it run for a day or two to see if it goes away.


 
  
 I have heard that song through my system and don't get any distortion so we can rule out crappy mastering.


----------



## NightFlight

loquah said:


> That's my understanding too. There are always variations on the measurements so no doubt those variations carry through to the HP socket also.




Is this a power on DC offset? If so best practice would be to let the amp warm up without headphones connected. I mean, I do this already since I won't risk cooking my HD800's. I no longer even leave them plugged in un-attended. This goes double for an amp with 0 protection.


----------



## Loquah

nightflight said:


> Is this a power on DC offset? If so best practice would be to let the amp warm up without headphones connected. I mean, I do this already since I won't risk cooking my HD800's. I no longer even leave them plugged in un-attended. This goes double for an amp with 0 protection.


 
  
 I've never heard of anyone destroying headphones with a Bottlehead amp startup, but it's always good to be safe.


----------



## NightFlight

loquah said:


> I've never heard of anyone destroying headphones with a Bottlehead amp startup, but it's always good to be safe.





The majority of amps likely have some offset at startup. I'm not centering out BH in any way. IMHO its better to wear out the TRS jack.


----------



## brunk

You could implement a soft start circuit if you're worried about it too.


----------



## NightFlight

nah, I don't even have a power switch. I cooked mine while building, so I bypassed it.


----------



## brunk

nightflight said:


> nah, I don't even have a power switch. I cooked mine while building, so I bypassed it.


 
 Please tell me you have it fused. If you don't that is a fire waiting to happen, seriously!


----------



## Loquah

nightflight said:


> The majority of amps likely have some offset at startup. I'm not centering out BH in any way. IMHO its better to wear out the TRS jack.


 
  
 Oh sorry. I realised you weren't targeting BH in particular. My direct reference to BH was more a case of sticking just to what I'm familiar with and not making a big sweeping (and potentially highly inaccurate) statement.


----------



## Loquah

brunk said:


> Please tell me you have it fused. If you don't that is a fire waiting to happen, seriously!


 
  
 +1,000,000
  
 The switches are really cheap from any electronics store and worth replacing. As brunk said, hopefully you have got the fuse incstalled (i.e. not bypassed) in the IEC power socket


----------



## NightFlight

brunk said:


> Please tell me you have it fused. If you don't that is a fire waiting to happen, seriously!





Yes, its fused.


----------



## brunk

nightflight said:


> Yes, its fused.


 
 OK good. You had me concerned for a minute there!


----------



## NightFlight

Can anyone point me to a good thread on mods/component upgrades? while I like the stock crack, its a bit loose in the bottom. I'm starting to peruse tubes on flea bay, but looking to try out some nicer caps or resistors while I wait for my speedball kit to get packed and shipped.


----------



## drizek

nightflight said:


> nah, I don't even have a power switch. I cooked mine while building, so I bypassed it.


 
 Aren't you worried about your tubes clogging up burning out?


----------



## NightFlight

Well, no. I unplug it when not in use. And the tubes are relatively cheap stock ones. I have pairs for my Lyr which sell used for more than the value of the crack.


Hoping a nice 5998 will open the crack up a bit more.


----------



## Loquah

nightflight said:


> Can anyone point me to a good thread on mods/component upgrades? while I like the stock crack, its a bit loose in the bottom. I'm starting to peruse tubes on flea bay, but looking to try out some nicer caps or resistors while I wait for my speedball kit to get packed and shipped.


 
  
 Check out the Bottlehead Forums (http://www.bottlehead.com/smf/index.php), specifically the "Crack" area. There's plenty of good mod discussion over there, but consensus is that the Speedball is easily the best bang-for-buck upgrade whereas caps and stuff are more fine tuning the sound signature. I guess the one high value upgrade you could try would be to upgrade the power caps like amcananey (not that you have to go as far as he did!)


----------



## Aeolus Kratos

nightflight said:


> Well, no. I unplug it when not in use. And the tubes are relatively cheap stock ones. I have pairs for my Lyr which sell used for more than the value of the crack.
> 
> 
> Hoping a nice 5998 will open the crack up a bit more.


 
 Yes, a nice 5998 will definitely do open the Crack up. It gives a bigger holographic sound stage, bring mid a bit more forward, and more sparkle in treble 
	

	
	
		
		

		
		
	


	



  
 But I honestly recommend you that the speedball is the best upgrade you can have for your Crack. Get it first, then go for the tubes.


----------



## drizek

On the subject of not having the headphones plugged in, on the Bottlehead forum there is a recommendation that the two unused prongs on the headphone jacks be wired to ground (picture in the link) to keep startup voltage at 0 (with no headphones plugged in). 
  
 http://www.bottlehead.com/smf/index.php/topic,2946.0.html


----------



## drizek

So even after a couple days of burn in, I still get a lot of distortion from my amp. Is it time to call up Bottlehead and ask for a replacement tube, or is there something else that could be wrong with it?


----------



## brunk

drizek said:


> So even after a couple days of burn in, I still get a lot of distortion from my amp. Is it time to call up Bottlehead and ask for a replacement tube, or is there something else that could be wrong with it?


 
 Check over your grounding


----------



## lextek

drizek said:


> So even after a couple days of burn in, I still get a lot of distortion from my amp. Is it time to call up Bottlehead and ask for a replacement tube, or is there something else that could be wrong with it?




You might want to post this question on the forum at Bottlehead.com. Very, helpful folks there too. When I built mine had no noise so I don't think it will change with burn-in.


----------



## drizek

I've doen all the multimeter checks and they're all fine. Do you mean resolder?


----------



## sjeffrey

drizek said:


> I've doen all the multimeter checks and they're all fine. Do you mean resolder?


 

 It's a good idea to have spares of both tubes, that way you can easily figure out if it's a tube problem or not.
 If the noise is only when you tap on the tube then it's probably tube but you also said that some bass notes cause the problem so I would make sure all you solders are good.


----------



## NightFlight

drizek said:


> I've doen all the multimeter checks and they're all fine. Do you mean resolder?




Grainger has a sticky thread at the top of the Crack forum at BH. A solid breakdown for ground checks. Here... I'll fetch it....

http://www.bottlehead.com/smf/index.php/topic,4812.0.html

I had heavy distortion at the outset, but mine disappeared with burn/break-in.


----------



## drizek

Thanks NightFlight.
  
 There is one solder joint that I know is not that great. I was planning on fixing it when I did the speedball installation.


----------



## lugnut

nightflight said:


> Well, no. I unplug it when not in use. And the tubes are relatively cheap stock ones. I have pairs for my Lyr which sell used for more than the value of the crack.
> 
> 
> Hoping a nice 5998 will open the crack up a bit more.


 
 Would you mind to comment a little on how the Crack vs Lyr sounds with the HD800 ?  Thanks


----------



## Aeolus Kratos

Here comes one of the hardest headphones to drive on planet


----------



## Armaegis

I think I tried that combo a long time ago but nothing sticks out in my memory...


----------



## Mahdi8

That looks sweet how does it sound?


----------



## Aeolus Kratos

armaegis said:


> I think I tried that combo a long time ago but nothing sticks out in my memory...


 
 Perhaps that is because there was not 'something' in this combo which made you remember 
  


mahdi8 said:


> That looks sweet how does it sound?


 
 The most noticeable thing is that the K340 + Crack combo has an amazing sound stage, very holographic and spacious. The treble has great sparkle, the mid is neutral, a little bit cold but somehow smoother than K701. But the main weakness is its bass, I think the Crack can't drive the K340 to a decent level, the bass body is still not full, sub bass presents, but mid bass is not punchy also.
  
 The combo is great for classical and acoustic, but it's definitely not suitable for basshead or those who love pop, rock or anything contains bass


----------



## DefQon

jamiemcc said:


> I also have a bit of thin carbon fibre flat plate which I could cut out to match and go over the alloy top plate which might also look a bit different.


 
  
 I was and am still thinking of carbon fibering the top aluminium plate, but I'm not sure the carbon fiber decal can tolerate a few hours or constant daily use of on and off 40-55'C. Please do let me know if you pull it off on yours.
  
 @K340 user: Bass depends on what K340 version you got, there are two version bass light and bass heavy.


----------



## HolyCheese

Is there anyway to lower the gain on this amp? It's hard to set it at low levels without volume imbalance.
  
 I really wonder why they make all amps so extremely powerfull. I also have an O2 with the lowest gain possible and it doesn't get past 15%.
 I have a feeling that it's best that average listening level is around 50% of volume on the knob.


----------



## Aeolus Kratos

holycheese said:


> I have a feeling that it's best that average listening level is around 50% of volume on the knob.


 
  
 My opinion is that the best listening level is just around 30-35% of volume ( the knob is at about 9-10 o' clock position )
  
 50% of volume to reach preferable listening level is too much for me.


----------



## amcananey

Yes. Sort of. Use these: http://www.amazon.com/Harrison-Labs-Line-Level-Attenuator/dp/B0006N41B0/ref=sr_1_1?ie=UTF8&qid=1383060429&sr=8-1&keywords=harrison+labs+12db+attenuators

Don't bother going for anything less than 12dB, you won't notice the difference.


----------



## skeptic

holycheese said:


> Is there anyway to lower the gain on this amp? It's hard to set it at low levels without volume imbalance.
> 
> I really wonder why they make all amps so extremely powerfull. I also have an O2 with the lowest gain possible and it doesn't get past 15%.
> I have a feeling that it's best that average listening level is around 50% of volume on the knob.




A lot of folks will recommend the inline attenuators you can buy on amazon. A nice alternative is the addition of 4 resisters in series with, and then shunting from the input of your pot to ground, as explained here:http://www.goldpt.com/mods.html

For your o2, stock is set to 2.5x/6.5x gain. If you want to be able to use it with iems, you can easily alter one of these to unity gain by snipping 2 resisters. Also helps avoid the known clipping issues with the o2. Hope this helps!


----------



## sjeffrey

holycheese said:


> Is there anyway to lower the gain on this amp? It's hard to set it at low levels without volume imbalance.
> 
> I really wonder why they make all amps so extremely powerfull. I also have an O2 with the lowest gain possible and it doesn't get past 15%.
> I have a feeling that it's best that average listening level is around 50% of volume on the knob.


 
 Why not do this taken from the Crack FAQ over at BH forums 
 ********************
*3.  I can barely turn my Crack up at all before it's far too loud, what do I do?*

 Remove the white wire from the left RCA jack at the rear of the chassis.  Solder in a 270K resistor to the solder cup on that jack, solder the white wire to the other end.  Repeat this for the red wire with another 270K resistor.  This will give you about a -10dB pad at the input.  If you still have the issue, try 470K instead.  The wattage of these resistors isn't all that important, anything between 1/16 Watt and 1/2 Watt is reasonable, with metal film and carbon film types being most recommended.
 ********************


----------



## skeptic

resisters in series will pad volume but the goldpoint method does the same while preserving the input impedance.


----------



## Bimbleton

Just ordered my first Crack kit. Had a question -- I would like to use braided/shielded RCA cables to reduce the possibility of "hum" that many users reported. Unfortunately since I'm totally new at this, not 100% what to buy. Can someone send me a link to some cheap shielded RCA cables that will replace that braided one in the Crack?
  
 Also, any suggestions on easy, cheap first-built improvements?


----------



## ben_r_

drizek said:


> On the subject of not having the headphones plugged in, on the Bottlehead forum there is a recommendation that the two unused prongs on the headphone jacks be wired to ground (picture in the link) to keep startup voltage at 0 (with no headphones plugged in).
> 
> http://www.bottlehead.com/smf/index.php/topic,2946.0.html


 

 That is very interesting and makes sense. After added a Speedball the startup voltage will actually go upwards of 10-20 volts before it quickly drops back down to 0v. I have verified this on two Cracks with Speedball and seen other experience it as well around the net. What I also found interesting is that post you found on the Bottlehead forum is from the middle of 2012, and now were sitting at the end of 2013 and as far as I know the Crack manual still has not been modified to include the grounding of the left and right channels at the TRS jack. This "mod" is even a sticky in their Crack forum section. I wonder why they havent done that yet.
  
 Has anyone out there tried grounding them?


----------



## ffivaz

simanick said:


> Just ordered my first Crack kit. Had a question -- I would like to use braided/shielded RCA cables to reduce the possibility of "hum" that many users reported. Unfortunately since I'm totally new at this, not 100% what to buy. Can someone send me a link to some cheap shielded RCA cables that will replace that braided one in the Crack?
> 
> Also, any suggestions on easy, cheap first-built improvements?


 
  
 If you correctly braid the three wires from the RCA inputs to the volume pot, you won't have any kind of hum. The noise rejection from correctly braided wires is in fact quite astounding.


----------



## skeptic

simanick said:


> Just ordered my first Crack kit. Had a question -- I would like to use braided/shielded RCA cables to reduce the possibility of "hum" that many users reported. Unfortunately since I'm totally new at this, not 100% what to buy. Can someone send me a link to some cheap shielded RCA cables that will replace that braided one in the Crack?
> 
> Also, any suggestions on easy, cheap first-built improvements?


 
  
 Welcome to the thread Simanick!  There have been very occasional reports of hum, but these are almost always due to: (i) an imperfect tube, (ii) use of tube adapters to run 6sn7's (which I personally recommend against) or (iii) an attempt to use stranded hookup wire or some other such misguided departure from the stock build.   
  
 When you say RCA cables - are you talking about the internal hookup wire that runs from the rca inputs to the pot?  If so, I would echo ffivaz and encourage you to just follow the directions and use the solid core wire provided.  A properly built crack has no hum whatsoever...  Prior to adding a speedball, the only mod I would suggest is installing your output caps on fly leads so that you can easily upgrade to film caps at some point down the road should you so chose.  [Search the thread for Beefy's explanation and photos illustrating this.]  Once the speedball is in, it is difficult to access the terminals to which those leads need to connect.
  
 If you are buying the speedball along with the stock kit, screwing in the nylon standoffs _before _you wire up the a-socket can also help avoid possible damage to the fragile led's on that socket when you do get around to the speedball.


----------



## skeptic

ben_r_ said:


> Has anyone out there tried grounding them?


 
  
 I grounded mine a while back but never actually measured to see whether it eliminated the small spike in start-up or shut-down voltage.  Although I didn't do so for the first year or so with my crack, my practice these days, out of an abundance of caution, is just to power up before plugging in my phones, and to unplug them before powering down.


----------



## Doc B.

Any Crack we have had around here (I dunno maybe 20 or 30 over the years?) has been dead quiet. I would suggest not trying to fix stuff until you know it's broken. The few (not many) people who reported noise may have had bad solder joints, bad braiding, or an excessively noisy environment.


----------



## ben_r_

doc b. said:


> Any Crack we have had around here (I dunno maybe 20 or 30 over the years?) has been dead quiet. I would suggest not trying to fix stuff until you know it's broken. The few (not many) people who reported noise may have had bad solder joints, bad braiding, or an excessively noisy environment.


 

 We arent discussing fixing any noise issues Doc, just dealing with the voltage spike on power up at the output and why on Bottlehead's own forum there is a sticky thread talking about how it should have been added to the manual to ground the tip and ring connectors on the TRS jack and why that wasnt added to the manual. Seems it would just be a safer way to further ensure no ones headphones ever get damaged.


----------



## Doc B.

Re discussion of noise issues, I was addressing Simanick's post.
  
 I think that blown up headphones from a voltage spike are more legend than reality. Is anyone measuring the spike with headphones plugged in? If you consider the value of the output bleeder resistor and do the math you will see that the spike you are measuring with no headphone plugged in would be about 10 times higher than when you have a 300 ohm can plugged in in parallel with the resistor. In other words the impedance of the headphone itself creates a benign startup. We added that unloaded startup voltage measurement to the checkout to help confirm that one hasn't screwed up some part of the build that would leave a high DC voltage on the output after warm up (e.g., a shorted output coupling cap), not to freak anyone out about blowing s**t up. We leave headphones plugged into Cracks when we fire them up all the time.


----------



## Loquah

> Any Crack we have had around here (I dunno maybe 20 or 30 over the years?) has been dead quiet. I would suggest not trying to fix stuff until you know it's broken. The few (not many) people who reported noise may have had bad solder joints, *bad braiding, or an excessively noisy environment*.


 
  
 I might have been one of those!
  
 I did use the a shielded coaxial cable to "solve the problem", but I changed so many things at the same time that I can't be completely confident that the shielded signal path was the solution. In hindsight (and from experience on other kits, etc.) I'd recommend just building it right and ensuring all your solder joints are good. It's quite likely mine was a ground loop issue or similar as a result of it being my first ever build.


----------



## Bimbleton

Righty-O, I won't try to troubleshoot before any trouble.
 Secretly looking forward to varnishing and painting the Crack to look classy (as many of you on here have already done). I imagine the stuff in a can is not very good (miniwax, I think?), so does anyone have any quick recommendations for the exterior coating?


----------



## HolyCheese

aeolus kratos said:


> My opinion is that the best listening level is just around 30-35% of volume ( the knob is at about 9-10 o' clock position )
> 
> 50% of volume to reach preferable listening level is too much for me.


 

 I'm saying it should be around 50%. 9 o clock for me is just too much. It's very loud and makes my ears ring. I think my ears are just very sensitive since I have this with every amp.
 Now I'm at 7:30 ish. Starting position is 7 o clock. 8 o clock is getting louder. 9 o clock is hardest I go but only for short times.
  
  
 And everyone else. Thanks for the info! I'll see what I can do. Now I have three possibilities. I think goldpoint is best but that's just my guts talking.


----------



## Doc B.

The volume knob setting is influenced by the sensitivity of the headphones and the output level of the source component (and of course where you set the pointer on the knob when you attach it..). So the listening level setting can be all over the place for different setups.


----------



## amcananey

As President of The Ugly Crack Guild, I would remind you that pretty isn't the only way to go...


----------



## palmfish

You are so modest!

You arent just the president, you are the founding member and setter of the bar.


----------



## ben_r_

doc b. said:


> Re discussion of noise issues, I was addressing Simanick's post.
> 
> I think that blown up headphones from a voltage spike are more legend than reality. Is anyone measuring the spike with headphones plugged in? If you consider the value of the output bleeder resistor and do the math you will see that the spike you are measuring with no headphone plugged in would be about 10 times higher than when you have a 300 ohm can plugged in in parallel with the resistor. In other words the impedance of the headphone itself creates a benign startup. We added that unloaded startup voltage measurement to the checkout to help confirm that one hasn't screwed up some part of the build that would leave a high DC voltage on the output after warm up (e.g., a shorted output coupling cap), not to freak anyone out about blowing s**t up. We leave headphones plugged into Cracks when we fire them up all the time.


 

 Sorry about that, conversations got mixed up.
  
 So I just verified, a Crack with Speedball and a 270 Ohm load on both channels ends up outputting an up to 2.5v voltage spike, which is indeed much lower than the up to 20v spike that is seen with no load.


----------



## brunk

palmfish said:


> You are so modest!
> 
> You arent just the president, you are the founding member and setter of the bar.


 
 Aww come on now, you know you want to listen to that beast. I know I do!


----------



## grrraymond

Quick question for any UK Crack fiends: Did you receive a shipping confirmation from BH?

I put my order in towards the end of September and looking at the delivery status ("orders through 10/2 shipped"), I guess that technically means mine will have been shipped.

I haven't received confirmation of the same from BH, though, so was just wondering if I have anything to worry about. I only mention because I saw a few people mention shipping confirmation...

Edit: Also, I've only just realised this having scoured the BH site, but will I also be paying UK customs fees on top? Not a big issue, but just not something I'd realised - entirely due to my own over-eagerness/stupidity.

Thanks for any help you guys can give.


----------



## Doc B.

Head fi members are pretty sharp guys, but I doubt they know our shipping log. You can always contact Eileen at queen at bottlehead dot com for an update on your order status.


----------



## captslow

Will be putting my order in shortly! Excited, now time to go shopping for a new soldering iron and multimeter!


----------



## Loquah

Congrats! Enjoy.


----------



## grrraymond

doc b. said:


> Head fi members are pretty sharp guys, but I doubt they know our shipping log. You can always contact Eileen at queen at bottlehead dot com for an update on your order status.




Thanks Doc. Eileen got straight back to me and it's in transit! Very excited.


----------



## mithrandir38

Just finished my crack yesterday and want to post a couple pictures, but I don't have the necessary "permission" to do it?  Help anyone?
  
 Nevermind. Figured it out


----------



## mithrandir38

spent about 15 hours on the build, triple checking each direction.  Had no issues when it was finished.  I'm going to be finishing the cabinet this weekend with stain and laquer.  Sounds awesome with no hum or imbalance issues, and dead silent!


----------



## Loquah

Nice work and nice pics!!


----------



## mithrandir38

loquah said:


> Nice work and nice pics!!


 
 Thanks Bro!  I may tape off the transformer and paint the bell as well. But it's gonna stay pretty much stock.  I love the sound and I'm only gonna tinker with tubes.


----------



## brunk

mithrandir38 said:


> Thanks Bro!  I may tape off the transformer and paint the bell as well. But it's gonna stay pretty much stock.  *I love the sound and I'm only gonna tinker with tubes.*


 
 Hehe, Doc strikes again!


----------



## Doc B.

Do put some kind of protection on the bell end, even if it's just paste wax or regular treament with a wipe of light oil like 3 in 1 or Remoil. It's raw steel that just gets a temporary coating of a sort of waxy oil in manufacturing, and it will eventually rust if left in even a moderately humid environment without any protection. Best bet is to clean it well to remove the existing treatment (naptha or acetone) and then shoot it with your choice of clear coat or paint.


----------



## mithrandir38

doc b. said:


> Do put some kind of protection on the bell end, even if it's just paste wax or regular treament with a wipe of light oil like 3 in 1 or Remoil. It's raw steel that just gets a temporary coating of a sort of waxy oil in manufacturing, and it will eventually rust if left in even a moderately humid environment without any protection. Best bet is to clean it well to remove the existing treatment (naptha or acetone) and then shoot it with your choice of clear coat or paint.


 
 Thanks for the advice, Doc!  And thanks for a great product.  It costs about the same as the Schiit Asgard 2, but I think it is far superior in tone, especially in the midrange.  The best value in hifi, imo.


----------



## mithrandir38

11/02/13 update:
Minwax English Chestnut finish with 3 coats of semi-gloss.
  

The transformer and the bell are painted with rust-oleum flat black and gloss black, respectively.  I still need to work on finishing the gloss black, as it's a little uneven.  But the wood finish came out better than I had hoped; it almost glows.


----------



## sjeffrey

mithrandir38 said:


> Spoiler: Warning: Spoiler!
> 
> 
> 
> ...


 
 I love the look of this.  The black bell looks really good.  I am waiting for my walnut headphone stand to stain the base so I can try to match the color.


----------



## mithrandir38

sjeffrey said:


> I love the look of this.  The black bell looks really good.  I am waiting for my walnut headphone stand to stain the base so I can try to match the color.


 
 Thx, man!  Enjoy that project.  I haven't done any wood working since the eighth grade (I'm now 39), and it was pretty satisfying (because I didn't jack it up!).  Thank god for youtube!


----------



## palmfish

mithrandir38 said:


> The transformer and the bell are painted with rust-oleum flat black and gloss black, respectively.  I still need to work on finishing the gloss black, as it's a little uneven.  But the wood finish came out better than I had hoped; it almost glows.




That looks great! Nice job!


----------



## Mahdi8

So the bell part of the transformer really need to be painted so it doesn't rust? Didn't know that.  now I have to open it up to paint it


----------



## mithrandir38

not necessarily.  you can tape the top of the transformer just below the bell and paint.  you can also put a sealant on it, as doc B described.  Just some kind of coating.


----------



## brunk

mahdi8 said:


> So the bell part of the transformer really need to be painted so it doesn't rust? Didn't know that.
> 
> 
> 
> ...


 
 If I was you, I would just tape it up real good on the outside and spray it. I wouldn't want to risk screwing up a solder joint or something, possibly spending 2x the time of just taping.


----------



## diaBoliQu3

Where I can get complete built version of Crack and offer international shipping?


----------



## Mahdi8

brunk said:


> If I was you, I would just tape it up real good on the outside and spray it. I wouldn't want to risk screwing up a solder joint or something, possibly spending 2x the time of just taping.





mithrandir38 said:


> not necessarily.  you can tape the top of the transformer just below the bell and paint.  you can also put a sealant on it, as doc B described.  Just some kind of coating.




But if it's a matter if rust. Would it not rust from the inside side of the bell?


----------



## brunk

mahdi8 said:


> But if it's a matter if rust. Would it not rust from the inside side of the bell?


 
 I wouldn't stress it too much about the inside of the bell.


----------



## Loquah

mahdi8 said:


> So the bell part of the transformer really need to be painted so it doesn't rust? Didn't know that.
> 
> 
> 
> ...


 
  
 I'm in the same boat, Mahdi8. The Crack was my first ever DIY so I didn't really tinker with it, but am now deciding whether to dismantle and go fully custom!!


----------



## ULTRA-HARMONICS

Thanks Doc for the AMazing Crack+SB... My Senns have never sounded better!


----------



## Mahdi8

brunk said:


> I wouldn't stress it too much about the inside of the bell.


 
 Are you sure about that? I mean I want this to last many years. Or a little rust won't be an issue ie cosmetic only? if yes then I wouldn't worry so much


loquah said:


> I'm in the same boat, Mahdi8. The Crack was my first ever DIY so I didn't really tinker with it, but am now deciding whether to dismantle and go fully custom!!


 
  
 Yeah I wish it was made more clear in the manual that rust may be an issue if you didn't paint properly. I would have done so


----------



## Mahdi8

sorry double post


----------



## JamieMcC

> Originally Posted by *DefQon* /img/forum/go_quote.gif
> 
> I was and am still thinking of carbon fibering the top aluminium plate, but I'm not sure the carbon fiber decal can tolerate a few hours or constant daily use of on and off 40-55'C. Please do let me know if you pull it off on yours.


 
 Regarding the carbon overlay the carbon fibre will be able to handle the heat without any problem but you will need to use the correct resin, it would be best to use a epoxy resin, using the correct resin the heat will actually make the carbon resin matrix stronger.
  
 The bit of carbon in the picture was made up on a piece of flat glass.
  
 The much much quicker, cleaner, safer and cheaper way to get the same effect would be to buy a small length of the carbon fibre effect vinyl decal the self adhesive type they use for wrapping cars there are some stunning colours and graphics available.  It should be less expensive than painting around $5 with free delivery off of fleebay. No half used can of paint no brushes to clean out no sanding between coats etc etc. I am Starting to warm to the idea myself!
  
 I just happen to have a left over bit of carbon that's been hanging around.
 .


----------



## JamieMcC

grrraymond said:


> Quick question for any UK Crack fiends: Did you receive a shipping confirmation from BH?
> 
> I put my order in towards the end of September and looking at the delivery status ("orders through 10/2 shipped"), I guess that technically means mine will have been shipped.
> 
> ...


 
  
 Import duty/tax almost certainly for crack speedball expect around £70-80 with customs clearing fee before they deliver. You should receive a letter with detail shortly after the item has clear customs.
  
 Amplifier has an import duty rate of 3.7% and VAT rate of 20% + Import handling fees by Royal Mail: £8 per parcel liable for customs charges
  
http://www.dutycalculator.com/new-import-duty-and-tax-calculation/
  
 It gets expensive rather quickly


----------



## NightFlight

importing into Canada can be brutal. UPS (brown) is to blame. They are charging around 60-70$ regardless of duty and such. As a process fee. They have been class-actiomed for the practice, but they still persist. Its hare to tell a shipper not to use UPS. IE, I can't be your customer if you insist on using UPS.


----------



## brunk

mahdi8 said:


> Are you sure about that? I mean I want this to last many years. Or a little rust won't be an issue ie cosmetic only? if yes then I wouldn't worry so much


 
 Correct, it's just for cosmetic purposes.


----------



## JamieMcC

Just checked my tracking number my Crack as of October 31 it is clearing UK customs. It might just arrive this week, perhaps fingers crossed and I am still undecided on what to go with finish wise even after the wait!


----------



## mvrk10256

has anyone else tried the crack with HE-400s? I know its not ideal, but strangely I get a weird distortion/buzzing when I hook them up. I have the crack with speedball and it sounds beautiful with my other high impedance phones.


----------



## HolyCheese

I think I have a bad tube.
 When I touch the amp or tap the desk it's on I hear it in the left channel. When I rub my finger across the metal plate it even sounds trough the tube. Tapping the tube is, ofcourse, audible and quitte loud really.
 This is mostly in the left channel.
  
 This isn't that big of a problem. I have another more anoying problem.
 It started with slight crackling every now and then whenever I wasn't listening to music and the amp was on. It happened regardless of volume. Anyway I guessed this might go away with burn in but apparently it's the Wi-Fi's fault. I tested it today and it picks up the signals. Shielding it with some heavy metal 
	

	
	
		
		

		
		
	


	




 makes the crackling/noise go away. I'm talking about the small input tube. When i'm downloading at full speed the noise is actually very load, around 80% of listening level. It happens only at the 2.5gHz band but unfortunately 5gHz is no option.
  
 What's up here?
  
  
 edit:
 Ohhhh and I have another question.. Is it possible to use an PCC189 tube or an 6H23N "Rocket logo" tube with this amp? I have those laying around. I heard they are similar to 6992 tubes and that those are just lower in volume that 12au7 tubes.
 So would they fit? I'd love to tube roll and it temporarily gets rid of the wifi interference.


----------



## lextek

mvrk10256 said:


> has anyone else tried the crack with HE-400s? I know its not ideal, but strangely I get a weird distortion/buzzing when I hook them up. I have the crack with speedball and it sounds beautiful with my other high impedance phones.


 
 I demoed some HE-400s and never had an issue with Crack/Speedball.  Didn't really think much of the sound if a remember correctly.


----------



## ffivaz

HolyCheese, you could use a tube shield. An aluminium tube covering the tubes, it replaces the metal ring covering your tube socket. Something like that: http://www.ebay.com/bhp/vacuum-tube-shield.


----------



## brunk

holycheese said:


> I think I have a bad tube.
> When I touch the amp or tap the desk it's on I hear it in the left channel. When I rub my finger across the metal plate it even sounds trough the tube. Tapping the tube is, ofcourse, audible and quitte loud really.
> This is mostly in the left channel.
> 
> ...


 
 Definitely a bad tube. Do you have the wifi router, or your antenna receiver near the amp? Try moving them away, atleast some shielding had worked for you. What you are experiencing is called RFI, Radio Frequency Interference.


----------



## Loquah

mvrk10256 said:


> has anyone else tried the crack with HE-400s? I know its not ideal, but strangely I get a weird distortion/buzzing when I hook them up. I have the crack with speedball and it sounds beautiful with my other high impedance phones.


 
  
 HE-400s are only 35 ohm headphones so a long way off from pairing well with the Crack's 120 ohm output impedance. Best to stick with a good <4ohm OI amp for those


----------



## palmfish

loquah said:


> HE-400s are only 35 ohm headphones so a long way off from pairing well with the Crack's 120 ohm output impedance. Best to stick with a good <4ohm OI amp for those




The HE-400 is a planar magnetic. Output impedance of the amp is irrelevant.


----------



## brunk

palmfish said:


> The HE-400 is a planar magnetic. *Output impedance of the amp is irrelevant.*


 
 Out of curiosity, why is that?


----------



## Loquah

palmfish said:


> The HE-400 is a planar magnetic. Output impedance of the amp is irrelevant.


 
  
 As I understand it, the planars have no problems with frequency response fluctuations caused by poor impedance matching, but from what I've read the lack of electronic damping in planars means they rely on damping via the amplifier to prevent "flapping". Is this correct?


----------



## palmfish

1. The impedance of planar magnetic drivers is flat so it presents the amp with a constant load across the entire freq band, therefore there are no changes in frequency response due to varying loads.
2. The driver is not a suspended push/pull mass that suffers from rebound and thus requires no dampening.


----------



## brunk

loquah said:


> As I understand it, the planars have no problems with frequency response fluctuations caused by poor impedance matching, but from what I've read the lack of electronic damping in planars means they rely on damping via the amplifier to prevent "flapping". Is this correct?


 
  
 Yes, that's what i understand, that current coming out of an amp plays a big role in starting and stopping the planar, reducing over/under shoot.


palmfish said:


> 1. The impedance of planar magnetic drivers is flat so it presents the amp with a constant load across the entire freq band, therefore there are no changes in frequency response due to varying loads.
> 2. The driver is not a suspended push/pull mass that suffers from rebound and thus requires no dampening.


 
 Ok, i understand this as well, since there is relatively zero impedance fluctuation from the planar, it doesn't need the extra "guidance" so to speak.
  
 Thanks to both of you. Some of this i had either forgotten or had a vague understanding in regards to the planars.


----------



## Mahdi8

I've tried mad dog 3.22 which is an ortho with the crack speedball. Really nice MIDs, high and imaging. Albeit slightly cold. The main issue is the bass it's really loose and blubbery


----------



## Mahdi8

BTW any closed headphone user with the crack here? I use dt770 600ohm. The upgrade path for closed headphone and crack seems to be limited


----------



## Loquah

palmfish said:


> 1. The impedance of planar magnetic drivers is flat so it presents the amp with a constant load across the entire freq band, therefore there are no changes in frequency response due to varying loads.
> 2. The driver is not a suspended push/pull mass that suffers from rebound and thus requires no dampening.


 
  
 Agree with 1. Not sure about 2.
  
 From what I've read, there is no mechanical damping of the driver (like the suspension which causes the push/pull/rebound effect) and therefore can get "loose" if not sufficiently damped electronically (by the amp circuitry). I haven't played with planars yet in order to test this for myself.
  
 Does anyone here have a planar they can try with the Crack and compare to a different, low OI amp as a comparison?


----------



## palmfish

loquah said:


> As I understand it, the planars have no problems with frequency response fluctuations caused by poor impedance matching, but from what I've read the lack of electronic damping in planars means they rely on damping via the amplifier to prevent "flapping". Is this correct?




The term "poor impedance matching" doesnt really describe how or why the freq response changes. To visualize what is happening with the headphone-amplifier relationship, you must understand what is causing the impedance swings in some headphones (resonant frequencies) and how those swings change the way the amplifier drives them.

Electrical damping is a vague term. Damping or dampening is a mechanical force; the act of controlling extraneous driver movement (rebound). That force can be electrical (from the amplifier) or mechanical (from the driver suspension), but the force felt by the driver is the same. Planar magnetic drivers dont "move" like acoustic suspension drivers do, so they dont have a resonant frequency. No resonance, no need for damping.

Maybe an engineer will chime in and correct whatever mistakes I have made.


----------



## Mahdi8

Well the main different with crack and solid state or hybrid amp I've tried for the mad dog (o2 and torpedo parafeed) is the bass is significantly better on the others but I actually prefer crack for the rest of sound quality. Most likely because crack has a better sound stage and smoother sound overall


----------



## Loquah

mahdi8 said:


> Well the main different with crack and solid state or hybrid amp I've tried for the mad dog (o2 and torpedo parafeed) is the bass is significantly better on the others but I actually prefer crack for the rest of sound quality. Most likely because crack has a better sound stage and smoother sound overall


 
  
 Thanks Mahdi. When you say the bass is better do you mean tighter, looser, more quantity, etc.?


----------



## Mahdi8

mahdi8 said:


> I've tried mad dog 3.22 which is an ortho with the crack speedball. Really nice MIDs, high and imaging. Albeit slightly cold. The main issue is the bass it's really loose and blubbery





loquah said:


> Thanks Mahdi. When you say the bass is better do you mean tighter, looser, more quantity, etc.?




You might miss my previous post. The combination with mad dog makes the bass loose and blubbery to the point sounds like low frequency distortion to me. Especially the mid bass. Mad dog sounds much better with other amp. Well unless music you listen has no bass then that combination has pretty good sound.

All depend what you normally listen to I guess


----------



## Loquah

mahdi8 said:


> You might miss my previous post. The combination with mad dog makes the bass loose and blubbery to the point sounds like low frequency distortion to me. Especially the mid bass. Mad dog sounds much better with other amp. Well unless music you listen has no bass then that combination has pretty good sound.
> 
> All depend what you normally listen to I guess


 
  
 Thanks. I had forgotten that post. I think this looseness is the "flapping" I have read about where the amplifier doesn't provide sufficient electronic damping to stop the diaphragm once it's moving, hence the distorted, loose sound.


----------



## Aeolus Kratos

mvrk10256 said:


> has anyone else tried the crack with HE-400s? I know its not ideal, but strangely I get a weird distortion/buzzing when I hook them up. I have the crack with speedball and it sounds beautiful with my other high impedance phones.


 

 I'm in the same boat, I tried a HE-400 with my Crack and actually I couldn't even listen to it longer than 5 minutes because of distortions.


----------



## HolyCheese

ffivaz said:


> HolyCheese, you could use a tube shield. An aluminium tube covering the tubes, it replaces the metal ring covering your tube socket. Something like that: http://www.ebay.com/bhp/vacuum-tube-shield.


 

 Hmm Those are pretty ugly. I like the nice glowing in the dark.
  
  
 And placing doesn't really matter since it happens anywhere on my desk. It's next to my laptop but that's on LAN and the wifi comes from my bed 2 meters away. The router is much further away. I don't even live in a busy place with alot of wifi around..
  
  
 What about the alternative non 12au7 tubes for this amp?


----------



## olegausany

You can use 6SN7s but you will need to get adapter for them


----------



## amcananey

I would say: don't bother.

I do NOT have any problems with noise from my router (or any other source), but I have 4 of those adapters from 3 different manufacturers and all of them induce intolerable noise with 6SN7s. You can avoid the issue by building a separate power supply for the input tube, but all I can say is: it's not worth it. The Crack sounds great with 12AU7s, so why chase other tubes that are highly unlikely to be an improvement?

An easier option would be to try changing your router.


----------



## palmfish

I had my Crack on the top of my cabinet next to my Squeezebox and the interference was bad. I had to move it about 4' away to get rid of it.


----------



## mvrk10256

amcananey said:


> I would say: don't bother.
> 
> I do NOT have any problems with noise from my router (or any other source), but I have 4 of those adapters from 3 different manufacturers and all of them induce intolerable noise with 6SN7s. You can avoid the issue by building a separate power supply for the input tube, but all I can say is: it's not worth it. The Crack sounds great with 12AU7s, so why chase other tubes that are highly unlikely to be an improvement?
> 
> An easier option would be to try changing your router.


 
  
 if you have the speedball its a plug and play affair to change tubes.


----------



## amcananey

In theory, it's a plug and play affair even without the Speedball. As I understand it, the 6SN7 is just a 12AU7 in a different package. It isn't a near-equivalent, it IS equivalent.

In any case, I have the Speedball installed. And I have tried 4 different adapters and probably 15+ different 6SN7s. The noise was intolerable with all of them.

According to Bottlehead, the way to avoid this is by installing a separate 6.3V DC power supply for the input tube. But that is way too much effort, given that the Crack already sounds phenomenal with the 12AU7. Besides, I am done modding my Crack.


----------



## ffivaz

HolyCheese, you could try changing the 12au7 for another 12au7. I don't think the 6SN7 is more RFI tolerant than the 12au7.


----------



## HolyCheese

Well I wasn't talkig about the 6SN7's actually.
 I have some PCC189's and 6H23N rocket logos laying here and hoped they might fit.
  
 It's true that someone from Bottlehead is active here right? Is a faulty tube covered by warranty? Or should I go on ebay and buy another one.
  
 Atleast i'm Lucky it still works as longs as I shield it somehow.


----------



## Doc B.

Some one from Bottlehead is active here. Me. But I don't know what various participants usernames are. The best way to get a new tube is to contact us via email - replacementparts@bottlehead.com, or by phone 206-451-4275. That way you can tell us who you really are and we can be sure we know your address. We really can't do much about our mid 20th century tubes being hammered by RFI generated by 21st century devices that are supposed to be FCC regulated. Tube shields may or may not help much. Distance between pieces of gear is the best and cheapest way to reduce the problem. However if a tube is making noise on it's own - humming or hissing or crackling, we will happily send you a replacement. If it only makes noise when you tap on it, try not tapping on it. That seems to be a reliable solution.
  
 Lots of posts this weekend. Some responses -
  
 Re rust on bell end - Interesting that the unfinished bell end seems to surprise builders, but they readily accept that the wood and chassis panels have no finish. The kit is intended to be finished by the builder.
  
 Re planar headphones - doesn't matter that they are planar, an impedance mismatch is an impedance mismatch and bass from Crack will be flabby with low impedance cans. Use high impedance headphones with the Crack and bass will be nice and tight. We make two other amps that are designed to work with low impedance and planar headphones. Bet you never heard me say any of that before...


----------



## amcananey

doc b. said:


> Re rust on bell end - Interesting that the unfinished bell end seems to surprise builders, but they readily accept that the wood and chassis panels have no finish. The kit is intended to be finished by the builder.



 


Doc,

I'm a big fan of your products, own 4 of them, and regularly recommend them quite loudly here.

But I do find the issue of the bell end frustrating. When I see a couple of unfinished wooden blocks in the package, with instructions on how to glue them together, it is obvious to me that they need to be glued together. And it is also fairly clear that if I want the wood case painted or stained, that I have to do that. Moreover, given the way the case works, I can build the Crack and get it working first, then easily finish the case later.

It was NOT clear to me, however, that the bell end needed to be treated to prevent rust. There is nothing about the bell end that clearly indicates to the lay person that it needs to be finished. It doesn't seem unreasonable that this should be mentioned in the directions (not just mentioning that users CAN paint the bell end -- I mean mentioning that users SHOULD paint the bell end to avoid rust). Especially since (unlike the wood case) it is much harder to do once the Crack is fully assembled (not impossible, just harder, with an increased risk of painting/spraying stuff you don't want painted/sprayed). 

Leaving aesthetic matters up to customers without comment is one thing, but I do think that functional matters should by explicitly discussed. To be clear: I'm not saying that Bottlehead should finish the bell end for me. I'm saying that you should alert customers that they need to finish the bell end themselves in order to avoid rust.

Best regards,
Adam


----------



## Tequilasunriser

I used gun bluing on my end bell. I buffed the corners to give it that "antique" look. Bluing is a form of oxidation that will prevent the formation of rust, so those of you that are looking to treat the metal without painting it look into a bluing kit. They're fairly cheap and the bluing is easy to apply.


----------



## mcandmar

tequilasunriser said:


> I used gun bluing on my end bell. I buffed the corners to give it that "antique" look. Bluing is a form of oxidation that will prevent the formation of rust, so those of you that are looking to treat the metal without painting it look into a bluing kit. They're fairly cheap and the bluing is easy to apply.


 
  
 Are you sure about that?   I have a Birchwood Gun Blue kit on order but i read it wont stop oxidation so its advised to clear lacquer the finish afterwards.  Either way i figured it would be a more interesting finish that plain paint, that said paint is my backup plan incase it all goes horribly wrong.
  
 @amcananey, its mild steel of course its going to oxidize with moisture, they paint cars for that very reason.  It might take months, it might take years, it all depends on your climate and humidity.


----------



## Tequilasunriser

mcandmar said:


> Are you sure about that?   I have a Birchwood Gun Blue kit on order but i read it wont stop oxidation so its advised to clear lacquer the finish afterwards.  Either way i figured it would be a more interesting finish that plain paint, that said paint is my backup plan incase it all goes horribly wrong.
> 
> @amcananey, its mild steel of course its going to oxidize with moisture, they paint cars for that very reason.  It might take months, it might take years, it all depends on your climate and humidity.


 
 Well, any hole or even a microscopic area where bare metal is exposed can cause the formation of rust. Just like a car that has a razor thin scratch in its paint; it is still subject to getting rust. I have an antique shotgun that was factory blued but is now developing a few pitted areas of rust, but that's expected over time if the bluing isn't maintained much like a car's paint. I applied the bluing about 2 years ago, and to this date there's no rust, but if it's not maintained then I would imagine rust could form down the line...
  
 The idea is that rust is less _likely_ to form because one form of oxidation is being substituted with another.


----------



## Doc B.

Bluing looks great, but does not prevent rust. Ask any gun owner. We suggest shooting the bluing with clear coat.
  
 Adam - I will take your suggestion under consideration. Are your bell ends rusting?
  
 It is really easy to paint a bell end that is installed. Simply cut a rectangular hole the size of the bell end in a piece of cardboard. The cardboard should be bigger than the top of the amp so it protects it from overspray. Place the cardboard over the amp with just the bell protruding through and shoot your favorite spray. We have done many bell ends here with this method, in fact we have a carboard mask we keep in a cabinet specifically for the purpose.


----------



## Mahdi8

Can I use a regular spray paint can to do the bell end job?


----------



## audiowize

Yes.
  
 Oil based paint is way, way, way better than the acrylic stuff.


----------



## amcananey

"@amcananey, its mild steel of course its going to oxidize with moisture, they paint cars for that very reason. "

That's great...as long as you know that it is "mild steel". And how exactly am I supposed to know that? I wouldn't know steel from any other metal. I know the chassis is aluminum, and I know aluminum doesn't rust. Beyond that I don't have a clue.


----------



## amcananey

doc b. said:


> Bluing looks great, but does not prevent rust. Ask any gun owner. We suggest shooting the bluing with clear coat.
> 
> Adam - I will take your suggestion under consideration. Are your bell ends rusting?
> 
> It is really easy to paint a bell end that is installed. Simply cut a rectangular hole the size of the bell end in a piece of cardboard. The cardboard should be bigger than the top of the amp so it protects it from overspray. Place the cardboard over the amp with just the bell protruding through and shoot your favorite spray. We have done many bell ends here with this method, in fact we have a carboard mask we keep in a cabinet specifically for the purpose.


Thanks, Doc. I've since become aware of that solution.


----------



## mcandmar

amcananey said:


> "@amcananey, its mild steel of course its going to oxidize with moisture, they paint cars for that very reason. "
> 
> That's great...as long as you know that it is "mild steel". And how exactly am I supposed to know that? I wouldn't know steel from any other metal. I know the chassis is aluminum, and I know aluminum doesn't rust. Beyond that I don't have a clue.


 
  
 Sorry man, didn't mean for that to sound condescending.  What i meant to say is any bare untreated metal is going to oxidize, even aluminium, just some do it faster than others.


----------



## EraserXIV

Other than aesthetics, is there anything functionally bad about the rust? Noticed that mine rusted as well but didn't think much of it


----------



## captslow

eraserxiv said:


> Other than aesthetics, is there anything functionally bad about the rust? Noticed that mine rusted as well but didn't think much of it


 
 If it is only external and not near any electrical connections, then no, although eventually, it will fully rot away, as we all will, given the appropriate amount of time....


----------



## JamieMcC

Unexpected good news on the UK Crack front I have just received notice for duty and custom clearance fees for Crack and Speedball. it was in fact much less than anticipated via the earlier posted calculator which gave £80 in the end it was only £27 must be something to do with it being in the kit form as parts.  Should be delivered tomorrow.


----------



## brunk

jamiemcc said:


> Unexpected good news on the UK Crack front I have just received notice for duty and custom clearance fees for Crack and Speedball. it was in fact much less than anticipated via the earlier posted calculator which gave £80 in the end it was only £27 must be something to do with it being in the kit form as parts. * Should be delivered tomorrow.*


----------



## Doc B.

Many years ago I did a custom amp in which I used one of the "antiquing" kits that created rust. I did the channel frames of the chokes, and the bell end of the power transformer. Used a green flocking on the coils and a green suede texture paint on the chassis panel, and wrapped the fly leads with bare copper tape. IIRC I sprayed a matte clear finish over the rust. Sold rather quickly.


----------



## Doc B.




----------



## brunk

^ Very cool Doc!


----------



## JamieMcC

That's a smashing look, its got that steam punk look going for it, sticking with the antiquing theme Doc's green top reminded me of that lovely green patina bronze gets when its been left out side, it would go really well with the rust and wouldn't look out of place as part of the Time Machine out of a Jules Verne novel.


----------



## Mahdi8

Just got my rca clear top. Even with the standard 6080wa my of my it changes the crack to even better. The bass is crazy tight. This amp is keep improving with every changes


----------



## Loquah

The clear top is such a great tube and the Crack a great amp. Best thing is that they're both really well priced!


----------



## NightFlight

Speaking of RCA clear tops. Is there a better year to seek out?


----------



## brunk

nightflight said:


> Speaking of RCA clear tops. Is there a better year to seek out?


 
 Not that I have personally found a better year, but a NOS matched Mu is a good better bet.


----------



## Loquah

Mu?


----------



## amcananey

Purr?


----------



## FlySweep

mutual transconductance


----------



## brunk

flysweep said:


> mutual transconductance


 
 Yes. Thanks FlySweep.


----------



## amcananey

That only happens when you hold the cat close enough to feel the vibrations.


----------



## Loquah

Ok. Completely confused. I think my brain's melting.


----------



## amcananey

Mu --> mew --> purr --> vibrations --> holding cat close --> transconductance --> you feel the cat Mu-ing --> I'll shut up now. 

It was a long day at work. I was trying to inject some offbeat humor.


----------



## brunk

loquah said:


> Ok. Completely confused. I think my brain's melting.


 
 Lol sorry, i left you guys in the dark.
  
 This is one of the shortest simplest articles explaining it:
  
http://www.tubeaudiostore.com/tubmatdem.html


----------



## amcananey

I got it, I was just going for humor (fail). Didn't mean to confuse...


----------



## brunk

amcananey said:


> I got it, I was just going for humor (fail). Didn't mean to confuse...


 
 Oh I know you were lol. I just wanted to address Loquah 
	

	
	
		
		

		
			




  
 Meow...


----------



## FlySweep

brunk said:


> Meow...


----------



## Loquah

LOL


----------



## Acknown3

Hey guys. I just got my Aune and was considering picking up the Crack with Speedball upgrade. I ordered an Amperex OG for my Aune, so does this mean that if I get the Crack, I should get another Amperex for it? Should I use the same bulb for both or is it better to mix than match?
  
 Thanks!


----------



## amcananey

Doesn't really matter one way or the other.


----------



## brunk

acknown3 said:


> Hey guys. I just got my Aune and was considering picking up the Crack with Speedball upgrade. I ordered an Amperex OG for my Aune, so does this mean that if I get the Crack, I should get another Amperex for it? Should I use the same bulb for both or is it better to mix than match?
> 
> Thanks!


 
 There's really no clear path for you. Only your ears can be your guide, but sticking with the tubes that Doc sends you for a while is a good starting point before you start changing things for the sake of it.


----------



## Nic Rhodes

doesn't the Aune use an E88CC / 6922,  ECC88 / 6DJ8 and not the 12AU7 / ECC82? I haven't got an Aune but a 12AU7 would be an odd choice for that type of circuit. If it is E88CC / 6922,  ECC88 / 6DJ8 I would not use it in your crack.


----------



## JamieMcC

My Crack arrived on Wednesday and today I began my build! Starting with gluing up of the wood enclosure and prepping of the alloy plate.
  
 Very impressed with the build manual. The speedball looks a bit daunting at first for this newbie so hopefully after building the crack I will feel a bit more confident. As I have never done any soldering before I am also going to need to do some practice pieces first before I get started.


----------



## amcananey

If you want a simple project to get some soldering practice before you tackle the Crack, check here: http://www.rock-grotto.co.uk/x-feed.htm

It's very simple, good experience, you can't really break anything, and you'll have something potentially useful when you're finished.


----------



## amcananey

I should add that it only takes about 30 minutes to build, and when complete, you will have all the experience you need to build the Crack.


----------



## Loquah

Also, don't be daunted by the Speedball.
  
 It's definitely worth "cutting your teeth" on the stock Crack build first, but you'll be fine with just a little patience and care. Another benefit with separating the 2 builds (Crack and Speedball) is hearing the difference with and without the SB.
  
 As some others here have wisely advised, you may want to install the plastic spacers for the Speedball during your initial build even if you're not doing the SB straight away.


----------



## Acknown3

I think I'll just buy the base kit now and the speedball later. Like a lot of others, I don't have any soldering experience, but I plan on calling my dad and spending an evening or two working on this with him. Does it matter what type of solder you use? Since I'm sure he doesn't have the highest quality stuff.


----------



## brunk

acknown3 said:


> I think I'll just buy the base kit now and the speedball later. Like a lot of others, I don't have any soldering experience, but I plan on calling my dad and spending an evening or two working on this with him. Does it matter what type of solder you use? Since I'm sure he doesn't have the highest quality stuff.


 
 Standard 60/40 solder is best for beginners. Further, get some with a small diameter so you can work with it very easily.


----------



## amcananey

I prefer 63/37. If you can, try to get a no-clean version. It doesn't matter for purposes of the Crack, but it is useful if you ever build a DIY solid state amp (which you will want to do after this)...

I happen to like Kester 245 solder. From memory, .031" is a good diameter to use.


----------



## JamieMcC

Build update
  
 As I had a piece of carbon fibre left over already and would have needed to buy some paint for the top plate I decided to cut a piece to fit and see how it looked. After first assembling the wooden enclosure which has had its first coat of some Danish oil which I had left over.
  
 I still need to cut the holes out but gives a feel for how it will look. (I later glued the carbon fibre sheet on to the alloy top plate in case anyone is wondering).
  
                 
  
 I did plan to start the build the day before during my lunch break. However the marina next door decided to start its November the 5th bonfire (Its Guy Fawkes Day in the UK we celebrate with bonfires and fireworks) at midday so decided to watch that instead they spent about £3 million on the bonfire! The radar mast I help build a few years back can be seen well alight.
  
  
  .                  
  
 video from the local news.
  

  
 The boat later sank at her berth around midnight.
  
http://www.iwcp.co.uk/news/news/firefighters-called-to-marina-51580.aspx
  
http://www.ancasta.com/boats-for-sale/nordhavn-nordhavn-76-28373/


----------



## mithrandir38

just wanted to give a tip on painting the transformer bell. I sanded the bell, dusted and washed it, sanded it with 420 grit paper, but still got some texturing or bubbling when the gloss paint was applied.
  
 After removing all the paint with paint remover (mineral spirits) I applied the paint again (rustoleum universal gloss black), perfectly smooth and self leveling.
  
 Make sure you use a chemical cleaner on the bell before applying the paint.  It will go so much easier!


----------



## JamieMcC

Thanks for the tip.
  
 On the subject of the bell housing can anyone recall how hot it gets?


----------



## mithrandir38

I'd say no hotter than 150 degrees.  its hot to the touch, but won't ruin the paint.  I know rustoleum and krylon are rated at around 200 degrees.


----------



## clowkoy

About 125-130F measured with an ir thermometer. It's designed to run hot.


----------



## JamieMcC

That's excellent just what I was after thank you.


----------



## bigfatpaulie

I just finished building my new Crack earlier today. I have the SpeedBall still in the back. I figure I should leave if for another weekend!
  





  
 On my desk next to my "to file" pile...  I guess it's getting out of control, eh?
  
  




  
  
 My build...
  
  





 
  
 And in the dark.
  
  
  
 The first two hours with the amp were a little disappointing.  It sounded harsh.  It's warmed up...  A LOT.  It's really a lovely sounding amp.
  
 Cheers!


----------



## brunk

^ Textbook perfection. Excellent job!


----------



## bigfatpaulie

Thanks.  It took about 3 hours start to finish and I took my time.  And I had no issues - who knew!


----------



## brunk

bigfatpaulie said:


> Thanks.  It took about 3 hours start to finish and I took my time.  And I had no issues - who knew!


 
 That's pretty darn fast if it was your first ever build! I had a hell of a time doing mine, had the 5W resistors letting out the magic smoke until I figured out it was a bad 12BH7, but I started out the gate modded lmao.


----------



## bigfatpaulie

I suppose it's my second build.  I built a Headbanger in 2001 for my ER4s.
  
 I was lucky - no bad parts!


----------



## Loquah

Great job, bigfatpaulie. Looks great! Glad the burn-in was successful in "cleaning out" the tubes.


----------



## calipilot227

bigfatpaulie said:


> Thanks.  It took about 3 hours start to finish and I took my time.  And I had no issues - who knew!


 
  
 That's fast, considering it also looks clean! Quite the accomplishment. I think I took about eight hours building mine, but I was working very carefully (perhaps unnecessarily so), making sure the wiring was clean and every solder joint was absolutely perfect. I should probably go get checked for OCD...


----------



## brunk

calipilot227 said:


> That's fast, considering it also looks clean! Quite the accomplishment. I think I took about eight hours building mine, but I was working very carefully (perhaps unnecessarily so), making sure the wiring was clean and every solder joint was absolutely perfect. I should probably go get checked for OCD...


 
 If you engage in an endless loop of checking to make sure you have everything turned off in the house before you leave, then yes by all means get checked out


----------



## Mahdi8

bigfatpaulie said:


> Thanks.  It took about 3 hours start to finish and I took my time.  And I had no issues - who knew!




My hats off to you sir. That is really fast. I did mine around 8 hours with a help of a friend


----------



## calipilot227

brunk said:


> If you engage in an endless loop of checking to make sure you have everything turned off in the house before you leave, then yes by all means get checked out


 
  
 Fortunately, it only extends to audio-related activities (wiring, cartridge alignment, record cleaning, etc).


----------



## brunk

calipilot227 said:


> Fortunately, it only extends to audio-related activities (wiring, cartridge alignment, record cleaning, etc).


 
 You're fine my friend, we all strive to do the best we can in our hobbies!


----------



## JamieMcC

Super neat job, bigfatpaulie. I can only wish mine will turn out so nice.


----------



## JamieMcC

While I am building my Bottlehead Crack a new avatar in tribute to its creator, Doc.


----------



## bigfatpaulie

Thanks Mahdi8 and JamieMcC!  It was a blast to build.  
  
 Just a warning Jamie, there are a few things that the manual doesn't tell you that threw me off.
  
 On page 11, where you install the lager octal socket, you can put a lock washer between the main plate and the socket mounting bracket.  It's to balance the height with the terminal strip on the opposite screw.
  
 And (and this one really needs to be fixed) on page 19 the manual has a revision in red telling you to instead of wiring  and soldering terminal 4 to terminal 22L, wire it to 14U.  DON'T solder it on terminal 14U.  I assumed I should and it was a real pain to desolder it later.
  
 Finally, on the tool list they don't mention a drill, but you need a drill.  Well, you don't "need" a drill, but it's more important than helping hands and they mention those, and a drill is specifically talking about.  So, you need a drill.  I had everything preped for the build and I got to page 18 and had to stop everything to go hunt one down.  
  
 A last little thing I found was that they weren't clear enough about what position is 'U' and which is 'L' (and maybe that's just me, but I had to look ahead in the manual to see what they meant).  'U' (or upper) is the spot furthest from the main plate and the 'L' (or lower) is the spot closest to the main plate.  I suppose it is fairly obvious but manual just says describes it as upper or lower holes.  It doesn't clarify if those are relative to the amp in 'service mode' or in 'regular' mode (ie, with the plate flipped, or in it's normal position).
  
 Any-hoo, I had a great time building it.  I'm a little sad it didn't take longer as I really enjoyed it.  I'm glad I saved the Speedball for another day.
  
 All the best!
  
 -Paul


----------



## JamieMcC

Paul thanks, I started reading  from the start of this thread the other day and shortly after reading your post also came across a few more to do with that 14U area. Drills I have plenty of what I didn't have was a soldering iron so after a visit to the local electrical outlet today I now have a solder station and will have a practice at soldering tomorrow. I Also noticed they had a large selection of led lights which got me thinking about perhaps fitting some kind of down lighting or a pilot light after I have it up and running.
  
 I am enjoying the build so far thinking through the process and exploring ideas for feet, knobs, finish etc its not often I build something for myself.
  
 Making progress covering the bell end of the power transformer with a cosmetic layer of carbon fiber.
  

  
 Add vacuum and heat
  

  
 A little sanding and after flooding on some clear


----------



## Loquah

jamiemcc said:


>


 
  
 Wow. Seriously jealous!!!
  
 I'd love to do this on my Mainline build that's coming up to go with a blue anodised chassis plate. Do you need special gear?


----------



## trentrosa

jamiemcc said:


> Paul thanks, I started reading  from the start of this thread the other day and shortly after reading your post also came across a few more to do with that 14U area. Drills I have plenty of what I didn't have was a soldering iron so after a visit to the local electrical outlet today I picked up a solder station and will have a practice soldering tomorrow. I Also noticed they had a large selection of led lights which got me thinking about perhaps fitting some kind of down lighting or a pilot light after I have it up and running.
> 
> I am enjoying thinking through the process and exploring ideas for feet, knobs, finish etc its not often I build something for myself.
> 
> ...


 
 Wow, that looks really good. Good idea!


----------



## JamieMcC

loquah said:


> Wow. Seriously jealous!!!
> 
> I'd love to do this on my Mainline build that's coming up to go with a blue anodised chassis plate. Do you need special gear?


 
  
 The answer is both yes and no
  
 Yes, if making structural parts having the right kit is essential.
  
 &
  
 No, for small cosmetic parts you could try it with a food saver. Both ways will need sanding and clearing. Vinyl wrap is much easier and quicker.


----------



## mvrk10256

Currently listening to my DT990/600s on the crack. 
  
 so good.
  
 EDIT: GIFs dont work?


----------



## brunk

mvrk10256 said:


> Currently listening to my DT990/600s on the crack.
> 
> so good.
> 
> EDIT: GIFs dont work?


----------



## mvrk10256

brunk said:


>


 
  
 How? I put the link in as a pic and it didnt work.


----------



## brunk

mvrk10256 said:


> How? I put the link in as a pic and it didnt work.


 
 send me the link, and I can tell you what happened.


----------



## brunk

brunk said:


> send me the link, and I can tell you what happened.


 

  
 edit: it works, just make sure you include the entire link under "use url"


----------



## bigfatpaulie

jamiemcc said:


> Paul thanks, I started reading  from the start of this thread the other day and shortly after reading your post also came across a few more to do with that 14U area. Drills I have plenty of what I didn't have was a soldering iron so after a visit to the local electrical outlet today I now have a solder station and will have a practice at soldering tomorrow. I Also noticed they had a large selection of led lights which got me thinking about perhaps fitting some kind of down lighting or a pilot light after I have it up and running.
> 
> I am enjoying the build so far thinking through the process and exploring ideas for feet, knobs, finish etc its not often I build something for myself.
> 
> ...


 
  
 That, Sir, is friggin' amazing!  
  
 What is the plan for the wood base?  If it's 10% as cool as the bell, we are all in for a treat!


----------



## mvrk10256




----------



## JamieMcC

bigfatpaulie said:


>


 
  
 Hi Paul, plans for the wood base well err perhaps not what you or I was expecting, I even surprised myself to be honest. Considering I am lucky enough to have a small boatbuilding shop with a fair bit of woodworking machinery and timber in the racks! But after consideration of several ideas of what might be done the decision (for now) was not to mess to much with the standard Alder case with a clear Norwegian wood oil finish. It has a classic & clean look to it which I like and hopefully should go well with the contrasting black carbon top.
  
 By the way I am going to need a awful lot more practice with a soldering iron before I allow myself anywhere near the Crack!


----------



## grrraymond

Well, I'm absolutely delighted with my Crack.
  
 It arrived a couple of weeks ago to the UK and after a fairly tricky build (no experience, bit of a fat-handed oaf, impatient, tired - classic combo) and some very patient help from Doc and PB over on the forum, my HD650s are absolutely singing! I've been listening to a bit of Aja and Random Access Memories and the drums and bass are - pardon my French - ******* astonishing. Classical (which I never thought was a particular forte of the HD650s) has been making me well up, the way the strings swell and fade..._shudder._ Best of all, though, and quite surprisingly, is electronic music. I've listened to Daft Punk's Homework more times over the last 15 years than I've made pasta and Thomas Bangalter's description of 'orgasmic analogue noise' has never seemed so true. I've never heard or felt so much physicality or 3D movement to those squelching loops, nor so much precision and punch to the 909s. I think I'm starting to understand the tube fetish. The only downside is that I have to come to work and wait another nine hours until I can plug myself back in. Fortunately, the missus is out all night so I can queue up a bourbon and get deaf.


----------



## Loquah

grrraymond said:


> Well, I'm absolutely delighted with my Crack.
> 
> It arrived a couple of weeks ago to the UK and after a fairly tricky build (no experience, bit of a fat-handed oaf, impatient, tired - classic combo) and some very patient help from Doc and PB over on the forum, my HD650s are absolutely singing! I've been listening to a bit of Aja and Random Access Memories and the drums and bass are - pardon my French - ******* astonishing. Classical (which I never thought was a particular forte of the HD650s) has been making me well up, the way the strings swell and fade..._shudder._ Best of all, though, and quite surprisingly, is electronic music. I've listened to Daft Punk's Homework more times over the last 15 years than I've made pasta and Thomas Bangalter's description of 'orgasmic analogue noise' has never seemed so true. I've never heard or felt so much physicality or 3D movement to those squelching loops, nor so much precision and punch to the 909s. I think I'm starting to understand the tube fetish. The only downside is that I have to come to work and wait another nine hours until I can plug myself back in. Fortunately, the missus is out all night so I can queue up a bourbon and get deaf.


 
  
 Sounds like a great night ahead!!
  
 Congrats on the new build and all the pleasure that awaits.
  
 Speaking of great sounding stuff, if anyone wants a treat and likes beautifully sculpted indie rock music (or just a great album of great music), check out Inuit by Ramona Falls - I'm listening to it now on the Crack with Beyer T1s - flat-out awesome!!


----------



## grrraymond

Many thanks, and that's a good tip, too. Cracking record.
  
 On a separate note: I'm using the Fiio E7 (OG edition) as a DAC with my Crack & HD650s. Now, given that I'm predisposed to emptying my wallet out into someone else's pockets each payday, is a better DAC something that will make a significant difference in this chain? In my mind, it's the least important element but that's just my conscience talking so we can discount it.
  
 Would an Uberfrost, say, take things to a higher gear or are we just talking go faster stripes?


----------



## UmustBKidn

grrraymond said:


> Many thanks, and that's a good tip, too. Cracking record.
> 
> On a separate note: I'm using the Fiio E7 (OG edition) as a DAC with my Crack & HD650s. Now, given that I'm predisposed to emptying my wallet out into someone else's pockets each payday, is a better DAC something that will make a significant difference in this chain? In my mind, it's the least important element but that's just my conscience talking so we can discount it.
> 
> Would an Uberfrost, say, take things to a higher gear or are we just talking go faster stripes?


 
  
 Yes and yes. With a bit of a caveat: if you're an Old Guy (tm) like me, you might think carefully on whether or not you could hear the difference between, say, a Schiit Modi and a Schiit Bifrost. The cost difference alone is enough to make me thing twice.
  
 But honestly, I avoid anything made by Fiio. My only experience with anything made by that company was negative. I'll never buy their stuff again.
  
 I do own a Schiit Modi, and it is an awesome DAC. How much better is it, over a Fiio E7? I can't say. And I'm not going to buy a Fiio to find out.
  
 Those who have both Schiit Modi and Bifrost, seem to say that the Bifrost Uber is a noticeable improvement over the Modi. The rest of your gear is definitely enough to hear the difference. So if you've got $520 clams to drop on the Bifrost, do it. If not, personally, I would sell the E7 and buy a Modi.
  
 (oh and PS: hello thread. I've been lurking for a while. The Crack is on the top of my list for my next amp.)


----------



## Loquah

grrraymond said:


> Many thanks, and that's a good tip, too. Cracking record.
> 
> On a separate note: I'm using the Fiio E7 (OG edition) as a DAC with my Crack & HD650s. Now, given that I'm predisposed to emptying my wallet out into someone else's pockets each payday, is a better DAC something that will make a significant difference in this chain? In my mind, it's the least important element but that's just my conscience talking so we can discount it.
> 
> Would an Uberfrost, say, take things to a higher gear or are we just talking go faster stripes?


 
  
 Not to discredit the last poster (we all perceive things differently), my experience is that the DAC ABSOLUTELY will make a difference.
  
 The E7 is a nice unit, but it's an entry-level device.
  
 The step from a decent DAC (like the E7) won't be massive like the step from a PC headphone jack to a dedicated DAC, but it is noticeable if the other parts of the chain are good (and Crack + HD650 = good 
	

	
	
		
		

		
			





).
  
 My first step was an Audio-gd DAC which has been brilliant and outperformed everything lower-level DAC I tried (AudioQuest DragonFly, Soundblaster X-Fi, AK100, etc.) What it did for my sound was provide a larger stage and better clarity and resolution. It wasn't a night and day leap like going from onboard to external DAC, but it was definitely noticeable and obvious.
  
 The step up from the Audio-gd to the Matrix X-Sabre was also obvious and is showing it's potential as I continue to upgrade the amps I use with it. (The Bottlehead S.E.X. is currently blowing my mind having just finished installing the C4S upgrade)


----------



## mullardpassion

AudioQuest DragonFly is an excellent DAC IMO..much better than the Fiio dacs.
 On another note, what power tubes ae you using?? Anyone has had a listen with the 6080wb by Bendix?


----------



## gikigill

Try the Light Harmonic Geek Out or if you could wait, the Geek Pulse.


----------



## Loquah

mullardpassion said:


> AudioQuest DragonFly is an excellent DAC IMO..much better than the Fiio dacs.
> On another note, what power tubes ae you using?? Anyone has had a listen with the 6080wb by Bendix?


 
  
 The Bendix 6080WBs are well regarded in general, but I believe there might be a number of different versions with different plates inside the tube. I'm currently using the GEC curved brown base 6AS7G, but also really like my Mullard 6080WA and GE 6AS7
  
 The DragonFly is very good, but has a slightly compressed soundstage compared to some other DACs I've tried. For it's size and crazy simplicity though it's very hard to beat.


----------



## mullardpassion

Yes, does the different Bendix versions sound the same? I'm curious to try one out, though I'm not paying +$60 for each. Few years back they were max $40...
 I have used a couple of 6AS7Gs before, and currently using the TS 5998...GECs are waay too much for me to afford


----------



## olegausany

Cambridge Audio DacMagic Plus sounds better for me than Bifrost Uber (I used Bifrost for couple of months) with S.E.X. driving HD800 and it's now on sale for just $499 till end of this year


----------



## JamieMcC

re GEC They are often listed in Europe as A1834 or CV2523 rather than 6AS7Gs.
  
 I managed to sniped this pair 
	

	
	
		
		

		
		
	


	




used but tested as strong, straight brown bases one marked GEC one Osram  for $110 delivered.


----------



## JamieMcC

grrraymond said:


> Well, I'm absolutely delighted with my Crack.
> 
> It arrived a couple of weeks ago to the UK and after a fairly tricky build (no experience, bit of a fat-handed oaf, impatient, tired - classic combo) and some very patient help from Doc and PB over on the forum, my HD650s are absolutely singing! I've been listening to a bit of Aja and Random Access Memories and the drums and bass are - pardon my French - ******* astonishing. Classical (which I never thought was a particular forte of the HD650s) has been making me well up, the way the strings swell and fade..._shudder._ Best of all, though, and quite surprisingly, is electronic music. I've listened to Daft Punk's Homework more times over the last 15 years than I've made pasta and Thomas Bangalter's description of 'orgasmic analogue noise' has never seemed so true. I've never heard or felt so much physicality or 3D movement to those squelching loops, nor so much precision and punch to the 909s. I think I'm starting to understand the tube fetish. The only downside is that I have to come to work and wait another nine hours until I can plug myself back in. Fortunately, the missus is out all night so I can queue up a bourbon and get deaf.


 
  
 Orgasmic analogue noise! I am looking forward to having a taste of that myself but I ll have mine with a scotch.




 It sounds like a great match.


----------



## grrraymond

I switched to Scotch myself. Nothing quite like Glenfarclas to go with a bit of Bill Evans.


----------



## Doc B.

I thought Bill Evans went with heroin.


----------



## brunk

doc b. said:


> I thought Bill Evans went with heroin.


----------



## Loquah

doc b. said:


> I thought Bill Evans went with heroin.


 
  
 It always comes back there somehow, doesn't it Doc?


----------



## UmustBKidn

loquah said:


> Not to discredit the last poster (we all perceive things differently), my experience is that the DAC ABSOLUTELY will make a difference.
> 
> The E7 is a nice unit, but it's an entry-level device.
> 
> ...


 
  
 I'm sorry, but could you please point out where I said that a DAC will not make a difference?
  
 Not what I said at all. Please don't put words in my mouth. I get enough of that crap from my ex wife.


----------



## Loquah

Fair point. I didn't intend to put words in your mouth and was going more on the theme of the conversation rather than what you specifically said. I was also picking up on olegausany's comments.

No offense or words in mouth intended.


----------



## Mahdi8

Just my 0.02 fiio e7 are on the same level as ibasso d zero DAC wise. Compared to schiit modi the difference are huge they are in totally different level. Fiio e7 is a decent DAC amp combo but it DAC side is just an entry level DAC. A muse DAC from eBay for $30 has a similar performance with fiio e7 on the DAC front.

I can't say with for other but for me yes for sure crack will sound better if fed a DAC better than e7. Modi is $30 more expensive than e7 so for the price it's well worth the upgrade


----------



## JamieMcC

I was sat gazing fondly at my newly fitted out top plate and then started wondering, I'm not sure if this will be ok but what do you guys think about mounting the 12au7 socket from underneath rather than from the top it gets that retaining ring out of sight and the socket slightly lower giving a flusher look. Can anyone think of any issues with doing this?
  
. 
  
 Its still firmly secured and the tube fits in and out without any problems.
  
 .


----------



## brunk

I did mine underneath with zero issues


----------



## Mahdi8

same here that's how I mount the tube and got no problem


----------



## Loquah

That's a great thought. It's how the sockets are mounted on the S.E.X. too (although those sockets use a rubber damper of sorts between the chassis plate and socket body).


----------



## JamieMcC

Super, thanks for the feed back guys that's just what I was hoping to hear.


----------



## brunk

loquah said:


> That's a great thought. It's how the sockets are mounted on the S.E.X. too (although those sockets use a rubber damper of sorts between the chassis plate and socket body).


 
 Yeah, my secret sauce for that was that I used a small amount of Blue Tack to dampen the tube socket from the chassis. I really put alot of attention to detail in my build so it can perform at its finest


----------



## calipilot227

DAMMIT! I wish I'd thought of that!!! 
	

	
	
		
		

		
			




  
 /rage.
  
 That's turning out to be the best-looking Crack build I've seen to date.


----------



## brunk

calipilot227 said:


> That's turning out to be the best-looking Crack build I've seen to date.


 
 I agree, truly a fine Head-Fi jewel.


----------



## ben_r_

jamiemcc said:


> I was sat gazing fondly at my newly fitted out top plate and then started wondering, I'm not sure if this will be ok but what do you guys think about mounting the 12au7 socket from underneath rather than from the top it gets that retaining ring out of sight and the socket slightly lower giving a flusher look. Can anyone think of any issues with doing this?
> 
> .
> 
> ...


 
  
  
  
 You know what would have been even better? Some better quality and darker colored Belton tube sockets. LINK and LINK
  

  
 And of course painting that wooden base black with lots of gloss varnish.


----------



## brunk

I had actually bought some of those exact Belton sockets, but decided against using them. I would've had to drill out the top plate, and even then they would stick out pretty far out the top.


----------



## JamieMcC

ben_r_ said:


> You know what would have been even better? Some better quality and darker colored Belton tube sockets. LINK and LINK
> 
> 
> And of course painting that wooden base black with lots of gloss varnish.


 
  
 Thanks for the socket links, perhaps next time.
  
 Yes the white sockets would have been nice black the power tube covers its socket completely with the 12au7 it does show a little around the edge. A bit of masking tape a few toothpicks and some of the wife's black nail varnish will take care of the white tube socket surrounds later on.
  
 Black was considered as well as a carbon covered enclosure but I was worried a high gloss piano black or a full carbon finish would change the character to much it would lose those instantly recognisable Bottlehead good looks that set the brand apart from all those other off the shelf black boxed bits of hifi and also I really didn't want yet another black box.
  
 That's the great thing with the Crack you can more or less do what you like in the looks department.  That steam punk rusty looking pic that the Doc posted I think is awesome.


----------



## Mahdi8

jamiemcc said:


> re GEC They are often listed in Europe as A1834 or CV2523 rather than 6AS7Gs.
> 
> I managed to sniped this pair :evil: used but tested as strong, straight brown bases one marked GEC one Osram  for $110 delivered.




Nice purchase where did you get it from?


----------



## JamieMcC

mahdi8 said:


> Nice purchase where did you get it from?


 
  
  http://www.ebay.co.uk/usr/dos107


----------



## m17xr2b

I'm in the process of selling the Crack and the deal is almost done. Now I wanted to make a video to show that the crack is working so I just plugged a VModa M100 just to show that it works. I was not expecting the sound to be any good since the m100 are 32ohm. I was stunned on how good the sound is, treble mids bass it's all there. Bass goes very deep and has good impact. What gives? I know that the crack only works with headphones over 150ohm and it sounds better than my sherwood receiver . If the LCD-X arrives and I still have the Crack I will be sure the give it a try. 
 My crack has speedball and Mundorf M-caps as output, everything else is standard.


----------



## mullardpassion

jamiemcc said:


> re GEC They are often listed in Europe as A1834 or CV2523 rather than 6AS7Gs.
> 
> I managed to sniped this pair
> 
> ...


 
  
  
 Damn good find. For $110, it seems to be a good deal...Nowadays even ts5998s are easily +$100


----------



## JamieMcC

RE Tung sol 5998s l found TC tubes to be very helpful and great to deal with I brought the last few5998's they had in which they described as tested and as new. They where in fact NOS but they don't like to use that term for some reason. They arrived complete with test results and very well packaged. They even gave me a deal on shipping for free which saved me $45 as a deal on buying the last few of their stock at the time.
  
 I just checked they have a 4 more in now in at $72.75 each
  
 "This tube tests as new with balanced sections and very low noise. It was tested at typical operating voltages on a laboratory grade Amplitrex AT1000. This testing process also includes screening for gas, heater-cathode leakage, and shorts. This tube has also been screened for noise and excessive microphonics in our OTL headphone amp"
  
http://tctubes.com/Tung-Sol-5998-tube.aspx


----------



## audiowize

There is nothing wrong with mounting the 9 pin socket from the bottom side of the chassis.  If anything, it can be a little awkward when getting the nuts to sit against the retainer ring. 
  
 Belton sockets are nice (when they are available), though I don't get too excited thinking about a plastic socket sitting under a hot 6080.


----------



## diaBoliQu3

Guys, before I decide to get Crack or not I want to ask few questions.
 - What is the sound for HD600+ Crack? Warm, neutral, bright? I read in review that Crack is neutral and fast. After spending times with warm amp and thick sound amp, I love warm, and fast sound. I afraid that the highs will be ear piercing in neutral amp, or perhaps Crack get them in control?
 - Should I get the speedball or not for HD600? How much sound improvement from basic kit to speeball?
 - What DAC recommended with crack and HD600, price wise about $300 and below. The cheaper the better.
  
 Currently my alternative is LF 336C due to:
 - Warm sound. But the downside is this amp more relax compared to Crack and I listened to heavy metal etc too.
 - Easier to obtained and less hassle.
  
  
 I'm open to other solid state amp for HD600 too within the same prize. Currently my DAC is Aune T1, upgrade in consideration. All my consideration done without listening to the mention amp. So, forgive me for my silly question. I just want to avoid too much upgradetitis.


----------



## mullardpassion

diaboliqu3 said:


> Guys, before I decide to get Crack or not I want to ask few questions.
> - What is the sound for HD600+ Crack? Warm, neutral, bright? I read in review that Crack is neutral and fast. After spending times with warm amp and thick sound amp, I love warm, and fast sound. I afraid that the highs will be ear piercing in neutral amp, or perhaps Crack get them in control?
> - Should I get the speedball or not for HD600? How much sound improvement from basic kit to speeball?
> - What DAC recommended with crack and HD600, price wise about $300 and below. The cheaper the better.
> ...


 
  
 The Crack is warm and not at all harsh. Not with the stock tubes atleast. Tube rolling can make some difference to the sound ( e.g. the RCA 12au7 cleartops were too bright for me. The Mullards are my favourite 12au7 tubes ). For warm and fast sound sound the stock 6080 tube is perfect and dead quiet.


----------



## audiowize

I haven't found the HD-600's to be harsh up top, I wouldn't worry about that.  I would certainly get the Speedball - you get reduced distortion without the negatives generally implemented to obtain this result (primarily feedback).


----------



## diaBoliQu3

mullardpassion said:


> The Crack is warm and not at all harsh. Not with the stock tubes atleast. Tube rolling can make some difference to the sound ( e.g. the RCA 12au7 cleartops were too bright for me. The Mullards are my favourite 12au7 tubes ). For warm and fast sound sound the stock 6080 tube is perfect and dead quiet.


 

 So, even with stock tube, Crack doesn't sound thin and not so harsh, but still energetic, should be good enough. Is that what you meant?


----------



## mullardpassion

diaboliqu3 said:


> So, even with stock tube, Crack doesn't sound thin and not so harsh, but still energetic, should be good enough. Is that what you meant?


 
  
 Exactly. If you want a warmer and more relaxed sound you can still get some cheap RCA 6AS7G ( around $20). It is musical and looks cool too. Gray or black plates, they both sounded the same to me. If you are on a tight budget, you can always get the Speedball later


----------



## diaBoliQu3

mullardpassion said:


> Exactly. If you want a warmer and more relaxed sound you can still get some cheap RCA 6AS7G ( around $20). It is musical and looks cool too. Gray or black plates, they both sounded the same to me. If you are on a tight budget, you can always get the Speedball later


 
 I think I can squeeze some juice for speedball along the base kit. But is it really gonna improve the sound for HD600 when compared to stock kit? I don't have plan to get another headphone after this.


----------



## mullardpassion

diaboliqu3 said:


> I think I can squeeze some juice for speedball along the base kit. But is it really gonna improve the sound for HD600 when compared to stock kit? I don't have plan to get another headphone after this.


 

 It is a definite improvement, though I think you'd appreciate a Speedballed Crack even more after you get used to the stock Crack.


----------



## audiowize

The Crack ships with old stock "lottery" tubes.  There is no stock tube complement.


----------



## diaBoliQu3

audiowize said:


> The Crack ships with old stock "lottery" tubes.  There is no stock tube complement.


 
 So, random tube for different people?


----------



## Loquah

diaboliqu3 said:


> So, random tube for different people?


 
  
 Yes, but they're all 6080 variants as far as I know. (Somebody correct me if the lottery also includes basic 6AS7s, etc.)
  
 In terms of DAC, I would stick with the Aune T1. I know that DAC quite well and I don't think you'll get anything significantly better for <$300. Alternatives, yes, but nothing clearly better.
  
 Agree with others that the Crack is warm, but tight and fast - not bright at all unless you choose a bright tube like the Cleartop, but even then it's still a warm amp in the scheme of things. If you like heavy metal, etc. and need speed, the Speedball is a really good idea because it tightens everything up, particularly in the bass, but doesn't add brightness, just cleaner, tighter sound.


----------



## diaBoliQu3

Guys, paint the bell only, not the power transformer right? And bell referring to the transformer "cover"/ "caps"? Can the bell paint after the assemble, or before?


----------



## Doc B.

You can paint both the bell end and the transformer lam stack. Paint them before. You can do it either way, but it's easier to simply paint them before installation than masking them off to paint them after you have installed them. Just give the paint some time to harden before you get too manly on them with the hand tools.


----------



## diaBoliQu3

Doc, will the transformer get rusty? Any paint should be safe right?


----------



## Doc B.

The transformer itself is impregnated with varnish and won't rust. The bell end can get rusty in humid environments if not coated with something, be it an occasional coat of paste wax or a spray of clear coat or paint. Be sure to clean the bell end well to remove the oily coating it comes with before you try painting it. Oil base paint will usually go on easier than a water base paint.


----------



## bigfatpaulie

I have a (probably stupid) question.
  
 I am building the Speedball for my Crack and I am on page 17 of the manual where it says to:
  
 ( ) Install an MJE350 in the Q2 position as shown, with the
 metalic face of the transistor facing the center of the PC
 board.
  
 My transistors like this:
  
  

  
 No sliver side...  I assume the unmarked side would the 'silver' side?
  
 Thank you kindly!


----------



## Doc B.

http://www.bottlehead.com/smf/index.php/topic,1288.0.html


----------



## bigfatpaulie

Thanks, Doc!


----------



## bigfatpaulie

All done!  Phew.  The Speedball is definitely a step up in difficulty to build vs the Crack itself, but a still very enjoyable build.  I did not have wire cutters that went down small enough, so that was a bit of a challenge!
  
 I also received my missing badge today (Doc, please be sure to thank Eileen again for me!).
  
 I just fired up the amp so, as of this second, I would be hard pressed to comment on the sound difference, but my initial impression is that it has made everything crisper and a little bit more open or airy sounding: welcome changes.
  
 Thank you again Bottlehead and the Team for a great amp!


----------



## skeptic

Congrats Paulie! Bass should be a bit tighter as well. happy listening!


----------



## bigfatpaulie

Thanks Skeptic!
  
 I suppose the next step is...  Tube rolling...  Uh-oh!


----------



## diaBoliQu3

doc b. said:


> The transformer itself is impregnated with varnish and won't rust. The bell end can get rusty in humid environments if not coated with something, be it an occasional coat of paste wax or a spray of clear coat or paint. Be sure to clean the bell end well to remove the oily coating it comes with before you try painting it. Oil base paint will usually go on easier than a water base paint.


 

 Thanks doc... I guess I just will paint the bell... Or paint the bell with clear coat if I want to maintain the originalist look.


----------



## JamieMcC

Well done Paulie 
	

	
	
		
		

		
		
	


	




 enjoy!


----------



## Loquah

jamiemcc said:


> Well done Paulie
> 
> 
> 
> ...


 
 +1


----------



## bigfatpaulie

Thanks folks!
  
 Jamie, how is your purdy build going?


----------



## JamieMcC

bigfatpaulie said:


> Thanks folks!
> 
> Jamie, how is your purdy build going?


 
  
 Hi Paul
  
 Crack building is on pause this week as I am working away from my workshop during the day so not able to progress it. I don't want to take it home to work on in the evenings to do any soldering due to a little one.  Evening times are for them also.
  
 Come Monday the rush will be over and I will have a few long lunch breaks to catch up with the build and hopefully by the end of next week I might have it up and running.


----------



## JamieMcC

Thinking about Bottleheads Quickie but my grasp of all things hifi is not to good and also I only have a old integrated amp,  Apparently its possible to bypass the integrated's preamp section and run the signal to the Quickie instead by using the tape in-outputs, tape rec out to Quickie and back in through the tape input for play back?  Just wondering if this would be something worth giving a go or not to get some flavour a stand alone pre might bring prior to going down the stand alone power amp route.
  
 Or more than likely I am completely barking up the wrong tree.


----------



## Loquah

jamiemcc said:


> Thinking about Bottleheads Quickie but my grasp of all things hifi is not to good and also I only have a old integrated amp,  Apparently its possible to bypass the integrated's preamp section and run the signal to the Quickie instead by using the tape in-outputs, tape rec out to Quickie and back in through the tape input for play back?  Just wondering if this would be something worth giving a go or not to get some flavour a stand alone pre might bring.
> 
> Or more than likely I am completely barking up the wrong tree.


 
  
 I'm interested to hear a response on this...
  
 Alternatively you could buy a Quickie and try it given how inexpensive and fun the Quickie is!


----------



## palmfish

The Quickie is well known to be inexpensive and fun, but you should not get emotionally attached to it. Do not scrutinize it - just move on...


----------



## ffivaz

jamiemcc said:


> Thinking about Bottleheads Quickie but my grasp of all things hifi is not to good and also I only have a old integrated amp,  Apparently its possible to bypass the integrated's preamp section and run the signal to the Quickie instead by using the tape in-outputs, tape rec out to Quickie and back in through the tape input for play back?  Just wondering if this would be something worth giving a go or not to get some flavour a stand alone pre might bring prior to going down the stand alone power amp route.
> 
> Or more than likely I am completely barking up the wrong tree.




I think it will work, but not bypass the preamp section of your integrated amp. With tape in, you still have volume control and gain from the preamp section, if there is some gain. Some integrated amps have a bypass, some RCAs that connect directly to the amp section. If you connect the quickie to the tape in, or whatever input you like, you will have two gain stages before the amp. If my understanding is correct, it could lead to some distortion. But maybe someone has another explanation.


----------



## Loquah

palmfish said:


> The Quickie is well known to be inexpensive and fun, but you should not get emotionally attached to it. Do not scrutinize it - just move on...


 
  
 I have to agree.
  
 It is fun and I'd recommend it to anyone as exactly that (fun), but I don't see it transforming a system that's already at a good level.
  
 Where I'm loving it is as a volume control for my powered speakers - it makes a great addition in this type of situation where you need volume adjustment for a fixed level power amplifier.


----------



## NightFlight

aeolus kratos said:


> Hello everyone,
> 
> After a pretty long time working fine, my speedballed crack started to have some little problems. When I turned the Crack on today, the tubes did not light up, then I slipped my Crack to see underneath, all the LEDs did not light up too ( that means there were no electricity in the Crack ), even though I pressed the power switch. I changed different power cords but could not help. I swapped the tubes, still did not work. Then I slipped the plate again, did not forget wearing shoes to avoid electric shock. I tried to touch and move the connector pins of the driver tube underneath the plate, then suddenly I was shocked and let the plate fall back to the wood base. But magically, the LEDs and the tubes lighted up again, and the Crack worked perfectly ever since.
> 
> ...


 
  
 [rant]
 Sorry to drag up an old post - I was just searching the thread for unrelated items when I came across this post.
  
 I'd like to iterate a few important points.
  
 Never use your bare hands to poke around live circuits. This goes doubly so for higher voltage circuits. Putting on shoes may not save your life, its just good advice in case you are accidentally shocked. It does not provide protection. Electricity is devilish and it can find the most odd path to ground you never considered. Also, if you are electrocuted and survive you could end up with heart damage.* Electricity is no joke. *
  
 If your poking around in a live circuit to find a short, use a non-conductive device. Better known as a stick. It can be wood or plastic. If wood - make certain its not wet. In fact make certain nothing is wet. If plastic - make certain it is non-conductive! A pen is probably a bad idea.
  
*If you don't know what you are doing and play around with electricity there is a good chance it Darwinism will come into play and you will become a statistic.*
 [/rant]


----------



## bigfatpaulie

nightflight said:


> If your poking around in a live circuit to find a short, use a non-conductive device. Better known as a stick.


 
  
 Haha!  That's amazing!  
	

	
	
		
		

		
			




  
  
  
 Sound advice though.


----------



## palmfish

What about your tongue? Can you use your tongue?


----------



## Doc B.

Reread the safety instructions before you go near the amp again. After you have done that and have disconnected the amplifier from mains power go back and inspect all of the solder joints. It sounds like there was a connection that was not soldered and not making contact, that made contact after the impact of dropping the chassis panel.


----------



## GrindingThud

http://www.ee0r.com/dnl.html



palmfish said:


> What about your tongue? Can you use your tongue?


----------



## Armaegis

palmfish said:


> What about your tongue? Can you use your tongue?


 
  
 Start with a 9V. If you can handle that, try jumper cables. If you're still feeling fine, ok go ahead and lick your crack...


----------



## bigfatpaulie

armaegis said:


> ok go ahead and lick your crack...


----------



## JamieMcC

Looking for a little bit of help because I have just realised I need some kind of switching or splitter box as my dac only has one set of analog outs. At the moment these go to the speaker amp. I don't want to keep plugging in and out cables every time I use the Crack. Any ideas as to what to get would I be after a switch or splitter?
  
 TIA


----------



## brunk

jamiemcc said:


> Looking for a little bit of help because I have just realised I need some kind of switching or splitter box as my dac only has one set of analog outs. At the moment these go to the speaker amp. I don't want to keep plugging in and out cables every time I use the Crack. Any ideas as to what to get would I be after a switch or splitter?
> 
> TIA


 
 Hmm, that's a tricky question. If you don't want to disconnect cables at all, then you will need both.


----------



## ben_r_

Buy another DAC


----------



## dxanex

Anyone tried the HD 700 on a Crack with impressions? I'm thinking of purchasing a pair since the price dropped. According to the folks at Headfonia, the Crack drives the HD 700 as beautifully as it does the HD 650.


----------



## olegausany

HD700 sound really good with Crack. Just make sure to try different tube pairing to get sound you prefer


----------



## UmustBKidn

nightflight said:


> [rant]
> Sorry to drag up an old post - I was just searching the thread for unrelated items when I came across this post.
> 
> I'd like to iterate a few important points.
> ...


 
  
 Amen, brother. As a survivor of multiple high energy shocks (the worst about 3000 volts) I can't agree more. If you're unsure of what you're doing, take it to a shop and let a pro look at it. As much fun as putting your own kit together is, it doesn't qualify you as an electronic technician. Yeah, I know, that might not come across well on this particular list, but it's true. High voltage hurts, and I have the scars to prove it.
  
 Personally, I'm kind of surprised that there is no bottom cover in the Crack kit. I think it's horribly unsafe to leave the bottom cover off of an amp like this. All someone needs to do is pick this thing up the wrong way with a live plug, and you'll be lying on the floor wondering what happened. The first mod on everyone's crack kit should be a bottom cover. Don't lecture me about ventilation.
  
 Ok, I'm going back to lurking now. Sorry for the interruption.


----------



## johangrb

jamiemcc said:


> Looking for a little bit of help because I have just realised I need some kind of switching or splitter box as my dac only has one set of analog outs. At the moment these go to the speaker amp. I don't want to keep plugging in and out cables every time I use the Crack. Any ideas as to what to get would I be after a switch or splitter?
> 
> TIA


 
 http://www.ebay.com/itm/2Pc-Monster-RCA-AV-Audio-Splitter-Plug-Adapter-1-Male-to-2-Female-Gold-Plated-/231097326209?pt=US_Audio_Cables_Adapters&hash=item35ce795a81


----------



## JamieMcC

umustbkidn said:


> Personally, I'm kind of surprised that there is no bottom cover in the Crack kit. I think it's horribly unsafe to leave the bottom cover off of an amp like this. All someone needs to do is pick this thing up the wrong way with a live plug, and you'll be lying on the floor wondering what happened. The first mod on everyone's crack kit should be a bottom cover. Don't lecture me about ventilation.


 
  
 Thank you for a such a simple and important idea it gave me a shiver to think what might happen if inquisitive little hands picked it up!  It is very easy to add some wire mesh for a bottom cover so not to effect the ventilation and give that piece of mind.  Definitely will add this modification to my build.
  








  
	

	
	
		
		

		
		
	


	



  
  
  


johangrb said:


> http://www.ebay.com/itm/2Pc-Monster-RCA-AV-Audio-Splitter-Plug-Adapter-1-Male-to-2-Female-Gold-Plated-/231097326209?pt=US_Audio_Cables_Adapters&hash=item35ce795a81


 
  
 Great thanks I will give them a try.


----------



## Doc B.

I would agree that if you have received multiple high voltage shocks you should be very cautious around anything electronic until you understand why you keep getting shocked and work out something to avoid the problem. Certainly anyone can cover the bottom of the amp quite easily if they feel that would solve a problem for them. Do be sure to include ventilation holes. Please also remember that the tubes get hot and one can get a burn by touching them when they are operating. My advice is even if you put a cover on the bottom and a cage on the top, don't let anyone poke around the amp when it is plugged in, or any of your other gear either. These are DIY kits. If you are taking measurements on a live amp be sure you understand how to do it safely. You need to use some common sense if you take on such a project.We haven't figured out how to package that in a kit yet, so one has an obligation is to provide their own.


----------



## diaBoliQu3

Last few weeks, someone gave me the worst advice I ever get. He asked me to get Crack, and use my credit card. Thanks to that guy, now I'm waiting for my Christmas present even though Santa didn't like me for being naught this year.


----------



## calipilot227

You mean the best advice you've ever gotten


----------



## JamieMcC

Little update I unexpectedly had a afternoon free on Saturday so with some trepidation and a pair of shaky hands was able to make a start on wiring up the crack.
  
 Those pesky little LED's are a tad fiddly but are now in and I haven't melted anything yet and have only burnt me little pinkie once. Up to page 29 now but minus the 22.1K ohm 1W resistor as I did not have the meter with me to check it was correct the bands also looked different to the picture.
  
 Happy to say its been a blast so far.
  
 Also much to my relief my practice soldering was done with some 60/40 solder but for the actual build I have some 63/37 Cardas Eutectic solder.  This turned out to be a lot more user friendly to solder with than the 60/40;
  
 Also who ever gave the tip of using those medical forceps which lock super idea these have been very handy to hold bits steady or use as heat sinks when soldering the LED's and any other bits close to plastic which I might have melted.
  
 Work in progress pic.


----------



## bigfatpaulie

Looks fantastic, well done!  Keep up the good work!


----------



## JamieMcC

Cheers Paul I am kicking back for the rest of the evening and having a beer 
	

	
	
		
		

		
		
	


	




 the Cracks assembled (minus speedball) and I will tackle the resistance and volt checks to tomorrow with fresh eyes . Internals took me about 7hrs total,  4hrs yesterday and 3hrs today.


----------



## mullardpassion

jamiemcc said:


> Cheers Paul I am kicking back for the rest of the evening and having a beer
> 
> 
> 
> ...


 

 Clean build..good job mate. When you're done with the spedball, post some more pics


----------



## bigfatpaulie

And you were worried!


----------



## HMFlol

Hello folks,
  
 quick question. I am thinking of buying a Bottlehead Crack to go with some HD650's relatively soon. Partly because I think they would be a lot of fun, and a great learning experience to build, and also because I've heard that they are an A++ pairing with the 650's.
  
 That said, I will be running them from my PC, which has an ASUS Xonar DX card. I am wondering if that will be sufficient to use, or if I should be looking to pair it with a different DAC? This will be my first foray into tubes, so I am hoping that someone in this forum has experience with that particular setup that might be able to she some light.
  
 Thanks sirs.


----------



## Doc B.

My advice is definitely ask for informed opinions, but change only one piece of gear at a time.


----------



## HMFlol

That seems like good advice. Looking forward to building my Bottlehead Crack this Holiday season.


----------



## Loquah

doc b. said:


> My advice is definitely ask for informed opinions, but change only one piece of gear at a time.


 
  
 Great advice. By starting with a Crack with your existing sound card you can hear the difference made by using the Crack and can then notice the upgrade improvements of a future DAC upgrade.


----------



## JamieMcC

Build update
  
 I have gone and shot myself in the foot while doing the voltage checks (face palms self)!
  
 Resistance checks were all good and very close to those in the spec.
  
 Voltage checks all good and going well until a LED went out while testing the octal socket terminals.
  
 Very fast diagnoses from Caucasian Blackplate (Paul "PB" Birkeland) on the bottlehead forum (Doc must have him hard wired into the computer) with a almost instant response just a few moments later.
  
 Very impressive customer service well done and thank you Bottlehead.
  
 So after a few quick questions and answers it looks like I shorted out the LED on the adjacent high voltage pin with the end of the testing probe.  I am very thankful that nothing more serious was damaged, including myself as this was the very first time I had ever used a multi meter its a good lesson to learn for later on.
  
 Looking on the positive side while I wait for a replacement LED I will be able to finish off the case. Which may not have happened so soon if I had started enjoying listening
 to the Crack.
  
 Edit I meant to add
  
 Be very careful when you start probing your Crack!


----------



## FlySweep

jamiemcc said:


> Be very careful when you start probing your Crack!


 
  
 Must..
  
  
  
 resist...
  
  
  
 opportunity.. for...
  
  
  
 crass...
  
  
  
 jokes..


----------



## bigfatpaulie

Sorry to hear that, Jamie 
	

	
	
		
		

		
		
	


	




.
  
 I have to second your comment about Bottlehead service.  When I posted a question here about the SpeedBall assembly, Doc answered in minutes.  When I purchased the unit, Eileen was friendly and prompt both over email and on the phone.  I suspect Bottlehead is having a hard time filling orders for some of their items and it is with good reason.


----------



## Doc B.

Thanks for the kind words guys. We do continually run behind on delivery. It makes some folks a little perturbed in the era of Amazon free two day shipping (for only $70 a year) and Netflix streaming HD movies (with no surround sound). But this isn't a mass market product we are offering. We carefully prep and pack everything in house, I even brush all the chassis panels myself. This year we hired more staff to concentrate on order fulfillment (Josh) and one of the benefits has been about a 27% increase in business. So we kinda ended up at status quo on delivery time even with the extra help. That said, we are as caught up right now as we have been in a few months. Some of you might not know we have a delivery status web page linked to our shopping cart's main page, that gets updates whenever we complete a packing and shipping run. You can look at where we are at on orders and get some feel for how long the wait might be for your kit.


----------



## ben_r_

doc b. said:


> Thanks for the kind words guys. We do continually run behind on delivery. It makes some folks a little perturbed in the era of Amazon free two day shipping (for only $70 a year) and Netflix streaming HD movies (with no surround sound). But this isn't a mass market product we are offering. We carefully prep and pack everything in house, I even brush all the chassis panels myself. This year we hired more staff to concentrate on order fulfillment (Josh) and one of the benefits has been about a 27% increase in business. So we kinda ended up at status quo on delivery time even with the extra help. That said, we are as caught up right now as we have been in a few months. Some of you might not know we have a delivery status web page linked to our shopping cart's main page, that gets updates whenever we complete a packing and shipping run. You can look at where we are at on orders and get some feel for how long the wait might be for your kit.


 

 ? Doc, Netflix has been streaming 5.1 surround sound for many years now.... LINK


----------



## Doc B.

My understanding is that while the capability is there they stream a lot of 5.1 capable movies in stereo only.


----------



## diaBoliQu3

doc b. said:


> Thanks for the kind words guys. We do continually run behind on delivery. It makes some folks a little perturbed in the era of Amazon free two day shipping (for only $70 a year) and Netflix streaming HD movies (with no surround sound). But this isn't a mass market product we are offering. We carefully prep and pack everything in house, I even brush all the chassis panels myself. This year we hired more staff to concentrate on order fulfillment (Josh) and one of the benefits has been about a 27% increase in business. So we kinda ended up at status quo on delivery time even with the extra help. That said, we are as caught up right now as we have been in a few months. Some of you might not know we have a delivery status web page linked to our shopping cart's main page, that gets updates whenever we complete a packing and shipping run. You can look at where we are at on orders and get some feel for how long the wait might be for your kit.


 

 May I know estimated shipping date for crack that paid 11/20/2013? Hopefully able to get this item before Christmas.


----------



## Doc B.

Unfortunately it is 9 p.m. here and thus I am at home so I have no way of gathering that information. If you would like, contact us tomorrow during business hours and we can give you our best estimate. You can email Eileen at queen at bottlehead dot com or call us at 206-451-4275 from 10-6.


----------



## Shikarikato

For all those Bottlehead Crack owners, what cables do you use? Monoprice, the Bottlehead Power Cord Kit, or something else?


----------



## calipilot227

^ Your guess is correct, for me at least.


----------



## FlySweep

shikarikato said:


> For all those Bottlehead Crack owners, what cables do you use? Monoprice, the Bottlehead Power Cord Kit, or something else?


 
  
 I use the Bottlehead power cord & Blue Jeans Cables (for interconnects).  My Crack rig is "Seattle" through and through.


----------



## diaBoliQu3

doc b. said:


> Unfortunately it is 9 p.m. here and thus I am at home so I have no way of gathering that information. If you would like, contact us tomorrow during business hours and we can give you our best estimate. You can email Eileen at queen at bottlehead dot com or call us at 206-451-4275 from 10-6.


 
 I email her but unfortunately she didn't reply me like the first time I contact her. It's been few days already. She started stop reply my email since I ask too much question regarding shipping etc. Maybe I annoyed her so much. Or else, she's too busy. BTW, thanks. I will email her again.


----------



## bigfatpaulie

shikarikato said:


> For all those Bottlehead Crack owners, what cables do you use? Monoprice, the Bottlehead Power Cord Kit, or something else?


 
  
 I use the stock power cord and a pair of AudioQuest Golden Gate.


----------



## Armaegis

diaboliqu3 said:


> I email her but unfortunately she didn't reply me like the first time I contact her. It's been few days already. She started stop reply my email since I ask too much question regarding shipping etc. Maybe I annoyed her so much. Or else, she's too busy. BTW, thanks. I will email her again.


 
  
 Please be patient. Emailing them every day isn't going to make your package arrive any faster.


----------



## mcandmar

Isn't it thanksgiving or some other public holiday at the moment?


----------



## Doc B.

I talked to Josh, who is in charge of packing. He says a kit ordered last Wednesday will be shipping early to middle of next week. And yes it's Thanksgiving weekend starting tomorrow, when all patriotic Americans worship Turkeys by killing them and eating them and then spend the next three days recovering from it. No, I have no idea why this has not caught on in other countries. But we will not be in the office from Thursday through Sunday.
  
 When I mentioned this to Eileen she said that yes, she had answered your questions and concerns about shipping to Malaysia. She did not however receive your most recent email regarding an inquiry about an estimated ship date. You will receive a tracking number when the kit ships.


----------



## diaBoliQu3

armaegis said:


> Please be patient. Emailing them every day isn't going to make your package arrive any faster.


 
 My email to her:


> Hi E.
> 
> Yes, it's Malaysian phone number. BTW, the complete format is +6016xxxxxxx. I wonder if I can include the bottlehead logo along with the Crack? I forget to include in the shopping cart last time. Any estimated date for shipping?


 
 I sent the email on 22nd Nov, Doc replied me at 28th Nov. It's definitely not everyday for me. And, I just want the date estimation, not to send the package ASAP.


----------



## diaBoliQu3

doc b. said:


> I talked to Josh, who is in charge of packing. He says a kit ordered last Wednesday will be shipping early to middle of next week. And yes it's Thanksgiving weekend starting tomorrow, when all patriotic Americans worship Turkeys by killing them and eating them and then spend the next three days recovering from it. No, I have no idea why this has not caught on in other countries. But we will not be in the office from Thursday through Sunday.
> 
> When I mentioned this to Eileen she said that yes, she had answered your questions and concerns about shipping to Malaysia. She did not however receive your most recent email regarding an inquiry about an estimated ship date. You will receive a tracking number when the kit ships.


 

 Hi Doc, thanks for the answer... I need the estimation date to inform the address owner since he might be away for Christmas, at least he can ask someone else to get the package from the post office.
  
 I guess my email goes to spam box because it's in my sent item. What important the most is now I already know the date, and hopefully built within this year. Malaysian custom and excise can be PITA keeping international parcel for weeks.
  
 Thanks Doc.


----------



## mcandmar

doc b. said:


> And yes it's Thanksgiving weekend starting tomorrow, when all patriotic Americans worship Turkeys by killing them and eating them and then spend the next three days recovering from it. No, I have no idea why this has not caught on in other countries.


----------



## mullardpassion

Eileen is always very helpful...For those who still haven't had their Cracks, please be patient. I waited 3 weeks for my Speedball upgrade to ship some months back, and we're now during the holiday season.


----------



## JamieMcC

Sitting back with a wee dram and just enjoying letting the music flow and boy can the Crack sing even with the standard tubes straight from the off its simply magic.
  
 I can see how easy it is to succumbed to this Crack addiction.
  

  
 Cheers guys





 Jamie


----------



## brunk

jamiemcc said:


> Sitting back with a wee dram and just enjoying letting the music flow and boy can the Crack sing even with the standard tubes straight from the off its simply magic.
> 
> I can see how easy it is to succumbed to this Crack addiction.
> 
> ...


 
 Play some Jane Monheit and get lost in the moment


----------



## JamieMcC

A few pics of the finished Crack


----------



## dxanex

^looks amazing man! Great job 
	

	
	
		
		

		
		
	


	




 Can I ask how you got the black finish on the brushed metal top? Did you re-cut out of new material?


----------



## JamieMcC

brunk said:


> Play some Jane Monheit and get lost in the moment


 
  
 Enjoying getting lost in the moment with Melody at the mo.


----------



## JamieMcC

dxanex said:


> ^looks amazing man! Great job
> 
> 
> 
> ...


 
 Hi thanks, the black finish is the weave pattern from a piece of carbon fibre sheet I had made earlier. Its about 0.4mm thick I glued it to the alloy top plate of the Crack and cut out the holes afterwards with a dremel using the top plate as a guide.


----------



## bigfatpaulie

Holy Crap, Jamie!!!
  
 Looks fantastic!!  Nicely done!  How did you do the border around the amp?
  
 I guess you received the replacement LED?


----------



## Doc B.

Just beautful, Jamie. Love the CF and the abalone


----------



## diaBoliQu3

jamiemcc said:


> Sitting back with a wee dram and just enjoying letting the music flow and boy can the Crack sing even with the standard tubes straight from the off its simply magic.
> 
> I can see how easy it is to succumbed to this Crack addiction.
> 
> ...


 
 The magic water definitely will improve the SQ.


----------



## grrraymond

I really need to finish my base. It's still held together with electrical tape... 

Pondering Speedball, tubes or a DAC upgrade. Given my lack of clarity of thought right now, I'll turn it over to you guys. Which would you upgrade first?


----------



## FlySweep

grrraymond said:


> Pondering Speedball, tubes or a DAC upgrade. Given my lack of clarity of thought right now, I'll turn it over to you guys. Which would you upgrade first?


 
  
 That all depends on what you've got now.. but I'd say Speedball first.. then a DAC.. then tubes.


----------



## grrraymond

I'm using stock tubes and a Fiio E7 as a DAC. I had thought that tubes would make the biggest difference but I'd be tempted to drive straight back in with the Speedball too.


----------



## JamieMcC

doc b. said:


> Just beautful, Jamie. Love the CF and the abalone


 
  
 Thanks Doc the inlay is from a New Zealand species of abalone called Paua (it tastes ok to) it tends to have much more of that iridescent blueness to it. Its very hard to capture the effect with the camera but it simply lights up and sparkles when the sun or light hits it.
  


bigfatpaulie said:


> Holy Crap, Jamie!!!
> 
> Looks fantastic!!  Nicely done!  How did you do the border around the amp?
> 
> I guess you received the replacement LED?


 
  
  
 Cheers Paul
  
 "How did you do the border around the amp"    Very carefully cut a shallow groove around the case and glue the inlay into the grove then bury under lots of clear coat.
  
 The LED story, after I shorted a LED when doing the voltage checks Bottlehead kindly offered to send me a free replacement to the UK but the small amount for postage was higher than buying locally throw in the US Thanksgiving holiday and time for international delivery this most likely added up to well over a week or two for the led to arrive. I decided to see if I could find a UK source and ended up buying 5 for £3 including postage delivered in two days off of ebay!  Farnell also has them at 25p each but had a handling/postage charge of £3.95 on top for next day delivery.
  
http://uk.farnell.com/avago-technologies/hlmp-6000/led-submin-red/dp/1003184?Ntt=led+hlmp+6000


----------



## FlySweep

grrraymond said:


> I'm using stock tubes and a Fiio E7 as a DAC. I had thought that tubes would make the biggest difference but I'd be tempted to drive straight back in with the Speedball too.


 
  
 As has been noted by many here (as well as in my personal experience), the Speedball makes the most significant difference of the three upgrades you're looking at.  I'd recommend a solid, mid-level DAC for the speedball'ed Crack (since it does offer better clarity and resolution than the stock Crack).  I haven't heard the Fiio E7.. so it could be more than capable for your needs.  I prefer to go with a neutral, transparent DAC w/ the Crack (so the only coloration comes from the tube).  An ODAC or Stone Acoustics UD110 would be a great fit, IME.  If you wanted to a bit higher up the price scale, a Bifrost Uber would be a great choice, too.


----------



## JamieMcC

It occurred to me earlier that I didn't mention the feet its hard to spot in the pics but they are not feet but something else.
  
 You may laugh but if you can't guess what they are then here's a little clue!
  

  
 I don't wear them myself but did make these they turned out quiet well, just as good if not better than the ones in the link below.
  
http://store.carbonfibergear.com/ultra-carbon-fiber-ring-original-polished


----------



## Aeolus Kratos

Hi everyone,
  
 Today I've just noticed a little problem from my Crack. After a decent time working perfectly, now my Crack began to cause some 'buzz' sound when I adjust the volume ( turn the volume knob ). The 'buzz' sounds like there is electricity in my headphone and it comes through both channel. I'm not very good at English so I'm trying to describe how it sounds. The 'buzz' sound only shows up when I turning the volume knob, otherwise it's back to dead silent. It's not a very serious problem, but it concerns me a little bit 'cause I'm used to the-total-dead-silent-crack.
  
 Any ideas?

 Thanks in advance,
 Kratos.


----------



## Doc B.

Could be the interconnects. Try unpluggung and replugging them.


----------



## JamieMcC

"Effective electromagnetic shielding"
  
 Edit, post moved to Bottlehead forum, Technical Topics.
  
  
http://www.bottlehead.com/smf/index.php/topic,5320.0.html


----------



## Aeolus Kratos

doc b. said:


> Could be the interconnects. Try unpluggung and replugging them.


 

 Thanks Doc!
  
 Problem was solved. After I tried unplugging and replugging the interconnects as well as turning the volume knob around about 20 times, the buzz noise now disappeared


----------



## dxanex

aeolus kratos said:


> Thanks Doc!
> 
> Problem was solved. After I tried unplugging and replugging the interconnects as well as turning the volume knob around about 20 times, the buzz noise now disappeared




I too had a horrible buzzing/crackling noise coming out of one of my crack builds and I resoldered most of the joints, changed the tubes and even replaced some of the caps. In the end I discovered it was coming from the headphone jack, all I had to do was loosen it up. 

Apparently if it's screwed on too tight you can get terrible distortion.


----------



## UmustBKidn

dxanex said:


> ...
> 
> Apparently if it's screwed on too tight you can get terrible distortion.


 
  
 My boss at work has that problem frequently.


----------



## J-Pak

jamiemcc said:


> Sitting back with a wee dram and just enjoying letting the music flow and boy can the Crack sing even with the standard tubes straight from the off its simply magic.
> 
> I can see how easy it is to succumbed to this Crack addiction.
> 
> ...


 
  
 The new "thing" in hifi seems to be pairing audio gear with whisk(e)y; Linn with their 40th anniversary turntable using Highland Park whisky casks and now Grado. Who is going to be the first to make a Crack using whisk(e)y casks as the base?


----------



## JamieMcC

j-pak said:


> The new "thing" in hifi seems to be pairing audio gear with whisk(e)y; Linn with their 40th anniversary turntable using Highland Park whisky casks and now Grado. Who is going to be the first to make a Crack using whisk(e)y casks as the base?


 
  
 Funny enough I did looked at that after  seeing a Crack which uses a wooden wine box for its case which looked great.  The Whisky cases looked to big and chunky and the older style ones are going for more than I wished to spend. Most of the more modern boxes are single bottle cases which would be small but at a pinch it would be possible to use the branding on sides and make replacement ends to get the width right.


----------



## UmustBKidn

j-pak said:


> The new "thing" in hifi seems to be pairing audio gear with whisk(e)y; Linn with their 40th anniversary turntable using Highland Park whisky casks and now Grado. Who is going to be the first to make a Crack using whisk(e)y casks as the base?


 
  

  
 I do believe you have something there.
 Did you know, you can purchase your very own cask of Jack Daniels?


----------



## mordicai

My Crack is up and running since yesterday and a can't take the headphones off. So much more then I expected. Boy this thing rocks! Awaiting the arrival of my Speedbal; Actually awaiting the day when I get to listen to my Crack with Speedball.


----------



## mordicai

Now I need to find a DAC for the Crack. Using a Fiio E-10 since yesterday, but I can't imagine it's giving me my best sonic bliss. Wish I had an idea when Doc will be releasing his DAC. Probably the day I order a Modi.


----------



## Doc B.

The PC board for the final DAC prototype - what we would call the production prototype and thus identical to what will be in the kit - has been ordered this week. It takes a couple weeks to be built and from there we need to make some small layout changes on the chassis and make sure we don't screw something up in the process. At this moment I would estimate we will be ready to take orders in mid to late January. Release dates have a tendency to be moving targets so that is just a guess, not an announcement.


----------



## bigfatpaulie

Any chance we could see a photo of it when it arrives?  I'm really curious.


----------



## JamieMcC

I have made a start on the speedball upgrade this evening.
  
 Starting with the largest of the three boards. Assembling the components on the board was straight forward. Soldering all the components in the holes on the back side I found a bit more of a challenge, judging the correct amount of solder to feed in and finding out which solder tip worked best took a few try's before it started to come together. If you have done this sort of thing before I would imagine you would find it a doddle. A magnifying glass was essential for reading part numbers and checking on the soldering and also checked the resisters out with the meter.Not starting till late in the evening once the first board was done I was quiet relived and happy saved the other boards for another day and a fresher pair of eyes.


----------



## caracara08

doc b. said:


> The PC board for the final DAC prototype - what we would call the production prototype and thus identical to what will be in the kit - has been ordered this week. It takes a couple weeks to be built and from there we need to make some small layout changes on the chassis and make sure we don't screw something up in the process. At this moment I would estimate we will be ready to take orders in mid to late January. Release dates have a tendency to be moving targets so that is just a guess, not an announcement.


 
  
 I cannot wait.


----------



## dxanex

doc b. said:


> The PC board for the final DAC prototype - what we would call the production prototype and thus identical to what will be in the kit - has been ordered this week. It takes a couple weeks to be built and from there we need to make some small layout changes on the chassis and make sure we don't screw something up in the process. At this moment I would estimate we will be ready to take orders in mid to late January. Release dates have a tendency to be moving targets so that is just a guess, not an announcement.


 

 Any estimate on price yet? Will it be in the same range as the Crack kit?


----------



## Doc B.

Our cost for the DAC PC board alone is about the retail price of the Crack, and then we have to include the battery supply and charging circuit, chassis, wood base, DAC board enclosure, display and other pc boards, connecting cables, jacks, hardware, switches, wire, etc., etc. The kit has not been priced yet because we don't quite have the final parts configuration. But it will cost more than the Crack kit.


----------



## Loquah

jamiemcc said:


> I have made a start on the speedball upgrade this evening.
> 
> Starting with the largest of the three boards. Assembling the components on the board was straight forward. Soldering all the components in the holes on the back side I found a bit more of a challenge, judging the correct amount of solder to feed in and finding out which solder tip worked best took a few try's before it started to come together. If you have done this sort of thing before I would imagine you would find it a doddle. A magnifying glass was essential for reading part numbers and checking on the soldering and also checked the resisters out with the meter.Not starting till late in the evening once the first board was done I was quiet relived and happy saved the other boards for another day and a fresher pair of eyes.


 
  
 Nice neat work, Jamie!


----------



## JamieMcC

The two smaller Speedball boards were a doddle after the large one and took no time at all. What through me initially on the larger board was the size of tip to use on the soldering iron. I had this long slender rounded needle tip and thought it would be ideal, but I just could not get it to transfer any heat into the parts for soldering I was adding a little solder to the tip but it made hardly any difference. Progress improved when the larger tip was used, immediately getting much better joints going back over the previous ones I was not happy with.


----------



## brunk

jamiemcc said:


> The two smaller Speedball boards were a doddle after the large one and took no time at all. What through me initially on the larger board was the size of tip to use on the soldering iron. I had this long slender rounded needle tip and thought it would be ideal, but I just could not get it to transfer any heat into the parts for soldering I was adding a little solder to the tip but it made hardly any difference. Progress improved when the larger tip was used, immediately getting much better joints going back over the previous ones I was not happy with.


 
 I find a 2mm chisel tip to be the workhorse of most any PCB work, including SMD. If you guys don't have one, get one


----------



## JamieMcC

Speedball upgrade now done and I am very pleased with the results.


----------



## skeptic

Congrats Jamie!  When you have a chance, throw on something with a well recorded string bass line.  The improved tightness brought about by the speedball upgrade will be very clear!


----------



## bigfatpaulie

And you were worried, Jamie!!
  
 Well done!  I noticed an immediate and significant difference with the Speedball, well worth the upgrade to me.
  
 Did all the LED's survive?  
	

	
	
		
		

		
			




  
  
 Seriously, though, congratulations on the build!


----------



## JamieMcC

Cheers here are a couple of pics of the installed Speedball.
  
 Creating a bit of space for the nylon standoff took longer than I thought gently coaxing the wires around to create a little bit of space just behind the 12au7 socket its a tight space to work (for me anyhow).  The other challenge was with bending back one of the capacitors I could have done with leaving the legs a little longer which would have given more scope for movement. I only just created enough space  to get the larger board in place something that would have been easy if I had left the legs of the capacitors a little longer.
  

  

  

  
 Time to have a wee dram to celebrate


----------



## Loquah

Congrats Jamie!!


----------



## lup1

Anyone knows when is the next shipping date for the crack ? Im scared I wont get my crack before christmas :/


----------



## Doc B.

Kits will be going out tomorrow and Wednesday.


----------



## MDR30

jamiemcc said:


> Cheers here are a couple of pics of the installed Speedball.
> 
> Creating a bit of space for the nylon standoff took longer than I thought gently coaxing the wires around to create a little bit of space just behind the 12au7 socket its a tight space to work (for me anyhow).  The other challenge was with bending back one of the capacitors I could have done with leaving the legs a little longer which would have given more scope for movement. I only just created enough space  to get the larger board in place something that would have been easy if I had left the legs of the capacitors a little longer.
> 
> ...




"Wee dram" indeed, or a snaps as we say here up north. Well worth it.


----------



## greyhamster

doc b. said:


> Our cost for the DAC PC board alone is about the retail price of the Crack, and then we have to include the battery supply and charging circuit, chassis, wood base, DAC board enclosure, display and other pc boards, connecting cables, jacks, hardware, switches, wire, etc., etc. The kit has not been priced yet because we don't quite have the final parts configuration. But it will cost more than the Crack kit.


 

 When can we pre order the DAC kit? are they tube DAC?


----------



## Doc B.

We will probably start taking pre orders next month. It does not have a tube output. I felt that the sonic quality of this product didn't warrant it.


----------



## skeptic

Can't wait for the formal announcement and details Doc!  The more tidbits I read about your and John's painstaking FPGA design, and John's recent posts on jitter and your careful (and equal) attention to all the various digital input receivers, the more excited I get.  
  
 [edit: typo]


----------



## Loquah

skeptic said:


> Can't wait for the formal announcement and details Doc!  The more tidbits I read about your and John's painstaking FPGA design, and John's recent posts on jitter and your careful (and equal) attenuation to all the various digital input receivers, the more excited I get.


 
  
 Ditto. The design process sounds exhaustive and always focussed on the ultimate sound output. Can't wait!


----------



## mordicai

Cancelled my Havana Dac today to wait on the new BH Dac. My E-10 will have to do for now.


----------



## JamieMcC

Thought I would try the easy to do mod of soldering in a couple of 270K resistors inline with the RCA inputs as per Paul's suggested mod in the Crack FAQ section. Using a Vishay 270K, 5%, 0.25W Metal Film and it works a treat.

 Resulted in a feeling of having improved range and finer user control of the volume levels it also removed a very slight channel imbalance which was noticeable at the lowest level.


----------



## Shaldome

In order to upgrade my headphone equipment I decided to get my self a Crack, which will go along with my newly Order Beyerdynamic T1(which will of course arrive tomorrow while I am still at work). At the moment I have some Sennheiser HD 650 and an ODAC/AMP combo from Epiphany. What I did not consider and totally forgot was, that this combo only has an headphone out for a connection to the Crack, which I understand is not a good option, as the the signal goes through the amp of the ODAC/AMP first before going into the Crack.
  
 Now my question is, what are my best options until around the middle of next year, when my Geek Pulse should arrive, to remedy the situation.
  
 First would be, still use the headphone out of the ODAC/AMP into the crack.
  
 Second would be, plug back in my Asus Xonar ST and use the output into the Crack.
  
 Third would be use the onboard sound outputs into the Crack, but that would not make much sense, when I can use the Xonar.
  
 So any help would be appreciated to help me in this matter.


----------



## Mahdi8

One option would be take out the odac and put it in its own enclosure


----------



## ben_r_

Does anyone out there with a Crack and installed Speedball have any noise or hum when the volume is turned up say 75% or higher? I have a bit of noise when the volume pot is up that high and I had my buddy bring his over and he has no noise but a humming sound at that same volume level. Now I know there is no way anyone who isnt WAY hard of hearing would ever need to turn the volume up that high and yes both amps are dead silent until you get to those high volumes, I was just kinda wondering if anyone else's did the same thing. Oh and these effects were heard in multiple places around my house to eliminate the possibility of external noise, with and without a source/RCA cables plugged in and I even removed my Speedball and put the Crack back to stock on mine and it was dead silent all the way up so I know the slight noise at 80%+ volume on mine at least comes from the Speedball upgrade. All voltages and resistance checks look good with Speedball in and I have been soldering for well over 20 years so I know its not a build issue. I suppose it might be one of the components in the Speedball boards but I just wanted to ask around and see if anyone else was experiencing the same before I worry any further about it. As I mentioned its only with no music playing and the volume way higher I would EVER turn it up to.


----------



## Loquah

mahdi8 said:


> One option would be take out the odac and put it in its own enclosure


 
  
 This is a good option, but the Xonar is also a good option in the interim. Perhaps try both to see which sound you prefer.
  
 Alternatively, there are some excellent, cheap DACs around like the ODAC (by itself) and some of the current DAPs offer excellent line-out capabilities if you don't necessarily need to use your computer as a source


----------



## palmfish

There's nothing wrong with using the headphone out from the O2. It might even give you more play with the Cracks volume control.


----------



## UmustBKidn

shaldome said:


> In order to upgrade my headphone equipment I decided to get my self a Crack, which will go along with my newly Order Beyerdynamic T1(which will of course arrive tomorrow while I am still at work). At the moment I have some Sennheiser HD 650 and an ODAC/AMP combo from Epiphany. What I did not consider and totally forgot was, that this combo only has an headphone out for a connection to the Crack, which I understand is not a good option, as the the signal goes through the amp of the ODAC/AMP first before going into the Crack.
> 
> Now my question is, what are my best options until around the middle of next year, when my Geek Pulse should arrive, to remedy the situation.
> 
> ...


 
  
 You didn't mention whether or not you were considering a new DAC?
  
 It appears your Asus sound card has RCA line out jacks. Personally, I'd just use the RCA line out jacks from your Asus sound card, and plumb them into your Crack.
  
 Some folks say that the choice of DAC and cans has a greater impact on the total sound quality than your amplifier. If you're willing to drop $1k on cans and $300 on an amp, I'd drop a few bills for a good DAC to go with the other fine gear.
  
 Using a headphone output will double-amp the sound and introduce distortion. It's also possible to over-drive an amp if you turn the headphone output up too much. You have a usable DAC on that sound card, that's the way I'd go. I'd also recommend you spend some money on a better DAC.


----------



## Shaldome

umustbkidn said:


> You didn't mention whether or not you were considering a new DAC?
> 
> It appears your Asus sound card has RCA line out jacks. Personally, I'd just use the RCA line out jacks from your Asus sound card, and plumb them into your Crack.
> 
> ...


 

 Thanks for the suggestions so far.
 As I already wrote, I will have a http://www.indiegogo.com/projects/geek-pulse-a-digital-audio-awesomifier-for-your-desktop Geek Pulse X coming sometimes next year, so the solution would just be temporary. As such, another DAC would be a kind of a waste.
 I guess I will think about another amp at the end of next year, depending on how satisfied I am with the Pulse.
 The Crack was actually a buy out of curiosity and something to hold me over until the Pulse arrives.


----------



## gikigill

The Crack will be a very diferent animal.
  
 I currently have the SEX and waiting for the fully loaded Pulse X with femto, active/passive and LPS4 and not expecting them to
  
 match each other at all.


----------



## Shaldome

gikigill said:


> The Crack will be a very diferent animal.
> 
> I currently have the SEX and waiting for the fully loaded Pulse X with femto, active/passive and LPS4 and not expecting them to
> 
> match each other at all.


 

 I thought as much, but this was more meant as an answer to the DAC questions. Of course I will still be using the Crack when my Pulse arrives. And then maybe later next year I will take a look if I go up a step or two from the Crack.


----------



## JamieMcC

ben_r_ said:


> Does anyone out there with a Crack and installed Speedball have any noise or hum when the volume is turned up say 75% or higher? I have a bit of noise when the volume pot is up that high and I had my buddy bring his over and he has no noise but a humming sound at that same volume level. Now I know there is no way anyone who isnt WAY hard of hearing would ever need to turn the volume up that high and yes both amps are dead silent until you get to those high volumes, I was just kinda wondering if anyone else's did the same thing. Oh and these effects were heard in multiple places around my house to eliminate the possibility of external noise, with and without a source/RCA cables plugged in and I even removed my Speedball and put the Crack back to stock on mine and it was dead silent all the way up so I know the slight noise at 80%+ volume on mine at least comes from the Speedball upgrade. All voltages and resistance checks look good with Speedball in and I have been soldering for well over 20 years so I know its not a build issue. I suppose it might be one of the components in the Speedball boards but I just wanted to ask around and see if anyone else was experiencing the same before I worry any further about it. As I mentioned its only with no music playing and the volume way higher I would EVER turn it up to.


 
  
 Yes I have a slight hum at about 75% volume but I am not sure if its the speedball or not. I do know that without the speedball my Crack was silent right up to 100%.
 I only noticed the hum after soldering in a couple of 270K resistors inline with the RCA inputs as per a suggested mod in the Crack FAQ section. So I thought it was that, I plan to take them out soon when I fit a pot upgrade so will check when removed if the hum is still present.


----------



## ben_r_

jamiemcc said:


> Yes I have a slight hum at about 75% volume but I am not sure if its the speedball or not. I do know that without the speedball my Crack was silent right up to 100%.
> I only noticed the hum after soldering in a couple of 270K resistors inline with the RCA inputs as per a suggested mod in the Crack FAQ section. So I thought it was that, I plan to take them out soon when I fit a pot upgrade so will check when removed if the hum is still present.


 

 Sounds good. That would be helpful to know as well.
  
*Anyone else get a chance to test this out? Perhaps in particular with a set of HD-650's as the load? Turn your Crack w/ Speedball up to around 75% max volume and then all the way to 100% and let us know if you hear a hum or noise in your headphones with NO source (NO RCAs) connected.*


----------



## MattTCG

Just finished the entire thread. 
	

	
	
		
		

		
			





 Now working on joing the club...


----------



## brunk

matttcg said:


> Just finished the entire thread.
> 
> 
> 
> ...


 
 Cheers man.


----------



## bdr529

Joined the club last week


----------



## JamieMcC

bdr529 said:


> Joined the club last week


 
 Nice work and a super pick of the tubes glowing.
  
 Happy New Year all


----------



## gikigill

matttcg said:


> Just finished the entire thread.
> 
> 
> 
> ...


 
  
 I,ve heard Loquah,s Crack and you wont regret joining us. I would suggest the Crack amd them the SEX/Mainline.
  
 Currently listening to a SEX and its fabulous.


----------



## bdr529

jamiemcc said:


> Nice work and a super pick of the tubes glowing.
> 
> Happy New Year all




Thanks, Happy New Years


----------



## MattTCG

I've found lot's of information on the output tube and have purchased a 5998. But what is the recommendation for the other tube? Is the stock okay?
  
 Suggestions are welcome...


----------



## Aeolus Kratos

Crack + T1 addiction...


----------



## brunk

matttcg said:


> I've found lot's of information on the output tube and have purchased a 5998. But what is the recommendation for the other tube? Is the stock okay?
> 
> Suggestions are welcome...


 
 Get a 12BH7, so long as you're getting Speedball. It's super quiet and they are actually still reasonably priced


----------



## brunk

aeolus kratos said:


> Crack + T1 addiction...
> 
> 
> 
> ...


 
 Looks like you're starting him off right!


----------



## RAZRr1275

How do the HD650 and the Crack compare to the HD800 and the Crack? I like to have a darker headphone and a brighter headphone around and I was wondering if they'd be good foils to each other or if I'd think that one of them absolutely destroys the other.


----------



## reked

Hey guys.
  
 I currently have a HD650 and in the market looking for an amp for it. Just a question, how difficult would the crack be to assemble with absolutely no soldering experience whatsoever?


----------



## FlySweep

bdr529 said:


> Joined the club last week


 
  
 Great pic.. I dig the dark base.. and the glow of the 5998 is so damn sexy.
   





matttcg said:


> I've found lot's of information on the output tube and have purchased a 5998. But what is the recommendation for the other tube? Is the stock okay?
> 
> Suggestions are welcome...


 


brunk said:


> Get a 12BH7, so long as you're getting Speedball. It's super quiet and they are actually still reasonably priced


 
  
 What Brunk said.. 12BH7's are renowned for having no microphonics... a great choice to have (at least one) if you've got the speedball installed.
  
 I've made recco's on the 650 thread as far as input tubes go.. if you're going to be using the 650 w/ the Crack (and a 5998 for the output tube), I think an RCA "black plate" 12AU7 (or the "clear top") is a must hear combo.. stunning sound.  The Mazda CIFTE 12AU7 was bad ass with the 650, too.. great for electronica/hip hop/rock.


----------



## JamieMcC

reked said:


> Hey guys.
> 
> I currently have a HD650 and in the market looking for an amp for it. Just a question, how difficult would the crack be to assemble with absolutely no soldering experience whatsoever?


 
  
 I completed mine last month and had never soldered or used a multimeter before the instructions are excellent and easy to follow with  lots of pictures for each step
  
 Watch Tyll Hertsens InnerFidelity Crack build video for tips on how to do the connections and soldering.


----------



## Nic Rhodes

Is your base stained or a new wood? Just done some in Wenge and Black Walnut to try but am not sure how to finish them atm.


----------



## MattTCG

brunk said:


> Get a 12BH7, so long as you're getting Speedball. It's super quiet and they are actually still reasonably priced


 
  
  


flysweep said:


> Great pic.. I dig the dark base.. and the glow of the 5998 is so damn sexy.
> 
> What Brunk said.. 12BH7's are renowned for having no microphonics... a great choice to have (at least one) if you've got the speedball installed.
> 
> I've made recco's on the 650 thread as far as input tubes go.. if you're going to be using the 650 w/ the Crack (and a 5998 for the output tube), I think an RCA "black plate" 12AU7 (or the "clear top") is a must hear combo.. stunning sound.  The Mazda CIFTE 12AU7 was bad ass with the 650, too.. great for electronica/hip hop/rock.


 
  
 Thanks guys!! Could you provide some recommended sources?
  
 How about this:
  
http://www.ebay.com/itm/RCA-12AU7-ECC82-VACUUM-TUBE-1956-BLACK-PLATE-D-FOIL-GTR-SINGLE-RARE-SWEET-223-/221330280792?pt=Vintage_Electronics_R2&hash=item3388501158


----------



## skeptic

Off the cuff, I prefer my 1950's tung sol 12bh7 to the rca's I've heard.  For that matter, old stock tung sol 12au7's also sound great and can be had quite cheap on ebay.
  
 I would describe both the 12au7 and 12bh7 tung sols as very clean, neutral tubes.  By comparison, my amperex bugle boy 12au7 and 1950's rca 12bh7 are a little warmer/less extended by comparison.  Alternatively, I hear my rca clear top and mullard shield logo 12au7's as having slightly brighter trebles than the tung sols.  I don't particularly care for my 1960's rca grey plate 12bh7 but have trouble putting my finger on exactly what it is about the sound that I find less appealing than most of the others.  
  
 At the end of the day, my best advice is to buy a handful of cheap tubes on ebay and see what you like.  Tubes that read "strong" as opposed to nos are just fine.  These things are good for thousands of hours of use.


----------



## bdr529

I am using a Tungsol 12BH7A that is rebranded as "Regency" in mine right now.

To be honest I have a real hard time hearing a difference switching the drive tubes, but this one looks the best so far haha . It is the one in the picture I posted last night.. Anyway all three drive tubes that I have sound good and are equally quiet. The other two I have are RCA 12BH7A long black plate and a GE 12AU7A.


----------



## Doc B.

RE the "there is a tiny bit of hum when I turn the amp up far louder than I would set it to listen to music" -

The Speedball upgrade increases the gain of the circuit and thus the noise floor will be amplified a bit more. Thus it may just hit the threshold of hearing if you turn the volume up far louder than you should for listening.


----------



## ben_r_

doc b. said:


> RE the "there is a tiny bit of hum when I turn the amp up far louder than I would set it to listen to music" -
> 
> The Speedball upgrade increases the gain of the circuit and thus the noise floor will be amplified a bit more. Thus it may just hit the threshold of hearing if you turn the volume up far louder than you should for listening.



Got it and that makes complete sense. It's kinda what I was assuming but I was just curious if everyone else experienced the same thing. Then when my friends made a distinct hum sound and mine made a more normal shhhhhh noise sound I was thrown off since they were two very different sounding noises.


----------



## Solarium

I know the consensus that BTH crack is amazing with the HD650, which I currently have. I plan to eventually upgrade to HD800 and the HE-500 sometimes down the road, how does the BTH crack handle those HP's?


----------



## MattTCG

^^ Won't work at all. Bottlehead sells other amps for planar magnetic hp's.


----------



## olegausany

But great for HD800


----------



## skeptic

olegausany said:


> But great for HD800


 
  
 x2.  To my ears, it's one of the best budget hd800 amps out there in fact.  
  
 If you're looking for an absolute end game setup for hd800's (and that will also handle orthos), mainline is what you want.  It is phenomenal - except for the part where I can't tare myself away from listening at night and wind up sleep deprived and/or with wife aggro.  All in all, a nice problem to have.


----------



## olegausany

skeptic said:


> x2.  To my ears, it's one of the best budget hd800 amps out there in fact.
> 
> If you're looking for an absolute end game setup for hd800's (and that will also handle orthos), mainline is what you want.  It is phenomenal - except for the part where I can't tare myself away from listening at night and wind up sleep deprived and/or with wife aggro.  All in all, a nice problem to have.


 

 HD800 are my end game headphones and I have no interest in orthos for my desktop setup and S.E.X. handles HD800 for me from speakers taps but I still would be interested to hear mainline.


----------



## MattTCG

Despite my love of planar magnetic hp's, the hd650 with crack could be my end game.


----------



## rtwilner

I have to admit not reading all 3500 posts in this thread...
  
 Like many, I would be using this amp close to my computer.  Are there any issues with interference from lack of shielding ("gravity mounted" wooden chassis)?


----------



## MattTCG

None that I have heard of.


----------



## gikigill

Nope, mine sits next to a solid state amp and the computer without any problems.


----------



## JamieMcC

I had been watching this lot of 6080's on ebay for the last week they had been around $15 and ended up going for $358.40 which still looks a good price but more than I wanted to give to try one for rolling in the Crack


----------



## palmfish

rtwilner said:


> I have to admit not reading all 3500 posts in this thread...
> 
> Like many, I would be using this amp close to my computer.  Are there any issues with interference from lack of shielding ("gravity mounted" wooden chassis)?


 
  
 I did get interference placing my Crack next to my Squeezebox Touch. I moved it 3 feet away and it's fine now.


----------



## PTom

What's a reasonable price for a second hand BHC with a speedball upgrade? Is $550 too much? I don't think I'd be able to build it myself so I'm looking for an assembled one .


----------



## MattTCG

I posted an ad here and asked for someone to do the build. I got lots of responses. Your price is in the ballpark.


----------



## ben_r_

jamiemcc said:


> I had been watching this lot of 6080's on ebay for the last week they had been around $15 and ended up going for $358.40 which still looks a good price but more than I wanted to give to try one for rolling in the Crack


 

 Wait huh? 8 6080s for $350?! Arent they like $10 each from Bottlehead?


----------



## GrindingThud

7 of them are the nice super heavy duty graphite plate tubes.....worth $50 to $80 these days if you can find them at all. 


ben_r_ said:


> Wait huh? 8 6080s for $350?! Arent they like $10 each from Bottlehead?


----------



## Nic Rhodes

yes I was outbid on these!


----------



## JamieMcC

nic rhodes said:


> yes I was outbid on these!


 
 Me as well at I was watching 4s to the end it went from US $107.00 just as I was placing my max bid of $160 to US $358.40
  
 Quiet rare to see that many of the Bendix slotted plates together.
  
 Guess we were all hoping no one else had noticed them lol.


----------



## ben_r_

Jeez, thats a lot of money for 6080s IMO just for a better build quality. Save up your money and get a 5998 and be done with it. Thats what I did.


----------



## Nic Rhodes

jamiemcc said:


> Me as well at I was watching 4s to the end it went from US $107.00 just as I was placing my max bid of $160 to US $358.40
> 
> Quiet rare to see that many of the Bendix slotted plates together.
> 
> Guess we were all hoping no one else had noticed them lol.


 
 mine was the $107! missed the TS earlier as well


----------



## JamieMcC

nic rhodes said:


> mine was the $107! missed the TS earlier as well


 
  
 Sorry about the TS if its the ones that ended 30 Dec, 2013 17:18:54


----------



## PTom

matttcg said:


> I posted an ad here and asked for someone to do the build. I got lots of responses. Your price is in the ballpark.


 
 What was the range of prices you were offered? Also without the speedball upgrade got any ideas how much a second hand one goes for? 
  
 Don't you think it's bit risky paying so much since I'm guessing there's no warranty?


----------



## MattTCG

Let's take this to pm. ^^


----------



## JamieMcC

ben_r_ said:


> Does anyone out there with a Crack and installed Speedball have any noise or hum when the volume is turned up say 75% or higher? I have a bit of noise when the volume pot is up that high and I had my buddy bring his over and he has no noise but a humming sound at that same volume level. Now I know there is no way anyone who isnt WAY hard of hearing would ever need to turn the volume up that high and yes both amps are dead silent until you get to those high volumes, I was just kinda wondering if anyone else's did the same thing. Oh and these effects were heard in multiple places around my house to eliminate the possibility of external noise, with and without a source/RCA cables plugged in and I even removed my Speedball and put the Crack back to stock on mine and it was dead silent all the way up so I know the slight noise at 80%+ volume on mine at least comes from the Speedball upgrade. All voltages and resistance checks look good with Speedball in and I have been soldering for well over 20 years so I know its not a build issue. I suppose it might be one of the components in the Speedball boards but I just wanted to ask around and see if anyone else was experiencing the same before I worry any further about it. As I mentioned its only with no music playing and the volume way higher I would EVER turn it up to.


 
  
 OK I have some new info on this which may or may not be of help in your case but it worked for me.
  
 I removed my resistors from the rca inputs to bring my BHC+Speedball back to stock my hum was still present, I messed about turning on and off equipment methodically disconnecting listening etc no joy.
  
 Today I moved the Crack downstairs and had it connected up to the turntable (sounds sublime) but still had hum at way above listening levels. Later I moved the crack back upstairs connected up and the hum has changed. It was intermittent something had changed at first I thought it might be tube related but after changing a few it was not. The hum seemed more microphonic related as it started when the volume was turned up past half way but if you let go of the volume knob after a few seconds the hum decreased.
  
 Here's the thing my Crack+Speedball is dead silent now at all levels.
  
 The fix,
  
 I twisted my rca input cables together that run from the dac to the Crack and made sure they where routed directly away from the transformer.
  
 It was that simple!  I just happened to noticed when I reconnected I had a twist in the cable and as reached across to turn volume knob my elbow sometimes would move the cables. I wondered about how the internal input wiring is braided to help cancel out interference. So twisted up the connecting rca cables and no noise.
  
 Hope this helps you as well


----------



## Nic Rhodes

jamiemcc said:


> Sorry about the TS if its the ones that ended 30 Dec, 2013 17:18:54


 
  not those but I think I was a bidder, there were 8 from the same seller as the Bendix 10 mins earlir...


----------



## mordicai

You have to realize its 275 + 125 + shipping + solder and tools to build it + a couple of days to build it+ putting the base together and finishing it +sanding and finishing  the aluminum plate. I wouldn't sell mine for 550, thats for sure. I would think closer to 700. Suck it up and build it yourself. VERY EASY!!


----------



## JamieMcC

nic rhodes said:


> not those but I think I was a bidder, there were 8 from the same seller as the Bendix 10 mins earlir...


 
  
  Ah yes I know which TS ones you mean now I did not bid on them or save to watch list. What did they go for in the end?


----------



## Nic Rhodes

$80, $10 a tube. Look good through.


----------



## ben_r_

jamiemcc said:


> OK I have some new info on this which may or may not be of help in your case but it worked for me.
> 
> I removed my resistors from the rca inputs to bring my BHC+Speedball back to stock my hum was still present, I messed about turning on and off equipment methodically disconnecting listening etc no joy.
> 
> ...


 

 I will def try that with a set of RCA cables, but I was getting the noise and/or hum with no RCA cables plugged in. Cant remember now if we tried it them plugged in but I will do a bit more experimenting when I get a chance. Thanks for the update!


----------



## ben_r_

mordicai said:


> You have to realize its 275 + 125 + shipping + solder and tools to build it + a couple of days to build it+ putting the base together and finishing it +sanding and finishing  the aluminum plate. I wouldn't sell mine for 550, thats for sure. I would think closer to 700. Suck it up and build it yourself. VERY EASY!!


 

 You would think that thats what they would go for, but there have been a few people on HeadFi selling them as well as quite a few on eBay that I have seen listed and they never seem to actually sell for anymore than $450 assembled and with the Speedball from what I have seen.


----------



## JamieMcC

ben_r_ said:


> I will def try that with a set of RCA cables, but I was getting the noise and/or hum with no RCA cables plugged in. Cant remember now if we tried it them plugged in but I will do a bit more experimenting when I get a chance. Thanks for the update!


 
  
 So was I with no cables, dead silent now.


----------



## Doc B.

jamiemcc said:


> OK I have some new info on this which may or may not be of help in your case but it worked for me.
> 
> I removed my resistors from the rca inputs to bring my BHC+Speedball back to stock my hum was still present, I messed about turning on and off equipment methodically disconnecting listening etc no joy.
> 
> ...


 
 FWIW our interconnect cabling was chosen specifically for its resistance to interference from transformers. And re the Bendix/Tung-Sol graphite plates, I've had a bunch of them for years. They are pretty good but I wouldn't say they are something to lust after.


----------



## JamieMcC

Bottlehead promote hifibuilderguy on their website who will assemble a kit for you. For a fully built BHC+SB assembled with cleared base painted top and blued transformer housing you will need to spend around $800 plus delivery.
  
https://www.facebook.com/hifibuilderguy
  
  
 If outside the US then add higher shipping, customs import duties, value added tax  and then handling fees from your own parcel post service.
  
  
 $5-600 used sounds fair for a good standardly built one. If its an especially good build, custom case, upgraded pots, film capacitors, upgraded tubes. Factor in a much, much more. I expect from reading the forums there are more than a few customised BHC's that are nudging in on $1000 or more for parts alone.


----------



## MattTCG

Can someone please explain to me how each tube section effects the sound of the amp? I am somewhat confused on this matter.
  
 thanks...


----------



## ben_r_

jamiemcc said:


> So was I with no cables, dead silent now.


 

 Okay thanks, will do some more testing.


----------



## JamieMcC

doc b. said:


> FWIW our interconnect cabling was chosen specifically for its resistance to interference from transformers. And re the Bendix/Tung-Sol graphite plates, I've had a bunch of them for years. They are pretty good but I wouldn't say they are something to lust after.


 
  
 Thanks Doc, the Bendix/Tung-Sol slotted graphite plates were simply listed as 6080s you needed sharp eyes to note they were the more sought after Bendix slotted plate type. So an opportunity was present to grab a bargain or not as it turned out. Still that's all just part of the fun of the chase.


----------



## Doc B.

jamiemcc said:


> Bottlehead promote hifibuilderguy on their website who will assemble a kit for you. For a fully built BHC+SB assembled with cleared base painted top and blued transformer housing you will need to spend around $800 plus delivery.
> 
> https://www.facebook.com/hifibuilderguy
> 
> ...


 
 Firstly, I am a hardcore DIY guy thus I think everyone should really build their own amp. If I didn't think so we wouldn't be selling kits. One thing to bear in mind when determing a fair price for a used amp is that there's somewhat of a Catch 22 in buying used. Buying a used amp because you feel you are not technically competent to build one can mean buying someone else's first build. That doesn't seem like a very good way to guarantee never having to go under the hood, and it can take more effort to fix someone else's mistakes than your own. I would at the very least ask the seller what kind of guarantee they offer that the amp works 100%. Shawn (hifibuilderguy) has built more Crack amps than anyone on the planet. And his stuff is guaranteed. So yes, it costs more for sure, but on the other hand you are buying something that you know will work for the long run. 
  
 Also remember that if you decide to build it yourself you can go on the forum and we'll help you if you have any issues. If you buy something used and it doesn't work and you don't want to have to fix it yourself via the forum, you're looking at paying another $125 to us on top of what you spent on it to have us fix it for you.


----------



## MattTCG

doc b. said:


> Firstly, I am a hardcore DIY guy thus I think everyone should really build their own amp. If I didn't think so we wouldn't be selling kits. One thing to bear in mind when determing a fair price for a used amp is that there's somewhat of a Catch 22 in buying used. Buying a used amp because you feel you are not technically competent to build one can mean buying someone else's first build. That doesn't seem like a very good way to guarantee never having to go under the hood, and it can take more effort to fix someone else's mistakes than your own. I would at the very least ask the seller what kind of guarantee they offer that the amp works 100%. Shawn (hifibuilderguy) has built more Crack amps than anyone on the planet. And his stuff is guaranteed. So yes, it costs more for sure, but on the other hand you are buying something that you know will work for the long run.
> 
> Also remember that if you decide to build it yourself you can go on the forum and we'll help you if you have any issues. If you buy something used and it doesn't work and you don't want to have to fix it yourself via the forum, you're looking at paying another $125 to us on top of what you spent on it to have us fix it for you.


 
  
 I'm sorry but I have to say that this line of thinking doesn't hold much water with me...all due respect given. On one hand you suggest that anybody could build the kit or you wouldn't be selling them. In the same breath you say that you wouldn't want to buy someone's mistakes. 
  
 Please appreciate some of us don't have the expertise and or time to build the amp. I don't see that many first timers would be offering to build someone a crack on their first build regardless. Additionally anyone asking to have a kit build from someone with no experience should realize the risk with even the smallest dose of common sense.


----------



## PTom

I'd really like to build it if it wasn't so expensive. What's the worst case scenario? During a build how easy is it to permanently damage the BHC?


----------



## Doc B.

Well on the one hand you say you don't think you have the skills to build a kit, but you're willing to buy from some other guy who may or may not have the skills. But this kind of argument doesn't really get you closer to a decision I suspect. What I said was I think everyone should build their own kit. That is a determination I have made. I did not say that everyone feels capable of doing it. That's something you have to determine for yourself. After all the years we have been helping first timers I do know that anyone who wants to build one of our kits has the expertise necessary build one of our kits, with maybe the few exceptions being people who are terminally hard headed and won't follow instructions.
  
 If you build a kit and maybe even screw it up and sort out your own mistakes, you have an accomplishment to be proud of and you will live with the imperfections. My points about the caveats of someone else building were with reference to buying used, not hiring someone to build it for you. There are kits that are built very well on ebay and also kits that get built and the guy is never motivated enough to ask for help when he has problems with his build. I can say from experience that those amps do end up on ebay from time to time too, and they often come to us for repair after the sale though sold as fully functional. 
  
 Hiring somone to build your gear for you is fine. I think you will miss a major part of the fun of owning the gear, but that is simply my opinion. And we will be there if the build you commission doesn't work out to your expectations.


----------



## mordicai

I built my first Crack last month.  Bought a nice soldering station, a few really cheap tools, practiced for a hour or so soldering up a bunch of junk. Don't know a resister from a condenser. My 7 year old grandson with a little help from grandpa could follow the SIMPLE directions. The pay off for me is  Wow what a great sound. Smooth......I loved designing how I wanted my Crack to look.....black walnut ( almost ebony) wooden base; light green aluminum rustoleam paint on top.... been looking on the net for a month for the right gain knob. Had a couple of questions. Got on the web site and usually within 20 minute. I have a totally different relationship with  this Amp then I would with anything a bought. I'm not pushing Bottlehead here, I pushing the hobby of DIY high definition audio. Fun!


----------



## mordicai

Started my Speedball today and need to buy a stronger magnifier.  I feel like I'm a brain surgeon.  The next level in miniaturized electronic's is going to be a blast to build. By the way, I'm 73 with only vision in one eye. If I can do it, you can.


----------



## JamieMcC

doc b. said:


> Firstly, I am a hardcore DIY guy thus I think everyone should really build their own amp. If I didn't think so we wouldn't be selling kits. One thing to bear in mind when determing a fair price for a used amp is that there's somewhat of a Catch 22 in buying used. Buying a used amp because you feel you are not technically competent to build one can mean buying someone else's first build. That doesn't seem like a very good way to guarantee never having to go under the hood, and it can take more effort to fix someone else's mistakes than your own. I would at the very least ask the seller what kind of guarantee they offer that the amp works 100%. Shawn (hifibuilderguy) has built more Crack amps than anyone on the planet. And his stuff is guaranteed. So yes, it costs more for sure, but on the other hand you are buying something that you know will work for the long run.
> 
> Also remember that if you decide to build it yourself you can go on the forum and we'll help you if you have any issues. If you buy something used and it doesn't work and you don't want to have to fix it yourself via the forum, you're looking at paying another $125 to us on top of what you spent on it to have us fix it for you.


 
  
 That is a good point Doc and really stems down to how each of us attributes value and we will all have different ideas on that. But its also kind of unique from the stand point that we have your input as the head of Bottlehead engaged so directly with those here who are interested in your kits.
  
 Mordicai;s comment  "I have a totally different relationship with this Amp then I would with anything bought." is very much how I feel and is a hidden part for of the value of BH diy ownership that is not looked at in $ terms but does have a value of its own which is connected to the BH forum and the connectivity that is there with yourself , PB,PJ and Joshua etc the very guys who directly are involved in the design and production of parts etc not forgetting the many other knowledgeable posters from my perspective this is one of Bottleheads most attractive aspects and of immense value.


----------



## bigfatpaulie

I'm sorry to hijack this thread, but I have a 'noobie toobie' question (groan).
  
 Pictured below is the 12au7a I received with my Crack.  The glass (from what I remember) was completely clear all around the tube.  
  
 Anyway, not too long ago I started noticing some intermittent crackling or scratching.  I recently picked up a Telefunken ECC82 and I haven't noticed the crackling noise with that tube.  Is my original tube kicking the bucket?  I purchased the Crack (new) in November, so was it a faulty tube to begin with?  Or is there something I did wrong on my build and now my amp is eating tubes for lunch?
  
 The tube in question:
  
 (back)

 (front)

  
 Thank you!
  
 -Paul


----------



## JamieMcC

bigfatpaulie said:


> I'm sorry to hijack this thread, but I have a 'noobie toobie' question (groan).
> 
> Pictured below is the 12au7a I received with my Crack.  The glass (from what I remember) was completely clear all around the tube.
> 
> ...


 
  
 Hi Paul
  
 Looks like you received a RCA Clear top. Mine have the same silvering next to the getter which is on the side and not the top like most tubes. Sorry not able to help with info crackling or scratching as am just as new to the Crack as you.
  
 Jamie


----------



## Nic Rhodes

I would clean the pins first on the RCA.


----------



## bigfatpaulie

Thanks, Jamie.  I thought yours looked the same as mine from other images.
  
 Yes, you and I are 'crack brothers' 
	

	
	
		
		

		
			





 
  
 I originally suspected bad solder joint, but because the problem went away with the new tube, I figured it must be the issue.  It's good to know that the tube is supposed to look that way - I was a bit trepidatious to use my new tube.
  
 Thanks, Nic.  I will give cleaning the pins a try later today.  That could be the problem.


----------



## MattTCG

If anyone is looking for a nice NOS 5998, pm me.


----------



## GrindingThud

Has anyone tried using a pair of cracks and using them as balanced monoblocks? +/- into L/R and bridge the output.....will that work on an otl after the output cap?


----------



## NightFlight

skeptic said:


> x2.  To my ears, it's one of the best budget hd800 amps out there in fact.
> 
> If you're looking for an absolute end game setup for hd800's (and that will also handle orthos), mainline is what you want.  It is phenomenal - except for the part where I can't tare myself away from listening at night and wind up sleep deprived and/or with wife aggro.  All in all, a nice problem to have.




Aaaaaaaaaaaarggffhhh.

Fudge.

I had the money all set aside for the mainline. Then I had to buy a new car after someone jumped lane and wrote mine off. The new car is really fun, but I'll be paying it for a few years. No more toys for me... Unless I find a second job. But then no time to listen... 

Just can't catch a break sometimes....


----------



## audiowize

grindingthud said:


> Has anyone tried using a pair of cracks and using them as balanced monoblocks? +/- into L/R and bridge the output.....will that work on an otl after the output cap?


 

 I built such a beast around 2006.  Its performance was nothing short of terrible.


----------



## PTom

There must be a lot of HD600 and HD650 owner here so if you've listened to both on a similar setup, please vote in my HD600 vs HD650 poll:
  
 http://www.head-fi.org/t/698372/the-ultimate-hd600-vs-hd650-poll


----------



## diaBoliQu3

Odac paired with Crack for HD600 should be good enough right?


----------



## GrindingThud

Lol, that makes this an easy project not to do.... Nice looking build though 



audiowize said:


> I built such a beast around 2006.  Its performance was nothing short of terrible.


----------



## MDR30

grindingthud said:


> Has anyone tried using a pair of cracks and using them as balanced monoblocks? +/- into L/R and bridge the output.....will that work on an otl after the output cap?




There are other options for this, including the Audiotailor Jade. The plate/cathode pseudo balanced output is stunning with certain headphones. Will report about it in a week or two. A mark II version of this amp is pending, I believe.

There is something special about OTL amps, as long as you are aware of the importance of high quality caps and chokes.


----------



## JamieMcC

mordicai said:


> Started my Speedball today and need to buy a stronger magnifier.  I feel like I'm a brain surgeon.  The next level in miniaturized electronic's is going to be a blast to build. By the way, I'm 73 with only vision in one eye. If I can do it, you can.


 
  
 I know that feeling and I am 45! and just managed with my old magnifier on the speedball build. The week before Christmas I found a 2.5x magnifying glass with 2 LED lighting modes for £4.99 at my local Lidl store. I  was expecting it to be a cheap plastic affair but was quiet surprised at the quality machined aluminium construction, it has a nice weight to it. It also came with a zipper case and 2AA batteries included and a 5 year warranty . I wonder how they make and ship things like this for the money and why some plastic fantastic products cost so much.
  

  

  

  
 I was so surprised at the quality I googled it and found a little review.
   
http://www.candlepowerforums.com/vb/showthread.php?145561-LIDL-Magnifying-Glass-with-LED-Lighting


----------



## GrindingThud

That is really cool!



jamiemcc said:


> I know that feeling and I am 45! and just managed with my old magnifier on the speedball build. The week before Christmas I found a 2.5x magnifying glass with 2 LED lighting modes for £4.99 at my local Lidl store. I  was expecting it to be a cheap plastic affair but was quiet surprised at the quality machined aluminium construction, it has a nice weight to it. It also came with a zipper case and 2AA batteries included and a 5 year warranty . I wonder how they make and ship things like this for the money and why some plastic fantastic products cost so much.
> 
> 
> 
> ...


----------



## bigfatpaulie

I think I may have a defective tube on my hands...  I cleaned the pins with steel wool and contact cleaner and I still get the same crackling.
  
 More than anything, I want to ensure that my amp isn't frying tubes for some reason 
	

	
	
		
		

		
			





.
  
 Is that a possibility, or am I just crazy?


----------



## audiowize

bigfatpaulie said:


> I think I may have a defective tube on my hands...  I cleaned the pins with steel wool and contact cleaner and I still get the same crackling.
> 
> More than anything, I want to ensure that my amp isn't frying tubes for some reason
> 
> ...


 

 I'd let the amp run for a few days to cook the tubes in a bit.  A very common source of crackling is a flaky solder joint.


----------



## UmustBKidn

bigfatpaulie said:


> I think I may have a defective tube on my hands...  I cleaned the pins with steel wool and contact cleaner and I still get the same crackling.
> 
> More than anything, I want to ensure that my amp isn't frying tubes for some reason
> 
> ...


 
  
 Well, there surely could be something going on with the tube. Odd behavior from a vacuum tube is a sign that the tube is at end-of-life. There is no simple way to describe what could go wrong, because there are lots of ways they can fail.
  
 I would highly suggest trying other tubes. My favorite 12AU7's are d-getter Mullards, but you might spend $100 for one of them on ebay. If you're on a budget and/or just want something else to check it out with, I suggest an old American made tube, particularly the long black plate variety. But honestly, any old American made tube will sound awesome compared to the stuff made today.


----------



## Doc B.

It's not always a sign that tube is at the end of it's life. Tubes that have been in storage can lose a bit of vacuum, and the cathode could need some heating time to reform. Running them for a while can activate the getter and improve the cathode emission. If it's just making a little crackling or rumbling noise it won't hurt anything and it's worth cooking it for a while before you write it off. If it's making loud cracking and arcing over inside it does need to be tossed.


----------



## bigfatpaulie

Interesting...  I tend to leave my amp on...  Too long (I forget 
	

	
	
		
		

		
		
	


	




).  Thank you everyone for the advice.
  
 I cleaned the pins and that *seems* to have fixed the problem.
  
 I really love this amp though.  I ordered a RCA 6AS7G black plate to go with my ECC82 
	

	
	
		
		

		
		
	


	




.  Thanks for a great amp, Doc!


----------



## Dark Helmet

I use the RCA 6AS7G and I love it.  I'm also using a RCA clear top 12AU7 and that seems to be working out well.


----------



## Loquah

dark helmet said:


> I use the RCA 6AS7G and I love it.  I'm also using a RCA clear top 12AU7 and that seems to be working out well.


 
  
 The RCA clear top pairs really nicely with the smoothness of the 6AS7G tubes.


----------



## Loquah

Thought I'd let everyone know that I've just listed my Crack w Speedball for sale 
	

	
	
		
		

		
		
	


	




 and a bunch of tubes too, including the ever popular GEC 6AS7 straight brown base for about $70 less than I could find on eBay!
  
 http://www.head-fi.org/t/698768/melbourne-bottlehead-crack-speedball
  
 http://www.head-fi.org/t/698771/various-6080-and-12au7-tubes-and-equivalents


----------



## audiowize

bigfatpaulie said:


> I think I may have a defective tube on my hands...  I cleaned the pins with steel wool and contact cleaner and I still get the same crackling.
> 
> More than anything, I want to ensure that my amp isn't frying tubes for some reason
> 
> ...


 

 This can also be a funky solder joint.  If you have crackling in both channels, I would start with the power supply.


----------



## bigfatpaulie

loquah said:


> Thought I'd let everyone know that I've just listed my Crack w Speedball for sale
> 
> 
> 
> ...


 
  
 The Mainline is forcing you to retire your Crack?


----------



## bigfatpaulie

audiowize said:


> This can also be a funky solder joint.  If you have crackling in both channels, I would start with the power supply.


 
  
 Thanks.
  
 It's just the right channel.  It is much better now since I cleaned the pins on the tube.  Oddly enough, it still happens when I leave the amp for several hours.


----------



## JamieMcC

Soon to be installing new caps in my Crack.
  
http://www.head-fi.org/t/284863/orgy-of-capacitors-the-cap-thread/360#post_10143998


----------



## Armaegis

bigfatpaulie said:


> The Mainline is forcing you to retire your Crack?


 
  
 At this rate he's probably going to recycle those funds into building their monoblocks...


----------



## Loquah

armaegis said:


> At this rate he's probably going to recycle those funds into building their monoblocks...




LOL. No. While the S.E.X. and Crack are different enough to keep both, the signature and presentation of the Crack and Mainline are very similar so the Mainline renders the Crack redundant in my collection.

That and I really want to sample some other cans with the Mainline.


----------



## PTom

Are any of the Little Dot tube amps at the same level as the BHC with the HD600/HD650?


----------



## MIKELAP

ptom said:


> Are any of the Little Dot tube amps at the same level as the BHC with the HD600/HD650?


 
 Interesting question as i have a Littledot mk3 running 6SL7octals 6DJ8 AND 12AX7 type tubes with adapters and Senns HD800. and  also interested in the BHC amp and how the 2  would compare .


----------



## dxanex

ptom said:


> Are any of the Little Dot tube amps at the same level as the BHC with the HD600/HD650?


 

 Well, I have owned the MK II and MKIII in the past and I can say that while I enjoyed the MKIII's warmth, neither of them had the dead-quiet background or spaciousness of the BHC, at least not with the HD 650. It's been a while, so I can't articulate exact differences, all I can say is I never had the "wow!" moment until I listened to the HD 650 on Crack (even with the stock tubes).
  
 Of course, I was running Amperex tubes in my Little Dots as well. Experiences could differ by rolling other tubes.


----------



## skeptic

jamiemcc said:


> Soon to be installing new caps in my Crack.
> 
> http://www.head-fi.org/t/284863/orgy-of-capacitors-the-cap-thread/360#post_10143998


 
  
 Sexy caps!  Looking forward to your impressions on how they sound once you get some hours on them.


----------



## PTom

dxanex said:


> Well, I have owned the MK II and MKIII in the past and I can say that while I enjoyed the MKIII's warmth, neither of them had the dead-quiet background or spaciousness of the BHC, at least not with the HD 650. It's been a while, so I can't articulate exact differences, all I can say is I never had the "wow!" moment until I listened to the HD 650 on Crack (even with the stock tubes).
> 
> Of course, I was running Amperex tubes in my Little Dots as well. Experiences could differ by rolling other tubes.


 
 Can anyone compare the more expensive Little Dot amps to the BHC?


----------



## JamieMcC

Valab 23 step attenuator musings

 BHC+Speedball+Valab
  
 Instillation
  
 Firstly although this should be a fairly straight forward modification if you are doing this after you have built your Crack + Speedball it requires a bit more work than if you had installed it at the start of your build. Because the valab is quiet tall and the connections are located on its top I had to disconnect and replace all of the connecting wires with longer ones.
  
 This meant un-mounting the small speedball boards (but not disconnecting the wiring) to gain enough access to the octal pins at A7 and A2.  Space is restricted, de-soldering and reattaching longer wires is a fiddly and time consuming task. I was very pleased to have an illuminated magnifying glass to check clearances and solder joints with as the speedball boards make it a bit darker and restrict your angle of view.

 Fitting of the valab 23 step attenuator is quiet straight forward the standard volume pots hole needs to be enlarged by about 1-2mm. The smaller locating pin hole requires elongating slightly a dremel made quick work of these mods.
 I initially thought the Valab would not fit but it did there is only just enough clearance for the Valab and it only fitted because the smaller A/B board can slot between the  small gap between the Valabs upper and lower banks of resistors (see pic).

 Initial impressions with a few hours listening.
  
 Tubes, Mullard 12au7 and Tung-sol 5998

 Most noticeable is an improvement in clarity particularly to the mids and top end.  Music seems to have more of a crispness and openness and to it.

 Placement within the soundstage seems a little more precise. Instruments have a little more attack and bite to the leading edges of notes.

 I can hear some woodiness texture to certain wind instruments I had not noticed before.
  
 Listening as I type to Fleetwood Mac, Lindsey Buckingham’s “I’m so afraid” one of my favourite tracks, is more forceful, darker the bass is tighter and has a touch of presence to it rather than just hearing it.

 My low level volume channel imbalance has gone.

 I was not sure how I would like the volume steps compared to the Cracks standard smooth action pot which I was familiar with in contrast the Valab seemed notchy when trying it before fitting and not very nice at all from a tactile point of operating (I came close to not fitting because of this and had an Alps Blue pot at the ready). This impression improved once fitted and I was adjusting the Valab with the knob fitted.

 I am really pleased with the Valab I have had it in my draw for a while and had been a little daunted as to fitting it because of the amount of de-soldering and rewiring that was required in my case and not wanting to wreck my perfectly working Crack in the process.

 IMHO the Valab has taken my BHC+Speedball +Tung-sol 5998 to a level of refinement above which I had been experiencing when running with the 6AS7G GEC brown base without the Valab fitted. My perception of performance of the GEC is likewise improved.


----------



## networkn

I think I may have damaged my headphone input when soldering and as a result would like to try another to see if I can solve the issues I am having with sound quality.
  
 Due to the fact I am in NZ and Shipping Cost and Time it would take, I thought I'd try and locate a suitable unit locally, but need to know what exactly I need to order?


----------



## JamieMcC

Kia ora, try looking for "phone jack female component"


----------



## Loquah

Great write-up, Jamie!
  
 That sounds like an excellent modification to make. Roughly how much is a Valab attenuator?


----------



## Loquah

networkn said:


> I think I may have damaged my headphone input when soldering and as a result would like to try another to see if I can solve the issues I am having with sound quality.
> 
> Due to the fact I am in NZ and Shipping Cost and Time it would take, I thought I'd try and locate a suitable unit locally, but need to know what exactly I need to order?


 
  
 Pretty sure that this one will do it from Jaycar: http://www.jaycar.co.nz/productView.asp?ID=PS0192&w=6%2E5mm+stereo&form=KEYWORD
  
 The only question is whether the Crack needs a switched one or not. This one isn't switched, but there is an equivalent, switched one for 40c more. I think switching is only required for shorting speaker outputs like on the S.E.X. Here's the link for the switched one though in case you need it: http://www.jaycar.co.nz/productView.asp?ID=PS0190&w=6%2E5mm+stereo&form=KEYWORD


----------



## JamieMcC

loquah said:


> Great write-up, Jamie!
> 
> That sounds like an excellent modification to make. Roughly how much is a Valab attenuator?


 
 Hi Loquah thanks, about AU $28.00 delivery to UK was AU$5 they have been available on ebay from the Vintage Audio Lab shop for some time but it looks like they are updating the shop as they don't have anything listed at the moment and normally there are a fair amount of components listed.
  
http://stores.ebay.co.uk/Vintage-Audio-Lab?_trksid=p2047675.l2563


----------



## Loquah

jamiemcc said:


> Hi Loquah thanks, about AU $28.00 delivery to UK was AU$5 they have been available on ebay from the Vintage Audio Lab shop for some time but it looks like they are updating the shop as they don't have anything listed at the moment and normally there are a fair amount of components listed.
> 
> http://stores.ebay.co.uk/Vintage-Audio-Lab?_trksid=p2047675.l2563


 
  
 Awesome! I might get one for the S.E.X. if it will fit... (which I think it will)


----------



## mcandmar

loquah said:


> Awesome! I might get one for the S.E.X. if it will fit... (which I think it will)


 

 Fits perfectly Loquah, i have some info/pics posted on the BH forum for it


----------



## JamieMcC

I have been listening with the Valab for about 4hrs now and err its just gone 1am here, I am going to have to get some sleep soon, insomnia seems a normal side effect of Crack addiction.
  
 By the way I started listening with the Beyer T1's and in the last hour switched over to the HD650 the improvement in clarity to the top end goes well with the HD650.
  
 Night Night all


----------



## Loquah

Sweet dreams of Crack, Jamie


----------



## networkn

loquah said:


> Pretty sure that this one will do it from Jaycar: http://www.jaycar.co.nz/productView.asp?ID=PS0192&w=6%2E5mm+stereo&form=KEYWORD
> 
> The only question is whether the Crack needs a switched one or not. This one isn't switched, but there is an equivalent, switched one for 40c more. I think switching is only required for shorting speaker outputs like on the S.E.X. Here's the link for the switched one though in case you need it: http://www.jaycar.co.nz/productView.asp?ID=PS0190&w=6%2E5mm+stereo&form=KEYWORD


 
  
 Thanks. So I need a switched on? The one I got was $3.50 from surplustronics, but it doesn't have looped tags which will make it more difficult to solder, and the Nuetrik ones I found that others have recommended only have 3 tags at all, and I couldn't even work out how you would make that work since the wiring diagram needs 6.


----------



## Loquah

I don't know if you need switched. The ones with holes in the lugs are for PCB mounting. You want chassis or surface mount versions like the ones I linked you to.


----------



## UmustBKidn




----------



## JamieMcC

Its been both fun and confidence building adding a couple of mods to my BHC over the last week. Earlier today it was the turn of the JB Capacitors, JFX 100uf 250v premium film caps.  
	

	
	
		
		

		
			





 I still need to add some insulating tape to the cap leads and connecting wires, I will pick some up on Monday I'm a bit to worried about getting my hot air gun to close to use heat shrink sleeving.

 Also on the first pic you can see how the Valab attenuator only just fits inside the case. I had glued some corner braces to the case and needed to remove one of these for the Valab to fit.


----------



## Loquah

Looks great. Can't wait to read your impressions of the cap upgrade.


----------



## JamieMcC

loquah said:


> Looks great. Can't wait to read your impressions of the cap upgrade.


 
  
 Initial impressions are very good, much better than I was expecting which is a pleasant surprise.
  
 I'm planning to let them burn in for 50+hrs or so before committing any thoughts to paper just to see if anything changes during this burning in period.
  
 I also need to spend a bit more time listening, firming my thoughts and impressions of what is happening and more importantly how to put those thoughts down. At the moment I am at a bit of a loss to actually describe in words the effects on presentation I am hearing.


----------



## mcandmar

You could use heatshrink if you heat it with a lighter, that way your quick and precise with the heat being applied. Or alternatively use some PTFE tubing which you can pick up from someone like hificollective.


----------



## MIKELAP

i make adapters for my amp and when  i use heatshrink i use my soldering iron i just rub it against wrap works for me


----------



## kongmw

jamiemcc said:


> I still need to add some insulating tape to the cap leads and connecting wires, I will pick some up on Monday I'm a bit to worried about getting my hot air gun to close to use heat shrink sleeving.


 
  
 ^ beat me to it.


----------



## Nic Rhodes

Jamie, did you get the caps in the UK?


----------



## JamieMcC

Guys thanks for the helpful tips on insulating the cap leads I will give them a try.
  
 Quote:


nic rhodes said:


> Jamie, did you get the caps in the UK?


 
  
 Yes from here with free postage on orders over £40
  
http://www.audiocap.co.uk/


----------



## Nic Rhodes

Thanks, I would be interested in your views when things settle down


----------



## diaBoliQu3

For $200 to $300 DAC, what should I get for my Crack and HD 600. Thinking of ODAC for it's neutrality and give the rest to Crack to color etc... But is there any good DAC, perhaps better than ODAC?


----------



## Dark Helmet

diaboliqu3 said:


> For $200 to $300 DAC, what should I get for my Crack and HD 600. Thinking of ODAC for it's neutrality and give the rest to Crack to color etc... But is there any good DAC, perhaps better than ODAC?




I have the Schiit Modi and I dig it. I would like to try something higher end to hear the difference.


----------



## diaBoliQu3

dark helmet said:


> I have the Schiit Modi and I dig it. I would like to try something higher end to hear the difference.


 
 I'm sorry but what you mean with dig it?


----------



## Dark Helmet

diaboliqu3 said:


> I'm sorry but what you mean with dig it?




I like it. 

I would however, like something thats a little faster (punchier).


----------



## diaBoliQu3

dark helmet said:


> I like it.
> 
> I would however, like something thats a little faster (punchier).


 
 I see... Thanks for clarify that for me. Well, I think I have the similar problem too. A too laid back DAC or amp make listening sound, too... I don't know. I listen to a lot of music but sometime a laid back sound make fast music and vocal sound unsatisfying. Like I wish I was closer to the performance. But a music that in your face type make me feel like I want to go back few row to enjoy the performance.
  
 So what else you have in mind or something you tried?


----------



## Loquah

I think the ODAC would make a really nice pairing with the Crack, but also some other options like the Matrix M-Stage DAC, entry level Audio-gd units, and the Aune T1 are all nice at a good price point. The Aune X1 is really nice too.


----------



## dxanex

diaboliqu3 said:


> I see... Thanks for clarify that for me. Well, I think I have the similar problem too. A too laid back DAC or amp make listening sound, too... I don't know. I listen to a lot of music but sometime a laid back sound make fast music and vocal sound unsatisfying. Like I wish I was closer to the performance. But a music that in your face type make me feel like I want to go back few row to enjoy the performance.
> 
> So what else you have in mind or something you tried?


 

 I've been very happy with my HRT Music Streamer II+ for a long time. _Far_ from laid back, it was a huge step up from my old Music Streamer II. Makes the old MSII sound super tame. I've also heard the Modi and ODAC and neither made me sway my opinion for better or worse. I also find it to be a fantastic match with my BH Crack.


----------



## Armaegis

mikelap said:


> i make adapters for my amp and when  i use heatshrink i use my soldering iron i just rub it against wrap works for me


 

  I try not to do too much rubbing in my crack. A quickie however...


----------



## MIKELAP

armaegis said:


> I try not to do too much rubbing in my crack. A quickie however...


----------



## diaBoliQu3

dxanex said:


> I've been very happy with my HRT Music Streamer II+ for a long time. _Far_ from laid back, it was a huge step up from my old Music Streamer II. Makes the old MSII sound super tame. I've also heard the Modi and ODAC and neither made me sway my opinion for better or worse. I also find it to be a fantastic match with my BH Crack.


 
 What do you think of VDAC 90? Ever tried this DAC?
  


loquah said:


> I think the ODAC would make a really nice pairing with the Crack, but also some other options like the Matrix M-Stage DAC, entry level Audio-gd units, and the Aune T1 are all nice at a good price point. The Aune X1 is really nice too.


 
 Maybe I should try my T1 first with Crack and upgrade if I want more or sound wrong?


----------



## Loquah

diaboliqu3 said:


> Maybe I should try my T1 first with Crack and upgrade if I want more or sound wrong?




Good idea. The T1 is a good DAC for its price so you won't get a lot better without spending more money.


----------



## kongmw

hey guys, quick question. I've had my Crack for a while now but I've always had a slight ringing/microphonics in the left channel if I knock on the chassis/faceplate at regular listening volume w/ no music playing. The ringing is basically drowned out if the music comes on though, so it never really bothered me that much. Just out of curiosity, could this be one of the tubes? I'm running bare stock still with stock tubes. Don't have any spare tubes at the moment but will probably try to swap them out to see if anything happens.


----------



## Loquah

kongmw said:


> hey guys, quick question. I've had my Crack for a while now but I've always had a slight ringing/microphonics in the left channel if I knock on the chassis/faceplate at regular listening volume w/ no music playing. The ringing is basically drowned out if the music comes on though, so it never really bothered me that much. Just out of curiosity, could this be one of the tubes? I'm running bare stock still with stock tubes. Don't have any spare tubes at the moment but will probably try to swap them out to see if anything happens.


 
  
 Microphonics are really normal with tubes, but some are worse than others. The only time it would be an issue is if there is anything else on your desk / bench that can cause vibrations (like my printer does in my office to my Quickie).
  
 Maybe try another tube to see if it's better, but don't worry too much about it as it's very normal.


----------



## kongmw

loquah said:


> Microphonics are really normal with tubes, but some are worse than others. The only time it would be an issue is if there is anything else on your desk / bench that can cause vibrations (like my printer does in my office to my Quickie).
> 
> Maybe try another tube to see if it's better, but don't worry too much about it as it's very normal.


 
 thanks for the quick response. I've lived with it for so long, quite happily I might add. Dunno what got into me today that made me actually ask around. lol 
 back to listening


----------



## skeptic

Doesn't mean you couldn't be even happier if you eliminated the microphonics though! 
  
 You should be able to pick up a decent mil spec 6080 or 2 on ebay for <=$20.  Not as sexy to look at as the curvy glass 6as7g's, but they are generally nice quiet tubes designed to handle some abuse and vibrations.  Search for "jan 6080" - and there are several different lots akin to: http://www.ebay.com/itm/Tube-2ea-6080-RCA-1ea-JAN-6080WB-Sylvania-tstd-amp-radio-amplifier-ham-/390746501948?hash=item5afa4e733c


----------



## kongmw

skeptic said:


> Doesn't mean you couldn't be even happier if you eliminated the microphonics though!
> 
> You should be able to pick up a decent mil spec 6080 or 2 on ebay for <=$20.  Not as sexy to look at as the curvy glass 6as7g's, but they are generally nice quiet tubes designed to handle some abuse and vibrations.  Search for "jan 6080" - and there are several different lots akin to: http://www.ebay.com/itm/Tube-2ea-6080-RCA-1ea-JAN-6080WB-Sylvania-tstd-amp-radio-amplifier-ham-/390746501948?hash=item5afa4e733c


 

 Thanks for the tip! I'll definitely look into it.


----------



## caracara08

With my BHC, I got the free upgraded tubes from BH, anyone remember what type they were and anyone recommend some upgrades for each (without the killing of my wallet)?


----------



## NightFlight

skeptic said:


> Doesn't mean you couldn't be even happier if you eliminated the microphonics though!
> 
> You should be able to pick up a decent mil spec 6080 or 2 on ebay for <=$20.  Not as sexy to look at as the curvy glass 6as7g's, but they are generally nice quiet tubes designed to handle some abuse and vibrations.  Search for "jan 6080" - and there are several different lots akin to: http://www.ebay.com/itm/Tube-2ea-6080-RCA-1ea-JAN-6080WB-Sylvania-tstd-amp-radio-amplifier-ham-/390746501948?hash=item5afa4e733c


 
  
 I don't know. I know some who prefer a slightly microphonic tube. Theory is that it has an ever so slight widening/echoing effect.


----------



## diaBoliQu3

loquah said:


> Good idea. The T1 is a good DAC for its price so you won't get a lot better without spending more money.


 

 T1 adapter faulty.
	

	
	
		
		

		
			




  
 BTW, Cracky progress:


----------



## Loquah

Looks great. What did you do to the chassis plate?


----------



## diaBoliQu3

loquah said:


> Looks great. What did you do to the chassis plate?


 
 Thank you... It's just painted with a can spray. I ask some guy to build for me from A to Z. His initial plan is hammerite black finished for the aluminum plate but seems like the paint not suitable for the aluminum. Black powder coating too expensive, midnight silver spray can very hard to find. So end up with this brown.
  
 BTW, any particular reason why use media monkey player? And why you sell your Crack?


----------



## lljayll

I put together a crack+speedball and I was very happy with the result. Curiosity got the better of me so I got a hold of a wa2. I did serious A/B testing with the two and I'm shocked that the crack is every bit as good as the wa2. For the price of the wa2 I was expecting it to be a big improvement. The crack is amazing no doubt.


----------



## Loquah

diaboliqu3 said:


> Thank you... It's just painted with a can spray. I ask some guy to build for me from A to Z. His initial plan is hammerite black finished for the aluminum plate but seems like the paint not suitable for the aluminum. Black powder coating too expensive, midnight silver spray can very hard to find. So end up with this brown.
> 
> BTW, any particular reason why use media monkey player? And why you sell your Crack?


 
  
 I use MediaMonkey because I find it has the best library management tools. I tried JRiver and Foobar, but MM is just better with its automated library management in my experience.
  
 The only reason I'm selling the Crack is because the Mainline is very similar in its signature and presentation, but also a little better (as you'd expect for the price). I want to free up some funds to buy new cans for now, but I can actually see myself either hanging on to the Crack if I don't get an offer soon or I might sell it now and buy another one later for full custom treatment... we'll see. It's not a reflection on my love for the amp though - it's brilliant.


----------



## palmfish

^ I use Media Monkey too - its so much better than iTunes for managing my music files for my iPods


----------



## PTom

Has anyone here heard of the Megahertz 6080 OTL? Aesthetically at least it looks very similar to the bottlehead crack:
  
 http://www.megahertzaudio.it/otl_con_una_6080.htm
  
The schematics of this amp is on the page. For people familiar with the schematics of the BHC, does the design look similar? It's retailing for around 490 EUR assembled and I hear it's well regarded in Italy, so I'm wondering if it's a good alternative to the BHC for people in Europe.


----------



## Loquah

ptom said:


> Has anyone here heard of the Megahertz 6080 OTL? Aesthetically at least it looks very similar to the bottlehead crack:
> 
> http://www.megahertzaudio.it/otl_con_una_6080.htm
> 
> The schematics of this amp is on the page. For people familiar with the schematics of the BHC, does the design look similar? It's retailing for around 490 EUR assembled and I hear it's well regarded in Italy, so I'm wondering if it's a good alternative to the BHC for people in Europe.




I wish I were better at reading schematics because a lot of that looks extremely similar. Can't wait to hear from others. I hope they haven't copied BH.


----------



## PTom

loquah said:


> I wish I were better at reading schematics because a lot of that looks extremely similar. Can't wait to hear from others. I hope they haven't copied BH.


 
 From the way it looks, my thoughts were that there might have been some influence.


----------



## diaBoliQu3

Guys, I wonder if can mod Crack to balanced output just like FiiO X3 mod their unit:
 http://www.head-fi.org/t/651769/the-fiio-x3-thread/7965#post_10171179


----------



## ben_r_

loquah said:


> I wish I were better at reading schematics because a lot of that looks extremely similar. Can't wait to hear from others. I hope they haven't copied BH.


 

 Nope, its pretty different. But OTL designs are all pretty similar and tube based circuits period are very old and fairly simple, so many of them look very similar.


----------



## Doc B.

It's not a copy of the Crack. It is not a direct coupled circuit, it does not use a constant current source for biasing the first stage. It also uses a different input tube. And of course it does not have the Speedball upgrade available.


----------



## Armaegis

diaboliqu3 said:


> Guys, I wonder if can mod Crack to balanced output just like FiiO X3 mod their unit:
> http://www.head-fi.org/t/651769/the-fiio-x3-thread/7965#post_10171179


 
  
 Not really... but if you really want you can add a 4-pin XLR and connect it with the TRS via... tip = pin1, ring = pin3, sleeve = pin2 AND pin4.


----------



## JamieMcC

Thanks for the tips on insulating my cap leads guys I ended up just stroking the shrink tube with the soldering iron which though not ideal did work. 
  
 After de-soldering & re-soldering the cap leads to put the shrink tube on I was down to my last inch of Cardas quad eutectic solder. I initially brought 3 feet for the Crack build, this turned out to be plenty for the standard Crack + Speedball and I was pleased to have just enough left over to solder in the new cables for the Valab attenuator and add the new film caps.


----------



## Sonido

Anyone else try using the Quickie as a preamp for the Crack? I find it a great synergy especially for the HD800. The Quickie really imparts its signature into the Crack, and sounds distinctly different than Crack by itself. I also added both the Speedball and PJCCS upgrades. The Speedball increased some fine technicalities like details imaging, but I found the PJCCS for the Quickie to really add body and tactility to the bass, giving the HD800 an impact level near that of planar magnetics. This pairing really makes the HD800 a well rounder that sounds great even with rock/pop genres. I'm trying to see if anyone else who's heard this pairing with the HD800 has experienced similar things. For me, the Quickie is a better upgrade than the Speedball for the Crack, at least when using with HD800.


----------



## Loquah

sonido said:


> Anyone else try using the Quickie as a preamp for the Crack? I find it a great synergy especially for the HD800. The Quickie really imparts its signature into the Crack, and sounds distinctly different than Crack by itself. I also added both the Speedball and PJCCS upgrades. The Speedball increased some fine technicalities like details imaging, but I found the PJCCS for the Quickie to really add body and tactility to the bass, giving the HD800 an impact level near that of planar magnetics. This pairing really makes the HD800 a well rounder that sounds great even with rock/pop genres. I'm trying to see if anyone else who's heard this pairing with the HD800 has experienced similar things. For me, the Quickie is a better upgrade than the Speedball for the Crack, at least when using with HD800.


 
  
 Thanks for the tip. I'll try the combo with my T1s.


----------



## Sonido

loquah said:


> Thanks for the tip. I'll try the combo with my T1s.


 

 I like both amps at 9 o'clock volume for the HD800 to optimize S/N and headroom. That's with the PJCCS upgrade. Without, I believe I had the Crack set to 12 o'clock.


----------



## Loquah

You're right, Sonido - that's one heck of a combination. The Quickie somehow adds an almost holographic quality to the sound and seems to open up the soundstage somehow. I really like it a lot!!!!


----------



## Sonido

loquah said:


> You're right, Sonido - that's one heck of a combination. The Quickie somehow adds an almost holographic quality to the sound and seems to open up the soundstage somehow. I really like it a lot!!!!


 

 Good to hear! Glad it's sounding good with other headphones as well. Do you have either Speedball or PJCCS installed?


----------



## Loquah

sonido said:


> Good to hear! Glad it's sounding good with other headphones as well. Do you have either Speedball or PJCCS installed?


 
  
 Yes, both. I was also using the Crack with Mullard ECC82 and GEC 6AS7G tubes


----------



## Sonido

loquah said:


> Yes, both. I was also using the Crack with Mullard ECC82 and GEC 6AS7G tubes


 

 I guess the next logical step for me is tube rolling. How much difference did it make for you vs stock tubes? Was the Speedball or tube rolling a bigger difference? I've pretty much decided on getting a BeePre and Mainline as my endgame for the HD800 since I'm loving this Quickie + Crack combo (Quack?) so much.


----------



## Loquah

sonido said:


> I guess the next logical step for me is tube rolling. How much difference did it make for you vs stock tubes? Was the Speedball or tube rolling a bigger difference? I've pretty much decided on getting a BeePre and Mainline as my endgame for the HD800 since I'm loving this Quickie + Crack combo (Quack?) so much.


 
  
 Speedball is the more significant (and predictable) upgrade. Tube rolling adds the final 5%.
  
 If you're going for the Mainline I'd say save your funds (i.e. don't bother with tubes) and go straight for that. For people who aren't interested in the Mainline, I think some of the affordable tubes out there (5998s, non-GEC 6AS7s, Mullard 6080WA, RCA cleartop 12AU7, Mullard ECC82) can provide excellent improvements from a small investment. Of course the GEC's and some other $100+ tubes are amazing, but not entirely necessary as they are probably only a 1-2% improvement over the good lower priced tubes that I just mentioned.


----------



## Sonido

loquah said:


> Speedball is the more significant (and predictable) upgrade. Tube rolling adds the final 5%.
> 
> If you're going for the Mainline I'd say save your funds (i.e. don't bother with tubes) and go straight for that. For people who aren't interested in the Mainline, I think some of the affordable tubes out there (5998s, non-GEC 6AS7s, Mullard 6080WA, RCA cleartop 12AU7, Mullard ECC82) can provide excellent improvements from a small investment. Of course the GEC's and some other $100+ tubes are amazing, but not entirely necessary as they are probably only a 1-2% improvement over the good lower priced tubes that I just mentioned.


 

 Ok thanks. For me I found adding the stock Quickie to the chain did more than adding the Speedball. Even adding the PJCCS did more than Speedball to the chain. I think this is because the Quickie really imparts its sound signature substantially. I'll probably skip tube rolling in that case, and save up for those amps.


----------



## JamieMcC

As upgrades go for the Crack and if on a tight budget my first choice if building again (which might be soon)  would be to install a Valab 23 step attenuator circa $20 it was a very noticeable improvement for me then onto upgrading tubes. The clarity the Valab brings to the Crack really helped in revealing the individual sonic characteristics of different tubes rolled.


----------



## LogicAudio

jamiemcc said:


> As upgrades go for the Crack and if on a tight budget my first choice if building again (which might be soon)  would be to install a Valab 23 step attenuator circa $20 it was a very noticeable improvement for me then onto upgrading tubes. The clarity the Valab brings to the Crack really helped in revealing the individual sonic characteristics of different tubes rolled.


 

 you'd be better add a small PCB with an optocoupler volume controller (also called light speed attenuator). it comprises some advantegous over regular resistive volume attenuators


----------



## PTom

Do any of the chinese tube amps (Little Dot, Dark Voice, La Figaro etc.) have a similar design/performance as the BHC?


----------



## Lucaswonder

ptom said:


> Do any of the chinese tube amps (Little Dot, Dark Voice, La Figaro etc.) have a similar design/performance as the BHC?


 
 I would like to know too...


----------



## MIKELAP

ptom said:


> Do any of the chinese tube amps (Little Dot, Dark Voice, La Figaro etc.) have a similar design/performance as the BHC?


 
 i run a Littledot MK3 and i also wread  a review of the Littledot and BHC heres the link .About the Littledot if you like to tube roll theres a ton of possibilitys regarding tubes theres the stock EF91-92 and  EF95 types and other types also ,plus if you feel like making adapters you can roll 6DJ8 types 12AX7 and octals .so theres plenty to keep yourself busy with . I use the amp with  Senns HD 800 and i like it .                                                                                                    http://lf.org/abtests/ns/hpamps/10.html


----------



## PTom

Interesting, doesn't sound like he thought there was a huge difference. Not bad considering the LD MK3 is priced at $189 compared to $400 for Crack + Speedball. It would be interesting to know if the more expensive LDs outperform the BHC.


----------



## Lucaswonder

Maybe should buy both and do AB test for yourself


----------



## Lucaswonder

Where can you get LD MK3 for $189? Maybe should buy both and test them out


----------



## PTom

Says $189 on their website:
  
 http://www.littledot.net/forum/viewtopic.php?f=9&t=815&sid=206c698a709a08728fea4acca6b86778
  
 Shipping for either is going to work out similar for me.


----------



## Nic Rhodes

I have a speedball crack and 4se which I roll / DIY 'exotics' in. The BHC is by far the finer amp. The LD has other rolling attributes, not the BHC forte which is sound quality.


----------



## Doc B.

I'm happy to sell you guys whatever you want, but I do wonder why someone would buy $1500 headphones and run them with a $200-300 amp. I would pair HD600s or 650s with Crack, but get a Mainline for HD800s. Horses for courses.


----------



## bigfatpaulie

All I can say is the Crack + Speedball really does work well with the HD800's...


----------



## PTom

Don't get me wrong, I know the BHC is the best in its price range but in my opinion there are still some drawbacks like having to build it (yeah yeah I know a one armed blind man could do it but still there's a question of time, motivation and patience). Getting an assembled OTL with a warranty might be better option for some. Plus outside US there's questions of shipping costs and custom taxes (same for chinese amps I know).
  
 However, I'm surprised that the LDs are not as good as the BHC. I was reading that OTL amps that use 6080 tubes are based on a very old established design (Futterman) and since it's a DIY amp, I assumed it shouldn't be that hard for chinese companies to make something similar at a reasonable price.


----------



## Zashoomin

bigfatpaulie said:


>


 
 I can vouch that the HD800s will run well on the Crack + Speedball but it will run a lot better on a higher end system.  Some of the systems (i am not saying you have to spend your life savings) will really make the HD800s sing.


----------



## Loquah

Agree. Crack is great because it can run HD6x0 / Beyer DTs and even flagships like HD800 and T1 very well, but if you really want to hear your flagship's worth you need to spend a little more on something like the Mainline (or other excellent non-BH amps - i.e. not being biased, just speaking from my personal experiences)


----------



## palmfish

loquah said:


> Agree. Crack is great because it can run HD6x0 / Beyer DTs and even flagships like HD800 and T1 very well, but if you really want to hear your flagship's worth you need to spend a little more on something like the Mainline (or other excellent non-BH amps - i.e. not being biased, just speaking from my personal experiences)




I should point out that I prefer the Crack over the Mainline with my HD 800's. To me, the Mainline sounded more "solid state" although technically, Im sure its the superior performing amplifier.


----------



## Loquah

palmfish said:


> I should point out that I prefer the Crack over the Mainline with my HD 800's. To me, the Mainline sounded more "solid state" although technically, Im sure its the superior performing amplifier.


 
  
 Wow. I agree that the Crack is good, but no combination of tubes (w Speedball) can get it to have the same level of detail and weight / presence as the Mainline. They're in different leagues to my ears (using the T1s)
  
 What is it you prefer about the Crack with the HD800s?


----------



## MIKELAP

doc b. said:


> I'm happy to sell you guys whatever you want, but I do wonder why someone would buy $1500 headphones and run them with a $200-300 amp. I would pair HD600s or 650s with Crack, but get a Mainline for HD800s. Horses for courses.


 
 Usually i use the Senns with my Burson Conductor but i soon discovered that the Littledot MK3 for a $200.00 amp is not bad at all .


----------



## palmfish

loquah said:


> Wow. I agree that the Crack is good, but no combination of tubes (w Speedball) can get it to have the same level of detail and weight / presence as the Mainline. They're in different leagues to my ears (using the T1s)
> 
> What is it you prefer about the Crack with the HD800s?




I prefer the Cracks warmth, weight, and smoothness. It suits the HD 800 well with a lot of my music. When I want detail, I use my Asus Essence One.


----------



## Loquah

palmfish said:


> I prefer the Cracks warmth, weight, and smoothness. It suits the HD 800 well with a lot of my music. When I want detail, I use my Asus Essence One.


 
  
 That's interesting, I find the treble on the Crack slightly edgy compared to the Mainline (and even with my best, smoothest tubes) and I find the weight more realistic on the Mainline, but I would agree that the Crack is warmer overall. I wonder if source has something to do with it. I'm using a Matrix X-Sabre DAC. What are you using?


----------



## palmfish

I have 2 sources feeding the Crack via an Asus Essence One Muses Ed. DAC - a Logitech Squeezebox Touch via coax and a Pioneer SACD player via optical.


----------



## HPiper

I own a LD MKIII and listen to it daily. I recently got to listen to the Crack at the local Seattle show and there is no doubt in my mind that the BHC is by far the better sounding amp. The bass in particular was deeper and better controlled, plus the sound was just cleaner and smoother from bottom to top. Just as a side note and to back up what Bottlehead says about their amps. I also listened to another (unnamed) amp at the same show that costs 3 times as much as the BHC and the BHC was even better sounding than that amp. I think listening via their soon to be released dac might have had something to do with the terrific sound I was hearing but it was nothing short of special in any case. I need to do some serious rearranging of my listening setup to make room for the Bottlehead but I totally am going to get one. In fact that is the only downside, the BHC plus their dac take up quite a lot of room, add my sacd player to that and we are talking a quite large and sturdy table.


----------



## Lucaswonder

mikelap said:


> Usually i use the Senns with my Burson Conductor but i soon discovered that the Littledot MK3 for a $200.00 amp is not bad at all .


 
 Thumbs up! For specific persons, not necessarily more expensive amps are a lot better than cheaper ones! Listen to you ears but not others words! And don't fear to speak out your feelings!


----------



## Loquah

palmfish said:


> I have 2 sources feeding the Crack via an Asus Essence One Muses Ed. DAC - a Logitech Squeezebox Touch via coax and a Pioneer SACD player via optical.


 
  
 Interesting. Do you have the same experience with all 3 sources? (I.e. preferring the Crack)


----------



## palmfish

With every source I have ever heard each amp with, the Crack has come across as the warmer, less detailed, meatier sounding amp to me. The Mainline, on the other hand, is leaner, more detailed and articulate.

In very general terms, what Im saying is that, to me, the Mainline is a more "solid state sounding" amp and the Crack is a more "tubey sounding" amp. Since I already have 2 very fine solid state amps, I prefer the Crack for how different it is.

I hope that explains it better...


----------



## Loquah

palmfish said:


> With every source I have ever heard each amp with, the Crack has come across as the warmer, less detailed, meatier sounding amp to me. The Mainline, on the other hand, is leaner, more detailed and articulate.
> 
> In very general terms, what Im saying is that, to me, the Mainline is a more "solid state sounding" amp and the Crack is a more "tubey sounding" amp. Since I already have 2 very fine solid state amps, I prefer the Crack for how different it is.
> 
> I hope that explains it better...


 
  
 Yes. Perfect explanation - I completely know what you mean now!


----------



## ULUL

palmfish said:


> With every source I have ever heard each amp with, the Crack has come across as the warmer, less detailed, meatier sounding amp to me. The Mainline, on the other hand, is leaner, more detailed and articulate.
> 
> In very general terms, what Im saying is that, to me, the Mainline is a more "solid state sounding" amp and the Crack is a more "tubey sounding" amp. Since I already have 2 very fine solid state amps, I prefer the Crack for how different it is.
> 
> I hope that explains it better...


 
 Superb explanation. In this case, crack is actually what I would be after more than the mainline.  Is your crack upgraded with the speedball?
  
 Thanks,
 UL


----------



## Sonido

I've found for me the Quickie in chain provides far more warmth than Crack alone. The Mainline definitely sounds like something I would want to the technical superiorities, and just preamp it for the warmth. Hopefully, the BeePre has a similar warm signature like the Quickie. Anyone have experience with the BeePre and have compared it to Quickie?


----------



## dguitarnut

Has anyone really botched a Crack build? I have chickened out of building one. 
Surely there is a ready made version of this amp somewhere. I always seem to miss out when folks turn theirs.


----------



## MIKELAP

dguitarnut said:


> Has anyone really botched a Crack build? I have chickened out of building one.
> Surely there is a ready made version of this amp somewhere. I always seem to miss out when folks turn theirs.


 
 http://www.canuckaudiomart.com/details/649102386-bottlehead_crack_with_speedball_upgrade/


----------



## PTom

dguitarnut said:


> Has anyone really botched a Crack build? I have chickened out of building one.
> Surely there is a ready made version of this amp somewhere. I always seem to miss out when folks turn theirs.


 
 I'd make sure it's someone experienced who builds it for you. I think Bottlehead recommends HifiBuilderGuy. For BHC + Speedball I think it'll come to around $800 if he builds it which is basically double the price. I'm sure there must be other experienced builders who'd do it for much less though. 
  
 Anyone know any experienced BHC builders in the UK? I have been approached by experienced American builders who said they'd do the BHC+speedball for $75.


----------



## palmfish

ulul said:


> Superb explanation. In this case, crack is actually what I would be after more than the mainline.  Is your crack upgraded with the speedball?
> 
> Thanks,
> UL


 
  
 No, I don't have the Speedball.


----------



## palmfish

sonido said:


> I've found for me the Quickie in chain provides far more warmth than Crack alone. The Mainline definitely sounds like something I would want to the technical superiorities, and just preamp it for the warmth. Hopefully, the BeePre has a similar warm signature like the Quickie. Anyone have experience with the BeePre and have compared it to Quickie?


 
  
 You know, there is this thing called EQ... lol.


----------



## Sonido

dguitarnut said:


> Has anyone really botched a Crack build? I have chickened out of building one.
> Surely there is a ready made version of this amp somewhere. I always seem to miss out when folks turn theirs.



Prior to the Crack I had less than 10 hours of soldering experience. I built the Crack with Speedball and the Quickie with PJCCS, and each time I didn't even do the voltage or resistance checks because I was too impatient. So far it has all worked on the first try. Knock on wood. I'm very detail oriented when it comes to this though, reading each step over and over again. I think doing that is your best bet on making a working one. I had a friend help me early on during the assembly part of the Crack before and soldering, and I realized he would skimp over details like using wrong screw lengths or wrong positioning of tube sockets. So I guess I'm just very meticulous over the details compared to others, but that has given me only succeed so far.


palmfish said:


> You know, there is this thing called EQ... lol.



The effect comes out to be very different. After all, you can't really EQ the same warmth of a tube amp into a SS amp.


----------



## Loquah

dguitarnut said:


> Has anyone really botched a Crack build? I have chickened out of building one.
> Surely there is a ready made version of this amp somewhere. I always seem to miss out when folks turn theirs.


 
  
 Mine's for sale at the moment in the classifieds. Even at $550 + shipping, I think it'll be cheaper than HiFiBuilder guy if his rate is $800 or so like PTom suggested. Of course I also understand if you don't want it shipped across the world, but thought I'd mention it...


----------



## dguitarnut

Thanks guys I found one because of your help.
 Yeah it amazes me at the number of Audiophiles in Canada and Australia!  Seems like the best stuff is always in one of your countries!


----------



## DutchGFX

Finished mine  I had an issue I forgot to solder from POT to the tube for one channel (doh!) But now it works and sounds fantastic. I stained it black and laquered it, looks pretty good. I'm very pleased, maybe I'll get speedball, or build a B22, can't decide if speedball worth it.

I might sell my soloist, the BHC is much better with the T1. However, the Soloist pairs well with everything I have tried, so I might want to be another high end SS for any orthos or low impedence cans. That's why I'm debating between B22 or just getting speedball. I could build a B22 for $500 so its tough


----------



## PTom

The HD600 vs HD650 poll started over 2 weeks ago is going to close in a little over a day so that we can finally crown a champion once and for all! With over a 100 votes so far, it's still rather close.
  
 If you still haven't voted and you've listened to both of these headphones on a similar setup, vote here:
  
 http://www.head-fi.org/t/698372/the-ultimate-hd600-vs-hd650-poll-final-day-of-voting


----------



## bigfatpaulie

So I took the plunge – I decided to upgrade my Crack…  I bought a pair of Mundorf MKP caps and an Alps Blue Velvet pot.
  
 I hooked it all up, and switched out my tube to my ‘cheapy’ tube for fear that I had hooked everything up wrong.  Anyway, after several hours of listening I was surprised because to me, it made almost no sonic difference…
  
 Then I realized I still had my ‘cheapy’ tubes in my amp.  Woah.  The caps and pot made as much difference as better tubes.   The new caps and pot really upped the detail of the amp.  I’d say it is a worthy upgrade.
  
 I do have a bit of a silly question though, how are people attaching the caps to the main plate?  Mine are sort of dangling there for now, but I would like something a little more secure.  I see a lot of people have those pull ties around the caps, but what are they strapped too on the back side?


----------



## cswann1

bigfatpaulie said:


> I do have a bit of a silly question though, how are people attaching the caps to the main plate?  Mine are sort of dangling there for now, but I would like something a little more secure.  I see a lot of people have those pull ties around the caps, but what are they strapped too on the back side?


 
 I think the most common method to secure a cap via a zip tie to the inside of the case (or anchored to some other support) is with hot glue.


----------



## bigfatpaulie

cswann1 said:


> I think the most common method to secure a cap via a zip tie to the inside of the case (or anchored to some other support) is with hot glue.


 
  
 I read that and said to myself...  "Obviously."
  
 Why the heck didn't I think of that 
	

	
	
		
		

		
			





.
  
 Thank you.


----------



## NightFlight

http://www.head-fi.org/t/284863/orgy-of-capacitors-the-cap-thread/375


----------



## MIKELAP

dguitarnut said:


> Thanks guys I found one because of your help.
> Yeah it amazes me at the number of Audiophiles in Canada and Australia!  Seems like the best stuff is always in one of your countries!


 
 So did you get the one on canuck audio mart especially with your buck these days you probably got a good deal. Good for you .


----------



## JamieMcC

bigfatpaulie said:


> So I took the plunge – I decided to upgrade my Crack…  I bought a pair of Mundorf MKP caps and an Alps Blue Velvet pot.
> 
> I hooked it all up, and switched out my tube to my ‘cheapy’ tube for fear that I had hooked everything up wrong.  Anyway, after several hours of listening I was surprised because to me, it made almost no sonic difference…
> 
> ...


 
  
 Welcome to the cap club Paul 
	

	
	
		
		

		
		
	


	




 I have about 100hrs on the JFX film caps I fitted to my Crack like you a very noticeable improvement in clarity & detailing straight away. They seem to have settled in now, having noticed some further improvement at around 40hrs and then 60hrs marks.


----------



## Zashoomin

dutchgfx said:


> Finished mine
> 
> 
> 
> ...


 
 A beta22 for $500 is doable but its going to have to be very very budget and also it will be very time consuming vs say just installing speedball which can be done in a couple of hours.  Of course the beta will end up being a better all around because it will be able to power orthos as well.


----------



## Loquah

zashoomin said:


> A beta22 for $500 is doable but its going to have to be very very budget and also it will be very time consuming vs say just installing speedball which can be done in a couple of hours.  Of course the beta will end up being a better all around because it will be able to power orthos as well.


 
  
 Or you could buy the S.E.X.


----------



## Zashoomin

loquah said:


> Or you could buy the S.E.X.


 
 The SEX is good...Very good.  But if you can spare to spend enough time on the beta as well as have all the tools and skills needed to build the beta I think that its better.  But for the majority that doesn't meet all 3 of those requirements it will either cost a lot more than a simple 2 channel beta is worth or I would go with the SEX.  Plus the SEX was a lot of fun to build.  
  
 Just my $0.02


----------



## skeptic

bigfatpaulie said:


> I do have a bit of a silly question though, how are people attaching the caps to the main plate?  Mine are sort of dangling there for now, but I would like something a little more secure.  I see a lot of people have those pull ties around the caps, but what are they strapped too on the back side?


 
  
 I'd recommend zip tie mounts, which have adhesive backings but should also ideally be screwed down, because the heat of the amp will likely cause the adhesive to fail over time.
  
 Here's a picture of mine from way back when, after I installed the zip tie mounts, but before I added my speedball or film caps.  I actually measured/placed and stuck down the mounts, then simply drilled straight through them and the chassis plate.  Pretty easy even with a cheap drill, although the adhesive may well gum up and destroy your bit.


----------



## JamieMcC

Paul, I have noticed a few builders have used a bead of bathroom caulk to stick their caps in place. I used the adhesive cable tie bases as I did not want to drill through my top however I am also thinking about adding a small amount of caulk to each end of the caps for a secondary attachment rather than depend solely on the cable tie pads. The caulk ends could then easily be cut with a craft knife for removal if required.


----------



## UmustBKidn




----------



## Armaegis

For you guys worried about adhesive coming off due to heat, why not use an epoxy or crazy glue or something?


----------



## JamieMcC

armaegis said:


> For you guys worried about adhesive coming off due to heat, why not use an epoxy or crazy glue or something?


 
  
 It was more a case of using what is at hand and in the house rather than buying something especially or postpone fitting till the next day when I could have brought some epoxy back from work.
 You are right of course some epoxy or super glue even hot glue would all work well the top plate actually does not get that hot in my experience.


----------



## Armaegis

Well, I probably wouldn't use hotglue... without the speedball especially, the plate near the vent gets quite hot.


----------



## bigfatpaulie

jamiemcc said:


> Welcome to the cap club Paul
> 
> 
> 
> ...


 
  
 Thanks!
  
 I also very appreciate the cap attachment idea!  I've never seen those before but they look like an ideal solution.  
  
 The combo with a Telefunken is just great.  I still need a replacement power tube as the RCA I bought was defective 
	

	
	
		
		

		
		
	


	




.
  
 I am going to go have a look at a hardware store tomorrow.  Thanks everyone, again.


----------



## NightFlight

What size are those mounts? I found a site in canada that sells them, but their around 5-8$ for 100 pack. I don't need a 100... but...


----------



## diaBoliQu3

Guys, what's the dimension for Crack aluminum panel and the bell? Thank you.
  
 And, silver or black better? Or hammerite black? I think black match the bell better. Not sure with hammerite black.


----------



## diaBoliQu3

Ah, nevermind. Found it:

 The base plat is 6" x 10"
 Bell is 2.5" x 3"


----------



## JamieMcC

diaboliqu3 said:


> Guys, what's the dimension for Crack aluminum panel and the bell? Thank you.
> 
> And, silver or black better? Or hammerite black? I think black match the bell better. Not sure with hammerite black.


 
  
 Go with what you like, some of the stone effect spray paints and truck bed liner paints have some interesting looks to them. There are a couple of cracks with the stone effect tops that look smart.


----------



## PTom

I just read the manual for assembling the crack and speedball and I think I'm ready to give it a go. It seems quite straight forwards but there do seem to be a large number of steps but I'm thinking the resistance and voltage check should be very useful in troubleshooting. Anyway I had 2 questions:
  
 1) How long on average do people have to wait to get their BHC from when ordered (I was reading a thread saying some people waited 2 months?).
 2) Do you think it's worth waiting for when they offer a discount, are there any special sales coming up in the US any time soon (equivalent to black friday etc.)?
  
 Thanks.


----------



## Loquah

ptom said:


> I just read the manual for assembling the crack and speedball and I think I'm ready to give it a go. It seems quite straight forwards but there do seem to be a large number of steps but I'm thinking the resistance and voltage check should be very useful in troubleshooting. Anyway I had 2 questions:
> 
> 1) How long on average do people have to wait to get their BHC from when ordered (I was reading a thread saying some people waited 2 months?).
> 2) Do you think it's worth waiting for when they offer a discount, are there any special sales coming up in the US any time soon (equivalent to black friday etc.)?
> ...


 
  
 Timing varies based on the current status of their shipping runs, but I would say 2 months is an anomaly. They normally ship a batch every 3-4 weeks I think with delivery times ranging from 4-6 weeks depending on when in the cycle you order.
  
 Looking at their delivery status page (http://www.bottlehead.com/et/deliverystatus.htm) it seems they're due to ship all the post Christmas orders soon so you'd probably be in the next run I expect, but that's a good reason to get your order in sooner than later.
  
 I can't comment on the sales. It has come up on the website that shall not be named, but who knows if / when that will happen again.
  
 A great option though is to find someone nearby who wants one and buy 2 for a 10% discount.


----------



## Sonido

I got the Crack during a sale where they were offering Speedball for free. Everything was 15% off during Black Friday. In general they have sales, but it's unpredictable.


----------



## PTom

sonido said:


> I got the Crack during a sale where they were *offering Speedball for free*. Everything was 15% off during Black Friday. In general they have sales, but it's unpredictable.


 
 Nice deal!


----------



## ben_r_

ptom said:


> Nice deal!


 

 That WAS an awesome deal. Totally kicked myself for not getting in on that but I had already bought my Crack with Speedball.


----------



## dxanex

Funny, the fastest turn around time I ever had for a Crack/Speedball kit shipped to me was when I got one from "the group site that must not be named".


----------



## PTom

dxanex said:


> Funny, the fastest turn around time I ever had for a Crack/Speedball kit shipped to me was when I got one from "the group site that must not be named".


 
 lol, this is the second time that's been mentioned. Maybe someone could PM me the name of this "Lord Voldemort website".


----------



## diaBoliQu3

jamiemcc said:


> Go with what you like, some of the stone effect spray paints and truck bed liner paints have some interesting looks to them. There are a couple of cracks with the stone effect tops that look smart.


 
 I did search but no result. So far I only found the matte black and it's awesome. Can share the link for hammerite finish?
  
 Stupid of me googling. Should have search in this thread in the first place. *facepalm.


----------



## PTom

ptom said:


> lol, this is the second time that's been mentioned. Maybe someone could PM me the name of this "Lord Voldemort website".


 
 Got it!


----------



## dxanex

diaboliqu3 said:


> I did search but no result. So far I only found the matte black and it's awesome. Can share the link for hammerite finish?
> 
> Stupid of me googling. Should have search in this thread in the first place. *facepalm.


 
  
 I used Rust-oleum matte black for the metal parts on my latest Crack build and it looks pretty boss. But if you use that, make sure you have it laying on top of something soft while you're building the Crack because that stuff scratches if you just look at it wrong. Way easier to scratch than glossy paint. I'd use at least 3 coats of the matte black if you go that route.


----------



## JamieMcC

Ok this has been a lot harder to put down than I first thought but here some impressions on the JFX film capacitors I fitted to my BHCrack.

 BHCrack+Speedball+Valab+JFX film capacitors

 Tubes Tung-Sol 5998 & Mullard 12au7

 Headphones Beyerdynamic Tesla T1

 The instantly most noticeable change to the sound has been clarity and it is really hard to put this into words just how much this has improved it is also a bit mind bending to think it wasn’t so clear before.

 A visualization might be looking out over a scene on a grey day and seeing an area that is bathed in a shaft of sunlight which makes everything sharper, colours pop out and shapes are more clearly defined and focused. Everything within the area of sunlight is just more vivid.

 The perception of sound stage with the T1’s is not much wider than before but it now has greater depth and a smoother and more seamless feel to it.  With the improved clarity I can look deeper into the soundstage and recording to focus on individual instruments within, this placement depth and resolution is very noticeable on live recordings.

 For lack of better words music just flows better, it rises and falls as needed and washes over you with an effortlessness to the dynamics.

 This is really hard to describe but its changed how the T1’s connect me with the music there is no more sense of viewing from say three rows back.

 It feels much more like 'being there' I can be further back viewing a musical in a theatre listening to say Les Miserables taking in the whole scene or next find myself sitting across the table from Melody Gardot or Diana Krall, who are now singing just for me.  On another track I am right on stage right in the middle of the mix with musicians to the left and right and behind enveloped in sound (this really was a first for me and an amazing “Holy Cow I am on the stage” moment, thank you Florence).
  
 This all makes for an increased feel to the atmosphere and venue on live recordings as the music flows out and fills the venues and gives a sense of air as a beautiful solo vocal floats up high into the vaults of a cathedrals ceiling, it’s just beautiful to hear.

 Pretty much all instruments sound better, the distortion of an electric guitar, brushes on drums, the little metal cymbals of a tambourine as they vibrate on both sides when shaken these little details keep coming through, plucks on strings the woodiness of instruments the bounce back on kick-drum or a sense of hollowness to an acoustic guitar or the density of the wood castanets are made of. The transparency of those subtle nuances of tones and textures draw you into the music. To many times just one more track turns into one more album way into the small hours of the morning.

 The capacitors sonics have definitely improved as they burned in. I had a strange intermittent buzz noise in the lower frequencies on some jazz tracks I couldn’t quiet put my finger on what it was. It was just not right I wondered if my headphones had started to develop a problem with reproduction of the frequency. After about 60hrs this buzz has become more defined and developed into a thrum resonance sound from a plucked double bass string.

 The T1’s are a fantastic headphones in many respects but I was very pleased to hear after about 100hrs a welcome hint of soulfulness develop in the midrange and just a little more warmth, body and loveliness to vocals which I think they are the better for.

 The T1’s have scaled well with the addition of the film caps and I continue to be amazed by the reproduction of music I listen to and those out of headphone experiences that catch you by surprise have become much more frequent. I have been very pleased with the results of fitting the film caps.

 I hope some of this makes a little sense.


----------



## KieranO

But new to the whole scene of audiophile territory but VERY interested in a Bottlehead a w/ Speedball (planning on getting hd600 headphone probably, have Akg k550s atm) can anyone advise on price for getting this into the UK? I think someone said on a few pages around £30 for customs, any other fees to think about/currency differences? I've only heard great things about this amp especially combined with the headphones mentioned, thanks in advance for any help!


----------



## JamieMcC

kierano said:


> But new to the whole scene of audiophile territory but VERY interested in a Bottlehead a w/ Speedball (planning on getting hd600 headphone probably, have Akg k550s atm) can anyone advise on price for getting this into the UK? I think someone said on a few pages around £30 for customs, any other fees to think about/currency differences? I've only heard great things about this amp especially combined with the headphones mentioned, thanks in advance for any help!


 
  
 Shipping to the UK (October 2013) worked out at about £45 and the import fees mounted up to about £30 if I remember correctly.


----------



## FlySweep

> Originally Posted by *JamieMcC* /img/forum/go_quote.gif
> 
> 
> 
> ...


 
  
 Great impressions, Jamie.  I haven't had a chance to hear a stock SB'ed Crack (only my custom Crack w/ the Erse Film caps and other mods), but all of what you describe mirrors the feeling I get with my Crack/650 combo.. especially all the talk about hearing minute detail in an effortless, natural manner.

 I'm listening to an album that's practically woven into my childhood.. the Fugees' seminal album, "The Score".. it isn't "audiophile approved" around these parts.. heck it isn't even mixed/mastered all that well (but it's quite serviceable, in that respect).. following along with Lauryn Hill's passionate performance on "Killing Me Softly," the reverb and echo in the recording is so clearly distinguishable.  The production on this album is wonderfully murky, sparse, and atmospheric.. vintage (early) 90's hip hop.. but with the 650/Crack, I hear all sorts of details, transients, and recording effects I've missed in the past.. despite hearing this album too many times to count.


----------



## JamieMcC

flysweep said:


> Great impressions, Jamie.  I haven't had a chance to hear a stock SB'ed Crack (only my custom Crack w/ the Erse Film caps and other mods), but all of what you describe mirrors the feeling I get with my Crack/650 combo.. especially all the talk about hearing minute detail in an effortless, natural manner.
> 
> I'm listening to an album that's practically woven into my childhood.. the Fugees' seminal album, "The Score".. it isn't "audiophile approved" around these parts.. heck it isn't even mixed/mastered all that well (but it's quite serviceable, in that respect).. following along with Lauryn Hill's passionate performance on "Killing Me Softly," the reverb and echo in the recording is so clearly distinguishable.  The production on this album is wonderfully murky, sparse, and atmospheric.. vintage (early) 90's hip hop.. but with the 650/Crack, I hear all sorts of details, transients, and recording effects I've missed in the past.. despite hearing this album too many times to count.


 
  
 Hi Fly Sweep that great that you made some sense of my rambling. It is also interesting that you mention Erse are they the Pulse X Caps by any chance? For some time I have had a sneaky feeling that ERSE’s Pulse X caps and the JB  JFX caps are both the same thing and manufactured by JB Capacitors in China, only branded differently the specs and advertising blurb looks identical for both with just the brands name changed in each case.


----------



## diaBoliQu3

dxanex said:


> I used Rust-oleum matte black for the metal parts on my latest Crack build and it looks pretty boss. But if you use that, make sure you have it laying on top of something soft while you're building the Crack because that stuff scratches if you just look at it wrong. Way easier to scratch than glossy paint. I'd use at least 3 coats of the matte black if you go that route.


 
 Hi... I decided to pick the hammerite finished. I love the stone like finishing. I prefer matte black but they seems so plain. Thinking of redo the wood casing again, adding more layer or paint them to a bit brownish.


----------



## bigfatpaulie

I recently did a similar upgrade as Jamie to my Crack + SB (Mundorf MKP's and Alps Blue Velvet) and I would say his descriptions are very similar that I am hearing. 
  
 I find the upgrade made the amp brighter (probably a poor use of the terminology).  What I mean is that it really opened up the treble and made it cleaner and more separated.  By brighter, I mean that the amp became less dark sounding.  For me, it was a welcome shift in the right direction.  It made the amp sound faster, and more airy. 
  
 Separation was the biggest improvement to my ears.  I have a hard time saying it made the sound stage much bigger, but it helped define it better.
  
 I agree that the Speedball is ultimately the biggest upgrade you can do to the Crack, but the caps do make a very noticeable improvement to the sound.   I originally found the amp a bit slow and too syrupy sounding to match well with the HD800’s and I think this upgrade helped that pairing a great deal.
  
 One thing that I personally still struggle with is the believability of the sound, but I suspect it may be my DAC more than anything.


----------



## JamieMcC

Hi Paul, I tried outputting via my cd player to the BHC and it didn't sound very good at all straight from the cd player. Streaming via my network players dac works much better. Try a different source dvd or blueray if you have one.
  
 By the way a nos e80cc input tube arrived in the post to day I forgot that I had put a bid in on ebay for it until it flagged up for payment. I have tried it with the T1's and found it a bit bright for my liking with them. However with the HD650's its a different story and the E80CC seams to suit them. I don't know if tubes have a burn in period? But will put some hours on it and see what happens.
  
 Edit my quickie also arrived yesterday, but will have to wait for the time being as I am quiet busy with work at the moment.


----------



## bigfatpaulie

jamiemcc said:


> Hi Paul, I tried outputting via my cd player to the BHC and it was not very good at all straight from the cd player. Streaming via my network players dac works much better . Try a different source.
> 
> By the way a nos e80cc input tube arrived in the post to day. I have tried it with the T1's and found it a bit bright for my liking with them. However with the HD650's its a different story and the E80CC seams to suit them. I don't know if tubes have a burn in period? But will put some hours on it and see what happens.


 
  
  
 Yeah, flagships can be fickle!
  
 I running an Audio-GD NFB12.1 (or something like that...  Too many numbers).  I'm currently waiting for Master 7's to be back in stock.  I figure if that doesn't do it, nothing will 
	

	
	
		
		

		
			




  
 I'm running an ECC82 and I really like it.  Very smooth sounding, but still very detailed.  I think tubes have a burning period.


----------



## HPiper

jamiemcc said:


> Hi Paul, I tried outputting via my cd player to the BHC and it didn't sound very good at all straight from the cd player. Streaming via my network players dac works much better. Try a different source dvd or blueray if you have one.
> 
> By the way a nos e80cc input tube arrived in the post to day I forgot that I had put a bid in on ebay for it until it flagged up for payment. I have tried it with the T1's and found it a bit bright for my liking with them. However with the HD650's its a different story and the E80CC seams to suit them. I don't know if tubes have a burn in period? But will put some hours on it and see what happens.
> 
> Edit my quickie also arrived yesterday, but will have to wait for the time being as I am quiet busy with work at the moment.


 

 Yes tubes definitely have a burn in period, about 100hrs will do it with most of them.


----------



## DutchGFX

Can I substitute in a 5U4GB, a 6BL7, a 6SR7GT, a 6SK7GT, or a 6SN7GTB into the power tube slot on my Crack? I was at an antiques store and bought a box of tubes for $40, these all fit, but not sure if they are substitutes.
  
 Also, for the smaller tube (input?)
 Will these fit?
 6R39
 12AT7
 6AU6
 6CB6
 6C4


----------



## bigfatpaulie

dutchgfx said:


> Can I substitute in a 5U4GB, a 6BL7, a 6SR7GT, a 6SK7GT, or a 6SN7GTB into the power tube slot on my Crack? I was at an antiques store and bought a box of tubes for $40, these all fit, but not sure if they are substitutes.
> 
> Also, for the smaller tube (input?)
> Will these fit?
> ...


 
*ROP-IN EQUIVALENTS*

*Input Tubes (Original: 12AU7)*

 12AU7(A)(WA)
 ECC186
 ECC82
 ECC802(S)
 E8025
 E82CC
 CV4003
 CV4122
 CV491
 5814(A)
 6189(W)(WA)
 6680 (WL6680)
 6067
 7489
 7316
 5963 (computer version of 12AU7)

 Sort-of-Drop-In (but not equivalent - for best results, replace plate resistors with Speedball boards)

 E80CC
 12BH7

*Power/Output (Original: 6080)*

 6AS7G
 6080
 6H13C
 5998
 7236
 6N13
  
 I stole that from a great thread on the Bottlehead forum.  It's well worth a read.


----------



## DutchGFX

Ive read that, but these seam to be weird tubes, which is why I don't know if I can use them. Just because they aren't on that list doesn't mean they don't work, know what I mean? Thanks though


----------



## bigfatpaulie

Sorry I couldn't be more help...
  
 I've never heard of the tubes you bought, and I don't know if there is harm in trying them.  Hopefully someone here has an answer.  Or you could ask Doc B.


----------



## ben_r_

bigfatpaulie said:


> *ROP-IN EQUIVALENTS*
> 
> *Input Tubes (Original: 12AU7)*
> 
> ...


 

 Link to the thread?


----------



## audiowize

dutchgfx said:


> Can I substitute in a 5U4GB, a 6BL7, a 6SR7GT, a 6SK7GT, or a 6SN7GTB into the power tube slot on my Crack? I was at an antiques store and bought a box of tubes for $40, these all fit, but not sure if they are substitutes.
> 
> Also, for the smaller tube (input?)
> Will these fit?
> ...


 

 The 6SN7 can function in place of the 12AU7 with an adapter, or with a metal punch and a new socket.
 The amp could also be redesigned for the 6BL7 with some effort.
  
 The rest of the tubes are kind of a hodge podge, thought the 12AT7 is still commonly used in other audio related tube gear.


----------



## bigfatpaulie

ben_r_ said:


> Link to the thread?


 
  
http://www.bottlehead.com/smf/index.php?topic=663.0
  
 (I *think* I am allowed to post it...  If not, sorry mods)


----------



## skeptic

Just following up the above - many of us who have purchased 6sn7 adapters have been badly disappointed by resulting noise issues, so caveat emptor.  I've tried 2 different adapters, and I believe adam tried 3 in his frankencrack, and all of them introduced substantial noise - enough to really make you appreciate how dead quiet the crack is with a 12au7 or 12bh7 up front.  It has been suggested that this can be resolved by creating a battery supply for the 6sn7's heaters (which receive ac from the crack psu), but I haven't seen anyone post confirming that this worked for them.      
  
 For further reference, the folks complaining of noise with 6sn7 adapters all seemed to be hd800 users, so this may or may not be less of an issue with other headphones.


----------



## audiowize

Yeah, you can buy a 6-6.3V DC wall wart (Be sure it's 300+mA), then clip the wires going from B7/B8 to the 9 pin socket, then splice in your adapter to heat the 9 pin tube.  It's also helpful to ground one of those incoming wires as well.


----------



## olegausany

I have matching pair of 6SN7 I bought from eBay and seller claims they are made in 1944-5 and adapter I bought from local member and had no noise problems driving HD700


----------



## UmustBKidn

Here is another thread discussing power tubes:
  
Multi 6080 / 6AS7 review


----------



## JamieMcC

skeptic said:


> Just following up the above - many of us who have purchased 6sn7 adapters have been badly disappointed by resulting noise issues, so caveat emptor.  I've tried 2 different adapters, and I believe adam tried 3 in his frankencrack, and all of them introduced substantial noise - enough to really make you appreciate how dead quiet the crack is with a 12au7 or 12bh7 up front.  It has been suggested that this can be resolved by creating a battery supply for the 6sn7's heaters (which receive ac from the crack psu), but I haven't seen anyone post confirming that this worked for them.
> 
> For further reference, the folks complaining of noise with 6sn7 adapters all seemed to be hd800 users, so this may or may not be less of an issue with other headphones.


 
  
 Thanks skeptic I did not know of noise issues with the 6sn7.


----------



## Shaldome

Got my shipping confirmation last Friday. Now I only have to by some equipment to build it together. I am eager to do this on a weekend.


----------



## Don Lehrer

shaldome said:


> Got my shipping confirmation last Friday. Now I only have to by some equipment to build it together. I am eager to do this on a weekend.


 
  
  
 Good luck! Let us know how it ends


----------



## cswann1

shaldome said:


> Got my shipping confirmation last Friday. Now I only have to by some equipment to build it together. I am eager to do this on a weekend.


 
 When did you place your order?  Are they still backed up?


----------



## lolovitch

cswann1 said:


> When did you place your order?  Are they still backed up?


 
 I also received my shipping confirmation last Friday; ordered on 25th December (Christmas present to myself).
  
 Looking forward to join the club and my first real DIY project!


----------



## Loquah

lolovitch said:


> I also received my shipping confirmation last Friday; ordered on 25th December (Christmas present to myself).
> 
> Looking forward to join the club and my first real DIY project!


 
  
 Congrats to you as well!! You'll love it.
  
@lolovitch and @Shaldome it's worth heading over to the Bottlehead forums if you need any help with your kits. As good as the community here is, there are some real specialists for DIY stuff over there.


----------



## ben_r_

For anyone looking, Frys has the Hakko FX-888D on sale for $70 free shipping. Best deal youll find anywhere on a very nice soldering iron. This is the lowest I ever recommend to anyone serious about soldering. LINK


----------



## brunk

ben_r_ said:


> For anyone looking, Frys has the Hakko FX-888D on sale for $70 free shipping. Best deal youll find anywhere on a very nice soldering iron. This is the lowest I ever recommend to anyone serious about soldering. LINK


 
 I personally recommend this famous Hakko clone for $60 that even comes with a tweezer wand. I actually own 2 of these. They stack right on top of each other nicely too.
  
 http://www.circuitspecialists.com/SMD-soldering-system.html
  
 Plus you can get an assortment of tips off ebay or amazon in a pack of 10 for about $10 that works with it 
  
 http://www.amazon.com/Generic-Solder-Screwdriver-Soldering-Station/dp/B00EB6NJV6


----------



## Shaldome

don lehrer said:


> Good luck! Let us know how it ends



 
 
Thank you, I will do that (if my work is successful that is )


cswann1 said:


> When did you place your order?  Are they still backed up?



 
 
I ordered mine on 27th December.


loquah said:


> Congrats to you as well!! You'll love it.
> 
> @lolovitch and @Shaldome it's worth heading over to the Bottlehead forums if you need any help with your kits. As good as the community here is, there are some real specialists for DIY stuff over there.



 

I will definitely do that, if I run into problems. I still have to gather the parts I need to order, to have everything ready to begin the assembly once the kit arrives. And I still ave to decide, if I finish the wood and top of the Crack. I think I will follow the advice I have read and assemble it without the Speedball upgrade first and do this another time. 
Still a bit bummed, that I missed that my ODAC/AMP has no line out to bypass the amp section, but oh well.


----------



## ULUL

ben_r_ said:


> For anyone looking, Frys has the Hakko FX-888D on sale for $70 free shipping. Best deal youll find anywhere on a very nice soldering iron. This is the lowest I ever recommend to anyone serious about soldering. LINK


 
 Thanks for the tip!  Just ordered. 
  
 Which tip do I need to order for the Bottlehead assembly?
  
 Thanks,
 UL


----------



## UmustBKidn

How would you compare that to this Weller soldering station (also at Fry's)?


----------



## mordicai

Comes with a 1.6 mm which was fine for the crack. I also added small conical tip which was good for some tight places. You will need the conical for the speedball circuit boards which you will surely add to your Crack.


----------



## ben_r_

ulul said:


> Thanks for the tip!  Just ordered.
> 
> Which tip do I need to order for the Bottlehead assembly?
> 
> ...


 

 Yea the tip it comes with should be more than fine.


----------



## JamieMcC

jamiemcc said:


> By the way a nos e80cc input tube arrived in the post to day I forgot that I had put a bid in on ebay for it until it flagged up for payment. I have tried it with the T1's and found it a bit bright for my liking with them. However with the HD650's its a different story and the E80CC seams to suit them. I don't know if tubes have a burn in period? But will put some hours on it and see what happens.


 
  
 Here's a funny thing that nos E80CC tube which I found unbearably bright with my T1's has really mellowed out now and is fast becoming my favourite input tube for both the T1 & HD650's. In fact my much loved Mullard has not been in place since the e80cc arrival!
  
 I am going to have to roll the ECC82 Mullard back in at some point for some critical listening.


----------



## DefQon

E80CC? Are they them tall 12AU7 and half sized tubes? If so think I've had a few in the past they needed like 400 hours of burn in to sound right, that's early 40's NOS for ya.


----------



## FlySweep

defqon said:


> E80CC? Are they them tall 12AU7 and half sized tubes? If so think I've had a few in the past they needed like 400 hours of burn in to sound right, that's early 40's NOS for ya.


 
  
 Yep.. they're the tall bottles.. and yes, they need an assload of time to burn in (IME).


----------



## Nic Rhodes

much later, I thought E80CCs started in 1957....


----------



## DefQon

flysweep said:


> Yep.. they're the tall bottles.. and yes, they need an assload of time to burn in (IME).


 
 Ah guess my memory served me right. They are good tubes though, more linear sounding with more meat than the regular 12AU7's till you hit the big boy's vintage NOS Telefunken ECC82 diamond etch bottom, Valvo and Siemens from 1950-60's NOS, Holland factory Mullards with the flashing top getter. Good thing is the the E80CC are not that expensive too.
  


nic rhodes said:


> much later, I thought E80CCs started in 1957....


 
 Not sure? I got it from a supplier which stated it's from late 1940's forgot the date code and don't have the original box. Bought a carton of 20 or so mixed pairs for cheap so it was awesome to play around with, some of them were shoddy with humming, stored away for nearly half a century.


----------



## mordicai

Been running a Hungarian Trugstam E80cc for the past six weeks. Very bright.  I love it for vocals, but it sure gets rough with the high notes. Its biggest drawback for me is it's real lack of a good bass.  Don't care for it with most of my classical. It probably has 150 hrs on it and hasn't mellowed much in that time. If anyones interested I like to sell it. Fabulous tube with some albums.........Legend ( bob marley) needs a bright tube and this one works great. Do people actually start tube rolling for specific albums? Must wear out the sockets!


----------



## bigfatpaulie

Not to flog a dead horse, but I can't say enough good about the Telefunken (plus, the box is really nice).


----------



## DefQon

bigfatpaulie said:


> Not to flog a dead horse, but I can't say enough good about the Telefunken (plus, the box is really nice).


 
  
 Well they do come at a premium due to there rarity much like GEC brown base 6AS7G's. You can get a Psvane grade A 12AU7 and it is 95% as good as the Telefunken. There's a strong following behind these tubes online at various forums.


----------



## FlySweep

defqon said:


> Ah guess my memory served me right. They are good tubes though, more linear sounding with more meat than the regular 12AU7's till you hit the big boy's vintage NOS Telefunken ECC82 diamond etch bottom, Valvo and Siemens from 1950-60's NOS, Holland factory Mullards with the flashing top getter. Good thing is the the E80CC are not that expensive too.
> 
> Not sure? I got it from a supplier which stated it's from late 1940's forgot the date code and don't have the original box. Bought a carton of 20 or so mixed pairs for cheap so it was awesome to play around with, some of them were shoddy with humming, stored away for nearly half a century.


 
  
 One of my favorite E80CC's is the Amperex PQ 6085.. lovely sound that tube has.. plenty of speed, detail, and dynamics.  Only thing with 12BH7s is, IME, they tend to sound slightly forward through the mids.. not really a drawback, just an observation.
  


mordicai said:


> Been running a Hungarian Trugstam E80cc for the past six weeks. Very bright.  I love it for vocals, but it sure gets rough with the high notes. Its biggest drawback for me is it's real lack of a good bass.  Don't care for it with most of my classical. It probably has 150 hrs on it and hasn't mellowed much in that time. If anyones interested I like to sell it. Fabulous tube with some albums.........Legend ( bob marley) needs a bright tube and this one works great. Do people actually start tube rolling for specific albums? Must wear out the sockets!


 
  
 Interesting I have that tube.. and commented on it a while back (in this thread or another thread somewhere, I think)... and I'm listening with the it right now.  Yeah, it was bright.. for a long time.. I'm talking _months_ (and I used it pretty regularly from when it arrived to when I heard it noticeably change).  Believe it or not, that tube will eventually balance out.. and sound very very good.  It will have really nice bass.  Not the throbbing, subwoofer type.. but a hefty, full, punchy bass response that's natural.  The mids will sound wonderfully detailed and tonally neutral.. but not clinical or thin.  They'll have a hint of that delicious liquidity that its younger 12AU7 brethren has (but the E80CC isn't quite as rich and liquid).  The treble will smooth out too, btw.  Again, it won't ever sound as warm and laid back as it's 12AU7 sibling, but the E80CC is more resolving and better extended.  It'll have a slightly brighter overall tone, but it won't sound as thin, lean or harsh as it might sound now.  Give it more time (a lot more time) if you're up for it.  Also, its one one the best built tubes I've seen... that sucker is rugged!


----------



## DefQon

flysweep said:


> One of my favorite E80CC's is the Amperex PQ 6085.. lovely sound that tube has.. plenty of speed, detail, and dynamics.  Only thing with 12BH7s is, IME, they tend to sound slightly forward through the mids.. not really a drawback, just an observation.


 
  
 You're also forgetting the fact that they are taller but bit slimmer than the 12AU7's, we all love tall tubes right?


----------



## JamieMcC

flysweep said:


> One of my favorite E80CC's is the Amperex PQ 6085.. lovely sound that tube has.. plenty of speed, detail, and dynamics.  Only thing with 12BH7s is, IME, they tend to sound slightly forward through the mids.. not really a drawback, just an observation.
> 
> 
> Interesting I have that tube.. and commented on it a while back (in this thread or another thread somewhere, I think)... and I'm listening with the it right now.  Yeah, it was bright.. for a long time.. I'm talking _months_ (and I used it pretty regularly from when it arrived to when I heard it noticeably change).  Believe it or not, that tube will eventually balance out.. and sound very very good.  It will have really nice bass.  Not the throbbing, subwoofer type.. but a hefty, full, punchy bass response that's natural.  The mids will sound wonderfully detailed and tonally neutral.. but not clinical or thin.  They'll have a hint of that delicious liquidity that its younger 12AU7 brethren has (but the E80CC isn't quite as rich and liquid).  The treble will smooth out too, btw.  Again, it won't ever sound as warm and laid back as it's 12AU7 sibling, but the E80CC is more resolving and better extended.  It'll have a slightly brighter overall tone, but it won't sound as thin, lean or harsh as it might sound now.  Give it more time (a lot more time) if you're up for it.  Also, its one one the best built tubes I've seen... that sucker is rugged!


 
 Nice description and along the same lines as my impressions of Siemens E80CC that I am using.


----------



## mordicai

I don't think I'm up for waiting months to burn this sucker in, even though it has the Bst moods I've heard so far. There must be a way to burn in tubes other then in my Crack.


----------



## Loquah

mordicai said:


> I don't think I'm up for waiting months to burn this sucker in, even though it has the Bst moods I've heard so far. There must be a way to burn in tubes other then in my Crack.


 
  
 Just leave it running when you're not around (but use a cheap 6080 if you don't want to waste the life of a good one)


----------



## mordicai

Its been running about 15 hrs a day for about a month = thats about 450 hrs .I don't believe in this tube now that I have installed Speedball in the Crack. I loved it before that.


----------



## DefQon

No tube requires 450 + hrs of burn in. If it's humming or emitting background hiss/noise its a bad/shorted tube. I also wouldn't recommend burning the amp using any 6080 which put out more heat than regular 6AS7G's. Use a 6AS7G if you need it for this task.


----------



## audiowize

defqon said:


> I also wouldn't recommend burning the amp using any 6080 which put out more heat than regular 6AS7G's. Use a 6AS7G if you need it for this task.


 
 Huh?


----------



## DefQon

6080's put out more heat than 6AS7G's look it up. And another thing I've run into and I think it may apply to the Crack as well is if I use a 6080 in amp X, plate and heater voltage increases as well, put back the 6AS7G and it's back to normal. Odd
  
 http://www.r-type.org/exhib/aaa0725.htm


----------



## mordicai

Huh, Yah me too. This tube has never had any noise of hiss. Amp came with a 6080. What heat are you talking about? Anyway all this E80CC got me ready to go again, so I got the Tungstram out of its box for the 20th time and let it warm up a bit. YOU  WON'T BELIVE THIS......all these weeks that tube had been in its box it has Burned In.....magic! Sure sounds great to me now. Treble seems to have smoothed out, and the bass has improved...What can I tell you.....what a crazy hobby.


----------



## DefQon

mordicai said:


> Huh, Yah me too. This tube has never had any noise of hiss. Amp came with a 6080. What heat are you talking about? Anyway all this E80CC got me ready to go again, so I got the Tungstram out of its box for the 20th time and let it warm up a bit. YOU  WON'T BELIVE THIS......all these weeks that tube had been in its box it has Burned In.....magic! Sure sounds great to me now. Treble seems to have smoothed out, and the bass has improved...What can I tell you.....what a crazy hobby.


 
  
 Yeah my first Crack kit came with a Raytheon 6080 too but the next 4 kits that came to me came with 6AS7's. I'm talking about the tube heat, i.e surface of the tube it get's and run's hotter than the 6AS7G. I measured mine yesterday and 6AS7G's it's running about 75'C with an ambient temperature of 25-26'C. Rolled in the 6080 and boom 98'C, all voltages increased by 20%. Noticed this in every amp I've played with that takes 6AS7G and said sub/equivalents. Not sure what's the problem or it could be my mains is too high feeding more than acceptable into the trafo.


----------



## diaBoliQu3

DACport LX or HRT Music Streamer ii+ or Matrix M-Stage DAC for Crack? I found a 1 year used LX for about $ 175...


----------



## Loquah

defqon said:


> Yeah my first Crack kit came with a Raytheon 6080 too but the next 4 kits that came to me came with 6AS7's. I'm talking about the tube heat, i.e surface of the tube it get's and run's hotter than the 6AS7G. I measured mine yesterday and 6AS7G's it's running about 75'C with an ambient temperature of 25-26'C. Rolled in the 6080 and boom 98'C, all voltages increased by 20%. Noticed this in every amp I've played with that takes 6AS7G and said sub/equivalents. Not sure what's the problem or it could be my mains is too high feeding more than acceptable into the trafo.


 
  
 As far as I know, the Crack was designed to run 6080s so I don't think there is any safety issue with the tube getting hotter. Either way, the point was to use a cheap tube for burning-in if you're not listening at the same time so that you don't lose life from a favourite tube.


----------



## DefQon

loquah said:


> As far as I know, the Crack was designed to run 6080s so I don't think there is any safety issue with the tube getting hotter. Either way, the point was to use a cheap tube for burning-in if you're not listening at the same time so that you don't lose life from a favourite tube.


 
  
 I know but as I said as I've had this issue so far it's best to run something cooler than the hot 6080's. I've always run 6AS7G for anything short of testing to troubleshooting, got a whole stash so why not IME.


----------



## Loquah

defqon said:


> I know but as I said as I've had this issue so far it's best to run something cooler than the hot 6080's. I've always run 6AS7G for anything short of testing to troubleshooting, got a whole stash so why not IME.


 
  
 I'm not being difficult when I ask this:
  
 Why are you concerned about a tube running slightly hotter when it's a well-known, very popular tube that's been in use for many years with no reports of problems and it's being used in a system that's designed specifically for it? I don't understand the concern.


----------



## audiowize

defqon said:


> 6080's put out more heat than 6AS7G's look it up. And another thing I've run into and I think it may apply to the Crack as well is if I use a 6080 in amp X, plate and heater voltage increases as well, put back the 6AS7G and it's back to normal. Odd
> 
> http://www.r-type.org/exhib/aaa0725.htm


 
  
 I'm going to disagree here.  Both draw the same filament current at the same voltage.  In the Crack circuit, both draw the same current from the high voltage supply. 
  
 If the plate/heater voltages go _up_ with a 6080, then the 6AS7 would in fact run hotter. 
  
 In any case, they carry the same ratings and often have the same guts, just in different glass envelopes.


----------



## DefQon

audiowize said:


> I'm going to disagree here.  Both draw the same filament current at the same voltage.  In the Crack circuit, both draw the same current from the high voltage supply.
> 
> If the plate/heater voltages go _up_ with a 6080, then the 6AS7 would in fact run hotter.
> 
> In any case, they carry the same ratings and often have the same guts, just in different glass envelopes.


 
 That's exactly what I had in mind at the very start but upon power up I noticed the 6080 got hotter faster and measuring the different pins shows a large difference almost double. I think it might be a shorted tube unsure at the moment because I've been using this pair of 6080 for every 6AS7 amp (not 6SN7 if I mentioned it typo) to test with. But the odd thing is it sounds fine and I get no arc's upon power up. What's the max voltage for the plate of the 6080? 300volts or something 6as7 is 250v max, there is a regulated cap that feeds pin 5 of the socket rated at 250v when using 6as7's plate voltage is 126v but as soon as the 6080 goes in 276vdc, or is the voltage doubled off the positive lead of the cap feeding back to pin 5 on the socket? Otherwise I'd expect the 250v cap to start smoking since it's 26vdc over it's rating. This is not the Crack btw.


----------



## Doc B.

The envelope of the 6080 is tighter, less surface area than a 6AS7. So the radiated flux will be a little more dense through the envelope, and it has a little less surface area by which to conduct/convect that heat into the environment. The glass will probably measure a little hotter because of this. But the internals are essentially the same and total power radiated into the room by the 6080 will be the same as the heat radiated by the 6AS7 if the tubes are operating at their design spec. P=VI.


----------



## HPiper

doc b. said:


> The envelope of the 6080 is tighter, less surface area than a 6AS7. So the radiated flux will be a little more dense through the envelope, and it has a little less surface area by which to conduct/convect that heat into the environment. The glass will probably measure a little hotter because of this. But the internals are essentially the same and total power radiated into the room by the 6080 will be the same as the heat radiated by the 6AS7 if the tubes are operating at their design spec. P=VI.


 

 Some times you sound almost too smart  No wonder that mainline sounds soooo good!


----------



## DefQon

doc b. said:


> The envelope of the 6080 is tighter, less surface area than a 6AS7. So the radiated flux will be a little more dense through the envelope, and it has a little less surface area by which to conduct/convect that heat into the environment. The glass will probably measure a little hotter because of this. But the internals are essentially the same and total power radiated into the room by the 6080 will be the same as the heat radiated by the 6AS7 if the tubes are operating at their design spec. P=VI.


 
 True but what could you about vdc being almost doubled when measuring the plate pins substituting a 6AS7 for a 6080, unless this Raytheon 6080 is shorted? I'm at lost now even it produces sound, no arcs on power-up.


----------



## bigfatpaulie

I want to share THE GREATEST CRACK MOD.  Ever.
  
 I can't over hype this enough.  It's better than the Speedball, tube rolling or caps/pot upgrade...  Combined.
  
 Now, I think the Crack is great amp, but I always found it to be a bit noisy.  So I started reading about tube amps and interference.  I live downtown Toronto, so there is plenty of radio/electrical noise in my condo.  I read about magnetic chokes, and wire cages.  Then I read about a _different _method of reducing noise...
  
 I moved my amp 3" to the right.
  
 Oh.  
  
 My.  
  
 Gosh.
  
 What a difference.  It's the best upgrade I've ever done to my amp.
  
 I'm floored.
  
 Anyway, I just thought I would share


----------



## DefQon

lol somebody's trippin from the Crack.


----------



## Doc B.

A 6080 should hit the same numbers as a 6AS7 in a Crack amp. If you are having problems with an amp from another manufacturer I suggest you talk to them as we have no clue what the circuit is and can't offer any useful insights because of that.


----------



## audiowize

defqon said:


> True but what could you about vdc being almost doubled when measuring the plate pins substituting a 6AS7 for a 6080, unless this Raytheon 6080 is shorted? I'm at lost now even it produces sound, no arcs on power-up.


 

 Buy 5 6080's and 5 6AS7G's that are tested good.  Perform your experiment several times, draw appropriate conclusions.


----------



## DefQon

Yep leaning towards that need more 6080 got too many 6AS7's.


Is pin 7 heater ground reference and pin 8 6-7vac/dc heater supply?


----------



## audiowize

6V AC or DC needs to be supplied between pins 7 and 8. 
  
 Ground references are up to the designer, and will vary widely depending on other design parameters.


----------



## DefQon

audiowize said:


> 6V AC or DC needs to be supplied between pins 7 and 8.
> 
> Ground references are up to the designer, and will vary widely depending on other design parameters.




So either of the two heater supply pins will be supplying the 6vac/vdc? But not both..


----------



## audiowize

Current requires a loop to flow.  If you have 6V on pin 7, and nothing connected to pin 8, no current will flow though the heaters.
  
 If you measure the voltage between the two pins, it will be 6V AC or 6V DC.


----------



## DefQon

Cheers man got it been working on this amp project for a while finally got it working and sounds nice. The Raytheon 6080 turned out fine had my wiring bit mixed up and the double voltage for the plates I was reporting was VAC using my other fluke DMM. Currently have the amp direct coupled, no cap between the output stages, for the heaters I did trafo to filaments then bridged from pin 7 and 8 to the 6SN7's octal sockets, using one of the pin's as a heater ground reference, 6vac on the heater I might go further regulate it to dc to avoid any hum issues guess it's time to change the schematic, similar fashion to my modded DV 336SE.
  
 Any idea how easy it is to re-wire or even if possible from 6AS7 to 6BQ5's, in this case for the Crack? I really want to put them to use as I have heaps of quads and pairs, quad EL84's are nice as power tubes in another amp I have, these tubes can take lot more voltage abuse and euphonically coloured - in a pleasing way.


----------



## audiowize

defqon said:


> Any idea how easy it is to re-wire or even if possible from 6AS7 to 6BQ5's, in this case for the Crack? I really want to put them to use as I have heaps of quads and pairs, quad EL84's are nice as power tubes in another amp I have, these tubes can take lot more voltage abuse and euphonically coloured - in a pleasing way.


 
 The 6BQ5 doesn't have some of the luxuries available in the 6080 - mainly the +/-300V heater-cathode insulation rating.  Triode strapped, you can get decent transconductance out of a 6BQ5, but you'll need to carefully consider the operating point.


----------



## SNSDluv

Hey guys,

 Someone is offering me this tube. It looks a lot like the GEC straight brown base tube. Can any expert confirm that it is indeed that tube? The owner said that it is from a company CVC but he claims that it is made by GEC and rebranded by CVC. Please let me know as it will be a pretty big investment for me! ><


----------



## DefQon

That is a GEC and yes rebranded by CVC I had an identical one.


----------



## palmfish

It sure looks like a GEC to me...


----------



## SNSDluv

defqon said:


> That is a GEC and yes rebranded by CVC I had an identical one.


 
 So they do sound the same right?


----------



## DefQon

snsdluv said:


> So they do sound the same right?


 
 It's a re-brand not a reissue from a different manufacturing plant (unless specified) so yes they sound the same. GEC's are distinguishable by there brown base which I have not seen any other 6AS7/6080 equivalent manufacturer use.


----------



## SNSDluv

defqon said:


> It's a re-brand not a reissue from a different manufacturing plant (unless specified) so yes they sound the same. GEC's are distinguishable by there brown base which I have not seen any other 6AS7/6080 equivalent manufacturer use.


 

 Thanks so much for the quick response. Last question, I am not sure if it's a fake or real. How do you think about this matter? Is it easy/hard to fake something like this?


----------



## DefQon

snsdluv said:


> Thanks so much for the quick response. Last question, I am not sure if it's a fake or real. How do you think about this matter? Is it easy/hard to fake something like this?


 
  
 No chance of those being fake - at all period. I had the same identical tube bought from a tube supplier locally. First thing if it was a fake it would have unknown and indistinguishable manufacturer(plant)/date codes, second of all it would have a completely different structure of the plates, heaters, getter and grid inside the tube that does not carry the design and characteristic traits of a GEC tube. Sometimes Mullards come close but still different and different sound if you have a pair of GEC's to compare with each other for reference.


----------



## SNSDluv

palmfish said:


> It sure looks like a GEC to me...


 
  


defqon said:


> No chance of those being fake - at all period. I had the same identical tube bought from a tube supplier locally. First thing if it was a fake it would have unknown and indistinguishable manufacturer(plant)/date codes, second of all it would have a completely different structure of the plates, heaters, getter and grid inside the tube that does not carry the design and characteristic traits of a GEC tube. Sometimes Mullards come close but still different and different sound if you have a pair of GEC's to compare with each other for reference.


 
 Thank you two very much for the quick response! YOU AWESOME PEEPS


----------



## SNSDluv

defqon said:


> No chance of those being fake - at all period. I had the same identical tube bought from a tube supplier locally. First thing if it was a fake it would have unknown and indistinguishable manufacturer(plant)/date codes, second of all it would have a completely different structure of the plates, heaters, getter and grid inside the tube that does not carry the design and characteristic traits of a GEC tube. Sometimes Mullards come close but still different and different sound if you have a pair of GEC's to compare with each other for reference.


 

 Another question for you or anyone else will know. Will the GEC Brown base work nicely with Hytron 5814A? I am pairing this with HD700 by the way. Looking for a stronger bass and less treble.


----------



## DefQon

I haven't tried the Hytrons so I don't know.


----------



## Oskari

snsdluv said:


> The owner said that it is from a company CVC but he claims that it is made by GEC and rebranded by CVC.


 
  
 I don't see any evidence of any brand. Is there a CVC label on the tube but invisible in the photos?
  
 The CV type code has no relation to CVC aka Chelmer. It is just the UK government type code for a GEC (or MOV) A1834. 6AS7G is the American type code.
  

http://www.chelmervalve.com/
http://www.tubecollector.org/cv-valves.htm


----------



## punit

I want to buy a 6SN7 to 12AU7  adapter & there are 2 options available : 6.3 V & 12.6 V . Which one do I choose ?
  
 Thanks


----------



## TinFoildHat

Got my shipping confirmation 31st January, ordered Crack+Speedball 12th January, it´s like a late Christmas present 
	

	
	
		
		

		
			





 just have to wait for it to be shipped half way across the world 
	

	
	
		
		

		
		
	


	



 Anyway, when you painted the chassis plate and the bell cover did any of you use primer (paint)?
 I kinda like the hammered finish look, but I have read somewhere that you need a special primer when you paint on aluminium.


----------



## mordicai

That's correct.


----------



## JamieMcC

tinfoildhat said:


> Got my shipping confirmation 31st January, ordered Crack+Speedball 12th January, it´s like a late Christmas present
> 
> 
> 
> ...


 
  
 Congrats hope you have a lot of fun building.
  
 As for the paint generally for alloy a primer or is recommended. However this also depends on what type of paint system you intend to use. Find the spec sheet for your intended paint finish and see if a primer or undercoat is required for alloy it should give you details on what the paint manufacturer recommends for good results.


----------



## JamieMcC

Well I suppose it was inevitable I have had a JFX  2.2uF 250V Polypropylene Film cap that has been sitting in my parts box for a while now (I brought it at the same time as the 100uf films as it only cost £1.72) and ended up soldering it in as film bypass cap across the last electrolytic filter cap in the Crack earlier today.

 I feel there has been a slight improvement in fluidity and presence a touch more body to vocals and also the top end has slightly more crispness to the shimmers and tinkles without importantly for me adding any brightness.

 It now opens up a can of worms with respect to trying something like a PIO or SIO or further bypassing of the current bypassing cap with a smaller Teflon.
  
 I will let the cap burn in for a week or two in situ while I mull over which options to have fun experimenting with next.


----------



## JamieMcC

My Cracks got company!
  
 I wanted a stand to take two cans and ended up making a headphone stand to match my Bottlehead Crack.  It has a Carbon fibre body with solid Oak ends and two tubes running through for keeping the cables tidy. I still need to line the tubes out with a leather or fabric and sand out the hole saw marks on the Oak but you can get the concept.. I have a couple of other ideas I am going to try out also.


----------



## kozmos

What output caps is that?


----------



## bigfatpaulie

Nice stand, Jamie!  Well done!


----------



## JamieMcC

kozmos said:


> What output caps is that?


 
  
 The caps I have been using are the JFX Premium Metallized Polypropylene Films.
  
 Two 100uf 250v for outputs and one 2.2uF 250V across the last electrolytic filter capacitor.
  


bigfatpaulie said:


> Nice stand, Jamie!  Well done!


 
  
 Cheers Paul
  
 How are your new caps settling in?


----------



## ben_r_

jamiemcc said:


> My Cracks got company!
> 
> I wanted a stand to take two cans and ended up making a headphone stand to match my Bottlehead Crack.  It has a Carbon fibre body with solid Oak ends and two tubes running through for keeping the cables tidy. I still need to line the tubes out with a leather or fabric and sand out the hole saw marks on the Oak but you can get the concept.. I have a couple of other ideas I am going to try out also.


 

 Oh man with the CF and the black knob you should have black lacquered the heck out of that wooden base!


----------



## bigfatpaulie

jamiemcc said:


> Cheers Paul
> 
> How are your new caps settling in?


 
  
  
 Very nicely, thanks for asking.  I think they are fully burned in now.  I'm still waiting for my Tung Sol 5998 'Domino Plate' to arrive then I think I will consider my Crack complete.


----------



## DefQon

Lovely JamieMC, I think it was you that confirmed that using CF or 3M vinyl sticker on the metal plate was alright with me 10 pages back in this thread or so despite the heat.
  
 I've got piano black car vinyl stuck on mine at the moment and it's alright I think, of course it scuffs up easily but I can just buy another sticker and put it over again.


----------



## JamieMcC

defqon said:


> Lovely JamieMC, I think it was you that confirmed that using CF or 3M vinyl sticker on the metal plate was alright with me 10 pages back in this thread or so despite the heat.
> 
> I've got piano black car vinyl stuck on mine at the moment and it's alright I think, of course it scuffs up easily but I can just buy another sticker and put it over again.


 
 The 3m car wrap vinyl should have no problem with the heat, it is a quality product.


----------



## MattTCG

Can someone please explain the long wait times for shipping on the Crack kit? 
  
 thanks...


----------



## Armaegis

Bottlehead does not keep a huge stockpile of parts. They order supplies and wait for them just like everyone else.


----------



## MattTCG

See, that makes no sense to me. They have a long wait to  get the kit which is in demand. Why not at least keep enough part to stay current with the demand?


----------



## MIKELAP

matttcg said:


> See, that makes no sense to me. They have a long wait to  get the kit which is in demand. Why not at least keep enough part to stay current with the demand?


 
 +1


----------



## brunk

We can only speculate as to why, but I would imagine it has alot to do with staffing expenses, taxes, and inventory space. You can save alot of money on all three of those reasons doing a big order once a month, instead of operating 24/7 to manage a small amount of orders as they are purchased.


----------



## Nic Rhodes

It is just their business model to keep cost down, whether we like it or not that is how they work. As they have been going for as long as they have it must have merit!


----------



## JamieMcC

matttcg said:


> See, that makes no sense to me. They have a long wait to  get the kit which is in demand. Why not at least keep enough part to stay current with the demand?


 
  
 He waits; that's what he does.

 And I tell you what: tick followed tock followed tick followed tock followed tick...

 Ahab says, 'I don't care who you are, here's to your dream.'

 The old sailors returned to the bar, 'Here's to you, Ahab!'

 And the fat drummer hit the beat with all his heart.

 Here's to waiting.
  
 Good things come to those who wait.
  
http://www.youtube.com/watch?v=Y9znA_dwjHw


----------



## skeptic

Also, just to maintain a little perspective, compare the wait times for Headamp, Eddie Current, or even a pair of Alpha Dogs.  Bottlehead is quite fast by comparison.


----------



## MattTCG

^^ Thank you for this sage advice.


----------



## Doc B.

We've only been doing kits for 20 years and I don't claim to know that much about the business. Nor will I bore you with details of quarterly cost analysis or the challenges of working with multiple small high quality manufacturers to maintain an inventory. There is a saying I have come across that seems to summarize it well:
 Good, inexpensive, fast - you can have two out of three.


----------



## MattTCG

I have owned and operated a small business for the past 15 years. I certainly appreciate the challenges across the spectrum to be successful. I certainly don't mean to come over the wrong way. I also don't expect anyone to be held accountable for the way they run their business on a public forum. 
  
 I just wondered why the wait is so long to get the kit. Are the parts hard to source? Do you have space issues for keeping the inventory? Telling me it's none of my business is a perfectly acceptable answer. I was just curious.


----------



## brunk

matttcg said:


> I have owned and operated a small business for the past 15 years. I certainly appreciate the challenges across the spectrum to be successful. I certainly don't mean to come over the wrong way. I also don't expect anyone to be held accountable for the way they run their business on a public forum.
> 
> I just wondered why the wait is so long to get the kit. Are the parts hard to source? Do you have space issues for keeping the inventory? Telling me it's none of my business is a perfectly acceptable answer. I was just curious.


 
 While I can't speak for Bottlehead, various audio components are very niche parts, which are also run by other small businesses. You are at the mercy of their productions every step of the way. The transformers are most likely requiring a minimum order to fulfill and wait time on top of that. Then you have the acquisition of wood/metal and fabrication time there too. Heck, even the various tubes can be time consuming to acquire since BH gives you NOS and not current-production. That is one thing i appreciate with BH that Woo doesn't do.


----------



## Doc B.

There have been times when we had kits on the shelf. The last time was in about 2010 when the economy was in the crapper. We did maybe 1/3 of the business we do these days, and we are currently seeing a growth rate of about 25%. I have added two employees in the past 18 months, we have increased the order size of some parts as much as tenfold and we just expanded our packing and shipping facility square footage another 30%. We have changed some vendors because the old ones were too slow, like our old laser cutter. And yet even with the continual moves to step up the pace we still find that there times when there are no five lug terminal strips,or Cree rectifiers, or 270 ohm 5 watt resistors (that match the picture in the manual so the builders don't freak out because we sent one that's green and round instead of white and square) on the entire planet, and there won't be any for six weeks. So remember that every time one of you guys says "Why can't Bottlehead keep kits in stock?" I'm saying "Why can't Mouser or McMaster or Solen or DigiKey or Cree or Alpha Wire or Panasonic keep parts in stock?"
  
 I get that this is the age of Amazon (by the way, hey Amazon, I've been waiting a week and a half for the shipping notice for my new modem you said was in stock ready to ship that day) and that we are all impatient. But if I focused entirely upon that aspect of the business we'd probably just end up selling junk*. And I think there's already plenty of competition in that market.
  
 * I was was going to say s**t instead of junk, but my esteemed colleagues have turned that word into one representing very high quality. Go Schiitheads!


----------



## JamieMcC

On that note I have just found and subbed to Jason Stoddard "Schiit Happened" The Story of the World's Most Improbable Start-Up thread  looks like it will be both a interesting and entertaining story and am looking forward to the next instalment.


----------



## MattTCG

doc b. said:


> There have been times when we had kits on the shelf. The last time was in about 2010 when the economy was in the crapper. We did maybe 1/3 of the business we do these days, and we are currently seeing a growth rate of about 25%. I have added two employees in the past 18 months, we have increased the order size of some parts as much as tenfold and we just expanded our packing and shipping facility square footage another 30%. We have changed some vendors because the old ones were too slow, like our old laser cutter. And yet even with the continual moves to step up the pace we still find that there times when there are no five lug terminal strips,or Cree rectifiers, or 270 ohm 5 watt resistors (that match the picture in the manual so the builders don't freak out because we sent one that's green and round instead of white and square) on the entire planet, and there won't be any for six weeks. So remember that every time one of you guys says "Why can't Bottlehead keep kits in stock?" I'm saying "Why can't Mouser or McMaster or Solen or DigiKey or Cree or Alpha Wire or Panasonic keep parts in stock?"
> 
> I get that this is the age of Amazon (by the way, hey Amazon, I've been waiting a week and a half for the shipping notice for my new modem you said was in stock ready to ship that day) and that we are all impatient. But if I focused entirely upon that aspect of the business we'd probably just end up selling junk*. And I think there's already plenty of competition in that market.
> 
> * I was was going to say s**t instead of junk, but my esteemed colleagues have turned that word into one representing very high quality. Go Schiitheads!


 
  
 Thank you for the response and I certainly appreciate your commitment to deliver a quality product as efficiently as possible. I wish everyone at BH continued success. 
  
 After several days on my "loaner" crack, I have found nothing that approaches the sheer sense of enjoyment that the crack is able to flesh out in my hd650's. It's truly a sublime and hypnotic experience. I've owned many hp and many amps. This is the best pairing by a clear and appreciable margin.


----------



## Doc B.

Thanks for the kind words Matt!


----------



## Shaldome

So I picked up my package from customs on Thursday and have the next week off, which should be enough time to build it 
 On my way to the post office to pick up my solder, I will take a visit to a brick&mortar store to get some stain for the aluminum plate and wood base. Maybe I will start painting and finishing the base today to give it some time to dry. I also think I will stick to my plan to build the basic Crack first and install the speed ball upgrade later next week, which is also the suggested approach from Bottlehead, if I remember correctly.
  
 I will report back when I have finished it or ran into problems.


----------



## JamieMcC

Crack bypass update.
  
 Russian Teflon K72P6 (silver one) soldered in place this morning, it is 0.056uf in value. The smaller black capacitor which it is cable tied to is a JFX 2.2uf metalized film!
  
 Phew what a relief nothing sounds any worse and first impressions with the Teflon in the chain are encouraging!  I will let it burn in for a while now.


----------



## grrraymond

Just checking in to repeat that I now listen to music like I did when I was a kid. When my missus goes out, I love nothing more than to pour myself a bourbon, kill the lights and dance around listening to house and pop music. 

I never think of anything that's missing, or if only this, that or the other. Music just sounds brilliant again. The only real downside is that it's kind of killed my audio obsession so I very rarely pop by HF any more. 

Thanks, Doc.


----------



## punit

grrraymond said:


> When my missus goes out, I love nothing more than to pour myself a bourbon, kill the lights and dance around listening to house and pop music.


 
 U must have a really long HP cable 
	

	
	
		
		

		
		
	


	



 Takes one to know one, cos I do the same & I have a 10 ft extension cable.


----------



## Loquah

grrraymond said:


> Just checking in to repeat that I now listen to music like I did when I was a kid. When my missus goes out, I love nothing more than to pour myself a bourbon, kill the lights and dance around listening to house and pop music.
> 
> I never think of anything that's missing, or if only this, that or the other. Music just sounds brilliant again. The only real downside is that it's kind of killed my audio obsession so I very rarely pop by HF any more.
> 
> Thanks, Doc.


 
  
 You must have had very progressive parents, letting you drink bourbon while you danced around listened to music! LOL
  


punit said:


> U must have a really long HP cable
> 
> 
> 
> ...


 
  
 I'm so glad to hear that my old Crack has found itself such a happy home. May it bring you years of enjoyment!!!
  
 Which tubes are you liking best?


----------



## Doc B.

Thanks for the kind words! Nothing makes me more happy than hearing that someone stopped geeking the technical and just soaked up the tunes.


----------



## punit

loquah said:


> I'm so glad to hear that my old Crack has found itself such a happy home. May it bring you years of enjoyment!!!
> Which tubes are you liking best?


 
 My Curent Fav's are the GEC 6AS7G + Mullard ECC82. On a recent Crack high, I got carried away 
	

	
	
		
		

		
			





 & ordered a bunch of tubes from Ebay (listed below). Waiting for them to arrive.
  

 Philips Miniwatt 12AU7 
 Amperex Bugle Boy 12AU7
 Brimar 12AU7 
 Tung-Sol 12AU7 D GTR Black Glass
 GE 12AU7 
 Tung-Sol 12BH7A
 RCA 12AU7
 CBS-Hytron 12au7
  
  
Western Electric 421A 
 GEC 6080WA


----------



## MattTCG

My hardwood walnut crack base is finished. I had to give up on the dovetail corner, but I'm happy with it nonetheless.


----------



## bdr529

Looking good! I don't know if that bottom is temporary, but you will probably want to leave it open underneath so air can flow through.


----------



## JamieMcC

I wood second that, if the base is permanent consider cutting/drilling some vent slots and low level feet so you have some air flow.
  
 Its looking good in walnut.


----------



## MattTCG

I can easily perforate the bottom. I didn't realize that the crack would be drawing air from the bottom. Isn't it designed to sit flat across a table or desk?


----------



## JamieMcC

matttcg said:


> I can easily perforate the bottom. I didn't realize that the crack would be drawing air from the bottom. Isn't it designed to sit flat across a table or desk?


 
  
 I had some small self adhesive feet with my bhc kit which would keep the Cracks case about a pencil thickness clear of what ever it sits on.


----------



## MattTCG

Ok. Thanks Jamie. I'll make some adjustments to the bottom.


----------



## punit

Tried the Western Electric 421A with the Crack today. Just WOW, this is the best sound from the Crack yet, beats the GEC 6AS7G IMHO. Using it with HD 800, The sound is more meaty, mids are more "full" & retains the top end extension & clarity of the GEC. IMHO Its like the best qualities of TS 5998 & GEC 6AS7G combined together


----------



## TinFoildHat

I have to double check on page 19 of the manual says "Attach and solder one end to the power transformer terminal 4. Attach and solder the other end to terminal 2L" But then it says connect it to 14U instead of 22L yield more quiet operation.
 Which is better, 22L or 14U?
 Mine is at the moment connected to 14U.


----------



## Rem0o

matttcg said:


> Ok. Thanks Jamie. I'll make some adjustments to the bottom.


 
 Any type of small feets will do the trick.


----------



## MattTCG

rem0o said:


> Any type of small feets will do the trick.


 
  
 Not in this case. I finished my base with a bottom. So until I remove it or perforate it, the feet won't make any difference.


----------



## JamieMcC

tinfoildhat said:


> I have to double check on page 19 of the manual says "Attach and solder one end to the power transformer terminal 4. Attach and solder the other end to terminal 2L" But then it says connect it to 14U instead of 22L yield more quiet operation.
> Which is better, 22L or 14U?
> Mine is at the moment connected to 14U.


 
  
 I went with 14U and have had no problems.
  
 It did have me racking my brains for a moment when it came to checking my build against the pic on page 36 of the manual as it looked like I had a wire missing! But did not take long to trace back to the revision.


----------



## TinFoildHat

jamiemcc said:


> I went with 14U and have had no problems.
> 
> It did have me racking my brains for a moment when it came to checking my build against the pic on page 36 of the manual as it looked like I had a wire missing! But did not take long to trace back to the revision.


 
 14U it's then  thanks for the quick reply, even though I probably will call it a night now


----------



## Loquah

I used 14U too with great results


----------



## bigfatpaulie

tinfoildhat said:


> I have to double check on page 19 of the manual says "Attach and solder one end to the power transformer terminal 4. Attach and solder the other end to terminal 2L" But then it says connect it to 14U instead of 22L yield more quiet operation.
> Which is better, 22L or 14U?
> Mine is at the moment connected to 14U.


 
  
 I had the same question when I built mine ...  14U is the way to go!


----------



## Solarium

How does the crack compare to Schiit Lyr or Project Ember on a HD650? I'm really sold on the crack's performance but it's huge footprint is just too big for my desk, and I'm looking for similar sounding amps with a smaller and more appealing footprint.


----------



## MattTCG

Short answer, find a place to put the crack. The lyr is a fine amp, no question and does a great job especially with planar magnetic hp's. But when it comes to the hd6x00, get the crack. 
  
 There is not a lot of difference on the footprint between those two amps anyway.


----------



## lokesen

I have just finished this Bottlehead Crack. Default cabinet with three layers of chestnut wood stain, five layers of spar varnish with 400 grit sanding between and a polish of the varnish after a week of hardening. 
  
 The panel has been spray painted with 8 layers of hammered dark grey paint.
  
 I'm going to install the Speedball kit this week, along with two Mundorf 100uf 400v. In a day or two I will post a link to my blog with lots of pictures and detailed description. 
  
 Hope you like it.
  
 Btw. there is a little distortion or maybe sibilance on the highest notes (above 9-10 khz). Is this because the caps aren't burned in yet? It has only been used for 2 hours.


----------



## JamieMcC

lokesen your Crack looks stunning great job. Suddenly I have developed a craving for some rich luxurious chocolate!


----------



## MattTCG

lokesen said:


> I have just finished this Bottlehead Crack. Default cabinet with three layers of chestnut wood stain, five layers of spar varnish with 400 grit sanding between and a polish of the varnish after a week of hardening.
> 
> The panel has been spray painted with 8 layers of hammered dark grey paint.
> 
> ...


 
  
 Great looking build!! Love the dark look.


----------



## palmfish

Yes, very nice looking!


----------



## Ultrainferno

Does anyone have the pdf of the manual/schematic of the Crack? I can't find my printed manual.
 thank you


----------



## Don Lehrer

ultrainferno said:


> Does anyone have the pdf of the manual/schematic of the Crack? I can't find my printed manual.
> thank you


 
 here you go
 http://www.bottlehead.com/et/samplemanuals/Crackmanualsample.pdf


----------



## Solarium

matttcg said:


> Short answer, find a place to put the crack. The lyr is a fine amp, no question and does a great job especially with planar magnetic hp's. But when it comes to the hd6x00, get the crack.
> 
> There is not a lot of difference on the footprint between those two amps anyway.


 
 Why is the Lyr a better amp for planar magnetics? I'm also using the HE-400, so if it pairs great with that as well it's a huge plus for me.


----------



## MattTCG

You don't want the crack for the he400 or any planar magnetic hp. The lyr is the choice is you need an amp that will works across both dynamic driver and planar's.


----------



## Ultrainferno

don lehrer said:


> here you go
> http://www.bottlehead.com/et/samplemanuals/Crackmanualsample.pdf


 
  
 That's just the 5 page sample but thanks, I located it again as well.


----------



## ben_r_

lokesen said:


> I have just finished this Bottlehead Crack. Default cabinet with three layers of chestnut wood stain, five layers of spar varnish with 400 grit sanding between and a polish of the varnish after a week of hardening.
> 
> The panel has been spray painted with 8 layers of hammered dark grey paint.
> 
> ...


 
 Wow, that is the best looking Crack I have ever seen. Well done Sir.
  
 If you were in the US Id probably hit you up to do mine!


----------



## whirlwind

Yes, beautiful...Dark chocolate delicious


----------



## cheneric

lokesen said:


> I have just finished this Bottlehead Crack. Default cabinet with three layers of chestnut wood stain, five layers of spar varnish with 400 grit sanding between and a polish of the varnish after a week of hardening.
> 
> The panel has been spray painted with 8 layers of hammered dark grey paint.
> 
> ...


 
 Holy **** this is beautiful. How much do you think it would cost for me to find someone to do the finish like this for me?


----------



## Loquah

ben_r_ said:


> Wow, that is the best looking Crack I have ever seen. Well done Sir.


 
  
 +1 - beautiful job!


----------



## Ultrainferno

Very nice!


----------



## DefQon

Very nice indeed whats the outer finish? Any lacquer or polished wax or so?


----------



## lokesen

HI. It's just glossy varnish with 400 grit sanding between the layers. After the last coat of varnish is completely hardened, it has been polished with furniture polish.


----------



## MattTCG

lokesen said:


> HI. It's just glossy varnish with 400 grit sanding between the layers. After the last coat of varnish is completely hardened, it has been polished with furniture polish.


 
  
 It's a very nice finish. Great job!!


----------



## JamieMcC

Capacitor Update time.
  
 First off,
  
 Russian Teflon K72P6, used to bypass the 2.2uf film cap which was itself used as a bypass on the last 220uf electrolytic in the Crack power supply.
  

  
 K72P6 Impressions with just over 200hrs on the clock.
  
 I have noticed a slight change in sonics to the top end, it is very subtle but smoother, with what I can only describe as an easiness in its smoothness. Less grain and better resolution but without any hint of the normally associated brightness that I have experience before with such resolution. Its not a wow instantly noticeable sonic signature instead it just blends in as part of the whole picture bringing a touch of refinement. It kind of needs to be listen for specifically in order to get a handle just what has changed. But does come across in the whole.
  
 I would like to say I have no plans to remove the Teflon as I am really loving the sound coming from my Crack at the moment it is absolutely sublime with the T1's and its with some trepidation and no doubt a good dose of stupidity I am going to continue swapping capacitor types and positions in a vain attempt to get a grasp of some of the character the different capacitors types can impart.
  
 Whether or not the changes might improve, on what I currently think could well be perfection for me is yet to be discovered.
  
 ---------------------------------------------------------------------------------------
  
 So my Crack cap rolling odyssey continues.
  
 This time its the turn of a pair of Jantzen z- superior's, experimenting with them used as bypass caps for the JFX 100uf films and later in combinations with some pio film's (polypropylene film in oil, not paper) and some Hybrid mylar, paper and aluminium film in oil variants.
  
 Back to the Jantzen who interestingly state their Z caps require no burn in.
  
 From the Jantzen website
  
 "Superior Cap Even the finest nuances can be heard.The sound never gets over-edged, really superb naturalness with a somewhat bright top-end. Jantzen Audio Superior Z-Caps are absolutely high-end components, delivering a natural, almost holographic sound stage. Even the finest nuances can be heard."
  
 I am pleased to say this is very much inline with my own initial impressions the difference over the JFX alone is instantly quite noticeable. I am wondering if the "somewhat bright top-end" will settle down at all. And while its not " over-edged" it is walking a fine line with T1's and the accentuation of sibilance on some tracks I find just a tad to much for my personal taste. So I hope this might calm down with a little time on the clock.
  
 Everything else is just dandy I particularly like the effect the Jantzen has with the bass it seams more expansive and deeper. There is some really nice ambiance coming through on live recordings
  
 Following on it does suit the HD650's rather well also.


----------



## bigfatpaulie

jamiemcc said:


> Capacitor Update time.
> 
> First off,
> 
> ...


 
  
  
 Holy cow, Jamie!  Nicely done!
  
 You're becoming our resident cap aficionado!


----------



## JamieMcC

bigfatpaulie said:


> Holy cow, Jamie!  Nicely done!
> 
> You're becoming our resident cap aficionado!


 
  
 Aficionado, now that made me chuckle Paul. It is more like standing on the shoulders of the giants over at the Bottlehead forum. But I am learning a whole bunch whilst having a heap of fun.
 The postman kindly dropped off some care packages for me today. Which definitely put a smile on my face 
	

	
	
		
		

		
			





the big box was from Russia just 7 days delivery to the UK and its just so very encouraging to see so much care taken in packaging and makes for great fun unwrapping also.
  

  
 Well wrapped and quick delivery, deserving of a plug if that's allowed.  Thanks ebay seller nixiestore  http://www.ebay.co.uk/usr/nixiestore


----------



## spacequeen7

I don't want to go through all 250+ pages ..what's consider the easiest -best re-cap on this unit that improves sound quality and where i can get socket replacement for 6SN7 ?
 Thank you


----------



## skeptic

Any decent pair of 100uf 250v+ film caps should do. Just be attentive to size if you don't want to have to put your crack on risers. Mundorf mkp, axons, solens, obbligattos, and clarity caps all seem to be relatively popular choices. (I went from axons to obbligattos and prefer the latter.) 

Although not particularly cheap, Parts Connexion is one reasonable option among vendors who sling both boutique caps and tube sockets.


----------



## ben_r_

I bought Axons and Obbligattos from Parts Connexion myself. You dont need to spend anymore than that.


----------



## Loquah

spacequeen7 said:


> I don't want to go through all 250+ pages ..what's consider the easiest -best re-cap on this unit that improves sound quality and where i can get socket replacement for 6SN7 ?
> Thank you


 
  
 You might be best checking over on the Bottlehead Forums (which are currently down due to an upgrade) because this thread is relatively young in cap talk I believe - the people doing it hear have amazing knowledge, but I think there is a greater volume of information over on the Bottlehead Forums.


----------



## JamieMcC

skeptic said:


> Any decent pair of 100uf 250v+ film caps should do. Just be attentive to size if you don't want to have to put your crack on risers.


 
  
 +1 any of the mainstream audiophile film caps should bring a noticeable improvement in sonics over the stock electrolytic capacitors.
 I have been very happy with the price performance ratio of JFX premium films.
  
 Headfi  has the orgy of capacitor thread only 28 pages and has some helpful info.
  
http://www.head-fi.org/t/284863/orgy-of-capacitors-the-cap-thread/405#post_10283906
  
 The Capacitor Porn thread on the bottlehead forum is also full of info (when back online).


----------



## grrraymond

Well, despite my 'complete satisfaction', I saw a cheap Mullard ECC82 on eBay and it arrived yesterday, my first upgrade from stock Crack and I was surprised that tube rolling has an effect, even at that price (tenner or so). I definitely prefer it to the stock tube, just a little tighter in the bass but also the top end has opened up, separation is better with drum sounds. Something like Contact off the recent Daft Punk album sounds like your head is taking off, makes me sit up straight. Thank God I've only seen the 5998s available in pairs, that should put me off for another six months or so.


----------



## Loquah

grrraymond said:


> Well, despite my 'complete satisfaction', I saw a cheap Mullard ECC82 on eBay and it arrived yesterday, my first upgrade from stock Crack and I was surprised that tube rolling has an effect, even at that price (tenner or so). I definitely prefer it to the stock tube, just a little tighter in the bass but also the top end has opened up, separation is better with drum sounds. Something like Contact off the recent Daft Punk album sounds like your head is taking off, makes me sit up straight. Thank God I've only seen the 5998s available in pairs, that should put me off for another six months or so.


 
  
 I love the Mullard ECC82s. They and the RCA Cleartops are the best bargains in all of tubedom I think.


----------



## JamieMcC

grrraymond said:


> Well, despite my 'complete satisfaction', I saw a cheap Mullard ECC82 on eBay and it arrived yesterday, my first upgrade from stock Crack and I was surprised that tube rolling has an effect, even at that price (tenner or so). I definitely prefer it to the stock tube, just a little tighter in the bass but also the top end has opened up, separation is better with drum sounds. Something like Contact off the recent Daft Punk album sounds like your head is taking off, makes me sit up straight. Thank God I've only seen the 5998s available in pairs, that should put me off for another six months or so.


 
  
 I find the Mullard 6080 is also a nice sounding tube and pairs well with the RCA Cleartop mentioned.


----------



## Loquah

jamiemcc said:


> I find the Mullard 6080 is also a nice sounding tube also and pairs well with the RCA Cleartop mentioned.


 
  
 Agree. The Mullard 6080WA and the Mullard ECC82 are an awesome combo with brighter headphones, but the 6080WA needs the top end of the Cleartop with neutral-to-warm headphones.


----------



## punit

loquah said:


> Agree. The Mullard 6080WA and the Mullard ECC82 are an awesome combo with brighter headphones, but the 6080WA needs the top end of the Cleartop with neutral-to-warm headphones.


 

 After getting the BHC from you I have ordered around 6 6AS7 / 6080  & around 9 12AU7 tube variants. I sit with the BHC in the night swapping various combination of tubes & taking notes in my notepad about the SQ of each tube combination. It is so addictive, my wife thinks I am going crazy


----------



## Loquah

punit said:


> After getting the BHC from you I have ordered around 6 6AS7 / 6080  & around 9 12AU7 tube variants. I sit with the BHC in the night swapping various combination of tubes & taking notes in my notepad about the SQ of each tube combination. It is so addictive, my wife thinks I am going crazy


 
  
 LOL. Please apologise to your wife for me.
  
 I completely understand what you mean. I had a really hard time letting go of some of my cheaper tubes even after I had no amp to use them in. I wanted to keep them just in case I ever bought another Crack!


----------



## UmustBKidn

loquah said:


> LOL. Please apologise to your wife for me.
> 
> I completely understand what you mean. I had a really hard time letting go of some of my cheaper tubes even after I had no amp to use them in. I wanted to keep them just in case I ever bought another Crack!


 
  
 If you think that's bad, I'm already collecting a series of power tubes for the Crack, and I don't own one yet. I already own two Tung-Sol 5998's, several 6080's, and a few dozen 12AU7's. In my defense, I'm using the preamp tubes for my Bravo V2's. So it's not totally without purpose.
  
 I think I am going to put in for a week's vacation when I finally do order and put together my kit. I'll need it, just for tube rolling


----------



## MIKELAP

loquah said:


> LOL. Please apologise to your wife for me.
> 
> I completely understand what you mean. I had a really hard time letting go of some of my cheaper tubes even after I had no amp to use them in. I wanted to keep them just in case I ever bought another Crack!


 
 I can understand the tube rolling thing you might say , my wife also stopped asking me why i have so many tubes close to 200 most of them i dont listen to as they are spares or i have found better sounding ones i guess at one point its listening to them and also collecting them . whats nice about them is the mechanical part of it , to look at how there made thats appealing and also the age of these things .What fun.


----------



## spacequeen7

umustbkidn said:


> If you think that's bad, I'm already collecting a series of power tubes for the Crack, *and I don't own one yet*. I already own two Tung-Sol 5998's, several 6080's, and a few dozen 12AU7's. In my defense, I'm using the preamp tubes for my Bravo V2's. So it's not totally without purpose.
> 
> I think I am going to put in for a week's vacation when I finally do order and put together my kit. I'll need it, just for tube rolling


 
 I like your style


----------



## mordicai

I'm ready to stop buying tubes and start selling. I'm happy with my Tung-sol 5998 with either my Ken-Rad 5188 (1948) or my Phillips Mini-watt E80CC. Going to sell my duplicates and all the rest and concentrate on buying music instead.


----------



## spacequeen7

can someone post a list of all compatible tubes we can use on Crack ?


----------



## Sonido

I think it's excessive if you reach a point when you've spent enough on tubes or caps where you could have afforded the Mainline instead. I doubt upgrades could get you to the level of the Mainline.


----------



## Armaegis

spacequeen7 said:


> can someone post a list of all compatible tubes we can use on Crack ?


 
  
 The bottlehead forum has a listing of tubes, although they are currently down for upgrades/maintenance so you'll have to wait a couple days.


----------



## JamieMcC

Hopefully Doc will drop in and let us know when the new Bottlehead site is up and running.


----------



## bigfatpaulie

I recently picked up a Tung-Sol 5998 and with it I sometimes hear a rustling sound in one channel.  I've since cleaned the pins, and I don't experience this with any other tube...  Is there anything else I can try to fix this?  Is this just a bad tube or..?
  
 I had a 6AS7G that I got off the bay not too long ago that hummed, now this...  I have been so unlucky with power tubes


----------



## Doc B.

We have been on the web so long that our old server setup is kind of like going into a hoarder's basement. We're finding stuff in there we didn't even know we had, that is creating some issues with the site migration  There is a team working hard today to shake out a last few odd glitches get us active on our new cloud host. Hope to have the new look up today. Keep your fingers crossed for us - unless you are holding a soldering iron.


----------



## JamieMcC

doc b. said:


> We have been on the web so long that our old server setup is kind of like going into a hoarder's basement. We're finding stuff in there we didn't even know we had, that is creating some issues with the site migration  There is a team working hard today to shake out a last few odd glitches get us active on our new cloud host. Hope to have the new look up today. Keep your fingers crossed for us - unless you are holding a soldering iron.


 
  
 I had my soldering iron out on the Crack today.
  
 I also got the camera out  to try and get a shot of the tubes glowing, well why not I am not the only one!  Anyhow as normal with such things it turns out to be harder than it looks. I think steadier hands or a tripod would help and I could also have straightened up the input tube which I did not realise was a little wonky.  Next time (if there is one).


----------



## MattTCG

Looking forward to the site being back up. I have many questions and information that I need to seek out.


----------



## Loquah

jamiemcc said:


> I had my soldering iron out on the Crack today.
> 
> I also got the camera out  to try and get a shot of the tubes glowing, well why not I am not the only one!  Anyhow as normal with such things it turns out to be harder than it looks. I think steadier hands or a tripod would help and I could also have straightened up the input tube which I did not realise was a little wonky.  Next time (if there is one).


 
  
 I love the blue glow in the input tube! And yes, a tripod is a must for this kind of shot...


----------



## Doc B.

One can always call us at 206-451-4275 M-F from 10-6PT or contact me by PM.


----------



## MattTCG

^^ Thanks Doc...any idea when the next round of kits will be shipping. I put in an order around  the 24th of January.


----------



## Doc B.

I'm afraid the shipping crew has gone home for the evening, but I will check with them tomorrow morning.


----------



## MattTCG

No problem. Thanks for the reply...


----------



## punit

sonido said:


> I think it's excessive if you reach a point when you've spent enough on tubes or caps where you could have afforded the Mainline instead. I doubt upgrades could get you to the level of the Mainline.


 

 Crack addicts are not rational people


----------



## brunk

punit said:


> Crack addicts are not rational people


 
 Hehe so true. I have been trying to find an excuse to use mine lol. Definitely not selling it though!


----------



## Loquah

Haha. Mine was sitting idle so I sold it to punit. I miss it regularly, but don't regret the decision as it's now being used and loved rather than sitting idle.


----------



## Doc B.

As requested I am happy to announce that our forum is back up and we have a new look on our website. If you still see the old site, try again in a while, as it takes some time for it to propagate. 

Re shipping, Crack kits should be shipping again next week.


----------



## skeptic

Congrats Doc! The new site looks great and load times are super fast!


----------



## bigfatpaulie

doc b. said:


> As requested I am happy to announce that our forum is back up and we have a new look on our website. If you still see the old site, try again in a while, as it takes some time for it to propagate.
> 
> Re shipping, Crack kits should be shipping again next week.


 
  
 Nicely done!  I think it looks great!  Thank you for investing in upgrading the site to benefit your end users.


----------



## JamieMcC

doc b. said:


> As requested I am happy to announce that our forum is back up and we have a new look on our website. If you still see the old site, try again in a while, as it takes some time for it to propagate.
> 
> Re shipping, Crack kits should be shipping again next week.


 
  
 Super news


----------



## DefQon

lokesen said:


> HI. It's just glossy varnish with 400 grit sanding between the layers. After the last coat of varnish is completely hardened, it has been polished with furniture polish.


 
  
 It's like sex on fire.


----------



## MattTCG

The new site looks wonderful. 
	

	
	
		
		

		
		
	


	




 
  
 But...I'm not getting images that are posted though.


----------



## spacequeen7

I don't know what I'm doing wrong ,I'm stuck here


----------



## JamieMcC

matttcg said:


> The new site looks wonderful.
> 
> 
> 
> ...


 
 Matt are you still able to on?  I took a look about an hour ago and noticed the same pic bug went to leave a bug report as pics linked via urls work ok but those attached with the little paper clip symbol did not how as normal. When I pushed the submit button it went back to the admin maintenance page and I have been unable to log in since.


----------



## MattTCG

^^ Yes, I'm still on. Looks like they have some bugs to work out, which is to be expected in a transition like this.


----------



## JamieMcC

matttcg said:


> ^^ Yes, I'm still on. Looks like they have some bugs to work out, which is to be expected in a transition like this.


 
  
 Can you try a copy and past of the forum url here so I can see if the forum will load via a link?


----------



## MattTCG

http://bottlehead.com/smf/index.php
  
 hope that this is not against the rules here.


----------



## JamieMcC

Matt, no joy with the link my end, thanks forgiving it a go.


----------



## MattTCG

I will never close that page...might not get back in.


----------



## whirlwind

Link allows me in.


----------



## JamieMcC

Just tried again with no joy, I just get the Maintenance Mode page, how strange. Will try on my other pc in case its pc related.


----------



## Doc B.

When a domain moves as outs just did it takes up to 24 hours for it to propagate throughout the internet. Going from a dedicated server to cloud based makes the process a bit more complex as various parts of the site are now on various servers. My suggestion is just try again in a while. Re the images, we are aware of the issue. I have a thread started about the new website, where you guys can post bug reports so you don't have to use the bandwidth on Head Fi. Things like the images and other glitches will probably start to get fixed Monday, as the web design team needs a few well deserved days off.


----------



## brunk

I am able to get inside and the new website looks fantastic! I am a fan of the grey/orange layout as it's pretty well known that reduces eye fatigue and improves legibility.
  
 Cheers Doc!


----------



## Armaegis

Some people might still be having cache issues. Try holding Ctrl or Shift before hitting the refresh button (or pressing F5).


----------



## MattTCG

edit..


----------



## ben_r_

'Bout dang time Doc! New site looks great!


----------



## JamieMcC

Short update on the Jantzen Superior Z
  
 I am glad I gave the Jantzens some time to burn in they have defiantly improved. The very annoying sibilance that was initial prevalent (testing with my most prevalent recordings for it)has noticeably diminish.
  
 The sound continued to improve across the spectrum and with it a shift in the equilibrium appearing with the balance between liquidity and authority. The Jantzen signature is more dominant and overriding.  Super Resolution and fast transients spacious stage override.
  
 Resolution, on some uber fast Spanish guitar pieces is astonishing not only able to hear notes as normal but also the attack of the plectrum hitting the strings on each strum behind the notes quiet amazing considering the speed.
  
 With further listening and burn this combination for me has swung to far to the clinical side with its authority and dominance at the expense of musicality.
 The softness and naturalness of texture in timbre and tones which beguiled is being drowned out.  I removed the Jantzens from this combination so I could re-reference the sound. I will try them again later with some pio caps and see if it’s a more pleasing combination. The Jantzens are certainly very good caps and I think many would like what they bring to the table.
  
 A couple of progress pics.


----------



## spacequeen7

wow ..you taking this to another level ,it looks crazy...


> spectrum and with it a shift in the equilibrium appearing with the balance between liquidity and authority


 
   my head is spinning 
	

	
	
		
		

		
		
	


	




 
  
 P.S. I just received my pre-build (with speedball upgrade) unit today and was wondering  if I could use any of this tubes (sorry I just can't get on the Bottlehead Forum)


> 6922*
> 7308*
> 6AQ8*
> 6BK7*
> ...


----------



## Loquah

jamiemcc said:


> Short update on the Jantzen Superior Z
> 
> I am glad I gave the Jantzens some time to burn in they have defiantly improved. The very annoying sibilance that was initial prevalent (testing with my most prevalent recordings for it)has noticeably diminish.
> 
> ...


 
  
 Brilliant write-up Jamie!


----------



## JamieMcC

spacequeen7 said:


> wow ..you taking this to another level ,it looks crazy...
> my head is spinning
> 
> 
> ...


 
  
 Hi here is the list you are after from the Bottlehead Forum. Enjoy your build its a great sounding amp as you will soon find out!
 I am just having fun experimenting rolling caps instead of tubes, I doubt there is much difference in cost at the end of the day.Those silver and green ones are about the same price as a cup of coffee each and are Russian military surplus.
  
  *DROP-IN EQUIVALENTS

 Input Tubes (Original: 12AU7)*

 12AU7(A)(WA)
 ECC186
 ECC82
 ECC802(S)
 E8025
 E82CC
 CV4003
 CV4122
 CV491
 5814(A)
 6189(W)(WA)
 6680 (WL6680)
 6067
 7489
 7316
 5963 (computer version of 12AU7)

 Sort-of-Drop-In (but not equivalent - for best results, replace plate resistors with Speedball boards)

 E80CC
 12BH7
  


loquah said:


> Brilliant write-up Jamie!


 
  
 Lachlan cheers
	

	
	
		
		

		
		
	


	




 I am loving this latest combination, going to run them in for week of two now.
  
 There is a teaser of sorts on the orgy of caps bb in my quote of Jon L
  
  http://www.head-fi.org/t/284863/orgy-of-capacitors-the-cap-thread/405#post_10298191


----------



## uelover

I have just ordered the crack + speedball for my hd600. Will have to sell my um pro 50 to fund this purchase so I hope that it won't let me down 

Is the current shipping lead time a month from the point of order?


----------



## bigfatpaulie

uelover said:


> I have just ordered the crack + speedball for my hd600. Will have to sell my um pro 50 to fund this purchase so I hope that it won't let me down
> 
> 
> 
> ...


 
  
 I can't help you with shipping times, but I can tell you that the Crack+SB+HD600 is an outstanding combination.  It's a fun, lively, 'forget the specs and listen to the music'  setup.  Enjoy it: it really is as good as everyone says it is 
	

	
	
		
		

		
		
	


	




 .


----------



## MattTCG

uelover said:


> I have just ordered the crack + speedball for my hd600. Will have to sell my um pro 50 to fund this purchase so I hope that it won't let me down
> 
> 
> 
> ...


 
  
 I'm at four weeks tomorrow. Doc B chimed in a few pages ago and said to look for kits to go out next week, so hopefully I'll be in that group.


----------



## uelover

bigfatpaulie said:


> I can't help you with shipping times, but I can tell you that the Crack+SB+HD600 is an outstanding combination.  It's a fun, lively, 'forget the specs and listen to the music'  setup.  Enjoy it: it really is as good as everyone says it is
> 
> 
> 
> ...


 
  
 Nice to hear that! Now I just need to get past the soldering stage. I did dropped Doc B and Queen some questions but have yet to hear from them. Hope that they can answer my questions soon!
  


matttcg said:


> I'm at four weeks tomorrow. Doc B chimed in a few pages ago and said to look for kits to go out next week, so hopefully I'll be in that group.


 
  
 I hope that my waiting time will not exceed 4 weeks, as international shipping will require another 2-3 weeks >_<


----------



## uelover

I think that there is something wrong with Bottlehead's e-mail domain. My e-mail can't seem to get through. Might be related to the recent website revamp?
  
 I am worried that Doc B didn't receive my order details.


----------



## caracara08

finally got my hands on a 5998. impressive.


----------



## JamieMcC

uelover said:


> I think that there is something wrong with Bottlehead's e-mail domain. My e-mail can't seem to get through. Might be related to the recent website revamp?
> 
> I am worried that Doc B didn't receive my order details.


 
  
 I did notice this posted by Doc on the forum
  
Quote
  
  "The new shopping cart is working fine, but doesn't quite have its final appearance. The one thing that may throw some folks off is that even though orders are going through fine (and thank you for those orders!) there is - temporarily - no final confirmation page when your order is complete. We needed the website to be operational before the new style sheets can be loaded that include that page. When those are uploaded early next week the cart will have a bit more finished appearance."
  
 If still concerned try emailing in a few days time, they might have some of the bugs sorted later in the week.


----------



## benjaminhuypham

How does Crack pair with Dt880/600, buddies? I've heard Crack with Hd650 once at the meet and I was totally shocked by their sounds. They were just a "wow"," speechless", and "shaking". They sound unbelievable, probably one of the very best I've tried except BHse/009. There are very few combos that really wow me, such as Hd650/crack, Lcd2/v200, and BHsese/009. I know there are lots of more expensive options but they are just ok to my ears, never amaze me, maybe I just don't have "the golden ears".


----------



## Loquah

benjaminhuypham said:


> How does Crack pair with Dt880/600, buddies? I've heard Crack with Hd650 once at the meet and I was totally shocked by their sounds. They were just a "wow"," speechless", and "shaking". They sound unbelievable, probably one of the very best I've tried except BHse/009. There are very few combos that really wow me, such as Hd650/crack, Lcd2/v200, and BHsese/009. I know there are lots of more expensive options but they are just ok to my ears, never amaze me, maybe I just don't have "the golden ears".


 
  
 It's been a little while since I tried that combo, but it is definitely a nice pairing


----------



## JamieMcC

Lachlan congrats on the Golden ears. I started the challenge the other evening on my bed room rig but had to abort when my little one decided she wanted to use the bed as a trampoline.


----------



## UmustBKidn

doc b. said:


> When a domain moves as outs just did it takes up to 24 hours for it to propagate throughout the internet. Going from a dedicated server to cloud based makes the process a bit more complex as various parts of the site are now on various servers. My suggestion is just try again in a while. Re the images, we are aware of the issue. I have a thread started about the new website, where you guys can post bug reports so you don't have to use the bandwidth on Head Fi. Things like the images and other glitches will probably start to get fixed Monday, as the web design team needs a few well deserved days off.


 
  
 Probably his browser cache, not your server setup.
  
 I'd suggest clearing the browser cache, then trying again.


----------



## JamieMcC

umustbkidn said:


> Probably his browser cache, not your server setup.
> 
> I'd suggest clearing the browser cache, then trying again


 
 I don't think it was browser cache as I had previous already visited the new forum prior, however that's a excellent tip thanks. I was able to log in when I next tried about an hour later and have had no log in problems since. The IT guys will have plenty of bugs to keep them busy fine tuning.


----------



## Loquah

jamiemcc said:


> Lachlan congrats on the Golden ears. I started the challenge the other evening on my bed room rig but had to abort when my little one decided she wanted to use the bed as a trampoline.


 
  
 Thanks Jamie, I had to try it once I read Tyll's article about it on Inner Fidelity. There were some frustrating moments! Bottlehead fans might like to know that the Mainline amp was my reference amp to do all of the tests.
  
 For anyone interested: www.goldenears.philips.com


----------



## caracara08

picked up an expedit for my future vinyl player so I was finally able to pull the BHC out and re do my setup.
  
  

  

  
 Please excuse the dust


----------



## Aeolus Kratos

Hi there,
  
 I've been using my GEC 6AS7G brown base for about 3 months with no problems. The tube base has been a little bit loose since I received the tube but it did not have any problems back then. But about last week, my Crack started to have microphonics. I placed the Crack on my desk, and whenever I type, I hear some 'ting' sound on the left channel. I tried swapping other input tubes but it didn't work. I'm not sure if it's because of the GEC or something else. And can tube dampers solve this problem?
  
 Finally, is there any way to 'glue' the tube base somehow?
  
 Thank you very much!


----------



## Nic Rhodes

a few drops of super glue between base and glass usually solves a wobbly base fine.


----------



## Loquah

aeolus kratos said:


> Hi there,
> 
> I've been using my GEC 6AS7G brown base for about 3 months with no problems. The tube base has been a little bit loose since I received the tube but it did not have any problems back then. But about last week, my Crack started to have microphonics. I placed the Crack on my desk, and whenever I type, I hear some 'ting' sound on the left channel. I tried swapping other input tubes but it didn't work. I'm not sure if it's because of the GEC or something else. And can tube dampers solve this problem?
> 
> ...


 
  
 Do you have a different power tube you can try to confirm it's the 6AS7G or are you trying to avoid handling it give the loose base?


----------



## Sonido

Dang my Crack died today. I think a bad solder or something since I used lead-free solder (don't ever use this lead free crap) when I built it and flipping it over it, some of the solder points have browned and look quite suspect. Also, the fuse didn't blow so it's not a short, but more likely an open circuit caused by a bad solder. Only question I have is that if I have Speedball installed, what it the best way to examine and possible fix solder points underneath it?


----------



## DefQon

jamiemcc said:


>


 
  
 Didn't your Valab stepper come with terminal blocks for easy wire termination on the back end?


----------



## JamieMcC

defqon said:


> Didn't your Valab stepper come with terminal blocks for easy wire termination on the back end?


 
  
 No it didn't and I was kind of expecting it to. Wiring and soldering is straight forward enough.  If you are after one with a termination block I suggest you could always check with the seller prior to ordering.


----------



## UmustBKidn

Can anyone give me the dimensions of the bottom plate, that the components mount to? Thanks.


----------



## JamieMcC

umustbkidn said:


> Can anyone give me the dimensions of the bottom plate, that the components mount to? Thanks.


 
  
 Mine is 6 inches x 10 inches


----------



## Aussiejuggalo

So seriously considering getting this amp but I just got a few questions

Are there any other tools required apart from a soldering iron?

What kinda solder should one use for it?

Are there any particular tubes that suit the DT880s?

If you put a vinyl wrap like the 3m di-noc stuff on the bottom plate do the tubes heat it up and ruin it?

Thanks :atsmile:

P.S. you guys have made your amps look gorgeous


----------



## Loquah

sonido said:


> Dang my Crack died today. I think a bad solder or something since I used lead-free solder (don't ever use this lead free crap) when I built it and flipping it over it, some of the solder points have browned and look quite suspect. Also, the fuse didn't blow so it's not a short, but more likely an open circuit caused by a bad solder. Only question I have is that if I have Speedball installed, what it the best way to examine and possible fix solder points underneath it?


 
 1. Start visually by looking for joints that have too much solder, too little solder, or dull and dirty solder.
 2. Reheat any joints that are even slightly suspect
 3. Follow the test process from the manual to see if you can isolate the problematic joint
 4. If in doubt, reheat every joint one by one (this is a quicker option than you may think)
  
 PS reheating means applying heat until the solder completely liquifies.
  


aussiejuggalo said:


> So seriously considering getting this amp but I just got a few questions
> 
> Are there any other tools required apart from a soldering iron? *A screw driver, wire stripper of some description, a test meter (cheap is fine) and long nose pliers*
> 
> ...


----------



## dsound

sonido said:


> Dang my Crack died today. I think a bad solder or something since I used lead-free solder (don't ever use this lead free crap) when I built it and flipping it over it, some of the solder points have browned and look quite suspect. Also, the fuse didn't blow so it's not a short, but more likely an open circuit caused by a bad solder. Only question I have is that if I have Speedball installed, what it the best way to examine and possible fix solder points underneath it?


 
 Sorry to hear about your Crack.  If it were me, I'd first try to reflow all the solder-points just to make sure they were sound.  As far as getting to the area underneath the speedball (I'm assuming your talking about the tube socket wiring), I recently did this a couple weeks ago, and was able gain access by removing the screws that mounted the speedball boards to the standoff and gently moving the boards to the side.
  
 I hope your troubleshooting goes well!


----------



## dsound

I spent this morning listening to Beck's new Morning Phase album.  Through the Crack>HD600, the tracks sound fantastic, the airiness of his music lends itself well to the amp/HP pairing.


----------



## Sonido

Thanks guys. I think I'm just gonna resolder all the joints.


----------



## MattTCG

dsound said:


> I spent this morning listening to Beck's new Morning Phase album.  Through the Crack>HD600, the tracks sound fantastic, the airiness of his music lends itself well to the amp/HP pairing.


 
  
 OOOh, pm me with some details on that album. I've been waiting for this one.


----------



## skeptic

sonido said:


> Thanks guys. I think I'm just gonna resolder all the joints.


 
  
 Sonido - can you tell us which, if any, of the LED's and/or tube heaters are coming on right now?  It may be possible to narrow this down a bit and avoid having to pull your speedball boards. If your heaters aren't coming up (no tube glow at all?), for example, that narrows things down a lot.


----------



## Sonido

skeptic said:


> Sonido - can you tell us which, if any, of the LED's and/or tube heaters are coming on right now?  It may be possible to narrow this down a bit and avoid having to pull your speedball boards. If your heaters aren't coming up (no tube glow at all?), for example, that narrows things down a lot.



No tube glow from either tube. I'll have to check LED's when I get home.


----------



## skeptic

sonido said:


> No tube glow from either tube. I'll have to check LED's when I get home.


 
  
 That's actually good news from a trouble shooting standpoint.  Since your heaters run off ac, straight from the main transformer, I think you can pretty much focus on the joints on your transformer terminals and IEC outlet and ignore all else until the tubes light up.  Are you sure it isn't just your fuse?  Per the directions when measuring voltages set forth in the manual, take some measurements on the IEC pins and transformer terminals and let us know if power is getting to the transformer.  Sounds very much like it isn't.  Good luck!


----------



## Sonido

skeptic said:


> That's actually good news from a trouble shooting standpoint.  Since your heaters run off ac, straight from the main transformer, I think you can pretty much focus on the joints on your transformer terminals and IEC outlet and ignore all else until the tubes light up.  Are you sure it isn't just your fuse?  Per the directions when measuring voltages set forth in the manual, take some measurements on the IEC pins and transformer terminals and let us know if power is getting to the transformer.  Sounds very much like it isn't.  Good luck!



I'll check the fuse again. Might as well replace it since I have spares. I'm using 0.5 amps slow blow because I blew the original fuse due to a short when I first finished building the Crack, and I wanted to get a 1 amp slow blow, but Radioshack only had 0.5 amp and it worked fine.

Another thing is I was in the middle of plugging my headphones in when it died. I do believe unlike other times, I was plugging it in slower than normal, and it got stuck a bit halfway. Maybe this caused a short? Either that or the vibration of plugging in shook loose a solder joint.


----------



## brunk

sonido said:


> I'll check the fuse again. Might as well replace it since I have spares. I'm using 0.5 amps slow blow because I blew the original fuse due to a short when I first finished building the Crack, and I wanted to get a 1 amp slow blow, but Radioshack only had 0.5 amp and it worked fine.
> 
> Another thing is I was in the middle of plugging my headphones in when it died. I do believe unlike other times, I was plugging it in slower than normal, and it got stuck a bit halfway. Maybe this caused a short? Either that or the vibration of plugging in shook loose a solder joint.


 
 Remember to use a bit higher heat than normal, I sit around 350-375 celsius on my dial with a 2-3mm chisel tip. This will reduce dwell time and allow you to work faster too. Double check that you have good mechanical connections too when you suck the old solder out. Hopefully that'll help you


----------



## JamieMcC

Every now and then I like to get out and play Jeff Wayne's Musical Version of The War of the Worlds the 1978 version with the narration by Richard Burton. I havn't done so for a while and was truly surprised at how good it is through the Crack the spoken narration and sound effects are just excellent.


----------



## dsound

sonido said:


> Another thing is I was in the middle of plugging my headphones in when it died. I do believe unlike other times, I was plugging it in slower than normal, and it got stuck a bit halfway. Maybe this caused a short? Either that or the vibration of plugging in shook loose a solder joint.


 

 I don't think you can short your Crack by partially plugging in your headphones; that being said the act of plugging in the phones could have shaken a bad-joint loose.  That happened to me, I used to get a nasty "pop!" every once in a while when I plugged my phones in and I traced it to a bad ground wire-connection.
  
 Hope you get this solved soon


----------



## Sonido

Just got home. Confirmed that it's not a fuse problem, and none of the LEDs light up. Looks like bad solder somewhere.


----------



## Sonido

Well that was easy. 
	

	
	
		
		

		
			




  
 Resoldered 5 or 6 solder joints that looked suspect. Added some *leaded *solder for good measure. Two were definitely bad and moved upon touching. I guess lesson learned here is unlike cars and gasoline, lead is good here. Actually, I learned this lesson a while back and built my Quickie with leaded solder, but it seems the mistake of using lead-free solder keeps coming back to bite. For those that don't know the difference between the solder types, lead-free solder has a higher melting point so it's harder to get it to the right temperature resulting in cold solders.


----------



## DefQon

jamiemcc said:


> No it didn't and I was kind of expecting it to. Wiring and soldering is straight forward enough.  If you are after one with a termination block I suggest you could always check with the seller prior to ordering.


 
  
 I have about 14 of them from an order I made over a year ago so it's all good. Just wondering why yours didn't come with the end terminal blocks for easy fast secure termination.


----------



## Loquah

jamiemcc said:


> Every now and then I like to get out and play Jeff Wayne's Musical Version of The War of the Worlds the 1978 version with the narration by Richard Burton. I havn't done so for a while and was truly surprised at how good it is through the Crack the spoken narration and sound effects are just excellent.


 
  
 I love that album!!
  
 Haven't specifically listened to it through the Bottlehead amps though - a track here or there, but not the whole album so I haven't really gotten into the moment with it


----------



## Aussiejuggalo

Loquah, Thanks you really dont need much to build these things 

Sonido, Lucky I was following the problems with your Crack, was thinking about using some lead free solder if I end up buying one of these


----------



## brunk

aussiejuggalo said:


> Loquah, Thanks you really dont need much to build these things
> 
> 
> 
> ...


 
 Yeah, treat yourself to some 63/37 solder (smallest diameter you can get), a flux pen, a 2-3mm chisel tip and you'll be spared of these common issues when new to soldering 
  
 EDIT: Don't be shy on the heat either. If you find yourself waiting over 5-7 seconds for the solder flow, crank it up.


----------



## Aussiejuggalo

brunk said:


> Yeah, treat yourself to some 63/37 solder (smallest diameter you can get), a flux pen, a 2-3mm chisel tip and you'll be spared of these common issues when new to soldering
> 
> EDIT: Don't be shy on the heat either. If you find yourself waiting over 5-7 seconds for the solder flow, crank it up.




So chisel tip is easier then pencil for this kinda stuff? I use a pencil on wire, thats about as far as my soldering knowledge goes 

Gonna probably get flamed... what does flux do again? I forgot lol 

One good thing with my soldering iron is it can do 30 or 60w, I dont have one of those fancy soldering stations just a good ol' wall plug


----------



## DefQon

aussiejuggalo said:


> Gonna probably get flamed... what does flux do again? I forgot lol


 
  
 Fluxcapacitor = more jiggawatts.


----------



## Loquah

aussiejuggalo said:


> So chisel tip is easier then pencil for this kinda stuff? I use a pencil on wire, thats about as far as my soldering knowledge goes
> 
> 
> 
> ...


 
  
  


defqon said:


> Fluxcapacitor = more jiggawatts.


 
  
 LOL
  
 Flux is the liquidy stuff that helps the solder to flow onto the joints and make a strong connection


----------



## Aussiejuggalo

defqon said:


> Fluxcapacitor = more jiggawatts.








loquah said:


> Flux is the liquidy stuff that helps the solder to flow onto the joints and make a strong connection




Ah ok, I was gonna ask if it was something like that, thanks 

1 more question, seeing the crack is a tube amp can it run for say 16 hours non stop or does it have to be turned off to allow the tubes to cool? I really am a n00b with audio


----------



## Armaegis

A chisel tip basically just offers more surface area and more mass to hold heat (and thus more heat transfer).
  
 Flux is a heat activated mild acid paste that cleans the surface of the materials you want to join so the solder will actually flow/stick to the surface (oxidized/dirty surfaces will not heat properly and repel solder).
  
 edit: ah whoops, didn't notice the answer was already on the next page


----------



## mcandmar

Flux is a cleaning agent basically, dissolves grease and oxidation from the surface of metals to ensure a good clean surface to bond to.  I highly recommend you buy rosin core leaded solder, i.e. with the flux built in.   The flex pens are really only useful for circuit board use.
  
 /edit: also way too slow...


----------



## Aussiejuggalo

armaegis said:


> A chisel tip basically just offers more surface area and more mass to hold heat (and thus more heat transfer).
> 
> Flux is a heat activated mild acid paste that cleans the surface of the materials you want to join so the solder will actually flow/stick to the surface (oxidized/dirty surfaces will not heat properly and repel solder).
> 
> edit: ah whoops, didn't notice the answer was already on the next page :rolleyes:







mcandmar said:


> Flux is a cleaning agent basically, dissolves grease and oxidation from the surface of metals to ensure a good clean surface to bond to.  I highly recommend you buy rosin core leaded solder, i.e. with the flux built in.   The flex pens are really only useful for circuit board use.
> 
> /edit: also way too slow...




hahaha yeah both to slow but still thank you none the less


----------



## brunk

It's not too slow really, and it's especially helpful if you're a beginner with soldering. One quick dab could save you from a bad joint, and you'll see that solder flow like water 
  
 Better for a beginner to spend some extra seconds dabbing than troubleshooting. To the contrary, I use flux more with point-to-point than a PCB, the flux in core is adequate for the boards 99% of time. You have a lot of surface area for the flux to cover with those terminals though.


----------



## Armaegis

I'm in the habit of very lightly tinning most of the terminals before I even start wiring. Apply some flux to everything, get some solder on the iron tip, then very quickly and lightly touch it to everything. It's really not necessary for most jobs, but it does make the work easier sometimes.


----------



## Aussiejuggalo

brunk said:


> It's not too slow really, and it's especially helpful if you're a beginner with soldering. One quick dab could save you from a bad joint, and you'll see that solder flow like water
> 
> Better for a beginner to spend some extra seconds dabbing than troubleshooting. To the contrary, I use flux more with point-to-point than a PCB, the flux in core is adequate for the boards 99% of time. You have a lot of surface area for the flux to cover with those terminals though.




Thats true, I have found when I solder wires together less is more, to much and it kinda turns to crap... or just turns black 

Yeah I'd rather spend extra time soldering and making sure its right then quickly building it and have something go wrong :eek: plus I gotta be careful seeing my hands really arnt that steady 



armaegis said:


> I'm in the habit of very lightly tinning most of the terminals before I even start wiring.




Doesnt lightly tinning then soldering mean its a much stronger and more conductive bond?



armaegis said:


> Apply some flux to everything, get some solder on the iron tip, then very quickly and lightly touch it to everything. It's really not necessary for most jobs, but it does make the work easier sometimes.




I also thought that was the "correct" way to solder anyway

Side note I tried soldering some old 22AWG wires just to see how it would go, really small black spots where I guess it burnt? and yellow spots guessing flux?, but they all more or less came out nice and shiny ... think its time to get me some crack


----------



## Armaegis

Pre-treating/tinning/fluxing isn't necessary. Most of the time flux-cored solder is sufficient to get everything to flow. Myself, I often find myself lacking in extra hands, since I'll have one hand holding the iron and the other is holding whatever component/wire/thingamajig in place. So since I can't bring in the solder wire, I'll tin the surfaces then add a dab of flux and then bring in some solder on the iron tip and let it wick itself into the joint.
  
 One if these days I'll have to get myself a proper set of "helping hands". The $5 one I have is a piece of junk that's only good as a paperweight.


----------



## Aussiejuggalo

armaegis said:


> Pre-treating/tinning/fluxing isn't necessary. Most of the time flux-cored solder is sufficient to get everything to flow. Myself, I often find myself lacking in extra hands, since I'll have one hand holding the iron and the other is holding whatever component/wire/thingamajig in place. So since I can't bring in the solder wire, I'll tin the surfaces then add a dab of flux and then bring in some solder on the iron tip and let it wick itself into the joint.
> 
> One if these days I'll have to get myself a proper set of "helping hands". The $5 one I have is a piece of junk that's only good as a paperweight.




Ah yeah I can see how that would be easier. Sometimes I end up just holding the solder in my mouth... is that bad? 

I got helping hands  kinda useful but for something like the crack maybe not so much

I think I forgot to ask this earlier, my DT880s are the the 250 ohm versions... thats not a problem for this amp is it? I read that it really love 600 ohm ones better


----------



## JamieMcC

Aussiejuggalo said:
			
		

> /img/forum/go_quote.gif
> 
> 1 more question, seeing the crack is a tube amp can it run for say 16 hours non stop or does it have to be turned off to allow the tubes to cool? I really am a n00b with audio


 
  
 Mine has been running 16hrs a day for the last 8 weeks while I've been doing some capacitor testing with no problems. It is raised up about 8 mm on some feet so there is some air flow underneath. The air temps is around 16-20 degree C in the house. I have been using some cheap headphones and tubes for testing and my other half looks in on it from time to time and has a listen while I am at work. Its feed radio or random play via server.


----------



## Aussiejuggalo

jamiemcc said:


> Mine has been running 16hrs a day for the last 8 weeks while I've been doing some capacitor testing with no problems. It is raised up about 8 mm on some feet so there is some air flow underneath. The air temps is around 16-20 degree C in the house. I have been using some cheap headphones and tubes for testing and my other half looks in on it from time to time and has a listen while I am at work. Its feed radio or random play via server.




So I guess no problems with tubes getting to hot and exploding them?


----------



## mullardpassion

aussiejuggalo said:


> So I guess no problems with tubes getting to hot and exploding them?


 
 lol, unless you're using some kinda nuclear caps


----------



## roguegeek

I see there are a lot of positive impressions of the Crack with the HD 800. Does everyone still feel that way about it? Worth the price of admission?


----------



## UmustBKidn

sonido said:


> I'll check the fuse again. Might as well replace it since I have spares. I'm using 0.5 amps slow blow because I blew the original fuse due to a short when I first finished building the Crack, and I wanted to get a 1 amp slow blow, but Radioshack only had 0.5 amp and it worked fine.


 
 Glad to hear you figured it out.
  
 Does the kit come with a slow blow fuse? Personally, I would not use a slow blow fuse unless that was specified by BH. I would also never use a larger value than specified (though you can use a smaller value if that works).


----------



## Loquah

umustbkidn said:


> Glad to hear you figured it out.
> 
> Does the kit come with a slow blow fuse? Personally, I would not use a slow blow fuse unless that was specified by BH. I would also never use a larger value than specified (though you can use a smaller value if that works).


 
  
 1A quick blow fuses seem to be the norm in the headphone amps from Bottlehead


----------



## DefQon

A friend of mine has been running his modded Crack/SB that I built for him late last August since, has not powered it off at all, he leaves all his audio stuff on 24/7.


----------



## Aussiejuggalo

mullardpassion said:


> lol, unless you're using some kinda nuclear caps




I only ask coz I know some tube amps like the Woo Audio WA7 Fireflies say not to run it for more then 8 hours or something



defqon said:


> A friend of mine has been running his modded Crack/SB that I built for him late last August since, has not powered it off at all, he leaves all his audio stuff on 24/7.




:eek: those tubes must be red hot :eek:


----------



## DefQon

aussiejuggalo said:


> I only ask coz I know some tube amps like the Woo Audio WA7 Fireflies say not to run it for more then 8 hours or something
> 
> 
> 
> ...


 
 Tubes can withstand the heat but I'm surprised his tubes are still going strong.
  
 He has 2 Manley Stingrays. Now those are real heaters.


----------



## Doc B.

The amp is designed for continuous operation. The heaters in the tubes slowly lose their emissive coating over time. Figure about 5000 hours lifetime for the 6080 and 10,000 for the 12AU7. The electrolytic capacitors may need replacement at around 10,000 hours too. We have had a few of our older kits come in for service (maybe 15+ years old) that ran the capacitors much harder than in the Crack and some of them needed a cap replaced. 

10,000 hours is very roughly 5 years running for 8 hours per workday (like at your office workstation) or 20 years running a couple hours an evening after work.

Re the question about HD800s and Crack - it works great. If you're going to buy $1500 headphones, I'd suggest really doing right by them and matching them to the Mainline. It's even more betterer.


----------



## Shaldome

Finished my Crack yesterday. Wanted to build it during my week of last week, but lost one of the shoulder washer for the bottom of the transformer and had to wait a week for a replacement (thanks again to Eileen for the quick response!)
 Only problem I had after finishing it was, that it did not turn on when I was going to do the voltage checks. Turns out I missed to solder one cable at B7L. After soldering it everything worked fine, although the points where I should have 90 V I only have 76 V. But I guessed that was inside the tolerance level.
 Other than that it is not the most beautiful build of a Crack, but it is mine.  I blame the scorched isolation of the cable to my lack of depth perception, which I was made aware of during soldering.
 Next week end I will try to install the speedball upgrade. For now I like what I am hearing. Was a bit bummed by the lack of loudness and background noise, but it turned out to be my ODAC/AMP. When I use my Ibasso DX 50 as a source everything is perfect.


----------



## skeptic

aussiejuggalo said:


> Ah yeah I can see how that would be easier. Sometimes I end up just holding the solder in my mouth... is that bad?
> 
> I got helping hands  kinda useful but for something like the crack maybe not so much
> 
> I think I forgot to ask this earlier, my DT880s are the the 250 ohm versions... thats not a problem for this amp is it? I read that it really love 600 ohm ones better




Hey AJ - yes 250 ohm dt880s sound great with the crack. I tend to prefer Senns most days, as a matter of subjective preference, but could live very happily with my dt880's regardless. They are an excellent pairing.


----------



## dsound

shaldome said:


> Finished my Crack yesterday. Wanted to build it during my week of last week, but lost one of the shoulder washer for the bottom of the transformer and had to wait a week for a replacement (thanks again to Eileen for the quick response!)


 
 Congrats on finishing the build!  Please post pics when you can.  What headphones are you listening with?


----------



## roguegeek

roguegeek said:


> I see there are a lot of positive impressions of the Crack with the HD 800. Does everyone still feel that way about it? Worth the price of admission?


 
 Thoughts?


----------



## brunk

roguegeek said:


> Thoughts?


 
 I really liked the pairing when I had the HD-800s, so I think it's definitely worth the price of admission. Definitely not letting go of my Crack either, it'll collect dust until I get another high impedance headphone. I sold the HD-800 because I enjoy the HE-6 more, I was mainly using it as an expensive evaluation tool and for classical music lol, so it got sent off to a better home.


----------



## roguegeek

brunk said:


> I really liked the pairing when I had the HD-800s, so I think it's definitely worth the price of admission. Definitely not letting go of my Crack either, it'll collect dust until I get another high impedance headphone. I sold the HD-800 because I enjoy the HE-6 more, I was mainly using it as an expensive evaluation tool and for classical music lol, so it got sent off to a better home.


 
 And the reason you aren't using it right now is because you just don't have anything to currently use it with?


----------



## brunk

roguegeek said:


> And the reason you aren't using it right now is because you just don't have anything to currently use it with?


 
 Yep.


----------



## Sonido

roguegeek said:


> Thoughts?



It's great. Makes the HD800 quite musical, though at the expense of detail. I found the Vali to be better in details, but thinner sounding.


----------



## MattTCG

sonido said:


> It's great. Makes the HD800 quite musical, though at the expense of detail. I found the Vali to be better in details, but thinner sounding.


 
  
 I heard it the same way. I only had a brief audition with the crack/hd800/Vali. I preferred the crack by a good margin.


----------



## roguegeek

It looks like a lot of fun, so I'm going to order a kit no matter what just to play around with. If I were to order it, I want to do the Speedball upgrade right away. Would purchasing the kit and the upgrade together still allow me to build the unit without the upgrade? The reason I'm asking is because I want to build the Crack in its stock form so I can see what the stock signature sounds like before moving to the Speedball upgrade at a later date.


----------



## skeptic

Yup.  That's the way it is intended to be done.


----------



## Sonido

roguegeek said:


> It looks like a lot of fun, so I'm going to order a kit no matter what just to play around with. If I were to order it, I want to do the Speedball upgrade right away. Would purchasing the kit and the upgrade together still allow me to build the unit without the upgrade? The reason I'm asking is because I want to build the Crack in its stock form so I can see what the stock signature sounds like before moving to the Speedball upgrade at a later date.



Of course, and it's recommended that way anyways. Helps isolate which part you screwed up on as well.


----------



## roguegeek

skeptic said:


> Yup.  That's the way it is intended to be done.


 
  


sonido said:


> Of course, and it's recommended that way anyways. Helps isolate which part you screwed up on as well.


 
  
 Gotcha. I was just making sure that if you order it together, they aren't automatically removing some parts that may be needed for the base kit, but aren't needed with the Speedball. The price is slightly cheaper when you order it together.


----------



## dxanex

lol I can't even remember what stock Crack sounds like anymore. All my builds except the very first a couple of years ago have had the Speedball installed in the get-go. Just be aware that installing the Speedball after the fact does require some unsoldering and dismantling of a few components. Nothing too crazy, though.
  
 Even with Speedball, I did hear a noticeable improvement upgrading the output tube to a Tung-Sol 5998. Worth every penny IMO, and a highly recommended upgrade to anyone wanting to get the most mileage and versatility out of their Crack. Simply sublime with the HD 650.


----------



## olegausany

When I had Crack I really enjoyed 5998 paired with Syllvania 8514 which I still have for sale


----------



## Acknown3

Hey guys, I'm about to get a Crack and have a quick question. I'm using an Aune T1 with an Amperex OG 7308 tube right now. From my quick googling, it looks like the 7308 isn't compatible, so what tubes (around or under $100) would you guys suggest with the Crack as an upgrade, mainly focusing on soundstage?
  
 Also, is the Aune fine as a DAC, or would that be something that I should look into upgrading later?


----------



## trentrosa

Doc, the new Bottlehead website looks great! Nicely done.


----------



## Aussiejuggalo

doc b. said:


> The amp is designed for continuous operation. The heaters in the tubes slowly lose their emissive coating over time. Figure about 5000 hours lifetime for the 6080 and 10,000 for the 12AU7. The electrolytic capacitors may need replacement at around 10,000 hours too. We have had a few of our older kits come in for service (maybe 15+ years old) that ran the capacitors much harder than in the Crack and some of them needed a cap replaced.
> 
> 10,000 hours is very roughly 5 years running for 8 hours per workday (like at your office workstation) or 20 years running a couple hours an evening after work.
> 
> Re the question about HD800s and Crack - it works great. If you're going to buy $1500 headphones, I'd suggest really doing right by them and matching them to the Mainline. It's even more betterer.




That life span for the parts combined is insane, I know some parts in graphic cards, motherboards etc that arnt even rated for that long :eek:



skeptic said:


> Hey AJ - yes 250 ohm dt880s sound great with the crack. I tend to prefer Senns most days, as a matter of subjective preference, but could live very happily with my dt880's regardless. They are an excellent pairing.




Ah cool , just wasnt sure coz there only 250 ohm and most of you guys seem to run 600 ohm

Got another question , are there any combo of tubes that make the crack sound as natural and neutral as possible?


----------



## Loquah

acknown3 said:


> Hey guys, I'm about to get a Crack and have a quick question. I'm using an Aune T1 with an Amperex OG 7308 tube right now. From my quick googling, it looks like the 7308 isn't compatible, so what tubes (around or under $100) would you guys suggest with the Crack as an upgrade, mainly focusing on soundstage?
> 
> Also, is the Aune fine as a DAC, or would that be something that I should look into upgrading later?


 
  
 The Aune will do well as your Crack's DAC 
	

	
	
		
		

		
			





, but you will get better results with a better DAC in the future.
  
 I really like the Mullard 6080WA and either Mullard ECC82 (super warm combo) or RCA Cleartop 12AU7 (more neutral combo) for a well-priced set. The Mallards have a really solid, almost holographic presentation that I loved from a staging perspective. Just beware though that Mullard + Mullard can be too thick and warm for some setups.


----------



## olegausany

I would use 5998 and 8514A from Sylvania or GE


----------



## Doc B.

trentrosa said:


> Doc, the new Bottlehead website looks great! Nicely done.


 
 Thank you. The bulk of the credit goes to the guys at Helix Creative. We've been on the web for so long that they had to scrape through 18 years of waxy buildup to get down to the useful bits and rebuild the site from there. Now that we have it up I can say that this was not a trivial job, construction started last August. Aside from a last minute glitch regarding service providers, root level access, zoning and domain ownership on Friday that resulted in my having a nosebleed (literally) it all went pretty smoothly. I'm really thrilled that most of the new site is Wordpress based and thus very easy to update. We have a few more bugs to work out but we are about 99% functional. Look for a jump in performance in the next few days as we get set up with our CDN.


----------



## mordicai

My favorite tubes have been the 5998 and one of the E80cc tubes. Latey Ive been using a NOS Phillips Miniwatt SQ tube which I love.  I will be listing an extra that I have on the for sale forum this week.


----------



## spacequeen7

acknown3 said:


> Hey guys, I'm about to get a Crack and have a quick question. I'm using an Aune T1 with an Amperex OG 7308 tube right now. From my quick googling, it looks like the 7308 isn't compatible, so what tubes (around or under $100) would you guys suggest with the Crack as an upgrade, mainly focusing on soundstage?
> 
> Also, is the Aune fine as a DAC, or would that be something that I should look into upgrading later?


 
 you will be fine with that set up ,I'm using Aune T1 with Crack and love it and you don't need " better DAC" -Aune T1 do very well with Amperex +[Crack]GEC 6AS7G A1834 Round Base here ,I found 5998 to be lacking some detail on Crack (more evident on Crack vs DV336SE I own)


----------



## diaBoliQu3

spacequeen7 said:


> you will be fine with that set up ,I'm using Aune T1 with Crack and love it and you don't need " better DAC" -Aune T1 do very well with Amperex +[Crack]GEC 6AS7G A1834 Round Base here ,I found 5998 to be lacking some detail on Crack (more evident on Crack vs DV336SE I own)


 
 Finally! Someone with Aune T1 and Crack. I use 6DJ8 single leg... So, what else DAC you compared with? Are you saying better DAC is the same with Aune T1? My Crack+balls will shipped to me next week. And I can't wait it anymore...


----------



## Loquah

diaboliqu3 said:


> Finally! Someone with Aune T1 and Crack. I use 6DJ8 single leg... So, what else DAC you compared with? Are you saying better DAC is the same with Aune T1? My Crack+balls will shipped to me next week. And I can't wait it anymore...


 
  
 Although I don't own an Aune T1 like @spacequeen7 I have spent some time with the T1 and can confirm that it is a very good DAC (esp. for the price), but there are other DACs that are significantly better - they're just also significantly more expensive... You'll find that upgrading your DAC will make a difference to the sound from the Crack. The following is from the Bottlehead Discussion Thread (http://www.head-fi.org/t/683012/bottlehead-amplifier-discussion-comparison-thread-crack-sex-mainline) from my comparison reviews of the Crack, S.E.X., and Mainline. I was blown away by how good the Crack could sound with a high end DAC. Although I upgraded from an Audio-gd NFB-5.2 rather than an Aune T1, I would say they are on par (having listened to both) although the T1 is probably a little more neutral.
 


> DAC Upgrade Update - 27th October 2013 A recent upgrade to my DAC has brought some very interesting changes.
> 
> The new DAC is a Matrix X-Sabre based on the very detailed ES9018 Sabre DAC chip. The extra separation and clarity offered by this DAC (compared to the previous Audio-gd NFB-5.2) has brought the Crack (with Speedball) very close to the S.E.X. in terms of overall sound performance. It's so close now that I could actually be completely happy with either amp when driving the Beyerdynamic T1s. For lower impedance cans, the S.E.X. is still the only choice due to the Crack's high output impedance, but with high impedance Beyerdynamic or Sennheiser cans I would probably choose the Crack simply because it is cheaper and still excellent.
> 
> I think the key to this change is the signature of the DACs. The NFB-5.2 was slightly warmer than the X-Sabre. The X-Sabre is still musical, but a little closer to neutral than the NFB-5.2. The result is a cleaner sound from the Crack - still warm and rich, but not smoothed over at all. The S.E.X. can sound a little dry at times in comparison which makes the Crack a bit more seductive - it soothes the ears with detailed, mellow tunes while the S.E.X. presents oodles of details and clarity, but isn't always soothing.


----------



## Armaegis

dxanex said:


> lol I can't even remember what stock Crack sounds like anymore. All my builds except the very first a couple of years ago have had the Speedball installed in the get-go. Just be aware that installing the Speedball after the fact does require some unsoldering and dismantling of a few components. Nothing too crazy, though.


 
  
 I highly recommend reading through the speedball manual before starting the Crack build though, and make a couple small changes during the initial build:
 - note of which resistors will be cut off for the upgrade and install them with a bit of extra lead spacing to they're easier to cut
 - some caps will be bent into a new position, so you might as well install that way from the start
 - the speedball boards mount onto some spacers, which are much easier installed at the very beginning because trying to finagle those little tiny nuts (that's what she said?) is rather tricky when you have all the other components soldered in place


----------



## skeptic

Adding to the above, and as to the output caps, I'd say mount them on 3-4" fly leads so you can easily drop in film caps at some point down the road!


----------



## punit

Bought this 6SN7 to 12AU7  adapter :
  
 http://www.ebay.com/itm/300980566962?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
  
 Received it yesterday, had read a lot of comments here & on the BH forum about humming with such kind of adapters, so wasn't really expecting much. Tried it yesterday for 15 mins with the following tubes :
  
KEN-RAD BLACK GLASS 6SN7GT Tung-Sol Black Plate FAT D Getter 6SN7 GTB
  
Sophia Electric Grade A 6SN7
  
 Could not hear any hum 
	

	
	
		
		

		
			





 Yay.. This opens up a world of possibilities 
	

	
	
		
		

		
		
	


	




 Fingers Crossed that the no hum situation continues.


----------



## roguegeek

armaegis said:


> I highly recommend reading through the speedball manual before starting the Crack build though, and make a couple small changes during the initial build:
> - note of which resistors will be cut off for the upgrade and install them with a bit of extra lead spacing to they're easier to cut
> - some caps will be bent into a new position, so you might as well install that way from the start
> - the speedball boards mount onto some spacers, which are much easier installed at the very beginning because trying to finagle those little tiny nuts (that's what she said?) is rather tricky when you have all the other components soldered in place


 
 If I were to just build it out with the Speedball upgrade right away, are the instructions not linear in describing how to do this or am I going to need to connect the dots between two separate instructions?


----------



## spacequeen7

diaboliqu3 said:


> Finally! Someone with Aune T1 and Crack. I use 6DJ8 single leg... So, *what else DAC you compared with?* Are you saying better DAC is the same with Aune T1? My Crack+balls will shipped to me next week. And I can't wait it anymore...


 
 other then Aune T1 only Schiit Modi (one day) and with the right tube T1 sounds great (best three tube combo 6922 Amperex or Mullard [ Aune] +Haltron GEC/unknown 12AU7 [Crack] ) ,I already ordered some film replacements and pot  
  


punit said:


> Bought this 6SN7 to 12AU7  adapter :
> 
> http://www.ebay.com/itm/300980566962?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
> 
> ...


 
 I should be getting this in few days (I have few very nice 6SN7 tubes..can't wait to try them on Crack  )
 http://www.ebay.com/itm/1pc-convert-tube-socket-12AU7-12AX7-to-6SN7-6SL7-/321333602172?pt=US_Home_Audio_Amplifiers_Preamps&hash=item4ad0f9a77c
  
 P.S. how you like "Tung-Sol Black Plate FAT D Getter 6SN7 GTB" and what's your power tube  ?


----------



## diaBoliQu3

spacequeen7 said:


> other then Aune T1 only Schiit Modi (one day) and with the right tube T1 sounds great (best three tube combo 6922 Amperex or Mullard [ Aune] +Haltron GEC/unknown 12AU7 [Crack] ) ,I already ordered some film replacements and pot
> 
> I should be getting this in few days (I have few very nice 6SN7 tubes..can't wait to try them on Crack  )
> http://www.ebay.com/itm/1pc-convert-tube-socket-12AU7-12AX7-to-6SN7-6SL7-/321333602172?pt=US_Home_Audio_Amplifiers_Preamps&hash=item4ad0f9a77c
> ...


 
 So, which one you preferred? Modi or Aune T1+ Crack?


----------



## diaBoliQu3

loquah said:


> Although I don't own an Aune T1 like @spacequeen7 I have spent some time with the T1 and can confirm that it is a very good DAC (esp. for the price), but there are other DACs that are significantly better - they're just also significantly more expensive... You'll find that upgrading your DAC will make a difference to the sound from the Crack. The following is from the Bottlehead Discussion Thread (http://www.head-fi.org/t/683012/bottlehead-amplifier-discussion-comparison-thread-crack-sex-mainline) from my comparison reviews of the Crack, S.E.X., and Mainline. I was blown away by how good the Crack could sound with a high end DAC. Although I upgraded from an Audio-gd NFB-5.2 rather than an Aune T1, I would say they are on par (having listened to both) although the T1 is probably a little more neutral.
 
 Holy sh!t, $1000 for Matrix X-Sabre. I will never afford that. Sad... What other DAC you have tested within $300 to below range but definitely better than Aune T1 sir?


----------



## Shaldome

dsound said:


> Congrats on finishing the build!  Please post pics when you can.  What headphones are you listening with?



 


Here are two photos from the up and downside:









Sorry, for the bad quality of the second one, I tried to experiment with my camera on this one.

And I listen to my Beyerdynamics T1, which I bought last christmas as an upgrade from my Senheiser HD-650.


----------



## Aussiejuggalo

The tubes... they look purple!!!  Good job :atsmile:

Do you guys twist all the cables or do they come like that?


----------



## Shaldome

aussiejuggalo said:


> The tubes... they look purple!!!
> 
> 
> 
> ...


 
  
 You have to twist them yourself. I used a crocodile clip on one end and twisted with a plier on the other end.


----------



## Aussiejuggalo

shaldome said:


> You have to twist them yourself. I used a crocodile clip on one end and twisted with a plier on the other end.




Ah ok cool  thanks


----------



## dxanex

roguegeek said:


> If I were to just build it out with the Speedball upgrade right away, are the instructions not linear in describing how to do this or am I going to need to connect the dots between two separate instructions?




There will be 4 total resistors that you will NOT install that the original instructions would have you install. And as others have said you will also bend a few caps down to make room for the Speedball. Best bet is read through the speedball instructions first and write down the resistors that are no longer needed, and skip those steps during the initial build.


----------



## Doc B.

My take on this is if you have to ask how to incorporate the Speedball in the initial build, you shouldn't be trying it. We get asked about this _every week_. And we stand firmly on the principle that you should build the basic kit first, then add the upgrade. I suggest looking at the threads on the Bottlehead Forum regarding trouble shooting Crack builds. They often start with "I built my Crack with the Speedball and I'm getting funny readings". 

In a lot of our kits you build up a certain part of the circuit and test it before going on. Building the basic Crack kit is one of those kinds of things. Once you have the basic circuit shaken out you can add the upgrade with confidence that any issues that show up are related to the new installation. That can save you from having to hear us say for the umpteenth time "remove the C4S boards, put the plate resistors in, remeasure everything and figure out what you miswired in the rest of the circuit. Then put the C4S boards back in". That's when the build can start to get messy.


----------



## dsound

shaldome said:


> Sorry, for the bad quality of the second one, I tried to experiment with my camera on this one.
> 
> And I listen to my Beyerdynamics T1, which I bought last christmas as an upgrade from my Senheiser HD-650.


 
  
 Looks great!  I've always wanted to listen to the T1 through the Crack 
	

	
	
		
		

		
		
	


	




.
 Happy Listening!
  
 (It may be a non-issue, but if you experience signal interference, you may want to consider a tighter-twist on your input-wiring.)


----------



## lokesen

I made this little write-up illustrating the process of making the Bottlehead Crack and modding it.
  
 There are 5 parts, but I'm still missing one article about capacitor upgrades for now. I hope you'll find some inspiration here, if you haven't made a Bottlehead Crack yet. 
  
 Cabinet and Chassis http://diy.koenigs.dk/2014/02/20/6/
 Mounting the Parts http://diy.koenigs.dk/2014/02/20/mounting-the-parts/
 Soldering the components http://diy.koenigs.dk/2014/02/21/soldering-the-components/ 
 Speedball Upgrade - http://diy.koenigs.dk/2014/02/25/speedball-upgrade/
 Capacitor Hot-Rod'ing - http://diy.koenigs.dk/2014/02/26/hot-rodding-with-film-caps/


----------



## Armaegis

roguegeek said:


> If I were to just build it out with the Speedball upgrade right away, are the instructions not linear in describing how to do this or am I going to need to connect the dots between two separate instructions?


 
  
 1) clear two big spaces, one to do the actual work, the other to lay out all your components (using the sticky bubble wrap is great for this so they don't roll around
 2) read through the crack manual, lay out all the components in a logical order, cut/strip/tin wires ahead of time if you want to (lots of prep time, but makes life easier)
 3) read through the speedball manual, lay stuff out, etc. you can actually populate the boards as a separate project so feel free
 3b) note the four resistors which you'll be replacing in the crack, and remove or mark them from step 2
 3c) note the capacitors which will be bent/moved and mark them as well
 4) start all the hardware assembly for the Crack, stop before any soldering stuff
 5) go back to your speedball stuff and attach the mounting hardware there
 6) lunch
 7) proceed with crack assembly, omit the four resistors, and when you get to the caps look at the orientation in the speedball manual
 8) recreational beverage
 9) keep building
 10) register for the forums at bottlehead for the inevitable troubleshooting
 11) keep building
 12) sleep?
 13) build, install speedball components, check all the thingies
 14) music?


----------



## punit

spacequeen7 said:


> P.S. how you like "Tung-Sol Black Plate FAT D Getter 6SN7 GTB" and what's your power tube  ?


 
 I have tried them with TS 5998 & GEC 6AS7G. They are quite smooth & work well with GEC 6AS7G & HD 800. Both TS together may be too smooth for some, works great with bright HP's though.


----------



## Loquah

diaboliqu3 said:


> Holy sh!t, $1000 for Matrix X-Sabre. I will never afford that. Sad... What other DAC you have tested within $300 to below range but definitely better than Aune T1 sir?


 
  
 Yeah, I had to work my way up to the X-Sabre.
  
 In terms of other DACs below $300, I'm not sure there are many that are definitively better than the Aune T1. The T1 is very good so I'd stick with that unless you want to spend $500-600 at which stage DACs like the Matrix Mini (regular and pro) become great options (among others)


----------



## skeptic

spacequeen7 said:


> other then Aune T1 only Schiit Modi (one day) and with the right tube T1 sounds great (best three tube combo 6922 Amperex or Mullard [ Aune] +Haltron GEC/unknown 12AU7 [Crack] ) ,I already ordered some film replacements and pot
> 
> I should be getting this in few days (I have few very nice 6SN7 tubes..can't wait to try them on Crack  )
> http://www.ebay.com/itm/1pc-convert-tube-socket-12AU7-12AX7-to-6SN7-6SL7-/321333602172?pt=US_Home_Audio_Amplifiers_Preamps&hash=item4ad0f9a77c
> ...


 
  
 Sad to say that's one of the 2 adapters I bought that had noise issues (in fact, it was the worse of the two by a huge margin).  It was also among the 4 adam bought that _all _had noise issues.  Hope you win the adapter lottery like punit reportedly did - if indeed, the adapter is even the real issue.  As you guys may have noted, PB has posted several times, here and on the BH boards, that modding the circuit and using a separate wall wart to provide DC to the 6sn7 heaters is the recommended way to run that tube type quietly.
  
 I have far more 12au7's and 12bh7's than 6sn7's and ultimately decided to abandon this fool's errand and to leave my amp as is.  Trace levels of bitterness remain.


----------



## spacequeen7

getting little exited about upcoming weekend 
	

	
	
		
		

		
			





,..still waiting for Blue Velvet


----------



## MattTCG

^^ You bought some new scented candles?


----------



## spacequeen7

this are some C4 my man


----------



## MattTCG

Nice caps! I did some extra finish work on the base today. I'm calling it finished.


----------



## spacequeen7

^^ that looks nice ..red oak ?,I was looking at some wood samples ,still can't decide


----------



## MattTCG

It's walnut. The light makes it look different.


----------



## JamieMcC

spacequeen7 said:


> getting little exited about upcoming weekend
> 
> 
> 
> ...


 
  
 Nice Caps welcome to the club.
  


matttcg said:


> Nice caps! I did some extra finish work on the base today. I'm calling it finished.


 
  
 Your base is looking very nice Matt, how are you thinking of finishing the top plate?
  
 I am in the middle of making a case for my BH Quickie the top plate is the same dimension as the Cracks. I decided to make it a little deeper than the Cracks enclosure just in case my cap addiction takes a turn for the worse. I can always cut it down later if I want to make it smaller. That way I have the option of swapping the bases around.


----------



## caracara08

matttcg said:


> It's walnut. The light makes it look different.


 
  
 beautiful base matt!


----------



## Aussiejuggalo

So from reading what you guys have said you all seem to advise against installing the speedball during the initial build?

Also what kinda mods do you guys do, I see a lot of you changing the caps and tubes, is that all you do? Just curious


----------



## Loquah

aussiejuggalo said:


> So from reading what you guys have said you all seem to advise against installing the speedball during the initial build?
> 
> Also what kinda mods do you guys do, I see a lot of you changing the caps and tubes, is that all you do? Just curious


 
  
 There are a couple of lists around with the range of mods in order of impact. Speedball is always the first on the list, but after that the common mods are:

Tubes
Upgraded volume pots / attenuators
Capacitors (power, bypass, etc.)
Upgraded RCA terminals and signal cables
  
 I'm not recommending any of these by listing them though and would say that it's best to start stock and listen for a while then install Speedball. Tube rolling is fun at anytime, but has less impact than the Speedball. After that you'll have a really good sense of what you might want to do next (if anything)


----------



## Sonido

Of course you can also feed it in with the Quickie like I'm doing.


----------



## Aussiejuggalo

loquah said:


> There are a couple of lists around with the range of mods in order of impact. Speedball is always the first on the list, but after that the common mods are:
> 
> Tubes
> Upgraded volume pots / attenuators
> ...




Ah cool, these Bottlehead products are some of the most flexible products I've ever seen :eek:

Gonna have to get me one of these when money permits 



sonido said:


> Of course you can also feed it in with the Quickie like I'm doing.




Well hey... I do need a preamp


----------



## Loquah

aussiejuggalo said:


> Ah cool, these Bottlehead products are some of the most flexible products I've ever seen
> 
> 
> 
> ...


 
  
 The Quickie is great!! Highly recommended!


----------



## Aussiejuggalo

loquah said:


> The Quickie is great!! Highly recommended!




How many damn batterys does it need :eek: lol

Looks nice tho and damn cheap


----------



## Sonido

I have to say most audio improvement per dollar so far in this audiophile journey for me has been the $135 for the Quickie + PJCCS. Actually, it's probably the $35 in the PJCCS upgrade itself, but that's not a standalone gear. I found that upgrade to really make a difference sonically, especially in the bass.


----------



## Loquah

sonido said:


> I have to say most audio improvement per dollar so far in this audiophile journey for me has been the $135 for the Quickie + PJCCS. Actually, it's probably the $35 in the PJCCS upgrade itself, but that's not a standalone gear. I found that upgrade to really make a difference sonically, especially in the bass.


 
  
 Yeah the Quickie is nice, but not amazing in stock form, but it's incredible value with the PJCCS tacked on!


----------



## Aussiejuggalo

Probably gonna get flammed hard for this , if I got the Crack and Quickie and used my STX as a DAC... would it be a waste for the Crack and Quickie?

I'd only be using my STX coz I game so its 8 channel audio is a must lol


----------



## Sonido

aussiejuggalo said:


> Probably gonna get flammed hard for this
> 
> 
> 
> ...


 
 Probably not. While the Crack (and Quickie) is great in musicality, it's not the last word in picking out all those fine details. I even found the $120 Vali to be better at that. I don't think the DAC is as important for this setup.


----------



## Loquah

sonido said:


> Probably not. While the Crack (and Quickie) is great in musicality, it's not the last word in picking out all those fine details. I even found the $120 Vali to be better at that. I don't think the DAC is as important for this setup.


 
  
 +1 STX should be fine (not saying it's the perfect setup, but if it meets your gaming needs it'll be a fine all-rounder)


----------



## mordicai

Anyone know if this is the right way to go with the Crack?  Valab 23-Stepped Attenuator Volume Control 100K --- stereo log type; 2 channels


----------



## Loquah

mordicai said:


> Anyone know if this is the right way to go with the Crack?  Valab 23-Stepped Attenuator Volume Control 100K --- stereo log type; 2 channels


 
  
 Sounds right to me


----------



## mordicai

Thanks Loquah


----------



## Aussiejuggalo

sonido said:


> Probably not. While the Crack (and Quickie) is great in musicality, it's not the last word in picking out all those fine details. I even found the $120 Vali to be better at that. I don't think the DAC is as important for this setup.




Lol should buy the Quickie for preamp, Crack for music and Soloist SL for gaming  But thats probably a bit over the top 



loquah said:


> +1 STX should be fine (not saying it's the perfect setup, but if it meets your gaming needs it'll be a fine all-rounder)




Are there any external DACs that can do 8 channel audio with normal stereo headphones or is it only internal sound cards that can?


----------



## Armaegis

There are pro audio dacs which can do 8+ channels, but you're still only going to get 2 in stereo unless you're mixing the channels together.


----------



## Aussiejuggalo

armaegis said:


> There are pro audio dacs which can do 8+ channels, but you're still only going to get 2 in stereo unless you're mixing the channels together.




Thought so, the STX does kind of a virtual mix via software or something lol


----------



## dxanex

sonido said:


> I have to say most audio improvement per dollar so far in this audiophile journey for me has been the $135 for the Quickie + PJCCS. Actually, it's probably the $35 in the PJCCS upgrade itself, but that's not a standalone gear. I found that upgrade to really make a difference sonically, especially in the bass.


 
  
 Hey Sonido, how long do the batteries typically last in the Quickie? Have you needed to replace them often?
  
 Anyone else tried it with the HD 650/Crack combo with good results? I'm curious, and it's cheap enough that I'm willing to give it a whirl. Hell, it's cheaper than many premium tubes!


----------



## MattTCG

dxanex said:


> Hey Sonido, how long do the batteries typically last in the Quickie? Have you needed to replace them often?
> 
> Anyone else tried it with the HD 650/Crack combo with good results? I'm curious, and it's cheap enough that I'm willing to give it a whirl. Hell, it's cheaper than many premium tubes!


 
  
 I'm curious about the quickie also. I guess I'll head over to BH and read through the forums.


----------



## Sonido

dxanex said:


> Hey Sonido, how long do the batteries typically last in the Quickie? Have you needed to replace them often?
> 
> Anyone else tried it with the HD 650/Crack combo with good results? I'm curious, and it's cheap enough that I'm willing to give it a whirl. Hell, it's cheaper than many premium tubes!



About a month and half at 4 hours of usage a day on alkaline batteries. I bought batteries from Woot at $40 for 6 sets (24 9V, 12 D cells).


----------



## Doc B.

That sounds pretty typical of battery life. The math says 200 hours for a stock Quickie (and a bit less for one with PJCCS installed), based upon the Ah rating of typical alkaline 9Vs and D cells. But the reality is that a lot of batteries don't last quite as long as the manufacturer publishes and users seem to get more like 150 hours out of a set on average.


----------



## olegausany

loquah said:


> diaboliqu3 said:
> 
> 
> > Finally! Someone with Aune T1 and Crack. I use 6DJ8 single leg... So, what else DAC you compared with? Are you saying better DAC is the same with Aune T1? My Crack+balls will shipped to me next week. And I can't wait it anymore...
> ...

Never tried NFB5.2 or X-Sabre but if you want neutral DAC I would recommend Arcam irDac which is way cheaper than X-Sabre and pairs great with SEX and Decware CSP3


----------



## skeptic

FWIW - based on measurements I've seen, and assuming aune uses the same usb implementation in the t1 as in the x1, it looks like jitter measurements may be less than ideal.  See comparison here to one of the $50 generic "breeze audio" cm6331a usb converters off ebay.  http://archimago.blogspot.com/2013/03/measurements-adaptive-aune-x1.html  Hard to say how audible this really is, if at all, but it is clear that the aune is not up to the level of current gen budget usb solutions.


----------



## Klots

Hi! I own Sennheiser HD700 headphones and I ordered my Crack yesterday (woohoo! 
	

	
	
		
		

		
			





). Now im looking for a dac. Im thinking about two dacs - Aune T1 and Schiit Modi. Basically they are both the same price for me (shipping + customs). I know that Aune T1 also has an amp section inside, but its more about which one goes better with Crack. Any opinions welcome


----------



## UmustBKidn

armaegis said:


> 1) clear two big spaces, one to do the actual work, the other to lay out all your components (using the sticky bubble wrap is great for this so they don't roll around
> 2) read through the crack manual, lay out all the components in a logical order, cut/strip/tin wires ahead of time if you want to (lots of prep time, but makes life easier)
> 3) read through the speedball manual, lay stuff out, etc. you can actually populate the boards as a separate project so feel free
> 3b) note the four resistors which you'll be replacing in the crack, and remove or mark them from step 2
> ...


 
  
 If I may, I would suggest adding one bullet:
  
 0) Subscribe to the Crack thread on head-fi, for about 3 months, before you buy your kit. You'll learn a crapton of useful stuff.


----------



## mordicai

I bought a Emotiva DC- 1 to go with my Crack and HD600. Absolutely fabulous DAc. $499


----------



## UmustBKidn

lokesen said:


>


 
  


 Now that, is flat out beautiful.


----------



## spacequeen7

I don't know what to make out of it ...I recently noticed resonance coming through my right channel (there is some in the left but not as much),for example when the unit is ON and I have nothing playing any tapping on the base or aluminium plate will travel through left channel ,it's more of a micro phonic sound ...what gives ???
 I've tried  changing tubes ,headphones and it's not going away ,I was about to swap some caps but this have to be addressed first ,any help ?


----------



## Doc B.

90% of the time microphony is from the tubes. My solution to a ringing sound when tapping on the tube is - you guessed it - stop tapping on the tube. But if it is not a tube, start tapping on other parts to see if you can isolate it. The next most likely candidiate is a cap. But that doesn't happen very often. If the sound does not go away when you change tubes, it's most likely you simply have more than one microphonic tube. Pretty much all tubes are microphonic to some degree. It's a matter of finding one that you feel has a low enough level to be acceptable to you. When you aren't tapping on it.


----------



## spacequeen7

doc b. said:


> 90% of the time microphony is from the tubes. My solution to a ringing sound when tapping on the tube is - you guessed it - stop tapping on the tube. But if it is not a tube, start tapping on other parts to see if you can isolate it. The next most likely candidiate is a cap. But that doesn't happen very often. If the sound does not go away when you change tubes, it's most likely you simply have more than one microphonic tube. Pretty much all tubes are microphonic to some degree. It's a matter of finding one that you feel has a low enough level to be acceptable to you. When you aren't tapping on it.


 


> for example when the unit is ON and I have nothing playing any tapping on the base or aluminium plate


 
 it's not the tube I'm tapping on ,noise is most present when tapping next to headphone jack port
 EDIT; I just swapped power to my DV336SE and it's dead silent


----------



## Tonequest

Hi.
 I'm actually hesitating between the S.E.X and Crack kits... I have 150ohms orthodynamic headphones and Kanto iPair 5 active speakers. Has anyone any recommendations to make? What DAC to get would be the next brainstorming step... Thanks!


----------



## Zashoomin

tonequest said:


> Hi.
> I'm actually hesitating between the S.E.X and Crack kits... I have 150ohms orthodynamic headphones and Kanto iPair 5 active speakers. Has anyone any recommendations to make? What DAC to get would be the next brainstorming step... Thanks!


 
 Hi to you as well.  I personally think that you should go for the SEX. Since it looks likes the Kanto speakers are active there is no need to hook them up to any amp.  From what I think I know about the speakers just hook them up via usb to your computer or hook them up to your dac.  The headphones, though your orthos might be 150ohms, I don't think that the crack will put out enough current for them.  
  
 As for your dac I have no idea what your budget is so you got to give me a little something because there are 5 million dacs out there.


----------



## Loquah

zashoomin said:


> Hi to you as well.  I personally think that you should go for the SEX. Since it looks likes the Kanto speakers are active there is no need to hook them up to any amp.  From what I think I know about the speakers just hook them up via usb to your computer or hook them up to your dac.  The headphones, though your orthos might be 150ohms, I don't think that the crack will put out enough current for them.
> 
> As for your dac I have no idea what your budget is so you got to give me a little something because there are 5 million dacs out there.


 
  
 +1 for the S.E.X. I don't know about the speakers, but if they don't have built in volume controls, you might also want a Quickie...


----------



## SaddleSC

I am very excited to receive my BHC kit. I ordered back on Feb 4 and it looks like the updated Delivery Status page shows that they fulfilled all orders placed through Feb 2. So...it looks like a few more weeks wait for me, but I am sure that it will be well worth it. I am very excited to pair it with my HD650s


----------



## calipilot227

klots said:


> Hi! I own Sennheiser HD700 headphones and I ordered my Crack yesterday (woohoo!
> 
> 
> 
> ...


 
  
 I use the Modi with mine. I'm not even sure the Aune has a line-out from the DAC section (I could be wrong). The Bifrost is also worth considering, the Crack is definitely up to the task.


----------



## mordicai

tonequest said:


> Hi.
> I'm actually hesitating between the S.E.X and Crack kits... I have 150ohms orthodynamic headphones and Kanto iPair 5 active speakers. Has anyone any recommendations to make? What DAC to get would be the next brainstorming step... Thanks!


 
 I using a Crack with HD 600 headphones, but I also have Mackie active monitors. I went with an Emotiva DC-1 for the Dac. The Emotiva has XLR out connections to the speakers through   a very nice built in preamp. Emotiva has a 30 day " no questions asked" return policy. I've been a happy camper with this set up now for a couple of months'


----------



## hodgjy

mordicai said:


> I using a Crack with HD 600 headphones, but I also have Mackie active monitors. I went with an Emotiva DC-1 for the Dac. The Emotiva has XLR out connections to the speakers through   a very nice built in preamp. Emotiva has a 30 day " no questions asked" return policy. I've been a happy camper with this set up now for a couple of months'


 
 You should write a review about the DC-1.  I'd love to read your thoughts on it.


----------



## mordicai

Jay, I was turned on to the Emotiva through a comprehensive review of about 13 dacs conducted by a Head Fi member about two months ago. The Emotiva was the cheapest (499)  and the high end was about 2,000. The reviewer was an experienced audiophile and was looking for a new dac for himself. The tests ran for about two weeks and were documented many time each day with comments by others. The Thread ran many pages 50,60? I don't remember. I was a great resource for all of us looking for a new DAC. The upshot was, that he found the Emotiva sounded just as good as the 1,000 and 2,000 dollar DACs. He eventually bought a $1,200  Yulong D8 Dac because it was DSD capable, but rated the Evotiva #2, and said that the Emotiva and the Yulong sounded the same as a DAC. The thread was eventually locked by those who are the Lockers, and I have been unable to retrieve it with the search engine. My feeling is that it has disappeared down a deep hole somewhere because it is not in the best interests of this sites advertisers.  This is the best review I can provide you.


----------



## ben_r_

mordicai said:


> Jay, I was turned on to the Emotiva through a comprehensive review of about 13 dacs conducted by a Head Fi member about two months ago. The Emotiva was the cheapest (499)  and the high end was about 2,000. The reviewer was an experienced audiophile and was looking for a new dac for himself. The tests ran for about two weeks and were documented many time each day with comments by others. The Thread ran many pages 50,60? I don't remember. I was a great resource for all of us looking for a new DAC. The upshot was, that he found the Emotiva sounded just as good as the 1,000 and 2,000 dollar DACs. He eventually bought a $1,200  Yulong D8 Dac because it was DSD capable, but rated the Evotiva #2, and said that the Emotiva and the Yulong sounded the same as a DAC. The thread was eventually locked by those who are the Lockers, and I have been unable to retrieve it with the search engine. My feeling is that it has disappeared down a deep hole somewhere because it is not in the best interests of this sites advertisers.  This is the best review I can provide you.


 

 What was the model number of the Emotiva? Got a link to the thread youre referring to?


----------



## mordicai

It is a Emotiva D-1 Stealth Dac  I am unable to locate the link. Perhaps others who were involved in the thread can provide it to you. There was a large group of Headfiers involved.


----------



## mordicai

http://www.head-fi.org/t/689783/december-2013-mid-level-dac-comparison/855
  
 DAC REVIEW


----------



## ben_r_

mordicai said:


> It is a Emotiva D-1 Stealth Dac  I am unable to locate the link. Perhaps others who were involved in the thread can provide it to you. There was a large group of Headfiers involved.


 

 Ah, the DC-1 you mean? Reminds me of this thread: LINK


----------



## mordicai

No .That is not the correct link This is: http://www.head-fi.org/t/689783/december-2013-mid-level-dac-comparison/855


----------



## Sonido

I have the DC-1 as well and to be honest, not too much different than Modi. Of course this is through my Crack setup. When my Questyle amp arrives, I'll be able to compare more accurately. I got the DC-1 for potential balance use.


----------



## Klots

calipilot227 said:


> I use the Modi with mine. I'm not even sure the Aune has a line-out from the DAC section (I could be wrong). The Bifrost is also worth considering, the Crack is definitely up to the task.


 
 Sorry, I forgot to mention my budget. Im aiming for max 200$ (including shipping) outside Europe or 250$ (including shipping) from Europe. So Bifrost is over my budget (with usb its 449$).


----------



## diaBoliQu3

My Crack got few missing parts and loose RCA. Sad... Project, delayed again... Why oh why... And loud pop sound during start up, single channel only. Bad tubes again? Oh my...
 - Missing resistors
 - Loose RCA
 - Bad tubes
  
 Delayed another one month.


----------



## Nic Rhodes

E-DAC is a good DAC (Ephiphany Audio in Europe) and known by many other names elsewhere
  
 http://epiphany-acoustics.co.uk/products-page/dacs/e-dac-24bit-miniature-usb-dac/
  
 currently on sale. Modi is also good, just behind E-DAC in my book but these two USB only inputs DACs are the ones to beat on a budget imho.


----------



## JamieMcC

Gave the Crack a try out in the enclosure I made for the Quickie. I need to let the coating harden up prior to flatting it back then a compound and wax polish to finish off with. Need to also order a Bottlehead badge to go on the front. I am please how its turned out
  

  
 It was a bit dark to take a pic indoors so I went outside to catch the last of the evenings sunshine.


----------



## skeptic

diaboliqu3 said:


> My Crack got few missing parts and loose RCA. Sad... Project, delayed again... Why oh why... And loud pop sound during start up, single channel only. Bad tubes again? Oh my...
> - Missing resistors
> - Loose RCA
> - Bad tubes
> ...


 
  
 I'm confused by this.  Did you power it up without having the correct resistors installed?  As noted in the instructions, this amp shouldn't be introduced to its power cord until after it passes the resistance checks.  Then you need to pass voltage checks before plugging in your phones....
  
 Can you give us some detail on how all this played out, and maybe we can lend a hand.  The parts you mentioned should all be easy enough to source without waiting a month....


----------



## skeptic

jamiemcc said:


> Gave the Crack a try out in the enclosure I made for the Quickie. I need to let the coating harden up prior to flatting it back then a compound and wax polish to finish off with. Need to also order a Bottlehead badge to go on the front.
> .....


 
  
 Nice work Jamie!  Gorgeous job bringing out the grain in that wood!


----------



## MattTCG

Great work Jamie!! I love the wood case. It would go great with my hp stand.


----------



## Loquah

skeptic said:


> Nice work Jamie!  Gorgeous job bringing out the grain in that wood!


 
  
 +1 Stunning, Jamie!


----------



## diaBoliQu3

skeptic said:


> I'm confused by this.  Did you power it up without having the correct resistors installed?  As noted in the instructions, this amp shouldn't be introduced to its power cord until after it passes the resistance checks.  Then you need to pass voltage checks before plugging in your phones....
> 
> Can you give us some detail on how all this played out, and maybe we can lend a hand.  The parts you mentioned should all be easy enough to source without waiting a month....


 
 I don't mind buying my self the missing parts since they aren't that expensive but I paid the same amount like other buyer too. What I mean is maybe they should improve the checking before sending out. But some haters would flame me of course. I already buy the missing resistors and change the RCA.
  
 If it's a bad tube, I think the easiest way for me to get is from BH it self which can take about one month shipped to me. That's excluding waiting time.
  
 Amp assembled by my friend, not by me. What do mean introduce power cord, pass resistance checks, pass voltage checks, then plug in?


----------



## bdr529

I was missing some of the LEDs in my kit back around Christmas time and they were really fast getting them out to me. Less than a week.

Jamie that base looks great.


----------



## FlySweep

It's been three weeks since I flipped on my BH Crack & 650.. the newborn had taken up most all my free time.. but I finally got a chance today.. and good GOD.. how I missed it! It almost felt like listening to the combo for the first time.. just supremely addictive.. the spaciousness, dynamics, and tonal richness remains so seductive! What a badass rig.. a marriage made in sonic heaven.


----------



## lextek

flysweep said:


> It's been three weeks since I flipped on my BH Crack & 650.. the newborn had taken up most all my free time.. but I finally got a chance today.. and good GOD.. how I missed it! It almost felt like listening to the combo for the first time.. just supremely addictive.. the spaciousness, dynamics, and tonal richness remains so seductive! What a badass rig.. a marriage made in sonic heaven.




I am always amazes after taking a little break from Crack. I've bern demoing a pair of LCD-Xs. Fantastic headphone. Too heavy and they feel like the are fallinf off my head. I put my HD600s and Crack combo on and am thrilled. Can't be beat.


----------



## NightFlight

lextek said:


> I am always amazes after taking a little break from Crack. I've bern demoing a pair of LCD-Xs. Fantastic headphone. Too heavy and they feel like the are fallinf off my head. I put my HD600s and Crack combo on and am thrilled. Can't be beat.




HD800?


----------



## Loquah

Or T1 perhaps?


----------



## JamieMcC

loquah said:


> Or T1 perhaps?


 

 +1, I am amazed daily at just how good my T1' s are sounding paired with my Crack in its current configuration. The HD650 are getting very little head time these days.


----------



## Loquah

jamiemcc said:


> +1, I am amazed daily at just how good my T1' s are sounding paired with my Crack in its current configuration. The HD650 are getting very little head time these days.


 
  
 That was exactly what happened for me too. These days, the HD650s are gone (missed, but gone) - the T1s are just such a great all-round can. Still looking forward to trying the HD800s for an extended period though...


----------



## JamieMcC

loquah said:


> That was exactly what happened for me too. These days, the HD650s are gone (missed, but gone) - the T1s are just such a great all-round can. Still looking forward to trying the HD800s for an extended period though...


 

 lol  pondering over the HD800s here also. Hard to justify having both at the moment, if only my other half didn't like the HD650's so much...


----------



## mordicai

I hate to read these postings. I am so happy with my 600. I don't want to hear about some 1300 headphone that is much better and that I can't afford.  What is it about the T1 that you guys love so much over your faithful Sennheisers?


----------



## MattTCG

^^ Don't worry too much. The 600 and 650 both are more pleasing to my ears on the crack than the t1. We all have our preferences about sound.


----------



## Loquah

mordicai said:


> I hate to read these postings. I am so happy with my 600. I don't want to hear about some 1300 headphone that is much better and that I can't afford.  What is it about the T1 that you guys love so much over your faithful Sennheisers?


 
  
 I enjoy the extra air and detail that the T1s provide, but that's compared to the HD650, not the HD600 which I haven't spent significant time with.
  


matttcg said:


> ^^ Don't worry too much. The 600 and 650 both are more pleasing to my ears on the crack than the t1. We all have our preferences about sound.


 
  
 Agree. There's no guarantee that you'd enjoy the T1's more than the HD600s, @mordicai. The T1s are excellent, but they are different too and that's not always a good thing. I would always recommend trying other phones like the T1s, HD800s, etc. but wouldn't suggest that they're always a better option because we're all different.


----------



## mordicai

Well Id love to try the T1s and the magniplaners, but that's a hard thing to do without buying them. Hopefully I'm be able to attend the next headfiers meet here in San Diego and have the opportunity. I find the 600 very smooth and an analog sound with my Crack. Very easy to listen to.  Too much detail in some of my 192 recordings turn me off a bit because they tend start sounding "digital". More open and airiy would be nice though.


----------



## Loquah

mordicai said:


> Well Id love to try the T1s and the magniplaners, but that's a hard thing to do without buying them. Hopefully I'm be able to attend the next headfiers meet here in San Diego and have the opportunity. I find the 600 very smooth and an analog sound with my Crack. Very easy to listen to.  Too much detail in some of my 192 recordings turn me off a bit because they tend start sounding "digital". More open and airiy would be nice though.


 
  
 Do try the T1s if you ever get a chance. They're relatively warm despite the treble peak and the Crack helps to keep them sounding nice and smooth - not quite HD6x0 smoot, but still smooth.


----------



## palmfish

I dont have a lot of head time with the T1, but the impression I got is that it is a step up from the HD 600 and a step down from the HD 800. It has a pleasing neutralish signature like the HD 600 but with a beautiful, authoritative and articulate bass response. It is how the HD 700 should have sounded...lol.


----------



## diaBoliQu3

Between Senn HD 600 + Crack or Beyer DT 990 250 ohm pro, which one would you guys prefer?


----------



## palmfish

Between the HD 600 and ANY other headphone under $500, it's a no-brainer. Just get the HD 600 and be done with it. Really.


----------



## diaBoliQu3

palmfish said:


> Between the HD 600 and ANY other headphone under $500, it's a no-brainer. Just get the HD 600 and be done with it. Really.


 

 Already own HD 600, but $142 DT 990 kinda hard to reject. >_<


----------



## palmfish

diaboliqu3 said:


> Already own HD 600, but $142 DT 990 kinda hard to reject. >_<


 
  
 If you already own a Porsche Boxster, why do you care about a deal on a Miata?


----------



## Armaegis

Because some people liking having a garage full of cars?


----------



## olegausany

Maybe he enjoy piercing bright treble


----------



## diaBoliQu3

LoL. Make sense... No brainer to waste money since I already own a good can. Thank you for loving saving me.


----------



## grrraymond

Afternoon, gents. I've seen a 5998 Tung-Sol for £90 but it's described as 'Grade 1', not NOS. Can anyone tell me what this means?
  
 90 quid seems reasonably steep but then I've not seen them a hell of a lot cheaper anywhere else, and in fact I've only seen pairs on eBay, which I don't need/want.
  
 I've only rolled in a Mullard ECC82 so far and it did make a difference, I was pleasantly surprised to find. Still yet to do the Speedball upgrade, partly because I'm so happy with how it sounds right now and partly because I know I'll need to buy a better soldering kit for when I do. I've heard the TS 5998 is kind of the holy grail of Crack tubes so if not now, then when?
  
 I don't want to get it if it's not the right thing, though. Apologies for n00bish question, I'm well out of my depth with tubes.


----------



## JamieMcC

grrraymond said:


> Afternoon, gents. I've seen a 5998 Tung-Sol for £90 but it's described as 'Grade 1', not NOS. Can anyone tell me what this means?
> 
> 90 quid seems reasonably steep but then I've not seen them a hell of a lot cheaper anywhere else, and in fact I've only seen pairs on eBay, which I don't need/want.
> 
> ...


 
  
 Garry that's silly money for a 5998 especially if its not tested are you UK based?


----------



## mcandmar

Personally i would spend the money on a speedball upgrade instead.


----------



## JamieMcC

mcandmar said:


> Personally i would spend the money on a speedball upgrade instead.


 

 mcandmar yes that's a good suggestion.
  
 Also the Mullard 6080 comes up quiet often if you search via the "Europe" feature for around £10 used or NOS for £20 and I would not like to do a blind test between it and a 5998.


----------



## grrraymond

jamiemcc said:


> Garry that's silly money for a 5998 especially if its not tested are you UK based?


 
  
 Yeah, I'm in Liverpool. I've not managed to find anything cheaper despite lots of searching online.
  
 I'll have a look at the Mullard 6080 then. Thanks, Jamie.


----------



## JamieMcC

I am guessing you found the 5998 here they also have the GEC 6as7g listed. I have never used them and am not sure if they sell direct to the public.
  
 https://web211.secure-secure.co.uk/tube-and-valve-electronics.co.uk/wholesale/basket.asp


----------



## grrraymond

Thanks for the info about what's a reasonable price. I'll definitely check out the Mullard because I've seen a few around for £20-30 and I was pleasantly surprised by the ECC82, for the nominal price I paid.


----------



## Nic Rhodes

don't forget 5998 are rarely used in UK and was a US tubes, A1834 / 6AS7G GECs are a UK tube and rarely seen in US, so this will give you an idea where to buy each from. Mullard and GECs are excellent tubes. £90 should almost get you an A1834 / 6AS7G GEC (sent from Cyprus to UK), via ebay  If you bid on Mullard 6080s there might be interest from others but I got one for £1.20 the other day plus P and P.


----------



## JamieMcC

nic rhodes said:


> £90 should almost get you an A1834 / 6AS7G GEC (sent from Cyprus to UK), via ebay  If you bid on Mullard 6080s there might be interest from others but I got one for £1.20 the other day plus P and P


 
  
 lol I was bidding on the Mullard 6080 as well, first bidder, "You bid £1.00. The auction just ended at £1.20" I had meant to increase my bid but forgot all about it! Its good to know someone from the forum won it.


----------



## Nic Rhodes

are we gong to compete on those four GECs  ?


----------



## JamieMcC

sshhhh! they are on the watch list, I have not put a bid in I expect as a quad they might go a bit high for me


----------



## JamieMcC

Nic my tube purchasing funds are a little low after a winning a pair of GEC curved brown bases yesterday! So the field is all yours. PM me if you win and I would be interested if you have one going spare.
  
 Good luck!


----------



## Nic Rhodes

jamiemcc said:


> Nic my tube purchasing funds are a little low after a winning a pair of GEC curved brown bases yesterday! So the field is all yours. PM me if you win and I would be interested if you have one going spare.
> 
> Good luck!


 

  You were the one who out bid me then! lol I bid £81 and you won with £83! I won the Brimars from that seller, a rather nice ceramic based 6080 in that lot


----------



## JamieMcC

nic rhodes said:


> You were the one who out bid me then! lol I bid £81 and you won with £83! I won the Brimars from that seller, a rather nice ceramic based 6080 in that lot


 
  
 Nic that is twice you have pipped me at the post, and I was pressing the £6 bid now button when the time ran out lol..
  
 Did not win: Brimar 6080 pair of valves octal bases‏
  
 You bid £5.00. The auction just ended at £5.50
  
 Small world


----------



## mithrandir38

I'm happy to say I just picked up the Beyerdynamic T90's for my Crack, and man, they sing.  I've been more of a Sennheiser guy, listening to most of my music on my HD650's at home and the Momentums on the go.  I was never quite satisfied with the 650's.  None of that "veil" nonsense, I just never really dug the rolled-off sub bass, and there was a certain sweetness in the presence region missing from these phones for me.
  
 After reading many a review online for the various Beyer's I decided to pull the trigger on the  T90s for just $409.00 on ebay; man, am I glad I did!  The bass gave me what I felt was missing with the Senns: greater impact and depth.  The midrange is silky smooth and ultra detailed  Voices and instruments sound rich and natural with no stridency to speak of.
  
 The treble is just fantastic.  This is the biggest difference between the T90's and the 650's imo.  They way they've sculpted the treble, it seems to have an emphasis in the upper region: plenty of treble "air", but without harshness in the lower treble.  There's a tiny bit of sibilance here and there.  For instance, on U2's Achtung Baby, Bono's voice can be pretty raw at times because that's the way it was recorded and mixed.  Very little sibilance on the dozens of albums I've demoed.   From Master of Puppets to Taylor Dayne to Rush's Moving Pictures, everything is just smooth, detailed and airy.  Beyerdynamic has earned a new customer with these superb 'phones.  I've done extensive listens with the HD700's and the LCD-2's recently, and I have to say the T90's are not just the best value I've heard under $1000 bucks, but just simply one of the best headphones under $1000, period.  Highly recommended as a virtually perfect match with the Crack (mine is all stock in case you were wondering.  No speedball...yet).
  
 On a side note, I recently replaced the stock vintage tube in my Crack with a Genalex Gold Lion 12au7...Big mistake!  And yes the Genalex was burned in for about 50-60 hours.  Where the T90's sounded perfectly even and smooth before, they now sounded overly bright, slightly grainy in the highs, with less bass.  I just simply didn't enjoy them as much as with the original input tube.  I guess there's something to be said for the quality of those old NOS tubes after all...


----------



## mithrandir38

I'm happy to say I just picked up the Beyerdynamic T90's for my Crack, and man, they sing.  I've been more of a Sennheiser guy, listening to most of my music on my HD650's at home and the Momentums on the go.  I was never quite satisfied with the 650's.  None of that "veil" nonsense, I just never really dug the rolled-off sub bass, and there was a certain sweetness in the presence region missing from these phones for me.
  
 After reading many a review online for the various Beyer's I decided to pull the trigger on the  T90s for just $409.00 on ebay; man, am I glad I did!  The bass gave me what I felt was missing with the Senns: greater impact and depth.  The midrange is silky smooth and ultra detailed  Voices and instruments sound rich and natural with no stridency to speak of.
  
 The treble is just fantastic.  This is the biggest difference between the T90's and the 650's imo.  They way they've sculpted the treble, it seems to have an emphasis in the upper region: plenty of treble "air", but without harshness in the lower treble.  There's a tiny bit of sibilance here and there.  For instance, on U2's Achtung Baby, Bono's voice can be pretty raw at times because that's the way it was recorded and mixed.  Very little sibilance on the dozens of albums I've demoed.   From Master of Puppets to Taylor Dayne to Rush's Moving Pictures, everything is just smooth, detailed and airy.  Beyerdynamic has earned a new customer with these superb 'phones.  I've done extensive listens with the HD700's and the LCD-2's recently, and I have to say the T90's are not just the best value I've heard under $1000 bucks, but just simply one of the best headphones under $1000, period.  Highly recommended as a virtually perfect match with the Crack (mine is all stock in case you were wondering.  No speedball...yet).
  
 On a side note, I recently replaced the stock vintage tube in my Crack with a Genalex Gold Lion 12au7...Big mistake!  And yes the Genalex was burned in for about 50-60 hours.  Where the T90's sounded perfectly even and smooth before, they now sounded overly bright, slightly grainy in the highs, with less bass.  I just simply didn't enjoy them as much as with the original input tube.  I guess there's something to be said for the quality of those old NOS tubes after all...


----------



## mithrandir38

I'm happy to say I just picked up the Beyerdynamic T90's for my Crack, and man, they sing.  I've been more of a Sennheiser guy, listening to most of my music on my HD650's at home and the Momentums on the go.  I was never quite satisfied with the 650's.  None of that "veil" nonsense, I just never really dug the rolled-off sub bass, and there was a certain sweetness in the presence region missing from these phones for me.
  
 After reading many a review online for the various Beyer's I decided to pull the trigger on the  T90s for just $409.00 on ebay; man, am I glad I did!  The bass gave me what I felt was missing with the Senns: greater impact and depth.  The midrange is silky smooth and ultra detailed  Voices and instruments sound rich and natural with no stridency to speak of.
  
 The treble is just fantastic.  This is the biggest difference between the T90's and the 650's imo.  They way they've sculpted the treble, it seems to have an emphasis in the upper region: plenty of treble "air", but without harshness in the lower treble.  There's a tiny bit of sibilance here and there.  For instance, on U2's Achtung Baby, Bono's voice can be pretty raw at times because that's the way it was recorded and mixed.  Very little sibilance on the dozens of albums I've demoed.   From Master of Puppets to Taylor Dayne to Rush's Moving Pictures, everything is just smooth, detailed and airy.  Beyerdynamic has earned a new customer with these superb 'phones.  I've done extensive listens with the HD700's and the LCD-2's recently, and I have to say the T90's are not just the best value I've heard under $1000 bucks, but just simply one of the best headphones under $1000, period.  Highly recommended as a virtually perfect match with the Crack (mine is all stock in case you were wondering.  No speedball...yet).
  
 On a side note, I recently replaced the stock vintage tube in my Crack with a Genalex Gold Lion 12au7...Big mistake!  And yes the Genalex was burned in for about 50-60 hours.  Where the T90's sounded perfectly even and smooth before, they now sounded overly bright, slightly grainy in the highs, with less bass.  I just simply didn't enjoy them as much as with the original input tube.  I guess there's something to be said for the quality of those old NOS tubes after all...


----------



## mithrandir38

whoops, double post!


----------



## punit

mithrandir38 said:


> On a side note, I recently replaced the stock vintage tube in my Crack with a Genalex Gold Lion 12au7...Big mistake!  And yes the Genalex was burned in for about 50-60 hours.  Where the T90's sounded perfectly even and smooth before, they now sounded overly bright, slightly grainy in the highs, with less bass.  I just simply didn't enjoy them as much as with the original input tube.  I guess there's something to be said for the quality of those old NOS tubes after all...


 
 The TS 5998 will be the icing on the cake for the T90's. The Btl Crack (with Spd Ball) + TS 5998 is the best sound I have heard from the T90's.


----------



## mithrandir38

punit said:


> The TS 5998 will be the icing on the cake for the T90's. The Btl Crack (with Spd Ball) + TS 5998 is the best sound I have heard from the T90's.


 

 Thx for the tip, I'll have to look for it on ebay


----------



## MattTCG

The TS 5998 seems to be THE tube for the crack. It's the best I've heard anyway...


----------



## punit

IMHO GEC 6AS7G is THE tube for the Crack, beats the TS 5998 in clarity (but for T90's which are a bit bright TS 5998 is perfect match).


----------



## UmustBKidn

jamiemcc said:


> Nic my tube purchasing funds are a little low after a winning a pair of GEC curved brown bases yesterday! So the field is all yours. PM me if you win and I would be interested if you have one going spare.
> 
> Good luck!


 
  
 This must be the UK version of ebay, then?
  
 I wonder if I can manage to sneak over there and bid on something...


----------



## JamieMcC

When searching on ebay in the uk
  
 A standard ebay search in the UK will give results for UK and also matches from sellers in other countries who pay extra to have International listings.
  
 search's can also be filtered to 
  
 UK only, Europe, Worldwide.
  
 I expect other countries have something similar. By the way I can log into USA ebay.com with my ebay.uk details.
  
 Generally the extra shipping + import and handling fees from the US don't make it attractive especially if ordering from a retail supplier but there are exceptions.


----------



## JamieMcC

The Bottlehead forum is down again they have not had any luck restoring all the pictures which became corrupted. It must be very frustrating. 
  
  
 I find the new product page a is a nice improvement it looks very slick and polished with a good balance of info and specs about each product.


----------



## MattTCG

^^ It's not easy to make that kind of wholesale change but I'm sure that Doc and the boys will sort it out. I love their new look. 
  
 It would be wonderful if headfi would adopt a similar color scheme. As much time as I spend on HF, I'd certainly appreciate the relaxing look.


----------



## punit

nic rhodes said:


> are we gong to compete on those four GECs  ?


 
  
  


jamiemcc said:


> Nic my tube purchasing funds are a little low after a winning a pair of GEC curved brown bases yesterday! So the field is all yours. PM me if you win and I would be interested if you have one going spare.
> 
> Good luck!


 
  
   
 

 I'd be interested too


----------



## glunteer

Hey guys !
  
 I'll buy Crack to use with my ODAC> HD 600, and I was wondering if the speedball make much difference?


----------



## MattTCG

glunteer said:


> Hey guys !
> 
> I'll buy Crack to use with my ODAC> HD 600, and I was wondering if the speedball make much difference?


 
  
 Yes, it makes a big difference. Maybe the biggest difference of all upgrades. It should be considered at the very top of the list if you want to improve the quality of the amp.


----------



## glunteer

matttcg said:


> Yes, it makes a big difference. Maybe the biggest difference of all upgrades. It should be considered at the very top of the list if you want to improve the quality of the amp.


 
 matt thanks for the reply ... I'm afraid to import a crack, the box is too big and I have to pay a lot of taxes here in Brazil 
	

	
	
		
		

		
		
	


	



   

    
 with speedball will be even more expensive, I'll have to think yet ...

  
 Thanks


----------



## mcandmar

jamiemcc said:


> When searching on ebay in the uk
> 
> A standard ebay search in the UK will give results for UK and also matches from sellers in other countries who pay extra to have International listings.
> 
> ...


 
  
 Just note you wont see all items for sale, only items that have a postage price populated specifically for your location.  For example you can login to ebay.com and find items listed with "worldwide" shipping, yet those items wont show up through ebay.co.uk.   Same is also true for European variants, ebay.de, .fr, .it, .es, .be, .ch etc.  You can find some real gems on those sites with a little time searching.   ....probably should have kept that one to myself.


----------



## T Bone

jamiemcc said:


> The Bottlehead forum is down again they have not had any luck restoring all the pictures which became corrupted. It must be very frustrating.


 
  
 It's driving me nuts.  I've tried intermittently over the last several days to browse the gallery without much luck.  I am really interested in alternate cases.  I want to start one of their DIY kits - but in something that will match the my other gear.


----------



## Zashoomin

t bone said:


> It's driving me nuts.  I've tried intermittently over the last several days to browse the gallery without much luck.  I am really interested in alternate cases.  I want to start one of their DIY kits - but in something that will match the my other gear.


 
 Well I am not sure what you have but you can stain the wood the color that you want and you can also paint the top plate and bell the color that you want as well.


----------



## ben_r_

t bone said:


> It's driving me nuts.  I've tried intermittently over the last several days to browse the gallery without much luck.  I am really interested in alternate cases.  I want to start one of their DIY kits - but in something that will match the my other gear.


 

 What color/style are you looking for exactly?


----------



## T Bone

I was trying to troll the gallery for inspiration.  
 I've seen a couple of builds in the past that featured all-metal cabinets.  If I build one, I think I'd like to try an anodized or enameled case to match my banana yellow Pro-Ject Debut Carbon turntable.  ....it's not for everyone, but it certainly is eye catching.


----------



## mithrandir38

t bone said:


> I was trying to troll the gallery for inspiration.
> I've seen a couple of builds in the past that featured all-metal cabinets.  If I build one, I think I'd like to try an anodized or enameled case to match my banana yellow Pro-Ject Debut Carbon turntable.  ....it's not for everyone, but it certainly is eye catching.


 I just ordered my carbon in blue. Can't wait! Also ordered a Cambridge Audio Azur 551p phono preamp


----------



## T Bone

I also have ideas for "hot-rodding" the fasteners on the top plate with chromed button or socket head sockets caps.  If I can get them small enough. 
 It doesn't do a thing for the sound - a purely cosmetic upgrade.


----------



## T Bone

mithrandir38 said:


> I just ordered my carbon in blue. Can't wait! Also ordered a Cambridge Audio Azur 551p phono preamp


 
 I don't have a big vinyl collection yet - I grew up on CD's.  I got the debut carbon as an xmas gift and I'm loving it.  I've had lots of phone digging through the used albums at the record store and finding the occasional gem.
 I'm using a Bellari VP 530 pre amp right now - it's got to go.  I like the fact that I can drive my headphones through it and I wanted to tinker with the USB output.  ...it's neat (and cheap) - but certainly not an audiophile piece gear. I've been eyeballing the Eros pre-amp kit as an upgrade.  _(must remind myself to do only one project at a time!)_


----------



## JamieMcC

Part of me hopes some ones head will be on the chopping block for the loss of what is a valuable pictorial resource for anyone interested in building a Bottlehead amp. 
  
 My more rational side says its just a few pictures and with a little time they will be replaced by new ones. However I sincerely hope there is still a chance they can get some of them back.


----------



## mithrandir38

t bone said:


> I don't have a big vinyl collection yet - I grew up on CD's.  I got the debut carbon as an xmas gift and I'm loving it.  I've had lots of phone digging through the used albums at the record store and finding the occasional gem.
> I'm using a Bellari VP 530 pre amp right now - it's got to go.  I like the fact that I can drive my headphones through it and I wanted to tinker with the USB output.  ...it's neat (and cheap) - but certainly not an audiophile piece gear. I've been eyeballing the Eros pre-amp kit as an upgrade.  _(must remind myself to do only one project at a time!)_


 I wanted the Bellari, but it was more expensive. I'm interested in the Reduction as well


----------



## JamieMcC

t bone said:


> I was trying to troll the gallery for inspiration.
> I've seen a couple of builds in the past that featured all-metal cabinets.  If I build one, I think I'd like to try an anodized or enameled case to match my banana yellow Pro-Ject Debut Carbon turntable.  ....it's not for everyone, but it certainly is eye catching.


 
  
 Why not just paint the alloy plate and wood enclosure. Some wood sealer and some automotive highbuild primer and you would be good to go with a top coat, the choice of automotive paints is endless and normally easy to find local and inexpensive for base colors.
  
 Spray it all yellow then tape out a chequered pattern and spray black over the top you could even do the turn table at the same time so they matched.  Just throwing an idea out there.


----------



## T Bone

See - that's why I've been bummed that the images on the bottlehead forum are messed up.  I've been trying to troll their forum for case mod ideas - but you can't really do that right now.  
 I hadn't considered sealing the wood and painting it.  It's a good idea though.


----------



## Zashoomin

t bone said:


> See - that's why I've been bummed that the images on the bottlehead forum are messed up.  I've been trying to troll their forum for case mod ideas - but you can't really do that right now.
> I hadn't considered sealing the wood and painting it.  It's a good idea though.


 
 I suggest you get a yellow top plate with a black bell and then stain the wood with some ebony stain.  To finish it off put some varnish or poly or whatever to get some gloss on the wood.


----------



## skeptic

punit said:


> IMHO GEC 6AS7G is THE tube for the Crack, beats the TS 5998 in clarity (but for T90's which are a bit bright TS 5998 is perfect match).




I'd say just the opposite. As compared to ordinary 6as7(g)s and 6080s, the 5998, 7236 and 7802 have higher gain and higher transconductance, the latter of which lowers an OTL headamp's output impedance. As one would expect, this tends to make the sound a little brighter, faster and bass a little tighter. Ordinary 6as7g's and 6080's, including the much hyped GECs, raise output impedance and are a little be more mellow on the top end and a little fatter at the bottom end due to minor bass bloom. As described in an article on Pete Millet's site (http://www.pmillett.com/Wheatfield/rolling.pdf , see bottom of page 2), "The 5998, 7236, and 6528 have different characteristics than the 6AS7 and 6080 tubes, which lower the output impedance of the HA-2. The resulting sound tends to be brighter and faster than the stock 6080. Conversely, a good old-stock 6AS7G tube can fatten the bass and give an even more "tubey" sound."

I've made similar comments in the 650 thread from time to time and think they bear repeating here. The GEC, which I do own (purchased back when they were still relatively cheap), is simply a very nice, refined 6as7g equivalent. It looks cool, but honestly, I have a couple of $10 mil spec 6080's that arguably sound just as good. The hype surrounding this tube has reached the point of absurdity. Even skylab, who was head-fi's original proponent of the GEC tubes, has urged other head-fiers not to buy them at their present inflated prices - unless of course, you are buying for the sake of collecting, and not because you expect $200+ worth of improvement to your sound quality. The only poster who has repeatedly made statements to the contrary (no one in this thread) recently admitted having purchased a number of the GEC tubes on the cheap and then, after prolifically posting about them as the be all end all, selling them on head-fi at current ebay prices. The mods ultimately put a stop to it, but anyone considering buying a GEC tube should know the full story and approach that decision with due caution.


----------



## punit

I made the statement based on my own experience with the Bttl Hd Crak + HD 800 / T1 / T90. I have the following tubes :
  
 TS 5998
 GEC 6080
 WE 421A
 GE 6080
 GEC 6AS7G
 Mullard 6080
  
 But yes, the GEC 6AS7G is not the best value in that list from a SQ / Price perspective. It is only for crazy / obsessive people who chase SQ with disregard to price value.
	

	
	
		
		

		
			



*IMHO*.
  
 THe GEC synergy with HD 800 is 
	

	
	
		
		

		
		
	


	




. Was listening to HD 800 with the GEC + TS 6SN7 combo on the Crack last night, time flew & before I realised it was 2 pm & I got only 5 hours of sleep. Feeling so F@#%*d at work right now. Damm this hobby


----------



## skeptic

Guess we hear it differently, but I do think the science bears considering. All four of my 5998s, my 7236, and my 7802 (quite rare, and the highest transconductance), are brighter and tighter in the bottom end than my lower transconductance/higher impedance GEC 6as7g and my pile of various 6080s. Agree that the GEC is nice and transparent. I just find its appearance and price point to be far more remarkable than its sonics with my hd800s, 650s and dt880s. This has held true for me over the course of three plus years with my crack and irrespective of various mods along the way. I reach for lower transconductance tubes to tame aggressive trebles.


----------



## punit

Maybe the difference in opinion is because we prefer different sound signatures ? I see that you like the HD 650, but I sold it within a month as I found that it made music too lifeless / dead / boring for me, it was too dark for my taste.
  
 But I didn't have the Crack when I had the HD 650, maybe I would have liked them if I tried the with the Crack.


----------



## JamieMcC

The TS 5998 and E80cc are my Cracks daily drive. I save the GEC and Osram tubes (they are the same) for premium listening session when the house is quiet and I am able to relax and just focus on the music.
  
 I also feel the GEC is more refined in the mids, upper mids and treble. Though I really only use it for one genre of music if you like artists like Eva Cassidy, The Wailin Jennys, Cara Dillon, Simon & Garfunkel, Melody Gardot, Alison Krauss etc then the GEC6as7g is for me the stand out tube. I find the Vocals are just stunning.
  
 I have seen Cara Dillon perform a number of times now small venues and from only a few meters away. After listening via my crack soon after the GEC and T1 nailed it big time I was simply amazed at how well the music was reproduced when compared with the live performance.
  
 I am absolutely on the same page as Skeptic when it comes to the costs and that the price performance ratio is out of kilter. but that's just supply and demand and no different to spending $1000 on a interconnect. As per the previous topic you can get some good deals on tubes, over the last couple of months there have been about a dozen or so NOS TS 5998  going for $100 a pair and a few GEC gas7g brown base's for around the $75 mark.
  
 The real performance stars are the better sounding 6080's which often slip under the radar and go for only a few dollars.


----------



## DefQon

I've got an off topic joke for you guys to take a break from all the crack talk.
  
 (In reference to the Nitendo 64 game Mario Karts and such).
  
 What pants does Mario wear?


----------



## JamieMcC

defqon said:


> I've got an off topic joke for you guys to take a break from all the crack talk.
> 
> (In reference to the Nitendo 64 game Mario Karts and such).
> 
> What pants does Mario wear?


 

 Go on then I will be the patsy,
  
 I don't know what pants does Mario wear?


----------



## DefQon

Denim denim denim.


----------



## UmustBKidn

defqon said:


> Denim denim denim.


----------



## punit

http://www.mariomayhem.com/downloads/sound_tracks/Super_Mario_Bros._1/02-underworld.mp3
  
 sounds like Denim.... (I had to google to find the answer)
  





 (i couldn't find "banging my head on a wall" emoticon 
	

	
	
		
		

		
		
	


	




)


----------



## palmfish

jamiemcc said:


> The TS 5998 and E80cc are my Cracks daily drive. I save the GEC and Osram tubes (they are the same) for premium listening session when the house is quiet and I am able to relax and just focus on the music.
> 
> I also feel the GEC is more refined in the mids, upper mids and treble. Though I really only use it for one genre of music if you like artists like Eva Cassidy, The Wailin Jennys, Cara Dillon, Simon & Garfunkel, Melody Gardot, Alison Krauss etc then the GEC6as7g is for me the stand out tube. I find the Vocals are just stunning.
> 
> ...




You're comparing headphone listening to a live performance? 

Are you listening to your crack or smoking it...lol?


----------



## JamieMcC

palmfish said:


> You're comparing headphone listening to a live performance?
> 
> Are you listening to your crack or smoking it...lol?


 

 Nope, I was commenting on how good a job the T'1s do at reproducing the tone and timbre of vocals and instruments. The comment follows on from the paragraph above it. My apologies if it was not clear and you misunderstood.


----------



## NightFlight

loquah said:


> Do try the T1s if you ever get a chance. They're relatively warm despite the treble peak and the Crack helps to keep them sounding nice and smooth - not quite HD6x0 smoot, but still smooth.




I've determined that 'smooth crack sound' is mostly due to stock configuration. You can liven it up with tube / cap and wire changes. I find the RCA 6080 a bit too warm and syrupy now that I've grown accustomed to a CV4003 driving a TS5998. I've upgraded my caps to a pair of Mundorf and signal path with legenburg rectangular copper. The stock carol tinned copper is great for who are soldering noobs, but the legenburg made enough of a difference to rip it out. All IMHO of course. Lol


----------



## cheneric

Can I use the crack for my studio monitors? I Read somewhere that its not a good idea to amplify something that's already amplified, but I can't find that anymore.


----------



## Loquah

cheneric said:


> Can I use the crack for my studio monitors? I Read somewhere that its not a good idea to amplify something that's already amplified, but I can't find that anymore.


 
  
 Simply put, no. You'd be best to get the S.E.X. for that purpose because it has output transformers to interface with a low impedance load like speakers whereas the Crack doesn't and is only designed for high impedance loads.


----------



## cheneric

I need a splitter on my DAC to my crack since I also use studio monitors. Will this affect volume or quality? I would have a total of 3 splits from my dac: bottlehead, subwoofer, and studio monitors. 
  
 Edit: Took me about 3 days to read all 272 pages of crack goodness. I can't wait for mine to ship!!! Got the speedball also. Hopefully I can hold myself back from installing the speedball for a while!


----------



## JamieMcC

I do the same and have noticed no difference. I have just brought a second splitter awaiting arrival as I found the first ones connections put an unequal force on to the dac's rca sockets which made for a poor connection.
  

  
 This is the new one
  
  
  
  
 this is the one I am waiting on


----------



## diaBoliQu3

Pop sound during start, and sometime got pop during music playing, left channel only. All test passed, all LED light up. What problem it could be?


----------



## Doc B.

cheneric said:


> Can I use the crack for my studio monitors? I Read somewhere that its not a good idea to amplify something that's already amplified, but I can't find that anymore.





This means your monitors are active? In that case, yes, it would work well. I needed a little line level boost in the PA setup I put together for a Jacqui Naylor show last fall and we ended up putting a Crack in line as a variable boost ahead of the long cables feeding the amps. Worked great. Of course you would need an adapter to go from TRS to RCAs or TRS to XLRs, depending upon your monitor inputs.


----------



## cheneric

doc b. said:


> This means your monitors are active? In that case, yes, it would work well. I needed a little line level boost in the PA setup I put together for a Jacqui Naylor show last fall and we ended up putting a Crack in line as a variable boost ahead of the long cables feeding the amps. Worked great. Of course you would need an adapter to go from TRS to RCAs or TRS to XLRs, depending upon your monitor inputs.


 
 Yes, they're active. Holy ****. I just got so much more excited! Very curious to how it would sound to the JBL LSR305's. 
  


jamiemcc said:


> I do the same and have noticed no difference. I have just brought a second splitter awaiting arrival as I found the first ones connections put an unequal force on to the dac's rca sockets which made for a poor connection.
> 
> 
> 
> ...


 
  
 Oh wow these look nice. Where can I get that?


----------



## JamieMcC

cheneric said:


> Yes, they're active. Holy ****. I just got so much more excited! Very curious to how it would sound to the JBL LSR305's.
> 
> 
> Oh wow these look nice. Where can I get that?


 
 This is where I brought them from, ebay, try a search.
  
 http://www.ebay.co.uk/itm/151103810623?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649


----------



## Tequilasunriser

Damn, that's sharp.


----------



## cheneric

I'm getting mixed answers to whether or not I can run the headphone amp into active speakers. Can anyone else chime in on this?


----------



## Doc B.

What is the reason you are being given that you can't do it, and by whom? The speaker manufacturer?


----------



## Nic Rhodes

It is fine, active monitors are a great solution.


----------



## cheneric

doc b. said:


> What is the reason you are being given that you can't do it, and by whom? The speaker manufacturer?


 
 I just did a quick google search:
  
 http://www.gearslutz.com/board/music-computers/843913-driving-powered-monitor-headphone-amp.html
  
 http://hardforum.com/showthread.php?t=1439974


----------



## JamieMcC

The GEC 6as7g curved bases arrived today, they look brand new and more importantly they sound very nice indeed!


----------



## punit

jamiemcc said:


> The GEC 6as7g curved bases arrived today, they look brand new and more importantly they sound very nice indeed!


 
  
  Nice, Please post some comparisons with TS 5998 (I assume you have one).
  
 Quote:


punit said:


> THe GEC synergy with HD 800 is
> 
> 
> 
> ...


 
  
 Listening to them right now, same story , different day


----------



## Nic Rhodes

jamiemcc said:


> The GEC 6as7g curved bases arrived today, they look brand new and more importantly they sound very nice indeed!


 
  grrr  great tubes


----------



## JamieMcC

nic rhodes said:


> grrr  great tubes


 
  
 Sorry nic you will be pleased to know I am all done buying tubes for the time being. Somehow I ended up buying three GEC's this week! As well as the pair I put a low offer in on one that had just been listed and much to my surprise it was accepted and even came with a 28 day guarantee! 
  
 Did you get the GEC quad?
  


> Originally Posted by punit
> 
> Nice, Please post some comparisons with TS 5998 (I assume you have one).


 
  
 I do which type single or dual getter 
	

	
	
		
		

		
		
	


	



  
 I need a bit more time with it first. Its very similar to the straight base but seems a touch more refined in the details, its hard to put a finger on at the moment. Safe to say its very much a grin inducing & toe tapping listen.


----------



## Doc B.

cheneric said:


> I just did a quick google search:
> 
> http://www.gearslutz.com/board/music-computers/843913-driving-powered-monitor-headphone-amp.html
> 
> http://hardforum.com/showthread.php?t=1439974


 
 I would suggest that "someone else may know why it won't work" and "don't turn it up too loud" are not particularly lucid technical arguments. Yes, the Crack can put out a reasonably high level into a high impedance load. So can a lot of preamps. I have confidence that you can use some judgement with respect to levels. The comment about impedance makes no sense. The low output impedance of the Crack - relative to its use at line level - is a plus. The Crack was actually used as the starting point for a series of experiments in transformerless low impedance tube preamps that led to the development of our 300B preamp. But go with what you feel is the best answer for you.


----------



## cheneric

doc b. said:


> I would suggest that "someone else may know why it won't work" and "don't turn it up too loud" are not particularly lucid technical arguments. Yes, the Crack can put out a reasonably high level into a high impedance load. So can a lot of preamps. I have confidence that you can use some judgement with respect to levels. The comment about impedance makes no sense. The low output impedance of the Crack - relative to its use at line level - is a plus. The Crack was actually used as the starting point for a series of experiments in transformerless low impedance tube preamps that led to the development of our 300B preamp. But go with what you feel is the best answer for you.


 
 Thanks, I'm definitely going to trust the person that designed this amp! I'm going to be dealing with 3 volumes here. The active monitors, my computer, and the crack. How should I go about adjusting these? I know for sure I don't want to be cranking up the crack!
  
 Edit: Oh yeah, a subwoofer is also fine right? 
  
 Excuse my basic questions...
  
 What are the do's and don'ts of a tube amp?
 When the amp is unused, turn it off..
 Plug in the output device after 10 seconds warm up?
 Unplug before turning off?
 Turn the volume all the way down, then turn off?


----------



## Loquah

cheneric said:


> Thanks, I'm definitely going to trust the person that designed this amp! I'm going to be dealing with 3 volumes here. The active monitors, my computer, and the crack. How should I go about adjusting these? I know for sure I don't want to be cranking up the crack!
> 
> Edit: Oh yeah, a subwoofer is also fine right?
> 
> ...


 
  
 Do you need the Crack in the chain? If you have volume controls elsewhere I'd question whether the Crack is bringing significant benefit (unless of course you're looking to add tubey goodness)


----------



## Sonido

loquah said:


> Do you need the Crack in the chain? If you have volume controls elsewhere I'd question whether the Crack is bringing significant benefit (unless of course you're looking to add tubey goodness)


 

 For tubiness, I found that the Quickie was a far better choice as a preamp, but you do need at least 20K ohms input impedance on your built-in amp, 40K if using PJCCS upgrade.


----------



## cheneric

loquah said:


> Do you need the Crack in the chain? If you have volume controls elsewhere I'd question whether the Crack is bringing significant benefit (unless of course you're looking to add tubey goodness)


 
 I'm looking to add tubey goodness to my active speakers! I don't use them for any recording so yeah.


----------



## mithrandir38

cheneric said:


> I'm looking to add tubey goodness to my active speakers! I don't use them for any recording so yeah.


 If Doc B says it's ok, give it a try for crying out loud! B-)


----------



## cheneric

mithrandir38 said:


> If Doc B says it's ok, give it a try for crying out loud! B-)


 
 As soon as it ships out and when I build it! Just planning ahead!


----------



## ben_r_

cheneric said:


> As soon as it ships out and when I build it! Just planning ahead!


 
 Ha ha ha nice! You def got the right idea there! All set with even the right angle everything!


----------



## Nic Rhodes

jamiemcc said:


> Sorry nic you will be pleased to know I am all done buying tubes for the time being. Somehow I ended up buying three GEC's this week! As well as the pair I put a low offer in on one that had just been listed and much to my surprise it was accepted and even came with a 28 day guarantee!
> 
> Did you get the GEC quad?


 
  
 No was outbid on the GEC 6080s. Happy you got the other GECs, I have plenty here so not worried. I have been buying these for >20 years now  so their 'qualities' aren't a new thing for me. I am still impressed by Mullard and GEC 6080 and 6AS7G / A1834s. I also have plenty of Sylvania and Tung So 7236s and Tung Sol 5998 and Chatham 2399s but nearly always return to GECs and Mullards.
  
 I assume your extra 6AS7G was the one on for £75 list? Re 5998, I found some old Angela Instrument info the other day (used to buy loads off them) and they were offering 10x 5998 Tung Sols for $135! I remember thinking they were expensive at the time 
  
 Edit. as I am musing about 5998, did you realise that Western Electric who have their 'equivalent' of 421a didn't do much work on rectifiers so their 422 is a modified 421a minus the grids!


----------



## roguegeek

Well, I just put in my order for a Crack with Speedball upgrade. Will build the base Crack first and play around with that for a while to see what the stock signature sounds like. I'm already thinking about case modifications that will relocate inputs to the back and volume/output to the front. Would love to check out designs that did that.


----------



## JamieMcC

nic rhodes said:


> Edit. as I am musing about 5998, did you realise that Western Electric who have their 'equivalent' of 421a didn't do much work on rectifiers so their 422 is a modified 421a minus the grids!


 
  
 Nic thanks for the info, I look every so often at the WE 421a but they are way over what I feel is acceptable value, especially when the GEC 6as7g can be had for a fraction of the price.


----------



## Nic Rhodes

yes the problem with WE is people are buying a massive premium for the name, the downside for us is the quality is nearly always top notch , luckily we have many great makes making top tubes like Tung Sol, GEC and Mullard.


----------



## Loquah

roguegeek said:


> Well, I just put in my order for a Crack with Speedball upgrade. Will build the base Crack first and play around with that for a while to see what the stock signature sounds like. I'm already thinking about case modifications that will relocate inputs to the back and volume/output to the front. Would love to check out designs that did that.


 
  
 Congratulations!
  
 What do you mean about the modifications? That's how it's normally designed - inputs at the back right corner, HPO and volume at the front. Or do you mean set into the timber frame?


----------



## MattTCG

I think that he means vertically on the front...where the Doc B badge would be.


----------



## bigfatpaulie

cheneric said:


> As soon as it ships out and when I build it! Just planning ahead!


 
  
 That's what I call an awesome rig "in-potentia".


----------



## roguegeek

loquah said:


> Congratulations!
> 
> What do you mean about the modifications? That's how it's normally designed - inputs at the back right corner, HPO and volume at the front. Or do you mean set into the timber frame?


 
 Well, I'm thinking of doing a different housing all together, but yeah. I want the inputs rear-facing and the output/volume front facing. Everything else stays on top.


----------



## roguegeek

Ooo! Very much like this..
  

 Yeah, I forgot to mention power rear facing as well. Whoever those are, I'm ripping off your idea.


----------



## ben_r_

roguegeek said:


> Ooo! Very much like this..
> 
> 
> Yeah, I forgot to mention power rear facing as well. Whoever those are, I'm ripping off your idea.


 

 That would be Head-Fi user themusic2's build, and that was an early rendition. You can see more of the final version here: LINK
  
 That chassis plate was a custom design and cut deal and IIRC it was $120 to have made.


----------



## Doc B.

Those pics are great. Which reminds me - we had an unfortunate loss of our archved images on the Bottlehead Forum when we changed web hosts. If anyone has posted some pics of their projects in the past I would appreciate your reattaching a new copy of the pic to your original post. It's really a bummer that some great looking pics were lost, and I imagine a lot of them are still on someone's hard drive.


----------



## Serenitty

Wow, I like the looks of that ^^^.  I ordered my kit Tuesday night and now I'm tempted to pick up some aluminum and do some bending and drilling.  Is the layout of the holes on the board available anywhere? 
  
 Thanks...


----------



## SNSDluv

Does anyone know if there are any sonic differences between the Tung-Sol 6080WA with Westinghouse label or without?
 Heard people say the one with Westinghouse pairs really well with HD700. Please let me know!


----------



## roguegeek

ben_r_ said:


> That would be Head-Fi user themusic2's build, and that was an early rendition. You can see more of the final version here: LINK
> 
> That chassis plate was a custom design and cut deal and IIRC it was $120 to have made.
> 
> ...


 
  
 Seems so worth it. What I'd like to do is build it as directed and spend some time with it like that just so I'm familiar with the construction. Then I'll look at changing things around. I'm guessing a lot of the parts attached to the chassis plate are easily removed (looks like simple bolts from the pics I'm seeing) and to get the right placement, it just means extending or contracting certain wires. Would this assumption be correct?


----------



## ben_r_

roguegeek said:


> Seems so worth it. What I'd like to do is build it as directed and spend some time with it like that just so I'm familiar with the construction. Then I'll look at changing things around. I'm guessing a lot of the parts attached to the chassis plate are easily removed (looks like simple bolts from the pics I'm seeing) and to get the right placement, it just means extending or contracting certain wires. Would this assumption be correct?


 

 If you have a decent amount of experience with doing stuff like this it would be MUCH better to have it all built out your modding plane ready to go before you ever build it as it is much more than a few bolts to remove all the stuff from an already built Crack. There is a lot of de-soldering and moving of parts. Id say you have to disassemble maybe 30% of the amp to get it entirel out of the chassis. Maybe more.


----------



## Doc B.

Do bear in mind however that whenever you change positions of components you can run into noise pickup issues that may not be there with the stock layout. Not saying don't do it, just saying beware that you may have to incorporate some changes like shielded input wiring.


----------



## Serenitty

I've tried searching for it, but do you know if anyone has mounted an ODAC board inside the Crack case?  I imagine that might require some shielding.  Though you could make the input wires short by hard-wiring to the volume control.
  
 I am looking forward to this kit... Should be lots of fun.


----------



## ben_r_

serenitty said:


> I've tried searching for it, but do you know if anyone has mounted an ODAC board inside the Crack case?  I imagine that might require some shielding.  Though you could make the input wires short by hard-wiring to the volume control.
> 
> I am looking forward to this kit... Should be lots of fun.


 

 Hardwiring to the volume control? Wouldnt you hard wire it to the RCA inputs of the Crack?


----------



## Serenitty

I shouldn't have said anything.  i don't have my kit yet, I haven't read my instructions, I just thought the braided wires from the back of the amp went from the rca inputs to the potentiometer.  And since they can pick up noise, shortening them would potentially be good if you were looking to mount a DAC in the cabinet.  I know someone posted in 2012 that they were going to do that, but I can't find any posts about the results.  it might be a disaster, or require more shielding than it's worth.  I don't know.
  
 Thanks..


----------



## ben_r_

serenitty said:


> I shouldn't have said anything.  i don't have my kit yet, I haven't read my instructions, I just thought the braided wires from the back of the amp went from the rca inputs to the potentiometer.  And since they can pick up noise, shortening them would potentially be good if you were looking to mount a DAC in the cabinet.  I know someone posted in 2012 that they were going to do that, but I can't find any posts about the results.  it might be a disaster, or require more shielding than it's worth.  I don't know.
> 
> Thanks..


 

 Im sure it would be fine. And your thinking is not incorrect, I was just thinking the RCA jacks since they are at the back of the amp and thats where I would imagine one might want a USB cable hanging out.


----------



## Serenitty

Not that I'm anywhere near doing this, but from looking at the ODAC board, the USB input is already hardwired to the board, so I figured I'd run the usb cable under the lip of of the amp and plug it in internally.
  
 Realistically I'll be running the amp off my E17 for a while as I get used to it, integrating a DAC would be a later step.  I'm already planning on building my own box before my kit arrives to make it taller, both for a possible integrated DAC and maybe if I end up with larger caps later on.
  
 That and I want to have the woodwork done before the kit arrives.  And if I can get a layout of the top plate, I may prep a plate beforehand so I can do metal front and back with the wood sides.  I really like how that looks.  Especially getting the power and inputs off the top.


----------



## ben_r_

serenitty said:


> Not that I'm anywhere near doing this, but from looking at the ODAC board, the USB input is already hardwired to the board, so I figured I'd run the usb cable under the lip of of the amp and plug it in internally.
> 
> Realistically I'll be running the amp off my E17 for a while as I get used to it, integrating a DAC would be a later step.  I'm already planning on building my own box before my kit arrives to make it taller, both for a possible integrated DAC and maybe if I end up with larger caps later on.
> 
> That and I want to have the woodwork done before the kit arrives.  And if I can get a layout of the top plate, I may prep a plate beforehand so I can do metal front and back with the wood sides.  I really like how that looks.  Especially getting the power and inputs off the top.


 

 Or if you wanted to get fancy it could be easily wired up to something like this after a hole was drilled into the chassis plate: LINK


----------



## cheneric

My crack just shipped! Only took 2 and a half weeks! WOOOOO!
  
 inb4NSA


----------



## bdr529

serenitty said:


> I've tried searching for it, but do you know if anyone has mounted an ODAC board inside the Crack case?  I imagine that might require some shielding.  Though you could make the input wires short by hard-wiring to the volume control.
> 
> I am looking forward to this kit... Should be lots of fun.




I was thinking about the same thing! I spent a long time looking on mouser for a suitable plate mount USB connection but didn't have any luck. If you find something be sure to share it.

edit: This was the closest thing to what I wanted that I could find. http://www.mouser.com/ProductDetail/Amphenol-Commercial-Products/MUSBD111M1/?qs=sGAEpiMZZMulM8LPOQ%252byk2gY1MHiEitGbcPcC%252bF64O8%3d


----------



## mcandmar

Or try the Neutrik http://ie.mouser.com/ProductDetail/Neutrik/NAUSB-W/?qs=sGAEpiMZZMulM8LPOQ%252bykxlHbbYuR%252bstGsMnbIcUG4E%3d
  
 Its a pass through connector so i would use a short shielded USB cable and an encased ODAC inside the chassis to shield it.


----------



## mordicai

cheneric said:


> I need a splitter on my DAC to my crack since I also use studio monitors. Will this affect volume or quality? I would have a total of 3 splits from my dac: bottlehead, subwoofer, and studio monitors.
> 
> Edit: Took me about 3 days to read all 272 pages of crack goodness. I can't wait for mine to ship!!! Got the speedball also. Hopefully I can hold myself back from installing the speedball for a while!


 
 I run my Crack with Powered monitors........Macbook Pro>JRiver>Emotiva Dac with xlr outs to the speakers, USB out to the Crack. Its one of the reasons I bought the Emotiva DC-1 Dac.


----------



## bdr529

mcandmar said:


> Or try the Neutrik http://ie.mouser.com/ProductDetail/Neutrik/NAUSB-W/?qs=sGAEpiMZZMulM8LPOQ%252bykxlHbbYuR%252bstGsMnbIcUG4E%3d
> 
> Its a pass through connector so i would use a short shielded USB cable and an encased ODAC inside the chassis to shield it.




Yeah, that's the thing I don't like. It's not really a device USB port and is quite large.


----------



## roguegeek

cheneric said:


> My crack just shipped! Only took 2 and a half weeks! WOOOOO!
> 
> inb4NSA


 
 So... I just ordered last night. How long is this thing going to take to get to me?


----------



## Sonido

roguegeek said:


> So... I just ordered last night. How long is this thing going to take to get to me?


 

 A couple weeks. In case you didn't know: http://bottlehead.com/bottlehead-kit-delivery-status/


----------



## JamieMcC

Crack Cap rolling update
  
 Cascade bypass of JFX 100uf Premium film audio coupling capacitors
  
 Bypassed with
  
 Russian K75-10 Hybrid Paper and Polyethylene Terephthalate in Oil (Mylar)
  
 Bypassed with
  
 Russian Teflon K72P6 Teflon
  
 Beyer T1 and TS 5998 used for listening
  
 I find myself enjoying the pairing of these capacitors they sound much better than the odd look they have shoehorned into the enclosure and held together with cable ties might suggest.
  
 It has taken over 200hrs for the combination to settle down and a more coherent and refined sound to emerge.
  
 With the Crack I find the K75-10 really very musical, fluid and engaging, PRaT is good its has a slightly dark flavour at lower volumes.  John L mentions  “jest and pop” in the presentation in his capacitor review ( http://www.head-fi.org/t/284863/orgy-of-capacitors-the-cap-thread) this comes through strongly and is very much akin to listening to vinyl on my Rega Planner 3, Just instant tow tapping head nodding enjoyment. Its a very engaging sound. 
  
 Here’s the thing with the K75-10 I find it very musical the downside is the roll off. The top end has lost a lot of its crispness, gone is the metallic ting on triangles and cymbals which have now turned to softer schings instead of the crisp detailed ting, the bass is also a little loose and bloomy.
  
 So I tried adding a K72P6 Teflon bypass to the K75-10 things started to improve while still keeping much of the K75-10 character.  With over 200hrs burn in the K72P6 Teflon influence on the top end has settled down and it makes for a much more coherent and refined sound, which the K75-10 lacked on its own.
  
 Details and resolution are vastly improved while still keeping some of the zest and pop which I found engaging.
  
 The aspect I have found most pleasing with this combination is the vocal presentation, both male and female voices come across beautifully with nice tone and texture and enough detail in the resolution to pick up the little nuances in word formation and expression.
  
 The film and Teflon bypass capacitor combinations are throwing up some surprises and these Russian ex-military capacitors I have been experimenting with cost about the same as a cup of coffee each.
  
 This is a combination that I could happily listen to for a long time.
  
 pics
  
 
  
 
  
 Edit thinking about it I will mark up the caps so I can always return them to the same positions later if need be.


----------



## MattTCG




----------



## JamieMcC

matttcg said:


>


 

 lol That looks like something you would buy from a adults only store !


----------



## MattTCG

You're one to talk!! I've been watching your post. 
	

	
	
		
		

		
		
	


	



  
 Getting very close to Crack heaven. Just a few more days.


----------



## JamieMcC

matttcg said:


> You're one to talk!! I've been watching your post.
> 
> 
> 
> ...


 

 Matt have you decided on how you are going to finish your top plate? I must have changed my mind a dozen times whilst waiting for mine to arrive!


----------



## MattTCG

The build was done by zashoomin...


----------



## JamieMcC

Matt that looks super smart in black, on the bright side at least after waiting when it arrives you will be able to just plugin and play! I will look forward to your impression with the obbligato capacitors once all has burned in. I very nearly went with the obbligatos myself but never having swapped capacitors before I was a little daunted by their larger size and my own lack of experience.
  
 Good things come to those who wait...


----------



## MattTCG

What is a reasonable burn in time for caps?


----------



## ben_r_

lokesen said:


> I have just finished this Bottlehead Crack. Default cabinet with three layers of chestnut wood stain, five layers of spar varnish with 400 grit sanding between and a polish of the varnish after a week of hardening.
> 
> The panel has been spray painted with 8 layers of hammered dark grey paint.
> 
> ...


 

 I have been looking EVERYWHERE for a dark grey hammered spray paint and cant find it anywhere! I have found black, silver (light grey) and grey, but no dark grey from Rustoleum or Krylon. What brand paint did you use for that chassis plate?


----------



## spacequeen7

I replaced my pot yesterday and I'm little disappointed ,swapped stock pot for Alps Blue Velvet and things got a lot quitter is this normal ,is there burn-in period for this pot ??
  
 EDIT; my adapter came in also and it works like a charm 
 http://www.ebay.com/itm/300980566962?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649


----------



## JamieMcC

The jfx films I fitted needed about 100 hours the sonics definitely improved over time as they burned in. Was the Crack you had on loan stock or modded?


----------



## JamieMcC

spacequeen7 said:


> I replaced my pot yesterday and I'm little disappointed ,swapped stock pot for Alps Blue Velvet and things got a lot quitter is this normal ,is there burn-in period for this pot ??


 
  
 There seem to be mixed views on the Alps  Blue Velvet. There are apparently some cheap knock offs about. Did you get your channel imbalance sorted?
  
  
 I was blown away by the Valab stepper, the difference was very noticeable has anyone else tried this?


----------



## spacequeen7

jamiemcc said:


> There seem to be mixed views on the Alps  Blue Velvet. There are apparently some cheap knock offs about. Did you get your channel imbalance sorted?
> 
> 
> I was blown away by the Valab stepper, the difference was very noticeable has anyone else tried this?


 
 yes ,imbalance no more -I replaced phone jack ,RCA jack ,rerouted cables


----------



## JamieMcC

Nice work, how are you finding the Daytons?


----------



## spacequeen7

need more time to burn-in ,with the stock pot it was about 5% improvement


----------



## roguegeek

matttcg said:


> The build was done by zashoomin...


 
 Is that just paint on the top? How did you get the orange peel effect?


----------



## Sonido

roguegeek said:


> Is that just paint on the top? How did you get the orange peel effect?


 

 Lol usually that's indication of a poor paint job and something to be avoided when it comes to cars. Pretty sure if you just spray paint away without any care, it turns out like that. Once again, coming from car paint jobs.


----------



## roguegeek

Haha. I'm actually very familiar with orange peel with automotive paint. Automotive media and press is the industry I work in. In this case, though, I think the texture really adds to the finish on the amp. I'm think grey/charcoal/slate stain for the wood and a glossy black orange peel for the chassis.


----------



## Sonido

roguegeek said:


> Haha. I'm actually very familiar with orange peel with automotive paint. Automotive media and press is the industry I work in. In this case, though, I think the texture really adds to the finish on the amp. I'm think grey/charcoal/slate stain for the wood and a glossy black orange peel for the chassis.


 

 Guess it will be difficult for you to create the orange peel effect on purpose.


----------



## roguegeek

sonido said:


> Guess it will be difficult for you to create the orange peel effect on purpose.


 
 hehe Don't you have more K812 listening to do?!


----------



## olegausany

roguegeek said:


> sonido said:
> 
> 
> > Guess it will be difficult for you to create the orange peel effect on purpose.
> ...



Isn't K812 are low impedance headphones?


----------



## roguegeek

olegausany said:


> Isn't K812 are low impedance headphones?


 
 Relatively. I didn't mean listening with the Crack.


----------



## NightFlight

jamiemcc said:


> There seem to be mixed views on the Alps  Blue Velvet. There are apparently some cheap knock offs about. Did you get your channel imbalance sorted?
> 
> 
> I was blown away by the Valab stepper, the difference was very noticeable has anyone else tried this?




I have the Khozmo stepper. I posted pics on the BH forums. The change was very good!


----------



## RAZRr1275

Out of curiosity, how much are head-fiers charging to assemble a crack with speedball? I'm not diy savvy


----------



## diaBoliQu3

sonido said:


> Guess it will be difficult for you to create the orange peel effect on purpose.


 
 It can be done. Powdercoating with hammerite effect, and just make them thicker. Mine have similar finishing. For those smooth glossy paint, the layer will be thick.


----------



## skeptic

matttcg said:


> The build was done by zashoomin...




Looks great Matt! Hope you enjoy those obbligato output caps as much as I am enjoying mine.


----------



## MattTCG

skeptic said:


> Looks great Matt! Hope you enjoy those obbligato output caps as much as I am enjoying mine.


 
  
 Me too...


----------



## Tonequest

Hi.
 Damn... Been gone for a week and I have 17 pages to catch up... Still pondering between the Crack and S.E.X. I have active speakers so why not focus just on headphones...?
 Thanks!


----------



## Tonequest

roguegeek said:


> Is that just paint on the top? How did you get the orange peel effect?


 
 By applying a too-heavy lacquer coat all at once...? This doesn't happen if you spray thin layers of lacquer. So if you want that, spray a heavier coat on and you're done...


----------



## Tequilasunriser

I was able to achieve the effect with thin layers and some light sanding.

Get some krylon hammered effect spray paint. Do about 3 thin layers and then sand lightly, then 3 thin layers and sand even lighter, and then a final 3 think layers. Takes a while but the effect can be achieved with the investment of time and hammered effect spray paint.


----------



## Tonequest

tequilasunriser said:


> I was able to achieve the effect with thin layers and some light sanding.
> 
> Get some krylon hammered effect spray paint. Do about 3 thin layers and then sand lightly, then 3 thin layers and sand even lighter, and then a final 3 think layers. Takes a while but the effect can be achieved with the investment of time and hammered effect spray paint.


 

 Great tips there!


----------



## JamieMcC

When I sprayed the clear coat on my crack I made a vented hot box out of a old cardboard box to put the crack in to speed up the process, I attached the crack to small board so once I had shot a coat of clear I could pick the board up and transfer the Crack to the hot box @ 45-50 degree C, every 10 mins or so take it out and bang on another coat you can get a good build up very quickly without issues or sanding between coats.
  
 I use this method a fair bit. Also have had some good results with wet on wet colour then clear.


----------



## lost&confused

I built this amp the other day I'm blown away,   I've never heard my old hd600 sound this good EVER, I was very sceptical and read about this little amp for years so I treated myself  and so happy i did...This is the only headphone product I've ever bought that I can honestly say was totally worth it....Much higher than my expectations.... My  headphones sound superb now totally amazed me. It makes me jumpy around and dance! Such a good sound.
 I know about hyped stuff but this amp deserves total praise and the price is just unreal.
 I've only got the standard crack and just changed the rca sockets but I  ordered the speedball yesterday.
 I'm only using it with a computers creative Zxr soundcard with different opamps, I'm playing music from different artists I would never play and songs I don't even like and everything sounds amazing!
 brilliant amp


----------



## JamieMcC

lost&confused said:


> I built this amp the other day I'm blown away,   I've never heard my old hd600 sound this good EVER, I was very sceptical and read about this little amp for years so I treated myself  and so happy i did...This is the only headphone product I've ever bought that I can honestly say was totally worth it....Much higher than my expectations.... My  headphones sound superb now totally amazed me. It makes me jumpy around and dance! Such a good sound.
> I know about hyped stuff but this amp deserves total praise and the price is just unreal.
> I've only got the standard crack and just changed the rca sockets but I  ordered the speedball yesterday.
> I'm only using it with a computers creative Zxr soundcard with different opamps, I'm playing music from different artists I would never play and songs I don't even like and everything sounds amazing!
> brilliant amp


 

 Congratulations it only gets better with the Speedball.


----------



## lost&confused

Thanks Jamie   I'm a  bit worried with the sound change with the speedball upgrade lo...  I think it sounds brill as is!  I can always put it back to stock ,  not read many ppl doing that so must be good 
  
 Loads of reading to do


----------



## MattTCG

^^ Don't worry, I thought the same thing. I started with stock and liked it so much that I didn't want to mess with it. Trust me...you'll like the SB even better. It's the most significant improvement to the stock crack IMO.


----------



## lost&confused

Cheers Matt ..I can't wait now ..
  
 Can't believe how much its  changed the sound of my old HD600s , I was going to buy new headphones but wont be doing that now.
  
 I have the really old HD600 with black drivers,    I stayed up till 3:00 am last night rocking lo.   Any type of music I play sounds ace..... Rock sounds fantastic and my italo. disco 
  
 I'm going to look at upgrading the caps soon... I went stupid today on ebay and  paid £80  for a CV491 / 12AU7 Mullard K61 Code tube ,   now I read that adding the speedball you cant tell much of a difference with the driver tube. I also ordered a RCA 6AS7G top getter black plate but that was only £20 odd.
  
 I'm going to hold off now and just enjoy it.
  
 Thanks all


----------



## MattTCG

The hd6x00 with the crack and speed ball is much better than I ever imagined. I think for most owner of the 600 or 650 who haven't heard their hp on this amp...they would be shocked to hear just how good it sounds.


----------



## JamieMcC

I really dig the odd ball/ old school looks of the Crack and can understand why its not for some people. Personally I think it can push  the boundary between function and artistic expression, their are some truly outstanding and inspirational builds out there .
  
 It certainly makes for a interesting conversation piece when it gets spotted connected up to the turntable  when visitors come over. There is always the what is that and its got valves sticking out of it or it is the twenty century now you know times have moved on what are you bothering with that old fashion stuff.
  
 This is normally met by do you fancy a listen see how it sounds (interestingly nobody has ever declined this invitation). Pull out a record and with out fail there is either a look of astonishment a big grin or both. Its a gem to watch for the expressions.


----------



## spacequeen7

coming soon ..if interested please PM me


----------



## MattTCG

^^ Looks great!! I tried to make those dovetailed corners but gave up.


----------



## JacobLee89

spacequeen7 said:


> coming soon ..if interested please PM me


 
 A dovetail, inside a dovetail, inside a dovetail?
  
 I might just end up staring at that joint more-so than listening to music if I had that for my Crack!


----------



## Zashoomin

roguegeek said:


> Is that just paint on the top? How did you get the orange peel effect?


 
 Just to answer your question it is hammered paint so it naturally does that so it is very much on purpose.


----------



## whirlwind

Personally, I really love the old school look of the BHC.....to me it looks awesome, and I much prefer it to the newer looking sleek models of other amps.


----------



## roguegeek

zashoomin said:


> Just to answer your question it is hammered paint so it naturally does that so it is very much on purpose.


 
 Yeah. It looks great. Consider this idea stolen.


----------



## JacobLee89

So many cool ideas. Though all I can imagine myself doing is just painting it all Orange, and hating myself for it.


----------



## Loquah

jacoblee89 said:


> So many cool ideas. Though all I can imagine myself doing is just painting it all Orange, and hating myself for it.


 
  
 LOL. That could be a first though!


----------



## Doc B.

Many years ago a guy brought some amps (wish I could remember which - maybe oldskool SEX amps) to the Craftsman room at VSAC. He had done the chassis panels in bright yellow and the transformers in blue and IIRC red bases. By the description you are probably thinking "blimey!", but they looked really cool.


----------



## JamieMcC

I had a old boss who used to paint lots of things in the Green Bay Packers colour scheme even his 80ft yacht! Cool idea and much easier to do with your amplifier.


----------



## roguegeek

jamiemcc said:


> I had a old boss who used to paint lots of things in the Green Bay Packers colour scheme even his 80ft yacht! Cool idea and much easier to do with your amplifier.


 
 Being a Bears fan, I just barfed in my mouth a little.


----------



## JamieMcC

roguegeek said:


> Being a Bears fan, I just barfed in my mouth a little.


 

 lol, here ya go
  
 Will remove later being off topic.


----------



## UmustBKidn




----------



## cheneric

doc b. said:


> I would suggest that "someone else may know why it won't work" and "don't turn it up too loud" are not particularly lucid technical arguments. Yes, the Crack can put out a reasonably high level into a high impedance load. So can a lot of preamps. I have confidence that you can use some judgement with respect to levels. The comment about impedance makes no sense. The low output impedance of the Crack - relative to its use at line level - is a plus. The Crack was actually used as the starting point for a series of experiments in transformerless low impedance tube preamps that led to the development of our 300B preamp. But go with what you feel is the best answer for you.


 
 Hey Doc,
  
 So I just noticed my speakers have a built in feature to change the input sensitivity: http://www.jblpro.com/www/products/recording-broadcast/3-series/lsr305#Specs
  
*Selectable Input Sensitivity *- The -10 dB/+4 dB sensitivity switch ensures compatibility with a broad range of signal sources, allowing you to connect the 3 Series to high output professional gear without any danger of input overload.
  
 Was this the general concern about using a headphone amp for active speakers in the first place? Would this be useful along with the Crack?


----------



## Doc B.

Yes, using the +4 setting to reduce the speaker amp input sensitivity will give you more range of adjustment from the Crack volume knob and a little more insurance against running the speaker amps into clipping. If you have level controls at the input of the amp just set them low enough that you can't drive the amps into hard clipping no matter how high you turn the crack volume knob.


----------



## cheneric

swmtnbiker said:


> I bought a pre-built Crack + Speedball from a fellow Head-fier a few weeks ago and couldn't be happier with the amp. Not only does it sound absolutely *phenomenal* with my HD 650, the build is a thing of beauty. It's a very, very cleanly done job with braided wiring pre-cut to the proper length and practically flawless soldering. The Crack's wood housing however was received in its raw state, so this past week I decided to complete it. Ordered a Bottlehead badge from Doc to top it all off and settled on a distressed satin black finish with a few "antique " dings and dents here and there. Thought I'd post a few pics. Here ya go...


 
  
 What are those rings around the tubes? I find them aesthetically pleasing. 
  
  


doc b. said:


> Yes, using the +4 setting to reduce the speaker amp input sensitivity will give you more range of adjustment from the Crack volume knob and a little more insurance against running the speaker amps into clipping. If you have level controls at the input of the amp just set them low enough that you can't drive the amps into hard clipping no matter how high you turn the crack volume knob.


 
  
 So -10db makes it more sensitive and +4db makes it less sensitive to volume changes? I thought it was the other way around


----------



## skeptic

Tube dampers.  See, e.g., http://herbiesaudiolab.net/tube.htm


----------



## cheneric

skeptic said:


> Tube dampers.  See, e.g., http://herbiesaudiolab.net/tube.htm


 
 Thanks! Didn't expect them to cost that much though..


----------



## swmtnbiker

cheneric said:


> Thanks! Didn't expect them to cost that much though..


 
  
 Dude, welcome to Head-fi.


----------



## JacobLee89

cheneric said:


> Thanks! Didn't expect them to cost that much though..


 
  
 Wait until you see the price of 3rd party cables. I'd rather go through 10 different makes of these tube dampeners than spend money on brand slapped wire.


----------



## JamieMcC

.


----------



## Doc B.

cheneric said:


> So -10db makes it more sensitive and +4db makes it less sensitive to volume changes? I thought it was the other way around


 
 Those are standards for the signal level coming out of the source equipment. In other words the amp needs not be as sensitive for a +4dBU (studio standard) signal source as it needs to be for a -10dbV (roughly the home audio standard) source. Note also that the units are different between the two standards and IIRC the difference is really more like 12dB  than 14dB.


----------



## MattTCG

Bottlehead sale Tuesday only.10% off just got an email.


----------



## bleudeciel16

matttcg said:


> Bottlehead sale Tuesday only.10% off just got an email.


 

 noooooo, I just ordered like two days ago.
  
 that being said, I'm a soon to be owner of the crack with speedball upgrade (soon being 3-4 weeks lol)


----------



## roguegeek

bleudeciel16 said:


> noooooo, I just ordered like two days ago.
> 
> that being said, I'm a soon to be owner of the crack with speedball upgrade (soon being 3-4 weeks lol)


 
 I ordered just a couple days ago too. Sent them an email looking to see if I could get credit back. Otherwise, I'm going to cancel and reorder.


----------



## whirlwind

Can anybody throw up a quick list of what headphones work well with the BHC.


----------



## MattTCG

Sennheiser 6x0, most of the Beyers that are 300 ohm...others can help me fill in.


----------



## Serenitty

roguegeek said:


> I ordered just a couple days ago too. Sent them an email looking to see if I could get credit back. Otherwise, I'm going to cancel and reorder.


 

 I just ordered last week, I'm not thrilled...  Don't think I'll cancel and reorder though.


----------



## MattTCG

I missed the sale by a few weeks. Oh well...


----------



## Serenitty

matttcg said:


> I missed the sale by a few weeks. Oh well...


 

 Yeah, it happens, I'm not going to stress.  I learned last year not to order from 1964ears near a Holiday.  I totally wasn't expecting a labor day sale.  The sale popped up while I was still waiting on my V6's, though not by much.


----------



## Doc B.

whirlwind said:


> Can anybody throw up a quick list of what headphones work well with the BHC.


 
 Try looking here:
  
 http://bottlehead.com/which-amp-should-i-buy-for-my-headphones/


----------



## JamieMcC

I removed the cascade bypass caps I was experimenting with and have been running the with my original JFX films for a few days in stock form to re-accustom myself with the presentation. Next up it’s the turn of the Valab Fast Power 47uf pio (polypropylene in oil)which I am going to try first with just one 47uf capacitor with the 600ohm T1 and then with two paralleled for 94uf. A couple of different bypasses will also be given a go in a week or two.


----------



## Sonido

doc b. said:


> Try looking here:
> 
> http://bottlehead.com/which-amp-should-i-buy-for-my-headphones/



Any experience for the AKG K812 (36 ohms)? Mainline or SEX?


----------



## FraGGleR

I just wanted to say that I hate all of you in this thread.  I want SO badly to build a Crack after reading about all of your builds.  Doc ALMOST got me with the sale, but I managed to hold off.  
  
 Just have too much stuff right now and incoming to justify it.  
  
 Carry on.


----------



## Armaegis

The true spirit would be to sell off stuff that hasn't even arrived yet to fund the purchase of new toys...


----------



## MattTCG

^^ The crack is already a great buy. The sale just makes it that much better. I waited for months for a sale but should have waited a few more weeks.


----------



## JacobLee89

armaegis said:


> The true spirit would be to sell off stuff that hasn't even arrived yet to fund the purchase of new toys...


 
  
 The trick is selling stuff that nobody seems to want.


----------



## Doc B.

sonido said:


> Any experience for the AKG K812 (36 ohms)? Mainline or SEX?


 
 Should work with either one. But considering the placement of the K812 as a flagship it seems Mainline might get the chance to show its more refined sound.


----------



## whirlwind

doc b. said:


> Try looking here:
> 
> http://bottlehead.com/which-amp-should-i-buy-for-my-headphones/


 
  
 Thank you, Doc.


----------



## Loquah

Echoing Doc's remarks on the K812, I haven't heard them yet, but based on Tyll's review at Inner Fidelity and his comments about the K812s not handling strident sound well, I'd definitely lean towards the Mainline for its extra levels of control and refinement.
Of course, this is just conjecture and the SEX is a great amp (and not harsh). Perhaps ask in the Bottlehead thread - there might be some more SEX / Mainline owners lurking there who also have K812s.


----------



## Sonido

I'm at a loss for words... was not expecting this.
  
 http://www.head-fi.org/t/685339/akg-k812-pro/1965#post_10353684
  
 The K812 really doesn't need a lot of power. No wonder it plays great out of a portable device. Maybe this can be of use to your Bottleheadphone being low impedance as well. How far does the volume knob need to go for the Bottleheadphone to get to listening levels, Doc?


----------



## Loquah

sonido said:


> I'm at a loss for words... was not expecting this.
> 
> http://www.head-fi.org/t/685339/akg-k812-pro/1965#post_10353684
> 
> The K812 really doesn't need a lot of power. No wonder it plays great out of a portable device. Maybe this can be of use to your Bottleheadphone being low impedance as well. How far does the volume knob need to go for the Bottleheadphone to get to listening levels, Doc?


 
  
 Interesting. How would you describe the bass of the K812 + Crack compared to the K812 + other amps?


----------



## JamieMcC

Interesting, I often listen to my ATH W1000X  Impedance: 42 ohms with the Crack, aside from some short comings in the bass you might be surprised how good it sounds out of the Crack, I was..
  
 Also the difference on the ATH when running 5998 vrs 6080 is quiet noticeable with the 5998 giving much better results.
  
 The ATH are also good for checking the noise floor, with the T1 and Senn 650 my Crack has a completely black background right up to full volume,  No music playing obviously,
  
 With the ATH W1000X and 6080 fitted the noise floor starts to kick iin when I reach the 17th step of my 23 step attenuator
 With the 5998 fitted the noise floor is not heard until 20th step of the 23 step attenuator.
  
 Normal listing is in the 2-6 step range with 7 starting to get painful,
  
 The W1000X with the Crack running a 5998 and E80cc is honestly an enjoyable enough listen.


----------



## Sonido

loquah said:


> Interesting. How would you describe the bass of the K812 + Crack compared to the K812 + other amps?



A bit softer and not as sharp. That's pretty the effect throughout. Especially helps in the lower treble that used to hurt my ears, but now is smoothed out.



jamiemcc said:


> Also the difference on the ATH when running 5998 vrs 6080 is quiet noticeable with the 5998 giving much better results.



I forgot to mention I was using 5998 as well. Haven't tried 6080 with K812 yet. Will do later today.


----------



## Sonido

Just tried with 6080 and it's just as good. No noise floor issues. Volume knob need to go a bit higher to 9 o'clock. I listened more carefully for the bass and compared it to a low output impedance (0.5 ohms) amp in the Questyle CMA800R and I prefer the bass from Crack more. The K812 bass can be too sharp for me, and the softening of the Crack is perfect for it. I was testing with Crescendolls by Daft Punk. The bass difference is quite noticeable on the intro of the song, and sounds smoother and better on Crack. This was on 6080. Switching back to 5998, the bass is closer in sharpness to the Questyle. Heck after just some basic comparisons, I could make the argument the K812 synergizes better with the 6080. It's even smoother, and I personally find harshness in the K812 so this is really good for me. As for quantity of bass, I don't find a decrease or roll off at all with either tubes.


----------



## SNSDluv

sonido said:


> Just tried with 6080 and it's just as good. No noise floor issues. Volume knob need to go a bit higher to 9 o'clock. I listened more carefully for the bass and compared it to a low output impedance (0.5 ohms) amp in the Questyle CMA800R and I prefer the bass from Crack more. The K812 bass can be too sharp for me, and the softening of the Crack is perfect for it. I was testing with Crescendolls by Daft Punk. The bass difference is quite noticeable on the intro of the song, and sounds smoother and better on Crack. This was on 6080. Switching back to 5998, the bass is closer in sharpness to the Questyle. Heck after just some basic comparisons, I could make the argument the K812 synergizes better with the 6080. It's even smoother, and I personally find harshness in the K812 so this is really good for me. As for quantity of bass, I don't find a decrease or roll off at all with either tubes.


 
 Which 6080 are you talking about?  :O


----------



## Sonido

snsdluv said:


> Which 6080 are you talking about?  :O


 

 Tung Sol 6080 WA. Came standard with my Crack.


----------



## Doc B.

sonido said:


> I'm at a loss for words... was not expecting this.
> 
> http://www.head-fi.org/t/685339/akg-k812-pro/1965#post_10353684
> 
> The K812 really doesn't need a lot of power. No wonder it plays great out of a portable device. Maybe this can be of use to your Bottleheadphone being low impedance as well. How far does the volume knob need to go for the Bottleheadphone to get to listening levels, Doc?




The Bottleheadphone - which we decided to rename Crackheadphone for the sake of clarity - started with a stock Monoprice headphone that we modded for better performance with the Crack. It's very much tweaked to perform well specifically with the Crack. The final result is pretty evenly balanced tonally, with nice punchy bass. The stock Monoprice headphone does not sound as good connected to a Crack amp and the Crackheadphone doesn't sound its best with amps other than Crack. It's a really tweaky pairing and it will play loud enough to get into the long term hearing damage range - which seems to be a requirement of headphones these days 

IME asking "how far do you turn the knob" is not particularly relevant unless you are talking about comparing two headphones from the same music source. The output level of various DACs and players is all over the map.

For those who will ask, the manual for the Crackheadphones is being tested with the build of a sample pair and as soon as that is done (next couple of days) we should begin packing kits.


----------



## Sonido

doc b. said:


> IME asking "how far do you turn the knob" is not particularly relevant unless you are talking about comparing two headphones from the same music source. The output level of various DACs and players is all over the map.



Is it fair to compare with another headphone then regardless of DAC or source? I find the K812 need only have the volume knob turned slightly more to get the same volume as HD800, like 20 degrees at most. What's the Crackheadphone in respect to the HD800 in volume knob position? What is the power output for the Crack at 32 ohms?

P.S. just personal opinion, but Crackphone has a better ring to it for me


----------



## JacobLee89

sonido said:


> Is it fair to compare with another headphone then regardless of DAC or source? I find the K812 need only have the volume knob turned slightly more to get the same volume as HD800, like 20 degrees at most. What's the Crackheadphone in respect to the HD800 in volume knob position? What is the power output for the Crack at 32 ohms?
> 
> P.S. just personal opinion, but Crackphone has a better ring to it for me


 
  
 The DAC question is constantly haunting me: Do I change into an asynch USB DAC which uses a high speed wizard kaboom chip with 32 bit/192 trumpet ability, or shall I just DIY a USB isolator for my ODAC?
  
 But as far as I've read, the amplifier section is where most of the change happens. I can't go wrong with a Crack (pending funding and willpower) connected to my HD650.


----------



## Sonido

jacoblee89 said:


> The DAC question is constantly haunting me: Do I change into an asynch USB DAC which uses a high speed wizard kaboom chip with 32 bit/192 trumpet ability, or shall I just DIY a USB isolator for my ODAC?
> 
> But as far as I've read, the amplifier section is where most of the change happens. I can't go wrong with a Crack (pending funding and willpower) connected to my HD650.



DAC makes a bigger difference once you have a very transparent amp and headphone. Think of each component in your chain as a glass window. If the window closest to you is dirty, it doesn't matter if the other windows further up the chain are clean. IMO the Crack isn't the last word on transparency, but more musicality oriented.


----------



## JacobLee89

sonido said:


> DAC makes a bigger difference once you have a very transparent amp and headphone. Think of each component in your chain as a glass window. If the window closest to you is dirty, it doesn't matter if the other windows further up the chain are clean. IMO the Crack isn't the last word on transparency, but more musicality oriented.


 
  
 Thanks for the analogy. It's the battle of the "USB" DAC's that confuses me far more so than anything else.
  
 However the de-railed ranting is over, and since I am already happy with how my HD650's perform (even with the Objective stack) I am sure to enjoy the changes offered by the crack. DAC's can just sit at a "no need to care" corner of my brain until I can no longer modify the crack.


----------



## MattTCG

I haven't followed the info on the bottlehead dac. Can anyone share an update or link?
  
 thanks...


----------



## JacobLee89

matttcg said:


> I haven't followed the info on the bottlehead dac. Can anyone share an update or link?
> 
> thanks...


 
  
 I don't think there is one. Unless Doc B is thinking otherwise.
  
 the mention of DACs was added once the discussion of comparing headphones came into the equation.


----------



## Armaegis

sonido said:


> P.S. just personal opinion, but Crackphone has a better ring to it for me


 
  
 Following a completely logical naming derivation... bottleheadphone... crackheadphone... crackphone... crackcan... the kraken? 
	

	
	
		
		

		
		
	


	



  
  


sonido said:


> DAC makes a bigger difference once you have a very transparent amp and headphone. Think of each component in your chain as a glass window. If the window closest to you is dirty, it doesn't matter if the other windows further up the chain are clean. IMO the Crack isn't the last word on transparency, but more musicality oriented.


 
  
 Though as corollary, in my opinion DACs hit diminishing returns far far sooner.


----------



## Loquah

I disagree. I'm on my phone so linking is a pain, but check out my DAC upgrade edit at the end of the Crack review on the Bottlehead Comparison Thread. It really opened my eyes (ears?).

Also, according to the Bottlehead forum thread, their DAC is approaching a final prototype build which I think will represent the production design. No news on release date, but it's sounding VERY interesting!


----------



## spacequeen7

received my second socket today and both work flawlessly ...I must be very lucky I guess 
  http://www.ebay.com/itm/300980566962?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
 http://www.ebay.com/itm/320659633166?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
  
 EDIT; there might be very slight hum (@ very high gain) on the second one


----------



## skeptic

loquah said:


> Also, according to the Bottlehead forum thread, their DAC is approaching a final prototype build which I think will represent the production design. No news on release date, but it's sounding VERY interesting!


 
  
 Yup, I believe Doc indicated that John Swenson actually has the first production board up and run now.  So excited for this!


----------



## JacobLee89

skeptic said:


> Yup, I believe Doc indicated that John Swenson actually has the first production board up and run now.  So excited for this!


 
  
 I shall continue to scratch my head at DACs until people stop over-zealously defending the ODAC.
  
 Though a DIY one by Bottlehead is something I'm definitely interested in. Anyone with an idea how fidgety it could be compared to the Pupdac? - another DAC I'm looking into -


----------



## punit

spacequeen7 said:


> received my second socket today and both work flawlessly ...I must be very lucky I guess
> http://www.ebay.com/itm/300980566962?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
> http://www.ebay.com/itm/320659633166?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
> 
> EDIT; there might be very slight hum (@ very high gain) on the second one


 

 I have the first socket, working flawlessly till now (touch wood)


----------



## Loquah

jacoblee89 said:


> I shall continue to scratch my head at DACs until people stop over-zealously defending the ODAC.
> 
> Though a DIY one by Bottlehead is something I'm definitely interested in. Anyone with an idea how fidgety it could be compared to the Pupdac? - another DAC I'm looking into -


 
  
 I know the main board will be pre-assembled so no tiny surface mount soldering. Sounds like it'll be similar to other BH kits (i.e. relatively basic soldering with requirements for patience, care, and following instructions rather than epic electronics ability).


----------



## syphen606

Finally got all my parts in!!  Started this morning with some stain, and painting. 
  
 Stain is "Mahogany" and the paint is "Carbon Mist".    I was walking around the local Home depot and these colours caught my eye. Still waiting for things to dry before I start the Varnish on the box.
  


  
 Can anyone identify this tube? There is no manufacturer markings that I can see, only a faint 6080WB.  The tube was filthy when I opened it, but thankfully a microfibre and a touch of windex cleaned it right up.


----------



## GeorgeNapalm

*syphen606*, that looks great! That's a good idea to stain the wood before gluing. I stained after gluing and had problems with the spots where glue touched the wood.


----------



## bleudeciel16

Does the top plate get very hot?
  
 I ask because I happen to have a replicator 2 3d printer, which I believe should have a big enough print area to print a case for my crack amp (which should be here in a few weeks).
  
 UPDATE:  sorry, i wasn't very clear.  the reason I ask why it's hot is because the PLA plastic that the printer prints has a fairly low melting temperature.  different colors have different melting temps.  (clear/white melts at a really low temp, and black has the highest melting point)  didn't want to print a case (would take all day at a high resolution setting) only to have the hot tubes heat up the plate, causing the casing to melt lol
  
 also, if i go through with this and it turns out, i'll post the sketch up on thingiverse so others can print it out if they choose they want to do plastic over the wood.  (though I think plastic will look cheap compared to the wood which can be stained or painted)


----------



## ben_r_

bleudeciel16 said:


> Does the top plate get very hot?
> 
> I ask because I happen to have a replicator 2 3d printer, which I believe should have a big enough print area to print a case for my crack amp (which should be here in a few weeks).
> 
> ...


 

 It does get very hot. Less so it seems with the Speedball upgrade. Not sure if it gets hot enough to melt plastic, but IMO it gets almost too hot to comfortably touch.


----------



## syphen606

bleudeciel16 said:


> Does the top plate get very hot?
> 
> I ask because I happen to have a replicator 2 3d printer, which I believe should have a big enough print area to print a case for my crack amp (which should be here in a few weeks).
> 
> ...


 
  
 I don't know the answer as my Crack isn't assembled yet, but looking at the resistors that it comes with (5W), there will be some good heat being thrown out. The top plate will help as a bit of a heat sink.


----------



## JacobLee89

bleudeciel16 said:


> Does the top plate get very hot?
> 
> I ask because I happen to have a replicator 2 3d printer, which I believe should have a big enough print area to print a case for my crack amp (which should be here in a few weeks).
> 
> ...


 
  
 The question I'd like to ask is whether the case will be printed as one solid object, or in separate parts. If in separate parts, you may be able to shape another material that could isolate the heat of the plate from the case.
  
 And "cheap" looking plastic is all about the finish. With some careful sanding, priming, and paint finishing, you can achieve almost all sorts of surface finishing (minus stained wood effects). That's talking about days of work though


----------



## JamieMcC

3D printing is a neat idea you could have a honeycomb or lattice type structure so would have great ventilation and also use much less filament in the printing even add in a different colour to create some text with in the structure.


----------



## Doc B.

Actually the same amount of heat is generated. It's just radiated differently, as the resistors in the stock kit are close to the chassis panel and the heat sinks of the Speeball upgrade are farther away. So the temperature gradient is a little more steep around the cooling slots on the stock version. It's probably more useful to measure the panel temp at the edge where it contacts the base.


----------



## MattTCG

I have a question for those who have a crack plus another amp. I also have the lyr and wondered if I could use the preamp out to connect to the crack. Or would this alter the sound too much. It would be nice not to have to plug/unplug I/C's between the dac and amp each time that I want to switch. Is there a better solution?


----------



## Sonido

matttcg said:


> I have a question for those who have a crack plus another amp. I also have the lyr and wondered if I could use the preamp out to connect to the crack. Or would this alter the sound too much. It would be nice not to have to plug/unplug I/C's between the dac and amp each time that I want to switch. Is there a better solution?



Quickie+Crack is a great combo for both HD800 and K812. You can hear it at the Charlotte meet if you're coming.


----------



## MattTCG

^^ I'm sure hoping to make it to the meet. Yes, I'd love to hear those two together.


----------



## RonO

Hi Matt - 
  
 Here's my solution with ODAC to Crack and to Audio-gd Fun:
  

  
 Blue goes to FUN ,and grey goes to the Crack.  Works great.
  
 Ron


----------



## MattTCG

Thanks Ron. You did you get the adapters?
  
 thanks...


----------



## RonO

In my case, I got these originally with a subwoofer cable, and you would use the splitter sub side to take the single LFE output to the L + R inputs on a sub.  There is a really short cable that came with it as well.  I had two subs, so I had two of these. Years later, I went to a component subwoofer, dual passive subs powered by a pro audio amp, and no longer needed a splitter, there is a feature in the amp to split the signal internally to both channels.  It just hit me the other day to put these to use again on the ODAC.  
  
 I did a quick google search, I see several devices that look similar. Hey, when is the Charlotte meet?
  
 RonO


----------



## Sonido

rono said:


> In my case, I got these originally with a subwoofer cable, and you would use the splitter sub side to take the single LFE output to the L + R inputs on a sub.  There is a really short cable that came with it as well.  I had two subs, so I had two of these. Years later, I went to a component subwoofer, dual passive subs powered by a pro audio amp, and no longer needed a splitter, there is a feature in the amp to split the signal internally to both channels.  It just hit me the other day to put these to use again on the ODAC.
> 
> I did a quick google search, I see several devices that look similar. Hey, when is the Charlotte meet?
> 
> RonO


 
 http://www.head-fi.org/t/696198/charlotte-nc-meet-april-19th-2014


----------



## MattTCG

Tube question. I recently purchased a backup TS 5998. The backup says, "Tung Sol Chatham." The Original just says Tun Sol. Numbers under 5998 on the backup are 3226040 and the original 3225740-3.
  
 Any help is appreciated.


----------



## olegausany

I had Chatham and it was working without problem ans sounded great


----------



## RonO

Matt - 
  
 Here's a link: http://www.tubemaze.info/tung-sol-23995998-top-getter/
  
 Looks like all the 5998's were made by tung sol, but some were sold under other badges, like the chatham lablel as 2399.  I tried 5998's over a  year back and could not get one without a hum in it. The third one they sent to me was a 2399.  I settled on a 6as7ga, which are usually about $10, except when I want the Crack to sound like a Marshall stack, and run the full Russian tube set, and plug in the Rammstein.
  
 RonO


----------



## JamieMcC

So far I have come across three different types of 5998 with the domino black or grey plates under four different brands
  
 Types
  
 Top getter
 Top and side Getter
 Clear top
  
 Brand
  
 Tung Sol
 Chatham
 Heinz and Kaufman
 Arcturus


----------



## MattTCG

Great info!! thanks...


----------



## Nic Rhodes

To Jamies list I can add Burroughs Corporation, I remember turning a load down from Angela Instruments as they were $135 for ten! Thought they were too expensive at the time! [mid 1990s], they were made in 1965.


----------



## JamieMcC

Cheers Nic added it to the list
  
 5998 Types
  
 Top getter
 Top and side Getter
 Clear top
  
 Brand
  
 Tung Sol
 Chatham
 Heinz and Kaufman
 Arcturus
 Burroughs Corporation


----------



## syphen606

Test fitting and gluing!   I can almost start the electronics assembly in earnest.


----------



## dxanex

^ very nice finish...Looks great!


----------



## jgreen16

^^ I concur, very nice looking. I'd love to see more pics during the course of the build. I'm seriously thinking about doing a Crack project myself.


----------



## DairyProduce

Me too! The mainline also seems interesting...but barely anyone is talking about it (maybe because it's relatively new and expensive?)


----------



## spacequeen7

I'm liking my new PEC 100k so far ,also I took a bit different approach on connecting Dytons


----------



## syphen606

jgreen16 said:


> ^^ I concur, very nice looking. I'd love to see more pics during the course of the build. I'm seriously thinking about doing a Crack project myself.


 
  
 Here is today's progress. I have some errands and other things to do, so I'll have to come back tomorrow.


----------



## jgreen16

Thanks for the progress pics. I'm really enjoying watching this go together.

I can tell it won't be long before I place my order.


----------



## syphen606

Well, I ended up with some more time this evening that wasn't expected and it was smooth sailing. Turned it on for the first time and took all my measurements. Everything looked good, so I plugged in a sacrificial set of cans to see if there was noise. So far, so good! Then pulled out my HD650's and am loving it so far! Super happy with how its turned out.
  
 I still don't know who makes the 6080WB as there is no markings on it. The other tube is an HP 5963 tube.  The sound is fantastic. Gonna play with it for the next little while and then maybe look at the speed ball.


----------



## JamieMcC

spacequeen7 said:


> I'm liking my new PEC 100k so far ,also I took a bit different approach on connecting Dytons


 
  
 That's a neat idea for the attaching the caps. I was in the local diy superstore looking for some draw handles the other the other day there were quiet a few types of handle that would easily double as capacitor mounting brackets. Its getting a bit tight for room now on my Crack .
  

  
  
 Quote:


syphen606 said:


> Well, I ended up with some more time this evening that wasn't expected and it was smooth sailing. Turned it on for the first time and took all my measurements. Everything looked good, so I plugged in a sacrificial set of cans to see if there was noise. So far, so good! Then pulled out my HD650's and am loving it so far! Super happy with how its turned out.
> 
> I still don't know who makes the 6080WB as there is no markings on it. The other tube is an HP 5963 tube.  The sound is fantastic. Gonna play with it for the next little while and then maybe look at the speed ball.


 
  
 Nice job, I only lasted a week with the Crack in standard form before curiosity got the better of me and the speedball went in.


----------



## spacequeen7

jamiemcc said:


> That's a neat idea for the attaching the caps. I was in the local diy superstore looking for some draw handles the other the other day there were quiet a few types of handle that would easily double as capacitor mounting brackets. Its getting a bit tight for room now on my Crack .


 






 just wondering how much does the crack weigh with all the caps you got there


----------



## Loquah

syphen606 said:


> Well, I ended up with some more time this evening that wasn't expected and it was smooth sailing. Turned it on for the first time and took all my measurements. Everything looked good, so I plugged in a sacrificial set of cans to see if there was noise. So far, so good! Then pulled out my HD650's and am loving it so far! Super happy with how its turned out.
> 
> I still don't know who makes the 6080WB as there is no markings on it. The other tube is an HP 5963 tube.  The sound is fantastic. Gonna play with it for the next little while and then maybe look at the speed ball.


 
  
 That's a fantastic looking build, syphen!!
  
 As for your tube, it looks a lot like the GE (I think) that came with my Crack. I'll see if I can track down a pick in my sale thread to double check the brand and will edit this post if I can confirm.
  
 Edit: Confirmed that mine was a GE 6080WC which looked identical to your tube in the pics


----------



## Rem0o

jamiemcc said:


> Quote:
> 
> Nice job, I only lasted a week with the Crack in standard form before curiosity got the better of me and the speedball went in.


 
 Your crack sure has balls, blue ones at that.


----------



## JamieMcC

spacequeen7 said:


> just wondering how much does the crack weigh with all the caps you got there


 

  I would guess caps add about 400 grms extra per side more than the standard build.


----------



## cjoh242

Hello,
  
 I was directed over here before I went and purchased a Schiit amp as I was told this is the best amp for the hd-650's.
 After looking at everything and going back about 17 pages I fell in love with all the builds and personal touches. Wow! I would really like to get a BH Crack, and build it myself, but I have never done any soldering and know most nothing about electronics from the inside. I am just now getting to learn about tubes. My two questions;
  
 1. Could someone like me with no experience actually build one
 2. If not, how do I get someone to build one for me or do I need to wait for one on the sale forum?
  
 I really appreciate your time and feedback in advance...
 Newbie out.
  
 CJJ


----------



## spacequeen7

quick question 
 is any oil based spray paint good for painting transformer ?


----------



## syphen606

cjoh242 said:


> Hello,
> 
> I was directed over here before I went and purchased a Schiit amp as I was told this is the best amp for the hd-650's.
> After looking at everything and going back about 17 pages I fell in love with all the builds and personal touches. Wow! I would really like to get a BH Crack, and build it myself, but I have never done any soldering and know most nothing about electronics from the inside. I am just now getting to learn about tubes. My two questions;
> ...


 
  
  
 I think almost anyone could build one if you follow the directions implicitly. They were very well written and have enough theory and information to get you started. I would recommend a little practice soldering but that is as easy as getting some wires and practice attaching things. At the end, the measurements are the most important part.


----------



## syphen606

spacequeen7 said:


> quick question
> is any oil based spray paint good for painting transformer ?


 
  
 Painting the transformer? Its laquered so you'll need to take that into account.  Or are you talking about the bell housing for the transformer?


----------



## williaty

cjoh242 said:


> 1. Could someone like me with no experience actually build one
> If you are patient and can carefully follow well written instructions, you can absolutely build a Crack.







> 2. If not, how do I get someone to build one for me or do I need to wait for one on the sale forum?



In the past, it was possible to have your kit built by sort of a factory-authorized builder. I'm not sure what the current status on that is but I'm sure you can go to the Bottlehead Forum and ask to get a quick answer.


----------



## spacequeen7

syphen606 said:


> Painting the transformer? Its laquered so you'll need to take that into account.  Or are you talking about the bell housing for the transformer?


 
 both..I noticed that some of you guys paint the transformer and was wondering how and what (the transformer I have is not evenly covered by lacquer and needs to be painted )
 I want something that will last


----------



## olegausany

cjoh242 said:


> Hello,
> 
> I was directed over here before I went and purchased a Schiit amp as I was told this is the best amp for the hd-650's.
> After looking at everything and going back about 17 pages I fell in love with all the builds and personal touches. Wow! I would really like to get a BH Crack, and build it myself, but I have never done any soldering and know most nothing about electronics from the inside. I am just now getting to learn about tubes. My two questions;
> ...



Check for sale forum I saw one yesterday


----------



## jgreen16

I believe there is also someone that builds them, and their info is posted in the forums on the Bottlehead site. be prepared to pay the price though, but I'm sure you would receive a quality build.


----------



## cjoh242

do you guys think a newbie like me, who can read and not get electrocuted btw, could actually use the directions and youtube and build this dude? Never soldered before, but I can learn
  
  
 if I do this is there any tips you all can give or pitfalls I need to be aware of? Easy upgrades I can do on my own or cautionary tales that I need to know about (ie painting the plate and heat or something)
  
 thanks again


----------



## Sonido

cjoh242 said:


> do you guys think a newbie like me, who can read and not get electrocuted btw, could actually use the directions and youtube and build this dude? Never soldered before, but I can learn
> 
> 
> if I do this is there any tips you all can give or pitfalls I need to be aware of? Easy upgrades I can do on my own or cautionary tales that I need to know about (ie painting the plate and heat or something)
> ...


 

 It's not that difficult. Just make sure you read exactly when to solder and when to simply attach.


----------



## HPiper

I wonder if a person posted here somewhere that they would build some kits for people, would it be worth it. Would you be able to charge enough to make it worth your time. I am thinking probably not, but I don;t think that amp would take that long to build once you had done 2 or 3 and got the logistics down solid.


----------



## jgreen16

From the Bottlehead forums:
  
 We are happy to announce that we have formed an alliance with our good bud Shawn Phelps, aka Scratch_P, and now aka hifibuilderguy. Some of you know that Shawn was our assembly tech here for several years, and he knows how to assemble our kits as well as anyone on the planet. His work is meticulous and reliable.

 Shawn has decided to strike out on his own and we are pleased as punch to refer anyone who might want their kit built for them to Shawn. You should contact Shawn directly at hifibuilderguy@gmail.com to arrange assembly and payment. Ordering the kit from us would be done the usual way, and we can get your kit to Shawn when it is ready. Shawn is also the moderator on this forum and can answer your questions about the service he provides. This service is independent of Bottlehead Corp. Bottlehead guarantees the parts used in the kit, and hifibuilderguy guarantees the assembly service.

 Here is Shawn's preliminary price list:

 Bottlehead Kit Build Pricing - note this is price for the assembly service only, it does not include the kit price

 Crack   $250
 W/Speed + $90
 -------------------------
 Mainline  $850
 ---------------------------
 S.E.X   $550
 C4S +$70
 Imp Switches + $90
 --------------------------
 Tode   $600
 -----------------------
 Stereomour   $675
 Imp Switches +$90
 ----------------------
 Paramount  $1250
 --------------------
 Reduction   $350
 C4S + $100
 ------------------
 Eros   $600
 Tape Head Eros +$100
 ------------------
 Submissive   $275
 --------------------
 Bee Pre   $900
 W/Bee Quiet +$150
 ---------------------
 Power Cord   $80
 Bottlenect RCA Interconnect  $60

 All bases/bell end/plates assembled stock (see upgrades below):

 Add + $30 for sanded base w/ clear coat (per base)
 Add + $25 for blued bell w/clear or Hammertone painted bell
 Add + $40 for Hammertone painted plate (your choice of color)
 Add + $30 Black screw option (all top side screws in black)
 Add + $30 Cardas Quad Eutectic solder used throughout assembly


----------



## williaty

Hpiper, to answer your question, I'd charge pretty much spot on what the official Bottlehead builder (Shawn P.) charges. If you figure about how long it takes to assemble a kit and about what a reasonable wage is for moderately skilled work, the prices listed are very reasonable to both parties.


----------



## UmustBKidn

jgreen16 said:


> ...
> Here is Shawn's preliminary price list:
> 
> Bottlehead Kit Build Pricing - note this is price for the assembly service only, it does not include the kit price
> ...


 
  
 That's actually a very reasonable price, from what I can tell.
  
 For those who have never touched a soldering iron before - I suppose any estimate of your ability would be prefaced with another question: have you ever attempted to build anything else? Are you the mechanically inclined sort? Or do you take your car to someone else to get the oil changed? Built any models?
  
 Something I would recommend, just to get your feet wet with some kind of electronic assembly, would be to buy a cheap kit, like a little project from an electronic shop. Here's an example from Fry's electronics. Anything on that page that includes a circuit board and a few things to solder, would be an inexpensive way to develop soldering skills. Especially something like that Sound to Light kit - for 5 bucks, its just too hard to pass up. And it's a cute little toy you can give to your kids. Or save for your kids, when you build some 
	

	
	
		
		

		
		
	


	




 Or you can just practice on a few loose wires.
  
 Soldering is not hard once you've done it a few times. Don't breathe the fumes. Work in a garage or other open space. You hold a couple wires together, heat them with the soldering gun, and touch the junction with solder, and flow the liquid metal over the connection. Don't let it get too hot or the insulation on the wires will melt. If you're not good with holding things together, get a little jig like this cute gadget they call a Helping Hands (just Google it, they are sold everywhere for $6 to $15). Comes with a magnifying glass too.
  
 The more interesting challenge is learning how to deal with electricity. Especially when you start plugging things in, and charging up capacitors. The bottom of your amp is open. You don't want to go grabbing anything under there when it's plugged in, or hasn't been discharged. Once you start plugging things into the wall, you need to develop a healthy respect for electricity, because you can be seriously hurt if you touch live wires or connections.


----------



## spacequeen7

I'm pretty amazed how different some tubes can sound from one amp to another ..I have few 6SN7 tubes and two that stand out and worth mentioning is Tung Sol 6SN7 WGTA (1962 black plates) -this tube opened up about 50% (soundstage) in comparison to my other amp and became very airy , the other one is TUNG SOL 6SN7GT (1942 ) - on DV336SE this tube is all about the detail but on crack the vocals are in your face and the mids are insane ,I would recommend giving 6SN7 to 12AU7 socket converter a try
  

  
 EDIT; three more tubes  worth looking in to 
 soundstage beast 
 http://www.ebay.com/itm/400659651920?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
 liquid mids and tight bass
 http://www.ebay.com/itm/171253161671?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
 if your 650s need that sparkle on top
 http://www.ebay.com/itm/151001685074?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2648


----------



## MattTCG

I'm interested in the Tesla.


----------



## spacequeen7

^^ my favorite small tube


----------



## JamieMcC

Your going to love the E80cc when you try it. 
  
 I have been offloading my 12au7's only keeping a Mullard 4003 box plate, Tung-sol 12au7 Black glass and  a early Tung-sol jtl.


----------



## spacequeen7

I'm dying for Bendix and Mullard (power) if you see some on the other side of the pond please PM me


----------



## FlySweep

matttcg said:


> I'm interested in the Tesla.


 
 I have the Tesla (mine has yellow printing, though).. Ironically enough.. I'm using it now.  It takes a while to burn in.. once it does.
  
 WOW.
  
 Easily one of the most refined, dynamic, thoroughly engaging tubes I've heard in the Crack.  Its one of my favorite 12AU7s... a terrific tube that does very little, if anything, wrong.  Refinement is the word that keeps coming to mind as I listen.  Terrific soundstage and the mids are gorgeous.  Very clear and tonally pure.  In terms of impressiveness, it's up there with the Ken Rad 12AU7 black plates (for me).


----------



## prtuc2

Hello everyone just a question regarding building the crack.  How many of you build the crack while using the multimeter to check the voltage? I have place my order for the crack, but last time I use a multimeter smoke came out.  If it is not must have item I will try to avoid it.  Thanks for any feedback.


----------



## ben_r_

prtuc2 said:


> Hello everyone just a question regarding building the crack.  How many of you build the crack while using the multimeter to check the voltage? I have place my order for the crack, but last time I use a multimeter smoke came out.  If it is not must have item I will try to avoid it.  Thanks for any feedback.


 

 It is a must have.


----------



## JamieMcC

spacequeen7 said:


> I'm dying for Bendix and Mullard (power) if you see some on the other side of the pond please PM me


 
 Like to try the Bendix 6080 myself, just been outbid on one that's listed on ebay at the moment.  When shipping from the US to the UK it normally adds $15-$20  I have noticed a lot of sellers using the ebay global shipping service which seems to be a real rip off expecting you to pre pay import duty when none is required below a certain threshold this with their expensive shipping costs ends up near doubling the cost of a tube which is in the $10-$30 range


----------



## MattTCG

About to take the maiden voyage with stock tubes for now.


----------



## FlySweep

jamiemcc said:


> Your going to love the E80cc when you try it.
> 
> I have been offloading my 12au7's only keeping a Mullard 4003 box plate, Tung-sol 12au7 Black glass and  a early Tung-sol jtl.


 
 Jamie..

 I don't know if you have a 6F8G-to-12AU7 adapter, but if you do.. have you heard a Mullard 6F8G in your Crack?  Absolutely _wonderful_.  That lovely Mullard sound.. but tighter, clearer, more spacious, faster (and with better freq. bandwidth) than I've heard from most of the Mullard 12AU7 variants.  I bet it might be easier to come across on your side of the pond, too.  I sense it would be terrific with the T1.


----------



## prtuc2

ben_r_ said:


> It is a must have.


 
 Thanks, will have to pick up a decent quality multimeter and read the instructions carefully this time.


----------



## JamieMcC

matttcg said:


> About to take the maiden voyage with stock tubes for now.


 
  
 Neat 
	

	
	
		
		

		
		
	


	




  tell me some more about your rca inter-connects they look rather good to..
  
  


flysweep said:


> Jamie..
> 
> I don't know if you have a 6F8G-to-12AU7 adapter, but if you do.. have you heard a Mullard 6F8G in your Crack?  Absolutely _wonderful_.  That lovely Mullard sound.. but tighter, clearer, more spacious, faster (and with better freq. bandwidth) than I've heard from most of the Mullard 12AU7 variants.  I bet it might be easier to come across on your side of the pond, too.  I sense it would be terrific with the T1.


 
  
 I didn't know you could do that will, look into it thanks for the heads up. From your description it sound very much in the same vain as the E80cc.


----------



## MattTCG

^^ The IC's are called Timbre by Kimber Kables. I like them because the connection itself is short and doesn't protrude too much when used with crack. 
  
 I've been listening to the lyr with the 650's for a few weeks, so this first listen gives me the best opportunity to hear the difference between amps. Even on stock tubes, the crack with sb is appreciably better than the lyr. The sound is more natural and layered. The tonality of voices and instruments is spot on and lifelike. This is why I listen to music with hp's...for this kind of experience. You'd spend many thousands to get a speaker setup that sounded like this.


----------



## bleudeciel16

prtuc2 said:


> Thanks, will have to pick up a decent quality multimeter and read the instructions carefully this time.


 
  
 you don't actually need to spend a ton on a multimeter.  the cheap ones are fairly good these days.  just get one that has auto-ranging.  ones that don't are annoying to use.  also, if you can find one in your price range with capacitance measurement, that can be handy too, but resistance and voltage are the two main things you'll probably be measuring.  (and for this build, probably just resistance so you don't get your resistor codes wrong)
  
 (and this is coming from a guy who has a $400 Fluke portable multimeter and a $1000 Agilent Bench Multimeter)


----------



## ben_r_

bleudeciel16 said:


> (and this is coming from a guy who has a $400 Fluke portable multimeter and a $1000 Agilent Bench Multimeter)


 
 87-V and a 34460A?


----------



## prtuc2

bleudeciel16 said:


> you don't actually need to spend a ton on a multimeter.  the cheap ones are fairly good these days.  just get one that has auto-ranging.  ones that don't are annoying to use.  also, if you can find one in your price range with capacitance measurement, that can be handy too, but resistance and voltage are the two main things you'll probably be measuring.  (and for this build, probably just resistance so you don't get your resistor codes wrong)
> 
> (and this is coming from a guy who has a $400 Fluke portable multimeter and a $1000 Agilent Bench Multimeter)


 
 Had my eye on the Fluke 115 for a few days, but hopefully get one within budge on ebay.


----------



## ben_r_

prtuc2 said:


> Had my eye on the Fluke 115 for a few days, but hopefully get one within budge on ebay.


 

 Had one of those for years. Solid unit.


----------



## bleudeciel16

ben_r_ said:


> 87-V and a 34460A?


 
  
 holy crap lol, very impressive.  yes and almost.  my agilent is the 34461A, but close enough!


----------



## Doc B.

bleudeciel16 said:


> (and for this build, probably just resistance so you don't get your resistor codes wrong)


 
 There are voltage measurements that must be made too.


----------



## ben_r_

bleudeciel16 said:


> holy crap lol, very impressive.  yes and almost.  my agilent is the 34461A, but close enough!


 

 Ive got some Agilent and Fluke equipment myself so Ive studied the heck out of both their line ups when I was buying. The 34460A and 34461A are awesom bang for the buck and the 87-V cant be beat for a handheld meter, though I must say I do like the 289 better as it can do a lot more and is more accurate.


----------



## bleudeciel16

doc b. said:


> There are voltage measurements that must be made too.


 
  
 ah, this is good to know! thanks for the clarification


----------



## bleudeciel16

ben_r_ said:


> Ive got some Agilent and Fluke equipment myself so Ive studied the heck out of both their line ups when I was buying. The 34460A and 34461A are awesom bang for the buck and the 87-V cant be beat for a handheld meter, though I must say I do like the 289 better as it can do a lot more and is more accurate.


 
  
 can't go wrong with either brand!  one of my bench supplies is an agilent, as is my main oscilloscope.  not cheap, but you do get what you pay for!
  
 I'm still deciding how I want to finish the case for the crack.  Dark stain?  Paint it matte black?  Leave it raw?  Decisions decision!


----------



## ben_r_

bleudeciel16 said:


> can't go wrong with either brand!  one of my bench supplies is an agilent, as is my main oscilloscope.  not cheap, but you do get what you pay for!


 
 Not sure what scope you have but assuming its an 2000X or 3000X series you might be interested in this:
  
 http://www.agilent.com/about/newsroom/presrel/2014/11feb-em14028.html
  
 http://www.home.agilent.com/agilent/editorial.jspx?cc=US&lc=eng&ckey=2428917&nid=-53827.3925750.00&id=2428917&cmpid=fbultscp
  
 And this:
  
 http://www.agilent.com/find/benchvue
  
 As well as this if you didnt already know:
  
 http://www.eevblog.com/forum/testgear/dsox2000-and-3000-series-licence-have-anyone-tried-to-hack-that-scope/


----------



## dxanex

+1 on the Tesla. Very engaging and really pulls out the smaller details. Definitely worth the asking price. I'd rank it up there with the more expensive Mazda CIFTE.


----------



## FlySweep

dxanex said:


> +1 on the Tesla. Very engaging and really pulls out the smaller details. Definitely worth the asking price. I'd rank it up there with the more expensive Mazda CIFTE.


 
  
 You got it too, Dave?


----------



## MattTCG

What are you guys pairing with the Tesla? TS 5998?


----------



## dxanex

^Lol yeah! 
	

	
	
		
		

		
		
	


	




 Spent a good chunk of the weekend burning it in!
  
 Matt: yes, I paired it with the TS 5998..great results


----------



## ben_r_

flysweep said:


> I have the Tesla (mine has yellow printing, though).. Ironically enough.. I'm using it now.  It takes a while to burn in.. once it does.
> 
> WOW.
> 
> Easily one of the most refined, dynamic, thoroughly engaging tubes I've heard in the Crack.  Its one of my favorite 12AU7s... a terrific tube that does very little, if anything, wrong.  Refinement is the word that keeps coming to mind as I listen.  Terrific soundstage and the mids are gorgeous.  Very clear and tonally pure.  In terms of impressiveness, it's up there with the Ken Rad 12AU7 black plates (for me).


 
 Is an adapter required to use the Tesla?


----------



## FlySweep

ben_r_ said:


> Is an adapter required to use the Tesla?


 
  
 Nope.. the Tesla pictured is a 12AU7.  What you're seeing in my picture is a "socket saver" (from TubeMonger) that I use to maintain the integrity of the Crack's input socket.  Since I roll input tubes fairly often, I'd rather the adapter socket wear out (which is easily replaceable) rather than the Crack's input socket.  The "vibration reduction" feature is hit or miss, IME.. for a couple of more microphonic tubes I had, it actually worked well.. for a couple of others, not so much... so YMMV.


----------



## roguegeek

flysweep said:


> Nope.. the Tesla pictured is a 12AU7.  What you're seeing in my picture is a "socket saver" (from TubeMonger) that I use to maintain the integrity of the Crack's input socket.  Since I roll input tubes fairly often, I'd rather the adapter socket wear out (which is easily replaceable) rather than the Crack's input socket.  The "vibration reduction" feature is hit or miss, IME.. for a couple of more microphonic tubes I had, it actually worked well.. for a couple of others, not so much... so YMMV.


 
 How's that socket saver working out for you? There are times I feel like it's interfering with the sonics and times when it's not.


----------



## ben_r_

flysweep said:


> Nope.. the Tesla pictured is a 12AU7.  What you're seeing in my picture is a "socket saver" (from TubeMonger) that I use to maintain the integrity of the Crack's input socket.  Since I roll input tubes fairly often, I'd rather the adapter socket wear out (which is easily replaceable) rather than the Crack's input socket.  The "vibration reduction" feature is hit or miss, IME.. for a couple of more microphonic tubes I had, it actually worked well.. for a couple of others, not so much... so YMMV.


 

 Cool thanks. Might pick up one of those Tesla tubes and give it a go.


----------



## lokesen

I got myself a stepped attenuator and a G.E.C CV 2523 tube. Read about it here: 
  
http://diy.koenigs.dk/2014/03/18/stepped-attenuator-legendary-g-e-c-cv-2523-tube/
  

 Tight fit huh?


----------



## JamieMcC

lokesen said:


> I got myself a stepped attenuator and a G.E.C CV 2523 tube. Read about it here:
> 
> http://diy.koenigs.dk/2014/03/18/stepped-attenuator-legendary-g-e-c-cv-2523-tube/
> 
> ...


 
  
 Hi great write up and echoes my own experiences with a similar set up. In retrospect I feel the standard pot really acted as a veil to the sound coming through from the caps Switching to the attenuator gave a very nice improvement as you describe.
 I was also unsure about the tactile nature of clunky nature of the steps vrs the smooth feel but you soon get used to it.


----------



## bleudeciel16

ben_r_ said:


> Not sure what scope you have but assuming its an 2000X or 3000X series you might be interested in this:
> 
> http://www.agilent.com/about/newsroom/presrel/2014/11feb-em14028.html
> 
> ...


 
  
 I have the msox2024a.  I'm guessing since I already have the highest bandwidth model within the 2000 series, I'm not eligible?  They didn't word the details very clearly.  My buddy showed me that thread on eevblog forums last year and I was too scared to brick my scope to try it lol.
  
 I did hear that they were doing a promotion this year where you pay a smaller flat fee to get ALL software features unlocked.  I don't remember the price or when the promotion starts, but I might take advantage of that one.  The stock memory is pretty weak and even weak with the upgrade.  Sad they advertise segmented memory but it comes locked unless you pay to unlock it.  If you've seen the specs on the Rigol scope, you probably know that they make Agilent's stuff look pretty overpriced.  (my scope has 14 kp stock, 1 mp with paid upgrade, the rigol 2000 series has 14 mp stock, and 56 mp with paid upgrade)  Bleh.  Maybe this will force Agilent to beef up their specs for their next iteration of scopes.
  
 Back on topic: does a tube rolling thread for the crack exist yet?


----------



## Armaegis

bleudeciel16 said:


> Back on topic: does a tube rolling thread for the crack exist yet?


 
  
 I think it's this one... http://www.head-fi.org/t/476650/
  






 
  
  
  


Spoiler: Warning: Spoiler!



or this one: http://bottlehead.com/smf/index.php/topic,663.0.html


----------



## JamieMcC

There is a Crack tube rolling thread on the Bottlehead forum "Tube Rolling w/Crack"
  
 http://bottlehead.com/smf/index.php/topic,663.0.html


----------



## fetch

boy I would kill for a crack. I'm scared I'd break something building it..


----------



## MattTCG

^^ Buy one built or build. It's everything that people say it's cracked up to be.


----------



## JamieMcC

A little while back I removed the cascade bypass caps I was experimenting with and have been running with the 100uf jfx films for a few days in stock form to re-accustom myself with the presentation.
  
 Then it was up the turn of the Valab Fast Power 47uf pio (polypropylene in oil) I was curious to try just one 47uf with the 600ohm T1 then two paralleled for 94uf  and then with some different bypasses. 
  
 This is running one 47uf capacitor instead of the recommended 100uf.
  
 The sound with single 47uf has turned out to be a bit of a surprise there, is a noticeable difference in bass quality and control in the bass compared to the 100uf but it still comes across as quiet acceptably and I have listened to far worse sounding set ups.  
  
 What is clear with 47uf is that bass aside there are some nice qualities here. There was defiantly a floating in front of you quality to some vocals coming though and the smoothness I have read about being associated with the oil capacitors is evident. Transients and dynamics also come across as fast while more note decay is sustained in the background. Soundstage has closed in and has a more intimate feel to it.
  
 I had planned to run the 47uf on its own for a couple of days this didn’t work out mainly because listening to it wetted my appetite to much as to how the Crack would sound with two paralleled each side to get 97uf that is much closer to the 100uf specified.
  
 My cap experiments are a little further on than this post might suggest, I am just catching up and will update how these caps panned out once they have had a chance to burn in.


----------



## grrraymond

Jamie, you're an alchemist. Love this thread every time I come back. Needless to say, despite my early protestations of satisfaction, I'm now rolling a TS 5998 and the Mullard ECC82, but got a Brimar e80cc on the way. Also rolled a Mullard 6080 for a few days. I enjoyed it almost as much as the 5998, though it's clearly a bit different. Took me back closer to stock tubey sound but with more clarity. Looking forward to this e80cc. Might finally be time for SB though! And then step attenuator...and then...
  
 All that said, no matter what I've been running the Crack with, it's an absolute joy. I'd be happy with any of them, but just like the whisky cabinet, it's great to have different moods for the moments.


----------



## MattTCG

I have an extra 5998 if anyone is interested let me know.
  
 Also, I'm considering a quickie. Can someone who owns one pm me. I have a few questions.


----------



## olegausany

I also have many tubes for Crack some of them are great pairing with 5998


----------



## lost&confused

I'm absolutely loving this amp! best thing ive bought in hifi  this amps in a different league than the Vali amp I just sold with my hd600's I'm playing so much music I never listen to any more. 
 I ordered a tung 5998 still waiting for it,   I tried a CV491 / ECC82 Mullard supose to be a really good tube  but prefer the stock hewlett packard 5963 at the mo with stock crack so ordered another 2 ....The tubes that came with my crack stock are the  RCA jan 6080 and hewlett packard 5963 (amp sounds brilliant I'm well happy I wont be buying anything in a while  ,  I might treat myself to some T1's later.


----------



## JamieMcC

lost&confused said:


> I'm absolutely loving this amp! best thing ive bought in hifi  this amps in a different league than the Vali amp I just sold with my hd600's I'm playing so much music I never listen to any more.
> I ordered a tung 5998 still waiting for it,   I tried a CV491 / ECC82 Mullard supose to be a really good tube  but prefer the stock hewlett packard 5963 at the mo with stock crack so ordered another 2 ....The tubes that came with my crack stock are the  RCA jan 6080 and hewlett packard 5963 (amp sounds brilliant I'm well happy I wont be buying anything in a while  ,  I might treat myself to some T1's later.


 

 Great to see another UK based Crack owner. T1's+Crack make a super combo.


----------



## lost&confused

My friend just moved to the isle of wight and an architect who I get some work off lives there   nice part of the world .
  
 Yeah I'd love to try out those t1s someday.... I'm just a little worried as alot of the music I have is mp3s and love exploring youtube for music   Listening to some grandaddy tonight sounds amazing (and playing with my new tv ... amps  transformed the sound of my hd600 sounds great with anything


----------



## UmustBKidn

matttcg said:


> Also, I'm considering a quickie. ...


 
  
 There's nothing quite like a quickie.
  
 Except for maybe a nooner. Which would be a great name for a new amp...


----------



## Armaegis

The two are not mutually exclusive...


----------



## Loquah

matttcg said:


> I have an extra 5998 if anyone is interested let me know.
> 
> Also, I'm considering a quickie. Can someone who owns one pm me. I have a few questions.


 

 Matt, you're welcome to PM me with questions if you haven't already received answers. Hopefully I can help


----------



## MattTCG

Thanks for the pm Loquah!!
  
 I have another question. I have an odd sound coming periodically from my amp. I was finally able to reproduce it yesterday by tapping the pot with my fingernail. Sounds like a cowbell. The odd thing is that it happened randomly and without touching the pot. This same phenomenon happened on another crack that I borrowed. 
  
 Any thoughts?


----------



## Serenitty

matttcg said:


> Thanks for the pm Loquah!!
> 
> I have another question. I have an odd sound coming periodically from my amp. I was finally able to reproduce it yesterday by tapping the pot with my fingernail. Sounds like a cowbell. The odd thing is that it happened randomly and without touching the pot. This same phenomenon happened on another crack that I borrowed.
> 
> Any thoughts?


 
  
 Listen to "The Reaper" a lot?


----------



## ffivaz

matttcg said:


> Thanks for the pm Loquah!!
> 
> I have another question. I have an odd sound coming periodically from my amp. I was finally able to reproduce it yesterday by tapping the pot with my fingernail. Sounds like a cowbell. The odd thing is that it happened randomly and without touching the pot. This same phenomenon happened on another crack that I borrowed.
> 
> Any thoughts?


 

 Ringing sounds like Microphonics! It can be from the tubes (or sometimes caps). Doc said about it on the BH forum something like "It's a feature, not a fault!" Just don't tap the crack  You can still test which tube is more prone to microphonics, try tapping them gently or around their base. Maybe it's also some loose solder joint inside, especially the connections to the volume pot.


----------



## syphen606

I've noticed that my setup is pretty microphonic when tapping the chassis plate. Not a big deal - don't touch it!


----------



## MattTCG

The sound can come from tapping the knob of the pot. That sound is a perfect match. And then the same sound can happen 3-4 times during a listening session. But nothing is touching or tapping on the amp during that time. Not a big deal. I just wondered if others experienced this same issue.


----------



## skeptic

One of my JAN 5998's makes noises kind of like that as the tube heats up (like for up to 20-30 mins or so).  Even in the absence of any vibrations, it makes periodic high pitched "ting" sounds, sort of like what you would expect if you flicked your nail against the side of the tube and caused minor ringing.  As one might expect, that particular tube has been relegated to the bottom of the box.
  
 Do you have another 6080/6as7 you could try to see if it is just the tube?


----------



## MattTCG

I roll a few tubes and see what I get.
  
 thanks...


----------



## spacequeen7

^^ Crack seems to pick up any imperfections and is very picky about the tubes I roll ,I'm in the same boat as some of you ..I have been constantly rolling a bunch of tubes and I just discovered that the power tube have a lot to do when it comes to unwanted sounds ,for example..I would have noisy 12AU7 when listening paired with 5998 and will get about 10% of the noise with GEC...go figured


----------



## JamieMcC

spacequeen7 said:


> ^^ Crack seems to pick up any imperfections and is very picky about the tubes I roll ,I'm in the same boat as some of you ..I have been constantly rolling a bunch of tubes and I just discovered that the power tube have a lot to do when it comes to unwanted sounds ,for example..I would have noisy 12AU7 when listening paired with 5998 and will get about 10% of the noise with GEC...go figured


 

 Interesting I find the GEC's more sensitive to microphonics in my set up, things such as the headphone lead brushing against the enclosure etc can be heard through the tube. When settled in I have no problems and they sound glorious once up to temperature. It certainly feel like the sound quality is better the longer the Crack has to warm up my it seems to be at its best with a couple of hours running on the clock.
  
 I have one 5998 that will make the odd bit of noise a rustle or squeak for a second or two intermittently then its fine. This happens only after its been running for a couple of hours and then only if paired with the E80cc, with the 12au7 types its fine.
  
 Its taken me a while to figure out what works best in my own set up, all the issues I have resolved have been with interference picked up by the Crack rather than the Crack itself. Once all the cable routing was taken care off I did have some back ground noise but this turned out to be source dependent and was easily cured by using a different method of source input for the dac and related only to music streaming from one wifi device when several others worked ok. All working very now with a nice black background.


----------



## NightFlight

matttcg said:


> Tube question. I recently purchased a backup TS 5998. The backup says, "Tung Sol Chatham." The Original just says Tun Sol. Numbers under 5998 on the backup are 3226040 and the original 3225740-3.
> 
> Any help is appreciated.



322 is tung-sol. 57 is the year. 40 the week. 3rd day or shift.


----------



## bleudeciel16

matttcg said:


> The sound can come from tapping the knob of the pot. That sound is a perfect match. And then the same sound can happen 3-4 times during a listening session. But nothing is touching or tapping on the amp during that time. Not a big deal. I just wondered if others experienced this same issue.


 
  
 definitely microphonics.
  
 it never does that with my Lyr, but on my old little dot II++ amp, it had a lot of noises from the tubes.  mostly while they were heating up.  once they were heated completely (30 minutes or so), they'd stop making noises.  didn't bother me though, I got used to it.


----------



## ffivaz

It looks like the microphonics are often associated with the power tube. In my Crack, I tried three different 6AS7G (RCA, Svetlana and Rogers), all were noisy, even after some break in. I finally settle back to a rugged RCA 6080 with RCA or Telefunken 12AU7. I can dance next the crack (which happens so often with the hd650), no ringing!


----------



## MattTCG

It was the tube. Thanks guys!!


----------



## Zashoomin

matttcg said:


> It was the tube. Thanks guys!!


 
 I was reading the thread and it was making my heart race haha.  I thought it was going to be my fault lol.  Glad it is working well.


----------



## MattTCG

If anyone is looking for a crack built with professionalism and care...see zashzoomin!!


----------



## spacequeen7

Received some new candles today and I'm just blown away how good 6085 E80CC/Amperex (PQ) is ,I have vintage 6922 and Bugle Boy Treble Clef ecc88 but this was unexpected ,it brought a lot of clean/sparkly highs to my 650s and the bass is just hard to explain ...highly recommend this tubes 

 P.S. thanks Jamie for  E80CC recommendation


----------



## grrraymond

I got a Brimar E80CC this morning (had to pick it up from Post Office at 6am so I could try it out before work!) to pair with my TS 5998.
  
 My initial impressions were "HOLY screwING GAIN" and "BASS".
  
 They seem more 'upfront' than the Mullard ECC82 I had been using and they brought back the bass which had been a little 'absent'/classy once I'd replaced the the Mullard 6080 with the 5998.
  
 I understand that the Tesla or Tungsram are the ones to go for with this tube, and I read somewhere that the Brimar might not even be a true E80CC, but just wanted to share my initial impressions. I'll do a few experiments this evening.
  
 Summative thoughts on Crack (no SB) tubes at the moment:
  
 Mullard 6080 & Mullard ECC82 are a great tubey combo, liquid, enveloping, everything sounds great with them.
  
 Comparatively, the TS 5998 can seem a tiny bit clean in the bass department and a little in your face with the upper mids but it's so dynamic and engaging, I wouldn't have it any other way. Hopefully once the E80CC is burned in, it will make the perfect pairing, get a bit of meat in the bass. The only thing is that I couldn't have the volume past 9 o clock with these two, they're both so powerful.
  
 Would a step attenuator improve the controlled gain side of things?


----------



## JamieMcC

grrraymond said:


> I got a Brimar E80CC this morning (had to pick it up from Post Office at 6am so I could try it out before work!) to pair with my TS 5998.
> 
> My initial impressions were "HOLY screwING GAIN" and "BASS".
> 
> ...


 

 My E80cc took a few days to burn in it was a nos tube and the sibilance at first was grimacing. I nearly didn't listen to it again, but was burning in some caps with a old 6080 and running the Crack for around 16hrs a day (I still am) so I left the E80cc in. Every day I came home from work and had a listen it got better and also works well with all my power tubes. Its one of my favourite input tubes now tied at the spot with the Mullard cv4003.
  
 Not sure about your last question perhaps someone else will chime in.
  
 Just sold my Mullard ecc82's, but will hang on to my Mullard cv4003 and 6080.


----------



## diaBoliQu3

It's confirmed the stock 6080 tube given by BH is bad tube. Someone here ever get free tube replacement? I borrow someone's Sylvania 6080, and no popping sound. According to the guy that assembled my amp, stock tube voltage rises to 28v while the loaned tube only rise to 13v. Now, hunting for tubes... I hate tube amp, the rolling force is stronger than gravity.


----------



## grrraymond

jamiemcc said:


> My E80cc took a few days to burn in it was a nos tube and the sibilance at first was grimacing. I nearly didn't listen to it again, but was burning in some caps with a old 6080 and running the Crack for around 16hrs a day (I still am) so I left the E80cc in. Every day I came home from work and had a listen it got better and also works well with all my power tubes. Its one of my favourite input tubes now tied at the spot with the Mullard cv4003.


 
  
 Ah, that's interesting, thanks. This is my first actually New OS tube, boxed and with pin protector, shiny as you like. I'll give it a proper good burn in over the next few days and see if/how it develops.
  
 Obviously, I also have to look into that cv4003 now! A blessing and a curse...
  
 Also, and this is something I've seen mentioned in plenty of places, I tend not to leave my Crack to warm up for very long - does it make much difference? When I say not long, I mean, I'm normally eagerly waiting for it to output any volume at all...I'm going to switch it on as soon as I get in and try to leave it for an hour before listening tonight, I want to see what the difference really is.


----------



## JamieMcC

grrraymond said:


> Ah, that's interesting, thanks. This is my first actually New OS tube, boxed and with pin protector, shiny as you like. I'll give it a proper good burn in over the next few days and see if/how it develops.
> 
> Obviously, I also have to look into that cv4003 now! A blessing and a curse...
> 
> Also, and this is something I've seen mentioned in plenty of places, I tend not to leave my Crack to warm up for very long - does it make much difference? When I say not long, I mean, I'm normally eagerly waiting for it to output any volume at all...I'm going to switch it on as soon as I get in and try to leave it for an hour before listening tonight, I want to see what the difference really is.


 
  
 Grrraymond the consensus on the Bottlehead forum is that the E80cc needs to be used in conjunction with the speedball upgrade. I don't know what effect it will have running it without the speedball, it would be a good idea to check on the Bottlehead forum see if its ok to  do so. You have yet to fit the speedball havn't you?


----------



## grrraymond

That's right, Jamie. Still on stock Crack.
  
 I've just left it to warm up for an hour before reading this post, and I have to say, I do notice the difference. Think I'd better put it to one side til I get the SB in there, though...At least it's there for when the day comes.
  
 Don't want to risk nuking my Crack at this point.
  
  
 Edit: Which is a shame since it's definitely on a level above the Mullard ECC82 now I've rolled that back in 
  
 I need to just bite the bullet on SB now. I think I'm just concerned about having the necessary skills and not wanting to balls up what's already the best I've ever heard.


----------



## Loquah

grrraymond said:


> That's right, Jamie. Still on stock Crack.
> 
> I've just left it to warm up for an hour before reading this post, and I have to say, I do notice the difference. Think I'd better put it to one side til I get the SB in there, though...At least it's there for when the day comes.
> 
> ...


 
  
 You'll be fine, grrraymond. If you can build the Crack, you can do the Speedball and the best you've heard will get even better!


----------



## MattTCG

I borrowed a stock crack for a week and thought it was perfect...why would anyone want to change a thing about the wonderful stock crack. Now I have the speedball upgrade and there is no way that I could go back to stock. 
  
 As to whether or not you can handle the upgrade, that is up to you.


----------



## skeptic

Just make sure you watch a youtube clip on through hole soldering first and you will be fine.  In essence, after stuffing the component into the board, flip the board over, and hold the tip of your solder against the crack between the lead and the hole.  Then bring in your iron to touch and melt the solder at that point and hold your iron in that spot.  (The tiny amount of solder you just melted will let your iron conduct heat into the lead much more efficiently.)  Then, pull the solder away from your iron and apply/flow it on to the joint from the _opposite _side of the lead from where your iron is touching.  This will cause the solder to nicely wick around the lead, filling the hole and avoiding the irritating phenomena of the solder sticking to your iron and refusing to go down into the hole and lead.
  
 Once you master this, the hardest part of the speedball is making sure you don't damage any of the connections (in particular the led's) on your A socket when you screw in the nylon standoffs that hold the speedball boards.


----------



## ramaka

dxanex said:


> ^Lol yeah!
> 
> 
> 
> ...


 
  
  


flysweep said:


> You got it too, Dave?


 
  
 I recently bought Chatham/TS 5998 from a fellow Head-fier and ordered a Tesla ECC802S from Ebay. How long does it take to burn them in? I have a Crack Amp with no speedball upgrade yet.


----------



## JamieMcC

I found a magnifying glass very helpful for checking on my soldering of all the through hole components.


----------



## MattTCG

I spent the last week going through my library of test tracks and really putting the crack through it's paces on the hd650. Here are a few things to share:
  
 1. The 5998 is going no where and is my favorite of all the tubes I've tried. 
  
 2. There is a sense of naturalness in the tone of music that is simply sublime. The resounding pluck of an acoustic guitar string, the satisfying thump of a kickdrum, the emotional wail from a violin...just wonderfully realistic. And of course both male and female vocals are wonderfully reproduced. 
  
 3. The only setup that has bested the crack/650 for me in terms of realism of tone is the Stax sr007 mki on the BHSE. And that's pretty good company to keep IMO. 
  
 I'll dub the crack/650 the poor man's Stax rig.


----------



## NightFlight

Hmm. Here I was thinking my rig was entry level. Hoping for lots of upward scale with electrostatics.... I'm determined to try the 009 on the BHSE and see if its worth the fuss. Well, hemorrhaging wallet.
  
 I sometimes miss my Lyr with the Siemens CCa and HD800s driven by the Uber DAC. It's damn fine too. Wishing I kept it for reference. Need a WE 421A?


----------



## NightFlight

ramaka said:


> I recently bought Chatham/TS 5998 from a fellow Head-fier and ordered a Tesla ECC802S from Ebay. How long does it take to burn them in? I have a Crack Amp with no speedball upgrade yet.




20-100 hrs


----------



## bigfatpaulie

I am so jealous of all you TS 5998 owners.  I've been through THREE of them and not has worked for me.


----------



## ben_r_

bigfatpaulie said:


> I am so jealous of all you TS 5998 owners.  I've been through THREE of them and not has worked for me.


 

 You have?! I have three that have worked fine through my testing. Though I only use one. The other two have just been sitting in my closet. What has been wrong with the ones youve had that didnt work?


----------



## MattTCG

I would guess that they are microphonic.


----------



## bigfatpaulie

Static or interference of some kind.  I can't recall what was wrong with the first one, but it was un-listenable. One just buzzed out of the right channel and the third one gets a rustling sound on one side.  Brush your finger on your ear hole (I know, ha ha....)  and that's the sound it makes.  The third one is the best one I've found so far.  At first it seemed to only do it with one tube and worked fine with everything else.  Now it does it with everything.  Because it worked (sorta) at the beginning, I ended up getting stuck with it.  So it sits on my desk and looks cool.


----------



## ben_r_

bigfatpaulie said:


> Static or interference of some kind.  I can't recall what was wrong with the first one, but it was un-listenable. One just buzzed out of the right channel and the third one gets a rustling sound on one side.  Brush your finger on your ear hole (I know, ha ha....)  and that's the sound it makes.  The third one is the best one I've found so far.  At first it seemed to only do it with one tube and worked fine with everything else.  Now it does it with everything.  Because it worked (sorta) at the beginning, I ended up getting stuck with it.  So it sits on my desk and looks cool.


 

 Dang, that sucks man, have you tried buying from these guys brand new: LINK Right on their front page they say they have Tung Sol / Chatham 5998's for $85. I got one of mine from them.


----------



## bigfatpaulie

Yeah, I'm pretty disappointed about it.  One was EBAY and two were from folks around here.  I could never find them NOS for sale.  It's a shame too.  I think my Crack is reaching retirement now, however.  Thanks for the link - I may take the plunge (yet again) and grab one while they are hot.


----------



## ben_r_

bigfatpaulie said:


> Yeah, I'm pretty disappointed about it.  One was EBAY and two were from folks around here.  I could never find them NOS for sale.  It's a shame too.  I think my Crack is reaching retirement now, however.  Thanks for the link - I may take the plunge (yet again) and grab one while they are hot.


 

 Yea VaccuumTubes.net usually has them in stock and they are brand new. Give them a try and sell your others for whatever you can get considering their condition.


----------



## bigfatpaulie

Thanks.  I'll give it a go.
  
 ...
  
 ...
  
 Wanna buy a semi-working 5998?  I kid!


----------



## FlySweep

spacequeen7 said:


> Received some new candles today and I'm just blown away how good 6085 E80CC/Amperex (PQ) is ,I have vintage 6922 and Bugle Boy Treble Clef ecc88 but this was unexpected ,it brought a lot of clean/sparkly highs to my 650s and the bass is just hard to explain ...highly recommend this tubes
> 
> P.S. thanks Jamie for  E80CC recommendation


 
  
 Ahh.. the Amperex 6085 is a terrific tube.  I think it's a perfect complement to the Tungsram E80CC.  The 6085 develops a midrange that's to die for... _to die for_.  Smooth, rich, warm.. but airy and wonderfully detailed.  I wouldn't have thought this type of sound would work with the HD650's signature/tuning.. but it does!
  
 I've always liked how E80CC/12BH7s have sounded in the Crack.. whether it's with the HD600 or 650.. but I far prefer rolling E80CC/12BH7s with the HD650.  The 600 impressed with them, but it was more of something I'd marvel at.. but not really enjoy, long term, when it came to music.  The 650 enables me to marvel at their performance and I find the 650 synergizes with them better (12BH7s tend to sound a bit forward).  The 650 also reveals the 12BH7's technical abilities better (bass performance, imaging, soundstage, and treble detail) than the 600 is capable of, IME.


----------



## NightFlight

> Static or interference of some kind.  I can't recall what was wrong with the first one, but it was un-listenable. One just buzzed out of the right channel and the third one gets a rustling sound on one side.  Brush your finger on your ear hole (I know, ha ha....)  and that's the sound it makes.  The third one is the best one I've found so far.  At first it seemed to only do it with one tube and worked fine with everything else.  Now it does it with everything.  Because it worked (sorta) at the beginning, I ended up getting stuck with it.  So it sits on my desk and looks cool.


 
  
 It is one of a few things:
  

oxidization on the tube pins
octal socket tolerance issue with 5998
oxidization on the 5998 pins
electrical issue - voltages
  
 There are a number of troubleshooting avenues here. You could clean out the socket and clean tube pins. My money is there because of nature of the sound your describing. I get that with new tubes all the time. I used to use 1000 grit sandpaper and alcohol. But now I use deoxit cleaner with cotton pads.  Also after I had my pins all cleaned up I had to clean out the sockets with some deoxit, which wasn't as easy. A pipecleaner with deoxit or contact cleaner if you can't get your hands on deoxit might work.  I've never been able to not clear up that random rushing sound with cleaning... but it can be electrical as well - though more unlikely.
    
 If you know someone with a crack, you could test the 5998 in their crack. Or ship it to a head-fier you know and trust.
 Maybe there's nothing wrong with the tubes and your octal socket is super picky or needs cleaning or even replacing. 
  
 Consider the above, the 5998 IMHO is worth it - Or I just lucked out with  my '57 Tung-Sol. It rocks.


----------



## NightFlight

flysweep said:


> Ahh.. the Amperex 6085 is a terrific tube.  I think it's a perfect complement to the Tungsram E80CC.  The 6085 develops a midrange that's to die for... _to die for_.  Smooth, rich, warm.. but airy and wonderfully detailed.  I wouldn't have thought this type of sound would work with the HD650's signature/tuning.. but it does!
> 
> I've always liked how E80CC/12BH7s have sounded in the Crack.. whether it's with the HD600 or 650.. but I far prefer rolling E80CC/12BH7s with the HD650.  The 600 impressed with them, but it was more of something I'd marvel at.. but not really enjoy, long term, when it came to music.  The 650 enables me to marvel at their performance and I find the 650 synergizes with them better (12BH7s tend to sound a bit forward).  The 650 also reveals the 12BH7's technical abilities better (bass performance, imaging, soundstage, and treble detail) than the 600 is capable of, IME.


 
  
 The one 12BH7 that randomly came my way and I tried has a "Rogers" Canadian re-label I think. It sounds nice, but a bit muddied up I realized after the initial warm and fuzzies wore off. With the muddy presentation the magic headphones are capable of is missing.  Perhaps a bit too much gain I think. I seem to prefer a slightly warm of neutral, punchy, technical tube that can show off a soundstage where layering is realized. These days if a new tube hasn't got that sort of potential, I move on. 
  
 I've been eyeballing the Tesla 802S and various E80CC on here. I've yet to settle on make and year for a purchase. Any suggestions?


----------



## bigfatpaulie

Thanks NF,
  
 Cleaning the pins and the socket was the first thing I tried (in hopes).  I supposed I can give it another go.  It can't hurt right?
  
 I was going to bring it the meet but I missed my shot as we were away on vacation and I wasn't check Head-fi when JAG was asking people to register with him 
  
 I have half a mind to crash the meet (but I won't) because I think it's going be a great one!


----------



## MattTCG

Got the Tesla in yesterday. It's wonderful and pairs very well with the 5998. Very happy with it.


----------



## ramaka

matttcg said:


> Got the Tesla in yesterday. It's wonderful and pairs very well with the 5998. Very happy with it.


 
  
 +1 on that...just the 5998 is such a huge step up...kicking myself for having waited so long to upgrade.


----------



## cheneric

so heppy 
	

	
	
		
		

		
			





 
  
 https://www.youtube.com/watch?v=AtlplvhDSR0


----------



## JamieMcC

Great to see your table now has a rather smart looking Crack sitting on it, neat reflection of you taking the pic!


----------



## MattTCG

And I'm so heppy for you!! haha
  
 Looks great...now you're ready to roll some tubes.


----------



## grrraymond

I do really know that I shouldn't be running this E80CC through the stock Crack but it sounds SO GOOD. I really can't go back now...I've ordered the SB and I'll just wait it out.
  
 Anyone who's thinking about it, I can't recommend this tube enough with the 5998. All the detail, imaging and soundstage but with that rubbery tube warmth.
  
 Basically, it fills in all the low mids, keeps the low end nice and chunky and livens everything else up top.


----------



## NightFlight

jamiemcc said:


> Great to see your table now has a rather smart looking Crack sitting on it, neat reflection of you taking the pic!


 
  
 I was just going to say I could tell he's wearing his Senns while taking the pic of the bottlehead badge.
  
 I just finally got around to doing the finish on mine. I don't think its nearly so dark as the one above. The gloss spray I coated the stain with still stinks a bit when I'm back to the house after being away for the day. Not nearly so glossy as to cast a reflection either. I mean I only did 5-6 coats...1/3 to half I can I'd guess.


----------



## NightFlight

bigfatpaulie said:


> Thanks NF,
> 
> Cleaning the pins and the socket was the first thing I tried (in hopes).  I supposed I can give it another go.  It can't hurt right?
> 
> ...


 
  
 Oh hey! Your in Taranta! How handy are you with a soldering iron? Assuming you reflowed everything? Have you posted for help on the BH forums?


----------



## bigfatpaulie

Haha.  Yup, we are neighbors!  
  
 I'm fairly handy with a soldering iron.  I wouldn't tackle a KGSSHV or anything, but have been tinkering for 12 years or so.  At first I thought it may be the amp but it works just fine with all other tubes.


----------



## NightFlight

ben_r_ said:


> Dang, that sucks man, have you tried buying from these guys brand new: LINK Right on their front page they say they have Tung Sol / Chatham 5998's for $85. I got one of mine from them.


 
  
 Just gave them a call from the 800 number on their front page to see if they would be willing to reveal what years they have in stock for the Tung-Sol. Said he didn't know how to read the codes. So I says "Its 322 then the year, then the week".  The guy replies "They're all the way in the back".  I get it, they don't have time.  
  
 ... So, I guess I don't have time to purchase them. *sigh*.
  
 Its a stellar price. I've hear it said the year doesn't matter with this make of tube and the differences are so minor it doesn't matter.  I don't believe it. Small differences add up to big ones. 1+1 still equals 2 the last time I checked.


----------



## bigfatpaulie

Out of curiosity, of the input tubes they have, would be recommend (mind as well grab one)?


----------



## spacequeen7

matttcg said:


> Got the Tesla in yesterday. It's wonderful and pairs very well with the 5998. Very happy with it.


 
 Nice ..
 that little tube pairs well with all power tubes ...I recently acquired Bendix red bank (pretty difficult tube to pair with another)  and so far Tesla is the frontrunner


----------



## FlySweep

grrraymond said:


> I do really know that I shouldn't be running this E80CC through the stock Crack but it sounds SO GOOD. I really can't go back now...I've ordered the SB and I'll just wait it out.
> 
> Anyone who's thinking about it, I can't recommend this tube enough with the 5998. All the detail, imaging and soundstage but with that rubbery tube warmth.
> 
> Basically, it fills in all the low mids, keeps the low end nice and chunky and livens everything else up top.


 
  
 I can't recommend Thom Rotella's excellent (jazz) album, "A Day In The Life," enough.  It's a great album regardless of gear used.. but I find it to sound _especially_ impressive with the SB'ed Crack/650.. my tube of choice?  The Amperex PQ 6085/E80CC.  The album appears to be mixed & mastered well.. the 6085 has an absolutely _terrific_ soundstage.. you cal also expect one of the finest versions of the Amperex "house sound" (that I've heard).. it all makes for what feels like an utterly live performance via the HD650.  Superb dynamics, layering, tonal richness, imaging, etc.  I'm supposed to send this tube to @MattTCG to audition.. but I just can't seem to pull it out of the Crack... sorry bud.


----------



## cheneric

Looking to get the 6AS7G, TS 5998, and the e80cc. What kind of prices am I looking at and where? Sorry if this has been asked before. Just built my crack


----------



## JamieMcC

cheneric said:


> Looking to get the 6AS7G, TS 5998, and the e80cc. What kind of prices am I looking at and where? Sorry if this has been asked before. Just built my crack


 

 Knowing where you are based USA, Europe etc would help with suggestion.


----------



## MattTCG

flysweep said:


> I can't recommend Thom Rotella's excellent (jazz) album, "A Day In The Life," enough.  It's a great album regardless of gear used.. but I find it to sound _especially_ impressive with the SB'ed Crack/650.. my tube of choice?  The Amperex PQ 6085/E80CC.  The album appears to be mixed & mastered well.. the 6085 has an absolutely _terrific_ soundstage.. you cal also expect one of the finest versions of the Amperex "house sound" (that I've heard).. it all makes for what feels like an utterly live performance via the HD650.  Superb dynamics, layering, tonal richness, imaging, etc. * I'm supposed to send this tube to @MattTCG to audition.. but I just can't seem to pull it out of the Crack... sorry bud.*


 
  
 That's okay. Just understand, there are a few who have done me wrong here and I had to make a little doll in their honor to harass. We don't have to go there do we?


----------



## cheneric

jamiemcc said:


> Knowing where you are based USA, Europe etc would help with suggestion.


 
  
 USA, California


----------



## JamieMcC

cheneric said:


> Looking to get the 6AS7G, TS 5998, and the e80cc. What kind of prices am I looking at and where? Sorry if this has been asked before. Just built my crack


 
  
http://www.vacuumtubes.net/ have some 5998's for $85 each
  
http://tctubes.com/ I have used several times now a little more expensive but always good service and a top notch tube, Tyler the owner is always very helpful.
  
 ebay always a good source but also pot luck if not tested best to buy from sellers with 100% feedback, always the potential to grab a bargain if your willing to take a risk on a untested tube.


----------



## FraGGleR

cheneric said:


>


 
 Ack!  Get some cushioning on that banana hanger!


----------



## cheneric

fraggler said:


> Ack!  Get some cushioning on that banana hanger!


 
 Damage has been done. 
  
 Does anyone know where I can get 1 piece of little foam thingy? I've seen it at a meetup before, but I can't imagine paying for shipping for a little foam piece.
  
 Right now I have electrical tape wrapped around it. It's better.


----------



## cheneric

jamiemcc said:


> http://www.vacuumtubes.net/ have some 5998's for $85 each
> 
> http://tctubes.com/ I have used several times now a little more expensive but always good service and a top notch tube, Tyler the owner is always very helpful.
> 
> ebay always a good source but also pot luck if not tested best to buy from sellers with 100% feedback, always the potential to grab a bargain if your willing to take a risk on a untested tube.


 
 Thanks for the info. Probably going to grab the tubes from vacuumtubes.net. Looks like the 6AS7G is on there too. Should I grab that also? If so, which brand? Seems like theres a good contrast between the 5998 and the 6AS7G.


----------



## Armaegis

cheneric said:


> Damage has been done.
> 
> Does anyone know where I can get 1 piece of little foam thingy? I've seen it at a meetup before, but I can't imagine paying for shipping for a little foam piece.
> 
> Right now I have electrical tape wrapped around it. It's better.


 
  
 I just cut up a pool noodle from the dollar store.


----------



## FraGGleR

armaegis said:


> I just cut up a pool noodle from the dollar store.


 
 Beer/soda holders also work well. You can get some nice thick and soft ones for $1 at Michaels if you have one near you.


----------



## cheneric

fraggler said:


> Beer/soda holders also work well. You can get some nice thick and soft ones for $1 at Michaels if you have one near you.




thank you! went to Michaels and found it on clearance!!


----------



## DefQon

syphen606 said:


> Can anyone identify this tube? There is no manufacturer markings that I can see, only a faint 6080WB.  The tube was filthy when I opened it, but thankfully a microfibre and a touch of windex cleaned it right up.


 
  
 That tube is a Sylvania 6080WB, the faint etched typeset and position, internal structure gives it a way had one myself. From afar observation one can see it as a Raytheon Jan 6080 but the Raytheon's have a slight different structure on the cathode plates.
  
 Btw, what are you going to use to protect against fingerprints and easy scuffs on the spray painted metal plates and trafo bell cover?


----------



## grrraymond

I've solved my E80CC problem by picking up a Mullard CV4003. Hats off to those who've mentioned it in this thread, sounds very much like the E80CC, in fact, it sounds better (!), more open, and it won't burn down my house.


----------



## DefQon

Pinched top with 4 grooves and flashing getter on power up?


----------



## syphen606

defqon said:


> That tube is a Sylvania 6080WB, the faint etched typeset and position, internal structure gives it a way had one myself. From afar observation one can see it as a Raytheon Jan 6080 but the Raytheon's have a slight different structure on the cathode plates.
> 
> Btw, what are you going to use to protect against fingerprints and easy scuffs on the spray painted metal plates and trafo bell cover?


 
  
 Thanks!
  
 Hadn't really thought about it. Its rustoleum primer + paint. It is a textured finish and not a gloss. It hasn't seem to shown finger prints or scuffs yet. What do you recommend?


----------



## roguegeek

Got mine in yesterday and starting my build today. Good luck to us all.


----------



## Doc B.

syphen606 said:


> Thanks!
> 
> Hadn't really thought about it. Its rustoleum primer + paint. It is a textured finish and not a gloss. It hasn't seem to shown finger prints or scuffs yet. What do you recommend?




Just let it harden for a while. It seems to take maybe a week for most rattle can paint paint to polymerize enough to be resistant to scratches and scuffs. Some types of paint can be accelerated a little by heating, but I have never had much luck with that.


----------



## jgreen16

is there any benefit to adding a coat or two of clearcoat?


----------



## FraGGleR

cheneric said:


> thank you! went to Michaels and found it on clearance!!


 
 Lucky find!


----------



## roguegeek

Attempting to organizing all of my parts right now. I think I may be missing one and I'm having some difficulty distinguishing the differences between some of the resistors and capacitors. Is there any kind of visual guide out there to see what these parts are so I can tell the difference?


----------



## Doc B.

jgreen16 said:


> is there any benefit to adding a coat or two of clearcoat?




I certainly won't hurt to lay clear over a finish that it is compatible with. But I suspect when people ask about clear coat they are probably thinking of the very rugged type used on cars. That stuff is urethane and while available in rattle cans it is about $30 a can and has a very limited pot life once activated.


----------



## roguegeek

roguegeek said:


> Attempting to organizing all of my parts right now. I think I may be missing one and I'm having some difficulty distinguishing the differences between some of the resistors and capacitors. Is there any kind of visual guide out there to see what these parts are so I can tell the difference?


 
  
 Alright, I am definitely missing the #8 solder tab. I'm hoping I can just run to any competent electronics store and they'll have one because I really would hate to wait to have it shipped out to me. That's one issue.
  
 The other issue is just my stupidity. I can tell the difference in the capacitors, but I have no idea how to read these resistors. Yeah, I tried to look up how to online, but it's just not making sense with these.
  

  
 I'm guessing the one on the right is the 270KΩ 1W metal film resistor since there should only be one. Now I just need to figure out which between the two on the left and two in the center is the 22.1KΩ 3/4W metal film resistor and 2.49KΩ 1/4W metal film resistors.
  
 Help!


----------



## Sonido

roguegeek said:


> Alright, I am definitely missing the #8 solder tab. I'm hoping I can just run to any competent electronics store and they'll have one because I really would hate to wait to have it shipped out to me. That's one issue.
> 
> The other issue is just my stupidity. I can tell the difference in the capacitors, but I have no idea how to read these resistors. Yeah, I tried to look up how to online, but it's just not making sense with these.
> 
> ...



Unnecessary really. Just go by the pictures. You should be able to discern it.


----------



## roguegeek

Well, I used a resistor calculator and found the left two (red-red-brown-red-brown) to be the 22.1KΩ resistors. I'm guessing that means the center two are the 2.49KΩ resistors.
  
 Ugh, still missing that #8 solder tab, which is unfortunately used at the very beginning of the build. Which means I'm stuck right now. Radio Shack? Fry's? I'm hoping someone has it because I don't really want to wait a couple of days to move on.


----------



## syphen606

doc b. said:


> Just let it harden for a while. It seems to take maybe a week for most rattle can paint paint to polymerize enough to be resistant to scratches and scuffs. Some types of paint can be accelerated a little by heating, but I have never had much luck with that.


 
  
 I've noticed that its not 'fully cured' yet. When the amp is hot, its not tacky to the point of leaving finger prints but the plate doesn't feel fully dry. At room temp its a nice smooth happy finish. It does seem to be getting better as you suggested.


----------



## DefQon

syphen606 said:


> Thanks!
> 
> Hadn't really thought about it. Its rustoleum primer + paint. It is a textured finish and not a gloss. It hasn't seem to shown finger prints or scuffs yet. What do you recommend?


 
 Np
  
 I don't know was wondering what you were going to use. I originally spray painted my metal plate gloss black, that left scuffs then i sanded it down and went with matt black, matt black didn't turn out so good so I went with gloss black 3M vinyl for car's and left it since but no clue if it can stand the heat. It's a second Crack kit I haven't finished building in a long time now as I've been focusing on the aesthetic side then completing the amp. Was going to powdercoat but very costly here for small job lots.


----------



## diaBoliQu3

doc b. said:


> Just let it harden for a while. It seems to take maybe a week for most rattle can paint paint to polymerize enough to be resistant to scratches and scuffs. Some types of paint can be accelerated a little by heating, but I have never had much luck with that.


 
 Hi Doc, I sent you a PM regarding tube. Is there any solution for this?


----------



## Doc B.

sonido said:


> Unnecessary really. Just go by the pictures. You should be able to discern it.




I might use an ohmmeter, but maybe that's cheating?


----------



## Doc B.

diaboliqu3 said:


> Hi Doc, I sent you a PM regarding tube. Is there any solution for this?




replacementparts@bottlehead.com is the best way to get a replacement part. I am not always at the office and not very consistent in my checking of my PMs, but a request sent to that address will go right to the person who handles replacements. We operate Monday thru Friday, so those emails are checked first thing Monday morning and the parts shipped right away.


----------



## diaBoliQu3

doc b. said:


> replacementparts@bottlehead.com is the best way to get a replacement part. I am not always at the office and not very consistent in my checking of my PMs, but a request sent to that address will go right to the person who handles replacements. We operate Monday thru Friday, so those emails are checked first thing Monday morning and the parts shipped right away.


 
 Thank you. I don't know tho email who so I PM your head-fi profile hopefully you can direct me where to go.
  
 Thanks again sir.


----------



## roguegeek

Welp, got it all put together in one day. This included staining the wood and painting. I think it came out ok. The only thing that's missing is connecting the ground from the AC to the chassis because the #8 solder tab was missing. Sent over an email and hopefully they can get that part over as soon as possible. Tried to go find it from some local stores today, but no one carried anything like it. I'll try a couple more tomorrow and then, hopefully, I'll be able to test it.


----------



## MattTCG

Pics!!


----------



## Klots

Hi! Finished my Crack yesterday and had a listen. There are few things that disturb me a little. I try to give as much information as I can. 

 When I finished soldering I did the resistance checks (every measurement was correct) and then voltage checks (also every measurment was correct). When I turn the amp on (with no DAC and laptop connected to it) and put my ear near the crack it hums and when I connect my headphones (HD700) in then the same hum comes through them. When I connect my laptop and dac (schiit modi) to it and turn on the music I hear crackling/popping. (like an old vinyl). Both the hum and crackling/popping sound is in both channels. I re-heated all the joints 3 times and everything is still the same. The hum increases when I turn the volume from 0% to 100%. I add some pics also. If anyone sees anything problematic or have some ideas what to test or measure then please share your thoughts. 


 So, this is how my crack turned out 
	

	
	
		
		

		
			






  





 And now the other pictures


----------



## syphen606

roguegeek said:


> Welp, got it all put together in one day. This included staining the wood and painting. I think it came out ok. The only thing that's missing is connecting the ground from the AC to the chassis because the #8 solder tab was missing. Sent over an email and hopefully they can get that part over as soon as possible. Tried to go find it from some local stores today, but no one carried anything like it. I'll try a couple more tomorrow and then, hopefully, I'll be able to test it.




A crimp on connection would work - the ones that have a round eye. You could then use a longer bolt and just use a nut to attach it to the chassis.


----------



## spacequeen7

Does anyone have both tubes-13D5 Brimar longplate and Mullard CV4003 and do a little comparison please  ?
  
 EDIT; CV4003 is pretty pricey and from this description 13D5 could be a better value 
 I have one 13D5 and it does sound very good ,was wondering if this is true 


> These are incredible tubes with a fine soundstage, clean top end with a touch of midrange warmth. Like the famed CV4003 but with more layers of detail and more delicate
> 
> quote from BRENT JESSEE RECORDING & SUPPLY, INC.


----------



## JamieMcC

klots said:


> Hi! Finished my Crack yesterday and had a listen. There are few things that disturb me a little. I try to give as much information as I can.
> 
> When I finished soldering I did the resistance checks (every measurement was correct) and then voltage checks (also every measurment was correct). When I turn the amp on (with no DAC and laptop connected to it) and put my ear near the crack it hums and when I connect my headphones (HD700) in then the same hum comes through them. When I connect my laptop and dac (schiit modi) to it and turn on the music I hear crackling/popping. (like an old vinyl). Both the hum and crackling/popping sound is in both channels. I re-heated all the joints 3 times and everything is still the same. The hum increases when I turn the volume from 0% to 100%. I add some pics also. If anyone sees anything problematic or have some ideas what to test or measure then please share your thoughts.


 
  
 The Crack is quiet good at picking up outside interference try rerouting some of you cables away from transformers, extension leads, wifi-routers etc and also put some twists in the rca cables that go from your dac to the amp. This cured the hum issues I had with my amp. Not sure about the crackling and popping perhaps a loose rca connection or a headphone jack connection issue? The bottlehead forum is the best place to resolve any teething problems.


----------



## Klots

jamiemcc said:


> The Crack is quiet good at picking up outside interference try rerouting some of you cables away from transformers, extension leads, wifi-routers etc and also put some twists in the rca cables that go from your dac to the amp. This cured the hum issues I had with my amp. Not sure about the crackling and popping perhaps a loose rca connection or a headphone jack connection issue? The bottlehead forum is the best place to resolve any teething problems.


 


 I already tested with no routers, mobile phones, computers etc being around, no change. The rca cables dont have to be attached for the hum to appear. Headphone jack and rca connections are great. Maybe a bad tube?


----------



## ben_r_

klots said:


> I already tested with no routers, mobile phones, computers etc being around, no change. The rca cables dont have to be attached for the hum to appear. Headphone jack and rca connections are great. Maybe a bad tube?


 

 I have found that some tubes can cause hum or noise. More often it has happened with 6080 tubes Ive tried.


----------



## roguegeek

syphen606 said:


> A crimp on connection would work - the ones that have a round eye. You could then use a longer bolt and just use a nut to attach it to the chassis.


 
  
 How about wrapping the wire around the bolt where the solder lug would have been installed and tightening that down?


----------



## spacequeen7

klots said:


> I already tested with no routers, mobile phones, computers etc being around, no change. The rca cables dont have to be attached for the hum to appear. Headphone jack and rca connections are great. Maybe a bad tube?


 
 I had few noises coming earlier ,..rerouted some wires around driver socket and most of it's  gone now ,the hum is related to tube -I would suggest swapping /trying another power tube ..5998 or 6080 doesn't matter it's about how micro-phonic particular tube is
 before

  
  

  
  
 and after


----------



## JamieMcC

klots said:


> The rca cables dont have to be attached for the hum to appear.


 
  
 Same with mine.
  
 Twist them up and give a try, it takes less than a minute to do so and its a easy thing to rule out, it just might work also. Like I said it worked for me and I know a few others who have resolved their hums by doing this.


----------



## Klots

jamiemcc said:


> Same with mine.
> 
> Twist them up and give a try, it takes less than a minute to do so and its a easy thing to rule out, it just might work also. Like I said it worked for me and I know a few others who have resolved their hums by doing this.


 
 I will try that when I get my new rca cables next week. 


spacequeen7 said:


> I had few noises coming earlier ,..rerouted some wires around driver socket and most of it's  gone now ,the hum is related to tube -I would suggest swapping /trying another power tube ..5998 or 6080 doesn't matter it's about how micro-phonic particular tube is
> before
> 
> 
> ...


 
  
  
 6AS7/6AS7G/6AS7GA would be ok? I have to buy tubes from europe because no customs then and faster delivery.


----------



## spacequeen7

^^ try posting on BH forum and see what the experts have to say before spending more $ ,you might have to check your voltages 
 http://bottlehead.com/smf/index.php/board,24.0.html


----------



## Klots

spacequeen7 said:


> ^^ try posting on BH forum and see what the experts have to say before spending more $ ,you might have to check your voltages
> http://bottlehead.com/smf/index.php/board,24.0.html


 

 Thanks for the suggestion. Already made a post there.


----------



## sotto123

I live in England but if I pick up a Bottlehead Crack from the USA, running on 120 V, would a 120 V to 240 V transformer be all that is needed for it to work? Any damage likely to occur?


----------



## JamieMcC

sotto123 said:


> I live in England but if I pick up a Bottlehead Crack from the USA, running on 120 V, would a 120 V to 240 V transformer be all that is needed for it to work? Any damage likely to occur?


 
 On the bottlehead crack product page you will see a option to select a 240 transformer when ordering at no extra cost. The kit then arrives with transformer specified for uk use.


----------



## sotto123

jamiemcc said:


> On the bottlehead crack product page you will see a option to select a 240 transformer when ordering at no extra cost. The kit then arrives with transformer specified for uk use.


 
  
 I noticed that, but I'm talking about if a buy a used one from the USA. Would something like this be what I would need - http://www.ebay.co.uk/itm/45W-45-WATT-STEP-DOWN-TRANSFORMER-UK-220V-230V-240V-TO-USA-100V-110V-120V-/121163510741
  
 DIY and electronics are two things I know very, very little about.


----------



## Schroeder77

> If anyone sees anything problematic or have some ideas what to test or measure then please share your thoughts.


 
  You chose such a beautiful color for the wood! It looks great.
  
 The braiding of your three wires from the pot to the RCA jacks doesn't seem to be as tight as suggested in the manual. That may make it more susceptible to interference as a result. I have no idea if it would really affect the sound so much, but it's the only thing I thought of as I looked at the pictures.
  
 I hope you find the problem soon so it sounds as lovely as it looks!


----------



## Zashoomin

sotto123 said:


> I noticed that, but I'm talking about if a buy a used one from the USA. Would something like this be what I would need - http://www.ebay.co.uk/itm/45W-45-WATT-STEP-DOWN-TRANSFORMER-UK-220V-230V-240V-TO-USA-100V-110V-120V-/121163510741
> 
> DIY and electronics are two things I know very, very little about.


 
 I personally use this guy as a step up and step down transfromer.  It works wonderfully and as far as I can tell is pretty silent (if there are in fact noisy ones that is)  http://www.amazon.com/gp/product/B0022TOK2Q/ref=oh_details_o00_s00_i02?ie=UTF8&psc=1
  
 Also I still suggest you build one.  You honestly don't need to know much about DIY or electronics to do this.  That is how good the instruction manual is.   Cheers to bottlehead for putting the instruction manual together like the crack's for every single kit they offer.


----------



## Klots

schroeder77 said:


> You chose such a beautiful color for the wood! It looks great.
> 
> The braiding of your three wires from the pot to the RCA jacks doesn't seem to be as tight as suggested in the manual. That may make it more susceptible to interference as a result. I have no idea if it would really affect the sound so much, but it's the only thing I thought of as I looked at the pictures.
> 
> I hope you find the problem soon so it sounds as lovely as it looks!


 

 Thank you! It is dark walnut. I may braid it more tightly and test if that changes anything. If you leave that little crackle to a side it sounds as lovely as it looks


----------



## roguegeek

Alright, got it all tested and working. Put a real quick rig together in on my coffee table to have an initial listen to. Macbook Pro to Magni to Crack to HD 800. Dark grey hammered paint on the chassis. Aged walnut for the wood. Crappy pic, but whatever. I'll throw up better ones later.
  

  
 I got the Speedball upgrade as well, but decided to not throw it on their yet because I wanted to hear the stock unit for a while. Not initially blown away by the sound as I feel like I have a better amp for every can I've thrown at it so far, but I kinda expected that. I really picked it up because it sounded like a fun project and it definitely was, so I'm very happy so far. Already drawing up ideas of another unit with a fully custom chassis.


----------



## MattTCG

I have a walnut base also and really like it. I like the paint on the plate, looks good. What kind of IC's are you using there? And what is your favorite amp with the hd800?
  
 thanks...


----------



## sotto123

zashoomin said:


> I personally use this guy as a step up and step down transfromer.  It works wonderfully and as far as I can tell is pretty silent (if there are in fact noisy ones that is)  http://www.amazon.com/gp/product/B0022TOK2Q/ref=oh_details_o00_s00_i02?ie=UTF8&psc=1
> 
> Also I still suggest you build one.  You honestly don't need to know much about DIY or electronics to do this.  That is how good the instruction manual is.   Cheers to bottlehead for putting the instruction manual together like the crack's for every single kit they offer.


 
  
 Perfect. Thanks. I'll be on the lookout for a similar one that is sold in the UK.


----------



## NightFlight

roguegeek said:


> Alright, got it all tested and working. Put a real quick rig together in on my coffee table to have an initial listen to. Macbook Pro to Magni to Crack to HD 800. Dark grey hammered paint on the chassis. Aged walnut for the wood. Crappy pic, but whatever. I'll throw up better ones later.
> 
> 
> 
> I got the Speedball upgrade as well, but decided to not throw it on their yet because I wanted to hear the stock unit for a while. Not initially blown away by the sound as I feel like I have a better amp for every can I've thrown at it so far, but I kinda expected that. I really picked it up because it sounded like a fun project and it definitely was, so I'm very happy so far. Already drawing up ideas of another unit with a fully custom chassis.


 
  
 Tubes, mods and source will get you there.


----------



## roguegeek

matttcg said:


> I have a walnut base also and really like it. I like the paint on the plate, looks good. What kind of IC's are you using there? And what is your favorite amp with the hd800?
> 
> thanks...



The cables are the ones you buy direct from Schiit. I forgot who supplies them. The Lyr isn't bad with the HD 800, but it's not great either. Probably pick up a Taurus MkII soon.


----------



## roguegeek

nightflight said:


> Tubes, mods and source will get you there.



We'll see. I tend to prefer a more neutral and transparent signature, but I'm going to try and push the Crack towards a warm, tubey, laid back signature since most of my other equipment isn't that at all. What tubes are recommended for that direction? I'm not ready for mods outside of the Speedball just yet and my sources are very good already.


----------



## Sonido

roguegeek said:


> We'll see. I tend to prefer a more neutral and transparent signature, but I'm going to try and push the Crack towards a warm, tubey, laid back signature since most of my other equipment isn't that at all. What tubes are recommended for that direction? I'm not ready for mods outside of the Speedball just yet and my sources are very good already.



If you want a warmer tilt with impactful bass like that of planars, add a Quickie with PJCCS upgrade to the chain. Great pairing imo.


----------



## skeptic

For warm and laid back, I'd recommend a a good quiet chatham mil spec 6080 in the back (for a little more bass bloom and a little less brightness than the higher tranconductance lower output impedance options like 5998) and an Amperex bugle boy up front. For a slightly better sounding, but still warm combo with hd800s, install your speedball and then run a Tung Sol 12BH7 in front.


----------



## roguegeek

sonido said:


> If you want a warmer tilt with impactful bass like that of planars, add a Quickie with PJCCS upgrade to the chain. Great pairing imo.


 


skeptic said:


> For warm and laid back, I'd recommend a a good quiet chatham mil spec 6080 in the back (for a little more bass bloom and a little less brightness than the higher tranconductance lower output impedance options like 5998) and an Amperex bugle boy up front. For a slightly better sounding, but still warm combo with hd800s, install your speedball and then run a Tung Sol 12BH7 in front.


 
 Thanks. Will be looking into this.


----------



## MattTCG

sonido said:


> If you want a warmer tilt with impactful bass like that of planars, add a Quickie with PJCCS upgrade to the chain. Great pairing imo.


 
  
 Very interesting.


roguegeek said:


> The cables are the ones you buy direct from Schiit. I forgot who supplies them. The Lyr isn't bad with the HD 800, but it's not great either. Probably pick up a Taurus MkII soon.


 
  
 I was really fishing to know what you thought of the hd800 with the crack.


----------



## Klots

Solved my background noise and crackling sound problem. It was just a small silly USB port 
	

	
	
		
		

		
		
	


	




 Now I can enjoy my crack even more


----------



## syphen606

Finally tried a couple different tubes in the stock crack.
  
 Sylvania 6080WB, Phillips 6080WB and a RCA 6AS7G black plate. 
 Sound differences don't seem huge but the Phillips 6080WB does seem to have a tiny bit more clarity in the trebles and top end. The 6AS7G takes the aesthetic looks for me  Too bad looks aren't everything. Love the big tube.
  
 The 6AS7G is much more microphonic, but as long as your not playing with the amp its good.


----------



## lost&confused

I've only had my amp a few weeks now and I've bought a tung sol 5998 and mullard CV491 12AU7 K61 ....this mullard is meant to be a really good tube but I prefer the stock tubes!  ...    it came with an RCA Jan 6080 and a hewlett packard 5963 (Orange writing) and I really like this sound,  The tung sol doesn't sound that good to me (odd me I know   it sounds heavy wooly bassy good detail but not so fun sounding kinda  like other amps I've tried  not tube amps.
  
 Its the same with the mullard tube I like the hewlett packard more   
  
 My bottlehead crack is stock but ordered the speedball which I'm not sure I'm gonna install now ..well for the moment.  I just love this combo I'm using now and I notice a massive difference when I change tubes on my crack all different combos.
  
 The amps working really well I have no hums or crackles  its plugged into creative ZxR sound card on a  desktop computer sitting 1 foot away from the pc ,  I only have noise if I have the volume at max and its only faint.
  
 I do have a small problem with noise if  the volume turned up really high (much higher than I listen tho)  If i scroll with my mouse on web pages I hear a static noise but it doesn't really bother me, its right next to my pc! its from my sourse soundcard.
  
  
 Love this amp with stock tubes for now everything sounds ace on my old HD600's even music on youtube !
  
 Thanks


----------



## lost&confused

And sotto you should build one!  Its really easy the instructions are excellent,  I've never soldered a thing before doing this amp    The pictures in the manual are great and its fun building her then when you wanna mod it you  no how.
  
 Go for it"!!  Good fun


----------



## Klots

How about GE 6AS7GA with stock crack? Anyone uses one and can comment how does it sound?


----------



## sotto123

lost&confused said:


> And sotto you should build one!  Its really easy the instructions are excellent,  I've never soldered a thing before doing this amp    The pictures in the manual are great and its fun building her then when you wanna mod it you  no how.
> 
> Go for it"!!  Good fun


 
  
 I purchased an assembled one from a fellow head-fier last night 
	

	
	
		
		

		
			




  
 Do you guys know what wattage the Crack uses? I was going to get a transformer that can support up to 300w but it's probably unnecessary. They're more expensive and much bulkier too. Would I be good to go with a 75w or 100w one?


----------



## lost&confused

Lazy!    I think its 120v sotto  but dont quote me on that ...someone will come along and comfirm it.
  
 Whats your crack had done to it then? speedball  upgrade ? You in the UK then ?  I was going to buy a pre built one from another member but decided to go for it!
  
  I'm really not sure I wanna install the speedball     I think I'll order the standard parts to put it back to standard if I dont like the speedball ...but everyone says it makes biggest difference installing the speedball.  But loads of ppl say the tungsol is great tube.....I'll  give the other tubes another try. 
  
 Maybe the tungsol sounds better with the speedball upgrade but I've read that with the speedball you dont notice tube sound changes as much than with the standard crack.
  
 have fun!


----------



## Tequilasunriser

lost&confused said:


> I've read that with the speedball you dont notice tube sound changes as much than with the standard crack.




I've read this as well too, can anyone chime in with some science on this? Subjective info would be nice too.

I like the way my Crack sounds now, not sure I want to install the SB.


----------



## skeptic

There's nothing about the speedball to dislike, IMO.  Crack's overall signature stays the same.  You just get a blacker background, tighter bass, and reduced voltage sag.  Loading your tubes with constant current is never a bad thing in headphone amps.  
  
 As I understand it, akin to running in class A, it reduces the amp's overall efficiency - so you're unlikely to see it in a whole lot of speaker amps, but it is a nice improvement to sq.


----------



## sotto123

lost&confused said:


> Lazy!    I think its 120v sotto  but dont quote me on that ...someone will come along and comfirm it.
> 
> Whats your crack had done to it then? speedball  upgrade ? You in the UK then ?  I was going to buy a pre built one from another member but decided to go for it!
> 
> ...


 
  
 Yeah, I'm in the UK. Got myself one with the speedball upgrade and Sino 6AS7G as an extra. Really looking forward to how it will sound with my T1's, meant to be a great match.


----------



## lost&confused

Sure it will sound real nice with those headphones!  I've never heard the T1's but one day I'l try them, I'm big into comfort so important to me, the weight and cable  .  I was going to buy new headphones but thought I'd try this crack amp with all the hype I've read and glad i did  stopped me spending loads on new headphones.
  
 Thanks Sceptic for the info think I'll install it when it comes  have time.
  
 How you running the amp then sotto?  I must try and plug these into my record player some day but hardly ever use it now,  I love searching youtube for music  and have loads of mp3s , sounds really nice with my hd600s.


----------



## Doc B.

skeptic said:


> There's nothing about the speedball to dislike, IMO.  Crack's overall signature stays the same.  You just get a blacker background, tighter bass, and reduced voltage sag.  Loading your tubes with constant current is never a bad thing in headphone amps.
> 
> As I understand it, akin to running in class A, it reduces the amp's overall efficiency - so you're unlikely to see it in a whole lot of speaker amps, but it is a nice improvement to sq.


 
 It doesn't have as much to do with efficiency loss from running class A (it's already doing that) as the need for additional supply voltage headroom, and that is only in the case where a constant current source is used with a voltage amp rather than a cathode follower like the Crack uses. For example you can put an output transformer primary or a plate loading choke above a traditional 2A3 voltage amp output circuit and have B+ supply of maybe 300V. If you use a constant current source instead you might need a 450V supply. That plate load CCS will need to dissipate additional heat beyond what the tube and cathode is dissipating, much more than a choke would running at a lower B+. But with a CF this is a non issue because the CCS is just standing in for the cathode load resistor. The only increase in dissipation is a wee bit for the bias string.
  
 From a technical standpoint the main difference of using a C4S constant current source is an addtional 60dB or so of power supply ripple rejection (thus the descriptions of a blacker background) and a distortion curve that stays linear with increased power up to a point further than it would with a lower impedance load like a resistor or choke. So distortion comes in later, that is when the signal is a little higher than it would be without the CCS. And when it does happen distortion is at a high enough level that it is less subtle unless you are careful to keep that stage linear all the way up to where the following stage is distorting first, which is definitely doable. So if you keep the signal level such the the tube's output stays within the linear zone the amp sounds more dynamic - and that's pretty easy to do when you are running headphones. My opinion is that cathode followers don't really sound that great without a CCS under them to make them more linear and I much prefer a Crack with the Speedball. 
  
 Anyway all of this hopefully helps to explain why the tube becomes less influential in the overall sonic signature when a CCS is used. It has less power supply noise for the tube to add color with, and it is running in a more linear fashion, i.e. closer to the ideal for the particular tube type, as the signal thru it increases.


----------



## Sonido

doc b. said:


> Anyway all of this hopefully helps to explain why the tube becomes less influential in the overall sonic signature when a CCS is used. It has less power supply noise for the tube to add color with, and it is running in a more linear fashion, i.e. closer to the ideal for the particular tube type, as the signal thru it increases.



Alas we come full circle to solid state where components should not impart its own sound.


----------



## sotto123

lost&confused said:


> Sure it will sound real nice with those headphones!  I've never heard the T1's but one day I'l try them, I'm big into comfort so important to me, the weight and cable  .  I was going to buy new headphones but thought I'd try this crack amp with all the hype I've read and glad i did  stopped me spending loads on new headphones.
> 
> Thanks Sceptic for the info think I'll install it when it comes  have time.
> 
> How you running the amp then sotto?  I must try and plug these into my record player some day but hardly ever use it now,  I love searching youtube for music  and have loads of mp3s , sounds really nice with my hd600s.


 

 The T1's are actually pretty comfortable. I was coming from a Grado so pretty much anything would've been an improvement in comfort.
  
 I pretty much only listen to music through my laptop, so I definitely need to buy myself a decent DAC. The thing is that we get ripped off so badly in the UK when it comes to this stuff. I'm interested in a Schiit Bifrost, but it costs £519 here, compared to $519 in the USA.


----------



## lost&confused

Thats great info Sir Doc thanks for taking the time.


----------



## lost&confused

yeah its bad with expense gear from the usa with duty,  I imported the Schiit Vali amp and payed about £30 duty. You can buy online with schitt USA website. 
  
 Them usb dacs are meant to be good , also Bottlehead I heard are making a dac  released soon i think.


----------



## roguegeek

matttcg said:


> I was really fishing to know what you thought of the hd800 with the crack.


 
 Gotcha. I think it's ok. I think a lot of people would be very happy with it as it takes the HD 800 and both darkens and warms it up a bit. Sound very nice with the HD 700 as well. People looking for that warmer tone would be happy, but it does take a bit of resolution away from the HD 800.


----------



## skeptic

Thanks for the great explanation Doc! This one definitely gets a bookmark for future reference.


----------



## olegausany

lost&confused said:


> Lazy!    I think its 120v sotto  but dont quote me on that ...someone will come along and comfirm it.
> 
> Whats your crack had done to it then? speedball  upgrade ? You in the UK then ?  I was going to buy a pre built one from another member but decided to go for it!
> 
> ...



It all depends on ones hearing. I also had Crack with Speedball (bought one from the member who sold it as soon he tested that build works properly) and tried different tubes and while difference sometimes very little and sometimes more noticeable I still heard enough to say that I prefer Sylvania 5814A over GE 5814A when paired with 5998 and but I prefer either 5814As over RCA Clear Top. On the other side I bought famous GEC 6AS7 brown base from another member who spent an evening comparing it with 5998 and heard no difference while for me and many others difference is very noticeable and is considered the best


----------



## DefQon

>


 
  
  
 I would cut off the protruding leads from the solder pad from the resistors and the fet on the S/B.


----------



## olegausany

lost&confused said:


> yeah its bad with expense gear from the usa with duty,  I imported the Schiit Vali amp and payed about £30 duty. You can buy online with schitt USA website.
> 
> Them usb dacs are meant to be good , also Bottlehead I heard are making a dac  released soon i think.



If funds permit get yourself a UK Dac Arcam irDac which is ever better than Bifrost Uber


----------



## skeptic

I've tempted by the irDac as well. The laser in my arcam dvd player has started to go, and I like arcam's general sound signature and Wolfson implementation a lot. Reviews are sadly scarce, but Whathifi seems to have heaps of praise for the irDac (more so than for arcam's flagship actually). 

Still holding out faith that Mr. Swenson works out the final minor kinks and green lights the bh dac soon though. Per his most recent update, it sounds like a little noise from hotswapping spdif cables, is only real remaining issue.


----------



## olegausany

I also was tempted by irDac and seeing to little reviews but seeing that Whathifi said it Dac of a year and knowing that I can easily send it back to Amazon I finally pulled the trigger. When I got and connected it and started listening I noticed that music sounds differently for me than with any other dac I had. Unfortunately I can't write review like many well known members here but I feel that it most neutral dac I had and I had blackest backgrounds if I understand this right and that micro details of bass region have best clarity I have heard so far when trying it with the moded SEX. I don't have it anymore being tempted to try X-Sabre so I sold it to another local member who now enjoying it with WA7 he bought several weeks before that


----------



## olegausany

olegausany said:


> I also was tempted by irDac and seeing to little reviews but seeing that Whathifi said it Dac of a year and knowing that I can easily send it back to Amazon I finally pulled the trigger. When I got and connected it and started listening I noticed that music sounds differently for me than with any other dac I had. Unfortunately I can't write review like many well known members here but I feel that it most neutral dac I had and I had blackest backgrounds if I understand this right and that micro details of bass region have best clarity I have heard so far when trying it with the moded SEX. I don't have it anymore being tempted to try X-Sabre so I sold it to another local member who now enjoying it with WA7 he bought several weeks before that I was using USB only/quote]


----------



## Doc B.

o





sonido said:


> Alas we come full circle to solid state where components should not impart its own sound.




Luckily for you guys you can build the kit either way and make it as tubby, I mean tubey as you like.


----------



## JamieMcC

Crack Noir!
  
 I had a real hard time finding black smoked tubes to complete the look I was after, I had a Tung-sol 12au7 black glass but finding a smoked driver tube was a nightmare. After a long time spent hunting for one I went with a uber rare and rather special RCA 6080 PIBs and a matching RCA 12au7 PIBs the combination though a little dark sounds pretty good!


----------



## lost&confused

Wow Jamie that looks really different from all the others I've seen great job!  Your amp would look nice on my desk  the carbon wrapped on the wood base looks good. Cant remeber seeing yours like that before..... You have spent alot of time on this amp looks amazing mate.
  
 I've only sanded and gave mine a clear coat of clear satin! ( a water based 
  
 Couldn't you just spray the normal tubes with some high temp spray? lol suppose you would of done that already.
  
 Great job


----------



## Aeolus Kratos

Hi Jamie,
I don't know for sure but your GEC 6AS7G looks pretty strange. It seems to be different from other GECs I've seen and owned ( yours is somehow a bit taller and thinner )


----------



## JamieMcC

aeolus kratos said:


> Hi Jamie,
> I don't know for sure but your GEC 6AS7G looks pretty strange. It seems to be different from other GECs I've seen and owned ( yours is somehow a bit taller and thinner )


 

 Hi Aeolus, most probably its the angle of the camera or lighting, I need to practice my photography skills a bit.  Just checked and it is exactly the same glass shape and plate structure as my other ones.


----------



## Jason8777

Hi Guys!
  
 Can any of you tell me if I could use these tubes with BH Crack w/ Speedball? I'm asking because the right speaker is dead when I plugged in the tube, both of them.  Bought these off eBay and seller stated they're NOS. Thanks in advance.


----------



## Aeolus Kratos

jamiemcc said:


> Hi Aeolus, most probably its the angle of the camera or lighting, I need to practice my photography skills a bit.  Just checked and it is exactly the same glass shape and plate structure as my other ones.



 


Wow Jamie, such a 'tiny' GEC collection you have  
By the way, how would you compare the straight base version and the round base version of the GEC? I've never heard any GEC round base version so I'm not sure if there is any difference in terms of sound quality between them.

Thanks.



jason8777 said:


> Hi Guys!
> 
> 
> 
> ...



 

Jason,

These tubes are Mullard CV4003 and they should work just fine with the Crack.


----------



## Jason8777

Thanks Aeolus Kratos,
 Well, I guess both of them are bad then.  Is there anything I can do? Bake them in oven like someone suggested?  Do you know? Hate to throw them in the trash since seller won't accept return


----------



## JamieMcC

jason8777 said:


> Thanks Aeolus Kratos,
> Well, I guess both of them are bad then.  Is there anything I can do? Bake them in oven like someone suggested?  Do you know? Hate to throw them in the trash since seller won't accept return


 

 Ask for a refund say unless one is forth coming you are going to contact ebay/paypal disputes and negative feedback will be left. If the seller is genuine there will not be a problem. If you paid via paypal you should have buyer protection and a good chance of getting some money back.


----------



## JamieMcC

> Originally Posted by *Aeolus Kratos* /img/forum/go_quote.gif
> 
> Wow Jamie, such a 'tiny' GEC collection you have
> 
> ...


 
  
 Aeolus, in my own set up I think the curved bases are a touch more refined but its not something you would notice across the board and could just as well be some sort of cognitive biasing taking place. I find its only really perceivable with simple music like say Eva Cassidy, to me it sounds like there is a touch more delicacy and vulnerability to the vocals I wouldn't notice the differences if say I was typing on the pc or working while listening, but sat back undistracted with eyes closed it sound very good indeed but perhaps I am just hearing what I want to hear. I've been burning in some new capacitors and for the last week my Cracks not been up to doing any critical listening with.
  
 As for my collection, lets just say I have been very lucky with my ebay purchases, just need a MOV branded one to make a full set now.


----------



## Doc B.

jason8777 said:


> Hi Guys!
> 
> Can any of you tell me if I could use these tubes with BH Crack w/ Speedball? I'm asking because the right speaker is dead when I plugged in the tube, both of them.  Bought these off eBay and seller stated they're NOS. Thanks in advance.


 
 If both tubes behave the same way I wonder if something came lose on the socket. Did you plug another tube in to check if it still worked OK on both channels? Either of those should sound very good.


----------



## Jason8777

doc b. said:


> If both tubes behave the same way I wonder if something came lose on the socket. Did you plug another tube in to check if it still worked OK on both channels? Either of those should sound very good.


 
 Thanks Doc B.!
 I have another CV4003 ( No Mullard printed on tube) I bought from the same seller and it works fine.  One thing I noticed when I plugged in the two defective tubes, i see a really bright light glowing on the bottom of the tube and it gone after 5 minutes or so on both tubes. Also, the amp hummed really loud when the light is glowing.  Not sure what is going on.


----------



## Jason8777

jamiemcc said:


> Ask for a refund say unless one is forth coming you are going to contact ebay/paypal disputes and negative feedback will be left. If the seller is genuine there will not be a problem. If you paid via paypal you should have buyer protection and a good chance of getting some money back.


 
 Thanks for the advice, I contact seller and he agreed to give me partial refund to close the case.  He said the problem could be "radio valve"  Not sure what that means  but i'm glad to get some money back.


----------



## Doc B.

jason8777 said:


> Thanks Doc B.!
> I have another CV4003 ( No Mullard printed on tube) I bought from the same seller and it works fine.  One thing I noticed when I plugged in the two defective tubes, i see a really bright light glowing on the bottom of the tube and it gone after 5 minutes or so on both tubes. Also, the amp hummed really loud when the light is glowing.  Not sure what is going on.


 
 Ah, well that sounds like an internal short. Too bad.


----------



## spacequeen7

*


----------



## Aeolus Kratos

jamiemcc said:


> Aeolus, in my own set up I think the curved bases are a touch more refined but its not something you would notice across the board and could just as well be some sort of cognitive biasing taking place. I find its only really perceivable with simple music like say Eva Cassidy, to me it sounds like there is a touch more delicacy and vulnerability to the vocals I wouldn't notice the differences if say I was typing on the pc or working while listening, but sat back undistracted with eyes closed it sound very good indeed but perhaps I am just hearing what I want to hear. I've been burning in some new capacitors and for the last week my Cracks not been up to doing any critical listening with.
> 
> As for my collection, lets just say I have been very lucky with my ebay purchases, just need a MOV branded one to make a full set now.



 


Thanks Jamie! I just owned a matched pair of the GEC straight base version and I'm too curious to try a curved one someday. Eva Cassidy is also my favorite singer, along with Corrinne May. Whenever you feel bored with keeping all the same brown base tubes and are willing to let one of your curved base one go, just shoot me a pm 

Thanks for your wonderful comparison. And good luck with your MOV branded finding.

Cheers,
Kratos.


----------



## grrraymond

A question that's been asked a million times but what DACs would people recommend in a Crack > HD650 chain? I'm thinking around the $300 mark but I'd ideally want a step up from the E7 to see what potential a DAC upgrade has. If I'm going to have to go to £500, I'll make room. The E7 has started with some strange flickering/power issue, probably the battery is on its way out, so I'm looking to replace it within the next couple of months, max. Schiit stuff is pretty hard to come by in the UK and would end up costing a fair bit more than for my transatlantic chums, so that's the Bifrost on the back burner. I've no idea where else to go, though.


----------



## olegausany

grrraymond said:


> A question that's been asked a million times but what DACs would people recommend in a Crack > HD650 chain? I'm thinking around the $300 mark but I'd ideally want a step up from the E7 to see what potential a DAC upgrade has. If I'm going to have to go to £500, I'll make room. The E7 has started with some strange flickering/power issue, probably the battery is on its way out, so I'm looking to replace it within the next couple of months, max. Schiit stuff is pretty hard to come by in the UK and would end up costing a fair bit more than for my transatlantic chums, so that's the Bifrost on the back burner. I've no idea where else to go, though.



Get yourself Cambridge Audio DacMagic Plus or, if funds permit, Arcam irDac. Those are UK dacs


----------



## JamieMcC

grrraymond said:


> A question that's been asked a million times but what DACs would people recommend in a Crack > HD650 chain? I'm thinking around the $300 mark but I'd ideally want a step up from the E7 to see what potential a DAC upgrade has. If I'm going to have to go to £500, I'll make room. The E7 has started with some strange flickering/power issue, probably the battery is on its way out, so I'm looking to replace it within the next couple of months, max. Schiit stuff is pretty hard to come by in the UK and would end up costing a fair bit more than for my transatlantic chums, so that's the Bifrost on the back burner. I've no idea where else to go, though.


 
  
 I'm thinking about picking up another Marantz na7004 network player for a second system it can be used as a stand alone dac (that's how mine is used withCrack) I have been impressed with the one I have. Originally they were around £700 and can be picked up now for around £200ish If you read through the reviews the dac section is reportedly out the same as in the reference Pearl model which cost £2500 when new and had some great reviews.
  
 I cant help but think a good option with a limited budget might be a used newish cd-player that has a digital input so the players dac can be used. I cant help but feel dac prices have run away with them selves there are plenty of great sounding cdplayers about something with SACD capability could be fun with cans.


----------



## spacequeen7

13D4s are the real deal ,this are earlier then 13D5 but look identical
  interesting tubes since micas are "see-through" ,the samples I received are very quite -low micro-phonic just like Tesla 802S
 13D5 sounds really good ..solid soundstage ,airy and sweet mids,clear top 
 http://www.ebay.com/itm/160808127350?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649


----------



## FlySweep

grrraymond said:


> A question that's been asked a million times but what DACs would people recommend in a Crack > HD650 chain? I'm thinking around the $300 mark but I'd ideally want a step up from the E7 to see what potential a DAC upgrade has. If I'm going to have to go to £500, I'll make room. The E7 has started with some strange flickering/power issue, probably the battery is on its way out, so I'm looking to replace it within the next couple of months, max. Schiit stuff is pretty hard to come by in the UK and would end up costing a fair bit more than for my transatlantic chums, so that's the Bifrost on the back burner. I've no idea where else to go, though.


 


olegausany said:


> Get yourself Cambridge Audio DacMagic Plus or, if funds permit, Arcam irDac. Those are UK dacs


 
  
 I'll add the Beresford Bushmaster MKII to the list.  Stanley Beresford is UK based.. I've had the BM MKII for the better part of three months.. it's terrific.. and can be used with a portable battery (which is said to improve the performance even more).  Also, it comes with a very impressive headphone amp section.. I found it pairs beautifully with the HD650, actually... believe it or not, it's got a similar 'feel' to the Crack, actually.


----------



## Klots

spacequeen7 said:


> 13D4s are the real deal ,this are earlier then 13D5 but look identical
> interesting tubes since micas are "see-through" ,the samples I received are very quite -low micro-phonic just like Tesla 802S
> 13D5 sounds really good ..solid soundstage ,airy and sweet mids,clear top
> http://www.ebay.com/itm/160808127350?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
> ...


----------



## roguegeek

Just installed the Speedball because... why not? Installation was only slightly harder than the standard Crack due to the limited room you have, but it was still relatively easy. What didn't work was the bottom mounting stand on the main motherboard. Where as the top one actually had a longer screw to screw into, the bottom one was flushed with the bolt. Needed to find another screw. Checked the original instructions to make sure I installed it properly to begin with and it seems like I did. Looks like a misstep somewhere.
  
 As for the sound, I haven't tried it enough yet for any initial impressions.


----------



## MoatsArt

Moving back to Crack...
  
 Can someone in Australia or NZ please let me know if they have an unbuilt Crack + SB kit for sale?  Will pay about $300.00 shipping.


----------



## Aeolus Kratos

moatsart said:


> Moving back to Crack...
> 
> 
> 
> ...



 


Welcome back, Nathan. I've truly been enjoying your wonderful GEC Brown base


----------



## MoatsArt

You don't want to sell it back to me :wink_face:

Seriously, I am after a nice power tube:

Tung 7236
Tung Sol/Chatham 5998
GEC 6AS7G

Single or pair is fine and happy with NOS or used.

Thanks!


----------



## grrraymond

Thanks for the DAC recommendations, chaps. I'll keep an eye out on eBay.


----------



## Feynman

Are your Bottlehead Crack completely silent? That is no kind of background noise at all? Because I have been struggling with a slight background hum ever since I built the amp back in 2011. This week I went over the solder joints and reheated the ones that looked a bit iffy and the background noise was lowered but if I concentrate I can still here it when there is no music playing.   
 So there is a very low background noise.


----------



## JamieMcC

feynman said:


> Are your Bottlehead Crack completely silent? That is no kind of background noise at all? Because I have been struggling with a slight background hum ever since I built the amp back in 2011. This week I went over the solder joints and reheated the ones that looked a bit iffy and the background noise was lowered but if I concentrate I can still here it when there is no music playing.
> So there is a very low background noise.


 

 I can say with confidence mine is completely silent with the HD 650 and Beyer T1. All the noises I have chased down so far have been from external influences.
  
 Post a pick of your Cracks wiring here or on the bottlehead forum (most probably better) it could be something as easy as slightly bending a cable which is picking up some interference into a better position.


----------



## Feynman

jamiemcc said:


> I can say with confidence mine is completely silent with the HD 650 and Beyer T1. All the noises I have chased down so far have been from external influences.
> 
> Post a pick of your Cracks wiring here or on the bottlehead forum (most probably better) it could be something as easy as slightly bending a cable which is picking up some interference into a better position.


 
 Okay! I better figure out what is wrong because I am planning to buy a set of HD800 and I don't want to plug them into something which is not working 100%. Right now I'm using HD650's! 
  
 Thanks, I've attached a picture below.


----------



## MoatsArt

Have you tried different tubes?


----------



## JamieMcC

Little story, I woke up this morning and had a bit of a panic. My Cracks by the side of the bed and I left it running all night for the first time (burning in some caps). The alarm on my phone woke me and I reached over to press a button which will snooze it. Then suddenly as I was coming round noticed a horrible low level and buzzing crackling sound from the Crack I'm now wide awake and quickly switched off the Crack,  now I am confused as the sound has not stopped a moments bewilderment then its relief to realise the noise is coming from my phone which is right next to the Crack. Unknowingly when going for the snooze I turned on the radio feature it has which wasn't tuned into a station.


----------



## Feynman

moatsart said:


> Have you tried different tubes?


 
 Yepp! Thing is that the tubes that came with the Crack originally are/were broken so using the introduced some horrible hum and crackling noises in the left channel. Bought two other tubes which work good except for the slight background hum.


----------



## MoatsArt

:bigsmile_face:

You crack me up Jamie


----------



## JamieMcC

feynman said:


> Okay! I better figure out what is wrong because I am planning to buy a set of HD800 and I don't want to plug them into something which is not working 100%. Right now I'm using HD650's!
> 
> Thanks, I've attached a picture below.


 
  
 The only thing that stands out to me with my limited knowledge is the braiding of the rca input wires could be a bit tighter and I have seen some builds use shielded wiring. 
  
 Have you tried the Crack with a different source like a cd player or phono to see the noise is still present?


----------



## uelover

My Crack + Speedball kit was shipped with 2 missing resistors. Been trying to get Bottlehead ship me those 2 missing resistors. Not sure how long it will take for them to ship out the 2 resistors to me, not to mention the additional wait due to shipping time.
  
 Communication with them hasn't been good.


----------



## MattTCG

Not to bash anyone but this seems to be happening too often IMO. If you going to sell a build it yourself kit, then you're should make darn sure that you include all the parts. Nothing would be more frustrating than missing one piece to complete your amp, that you've waited 4-6 weeks for, and not having everything in the box to finish. 
  
 I'm seeing this issue come up often lately and in fairness it needs to be addressed.


----------



## bigfatpaulie

I don't know what kind of QC they do at BH so I can't speak to that.  That said, there are a lot of small parts and I would suspect that sometimes the missing parts actually were packed but were lost upon unpacking.  I'm not saying that is what happened in this case, but I imagine it happens more often than one might expect.
  
 Plus, the internet is a great place to vent so we probably hear about EVERY missing part, but we don't hear about every perfect order that makes it.  I have a feeling the problem seems bigger than it actually is from our perspective.
  
 That said, it does happen - My kit was missing the BH badge.  They quickly shipped me one, but they did incur the extra shipping costs just like they will in the case of the resistors above.  That gets expensive quick and it would be in BH's favor to be more accurate (plus it is disappointing as you have pointed out).


----------



## JamieMcC

Quote:


uelover said:


> My Crack + Speedball kit was shipped with 2 missing resistors. Been trying to get Bottlehead ship me those 2 missing resistors. Not sure how long it will take for them to ship out the 2 resistors to me, not to mention the additional wait due to shipping time.
> 
> Communication with them hasn't been good.


 
  
 I think I remember seeing a post about Queen Bee (the lady who deals with emails and sending spares) being away for a few days this week, A quick pm to doc on headfi or on the bottlehead forum I am sure will see them posted to you quickly.
  
 --------------------------------------------------------------------
  
 Matt yes it can be frustrating on the flip side though if you fry parts of your Crack when building, Bottlehead are quick to send out free replacements. A lot of the resistors, caps,led's etc they hold in stock so its only a couple of days at most normally from what I can gather. It looks like the main reason for the long shipping times is to due processing batches of top plates and bases to keep control of costs. It would be very expensive to just do a couple of tops and bases at a time.


----------



## JamieMcC

bigfatpaulie said:


> I don't know what kind of QC they do at BH so I can't speak to that.  That said, there are a lot of small parts and I would suspect that sometimes the missing parts actually were packed but were lost upon unpacking.  I'm not saying that is what happened in this case, but I imagine it happens more often than one might expect.
> 
> Plus, the internet is a great place to vent so we probably hear about EVERY missing part, but we don't hear about every perfect order that makes it.  I have a feeling the problem seems bigger than it actually is from our perspective.
> 
> That said, it does happen - My kit was missing the BH badge.  They quickly shipped me one, but they did incur the extra shipping costs just like they will in the case of the resistors above.  That gets expensive quick and it would be in BH's favor to be more accurate (plus it is disappointing as you have pointed out).


 
  
 Err this happened to me with my speed ball kit, luckily I found the parts stuck to some of that sticky backed bubble wrap!  So didn't need to order spares.


----------



## bigfatpaulie

jamiemcc said:


> Err this happened to me with my speed ball kit, luckily I found the parts stuck to some of that sticky backed bubble wrap!  So didn't need to order spares.


 
  
 There you go.  It can happen to the best of us!


----------



## Doc B.

I do apologize for the missing parts. I will personally check into the followup on getting the replacements to you. If I can know who you are it would be helpful, as we don't have any way to correlate a Head-Fi username with our customer database.
  
 It's nice to have people here who offer suggestions on how to better our business. We've only been doing this for about 20 years and I'm sure we still have a lot to learn.


----------



## Tequilasunriser

jamiemcc said:


> The only thing that stands out to me with my limited knowledge is the braiding of the rca input wires could be a bit tighter and I have seen some builds use shielded wiring.
> 
> Have you tried the Crack with a different source like a cd player or phono to see the noise is still present?


 
 That was going to be my suggestion too, wrapping some sort of shielding around the RCA cables or redoing it with shielded cables. I seem to remember that being the most useful solution to resolving Crack hum over the years.


----------



## Feynman

tequilasunriser said:


> That was going to be my suggestion too, wrapping some sort of shielding around the RCA cables or redoing it with shielded cables. I seem to remember that being the most useful solution to resolving Crack hum over the years.


 
 What kind of shielding would it be possible to put there just to try it out without the need for recabling with new shielded cables? I would be so happy to be able to completely remove the hum!


----------



## Mahdi8

A copper shielding tape would do the job. But replacing the cable would be faster I think.


----------



## Doc B.

Before you put too much time into that verify whether the hum goes up and down as you turn the volume control. If it changes then it is possible that hum is being picked up somewhere ahead of the volume pot like the input wiring, or your interconnects or your source component. If the hum stays the same regardless of the volume setting don't waste too much effort on that part of the amp as that means the hum is coming in after the volume pot, like maybe a tube that has a little heater-cathode leakage or there is some interference in the room like maybe a power transformer on another piece of gear that is close to the amp.


----------



## roguegeek

The good news with a lot of the parts are that they the majority of them can be picked up somewhere or substituted for something else. I was missing a part from both my Crack and Speedball, but was able to source them fairly quick locally with help from the people on the forums.


----------



## spacequeen7

doc b. said:


> Before you put too much time into that verify whether the hum goes up and down as you turn the volume control. If it changes then it is possible that hum is being picked up somewhere ahead of the volume pot like the input wiring, or your interconnects or your source component. If the hum stays the same regardless of the volume setting don't waste too much effort on that part of the amp as that means the hum is coming in after the volume pot, like maybe a tube that has a little heater-cathode leakage or there is some interference in the room like maybe a power transformer on another piece of gear that is close to the amp.


 
 I just rechecked all that could cause the noise ...wish I payed more attention earlier..I had 1250W Seasonic PSU (for benching) connected to the power strip  just siting 7" behind the Crack ..I feel so dumb 
	

	
	
		
		

		
			





 (tapping on the Crack or tube and it's dead silent !!!!!!!)


----------



## olegausany

spacequeen7 said:


> doc b. said:
> 
> 
> > Before you put too much time into that verify whether the hum goes up and down as you turn the volume control. If it changes then it is possible that hum is being picked up somewhere ahead of the volume pot like the input wiring, or your interconnects or your source component. If the hum stays the same regardless of the volume setting don't waste too much effort on that part of the amp as that means the hum is coming in after the volume pot, like maybe a tube that has a little heater-cathode leakage or there is some interference in the room like maybe a power transformer on another piece of gear that is close to the amp.
> ...



A $10 power strip and then complaining? Get yourself a Furman one costing over $100 on Amazon and enjoy your music


----------



## mcandmar

spacequeen7 said:


> I just rechecked all that could cause the noise ...wish I payed more attention earlier..I had 1250W Seasonic PSU (for benching) connected to the power strip  just siting 7" behind the Crack ..I feel so dumb
> 
> 
> 
> ...


 
  
 That just goes to show, even with a very high quality ATX power supply it should still be kept as far away from audio equipment as possible.  I got caught out recently chasing a bzzzzzt noise only to find it was the energy saving light bulb i put into my desk lamp.  ...same lamp i was using to illuminating the wiring i was rerouting to cure the noise


----------



## evertzzz

excuse me Doc B., may I ask one thing? about the Crack OTL Headphone Amplifier Kit voltage input. If I order it with 240VAC power transformer, can it still be used in a place with 100sVAC?


----------



## Loquah

evertzzz said:


> excuse me Doc B., may I ask one thing? about the Crack OTL Headphone Amplifier Kit voltage input. If I order it with 240VAC power transformer, can it still be used in a place with 100sVAC?


 
  
 I can answer that I think (but I'm not not related to Bottlehead in any way so this doesn't represent a response from the manufacturer):
  
 The transformers are fixed voltage (i.e. not a smart system that adapts based on the power source you connect it to). In order to use the 240V transformer in a 100sV country you would need a step down transformer of some sort.


----------



## spacequeen7

olegausany said:


> A $10 power strip and then complaining? Get yourself a Furman one costing over $100 on Amazon and enjoy your music


 
 it's actually 8 Outlet Surge Protector (don't remember the name) ..I just call it power strip ,sorry


----------



## Feynman

doc b. said:


> Before you put too much time into that verify whether the hum goes up and down as you turn the volume control. If it changes then it is possible that hum is being picked up somewhere ahead of the volume pot like the input wiring, or your interconnects or your source component. If the hum stays the same regardless of the volume setting don't waste too much effort on that part of the amp as that means the hum is coming in after the volume pot, like maybe a tube that has a little heater-cathode leakage or there is some interference in the room like maybe a power transformer on another piece of gear that is close to the amp.


 
 Hi! 
  
 I checked the volume nob, the background noise is the same regardless of position. Also tried plugging in the amp to another wall-jack and the noise was still the same. I don't even know what heater-cathode leakage is, and is it possible to check wheter my tubes suffer from that without buying new ones? 
  
 edit: Okay tested with two different of the small tube (is this the driver tube or whatever you call it?) and the background noise is slightly higher using one of them compared to the other but still present. Unfortunaly I don't have a spare of the big one to try with.


----------



## palmfish

spacequeen7 said:


> it's actually 8 Outlet Surge Protector (don't remember the name) ..I just call it power strip ,sorry


 
  
 I personally stick with Belkin and APC. They cost between $15-$35 depending on the unit, but to me its worth paying a bit more for a reputable name brand.


----------



## olegausany

palmfish said:


> spacequeen7 said:
> 
> 
> > it's actually 8 Outlet Surge Protector (don't remember the name) ..I just call it power strip ,sorry
> ...



That's why i recommend the Furman one which is designed for Audio/Video use


----------



## Doc B.

evertzzz said:


> excuse me Doc B., may I ask one thing? about the Crack OTL Headphone Amplifier Kit voltage input. If I order it with 240VAC power transformer, can it still be used in a place with 100sVAC?




As someone else mentioned, you would need to use a 100v to 240v stepup transformer to use a 240v Crack amp in a 100V country. Or should I say _the_ 100v country, is 100v used anywhere besides Japan? We don't provide universal transformers because they require additional primary winding taps and terminals that significantly increase the labor cost of the power transformer. Based upon the very small number of amps that we hear of moving between different AC mains voltages this seems to be the most cost effective approach to offer our customers. Those few users who do move a piece of gear seem happy with fairly inexpensive step up or step down transformers.


----------



## skeptic

feynman said:


> Hi!
> 
> I checked the volume nob, the background noise is the same regardless of position. Also tried plugging in the amp to another wall-jack and the noise was still the same. I don't even know what heater-cathode leakage is, and is it possible to check wheter my tubes suffer from that without buying new ones?
> 
> edit: Okay tested with two different of the small tube (is this the driver tube or whatever you call it?) and the background noise is slightly higher using one of them compared to the other but still present. Unfortunaly I don't have a spare of the big one to try with.




I've found noise to be a much more prevalent issue with my various power tubes. Without a doubt, the first thing to try is picking up some cheap mil spec 6080's off ebay. There are almost always some up with buy it now + shipping for less than $10.

I have a fancy power conditioner that I used to use with my crack. When I moved the crack to another room, I found it was still dead quiet with a cheapie surge bar. My guess is that this is only really an issue if you have particularly dirty power. 

As a last resort, you could try redoing the input wiring from the rca's to your pot. My braid is really tight, as depicted below. (An older pic, prior to my most recent cap upgrade) My understanding is that this can play a real role in limiting noise. Good luck!


----------



## palmfish

olegausany said:


> That's why i recommend the Furman one which is designed for Audio/Video use




So are Belkin and APC.


----------



## olegausany

palmfish said:


> olegausany said:
> 
> 
> > That's why i recommend the Furman one which is designed for Audio/Video use
> ...



Ok for computer but not HiFi audio


----------



## palmfish

Your Crack must be different than mine. Mine works no matter what socket I plug it into (as long as its 120V/60 Hz).


----------



## ben_r_

palmfish said:


> Your Crack must be different than mine. Mine works no matter what socket I plug it into (as long as its 120V/60 Hz).


 

 Ha ha same here.


----------



## Armaegis

A $100 will get you a surge protector that has some filtering. You'll spend quite a bit more for a "conditioner".


----------



## spacequeen7

is anyone here using NuForce Icon HDP with Crack ?...I have the upgrade itch and was wondering if this DAC is worth pairing with El Crack ,another one I'm interested in is JDS Labs - Standalone ODAC


----------



## Armaegis

I did have that combo once upon a time and thought it was quite good. Looking at your current gear though, I'd say save up for a bigger jump unless the functionality of the HDP appeals to you (like the separate headamp for low impedance headphones, preamp capabilities, digital inputs, etc).


----------



## olegausany

spacequeen7 said:


> is anyone here using NuForce Icon HDP with Crack ?...I have the upgrade itch and was wondering if this DAC is worth pairing with El Crack ,another one I'm interested in is JDS Labs - Standalone ODAC



Never tried the ones you mentioning but getting higher end Dac does make the difference. Arcam irDac and Matrix X-Sabre are the most noticeable among those i have tried


----------



## ben_r_

spacequeen7 said:


> is anyone here using NuForce Icon HDP with Crack ?...I have the upgrade itch and was wondering if this DAC is worth pairing with El Crack ,another one I'm interested in is JDS Labs - Standalone ODAC


 

 I used to use the HDP and the HRT Music Streamer II with the Crack. Both were very fine. I couldnt tell a difference.


----------



## spacequeen7

olegausany said:


> Never tried the ones you mentioning but getting higher end Dac does make the difference. Arcam irDac and Matrix X-Sabre are the most noticeable among those i have tried


 
 little to big and to salty ,if I was going to spend "G"note on a DAC it would probably be Burson Soloist tho ,Thanks


----------



## JamieMcC

I tried the Raspberry Pi with the hifi berry dac with the Crack looking for a streaming solution and it was terrible in comparison to my Marantz. But then it was a tenth of the price.


----------



## diaBoliQu3

Anyone ever compare Asgard 2 vs Crack/ +SB for Senn HD 600?


----------



## grrraymond

I finally painted my top plate. Taped it all off and just went for it. Got to be one of the ugliest Cracks I've seen. Hammered British Racing Green with a deep mahogany base. I was using a slightly too big brush as well so it's an absolute ****show. I'll get some pics up for you guys when it's dried. Worth a chuckle. Already picked out the repaint colour, a pale copper. If that doesn't look any better I'm just going to spray the whole bloody thing matte black, base and all.


----------



## spacequeen7

grrraymond said:


> I finally painted my top plate. Taped it all off and just went for it. Got to be one of the ugliest Cracks I've seen. Hammered British Racing Green with a deep mahogany base. *I was using a slightly too big brush* as well so it's an absolute ****show. I'll get some pics up for you guys when it's dried. Worth a chuckle. Already picked out the repaint colour, a pale copper. If that doesn't look any better I'm just going to spray the whole bloody thing matte black, base and all.


 
 try one of this (if you want to cover it -spraying won't work ,you need sponge brush /thick cover/tap out technique 
 https://www.google.com/search?q=sponge+brush&rlz=1C1ASUC_enUS564US564&espv=2&es_sm=122&tbm=isch&tbo=u&source=univ&sa=X&ei=yU5AU6_kBcbgsASh7oLwCg&ved=0CE8QsAQ&biw=1920&bih=965
  
 quick look at my motherboard covered with liquid tape /sponge brush 
 http://imageshack.com/a/img824/4084/qrbu.jpg


----------



## grrraymond

Thanks, bud. I'll get down to the hardware store tomorrow and sort my life out. Good news is that it still sounds like a dream so not a complete downer.


----------



## Sonido

grrraymond said:


> Thanks, bud. I'll get down to the hardware store tomorrow and sort my life out. Good news is that it still sounds like a dream so not a complete downer.


 

 But please still show us what it looks like in its current state.


----------



## ben_r_

spacequeen7 said:


> try one of this (if you want to cover it -spraying won't work ,you need sponge brush /thick cover/tap out technique
> https://www.google.com/search?q=sponge+brush&rlz=1C1ASUC_enUS564US564&espv=2&es_sm=122&tbm=isch&tbo=u&source=univ&sa=X&ei=yU5AU6_kBcbgsASh7oLwCg&ved=0CE8QsAQ&biw=1920&bih=965
> 
> quick look at my motherboard covered with liquid tape /sponge brush
> http://imageshack.com/a/img824/4084/qrbu.jpg



Ha wow, I had no idea people painted their motherboards.


----------



## JamieMcC

A neat trick which can give a perfect paint finish on a top plate prior to building if you don't want to spray would be to clean and prep your plate as normal set your top plate up perfectly flat and level but slightly raised off what ever surface its on with plenty of old news paper underneath Its best to use a two part two part polyurethane an epoxy paint.  Pour the mixed paint over the plate and with a little gentle tilting encouragement it will flow out nicely and look perfect use a small cooking blow torch to super heat the air over any bubbles so they pop (not aimed directly at the paint) a single fine brush bristle will also do. I used this method to apply the clear finish to my plate and it worked really well doing a colour would be no different. For the pour I set my plate up level on and old electric oil filled radiator which was used to heat up the plate and speed up cure.
  
 After a light compound and a polish


----------



## MattTCG

Looks great Jamie!! I would love to give that a go sometime...


----------



## DutchGFX

My crack, stained ebony with black paint. The stain was too light, the paint too dark, so I mixed them, then lacquered it. I like it. It matches my other gear well. It also matches my desk well, which is cut straight from the side of a tree


----------



## spacequeen7

jamiemcc said:


> A neat trick which can give a perfect paint finish on a top plate prior to building if you don't want to spray would be to clean and prep your plate as normal set your top plate up perfectly flat and level but slightly raised off what ever surface its on with plenty of old news paper underneath Its best to use a two part two part polyurethane an epoxy paint.  Pour the mixed paint over the plate and with a little gentle tilting encouragement it will flow out nicely and look perfect use a small cooking blow torch to super heat the air over any bubbles so they pop (not aimed directly at the paint) a single fine brush bristle will also do. I used this method to apply the clear finish to my plate and it worked really well doing a colour would be no different. For the pour I set my plate up level on and old electric oil filled radiator which was used to heat up the plate and speed up cure.
> 
> After a light compound and a polish


 
 I use "Dragon Skin" which is self-leveling ,they use this in special effects (fake wounds or masks) it's very temperature/moisture  resistant (this mobo have layer of about  1/8" )
 and can take -300c under LN2


----------



## grrraymond

spacequeen, you have saved me from despair. I got down to the shop this morning, got a sponge brush and a finer artist's brush and gave the whole thing a liberal coat. Due to the hammered paint texturing, which I quite like anyway, you can't tell that the first coat was an absolute hatchet job. I still don't quite know why I went with this bizarre colour scheme, it now looks like some WW2 detonator device but nevertheless, the finish is salvaged and the colour scheme has a certain daft charm. Photos to follow!


----------



## spacequeen7

pics or it didn't happen


----------



## JamieMcC

dutchgfx said:


> My crack, stained ebony with black paint. The stain was too light, the paint too dark, so I mixed them, then lacquered it. I like it. It matches my other gear well. It also matches my desk well, which is cut straight from the side of a tree


 
  
 Hi Dutch good to see you have your Crack up and running, how are you liking it paired with the MF M1? I have been tempted a couple of times now to try one as they come up quiet often used in the UK for reasonable money. I also am a bit envious of your desk I love how big chunky slabs of wood can make great looking furniture.
  
 Jamie


----------



## DutchGFX

jamiemcc said:


> Hi Dutch good to see you have your Crack up and running, how are you liking it paired with the MF M1? I have been tempted a couple of times now to try one as they come up quiet often used in the UK for reasonable money. I also am a bit envious of your desk I love how big chunky slabs of wood can make great looking furniture.
> 
> Jamie




I love the pair! I had an X-Sabre, but felt it was too warm. I think the MF is the best DAC for the money for sure.


----------



## grrraymond

As promised...


----------



## MattTCG

^^ Looking very nice grrray!! 
  
 Would someone sell me a TS 5998. Mines getting a little buzzy.


----------



## spacequeen7

^^ I think this is green ..


----------



## Feynman

skeptic said:


> I've found noise to be a much more prevalent issue with my various power tubes. Without a doubt, the first thing to try is picking up some cheap mil spec 6080's off ebay. There are almost always some up with buy it now + shipping for less than $10.
> 
> I have a fancy power conditioner that I used to use with my crack. When I moved the crack to another room, I found it was still dead quiet with a cheapie surge bar. My guess is that this is only really an issue if you have particularly dirty power.
> 
> As a last resort, you could try redoing the input wiring from the rca's to your pot. My braid is really tight, as depicted below. (An older pic, prior to my most recent cap upgrade) My understanding is that this can play a real role in limiting noise. Good luck!


 
 Thanks a lot! 
  
 Ordered two cheap 6080 from ebay to try with, also ordered some new shielded furutech for the interal RCA wiring and will redo the braid, supertight, like yours. 
  
 Cheers


----------



## pdrm360

Can someone please recommend a tube that works well with both of the HD650 and HD800? Thanks!


----------



## olegausany

pdrm360 said:


> Can someone please recommend a tube that works well with both of the HD650 and HD800? Thanks!



5998 should work perfectly with HD800


----------



## MattTCG

olegausany said:


> 5998 should work perfectly with HD800


 
  
 +1


----------



## palmfish

The stock tubes sound great with the HD 600/650/800. If they didn't, the Crack wouldn't come with them.
  
 Seriously, my friend and I parked our Cracks side by side and compared them with our HD 800's (we each own pair). His Crack has GEC Brown base and RCA clear top and mine has CBS Hytrons. The amps were too close to call.


----------



## syphen606

I found the 6AS7G/5998 to be more microphonic and pick up more noises. I'm back to using a 6080WB. Seems to pick up less noise. I should have probably got the speedball instead of a quick collection of tubes.


----------



## Loquah

syphen606 said:


> I found the 6AS7G/5998 to be more microphonic and pick up more noises. I'm back to using a 6080WB. Seems to pick up less noise. I should have probably got the speedball instead of a quick collection of tubes.


 
  
 It's never too late to add a Speedball!


----------



## MattTCG

^^ +1 
  
 First rule of head-fi. Don't choose which one, chose how many.


----------



## syphen606

loquah said:


> It's never too late to add a Speedball!


 
  
 Oh I know!
  
 Its on the list of things to get.


----------



## pdrm360

Thanks!
  
 Quote:


olegausany said:


> 5998 should work perfectly with HD800


 


palmfish said:


> The stock tubes sound great with the HD 600/650/800. If they didn't, the Crack wouldn't come with them.
> 
> Seriously, my friend and I parked our Cracks side by side and compared them with our HD 800's (we each own pair). His Crack has GEC Brown base and RCA clear top and mine has CBS Hytrons. The amps were too close to call.


 


syphen606 said:


> I found the 6AS7G/5998 to be more microphonic and pick up more noises. I'm back to using a 6080WB. Seems to pick up less noise. I should have probably got the speedball instead of a quick collection of tubes.


----------



## pdrm360

matttcg said:


> olegausany said:
> 
> 
> > 5998 should work perfectly with HD800
> ...


 
  
 The Cracks look damn good with the 5998.


----------



## diaBoliQu3

Aune T1 + SB Crack + HD 600 = Awesome night.
  
 BTW, is it only me that feels Crack doesn't really sound like a tube amp? Maybe due to my Sylvania 6080?


----------



## spacequeen7

diaboliqu3 said:


> Aune T1 + SB Crack + HD 600 = Awesome night.
> 
> BTW, is it only me that feels Crack doesn't really sound like a tube amp? Maybe due to my Sylvania 6080?


 
  
 I'm glad you like it ,my best combination is (ECC85/6AQ8/B719 ULTRON-Aune T1) +(5998 and E80CC Amperex)


----------



## Loquah

diaboliqu3 said:


> Aune T1 + SB Crack + HD 600 = Awesome night.
> 
> BTW, is it only me that feels Crack doesn't really sound like a tube amp? Maybe due to my Sylvania 6080?


 
  
 It's definitely not thick and lush, but still smooth like a tube amp. That's its magic I think - balancing smoothness with clarity and speed.


----------



## spacequeen7

I did little mod today and anchor E80CC for good ,resistor replacement (stock 273omh /new 470omh ) dropped the voltage from 
 T1 and T5 


> replacing the 237 R1 Try replacing the 237 R1 resistors with 470 Ohm resistors to see if the voltage bumps down between* 55 and 85V*.


 
 http://bottlehead.com/smf/index.php/topic,5989.0.html
  
 stock voltage was ;
 Terminal 1: 105V
 Terminal 5: 106V
 P.S. some reported getting around 130V with this tube 
  
 after resistor swap
  
 Terminal 1: 81V
 Terminal 5: 84V 
  
 ..here is the best part ..new resistors made it sound insane !!


----------



## MoatsArt

Is that insane in a good way, or insane in a MoatsArt way?


----------



## MoatsArt

Doing the same mod later to work with ECC32


----------



## spacequeen7

moatsart said:


> Is that insane in a good way, or insane in a MoatsArt way?


 
 lol ..sounds way better buddy 
	

	
	
		
		

		
			





..hope it stays this way 
 Good luck with ECC32..hope it works out for you ..I have some really nice 6SN7s and would be interested


----------



## JamieMcC

spacequeen7 said:


> I did little mod today and anchor E80CC for good ,resistor replacement (stock 273omh /new 470omh ) dropped the voltage from
> T1 and T5
> http://bottlehead.com/smf/index.php/topic,5989.0.html
> 
> ...


 

 Great been following this on the bh forum and will pick up a pair of resistors and give it a try


----------



## diaBoliQu3

Guys, will power source influence how Crack sound? At where I live now, electric source are generator and solar. These are my result:
  
 Generator> wall socket> extension socket> Crack = Left side definitely weaker than right side.
 Generator> wall socket> voltage regulator> extension socket> Crack = Awesome.
 Solar> extension socket> Crack = Awesome.
  
 Now I notice sometimes my left headphone kinda weaker, and got low hiss from the amp. The technician who assembled my Crack told me there shouldn't be any hiss at all or unbalanced sound. And the guy who testing this amp before me also confirm me that there's no hiss or unbalance sound.
  
 Now I wondering if the hissing come from my power source? Or some parts/ soldering damaged or loosen while the amp posted to me? Hopefully can try this amp from my friends house next month. Need to bring this heavy ass amp. Phew!


----------



## diaBoliQu3

spacequeen7 said:


> I'm glad you like it ,my best combination is (ECC85/6AQ8/B719 ULTRON-Aune T1) +(5998 and E80CC Amperex)


 
 Now I just wondering if it's worth it I get Modi or stick with my Aune T1. BTW, what music are listening too?


----------



## Loquah

diaboliqu3 said:


> Now I just wondering if it's worth it I get Modi or stick with my Aune T1. BTW, what music are listening too?


 
  
 I've heard both (but not compared) and would say the Aune T1 and Modi are of similar quality (although they may have different signatures). Better to wait and go for a larger step in your upgrade if you decide to do so.


----------



## diaBoliQu3

loquah said:


> I've heard both (but not compared) and would say the Aune T1 and Modi are of similar quality (although they may have different signatures). Better to wait and go for a larger step in your upgrade if you decide to do so.


 
 Larger means above $300? Or above of above $300?


----------



## Loquah

diaboliqu3 said:


> Larger means above $300? Or above of above $300?


 
  
 I'd say (based only on my experiences) that you'd need to jump to the $500-600 mark to find significant improvements. Something like the Matrix Mini-i Pro, for example, which costs $599.


----------



## Serenitty

So I got my kit last week, everything was there (so far, I haven't opened the speedball bag yet), and I've had a ball assembling this thing.
  
 So I decided to try things a little differently...
  

  

  

  
 I bought a sheet of 18"x6" 16 gauge copper to make my own top plate, I really wanted the power and signal inputs on the back and the volume and headphone jack on the front.  I thought polished copper would be an interesting look.  That and I threw in brass 80 mesh screen and a bronze washer to accent the vent.  I don't have the tools to put the cooling slots in so I cut a 1.5" hole, lined it with the mesh and covered it with a 1.25" ID, 2" OD bronze thrust washer.  I have some brass strips on the way to use as straps to "hold" the top down.  I thought an old fashioned metal look would be fun.  Of course I'm going to spend a lot of time polishing this thing, it takes fingerprints like you wouldn't believe.
  
 At any rate, assembly went well, about 4 hours of soldering, the resistance checks all went well.  SO I clenched up and plugged it in, no smoke or fire and the voltage checks were all good.  When I plugged it in though there was NO sound.  I traced though everything looking for something loose, then I got the instructions out and started looking them over.  When I tried watching the headphone jack push in and out I realized it was spring loaded and the side of the jack that the inputs go into is actually important.  SInce the jack isn't on the top plate I spun it around so I could access the holes to solder them, and I wired it backwards.  Everything checked normal with the headphone plug out, but as soon as you plugged it in, I lost signal.   Some swearing and about 10 minutes of desoldering and re-soldering and the amp worked beautifully.
  
 I'm very impressed with the kit and the instructions, everything was clear and easy, thankfully there was extra wire, as some of my wire runs were longer than called for in the instructions.
  
 Now I need to figure out what to do with my top plate and wood.  Build a second one?


----------



## spacequeen7

diaboliqu3 said:


> Now I just wondering if it's worth it I get Modi or stick with my Aune T1. BTW, what music are listening too?


 
  
  


loquah said:


> I'd say (based only on my experiences) that you'd need to jump to the $500-600 mark to find significant improvements. Something like the Matrix Mini-i Pro, for example, which costs $599.


 
 ^^ this is what I'm doing now ..was going to upgrade my DAC  recently and was about to pull the trigger on  NuForce Icon HDP or Bifrost uber but decided to wait for more noticeable upgrade ,the one Loquah mention is good example
 Modi/Aune T1 sounds pretty similar -advantage Aune T1 since you can roll different tubes for desire sound sig.,and use modi only if I want to use only two tubes-> Crack or DV
 music ;Jazz ,Dubstep ,Rock,heavy metal,electronic 
 I know you like "headbanging" flavor and enjoy the stock tube Aune come with since it's pretty good fit for what you listening to ,try Sylvania / RCA 6BK7B on Aune and TS 7236+Tesla 802S or 6SN7GT on Crack (I will be listing a bunch of tubes in few days in Classified section )


----------



## MoatsArt

serenitty said:


> So I got my kit last week, everything was there (so far, I haven't opened the speedball bag yet), and I've had a ball assembling this thing.
> 
> So I decided to try things a little differently...
> 
> ...




Beautiful build. Congrats!


----------



## olegausany

spacequeen7 said:


> diaboliqu3 said:
> 
> 
> > Now I just wondering if it's worth it I get Modi or stick with my Aune T1. BTW, what music are listening too?
> ...



Better save more and get Arcam irDac, for example, than buying Bifrost Uber instead


----------



## JamieMcC

serenitty said:


> So I got my kit last week, everything was there (so far, I haven't opened the speedball bag yet), and I've had a ball assembling this thing.
> 
> So I decided to try things a little differently...


 
 Wow what a neat idea and using the the washer and mesh works well I quiet like how it looks.


----------



## spacequeen7

olegausany said:


> Better save more and get Arcam irDac, for example, than buying Bifrost Uber instead


 
 I will definitely consider Arcam but I really like the footprint of Matrix Mini-i Pro
 Thank you


----------



## Loquah

moatsart said:


> Beautiful build. Congrats!


 
  
 +1 - stunning!


----------



## diaBoliQu3

Thanks sensei... Will funding a better DAC since gonna use it for my hifi too. Crack is good enough but I think with my current tube and DAC, I feels that she's underperform.


----------



## Loquah

diaboliqu3 said:


> Thanks sensei... Will funding a better DAC since gonna use it for my hifi too. Crack is good enough but I think with my current tube and DAC, I feels that she's underperform.


 
  
 You're using the Aune T1? If you are then there is definitely more performance you can squeeze out. It's incremental increases from here forward, but they're there to be had...


----------



## MoatsArt

Please let me know if you want tube/pot upgrades for Crack. Have just listed some options in tweaking sale thread (see my sig).

Back to our regular scheduled programming.....


----------



## grrraymond

I love that brassy build. Gorgeous.


----------



## syphen606

grrraymond said:


> I love that brassy build. Gorgeous.


 
  
 A mostly zinc-free, brassy build!  
  
  
 It does look pretty darn good though!


----------



## Serenitty

Yeah, I'd say the zinc and tin content are pretty low...  The copper seems like an unalloyed version, it is a little soft, the drill bits half cut material away and half pushed it through the holes, this resulted in a fair amount of filing to get the holes clear and smooth enough to use.  My jig saw cut the square holes out like cutting through wood.  I was able to cut the 1.5" hole for the vent with my cordless drill.  So pretty easy to work with, I taped the whole thing up with automotive painters tape (the green stuff) to protect the surface and to give me something to write on.  Thankfully we have a metal brake at work that I was able to use to make the bends. 
  
 I'm pretty happy with it, the wood work could have been better, I've thought about finding some exotic wood and making a second base to see how it looks.


----------



## MattTCG

You might try to find some spalted maple. It's the best looking wood for a show piece that I've seen.


----------



## Serenitty

matttcg said:


> You might try to find some spalted maple. It's the best looking wood for a show piece that I've seen.


 

 Looking at pictures of that online I agree that would be a nice choice.  Finding a suitable board might take some time, a quick search mostly showed small pieces for sale.


----------



## diaBoliQu3

loquah said:


> You're using the Aune T1? If you are then there is definitely more performance you can squeeze out. It's incremental increases from here forward, but they're there to be had...


 
 Ya, Aune T1. Do you mean squeeze my Aune T1 or squeeze budget for a better DAC?


----------



## Jason8777

cswift6 said:


> in love


 
 + 1 me too


----------



## skeptic

Beautiful job on your build Serenitty!  Even if you do have to polish it frequently, that copper looks amazing!  Any chance you'd be willing to post an "upskirt" shot of your amp so we can see how you mounted everything?


----------



## Serenitty

skeptic said:


> Beautiful job on your build Serenitty!  Even if you do have to polish it frequently, that copper looks amazing!  Any chance you'd be willing to post an "upskirt" shot of your amp so we can see how you mounted everything?


 

  
 Ask and ye shall receive...  This shot is before I fixed the inputs to the jack.  They're backwards here.


----------



## atraf

I am planning on buying the hd650 as far I can see the best amp for them is the crack, though the DYI kind of push me away towards Schiit Valhalla, I do know how to solder but that is it, I have no knowledge of voltages and such .. and I get the feeling soldering is not the hole dill, what do you think?
  
 Another thing does the crack come in a different frame color or the one I saw was modified and colored by its owner?


----------



## Serenitty

atraf said:


> I am planning on buying the hd650 as far I can see the best amp for them is the crack, though the DYI kind of push me away towards Schiit Valhalla, I do know how to solder but that is it, I have no knowledge of voltages and such .. and I get the feeling soldering is not the hole dill, what do you think?
> 
> Another thing does the crack come in a different frame color or the one I saw was modified and colored by its owner?




I had the hd650 with the Bifrost and Valhalla, it was certainly a nice combination. I'm now running T1's with the crack I just finished with a FIFO e17 as a Dac. I can't compare the sound, since I sold the 650/schiit combo a while ago. 

My soldering skills were limited and my build went very smoothly. Having a good iron helps a lot, and a decent multimeter. The instructions are fantastic, I was able to modify my build based on the pictures.


----------



## ridethespiral

Anyone bought the kit lately? If so how long did it take for them to ship it? I think I'm going to take the plunge when I get paid next week. 

Sent from my Nexus 5 using Tapatalk


----------



## MattTCG

4-6 weeks.


----------



## skeptic

serenitty said:


> Ask and ye shall receive...  This shot is before I fixed the inputs to the jack.  They're backwards here.


 
  
 Very nice clean build - thanks for sharing the internal photo!  Plenty of room to add in some film output caps too when you feel like further tweaks.


----------



## Serenitty

skeptic said:


> Very nice clean build - thanks for sharing the internal photo!  Plenty of room to add in some film output caps too when you feel like further tweaks.




I made it taller than stock to be ready for that, speedball next though. I want some time with the amp before I install the speedball.


----------



## Loquah

diaboliqu3 said:


> Ya, Aune T1. Do you mean squeeze my Aune T1 or squeeze budget for a better DAC?


 
  
 Sorry, I was really unclear. I meant you can still squeeze more performance from the Crack by buying a better DAC in future. I was amazed at how good the Crack sounded with my X-Sabre. I had thought that perhaps the Crack's performance would be a bottleneck to the much higher priced DAC, but it wasn't - there was a noticeable improvement from the Audio-gd NFB-5.2 to the Matrix X-Sabre using the Crack and beyer T1s


----------



## skeptic

serenitty said:


> I made it taller than stock to be ready for that, speedball next though. I want some time with the amp before I install the speedball.


 
  
 Sounds like a good plan to me!  One item to note given your anticipated upgrade path - you may want to plan to install fly leads and move your stock output caps out to the sides before putting in your speedball boards.  Accessing those terminals afterwards is much more of a hassle.  For now though, hope you find great enjoyment in your new amp!


----------



## ridethespiral

Bummer. Was hoping the four week wait was just to cover their butt. Oh well, thanks!

Gives me time to find a good deal on a better soldering iron though.

What kind of solder did you guys use? I have some that is 55% tin 40% lead and 5% silver with rosin core. Worked great for modding xbox's I assume it will suffice, though it is quite old.



matttcg said:


> 4-6 weeks.




Sent from my Nexus 5 using Tapatalk


----------



## Serenitty

ridethespiral said:


> Bummer. Was hoping the four week wait was just to cover their butt. Oh well, thanks!
> 
> Gives me time to find a good deal on a better soldering iron though.
> 
> ...




I used 63/37 solder, silver solder is not recommended in the manual, apparently it does not flow as well.


----------



## ridethespiral

By "flow well" do you mean its wetting ability? It worked awesomely for installing pin headers & wires on a PCB when I last used it, but I have no problem getting a new roll. Stuff is pretty cheap.
  
 One last quick question, is a 15w iron going to have enough power? Works good for PCB's but I'd imagine a 30w iron would work a lot better making the connections in the crack. I've used the 15w to also solder 1/4" neutrik connectors onto cable but it took quite a while to get the ground/shield soldered from what I remember.


----------



## Serenitty

ridethespiral said:


> By "flow well" do you mean its wetting ability? It worked awesomely for installing pin headers & wires on a PCB when I last used it, but I have no problem getting a new roll. Stuff is pretty cheap.
> 
> One last quick question, is a 15w iron going to have enough power? Works good for PCB's but I'd imagine a 30w iron would work a lot better making the connections in the crack. I've used the 15w to also solder 1/4" neutrik connectors onto cable but it took quite a while to get the ground/shield soldered from what I remember.




I used an Ayoue 9378 60 watt soldering station I got from Amazon. Overkill, I think, but very nice.


----------



## ridethespiral

Definitely overkill for the time being 
  
 Maybe perhaps once I get more into building DIY guitar/bass pedals I'll invest in a soldering station. I'll definitely get one that is more powerful though. That would be a piss off getting the kit and not being able to solder easily.


----------



## Sonido

Anything but lead-free (tin only) solder. That stuff doesn't melt.


----------



## ridethespiral

Here's a good read on another reason why lead-free solder is bad. I found it really interesting. It's about "tin whiskers"
  
 http://www.maximintegrated.com/app-notes/index.mvp/id/5250
  

  
  
 Thanks for the input all


----------



## atraf

what do you guys think of crack vs project ember ? which is better? I can't find very much reviews on it..


----------



## Zashoomin

atraf said:


> what do you guys think of crack vs project ember ? which is better? I can't find very much reviews on it..


 
 They are completely different amps so there isn't much you can compare.  It honestly depends on what you are going to be powering.


----------



## Doc B.

@ridethespiral, get at least a 40W iron. A 15W iron will only frustrate you. The terminals and components you deal with in these kits have much more mass and take a lot more energy to heat.


----------



## larcenasb

UPDATED 10/12/14
  
 Hello everyone,
  
 Just wanted to share my Crack build for those of you thinking about building or upgrading one... I myself was inspired by deltaunit (from the Bottlehead forum), HiGHFLYiN9 (from Head-Fi), and the design of the Decware CSP2 -- so my sincere thanks goes to all of them.
  

  
 Here is my humble set-up: M-Audio 2496 -> GlowPower Zilence ICs -> Bottlehead Crack -> AKG K612
  
I
  
*The sound*: First of all, I'm in love with the AKG house sound: that open clarity in the mids and the spaciousness overall are traits I will never compromise. So, I wanted a tube amp to help with the K601's and K612's shortcomings: the modest bass and lack of weight. The Crack with my tweaks listed below really has kicked down the door between my music and my emotions, to the point where I really don't feel a need to upgrade anymore. The AKGs themselves are a bit cold and thin, but with my upgraded Crack, the sound transforms to a weighty, smooth, powerful, life-injecting experience. When listening to ( ) by _Sigur Ros,_ the richness of tone and fluidity are hypnotic and seductive; the weight and air churn and tighten my insides so as to command me to take a deep breath. Without the amp, the sound is just sounds (incohesive and analytical) and doesn't feel like music is supposed to. My favorite piece is _Nirvana_'s Unplugged in New York performance. It's raw, haunting, emotional, sincere and beautiful. Even at low volumes, Kurt Cobain's voice reaches deep into my soul, clenching it with an ironclad fist; during 'All Apologies', his vocals tear through the air unrestrainedly like a wolf howling in silhouette before a full moon as the cello, bass guitar, and drums act as the clouds, wind and shadows to round out this heavy yet enlightening atmosphere around my head. Notice my sentimentality and over-the-top descriptions? _That's what it's all about_. Before this, I just didn't feel the music. Point is: I hope you find or have a set-up that let's you gush like this too


----------



## MoatsArt

The TS 7236 is my favourite power cap for the Crack. Clarity and tight, fast bass in spades. 

Brilliant work and great impressions for those looking to upgrade. 

If you like the 7236, you will love what Speedball does.


----------



## larcenasb

AH! I can't imagine the sound getting much better ...so I really am curious about the Speedball now. If and when I do get it, I'll be sure to update my post with my impressions. Thank you for the kind words. Take care and enjoy the music.


----------



## JamieMcC

larcenasb said:


> Hello everyone,
> 
> Just wanted to share my Crack build for those of you thinking about building or upgrading one... I myself was inspired by deltaunit (from the Bottlehead forum), HiGHFLYiN9 (from Head-Fi), and the design of the Decware CSP2 -- so my sincere thanks goes to all of them.
> 
> ...


 
  
 Congrats a nice build and I like the white top it gives it a nice clean n fresh look and can clearly see the heritage from your inspiration coming through.


----------



## atraf

zashoomin said:


> They are completely different amps so there isn't much you can compare.  It honestly depends on what you are going to be powering.


 
 HD650 I also have an IEM gr07BE but I guess I will have to pass on that since it won't work with low impedance HP's (42ohm)


----------



## larcenasb

Thanks JamieMcC,

I just looked through your gallery of recent Crack pics... That all black/carbon fiber look is sleeeeek, especially with those dark glass tubes. What kind of tubes are those? If it's not too much trouble, could you state your favorite 12AU7s for the Crack? Have you tried the Mullard square getter (date code: k61)?

Happy listening,

larcenasb


----------



## olegausany

Get Mullard E80CC you will never regret it


----------



## MoatsArt

Have a look in the cables, accessories for sale thread


----------



## JamieMcC

larcenasb said:


> Thanks JamieMcC,
> 
> I just looked through your gallery of recent Crack pics... That all black/carbon fiber look is sleeeeek, especially with those dark glass tubes. What kind of tubes are those? If it's not too much trouble, could you state your favorite 12AU7s for the Crack? Have you tried the Mullard square getter (date code: k61)?
> 
> ...


 
  
 Hi thanks for the kind comments details on the Crack Noir tubes here
  
 http://bottlehead.com/smf/index.php/topic,6010.0.html
  
 My build log
  
 http://bottlehead.com/smf/index.php?topic=5284.msg50967#msg50967
  
 My favourite 12au7's are the Mullards the standard ecc82 and the 4003 box-plates closely followed by the Tung-sol 12au7 black glass and the 1950's Tung sol 12au7 jtl. The E80cc is also a nice tube very much on par with the best of the 12au7/eec82 I have tried and a option if you have a speedball fitted.


----------



## JamieMcC

My postman dropped off a little brown package this morning inside a Tung-sol/Bendix 6080wb 
	

	
	
		
		

		
			





 I had been curious to try a graphite tube for a while now.


----------



## MattTCG

Looks great. How does it sound?


----------



## JamieMcC

matttcg said:


> Looks great. How does it sound?


 

 Based only on couple of hours so far to me its almost like a cross between a 5998 and the Mullard 6080wa. It has a big, bold & fast sound which is punchy and dynamic that's for sure.
  
 Its darker weightier and more tubey sounding than a 5998 while keeping some of its refinement but not quiet with the same levels of resolution and finesse as the 5998. There is more slam and punch to the bass!
  
 Sound stage reminds me of the Mullard its got that detached holographic surreal-ness to it with lots of air and separation. Its certainly stands out as being different to the tubes I have tried so far.


----------



## MattTCG

Seems like a winner/keeper to me.


----------



## FlySweep

I love how Bendix 6080 tubes w/ graphite plates look: very rugged and tough... they've got a nice weight to them, too (in hand and in sound).. they're a nice compliment to the more elegant-looking, ST-shaped 5998.  Terrific dynamics.. wonderful bass.. and a great sense of smoothness.  Not quite as transparent and spacious as the 5998.. but the Bendix 6080 I have (with slotted graphite plates) has a deeper stage that's quite addictive to listen to.


----------



## Nic Rhodes

The red bank tubes have always been fun, I just wish I had more than I do


----------



## Doc B.

Funny hearing about these, as my first kit build in the 90's was a long defunct amp kit from World HiFi that used a 6080. I happened across several of those graphite plate tubes at some estate sale or other, and tried them out in that very first kit amp. I think I still have a stash of them somewhere.


----------



## spacequeen7

Few weeks ago I was about  to paint the transformer and when trying to unscrew it (I had my headphones on and didn't here it cracking )
 I used my kung-fu grip and totally snapped the six lug terminal strip that's holding the transformer  ..I was getting  worry since it looked like I was going to wait weeks or longer to get the replacement ..I was blown away with the BH support ! ,the parts ("and then some")  came in yesterday and I'm really getting close to finishing my sweet El Crack ,Thank you Bottlehead ,especially Doc B. !
 P.S. love the badge
  

  
  
  
 Quote:


jamiemcc said:


> Based only on couple of hours so far to me its almost like a cross between a 5998 and the Mullard 6080wa. It has a big, bold & fast sound which is punchy and dynamic that's for sure.
> 
> Its darker weightier and more tubey sounding than a 5998 while keeping some of its refinement but not quiet with the same levels of resolution and finesse as the 5998. There is more slam and punch to the bass!
> 
> Sound stage reminds me of the Mullard its got that detached holographic surreal-ness to it with lots of air and separation. Its certainly stands out as being different to the tubes I have tried so far.


 
 I have been playing with my "red bank" for few weeks and found the answer ..,at first i couldn't figure out why this candle didn't sound right on Crack when I got it ,tried my DV336SE and loved it ,why ?...try to pair it with  6SN7 
	

	
	
		
		

		
			




  

  
 P.S. try Savant with this tube ...your might like it to much ,lol


----------



## Tequilasunriser

Do you have to make any internal modifications to the crack to use 6SN7 as the driver tube or does it only require a socket adaptor?


----------



## williaty

I finally got around to changing the volume control in my Crack; something which I had only meant to do for the last several years.. sigh. I went with a Valab 23-position 50k-ohm ladder stepper. Two thoughts:

1) This is easily the most craptastic switch I've ever touched.

2) I really should have done this a LONG time ago. I wasn't expecting much and at first it seemed like I was right. Then I realized how much it had changed the ability to separate things from each other (hear choral voices as individuals, etc). I can only assume it reduced either noise or distortion to achieve this as the tonal balance and range didn't change at all.


----------



## Feynman

A few pages ago I wrote about my crack which makes a background hum/noise. I re-braided the signal inputs with furutech copper cable really tight and the noise is still present. Is it possible that some of the tubes introduce a breezing sound? I have been using the same tubes for almost three years.
  
 By the way, installing a new volume attenuatior seems like a really nice thing to do. If I can manage to fix my noise that will be next on my list!


----------



## UmustBKidn

atraf said:


> what do you guys think of crack vs project ember ? which is better? I can't find very much reviews on it..


 
  
 All of those garage amps are hybrids, not all tube designs. They use a tube for the preamp but solid state for the output sections. They are all rip-off's of either the Bravo amps or a design posted on a DIY audio form some 4-5 years ago, with supposedly better parts. I've never heard them nor will I ever buy one, because they're way too expensive for what they are, in my opinion. For the money, a Bottlehead Crack is a clearly superior choice.


----------



## skeptic

tequilasunriser said:


> Do you have to make any internal modifications to the crack to use 6SN7 as the driver tube or does it only require a socket adaptor?


 
  
 6SN7's are nominally drop in equivalents, and some users have reported great success simply by using ebay adapters.  Others of us have had real trouble with plainly audible noise when using these adapters.  I've tried 2 different adapters (one user reported trying 4 different adapters without success), and both had pretty significant noise issues.  As discussed here and on the bh forums, the theory is that these issues could be resolved by using a wallwart to run dc to the 6sn7's heaters.  They are apparently more prone to noise than 12au7's when supplied with ac.  But I don't know anyone who has actually taken the time to try this mod and report back.  Hope that helps!


----------



## spacequeen7

skeptic said:


> 6SN7's are nominally drop in equivalents, and some users have reported great success simply by using ebay adapters.  Others of us have had real trouble with plainly audible noise when using these adapters.  I've tried 2 different adapters (one user reported trying 4 different adapters without success), and both had pretty significant noise issues.  As discussed here and on the bh forums, the theory is that these issues could be resolved by using a wallwart to run dc to the 6sn7's heaters.  They are apparently more prone to noise than 12au7's when supplied with ac.  But I don't know anyone who has actually taken the time to try this mod and report back.  Hope that helps!


 
 I don't think the adapter is the source of noise (I have 2 and both work very well ) ,6SN7s are known for microphonics ,hum,etc ,out of the bunch of 6SN7s I have, some have slight hum and some don't and they are dead silent ,if I would have to recommend one tube that would most likely work well it would be   VT231 - NOS TUNG SOL 6SN7 - 1940's - 6SN7GT TUNG SOL (black bottle),this were reported for the last few years to be very quite on a lot of different tube amps 
 EDIT; I have few that have very bad hum on DV336SE but not on Crack


----------



## skeptic

I do hear good things about VT231's but my comment above was simply repeating what bottlehead's engineers have noted several times on the bh forums.  Your red text misses the critical final clause - that 6sn7's are more sensitive with respect to the type of power delivered to their heaters.  The crack supplies AC when DC is the ideal for 6sn7's in particular.  
  
 Certain tubes may well be less prone to this, but Adam and I both tried many different tubes and the noise ranged from annoying to terrible.


----------



## atraf

umustbkidn said:


> All of those garage amps are hybrids, not all tube designs. They use a tube for the preamp but solid state for the output sections. They are all rip-off's of either the Bravo amps or a design posted on a DIY audio form some 4-5 years ago, with supposedly better parts. I've never heard them nor will I ever buy one, because they're way too expensive for what they are, in my opinion. For the money, a Bottlehead Crack is a clearly superior choice.


 
 Thank you for this information, I guess that leaves me with the choice between Valhalla and the BH, the Valhalla just seem like the safer way to go DYI wise :\ 
 I am looking for something that will really brings out the bass capabilities of the HD650.. I heard them with Naim DAC-V1 it was freaking amazing, only if I was richer 
  
 Since the Naim is a SS do you think it will be hard to find a Tube amp with same sound signature bass wise?


----------



## olegausany

I still have for sale matching pair of Kenrad 6SN7/VT231 made in 1944-45 according to eBay seller i bought them from plus adapter and while i had no noise issues i heard nothing special to write about 

Sent from my LG-V500 using Tapatalk


----------



## spacequeen7

atraf said:


> Thank you for this information, I guess that leaves me with the choice between Valhalla and the BH, the Valhalla just seem like the safer way to go DYI wise :\
> I am looking for something that will really brings out the bass capabilities of the HD650.. I heard them with Naim DAC-V1 it was freaking amazing, only if I was richer
> 
> Since the Naim is a SS do you think it will be hard to find a Tube amp with same sound signature bass wise?


 
 I'm using 5998 +E80CC Amperex PQ on Crack and Ultron ECC85 6AQ8 on Aune T1- the bass and soundstage is jaw dropping ,it lead me to swapping resistors on Crack so I can get closer to ideal 75v..I would say it's all in the tubes  
  
 Quote:


olegausany said:


> I still have for sale matching pair of Kenrad 6SN7/VT231 made in 1944-45 according to eBay seller i bought them from plus adapter and while i had no noise issues i heard nothing special to write about
> 
> Sent from my LG-V500 using Tapatalk



 same here ,unlike grey RCA ,black TS bottle 
 I prefer pairing  A1834/6AS7G with 6SN7 instead of 5998


----------



## olegausany

spacequeen7 said:


> atraf said:
> 
> 
> > Thank you for this information, I guess that leaves me with the choice between Valhalla and the BH, the Valhalla just seem like the safer way to go DYI wise :\
> ...



I have tried my 6SN7 with 5 different tubes , Chatham 5998, famous GEC 6AS7 brown base and Winged C 6H13C for example and non of them i was happy with


----------



## Mahdi8

Have anyone seen this tube before? I got it from ebay last night. looks quite rare


----------



## Loquah

Nice looking tube! What model number?


----------



## Mahdi8

It's advertised as Mullard 6as7g but can't fine any details of it


----------



## Loquah

It certainly looks right. I wonder if Mullard made it or if it's a re-badge.

How does it sound compared to your other 6AS7G?


----------



## MattTCG

mahdi8 said:


> Have anyone seen this tube before? I got it from ebay last night. looks quite rare


 
  
 Well, how does it sound?


----------



## GrindingThud

Looks like an RCA rebrand... Is there an octagon on the glass with 6AS7G in it somewhere? Nice looking box too!


----------



## Mahdi8

Haven't receive it yet Just bought it on ebay last night. should receive it in 2 days or so will update on how it sounds when I receive it


----------



## MoatsArt

A rebrand, no question. Made in USA. How much did you pay?


----------



## Mahdi8

$23 delivered so it's cheap


----------



## prtuc2

Hello Everyone,
  
 Looking for some assistant with my crack right now, appreciate any help.
  
 On page 19 of the manual, it said connected the black wire from terminal 4 to terminal 22L and right below it the instruction said connect terminal 4 to terminal 14U.  So, I left terminal 22L open is that a problem?
  
 Second problem is the resistance check, most of the terminal value matches up and others left me worry.  Terminals with * value I got *OL *from my multimeter and on terminal 13 instead of 270K ohms I got *OL, *so going to resolder that terminal.  But where it said RCA jacks: Center pin, I can't figure out where that is?
  
 Thanks for any inputs.


----------



## Loquah

prtuc2 said:


> Hello Everyone,
> 
> Looking for some assistant with my crack right now, appreciate any help.
> 
> ...


 
  
 Changing from 14U to 22L is completely fine and will leave 22L open. This should actually lower the noise floor.
  
 You should definitely be getting within about 10% for all resistance checks so definitely resolder as you suggest.
  
 The centre pin on the RCA is the stalk that sticks out the middle of the back of the RCA terminal. You will have a solder tab at the base of the RCA near the chassis plate and you'll have a hollow stalk sticking out of the middle of the RCA socket. I can send a pic if this doesn't make sense so let me know.
  
 Good luck finding the culprit!!


----------



## Loquah

Can anyone send me the PDF of the Crack manual? I'm helping another Head-Fier get ready for a customised build and need to know the various capacitor locations and sizes.


----------



## pdrm360

loquah said:


> Can anyone send me the PDF of the Crack manual? I'm helping another Head-Fier get ready for a customised build and need to know the various capacitor locations and sizes.


 
 PM sent


----------



## Doc B.

Thank you for taking care of Loquah!


----------



## prtuc2

Right now a new challenge has came up, on the manual it said:
  
*Clip the fuse into the fuse cover and insert the cover into the power entry module*
  
 Assuming the silver/white tube is the fuse? I can't fit it into the power entry module without damaging it.  Any picture or video instructions will be greatly appreciated.
  
 Thanks for any input.


----------



## Shaldome

prtuc2 said:


> Right now a new challenge has came up, on the manual it said:
> 
> *Clip the fuse into the fuse cover and insert the cover into the power entry module*
> 
> ...


 

 Are you trying to put the fuse directly into the socket? You have to "clip" the fuse to the the plastic piece you pulled out of the power module.
 After that you can put it back it with the fuse in place.


----------



## prtuc2

Yes, got that working and new problem arises DIY is always a fun being you learn from your mistakes.  Right channel of my headphone just start hearing crackling sound then the channel seems to be gone.  I re-test the headphone on my speaker amp it is still working, but need some inputs on the possible mishaps on my part.  I did noticed plugging the RCA cable into the white RCA jack was a hard to put in.
  
 Once again appreciate any inputs.


----------



## ffivaz

prtuc2 said:


> Yes, got that working and new problem arises DIY is always a fun being you learn from your mistakes.  Right channel of my headphone just start hearing crackling sound then the channel seems to be gone.  I re-test the headphone on my speaker amp it is still working, but need some inputs on the possible mishaps on my part.  I did noticed plugging the RCA cable into the white RCA jack was a hard to put in.
> 
> Once again appreciate any inputs.


 
  
 You would receive better inputs if you posted your problems on the Bottlehead forum. Back there, you would be asked if your resistance checks and voltage checks were fine. Were they ? If the noise is only in one channel, then you have a cold solder joint in the signal path of this channel, or sometimes (but it's a rare sometimes) a bad tube. You could try the chopstick test : the test for the hardcore diy guys. Take a wooden stick (wooden, nothing else) and try to poke different connections inside your crack to find the one that makes the most noise in your headphone. There, you will find your cold solder joint or bad component.
  
 Good luck!


----------



## Loquah

ffivaz said:


> You would receive better inputs if you posted your problems on the Bottlehead forum. Back there, you would be asked if your resistance checks and voltage checks were fine. Were they ? If the noise is only in one channel, then you have a cold solder joint in the signal path of this channel, or sometimes (but it's a rare sometimes) a bad tube. You could try the chopstick test : the test for the hardcore diy guys. Take a wooden stick (wooden, nothing else) and try to poke different connections inside your crack to find the one that makes the most noise in your headphone. There, you will find your cold solder joint or bad component.
> 
> Good luck!


 

 +1 The Bottlehead forum is definitely the best place to problem solve


----------



## UmustBKidn

atraf said:


> Thank you for this information, I guess that leaves me with the choice between Valhalla and the BH, the Valhalla just seem like the safer way to go DYI wise :\
> I am looking for something that will really brings out the bass capabilities of the HD650.. I heard them with Naim DAC-V1 it was freaking amazing, only if I was richer
> 
> Since the Naim is a SS do you think it will be hard to find a Tube amp with same sound signature bass wise?


 
  
 No idea, not even going to attempt to speculate.
  
 The Schiit Valhalla would be a fine choice if you don't care to attempt a Crack build, or don't care to pay someone else to build one for you. I have great respect for all Schiit gear. After a year of reading this website (yeah, it took that long), I decided on buying and building a Crack when time and finances permit, and because soldering doesn't scare me (and saving a few bucks appeals to me). It helps that I have already accumulated a crapton of 12AU7 tubes for my cheap hybrid amps 
	

	
	
		
		

		
			





 But if I were in the position of not wanting (or being able) to solder up a kit, then the Valhalla would be an obvious choice, for this price range.


----------



## Swolern

Just finished Crack build.
  
 Have a problem with low volume output.
  
  
 Edit:
 Haha. Figured it out!!!
  
 SOUNDS AMAZING!!!!!!


----------



## skeptic

Hey swolern - it sounds like something isn't quite right with your setup at present, notwithstanding that the voltages are checking out.  My crack gets very loud with my hd800's without turning the pot very far at all - and unless my memory is failing me, the same held true before I upgraded my pot.  Several members in this thread have reported using inline attenuators, inserted between their rca's and crack input jacks, in order to reduce volume and provide more of a range of motion on their pots.  The amp also should have a dead black background, although some 6as7/6080's are better than others in this regard.
  
 Do you have a different source - ordinary CD player or something you can try with the amp just to eliminate the possibility that this has something to do with software or the rca/lineout on your essence one?


----------



## Swolern

skeptic said:


> Hey swolern - it sounds like something isn't quite right with your setup at present, notwithstanding that the voltages are checking out.  My crack gets very loud with my hd800's without turning the pot very far at all - and unless my memory is failing me, the same held true before I upgraded my pot.  Several members in this thread have reported using inline attenuators, inserted between their rca's and crack input jacks, in order to reduce volume and provide more of a range of motion on their pots.  The amp also should have a dead black background, although some 6as7/6080's are better than others in this regard.
> 
> Do you have a different source - ordinary CD player or something you can try with the amp just to eliminate the possibility that this has something to do with software or the rca/lineout on your essence one?


 
 Ya my volume problem was pretty dumb. I didnt know my E1 had a different volume adjustment for the RCA line out as i have never used it before, it was set to about 25%. Whats weird is after i turned up the RCA output volume the background noise is gone also.


----------



## skeptic

Nice!  Glad to hear you got it sorted out!


----------



## Swolern

Thanks Skeptic.
  
 What are you guys experience with the Speedball. I bought it with my Crack, but I wanted to try out the Crack without the Speedball first. How much better does it get? It sounds so good already!!!!


----------



## JamieMcC

swolern said:


> Thanks Skeptic.
> 
> What are you guys experience with the Speedball. I bought it with my Crack, but I wanted to try out the Crack without the Speedball first. How much better does it get? It sounds so good already!!!!


 
  
 It does exactly what it say on the Bottlehead product page
  
 " The most immediate thing you will notice is a better sense of clarity. Things get tighter and quicker, bass and midrange get cleaner and more dynamic sounding, and the background gets more quiet. As with all of our upgrade kits, the improvement is easily heard"


----------



## Swolern

jamiemcc said:


> It does exactly what it say on the Bottlehead product page
> 
> " The most immediate thing you will notice is a better sense of clarity. Things get tighter and quicker, bass and midrange get cleaner and more dynamic sounding, and the background gets more quiet. As with all of our upgrade kits, the improvement is easily heard"


 
 I always trust "real people's" experience here on Headfi, more than a product page. If thats what you heard, thanks for your feedback.


----------



## JamieMcC

I ordered mine at the same time also and it is hard to imagine how the Crack can sound better but it does imo with the Speedball. I was a little daunted at starting it and managed to run my Crack for a week without it then curiosity got the better of me in the end it came together quicker and easier than I first thought.


----------



## pdrm360

swolern said:


> jamiemcc said:
> 
> 
> > It does exactly what it say on the Bottlehead product page
> ...


 
  
 But don't expect a big day/night difference, IMO.


----------



## Nic Rhodes

The difference is substantial and worthwhile imho, far more than my cap, attenuator and valve changes.


----------



## Loquah

nic rhodes said:


> The difference is substantial and worthwhile imho, far more than my cap, attenuator and valve changes.


 
  
 +1 - night and day, no, but easily noticeable? Yes.
  
 Perhaps it's like dawn and day instead of night and day


----------



## Draygonn

swolern said:


> Just finished Crack build.
> 
> SOUNDS AMAZING!!!!!!


----------



## Mahdi8

grindingthud said:


> Looks like an RCA rebrand... Is there an octagon on the glass with 6AS7G in it somewhere? Nice looking box too!


 
 No there is no octagon on the glass. The glass doesn't have any marking on it


loquah said:


> It certainly looks right. I wonder if Mullard made it or if it's a re-badge.
> 
> How does it sound compared to your other 6AS7G?


 
 Compared to svetlana winged C 6as7g I consider the mullard to be brighter with really extended highs, vocals are slightly recessed, bass is tight but really punchy, sound stage is quite wide with nice instrument separation, but detail wise I will put the svetlana to be better because of more pronounced mids. RCA 6AS7G is supposed to be warm with thick bass and rolled of treble, and this tube doesn't sound like any of that signature.


----------



## Klots

Hello. I received my valab 23 step 50k attenuator and I have a question. The PCB where to wires from rca-s connect is different than the PCB shown in ebay. 
  
 http://www.ebay.com/itm/Valab-23-Step-Ladder-Type-Attenuator-Potentiometer-50K-Log-Stereo-/291116689572?pt=AU_Electronics_Audio_Amplifiers&hash=item43c7e828a4
  
 And my PCB
  

  
 Would the L-R channel and 1-23 number difference change anything?


----------



## JamieMcC

klots said:


> Hello. I received my valab 23 step 50k attenuator and I have a question. The PCB where to wires from rca-s connect is different than the PCB shown in ebay.
> 
> http://www.ebay.com/itm/Valab-23-Step-Ladder-Type-Attenuator-Potentiometer-50K-Log-Stereo-/291116689572?pt=AU_Electronics_Audio_Amplifiers&hash=item43c7e828a4
> 
> ...


 
  
 Here is a pic of mine what you cant see in the first pic is the short jumper I have between the left and right ground connections its hidden beneath the black wire. Second pic shows it


----------



## ffivaz

jamiemcc said:


> Here is a pic of mine what you cant see in the first pic is the short jumper I have between the left and right ground connections its hidden beneath the black wire. Second pic shows it


 
  
 +1 Don't forget to connect the two grounds when you rewire you new pot. If you don't, your Crack will go crazy and become potentially dangerous (some caps aren't discharging anymore at shutdown). half of the Crack's grounding is done through the small wire on Jamies's pot.


----------



## JamieMcC

ffivaz said:


> +1 Don't forget to connect the two grounds when you rewire you new pot. If you don't, your Crack will go crazy and become potentially dangerous (some caps aren't discharging anymore at shutdown). half of the Crack's grounding is done through the small wire on Jamies's pot.


 
 I believe the discharging of the capacitors is faintly audible for about a minute after the power is turned off through the headphones. At least that's what I have always thought the sound I was hearing was?


----------



## ffivaz

I had the experience two weeks ago. I forgot to bridge the two grounds on a new pot. My resistance went haywire, and I still decided I could start the Crack. Bad move. Even after shutdown and power cable removal, I got snapped when touching something inside. Something I never experienced before : the resistors (the 270R in the PS I think) work fine and discharge the caps in a couple of seconds (if your grounding is correct!).


----------



## Mahdi8

jamiemcc said:


> Here is a pic of mine what you cant see in the first pic is the short jumper I have between the left and right ground connections its hidden beneath the black wire. Second pic shows it




Do you have to modify the top plate to fit the new valab pot?or the existing hole fits?


----------



## JamieMcC

mahdi8 said:


> Do you have to modify the top plate to fit the new valab pot?or the existing hole fits?


 
  
 Yes you need to make the big hole about 1.5 mm larger and the little orientating  hole for the plastic pin needs elongating a dremel made it a quick and easy job of it.


----------



## dante020

klots said:


> Hello. I received my valab 23 step 50k attenuator and I have a question. The PCB where to wires from rca-s connect is different than the PCB shown in ebay.
> 
> http://www.ebay.com/itm/Valab-23-Step-Ladder-Type-Attenuator-Potentiometer-50K-Log-Stereo-/291116689572?pt=AU_Electronics_Audio_Amplifiers&hash=item43c7e828a4
> 
> ...


 
  
 As several people have already stated, make sure you jump the ground terminals - I have first hand experience with forgetting this little step, and I'll just say that the results can be quite shocking!


----------



## Aeolus Kratos

I got delivery today.....
  
 And it's a pair of the Mullard CV4003 12AU7. Couldn't be happier with them


----------



## Klots

dante020 said:


> As several people have already stated, make sure you jump the ground terminals - I have first hand experience with forgetting this little step, and I'll just say that the results can be quite shocking!


 
 Yea I jumped the terminals  Btw the PCB I have on my valab pot the R and L channels are wrong. R=L and L=R. Somebody made a mistake building the pot or just the plate is wrong. But that is not a big deal and the crack sounds wonderful  Received my CBS 5814A tube too. Happy days


----------



## MoatsArt

Crack ordered. Mod parts starting to arrive. Anticipation growing....


----------



## MattTCG

^^ did you get custom caps?


----------



## MoatsArt

Have ordered the following
Obbligato gold 94 uF
Teflon 10uF
Jupiter Beeswax 1uF
Solen 220uF


----------



## dante020

Seeing some of the finishes on these amps has really got me wanting to build another one, but this time anticipating the oversights and after-thoughts from the first time around. I really like the look of the hammered paint that everyone's using


----------



## Mak333

It's been about 3-4 years now with the Crack amp since I had built it.  I noticed some infrequent and random crackling in the left channel over the past few months.  Switched out tubes and that didn't make a difference.  So I decided to take a paint brush and touch all of the connection points, figuring some dust or hair may be setting it off.  All appears to be fine now.  Just wanted to post my thoughts if anyone else comes across this... I suppose it's the trade off of building a great sounding kit without a full enclosure.
  
 Maybe one of these days I'll build a different base for it, who knows!


----------



## Doc B.

Any enclosure would still need cooling slots or holes that would allow dust in. Cleaning out any audio gear every few years is a very good idea. You should have seen the dust buildup on the insides of some of the 60 year old antique radios I have restored. Scary.


----------



## skeptic

moatsart said:


> Have ordered the following
> Obbligato gold 94 uF
> Teflon 10uF
> Jupiter Beeswax 1uF
> Solen 220uF


 
  
 Wow - that's some combo!  Are there 94uF Obbligato golds now or are you doubling up on the 47's on each channel?


----------



## MoatsArt

Doubling up on 47 uF for each channel (94 / channel)

Teflons are RTI Electronics

can't get Jupiter HTs atm, so they will have to wait.

The Crack of Dawn MkII has to compete against MkI for capacitor real estate boasting rights!


----------



## JamieMcC

moatsart said:


> Doubling up on 47 uF for each channel (94 / channel)
> 
> Teflons are RTI Electronics
> 
> ...


 
  
 Get those RTI teflons in the burn in rig asap the first 450hrs have been a bit of a torture test fitting them while they are not burned in fully. With about 500hrs on mine so far, though massively improved and now listenable the sonics are swinging from amazing to the bass sounding a loose. I wondered if it was smearing at first but as it comes and goes I don't think it is just need more burn in time perhaps due to the lower loadings with a head-amp.  Hearing lots of new things that I had not noticed before such as backing vocals splitting into distinct individuals new instrument etc. But it has been frustrating due to taking so long.


----------



## MoatsArt

500 hour burn in? Crikey!


----------



## JamieMcC

Nice surprise today a courier dropped off a package containing one of my favourite tubes types for the Crack. Six nos Mullard 6080's 
	

	
	
		
		

		
		
	


	




 As a relative newbie to tubes I find  unwrapping a original nos tube is still a bit of a novelty!


----------



## spacequeen7

jamiemcc said:


> Nice surprise today a courier dropped off a package containing one of my favourite tubes types for the Crack. Six nos Mullard 6080's
> 
> 
> 
> ...


 
 nice ....want


----------



## Nic Rhodes

Where did you get them from Jamie? Nice...


----------



## JamieMcC

Nic from a contact I made via a ebay purchase.


----------



## i luvmusic 2

I'am thinking of this amp to be my first DIY Tube Amp.
 How does this amp perform with AKG Q70!?
 Can you roll 6SN7 tubes with this Amp?Thank you!


----------



## MoatsArt

This amp is not designed for headphones with impedence as low as the AKG Q/K70x.

It can be used with 6SN7 tubes either thriugh modding or use of a tube converter. Use of a converter is less than optimal in my experience as it adds noise to tbe signal.

Cheers

Nathan


----------



## i luvmusic 2

moatsart said:


> This amp is not designed for headphones with impedence as low as the AKG Q/K70x.
> 
> It can be used with 6SN7 tubes either thriugh modding or use of a tube converter. Use of a converter is less than optimal in my experience as it adds noise to tbe signal.
> 
> ...


 
 Thank You!
 Did you used a external Power Supply?
 Noise is used to be my problem when rolling 6SN7 to my L? MK 3 until i used a DC external power supply and connect the  chassis ground to the external power supply chassis then the noise disapeared the amp is dead queit now i hope this will work with Crack.


----------



## ModestMeowth

doc b. said:


> Any enclosure would still need cooling slots or holes that would allow dust in. Cleaning out any audio gear every few years is a very good idea. You should have seen the dust buildup on the insides of some of the 60 year old antique radios I have restored. Scary.


 
 would a small computer fan fitted be possible to help cool?


----------



## dsound

modestmeowth said:


> Not knowing much about electronics, other than building computers, would a small computer fan fitted be possible to help cool?


 
 IMO, a vent is a better solution because fans can often introduce unwanted noise into your listening environment.  That's why you typically don't see fans on home-stereo equipment (although I do have some monstrous fans on my PA amplifiers).
  
 Just my 2 cents.  Good luck with whatever route you choose


----------



## Koolpep

moatsart said:


> This amp is not designed for headphones with impedence as low as the AKG Q/K70x.
> 
> It can be used with 6SN7 tubes either thriugh modding or use of a tube converter. Use of a converter is less than optimal in my experience as it adds noise to tbe signal.
> 
> ...


 
  
 Hi, indeed. The amp has an output impedance of 150 Ohms. I usually listen to my T90 (250 Ohm) on them (have the crack on loan from punit). Today I thought, let's try some low impedance headphones and see what happens. And I am quite surprised.
  
 Next to no noise and pretty clear sounding on a Momentum Over Ear (18 Ohms !!) - duh? I never thought this would work but I actually like the result a lot. Very surprising....
  
 Cheers,
 K


----------



## Loquah

That's my old Crack!! 

Strangely, I have a friend who loves the low impedance TH-900s with the Crack.


----------



## punit

loquah said:


> That's my old Crack!!
> 
> 
> 
> ...


 

 Yes, I always share my drugs with my friends 
	

	
	
		
		

		
		
	


	




. Does your friend have another good amp for the TH-900 comparison ? They do not sound bad with the Crack but when you play the TH900 from a better suited amp (Meier Classic & WA22 in my case) you know what you are missing, especially at higher volumes.


----------



## Koolpep

loquah said:


> That's my old Crack!!
> 
> 
> 
> ...


 
  
 You old Crack says: Hi!
  
 I hope I can convince @punit to sell this beauty to me one day. I tried to distract him with loaning him some of my headphones, let's see if this diverting tactic works out


----------



## Loquah

He has a Soloist, but prefers them with Crack. Maybe he should try my Mainline...


----------



## DutchGFX

loquah said:


> He has a Soloist, but prefers them with Crack. Maybe he should try my Mainline...




I recently started to prefer the Crack to the Soloist for the T1. The Burson isthe better amp, but the T1 has such great synergy with the Crack. I don't have the speedball either.

I think the Burson is the best all arounder I have heard yet, I have only heard the GSX-2 once and the Taurus once, and I haven't gotten to play with a Cavalli amp much, and haven't heard a Beta22, but I still think the Burson is an excellent amp. I just happen to prefer the Crack for some reason


----------



## atraf

Need your help, after trying to contact BottleHead with no success I hope you guys can give me an answer.
 1) When they send the package of the DIY kit how is the package content described ( what is written on the box)  an Amplifier or Electronical Parts of some sort? ( asking because there is a 32% tax in my country on amps compared to 18 on just electronic...big different in price)
 2) What is the size weight of the package? 
3) is it possible to bring something like that on a plane with me? or is that to risky, they may  think I am carrying a bomb or something, don't want that hassle.
 4) How is the BottleHead support? I already have a lot of concerns about DIY as it is and they don't seem too keen to help me with my questions, its been quite a while since i tried contacting them but got no answer.
  
  
Thanks.


----------



## atomicbob

hot sounds from a hot Crack - Chatham 6AS7g and RCA clear top 12AU7:
  

  
 Rest of chain includes a Concero HD and HD800 / T90 / T1 cans.


----------



## Serenitty

atomicbob said:


> hot sounds from a hot Crack - Chatham 6AS7g and RCA clear top 12AU7:
> 
> 
> 
> ...




How do you like the concero with the T1?


----------



## mcandmar

Oh that is really cool to see, more of those pics please


----------



## atomicbob

serenitty said:


> How do you like the concero with the T1?


 
 The Concero HD has a very low THD+noise floor, very low jitter and gives a great presentation of sound stage, depth, transient response, etc. I have a preference for OTL amps driving high impedance headphones. Those three listed are my pick, each offering something different enough from the others to keep them all. The ConceroHD -> Crack -> T1 is a very addictive recreational listening system.


----------



## spacequeen7

two little mods before it's all "finished"..(special thanks to kscwuzhere @ BH for the voltage mod )
 http://bottlehead.com/smf/index.php/topic,5989.30.html
 ,24 stepper is tiny bit on the dark side (was expecting this ) and since it improved the noise and sound quality (around 7% sound )it's a keeper


----------



## skeptic

That's awesome! Well done!


----------



## JamieMcC

atraf said:


> Need your help, after trying to contact BottleHead with no success I hope you guys can give me an answer.
> 1) When they send the package of the DIY kit how is the package content described ( what is written on the box)  an Amplifier or Electronical Parts of some sort? ( asking because there is a 32% tax in my country on amps compared to 18 on just electronic...big different in price)
> 2) What is the size weight of the package?
> 3) is it possible to bring something like that on a plane with me? or is that to risky, they may  think I am carrying a bomb or something, don't want that hassle.
> ...


 
  
 Ok  where to start
  
 1 I am pretty sure mine shipped with the description listed as Electronic parts or words to that effect on the customs form also the value was given with what I am guessing was the component value and not the kit value which really helps with duty fees.
  
 2 Its roughly 10x12x6 without measuring weight not sure but I hope someone else will chip in with the correct figures
  
 3 Not sure
  
 4 Superb probably the best do not be concerned here. 
  
 Register on the Bottlehead Forum and post your questions there in the Crack section or when registered you can also send Doc a private message and I am positive they will be quickly answered by Bottlehead.
  
 A little while back they changed their website host and updated their website it wasn't a smooth transition so maybe your email was lost or overlooked it was pretty chaotic for about a week or so.


----------



## atomicbob

spacequeen7 said:


> two little mods before it's all "finished"..(special thanks to kscwuzhere @ BH for the voltage mod )
> http://bottlehead.com/smf/index.php/topic,5989.30.html
> ,24 stepper is tiny bit on the dark side (was expecting this ) and since it improved the noise and sound quality (around 7% sound )it's a keeper


 
 Awesome looking mods spacequeen7!


----------



## atomicbob

mcandmar said:


> Oh that is really cool to see, more of those pics please


 
 Happy to oblige. Here are a few more:


----------



## Swolern

loquah said:


> That's my old Crack!!
> 
> 
> 
> ...


 
 I disagree with that one. The Crack sounds ok with the TH-900 at low-medium volumes, but when you start to turn it up, SQ gets distorted, pretty bad. The TH-900 sounds tons better with my Essence One amp/dac. Now the Crack with the HD800!!! Ooohhhhh yeah!!!!


----------



## Loquah

I was certainly surprised to hear his opinion.

I'm building him a Crack soon (he's previously used his friend's) so I hope he's not disappointed.

Edit: he has T1s so that's guaranteed awesome even if TH900s aren't.


----------



## atraf

jamiemcc said:


> Ok  where to start
> 
> 1 I am pretty sure mine shipped with the description listed as Electronic parts or words to that effect on the customs form also the value was given with what I am guessing was the component value and not the kit value which really helps with duty fees.
> 
> ...


 
 Thanks, you helped me a lot.
 about '1' do you remember how much was it in $ ? I mean what is the difference between component value and kit value ?
  
 I will try BottleHead forum for further details.


----------



## Aeolus Kratos

Just got the Quickie today, Quickie - Crack - HD650, the initial impression is great. The Quickie really makes the bass tighter and cleaner. The mid is more presented and the imaging is improved noticeably.
  
 Thanks Doc B and Bottlehead team for such an amazing product!


----------



## bleudeciel16

Guess what I'm doing tonight???


----------



## MoatsArt

Getting drunk and playing with electricity.


----------



## bleudeciel16

moatsart said:


> Getting drunk and playing with electricity.


 
  
 DING DING DING we have a winner
  
 But really, not drunk... I can't drink IPA's that fast.  I'd get sick before I'd get drunk lol.


----------



## spacequeen7

I think you got it all ..nice


----------



## bleudeciel16

spacequeen7 said:


> I think you got it all ..nice


 
  
 not all, but enough for my wife not to like my expensive hobbies lol.  went to school for EE, became a DBA, so since I can't get my EE fix in at work, I do it as a hobby.  fun stuff!


----------



## ItsLarry

Some nice looking builds in here! Any suggestions for a 6 month old kit(+SB) that hasn't experienced anything other than stock tubes(6080 & 12AU7)? Paired with HD600 and Modi.


----------



## olegausany

Get Tungsol/Chatham 5998

Sent from my LG-V500 using Tapatalk


----------



## Keithpgdrb

olegausany said:


> Get Tungsol/Chatham 5998
> 
> Sent from my LG-V500 using Tapatalk


 
 Yep.  that should be your first move.


----------



## MoatsArt

Heads up for 5998

http://www.ebay.com.au/itm/221423004925?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649


----------



## JamieMcC

itslarry said:


> Some nice looking builds in here! Any suggestions for a 6 month old kit(+SB) that hasn't experienced anything other than stock tubes(6080 & 12AU7)? Paired with HD600 and Modi.


 

 Install a $30 stepped attenuator
  
 Loquah's recent post
  
 "Update Time!
  
 I installed a new attenuator the other night in my Bottlehead S.E.X. and have now had a chance to listen to the setup for a little while. There's no doubt that it's a significant improvement. As others have reported, the key differences from the stock potentiometer are better transparency and detail. I feel like the textures of recordings and things like breathiness in vocals, etc. are now more accurately and clearly rendered through the S.E.X."
  
 works well with the Crack also and have one fitted in mine
  
 http://www.head-fi.org/t/683012/bottlehead-amplifier-discussion-comparison-thread-crack-sex-mainline/570


----------



## MoatsArt

An excellent, cheap 12AU7 is the RCA Clear Top.


----------



## MoatsArt

...


----------



## JamieMcC

moatsart said:


> ...


 
  
 Morse code?


----------



## MoatsArt

... --- ...

Mistake. Posted in wrong thread and deleted.

:redface:

Red face has been my favourite emoticon today.


----------



## MoatsArt

That 7802WB arrived yet Jamie? Looking forward to impressions.

Am planning to mod the Crack to take 12SN7GTs as input. I have too much time on my hands while I wait for the kit.


----------



## JamieMcC

moatsart said:


> That 7802WB arrived yet Jamie? Looking forward to impressions.
> 
> Am planning to mod the Crack to take 12SN7GTs as input. I have too much time on my hands while I wait for the kit.


 

 Hi Nathan mine arrived well packed and works perfectly sonically its very much the same as my 6080wb


----------



## MoatsArt

The 6080WB produces a lower output impedance I believe due to the difference in mutual conductance from a 6080. It would be interesting to see how it goes with lower impedance phones, like the K702.

Do you have any cans like this hanging around with impedance in the 60-80 ohm range? It would be interesting to learn if you can hear a difference between the 6080 and 7802. The 5998 lies somewhere in between, I think, in terms of mutual conductance and output impedance.


----------



## JamieMcC

The only low phones I have are the ATH W1000X which are 42ohm but they happen to be double boxed up for international shipping 
	

	
	
		
		

		
			





 and I don't fancy unwrapping them!


----------



## MoatsArt

:redface:


----------



## spacequeen7

Interesting that no one is mentioning TS 7236 ,I was recently looking for worthy  5998 replacement (actually combination of both -power/driver tube) and I think this tube paired with Tungsram or Amperex E80CC (tried various 6SN7s and E80CC Philips,Siemens )   sounds very good 
  
mandatory pic


----------



## i luvmusic 2

Too many amps to choose from but The Crack is the only one that catching a lot of my attentions specially it will be my first DIY tube Amp.


----------



## .Sup

i luvmusic 2 said:


> Too many amps to choose from but The Crack is the only one that catching a lot of my attentions specially it will be my first DIY tube Amp.



It was my first DIY tube amp also.


----------



## i luvmusic 2

.sup said:


> It was my first DIY tube amp also.


 
 How was the build did it go according to plan?


----------



## i luvmusic 2

In your opinion was it easy enough for a first timer?


----------



## Keithpgdrb

I think a first timer could absolutely do it.  One thing I will say, speaking from experience.  wire routing matters.  I was chasing down a humm in my crack, only to find that I routed a wire under a tube instead of around it.    Yes, it was easier to do it my way, but easier isn't always better. lol. 
  
 Having said that, just follow the EASY to follow directions and reference all the pictures.  If something isn't right, the bottlehead forums are an easy place to find the answer.
  
 and building it is fun.


----------



## DutchGFX

Was my first P2P project (point to point) and it was easy. I enjoyed it so much I'm actually building an OTL P2P from headwize, its going to be a challenge.


----------



## Keithpgdrb

Which project are you doing?


----------



## DutchGFX

A modified version of the "Top Level OTL"


----------



## .Sup

i luvmusic 2 said:


> How was the build did it go according to plan?



Yes, only the tube was faulty and I got channel imbalance. I did some cables before this, thats all. Manual is fantastic, even for someone like me that doesn't speak English as first language. I really enjoyed the build and this thing is so amazing sound wise. Haven't done any tube rolling, am trying to find a TS5998 atm.


----------



## Mak333

i luvmusic 2 said:


> In your opinion was it easy enough for a first timer?


 

 Not to sound like an advertisement, but Bottlehead states this front and center (well, right justified) on their main page of their website.  I hadn't soldered in my life, and have very little experience with DIY in general.  I completed the Crack amp in two evenings (roughly 10 hours total) from the time I opened the box, to the time I was testing voltages.  Everything checked out fine, no hiccups.
  
 I then installed Speedball a year later and it went even smoother.
  
 The instructions are spelled out word for word, step by step; very easy to follow.
  
 If you can build a Lego pirate ship, you can build this amplifier.


----------



## Loquah

mak333 said:


> Not to sound like an advertisement, but Bottlehead states this front and center (well, right justified) on their main page of their website.  I hadn't soldered in my life, and have very little experience with DIY in general.  I completed the Crack amp in two evenings (roughly 10 hours total) from the time I opened the box, to the time I was testing voltages.  Everything checked out fine, no hiccups.
> 
> I then installed Speedball a year later and it went even smoother.
> 
> ...


 
  
 +1 - very, very straightforward and the instructions are literally perfect to follow between the great descriptions and the images provided


----------



## atomicbob

I am an EE in profession and can say Doc has done a great job of the instructions. They are equal to the quality of the design topology and resulting sound quality when the Crack is built according to the instructions. This amp is second only to my Zana Deux SE in my collection. Having both, I still spend a lot of time with a Crack + HD800 / T90 / T1 fed by a Concero HD. Chatham 6AS7g and RCA clear top. Great sounding system.


----------



## Doc B.

mak333 said:


> If you can build a Lego pirate ship, you can build this amplifier.




I love that.


----------



## Armaegis

I really want to see somebody build the amp into a lego chassis now...
  
 edit: uh, then again, some of those ships ain't nothin' to scoff at...
  


Spoiler: Warning: Spoiler!



http://www.brickshelf.com/cgi-bin/gallery.cgi?i=1227646


----------



## i luvmusic 2

THANKS GUYS!
 I'll be back home in 2 months now i can't wait to comeback.
 I hate LEGO too many pieces to put together i hope CRACK don't have 1000+ pcs. just kidding...


----------



## skypop

In case anyone is interested I am selling my Crack Amp,No time to listen anymore with the new Baby. It has the Speedball option installed and Solen 100 micro fared caps part number PB-MKP-FC,Vampire Connecters,Elma Stepped Volume Control, and A Tung Sol 5998 and A Phillips 12BH7. I am also listing this in the for sale section and I will Put the price there.Sounds Great as you all know this amp,i've had it for about 1 year,Thanks for any interest. I am selling a mint condition Senn HD650 with Toxic cable also if interested.


----------



## icc900

Helpful...Thanks for sharing.


----------



## skeptic

icc900 said:


> Helpful...Thanks for sharing.


 
  
 You do realize your post history is publicly visible right?  So we can all tell you've posted this same exact statement in about ~20 different threads and nothing else?  http://www.head-fi.org/forums/posts/by_user/id/381731


----------



## bigfatpaulie

skeptic said:


> You do realize your post history is publicly visible right?  So we can all tell you've posted this same exact statement in about ~20 different threads and nothing else?  http://www.head-fi.org/forums/posts/by_user/id/381731


 
  
  
 Helpful...Thanks for sharing.


----------



## skypop

Amp is sold,thanks for interest. Hopefully i'll get another one in A year or so.


----------



## Tequilasunriser

skeptic said:


> You do realize your post history is publicly visible right?  So we can all tell you've posted this same exact statement in about ~20 different threads and nothing else?  http://www.head-fi.org/forums/posts/by_user/id/381731


 
 My guess is that they're subscribing to threads the lazy way.


----------



## Armaegis

Either that or a very patient bot building up post count before spamming.


----------



## Koolpep

My guess is that he/she is racking up the 50 posts to use the sales forum....
  
 Cheers,
 K


----------



## guirr

I'm not too into the DIY... is there someplace where I could get it made for me?
  
 thanks!


----------



## dante020

I'm itching to do some more mods on my Crack but there isn't a whole lot left. I already have the speedball upgrade as well as Solen 100uF film output caps and a stepped attenuator, along with plenty of tubes. I could probably experiment with bypassing some caps - is there any noticeable benefit from it? Maybe I'm just at the end of the road.


----------



## JamieMcC

dante020 said:


> I'm itching to do some more mods on my Crack but there isn't a whole lot left. I already have the speedball upgrade as well as Solen 100uF film output caps and a stepped attenuator, along with plenty of tubes. I could probably experiment with bypassing some caps - is there any noticeable benefit from it? Maybe I'm just at the end of the road.


 

 Just finished up fitting a Triad choke and swapping out the last electrolytic capacitor in the power supply for a jfx  premium film. Also trying out some K75 100uf PIO capacitors temporarily clipped in with some fly leads.


----------



## dante020

Wow, you aren't messing around. Do film caps for the power supply make a noticeable difference? I have one of them bypassed by a 10uF film cap but that's as far as I've gone so far.


----------



## Keithpgdrb

dante020 said:


> I'm itching to do some more mods on my Crack but there isn't a whole lot left. I already have the speedball upgrade as well as Solen 100uF film output caps and a stepped attenuator, along with plenty of tubes. I could probably experiment with bypassing some caps - is there any noticeable benefit from it? Maybe I'm just at the end of the road.


 
 have you noticed any difference in sound with the output caps or attenuator?  I would think the attenuator would just be cosmetic.  but who am I to say.  love to hear your input.


----------



## dante020

keithpgdrb said:


> have you noticed any difference in sound with the output caps or attenuator?  I would think the attenuator would just be cosmetic.  but who am I to say.  love to hear your input.


 
 While there could be some bias since I can't do a side-by side (and I like to think my money wasn't wasted), I think they both have some subtle effect. The caps cleaned up the sound and increased the bass response a bit. As for the attenuator, I was having a slight channel imbalance at very low levels which is gone. It also seems like there might a bit more clarity/transparency but I could just be imagining things.


----------



## Keithpgdrb

I'll have to look into this. if the sound can be improved by simply changing some caps, I'm all in. A nicer volume pot would be sweet as well. could you post up a pic maybe?


----------



## dante020

keithpgdrb said:


> I'll have to look into this. if the sound can be improved by simply changing some caps, I'm all in. A nicer volume pot would be sweet as well. could you post up a pic maybe?


 
 It's pretty similar to what a lot of other's have already done. Basically just some big film output caps, a Valab 23 step attenuator, and a small bypass film cap on one of the power caps. I also replaced the braided input wire with some shielded Mogami mic cable to reduce interference. I'll post pics tonight when I get a chance.


----------



## JamieMcC

The Valab or Dale 23 step attenuator have to be one of the most cost effective upgrades for the Crack imo.
  
 Early days with the choke and the big 200uf film will take around 100hrs to burn in.
  
 I will say with the choke and 200uf capacitor a few things are quiet noticeable straight away. 
  
 1 Music has a very black background
 2 Bass has tightened up there is more of it and its has some good punch and impact while staying controlled.
 3 Music has more weight to it
 4 Microphonics caused by say putting a cup down on or tapping the table or the headphone cable brushing against the amp this has improved with some of my more sensitive tubes.


----------



## Keithpgdrb

I'll have to look more closely into some of these upgrades.  I like the sound of what you guys are saying.  Interesting about the mic cable.  I've got a  bunch of busted mic cables laying around.  I should use them for something.


----------



## DutchGFX

I don't know if I posted this already. But I bought a few GE, RCA, and Tung-Sol 6080's. And a pair of RcA Clear Tops. I decided that the best sound is still with my Chatham and stock 12AU7, which is kind of annoying lol. But oh well. The cleartops look moderately cool at least


----------



## MoatsArt

I see someone has a Bendix 6080WB with solid graphite plates for sale on eBay. A very nice tube.


----------



## ModestMeowth

moatsart said:


> I see someone has a Bendix 6080WB with solid graphite plates for sale on eBay. A very nice tube.


 
 I hear the slotted are the wanted graphite's, opinion?


----------



## spacequeen7

modestmeowth said:


> I hear the slotted are the wanted graphite's, opinion?


 
 correct


----------



## ModestMeowth

spacequeen7 said:


> correct


 
 Would it be wise to pass up the solid and wait for a slotted to turn up?


----------



## MoatsArt

All graphite 6080WB are wanted. Some prefer the slotted.

Don't swallow tube dogma. Buy and try. If you like them, keep them. If you don't, sell them on. A lot has to do with the other elements in your chain. Tube rolling in the Crack only offers subtle differences.


----------



## Aeolus Kratos

moatsart said:


> I see someone has a Bendix 6080WB with solid graphite plates for sale on eBay. A very nice tube.


 
 Here is the link to the Bendix selling thread, just in case someone needs it.
  
 http://www.ebay.com/itm/Tung-sol-Bendix-6080-WB-6AS7G-Tube-tested-/121329031218?pt=UK_Sound_Vision_Valves_Vacuum_Tubes&hash=item1c3fc61832
  
 But to be honest, this is not the best price you can get for this tube. I personally had my Bendix Slotted Graphite Plates tube for around 45-55$


----------



## JamieMcC

aeolus kratos said:


> I personally had my Bendix Slotted Graphite Plates tube for around 45-55$


 
  
 You did well on them those slotted plates the last two pairs I saw on ebay both went for around US $285.00 plus shipping which seems more the norm, The Graphite plates don't come up very often and are getting harder to find.  Let me know if you want to sell one I would be happy to give you what you paid!
  
http://www.ebay.co.uk/itm/2-6080WB-Tubes-BENDIX-USA-Tested-Ham-Military-audio-NOS-TE-46-/301114339414?nma=true&si=4J0G5qrFG6xso42FpmgYsSLgk70%253D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557


----------



## Tequilasunriser

Don't get carried away tube rolling. Stop to enjoy the music.


----------



## punit

tequilasunriser said:


> Don't get carried away tube rolling. Stop to enjoy the music.


 

 25 years ago (when I had no knowledge about equipment or being an "audiophile") I used to enjoy the music  from my Sony Walkman & bundled HP's *as much as I do today* from my 15 odd Hp's  + 4 amps + 40+ tubes. Only difference is now I also enjoy my equipment as much as I enjoy my music. 
	

	
	
		
		

		
		
	


	




 
 Music is an undying passion, Equipment is the associated hobby.


----------



## MattTCG

punit said:


> 25 years ago (when I had no knowledge about equipment or being an "audiophile") I used to enjoy the music  from my Sony Walkman & bundled HP's *as much as I do today* from my 15 odd Hp's  + 4 amps + 40+ tubes. Only difference is now I also enjoy my equipment as much as I enjoy my music.
> 
> 
> 
> ...


 
  
 Well put. Gear preoccupation is almost and unavoidable association for this hobby.


----------



## punit

I was just thinking to my self would my passion for music have decreased if I had not discovered "audiophile" equipment  & was still listening to music on an ipod  --- NO.
  
 Equipment has not made me love Music more (I love "On the Turning Away" with the same passion whether on the Sony Walkman / Ipod or on the Crack + HD 800) , but Music has made me love equipment more because of the various shades with which it can present music. If you get my drift.


----------



## MattTCG

I love live "unplugged" music most of all. The gear I buy gets me closer to that experience. Unfortunately live music happens only about one time a year now.


----------



## punit

Funny thing is , I go to a lot of concerts  (been to Texas, Santana, Lionel Richie this month, Pet Shop Boys & Fat Boy Slim next week.....) & some times the sound set up is not that great & I actually go "Hmm... sounds better on my Headphones" 
	

	
	
		
		

		
			





 
  
 But even when your audiophile inner critic is irritated with the sound engineer for not properly tuning the Bass at a concert, nothing beats the communal sharing of passion & love for music with thousands of people at a concert.


----------



## Armaegis

matttcg said:


> Well put. Gear preoccupation is almost and unavoidable association for this hobby.


 
  
 For some, it *is* the hobby...


----------



## JamieMcC

Compared to the cost of a few pints down the pub now and take away supper purchasing a few tubes to roll once in a while is very much the lesser of to evils.


----------



## Keithpgdrb

punit said:


> Funny thing is , I go to a lot of concerts  (been to Texas, Santana, Lionel Richie this month, Pet Shop Boys & Fat Boy Slim next week.....) & some times the sound set up is not that great & I actually go "Hmm... sounds better on my Headphones"
> 
> 
> 
> ...


 
 this is often the case. Live mixing is an art that is largely lost.  But I agree.   hearing the artist deliver live is worth listening to the stoned guy running the board. 
  
 I always try to put myself near the board, because that is where the best sound should be.  I love it when You see the sound guy standing in front of the board, "giving a good listen", and he seems to approve of what he hears.  so often there are major problems with the mix, and the guy just stands there nodding like he just created light.  Ugh, the curse that is being a musician and audio enthusiast.


----------



## ModestMeowth

http://www.partsconnexion.com/ is having the 20% off sale so I want to get in on it but quite overwhelmed with all the options. Can someone give me the exact caps I should buy?


----------



## Zashoomin

modestmeowth said:


> http://www.partsconnexion.com/ is having the 20% off sale so I want to get in on it but quite overwhelmed with all the options. Can someone give me the exact caps I should buy?


 
 You will need 100uf caps rated at a minimum 300V.  I believe 200V go through the cap.  Please feel free for anyone to correct me.  So you need a 300V or above, 100uf cap.


----------



## DutchGFX

200V go *across the cap is surely what you meant  haha

Side note, I have no clue about the actual voltage. Just thought I would clarify that haha 

I also want to know some mods to do, so any cap upgrades would be nice.


----------



## Doc B.

A 200V rating is fine, but not necessary. We use 160V rated caps in the stock kit and the actual voltage seen is about 75VDC cathode voltage plus the signal voltage, which doesn't go much over 20V max. So 160V rating has plenty of safety margin.


----------



## ModestMeowth

zashoomin said:


> You will need 100uf caps rated at a minimum 300V.  I believe 200V go through the cap.  Please feel free for anyone to correct me.  So you need a 300V or above, 100uf cap.


 
 How many of them? Brand?


----------



## Loquah

modestmeowth said:


> How many of them? Brand?


 
  
 2 caps. Brand is up to you, but Mundorf M-Caps aren't a bad option without getting into "big bucks" territory.


----------



## dante020

Pics of my Crack as promised. Nothing too crazy. Film output caps, film bypass cap on the power supply, shielded mic cable for the RCA input, and a stepped attenuator. Unfortunately at the time I got my caps, the only reasonably priced ones were 400v, and thus, a bit too large. The fit okay but there really isn't room to attach them with zip ties as I intended so they're just hanging freely.


----------



## MattTCG

Looks great!! Love the wood base. Very similar to mine.


----------



## spacequeen7

nice Crack dante !


----------



## atomicbob

Very nice job on the Crack, dante. What value is the film bypass cap on the power supply? Whose stepped attenuator are you using?


----------



## Serenitty

Are these Dayton Audio caps good sounding?  Has anyone used them?
  
 http://www.parts-express.com/dayton-audio-dmpc-100-100uf-250v-polypropylene-capacitor--027-447
  
 i still need to install my speedball and maybe try that 12BH7 I found at work, but I was wondering if these would make a noticeable difference.\
  
 Of course listening to The Wall last night on my T1's I'm not sure if I care.  That sounded really good.  And that's with a Fiio E17 doing the DAC duty...
  
 Thanks


----------



## dante020

atomicbob said:


> Very nice job on the Crack, dante. What value is the film bypass cap on the power supply? Whose stepped attenuator are you using?


 
 Bypass cap is a 10uF Solen, attenuator is a Valab 23 step off eBay.


----------



## .Sup

Very nice, maybe use some hot glue to attach them?


----------



## dante020

I could but honestly they're not going anywhere. I soldered them on directly without any extension wire. They don't move and they're not heavy enough to put strain on anything. I'll probably just leave them.


----------



## Aeolus Kratos

Fantastic job on your Crack, Dante. But you forgot the most important thing, how does it sound? I'd love to hear your impressions after installing these caps


----------



## grrraymond

My SB kit turned up yesterday. Unfortunately, I'm away til Sunday so couldn't make a start on it yet. I was wondering, however, whether I should hold my horses and fit some cap upgrades at the same time? I'm sure I've read that it'd be easier to do all this at once, rather than post-SB.
  
 I also have a Blue Velvet pot sitting there which I'm going to fit. Quite exciting! Also, I can finally run that E80CC without worrying it's going to melt my Crack.


----------



## JamieMcC

grrraymond said:


> My SB kit turned up yesterday. Unfortunately, I'm away til Sunday so couldn't make a start on it yet. I was wondering, however, whether I should hold my horses and fit some cap upgrades at the same time? I'm sure I've read that it'd be easier to do all this at once, rather than post-SB.
> 
> I also have a Blue Velvet pot sitting there which I'm going to fit. Quite exciting! Also, I can finally run that E80CC without worrying it's going to melt my Crack.


 
  
 Not sure if you have been following a few of us have had good results with this switching resistor mod
  
http://bottlehead.com/smf/index.php/topic,5989.0.html


----------



## Loquah

grrraymond said:


> My SB kit turned up yesterday. Unfortunately, I'm away til Sunday so couldn't make a start on it yet. I was wondering, however, whether I should hold my horses and fit some cap upgrades at the same time? I'm sure I've read that it'd be easier to do all this at once, rather than post-SB.
> 
> I also have a Blue Velvet pot sitting there which I'm going to fit. Quite exciting! Also, I can finally run that E80CC without worrying it's going to melt my Crack.


 
  
 It's all personal choice, but many people recommended that I should wait so I could hear the differences by doing one at a time. I'm glad I did so I can appreciate each part's own sound, but it's all a matter of preference.


----------



## skeptic

grrraymond said:


> My SB kit turned up yesterday. Unfortunately, I'm away til Sunday so couldn't make a start on it yet. I was wondering, however, whether I should hold my horses and fit some cap upgrades at the same time? I'm sure I've read that it'd be easier to do all this at once, rather than post-SB.
> 
> I also have a Blue Velvet pot sitting there which I'm going to fit. Quite exciting! Also, I can finally run that E80CC without worrying it's going to melt my Crack.


 
  
 Even if you don't throw in film caps at this point, I would go ahead and pull the old ones and reinstall them out to the sides on fly leads.  Those terminals are tough to access once the speedball is in place and the leads make it very easy to swap caps down the road.


----------



## Serenitty

skeptic said:


> Even if you don't throw in film caps at this point, I would go ahead and pull the old ones and reinstall them out to the sides on fly leads.  Those terminals are tough to access once the speedball is in place and the leads make it very easy to swap caps down the road.


 

 How long should the fly leads be?  I am planning on putting my speedball in this weekend and this is very useful advice...
  
 Thanks,


----------



## JamieMcC

After double stacking some film caps and adding the Triad choke to the Crack I needed a bit more ground clearance and had a bit of a idea to used some wood I had originally glued up to make some headphone stands from, luckily it was just long enough to make a enclosure out of. The wood enclosure is about 20mm deeper than the standard one.


----------



## MattTCG

jamiemcc said:


> After double stacking some film caps and adding the Triad choke to the Crack I needed a bit more ground clearance and had a bit of a idea to used some wood I had originally glued up to make some headphone stands from, luckily it was just long enough to make a enclosure out of. The wood enclosure is about 20mm deeper than the standard one.


 
  
 Dayum Jamie!! That's nice.


----------



## skeptic

serenitty said:


> How long should the fly leads be?  I am planning on putting my speedball in this weekend and this is very useful advice...
> 
> Thanks,




Happy to help! I think I used maybe 3.5 to 4 inch leads to start and then trimmed them down a bit when I actually installed my film caps. If you take a look at my default gallery, I know I have a pic in there somewhere of the stock output caps mounted on leads. Posting from my phone though so I can't easily dig up a direct link.


----------



## i luvmusic 2

Anybody know if  C3G tube can be use with Crack?


----------



## Keithpgdrb

Check the bottlehead forums crack page for a list of possi le tubes


----------



## i luvmusic 2

keithpgdrb said:


> Check the bottlehead forums crack page for a list of possi le tubes


 
 Thank You!


----------



## grrraymond

Thanks for the tips, gents. Always appreciated. I'm going to install it tomorrow and pop the caps out on fly leads. I'll have a proper read of that thread too, Jamie.


----------



## Keithpgdrb

Very informative things here.  i likely won't do all the mods.  I'd like to only really do the ones that will make the biggest impact on the sound.  It seems that changing the caps and adding the choke would be the easiest and most straight ahead.  the volume pot seems intimidating.
  
 Side note.  I use my crack with the hd600 and dt880.  does anyone else need to add the resistors to give more play in the volume control?  I can hardly move my volume with the 600's before its too loud.  But I'm not really hip with putting resistors in the signal path.  
  
 I'd like to be able to use the pot up to about 12:00, but there is no way in hell that is possible at this point.  can't really even get it to 9:00.


----------



## palmfish

The other problem is the Crack's channel imbalance is more obvious at low volume positions. Since my DAC has a pre-out volume control, I leave my Crack volume to about 50% and use the volume control on my DAC to adjust the volume. This makes the channel imbalance hardly noticeable.


----------



## Koolpep

palmfish said:


> The other problem is the Crack's channel imbalance is more obvious at low volume positions. Since my DAC has a pre-out volume control, I leave my Crack volume to about 50% and use the volume control on my DAC to adjust the volume. This makes the channel imbalance hardly noticeable.


 
  
 Hi!
  
 I do the same, it helps when your DAC take 24 bit signal as then volume control in your Mac/PC then still works. May I ask what causes the imbalance, since I experienced that as well and lowering the source volume helps but I like to tackle the cause, rather than the symptom (when I hopefully buy @punit Crack in a few days....). So is there any fix that a beginner can implement? A new poti/volume control maybe?
  
 Cheers,
 K


----------



## ben_r_

palmfish said:


> The other problem is the Crack's channel imbalance is more obvious at low volume positions. Since my DAC has a pre-out volume control, I leave my Crack volume to about 50% and use the volume control on my DAC to adjust the volume. This makes the channel imbalance hardly noticeable.


 

 That is cool if you can do that. I use an UberFrost though, so it is what it is.


----------



## Keithpgdrb

palmfish said:


> The other problem is the Crack's channel imbalance is more obvious at low volume positions. Since my DAC has a pre-out volume control, I leave my Crack volume to about 50% and use the volume control on my DAC to adjust the volume. This makes the channel imbalance hardly noticeable.


 
 I have done that to a point, but my dac/pre sounds best between 12 and 3.  so I don't want to move it much lower then that.


----------



## Shaldome

Finally managed to finish my Speed Ball Upgrade today. After some delay because I lost some of the resistors (twice!) I finally got to continue building it yesterday and finished it today.
 Disregarding the interruptions, because of the lost parts, everything went quite smooth.
 I only had some incidents which were not as planned.
  
 As I resoldered some of the my former work I thought I might as well clip some of the wires which I had forgotten the last time. I was wondering why i had that much wire at one point of the transformer and proceeded to cut it through. Well, turned out it was not my wiring at all but part of the transformer. Fortunately it was fastened on both ends and I just cut it through. I "fixed" it by soldering it back together again.
 Second one was caused by brain lag on my side. If Doc writes in the manual "DO NOT remove the nuts before you do this" in the step of screwing the standoffs on the board e actually means that you should not remove the nuts. I somehow interpreted this as "do not remove up until this step". If you like dexterity based games, you can do it the same way as I did and remove the nuts and then try to screw them back on, as you already installed the smaller boards.
 Which leads to my last error, which I only found out about after I powered the Crack on after finishing everything and wondered, why the LEDs on the right smaller board did not light up. Turned out that I soldered the wire meant for point I to a point with a dash which from the side looked like an I.
  
 So all in all only minor problems and the Crack sound even better now.
  
 Let's see if my other project for a pupDAC goes as smooth as the Crack build. I somehow doubt it.


----------



## palmfish

koolpep said:


> Hi!
> 
> I do the same, it helps when your DAC take 24 bit signal as then volume control in your Mac/PC then still works. May I ask what causes the imbalance, since I experienced that as well and lowering the source volume helps but I like to tackle the cause, rather than the symptom (when I hopefully buy @punit Crack in a few days....). So is there any fix that a beginner can implement? A new poti/volume control maybe?
> 
> ...




I suspect its the potentiometer but it could also be the tubes. I just think point to point is more prone to imbalance than SS (opamps) because there is simply more margin for error. It's very subtle and I usually dont notice it with the Crack Pot (pun intended) turned up a ways.



ben_r_ said:


> That is cool if you can do that. I use an UberFrost though, so it is what it is.




The pre-out is one of several reasons why I am so fond of the Essence One Muses. It just does so many things so well. Ive heard good things about the UberFrost too and there are other ways to increase the play in the volume control (as discussed here and in the Bottlehead Forums). You have a nice setup and I wouldnt change a thing if I were in your shoes.




keithpgdrb said:


> I have done that to a point, but my dac/pre sounds best between 12 and 3.  so I don't want to move it much lower then that.




The position of the volume control shouldnt change the sound, it should simply change the volume. I think maybe something else is going on in your chain.


----------



## Loquah

keithpgdrb said:


> Very informative things here.  i likely won't do all the mods.  I'd like to only really do the ones that will make the biggest impact on the sound.  It seems that changing the caps and adding the choke would be the easiest and most straight ahead.  the volume pot seems intimidating.
> 
> Side note.  I use my crack with the hd600 and dt880.  does anyone else need to add the resistors to give more play in the volume control?  I can hardly move my volume with the 600's before its too loud.  But I'm not really hip with putting resistors in the signal path.
> 
> I'd like to be able to use the pot up to about 12:00, but there is no way in hell that is possible at this point.  can't really even get it to 9:00.


 
  
 So long as you buy a preassembled attenuator (search eBay for Dale attenuator 100K), the swap is pretty easy. You just need to swap the wires from the existing pot to the new attenuator and you might have to enlarge the locking hole in the chassis plate, but you can't see it once assembled so the job doesn't have to look perfect. Other than adding the Speedball (and possibly choke), the attenuator is the next most significant upgrade - more so than caps because the existing pot will actually mask some of the improvements brought by caps.


----------



## Keithpgdrb

Ah. So the choke and the pot should be the next step, as I already have the speedball in.


----------



## Loquah

I would say so based on my experiences. Caps are a nice upgrade, but they are subtle like tubes versus the volume pot which is a clear and significant upgrade and makes all other upgrades more impactful because you're removing a potential bottle-neck from your Bottlehead. (See what I did there? 
	

	
	
		
		

		
			





)


----------



## Serenitty

Got my speedball installed today. It would have been pretty quick but I put the heatsink and transistors on the wrong side of the big board and then played merry hell getting them unsolder end and removed to out them on the right side of the board. After that the only issue was space.. My bent metal copper crack has a small interference issue with the volume pot and the right ride small speedball board. I rotated the board about 5 degrees and bent one of the vol pot leads out of the way. The correct solution will have to be a much longer standoff. Thankfully the copper crack design is taller and has lots of space. 

I'm also getting a spike over 20v on startup at the headphone jack, the final test. At least I think I am, the auto ranging multimeter changes scale up and down so quickly I'm not sure. I'm going to have to video the multimeter and play it back slow to be sure. All the other tests are inspec. 

Sounds great though.


----------



## Loquah

serenitty said:


> Got my speedball installed today. It would have been pretty quick but I put the heatsink and transistors on the wrong side of the big board and then played merry hell getting them unsolder end and removed to out them on the right side of the board. After that the only issue was space.. My bent metal copper crack has a small interference issue with the volume pot and the right ride small speedball board. I rotated the board about 5 degrees and bent one of the vol pot leads out of the way. The correct solution will have to be a much longer standoff. Thankfully the copper crack design is taller and has lots of space.
> 
> I'm also getting a spike over 20v on startup at the headphone jack, the final test. At least I think I am, the auto ranging multimeter changes scale up and down so quickly I'm not sure. I'm going to have to video the multimeter and play it back slow to be sure. All the other tests are inspec.
> 
> Sounds great though.


 
  
 From memory there's a mod posted as a sticky at the top of the Crack threads on the Bottlehead forum to help deal with the voltage spike on the HP jack.


----------



## Serenitty

loquah said:


> From memory there's a mod posted as a sticky at the top of the Crack threads on the Bottlehead forum to help deal with the voltage spike on the HP jack.




Yes, I just read about that on the bottlehead forum. I may try that tomorrow. For now I just wait 15-20 seconds before plugging my headphones in. 

Thanks


----------



## Loquah

serenitty said:


> Yes, I just read about that on the bottlehead forum. I may try that tomorrow. For now I just wait 15-20 seconds before plugging my headphones in.
> 
> Thanks


 
  
 Cool. That works too!


----------



## Keithpgdrb

serenitty said:


> Yes, I just read about that on the bottlehead forum. I may try that tomorrow. For now I just wait 15-20 seconds before plugging my headphones in.
> 
> Thanks


 
 yeah, there are about 2-3 fixes posted on the site.  make sure your aware of them all.


----------



## Keithpgdrb

whats a decent price for the Dale attenuator 100K


----------



## Loquah

keithpgdrb said:


> whats a decent price for the Dale attenuator 100K


 
  
 I paid about $50 US for mine (assembled)


----------



## radiojam

Does anyone have experience with how well a Bottlehead Crack sits on top of a Bifrost?  It's a little difficult getting the exact dimensions of the Crack but from my research it looks +/- 10.5" x 6.5"?  The Bifrost is 9" x 6.75" (ignoring height) so it sounds like it could be doable.


----------



## punit

loquah said:


> I would say so based on my experiences. Caps are a nice upgrade, but they are subtle like tubes versus the volume pot which is a clear and significant upgrade and makes all other upgrades more impactful because you're removing a potential bottle-neck from your Bottlehead. (See what I did there?
> 
> 
> 
> ...


 
 You have a Cracked sense of humor


----------



## Loquah

punit said:


> You have a Cracked sense of humor


 
  
 Awww, go on, it was just a Quickie!


----------



## punit

loquah said:


> Awww, go on, it was just a Quickie!


 
  
 OMG! these childish jokes make me want to Mainline


----------



## Koolpep

punit said:


> OMG! these childish jokes make me want to Mainline


 
  
 Oh man, all this talk makes me think about S.E.X. the whole time


----------



## MoatsArt

Punit is an apt name


----------



## punit

koolpep said:


> Oh man, all this talk makes me think about S.E.X. the whole time


 

 Hmmm. you can either hit the BOTTLE or alternatively can get some HEAD.


----------



## punit

Or you can get hit on the HEAD by a BOTTLE :
  
 http://gawker.com/watch-justin-bieber-get-hit-by-a-water-bottle-1457818249
  
 this ones my fav


----------



## Koolpep

OMG
  
 Now you make me read about Justin Bieber 
	

	
	
		
		

		
		
	


	




 - and the worst thing is, I read it. All of it. *facepalm*


----------



## ben_r_

keithpgdrb said:


> whats a decent price for the Dale attenuator 100K


 

 Believe I have seen them on ebay for around $26.


----------



## grrraymond

I fitted the Blue Velvet pot yesterday and I can appreciate there is some difference. It's definitely silent and smooth, perfectly balanced at low volumes. I suppose it's worth it for the smoother action but while it does affect the performance, I don't think it affects the sound quality, if you know what I mean.
  
 Still waiting to put my SB in, I got a mispack unfortunately but hoping my replacement resistors will be here tomorrow and I can get the job finished. It's worth opening up the Crack, though, as I rewired and resoldered a few joints which looked a bit dodgy/ugly and it helped me get into the swing of things for the PCB SB soldering. After reading that there's arguably no difference with oil caps, I'm now tempted to just skip them and leave my modding days behind after the Speedball.
  
 Looking forward to quoting that back to myself in a few months' time.


----------



## mcandmar

keithpgdrb said:


> whats a decent price for the Dale attenuator 100K


 
  
 I can recommend this seller,
  
http://www.ebay.com/itm/Assembled-Dale-23-Step-Attenuator-Volume-Control-100k-/270311271326?pt=US_Amplifier_Parts_Components&hash=item3eefceab9e
  
 Or the kit version if your a sucker for punishment,
  
http://www.ebay.com/itm/DIY-kit-Dale-23-Step-Attenuator-for-Volume-Control-100k-/280321499342?pt=US_Amplifier_Parts_Components&hash=item414476a0ce


----------



## ben_r_

What about this one: LINK
  
 Looks like it might be using 1% resistors.


----------



## HPiper

On the headphone section of the forum they have a topic called something like Grado Mods, where they pulled together all the various mods people have done and found work on the Grado headphones. Too bad we couldn't do something like that for the Crack amp. List the mod, the parts, where to get the parts, pictures of how to do the mod, all that. It would be helpful for people wanting to upgrade their amp. Let them maybe have some of the parts on hand as they build it so they could upgrade as they build in some cases.


----------



## Keithpgdrb

ben_r_ said:


> What about this one: LINK
> 
> Looks like it might be using 1% resistors.


 
 looks good to me.  anyone else?


----------



## Doc B.

hpiper said:


> Let them maybe have some of the parts on hand as they build it so they could upgrade as they build in some cases.


 
 Great idea. We will give them your email address for tech support.


----------



## HPiper

doc b. said:


> Great idea. We will give them your email address for tech support.


 

 Do the people who are currently modding their kits call you for tech support? People adding all kinds of capacitors and different resistors that weren't in the original design call Bottlehead? Wouldn't really surprise me but I don't understand your comment. All the information is already out there it is just scattered all over the place. Maybe put a disclaimer in the documentation in BIG letters, "We do not offer tech support on any non-kit parts, or components." Actually that seems like a good idea to me.


----------



## .Sup

doc b. said:


> Great idea. We will give them your email address for tech support.



All you have to do is make a forum, state that you don't offer any support for various mods and let kind people at Bottlehead forum be helpful as they always are. I see no harm in that.


----------



## ben_r_

doc b. said:


> Great idea. We will give them your email address for tech support.


 
  
 Quote:


.sup said:


> All you have to do is make a forum, state that you don't offer any support for various mods and let kind people at Bottlehead forum be helpful as they always are. I see no harm in that.


 

 Bottlehead already has a thriving forum where they talk about all kinds of things including upgrades and mods. But Ill admit that comment was a bit odd and I couldnt figure it out either.


----------



## atomicbob

If you have ever provided tech support to anyone that is unreasonable in their expectations or whose skill set preclude being successful in such activities, you will know from where Doc's comment arises. I am positive that Doc has had many such opportunities. Most folks are reasonable, but as a business entity Doc doesn't get to choose his customers.


----------



## spacequeen7

will there be any harm in swapping 100 uF output caps with 70 uF ??


----------



## JamieMcC

I ran mine with 47uf for a while and I know of one that runs 60uf pio. What type are you thinking of trying?


----------



## Doc B.

We are one of the few businesses that supports the notion of mods to our products. And yes, people call all the time, PM me at two different forums, and email with mod questions at a couple of different emails. That's great, we have created what we like to think of as a community that isn't scared to get inside stuff and find out what makes it tick. And the idea of a place that contains some organized documentation on mods is a fine idea too.
  
 Please forgive the apparent impatience of my previous post. The reason for my response is the suggestion that people do an initial build of a kit with "upgrade" parts. Because of the volume of kits we sell and support we maintain the recommendation that our kits should be built as designed before being modified. That way we can effectively support the user if they have issues with their construction. Once it's up and running doing mods is great because it's a lot easier to sort if the mod doesn't work out. But if one has never soldered before and/or does not have enough experience to figure out the potential kinks created by performing a mod on their own it can save a lot of headache to build the kit stock and be sure it works before changing stuff. The skills that you acquire with the initial build will make future installation of your favorite mod go that much easier.


----------



## MoatsArt

spacequeen7 said:


> will there be any harm in swapping 100 uF output caps with 70 uF ??




There is a relationship between the value of this capacitor and the bass roll off frequency. The lower the capacitor value the higher this frequency will be (within the limits of your hearing). I think that the impedance of your headphones also comes into play. I don't know the formula, but there is a calculator somewhere that works it out. A value of 100uF was chosen to produce a bass roll off at about 20 Hz I think.


----------



## JamieMcC

There are some handy calculators on the v-cap site http://www.v-cap.com/tech.php there was also a chart posted on the old bh forum I'm not sure if it made the transition to the new site or was corrupted.


----------



## Loquah

doc b. said:


> We are one of the few businesses that supports the notion of mods to our products. And yes, people call all the time, PM me at two different forums, and email with mod questions at a couple of different emails. That's great, we have created what we like to think of as a community that isn't scared to get inside stuff and find out what makes it tick. And the idea of a place that contains some organized documentation on mods is a fine idea too.
> 
> Please forgive the apparent impatience of my previous post. The reason for my response is the suggestion that people do an initial build of a kit with "upgrade" parts. Because of the volume of kits we sell and support we maintain the recommendation that our kits should be built as designed before being modified. That way we can effectively support the user if they have issues with their construction. Once it's up and running doing mods is great because it's a lot easier to sort if the mod doesn't work out. But if one has never soldered before and/or does not have enough experience to figure out the potential kinks created by performing a mod on their own it can save a lot of headache to build the kit stock and be sure it works before changing stuff. The skills that you acquire with the initial build will make future installation of your favorite mod go that much easier.


 
  
 Having started with the Crack and then working my way through the S.E.X. and the Mainline, I have to strongly endorse the idea of starting with the stock kit and then adding on later. Partly because it allows easier trouble-shooting, but also because I'm finding that I'm learning more now about the kits and the components from trying to decide what to modify and with which components. If I had been handed a package with all the pieces including modifications I never would have learned what I am now starting to understand. It's fine to build the kit by "joining the dots" because it would be too much to have to work it all out the first time, but starting with a known, working system allows for lots of fun and learning as you then research and upgrade to meet your specific needs.


----------



## MoatsArt

Thanks Jamie. Very handy.


----------



## audiowize

There are also a lot of expensive aftermarket parts that sound absolutely terrible.  You can actually make a kit build a whole lot worse by spending a lot of money on boutique parts.


----------



## atomicbob

audiowize said:


> There are also a lot of expensive aftermarket parts that sound absolutely terrible.  You can actually make a kit build a whole lot worse by spending a lot of money on boutique parts.


 
 Amen! Doc's stock Crack has a really good sound. Roll a couple of tubes, install the SpeedBall, possibly put a 0.01uF 250V film cap across the third electrolytic in the power supply. At this point it is way ahead of most tube amps out there.


----------



## snapple10

my curiosity got the best of me, had to try the crack with Senn 6xx
  
 got a question though, can I use the USAF 596 with the crack? do I need an adapter? thanks in advance


----------



## atomicbob

snapple10 said:


> my curiosity got the best of me, had to try the crack with Senn 6xx
> 
> got a question though, can I use the USAF 596 with the crack? do I need an adapter? thanks in advance


 
 NO!  Not without major modifications, including adding another tube socket and modifying the power supply. The USAF 596 is a rectifier tube. Crack uses semiconductor diodes for this function in the power supply. The 6AS7 / 6080 used by the Crack is a power triode for signal amplification.


----------



## snapple10

Thanks!
So much goes behind building amps/daps/DACs . I will stick to enjoying them 
Glad there is always somebody to answer my questions


----------



## lost&confused

Do any of you have a problem with noise when the speedballs installed and 5998  tubes with volume right down ...volume at 0% ....
 The 1st 5mm of volume travel  noise then  its ok after that ...dead silent.
  
 I've had 4 5998 tubes now and all of them make a buzzing noise with the volume turned right down.
  
 One of the tubes I had made the noise at all volumes so i sent it back, but now ive tried 3 more and all these tubes have the noise but only when volumes at 0%.
 One of my new tubes the noise goes away after 30 mins tho.
  
 I removed the speedball when I had the really noisy tube and it was perfect then . 
 I have this same noise with other types of tubes but it always goes away. (Mullard 6080 perfect, noise for 3 seconds max,  RCA takes a bit longer , 2 RCA 6AS7G tubes takes a few mins.
  
 A few other people are experiencing this on the bottlehead forums.
  
 EDIT:  This problem has been fixed......The noise at 0%  Volume was a faulty batch of MJE350's Transistors .


----------



## dsound

lost&confused said:


> Do any of you have a problem with noise when the speedballs installed and 5998  tubes with volume right down ...volume at 0% ....


 
  
 Sorry you're experiencing issues.  I have Chatham 2399 (5998 variant) and haven't experienced this with my amplifier.  At one point I did have an issue with another tube (buzzing) that was alleviated with some Deoxit.


----------



## grrraymond

Yup, I've got the exact same issue with my freshly-installed SB. It seems common enough for me not to worry about it, although I did crap myself at first, especially when accompanied by a single pop! It's all settled down now, good as gold. 

My thoughts on the Speedball: Significantly faster, the upper mids and treble really snap and sizzle now, it's so lively. The soundstage and separation is noticeably better, I'm picking out even more details because the placement of instruments is more pronounced. Bass is cleaner and more taut but a little deeper. Listening to the Aphex Twin remix of 808 State - Flow Coma and that acid bassline is so rubbery and tight. There's just a vast amount of spatial detail on every element of the mix, insane. This isn't music you'd expect the HD650s to do particularly well because it's begging for quick phones but this is sick. Moving onto Earth, Wind & Fire - In The Stone (from 'I Am', one of my top reference records, an brilliant music, to boot). This is the sound of the HD650s in their comfort zone and absolutely soaring. The richness of the horns, synths and keys is amazing, the layered male vox are fantastic and the rhythm section sounds more alive than ever.

OK, gotta go listen.

Edit: Ugh...Weather Report sounds so damn good. So rich and colourful, that riff in Birdland is just like nothing I've heard before. This is really something. Ugh. Wish I could book tomorrow off work.

Edit 2: Animal Collective's Merriweather Post Pavilion is one of my favourite records of all time but I've always thought the production was so dense, it's almost a fault. No more. You can hear every layer of the harmonies, every burble and bleep and whoosh, the bass is tight and neat but it absolutely bumps. Best purchase I've made since the Crack itself. I was dubious, to be honest, but it really really is worth it.


----------



## lost&confused

Thanks for the input guys...The noise is so annoying with the 5998 tubes I have tho.
 With my other tubes all is fine tubes are warmed up noise goes away but I don't like the other tubes with the speedball 
  
 I use HD600's and with the speedball I found the sound changed..More detail but its brighter and not as much bass i think,  the 5998 tubes takes the brightness away some what and brings the bass back.
  
 I'm Still undecided whether I like the speedball with the HD600's  , I can see why people would like the speedball with  650s tho  .....should never of sold my hd650s now


----------



## NightFlight

punit said:


> Funny thing is , I go to a lot of concerts  (been to Texas, Santana, Lionel Richie this month, Pet Shop Boys & Fat Boy Slim next week.....) & some times the sound set up is not that great & I actually go "Hmm... sounds better on my Headphones"
> 
> 
> 
> ...


 
  
 Sometimes? Sometimes? Ugh. Most venue's are simply TERRIBLE.  Booze helps. A-lot.


----------



## Tequilasunriser

No kidding. The last few shows I've been to sounded down-right terrible. It's like the loudness wars are creeping into the live theater now too.


----------



## spacequeen7

jamiemcc said:


> I ran mine with 47uf for a while and I know of one that runs 60uf pio. What type are you thinking of trying?


 
 70 uF Obbligato Oil ,I  just don't want to loose bass ,I already have them and I'm pretty sure they will fit  with small HS "modification"


----------



## mordicai

Yah, same problem. Only discovered it recently as I never turn the volume knob that far. SB,5998,hd 600's. Just the last few millimeters and a LOUD hum! Wonder what it is. Got some insight for us Doc?


----------



## Loquah

grrraymond said:


> Yup, I've got the exact same issue with my freshly-installed SB. It seems common enough for me not to worry about it, although I did crap myself at first, especially when accompanied by a single pop! It's all settled down now, good as gold.
> 
> My thoughts on the Speedball: Significantly faster, the upper mids and treble really snap and sizzle now, it's so lively. The soundstage and separation is noticeably better, I'm picking out even more details because the placement of instruments is more pronounced. Bass is cleaner and more taut but a little deeper. Listening to the Aphex Twin remix of 808 State - Flow Coma and that acid bassline is so rubbery and tight. There's just a vast amount of spatial detail on every element of the mix, insane. This isn't music you'd expect the HD650s to do particularly well because it's begging for quick phones but this is sick. Moving onto Earth, Wind & Fire - In The Stone (from 'I Am', one of my top reference records, an brilliant music, to boot). This is the sound of the HD650s in their comfort zone and absolutely soaring. The richness of the horns, synths and keys is amazing, the layered male vox are fantastic and the rhythm section sounds more alive than ever.
> 
> ...


 
  
 Weather Report's mastering and production was SO good!!! Birdland is still one of my all time favourites.


----------



## MoatsArt

Dah..... Dah......Dah..............
Dah......Dit ....de Dah............

Gets me feet tapping and head bobbing every time.


----------



## MoatsArt

A parcel arrived from Bottlehead today, including two Cacks. Can't wait to start building the first.


----------



## Loquah

moatsart said:


> A parcel arrived from Bottlehead today, including two Cacks. Can't wait to start building the first.


 
  
 2 Cracks? What do you have planned??


----------



## grrraymond

moatsart said:


> A parcel arrived from Bottlehead today, including two Cacks.


 
  
 That seems harsh.


----------



## lost&confused

I've just swapped my headphone cable to a thicker HD650 cable on my old pair of HD600's (my old HD600 cable was so thin) and the brightness has completely gone! ... much better now   amazing what a cable can do.


----------



## MoatsArt

loquah said:


> 2 Cracks? What do you have planned??




Firstly, I will be building a stock Crack without Speedball.

Once I have reacquainted myself with its sound I will be building a second Crack that I will be gradually modding and tweaking, at each stage comparing it to the bog standard Crack. The name of this first Crack build will be "Pure Crack". The name of the modded Crack will be "Crack of Dawn Mk II".

At the same stage as modding this second Crack I will be working on an experimental third with some more serious and fundamental mods.


----------



## Koolpep

moatsart said:


> Firstly, I will be building a stock Crack without Speedball.
> 
> Once I have reacquainted myself with its sound I will be building a second Crack that I will be gradually modding and tweaking, at each stage comparing it to the bog standard Crack. The name of this first Crack build will be "Pure Crack". The name of the modded Crack will be "Crack of Dawn Mk II".
> 
> At the same stage as modding this second Crack I will be working on an experimental third with some more serious and fundamental mods.


 
  
 Wow, very interesting project, please keep us updated.


----------



## punit

moatsart said:


> Firstly, I will be building a stock Crack without Speedball.
> 
> Once I have reacquainted myself with its sound I will be building a second Crack that I will be gradually modding and tweaking, at each stage comparing it to the bog standard Crack. The name of this first Crack build will be "Pure Crack". The name of the modded Crack will be "Crack of Dawn Mk II".
> 
> At the same stage as modding this second Crack I will be working on an experimental third with some more serious and fundamental mods.


 

 Nice, so you are building a Crack, Cracker & Crakest.


----------



## mcandmar

moatsart said:


> Firstly, I will be building a stock Crack without Speedball.
> 
> Once I have reacquainted myself with its sound I will be building a second Crack that I will be gradually modding and tweaking, at each stage comparing it to the bog standard Crack. The name of this first Crack build will be "Pure Crack". The name of the modded Crack will be "Crack of Dawn Mk II".
> 
> At the same stage as modding this second Crack I will be working on an experimental third with some more serious and fundamental mods.


 
  
 But what if you build them both stock and they sound different


----------



## MoatsArt

Yep - The superlative of Crackendom. 

An odd project, but hopefully an instructive and entertaining one.

You will have heard of "Dumb & Dumber". I am the Dumberest.


----------



## MoatsArt

mcandmar said:


> But what if you build them both stock and they sound different




That happens all the time in our hobby, and not just by amateurs. It's called lack of quality control.


----------



## JamieMcC

Nathan I'm looking forward to hearing more on your build progress it sounds like a interesting and fun project.


----------



## Serenitty

mcandmar said:


> But what if you build them both stock and they sound different


 

 I would think being tube amps you could almost expect this if there are differences in the tubes that ship with the kits.  I would think you could build two kits perfectly and still have them sound different.  I think Doc called it a "tube lottery" somewhere on their site.


----------



## Doc B.

mordicai said:


> Yah, same problem. Only discovered it recently as I never turn the volume knob that far. SB,5998,hd 600's. Just the last few millimeters and a LOUD hum! Wonder what it is. Got some insight for us Doc?


 
 Yes. We have spent a few days working the problem. It appears that in the last batch of MJE350 transistors we purchased from a new vendor there are some random samples that are not up to spec. We have a new batch on order from one of our most reliable suppliers and when we get them in anyone who has purchased a Speedball in the past couple of months and is experiencing this issue can contact us for a replacement pair of MJE350s. The email to contact is replacementparts at bottlehead dot com.


----------



## mordicai

Thanks Doc, I thought I had screwed up but everything looked o.k. Not many products sold today that come with this level of support. You guys are a company from a different age.


----------



## JamieMcC

Good to hear you guys have nailed down the issue, superb builder support.
  
 As we haven't had one for a while and I need some practice.
  
 I am sure watching the tubes glow makes it sound even better!


----------



## Doc B.

Thanks for the kind words. We know that most of our customers are DIY newbs and thus their worry factor is a little on the high side. And so we do our best to deal with all concerns.
  
 After you blow up a few things DIY gets a lot easier.


----------



## Loquah

Nathan, looking forward eagerly to following your Crack odyssey (Crackyssey?)

Doc, that's so true. I started as a newb who could solder, but had no clue of what bits did what. With some magic smoke under my belt, as it were, I'm now modifying stuff and really starting to understand the basics of what does what. Couldn't have done this without the wonderful support of your products and manuals and the awesome communities here and on the Bottlehead forum.


----------



## JamieMcC

loquah said:


> Nathan, looking forward eagerly to following your Crack odyssey (Crackyssey?)
> 
> Doc, that's so true. I started as a newb who could solder, but had no clue of what bits did what. With some magic smoke under my belt, as it were, I'm now modifying stuff and really starting to understand the basics of what does what. Couldn't have done this without the wonderful support of your products and manuals and the awesome communities here and on the Bottlehead forum.


 

 +1


----------



## mcandmar

loquah said:


> Nathan, looking forward eagerly to following your Crack odyssey (Crackyssey?)
> 
> Doc, that's so true. I started as a newb who could solder, but had no clue of what bits did what. With some magic smoke under my belt, as it were, I'm now modifying stuff and really starting to understand the basics of what does what. Couldn't have done this without the wonderful support of your products and manuals and the awesome communities here and on the Bottlehead forum.


 
  
 +2 I knew nothing about valve amps six months ago, thanks for the new hobby!


----------



## mordicai

The only thing Ive learned on the site is that I don't know squat!


----------



## Loquah

That's a great place to start!


----------



## mullardpassion

Hello crackheads..For those using the 5998, what are your fav input tubes?


----------



## MoatsArt

Pure Crack is up and running. Late night tonight, fellas.


----------



## grrraymond

mullardpassion said:


> Hello crackheads..For those using the 5998, what are your fav input tubes?


 
  
 I've settled on the E80CC with my Speedballed Crack. It's a Brimar, though I don't know whether it's a rebrand or what have you.
  
 With the stock Crack it was considerably bolder than my other options, including second favourite Mullard ECC82. Bass had more substance and meat to it, the soundstage opened up, speed, detail and separation were all better. Most of all, it just felt more visceral and ecstatic, very tubey but not muddy at all. Unfortunately, the stock Crack is not designed to run it so I rolled my ECC82 back in.
  
 With the Speedball installed, I have realised that there's not as much difference between tubes but the E80CC is still the best for me. Fast but full, rich and panoramic. Apparently, with a semi-permanent resistor mod (will negatively affect the running of other tube pairings), you can get even more from the E80CC & 5998 combo. I'm just waiting for the resistors to arrive. No doubt in my mind.
  
 N.B. Some bright sparks on the BH forum have come up with a switch-based mod to allow you to also revert to the previous resistances to run any variety of 12AU7 and 6080 etc without compromise. Personally, I've reached a sound I definitively and exclusively prefer so I'm going to push on down the semi-permanent road, in any case.


----------



## mullardpassion

Thanks..The Mullard ecc82 and the RCA5814A have been my favourite tubes so far. I think the best way to mod the crack, is to upgrade each part at a time, and to know exactly how it alters the sound. The speedball is the single best upgrade to go for. I might try the e80cc afterwards


----------



## punit

moatsart said:


> Pure Crack is up and running. Late night tonight, fellas.


 

 wow.. that was a fast build.


----------



## MoatsArt

The Pure Crack



No upgrades (except tubes - Running a Tung Sol 7236 & Tung Sol 12AU7 black glass black plate). Base coated with tung oil and finished with wax.

Great to be able to get out my T1s again.


----------



## atomicbob

moatsart said:


> The Pure Crack
> 
> 
> 
> ...


 
 That was fast! Great looking build. T1s should sound excellent on your Pure Crack.


----------



## lost&confused

My fav tube combo so far with the Crack/Speedball is the Mullard CV491 / 12AU7 K61 with the a Tung Sol 5998,
 I just tried a Holland Phillips Miniwatt ECC82 and that sounds nice but its bad tube   has a Shhhh crackle sound so its rubbish.
 I also have some Telefunken E80cc tubes to try but I'm still waiting for the resistors to show up.
  
 Changing my rca interconnect cables from a pair of "Cable Talks" copper  to a  pair of  silver RCA cables made a nice change.


----------



## dsound

mullardpassion said:


> Hello crackheads..For those using the 5998, what are your fav input tubes?


 
 I'm a big fan of the RCA 12au7 black plate.  To me, it gives a nice bloom to the bass while still being detailed.  And they're cheap!


----------



## grrraymond

I should say I also really enjoyed the CV4003 but it died on me after a few weeks, and scared the **** out of me in the process.
  
 Just finished the E80CC resistor mod and surprised at the improvements. I guess it just powers the tube as it's designed to, so I shouldn't be surprised. It's well worth doing. Mids definitely opened up.
  
 Edit: Holy balls. Just listened to Death Grips - No Love and physically recoiled when that enormous reverbed kick came in. Crumbs! Monstrous.


----------



## JamieMcC

Its such a simple and inexpensive mod perhaps deserved of a place on the BH Crack sticky list so others can benefit without having to re ask the question or rely on searching through the forum.


----------



## FlySweep

For those who have done the resistor mod/switch to 'optimize' the SB'ed Crack's circuit for the E80CC/12BH7.. have you noticed any change in the 12BH7/E80CC's tube's presentation in the optimized (12BH7) circuit vs the stock (12AU7) circuit?
  
In the stock circuit, I find 12BH7s/E80CCs to generally have a more forward presentation and possessing a more intimate (in terms of width) but larger (more depth and height) soundstage... relative to most of my 12AU7s).


----------



## i luvmusic 2

What do you guys think about using 6SN7 on the Crack or have you guys used it before?


----------



## .Sup

grrraymond said:


> I should say I also really enjoyed the CV4003 but it died on me after a few weeks, and scared the **** out of me in the process.




lol what happened, did it make a loud pop?


----------



## grrraymond

jamiemcc said:


> Its such a simple and inexpensive mod perhaps deserved of a place on the BH Crack sticky list so others can benefit without having to re ask the question or rely on searching through the forum.


 
  
 Totally agree and I wouldn't have known about it but for your post on here, Jamie. So, again, many thanks.


----------



## grrraymond

.sup said:


> lol what happened, did it make a loud pop?


 
  
 SSSSCCCCRRRRRRAAAAAAAWWWWKKKKKKKKKKKKK x 1000


----------



## olegausany

i luvmusic 2 said:


> What do you guys think about using 6SN7 on the Crack or have you guys used it before?



I have tried Kenrad 6SN7 with stock Crack with Speedball and heard nothing special to write home about but will try with moded one some time next week


----------



## i luvmusic 2

olegausany said:


> I have tried Kenrad 6SN7 with stock Crack with Speedball and heard nothing special to write home about but will try with moded one some time next week


 
 Thank You!These are the tubes that i have for now and 6AS7 few 12AU7 and a bit of 7 pin tubes that i want to try with the CRACK as soon as a get it.


----------



## grrraymond

flysweep said:


> For those who have done the resistor mod/switch to 'optimize' the SB'ed Crack's circuit for the E80CC/12BH7.. have you noticed any change in the 12BH7/E80CC's tube's presentation in the optimized (12BH7) circuit vs the stock (12AU7) circuit?
> 
> In the stock circuit, I find 12BH7s/E80CCs to generally have a more forward presentation and possessing a more intimate (in terms of width) but larger (more depth and height) soundstage... relative to most of my 12AU7s).


 
  
 Although I haven't fitted a switch, I do know what you mean. With the resistor mod, I'm finding it to be more 'refined'. That may sound like a backhanded compliment but it's peeled back layers in some of my favourite music which I'd never heard before. It seems to perform miracles on the mids. While I really enjoyed the upfront tubey thrills of the E80CC, and probably most of all in the stock Crack in fact, I'm blown away by what it is capable of, when run properly.


----------



## Armaegis

doc b. said:


> After you blow up a few things DIY gets a lot easier.


 
  
 Or you learn to blow things up better


----------



## MoatsArt

I tried blowing up a bus once, but I burnt my lips on the exhaust pipe.


----------



## Armaegis

That's what you get going for sloppy seconds...


----------



## olegausany

Got Matt's Crack and it sounds great driving HD800 using Philips E80CC and Tungsol 5998


----------



## RonO

It's been over 2 years, but those looking to build the Crack kit, well, here  you go.. condensed down to under 8 minutes:
  
 https://www.youtube.com/watch?v=lkU2ECc_VUs
  
 The video failed to show the finished build, so here is a current shot of the amp at the recent Atlanta meetup: 

  
 Enjoy.
  
 RonO


----------



## Aeolus Kratos

rono said:


> It's been over 2 years, but those looking to build the Crack kit, well, here  you go.. condensed down to under 8 minutes:


 
  
 Why didn't you use the Quickie with the Crack, RonO?


----------



## RonO

We did. Putting the Quickie in front of the Crack results in totally insane sound, incredible bass.  A Quickie build is on my short list. I can't quite fully explain it, but putting the Quickie in front of the Crack, listening with my HD-600's was just awesome.  I also got to hear it on MattTCG's modded Crack with his 650's.  Same experience, mind blowing.


----------



## radiojam

rono said:


> It's been over 2 years, but those looking to build the Crack kit, well, here  you go.. condensed down to under 8 minutes:
> 
> https://www.youtube.com/watch?v=lkU2ECc_VUs
> 
> ...


 
  
 Cool!  Are you experienced with DIY? how long did it take?


----------



## MattTCG

rono said:


> We did. Putting the Quickie in front of the Crack results in totally insane sound, incredible bass.  A Quickie build is on my short list. I can't quite fully explain it, but putting the Quickie in front of the Crack, listening with my HD-600's was just awesome.  I also got to hear it on MattTCG's modded Crack with his 650's.  Same experience, mind blowing.


 
  
 I was there...I heard it...my mind was blown.


----------



## FlySweep

Sorry for going OT here.. but I'd be interested in hearing how the Quickie sounded in front of the Mjolnir.. sounds like a good match, there.


----------



## MattTCG

I posted a thread on the bottlehead forum asking that question...no one has responded.


----------



## MattTCG

I've experimented with the lyr this weekend and the quickie acting as pre. It does not have the same effect when paired with the crack.


----------



## olegausany

matttcg said:


> I've experimented with the lyr this weekend and the quickie acting as pre. It does not have the same effect when paired with the crack.



You mean it pairs great with Crack but not with Lyr?


----------



## spacequeen7

what is the aluminium plate measurement on quickie guys , same size as the Crack's plate ?


----------



## Loquah

It's smaller I think and made of (random) coloured perspex. There are some more details on the BH website including some case options from Hammond which are the exact same size so you can use those as a reference if no-one has the answer.


----------



## FlySweep

I've been rocking a Sylvania 12BH7 (w/ (curved) dark gray plates, fat 'o' getter, and copper grid posts).  It was pretty 'tight' sounding for the first week or so.. then, it opened up into something beautiful.  what a simply wonderful sounding tube.  Extremely silent background (like most all 12BH7/E80CCs), the way it's able to sound smooth & highly detailed is something to behold.  It boasts terrific imaging and excellent bandwidth, too.  I've enjoyed the Syl "house sound".. but found it to feel 'sleepy' and too laid back at times.. this tube shows how it should be done!  The more I listen to it, the more I realize it might be my favorite 12BH7 to date.  I'm looking forward to comparing it to the Raytheon 12BH7 I have coming next week.


----------



## olegausany

flysweep said:


> I've been rocking a Sylvania 12BH7 (w/ (curved) dark gray plates, fat 'o' getter, and copper grid posts).  It was pretty 'tight' sounding for the first week or so.. then, it opened up into something beautiful.  what a simply wonderful sounding tube.  Extremely silent background (like most all 12BH7/E80CCs), the way it's able to sound smooth & highly detailed is something to behold.  It boasts terrific imaging and excellent bandwidth, too.  I've enjoyed the Syl "house sound".. but found it to feel 'sleepy' and too laid back at times.. this tube shows how it should be done!  The more I listen to it, the more I realize it might be my favorite 12BH7 to date.  I'm looking forward to comparing it to the Raytheon 12BH7 I have coming next week.



Where you got it from?


----------



## JamieMcC

spacequeen7 said:


> what is the aluminium plate measurement on quickie guys , same size as the Crack's plate ?


 

 Its the same size as the Crack 6x10 inches my Quickie top plates fits my Crack enclosure.


----------



## spacequeen7

jamiemcc said:


> Its the same size as the Crack 6x10 inches my Quickie top plates fits my Crack enclosure.


 
 Thanks buddy 
	

	
	
		
		

		
		
	


	




 ..that's good news since I have two identical bases for Crack


----------



## Loquah

jamiemcc said:


> Its the same size as the Crack 6x10 inches my Quickie top plates fits my Crack enclosure.


 
  
My apologies then - I thought it was smaller. Perhaps because I have it on a metal enclosure that sits flush at the sides (i.e. no overhanging case) and I don't have my Crack anymore to compare.


----------



## JamieMcC

loquah said:


> My apologies then - I thought it was smaller. Perhaps because I have it on a metal enclosure that sits flush at the sides (i.e. no overhanging case) and I don't have my Crack anymore to compare.


 
  
 Looks good with the black top


----------



## grrraymond

So, in short, people would recommend the Quickie as another worthwhile upgrade to a SB'd Crack?
  
 I've got some Mundorf caps coming in and just bought a used rDac on eBay to see whether there's much of a noticeable difference from the Fiio E7 as a DAC. If so, I'll spring for something a bit more substantial towards the end of the year.
  
 I'm going to fit the 470 resistor switch as well. After a few days sitting with it, I think that the E80CC/TS5998 combo has lost a bit of bass with the resistor mod. The mids are wider and more detailed than ever but it's a little bit thinner in texture. I'd like to confirm my suspicions, as the initial added detail and mid-range separation got me very excited but I'm finding it doesn't quite hit the same spots.
  
 Caps will also be interesting.


----------



## MattTCG

This may get me lynched, but for me...the quickie made the biggest difference of all. That would include rolling in the TS 5998, Solen and Obbligato caps and even the speedball. 
	

	
	
		
		

		
		
	


	



  
 The sequence could also have some effect. I tried the quickie with all those mods already in place, so I'm not sure what the effect would be on a stock crack with the quickie. I'd certainly be interested to find out though.


----------



## grrraymond

My main concern is running something off battery power, just because it seems inconvenient. Is there any way to swap that for a mains current? I should probably check the Bottlehead forum, really. I'm sure it's been asked a million times.


----------



## MattTCG

I believe that the batteries are staying. The quickie upgrade PJCCs, about $35, is also part of the equation.
  
 Bottlehead now offers the Smash around the $350 price. A fellow member is building and testing and will report back. It will use regular main power.


----------



## Aeolus Kratos

matttcg said:


> I believe that the batteries are staying. The quickie upgrade PJCCs, about $35, is also part of the equation.
> 
> Bottlehead now offers the Smash around the $350 price. A fellow member is building and testing and will report back. It will use regular main power.


 
 I really can't wait to hear the impression on how the newly-released Smash paired with the Crack or other Bottlehead amps ( SEX and Mainline )


----------



## ramaka

Hi:
 Any thoughts on how Crack (no speedball upgrade yet) pairs with Cambridge Audio Dacmagic Plus DAC?


----------



## olegausany

ramaka said:


> Hi:
> Any thoughts on how Crack (no speedball upgrade yet) pairs with Cambridge Audio Dacmagic Plus DAC?



I still own but no longer use DacMagic Plus but the Crack i have has Speedball and other upgrades


----------



## ramaka

olegausany said:


> I still own but no longer use DacMagic Plus but the Crack i have has Speedball and other upgrades


 
 How was the SQ if and when you paired them?


----------



## Sonido

matttcg said:


> I believe that the batteries are staying. The quickie upgrade PJCCs, about $35, is also part of the equation.
> 
> Bottlehead now offers the Smash around the $350 price. A fellow member is building and testing and will report back. It will use regular main power.



That would be me. Should arrive roughly 2 months from now. Will get to compare side by side with Quickie. I'll even let Matt hear both side by side for a second opinion.


----------



## Sonido

matttcg said:


> This may get me lynched, but for me...the quickie made the biggest difference of all. That would include rolling in the TS 5998, Solen and Obbligato caps and even the speedball. h34r:
> 
> The sequence could also have some effect. I tried the quickie with all those mods already in place, so I'm not sure what the effect would be on a stock crack with the quickie. I'd certainly be interested to find out though.



I had a stock Crack with stock Quickie. Then I added the Speedball and a night later the PJCCS upgrade to the Quickie. I found that it was the PJCCS upgrade that made the largest difference as far as the bass and soundstaging is concerned for the entire setup.


----------



## olegausany

I never tried them together but can try either tomorrow or Wednesday but be aware that tubes used make big difference

By the those who like Philips E80CC / Tungsol 5998 pairing should also try Westinghouse 12AU7 labeled CONN black plates from '50 which same to me and are cheaper and easy to find


----------



## MattTCG

sonido said:


> That would be me. Should arrive roughly 2 months from now. Will get to compare side by side with Quickie. *I'll even let Matt hear both side by side for a second opinion*.


 
  
 Nice!! I accept your offer. 
  




  
 All the upgrades for the crack are appreciable. The TS 5998 was a nice move up the ladder. As was the speedball. But they still take a backseat to the  upgraded quickie.


----------



## FlySweep

olegausany said:


> Where you got it from?


 
  
 The 'Bay, my friend.  I got mine for what I'd consider a steal (considering this tube is pretty well regarded, from what I can tell).. here's a listing for a pair that looks identical to mine.


----------



## .Sup

matttcg said:


> I was there...I heard it...my mind was blown. :eek:




Hmm all that sounds great but I can't imagine at what position you have volume on Crack set if Quickie already amplifies the signal. I have mine set at 8.00 and if I go lower I get channel imbalance.


----------



## Sonido

I personally kept the Crack at 9 o'clock and used Quickie for volume control, which resulted in around 12 o'clock with my HD800. Someone needs to mod the Quickie tubes and PJCCS board into the Crack itself and use the Crack power. Then remove the volume control on the Crack and have it on the Quickie section solely.


----------



## olegausany

flysweep said:


> olegausany said:
> 
> 
> > Where you got it from?
> ...



Thanks for information but the only reason i asked is that you can get some tubes from online stores that have nothing to do with eBay


----------



## .Sup

sonido said:


> I personally kept the Crack at 9 o'clock and used Quickie for volume control, which resulted in around 12 o'clock with my HD800. Someone needs to mod the Quickie tubes and PJCCS board into the Crack itself and use the Crack power. Then remove the volume control on the Crack and have it on the Quickie section solely.




lol I also use the HD800 and my ears would explode (implode?) at 12 o'clock 
There is one thing I discovered not long ago is the difference in a DACs power output. An ODAC has a much lower output than my AGD Ref5. This means with ODAC I can actually go 9-10 o'clock. Still not sure if I could go twelve o'clock unless I don't clean my ears for a year lol


----------



## MattTCG

The volume control is actually improved with the quickie. Volume on the crack I leave at 9 and the quickie pot had lots of play. With the crack only the pot gets loud quickly.


----------



## olegausany

matttcg said:


> The volume control is actually improved with the quickie. Volume on the crack I leave at 9 and the quickie pot had lots of play. With the crack only the pot gets loud quickly.



Especially when you have stepped antenuator


----------



## Loquah

jamiemcc said:


> Looks good with the black top


 
  
 Thanks Jamie. Mine came as transparent yellow. Solid yellow would have been cool, but transparent made it look messy because you could see all the wires. I had the paint so I decided to spray it and am very happy with the results. 
  


grrraymond said:


> So, in short, people would recommend the Quickie as another worthwhile upgrade to a SB'd Crack?
> 
> I've got some Mundorf caps coming in and just bought a used rDac on eBay to see whether there's much of a noticeable difference from the Fiio E7 as a DAC. If so, I'll spring for something a bit more substantial towards the end of the year.
> 
> ...


 
  
 I personally found the Quickie plus Crack combo different, but not necessarily better. I definitely liked the extra volume range provided, but ended up using the Crack straight from my DAC. This might also depend on the sound characteristics of our sources though.


----------



## Sonido

loquah said:


> I personally found the Quickie plus Crack combo different, but not necessarily better. I definitely liked the extra volume range provided, but ended up using the Crack straight from my DAC. This might also depend on the sound characteristics of our sources though.




Could also have to do with the headphone you use. It seems the effect is most profound on Sennheisers (600, 650, and 800 are ones some of us have tried). I've also tried the combo with a Beyerdynamic T90 and the Quickie didn't improve things much.


----------



## Loquah

sonido said:


> Could also have to do with the headphone you use. It seems the effect is most profound on Sennheisers (600, 650, and 800 are ones some of us have tried). I've also tried the combo with a Beyerdynamic T90 and the Quickie didn't improve things much.


 
  
 Interesting. I was using it with T1s so that might make sense.


----------



## ffivaz

sonido said:


> I personally kept the Crack at 9 o'clock and used Quickie for volume control, which resulted in around 12 o'clock with my HD800. Someone needs to mod the Quickie tubes and PJCCS board into the Crack itself and use the Crack power. Then remove the volume control on the Crack and have it on the Quickie section solely.


 
  
 You can replace the crack pot with 100 kOhms resistors. That would sure improve the sound. I think, you can just connect wires white to white, red to red, black to black and put a 100 kOhms resistor between the ground lugs and center of each RCA... It could be also interesting to reduce the length of signal path by putting the RCAs closer to the front of the Crack.


----------



## grrraymond

I've just stuck a couple of 470K resistors in at the RCA jacks, as per the Crack FAQ on the BH forum. I was hoping to get a bit more action out of the Alps volume pot - I just can't get enough of that smooth action! - but while it's not made a massive difference (I can get it to 10, rather than 9:15), it does sound a bit cleaner. I was hoping to fit the E*)cc mod switches but only one turned up 
  
 Still, I've got the rDAC coming this arvo so I'm quite looking forward to that.
  
 Also, I've fitted a new set of pads to the 650s and that honestly makes as audible a difference as some tubes. Soundstage sounds a little bigger and bass is deeper. I guess it makes sense: better seal and ears a tiny bit further from the drivers. It could be in my head but everything sounds better than ever.


----------



## MattTCG

It's time for me to change my pads!!


----------



## grrraymond

Well, the rDAC is a significant step up from the Fiio E7. I was dubious but, as ever with the 650s, it's opened everything out further but also brought back the bass just a touch, right to my kind of level. Neither my headphones nor Crack have sounded this good. There's both depth and weight (some of this partly attributed to the new pads, as above) but I can hear added richness and control across the spectrum, where the E7 must have been hitting its ceiling.
  
 Again, I got a good deal on a used model, in excellent quality. I fully recommend for those looking to upgrade their DAC. It's probably even cheaper these days since the irDAC was released.
  
  
 Edit: The rDAC is much better than I first realised. I've just been listening to Panda Bear's Tomboy LP. It's one of my favourite records because of the songwriting but I've always begrudged some of the production choices, the vocals have always seemed like a fog of reverb, and the whole record sounds quite muffled. No longer, the harmonies are unbelievably thick but they now soar far above the delayed guitar chimes and chunky beats. It's like someone lifted a lid from the record and it sounds absolutely enormous, like I always imagined it could be. Wow. I fully recommend the record. It's as far away as you can get from a dry male vocal but the thickness and richness of those mids sounds unreal.


----------



## RonO

radiojam said:


> Cool!  Are you experienced with DIY? how long did it take?


 
 radiojam - 
  
 There are some significant gaps not in the time lapse, like the finishing of the wood and top plate - several hours of sanding, staining and painting.  I went back and looked at the times on the time lapse, the bulk of the photo's was a 9 hour span, which is the sort of close up soldering.  I found I also had some lapses of me testing it with the meter for voltages as well.  All in all I probably spent 20 hours.
  
 I had done some soldering of wiring since I was a kid in the late 70's, car stereo, minor repairs on stereo gear, but the main reason I built the Crack was because I wanted to hand assemble this kit, and hear it work at the end of the project.  I had a short when I powered it up, and blew up a resistor up across the power supply.  It took me 2 days to find the short, it was actually a tail on a resistor on the input tube that I failed to trim adequately, and it was touching the plate.  I cut off that tail, replaced the burned resistor, thanked the Bottlehead forum and set out to listen.  It took me about 6 weeks to even start the speedball because the stock amp is already so good.  I had HD-650's at the time (later switched to 600's), and it was so good I couldn't stop.


----------



## RonO

matttcg said:


> Nice!! I accept your offer.
> 
> 
> 
> ...


 
 Hey! I want in on this too.  
  
 RonO


----------



## MoatsArt

I am selling my Pure Crack to partially fund the new Bottlehead DAC. 

For those of you who haven't been following this new product, check it out here:

http://bottlehead.com/smf/index.php/topic,4086.0.html

There are few things I would sacrifice my Crack comparison project for (as it has been helping me through my depression), but the Bottlehead DAC is one of them. 

Will still be building my modded Crack, just not doing a step by step comparison.


----------



## Sonido

rono said:


> Hey! I want in on this too.
> 
> RonO


 

 Mini Bottlehead meet it is!


----------



## grrraymond

I would actually love to build another Crack now I feel more of a dab hand with a soldering iron and I think your comparison project was a great idea. I completely understand you wanting to fund the BH DAC, though. I honestly didn't realise a DAC made any difference until I upgraded my E7 to the rDAC yesterday and a year or so down the line, depending on how the BH DAC turns out, I can see myself doing similar.
  
 For the moment, I'm going to get stuck into cap upgrades and then, finally, I think I'll have topped out.


----------



## Loquah

moatsart said:


> I am selling my Pure Crack to partially fund the new Bottlehead DAC.
> 
> For those of you who haven't been following this new product, check it out here:
> 
> ...


 
  
 Bravo!!
  
 I wish I had something to sell to put towards the BH DAC, but alas, I sold so much gear to fund my LCD 2s and now I have to fund my wedding (which I wouldn't sacrifice for anything!) 
	

	
	
		
		

		
			




  
 However... if anyone in Australia is interested in having a Crack built for them (or a S.E.X. or Mainline) I would be glad to offer this service in return for some funds towards a BH DAC.


----------



## MoatsArt

Congrats, Lachlan. When's the big day?


----------



## Loquah

moatsart said:


> Congrats, Lachlan. When's the big day?


 
  
 Thanks Nathan! Feb next year.


----------



## punit

Lachlan , Congratulations. It great that she agreed to marry you in spite of your S.E.X & drug addiction.


----------



## JamieMcC

Lachlan Congratulations, will the groom on top of the cake be sporting a pair of headphones?


----------



## Koolpep

Congratulations, Lachlan!! I wish I had my hobby before I married and not after  Marriage is the best thing in the world, you will love it I am sure.
  
 Don't know if you know it already but for a week now, I am the proud owner of your first Crack with Speedball - since I could convince @punit to sell it to me.... The "box" draws a lot of attention and I love to listen to it...
  
 Many thanks and I can vouch for your great job with the Crack.
  
 cheers,
 K


----------



## punit

Koolpep  there is a small print in the our sales contract, I don't know if you have read it before signing, it says :
"The seller may borrow the Crack for a few days every couple of months"


----------



## Koolpep

punit said:


> Koolpep  there is a small print in the our sales contract, I don't know if you have read it before signing, it says :
> "The seller may borrow the Crack for a few days every couple of months"


 
 That is really very small. But of course - *anytime*!


----------



## Loquah

punit said:


> Lachlan , Congratulations. It great that she agreed to marry you in spite of your S.E.X & drug addiction.


 
  
  


jamiemcc said:


> Lachlan Congratulations, will the groom on top of the cake be sporting a pair of headphones?


 
  
  


koolpep said:


> Congratulations, Lachlan!! I wish I had my hobby before I married and not after  Marriage is the best thing in the world, you will love it I am sure.
> 
> Don't know if you know it already but for a week now, I am the proud owner of your first Crack with Speedball - since I could convince @punit to sell it to me.... The "box" draws a lot of attention and I love to listen to it...
> 
> ...


 
  
  
 Thanks folks! Lisa is very supportive of my addictions! I can't wait to show her our cake decoration, Jamie!


----------



## atraf

Can't make my mind if to purchase the Crack or something else like the vallhala or DarkVoice 336SE, I have the HD650 currently using Home Theater receiver which surprisingly does the job pretty well though i am still pretty sure i am not exploiting half of the HD650 ability..
  
 I listen to 70% Electronic music and 30% mix like ADELE, Arctic Monkeys,Kings of Leon. etc.
 The bass is important to me, does anyone have an idea which AMP would be best? I heard the crack has a more clear sound and a very big sound stage but not so impressive bass wise , I want a little more oomph in my Bass, will the crack do it? 
Does any one have experience with the other amps as well and can compare?


----------



## Zashoomin

atraf said:


> Can't make my mind if to purchase the Crack or something else like the vallhala or DarkVoice 336SE, I have the HD650 currently using Home Theater receiver which surprisingly does the job pretty well though i am still pretty sure i am not exploiting half of the HD650 ability..
> 
> I listen to 70% Electronic music and 30% mix like ADELE, Arctic Monkeys,Kings of Leon. etc.
> The bass is important to me, does anyone have an idea which AMP would be best? I heard the crack has a more clear sound and a very big sound stage but not so impressive bass wise , I want a little more oomph in my Bass, will the crack do it?
> Does any one have experience with the other amps as well and can compare?


 
 Get the crack...its fun (to build) , sounds good and is very flexible on sound because the the amount of tubes you can roll.  You will never look back.


----------



## MoatsArt

The bass on the Crack is exceptionally well controlled, particularly if you install the constant current source upgrade (Speedball) and roll a nice tube (Tung Sol 7236 is my favourite, but hard to find). 

In my experience, the Crack has bass that is tight, extended and just right in quantity (prominent when called for by source material).


----------



## Loquah

moatsart said:


> The bass on the Crack is exceptionally well controlled, particularly if you install the constant current source upgrade (Speedball) and roll a nice tube (Tung Sol 7236 is my favourite, but hard to find).
> 
> In my experience, the Crack has bass that is tight, extended and just right in quantity (prominent when called for by source material).


 
  
 +1 regarding the Speedball and with the right tube choice.
  
 I had a chance to hear a Darkvoice recently and was definitely impressed, but wouldn't say it's definitively better than a Crack and you don't get the fun of building it and modifying it yourself.


----------



## atraf

Thank you everyone for your responses.
  
 I don't know if a very controlled bass is what I need, I just want the HD650 to shake on my ears without it blending with everything else too much, got that effect when I heard them with the SS Naim DAC-V1, was amazing but extremely pricy!
  
 I hope I won't get lost with DIY, very little exprience 
 just to know what i am getting my self into, is the crack considered a quiet amp ? no hum's or buzz in the background i am very sensitive to that stuff and i read that OTL amps are sensitive to that issue.
  
Currently my budget is a bit tight, I have 600$ for DAC + AMP, so after buying the AMP i think i should leave the rest for a proper DAC so the SB upgrade will have to wait.
Which leads my to my next question  - which DAC under 300$ should I buy? 
What do you say on the AQ dragonfly v1.2/ HRT MicroStreamer combo with the CRACK, Since I have tight budget i thought buying something portable might be a nice bonus especially if it can drive a bit the HD650. 
 My future goal is the Bifrost but its 2 much right now


----------



## Loquah

atraf said:


> Thank you everyone for your responses.
> 
> I don't know if a very controlled bass is what I need, I just want the HD650 to shake on my ears without it blending with everything else too much, got that effect when I heard them with the SS Naim DAC-V1, was amazing but extremely pricy!
> 
> ...


 
  
 I've heard very good things about the Dragonfly v1.2 and having owned the previous version would say it's a probably good option.
  
 More importantly though, if you go for the Crack I'd highly recommend you get the Speedball straight away based on your requirements. The biggest impact of the Speedball is tighter, cleaner, punchier bass.
  
 As for the noise issue, the Crack is slightly more susceptible to induced noise than some other amps, but is nowhere near as bad as some of the similarly priced, but pre-built amps I have heard. You'd be fine with the Crack so long as you use some decent, shielded interconnects (some interconnects are 2-core, but not shielded) and so long as your environment isn't heavily polluted with EMF. I did fine even with wireless, a crappy laptop power supply and multiple other devices plugged in all around the Crack.


----------



## grrraymond

I'd say that the stock Crack has 'more' bass (with, say, a 6080 and ECC82) than with the Speedball but that once upgraded you get a better resolved bass sound, which ends up having more impact and allows all the low-mid details to come through, which are one of the key strengths of the 650s in my book.


----------



## Sonido

If you want bass *slam* get a Quickie with PJCCS as well.


----------



## MattTCG

sonido said:


> If you want bass *slam* get a Quickie with PJCCS as well.


 
  
 I think that this is one of those experiences that you need to have for yourself to believe it. I know that I was skeptical until I heard it at the meet. 
  
 I think that most people would be shocked at the bass slam the 650 is actually capable of.


----------



## JamieMcC

I will add the choke mod and a film cap in place of the last electrolytic cap in the power supply delivered a healthy improvement in deep bass with the T1's enough to let you feel some proper impact at times.


----------



## ffivaz

atraf said:


> Thank you everyone for your responses.
> 
> I don't know if a very controlled bass is what I need, I just want the HD650 to shake on my ears without it blending with everything else too much, got that effect when I heard them with the SS Naim DAC-V1, was amazing but extremely pricy!
> 
> ...




ODAC... And spend the rest on a speedball!


----------



## Loquah

ffivaz said:


> ODAC... And spend the rest on a speedball!


 
  
 Good suggestion!


----------



## atraf

I have heard the ODAC is very analytical and not warm at all, sounds like something I won't like, some even say its not adequate for headphones but more for speakers.. 
 correct me if I am wrong of course, the ODAC price is very tempting.
 Do you have experience with the ODAC and CRACK? the AQ 1.2 is also around the same price isn't it better? 
  
  
 So you guys really think the speed ball is a must when talking about electronic music and deep bass? and you also say I need different tubes, in total it can sums up to almost 500$.. I really thought I could just buy the stock crack with stock tubes and enjoy it even bass wise. 
 In the future the speed ball is definitely in mind and also tube rolling but for now I want to get the most out of the budget, with the purchasing the best upgradeable dac and amp in my price range.


----------



## JamieMcC

atraf said:


> I have heard the ODAC is very analytical and not warm at all, sounds like something I won't like, some even say its not adequate for headphones but more for speakers..
> correct me if I am wrong of course, the ODAC price is very tempting.
> Do you have experience with the ODAC and CRACK? the AQ 1.2 is also around the same price isn't it better?
> 
> ...


 
  
 Your budget is not that far away from something like a network player, nearly all now have a stand alone dac section that can be used with other inputs and a few some have built in headphone amps so you get you a nice dac with built in amp plus streaming features Dennon & Marantz normally both have Airplay streaming which is handy if use any idevices. I know its not a separate amp and dac however they are reasonably common in the hifi stores so a demo should be easy enough hearing something rather than buying blind would be a good way to go. With a limited budget it could be worth considering something like a used or even new Marantz NA7004 should be within budget.


----------



## Loquah

atraf said:


> I have heard the ODAC is very analytical and not warm at all, sounds like something I won't like, some even say its not adequate for headphones but more for speakers..
> correct me if I am wrong of course, the ODAC price is very tempting.
> Do you have experience with the ODAC and CRACK? the AQ 1.2 is also around the same price isn't it better?
> 
> ...


 
  
 Yeah, I think Dragonfly will be equally good and perhaps not quite as clinical sounding (although I haven't heard the new Dragonfly).
  
 You can absolutely start with the Crack in stock form and thoroughly enjoy it - it's actually recommended in a lot of cases so you can get to know the stock sound before upgrading. I recommended the SB add-on because of your comments about tight punchy bass (IIRC), but the Crack is never bass shy, it just gets a little tighter with the SB.


----------



## atraf

jamiemcc said:


> Your budget is not that far away from something like a network player, nearly all now have a stand alone dac section that can be used with other inputs and a few some have built in headphone amps so you get you a nice dac with built in amp plus streaming features Dennon & Marantz normally both have Airplay streaming which is handy if use any idevices. I know its not a separate amp and dac however they are reasonably common in the hifi stores so a demo should be easy enough hearing something rather than buying blind would be a good way to go. With a limited budget it could be worth considering something like a used or even new Marantz NA7004 should be within budget.


 
 A network player will be a bit 2 much for me.. I won't be using any of its capabilities since i only listen to music threw my laptop in my room and i already have pioneer receiver (vsx 521) for my 5.1 surround system in my room, if i could somehow connect them together and also gain an improvement in the speakers area or  maybe even somehow turning my set to 7.1 could be nice but still all this wifi capabilities and the main reason for having a network player won't be used by me.
  

 Do any of you know if I can use my receiver (vsx521) as a dac with the crack? what do i need to check for?
 I am asking because of the possibility of might saving the money on dac, maybe the receiver has a proper dac inside? 
 this is my receiver http://www.pioneer.eu/eur/products/archive/VSX-521/page.html, maybe using the Pre-amp Output of the Surround Back speakers?
i think the receiver won't send stereo audio to that output.. so maybe no :\ 
  
And of course thank you guys for everything.. I really like this headfi community and I am happy I finally bought the HD650 to be a part of it


----------



## Loquah

I'm not sure of the quality of the DAC, but you can absolutely use your receiver. I'd recommend using the BDR/DVR outputs. They should be fixed stereo feeds.


----------



## grrraymond

Again, just to clarify, the stock Crack is quite a bit warmer and bassier than the SB & common tube upgrade route. I absolutely loved the stock Crack sound, it's so fluid and has that ecstatic tube sound. When you want a bit more precision and focus, across the whole spectrum, get the SB.


----------



## ffivaz

atraf said:


> I have heard the ODAC is very analytical and not warm at all, sounds like something I won't like, some even say its not adequate for headphones but more for speakers..
> correct me if I am wrong of course, the ODAC price is very tempting.
> Do you have experience with the ODAC and CRACK? the AQ 1.2 is also around the same price isn't it better?
> 
> ...


 
  
 The stock Crack is musical. It's warm but not laid back or "tubey". The HD 650 are also on the warm side of headphones. Don't get me wrong : that is nice, I can listen to them for hours without any fatigue (like I get with, say, grados). So IMHO, I think you can get a clinical or analytical DAC. Now for the SB, I don't think it changed the sound signature of the Crack, only everything the Crack did well was even better : tight bass, excellent mids and precise trebble!


----------



## Loquah

ffivaz said:


> The stock Crack is musical. It's warm but not laid back or "tubey". The HD 650 are also on the warm side of headphones. Don't get me wrong : that is nice, I can listen to them for hours without any fatigue (like I get with, say, grados). So IMHO, I think you can get a clinical or analytical DAC. Now for the SB, I don't think it changed the sound signature of the Crack, only everything the Crack did well was even better : tight bass, excellent mids and precise trebble!


 
  
 +1 to all of this


----------



## grrraymond

GEC Brown Base, then. 

If I'm running a SB Crack with 5998 & E80CC, plus resistor mod, what would the brown base add, potentially. 

I know some on here have owned both but predominantly use the 5998. What's the difference, to your ears/tastes?


----------



## JamieMcC

Have you seen Nick Tams multi 6as7g review?
  
 Personally I like the micro detail as it reveals the subtleties of tone & timbre in voices or the pluck and reverb of a string or weight of piano key strike and how the note decays. Its at a different level resolution wise if you like vocals like say Eva Cassidy. But this comes at a premium cost, is it worth the extra with a stock Crack I don't know. But I think the sound is rather special but then my Cracks not stock and I listen using my T1's as my HD650's just cant resolve at the same level.
  
 I would also suggest you need to be receptive to the differences if your working surfing or playing games while listening then I doubt the differences will come across well.     
  
http://the-key.enix.org/~krystal/review-tube-bottlehead.html


----------



## bigfatpaulie

jamiemcc said:


> I would also suggest you need to be receptive to the differences if your working surfing or playing games while listening then I doubt the differences will come across well.


 
  
 I really agree with this.  I think a lot of what is talked about when it comes to small differences like this are really only apparent when taking the time to savor the music; at least for me.


----------



## grrraymond

Thanks for that. I'd never seen Nick Tam's reviews because the OP seems cut short/can't find the link on the current iteration of the BH forum.
  
 My Crack has SB upgrade and Mundorf caps coming next week. I do tend to only listen to music when I'm doing nothing else but I'm still not sure whether it sounds like a worthwhile investment. Seems a Quickie might be more significant if I'm going to spend the money.
  
 They don't come around too often so the one on eBay UK currently has got me tempted. I'm sure someone will snap it up in any case.


----------



## .Sup

atraf said:


> I have heard the ODAC is very analytical and not warm at all, sounds like something I won't like, some even say its not adequate for headphones but more for speakers..
> correct me if I am wrong of course, the ODAC price is very tempting.
> Do you have experience with the ODAC and CRACK? the AQ 1.2 is also around the same price isn't it better?
> 
> ...




ODAC is not analytical at all and is a GREAT DAC, especially for the price. Its very airy, it separates everything nicely so its not congested together like vocals and instruments on some other DACs. For electronic music I would get speedball for its speed and response but like others said enjoy stock Crack first.


----------



## Rune3400

I have been searching this thread without finding any mention of the *SQ benefits of playing the amp at full volume*???

 Of course normally this would mean blowing out your ears, but that's why you use a passive preamp to control the volume instead.
 It's a trick I picked up with my last tube amp that had channel imbalance at low levels. ATM my Crack SB is set to max volume and my passive preamp to around -40db. 

 The sound difference is quite extreme. Highs are much more crisp and beats more punchy. *All in all the sound is much, much more dynamic.* It's like going from a 50$ DAC to a 500$ DAC IMHO.

 Why havn't I seen anyone mention this? Is there something I don't know? Does it hurt your tubes to play at max volume all the time? What's the catch? 
	

	
	
		
		

		
			





 -Rune


----------



## MoatsArt

Soon I will be experimenting with this. Actually, I will be removing the volume pot on the Crack all together, throwing in a couple of 100K resistors and controlling volume via Submissive (Bottlehead's passive pre-amp). Looking forward to seeing what difference this makes.


----------



## grizzlybeast

I know this is random but I wanted to make my bottlehead crack with speedball upgrade a colorful orange and rit dye with alcohol did the trick. I need to apply another coat and then varnish it after im done.
 
knob looks kinda goofy though minimalist.


 
@Zashoomin did a good job on my build as well. Me coloring it was the easy part. and its like an automatic bass boost to the hd650. Everything sounds a little more solid and tighter overall... not just the bass.


----------



## MoatsArt

Mmm....

A Jaffa Crack.

http://en.wikipedia.org/wiki/Jaffas

Brilliant colour scheme if you ask me.


----------



## JamieMcC

rune3400 said:


> I have been searching this thread without finding any mention of the *SQ benefits of playing the amp at full volume*???
> 
> Of course normally this would mean blowing out your ears, but that's why you use a passive preamp to control the volume instead.
> It's a trick I picked up with my last tube amp that had channel imbalance at low levels. ATM my Crack SB is set to max volume and my passive preamp to around -40db.
> ...


 

 Yes I have noticed a similar thing also when using with my turntable, my phono-stage which has adjustable gain if I set it right down low I can listen with the Crack at its max volume.


----------



## JamieMcC

That Cracks been Tangoed, I like it!
  
http://www.youtube.com/watch?v=NhOeG-uTJxw


----------



## MoatsArt

Ooh, Tony. That might be worth a little replay!


----------



## bleudeciel16

Doing my first listen as we speak!
  
 I was impatient and it's 3am so I wasn't able to assemble the box quietly (hammers aren't known for being quiet, yeah?), so I used a copious amount of masking tape to temporarily hold it together while testing.
  
 Mids are definitely lush.  Reminds me of my HD595 + LD II++ pair I had.  Only with better bottom end and better soundstage.
  
 At first, I felt I lost some sparkle on the top end, but then again, the HD650's aren't known for being sparkly.  I stopped thinking about that, and concentrated on the mids.  The delicious smooth and warm mids.  Man.  Good stuff.
  
 So far, I'm impressed.  Have a lot more listening to do though!  I don't think I'll be selling my Lyr through.  It's still a great amp and I'm sure I'll regret selling it if I ever get an Ortho or something to drive.
  
 Will return with pics and impressions once I get more listening time.


----------



## JamieMcC

bleudeciel16 said:


> Doing my first listen as we speak!
> 
> I was impatient and it's 3am so I wasn't able to assemble the box quietly (hammers aren't known for being quiet, yeah?), so I used a copious amount of masking tape to temporarily hold it together while testing.
> 
> ...


 

 See if you can find yourself a nice 1950's 12au7 Tung-sol JTL they are a little more expensive than the RCA 12au7 clear top but are more refined and resolving whilst still retaining that treble sparkle that the cleartops have that works well when in combination with the HD650.


----------



## punit

jamiemcc said:


> See if you can find yourself a nice 1950's 12au7 Tung-sol JTL they are a little more expensive than the RCA 12au7 clear top but are more refined and resolving whilst still retaining that treble sparkle that the cleartops have that works well when in combination with the HD650.


 

 Have you tried the Amperex Bugle Boy 12AU7 ? I found it even better than the TS 12AU7.


----------



## JamieMcC

punit said:


> Have you tried the Amperex Bugle Boy 12AU7 ? I found it even better than the TS 12AU7.


 
  
 Yes I have but preferred the early 1950's Tung-sol JTL &TS Black glass to it. However it was in my early days of rolling and I expect it might have been one of the very many latter Bugle boy versions & not the early 7316 flasher one which is meant to be the premium version that most of the reviews look to be based on.
  
 The later Tung-sol 12au7 also don't seam to be as nice sounding as their earlier tubes. Once I switched from the HD650 to the T1's I found the Mullards and E80cc's more to my liking mainly because the T1's didn't benefit from the brighter sounding tubes like the HD650's did.
  
 Its quiet surprising how different combinations work together or don't as the case may be. I have one TS5998 that is particular about which brand of e80cc its paired with yet works fine with all other E80cc & 12au7 variants etc.


----------



## MoatsArt

So, Jamie, how many tubes do you have for your Crack? Photos please!


----------



## JamieMcC

moatsart said:


> So, Jamie, how many tubes do you have for your Crack? Photos please!


 
  
 Enough and then some, my stash has been slowly growing and I have been letting a few go to fund some other related purchases


----------



## Armaegis

Sell some tubes, buy their dac


----------



## audiowize

rune3400 said:


> I have been searching this thread without finding any mention of the *SQ benefits of playing the amp at full volume*???
> 
> Of course normally this would mean blowing out your ears, but that's why you use a passive preamp to control the volume instead.
> It's a trick I picked up with my last tube amp that had channel imbalance at low levels. ATM my Crack SB is set to max volume and my passive preamp to around -40db.
> ...


 
 At maximum volume, the level control functions as a pair of 100K resistors at the input. This isn't an operational problem unless you don't have a different way of controlling the signal coming in.


----------



## JamieMcC

armaegis said:


> Sell some tubes, buy their dac


 
  
 I would love to and have no doubt their dac is going to sound wonderful however personally its to much for me to spend on product which I am electively buying unseen, unheard, requires some assembly and which falls in a category of product type which historically becomes obsolete rather swiftly.  Its also at a price level which if you don't mind if buying used its possible to find some very highly regarded options.
  
 I am looking forward to hearing some reviews if its as good as we hear then it will be around for a long time.


----------



## i luvmusic 2

Do you guys have a list of tubes for CRACK?


----------



## Keithpgdrb

i luvmusic 2 said:


> Do you guys have a list of tubes for CRACK?


 
 go to the bottlehead forums.  there is a list under the crack thread. "tube rolling with the crack" I think its called.


----------



## i luvmusic 2

keithpgdrb said:


> go to the bottlehead forums.  there is a list under the crack thread. "tube rolling with the crack" I think its called.


 
 THANK YOU!


----------



## listen4joy

how is the bottlehead for hd800? and can i buy it complete? without building it?


----------



## MoatsArt

1. The Crack is a great budget option for the HD800s. Some would call it a giant slayer.
2. Where do you live? Bottlehead can put you on to a builder they use or, alternatively, there are many on this forum who would be happy to build one for you at a reasonable cost.


----------



## MattTCG

listen4joy said:


> how is the bottlehead for hd800? and can i buy it complete? without building it?


 
  
 The impressions that I've read of the hd800 and crack are quite good. I'm even considering the pairing myself. 
	

	
	
		
		

		
		
	


	




 
  
 I'm still looking for a TS 5998 or comparable if anyone is selling.


----------



## Aeolus Kratos

listen4joy said:


> how is the bottlehead for hd800? and can i buy it complete? without building it?


 
 I'm using the HD800 with my Crack, though the sound is pretty good, I MUCH prefer the T1 with the Crack. When I heard the T1 driven by the Crack then switched over to the HD800, I immediately felt kind of lush and it lacks of transparency as well as the clarity of the T1.
  
 I think you should seriously consider the T1 for the Crack as well.


----------



## benjaminhuypham

@Aeolus Kratos: I heard your Crack with HD650 last Summer and oh man! they sounded so incredibly cracky. I may not be able to afford T1, but I may go with T90. How do T90/Crack+speedball versus T1/crack+speedball guys? I'd love to hear from someone who have heard both setups before making a decision.


----------



## punit

benjaminhuypham said:


> @Aeolus Kratos: I heard your Crack with HD650 last Summer and oh man! they sounded so incredibly cracky. I may not be able to afford T1, but I may go with T90. How do T90/Crack+speedball versus T1/crack+speedball guys? I'd love to hear from someone who have heard both setups before making a decision.


 

 I owned both HP's with the Crack. I sold the T90. Please see my comments in the post linked below. At first I felt that T1's were a slight improvement over T90 but as I grew familiar with T1's I couldn't go back to T90.
  
 http://www.head-fi.org/t/607079/beyerdynamic-t90-d/1770#post_10294814


----------



## benjaminhuypham

Thank you Pupit, very well done comparison, beautiful legs =) as T1 sound.


----------



## .Sup

armaegis said:


> Sell some tubes, buy their dac




Is it out already?


----------



## olegausany

Highly moded Crack i got from Matt is great with HD800, i also had stock one with Speedball and it was great too so i got one again cause i was missing it's sound 

Sent from my LG-V500 using Tapatalk


----------



## atraf

Just ordered the crack, Hope it was the right choice  
  
 Can any of you tell me how long does it usually take for them to ship it?


----------



## MattTCG

Depends. Mine was about four weeks.


----------



## Keithpgdrb

atraf said:


> Just ordered the crack, Hope it was the right choice
> 
> Can any of you tell me how long does it usually take for them to ship it?


 
  
  


matttcg said:


> Depends. Mine was about four weeks.


 
 I got my speedball order in about a week.


----------



## atraf

Just to make sure we are talking about the same thing, are you talking about the time it took for them to ship it or the time it actually arrived to your doorstep ?


----------



## MattTCG

My kit with SB was four weeks from when the order was placed to arriving at the door.


----------



## grrraymond

On the BH website, there is a delivery status page which will give you a decent indication of where they're up to with orders/shipping.
  
 http://bottlehead.com/bottlehead-kit-delivery-status/


----------



## Aeolus Kratos

benjaminhuypham said:


> @Aeolus Kratos: I heard your Crack with HD650 last Summer and oh man! they sounded so incredibly cracky. I may not be able to afford T1, but I may go with T90. How do T90/Crack+speedball versus T1/crack+speedball guys? I'd love to hear from someone who have heard both setups before making a decision.


 
 Thanks for the kind words, Benjamin, it's my pleasure. Glad you enjoyed my setup


----------



## walls

Finally got my Crack finished. I'm gonna run it without the Speedball for a while then install it so I can hear the difference for myself.


----------



## atraf

Nice build ^^^ 
 how did it go ?


----------



## .Sup

looks great walls!


----------



## atomicbob

walls said:


> Finally got my Crack finished. I'm gonna run it without the Speedball for a while then install it so I can hear the difference for myself.


 
 Very nice! That was my plan when I started nearly a year ago. Rolled some tubes. Still listening to the stock crack, even though I have the SB upgrade sitting here. I just enjoy the euphonic presentation so much, especially with the HD800 and T90. I sometimes put on the T1, but not nearly as often as the the other two. HD800 and Crack lean towards an electrostatic sound with better bass. The T90 + Crack lean towards a planar sound but with better treble though a little less really low bass.


----------



## MattTCG

I just picked up the last ts5998 from vacuumtubes.net


----------



## walls

Thanks! 

Very easy build, only problem I had was with the tiny LED's on the bottom socket. They are SO small. 

The directions are almost full proof, just read everything twice. Main thing to pay attention to IMO is when they specify ATTACH and SOLDER. Only SOLDER when the directions sate it's time to do so or you will be using the solder wick. Lol. 
When you unpack your kit don't let the parts scare you, just take your time and you will do fine.

I'm gonna use mine as is for a while and then start modding,


----------



## atraf

walls said:


> Thanks!
> 
> Very easy build, only problem I had was with the tiny LED's on the bottom socket. They are SO small.
> 
> ...


 
 thanks can't wait for it to arrive 
 did you use particular solder ? i read it should be wire 63/37 with rosin core solder, am i correct or it doesn't really matter?


----------



## JamieMcC

The Cardas Quad Eutectic solder is good and easy to work with, you will see a lot of the diy cable guys and hard core builders swear by it 3 meters is all you need to build a Crack+Speedball, that's only a couple of dollars worth and its easy to find on ebay. Its got to be good from a resale point also.


----------



## walls

This is what I use. 




Unless your planning for a whole bunch of builds this is plenty. I am building another Crack for a friend and figure to have more then enough on this one roll for at least four complete builds.


----------



## atraf

Thanks you for the info, nice setup you got there  
 Ordered the Cardas


----------



## grrraymond

I swapped in some 100uf 250v Mundorf caps and I'm frankly very very surprised with the results. They've actually changed the presentation of everything I've put through them and I've been listening to music I haven't enjoyed for years, absolutely buzzing. I was very skeptical of the changes these would bring (partly because I'm electronics ignorant) but even after a few hours, they've tightened up in the bass and it's at the perfect level for me. The mids and top end, meanwhile, are so detailed and nicely separated but it's the overall presentation which is perfect. I wouldn't say the sound is rolled off, it's just much better controlled on the top end and every single song I've run through them over the past few hours sounds so cohesive. There are certain songs which have elements panned a little too wide or the trumpet is a touch too bright but everything sounds just in its right place. I've never heard bass like it, either, on open cans. I can't imagine what it will be like once they've had a couple of hundred hours to burn in.
  
 Many thanks to those who inspired me to give them a go.


----------



## ModestMeowth

matttcg said:


> I just picked up the last ts5998 from vacuumtubes.net


 
 Hopefully it isn't as microphonic as the last two I received from them


----------



## MattTCG

yikes! I hope not also. 30 day return policy I suppose.


----------



## Loquah

grrraymond said:


> I swapped in some 100uf 250v Mundorf caps and I'm frankly very very surprised with the results. They've actually changed the presentation of everything I've put through them and I've been listening to music I haven't enjoyed for years, absolutely buzzing. I was very skeptical of the changes these would bring (partly because I'm electronics ignorant) but even after a few hours, they've tightened up in the bass and it's at the perfect level for me. The mids and top end, meanwhile, are so detailed and nicely separated but it's the overall presentation which is perfect. I wouldn't say the sound is rolled off, it's just much better controlled on the top end and every single song I've run through them over the past few hours sounds so cohesive. There are certain songs which have elements panned a little too wide or the trumpet is a touch too bright but everything sounds just in its right place. I've never heard bass like it, either, on open cans. I can't imagine what it will be like once they've had a couple of hundred hours to burn in.
> 
> Many thanks to those who inspired me to give them a go.


 
  
 I've just finished a Crack build for a friend with some larger Nichicon power caps (470uF) and a pair of Mundorf MCaps for the output. After a short listen (not fully burned in) I'd say the MCaps sound much like you're describing. Did you use MCaps or Supremes?


----------



## grrraymond

I used the MCaps but from looking at Rasmus's DIY blog, I think I'll also pick up some 1uF Supremes to bypass them, just to see what happens. I can snip them out quite easily if I don't like the results. Still waiting for the 2.2 uF to bypass the 3rd PSU cap, too.
  
 Am I right then that the Nichicon caps are replacing caps 1&2? Any discernible results from that?
  
 Also, anyone got any thoughts on choking the PSU?


----------



## Loquah

grrraymond said:


> I used the MCaps but from looking at Rasmus's DIY blog, I think I'll also pick up some 1uF Supremes to bypass them, just to see what happens. I can snip them out quite easily if I don't like the results. Still waiting for the 2.2 uF to bypass the 3rd PSU cap, too.
> 
> Am I right then that the Nichicon caps are replacing caps 1&2? Any discernible results from that?
> 
> Also, anyone got any thoughts on choking the PSU?


 
  
 Unfortunately, due to time constraints, I built it straight to modified spec rather than starting stock and upgrading so I can't comment on the sound of the Nichicons in the power supply. I used 3 x 470uF caps in place of the stock 220uF caps. It's a bit of a squeeze and not as tidy, but the larger caps provide lower resistance to ground which is meant to be beneficial.


----------



## grrraymond

I thought that was the case from the post above. As ever, though, if it doesn't hurt, it's worth a go. A few months ago, I wouldn't have even considered half the little things I've done to the Crack. In fact, it took me a long time to even consider building the Crack in the first place but I'm enjoying this side of the hobby, too. Fortunately, it sounds so good that I'm not listening to the gear, I'm finding the music more engaging than ever.
  
 I had a great night last night, I must have spent about six hours on the HD650s as I had the house to myself til later in the evening, and I couldn't really sleep once my missus came in and went straight to bed, so sneaked up to the den for another couple of hours! Incidentally, I've never been convinced by classical on the 650s, and specifically by the presentation of strings, but the Mundorf caps have made a real difference there. I was listening to the Intermezzo from Mascagni's Cavalleria Rusticana and the rising swell of those strings brought a tear to my eye. Everything in its right place. Then I went onto Pavarotti and was just gobsmacked. You get a slightly forward presentation of lead vocals but there's so much happening in the background that's perfectly balanced, too.
  
 And I've just stumped up for that GEC Brown Base on eBay UK. Looking forward to comparing with the TS5998.


----------



## Loquah

grrraymond said:


> I thought that was the case from the post above. As ever, though, if it doesn't hurt, it's worth a go. A few months ago, I wouldn't have even considered half the little things I've done to the Crack. In fact, it took me a long time to even consider building the Crack in the first place but I'm enjoying this side of the hobby, too. Fortunately, it sounds so good that I'm not listening to the gear, I'm finding the music more engaging than ever.
> 
> I had a great night last night, I must have spent about six hours on the HD650s as I had the house to myself til later in the evening, and I couldn't really sleep once my missus came in and went straight to bed, so sneaked up to the den for another couple of hours! Incidentally, I've never been convinced by classical on the 650s, and specifically by the presentation of strings, but the Mundorf caps have made a real difference there. I was listening to the Intermezzo from Mascagni's Cavalleria Rusticana and the rising swell of those strings brought a tear to my eye. Everything in its right place. Then I went onto Pavarotti and was just gobsmacked. You get a slightly forward presentation of lead vocals but there's so much happening in the background that's perfectly balanced, too.
> 
> And I've just stumped up for that GEC Brown Base on eBay UK. Looking forward to comparing with the TS5998.


 
  
 It'll be interesting to see what you think of the Brown Base combined with the MCaps. The Crack I've just built has some Russian 6AS7 equivalent 6H13 (or something similar) and the combo of the tube plus the MCaps is creating a beautiful rich soundstage and really nice texturing, especially in strings so it'll be interesting to hear if the brown base improves this or just changes it as I found the GEC to be warmer and lusher which I liked, but it's different as far as I can remember.


----------



## pduk

modestmeowth said:


> Hopefully it isn't as microphonic as the last two I received from them


 
 I just got my 5998 from them this morning and it's fine -- very very slight microphony but perfectly acceptable in a headphone amp and only perceptible if I bash the desk... which I'm not in the habit of doing 
  
 Paul.
  
 PS My first post! Been reading for ages but never posted before.


----------



## MattTCG

^^ Congrats on the first post and welcome. I hope that I have as much luck as you with the TS5998. They have become a rare bird indeed. I believe that this is referred to as the head-fi effect.


----------



## JamieMcC

grrraymond said:


> Also, anyone got any thoughts on choking the PSU?
> 
> 
> And I've just stumped up for that GEC Brown Base on eBay UK. Looking forward to comparing with the TS5998.


 
  
 Graham l really hope you enjoy the GEC, I posted it first thing this morning 1st class. I originally purchased it as tested strong and have only used it sparingly rotating its usage with my other GEC's & 5998 tubes. I'm looking forward to hearing your impression of it with those Mundorfs.
  
 I was pleased with the results from choking the psu and replacing the last electrolytic with a film cap. Dynamics, bass, and venue acoustics on live recording stood out as the most noticeable areas that benefitted from the mod along with a blacker background.
  
 The guys on the bh forum walked me through the mod. 
  
  http://bottlehead.com/smf/index.php/topic,6030.0.html


----------



## grrraymond

Thanks for that, Jamie. That's sooner than I'd expected. I'm really looking forward to it. Will post up impressions as they develop.
  
 I'll have a more detailed read of the choke mod too, it seems more straightforward than I'd expected.
  
 I must say, this is one of the best projects I've gotten into for a good few years. Really enjoying myself.


----------



## JamieMcC

Here are some figures for the choke Mod.
  
 I used to 2 Short U-Shaped Brackets mounted back to back to mount the choke on £4-5 delivered
  
 Triad C7X 10H 90mA smoothing choke £16-£20 delivered
  
 Film cap plenty to choose from suit all budgets cheap motor runs or premium audio caps
  
 5x Small bolts, nuts washers to mount the choke and U brackets, a couple of pounds.
  
 One of the things to bear in mind is ground clearance if you use a big film cap.


----------



## MattTCG

I have the ts5998 due in tomorrow from vacuumtubes.net  Hoping that I have a noise free tube!!


----------



## MoatsArt

Crack + Submissive = Win!

Clarity and speed.

Cap upgrade (Obbligato Gold) also helping. 

RCA clear top up front with TS 7236 in pride of place up the back.

:biggrin:


----------



## listen4joy

how is the crack pair with schiit modi? 
 and i understand that i need 3 cables right?
 2 rca to rca 
 and one usb to mini usb?
  
 give some tips for good cables thnx exept blue jeans because the shipping expensive..


----------



## grrraymond

Thanks, so it seems like a perfectly affordable and quite fun mod. I think the biggest challenge will be space and fit.
  
 I'm still burning in these Mundorfs so will give it a little while to see how these change before taking the next step.
  
 Obviously, I'll be rolling in that GEC first thing!


----------



## MoatsArt

Just bought 8 x Tung Sol 7236 tubes that had been relabelled (incorrectly) as 5998A's by Sylvania. All eight sound stunning and most test new. I think I'm set for life!


----------



## MattTCG

moatsart said:


> Just bought 8 x Tung Sol 7236 tubes that had been relabelled (incorrectly) as 5998A's by Sylvania. All eight sound stunning and most test new. I think I'm set for life!


 
  
 Dang, nice find!! Today I'll be setup again on my favorite chain. uberfrost>quickie>crack>650.


----------



## JamieMcC

Latest caps rolled in the Crack.
  
 A pair of pre-loved EPCOS (Siemens) 750v100uf polypropylene in oil films (non audio caps).
  
 These are very nice sounding caps imho and seem to be the equal to any of the audio branded mkp films I have tried to date while also providing that liquid effortlessness in presentation that only the pio's can do yet combined with plenty of details and rich smooth vocals.
  
 I later tried bypassing them with a pair of Hovland Supercaps 1uf/400vdc with good effect. Increased detail and clarity a sense of intimacy in vocal presentation with some familiar tracks. With the Hovland's added the presentation also felt slightly faster than that of Epcos PIO's on their own.


----------



## MattTCG

^^ You are truly a mad scientist sir. In the best way.


----------



## uelover

jamiemcc said:


>


 
  
 This is truly beyond my level.


----------



## JamieMcC

They turned out to be smaller than what I initially thought at about 120mm x 60mm not including the fixing stud which sticks out about 10-15mm from the base with a bit of shoe horning I think these will fit in the Cracks enclosure I just checked they are a tad smaller than the Obbligato Film Oils which are 65mm diameter x 135mm so should fit. 
  
 I have just connected them externally with fly leads at the moment.


----------



## grrraymond

My neighbour, who never ever goes out, went out despite my best bribery, so no brown base today but I'll be at the Post Office tomorrow for 6am, sharp!
  
 Meanwhile, I'm really happy with how these these Mundorfs are changing as the hours go by. On day two, they were almost too bright, almost thin in the mids, there was so much detail. They're filling out again now, the bass is superb but the mids have come back with detail and, crucially, that lushness that makes the HD650s.
  
 Listening to something like Random Access Memories, there are so many layers of keys and synths and choppy guitar, adding colour and groove. I knew it was an incredibly well-produced record but I'm peeling back further and further.


----------



## MattTCG

Just got my ts5998 from vacuumtubes.net.  There are three small chips of glass floating inside. 
	

	
	
		
		

		
			





  That can't be good. Is it toast? Won't have the crack ready till tomorrow so I can't test it today.


----------



## MattTCG

Here's a pic. Not sure if it will show visibly.


----------



## JamieMcC

I have had several tubes including 5998s with glass chips in all have worked perfectly. Its something that sometimes happens during manufacturing  apparently.


----------



## grrraymond

Mine evidently has a microscopic chip somewhere because I can hear it gently rattle but can't see it!


----------



## MattTCG

Okay. Maybe there is hope afterall.


----------



## bigfatpaulie

matttcg said:


> Okay. Maybe there is hope afterall.


 
  
 Apparently it is totally normal to have glass chips in a 5998.  All 4 that I've had had them...  All 4 had problems mind you...


----------



## MattTCG

I've had two other 5998's with no glass. One developed a slight hum during warmup but then was dead quiet. The other was perfect...
  
 Great job by vacuumtubes though. Very quick shipping and well packed in the box. Very friendly on the phone as also. I'd do business with them again even if there is a problem with this tube.


----------



## grizzlybeast

*is there supposed to be buzzing/humming at low levels with my crack/speedball?*
  
 If not what could be the problems. I had this with other amps and know its common but its a little bit louder on the crack/speedball.
  
 I am thinking its the kind of tube I am using "*RCA 6AS7G JAN Black Plates"*. The stock 6080 did this even worse.


----------



## grrraymond

In short, no, no hum at listening levels. If you've identified whether or not it's the tube, your best bet is to ask on the Bottlehead forums and there will be some very helpful chaps there to help you isolate the problem.


----------



## Keithpgdrb

no, there shouldn't be a hum.. Now, if your using low impedance cans, then yes, you will hear a hum.
  
 I had this same issue.  if its not the tube itself, (I had 2 stock tubes that were both noisy) then double check your wire routing around the tubes.  I had routed a wire under a tube instead of around it, and it caused hum.  also make sure you do all the corrections on the crack support page.  all that will help.


----------



## .Sup

matttcg said:


> Dang, nice find!! Today I'll be setup again on my favorite chain. uberfrost>quickie>crack>650.



Quickie>Crack combo is from now on called Crackie, okay?


----------



## skeptic

Crack should run dead silent.  I've only tried mine once with low Z phones, and frankly I don't recall hearing any noise then either.
  
 I believe Doc posted something a few pages back about a suspect batch of transistors that may have been included with certain speedball orders.  Did your crack make this noise in its stock build?  If not, I believe BH said they would supply the replacement transistors free of charge.  
  
 Alternatively, if it did buzz or hum in stock form, I would try the following: (1) plug it in in a different room to see if it might be some other appliance polluting your AC and causing the issue (like a light with a dimmer); (2) swap in a new 12au7 to ensure that isn't the culprit; (3) check that the input wiring from your rca's to pot are braided as tightly as recommended in the manual; and (4) touch up your solder joints on ground - although honestly, in my experience, a bad connection here makes a much louder buzz than what you're describing.  Hope this helps!


----------



## skeptic

jamiemcc said:


> Latest caps rolled in the Crack.
> 
> A pair of pre-loved EPCOS (Siemens) 750v100uf polypropylene in oil films (non audio caps).
> 
> ...


 
  
 Pretty cool!  Those bad boys are giving me flashback's to adamct's crazy: http://www.head-fi.org/t/679064/maxxximum-capacity-crack
  
 Somewhat seriously....I hope his absence from the crack thread in recent months is due to a new hobby and not inadvertently touching the exposed leads on those PSU caps....


----------



## MattTCG

.sup said:


> Quickie>Crack combo is from now on called Crackie, okay?


 
  
 Good one..."crackie" it is.


----------



## Serenitty

.sup said:


> Quickie>Crack combo is from now on called Crackie, okay?


 

 How about Quack?


----------



## JamieMcC

bigfatpaulie said:


> Apparently it is totally normal to have glass chips in a 5998.  All 4 that I've had had them...  All 4 had problems mind you...


 
  
 Sounds like you have been very unlucky. I'm still drooling over the Omega by the way.


----------



## mordicai

matttcg said:


> Here's a pic. Not sure if it will show visibly.


 
 Oh no Matt, that's really bad. I'll do you a favor and take it off your hands for 10 bucks.


----------



## mordicai

Some people are having the same problem with the Crack. According to Doc they had some bad transistors from a supplier. I assume you have Speedball, because that is where the problem is. Go to the Bottlehead Crack forum for info. My replacement  transistors arrived from Bottlehead today.
  


grizzlybeast said:


> *is there supposed to be buzzing/humming at low levels with my crack/speedball?*
> 
> If not what could be the problems. I had this with other amps and know its common but its a little bit louder on the crack/speedball.
> 
> I am thinking its the kind of tube I am using "*RCA 6AS7G JAN Black Plates"*. The stock 6080 did this even worse.


----------



## bigfatpaulie

jamiemcc said:


> Sounds like you have been very unlucky. I'm still drooling over the Omega by the way.


 
  
 Yeah, I've had NO LUCK with 5998's.  Admittedly, I _have _been lucky with Omegas.


----------



## MattTCG

mordicai said:


> Oh no Matt, that's really bad. I'll do you a favor and take it off your hands for 10 bucks.


 
  
 Sure. Just hit my pp account and wait by the mailbox.


----------



## olegausany

matttcg said:


> Just got my ts5998 from vacuumtubes.net.  There are three small chips of glass floating inside.
> 
> 
> 
> ...



I found a pair of 5o998 online but was warned that they have same thing like yours but they work fine in the amp they tested them with. I also read that such thing sometimes happens but still should cause no problems


----------



## MattTCG

olegausany said:


> I found a pair of 5o998 online but was warned that they have same thing like yours but they work fine in the amp they tested them with. I also read that such thing sometimes happens but still should cause no problems


 
  
 Thanks. I have my fingers crossed. The 5998 is getting harder and harder to acquire and accordingly more expensive.


----------



## MoatsArt

In my opinion the Tung Sol 7236 is a great alternative to the 5998. While it's harder to find, it is also usually more affordable. To be honest, I prefer it to the 5998 and the GEC 6AS7G brown base (but that doesn't stop me from owning all three )

http://the-key.enix.org/~krystal/review-tube-bottlehead.html


----------



## olegausany

By the way I replaced 5998 with 6H13C which isn't longer manufactured cause factory no longer exist and paired with Phillips E80CC, which also very difficult to find, and was surprised that it sounded so similar in my setup and EQ settings so no way I could distinguish in the blind test

Sent from my LG-V500 using Tapatalk


----------



## MattTCG

^^ Cool, then you'd offer to sell me the 5998.


----------



## spacequeen7

matttcg said:


> Dang, nice find!! Today I'll be setup again on my favorite chain. uberfrost>quickie>crack>650.


 
 I just ordered quickie with upgrade ..can't wait


----------



## MattTCG

That's great!! Can't wait to hear what you think.


----------



## bigfatpaulie

matttcg said:


> That's great!! Can't wait to hear what you think.


 
  
 I can't wait to hear if you end up with LCD2's or HD800's!


----------



## olegausany

LCD2 will not pair well with Crack. I heard LCD2 with moded sEX i still have as well as speakers taps of CEC HD53n Japanese amp and they sounded really way better than PM-1 i heard on the SEX.
Since Matt going to have moded Crack HD800 is the way to go 

Sent from my LG-V500 using Tapatalk


----------



## grrraymond

GEC Brown Base impressions:
  
 From 45 minutes' listening, at 6am, this is a gorgeous thing. It's warmer and richer - tubier, even - than the 5998 but the detail is all there. It seems to bring the focus back to the mids, which really suits the HD650s. Also, the bass thumps like the stock Crack with a Mullard 6080 but with the extension and tightness of...well, there's no comparison with anything I've heard.
  
 I've got to get to work now but looking forward to some extended listening this evening.
  
 Edit: For example, Aphex Twin - Flim. There's a whole other level of richness to the synth decay which has never come through before. Boards of Canada...crikey.


----------



## Sonido

The Smash DHT really needs to ship soon. The Quickie has set a high bar. Can't wait to see how the Smash is with the Crack.


----------



## Aeolus Kratos

sonido said:


> The Smash DHT really needs to ship soon. The Quickie has set a high bar. Can't wait to see how the Smash is with the Crack.


 





  
 Can't wait for your impressions


----------



## MoatsArt

Have just joined the modders' club.

I have added a switch onto the speedball that lets me select between different current outputs, resulting in a nice operating point for 12AU7, E80CC and 12BH7. Currently I have a Tungsram E80CC up front. With the 7236 the sound is a little harsh and forced. However, it balances beautifully with the GEC 6AS7G curved brown bass. I highly recommend this combination.


----------



## JamieMcC

moatsart said:


> Have just joined the modders' club.
> 
> I have added a switch onto the speedball that lets me select between different current outputs, resulting in a nice operating point for 12AU7, E80CC and 12BH7. Currently I have a Tungsram E80CC up front. With the 7236 the sound is a little harsh and forced. However, it balances beautifully with the GEC 6AS7G curved brown bass. I highly recommend this combination.


 
  
 Nathan the E80cc and GEC 6as7g is my favourite combination. I like what I'm hearing running the same combo now with those Epcos pio motor runs
  
 I have tried four different PIO caps with the Crack so far and liked them all! I have some 100uf Solen films on the way also to try.


----------



## MattTCG

+1 on the Solen film caps. I got very good results with them. You should like them I would think.


----------



## JamieMcC

Swapped out the Hovlands Supercap bypasses to try for some Russian K71-7 Polystyrenes.


----------



## ffivaz

grizzlybeast said:


> *is there supposed to be buzzing/humming at low levels with my crack/speedball?*
> 
> If not what could be the problems. I had this with other amps and know its common but its a little bit louder on the crack/speedball.
> 
> I am thinking its the kind of tube I am using "*RCA 6AS7G JAN Black Plates"*. The stock 6080 did this even worse.


 
  
 Could it be source related if you had it with previous amps? I would try to run the Crack without any source connected and using a shorting plug (a RCA jack with an around 500 Ohms resistor connecting ground to center). If it's dead quiet with a shorting plug, then it's your source (without shorting plugs and no source, there should or could be some humming). If it's not quiet, then I would try to move the Crack around, remove RFI source around and finally ask help at Bottlehead forum.


----------



## JamieMcC

Time for some humble pie, about 6 months ago I tried bypassing my JFX films with the Jantzen Audio Superior Z-Cap and really didn't like the results very much.  Well I tried them earlier with the Epcos 100uf's and the effect was completely different with the pio caps the results was a great success the complete opposite of my earlier trials with the JFX.
  

  
 Thought I would include a picture of some different construction types of film capacitor as its a chance to see how the sizes compare
  
 Top in black a standard JFX 2.2uf film it has the largest capacitance of the three
  
 Middle  Jantzen Audio Superior Z-Cap 0.47 uf these have the windings interweaved so effectively it takes two normal 0.47 winding to make one Jantzen Superior Z-cap
  
 Bottom and largest physical size the Hovland Supercap 1uf these are constructed using the true film method so a winding of real metal foil is used in between layers of film rather than the just the normal thin metalized polypropylene film .


----------



## grrraymond

Ok, my assessment of the GEC Brown Base vs. TS 5998:
  
 These are both running, via rDAC, in a Speedball + Crack, with 100uF Mundorf output caps (only around 30hrs burn-in) and a Brimar E80CC with the resistor mod, into HD650s.
  
 The most distinctive difference, and which I can see dictating preference, is that the 5998 has a slightly drier, superficially airier presentation while the GEC offers an extremely cohesive, rich and full presentation.
  
 The 5998 does an amazing job at elevating the lead vocal/instrument and giving it its own space. It also seems to slightly lift the drum track and percussive details which give it a great sense of pace and energy. I want to air drum to pretty much everything. This lighter, airier presentation does mean that certain elements can come across as thin, including drums. Despite the level of detail, it's a very relaxing listen, you're excited by all the little flourishes but the presentation is so sweet. Bass is perfectly controlled, taut and extends deep. You can easily pick out all the bass notes and separate levels of mid/low/sub-bass. The mids also have a ton of detail and texture. There seems to be plenty of stereo movement of instruments. I absolutely love this tube in my set-up and can't say I bought the GEC for any reasons of dissatisfaction. Since I fitted the caps and gave them a little chance to burn in, this combo produced the best sounding music I've ever heard.
  
 The brown base, on the other hand, is less ostentatious with its detail. The first thing you notice is emphatically not the imaging and percussive detail, it's the relative thickness of the sound. This is probably the warmest music has been since I fitted the Speedball. As I said above, my initial response was almost akin to listening to the Mullard 6080 powering the ECC82 in the stock Crack. It's obviously a whole other level above that, but in terms of bass impact, that was my previous reference point. And initially, while that was enjoyable, it seemed like a step backwards in one sense, because I'd been enjoying that exponential increase in imaging and detail with a few recent mods I'd done. It takes a little longer to realise that all those details are there, that you can unpick the entire track piece by piece if you want, that the decay and reverb are identifiable on every neatly separated element, it's just that the tube is not encouraging you to do that. It's presenting it all together in a very rich and cohesive package. As I said above, it's brought back the lushness of the lower mids which the 5998 keeps quite airy. On the other hand, this can mean that the music washes over you, it's so soothing and buttery smooth. Whereas the 5998 continually brings you back and competes for your attention with its brilliance, the GEC allows you to sink into the whole, pure engagement, confident that all the detail is there for the taking when you want it.
  
 You listen to something like Birdland, which offers layers upon layers of rhythmic keys, glistening pads, bumping melodic bass, bright synths and delicate piano. One tube is constantly feeding you little treats and tasty morcels, the other lays out a glorious banquet and says 'serve yourself'.


----------



## JamieMcC

Graham, nice write up, I am pleased the tube made it to you safely and that your enjoying the GEC experience. 
	

	
	
		
		

		
		
	


	



  
 One of my favourite things about the GEC is how its handles vocals its just has a special way of conveying the subtleties of both male and female vocals its analytical side digs deep revealing nuances in tone and texture and can then deliver them them with either the upmost delicacy & fragility or all the gravel and rawness of a stained male rock vocal. Listening to females artists like Eva Cassidy can be spellbinding and just stop you dead in your tracks.


----------



## JamieMcC

NOS 5998's  if anyone here has been after one. 
  
http://www.ebay.co.uk/itm/Excellent-NOS-TUNG-SOL-5998-6AS7G-6080-421A-TUBE-1-piece-8-offers-/331210522779?pt=Vintage_Electronics_R2&hash=item4d1daf809b


----------



## pduk

Thanks Jamie - ordered 
	

	
	
		
		

		
		
	


	



  
 Paul.


----------



## grrraymond

I've noticed sporadically over the past couple of months that the bass is sometimes slightly imbalanced in my 650s, I wasn't sure whether it was just in my head and I actually went to get my ears tested!
  
 I'd switched cables and tried them with different sources, same problem. I thought they'd gone to the knackers yard but they'd always seem to right themselves. Anyway, this morning I've had nothing but grief from them so I took them all apart. One driver wasn't clipped in properly. Doh! Back to their best now 
  
 Feel free to disregard all my comments and analyses on here over the past six months...


----------



## JamieMcC

I have been trying out a pair Solen made 100uf films in my Crack and found them to be very similar to JFX 100uf premium films.


----------



## MattTCG

Just wanted to throw this out as an interest check. I'll possibly be producing some custom bases out of exotic types woods. Black walnut, tiger wood, birdseye maple ect. I plan to build about 10 bases and sell them here on the forums. It will be a US only sale and will be a limited run. Please pm me if you have any interest.


----------



## i luvmusic 2

matttcg said:


> Just wanted to throw this out as an interest check. I'll possibly be producing some custom bases out of exotic types woods. Black walnut, tiger wood, birdseye maple ect. I plan to build about 10 bases and sell them here on the forums. It will be a US only sale and will be a limited run. Please pm me if you have any interest.


 
 My guess is going to be a DOVE TAIL JOINT all four corners if it's custom i would do it this way.


----------



## bigfatpaulie

matttcg said:


> Just wanted to throw this out as an interest check. I'll possibly be producing some custom bases out of exotic types woods. Black walnut, tiger wood, birdseye maple ect. I plan to build about 10 bases and sell them here on the forums. It will be a US only sale and will be a limited run. Please pm me if you have any interest.


 
  
 Did you master the art of dove-tails?


----------



## i luvmusic 2

bigfatpaulie said:


> Did you master the art of dove-tails?


----------



## .Sup

I have a possibly weird question but could Crack act as a preamp for another headphone amp? 6.5mm cable into 2 XLR.


----------



## grrraymond

Asked on the BH forum.


----------



## MattTCG

bigfatpaulie said:


> Did you master the art of dove-tails?


 
  
 Did I make one base using dove tailed corners? Yes. Am I willing to make a set of 10? No. It takes several days for me to make a base with dove tailed corners. Sorry...


----------



## spacequeen7

bigfatpaulie said:


> Did you master the art of dove-tails?


 
  this guy is pretty good , love both my bases
 https://www.etsy.com/shop/DovetailsAndStitches?ref=l2-shopheader-name


----------



## Loquah

You should try being in Australia! 
	

	
	
		
		

		
			




  
 Admittedly we are fortunate with no significant import duties for single item orders (that I've experienced), but shipping costs are huge and a lot of the really great gear doesn't have full distribution (or any) here. No doubt some of our friends in parts of Asia may feel the same.


----------



## guirr

loquah said:


> You should try being in Australia!
> 
> 
> 
> ...


 
 I've heard of people that take a flight to america to buy expensive electronics since it's cheaper, LOL
  
 do you know anyone who's done it, or is that just an over exaggeration?


----------



## Brooko

loquah said:


> You should try being in Australia!
> 
> 
> 
> ...


 
  
 Kiwis are the same Loq.  I'd love to buy a Crack kit (somehow that still just sounds wrong 
	

	
	
		
		

		
		
	


	




 ) - but it's getting it here at the right price that's an issue.
  


guirr said:


> I've heard of people that take a flight to america to buy expensive electronics since it's cheaper, LOL
> do you know anyone who's done it, or is that just an over exaggeration?


 
  
 Not sure about doing that specifically - but I usually travel to Nth America and Europe annually with my job.  When I have the funds (growing family and mortgage dictates the budget), I often pick up gear in the US and bring it home rather than shopping locally.  The price difference is worth it.


----------



## Loquah

guirr said:


> I've heard of people that take a flight to america to buy expensive electronics since it's cheaper, LOL
> 
> do you know anyone who's done it, or is that just an over exaggeration?


 
  
 I do know that at last check it was cheaper to fly to the US, but a copy of Adobe Creative Suite 6 and fly home again than it was to buy the exact same product locally!?
  


brooko said:


> Kiwis are the same Loq.  I'd love to buy a Crack kit (somehow that still just sounds wrong
> 
> 
> 
> ...


 
  
 Try to arrange a group buy with 2-3 friends - it'll knock of a significant amount. Alternatively just go for it and ignore the extra dollars added by the exchange rate. Even with the extra cost, it's very, very much a good investment and still performs above the price (even in NZD / AUD)


----------



## Brooko

loquah said:


> Try to arrange a group buy with 2-3 friends - it'll knock of a significant amount. Alternatively just go for it and ignore the extra dollars added by the exchange rate. Even with the extra cost, it's very, very much a good investment and still performs above the price (even in NZD / AUD)


 
  
 I've read so much about them - and I've done my own simple recabling, so a soldering iron doesn't scare me.  Seriously thinking about ordering one when I next go over - that way I can avoid the freight (would just get it shipped to domestic address of one of my clients, and pick it up from there).
  
 Only thing holding me back so far is the fact that I own the LD MKIV (and am perfectly happy with it).  But have heard so much about the crack .........


----------



## Loquah

brooko said:


> I've read so much about them - and I've done my own simple recabling, so a soldering iron doesn't scare me.  Seriously thinking about ordering one when I next go over - that way I can avoid the freight (would just get it shipped to domestic address of one of my clients, and pick it up from there).
> 
> Only thing holding me back so far is the fact that I own the LD MKIV (and am perfectly happy with it).  But have heard so much about the crack .........


 
  
 I haven't heard the LD range of amps, but I just helped a mate build a Crack with some basic cap upgrades and it sounds seriously good with my T1s.


----------



## Brooko

Now you're talking my language 
	

	
	
		
		

		
		
	


	



  
 The two dynamic headphones I still want to trial are the T1 and HD800 .....


----------



## JamieMcC

loquah said:


> I haven't heard the LD range of amps, but I just helped a mate build a Crack with some basic cap upgrades and it sounds seriously good with my T1s.


 
  
 The effects a few upgrades can make with the Crack when listening with the T1's is quiet noticeable, well worth the effort in my view.


----------



## .Sup

A new amp from Bottlehead should be called The Bomb. When I ordered my Crack it got stuck at customs. They asked me what it is, they sounded worried like it was a kit to make a bomb. I told them its a Crack amp. Would be interesting if I said The Bomb amp.


----------



## Armaegis

Would be funnier if it were "Da Bomb"...


----------



## Loquah

Or the Dirty Bomb...
  
 "Yes sir, that's mine - it's a kit to make a dirty bomb..."


----------



## NightFlight

bigfatpaulie said:


> I really agree with this.  I think a lot of what is talked about when it comes to small differences like this are really only apparent when taking the time to savor the music; at least for me.




I would argue investing in your gear with both money and know how will provide you the option of focusing when you want to. Or, not suffer so much disappointment when you do.


----------



## JamieMcC

If anyone is UK/EU based on a budget and after a nice pair of 100uf film output caps for their Crack I have just listed two used but perfectly working 100uf 400V DC Solen film capacitors. I found them very similar sounding to the JFX premium films and as such don't require two different makes of capacitors that sound so similar in my growing pile so the Solens are now up for grabs if anyone is interested..
  
http://www.ebay.co.uk/itm/Solen-100uf-400V-DC-Film-Capacitor-x-2-/121352137226?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item1c4126aa0a


----------



## NightFlight

grrraymond said:


> GEC Brown Base impressions:
> 
> From 45 minutes' listening, at 6am, this is a gorgeous thing. It's warmer and richer - tubier, even - than the 5998 but the detail is all there. It seems to bring the focus back to the mids, which really suits the HD650s. Also, the bass thumps like the stock Crack with a Mullard 6080 but with the extension and tightness of...well, there's no comparison with anything I've heard.
> 
> ...




Now you touching down on some of my genres.. Seems the brown base is worth the price then. Can it even be found these days?


----------



## NightFlight

jamiemcc said:


> Swapped out the Hovlands Supercap bypasses to try for some Russian K71-7 Polystyrenes.




The Russians are pretty neat.


----------



## ModestMeowth

nightflight said:


> Now you touching down on some of my genres.. Seems the brown base is worth the price then. Can it even be found these days?


 
 I just got a curved brown base Osram in the mail today and holy sh!t the tube is amazing! I don't plan to ever use the 5998 ever again


----------



## skeptic

Reality check: unless you got a screamin' deal, a GEC brown base is now typically more than 1/6 the price of a mainline.  "Worth the price" is highly subjective.  I like my hotrodded crack with my GEC quite a lot.  I also quite like my 5998's, my 7802 and several of my mil spec 6080's in the power tube slot.  As good as all of these tube complements sound, none of them put the crack in the same league with the mainline (that's with hd800's, hd650's, dt880's - to say nothing of low impedance phones).
  
 For context, in the old days, when skylab reigned supreme on head-fi as the most prolific and venerated reviewer, he advocated the GEC's as the best 6as7/6080 variant.  When they climbed north of $150 a pop, he urged head-fiers _to look elsewhere.  _Not trying to crap on what is definitely a very nice tube, but for those of you who haven't picked one up, don't feel bad or like you're seriously missing out and need to sell plasma, your wife etc. to get your hands on this tube.  IMO, as a GEC owner, your money is better spent as a good chunk of a mainline, the upcoming bh dac, or some other serious gear upgrade.
  
 /FlameSuitOn!


----------



## Loquah

skeptic said:


> Reality check: unless you got a screamin' deal, a GEC brown base is now typically more than 1/6 the price of a mainline.  "Worth the price" is highly subjective.  I like my hotrodded crack with my GEC quite a lot.  I also quite like my 5998's, my 7802 and several of my mil spec 6080's in the power tube slot.  As good as all of these tube complements sound, none of them put the crack in the same league with the mainline (that's with hd800's, hd650's, dt880's - to say nothing of low impedance phones).
> 
> For context, in the old days, when skylab reigned supreme on head-fi as the most prolific and venerated reviewer, he advocated the GEC's as the best 6as7/6080 variant.  When they climbed north of $150 a pop, he urged head-fiers _to look elsewhere.  _Not trying to crap on what is definitely a very nice tube, but for those of you who haven't picked one up, don't feel bad or like you're seriously missing out and need to sell plasma, your wife etc. to get your hands on this tube.  IMO, as a GEC owner, your money is better spent as a good chunk of a mainline, the upcoming bh dac, or some other serious gear upgrade.
> 
> /FlameSuitOn!


 
  
 LOL. No need for the flame suit I think 
	

	
	
		
		

		
		
	


	



  
 I completely agree that the brown base 6AS7s are great, but they are an incremental upgrade, not a huge leap. In the Crack I recently built for a friend, I tried his Russian 5998 equivalents that he bought for about $10 each and they were marvellous. They had less warmth than a 6AS7 (probably because they are basically a 5998), but I would be completely happy with something like that and an extra $150 in my pocket to buy a nice 12AU7 / E80CC or some output caps.
  
 If money is no issue, sure, buy a brown base because they are a flat-out awesome tube, but I agree with skeptic that if you're looking to maximise bang for buck, don't worry about the brown base and save your pennies to spend on other Crack upgrades (attenuator, caps, etc.) or to buy a Mainline for the express lane to audio nirvana.


----------



## Nic Rhodes

Loquah, what is the Russian 5998 valve equivalent? I haven't heard of this before.


----------



## JamieMcC

Guess us guys in the UK are lucky as the GEC 6as7g is more common on our shores than the TS 5998 and can often be found for the same prices or less than the 5998 (a rarer tube here) goes for.  $65-$85 is not uncommon even for the curved based.


----------



## MoatsArt

Better stock pile now, gents, before these tubes are a reverent whisper or become the seed of mythology.


----------



## JamieMcC

nightflight said:


> The Russians are pretty neat.


 
  
 The effect of bypassing with the K71-7 Polystyrenes was quiet pronounced and initially I was like WOW however I soon realised the presentation was quiet fatiguing to listen to with my T1's and a hour or so was all I could handle. 
  
 They actually worked much better with HD650's and for the couple of pound they cost would be well worth a try for anyone who predominately uses the Senns.


----------



## Loquah

nic rhodes said:


> Loquah, what is the Russian 5998 valve equivalent? I haven't heard of this before.


 
  
 I don't remember the model number - I had to Google them because I wasn't sure if they were a direct equivalent or not. The tubes belonged to @atsq17 so if he's on this thread he might be able to help.


----------



## atsq17

*The description on ebay was precisely: 6AS7G Tube. Svetlana Wingged '©' 6N13S 6H13C*


----------



## atsq17

A true audio and visual treat.


----------



## MattTCG

jamiemcc said:


> Guess us guys in the UK are lucky as the GEC 6as7g is more common on our shores than the TS 5998 and can often be found for the same prices or less than the 5998 (a rarer tube here) goes for.  $65-$85 is not uncommon even for the curved based.


 
  
 I'll trade a nice TS 5998 for a 6as7g brown base.


----------



## Loquah

atsq17 said:


> A true audio and visual treat.


 
  
 So happy with how the look turned out for you! Is the Cleartop 12AU7 a good match with the 6H13 and T1s?


----------



## olegausany

Be aware that 6H13C Winged C is out of production and factory no longer exists. They really sound great and if you can't find 5998 or asking price is too high for you get 6H13C


----------



## Nic Rhodes

atsq17 said:


> *The description on ebay was precisely: 6AS7G Tube. Svetlana Wingged '©' 6N13S 6H13C*


 

 Thanks, it is a very nice tube that is still well priced


----------



## atsq17

loquah said:


> So happy with how the look turned out for you! Is the Cleartop 12AU7 a good match with the 6H13 and T1s?


 
  
 I kinda knew they were great since Mahdi had them as his combo and I tried it for a couple of days.
  
 With regards to my equipment, I haven't been doing much A-B testing. Just put the Cleartop in the moment I got home and haven't switched tubes since. I might do so soon after the initial euphoria settles down a bit.


----------



## .Sup

I just bought an RCA 6AS7G for 25$ shipped. Seems like a good deal.


----------



## Mak333

nic rhodes said:


> Thanks, it is a very nice tube that is still well priced


 

 I think so too.  A co-worker of mine let me try (and eventually have) a 6H13C, 8702 printed directly below it, and it sounds great compared to a 6AS7G and 6080 that I've tried.  The clarity is still there, but provides a nice warmer tone and I think is very well balanced throughout the lows, mids, and highs.


----------



## MoatsArt

Have just been diagnosed by a psychiatrist as having bipolar. Apparently part of my manic episodes involves the binge buying of amplifier components, including tubes. Am selling off my entirely unneeded excess of gear as seen in my signature.

Will I never learn?


----------



## JamieMcC

Nathan perhaps I should see a psychiatrist also I have similar symptoms!  
  
 Good luck with your sales.


----------



## MoatsArt

Hehe, perhaps Jamie.

Do your buying binges alternate with suicidal depression? Do you put your family in debt to buy things that you don't need or won't use? Do your buying binges occur when you are unemployed because you are too anxious to leave the house? If so, run to your nearest psychiatrist ASAP.

Lithium is to be my friend and constant companion.


----------



## mullardpassion

.sup said:


> I just bought an RCA 6AS7G for 25$ shipped. Seems like a good deal.


 

 It is..Superb tube. Grab a couple and you're good to go for years


----------



## Mahdi8

atsq17 said:


> A true audio and visual treat.




It is a beautiful looking and sounding combo. The Svetlana tube is a hidden gem can can be had arround $30 for a pair shipped. I wouldn't surprise if the price shoot up to $50 each in a year or so when stock runs out. That's why I've stocked up on them


----------



## Mahdi8

BTW atsq you should show the bottom part with all the upgraded caps


----------



## grrraymond

skeptic said:


> Reality check: unless you got a screamin' deal, a GEC brown base is now typically more than 1/6 the price of a mainline.  "Worth the price" is highly subjective.  I like my hotrodded crack with my GEC quite a lot.  I also quite like my 5998's, my 7802 and several of my mil spec 6080's in the power tube slot.  As good as all of these tube complements sound, none of them put the crack in the same league with the mainline (that's with hd800's, hd650's, dt880's - to say nothing of low impedance phones).
> 
> For context, in the old days, when skylab reigned supreme on head-fi as the most prolific and venerated reviewer, he advocated the GEC's as the best 6as7/6080 variant.  When they climbed north of $150 a pop, he urged head-fiers _to look elsewhere.  _Not trying to crap on what is definitely a very nice tube, but for those of you who haven't picked one up, don't feel bad or like you're seriously missing out and need to sell plasma, your wife etc. to get your hands on this tube.  IMO, as a GEC owner, your money is better spent as a good chunk of a mainline, the upcoming bh dac, or some other serious gear upgrade.
> 
> /FlameSuitOn!


 
  
 I wanted to give myself another couple of days of listening and comparing before a proper reply.
  
 I'm happy with what I paid for it, for the relative benefits it has brought. It cost a little less than the sum total of the Mundorf Caps, the Supreme bypass caps and the PSU film bypass cap. Having swapped those out today checking for a cold joint, I think the GEC on its own makes a bigger difference. It costs almost as much as the Speedball and I would therefore choose that above a GEC, for anyone looking to upgrade. That said, I never had the chance to listen to it in the stock Crack.
  
 The reason I'm so pleased with it is because it has completed the picture, as it were. It's all about the presentation. It brings a certain refinement to every single aspect of the sound, bass is warm and deep but tightly controlled, it's the best I've heard. The highs offer all the detail you like but with zero fatigue, they're very very sweet. This is the most satisfying treble I've heard, and this is on the HD650s. When you get to the mids, this is where the GEC, and the 650s, really shine. The presentation of vocals and of instruments and textures is absolutely pristine, neither forward nor recessed, not excessively separated nor cluttered in the slightest. It's just the ideal balance, to my ears. Again, I'll come back to the word presentation. Different tubes have given me more in various areas, but almost always to the detriment of something else. The GEC takes all these desirable ingredients and serves you a perfectly balanced meal.


----------



## .Sup

Hey guys someone here is selling SIEMENS E80CC NOS for 30€ per pair. Should I get it? Any advice welcomed.


----------



## MattTCG

Darn good tubes, if they are the real deal.


----------



## .Sup

Thanks! I sent him a PM asking him to take a photo.


----------



## JamieMcC

.sup said:


> Hey guys someone here is selling SIEMENS E80CC NOS for 30€ per pair. Should I get it? Any advice welcomed.


 

 There are a  couple of different types of Siemens E80cc so you might like to confirm which type it is with the seller, some favour the steel pin variety over the gold pin ones as they are said to more neutral and linear than gold plated pin version. The nickel plated version also appears to be identical to the Tungsram E80cc


----------



## .Sup

Thanks Jamie, I purchased it, should be here on Tuesday. I will post some pictures. The seller was very nice, he told me they have a code 877 which means made in late 70s/early 80s.

This is the image he provided (image from web but he says his are identical)


Made by Tungsram for Siemens.

Anyways for 35€ shipped for a pair I don't think I can go wrong.


----------



## JamieMcC

Nice tubes I like mine, have you seen the resistor & switch mod on the bottlehead forum for these? Its a inexpensive  modification to the speedball which helps get the best out of E80cc tube.
  
http://bottlehead.com/smf/index.php/topic,5989.30.html


----------



## i luvmusic 2

I know i don't have my CRACK Amp yet due to work away from home.I would like to know if 6DJ8 can be use for crack?Thanks!


----------



## spacequeen7

i luvmusic 2 said:


> I know i don't have my CRACK Amp yet due to work away from home.I would like to know if 6DJ8 can be use for crack?Thanks!


 
 nope


----------



## .Sup

jamiemcc said:


> Nice tubes I like mine, have you seen the resistor & switch mod on the bottlehead forum for these? Its a inexpensive  modification to the speedball which helps get the best out of E80cc tube.
> 
> http://bottlehead.com/smf/index.php/topic,5989.30.html


Thank you for the link Jamie, I have not seen it, been a while since I was browsing the BH forums. To be completely honest I don't think I have the cajones to mod my Crack just yet.


----------



## i luvmusic 2

spacequeen7 said:


> nope


 
 THANKS!


----------



## .Sup

spacequeen7 said:


> nope



I guess its not too late to ask if the tube I ordered the E80cc fits in Crack without any modifications? I think I'll be fine but it never hurts to be 100% sure.


----------



## olegausany

Fits without problems, it uses same 9 pin layout


----------



## mordicai

Installed the switch mod with 470 resistors on the speedball for the E 80cc tube. Sounds very good but I can only just crack the volume control in term of loudness. Seems that there is way too much gain. I'm not sure the best way to proceed with this. Install a Potentiometer, or use a resistor in the volume pot?  
 Any advice would be appreciated. Can't imagine how much better a Mainline would be then this Crack. It may sound different, but would it be better?   Max


----------



## JamieMcC

mordicai said:


> Installed the switch mod with 470 resistors on the speedball for the E 80cc tube. Sounds very good but I can only just crack the volume control in term of loudness. Seems that there is way too much gain. I'm not sure the best way to proceed with this. Install a Potentiometer, or use a resistor in the volume pot?
> Any advice would be appreciated. Can't imagine how much better a Mainline would be then this Crack. It may sound different, but would it be better?   Max


 
  
 From the Crack sticky notes (I used this method for a while. After fitting a stepped attenuator I found there to be better range in the volume and removed the resistors soon after). The resistors are a easy and cheap fix if you are unable to alter the your sources gain.
  
http://bottlehead.com/smf/index.php/topic,4295.0.html
  
*"3.  I can barely turn my Crack up at all before it's far too loud, what do I do?*

 Remove the white wire from the left RCA jack at the rear of the chassis.  Solder in a 270K resistor to the solder cup on that jack, solder the white wire to the other end.  Repeat this for the red wire with another 270K resistor.  This will give you about a -10dB pad at the input.  If you still have the issue, try 470K instead.  The wattage of these resistors isn't all that important, anything between 1/16 Watt and 1/2 Watt is reasonable, with metal film and carbon film types being most recommended."


----------



## MattTCG

Can someone post a couple of links to recommended resistors? 
  
 thanks...


----------



## JamieMcC

matttcg said:


> Can someone post a couple of links to recommended resistors?
> 
> thanks...


 
 ebay search for  270K resistor and you will be spoilt for choice.


----------



## Don Lehrer

atsq17 said:


> A true audio and visual treat.
> 
> 
> Spoiler: Warning: Spoiler!


 
 Me likes!!! Congrats


----------



## mordicai

jamiemcc said:


> From the Crack sticky notes (I used this method for a while. After fitting a stepped attenuator I found there to be better range in the volume and removed the resistors soon after). The resistors are a easy and cheap fix if you are unable to alter the your sources gain.
> 
> http://bottlehead.com/smf/index.php/topic,4295.0.html
> 
> ...


 
 Thanks Jamie, I'll pick up a couple tomorrow and give it a shot.


----------



## mordicai

One other question on this volume issue. My RCA's come from a Emotiva Dac1 which has a variable pre amp volume. When I reduce the input gain from the DAC the sound seems muddy.  However I assume this is the same thing as adding resistors to the RCA inputs? What will a Potentiometer do for me?


----------



## Loquah

mordicai said:


> One other question on this volume issue. My RCA's come from a Emotiva Dac1 which has a variable pre amp volume. When I reduce the input gain from the DAC the sound seems muddy.  However I assume this is the same thing as adding resistors to the RCA inputs? What will a Potentiometer do for me?


 
  
 It might be that the Emotiva removes the volume control from the circuit when it's at full volume (depending on the design). If that's the case then what you're hearing is the difference added to the sound by the Emotiva's volume control. There is no reason to expect the resistors to sound the same so it's still worth a try.
  
 Alternatively, it's possible that you're actually listening at a lower volume than you think when you drop the Emotiva volume and that will definitely reduce dynamics, etc. Try turning the Crack up a bit more and see if the sound opens up.
  
 A potentiometer is exactly what you've already installed in the Crack as the volume control. The only benefit of changing to a different potentiometer would be more transparency. Changing to a stepped attenuator, however, can provide more range of volume based on my experiences with the Dale stepped attenuator I installed in my S.E.X. amp. I assume this has something to do with the exact resistors used for each step.


----------



## mordicai

loquah said:


> It might be that the Emotiva removes the volume control from the circuit when it's at full volume (depending on the design). If that's the case then what you're hearing is the difference added to the sound by the Emotiva's volume control. There is no reason to expect the resistors to sound the same so it's still worth a try.
> 
> Alternatively, it's possible that you're actually listening at a lower volume than you think when you drop the Emotiva volume and that will definitely reduce dynamics, etc. Try turning the Crack up a bit more and see if the sound opens up.
> 
> A potentiometer is exactly what you've already installed in the Crack as the volume control. The only benefit of changing to a different potentiometer would be more transparency. Changing to a stepped attenuator, however, can provide more range of volume based on my experiences with the Dale stepped attenuator I installed in my S.E.X. amp. I assume this has something to do with the exact resistors used for each step.


 
 Thanks Loquah, I've been a-b ing using the Emotive volume control and I thinks its really o.k. I'll try some resistors tomorrow just to check


----------



## mordicai

Loquah,I believe that:
  ​

 Dale 23 Step Ladder-type Potentiometer Volume Control Log 100k Ohm Stereo you used in the sex you also used in the Crack. I that correct? It will fit with modifications in the Crack with Speedball? Thanks, Max


----------



## Loquah

mordicai said:


> Loquah,I believe that:
> ​
> 
> Dale 23 Step Ladder-type Potentiometer Volume Control Log 100k Ohm Stereo you used in the sex you also used in the Crack. I that correct? It will fit with modifications in the Crack with Speedball? Thanks, Max


 
  
 Hi Max. That's correct. The fit in the Crack is a little trickier. You need to enlarge the main hole for the volume spline slightly as well as adjusting the hole for the locking tab. In addition to that, I loosened off the the nearest Speedball board and remounted it on a slight angle to sit in the groove between the 2 rows of resistors on the attenuator with some insulating tape to ensure nothing touched where it shouldn't.
  
 There's nothing too complicated or risky - just some minor fiddles.


----------



## mordicai

Great Ill give a shot thanks


----------



## Lugnegaard

Sorry for a rookie question, but how do I post images here. When I try to use the image button, it says that my account dont have required permission?


----------



## Deterministic NL

Just for the heck of it here are the two Cracks I built.
  
 First is CrackPipe (source is a Raspberry Pi, get it?) and 2nd is KrispyCrack.  KrispyCrack is in my daughters possession.


----------



## Aeolus Kratos

lugnegaard said:


> Sorry for a rookie question, but how do I post images here. When I try to use the image button, it says that my account dont have required permission?


 

 If I remember correctly, your account must have >20 posts in order to post images on the forum, but I'm not sure


----------



## Lugnegaard

Looks cool, like some pop-art  The green chassi turned out nicely


----------



## Lugnegaard

Finished building my Crack last week, it was a real challenge but I had a lot of fun. Spent way to much time on the finishing work.
  
 I hope you like it


----------



## Lugnegaard

Sorry, forgot the mandatory wiring shot!


----------



## atraf

Beautiful nicely done, I am thinking of coloring my soon to be Crack chrome as well.. I just don't know if i should air brush it or just polished it with a dremel or something... any tips? 
 I have created several designs in sketch up, just need to pick


----------



## Loquah

Lugnegaard I have marvelled at your Crack (chuckle, chuckle) many times on the BH forum. Every detail, including the wiring, is first class. Congratulations for the incredible craftsmanship!!


----------



## jgreen16

@Lugnegaard, that is one beautiful Crack. The finishes are simply stunning!
  
 And the Crack Pipe and Krispy Crack are nicely done as well.


----------



## Mahdi8

that is gorgeous I think the best looking crack I've ever seen


----------



## Deterministic NL

lugnegaard said:


> Looks cool, like some pop-art  The green chassi turned out nicely


 
 Yeah  I was going for the art deco thing.  I also put a bottle cap on the volume control that said Krispy or Krispy Crack but can't find any photos of it.


----------



## Deterministic NL

mahdi8 said:


> that is gorgeous I think the best looking crack I've ever seen


 
 Ditto.  His Crack looks just amazing!


----------



## Aeolus Kratos

lugnegaard said:


>


 
 I'm speechless.....I've never could imagine the Crack can be such a beauty like that!


----------



## JamieMcC

loquah said:


> @Lugnegaard I have marvelled at your Crack (chuckle, chuckle) many times on the BH forum. Every detail, including the wiring, is first class. Congratulations for the incredible craftsmanship!!


 

 +1


----------



## Lugnegaard

Thank you guys, I'm really happy to hear that you like it 

Btw, I'm selling this one. Had so much fun building it, gotta do more of these. 

Pm me if you're interested. The price will be high due to material costs and the amount of time invested in the project.

Kindly,
Mike


----------



## Lugnegaard

atraf said:


> Beautiful nicely done, I am thinking of coloring my soon to be Crack chrome as well.. I just don't know if i should air brush it or just polished it with a dremel or something... any tips?
> I have created several designs in sketch up, just need to pick


 
 Are you talking about the wooden enclosure or chassi plate? I assume that you mean the plate. I've done it all by hand. Started with a 240 wet sanding paper and work my way through 320, 400, 600, 800, 1200, 1500 and finally 2000. Then I used a compound called Autosol for polishing and finally a wax for aluminium wheels. It took about 2-3 days.
 Here's some pictures:


----------



## grrraymond

That's frankly beautiful.
  
 It makes me want to start all over again. I never gave a moment's thought to the finish or the base or anything, hence my absolute trench warfare trainwreck of a device.
  
 One day I'll build another...
  
 Also, I really really liked the Pop Art styled Krispy Krack on the previous page.


----------



## mullardpassion

That is a stunning Crack..Neat and beautiful


----------



## atraf

lugnegaard said:


> Are you talking about the wooden enclosure or chassi plate? I assume that you mean the plate. I've done it all by hand. Started with a 240 wet sanding paper and work my way through 320, 400, 600, 800, 1200, 1500 and finally 2000. Then I used a compound called Autosol for polishing and finally a wax for aluminium wheels. It took about 2-3 days.
> Here's some pictures:


 
 I just saw your post in BH forum, you said you have problems with scratches, did you manage to find a solution? maybe some kind of paint to protect it?
 I have the accessibility to an air brush I wonder what will be better in the long term.
  
 About the process of sanding and polishing, sorry for my ignorance, but did you use AutoSol between every layer of sanding? or only after you reached the final 2000?


----------



## Lugnegaard

I didn't find a good solution. Long term, a high polished aluminium plate requires that you are very careful. When doing the mounting and soldering I was very very careful and worked pretty slowly with a blanket underneath. I treat my Crack with great care.
  
 I used Autsol a couple of time during the sanding process, just to make sure that I wasn't missing any scratches from the coarser paper. For example, before going to 1200 from 800, I would give it a polish with Autosol just to make sure that the 800 paper successfully had removed any marks from the 600 grit paper and that the surface was even.
 It can be wise to do this a few times, so you don't end up working your way to 2000, go into polishing and find a 800 grit scratch.
  
 After 2000 I went over the plate about 2-3 times with Autosol, about 2*2 inches at a time (in circular motions).
  
 Hope this helps.


----------



## Doc B.

The solution is a little expensive, though if you are investing that much labor it's probably worth it. You can get 2K urethane clear coat like they use on cars in a rattle can. It is really tough stuff, very glossy and very easy to apply. It's about $20 a can and once you break the inner seal to mix in the catalyst it only lasts for about 24 hours, so it's not like you can just keep the remainder of can on the shelf for another project. You can color sand and rub it out to a very high gloss. On a flat panel you could probably just flood coat it (i.e. one heavy coat) and rub it out and it would look great. You do have to wear an organic vapor type mask and some gloves when you spray it.
  
 If that's too much $ a lot less durable but equally shiny looking finish can be made with clear lacquer.


----------



## Serenitty

lugnegaard said:


> I didn't find a good solution. Long term, a high polished aluminium plate requires that you are very careful. When doing the mounting and soldering I was very very careful and worked pretty slowly with a blanket underneath. I treat my Crack with great care.
> 
> I used Autsol a couple of time during the sanding process, just to make sure that I wasn't missing any scratches from the coarser paper. For example, before going to 1200 from 800, I would give it a polish with Autosol just to make sure that the 800 paper successfully had removed any marks from the 600 grit paper and that the surface was even.
> It can be wise to do this a few times, so you don't end up working your way to 2000, go into polishing and find a 800 grit scratch.
> ...


 

 I have the same problem with the copper plate crack I built.  I can't touch the top plate or it leaves fingerprints which start to tarnish the copper.  The polish I'm using is supposed to have some silicone in it to prevent that kind of stuff, but it's not enough.


----------



## atraf

lugnegaard said:


> I didn't find a good solution. Long term, a high polished aluminium plate requires that you are very careful. When doing the mounting and soldering I was very very careful and worked pretty slowly with a blanket underneath. I treat my Crack with great care.
> 
> I used Autsol a couple of time during the sanding process, just to make sure that I wasn't missing any scratches from the coarser paper. For example, before going to 1200 from 800, I would give it a polish with Autosol just to make sure that the 800 paper successfully had removed any marks from the 600 grit paper and that the surface was even.
> It can be wise to do this a few times, so you don't end up working your way to 2000, go into polishing and find a 800 grit scratch.
> ...


 
 Thanks a lot, this info helps me a lot since I don't really have much experience with that kind of work, I guess I have some research to do before I do it on my crack.
  


doc b. said:


> The solution is a little expensive, though if you are investing that much labor it's probably worth it. You can get 2K urethane clear coat like they use on cars in a rattle can. It is really tough stuff, very glossy and very easy to apply. It's about $20 a can and once you break the inner seal to mix in the catalyst it only lasts for about 24 hours, so it's not like you can just keep the remainder of can on the shelf for another project. You can color sand and rub it out to a very high gloss. On a flat panel you could probably just flood coat it (i.e. one heavy coat) and rub it out and it would look great. You do have to wear an organic vapor type mask and some gloves when you spray it.
> 
> If that's too much $ a lot less durable but equally shiny looking finish can be made with clear lacquer.


 
 Thanks Doc, just to make sure I got it right, the 2k urethane clear coat is supposed to be sprayed just as a protective coat, after I got the wanted effect of chrome? I think i will give that a try I just hope I can find it in my country.


----------



## Lugnegaard

Just be aware of the fact that if you choose to polish you aluminium plate to a mirror finish and then spray it with a clear coat, some of that shininess will be lost. That's just how it works with aluminium and clearcoats. There's a ton to read about that very subject on car forums.


----------



## Doc B.

It does take away a bit of clarity, but how much depends a bit on how well you rub out the clear. If you don't put anything on the aluminum it will pick up fingerprints (practically from across the room!) and need to be polished frequently. On average it can end up looking worse than the clear coat. So it's a matter of deciding how much maintenance you want to do. After 20 years of dealing with them - polished, painted, powder coated, anodized, alodined, made from brass, copper, acrylic, you name it - you guys can probably see why I have chosen a low maintenance brushed finish for the stock panels.
  
 If you want to try a third approach you can get the aluminum panel polished and then chromed. Just don't bend it and it will look pretty cool.


----------



## atraf

I was wondering, besides looks is any other reason the top plate should be aluminium? can it be glass ? wood? will it effect the amp itself somehow?


----------



## Doc B.

It functions as a ground plane. So alternatives would best be another conductive material - copper, etc. You could try something else and I would guarantee that I absolutely can't guarantee how it would perform.


----------



## Armaegis

While my own polish jobs weren't quite as spiffy, I did protect them while working with some painter's tape. Removing a few tape smudges is much easier than trying to buff out scratches...


----------



## atraf

Thanks guys


----------



## spacequeen7

lugnegaard said:


> Are you talking about the wooden enclosure or chassi plate? I assume that you mean the plate. I've done it all by hand. Started with a 240 wet sanding paper and work my way through 320, 400, 600, 800, 1200, 1500 and finally 2000. Then I used a compound called Autosol for polishing and finally a wax for aluminium wheels. It took about 2-3 days.
> Here's some pictures:


 
 very nice ..thanks for the inspiration .I don't like to paint the top plate since naked aluminium provides good way to dissipate the heat . I will do similar plate on my Quickie once I receive it (it takes sooo long for the unit to arrive..)


----------



## MattTCG

Question for the builders here, both the Octal and mini tube sockets seem to have a good bit of "give" to them when rolling tubes and in of the crack. Should this be the case? Is it possibly the retaining nut has come loose?
  
 thanks...


----------



## bigfatpaulie

Are you referring to the sockets in the amp and they are lose in the holes in the top plate or that actual tubes aren't fitting snugly in the sockets?  If it's the first one, you need to tighten the screws because they should be completely immobile.  If it's the latter, sounds like the little clips in sockets have bent from tube tolling.  You can bend them back (gently!).


----------



## .Sup

I just got a RCA 6AS7G power tube and I get a (very slight) tinnitus like sound in the left channel. I tried different output tubes with same result. The tube was pretty cheap at 12$ + shipping. I probably won't get a flawless tube for that much money. Its very slight and I don't hear it when music plays but before I had zero noise and so it annoys me anyway. Any recommendations?


----------



## dante020

.sup said:


> I just got a RCA 6AS7G power tube and I get a (very slight) tinnitus like sound in the left channel. I tried different output tubes with same result. The tube was pretty cheap at 12$ + shipping. I probably won't get a flawless tube for that much money. Its very slight and I don't hear it when music plays but before I had zero noise and so it annoys me anyway. Any recommendations?


 
 Try cleaning the pins on the tube, it fixes noise issues surprisingly often. Most people will recommend an electrical contact cleaner such as Deoxit (it's worth it if you're going to be buying more tubes) but a high concentration rubbing alcohol or some fine steel wool could work in a pinch.


----------



## FlySweep

If you're in the CONUS and are interested in the (hard to find) Bendix 6080WB w/ "slotted, graphite plates".. I anticipate putting mine up for sale soon.. thought I'd give the folks here a heads up first.  It's noise and microphonic free.. and rarely used, btw
 .


----------



## Loquah

flysweep said:


> If you're in the CONUS and are interested in the (hard to find) Bendix 6080WB w/ "slotted, graphite plates".. I anticipate putting mine up for sale soon.. thought I'd give the folks here a heads up first.  It's noise and microphonic free.. and rarely used, btw
> .


 
  
 Nice tube!


----------



## FlySweep

It's a beauty, isn't it Loquah?  I love the rugged build.. and the glow means business!  Oh, it sounds pretty damn good, too.. haha


----------



## MoatsArt

Selling a NOS NIB pair of Tung Sol Chatham 2399 tubes (similar to 5998) and NOS NIB pair of Tung Sol 6520 tubes listed as part of my tube sale. Thought some of you guys might be interested. Will sell as pair or singles. Recently purchased from Skylab. Arrived today, but I can't keep them (going SS).

Cheers

Nathan


----------



## networkn

Hi I have beyerdynamic t1 and hd650 and was after a good dac to go with it. What is the sweet spot for budget for a dac given diminishing returns etc? Is there a percentage of the amp spend I should be using as a guideline?


----------



## atsq17

http://www.audio-gd.com/Pro/dac/NFB32014/NFB32014EN.htm

I think this is excellent value for money. Not to be confused with lower end models or older nfb 3 that were cut down nfb 2 units with Wolfson chipsets. This unit looks like the best value implementation of ess Sabre 9018 if you don't need balanced out. Seeing as this is a crack forum and you want value. I think this takes the cake. If you are after a slightly warmer signature the nfb2 is a good implementation of the Wolfson chipset. Again I am talking about the new 2014 units although in the case of the nfb2, the old ones were good for their time.


----------



## ben_r_

networkn said:


> Hi I have beyerdynamic t1 and hd650 and was after a good dac to go with it. What is the sweet spot for budget for a dac given diminishing returns etc? Is there a percentage of the amp spend I should be using as a guideline?


 

 Whats the most you want to spend?


----------



## networkn

ben_r_ said:


> Whats the most you want to spend?


 
  
 Well I am not really sure. I don't want to go crazy. I presume in terms of budget you would spend most on the Headphones themselves, then less on the Amp, and less again on the DAC. Is $350USD reasonable? I can buy a DACMagic Plus for about $450USD here locally.


----------



## networkn

atsq17 said:


> http://www.audio-gd.com/Pro/dac/NFB32014/NFB32014EN.htm
> 
> I think this is excellent value for money. Not to be confused with lower end models or older nfb 3 that were cut down nfb 2 units with Wolfson chipsets. This unit looks like the best value implementation of ess Sabre 9018 if you don't need balanced out. Seeing as this is a crack forum and you want value. I think this takes the cake. If you are after a slightly warmer signature the nfb2 is a good implementation of the Wolfson chipset. Again I am talking about the new 2014 units although in the case of the nfb2, the old ones were good for their time.


 
  
 The issue with this, is I can't get it locally, which means buying it for $500USD and then shipping, taxes, exchange rates, I could easily see this at $800 which seems overkill for my gear?


----------



## ramaka

networkn said:


> Well I am not really sure. I don't want to go crazy. I presume in terms of budget you would spend most on the Headphones themselves, then less on the Amp, and less again on the DAC. Is $350USD reasonable? I can buy a DACMagic Plus for about $450USD here locally.


 
 I recently traded a can for Maverick Audio D2 DAC and have been very happy with how it pairs with the Crack and T1/HD 650/ HE 400. Maybe you could research on this if interested.


----------



## atraf

Regarding his question about a dac? what do you say on Musical Fidelity V90 DAC? anyone have experience with it ? how does it compare to TubeMagic D2?


----------



## networkn

I guess one question I have specifically, is finding an appropriate "size" DAC so that I don't have a DAC which won't display it's potential because of the other bottlenecks in the system. I don't mind a little headroom, because I might end up higher end AMP than the crack, but in terms of end game, the T1's are as high as I'd likely be able to justify.


----------



## bigfatpaulie

networkn said:


> Hi I have beyerdynamic t1 and hd650 and was after a good dac to go with it. What is the sweet spot for budget for a dac given diminishing returns etc? Is there a percentage of the amp spend I should be using as a guideline?


 
  
 I personally feel that different DAC's have less of an impact with the Crack.  I think that the Crack imparts so much of it's own flavor that the DAC ends up playing a small part.  I've had great experience with Audio-GD and my NFB-12.1 with the Crack.  If it were me, I would go for something like the NFB-15 (of their current stuff) and save the money/get music.  The nice thing about that is that you also get a pretty decent solid state option.  Just my 2 cents.


----------



## snapple10

Crack with Grado PS 500- sounds good to me  
	

	
	
		
		

		
			




 and fun too


----------



## MoatsArt

OK. Wow. What power tube are you using?


----------



## snapple10

unplanned Grado combo wins in fun factor
 1980's Rock on deck


----------



## networkn

I opted for a BiFrost Gen 1 with USB, because I could get it locally, because I could get it today, for a reasonable price and because it reviews well.


----------



## Aeolus Kratos

snapple10 said:


> unplanned Grado combo wins in fun factor
> 1980's Rock on deck


 
 Have you heard Tungsol 5998s, GEC 6AS7G Brown Base or Bendix 6080WB? If you have, how would you compare these tubes?
  
 I've always been curious and wanted to try the WE 421A someday, although I'm having all the power tubes mentioned above.


----------



## Loquah

bigfatpaulie said:


> I personally feel that different DAC's have less of an impact with the Crack.  I think that the Crack imparts so much of it's own flavor that the DAC ends up playing a small part.  I've had great experience with Audio-GD and my NFB-12.1 with the Crack.  If it were me, I would go for something like the NFB-15 (of their current stuff) and save the money/get music.  The nice thing about that is that you also get a pretty decent solid state option.  Just my 2 cents.


 
  
 I would have said the same until I upgraded my Audio-gd NFB-5.2 for the Matrix X-Sabre. The difference was significant, even with a stock Speedballed Crack.


----------



## Mahdi8

Yes I agree changing DAC makes a big difference to crack. For me crack with the Svetlana power tube and rca clear top is really transparent and easily shows difference between different DACs


----------



## mordicai

My change from Fiio Dacs to an Emotiva was a significant change in SQ. Speedball ,Dacs ,tubes, resistor changes all impacted the Crack sound.


----------



## olegausany

+1 on X-Sabre which easily could be end game DAC


----------



## Deterministic NL

Nice 421A in the posts just above.   Just got mine yesterday after years of trying to score one. 
  
 It's great.  A step up for sure.


----------



## kozmos

lugnegaard said:


> Finished building my Crack last week, it was a real challenge but I had a lot of fun. Spent way to much time on the finishing work.
> 
> I hope you like it


 
  
  
 man what a masterpiece, i have some hard wax i used for my rims, i think im gonna try it on my crack, i don't know if wax is the right word to use because im a swede but you get my point


----------



## kothganesh

Just got my Crack+Speedball done yesterday. Compared to the picture above, mine looks pedestrian. First thing to do on Monday is to look for some cedar finish paint!
I replaced the stock tubes with the Tungsol 5998 and the RCA 12AU7. The HD 650 has really opened up. It's the 800's turn today


----------



## punit

kothganesh said:


> Just got my Crack+Speedball done yesterday. Compared to the picture above, mine looks pedestrian. First thing to do on Monday is to look for some cedar finish paint!
> I replaced the stock tubes with the Tungsol 5998 and the RCA 12AU7. The HD 650 has really opened up. It's the 800's turn today


 

 Ganesh, As your tubes & amp are new give them at least 50 hrs of burn in. Sound will open up even more. You can take the wood base to a carpeneter  & get a nice shade of varnish / polish done dirt cheap. Some of the benefits of living in India. 
	

	
	
		
		

		
		
	


	




 
  
 As you also have the Zana D, please can you do a comparison between the two after you have gotten familiar with the Crack.


----------



## punit

Also if you feel your wallet is a bit heavy, you will find some nice rolling options in this thread to lighten the load.


----------



## kothganesh

punit said:


> Also if you feel your wallet is a bit heavy, you will find some nice rolling options in this thread to lighten the load.


 
 You're plain bad man ! 
	

	
	
		
		

		
		
	


	




. I have been listening to the HD 800. The volume dial is just south of 9 and the soundstage and detail, wooh !


----------



## kothganesh

punit said:


> Ganesh, As your tubes & amp are new give them at least 50 hrs of burn in. Sound will open up even more. You can take the wood base to a carpeneter  & get a nice shade of varnish / polish done dirt cheap. Some of the benefits of living in India.
> 
> 
> 
> ...


 
 Very very initial impressions between the Crack and the ZD on the 800. The ZD goes deeper on the bottom end. But this is not fair. I've had the ZD for months now and the Crack is literally 1 hour old !


----------



## punit

I would be surprised if the ZD doesn't outperform the Crack (like my WA22). But  what surprised me is that how an amp 1/3 the cost of  WA22 (& ZD) can get you upto 85 - 90 % (IMHO) of that performance (for high impd HP's).


----------



## MattTCG

kothganesh said:


> Very very initial impressions between the Crack and the ZD on the 800. The ZD goes deeper on the bottom end. But this is not fair. I've had the ZD for months now and the Crack is literally 1 hour old !


 
  
 I'm interested in hearing more of what you think of the crack and hd800.


----------



## punit

matttcg said:


> I'm interested in hearing more of what you think of the crack and hd800.


 

 It is a superb pairing IMHO. Are you looking for any particular quality or trait  with regards to this pairing ?


----------



## MattTCG

^^ How does the crack do with the treble and bass for the hd800 relatively compared to other/more expensive amps? Is it enough to bring out the best qualities of the hd800 and make it enjoyable?


----------



## .Sup

matttcg said:


> ^^ How does the crack do with the treble and bass for the hd800 relatively compared to other/more expensive amps? Is it enough to bring out the best qualities of the hd800 and make it enjoyable?



In my opinion it does what you'd want from a tube amp for HD800 - with a proper tube treble is tamed down a bit without any loss of detail and bass gets fuller, less thin. Very enjoyable.


----------



## MattTCG

Hm...very interesting.
  
 thanks...


----------



## whirlwind

kozmos said:


> man what a masterpiece, i have some hard wax i used for my rims, i think im gonna try it on my crack, i don't know if wax is the right word to use because im a swede but you get my point


 
 That is absolutely beautiful  
	

	
	
		
		

		
			




  


matttcg said:


> ^^ How does the crack do with the treble and bass for the hd800 relatively compared to other/more expensive amps? Is it enough to bring out the best qualities of the hd800 and make it enjoyable?


 
 The Mad does a nice job....I would imagine the BHC should do very well as it powers the 650 perfectly...correct?


----------



## MattTCG

whirlwind said:


> That is absolutely beautiful
> 
> 
> 
> ...


 
  
 Perfectly? Absolutely.


----------



## Aeolus Kratos

matttcg said:


> I'm interested in hearing more of what you think of the crack and hd800.


 

  
 Hmmmmm, actually I found the Crack does a great job driving the HD800, but I still found it a bit harsh and kind of 'boring' sometimes compared with the T1+Crack combo. The T1 sounds more enjoyable with the Crack IMHO.


----------



## punit

matttcg said:


> ^^ How does the crack do with the treble and bass for the hd800 relatively compared to other/more expensive amps? Is it enough to bring out the best qualities of the hd800 and make it enjoyable?


 

 For me the Crack addresses the main issue that plague most ill matched HD 800 - amp combinations i.e. leanness , sharp treble & anemic base. It gives  full mids, smooth treble with adequate extension & good bass. Very Musical.


aeolus kratos said:


> Hmmmmm, actually I found the Crack does a great job driving the HD800, but I still found it a bit harsh and kind of 'boring' sometimes compared with the T1+Crack combo. The T1 sounds more enjoyable with the Crack IMHO.


 
 I actually prefer the HD 800 more  than the T1 on the Crack.


----------



## olegausany

.sup said:


> matttcg said:
> 
> 
> > ^^ How does the crack do with the treble and bass for the hd800 relatively compared to other/more expensive amps? Is it enough to bring out the best qualities of the hd800 and make it enjoyable?
> ...



+1


----------



## cheneric

How bad is it to use the E80CC on a non-speedball crack?


----------



## Loquah

cheneric said:


> How bad is it to use the E80CC on a non-speedball crack?


 
  
 It's not recommended, but I believe it's more about the potential loss of sound quality due to the E80CC not receiving correct voltages, etc. rather than a risk of damaging the tube or the amp.


----------



## Mahdi8

I also prefer HD800 to T1 in crack for my music taste. the sounstage and instrument separation of HD800 is just out of this world to me. Paired with Audio GD PCM 1074UK dac it's definitely really2 good. Mids are clear and centered. bass is detailed (with less punch compared to T1) and high is smooth and extended. Compared to T1 the obvious strength of T1 would be better bass body and definition similar quality on the mids and even smoother treble. But the biggest issue for me soundstage on T1 is significantly smaller than HD800. the difference in sound stage is quite night and day


----------



## DutchGFX

The T1 is more enjotable than the HD800 for everything "involving". The HD800 may be the superior headphone technically, and may even be more refined, but the T1 does a much better job with aggressiveness and impact I think. 

I use the Crack with Bendix 6080 and some RCA Clear Tops and I really enjoy it with the T1. I sold the HD800 (which I owned at the same time as the t1) because I much preferred the T1. I also like the Crack more than my DIY Ventus EZ and the Burson Soloist with the T1. I haven't heard the T1 on any other OTL's though, despite attending a few meets.

I'm working on an OTL amp from headwize now, and have designed my own OTL using a 6SN7, 2A3, and a 6080 Cathode follower, so I'm looking to build that next to compare to the Crack. I can post my schematic if you guys want to see, I'm interested in feedback since its my first design. 

Anyways, that's just my $.02, that the T1 is better than the HD800 for most upbeat, engaging music.


----------



## kothganesh

matttcg said:


> I'm interested in hearing more of what you think of the crack and hd800.


 
 Hi Matt:
  
 How's the golf ? 
	

	
	
		
		

		
		
	


	




. I spent an hour and a half with the Crack and the HD 800. Please note that my Crack is about 3 hours old by way of use. I thought the overall sound was elevated. Don't know how to say this but the bass is still not reaching the deeper extensions that my Zana Deux is achieving. In addition, I noticed the noise floor between songs which I don't have on the ZD. I have moved the Crack to a place where I believe it will be relatively free of noise due to other equipment.
  
 Interestingly, I found the HD 650 to be a much better pairing from the get-go with the Crack. I am going to persist with my Crack and 800 pairing and see where it takes me.


----------



## JamieMcC

kothganesh said:


> Hi Matt:
> 
> How's the golf ?
> 
> ...


 
  
 Fitting a choke and replacing the last electrolytic capacitor with a film capacitor makes a nice improvement to bass extension.


----------



## punit

(double post deleted)


----------



## punit

kothganesh said:


> In addition, I noticed the noise floor between songs which I don't have on the ZD. I have moved the Crack to a place where I believe it will be relatively free of noise due to other equipment.
> Interestingly, I found the HD 650 to be a much better pairing from the get-go with the Crack. I am going to persist with my Crack and 800 pairing and see where it takes me.


 
 I had zero noise floor with Crack - HD 800 pairing. Can you try using a diff source / tube and check.Also I had a tube which initially had noise but it went away after some burn in.


----------



## kothganesh

jamiemcc said:


> Fitting a choke and replacing the last electrolytic capacitor with a film capacitor makes a nice improvement to bass extension. :wink_face:



Great to know. Where do I get the choke and the film capacitor? I live in India and am told better off importing these items. Thanks.


----------



## MoatsArt

I have a suitable capacitor and choke. Send me a PM if you are interested.


----------



## kothganesh

moatsart said:


> I have a suitable capacitor and choke. Send me a PM if you are interested.




Thanks. You've got a PM


----------



## kothganesh

punit said:


> I had zero noise floor with Crack - HD 800 pairing. Can you try using a diff source / tube and check.Also I had a tube which initially had noise but it went away after some burn in.



I plan to continue with the current set up. May be the burn-on will take care of it. I will keep you posted. Thanks.


----------



## punit

Do you get noise from the stock tubes as well?


----------



## guildenstern

palmfish said:


> Phew!
> 
> Hey, quick question... I'm browsing online and found this "illuminated rocker switch." It's rated 15 amp instead of 5 amps at 120 VAC. I have no idea what other specs (contact resistance?) the stock switch is rated at.
> 
> ...


 

 Did you ever end up trying to install the illuminated switch (identified in your link above)? If so, did it fit in the standard switch's existing cutout opening? And was wiring straightforward? I'd really like to have an illuminated switch to help me not forget to turn the amp off. (Please, no mocking replies from youngsters -- meaning anyone under 60. There comes a time when one appreciates all the reminders one can get!)


----------



## palmfish

guildenstern said:


> Did you ever end up trying to install the illuminated switch (identified in your link above)? If so, did it fit in the standard switch's existing cutout opening? And was wiring straightforward? I'd really like to have an illuminated switch to help me not forget to turn the amp off. (Please, no mocking replies from youngsters -- meaning anyone under 60. There comes a time when one appreciates all the reminders one can get!)




Yes. It fit perfectly and was fairly straightforward to wire.


----------



## Loquah

palmfish said:


> Yes. It fit perfectly and was fairly straightforward to wire.


 
  
 Did it introduce any noticeable noise as I believe that's why there is no "on" lamp included in the kit.


----------



## Doc B.

There are "on" lamps in every kit.


----------



## Keithpgdrb

doc b. said:


> There are "on" lamps in every kit.


 
 I was thinking that.. glad you said it.


----------



## DutchGFX

Oooooo need some ice for that burn there Loquah? Haha


----------



## bdr529

I just modified mine for the 12bh7a per this thread http://bottlehead.com/smf/index.php/topic,5989.0.html. Previously I had replaced the LEDs in the socket for resisters, but my voltages were kind of high. Now it is running @70/68 V using a 147 Ohm resister. Maybe could go a little lower, but it is close to the ideal 75. I also switched in the MJE-5731A power transistors just in case. Seems to be running good!

I ended up buying 20 of each resister and MJE-5731A on ebay. The resisters were only a few bucks but shipping for the transistors was dumb. Would you buy 2 for 9 dollars, or 20 for 20... Yeah, so if anybody wants the 12bh7a mod components I have some extra haha. I will just send them at cost for a few bucks.


----------



## Loquah

dutchgfx said:


> Oooooo need some ice for that burn there Loquah? Haha


 
  
 Thanks Dutch, and thanks Doc - I thought we were friends!!


----------



## MattTCG

Your own profile pic even seems to be laughing at that one.


----------



## JamieMcC

Is the BH forum down or is it just me?


----------



## MattTCG

It's down...


----------



## grrraymond

Yup. I just went on to try to figure out why my left channel has been replaced by crackling and tearing but it's down.
  
 Fingers crossed it's a momentary thing.


----------



## Doc B.

Yes, the site is down. We are working the problem.


----------



## grrraymond

Thanks, Doc.
  
 Me too, an LED had come loose at the 9-pin socket.


----------



## Doc B.

For those of you champing at the bit, our site is back up.


----------



## liamstrain

doc b. said:


> For those of you champing at the bit, our site is back up.




Yay! And kudos on getting champing right... Most people use chomping, and do so incorrectly.


----------



## MattTCG

I'm thinking of upgrading to the gungnir dac. Anyone care to comment who have the crack paired with the gungnir and hd650?


----------



## Zashoomin

matttcg said:


> I'm thinking of upgrading to the gungnir dac. Anyone care to comment who have the crack paired with the gungnir and hd650?


 
 I personally don't think that the gungnir lives up to the hype that everyone gives it.  I think for that price there are many better options.  I suggest you look at a resonessece labs concero or a yulong offering or an Audio-GD one.  I know the second 2 are chinese but do not be decieved...they sound fantastic.  I highly suggest the concero though.


----------



## MattTCG

Thank you sir!! Checking them out now.


----------



## mordicai

Six months now with Emotiva Dac1>Crack>HD 600. I'm very happy with the sound and the versatility of this DAC. 30 day no questions return policy. Best why to know is to try it yourself rather then go on someone else's ears.


----------



## spacequeen7

...it's like listening to Crack for the first time ,but better ....loving my new Quickie 
	

	
	
		
		

		
		
	


	



 the detail ,sparkle and soundstage  are amazing and that's on stock tubes (2x Mullard waiting ),very happy with this


----------



## Loquah

spacequeen7 said:


> ...it's like listening to Crack for the first time ,but better ....loving my new Quickie
> 
> 
> 
> ...


 
  
 That Quickie looks amazing - so much more than the $99 asking price! Nice work!!


----------



## bigfatpaulie

spacequeen7 said:


> ...it's like listening to Crack for the first time ,but better ....loving my new Quickie
> 
> 
> 
> ...


 
  
 Wow.  Those are some amazing bases!


----------



## Doc B.

liamstrain said:


> Yay! And kudos on getting champing right... Most people use chomping, and do so incorrectly.




I am champing at the bit in joy that you didn't say kudus.

The havoc is not quite over. We will be doing some maintenance on the site this evening. Nothing too serious, just a 10K mile service.


----------



## kothganesh

punit said:


> I had zero noise floor with Crack - HD 800 pairing. Can you try using a diff source / tube and check.Also I had a tube which initially had noise but it went away after some burn in.


 
 I used the Bifrost Uber with the Crack/HD 800. No noise at all. This is my office set-up. Sounding great. Thanks for the advice.


----------



## JamieMcC

I will also add my amp runs silent and as I had never soldered prior and considering a poor solder connection one of the prime suspects for this. I'm firmly of the opinion that the cardas eutectic solder I used was beneficial in achieving better solder joints than I might have been able to with the standard 60/40 with my first build.


----------



## i luvmusic 2

Hi i'am about to order the Crack and my question is,Does the Speedball make a big defference in sound? I will be using the Crack to drive my Q701 and DT880 600 ohms.Thank You!


----------



## bigfatpaulie

i luvmusic 2 said:


> Hi i'am about to order the Crack and my question is,*Does the Speedball make a big defference in sound*? I will be using the Crack to drive my Q701 and DT880 600 ohms.Thank You!


 
  
 Yes.


----------



## irishsammy

i luvmusic 2 said:


> Hi i'am about to order the Crack and my question is,Does the Speedball make a big defference in sound? I will be using the Crack to drive my Q701 and DT880 600 ohms.Thank You!


 

 I don't have the Speedball so I can't answer that question but...isn't the Q701 going to be a big impedance mismatch?


----------



## bigfatpaulie

irishsammy said:


> I don't have the Speedball so I can't answer that question but...isn't the Q701 going to be a big impedance mismatch?


 
  
 Yes.


----------



## i luvmusic 2

I just purchased the CRACK with SB sorry for my wallet tho.........


----------



## i luvmusic 2

bigfatpaulie said:


> Yes.


 
 Thank You!


----------



## i luvmusic 2

What is the next important upgrade for the Crack?
 I would like to order them now while i'am waiting for the Crack and SB.Thanks!


----------



## Loquah

i luvmusic 2 said:


> What is the next important upgrade for the Crack?
> I would like to order them now while i'am waiting for the Crack and SB.Thanks!


 
  
 A nice potentiometer or attenuator makes a big difference. Other than that, it'd be better caps and connectors (RCAs and HP jack)


----------



## MattTCG

i luvmusic 2 said:


> What is the next important upgrade for the Crack?
> I would like to order them now while i'am waiting for the Crack and SB.Thanks!


 
  
 The TS5998 makes for a huge improvement IMO. And the Quickie is just huge if you want to hear some real sub bass on the hd6x00.


----------



## Doc B.

loquah said:


> A nice potentiometer or attenuator makes a big difference. Other than that, it'd be better caps and connectors (RCAs and HP jack)


 
 Yeah I would agree that upgrading the attenuator would probably be the most rewarding upgrade after the Speedball. In order to address that we are working on the idea of using a Submissive passive attenuator ahead of the Crack and replacing the stock pot in the Crack with an adjustable crossfeed circuit that can be defeated for those who don't want it in the signal path. We found that designing our own attenuator gave us the best results vs. using other available high end attenuators, and the best sounding stepped attenuators tend to be bigger than the Crack chassis can accomodate. So the Submissive in its own chassis that matches the Crack chassis may have some appeal to those who have the space for a second chassis in their setup.
  
 We will be running some tests on a crossfeed circuit in the next few weeks.
  
 Oh, and thanks for the order!


----------



## i luvmusic 2

doc b. said:


> Yeah I would agree that upgrading the attenuator would probably be the most rewarding upgrade after the Speedball. In order to address that we are working on the idea of using a Submissive passive attenuator ahead of the Crack and replacing the stock pot in the Crack with an adjustable crossfeed circuit that can be defeated for those who don't want it in the signal path. We found that designing our own attenuator gave us the best results vs. using other available high end attenuators, and the best sounding stepped attenuators tend to be bigger than the Crack chassis can accomodate. So the Submissive in its own chassis that matches the Crack chassis may have some appeal to those who have the space for a second chassis in their setup.
> 
> We will be running some tests on a crossfeed circuit in the next few weeks.
> 
> Oh, and thanks for the order!


 
 I'am interested on that keep us updated i can't wait for my KIT.Thanks!


----------



## i luvmusic 2

loquah said:


> A nice potentiometer or attenuator makes a big difference. Other than that, it'd be better caps and connectors (RCAs and HP jack)


 
 I was looking at some of those attenuator so many options with defferent price range.Thanks!


----------



## Loquah

i luvmusic 2 said:


> I was looking at some of those attenuator so many options with defferent price range.Thanks!


 
  
 The Dale stepped attenuators are good value for money - I've used one in my S.E.X. and it sounds great!


----------



## i luvmusic 2

loquah said:


> The Dale stepped attenuators are good value for money - I've used one in my S.E.X. and it sounds great!


 
 Can you please provide a link too many ebay seller to choose from i'd rather get them where you got yours.Thank You!


----------



## kothganesh

bigfatpaulie said:


> Yes.



+1.


----------



## Aeolus Kratos

http://www.ebay.com/itm/GEC-6AS7G-A1834-ECC230-pair-double-triode-thick-getter-audio-tubes-tested-/301214265739?pt=UK_Sound_Vision_Valves_Vacuum_Tubes&hash=item4621c4f18b
  
 A pair of the legendary GEC 6AS7G tubes is on sale for a very reasonable price. Not sure how they are cheap like that but I think this is a good chance for anyone who wanted to have a chance try these wonderful tubes.


----------



## Loquah

i luvmusic 2 said:


> Can you please provide a link too many ebay seller to choose from i'd rather get them where you got yours.Thank You!


 
  
 Pretty sure this is the one:
  
 http://www.ebay.com.au/itm/Assembled-Dale-23-Step-Attenuator-Volume-Control-100k-/270311271326?pt=US_Amplifier_Parts_Components&hash=item3eefceab9e


----------



## .Sup

doc b. said:


> Yeah I would agree that upgrading the attenuator would probably be the most rewarding upgrade after the Speedball. In order to address that we are working on the idea of using a Submissive passive attenuator ahead of the Crack and replacing the stock pot in the Crack with an adjustable crossfeed circuit that can be defeated for those who don't want it in the signal path. We found that designing our own attenuator gave us the best results vs. using other available high end attenuators, and the best sounding stepped attenuators tend to be bigger than the Crack chassis can accomodate. So the Submissive in its own chassis that matches the Crack chassis may have some appeal to those who have the space for a second chassis in their setup.
> 
> We will be running some tests on a crossfeed circuit in the next few weeks.
> 
> Oh, and thanks for the order!



How much modification to the Crack will have to be done to defeat its volume control? And could the same thing be done with Smash preamp instead of Submissive?


----------



## JamieMcC

aeolus kratos said:


> http://www.ebay.com/itm/GEC-6AS7G-A1834-ECC230-pair-double-triode-thick-getter-audio-tubes-tested-/301214265739?pt=UK_Sound_Vision_Valves_Vacuum_Tubes&hash=item4621c4f18b
> 
> A pair of the legendary GEC 6AS7G tubes is on sale for a very reasonable price. Not sure how they are cheap like that but I think this is a good chance for anyone who wanted to have a chance try these wonderful tubes.


 
  
 Thanks for mentioning them and bringing them to everybody's attention I was bidding on them by the way


----------



## kothganesh

jamiemcc said:


> Fitting a choke and replacing the last electrolytic capacitor with a film capacitor makes a nice improvement to bass extension.


 
 I must thank you and Head fi'er Moatsart, you for the inspiration and him for selling the parts to me. Now I can't wait for the choke and the capacitors to show up.


----------



## Aeolus Kratos

jamiemcc said:


> Thanks for mentioning them and bringing them to everybody's attention I was bidding on them by the way


 

 Haha, Jamie, you really can't stop collecting the GECs, right? 
	

	
	
		
		

		
		
	


	



  
 Good luck with the bid!


----------



## punit

Selling one of my WE421A's if anyone's interested.
  
 http://www.head-fi.org/t/723867/western-electric-421a


----------



## guildenstern

RE impedance mismatch btwn AKG Q701 and Crack -- theoretically, yes, but in practice, maybe not. The Crack does a very nice job driving my AKG 702 65th Anniversary, a close cousin of Q701. For me, an unexpectedly musical combination. So, I wouldn't rule out the Q701.
  
 Quote:


bigfatpaulie said:


> Yes.


 
  
  


irishsammy said:


> I don't have the Speedball so I can't answer that question but...isn't the Q701 going to be a big impedance mismatch?


----------



## Armaegis

.sup said:


> How much modification to the Crack will have to be done to defeat its volume control?


 
  
 The easy was is connect the input and output tabs on the pot. The harder way is taking out the pot entirely. The easiest way is just leaving the pot on max


----------



## liamstrain

loquah said:


> Pretty sure this is the one:
> 
> http://www.ebay.com.au/itm/Assembled-Dale-23-Step-Attenuator-Volume-Control-100k-/270311271326?pt=US_Amplifier_Parts_Components&hash=item3eefceab9e


 
  
 I've got one of these in a drawer somewhere - but I'll be damned if I can figure out how to connect it (and it came with no documentation). I'm sure there is something on the intertubes, just haven't had the time to track it down yet.


----------



## Doc B.

.sup said:


> How much modification to the Crack will have to be done to defeat its volume control? And could the same thing be done with Smash preamp instead of Submissive?




Technically, sure you could do that. Not sure if it would sound better, as my philosophy has always been to use as few gain stages as possible. I admit to being surprised by the recent raves about putting a Quickie ahead of a Crack. I guess I need to play with that myself. We're certainly happy to sell them to anyone who finds that to be a sound that they prefer.


----------



## DutchGFX

I Wish I could spend time modding my crack, but I have too many projects going on. So sad to see all the discussions that I can't partake in


----------



## cheneric

Hey guys, I'm selling my crack! Not sure what's a reasonable price, but I'm short on cash.
  
 http://www.head-fi.org/t/723933/bottlehead-crack-with-speedball


----------



## EraserXIV

doc b. said:


> Yeah I would agree that upgrading the attenuator would probably be the most rewarding upgrade after the Speedball. In order to address that we are working on the idea of using a Submissive passive attenuator ahead of the Crack and replacing the stock pot in the Crack with an adjustable crossfeed circuit that can be defeated for those who don't want it in the signal path. We found that designing our own attenuator gave us the best results vs. using other available high end attenuators, and the best sounding stepped attenuators tend to be bigger than the Crack chassis can accomodate. So the Submissive in its own chassis that matches the Crack chassis may have some appeal to those who have the space for a second chassis in their setup.
> 
> We will be running some tests on a crossfeed circuit in the next few weeks.
> 
> Oh, and thanks for the order!




Very interesting! I have actually been thinking about doing something similar to this for a while. I'm don't like how to stock pot handles channel imbalance at the lower levels. Been think about throwing a passive preamp upstream to let me turn the pot higher. Taking it completely out of the equation sounds even better. Would turning the stock pot to max and then throwing a passive preamp upstream be essentially the same thing?


----------



## Doc B.

Yeah, turning the pot up all the way pretty closely emulates a simple grid load resistor at the input, except of course that there are wiper contacts and a carbon track rather than a simple metal film or whatever resistor. On paper that may not make any difference, but the whole point of the conversation in the first place is about changing the resistive materials to improve the sonics. If you are going to go to the trouble to put an attenuator with high quality resistors in ahead of the pot it might make more sense to swap the pot for a 100K ohm MF resistor.


----------



## spacequeen7

doc b. said:


> Technically, sure you could do that. Not sure if it would sound better, as my philosophy has always been to use as few gain stages as possible. I admit to being surprised by the recent raves about putting a Quickie ahead of a Crack. I guess I need to play with that myself. We're certainly happy to sell them to anyone who finds that to be a sound that they prefer.


 
 I'm very pleased with Quickie ..skeptical at first (Thanks to Matt and one of his posts) but I'm so glad it's finally here  ,swapped few tubes since I build it and I have to say that Quickie/PJCCS=> Crack/GEC A1834/E80CC Philips =>HD650 sounds superb , it made some tubes shine more then others ,this upgrade is worth every penny


----------



## MattTCG

spacequeen7 said:


> I'm very pleased with Quickie ..skeptical at first (*Thanks to Matt and one of his posts)* but I'm so glad it's finally here  ,swapped few tubes since I build it and I have to say that Quickie/PJCCS=> Crack/GEC A1834/E80CC Philips =>HD650 sounds superb , it made some tubes shine more then others ,this upgrade is worth every penny


 






...just trying to spread the love.


----------



## MoatsArt

Premium tubes for the Crack going cheap:
  
 http://www.ebay.com.au/itm/261511534435?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649
  
 http://www.ebay.com.au/itm/261511548467?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649


----------



## kothganesh

Listening to Sgt. Pepper's with the Crack and the HD 800. I have never heard this clarity and detail from the album before.


----------



## i luvmusic 2

This waiting time is killing me.....
	

	
	
		
		

		
		
	


	



 I already have the aluminum plates cut for the crack and no amp yet.


----------



## BiggieSmalls88

i luvmusic 2 said:


> This waiting time is killing me.....
> 
> 
> 
> ...


 
 Patience! It will be worth the wait.


----------



## i luvmusic 2

biggiesmalls88 said:


> Patience! It will be worth the wait.


 
 I hope so.
	

	
	
		
		

		
		
	


	



 I have another idea about this Crack i might build it stock and if i really like it i will build another crack using all upgraded parts and sell the stock crack.IMHO instead of squeezing all those big caps choked etc etc inside the crack case mind as will start from the scratch all you really need is plates wood some screws holesaw jigsaw drill/drill press(which i have) drill bits and a bit of know how to work with metals and wood.


----------



## networkn

Hi There!
  
 I am rechecking my voltages after an issue I had. I can't recall how I resolved this question: 
  
 I don't understand the instructions 5 and 6 on page 38. If I use the negative probe clip to connect to terminal 12, how can I connect the same lead to the ground buss?
  
 What is the ground buss? Is that the negative port on my multimeter?


----------



## networkn

Just posting a picture of my multimeter and ensuring I should be completing voltage checks with the leads connected like that, and with the dial set as such.


----------



## networkn

Well I just did what I thought was ok, and everything seems ok. Things showing as 0 are showing as 1.8mV, I presume that is ok ? It's strange to me that slightly changing the angle of the contact on a terminal changes the voltage massively.


----------



## JamieMcC

Most probably the best place for assistance on interpreting the manual or trouble shooting is on the Bottlehead Forum where you will find support provided direct from the Bottlehead team who designed the Crack and wrote the manual.  I suspect some of us might interpret written instructions differently so getting it straight from the horses mouth so to speak is the way to go imho.
  
 I hope you have enjoyed the build so far and welcome to the Crack club.


----------



## networkn

jamiemcc said:


> Most probably the best place for assistance on interpreting the manual or trouble shooting is on the Bottlehead Forum where you will find support provided direct from the Bottlehead team who designed the Crack and wrote the manual.  I suspect some of us might interpret written instructions differently so getting it straight from the horses mouth so to speak is the way to go imho.
> 
> I hope you have enjoyed the build so far and welcome to the Crack club.


 
  
 Thanks. I did post my results there a few days ago with no response, though it was the weekend. I'll have to be patient.


----------



## MoatsArt

Goodbye everyone.


----------



## networkn

moatsart said:


> Goodbye everyone.


 
  
 Huh?


----------



## dduck

OK, pretty worried now.
  
 I PM's him 10 minutes ago telling him that unless he told me RIGHT NOW he was OK, I would do my damndest to get EMTs his way.
  
 No answer.


----------



## dduck

All I get from his profile is the handle and that he's in Australia. I have been trawling his posts in the for sale forums hoping to find somebody who has bought stuff rom him, and thus may have contact info or location with better accuraxy. Thoughts?


----------



## dduck

I just PM's everybody who ever left him buyer/seller feedback, hoping to get an address.
  
 Anybody know how to get in touch with emergency medical services in Australia?


----------



## Loquah

dduck said:


> All I get from his profile is the handle and that he's in Australia. I have been trawling his posts in the for sale forums hoping to find somebody who has bought stuff rom him, and thus may have contact info or location with better accuraxy. Thoughts?


 
  
 All I know is he's in Inverell (I think) in rural NSW. Hope he's OK.
  
 He's had himself banned before when he's become to engaged in buying DIY gear, etc. so maybe he's just departing membership and nothing more serious - I sure hope so!!


----------



## dduck

loquah said:


> All I know is he's in Inverell (I think) in rural NSW. Hope he's OK.
> 
> He's had himself banned before when he's become to engaged in buying DIY gear, etc. so maybe he's just departing membership and nothing more serious - I sure hope so!!


 
  
 Last tim I saw a post that looked like that it didn't end well. This is why I'm freaking out a bit.
  
 You are also in DK, right?


----------



## dduck

Anybody has a real name for the guy? We have a rough location, name would help a lot.


----------



## dduck

OK I have an address. Anybody know how to get in touch with Austratlian authorities?


----------



## dduck

Called local cops, they will check in on him. Home I'm just a nervous nanny


----------



## EraserXIV

It seems that ebay listing he posted earlier is his. He's selling quite a few tubes so maybe he's just trying to get out of the audio hobby. Hope all turns out well.


----------



## dduck

Status: I got his address, called the local cops, and they said they would check on him.
  
 And I'm quite willing to be called an ******* for going a little overkill on this. I'll even apologize.


----------



## kothganesh

dduck said:


> Status: I got his address, called the local cops, and they said they would check on him.
> 
> And I'm quite willing to be called an ******* for going a little overkill on this. I'll even apologize.


 
 Just saw this. His name is Nathan and I bought some stuff from him last week. He said he was getting into SS gear. Hope he is well.


----------



## networkn

Pretty nice community here I have to say.


----------



## Loquah

dduck said:


> Status: I got his address, called the local cops, and they said they would check on him.
> 
> And I'm quite willing to be called an ******* for going a little overkill on this. I'll even apologize.


 
  
 Better to be safe than sorry - thank you dduck for checking on Nathan. He is a really genuine and lovely guy dealing with some challenging issues. No need to apologise I expect - it is wonderful of you to care enough to contact the authorities.


----------



## dduck

loquah said:


> Better to be safe than sorry - thank you dduck for checking on Nathan. He is a really genuine and lovely guy dealing with some challenging issues. No need to apologise I expect - it is wonderful of you to care enough to contact the authorities.


 
  
 Thanks,
  
 Experience has taught me to err on the side of caution in case of suspicions in this area.
  
 Still no word from the local cops, but frankly I don't expect them to ever get back to me. That would be quite a lot to ask, and really it's none of my business.
  
 Sorry that I can't give any kind of update, but so it goes.
  
 I'll leave for the US in about 20 hours, so my ability to follow up is unfortunately limited. To the others who are worried (got some PMs), Good to know you care!


----------



## JamieMcC

dduck said:


> Status: I got his address, called the local cops, and they said they would check on him.
> 
> And I'm quite willing to be called an ******* for going a little overkill on this. I'll even apologize.


 
  
 Good on ya mate and well done for taking the initiative.
  
 Nathans a nice guy.


----------



## JamieMcC

What input tubes are you guys getting good results with when using the WE412a?


----------



## dduck

Good news everyone, Nathan is fine, and I was overly worried. Luckily he was not annoyed with me, and seemed touched that so many strangeres cared 

Sorry to have kicked up a bit of dust, but I once lost a buddy because the people who should kept an eye on him during a time of trouble... didn't. I promised myself to never underestimate these things again, and so I acted.


----------



## liamstrain

I, for one, would much rather someone check in unnecessarily, than not when it was needed. Good one dduck.


----------



## kothganesh

dduck said:


> Good news everyone, Nathan is fine, and I was overly worried. Luckily he was not annoyed with me, and seemed touched that so many strangeres cared
> 
> 
> 
> ...


 
 Man, kudos to you. You went the extra mile and that's a good thing.


----------



## MoatsArt

Rumours of my death have been greatly exaggerated. Thank you for caring and commenting. I am taking a break for a while to heal from my DIY and tube addiction.

Does anyone want to buy my Crack? It has:

1. Speedball
2. 240V transformer
3. Obbligato Gold output capacitors (94 uF per channel) 
4. Switch (3 way) to allow the use of 12AU7, 12BH7 & E80CC tubes whilst maintaining the stock operating point of the power tube.
5. Tung Sol 7236 & RCA clear top tubes

About $700 value. $500 including shipping within Australia.


----------



## Aussiejuggalo

moatsart said:


> Rumours of my death have been greatly exaggerated. Thank you for caring and commenting. I am taking a break for a while to heal from my DIY and tube addiction.
> 
> Does anyone want to buy my Crack? It has:
> 
> ...




:O ermahgerd so tempting, if I had the money


----------



## Lugnegaard

Just sold my crack for US $870. Pretty good for a standard Crack (no Speedball).
  
 Guess good looks sell


----------



## Vitalstatistix

moatsart said:


> Rumours of my death have been greatly exaggerated. Thank you for caring and commenting. I am taking a break for a while to heal from my DIY and tube addiction.
> 
> Does anyone want to buy my Crack? It has:
> 
> ...




I'm interested! I'll send you a PM.


----------



## Armaegis

lugnegaard said:


> Just sold my crack for US $870. Pretty good for a standard Crack (no Speedball).
> 
> Guess good looks sell


 
  
 Well of course. How many hours did you put into it to get that level of finish? The price doesn't seem all that bad considering the labour that went into it.
  
 (though after all that work, you really should have put in the Speedball and charged $1k)


----------



## Lugnegaard

You're right, I did up many hours into it, but it's still pretty good since the electronics are all stock. 
 I will order a second one with SB straight away


----------



## i luvmusic 2

lugnegaard said:


> Just sold my crack for US $870. Pretty good for a standard Crack (no Speedball).
> 
> Guess good looks sell


 
 Very nice i like that Rounded edges.I hope you don't mind if i copy the Rounded edges when my Crack arrived.


----------



## Keithpgdrb

lugnegaard said:


> Just sold my crack for US $870. Pretty good for a standard Crack (no Speedball).
> 
> Guess good looks sell


 
 That finish work is truly astounding.  But I do have to say I am surprised you got that much for an electronically stock crack.  You did very well!!!!


----------



## NightFlight

moatsart said:


> Rumours of my death have been greatly exaggerated. Thank you for caring and commenting. I am taking a break for a while to heal from my DIY and tube addiction.
> 
> Does anyone want to buy my Crack? It has:
> 
> ...


 
  
 Yes people who are looking to do themselves in do not have need of money... just saying.


----------



## NightFlight

keithpgdrb said:


> That finish work is truly astounding.  But I do have to say I am surprised you got that much for an electronically stock crack.  You did very well!!!!


 
  
 Looks trump functionality every time. Read: Apple.  
 People trust their eyes all too much. It screws them over a lot of the time too. 
  
 Personally, I listen to audio in a dark room most of the time.. with my eyes closed, so - I don't care much what it looks like. 
  
 I find it funny in the last few posts we've seen a tweaked crack and tubes go for cheap which is worth a small fortune. A stock unit that has looks go for more.  Tells you there is money to be made in looks.


----------



## MoatsArt

nightflight said:


> Yes people who are looking to do themselves in do not have need of money... just saying. :wink_face:




I have no need of money, but my family does. If I kill myself my wife will have two children to support. I think your comment is in poor taste.


----------



## Keithpgdrb

Let's talk crack


----------



## JamieMcC

Hi Nathan I would be interested to hear what you thought of those Obbligato Golds? I am guessing you paralleled up two of the 47uf each side.
  
 Cheers


----------



## NightFlight

moatsart said:


> I have no need of money, but my family does. If I kill myself my wife will have two children to support. I think your comment is in poor taste.


 
  
 Sorry, no poor taste intended. It was an observation stated to calm the masses.  Not intended as an attack on your character in any sense - in fact, just the opposite.  It was a generalization and sorry if you took offense to it. Although still, I stand my my generalizations, as generally speaking, they are generally right.
  
 I've no idea what is triggering your sales and sorry to see you leave the Crack club. Hopefully with time you'll be back.


----------



## MattTCG

I left the crack club for a brief period. Then realized the error of my ways. The crack/650 are now a permanent part of my collection.


----------



## bigfatpaulie

matttcg said:


> I left the crack club for a brief period. Then realized the error of my ways. The crack/650 are now a permanent part of my collection.


 
  
 The Crack and HD6X0 combo really is something special.  I feel it punches far above its price point on so many levels; sound, comfort, etc.  But most importantly it is just such an ENJOYABLE listen.
  
 Welcome back


----------



## kothganesh

matttcg said:


> I left the crack club for a brief period. Then realized the error of my ways. The crack/650 are now a permanent part of my collection.


 
 Matt:
  
 Welcome back. How's the HD 800 on your Crack. Mine sounds sublime with constant use of the combo. I recently switched the stock cable with the Red cable from WyWires (just yesterday). I've been advised to break it in for 20 hours before hearing better SQ. I don't want to start the all-familiar cable debate so let's see.


----------



## benjaminhuypham

Hi Matt, I'd love to know how HD650 on Crack vs T1 on Crack or even HD800 on Crack as well. I just ordered the Crack/speedball and still wait for them arrived. This waiting is killing me -(. Welcome back to "crack addict" club and I'm very happy to become a part of this addiction by now. 

I didn't choose the "crack life", the crack life chose me.


----------



## atsq17

Crack + T1 is a great combo with excellent details, imaging, space, layering (a real "3D" sound relative to my past amps) but I found that treble was a bit overwhelming for me. 
  
 I corrected this by getting a natural sounding and bassy Neko Audio D100 Mk2 DAC and just as importantly, getting the T1 re-cabled with Whiplash V3 Hybrid cable. 
  
 I have A-Bed my system with the stock cable vs the re-cabled T1 and the re-cabled T1 completes an end-game setup for me whereas the stock cable T1 was too rough around the edges and would make me reconsider the entire setup. Bear in mind though that my friend's stock T1 is quite new (probably only 100+ hours on it) and may not be broken in properly. 
  
 My TH900 collects dust while I use my T1 & Crack daily. Call me addicted!  
  
 I have tried my friend's HD800 and while it is good I find that it lacks the same thump as the T1. It is a bit more spacious sounding though. The other thing I've found is that the HD800 on the Crack is borderline too much treble. Getting a good cable (my friend got a Norne Draug 8 cable) does address this issue though. 
  
 I did try the HD800 on Loquah's Mainline once though and the treble was silky smooth. No treble issue whatsoever.


----------



## Loquah

atsq17 said:


> Crack + T1 is a great combo with excellent details, imaging, space, layering (a real "3D" sound relative to my past amps) but I found that treble was a bit overwhelming for me.
> 
> I corrected this by getting a natural sounding and bassy Neko Audio D100 Mk2 DAC and just as importantly, getting the T1 re-cabled with Whiplash V3 Hybrid cable.
> 
> ...


 
  
 I was just going to comment on the Mainline taking care of that last bit of smoothness - its treble is more refined than the Crack.
  
 We still have to test my secret foam mod on your T1s, Andy.


----------



## atsq17

With my friend's stock T1, we can have a 3 way shootout. Stock, Stock + Mod, Cabled. If the difference seems worthwhile we should mod mine too and test!


----------



## JamieMcC

benjaminhuypham said:


> Hi Matt, I'd love to know how HD650 on Crack vs T1 on Crack or even HD800 on Crack as well. I just ordered the Crack/speedball and still wait for them arrived. This waiting is killing me -(. Welcome back to "crack addict" club and I'm very happy to become a part of this addiction by now.
> 
> I didn't choose the "crack life", the crack life chose me.


 
  
 On a stock build the HD650 and T1's have I would say perhaps have  more in common than you might think and while the T1's are noticeably a little more refined and detailed but there can be a edge to the highs with some sibilance the 650's have the edge on the mid range and a more even all round performance.  Later when I purchased the T1 I initially preferred the HD650 finding the sibilance distracting  and annoying on the T1 for the types of music I listen to.
  
 It was soon after this I started down the Crack upgrade path and the difference it has made is really quiet noticeable both the HD650 and T1 scaled well with some simple modification which were basically just swapping one part for another it didn't take to long to realise the the scaling of the HD650's had plateaued while the T1 continued to benefit further and while the changes in the sonics with the 650s was subtle the differences in the T1's performance was much more noticeable.
  
 The annoying sibilance disappeared the level of resolution and detail retrieval is now insane details that are easily missed or barely heard with 650's  on the T1 are clear and have further textures and nuances of their own. One of the most welcome improvements with the T1 is the modifications have lead to a filling out of the midrange with the stock crack it felt a little on the lean side but the modifications have added soul and given them a welcome kiss of life.
  
 The upshot being the T1 combo of Crack+SB a good tube and around  $100 worth of internal upgrades the amp goes from great to epic and is a seriously good performer. My HD650 have now been claimed by the misses. While the BeyerT1's abilities continue to amaze me on a daily bases even after 6 months of ownership.


----------



## Loquah

atsq17 said:


> With my friend's stock T1, we can have a 3 way shootout. Stock, Stock + Mod, Cabled. If the difference seems worthwhile we should mod mine too and test!


 
  
 Sounds perfect!! We should arrange that soon


----------



## MattTCG

kothganesh said:


> Matt:
> 
> Welcome back. How's the HD 800 on your Crack. Mine sounds sublime with constant use of the combo. I recently switched the stock cable with the Red cable from WyWires (just yesterday). I've been advised to break it in for 20 hours before hearing better SQ. I don't want to start the all-familiar cable debate so let's see.


 
  
  


benjaminhuypham said:


> Hi Matt, I'd love to know how HD650 on Crack vs T1 on Crack or even HD800 on Crack as well. I just ordered the Crack/speedball and still wait for them arrived. This waiting is killing me -(. Welcome back to "crack addict" club and I'm very happy to become a part of this addiction by now.
> 
> I didn't choose the "crack life", the crack life chose me.


 
  
 I had problems with the Crack and it was just repaired. I sent off the hd800 to a friend for an audition. They will be back on Saturday so I'll finally get to hear them together for the first time. 
  
 And don't worry...I plan to make lot's of comments on the pairing.


----------



## kothganesh

Hi everyone:
  
 I had my Crack with speedball assembled in India. From hour one, the first 30-35 minutes of usage are fine. Then the hum starts...first in between songs, then during the first 10-15 seconds of a song. The occurrences are completely random. The noise dies and then comes back at another place for another random period of time. I've changed the tubes, changed my HD 800 cable but to no avail. What else should I be looking out for?
  
 Thanks in advance for your suggestions.


----------



## MattTCG

You might do best to post this on the Bottlehead forums. The advice there is spot on. GL!!


----------



## kothganesh

matttcg said:


> You might do best to post this on the Bottlehead forums. The advice there is spot on. GL!!


 
 OK thanks


----------



## Keithpgdrb

Sounds like interference, not a build issue. Keep anything radio controlled, wifi, and cell phones away from the crack. It can pick those things up. I agree though to go to the bh forums.


----------



## kothganesh

keithpgdrb said:


> Sounds like interference, not a build issue. Keep anything radio controlled, *wifi*, and cell phones away from the crack. It can pick those things up. I agree though to go to the bh forums.


 
 Never thought about this. I will check again. Thanks a lot.


----------



## bigfatpaulie

kothganesh said:


> Hi everyone:
> 
> I had my Crack with speedball assembled in India. From hour one, the first 30-35 minutes of usage are fine. Then the hum starts...first in between songs, then during the first 10-15 seconds of a song. The occurrences are completely random. The noise dies and then comes back at another place for another random period of time. I've changed the tubes, changed my HD 800 cable but to no avail. What else should I be looking out for?
> 
> Thanks in advance for your suggestions.


 
  
 I had a noise problem at the beginning too.  I moved it 2 inches away from the wall and now it's silent.  Try moving the amp around.


----------



## .Sup

If your Crack is connected to a power strip try disconnecting other devices or connect amp in the first power strip socket.


----------



## atsq17

kothganesh said:


> Hi everyone:
> 
> I had my Crack with speedball assembled in India. From hour one, the first 30-35 minutes of usage are fine. Then the hum starts...first in between songs, then during the first 10-15 seconds of a song. The occurrences are completely random. The noise dies and then comes back at another place for another random period of time. I've changed the tubes, changed my HD 800 cable but to no avail. What else should I be looking out for?
> 
> Thanks in advance for your suggestions.


 
  
 I had one I couldn't get rid off and it ended up being a single loose connection at the tube socket. When i pinned this back into place, it stopped. Of course this could be my one obscure case. My problem was caused by having huge ass Mundorf M-Caps loose and pulling on the connections when moving from place to place.


----------



## kothganesh

keithpgdrb said:


> Sounds like interference, not a build issue. Keep anything radio controlled, wifi, and cell phones away from the crack. It can pick those things up. I agree though to go to the bh forums.


 
  


bigfatpaulie said:


> I had a noise problem at the beginning too.  I moved it 2 inches away from the wall and now it's silent.  Try moving the amp around.


 
  


.sup said:


> If your Crack is connected to a power strip try disconnecting other devices or connect amp in the first power strip socket.


 
  


atsq17 said:


> I had one I couldn't get rid off and it ended up being a single loose connection at the tube socket. When i pinned this back into place, it stopped. Of course this could be my one obscure case. My problem was caused by having huge ass Mundorf M-Caps loose and pulling on the connections when moving from place to place.


 
  
 At the outset, thank you all. I took the Crack to my office and the noise/hum just vanished. The major difference is that I switched to my LAN(hence no wifi) and plugged my Crack into a separate section of the power strip that I use. This seems to have done the trick.


----------



## Vitalstatistix

Quick question about the Cardas Quad Eutectic Silver solder - what is the consensus on its impact on sound (if any)? Any advice on how to use it properly?


----------



## kothganesh

And, thanks to Head-fi'er Moatsart, I am getting my DIY friend to change some capacitors and chokes on the Crack. Details from Monday


----------



## JamieMcC

vitalstatistix said:


> Quick question about the Cardas Quad Eutectic Silver solder - what is the consensus on its impact on sound (if any)? Any advice on how to use it properly?


 

 Not sure about the Cardas Quad Silver, but after trying out the standard Cardas Quad Eutectic myself I wont be going back to 60/40, I really can't say how or if it impacts the sound but do think for the few dollars a couple of meters costs (which is all it takes to build a Crack) it is money worth spending for anyone who is new to soldering as imo its more forgiving to work with and anything that can help reduce trouble shooting later due to poor solder joints is a plus for anyone new to diy. Poor connections are probably one of the most common causes that require trouble shooting on the BH forum.


----------



## spacequeen7

matttcg said:


> *I had problems with the Crack and it was just repaired*. I sent off the hd800 to a friend for an audition. They will be back on Saturday so I'll finally get to hear them together for the first time.
> 
> And don't worry...I plan to make lot's of comments on the pairing.


 
 what was the problem ?


----------



## MattTCG

Just a couple of toasted transistors during a speedball upgrade. RonO got it all sorted out. Thank you kindly sir!! You are the man.


----------



## liamstrain

vitalstatistix said:


> Quick question about the Cardas Quad Eutectic Silver solder - what is the consensus on its impact on sound (if any)? Any advice on how to use it properly?


 
  
 No impact at all to sound. But it is easier to control than some of other solders (mostly due to the smaller diameter).
  
 Note, if you get the lead free, it has a higher melt point, so you need to watch your technique and if needed, use heatsinks to make sure you don't toast anything important. If you are new to soldering, get the leaded variety.


----------



## JamieMcC

Finally managed to get hold of some Mundorf 100uf's to roll and have been happily swapping backwards and forwards between caps for the last few hours...


----------



## Loquah

jamiemcc said:


> Finally managed to get hold of some Mundorf 100uf's to roll and have been happily swapping backwards and forwards between caps for the last few hours...


 
  
 Are you in love yet?


----------



## Deterministic NL

First of all I have to say it is a blast building Bottlehead gear.  I've built several kits over the years.  Couple of Foreplay 2's, Couple of Foreplay 3's, Paramours, SeX Amp, Couple of Cracks SeYy Speakers....probably more I'm forgetting.  Done all the mods to all the gear as well.  Fantastic quality and just fun to make.
  
 I've finally found the magic configuration for my BH Crack here in my living room.  Some will probably shake their heads in disbelief but I'm telling you it works for me.
  
 Bottlehead Crack w/Speedball
 Western Electric 421A
 Orange label RCA clear top (I'm sorry my mega buck, rare, made by aliens 12AU7's don't compliment the 421A like this one Clear Top I have).
 Sennheiser HD650
 Fiio E17 plugged into 2012 Mac Mini running Clementine.  I've found if I go to the Spotify app somewhere and select an album and create a new playlist with it then play it back through the Spotify plugin in Clementine with the output set as Audo Sink (OSX) then it sounds crazy, ridiculously, stupidly amazing.  Listening to Amber Rubarth "Sessions From the 17th Ward" and I've never heard it this good.
  
 If you haven't experienced the Bottlehead Crack you absolutely should.


----------



## Sonido




----------



## JamieMcC

loquah said:


> Are you in love yet?


 
  
 The Mundorfs and I are still courting 
	

	
	
		
		

		
			





 and while there are noticeable differences between the films caps I have on hand its not particularly as clear cut as I was expecting or would like considering the price differences.  
  
 I do think its safe to say that anyone fitting Mundorfs won't be disappointed and will have a very nice sounding Crack. Also I have kept my Teflon bypass in place today and they will be masking some of the differences so tomorrow (err later today after I have got some sleep 1 am here) the Teflons will come out and then try again with just the 100ufs on their own.


----------



## Loquah

jamiemcc said:


> The Mundorfs and I are still courting
> 
> 
> 
> ...


 
  
 I forgot to ask which series Mundorfs you're using?


----------



## MattTCG

sonido said:


>


 
  
 Looking good!! Waiting for your impressions.


----------



## i luvmusic 2

Anyone of you guys used this TEAC - UD-H01 DAC with the CRACK?Thanks!


----------



## Sonido

matttcg said:


> Looking good!! Waiting for your impressions.



Nah I'll hold back my impressions. I'll let you hear it for yourself and make your own impressions so you won't be influenced by my words


----------



## JamieMcC

loquah said:


> I forgot to ask which series Mundorfs you're using?


 
  
 They are the M-cap 400v 100uf versions.


----------



## Loquah

jamiemcc said:


> They are the M-cap 400v 100uf versions.


 
  
 That's what we installed in @atsq17's - I thought they sounded great (with no comparison to any others because I built it from scratch with the upgrades in place)


----------



## listen4joy

my crack+speedball is on the way. i want to put best tubes. i heard the sophia among the best
  
 http://www.sophiaelectric.com/
  
 can you tell me from this site what will be suit for crack?


----------



## kothganesh

jamiemcc said:


> Fitting a choke and replacing the last electrolytic capacitor with a film capacitor makes a nice improvement to bass extension.


 
 Hi Jamie:
  
 I got 2 chokes and a film capacitor. Unfortunately, I don't know where it goes and neither does my friend who assembled it for me. Can you help with a photo or a brief note as to where all these things go? Thanks.


----------



## Aeolus Kratos

Hi guys, can I join this wonderful club with my new modded Crack? 
	

	
	
		
		

		
		
	


	



  

  

  

  

  
 And...in action!
  

  

  

  
 Cheers,
  
 Kratos.


----------



## i luvmusic 2

What is that Ring with Beads on the tubes what do they do?


----------



## JamieMcC

kothganesh said:


> Hi Jamie:
> 
> I got 2 chokes and a film capacitor. Unfortunately, I don't know where it goes and neither does my friend who assembled it for me. Can you help with a photo or a brief note as to where all these things go? Thanks.


 

 Hi, have a good read of this bb http://bottlehead.com/smf/index.php/topic,6030.0.html on the Bottlehead forum all the info required to undertake the mod can be found there. It is relatively straight forward exchanging one part for another. Deciding on a solution for how and where to mount chokes is perhaps the most challenging aspect.
  
 The bhf is probably a much better place for Q&A on technical subjects.
  
 Have fun


----------



## guildenstern

listen4joy said:


> my crack+speedball is on the way. i want to put best tubes. i heard the sophia among the best
> 
> http://www.sophiaelectric.com/
> 
> can you tell me from this site what will be suit for crack?


 

 Nothing against Sophia (I own and like their little Baby amp), but among the Sophia-branded tubes they sell, I don't see any power tubes suited for Crack. They do sell a 12AU7 tube that might be fun to try, but you can get fine NOS tubes for about the same money.
  
 If you want "the best," you'll find plenty of recommendations in the head-fi threads, though "the best" is relative to the headphones you're driving -- that is, a particular combination of tubes will tailor the sound of the amp in a way that most pleases you for the specific headphones you're using. For your adventures in tube rolling, a pretty safe bet for a starting point is an RCA clear top 12AU7 with a Tung Sol 5998 power tube. But since the Tung Sol is getting hard to find and going for ridiculously inflated prices, you might instead try an RCA 6AS7G "coke-bottle" style tube, preferably a black-plate version from the early 1950s. I recently ordered some from Brent Jesse, and they sound very good. Also available here (though I have not tried this vendor): http://tubeworldexpress.com/collections/power-tubes/products/copy-of-6as7g-rca-nos-1951-pair


----------



## kothganesh

jamiemcc said:


> Hi, have a good read of this bb http://bottlehead.com/smf/index.php/topic,6030.0.html on the Bottlehead forum all the info required to undertake the mod can be found there. It is relatively straight forward exchanging one part for another. Deciding on a solution for how and where to mount chokes is perhaps the most challenging aspect.
> 
> The bhf is probably a much better place for Q&A on technical subjects.
> 
> Have fun


 
 Thanks Jamie.


----------



## JamieMcC

aeolus kratos said:


> Hi guys, can I join this wonderful club with my new modded Crack?
> 
> 
> 
> ...


 
  





  Nice how are you liking it with your T1's, your clarity cap bypass looks interesting what value did you use? 
  
 You might want to try adding a inexpensive Russian 2.2uf K72P6 Teflon film cap to bypass each of the 100uf coupling caps. This worked well with my T1's it added smoothness and refinement to the top end along with improved resolution across the board. I was really pleased with the results.


----------



## i luvmusic 2

Holy Crap those RCA 6AS7G's are way too much.


----------



## Aeolus Kratos

i luvmusic 2 said:


> What is that Ring with Beads on the tubes what do they do?


 
 The rings are called 'tube dampers'. It somehow helps to improve microphonics and bring a more focused imaging. But it's just theory, I actually don't feel that it worked that much, maybe I was just imagining.
  


jamiemcc said:


> Nice how are you liking it with your T1's, your clarity cap bypass looks interesting what value did you use?
> 
> You might want to try adding a inexpensive Russian 2.2uf K72P6 Teflon film cap to bypass each of the 100uf coupling caps. This worked well with my T1's it added smoothness and refinement to the top end along with improved resolution across the board. I was really pleased with the results.


 
 Thanks for the recommendation, Jamie!! I'll definitely try that, but now I'm very happy with my current Crack, it really took the T1 to breathtaking level!


----------



## i luvmusic 2

aeolus kratos said:


> i luvmusic 2 said:
> 
> 
> > What is that Ring with Beads on the tubes what do they do?
> ...


 
 Ok Thank You!


----------



## NightFlight

vitalstatistix said:


> Quick question about the Cardas Quad Eutectic Silver solder - what is the consensus on its impact on sound (if any)? Any advice on how to use it properly?


 
  
 Possibly the easiest solder to use. I set my iron to 650F and find it responds well enough. Your hookup wire should be making direct connections and the solder binding it in place, but still plays a roll.  A lot of audiophiles swear by Cardas Quad and thus nothing bad has come of it. I've not even heard of bad batches.
  
 As for sonics, one could argue that solder is part of the chain and has impact on the same order as changing cables. It breaks in just like any other solid conductor.  But then, were getting into the hazy area of quarks and gremlins.


----------



## palmfish

After several weeks of deliberations, I have decided to sell my Crack. I just put my listing in the For Sale Forum.
  
 I like my Crack and have enjoyed it since I built it last year, but I just don't use it often enough. It's a beautiful performer and build and I would love to see it go to a head-fier that will use/appreciate it.


----------



## MattTCG

^^ Sorry to see you go. What will you power your 800 with?


----------



## palmfish

My Essence One Muses.
  
 Thank you Matt. I'm probably going to sell my HD 800's too.
  
 I'm still struggling to reconcile, but my hearing loss and tinnitus just makes music less enjoyable than it used to be. I don't look forward to listening anymore and the Crack and 800's are wasted on me. I'm thinking I'll come full circle buy a pair of HD 600's (they were my first hi-fi headphones) with the proceeds.


----------



## MattTCG

Very sorry to hear about the health issues. I've also struggled significantly with tinnitus and hearing problems over the past year or two. It's the kiss of death for people who are truly passionate about enjoying music. 
  
 My latest strategy is just to ignore it. I've tried all other conventional methods.


----------



## palmfish

I'm sorry that you have it too. It is reassuring to know you're not alone.

I have had declining hearing and growing tinnitus over the past 15 years or so. I finally got hearing aids from the VA last October and they have helped a lot. The downside is the hearing aids allowed my brain to "relax" and so my unaided hearing is more muffled than ever before. My choice with music is to either listen unaided and try to EQ the high frequencies way up (which is difficult to do well) or listen with my aids in (which creates artifacts and distortion).

I can still enjoy music, just not nearly to the degree that I used to.

There are other fulfilling things in my life so I choose to not be upset and simply walk a slightly different path. Life goes on


----------



## palmfish

I forgot to post the link to my Crack listing...

http://www.head-fi.org/t/725828/bottlehead-crack-non-speedball


----------



## MattTCG

Keep your chin up brother. Thoughts and prayers with you.


----------



## Loquah

Matt and others, if your hearing issues occurred relatively quickly as opposed to gradual noise or age induced hearing loss, you might want to look into chiropractic and myotherapy support.

I suffered a moderate-severe case of Bells Palsy about 2 years ago. With it came a hearing loss in my left ear and tinnitus in both. Doctors and audiologists were no help unfortunately, but through chiropractic visits and a bit of self experimentation I've discovered that my issues are caused by spinal compression and imbalances caused by sitting at a computer too long with poor posture/ergonomics. I can actually create tinnitus now by moving my neck in certain ways that must increase tension / pressure in the muscles around the spine which proves the problem is transient and muscular in origin.

Long story not-so-short, myotherapy massage sessions (which were very uncomfortable at first due to years of tension I wasn't even aware of) and some chiro adjustments have my body showing daily improvements. I'm back to about 90% right and the next steps will be gradual, but achievable with consistent stretching, exercise and occasional professional support.

Sorry for the long, off-topic post, but as a fellow lover of music with a deep understanding of the body's abilities to heal many things, I wanted to share in the hope that IF your situation is recoverable you have every chance to continue enjoying the wonders of music. If course, if the cause is one that's unrecoverable then I thoroughly agree with palmfish's approach of finding the other joys in life and walking on...


----------



## MattTCG

Thanks for sharing Loquah. That type of discussion is always appropriate here IMHO. I attribute the cause of my issues to firing a gun several times with no hearing protection. After that event, I got my first symptoms the very next day. 
  
 I'm open to all forms of therapy. I've been to the ENT for treatments 6 times. He didn't tell me anything that I hadn't learned from the internet already.


----------



## liamstrain

nightflight said:


> As for sonics, one could argue that solder is part of the chain and has impact on the same order as changing cables. It breaks in just like any other solid conductor.  But then, were getting into the hazy area of quarks and gremlins.


 
  
 Precisely. No audible difference. No break in - and if anything less effect than cables would have, since they are larger conductive surfaces (less resistance) and infrequent.


----------



## palmfish

Good point Loquah and well stated.

Everyone is different (obviously) and I believe that, at least in my case, my tinnitus is a result of a combination of factors. Noise induced hearing loss and neural plasticity are closely related, but I too can change my tinnitus by moving my neck and or jaw. It is also affected by my diet and the quality of my sleep.

The truth of the matter is that doctors and scientists are still mostly ignorant about the nature of tinnitus today. Fortunately (or unfortunately) it is becoming a more common and serious problem in our society and it is getting a lot of attention from the medical/scientific community. 

I don't have hopes for a cure or significant relief in my lifetime, but I do believe the generation behind me will have a solution.


----------



## palmfish

Matt, in my experience, ENT's are among the most ignorant group of professionals WRT tinnitus. An audiologist is your best bet for help (and hearing aids).

Do some reading on neural plasticity and tinnitus...


----------



## MattTCG

Doing some research now. Thank you kindly.


----------



## SP Wild

matttcg said:


> Thanks for sharing Loquah. That type of discussion is always appropriate here IMHO. I attribute the cause of my issues to firing a gun several times with no hearing protection. After that event, I got my first symptoms the very next day.
> 
> I'm open to all forms of therapy. I've been to the ENT for treatments 6 times. He didn't tell me anything that I hadn't learned from the internet already.


 
  
 Firing guns taught me something about physiology and hearing.  Sighting a rifle with hearing protection on is a terrifying experience for me.  But out in the field, firing a rifle after sprinting for your prey, without protection (can't stalk if you can't hear), it sounds more like back round noise.  Could easily start critiquing the sound quality of various rifles, shotguns and ammo. 
  
 Its weird, when thoroughly warmed up, no ringing, no issues and apparently no pain.  But cold with protection and its terrifying.  I wonder if adrenaline can protect your hearing for short moments.  Firing a rifle in the field is actually a rare occurence, a clean shot can be very hard, try holding a rifle or shotgun still after sprinting.
  
 But that is not why I am here.  I wanna know if anybody has used the crack as a preamp?  Am tossing between an all out 300b bottle head for speakers or a tube preamp.  It doen't help after listening to my HD650s on the reference rig and realising that its too good a headphone to not give it the amp it needs to shine.


----------



## olegausany

Crack as preamp for speaks? I think you better go with Decware CSP amps for that


----------



## Loquah

sp wild said:


> Firing guns taught me something about physiology and hearing.  Sighting a rifle with hearing protection on is a terrifying experience for me.  But out in the field, firing a rifle after sprinting for your prey, without protection (can't stalk if you can't hear), it sounds more like back round noise.  Could easily start critiquing the sound quality of various rifles, shotguns and ammo.
> 
> Its weird, when thoroughly warmed up, no ringing, no issues and apparently no pain.  But cold with protection and its terrifying.  I wonder if adrenaline can protect your hearing for short moments.  Firing a rifle in the field is actually a rare occurence, a clean shot can be very hard, try holding a rifle or shotgun still after sprinting.
> 
> But that is not why I am here.  I wanna know if anybody has used the crack as a preamp?  Am tossing between an all out 300b bottle head for speakers or a tube preamp.  It doen't help after listening to my HD650s on the reference rig and realising that its too good a headphone to not give it the amp it needs to shine.


 
  
 That's interesting to read, SP, but it makes complete sense.
  
 There is a reflex in the ear (called the stapedius reflex) which is designed to dampen the acoustic information transmitted from the ear drum to the cochlear (and the easily damaged components there-in). My guess is that the near-complete silence of hearing protection allows the ear to relax this protection to a greater level making the very loud (relatively) concussion of a rifle shot quite traumatic (in terms of our perception versus the peace and quiet before the shot) even with hearing protection. It would make sense that adrenalin and the natural survival reactions of the body in that state would tighten the stapedius muscle and prepare the body for various environmental onslaughts including loud noises.
  
 As you say, warming up is important - essentially these are still muscles, connective tissues and moving parts at work and need to be eased into whatever we're doing - a good argument for always starting your Crack sessions at lower volume and gradually building to your prime listening volume over a few minutes (see how I brought my wild tangent back to the thread topic? 
	

	
	
		
		

		
			





)


----------



## SP Wild

loquah said:


> That's interesting to read, SP, but it makes complete sense.
> 
> There is a reflex in the ear (called the stapedius reflex) which is designed to dampen the acoustic information transmitted from the ear drum to the cochlear (and the easily damaged components there-in). My guess is that the near-complete silence of hearing protection allows the ear to relax this protection to a greater level making the very loud (relatively) concussion of a rifle shot quite traumatic (in terms of our perception versus the peace and quiet before the shot) even with hearing protection. It would make sense that adrenalin and the natural survival reactions of the body in that state would tighten the stapedius muscle and prepare the body for various environmental onslaughts including loud noises.
> 
> ...


 
  
 I guess your wink was directed at my tendency to wade into a thread, totally OT after lurking and finding a post I could comment on with personal experience?  Then again I don't think it is totally off track, if it this that prompts me to engage in communication with members of more experience.  Mainly, I've been lurking because 300b amps are raved about, and the most affordable iteration is the Bottlehead unit.
  
 This sterilised version of head-fi has me a little concerned.  Nevertheless, I shall be on my merry way in search for more information to help make my next big ticket item purchase decision....a glowing sweet botlle of music.  Nedd to put words into action, have been speaking of this purchase forever but never quite committed, an integrity thing for me, one must do what one says one will do.


----------



## jgreen16

loquah said:


> That's interesting to read, SP, but it makes complete sense.
> 
> There is a reflex in the ear (called the stapedius reflex) which is designed to dampen the acoustic information transmitted from the ear drum to the cochlear (and the easily damaged components there-in). My guess is that the near-complete silence of hearing protection allows the ear to relax this protection to a greater level making the very loud (relatively) concussion of a rifle shot quite traumatic (in terms of our perception versus the peace and quiet before the shot) even with hearing protection. It would make sense that adrenalin and the natural survival reactions of the body in that state would tighten the stapedius muscle and prepare the body for various environmental onslaughts including loud noises.
> 
> ...


 

 I'm not sure about any type of hearing protection that affords near-complete silence, at least in relationship to moderate to high noise levels. I also suffer from tinnitus after 25+ years in the air separation business, which as part of the process uses air compressors, turbines, etc. A lot of this equipment is in the 100-130 dB range when 10-30 feet away.
  
 I would often even double up hearing protection in the noisiest environments, using both the expandable foam type ear plugs, as well as the over-the-ears type muffs. Even so, it could be quite noisy. Sometimes when time was of the essence, I would go near equipment for a time without any protection. I know, bad idea, but at those times it was to get the job done quickly, or to prevent process upsets or get into production more quickly. When you're 25, I guess you don't think about the impact many years down the road.
  
 Anyway, the damage done is pretty much irreversible at this point. When laying down at night to go to sleep in a fairly quiet atmosphere I can hear a tone that seems to be coming from inside my head. It has been that way for at least ten years now, and I have become somewhat accustomed to it. Fortunately, I am still able to enjoy my music, both through headphones and loudspeakers. Maybe not as much as if I didn't have the tinnitus, but I'm thankful for the enjoyment that I still am able to experience.  
  
 I guess what should be taken from this, is that although hearing protection can't entirely shield you from high noise environments, it is important to take the best precautions that are available to preserve your hearing.


----------



## Loquah

sp wild said:


> I guess your wink was directed at my tendency to wade into a thread, totally OT after lurking and finding a post I could comment on with personal experience?  Then again I don't think it is totally off track, if it this that prompts me to engage in communication with members of more experience.  Mainly, I've been lurking because 300b amps are raved about, and the most affordable iteration is the Bottlehead unit.
> 
> This sterilised version of head-fi has me a little concerned.  Nevertheless, I shall be on my merry way in search for more information to help make my next big ticket item purchase decision....a glowing sweet botlle of music.  Nedd to put words into action, have been speaking of this purchase forever but never quite committed, an integrity thing for me, one must do what one says one will do.


 
  
 Oh, no it wasn't - sorry if it seemed that way. I was joking about the fact that my last few posts had been way OT and I was feeling guilty so I found a sneaky link back to the topic. One of the things I love about this thread (and *most* of Head-Fi) is the willingness of members to discuss relevant, but sometimes tangential, topics. I hope I didn't make you feel censored at all as I enjoyed your post and found your experiences very interesting.


----------



## Sonido

> I wanna know if anybody has used the crack as a preamp?  Am tossing between an all out 300b bottle head for speakers or a tube preamp.  It doen't help after listening to my HD650s on the reference rig and realising that its too good a headphone to not give it the amp it needs to shine.


 
 The Crack can work as a preamp, but I would think the Smash or even Quickie would be better as a preamp. Actually pretty sure somewhere on their website they say the Quickie is better as a preamp than Crack. If you're only looking for preamp use, the new Smash is about the same price as Crack+Speedball. If you want both a headphones amp and a preamp, then maybe get Crack. Since you're into the 300B, I'm sure you've given the BeePre a look. The Smash is supposed to be trickle down technology of the BeePre, but no 300B tube. After hearing the Smash in my chain, I too am thinking about the BeePre.


----------



## SP Wild

loquah said:


> Oh, no it wasn't - sorry if it seemed that way. I was joking about the fact that my last few posts had been way OT and I was feeling guilty so I found a sneaky link back to the topic. One of the things I love about this thread (and *most* of Head-Fi) is the willingness of members to discuss relevant, but sometimes tangential, topics. I hope I didn't make you feel censored at all as I enjoyed your post and found your experiences very interesting.


 

 Aha, so we are more alike than different.  I did feel a little like you might be having a go....but I'm a little edgey on this matter, because I have a history and tendemcy to OT discussions, and you wouldnt be the first to pick me out on that one.
  
 But y'know, changing is SOO hard, especially when you know for a fact that this personality flaw is totally harmless in the bigger scheme of things.
  
 So how about that 300b hey?


----------



## SP Wild

sonido said:


> The Crack can work as a preamp, but I would think the Smash or even Quickie would be better as a preamp. Actually pretty sure somewhere on their website they say the Quickie is better as a preamp than Crack. If you're only looking for preamp use, the new Smash is about the same price as Crack+Speedball. If you want both a headphones amp and a preamp, then maybe get Crack. Since you're into the 300B, I'm sure you've given the BeePre a look. The Smash is supposed to be trickle down technology of the BeePre, but no 300B tube. After hearing the Smash in my chain, I too am thinking about the BeePre.


 
  
 WOW, so many new product lines since I last looked, Ima go and check out the bottlehead site, to um, fill in the cracks.


----------



## Loquah

Yeah, there are heaps and that's not even mentioning the new D-Class amp (designed to pair with Quickie) and hopefully upcoming DAC.


----------



## SP Wild

Well if there is one thing that sways me to the bottlehead gear is the DIY factor.  I know once I've diyed something I have no fear to tear it down and improve upon it, because I understand the schematic and the process of each component.  I'd also hope that the sound quality for the price is excellent due to the diy factor.


----------



## Loquah

sp wild said:


> Well if there is one thing that sways me to the bottlehead gear is the DIY factor.  I know once I've diyed something I have no fear to tear it down and improve upon it, because I understand the schematic and the process of each component.  I'd also hope that the sound quality for the price is excellent due to the diy factor.


 
  
 Yes and yes.
  
 Also, there's that certain connection you create with a piece of gear when you personally assembled and tested it. I find it very easy to part with things I've bought, but it's decidedly harder with things I've built. Not sure if that's a good thing or a bad thing...


----------



## SP Wild

loquah said:


> Yes and yes.
> 
> Also, there's that certain connection you create with a piece of gear when you personally assembled and tested it. I find it very easy to part with things I've bought, but it's decidedly harder with things I've built. Not sure if that's a good thing or a bad thing...


 

  Probably a good thing, because you don't have an ISO9001 certification (or whatever international standard).  Nah, that doesn't really matter for non commercial ventures....for me I have a problem with parting away with stuff...because of my slight tendency to hoard stuff...except for headphone stuff, I am an outright hoarder...


----------



## Deterministic NL

listen4joy said:


> my crack+speedball is on the way. i want to put best tubes. i heard the sophia among the best
> 
> http://www.sophiaelectric.com/
> 
> can you tell me from this site what will be suit for crack?


 
  
 Just the 12AU7.  Nothing I saw on that site for the 6080 tube or any of it's variants.


----------



## Deterministic NL

deterministic nl said:


> Just the 12AU7.  Nothing I saw on that site for the 6080 tube or any of it's variants.


 
 And I should have added. I have some Sophia Electric 2A3 tubes I bought years ago when I was in Washington D.C.  Owner of the company brought them to my hotel and I hand carried them back home to Japan.  Great tubes.  They are actually installed in my Bottlehead Paramour amps now as we speak.  I roll between old RCA 2A3's and the Sophia tubes depending on mood.  Love the look of those big mesh plates in the dark as well.


----------



## Doc B.

sp wild said:


> Firing guns taught me something about physiology and hearing.  Sighting a rifle with hearing protection on is a terrifying experience for me.  But out in the field, firing a rifle after sprinting for your prey, without protection (can't stalk if you can't hear), it sounds more like back round noise.  Could easily start critiquing the sound quality of various rifles, shotguns and ammo.
> 
> Its weird, when thoroughly warmed up, no ringing, no issues and apparently no pain.  But cold with protection and its terrifying.  I wonder if adrenaline can protect your hearing for short moments.  Firing a rifle in the field is actually a rare occurence, a clean shot can be very hard, try holding a rifle or shotgun still after sprinting.
> 
> But that is not why I am here.  I wanna know if anybody has used the crack as a preamp?  Am tossing between an all out 300b bottle head for speakers or a tube preamp.  It doen't help after listening to my HD650s on the reference rig and realising that its too good a headphone to not give it the amp it needs to shine.


 
 Boy that is really interesting. I have never hunted anything bigger than rats, but I have put a lot of lead downrange in years past. I absolutely hate the report of a firearm without muffs. But I could and did shoot for hours at a time doubled up with in-ear plugs and muffs. What terrified me was usually some idiotic rube next to me on the firing line waving his gun around or playing with it while shooters were downrange. The things I suggest to anyone who shoots at a range and wants to try to preserve their hearing as much as possible is don't shoot firearms with ported barrels, and if you have a firearm that can use it shoot subsonic ammo. Supersonic ammo and ported barrels send shock waves right through your facial bones and because of that muffs can only protect you so much.


----------



## Sonido

Taking my Crack from work back to home tonight to try out the Smash+Crack pairing.


----------



## cheneric

What's the best way to package the amp securely for shipping?


----------



## Sonido

@Doc B.
  
 The pairing of Smash+Crack is working out pretty well. I don't want to spoil much on it here until the tubes in the Smash are properly burned in. Have you had the chance to try the BeePre into the Mainline with the HD800? If you have, how is it? I'd imagine the BeePre to be an upgrade over the Smash and the Mainline an upgrade over Crack.


----------



## MattTCG

sonido said:


> Taking my Crack from work back to home tonight to try out the Smash+Crack pairing.


 
  





...


----------



## Sonido

After some comparisons with Smash and no Smash in chain, I can conclude that has the same effect on the Crack as it did with my Questyle. What that effect is will be revealed in due time.


----------



## SP Wild

doc b. said:


> Boy that is really interesting. I have never hunted anything bigger than rats, but I have put a lot of lead downrange in years past. I absolutely hate the report of a firearm without muffs. But I could and did shoot for hours at a time doubled up with in-ear plugs and muffs. What terrified me was usually some idiotic rube next to me on the firing line waving his gun around or playing with it while shooters were downrange. The things I suggest to anyone who shoots at a range and wants to try to preserve their hearing as much as possible is don't shoot firearms with ported barrels, and if you have a firearm that can use it shoot subsonic ammo. Supersonic ammo and ported barrels send shock waves right through your facial bones and because of that muffs can only protect you so much.


 
  
 Ahhh, the good Doctor himself...the one with the cure to my addiction.  Great points, next time I'm at the range will obtain ear plugs and muffs to double up on the protection.  I think when one sees a gun for what it really is, an instrument designed for no other purpose but to cause death, I think this education could go a long way to avoiding idiots waving a gun barrel willy nilly.  Never ceases to amaze me that the first thing a person does when I let them hold my rifles, with no ammo and bolt, is to point it directly at someone in jest.  For me a gun was the natural progression from my fishing rods and connects me even more to the natural order...and much like how tube amps connect me more to the natural order of sounds.


----------



## kothganesh

sp wild said:


> Ahhh, the good Doctor himself...the one with the cure to my addiction.  Great points, next time I'm at the range will obtain ear plugs and muffs to double up on the protection.  I think when one sees a gun for what it really is, an instrument designed for no other purpose but to cause death, I think this education could go a long way to avoiding idiots waving a gun barrel willy nilly.  Never ceases to amaze me that the first thing a person does when I let them hold my rifles, with no ammo and bolt, is to point it directly at someone in jest.  For me a gun was the natural progression from my fishing rods and connects me even more to the natural order...and much like how tube amps connect me more to the natural order of sounds.


 
 How about a gun with tubes ! Now that's convergence!


----------



## SP Wild

Right...and the barrel also acts like an impedance matching device to the ears...the trigger obviously starts the music.  But it wouldnt work because of tube microphonics, now that the gun is now an MP3 player and killing device.  I'm afraid only solid state devices could fulfill this glaringly obvious, yet uncatered for market.


----------



## Armaegis

cheneric said:


> What's the best way to package the amp securely for shipping?


 
  
 - pull out the tubes and wrap them up
 - thoroughly tape down the plate to the base (something that comes off easily _without residue_, like painter's tape)
 - if there's space, tuck the tubes carefully snug inside the case somewhere, adding padding and tape as necessary *be super careful not to push the wires or components when you do so... or skip to the ^ two steps below
 - wrap the nontransformer end of the amp tightly in bubblewrap or foam packaging stuff, then tape that sucker down (wrap end over end with packaging tape to really secure it in case the painter's tape fails)
 - wrap lengthwise over the transformer now with more bubblewrap or foam sheets; ^ if you didn't fit the tubes inside the case, you might tuck them sidewise here next to the transformer then tape 'em down
 - gently see if the plate wants to lift off the base. If so, you didn't secure everything tightly enough!
 - put the whole thing in a box, stuff all sides and top firmly so it doesn't slide around; I'd even put an extra sheet of thick cardboard on the bottom (I actually used a flap from a broken binder/folder) in case something stupid happens
 + alternatively you can also put the amp in the box upside down to take pressure off the caes in case of drops, and I recommend putting a small block of foam or newspapers at the other end to hold it somewhat level. Then you can tuck the tubes underneath. I still recommend a thick cardboard under everything, and another on "top" to cover the base (I have had stupid bad luck with the post office smashing things)
 - photocopy the parts list and put it in there; if USPS screws things up and breaks something, you'll want that in there
 - don't forget that power cord
 - tape up the box, wrap in paper, tape up some more


----------



## Armaegis

Slightly updated my post above.


----------



## ModestMeowth

Does anyone have directions on how to wire a Valab stepped pot?


----------



## i luvmusic 2

Can i use this  for the Crack?Thanks!


----------



## Loquah

If it's dual channel and 100k as it says it is then yes, you can.
  
 If I remember correctly you need to bridge the ground connectors as well (ie a short cable from left ground to right ground)
  
 This would be true for the Valab question above, too. For more guidance we might need a picture though.


----------



## i luvmusic 2

loquah said:


> If it's dual channel and 100k as it says it is then yes, you can.
> 
> If I remember correctly you need to bridge the ground connectors as well (ie a short cable from left ground to right ground)
> 
> This would be true for the Valab question above, too. For more guidance we might need a picture though.


 
     Yes it's Dual as per the seller and by looking at the picture above the two grounds are connected to each other(Shorted/bridged)
 I got soo excited when i ordered my crack then i ordered the attenuator but i did not really pay attention to what it looks like i just ordered DUAL 100K but when i received it today and look at some pictures from the BH forum all i see is defferent than what i have.Thank You!


----------



## Loquah

i luvmusic 2 said:


> Yes it's Dual as per the seller and by looking at the picture above the two grounds are connected to each other(Shorted/bridged)
> I got soo excited when i ordered my crack then i ordered the attenuator but i did not really pay attention to what it looks like i just ordered DUAL 100K but when i received it today and look at some pictures from the BH forum all i see is defferent than what i have.Thank You!


 
  
 I know the feeling! It does look different because most of them are deeper. Perhaps this is a more compact way to do it.
  
 Just double check the bridging of the earth because I can't see it in the pictures (other than the blue line pointing to the two earth pins) and it shouldn't have come bridged because not all systems work that way. If in doubt, make your own bridging connection because 2 won't hurt, but not having one will.


----------



## i luvmusic 2

loquah said:


> i luvmusic 2 said:
> 
> 
> > Yes it's Dual as per the seller and by looking at the picture above the two grounds are connected to each other(Shorted/bridged)
> ...


 
 Sorry i mean i need to bridged them in the picture it only show where to connect/bridged them.Thanks!


----------



## i luvmusic 2

My Crack should be shipping with in this week or next week as per Queen.I'am Sooooooo excited........


----------



## JamieMcC

modestmeowth said:


> Does anyone have directions on how to wire a Valab stepped pot?


 
  
 I think some of the newer Valabs have a screw connectors mine is the solder in type the pic below shows how mine is connected up its important to wire bridge between the left and right channel grounds (black wires in the middle) for safety and to reduce noise.


----------



## spacequeen7

i luvmusic 2 said:


> Can i use this  for the Crack?Thanks!


 
 I think this is mono attenuator buddy ,I hope I'm wrong


----------



## Loquah

spacequeen7 said:


> I think this is mono attenuator buddy ,I hope I'm wrong


 
  
 I did wonder about that as well, but I'm likewise hoping for i luvmusic 2 that the seller has been honest with their description! There are clearly two banks of resistors which is a good sign, but on the stereo attenuators I've seen and used, there are two banks each with matching pairs of resistors!?


----------



## EraserXIV

I also just got a stepped attenuator recently and it appears I need to widen the hole in the top plate to fit the whole thing through correctly. Would I be able to do this with a dremel?


----------



## Loquah

eraserxiv said:


> I also just got a stepped attenuator recently and it appears I need to widen the hole in the top plate to fit the whole thing through correctly. Would I be able to do this with a dremel?


 
  
 Yes. That's how I do it. I found the best option was the bit that has a cylindrical section at the tip with cutting edges at the end and on the sides. Not sure the correct terminology for it, but I think it's designed for carving / reaming.


----------



## EraserXIV

loquah said:


> Yes. That's how I do it. I found the best option was the bit that has a cylindrical section at the tip with cutting edges at the end and on the sides. Not sure the correct terminology for it, but I think it's designed for carving / reaming.


 
  
 Thanks, will these get the job done? http://www.amazon.com/pieces-Tungsten-Carbide-Single-Rotary/dp/B00C9BI1CM/ref=sr_1_1?ie=UTF8&qid=1404956283&sr=8-1&keywords=tungsten+carbide+dremel


----------



## Loquah

Spot on. The right hand end ones are the ones I was talking about. I'm not sure if they are strictly the best option, but they seemed to do the best of all the options I had and made short work of enlarging the Crack's stock volume pot hole.


----------



## Armaegis

I just feel like chiming in for those considering doing dremel work. Spend the extra coin on decent bits. The cheap bargain bin ones that come 40 to a set will only cause you grief and mess up your project.


----------



## Aeolus Kratos

I'm proud to be a Bottlehead fan 
	

	
	
		
		

		
		
	


	



  
  

  

  
  
 The new DHT SMASH preamp sounded really awesome with the S.E.X and the Crack, now my Quickie is collecting dust on the shelf


----------



## dsound

aeolus kratos said:


> I'm proud to be a Bottlehead fan


 
  
 +1.  My HD600 + Crack have left me with no desire to upgrade my open-backed setup in the near future.
  
 P.S. I love my Orca's, how do you like yours?


----------



## guildenstern

aeolus kratos said:


> The new DHT SMASH preamp sounded really awesome with the S.E.X and the Crack, now my Quickie is collecting dust on the shelf


 
 Very interested in the SMASH. I'm not familiar with the 4P1L tubes it uses.
  
 When you use the SMASH to drive the S.E.X. (um, that sounds a little weird...), do you just set the volume control on the S.E.X. to max?
  
 I too own the Blumenstein Orcas. Amazing what comes out of those little boxes! Looks like you also have the sub -- like it?


----------



## RonO

More Bottlehead goodness.  Quickie and Crack combo, just put Alps POTS in both.  It especially works well in the Quickie, it had real imbalance issues:
  

  
 I feel like I won the lottery getting a white top for the Quicke,  Thanks to MattTCG for fabricating the box for the Quicke, it's too nice sitting next to my all Black Crack.
  
 RonO


----------



## i luvmusic 2

spacequeen7 said:


> i luvmusic 2 said:
> 
> 
> > Can i use this  for the Crack?Thanks!
> ...


 
 Now you got me thinking let me asked the vendor,If this is Dual MONO can i still used it would it still be a good choice for the Crack?Sorry i'am new to this Electronics stuff.THANK YOU!


----------



## i luvmusic 2

I just double checked my order for this attenuator and email the seller if this is MONO or STEREO.
 The product description is (please see below)Thanks!
 I hope this is a real STEREO.
  
  
Assembled DALE 23 Step Attenuator
*             **1pc Dual 100K, Knurled Shaft*
*                 Airproof Rotary Band Switch, Silver Coated Contact *
*                   Assembled all Resistors are Genuine brand DALE                   *
*                             Shaft Length 25mm, Diameter 6mm*   
               *23 Step Volume Attenuator, Dual-unit for Stereo Audio *


----------



## Loquah

i luvmusic 2 said:


> I just double checked my order for this attenuator and email the seller if this is MONO or STEREO.
> The product description is (please see below)Thanks!
> I hope this is a real STEREO.
> 
> ...


 
  
 It DOES say it's the right thing, but just looks so different. I don't think it can hurt to try it - if it's wrong, things will just sound weird I believe. I'd contact the seller to confirm in writing that it's stereo and then hook it up and see. If it's not you can ask for a replacement with his confirmation as proof that you were supplied the wrong thing and tried to check before soldering.
  
 Ideally, you could maybe use some alligator clips or some temporary method to hook it up for testing so there's no sign of soldering if you have to return it.


----------



## QRomo

I'm surprised no one else has pointed this out, but from the picture it looks like it's a two-channel series stepped attenuator. See here for a description of the different types.


----------



## i luvmusic 2

loquah said:


> i luvmusic 2 said:
> 
> 
> > I just double checked my order for this attenuator and email the seller if this is MONO or STEREO.
> ...


 
 I don't have my Crack yet i'am still waiting for shipping i guess  have to wait and see if it's a Dual Stereo.Thanks!


----------



## i luvmusic 2

qromo said:


> I'm surprised no one else has pointed this out, but from the picture it looks like it's a two-channel series stepped attenuator. See here for a description of the different types.


 
 I just checked the resistors connections they are in series thank You for pointing that out.


----------



## i luvmusic 2

Ok i've got a reply from the attenuator seller he confirmed that the attenuator he send me is a DUAL STEREO(Resistors are connected in series for stereo mode)according to him MONO mode usually connected in parallel which is he does not sell.Is this make sense?


----------



## benjaminhuypham

aeolus kratos said:


> I'm proud to be a Bottlehead fan
> 
> 
> 
> ...


 
  
 Wow, beautiful setup with full of Bottlehead amps. I'm not really sure what preamplifier does? Does it improve sound quality significantly as a DAC?


----------



## Sonido

benjaminhuypham said:


> Wow, beautiful setup with full of Bottlehead amps. I'm not really sure what preamplifier does? Does it improve sound quality significantly as a DAC?


 
 In my experience, it can do two things.
  
 1. Impart it's own sound signature to the chain. For example the Quickie does this by adding a kick to the lower frequencies. Tubes preamps are especially known to add warmth to the sound. This can be good when pairing with a colder sounding solid state amp. Purist will hate on this though since it deviates from the source.
  
 2. It can clean up the sound. This is done by putting less strain on the DAC by increasing the gain somewhat before feeding it into an amp. It's an intermediary to help match impedance values. I've found the Smash to do this more than the previous point. Smash to me is very neutral, but the improvements are in details, imaging, and soundstaging. Overall the music just sound less compressed or cluttered.


----------



## Aeolus Kratos

dsound said:


> +1.  My HD600 + Crack have left me with no desire to upgrade my open-backed setup in the near future.
> 
> P.S. I love my Orca's, how do you like yours?


 
 Me too! The Orcas sound is very transparent, detailed and neutral. I've been surprised by how these beautiful little box can be!
  


guildenstern said:


> Very interested in the SMASH. I'm not familiar with the 4P1L tubes it uses.
> 
> When you use the SMASH to drive the S.E.X. (um, that sounds a little weird...), do you just set the volume control on the S.E.X. to max?
> 
> I too own the Blumenstein Orcas. Amazing what comes out of those little boxes! Looks like you also have the sub -- like it?


 
 Hi guildenstern,
  
 What I think even weirder is that the SMASH can cause a big distortion driving the Mainline. The distortion was even louder than when you plugged the planars/ortho like the HE-500s to the Crack. The music from SMASH + Mainline is not listenable at all. Surprisingly, the SMASH was fantastic with either the Crack or the SEX.
  
 When I use the SMASH with the SEX, I set the SEX volume to approximately 50% ( i.e 12h direction ) and control the volume via the SMASH, same to the Crack.
  
 Yes! I totally love the Orcas! The sub really adds a great depth to the bass and helps create a deeper and more 3d soundstage to the overall presentation.
  


benjaminhuypham said:


> Wow, beautiful setup with full of Bottlehead amps. I'm not really sure what preamplifier does? Does it improve sound quality significantly as a DAC?


 
 Thanks Benjamin! I'm now having two main setups : I use the SMASH + S.E.X + Orcas speakers combo as I pictured above for speaker setup and this wonderful headamp for critical headphone listening, so I can have the best of both worlds


----------



## Sonido

aeolus kratos said:


> What I think even weirder is that the SMASH can cause a big distortion driving the Mainline. The distortion was even louder than when you plugged the planars/ortho like the HE-500s to the Crack. The music from SMASH + Mainline is not listenable at all. Surprisingly, the SMASH was fantastic with either the Crack or the SEX.


 
 The Crack and SEX has input impedances of 100K ohms, whereas the Mainline only has 25K ohms input impedance. Still with a 1.6k ohms output impedance, that ratio isn't terrible with the Mainline. Perhaps less headroom. I'm using it with my Questyle amp that has an input impedance of 47K ohms, and it sounds fine, though I do find I can't turn the volume on the Smash past 60% or distortions start appearing. I do note that headroom for my setup could be better. Right now I have the Questyle at 1 o'clock and the Smash at 12 o'clock to get to decent listening levels (~80 dB), with 7 o'clock being the starting point on both. Doc B. has told me that the BeePre has better headroom than the Smash, and its output impedance is only 500 ohms, so maybe that has something to do with it.


----------



## liamstrain

A pre-amplifier is often a source selector, and then used as another place for volume control. Whether it improves sound varies widely. I like them for convenience.


----------



## Doc B.

I am hesitant to intrude upon this, as I am very happy to sell everyone both a headphone amp a preamp. But I feel compelled to say that putting a Smash ahead of a Mainline is counterproductive. We did not design that gear to work together. The Mainline is a standalone headphone amp designed to be connected directly to a source component. For that matter so are the S.E.X. and Crack amps. But they have a couple of gain stages and a higher input impedance so one is not really going against a fundamental design point by putting more tubes ahead of them like you are with the single gain stage Mainline. If it was distorting it's probably because the Smash was being driven hard by the source and the bass was crapping out into the relatively low impedance of the Mainline. Also, the stock Mainline volume control is quite a bit more esoteric and sounds better than the stock Smash volume control ( which will be upgradeable to a similar state with the BeeQuiet kit soon) so why put the extra volume pot in the chain?

The Quickie and Smash are really designed for power amps like our Paramount and Quicksand amps, and also the new midline tube amp design we are developing. My hunch is what you guys are doing is making sort of a buffer stage for your source components by putting them in between. I think that's reasonable for a Crack or S.E.X. Based system, but I would suggest getting a better source component to match the Mainline if you feel the existing one needs some help.

My most cost effective suggestion if you want to experiment with this preamp stuff is get some nice inefficient planars and try a Quickie/Quicksand combo to drive them.


----------



## Sonido

doc b. said:


> I am hesitant to intrude upon this, as I am very happy to sell everyone both a headphone amp a preamp. But I feel compelled to say that putting a Smash ahead of a Mainline is counterproductive. We did not design that gear to work together. The Mainline is a standalone headphone amp designed to be connected directly to a source component. For that matter so are the S.E.X. and Crack amps. But they have a couple of gain stages and a higher input impedance so one is not really going against a fundamental design point by putting more tubes ahead of them like you are with the single gain stage Mainline. If it was distorting it's probably because the Smash was being driven hard by the source and the bass was crapping out into the relatively low impedance of the Mainline. Also, the stock Mainline volume control is quite a bit more esoteric and sounds better than the stock Smash volume control ( which will be upgradeable to a similar state with the BeeQuiet kit soon) so why put the extra volume pot in the chain?
> 
> The Quickie and Smash are really designed for power amps like our Paramount and Quicksand amps, and also the new midline tube amp design we are developing. My hunch is what you guys are doing is making sort of a buffer stage for your source components by putting them in between. I think that's reasonable for a Crack or S.E.X. Based system, but I would suggest getting a better source component to match the Mainline if you feel the existing one needs some help.
> 
> My most cost effective suggestion if you want to experiment with this preamp stuff is get some nice inefficient planars and try a Quickie/Quicksand combo to drive them.


 

 Thanks for the explanation Doc! The BeePre is in my sights. I'm thinking of getting a second Questyle CMA800R to go dual monoblock balanced, and with that setup, you need a preamp to control volume because the volume pots on the Questyles in that setup aren't being used. Also need 3-pin XLR out from the preamp to feed this setup, and I believe the BeePre has that.
  
 Also that's translation for the rest of you Crack owners on here to go and pick up the Quickie or Smash, or better yet the BeePre.


----------



## Nic Rhodes

Sounds like you should also develop a buffer kit Doc.


----------



## Loquah

nic rhodes said:


> Sounds like you should also develop a buffer kit Doc.


 
  
 Stop giving him ideas - we'll all go broke!


----------



## Armaegis

doc b. said:


> Based system, but I would suggest getting a better source component to match the Mainline if you feel the existing one needs some help.
> 
> My most cost effective suggestion if you want to experiment with this preamp stuff is get some nice inefficient planars and try a Quickie/Quicksand combo to drive them.


 
  
 Of course, there's the bottlehead dac in development... very curious to hear more news on that as it develops.


----------



## Merloobi

This is probably the wrong place to ask, but is anyone looking to sell their Bottlehead Crack + Speedball? I'm very interested in getting my hands on one, but the costs of buying soldering tools is impeding me. I've heard the build is noob friendly, but the whole process sounds very daunting and I don't want to take a risk after investing ~$500 in parts and tools. Thanks.


----------



## jgreen16

merloobi said:


> This is probably the wrong place to ask, but is anyone looking to sell their Bottlehead Crack + Speedball? I'm very interested in getting my hands on one, but the costs of buying soldering tools is impeding me. I've heard the build is noob friendly, but the whole process sounds very daunting and I don't want to take a risk after investing ~$500 in parts and tools. Thanks.


 
 There is a For Sale section for Phones, sources, amplification, etc.
  
 Check here, I think there were a couple the last time I looked:
  
http://www.head-fi.org/f/6551/amplification-for-sale-trade


----------



## Merloobi

jgreen16 said:


> There is a For Sale section for Phones, sources, amplification, etc.
> 
> Check here, I think there a couple the last time I looked:
> 
> http://www.head-fi.org/f/6551/amplification-for-sale-trade


 
 Thanks for your response. I will take a look there!


----------



## olegausany

I have moded one for sale


----------



## Loquah

merloobi said:


> This is probably the wrong place to ask, but is anyone looking to sell their Bottlehead Crack + Speedball? I'm very interested in getting my hands on one, but the costs of buying soldering tools is impeding me. I've heard the build is noob friendly, but the whole process sounds very daunting and I don't want to take a risk after investing ~$500 in parts and tools. Thanks.


 
  
 Where in the world are you located?


----------



## MattTCG

There are lot's of crack for sale in the forum right now. More than I've ever seen.


----------



## Merloobi

loquah said:


> Where in the world are you located?




I'm located in the North Texas (Dallas), USA


----------



## Armaegis

One sold at a high price not too long ago, and now people are jumping on the bus hoping to get the same value, without realizing how much work the original seller put in to his version.


----------



## JamieMcC

There was a offer on a little while back that was heavily subscribed but we are not allowed to mention the site or the Head-fi pc brigade come and delete the posts. I expect some Crack owners took advantage after all who wouldn't want to build one again its great fun.


----------



## Doc B.

Yeah, I am kind of amazed at the number of repeat offenders, I mean returning customers we have for Crack. We have several customers who have bought three or four Crack kits and many who have bought at least two. It seems that some build them to give as gifts and I suppose a few build them to sell. The number of kits sold has gone up tremendously in the past year. So there are bound to be some more around for sale because of the sheer number of them out there. It's interesting to go through various forum threads and find a post here and there where someone built a Crack, sold it, regretted it and bought another Crack kit. 

My take has always been that you are only experiencing half the fun if you don't build your own kit. Plus, one that you built yourself always sounds better.


----------



## guildenstern

armaegis said:


> - pull out the tubes and wrap them up
> - thoroughly tape down the plate to the base (something that comes off easily _without residue_, like painter's tape)
> - if there's space, tuck the tubes snugly inside the case somewhere, adding padding and tape as necessary
> - wrap the nontransformer end of the amp tightly in bubblewrap or foam packaging stuff, then tape that sucker down (wrap end over end with packaging tape to really secure it in case the painter's tape fails)
> ...


 

 The packing suggestions above are generally in accord with what Bottlehead recommends except for one important exception -- the suggestion to "tuck the tubes snugly inside the case somewhere" is exactly the wrong thing to do, because anything stuffed inside the case can press against the wires and components, and break a connection during shipping.
  
 Also, BH recommends that, once you have the amp safely wrapped and generously padded, you put it in the shipping box upside-down, with the top of the transformer facing down. They suggest this so that the main plate of the amp is not stressed by the weight of the transformer if the amp is dropped during shipping.


----------



## Armaegis

guildenstern said:


> The packing suggestions above are generally in accord with what Bottlehead recommends except for one important exception -- the suggestion to "tuck the tubes snugly inside the case somewhere" is exactly the wrong thing to do, because anything stuffed inside the case can press against the wires and components, and break a connection during shipping.


 
  
 That's a fair point, and I've edited my original post to reflect that. I've shipped three Cracks now and haven't had any issues, but always take extra precaution. (I did have one arrive with broken solder joints, but they weren't anywhere near where I had the tubes)
  
 My reasoning was that a glass tube is safer in the case than not... but yeah, care must be taken to not smush against the components inside if you do so. If a postal worker puts a forklift through your packaging, well a broken tube is probably the least of your worries.


----------



## JamieMcC

My Crack defected to the east last week.
  
 Comrade Crack is now sporting 3x30uf Russian paper in oil capacitors in each channel with 0.056uf Teflon by-
 passes.


----------



## Armaegis

Did you manage to fit those in the chassis?


----------



## JamieMcC

armaegis said:


> Did you manage to fit those in the chassis?


 
  
 My chassis is a little larger than standard and I have my connections set up for easily swapping output caps its something I have been experimenting with for the last six months. They they will go in a standard chassis but you need to be creative like Geary has been with his Crack in these pics he has even squeezed in a choke! I had been curious about trying them out after seeing his build when he helped me with installing the choke on my Crack


----------



## Loquah

That's awesome! A Crack Stack


----------



## i luvmusic 2

All this CRACK talking makes me drool i can't wait for mine.


----------



## Merloobi

doc b. said:


> Yeah, I am kind of amazed at the number of repeat offenders, I mean returning customers we have for Crack. We have several customers who have bought three or four Crack kits and many who have bought at least two. It seems that some build them to give as gifts and I suppose a few build them to sell. The number of kits sold has gone up tremendously in the past year. So there are bound to be some more around for sale because of the sheer number of them out there. It's interesting to go through various forum threads and find a post here and there where someone built a Crack, sold it, regretted it and bought another Crack kit.
> 
> My take has always been that you are only experiencing half the fun if you don't build your own kit. Plus, one that you built yourself always sounds better.


 
 I really want to try building one, but the cost of tools is turning me away since I would only use it for the Crack build. Too many things could go wrong for me and frankly, I like to buy used equipment. Each piece has a bit of history and its own story.


----------



## i luvmusic 2

I was like that before but once i experienced building/modifying one of my amp actually all of my amps it's difficult for me to stop now i'am stepping into the CRACK build Territory god only knows what is next for me
	

	
	
		
		

		
		
	


	




. IMHO buy the tools and build your own CRACK have fun and enjoy.......
	

	
	
		
		

		
		
	


	




. 
   Tools i have are Weller soldering station with a spare tip,Desoldering tool,Needle nose Plier,Side/Diagonal Cutter and a Digital Multimeter as far as i remember i paid CAD $150 for all of these tools that is not much compared to paying someone building stuff for you.


----------



## Merloobi

To be completely honest, I'm trying to look for good value by buying second hand. Some of the builds I have seen here are spectacular. If nothing works out I will take the plunge and build my own. 
  
 Somewhat related, I was looking at a DAC to pair with the Crack and saw that the FiiO E10k just came out. Obviously since it brand new, its tough to make a call, but would it do the Crack justice? Also I noticed that it doesn't have RCA out. Would I be hindering its performance by using a 1/8" to RCA cable to hook it up to the Crack? Otherwise I was thinking about using the JDS labs ODAC w/ RCA out instead. Are there any other good alternatives in the ~$100 range for DACs? I've heard that anything >=$100 will perform about the same. 
  
 Thanks!


----------



## EraserXIV

What kind of connectivity do you need? I assume just USB since you were considering the E10K?
  
 Take a look at the iFi iDSD Nano, that thing has no business sounding as good as it does for that price. They occasionally pop up on the For Sale forum for cheaper and on MusicDirect as 'open-box demos' for around $160.


----------



## jgreen16

Schiit Modi. And it has the RCA outs. Hard DAC to beat for the price.


----------



## liamstrain

FWIW - 1/8th to RCA cable won't affect the sound, unless it's put together poorly. 
  
 The ODAC is an excellent option, imo. As is the AMB Gamma1 or Gamma 2. If you are building your own, they are well within budget. Having them built will probably push you over a bit, though.


----------



## Merloobi

eraserxiv said:


> What kind of connectivity do you need? I assume just USB since you were considering the E10K?
> 
> Take a look at the iFi iDSD Nano, that thing has no business sounding as good as it does for that price. They occasionally pop up on the For Sale forum for cheaper and on MusicDirect as 'open-box demos' for around $160.


 
  
 Yes, I am using a USB source.
  
 I really like your suggestion, the iFi iDSD Nano looks perfect for my needs. Its outputs and portable nature are exactly what I'm looking for. Thanks so much.


jgreen16 said:


> Schiit Modi. And it has the RCA outs. Hard DAC to beat for the price.


 
  
 I originally had a Modi, but it was a bit too blocky for my liking. However I do agree; it has incredible value!
  


liamstrain said:


> FWIW - 1/8th to RCA cable won't affect the sound, unless it's put together poorly.
> 
> The ODAC is an excellent option, imo. As is the AMB Gamma1 or Gamma 2. If you are building your own, they are well within budget. Having them built will probably push you over a bit, though.


 
  
 Thank you for your answer. I thought the ODAC was very attractive, however, for the same price as the iFi iDSD Nano, its limited output and and controls doesn't make it as attractive.
  
  
  
 I would like to thank everyone who has helped me and answer all my questions. I'm a relatively new member who posted in the wrong section, but was only met with friendly advice. What a great community!


----------



## FlySweep

@Aeolus Kratos.. you've got my custom built Crack, man!  All the way down to the BlueJeansCables RCA and BH power cord.. sweet.. glad it landed in good hands!  Hope you're enjoying it.. it's a badass rig.. I miss it.


----------



## Aeolus Kratos

flysweep said:


> @Aeolus Kratos.. you've got my custom built Crack, man!  All the way down to the BlueJeansCables RCA and BH power cord.. sweet.. glad it landed in good hands!  Hope you're enjoying it.. it's a badass rig.. I miss it.


 

 Hi FlySweep,
  
 Haha, how do you know I've got your Crack? I'm really loving it! It was truly superior to my previous speedballed Crack ( which doesn't have all the capacitor and attenuator upgrades ), thank you very much! 
	

	
	
		
		

		
			




  
 BTW, I'm not sure what the driver tube you included is, the box says 'Tung-sol 12AU7 ECC82 Long Black Plate', but the brand name was all 'faded out' on the glass, and the plate is somehow not really 'black', it's kind of grey-black. Here are some pics of the tube I received:
  

  

  

  

 To the left is a RCA Cleartop, the plate of the 'Tung-sol' is somehow 'darker' than the RCA. But I can't call it totally 'black', so I'm not sure. It sounds great, though.


----------



## audiowize

FYI - when you see the tube type enclosed by an octagon, the tube was made by RCA.


----------



## FlySweep

aeolus kratos said:


> Spoiler: Warning: Spoiler!
> 
> 
> 
> ...


 
  
 How do I know?  Hmm.. I've just got a feeling.  
	

	
	
		
		

		
		
	


	




.  The input tube I sent with the sale (can't remember who it was sold to off the top of my head, atm) was the Tung Sol "black/gray plate" 12AU7 you pictured.. even sent in that box (that's a big time tube, btw.. one of the best 12AU7s I've heard).. and the cables I included were those cables pictured.  That Crack sounded _heavenly_ with the HD650.. man!


----------



## palmfish

Well it looks like I will be keeping my Crack after all. Lots of lookers but no takers. Oh well, I probably would have had sellers remorse anyways.

At the moment I'm enjoying the soundtrack from the movie "Master and Commander" via Oppo BDP-83 > Asus DAC > Crack > HD800. So good


----------



## kothganesh

Yeah, it was strange to see 5-6 Cracks appear all of a sudden on the FS/FT.


----------



## EraserXIV

It's summer, prime season for upgraditis


----------



## Aeolus Kratos

flysweep said:


> How do I know?  Hmm.. I've just got a feeling.
> 
> 
> 
> ...


 

 Very nice! I'm really enjoying your Tung-sol 12AU7. It seems like you were very surprised that I've got all the cables included in your sale. But guess what, I think it will be even more surprising for you if you see this 
	

	
	
		
		

		
		
	


	




:


----------



## Armaegis

palmfish said:


> Well it looks like I will be keeping my Crack after all. Lots of lookers but no takers. Oh well, I probably would have had sellers remorse anyways.


 
  
 I had seller's remorse, so I built another one. Then I sold it to buy something else. Then I had seller's remorse so I built another one. Then I sold it to buy something else... so far so good... but maybe that's because I'm out of money...


----------



## palmfish

Haha, yeah, I should have known...


----------



## i luvmusic 2

I opened my email today and guess what i've got,A shipping confirmation from BH for my CRACK and SB.......YAY i'am soo excited


----------



## Loquah

Awesome! Exciting times...


----------



## kothganesh

i luvmusic 2 said:


> I opened my email today and guess what i've got,A shipping confirmation from BH for my CRACK and SB.......YAY i'am soo excited


 
 Congratulations. Are you going to build it yourself?


----------



## Vitalstatistix

i luvmusic 2 said:


> I opened my email today and guess what i've got,A shipping confirmation from BH for my CRACK and SB.......YAY i'am soo excited


 
 Grats! When did you order it? I'm still waiting for mine.


----------



## i luvmusic 2

kothganesh said:


> i luvmusic 2 said:
> 
> 
> > I opened my email today and guess what i've got,A shipping confirmation from BH for my CRACK and SB.......YAY i'am soo excited
> ...


 
 Yes i'am.Thank You!


----------



## i luvmusic 2

vitalstatistix said:


> i luvmusic 2 said:
> 
> 
> > I opened my email today and guess what i've got,A shipping confirmation from BH for my CRACK and SB.......YAY i'am soo excited
> ...


 
 I ordered my June 19. Thank You and Good Luck!


----------



## i luvmusic 2

loquah said:


> Awesome! Exciting times...


 
 Yeah i can't wait,Thanks!


----------



## Aeolus Kratos

I
  
 I just love the nice yellow light coming from my lamp, it really makes my tubes look...well, super attractive, sexy and addictive


----------



## jgreen16

^^^ Those cables look like they could hurt someone.


----------



## NightFlight

.
  
 Removed my explanation of a preamp. Doc B. was much more succinct.


----------



## diaBoliQu3

aeolus kratos said:


> I
> 
> I just love the nice yellow light coming from my lamp, it really makes my tubes look...well, super attractive, sexy and addictive


 

 Single Crack is not enough? Must need double crack?


----------



## pdrm360

aeolus kratos said:


> I just love the nice yellow light coming from my lamp, it really makes my tubes look...well, super attractive, sexy and addictive


 
  
 Which color of crack sound better?


----------



## i luvmusic 2

Man this waiting time is really killing me my Crack was just picked up today that means i will not received it until next week.


----------



## benjaminhuypham

@Iluvmusic2: me too =( I ordered it July 2nd, feeling so restless now.


----------



## i luvmusic 2

benjaminhuypham said:


> @Iluvmusic2: me too =( I ordered it July 2nd, feeling so restless now.


 
  The last time i've checked the CRACK shipping status from their web site it show that they shipped orders through july 4th so you should have yours already that was since last week but then i could be wrong.


----------



## i luvmusic 2

Ooops BH site is down for maintenance.I think they shipped order through june 4th not july.


----------



## beez

i put mine together couple weeks ago. sounds so good i honestly cant believe it. i loved putting it together and now have a new hobby. my senn hd580 sound better than i could have imagined. for the first time i enjoy a headphone as much as my grados. and it sounds as good as anything ive ever heard. 

it runs very very hot though. is this normal?


----------



## benjaminhuypham

Alright, seems like they ship on 4th of every month. Last time was 6/4 and now 7/4. I don't know if it's coincident.

Attention Crack buyers: order Crack amplifier before 4th of every month =)) (from my personal experience)


----------



## benjaminhuypham

@iluvmusic2: Oooppp, I didn't read your next post, sorry everyone. My prediction is irrelevant now.


----------



## Armaegis

beez said:


> it runs very very hot though. is this normal?


 
  
 Yes. Most tubes get quite hot. Part of the circuit is called a heater for a reason


----------



## beez

armaegis said:


> Yes. Most tubes get quite hot. Part of the circuit is called a heater for a reason




the whole top plate gets very hot as well. my only tube amp prior to this was a head direct ef1 hybrid. since i put this one together and it was my first soldering job i just wanna make sure this isnt something wrong.


----------



## Armaegis

The big rectangular resistors (right under the vents) get very very hot. The shorter one near the transformer gets quite hot too. The entire plate gets quite warm as a result, and just hot enough to burn (or at least be highly uncomfortable) right at the vents.
  
 p.s. don't touch the tubes either. I tried that once... and seared my fingerprints into it.


----------



## Aeolus Kratos

diaboliqu3 said:


> Single Crack is not enough? Must need double crack?


 
 Hi diaBoliQu3,
  
 I'm using 2 Cracks to see if the capacitor/attenuator upgrades really improve anything from the stock Crack. The 'original' wood base Crack is the upgraded Crack, in which includes the clarity caps, ERSE caps and the Alps Blue Velvet Potentiometer; the brown one is the stock speedballed Crack.
  
 Cheers,
 Kratos.
  


pdrm360 said:


> Which color of crack sound better?


 
 The 'original' color one, certainly, because it was highly modded 
	

	
	
		
		

		
		
	


	



  
 Regards,
 Kratos.


----------



## diaBoliQu3

aeolus kratos said:


> Hi diaBoliQu3,
> 
> I'm using 2 Cracks to see if the capacitor/attenuator upgrades really improve anything from the stock Crack. The 'original' wood base Crack is the upgraded Crack, in which includes the clarity caps, ERSE caps and the Alps Blue Velvet Potentiometer; the brown one is the stock speedballed Crack.
> 
> ...


 

 One Crack is never enough. 
	

	
	
		
		

		
		
	


	




 So, how much did you spend for modded and how much percentage does it bring up to? This is too much. Stock Crack is good, Balls upgrade is better, but there's no best setup for this amp. Urgh!


----------



## JamieMcC

diaboliqu3 said:


> One Crack is never enough.
> 
> 
> 
> ...


 
  
 Less than a half decent aftermarket cable around $100 or half that if your not to worried about using Russian surplus film capacitors or film motor run capacitors instead of audio branded ones.


----------



## adamaley

matttcg said:


> Just wanted to throw this out as an interest check. I'll possibly be producing some custom bases out of exotic types woods. Black walnut, tiger wood, birdseye maple ect. I plan to build about 10 bases and sell them here on the forums. It will be a US only sale and will be a limited run. Please pm me if you have any interest.


 

 Did this ever come to fruition? I will certainly be interested.


----------



## MattTCG

I have a few custom bases. PM me for details vv


----------



## ben_r_

matttcg said:


> I have a few custom bases. PM me for details vv


 

 Post a pic or two!


----------



## MattTCG

This is the burled walnut. Got to take some pics of the others.


----------



## benjaminhuypham

I just checked the Bottlehead page and seems like they shipped all orders through 7/1. I ordered in 7/2 and feel a bit worry now =[[. This waiting is simply killing me.


----------



## JamieMcC

benjaminhuypham said:


> I just checked the Bottlehead page and seems like they shipped all orders through 7/1. I ordered in 7/2 and feel a bit worry now =[[. This waiting is simply killing me.


 
  
 Don't check try to forget about it then its a surprise when it arrives.
	

	
	
		
		

		
		
	


	



  
 Good things come to those who wait..


----------



## adamaley

What is everyone's opinion of the best driver tube to be paired with the TS 5998? Also, please explain why this pairing works best for you, and if possible, include what headphone you are using. I have a TS 5998 incoming and I want to go ahead and purchase a viable complement before it arrives. Thanks in advance guys.


----------



## Aeolus Kratos

adamaley said:


> What is everyone's opinion of the best driver tube to be paired with the TS 5998? Also, please explain why this pairing works best for you, and if possible, include what headphone you are using. I have a TS 5998 incoming and I want to go ahead and purchase a viable complement before it arrives. Thanks in advance guys.


 

 I really had a good time listening to my 5998 + Amperex E80CC gold pins. But if you can, you should get a Bendix 6080WB slotted graphite plate power tube. I got one and my 5998 has been collecting dust on my desk since. I much prefer the Bendix over the 5998.
  
 If you want to stick with the 12AU7s, I would recommend the Mullard CV4003 and Tung-sol 'black/gray' plate 12AU7.
  
 I'm using BeyerDynamic T1 and Sennheiser HD650.


----------



## kothganesh

adamaley said:


> What is everyone's opinion of the best driver tube to be paired with the TS 5998? Also, please explain why this pairing works best for you, and if possible, include what headphone you are using. I have a TS 5998 incoming and I want to go ahead and purchase a viable complement before it arrives. Thanks in advance guys.


 
 I like the RCA clear top 12AU7 with the 5998.


----------



## adamaley

Great recommendations so far. Kothganesh, I have the RCA Cleartops so I will pair that with the 5998 first when it arrives. Akso, which headphones are you using btw? Aeolus Kratos, what would you say are the attributes of the Bendix 6080 that beat the TS 5998?


----------



## JamieMcC

The Bendix 6080wb's are interesting tubes and have a unique sound, for me they where  a step to far from the neutrality delicacy I look for imparting to much flavour for my liking but there is no denying they can rock hard. Most probably I didn't have a good match of input tube for mine as I had been thinning out my 12au7 pile only keeping a couple of favourites after switching over to predominantly running with the e80cc and 12bh7 for the input spot, neither of them performed well when combined with the Bendix.
  
 The 5998 I think has probably a wider range of genre compatibility and when paired with the e80cc or 12bh7 I felt (subjective) there was a increase in refinement heard across the board, I find particularly in vocal presentation it helped with layering of textures to better reveal hidden nuance and delicacy in voices, atmosphere and venue acoustic retrieval on live recordings I find pretty good to.


----------



## i luvmusic 2

benjaminhuypham said:


> I just checked the Bottlehead page and seems like they shipped all orders through 7/1. I ordered in 7/2 and feel a bit worry now =[[. This waiting is simply killing me.


 
 I know the feeling,this will be the 5th week since i ordered mine just Tracked mine and it's on it's way to my mailbox from tomorrow until this friday or i will be hunting my mailman.


----------



## guildenstern

jamiemcc said:


> The 5998 I think has probably a wider range of genre compatibility and when paired with the e80cc or 12bh7 I felt (subjective) there was a increase in refinement heard across the board, I find particularly in vocal presentation it helped with layering of textures to better reveal hidden nuance and delicacy in voices, atmosphere and venue acoustic retrieval on live recordings I find pretty good to.


 
  
 For the Crack with Speedball, are the e80cc and 12bh7 simple drop-in replacements for 12au7, or are circuit mods required? Thanks.


----------



## skeptic

not required. I have been running 12bh7's in mine since 2011 without any issues, although I do occasionally wonder what they would sound like at their intended operating point! may have to give that mod a go one of these days.


----------



## JamieMcC

guildenstern said:


> For the Crack with Speedball, are the e80cc and 12bh7 simple drop-in replacements for 12au7, or are circuit mods required? Thanks.


 

 I used them in with my Crack+SB for about six months with no problems prior to doing the speedball resistor and switch circuit mod detailed on the bottlehead forum which allows for more optimal voltages.
  
 Details of resistor mod in the link below.
  
http://bottlehead.com/smf/index.php/topic,5989.0.html


----------



## i luvmusic 2

So i received my Kit yesterday and i'am a little disappointed about the wood case and the aluminum plate.The wood case is not all the same height there is about 1/16'' defference in height and the plate is slightly curved.How do you flattened/straighten  the plate?shipping it back to US is not an option for me the shipping cost is $36 unless i get a replacement case and plate with free shipping.


----------



## Keithpgdrb

i luvmusic 2 said:


> So i received my Kit yesterday and i'am a little disappointed about the wood case and the aluminum plate.The wood case is not all the same height there is about 1/16'' defference in height and the plate is slightly curved.How do you flattened/straighten  the plate?shipping it back to US is not an option for me the shipping cost is $36 unless i get a replacement case and plate with free shipping.


 
 probably send this to customer service.  not this thread.


----------



## i luvmusic 2

keithpgdrb said:


> i luvmusic 2 said:
> 
> 
> > So i received my Kit yesterday and i'am a little disappointed about the wood case and the aluminum plate.The wood case is not all the same height there is about 1/16'' defference in height and the plate is slightly curved.How do you flattened/straighten  the plate?shipping it back to US is not an option for me the shipping cost is $36 unless i get a replacement case and plate with free shipping.
> ...


 
 yes i will.Thanks!


----------



## atraf

i luvmusic 2 said:


> So i received my Kit yesterday and i'am a little disappointed about the wood case and the aluminum plate.The wood case is not all the same height there is about 1/16'' defference in height and the plate is slightly curved.How do you flattened/straighten  the plate?shipping it back to US is not an option for me the shipping cost is $36 unless i get a replacement case and plate with free shipping.


 
 I thought I was the only one :\
 I have encountered the same problem with my kit, the plate is like a banana I tried straighten it but it just doesn't work, and I only noticed it after I completed building the box which was also not aligned like you said, so a little sanding fix that but plate is still curved I thought maybe the weight of everything when its built might help it a bit but I doubt it, its annoying you can the see the edge of the plate popping from the side 1 mm above the case it looks really bad :\


----------



## i luvmusic 2

atraf said:


> i luvmusic 2 said:
> 
> 
> > So i received my Kit yesterday and i'am a little disappointed about the wood case and the aluminum plate.The wood case is not all the same height there is about 1/16'' defference in height and the plate is slightly curved.How do you flattened/straighten  the plate?shipping it back to US is not an option for me the shipping cost is $36 unless i get a replacement case and plate with free shipping.
> ...


 
  Sure sanding it to flush is what i have to do if i can straighten the plate, luckily i checked those before i start building them so far i can't start working on my kit
	

	
	
		
		

		
		
	


	




.I do have a 12"X12" stainless plate but that SoB is  tough to cut.


----------



## i luvmusic 2

After over a month waited for my kit nothing i can do for now that curved plate is holding me back.


----------



## Loquah

Wow. That's terrible news. I'm really shocked to read that and can only assume it would be an error from the supplier that they couldn't see (i.e. once plates came fro supplier already wrapped in plastic) before shipping. I hope you can get it sorted quickly!


----------



## i luvmusic 2

loquah said:


> Wow. That's terrible news. I'm really shocked to read that and can only assume it would be an error from the supplier that they couldn't see (i.e. once plates came fro supplier already wrapped in plastic) before shipping. I hope you can get it sorted quickly!


 
 I hope soo...........


----------



## Loquah

Hmmm. I wonder if the weight of the transformer would be enough to flatten it back out once installed and sitting in the box?


----------



## i luvmusic 2

loquah said:


> Hmmm. I wonder if the weight of the transformer would be enough to flatten it back out once installed and sitting in the box?


 
 NOPE i thought  about that i tried it did not work.


----------



## i luvmusic 2

If build it upside down the top would look like a pregnant woman laying down.


----------



## atraf

Exacly like mine, same angle, like it was created that way.
 Got mine about 3 week ago just got the time to started working on it a couple of days ago, this is how mine looks..
 Didn't install anything yet, i am trying to find a solution bending with my hands it just doesn't cut it :\


----------



## i luvmusic 2

This top plate is useless to me i don't want to build it like this untill everything is sorted out from BH.


----------



## i luvmusic 2

atraf said:


> Exacly like mine, same angle, like it was created that way.
> Got mine about 3 week ago just got the time to started working on it a couple of days ago, this is how mine looks..
> Didn't install anything yet, i am trying to find a solution bending with my hands it just doesn't cut it :\


 
 EXACTLY that BAD mine too but i did not start building,I just sent a photo to BH i'am waiting for a reply now.


----------



## i luvmusic 2

I did not even bothered to try fixing it i'am leaving it like that for now.


----------



## atraf

i luvmusic 2 said:


> EXACTLY that BAD mine too but i did not start building,I just sent a photo to BH i'am waiting for a reply now.


 
 Same here waiting for a reply.


----------



## Doc B.

The panels are flat when we ship them (and I brush every one myself so I look at every single panel), so there was maybe some rough handling in shipping. Based upon 20 years of making these kits I think you will have good fit once you get the transformer on there and the weight of it presses the panel into the base. It's aluminum and therefore pretty easy to gently bend straight if you feel the need. I hope that doesn't seem like I am trying to blow you off, we do care about the quality of our kits very much. But I would say this is something you can correct to your satisfaction without needing to lose time sending it back to us.


----------



## i luvmusic 2

When i was building this i used a 2X6 lumber and a rubber mallet to flattened the aluminum plate.Put a perfectly flat 1X12 board on the concrete floor put the plate over 1X12 board then the 2X4 on top of the plate and start pounding until it's flat,But this aluminum i used is a bit softer than the crack plate.


----------



## i luvmusic 2

I dry fit the base held by tape each corner then i put the plate on top of the base like how it should fit then put the transformer on top of the plate nothing happened the plate still curved.Actually it looks bad if the transformer is seating on the plate because one side is lift up cause of the bend.By bending the plate by hand it's not that easy and IMO if you are not careful doing that you will end up putting a wrinkle on the plate i did that before.


----------



## Doc B.

I just bent a Crack panel gently over my knee by springing a couple of times lightly and put about as much curvature as you show in the photo. Then I reversed it to flat the same way. I would suggest that lumber and mallets are simply not necessary, and might damage the brushed finish.
  
 We can send you another panel if you feel you can't simply straighten it out to your satisfaction.


----------



## atraf

I will give it another try, I didn't try put intensive force on it since I was afraid on making it worst some how :|


----------



## i luvmusic 2

Mine is fixed i used my POUNDING method and it works.


----------



## i luvmusic 2

so it's true Hammer fix it all.


----------



## i luvmusic 2

doc b. said:


> I just bent a Crack panel gently over my knee by springing a couple of times lightly and put about as much curvature as you show in the photo. Then I reversed it to flat the same way. I would suggest that lumber and mallets are simply not necessary, and might damage the brushed finish.
> 
> We can send you another panel if you feel you can't simply straighten it out to your satisfaction.


 
 No need for me, Thank You very much for your concern!


----------



## i luvmusic 2

Now i can start building oooooh yeeeeah!


----------



## atraf

O.k I guess I just needed the assurance I won't make it worst.
 I used more force and it worked  
 Thanks Doc for the quick response.


----------



## i luvmusic 2

I'am glad that it work out well for you too.


----------



## adamaley

I understand the need the frustration you guys are going through, but I feel, from reading this thread, that Bottlehead has a proven record of God customer service and taking care of issues like this. It is a little unfair to not go to them directly and give them a chance to resolve the issue first.


----------



## atraf

adamaley said:


> I understand the need the frustration you guys are going through, but I feel, from reading this thread, that Bottlehead has a proven record of God customer service and taking care of issues like this. It is a little unfair to not go to them directly and give them a chance to resolve the issue first.


 
 To be honest I wasn't thinking of contacting them at all I just accepted it, didn't want to wait any longer, but after seeing I am not the only one I thought that there is might be a bigger issue here.
 since bottlehead forums are down ( at list for me) I don't think there is problem talking about it since its known that doc is here as well.
 Btw no one was accusing no one of anything.. just had an issue and I came for the community for help.. that is it, and it worked.
  
 Bottlehead service so far was amazing with every issue I encountered.


----------



## MattTCG

adamaley said:


> I understand the need the frustration you guys are going through, but I feel, from reading this thread, that Bottlehead has a proven record of *God customer* service and taking care of issues like this. It is a little unfair to not go to them directly and give them a chance to resolve the issue first.


 
  
 Customer service just can't get much better than that. 
	

	
	
		
		

		
		
	


	




 There is nothing wrong with posting problems and issues here. It was not done maliciously and it's how lot's of problems get worked out around these parts.


----------



## Doc B.

Yeah I suspected there might be some frustration if I didn't address this here as we have been enduring some DDoS attacks today that have made our site up and down.


----------



## diaBoliQu3

adamaley said:


> I understand the need the frustration you guys are going through, but I feel, from reading this thread, that Bottlehead has a proven record of God customer service and taking care of issues like this. It is a little unfair to not go to them directly and give them a chance to resolve the issue first.


 
 You're a God but you pay them to serve you.
	

	
	
		
		

		
		
	


	



  
 Anyway, Bottlehead gave me a good service too. It's just that I have bad luck. Lol. Since day one, till my amp completed there's always something wrong with it.


----------



## adamaley

Lol. That's what I get for sending posts with my phone. I meant to say good customer service. Anyway, I've always felt it best to give the manufacturer a chance to solve your problem, before posting on an external website. However, I do see how it could be helpful to post it here for tips on solving the problem at hand. I meant no offence to you guys. All the best in solving your issues, and happy listening.


----------



## trentrosa

It's unfortunate the bottlehead site is down, i was interested in shipping status.
  
 Good luck sorting it out Doc!


----------



## Doc B.

My awesome IT guy is doing some refinement of our setup this evening and I imagine he will have the site back up fairly soon. You can also call the office from about 10-5 PT tomorrow and Josh can give you an update. 206-451-4275


----------



## trentrosa

Ddos is getting to be a more and more common occurrence it seems...
  
 Thanks for the update Doc, I'm just eager to get soldering!


----------



## benjaminhuypham

Got my Crack today, done almost half way of building it. I'm pretty confident to say the Crack is not hard to build if you have all tools needed and spend enough time for reading construction and picking correct components. Soldering can be problematic for someone, but if the wires are not loose, they should be fine. Thanks Doc B for the amp, it's such a joy of diying the Crack. More importantly, it's worth a month waiting.


----------



## kothganesh

To all you guys that build the BHC (I chickened out and gave it to my expert technician), the sound at the other end is more than worth the effort. Makes you wanna buy the HD 800 if you don't have one already.


----------



## benjaminhuypham

I wished I could afford the HD800. I've never heard the HD800 with Crack, but the HD650 paring with Crack is just mesmerizing. 

Enough Said 

Ben


----------



## diaBoliQu3

adamaley said:


> Lol. That's what I get for sending posts with my phone. I meant to say good customer service. Anyway, I've always felt it best to give the manufacturer a chance to solve your problem, before posting on an external website. However, I do see how it could be helpful to post it here for tips on solving the problem at hand. I meant no offence to you guys. All the best in solving your issues, and happy listening.


 
 The auto correct more worst when there's some beer or liquor kick your head and judgement. Hahaha...


----------



## Aeolus Kratos

kothganesh said:


> Makes you wanna buy the HD 800 if you don't have one already.


 
 .... or the T1


----------



## kothganesh

aeolus kratos said:


> .... or the T1



AK, how do you rate one versus the other?


----------



## Aeolus Kratos

kothganesh said:


> AK, how do you rate one versus the other?


 
  This is what I said in the T1 impressions and discussion thread about the comparison between the T1 and the HD800.
  
 Quote:


aeolus kratos said:


> Hmm, interesting, I've been a fan of HD800s for over two years, and I have to admit that I hadn't heard the T1 when I was having the HD800s. I had a pair of HD800s, one has the early and one has the late serial number ( 2xxxx ) . Just recently, I bought a T1 from buydig too ( with $740, a bit more than the discount price now ). When I heard the T1 with my Bottlehead Crack for the 1st time, I nearly couldn't believe my ears, the T1 was better in many genres than the HD800s ( except for classical ), especially the midrange. I sold one of my HD800s right away.
> 
> So I guess maybe the HD800s are more superior in terms of 'accuracy' and 'technical factor', but I've never had the same feeling when I listened to vocals with the HD800s as I had with the T1s. I don't care if this headphone has a more balanced FR, it has a bigger soundstage or it provides a more 'accurate' sound, the only thing I care is how I feel about the music. We're all here, sharing experiences to each other on our passion, the love for 'music', NOT 'sound'. As long as I enjoy and have a good time listening to music, everything else doesn't matter to me. In that region, the T1s, IMHO, actually do a better job than the HD800s.
> 
> I'm not saying the T1s sound 'better' than the HD800s, they just match my 'taste' perfectly and give me the enjoyment I've never had with the HD800s.


  
 I'm currently having both of them. IMO, each headphone has its own presentation. You can not say which headphone is BETTER. I personally use my HD800 for listening to classical ( which is not my main genre ), being the 'reference' headphone and testing, but I use the T1 whenever I want to just sit back, relax and ENJOY my music. The HD800 can not give me goosebumps or the emotion when I listen to my favorite music - vocals and country, mostly, like the T1 does. So I think it really depends on many things.
  
 A bit OT: I really think that each headphone which is called 'flagship' has their own presentation, none of them is bad. Each flagship was made/produced for specific needs, references and people, the fact that you don't like a flagship doesn't mean other people are the same as you, and vice versa.
  
 Both the T1 and the HD800 are flagships of two of the biggest headphone brands on the market - BeyderDynamic and Sennheiser, just saying.


----------



## kothganesh

aeolus kratos said:


> ..............


 
 Beyer is the only company whose sound I have not heard (among the bigger companies). I have two "TOTL" HPs coming my way and I'm already intrigued with the T1 !!!!


----------



## benjaminhuypham

Would anyone help me find cables connecting the Crack and my laptops? Any suggestions with a link would be great. 

Thanks,

Ben


----------



## MattTCG

benjaminhuypham said:


> Would anyone help me find cables connecting the Crack and my laptops? Any suggestions with a link would be great.
> 
> Thanks,
> 
> Ben


 
  
 You mean with no dac?


----------



## kothganesh

matttcg said:


> You mean with no dac? :blink:



Exactly. I thought he was asking for DAC recommendations as well.


----------



## ramaka

Any recomendations for DAC to pair with Crack-budget 400 USD max? I use Senn HD650 and Beyer T1 and maybe in the future snag either Senn HD800 or HE 560. Thank you!


----------



## liamstrain

With no DAC, you will probably need to use a 3.5mm stereo mini to RCA adapter cable. This goes from your computer's headphone jack (or if you have a line out from a sound card - use that instead).  

 Like this:


  
  
 http://www.monoprice.com/Product?c_id=102&cp_id=10218&cs_id=1021815&p_id=5597&seq=1&format=2


----------



## skeptic

If you want some high quality, but affordable, pro quality cables, blue jeans cable is a good source: http://www.bluejeanscable.com/store/audio/index.htm
  
 Alternatively, you can easily make your own.  Pickup some mogami star quad and some switchcraft plugs.  Very easy to work with.  Finish with appropriately sized heat shrink.


----------



## benjaminhuypham

Thank you guys all. If I use Aune T1 as a DAC, what else I have to buy?


----------



## liamstrain

It looks to me like the Aune T1 has RCA outs, so just RCA to RCA cables.


----------



## JamieMcC

aeolus kratos said:


>


 

 + 1 with the T1 Crack combo.
  
 Have you tried adding a pair of Russian Teflon bypass's yet they really help in refining the top end along with increasing resolution . They only cost about the same as a cup of coffee!


----------



## Aeolus Kratos

jamiemcc said:


> + 1 with the T1 Crack combo.
> 
> Have you tried adding a pair of Russian Teflon bypass's yet they really help in refining the top end along with increasing resolution . They only cost about the same as a cup of coffee!


 

 No, I haven't. Can you give me some more details or the link to the Russian caps you're referring to?
  
 Thanks!
 Kratos.


----------



## JamieMcC

aeolus kratos said:


> No, I haven't. Can you give me some more details or the link to the Russian caps you're referring to?
> 
> Thanks!
> Kratos.


 

 Hi these are the ones I used K72-P6 they come in several values a couple of ebay links as examples just makes sure the voltage rating is high enough for the application.
  
http://www.ebay.co.uk/itm/0-056uF-500V-5-AUDIO-teflon-capacitors-K72P-6-Lot-of-2pcs-/261249457353?pt=LH_DefaultDomain_0&hash=item3cd3ae5cc9
  
http://www.ebay.co.uk/itm/0-1uF-200V-teflon-capacitors-K72-P6-K72P6-Lot-of-4-/300492310885?pt=Vintage_Electronics_R2&hash=item45f6bcc965


----------



## i luvmusic 2

How do you guys cleanup the transformer's(varnish residue)and can i spray paint it?I want to spray paint the Transformer bell do i need to use a Primer before i spray paint it?


----------



## FunyunBreath

When I did mine while back I roughed the surface up with 200 grit sandpaper, then 2 coats of primer, and 2 coats of spray paint. That was prolly a year ago and it's still holding up just fine


----------



## benjaminhuypham

I just finished building Crack and unfortunately, they don't power on


----------



## FunyunBreath

I'd go through and recheck every solder joint and make sure you didn't miss anything. I'm no electrical expert but from my experience 9/10 times its usually just a broken connection somewhere.


----------



## FunyunBreath

On another note, does anyone know what the stock 5963 tube that was shipped with the latest kits is? It sounds awesome! Unfortunately the label on mine is worn off and I have no idea what the brand is.


----------



## benjaminhuypham

These are pictures of the completed Crack 
  

  

  

  

  
  
 These are components left: 
  

  
  
 I did carefully follow construction, it seems really hard to check back now. I'm totally screwed


----------



## benjaminhuypham

funyunbreath said:


> On another note, does anyone know what the stock 5963 tube that was shipped with the latest kits is? It sounds awesome! Unfortunately the label on mine is worn off and I have no idea what the brand is.


 
  
 It's RCA 6080WA, I guess. my driver tube does not fit the tube socket though


----------



## FunyunBreath

Well you kit isn't powering on cause that glass vial is the 25V fuse that needs to be installed where your power cord plugs into.
  
 However, being that you have that extra resistor that wasn't installed I wouldn't power that thing on until you figure out where it was supposed to be soldered.


----------



## jboehle

Looks like that resistor probably goes between terminal 12 & 13 IIRC, please verify with the assembly guide and don't take my word for it.
  
 Why did you mount the tube socket in the middle on top of the plate instead of underneath?
  
 And you didn't follow the assembly guide carefully - you didn't braid the input wires that go between the input jacks & pot.  You didn't twist the wires that go between the terminals on the transformer.


----------



## jboehle

benjaminhuypham said:


> It's RCA 6080WA, I guess. my driver tube does not fit the tube socket though


 
  
 The 5963 is a variant of the smaller 12AU7 tube that goes in the front.  The 6080 is the larger tube that goes in the middle.


----------



## fullheadofnothing

Your transformer is incorrectly mounted.
  
 Your tube sockets are incorrectly mounted.
  
 You have left out the resistor that drains the power supply when the power is off.
  
 You have left the feet off; as such your amplifier will be likely to overheat and damage components.
  
  
 Your build overall is unsafe and virtually guaranteed to be noisy.


----------



## benjaminhuypham

Thank you all, I'm fixing them now.


----------



## i luvmusic 2

funyunbreath said:


> When I did mine while back I roughed the surface up with 200 grit sandpaper, then 2 coats of primer, and 2 coats of spray paint. That was prolly a year ago and it's still holding up just fine


 
 How do i cleanup the transformer's varnish/shellac residue?I thought about sanding it or using some kind of solvent.


----------



## FunyunBreath

Oh I just painted the bell on top. I'm not sure how to paint the sides without getting paint on the internals.


----------



## benjaminhuypham

hi guys, i don't know why my Crack still isn't powering on? I tried to fix the Power Transformer already and nothing changed. It was my first DIY and I know mistakes may occur, but I feel very depressed now.


----------



## Loquah

benjaminhuypham said:


> hi guys, i don't know why my Crack still isn't powering on? I tried to fix the Power Transformer already and nothing changed. It was my first DIY and I know mistakes may occur, but I feel very depressed now.


 
  
 Based on your previous posts, I'd say you really need to step through the manual and check that *every single* component is installed exactly as the manual says and shows. This isn't about being difficult, but if everything isn't exactly as per the manual, then there's no real way to problem solve.
  
 Also, did you do resistance tests and voltage tests?


----------



## adamaley

benjaminhuypham said:


> hi guys, i don't know why my Crack still isn't powering on? I tried to fix the Power Transformer already and nothing changed. It was my first DIY and I know mistakes may occur, but I feel very depressed now.




As an Arsenal fan, I should take pleasure in your suffering, but I won't. Posting on the bottlehead forums will give you more qualified assistance than on here. It's more active for troubleshooting.


----------



## trentrosa

benjaminhuypham said:


> hi guys, i don't know why my Crack still isn't powering on? I tried to fix the Power Transformer already and nothing changed. It was my first DIY and I know mistakes may occur, but I feel very depressed now.


 
 In reference to your previous post, to get your amplifier working ENSURE you have;
  
 - de-soldered connections to tube sockets and re-installed in accordance to the manual,
 - installed bleeding resistor across terminals 12/13 with capacitor,
 - inspected then installed fuse correctly into socket,
 - performed resistance/voltage measurements (if they are incorrect please most your results so the source of the problem can be identified, only after you have corrected outstanding issues)
  
 If the led's across the driver tube and elements within the tubes do not glow, please perform, record, and post your test measurements.
  
 While your iron is hot it is advisable to correctly braid the input wiring to the volume pot and twist the wires where the manual identifies. This is to ensure the quiet performance of the amp and should not be overlooked.
  
 Good luck,


----------



## trentrosa

Also, please double check the polarity of the power supply capacitor sitting parallel with the chassis plate.


----------



## benjaminhuypham

loquah said:


> Based on your previous posts, I'd say you really need to step through the manual and check that *every single* component is installed exactly as the manual says and shows. This isn't about being difficult, but if everything isn't exactly as per the manual, then there's no real way to problem solve.
> 
> Also, did you do resistance tests and voltage tests?


 
  
 Thanks Loquah, I'm not be able to check cos I don't have tools.
  
  
  
  


trentrosa said:


> In reference to your previous post, to get your amplifier working ENSURE you have;
> 
> - de-soldered connections to tube sockets and re-installed in accordance to the manual,
> - installed bleeding resistor across terminals 12/13 with capacitor,
> ...


 
  
 Thanks Trentrosa, I did install bleeding resistor across terminals 12/13 with capacitor after I posted pics.
  
  
 Man, fixing *everything *is really a nightmare.


----------



## trentrosa

If you're going to keep up diy a volt meter is an absolute essential, I highly recommend even an inexpensive one. Touch base again when you've matched your amp to the expected outcome of the manual.


----------



## skeptic

Yeah. Taking it slow and double or triple checking each step is A LOT easier than debugging numerous mistakes. 

If your tubes are not coming up at all, you can assume there is a problem with the wiring at (1) your power switch (did you ever install your fuse?), (2) your transformer and/or (3) the twisted pairs that go from the transformer to the heater pins at each socket. If you don't have the correct voltage on those heater pins, the tubes won't light up at all. But you've got other issues as well. In addition to those mentioned above, where are the LEDs on your A socket? No current will go through the tube without them... 

But I definitely agree that you need to start on page one of the manual and check off each and every sentence with a pencil after you confirm the step was completed or corrected. If possible, have a friend or family member do it with you... You can't just skip stuff like tightly braiding the input wiring or your amp is going to sound ****ty even if it is in working condition. 

Frankly, you shouldn't have ever gotten to the point of turning it on, because you shouldn't have passed the resistance checks. Do you have a volt meter? Please follow the manual carefully. This is a beginner appropriate project but you are still dealing with high voltage that can stop your heart. If you can't follow the manual word for word, then you really should stop and get help from a technician or friend who can help you complete this safely. I mean no offense. I am just honestly concerned by how far off this build is from the instructions.


----------



## JamieMcC

benjaminhuypham said:


> I just finished building Crack and unfortunately, they don't power on


 
 You will need to also install the left over shoulder washer you have on the underside of the transformer see page 14 of your manual
  
 The LED installation instructions are on page 23 they are very small and can easily be missed while unpacking the components.
  
 As posted above start on page one with a pencil and check and tick off each step any step that has not been completed make a note of so its easy to go back to and correct.
  
 Use the pictures for reference that is how your build is supposed to look try and install the components as close as possible to the way they are installed in the pictures 
  
 You should have enough left over wire to braid up some new connecting wires. It is simple easy to do check out the short how to video.
  
https://www.youtube.com/watch?v=qxJY4lna5q0


----------



## JamieMcC

BH site is still down


----------



## atraf

just finished building the crack, i am doing the resistance test and I have a question about terminal 13 its said its suppose to climb slowly to 270k but mine when i put the ohmmeter on 2m start at 1.300 and then go down really slowly to 270 so its not climbing is it ok ? :O 
  
 also b3 and b4 are 2.93 and 2.94 instead of 2.9
 and Right center pin of RCA is 106.4 instead of 90-100 
  
 are these values ok? 
  
 and one last thing I was left during the build with large round lock washer (came 3) I have searched and searched but it doesn't say in the manual anything about what to do with the 3rd one :|


----------



## Doc B.

jamiemcc said:


> BH site is still down




We are making some changes that have required a fair amount of testing before we go live. Things are progressing and we will be up ASAP. Trust me, we want the site up even more than you guys!


----------



## fullheadofnothing

@atraf : The third lockwasher is used on page 14. The starred terminals will vary from meter to meter. As long as you are not getting 0Ω and your capacitors are installed as shown in the manual, you should be fine. As for your resistance checks, they are all within 10%, and therefore fine.


----------



## atraf

fullheadofnothing said:


> @atraf : The third lockwasher is used on page 14. The starred terminals will vary from meter to meter. As long as you are not getting 0Ω and your capacitors are installed as shown in the manual, you should be fine. As for your resistance checks, they are all within 10%, and therefore fine.


 
 Thank you for you reply so where is the first 2? :O in the ground screw? it already came with one washer .. I am clueless.. In page 14 its said I should put one in the transformator screw and I did.. 
  
 Ok time for voltage testing :O
  
  
 Edit: 
 Ok i just noticed its a small lock washer not large, my bad.. I will go over my steps.


----------



## Tarquinflimbim

Doc,
  
 Is the site still down?  I'm getting "no data received".
  
 TFB


----------



## MattTCG

Still down for me.


----------



## atraf

Just finished, my first DIY project and basically soldering in general, enjoyed every moment, couldn't stop working on it.
 SpeedBall is waiting to be added in a few week, also hoping to replace the volume knob as soon as possible


----------



## Doc B.

We are making some changes to the website structure that are rather technical. Our IT man is working on it very intensely and we will have it up ASAP. Probably have the forum live some time in the next 18-24 hours.


----------



## JamieMcC

atraf said:


> Just finished, my first DIY project and basically soldering in general, enjoyed every moment, couldn't stop working on it.
> SpeedBall is waiting to be added in a few week, also hoping to replace the volume knob as soon as possible


 
  





 Congratulations I wonder how long you will last before fitting your Speedball? I managed a week before the temptation to fit mine  got the better of me.


----------



## Vitalstatistix

atraf: that's a beautiful looking amp and congrats on your first build! Which stain did you use for the base?


----------



## liamstrain

Glad you got it fired up, atraf. Enjoy!


----------



## atraf

Double Posting


----------



## atraf

jamiemcc said:


> Congratulations I wonder how long you will last before fitting your Speedball? I managed a week before the temptation to fit mine  got the better of me.


 
 I am not going to be home in the next week, so I got at list that 
  



vitalstatistix said:


> atraf: that's a beautiful looking amp and congrats on your first build! Which stain did you use for the base?


 
HOLZLASUR 2000 dark brown, I was planning on making it shiny by putting varnish or wax on it but after one layer I really loved the color so I left it this way.​


----------



## Loquah

atraf said:


> HOLZLASUR 2000 darkbrown, I was planning on making it shiny by putting varnish or wax on it but after one layer I really loved the color so I left it this way.​


 
  
 A plain bees wax based polish can help to keep the colour exactly the same while giving it a beautiful smooth finish. I tried various varnish options and kept being unhappy with the results so I sanded back my Mainline and S.E.X. boxes and polished then waxed both with a simple bees wax polish. The results are stunning and impossible to stuff up!


----------



## i luvmusic 2

Since the BH site was down for few days i decided to sand and prime/spray painted the sides of the crack transformer i hope this is not a bad thing.


----------



## i luvmusic 2

atraf said:


> Just finished, my first DIY project and basically soldering in general, enjoyed every moment, couldn't stop working on it.
> SpeedBall is waiting to be added in a few week, also hoping to replace the volume knob as soon as possible


 
 I think the most simple looking finished for the Crack base is the rounded edges,but then again that just me...
	

	
	
		
		

		
		
	


	




 BTW that is what i'am going to do with mine too.


----------



## Bhonka

Does the speedball addon effect electronic music much?
  
 I listen to a lot of house/techno.


----------



## MattTCG

The speedball will give you more bass extension.


----------



## liamstrain

matttcg said:


> The speedball will give you more bass extension.




Arguable, and certainly not with all headphones.


----------



## MattTCG

^^ It's tough to argue with the truth.


----------



## skeptic

bhonka said:


> Does the speedball addon effect electronic music much?
> 
> I listen to a lot of house/techno.




Speedball will give you noticeably tighter, faster bass and a blacker background - definitely a worthwhile upgrade for the sort of music you favor imo. The improvements in the low end might even translate into perceived better bass extension


----------



## Kyno

I'm currently seeking an amp for my HD-650, and why not other headphones further down the road. Something polyvalent would be nice.
  
 I'm torned between Crack + Speedball and ALO Pan Am, would you guys have an opinion?

 Thanks!


----------



## trentrosa

kyno said:


> I'm currently seeking an amp for my HD-650, and why not other headphones further down the road. Something polyvalent would be nice.
> 
> I'm torned between Crack + Speedball and ALO Pan Am, would you guys have an opinion?
> 
> ...




If you want to upgrade headphones down the road and the itch arises to upgrade the amp too, Crack is an excellent platform for diy mods/upgrades.


----------



## liamstrain

The Pan Am is more flexible than the Crack in regards to other headphones (lower impedance, and higher current - means it does better with things like 32 Ohm Grados, or power hungry orthodynamics). 
  
 For just the Sennheiser 6XX cans though, I have not found an amp under $1K that sounds as good as the Crack does with those headphones.


----------



## i luvmusic 2

Finally after 12 hours i finished my CRACK........time for bed.


----------



## Loquah

i luvmusic 2 said:


> Finally after 12 hours i finished my CRACK........time for bed.


 
  
 Congrats!! Did you listen before bed or leaving testing and listening till morning?


----------



## Kyno

liamstrain said:


> The Pan Am is more flexible than the Crack in regards to other headphones (lower impedance, and higher current - means it does better with things like 32 Ohm Grados, or power hungry orthodynamics).
> 
> For just the Sennheiser 6XX cans though, I have not found an amp under $1K that sounds as good as the Crack does with those headphones.


 
 Thanks! You just summed up my dilemna, means I should be on the right track 
	

	
	
		
		

		
		
	


	



  
 Mind you I'm coming from an Asus Essence ST so the Crack should be more decent to judge high-end HPs, it's also missing the DAC so it might be a better idea if I want to test out a separate DAC later.
  
 Next step, wait for a decent EU sale, because it woud get really costly from the US (around $600 just for the Crack + SB 
	

	
	
		
		

		
		
	


	




)


----------



## liamstrain

kyno said:


> so the Crack should be more decent to judge high-end HPs,


 
  
 As long as those HP's are higher impedance. (e.g. 150-600 ohm). To my ears, it starts to get a bit flabby sounding with lower impedance headphones.


----------



## i luvmusic 2

loquah said:


> i luvmusic 2 said:
> 
> 
> > Finally after 12 hours i finished my CRACK........time for bed.
> ...


 
 Yes i listened a bit and so far i loved it very smooth and quiet.Thanks!


----------



## i luvmusic 2

Here is mine  i still need to work on the base and SB.


----------



## trentrosa

Are those coupling caps stock or did you swap them?


----------



## i luvmusic 2

trentrosa said:


> Are those coupling caps stock or did you swap them?


 
 Stock.


----------



## Rapid7

Went to order the crack yesterday, tried to pay via PayPal but got the error "There is a problem with the merchants account". I then sent an email to queen via the contacts link, check my account today and my order has been cancelled... no email to why it was cancelled nothing at all.


----------



## MattTCG

They have had website problems of late. Maybe just try the order again.


----------



## skeptic

Rapid - sorry you had trouble placing your order, but it sounds like it was cancelled by PayPal due to some sort of a glitch....  As you can tell from Doc et al.'s constant involvement in multiple threads here, as well as on their own forums, bottlehead does indeed have excellent customer service.  Maybe try calling them now, during business hours?


----------



## Rapid7

Only problem is I am from the UK so it would cost a small fortune to ring the US.
  
 Thanks.


----------



## JamieMcC

rapid7 said:


> Went to order the crack yesterday, tried to pay via PayPal but got the error "There is a problem with the merchants account". I then sent an email to queen via the contacts link, check my account today and my order has been cancelled... no email to why it was cancelled nothing at all, so much for the great customer service.


 
  
 Bottlehead have been updating their website its been offline intermittently over the last few days + I think it was mentioned Doc and Queen are also away from the office for a few days so suspect there is a little catching up to do and still some fine tuning of the merchant system going on.
  
 You can always ask them to reconfirm the order and I suspect they will send you a paypal invoice if the merchant system is still offline.


----------



## Doc B.

rapid7 said:


> Went to order the crack yesterday, tried to pay via PayPal but got the error "There is a problem with the merchants account". I then sent an email to queen via the contacts link, check my account today and my order has been cancelled... no email to why it was cancelled nothing at all.


 
 Yes, our IT dept. has been doing a lot of update work on the website this weekend and Eileen and I were out of town for several days. Eileen tells me she has been in communication with you this morning about the pending status of your order and it is in the queue. That kind of thing is not something we initiate, i.e. we don't arbitrarily cancel orders, as that would indeed be kind of bad customer service. It was probably just some technical glitch. 
  
 We are closed on weekends and thus our response to weekend emails usually happens on Monday.


----------



## Rapid7

doc b. said:


> Yes, our IT dept. has been doing a lot of update work on the website this weekend and Eileen and I were out of town for several days. Eileen tells me she has been in communication with you this morning about the pending status of your order and it is in the queue. That kind of thing is not something we initiate, i.e. we don't arbitrarily cancel orders, as that would indeed be kind of bad customer service. It was probably just some technical glitch.
> 
> We are closed on weekends and thus our response to weekend emails usually happens on Monday.




Many thanks, you may need to send me an invoice as it wouldn't even let me get as far as logging into my PayPal account.

Thanks again, Paul.


----------



## Jason8777

Can someone please tell me if this is the right octal tube socket?  It doesn't look like the one in the manual
  
 .  My first DIY project and I just want to be sure.  Thanks in advance.


----------



## mcandmar

Looks fine.  Sometimes the parts will change over the years or be from different manufacturers, but its still an 8pin octal socket which is all that matters.


----------



## johnnypaddock

I apologize if this has already been covered, but are there any closed back headphones that people would recommend with the Crack/Speedball?  I normally listen with my HD-600's, and love the amp, but I'm thinking of getting a closed style so I can crank it up at night sometimes and not disturb my wife.
  
 If there aren't any good options, the on-board headphone amp on my Benchmark DAC2 would work for something low impedance, I figure. I just thought I would throw it out there.


----------



## trentrosa

johnnypaddock said:


> I apologize if this has already been covered, but are there any closed back headphones that people would recommend with the Crack/Speedball?  I normally listen with my HD-600's, and love the amp, but I'm thinking of getting a closed style so I can crank it up at night sometimes and not disturb my wife.
> 
> If there aren't any good options, the on-board headphone amp on my Benchmark DAC2 would work for something low impedance, I figure. I just thought I would throw it out there.


 
 The Crack is optimal with headphones of higher impedance. In regards to specifics, it depends on your listening tastes. Maybe check out the Crackheadphone Kit by Bottlehead.


----------



## Loquah

Good call!


----------



## Armaegis

You could also consider a Beyer DT770 with either 250 or 600 ohm drivers.


----------



## i luvmusic 2

I gave my old setup to my wife so she won't hear me playing loud now she plays loud too so her and i are even.


----------



## i luvmusic 2

I made a 6SN7 to 12AU7 adapter and tried it on the CRACK so far so good.


----------



## i luvmusic 2

I'am wondering if i can use a 6SN7 for input and output tubes for the CRACK?


----------



## Loquah

i luvmusic 2 said:


> I'am wondering if i can use a 6SN7 for input and output tubes for the CRACK?


 
  
 There may be people that can answer that question here, but definitely there will be on the Bottlehead Forum


----------



## i luvmusic 2

I think their site is down.Thanks!


----------



## FunyunBreath

Yup you definitely can. I actually just bought an adapter off of Ebay a while back and the 6SN7's sound really really nice.
  
 There's a whole post on the Bottlehead forums on how to actually rewire your input socket with an 8 pin socket for people who want to exclusively use 6SN7's.


----------



## diaBoliQu3

I always ask and wondering, how does Crack sound with Modi or Odac. I buy both to answer my own question. I think it's my end game already. But Modi mainly connected for my Crack due to it's better appearance.


----------



## Doc B.

i luvmusic 2 said:


> I think their site is down.Thanks!




We are making some changes to the site that are pretty involved. There will be some disruption here and there. The site itself is up, but the forum is in maintenance at the moment.


----------



## skeptic

i luvmusic 2 said:


> I'am wondering if i can use a 6SN7 for input and output tubes for the CRACK?




No. Input/a socket only. 6as7(g) 6080 5998 7236 7802 are the options for the power tube.


----------



## FunyunBreath

Yeah sorry didn't see that you were also asking about using a 6SN7 in the power tube socket, definitely don't stick a 6SN7 in there.


----------



## Loquah

diaboliqu3 said:


> I always ask and wondering, how does Crack sound with Modi or Odac. I buy both to answer my own question. I think it's my end game already. But Modi mainly connected for my Crack due to it's better appearance.


 
  
 Out of interest, how would you compare the sound of the Modi vs the Odac?


----------



## MattTCG

The odac was the better sounding of the two for me. There was a natural uncolored presentation coming from the odac but the modi was a little thin for me...ymmv


----------



## i luvmusic 2

6SN7 does work for both input/output tubes i used both of them at once(Input 6SN7 output 6SN7)but i need to turn the volume a bit higher than my usual setting which is around quarter turn but with 6SN7 on both sockets volume is set in between quarter and half mark.It does work but there is nothing to wow about and the amp runs cooler.


----------



## i luvmusic 2

Hi,
    I replaced the pot with the attenuator and i have a concern about my resistance reading for T13 instead of reading up like how it was with the stock pot.Now it reads backwards then reads back up again from 22 meg counting down then when it reach 270 ohms mark it start to read up again.Is this normal if you used a attenuator?Thanks!


----------



## mcandmar

I don't think the pot will have any effect on that reading.  What your trying to measure is the 270k bleeder resistor to discharge the power supply but some meters have trouble with this as the meter itself starts to charge the capacitors while testing.
  
 Check the center pin of the two RCA inputs read ~100k ohms, and the grounds read as close to 0 ohms as your meter can read and you should be good to go.
  
 Also if you are using an attenuator like the Valab make sure the grounds on each side of the attenuator are joined together.


----------



## i luvmusic 2

mcandmar said:


> I don't think the pot will have any effect on that reading.  What your trying to measure is the 270k bleeder resistor to discharge the power supply but some meters have trouble with this as the meter itself starts to charge the capacitors while testing.
> 
> Check the center pin of the two RCA inputs read ~100k ohms, and the grounds read as close to 0 ohms as your meter can read and you should be good to go.
> 
> Also if you are using an attenuator like the Valab make sure the grounds on each side of the attenuator are joined together.


 
  I just measured those RCA jacks they are 101K for both centre pin and 0 on the ground i double checked my resistance and voltage reading and there was  no changes from the last time i did checked after the build only thing is that T13 it did not read like that the first time i measured or i could be wrong and yes i solder both ground for the attenuator I think i got rip-off according to the ebay vendor this attenuator is Dual stereo(see picture).Now it's installed it sounds like i lost a little bit of BASS and sound compressed.Is this what happened if you install MONO isntead of STERO?THANK YOU!


----------



## i luvmusic 2

I don't usually believed in Burn-in except for tubes but for this Attenuator the sound improved over one hour period i was playing it without listening,Then i picked up the HP and give it a listen the compressed sound disappeared compared when i just installed it and listened to it i hate the PoS but now i changed my mind it's actually not that bad no more slight channel  imbalance i used to hear and the background is even quieter.Whatever this thing is STEREO or MONO it's not that bad.


----------



## diaBoliQu3

loquah said:


> Out of interest, how would you compare the sound of the Modi vs the Odac?


 
 Bottlehead Crack DAC pairing comparison:
  
 E-DAC:
 - Noticeable airy in vocal oriented song. Natural timbre and brighter than Modi but not thin. Sometimes can be too bright when involving sharp sound instrument (eg; cymbals) and due to the recording it self. Definitely clean and detail than Modi. Wider soundstage with awesome instrument separation. Relaxed but not too laid back. Fast and punchy bass, but not as low like Modi.
  
 Modi:
 - A little warmer than EDAC but not in warm sounding category. Controlled high and able to tame the bright E-DAC issue. A bit "blanketed" when A/B with EDAC. Less detail and smaller soundstage. Good instrument separation and highlighting the singer. More forward and energetic than E-DAC. Punchier and lower bass extension. A bit of coloration at mids.
  
 Verdict:
 - I will rate E-DAC is 9/10 and Modi is 7/10 in audio performances, based on my sound preferences. I dare to say they are noticeable different to my ear. E-DAC is clean, detail, relax and airy. Modi got a tamed high, colored mids, forward sounding and extra bass. Neither of this two is warm, thin, or dark. Design and value wise, definitely falls to Modi. And I use Modi as my main DAC because it looks better on my table but I do miss the detail and clean sound of E-DAC.
  
 Epiphany Acoustics E-DAC (ODAC)/ Schiit Modi
 Bottlehead Crack (Speedball)
 Sennheiser HD600


----------



## Aeolus Kratos

Hi everyone,
  
 I've encountered the first problem with my Crack today after 2 months working perfectly today. After I stopped listening this morning, I noticed the wood base of my Crack had a crack in the 'edge' ( there's a small 'gap' in the corner of the wood base. So I took out the tubes, the plates and use some super-glue to fix the base. After that, I replaced the plate and the tubes, I turned on the Crack again. Then I plugged my T1 into the Crack and...no sound in the left channel, there was only sound coming from the right one. I turned it off, then turned on again, I immediately plugged my T1 back in and the sound was coming from both channels, but as soon as the tubes got a bit warm up, there was a 'buzzing' and no sound from left channel again. I tried another driver tube ( 12AU7 ) only because I don't have any other power tube but my Bendix 6080WB, as well as turning on and off several times but none of them worked.
  
 Next, I turned my Crack off and let the tubes cool down. I removed all the tubes, the power cord and the interconnect cable, then I placed the plate side-down to the base and tried gently touching, moving the capacitors, the joints and almost all other things in the circuit which I literally didn't know what I was doing, I was kind of doing some nonsense things there. Finally I placed all things back to its places and gave it one final try before taking the Crack to the Audio repair service.
  
 And surprisingly, the problem has been gone since then!
  
 I really had no idea what was wrong with my Crack, this is the first time I've had this problem with my newly-built Crack. Everything was firmed and secured as it should be.
  
 Does anyone have any idea about this? It would be greatly appreciated! I was a bit worried.
  
 Thanks!
 Kratos.


----------



## atsq17

I once couldn't get rid of this annoying humm that was there regardless of what tube I had. I could sometimes get rid of it by giving the top plate a tap... or the transformer a tap... or jiggling a tube. It would just come back a few minutes later. I finally realized it was a loose connection joint at the power tube base where it connects to a bunch of wires. One of the connections had been pulled "out of position" because I had transported it with a large mundorf capacitor loose inside pulling on this wire. After I pinned it back in place with my fingers, it hasn't hummed since.
  
 I transport my Crack very carefully and gently now.


----------



## Loquah

aeolus kratos said:


> Hi everyone,
> 
> I've encountered the first problem with my Crack today after 2 months working perfectly today. After I stopped listening this morning, I noticed the wood base of my Crack had a crack in the 'edge' ( there's a small 'gap' in the corner of the wood base. So I took out the tubes, the plates and use some super-glue to fix the base. After that, I replaced the plate and the tubes, I turned on the Crack again. Then I plugged my T1 into the Crack and...no sound in the left channel, there was only sound coming from the right one. I turned it off, then turned on again, I immediately plugged my T1 back in and the sound was coming from both channels, but as soon as the tubes got a bit warm up, there was a 'buzzing' and no sound from left channel again. I tried another driver tube ( 12AU7 ) only because I don't have any other power tube but my Bendix 6080WB, as well as turning on and off several times but none of them worked.
> 
> ...


 
  


atsq17 said:


> I once couldn't get rid of this annoying humm that was there regardless of what tube I had. I could sometimes get rid of it by giving the top plate a tap... or the transformer a tap... or jiggling a tube. It would just come back a few minutes later. I finally realized it was a loose connection joint at the power tube base where it connects to a bunch of wires. One of the connections had been pulled "out of position" because I had transported it with a large mundorf capacitor loose inside pulling on this wire. After I pinned it back in place with my fingers, it hasn't hummed since.
> 
> I transport my Crack very carefully and gently now.


 
  
 Sounds like a similar issue for you, Kratos. I think the issue might be a cracked / partial solder joint or maybe a loose tube socket like what happened on atsq17's Crack. Hopefully it won't come back again, but if it does your local repairer should be able to fix it fairly easily by just reheating all the solder joints (sounds like a worse / bigger job than it really is) and possibly adding a bit of solder if any of the joints look at all questionable.
  
 PS - looking forward to hearing your thoughts about the T1 mod when we have some time to chat later today!!


----------



## Mingus Ah Um

I'm looking to purchase a couple new tubes for my crack.  I've stuck with the stock tubes for the last five months and am curious to try something new.
  
 I've been wanting to try the Tesla tube out and I've found two different Tesla tubes and I'm wondering if there's any difference between them other than the color of the labeling?
  
http://www.ebay.com/itm/171241597870?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
  
http://www.ebay.com/itm/201108509598?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
  
 Both appear similar to me but I thought I'd ask here before I purchase.


----------



## i luvmusic 2

I finally ordered 2 Mundorf 100uf 400V Film Caps and 1 ALPS Blue velvet Potentiometer just waiting for the reply from the supplier.


----------



## bigfatpaulie

i luvmusic 2 said:


> I finally ordered 2 Mundorf 100uf 400V Film Caps and 1 ALPS Blue velvet Potentiometer just waiting for the reply from the supplier.


 
  
 NICE!!  I did the same upgrade and I found that these upgrades made a significant (positive) difference with my Crack.  Enjoy it!!


----------



## atraf

ALPS Blue velvet  vs Dale 23 Step, I'm thinking about upgrading my crack, what improvement will I get from each?


----------



## i luvmusic 2

I installed this in my Crack and i'am not liking it that much it reduced the BASS and details.The stock POT is not working properly after i uninstalled it that is why i'am getting the ALPS but if that stock pot only works  like before i will reinstall it permanently.


----------



## RonO

I really like the ALPS blue velvet in my amp.  It mitigated the channel imbalance issues I had with the the stock pot.  I cannot say it sounds better, I think it does, but I can say it does not sound worse than the stock pot.  The soldering was a bit tricky, the model ALPS I purchased is just pins, not the rings like the stock, so it takes calm hands and patience to get the connections in place.
  
 edit:spelling


----------



## JamieMcC

i luvmusic 2 said:


> I installed this in my Crack and i'am not liking it that much it reduced the BASS and details.The stock POT is not working properly after i uninstalled it that is why i'am getting the ALPS but if that stock pot only works  like before i will reinstall it permanently.


 

 That pot looks nothing like the attenuators I have seen installed, these are the ones that seem more common


----------



## i luvmusic 2

The benefit that i've got from that Attenuator is balance the Left and Right channel and according to the vendor that Attenuator is Stereo but it could be Mono.


----------



## i luvmusic 2

rono said:


> I really like the ALPS blue velvet in my amp.  It mitigated the channel imbalance issues I had with the the stock pot.  I cannot say it sounds better, I think it does, but I can say it does not sound worse than the stock pot.  The soldering was a bit tricky, the model ALPS I purchased is just pins, not the rings like the stock, so it takes calm hands and patience to get the connections in place.
> 
> edit:spelling


 
 I'am waiting for mine that and Film caps.


----------



## i luvmusic 2

Just got a reply from Parts connexion the POT and CAPS are shipped today.


----------



## Loquah

i luvmusic 2 said:


> The benefit that i've got from that Attenuator is balance the Left and Right channel and according to the vendor that Attenuator is Stereo but it could be Mono.


 
  
 You should get noticeably better clarity compared to the stock pot in addition to the better low volume channel balance.
  
 If yours is installed, I luvmusic 2, you can easily test if it's stereo or mono by disconnecting one of the RCAs while you have music playing. If it's a mono pot you'll still hear sound from both sides in your headphones.


----------



## i luvmusic 2

loquah said:


> i luvmusic 2 said:
> 
> 
> > The benefit that i've got from that Attenuator is balance the Left and Right channel and according to the vendor that Attenuator is Stereo but it could be Mono.
> ...


 
 Ok i disconnected one of RCA input and the sound on that side disappeared plug it back and do the same to the other channel and again the sound from that channel disappeared so meaning it's a STEREO?THANK YOU!


----------



## Loquah

i luvmusic 2 said:


> Ok i disconnected one of RCA input and the sound on that side disappeared plug it back and do the same to the other channel and again the sound from that channel disappeared so meaning it's a STEREO?THANK YOU!


 
  
 You're welcome.
  
 Surprised then that you're not hearing noticeable improvements over stock as this should be giving greater transparency and detail compared to the stock pot.


----------



## liamstrain

In my experience, a poor (cold) solder joint could cause some attenuation and muddiness. I might try reflowing the solder.


----------



## i luvmusic 2

liamstrain said:


> In my experience, a poor (cold) solder joint could cause some attenuation and muddiness. I might try reflowing the solder.


 
 I will give that a try,THANKS!


----------



## i luvmusic 2

loquah said:


> i luvmusic 2 said:
> 
> 
> > Ok i disconnected one of RCA input and the sound on that side disappeared plug it back and do the same to the other channel and again the sound from that channel disappeared so meaning it's a STEREO?THANK YOU!
> ...


 
  The only improvement i hear is the balance in lower volume other than that nothing else except for less bass and details i remember when i had the stock pot the sound is more forward but not anymore with this Attenuator.Do you recall how the stock pot sounds like?I think it's forward sounding.Thanks!


----------



## Loquah

I find the stock pots to be quite good, but with slightly less treble clarity and overall detail than the aftermarket ones I've heard. This all depends on the pot though and the quality of the contact materials used


----------



## i luvmusic 2

I'am not liking this crap i will try the ALPS Blue Velvet i should  have it tomorrow or thursday oh and it should come with Mundorf 100uf 400V Caps.
	

	
	
		
		

		
			





Thanks!


----------



## pdrm360

Recently I've replaced my AQ golden gate RCA cables with premium Hi-Fi interconnect RCA cables.  I’m truly amazed how they improved my Crack’s sound quality.  To my ears change of the sound quality by replacing the cables was clearly more than using different tubes.  It worth every penny that I paid for the cables.


----------



## Jason8777

My Speedball kit comes with these plastic things
  
 .  I'm assuming they're thermal pad. Am I right?  Just want to be sure. Please advise,  Thanks in advance.


----------



## GrindingThud

Mica insulator to keep the transistor from shorting to the heat sink. The washers have a lip also to keep everything from touching.


----------



## Loquah

jason8777 said:


> My Speedball kit comes with these plastic things
> 
> .  I'm assuming they're thermal pad. Am I right?  Just want to be sure. Please advise,  Thanks in advance.


 
  
  


grindingthud said:


> Mica insulator to keep the transistor from shorting to the heat sink. The washers have a lip also to keep everything from touching.


 
  
 Yes. Thermal pad is what they're called in the manual.


----------



## i luvmusic 2

I received the CAPS and ALPS Pot today and i'am surprised how big this cap  it looks small in the pictures.


----------



## Loquah

Yeah. Gets me every time too


----------



## i luvmusic 2

I should be enjoying listening to the Crack not working on the Crack this need to stop.


----------



## trentrosa

I need to replace the octal tube socket on my year old crack, any recommendations? I'm debating between teflon and the glass fibre beltons. The power tube on my crack needs to be in a very definitive position for the amp to function unfortunately, and touching it either kills the amp or a channel, along with bursting my ears in the process.


----------



## audiowize

trentrosa said:


> I need to replace the octal tube socket on my year old crack, any recommendations? I'm debating between teflon and the glass fibre beltons. The power tube on my crack needs to be in a very definitive position for the amp to function unfortunately, and touching it either kills the amp or a channel, along with bursting my ears in the process.


 

 Are you 100% sure you don't have a loose connection on the socket, or elsewhere?  This is the most common cause of the issue you describe.
  
 You can also tighten the socket connections by gently prying the pin forks together a bit in the socket.
  
 Several builders have had issues in their Cracks from "high quality" teflon sockets, so I wouldn't recommend them.


----------



## trentrosa

audiowize said:


> Are you 100% sure you don't have a loose connection on the socket, or elsewhere?  This is the most common cause of the issue you describe.
> 
> You can also tighten the socket connections by gently prying the pin forks together a bit in the socket.
> 
> Several builders have had issues in their Cracks from "high quality" teflon sockets, so I wouldn't recommend them.


 
 I've resoldered the joints twice and the tube is still sensitive to positioning so I'm going to try and replace the socket.


----------



## trentrosa

I dug out a very tiny flat screwdriver and bent the contacts closer together. So far so good, I can grab the tube and rock it round and round without a problem. Thanks audiowize.


----------



## FunyunBreath

audiowize said:


> Are you 100% sure you don't have a loose connection on the socket, or elsewhere?  This is the most common cause of the issue you describe.
> 
> You can also tighten the socket connections by gently prying the pin forks together a bit in the socket.
> 
> Several builders have had issues in their Cracks from "high quality" teflon sockets, so I wouldn't recommend them.


 
  
 I was thinking about upgrading the sockets in my next kit with teflon ones, what are the issues people have had with them?


----------



## atraf

To install the speed or not to Install the speed:  that is the question 
 finally got a normal camera so a few more photos


----------



## kothganesh

atraf said:


> To install the speed or not to Install the speed:  that is the question
> finally got a normal camera so a few more photos
> 
> 
> ...


 
 Oh that should not even be an option, IMO. You SHOULD install it.


----------



## dreame77

Hello everyone!
  
 Recently I ordered my Crack with Speedball upgrade. Few days ago I get Sennheiser HD700 and found them awesome. Now I listen to them through Schiit Modi/Magni and Audinst mx2. The reason I ordered Crack was the article on headfonia.com, there Crack was called almost perfect amp for HD700. As it is mentioned on bottlehead.com, their amps are mostly perfect for Sennheiser headphones. 
  
 BUT, about 50 pages before, here in this thread, it was said that HD has 150 Ohm Impedance which is close to 120 Ohm in Crack. That is why HD700 would not sound good, and for Crack I do need some headphones with 250-600 Ohm. 
  
 In the threads of Sennheiser HD700 and Beyerdynamic T90 I found an opinion that HD700 does not profit from Crack as much as T90 does. Therefore on a system like Modi/Magni T90 and HD700 are comparable and are in the same league, while with Bottlehead Crack T90 became superior to HD700. 
  
 Can you dispel my doubts?


----------



## atraf

kothganesh said:


> Oh that should not even be an option, IMO. You SHOULD install it.


 
  
 O.k I couldn't help it and I glad I did, everything is just better !
 The highs are more crisp maybe too crisp? especially in electronic music maybe, I can't decide yet if its bad or good :O


----------



## pdrm360

dreame77 said:


> Hello everyone!
> 
> Recently I ordered my Crack with Speedball upgrade. Few days ago I get Sennheiser HD700 and found them awesome. Now I listen to them through Schiit Modi/Magni and Audinst mx2. The reason I ordered Crack was the article on headfonia.com, there Crack was called almost perfect amp for HD700. As it is mentioned on bottlehead.com, their amps are mostly perfect for Sennheiser headphones.
> 
> ...


 
  
 I did find the Crack a perfect amp for the HD700; the Crack I had tried, didn't have the Speedball upgrade though.


----------



## dsound

atraf said:


> O.k I couldn't help it and I glad I did, everything is just better !
> The highs are more crisp maybe too crisp? especially in electronic music maybe, I can't decide yet if its bad or good :O


 
 If you want to tame the treble a bit, you can try rolling in an RCA 6as7g.  They are pretty cheap and seem to mellow out the sound of the Crack (to my ears at least).


----------



## pdrm360

dsound said:


> If you want to tame the treble a bit, you can try rolling in an RCA 6as7g.  They are pretty cheap and seem to mellow out the sound of the Crack (to my ears at least).


 
  
 That's what I use, though it's difficult to find a noise free one.


----------



## Nic Rhodes

dreame77 said:


> Hello everyone!
> 
> Recently I ordered my Crack with Speedball upgrade. Few days ago I get Sennheiser HD700 and found them awesome. Now I listen to them through Schiit Modi/Magni and Audinst mx2. The reason I ordered Crack was the article on headfonia.com, there Crack was called almost perfect amp for HD700. As it is mentioned on bottlehead.com, their amps are mostly perfect for Sennheiser headphones.
> 
> ...


 

  The Crack amp excels with high impedance headphones (>300 ohm).


----------



## JamieMcC

pdrm360 said:


> That's what I use, though it's difficult to find a noise free one.


 

 The Russian 6Н13С winged C's should be a good substitute for the RCA's the ones I have tried have all been dead quiet they have the advantage of being inexpensive.


----------



## olegausany

+1


----------



## atraf

dsound said:


> If you want to tame the treble a bit, you can try rolling in an RCA 6as7g.  They are pretty cheap and seem to mellow out the sound of the Crack (to my ears at least).


 
 which one are you talking about there are many RCA 6as7g, clear top, Nos, gray plates... whats the different between them :O 
  


jamiemcc said:


> The Russian 6Н13С winged C's should be a good substitute for the RCA's the ones I have tried have all been dead quiet they have the advantage of being inexpensive.


 
  
 Hum is really an issue for me I need the amp dead silent currently i have hum due lack of DAC and its driving me crazy..
 another thing beside taking the edge of highs i want something to really help the bass to go lower and deeper and i want it to "rumble" my ears
 How is the bass in the  6as7g or  6Н13С? 
 I can't seem to find the The Russian 6Н13С winged C's for sale :O 
  
 Since I am new to this do you usually tube roll the input tube as well?


----------



## JamieMcC

atraf said:


> which one are you talking about there are many RCA 6as7g, clear top, Nos, gray plates... whats the different between them :O
> 
> 
> Hum is really an issue for me I need the amp dead silent currently i have hum due lack of DAC and its driving me crazy..
> ...


 

 Yes you can roll both tubes probably a good start would be to sort out you dac before spending out on a heap of tubes .
  
 Here is a link to  Bottleheads Crack tube rolling thread, if it can run in a crack its most probably in the thread you might come across a description of the perfect combination for you
  
 have fun
  
  
http://bottlehead.com/smf/index.php/topic,663.0.html


----------



## atraf

T


jamiemcc said:


> Yes you can roll both tubes probably a good start would be to sort out you dac before spending out on a heap of tubes .
> 
> Here is a link to  Bottleheads Crack tube rolling thread, if it can run in a crack its most probably in the thread you might come across a description of the perfect combination for you
> 
> ...


 
 Thanks planning to buy the modi in a few days ..


----------



## i luvmusic 2

I did these MOD for the headphone jack and some of the voltage readings went up 10V and some down 3V from my previous voltage reading.Is this normal for this MOD?Thanks!


----------



## dreame77

nic rhodes said:


> The Crack amp excels with high impedance headphones (>300 ohm).


 
 Right now I can still choose which headphones to use. 
 So, the basis is Crack + SB. 
 As for headphones I could afford some in the price range 500€, where Beyerdynamic T90 and Sennheiser HD700 are. 
 Are there any other better headphones within this price range? 
 And which headphones would sound best with Crack? (exclude HD800, it costs 1200€ new)


----------



## i luvmusic 2

My Crack is dead quiet from the beginning i don't think you can judge the tube just like that,For example i have this Chatham 6AS7G that have a slight Hum but if i plug it in the crack it's quiet.IMO you need to check the amp maybe some loose connection/cold solder wire routing.


----------



## i luvmusic 2

I changed the attenuator with a ALPS pot the sound is nice i prefer the ALPS.


----------



## i luvmusic 2

atraf said:


> kothganesh said:
> 
> 
> > Oh that should not even be an option, IMO. You SHOULD install it.
> ...


 
 Hi,
   After you did the headphone jack mod did you do a voltage reading and did you noticed any voltage changes from the previous reading you have.Mine some went up 10V and some went down 3V.Thanks!


----------



## diaBoliQu3

atraf said:


> T
> Thanks planning to buy the modi in a few days ..


 

 May I know why Modi?


----------



## trentrosa

I rolled a Tung Sol 5998 into my Crack, amazing clarity and frequency extension. The treble was a little to crisp for my tastes, however either my ears are adjusting slowly or the tube is breaking in, for it's getting better.


----------



## Nic Rhodes

dreame77 said:


> Right now I can still choose which headphones to use.
> So, the basis is Crack + SB.
> As for headphones I could afford some in the price range 500€, where Beyerdynamic T90 and Sennheiser HD700 are.
> Are there any other better headphones within this price range?
> And which headphones would sound best with Crack? (exclude HD800, it costs 1200€ new)


 

 Personally I would look at one of the 600 ohm Beyers or high impedance Sennheisers. I wasn't a fan of the 700 personally and not for OTLs.


----------



## JamieMcC

dreame77 said:


> Right now I can still choose which headphones to use.
> So, the basis is Crack + SB.
> As for headphones I could afford some in the price range 500€, where Beyerdynamic T90 and Sennheiser HD700 are.
> Are there any other better headphones within this price range?
> And which headphones would sound best with Crack? (exclude HD800, it costs 1200€ new)


 
  
 The Beyer T1's pair very well the Crack and will also continue to scale should you decide to go down the Cracks upgrade path  in the future. My HD650's have been gathering dust for some time now. They often come up now discounted around £550 new on the site we publicly must not mention and sometimes Amazon runs promotion deals but they only seem to last a few hours so it can be worth checking regularly.


----------



## atraf

i luvmusic 2 said:


> Hi,
> After you did the headphone jack mod did you do a voltage reading and did you noticed any voltage changes from the previous reading you have.Mine some went up 10V and some went down 3V.Thanks!


 
  
 I did noticed some voltage changes in some readings, didn't write it down so I didn't remember but all were very slight around 1-2 V, and as far as I know as long its in the 10-15% range its ok, the only drastic change was that terminals 6 and 10 are now grounded and in the resistance test the result is 0.
  
Quote:


diaboliqu3 said:


> May I know why Modi?


 
 My 2 candidates were Modi vs ODAC, after reading and asking quite a lot about them I decided it that I might not like how the ODAC sound, I like the modi's looks and price, the crack build and the headphone emptied me from cash  
 I can see in your signature you have the Modi, are you asking that because you don't like what you got? 
 Mostly


----------



## diaBoliQu3

atraf said:


> I did noticed some voltage changes in some readings, didn't write it down so I didn't remember but all were very slight around 1-2 V, and as far as I know as long its in the 10-15% range its ok, the only drastic change was that terminals 6 and 10 are now grounded and in the resistance test the result is 0.
> 
> Quote:
> My 2 candidates were Modi vs ODAC, after reading and asking quite a lot about them I decided it that I might not like how the ODAC sound, I like the modi's looks and price, the crack build and the headphone emptied me from cash
> ...


 

 I don't know what is your sound preferences but I would pick ODAC anytime. Modi is a good DAC for it's price but IMO ODAC is better. I did post about my impressions for these two DAC few pages back. But I damn agree Modi looks better than ODAC.
  
 BTW, I understand how your wallet become thin in short time. Lol...


----------



## pdrm360

dreame77 said:


> Right now I can still choose which headphones to use.
> So, the basis is Crack + SB.
> As for headphones I could afford some in the price range 500€, where Beyerdynamic T90 and Sennheiser HD700 are.
> Are there any other better headphones within this price range?
> And which headphones would sound best with Crack? (exclude HD800, it costs 1200€ new)


 
  
 IMO: HD650 or HD600


----------



## pdrm360

^^ You can also consider Beyer DT880 and T1, I've never been a fan of the T90.


----------



## dreame77

jamiemcc said:


> The Beyer T1's pair very well the Crack and will also continue to scale should you decide to go down the Cracks upgrade path  in the future. My HD650's have been gathering dust for some time now. They often come up now discounted around £550 new on the site we publicly must not mention and sometimes Amazon runs promotion deals but they only seem to last a few hours so it can be worth checking regularly.


 
 I just found one pair of T1 for 700€, probably could try it. 
 Especially if they are significantly better than HD700(500€) and T90(400€).


----------



## Nic Rhodes

I bought my T1 for £400 on ebay but many examples at £500 - £550


----------



## dreame77

Ok, moving forward!
 If one would compare T1 and HD800 on Crack SB?
 Are both of them significantly better than T90 and HD700?


----------



## i luvmusic 2

atraf said:


> i luvmusic 2 said:
> 
> 
> > Hi,
> ...


 
 Thanks!the voltage changes are slight and still with in the spec. and T6,T10 are now 0 before they are 2.4K.


----------



## i luvmusic 2

I found the problem why both tubes spark during start up.A piece of small cut-off wires that i cut after soldering got stack somewhere under the amp so when i flipped the amp again that small piece of wire fell off,No more tube sparking during start up.Speedball time


----------



## pdrm360

dreame77 said:


> Ok, moving forward!
> If one would compare T1 and HD800 on Crack SB?
> Are both of them significantly better than T90 and HD700?


 
  
 Yes, they both are significantly better than T90 and HD700.


----------



## dreame77

What is more interesting now, is changes in sound. 
 Did anyone compared Crack with Magni? Or oven better Modi/Magni vs Modi/Crack ?


----------



## Loquah

dreame77 said:


> Ok, moving forward!
> If one would compare T1 and HD800 on Crack SB?
> Are both of them significantly better than T90 and HD700?


 
  
  


pdrm360 said:


> Yes, they both are significantly better than T90 and HD700.


 
  
 Agree that T1 is superior to T90. Can't comment on HD700, but the T1 with the Crack is simply outstanding and may be more enjoyable for many than the HD800 despite HD800's technical superiority. T1 is just such a good balance of technicality and musicality


----------



## i luvmusic 2

Speedball is done and installed and it's WOW for me loved it.


----------



## i luvmusic 2

For those of you who upgraded the Electrolytic to Film Caps how did you guys attach those big caps on the plate and what materials did you used?I have 2 Mundorf 100uf 400V film Caps that i need to install,these things take up a lot of space.Thanks!


----------



## Loquah

i luvmusic 2 said:


> For those of you who upgraded the Electrolytic to Film Caps how did you guys attach those big caps on the plate and what materials did you used?I have 2 Mundorf 100uf 400V film Caps that i need to install,these things take up a lot of space.Thanks!


 
  
 You can buy various adhesive tie-downs like this one - you'd need a longer cable-tie that the one shown though. One small recommendation is to mount the anchor point in advance and give it some time before attaching the weight of the capacitors so that the adhesive can really grip to the chassis plate before being pulled on.


----------



## Aeolus Kratos

dreame77 said:


> Ok, moving forward!
> If one would compare T1 and HD800 on Crack SB?
> Are both of them significantly better than T90 and HD700?


 

  
 Get both of them and you're more than ready to rock all night with your Crack


----------



## Armaegis

loquah said:


> You can buy various adhesive tie-downs like this one - you'd need a longer cable-tie that the one shown though. One small recommendation is to mount the anchor point in advance and give it some time before attaching the weight of the capacitors so that the adhesive can really grip to the chassis plate before being pulled on.


 
  
 Or scrape off the foam adhesive and epoxy that sucker down.


----------



## pdrm360

aeolus kratos said:


> Get both of them and you're more than ready to rock all night with your Crack


 
  
 +1


----------



## dreame77

loquah said:


> Agree that T1 is superior to T90. Can't comment on HD700, but the T1 with the Crack is simply outstanding and may be more enjoyable for many than the HD800 despite HD800's technical superiority. T1 is just such a good balance of technicality and musicality


 
 Thank you! Could you comment on this article of comparison between T1 and HD800 http://www.headfonia.com/hd800-t1/ ?


aeolus kratos said:


> Get both of them and you're more than ready to rock all night with your Crack


 
 Yeah, that is a good Idea! If I only had enough money... And I generally prefer to have only one pair of headphones.


----------



## atraf

diaboliqu3 said:


> I don't know what is your sound preferences but I would pick ODAC anytime. Modi is a good DAC for it's price but IMO ODAC is better. I did post about my impressions for these two DAC few pages back. But I damn agree Modi looks better than ODAC.
> 
> BTW, I understand how your wallet become thin in short time. Lol...


 
  
 What do you like in the ODAC over the Modi ? 
 I basically like deep bass and wide sound stage, I am afraid the ODAC will make my sound dry, bright and boring :O 
 I mostly listen to electronic, and only in this genre I currently not fully satisfied.
 And the most important thing for me is SILENT, I have a terrible hum from my laptop right now It drives me crazy, but I assume both ODAC and Modi will fix it so..


----------



## Loquah

dreame77 said:


> Thank you! Could you comment on this article of comparison between T1 and HD800 http://www.headfonia.com/hd800-t1/ ?
> Yeah, that is a good Idea! If I only had enough money... And I generally prefer to have only one pair of headphones.


 
  
 Wow. I really can't agree with the comments in the Headfonia article. I think source chain must have been playing a part because every time I've tried to like the HD800 I have found them drier and cooler sounding than the T1s and I've really wanted to like the HD800s so there's no bias here. The HD800s are exceptional, but they're just not warmer than the T1s!? I can only assume there was some synergy where the sources used were emphasising something about the T1s and /or neutralising some of the HD800's potentially challenging characteristics.
  
 Given that we're talking about the Crack here, I'll leave it to others to comment specifically on the HD800 vs T1 comparison with the Crack because it's been way too long since I heard the HD800 with the Crack.


----------



## i luvmusic 2

loquah said:


> i luvmusic 2 said:
> 
> 
> > For those of you who upgraded the Electrolytic to Film Caps how did you guys attach those big caps on the plate and what materials did you used?I have 2 Mundorf 100uf 400V film Caps that i need to install,these things take up a lot of space.Thanks!
> ...


 
 Thanks!


----------



## JamieMcC

Who would have thought my thousandth post and I'm a bit of a antisocial git at heart, it must be the Bottlehead effect.
  
  


loquah said:


> Wow. I really can't agree with the comments in the Headfonia article. I think source chain must have been playing a part because every time I've tried to like the HD800 I have found them drier and cooler sounding than the T1s and I've really wanted to like the HD800s so there's no bias here. The HD800s are exceptional, but they're just not warmer than the T1s!? I can only assume there was some synergy where the sources used were emphasising something about the T1s and /or neutralising some of the HD800's potentially challenging characteristics.
> 
> Given that we're talking about the Crack here, I'll leave it to others to comment specifically on the HD800 vs T1 comparison with the Crack because it's been way too long since I heard the HD800 with the Crack.


 
  
 Interesting I had not seen the article and while I have never heard the HD800's I do know my T1's currently don't sound as they describe them in the article I can only assume due to the references of hot treble and lack of warmth in vocals the equipment they used was not the best synergistically with the T1.
  
 I have experienced similar traits my own T1's on different amps so know what they can sound like poorly matched however with my Crack in its current guise that description does not fit with what I am experiencing most certainly there is no hot treble and vocal presentation is really just sublime by far the best I have heard so far, vocals that can be both delicate, nuanced and rich in texture & soul help to create a illusion of presence the like of which I have only heard with the T1's.


----------



## Aeolus Kratos

dreame77 said:


> Thank you! Could you comment on this article of comparison between T1 and HD800 http://www.headfonia.com/hd800-t1/ ?
> Yeah, that is a good Idea! If I only had enough money... And I generally prefer to have only one pair of headphones.


 

 If I have to choose just ONE pair of headphones, it would be the T1. The T1 is the more 'complete' and relaxing sounding headphone to me, therefore it's better for general listening than the HD800.
  
 About the HD800 vs T1 comparison, I think I should tell my little story which I already posted somewhere on head-fi too:
  
 I've been a fan of HD800s for over two years now, and I have to admit that I hadn't heard the T1 when I was having the HD800s. I had a pair of HD800s, one has the early and one has the late serial number ( 2xxxx ) . Just recently, I bought a T1 from buydig. When I heard the T1 with my Bottlehead Crack for the 1st time, I nearly couldn't believe my ears, the T1 was better in many genres than the HD800s ( except for classical ), especially the midrange. I sold one of my HD800s right away.
  
 So I guess maybe the HD800s are more superior in terms of 'accuracy' and 'technical factor', but I've never had the same feeling when I listened to vocals with the HD800s as I had with the T1s. I don't care if this headphone has a more balanced FR, it has a bigger soundstage or it provides a more 'accurate' sound, the only thing I care is how I feel about the music. We're all here, sharing experiences to each other on our passion, the love for 'music', NOT 'sound'. As long as I enjoy and have a good time listening to music, everything else doesn't matter to me. In that region, the T1s, IMHO, actually do a better job than the HD800s.
  
 I'm not saying the T1s sound 'better' than the HD800s, they just match my 'taste' perfectly and give me the enjoyment I've never had with the HD800s.
  
 In conclusion, I think each headphone has its own presentation. You can not say which headphone is BETTER. I personally use my HD800 for listening to classical ( which is not my main genre ), being the 'reference' headphone and testing, but I use the T1 whenever I want to just sit back, relax and ENJOY my music. The HD800 can not give me goosebumps or the emotion when I listen to my favorite music - vocals and country, mostly, like the T1 does.
  
 The argument between the T1 and the HD800 will last forever...


----------



## diaBoliQu3

atraf said:


> What do you like in the ODAC over the Modi ?
> I basically like deep bass and wide sound stage, I am afraid the ODAC will make my sound dry, bright and boring :O
> I mostly listen to electronic, and only in this genre I currently not fully satisfied.
> And the most important thing for me is SILENT, I have a terrible hum from my laptop right now It drives me crazy, but I assume both ODAC and Modi will fix it so..


 
 Detail, clean sound, and wider with airy music. I agree in EDM, Modi perform better unless you can find a tube that can tame ODAC brightness. BTW, I agree that ODAC is bright but I don't think it's dry. In fact they sound very musical IMO. For your kind of genre, I think Modi is the best DAC assuming you won't change your tube.


----------



## atraf

Everything is an option in the future including tube rolling, everything is new to me and since i am low on budget I currently want to buy a DAC and continue from there.
 Thanks for your opinion I guess the best way for me to know whats good for me is to try it by myself I hope I will manage to find a way to do it in my country before I buy.


----------



## i luvmusic 2

For the Film Caps are they polarize?I was looking at them to see if  it have a Positive and negative on them and don't see any signs. Thanks!


----------



## Loquah

i luvmusic 2 said:


> For the Film Caps are they polarize?I was looking at them to see if  it have a Positive and negative on them and don't see any signs. Thanks!


 
  
 Not strictly speaking, but some (like the Auricaps) do have a recommended orientation. Best to search around for discussions about your specific caps to see if there is a recommended direction of flow for them.


----------



## i luvmusic 2

loquah said:


> i luvmusic 2 said:
> 
> 
> > For the Film Caps are they polarize?I was looking at them to see if  it have a Positive and negative on them and don't see any signs. Thanks!
> ...


 
 Mine Is 


loquah said:


> i luvmusic 2 said:
> 
> 
> > For the Film Caps are they polarize?I was looking at them to see if  it have a Positive and negative on them and don't see any signs. Thanks!
> ...


 
 Mine is Mundorf 100uf 400V M-CAP MKP Series,THANK YOU!


----------



## i luvmusic 2

I have done all my Upgrades now i need to stop here because some of these upgrades are not much of a defference compared to CRACK with SPEEDBALL all i have to do now is finish the BASE and enjoy these  wonderful Amplifier.Here is mine.Oh and i'am waiting for the aluminum volume knob maybe this upgrade will make it sound a lot better.LOL
	

	
	
		
		

		
			




  







 I'am just kidding about the Knob.


----------



## Loquah

Looking great!!


----------



## diaBoliQu3

Oh lord... That's a fat caps! BTW, is it okay if I use floor coating paint to paint my base? It's like a varnish too when applied on wood.


----------



## i luvmusic 2

It's a challenged to put those Caps under the amp.
  
 THANK YOU!


----------



## RonO

Don't knock the aluminum knob! My first one improved the sound 1.03%! I got a new one recently when I replaced the stock POT with an ALPS, and it was better than the first knob, at 1.4333% improvement!  Knobs rock!


----------



## liamstrain

atraf said:


> What do you like in the ODAC over the Modi ?
> I basically like deep bass and wide sound stage, I am afraid the ODAC will make my sound dry, bright and boring :O
> I mostly listen to electronic, and only in this genre I currently not fully satisfied.
> And the most important thing for me is SILENT, I have a terrible hum from my laptop right now It drives me crazy, but I assume both ODAC and Modi will fix it so..


 
  
 IMO - Any sufficiently competent DAC will not audibly sound different than another. If it does, then someone is screwing with it and should be knocked off the list for consideration. Don't use components for EQ. Either use an actual EQ, or buy headphones whose sound signature you like. If nothing else, that saves you money not having to buy a different dac if you swap amps, or whatever changes you might make down the line.


----------



## atsq17

liamstrain said:


> IMO - Any sufficiently competent DAC will not audibly sound different than another. If it does, then someone is screwing with it and should be knocked off the list for consideration. Don't use components for EQ. Either use an actual EQ, or buy headphones whose sound signature you like. If nothing else, that saves you money not having to buy a different dac if you swap amps, or whatever changes you might make down the line.


 
  
 Hi, 
  
 I am not sure if you are talking theoretically or from experience but having owned or tried a series of DACs including the Modi, pupDAC, Concero HP, Audio GD NFB2, DAC19, Neko D100 Mk2, I can say unequivocally that they almost all had a distinct characteristic or sounded different from each other. 
  
 Using the Modi as a baseline, the pupDAC had more space and a slightly wider soundstage but the instruments and individual sounds were more recessed. The concero HP seemed (maybe with my equipment at the time - Burson Soloist) treble centric but I didn't give it much time to be honest. 
  
 Having recently faced off the D100 Mk2 against the DAC19 and NFB2 using my recabled T1 and Crack (using Black Cat Silverstar USB and Audiophilleo2 transport), the D100Mk2 had a very smooth addictive analog sound that one could listen to all day. The DAC19 had a CLEARLY wider soundstage and bigger sounds and more details (which is why I have one on order). The NFB2 was a jack of all trades with a nice presentation (not as good as D100 Mk2), a wider soundstage than the D100Mk2 but less than the DAC19. Similar level of details to the D100Mk2 (both inferior to the DAC19) but they emphasized different parts of the sound. 
  
 I was also testing the TH900 and LCD-X at a shop with the AK120 Mk2 player plugged into the Bakoon HPA21. It was good but when we plugged in the Chord Hugo DAC it sounded MUCH MUCH better. I used to think that I would not need anything better than Modi but after trying it out with high end equipment, I realized I was wrong. At least to my ears.


----------



## liamstrain

I understand where you are coming from, and I do wonder how many of those listening tests were done in a controlled (preferably double blind) way.
  
 DACs should be audibly transparent. Totally. Most are, in my experience - and after some significant testing, I got rid of my very expensive DAC's and replaced them with lower price, but similarly spec'd options. (My ODAC, Yulong D100 Mk1, and AMB Gamma all sound identical once output voltages are accounted for - this was also true of my Benchmark DAC 1, and a few others I've owned and since sold).  

 If you are finding some are not, then they are not doing their only function as a DAC properly. 
  
 And my larger point stands as well - don't use equipment selection as an EQ.


----------



## i luvmusic 2

How long it would take to burn-in a newly installed film cap on crack?
 I don't know if this thing is sounding better or it's just me imagining.


----------



## atsq17

liamstrain said:


> I understand where you are coming from, and I do wonder how many of those listening tests were done in a controlled (preferably double blind) way.


 
  
 The tests with the Crack were very controlled and involved 2 other people who all tested and came to their own conclusions. We weren't trying to find every last bit of difference between the DACs so we didn't do double blind although we have done so before with stuff like low end USB cables (was VERY hard to tell). We only did so after we couldn't tell by just switching them out. 
  
 With the DAC changes, we were looking for big differences (so we could sell the one we didn't like as much). All the differences I described to you was clear as night and day and didn't require double blind. It was almost like switching headphones. We were literally hearing completely different things. 
  
 I do get what you are saying theoretically but it's hard to define "transparent" as it still implies that there is a control standard that we are aiming for. How does one define that exactly? I think that people can get two different setups to have the same frequency chart and still sound different (just an educated guess). I am a believer that our measuring equipment is still not accurate enough to capture every bit of information when it comes to reproduced sound. Otherwise people WOULD be creating "perfect" DACs and then releasing variations according to preference. 
  
 Anyway, I think you have a fair point from a theoretical perspective but my experience has shown to me that DACs do make a huge difference to sound and most sound different. I must admit that when I was playing around with low to mid-fi it was much harder to tell. Once I got more "transparent" stuff, every little change (even the change to Audiophilleo or the addition of a USB power LPS) was audible. Some more than others.


----------



## JamieMcC

i luvmusic 2 said:


> How long it would take to burn-in a newly installed film cap on crack?
> I don't know if this thing is sounding better or it's just me imagining.


 

 With your films I would say expect to hear any changes take place during the first 40-100hrs of use after which you could consider them burnt in.
  
 I tend to put the music library on shuffle, plug a old pair of head phones and some cheap tubes in and leave the amp running for a few days depending on the ambient temperature to get the burn in done. Being a little paranoid I always place a smoke detector/alarm on the shelf above the amp. But have experienced no problems letting it run 24/7 for four or five day stretches.


----------



## atraf

Decision has been made, Schiit Modi is on his way to me.
  
 In the mean time Morrow Ma-1 RCA cables have arrived today, build quality seems pretty darn good specially the connectors though the sleeving on the cable is pretty big compared to the inner core therefore the cable look flat and its a bit flimsy, the width of the cable is roughly 12 mm. 
 Sound wise? well I can't tell a difference from my cheap interconnect to this one, maybe in the future, I don't know if burning will do anything but morrow recommend burn in for the cable and supplied 5 pages on the entire thesis on how  burn in properly, so i guess I shall see..


----------



## i luvmusic 2

jamiemcc said:


> i luvmusic 2 said:
> 
> 
> > How long it would take to burn-in a newly installed film cap on crack?
> ...


 
 So far i don't think the caps have really improved the sound other than smooth the sound a little bit or i could be wrong,THANK YOU!


----------



## i luvmusic 2

atraf said:


> Decision has been made, Schiit Modi is on his way to me.
> 
> In the mean time Morrow Ma-1 RCA cables have arrived today, build quality seems pretty darn good specially the connectors though the sleeving on the cable is pretty big compared to the inner core therefore the cable look flat and its a bit flimsy, the width of the cable is roughly 12 mm.
> Sound wise? well I can't tell a difference from my cheap interconnect to this one, maybe in the future, I don't know if burning will do anything but morrow recommend burn in for the cable and supplied 5 pages on the entire thesis on how  burn in properly, so i guess I shall see..


 
  


atraf said:


> Decision has been made, Schiit Modi is on his way to me.
> 
> In the mean time Morrow Ma-1 RCA cables have arrived today, build quality seems pretty darn good specially the connectors though the sleeving on the cable is pretty big compared to the inner core therefore the cable look flat and its a bit flimsy, the width of the cable is roughly 12 mm.
> Sound wise? well I can't tell a difference from my cheap interconnect to this one, maybe in the future, I don't know if burning will do anything but morrow recommend burn in for the cable and supplied 5 pages on the entire thesis on how  burn in properly, so i guess I shall see..


 
 I built a cable like that for under(2 ft) CAD $15 (REAN RCA Jack,techFlex cable sleeve and Mogami 2534).


----------



## adamaley

Way to get the thread on track guys.


----------



## i luvmusic 2

Is it necessary for me to install a coupling caps for these?
 What are the values for the Coupling caps that i need for my caps(please see pictures)? 
 What are the benefits of using a coupling caps?
 Is there any impact in sound? 
  
 I hope this questions will put us back in track.......
	

	
	
		
		

		
		
	


	



 Thanks!


----------



## diaBoliQu3

liamstrain said:


> IMO - Any sufficiently competent DAC will not audibly sound different than another. If it does, then someone is screwing with it and should be knocked off the list for consideration. Don't use components for EQ. Either use an actual EQ, or buy headphones whose sound signature you like. If nothing else, that saves you money not having to buy a different dac if you swap amps, or whatever changes you might make down the line.


 
 When they not compared side by side, I heard minimal differences. It's not that I can't live either with UD100, Modi or ODAC. But when they compared side by side, I say it's pretty obvious. Mind set or ear set, say whatever you want. 
	

	
	
		
		

		
		
	


	




 My expectation is ODAC perform worst than Modi but end up I prefer ODAC afterall.
  
 As you were saying, the complete rig play important parts. However in my case, rig as per siggy I stand firm with *my setup plus music preferences *that ODAC is better than Modi.


----------



## liamstrain

diaboliqu3 said:


> But when they compared side by side, I say it's pretty obvious.


 
  
 Many DAC's do not output the same voltage at the line out. So hearing a difference would be expected (just as not doing level matching shows obvious differences in other "tests") - but those "obvious differences" usually vanish once properly level matched. 
  
 Anyway... enjoy your new rig. I don't think you'll be disappointed.


----------



## JamieMcC

i luvmusic 2 said:


> Is it necessary for me to install a coupling caps for these?
> What are the values for the Coupling caps that i need for my caps(please see pictures)?
> What are the benefits of using a coupling caps?
> Is there any impact in sound?
> ...


 
  
 Your Mundorf caps should bring a noticeable improvement without any bypassing.. I would suggest if your not hearing a improvement after fitting them then something else in your system is probably a limiting factor. With those same caps (I have some) and good tubes you really should be onto a winner.


----------



## trentrosa

jamiemcc said:


> Your Mundorf caps should bring a noticeable improvement without any bypassing.. I would suggest if your not hearing a improvement after fitting them then something else in your system is probably a limiting factor. With those same caps (I have some) and good tubes you really should be onto a winner.



I installed those exact caps awhile back. It was a very noticeable improvement.


----------



## i luvmusic 2

Maybe it's too early for me to judge the caps i just installed it last night,However i tried listening to the amp i noticed that the amp is not sounding more forward like before i know when i just installed the SB it sounded like crisp,bright,warm(i don't know the proper term for it)  and more forward but now it sound smoother.Or it could be just  me.Did you guys experienced like what i'am experiencing?Can someone tell me what it sound like after you guys installed the CAPS and Speedball.Thanks!.


----------



## i luvmusic 2

The way i installed the CAPS by facing the logo from left to right  the lead on the left is on the negative side where the stock cap was and the right  lead is on the positive side of the stock cap and it's the same orientation for the other cap.
 How did you guys orient your caps?
 Does the orientation of the caps matters?
 Thank You!


----------



## diaBoliQu3

liamstrain said:


> Many DAC's do not output the same voltage at the line out. So hearing a difference would be expected (just as not doing level matching shows obvious differences in other "tests") - but those "obvious differences" usually vanish once properly level matched.
> 
> Anyway... enjoy your new rig. I don't think you'll be disappointed.


 

 Yup... You're right about that.


----------



## trentrosa

i luvmusic 2 said:


> The way i installed the CAPS by facing the logo from left to right  the lead on the left is on the negative side where the stock cap was and the right  lead is on the positive side of the stock cap and it's the same orientation for the other cap.
> How did you guys orient your caps?
> Does the orientation of the caps matters?
> Thank You!


 
 Electrically, the orientation does not matter. As stated earlier there is occasionally a recommended orientation, however I don't go out of my way to achieve it, for I can't tell the difference.


----------



## liamstrain

Electrolytic capacitors definitely need to be installed the correct direction (or they go boom). However, most of the capacitors like the Mundorfs are bi-polar, and it generally* doesn't matter which way you install them.
  
 * some people suggest there might be a reason to orient them specifically. This thread at DIY audio covers some of that. 
 http://www.diyaudio.com/forums/parts/7593-black-gate-super-e-caps-8.html#post121850


----------



## skeptic

Ideally, to minimize noise, the lead connected to the inner foil of the cap is what you want as the cap's output. 

Some manufacturers specify this. There is also a thread on the bh site where PJ described an experiment you can perform to figure it out. Like trentrosa though, I've never been able to hear any difference when flipping the orientation of film caps.


----------



## i luvmusic 2

Thank you! all for the info...


----------



## grrraymond

Hi all. Due to a new addition to the family, my headphone days are sadly over. I've put my SB'd cap-modded Crack, my HD650s and a couple of tubes (GEC brown base & TS 5998) on eBay UK. They're all pretty cheap. 200 quid for the Crack. 90 for the phones. 40 for the tubes. They've just got to make way. Pretty gutted to be honest as the SB Crack + GEC & E80CC + HD650s are basically the best I've ever heard music but yeah, a bittersweet feeling, I suppose.


----------



## adamaley

What's your eBay username?


----------



## Aeolus Kratos

grrraymond said:


> Hi all. Due to a new addition to the family, my headphone days are sadly over. I've put my SB'd cap-modded Crack, my HD650s and a couple of tubes (GEC brown base & TS 5998) on eBay UK. They're all pretty cheap. 200 quid for the Crack. 90 for the phones. 40 for the tubes. They've just got to make way. Pretty gutted to be honest as the SB Crack + GEC & E80CC + HD650s are basically the best I've ever heard music but yeah, a bittersweet feeling, I suppose.


 

 Below are the links to the bidding of the Crack and the GEC tube grrraymond is referring to, just in case someone needs it:
  
 http://www.ebay.co.uk/itm/Bottlehead-Crack-OTL-Headphone-Amplifier-/161400771692?pt=UK_AudioTVElectronics_HomeAudioHiFi_Amplifiers&hash=item25943c546c
  
 http://www.ebay.co.uk/itm/GEC-Brown-Base-6AS7G-A1834-CV2523-/161399864800?pt=UK_Sound_Vision_Valves_Vacuum_Tubes&hash=item25942e7de0


----------



## Armaegis

grrraymond said:


> Hi all. Due to a new addition to the family, my headphone days are sadly over. I've put my SB'd cap-modded Crack, my HD650s and a couple of tubes (GEC brown base & TS 5998) on eBay UK. They're all pretty cheap. 200 quid for the Crack. 90 for the phones. 40 for the tubes. They've just got to make way. Pretty gutted to be honest as the SB Crack + GEC & E80CC + HD650s are basically the best I've ever heard music but yeah, a bittersweet feeling, I suppose.


 
  
  
 Congrats on the new addition (I'm going to assume a baby and not an overactive puppy or something 
	

	
	
		
		

		
		
	


	




). PM sent.


----------



## JamieMcC

Congrats grrraymond on new priorities, give it a year of so and you can be a born again headfier!
  
 Best of luck for your auction sells.
  
 Jamie


----------



## Keithpgdrb

grrraymond said:


> Hi all. Due to a new addition to the family, my headphone days are sadly over. I've put my SB'd cap-modded Crack, my HD650s and a couple of tubes (GEC brown base & TS 5998) on eBay UK. They're all pretty cheap. 200 quid for the Crack. 90 for the phones. 40 for the tubes. They've just got to make way. Pretty gutted to be honest as the SB Crack + GEC & E80CC + HD650s are basically the best I've ever heard music but yeah, a bittersweet feeling, I suppose.


 
 also a new recent father, you should hold on to your ****.  Its pretty heavenly to take even 1/2 hour to yourself to listen after doing all the parent stuff.  Its important not to give up everything just because you have a kid.  your still you, and you still enjoy what you enjoy.  Now, if you need the money, thats different.  then ignore me.


----------



## head-hi

keithpgdrb said:


> also a new recent father, you should hold on to your ****.  Its pretty heavenly to take even 1/2 hour to yourself to listen after doing all the parent stuff.  Its important not to give up everything just because you have a kid.  your still you, and you still enjoy what you enjoy.  Now, if you need the money, thats different.  then ignore me.


 

 What he said.


----------



## pdrm360

grrraymond said:


> Hi all. Due to a new addition to the family, my headphone days are sadly over. I've put my SB'd cap-modded Crack, my HD650s and a couple of tubes (GEC brown base & TS 5998) on eBay UK. They're all pretty cheap. 200 quid for the Crack. 90 for the phones. 40 for the tubes. They've just got to make way. Pretty gutted to be honest as the SB Crack + GEC & E80CC + HD650s are basically the best I've ever heard music but yeah, a bittersweet feeling, I suppose.


 


adamaley said:


> What's your eBay username?


 
  
 and password 
	

	
	
		
		

		
		
	


	




​


----------



## skeptic

keithpgdrb said:


> also a new recent father, you should hold on to your ****.  Its pretty heavenly to take even 1/2 hour to yourself to listen after doing all the parent stuff.  Its important not to give up everything just because you have a kid.  your still you, and you still enjoy what you enjoy.  Now, if you need the money, thats different.  then ignore me.


 
  
 Ditto that if finances permit!  Plus, a couple of years down the road, it is just incredibly gratifying to get to share this hobby and your self built amp(s) with your little one(s).  If I fire up the mainline and hand over my hd800's, my 4 year old will sit quietly and soak in the tunes for a good 15-20 minutes before I can pry them away from her.  My wife indulges, but can't relate to, my love of hifi headphones, but my kid clearly gets it and is thrilled by any opportunity to listen to the main rig.


----------



## JamieMcC

skeptic said:


> Ditto that if finances permit!  Plus, a couple of years down the road, it is just incredibly gratifying to get to share this hobby and your self built amp(s) with your little one(s).  If I fire up the mainline and hand over my hd800's, my 4 year old will sit quietly and soak in the tunes for a good 15-20 minutes before I can pry them away from her.  My wife indulges, but can't relate to, my love of hifi headphones, but my kid clearly gets it and is thrilled by any opportunity to listen to the main rig.


 

 +1
  
 Mine as well, though as my rig is in the bed room any initial quiet listening often evolves into bouncing and dancing on the bed whilst wearing them while I nervously cosset the cable amp end, luckily its a long cable. But a joy to watch.


----------



## i luvmusic 2

Indeed HD 650 and Crack sounds really good.


----------



## FunyunBreath

+1
  
 Actually, the last meet I was at I compared my 650/crack against someone else's balanced 650 and Mjolnir combo and liked the Crack more. Saved me from getting the upgrade itch with the 650's


----------



## grrraymond

Thanks for the kind words, guys. I might be back in the game somewhere down the line but my listening den has bitten the dust and there's nowhere else I feel I can store my gear safely or without getting my ear bent about it! I'll be back. Thanks for all the help, support and discussion over the last year or so. Keep up the good fight!


----------



## adamaley

Well who may this be?

  
 Look who joined the party.
  
 And nicely asked for his place in the socket of fame.

  
 Loving the new member of the family.


----------



## trentrosa

funyunbreath said:


> +1
> 
> Actually, the last meet I was at I compared my 650/crack against someone else's balanced 650 and Mjolnir combo and liked the Crack more. Saved me from getting the upgrade itch with the 650's




I was actually considering a Mjolnir to use balanced as a solid state setup to use along with my Crack, for a different kind of sound. However I do love my Crack, and was wondering if I would like the Mjolnir too.


----------



## FunyunBreath

The Mjolnir/650 sounded great, but I remember thinking "this just doesn't quite have that rich, full bodied tone that the Crack does"
  
 It was a while ago so my memories of the comparison are fading a bit, but from what I remember the Mjolnir outdid the Crack in terms of punch, speed, and had slightly more clarity (only a bit). And the Crack had a more robust, smooth, full-bodied sound.
  
 I think you would definitely like the Mjolnir, it's a great SS amp.


----------



## guirr

Anyone got the PDF included on the CD? I don't have a disc drive


----------



## pdrm360

guirr said:


> Anyone got the PDF included on the CD? I don't have a disc drive


 
 PM'd


----------



## bigfatpaulie

guirr said:


> Anyone got the PDF included on the CD? I don't have a disc drive


 
  
 I think you should ask Bottlehead as the manual is copyrighted.  Doc has been on here before asking people to not distribute the manual.


----------



## Doc B.

We are happy to send a link to those who have purchased a kit from us and need a copy of the manual. Contact Eileen at queen at bottlehead dot com and she will take care of you.


----------



## Solarium

Any recommendations to reputable head-fi'ers who can assemble the crack + speedball for me? Can they also paint it another color?


----------



## Loquah

solarium said:


> Any recommendations to reputable head-fi'ers who can assemble the crack + speedball for me? Can they also paint it another color?


 
  
 Do you have the kit already? Bottlehead have the contact details for a recommended builder on their site (a reference to an external person, not an in-house service) so that might be an option


----------



## JamieMcC

Given the number of Cracks that went on the recent MD promotion I am surprised there have not been a few more new posts here.


----------



## grausch

jamiemcc said:


> Given the number of Cracks that went on the recent MD promotion I am surprised there have not been a few more new posts here.


 
  
 Well, I have been enjoying mine...
	

	
	
		
		

		
			




  
 It was a lot easier building the Crack than I anticipated, and it is very, very good with my 250 Ohm version of the DT 770s.
  
http://i.imgur.com/NofKLkn.jpg[/IMG]]http://
	

  
 Trying to link to imgur for the picture, but as can be seen it is not working. Anybody know how to solve this? Link Type is URL and protocol is http://


----------



## mcandmar

Just put "i.imgur.com/NofKLkn.jpg" for the URL without the HTTP part.


----------



## grausch

mcandmar said:


> Just put "i.imgur.com/NofKLkn.jpg" for the URL without the HTTP part.


 
  
 Thanks for the help. I have tried any number of ways to my previous post using your advice, but have had no luck. I guess I'll be satisfied with having my Crack in the your quote for now.


----------



## Loquah

Looks nice. Is the base varnished or polished?


----------



## grausch

loquah said:


> Looks nice. Is the base varnished or polished?


 
 I believe it is a varnish, although the description states it to be a wood stain. http://www.biopin.com/wohnraumlasur.html for the description in English. It uses linseed oil and wood oil, so I assume this would make it a varnish. However, first time I did something like this, so don't take my word on it.
  
 The Blumenstein Chocolate Orcas were the inspiration, and after unsuccessfully trying to import Tried & True varnish to Europe, I found a German company that makes an all-natural stain / varnish.
  
 The colour turned out quite well, although I believe I could improve future bases. Sanded initially with a 120 grit and then I used a brush to apply a pretty thick layer, did not wipe off any excess and just let it dry. I would then rotate between the sides doing a long and a short side per day. Between each coat, I would sand using 240 grit, but I just gave it a quick once over. Applied 5 coats in total, and the last coat was lightly ?brushed? with steel wool. However, I did not really see it making a difference initially, so stopped the process as I did not want to be in a position where I needed to apply another coat. On closer inspection, there are definite brush-marks on the base, but you need to look pretty closely to see them.
  
 I will be ordering a Quickie and Quicksand today, and would like to improve the finishing of the 2 new bases. Thus, I have some questions which I would appreciate if someone could answer:
  
 1. Will wiping any excess with paper towel get rid of the brush-marks? Is it necessary do this at the initial stages as well? I like the dark brown, and I could be mistaken, but will wiping off the excess lead to a lighter stain?
  
 2. Will applying multiple coats lead to a darker stain? I did not see much of a difference in colour after the first stain, but this could be because of the thickness of the initial coat.
  
 3. I have now found 480 grit sandpaper, but initially the finest was 240 grit. I notice that there is sandpaper for metal that goes up to 1000 grit. Will I be able to use that to get a smoother finish or won't it work with wood?
  
 4. I used a hand-sander for the job. Would it be recommended to use an electric sander between coats, or will it remove too much of the applied stain?
  
 I know these seem like some pretty ignorant questions, but before working with this base, my only experience with woodworking was making fire.


----------



## Loquah

grausch said:


> I believe it is a varnish, although the description states it to be a wood stain. http://www.biopin.com/wohnraumlasur.html for the description in English. It uses linseed oil and wood oil, so I assume this would make it a varnish. However, first time I did something like this, so don't take my word on it.
> 
> The Blumenstein Chocolate Orcas were the inspiration, and after unsuccessfully trying to import Tried & True varnish to Europe, I found a German company that makes an all-natural stain / varnish.
> 
> ...


 
  
 By the way, it sounds like it's a wood oil / polish and stain in one product.


----------



## grausch

loquah said:


> By the way, it sounds like it's a wood oil / polish and stain in one product.


 
 Thank you for the detailed reply.
  
 With the hand sander I used, the only efficient option was to sand in the direction of the grain. So I guess I was lucky. Sanding against the grain would just be completely inefficient. Thanks for the comment though, as the 480 grit is with an orbital sander and you have saved me from wasting money and time on trying to remove swirl marks.


----------



## JamieMcC

Its ok to use the sander just remember to finish off by giving it a hand sand in the direction of the grain.
  
 If you are building up any thickness with your coats then I would consider it a varnish even if it is not in the true sense you still will need to treat it like one to get good results. Stain based products tend to be very thin in nature think anything  between water and olive oil. A varnish would normally be thicker and it would be normal practise to thin it down for the first few coats decreasing the ratio of thinner on following coats. I tend to go for a oil based varnish and then use Tung oil to thin it down as required wiping on the first thin coats and then going to brush once the mix is thick enough for the brush to hold.


----------



## grausch

jamiemcc said:


> Its ok to use the sander just remember to finish off by giving it a hand sand in the direction of the grain.
> 
> If you are building up any thickness with your coats then I would consider it a varnish even if it is not in the true sense you still will need to treat it like one to get good results. Stain based products tend to be very thin in nature think anything  between water and olive oil. A varnish would normally be thicker and it would be normal practise to thin it down for the first few coats decreasing the ratio of thinner on following coats. I tend to go for a oil based varnish and then use Tung oil to thin it down as required wiping on the first thin coats and then going to brush once the mix is thick enough for the brush to hold.


 
 Ok. I will most probably just use the hand sander. In all honesty, the sanding was not really that time consuming. I thought that sanding with an electric sander would give a smoother result, but it is most likely that I applied my coats too thick. If I apply thinner coats, and wipe off the excess, I think it will solve most of my problems. But it is good to know that the final coat is the one that needs to go in the direction of the grain.
  
 Regarding the thinning of the coats, what is the rationale behind starting off with a very thin coat and then using less thinner for the later coats? I just used the varnish as it was although I made sure it was properly stirred before each application.


----------



## JamieMcC

grausch said:


> Ok. I will most probably just use the hand sander. In all honesty, the sanding was not really that time consuming. I thought that sanding with an electric sander would give a smoother result, but it is most likely that I applied my coats too thick. If I apply thinner coats, and wipe off the excess, I think it will solve most of my problems. But it is good to know that the final coat is the one that needs to go in the direction of the grain.
> 
> Regarding the thinning of the coats, what is the rationale behind starting off with a very thin coat and then using less thinner for the later coats? I just used the varnish as it was although I made sure it was properly stirred before each application.


 
  
 A thinned down mix will penetrate into the wood more that's why stains and wood preservers are typical thin so the stain and fungicides penetrate into the wood giving better protection and more even staining.
  
 With the thinned down varnish it does the same penetrates deeper sealing the wood rather than just sitting on top this also helps subsequent coats adhere better so they don't flake off later. A good majority of the wipe on oils will contain a varnish type additive its actually quit hard to find a pure oil one off the shelf in a hardware store. But if both varnish, stain or wipe on oil finish are all oil the same ie oil based they can normally be interblended testing but always do a test sample to confirm.
  
 The old school way would be to cut the varnish say with 75% oil thinners for the first couple of wipe on coats (dries very quickly)  then a 50/50 then 50/75 for building up coats and depending on how well 100% varnish flows out a coat at 100% to finish off. This sounds like a lot of fluffing around but really you are only using one pot starting out with a thin mix and just adding a little more varnish each time to the pot to increase your varnish to oil/thinner ratio.
  
 A good varnish brush with nature bristles can be quiet expensive and is normally lovingly cherished and kept stored suspended in linseed oil and can last a long time with the right care. For small jobs like the enclosures the inexpensive disposable foam brushes are the way to go for a brushstroke free finish.  If you want to speed up the process wipe on the first coats this will help bring out the colour and figuring of the wood sand with 240/320 in between then use a automotive clear coat in rattle can spraying light coats every 5-10 minutes  one of the nice things with the automotive clear is that its hard enough to compounded and polish if required for a wet look high gloss finish.


----------



## grausch

jamiemcc said:


> A thinned down mix will penetrate into the wood more that's why stains and wood preservers are typical thin so the stain and fungicides penetrate into the wood giving better protection and more even staining.
> 
> With the thinned down varnish it does the same penetrates deeper sealing the wood rather than just sitting on top this also helps subsequent coats adhere better so they don't flake off later. A good majority of the wipe on oils will contain a varnish type additive its actually quit hard to find a pure oil one off the shelf in a hardware store. But if both varnish, stain or wipe on oil finish are all oil the same ie oil based they can normally be interblended testing but always do a test sample to confirm.
> 
> ...


 
 Wow, I am learning quite a bit more on this DIY journey than I expected. I will take your advice, and since it already has linseed oil try and find some pure oil, and then apply the increasingly thicker coats. Will still need to think about the clear coat as I really like the plain wood (chocolate orcas were the inspiration after all).
  
 Now just to order the items a little later today and then for the wait...


----------



## JamieMcC

One of the easiest and quickest ways to finish wood products which is used a lot commercially (time spent finishing is lost profit) for interior products is to use a couple of coats of sanding sealer this dries in minutes and is followed by a brush on wax and a buff up, for a Crack enclosure you would be all done in minutes. But its not half as much fun and if your building for yourself its nice to take the pleasure and satisfaction in getting the type of finish you want.


----------



## Vitalstatistix

I finished my build of the Crack tonight and I'm impressed by the sound quality without the Speedball upgrade. 
I've got 2 questions:

(1) there's a background hiss/hum that's audible when between tracks. It doesn't change in loudness with the volume pot. It comes on a few seconds after the amp is switched on (presumably as the tubes warm up). Is this tube hum? Or something the Speedball can fix (I read that it has a black background).
(2) when removing the 4 resistors from the Crack in order to fit the Speedball, do I just snip the ends off or do I have to desolder the joints and then remove the resistors?


----------



## grausch

vitalstatistix said:


> I finished my build of the Crack tonight and I'm impressed by the sound quality without the Speedball upgrade.
> I've got 2 questions:
> 
> (1) there's a background hiss/hum that's audible when between tracks. It doesn't change in loudness with the volume pot. It comes on a few seconds after the amp is switched on (presumably as the tubes warm up). Is this tube hum? Or something the Speedball can fix (I read that it has a black background).
> (2) when removing the 4 resistors from the Crack in order to fit the Speedball, do I just snip the ends off or do I have to desolder the joints and then remove the resistors?


 
 Once the bottlehead forum is back up, check the Crack sub-forum. Can't recall the exact parts, but there was a problem with a sample of some of the parts received. Once swapped out, it should be dead-quiet.
  
 If I recall correctly, there is also some discussion about it on this thread.
  
 Edit: Misread your post. That was on the Speedball upgrade. Without it, it could be a number of other issues.
  
 2nd Edit: I see you posted on the Bottlehead forum as well. That is the best place to ask.


----------



## Keithpgdrb

Also could be the tube. Probably the big one. Two from bottlehead had a hum for me. Allow the amp to run for a while. Sometimes tubes just need to be worked in a bit. O noisy tube often becomes silent with time on it


----------



## RonO

> >>>(2) when removing the 4 resistors from the Crack in order to fit the Speedball, do I just snip the ends off or do I have to desolder the joints and then remove the resistors?


 
 After snipping, I ended up desoldering and removing the snipped off ends.  You'll end up going back to these terminals to solder in the power to the speedball, and you want that "junk" out of the way.


----------



## JamieMcC

Hi all just listed my Crack in the classifieds as have started building my Bottlehead Sex now if anyone is interested or knows someone who might be its been a super match for my HD650's and Beyer T1
  

  
  
http://www.head-fi.org/t/732374/bottle-head-crack-240v-custom-build
  
 Cheers
  
 Jamie


----------



## Loquah

NOOOOOO!!!!


----------



## Kyno

Hey guys and girls,
  
 I'm currently running an HD-650 on an Asus Essence ST, but will be receiving a Bottlehead + Crackhead in a few weeks. I was wondering selling the Asus and buy an external DAC would be worth it, then I read this on Bottlehead forums:
  
_I just wanted to add my kudos to Headfonia for doing God's work in pointing folks to great and affordable audio.  After spending significant time and coin on upgrading my Crack (see my posts) I was still frustrated with the tonal range and fidelity.  Putting her aside for (far too many) many months, I happened upon Headfonia's recommendation of the Topping D20 DAC and made the $129 plunge +39 for a decent Elpac converter.  Long story short, this DAC (via TOSLink from my PC) is the **** and the Crack is a now totally different animal - everything I was looking for in spades.  Thanks for the heads up Headfonia - you rock.   _
  
 Do you concur? Any other suggestions for DACs under $200?
  
 Thanks!


----------



## atraf

kyno said:


> Hey guys and girls,
> 
> I'm currently running an HD-650 on an Asus Essence ST, but will be receiving a Bottlehead + Crackhead in a few weeks. I was wondering selling the Asus and buy an external DAC would be worth it, then I read this on Bottlehead forums:
> 
> ...


 
 All I can say is that I was in the same place that the guy you quoted was, maybe not that disappointed but something was definitely missing especially in the low range, anyway I just received my Schiit Modi and the difference is freaking amazing, I can especially feel the difference when I am listening to electronic music, a genre which I like most but felt the crack is lacking in that point. 
 Never thought a DAC will affect my setup so much.
 Recommended DAC under 200$ are the ODAC and Schiit Modi.
  
 If i were you I guess I would just take one step at a time, build the Crack, connect it to the Essence ST and decide for you self if you like it or not..


----------



## adamaley

You can take the patient route and do what atraf suggested, it is a smart option. However, no one said visiting this site was supposed to lead to smart decisions in life. 
	

	
	
		
		

		
			





 I would buy an affordable DAC to start with, if anything, to be able to do a comparison between it and the Essence soundcard you already have. IMHO, the Crack + Speedball and the HD-650 respectively punch above their price points to just before ~650.00 mark of their competition. You will still make some gains beyond your 200.00 budget, since,at that price point, you DAC will still be the weakest link. I will suggest a Modi or ODAC within your budget, however if you can stretch your budget higher, the rest of your gear will still scale up with it. All the best.


----------



## Kyno

Thanks for the inputs!
  
 I will definitely try it first with my Asus Essence ST. Good thing is that a Modi or an ODAC isn't going to break the bank and can be tested fairly easily, on top of being easy to find on sale.
  
 In any case, the SB + Crack should already bring some improvements.


----------



## trentrosa

adamaley said:


> You can take the patient route and do what atraf suggested, it is a smart option. However, no one said visiting this site was supposed to lead to smart decisions in life.
> 
> 
> 
> ...


 
 I agree. A Modi or ODAC would be a nice upgrade but keep in mind your gear is capable of revealing the qualities in DACs beyond the price range of either of those options. However it is nice to make small jumps, big ones lead to even bigger ones and poof there goes your money.


----------



## Klots

How does an Audiolab M-Dac compare to Modi? 
	

	
	
		
		

		
		
	


	




 I can get M-Dac with 890$. That seems a good price, because when I googled around, the best price I found outside the country where I live was 990$ (+ 25usd shipping). Im going to listen that dac today with my Crack + HD700 at the local shop, hope it is a nice one. Too bad my TS/Chatham 5998 tube has not arrived yet.


----------



## liamstrain

For what it is worth - Once the input voltages were matched, I heard no audible differences between the M-dac, Benchmark dac 1, MD11, Yulong D100, AMB Gamma 1, and ODAC. I'd go with whichever gives you the features you need (sample rates/dsd/inputs/outputs) and not worry too much about what they sound like.


----------



## atsq17

As far as the Crack is concerned, the Modi does a good job on a budget. I preferred it to the ODAC but that's just a matter of opinion. 
  
 When upgrading to an Audio GD NFB2 (Wolfson based) there was a clear increase in technicalities (details, soundstage, etc). It was in another class.
  
 Another clear upgrade was noticed going to the Audio GD DAC-19 (PCM1704UK). I'd imagine the recently updated NFB3 (now based on Sabre 9018) with the constantly updated USB32 would provide excellent value as well. 
  
 For that money the Bifrost Uber with USB 2nd Gen is a decent value option too although I think you get more for your money in terms of audio out of the Audio GD.


----------



## grausch

jamiemcc said:


> http://www.head-fi.org/t/732374/bottle-head-crack-240v-custom-build
> 
> Cheers
> 
> Jamie


 
 Wow, I never thought you would be selling that beauty. Can't buy it unfortunately, but do you have a gallery on the Bottlehead Forum for it? It would be great if you could link to that so that I can reference to it in future. Hope you don't mind, but there are some build ideas I plan on copying.


----------



## adamaley

grausch said:


> Wow, I never thought you would be selling that beauty. Can't buy it unfortunately, but do you have a gallery on the Bottlehead Forum for it? It would be great if you could link to that so that I can reference to it in future. Hope you don't mind, but there are some build ideas I plan on copying.


 
 It is one of the more unique and signature Cracks out there. I've always been impressed with it, and admired from afar. I can only pretend to think I can imagine what you have in store for your SEX amp.


----------



## JamieMcC

grausch said:


> Wow, I never thought you would be selling that beauty. Can't buy it unfortunately, but do you have a gallery on the Bottlehead Forum for it? It would be great if you could link to that so that I can reference to it in future. Hope you don't mind, but there are some build ideas I plan on copying.


 

 Hi to be honest I never thought I would sell my Cack either and its certainly not due its performance which I find simply intoxicating its more I have been bitten by the DIY bug and a recent promotion on Bottleheads Sex amp means I can enjoy the build experience all over again. While the new Sex will be primarily used for my headphones I'm also planning on building a set of speakers to try with it and have already found have some Fostex FX120 full range driver units to build some cabinets around.
  
 Feel free to copy away I drew plenty of inspiration myself from others. For the most part I have only been standing on the shoulders of those knowledgeable giants of diy on the bottlehead forum and I cant give enough credit to all the guys who have contributed their hard won knowledge and helped point me in the right direction many times over.
  
 Here is the link to some of my build pics and Crack modding distractions.
  
http://bottlehead.com/smf/index.php?topic=5284.msg50963#msg50963


----------



## grausch

jamiemcc said:


> Hi to be honest I never thought I would sell my Cack either and its certainly not due its performance which I find simply intoxicating its more I have been bitten by the DIY bug and a recent promotion on Bottleheads Sex amp means I can enjoy the build experience all over again. While the new Sex will be primarily used for my headphones I'm also planning on building a set of speakers to try with it and have already found have some Fostex FX120 full range driver units to build some cabinets around.
> 
> Feel free to copy away I drew plenty of inspiration myself from others. For the most part I have only been standing on the shoulders of those knowledgeable giants of diy on the bottlehead forum and I cant give enough credit to all the guys who have contributed their hard won knowledge and helped point me in the right direction many times over.
> 
> ...


 
 Thank you. I am using a lot of other builds for inspiration as well. I like the way you documented all the different mods as it gives a nice baseline on how to build.
  
 My Crack is currently still stock and I am yet undecided on whether to buy a new Crack and Speedball so that I can compare it to the old one, or just mod away on my current build.
  
 I also used the recent 10% discount at Bottlehead. Was going to get a Q&Q combo, but realised that after adding in the PJCCS and bases, that the cost was close to the SEX. After adding in the C4S and impedance switch I realised I was pretty close to the price of a Stereomour. So hopefully the Stereomour & Impedance Switch does not take too long to ship 
	

	
	
		
		

		
		
	


	




 (looks like it will take about 6 weeks). Good thing a Paramount and BeePree combo is a significant step up, otherwise my credit card would have rolled over and died.
  
 Funny thing, with my Crack I was pretty patient. I ordered the Stereomour on Tuesday and must have checked the Shipping Status page at least twenty times since then.


----------



## JamieMcC

loquah said:


> NOOOOOO!!!!


 

 YESSSS!!! lol and at just about the costs of the parts! Not including the custom case or carbon fibre work (my day job) you really don't want to know how much proper carbon stuff costs to do its just hideously expensive.
  
 A custom one off piece like the Cracks top plate out of the same materials if building from scratch with labour would cost about the same as what I'm asking for the whole Crack!!! Just lucky I have a few pieces left over from previous jobs.


----------



## adamaley

jamiemcc said:


> YESSSS!!! lol and at just about the costs of the parts! Not including the custom case or carbon fibre work (my day job) you really don't want to know how much proper carbon stuff costs to do its just hideously expensive.
> 
> A custom one off piece like the Cracks top plate out of the same materials if building from scratch with labour would cost about the same as what I'm asking for the whole Crack!!! Just lucky I have a few pieces left over from previous jobs.


 
 Lol. Being into recreational cycling, I can hazard a guess as to how costly that top plate is. Whoever purchases this is getting a steal regardless.


----------



## Dimitris

Same here. I am actually buying stuff to make up for hard times coming up. My daughter is 7 days old.


----------



## trentrosa

dimitris said:


> Same here. I am actually buying stuff to make up for hard times coming up. My daughter is 7 days old.




Congratulations on the young one! Future audiophile?


----------



## Dimitris

Thank you. Hopefully. My son seems to enjoy speakers more so far


----------



## mcandmar

dimitris said:


> Thank you. Hopefully. My son seems to enjoy speakers more so far


 
  
 Kids + Speakers =


----------



## dsound

mcandmar said:


> Kids + Speakers =


 
 +1  I am on my 2nd Fostex driver replacement thanks to kids (not my own) curious fingers.
  
 Thankfully my kids know not to touch the Crack amp, that would be a painful lesson if they touched the tubes.


----------



## kothganesh

dsound said:


> +1  I am on my 2nd Fostex driver replacement thanks to kids (not my own) curious fingers.
> 
> Thankfully my kids know not to touch the Crack amp, that would be a painful lesson if they touched the tubes.


 
 Hopefully its out of reach


----------



## Barry S

Finally started work on my Crack. First order of business--enlarge the potentiometer shaft hole to accept a stepped attenuator. Then some sanding of the chassis plate and transformer bell, and painting with dark bronze hammertone paint.


----------



## GrindingThud

Awesome! Hope to hear it at the next meet..... 
Are you planning a speedball install too?


barry s said:


> Finally started work on my Crack. First order of business--enlarge the potentiometer shaft hole to accept a stepped attenuator. Then some sanding of the chassis plate and transformer bell, and painting with dark bronze hammertone paint.


----------



## Barry S

grindingthud said:


> Awesome! Hope to hear it at the next meet.....
> Are you planning a speedball install too?




Definitely planning on having at the next meet. Thanks for reminding me--I need to reserve the library tonight for a date in November. Installing a Speedball is in my plans, it'll definitely be in by November. Still very tempted by that KSA-5 mini kit, but I want to finish the Crack first.


----------



## GrindingThud

Cool, can't wait to hear it. I may also have a Dynalo Mk2 in the works for then....


----------



## stupidmop

Finished her a few weeks ago. Gonna re-do the base, I went too dark. Sounds AMAZING.


----------



## i luvmusic 2

stupidmop said:


> Finished her a few weeks ago. Gonna re-do the base, I went too dark. Sounds AMAZING.


 
 Actually it looks good!My base is still unfinished can't decide what to do with it.


----------



## diaBoliQu3

My base worst.  Likely will get a new wood to re-build again.


----------



## JamieMcC

diaboliqu3 said:


> My base worst.  Likely will get a new wood to re-build again.


 

 Just sand it down and re do the finish or another option is vinyl wrap it here's a couple of wrap jobs the Flag on the top plate and Carbon wrap on a Crack enclosure


----------



## stupidmop

Figured I better show what's under the hood. Totally stock, for now. Don't think I'm gonna get speedball, heard tubes don't make as much diff with it but dunno

  

 And a better look at the paint


----------



## trentrosa

stupidmop said:


> Figured I better show what's under the hood. Totally stock, for now. Don't think I'm gonna get speedball, heard tubes don't make as much diff with it but dunno
> 
> 
> 
> And a better look at the paint


 
 Speedball brings the performance of the Crack up substantially. Clarity is optimized and the bass tightens up very nicely.


----------



## liamstrain

stupidmop said:


> Figured I better show what's under the hood. Totally stock, for now. Don't think I'm gonna get speedball, heard tubes don't make as much diff with it but dunno
> 
> 
> 
> And a better look at the paint


 
  
 Having heard both versions, with varying tubes, I decided to use a non-speedballed Crack for my own listening as well. It was not a significant difference with my headphones (Senn HD600s) - and I preferred the additional harmonics in the regular crack. Not everyone will agree, but that was my call.


----------



## Nympho

How much of a difference is there between the DT 990 PRO 250 and 600 on crack with speedball? As I already own the 250ohm only because I already had a magni and I am thinking about getting the crack with speedball.


----------



## Armaegis

If you already have the 250ohm version, I wouldn't bother with the 600. If you like the Beyer sound though, you could try the DT880/600 instead.


----------



## diaBoliQu3

jamiemcc said:


> Just sand it down and re do the finish or another option is vinyl wrap it here's a couple of wrap jobs the Flag on the top plate and Carbon wrap on a Crack enclosure


 
 Duh, show off aren't you mate? I envy you. Argh! Nice job you have there. BTW, the carbon finished is it carbon sticker? The thing is ****s happened as below:

 1. Base perfectly built. Few month later, the glue fall off it self.
 2. Reglue the only part that needed. Still got a little gap but I don't mind.
 3. The base fall off from 6 meters height. Luckily only the glue separated. Along with small chip off.
 4. Reglue all 4 corner together. Only one corner got perfect attach. Screw you...
 5. Sanding done, only painting left. Painting is almost done, then there's emergency case need my attention during public holiday. I left the base 90% finished.
 6. Turn out it's gastritis post hangover case but the guy told me he drank coffee and suspect his friend put poison inside his drink. Facepalm.
 7. Went back home and there the base lying, unfinished. I removed again the varnish with thinner. Sigh.
 8. I don't have mood to finish the project. Luckily I got my hifi to listen.


----------



## kothganesh

diaboliqu3 said:


> Duh, show off aren't you mate? I envy you. Argh! Nice job you have there. BTW, the carbon finished is it carbon sticker? The thing is ****s happened as below:
> 
> 1. Base perfectly built. Few month later, the glue fall off it self.
> 2. Reglue the only part that needed. Still got a little gap but I don't mind.
> ...


 
 OMG. I feel for you. Especially 6.


----------



## mullardpassion

liamstrain said:


> Having heard both versions, with varying tubes, I decided to use a non-speedballed Crack for my own listening as well. It was not a significant difference with my headphones (Senn HD600s) - and I preferred the additional harmonics in the regular crack. Not everyone will agree, but that was my call.


 

 I agree with you..Its just a matter of personal taste and nice build btw


----------



## cmander10

What is a good pair of tubes for psychedelic/blues rock, classical, jazz, and the likes. I have an HD600 and will have SB soon. About $90 to spend for both preamp and a curved power tube.


----------



## Loquah

cmander10 said:


> What is a good pair of tubes for psychedelic/blues rock, classical, jazz, and the likes. I have an HD600 and will have SB soon. About $90 to spend for both preamp and a curved power tube.


 
  
 Depends on what you're looking for in those genres. How do you like the sound now with the stock tubes? What would you like more / less of?


----------



## cmander10

loquah said:


> Depends on what you're looking for in those genres. How do you like the sound now with the stock tubes? What would you like more / less of?


 
 I have a Raytheon power and RCA preamp. I like the bass on these, so either equal or more is good. Looking for a rich/smooth sound with nice soundstage/imaging (3D). A quiet background is important too. Getting the most natural sound is my main goal. That's why I chose the HD600 over the DT880.
  
 I have to get my RCA tube replaced by Bottlehead since it is defective and has a noticeable white noise and messing up the voltages. Can't really say if I want more or less of anything since I don't have anything to compare to and this is my first tube amp.


----------



## Loquah

cmander10 said:


> I have a Raytheon power and RCA preamp. I like the bass on these, so either equal or more is good. Looking for a rich/smooth sound with nice soundstage/imaging (3D). A quiet background is important too. Getting the most natural sound is my main goal. That's why I chose the HD600 over the DT880.
> 
> I have to get my RCA tube replaced by Bottlehead since it is defective and has a noticeable white noise and messing up the voltages. Can't really say if I want more or less of anything since I don't have anything to compare to and this is my first tube amp.


 
  
 See if you can pick up a set of Mullard tubes - I really liked their spacious presentation and smooth overall sound. You may find that you like the Mullard power tube with an RCA cleartop up front for extra sparkle, but the Mullards are cheap enough generally to be worth a punt.


----------



## cmander10

loquah said:


> See if you can pick up a set of Mullard tubes - I really liked their spacious presentation and smooth overall sound. You may find that you like the Mullard power tube with an RCA cleartop up front for extra sparkle, but the Mullards are cheap enough generally to be worth a punt.


 
 Can't seem to find any Mullard power tubes that will fit the Crack. Should it be 6AS7G?


----------



## Loquah

cmander10 said:


> Can't seem to find any Mullard power tubes that will fit the Crack. Should it be 6AS7G?


 
  
 No, 6080 variants - they may have a WB or WA after the 6080. I can't remember which one I had, but it's probably mentioned in the Bottlehead Discussion and Comparison thread


----------



## listen4joy

i have solder wire 63/37 0.6 mm is it good for the job?


----------



## cmander10

I didn't know the name before so I said curved tube, but what it is called is an ST shape power tube. I'm looking at Amperex Buggle Boy or 7119 for the input since they seem to be around $35, which is great. Are there any suggestions as far as pairing the power and input. Should they be similar in sound or opposite?


----------



## Loquah

cmander10 said:


> I didn't know the name before so I said curved tube, but what it is called is an ST shape power tube. I'm looking at Amperex Buggle Boy or 7119 for the input since they seem to be around $35, which is great. Are there any suggestions as far as pairing the power and input. Should they be similar in sound or opposite?


 
  
 Can't answer about good pairings with those models, but as for having same sound or opposite it all depends on you. For example, my old Mullard + Mullard combo was too warm for my tastes and headphones (HD650) so I used a cleartop RCA 12AU7 to offset the Mullard 6080. If I'd been using something brighter like DT990s though I might have loved the Mullards together though so it's all about synergies and preferences.


----------



## JamieMcC

cmander10 said:


> I didn't know the name before so I said curved tube, but what it is called is an ST shape power tube. I'm looking at Amperex Buggle Boy or 7119 for the input since they seem to be around $35, which is great. Are there any suggestions as far as pairing the power and input. Should they be similar in sound or opposite?


 
  
 Generally you will be looking to choose a combination of tubes that have good synergy both with your headphones and with the genre of music you will be listening to.
  
 12au7 rca clear top for example is a great choice if you are listening with the Senn HD650's as the clear top has a quiet a bright treble signature to it which complement the slightly darker top end of the Senn 650's.
  
 If your using different cans like some of the beyers which all ready have a clean top end then using the clear top tube they might/will sound overly bright. So not such a good pairing with music that has a more top end focus brass percussion, female soprano, choral music as they might sound a little to fatiguing.


----------



## kothganesh

jamiemcc said:


> Generally you will be looking to choose a combination of tubes that have good synergy both with your headphones and with the genre of music you will be listening to.
> 
> 12au7 rca clear top for example is a great choice if you are listening with the Senn HD650's as the clear top has a quiet a bright treble signature to it which complement the slightly darker top end of the Senn 650's.
> 
> If your using different cans like some of the beyers which all ready have a clean top end then using the clear top tube they might/will sound overly bright. So not such a good pairing with music that has a more top end focus brass percussion, female soprano, choral music as they might sound a little to fatiguing.



Jamie, what tube do you recommend for the HD 800? Thanks


----------



## cmander10

I'm thinking 12AU7 Amperex Bugle Boy or RCA Cleartop.
  
 The only good ST power tubes I could find are the 5998 Tung-Sol and the 6AS7G Tung-Sol or RCA. Anyone ever paired one of these with Bugle or Cleartop? If not, any suggestion as to which power would pair best for rich/warm natural sound with good bass. Listening to psyc/blues rock, classical, jazz.
  
 Also, looking into the Mullard 6080 since it seems to fit my needs despite it being a straight tube.


----------



## JamieMcC

kothganesh said:


> Jamie, what tube do you recommend for the HD 800? Thanks


 
  
 The HD800 would defiantly benefit from using premium tubes as they can bring whole extra dimension to the presentation that the HD800's have the ability to reveal. Tubes like the Tung-sol 5998, GEC brown base and WE421a  would be top of the list. I would suggest you consider switching to the E80cc for you input tube and consider the switchable resistor mod on the bottlehead forum to operate it at a optimum voltage. its a great inexpensive mod only costing a couple bucks.
  
 If your Crack is stock then consider looking at some of the popular mods for it with the HD800s the difference is going to be quiet noticeable.
 Film output caps, stepped attenuator at a minimum these will help you get the best out of the premium tubes. 
  
 If you have not seen it Nick Tams multi 6080 6as7g review its a excellent post on the merits of the different driver tubes available the original full review was corrupted when Bottlehead changed servers but can still be found here. I find his evaluation of the tubes to be very accurate.
  
http://the-key.enix.org/~krystal/review-tube-bottlehead.html
  
  


cmander10 said:


> The only good ST power tubes I could find are the 5998 Tung-Sol and the 6AS7G Tung-Sol or RCA. Anyone ever paired one of these with Bugle or Cleartop? If not, any suggestion as to which power would pair best for rich/warm natural sound with good bass. Listening to psyc/blues rock, classical, jazz.
> 
> Also, looking into the Mullard 6080 since it seems to fit my needs despite it being a straight tube.


 
  
 The Mullard 6080 and GEC 6080 are very nice sounding tubes
  
 If anyone is on a tight budget then don't over look the Svetlana Winged "C" 6H13C its inexpensive and a new tested ones can be found for around $10 on ebay they offer excellent value and are on par with the more well known American brands.


----------



## liamstrain

jamiemcc said:


> If your Crack is stock then consider looking at some of the popular mods for it with the HD800s the difference is going to be quiet noticeable.
> Film output caps, stepped attenuator at a minimum these will help you get the best out of the premium tubes.


 
  
 FWIW - this has not been my experience. Tubes have made some minor subjective differences, but the only time output caps did was when they were mis-specced, not doing their job properly. (e.g. not an improvement in sound). No audible difference with stepped attenuators. 
  
 I am running a vintage duMont 12AU7A, and RCA silver top/black base 6AS7G - those perform nicely without obvious distortions to the sound regardless of headphone paired (and yes, that includes the Senn 800)
  
  
 If you want different sound, spend your money on different headphones, or a parametric eq, not mods to your amp.


----------



## bigfatpaulie

liamstrain said:


> FWIW - this has not been my experience. Tubes have made some minor subjective differences, but the only time output caps did was when they were mis-specced, not doing their job properly. (e.g. not an improvement in sound). No audible difference with stepped attenuators.
> 
> I am running a vintage duMont 12AU7A, and RCA silver top/black base 6AS7G - those perform nicely without obvious distortions to the sound regardless of headphone paired (and yes, that includes the Senn 800)
> 
> ...


 
  
 I had very different results than you and I agree with Jamie.  Different caps and a new attenuator made a big difference for me.  I also found that difference tubes had a significant effect on the sound.  And all of those changes are far less expensive then a new pair of headphones.


----------



## cmander10

liamstrain said:


> FWIW - this has not been my experience. Tubes have made some minor subjective differences, but the only time output caps did was when they were mis-specced, not doing their job properly. (e.g. not an improvement in sound). No audible difference with stepped attenuators.
> 
> I am running a vintage duMont 12AU7A, and RCA silver top/black base 6AS7G - those perform nicely without obvious distortions to the sound regardless of headphone paired (and yes, that includes the Senn 800)
> 
> ...


 
 Have you tried the Tung-Sol 5998? I'm trying to decide between that and the RCA 6AS7G.


----------



## olegausany

TungSol / Chatham 5998 should be on everybody's short list


----------



## cmander10

If you had to pick the better of the two, would you pick vintage or 1962.


----------



## mcandmar

The vintage one is better balanced at 2110/2010 vs 2100/2575 for the 1962 one.  I would pick the vintage.


----------



## Klots

Have you looked the CBS 5814A? Also very nice tube and I read that it pairs with 5998 very well. Im using that tube with my GE 6as7ga at the moment, but my 5998 should arrive next week.


----------



## cmander10

klots said:


> Have you looked the CBS 5814A? Also very nice tube and I read that it pairs with 5998 very well. Im using that tube with my GE 6as7ga at the moment, but my 5998 should arrive next week.


 
 Have to try it another time along with E80CC. Already bought the Bugle Boy and Cleartop. Leaning towards the RCA 6AS7G as well since the only Tung sol 5998 I can find is on vacuumtubes.net for $85.


----------



## Klots

cmander10 said:


> Have to try it another time along with E80CC. Already bought the Bugle Boy and Cleartop. Leaning towards the RCA 6AS7G as well since the only Tung sol 5998 I can find is on vacuumtubes.net for $85.


 
 I got my 5998 for 75$+10$ shipping to europe (http://www.ebay.com/itm/321501241195). He had 6 tubes + 6 pairs of 5998 for sale, and they went out fast. But some crazy italian is selling one for 194 usd


----------



## olegausany

cmander10 said:


> klots said:
> 
> 
> > Have you looked the CBS 5814A? Also very nice tube and I read that it pairs with 5998 very well. Im using that tube with my GE 6as7ga at the moment, but my 5998 should arrive next week.
> ...



You can't find them cheaper


----------



## kothganesh

I bought the TS 5998 for $75 about a month ago


----------



## JamieMcC

vacuumtubes.net by all accounts are quiet good with exchanging if you luck out and get a noisy tube even when a tube tests well this doesn't guarantee its going to be quiet enough to be suitable for head amp use.


----------



## trentrosa

cmander10 said:


> Have to try it another time along with E80CC. Already bought the Bugle Boy and Cleartop. Leaning towards the RCA 6AS7G as well since the only Tung sol 5998 I can find is on vacuumtubes.net for $85.




Vacuum tubes.net is actually sold out of the 5998 as of lately.


----------



## cmander10

If that's true then I have no options besides the 6AS7G unless there is something better out there. The only reasonably priced 5998s on ebay have crap testing results.


----------



## cmander10

Does JAN designation do anything for the tube: sturdier or higher quality parts?


----------



## olegausany

JAN means it was made to meet military spec


----------



## cmander10

olegausany said:


> JAN means it was made to meet military spec


 
 So does that mean anything other than the tube was only allowed to pass if it met their standards? No differences in build quality or sound?


----------



## cmander10

Any places to look to find a 5998 Tung Sol?


----------



## i luvmusic 2

Ebay.............
	

	
	
		
		

		
			





 
  I've just checked their's plenty of 5998 and they cost plenty of money as well.
	

	
	
		
		

		
		
	


	



 Do you really need the 5998 for the CRACK?Does this tube improved the sound quality of the CRACK that much?
 I changed the OUTPUT CAPS on my CRACK i paid $125 for 2 caps(See pictures).Does this cap improved the sound?Yes a little bit not like it's night and day diference IMO the improvement is not worth $125.I installed 23 stepped attenuator and IMO it only fixed the channel imbalanced and the attenuator it reduced the bass,is this attenuator upgrade worth it?maybe.
  If i'am going to build another CRACK i will just install the Speedball and be done with it.The CRACK's sound with the Speedball is really really good IMO no need for anymore modifications because this amp is well put together.Sorry folks!


----------



## cmander10

i luvmusic 2 said:


> Ebay.............


 
 So I guess it's a waiting game for the ebay gods to bless me.


----------



## i luvmusic 2

GOOD LUCK!


----------



## cmander10

i luvmusic 2 said:


> GOOD LUCK!


 
 I decided on the RCA 6AS7G for now. If I can find a deal on the 5998 then great, otherwise I should be happy with the RCA until I need it replaced.


----------



## i luvmusic 2

That's what i've been using on my CRACK RCA,Raytheon,Sylvania,Chatham,Tung-Sol,GE 6AS7G's/6080's,12AU7's/5963 and 6SN7's these are all my existing tubes before the CRACK.No need for me to tube roll i have plenty of these tubes i'am set for life.Tube rolling can be EXPENSIVE.I'am trying to work around all my existing tubes when ever i'am looking for an amp in this way i don't need to spend more money on tubes Except for the S.E.X. i need a few pairs of 6DN7's i'am waiting for four pairs of these tubes before the S.E.X. arrived.
   For me using a Premium/Exotic tubes on a amp that is not designed for it is kind of waste,sure it works but is it worth it?I don't know and i don't want to get into premium tubes unless i have or i can afford an AMP that is designed to run Premium tubes.Good luck on your tubes searching/rolling and i'am sorry for your wallet!


----------



## Keithpgdrb

cmander10 said:


> Any places to look to find a 5998 Tung Sol?


Best place to get that 5998 is in the for sale forums. Lots of tube guys willing to sell this tube without raping you. Never hurts to ask.


----------



## Loquah

i luvmusic 2 said:


> Ebay.............
> 
> 
> 
> ...


 
  
 Just to clarify, there are many different attenuators out there. We discussed some irregularities with the one you received (pictured) prior to the installation so I don't think it's a representative example of what's possible. I didn't notice this the first time because we were so focussed on the stereo / mono question, but if you look at the picture, the attenuator is built with some Dale resistors (plain brown with printed ratings) and various other resistors. Having used a 100% Dale resistor attenuator in my S.E.X. (and based on many other accounts from other experienced builders) I can safely say that a high quality attenuator will do a lot more than just fix channel imbalances and is probably the best bang-for-buck modification after the Speedball.
  
 I agree that capacitors are a more subtle upgrade, but with a more transparent attenuator you may find that the caps are able to exert more influence on the sound of your Crack. I built a Crack for a friend recently using the MCaps (as you've used) along with some upgraded power supply caps and a Dale stepped attenuator and the results were excellent and a noticeable improvement on the already outstanding stock sound of the Crack + Speedball.


----------



## i luvmusic 2

Pardon me for being a noob!I'am still learning about these Electronics/Diy amps.When you said TRANSPARENT does it mean less bass not forward sounding like the stock crack?These is what i've heard after i installed the Attenuator less bass the sound is more like distant and wider unless i turn the volume loud then it will sound pretty closed to the stock crack but then it's too loud to my liking.


----------



## i luvmusic 2

I do not intend to offend anyone who performed those upgrades.Pardon me!


----------



## Loquah

i luvmusic 2 said:


> Pardon me for being a noob!I'am still learning about these Electronics/Diy amps.When you said TRANSPARENT does it mean less bass not forward sounding like the stock crack?These is what i've heard after i installed the Attenuator less bass the sound is more like distant and wider unless i turn the volume loud then it will sound pretty closed to the stock crack but then it's too loud to my liking.


 
  
 My experience with the Dale attenuators I've personally used and installed for friends is that the sound gets cleaner all around. There should be no loss of any frequency response (bass, mids, or treble), but rather a cleaner sound with more sense of detail. The stock attenuator provided by Bottlehead, although fine, sounds a little smoothed over in comparison to the aftermarket ones I've tried.
  
 I think the problems you are hearing may be due to a poorly built attenuator with varying resistor brands which may mean that some positions on the dial actually sound different to others. Based on your pictures you installed an Alps pot since, did that improve things at all?
  


i luvmusic 2 said:


> I do not intend to offend anyone who performed those upgrades.Pardon me!


 

 No, that's OK - I just wanted to balance the discussion for anyone reading it because there are multiple factors to consider - your post was completely fine.


----------



## JamieMcC

i luvmusic 2 said:


> I do not intend to offend anyone who performed those upgrades.Pardon me!


 
  
 Your ok, I for one am just curious as to why you are not seeing better results for your efforts your results certainly do not seem to be the norm.
  
 Your Mundorfs are not inexpensive caps by any stretch and are actually quiet a investment. Perhaps with a bit of combined brainstorming here we can figure out what might be limiting the performance and improvements you should be experiencing as you really should be noticing much more than a subtle upgrade here with them and a attenuator over the stock electrolytic capacitors and volume pot. Would you mind posting some details on your chain and cans used it might help.
  
 I have tried a few different capacitors combinations including Solen, Mundorf, JFX, Jantzen, Hovland SuperCap, Epcos, RTI, Valab, among the more well known makes in my own Crack which is also fitted with the Valab attenuator and have always thought the Crack transparent enough to notice differences between them and having some very clear favourites amongst them.


----------



## liamstrain

jamiemcc said:


> Your ok, I for one am just curious as to why you are not seeing better results for your efforts your results certainly do not seem to be the norm.


 
  
 Debatable. There seems to be a LOT of expectation bias in the capacitor/mod world that is not backed by objective measurements. His results are consistent both with my experience, and with the data I have seen.


----------



## JamieMcC

liamstrain said:


> Debatable. There seems to be a LOT of expectation bias in the capacitor/mod world that is not backed by objective measurements. His results are consistent both with my experience, and with the data I have seen.


 
  
 I'm not rising to the bait, (well yes I am and I should know better) having personally tried dozens of combination and am in no doubt to the differences. Further I don't really see how objectivity and measuring comes into it my self. Last time I checked they still didn't know how to objectively measuring pain so I guess that must be imaginary try convincing  a couple of billon people of that. 
  
 Perhaps they just don't yet know yet how or what they are measuring relates in a auditory sense to what people hear that is if in fact they are measuring the right thing to start off with. Bearing in mind lots of capacitors are manufactured with differing techniques and materials would it not be unreasonable to think this does have a effect.
  
 Five capacitors all the same value but made with differing methods and material its just plain impossible they can objectively measure the same which is basically what the premise is about subjective perception. More like they just don't know how or what to measure.
  
 1/ Metalized film
 2/ Film and alluminium foil
 3/ Film and Tin foil,
 4 Film and Copper foil
 5/ Electrolytic   
  
 Lets not even get into the different dielectric combinations.


----------



## mcandmar

That attenuator (*i luvmusic 2*) bought is a series attenuator, as in all the resistors are joined together in a daisy chain and as you raise the volume the resistors are removed from the circuit one by one.  Its entirely possible is has no sonic benefit over a stock pot as you basically have two dozen resistors in your signal path.
  
 The ladder style attenuator (i.e. the ones that are twice as tall with four layers of resistors) switch between different sets of resistors as you change the volume, so there is only ever 2 resistors in the signal path at any given time, that's where the real sonic benefit comes from.
  
 Both styles will have equal channel balance throughout the volume range unlike a stock carbon track pot.
  
 As for the caps, the difference between stock electrolytic caps and ANY film cap is significant, i cant see how that change isn't noticeable.  ....unless of course you only listen to EDM or some other rubbish


----------



## liamstrain

jamiemcc said:


> I'm not rising to the bait, (well yes I am and I should know better) having personally tried dozens of combination and am in no doubt to the differences. Further I don't really see how objectivity and measuring comes into it my self.


 
  
 Not trying to provide "bait" - but we know a LOT about audibility and our ability to measure and compare frequency response and other acoustic traits far exceeds the human ability to perceive those differences. The biggest issue is it is hard for someone to swap new components into their amp fast enough to do true, level matched (much less blind) testing. So auditory memory and bias as the biggest factors in our subjective experience of Mods. 
  
 Which is to say, I am certain you hear differences. I just question the nature of those differences. Audible (objective) vs. Psycho-acoustic. If you are of the opinion that we cannot measure audible changes to a circuit (or that we can hear things that we cannot demonstrate via measurements) though, we probably cannot have a productive conversation. 
  
 I do not disagree that there are things that will affect the audible traits of an amplifier. But aside from using incorrect values (which would cause bass roll-off, especially with headphones on the lower level of impedence for the crack, and add distortion) - the audible change to a circuit from a capacitor (unless the circuit is designed very poorly, which the crack is not, or the capacitor chosen is unsuited for the intended use - e.g. ceramic caps), is very small indeed. On the order of "corrected by better level matching" small. 

 Anyway - this is probably best reserved for "Sound Science" - I'm mostly trying to assure those who spend the money, make the mods, then don't hear what they were hoping to hear, that it's not that they necessarily did anything wrong. Many people do NOT have audible changes from such a modification, and frankly, in the case of the Crack where the included components are well specced and placed in a well designed circuit, there is little to suggest that they would hear ANY differences in sound quality or tonal representation, much less "night and day" ones.


----------



## JamieMcC

liamstrain said:


> Not trying to provide "bait" - but we know a LOT about audibility and our ability to measure and compare frequency response and other acoustic traits far exceeds the human ability to perceive those differences. The biggest issue is it is hard for someone to swap new components into their amp fast enough to do true, level matched (much less blind) testing. So auditory memory and bias as the biggest factors in our subjective experience of Mods.
> 
> Which is to say, I am certain you hear differences. I just question the nature of those differences. Audible (objective) vs. Psycho-acoustic. If you are of the opinion that we cannot measure audible changes to a circuit (or that we can hear things that we cannot demonstrate via measurements) though, we probably cannot have a productive conversation.
> 
> ...


 
  
 lol yes the conversation is really better suited to being accompanied by a pint and a pie over a table at the local followed by some ABing of a modded and stock version it would make for a entertaining evening.


----------



## liamstrain

Yes it would indeed. ​Several pints and you might win me to your side.  

 I actually once drew up plans for a capacitor switching board, which would allow for faster testing on the same amplifier - but I never solved a few theoretical issues (like safe discharge). But it would be interesting to do both measurement and listening tests with such a set-up, as that would help minimize some variables.


----------



## grausch

liamstrain said:


> Yes it would indeed. ​Several pints and you might win me to your side.
> 
> I actually once drew up plans for a capacitor switching board, which would allow for faster testing on the same amplifier - but I never solved a few theoretical issues (like safe discharge). But it would be interesting to do both measurement and listening tests with such a set-up, as that would help minimize some variables.


 
 Safe discharge???? What is that? Does it go well with beer? Obviously you need a few more pints.
	

	
	
		
		

		
		
	


	



  
 In any case, I am still debating whether to buy another Crack just so that I can test these differences. Was thinking of running a Y-cable from the source and getting 2 sets of headphones. However, that introduces another set of problems, i.e. who says two of the exact same headphones sound the same? Also, we are assuming that all of the parts inside of both Cracks have been manufactured identically (highly unlikely) and have the same amount of burn-in. We are also assuming the tubes sound exactly the same. 
  
 Or maybe, I should just tinker with the existing Crack, enjoy the music and save up for another amp.


----------



## i luvmusic 2

jamiemcc said:


> i luvmusic 2 said:
> 
> 
> > I do not intend to offend anyone who performed those upgrades.Pardon me!
> ...


 
 Holly! JM  how many more CAPS do you need?I think you're  a CAPACITOR Hoarder.........


----------



## liamstrain

grausch said:


> Or maybe, I should just tinker with the existing Crack, enjoy the music and save up for another amp.


 
  
 Probably the best plan.


----------



## i luvmusic 2

jamiemcc said:


> i luvmusic 2 said:
> 
> 
> > I do not intend to offend anyone who performed those upgrades.Pardon me!
> ...


 
 MY setup, From ACER laptop(using Foobar, FLAC)  to USB in TEAC UD- H01S(DAC) RCA out to CRACK , CRACK to HD 650 or DT880 600 ohms.
 JVC XV-521 DVD Player(I know it's old but it does the job,i have this for over ten years now and still working) used for playing CD's to optical in TEAC (DAC) to crack,CRACK to HD 650 or DT880 600 ohms.
 CABLES used are 3ft generic USB cable,3ft optical cable and Diy RCA cable(2ft ViaBlue NF-A7 Triple Sheild,REAN Gold plated RCA Jack)
 I listened to all types of Music/Genre anything that sound good to my ears.I have about 500+ Cd's i stopped counting them long time ago i just buy and buy. 
 Your not gonna tell me to upgrade my cables are you?
	

	
	
		
		

		
		
	


	




 
  
 JVC  (Junk Very Cheap)


----------



## Barry S

I finished my Crack this evening--woohoo! It was a fun build, except for a couple spots where it was very tight getting everything in. Glad I have a very narrow pair of needle-nosed pliers. The resistances all check out; I'll do the voltage checks tomorrow. I painted the chassis plate and transformer bell with a dark bronze hammer tone finish, but I haven't decided how to finish the base.


----------



## Loquah

It looks great - nice neat work!


----------



## Doc B.

Nice work!


----------



## Barry S

Thanks!  I took my time and the manual was outstanding--it made things very easy to follow. The tubes are in and it's ready for the voltage checks tonight--hoping I don't let out any of the precious magic smoke.


----------



## JamieMcC

barry s said:


> Thanks!  I took my time and the manual was outstanding--it made things very easy to follow. The tubes are in and it's ready for the voltage checks tonight--hoping I don't let out any of the precious magic smoke.


 
 Nice neat build, fingers crossed your  voltage checks all go ok and you get to enjoy the fruits of your labour tonight.


----------



## OJNeg

liamstrain: You should get a chance to compare a cheap pair of electrolytics to even a basic pair of polyprop or film caps. The difference is not what I would consider small.
  
 Jamie: Which Jantzens have you tried? I presume your cap rolling experience is only with the Crack?


----------



## liamstrain

ojneg said:


> liamstrain: You should get a chance to compare a cheap pair of electrolytics to even a basic pair of polyprop or film caps. The difference is not what I would consider small.


 
  
 I have done so many times over the years, in many different types of amps. *In a properly designed circuit* (like the Crack's) - the difference is very small provided they are correctly specced - even against some of the most vaunted names in audiophile capacitors. And to be fair, the ones provided with the Crack kit, are not crappy caps to begin with.

 I would not be surprised to find in a level matched DBT, that it was entirely indistinguishable. But that's just my $.02. I prefer to look down other paths for my audible sound modifications. We don't need to rehash the argument here - just wanted to point out that my opinion is not based just on what the theory says, but also my personal experience.


----------



## Doc B.

I think the point here is not whether Liam hears a difference or not. The point is that he took the effort to find out if he hears a difference or not. That's what this DIY gig is all about. To each his own what the final result may be. Obviously I come from the "what matters in an audio system - everything" school, but I thoroughly respect someone who finds our stuff fine as it comes out of the box. That is what we are shooting for, to produce a product where modification might give you improvement, but it might also be right on the threshold of diminishing returns to mod it. Hopefully Liam's observations support the notion that we are close to that.


----------



## liamstrain

Thanks Doc, and sorry for the tangent. I won't bring it up outside of the "sound science" subforum again.


----------



## JamieMcC

ojneg said:


> liamstrain: You should get a chance to compare a cheap pair of electrolytics to even a basic pair of polyprop or film caps. The difference is not what I would consider small.
> 
> Jamie: Which Jantzens have you tried? I presume your cap rolling experience is only with the Crack?


 
  
 My cap rolling experimentation has been with the Crack so far and will soon extend to the Bottlehead Sex amp when I get finished putting it together.
  
 The Jantzen's were the superior Z caps
  
 Some pics and details of some of mods and combinations tried in the link
  
http://bottlehead.com/smf/index.php?topic=5284.0


----------



## OJNeg

Cool thanks


----------



## JamieMcC

I noticed this GEC 6as7g listed in the US its the brown round base version thought I would mention it as they don't come up very often these days.
  
http://www.ebay.co.uk/itm/1-Vintage-GEC-6AS7G-6080-A1834-AUDIO-TUBE-/301311577889?pt=Vintage_Electronics_R2&hash=item462791cf21


----------



## grausch

@Barry S: That is a very clean build. I like the way you cleaned up around the nine-pin for the Speedball install. After seeing your build, I am seriously considering buying another Crack just so that I can get the wiring that clean. Currently I will really struggle to install the Speedball in my Crack.


----------



## cmander10

Anyone have issues with the RCA 6AS7G background noise? Mine sounds like a quiet power line. Does it go away with burn in usually? Not a big issue but it is noticeable when I first put the headphone on.


----------



## pdrm360

cmander10 said:


> Anyone have issues with the RCA 6AS7G background noise? Mine sounds like a quiet power line. Does it go away with burn in usually? Not a big issue but it is noticeable when I first put the headphone on.


 
  
 Yes, most of them have this issues.


----------



## JamieMcC

cmander10 said:


> Anyone have issues with the RCA 6AS7G background noise? Mine sounds like a quiet power line. Does it go away with burn in usually? Not a big issue but it is noticeable when I first put the headphone on.


 
  
 Your Crack should be totally silent having had several issues with noise in the past they have all been due to outside influences and it took several weeks to dial them all out . The most frustrating was during the winter I and had a electric oil filled radiator in another room, in the evenings as the thermostat tripped it on it caused interference while heating up then 15-20mins later would trip off and all would be fine it drove me nuts till I figured it out. 
  
 I do have a couple of tubes that have a slight noise that can only be heard in the quiet gaps between songs and sometimes that is down to the pairing of the 12au7 not the driver tube. The Speedball upgrade I thought made a noticeable difference to perceived 12au7 noise. Tubes that I had run without it that where very quiet all of a sudden had noticeable noise. So it takes a little fine tuning if you hunt about there are a some posts on this on the bhf


----------



## cmander10

Had the electric noise from the RCA 6AS7G with both an RCA cleartop and Amperex Bugle Boy 12AU7s. The Bugle Boy has a buzz in the right ear so I'm returning it. It seems that the JAN version has less issues with microphonics. Don't know if vacuumtubes.net has any Chantham 6AS7Gs either.
  
 And my Crack is completely silent with the stock Raytheon 6080WA, so it must be the RCA 6AS7G.


----------



## liamstrain

I had some background hum/noise with my RCA 6AS7G - it cleared up after a dozen or so hours.


----------



## cmander10

liamstrain said:


> I had some background hum/noise with my RCA 6AS7G - it cleared up after a dozen or so hours.


 
 I think the noise is purely microphonic noises picked up from the transistor since I can hear a faint electric flow in that area. Unless the microphonics decreases then it will probably stay. 
  
 Did you have the standard RCA 6AS7G or the JAN version?


----------



## liamstrain

I have the JAN version.


----------



## Barry S

grausch said:


> @Barry S: That is a very clean build. I like the way you cleaned up around the nine-pin for the Speedball install. After seeing your build, I am seriously considering buying another Crack just so that I can get the wiring that clean. Currently I will really struggle to install the Speedball in my Crack.


 

 Thanks. I assembled the Speedball and read through the installation instructions before I started working on the Crack. Maybe you can redo some of your wiring to help with the Speedball install. I can't imagine you'd have to do that much to make it go in smoothly.


----------



## skeptic

Buzz can sometimes be cured by sanding or deoxidizing the pins. Doc shared this wisdom with me a couple of years back and saved me from binning a nice 1950s rca 12BH7.


----------



## grausch

barry s said:


> Thanks. I assembled the Speedball and read through the installation instructions before I started working on the Crack. Maybe you can redo some of your wiring to help with the Speedball install. I can't imagine you'd have to do that much to make it go in smoothly.


 
 Yes, I like the planning that you put into this. I built mine exactly as per the manual, and if there is one weak spot in the manual I would say that the routing of cables and the two caps on the terminal, could have been done differently to make upgrading to Speedball easier.
  
 Since it was my first build, I managed to nick some cables and capacitors with the soldering iron and being the perfectionist that I am, it bugs me. Would be nice to have a fresh attempt at another one and get everything really perfect. However, I can just replace the offending wires, and I am planning on upgrading some caps as well, so I might just go that route. Only problem I foresee is that I made sure I had excellent mechanical connections before soldering, and desoldering and removing those can get tricky.
  
 Shouldn't complain though, the Crack sounds excellent, I have no hum, no noise and no channel imbalance. I really struggle to see how the Speedball upgrade can make this amp sound better. I have not heard a lot of headphone amps, but to me it is the best I heard by far.


----------



## listen4joy

i am in the middle of bulding a crack and i have 2 questions.
  
 in the crack guide page 19

 what should i do the the revision or what in above? its written that revision will give me more quiet opreation is it true?
  
  
 the second thing that my little tube (12au7) is look like she is burned. on side has nothing and other side have blck grey thing with leak down that look like its burned
  
 pics
  
 1

  
 2

  
 3

  
  
 vids
  
 http://tinypic.com/r/ddl5xf/8
  
  
 http://tinypic.com/r/312ehau/8
  
 thnx for help!


----------



## grausch

I wired mine to 14U as the revision stated quieter operation. I did not want to desolder and I know that 14U can get crowded. Depending on how you decide to do this, you might need to use 14U from the beginning as desoldering there can be a pain.
  
 W.r.t. the 12AU7, mine also looks a little burned on top. I have no issues with the tube.


----------



## Doc B.

Moving the wire is simply an option. It really makes no difference, it just makes the grounding for that point follow our grounding phlosophy a little more closely. It is theoretically better but I doubt you could measure or hear a difference.
  
 The silver flashing you see in the top of the tube is the getter. It is supposed to be there.
  
 Don't worry, be happy.


----------



## mithrandir38

listen4joy said:


> i am in the middle of bulding a crack and i have 2 questions.
> 
> in the crack guide page 19
> 
> ...


 I would say don't do the revision. That post gets really crowded with that extra wire in there.


----------



## Utopia

Has anyone here tried to use the Crack as a preamp? I know the possibility has been mentioned here, as well as over at Bottlehead. Perhaps it'd be great with low impedance headphones, like Hifimans, with a small power amp in between?


----------



## liamstrain

I don't think it would work very well, with the output impedence as high as it is. Better off getting the BeePre or similar, if that's what you need.


----------



## Doc B.

liamstrain said:


> I don't think it would work very well, with the output impedence as high as it is. Better off getting the BeePre or similar, if that's what you need.


 
 ???? The output impedance of Crack is exceptionally low for a tube output line level device. In fact it is lower than any of our purpose made preamps. The circuit works fine as a preamp except for the lack of selectable inputs and the fact that it has an RCA jack at the output. In fact the topology is somewhat similar to our old Foreplay preamp. I do think the Smash works better as a preamp for the same kind of money. And of course there is also the possibility of using the S.E.X. amp for both low and high impedance headphones.


----------



## liamstrain

Ah - my apologies then. I misunderstood some things about the topology. Thanks for the correction, Doc.


----------



## Utopia

I've just tried Bottlehead Crack (Speedball, 5998) -> Audio GD SA-31 -> HE-500, and it sounds excellent, with a little bit of a bass increase, added warmth, and generally just very pleasant. .
  
 It's not a very efficient use of equipment, though, and not the chain I'm looking for. I hope to sell the SA-31 and replace it with something without input selection, volume control and all of that, just plain amplification - a headphone power amp - but there doesn't seem to be such a product category..


----------



## Loquah

utopia said:


> I've just tried Bottlehead Crack (Speedball, 5998) -> Audio GD SA-31 -> HE-500, and it sounds excellent, with a little bit of a bass increase, added warmth, and generally just very pleasant. .
> 
> It's not a very efficient use of equipment, though, and not the chain I'm looking for. I hope to sell the SA-31 and replace it with something without input selection, volume control and all of that, just plain amplification - a headphone power amp - but there doesn't seem to be such a product category..


 
  
 You'll find the HE-500s will sound better with other amps because the Crack is designed for higher impedance, but in the meantime, you could always keep the SA-31 and simply bypass the Crack's volume control to make it a pure power amp and use the SA-31 for volume control.


----------



## Keithpgdrb

utopia said:


> I've just tried Bottlehead Crack (Speedball, 5998) -> Audio GD SA-31 -> HE-500, and it sounds excellent, with a little bit of a bass increase, added warmth, and generally just very pleasant. .
> 
> It's not a very efficient use of equipment, though, and not the chain I'm looking for. I hope to sell the SA-31 and replace it with something without input selection, volume control and all of that, just plain amplification - a headphone power amp - but there doesn't seem to be such a product category..


 
 you would be better served to use a different amp.  the crack is actually the opposite of what you need in an amp for the 500.  you'd be amazed at the difference in switching that amp.


----------



## dreame77

Small question here: *How should I describe Bottlehead Crack OTL Kit at customs for calculation of TAX?*
 Amplifier? Tubes and cables?


----------



## Barry S

dreame77 said:


> Small question here: *How should I describe Bottlehead Crack OTL Kit at customs for calculation of TAX?*
> Amplifier? Tubes and cables?




Electronic parts? The tax rate on components is probably lower than on an amplifier.


----------



## VALIENTE

Guys, what are the very basic skills needed to DIY Crack aside from soldering and wire stripping?


----------



## Loquah

valiente said:


> Guys, what are the very basic skills needed to DIY Crack aside from soldering and wire stripping?


 
  
 That's pretty much it other than following instructions, turning a screw driver, gluing pre-cut pieces of wood together and using a test meter (by following clear instructions)


----------



## Doc B.

I would add a degree of patience and the urge to be thorough. A successful build is mostly about taking your time and enjoying the process. A functional result just kind of follows naturally. If you rush it you can miss steps, have to figure out what you skipped, go back and fix the error and in the end you will spend just as much time on the build.


----------



## Armaegis

The first time I built a Crack, I marathoned it in a single session then spent half a week debugging it.
  
 The second and third time I built one, I spent one day laying everything out and pre-cutting/stripping/tinning the wires and terminals, then two days with the actual build (plus a third for Speedball). Both worked without a hitch the first time I fired them up.
  
 Total effective build time was the same, but my second and third times were far more enjoyable and my workmanship was much better.


----------



## Bacci

So... my soldering iron has been idle for too long and I want to build a Bottlehead crack.
  
 For my cans (HD700) the output impedance of the Crack is probably borderline high (cans are 150ohm at 1000Hz with higher impedance at lower frequencies), but I already own a good SS amp and prefer to build an OTL rather than a hybrid. 
  
 I'm adding a DC offset protection circuit (AMB ε12) for peace of mind and a tube guard for the preamp tube which seems a little close to the volume knob and headphone cord:
  

  
 Question: Can anyone recommend film caps for the output stage that will still fit comfortably in the case?
  
 Thanks!


----------



## JamieMcC

bacci said:


> So... my soldering iron has been idle for too long and I want to build a Bottlehead crack.
> 
> For my cans (HD700) the output impedance of the Crack is probably borderline high (cans are 150ohm at 1000Hz with higher impedance at lower frequencies), but I already own a good SS amp and prefer to build an OTL rather than a hybrid.
> 
> ...


 
  
 The 100uf Solen and JFX both fit in easily, Mundorfs and Obbligato are a lot tighter


----------



## skeptic

My obbligatos are longer than the axons I replaced with them, but I didn't find it at all difficult to fit them in. There are photos of both configurations in my profile gallery if you want to see the spacing. 

AdamCTs use of 100uf claritycaps are the only build I can recall seeing that required risers to accommodate a single pair of output caps.


----------



## Bacci

Thanks JamieMcC & Skepic! I will make a choice based on your suggestions. Don't want to spend a fortune on boutique caps, those look reasonably priced.
  
 Also contemplating adding a USB port with a GrubDAC with an metal input toggle switch (if it ain't broke, it doesn't have enough features yet haha), but still on the fence about adding a digital input to a "retro" amp.


----------



## trentrosa

bacci said:


> Thanks JamieMcC & Skepic! I will make a choice based on your suggestions. Don't want to spend a fortune on boutique caps, those look reasonably priced.
> 
> Also contemplating adding a USB port with a GrubDAC with an metal input toggle switch (if it ain't broke, it doesn't have enough features yet haha), but still on the fence about adding a digital input to a "retro" amp.




Be careful with interference and noise putting a DAC under the hood.


----------



## pdrm360

Do you folks have any idea what the *warmest sounding tube* for Crack is?


----------



## Loquah

Mullards are a good bet


----------



## pdrm360

loquah said:


> Mullards are a good bet


 
  
 What about the power tubes?


----------



## Loquah

Mullards are available for both.


----------



## dreame77

Spent today 7 hours to do all soldering. Likely no mistakes. 
 And yes, with Beyerdynamic T1 it sounds great!


----------



## JamieMcC

dreame77 said:


> Spent today 7 hours to do all soldering. Likely no mistakes.
> And yes, with Beyerdynamic T1 it sounds great!


 
  
 Congratulations the Crack and T1 are a superb combination


----------



## dreame77

Speaking of soundstage size, HD700 with Magni is similar to T1 with Crack (with Magni it was too small). 
 It's hard to imagine how big would become soundstage of HD700 or HD800 with Crack... 
  
 And one more interesting thing: it is said that one need high-Ohm headphones...
 BUT I have no problems and distortions with Denon D600 (actually I need to turn volume knob 1,5 more), and with ZMF mod Fostex t50rp (twice the volume of T1). 
  
 May be it is due to maximum input power of headphones: D600 -- 1800 mW, t50rp -- 3000 mW ?


----------



## Doc B.

The issue isn't volume level. Lower impedance headphones will not be controlled as well in the bass region as they would by an amp with a lower output impedance. It's not like low impedance headphones won't work at all with a Crack. But if you do a side by side comparison with an amp designed for lower impedance headphones like a S.E.X. amp you will hear the differences.


----------



## grausch

dreame77 said:


> And one more interesting thing: it is said that one need high-Ohm headphones...


 
 I have a set of Shure SRH 440s (32 ohm) and the 250 ohm DT 770s. If I listen to the SRH440s with my cmoyBB, they sound very analytical with a very flat frequency response. The DT770s with the Crack tend to have accentuated bass and perhaps some accentuated treble with a slightly recessed midrange.
  
 If I listen to the SRH440s with the Crack, then the bass becomes very loose and flabby. I was quite amazed at the change in character. I definitely prefer the DT770s with the Crack.
  
 On another note, I can use the DT770s straight out of the iPhone, I lose some volume, but otherwise they tend to sound OK. Not as good as out of the Crack, but not as bad as the SRH440s with the Crack. Edit: Should add that I listen at low volumes. At higher volumes, the Crack / DT770 combo sounds a lot better than straight out of the iPhone.


----------



## Bacci

doc b. said:


> The issue isn't volume level. Lower impedance headphones will not be controlled as well in the bass region as they would by an amp with a lower output impedance. It's not like low impedance headphones won't work at all with a Crack. But if you do a side by side comparison with an amp designed for lower impedance headphones like a S.E.X. amp you will hear the differences.


 
  
 Most Senns have an impedance peak around 100 Hz due to resonance, how does this impact control in the bass region by OTL amps (which need high impedance cans for best performance)?
 If we take the HD598 for example with a nominal impedance of 50ohm, but with an actual impedance of > 120ohm in the 50-200Hz region: would that impedance peak mitigate the problem of controlling its low frequencies?
 In other words, if the impact of a bad dampening factor is mostly heard in low frequencies, would these cans perform a little better than one would expect based on their 50ohm nominal impedance (even though they would still be a bad match overall)? 
  
 Or is the impact of an impedance peak due to resonance to be understood differently?


----------



## dreame77

doc b. said:


> The issue isn't volume level. Lower impedance headphones will not be controlled as well in the bass region as they would by an amp with a lower output impedance. It's not like low impedance headphones won't work at all with a Crack. But if you do a side by side comparison with an amp designed for lower impedance headphones like a S.E.X. amp you will hear the differences.


 

 Thank you, now I get it!
 Why do I liked D600 with Crack -- it has much less prominent bass, healing overall balance. 
  
 But T1 with Crack is just awesome. The sound is stunning, I could not stop listening. May be it is due to my first experience with tube amps (Shiit Magni, Audinst mx2, Fiio e17 my previous)?
 Highs and mids are so beautiful, clear and liquid like. On the other side, while bass is pretty good, but not at the level of mids and highs. I am wondering would it be healed by Speedball Upgrade?


----------



## Keithpgdrb

grausch said:


> I have a set of Shure SRH 440s (32 ohm) and the 250 ohm DT 770s. If I listen to the SRH440s with my cmoyBB, they sound very analytical with a very flat frequency response. The DT770s with the Crack tend to have accentuated bass and perhaps some accentuated treble with a slightly recessed midrange.
> 
> If I listen to the SRH440s with the Crack, then the bass becomes very loose and flabby. I was quite amazed at the change in character. I definitely prefer the DT770s with the Crack.
> 
> On another note, I can use the DT770s straight out of the iPhone, I lose some volume, but otherwise they tend to sound OK. Not as good as out of the Crack, but not as bad as the SRH440s with the Crack. Edit: Should add that I listen at low volumes. At higher volumes, the Crack / DT770 combo sounds a lot better than straight out of the iPhone.


 
 Yeah, complete impedence mismatch with your 440's.  It should sound like crap on the crack, which apparently it does.  Read up on the amping requirements for these cans.  all of your observations are spot on.


----------



## grausch

keithpgdrb said:


> Yeah, complete impedence mismatch with your 440's.  It should sound like crap on the crack, which apparently it does.  Read up on the amping requirements for these cans.  all of your observations are spot on.


 
 Yeah, I know. I was merely quoting dreame77 and providing some insight into the differences between high and low impedance cans with the Crack. My low impedance cans have loose bass, which is what Doc B also suggests.
  
 It was quite an interesting test, as I did not expect the SRH440s to ever have uncontrolled bass.


----------



## liamstrain

dreame77 said:


> Highs and mids are so beautiful, clear and liquid like. On the other side, while bass is pretty good, but not at the level of mids and highs. I am wondering would it be healed by Speedball Upgrade?


 
  
 I'm not sure it will - what you are describing is pretty much what the T1s sounded like to me - not something to fix with an amp change, just their sound signature.


----------



## dreame77

liamstrain said:


> I'm not sure it will - what you are describing is pretty much what the T1s sounded like to me - not something to fix with an amp change, just their sound signature.


 
  
 To make it clear. The last phrase I wrote comparing change of sound after moving from Magni to Crack. Mids and highs changed a lot in a good way, but bass changed not to the same extent.


----------



## JamieMcC

dreame77 said:


> Thank you, now I get it!
> Why do I liked D600 with Crack -- it has much less prominent bass, healing overall balance.
> 
> But T1 with Crack is just awesome. The sound is stunning, I could not stop listening. May be it is due to my first experience with tube amps (Shiit Magni, Audinst mx2, Fiio e17 my previous)?
> Highs and mids are so beautiful, clear and liquid like. On the other side, while bass is pretty good, but not at the level of mids and highs. I am wondering would it be healed by Speedball Upgrade?


 
  
 The speedball does exactly what it say on Bottleheads product page
  
 "The most immediate thing you will notice is a better sense of clarity. Things get tighter and quicker, bass and midrange get cleaner and more dynamic sounding, and the background gets more quiet. As with all of our upgrade kits, the improvement is easily heard"
  
 You might want to take a little look later on at the Cracks upgrade path.  The T1's just scale amazingly well with a few selective easy to do mods. There are a few T1 users running modified Crack combos here.


----------



## indydieselnut

Hey guys, as a former Crack owner I thought I'd let people on this thread know that I just posted some beautiful custom Crack bases and an assortment of 6AS7G and 6080 power tubes over in the FS/accessories forum.  I sold my amp a while back and these have been hanging around since then.  Cheers!


----------



## Doc B.

bacci said:


> Most Senns have an impedance peak around 100 Hz due to resonance, how does this impact control in the bass region by OTL amps (which need high impedance cans for best performance)?
> If we take the HD598 for example with a nominal impedance of 50ohm, but with an actual impedance of > 120ohm in the 50-200Hz region: would that impedance peak mitigate the problem of controlling its low frequencies?
> In other words, if the impact of a bad dampening factor is mostly heard in low frequencies, would these cans perform a little better than one would expect based on their 50ohm nominal impedance (even though they would still be a bad match overall)?
> 
> Or is the impact of an impedance peak due to resonance to be understood differently?


 
 I think the graph probably answers the question. The hump of the 598 will mitigate some of the bass problem compared to a headphone that doesn't have as high an impedance hump. But the overall impedance is much lower than the other cans represented on the graph, even the bass hump. 800s and 650s are generally considered to sound good with the Crack. 700s maybe OK but not _as_ good.  So the graph might allow one to infer that for the most perfect pairing you want the impedance up above 300 ohms and the bass hump even higher. That has been my own experience.


----------



## dreame77

I guess I will wait for a week or so, to become familiar with pure Crack sound. 
 After that would install Speedball Upgrade. Hope to hear the same level of improvement as in case Magni->Crack =)
  
 By the way, is there anything from Bottlehead to upgrade from Schiit Modi?


----------



## olegausany

While HD700 is not as good as HD800 with the Crack it's still worth getting one, I owned both together for several months and really enjoyed the sound


----------



## Doc B.

We will be releasing a DAC soon, but it is not at all in the same price category as the Modi, it will be around $1500. The Modi is pretty great bang for the buck.


----------



## Jmstrmbn

A while back I bought a Mullard tube from Upscale Audio and have been using it with my crack since then.  Just switched it out and immediately noticed the bass is much less present.  I like that the treble is more forward though.  Anyone know a tube that will work with the Mullard to get the better highs while maintaining the awesome low end? 
  
 In case I wasn't clear looking for a power tube.


----------



## JamieMcC

jmstrmbn said:


> A while back I bought a Mullard tube from Upscale Audio and have been using it with my crack since then.  Just switched it out and immediately noticed the bass is much less present.  I like that the treble is more forward though.  Anyone know a tube that will work with the Mullard to get the better highs while maintaining the awesome low end?
> 
> In case I wasn't clear looking for a power tube.


 
  

http://www.ebay.co.uk/itm/Soviet-Double-Triode-Tube-6N13S-ECC230-6AS7G-2pcs-/251648362482?pt=LH_DefaultDomain_0&hash=item3a976947f2
  
  
 Svetlana "winged C" Don't let their low price put you off they are nice sounding tubes this is the seller I brought mine from I doubt you can go wrong for the money. You will often see them rebranded under the more well know names Mullard Amperex Hytron etc for $30-$50 a tube!


----------



## MIKELAP

jamiemcc said:


> http://www.ebay.co.uk/itm/Soviet-Double-Triode-Tube-6N13S-ECC230-6AS7G-2pcs-/251648362482?pt=LH_DefaultDomain_0&hash=item3a976947f2
> 
> 
> Svetlana "winged C" Don't let their low price put you off they are nice sounding tubes this is the seller I brought mine from I doubt you can go wrong for the money. You will often see them rebranded under the more well know names Mullard Amperex Hytron etc for $30-$50 a tube!


 
 I agree but some of them (RADIOKOMPONENT )advertise one thing and send you another and after say it was a mistake send them back for a refund they say which means we never had those tubes to start with, which pisses me off especially when you bother to ask beforehand  if the tubes are same year as picture .


----------



## JamieMcC

mikelap said:


> I agree but some of them (RADIOKOMPONENT )advertise one thing a send you another and after say it was a mistake send them back for a refund they say which means we never had those tubes to start which pisses me off especially when you bother to ask beforehand  if the tubes are same year as picture .


 

 I have had quiet a lot of varied gear from Romanian, Lithuania,  Bulgaria, Russia etc over the last couple of years including some quiet large and heavy items and have never had any issues using ebay, just be sure to use the guys with good feed back ratings.. In the link above with 1764 positive ratings in the last 12 months and only 1 negative and a rating of 99.9%  I would think the chances of getting what you have purchased are very high! I have used them at least half a dozen times and they have provided a very good service. 
  
 The old saying buyer beware still applies and it pays to be cautious and ask questions, most sellers are I think pretty genuine.


----------



## Jmstrmbn

Jamie, How do you like the tube?  I currently have whatever came with the kit.  It says slyvania in yellow lettering on the base.  What can I expect if I purchase the Winged C


----------



## JamieMcC

jmstrmbn said:


> Jamie, How do you like the tube?  I currently have whatever came with the kit.  It says slyvania in yellow lettering on the base.  What can I expect if I purchase the Winged C


 

 I have a couple which I purchased out of curiosity and they have turned out to be a bit of a surprise, I like them with the E80cc up front for the input tube and the performance to price ratio I would consider is way above average. Most probably you will need to be looking at tubes like the Tung sol 5998 or Bendix 6080 to find a really noticeable improvement on it and they cost 10-15 times as much! Premium 6080's like  the GEC 6080 & Mullard 6080 would most probably be considered superior sounding tubes, each has its own strong points in different areas of presentation while the Winged C is perhaps not quiet at the same levels of performance offers a more overall balanced presentation close on their heels. I find myself using it more and more for general listening and would chose it any day of the week over the standard RCA or Sylvania 6as7g's types I've tried in the past. Their inexpensiveness and Russian origin I think puts some people off who might tend to go with more familiar brands. If you are curious give them a go, tube rolling really doesn't get any cheaper for new old stock tubes.
  
 PS. Its also nice to be able to turn the amp on and leave it on of a evening and not worry about wasting the life of some expensive premium tube if I get distracted by other things (kids, wife, etc) and don't get back to listening for a couple of hours.


----------



## JamieMcC

I'm starting to list a few of the spare tubes I accumulated in the classified section as the Bottleheads Sex amp which is underway uses a different type so a thinning out seems in order.
  
  http://www.head-fi.org/t/736493/tung-sol-bendix-6080-wb-graphite-column-plates-free-uk-delivery


----------



## Loquah

No doubt there'll be a few gems in that lot!


----------



## ben_r_

Has anyone out there tried using a toroidal transformer with the crack?


----------



## JamieMcC

loquah said:


> No doubt there'll be a few gems in that lot!


 
  
 More than a few however I am finding it hard to let go!


----------



## Mak333

doc b. said:


> We will be releasing a DAC soon, but it is not at all in the same price category as the Modi, it will be around $1500. The Modi is pretty great bang for the buck.


 

 How soon?   Looking forward to pics on the main site!


----------



## JamieMcC

mak333 said:


> How soon?   Looking forward to pics on the main site!


 
 Doc's just put a prototype up for sale on the bhf


----------



## Doc B.

That proto was quite different than what we are coming out with. It also sold in 5 minutes, so no need to rush to the link. We're hoping to have the first set of panels for the new DAC early next week. If all goes as planned I may be able to post an image mid-week.


----------



## Loquah

doc b. said:


> That proto was quite different than what we are coming out with. It also sold in 5 minutes, so no need to rush to the link. We're hoping to have the first set of panels for the new DAC early next week. If all goes as planned I may be able to post an image mid-week.


 
  
 Now I just need to find someone with way too much money who wants to give me a nice wedding gift!


----------



## adamaley

jmstrmbn said:


> A while back I bought a Mullard tube from Upscale Audio and have been using it with my crack since then.  Just switched it out and immediately noticed the bass is much less present.  I like that the treble is more forward though.  Anyone know a tube that will work with the Mullard to get the better highs while maintaining the awesome low end?
> 
> In case I wasn't clear looking for a power tube.


 
 I've been in the same conundrum as you for the last week. I have been using the TS 5998 as power tube, then added the Mullard CV4003 (purchased from Upscale Audio as well). The sound has been relatively too lush for my liking even though the transparency is improved. I tried living with that combo for a while, but relented and stuck in a few other power tubes to tame some of the midrange smearing/euphonic traits. To my pleasant surprise, my old TS 7236 did just the trick. It's as close to the TS 5998 as one can get according to this great tube guide: http://the-key.enix.org/~krystal/review-tube-bottlehead.html. However, it's punchier, has better bass (IMO, it's tighter), and is less warm. They can be found on eBay for ~45. Good luck.


----------



## Jmstrmbn

Glad to see someone already figured out the winning combo but I just ordered a Sino 6as7g.  I'll keep a look out for the TS 7236 but will have to wait for funds to recuperate, its been an expensive month


----------



## adamaley

Lol. I am not ready to call this the winning combo yet. I have to admit that my system has been going through a lot of changes recently. I added a Schiit Wyrd, two new USB cables, and two new power cords, all in the space of a month. As a result , the top combo doesn't seem to tickle me the same as before. I would say it was too much of a good thing. Who knows, I may go back to it. However, the ailment you describe is similar to what I was experiencing, and hopefully, my fix works the same way for you. It's been an expensive month here as well, lol.


----------



## skeptic

doc b. said:


> That proto was quite different than what we are coming out with. It also sold in 5 minutes, so no need to rush to the link. We're hoping to have the first set of panels for the new DAC early next week. If all goes as planned I may be able to post an image mid-week.




Exciting news! Very much looking forward to seeing the initial photo(s).


----------



## Loquah

adamaley said:


> Lol. I am not ready to call this the winning combo yet. I have to admit that my system has been going through a lot of changes recently. I added a Schiit Wyrd, two new USB cables, and two new power cords, all in the space of a month. As a result , the top combo doesn't seem to tickle me the same as before. I would say it was too much of a good thing. Who knows, I may go back to it. However, the ailment you describe is similar to what I was experiencing, and hopefully, my fix works the same way for you. It's been an expensive month here as well, lol.


 
  
 There is a solution to this ailment... it's called the Mainline!


----------



## adamaley

loquah said:


> There is a solution to this ailment... it's called the Mainline!


 
  
 With all due respect, I doubt there is anything that can cure what ails us. We were all doomed once we stepped into Hi-fi.


----------



## Loquah

Yes. I'm afraid you're probably right. The Mainline has cured my amp upgrade-itis, but instead I turned my attention to my portable rig


----------



## adamaley

loquah said:


> Yes. I'm afraid you're probably right. The Mainline has cured my amp upgrade-itis, but instead I turned my attention to my portable rig


 
 As an aside, how well does the Mainline drive the LCD-2.2s and can you speculate on how well it will drive LCD-3s? I want to finally move on to an amp that can handle both high and low impedance headphones equally well, and I have read that the Mainline should fit that bill. What are your thoughts?


----------



## Loquah

The Mainline does a good job with the LCDs, but I find myself preferring the S.E.X. That could be more a question of signatures though because I've nodded the S.E.X. for a warm sound which is also why I bought LCD 2s. The Mainline's more neutral presentation may be more the cause than its actual ability to drive the LCDs.

I'll do some more comparative listening later today and share more then.


----------



## adamaley

Looking forward to your comparisons later. Thanks.


----------



## JamieMcC

loquah said:


> The Mainline does a good job with the LCDs, but I find myself preferring the S.E.X. That could be more a question of signatures though because I've nodded the S.E.X. for a warm sound which is also why I bought LCD 2s. The Mainline's more neutral presentation may be more the cause than its actual ability to drive the LCDs.
> 
> I'll do some more comparative listening later today and share more then.


----------



## Loquah

OK, so I've just tried the S.E.X. and Mainline with the LCD-2s (rev 2, Dec 2013) and am slightly wishing I hadn't...
  
 My setup is Matrix X-Sabre feeding S.E.X. and Mainline in parallel using identical RCA cables (Tara Labs). The S.E.X. has been upgraded with Mundorf Supreme Silver/Gold Oil output caps and some FT-3 Russian Teflons elsewhere in the chain. The Mainline has Auricaps running in what is essentially the position of an output cap and the same FT-3 russian teflons running in the power regulation circuit coupled to the 12AU7.
  
 In the past I've always preferred the S.E.X.'s extra power and warmth with the LCD-2s, but today's exercise had the Mainline way out in front. Details were sharper and clearer with the Mainline and the stage was more open. The treble energy and detail is better from the Mainline too, but still wonderfully smooth (a feature of the Auricaps I added, but the stock Mainline is great in this regard anyway). In the past I was craving the warmth of the LCD 2s, but I think my tastes have shifted (which seems to happen from time to time) and the Mainline is now clearly superior.
  
 I volume matched as best I could by ear and the dynamics seemed very similar on both amps - it was only resolution and signature that changed so I'm confident that volume wasn't a contributing factor. I even turned the S.E.X. up so it was definitely louder than the Mainline and the Mainline still had an edge.
  
 I should clarify at this point that the S.E.X. still sounds outstanding with the LCD 2s and it may just be a case of my capacitor choices smoothing things over too much... hmmmm... maybe it's time for a fresh set of caps in the S.E.X.??
  
 To answer your question @adamaley, the Mainline fits the bill perfectly and does wonders with every headphone I've ever thrown at it. It's an amp that honestly does cure upgrade-itis (for the desktop amp section of your rig at least)
  
 EDIT: Forgot to add that I ran both setups in balanced with the Mainline set to low impedance mode. The Mainline volume was on around -12dB so there's only 1 step left on the coarse attenuator and 10 steps total (I think) to reach full volume so if you like your ears bleeding the Mainline might lack the juice, but I doubt anyone would really want that much volume as I was probably listening at around 80dB so getting up towards full volume is long term hearing damage territory. The S.E.X. on the other hand was purring away at about 50% on the stepped attenuator.


----------



## adamaley

Thanks a lot, @Loquah. Wonderful insight.


----------



## Jmstrmbn

Got the Chinese Sino 6as7g in today.  Will post some thoughts once I've given it a few days to adjust to it's new home!


----------



## Melange

Hi everyone. I was wondering if anyone here has experience with the HD650 matched with both the Crack and the Crack with Speedball upgrade. I'm currently running my HD650s with a Schiit Modi and Vali combo. It's not bad, but I find the sound just a little bit on the lean side, for lack of any better way of putting it. I plan on upgrading to a Crack sometime in the near future.
  
 My question is this: does the Speedball upgrade noticeably change the output of the Crack so that the tonal balance of the HD650 will be leaner? I hear that it improves the soundstage, timing, gives a blacker background and so forth. Now that sounds great, but what I love about the HD650 is the warm, laid-back sound with the slightly euphonic coloration in the mid-bass and lower midrange, and if the Speedball reduces this in the same way that I feel the Modi/Vali does, then I would choose not to buy it.
  
 I'd greatly appreciate any input you guys could provide, thanks.


----------



## Deterministic NL

melange said:


> Hi everyone. I was wondering if anyone here has experience with the HD650 matched with both the Crack and the Crack with Speedball upgrade. I'm currently running my HD650s with a Schiit Modi and Vali combo. It's not bad, but I find the sound just a little bit on the lean side, for lack of any better way of putting it. I plan on upgrading to a Crack sometime in the near future.
> 
> My question is this: does the Speedball upgrade noticeably change the output of the Crack so that the tonal balance of the HD650 will be leaner? I hear that it improves the soundstage, timing, gives a blacker background and so forth. Now that sounds great, but what I love about the HD650 is the warm, laid-back sound with the slightly euphonic coloration in the mid-bass and lower midrange, and if the Speedball reduces this in the same way that I feel the Modi/Vali does, then I would choose not to buy it.
> 
> I'd greatly appreciate any input you guys could provide, thanks.


 

 I won't get into the science of it all but I have a Crack with Speedball and HD650's and I'm generally happy.  Sounds amazing.  My source is MacMini and Fiio E17 DAC and admittedly I bump the treble in the DAC a hair because I find it a bit lean without it.   I'm a top end guy.  I want cymbals.
  
 Consequently I have a Schiit Modi / Magni and while I love it I actually prefer HD598 with it and even Sony MDR-V6.  HD650 are great but of course high impedance cans.


----------



## JamieMcC

deterministic nl said:


> I'm a top end guy.  I want cymbals.


 
 You might like to try fitting some of these as bypasses to the 100uf output caps. Lets your cymbals shimmer all ting and no shing
  
http://www.ebay.co.uk/itm/0-056uF-500V-A-A-5-TEFLON-Capacitor-K72P6-/380940922798?pt=Vintage_Electronics_R2&hash=item58b1d92fae


----------



## Deterministic NL

jamiemcc said:


> You might like to try fitting some of these as bypasses to the 100uf output caps. Lets your cymbals shimmer all ting and no shing
> 
> http://www.ebay.co.uk/itm/0-056uF-500V-A-A-5-TEFLON-Capacitor-K72P6-/380940922798?pt=Vintage_Electronics_R2&hash=item58b1d92fae


 

 Thanks. I just ordered two and will give it a shot.  I always thought the Crack was a touch weak up top (with the HD650) but the Fiio E17 with the treble control is perfect for it.


----------



## Utopia

I read the latest Hifiman HE-560 review over at Headfonia and found the following to be very interesting:
  


> Surprise of the last few weeks was the nice match with the Bottlehead Crack. Usually that one doesn’t work with orthodynamic headphones at all. Here however you get tube smoothness and warmth with a slower sound but it just works for me. Good bass, smooth mids and soft treble. Love it. Volume goes almost all the way up but I quite like the result. Who would have guessed?


 
  
 I've read somewhere that with certain tubes the Crack output impedance can get as low as 70 ohm. And the HE-560 is 50 +/- 8 ohm. Not a terribly large difference. Perhaps it's something to try?


----------



## vegaobscura

jmstrmbn said:


> Got the Chinese Sino 6as7g in today.  Will post some thoughts once I've given it a few days to adjust to it's new home!


 
 Definitely interested in hearing some thoughts on these! I'm in the market for a new tube and would like to hear more about the Chinese equivalents (Shuguang 6N13PT, the Sinos, ...etc) before grabbing an old RCA or something.


----------



## Keithpgdrb

utopia said:


> I read the latest Hifiman HE-560 review over at Headfonia and found the following to be very interesting:
> 
> 
> I've read somewhere that with certain tubes the Crack output impedance can get as low as 70 ohm. And the HE-560 is 50 +/- 8 ohm. Not a terribly large difference. Perhaps it's something to try?


 

 seems like a waste of time to me.  trying to use an amp outside its peak design parameters is just an exercise in compromise.  The 560 is not difficult to drive, amps that do a great job are not expensive.  IMHO.


----------



## Aeolus Kratos

jamiemcc said:


> You might like to try fitting some of these as bypasses to the 100uf output caps. Lets your cymbals shimmer all ting and no shing
> 
> http://www.ebay.co.uk/itm/0-056uF-500V-A-A-5-TEFLON-Capacitor-K72P6-/380940922798?pt=Vintage_Electronics_R2&hash=item58b1d92fae


 
 I just want to second this wonderful recommendation. I've just installed these caps and burned it for about 200 hours and the difference was very noticeable. The top end was clearer, more sparkling but smoother at the same time, the resolution was improved generally. And most importantly, these caps just cost you a cup of coffee. Highly recommended!
  
 Thanks Jamie!


----------



## Jmstrmbn

Well I've put a good 15hrs on the Sino so far and the differences from the stock 6080 are starting to become clear.  In general there was an improvement in all aspects of the sound.  The noise floor is lower. The bass has evened out and is not more taught, less boomy.  The midrange seems to have retained similar character but with less bleed over from the bass can sound a bit too lean on some tracks but I find it more accurate sounding for 75% of what I've been listening to.  The highs have become much less grainy, more extended and more articulate.  I get a better sense of air in the soundstage.  The only real negative so far is that the sound stage seems wider and flatter compared to deeper and more squished, this is really track dependent so take it with a grain of salt.  
  
 Overall I'm extremely happy with the upgrade for the price.  I'm not sure how long tubes typically take to settle down but I will report any differences after another week or so.
  
 BTW this is without the speedball and using HD600s.  DAC is Nuforce HDP.
  
 Happy listening and enjoy your Cracks!


----------



## JamieMcC

aeolus kratos said:


> I just want to second this wonderful recommendation. I've just installed these caps and burned it for about 200 hours and the difference was very noticeable. The top end was clearer, more sparkling but smoother at the same time, the resolution was improved generally. And most importantly, these caps just cost you a cup of coffee. Highly recommended!
> 
> Thanks Jamie!


 
  
 Hi Aeolus, good to hear they worked well for you to!  They are a inexpensive mod to try and the effects are particularly welcome if your a Beyerdynamic T1's user, at times the T1's can have to aggressive top end with particular tracks/artists which can result in them being prone to some cringe worthy sibilance. With the addition of the Teflons their Achilles heel of the sibilant treble presentation was totally resolved and the top end became noticeably more refined and resolving other areas benefit also.
  
 You might like to try disconnecting a lead once you have been using them for a while to re-reference the sound of the 100uf's with out them, it was a bit of a shock!  Mine went back in the circuit  pretty quickly.


----------



## skeptic

jamiemcc said:


> Hi Aeolus, good to hear they worked well for you to!  They are a inexpensive mod to try and the effects are particularly welcome if your a Beyerdynamic T1's user, at times the T1's can have to aggressive top end with particular tracks/artists which can result in them being prone to some cringe worthy sibilance. With the addition of the Teflons their Achilles heel of the sibilant treble presentation was totally resolved and the top end became noticeably more refined and resolving other areas benefit also.
> 
> You might like to try disconnecting a lead once you have been using them for a while to re-reference the sound of the 100uf's with out them, it was a bit of a shock!  Mine went back in the circuit  pretty quickly.


 
  
Jamie - are these the ones that you have to cover with some sort of heatshrink because the outside is conductive?  You guys are seriously tempting me to give the ole crack a little update!


----------



## JamieMcC

skeptic said:


> Jamie - are these the ones that you have to cover with some sort of heatshrink because the outside is conductive?  You guys are seriously tempting me to give the ole crack a little update!


 
  
 Hi skeptic I did originally cover mine with a precautionary covering of clear heat shrink prior to fitting. However after taking one apart they look to be very well insulated both in the ends and body from the metal shell with a generous wrapping of teflon after the actual foil part ends. I suspect the heat shrink is actually not required. Interestingly the internal leads that connect to the steel pins for hooking up look to be made of silver wire!
  
 I have made some woody versions but have yet to try them


----------



## skeptic

Thanks for the further info Jamie! I couldn't resist and ordered up a pair. Really looking forward to hearing them!


----------



## JamieMcC

skeptic said:


> Thanks for the further info Jamie! I couldn't resist and ordered up a pair. Really looking forward to hearing them!


 
  
 You will be pleased to know they take a lot less time to burn in than those RTI teflons!


----------



## skeptic

Good to know! I think the RTIs are still evolving but I am loving the sound regardless. If these imbue a little of the same teflon goodness in the crack, I'll be thrilled!


----------



## larcenasb

A question of concern: I was told that 470uF output caps were too much for the application of the Crack.
 No disrespect to the others, but in my experience, I find the sound of my Roe 470uF 160V caps to be SO MUCH BETTER than the stock 100uF Epcos caps -- I'm unwilling to compromise. The Epcos sounds thin in the mids and a bit strained, lacking power reserves; I'm constantly trying to adjust the volume to find satisfaction. The Roes sound powerful even at low volumes, and have fleshy, natural mids. Bass also is much more potent.
  
 This also enlightened me about the dependency of "the whole" in regards to tube performance. With the Epcos, my Mullard 12AU7 [k61 date code] sounds weak and thin; my Ken-Rad VT-231 (w/ an adapter) sounds more natural and powerful, but still not quite right for me. With the Roe caps, my Mullard sounds lush, beautiful and powerful (perfect for me); my Ken-Rad sounds mechanical in the mids but super powerful in the bass.
  
 'crappyjones123' shared similar sentiments: "also, installed sprague 470uf 200v electrolytic caps for output caps. bass is nicer. but overall tone has gotten bloomier."
_The bloom is very welcome in my AKG K612s which can be a tad clinical sounding._
  
 I've used the Roe 470uF caps for months before I was told I shouldn't. So, in my experience, they were never troublesome.
  
 However, I do want a safe and stable amp for years to come. So... what exactly are the negative effects of using 470uF output caps in the Crack? What is cause for concern? And is there any alteration I can make to allow the use of the 470uF caps?
  
 Thanks so much.
  
 (image missing)
 -larcenasb(image missing)


----------



## JamieMcC

I am wondering if the cause for concern was if using the 470uf value in the power supply rather than as output/coupling caps and I remember seeing something this about it being related to the transformer? The more common route with regards to the 100uf electrolytic output capacitors appears to be replacing them with a film equivalent.


----------



## Doc B.

Who said it was bad to use them?


----------



## larcenasb

Thanks JamieMcC. Yeah, what intrigues me is how many testimonies I've read, ppl claim they _may_ be able to tell a difference with the 100uF film caps, or they _think _there _might_ be a small difference for the better. Conversely, as I said in the post above, the 470uF cap is no small difference.
  
 However, it was clear to the others that the caps were used as the outputs, not in the power supply.
  
 Can anyone explain this? What's the problem?


----------



## larcenasb

Hi Doc!
  
 I think ppl were hinting at it being bad but I don't understand; why? Can you then verify that it is indeed okay to use the 470uF output caps?
  
_Remember too that my AKG K612s are 120ohms, so I'm trying to tailor the amp better toward them._
  
 Thanks.


----------



## GrindingThud

It's not bad.... Bigger lowers the frequency cutoff:
http://www.sengpielaudio.com/calculator-RCpad.htm
Rule of thumb is 10:1 keeps the phase even (set the cap for ~2Hz). 470uf is close enough, many manufactures use that value.


----------



## JamieMcC

larcenasb said:


> Thanks JamieMcC. Yeah, what intrigues me is how many testimonies I've read, ppl claim they _may_ be able to tell a difference with the 100uF film caps, or they _think _there _might_ be a small difference for the better. Conversely, as I said in the post above, the 470uF cap is no small difference.
> 
> However, it was clear to the others that the caps were used as the outputs, not in the power supply.
> 
> Can anyone explain this? What's the problem?


 
  
 Differences in perception are I would think very much source tube and phone dependent some tubes and phone combinations just don't have the ability to be resolving enough for the differences in component swapping to become noticeable. I bet you could get a couple of dozen Crack users together and the odds would be pretty good they would all be using different combinations of tubes, phones, caps, attenuators. Listening with say the DT 770 to a stock crack is a very different experience to listening to tricked out Crack with a flagship headphone there is no comparison. As much as I like my HD650 they can not hold a candle to the T1's when it comes to resolving such details.

 Having tried a number of combinations of film output caps of varying values the lowest was 47uf and highest has been 210uf some configurations are clearly personally preferable to me than others. My own personal preference funnily enough are not audio rated caps. Generally I find the differences between capacitors extremely difficult to make out if your listening to fast of busy music. As I listen to mostly acoustic and vocally led music myself the differences in textures and tone I find to be more noticeable with acapella recordings. 
  
 Most probably one of the Cracks greatest strengths is its adaptability to suit the personal tastes of who ever is listening and that's what really matters what works for you..  
  
 There was a brief discussion on one of the BHF threads recently about substituting the 220uf caps in the power supply with much larger ones and may have got my wires crossed.


----------



## JamieMcC

grindingthud said:


> It's not bad.... Bigger lowers the frequency cutoff:
> http://www.sengpielaudio.com/calculator-RCpad.htm
> Rule of thumb is 10:1 keeps the phase even (set the cap for ~2Hz). 470uf is close enough, many manufactures use that value.


 
  
 There is a chart around which combines the cut off with the impedance of the phones being used, I read it as the higher the impedance of phones used the lower the uf value required for the same frequency cut off.
  
 Edit


----------



## larcenasb

Thank you GrindingThud & JamieMcC. I feel much more at ease now  _happy listeninggggggg!_


----------



## Jimmy24

How does the Bottlehead Crack + Speedball compare in sound with the O2 + ODAC? I'm about to upgrade my amp/dac for my Senn HD 650's but I was wondering for those of you that have heard both amp/dac combos, I'd like to know if it's worth the upgrade? Thanks!


----------



## skeptic

jimbo24 said:


> How does the Bottlehead Crack + Speedball compare in sound with the O2 + ODAC? I'm about to upgrade my amp/dac for my Senn HD 650's but I was wondering for those of you that have heard both amp/dac combos, I'd like to know if it's worth the upgrade? Thanks!




The crack with speedball will be a big change and a major improvement in listening enjoyment with hd650s if your ears are anything like mine. I actually like my agdr boosted o2 quite well with alpha dogs and other fostex t50rp variants. It is also pretty good with dt880s since they have kind of a diffuse presentation and the o2 helps to focus them and give them a nice impactful, albeit slightly lean sound. But hd650s are already very coherent sounding headphones as far as instrument separation, and the o2 just makes them sound compressed and rather unremarkable in comparison. Timbre also takes a big hit. 

Plug into a crack and you will immediately understand the hype. It is just an excellent pairing that brings out the 650s soundstage, yields rich full lifelike timbre, and draws you right into the music. It is not a slow tubey sound like the woo otls. It is a punchy, dynamic involving match which will also hit harder and provide more substance in the bass than your o2, although at the cost of some bass tightness (which you will not miss in the least on balance). Building the kit and getting to participate in the extended bottlehead community is also extremely rewarding and is a big part of what has kept me interested and active on headfi for all these years. Plus, as Doc always says, it really does sound better when you build it yourself.


----------



## mcandmar

^ everything he said. I also have a modified O2 with agdr's booster board which sounds great with Grados and other low impedance cans.  With the HD650's i always found they sounded flat and lifeless, and dare i say it "veiled".  A crack really does transform them.


----------



## jimification

skeptic said:


> The crack with speedball will be a big change and a major improvement in listening enjoyment with hd650s if your ears are anything like mine. I actually like my agdr boosted o2 quite well with alpha dogs and other fostex t50rp variants. It is also pretty good with dt880s since they have kind of a diffuse presentation and the o2 helps to focus them and give them a nice impactful, albeit slightly lean sound. But hd650s are already very coherent sounding headphones as far as instrument separation, and the o2 just makes them sound compressed and rather unremarkable in comparison. Timbre also takes a big hit.
> 
> Plug into a crack and you will immediately understand the hype. It is just an excellent pairing that brings out the 650s soundstage, yields rich full lifelike timbre, and draws you right into the music. It is not a slow tubey sound like the woo otls. It is a punchy, dynamic involving match which will also hit harder and provide more substance in the bass than your o2, although at the cost of some bass tightness (which you will not miss in the least on balance). Building the kit and getting to participate in the extended bottlehead community is also extremely rewarding and is a big part of what has kept me interested and active on headfi for all these years. Plus, as Doc always says, it really does sound better when you build it yourself.


 
 Thanks for that, very helpful as I was wondering the same question myself.
  
 I know it's better to build the crack first but would you order with speedball and add it in pretty quickly, or live with the straight crack for a while? thanks.


----------



## JamieMcC

I think there is a discount if you order a Crack and Speedball at the same time, you will also save on a second lot of shipping at a later date. There are more than a few builders about who prefer Crack without speedball and the Crack certainly sounds good without it. I ordered both at the same time and only lasted a week before I could not resist the urge to get the soldering iron out again and  fit it.


----------



## Doc B.

Arrgh, IOS 8 just blew away my post. In a nutshell, 470 ohms is fine, bigger than you need for 120 ohm cans. I suspect that the materials and construction are influencing the sound quite a bit, perhaps more than the big cap value.


----------



## skeptic

jimification said:


> Thanks for that, very helpful as I was wondering the same question myself.
> 
> I know it's better to build the crack first but would you order with speedball and add it in pretty quickly, or live with the straight crack for a while? thanks.




My pleasure! Re the speedball, I'll echo what Jamie said. 

The stock build already sounds very good with high ohm phones. Plus, you want to be able to confirm the basic build is up and running and measures correctly before introducing more complexity into the circuit. 

The one caveat is that there are a couple of nylon standoffs (in the speedball kit) that screw on to the existing a-socket screws - on which one of your speedball boards will ultimately sit. If you have a chance to screw those on when doing the initial chassis hardware for the stock kit, and before doing any of the hookup wire on the a-socket, it can help avoid potential issues down the road (if the a-socket wires end up being in the way of the standoffs). I had this happen and was a little too rough in pushing those wires aside when adding my speedball standoffs and consequently damaged one of the a-socket LEDs. So if you have any concern that you may be a clumsy oaf like me, this can help avoid the issue. Many others have certainly managed to add their speedball standoffs without any trouble.


----------



## larcenasb

The "materials and construction", yeah, that makes a lot of sense, Doc. I can tell my 470uF Roe output caps are definitely quality components. Thanks so much for the reassurance in terms of matching. I can't believe the sound I'm getting with my amp now -- with the newly installed speedball as well. Simply PURE, transportive, and all with vast power reserves.


----------



## larcenasb

Here's my final build  Definitely satisfied and enjoying the music.


----------



## adamaley

Well, just when you thought all was right with the world, this happened: http://bottlehead.com/smf/index.php?topic=6898.0
  
 World turned upside down.....


----------



## Armaegis

adamaley said:


> Well, just when you thought all was right with the world, this happened: http://bottlehead.com/smf/index.php?topic=6898.0
> 
> World turned upside down.....


 
  
 That one, the Yggdrasil, and the DDDAC 1794 have sorta been on my radar for the last little while.


----------



## adamaley

Decisions, decisions......lol.


----------



## Jimmy24

Thanks for the helpful comments guys. I'm definitely looking into purchasing BHC+SB very soon.
  
 Another question I have is how to hook it up to my computer cheaply? I heard that I'll need a USB DAC but I don't really want to spend that much on one. Also, by adding a DAC would it change the sound signature by a lot and do I really need a good one to get the most out of my BHC+SB w/ my HD650s? Also, is there a way of hooking up the BCH+SB directly to my PC w/o a USB DAC? 
  
 Recommendations are much appreciated!


----------



## olegausany

You have to use Dac


----------



## JacobLee89

jimbo24 said:


> Thanks for the helpful comments guys. I'm definitely looking into purchasing BHC+SB very soon.
> 
> Another question I have is how to hook it up to my computer cheaply? I heard that I'll need a USB DAC but I don't really want to spend that much on one. Also, by adding a DAC would it change the sound signature by a lot and do I really need a good one to get the most out of my BHC+SB w/ my HD650s? Also, is there a way of hooking up the BCH+SB directly to my PC w/o a USB DAC?
> 
> Recommendations are much appreciated!


 
  
 You'll need a DAC AND a 3.5mm to stereo phono RCA cable to get the most of your BHC.
  
 Alternatively you can just get that cable, hook it from your onboard sound onto your BHC and see if you like it. Computers have "clean" power in terms of getting power to electronics, but are riddled with tones of oscillation which can be easily picked up by ears alone. Speakers are powered by electricity, you can imagine how it'll sound if they are powered directly via the computer.
  
 Now apply this to an amp, which by default should just amplify whatever it's been fed. If it is full of noise, then you'll get louder noise in return.
  
 Most USB DACs are powered by USB, but also include their own power regulator that removes a significant amount of noise, hence why a good amount of us like external DACs over PC sound cards.
  
 A DAC I began and could recommend for the budget minded is the ELE D01, which performed admirably. That should provide a low enough noise level to prevent things sounding like it's constantly raining, without breaking the bank.


----------



## ben_r_

adamaley said:


> Well, just when you thought all was right with the world, this happened: http://bottlehead.com/smf/index.php?topic=6898.0
> 
> World turned upside down.....


 

 Yep, created a thread on it here: LINK


----------



## Doc B.

armaegis said:


> That one, the Yggdrasil




We're thinking about calling ours Stamford Bridge.


----------



## Armaegis

doc b. said:


> We're thinking about calling ours Stamford Bridge.


 

 Any particular reason for that?
  
 Given that it leads to Crack and Mainline etc, I was thinking you'd name it after some sort of gateway imbibement.


----------



## adamaley

Doc is probably a Chelsea Football Club fan. Lol.


----------



## atsq17

Going to have to pass on it then. I can't possibly support anything with a name like Stamford Bridge.   YNWA!


----------



## Loquah

armaegis said:


> Any particular reason for that?
> 
> Given that it leads to Crack and Mainline etc, I was thinking you'd name it after *some sort of gateway imbibement*.


 
  
 Maybe they should call it The Spoon or The Measure or The Gate


----------



## Doc B.

you gotta do a little work - Wikipedia the battle of Stamford Bridge.


----------



## skeptic

Well played!


----------



## Loquah

Haha. Nice one, Doc!


----------



## Armaegis

doc b. said:


> you gotta do a little work - Wikipedia the battle of Stamford Bridge.


 
  
 So... we're all vikings?


----------



## JamieMcC

armaegis said:


> So... we're all vikings?


 

 Schitt happens


----------



## Jimmy24

Thanks for your response and your recommendation. After some consideration, I'm thinking of getting a good DAC that pairs well with BHC+SB. My price range can go up to $400 for the DAC.
  
 Btw, I own HD 650's.
  
 Any suggestions? 
  
  
 Quote:


jacoblee89 said:


> You'll need a DAC AND a 3.5mm to stereo phono RCA cable to get the most of your BHC.
> 
> Alternatively you can just get that cable, hook it from your onboard sound onto your BHC and see if you like it. Computers have "clean" power in terms of getting power to electronics, but are riddled with tones of oscillation which can be easily picked up by ears alone. Speakers are powered by electricity, you can imagine how it'll sound if they are powered directly via the computer.
> 
> ...


----------



## grausch

doc b. said:


> you gotta do a little work - Wikipedia the battle of Stamford Bridge.


 
 Doc B.,
  
 I assume you are referring to the following, extracted from wikipedia, - "The battle has traditionally been presented as symbolising the end of the Viking Age". Look forward to seeing pics of the final product.


----------



## Doc B.

Yup, I didn't think it would be as obscure a reference as it seems to be. I was just having a little fun at the expense of the great guys at Schitt. I live in what began as a fishing village established by Norwegian immigrants. Every other person's name ends in Son, the high school football team is the Vikings, the streets have names like Jensen Way, Fjord Drive and Lundegaard, and we have not one but two Viking statues in town. So the idea was not a big stretch for me.


----------



## Loquah

So Doc, is that the real proposed name or was it some fun on the forum only?


----------



## skeptic

loquah said:


> So Doc, is that the real proposed name or was it some fun on the forum only?


 
  
 Pre-order is live, so guessing the official name for now is "Bottlehead Dac" - http://bottlehead.com/product/bottlehead-dac/
  
 Now to go home and negotiate with my better half.


----------



## VALIENTE

Fellow Asian headfiers, Headfonia Store in Jakarta Indonesia sells Crack however for their countrymen only. Headfonia doesn't ship outside their country. Guys, do you know a store that ships Crack outside the country? I intent to buy in our continent only than US to minimize shipping time. Singapore or Hongkong maybe.Thanks.


----------



## rozunoe

If anyone wanted to get the Crack + Speedball, now would be a good time with the $299 sale for both. 
  
 http://bottlehead.com/?product=crack-otl-headphone-amplifier-kit


----------



## JamieMcC

Well I have lost count of how many times my finger has hovered over the buy it now button for the 12au7 to 6sn7 adapter but I finally bit the bullet and headed down the 6ns7 rabbit hole!
  
 Its so far so good with my first purchase, a early NOS National Union 6ns7gt black glass and it is proving to be real Cracker! Pleased to report no adapter noise issues either as some have experianced.


----------



## i luvmusic 2

I used 6/12SN7 for my CRACK made my own adapter................


----------



## Mahdi8

Finally got a chance to upgrade my volume pot to a stepped attenuator from ebay. So far I'm really happy with it. balance is perfect at any volume and much detailed and cleaner sound even on lower volume which with the stock volume control I need to crank the volume a 
  
 bit more to hear the same details. Then again it might just be in my head  overall quite happy with the upgrade


----------



## mordicai

I keep meaning to install an attenuator. Can you post the ebay address.


----------



## Mahdi8

Sure it's http://www.ebay.com.au/itm/301339516227?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649


----------



## JamieMcC

mahdi8 said:


> Finally got a chance to upgrade my volume pot to a stepped attenuator from ebay. So far I'm really happy with it. balance is perfect at any volume and much detailed and cleaner sound even on lower volume which with the stock volume control I need to crank the volume a
> 
> bit more to hear the same details. Then again it might just be in my head  overall quite happy with the upgrade


 
 Neat work Mahdi its hard to see in the pic but if you have not done so the left and right grounds on the attenuator need linking together from a safety stand point.


----------



## grausch

jamiemcc said:


> Neat work Mahdi its hard to see in the pic but if you have not done so the left and right grounds on the attenuator need linking together from a safety stand point.


 
 I believe I see that joint on the 2nd to right ground wire. Looks like grounding was done to the outer ring to connect both grounds. I could be mistaken, as I can't off-hand remember which ground is connected to the top and bottom ring, and the photo is a little blurry at that spot.
  
 However, using those spots to solder all the connectors to was quite smart. I used the conventional spots in my Stereomour, and it meant cutting the shielded wire to different lengths. A bit of a pain in the end, and this looks much easier.


----------



## Mahdi8

yeap that right I've liked the ground to the outer link I reckon it's going to be a cleaner solder than having a separate cable joining the ground. I didn't do it at first actually and it causes a horrible humming sound


----------



## grausch

mahdi8 said:


> yeap that right I've liked the ground to the outer link I reckon it's going to be a cleaner solder than having a separate cable joining the ground. I didn't do it at first actually and it causes a horrible humming sound


 
 It was pretty smart routing them that way.
  
 On the Stereomour I ended up with a ground cable that was just slightly too short, so needed to ground it on the outer ring. All of my ground wires were difficult to attach because of the varying lengths between in/out and ground. I never seemed to get the lengths right first time.
  
 Interesting comment about the hum without linking the grounding. I wanted to see the difference, but completely forgot to leave out the that connection. On the Stereomour I do not have the grounds connected as the schematic did not call for it, but I have no problem with hum.


----------



## atraf

Added the schiit modi, new spiked feet and waxed the wood


----------



## Aeolus Kratos

atraf said:


> Added the schiit modi, new spiked feet and waxed the wood


 
 It seems like you're using a pair of Morrow Audio ICs if I'm not wrong. Which model do you use? I've enjoyed my MA-3 very much!


----------



## atraf

aeolus kratos said:


> It seems like you're using a pair of Morrow Audio ICs if I'm not wrong. Which model do you use? I've enjoyed my MA-3 very much!


 
 Nice catch, its the MA-1, they are a great value IC's.


----------



## i luvmusic 2

Any suggestions on how to make a OUTPUT SELECTOR SWITCH.
  I want a switch box that have 1 input and 5 output.
  
  
 THANKS!


----------



## Jimmy24

Bottlehead has a sale of $95 off Speedball when you purchase the Crack!!!
  
 "This week only, order a Crack amp kit for $279 and you can add the Speedball upgrade kit for just $20! (regularly $115) Offer ends Sunday October 26th."
  
  
 http://bottlehead.com/?product=crack-otl-headphone-amplifier-kit


----------



## JamieMcC

i luvmusic 2 said:


> Any suggestions on how to make a OUTPUT SELECTOR SWITCH.
> I want a switch box that have 1 input and 5 output.
> 
> 
> THANKS!


 
  
 You might find something here
  
http://glass-ware.stores.yahoo.net/atandsise.html


----------



## i luvmusic 2

jamiemcc said:


> i luvmusic 2 said:
> 
> 
> > Any suggestions on how to make a OUTPUT SELECTOR SWITCH.
> ...


 
 THANKS!


----------



## daltonljj

First time building so thought I share my complete product. Cheers
 .
  
 Gonna try tube rolling soon.


----------



## grausch

The ?gold? top plate and transformer bell look really good. Care to post some more pics?


----------



## i luvmusic 2

daltonljj said:


> First time building so thought I share my complete product. Cheers
> .
> 
> Gonna try tube rolling soon.


 
 Looks nice,I have not finish my Case yet can't decide what to do with them.


----------



## JamieMcC

daltonljj said:


> First time building so thought I share my complete product. Cheers
> .
> 
> Gonna try tube rolling soon.


 
  
 Congrats I like the gold as well its more subtle than bling. What cans are you using and how are you finding it?


----------



## daltonljj

grausch said:


> The ?gold? top plate and transformer bell look really good. Care to post some more pics?


 
 her are some more pics.

  

  
  


jamiemcc said:


> Congrats I like the gold as well its more subtle than bling. What cans are you using and how are you finding it?


 
  
 As for cans i'm still waiting for my HD800. Had a go at it once and fell in love from the moment I had it on.


----------



## Loquah

I love how hand finished the top plate and bell looks - like it's been hand forged with a mold or something


----------



## daltonljj

loquah said:


> I love how hand finished the top plate and bell looks - like it's been hand forged with a mold or something


 
  
 Thanks a lot  Wanted to bring out the essence of a DIY look so I decided to use the hammered gold metal paint.
  
 Seen many threads of ppl showing off their cap upgrades. Was wondering where can I find guides teaching me to make these upgrades.  Been searching high and low for them but no where to be found.


----------



## i luvmusic 2

Wallet Killer ALERT...........


----------



## Loquah

daltonljj said:


> Thanks a lot  Wanted to bring out the essence of a DIY look so I decided to use the hammered gold metal paint.
> 
> Seen many threads of ppl showing off their cap upgrades. Was wondering where can I find guides teaching me to make these upgrades.  Been searching high and low for them but no where to be found.


 
  
 There are some good cap discussion threads over on the Bottlehead Forum under the Crack kit and S.E.X. kit sections.
  
 Otherwise, ask here and the community will no doubt help you learn - that's how I've learned so far


----------



## JamieMcC

daltonljj said:


> Thanks a lot  Wanted to bring out the essence of a DIY look so I decided to use the hammered gold metal paint.
> 
> Seen many threads of ppl showing off their cap upgrades. Was wondering where can I find guides teaching me to make these upgrades.  Been searching high and low for them but no where to be found.


 
  
 Try googling "bottlehead crack upgrade path" there was a long thread with loads of info in it alternatively a google image search of "bottlehead crack" will bring up loads of cracks with mods may be some info on the associated pages. We can also help but suspect posting on the bhf is a good place if you get stuck most of us here check in there preety regularly. Once you have firmed up some ideas basically most of the mods are just substituting one part for another so you are just a disconnecting a capacitor and replacing it with another connecting to the same terminals but using short fly leads to connect the capacitor instead of connecting directly to the terminals as the electrolytic ones are.


i luvmusic 2 said:


> Wallet Killer ALERT...........


 
  
 Please tell more?


----------



## daltonljj

jamiemcc said:


> Try googling "bottlehead crack upgrade path" there was a long thread with loads of info in it alternatively a google image search of "bottlehead crack" will bring up loads of cracks with mods may be some info on the associated pages. We can also help but suspect posting on the bhf is a good place if you get stuck most of us here check in there preety regularly. Once you have firmed up some ideas basically most of the mods are just substituting one part for another so you are just a disconnecting a capacitor and replacing it with another connecting to the same terminals but using short fly leads to connect the capacitor instead of connecting directly to the terminals as the electrolytic ones are.
> 
> Please tell more?


 
  
 I did exactly just that. Most that actually came up from the search were more of description on the upgrades that were made. Being someone who knows nuts about electric component I don't really know how to perform these upgrades on my own. Yes I can tell what the different components are and how they function and what they can be use for. However having to understanding how to connect them is beyond my level.


----------



## Angerer

Hi all, not read all posts here but I've just purchased this bad boy (awaiting arrival) to drive my HD600s and I was wondering if this would be a good upgrade from my Objective 2 Amp??
  
 Thanks all


----------



## Kyno

angerer said:


> Hi all, not read all posts here but I've just purchased this bad boy (awaiting arrival) to drive my HD600s and I was wondering if this would be a good upgrade from my Objective 2 Amp??
> 
> Thanks all


 
  
 Although it talks about the HD-650, this review should help you: http://diy.koenigs.dk/2014/03/02/bottlehead-crack-and-speedball-review/
  
 Decent against the O2 (a bit less details, but more musical), great with the Speedball on top of it. The same should more of less applies with the HD-600.


----------



## skeptic

angerer said:


> Hi all, not read all posts here but I've just purchased this bad boy (awaiting arrival) to drive my HD600s and I was wondering if this would be a good upgrade from my Objective 2 Amp??
> 
> Thanks all




A great upgrade in fact. Everything I said here about hd650s basically translates to hd600s as well. http://www.head-fi.org/t/476650/crack-bottlehead-otl/6060#post_10956797


----------



## Angerer

Cheers guys, appreciate the rapid replys.
 I'll have a read of both of those threads now.
  
 I bought the speedball too, looks like it'll be a nice addition


----------



## Angerer

Reading around and now I can't wait to receive my BHC, was thinking of using my Xonar D2X as a DAC or should I go a head a buy USB DAC?
  
 Thanks again peeps


----------



## JacobLee89

angerer said:


> Reading around and now I can't wait to receive my BHC, was thinking of using my Xonar D2X as a DAC or should I go a head a buy USB DAC?
> 
> Thanks again peeps


 
  
 Try your Xonar first as a DAC, and if you feel like something is missing then go get an external DAC. It doesn't have to be specifically USB since the D2X has a SPDIF out


----------



## Angerer

Thanks man, waiting patiently


----------



## daltonljj

So sad i bought mine slightly earlier and missed the deal. 90USD more for the speedball .... my wallet is crying


----------



## grausch

Modded my Crack a little and am attaching some pics. Full details can be found on the Bottlehead forums at http://bottlehead.com/smf/index.php?topic=6597.0.


----------



## adamaley

I see Speedball in your future.


----------



## i luvmusic 2

That's not all CAPS too.


----------



## grausch

Right now, I have some Belton tube sockets, terminal strips and cloth-covered 18awg wire incoming. Need to still order some resistors, LED and rectifiers. Then, the entire Crack will be redone. After that, I can start planning for the Speedball update and some cap replacements / bypasses.


----------



## junkers

Anyone have ideas for a hard-sided padded case for transporting Crack? Not going to anything extreme like checking it, but for things like taking it to a meetup, friend's house, relative's for the holidays, etc. What have you used?


----------



## grausch

Haven't used this for my Crack, but Pelicases are probably the best. I use them for electronics and cameras. Mind you, I used to live in a hurricane zone so it was a necessity.


----------



## ben_r_

grausch said:


> Haven't used this for my Crack, but Pelicases are probably the best. I use them for electronics and cameras. Mind you, I used to live in a hurricane zone so it was a necessity.


 

 Yep, there is literally nothing better than Pelican cases! I own many myself.


----------



## atomicbob

junkers said:


> Anyone have ideas for a hard-sided padded case for transporting Crack? Not going to anything extreme like checking it, but for things like taking it to a meetup, friend's house, relative's for the holidays, etc. What have you used?


 
 I use a LowePro Magnum 400 AW camera carry case. Extra padding and the Crack fits snuggly when all the compartmentalization dividers have been removed. Then there is a place for cables one major padded divider from the crack. This is how I transport my Crack to local head-fi meets.


----------



## RAZRr1275

Just ordered a stock Crack with Speedball with a Mullard 12AU7 and a Tung Sol 5998 from a head-fier. I'm excited to hear how it sounds with my HD650s


----------



## bigfatpaulie

razrr1275 said:


> Just ordered a stock Crack with Speedball with a Mullard 12AU7 and a Tung Sol 5998 from a head-fier. I'm excited to hear how it sounds with my HD650s


 
  
 It will sound sublime.


----------



## Doc B.

junkers said:


> Anyone have ideas for a hard-sided padded case for transporting Crack? Not going to anything extreme like checking it, but for things like taking it to a meetup, friend's house, relative's for the holidays, etc. What have you used?




A cheap alternative is the aluminum cases they sell for at Lowe's every now and then.They have dividers and foam so you can customize them to some extent. I bought three of them years ago and they are great for hauling amps, headphones and cables to meets. That said, atomicbob's setup is pretty slick.


----------



## Loquah

A local member here in Melbourne has a great ABS plastic case with pull out foam. I can't recall the brand, but in Australia and New Zealand they're stocked by Jaycar
  
 I tried to get one for the Mainline, but they're just a hair too tight to fit


----------



## Demoninja

Sorry to post this question once again because I'm sure it's been asked but I can't find anything conclusive on it. I decided to order the BHC+Speedball because of the recent deal. I'm planning on pairing these with HD 650s in the future. The question I have, of course, is which DAC to buy. 
  
 The three DACs I'm considering are the Modi, the oDAC, or the HRT Musicstreamer II+. My budget is going to be around $250 before tax so the HRT is right at the top of the budget while the Modi is at the bottom hovering around ~$100. If I decide on the oDAC I will be getting the version that also includes RCA so I believe that will cost around  $170. 
  
 I listen to a large variety of music so I would like to avoid as much coloring as possible. Given that criteria I believe the oDAC would be my best option but I'm very interested in the HRT. I am not able to find much information about that pairing though so I'm hesitant to jump on that. I believe the Modi is a fine DAC but I don't really want to purchase just the Modi. I would much prefer having the whole stack but since I already ordered the BHC that's out of the question. I would be open to getting it to save ~$70-150 dollars if there really will not be any performance boost over the other two. Anyone whose tried their BHC with these DACs want to chime in to help me finally decide once and for all?


----------



## atraf

demoninja said:


> Sorry to post this question once again because I'm sure it's been asked but I can't find anything conclusive on it. I decided to order the BHC+Speedball because of the recent deal. I'm planning on pairing these with HD 650s in the future. The question I have, of course, is which DAC to buy.
> 
> The three DACs I'm considering are the Modi, the oDAC, or the HRT Musicstreamer II+. My budget is going to be around $250 before tax so the HRT is right at the top of the budget while the Modi is at the bottom hovering around ~$100. If I decide on the oDAC I will be getting the version that also includes RCA so I believe that will cost around  $170.
> 
> I listen to a large variety of music so I would like to avoid as much coloring as possible. Given that criteria I believe the oDAC would be my best option but I'm very interested in the HRT. I am not able to find much information about that pairing though so I'm hesitant to jump on that. I believe the Modi is a fine DAC but I don't really want to purchase just the Modi. I would much prefer having the whole stack but since I already ordered the BHC that's out of the question. I would be open to getting it to save ~$70-150 dollars if there really will not be any performance boost over the other two. Anyone whose tried their BHC with these DACs want to chime in to help me finally decide once and for all?


 
 I was in the same place as you are a few weeks ago, All of the above including AQ dragonfly 1.2 were in consideration.
 I finally went with the modi and I will explain, odac is a well known dac for its brightness and neutralism, with a bright headphones it might sound harsh anyway some might like the combination of a dark/warm headphone/amp (HD650 and BHC) with a bright DAC just to even things up, to me it was the other way around, I wanted to preserve the HD650 sound signature as much as I can and just extend everything to its best, so no for the odac.
 The HRT and AQ were in consideration for their mobility, and driving my IEM's on the go, HRT is more compatible with mobile phones and the AQ suppose to have a warmer signature and got really good reviews on its DAC capabilities, After reading a quite lot I got to the conclusion that a stationary stand alone DAC will usually be better than dac/amps combos like the HRT and AQ and since the mobility is not a necessity for me I went for what's left and thats the schiit modi.
 I don't know for sure If I made the right choice since I didn't have a chance to compare them, but that modi .. I am loving it.
 First impression was WOW, it made the biggest improvement in my system, more than the SB.
 The best way I can to describe the modi effect on my system is that it just made everything POP and extend, the Bass became more punchy and deeper and the highs and mids became very clear which made vocals sound amazing.
One complaint that I have is that it doesn't support 24/192, but that's no biggy for me.
And for that price couldn't be happier.


----------



## Nic Rhodes

Modi and ODAC both work well with Bottlehead.


----------



## BlueMax

To stay within your budget, take a look at the iFi iDSD Nano. If you can stretch your budget, the iDSD Micro is pretty amazing for the price. Either way, you get a device that plays just about every resolution out there right now. I had a Nano originally, but now have a Micro feeding my BH Crack W/ SB and it's a really great combo.
  
 Good luck in your search!


----------



## nailbunny7

I'd just get a Modi or Odac and save up for something better later like the Bifrost Uber.


----------



## Loquah

nailbunny7 said:


> I'd just get a Modi or Odac and save up for something better later like the *Bifrost Uber.*


 
  
 Or the Bottlehead DAC


----------



## Aeolus Kratos

loquah said:


> Or the Bottlehead DAC


 
 Seems like someone just couldn't resist and pre-ordered a Bottlehead DAC


----------



## Loquah

Who you or me? 

I REALLY wanted to, but my upcoming wedding's getting all my funds. Maybe once we've tied the knot (and paid the bills)


----------



## jwusoccer

What would be a good budget tube to replace the 12AU7? Mine is making really loud and obnoxious buzzing noises if the amp gets moved/shaken at all.


----------



## Loquah

jwusoccer said:


> What would be a good budget tube to replace the 12AU7? Mine is making really loud and obnoxious buzzing noises if the amp gets moved/shaken at all.


 
  
 An RCA Cleartop 12AU7 is hard to go past


----------



## Doc B.

Are you sure it's the tube? It kind of sounds like a loose connection somewhere. You might want to inspect the solder joints to see if one was missed.


----------



## Loquah

doc b. said:


> Are you sure it's the tube? It kind of sounds like a loose connection somewhere. You might want to inspect the solder joints to see if one was missed.


 
  
 LOL. I went straight into the consumerism of buying new tubes and completely overlooked the cause


----------



## junkers

How spacious is the inside of the Crack? Has anyone tried to put in a small DAC inside of it?


----------



## Loquah

junkers said:


> How spacious is the inside of the Crack? Has anyone tried to put in a small DAC inside of it?


 
  
 You could easily fit a Dragonfly / ODAC / HRT Streamer, etc. although the risk of noise has been raised in these types of discussions before


----------



## gidion27

Maybe a stupid question but have a small party comming up and was wondering if I could plug in one those small "wireless" speakers using a mini to mini. Crack headphone out to line in on the speaker. 

Again sorry if it is a stupid question but generally not used to play music for anybody else


----------



## grausch

gidion27 said:


> Maybe a stupid question but have a small party comming up and was wondering if I could plug in one those small "wireless" speakers using a mini to mini. Crack headphone out to line in on the speaker.
> 
> Again sorry if it is a stupid question but generally not used to play music for anybody else


 
 I have used a cMoyBB with some cheap computer speakers to provide additional gain. They actually handled it quite well and did not distort / blow up.
  
 You run the risk of clipping if you input signal is too high, i.e. too loud, but you can always try and see if it works. Just start with the Crack at a pretty low volume.


----------



## gidion27

Sweet will give it a go. But the wireless speaker is not a cheap one. Beoplay a2 so will have to be careful that is for sure


----------



## junkers

loquah said:


> junkers said:
> 
> 
> > How spacious is the inside of the Crack? Has anyone tried to put in a small DAC inside of it?
> ...


 
 Did not realize that the Crack (or tubes in general) were so sensitive to noise).


----------



## grausch

junkers said:


> Did not realize that the Crack (or tubes in general) were so sensitive to noise).


 
 It can be. There are several wall outlets in my house where I pick up noise. This is directly related to the other devices on the circuit.
  
 However, if I use it on a clean circuit, then I have no noise whatsoever. Completely dead-silent and I am without the Speedball upgrade. No clue how much more silent the amp can get.


----------



## i luvmusic 2

Mine is DEAD QUIET anywhere i plug it yes even at work(construction site office Heavy equipment noise,power tools and  alot computer stuff ).


----------



## Loquah

Yeah. I had some noise problems with mine too. It was also due to power / WiFi noise (not sure which), but changing locations certainly helped - especially getting away from switch mode power supplies (wall warts and laptop power packs)


----------



## lextek

I've Bern lucky, no noise issues.


----------



## doublin

Hey guys, I'm new to audiophile and are planning to buy Bottlehead Crack for my soon-to-be HD600. Firstly, is there any option for a ready-assembled Crack instead of just the kit? I have zero experience on soldering and isn't planning to start now especially with Bottlehead Crack for my first. Secondly, is there a massive difference between the Crack and O2/DAC or maybe a Schiit Stack? I realize that one is tube amp and the rest are solid state but I'm no expert in audiophile and are planning to listen casually instead of doing it as a job. Those questions are probably answered before in this thread but I don't have time to skim through 400+ pages to look for the answer. Thanks.


----------



## greyhamster

doublin said:


> Hey guys, I'm new to audiophile and are planning to buy Bottlehead Crack for my soon-to-be HD600. Firstly, is there any option for a ready-assembled Crack instead of just the kit? I have zero experience on soldering and isn't planning to start now especially with Bottlehead Crack for my first. Secondly, is there a massive difference between the Crack and O2/DAC or maybe a Schiit Stack? I realize that one is tube amp and the rest are solid state but I'm no expert in audiophile and are planning to listen casually instead of doing it as a job. Those questions are probably answered before in this thread but I don't have time to skim through 400+ pages to look for the answer. Thanks.


 

 First, bottlehead offers assembling services which will cost you about $200 for the crack. To save some buck I recommend you to take a look at the for sale forums http://www.head-fi.org/f/6551/amplification-for-sale-trade
  
 Second, the difference is indeed massive, at least that's what I heard moving from schitt asgard to crack. Imo the best thing about HD600 Crack combo is you won't have to worry about upgrade your setup any time soon.


----------



## atsq17

I second that. 
  
 I've upgraded my DAC to one worth 1.4K, I'm using the Beyer T1, upgraded RCAs, USB cables, Headphone cable. 
  
 The one constant is the Crack SB. 
  
 I've owned and sold two Bakoon amps because I prefer the Crack with the T1. 
  
 Of course if I owned a low impedance planar like hifiman or audeze I would have probably kept a Bakoon amp too but since I don't, the Crack is my last amp standing.


----------



## doublin

Hmm, I guess I should buy the Crack. Just for the sake of comparison, what would be the next best tube amp aside from the Bottlehead Crack?


----------



## Loquah

atsq17 said:


> I second that.
> 
> I've upgraded my DAC to one worth 1.4K, I'm using the Beyer T1, upgraded RCAs, USB cables, Headphone cable.
> 
> ...


 
  
 That's only because you haven't bought a Mainline! 
	

	
	
		
		

		
			





 (Joking - your Crack sounds awesome with the mods you chose)


----------



## atsq17

loquah said:


> That's only because you haven't bought a Mainline!
> 
> 
> 
> ...


 
  
 Haha. Yeap, the mods you helped me choose!  
  
 I think that the Mainline is an obvious step up. However when you are at 95/100... paying double to make it 97 or 98... is exactly what this hobby is all about! Haha.
  
 I've already hit the diminishing returns point with DAC (I think my happy point was around the $800 mark). I am trying to hold out with the amp side of things until money is no longer an object to me. Then I'll be back for the Mainline!


----------



## Aeolus Kratos

doublin said:


> Hmm, I guess I should buy the Crack. Just for the sake of comparison, what would be the next best tube amp aside from the Bottlehead Crack?


 
 Easy question, if you love the sound of the specific brand, in this case it's Bottlehead, you just upgrade to the next amp of their product line.
  
 A Bottlehead S.E.X or particularly a Mainline is what you're looking for.


----------



## doublin

aeolus kratos said:


> Easy question, if you love the sound of the specific brand, in this case it's Bottlehead, you just upgrade to the next amp of their product line.
> 
> A Bottlehead S.E.X or particularly a Mainline is what you're looking for.


 
 Ah, I guess I used a word incorrectly there. I was asking what would be the SECOND best tube amp aside from the Crack.


----------



## atraf

doublin said:


> Ah, I guess I used a word incorrectly there. I was asking what would be the SECOND best tube amp aside from the Crack.


 
 I read some claiming that the WooAudio WA7\WA6 and La Figaro 339 are good candidates to out perform the crack, that price though.


----------



## JamieMcC

As an observation if I had a pound or dollar for every time I've seen a post such as I sold my Woo WA7\WA6, La Figaro 339, little dot, 02, Dark voice, Graham Slee, etc after hearing the Crack, I would now be able to afford a Bottlehead Mainline.
	

	
	
		
		

		
		
	


	



  
  
  
 Conversely if I had a pound or dollar for every time I've seen a post such as I sold my Crack to buy a Woo WA7\WA6, La Figaro, little dot, 02, Dark voice, Graham Slee, etc I would still be saving up for a Big Mac and fries


----------



## muad

Hey guys,
  
 So I just purchased the HD650 for the third time (I don't seem to like anything else), and I am looking to dip my toes into the OTL tube world. I have read through half this thread so far and I wish I had taken notes, but I was at work on my phone.
  
 Anyways I saw some posts stating the certain tube types are less microphonic and quieter compared to others. I plan on getting the speedball so I will not be buying expensive tubes. Really I just want an extra set of tubes in the event of failure and for testing purposed, if they look cool that is a bonus.
  
 1. So what is the least microphonic and most quiet intput tube?
  
 2. From the 5998, 6080 and 6as7g, which has the least microphonics and the quietest?
  
 Also, I don't want high gain if possible.
  
 Thanks


----------



## GrindingThud

I've had very good luck with 6080 with the metal mica tabs like this one:
http://www.ebay.com/itm/One-1959-Chatham-JAN-CAHG-6080-tube-Black-Plates-Top-Getters-/361109730255?pt=Vintage_Electronics_R2&hash=item5413d133cf



muad said:


> Hey guys,
> 
> So I just purchased the HD650 for the third time (I don't seem to like anything else), and I am looking to dip my toes into the OTL tube world. I have read through half this thread so far and I wish I had taken notes, but I was at work on my phone.
> 
> ...


----------



## Jmstrmbn

I don't have the speedball but I just bought a Sino 6as7g and it is completely silent.  I use it for upwards of 6 hours straight sometimes and have never heard any noise due to the tube.  Only $15


----------



## skeptic

All my JAN mil spec 6080s run dead quiet in my crack. Admittedly not quite as sexy looking as the ST shaped tubes but nice and rugged. You should be able to find Chatham, Sylvania etc for less than $10 a pop.


----------



## doublin

I'm planning to order a Crack+Speedball in a day or 2 and I'm not that familiar with how the delivery works. Basically, how long does it takes for the item to arrive? Or is it just a simple ready stock order that can be shipped as soon as I make the payment?


----------



## i luvmusic 2

You will be charged the time you ordered,I waited 4 weeks(US to Canada)No need to worry their customer service is top notch highly recommended.
  I bought the CRACK and S.E.X. from them with no issue you just need to be patience waiting for your item.


----------



## doublin

i luvmusic 2 said:


> You will be charged the time you ordered,I waited 4 weeks(US to Canada)No need to worry their customer service is top notch highly recommended.
> I bought the CRACK and S.E.X. from them with no issue you just need to be patience waiting for your item.


 
 Yeah, I just don't quite understand what the shipping status mean. What is the longest delivery time I have to wait before getting the item?


----------



## i luvmusic 2

doublin said:


> i luvmusic 2 said:
> 
> 
> > You will be charged the time you ordered,I waited 4 weeks(US to Canada)No need to worry their customer service is top notch highly recommended.
> ...


 
 I can't answer that only BH will know how long(typically i think at least 4 weeks but i could be wrong)


----------



## jbarnhardt

doublin said:


> Yeah, I just don't quite understand what the shipping status mean. What is the longest delivery time I have to wait before getting the item?


 
  
 I'm on the wait list for a Crack and I believe the "Shipping Status" page can be interpreted in a fairly straightforward manner. Look for the product you're interested in (let's say the Crack) - as of today, it says "Orders through 10/19 shipped". That means if you had ordered on (or before) October 19, your order would have shipped by now. Today it is November 17, just a little bit less than a month after Oct. 19. So, looking to the recent past for guidance, Crack kits that are ordered today would be expected to ship in about a month, which is very consistent with the guidance Bottlehead offers on the Crack product page and on the shipping status page. They are not going to give you an absolute guarantee of a specific future shipping date until the parts for your kit are in house, as it sometimes takes longer than expected to get a hold of all the bits and pieces needed, and in order to keep costs down, Bottlehead doesn't hold onto a bunch of extra inventory. If you want one, the best advice is to get your order in ASAP and you'll get it as soon as possible. Enjoy,
  
 -John


----------



## Doc B.

Thanks John, that was a very accurate description of how the process works. I see posts on the internet occasionally, to the effect of "Why does Bottlehead do business that way? He should be going to a bank and borrowing money to buy inventory so he can deliver like Amazon or Land's End." We had several competitors who operated their kit businesses that way. The key word there is had. Unfortunately you can't use the operating model of a large scale manufacturer or distributor when you are a small company filling needs for a pretty exclusive niche market. Though we don't offer hand wrought exotic materials options or 30 different paint colors, our business fits the description of a custom manufacturer a lot more than a multinational selling mass quantities of finished goods. And thus we stay with the program of putting these kits together to order. It may not be the best offering for those seeking instant gratification, but the system has been working pretty well for nearly 20 years.


----------



## Loquah

...and it's SO worth the short wait 

Especially given the endless tweaking and modding opportunities


----------



## skeptic

I hear Doc is rolling out "Bottlehead Prime" memberships in 2015.  Pricing TBD


----------



## Loquah

LOL. Shipping before you even know you want it


----------



## atomicbob

Have had my Crack for 14 months now. The wait back in Sep 2013 is now inconsequential compared to the hours of enjoyment experienced since. I have yet to install the Speedball upgrade sitting here. Too much fun rolling tubes and trying different DACs before taking that step. Today there is a bel canto RefLink driving a Ross Martin Audio DAC to the Crack. Tung-Sol 6AS7g and CBS-Hytron 12AU7. Even though I have the HD800, I am really enjoying the HD600 synergy with this combination.
  
 Putting this all in perspective, I have more cans, amps and DACs than time to evaluate all the combinations. From O2 to ZDSE, ODac to DP1, and in-between. The two most involving for me are the Crack / HD600 or HD800 and ZDSE / HD800.


----------



## jinrum8

indydieselnut said:


> Hey guys, as a former Crack owner I thought I'd let people on this thread know that I just posted some beautiful custom Crack bases and an assortment of 6AS7G and 6080 power tubes over in the FS/accessories forum.  I sold my amp a while back and these have been hanging around since then.  Cheers!


 
 I read this late. You still anything left?


----------



## mcandmar

It amazes me how well oiled BH are at this. Anybody who has put together there own project and bought parts from various suppliers, a transformer from another company, a chassis plate from another etc will find they are still collecting parts three months later.  Or the day you go to order your Mouser basket half the items are out of stock with a 17 week lead time!


----------



## Doc B.

mcandmar said:


> Or the day you go to order your Mouser basket half the items are out of stock with a 17 week lead time!


 
 Oh, don't even get the guys started about that. PB is our "Hendley the Scrounger".


----------



## kothganesh

atomicbob said:


> .;...............
> Putting this all in perspective, I have more cans, amps and DACs than time to evaluate all the combinations. From O2 to ZDSE, ODac to DP1, and in-between. The two most involving for me are the Crack / HD600 or HD800 and ZDSE / HD800.




Similar here..... HD 650 with the Crack and the ZD with the 800


----------



## Angerer

.... delete post


----------



## listen4joy

anyone have compared Vahalla 2 to crack+speedball?
  
  
 from purrin comare:

Vahalla 2 - not the Vahalla 1. probably top 1/3 of this list in terms of SQ. yes, that's how good it is. fast, clear, resolving - more than Crack. not as warm though / neutralish. does not work nearly as well with low Z or orthos. best to stick with high Z Senns or Beyers.
Crack - must have speedball upgrade for use with HD800. warm (but again tubes play role). not resolving enough to take full advantage of hd800. this is why most owners say it better with HD6XX than HD800.
  
 anyone have any experience?


----------



## MattTCG

I have both on my desk right now. I'll do a short comparison later today.


----------



## atomicbob

kothganesh said:


> Similar here..... HD 650 with the Crack and the ZD with the 800


 
 Those two amp / headphone combinations are highly addictive aren't they. The only can-amp pairings where I really don't want to stop the listening session when the allocated block of time is up.


----------



## skeptic

listen4joy said:


> anyone have compared Vahalla 2 to crack+speedball?
> 
> 
> from purrin comare:
> ...


 
  
 Matt's forthcoming impressions will obviously be of the most use to you, but what you might bear in mind, from a design standpoint, is that schiit is using global negative feedback to achieve low output impedance and (I assume) lower RIAA distortion measurements in the Valhalla - which sort of goes against the grain in so far as OTL tube amps.
  
 Bottlehead, by contrast, is committed to non-feedback designs which, although higher in output impedance, tend to sound more pleasing and natural, particularly in the highs, to many of us.
  
 To grossly oversimplify, although rarely published in the normal array of audio measurements, negative feedback introduces transient intermodulation distortion into the signal and can also cause, among other adverse effects, disproportionate high order distortions.  This is the inherent *flaw* (for lack of a better term) in all opamp based amp designs because opamps require the use of feedback to run in a linear mode.  My view/assumption is that TIM manifests most obviously as the subtle treble glare that many of us perceive when listening to the O2 - which I actually still quite like with some of my low impedance phones, but to my ears, my bottlehead stuff is just in another league in terms of sonics and enjoyability.


----------



## bigfatpaulie

skeptic said:


> "Negative feedback introduces transient intermodulation distortion into the signal and can [cause] disproportionately high order distortions."


 
  
 Can I get that on a T-shirt?


----------



## atraf

bigfatpaulie said:


> Can I get that on a T-shirt?


----------



## RAZRr1275

So now that I've had some time to get familiar with the Crack, I'm looking to drop about $230 on tubes or potentially mods (although I'd need to have someone do it for me as I have no soldering skills). I did some digging on common recommendations and came up with a list. If you have the chance I'm curious what you'd buy with the allotted money and what the general sound sig of your recommendation is. I'll list the tubes I currently have and the ones I'm considering with prices
  
 Here's what I have: Tung Sol 5998 Power tube, Raytheon 5814A, Westinghouse 12AU7A, RCA 12BH7, Tung Sol 5814WA, Phillips 5814A, Telefunken 12AU7, Siemens 12AU7, Tung Sol 12AU7, RCA Cleartop 12AU7, Mullard 12AU7, GE 12AU7 and Brimar 12AU7
  
 Here's what I'm looking at
  
 1) 12AU7 to 6SN7 Adapter - $17
  
 2) Power tube options: Bendix 6080WB - $55, Sylvania 6080WB - $18, Svetlana 6N13S - $27, Svetlana 6N5S - $20, Raytheon 6AS7 - $12, RCA 6AS7 - $29
  
 3) Driver tube options: Phillips 6189W - $13, Mazda CIFTE 12AU7 - $41, Sylvania 12BH7 - $26, Tesla ECC802S - $41, Tungsram E80CC - $50, Raytheon VT-231 - $34
  
 4) Mods? Don't know how much they'd cost
  
 Just want some opinions on what the most effective way to use the money would be - what combo of things would you get?
  
 Thanks


----------



## nailbunny7

razrr1275 said:


> So now that I've had some time to get familiar with the Crack, I'm looking to drop about $230 on tubes or potentially mods (although I'd need to have someone do it for me as I have no soldering skills). I did some digging on common recommendations and came up with a list. If you have the chance I'm curious what you'd buy with the allotted money and what the general sound sig of your recommendation is. I'll list the tubes I currently have and the ones I'm considering with prices
> 
> Here's what I have: Tung Sol 5998 Power tube, Raytheon 5814A, Westinghouse 12AU7A, RCA 12BH7, Tung Sol 5814WA, Phillips 5814A, Telefunken 12AU7, Siemens 12AU7, Tung Sol 12AU7, RCA Cleartop 12AU7, Mullard 12AU7, GE 12AU7 and Brimar 12AU7
> 
> ...


 
  
 Your tubes aren't really going to get much better (IMO) than a 5998 output tube (421A is probably better, but the prices they go for are quite high) with a 12bh7 driver tube (assuming you installed speedball), though an argument could be made for the 6SN7 w/ adaptor.
  
 Mods are easy enough. In order of my personal preference:
  
 Replacing the original potentiometer with a stepped attenuator is a good start, as it'll remove some of the little unwanted artifacts that potentiometers bring with them. If you are on a low budget, the Valab Stepped Attenuator is a good deal and can be had for about 30-35 dollars shipped, or a better one like the Goldpoint stepped attenuators can be had for about 175 shipped.
  
 My other recommendation is replacing the 270 ohm power resistor(s) (one, or both) with a choke. The Triad C-7X works perfectly here, as it has a resistance of 270 ohms. They're about 18 each on mouser (cheaper than eBay).
  
 Another good one is replacing the output caps with quality film caps. My preference is the Obbligato Film and Oil (about 100 for a pair), but it's a tight squeeze. You can also use types like Solen or Mundork MKP. They fit better, but I don't like them as much.
  
 You can also replace the last power supply capacitor, as it will have an impact as well (you can do all three if you really wanted, but you get almost the full effect by just replacing the last cap). You can use either a good motor run cap here, or something designed for audio power supplies, such as a Clarity Cap TC600 230uf cap, about 75 dollars shipped from Hificollective. The Clarity Cap is my preference, as it has a very, very small ESR of 0.9 mOhm.
  
 You could easily do the first three of these mods within your budget, so I would recommend those, considering you already have good tubes.


----------



## RAZRr1275

nailbunny7 said:


> Your tubes aren't really going to get much better (IMO) than a 5998 output tube (421A is probably better, but the prices they go for are quite high) with a 12bh7 driver tube (assuming you installed speedball), though an argument could be made for the 6SN7 w/ adaptor.
> 
> Mods are easy enough. In order of my personal preference:
> 
> ...


 
 It's speedballed but I'd have no idea what I was doing if I were to mod and don't really have the time to do it myself so I"d need to find someone to do it for me


----------



## nailbunny7

razrr1275 said:


> It's speedballed but I'd have no idea what I was doing if I were to mod and don't really have the time to do it myself so I"d need to find someone to do it for me


 
 If you have any friends who can work a drill and a soldering iron, the first three mods would only take an hour or so to do and are very straightforward. the opening needs to be slightly enlarged for the Valab stepped attenuator and a couple holes need to be made to mount the choke and the rest is just some quick soldering.


----------



## RAZRr1275

nailbunny7 said:


> If you have any friends who can work a drill and a soldering iron, the first three mods would only take an hour or so to do and are very straightforward. the opening needs to be slightly enlarged for the Valab stepped attenuator and a couple holes need to be made to mount the choke and the rest is just some quick soldering.


 
 Unfortunately I don't know anyone who does that sort of thing


----------



## JamieMcC

Some good suggestions above if you need someone to do the mods for you why not get try the E80cc or a 6sn7 with the adapter which are both personal favourites of mine. It might be a good way to go while you look for someone to undertake the mods for you.


----------



## Nic Rhodes

I am a tube roller at heart but the crack is really not the right tool here to get improvements with tubes. I would look at stepped attenuators then caps then chokes long before any tube rolling. The best upgrade is the speedball however.


----------



## lextek

nic rhodes said:


> I am a tube roller at heart but the crack is really not the right tool here to get improvements with tubes. I would look at stepped attenuators then caps then chokes long before any tube rolling. The best upgrade is the speedball however.




I agree 100%. Never found the Crack too picky with tubes.


----------



## skeptic

Depends on the headphones and the particular tubes I think.  I'd be hard pressed to differentiate between several of my JAN 6080's, but to my ears, all my 6080's do have a different presentation from my higher transconductance/lower output impedance 5998's or, for example, my one 7802.  The differences are also more apparent on my hd800's than hd650's fwiw.  Some of the 12au7's I really like on my hd650's (e.g. mullard and clear top) seem to bring out a little more treble brightness than I prefer with hd800's, whereas my amperex and tungsol 12au7's are warmer and seem a better match with hd800's.
  
 All this is relatively subtle, but I still think tube rolling can be fun and help maximize enjoyment so long as you keep it in perspective, auction snipe mostly cheap (<$20) tubes, and avoid obsessively spending a small fortune on tubes.  If your crack, speedball, mods and tubes start to approach the price of a mainline, you are doing it wrong


----------



## spacequeen7

jamiemcc said:


> Well I have lost count of how many times my finger has hovered over the buy it now button for the 12au7 to 6sn7 adapter but I finally bit the bullet and headed down the 6ns7 rabbit hole!
> 
> Its so far so good with my first purchase, a early NOS National Union 6ns7gt black glass and it is proving to be real Cracker! Pleased to report no adapter noise issues either as some have experianced.


 
 good to see you having fun with 6sn7's
 P.S.GT is one of my favorites


----------



## JamieMcC

Just in case anyone is looking for a 240V Crack 
  
http://www.head-fi.org/t/743100/bottlehead-crack
  
  
 Quote:


spacequeen7 said:


> good to see you having fun with 6sn7's
> P.S.GT is one of my favorites


 

 I'm really liking the NU and am looking for another one to make a pair ,then I'm going to give them a try in my BH Sex amp.


----------



## spacequeen7

jamiemcc said:


> I'm really liking the NU and am looking for another one to make a pair ,then I'm going to give them a try in my BH Sex amp.


 
 +1 for NU


----------



## i luvmusic 2

I made my own 6SN7 to 12AU7 adapter with a separate heater wires for external PS so i can used 8SN7/12SN7 which is less expensive than 6SN7.


----------



## jgreen16

^^ That adapter looks like something that originated from the plumbing section of the Home Depot. A MacGyver adapter!


----------



## i luvmusic 2

Yes it is not pretty but it does the job.


----------



## DannW

Hey.
 Quick silly question. GEC 6080, Mullard 6080 and Mullard 6080WA are the same tubes
	

	
	
		
		

		
			





?


----------



## mcandmar

Nope. Mullard and GEC both produced 6080's.


----------



## JamieMcC

dannw said:


> Hey.
> Quick silly question. GEC 6080, Mullard 6080 and Mullard 6080WA are the same tubes
> 
> 
> ...


 
  


mcandmar said:


> Nope. Mullard and GEC both produced 6080's.


 
  
 The GEC 6080  is the 6080 version of the legendary GEC 6as7g  brown base the plate structure is near identical the main difference being the 6080 version use’s twin top mounted halo getters and the 6as7g version has a single bottom mounted halo or cup getter.  Both versions where manufactured at the same Brook Green Works in Hammersmith. There are several versions of each while the plate structure looks to remain constant there are several differing variations of getters used only the 6as7g as far as I know came with bottom getters.
 Also branded MOV (Marconi) , Osram, Genalex (GEC)*, *Haltron?
  
 The Mullard 6080 was manufactured at several locations most commonly Hammersmith, Blackburn and Mitcham (most sought after) . Additional the same construction can also be found manufactured/branded as Valvo, Philips, Siemens, Amperex. They all seem to have ties with each other but not all of their 6080's are the same structure types as the ones manufactured in the UK that have the Mullard magic 
  
 Both are very nice sounding tubes being noticeably different in character from each other.


----------



## Bwaze

Searched the forums and reviews but haven't found much, so I have a question:
  
 Is Bottlehead Crack good match for metal and hard rock?
  
 Haven't found a thread like the one for the headphones (http://www.head-fi.org/t/715478/headphones-for-metal-music-ultimate-solution), and there's very little discussion about what music types should sound best on Bottlehead Crack, but I'm a bit worried by various reviews which describe it as "lush" and "smooth":
  


> Tube amps roll off highs. Cymbals change from a "cschh" to a "schh," adding a lushness to the sound. This is where you will notice a really laid-back feel. You definitely lose crispness here and end up with a much softer, squishier, more comfortable and non-fatiguing sound. It's great for things like soft rock and more laid-back music, but for cymbal-heavy metal you may find it lacking.


 
  
 So, anyone have experience with heavier music on Bottlehead Crack?
  
 I'm currently listening my Beyerdynamic DT 770 PRO 250 ohms with portable amp Cayin C5, and I'd like something more proper - I'm sure the headphones can be driven better. Cayin is quite clean and transparent, but if the recording demands edginess, it can be really gritty.


----------



## DannW

jamiemcc said:


> The GEC 6080  is the 6080 version of the legendary GEC 6as7g  brown base the plate structure is near identical the main difference being the 6080 version use’s twin top mounted halo getters and the 6as7g version has a single bottom mounted halo or cup getter.  Both versions where manufactured at the same Brook Green Works in Hammersmith. There are several versions of each while the plate structure looks to remain constant there are several differing variations of getters used only the 6as7g as far as I know came with bottom getters.
> Also branded MOV (Marconi) , Osram, Genalex (GEC)*, *Haltron?
> 
> The Mullard 6080 was manufactured at several locations most commonly Hammersmith, Blackburn and Mitcham (most sought after) . Additional the same construction can also be found manufactured/branded as Valvo, Philips, Siemens, Amperex. They all seem to have ties with each other but not all of their 6080's are the same structure types as the ones manufactured in the UK that have the Mullard magic
> ...


 
  Thank you for your comprehensive response.


----------



## grausch

bwaze said:


> Searched the forums and reviews but haven't found much, so I have a question:
> 
> Is Bottlehead Crack good match for metal and hard rock?
> 
> ...


 
  
 The heaviest I listen to is Iron Maiden, Megadeth (Marty Friedman years), Guns N' Roses and AC/DC. Also use the same headphones as you do. I find it handles that music quite well. Everything is in its place, however, the impact of the bass with the metal (Maiden / Megadeth) is less than that of the rock (GN'R / AC/DC). Since I have other amps as well (Soundblaster X-Fi HD USB & cmoyBB), I tested it across all of those and found the same effect with those as well. I believe it is just the way the albums get recorded that lead to these differences.
  
 All of that being said, I really enjoy listening to metal with the Crack. I would not be too worried about whether it can handle metal if I were you.
  
 Edit: Reread your post and noticed you are worried about the cymbals. I never found them missing, but I tend to listen more to guitars, bass & vocals in that order. I tend to focus on drums purely for the rhythm, so YMMV.


----------



## olegausany

bwaze said:


> Searched the forums and reviews but haven't found much, so I have a question:
> 
> Is Bottlehead Crack good match for metal and hard rock?
> 
> ...



Unfortunately never heard DT770 on Crack so can't comment on that but what definitely know that it's depends on headphones and tubes you use, I personally enjoyed metal band hard rock with HD800 and HD700 and had no problem with how cymbals sound


----------



## listen4joy

Matt  will you still do the comparison between   Vahalla 2 to crack+speedball?


----------



## MattTCG

listen4joy said:


> Matt  will you still do the comparison between   Vahalla 2 to crack+speedball?



 


Sure, here is the short version. These are my impressions and opinion. Please take it for that.

BHC w/sb:

There is no better amp out there for the hd6x00. The "pairing" and "synergy" between the BHC and the hd6x0 is simply a hypnotically engaging experience. Why? Because together you'll hear music with some of the most natural and accurate tone out there, at any price. Beautifully tight bass with impression extension. The mids are just spot on. And you'll hear inflection in the singer's voice like you would at a live performance. The highs are often misunderstood. Many describe them as veiled but with the BHC you'll hearing all the resolution in the treble that was present in the original recording. 

Valhalla 2 w/stock tubes:

This is just a fantastic full tube amp. And a very nice upgrade to the original Valhalla. The gain switch and pre-amp outs make it very versatile. The pairing is wonderful with the hd6x0. If I hadn't heard the BHC (several times) with the hd6x0 many times, this could be an end game amp for those hp's.

The Val 2 does not sound like the BHC, not even close. It really sounds like a good solid state amp with a splash of tube warmth and wetness. There is a high level of resolution and transparency here. For these reasons, while the Val 2 has to hold second candle BHC, when it comes the the hd800 the Val 2 reigns supreme. The Val 2 allows the hd800 to do what it's best at and brings out it's best attributes. 

Where the Val 2 really starts to shine is in it's versatility. While the Crack is more of a dedicated hd6x0 amp, the Val 2 works with a nice range of hp's including planar magnetic cans. This list would include the he400, he400i and pm-1 and 2. And it doesn't just suffice at pairing them, it excels. You won't do this with the Crack.

If you own or want to own the hd6x0, you owe it to yourself to also own the crack. It's own of the most magical and enjoying setups in the game.


----------



## Angerer

Hi all, can anyone spec me a DAC?
  
 I am experiencing buzz/humm interference from BHC when plugged into my Xonar D2X on pc, when connected to my Iphone the interference disapears.
  
 I purchased doubled shielded RCA cables but the buzz is still there.
  
 So I am thinking the only option here is, is to buy a usb DAC?
  
 Thanks all in advance


----------



## Loquah

There are often grounding issues with PC / USB setups. Can you try a different power point for the Crack?


----------



## atomicbob

angerer said:


> Hi all, can anyone spec me a DAC?
> 
> I am experiencing buzz/humm interference from BHC when plugged into my Xonar D2X on pc, when connected to my Iphone the interference disapears.
> 
> ...


 
 Does the hum / buzz disappear if the BHC is connected to the D2X, but the D2X is not connected to the pc (USB cable disconnected)? If so a Wyrd Decrapifier might be helpful.


----------



## Angerer

Hi there, I am connecting the BHC to D2X soundcard (which is inside PC) using RCA cables. there isn't a way for me to connect to D2X via USB.
  
 There is no buzz when connecting to my Iphone, so the interference is coming from soundcard or PC.
  
 Which leads me to ask would I be experiencing same buzz and humm from an external DAC when DAC is connected to PC via USB?
  
 Sorry if this is confusing.
  
 I appreciate any help i can get here.
  
 Cheers


----------



## atomicbob

angerer said:


> Hi there, I am connecting the BHC to D2X soundcard (which is inside PC) using RCA cables. there isn't a way for me to connect to D2X via USB.
> 
> There is no buzz when connecting to my Iphone, so the interference is coming from soundcard or PC.
> 
> ...


 
 Ah my mistake, sorry. I was thinking of the external Xonar Essence One unit. You definitely have a ground loop problem. Three DACs that I have enjoyed with the BHC are:
  
 1. Musical Fidelity V90 DAC
 2. Ross Martin Audio PCM1794 USB DAC
 3. Resonessence Labs Concero HD


----------



## olegausany

You can add Cambridge audio DacMagic plus


----------



## Angerer

Cheers for the rapid replys.
  
 Do you know if the Interference will still exist after purchasing a DAC?
  
 I will check out the DACs mentioned above. I am running my BHC with HD600s, will these DACs work well with my cans?
  
 Thanks


----------



## atomicbob

angerer said:


> Cheers for the rapid replys.
> 
> Do you know if the Interference will still exist after purchasing a DAC?
> 
> ...


 
 The three I mentioned worked best with HD600 and HD800. Just received the MF V90 DAC and am impressed at the quality of sound for a $300 DAC.


----------



## olegausany

I preferred DacMagic plus over the Bifrost uber when using HD650


----------



## atraf

angerer said:


> Cheers for the rapid replys.
> 
> Do you know if the Interference will still exist after purchasing a DAC?
> 
> ...


 
 If you want something cheaper, go with the Schiit Modi, that combo sounds amazing to my ears.
 If you do encounter more Interference issues even with a USB DAC, try to connect the DAC to self powered USB HUB it should solve it.


----------



## diaBoliQu3

Guys, my Crack got some hissing sound at the left side. Usually when I turn on the amp, it hiss only for few second than silent. However recently instead of disappear, the hissing became worst. I changed the large tube but no luck. I don't have the small tube to try with. Can faulty small tube caused this kind of issue? Or perhaps cracked soldering due to hot temp of the amp it self?


----------



## mcandmar

For all you Crack cap rollers out there, Parts connexion are selling 100uf 250v Clarity Caps 52% off, i.e. $24.95 per cap.
  
http://www.partsconnexion.com/capacitor_film_claritycap_px.html


----------



## i luvmusic 2

Awhile back i was experimenting with Bypass caps for my CRACK amp switching between some SOLEN's and some RUSSIAN caps but today on my way home from work i pass by at Parts connexion and picked up a MUNDORF caps and installed it.WOW! what  a difference the MUNDORF have more details and very smooth than all of the bypass caps i've tried so far.While the other caps they can be harsh/fatiguing when just installed but with burn-in they do smooth out the Mundorf on the other hand it's smoother sounding than those previous caps even without burn-in i just installed it and WOW! very smooth,I can't wait for this thing to properly burn-in i hope it will improve even more.The best $40 i've ever spend.


----------



## Loquah

i luvmusic 2 said:


> Awhile back i was experimenting with Bypass caps for my CRACK amp switching between some SOLEN's and some RUSSIAN caps but today on my way home from work i pass by at Parts connexion and picked up a MUNDORF caps and installed it.WOW! what  a difference the MUNDORF have more details and very smooth than all of the bypass caps i've tried so far.While the other caps they can be harsh/fatiguing when just installed but with burn-in they do smooth out the Mundorf on the other hand it's smoother sounding than those previous caps even without burn-in i just installed it and WOW! very smooth,I can't wait for this thing to properly burn-in i hope it will improve even more.The best $40 i've ever spend.


 
  
 Are these the white Mundorf M-Caps? I installed some of those for a friend and was really impressed with the results.


----------



## MattTCG

Best input tube for Crack w/sb and hd650?


----------



## i luvmusic 2

loquah said:


> i luvmusic 2 said:
> 
> 
> > Awhile back i was experimenting with Bypass caps for my CRACK amp switching between some SOLEN's and some RUSSIAN caps but today on my way home from work i pass by at Parts connexion and picked up a MUNDORF caps and installed it.WOW! what  a difference the MUNDORF have more details and very smooth than all of the bypass caps i've tried so far.While the other caps they can be harsh/fatiguing when just installed but with burn-in they do smooth out the Mundorf on the other hand it's smoother sounding than those previous caps even without burn-in i just installed it and WOW! very smooth,I can't wait for this thing to properly burn-in i hope it will improve even more.The best $40 i've ever spend.
> ...


 
 The 100uf is the white caps(old pics) and the bypass is the Black(1uf 600V).


----------



## Loquah

Ah, the Supremes are nice. I bought a set for my SEX recently


----------



## i luvmusic 2

Same here i picked up some for the SEX(0.1uf and 1.5uf) but i need to wait for my new C4S KIT then install the caps and the board at the same time,can't decide how to fit them in.


----------



## Loquah

i luvmusic 2 said:


> Same here i picked up some for the SEX(0.1uf and 1.5uf) but i need to wait for my new C4S KIT then install the caps and the board at the same time,can't decide how to fit them in.


 
  
 It's a challenge. I'm bypassing my 1.5uFs soon so will post some pics in the Bottlehead Comparison thread then if that helps at all.


----------



## i luvmusic 2

loquah said:


> i luvmusic 2 said:
> 
> 
> > Same here i picked up some for the SEX(0.1uf and 1.5uf) but i need to wait for my new C4S KIT then install the caps and the board at the same time,can't decide how to fit them in.
> ...


 
  Will not that i'am competing with you but here is my plan for the SEX amp if i'am comfortable enough to replace all the resistors i will be replacing them too(not that something is wrong with those stock resistors i just don't like how i installed them)They will be replaced with PRP,SHINKOH and TKD resistors then replace the CAPS and replace the C4S that i screwed up.There is no competitions here because clearly i can't compete with your building ability.Sure i will post some pictures as soon as i'am done so wish me luck i will need a lot of luck.


----------



## i luvmusic 2

I think i will wait until you post some pics so i have some idea how to fit those big suckers into place.


----------



## Loquah

i luvmusic 2 said:


> Will not that i'am competing with you but here is my plan for the SEX amp if i'am comfortable enough to replace all the resistors i will be replacing them too(not that something is wrong with those stock resistors i just don't like how i installed them)They will be replaced with PRP,SHINKOH and TKD resistors then replace the CAPS and replace the C4S that i screwed up.There is no competitions here because clearly i can't compete with your building ability.Sure i will post some pictures as soon as i'am done so wish me luck i will need a lot of luck.


 
  
 LOL. No competition either way - it's all about different people doing it in different ways 
	

	
	
		
		

		
			




   
 Quote:


i luvmusic 2 said:


> I think i will wait until you post some pics so i have some idea how to fit those big suckers into place.


 
  
 We should move this to the other thread as this is more of a dedicated Crack thread. Come over here for some pics of my output cap installation in the S.E.X.: http://www.head-fi.org/t/683012/bottlehead-amplifier-discussion-comparison-thread-crack-sex-mainline/930#post_11084335


----------



## JamieMcC

loquah said:


> It's a challenge. I'm bypassing my 1.5uFs soon so will post some pics in the Bottlehead Comparison thread then if that helps at all.


 
  
 The Ampohms in the Sex are working even better with the Teflon bypass really pleased with the results so far. I keep meaning to install the impedance switches but enjoying the music keeps getting in the way!


----------



## i luvmusic 2

loquah said:


> i luvmusic 2 said:
> 
> 
> > Will not that i'am competing with you but here is my plan for the SEX amp if i'am comfortable enough to replace all the resistors i will be replacing them too(not that something is wrong with those stock resistors i just don't like how i installed them)They will be replaced with PRP,SHINKOH and TKD resistors then replace the CAPS and replace the C4S that i screwed up.There is no competitions here because clearly i can't compete with your building ability.Sure i will post some pictures as soon as i'am done so wish me luck i will need a lot of luck.
> ...


 
 Yes i switched over,THANK YOU!
  


jamiemcc said:


> loquah said:
> 
> 
> > It's a challenge. I'm bypassing my 1.5uFs soon so will post some pics in the Bottlehead Comparison thread then if that helps at all.
> ...


 
 Will you should stop the music for few minutes and do the C4S,I can't listened to mine without the C4S.


----------



## MattTCG




----------



## Loquah

That's brilliant, Matt!


----------



## Angerer

Is much difference between Musical Fidelity V90 DAC and Cambridge Audio DacMagic Plus?
   
Both can be had at the same price at the minute.

  
 Using BHC and HD600s
  
 cheers


----------



## Angerer

matttcg said:


>


 
 Very nice Matt =D


----------



## MattTCG

loquah said:


> That's brilliant, Matt!


 
  
 Thanks.


----------



## Jmstrmbn

Anyone have any idea regarding Speedball shipping? Just ordered the kit on Black Friday and it notified me that the current orders were only shipped through 10/23.  I know this kinda thing is standard for Bottlehead but the 10/23 date is about 2 weeks behind other kits (most had shipped since ordered in mid Nov.).  I was hoping to get this in time for my birthday in early Jan.   
  
 Thanks everyone!
  
 John


----------



## spacequeen7

I was just browsing through some of my pics ...little refresh 
	

	
	
		
		

		
		
	


	




..year latter and still loving it ..


----------



## Angerer

spacequeen7 said:


> I was just browsing through some of my pics ...little refresh


 
 Really liking the silver RCA's, which brand are they? thanks


----------



## spacequeen7

I got them via ebay 
High-end RCA Interconnect Cable with Audiophile-grade Connectors (ra mm),can't find exact same set but this look similar 
 http://www.amazon.com/Audio-x2022-Audiophile-Rhodium-Interconnect/dp/B00L309I9A
  
 http://www.amazon.com/Audio-x2022-Audiophile-Rhodium-Interconnect/dp/B00L2TOS3I/ref=sr_1_7?s=electronics&ie=UTF8&qid=1417410002&sr=1-7


----------



## JamieMcC

spacequeen7 said:


> I was just browsing through some of my pics ...little refresh
> 
> 
> 
> ...


 
  
 How are you getting on with the Philips E80CC paired with the GEC round base its one of my favourite combinations but have only tried the E80cc that have the holes in plate sides?


----------



## Angerer

spacequeen7 said:


> I got them via ebay
> High-end RCA Interconnect Cable with Audiophile-grade Connectors (ra mm),can't find exact same set but this look similar
> http://www.amazon.com/Audio-x2022-Audiophile-Rhodium-Interconnect/dp/B00L309I9A
> 
> http://www.amazon.com/Audio-x2022-Audiophile-Rhodium-Interconnect/dp/B00L2TOS3I/ref=sr_1_7?s=electronics&ie=UTF8&qid=1417410002&sr=1-7


 

 Thanks I'll check them out =)


----------



## spacequeen7

jamiemcc said:


> How are you getting on with the Philips E80CC paired with the GEC round base its one of my favourite combinations but have only tried the E80cc that have the holes in plate sides?


 
  you nailed it E80cc Phillips or TunSol /GEC  is my favorite combo ,I also acquire  Mullard  E80cc but I still prefer Phillips most of the time ,orange globe gets a lot of action as well 
 P.S. E80cc suits crack like no other, time after time .


----------



## hotdogseller

Picked up the crack with the 15%. Hopefully will be revisiting this thread soon


----------



## Loquah

Congrats! Looking forward to seeing the finished product and reading your thoughts


----------



## jbarnhardt

jmstrmbn said:


> Anyone have any idea regarding Speedball shipping? Just ordered the kit on Black Friday and it notified me that the current orders were only shipped through 10/23.  I know this kinda thing is standard for Bottlehead but the 10/23 date is about 2 weeks behind other kits (most had shipped since ordered in mid Nov.).  I was hoping to get this in time for my birthday in early Jan.
> 
> Thanks everyone!
> 
> John


 

 May I suggest that you'll get a much more definitive answer by querying the Bottlehead folks directly rather than asking teh Internetz at large. They have always been very responsive to my e-mail questions.
  
 -John


----------



## gunnerwholelife

Guys I just scored some Amperex bugleboys on ebay.Can you please check them out and tell me if these are the same "much talked" about 12au7 bugleboys. I was just fooling around ebay and placed a cheeky bid on one of them and the seller accepted . Now I am in a dilemma of whether it will be worth it to buy them.
  
 Current tubes :-
Sylvania JAN-CHS 12au7
 Westinghouse 12au7 no: 337
 BEL 12au7 [indian tube]
 Tungsol black bottle/glass
  
  
 Links of the Amperex bugleboys  :-
 http://www.ebay.in/itm/AMPEREX-ECC82-BUGLE-BOY-HOLLAND-12AU7-PERFECT-BALANCE-SMALL-LOGO-VINTAGE-1959-/331395728784?ssPageName=ADME:L:COSI:IN:1123
  
 http://www.ebay.in/itm/AMPEREX-ECC82-HOLLAND-12AU7-K64-FOIL-GETR-LONG-PLATE-VINTAGE-1958-BUGLE-BOY-/331397907294?ssPageName=ADME:L:COSI:IN:1123
  
 Do check the above links and let me know if I should go ahead with the deal.
  
 Cheers.


----------



## jgreen16

gunnerwholelife said:


> Guys I just scored some Amperex bugleboys on ebay.Can you please check them out and tell me if these are the same "much talked" about 12au7 bugleboys. I was just fooling around ebay and placed a cheeky bid on one of them and the seller accepted . Now I am in a dilemma of whether it will be worth it to buy them.
> 
> Current tubes :-
> Sylvania JAN-CHS 12au7
> ...


 
  
 There should really be no dilemma here. You placed a bid, and it was accepted. The due diligence should have been done prior to bidding, Just my opinion on the matter.


----------



## gunnerwholelife

Quote:


jgreen16 said:


> There should really be no dilemma here. You placed a bid, and it was accepted. The due diligence should have been done prior to bidding, Just my opinion on the matter.


 
  
 True but whether to pay for them or not is completely up to me and the seller. If the seller doesn't accept my apology then I will pay for them no problem.Just clear my doubts if you can please.


----------



## MattTCG

I think that Jaygreen is referring to a matter of courtesy and respect that this may be how the seller earns his living. It's one thing to offer or simply ask a question. But to make an offer that's accepted is an agreement. 
  
 The tubes are fine according to spec and compatibility. I can't say whether they would have any issues beyond that.


----------



## mcandmar

gunnerwholelife said:


> True but whether to pay for them or not is completely up to me and the seller. If the seller doesn't accept my apology then I will pay for them no problem.Just clear my doubts if you can please.


 
  
 Don't be a dick, pay for them.  They are nice tubes, and you can always sell them again if you don't want to keep them.


----------



## atomicbob

gunnerwholelife said:


> Guys I just scored some Amperex bugleboys on ebay.Can you please check them out and tell me if these are the same "much talked" about 12au7 bugleboys. I was just fooling around ebay and placed a cheeky bid on one of them and the seller accepted . Now I am in a dilemma of whether it will be worth it to buy them.
> 
> Current tubes :-
> Sylvania JAN-CHS 12au7
> ...


 
 Hey, if you don't want them, let me buy them from the seller.


----------



## gunnerwholelife

Yeah I realized I was acting like a loser.So I just went ahead and paid for them.
Sorry @atomicbob


----------



## atomicbob

No problem. I'll find some others. Just got a Philips E80CC. Paired with a Tung Sol 6AS7g (not 5998). Wow! I had no idea.


----------



## Klots

Hello! Posted this to BH forum and will post it here too (just in case). My Crack (without speedball) has started to produce high pitch squeal (after 30mins or so warmup). When I tap the on the power tube (Tung-sol/chatham 5998) it goes quiet and then starts again. This high pitch sound does not change with volume. When I am listening to music with enough volume I cant hear the squeal, but when I put it on pause the squealing comes in. Not very loud but still it is annoying. If this is indeed faulty power tube then can it mess up my amp or is it just there to annoy me? 
	

	
	
		
		

		
			





 If anybody has any idea what to check or test or measure, then please do tell. Thanks!


----------



## saltyseaman

I know this is a very bizarre question but can I place my Crack on cardboard on the ground (very short carpet)


----------



## daltonljj

Most definitely... haha i usually put it over my head ... haha jus kidding ... imo I don't see why not ... i guess as long as the cardboard is not in direct contact with the parts that generate heat it should be fine ... haha


----------



## Loquah

Klots that sounds like it could be a dodgy solder joint at the tube socket terminals. I'd recommend reheating each terminal to reflow the solder and see if that helps.


----------



## Doc B.

Could just be dirty pins. Remove and replace the tube a couple of times, That may scrape off any contaminant.


----------



## Klots

loquah said:


> @Klots that sounds like it could be a dodgy solder joint at the tube socket terminals. I'd recommend reheating each terminal to reflow the solder and see if that helps.


 
  
  


doc b. said:


> Could just be dirty pins. Remove and replace the tube a couple of times, That may scrape off any contaminant.


 

 Did all that and nothing. Still high pitch squeal. I put my previous tube (GE 6AS7GA) into it and no squeal after 4 hours of listening. But the 5998 sounds better, only the high pitch squeal is a bit annoying. I just have to live with that squeal I guess. Made a little video with my phone so you can hear exactly what it sounds like.


----------



## atomicbob

I don't know if a tube damper would help, but it might make for a good experiment in the case of the squealing 5998.


----------



## Loquah

Maybe it's a dodgy tube?


----------



## MattTCG

Just an incredible experience...


----------



## Klots

loquah said:


> Maybe it's a dodgy tube?


 
 I think so yes. When I bought it (about 4 months ago) it was perfectly silent etc. And now a few weeks ago this squeal appeared. But I dont want to use other tubes, because I like the sound of 5998


----------



## diaBoliQu3

Guys, care to suggest input tube replacement for my old 12AU7A? I need to figure out what's wrong with my Crack which I ask previously here:
  
 http://www.head-fi.org/t/476650/crack-bottlehead-otl/6240#post_11080323
  
 Kindly help me because it's been so long I don't listen from my Crack and it cracking me up. 
  


> Guys, my Crack got some hissing sound at the left side. Usually when I turn on the amp, it hiss only for few second than silent. However recently instead of disappear, the hissing became worst. I changed the large tube but no luck. I don't have the small tube to try with. Can faulty small tube caused this kind of issue? Or perhaps cracked soldering due to hot temp of the amp it self?


----------



## atomicbob

diaboliqu3 said:


> Guys, care to suggest input tube replacement for my old 12AU7A? I need to figure out what's wrong with my Crack which I ask previously here:
> 
> http://www.head-fi.org/t/476650/crack-bottlehead-otl/6240#post_11080323
> 
> Kindly help me because it's been so long I don't listen from my Crack and it cracking me up.


 
 I'd check the solder joints on the 12AU7 tube socket first. If that isn't the issue then find a replacement 12AU7.


----------



## diaBoliQu3

atomicbob said:


> I'd check the solder joints on the 12AU7 tube socket first. If that isn't the issue then find a replacement 12AU7.


 

 Any suggestion for the replacement cum upgrade tube? Within $30 can get an upgrade or not in e-bay? I can't find suggested thread for this tube, unlike the output tube.


----------



## dsound

matttcg said:


> Just an incredible experience...


 
  
 Did you just finish this build?  Very nice, is that a Blumenstein-bamboo base?


----------



## MattTCG

dsound said:


> Did you just finish this build?  Very nice, is that a Blumenstein-bamboo base?


 
  
 I was thinking about some new caps, but...I REALLY like how this sounds just as it is. Yesterday and today I was able spend some quality time with the Crack and hd800. Wow, it sounds much better than I remember. Could be the dac though. When I had the Crack/800 last, I believe that I was using the uberfrost.


----------



## skeptic

diaboliqu3 said:


> Any suggestion for the replacement cum upgrade tube? Within $30 can get an upgrade or not in e-bay? I can't find suggested thread for this tube, unlike the output tube.


 
  
 I think basic nos Tung Sol 12au7's are very nice balanced sounding tubes.  Not too lean or too warm.  Cheap too.  For example, here's a pair for $15.  http://www.ebay.com/itm/Pair-Tung-Sol-12AU7-12AU7A-ECC82-Vacuum-Tubes-Very-Strong-/321609528392?pt=Vintage_Electronics_R2&hash=item4ae16bf448
  
 I run one of these frequently in my office rig.


----------



## JamieMcC

skeptic said:


> I think basic nos Tung Sol 12au7's are very nice balanced sounding tubes.  Not too lean or too warm.  Cheap too.  For example, here's a pair for $15.  http://www.ebay.com/itm/Pair-Tung-Sol-12AU7-12AU7A-ECC82-Vacuum-Tubes-Very-Strong-/321609528392?pt=Vintage_Electronics_R2&hash=item4ae16bf448
> 
> I run one of these frequently in my office rig.


 
  
 I like the Tung-sol as well my favourites are the 1950's 12au7 JTL or the slightly earlier 12au7 black glass, nice sounding tubes and make for a good pairing with the HD650.


----------



## diaBoliQu3

skeptic said:


> I think basic nos Tung Sol 12au7's are very nice balanced sounding tubes.  Not too lean or too warm.  Cheap too.  For example, here's a pair for $15.  http://www.ebay.com/itm/Pair-Tung-Sol-12AU7-12AU7A-ECC82-Vacuum-Tubes-Very-Strong-/321609528392?pt=Vintage_Electronics_R2&hash=item4ae16bf448
> 
> I run one of these frequently in my office rig.


 

 Wow, thank you very much and that's a nice deal. Actually, my maximum budget for input tube is $40 but $31.25 inc shipping is really a good deal for me. So, does it need to be 12AU7A, or any 12AU7, or any ECC82. Confused with tubes...
  
 Anyway, what is your main input tube? And how many Crack you own?


----------



## atomicbob

My current aural delight:


----------



## Doc B.

Nice Bob! Even the table is perfect.


----------



## Bwaze

Ordered a Bottlehead + Crack. Black Friday discount + discount due to not ordering wood base is very welcome, but I'm afraid all the savings will be put to upgrades. 
	

	
	
		
		

		
			




  
 It will be my first DIY project, and I plan to take it slowly. I'm planing to make a new top plate in polished stainless steel - I work as a designer and CNC punching machine operator (and lots of other stuff) in a company that makes professional kitchen cabinets. I still haven't decided on the sides - I could make everything in stainless steel, but I guess tube amplifiers look better with at least side wood panels.
  
 Right now I'm using Beyerdynamic DT 770 PRO, 250 ohms with portable amp Cayin C5. I think I'll upgrade the headphones to Beyerdynamic T1 if I find a good deal in a year or two, depending how much I'll like the Bottlehead Crack - I'm new to this big headphone business - always had a full size speaker system an small portable IEM headphones for phone.
  
 I read that Bottlehead got 40% more orders than they anticipated, so I guess there could be quite a long wait (and even longer for me with shipment to EU). And I already got Valab stepped attenuator today from Taiwan...


----------



## JamieMcC

bwaze said:


> Ordered a Bottlehead + Crack. Black Friday discount + discount due to not ordering wood base is very welcome, but I'm afraid all the savings will be put to upgrades.
> 
> 
> 
> ...


 
  
 Hey really pleased you managed to get your Crack order in and a great deal by the sound of it to congrats. The Valab is imo great value for the money upgrade wise. Make sure to add a few extra inches to the braided signal wire lengths and the black ground wires the Valab has the connections on the top and you will need a little bit of extra length from the cut lengths stated in the manual.
  
 The DT 770 PRO, 250 ohms worked well with my Crack and the T1 theses days offers exceptional performance for the money they seem to be getting less expensive every time I see a promotion.


----------



## JamieMcC

atomicbob said:


> My current aural delight:


 

 That looks a very civilised way to enjoy some music. Cheese and biscuits to go with the wine?


----------



## atomicbob

jamiemcc said:


> That looks a very civilised way to enjoy some music. Cheese and biscuits to go with the wine?


 
 Absolutely. That red was a Mourvedre based blend from Syncline called Subduction Red.


----------



## Tom1510

For sale my Bottlehead Crack Speedball in the sale forum.
  
 If this post is against the forum rules, I will remove it.


----------



## swmtnbiker

I'm still enjoying this sweet, sweet package of audio goodness practically every day...


----------



## muad

So I am in the process of building my crack and just painted the top plate with rustoleum hammered bronze. I tried every technique under the sun but I can't the hammered finish to appear. It comes out looking like a shiny uniform metallic bronze with pinholes in it. I tried lighter coats but that gives it a uniform textured finish. Hammered spray paint is supposed to look like the end of the below video. So anyone have any ideas? If not it's going to the powder coaters


----------



## Loquah

muad said:


> So I am in the process of building my crack and just painted the top plate with rustoleum hammered bronze. I tried every technique under the sun but I can't the hammered finish to appear. It comes out looking like a shiny uniform metallic bronze with pinholes in it. I tried lighter coats but that gives it a uniform textured finish. Hammered spray paint is supposed to look like the end of the below video. So anyone have any ideas? If not it's going to the powder coaters




  
 I believe the hammered paint is designed to go on thick which is different from other paints, but it needs the thickness for the chemical process to create the uneven finish


----------



## moriez

Hi all,
  
 If everything works out I'll be the second owner of the mighty Crack with Speedball real soon. Been wanting the amp for some time now so pretty excited!
  
 I'm wondering if it's a good OR bad idea OR at all possible, to paint the top plate without disconnecting the wiring inside and leaving it sitting in the woodbase. Would proper masktaping of everything sticking out on top and the vents be sufficient? This also goes for painting the wood. It sounds like a stupid idea to masktape the top plate and sand the base with the top plate still in place. Tremendously stupid maybe 
  
 What's your view?


----------



## Loquah

moriez said:


> Hi all,
> 
> If everything works out I'll be the second owner of the mighty Crack with Speedball real soon. Been wanting the amp for some time now so pretty excited!
> 
> ...


 
  
 It's technically possible, but I think it'll be quite a challenge to do it without it looking a bit shabby once the masking is removed, particularly around the transformer


----------



## dxanex

^ It's definitely possible, but will require a lot of masking tape, an X-ACTO knife and plenty of patience. I botched the paint job on one of my builds and decided to fix it after I was halfway done with the soldering. A bit messy, but it turned out fine.


----------



## Klots

klots said:


> Did all that and nothing. Still high pitch squeal. I put my previous tube (GE 6AS7GA) into it and no squeal after 4 hours of listening. But the 5998 sounds better, only the high pitch squeal is a bit annoying. I just have to live with that squeal I guess. Made a little video with my phone so you can hear exactly what it sounds like.
> 
> 
> 
> ...


----------



## Loquah

Still sounds like a dodgy solder joint to me. Best to reflow each joint and at the same time ensure each wire / component is securely attached. It sounds like a lot of work, but it's really not too bad.


----------



## Klots

loquah said:


> Still sounds like a dodgy solder joint to me. Best to reflow each joint and at the same time ensure each wire / component is securely attached. It sounds like a lot of work, but it's really not too bad.


 

 I have done that several times already. My film capacitors should arrive tomorrow, so I will replace electrolytics and see if anything changes. And if not I will check solder joints again. Soon I can solder crack blindfolded


----------



## Loquah

Have you done all of them, or just the ones near the noisy tube?


----------



## Klots

loquah said:


> Have you done all of them, or just the ones near the noisy tube?


 
 All of them


----------



## Loquah

Wow. That's weird then. I wonder what's causing it!?
  
 Sounds like a case to take over to the Bottlehead Forum where the experts who designed it are.


----------



## Klots

loquah said:


> Wow. That's weird then. I wonder what's causing it!?
> 
> Sounds like a case to take over to the Bottlehead Forum where the experts who designed it are.


 
 I already use both forums for it. Never know in which forum some great info jumps out.


----------



## Loquah

Very true! Hopefully someone on the BH Forum will have a solution for you


----------



## GrindingThud

Sounds like the tube is resonating for some reason, possibly loose construction in the tube. Did you say that you can hear it in the audio? This will sound weird, but I've had luck turning my WA3 on its side and let the tube get good and hot, then rap it with the eraser end of a pencil and sometimes they stop whining. Then turn it off and let it cool sideways. It's a last resort, and some will say crazy, but I've silenced a number of tubes this way.....I've also killed one. The tube might arc when you hit it, so use a pair of cheesy headphones and not your good ones.



klots said:


> I already use both forums for it. Never know in which forum some great info jumps out.


----------



## Klots

grindingthud said:


> Sounds like the tube is resonating for some reason, possibly loose construction in the tube. Did you say that you can hear it in the audio? This will sound weird, but I've had luck turning my WA3 on its side and let the tube get good and hot, then rap it with the eraser end of a pencil and sometimes they stop whining. Then turn it off and let it cool sideways. It's a last resort, and some will say crazy, but I've silenced a number of tubes this way.....I've also killed one. The tube might arc when you hit it, so use a pair of cheesy headphones and not your good ones.


 


 But if both tubes were quiet before and now both tubes have the same noise, then it can't be the tube?


----------



## GrindingThud

How many 5998 make the noise? I thought your 6AS7 was quiet.....


----------



## Klots

grindingthud said:


> How many 5998 make the noise? I thought your 6AS7 was quiet.....


 


 I thought it was quiet too, but yesterday after 1 hour of listening the noise came in. It is lower frequency than with 5998, but it is still there, and it goes quiet when tapped like with the 5998. Previously both tubes were perfectly silent. Less than a month ago that noise appeared for the first time. But if both tubes react the same, then the tube(s) should not be the cause. That squeal does not get louder with volume. I change out electrolytic caps today and see if anything changes.


----------



## GrindingThud

I have piles of bad tubes...they are very old, and many are just not up to the task of high quality audio. You might just have 2 bad tubes. It is also possible something else is wrong....but it used to work, so I suspect the tubes is it.



klots said:


> I thought it was quiet too, but yesterday after 1 hour of listening the noise came in. It is lower frequency than with 5998, but it is still there, and it goes quiet when tapped like with the 5998. Previously both tubes were perfectly silent. Less than a month ago that noise appeared for the first time. But if both tubes react the same, then the tube(s) should not be the cause. That squeal does not get louder with volume. I change out electrolytic caps today and see if anything changes.


----------



## skeptic

^Agree with GT's assessment.  I have had several power tubes do this as well - one of which was actually a very quiet tube until I fumbled it on to my hard wood floor, resulting in the hum and some loose glass in the base.  As far as short term fixes - I've had success wrapping a long thick rubber band around the base of the humming tube and then tipping it slightly in the socket at various angles until the tube runs quiet.  Real tube dampers would probably do the trick as well.


----------



## greyhamster

Now the speedball...


----------



## lextek

greyhamster said:


> Now the speedball...




Wow. Probably the neatest wiring job I've seen on a Crack.


----------



## JamieMcC

greyhamster said:


> Now the speedball...


 
  
 Very neat build. have you had the kit for some time or is it new? I noticed you have the original black output capacitors  some kits have been shipping with blue ones.


----------



## rock-solid

Hello to all Crackheads,
  
 I started to read this thread 2 months ago.
 After the first 20 pages or so I pulled the trigger and ordered one. 
 In the meantime I worked through the whole thread. Thanks to all for sharing their experiences.
 Crack is on the way - I will post pics and impressions as soon as the fun begins.
 Until now I had an Audinst HUD-MX2 as entry into my headphone experience. It was a neat all-in-one box. But the DAC-section for itself is average. Having that said and some unxepected money at hand I would like to upgrade the DAC for my Crack-experience.
 As I want to tailor the Crack for my ears the DAC should be in place before doing any mods.
 After intense research (the range of DACs today seems endless) I have an Audio-GD Reference 5.32 in focus.
 Has anybody of you paired or listened to a Crack with an Audio-GD with PCM1704 chipset?


----------



## greyhamster

jamiemcc said:


> Very neat build. have you had the kit for some time or is it new? I noticed you have the original black output capacitors  some kits have been shipping with blue ones.




I have had the kit for six months but only started building it yesterday. 


It sounds amazingly good with sennheiser hd530


----------



## Kyno

I'm joining the club, Crack + Speedball on its way 
	

	
	
		
		

		
			




  
 Now I need to see what tools I need to buy, cause I'm bare naked regarding that.


----------



## MDR30

klots said:


> I thought it was quiet too, but yesterday after 1 hour of listening the noise came in. It is lower frequency than with 5998, but it is still there, and it goes quiet when tapped like with the 5998. Previously both tubes were perfectly silent. Less than a month ago that noise appeared for the first time. But if both tubes react the same, then the tube(s) should not be the cause. That squeal does not get louder with volume. I change out electrolytic caps today and see if anything changes.




Radio interference. Dimmer, cell phone, router, wifi nearby?


----------



## Doc B.

Tube squeal is an oscillation. It is often caused by contaminants making a connection in the signal path less than perfect. So cleaning tube pins and sockets is always a good place to start. It might be worth running the amp in a configuration that allows you to move parts under the chassis while it is misbehaving to see if one particular part or connection is the cuplrit. Using a non conductive probe like a chopstick is a good way to gently push on parts to see if it helps.


----------



## head-hi

Senn HD650: $300
 http://www.focuscamera.com/sennheiser-hd650-open-aire-audiophile-grade-hi-fi-stereo-headphones.html


----------



## listen4joy

How is this solder iron for the crack?
  
 http://www.ebay.com/itm/291148382103?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT


----------



## JamieMcC

listen4joy said:


> How is this solder iron for the crack?
> 
> http://www.ebay.com/itm/291148382103?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT


 
  
 80W is more than ample, it might be to hot! Something with variable temperature can be found at a similar price
  
http://www.ebay.co.uk/itm/50-Watt-Soldering-Station-Iron-/351258230886?pt=UK_Home_Garden_PowerTools_SM&hash=item51c89f4066
  
 I have been using one of these solder stations and have been pleased with it (Maplins also sells different sized spare tips). 
  
http://www.ebay.co.uk/itm/60W-ESD-PROTECTION-LCD-SOLDERING-IRON-STATION-NEW-/201098498782?pt=UK_Home_Garden_PowerTools_SM&hash=item2ed26792de


----------



## Klots

doc b. said:


> Tube squeal is an oscillation. It is often caused by contaminants making a connection in the signal path less than perfect. So cleaning tube pins and sockets is always a good place to start. It might be worth running the amp in a configuration that allows you to move parts under the chassis while it is misbehaving to see if one particular part or connection is the cuplrit. Using a non conductive probe like a chopstick is a good way to gently push on parts to see if it helps.


 


 One small thing I discovered. When the tube is making squeal, then when I unplug the headphones and then plug them in again it goes quiet. Have tested it 5 times, and it works everytime.


----------



## rock-solid

While waiting for the Crack I put together a rough plan for finding the best setup for my ears.
 Input will be uncompressed PCM via Mac mini -> Audirvana via USB -> DAC via RCA -> Crack.
  
 1. find right place and power supply setup for minimum interferences
 2. decision for the headphone (HD 600 vs. DT 990 old vs. DT 880 old)
 3. decision for the right DAC (Audinst vs. ?)
 4. some tube-rolling (differences between tubes are less significant after speedball)
 ——-
 After that the Crack should have the right tonality for my ears.
  
 5. Speedball-upgrade
 6. VALab ladder stepped attenuator (after Speedball and tonality set up the attenuator should prove, that the stock pot was audible „in the way“ for the smaller details if it wants to stay in place)
 7. Mundorf output caps - it´s time to look for nuances in tonality and bass presentation
 8. playing around with DACs DSP-settings and oversampling
 9. optional: bypass output caps (only if get a good deal)
  
 In each step (besides 5.) a decision has to be made before going on and should be enough listening time to do so.
  
 What do you think?


----------



## Jimmy24

kyno said:


> I'm joining the club, Crack + Speedball on its way
> 
> 
> 
> ...


 
  
 I just put together my Crack/Speedball recently so I know which tools you're going to need and some tips for the process.
  
 You're going to need a couple of tools...
  
*Solder*
*Solder Wire*
*Solder Tip Cleaner*
*Very small pointed pliers* (the smaller the better to get those wires wrapped around those terminals easier)
*Very small wire clippers* (to cut wires and to remove excess wire after soldering, the smaller the better)
*Wire stripper*
*Solder sucker* (you're going to need it if you haven't soldered before)
*Screw driver for small screws*
*Helping hands* (to hold Speedball PC boards while you solder in the parts)
  
  
 Important: After you're done assembling it you're definitely going to need a *voltmeter* to make sure all the connections are good.
  
                  Also, make sure you have all the bands for your resistors, rectifiers, etc. pointed towards the proper side or it won't run properly!
  
 I would suggest practicing soldering a few times before applying it on the Crack. Just take your time, follow the directions to a T,                      and you should be good. 
  
 Good luck with your build and all the best Kyno!


----------



## daltonljj

Its a very fun experience .... having to build it up from scratch and having it to work at the end ... currently saving up to buy the mainline ... haha the joys of DIY ... haha


----------



## Loquah

The addiction of DIY, you mean 

You'll love the Mainline!


----------



## daltonljj

loquah said:


> The addiction of DIY, you mean
> 
> You'll love the Mainline!


 
  Yes the addiction of DIY. I'm a mechnical engineering student and have been since i was 17 and 7 years on i'm still enjoying it. Building things has always been a joy especially when it works. Sadly have minimal knowledge on electrical engineering. Building it up is a piece of cake when there is a manual however when it comes to custom DIY circuitry upgrades onto the crack i'm a little scared to do it unless i'm really sure what i'm doing ... haha Don't wanna blow up my amp ... haha But have been trying to do some self studying on electrical cuircuits and all. Hopefully the electrical module I will be taking next sem will provide me with more knowledge


----------



## UKToecutter

jimbo24 said:


> Also, make sure you have all the bands for your resistors, rectifiers, etc. pointed towards the proper side or it won't run properly!


 
  
 Umm, It doesn't matter which way the bands are on a resistor.
 Resistors do not have polarity


----------



## lextek

uktoecutter said:


> Umm, It doesn't matter which way the bands are on a resistor.
> Resistors do not have polarity




+1


----------



## Jimmy24

uktoecutter said:


> Umm, It doesn't matter which way the bands are on a resistor.
> Resistors do not have polarity


 
  
 Thanks, sorry for the wrong information. I was just trying to emphasize the importance of having the bands on the right side for some parts because I had to redo some of them during my project.


----------



## Loquah

Yes, the diodes, little LEDs and capacitors are important to get right


----------



## Jimmy24

I'm looking to upgrade my input tube to a Mullard ECC82/12AU7. I found one on the Tube Store for a good price but was wondering if the re-issue is identical to the original? Thanks!


----------



## Nic Rhodes

no, very different beasts.


----------



## Kyno

jimbo24 said:


> I just put together my Crack/Speedball recently so I know which tools you're going to need and some tips for the process.
> 
> You're going to need a couple of tools...
> 
> ...


 
  
 Thanks a lot for the input!
  
 It's nice considering I had most of that list from the Crack manual, but I'll be careful to go with the smallest pliers available, and also get Tip cleaners, I hadn't thought about it.
  
 I was just wondering about one thing: either to get Desoldering Braid or a Desoldering pump, or both?


----------



## JamieMcC

Some locking forceps are really handy to hold parts in position when soldering they can also be used as heat sinks when soldering delicate parts.
  
 Loads on ebay to choose from
  
http://www.ebay.co.uk/itm/Haemostatic-Pean-Forceps-Set-of-two-Straight-and-Curved-Top-QualityBritish-Brand-/141164591851?pt=UK_BOI_Medical_Lab_Equipment_Medical_Equipment_Instruments_ET&hash=item20de10baeb


----------



## Jimmy24

kyno said:


> Thanks a lot for the input!
> 
> It's nice considering I had most of that list from the Crack manual, but I'll be careful to go with the smallest pliers available, and also get Tip cleaners, I hadn't thought about it.
> 
> I was just wondering about one thing: either to get Desoldering Braid or a Desoldering pump, or both?


 
  
 Never tried the desoldering braid. The desoldering pump was a bit hard to use especially if you need to go back and fix some soldering joints later when everything starts getting crammed. It would seem that the desoldering braid would be more user-friendly. I would try both and see which one works better for you.


----------



## Loquah

Yeah. I personally can't use the braid effectively, but the pump works a treat


----------



## Jimmy24

Can anyone recommend a good input tube to match with the Chatham 6AS7G?


----------



## atomicbob

jimbo24 said:


> Can anyone recommend a good input tube to match with the Chatham 6AS7G?


 
 RCA clear top 12au7 or Tungsram e80cc.


----------



## i luvmusic 2

jimbo24 said:


> kyno said:
> 
> 
> > Thanks a lot for the input!
> ...


 
 Solder sucker/Pump works best on PCB's but for larger solders like the CRACK kit solder wick/braid works best.


----------



## Loquah

No matter how I try, I can never get solder wick / braid to work properly


----------



## Keithpgdrb

loquah said:


> No matter how I try, I can never get solder wick / braid to work properly


 

 agreed.


----------



## Daniel4IEM

My setup is MacBook Pro mostly streaming Pandora Premium > Crack > HD600
  
 Since I am not using an external DAC at the moment, I'm wondering what's the optimal volume settings on analog output from laptop vs. Crack for best SQ?


----------



## olegausany

Laptop volume should be set to the maximum


----------



## jinrum8

jimbo24 said:


> Can anyone recommend a good input tube to match with the Chatham 6AS7G?


 
  
  CBS Hytron 5814A


----------



## i luvmusic 2

loquah said:


> No matter how I try, I can never get solder wick / braid to work properly


 
 It is very simple adjust the heat of your iron(higher) or Tin the tip of your iron then put the wick on the spot you would like to unsolder put your tinned iron tip over the wick wait a few seconds until the solder start to melt then pull the wick gently without moving  your iron.If you moved the iron chances are the solder will not sipped through the wick.


----------



## Loquah

I'll give that a try. Perhaps it hasn't worked because I haven't tinned the iron in the past


----------



## i luvmusic 2

Even in high heat settings works well for me without tinning the iron let the iron and braid do the works,hope that helps.


----------



## UKToecutter

It helps if you apply some flux to the solder wick.
 Helps it suck up and travel


----------



## i luvmusic 2

uktoecutter said:


> It helps if you apply some flux to the solder wick.
> Helps it suck up and travel


 
 Never tried that,good to know.Thanks!


----------



## Jimmy24

jinrum8 said:


> CBS Hytron 5814A


 
  
 Thanks, I've heard a lot of good things about that tube. I was going to order one from Vacuumtubes.net but they are sold out. Any ideas where I can get one?
  
 Thanks!


----------



## jinrum8

I think there are some on ebay.


----------



## Jimmy24

I saw that. I just ordered a few for a good price! I got so lucky in finding them.


----------



## jinrum8

Enjoy. I really like it with the Chatham 6ASVG. Now I am waiting for the Chatham 2399 (5998) that I bought today.


----------



## Jimmy24

That's funny, I just ordered a Tung Sol 5998 instead of the Chatham 6AS7G. If you don't mind asking, where did you find the Chatham 2399? 
  
 James


----------



## Daniel4IEM

Total noobie here as just got Crack + SB build this week. First time tube amp user. Can someone please orient me the two tubes (large and small)? What does each do and where can I learn more about pros/cons of different tubes for rolling?

Paired with hd600


----------



## jinrum8

I got it from a HeadfIier. Originally it was for his TS 5998 but he said it had a hairline crack and offered me the 2399. My setup is 
 SB Crack > Halide DAC HD > T90. This setup gives me the analog (warm rich) sound I like with the correct tubes.


----------



## Jimmy24

daniel4iem said:


> Total noobie here as just got Crack + SB build this week. First time tube amp user. Can someone please orient me the two tubes (large and small)? What does each do and where can I learn more about pros/cons of different tubes for rolling?
> 
> Paired with hd600


 
  
 From what I've digested over the last couple of days searching for new tubes, each tube can offer different qualities in sound. There are a few output tubes (the bigger tube) that are already established as sounding really nice with the Crack. The best ones being the WE 421A and GEC 6AS7G, but those will run you over $200 each. A few of the input tubes (smaller tube) that are recommended are Mullard CV4003, Valvo 12au7, and CBS Hytron 5814a just to name a few. Those will range between $20 to $100. Also, some tubes sound really good together and some don't. The two tubes that are reasonably priced are Tung Sol 5998 (2nd best Output tube) and CBS Hytron 5814a (very good quality for its price) that I just recently ordered. I'm still awaiting on how it sounds. Now, I'm not expert in the vacuum tube rolling game so I cannot tell you how any of these sound, just what I've researched on to be the most popular combos. I realized tube rolling is a subjective experience so it will depend on your tastes as well and can only be determined by hearing it for yourself. Hope this helped!


----------



## Daniel4IEM

Very helpful- thanks!


----------



## Jimmy24

jinrum8 said:


> I got it from a HeadfIier. Originally it was for his TS 5998 but he said it had a hairline crack and offered me the 2399. My setup is
> SB Crack > Halide DAC HD > T90. This setup gives me the analog (warm rich) sound I like with the correct tubes.


 
  
 Very awesome. Does having a DAC dramatically give you a difference in sound? I'm still debating whether I should get one or just save my money for a new pair of headphones. I'm into getting a better soundstage so if a DAC can do that I might invest in one. How do the T90's sound in compared to HD 650's?


----------



## JamieMcC

daniel4iem said:


> Total noobie here as just got Crack + SB build this week. First time tube amp user. Can someone please orient me the two tubes (large and small)? What does each do and where can I learn more about pros/cons of different tubes for rolling?
> 
> Paired with hd600


 
  
 Here you are see link below for Nick Tams superb Multi 6080/6as7g review
  
 All you need to know about the top tier driver tube choices. A word of caution before you embark on a spending spree consider that the top tubes require a fairly decent set up to hear what they are capable of its really not much point spending big buck and listening with budget cans as they will probably not be resolving enough to benefit from the full effects of rolling such tubes. Especially if your Crack is stock (see the test set up at the bottom of the link)
  
 There are also some great budget alternatives that will get you close for a fraction of the price like the GEC and Mullard 6080  Dont discount the Russian tubes like the Svetlana  6H13C (Winged C) which can be readily found new for under $10 and are every bit as good as the RCA and Sylvania 6as7g equivalents.
  
http://the-key.enix.org/~krystal/review-tube-bottlehead.html
  
 Lots of info in the Crack tube rolling thread on the Bottlehead forum
  
 Post what cans  you use and type of music you mostly listen to and you will quickly have a few replies with different options suggested which you can research further at places like tubemaze  just type in the tube type in the search box and you will most likely find a short review or two.
  
http://www.tubemaze.info/
  
 Have fun


----------



## skeptic

I try not to think of tube rolling, cap rolling (or even dac shopping) as a linear upgrade process.  Rather, there are tons and tons of options and combos out there that can impact the sound, in subtle or not so subtle ways, which will be more or less pleasing depending on your personal preferences and your particular headphones.  Experimenting with different options is the fun part.  It isn't about getting to an end point.  Far better to have a number of tubes you enjoy and can swap in and out when you feel like a breath of fresh air.


----------



## jinrum8

jimbo24 said:


> Very awesome. Does having a DAC dramatically give you a difference in sound? I'm still debating whether I should get one or just save my money for a new pair of headphones. I'm into getting a better soundstage so if a DAC can do that I might invest in one. How do the T90's sound in compared to HD 650's?


 
 I think it depends on your source. My headphone listening is with my desktop through JRiver Media Center so the DAC makes a huge difference.
 I owned a HD650 years ago and used a Burson amp and liked it too. I love the T90 with the Crack. I cannot comment the difference with the 650 as I have not heard it with the Crack. But judging from all reviews it must be great. I am sure there others who may have both and can chime in.


----------



## Daniel4IEM

jamiemcc said:


> Here you are see link below for Nick Tams superb Multi 6080/6as7g review
> 
> All you need to know about the top tier driver tube choices. A word of caution before you embark on a spending spree consider that the top tubes require a fairly decent set up to hear what they are capable of its really not much point spending big buck and listening with budget cans as they will probably not be resolving enough to benefit from the full effects of rolling such tubes. Especially if your Crack is stock (see the test set up at the bottom of the link)
> 
> ...


 
 What a helpful post- thank you very much, Jamie. I had no idea what a wild world is tubeland. My setup is Crack+SB with HD600. No more mods beyond that.
  
 Definitely not up to go spend a ton of dough on the rarest tubes so would stick with the budget tier models, for now at least.


----------



## Daniel4IEM

skeptic said:


> I try not to think of tube rolling, cap rolling (or even dac shopping) as a linear upgrade process.  Rather, there are tons and tons of options and combos out there that can impact the sound, in subtle or not so subtle ways, which will be more or less pleasing depending on your personal preferences and your particular headphones.  Experimenting with different options is the fun part.  It isn't about getting to an end point.  Far better to have a number of tubes you enjoy and can swap in and out when you feel like a breath of fresh air.


 
 Absolutely understand what you mean. I'll take the slow road to nirvana and enjoy the ride with plenty of views along the way. Thank you for the good advice.


----------



## Jimmy24

daniel4iem said:


> Absolutely understand what you mean. I'll take the slow road to nirvana and enjoy the ride with plenty of views along the way. Thank you for the good advice.


 
  
  
 Have you built the Crack + Speedball? It was such a fun project to make. I hope you enjoy the process as much as I did.


----------



## Daniel4IEM

jimbo24 said:


> Have you built the Crack + Speedball? It was such a fun project to make. I hope you enjoy the process as much as I did.


 
 I guess I've already missed a couple of the magnificent views along the journey as I purchased a build from fellow head-fier


----------



## Jimmy24

Happy New Year everybody


----------



## RonO

HNY!  1/15 means my Crack is 3.  Works the same as day one!


----------



## Jimmy24

rono said:


> HNY!  1/15 means my Crack is 3.  Works the same as day one!


 
  
 Well happy early b-day to your Crack 
	

	
	
		
		

		
			





 Nice photo btw. I'll have to upload mine as well. How are the Tung-Sol 12au7's working for you?


----------



## Jimmy24

My completed Crack/Speedball...
  

  

  
 Hope you guys like it!
  
 James


----------



## atomicbob

Nice pictures. Welcome to the Crack Club.


----------



## RonO

jimbo24 said:


> Well happy early b-day to your Crack
> 
> 
> 
> ...


 
 Of all the new stock Russian 12AU7's, that Tung Sol 6189 is the best one to my ear.  I tried the Electro Harmonix (a little flat), JJ (too hot, peaky treble), and finally the Tung Sol.  For Hard rock, and Metal, the 6189 is an excellent tube, clean and deep extended bass. The other bonus to that tube (if you like it overall) is that it's brand new, zero microphonics, no hum or buzz.  So you can flick on the amp for 10 minutes, and not really worry about cycling your vintage tubes too much. They make more.   It pairs well with anything in the octal socket,  My stock JAN 6080, or an RCA  6as7ga, or a Russian Svetlana all sound great.  The Russian tubes together just about convert the Crack to a Marshall stack for metal. Fun stuff.


----------



## diaBoliQu3

Oh crap... Missed the deal for these pair:
 http://www.ebay.com/itm/Pair-Tung-Sol-12AU7-12AU7A-ECC82-Vacuum-Tubes-Very-Strong-/321609528392?pt=Vintage_Electronics_R2&hash=item4ae16bf448&rmvSB=true&nma=true&si=dUjiHdRDBeloa%252BQ0zXgDQGEZTlQ%253D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557
  
 Any similar deal? I couldn't find one.


----------



## jinrum8

jimbo24 said:


> From what I've digested over the last couple of days searching for new tubes, each tube can offer different qualities in sound. There are a few output tubes (the bigger tube) that are already established as sounding really nice with the Crack. The best ones being the WE 421A and GEC 6AS7G, but those will run you over $200 each. A few of the input tubes (smaller tube) that are recommended are Mullard CV4003, Valvo 12au7, and CBS Hytron 5814a just to name a few. Those will range between $20 to $100. Also, some tubes sound really good together and some don't. The two tubes that are reasonably priced are Tung Sol 5998 (2nd best Output tube) and CBS Hytron 5814a (very good quality for its price) that I just recently ordered. I'm still awaiting on how it sounds. Now, I'm not expert in the vacuum tube rolling game so I cannot tell you how any of these sound, just what I've researched on to be the most popular combos. I realized tube rolling is a subjective experience so it will depend on your tastes as well and can only be determined by hearing it for yourself. Hope this helped!


 
 I am now really enjoying the Chatham 2399 with the Mullard 4003 which I received yesterday. Awsesome! I will roll the 2399 with my CBS Hytron and others soon.


----------



## Jimmy24

jinrum8 said:


> I am now really enjoying the Chatham 2399 with the Mullard 4003 which I received yesterday. Awsesome! I will roll the 2399 with my CBS Hytron and others soon.


 
 I just received my Tung Sol 5998 yesterday but I wasn't too impressed with it with my stock 12au7 tube. It was a bit too flat to me. I'm glad you found the Mullard 4003 to your liking. I am still waiting on my CBS Hytron 5814a to come in the mail as well as some Amperex Bugle Boys 12au7's. I've always heard lots of great things about the Mullard 4003. There are quite a few variants of the 4003, which one do you have?


----------



## jinrum8

jimbo24 said:


> I just received my Tung Sol 5998 yesterday but I wasn't too impressed with it with my stock 12au7 tube. It was a bit too flat to me. I'm glad you found the Mullard 4003 to your liking. I am still waiting on my CBS Hytron 5814a to come in the mail as well as some Amperex Bugle Boys 12au7's. I've always heard lots of great things about the Mullard 4003. There are quite a few variants of the 4003, which one do you have?


 
 I got this from my brother for Xmas and he got it from ebay. Not sure which variant. On tube are the letters 000-4003 CV 4003 KODDK 85-09. Sounds great though if you like warm lush sound.


----------



## Jimmy24

Did anyone here feel like the Speedball didn't make the Crack sound that much better? When I heard the Crack w/o Speedball it sounded very good. The separation was there, songs like Gravity by John Mayer and 1234 by Feist really shined with all its acoustic instruments. I felt like that Speedball gave better separation in instruments but the sound imaging for me was more 2d than the Crack. I'm hoping this has something to do with the tubes so hopefully the sound changes when I hook up an Amerex Bugle Boy or CBS Hytron into it. Maybe I was expecting too much but I was slightly disappointed with the upgrade. Maybe I'll have to take out Speedball again and see if my opinion on it remains true.


----------



## Jimmy24

So I had another listening session tonight with my Tung Sol 5998's with the stock tube. I want to take back what I said about it sounding flat. The instrument separation and 3d imaging is all there. I guess I needed a day to really relax my ears. I think yesterday I was stressed out and doing a bunch of other things while listening to music so that probably influenced my opinion on it. I find them really amazing. I was listening to Fleetwood Mac's self-titled album and everything just sounded so good. I also tried listening to it on a lower volume and it made much more of a difference. I can't wait to roll different tubes with the 12au7's. I'm really diggin the 5998's.


----------



## JamieMcC

diaboliqu3 said:


> Oh crap... Missed the deal for these pair:
> http://www.ebay.com/itm/Pair-Tung-Sol-12AU7-12AU7A-ECC82-Vacuum-Tubes-Very-Strong-/321609528392?pt=Vintage_Electronics_R2&hash=item4ae16bf448&rmvSB=true&nma=true&si=dUjiHdRDBeloa%252BQ0zXgDQGEZTlQ%253D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557
> 
> Any similar deal? I couldn't find one.


 
  
 Here is a option for you I contacted and checked with the seller who confirmed the four brown box's with 5814A and 12au7 marked in pen are Tung-sol JTL tubes I was thinking about snapping up all four but shipping to the UK makes them to expensive for me.
  
http://www.ebay.co.uk/itm/RCA-JTL-12AU7-vacuum-tube-/301146315622?


----------



## dxanex

jimbo24 said:


> Did anyone here feel like the Speedball didn't make the Crack sound that much better? When I heard the Crack w/o Speedball it sounded very good. The separation was there, songs like Gravity by John Mayer and 1234 by Feist really shined with all its acoustic instruments. I felt like that Speedball gave better separation in instruments but the sound imaging for me was more 2d than the Crack. I'm hoping this has something to do with the tubes so hopefully the sound changes when I hook up an Amerex Bugle Boy or CBS Hytron into it. Maybe I was expecting too much but I was slightly disappointed with the upgrade. Maybe I'll have to take out Speedball again and see if my opinion on it remains true.


 

 I had both a Speedballsless Crack and a Speedball'd Crack at one time and A/Bing them using the HD 650 and HD 800 I honestly didn't hear any clear night and day differences. To me the differences were subtle at best.
 Putting in a Tung-Sol TS 5998 on the other hand and the difference was much more clear. Particularly in the low end and mids. The bass was much more detailed and controlled opening up the soundstage a bit more, and the mids were smoother and placed more forward- even in the non-Speedballed Crack the results were the same.
  
 Now I feel like it's much easier to recommend the TS 5998 as a substantial upgrade to the stock Crack, rather than the Speedball. If I did it all over again though I would skip the Speedball and go straight for the TS 5998. Of course, this is IMO and YMMV.


----------



## atomicbob

jimbo24 said:


> So I had another listening session tonight with my Tung Sol 5998's with the stock tube. I want to take back what I said about it sounding flat. The instrument separation and 3d imaging is all there. I guess I needed a day to really relax my ears. I think yesterday I was stressed out and doing a bunch of other things while listening to music so that probably influenced my opinion on it. I find them really amazing. I was listening to Fleetwood Mac's self-titled album and everything just sounded so good. I also tried listening to it on a lower volume and it made much more of a difference. I can't wait to roll different tubes with the 12au7's. I'm really diggin the 5998's.


 
 Listening at lower sound levels has three benefits:
  
 1. less listening fatigue for long sessions, lower risk for hearing threshold shifts and damage
 2. electroacoustic transducers (drivers in headphones) make smaller excursions thus remaining in a more linear range of operation
 3. amplification elements (tubes) also remain in a more linear region of operation
  
 All three add up to much lower distortion.


----------



## JamieMcC

dxanex said:


> I had both a Speedballsless Crack and a Speedball'd Crack at one time and A/Bing them using the HD 650 and HD 800 I honestly didn't hear any clear night and day differences. To me the differences were subtle at best.
> Putting in a Tung-Sol TS 5998 on the other hand and the difference was much more clear. Particularly in the low end and mids. The bass was much more detailed and controlled opening up the soundstage a bit more, and the mids were smoother and placed more forward- even in the non-Speedballed Crack the results were the same.
> 
> Now I feel like it's much easier to recommend the TS 5998 as a substantial upgrade to the stock Crack, rather than the Speedball. If I did it all over again though I would skip the Speedball and go straight for the TS 5998. Of course, this is IMO and YMMV.


 

 I have AB-ed  the two together as well and came to a similar conclusion that the superior sonic ability of the higher tier tubes some what compensates for the lack of speedball.  Certainly I would rather have a Crack without speedball compared to no Crack at all and no one should be put off by purchasing a Crack because it does not have one fitted its a easy upgrade to retro fit if the urge is felt later.
  
 There are to my mind a couple of trade offs with the speedball.
  
 This first one is a bit subjective but I will throw it out there for comment.
  
 It felt to me as if some of the raw dynamics a stock Crack has were dialled back just a fraction.
 Its well reported the effects of tube rolling can be slightly diminished (imo the effects of rolling are still easily noticeable just dialled back a fraction).
 The increase gain with the speedball fitted can make noise related problems with tubes or RF/mains interference more noticeable. These are frustrating but often easily sorted with a little time spent methodically chasing down the cause and rerouting, moving to shielded cables, optical instead of USB etc.


----------



## Doc B.

From a theoretical standpoint, without the Speedball you will see distortion occur at a lower power level than you will with the Speedball. That is to say, the tube will stay more linear to a higher power level with the Speedball. The distortion that arrives earlier in the stock configuration progresses more gradually, and allows the Crack to work somewhat like a compressor. The Speedballed Crack stays clean to a higher power level, but transitions into distortion more abruptly. 

So it may sound like the stock Crack is handling transents more gracefully. It is. However those transients are actually more clean in a Speeballed Crack, as long as the level is kept below total harmonic distortion of, say, 5-10%.


----------



## JamieMcC

Interesting Doc thanks for that clarification.


----------



## pedalhead

Just ordered a Crack today. Total newbie to DIY but hoping to have it ready for the UK meet in April 
	

	
	
		
		

		
		
	


	




 .


----------



## rock-solid

First step is done - Crack is up and running.
  

  
  

  
 All done in 3 relaxed evening sessions.
 The wooden case is only taped together as the woodwork will be done in spring (have the tools in my summer house and want to smoke the wood - too cold outside for that).
 The wiring looks a bit like spaghetti explosion because of the fly leads for the output caps and the longer input wire tor the stepped attenuator coming.
 But it passed all tests on first try and is dead silent.
 Now it´s time to burn in, especially the tubes before any critical listening.
 Of course I had a sneak preview with my old DT990 - oh Lord, that sounds promising...
 Next steps: burn in, waiting for the new DAC, play around with tubes. And listen till dawn while sleeping time reduces to the half...


----------



## bigfatpaulie

rock-solid said:


> First step is done - Crack is up and running.
> 
> 
> 
> ...


 
  
  
 Looks great!!  A bottle of Laphoraig Quarter Cask will elevate a listening system to astounding levels


----------



## JamieMcC

Nice job and a good idea to have your build all prepped up ready for your intended mods. I'm looking forward to seeing what you plan on adding next.


----------



## Jimmy24

Very clean build sir. As a newcomer myself to the Crack club, I'd like to wish you a warm welcome. Happy listening!


----------



## rock-solid

> A bottle of Laphoraig Quarter Cask will elevate a listening system to astounding levels


 
  
 I wish my ears were as good as your eyes... 
	

	
	
		
		

		
		
	


	



  


> I'm looking forward to seeing what you plan on adding next.


 
  
 That will come for sure. But it will take some time. Yesterday I just wanted listen very short if everything is ok with the crack burning. Chose a track of "TRON Legacy" and ended up in listening the whole album. Damn, that Crack is really bad... it won´t let you go to sleep... Coming from my tiny DAC-Headphoneamp-Combo thats a whole new level for me. I think I need some weeks to get used to that new stage. Before that I could not appreciate nor evaluate any mod. It will be hard as the Speedball, caps and stepped attenuator are already here but I hope I will be patient.
  


> Very clean build sir.


 
  
 Thanks. I saw some builds that look a lot cleaner with the wiring routed in right angles. But for me music is more feminin - therefore the cabling should go in nice curves. The electrons should have a nice and pleasant travelling time without turbulences before reaching my ears...
	

	
	
		
		

		
		
	


	



  
  
 Alright, think I´m gonna check very short the burn in process with the good old "Reverence" from Faithless. Just one song...


----------



## lost&confused

love my crack and hd600 so much I never come here anymore


----------



## Bwaze

Woo hoo, order finally shipped! Still have lots of time for reading on how to build this thing...


----------



## VALIENTE

lost&confused said:


> love my crack and hd600 so much I never come here anymore


 
 He is already lost and confused.


----------



## Klots

bwaze said:


> Woo hoo, order finally shipped! Still have lots of time for reading on how to build this thing...


 


 Just follow the manual (which is perfect) and make good solder joints and you will be fine 
	

	
	
		
		

		
		
	


	




 Don't overthink


----------



## Jimmy24

So I've been listening to my Crack+Speedball with my HD 650's for the past few days and I am truly astounded at how good my cans sound now. I was using the 02 + ODAC before this and they don't even compare. They're leagues apart. I'm also rolling with Tung Sol 5998's and CBS Hytron 5814a's. The sound just became so lifelike and the soundstage opened up immensely.  In particular, in recordings with just vocals and acoustic guitar, it sounds as if the artist is singing and playing in the same room with you. It's uncanny. As far as separation of instruments goes, everything is extremely clear. Each instrument sounds as if it's in its own little "zone." Even songs with 6 or 7 different instruments, you can hear them distinctly apart. I am extremely happy I built the Crack. Not only does it sound good, part of the fun is in modifying it and rolling different tubes. If you're thinking of buying the Crack, you won't regret it, it's brought new life to my music listening experience!


----------



## dxanex

jimbo24 said:


> So I've been listening to my Crack+Speedball with my HD 650's for the past few days and I am truly astounded at how good my cans sound now. I was using the 02 + ODAC before this and they don't even compare. They're leagues apart. I'm also rolling with Tung Sol 5998's and CBS Hytron 5814a's. The sound just became so lifelike and the soundstage opened up immensely.  In particular, in recordings with just vocals and acoustic guitar, it sounds as if the artist is singing and playing in the same room with you. It's uncanny. As far as separation of instruments goes, everything is extremely clear. Each instrument sounds as if it's in its own little "zone." Even songs with 6 or 7 different instruments, you can hear them distinctly apart. I am extremely happy I built the Crack. Not only does it sound good, part of the fun is in modifying it and rolling different tubes. If you're thinking of buying the Crack, you won't regret it, it's brought new life to my music listening experience!


 

 That's awesome! Happy to hear you are enjoying the Crack, it is truly a fantastic amp. As much as I love my Sonett 2, I still miss listening to the Crack sometimes, which I've never done with any other previous amp. The TS 5998 just steps it up into a whole other level. Enjoy it!


----------



## skeptic

Finally got around to installing a pair of those russian teflon bypass caps, in parallel with the obbligatos I'm running as ouput caps, and I dare say my crack is sounding better than ever.  Interested to observe how things change during the burn in process, but thanks again for the recommendation Jamie!  
  
 I also stumbled on a cheap Pico Dac in the FS forum, and the combo is making for a really delightful office setup, via hd650's.  (Although still an obvious step behind my main dac, I far prefer this pairing to the sound of my odac -> crack.)  As an incidental benefit, although the Pico needed a hub in the middle with my prior android phone, it functions flawlessly with the usb host in my iphone 6+ lightning->usb connector and doesn't pop up to power consumption error message.


----------



## lextek

I love my Crack w/Speedball. I think it is the ultimate amp for the HD600. Now these big ass output caps people are adding. What changes in the sound? I am afraid to mess with it.


----------



## Jimmy24

lextek said:


> I love my Crack w/Speedball. I think it is the ultimate amp for the HD600. Now these big ass output caps people are adding. What changes in the sound? I am afraid to mess with it.


 
  
 A lot of people say there is a good improvement in sound. How "good" that improvement is, I don't know, but my curiosity got the best of me. I'm about to install some Dayton 100uF 250V that a fellow head-fier recommended. I will make a short review once I get it installed


----------



## skeptic

lextek said:


> I love my Crack w/Speedball. I think it is the ultimate amp for the HD600. Now these big ass output caps people are adding. What changes in the sound? I am afraid to mess with it.


 
  
 Frankly, it is a very easy and fun mod, as long as your replacement caps meet the specs.  Audible improvements, to my ears, are subtle, but I find that the sound seems just a little cleaner and as though there is a little less grain.  I also found deep bass to be a little more substantial via 100uf obbligatos vs. 91uf axon's, but this is most likely due to the difference in capacitance and roll off.  
  
 That said, there is a measurable scientific basis for the objectivists out there who might be considering trying film output caps.  You can see the difference in signal dissipation factor between panny electrolytics, blackgates and the obbligatos I'm running here: http://www.diyhifisupply.com/opcart/index.php?route=product/category&path=239_179_90_99  This is one of the things that makes the crack such a steal imo.  Woo used to charge hundreds to swap in blackgates as the output caps for their OTL's (because there wasn't enough space in the chassis for film caps) - now the blackgates are basically all gone.  But even modestly priced film caps poop all over the performance of blackgates.


----------



## koalapear

Got my new setup all buttoned up! Sounds great!


----------



## Jimmy24

Nice setup and lovin the paint job! Makes me want to turn mine on and start listening. Enjoy!


----------



## i luvmusic 2

Ooops!


----------



## inXcess

Hey guys, what tubes would you consider good for rolling to partner with the HD650's?


----------



## dxanex

inxcess said:


> Hey guys, what tubes would you consider good for rolling to partner with the HD650's?


 
  
 I had a load of tubes with my Crack and if you want to pull out a lot of detail but still maintain the warmth of the HD 650 my favorite by a good margin was the Tung Sol 5998 / Tesla 12AU7 combo...it's amazing and worth the cost IMO. If you want even more detail and are willing to spend a bit more the Mazda CIFTE is a detail monster but a bit leaner than the full sound of the Tesla.
  
 If you like really smooth mids and nice full soundstage the Tung-Sol 12AU7's are no slouch and relatively inexpensive on ebay.


----------



## inXcess

Hey thanks for replying, just ordered the Tesla and am looking forward to it. I'm kind of having a hard time finding the 5998 in the UK, is there anything similar you can recommend? 
  
 Thanks! 


dxanex said:


> I had a load of tubes with my Crack and if you want to pull out a lot of detail but still maintain the warmth of the HD 650 my favorite by a good margin was the Tung Sol 5998 / Tesla 12AU7 combo...it's amazing and worth the cost IMO. If you want even more detail and are willing to spend a bit more the Mazda CIFTE is a detail monster but a bit leaner than the full sound of the Tesla.
> 
> If you like really smooth mids and nice full soundstage the Tung-Sol 12AU7's are no slouch and relatively inexpensive on ebay.


----------



## dxanex

inxcess said:


> Hey thanks for replying, just ordered the Tesla and am looking forward to it. I'm kind of having a hard time finding the 5998 in the UK, is there anything similar you can recommend?
> 
> Thanks!


 

 I've personally never heard any output tube that sounded close to as good as the Tung-Sol 5998 does in the Crack. The only other tube said to best the Tung-Sol 5998 is the GEC 6AS7G brown base, which have ridiculous mark-ups and are quite expensive. I've never heard the GEC, however.
  
 I got lucky and found some 5998's on ebay for a good price...worth checking every now and then.
  
 There is also a good thread worth reading through on tube rolling over at the Bottlehead forums-
  
 http://bottlehead.com/smf/index.php?topic=663.0


----------



## Jimmy24

inxcess said:


> Hey guys, what tubes would you consider good for rolling to partner with the HD650's?




I would highly recommend the CBS Hytron 5814a's. It's one of the best 12au7's out there. It's also inexpensive. If you check my previous review of the two tubes together (5998/5814a), everything becomes very natural and lifelike. The strongest genres are acoustic music and vocals. Sounds as if they're in the room playing with you. 

http://www.vacuumtubes.com/ has the CBS Hytron 5814a's for $25 each. Just e-mail Michael and let him know that you want to order one because I believe it's not listed on the website. You may find these on eBay but they are quite rare.

http://www.vacuumtubes.net/ has the Tung Sol 5998 for $85 each. You can get the direct link to it here: http://www.vacuumtubes.net/RES%20Audio%20pages/5998.html. I'm not sure what the shipping costs would be to the UK. I would contact them as well. That's the cheapest price that I've found on the internet. You can also get these on eBay but very rare as well.

Hope those two sites help you get what you need. 

Also, if you want to take your tubes to the next level, a fellow head-fier recommended the 7119 for the input tube. You will need to mod your crack to be able to use it, but I've heard this tube offers the most realistic/live experience for the HD 650's. Soundstage is unmatched. I am in the process of modding mine so I will let you know how that sounds in a couple weeks. 

Happy rolling!


James


----------



## Surlias

Would it be possible to add a preamp output to the Crack? Like how the Magni 2 Uber does so I can pass the audio through to my desktop speakers, since the DAC I use only has one output.
  
link to screenshot of connectors on Magni 2 Uber
  
 If possible, how difficult would it be?


----------



## nailbunny7

surlias said:


> Would it be possible to add a preamp output to the Crack? Like how the Magni 2 Uber does so I can pass the audio through to my desktop speakers, since the DAC I use only has one output.
> 
> link to screenshot of connectors on Magni 2 Uber
> 
> If possible, how difficult would it be?


 
 Yes, it's very easy to do (if I'm not mistaken). Basically you can just run a set of signal wires from the output caps into a pair of RCA jacks and that should work. Unless you want to do it the more difficult way and install a switch and a different output caps just for the preamp mode.


----------



## HolyCheese

Hi,
  
 I have lost my crack+speedball manual. Could you guys send one to me. You can PM. It would be a great help!
  
 Oh and for those who are interested. It doesn't work perfectly with the X2 unless you don't care about the bass being a bit loose. The rest of the sound is great!
 X1 seems to have a little less trouble with the bass and this amp. Don't know why tough.


----------



## bigfatpaulie

holycheese said:


> Hi,
> 
> I have lost my crack+speedball manual. Could you guys send one to me. You can PM. It would be a great help!
> 
> ...


 
  
 Why don't you contact Bottlehead?  The manual is copyright and Doc asks that it is not copied.


----------



## Jimmy24

holycheese said:


> Hi,
> 
> I have lost my crack+speedball manual. Could you guys send one to me. You can PM. It would be a great help!
> 
> ...


 
  
 You should be able to download it off your account from the Bottlehead website.


----------



## jbarnhardt

I believe


jimbo24 said:


> You should be able to download it off your account from the Bottlehead website.


 
 I believe you only get one download of each product's manual. I agree with HolyCheese - just contact Bottlehead directly and I'm sure they'll work something out for you. They've been very responsive and helpful any time I've contacted them for anything.
  
 -John


----------



## HolyCheese

Yea i have already contacted them. I just tought it would be faster this way.
  
 Can't download because I don't have an account. I ordered from massdrop at the time.
  
 Anyway I understand that you are not officially allowed to share the documents because of copyright. It would explain why I couldn't find any on bing.
 So I'll just wait for a response.


----------



## Jimmy24

Just replaced the electrolytic caps with Dayton 100uF 250V Polypropylene caps. 
  

  
  
 Now to test them out!


----------



## mcandmar

Have you insulted the wires?   They look very close to the heatsinks which will create a short if they come into contact.


----------



## Jimmy24

mcandmar said:


> Have you insulted the wires?   They look very close to the heatsinks which will create a short if they come into contact.


 
  
 I did not, although the wires are very far from the heatsinks and I everything checked out okay when I tested the voltages.


----------



## JamieMcC

The Daytons look a nice fit congrats


----------



## i luvmusic 2

I would insulate those,My S.E.X. amp shorted out because of some uninsulated resistor thought it was far enough but i mistakenly pressing down one of the caps and touched the resistor.Better be safe than sorry!


----------



## rock-solid

Short update of my crack journey:
 New DAC arrived and is breaking in nonstop since 7 days now.
 Same for the variety of tubes.
 All I can say is wow - and as things break in it even gets better and smoother.
  
 So far I like this combo most (out of the about-15€-Tubes, nothing fancy):

 Telefunken 12AU7 and G.E.C. 6080.
  
 Decision for the DAC has been done in 3 seconds - it was a night and day difference!
 Now listening through my library like I never did before.
 Before I do the next upgrade I have to come to the point that I skip a song - at the moment every single one sounds so amazing that I keep hanging on.
  
 In the meantime I made new braided and shielded power cables for the Crack and DAC:

  
 And to scjarrett87: I would feel the need to insulate those leads.


----------



## lextek

rock-solid said:


> Short update of my crack journey:
> New DAC arrived and is breaking in nonstop since 7 days now.
> Same for the variety of tubes.
> All I can say is wow - and as things break in it even gets better and smoother.
> ...



What DAC did yo udecide on?


----------



## Doc B.

Those wires are ignorant mooches.

Well, he did say insulted.


----------



## mcandmar

Oops, bit of a spellchecker malfunction there. I think everybody else understood my intention though...


----------



## rock-solid

> What DAC did yo udecide on?


 
  
 It´s an Audio-GD Reference 5.32. I am a fan of the good old PCM1704UK-Chips - in the Audio-GD there are 4 of them. Got one of the last models out there (discontinued because of the PCM1704 becoming rare) at a very good price.


----------



## Jimmy24

Dayton 100uF 250V Polypropelene Capacitor Review
  
 Headphones: HD 650's
 AMP/Tubes: Crack + Speedball w/ TS 5998 and CBS Hytron 5814a.
  
_*Wow*_.
  
 So a few months ago I upgraded my Crack with Speedball and added some Tung Sol 5998's and CBS Hytron 5814a's. From the stock Crack to the Speedball + high tier tubes I heard some good improvements but nothing that made me want to come on the site and write something about it. Upgrading the electrolytics with _Dayton 100uF 250V Polypropelene_ _Capacitors_ was a different story.
  
 Tracks: Coldplay - Politik, John Mayer - Neon
  
 The first thing I noticed is that everything sounded more natural and realistic. It's almost as if the music came closer to my ears, yet separation of instruments and 3D imagining became more distinct and lifelike. I always hear people saying they turn around when they listen to music--this was actually the first time when I felt I could turn around and see the music being played next to me. These caps took my headphones to another level. I would highly recommend the Dayton 100uF 250V Film Caps. Definitely *wowed* me to write this review.
  
 Happy listening folks!


----------



## JamieMcC

You will be adding a Teflon bypass next!


----------



## Jimmy24

jamiemcc said:


> You will be adding a Teflon bypass next!




The bypasses are def next on my list after I install the switches that would let me listen to the 12BH7A's and the 5687/7119's. Kavin keeps telling me how great the 7119's are. I get excited thinking about it.


----------



## HolyCheese

Well since I received no reply from bottlehead whatsoever  I started looking around again for the manual.
  
 If anyone else lost their manual and can't find it online I have found a torrent for the files including speedball.
 magnet:?xt=urn:btih:1446c8b4919fe5dc3287a7ac2e629cf0f32dc7ba&dn=bottlehead%20crack%20manual.7z


----------



## krikor

Posted this over at the Bottlehead forum, but figured I'd put it up here as well. Recently got my Crack with Speedball up and running - first time I've done a Bottlehead kit (can't speak highly enough of just how good these kits are in terms of instructions and guidance).
  
 Really liking the sound of this amp. I also built it with the Dayton poly output caps mentioned several posts ago and used Kimber varistrand (PBJ) for the signal wire. Still need to finish the wood base, sometime.
  
 Hmmm, now about all those tube rolling options...


----------



## Thebb

Can someone with experience with tubes comment on which would be a better tube paired with a 5998:
 - 12au7 RCA Clear Top
 -12au7 Mullard
 Thanks.


----------



## JamieMcC

thebb said:


> Can someone with experience with tubes comment on which would be a better tube paired with a 5998:
> - 12au7 RCA Clear Top
> -12au7 Mullard
> Thanks.


 
  
 Mullard pairs better imho


----------



## Jimmy24

krikor said:


> Posted this over at the Bottlehead forum, but figured I'd put it up here as well. Recently got my Crack with Speedball up and running - first time I've done a Bottlehead kit (can't speak highly enough of just how good these kits are in terms of instructions and guidance).
> 
> Really liking the sound of this amp. I also built it with the Dayton poly output caps mentioned several posts ago and used Kimber varistrand (PBJ) for the signal wire. Still need to finish the wood base, sometime.
> 
> Hmmm, now about all those tube rolling options...




Very nice build. Those daytons make the crack sound superb. Diggin the purple. I use to know someone who loved purple as well. 

Happy listening my friend


----------



## JamieMcC

krikor said:


> Posted this over at the Bottlehead forum, but figured I'd put it up here as well. Recently got my Crack with Speedball up and running - first time I've done a Bottlehead kit (can't speak highly enough of just how good these kits are in terms of instructions and guidance).
> 
> Really liking the sound of this amp. I also built it with the Dayton poly output caps mentioned several posts ago and used Kimber varistrand (PBJ) for the signal wire. Still need to finish the wood base, sometime.
> 
> Hmmm, now about all those tube rolling options...


 
  
 Interesting solution for mounting the Daytons. How are you liking the Beyers and HD650's with the Crack?


----------



## i luvmusic 2

BH CRACK and C3g.THANKS! to JamieMcC and the guys from the other thread.


----------



## diaBoliQu3

jamiemcc said:


> Here is a option for you I contacted and checked with the seller who confirmed the four brown box's with 5814A and 12au7 marked in pen are Tung-sol JTL tubes I was thinking about snapping up all four but shipping to the UK makes them to expensive for me.
> 
> http://www.ebay.co.uk/itm/RCA-JTL-12AU7-vacuum-tube-/301146315622?


 
 Hi... Thank you very much. But again I missed the deal because I'm outstation travelling for four weeks and just got out from deep forest. *facepalm. Anyway, Could you give another similar deal, or any particular keyword to search because there's too many tube with different looks.
  
 Just wondering if there's particular model or design that I should get or avoid or any Tung-Sol 12AU7 will do? I notice got grey and black color tubes.


----------



## JamieMcC

i luvmusic 2 said:


> BH CRACK and C3g.THANKS! to JamieMcC and the guys from the other thread.


 
  
 Wowzers that was quick you don't hang around.
  
 I will be waiting ages for my pcbs with the socket mounts to turn up. Questions what are the pin connectors you have on the ends of your leads you are using to connect to the 12au7 socket? I had planned to hard wire my leads to a 12au7 socket saver as I would surly one day stick a lead in the wrong pin hole. An other question I like the little box you mounted them in do you have you a link?


----------



## rovopio

is there a reason why my geographical location is blocked from bottlehead website by it's admin?
  
Block details 
Your IP: *Loading...*
URL: *http://www.bottlehead.com/store.php?crn=44&rn=442&action=show_detail*
Your Browser: Loading...
Block ID: *GEO02*
Block reason: Access from your Country was disabled by the administrator.
Time: Loading...
Server ID: *cp418*


----------



## i luvmusic 2

jamiemcc said:


> i luvmusic 2 said:
> 
> 
> > BH CRACK and C3g.THANKS! to JamieMcC and the guys from the other thread.
> ...


 
  Sorry for the late reply! I used a 18 gauge solid copper wire at the end of the leads,you can use a socket saver or use a 9 pin socket upside down and install a 18 gauge solid copper wire i've done both in the past and they work well.The box was from a local electronics refurbish store sorry no links.How i build all my adapters/converters are all in cheapest way possible it may not be the prettiest but they work well for me one adapter/converters will work in many configurations just a matter of unplugging the leads,The PCB's works similar to mine can be configured in many ways but they are a pain in the butt to mount and they are prone to noise due to the wire leads are not soldered directly to the sockets.I build my adapter this way so i can use the C3g's with my other amp this tube are not cheap that is why i did not used a 9 pin socket at the end of the leads.

  



 The adapter pictured below for Sub miniature tubes works well with the crack this one works similar to the protyping PCB's only cheaper.


----------



## moriez

I'm thinking of trying other tubes than the stock bunch and came across this new Tung-Sol 6SN7GTB. Did anyone try these yet in his Crack?


----------



## UmustBKidn

Gee-whiz question:
  
 When you guys ordered your crack, did you use the online form? Or did you just call it in?


----------



## Thebb

umustbkidn said:


> Gee-whiz question:
> 
> When you guys ordered your crack, did you use the online form? Or did you just call it in?


 
 Online


----------



## Doc B.

rovopio said:


> is there a reason why my geographical location is blocked from bottlehead website by it's admin?
> 
> 
> Block details
> ...




Unfortunately certain countries have become favorite places to set up botnets from which DDoS attacks are launched. In order to keep our site protected we have been forced to block access. Believe me, I would rather not have to do this but the other choice is no one being able to get on the site because it is constantly being attacked. There is a solution - we are happy to white list your IP address to give you access to the Bottlehead site. You can PM me your IP address and I will forward it to the site admin.


----------



## rovopio

doc b. said:


> Unfortunately certain countries have become favorite places to set up botnets from which DDoS attacks are launched. In order to keep our site protected we have been forced to block access. Believe me, I would rather not have to do this but the other choice is no one being able to get on the site because it is constantly being attacked. There is a solution - we are happy to white list your IP address to give you access to the Bottlehead site. You can PM me your IP address and I will forward it to the site admin.


 
  
 i think those countries that practice less-than-upstanding behavior are also the same countries that still uses dynamic IP adress, like mine.
 i can't give you my IP address because it will change every 24 hours. Is it possible for the site admin to whitelist an ISP instead?


----------



## Doc B.

umustbkidn said:


> Gee-whiz question:
> 
> When you guys ordered your crack, did you use the online form? Or did you just call it in?




We're happy to take your call and answer any questions you may have about kits or delivery times. From a standpoint of accuracy it's actually best to be inputting your billing and shipping info yourself by ordering online. We go to extremes to insure the security of your information when ordering online. When you order online we never even see your credit card info, only the merchant service receives that data. I find it kind of funny that some customers still call us with the idea that their data will be protected if they give us the credit card info over the phone rather than filling in the fields on a computer screen. I mean, how do they think _we_ get the info to the merchant service?


----------



## Doc B.

rovopio said:


> i think those countries that practice less-than-upstanding behavior are also the same countries that still uses dynamic IP adress, like mine.
> i can't give you my IP address because it will change every 24 hours. Is it possible for the site admin to whitelist an ISP instead?




In conversations I have had regarding this it's not really clear if it's the "country" that is initiating the attacks (which is what we terrified Americans are taught by our government and media, because apparently we love to be terrified), or simply that it's easier to set up botnets in certain countries because there is not enough encouragement to use antivirus software to block the viruses that put your computer on a botnet. I will ask my site admin if it is possible to whitelist a provider. One suggestion - I am not knowledgeable enough to be sure this would be helpful - is maybe to use a VPN.


----------



## cspirou

Has anyone experimented with this amp with a 7236 or 6528 tube and used low impedance headphones like Grados? I am sure it's been done but it's hard to find comments from people that have done it.


----------



## krikor

jamiemcc said:


> Interesting solution for mounting the Daytons. How are you liking the Beyers and HD650's with the Crack?


 
  
 HD650 - I really enjoy the HD650/Crack combination. I think this is the first time I've had my HD650s properly amped and they sound fantastic. Very smooth, warm and full sound but with nicely detailed highs. Slightly darker (or veiled as some might describe it) compared to the Beyers? Yes, but much more natural and easy to listen to for long periods (too bad the comfort is not quite up to the Beyer level).
  
 DT880-600 - There are things these do really well, like the clean and open top end and great soundstage which gives them more excitement than the HD650. But the bass strikes me as just a bit too lean and controlled, which has a tendency to push them towards the bright/harsh end of the spectrum. However, they sound the best I've heard them with the Crack which gives them a bit more bass and warmth (NOTE: mine are fairly new and may still need considerable break in).
  
 DT990-600 - Only briefly listened to these on the Crack so far, but the bass struck me as way too emphasized. Yeah, these cans are known to have a U-shaped FR and that seems to really come through on the Crack. Bass way too in my face and top end somewhat confused compared to the DT880. On some other amps, I've actually preferred these to the DT880.
  
 So far I find myself going back and forth between the HD650 and DT880 depending upon mood, music, etc. But any further listening will have to wait as I've disassembled the Crack to stain and finish the wood base.


----------



## skeptic

cspirou said:


> Has anyone experimented with this amp with a 7236 or 6528 tube and used low impedance headphones like Grados? I am sure it's been done but it's hard to find comments from people that have done it.


 
  
 For giggles, I tried some low ohm audio technica's and had a 5998 (same output imp. as 7236) in at the time.  The results were....not good, particularly in comparison to how great the amp sounds with high ohm phones.  If you want to drive low impedance phones with a bh kit, go with a s.e.x. or mainline.


----------



## cspirou

skeptic said:


> For giggles, I tried some low ohm audio technica's and had a 5998 (same output imp. as 7236) in at the time.  The results were....not good, particularly in comparison to how great the amp sounds with high ohm phones.  If you want to drive low impedance phones with a bh kit, go with a s.e.x. or mainline.


 

 Thanks for the comment. I know that the standard response to this inquiry is to get the S.E.X. or Mainline, as is repeated on the BH forums. However there are many 6080 amps and some of those specify that they work down to 32 ohms. Given the DIY nature of the Crack and the fact that they encourage modding, there should be a way to mod the circuit to make 32 ohm headphones an acceptable option. If Woo Audio can do it with the WA3 and Pete Millett can do it with the Apex Teton, than it isn't a stretch to think that it's possible for the Crack to do this.
  
 Or is any modification that accommodates low impedance headphones adversely affect the way the high impedance headphones sound and therefore is considered unacceptable?


----------



## skeptic

cspirou said:


> Thanks for the comment. I know that the standard response to this inquiry is to get the S.E.X. or Mainline, as is repeated on the BH forums. However there are many 6080 amps and some of those specify that they work down to 32 ohms. Given the DIY nature of the Crack and the fact that they encourage modding, there should be a way to mod the circuit to make 32 ohm headphones an acceptable option. If Woo Audio can do it with the WA3 and Pete Millett can do it with the Apex Teton, than it isn't a stretch to think that it's possible for the Crack to do this.
> 
> Or is any modification that accommodates low impedance headphones adversely affect the way the high impedance headphones sound and therefore is considered unacceptable?


 
  
 The common method used to drop an OTL amp's output impedance is to apply negative global feedback to the circuit (or to add more tubes).  As I understand it (i.e. in overly simplistic terms), the problem with the feedback approach is that it does change the character of the sound and creates its own issues, like transient intermodulation distortion ("TIM").  (For reference, heavy use of negative feedback is how the o2 and similar chip amps hit their target measurements, but many (arguably most) ears don't ultimately find this sort of amp produces the best sound, when compared to other designs, because of TIM, possible oscillations and issues with disproportionate high order distortion.)
  
 Bottlehead makes only non-feedback amps that avoid these issues and sound awesome when paired with the phones they are intended to drive.  The trade off is that you have to have go with a kit with output transformers, which add to the cost, if you want to drive low ohm phones.  
  
 Also, FWIW, I owned the original WA3 for many years (sold after building and comparing to my crack) and can tell you that it did not play nicely (to my ears) with low ohm phones.  Maybe Woo has since added feedback to the circuit notwithstanding the downsides of doing so?  
  
 Here's Pete Millet's explanation of what's going on in the Teton.  His comments about how the IEM circuit works are over my head.  
  


> The Teton has a highish output impedance similar to the original HA-2.  The Zout depends on what output tube you use...if I recall correctly it's around 100 ohms using a 6080, and as low as 50 ohms using a 6528.
> 
> Of course, the output impedance affects the sound, depending on what headphones you use.
> 
> ...


----------



## atomicbob

cspirou said:


> Thanks for the comment. I know that the standard response to this inquiry is to get the S.E.X. or Mainline, as is repeated on the BH forums. However there are many 6080 amps and some of those specify that they work down to 32 ohms. Given the DIY nature of the Crack and the fact that they encourage modding, there should be a way to mod the circuit to make 32 ohm headphones an acceptable option. If Woo Audio can do it with the WA3 and Pete Millett can do it with the Apex Teton, than it isn't a stretch to think that it's possible for the Crack to do this.
> 
> Or is any modification that accommodates low impedance headphones adversely affect the way the high impedance headphones sound and therefore is considered unacceptable?


 
 I have both the Crack and WA3+. Both use the 6080 as a cathode follower without NFB. Output circuit topology is identical. Component values differ a little. Those differences:
  
 1. Voltage across 6080; WA3+ 119V, Crack 70V
 2. Cathode resistor; WA3+ 1K5, Crack 3K
 3. Output capacitor; WA3+ 470uF, Crack 100 uF
 4. Output resistor shunt; WA3+ 10K, Crack 2K5
 5. approx 33 ~ 35 mA current through the 6080 in both
  
 I tried lower impedance (<100 ohms) headphones with the WA+ as well as the Crack. They did not perform their best in either. Lower impedance cans were better served by my V200 or ZDSE.


----------



## GrindingThud

Nice data/comparison. The higher mu tubes also help reduce output impedance quite a bit (5998/7236).
In my WA3, the PS sits around 190V depending on the tube. What I did notice was substantially different operating points in my amp when these biased up in the circuit...which I found interesting based on comments people make on how the different tubes "sound". The 6080 and 6N13S biased up around 38mA with 57V on the cathode resistor. 5998A and 7236 settled around 21mA with 32V on the cathode resistor. The 5998 is at the other extreme with only 18.6mA current and 28V on the cathode resistor. Impressions of tubes 'sound' is somewhat dependent on where on the curve its operating. I used the CCS approach to double the current in the 5998 to get it up higher on the curve....sounds better to me, and as many agree in this forum that speedball improves sound.
From a 32ohms perspective...gotta keep the output cap big (470 or bigger) to keep the low end frequency response from rolling off too much.



atomicbob said:


> I have both the Crack and WA3+. Both use the 6080 as a cathode follower without NFB. Output circuit topology is identical. Component values differ a little. Those differences:
> 
> 1. Voltage across 6080; WA3+ 119V, Crack 70V
> 2. Cathode resistor; WA3+ 1K5, Crack 3K
> ...


----------



## cspirou

Thanks everyone, thus is really good information. Although I have no clue what Pete Millet means by a 'resistive alternator'.


----------



## atomicbob

grindingthud said:


> *edit*





> What I did notice was substantially different operating points in my amp when these biased up in the circuit...which I found interesting based on comments people make on how the different tubes "sound". The 6080 and 6N13S biased up around 38mA with 57V on the cathode resistor. 5998A and 7236 settled around 21mA with 32V on the cathode resistor. The 5998 is at the other extreme with only 18.6mA current and 28V on the cathode resistor. Impressions of tubes 'sound' is somewhat dependent on where on the curve its operating.





> *edit*


 
 I've often wondered about this. If each of the tubes were biased in such a way as to put them into the same operating point on their respective curves, I wonder if the sonic differences would converge to something more similar than different? Conversely, re-bias the same tube into different operating points to achieve the audible variances described around the internet?

 Do (or did before mods) you hear a residual hum with the WA3 if the room was very quiet and listening to say either HD600/800 or T1/T90 cans? I had a little in mine before I added an additional 10K resistor to the shunt such that the hum was reduced below my hearing threshold. It didn't go away as measured with the lab mic / preamp and measurement system. I often wonder if twisting the leads for the filament supply to the 6DJ8 would have resolved this.


----------



## GrindingThud

Yes, the amp has some hum that can be reduced by twisting the filament supplies and floating it with a pair of resistors split to ground, rather than grounding one side. No hum even with earbuds now. http://www.head-fi.org/t/94853/woo3-modified/225#post_9269260
I put a lot of the great ideas from the crack into my WA3. 



atomicbob said:


> I've often wondered about this. If each of the tubes were biased in such a
> way as to put them into the same operating point on their respective curves, I wonder if the sonic differences would converge to something more similar than different? Conversely, re-bias the same tube into different operating points to achieve the audible variances described around the internet?
> 
> 
> Do (or did before mods) you hear a residual hum with the WA3 if the room was very quiet and listening to say either HD600/800 or T1/T90 cans? I had a little in mine before I added an additional 10K resistor to the shunt such that the hum was reduced below my hearing threshold. It didn't go away as measured with the lab mic / preamp and measurement system. I often wonder if twisting the leads for the filament supply to the 6DJ8 would have resolved this.


----------



## atomicbob

grindingthud said:


> Yes, the amp has some hum that can be reduced by twisting the filament supplies and floating it with a pair of resistors split to ground, rather than grounding one side. No hum even with earbuds now. http://www.head-fi.org/t/94853/woo3-modified/225#post_9269260
> I put a lot of the great ideas from the crack into my WA3.


 
 Excellent! thank-you!


----------



## Jimmy24

Finally got around to taking some pictures of my 7119's. 
	

	
	
		
		

		
			




  

  

  
 12AU7/12BH7/5687/7119 Switches


----------



## Guizan

Going from the O2 to the Crack+Speedball would be benneficial in what ways? Or maybe what kind of differences can I expect? Never heard a tube amp (guitar amp, yes). I'd like to try something new, but I'm not sure if the law of diminishing returns is applicable here.


----------



## atsq17

guizan said:


> Going from the O2 to the Crack+Speedball would be benneficial in what ways? Or maybe what kind of differences can I expect? Never heard a tube amp (guitar amp, yes). I'd like to try something new, but I'm not sure if the law of diminishing returns is applicable here.




I think you will be pleasantly surprised at how tangible the differences are assuming you have a high impedance headphone. I know several who have moved to Crack from o2 and it's like seeing the world in a small 2d screen to a large 3d one. Don't know if that's a good analogy but is very noticeable and i think the returns are very worthwhile.


----------



## atsq17

jimbo24 said:


> Very awesome. Does having a DAC dramatically give you a difference in sound? I'm still debating whether I should get one or just save my money for a new pair of headphones. I'm into getting a better soundstage so if a DAC can do that I might invest in one. How do the T90's sound in compared to HD 650's?




If you have a hd650 stick with it for now. Grab yourself an audio gd nfb 3 2014. Then enjoy the extra clarity details and Soundstage


----------



## jinrum8

guizan said:


> Going from the O2 to the Crack+Speedball would be benneficial in what ways? Or maybe what kind of differences can I expect? Never heard a tube amp (guitar amp, yes). I'd like to try something new, but I'm not sure if the law of diminishing returns is applicable here.


 
 The review/comments here seems to give some comparison http://www.reddit.com/r/headphones/comments/1gkfaq/


----------



## Jimmy24

Atsq is right. Upgrading from the O2 to the Crack will really open up your headphones significantly. There's much more air between instruments, sound stage improved, and you'll hear details that you never heard from the O2. 


atsq17 said:


> If you have a hd650 stick with it for now. Grab yourself an audio gd nfb 3 2014. Then enjoy the extra clarity details and Soundstage


 
  
 I have not heard of that DAC before but will consider it when I purchase one. I mainly heard great reviews from the Schiit Bifrost for the Crack. Any noticeable differences between the two DAC's?


----------



## Guizan

atsq17 said:


> I think you will be pleasantly surprised at how tangible the differences are assuming you have a high impedance headphone. I know several who have moved to Crack from o2 and it's like seeing the world in a small 2d screen to a large 3d one. Don't know if that's a good analogy but is very noticeable and i think the returns are very worthwhile.


 

 I am primarily using an HD650. That would be a nice upgrade if that is the case... I definitely feel the HD650 has more potential to grow, although it sounds very solid with the current setup.


----------



## Guizan

jimbo24 said:


> Atsq is right. Upgrading from the O2 to the Crack will really open up your headphones significantly. There's much more air between instruments, sound stage improved, and you'll hear details that you never heard from the O2.
> 
> I have not heard of that DAC before but will consider it when I purchase one. I mainly heard great reviews from the Schiit Bifrost for the Crack. Any noticeable differences between the two DAC's?


 

 Thanks for that!


----------



## atsq17

jimbo24 said:


> Atsq is right. Upgrading from the O2 to the Crack will really open up your headphones significantly. There's much more air between instruments, sound stage improved, and you'll hear details that you never heard from the O2.
> 
> I have not heard of that DAC before but will consider it when I purchase one. I mainly heard great reviews from the Schiit Bifrost for the Crack. Any noticeable differences between the two DAC's?


 
  
 Bifrost Uber with USB2 is known to be a decent mid level standard for DACs. I am sure it is excellent. 
  
 However, I find that the Audio GD is usually amazing value for money. I've never done a head-to-head but ALL my DACs are Audio GD at the moment as I always want max value for money. also, the Audio GD USB32 implementation (with latest firmware) is one of the best available at this price point. I know people with top of the line setups who stopped using expensive converters because the Audio GD USB32 implementation improved so much that they no longer needed it. 
  
 Second hand bargains to look out for around that price point:
  
 Audio GD NFB1.32 (almost identical to the current NFB 1 - 2014), SA 1.32 (discontinued but awesome), NFB-3 2014 (old NFB-3 are completely different and inferior), Reference 5.32, DAC19-DSP (if you are willing to use Audiophilleo converter as the USB for this particular unit, if it exists, is average).


----------



## Aeolus Kratos

atsq17 said:


> Bifrost Uber with USB2 is known to be a decent mid level standard for DACs. I am sure it is excellent.
> 
> However, I find that the Audio GD is usually amazing value for money. I've never done a head-to-head but ALL my DACs are Audio GD at the moment as I always want max value for money. also, the Audio GD USB32 implementation (with latest firmware) is one of the best available at this price point. I know people with top of the line setups who stopped using expensive converters because the Audio GD USB32 implementation improved so much that they no longer needed it.
> 
> ...


 
 I just want to echo this wonderful suggestion. I'd used many DACs with my Crack and I really found Audio GD DACs offer excellent value. I've used my NFB-7 (2014) with Audio GD DI-2014 converter for my Crack and my T1/HD650 sound absolutely fantastic.


----------



## atsq17

aeolus kratos said:


> I just want to echo this wonderful suggestion. I'd used many DACs with my Crack and I really found Audio GD DACs offer excellent value. I've used my NFB-7 (2014) with Audio GD DI-2014 converter for my Crack and my T1/HD650 sound absolutely fantastic.


 
  
  
 Wow nice. That's the very high end version of what I was suggesting.


----------



## Jimmy24

Fantastic, thanks for the suggestions guys. You guys sold me pretty well on the Audio GD. Will look into buying one when I'm ready for the DAC.


----------



## rock-solid

+1 for the Reference 5.32. Fantastic PCM1704 implementation. Unfortunately discontinued (because the chips getting rare), so only few out there available.


----------



## Utopia

These new 470 ohm Audio Technicas will be very interesting to hear with the Crack:
 http://www.audio-technica.com/cms/headphones/f39784ce643a82e6/index.html
  
 According to Amazon they will be released on May 1.


----------



## Doc B.

Am I the only one reading "open back headphones for professional settings" and scratching his head? AT makes some mighty nice cans and I will be very interested to hear them.


----------



## lextek

doc b. said:


> Am I the only one reading "open back headphones for professional settings" and scratching his head? AT makes some mighty nice cans and I will be very interested to hear them.



Yeah. Love to try them with the Crack. Looks like Amazon has them listed for release May 1st gor $349.


----------



## skeptic

Very interested to hear more about these as well.  Hd650's need some competition, and if the street price is $350, these should do just that.  Wonder why ATH didn't go with larger 53mm drivers though.  I love that deep bass slam on my es10's, and a more neutral, open, high impedance version of them would be very intriguing indeed.


----------



## atomicbob

doc b. said:


> Am I the only one reading "open back headphones for professional settings" and scratching his head? AT makes some mighty nice cans and I will be very interested to hear them.


 
 No, you are not alone. I too use ATH-M50 quite a bit in the studio but can't imagine an open back for tracking or overdubbing.


----------



## ZachPtheDude

aeolus kratos said:


> I just want to echo this wonderful suggestion. I'd used many DACs with my Crack and I really found Audio GD DACs offer excellent value. I've used my NFB-7 (2014) with Audio GD DI-2014 converter for my Crack and my T1/HD650 sound absolutely fantastic.




Hey, Ive been considering the Audio GD interface. Have you compared it to any others, and what was the total cost after shipping (I've heard audio-gd is great with shipping times)? My setup will be the same, minus DACs (I have a mhdt labs paradisea 3)


----------



## dpastern

Would love one of these, but I have zero electronics knowledge and the only time I tried some soldering it didn't end well.  Buying pre-assembled from the used section isn't any good to me, since they'll all be 120V and non compatible with 230V for Australia.  And I don't have the patience to wait X amount of time for it to be made, and then shipped to someone for them to assemble for me.  If only Bottlehead offered assembled units, directly purchased from them, with little wait.  
  
 Dave


----------



## Angerer

dpastern said:


> Would love one of these, but I have zero electronics knowledge and the only time I tried some soldering it didn't end well.  Buying pre-assembled from the used section isn't any good to me, since they'll all be 120V and non compatible with 230V for Australia.  And I don't have the patience to wait X amount of time for it to be made, and then shipped to someone for them to assemble for me.  If only Bottlehead offered assembled units, directly purchased from them, with little wait.
> 
> Dave


 
  
 Hi Dave, you really shouldn't hesitate to have one pre built.
  
 Talk to Shawn aka *hifibuilderguy* the man is a true gentleman he will build your BHC and mod it for you if you so wish.
  
 I had mine pre built by Shawn and shipped to me here in England, didn't take long at all and Shawn kept me up to date with everything and answered all my questions.
  
 http://bottlehead.com/smf/index.php?topic=4783.0
  
 well worth it imo.
  
 - Angerer
  
 Edit*  if you have a read around on here there's a few who've had theirs custom built by Shawn


----------



## dpastern

angerer said:


> Hi Dave, you really shouldn't hesitate to have one pre built.
> 
> Talk to Shawn aka *hifibuilderguy* the man is a true gentleman he will build your BHC and mod it for you if you so wish.
> 
> ...


 
  
 yeah, I read about that.  I'll give it a mull over in the next few months whilst I save up.  How will the crack go with Sennheiser HD540 ref golds and Audeze LCD2s I wonder?  It'll probably be mostly used with the HD600s that I've just bought though.  
  
 Some questions - since I'm new to stand alone headphone amps - can I use this with my AK 120 II DAP and just plug the DAP straight into the input sockets at the rear of the crack?
  
 Just reading this review on the crack and crack/speedball upgrade:
  
 http://diy.koenigs.dk/2014/03/02/bottlehead-crack-and-speedball-review/
  
 and trying to figure out if I'd like the speedball upgrade or not.  I'm a tube guy, and I like tubes cos they're relaxed and musical and enjoyable compared to transistors.  I'm not too sure if the speedball upgrade would make the crack more transistor like than tube like.  I'm not usually a fan of hyper presentation and etched ultra detail in audio gear as I've personally found that it tends to detract from the musicality, which is far more important to me.  An amp that sounds ultra detailed to me but lacks musicality is of no interest.  How would you or others describe the speedball improvements?  Would they be worthwhile or would they make the amp sound more like I dislike amps to sound?
  
 Dave


----------



## Jimmy24

To my ears the Speedball made minimal improvement. I actually liked the sound of the Crack before the Speedball upgrade. I was a bit disappointed with what I've read from reviews that it made a night and day difference which was untrue (for me at least). I actually heard a bigger difference when I was installing the relatively inexpensive mods like adding film caps. Different tubes will also help you get a sound signature to your liking. I would get it without the Speedball upgrade and just go from there. If you ever need to upgrade the Speedball you can always ask someone to install it for you in the future.


----------



## MoatsArt

Welcome back, me!


----------



## Serenitty

dpastern said:


> yeah, I read about that.  I'll give it a mull over in the next few months whilst I save up.  How will the crack go with Sennheiser HD540 ref golds and Audeze LCD2s I wonder?  It'll probably be mostly used with the HD600s that I've just bought though.
> 
> Some questions - since I'm new to stand alone headphone amps - can I use this with my AK 120 II DAP and just plug the DAP straight into the input sockets at the rear of the crack?
> 
> ...




Yes, just set the AK120ii to line out and use a 1/8" to rca cable to plug it in. I'll be trying that with my T1/crack combo next weekend when my AK120ii arrives. If it ever does...


----------



## atomicbob

jimbo24 said:


> To my ears the Speedball made minimal improvement. I actually liked the sound of the Crack before the Speedball upgrade. I was a bit disappointed with what I've read from reviews that it made a night and day difference which was untrue (for me at least). I actually heard a bigger difference when I was installing the relatively inexpensive mods like adding film caps. Different tubes will also help you get a sound signature to your liking. I would get it without the Speedball upgrade and just go from there. If you ever need to upgrade the Speedball you can always ask someone to install it for you in the future.


Still rocking the stock Crack here. I have yet to install the speedball upgrade though it awaits in my lab. Tube rolling I arrived at a sound signature that pleases my preferences, though I may consider the film cap mods. Someday I hope to A/B compare stock and SB at Doc's.


----------



## dpastern

serenitty said:


> Yes, just set the AK120ii to line out and use a 1/8" to rca cable to plug it in. I'll be trying that with my T1/crack combo next weekend when my AK120ii arrives. If it ever does...


 
  
 Thank you!  You're gonna love the AK120 II - it's an amazing thing (although truth be told, it is overpriced).


----------



## jazzwave

I ordered BH Crack on Feb 4 , send to NY, I'm still waiting the package arrive.
This wil be my first DIY tube amp, planning to pair with my HD600...wish me luck

~ron~


----------



## Jimmy24

That's awesome Ron! Just take your time, and you'll be fine. 
  
 Good luck!


----------



## bigfatpaulie

jazzwave said:


> I ordered BH Crack on Feb 4 , send to NY, I'm still waiting the package arrive.
> This wil be my first DIY tube amp, planning to pair with my HD600...wish me luck
> 
> ~ron~


 
  
 It's a beast of rig!  IMHO the best bang/buck combo out there.  
  
 "Just take your time, and you'll be fine." should be Bottlehead's slogan


----------



## JamieMcC

jazzwave said:


> I ordered BH Crack on Feb 4 , send to NY, I'm still waiting the package arrive.
> This wil be my first DIY tube amp, planning to pair with my HD600...wish me luck
> 
> ~ron~


 

 Congrats and enjoy the experience, while you waiting for your package to arrive I suggest you enjoy a pint of Guinness and remind yourself that,
  
 "Good things come to those who wait"
  
 
  
 I saw this image and it made me chuckle


----------



## rock-solid

atomicbob said:


> Still rocking the stock Crack here. I have yet to install the speedball upgrade though it awaits in my lab. Tube rolling I arrived at a sound signature that pleases my preferences, though I may consider the film cap mods...


 
  
 Same with me here. no need for an upgrade until now (although all things I want to try are on my desk already).
 Nevertheless the ghetto-look my wood case had felt not right for the amazing sound that comes out f this box.
 So I got my woodwork done the last week.


----------



## Jimmy24

Nice base and finish you got there rock. Definitely think the smooth corners make a big difference. I think I'll have to get mine like that soon.


----------



## JamieMcC

rock-solid said:


> Same with me here. no need for an upgrade until now (although all things I want to try are on my desk already).
> Nevertheless the ghetto-look my wood case had felt not right for the amazing sound that comes out f this box.
> So I got my woodwork done the last week.


 

 Nice looking build congrats, I am a fan of the the GEC 6080 as well, its a nice sounding tube.


----------



## atomicbob

jazzwave said:


> I ordered BH Crack on Feb 4 , send to NY, I'm still waiting the package arrive.
> This wil be my first DIY tube amp, planning to pair with my HD600...wish me luck
> 
> ~ron~


 
 Crack + HD600 = excellent combination. Congrats!


----------



## atomicbob

rock-solid said:


> Same with me here. no need for an upgrade until now (although all things I want to try are on my desk already).
> Nevertheless the ghetto-look my wood case had felt not right for the amazing sound that comes out f this box.
> So I got my woodwork done the last week.


 
 That is one very nice looking case! Wish I had some woodworking skills.


----------



## moriez

atomicbob said:


> jazzwave said:
> 
> 
> > I ordered BH Crack on Feb 4 , send to NY, I'm still waiting the package arrive.
> ...


 
  
 Oh yes! I believe it to be the best combination that I have heard since becoming a HD600 fan. I just made the change from stock tubes to Bendix 6080WB plus RCA Cleartop which seems to give that little more openness I was looking for. We're getting somewhere now in this hobby! 
  
  


doc b. said:


> mordicai said:
> 
> 
> > Yah, same problem. Only discovered it recently as I never turn the volume knob that far. SB,5998,hd 600's. Just the last few millimeters and a LOUD hum! Wonder what it is. Got some insight for us Doc?
> ...


 
  
 Downside of the newly installed tubes is that I'm now experiencing the above. A big buzz when the volume is turned all the way down. Doesn't bother me big time since just above zero volume there is no buzz. At some point I may want to fix this though and my question is, wouldn't installing another potentiometer (am thinking the Dale upgrade) solve this too?


----------



## atomicbob

moriez said:


> *edit*
> 
> Downside of the newly installed tubes is that I'm now experiencing the above. A big buzz when the volume is turned all the way down. Doesn't bother me big time since just above zero volume there is no buzz. At some point I may want to fix this though and my question is, wouldn't installing another potentiometer (am thinking the Dale upgrade) solve this too?


 
 You can temporarily attach two 50K ~ 100K ohm resistors between each of the center taps on the volume potentiometer and ground to check if the buzz is reduced or eliminated. If so, you have a faulty pot. These resistors provide a guaranteed shunt for the 12AU7 grids if the pot is becoming open circuit at the trouble point in rotation.


----------



## Doc B.

moriez said:


> Downside of the newly installed tubes is that I'm now experiencing the above. A big buzz when the volume is turned all the way down. Doesn't bother me big time since just above zero volume there is no buzz. At some point I may want to fix this though and my question is, wouldn't installing another potentiometer (am thinking the Dale upgrade) solve this too?




Depends upon what is causing the hum. That depends somewhat upon when you took delivery of your kit. Sounds like a perfect opportunity to take advantage of our tech support forum. There you can talk with the designer and narrow it down.

http://bottlehead.com/smf/index.php?board=24.0

Re our slogan as "take your time". I agree, though I would change it slightly to "patience should be your favorite tool".
Our slogan years ago was "shut up and listen". We put it on the back of a t-shirt, directed at the guys who would constantly yammer in the back of the room at a listening demo.


----------



## Loquah

moriez, I recall reading about this buzz on the forums Doc has directed you to. The highly informative peeps over on the BH forum will have you sorted in a jiffy.

If I remember correctly, the buzz could be Speedball related if you've installed the SB, but don't trust my memory - I'm in the final days of wedding preparations so my head is a scary place right now with all the tasks flying around in my mind


----------



## Schizeophonic

rock-solid said:


> Same with me here. no need for an upgrade until now (although all things I want to try are on my desk already).
> Nevertheless the ghetto-look my wood case had felt not right for the amazing sound that comes out f this box.
> So I got my woodwork done the last week.


 
  
  
 Gasp! I was pursuing through some bottlehead threads looking for case ideas.... and this one is a beauty! Love the legs, smoothed edges, and especially the knob. Where can I get a knob like that?


----------



## rock-solid

schizeophonic said:


> ...Where can I get a knob like that?


 
  
 I got it from a little electronic shop around the corner for 2€. 
 I could get one for you but depending on where you live the shipping cost may be too high.


----------



## Schizeophonic

rock-solid said:


> I got it from a little electronic shop around the corner for 2€.
> I could get one for you but depending on where you live the shipping cost may be too high.


 
  
 Yeah - I am in the states... shipping is probably prohibitive. The last time I was in Europe was for the Love Parade in Berlin, Germany in 2000 - maybe for my next visit. Thanks for the offer though! You did some great work on your bottlehead!


----------



## D4NGER BIRD

rock-solid said:


>


 
  
 What would be the best way for a novice to round off the edges like this? Looks great!


----------



## rock-solid

d4nger bird said:


> What would be the best way for a novice to round off the edges like this? Looks great!


 

 I hope Google translation found the right words: if you want it smooth and even you need a router (milling machine?). I used 2 different shapers: a smaller one for top and bottom and a larger one for the sides.
 If you don´t have that machine find one who has one. It is only 2 minutes of work for a professional. You could send it over to me and I would do the job for you, but a local carpenter will sure be cheaper than the postage fees.
 Only other way is to use rasp, file and sanding paper. But that way it will be hard to get an even look.


----------



## moriez

atomicbob said:


> moriez said:
> 
> 
> > *edit*
> ...


 
  
 Oh no, over my head. I bought the Crack prebuild and rather stay away from anything technical for now. For my own good  Appreciate your suggestion though.
  


doc b. said:


> moriez said:
> 
> 
> > Downside of the newly installed tubes is that I'm now experiencing the above. A big buzz when the volume is turned all the way down. Doesn't bother me big time since just above zero volume there is no buzz. At some point I may want to fix this though and my question is, wouldn't installing another potentiometer (am thinking the Dale upgrade) solve this too?
> ...


 
  
 From what I've read I *was* already certain that it's the faulty batch of MJE350's. Or not? The Crack kit plus Speedball was sent to the original owner on the 14th of January 2014. Thanks for the link.
  


loquah said:


> @moriez, I recall reading about this buzz on the forums Doc has directed you to. The highly informative peeps over on the BH forum will have you sorted in a jiffy.
> 
> If I remember correctly, the buzz could be Speedball related if you've installed the SB, but don't trust my memory - I'm in the final days of wedding preparations so my head is a scary place right now with all the tasks flying around in my mind


 
  
 Thanks Loquah, I think you're right. Will contact the original owner if needed. (Enjoy your wedding day!)


----------



## Doc B.

If the kit was packed and shipped around January 2014 it could possibly have the bad transistors. I would have to check with Josh to be sure when those popped up. They were taken out of inventory many months ago. There are other reasons it could have the problem it has. It might be best to take this to the Bottlehead Forum for troubleshooting - more eyes on with hands on experience. If you do go over there a close up photo of both sides of the transistor will help us to identify if they might be the ones that would oscillate.


----------



## moriez

Thanks again Doc. Will make my way there soon enough.


----------



## NotaLefty

Hi, I've got a Bottlehead Crack and I'm having some problems with static / distortion. It is mostly in the right channel as far as I can tell. It seems random and presents itself rather frequently. Sometimes it is worse than others. Does anyone know what is going on?


----------



## D4NGER BIRD

Just finished up my Crack tonight, not one hiccup, everything measured right the first time out. Awesome instructions. Listening right now and it is fantastic.


----------



## i luvmusic 2

Congrats!


----------



## Jimmy24

notalefty said:


> Hi, I've got a Bottlehead Crack and I'm having some problems with static / distortion. It is mostly in the right channel as far as I can tell. It seems random and presents itself rather frequently. Sometimes it is worse than others. Does anyone know what is going on?


 
  
 Start a thread here and you will get replies faster from Bottlehead themselves
  
 http://bottlehead.com/smf/index.php?board=24.0


----------



## Jimmy24

Lovely paint job on the chassis! Enjoy your newly built Crack Danger. 
  
 Happy listening my friend


----------



## jazzwave

jamiemcc said:


> Congrats and enjoy the experience, while you waiting for your package to arrive I suggest you enjoy a pint of Guinness and remind yourself that,
> 
> "Good things come to those who wait"
> 
> ...



 


Based on your experience , how long delivery time for BH Crack start from order date?

waiting mode: ON


----------



## JamieMcC

jazzwave said:


> jamiemcc said:
> 
> 
> > Congrats and enjoy the experience, while you waiting for your package to arrive I suggest you enjoy a pint of Guinness and remind yourself that,
> ...


 
  
 As I am not based in the US but UK it takes a little longer for perhaps 6 weeks and in the US it might be half that depending on where a bouts you are based.
  
 Don't be but off as its a great time to visit the Bottlehead forum and pick up some handy tips and ideas on finishes read through the tube rolling thread and take some inspiration from past builds in the gallery section in preparation for its arrival.
  
 I have done several kits now and have never worried about delivery times that way when they arrive its a unexpected surprise!
  
 Good things come to those who wait.


----------



## JamieMcC

d4nger bird said:


> Just finished up my Crack tonight, not one hiccup, everything measured right the first time out. Awesome instructions. Listening right now and it is fantastic.


 
  
 Congratulations nice work I like the silver finish to the top. I notice you have some different resistors fitted to the more commonly seen ones, did they come with the kit?


----------



## johthor

I also had a Bottlehead Crack built for me by Shawn and can highly recommend him.  Shawn is an excellent guy to deal with and patiently answered all of my questions re the build.  The build was really professionally done and he was very quick.


----------



## Mich4lle

Did I do it right?


----------



## i luvmusic 2

Will if it passed the Resistance and Voltage checked then you did it right.........................


----------



## Mich4lle

That joke didn't work nearly as well as I thought it would. 


 


It works perfectly, it has been up and running for about two weeks and it is great.


 


The only thing is that it buzzes slightly when playing battlefield. (It is plugged into my Asus essence STX sound card in my PC and is silent in all other applications.)


----------



## i luvmusic 2

So it's the source nothing to do with the crack.


----------



## Schizeophonic

notalefty said:


> Hi, I've got a Bottlehead Crack and I'm having some problems with static / distortion. It is mostly in the right channel as far as I can tell. It seems random and presents itself rather frequently. Sometimes it is worse than others. Does anyone know what is going on?


 
  
 How is the Crack hooked up? In my setup, I had a lot of issues using USB dacs. All my problems went away when using a DAC with optical. I was able to isolate the usb power on my desktop as the culprit by using my USB dac with a laptop on battery (no noise).
  
 It's worth a shot to to try another output.


----------



## NotaLefty

schizeophonic said:


> How is the Crack hooked up? In my setup, I had a lot of issues using USB dacs. All my problems went away when using a DAC with optical. I was able to isolate the usb power on my desktop as the culprit by using my USB dac with a laptop on battery (no noise).
> 
> It's worth a shot to to try another output.



Zotac Pico > Music Hall 25.3 > Bottlehead Crack. I've had the issue from multiple sources and headphones and have narrowed it down to the amp.


----------



## D4NGER BIRD

jamiemcc said:


> Congratulations nice work I like the silver finish to the top. I notice you have some different resistors fitted to the more commonly seen ones, did they come with the kit?


 

 Yeah, I noticed that it was slightly different from what I had seen. The 270ohm resistor under the transformer is larger 10w rather than the shorter 5w. My Crack came with a note for the deviation, I'm no EE, so I asked no questions and followed the directions.


----------



## ohcrapgorillas

Welp, just placed my order for the Crack with speedball upgrade, for powering the HD650... and the wait begins! What I really wanted was the SEX, but unfortunately can't justify the extra expense. I didn't even mean to order the speedball at the time, that just kinda...happened. Hah.
  
 I'm curious if anyone has had any experience with listening to low-impedance cans using the Crack and an impedance adapter? I know the Etymotic ER4P has an impedance adapter that can "turn it into" the ER4S. I'm curious if using an impedance adapter with other headphones would make them more suitable, like Grados or even single-driver IEMs. Just a thought.


----------



## lost&confused

mich4lle said:


> That joke didn't work nearly as well as I thought it would.
> 
> It works perfectly, it has been up and running for about two weeks and it is great.
> 
> The only thing is that it buzzes slightly when playing battlefield. (It is plugged into my Asus essence STX sound card in my PC and is silent in all other applications.)


 
  
 its best or you should really be playing games like bf with the headphones plugged directly into the soundcard so you have good stereo positioning ...... so sounds around you are not confusing at where there are coming from  
 thats what I find anyway


----------



## lost&confused

saying that..... I thought the new bf4 game had horrible stereo positioning with my headphones and sound card .... or it could be my zxr sound card,


----------



## skeptic

ohcrapgorillas said:


> Welp, just placed my order for the Crack with speedball upgrade, for powering the HD650... and the wait begins! What I really wanted was the SEX, but unfortunately can't justify the extra expense. I didn't even mean to order the speedball at the time, that just kinda...happened. Hah.
> 
> I'm curious if anyone has had any experience with listening to low-impedance cans using the Crack and an impedance adapter? I know the Etymotic ER4P has an impedance adapter that can "turn it into" the ER4S. I'm curious if using an impedance adapter with other headphones would make them more suitable, like Grados or even single-driver IEMs. Just a thought.


 
  
 As I understand it - an impedance adapter basically takes you in just the opposite direction from the standpoint of impedance matching.  It effectively increases the output impedance of the amp, rather than effectively increasing the impedance of the headphones - while eating some noise en route.  This is why people who are looking to emulate the sennheiser ss amp's ~40ohm output (which, enhances midbass on hd800's based on its impedance curve), will add impedance adapters to their 0 ohm output amps (like GS1's, dynalo's, etc) to raise the amp's effective output impedance and create the same resulting FR as the Senn amps.  (Google up hd800 and IEC 120 ohm standard for more on this.)
  
 I used to use a small (~30ohm) impedance adapter with my westone 4's, when plugged into my note 2, so the phone's hiss wouldn't drive me bonkers, but it did change the sound of the headphones, and not for the better IMO.  Of course, this is greatly complicated by the fact that westones are multi-driver iem's while etymotics only use a single "full range" ba driver.  Never totally understood why etymotic claims that er4's (or 4p's + adapter) have more accurate FR than the ordinary 4p.  Maybe all they are really saying is that this particular driver best matches their target FR curve when amped via 75 ohm ouput impedance?


----------



## NightFlight

Anyone going in for a Mainline this weekend? Its %10 off if you buy two ($120) and $200 on top of that.  I'm looking to partner up with someone.


----------



## krikor

Got around to finishing the base. Not perfect, some blemishes, and I should have used some conditioner before the stain. Used some panhead cabinet screws to hold down the top plate, countersunk into the edge of the base.


----------



## JamieMcC

nightflight said:


> Anyone going in for a Mainline this weekend? Its %10 off if you buy two ($120) and $200 on top of that.  I'm looking to partner up with someone.


 

 I have already bit the bullet and am planning to thin out my collection of spare Crack tubes collected over the last few years to help fund the purchase.


----------



## NightFlight

Dammit!
  
 I've almost funded the whole thing with Lyr tubes!


----------



## NightFlight

krikor said:


> Got around to finishing the base. Not perfect, some blemishes, and I should have used some conditioner before the stain. Used some panhead cabinet screws to hold down the top plate, countersunk into the edge of the base.


 
 Looks good. Is that just gloss enamel spray paint?


----------



## JamieMcC

krikor said:


> Got around to finishing the base. Not perfect, some blemishes, and I should have used some conditioner before the stain. Used some panhead cabinet screws to hold down the top plate, countersunk into the edge of the base.


 
  
 Understated yet funky, what are you using for the feet, spikes sat on disks?


----------



## ZachPtheDude

jamiemcc said:


> I have already bit the bullet and am planning to thin out my collection of spare Crack tubes collected over the last few years to help fund the purchase.




I'm sure some of us Head-Fi bottleheads could help you get rid of those tubes


----------



## krikor

nightflight said:


> Looks good. Is that just gloss enamel spray paint?


 
 Yep, ACE Hardware spray paint. Went on good, but can scrap off easily.
  
  


jamiemcc said:


> Understated yet funky, what are you using for the feet, spikes sat on disks?


 
  
 Yes. Had a bunch of extra spikes sitting around that I got cheap from Parts Express, came with matching discs. They screw into threaded inserts I drilled into the bottom corners of the base.


----------



## jlucas

nightflight said:


> Anyone going in for a Mainline this weekend? Its %10 off if you buy two ($120) and $200 on top of that.  I'm looking to partner up with someone.


 
 Very tempted but probably not the right time as I'm still only 3 months into my Crack+SB and have a Geek Pulse XFi coming soon.


----------



## Utopia

A question about noise: when people say the Crack should be dead quiet, is that at listening levels? Or should it be dead quiet when turning the volume up to 100 %, without any kind of hum or buzz? I'm asking because I do get noise that starts at perhaps 75 % of max volume and then increases. I've tried reflowing solder joints (didn't make any difference, but I did skip some).


----------



## nailbunny7

utopia said:


> A question about noise: when people say the Crack should be dead quiet, is that at listening levels? Or should it be dead quiet when turning the volume up to 100 %, without any kind of hum or buzz? I'm asking because I do get noise that starts at perhaps 75 % of max volume and then increases. I've tried reflowing solder joints (didn't make any difference, but I did skip some).


 
 For me, I stopped getting noise when I swapped out my potentiometer for a stepped attenuator. Not that this matters much, as long as there is not noise at volumes you listen to (for me, 75% volume would have been way too high).


----------



## NightFlight

nightflight said:


> Anyone going in for a Mainline this weekend? Its %10 off if you buy two ($120) and $200 on top of that.  I'm looking to partner up with someone.


 
  
 I pulled the trigger.


----------



## NightFlight

The potentiometer is one of the sacrifices made on the Crack made to keep the price down. Putting a better one is pretty much straight replacement. The bottlehead forums have threads on it.


----------



## skeptic

nightflight said:


> I pulled the trigger.


 
  
 Congrats NF!  Welcome to team mainline 
	

	
	
		
		

		
			





  No doubt about it - simply a wonderful HP amp.  Looking forward to your build pics and impressions upon completion.


----------



## NightFlight

I'm looking forward to putting up against my tricked out Crack. I've heard *great *things about rigging the Crack to handle a 5687 tube in the pre section. Given the value of my Crack is 3/4 of a mainline now, in the end it might not be much of a surprise that it comes close or meets it in capacity.
  
 There's a post on head-fi here about the 6C45 tube which sites its attributes as simply stellar. One has to wonder.


----------



## StivVid

Quote:


utopia said:


> A question about noise: when people say the Crack should be dead quiet, is that at listening levels? Or should it be dead quiet when turning the volume up to 100 %, without any kind of hum or buzz? I'm asking because I do get noise that starts at perhaps 75 % of max volume and then increases. I've tried reflowing solder joints (didn't make any difference, but I did skip some).



  
 I've built several Cracks--with and without the Speedball upgrade.  They've all been dead silent even at full volume.


----------



## Utopia

Thank you! Then I have more work to do.


----------



## Beefy

utopia said:


> Thank you! Then I have more work to do.


 
  
 Don't forget that it could be noise from your source. And even if it isn't, noise at 75% volume is absolutely nothing to be concerned about - the Crack would be positively deafening at that level.


----------



## StivVid

beefy said:


> Don't forget that it could be noise from your source. And even if it isn't, noise at 75% volume is absolutely nothing to be concerned about - the Crack would be positively deafening at that level.


 

 That's very true.  I rarely have any reason to turn the knob past 50%.  Usually keep it at around the 10 o'clock position.


----------



## Utopia

Same here about the volume. Usually I keep it somewhere around 25-35 %. I just want to make sure my build is the best it can be.


----------



## JamieMcC

The noise floor can be different depending on the impedance of your cans the lower their impedance the earlier you might expect to hear it as the volume pot is rotated closer to maximum.
  
 At least that's how I think it works?


----------



## Utopia

In my case the headphones are Beyerdynamic T1 (600 ohm). And the noise if the same if I unplug the input RCAs, or move it to a different room, so it's definitely the amp.


----------



## JamieMcC

utopia said:


> In my case the headphones are Beyerdynamic T1 (600 ohm). And the noise if the same if I unplug the input RCAs, or move it to a different room, so it's definitely the amp.


 

 Ok, I have T1's also and with the amp on and no music playing can turn the amp up to full volume only hearing the slightest noise floor present at about 95% of full volume .
  
 As a suggestion look carefully at the routing of all your leads try and keep the mains clear from signal etc another thing worth a try is putting a few twists in the RCA leads between your dac and the Crack its a quick and easy thing to try and could  help if you are picking up any noise interference through them.
  
 Have you any other tubes to try?


----------



## StivVid

utopia said:


> In my case the headphones are Beyerdynamic T1 (600 ohm). And the noise if the same if I unplug the input RCAs, or move it to a different room, so it's definitely the amp.




I have noticed before that with no input plugged into the amp there is a hum. As soon as I plugged in my source, the humming went away. For what it's worth, I've always run HD600's with mine. You might try a different set of rca cables too. Also... If you're plugged into a faulty power strip you could have a grounding issue.


----------



## StivVid

Just had a thought...  Do you know if your rca cables have a "floating ground?"  What I mean by that is, do they have the cable's braided shield soldered to the connector at one end but not the other?  Many so called "high end" cables are built this way.  It's supposed to have an effect on noise rejection, etc.  I've never heard a difference myself.
  
 I just tried another pair of audio cables that fit this description, and sure enough--when I reach about 85-90% volume (with a source plugged in) I can hear a hum that gets a little louder as I go from 85-90% volume up to 100%.  Could be your interconnects.


----------



## MattTCG

If you are a Crack builder, this post is not for you. For those who might be looking for a builder and would like a recommendation, this might be for you so read on...
  


Spoiler: Warning: Spoiler!



Bottlehead Crack Built For YOU...
  
 I have owned several Crack amps over the past five years. My affinity for the Sennheiser hd650 has put the Crack high on my list of favorite amps. It's a daunting task to find any amp that pairs nearly as well as the Crack for less than $1k. The BHC is essentially a custom amp catering to hd6x0 owners. The pairing is somewhat legendary in audio circles and justifiably so.
  
 The problem with the Crack is that it comes as a kit and honestly, my soldering skills are fair at best. Enter your friendly Crack builder. For me, I was fortunate enough to discover a very nice guy who lived about three blocks from my house...small world. I found Rob through Audiogon. He has been building Crack amps and selling to those looking for a “pre-built” amp for quite a while. Unlike myself, Rob is very good with a soldering iron. Pull the top off one of Rob's builds and you'll see what I mean. Everything is done with precision, care and craftsmanship. All the solder points and wiring are spot on. The solder points are tested and retested. It's very much a professional build. The quality of the Rob's build becomes immediately apparent when you cue up the music.
  
 Rob also adds some nice touches to the cosmetics. The bell and power transformer are painted a nice semi gloss black and the effect is high quality. The top plate is left in it's factory condition which makes a nice contrast to the black from the transformer. Rob also painted the silver ring around the driver tube black to match the transformer...a nice touch. The wood base is put together nicely with a light coat of walnut stain and poly applied. Again, it's the simple things that are done well here. There are no gaps or rough edges on the base and no drips or runs on the poly. A pair of right angle adapters for the RCA connections as well as a right angle power cord were included with the build.
  
 For those of you looking for a pre-built Crack and don't want to buy a used Crack, then look no further...I can highly recommend the work that Rob does.
  
 The end result. The amp that Rob built for me is just what I had hoped for, flawless. The background during playback is completely black. There are no odd hums or such coming from this Crack build. Just beautiful music with my hd650's.


----------



## StivVid

Hey! I recognize that amp! Thanks, Matt.

I am indeed open to the possibility of building for others who don't feel up to the DIY challenge.

R


----------



## Utopia

stivvid said:


> Just had a thought...  Do you know if your rca cables have a "floating ground?"  What I mean by that is, do they have the cable's braided shield soldered to the connector at one end but not the other?  Many so called "high end" cables are built this way.  It's supposed to have an effect on noise rejection, etc.  I've never heard a difference myself.
> 
> I just tried another pair of audio cables that fit this description, and sure enough--when I reach about 85-90% volume (with a source plugged in) I can hear a hum that gets a little louder as I go from 85-90% volume up to 100%.  Could be your interconnects.


 
  
 I tried different cables and got different results - more or less buzzing at 90 % with different cables. Then I remembered reading over at Bottlehead's forum about shorting the inputs, as part of the troubleshooting process, and when I tried that the amp was absolutely quiet. I think that means the amp itself is ok.
  
 Still I get noise even with nothing plugged in. Does that mean that the RCA inputs themselves are picking up noise?


----------



## StivVid

Well, I'm no electrical engineer and I'm sure there are those better qualified to answer your question.
  
 You will get hum from your amp when there is no source connected to the inputs.  I believe the reason for that is that those connectors are un-terminated until a source is plugged into them.  As soon as you plug a source in, the hum should disappear.
  
 Someone correct me if I'm wrong.
  
 You should visit the forums on Bottlehead's website.  They're really good about answering technical questions quickly and concisely.  Very helpful folks over there.


----------



## dsound

utopia said:


> I tried different cables and got different results - more or less buzzing at 90 % with different cables. Then I remembered reading over at Bottlehead's forum about shorting the inputs, as part of the troubleshooting process, and when I tried that the amp was absolutely quiet. I think that means the amp itself is ok.
> 
> Still I get noise even with nothing plugged in. Does that mean that the RCA inputs themselves are picking up noise?


 

 Hi there, I had the same fear after completing my build.  Nothing is wrong with your Crack IMO.  On another forum I read that if the inputs are  high impedance, this leads to a hum when nothing is connected.  To solve the issue, just make sure that your source is connected.  Hope that helps!


----------



## roguegeek

I have a Crack with Speedball upgrade and the stock tubes, but am looking to change those out for a group that will work well with an HD 650 and a group that will work well with an HD 800. Obviously, we have very drastic differences in signatures here, so I'd expect I'll need separate tubes. What would your suggestions be?


----------



## JamieMcC

roguegeek said:


> I have a Crack with Speedball upgrade and the stock tubes, but am looking to change those out for a group that will work well with an HD 650 and a group that will work well with an HD 800. Obviously, we have very drastic differences in signatures here, so I'd expect I'll need separate tubes. What would your suggestions be?


 
  
  
 If deep pockets driver tubes GEC 6as7g for a little less Tung-sol 5998 best bang for the buck GEC 6080 and Mullard 6080 imo
 Input tube Mullard & Tung-sol 12au7 and Tungsram E80cc
  
 Plenty of info here in Nick Tams excellent Crack tube review.
  
http://the-key.enix.org/~krystal/review-tube-bottlehead.html


----------



## roguegeek

jamiemcc said:


> If deep pockets driver tubes GEC 6as7g for a little less Tung-sol 5998 best bang for the buck GEC 6080 and Mullard 6080 imo
> Input tube Mullard & Tung-sol 12au7 and Tungsram E80cc
> 
> Plenty of info here in Nick Tams excellent Crack tube review.
> ...



More than enough info here to get me started. Thanks!


----------



## roguegeek

What do people think about the Orange Globes in the input? I have a couple left over after selling my Lyr.


----------



## chicken steve

Are there any advantages/disadvantages of using the 240VAC power transformer vs 140VAC mains? Which one is the most preferred option?


----------



## rock-solid

chicken steve said:


> Are there any advantages/disadvantages of using the 240VAC power transformer vs 140VAC mains? Which one is the most preferred option?


 

 There´s the huge advantage that the Crack will work and not starting to smoke when you match the transformer to the voltage that comes out of your wall.
 That could be as well your first exercise in getting ready to build your crack: get yourself a multimeter and measure the voltage in your wall socket.


----------



## NightFlight

roguegeek said:


> What do people think about the Orange Globes in the input? I have a couple left over after selling my Lyr.


 
  
 People should think that is the wrong 9-pin triode to stick in your Crack. Uh... that sounded rude...
  
 Seriously. I haven't tried it, but dropping a 6dj8/6922 into a socket wired for a 12AU7 is very likely a *badideaTM*


----------



## NightFlight

Wow. 240V transformer on 110V mains. A 6DJ8 into a 12AU7 socket... were on a roll tonight.  
  
 Before anyone asks, no - you can't use your amp in the bathtub.
  
 And if I sound like an ass, well this should diffuse that notion... I know first hand that you should not let your thumb drift near the amp's mains socket even though it is switched off. If is plugged in... its freakin' plugged in!


----------



## cspirou

chicken steve said:


> Are there any advantages/disadvantages of using the 240VAC power transformer vs 140VAC mains? Which one is the most preferred option?




The different transformers are only to accommodate the different voltage standards around the world. Just pick one depending on where you live.


----------



## grausch

nightflight said:


> And if I sound like an ass, well this should diffuse that notion... I know first hand that you should not let your thumb drift near the amp's mains socket even though it is switched off. If is plugged in... its freakin' plugged in!


 
 Same with touching the capacitors joints immediately after unplugging...


----------



## krikor

grausch said:


> Same with touching the capacitors joints immediately after unplugging...


 
  
 Yeah, I made that mistake... ONCE.


----------



## NightFlight

Sorry all. I didn't meant to sound cranky. I'm actually just concerned. 
  
 With the community what it is, cheap DIY kits like the Crack are falling into the hands of just about anyone. While the instructions give good warning about safety, we all know what happens when enough people are allowed to handle dangerous items. Even cautious people with experience occasionally make mistakes.  My preference would be for the un-initiated to start with low voltage circuits, as they do for good reason in high school or college basic electronics courses.
  
 I supposed this is an open forum and questions no matter how innocent should be encouraged.  My bad. My comments were uncalled for and as a former member of the instructor/teaching community I should know better. 
  
  
 ... and after looking up the pinouts with this excellent resource, I've started to raise my own questions regarding pin-outs. They are very similar:  http://www.bustedgear.com/res_Tube_pinouts.pdf
  
 But I believe the voltage and current differ significantly enough between the two tubes that the transformer windings in the crack will overdraw and smoke if you were to drop in a 6dj8/6922/ecc88 type.


----------



## Rocketman248

Phew! Finally made it through all 439 pages of this megathread. I've been loving my Crack w/ Speedball, and after reading through all of this and learning a ton, I've ordered an assortment of caps to try out, along with some other goodies.


----------



## bigfatpaulie

rocketman248 said:


> Phew! Finally made it through all 439 pages of this megathread. I've been loving my Crack w/ Speedball, and after reading through all of this and learning a ton, I've ordered an assortment of caps to try out, along with some other goodies.


 
  
 Congrats and welcome to Head-Fi.


----------



## MattTCG

Just wanted to report that a friend performed the resistor mod on my crack today. I've always been a low level listener and often have channel imbalance issues with the Crack...not being able to get it loud enough to get rid of the imbalance and drive the 650 with good dynamics. 
  
 Now I'm able to listen between 10-12 no problem and I love what I'm hearing!! Not sure why but sound staging is appreciably wider and imaging is so very very nice. Maybe because I'm able to give the 650's some proper voltage now...don't know for sure and don't really care. I just love what I hear coming from the crack and 650 now.


----------



## Doc B.

nightflight said:


> But I believe the voltage and current differ significantly enough between the two tubes that the transformer windings in the crack will overdraw and smoke if you were to drop in a 6dj8/6922/ecc88 type.




That is incorrect. However the tube socket must be rewired for the 6922 heater and the circuit values would need to be adjusted to be optimal. It's not a particularly useful mod.


----------



## DDDamian

Thanks Head-Fi - now I've bought a Crack w/speedball and a S.E.X. from members here in the last week lol. Got some explaining to do....
Can't wait until they arrive - going to be one joyous listening marathon!


----------



## i luvmusic 2

dddamian said:


> Thanks Head-Fi - now I've bought a Crack w/speedball and a S.E.X. from members here in the last week lol. Got some explaining to do....
> Can't wait until they arrive - going to be one joyous listening marathon!


 
 Congrats!
 So you killed two birds with one stone and yes you got a lot of explaining to do.


----------



## i luvmusic 2

rocketman248 said:


> Phew! Finally made it through all 439 pages of this megathread. I've been loving my Crack w/ Speedball, and after reading through all of this and learning a ton, I've ordered an assortment of caps to try out, along with some other goodies.


 
 Congrats!
 Now time for you to look at Sennheiser Hd 650 impressions thread it only have 1558 pages.......


----------



## Rocketman248

i luvmusic 2 said:


> Congrats!
> Now time for you to look at Sennheiser Hd 650 impressions thread it only have 1558 pages.......


 
 Should only take about 3 months.  Wish me luck.


----------



## DDDamian

Heh I've been trying to read all of both threads and enjoying it. Hmmmm if I sell this Crack/Speedball and the S.E.X, (neither of which have landed on my doorstep) I can get a Mainline.......
  
 One day, but for now can't wait for both!
  
 Thanks for all the great reading in both threads - this and the HD-650 megathread!!


----------



## i luvmusic 2

They are nice amp to have  i really like them they are a keeper for me i will get the mainline in the future.


----------



## JamieMcC

rocketman248 said:


> Phew! Finally made it through all 439 pages of this megathread. I've been loving my Crack w/ Speedball, and after reading through all of this and learning a ton, I've ordered an assortment of caps to try out, along with some other goodies.


 
  
 Welcome to Head-Fi and congratulations on ploughing your way through all 439 pages there where a few less when I read them all while waiting to take delivery of my kit.  If you get board there is always the Tube Rolling w/Crack  thread (only 74 pages) on the Bottlehead Forum
  
http://bottlehead.com/smf/index.php?topic=663.0
  
 With care packages inbound be careful you can easily get hooked and end up dependent on Crack...


----------



## JamieMcC

dddamian said:


> Thanks Head-Fi - now I've bought a Crack w/speedball and a S.E.X. from members here in the last week lol. Got some explaining to do....
> Can't wait until they arrive - going to be one joyous listening marathon!


 
  
 Your going to have a blast and expect some late nights!


----------



## DDDamian

jamiemcc said:


> Your going to have a blast and expect some late nights!



Thanks I'm sure from all the great reviews they'll be amazing with my HD-650's.

I have a nice piece of curly maple coming in for a custom base for the Crack. Will up some pics when it's done!


----------



## DDDamian

Guess what I'm doing this weekend 
  
 Silly me bought a Crack/Speedball + 5998 and an S.E.X from fellow head-fiers. The S.E.X. showed up yesterday so I got in a good listen and wow! I started with the HD-650's and the spectrum was very nicely balanced and super-silky. What amazed me even more was plugging in my ATH-m50xBL's. They really took off to a new level, much more so than the Senns gained compared to being powered by a Fiio X5/e12 combo. The detail was a step up, and they already had good clarity, but the S.E.X. took the edge off what I find a slightly bright and fatiguing can. The range extension is incredible and the lower end far deeper than what the 650's can pull off.
  
 Next up for testing is the Crack/Speedball. It has an Alps pot as well. I'll be trying out the stock tubes first, then move on to a Mazda input tube and a Tung Sol 5998, both of which came with it.
  
 Oh happy days - will report back


----------



## Kyno

dddamian said:


> Guess what I'm doing this weekend
> 
> Silly me bought a Crack/Speedball + 5998 and an S.E.X from fellow head-fiers. The S.E.X. showed up yesterday so I got in a good listen and wow! I started with the HD-650's and the spectrum was very nicely balanced and super-silky. What amazed me even more was plugging in my ATH-m50xBL's. They really took off to a new level, much more so than the Senns gained compared to being powered by a Fiio X5/e12 combo. The detail was a step up, and they already had good clarity, but the S.E.X. took the edge off what I find a slightly bright and fatiguing can. The range extension is incredible and the lower end far deeper than what the 650's can pull off.
> 
> ...


 
  
 Nice piece 
  
 Looking forward to your comparison, I already own a Crack, but I'm also interested in S.E.X. ( 
	

	
	
		
		

		
		
	


	




 )


----------



## DDDamian

kyno said:


> Nice piece
> 
> Looking forward to your comparison, I already own a Crack, but I'm also interested in S.E.X. (
> 
> ...


 
 My fear is I'll order a Mainline before fully assessing these lol. But that might mean divorce 
  
 Initial impressions are that the Crack/Speedball do pair better with the HD-650 but by the slightest of margins. It'll be interesting what the 5998 does for it. But that said - the ability to swap high-and-low-impedance headphones in and out is pretty huge. Ahhhhh decisions! That is the briefest assessment though - I can see it's going to be close.
  
 If these aren't end-game my god, what is?!
  
 And oh, never lose your interest in S.E.X.


----------



## i luvmusic 2

dddamian said:


> Guess what I'm doing this weekend
> 
> Silly me bought a Crack/Speedball + 5998 and an S.E.X from fellow head-fiers. The S.E.X. showed up yesterday so I got in a good listen and wow! I started with the HD-650's and the spectrum was very nicely balanced and super-silky. What amazed me even more was plugging in my ATH-m50xBL's. They really took off to a new level, much more so than the Senns gained compared to being powered by a Fiio X5/e12 combo. The detail was a step up, and they already had good clarity, but the S.E.X. took the edge off what I find a slightly bright and fatiguing can. The range extension is incredible and the lower end far deeper than what the 650's can pull off.
> 
> ...


 
 Congratz!
  
 Although i have both of them i haven't listen to them in a few months need to fix them when i have time.


----------



## JamieMcC

i luvmusic 2 said:


> Congratz!
> 
> Although i have both of them i haven't listen to them in a few months need to fix them when i have time.


 
  
 Go on do tell, how have you managed to kill both of them?


----------



## i luvmusic 2

jamiemcc said:


> i luvmusic 2 said:
> 
> 
> > Congratz!
> ...


 
 The CRACK i removed the 2 100uf caps got a emergency call from work left it the way it is since then.
  
 The SEX i accidentally push down the film cap and touches one of the resistor turned it on without knowing what had happened now left channel is dead toasted the left side of the C4S board and burnt the 0.1R resistor,I have the replacement Board but i'am still busy at work so maybe in a few weeks i will work on them.

  and these caps are going into the SEX.


----------



## i luvmusic 2

Oh and i still need to apply a finish on the wood chassis.MORE WORK for me.


----------



## DDDamian

i luvmusic 2 said:


> Oh and i still need to apply a finish on the wood chassis.MORE WORK for me.




Ouch I feel your pain. I'm looking forward to redo-ing the base of the Crack in the curly maple, partly because I love how that wood looks finished and partly because I didn't actually build either amp....


----------



## ZachPtheDude

http://www.mouser.com/ProductDetail/ALPS/RK27112A00AK/?qs=sGAEpiMZZMtC25l1F4XBUyOcKw5CnqLBt7NWCgOxelA%3d


Going to try an Alps Blue Velvet, figured what the heck. I believe the above alps pot linked to above is the correct one for the crack but please correct me if I am wrong. $20 shipped isn't much cash for an upgrade in the audiophile world.


Do any other crack owners in this thread use an Alps blue velvet? Is it a drop in replacement or will I need to widen the opening? Thanks!


----------



## nailbunny7

zachpthedude said:


> http://www.mouser.com/ProductDetail/ALPS/RK27112A00AK/?qs=sGAEpiMZZMtC25l1F4XBUyOcKw5CnqLBt7NWCgOxelA%3d
> 
> 
> Going to try an Alps Blue Velvet, figured what the heck. I believe the above alps pot linked to above is the correct one for the crack but please correct me if I am wrong. $20 shipped isn't much cash for an upgrade in the audiophile world.
> ...


 

 Honestly, you'll probably get better results from a cheap ladder attenuator such as the Valab ones. They're not much more than 20 shipped on eBay.


----------



## Keithpgdrb

nailbunny7 said:


> Honestly, you'll probably get better results from a cheap ladder attenuator such as the Valab ones. They're not much more than 20 shipped on eBay.


 

 explain.


----------



## nailbunny7

keithpgdrb said:


> explain.


 

 A potentiometer will add some artifacts to the signal path because of how they are built (using a metal wiper on a conductive material, such as graphite paint or plastics, to achieve its resistance), while a ladder resistor will not because it uses one resistor in the signal path and one to ground (there are other attenuator types, but ladder is my favorite). For that reason, if it fits, I would always use a stepped attenuator.


----------



## i luvmusic 2

zachpthedude said:


> http://www.mouser.com/ProductDetail/ALPS/RK27112A00AK/?qs=sGAEpiMZZMtC25l1F4XBUyOcKw5CnqLBt7NWCgOxelA%3d
> 
> 
> Going to try an Alps Blue Velvet, figured what the heck. I believe the above alps pot linked to above is the correct one for the crack but please correct me if I am wrong. $20 shipped isn't much cash for an upgrade in the audiophile world.
> ...


 
 I used the Alps blue in my Crack and the SEX actually all of my amps uses the alps blue.
 Maybe you need to widen the hole just a tiny bit to fit the alps,I installed the alps blue into my Crack amp after i was disappointed with the Attenuator that i purchased(see picture).
 The difference between the stock pot and the alps blue is not that much the alps blue is more balanced than the stock pot in a lower volume.
  
 A VOID THESE TYPE of CHEAP PoS.......


----------



## nailbunny7

i luvmusic 2 said:


> I used the Alps blue in my Crack and the SEX actually all of my amps uses the alps blue.
> Maybe you need to widen the hole just a tiny bit to fit the alps,I installed the alps blue into my Crack amp after i was disappointed with the Attenuator that i purchased(see picture).
> The difference between the stock pot and the alps blue is not that much the alps blue is more balanced than the stock pot in a lower volume.
> 
> A VOID THESE TYPE of CHEAP PoS.......


 

 Agreed. Those cheap series attenuators have a lot of opportunity to add noise to the circuit if any of the resistors are noisy or improperly soldered, since every resistor is in the signal path. These are my preference for cheap and easy attenuators:
http://www.ebay.ca/itm/Valab-23-Step-Ladder-Type-Attenuator-Potentiometer-100K-Log-Stereo-/301554222016?pt=LH_DefaultDomain_0&hash=item46360843c0


----------



## i luvmusic 2

Q 





> Agreed. Those cheap series attenuators have a lot of opportunity to add noise to the circuit if any of the resistors are noisy or improperly soldered, since every resistor is in the signal path. These are my preference for cheap and easy attenuators:
> http://www.ebay.ca/itm/Valab-23-Step-Ladder-Type-Attenuator-Potentiometer-100K-Log-Stereo-/301554222016?pt=LH_DefaultDomain_0&hash=item46360843c0


 
 That looks better than this Schiit.

 I'am thinking to get one of the one that you link  and make a passive preamp instead of  replacing all of my amps POT.Will it work?


----------



## nailbunny7

i luvmusic 2 said:


> That looks better than this Schiit.
> 
> I'am thinking to get one of the one that you link  and make a passive preamp instead of  replacing all of my amps POT.Will it work?


 

 If you are going to make a passive preamp, I would get it a 10K attenuator instead. But I still think it would be better to just replace the original pot if it were me.


----------



## i luvmusic 2

nailbunny7 said:


> i luvmusic 2 said:
> 
> 
> > That looks better than this Schiit.
> ...


 
 All my amp's POT are replaced with a Alps Blue Velvet.THANKS!


----------



## ZachPtheDude

Well, that VALab isn't much money at all, especially compared to a goldpoint. I ordered one of those too. I'll test both and part with whichever I prefer. The fun of DIY.


----------



## i luvmusic 2

The only problem i have with the 24 steps is where 7th clicks is not loud enough and on 8th clicks too loud for me,I need something like Khozmo 48 steps but they are pricey.


----------



## nailbunny7

i luvmusic 2 said:


> The only problem i have with the 24 steps is where 7th clicks is not loud enough and on 8th clicks too loud for me,I need something like Khozmo 48 steps but they are pricey.


 

 Khozmos are good, but keep in mind they are gigantic and would probably not fit in a Bottlehead Crack, whereas the Goldpoint and Valab do.


----------



## JamieMcC

i luvmusic 2 said:


> The only problem i have with the 24 steps is where 7th clicks is not loud enough and on 8th clicks too loud for me,I need something like Khozmo 48 steps but they are pricey.


 
  
http://glass-ware.stores.yahoo.net/a5stat.html
  
 Stuff it with RN55 Dales job done


----------



## ZachPtheDude

nailbunny7 said:


> Khozmos are good, but keep in mind they are gigantic and would probably not fit in a Bottlehead Crack, whereas the Goldpoint and Valab do.




A Khozmos in a crack? You would have to make a much larger housing for the crack, and probably use a 12 x 12 inch plate at the least. That'd be a huge piece of crack


----------



## i luvmusic 2

zachpthedude said:


> nailbunny7 said:
> 
> 
> > Khozmos are good, but keep in mind they are gigantic and would probably not fit in a Bottlehead Crack, whereas the Goldpoint and Valab do.
> ...


 
 No not for the CRACK passive preamp.


----------



## i luvmusic 2

jamiemcc said:


> i luvmusic 2 said:
> 
> 
> > The only problem i have with the 24 steps is where 7th clicks is not loud enough and on 8th clicks too loud for me,I need something like Khozmo 48 steps but they are pricey.
> ...


 
 Is this the  one in your SEX amp?
  
 Thanks!


----------



## ZachPtheDude

i luvmusic 2 said:


> No not for the CRACK passive preamp.




Interesting. Another bottlehead kit or something else?


----------



## JamieMcC

i luvmusic 2 said:


> Is this the  one in your SEX amp?
> 
> Thanks!


 

 Yes its the same as used in my Sex, I have fitted them to a couple of amps so far and the first thing I used one in was a home made passive pre. First assembling one using the metal films selected from their option page which by the way looked identical to those in my Valab these worked well enough but for the Sex I wanted to push the boat out and ordered the RN55 Dales from mouser. Using the list of values that comes in the nice little instruction book which comes with the A5.
  
 I used a spare Crack enclosure to mount it in which was a tight fit width ways think I had to sand a fraction of the end of the pcb to get it to fit but can not actually remember. I ended up cannibalising the pre amp to use the attenuator in another amp build.
  
 I was eager to see how it sounded so in pic of the passive pre below the input selector switch is missing but I also purchased the Select 5 pcb based switch from same people http://glass-ware.stores.yahoo.net/select5.html to use for the selector switch.


----------



## Doc B.

Just to add a little anecdotal info to this discussion -

A couple years ago I wanted to upgrade the attenuators in our premium kits. At the time we were developing the BeePre 300B preamp. We modularized the preamp protoyping setup as much as possible so we could make changes to one part and listen. And so the attenuator was in its own box and thus easily changed out.

We tried some commercial stepped attenuator designs including our own Sweetest Whispers and other much more expensive designs, along with transformer attenuators and a few different pots of carbon and plastic composition. 

Interestingly the attenuator that stood out in these comparisons as the cost effective choice was the Blue Velvet. It was better to our ears than everything but the Sweetest Whispers. And so from there we decided that, to get the best sound we could, we would have to develop a new attenuator of our own design. It uses very well made switches and Dale resistors with values worked up by Paul Birkeland. It's clearly better to my ear than the Blue Velvet, but it costs a heckuva lot more and would not fit in a Crack.

I don't know if the one I got was a fluke or if they all sound the same (PB thinks it's a counterfeit), but I still keep that Blue Velvet in a box around as an easy to add attenuator that doesn't color the sound.


----------



## i luvmusic 2

jamiemcc said:


> i luvmusic 2 said:
> 
> 
> > Is this the  one in your SEX amp?
> ...


 
 I just ordered the A3.
 Thanks!


----------



## i luvmusic 2

I don't know why i'am thinking of making a passive preamp while my CRACK and the SEX are not Working.
	

	
	
		
		

		
		
	


	



  
 Time to fix those things when i get home tomorrow then maybe next a couple of weeks work on the Preamp............... more work.


----------



## JamieMcC

i luvmusic 2 said:


> I just ordered the A3.
> Thanks!


 
  
 The A3 looks interesting as its more compact and also adds a small amount of balance control and should work nicely with a amp like the Sex and a speaker set up. Looking forward to hearing more about it later on.


----------



## Grado77

doc b. said:


> Just to add a little anecdotal info to this discussion -
> 
> A couple years ago I wanted to upgrade the attenuators in our premium kits. At the time we were developing the BeePre 300B preamp. We modularized the preamp protoyping setup as much as possible so we could make changes to one part and listen. And so the attenuator was in its own box and thus easily changed out.
> 
> ...


 

  Doc,
  
 I just installed the popular PEC pot......are you saying the BV is better? The ALPS is cheap enough I may just have to order one (but where to find a real one is the question?).
  
 The PEC is unbalanced on the bottom and it has a hair of slop to it. You can feel it slightly catch when turning either direction (yes the screw is tight as can be)
  
 I guess it sounds great but I thought the stock pot wasn't bad at all.


----------



## Doc B.

I'm saying yes, the Blue Velvet sounded better to me than a PEC in my system. But I may also be saying that you do not want a real one, you may want the fake. I'm not sure what about it made Peebs decide it's fake.


----------



## i luvmusic 2

They are nice indeed (ALPS BLUE VELVET)i used 4 of them and one extra that i used to experiment i got mine from Parts Connexion i hope they are real.


----------



## NightFlight

zachpthedude said:


> A Khozmos in a crack? You would have to make a much larger housing for the crack, and probably use a 12 x 12 inch plate at the least. That'd be a huge piece of crack


 
  
 I have a 48 position Khozmo shunt type stuffed in my Crack.  I had to get creative with the left channel (assuming left) current regulator board. I got some jointed mounting pegs and the stiffness of the wires keep it in place. The crack doesn't move in its rack, so its fine that way.  I can't remember if I ever got around to posting pics of that mod.


----------



## ZachPtheDude

nightflight said:


> I have a 48 position Khozmo shunt type stuffed in my Crack.  I had to get creative with the left channel (assuming left) current regulator board. I got some jointed mounting pegs and the stiffness of the wires keep it in place. The crack doesn't move in its rack, so its fine that way.  I can't remember if I ever got around to posting pics of that mod.




Would love to see pics of that.


----------



## bigfatpaulie

nightflight said:


> I have a 48 position Khozmo shunt type stuffed in my Crack.  I had to get creative with the left channel (assuming left) current regulator board. I got some jointed mounting pegs and the stiffness of the wires keep it in place. The crack doesn't move in its rack, so its fine that way.  I can't remember if I ever got around to posting pics of that mod.


 
  
 I'd be curious to see it to.  Any chance you would bring it to the meet (whenever it is)?


----------



## NightFlight

Not as badly stuffed as some I've seen (Jamie)
  
  

  
 Ladder - not shunt. My bad. 
  

  

  
  
  
 Just playing around with the camera.


----------



## NightFlight

bigfatpaulie said:


> I'd be curious to see it to.  Any chance you would bring it to the meet (whenever it is)?


 
  
 I hope to.


----------



## Grado77

doc b. said:


> I'm saying yes, the Blue Velvet sounded better to me than a PEC in my system. But I may also be saying that you do not want a real one, you may want the fake. I'm not sure what about it made Peebs decide it's fake.


 
  
 I wonder how many different fakes there are .... now to hunt for the best of the mutha-fakers..........
  
 did you remember if your fake has lugs?


----------



## JamieMcC

nightflight said:


> Not as badly stuffed as some I've seen (Jamie)
> 
> 
> 
> ...


 
  
 I see from your pictures the Khozmo also uses the Dale RN55 for its resistors


----------



## ZachPtheDude

Those Mundorfs make the Solens I have look even bigger than they are, lol.


----------



## lextek

Anyone move from HD600s to HD800s? What can be expected? I love my Crack/Speedball/HD600 combo. Always wondering though.


----------



## bigfatpaulie

I did exactly that.  I LOVED the HD600 + Crack but I wanted the bigger sound stage and more detail.  
  
 I know I am in the minority here, but I *hated *the HD800's and the Crack (Speedball, Mundorf caps, Blue Velvet Pot, Telefunken ECC83, Tung Sol 5998).  I was actually going to return the HD800's because I 100% preferred the HD600 to the HD800's.  A fellow head-fi'er talked me out of it.  The HD800's have rich blood and to sound right (to me) they something pretty major behind them.  My analogy (despite it not being perfect) is the HD800's are like a Ferrari F60.  It's really an amazing thing.  But put the wrong tires, fuel and oil on/in it, however, and it's a mess.  You're better off with a less expensive car with the right tires, fuel and oil.  It wasn't until I upgraded my amp that I fell in love with the HD800's.  Having lived with both setups for a long time now the HD600 + Crack still very well holds its own and it has lost nothing when it come to an enjoyable listed.  What you already have is a really special combination.
  
 But that's me, IMHO, YMMV, etc etc etc.  Many others here would strongly disagree and that's okay, to each their own.  But that was my experience.


----------



## Mich4lle

Hello All,
  
 So I was looking around on Ebay for a stepped attenuator and I found one that looks great but I don't know much about it and cannot find more information about it, I was wondering if any of you have any experience with it?
 I don't know what it is called but here is a picture of it:

 It looks fantastic and has a pretty hefty price at $179
 Here is the link: http://www.ebay.com/itm/Stepped-attenuator-STEREO-48-steps-Volume-control-/121337752812?pt=LH_DefaultDomain_0&hash=item1c404b2cec
 Any feedback would be great. Oh and does anybody no of a good place other than Ebay to find 5998 tubes?


----------



## Zashoomin

mich4lle said:


> Hello All,
> 
> So I was looking around on Ebay for a stepped attenuator and I found one that looks great but I don't know much about it and cannot find more information about it, I was wondering if any of you have any experience with it?
> I don't know what it is called but here is a picture of it:
> ...


 
 That, my friend is a khozmo stepped attenuator.  I don't know if that is a real one or a knockoff, so I think you are better suited to spend the same amount of money on their official website.  http://www.khozmo.com/products_dale_shunt.html  The pictures don't match up because that is the mkII and the ones on the website are mkI.  Rest assured though he will send you a MKII. It is one of the few stepped attenutators that will give you 48 steps instead of 24 and they seem to be well built.  I have one on order right now.  If you can wait about a week or so for it to arrive I can tell you exactly what I think about it.  
  
 Edit:  It is the same one that NightFlight used in his crack just a few posts up.  Again though that is the MKI.  Also forgot to mention that there are upgrade options if that is your kind of thing as well.


----------



## hdtv00

Ok hey everyone. I just bought this for $520 on forum here is it ok price and what not.
  
 "sale includes the new Crack amp with speedball. Walnut stain and poly on the wood base, painted bell and power transformer, painted retainer ring on the power tube, solid milled aluminum volume knob and some of the best soldering work on any Crack that I've seen. Right angle power cord and RCA connectors also included. Stock tubes. I did not build this amp. It was built by an experienced crack builder that happens to live near me. 
  
 At my request the builder added the resistor mod as specified on the Bottlehead forum. This allows the knob to swing up towards11-12:00 and be nice and full without being deafeningly loud. The mod also eliminate channel imbalance problems when listening at low levels. 
  
 For $75 extra I can include a near mint NOS Tung Sol 5998 and Telefunken 12au7 that make the best pair of tube I've ever heard on the Crack, period.  Both tubes are perfect performers and have no noise or microphonics."
  
 I have been browsing the forums for a tube amp for my Senn HD 700,650 and 560 Ovation II's for years. FINALLY bought what I posted about for $520 as I said. I figured with the mods and extra tubes it was ok price, shipped.
  
 I'll be using an Aune T1 for a DAC to it for now but might upgrade that down the road I haven't researched that part yet. I really just kinda caved in after missing that Lyr listing with $180 worth of telefunken tubes with it for $330 or whatever it was I forget.
  
 Anyway have a lot of reading to do through this thread now that I own one and I can't wait to hear a proper amp after all these years. I've never really listened to any of my headphones with a proper amp ever, I've only used the Aune T1 which isn't anywhere near a proper amp I'm sure. This should be intersting to say the least.


----------



## DDDamian

hdtv00 said:


> Ok hey everyone. I just bought this for $520 on forum here is it ok price and what not.




One can always debate price, but at least for your 650's I'd say you'll be very happy. Just the work that's gone into it with the ugrades and walnut base justifies the price, and you now own a very sweet amp. I'm sure others can comment on the pairing with the other cans, but once you receive it and give it a go I think you'll be very happy with he purchase.


----------



## Mich4lle

zashoomin said:


> That, my friend is a khozmo stepped attenuator.  I don't know if that is a real one or a knockoff, so I think you are better suited to spend the same amount of money on their official website.  http://www.khozmo.com/products_dale_shunt.html  The pictures don't match up because that is the mkII and the ones on the website are mkI.  Rest assured though he will send you a MKII. It is one of the few stepped attenutators that will give you 48 steps instead of 24 and they seem to be well built.  I have one on order right now.  If you can wait about a week or so for it to arrive I can tell you exactly what I think about it.
> 
> Edit:  It is the same one that NightFlight used in his crack just a few posts up.  Again though that is the MKI.  Also forgot to mention that there are upgrade options if that is your kind of thing as well.




It would be great if you let me know what you think of the sound, because it looks great, but that doesnt really meam much about its sound. And I guess it is a good idea to rather get it from the actual supplier. 

I am still curious about a good place to get great condition 5998 tubes that isn't from EBay. I would rather pay a bit more and get a tube that I know will work for a while, or is reliability not a problem for the Tung-sol tube? This question is obviously directed at everyone.


----------



## JamieMcC

mich4lle said:


> It would be great if you let me know what you think of the sound, because it looks great, but that doesnt really meam much about its sound. And I guess it is a good idea to rather get it from the actual supplier.
> 
> I am still curious about a good place to get great condition 5998 tubes that isn't from EBay. I would rather pay a bit more and get a tube that I know will work for a while, or is reliability not a problem for the Tung-sol tube? This question is obviously directed at everyone.


 
  
  
 Firstly I will comment of the RN55 Dales they are the only type of resistor I have tried so far that I am unable to tell if they change the sound of the amp through my headphones often using other less expensive resistors you can make out subtle differences/characteristics after fitting or removing them from the signal path. 
  
 Comparing my Valab attenuator against the attenuator with RN55's the differences are very subtle and perhaps even subjective but I like what I am hearing (or should that be what I am not hearing) with RN55 the Valab is around $20 and imo is a one of the best value upgrades for the Crack you can get.
  
 The Valab in comparison to the stock pot is increased resolution and clarity and low level listening is balanced. The draw back of fitting the Valab is the amount of steps is limited to 23 so you do not have the fine tuning of the volume level the stock pot or a 36 step attenuator would give.
  
 But If you are running a pc based system and can attenuate the level of the music you listen to with your software volume slider on the media player you use then finding the sweet spot with the Valab's 23 steps should not be a problem.
  
 One of the things to consider is that if fitting a high quality attenuator how much benefit will it give you in your system and is the rest of your system going to limit the perceived performance of the new attenuator.
  
 Something like the Alps blue velvet or Valab is going to bring a noticeable improvement over the stock pot for not much outlay the savings made with going for these less expensive but still very good options is that there will be money left over for say the 5998, film output caps etc .These I suspect in combination will give a greater improvement than just a more expensive attenuator on its own.


----------



## Doc B.

Clarification: number of steps does not = how "fine" you can tune the level. That is determined by the amount of attenuation per step. As an example a 23 step attenuator with 1.5dB steps will have double the step resolution of a 36 step attenuator that is 3db per step.


----------



## JamieMcC

doc b. said:


> Clarification: number of steps does not = how "fine" you can tune the level. That is determined by the amount of attenuation per step. As an example a 23 step attenuator with 1.5dB steps will have double the step resolution of a 36 step attenuator that is 3db per step.


 
  
 Yes of course you are right doc and there needs to be a balance found between individual step resolution and the total range of resolution available and this is a consideration when using the stepped attenuators. But if a 24 and 36 step attenuator are both equal in their total range of attenuation it is highly probable the 36 step will offer finer increments. Which was what I was trying to get across in my ham fisted way.


----------



## NightFlight

bigfatpaulie said:


> I did exactly that.  I LOVED the HD600 + Crack but I wanted the bigger sound stage and more detail.
> 
> I know I am in the minority here, but I *hated *the HD800's and the Crack (Speedball, Mundorf caps, Blue Velvet Pot, Telefunken ECC83, Tung Sol 5998).  I was actually going to return the HD800's because I 100% preferred the HD600 to the HD800's.  A fellow head-fi'er talked me out of it.  The HD800's have rich blood and to sound right (to me) they something pretty major behind them.  My analogy (despite it not being perfect) is the HD800's are like a Ferrari F60.  It's really an amazing thing.  But put the wrong tires, fuel and oil on/in it, however, and it's a mess.  You're better off with a less expensive car with the right tires, fuel and oil.  It wasn't until I upgraded my amp that I fell in love with the HD800's.  Having lived with both setups for a long time now the HD600 + Crack still very well holds its own and it has lost nothing when it come to an enjoyable listed.  What you already have is a really special combination.
> 
> But that's me, IMHO, YMMV, etc etc etc.  Many others here would strongly disagree and that's okay, to each their own.  But that was my experience.


 
  
 Thanks, that gives me much hope for the Mainline.  
  
 I for one have tried the HD600's and HD800's side by side with my amp and another at a meet last year. The meet worked out that myself and Greyhorse got to be the bottlehead table.  Also, I brought a bunch of tubes to try. 
	

	
	
		
		

		
			





  In our case we both agreed that the 5998 was the biggest change overall in terms of tube and for the better. We also both preferred the 800's, but more so with the 5998. The HD800 seems to (sort of) slurr with the RCA 6080.  Greyhorse really wanted to buy my 5998 on the spot. I had to say no a few times... and even keep a close eye on it (jokingly of course!) I'm convince someone sprinkled pixie dust on mine because the WE-421A at least to my ears... had nothing on it but a bit of screech.
  
 Having started out with the 800's the test of the 600's was kind of a shock for me. Like a bit of a step backward. 
  
 So while having found different preferences as you stated above, I still think the Mainline is likely to bring out more of the best out of the 800s. That's the hope anyhow.


----------



## NightFlight

My brother also gave me this Alps pot with the bag of goodies the Khozmo came in (wire/caps/pots/heat shrink). I just noticed it's a switched pot as well.. I'm guessing its supposed to be okay too.
  

  

  
  
 Not certain what all the pins are.
  
 Edit: Wait. Bottom row(in) is Left, Ground Right Ground. Top row is out. 
 Edit: Hey, it IS a blue velvet. That's what I get for posting without googling first.


----------



## Mich4lle

jamiemcc said:


> But If you are running a pc based system and can attenuate the level of the music you listen to with your software volume slider on the media player you use then finding the sweet spot with the Valab's 23 steps should not be a problem.


 
  
 Oh Okay, I didn't realise that if you are running the crack through a PC that the balance issues at low volumes is not a problem. So does this mean that if I run my Crack through a DAC then I don't necessarily have to spend money on a fancy Attenuator? Will I see any improvement over the stock volume pot at all?


----------



## JamieMcC

mich4lle said:


> Oh Okay, I didn't realise that if you are running the crack through a PC that the balance issues at low volumes is not a problem. So does this mean that if I run my Crack through a DAC then I don't necessarily have to spend money on a fancy Attenuator? Will I see any improvement over the stock volume pot at all?


 

 I doubt you will see any improvement in sonics if using stock pot but you should be able to over come low level channel imbalance this way that is if you are experiencing any in the first place.


----------



## Jeb Listens

Hi all!

I've had a Crack kit in the top of my wardrobe for a couple of months now. When I received it I was pretty busy and still enjoying my other amps so tucked it away for calmer times.

When I received it I was very enthusiastic. Over the last few weeks i guess I've become a bit daunted by the thought of undertaking the build. I don't have any DIY electronics experience. Just wondering if other people felt this way and how they found the process?

Jeb.


----------



## bigfatpaulie

nightflight said:


> Thanks, that gives me much hope for the Mainline.
> 
> I for one have tried the HD600's and HD800's side by side with my amp and another at a meet last year. The meet worked out that myself and Greyhorse got to be the bottlehead table.  Also, I brought a bunch of tubes to try.
> 
> ...


 
  
  
 The Mainline is a top shelf amp and anyone would be lucky to have it.  The Mainline has a very different in signature VS the Crack, however.  The Crack is warmer sounding and what one would more expect from an OTL amp.  The Mainline is much more transparent a neutral and leaves the Crack in the dust in virtually every technicality you can imagine.  It's just fantastic with the HD800's and it will certainly elevate your HD800's by leaps and bounds.


----------



## dsound

jeb listens said:


> Hi all!
> 
> I've had a Crack kit in the top of my wardrobe for a couple of months now. When I received it I was pretty busy and still enjoying my other amps so tucked it away for calmer times.
> 
> ...


 

 Hey there.  The documentation is top notch so I wouldn't worry.  Just remember to go slow and make sure you have good solder-joints.  Also, the Bottlehead forum members are extremely helpful with troubleshooting should the need arise.


----------



## bigfatpaulie

jeb listens said:


> Hi all!
> 
> I've had a Crack kit in the top of my wardrobe for a couple of months now. When I received it I was pretty busy and still enjoying my other amps so tucked it away for calmer times.
> 
> ...


 
  
 Just take your time and you'll be fine


----------



## JamieMcC

jeb listens said:


> Hi all!
> 
> I've had a Crack kit in the top of my wardrobe for a couple of months now. When I received it I was pretty busy and still enjoying my other amps so tucked it away for calmer times.
> 
> ...


 
  
 I felt the same way when my kit first arrived when you haven't done any soldering or even used a multimeter before it can very daunting.  I practised my soldering first on a few scraps of wire I had lying around which helped get my confidence up along with watching Tyll Hertsens Crack build video for help full tips I actually stopped mid build a couple of times to watch the video again.
  
 Because each step of the build is covered not only by written instructions but also with lots of pictures having the visual reference makes following any confusing bits much easier.   
  
 Take your time read and check each step before going to the next and before you know it you will be enjoying the build and have a great sounding Crack at the end. If you get stuck or just want a little confirmation on anything just post a message on the Bottlehead forum and the Bottlehead team will soon get back to you.
  
 Good to see another UK based builder.


----------



## Jeb Listens

Thanks for the encouragement and suggestions, guys - I'll give it a go soon.
  
  I think in part it was all the safety stuff at the start of the manual that gave me cause to worry a bit!  Obviously - that's probably the point (to really make you stop, take note and think about consequences) and it's vitally important stuff.   I'm very cautious and like to be very precise, so I'll just go very slowly and try and enjoy the process.
  
 Jeb.


----------



## JamieMcC

jeb listens said:


> Thanks for the encouragement and suggestions, guys - I'll give it a go soon.
> 
> I think in part it was all the safety stuff at the start of the manual that gave me cause to worry a bit!  Obviously - that's probably the point (to really make you stop, take note and think about consequences) and it's vitally important stuff.   I'm very cautious and like to be very precise, so I'll just go very slowly and try and enjoy the process.
> 
> Jeb.


 
  
 Hi Jeb I would also suggest breaking the build down into sections and not trying to hook it all up in a marathon session.


----------



## Jeb Listens

jamiemcc said:


> Hi Jeb I would also suggest breaking the build down into sections and not trying to hook it all up in a marathon session.


 

 Cool, thanks Jamie, I will do just that.   My current headphones are LCD-2s, which I understand are not really suitable for the Crack.  So as well as a soldering iron i'll need to get some headphones too! -  I guess it just comes down that that age-old choice between the HD600 and HD650 -  any pointers there? HD600 more neutral and 650 a bit warmer - correct?  
  
 Jeb.


----------



## mordicai

I bought a lot of tubes and many were from eBay. My current 5998 is from eBay. I have never gotten a DOA tube on eBay but I try to be careful who I buy from. Most reputable sellers will accept a return and I have returned tubes twice with no problem. Paid about $50 for my 5998 about a year ago and $12 for a mullard 12at7 that I am listening to now with the Stereomour. Fabulous tube


----------



## stupidmop

jeb listens said:


> Hi all!
> 
> I've had a Crack kit in the top of my wardrobe for a couple of months now. When I received it I was pretty busy and still enjoying my other amps so tucked it away for calmer times.
> 
> ...


 
 I loved building the kit. The voltage checks I wouldn't do again for anything. That's why I put up with the channel imbalance and horrible gain spikes from the pot. I have a blue velvet and a very nice stepped attenuator setting on my desk but will never be installed unless my electrician buddy will do the checks for me. IMO this is NOT a beginner's kit. Again IMO,YMMV!


----------



## NightFlight

bigfatpaulie said:


> The Mainline is a top shelf amp and anyone would be lucky to have it.  The Mainline has a very different in signature VS the Crack, however.  The Crack is warmer sounding and what one would more expect from an OTL amp.  The Mainline is much more transparent a neutral and leaves the Crack in the dust in virtually every technicality you can imagine.  It's just fantastic with the HD800's and it will certainly elevate your HD800's by leaps and bounds.


 
  
 Well, after having built the Crack I'm looking forward to just the process of building. Even better now that I'll have a good amp to listen to along the way.  I kind of built the Crack in a rush and I feel I could have done some of the connections with a better certainty.


----------



## NightFlight

stupidmop said:


> I loved building the kit. The voltage checks I wouldn't do again for anything. That's why I put up with the channel imbalance and horrible gain spikes from the pot. I have a blue velvet and a very nice stepped attenuator setting on my desk but will never be installed unless my electrician buddy will do the checks for me. IMO this is NOT a beginner's kit. Again IMO,YMMV!


 
  
 Well, just use an alligator clip to the meter ground lead and poke around with positive, keep your left in your pocket and never hold the chassis when checking because that is grounded. While aluminum is only %60 as conductive as copper it only take a little bit. That and watch the angle of your probe when you come in to press against a point. 
  
 Once you get comfortable with the above.... (that's both good and bad) - your fairly safe.


----------



## stupidmop

I did. Fried my transformer. I was just giving a word of caution, he asked for opinions I gave mine. Bottlehead were excellent with their customer service. They fixed it for me because I refuse to do the checks again. I know, I'm a wuss. But the loud pop and fried tube were enough to convince me it was above my skill level. I'm very good with an iron just not a meter  I'm glad everyone has a great experience and is good with a probe meter, it just ain't me. I LOVE the amp. I've just reserved my upgrades to tube rolling which has afforded me hundreds of hours of audio bliss. Don't mean to offend anyone these are just my opinions.


----------



## bigfatpaulie

nightflight said:


> Well, after having built the Crack I'm looking forward to just the process of building. Even better now that I'll have a good amp to listen to along the way.  I kind of built the Crack in a rush and I feel I could have done some of the connections with a better certainty.


 
  
 I had a similar experience.  I built my Crack pretty quickly and I should haven taken my time and enjoyed the build more.  I was yearning to build again hence the Mainline (lord knows I did not need ANOTHER amp!).  The Mainline is a really fun build like the Crack just with many, many more steps.  It really hit the spot for me.  I was worried it would be a difficult build but the manual is so top notch it really isn't any harder than the Crack.  Looks like you and Jamie will be building Mainlines at a similar time.  There is going to be some good reading 'round these parts soon!


----------



## NightFlight

stupidmop said:


> I did. Fried my transformer. I was just giving a word of caution, he asked for opinions I gave mine. Bottlehead were excellent with their customer service. They fixed it for me because I refuse to do the checks again. I know, I'm a wuss. But the loud pop and fried tube were enough to convince me it was above my skill level. I'm very good with an iron just not a meter  I'm glad everyone has a great experience and is good with a probe meter, it just ain't me. I LOVE the amp. I've just reserved my upgrades to tube rolling which has afforded me hundreds of hours of audio bliss. Don't mean to offend anyone these are just my opinions.


 
  
 Hmm. I shorted out my 6080 across an output pin and and its neighbour during some checks. Luckly it survived. Tubes are pretty tough. But it did scare me!


----------



## Rocketman248

Just put a few wraps of electrical tape around the probe so just the tip is exposed.  Much less risk of touching something you're not supposed to.


----------



## mordicai

Radio Shack sell a set of leads that only have a tiny point exposed unless you slide a covering piece back. 10 bucks I think.


----------



## Jeb Listens

Thanks guys - It was indeed the voltage check stuff in the manual that worried me a bit so those are great tips.


----------



## NightFlight

Welp. I'm now in the 'power cord makes a difference' camp. Went from 18 to 14AWG. I don't know if its the dielectric, or the fact that I DeoxIT cleaned the power cable contacts.. It made enough of a difference that my eyebrows nearly left my skull.  This unbeliever has heard the flock. IMHO power cords and connectivity are just as important as any other aspect. 
  
 Re-discovering the music. Again.


----------



## bigfatpaulie

nightflight said:


> Welp. I'm now in the 'power cord makes a difference' camp. Went from 18 to 14AWG. I don't know if its the dielectric, or the fact that I DeoxIT cleaned the power cable contacts.. It made enough of a difference that my eyebrows nearly left my skull.  This unbeliever has heard the flock. IMHO power cords and connectivity are just as important as any other aspect.
> 
> Re-discovering the music. Again.


 
  
 I agree.  When I upgraded my power I noticed a very positive change with my tube amps.  My SS amp did not benefit as much.  In my condo, however, I know I have really bad power that fluctuates between 115 and about 125 constantly.  The regenerator fixed that.  It also lowered the noise floor and eliminated the ghosting sound I was getting.
  
 I went through the same surprise when I upgraded my interconnects.  I bought them (to be totally honest) because I wanted cool interconnects.  Trevor at Norne built them for me and they replaced Blue Jeans cables.  I was expecting no change but to my ears and surprise I felt there was.  Oddly enough I find it impacted my SS amp more than my tube amp.  Go figure.


----------



## i luvmusic 2

When i was in Middle East doing some work i saw some of  this i should have take some for my amp.


----------



## GrindingThud

That may need to be burned in a bit longer than usual....



i luvmusic 2 said:


> When i was in Middle East doing some work i saw some of  this i should have take some for my amp.


----------



## DDDamian

grindingthud said:


> That may need to be burned in a bit longer than usual....


----------



## i luvmusic 2

grindingthud said:


> That may need to be burned in a bit longer than usual....
> 
> 
> 
> ...


 
 Good to know,Thanks!


----------



## PETEREK

I just ordered my Crack + Speedball kit! Looking forward to the build.


----------



## krikor

peterek said:


> I just ordered my Crack + Speedball kit! Looking forward to the build.


 
 Congrats cCasper! Perhaps we'll have two in rotation at our next Michigan Meet. Good to see you last Saturday, and wish I had a chance to listen to your modded DT-770s, but time ran out (someone else was using the headphones everytime I tried).
  
 Let me know how it goes with the build, and let me know you need any help. I found it a little confusing doing a fresh build with the Speedball upgrade (since it is written assuming your Crack is already built), but not to bad if you take it slow and be methodical. Look me up if you make it back to the east side of the mitten.


----------



## PETEREK

krikor said:


> Congrats cCasper! Perhaps we'll have two in rotation at our next Michigan Meet. Good to see you last Saturday, and wish I had a chance to listen to your modded DT-770s, but time ran out (someone else was using the headphones everytime I tried).
> 
> Let me know how it goes with the build, and let me know you need any help. I found it a little confusing doing a fresh build with the Speedball upgrade (since it is written assuming your Crack is already built), but not to bad if you take it slow and be methodical. Look me up if you make it back to the east side of the mitten.



I'm sure we'll have another meet in the next 6 months or so. I'm building the whole thing. The PDF looks pretty straight forward, I have soldered plenty so I think I will be alright. I'll look you up if I have any issues though. Maybe it would be best to do the Crack and the just do the speedball upgrade afterwards?


----------



## krikor

peterek said:


> I'm sure we'll have another meet in the next 6 months or so. I'm building the whole thing. The PDF looks pretty straight forward, I have soldered plenty so I think I will be alright. I'll look you up if I have any issues though. Maybe it would be best to do the Crack and the just do the speedball upgrade afterwards?


 
 If you want to compare with and without, definitely do it that way (obviously). What I did was go through the Crack manual and mark it up/delete all the items that were replaced or changed by the Speedball. I still have the instructions, so I can send you a copy of my marked up version. There was some wiring I changed/simplified by doing the Speedball as part of the initial build.


----------



## NightFlight

peterek said:


> I'm sure we'll have another meet in the next 6 months or so. I'm building the whole thing. The PDF looks pretty straight forward, I have soldered plenty so I think I will be alright. I'll look you up if I have any issues though. Maybe it would be best to do the Crack and the just do the speedball upgrade afterwards?




Build the Crack. Enjoy the crack. Add the speedball. Enjoy more crack.


----------



## bigfatpaulie

nightflight said:


> Build the Crack. Enjoy the crack. Add the speedball. Enjoy more crack.


 
  
 You crack me up!


----------



## NightFlight

bigfatpaulie said:


> You crack me up!


 
  
 My haiku:
  
 Build crack and listen.
 Add speedball for improvement.
 Listen and enjoy.
  
 Bah. That's terrible.


----------



## i luvmusic 2

Build it STOCK listen to it for awhile then do the upgrade.
  
 Trouble shooting a modded CRACK is a PITA.


----------



## jbarnhardt

i luvmusic 2 said:


> Build it STOCK listen to it for awhile then do the upgrade.
> 
> Trouble shooting a modded CRACK is a PITA.


 
 +1
  
 Yes, it really is much better to do the initial build, verify everything is working perfectly (and listen to it a bit!) and then go back and add the Speedball. It's not a very difficult addition. Even if you are very comfortable with your assembly skills, there is always the chance that a component or tube or something is flaky, and you will have a much more difficult time troubleshooting or getting troubleshooting support on the Bottlehead forum for a kit that has already had the Speedball installed (without first verifying 100% operation of the base kit). There is a good reason the Bottlehead folks strongly recommend that everyone assemble and test the base kit by itself before doing any additions/mods.
  
 Enjoy your kit, it's a very fun build and the sound is fantastic. The DT770s sound great with the Crack.
  
 -John


----------



## NightFlight

Yes indeed. 
  
 If you were to encounter an issue down the road with the full crack/speedball kit completed, removing part or all of the speedball can be a good troubleshooting step.  This is depending on the nature of the issue and how long it has eluded you of course.  I had a troublesome issue that I was only able to track down only by removing the C4S boards from the power tube section and dropping the cement resistors back in.  My problem went away and it immediately told me a CS4 board component was at fault.  Turned out to be a bad transistor that would flake once up to temperature! But I never would have gotten there without that isolation step. Thank you PB! 
  
 So, it is also true during the building process. Best to take it slow. Besides, the mod to drop in the two sets of boards is actually pretty trivial.


----------



## PETEREK

I ordered 3 feet of Black Dragon cable to replace the stock wire that comes with the kit, just for fun. I know the stock cable is solid core 20awg, and Black Dragon is 21.5awg, but it's insulated and will hopefully prevent some crosstalk. I'm not the biggest believer in upgrade cable, but I've been wanting to work with Black Dragon for a while now, and since it's only 3 feet (probably more than I need) the cost isn't too high. It was like $42 shipped. It should bump the value up though, some people believe in the upgrade cable. I mainly build cables for looks and convenience (length, termination, etc.)


----------



## hdtv00

So I finally broke down and have joined the club. Here is my setup now.

  

  

 Many more of my pics here.. https://www.flickr.com/photos/hdtv00/sets/72157651442294571/ if anyone is interested.
  
 So that's a Aune T1 for DAC into the crack w/speedball. And I'm sooooo confused now...
 Ok so I have Senn HD 560 Ovation II's(which lacked bass), HD 650's that I thought were to muddy even yea sure it's very slight to much mids, and HD 700 which were clearly to bright. Now explain to me how this setup fixed every single issue I had with each pair of headphone. I LOVE them all now, seriously. 560 has more bass it's just wonderful. The 650's have great clear highs now that work better with the mids and bass is just fine. And somehow the 700's aren't a harsh mess anymore. I liked these the least but now I don't hear that harshness they had. What the hell is going on here, am I just drinking the cool-aid or what...I'm so confused. I have a Orange globe in the T1, NOS Tung Sol 5998 and Telefunken 12au7 in the crack.
  
 Either way at times , which is most of the time it sounds AMAZING. I now get why Miles Davis Kind of Blue is raved about, I seriously have people in my head now playing live instruments, amazing. And some bells and what not from Bjork stuff I've heard 1000+ times blowing my mind.


----------



## Keithpgdrb

hdtv00 said:


> So I finally broke down and have joined the club. Here is my setup now.
> 
> 
> 
> ...


 

 more importantly, you should ask yourself why you bypassed the hd-600, which is superior to all the other 3!!!!  and is sublime on the crack.


----------



## hdtv00

Because after reading about the 600  for years it seems to me to just describe exactly what the 560's sound like to me. So I didnt see the point buying exact same sound Sig I've already had for 20 yrs.


----------



## Koolpep

hdtv00 said:


> So I finally broke down and have joined the club. Here is my setup now.
> 
> 
> 
> ...




Hey, I have the same setup with different tubes on the crack. It indeed brings out the best in headphones...at least my T90 and the T1 of a friend. My HD650 should arrive today so I will test them on it soon too. I guess the crack magic really shines with high impedance Senns and Beyers.
Enjoy!


----------



## DDDamian

Congrats on the new Crack - love how the wood turned out! Enjoy it.


----------



## wareaglefan21

Planning to buy a crack/speedball in the next week or so, really looking forward to pairing it with my new HD 650s. I need to get a soldering iron or station though: does anyone know if this one http://www.circuitspecialists.com/csi-station-75.html is going to be of decent enough quality to get the job done without giving out? I was looking for something with enough power to give me the option of using lead free solder if i so choose, this claims it could handle it. It's about half the price of most decent soldering stations, which gave me pause.
  
 Thanks guys!


----------



## ZachPtheDude

wareaglefan21 said:


> Planning to buy a crack/speedball in the next week or so, really looking forward to pairing it with my new HD 650s. I need to get a soldering iron or station though: does anyone know if this one http://www.circuitspecialists.com/csi-station-75.html is going to be of decent enough quality to get the job done without giving out? I was looking for something with enough power to give me the option of using lead free solder if i so choose, this claims it could handle it. It's about half the price of most decent soldering stations, which gave me pause.
> 
> Thanks guys!




Never heard of it. I went for a Hakko FX888D soldering station and it was definitely worth every penny.


----------



## Serenitty

wareaglefan21 said:


> Planning to buy a crack/speedball in the next week or so, really looking forward to pairing it with my new HD 650s. I need to get a soldering iron or station though: does anyone know if this one http://www.circuitspecialists.com/csi-station-75.html is going to be of decent enough quality to get the job done without giving out? I was looking for something with enough power to give me the option of using lead free solder if i so choose, this claims it could handle it. It's about half the price of most decent soldering stations, which gave me pause.
> 
> Thanks guys!


 

 I went with this one and was very happy.
  
 http://www.amazon.com/Aoyue-Programmable-Digital-Soldering-Station/dp/B00BSW69LI/ref=sr_1_7?ie=UTF8&qid=1427107387&sr=8-7&keywords=soldering+station


----------



## i luvmusic 2

Is 1/2 watt resistor good enough for 20K Passive Pre amp?
  
 Thanks!


----------



## ZachPtheDude

Currently I own a pair of HD 650s but I am in the market for a cheap $50 or under) pair of high impedance headphones for my dad, he might have some crack fever! Any recommendations?


----------



## JamieMcC

zachpthedude said:


> Currently I own a pair of HD 650s but I am in the market for a cheap $50 or under) pair of high impedance headphones for my dad, he might have some crack fever! Any recommendations?


 

 If you don't mind buying used then the 250ohm or 600ohm (but harder to find) Beyer DT770 PRO may just fall into you price bracket if you are lucky but normally a little more than $50.


----------



## PETEREK

jamiemcc said:


> If you don't mind buying used then the 250ohm or 600ohm (but harder to find) Beyer DT770 PRO may just fall into you price bracket if you are lucky but normally a little more than $50.




Much more than $50. Like 3 times more at least.


----------



## JamieMcC

peterek said:


> Much more than $50. Like 3 times more at least.


 
  
 brb whoops my mistake I was thinking used in UK pounds not dollars.


----------



## FunyunBreath

Finally finished the kit I've had sitting around since last summer!
  
 This is the second Crack I've built, got a good deal on it in a group buy and wanted to build another to replace the one I've had for a few years. I took my time with it and made a few modifications right from the start:
  
 -Connex Premium tube sockets
 -Socket PCB adapters for easy soldering
 -50K Alps Blue Velvet pot (works better than 100K with the HD650 I think)
 -Cardas Quad Eutectic solder (this stuff is a dream to work with, things practically solder themselves)
  
 I'm really happy with how it came out. It sounds excellent, noise is completely non-existent, even with the volume pot at maximum. I left the speedball off for now because I want to do some A/B comparisons with my other kit that has the speedball installed.
  
 I'll post pics of the finished build too, I have something special in mind for the base


----------



## Nic Rhodes

I like the old 600 ohm AKG K240DF, my last pair was £30 delivered.


----------



## Beefy

funyunbreath said:


> -50K Alps Blue Velvet pot (works better than 100K with the HD650 I think)


 
  
 How does the value of the pot make it better for a particular set of phones? It is a voltage divider; a 50k and a 100k audio taper pot are exactly the same for all intents and purposes.


----------



## FunyunBreath

beefy said:


> How does the value of the pot make it better for a particular set of phones? It is a voltage divider; a 50k and a 100k audio taper pot are exactly the same for all intents and purposes.


 
  
 Maybe someone who's more versed in circuit theory than me can chime in here, but I think being that it's a smaller spread (50Kohm -> 0Kohm) you have a bit more range on the volume knob. On the original 100K pot, smaller adjustments change the volume a lot more dramatically than on a 50K pot (since the same range on the knob is accounting for a larger change in resistance).


----------



## Beefy

funyunbreath said:


> Maybe someone who's more versed in circuit theory than me can chime in here, but I think being that it's a smaller spread (50Kohm -> 0Kohm) you have a bit more range on the volume knob. On the original 100K pot, smaller adjustments change the volume a lot more dramatically than on a 50K pot (since the same range on the knob is accounting for a larger change in resistance).


 
  
 No, it doesn't work like that. A volume pot is a divider - so at 'half' the volume knob, approximately half of the source voltage gets through, regardless of the value of the pot. Using a different value pot doesn't just mean you can turn the volume down more or less.
  
 The only difference would arise if the pots have a different attenuation curve. But unless something is borked, or one was audio and the other linear, there will be no difference.


----------



## DDDamian

^^ this


----------



## Mich4lle

funyunbreath said:


>


 
  
 I have so much penis envy for your crack, that is the most beautiful wiring I have ever seen, well done.
 I am just curious how much of an effect that volume pot has on the sound over the stock one, it does look a lot better, but does it sound better?
 The same question goes for the tube sockets.
 But good job on the crack, it looks great.


----------



## FunyunBreath

beefy said:


> No, it doesn't work like that. A volume pot is a divider - so at 'half' the volume knob, approximately half of the source voltage gets through, regardless of the value of the pot. Using a different value pot doesn't just mean you can turn the volume down more or less.
> 
> The only difference would arise if the pots have a different attenuation curve. But unless something is borked, or one was audio and the other linear, there will be no difference.


 
  
 Good to know, thanks for posting  What would the different affects of a 25k, 50k, or 100k pot be on the system then?
  


mich4lle said:


> I have so much penis envy for your crack, that is the most beautiful wiring I have ever seen, well done.
> I am just curious how much of an effect that volume pot has on the sound over the stock one, it does look a lot better, but does it sound better?
> The same question goes for the tube sockets.
> But good job on the crack, it looks great.


 
  
 Thanks! I can't do a direct a/b test with the Alps pot vs. stock but my other Crack has a Valab 100k stepped attenuator and I don't notice much difference in clarity. I much prefer the buttery smooth tracking of the Alps pot over the hard clicks on the attenuator.
  
 The biggest reason I went with the Alps pot over the 100k stock pot is the Alps tracks perfectly at lower volumes. Whereas the stock pot had a channel imbalance until the volume is around a medium listening level. The stock pot also tends to collect dust easily and over time starts to get that scratchy sound when turned.


----------



## krikor

beefy said:


> No, it doesn't work like that. A volume pot is a divider - so at 'half' the volume knob, approximately half of the source voltage gets through, regardless of the value of the pot. Using a different value pot doesn't just mean you can turn the volume down more or less.
> 
> The only difference would arise if the pots have a different attenuation curve. But unless something is borked, or one was audio and the other linear, there will be no difference.


 
  
 Thanks for this tidbit... helps me better understand how these things work as well. 
  


funyunbreath said:


> What would the different affects of a 25k, 50k, or 100k pot be on the system then?


 
  
 I'll venture a guess that it changes the input impedance of the amp to 25k, 50k and 100k respectively. I'd also expect it to have some effect on the input tube since the pot acts as both a grid stopper resistor and grid-to-ground resistor.
  
 Caveat - I know just enough to convincingly sound like I know what I'm talking about (which really pisses my wife off), so take this with a grain of salt. I did find some good explanations of voltage dividers and grid resistors at the Aiken guitar amplifier website:
  

White papers: http://www.aikenamps.com/index.php/white-papers#
The Voltage Divider Rule: http://www.aikenamps.com/index.php/the-voltage-divider-rule
Grid Resistors - Why Are They Used: http://www.aikenamps.com/index.php/grid-resistors-why-are-they-used
  
  
_*So why does this interest me?*_
  
 Well, I've been contemplating ditching the Crack's volume pot and using an external passive attenuator (Bottlehead Submissive or the Tortuga LDR). As a trial, I've been doing this with another preamp I have on hand by simply cranking the volume pot to max to effectively bypass the pot (zero resistance in the signal path). However, I've noticed some rising static/noise at the very end of the pots travel.
  
 I live about a mile from 13,500 watt radio tower transmitting 6 different stations' signals. This has caused problems for me with other  headphones/amps (most notably the Schiit Fulla/AKG K7XX combo) in which I've been able to actually "tune in" a station well enough to hear it depending on how I arrange the cords and tilt my head.
  
 My theory... based on the white papers linked above, cranking the volume all the way up reduces what is the "grid stopper" resistance (the pot resistance that is in series with the 12AU7) to zero. Since grid stoppers "act as a very high frequency low-pass filter," I'm basically opening up my Crack up to RFI (wait, that sounds bad).
  
 Do I have these concepts correct?
  
_*The long and short of it... *_are there ideal resistor values for the input voltage divider when using the Crack amp sans volume control? I've seen it recommended at the Bottlhead forum that a simple 100k grid-to-ground resistor is all that's needed (no series grid stopper), but is this the ideal situation? Or is mine a unique situation that requires a voltage divider?
  
 Thanks.
  
 I should probably just cut to the chase post this over at the Bottlhead forum


----------



## Beefy

krikor said:


> I'll venture a guess that it changes the input impedance of the amp to 25k, 50k and 100k respectively. I'd also expect it to have some effect on the input tube since the pot acts as both a grid stopper resistor and grid-to-ground resistor.


 
  
 Yep, this. The thing that sees the biggest difference is really the source though. Some tube sources like a high impedance because they can't run a lot of current. Solid state amps are less picky.
  
 I am less sure about how the pot alters the input stage of the amp, but unless you go really crazy low it shouldn't make any audible difference. But if you want to swap out for something more boutique, definitely ask at Bottlehead......


----------



## hdtv00

Did I just score a Western Electric 421a for $175. It tested results at bottom does it look great test wise?


----------



## JamieMcC

hdtv00 said:


> Did I just score a Western Electric 421a for $175. It tested results at bottom does it look great test wise?


 
  
 If it is not a WE421a it will be Tung sol 5998 clear top from the early 50's I think? I have a couple and they look identical to my WE421a I actually prefer the clear tops and find them a bit more  musical and noticeably different to latter silver topped 5998's .


----------



## Maxhawk

I posted this on the Bottlehead forum, but there seems to be more activity here so I thought I'd repeat it.
  
 This thread (http://bottlehead.com/smf/index.php?topic=5989.131) on the Bottlehead forum describes methods to mod the Crack to optimize bias for various tube types. I had added a switch and resistors to allow use of the 12BH7 as well as E80CC/5687 but wanted something neater and consequently more reliable long-term. Here's the before shot:

  
  
 I decided to make my own PCB, integrating a DPDT switch and resistors, and condensing the dual boards into a single PCB.
 Here's the bare PCB:

  

 And stuffed with parts:

  

 Installed in place of the 2 separate boards:

  

 The first try wasn't perfect, as the mounting holes needed some dremeling to allow the PCB to clear the standoff from the other PCB. Also some of the pads are on the small side and the holes for the LEDs are too large, but it did work first time.
  
 After spending more time switching between the 12BH7, and 5687, I find that the 5687 excels in imaging and placement, but is down on bass compared to the 12BH7.
  
 I had to buy 10 pcs minimum and I've only got one Crack, so I've got extras if anyone is interested.


----------



## DDDamian

jamiemcc said:


> If it is not a WE421a it will be Tung sol 5998 clear top from the early 50's I think? I have a couple and they look identical to my WE421a I actually prefer the clear tops and find them a bit more  musical and noticeably different to latter silver topped 5998's .


 
 Interesting on the difference but maybe not surprising - tubes of the same batches may sound slightly different let alone with design differences. Here's my Tung Sol 5998 silver-topped. Love it.
  
​


----------



## FunyunBreath

5998 is a great tube, I'm really liking the Tung Sol 7236 as well. Similar, but a bit cleaner in the bass/low mids and with better imaging I think.
  

  
 On another note, as you can see I currently have 2 Cracks sitting on my desk, one speedball'd and the other not 
  
 I've been comparing each with different tube combos and surprised to find that I'm actually liking the sound of the stock crack a bit more so far. The speedball makes for a tighter sound, especially with drums and cymbals, but there's a natural reverb to the stock crack that the speedball doesn't have.
  
 Going to keep doing some tube combo shoot-outs to see whether I'm going to install the speedball in my new build or not.


----------



## DDDamian

> Going to keep doing some tube combo shoot-outs to see whether I'm going to install the speedball in my new build or not.


 
  
 Keep us posted


----------



## grausch

maxhawk said:


> I had to buy 10 pcs minimum and I've only got one Crack, so I've got extras if anyone is interested.


 
  
 I saw this on the Bottlehead forums, but since I really had no clue about the mods I did not want to comment. However, this is a great idea and definitely the cleanest way of implementing the switches that I have seen.
  
 How much wider is the pcb vs the standard Speedball pcb? Reason I am asking is I have the VALabs stepped attentuator and the Speedball will barely fit with that in there. If it needs any more space, then it will need to either to be such a pcb or the attentuator.


----------



## Maxhawk

It spans the same width at 2.75". Let me know if yours measures differently.


----------



## i luvmusic 2

maxhawk said:


> I posted this on the Bottlehead forum, but there seems to be more activity here so I thought I'd repeat it.
> 
> This thread (http://bottlehead.com/smf/index.php?topic=5989.131) on the Bottlehead forum describes methods to mod the Crack to optimize bias for various tube types. I had added a switch and resistors to allow use of the 12BH7 as well as E80CC/5687 but wanted something neater and consequently more reliable long-term. Here's the before shot:
> 
> ...


 
 NICE!


----------



## bigfatpaulie

maxhawk said:


> I posted this on the Bottlehead forum, but there seems to be more activity here so I thought I'd repeat it.
> 
> This thread (http://bottlehead.com/smf/index.php?topic=5989.131) on the Bottlehead forum describes methods to mod the Crack to optimize bias for various tube types. I had added a switch and resistors to allow use of the 12BH7 as well as E80CC/5687 but wanted something neater and consequently more reliable long-term. Here's the before shot:
> 
> ...


 
  
  
 May I be the first to extend a very warm welcome to Head-fi 
	

	
	
		
		

		
		
	


	



  
 I very much look forward to your future contributions.
  
 -Paul


----------



## Maxhawk

bigfatpaulie said:


> May I be the first to extend a very warm welcome to Head-fi
> 
> 
> 
> ...


 
 Thanks!  This is my first foray into tubes and it's been a great experience so far. It's been fascinating learning about all the different tube manufacturers and all the rebranding. I ordered way too many tubes in a short amount of time trying to figure out what kind of sound I like. I've got around a dozen input tubes and 5 output tubes.
  
 Finishing my Crack got me motivated to finish restoring a McIntosh MC240 that was gifted to me. It's done but I'm still tube rolling since the bass seems weak. One day I'll actually measure the frequency response to see if it's really rolling off the low end.


----------



## atomicbob

maxhawk said:


> Thanks!  This is my first foray into tubes and it's been a great experience so far. It's been fascinating learning about all the different tube manufacturers and all the rebranding. I ordered way too many tubes in a short amount of time trying to figure out what kind of sound I like. I've got around a dozen input tubes and 5 output tubes.
> 
> Finishing my Crack got me motivated to finish restoring a McIntosh MC240 that was gifted to me. It's done but I'm still tube rolling since the bass seems weak. One day I'll actually measure the frequency response to see if it's really rolling off the low end.


 
 Welcome.
  
 The Crack makes a great amp for the Sennheiser HD600 / HD800 and Beyerdyamic T90 / T1. I prefer using an RCA clear top 12AU7 and Tung-Sol 6AS7g, though I have begun to experiment with E80CC and have acquired a few. The Tungsram seems to work well with the Tung-Sol. I managed to acquire the Western Electric 421a. It is a silent, non-microphonic tube providing a sonic delight to the ears, though expensive and hard to find.


----------



## peanuthead

For the folks who find Crack gets too loud too fast, would putting something like Schitt Sys (passive preamp) between the source and Crack be a good possible solution?  Thoughts?


----------



## skeptic

peanuthead said:


> For the folks who find Crack gets too loud too fast, would putting something like Schitt Sys (passive preamp) between the source and Crack be a good possible solution?  Thoughts?


 
  
 A lot of people use: http://www.amazon.com/Harrison-Labs-Line-Level-Attenuator/dp/B0006N41B0/ref=sr_1_6?ie=UTF8&qid=1427595458&sr=8-6&keywords=Line+Level+Attenuator
  
 The DIY option involves adding 2 resisters in series with your inputs, and two more shunting from your pot to ground, which preserves input impedance: http://www.goldpt.com/mods.html


----------



## JamieMcC

skeptic said:


> A lot of people use: http://www.amazon.com/Harrison-Labs-Line-Level-Attenuator/dp/B0006N41B0/ref=sr_1_6?ie=UTF8&qid=1427595458&sr=8-6&keywords=Line+Level+Attenuator
> 
> The DIY option involves adding 2 resisters in series with your inputs, and two more shunting from your pot to ground, which preserves input impedance: http://www.goldpt.com/mods.html


 
  
 The resistors work perfectly for this they are a quick easy and inexpensive solution that can be reversed later if required.


----------



## PETEREK

How long did it take everyone here to receive your Crack kit? I placed my order on the 19th and haven't received anything from Bottlehead, including tracking/shipment information. That seems like quite a long time to ship a *KIT*, something that isn't even assembled.


----------



## MoatsArt

They ship them out in batches.  A wait of a few weeks is not unusual.
  
 View the exercise in patience as practice for the construction of the kit. 
  
 It's worth it.


----------



## PETEREK

moatsart said:


> They ship them out in batches.  A wait of a few weeks is not unusual.
> 
> View the exercise in patience as practice for the construction of the kit.
> 
> It's worth it.



OK well that's a relief. Thanks for that. I have terrible patience for waiting, but the build will take as long as it needs to for it to be perfect.


----------



## mordicai

Bottlehead kits normaly take around 6 weeks or longer. They clearly state that on their web site.


----------



## NightFlight

peterek said:


> How long did it take everyone here to receive your Crack kit? I placed my order on the 19th and haven't received anything from Bottlehead, including tracking/shipment information. That seems like quite a long time to ship a *KIT*, something that isn't even assembled.


 
  
 You can use this as a guideline. http://bottlehead.com/bottlehead-kit-delivery-status/
  
 That page appears to be updated every Friday at close - PST. So I wouldn't waste my time spamming it.  
  
 Patience.


----------



## Elber

peterek said:


> How long did it take everyone here to receive your Crack kit? I placed my order on the 19th and haven't received anything from Bottlehead, including tracking/shipment information. That seems like quite a long time to ship a *KIT*, something that isn't even assembled.


 

http://bottlehead.com/bottlehead-kit-delivery-status/


----------



## PETEREK

mordicai said:


> Bottlehead kits normaly take around 6 weeks or longer. They clearly state that on their web site.



I clearly skipped over that. 



nightflight said:


> You can use this as a guideline. http://bottlehead.com/bottlehead-kit-delivery-status/
> 
> That page appears to be updated every Friday at close - PST. So I wouldn't waste my time spamming it.
> Your apparent angst to a "*KIT*" leaves me scratching my head.  The fact it _is_ a kit is a big part of the attraction to the BH product line.
> ...



I'll keep an eye on it, thanks for the link. I just meant that the wait time seems long for a product that doesn't come assembled. The fact that it isn't assembled is totally fine with me, and I understand that part of the attraction, I just wonder what causes the log wait times.


----------



## mordicai

Again all of this is explained on there web site and is available tp those who put in the energy to read it.


----------



## atomicbob

peterek said:


> I clearly skipped over that.
> I'll keep an eye on it, thanks for the link. I just meant that the wait time seems long for a product that doesn't come assembled. The fact that it isn't assembled is totally fine with me, and I understand that part of the attraction, I just wonder what causes the log wait times.


 
 Bottlehead is not a huge corporation. It is a small business so they don't have a huge inventory. As such they purchase the components to assemble the kits from suppliers worldwide. There are times when the suppliers are back-ordered on components. Bottlehead has to wait for the suppliers to ship. The suppliers are waiting for the manufacturers of the components to ship. Therefore we all wait until BH has all the components to pack the kits. Considering that the performance of the BH products far exceed their modest costs, the price of waiting is small compared to a lifetime of enjoyment.


----------



## i luvmusic 2

When i ordered my crack i waited almost 6 weeks,The SEX was a little quicker  4 weeks.


----------



## NightFlight

peterek said:


> I clearly skipped over that.
> I'll keep an eye on it, thanks for the link. I just meant that the wait time seems long for a product that doesn't come assembled. The fact that it isn't assembled is totally fine with me, and I understand that part of the attraction, I just wonder what causes the log wait times.


 
  
 It's because they live on the west coast.


----------



## mordicai

If you have ever experienced Seattle traffic, you would understand why it takes them 6 weeks to get the parts.


----------



## bigfatpaulie

mordicai said:


> If you have ever experienced Seattle traffic, you would understand why it takes them 6 weeks to get the parts.


 
  
 Lol.
  
 +1


----------



## hdtv00

Watch some of this guys videos lol.
 https://www.youtube.com/channel/UC5HL3gJ0DifbloeFXoUaSrw


----------



## ohcrapgorillas

Is there a good resource for what the best tubes are for the Crack besides wading through this thread and the one on the Bottlehead forums? I just finished building mine not too long ago (have the speedball but it's not installed yet). So far I've seen that a lot of people like the RCA clear tops (also some don't), and the Tung-Sol 5998 seems to be popular as well. Thoughts?
  
 Edit: after looking up the price of a Tung-Sol 5998, I should probably be asking what the best bang-for-your-buck tube is instead. My preferred sound is clear and natural and realistic. Being used with HD650 and HD600.


----------



## FunyunBreath

ohcrapgorillas said:


> Is there a good resource for what the best tubes are for the Crack besides wading through this thread and the one on the Bottlehead forums? I just finished building mine not too long ago (have the speedball but it's not installed yet). So far I've seen that a lot of people like the RCA clear tops (also some don't), and the Tung-Sol 5998 seems to be popular as well. Thoughts?
> 
> Edit: after looking up the price of a Tung-Sol 5998, I should probably be asking what the best bang-for-your-buck tube is instead. My preferred sound is clear and natural and realistic. Being used with HD650 and HD600.


 
  
 I've been doing quite a bit of tube rolling this week and personally I'd say the best bang for the buck power tube I've got is a Sylvania JAN 6080WB. It holds its own against my Tung Sol 7236 and 5998, and costs like $10. It has slightly emphasized bass, which could be a good thing for you if you're into electronic.
  

  
 On another note, I've been having a blast tube rolling with dual Cracks. I setup an A/B switch on both headphone outputs so I can switch between amps instantly and hear the differences in my 650's. It's pretty interesting how minor some of the differences between tubes really are when you don't have the 5 min lag in between rolling the next tube.


----------



## olegausany

ohcrapgorillas said:


> Is there a good resource for what the best tubes are for the Crack besides wading through this thread and the one on the Bottlehead forums? I just finished building mine not too long ago (have the speedball but it's not installed yet). So far I've seen that a lot of people like the RCA clear tops (also some don't), and the Tung-Sol 5998 seems to be popular as well. Thoughts?
> 
> Edit: after looking up the price of a Tung-Sol 5998, I should probably be asking what the best bang-for-your-buck tube is instead. My preferred sound is clear and natural and realistic. Being used with HD650 and HD600.



You will never regret buying 5998


----------



## ZachPtheDude

I am using a Thomson CSF 6080WA with an RCA clear top 12AU7. Just finished building my crack, installed a choke and replaced the coupling caps with 100uf Solen film caps. I have a load of different NOS small value caps so I think after a solid 3 to 4 weeks with the crack as it is now I'll try bypassing different capacitors.


----------



## hdtv00

My newest adventure ..
 Well excited as usual I'll bring some life into this thread haha. Just won auction for a Western Electric 421A that does have it's writing clear enough to tell it's legit. Described as
 "This may be the ugliest Western Electric tube I have ever had.  The base is dirty and most of the writing is gone - I have not cleaned it for fear of removing what writing is there.  This is a 421A Dual Triode in excellent working condition.  I cannot read the date code.  It is a black plate version.
 My Hickok tester decided to completely stop working recently,  so I tested this on a B&K that give your percentage of mutual conductance spec.  Both triodes on this one test identical at 120% of spec when tested as a 6AS7.  No gas, no shorts.
 I will guarantee this tube to be good,  but will leave it to the new owner to clean it up.  This is a good way to get an excellent sounding tube a a very good price."
 Got it for $197.50 shipped. That's at least decent yeah? Any thoughts or worries anyone.


----------



## skeptic

ohcrapgorillas said:


> Is there a good resource for what the best tubes are for the Crack besides wading through this thread and the one on the Bottlehead forums? I just finished building mine not too long ago (have the speedball but it's not installed yet). So far I've seen that a lot of people like the RCA clear tops (also some don't), and the Tung-Sol 5998 seems to be popular as well. Thoughts?
> 
> Edit: after looking up the price of a Tung-Sol 5998, I should probably be asking what the best bang-for-your-buck tube is instead. My preferred sound is clear and natural and realistic. Being used with HD650 and HD600.


 
  
 I'd start with a vintage Tung Sol 12au7's and any decent JAN (joint army navy) 6080.  Should be around $10 a pop on ebay.


----------



## PETEREK

Just picked up a Cambridge DacMagic, my desktop setup is coming together nicely.


----------



## hdtv00

Yea that's actually my one big ? I have only an Aune T1 is that really good enough to feed a crack....I wonder. But man I'm telling ya this is THE best thing yet I've heard. But also that isn't saying much , it's the only real amp I've heard. I HOPE to get to chi town for the meet but still not certain.


----------



## PETEREK

hdtv00 said:


> Yea that's actually my one big ? I have only an Aune T1 is that really good enough to feed a crack....I wonder. But man I'm telling ya this is THE best thing yet I've heard. But also that isn't saying much , it's the only real amp I've heard. I HOPE to get to chi town for the meet but still not certain.


 
 I had the T1 and agree that it's definitely one of the best, if not the best desktop Amp+DAC in it's price range. I used mine with the 7308 tube and it was very neutral and smooth.


----------



## hdtv00

Yea totally that makes me wonder what is a better tube DAC to pass onto a crack. Because truely I never went this far thought out. I went one step at time and the T1 and Crack linked up nicely no care to quality but they just fit. Now I'm wondering if there better. But I posted in another thread I for real at this point with my fav headphone Senn 560 Ovation II probably wouldn't trade it for the world, no joke. I believe it outdoes the 600, 650 and 700. Owned. Although I will say the 650 is very very nice with this setup. maybe =. It's just that good.  Tubes, phones there is a time and a place for each. It varies but I'll tell ya 20 yrs later I'm in a really really good place.


----------



## krikor

funyunbreath said:


> I've been doing quite a bit of tube rolling this week and personally I'd say the best bang for the buck power tube I've got is a Sylvania JAN 6080WB. It holds its own against my Tung Sol 7236 and 5998, and costs like $10. It has slightly emphasized bass, which could be a good thing for you if you're into electronic.


 
 I'm curious... do you happen to what's the difference between the 6080WC and 6080WB? Sonically or otherwise. My Crack came with the Sylvania JAN 6080WC. Thanks!


----------



## krikor

ohcrapgorillas said:


> My preferred sound is clear and natural and realistic. Being used with HD650 and HD600.


 
 I know there are endless threads about the HD650 vs. HD600, but sifting through those is daunting, and since you brought it up...
  
 What is your opinion of the two with the Crack? Noticeable differences? I've got the HD650 but have been thinking about picking up the HD600 to explore its character as well. I wonder if there is as strong a difference as there is between the Beyerdynamic DT990 and DT880.


----------



## FunyunBreath

krikor said:


> I'm curious... do you happen to what's the difference between the 6080WC and 6080WB? Sonically or otherwise. My Crack came with the Sylvania JAN 6080WC. Thanks!


 
  
 I've wondered that myself actually. Not sure what the differences between WA WB and WC are.
  
 My first crack kit from 3 years ago came with a GE 6080WA. This new one came with the Sylvania 6080WB. The GE tube may just be old and dying but it sounds muddy and flat in comparison to the Sylvania.


----------



## Maxhawk

Alternate output tubes to try that aren't as expensive as the 5998:
  
 Bendix/Chatham 6080WB graphite plate (around $50-$60 if you wait for a good deal on ebay) -- very musical, good imaging, more bass than the 5998 (as are most equivalent tubes). 
  
 Sylvania Gold Brand GB6080 ($10-$30 on ebay) -- luscious, more creamy midrange than standard 6080
  
 Mullard CV2984 ($40-$80) -- Seems more analytical with tighter bass than my stock GE 6080


----------



## JamieMcC

maxhawk said:


> Alternate output tubes to try that aren't as expensive as the 5998:
> 
> Bendix/Chatham 6080WB graphite plate (around $50-$60 if you wait for a good deal on ebay) -- very musical, good imaging, more bass than the 5998 (as are most equivalent tubes).
> 
> ...


 
  
 You might like to add these to the list the GEC 6080 $35ish Svetlana Winged C 6H13C $10ish and Chatham 6as7g $15-20ish


----------



## Zashoomin

To those inquiring about the Khozmo attenuator, it came in last week and I have been playing around with it for a little.  It sounds wonderful, measures correctly, looks beautiful, and everything seems to be working swimmingly.  Mine came in a lovely blue color and I think that with the new mkII design that there will be less problems when compared to the mkI.


----------



## FunyunBreath

This is an excellent tube combo to try out:
  
 -Amperex 12au7 ( Holland made, branded for Hewlett Packard)
 -5998
 Compared to other combos I've been testing the mids are just absolutely glorious. Very full bodied with a rumbling low end. Highs are crisp and clear without being to sharp. 
	

	
	
		
		

		
			





 
  
 This particular Amperex is usually super cheap since it's branded HP. I think I picked it up on Ebay for like $18.


----------



## lextek

Curious which tube do people find have the most affect on sound? Power or input?


----------



## nailbunny7

lextek said:


> Curious which tube do people find have the most affect on sound? Power or input?


 
 My instinct would have to say input 'should' have the most effect on sound.


----------



## NightFlight

nailbunny7 said:


> My instinct would have to say input 'should' have the most effect on sound.




I thought the same.

When I was guided on this question the clear cut answer was the output tube. That is not to say that input tube changes have no effect on tonal signature. 

If you are deciding which to start with, then my experience with the crack would be to start with the output section.


----------



## sasquatch98

Right now I'm listening to a Darkvoice 336se with my HD580s and loving it even with the stock tubes (new ones on the way though). How does the crack compare to the 336se sound quality wise? I'm interested in the crack since it would be easier to upgrade or repair in the future it seems to me although I don't have any complaints about the 336 so far.


----------



## FunyunBreath

nightflight said:


> I thought the same.
> 
> When I was guided on this question the clear cut answer was the output tube. That is not to say that input tube changes have no effect on tonal signature.
> 
> If you are deciding which to start with, then my experience with the crack would be to start with the output section.


 
  
 I would agree with you on that. I've noticed power tubes seem to have a much bigger impact on soundstage, dynamics, EQ, and bass impact. The input tubes are a much more minor difference in comparison. Even switching between completely different tube types like 12au7, 12bh7, and 6sn7.


----------



## NightFlight

funyunbreath said:


> I would agree with you on that. I've noticed power tubes seem to have a much bigger impact on soundstage, dynamics, EQ, and bass impact. The input tubes are a much more minor difference in comparison. Even switching between completely different tube types like 12au7, 12bh7, and 6sn7.


 
  
 It is less so than the output section for sure. But I've seen a lot of people discounting the effect the input tube has on the signature when I've found this to be not true at all.  I've found my favorite so far to be a tung-sol 12BH7, which requires some minor circuit changes to the input C4S boards to get the most out of it. But without those circuit changes dropping in a 12BH7 can result in a bit of a change for the worse.


----------



## FunyunBreath

What effect do these circuit changes have on on the 12bh7's sound?
  
 I've been running 12bh7's in my speedball'd crack for quite some time now and they sound great to me. Similar to a 6sn7 but without the A/C heater noise. Curious what the changes would be to make them sound even better.


----------



## NightFlight

funyunbreath said:


> What effect do these circuit changes have on on the 12bh7's sound?
> 
> I've been running 12bh7's in my speedball'd crack for quite some time now and they sound great to me. Similar to a 6sn7 but without the A/C heater noise. Curious what the changes would be to make them sound even better.


 
  
 Tightens up the bottom end and just dials in the voltage seen on Terminals 1 and 5. You'll want to see ~75-85v there.  There's a very active input tube mod thread on the BH forums where you'll find the info: http://bottlehead.com/smf/index.php?topic=5989.0
  
 Awesome thread there. There's a recommendation to upgrade the transistors on the input C4S boards to which should be done as well. Jumping to the end you'll find Maxhawk designed and had printed a whole new CS4 board to accommodate easier rolling!


----------



## FunyunBreath

Awesome thanks for the links!
  
 Is there any harm in using 12bh7's without doing these mods? I had been under the impression that with the speedball in place it was safe to use them, just want to make sure though.


----------



## NightFlight

funyunbreath said:


> Awesome thanks for the links!
> 
> Is there any harm in using 12bh7's without doing these mods? I had been under the impression that with the speedball in place it was safe to use them, just want to make sure though.


 
  
 From what I've read I gather the beefier transistor has a much better safety margin because the 12BH7 is pulling more current. That is discussed in BH thread I linked. Review that for confirmation.


----------



## i luvmusic 2

I bypass the last 220uf caps with a SOLEN 2.2uf it did  add a little treble,It sound nice for the HD650 but not for DT880 600 ohms it's bright.


----------



## Maxhawk

lextek said:


> Curious which tube do people find have the most affect on sound? Power or input?


 
  
 Theoretically the input tube should have more of an effect because that's where the gain is, but since there's only 2 tubes, both have a noticeable effect on the sound. In my experience, the input tube makes the biggest difference overall, but the output tube has a larger effect on bass because it controls the output impedance. I've been happiest overall with a 5687 at the input, but it has a different pin-out which I address using a 4PDT switch to change the wiring. This tube most certainly requires the speedball constant current source as well as swapping its stock MJE350 for an MJE5731 since it pulls a lot of current and it gets really warm under the hood.


----------



## Demoninja

Anyone have any tips for isolating my BHC? I have a bit of static coming through the amp and I've identified it to be my power line adapter causing it rather than any construction issues. I need the power line adapter because my wifi signal doesn't reach my room.


----------



## FunyunBreath

Maybe an isolation transformer would help?
  
 I keep my amps plugged into this and it does the trick as far as removing noise from the shoddy electric in my apartment:
  
http://www.amazon.com/Tripp-Lite-Isolation-Transformer-Outlet/dp/B00006HPFH
  
 Since it's Prime on Amazon you could always try it out and return it if it doesn't work for you.


----------



## NightFlight

funyunbreath said:


> Maybe an isolation transformer would help?
> 
> I keep my amps plugged into this and it does the trick as far as removing noise from the shoddy electric in my apartment:
> 
> ...


 
  
 Hilarious. I have a Tripp-Lite ISO unit as well. Snatched up for $5 from Value Village!  Recently I gutted it and pulled out the protection circuitry. I think all the internal runs are 14AWG, which is plenty, but I'm still considering getting rid of all the jumpers and soldering it instead and get rid of all those brass to copper transitions.
  
 But for electrical noise, I've found it works well that way too. 
  
 Then I found out my input tube was triggering a horrible ringing in one channel at ~16-18Khz range once fully warmed up.  It was weird to hear it coming from the headphones.... then unplug the headphones and still hear it. The amp was literally screaming! Kinda like coil whine.  Swapped the input tube and the problem went away *fingers crossed*   It had better not be my output tube. Because its my precious....


----------



## hdtv00

Man stop, don't even be letting me hear nightmare tube stories. I just today got my first Western Electric 421A and I don't want to hear any bad tube stories. It gave me a chill.
  
 Although that said it's nice to know hear a story of something that might or might not happen to a crack so we're not freaked totally out if it happened to us. Precious and *fingers crossed, indeed*.


----------



## Demoninja

funyunbreath said:


> Maybe an isolation transformer would help?
> 
> I keep my amps plugged into this and it does the trick as far as removing noise from the shoddy electric in my apartment:
> 
> ...


 
  
 The price on that seems a bit much. I'll probably see if there's anything else I can do. I think I would rather sell the BHC and get another amp than to spend another 125.


----------



## JamieMcC

demoninja said:


> Anyone have any tips for isolating my BHC? I have a bit of static coming through the amp and I've identified it to be my power line adapter causing it rather than any construction issues. I need the power line adapter because my wifi signal doesn't reach my room.


 
  
 I had a similar issue with a power line adapter when steaming from my lap top to dac with the low level static back ground fluctuations matching the flickering of the LED on the power line adapter perfectly. Strangely this only happened when streaming from one laptop and not a couple of other devices I also use and it disappeared if I connected the same laptop to my dac via usb.
  
 I have since moved my digital library to a small desk/net top pc and now have it connect via optical which has been worked well for me.
  
 A bit or trial and error I guess is the answer.


----------



## daltonljj

Just got my HD800 today after 2 years of eyeing on them. Paired it up with the crack which I built it prior to the purchase of the HD800. I must say the results are just simply spectacular. No hissing noise just pure music enjoyment to my ears. I've tried the hd800 with other tube amps that are in the range on 2000-5000 and I have to say this pairing is definitely comparable if not better than some. Doubt i will need an amp upgrade anytime soon. Mainline maybe 
	

	
	
		
		

		
			





 ???


----------



## Maxhawk

daltonljj said:


> Doubt i will need an amp upgrade anytime soon.


 
  
 Do you have the speedball upgrade?


----------



## daltonljj

maxhawk said:


> Do you have the speedball upgrade?


 
 yupp i do ... haha


----------



## mcandmar

Power line adapters, ugh.  As an IT guy the very thought of plugging a network cable into a power socket sends chills down my spine


----------



## JamieMcC

mcandmar said:


> Power line adapters, ugh.  As an IT guy the very thought of plugging a network cable into a power socket sends chills down my spine


 

 If it was only powerline adapters that cause problems, my car alarm will knock out my wireless signal. With the car on the drive press the key fob to lock the doors and bam signal drops out unlock the doors wifi works again!  Guess that's life and you cant have it all.... 
  
 Edit actually if everything was working perfectly I think I would be worried something bad was about to happen as it definitely wouldn't be normal


----------



## atomicbob

Replaced the 22K plate resistors on the 12AU7 with Bournes 50K 1W 25 turn trimpots to accommodate multiple input tube types in a non-speedballed Crack. Currently have a Tungsram E80CC as input tube. When this sucker reaches 88 volts, you're going to hear some serious ****. E80CC plate to 6AS7g grid. (with apologies to Back To The Future.)


----------



## MoatsArt

Great idea.  Many possibilities without affecting the bias of the power tube.


----------



## Maxhawk

Do you guys know the difference between a double and triple-mica Sylvania Gold Brand GB6080? Except for the mica, the internal construction is identical. The triple however has a tan colored plastic bottom while the double is black.


----------



## i luvmusic 2

As i said before my CRACK and S.E.X. was not working,2 weeks ago i managed to fixed the CRACK and today i installed a Cree Diodes.


----------



## DDDamian

i luvmusic 2 said:


> As i said before my CRACK and S.E.X. was not working,2 weeks ago i managed to fixed the CRACK and today i installed a Cree Diodes.


 
 As the proctologist said: glad to see your Crack is healthy again!


----------



## MoatsArt

Has anyone tried choke loading the cathode of the power tube (6080 etc) of the Crack? I have read about supposed benefits of choke loading a cathode follower.  While I don't have a Crack anymore, I am interested in its effects in respect to another build.


----------



## jbarnhardt

moatsart said:


> Has anyone tried choke loading the cathode of the power tube (6080 etc) of the Crack? I have read about supposed benefits of choke loading a cathode follower.  While I don't have a Crack anymore, I am interested in its effects in respect to another build.




Check out the Bottlehead forums - this topic is discussed rather extensively there in the Crack thread IIRC. 

-John


----------



## MoatsArt

Thanks for that.
  
 I know that there has been extensive experimentation with chokes to replace the resistors in the power supply, thus CLCLC or some variation thereof.  I also know that the subject of plate (anode) loading the 12AU7 with a choke has been brought up, but that the experts prefer the C4S.  I haven't seen any mention to date of loading the cathode of the cathode follower with a choke.  Can you please provide me with a link to where you have seen this?
  
 Warm regards
  
 Nathan


----------



## MoatsArt

Forget about it.  I don't know what I am talking about.  I am just an idiot asking stupid questions.
  
 Sorry


----------



## JamieMcC

moatsart said:


> Forget about it.  I don't know what I am talking about.  I am just an idiot asking stupid questions.
> 
> Sorry


 

 Hey your not alone, that's normally my line


----------



## NightFlight

i luvmusic 2 said:


> As i said before my CRACK and S.E.X. was not working,2 weeks ago i managed to fixed the CRACK and today i installed a Cree Diodes.


 
 Neat idea. Do you have a scope to show the difference between the two bridges? I assume its better.


----------



## i luvmusic 2

dddamian said:


> i luvmusic 2 said:
> 
> 
> > As i said before my CRACK and S.E.X. was not working,2 weeks ago i managed to fixed the CRACK and today i installed a Cree Diodes.
> ...


 
 Alive well........
	

	
	
		
		

		
		
	


	



  


nightflight said:


> i luvmusic 2 said:
> 
> 
> > As i said before my CRACK and S.E.X. was not working,2 weeks ago i managed to fixed the CRACK and today i installed a Cree Diodes.
> ...


 
  Sorry i don't have a scope.To my ears with this MOD the background  is quieter(this crack never have any hum before the cree diodes was installed now it's even quieter),overall sound is smoother.


----------



## NightFlight

I thought I would ask. I'm not one to push the double blind test mantra. What's are the part number(s) you used?


----------



## ph0ngt3p

could somebody share the speedball manual pdf please ? for some reason I cannot download it and now the webpage says I have reached the download limit


----------



## MoatsArt

Have you tried emailing Bottlehead? If you purchased the Speedball from them they should have supplied this on a disc.

Cheers

Nathan


----------



## ph0ngt3p

moatsart said:


> Have you tried emailing Bottlehead? If you purchased the Speedball from them they should have supplied this on a disc.
> 
> Cheers
> 
> Nathan


 
 So they'll include a CD with the manuals ? I didn't know about it. But then why'd they put the PDF manuals in the cart ?
 Will try to email Doc now, thanks


----------



## Maxhawk

ph0ngt3p said:


> So they'll include a CD with the manuals ? I didn't know about it. But then why'd they put the PDF manuals in the cart ?
> Will try to email Doc now, thanks


 
 Bottlehead no longer ships with a CD and the PDF is one-time download only. I suspect they might change the one-time policy if they get too many instances of folks not getting it the first time. I personally had to ask again since I was downloading originally on a slow, spotty connection that timed out at 30%.


----------



## PETEREK

Just got my Crack and Speedball kit in the mail. I have a week off work after tomorrow, so I will have plenty of time to get it together. I'm excited!


----------



## jorgen83

maxhawk said:


> Bottlehead no longer ships with a CD and the PDF is one-time download only. I suspect they might change the one-time policy if they get too many instances of folks not getting it the first time. I personally had to ask again since I was downloading originally on a slow, spotty connection that timed out at 30%.


 
  
 Perhaps the Bottlehead peeps will frown on this, but I quite simply found the manual with a Google query some time before I bought the kit. 
  
 That said: bought it, built it, love it! I'm still using the tubes it came with, both RCA tubes, so can't wait to see what happens when I put a 6AS7 in and a cleartop.


----------



## ph0ngt3p

jorgen83 said:


> Perhaps the Bottlehead peeps will frown on this, but I quite simply found the manual with a Google query some time before I bought the kit.
> 
> That said: bought it, built it, love it! I'm still using the tubes it came with, both RCA tubes, so can't wait to see what happens when I put a 6AS7 in and a cleartop.


 
 I've found a 6/4/10 version of the speedball manual. Is it too old ? Any major differences between this and the newer revised one ?


----------



## kekoukela

maxhawk said:


> I posted this on the Bottlehead forum, but there seems to be more activity here so I thought I'd repeat it.
> 
> This thread (http://bottlehead.com/smf/index.php?topic=5989.131) on the Bottlehead forum describes methods to mod the Crack to optimize bias for various tube types. I had added a switch and resistors to allow use of the 12BH7 as well as E80CC/5687 but wanted something neater and consequently more reliable long-term. Here's the before shot:
> 
> ...


 
 I would be VERY interested in getting one. Is it expensive?


----------



## kekoukela

funyunbreath said:


> Finally finished the kit I've had sitting around since last summer!
> 
> This is the second Crack I've built, got a good deal on it in a group buy and wanted to build another to replace the one I've had for a few years. I took my time with it and made a few modifications right from the start:
> 
> ...


 
 Home I'm not being too annoying, but may I ask you to take some more photos of your build? especially profile pics? I am really interested in the PCB boards idea! BEAUTIFUL


----------



## FunyunBreath

Yeah no problem! 
  
 Here's some macro shots of the internals. Other than the socket PCB's you'll probably notice the 9-pin socket bracket is mounted from underneath. It took a bit of grinding to get the screws to fit properly but it gives the top of the chassis a really clean look.


----------



## kekoukela

Man Just beautiful work. Are you planing on installing the Speedball on this crack? Do you think the increase in height for the 8 & 9 pin sockets will affect installation of the speedball?


----------



## FunyunBreath

Thanks! Comparing my speedballed crack with this one it looks like the height on the sockets is almost the same so there shouldn't be any issues installing the boards. 
  
 I've been doing A/B tests between the 2 amps and I'm still undecided on whether or not to put the speedball in. With the right tube combo in the stock crack you can get a lot of the same benefits as the SB but still keep that smooth sound.


----------



## atomicbob

funyunbreath said:


> Thanks! Comparing my speedballed crack with this one it looks like the height on the sockets is almost the same so there shouldn't be any issues installing the boards.
> 
> I've been doing A/B tests between the 2 amps and I'm still undecided on whether or not to put the speedball in. With the right tube combo in the stock crack you can get a lot of the same benefits as the SB but still keep that smooth sound.


 
 Which tube combo do you feel gives you the SB advantage?
 I recently changed the 12AU7 plate resistors to 50K 20 turn pots so I could experiment with other input tube families. Currently enjoying a Tungsram e80cc with a Tung-Sol 6as7g. Also replaced the 100 uF output caps with Rubycon 470 uF 160V. Major improvement in sound stage and bass performance. The improvement was also visible on oscilloscope with 20 Hz square wave source. I have before / after screen shots if anyone is interested.


----------



## FunyunBreath

My 2 favorite combos are the 5998/Amperex 12au7 and 5998/Jan Sylvania 6SN7GT (VT231)
  
 It seems like the 5998 just pulls the best out of both of these tubes. When I use them with some of my other power tubes like the RCA 6AS7G, Tung Sol 7236, Sylvania 6080 the amp just loses a lot of it's clarity and dynamics.
  
 Thats a cool idea with the caps, I'd be interested to see the differences.


----------



## atomicbob

Source signal DAC - Mousai MSD192 - 20 Hz square wave at RCA outputs with 10 K load.


 BH Crack (non-SB) output with HD800 load - stock 100uF 160V Aluminum Electrolytic output caps


BH Crack (non-SB) output with HD800 load - Rubycon 470uF 160V Aluminum Electrolytic output caps

When I measured the capacitors on an LCR bridge, the Rubycons were almost exactly the same value while the stock caps were farther apart in value. Note how the Left and Right channels are much more tightly matched with the Rubycons. Also note how the ouput is closer to the input in waveform shape. Tubes used for this testing were Tungsram e80cc and Tung-Sol 6AS7g. Grid voltage at the 6AS7g has been adjusted to 88 Volt on each channel.


----------



## Doc B.

Hey Bob, nice! Are you going to try some film caps too?


----------



## atomicbob

doc b. said:


> Hey Bob, nice! Are you going to try some film caps too?


 
 Interesting you should ask that. A pair of 100uF 250V Dayton polypropylrne caps just arrived today.


----------



## Doc B.

Would also be interesting to see that square wave with a passive 300 ohm load.


----------



## atomicbob

I'll have to get a couple of 300 ohm 1% MF. Otherwise I can do one channel at a time with a 312 ohm load with a GR1840a.


----------



## atomicbob

Here is a comparison of HD600 and 268R loads at the same input attenuator level for 20 Hz square wave. Same MSD 192 source, 470uF Rubycon capacitors:
  

 Above HD600 load - below 268R load


----------



## cspirou

@atomicbob
  
 For a capacitor coupled amp, these are pretty good square ware responses. You have any curves at 500Hz?


----------



## atomicbob

@cspirou - I have 200 Hz from that session:
  
 Mousai MSD 192 source output 200 Hz square wave 10K load:

  
 BH Crack (non-SB) output HD800 load stock 100 uF Aluminum Electrolytics:

  
 BH Crack (non-SB) output HD800 load Rubycon 470 uF Aluminum Electrolytics:

  
 BH Crack with Tungsram e80cc input and Tung-Sol 6AS7g output tubes, 6AS7g grid adjusted to 88V both halves.
  
 I will repeat these measurements when I have all the capacitors I intend to test in house. This was the preview testing.


----------



## PETEREK

First things first, paint. Black with a pearly metallic top coat that changes color at different angles.


----------



## kekoukela

Very nice paint job!!!! Keep us updated!


----------



## PETEREK

Who else assembled their crack in a room where they have no computer? I'm getting a workout!


----------



## PETEREK

Ok, not too bad for the first day. I spent probably 3 hours on this, maybe a little more. Hopefully I can get close to finishing tomorrow. And yes, I did route some wires differently, for fun. I used Black Dragon cable for the RCA inputs, for fun, so I had a little extra of each of the stock wires to take different routes. I did a 4 wire braid instead of a 2 wire twist in there. I don't like my stuff to look the same as everyone else's, it's a problem I have.


----------



## HolyCheese

ph0ngt3p said:


> So they'll include a CD with the manuals ? I didn't know about it. But then why'd they put the PDF manuals in the cart ?
> Will try to email Doc now, thanks


 
  
 If you have lost the manual it's hard to get it back. But I found this torrent online you could use.
 magnet:?xt=urn:btih:1446c8b4919fe5dc3287a7ac2e629cf0f32dc7ba&dn=bottlehead%20crack%20manual.7z
  
 I checked it and it looks like it's the same as far as I can remember.


----------



## FunyunBreath

Thats piracy man, I doubt the mods and folks at Bottlehead will be too happy about that link. You should probably edit your post and remove it asap.


----------



## Doc B.

We used to include manuals on CD. But nobody has a CD drive anymore. So the manual is offered in downloadable form when you purchase a kit from us. As for using a manual from a torrent - we do update them every now and then. It may not be a current version.


----------



## hdtv00

Well isn't it a little ridiculous to have have it for download. I bought mine used on here who I'm sure more than supports bottlehead if there is something wrong with sharing the manual that's just messed up if you ask me.


----------



## FunyunBreath

Maybe I'm wrong here but I would imagine the manual exists on torrent sites to aid people in building the amp cheaper than what it costs to buy the kit through bottlehead.


----------



## ph0ngt3p

Well I've asked Josh to increase my download limit twice and I still couldn't download the manual. The website gave me a 403 forbidden error.


----------



## kekoukela

So I tried to fix my volume intensity with this fix from the FAQ portion of Bottlehead's site:
  
 3.  I can barely turn my Crack up at all before it's far too loud, what do I do?
 Disconnect the white wire at the pot that originated at the left RCA jack.  Install a 75K resistor between this wire and where it connected on the pot.  
 Repeat this step for the red wire coming from the right RCA jack.
 Attach and solder one 33K resistor between each outer pair of lugs on each level of the volume pot.
 Resistor wattage is unimportant, 1/10 Watt or greater will work nicely.
  
  
 When I completed this, the left side as louder than my right side, resulting in a channel imbalance. In my infinitely intelligent brain, I decided to remove JUST the 75K resistors, leaving the bridged 33K resistors on the volume pot. I turned it on and tried on the headphones and now I cannot hear anything. Even after removing all the resistors. If I turn the volume all the way up, I can SLIGHTLY hear music. 
  
 Does anyone know what I broke? Or rather an educated guess? It has speedball installed.


----------



## jorgen83

funyunbreath said:


> Maybe I'm wrong here but I would imagine the manual exists on torrent sites to aid people in building the amp cheaper than what it costs to buy the kit through bottlehead.




It's pretty hard (nigh impossible) to find an equivalent transformer, and it's really not that much cheaper if at all.


----------



## cspirou

jorgen83 said:


> It's pretty hard (nigh impossible) to find an equivalent transformer, and it's really not that much cheaper if at all.




You dont have to get the exact same transformer. You can always find a transformer thats close and vary the resistors in the power supply to get the appropriate B+ voltage.


----------



## PETEREK

So, I finished the build a little bit ago and am having a channel imbalance. Both sides have sound but the left has a hum even at low volume, and is muffled when the volume is raised. I have looked everything over but can't find anything that has been connected wrong. Where should I start troubleshooting this further?


----------



## Charliemotta

Ground loop..


----------



## Doc B.

hdtv00 said:


> Well isn't it a little ridiculous to have have it for download. I bought mine used on here who I'm sure more than supports bottlehead if there is something wrong with sharing the manual that's just messed up if you ask me.


 
 I'm sorry that I am not quite able to decipher the grammar in this post. If you purchased the kit from someone other than Bottlehead, they would have the manual that came with the kit.


----------



## Keithpgdrb

hdtv00 said:


> Well isn't it a little ridiculous to have have it for download. I bought mine used on here who I'm sure more than supports bottlehead if there is something wrong with sharing the manual that's just messed up if you ask me.


 

 whoever sold you the amp is just as responsible for giving you the instructions.  You should have made sure it was part of the deal, or had the seller contact bottlehead for instructions. they at least have a record of him buying it if he is the original owner.  This isn't just an instruction manual, its a complete step by step on how to build the amp.
  
 They likely don't just put the manual up for download because it is so detailed, that you could build the amp from the instructions without buying the kit.  This is pretty unlikely because it would be a huge pain tracking down parts and the like, but if someone was so inclined, it could be done.
  
 so, while this doesn't help you, it should put bottleheads position into slight perspective.  I imagine though that with a little bit of effort, you will find the instructions.


----------



## hdtv00

Now I'm starting to see why they named it the crack....yea I was addicted. Now I'm cut off..



 I have 4 5998's , 1 Western Electric 421A, FAA(whatever that is), Sylvania 6080(I think not pictured) and countless 12au7 as you can see all crack tubes in left slot. And all 6dj8 on left side for my Aune T1 feeding the crack.


----------



## NightFlight

cspirou said:


> You dont have to get the exact same transformer. You can always find a transformer thats close and vary the resistors in the power supply to get the appropriate B+ voltage.


 
  
 Hmm, I don't think its worth it. The Crack kit is relatively speaking, very cheap.  Plus the money is well spent keeping a maw and paw shop alive.


----------



## DDDamian

nightflight said:


> Hmm, I don't think its worth it. The Crack kit is relatively speaking, very cheap.  Plus the money is well spent keeping a maw and paw shop alive.




+1

@hdtv00 - so you're the one driving up prices!


----------



## HolyCheese

cspirou said:


> You dont have to get the exact same transformer. You can always find a transformer thats close and vary the resistors in the power supply to get the appropriate B+ voltage.


 

 If you can do that, you probably don't need the manual at all. 
  
  
 I just posted the link here because it is very hard to get the manual, I asked a few times and never received it so I tried to find the manual on the internet.
  
 It's probably better to get the manual directly from bottlehead. That way you have the most up to date version. But still it's better than nothing.


----------



## cspirou

nightflight said:


> Hmm, I don't think its worth it. The Crack kit is relatively speaking, very cheap.  Plus the money is well spent keeping a maw and paw shop alive.


 

 The Crack kit is certainly a good value. For the Speedball upgrade though I think I would rather order a few CCCS kits from K&K audio.
  
 http://www.kandkaudio.com/other-kits/


----------



## ohcrapgorillas

It seems that the 5998 is everyone's preferred power tube, so I'll pick up one of those at some point. I'm curious about what people find to be the most realistic and natural sounding input tube, though? Other mods I plan on doing soon are replacing the output capacitors with Dayton polyproylene caps (2 x $24, not bad), and a stepped attenuator--any recommendations below $50? I'm trying to keep this as cheap as possible.

I may have to place the order for the tubes soon since I think I might have busted my power tube when it rolled off the table onto the floor maybe 1.5 ft while installing Speedball. The amp is really quiet and the left channel barely comes through at all. It could also be an issue with the Speedball but I've double and triple checked all the connections and everything is in the right place.


----------



## PETEREK

ohcrapgorillas said:


> It seems that the 5998 is everyone's preferred power tube, so I'll pick up one of those at some point. I'm curious about what people find to be the most realistic and natural sounding input tube, though? Other mods I plan on doing soon are replacing the output capacitors with Dayton polyproylene caps (2 x $24, not bad), and a stepped attenuator--any recommendations below $50? I'm trying to keep this as cheap as possible.
> 
> I may have to place the order for the tubes soon since I think I might have busted my power tube when it rolled off the table onto the floor maybe 1.5 ft while installing Speedball. The amp is really quiet and *the left channel barely comes through at all*. It could also be an issue with the Speedball but I've double and triple checked all the connections and everything is in the right place.


 
 I'm having a similar issue with my Crack, I have not installed my Speedball yet though. I'm actually sending mine over to Krikor so he can take a look at mine for me, I have checked over my connections many times already and cannot figure out what's wrong.


----------



## FunyunBreath

ohcrapgorillas said:


> It seems that the 5998 is everyone's preferred power tube, so I'll pick up one of those at some point. I'm curious about what people find to be the most realistic and natural sounding input tube, though? Other mods I plan on doing soon are replacing the output capacitors with Dayton polyproylene caps (2 x $24, not bad), and a stepped attenuator--any recommendations below $50? I'm trying to keep this as cheap as possible.
> 
> I may have to place the order for the tubes soon since I think I might have busted my power tube when it rolled off the table onto the floor maybe 1.5 ft while installing Speedball. The amp is really quiet and the left channel barely comes through at all. It could also be an issue with the Speedball but I've double and triple checked all the connections and everything is in the right place.


 
  
 Whoa I didn't realize Dayton sold film caps for that cheap. Did you go for the 250V 90UF ones or 100UF?
  
 I used a Valab 23 step attenuator in my first build: http://www.ebay.com/itm/Valab-23-Step-Ladder-Type-Attenuator-Potentiometer-100K-Log-Stereo-/251921318184?pt=LH_DefaultDomain_0&hash=item3aa7ae4128


----------



## nailbunny7

funyunbreath said:


> Whoa I didn't realize Dayton sold film caps for that cheap. Did you go for the 250V 90UF ones or 100UF?
> 
> I used a Valab 23 step attenuator in my first build: http://www.ebay.com/itm/Valab-23-Step-Ladder-Type-Attenuator-Potentiometer-100K-Log-Stereo-/251921318184?pt=LH_DefaultDomain_0&hash=item3aa7ae4128


 
 Still, this is a better cap, and is on sale for 25 dollars (the 100uf, 250V one):
 http://www.partsconnexion.com/capacitor_film_claritycap_px.html


----------



## PETEREK

My left channel sounds like a fart. I cannot figure out what is wrong with it, but it is giving the effect of a badly blown driver (the headphones are fine). Is anyone up for checking it out and hopefully fixing it for me? I can send along some nucleotide RCA interconnects for whomever does it, and return shipping money. Only people in the US and who have positive feedback OR a lot of posts please. 
  
 I've been losing my mind trying to isolate the problem, but have not made any progress. Desolder, resolder, repeat..
  
 PM me if interested, thanks.


----------



## ZachPtheDude

peterek said:


> My left channel sounds like a fart. I cannot figure out what is wrong with it, but it is giving the effect of a badly blown driver (the headphones are fine). Is anyone up for checking it out and hopefully fixing it for me? I can send along some nucleotide RCA interconnects for whomever does it, and return shipping money. Only people in the US and who have positive feedback OR a lot of posts please.
> 
> I've been losing my mind trying to isolate the problem, but have not made any progress. Desolder, resolder, repeat..
> 
> PM me if interested, thanks.




Did you post about your issue on the Bottlehead forum?


----------



## Mich4lle

ohcrapgorillas said:


> It seems that the 5998 is everyone's preferred power tube, so I'll pick up one of those at some point. I'm curious about what people find to be the most realistic and natural sounding input tube, though? Other mods I plan on doing soon are replacing the output capacitors with Dayton polyproylene caps (2 x $24, not bad), and a stepped attenuator--any recommendations below $50? I'm trying to keep this as cheap as possible.
> 
> I may have to place the order for the tubes soon since I think I might have busted my power tube when it rolled off the table onto the floor maybe 1.5 ft while installing Speedball. The amp is really quiet and the left channel barely comes through at all. It could also be an issue with the Speedball but I've double and triple checked all the connections and everything is in the right place.


 
 Well you were asking about an input tube, I have done a lot of research and I am also pretty interested if anyone else here agrees with me, but I read that the Amperex Bugleboys are very realistic sounding tubes and are a great match with the 5998. So that might be a good place to start, but they are pretty pricey at around 75 dollars a tube. So if anyone has hands on experience with this tube please do chime in.


----------



## FunyunBreath

mich4lle said:


> Well you were asking about an input tube, I have done a lot of research and I am also pretty interested if anyone else here agrees with me, but I read that the Amperex Bugleboys are very realistic sounding tubes and are a great match with the 5998. So that might be a good place to start, but they are pretty pricey at around 75 dollars a tube. So if anyone has hands on experience with this tube please do chime in.


 
  
 +1
  
 Thats the exact tube combo i've been using and it sounds fantastic. The bugle boys are indeed expensive but look for "Hewlett Packard by Amperex" labeled 12au7's. They can be had for around $20 and a lot of them are just rebranded Bugle Boys.


----------



## Maxhawk

For folks who don't frequent the Bottlehead forum, I posted a bunch of measurements I took with an Audio Precision...


----------



## PETEREK

zachpthedude said:


> Did you post about your issue on the Bottlehead forum?



No I haven't.


----------



## Maxhawk

nailbunny7 said:


> Still, this is a better cap, and is on sale for 25 dollars (the 100uf, 250V one):
> http://www.partsconnexion.com/capacitor_film_claritycap_px.html


 
 Nice cap, but they're quite large at 60x81mm. The ones I used were only 42x51mm (http://www.ebay.com/itm/2pcs-250V-100uF-MKP-Crossover-Metallized-Polypropylene-Non-Polarized-Capacitor-/331366732405?pt=LH_DefaultDomain_0&hash=item4d26ff1275). Sure it's a cheap poly from China, but I figured even the cheapest ones are probably better than an electrolytic.


----------



## nailbunny7

maxhawk said:


> Nice cap, but they're quite large at 60x81mm. The ones I used were only 42x51mm (http://www.ebay.com/itm/2pcs-250V-100uF-MKP-Crossover-Metallized-Polypropylene-Non-Polarized-Capacitor-/331366732405?pt=LH_DefaultDomain_0&hash=item4d26ff1275). Sure it's a cheap poly from China, but I figured even the cheapest ones are probably better than an electrolytic.


 

 That's true, any film will be better than a standard electrolytic. I've seen people make the Obbligato 100uf caps fit, and those are 65x135mm, so the Clarity cap would be easy by comparison 
 What I personally did was leave the electrolytic in there and bypassed it with a 47uf Obbligato Gold capacitor for a combined total of 147uf.


----------



## skeptic

maxhawk said:


> For folks who don't frequent the Bottlehead forum, I posted a bunch of measurements I took with an Audio Precision...


 
  
 Well done and thanks for sharing!  I've always wanted to see these sorts of measurements for the crack.  The 5998 at 600 ohms looks really good.  Now I want a T1 for my office rig 
	

	
	
		
		

		
			





 
  
 [Also - quick question, do you have the resister mod in place for running 12bh7's or were those measurements with a standard speedball'd crack?]


----------



## Maxhawk

skeptic said:


> [Also - quick question, do you have the resister mod in place for running 12bh7's or were those measurements with a standard speedball'd crack?]


 
  
 I've got a switch to optimize bias for 12AU7, 12BH7, and E80CC.
  
 http://www.head-fi.org/t/476650/crack-bottlehead-otl/6705#post_11450274


----------



## skeptic

maxhawk said:


> I've got a switch to optimize bias for 12AU7, 12BH7, and E80CC.
> 
> http://www.head-fi.org/t/476650/crack-bottlehead-otl/6705#post_11450274


 
  
 Ah, of course!  Forgot you were the one who designed the cool speedball mod/switch board.  Don't suppose you still have an extra floating around that you might be convinced to part with?


----------



## ohcrapgorillas

I found the issue with my Speedball--I had switched a couple of the tiny resistors around between the small and Speedball boards. Listening to live Radiohead with the HD600 right now and I'll leave my review short: whoa. nice.


----------



## atomicbob

ohcrapgorillas said:


> I found the issue with my Speedball--I had switched a couple of the tiny resistors around between the small and Speedball boards. Listening to live Radiohead with the HD600 right now and I'll leave my review short: whoa. nice.


 
 Nice. You have increased your trouble shooting skills. HD600 and any variant of Crack is a nice combination. I have tailored my mods to suit my tastes at this time, though I have prepared for other mods as I feel venturesome.


----------



## ohcrapgorillas

atomicbob said:


> Nice. You have increased your trouble shooting skills. HD600 and any variant of Crack is a nice combination. I have tailored my mods to suit my tastes at this time, though I have prepared for other mods as I feel venturesome.


 
 Thanks! My mods are going to be as follows (in order):
  
 * Amperex HP-branded input tube
 * Dayton polypropylene caps
 * 5998 power tube... unless there's a more realistic sounding alternative for cheaper.... but the tube itself is also so pretty...
 * stepped attenuator


----------



## atomicbob

ohcrapgorillas said:


> Thanks! My mods are going to be as follows (in order):
> 
> * Amperex HP-branded input tube
> * Dayton polypropylene caps
> ...


 
 That is a sensible order. I am quite satisfied with the stock pot at the moment. Mine seems exceptionally quiet, balanced and smooth turning. I have the Dayton caps but just put in 820 uF Nichicon Electrolytics bypassed with 1 uF polypropolene caps. Bass really kicks while snare snaps nicely.

 I should point out that increasing the value of the output caps will also increase the size of the power on transient that will appear at the headphone jack. Either change the 2.49 K resistor to around 300 ohms or keep headphones disconnected during power on and wait for the amp to warm up before plugging in the headphones.


----------



## MoatsArt

Sorry - dumb post deleted


----------



## ZachPtheDude

In the last two days I have bypassed the 100uf mkp solens I'm using for coupling caps with 1 uf, k73-11 PETP kommiekaps which I then bypassed with 0.1uf vishay-roederstein mkp 1837 bypass caps. I noticed a slightly wider soundstage with improved dynamics and bass extension. Earlier today I replaced the last electrolytic in the power supply with a 100uf obbligato PSU film cap; having already installed a choke. Haven't given it a proper listen to identify any changes. Next week I plan on bypassing the remaining electrolytics with china film caps.

Then my dad's friend offered to make me a new case for my crack, one that is both wider and deeper, designed to accomodate a speedball board, second choke, more film caps in the psu, schotkky diodes, and a switch board to change bias' so I can run 12au7 or 12bh7, pilot light all while still being a perfect fit for the plate so it can continue to be gravity mounted.

I can't wait for summer, I will post many project updates with pics.


----------



## Mich4lle

Ok so I really want somebody to please explain to me or point me to a post that can explain the importance of the uf rating on caps. Do you have to replace the output caps with two 100uf caps or what will the effect be if you use one with a much lower uf? and what is the point of bypassing caps? How does that work? Sorry for all the questions I just really want to understand this and will appreciate a response a lot.


----------



## atomicbob

uF is the value of the capacitor. Larger number mean more capacitance. Not always better. Circuits are designed using a particular value for a reason. Often the size chosen is a compromise between several diverse constraints. Here is some reading to further your knowledge:
  
 http://en.wikipedia.org/wiki/Capacitor


----------



## Maxhawk

mich4lle said:


> Ok so I really want somebody to please explain to me or point me to a post that can explain the importance of the uf rating on caps. Do you have to replace the output caps with two 100uf caps or what will the effect be if you use one with a much lower uf? and what is the point of bypassing caps? How does that work? Sorry for all the questions I just really want to understand this and will appreciate a response a lot.


 
  
 Since you mention the output caps specifically, the 100uF output cap forms a 1st order high pass filter where the impedance of your headphone is the load. The formula to calculate the resonant frequency of this filter is fc = 1 / (2*pi*R*C), where R is the load resistance, or the impedance of your headphones, and C=100uF.
  
 In the case of the popular HD600/650, they are rated at 300 ohms, so fc = 1/(2*3.14159*300*100e-6) = 5.3 Hz.
  
 This means at 5.3 Hz, the frequency response is down by 3dB, which is known as the cutoff frequency. It doesn't mean there's no signal below 5.3 Hz as there is a gentle roll-off below 5.3 Hz. 
  
 Note: In actuality, the impedance of your headphone varies with frequency so this formula is only an approximation. 
  
 So if you cut the output capacitance in half, your f3 doubles to 10.6 Hz. Although this might not sound bad at first glance, you have to realize that the frequency response starts to roll off much higher than the f3 frequency, so to maximize the (low) bass response you want to make the output cap large. Note also that if the impedance of your headphones is much lower, that also raises the f3 frequency.
  
 Explaining a bypass cap is more complicated. Large electrolytic caps have rising series resistance as frequency rises, and this resistance could be significant enough at higher frequencies to be audible (attenuation of highs). A common way to combat this is to place a small film cap in parallel that has much lower series resistance at high frequencies. It's been debated whether this actually helps, but there's plenty of anecdotal evidence that it does.


----------



## JamieMcC

This is a chart I copied from the bhf which gives the relationship between capacitor uf value headphone  impedance and cut off frequency


----------



## FunyunBreath

Speaking of caps I've been looking into getting some polypropylene ones for my build. After doing some measurements it looks like Solen 250v 100uf will fit nicely in the stock base mounted to the chassis.
  
 Whats the best way to mount them? I was thinking of using some sort of bracket with double sided tape and zip ties and was curious if anyone had any good recommendations.


----------



## JamieMcC

funyunbreath said:


> Speaking of caps I've been looking into getting some polypropylene ones for my build. After doing some measurements it looks like Solen 250v 100uf will fit nicely in the stock base mounted to the chassis.
> 
> Whats the best way to mount them? I was thinking of using some sort of bracket with double sided tape and zip ties and was curious if anyone had any good recommendations.


 
  
 Quiet a few me included have used "self adhesive cable tie mounts" plenty to choose from on ebay etc


----------



## FunyunBreath

Thanks for the reply! Couldn't quite figure out what they were called but thats exactly what I'm looking for


----------



## NightFlight

funyunbreath said:


> Thanks for the reply! Couldn't quite figure out what they were called but thats exactly what I'm looking for


 
  
 Home Depot has them.


----------



## DDDamian

nightflight said:


> Home Depot has them.




And a touch of crazy glue on the back helps prevent the inevitable falling off...


----------



## skeptic

Most zip tie mounts have a screw hole in the middle. After you pick your spot and stick them down, just drill straight through the aluminum with a small bit. Pop in a screw and nut = no falling off.


----------



## DDDamian

^ ^ even better. You don't want something falling loose. Things do warm up in there.


----------



## PETEREK

MY CRACK IS ALIVE. The left RCA was shorting to the chassis, even with the plastic gaskets. I tightened them while it was rubbing I guess. I'm glad I finally have an amp again! YAY!


----------



## atomicbob

peterek said:


> MY CRACK IS ALIVE. The left RCA was shorting to the chassis, even with the plastic gaskets. I tightened them while it was rubbing I guess. I'm glad I finally have an amp again! YAY!


 
 Excellent! Now enjoy some of the finest sound OTL design has to offer.


----------



## ZachPtheDude

cspirou said:


> The Crack kit is certainly a good value. For the Speedball upgrade though I think I would rather order a few CCCS kits from K&K audio.
> 
> http://www.kandkaudio.com/other-kits/




Which specific kit did you order? Does anyone else have experience with these kits?

Big cost differencs, hence my interest.


----------



## cspirou

zachpthedude said:


> Which specific kit did you order? Does anyone else have experience with these kits?
> 
> Big cost differencs, hence my interest.


 
  
 I haven't ordered these since I don't have the crack. I just know that the Speedball is a set of CCS boards for the resistive loads on the tubes. Knowing what I know about amps like this I would probably get two of the large cascode current source kits and two of the regular cascode current source kits without heatsinks. You might be fine buying the 4 cascode current source kits and two of the 5 watt heat sinks but the extra two watts of heat dissipation is nice to have.
  
 Note that the Speedball kit is specifically made for the Crack and it's form factor so you might to do a little bit of work to get the boards to fit nicely in there and you'll have to adjust a variable resistor to get the right current. Otherwise I see no reason why these boards wouldn't work for the crack.


----------



## DDDamian

I just put two C4S boards in my S.E.X amp - nice addition at a great price from Bottlehead. Why not use their offerings? Sure you may save a couple bucks but I'd rather support the OEM in this case.


----------



## JamieMcC

One of the best things about buying Bottlehead gear is the fantastic support and trouble shooting they offer via the bhf for the times when things just are not going as planned. Asking them to troubleshoot a C4S board installation that is not their Speedball doesn't sit to comfortably.
  
 If your a experienced and savvy builder who likes a project and can trouble shoot your own instillation with out a manual then that's great.
  
 If not Bottleheads Speedball C4S comes with all the parts with a easy to follow build manual and the reassuring knowledge that if you get stuck or something goes pop then excellent builder support can be found on the Bottlehead forum.


----------



## Mich4lle

Thank you everybody for the replies,
 They all helped a great deal in understanding how the capacitor values work.


----------



## Mich4lle

jamiemcc said:


> This is a chart I copied from the bhf which gives the relationship between capacitor uf value headphone  impedance and cut off frequency


 
  
 I actually have a question about this, does this mean that with HD 650's you can use Caps of around 50uf, because the headphones are only rated to go down to 10hz anyway. So if the Amp can't produce a signal lower than that it doesn't really matter?


----------



## mithrandir38

mich4lle said:


> I actually have a question about this, does this mean that with HD 650's you can use Caps of around 50uf, because the headphones are only rated to go down to 10hz anyway. So if the Amp can't produce a signal lower than that it doesn't really matter?


 Only 10 Hz? Lol, those are some pretty brown notes!


----------



## Maxhawk

mich4lle said:


> I actually have a question about this, does this mean that with HD 650's you can use Caps of around 50uf, because the headphones are only rated to go down to 10hz anyway. So if the Amp can't produce a signal lower than that it doesn't really matter?


 
  
 Realize that although 47uF @ 300 ohms gives you an f3 of 11 Hz, the roll-off starts at a significantly higher frequency.
  
 2dB down at 15 Hz
 1dB down at 22 Hz
 0.5dB down at 32 Hz


----------



## NightFlight

The whole point (I believe) is to block DC and stop the potential destruction of your headphones.


----------



## Maxhawk

nightflight said:


> The whole point (I believe) is to block DC and stop the potential destruction of your headphones.


 
 Yes that is the purpose, but the cap's value directly influences the low end roll off, along with the impedance of your headphones.


----------



## JamieMcC

I tried some 50uf caps that I had and they worked well enough but I was using 600ohm T1's. In the past I have also used 89uf  and 90uf with good results when paired with the T1's and preferred the sonics using the higher values.


----------



## ZachPtheDude

dddamian said:


> I just put two C4S boards in my S.E.X amp - nice addition at a great price from Bottlehead. Why not use their offerings? Sure you may save a couple bucks but I'd rather support the OEM in this case.




I'm interested in c4sing only the 12au7 input tube, listening for a while, and then c4s the 6080. Then I would like to eventually compare them to the bottlehead crew's speedball. The total cost of using the K and K kits is $70 shipped. In a world of diminishing returns I am interested in potential differences between the two kits.


----------



## DDDamian

zachpthedude said:


> I'm interested in c4sing only the 12au7 input tube, listening for a while, and then c4s the 6080. Then I would like to eventually compare them to the bottlehead crew's speedball. The total cost of using the K and K kits is $70 shipped. In a world of diminishing returns I am interested in potential differences between the two kits.


 
 Yeah, in that case I can see why you're searching around. That's the beauty of these kits and their point-to-point wiring scheme - so easy to mod or "hack" in current parlance lol.
  
 Do let us know your findings!


----------



## ZachPtheDude

dddamian said:


> Yeah, in that case I can see why you're searching around. That's the beauty of these kits and their point-to-point wiring scheme - so easy to mod or "hack" in current parlance lol.
> 
> Do let us know your findings!




I will do! I think end game will be c4s to the 12au7 only, but my ears will ultimately decide. First I need to install a second choke and a 2nd large film in psu.


----------



## Doc B.

Active loads have a very positive effect on cathode followers.


----------



## ZachPtheDude

doc b. said:


> Active loads have a very positive effect on cathode followers.




Would you say one has a larger effect? From what I've read the input tube should have a much higher effect overall, specifically in regards to clarity whereas the power tube in this configurafion moreso effects the bass?

Still got lots to learn. waiting on textbooks to arrive


----------



## Doc B.

You need to consider the distortion spectra of the circuit. A CF has great value as a tool for lowering output impedance, but it comes with a sonic signature. An active load will help to reduce the presence of that signature. You are right to suggest that the input tube has a lot of impact on the sonic signature as well. However I find the CF sound to dominate over the sonic contributions of the input tube in this circuit.


----------



## ZachPtheDude

doc b. said:


> You need to consider the distortion spectra of the circuit. A CF has great value as a tool for lowering output impedance, but it comes with a sonic signature. An active load will help to reduce the presence of that signature. You are right to suggest that the input tube has a lot of impact on the sonic signature as well. However I find the CF sound to dominate over the sonic contributions of the input tube in this circuit.




Thanks Doc! Like I said, ultimately all variations will be tried and my ears will decide how the crack stays set up but these posts are extremely helpful.


----------



## krikor

peterek said:


> MY CRACK IS ALIVE. The left RCA was shorting to the chassis, even with the plastic gaskets. I tightened them while it was rubbing I guess. I'm glad I finally have an amp again! YAY!




Fantastic... glad to hear you got it working! Sorry I couldn't help you out with the troubleshooting. Sounds like we may have two Cracks running at our next meet up.


----------



## PETEREK

krikor said:


> Fantastic... glad to hear you got it working! Sorry I couldn't help you out with the troubleshooting. Sounds like we may have two Cracks running at our next meet up.



No problem man, your tips led me to finding the problem. 

We definitely will, mine will likely be stock with the speedball.


----------



## ohcrapgorillas

I've got a 5998 and a Gold Lion into the HD600 rockin out to Nick Cave's _Abattoir Blues_ and I'm having a hard time coming up with words but suffice to say I'm having a great time. "THERE IS A WAAAR COMIIING!!! THERE IS A WAAAR COMIIING!!!"_ _





  
 The tubes are probably burning in a little bit (I let the Gold Lion run overnight), but from what I've heard so far:
  
 The 5998 is very linear with better stereo separation than the stock tube (just says 6080 USA). The stock tube is warmer and stronger in the lower registers, which is actually preferable for heavier music, but just slightly soft at the tail ends of frequencies where the 5998 is flatter.
  
 I haven't listened to my stock input tube since I got a RCA clear top and a Genalex Gold Lion. First things first, I'm _really_ impressed with the Lion. It has very good separation, clean hard-hitting lows, and a midrange that is just slightly rich from realistic, reminds me of the voice of the mids on the original LCD2. The RCA clear top definitely has really pretty highs, a touch forward but with the 5998 I felt that the low end was lacking, in a way reminded me of the Etymotic HF5.
  
  
 PS It's crazy how freaking hot these tubes get.


----------



## ZachPtheDude

Currently enjoying a Tung Sol graphite plate 6080wb with a Tungsram ECC82. Going to roll in an RCA clear top eventually to compare. Anyone have any recommended input tube pairings with the graphite plate 6080wb?


----------



## PETEREK

Got my speedball installed and am really enjoying it so far. 
  
  


ohcrapgorillas said:


> I've got a 5998 and a Gold Lion into the HD600 rockin out to Nick Cave's _Abattoir Blues_ and I'm having a hard time coming up with words but suffice to say I'm having a great time. "THERE IS A WAAAR COMIIING!!! THERE IS A WAAAR COMIIING!!!"_ _
> 
> 
> 
> ...


 
 Dude, yes. I really think a small fan should be implemented in the design. The whole chassis gets hot as hell.


----------



## Maxhawk

zachpthedude said:


> Currently enjoying a Tung Sol graphite plate 6080wb with a Tungsram ECC82. Going to roll in an RCA clear top eventually to compare. Anyone have any recommended input tube pairings with the graphite plate 6080wb?


 
  
 I like the Sylvania 12BH7 (ideally needs bias adjusted but will run cooler than 12AU7 with stock values), CBS-Hytron 5814 with angled getter, and Sylvania Goldbrand GB5687 (different pin out).


----------



## ZachPtheDude

There was a NOS cbs-hytron 5814a with angled getter that I was attempting to snipe and someone beat me to it; it was a great price like $13 shipped.


----------



## Doc B.

If I may I would like to suggest that there are some easy alternatives to constantly swapping tubes and capacitors that can improve the sound of your Crack amp.
  
 First, remove and replace all of your connections - power cord, interconnects, headphone cable. Even better give them a going over with contact cleaner. I do this a couple times a year to my entire system with 14 amps and about 2 dozen interconnects and 12 pairs of speaker binding posts. It always amazes me how much the sound cleans up with freshly groomed contacts.
  
 This may be a moot point since everyone here rolls tubes so much, but if you don't roll try removing and replacing the tubes in order to clean the pins.
  
 Check your RCA jacks to be sure they are snugly mounted.
  
 Look over the solder job you did. If any connections look dry or overly blobby, take a minute to reflow them.
  
 Make sure the amp is not sitting on top of a computer or any gear with a power transformer. You are just putting unnecessary noise into the circuit when you do that.


----------



## ZachPtheDude

doc b. said:


> If I may I would like to suggest that there are some easy alternatives to constantly swapping tubes and capacitors that can improve the sound of your Crack amp.
> 
> First, remove and replace all of your connections - power cord, interconnects, headphone cable. Even better give them a going over with contact cleaner. I do this a couple times a year to my entire system with 14 amps and about 2 dozen interconnects and 12 pairs of speaker binding posts. It always amazes me how much the sound cleans up with freshly groomed contacts.
> 
> ...




Thanks for all the tips Doc. For the record I don't to roll tubes too much, I know what sound I like and I don't really want to spend more on tubes to roll in than I did on the amplifier itself. 

As far as everything else, I am slightly ocd and a perfectionist so I probably clean my contacts more often than needed and I'm always making sure the amp is kept away from my computer and DAC. 

But this is a good guide to share for those who are new and looking to improve sound quality.


----------



## ohcrapgorillas

I now can't decide which I like better...
  
 5998 with RCA clear top to HD650
 5999 with Genalex Gold Lion to HD600
  
 Both are so amazing in their own ways but right now I'm leaning towards the RCA clear top as my favorite input tube because of its gorgeous vocals. Very realistic. With the HD650 to pick up the slack on the bass, the combo is so freaking amazing I couldn't believe what I was hearing last night. (I'd also had a bit to drink at the bar...)


----------



## Jeb Listens

Hello Crack-Builders/enthusiasts, 
  
 I finally unboxed my Crack this morning and gave everything a look over.  I'm eager to begin the build so I loosely assembled  the wooden base and top plate to start thinking about what kind of finish I would like.  In the end I decided I just love the look of the unit in its unfinished "raw" state so would very much like to keep it as it is.
  
 Would anyone be able to recommend the best way to protect the both the wood base and aluminium top-plate that would result in the least amount of change to the pale, matt and unfinished appearance?  I have some experience with wood finishes but could still use some advice there as to whether to use a wax or a matt varnish.  I have no experience with metal finishes at all !  If I'm going to be applying any kind of lacquer to the top I'm guessing its by far easiest to do this before beginning the build?
  
 Much appreciated, 
  
 Jeb.


----------



## DDDamian

jeb listens said:


> Hello Crack-Builders/enthusiasts,
> 
> I finally unboxed my Crack this morning and gave everything a look over.  I'm eager to begin the build so I loosely assembled  the wooden base and top plate to start thinking about what kind of finish I would like.  In the end I decided I just love the look of the unit in its unfinished "raw" state so would very much like to keep it as it is.
> 
> ...


 
 Definitely do the top and let it really cure before starting work. A spray-bomb of matte clear coat or semi-gloss is fine for the top. If you want to keep the wood as "raw" as possible then you can apply a couple of layers of paste wax. To keep the sheen knocked down you can apply the final coat of wax embedded in some 0000 steel wool (use the steel wool to actually apply it, then wipe off excess after a few minutes). Another alternative, below the wax coat, is boiled linseed oil or tung oil wiped on with a rag. Be extremely careful of rag disposal if using BLO - can self-ignite if thrown away wet. This will enhance the figure and darken it just slightly. Wait 24-36hrs then hit it with wax as described.
  
 Or go all-out gloss lol:


----------



## D4NGER BIRD

jeb listens said:


> Hello Crack-Builders/enthusiasts,
> 
> I finally unboxed my Crack this morning and gave everything a look over.  I'm eager to begin the build so I loosely assembled  the wooden base and top plate to start thinking about what kind of finish I would like.  In the end I decided I just love the look of the unit in its unfinished "raw" state so would very much like to keep it as it is.
> 
> ...


 

 I would just get some minwax wipe-on semi gloss poly. It'll give you protection and will not change the color too much. You might also look into a shellac, it'll warm up the look of the wood a bit, give it a slight worn/vintage look. I put a mahogany stain on mine and it turned out really well, but the key for an even finish was to treat it with a wood conditioner before applying the stain. Be sure to sand the corners thoroughly before applying any stain or protection to get rid of any glue that might have been squeezed out. Any glue left on will be highlighted by the poly/shellac/stain.
  
 As far as the metal plate goes, I was in the same boat. I liked the look of it stock, it just seemed too delicate to leave it that way. I ended up using hammertone spray paint, it turned out even better than I thought. The big downside was I had to let it dry for over a week before doing the build. With regular paint you wouldn't need to wait as long, maybe a day. You definitely want to paint the metal plate before you do the build. That goes for the transformer bell as well, unless you want to paint the screws too. I didn't paint the bell, I polished it, I liked the contrast to the gray hammered paint. 
  
 Another tip, the transformer usually has crud around it, it's easy to pick off and clean. After I cleaned it up a bit, I painted it flat black with some grill paint that I had siting around and it gave the transformer a nice even color. There is a ton of options, just do a google image search for the Crack to see some really good examples. Good luck.


----------



## Jeb Listens

@DDDamian -  beautiful looking build, I must say - your amp looks fantastic and a lot bigger than mine will be - was that just an aesthetic choice or is there some extra magic going on inside?
  
 I'll look into the matt clear coat.  I'm not sure if its that i'm looking for the wrong thing or it's called something different here in the UK.  I did find a couple of clear sprays which seems like an all-purpose spray lacquer that could be used one is a Plasti-kote clear matt and the other a Rustoleum clear matt all surface spray which says it is suitable for painted surfaces so i'm not sure how it would react with bare metal. 
  
http://www.amazon.co.uk/Plasti-kote-24002-400ml-Premium-Acrylic/dp/B006O6D8FS/ref=sr_1_cc_1?s=aps&ie=UTF8&qid=1431192099&sr=1-1-catcorr&keywords=plasti+kote+clear+matt#Ask
  
http://www.amazon.co.uk/Rustoleum-AE0040003E8-400ml-Crystal-Clear/dp/B001W03PS6/ref=sr_1_2?s=diy&ie=UTF8&qid=1431192190&sr=1-2&keywords=rustoleum+clear
  
  
@D4NGER BIRD
  
 awesome tips - i'll do some experimentation with different wood finishes.  The wood seems to have quite a nice grain to it and I like the idea of a wipe on wax and build up a few layers of protection without changing things too much.  I know exactly what you mean about the stain and wood-conditioner:  I've had some horror shows in the past going straight in with the stain! 
  
 I'll also look into some protection for the transformer too.  
  
 The Crack has a really nice clean industrial look when its unfinished so hopefully I can preserve that as much as possible.  
  
  
  
 Thanks again guys, 
  
 Jeb.


----------



## DDDamian

@Jeb Listens- yep went with 6.25" deep over the stock 4". When more upgraditus hits I'm in the clear. Big-ass caps are inbound 
  
 Rustoleum is a brand over here too, aka Tremclad. It's fine but let it cure as others have said. Get's tough as nails but takes a good week. Clean the bell housing with spirits and acetone (nail polish remover works) one after the other - ensures you get the goo off.
  
 Doc B loves when the Crack stays raw - post your pics when done. Take your time and enjoy the build!


----------



## Doc B.

You don't really need anything on the brushed aluminum. I find that clear coat tends to dull the brushed effect. For keeping the base as natural looking as possible I will suggest a satin WATER base clear coat The water base finish won't darken the wood like the oil finishes will. I used it for years, though we use Birchwood Casey Tru-Oil (basically a linseed oil finish) on our own gear these days for simplicity and the slightly enhanced grain. 
  
 The thing that really needs finishing is the transformer bell. They are raw steel and will rust like crazy in a humid environment. I suggest a thorough degreasing, a bit of buffing with steel wool and a shot of satin clear. You can use the same water base stuff you put on the wood base, though an oil base clear spray might work a bit better than water base on metal that has been treated with oil to protect it.


----------



## i luvmusic 2

I personally  like the Brushed finished or Carbon Fiber (Real carbon Fiber like Jamie's).


----------



## Jeb Listens

Thanks guys, great tips and I'll definitely take care on the transformer bell - and thanks Doc - perhaps I'll just leave the top plate raw after all! 

Jeb


----------



## Allanmarcus

I just finished mine. I still need to work on the wood frame a bit, but I had to set it up and listen. I'm enjoying it right now!


----------



## JamieMcC

allanmarcus said:


> I just finished mine. I still need to work on the wood frame a bit, but I had to set it up and listen. I'm enjoying it right now!


 
 Congratulations the dark base and red top plate contrasts nicely. Don't forget to stick on your Cracks feet  it gets quiet toasty inside the enclosure fitting them allows the air to circulate inside helping to keep the heat build up in check.


----------



## Allanmarcus

jamiemcc said:


> Congratulations the dark base and red top plate contrasts nicely. Don't forget to stick on your Cracks feet  it gets quiet toasty inside the enclosure fitting them allows the air to circulate inside helping to keep the heat build up in check.


 

 Thanks for the advice. I was going to work on the wood some more and I didn't want the fee to get in the way. I'll put something under there to raise it up until I et the feet on.


----------



## Charliemotta

@Allanmarcus What king of headband cover are you using on your cans??


----------



## DDDamian

Like the headphone stand too - where'd you pick that up?


----------



## i luvmusic 2

IKEA???


----------



## Allanmarcus

That, I made. Here's how:
  
 Instructions to make a dual headphone stand from mostly Ikea parts
 Ikea Parts list:
     EKBY BJÄRNUM: bracket
         qty:2, $10 / 2 pack
     GRUNDTAL: Hanger, stainless steel
         qty:4, $3.99 / 2 pack
             note: alternative:
                 ATTEST Knob 2 pack ($4.99)
     Capita (4.5"): legs
         qty:2, $12 / 4 pack
             note, silver or white, your choice
             note, you can get the 6.25", but they will be pretty long 
         
 Hardware Store parts
     qty:8 8x32 1/2" metal screws with nuts
     qty:16,  1/2" wood screws for base
         - note, these are dependent on base you choose
     qty:4, M10x1.5" bolt
     
 Michael's
     qty:2, unfinished wood plaque for base ($3?)
         note: stain/paint/sandpaper/acrylic will be needed to finish this wood
         note: alternative: small Ikea cutting board
             APTITLIG: $4.99

 Step 1: Finish the base
     - sandpaper, stain, coat the base as desired
     
 Step 2: Prepare the brackets
     - feed the 8x32 3/4" screw into the hanger's base
     - attach the hanger to the bracket
     - screw the rest of the hanger onto the bracket
     
 step 3: Attach the legs to the bracket
     - you will need to drill to make a hole for bolt
     
 step 4: Attach the brackets to the base
     
 step 5: attach felt or rubber feet to the base (if desired)
 Total cost: ~$71 for two dual headphone holders


----------



## i luvmusic 2

I knew it i saw those parts when i was there with my wife...........


----------



## DDDamian

allanmarcus said:


> That, I made. Here's how:
> 
> 
> Spoiler: Warning: Spoiler!
> ...


 
  
 Saved and tucked away for next time I'm near one! Thanks for the detailed How-To - nice job!


----------



## Allanmarcus

charliemotta said:


> @Allanmarcus
> What king of headband cover are you using on your cans??




Stock beyerdynamic covers.


----------



## Allanmarcus

A little video showing how I made crack in under two minutes!


----------



## PETEREK

My Crack is coming along too. I have a new knob to put on, but the diameter of the hole is too small for the potentiometer nub, so I will be drilling it out at work in a couple days. You can see the knob next to the potentiometer in the pictures, it will look great! I have attached some floor spikes to the bottom so the Crack can breathe a little better, I have to paint the spike stands because they got a little scratched up from bouncing around during shipment, they're black.


----------



## ohcrapgorillas

Tube rolling has been really interesting and fun... the Genalex Gold Lion and RCA clear top 12AU7 are both absolutely fantastic tubes. I think so far the Gold Lion is my favorite, it's so holographic and the bass is so amazing, but the RCA does such an amazing job at vocals and treble that it's also great to listen to, it really makes magic with the HD650. I also just scored a NOS/NIB Hewlett Packard-branded Amperex 12AU7 for $35 on eBay last night. Looking forward to that a lot!
  
 I'm having trouble locating a good replacement power tube though. I have a 5998 and I love it, but I kind of want a backup 6080 besides the stock tube which has become microphonic and is now just being used for burning in my preamp tubes. I'd prefer to pay less than $40 for it. I've heard the Sylvania winged C tube is great, but I've had a really hard time locating one (on ebay everything is being sold in pairs). The RCA 6AS7G also has some decent reviews around these parts, but I thought I'd ask and see if anyone has any good recommendations for a great bang-for-buck power tube to pair with the HD6x0.
  
 In other notes, originally I preferred the HD600 for its soundstage but now that the preamp tubes have started to open up and the HD650 doesn't sound as congested, I'm finding I strongly prefer the HD650.


----------



## ZachPtheDude

I was able to purchase a Tung Sol 6080wb off ebay for $50 and I can't recommend it enough


----------



## Keithpgdrb

ohcrapgorillas said:


> Tube rolling has been really interesting and fun... the Genalex Gold Lion and RCA clear top 12AU7 are both absolutely fantastic tubes. I think so far the Gold Lion is my favorite, it's so holographic and the bass is so amazing, but the RCA does such an amazing job at vocals and treble that it's also great to listen to, it really makes magic with the HD650. I also just scored a NOS/NIB Hewlett Packard-branded Amperex 12AU7 for $35 on eBay last night. Looking forward to that a lot!
> 
> I'm having trouble locating a good replacement power tube though. I have a 5998 and I love it, but I kind of want a backup 6080 besides the stock tube which has become microphonic and is now just being used for burning in my preamp tubes. I'd prefer to pay less than $40 for it. I've heard the Sylvania winged C tube is great, but I've had a really hard time locating one (on ebay everything is being sold in pairs). The RCA 6AS7G also has some decent reviews around these parts, but I thought I'd ask and see if anyone has any good recommendations for a great bang-for-buck power tube to pair with the HD6x0.
> 
> In other notes, originally I preferred the HD600 for its soundstage but now that the preamp tubes have started to open up and the HD650 doesn't sound as congested, I'm finding I strongly prefer the HD650.



This is so interesting to me. In every situation, I have always preferred the hd600.


----------



## Mich4lle

>





ohcrapgorillas said:


> I also just scored a NOS/NIB Hewlett Packard-branded Amperex 12AU7 for $35 on eBay last night.


 
  
 I would be very interested to hear what you think of that Amperex tube compared to your other tubes. I heard it is fantastic.


----------



## hdtv00

Can anyone give me a rundown of a crack with speedball vs one stock. How it's different what a person gains from staying stock. I've read the tubes stand out more if stock have a bigger effect. But I"m not sure what that means.


----------



## JamieMcC

hdtv00 said:


> Can anyone give me a rundown of a crack with speedball vs one stock. How it's different what a person gains from staying stock. I've read the tubes stand out more if stock have a bigger effect. But I"m not sure what that means.


 
  
 Its been ages since I compared the two the Speedball offers a noticeable improvement over the stock Crack but its more of a refinement of what the stock Crack is already good at rather than a different sound imo.
  
 Stock Crack has a raw (in a good way) dynamism and musicality that's very engaging, Speedball extends the edges of the dynamics, refines them tightening the sound up and I think lowers the noise floor which results in additional clarity and resolution. The trade off is you may miss a little bit of that raw edginess charm along the way for a technically more capable amp. 
  
 I am kind of sitting on the fence on the tube effects of stock vs Speedball while the sonic changes of using different makes of tubes may be slightly more noticeable in a stock Crack if and when you start getting more into the higher end premium tubes the Speedball I feel helps reveal more of their benefits.
  
 Not much help really but I have spent many enjoyable hours with both 
	

	
	
		
		

		
			





 the Speedball is pretty straight forward to add later on.


----------



## Maxhawk

Crosspost to my 2nd Crack pcb:  4PDT switch to swap between 5687 and 12AU7 variant tubes. It changes the wiring as well as swaps between the standard red LEDs and blue LEDs required for the 5687:
  
 http://bottlehead.com/smf/index.php?topic=5989.210


----------



## Jeb Listens

Hello Bottleheaders, 
  
 Just wondered if any one would be able to suggest a neat and simple way to fasten the top plate to the wooden base that won't compromise the clean look too much?  I was thinking of drilling holes  in the plate and securing to wooden blocks on the inside of the wooden frame, but it seems like it might all get a bit tight under there especially with the possibility of future upgrades.
  
 or do you all just leave the plate resting on the frame?  It seems that for removing tubes & headphones it might be useful to have it secured - as well as to deter to curious hands. 
  
 Any ideas/experience/pictures would much appreciated.
  
 Thanks!
  
 Jeb.


----------



## lextek

jeb listens said:


> Hello Bottleheaders,
> 
> Just wondered if any one would be able to suggest a neat and simple way to fasten the top plate to the wooden base that won't compromise the clean look too much?  I was thinking of drilling holes  in the plate and securing to wooden blocks on the inside of the wooden frame, but it seems like it might all get a bit tight under there especially with the possibility of future upgrades.
> 
> ...




I've had my Crack for a few years and have swapped many tubes with out any issues. I really don't see any reason to secure the plate to the base. I just hold the the plate down and swap the tube.


----------



## JamieMcC

jeb listens said:


> Hello Bottleheaders,
> 
> Just wondered if any one would be able to suggest a neat and simple way to fasten the top plate to the wooden base that won't compromise the clean look too much?  I was thinking of drilling holes  in the plate and securing to wooden blocks on the inside of the wooden frame, but it seems like it might all get a bit tight under there especially with the possibility of future upgrades.
> 
> ...


 
  
  
 A easy and inexpensive way to do this is to run a small thin bead (1-2mm)of clear silicon bathroom sealant all around the top plate recess on the wood enclosure and then put your top plate straight on top.
 It will hold the base to the top plate and if required later a gentle push in one of the corners would be enough to break the bond and free the top again.


----------



## Jeb Listens

Thanks guys, the silicon sounds like a nice impermanent solution. 
  
 Cheers!


----------



## krikor

jeb listens said:


> Hello Bottleheaders,
> 
> Just wondered if any one would be able to suggest a neat and simple way to fasten the top plate to the wooden base that won't compromise the clean look too much?  I was thinking of drilling holes  in the plate and securing to wooden blocks on the inside of the wooden frame, but it seems like it might all get a bit tight under there especially with the possibility of future upgrades.
> 
> ...


 
 Not sure it is a "clean" enough solution, but I used some leftover pan-head cabinet screws I had sitting around and mounted them just outside the edge of the top plate. I drilled pilot holes and then widened the top of the openings a bit so that the screws would sit countersunk below the outer edge of the base cabinet. Probably used too many with three on each side, one up front and one in the back - but I was taking it to a headphone meet and didn't want to constantly police the changing of headphones and sources.


----------



## Jeb Listens

krikor said:


> Not sure it is a "clean" enough solution, but I used some leftover pan-head cabinet screws I had sitting around and mounted them just outside the edge of the top plate. I drilled pilot holes and then widened the top of the openings a bit so that the screws would sit countersunk below the outer edge of the base cabinet. Probably used too many with three on each side, one up front and one in the back - but I was taking it to a headphone meet and didn't want to constantly police the changing of headphones and sources.


 
  
 Oh cool, krikor, very nicely done - that's exactly the kind of solution I was looking for!
  
 If it's not too much trouble - would you mind showing an over-head closer-up view?  No worries, if not, I think I have the general idea.  
  
 I understand about taking it to a headphone meet - good thinking.


----------



## krikor

jeb listens said:


> Oh cool, krikor, very nicely done - that's exactly the kind of solution I was looking for!
> 
> If it's not too much trouble - would you mind showing an over-head closer-up view?  No worries, if not, I think I have the general idea.
> 
> I understand about taking it to a headphone meet - good thinking.


 
 I'll take a shot when I get a chance today - drinking my coffee and waking up right now


----------



## Allanmarcus

jeb listens said:


> Hello Bottleheaders,
> 
> Just wondered if any one would be able to suggest a neat and simple way to fasten the top plate to the wooden base that won't compromise the clean look too much?  I was thinking of drilling holes  in the plate and securing to wooden blocks on the inside of the wooden frame, but it seems like it might all get a bit tight under there especially with the possibility of future upgrades.
> 
> ...


 
  
 Another good reason not to secure the plate. If you want to work on the underside to upgrade parts, you can easily remove the tubes, then flip the plate over, of just remove the place and put it on a towel on your workbench.


----------



## krikor

jeb listens said:


> Oh cool, krikor, very nicely done - that's exactly the kind of solution I was looking for!
> 
> If it's not too much trouble - would you mind showing an over-head closer-up view?  No worries, if not, I think I have the general idea.
> 
> I understand about taking it to a headphone meet - good thinking.


 
 Here you go...


----------



## Jeb Listens

krikor said:


> Here you go...


 
  
 Thanks kirkor - really appreciate that.  It's a nice solution & great job - especially so close to the edge of the wood like that.


----------



## grausch

I recently rebuilt my Crack and here is a pic of the underside. Almost every part has been replaced, or will be replaced for this build. More details can be found on the Bottlehead website at http://bottlehead.com/smf/index.php?topic=7945.0. Haven't had much time to listen yet, but may spend some quality time with this amp later this week.


----------



## daltonljj

Was looking through list of upgrades that could be done on the crack. Did some calculation on the total cost and realized it adds up to nearly 2x as much as the crack with speedball itself if you choose premium parts. With all that upgrade would it even out perform a bottlehead mainline at stock configuration? Any opinions on this?


----------



## i luvmusic 2

I never heard the Mainline but i doubt it if the Crack can out perform the Mainline,The mainline designed is more refined than the crack but then i'am not an engineer so i could be wrong however the knowledge i learned  from building the  CRACK and S.E.X. is priceless.


----------



## bigfatpaulie

daltonljj said:


> Was looking through list of upgrades that could be done on the crack. Did some calculation on the total cost and realized it adds up to nearly 2x as much as the crack with speedball itself if you choose premium parts. With all that upgrade would it even out perform a bottlehead mainline at stock configuration? Any opinions on this?


 
  
 "Outperform"?  In what sense?  The Mainline and the Crack have such different sounds.  Both are excellent amps, but they are so very, very different.


----------



## ZachPtheDude

I'm starting to get an itch for a new project...makes me really want to buy the S.E.X. kit, but as a college student I can't afford it without selling my hot rodded crack...decisions, decisions.

I love how the crack sounds but I'm going to be building some sensitive speakers and I'd love to have the option of utilizing both speakers and headphones on one amp.


----------



## PETEREK

Does anyone here ever have issues with distortion through planars when using the Crack? My T50RPs and a TH500Rp that I have here distort heavily when it is near or passed half volume. My T50RPs sound great with zero issues off other amps at any volume so it cannot be the headphones themselves. My dynamic headphones sound perfect off the Crack though.


----------



## ZachPtheDude

peterek said:


> Does anyone here ever have issues with distortion through planars when using the Crack? My T50RPs and a TH500Rp that I have here distort heavily when it is near or passed half volume. My T50RPs sound great with zero issues off other amps at any volume so it cannot be the headphones themselves. My dynamic headphones sound perfect off the Crack though.




Impedence mismatch and the crack doesnt provide the current necessary to really power planar, and/or low impedence headphones.


----------



## ZachPtheDude

Put up a classified for my heavily modded crack if anyone reading this thread is interested but not confident with a soldering iron.

*if this post is against the forum rules I will delete it*


----------



## DDDamian

zachpthedude said:


> I'm starting to get an itch for a new project...makes me really want to buy the S.E.X. kit, but as a college student I can't afford it without selling my hot rodded crack...decisions, decisions.
> 
> I love how the crack sounds but I'm going to be building some sensitive speakers and I'd love to have the option of utilizing both speakers and headphones on one amp.


 
 I have the Crack and the S.E.X. The latter sounds great with my two planars (see sig). But the Crack is meant solely for high impedance cans and is dedicated to my 650's.
  
 The S.E.X is definitely for you, and will still drive 650's or the right small monitors, Very flexible and a nice amp. Will save you on tubes too.


----------



## ohcrapgorillas

Listening to the HD600 and with a 5998, I've actually had a really hard time deciding whether the Genalex Gold Lion or the Hewlett-Packard branded Amperex (made in Holland) I got sounds better. I really love the Gold Lion, personally. It was the most unimpressive at first, but once it opens up it's really holographic and has great mids and bass, it has a somewhat rich sound in the mids that reminds me in a way of the LCD2 and is a tinge mid forward. The Amperex is just starting to open up after a few nights of burn-in and the clarity and extension in the treble are really impressive, beautiful mids, everything sounds natural through and through. I still like the bass and soundstage of the Gold Lions better though.

 I have to say that the Clear Top doesn't impress me as much with the HD600, the bass is too lean. Reminds me of the Etymotic HF5. On the HD650, however, it's a different story: wow wow wow, what a combo. I almost want to keep my HD650 and Clear Top just because it sounded so freaking good.


----------



## daltonljj

The Gold lion was the first tube i bought don't really like it with the HD800 nice mids and bass like you mentioned but it kinda rounds off the sparkle that the HD800 has. In fact i preferred the stock GE 12au7 provided over the gold lion. Currently using the RCA clear tops and to my ears it seem to be slightly more spacious and more crisp.


----------



## coastal1

I just ordered a Bottlehead Crack w/ Speedball and stepped attenuator from the forums here.  Very excited to give it a try w/ my Senn HD 650.
  
 I'm a longtime music lover, but young kids make stereo listening very limited these days and brought me to headphones.  This is my first tube amp for headphones or otherwise.  Is there Bottlehead 101 user guide (or for tube amps in general)?  Fortunately someone else built mine so the work is done, but I also want to make sure I use and maintain it correctly.  I know enough to keep it far away from the kids and have picked up some great recs on tubes, but that's about the extent of my knowledge.  Will continue reading the threads here and on the BH forum but a lot of the stuff will be useful down the road but is above my head right now, so if there's an intro guide or list of do's an don't that would be very helpful.
  
 Thanks


----------



## Allanmarcus

I'm trying to set up my stuff to make for a quick and easy A/B test of amps. Here's what I have set up, and I'm interested in opinions on if this is valid. My concern is if the common elements of this set up can degrade the sound such that an A/B test is not valid.
  
 Mac -> USB -> Dac-IT -> RCA cable splitter ->
  
 RCA cable splitter -> crack -> Fiio HS2 switch
 RCA cable splitter -> NAD D3020 -> Fiio HS2 switch
  
 Fiio HS2 switch -> headphones
  
 I'm using identical cables between the dac and the amps, and between the amps and the HS2 switch.
  
 This set up, once SPL leveled (by ear) allows be to play a track and simply switch the HS2 between 1 and 2 to hear the different amps.


----------



## daltonljj

coastal1 said:


> I just ordered a Bottlehead Crack w/ Speedball and stepped attenuator from the forums here.  Very excited to give it a try w/ my Senn HD 650.
> 
> I'm a longtime music lover, but young kids make stereo listening very limited these days and brought me to headphones.  This is my first tube amp for headphones or otherwise.  Is there Bottlehead 101 user guide (or for tube amps in general)?  Fortunately someone else built mine so the work is done, but I also want to make sure I use and maintain it correctly.  I know enough to keep it far away from the kids and have picked up some great recs on tubes, but that's about the extent of my knowledge.  Will continue reading the threads here and on the BH forum but a lot of the stuff will be useful down the road but is above my head right now, so if there's an intro guide or list of do's an don't that would be very helpful.
> 
> Thanks


 
  
 I'm rather new to upgrading stuff too but here are some of the mods i'm aware of. Some of which i've completed.
  
 1) Speedball (Highly recommended and should be the first thing you add imo)
 2) Tube rolling
 3) Changing stock potentiometer with a stepped attenuator 2 types available the regular ones and the shunt type (IMO shunt type better)
 4) replacing capacitors *don't replace for the sake of replacing* cos stock caps are alr of good quality. Film type capacitors are good but takes up tonnes of space so make sure they all fit. Also take note of the voltage rating and all.
 5) Add bypass caps for the last power supply cap.
 6) Replace the last 270 ohm resistor in power supply with a choke (need to drill 2 holes to mount the choke) Choke to use is triad C-7x
  
 Last but not least in my built a killer custom case to make your crack look sexy and unique to you and only you ... lol
  
 hope this helps i'm still new to all this and still researching. Bottlehead forum has tonnes of information too.


----------



## FunyunBreath

coastal1 said:


> I just ordered a Bottlehead Crack w/ Speedball and stepped attenuator from the forums here.  Very excited to give it a try w/ my Senn HD 650.
> 
> I'm a longtime music lover, but young kids make stereo listening very limited these days and brought me to headphones.  This is my first tube amp for headphones or otherwise.  Is there Bottlehead 101 user guide (or for tube amps in general)?  Fortunately someone else built mine so the work is done, but I also want to make sure I use and maintain it correctly.  I know enough to keep it far away from the kids and have picked up some great recs on tubes, but that's about the extent of my knowledge.  Will continue reading the threads here and on the BH forum but a lot of the stuff will be useful down the road but is above my head right now, so if there's an intro guide or list of do's an don't that would be very helpful.
> 
> Thanks


 
  
 As far as do's and dont's here's a few helpful tips that pertain to the BH crack (and tube amps in general)
  
 -Give the amp a few minutes to warm up before listening, it will sound it's best after about 15-20 minutes
 -Always power down and unplug the amp before swapping tubes
 -Give your tubes about 10-15 minutes to cool before unplugging them
 -Try to keep the amp far away from digital devices and routers to minimize tube noise
 -With the Crack it's not necessary to unplug your headphones when powering it on/off but I at least turn the volume knob all the way down first


----------



## FunyunBreath

allanmarcus said:


> I'm trying to set up my stuff to make for a quick and easy A/B test of amps. Here's what I have set up, and I'm interested in opinions on if this is valid. My concern is if the common elements of this set up can degrade the sound such that an A/B test is not valid.
> 
> Mac -> USB -> Dac-IT -> RCA cable splitter ->
> 
> ...


 
  
 That's pretty much the exact A/B setup I use (just with a different switch)
  
 If you want to get the volume exact between both amps to the headphones a nice trick is to download a decibel meter app onto your phone. Lay your phone mic next to the driver and use a 1K sine wave like this to level both amps: https://www.youtube.com/watch?v=3yQcXlvccCI
  
 Doing A/B tests like this really reveals quite a bit in my opinion. Sometimes the differences in sound between amps isn't at all as big as we think.


----------



## coastal1

funyunbreath said:


> As far as do's and dont's here's a few helpful tips that pertain to the BH crack (and tube amps in general)
> 
> -Give the amp a few minutes to warm up before listening, it will sound it's best after about 15-20 minutes
> -Always power down and unplug the amp before swapping tubes
> ...


 
  
 Thanks, very helpful.


----------



## Allanmarcus

funyunbreath said:


> As far as do's and dont's here's a few helpful tips that pertain to the BH crack (and tube amps in general)
> 
> -Give the amp a few minutes to warm up before listening, it will sound it's best after about 15-20 minutes
> -Always power down and unplug the amp before swapping tubes
> ...


 
  
 I used one of them fancy infrared "gun" thermometers, and my power tube was way over 200 degrees! Be careful.


----------



## Allanmarcus

funyunbreath said:


> That's pretty much the exact A/B setup I use (just with a different switch)
> 
> If you want to get the volume exact between both amps to the headphones a nice trick is to download a decibel meter app onto your phone. Lay your phone mic next to the driver and use a 1K sine wave like this to level both amps: https://www.youtube.com/watch?v=3yQcXlvccCI
> 
> Doing A/B tests like this really reveals quite a bit in my opinion. Sometimes the differences in sound between amps isn't at all as big as we think.


 
  
 Yep. I hardy hear any difference between the crack and the D3020, but I'm over 50 . My 23 year son says there is a very slight difference, and he actually has pretty good hearing. We used DT-770-250, DT-990-250, and Audeze LCD-3 (pre-fazor) to test. The reviews of the D3020 are pretty good, and report a "tube like" warmth, so maybe it is. Also, I'm using all stock stuff and no speedball (yet). I look forward to doing this test at the Denver meet.
  
 To tell you the truth, I got the crack for fun and "cool" factor. Sort of like this comic:


----------



## Jimmy24

Perfect combo! 
  

  
*5998 + Siemens 5814a*


----------



## daltonljj

Just curious. Would it be advisable to make the top plate out of acrylic. Will it run so hot that it causes the acrylic to warp ?


----------



## grausch

Well, the top plate is also used for grounding, so I assume you want to make it from something that conducts electricity.


----------



## PETEREK

daltonljj said:


> Just curious. Would it be advisable to make the top plate out of acrylic. Will it run so hot that it causes the acrylic to warp ?


 
 It would have to reach above 300 degrees fahrenheit for it to warp acrylic, which I don't think it would. But as Grausch said, you would have to ground many things for it to work.


----------



## daltonljj

peterek said:


> It would have to reach above 300 degrees fahrenheit for it to warp acrylic, which I don't think it would. But as Grausch said, you would have to ground many things for it to work.


 
  
 Thanks   ... haha  plan to connect all the ground point to a grounding post


----------



## FunyunBreath

allanmarcus said:


> Yep. I hardy hear any difference between the crack and the D3020, but I'm over 50 . My 23 year son says there is a very slight difference, and he actually has pretty good hearing. We used DT-770-250, DT-990-250, and Audeze LCD-3 (pre-fazor) to test. The reviews of the D3020 are pretty good, and report a "tube like" warmth, so maybe it is. Also, I'm using all stock stuff and no speedball (yet). I look forward to doing this test at the Denver meet.
> 
> To tell you the truth, I got the crack for fun and "cool" factor. Sort of like this comic:


 
  
 Yeah NAD stuff is pretty awesome! I scored a vintage NAD 7020 receiver on craigslist a while back and it sounds phenomenal with bookshelf speakers and HD650's. Doing an A/B test between it and the Crack and its almost uncanny how similar they sound.
  
 Also did an A/B test with the Crack and a friend's Asgard a few weeks ago and they sound fairly similar as well. Asgard is a tad brighter with cleaner highs, but missing some of the gorgeous low-mids the crack offers.


----------



## Allanmarcus

funyunbreath said:


> Yeah NAD stuff is pretty awesome! I scored a vintage NAD 7020 receiver on craigslist a while back and it sounds phenomenal with bookshelf speakers and HD650's. Doing an A/B test between it and the Crack and its almost uncanny how similar they sound.
> 
> Also did an A/B test with the Crack and a friend's Asgard a few weeks ago and they sound fairly similar as well. Asgard is a tad brighter with cleaner highs, but missing some of the gorgeous low-mids the crack offers.


 

 I also have a 7020, in the garage! It is good. I have a Magni at work. I need to bring it home to see if there is a difference there. there's got to be a difference with something!


----------



## ZachPtheDude

If anyone is considering giving crack a try but they don't feel comfortable with an iron I dropped $50 off the asking price on my crack and collection of input and power tubes, and I'm always interested in trading for a DAC and cash.

Going to miss it, but I need output transformers to drive low impedance phones, and a set of desktop speakers I am going to build.


----------



## Jeb Listens

jimbo24 said:


> Perfect combo!
> 
> 
> 
> *5998 + Siemens 5814a*


 
  
 Nice amp.  Nice tubes.  Nice flooring.


----------



## coastal1

Just got one of these w/out power cord. Is a standard power cord (for computers, tvs, etc) compatible, or is there a certain kind of power cord I need to use?


----------



## FunyunBreath

Any standard 10 amp 125V cord will work


----------



## coastal1

Thanks



funyunbreath said:


> Any standard 10 amp 125V cord will work


T


----------



## grausch

Modded the PSU - Details are over on the Bottlehead forums (http://bottlehead.com/smf/index.php?topic=7945.0).
  
 Some pictures of the modifications:


----------



## PETEREK

grausch said:


> Modded the PSU - Details are over on the Bottlehead forums (http://bottlehead.com/smf/index.php?topic=7945.0).
> 
> Some pictures of the modifications:


 
 Hey I'm liking the sleeving over the wires! I like some originality.


----------



## grausch

peterek said:


> Hey I'm liking the sleeving over the wires! I like some originality.


 
 Thank you, however, I can't claim this as an original idea. I got my inspiration from two Bottlehead builds - links are http://bottlehead.com/smf/index.php?topic=6855.0 and http://bottlehead.com/smf/index.php?topic=2349.0.
  
 The wire comes from Tube Depot (https://www.tubedepot.com/t/diy-central/wire-and-cable) and is the 18 awg solid cloth wire. However, it takes up a lot more space and I would recommend the 20 awg. It is a lot harder to melt the insulation on the cloth-covered wire, which makes it much easier to get a clean look.
  
 I believe the placement of the remaining 2 electrolytic PS caps is an original idea - I really needed every little bit of space I could get to mount that 270uf cap and those two caps kept on being in the way. Using the K75-10s as mounting points for the 270uf cap is also an original idea. Not sure how many people are using 2 of those to bypass the last PS cap.
  
 My first attempt at the Crack sounded good, but did not look quite as nice (melted insulation, messy wiring, etc). The current build fixes those issues, but to be honest, I have spent more time working on it than actually listening to it and I still have several upgrades planned...that being said, it is great fun planning and implementing the upgrades while keeping the magic smoke inside the amp.


----------



## JacobLee89

Did they recycle drinks cans to house those capacitors? They're huge!


----------



## grausch

jacoblee89 said:


> Did they recycle drinks cans to house those capacitors? They're huge!


 
 Nah, those are baby caps... 
	

	
	
		
		

		
			





 For manly caps, have a look at http://bottlehead.com/smf/index.php?topic=4775.msg45699#msg45699.
  
 They are pretty big though, but are 270uf / 400V. The 220uf Jantzen is not much smaller. I could have gotten a 200uf / 250V Mundorf MCap which is a little smaller, but with all the other upgrades the Jantzen's price became the determining factor.


----------



## NightFlight

funyunbreath said:


> Any standard 10 amp 125V cord will work


 
  
 My 2c here on this topic.
  
 I can't account for it... perhaps its because the crack doesn't have a regulated power supply - but I found it definitely benefits from a heavier gauge power cord.  I found 14AWG for me was nearly as revealing as swapping out the stock pot with a switched network. I've been warned away from even higher gauge like 10AWG, the potential result being the amp sounding more dark and sloppy.
  
 My guess is that this effect would be mitigated somewhat by swapping out the stock bridge rectifier with Cree replacements... Just a shot in the dark, but I definitely have that lined up as my next mod. I would like to hear what a Crack can do with better power supply like the Mainline.


----------



## LepakVT

Sigh. I had always read great things about Bottlehead's customer support and service, but I've been disappointed here recently.
  
 E-mailed my first request for a few replacement parts (LED, resistors) 6 business days ago and still haven't heard anything back. Sent a different e-mail to replacementparts, and now it's been another 2 business days without any response either.
  
 I'm trying to be patient, but I just want to listen to my new amp!


----------



## FunyunBreath

Did you send to the right address? I just emailed last week about replacement parts after fubar-ing a speedball board and they sent them out 2 days later.


----------



## Allanmarcus

lepakvt said:


> Sigh. I had always read great things about Bottlehead's customer support and service, but I've been disappointed here recently.
> 
> E-mailed my first request for a few replacement parts (LED, resistors) 6 business days ago and still haven't heard anything back. Sent a different e-mail to replacementparts, and now it's been another 2 business days without any response either.
> 
> I'm trying to be patient, but I just want to listen to my new amp!




I'm pretty sure ther are a very small operation. They were the big THE show, so they probably are behind on their email.


----------



## LepakVT

funyunbreath said:


> Did you send to the right address? I just emailed last week about replacement parts after fubar-ing a speedball board and they sent them out 2 days later.


 
  
 Yeah. When I first e-mailed Eileen, she actually immediately replied and said she'd prepare me a Paypal invoice for parts and shipping. But I never got one and haven't heard back. E-mailed her again last night with no response yet today.
  
 Then I got a separate mass e-mail from Josh (replacementparts) about some faulty transistors Bottlehead received, and how they are sending out replacement transistors. So I replied back over the weekend and asked him if he could just bundle the other replacement parts I need in that same shipment. Haven't heard back yet on Tuesday.
  
  
 Edit: I'm just venting my minor disappointments. I want to clear off the part of my table covered with a soldering iron and various tools. And listen to the Crack of course!


----------



## DDDamian

lepakvt said:


> Yeah. When I first e-mailed Eileen, she actually immediately replied and said she'd prepare me a Paypal invoice for parts and shipping. But I never got one and haven't heard back. E-mailed her again last night with no response yet today.
> 
> Then I got a separate mass e-mail from Josh (replacementparts) about some faulty transistors Bottlehead received, and how they are sending out replacement transistors. So I replied back over the weekend and asked him if he could just bundle the other replacement parts I need in that same shipment. Haven't heard back yet on Tuesday.
> 
> ...


 
 I just ordered an S.E.X iron upgrade and replacement A/C rocker switch yesterday - Eileen was all over it in minutes. Guessing it was the show that slowed things up for ya. Happy soldering


----------



## coastal1

nightflight said:


> My 2c here on this topic.
> 
> I can't account for it... perhaps its because the crack doesn't have a regulated power supply - but I found it definitely benefits from a heavier gauge power cord.  I found 14AWG for me was nearly as revealing as swapping out the stock pot with a switched network. I've been warned away from even higher gauge like 10AWG, the potential result being the amp sounding more dark and sloppy.
> 
> My guess is that this effect would be mitigated somewhat by swapping out the stock bridge rectifier with Cree replacements... Just a shot in the dark, but I definitely have that lined up as my next mod. I would like to hear what a Crack can do with better power supply like the Mainline.


 
 Is your 14AWG cord still 10amp/125volt? Any benefit (or risk) to using a 14awg cord thats 15amp/125volt?


----------



## NightFlight

coastal1 said:


> Is your 14AWG cord still 10amp/125volt? Any benefit (or risk) to using a 14awg cord thats 15amp/125volt?


 
  
 The current carrying capacity goes up with the gauge. Or in the electrical world, if you require a longer extension cord, say 100+ feet, you would want to increase the gauge/diameter to reduce the overall resistance accumulated with total length (correct me if I'm wrong here). The current pulled by your headphone amp is completely moot in this respect and ratings do not even really come into play. What is happening to clean up the signal by changing out the power cord is a subject which will polarize participants in the discussion and inevitably end in argument between subjectivists and objectivists. I do not have physics or maths to convincingly explain what happens, other than say I hear a change. *shrug*.  Having recently joined the subjectivist club, I no longer care. If I hear it, I go with it.


----------



## coastal1

nightflight said:


> The current carrying capacity goes up with the gauge. Or in the electrical world, if you require a longer extension cord, say 100+ feet, you would want to increase the gauge/diameter to reduce the overall resistance accumulated with total length (correct me if I'm wrong here). The current pulled by your headphone amp is completely moot in this respect and ratings do not even really come into play. What is happening to clean up the signal by changing out the power cord is a subject which will polarize participants in the discussion and inevitably end in argument between subjectivists and objectivists. I do not have physics or maths to convincingly explain what happens, other than say I hear a change. *shrug*.  Having recently joined the subjectivist club, I no longer care. If I hear it, I go with it.


 
 Works for me.  Thanks


----------



## Mich4lle

Hello everyone,


 


I am having a problem with the nut that holds down my RCA jacks. They keep coming loose and it is at the point now where I can't get a signal through my amp. Is it possible that I just buy two new nuts to screw them on with? If it is, what size and material should they be.


 


Thank you in advance for the help.


----------



## DDDamian

mich4lle said:


> Hello everyone,
> 
> I am having a problem with the nut that holds down my RCA jacks. They keep coming loose and it is at the point now where I can't get a signal through my amp. Is it possible that I just buy two new nuts to screw them on with? If it is, what size and material should they be.
> 
> Thank you in advance for the help.


 
 Haven't measured the threads but two options: contact Bottlehead or use a dab of Loctite and re-tighten. Hope either one helps.


----------



## dreame77

Hello everyone!
  
 For about a year I am happy with Beyerdynamic T1 on Bottlehead Crack!!!
 Thanks to everyone who suggested me to buy T1 for Crack!
 Although recently I feel the amount and impact of bass for me is not enough. 
 I wander will Speedball Upgrade fix it?
  
  
 And... what do you think or know about AKG k612 Pro paired with Crack?
  
 Thanks in advance!


----------



## DDDamian

Not sure what you mean by "fixing" the bass, but post-Speedball it seemed a bit tighter to me,


----------



## JamieMcC

dreame77 said:


> Hello everyone!
> 
> For about a year I am happy with Beyerdynamic T1 on Bottlehead Crack!!!
> Thanks to everyone who suggested me to buy T1 for Crack!
> ...


 
  
 A inexpensive thing to try here is adding the Triad C7X choke mod it has a noticeable effect on the bass costs about $15 or less and is easily reversible. It offers a easily implemented, inexpensive and effective improvement imo.  Some discussion and instructions here.
  
http://bottlehead.com/smf/index.php?topic=6030.0
  
 A Google search of Crack c7x  has some other links as well


----------



## PETEREK

I'm putting my Crack up for sale today. I need only one amp that will power my dynamics AND orthos, so the Crack+speedball has got to go. Keeping the Gustard H10.


----------



## coastal1

peterek said:


> I'm putting my Crack up for sale today. I need only one amp that will power my dynamics AND orthos, so the Crack+speedball has got to go. Keeping the Gustard H10.


 
  
 Is your decision to go with the Gustard H10 purely compatibility with other HP vs. the Crack, or are there other things you like better about the H10?  Curious as the H10 is on Massdrop this week.


----------



## PETEREK

coastal1 said:


> Is your decision to go with the Gustard H10 purely compatibility with other HP vs. the Crack, or are there other things you like better about the H10?  Curious as the H10 is on Massdrop this week.



It's mainly for compatibility, but they are both great amps that deliver quality well above their price points. I think the Gustard is better in the mid range, the Crack seems a bit empty there, but it makes the stage slightly wider sounding. I'd be happy with either amp if they both powered all my headphones.


----------



## Koolpep

I have the H10 as well. And it's an amazing allrounder amp. If I could only have one amp, it would be the H10. Thankfully I can keep the Crack & SB as well and use it for the HD650, T90 and currently for a borrowed T1 
  
 Love the crack to bits. But the H10 is equally amazing....
  
 Cheers,
 K


----------



## coastal1

funyunbreath said:


> Yeah NAD stuff is pretty awesome! I scored a vintage NAD 7020 receiver on craigslist a while back and it sounds phenomenal with bookshelf speakers and HD650's. Doing an A/B test between it and the Crack and its almost uncanny how similar they sound.
> 
> Also did an A/B test with the Crack and a friend's Asgard a few weeks ago and they sound fairly similar as well. Asgard is a tad brighter with cleaner highs, but missing some of the gorgeous low-mids the crack offers.


 
  
 Interesting.  Any other vintage receivers that anyone's compared that sound like the Crack when paired with the HD650s?


----------



## listen4joy

i have problem with the crack. all worked well but suddenly.... i listen to music and only left side of the headphones working. right channel is silent as tomb... what should i do?


----------



## PETEREK

listen4joy said:


> i have problem with the crack. all worked well but suddenly.... i listen to music and only left side of the headphones working. right channel is silent as [COLOR=3E3E3E]tomb... what should i do?[/COLOR]



Try moving loosening your right RCA input and make sure it isn't grounding on the top plate then tighten it back up. If it isn't that, start jiggling wires until you find one that may have popped off somehow.

Edit: before that, try swapping the left and right RCA cables you have to make sure it's the amp that is having the problem. It would be annoying to mess around with the amp if it was the cable the whole time.


----------



## ohcrapgorillas

I'm actually really really impressed with the combo of the Crack and the Grado SR80i. Looking at the impedance, you'd think they'd be a terrible match but I'm lovin' _Eidolon_ by Rishloo. Holy prog!
  
 The stock power tube does best with the Grados, having that "warm, gooey tube sound" that so many people love. The 5998 is too close to solid state.
  
 As for the preamp tube, I thought I'd like the gold lion best with a wider soundstage and good bass slam and smooth mids, but the RCA clear top is really surprising.


----------



## PETEREK

ohcrapgorillas said:


> I'm actually really really impressed with the combo of the Crack and the Grado SR80i. Looking at the impedance, you'd think they'd be a terrible match but I'm lovin' _Eidolon_ by Rishloo. Holy prog!
> 
> The stock power tube does best with the Grados, having that "warm, gooey tube sound" that so many people love. The 5998 is too close to solid state.
> 
> As for the preamp tube, I thought I'd like the gold lion best with a wider soundstage and good bass slam and smooth mids, but the RCA clear top is really surprising.


 
 I would actually think Grados would love the Crack for the tube effects. They need some low end attention, and that is just what the tubes offer.


----------



## PETEREK

listen4joy said:


> i have problem with the crack. all worked well but suddenly.... i listen to music and only left side of the headphones working. right channel is silent as tomb... what should i do?


 
 Figure it out yet?


----------



## audiowize

listen4joy said:


> i have problem with the crack. all worked well but suddenly.... i listen to music and only left side of the headphones working. right channel is silent as tomb... what should i do?


 

 Post your resistances and voltages on the Bottlehead forum.


----------



## Mich4lle

Hello guys,
This forum is great and very helpful. I have another question about my RCA sockets though. They have lost all the thread on their screws and will not work anymore so I want to replace them. Where I live the only ones I can get seem to be the Furutech FP-900 and I want to know if they will work with the crack, because I can't see that grounding post on them.


----------



## audiowize

mich4lle said:


> Hello guys,
> This forum is great and very helpful. I have another question about my RCA sockets though. They have lost all the thread on their screws and will not work anymore so I want to replace them. Where I live the only ones I can get seem to be the Furutech FP-900 and I want to know if they will work with the crack


 
 These require a 10mm hole, which is a little bigger than the 3/8" hole on the Crack.  We did switch jacks some time ago to the Neutrik line, and consequently newer Cracks will come with a 10mm hole.  If you have access to a hand drill, you can very likely bore out your chassis hole to 10mm (hold that sucker down, don't let it move), as you only need to remove 1/2 a mm of material.
  
 The Furutech jacks look like a $63 version of a $4 pair of Chinese RCA jacks.  Caveat emptor.  That same manufacturer makes a gold over copper jack (the Furu is gold over brass) for $20 or so per pair.


----------



## Mich4lle

Oh but my crack is pretty new, I got it half way through last year (ordered it) so hopefully it will be the right size otherwise I can just drill the hole to the right size.
The problem with the RCA jacks is that as far as selection goes I kinda have to buy these ones because in South Africa I can't get hold of anything else. Are they a complete waste of money? Unless somebody has a suggestion.  But thanks for the help.


----------



## audiowize

mich4lle said:


> Oh but my crack is pretty new, I got it half way through last year (ordered it) so hopefully it will be the right size otherwise I can just drill the hole to the right size.
> The problem with the RCA jacks is that as far as selection goes I kinda have to buy these ones because in South Africa I can't get hold of anything else. Are they a complete waste of money? Unless somebody has a suggestion.  But thanks for the help.


 
  
 Your holes will be 3/8", but a 10mm drill bit will be easy to find in ZA. 
  
 These can be shipped to you, you'll be out less than $20.
  
http://www.ebay.com/itm/fskn2-2x-CMC-Gold-RCA-Female-Socket-Chassis-Connector-Phono-Copper-Plug-Amp-HiFi-/301311119184?pt=LH_DefaultDomain_3&hash=item46278acf50#shpCntId
  
 If you're in the bush, let me know where, I have a friend that's regularly traveling to the northeastern provinces.


----------



## Angerer

I'm looking to try new Tubes for my BHC, can anyone link me to a site where i can find some?
  
 Cheers


----------



## Hibuckhobby

peterek said:


> listen4joy said:
> 
> 
> > i have problem with the crack. all worked well but suddenly.... i listen to music and only left side of the headphones working. right channel is silent as [COLOR=3E3E3E]tomb... what should i do?[/COLOR]
> ...




Swap driver tube. If problem persists look for cold solder joint or burnt resistor. Go to bottlehead
Site...lots of knowlegable people there.
Hibuck....


----------



## PETEREK

Take a screw driver and just start jiggling wires with it until you find the one you thought had a good solder on it, but you were really just soldering everything but that wire. I'm willing to bet that's what happened, it was just making a connection until now.


----------



## skeptic

angerer said:


> I'm looking to try new Tubes for my BHC, can anyone link me to a site where i can find some?
> 
> Cheers




My best advice is to hunt and peck for deals on ebay. Start cheap with an old stock tung sol 12au7, still one of my favs, that can easily be found for under $20 and some mil spec 6080's, which can be had for <$10 each. Ramp up from there if need be.

Also, always bear in mind that if the cost of your crack, speedball, mods, tubes etc. starts to approach the cost of a mainline, you have gone off the trail and into the weeds.


----------



## DDDamian

skeptic said:


> My best advice is to hunt and peck for deals on ebay. Start cheap with an old stock tung sol 12au7, still one of my favs, that can easily be found for under $20 and some mil spec 6080's, which can be had for <$10 each. Ramp up from there if need be.
> 
> *Also, always bear in mind that if the cost of your crack, speedball, mods, tubes etc. starts to approach the cost of a mainline, you have gone off the trail and into the weeds.*


 
 So easily done


----------



## Angerer

skeptic said:


> My best advice is to hunt and peck for deals on ebay. Start cheap with an old stock tung sol 12au7, still one of my favs, that can easily be found for under $20 and some mil spec 6080's, which can be had for <$10 each. Ramp up from there if need be.
> 
> Also, always bear in mind that if the cost of your crack, speedball, mods, tubes etc. starts to approach the cost of a mainline, you have gone off the trail and into the weeds.


 
  
 Cheers fella,
  
 Will hit the bay when I finish my shift =)


----------



## 299792458

Like so many things in life I'm a day late and a dollar short, but is there any chance of another crack + free/discounted speedball sale in the near future? Wanting one badly but have a feeling I can't place an order until a sale returns.


----------



## heliosphann

Joined the club!!! Thanks to a fellow Head-Fi'er I now own a BHC w/Speedball. Listened to it for a while with my 650 and was utterly blown away.
  
 Now to collect some addition tubes.


----------



## Allanmarcus

skeptic said:


> My best advice is to hunt and peck for deals on ebay. Start cheap with an old stock tung sol 12au7, still one of my favs, that can easily be found for under $20 and some mil spec 6080's, which can be had for <$10 each. Ramp up from there if need be.
> 
> Also, always bear in mind that if the cost of your crack, speedball, mods, tubes etc. starts to approach the cost of a mainline, you have gone off the trail and into the weeds.


 

 How much difference is there between NOS old stock tung sol 12au7 and the new reissue version?


----------



## networkn

What's the estimate to build the speedball upgrade in?
 How many hours do I need to set aside?


----------



## Valhallatier

Hey i just joined the OTL+hd650 bandwagon, and i got the crack of course. Though i found out the stock tubes are a bit harsh on the highs, what should i get to make it smoother and perfect for my hd650? thanks
 and oh yeah im not using the speedball upgrade for various unimportant reasons


----------



## DDDamian

networkn said:


> What's the estimate to build the speedball upgrade in?
> How many hours do I need to set aside?


 
 It's not too bad at all - depending on your skills anywhere from 2-6hrs should do nicely.
  


valhallatier said:


> Hey i just joined the OTL+hd650 bandwagon, and i got the crack of course. Though i found out the stock tubes are a bit harsh on the highs, what should i get to make it smoother and perfect for my hd650? thanks
> and oh yeah im not using the speedball upgrade for various unimportant reasons


 
 The Mullards are generally considered a warm driver tube. Lot's of reading here : http://bottlehead.com/smf/index.php?topic=663.0
  
 Congrats on the new Cracks guys


----------



## networkn

I apologize if this is not considered appropriate, but is there an equivalent Solid State AMP of the same standard as say a Gustard H10, which is DIY and as well thought of as the crack amp (Which I am adding speed ball to today.


----------



## DDDamian

networkn said:


> I apologize if this is not considered appropriate, but is there an equivalent Solid State AMP of the same standard as say a Gustard H10, which is DIY and as well thought of as the crack amp (Which I am adding speed ball to today.




we are turning blue holding our breath


----------



## JamieMcC

networkn said:


> I apologize if this is not considered appropriate, but is there an equivalent Solid State AMP of the same standard as say a Gustard H10, which is DIY and as well thought of as the crack amp (Which I am adding speed ball to today.


 
  
 Dsavitsk's new Torpedo Mk3 is looking very interesting its a hybrid rather than solid state and currently undergoing some fine tuning prior to release. Looks like it might be a nice project. 
  
http://www.head-fi.org/t/570317/dsavitsk-beezar-torpedo-build-thread/735
  
 The Bottlehead Mainline is just out standing by the way if funds allow...


----------



## ZachPtheDude

I did a lot of research on the L'espressivo/original Torpedo, it's a less powerful SEX with much worse transformers, but they can be upgraded like Bottlehead. 

Both the sex and torpedo are parafeed designs. The torpedo is a good amp to build from scratch if you're itching for a new project.


----------



## Doc B.

Another hybrid possibility might be the Quickie and the Quicksand. It's two separate chassis but a creative person could squeeze it all into one. It's also off the grid, FWIW.


----------



## skeptic

Depending on how ambitious and technically inclined you are, the wire, dynalo/multiamp mk2 or one of the first watt designs (with an attenuator in front) would also be worthy solid state contenders, but these aren't kits and require real case work.  
  
 Having had populated wire boards sitting in my garage for god knows how long now, I can tell you there is a surprising dearth of pre-made/pre-cut amp chassis on the market for those of us who lack the skills to cut aluminum to fit, for example, a snap in IEC inlet.  Hard to appreciate how nice and well thought out bottlehead kits really are until you attempt to figure out your own enclosure.


----------



## JamieMcC

skeptic said:


> Depending on how ambitious and technically inclined you are, the wire, dynalo/multiamp mk2 or one of the first watt designs (with an attenuator in front) would also be worthy solid state contenders, but these aren't kits and require real case work.
> 
> Having had populated wire boards sitting in my garage for god knows how long now, I can tell you there is a surprising dearth of pre-made/pre-cut amp chassis on the market for those of us who lack the skills to cut aluminum to fit, for example, a snap in IEC inlet.  Hard to appreciate how nice and well thought out bottlehead kits really are until you attempt to figure out your own enclosure.


 
  
 Do you mean something like First Watts Amp camp amp it looks like a good intro into low cost solid state kit building.  I wonder if it is quiet enough for headphone use? The market seems awash with amps at the moment. Plenty of used options offering good value.
  
 Also another option is to check out GARAGE1217 they offer kits I believe the project Ember has had some good feed back not sure if they have any solid state offerings.


----------



## networkn

On page 15 of the Speedball Manual, there are two TIP50 assemblies to be made involving a heatsink. Annoyingly, my kit is incomplete as the second "lock" washer isn't present in my kit. 
  
 How important is it? Will it stop the product from working properly? Can I assemble it without this?


----------



## NightFlight

If your anxious to get it assembled, you can get away without the lock washer, so long as the shouldered washer is there to keep the screw head off the TIP50.  If the TIP50 makes contact with the heat sink when powered, it will self destruct. On the other hand you should be able to find a similar lock washer at Home Depot or Radio Shack, like stores.
  
 However,  you have to be aware of the risk. The lock washer is there to keep the screw from working loose after repeated temperature changes and the TIP50 loosing contact with the heat sink and again... self-destructing through thermal runaway because it can't cool. That will happen eventually if you don't have a lock washer.  How long? Somewhere between a few days and a few years.


----------



## Mich4lle

audiowize said:


> Your holes will be 3/8", but a 10mm drill bit will be easy to find in ZA.
> 
> These can be shipped to you, you'll be out less than $20.
> 
> ...


 
 Sorry for taking so long to reply, thank you for the help, I was able to get those Furutech RCA's for a really good price, so I thought "Why not"
 I get it, is probably a bit ridiculous but whatever , thank for offering help about getting some RCA's to me though.
 I still have the question about how to ground those Furutech ones,from that picture can anyhow see how to? or does anyone have any experience with them?


----------



## ohcrapgorillas

valhallatier said:


> Hey i just joined the OTL+hd650 bandwagon, and i got the crack of course. Though i found out the stock tubes are a bit harsh on the highs, what should i get to make it smoother and perfect for my hd650? thanks
> and oh yeah im not using the speedball upgrade for various unimportant reasons


 
 IMO the RCA clear top is a fantastic 12AU7 replacement for the HD650. It sucks during burn-in but once it gets going, it opens up the top end and sounds really natural, good soundstage and great extension, always smooth and delicate, never harsh. And usually only $12 unused


----------



## coastal1

Good to hear, I bought a pair of these. It sounded really bad at first so I switched it and haven't had time to burn it in yet. The eBay seller did include a note stating this but good to hear from someone neutral 



ohcrapgorillas said:


> IMO the RCA clear top is a fantastic 12AU7 replacement for the HD650. It sucks during burn-in but once it gets going, it opens up the top end and sounds really natural, good soundstage and great extension, always smooth and delicate, never harsh. And usually only $12 unused


----------



## coastal1

I bought a used BH Crack + Speedball and during shipping the solder joint of the red wire to the RCA center pin broke loose.  Seemed like an easy fix but I don't have a solder kit (or experience soldering). I had a good electrician at my house last week for a house issue and  I told him about the Crack and (thought) I carefully explained what needed to be done, even showed him the applicable pages of the manual. He said it would be an easy fix and offered to do it for no extra charge.
  
 Turns out he basically crimped the wire around RCA jack and soldered it to that rather than into the center pin.  He admitted it didn't look pretty, but said it will work.
  
 It does seem to work, in fact it sounds great (though I never heard the Crack in previous form so don't have that comparison), but I'm well aware this isn't how it's supposed to be connected.  A couple of questions: 
  
 (1) What specific problems could this incorrect connection cause?  There's no channel imbalance, no distortion, etc.  I have no intentions of selling it so not worried about the cosmetics.
  
 (2) I do have to turn to volume up more than I would've expected to fully drive my HD650s-- with 0 volume at 7 O'Clock, I turn it up to ~ 3 O'Clock to get them as loud as I'd possibly want them, again no distortion or any sound issues.  Using Jriver (PC vol at 100%) and IfI Micro as DAC, TS 5998 and Telefunk 12a7 tubes.  Is this normal to have to turn the volume so high and if not could it be from the rca connection?  Im happy to try different tubes to see if the volume is tube related, but wondering if I should get this fixed properly before using it more.
  
 (3) If I do need to have it fixed properly, does this significantly complicate a proper fix?  Ill be using someone experienced w/ HP amps and hopefully the Crack if I need to get it fixed right.


----------



## JamieMcC

coastal1 said:


> I bought a used BH Crack + Speedball and during shipping the solder joint of the red wire to the RCA center pin broke loose.  Seemed like an easy fix but I don't have a solder kit (or experience soldering). I had a good electrician at my house last week for a house issue and  I told him about the Crack and (thought) I carefully explained what needed to be done, even showed him the applicable pages of the manual. He said it would be an easy fix and offered to do it for no extra charge.
> 
> Turns out he basically crimped the wire around RCA jack and soldered it to that rather than into the center pin.  He admitted it didn't look pretty, but said it will work.
> 
> ...


 

 Can you post a pic? Having to turn the volume up so far sounds a bit odd


----------



## coastal1

jamiemcc said:


> Can you post a pic? Having to turn the volume up so far sounds a bit odd


 
  
 I posted this on the BH forum as well and added pics.  http://bottlehead.com/smf/index.php?topic=8024.0
 Someone posted that their Dale attentuator has to be turned up pretty both on the Crack and another amp so I may be all set.  Please let me know if you think differently.  As mentioned, I'm not having any SQ issues, just a couple things that seemed a little odd so was wondering if I needed to fix anything before really using the amp.


----------



## grausch

coastal1 said:


> I posted this on the BH forum as well and added pics.  http://bottlehead.com/smf/index.php?topic=8024.0
> Someone posted that their Dale attentuator has to be turned up pretty both on the Crack and another amp so I may be all set.  Please let me know if you think differently.  As mentioned, I'm not having any SQ issues, just a couple things that seemed a little odd so was wondering if I needed to fix anything before really using the amp.


 
  
 It really depends on the output level of your source. Seems that there is quite a lot of variance between different models / manufactures due to the "loudness wars".
  
 Unless you need to turn it up to the point where distortion gets introduced, no need to worry about this.


----------



## coastal1

grausch said:


> It really depends on the output level of your source. Seems that there is quite a lot of variance between different models / manufactures due to the "loudness wars".
> 
> Unless you need to turn it up to the point where distortion gets introduced, no need to worry about this.


 
  
 Thanks, will just go with it.  One of the odd things is that when used as a DAC/amp, my iFi Micro produces more volume (though not fidelity) even in "Normal" mode from the same computer/files.  I would've expected the Crack to produce more volume, but maybe it is just the way the Dale stepped attentuator works.  In any event, no issues with the SQ so I should be good


----------



## JamesBr

heliosphann said:


> Joined the club!!! Thanks to a fellow Head-Fi'er I now own a BHC w/Speedball. Listened to it for a while with my 650 and was utterly blown away.
> 
> 
> 
> ...


 
 Jalouse  I want to join the club!


----------



## Xeian

I bought a Crack with speedball from a trusted builder...
 ODAC
 Sennheiser HD-650
 Tung Sol 5998
 Genalex Gold Lion ECC82
 Cardas microtwin interconnect 300b
  
  
 Oh my lord... the sound stage. I just listened to the whole discography of RadioHead in FLAC. Mindblown.
 Its warm, but detailed. The unit seem to heat (not a lot, but still!)
 I love this thing.
 I will try to read more on it and add a custom VU Meter in the wood chassis.
  
 I upgraded from O2ODAC, i sent it back to have RCA output on it so i can use only the DAC from the unit. (from JDS LABS)
  
 Here is a "meh" picture of my setup :
  
http://i.imgur.com/gWgYYax.jpg
  
 Will try to run different tubes and give my impressions! (Maybe a RCA 12AU7 clear top?)
  
 First impression i feel that the mids are a bit laid back. But i dont know yet.
  
 100% satisfied with my purchase.
  
 Il get a couples more tubes, but i feel those two are solid quality from what iv read so far here.
  
 Time to download FLAC music and enjoy!


----------



## ohcrapgorillas

xeian said:


> I bought a Crack with speedball from a trusted builder...
> ODAC
> Sennheiser HD-650
> Tung Sol 5998
> ...




IMO the clear top is the way to go with the HD650, unless you can afford an Amperex 12AU7. The clear top and HD650 combo was almost solid enough for me to keep the HD650 but I'm an HD600 person at heart. The Gold Lion is solid for sure, but for me it does better with the HD600. But hey, everyone is different! And yeah, if you see an amperex tube for a good price, grab it!!


----------



## heliosphann

ohcrapgorillas said:


> IMO the clear top is the way to go with the HD650, unless you can afford an Amperex 12AU7. The clear top and HD650 combo was almost solid enough for me to keep the HD650 but I'm an HD600 person at heart. The Gold Lion is solid for sure, but for me it does better with the HD600. But hey, everyone is different! And yeah, if you see an amperex tube for a good price, grab it!!


 
 Is there a specific Amperex 12AU7 tube that's really good? I see a very large range of prices on e-bay.


----------



## johnnypaddock

This is probably a dumb question, but do you need to be playing music through the amp in order to burn in tubes, or can you just turn the power on? I recently bought an RCA clear top for my Crack/Speedball and was underwhelmed... listening through HD-600's. I'd like to see how they sound after proper burn in.


----------



## Allanmarcus

johnnypaddock said:


> This is probably a dumb question, but do you need to be playing music through the amp in order to burn in tubes, or can you just turn the power on? I recently bought an RCA clear top for my Crack/Speedball and was underwhelmed... listening through HD-600's. I'd like to see how they sound after proper burn in.


 
  
  
 Often you need to listen to the music since the "burn-in" is often just getting used to the new sound.
  
 Alternatively, leave it on for a day, but don't play anything, then listen to it. If it sounds better, then either the sound changed or your expectations were lowered sufficiently (yet another form of burn in).
  
 Then, if leaving it on for a day didn't make it sound better, play music through it without any headphone plugged in for a day, then check again. Use a low volume
  
 If that doesn't work, play music through it for a day with headphones plugged in, then listen again. If that doesn't change the sound it's possible you need to buy a new headphone cable, or a new power cable, or upgrade the caps, or upgrade the jacks, or update the resistors, or upgrade the wire, or upgrade the sockets. You may have a vibration issue, so you should put anti-vibration pads under your crack, under your source, and under the CD for one hour before you insert the CD into the CD player (to remove any pre-vibrations that might carry over). If you are playing music you downloaded, make sure the music has to to "rest" and become acclimated to your hard drive. If not acclimated, the music could get upset and sound jittery. Really. Google jitter and you will find all sort of discussion on jitter and how to avoid it.


----------



## johnnypaddock

allanmarcus said:


> Often you need to listen to the music since the "burn-in" is often just getting used to the new sound.
> 
> Alternatively, leave it on for a day, but don't play anything, then listen to it. If it sounds better, then either the sound changed or your expectations were lowered sufficiently (yet another form of burn in).
> 
> ...





Hahaha, thanks. Great post.


----------



## abhishekSPS

heliosphann said:


> ohcrapgorillas said:
> 
> 
> > IMO the clear top is the way to go with the HD650, unless you can afford an Amperex 12AU7. The clear top and HD650 combo was almost solid enough for me to keep the HD650 but I'm an HD600 person at heart. The Gold Lion is solid for sure, but for me it does better with the HD600. But hey, everyone is different! And yeah, if you see an amperex tube for a good price, grab it!!
> ...


 

 i would also like to know the ans....


----------



## hdtv00

Orange globe pretty much any would do though long as its 12au7 type. You could try and search for sale forum here too I've seen them listed before not sure if there are any left though hehe.
  
 http://www.ebay.com/itm/Vintage-Amperex-globe-12AU7-ECC82-grey-plate-top-halo-get-made-in-Holland-tested-/261930226607?pt=LH_DefaultDomain_0&hash=item3cfc4213af
  
 http://www.ebay.com/itm/AMPEREX-12AU7-ECC82-VACUUM-TUBE-ORANGE-GLOBE-1970-SINGLE-WARM-SWEET-A17F-/221798902742?pt=LH_DefaultDomain_0&hash=item33a43eabd6
  
 http://www.ebay.com/itm/Pair-2-Vintage-AMPEREX-12AU7A-Tubes-Hickok-533A-Tested-NOS-/381276023422?pt=LH_DefaultDomain_0&hash=item58c5d26a7e
  
 and this is cheapest best option probably, I should probably buy it myself because of the price alone but since I have a couple already and you're in need.
 http://www.ebay.com/itm/Strong-Amperex-World-Logo-by-GE-Short-Gray-Plate-O-Getter-12AU7A-ECC82-Tube-/111669932803?pt=LH_DefaultDomain_0&hash=item1a000bf303


----------



## Mich4lle

What ab





hdtv00 said:


> Orange globe pretty much any would do though long as its 12au7 type. You could try and search for sale forum here too I've seen them listed before not sure if there are any left though hehe.
> 
> http://www.ebay.com/itm/Vintage-Amperex-globe-12AU7-ECC82-grey-plate-top-halo-get-made-in-Holland-tested-/261930226607?pt=LH_DefaultDomain_0&hash=item3cfc4213af
> 
> ...



What about the bugle boy. As far as I know that is the best varient of the Amperex 12AU7 (and the most expensive) but that is for the HD 650 the best option, as far as I've heard. They can be found for around $70 for a good one.


----------



## hdtv00

Yea that ones ok but I much prefer the Orange Globe it give so much more life to upper range. Orange Globes are just as well respected as a Bugle Boy if you ask me, from what I've read on here. And for $11.00 ....seriously you guys will be kicking yourselves in the ass later for not grabbing it at that price. The guy is giving it away. Even the $20 are dirt cheap they are also Halo getters which I think are the better sounding version of the tube. Least most of the ones I linked are halo getters anyway it's real late and I can't remember but anyway.


----------



## Xeian

Thanks for the tip hdtv00! i bought that frst one you posted.
 Il rotate through Genalex Gold lion ECC82, RCA 12AU7 Cleartop and the Amperex 12AU7 Orange and give my impressions with my setup!
 Cheers


----------



## JamieMcC

I don't see the E80cc mentioned much of late its one of my favourite tubes for the Crack its also a long life tube 10000hr +


----------



## hdtv00

The way tube prices can be any time you see a tube that's decent for $10 -$20 buy it. Long as it looks right, seller is rated good. Because prices only go up, way up from there usually so, grab em while you can and at those prices.


----------



## Jeb Listens

It's good to be a bit cautious about choosing tubes based on their logos or them being "Orange Globe" or "Bugle-Boy" alone.  Tubes were re-branded all-over the place.  People get most excited about those 12AU7s that came out of the Philips factory in Holland since they have that characteristic warm yet detailed sound.
  
 Since Philips group was making tubes for Amperex and they have factories and subsidiary companies all over the world they might have come from anywhere in Europe or even further afield.  Also I'm not certain but one of those tubes looks like it could be a rebranded GE 12AU7 and another could be a rebranded Mullard.  I've seen some that were made in Japan. I have no idea if they sound alike but I would expect some differences.  
  
 Don't mean to throw a spanner in the works but its good to get into the habit of checking the factory-codes or asking the seller if you are looking for a particular tube. 
  
  
 Below - German branded VALVO ECC82s but made in Holland by Philips.
  

  
 Jeb.


----------



## hdtv00

Yea never buy from someone from ebay you refuses returns. Although really ebay pretty much supports the buyer and forces them to take them back anyway if they're not good working tubes. Even is mistaken labeled. But sound advice labeling actually works both ways. I've got some off labeled for a steal because they didn't know what they actually had.
  
 I comb through the tube roller threads here and on bottlehead forums, cause people like to post pics of their tubes. That way you can get an idea what construction was like on the tube you're looking for, it can be a guessing game and it sucks but also it's part of the fun finding a gem. And at $10 one can't go to wrong for the most part. But anyway yea good advice.


----------



## ohcrapgorillas

My Amperex is a rebranded Hewlett Packard tube, says "Made in Holland" and "by Amperex" on it. Sounds absolutely beautiful with the HD600.
  
 The RCA Clear Top was by far my favorite with the HD650 though...


----------



## NightFlight

allanmarcus said:


> Often you need to listen to the music since the "burn-in" is often just getting used to the new sound.
> 
> Alternatively, leave it on for a day, but don't play anything, then listen to it. If it sounds better, then either the sound changed or your expectations were lowered sufficiently (yet another form of burn in).
> 
> ...


 
  
  
 I'd come back and state that once your ear is sufficiently refined/trained, burn-in or break-in may make difference for you. Audiophiles generally don't listen to music the same way or for the same reasons that common folk do. They perhaps cue into dynamics, space, tone and timbre. Spacial queues, a sense of height width and depth with headphones especially require a system with a clean power supply and components. Audiophile grade components exists because every component in the signal chain or that imparts control of the signal will affect it by adding its own characteristic noise, or blurring if you will.  My mental view is to use the water analogy.  Rivers, rocks, pressure and time. The path of least resistance is made. This established path is generally audible and can be contrasted against identical equipment that is not 'burned-in'.  Its not a new concept and generally accepted as subjective evidence since the beginning of high-end audio.
  
  
 Admittedly there are extremists who will wave any voodoo over their equipment they can to try and 'purify' the sound. Generally this stems from ignorance and audiophools can be a odd bunch of subjectivists. But.. their not hurting anyone.  Just maybe the wallet.


----------



## Valhallatier

Hey guys is it ok if i run the crack with a low impedance and sensitive headphone? cause i found out my AD2000x is quite good through the crack but im scared at the same time if it will kill any equipment.


----------



## Keithpgdrb

It won't hurt your equipment.  it just wasn't designed to work well with them.  BUT, if you like it, thats all that matters man.  enjoy the music.


----------



## rogerthatmand

Hey guys,
 I have the HD800 and I ordered the Crack + Speedball two weeks ago, and while I'm waiting for it to be shipped, I'm starting to have some doubts about the purchase - maybe I should have gone with the Valhalla 2 instead.
 What do you think?


----------



## Koolpep

valhallatier said:


> Hey guys is it ok if i run the crack with a low impedance and sensitive headphone? cause i found out my AD2000x is quite good through the crack but im scared at the same time if it will kill any equipment.


 

 Hi!
  
 I always try my headphones on the Crack as well. Even the low impedance ones. No harm can happen to them. However, it can sound like poop. Example: Planars - sound terrible on the Crack. However, some lower impedance headphones like the K7XX sound surprisingly good on the crack. It all depends....
  
 But for sure the crack is not the ideal companion with anything below 150 Ohm in general. 


keithpgdrb said:


> It won't hurt your equipment.  it just wasn't designed to work well with them.  BUT, if you like it, thats all that matters man.  enjoy the music.


 
  
 This!! +1


----------



## skeptic

rogerthatmand said:


> Hey guys,
> I have the HD800 and I ordered the Crack + Speedball two weeks ago, and while I'm waiting for it to be shipped, I'm starting to have some doubts about the purchase - maybe I should have gone with the Valhalla 2 instead.
> What do you think?


 
  
 Welcome to the crack thread roger!  Happy to pick up the discussion of the pairing with the hd800's here.
  
 With respect to the val 2 vs. crack, although both are OTL tube amps, these amps have evolved from very different design philosophies.  Specifically, val 2 uses negative feedback to lower its output impedance, reduce distortion and cater to a wider range of headphones - the exact same way many discrete solid state and all opamp based amps (like your o2) do.  
  
 Bottlehead, by contrast, is committed to non-feedback topologies, which may have slightly higher overall THD and output impedance, but are free of certain complex non-linear distortions, transient intermodulation distortions and disproportionate high order distortions produced by feedback amps.  Different ears prefer different things in this regard, but knowledgeable amp designers generally agree that the distortion products of non-feedback amps are much closer to the natural harmonics produced by acoustic instruments and consequently less grating to many listeners than the non-linear distortions of feedback amps.  Nelson Pass, who makes both sorts of amps, has a very nice explanation of these considerations here: https://passlabs.com/articles/audio-distortion-and-feedback   
  
 Since you already have a feedback amp, I'd urge you to stay the coarse with the crack.  If nothing else, building it will be a great experience and provide you with more audio understanding than the vast majority of the "unwashed masses" on HF.  It is a good budget pairing with hd800's to my ears, even if it is bettered by the mainline and certain other high end amps.  Ears that I trust say val 2 is also a good budget pairing for hd800's that rivals a crack, but honestly, if I were contemplating a crack alternative, I would lean towards building a torpedo (budget parafeed amp designed by Doug of ECP) before buying a val 2.


----------



## rogerthatmand

Fantastic answer skeptic. Thank you very much!
 Makes me really confident about the Crack purchase.


----------



## JamieMcC

valhallatier said:


> Hey guys is it ok if i run the crack with a low impedance and sensitive headphone? cause i found out my AD2000x is quite good through the crack but im scared at the same time if it will kill any equipment.


 
  
 There are a couple of alternative driver tubes that can be used in the Crack that will lower the Cracks output impedance which can help sonically if running lower Z cans the Tungsol 5998 is probably the most common one. I seem to recall it roughly halves the Cracks output perhaps someone might have the correct figures saved. I ran some 42ohm ATH W1000X for a while and they sounded much better running the 5998 compared to a 6080 or 6as7g particularly the mid bass and lower regions which seem to be those most effected.
  
  Perhaps it was one of the Tungsol/Bendix  6080 equivalents  as well but honestly cannot remember what its code number was.


----------



## ohcrapgorillas

I'm just gonna chime in here and say that my 32 ohm Grados do awesome with the Crack. Personally I love it especially with the stock 6080 tube (for its gooey, warm, bassy sound) and an RCA clear top (to keep the treble is delicate and smooth).
  
 Someone correct me if I'm wrong here, but for mismatched impedance, it's the bass that suffers the most, right? And in the case of the SR80i, the bass was never anything to write home about to begin with.


----------



## Maxhawk

For drop-in replacement, I'll put in my vote for the CBS-Hytron 5814 black plate with angled getter. I like it better than the various 12AU7 variants, although I haven't tried Amperex or Mullard.


----------



## FunyunBreath

What I've noticed the most when plugging in low impedance phones with the Crack is that at a certain volume level the sound begins to distort alot. I've plugged in dt770's, HE-400's, DT 880's, and Sony MDR-7520 and they all had the same issue at louder volumes.


----------



## skeptic

funyunbreath said:


> What I've noticed the most when plugging in low impedance phones with the Crack is that at a certain volume level the sound begins to distort alot. I've plugged in dt770's, HE-400's, DT 880's, and Sony MDR-7520 and they all had the same issue at louder volumes.


 
  
 Do you have the 32 ohm versions of the dt770's and dt880's?  The standard versions of these are 250 ohm, and I can confirm that my crack sounds great with 250 ohm dt880's and does not distort at high volume.  Have been running this combo all day today in the office.
  
 My experience running low ohm phones out of the crack (some audio technica's, just for giggles), was that they sounded really anemic compared to when they are properly amped, with poorly damped bass.  For me, one song was totally adequate confirmation of bottlehead's disclaimer that crack was intended for high ohm phones, and I went right back to my hd650's and dt880's.


----------



## FunyunBreath

skeptic said:


> Do you have the 32 ohm versions of the dt770's and dt880's?  The standard versions of these are 250 ohm, and I can confirm that my crack sounds great with 250 ohm dt880's and does not distort at high volume.  Have been running this combo all day today in the office.
> 
> My experience running low ohm phones out of the crack (some audio technica's, just for giggles), was that they sounded really anemic compared to when they are properly amped, with poorly damped bass.  For me, one song was totally adequate confirmation of bottlehead's disclaimer that crack was intended for high ohm phones, and I went right back to my hd650's and dt880's.




Yeah the 32 ohm versions, the 250 and 600 ohm beyers sound great on the Crack.


----------



## NightFlight

valhallatier said:


> Hey guys is it ok if i run the crack with a low impedance and sensitive headphone? cause i found out my AD2000x is quite good through the crack but im scared at the same time if it will kill any equipment.


 
  
 What you'll find is that after a while when the high wears off.... your low impedance headphones don't sound as clean as high impedance headphones do. A year or two may go by and then you realize perhaps a directly couple pre to output section are perhaps a bit too close for comfort.
  
 LOL. Anyhow... Buy the ticket. Enjoy the ride.


----------



## NightFlight

rogerthatmand said:


> Hey guys,
> I have the HD800 and I ordered the Crack + Speedball two weeks ago, and while I'm waiting for it to be shipped, I'm starting to have some doubts about the purchase - maybe I should have gone with the Valhalla 2 instead.
> What do you think?


 
  
 I think you can tweak the Crack to your tastes and learn something in the process. That's what I think.


----------



## coastal1

If I switch my headphones to balanced cables for another amp, will the balanced headphones with an XLR to 1/4" cable work fine with the Crack, or is there any reason I'd need to switch back to the original SE cable when using the Crack?


----------



## skeptic

coastal1 said:


> If I switch my headphones to balanced cables for another amp, will the balanced headphones with an XLR to 1/4" cable work fine with the Crack, or is there any reason I'd need to switch back to the original SE cable when using the Crack?


 
  
 An adapter will work just fine and is cheap and easy to make with a couple of neutrik plugs.  
  
 The typical wiring configuration for a 4 pin XLR is:
  
*Pin 1 - L+*
*Pin 2 - L-
 Pin 3 - R+
 Pin 4 - R-*
  
 So at the other end, pin 2 and 4 should be connected to the sleeve (signal ground) of the TRS, pin 1 the tip (left channel), and pin 3 the ring (right channel).


----------



## HiGHFLYiN9

skeptic said:


> Bottlehead, by contrast, is committed to non-feedback topologies, which may have slightly higher overall THD and output impedance, but are free of certain complex non-linear distortions, transient intermodulation distortions and disproportionate high order distortions produced by feedback amps.  Different ears prefer different things in this regard, but knowledgeable amp designers generally agree that the distortion products of non-feedback amps are much closer to the natural harmonics produced by acoustic instruments and consequently less grating to many listeners than the non-linear distortions of feedback amps.  Nelson Pass, who makes both sorts of amps, has a very nice explanation of these considerations here: https://passlabs.com/articles/audio-distortion-and-feedback
> 
> Since you already have a feedback amp, I'd urge you to stay the coarse with the crack.  If nothing else, building it will be a great experience and provide you with more audio understanding than the vast majority of the "unwashed masses" on HF.  It is a good budget pairing with hd800's to my ears, even if it is bettered by the mainline and certain other high end amps.  Ears that I trust say val 2 is also a good budget pairing for hd800's that rivals a crack, but honestly, if I were contemplating a crack alternative, I would lean towards building a torpedo (budget parafeed amp designed by Doug of ECP) before buying a val 2.


 
  
 Excellent post and the linked article by Pass is a great read. The Crack w/Speedball and the ECP/Beezar Torpedo are the best value tube headphone amplifiers I've personally heard. I personally like my Crack better with higher impedance cans like my DT990 600ohm and modified Darth Beyers, but that's with copious tweaking and part changes. As stated, the Edcor output xformers make the Torpedo a better candidate for Grados, Denons, etc. Also don't forget about the S.E.X., output transformers and adjustable impedance switching, that's a great jack-of-all trades amp with a slightly lush sound. I love mine.


----------



## DDDamian

highflyin9 said:


> Excellent post and the linked article by Pass is a great read. The Crack w/Speedball and the ECP/Beezar Torpedo are the best value tube headphone amplifiers I've personally heard. I personally like my Crack better with higher impedance cans like my DT990 600ohm and modified Darth Beyers, but that's with copious tweaking and part changes. As stated, the Edcor output xformers make the Torpedo a better candidate for Grados, Denons, etc. Also don't forget about the S.E.X., output transformers and adjustable impedance switching, that's a great jack-of-all trades amp with a slightly lush sound. I love mine.


 
 +1 - have both BH amps and love 'em both (for different cans and different reasons).


----------



## rogerthatmand

Someone here ever done a comparison with the Trafomatic Experience Head One?


----------



## ph0ngt3p

Hi guys, just wondering if the Bottlehead Power Cord works at 220v/50hz ? I'm looking to buy it but not sure if it could work in my country.


----------



## Koolpep

ph0ngt3p said:


> Hi guys, just wondering if the Bottlehead Power Cord works at 220v/50hz ? I'm looking to buy it but not sure if it could work in my country.




The power cord doesnt care for the voltage. But your crack does. If you have a 110V version under no circumstances shoukd you connect it to 220V.

Cheers,
K


----------



## ph0ngt3p

koolpep said:


> The power cord doesnt care for the voltage. But your crack does. If you have a 110V version under no circumstances shoukd you connect it to 220V.
> 
> Cheers,
> K


 
 Thanks. So the cord will work anywhere, it's just the plug that's made for the 120VAC mains in US, right ?


----------



## JamieMcC

I would check on the bottlehead forum to find out the voltage rating of the wire they use it looks the same as in the crack from the pictures on the forum.
  
 For a UK availiable option you will find the belden 19364 cable has long been a very popular choice for diy power cable builders MCRU do a number of power lead kits which I use for my Bottlehead amps.  They do some differing length options but here is a link to the one I am using.
  
http://www.ebay.co.uk/itm/150963875838?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT


----------



## Aeolus Kratos

Hi guys,
 I bought my Crack along with a Tung-sol 5998 last year. Unfortunately, my 5998 got some microphonics ("ting ting" sound) as I typed or touched the Crack and I didn't have a decent DAC/source back then, so I couldn't have any critical judgement on the sound of Tung-sol 5998. Then I was fortunate and bought a Bendix 6080WB slotted graphite plate power tube and the Bendix was totally dead silent. I sold my 5998 right after that (just because of the microphonics).
  
 Time goes by, I've upgraded the DAC/source and my cable and still been using the Bendix since I first bought it. I'm very happy with the Bendix, but the curiosity has grown up in me and the fact that the 5998s have got excellent feedback really make me want to try a Tung-sol 5998 again.
  
 But the thing is, in my country, there are not many audiophiles so I can't sell either the Bendix and 5998 easily if I don't like them. And my budget can only allow me to keep one premium power tube for my Crack, if I order a 5998, I have to sell my Bendix, not to mention it'll take a decent time. So I have to think and choose carefully.
  
 Has anyone had a chance to own both the 5998 and the Bendix and could directly compare or had a A/B testing them? If so, how would you compare the two tubes?
  
 I'm using HD650, but planning to get a HD800 in the near future. My DAC is NAD M51, fed by Audio GD DI-2014. My favorite genres are mainly vocals, jazz, instrumental and country (slow music), I hardly listen to strong or fast music.
  
 Sorry for any grammar mistakes or misleading. English is not my native language and I'm not so good at English so I just tried my best to describe my situation.
  
 Thank you very much. I'm really looking forward to your feedback. All the helps will be greatly appreciated.
  
 Cheers,
 Kratos.


----------



## moriez

@Aeolus Kratos, I recently swapped my ting tingy, actually squeally 5998 out for a new one. If you're in Europe we can try getting my unused tube to you so you can try it out yourself for comparison. No strings attached.
  
 PM me if you're interested.


----------



## DDDamian

My beloved 5998 has developed a few issues of late as well. That said, quite enjoying my bottom-getter Winged-C. Doesn't have quite the detail of the 5998 - a bit warmer too, but a very nice sound. Quite musical. FWIW I found the Bendix a little too warm for my liking, but for those who crave tubiness it was quite nice. Really smoothed sax and lesser recordings.
  
 Nice offer there moriez, good on ya


----------



## Whit3Rav3n

I built the Bottlehead Crack a few weeks ago. For the first tests I only had the Sennheiser HD 800 available. in my opinion the crack without the speedball upgrade is not a good combination with the HD 800. It lost way too much precision and detail. Especially the treble was lacking too much. The sound was still good but more on the level of cheaper headphones. The speedball upgrade was quite a big improvement. The amp became faster and more detailed. I am using an op amp modded Asus Xonar One as DAC and the built in amp as comparison. Compared to the Asus amp the Bottlehead is more bass and mid focused, it has a warmer and fuller sound. The soundstage and detail are still better on the Asus amp. Right now there is no clear winner between the two, it comes down to preference.
  
 Is someone using the crack with the HD 800 and has some good tube combinations for more soundstage and detail? As far as I have seen a good upgrade would be getting the 5998 but they are pretty hard to get and quite expensive.


----------



## moriez

^ Same offer for you Whit3Rav3n. Because.. why not? First come, first served.


----------



## DDDamian

moriez said:


> ^ Same offer for you Whit3Rav3n. Because.. why not? First come, first served.


 
 A very generous offer Whit3Rav3n. The 5998 has a lot of detail. Try seek out a CIFTE (Mazda) 12AU7 to pair it with. My favourite combo so far for detail and a livelier sound. Some of the stock 6080's are a little warm/dull.


----------



## adydula

Just finished my Crack after 7 hours of DIY fun...it was a real easy kit and I highly recommend it to anyone wanting to try a venture into the DIY area.
  
 All resistances and voltages were spot on....
  
 Fired it up from Flacs on a pc to an ODAC .....with my Beyer DT90s.
  
 Result: Marriage made in heaven....absoultely superb with these 250 ohm cans.
  
 Very musical and details and soundstage!!
  
 I have a speedball kit but am thinking of just enjoying it the way it is!!! Its that good!.
  
 All the best
 Alex


----------



## Loquah

No doubt it's good now (and congrats on the successful build), but do yourself a favour and install the Speedball when you're ready - you won't regret it!


----------



## adydula

Yup, I got the $20 offering the other day, just waiting on it to be shipped etc....
  
 I cant believe how good this simple amp is with the DT90's....just really awesome sound-stage and depth/detail....wow,
  
 I wish I knew what the actual tubes are, sent BH a note asking them etc..
  
 Just have to finish the case, its glued and drying...
  
 Alex


----------



## Loquah

Perhaps post some pics here too. No doubt some of the tube gurus will know.


----------



## adydula

Ok I will take some tomorrow the larger tube the power 6080 type is a really old RCA large bottle looking type and its looks really cool
  
 I am 66yrs old now and grew up with these valves! Ha!!
  
 I have built some really complex tube projects over the years, this one is so simple it makes me laugh.....
  
 Alex


----------



## DDDamian

I'm amazed when I peer into the innards of my SS amp and see the sheer number of parts. Then I flip the top of the Crack and say "Wow - all that sound out of this??"


----------



## Aeolus Kratos

moriez said:


> @Aeolus Kratos, I recently swapped my ting tingy, actually squeally 5998 out for a new one. If you're in Europe we can try getting my unused tube to you so you can try it out yourself for comparison. No strings attached.
> 
> PM me if you're interested.


 

 Hi Moriez,
  
 Sorry for replying this late, I'd been traveling for business last week, just came back today.
  
 That's very kind of you. I would love to take your offer. Unfortunately, I'm not in Europe, so shipping the 5998 back and forth to my country may take a long time and high cost too.
  
 Warm regards,
 Kratos.


----------



## moriez

You're welcome and no worries. All is well that ends well. WhiteRaven lives relatively close to me so we have ideal circumstances. Maybe someone else is willing to give you a peek.


----------



## adydula

I found a small hardly perceivable 12AU7 on my signal tube in the crack....but no symbol or marking for a particular manufacturer.
  
 The larger tube has nothing I can discern here are some pix if anyone thinks they know what it might be:
  

  

  

  

  

  


  

  

  
 Will work on finishing up the case this week.
  
 Alex


----------



## Whit3Rav3n

dddamian said:


> A very generous offer Whit3Rav3n. The 5998 has a lot of detail. Try seek out a CIFTE (Mazda) 12AU7 to pair it with. My favourite combo so far for detail and a livelier sound. Some of the stock 6080's are a little warm/dull.


 
 Thanks for the tip, maybe I will first try to get an rca clear top tube, they seem to be considered pretty good and they are cheap. The Mazda 12AU7 tubes seem to be hard to get and pretty expensive. Moriez was generous enough to lend me his 5998 so I will be able to test it out and see how it compares to the original tube.


----------



## FunyunBreath

Just scored a vintage NAD 3020 to go along with my Crack as a solid-state option. The sound signature on this thing is unbelievably close to the Crack, but it seems to do really well with 32 ohm headphones and even 16 ohm IEM's.
  
 Picked this thing up on Craigslist for $75 and after a little clean up and Deoxit on the switches/pot it sounds good as new!


----------



## adydula

Bottlehead guys told me it is a 6AS7G.....great!
  
 Alex


----------



## DDDamian

whit3rav3n said:


> Thanks for the tip, maybe I will first try to get an rca clear top tube, they seem to be considered pretty good and they are cheap. The Mazda 12AU7 tubes seem to be hard to get and pretty expensive. Moriez was generous enough to lend me his 5998 so I will be able to test it out and see how it compares to the original tube.


 
 The clear-tops are well-regarded and much easier to obtain. I'd warn against Mullards if you're finding things a touch dull - they and the ECC82 might be a bit too smooth for your output tube.
  
 Hope you like the 5998 - it's a beauty and clear, detailed and lively.


----------



## Whit3Rav3n

dddamian said:


> The clear-tops are well-regarded and much easier to obtain. I'd warn against Mullards if you're finding things a touch dull - they and the ECC82 might be a bit too smooth for your output tube.
> 
> Hope you like the 5998 - it's a beauty and clear, detailed and lively.


 
 Am I correct that this is the RCA clear top that is well regarded?
  
http://www.ebay.com/itm/RCA-12AU7-ECC82-CLEARTOP-VACUUM-TUBE-SINGLE-LOW-NOISE-SUPER-SWEET-WARM-TONE-R04k-/111605051737?pt=LH_DefaultDomain_0&hash=item19fc2df159
  
 As far as I have checked the RCA clear top sounds rather clean and bright so it might work well for me.


----------



## FunyunBreath

Yup thats the one, good price too


----------



## johnnypaddock

Great price on that, well worth picking one up. I think I paid $30 for one just a few months ago. It has a nice top end, but I find it slightly lacking in the midrange, kind of a lean sound.


----------



## Whit3Rav3n

Thanks, I ordered one and will see how it sounds. At least it was pretty cheap so it is not a big deal if it is not ideal.


----------



## FunyunBreath

I totally agree with that critique. I picked up a lot of 20 for crazy cheap on ebay and haven't really been using them much. I prefer the fuller mid-centric sound of the Amperex 12au7's.


----------



## johnnypaddock

I'd like to try the Amperex, as well as the Mullard CV4003. I'm currently using a CBS Hytron that seems to match very well.


----------



## FunyunBreath

Ha, ironically enough I got a tube in the mail a few hours ago that might unseat my Amperex as the reigning champion 
  
 Parts Connexion had a deal on Pearl cryo treated RCA 12au7's and I picked one up.... Holy cow this thing is excellent sounding! Mids galore, clarity, excellent bass and imaging:


----------



## DDDamian

Yeah for more mid-centric smooth vocals I enjoy the Tungsram ECC82. But for detail and sparkle those RCA clear-tops are hard to beat at the price. Hope you enjoy! Also, keep an eye out as sometimes bargains come along. Some prices are definitely on the premium side of reasonable, but occasionally a gem passes by.


----------



## DDDamian

funyunbreath said:


> Ha, ironically enough I got a tube in the mail a few hours ago that might unseat my Amperex as the reigning champion
> 
> Parts Connexion had a deal on Pearl cryo treated RCA 12au7's and I picked one up.... Holy cow this thing is excellent sounding! Mids galore, clarity, excellent bass and imaging:
> 
> ...


 
 That's a beaut - nice score.


----------



## White Lotus

Hey Crack owners and enthusiasts - great thread!
  
 Quick one for you guys - 
  
 I might have an opportunity to buy a pre-built Crack w/speedball for cheap.
  
 Should I do it?
  
 These are my primary-use cans:
  

Audeze LCD 2.2
Denon D5000
Grado SR80i
  
 It looks like none of those are well suited - at least on paper.
  
 Any thoughts?


----------



## hdtv00

Yea either way you can hook me up with one cheap. Define cheap lol


----------



## White Lotus

It's second hand.


----------



## Keithpgdrb

white lotus said:


> Hey Crack owners and enthusiasts - great thread!
> 
> Quick one for you guys -
> 
> ...


 
 I wouldnt if there are no high impedance cans in your future.  they wouldnt do very well with what you have listed.


----------



## hdtv00

Yea either way like I said. Define cheap, and someone would love to have one cheap. I'm trying to buy one for a wedding present for someone. But there are tons of people I'm sure on here.


----------



## rated1975

funyunbreath said:


> Ha, ironically enough I got a tube in the mail a few hours ago that might unseat my Amperex as the reigning champion
> 
> Parts Connexion had a deal on Pearl cryo treated RCA 12au7's and I picked one up.... Holy cow this thing is excellent sounding! Mids galore, clarity, excellent bass and imaging:



Great orange peel finish on the metal plate. How did you achieve this?


----------



## daltonljj

rated1975 said:


> Great orange peel finish on the metal plate. How did you achieve this?


 
 I may be wrong to how he got it. But you can try looking for paints that state hammered finish which looks jus like that. My crack was hammered gold finish.Currently rebuild my crack and decided to go with raw aluminium mirror finish


----------



## FunyunBreath

rated1975 said:


> Great orange peel finish on the metal plate. How did you achieve this?


 
  
 Yup! Hammered finish spraypaint.
  
 I used 2 coats of primer on the aluminum plate and bell first, then literally about 12-15 coats of black hammered spray paint. Give it 3 minutes in between coats and you get a nice textured finish without any nasty blotches.


----------



## rated1975

funyunbreath said:


> Yup! Hammered finish spraypaint.
> 
> I used 2 coats of primer on the aluminum plate and bell first, then literally about 12-15 coats of black hammered spray paint. Give it 3 minutes in between coats and you get a nice textured finish without any nasty blotches.



So just a few coats then 
Great work, looks superb. Nice pic also.


----------



## Doc B.

I've sprayed Hammerite on many of our panels over the years. Prep is everything, get the panel really clean with formula 409 or lacquer thinner before spraying. Hammer finish paint is a product that doesn't really require a primer, and I usually spray just a couple of mist coats and then one medium heavy coat a minute or two apart. A bunch of light coats will end up more textured than hammered. It's also very important to give it time to polymerize. I suggest waiting at least a week before mounting any hardware to avoid tearing the finish.


----------



## adydula

I just added the 4 extra resistors in the Crack FAQ on the BH site to allow for more rotation of the volume pot....2- 75K's and 2 - 33K's....works wonderfully!
  
 This is a really nice amp.....and I finally finished the 4th coat of Mission Oak Minwax and its really looking nice.....
  
 Alex


----------



## DDDamian

white lotus said:


> Hey Crack owners and enthusiasts - great thread!
> 
> Quick one for you guys -
> 
> ...


 
 Yes. S.E.X.


----------



## White Lotus

dddamian said:


> Yes. S.E.X.


 
  
 Yep, not really an option for me, as it's not the product being offered to me for cheap.
  
  I'll steer clear of this product, as it doesn't seem to suit my needs.
  
 Thanks for the advice, everyone! Much appreciated.


----------



## rated1975

doc b. said:


> I've sprayed Hammerite on many of our panels over the years. Prep is everything, get the panel really clean with formula 409 or lacquer thinner before spraying. Hammer finish paint is a product that doesn't really require a primer, and I usually spray just a couple of mist coats and then one medium heavy coat a minute or two apart. A bunch of light coats will end up more textured than hammered. It's also very important to give it time to polymerize. I suggest waiting at least a week before mounting any hardware to avoid tearing the finish.


 

 Thanks Doc. Now just a matter of choosing a colour and waiting for the Crack to arrive.


----------



## heliosphann

Just got some custom 600ohm DT990's. 
  
 What's a good input tube to bring the best out of these cans?


----------



## krazyxazn

I bought this about 2 months ago and just finished it yesterday. It was a highly enjoyable project from start to finish. I'm a beginner to this kind of stuff and even I did a decent job. I opt'd to forgo speedball install for a month to see if I'll notice the difference.
  
 Custom Work
 Stain: Rustoleum Kona
 Finish: Rustoleum Poly
 Top Plate: Almond Powder Coated ~$25
 Transformer Cap: Silver Powder Coated ~$12
  
*Full Photo Album (Imgur)*


----------



## adydula

Here's mine with 4 coats of Mission Oak Minwax:
  

  

  
 Alex


----------



## Doc B.

Nice work you guys! They are both lovely.


----------



## adydula

Thanks Doc! Its a pleasure to make your acquaintance.....
  
 Speedball is next when your elves ship it out.
  
 A very simple circuit that does exceptionally well!
  
 All the best.
  
 Alex


----------



## Aeolus Kratos

I just returned home after a long week traveling for work, turned on the beloved Crack, plugged the HD650 in and listened to all my sweet music....
  
 Oh man, I actually forgot how addictive the music coming from the Crack + HD650 combo can be. When I listen to my setup, I no longer care about how the bass, the treble is, the soundstage and other "technical" factors of the sound are produced, it's just me, lost in the music.
  
 Thanks Doc for such an amazing and magical music experience! It really helped me relax after a hard working day.
  
 Cheers,
 Kratos.


----------



## DDDamian

Nice testimonial  do you find the tube stabilizers / dampers make a difference?


----------



## coastal1

Need a little help.  I'm getting constant 'clicking' sounds from my amp that starts without anything plugged into the RCA jacks so it's not coming from interference from source.  At first I thought it might be a new input tube that hadn't burned in, but I tried a Telefunken that's sounded clean before and still got the clicking sounds.  Using TS 5998 as output tube, and that too has previously sounded great.  
  
 So I was thinking as first step I'll clean the tube pins and tube sockets, and then check all connections.  Cleaning the tube pins seems easy enough, but any advice about the best way to clean the sockets is appreciated, as well as the best contact cleaner to use. Also, the output tube 'wobbles' quite a bit more than the input tube.  Could this be a possible cause of the noise, i.e., not a tight enough connection?  The wobble is not new (sounded great before) so I'm a little reluctant to try to mess with that unless that's an obvious red flag.  I bought this used so not sure if the wobble is normal, or if the output socket needs to be tightened or replaced.
  
 Any other likely causes?
  
 Thanks in advance.


----------



## FunyunBreath

coastal1 said:


> Need a little help.  I'm getting constant 'clicking' sounds from my amp that starts without anything plugged into the RCA jacks so it's not coming from interference from source.  At first I thought it might be a new input tube that hadn't burned in, but I tried a Telefunken that's sounded clean before and still got the clicking sounds.  Using TS 5998 as output tube, and that too has previously sounded great.
> 
> So I was thinking as first step I'll clean the tube pins and tube sockets, and then check all connections.  Cleaning the tube pins seems easy enough, but any advice about the best way to clean the sockets is appreciated, as well as the best contact cleaner to use. Also, the output tube 'wobbles' quite a bit more than the input tube.  Could this be a possible cause of the noise, i.e., not a tight enough connection?  The wobble is not new (sounded great before) so I'm a little reluctant to try to mess with that unless that's an obvious red flag.  I bought this used so not sure if the wobble is normal, or if the output socket needs to be tightened or replaced.
> 
> ...


 
  
 If you take the amp to another room in the house do you still get the clicking? Wondering if it may be wireless interference from your phone or router.


----------



## coastal1

funyunbreath said:


> If you take the amp to another room in the house do you still get the clicking? Wondering if it may be wireless interference from your phone or router.


 
  
 Thanks, I actually should have mentioned this and will try this as a first step.  Along with trying a new input tube, I did move the amp to a room that has a router (and TV) nearby.  Those were the only changes.  The router is a couple of feet away, the TV is very close, though turned off.


----------



## FunyunBreath

Yeah my guess is it's the router for sure. My amp is in my office where my router is as well, but I moved the router all the way across the room to get it as far away from the amp as possible. Otherwise I get those popping/clicking noises too.
  
 You're pretty much going to hear any device that uses wifi/4G in vacuum tubes as a popping/clicking noise when data is being transmitted.


----------



## coastal1

funyunbreath said:


> Yeah my guess is it's the router for sure. My amp is in my office where my router is as well, but I moved the router all the way across the room to get it as far away from the amp as possible. Otherwise I get those popping/clicking noises too.
> 
> You're pretty much going to hear any device that uses wifi/4G in vacuum tubes as a popping/clicking noise when data is being transmitted.


 
  
 Great, thanks very much.  Hopefully this will resolve the issue and I'll save the socket cleaning/tightening project for another day... by the way, should the 'wobble' of the output tube be a concern at all?


----------



## Keithpgdrb

I was also going to suggest interference from outside the amp.  I was convinced that my amp was going south, until I moved my cell phone away from the amp.  so step one, make sure your phone is no where near the amp.  then check the router thing.  that should be easy to test.  even moving it a few feet away should change the interference if that is the cause.


----------



## FunyunBreath

coastal1 said:


> Great, thanks very much.  Hopefully this will resolve the issue and I'll save the socket cleaning/tightening project for another day... by the way, should the 'wobble' of the output tube be a concern at all?


 
  
 Is the entire socket wobbling (where it's mounted to the chassis) or just the tube pins inside the socket?


----------



## coastal1

funyunbreath said:


> Is the entire socket wobbling (where it's mounted to the chassis) or just the tube pins inside the socket?


 
 Not exactly sure, will check tonight.  I just noticed that the output tube wobbles whereas the input tube is quite stable.


----------



## coastal1

keithpgdrb said:


> I was also going to suggest interference from outside the amp.  I was convinced that my amp was going south, until I moved my cell phone away from the amp.  so step one, make sure your phone is no where near the amp.  then check the router thing.  that should be easy to test.  even moving it a few feet away should change the interference if that is the cause.


 
  
 Thanks, don't think it's my phone as I've streamed Tidal from it-> iFi Micro->Crack without issue (not my usual setup, just wanted to try it).  But the router or something else could definitely be the culprit


----------



## Valhallatier

guys, my crack died....? i need help. this is my first tube amp, so im quite noob with it.
 It was just fine when suddenly, when nothing was playing, theres a faint "skrsh skrsh" sound through my DT880, then i realized, the light on my tubes are gone, and there's no sound.
 what im worried is my amp dead, or should i be fine by replacing the tubes?

 EDIT: my amp works again after an hour. i have no idea what happened, any input guys? i thought the tubes died but no!


----------



## adydula

You could measure the heater voltage. do you know how to do this? If you built this Crack then it tells you how to check voltages. Did both tubes go out at the same time? Check the fuse as well.
  
 Alex


----------



## Whit3Rav3n

whit3rav3n said:


> I built the Bottlehead Crack a few weeks ago. For the first tests I only had the Sennheiser HD 800 available. in my opinion the crack without the speedball upgrade is not a good combination with the HD 800. It lost way too much precision and detail. Especially the treble was lacking too much. The sound was still good but more on the level of cheaper headphones. The speedball upgrade was quite a big improvement. The amp became faster and more detailed. I am using an op amp modded Asus Xonar One as DAC and the built in amp as comparison. Compared to the Asus amp the Bottlehead is more bass and mid focused, it has a warmer and fuller sound. The soundstage and detail are still better on the Asus amp. Right now there is no clear winner between the two, it comes down to preference.
> 
> Is someone using the crack with the HD 800 and has some good tube combinations for more soundstage and detail? As far as I have seen a good upgrade would be getting the 5998 but they are pretty hard to get and quite expensive.


 
 I made some improvements since the last post with the crack. The first thing I did I changed the interconnect cable. For the first tests I only had a very cheap interconnect cable available. Since then I built a better one with a nice looking Sommer Cable grindycop cable and Hic-on connectors. This improved soundstage and the treble quite a lot. I also recieved the Tung-Sol 5998 tube. This improved detail and treble even more. The bass is also more controlled with this tube. Now I starting to like the crack more than the built in headphone amp of the Asus Xonar One. I will probably upgrade the output capacitors to film capacitors as well. For the input tube the rca clear top shuld arrive in a few days so I will be able to test how that sounds in the crack.


----------



## coastal1

So the good news is that the router is the causing the interference. No interference from iPhone. Tubes don't seem to be an issue. The bad news is that we have wifi issues in our house so we have a router and booster in that room, and not only is there nowhere in that room that I can go without interference, but I still get interference in the next room over. No interference whatsoever in the bedroom, and my wife isn't entirely thrilled with having this beast permanently live in there.



funyunbreath said:


> If you take the amp to another room in the house do you still get the clicking? Wondering if it may be wireless interference from your phone or router.


----------



## FunyunBreath

Nice, good that you figured it out!
  
 You could always try a tube shield on the 12au7 and see if it blocks the interference, or it might just be time for a stronger router so you can ditch that booster


----------



## DDDamian

whit3rav3n said:


> I made some improvements since the last post with the crack. The first thing I did I changed the interconnect cable. For the first tests I only had a very cheap interconnect cable available. Since then I built a better one with a nice looking Sommer Cable grindycop cable and Hic-on connectors. This improved soundstage and the treble quite a lot. I also recieved the Tung-Sol 5998 tube. This improved detail and treble even more. The bass is also more controlled with this tube. Now I starting to like the crack more than the built in headphone amp of the Asus Xonar One. I will probably upgrade the output capacitors to film capacitors as well. For the input tube the rca clear top shuld arrive in a few days so I will be able to test how that sounds in the crack.


 
 Those are all good upgrades. The 5998 is a great tube, and the clear-tops are (for the price) a great driver tube. If they are NOS (new old stock) they may get a bit better over time too. If you do go upgrading caps then they also need to burn-in a bit - they can seem harsh and bass-shy at first in my limited experience. Give each change some time. It's a great amp.


----------



## coastal1

funyunbreath said:


> Nice, good that you figured it out!
> 
> You could always try a tube shield on the 12au7 and see if it blocks the interference, or it might just be time for a stronger router so you can ditch that booster


 
  
 Thanks for all the help.  There's weird wifi and cell issues in my neighborhood, especially for being in a populated area.  We've had 10+ at&t techs come out to improve our service and this is what theyve come up with so far.  At least the equipment theyve given us is free...
  
 I switched power strips (nothing fancy) and am at least able to have no interference in the next room over.  Have a couple more lying around and will see if I can get something that blocks interference the media room.  Thanks for the rec on a tube shield as well


----------



## adydula

I have a 6AS7G tube that has a very low noise, whistle etc that if I gently tap on the tube will go away for several minutes and sometimes for hours, but when first using it I go thru the process of letting it warm up and then after 30 minutes or so the small buzz is there in the background...not that annoying when listening except with low passages of music u hear it and of course is annoying to a purist etc...
  
 I have a really clean build been doing this stuff for 35 yrs +...solder skills are excellent here.
  
 But I did all the normal stuff you do, check for joints, everything tight, clean tube pins etc....even different rooms, power sources, cables etc...even re-soldered the power pin connections that look absolutely stellar.
  
 With the original 6AS7G the noise is always there very low....if I gently squeeze the top portion of the coke bottle the sound changes tone/frequency...and sometimes disappears!! Ha!
  
 I bought a second like tube from amplified parts in Arizona (great place to deal with). I got a 1953 NOS tube, still in the 1949 RCA wrapper/package.
  
 Fired it up and it is very sensitive and touchy for 30 - 40 minutes upon power up, it tests very well on my tube tester. But it is really touchy and has all kinds of noise that eventually settles out but always comes back in some shape or fashion.
  
 When listening I often hit pause to see if the noise or hum is there, and most often it is....it sounds like 60 cycle AC to me at times, Its there even with grounding plugs in the RCA input jacks.
  
 So I have one 6AS7G tube that's not too bad, sounds just great, its just that low hum/noise in the background that drive me nuts!! LOL.
  
 The second tube is worse and I have a replacement coming from amplified parts, these people are wonderful to deal with and sent out a replacement immediately!! No questions asked. Great customer service!
  
 Having dealt with many tube amps in the past....the old tube worts games is still here alive and well!!! Ha!
  
 That said its worth the minor pain and worts, the crack still sounds wonderful even with not perfect valves!.
  
 The speedball constant current "upgrade" is not yet installed but I will do this in the near future...
  
 Just wanted to share....
  
 Alex


----------



## FunyunBreath

Did you let the tube burn in for about 100 hours or so? I've noticed that just about all my 6as7g tubes that I've bought NOS have been a bit noisy at first. I emailed Brent Jesse about it on an RCA 6as7g I bought from him and he said because of the size of the plates they're pretty susceptible to microphonics for the first 100 hours or so of burn in. After that burn in period it generally goes away unless the tube is just very microphonic, in which case it's just a bad tube.
  
 Never really had the issue with 6080, 7236, or 5998 tubes though.


----------



## adydula

That's a good idea and I still have the 6AS7G tube with the worse sensitivity....I am going to let it "cook" for a few days, with tubes, metallurgy etc who knows it indeed might just fix itself.
  
 There are times its dead silent then it goes back to its temper-mental self!!
  
 I will try a straight bottle soon as well.
  
 Just like the aesthetics of these old coke bottle shaped tubes!! LOL.
  
 Parts Connextion had a 20% off sale and I have a 6080 on its way.
  
 Alex...ah the smell of hot vacuum tubes..especially when a layer of several old days dust burns off!!!


----------



## FunyunBreath

Ha yeah the crack looks way sexier with a 6as7g or 5998 than with a 6080 in it 
  
 For what it's worth I have 3 Tung Sol 5998's and haven't had microphonics in any of them. Very quiet tubes, in addition to being the nicest sounding ones I've tried as well.


----------



## DDDamian

funyunbreath said:


> Ha yeah the crack looks way sexier with a 6as7g or 5998 than with a 6080 in it
> 
> For what it's worth I have 3 Tung Sol 5998's and haven't had microphonics in any of them. Very quiet tubes, in addition to being the nicest sounding ones I've tried as well.


 
 True-say. And you're lucky - my 5998 has just developed a bit   Sporting a Winged-C right now while I seek another. Nice tube but not quite 5998...


----------



## FunyunBreath

Yeah thats the worst thing about tubes, and the reason why I'll never shell out more than $100 for a single tube. A $250 GEC brown base is worthless if it develops a hum a year later.
  
 Might not bother some people that much but my amps have to be dead silent or it just drives me crazy.


----------



## DDDamian

I hear ya. I can ignore it but that's not the point of high-end audio lol.
  
 Anyone tried dampers on that shape of a tube?


----------



## Mich4lle

Hello guys,

I have another question, I am about to buy a Tung-sol 5998 and an Amperex 12AU7 tube. I just got test results for these tubes and am just curious if they are good. I know that I should be able to read these results but they seem to differ based on the tube tester you use. Or at least as far as I know. Anyway so if somebody can tell how to to read these results that would be great.

5998

eG1 10.8 / 10.1 V
GM 14.56 / 15.00 mA/V


12AU7

GM 13.91 / 13.62
Gain 16.3 / 16.1
Noise 85.0 / 80.1

Thanks in advance for any help.


----------



## adydula

I emailed a person that sells the dampers for this tube and others, its a $50 option and fits on the fat part of the tube, I might try this in the near future after some more burn in and expeimentation,
  
 I totally agree on spending mega bucks on tubes that are well "tubes" that can have worts or work well for hundreds of hours...its all part of the tube game!
  
 Its a nostalgic thing for me, I grew up with these things and built radios, receivers and transmitters with 21+ tubes and did the alignments and biasing etc.....so putzing around is not a real issue just challenging at times regardless of the tubes used.
  
 Besides they look cool all glowing in the dark!! 
  
 LOL
  
 Alex


----------



## FunyunBreath

mich4lle said:


> Hello guys,
> 
> I have another question, I am about to buy a Tung-sol 5998 and an Amperex 12AU7 tube. I just got test results for these tubes and am just curious if they are good. I know that I should be able to read these results but they seem to differ based on the tube tester you use. Or at least as far as I know. Anyway so if somebody can tell how to to read these results that would be great.
> 
> ...


 
  
 GM is the measurement of plate current on each channel of the tube. To be honest the measurements really don't mean much unless the seller knows what they're doing and has accurately calibrated gear. There's only a few sellers online that I'll purchase high-priced tubes from because I know they have proper testing methods. Otherwise i'll only take a chance if they have a 14-day return policy


----------



## DDDamian

mich4lle said:


> Hello guys,
> 
> I have another question, I am about to buy a Tung-sol 5998 and an Amperex 12AU7 tube.


 
 I wouldn't be quite so paranoid. Every tube (even NOS) is a crap-shoot. If the seller has a decent reputation or an credible online business your odds are better than the usual crapshoot. As FunyunBreath says - check for a return policy.
  
 Even to reliable sellers the same adage applies: "How long does a light bulb last?". Sure - they have a finite life, some go dim fast, some pop when you turn them on. Wanna roll you gotta play.


----------



## JamieMcC

adydula said:


> I emailed a person that sells the dampers for this tube and others, its a $50 option and fits on the fat part of the tube


 
  
 Does it look anything like this 
	

	
	
		
		

		
			




  
http://www.amazon.com/SEOH-Flask-Weight-Vinyl-Lead/dp/B0088AR3K4   $3.62


----------



## Mich4lle

dddamian said:


> I wouldn't be quite so paranoid. Every tube (even NOS) is a crap-shoot. If the seller has a decent reputation or an credible online business your odds are better than the usual crapshoot. As FunyunBreath says - check for a return policy.
> 
> Even to reliable sellers the same adage applies: "How long does a light bulb last?". Sure - they have a finite life, some go dim fast, some pop when you turn them on. Wanna roll you gotta play.




Well that makes me feel better because I am buying it from vacuumtubes.net which I have only heard great things about and their responses have been great so I think I am going to go for it. Thanks for the help guys.


----------



## DDDamian

mich4lle said:


> Well that makes me feel better because I am buying it from vacuumtubes.net which I have only heard great things about and their responses have been great so I think I am going to go for it. Thanks for the help guys.




Best of luck. Yes they're a reputable seller and I think you'll really enjoy those tubes!


----------



## adydula

It looks like this from Herbie Audio:
  


 Alex.


----------



## FunyunBreath

mich4lle said:


> Well that makes me feel better because I am buying it from vacuumtubes.net which I have only heard great things about and their responses have been great so I think I am going to go for it. Thanks for the help guys.


 
  
 Vacuumtubes.net are awesome guys, I've bought my last few 5998's and 7236 tubes from them and they've all been great.


----------



## Whit3Rav3n

I found a Siemens Silver Plate input tube. Does anyone know if it is any good in the bottlehead?


----------



## FunyunBreath

Siemens silver plate tubes are among the best 12au7's you can find!
 I've been on the lookout for a deal on one but haven't come across any yet.
  
 On another note, anyone else tried the RCA cleartop + Tung Sol 7236 combo? I was never really a fan of the cleartops because I felt like they had too much emphasis on bass/treble and not enough mid-range goodness. Turns out I was just using them with the 5998 and in my opinion that's not a good combo for a more neutral signature.
  
 The cleartop has bass extension and slam where the 7236 lacks, and the mid-range emphasis on the 7236 makes up for the lack of mids in the cleartop. An amazing combo for rock and vocals!


----------



## Mich4lle

funyunbreath said:


> Vacuumtubes.net are awesome guys, I've bought my last few 5998's and 7236 tubes from them and they've all been great.




I just gave the go ahead, and I am so excited to hear what all the rage is about.


----------



## DDDamian

mich4lle said:


> I just gave the go ahead, and I am so excited to hear what all the rage is about.


 
 Hope to read your impressions


----------



## JamieMcC

Looks a good deal for a NOS military tube
  
http://www.partsconnexion.com/NOS-79665.html
  
 Compare to here
  
http://tctubes.com/Thomas-CSF-6080WA-tube-made-in-France.aspx


----------



## adydula

I just got one of these from Parts Connexion and its a wonderful tube at a GREAT price!!
  
 Go for it!!
  
 Alex


----------



## coastal1

funyunbreath said:


> Vacuumtubes.net are awesome guys, I've bought my last few 5998's and 7236 tubes from them and they've all been great.


 
  
 Interesting, I did not have a good experience with them a couple months ago.  I tried to order 3 tubes from them - a 5998 for $85, a Telefunken 12Au7 for $80, and a 6AS7G Chatham for cheap.  First they told me they no longer had the $85 5998, but they had a $150 5998 'bottom getter.'  There was no mention of top getter/bottom getter on their site when I ordered.  So I said scratch the 5998 and send me the other two.  Then they said they didnt have the Chatham and tried to upsell me on another tube, and said the Telefunken was highly microphonic.  So I went to Ebay and had good luck.


----------



## ohcrapgorillas

(headphones: HD600) I recently got a Winged C tube in and paired with the RCA Clear Top 12AU7, it's blowing my mind compared to the 5998. The soundstage is significantly improved, and I feel like it's much much more musical compared to the 5998's linearity. The 5998 is more dynamic and detailed in general, but the Winged C is so much more enjoyable. It also responds to the input tube completely differently...
  
 Listening with the 5998, my take on my 12AU7 tubes are:
  
*RCA Clear Top: *bright and revealing with a good timbre but lacking bass entirely, so meh (worth noting that the 5998/RCA combo with HD650 was absolutely jaw dropping)
*Genalex Gold Lion:* Awesome soundstage, great bass slam, rich mids, slightly recessed treble, spectacular for rock and metal
*Amperex made-in-Holland*: Totally natural through and through, sweet sound, the only choice for classical/jazz/anything well produced
  
 Now with the Winged C, it's become:
  
*RCA Clear Top:* amazingly clear and revealing and dynamic, incredible timbre and soundstage I didn't know HD600 were capable of, no lack of bass at all
*Genalex Gold Lion: *meh, a little too mid-centric IMO
*Amperex made-in-Holland: *warm, smooth, and sweet... still need more time for more 
  
 The range of sound available from the Crack-HD600 combination is incredible! Not to mention that the Winged C/RCA combo is so absolutely one of the best and most lifelike things I've ever heard. I was finding it hard to get work done last night because I was just so breathless from how good everything sounded. Definitely too revealing for poorly produced music, although I'd swear the 5998/Gold Lion combo can make bad recordings sound like good recordings.
  
 Still keeping my eye out for a good price on a Tung Sol 7236 then I swear I'm done buying (power) tubes for this thing...
  
 EDIT: Okay, the Amperex is insanely good. It doesn't have the unrealistically-realistic timbre of the Clear Top, but the soundstage right now is just awesome. It's also smoother, sweeter and more forgiving than the RCA at the expense of the uber detail in the treble and a little treble extension. I feel like I'm listening to really well recorded music, even though the production is maybe slightly better than average for what it is (_Feathergun_ by Rishloo--an album that sounds like injecting prog intravenously, so freakin' good).
  
 So,
  
 well recorded music: 5998 + Amperex, Winged C + RCA Clear Top
 'meh' to crap recordings: 5998 + Gold Lion, Winged  C + Amperex


----------



## JamieMcC

ohcrapgorillas said:


> (headphones: HD600) I recently got a Winged C tube in and paired with the RCA Clear Top 12AU7, it's blowing my mind compared to the 5998. The soundstage is significantly improved, and I feel like it's much much more musical compared to the 5998's linearity. The 5998 is more dynamic and detailed in general, but the Winged C is so much more enjoyable. It also responds to the input tube completely differently...
> 
> Listening with the 5998, my take on my 12AU7 tubes are:
> 
> ...


 

 You really need to try the E80CC for a your input tube Tungsrams are great value sound stage and resolution will blow your mind all over again.


----------



## DDDamian

Nice write-up @ohcrapgorillas, although I prefer the 5998 over Winged-C for it's detail and dynamics. The Winged-C I have is very musical but just seemed a bit dull after the detail of the 5998. These were with a Mazda CIFTE 12AU7 in the control seat. Ofc it all changes with mood and what you're listening to, what the optimal sound you seek is. They're both great power tubes!
  
@JamieMcC, I have a pair of NOS Tungsram ECC82's I haven't tried yet - will have to give 'em a roll. Hopefully they give a similar experience to what you found with the E80CC. I'm really digging the highly-detailed and lively sound lately out of my cans, even the warmer ones. It's nice to be able to get both the serene and the lively from the same amp with a couple of quick tube-changes - one of the beauties of a tube amp!


----------



## awry-fi

I could only afford a Project Sunrise (I'm one of the "lower impedance phones but still MUST TRY TUBES kiddies") and I just want to make it clear that I hate you all.


----------



## DDDamian

awry-fi said:


> I could only afford a Project Sunrise (I'm one of the "lower impedance phones but still MUST TRY TUBES kiddies") and I just want to make it clear that I hate you all.




Lol. We'll take that  hope you get to try one of the Bottlehead line one day.


----------



## rogerthatmand

Hey guys, I'd like to get some help. I finished building the Crack but I have some issues with the resistance check (the first step, the ohms).
 I have a volt-ohm-meter which I configure to 20K Ohms:
  
 Terminal 6, 10 - gives me 1.2K, instead of 2.4K.
  
 Terminals 14, 20, 22 - Doesn't show me nothing, instead of 0.
  
  
 Everything else is perfectly fine. 
 I doubled checked, I tripled checked and everything is soldered really well and everything goes exactly where it belongs.
  
 P.S - I did the REVISION part where I attach to terminal 14U instead of 22L, and I soldered it at the end of the procedure of building the Crack :
  
 "REVISION 5/6/10:
 Making this wire 3” long and
 connecting it to Terminal 14U
 instead of terminal 22L may
 yield more quiet operation."
  
  
  
 Please help me enjoying my Crack working as it should be


----------



## JamieMcC

rogerthatmand said:


> Hey guys, I'd like to get some help. I finished building the Crack but I have some issues with the resistance check (the first step, the ohms).
> I have a volt-ohm-meter which I configure to 20K Ohms:
> 
> Terminal 6, 10 - gives me 1.2K, instead of 2.4K.
> ...


 
  
 The Bottlehead forum is the best place to get trouble shooting advice, straight from those who designed the amp they will get you sorted out in no time.
 Link for the Crack section below.
  
http://bottlehead.com/smf/index.php?board=24.0


----------



## gab840

How does Bottlehead Crack comapre to IFI ICan??? 
 Also Crack has great synergy with HD650 & Beyer T1 & same Hp's are said to have a great comibnation with ICan
 So how does they fare against each other??


----------



## moriez

I'm back on the Crack's nest with the HD600 and HD650 after some solid state testing. Eventhough I hear there's room for improvement it's my favourite headphone listening rig for just about anything non-electronic. Right in that very sweet spot with the 5998/Cleartop.
  
 At any of the above tube guys, is the Winged-C anything like the Bendix 6080WB? Asking before buying. Don't want to start building a silly tube collection (less is more!)


----------



## Aeolus Kratos

Hi guys,
  
 I found something really interesting with the tube rolling for the Crack yesterday.
  
 Yesterday evening, I came over an audiophile friend of mine to listen to his "hi-end" speaker system. Then he asked me what setup I'm using at home, and I replied that I'm in love with the Bottlehead Crack and HD650 headphone. Then I showed him the Crack on the Bottlehead website, so he realized the Cracks use 12AU7 and 6080 variants for tubes.
  
 After that, he said that he once owned a pre-amplifier which used 12AU7s. He sold the pre but he still had several 12AU7 tubes left. Then he asked me if I wanted to buy his 12AU7 collection since he has no longer needed it. He offered me a great price for the package so I went ahead and bought all of his 12AU7 tubes.
  
 After that, he went upstairs and brought a small box which contained 5 12AU7s. I took the box back to my home and eagerly put the tubes into my beloved modded Crack.
  
 In 5 12AU7 tubes I bought, 2 of them were GE 12AU7s, 1 was a Mullard CV4003, 1 was a Electro-Harmonix 12AU7s (all the first 4 tubes still have a clear logo/printing name on the glass) and the final tube was unknown. All the printing code on the glass was worn out and I couldn't recognize what tube it is.
  
 I was very curious and decided to put the "mysterious" tube first into my Crack, the power tube was Tungsol 5998, let the tubes warm up for 30 minutes, plugged my HD650 and then gave it a listen. Then, something really magical happened....
  
*HOLY S**T!!! I was TOTALLY blown away!!!* The 3d soundstage and imgaing were breathtaking, the mid was crystal clear with the nice warmth, the bass was deep and very well controled, the highs were smooth and just full of energy. It sounds like no other. 
  
 Took a deep breath, I swapped in the new tubes I just bought from my friend and my existing collection to see if what I am hearing is just my imagination. And it's *NOT*. The "mysterious" tube was *CLEARLY* in a different league with all of my other tubes I've got.
  
 I've owned my Crack for nearly 2 years and I've tried VARIOUS input tubes in ALL tube types (12AU7s, E80CC, 12BH7s, 6SN7s), and by various I do mean I've tried all the "best" tubes of each type, but NONE of that came close. The tube is, without a doubt, the best of the bests I've heard with my Crack.
  
  
 The sound was sooooooooooooooooooooooooooooooooooo good that I really didn't want to listen to ANY other driver tube with my Crack. I immediately called my friend and asked him what the unknown tube is but unfortunately, he answered that he forgot as he bought all the tubes a long time ago and hadn't used them since.
  
 So I decided to post here, on the Crack thread. The pics of the unknown tube - the best input tube I've owned and tried with the Crack:
  

  

  

  

  

  

  

  

  

  
 I tried my best to picture all angles of the tube. The tube has long grey plates and D getter, with the code says "48L" and "47H".
  
 Does anyone know what tube is it?
  
 Thanks in advance!
 Kratos.


----------



## FunyunBreath

Maybe a ribbed plate Telefunken? If there's a diamond stamped into the glass on the bottom of the tube thats what it is. Construction looks almost identical to my smoothplate Tele.
  
 Also if you don't plan on using that Mullard CV4003 and it's in good shape shoot me a PM, I'd definitely be willing to make you an offer for it


----------



## JohnBal

aeolus kratos said:


> Hi guys,
> 
> I found something really interesting with the tube rolling for the Crack yesterday.
> 
> ...


 
 I think you may have stumbled upon an old Amperex Foil Strip D Getter. If so, that's a nice find. Enjoy.


----------



## NightFlight

Mystery tubes always sound better.  LOL. I had this GE that blew me away for quite a while, but eventually I rolled it. I still haven't gotten the 12BH7A out of my crack pre section.. but I've not turned the crack back on since I built the Mainline.... I've got to try an E80CC before the good ones vanish. 
  
 But yes, that Harleen plant has something magical about it. A proper 60's era grey shield 6922 Siemens & Halske in a Lyr will make you sit up an notice too. Blink. Then notice again. Repeat.


----------



## DDDamian

Nice find Kratos - whatever it is lol. I'd say send the pics to one of the bigger tube sellers (Tube Depot, etc) and see if they can give a positive ID. The codes you see on it will help. Let us know!!


----------



## moriez

nightflight said:


> Mystery tubes always sound better.  LOL.


 
  
 My thoughts exactly. The very effect unobtanium would have on me. Oh boy ^^
  


dddamian said:


> I'd say send the pics to one of the bigger tube sellers (Tube Depot, etc) and see if they can give a positive ID. The codes you see on it will help. _*Let us know!!*_


 
  
 Another effect of reading great enthusiasm is contagiousness. I believe at Vacuumtubes.net they're very knowledgeable and at Upscaleaudio seems a great guy. Give it a shot AK.
  
  

  
 I rolled in this Valvo E80CC but it's too smooth for my taste and prefer the CBS Hytron 5814 to it. Basically a good bit more air and detail to be heard. If there's anyone who wants to swap one of his tubes or wants to buy the Valvo off me send a PM.


----------



## Mich4lle

Hello everyone,

I am sorry that I am not the most helpful member and always need help but I have a new problem. 
So I am going to start at the beginning,
A couple of months ago the bolts that hold my RCA jacks to the chassis plate gave out and the RCAs shorted out against the chassis plate, which caused my crack to go quiet with some distortion in the background.
I then ordered new RCA jacks and installed them when they came. The new RCA jacks were a bit wider than the stock ones so I had to drill out the hole a bit. After this my crack worked for half of a song and then the signal slowly started distorting and by the end of the song there was basically no signal coming though. I then resoldered the RCA jacks and this made no difference. I then realized that the new Jacks needed an even bigger hole because they were still touching the chassis. I drilled the hole bigger and the RCA jacks then seated properly in the chassis. 
After this the signal louder but was still fairly distorted. I then resoldered the jacks again which made no difference.
I then turned the crack off and tried again the next day, it played perfectly for half a song again and the signal started degrading again to a point where there was almost no output.
This led me to believe that the problem is the power tube, because at this point there is nothing wrong with the RCA jacks that I can tell, and there is a worrying rattle coming from my power tube when shake it.
Am I right to think that the power tube is the problem?
Thanks in advance for any help, if I am unclear somewhere please let me know so I can clear it up.


----------



## DDDamian

mich4lle said:


> Hello everyone,
> 
> I am sorry that I am not the most helpful member and always need help but I have a new problem.
> So I am going to start at the beginning,
> ...


 
 If it works for a while and then displays the effects you're seeing then the tubes are one possible cause. A bad solder joint somewhere could also cause this (as a component warms up a bit and the connection worsens). Is it both channels or just one?
  
 Perhaps try the following:
 - try a different source
 - removed both tubes and inspect the pins for oxidation / discolouration. Gently clean with a small wire brush available at most dollar stores and re-seat them into the sockets
 - while their out carefully inspect them under the light and look for any connection issues inside - jiggle them a bit
 - power-up and note the intensity of the tube heater filament - does it change at all when the signal starts to distort?
 - after the power has been removed for a few minutes carefully inspect your solder joints everywhere. If this is happening to both channels I would suspect the power supply circuit or heater circuit, or the signal ground. If only one channel focus on the signal wiring for that channel
  
 If the above fails then grab a set of tubes off EBay or elsewhere and swap them out one at a time.
  
 If you still have no luck at least you'll have been able to rule out the obvious. Post in the appropriate Crack subforum over on the Bottlehead site, and be as specific as possible, including a concise statement of the effect (and whether it's one channel or both) along with what you've tried. Guys like P Joppa and Caucasion Blackplate there know the Crack inside out. A well-worded and concise post will often get a good reply within hours, but they need good info!
  
 Good luck


----------



## Mich4lle

Wow thanks for the great reply.
  
 The problem is across both channels and when I started it up today, there was just distortion straight of the bat, so I couldn't note a change in filament glow.
 In fact the signal barely came through at all. As far as I could tell the soldering was fine, So I think that it is the Power tube because it does have a bad rattle when I shake it gently.
 I have order new tubes and they will get to me soon. I just want to know if it will be safe to put them in the Crack, what if it isn't the tubes and the new ones get damaged, is that a possibility?


----------



## FunyunBreath

I'd order some cheap tubes just to have on hand in addition to the new one's you're getting. I like to have a cheap 6080 and 12au7 on hand for use after I mod the crack and want to make sure everything is in order without damaging a 5998 or something.


----------



## Aeolus Kratos

funyunbreath said:


> Maybe a ribbed plate Telefunken? If there's a diamond stamped into the glass on the bottom of the tube thats what it is. Construction looks almost identical to my smoothplate Tele.
> 
> Also if you don't plan on using that Mullard CV4003 and it's in good shape shoot me a PM, I'd definitely be willing to make you an offer for it


 
 Hi FunyunBreath,
  
 Thank you for your offer, unfortunately, I gave my CV4003 to another audiophile friend.
  
 Cheers.
  


dddamian said:


> Nice find Kratos - whatever it is lol. I'd say send the pics to one of the bigger tube sellers (Tube Depot, etc) and see if they can give a positive ID. The codes you see on it will help. Let us know!!


 
  
  


moriez said:


> My thoughts exactly. The very effect unobtanium would have on me. Oh boy ^^
> 
> 
> Another effect of reading great enthusiasm is contagiousness. I believe at Vacuumtubes.net they're very knowledgeable and at Upscaleaudio seems a great guy. Give it a shot AK.


 
 Hi guys,
  
 I'm just so glad that you guys gave me some really great advice and ideas. Thank you so much for that!
  
 And I'm very happy to confirm that I got my answer that I need. And I want to echo the excellent identification of this guy as he did give me an *EXACT* answer:
  


johnbal said:


> I think you may have stumbled upon an old Amperex Foil Strip D Getter. If so, that's a nice find. Enjoy.


 
  
 I sent an email to all the big tube dealers in the world as well as in my country and it seemed like I've got the same answer. Here is what tubedepot sent to me:
  


> I could be mistaken, but I think what you have here is an Amperex
> 12au7 Hamburg D-Getter that was actually not manufactured by Amperex
> but by Valvo in the early 50's. No guarantee, but it looks exactly
> like one, and these guys are truly rare treasures, so it's certainly
> where I'm putting my money.


 
  
 According to some tube dealers in my country and tubedepot, I really do believe that the unknown tube that blew me away is an Amperex (or Valvo) 7316 early 50's long plate foil "D" getter (with the "Ct0" code).
  
 Based on my own experience, I just can't recommend this tube enough for the Crack. I have to admit, I've tried *MANY* different input tubes in nearly *ALL* tube types for my Crack for the past few years (6SN7s, E80CCs, 12BH7, 12AU7 variants...) but none of the tubes I've tried can compete with the Amperex 7316 long plate "D" getter.
  
 I did some critical listening and comparisons between all the tubes I currently have in my collection (all the tubes I consider "best" before) over the last few days so I'm sure what I've heard was not my imagination. The 7316 sounds absolutely sublime with both my Bendix 6080WB slotted graphite column and Tung-sol 5998. The Amperex 7316 is truly an end-game tube for me, and the fact that it is an 12AU7 (which can be directly used with the Crack without any modification) is another plus. Get this tube and you no longer have desire for tube rolling anymore.
  
 One minor thing I want to add, from I've read, Amperex 7316s have many versions - long plates, short plates, "O" getter, halo getter, "D" getter, year of manufacture...my tube is an Amperex 7316 early 50's long plates "D" getter, so my experience and recommendation are just based on my tube. I can't be sure that all the Amperex 7316s sound the same.
  
 Best regards,
 Kratos.


----------



## DDDamian

Great that you got a positive ID (JohnBal was right on the money!). Off to scour my usual sources for one......Hope they don't read your post or the price will triple lol.
  
 Thanks for sharing your find and congrats!
  
 EDIT: wow - they are very expensive. Described by some as the "Holy Grail" of 12AU7's. Super-nice score


----------



## FunyunBreath

Mannnn I had an opportunity to pick up a 7316 one time for like $75 bucks and passed on it... Now i'm kicking myself.
  
 Off to look for one as well haha, thanks for the update!


----------



## moriez

A good read A K. I wish you a great time with it
	

	
	
		
		

		
		
	


	



  
 It has me pretty hyped up and to tell you the truth, I already butchered the internet to find one. The only thing that seems to be coming really REALLY close is an auction that started just yesterday! *Place your bets gents.* All in?


----------



## Aeolus Kratos

dddamian said:


> Great that you got a positive ID (JohnBal was right on the money!). Off to scour my usual sources for one......Hope they don't read your post or the price will triple lol.
> 
> Thanks for sharing your find and congrats!
> 
> EDIT: wow - they are very expensive. Described by some as the "Holy Grail" of 12AU7's. Super-nice score


 
 Hi DDDmanian,
  
 I actually just searched the price of the tube I have, and I was...speechless. These 7316s cost a small fortune!! And I'll definitely not tell my audiophile friend (who I bought my tube) the actual value of the tube he sold to me 
	

	
	
		
		

		
		
	


	



  
 Warm regards,
 Kratos.
  


funyunbreath said:


> Mannnn I had an opportunity to pick up a 7316 one time for like $75 bucks and passed on it... Now i'm kicking myself.
> 
> Off to look for one as well haha, thanks for the update!


 
 Hi FunyunBreath,
  
 You're very welcome.
  
 Cheers.
  


moriez said:


> A good read A K. I wish you a great time with it
> 
> 
> 
> ...


 
 Hi moriez,
  
 Thanks for your kind words, I really enjoy my Amperex 7316 very much 
	

	
	
		
		

		
		
	


	



  
 As for the bid for the Amperex 7316, it looks like the tubes in your link are the tube I currently have.
  
  
 Below is a pair of the 7316 in the link you posted:                                 

  
 And this is my tube

  
 So it seems my tube exactly is the same as the tubes which are on sale and more importantly, is exactly an Amperex 7316 long plates "D" getter.
  
 I strongly recommend you get this if you can afford it (although I got my 7316 for much less but I really think the ~$100 price tag for each of these is really worth it)
  
 Happy bidding and good luck!
  
 Regards,
 Kratos.


----------



## DDDamian

Reserve not yet met 10 bids in  
  
 Not sure if I'll join the bidding on those, but prices for a single out there are easily USD$225 from reputable dealers, tested NOS. Good luck to anyone bidding! Would love to trip across a box of them in some forgotten Eastern European warehouse - retirement would be that much closer


----------



## Oskari

aeolus kratos said:


> I tried my best to picture all angles of the tube. The tube has long grey plates and D getter, with the code says "48L" and "47H".


 
  


aeolus kratos said:


> According to some tube dealers in my country and tubedepot, I really do believe that the unknown tube that blew me away is an Amperex (or Valvo) 7316 early 50's long plate foil "D" getter (with the "Ct0" code).


 
  
 Can you verify the code?


----------



## Aeolus Kratos

oskari said:


> Can you verify the code?


 
 Hi Oskari,
  
 The particular my Amperex 7316 has ALL the codes on the tubes, all the codes were printed on different places on the glass. But you should stick with the "Ct0" code only.
  
 Cheers,
 Kratos.


----------



## Oskari

aeolus kratos said:


> The particular my Amperex 7316 has ALL the codes on the tubes, all the codes were printed on different places on the glass. But you should stick with the "Ct0" code only.


 
  
 Just wondering about your tube. 
	

	
	
		
		

		
			




  
 The factory/date code should be next to the Ct type code.


----------



## Maxhawk

Wonder how this compares to my own holy grail input tube, the 5687? I tend to gravitate towards the Sylvania gold brand 5687GB, but the T-S and GE 5687 are also very good and better than the others I have (perhaps 12-15 different variants including 12BH7 and ECC80). The asking price is a bit high for the sake of experimentation, but worth it (to me) if it truly is an end-game tube.


----------



## moriez

dddamian said:


> Reserve not yet met 10 bids in
> 
> Not sure if I'll join the bidding on those, but prices for a single out there are easily USD$225 from reputable dealers, tested NOS. Good luck to anyone bidding! Would love to trip across a box of them in some forgotten Eastern European warehouse - retirement would be that much closer


 
  
 I'm seeing it end up in the direction of $300 maybe even $400 as the reserve is still not met. For me there's just no way I'm spending ~$175 on one driver tube when I'm already getting that much WOW from the Crack as it is. Like you're saying Damian, the real fun is in finding them in secret rooms, pirate chests, homeless guy pockets and other W_ho Would Have Thought_ places


----------



## Doc B.

moriez said:


> I'm seeing it end up in the direction of $300 maybe even $400 as the reserve is still not met. For me there's just no way I'm spending ~$175 on one driver tube when I'm already getting that much WOW from the Crack as it is. Like you're saying Damian, the real fun is in finding them in secret rooms, pirate chests, homeless guy pockets and other W_ho Would Have Thought_ places


 
 You should have been into this in the early 90s. Guys would drive up to my house with carloads of loose tubes in cardboard boxes and ask me to take them, or help them by cleaning out basements and attics full of them. I recall pulling somewhere around 5000 tubes out of one hoarder's attic. I was also the only guy in my county who cared about LPs and I pretty much owned the bins in the thrift stores back then. 
  
 On the other hand, since nobody else cared about this stuff it was pretty hard to make a living selling it back then!


----------



## NightFlight

I believe it was Queens U where it was rumoured to have cleaned out a warehouse of lab grade tubes into a bin and had it crushed.  Lots of this has happened because those not in audio circles only see them as trash taking up space. 
  
 If I would have seen them crushed I would have likely collapsed... something like Roy Scheider did at the end of the movie 'Sorcerer'.  
  
 Speaking of LPs in the 90s. Ever make it to Car City Records in Detroit? That place was just amazing.


----------



## Doc B.

I met a couple of Russian guys many years ago, whose job in the army was to crush tubes for precious metals recycling. They figured they crushed several million between the two of them.


----------



## gab840

guys guys did you hear about the new crack announcement 
Crackotowa

Check bottlehead fb page or forums...


----------



## Rocketman248

Already ordered mine.


----------



## moriez

Cool! Was just starting to get interested in the S.E.X.
  
  

  
  
INTRODUCING: Crack-a-two-a headphone amplifier kit $699 (introductory price $599)  Crack-a-two-a is a premium version of the direct coupled Crack circuit with the C4S active loads of the Speedball incorporated, and also shunt voltage regulation in the form of two 6AQ5 tubes along with a bigger power transformer. There are three pairs of RCA input jacks and a volume and balance control. The standard potentiometer controlled volume/balance setup will be upgrade-able to a coarse and fine stepped attenuator very similar to the BeeQuiet attenuator used in the BeePre preamp and a similar style used in our most premium Mainline headphone amp. Like Crack this amp is intended to be used with high impedance headphones (200 ohms or higher) like Sennheiser HD600/650/800, Beyerdynamic 250 and 600 ohms headphones, etc. 

 One big consideration was that this kit was to fit between the Crack and the Mainline in terms of price. We wanted to keep the price below $700. Yes, the S.E.X. kit also fits in that price range, but there seems to be a devout following of high impedance headphone specific OTL amps that we wanted to address, and thus this alternative offering. With that in mind we decided that the biggest benefits would be from a more sophisticated power supply and the ability to upgrade to our very special stepped attenuator as used in BeePre (and in a slightly different form in Mainline). We also know that our customers like to have multiple switched inputs, so we include three. 

 Estimated shipping of the first kits will be in late September.


----------



## moriez

_Dat name though.. _Crack-a-two-a? 
	

	
	
		
		

		
		
	


	




 
  
 For apparent lack of commercial ingenuity may I propose rebaptizing to Bottlehead ''CATA'' or ''CAT''? Something!


----------



## JamieMcC

moriez said:


> Cool! Was just starting to get interested in the S.E.X.


 
  
 Looks like the Cracks gone to rehab and come out the other end a changed amp


----------



## Dimitris

Anyone in the Central Florida area that could help me with a problem on my 2nd crack?
 It seems like it has developed a cracking sound on one channel and I am not handy at all. Please PM me.


----------



## adydula

Sorry to hear this.... did u try to swap the tubes from the working unit?
 Alex


----------



## music max

Funny that you'd mention this because I just ran into the same problem with _my _crack. A crackling  sound in the right channel only. However, I haven't figured out how to fix this issue despite the fact that I recently replaced the power tube. If anybody has any suggestions, they'd be much appreciated.


----------



## adydula

Change the other tube as well..
  
 Alex


----------



## music max

I appreciate the suggestion. I'll give that a go and see if that works.


----------



## music max

Can someone recommend a relatively affordable input tube for the crack? I have a Tung Sol 5998 in the power section. Thanks


----------



## DDDamian

music max said:


> Can someone recommend a relatively affordable input tube for the crack? I have a Tung Sol 5998 in the power section. Thanks


 
 The usual answer is the RCA clear-tops - good detail and a very reasonable price.


----------



## music max

> The usual answer is the RCA clear-tops - good detail and a very reasonable price.


 
 Great. Thank you very much for your _input.... _no pun intended.


----------



## JamieMcC

music max said:


> Can someone recommend a relatively affordable input tube for the crack? I have a Tung Sol 5998 in the power section. Thanks


 
  
 The clear top is a very nice tube with the darker sounding hd650 but if are using cans like the hd800 in your avatar or  Beyerdynamics you may find the clear tops bright top end is to much of good thing giving to much treble emphasis. I would suggest having a look for a  Tung-sol 12au7 JTL or Black glass (1950's) for me they have a nicer midrange with the top end a little dialled back compared to the rca clear top meaning things don't sound overly bright as they can do with the clear top and these phones. They are reasonably priced and easy enough to find.


----------



## music max

jamiemcc said:


> The clear top is a very nice tube with the darker sounding hd650 but if are using cans like the hd800 in your avatar or  Beyerdynamics you may find the clear tops bright top end is to much of good thing giving to much treble emphasis. I would suggest having a look for a  Tung-sol 12au7 JTL or Black glass (1950's) for me they have a nicer midrange with the top end a little dialled back compared to the rca clear top meaning things don't sound overly bright as they can do with the clear top and these phones. They are reasonably priced and easy enough to find.


 
 This is very good to know. Given that I own the HD650s, I decided to go with the clear top. Like you said, I think the added top end will go very nicely with the HD650s and should be a good compliment to the 5998.


----------



## ohcrapgorillas

The clear top is a really spectacular tube, delicate details with amazing timbre and extension. Definitely a winner with the HD650. Also great with the HD600, but only for well-produced music.
  
 If you want something a little warmer, you could try to find a made-in-Holland Amperex tube for a decent price (good luck)--warm and sweet with a natural tone, more forgiving than the clear top but still not super forgiving.


----------



## music max

ohcrapgorillas said:


> The clear top is a really spectacular tube, delicate details with amazing timbre and extension. Definitely a winner with the HD650. Also great with the HD600, but only for well-produced music.
> 
> If you want something a little warmer, you could try to find a made-in-Holland Amperex tube for a decent price (good luck)--warm and sweet with a natural tone, more forgiving than the clear top but still not super forgiving.


 
 Yeah I looked into the Amperex and I'm not sure that its for me. If the clear top sounds like what you described, then I think it's perfect for my setup. And as another plus, they're super cheap.


----------



## daltonljj

I'm using the Amperex tube on my crack ... through my hd800 it simply sounds amazing ... its really worth getting your hands on one if you can get one at a good price


----------



## galyons

If you are not adverse to a bit of enlarging the hole and rewiring in a loctal or octal socket, 7N7's are dirt cheap but the loctal equivalent to very pricey 6SN7's.  I tried darn near every variety of AU7's available with my 5998.  In every case, the 6SN7/7N7 was substantially better.  There are some adapters available from the auction site if you want to try first.
  
 Cheers,
 Geary


----------



## adydula

I just picked up a very good Amperes NOS Bugle Boy 12AU7 for $32.....cant wait to try it..
  
 Alex


----------



## music max

galyons said:


> If you are not adverse to a bit of enlarging the hole and rewiring in a loctal or octal socket, 7N7's are dirt cheap but the loctal equivalent to very pricey 6SN7's.  I tried darn near every variety of AU7's available with my 5998.  In every case, the 6SN7/7N7 was substantially better.  There are some adapters available from the auction site if you want to try first.
> 
> Cheers,
> Geary


 
 This is a very interesting idea!! But I think the enlargement process might be a little bit out of my league. I may have to pick up an adaptor...


----------



## Dimitris

My issue is definitely not coming from the tube. If someone is in the central florida area please let me know as I am willing to pay a fee to have mine checked.


----------



## NightFlight

Tung-SoL input tubes are very correct sounding. You can't go wrong with them. They are a hair punchy like a good Amprex but polite across the board and not recessed either. You can find them on ebay for $10 or there about.
  
 http://www.ebay.ca/sch/i.html?_from=R40&_trksid=p2050601.m570.l1311.R10.TR11.TRC1.A0.H0.XTung+Sol.TRS0&_nkw=tung+sol+12au7&_sacat=0
  
 I found them to be a very good bargain tube against the 5998. Seems earlier dated the better as well.  I've gone down the holy grail rabbit hole with the Lyr and in terms of performance, my feeling the Tung Sol in the input section on a Crack is only second to some.


----------



## DDDamian

dimitris said:


> My issue is definitely not coming from the tube. If someone is in the central florida area please let me know as I am willing to pay a fee to have mine checked.


 
 Have you tried the BH forums? Specific questions with as much detail about what you've tried and tested as possible will often get very good answers from guys who know the circuitry very well.


----------



## JamieMcC

dimitris said:


> My issue is definitely not coming from the tube. If someone is in the central florida area please let me know as I am willing to pay a fee to have mine checked.


 
  
 Did you know Bottlehead offer a fixed fee repair service.
  
http://bottlehead.com/?product=repair-service


----------



## Doc B.

It's probably just a bad solder joint. Try reflowing the joints and yeah, you can get help on the Bottlehead Forum.


----------



## adydula

There are a lot of 5963 NOS tubes that work very very well with the crack...for about $15 or so a matched pair!
  
 Alex


----------



## music max

adydula said:


> There are a lot of 5963 NOS tubes that work very very well with the crack...for about $15 or so a matched pair!
> 
> Alex


 
 Wow that seems like a pretty good deal presuming that they sound decent with the Crack.


----------



## adydula

5963's are a good 12AU7 substitute....I have several and they all sound great..the price is not too crazy but that will probably change with time.
  
 Alex


----------



## krikor

Went to the estate sale of a former electronics repair man and audio engineer over the weekend, and picked up a bunch of 12AU7 tubes and a couple of "Winged C" 6AS7 tubes. May have overpaid, but it went to a good cause. Not sure if what I've got is any good, and I don't have any way of testing other than giving them a listen, though it will be fun trying these out. Gave one of the 6AS7 a listen with an older looking Mullard 12AU7 (says Made in Great Britain), but there was some background noise/hiss/rushing. Swapped it out for an RCA clear top which on a brief listen sounded OK, albeit a bit subdued and lacking detail, however the noise was gone so it must have been the Mullard and not the 6AS7 with the problem. Then swapped in another Mullard that looks a bit more recent (says Made in England) and that was quite nice sounding. Can't wait to have some time to explore all these further.
  

  
 Sylvania, Tung-Sol, Telefunken and Mullard... 

  
 Misc. unmarked long plates

  
 Four unmarked short plates

  
 Some strange ones:

  
 Clear top RCA looks like it might have some damage on the top (not sure if this could affect sound)


----------



## DDDamian

Dude, nice score  happy rolling....


----------



## JustinBieber

Is it okay to use 12au7a tubes in the Crack instead of 12AU7?


----------



## adydula

Yes..check the tube rolling thread over at Bottlehead...
 Alex


----------



## JustinBieber

Has anyone added carbon fiber wrap to the top base? Any problems with heat from the tubes? 

I'm thinking of getting 3M wrap, black stain for the wood, and some smoked tubes. It will look great.


----------



## JamieMcC

justinbieber said:


> Has anyone added carbon fiber wrap to the top base? Any problems with heat from the tubes?
> 
> I'm thinking of getting 3M wrap, black stain for the wood, and some smoked tubes. It will look great.


 
  
 I would expect a good quality automotive vinyl such as 3M would easily cope with the moderate temperatures the Cracks top plate reaches.
  
 A while back I was looking at doing something like the link below for a Crack build as you can get the thermal chromate liquid crystal in vinyl wrap sheet form now and can cut it to suit.
 I tried out a sample strip and it worked well the only reason it didn't proceed was the vinyl came in two temperature ranges and all the 30-60 degree C product was out of stock and only the lower 20-35 degree C was available which meant when at working temperature the vinyl had fully changed to a solid colour all over which was not what I was looking for. 
  
https://www.youtube.com/watch?v=peewxRlNVqg


----------



## JustinBieber

Thanks. I just ordered a sheet. Will update when I install it.


----------



## DDDamian

justinbieber said:


> Thanks. I just ordered a sheet. Will update when I install it.


 
 If it's a real carbon-fiber sheet you have no worries - there's some beautiful work done with that in the gallery over at the BH forum.


----------



## moriez

Hey guys. Need a little help.
  
 When I first received my pre-build Crack the bell end was slightly corrosive. Don't ask me why or how. I took it off to sandpaper it with non too good result so I recently bought a nice black replacement. What I remember from taking the bell end off and especially trying to screw it back on, is that it was SUPER tedious task that I'd never repeat in my life! Well, it must be done. The solution may seem obvious to some of you but what is the easiest way to replace the bell end for an unexperienced DIY-er? Special attention anywhere?


----------



## Ritchiepurple

Hi guys,
  
 I recently tried installing the speedball upgrade to my bottlehead crack but now the damn thing wont work at all. I have asked on the bottlehead forum and they provided tons of help but I just can't seem to fix it. Is there anyone UK based on the forum that would be willing to repair it for me and getting it into full working order? I would of course be willing to pay.


----------



## JamieMcC

ritchiepurple said:


> Hi guys,
> 
> I recently tried installing the speedball upgrade to my bottlehead crack but now the damn thing wont work at all. I have asked on the bottlehead forum and they provided tons of help but I just can't seem to fix it. Is there anyone UK based on the forum that would be willing to repair it for me and getting it into full working order? I would of course be willing to pay.


 
  
 Can you post a link to the trouble shooting advice already given to you on the BHF?


----------



## DDDamian

moriez said:


> Hey guys. Need a little help.
> 
> When I first received my pre-build Crack the bell end was slightly corrosive. Don't ask me why or how. I took it off to sandpaper it with non too good result so I recently bought a nice black replacement. What I remember from taking the bell end off and especially trying to screw it back on, is that it was SUPER tedious task that I'd never repeat in my life! Well, it must be done. The solution may seem obvious to some of you but what is the easiest way to replace the bell end for an unexperienced DIY-er? Special attention anywhere?


 
 I had the same issue - I just spent some time masking the whole unit and gave it a few coats with a spray bomb. Sorry, haven't removed the original....


----------



## Beefy

How is the market for built/used Cracks with tube complements including a pair of lightly used 5998's? I love the one that I built, but I just don't get the chance to listen to it anymore...... 
	

	
	
		
		

		
			




  
 Original construction post here: http://www.head-fi.org/forum/thread/476650/crack-bottlehead-otl/435#post_7149721


----------



## DDDamian

beefy said:


> How is the market for built/used Cracks with tube complements including a pair of lightly used 5998's? I love the one that I built, but I just don't get the chance to listen to it anymore......
> 
> 
> 
> ...


 
 There's always a market for pre-builts. You can list it on CAM or right here in the classifieds.


----------



## JamesBr

dddamian said:


> There's always a market for pre-builts. You can list it on CAM or right here in the classifieds.


 
 +1


----------



## Ritchiepurple

jamiemcc said:


> Can you post a link to the trouble shooting advice already given to you on the BHF?


 
 http://bottlehead.com/smf/index.php?topic=7989.0


----------



## JamieMcC

ritchiepurple said:


> http://bottlehead.com/smf/index.php?topic=7989.0


 
  
 Ok thanks I had a read through. I would advise for the next step to take some pictures of the speedball and add them to your post on the BHF having a few pictures added to your post there may prove really helpful.


----------



## moriez

dddamian said:


> moriez said:
> 
> 
> > Hey guys. Need a little help.
> ...


 
  
@JamieMcC
  
 You have build a dozen Jamie. Anything you can think of?


----------



## JamieMcC

moriez said:


> @JamieMcC
> 
> You have build a dozen Jamie. Anything you can think of?


 
  
 Sorry but am clean out of ideas for that. Personally I would rather try and refinish a bell end while its in situ rather than face having to take it all apart.


----------



## Loquah

moriez said:


> Hey guys. Need a little help.
> 
> When I first received my pre-build Crack the bell end was slightly corrosive. Don't ask me why or how. I took it off to sandpaper it with non too good result so I recently bought a nice black replacement. What I remember from taking the bell end off and especially trying to screw it back on, is that it was SUPER tedious task that I'd never repeat in my life! Well, it must be done. The solution may seem obvious to some of you but what is the easiest way to replace the bell end for an unexperienced DIY-er? Special attention anywhere?




That's a tricky job to be sure. I've done it once, but there's no easy way that I've found. From memory it required propping (securely) the chassis on its side and unscrewing one screw at a time with a screwdriver and pliers (for the nuts / terminal strips). The biggest challenge is catching and keeping the star washers. All of the terminal strips, etc. will hold their position due to the wiring so that helps.

Sorry I don't have an easy answer.


----------



## Loquah

ritchiepurple said:


> http://bottlehead.com/smf/index.php?topic=7989.0




How did you go with Paul's last response? Did you try the jumper he suggested and check the resistors?


----------



## moriez

jamiemcc said:


> Sorry but am clean out of ideas for that. Personally I would rather try and refinish a bell end while its in situ rather than face having to take it all apart.


 
  


loquah said:


> That's a tricky job to be sure. I've done it once, but there's no easy way that I've found. From memory it required propping (securely) the chassis on its side and unscrewing one screw at a time with a screwdriver and pliers (for the nuts / terminal strips). The biggest challenge is catching and keeping the star washers. All of the terminal strips, etc. will hold their position due to the wiring so that helps.
> 
> Sorry I don't have an easy answer.


 
  
 Thanks for the response Jamie and Loquah. Looks like it's going to be a few hail marys before a just-do-it then. I'll consult an astrologer for the best time


----------



## daltonljj

Some pics of my newly rebuilt crack with modifications.


----------



## Mich4lle

That looks great,


 


Is that a Khozmo attenuator? If it is, then your case must be massive, because it looks so small. 


But good job.


----------



## audiowize

ritchiepurple said:


> Hi guys,
> 
> I recently tried installing the speedball upgrade to my bottlehead crack but now the damn thing wont work at all. I have asked on the bottlehead forum and they provided tons of help but I just can't seem to fix it. Is there anyone UK based on the forum that would be willing to repair it for me and getting it into full working order? I would of course be willing to pay.


 

 Did you try the suggestion that I posted three months ago in this thread?


----------



## daltonljj

mich4lle said:


> That looks great,
> 
> Is that a Khozmo attenuator? If it is, then your case must be massive, because it looks so small.
> But good job.


 
  Yeah it is a khozmo .. but it aint super massive the width and length increased by 1 inch


----------



## Ritchiepurple

audiowize said:


> Did you try the suggestion that I posted three months ago in this thread?


 
 If you mean the suggestion regarding the jumper on the bottlehead forum then yes I did and sadly to no avail! I've been busy with work so not tried anything since the jumper suggestion three months ago but now I have a bit more time I am re-picking up the project.My worry is that the issue was there pre-speedball install and I made it worse doing the upgrade. It had been a while since I had listened to the amp and foolishly went straight in with the speedball so it's making it more difficult to pin point the issue.


----------



## JustinBieber

What size is the 9 pin socket? I don't have my crack w/ me to measure right now.
  
 I have options on eBay for 7/8, 3/4, and 1 1/8 in. With top or bottom style mounting. What should I choose? Thanks
  
 Edit: Nvm it's 7/8


----------



## NightFlight

ritchiepurple said:


> If you mean the suggestion regarding the jumper on the bottlehead forum then yes I did and sadly to no avail! I've been busy with work so not tried anything since the jumper suggestion three months ago but now I have a bit more time I am re-picking up the project.My worry is that the issue was there pre-speedball install and I made it worse doing the upgrade. It had been a while since I had listened to the amp and foolishly went straight in with the speedball so it's making it more difficult to pin point the issue.


 
  
 Well, split the amp into block components. 
  
 You can pull out the larger C4S board and with heat sinks and replace the 3K cathode resistors (ref: page 18 of the speedball manual). Reinstalled as per page 32 in the Crack manual.  This will effectively split the problem your speedballl install in half. Then if the issue persists, remove the speedball plate load C4S boards and replace the plate load resistors.
  
 Then if the issue persists post photos at the BH forum at that point and you'll catch PB's notice. That should also help to reveal a wiring issue if there is one.


----------



## Armaegis

daltonljj said:


> .. but it aint super massive the width and length increased by 1 inch


 
  
 So those herbal supplements have been working eh? 
	

	
	
		
		

		
			




  
 But seriously, nice build. The mirror finish must have taken _forever_... do you ever get paranoid about smudging it?


----------



## daltonljj

armaegis said:


> So those herbal supplements have been working eh?
> 
> 
> 
> ...


 
 yeah those herb did help ... now all the chicks love it ... haha
  
 The mirror finish took me a day to get it. Just good old sanding paper and finish off with some metal polish ... can recommend if you ever need ... haha


----------



## Armaegis

What brand polish did you use? And did you do it all by hand? Did you put a clearcoat on top?


----------



## daltonljj

armaegis said:


> What brand polish did you use? And did you do it all by hand? Did you put a clearcoat on top?


 
 I used this polish http://www.amazon.com/Mothers-05106-Billet-Metal-Polish/dp/B000COU7LG/ref=sr_1_3?ie=UTF8&qid=1439870645&sr=8-3&keywords=mothers+metal+polish. Before I started the build i tried out various bands to see what was good and this is by far the best in my opinion. All done by hand but i believe with a power tool you can definitely get the shine much faster.
  
 And no clearcoat ... Kinda worry that I may not do a good job for the clear coat that may lead to bubbles or uneven surface so left it clean ... but then the metal polish protects the metal quite well.The plate was the first thing I did and its been 2 months and still good and shiny.


----------



## Armaegis

Interesting. I've preferred Meguiars over Mothers for their wax products, but have never tried the metal polishes.


----------



## Whit3Rav3n

moriez said:


> Hey guys. Need a little help.
> 
> When I first received my pre-build Crack the bell end was slightly corrosive. Don't ask me why or how. I took it off to sandpaper it with non too good result so I recently bought a nice black replacement. What I remember from taking the bell end off and especially trying to screw it back on, is that it was SUPER tedious task that I'd never repeat in my life! Well, it must be done. The solution may seem obvious to some of you but what is the easiest way to replace the bell end for an unexperienced DIY-er? Special attention anywhere?


 
 I did a repaint of the bell end a cuple of weeks ago. It wasn´t that bad because the pwer transformer and the terminals around it were sort of held in place by all the wires. For reassembly I just held the chassis plate vertically and screwed the screws into the terminals. For the nuts I used a needle nose plier because there is not enough room to get to them with a wrench.


----------



## Thenewguy007

Hey guys, I just want to know if I buy a pre-assembled Bottlehead crack, can I later add the Speedball upgrade & the S.E.X. upgrade?

 What exactly are the Speedball & S.E.X. upgrades?
  
 Are they relatively simple to add, like they are just one extra piece that you can quickly solder to the board & that's it?
  
 Or would they be much harder & longer to add. Like having many new parts to solder, including un-soldering some part of the original board & then re-soldering them to accommodate the new upgrades?


----------



## mithrandir38

thenewguy007 said:


> Hey guys, I just want to know if I buy a pre-assembled Bottlehead crack, can I later add the Speedball upgrade & the S.E.X. upgrade?
> 
> 
> What exactly are the Speedball & S.E.X. upgrades?
> ...


 The S.E.X. is a different kit altogether. Speedball is relatively easy to install


----------



## adydula

Why don't you go over to the Bottlehead site and ask the experts at Bottlehead about details of the Crack and their product line. They have a great forum and many people that have built cracks and added speedball upgrades etch...
  
 Alex


----------



## Maxhawk

thenewguy007 said:


> Hey guys, I just want to know if I buy a pre-assembled Bottlehead crack, can I later add the Speedball upgrade & the S.E.X. upgrade?
> 
> What exactly are the Speedball & S.E.X. upgrades?
> 
> ...


 
  
 There are 3 small PCBs that you will have to stuff with parts, roughly 17-20 parts in total counting off the top of my head. There are two 10W sand cast resistors that will have to removed and a PCB wired in its place. Lastly there are two smaller resistors that will need to be removed to be replaced with the last 2 remaining PCBs. 
  
 So it's more like your last statement, but realize there is no board in the original. Everything is point to point wiring with tube sockets and terminal strips. If you head to the bottlehead forum there is a gallery post where you can see lots of pics.


----------



## Thenewguy007

maxhawk said:


> There are 3 small PCBs that you will have to stuff with parts, roughly 17-20 parts in total counting off the top of my head. There are two 10W sand cast resistors that will have to removed and a PCB wired in its place. Lastly there are two smaller resistors that will need to be removed to be replaced with the last 2 remaining PCBs.
> 
> So it's more like your last statement, but realize there is no board in the original. Everything is point to point wiring with tube sockets and terminal strips. If you head to the bottlehead forum there is a gallery post where you can see lots of pics.


 
  
 That's just for the speedball upgrade right?
  
 I would feel at ease if there was a simple video of it being added with instructions & tips.
 I seen a few videos for assembling the Bottlehead, but nothing on the speedball upgrade.


----------



## Maxhawk

thenewguy007 said:


> That's just for the speedball upgrade right?
> 
> I would feel at ease if there was a simple video of it being added with instructions & tips.
> I seen a few videos for assembling the Bottlehead, but nothing on the speedball upgrade.


 
 Yes that's just for the speedball. When you purchase the speedball kit, it comes with a nice PDF installation guide with lots of detailed pictures and instructions showing you how to build the boards and make the connections. You do need to be good with a soldering iron, and the more difficult part I think will be removal of installed resistors and wires since they'll likely be wrapped around eyelets and soldered in place. Solder wick will help remove the solder but you have to be careful not to overheat things.
  
 Here's are a couple of random image I found on the internet, one original and one with the speedball kit installed:


----------



## Thenewguy007

So the Speedball is those 4 chips/boards & extra two capacitors along with the long black things on the chips.


----------



## Doc B.

maxhawk said:


> the more difficult part I think will be removal of installed resistors and wires since they'll likely be wrapped around eyelets and soldered in place. Solder wick will help remove the solder but you have to be careful not to overheat things.


 
 Nah, just cut the suckers out and install the new stuff. I think builders inadvertently mess up more stuff trying to desolder and unwrap leaded components than they do when just cutting out the old part and soldering in the new one.


----------



## JamieMcC

I don't know why but untidy braiding really bugs me. Its pretty quick and easy to do a 3 strand braid once you know how.


----------



## adydula

Put the three wires in a drill chuck, hold the other end with pliers or in a vise, turn on drill slowly and you will get very neat evenly spaced braids etc....
  
 Alex


----------



## Maxhawk

thenewguy007 said:


> So the Speedball is those 4 chips/boards & extra two capacitors along with the long black things on the chips.


 
  
 The 2 caps are the original ones, simply bent over 90 degrees to give clearance for the boards. Those "long black things" are heat sinks. The large 3K resistors are replaced by the board with the 2 heat sinks. There are two smaller resistors soldered directly to the terminal strip at the bottom. Those are each replaced by a small board.
  
 And Doc's advice is good. If you're not super handy with a soldering iron, cut the leads and solder to the stubs left behind.


----------



## Armaegis

doc b. said:


> Nah, just cut the suckers out and install the new stuff. I think builders inadvertently mess up more stuff trying to desolder and unwrap leaded components than they do when just cutting out the old part and soldering in the new one.


 
  
 The second and third time I built a Crack, I left a little more lead space on the resistors that would be replaced by Speedball, making them easier to cut out. Similarly, I installed the caps laying down and spaced out further, so I wouldn't have to bend them later.
  
 The very first time I installed the Speedball, I had to use a dremel cutting disk to get the big cast resistors out because it was too tight to fit in some wire cutters.


----------



## adydula

Ha!!
  
 I just used solder wick and got them out np...
  
 A.


----------



## adydula

Lately I found a RCA 6AS7G and a old NOS 5963 Sylvania that have been just magical to me... at a very low cost compared to the :RARE priced out of this world stuff..
  
 A.


----------



## JustinBieber

Got the carbon fiber wrap in. I used 3M 1080 wrap. It's very easy to work with as long as you have a heat gun. Hair dryers take way too long to heat it up.


----------



## Mich4lle

justinbieber said:


> Got the carbon fiber wrap in. I used 3M 1080 wrap. It's very easy to work with as long as you have a heat gun. Hair dryers take way too long to heat it up.




I have the same soldering iron.  That looks pretty cool. What does your base look like? Or if you haven't done it yet, what plans do you have for it? And are you planning to listen to Justin Beiber on it?


----------



## moriez

moriez said:


> I rolled in this Valvo E80CC but it's too smooth for my taste and prefer the CBS Hytron 5814 to it. Basically a good bit more air and detail to be heard. If there's anyone who wants to swap one of his tubes or wants to buy the Valvo off me send a PM.


 
  
 Just a little follow up. The Valvo is actually quite a suitable tube when listening with my HD540 which has a tendency to sound bright. Going to hold on to it.
  
  
 Quote:


jamiemcc said:


> Looks like the Cracks gone to rehab and come out the other end a changed amp


 
  
 Jamie, any plans of building yourself one of these Crack-a-two-a's?
  
 Or two? (hint ^^)


----------



## JamieMcC

justinbieber said:


> Got the carbon fiber wrap in. I used 3M 1080 wrap. It's very easy to work with as long as you have a heat gun. Hair dryers take way too long to heat it up.


 

 Nice job, using vinyl wrap opens up a lot of great finish options. I like the look a lot and painting the 12au7 socket clip and screws is a nice detail  Its also easy to mount the retaining clip from underneath.
  
  

  
  
  
  
  


moriez said:


> Jamie, any plans of building yourself one of these Crack-a-two-a's?
> 
> Or two? (hint ^^)


 
  
 Hi Maurice
  
 Not at the moment but maybe in the future. Things are a little hectic for me the moment I have a couple of other projects under way another Pass ACA amp build and a little ZMR 250 fpv racer due to start (waiting for parts) which I need to finish before taking anything else on. Add into the mix my other half is expecting due in September so spare time will be in short supply for the foreseeable future.


----------



## Armaegis

justinbieber said:


> Got the carbon fiber wrap in. I used 3M 1080 wrap. It's very easy to work with as long as you have a heat gun. Hair dryers take way too long to heat it up.


 
  
 Isn't carbon wrap usually shinier? Or is it just the angle/lighting?


----------



## JustinBieber

Whoops, double post!


----------



## JustinBieber

armaegis said:


> Isn't carbon wrap usually shinier? Or is it just the angle/lighting?


 
 I got mine in a matte finish. 
  


mich4lle said:


> I have the same soldering iron.  That looks pretty cool. What does your base look like? Or if you haven't done it yet, what plans do you have for it? And are you planning to listen to Justin Beiber on it?


 
 I hate that iron. Chisel tip + my clumsiness isn't a great combo. My base is lightly stained ebony. Lol, no Biebs, maybe my first album to listen to once I finish will be L.A Woman. One of my favorites.


----------



## moriez

> Originally Posted by *JamieMcC* /img/forum/go_quote.gif
> 
> Hi Maurice
> 
> Not at the moment but maybe in the future. Things are a little hectic for me the moment I have a couple of other projects under way another Pass ACA amp build and a little ZMR 250 fpv racer due to start (waiting for parts) which I need to finish before taking anything else on. Add into the mix my other half is expecting due in September so spare time will be in short supply for the foreseeable future.


 
  
 Hi. Gotcha and no worries. Was thinking if there's someone who I'd put a project like that in his hands it would be you. Not in the least place because we're relatively close to each other. Who knows what October/November looks like ^^ Fathers need quality time on their own as well!
  
 Anyone else of the fanboys thinking about or started building the Crack-a-two-a?


----------



## DDDamian

It looks tempting, but my sights are on the Mainline. I have a very nice Crack and a S.E.X. If the Mainline is even better then wow.


----------



## Jeb Listens

Hi guys, 
  
 Just waiting for my Speedball to arrive, but in anticipation I bought a Tungsram E80CC.  My alarm bells were raised a little bit because to my eye the boxes they arrived in seemed like modern reprints - just too perfect and the colours/details perhaps not quite right. 
  
 The tubes appear to be genuine as far as I can tell from comparisons with pictures I've seen but if anyone has any of these E80CCs in their collection would you mind taking a quick look at the photos below and just seeing if they check out with yours?  I am probably just being paranoid since, though not dirt-cheap,  they are not exactly the most valuable tubes out there so it's difficult to imagine anyone going to the trouble of producing a fake. 
  
 The date code is G6, which according to a table I found = Nov, 1960.   The lamp is shining on the pins - they are not gold, are quite dull and seem consistent with a tube of that age. 
  
 Much appreciated!
  
 Jeb


----------



## JamieMcC

jeb listens said:


> Hi guys,
> 
> Just waiting for my Speedball to arrive, but in anticipation I bought a Tungsram E80CC.  My alarm bells were raised a little bit because to my eye the boxes they arrived in seemed like modern reprints - just too perfect and the colours/details perhaps not quite right.
> 
> ...


 
 Hi Jeb they look fine to me, I have never seen or heard of fake E80CC. Its one of my favourite Crack input tubes from what I have read they look to have only ever been manufactured by two companies Philips who are also credited for their design (normally found with smooth plates) and Tungsram most commonly found with the holes essentially every other label it  appears is just rebranding of the tubes these two companies produced and can be found branded as CEI, Valvo, Siemens Halske, Telefunken, Haltron, Mullard etc with sellers asking silly prices for the same tube.
  
 There were a few variations over the years which have lead to versions like the pinched waist bottle and early foil getter varieties being more sought after.
  
 Keep yours eyes skinned and you might even find the holy grail of E80CC the Silver plate silver foil Tungsram 
	

	
	
		
		

		
			





 
  

  

  
 You might find this BHF thread interesting
  
http://bottlehead.com/smf/index.php?topic=5989.0


----------



## skeptic

jamiemcc said:


> ...Add into the mix my other half is expecting due in September so spare time will be in short supply for the foreseeable future.


 
  
 Congrats Jamie - that's wonderful!  Yeah, I daresay your project time will be more limited for a while going forward, but within a few years you'll no doubt have your little one helping you sort your parts and tighten down simple hardware.  There's also nothing like having a great headphone rig to turn to for a little relaxation during the baby stage when he/she does finally go down for the night (or part of it anyway).


----------



## Jeb Listens

Thanks Jamie and congratulations on the new addition to the family too!
  
 That is great information about the E80CC -  I think the tube is genuine- phew.   Lost a little of my faith in humanity after tube collecting over the last couple of years!  
  
 That BH thread was a great read.  You know, the calibre of some of the modification work done on the BH forum never ceases to amaze me!  
  
 I actually did not realise that the E80CC and 12BH7/A  required some circuit changes.  Perhaps that's something I can look at doing further down the line when I'm fully up and running with the Speedball and have built up some confidence.   The switch mod seem like a really nice solution, though looks a bit daunting right now.
  
 Is it acceptable to try the E80CC and 12BH7s with the stock Crack + SB to see if they are to my liking before deciding to make any circuit changes to optimise things ?


----------



## JamieMcC

Cheers,  looking forward to the new arrival as well but not the sleepless nights!
  
 Quote:


skeptic said:


> Congrats Jamie - that's wonderful!  Yeah, I daresay your project time will be more limited for a while going forward, but within a few years you'll no doubt have your little one helping you sort your parts and tighten down simple hardware.  There's also nothing like having a great headphone rig to turn to for a little relaxation during the baby stage when he/she does finally go down for the night (or part of it anyway).


 
  
 I think they should prescribe the Mainline HD800 combo for stress therapy.  I will definitely be using my rig for to help chill out, it works amazingly well.
  


jeb listens said:


> Is it acceptable to try the E80CC and 12BH7s with the stock Crack + SB to see if they are to my liking before deciding to make any circuit changes to optimise things ?


 
  
 Your E80cc will work fine with the Crack and Speedball. The resistor mod is basically a little fine tuning its inexpensive and works well.


----------



## Jeb Listens

Great - thanks again, - should be fun times ahead!


----------



## DDDamian

@JamieMcC - have you paired your Mainline with any orthos? Thoughts with those?


----------



## JamieMcC

dddamian said:


> @JamieMcC - have you paired your Mainline with any orthos? Thoughts with those?


 

 Hi I have only tried the HE-6 on it and as expected it doesn't have enough to oomph to drive them well.


----------



## DDDamian

jamiemcc said:


> Hi I have only tried the HE-6 on it and as expected it doesn't have enough to oomph to drive them well.


 
 Okay thanks - yeah that's a tough nut to crack for any amp.


----------



## Mahdi8

jeb listens said:


> Thanks Jamie and congratulations on the new addition to the family too!
> 
> That is great information about the E80CC -  I think the tube is genuine- phew.   Lost a little of my faith in humanity after tube collecting over the last couple of years!
> 
> ...




You can use it without modification just keep it mind crack with speedball ia not designed to handle the voltage of e80cc. It runs at a much higher gain and voltage. I have been using e80cc on an unmodified crack with speedball for 2 months with no problem. Then 2 weeks ago the speedball transistor finally gave up and burnt. So something to keep in mind. If you want to use this long term follow the resistor replacement guide in the bottlehead forum


----------



## Jeb Listens

mahdi8 said:


> You can use it without modification just keep it mind crack with speedball ia not designed to handle the voltage of e80cc. It runs at a much higher gain and voltage. I have been using e80cc on an unmodified crack with speedball for 2 months with no problem. Then 2 weeks ago the speedball transistor finally gave up and burnt. So something to keep in mind. If you want to use this long term follow the resistor replacement guide in the bottlehead forum


 

 Mahdi - I appreciate the heads-up about this - I hope your Crack is now back up and running!  
  
 During those couple of months did you like the E80CC enough to stick with it long-term & do the mod this time?


----------



## JamieMcC

mahdi8 said:


> You can use it without modification just keep it mind crack with speedball ia not designed to handle the voltage of e80cc. It runs at a much higher gain and voltage. I have been using e80cc on an unmodified crack with speedball for 2 months with no problem. Then 2 weeks ago the speedball transistor finally gave up and burnt. So something to keep in mind. If you want to use this long term follow the resistor replacement guide in the bottlehead forum


 
  
 Interesting not heard of that before.
  
 Thinking about it I must have had at least 1500 hours running the e80cc before I did the resistor mod this would also including letting the amp run 24/7 for a week or so on several occasions whilst evaluating different capacitors.
  
 The resistor mod is a no brainer imo it most probably costs about the same as a cup of coffee to implement and when done allows easy switching between 12au7 and e80cc optimum voltages.


----------



## Mahdi8

For me i used it for along tine too before it burnt. Think it like overclocking. Most ofnthe time its fine but since you are running the circuit above its designed voltage something can go wrong. BTW only transistor for one channel got burnt in my case.


----------



## Thenewguy007

Um guys about painting, staining & finishing the wood.
 I want to keep the default wooden color, but I do want it to have a semi-gloss finish.
  
 I never painted wood before in my life.
  
 So what would I do?
 I seen a couple youtube DIY videos & from what I gathered, I need to buy a pre-stain wood conditioner & use it on the wood.
 Then after it dries, I need to apply a protective polyurethane clear semi-gloss finish.
  
 Would that be it?

 Any advice on where to buy the cheapest/smallest cans, just enough for the 4 small boards of the Bottlehead Crack?
 Don't want to pay where I would have enough left to paint entire furniture or anything


----------



## Doc B.

You don't need any pre stain conditioner if you're not going to stain it. In fact you don't need any pre stain prep ever if you use the right kind of stain. The easiest thing to do is put on a linseed oil or tung oil type of finish like Birchwood Casey Tru-Oil. Or you can put on an oil or water base clear finish like Varathane or Minwax Polycrylic. Any of these are pretty easy to apply, just sand the base with 220 grit paper, lay on a coat of finish, let dry, and lightly sand and recoat as many times as makes you happy. Usually two or three coats is enough.


----------



## DDDamian

doc b. said:


> You don't need any pre stain conditioner if you're not going to stain it. In fact you don't need any pre stain prep ever if you use the right kind of stain. The easiest thing to do is put on a linseed oil or tung oil type of finish like Birchwood Casey Tru-Oil. Or you can put on an oil or water base clear finish like Varathane or Minwax Polycrylic. Any of these are pretty easy to apply, just sand the base with 220 grit paper, lay on a coat of finish, let dry, and lightly sand and recoat as many times as makes you happy. Usually two or three coats is enough.


 
 +1 - if you were lucky enough to get some nice grain in the wood the above will let it shine through nicely. I'm just a sucker for keeping the wood grain prominent, and stain conditioner won't help that. Of course it depends what you're going for - many nice examples in the Bottlehead forum galleries.


----------



## Loquah

dddamian said:


> It looks tempting, but my sights are on the Mainline. I have a very nice Crack and a S.E.X. If the Mainline is even better then wow.







dddamian said:


> @JamieMcC
> - have you paired your Mainline with any orthos? Thoughts with those?




The Mainline is a clear upgrade to both, even accounting for how great the Crack and SEX are.

As for orthos, the Mainline does a fine job with my LCD-2s. I choose to use them mostly with the SEX, but that's more a presentation / synergy preference because the SEX is tuned (via caps) to be perfect for my relaxed Ortho tastes.


----------



## JamieMcC

thenewguy007 said:


> Um guys about painting, staining & finishing the wood.
> I want to keep the default wooden color, but I do want it to have a semi-gloss finish.
> 
> I never painted wood before in my life.
> ...


 
  
 I would recommend docs method sand your enclosure after its all glued up with some 220 grit sandpaper going in the same direction as the grain wipe clean then use a clear/natural finish oil to bring out the grain. Once you have a few coats or oil I like the Danish Oil (a blend of varnish and Tung oil)  use some 0000 gauge steel wool to rub down and smooth all over then finish off by using some pate wax it and buff up to a satin/sem-gloss shine.


----------



## DDDamian

loquah said:


> The Mainline is a clear upgrade to both, even accounting for how great the Crack and SEX are.
> 
> As for orthos, the Mainline does a fine job with my LCD-2s. I choose to use them mostly with the SEX, but that's more a presentation / synergy preference because the SEX is tuned (via caps) to be perfect for my relaxed Ortho tastes.


 
 Wow - that's a pretty ringing endorsement. Cheers for that. I was intending the Mainline to pair with the HD800 as so many here swear by that combo, and I can see where all the added refinement to the sound will shine through them. Just wondered if it had the current to drive the planars as well as the SEX does. Honestly if there's improvement over my slightly modded SEX 2.0 (C4S, Mundorf Supremes, 2.1 iron, matched tubes) then I'll be truly impressed. The SEX has been good with all my cans, ortho or dynamic.
  
 Your reviews continue to be a reference standard for Bottlehead gear Loquah - haven't found anything I disagree with so far. I wish I'd jumped on the Mainline when the $Cdn was at par with the $USD, now it's at USD$0.74 with the drop in oil prices though.
  
 That aside, winter is coming (how Game of Thrones is that?) and it's time I started planning this build lol. Short of maybe some cap upgrades from the get-go and a highly-figured hardwood base (thinking either curly maple, birdseye maple or perhaps kauai) I haven't seen much in the way of upgrades to plan into it. Thinking that speaks very well for the stock amp!


----------



## Doc B.

Mainline puts out about 800mW and works very well with the planars that aren't crazy power hungry - LCD2 and 3s and most of the HiFiMan models - but not the HE-6. That needs more power, and the S.E.X.  (or Neothoriator) are a better choice for the really inefficient stuff like HE-6s and K1000s.


----------



## DDDamian

doc b. said:


> Mainline puts out about 800mW and works very well with the planars that aren't crazy power hungry - LCD2 and 3s and most of the HiFiMan models - but not the HE-6. That needs more power, and the S.E.X.  (or Neothoriator) are a better choice for the really inefficient stuff like HE-6s and K1000s.


 
 Thanks Doc. That's ample for any of the cans I have or plan on buying any time soon. The Neothoriator may have to wait for a more favourable exchange rate though. The price is a little out of my league, especially if you factor in the inevitable divorce


----------



## Thenewguy007

Any methods to clean the aluminum/metal top?
 Got some grease/dirt on it by accident & can't clean it up.
 I used degreasers, cleaning sprays, soap & water, distilled vinegar, scrubbing, toothpaste etc...
 The material doesn't seem to clean.
  
 All it does is spread/move around the dirt.
 It leaves the material with an uneven look, with patches that look cleaner/smoother than other parts.
 No matter how long I tried wiping it down with a soft microfiber cloth it doesn't come out evenly..
  
 I even tried a polishing tool, did nothing.


----------



## JamieMcC

Mainline + HD800 is very nice and while my modified Sex is more than decent with the HD800's to be honest my Sex for the most part has been relegated to speaker duty since the Mainlines arrival. When occasionally it does get used I find when its time to switch amps again plugging back into Mainline always brings a smile and I cant help but think too myself "damn this amp is good"


----------



## Doc B.

I haven't had a problem cleaning the panels with a degreaser like 409, but I don't know what the material is you have gotten on the panel. You could also go in a different direction and try WD-40. VMP Naptha is another thing you could try.


----------



## JamieMcC

thenewguy007 said:


> Any methods to clean the aluminum/metal top?
> Got some grease/dirt on it by accident & can't clean it up.
> I used degreasers, cleaning sprays, soap & water, distilled vinegar, scrubbing, toothpaste etc...
> The material doesn't seem to clean.
> ...


 

 If you have some nail varnish remover to hand that shifts most things.


----------



## Armaegis

Is it actual grease/oil, or is it a sticky film residue?
  
 Sometimes some dirt/cornstarch dabbled on will help dry/gunk up whatever the stuff is, then you can scratch it off with a fingernail or piece of plastic.


----------



## Doc B.

FWIW I just cleaned a panel before brushing with Windex today and it came out spotless.


----------



## Demoninja

Quick question, I have a very small collection of tubes, about 10 total. How do you guys store your tubes? It doesn't make sense for me to buy a large amount of boxes when I don't plan on getting more than maybe 15 tubes total.


----------



## Armaegis

step 1: Steal a couch cushion with soft squishy foam and remove from the covering
 step 2: stab X's into the foam
 step 3: insert tubes


----------



## DDDamian

armaegis said:


> step 1: Steal a couch cushion with soft squishy foam and remove from the covering
> step 2: stab X's into the foam
> step 3: insert tubes


 
 Or get one of those "executive sandboxes" and arrange your tubes in it. It looks like a working amp and protects the pins from oxidizing.
  
 Keep the kitty out of it.


----------



## Mich4lle

Wow, have I just been through an ordeal with my Crack,
 It all started with my RCA jacks failing, I then got a replacement for them, which worked for about half a song and then it gave out.
 I went through a long process to figure out what has gone wrong, I then assumed (Lets say made an educated guess) that the tubes gave out with the RCA kerfuffle.
 I then ordered some tubes, a Tung-sol 5998 and an Amperex 12AU7 Bugle boy, which took 6 weeks to struggle its way through South African customs.
 A couple of days before the tubes arrived I decided to listen to my HD 650's without the crack (I know blasphemy ) I plugged them into my Asus essence ST, which wasn't working.
 IT WAS THE SOUND CARD. I could have used my crack for the ENTIRE 6 weeks that I was patiently waiting for the tubes.
 The problem with this is that now I have to plug my Crack straight into the back of my PC, which is really very noisy, but I have my crack back, with new tubes.
 Besides the huge amount of noise that my PC puts onto the signal and that pretty awful quality of the on board DAC I have to say these tubes are unbelievable.
 Before I heard them I though the tubes would make a small but noticeable difference, but it really makes a very big difference,
 I understand what people mean about the HD650 "Veil" now.
 They bring significantly more treble presence to the party. I am hugely impressed.
 The next step is to get a new DAC, I was thinking an HRT music streamer ii, is this a good buddy for a Crack with HD 650's? I have only heard good things about it.
 Enough of the long winded story, I think it is picture time, I took the 6 weeks to also "Restain" the box of my crack.


----------



## JamesBr

mich4lle said:


> Wow, have I just been through an ordeal with my Crack,
> It all started with my RCA jacks failing, I then got a replacement for them, which worked for about half a song and then it gave out.
> I went through a long process to figure out what has gone wrong, I then assumed (Lets say made an educated guess) that the tubes gave out with the RCA kerfuffle.
> I then ordered some tubes, a Tung-sol 5998 and an Amperex 12AU7 Bugle boy, which took 6 weeks to struggle its way through South African customs.
> ...


 
 Excellent work man!


----------



## DDDamian

Those are among the favourite tubes out there - a nice upgrade for sure. Can't comment on the HRT Microstreamer, but at least you found the cause of your woes. There's a ton of good DACs out there now to choose from without breaking the bank.


----------



## Maxhawk

demoninja said:


> Quick question, I have a very small collection of tubes, about 10 total. How do you guys store your tubes? It doesn't make sense for me to buy a large amount of boxes when I don't plan on getting more than maybe 15 tubes total.


 
 I'm using an old tin from some peppermint bark for my small tubes and a large tin from a bottle of scotch and lined them with some foam I had laying around. More often than not, the boxes the tubes are shipped in aren't in great shape so this is a better solution for me. Plus I can easily move/carry them this way.


----------



## Doc B.

Wow you guys really get into this storage stuff. I just have a stack of file boxes full of tubes in the basement, and odd tubes scattered here and there all over the shop, the basement, the office...
It's like "Oh look, an egg crate full of Telefunkens. Forgot I had those".


----------



## adydula

I smell an opportunity here!!!!
  
 LOL
  
 Alex


----------



## Doc B.

Careful what you wish for. I had a storage unit about half full of tubes for many years, maybe 10,000?. A friend came over and drove away a jam packed Suburban full of them several years ago. He still has 'em, and his wife is still unhappy about it. Since that purge I'm down to 30 or so file boxes full. They get slowly consumed by various projects.


----------



## Armaegis

Time to build a brutish unsophisticated amp that uses a dozen tubes per side Doc


----------



## Doc B.

That was the plan years ago for the boxes full of 6080s I had. I was going to build a massive OTL amp with them. I even had some 6.3V 50A filament transformers to use. Then PB thought up the Crack, and they were all gone in a few weeks.


----------



## Demoninja

Aha one last question for now. Didn't feel like starting new threads on the Bottlehead forum directly for all these small questions. Is there any concern of the top plate rusting or was that just the bell end. I didn't paint either one of them before I assembled and I'm hesitant to disassemble the amp because of how long it took me to get a completely silent amp and I rather like the finish of the top plate already.


----------



## cspirou

demoninja said:


> Aha one last question for now. Didn't feel like starting new threads on the Bottlehead forum directly for all these small questions. Is there any concern of the top plate rusting or was that just the bell end. I didn't paint either one of them before I assembled and I'm hesitant to disassemble the amp because of how long it took me to get a completely silent amp and I rather like the finish of the top plate already.




I believe the top plate is aluminum and will never rust.


----------



## grausch

cspirou said:


> I believe the top plate is aluminum and will never rust.


 
 Aluminium does "rust", but it is not the same as iron that rusts https://answers.yahoo.com/question/index?qid=20061025141908AAhtPFu.


----------



## cspirou

grausch said:


> Aluminium does "rust", but it is not the same as iron that rusts https://answers.yahoo.com/question/index?qid=20061025141908AAhtPFu.




OMG! OK I don't want this to go off topic but rust as it is understood only applies to iron oxide and is also what the question is about. No one has ever referred to the oxidation of aluminum as rust and is in fact a desirable trait of aluminum since aluminum oxide results in a protective layer. Yahoo answers is generally an unrealible source for answers as well.


----------



## grausch

cspirou said:


> OMG! OK I don't want this to go off topic but rust as it is understood only applies to iron oxide and is also what the question is about. No one has ever referred to the oxidation of aluminum as rust and is in fact a desirable trait of aluminum since aluminum oxide results in a protective layer. Yahoo answers is generally an unrealible source for answers as well.


 
 Yeah, in hindsight I realise my post does not address what the question was really about. Aluminium oxidises pretty quickly, so by the time anyone receives a top plate that is what it will look like for the rest of its life, unless you of course damage it.
  
 OT - Untreated aluminium scuba tanks are also remarkably resistant to corrosion (not oxidation as they already formed the aluminium oxide) even though they are exposed to seawater on a daily basis. Painted aluminium scuba tanks however are exactly the opposite...I could never understand that though...Although that is specific to scuba tanks and I have not heard of a single case of that happening to painted top plates. Guess it is a good idea to never go diving with your Crack - especially if you painted the top plate...
	

	
	
		
		

		
			




  
 Scary as it is - in this case yahoo answers actually gave the easiest to understand answer when I googled. Another I can't quite understand...


----------



## krikor

grausch said:


> Yeah, in hindsight I realise my post does not address what the question was really about. Aluminium oxidises pretty quickly, so by the time anyone receives a top plate that is what it will look like for the rest of its life, unless you of course damage it.
> 
> OT - Untreated aluminium scuba tanks are also remarkably resistant to corrosion (not oxidation as they already formed the aluminium oxide) even though they are exposed to seawater on a daily basis. Painted aluminium scuba tanks however are exactly the opposite...I could never understand that though...Although that is specific to scuba tanks and I have not heard of a single case of that happening to painted top plates. Guess it is a good idea to never go diving with your Crack - especially if you painted the top plate...
> 
> ...


 
 Well, at the risk of continuing off the thread rails... You sure it's not painted steel tanks that have the problem? That I've heard of being issue both with steel scuba tanks and big rig steel wheels which have to be stripped and painted every so often (which makes Al alloy the better choice over time, not to mention the weight savings). 
  
 Could also be due to galvanic corrosion if there is any kind of dissimilar metal in the paint perhaps. Of course, this requires moisture which is present with scuba tanks, but hopefully not with your Crack amp


----------



## Doc B.

I'd suggest not trying to over-think this unless you are integrating your kit into an aircraft or an oil rig. We wash the laser cut panels in a dishwasher with low phosphate detergent and then they are brushed. Almost immediately an invisible layer of oxide forms on the brushed surface. The panel surface is fine left naked as long as you don't leave your AC powered amp sitting in the acid rain or at the bottom of the ocean. It can be painted if you wish and the slightly rough brushed surface will help the paint to adhere. I do suggest giving the panels a good cleaning with a degreaser like Formula 409 or for the more daring among you, acetone, before painting since we have no control over what may have gotten on the surface once the package is opened.
  
 If you really like to fret about this stuff have your panel anodized, then have it powder coated. That will hold up to damp and salty environments that you should never put one of our kits into.


----------



## grausch

Well said Doc - my top plate is left as is and I see no need to paint or clearcoat it. I still occasionally marvel at just how beautiful the brushed aluminium can look.
  
 krikor - painted aluminium has the issue with corrosion. Steel tanks have almost no issue - not sure at all, but I think they are hot galvanised and not painted. Used to live in the Caribbean and was good friends with several dive operators - all of those used alu tanks, so that is what my experience is based on. No experience with steel tanks unfortunately and no scientific background as well.


----------



## JamieMcC

grausch said:


> Well said Doc - my top plate is left as is and I see no need to paint or clearcoat it. I still occasionally marvel at just how beautiful the brushed aluminium can look.
> 
> krikor - painted aluminium has the issue with corrosion. Steel tanks have almost no issue - not sure at all, but I think they are hot galvanised and not painted. Used to live in the Caribbean and was good friends with several dive operators - all of those used alu tanks, so that is what my experience is based on. No experience with steel tanks unfortunately and no scientific background as well.


 

 Going slightly off topic but my experience with tanks is that steel dive tanks generally have a longer service life than alloy ones due not down to corrosion issues but to the service life as alloy ones are more prone to scrapes and dings. In the UK 2mm dent in a alloy tank will mean it fails testing and it doesn't take much to ding a alloy tank in regular use. Steel ones bounce much better  
	

	
	
		
		

		
		
	


	




  It is also reasonably inexpensive to shot blast and re galvanise the inside of steel tank to extend its life span. Mind you scuba tanks are lot more affordable than they used to be so I doubt that gets done much nowadays.


----------



## Doc B.

grausch said:


> Well said Doc - my top plate is left as is and I see no need to paint or clearcoat it. I still occasionally marvel at just how beautiful the brushed aluminium can look.


 
 Thanks for the kind words. That finish came about when I was developing the Tode guitar amp kit. I had been intrigued by some of the metal sculpture I had seen, that the artist had decorated with a flap wheel. I had also been influenced many years ago by Don Garber of Fi, who leaves his aluminum chassis amps in the raw mill finish, feeling it is a very "honest" looking finish. The grained finish process we had been having put on our panels for years had been passed from one finisher to another and the quality had become disappointingly inconsistent.
  
 We made up a couple of test panels and I had one glass bead blasted, the other I tackled with a wire brush. When we compared them I thought the random brushing was far more interesting to look at. And so it now goes on all of our aluminum panels. The only downside is that I seem to be the only guy who understands the angle to hold the rotating brush at to get the particular look I want. Thus I brush every single panel that goes out of here myself. Hundreds every year. I tend to do them in batches of 5 to 20, as the process is kind of tiring on my old back.


----------



## Jeb Listens

Being quite vain about my equipment it was the clean and restrained look of the Crack that attracted me to it even before I remotely knew what it was, let alone that I would probably need to build it myself!
  
 For me its one of the best looking amps out there, which always blows my mind given the price and that it is simple enough that many skill levels are able to build it.  I think some of the most attractive & enduring designs often come partly from a need for simplicity.   
  
 When my Dad came round last night you should have seen the look on his face when I told him I built it myself.  It still surprises me too since I have no prior electrical experience - but I received lots of great help & encouragement over on the BH forum. 
  
 My other headphone rig uses the LCD-2s but right now the 650s/Crack are seeing all the action.  I've been rolling a few tubes. Very impressed with the Russian 6H13C - wide, clear and has plenty of guts.  Perhaps not as forgiving or warm as some of the others but the top is extremely well extended and the bass is tighter & more well defined.   It has its own brand of extra sweetness & sparkle.   I always seem to love Soviet tubes.    
  
 Listening to Paul Simon - Rhythm Of The Saints  as I type this ....sounds wow, beautiful! Very easy to just get lost in it all. 
  
  
 Yours Sincerely,
  
 Jeb - another UK Crack Addict.  
  
  
  

  
  
 .


----------



## masterfuu

Got the crack from another headfier recently beautiful amp with amazing power and tonal clarity. Truly amazing value drives HD800 and T1 (v2) like dream come true. I plan on keeping this baby for a long time.


----------



## imadeadkat

I cant believe I've missed this, Now I must re-evaluate my Head system. Thanks for the work here


----------



## cspirou

There's currently a deal on the bottlehead crack where you can add on the Speedball upgrade for $20. Deal is good until Sept 17th.


----------



## ZoNtO

cspirou said:


> There's currently a deal on the bottlehead crack where you can add on the Speedball upgrade for $20. Deal is good until Sept 17th.


 
 For those of us that are not handy with a soldering iron, does anybody here offer to build the kit and ship it off for a fee?


----------



## Mich4lle

zonto said:


> For those of us that are not handy with a soldering iron, does anybody here offer to build the kit and ship it off for a fee?




I would really enjoy building another crack, but the South African post is really slow, so transport will take awhile.


----------



## cspirou

zonto said:


> For those of us that are not handy with a soldering iron, does anybody here offer to build the kit and ship it off for a fee?


 

 If you visit the bottlehead forum they have someone that will build the Crack for a fee. I would do it but I live in France and it might cost too much for shipping back and forth.


----------



## ZoNtO

cspirou said:


> If you visit the bottlehead forum they have someone that will build the Crack for a fee. I would do it but I live in France and it might cost too much for shipping back and forth.


 
 Looks like they charge $250 for the service. Not worth it at that point.


----------



## Armaegis

zonto said:


> Looks like they charge $250 for the service. Not worth it at that point.


 
  
 It's not all that unreasonable, considering how many hours it takes to build.


----------



## ZoNtO

armaegis said:


> It's not all that unreasonable, considering how many hours it takes to build.


 
 Agreed. Don't believe it's unreasonable at all, just don't think it's worth it considering other pre-built options (that look better) in the same price range. I'll poach the FS forums for one of these maybe.


----------



## adydula

PM sent on the build...
  
 Alex


----------



## JamesBr

armaegis said:


> It's not all that unreasonable, considering how many hours it takes to build.


 
 True!


----------



## brokensound

Any local builder / trouble shooters in the LA area? I'm getting a low hum noise once I installed the speedball. I probably did something wrong. I keep saying I'd take the time to trouble shoot, but my schedule is only getting worse with school. If someone can point me to a reputable local builder, I'd be extremely grateful.


----------



## Mahdi8

Check if any of your input to speedball connect to ground. If yes maybe you accidentally connect the audio path with ground somewhere


----------



## JamieMcC

brokensound said:


> Any local builder / trouble shooters in the LA area? I'm getting a low hum noise once I installed the speedball. I probably did something wrong. I keep saying I'd take the time to trouble shoot, but my schedule is only getting worse with school. If someone can point me to a reputable local builder, I'd be extremely grateful.


 
  
 Have you any other 12au7 to try as with the speedball I found my Crack to be a more sensitive in picking up noise from my12au7's. I had a handful for rolling that where all nice and quiet pre Speedball. After its installation a couple of them now had noticeable low level noise present which would disappear when a different tube was used.


----------



## adydula

I recently obtained (5) 5963 NOS tubes that have USN CHS 5963 Made in USA Sylvania with the number 902 vertically off to the right side of the tube lettering with a smaller "vdh" lettering beneath it. 
  
 I have several other 5963's but they are not the USN type...
  
 I have been going thru the 5 USN's and have many other 12AU7 variants and hae found then very good tubes and sound really great.
  
 Out of the five tubes there is one that stands out amongst the others, dramatically!
  
 Its dramatically better all around like its on steroids! Very three dimensional and transparent....one of my tests of a good tube setup is listening t it over several days and does it have that "subjective" wow experience each time or does it become a normal sounding tube?
  
 This one USN 5963 is one that is exceptional!!
  
 I need to get a tube tester to see if there is any correlation to this one tube to the other 4 in the group?
  
 Alex


----------



## Jeb Listens

> Originally Posted by *adydula* /img/forum/go_quote.gif
> 
> [........]
> 
> ...


 
  
 Alex - interesting stuff.  Just goes to show how much variation there can be not just across different brands, years and constructions but also even within a cross-section of tubes that might appear to be the same! 
  
 Does the best one look exactly the same internally and did the seller say they were all tested at NOS levels?
  
 Testing them yourself would be interesting.  I wonder if the best one is just very well balanced and would test very well so produce better sonic results, or perhaps the others are on their last legs ?   
  
 I'd love to have a tube-tester and may think about it one day.  I think it would be a lot of fun learning to get to grips with it as well as pretty useful for buying and re-selling tubes.  Unfortunately most that are available seem as though they would require some restoration work and calibration which would most likely be beyond me but i'm sure not a problem with your electrical know-how. 
  
 Anyway, keep us posted with your findings on the super-tube! 
  
 Jeb


----------



## JustinBieber

Is there any modifications to adjust the gain? With an HD800 I can't get above 9 o' clock on the volume pot, and that's with crazy 5.1 SACD ridiculous dynamic range stuff. Most of my music just barely gets out of the zone where the channel imbalance is.
  
I'm also wondering if it's my tubes. I'm not sure if a 6AS7G has more gain than the stock 6080.
  
 Nvm just found a solution.


----------



## Mich4lle

Damn,I was about to reply and tell you to just upgrade your volume pot with an Alps Blue velvet pot, apparently it sorts out the channel imbalance and it is pretty cheap. (20 dollars)
 But if you found a solution I am glad.


----------



## JamieMcC

A couple of 30 cent resistors soldered in line with rca inputs used to be in the Crack sticky section on the BHF as a option to cure the channel imbalance and have greater range on the stock pot this has since changed to the method below taken from the Crack FAQ section
  
  *3.  I can barely turn my Crack up at all before it's far too loud, what do I do?*

 Disconnect the white wire at the pot that originated at the left RCA jack.  Install a 75K resistor between this wire and where it connected on the pot. 
 Repeat this step for the red wire coming from the right RCA jack.
 Attach and solder one 33K resistor between each outer pair of lugs on each level of the volume pot.
 Resistor wattage is unimportant, 1/10 Watt or greater will work nicely.


----------



## adydula

I did that mod, and for the most part it works ok...Some music depending on the replay gain still dont allow for much volume know travel or movement....you can add another set of like resistors in parallel to the ones mentioned in the mod (the 33K's). to make this even better.
  
 on the super tube...I looked at all 5 of them in the lot and they are pretty much the same in construction, size and shape, color of internals....so thats not it.
  
 Ha..it still could be a subjective reaction here at the listeners brain!! (mine...lol).
  
 Here are the ratings from the seller:
 dont have data for tube 5 in the lot.
  
 Up for consideration is 5PC's of NOS CHS 5963 from a bulk pack with D getters and long plates...basically identical to Sylvania Gold Brand Vacuum Tubes .
 typical New on my Hickok 6000 tester is 2200/2200
 tube 1.........2600/2300
 tube 2.........2200/2100
 tube 3.........2650/2750
 tube 4.........2600/2400
  
 Alex


----------



## larcenasb

I just have to say if anyone is on the fence about the Speedball upgrade, I think it's an absolute must. The stock Crack sounds good, but the Speedball makes my music thoroughly engaging -- bass is solid and palpable, highs shiver the spine with elegance, the music just grabs you now with meaty and fierce yet graceful paws ...hahaha, all I know is it's 2:08am and I can't stop listening


----------



## i luvmusic 2

I had my modded crack for a year i thought i love the sound of it until few weeks ago my site office was hit by a lighting zapping everything plug into the AC outlet including my modded crack.
 Now that i have a stock crack for me i prefer the stock sound i do not missed the sound of my modded crack.


----------



## moriez

HoOoly Crack!
  
 Currently I have a T1 on loan and listening to it simply has me some butterflies fluttering! This seriously shifts my previous opinion on the Beyer for being too cold, analytical and spikey. The DAC changed to a X-Sabre and must have a lot to do with it. Tubes are TS 5998 and a CBS Hytron in the front seat. Trying the Cleartop tomorrow.
  
 Super enjoyable. Happy camper


----------



## JamieMcC

moriez said:


> HoOoly Crack!
> 
> Currently I have a T1 on loan and listening to it simply has me some butterflies fluttering! This seriously shifts my previous opinion on the Beyer for being too cold, analytical and spikey. The DAC changed to a X-Sabre and must have a lot to do with it. Tubes are TS 5998 and a CBS Hytron in the front seat. Trying the Cleartop tomorrow.
> 
> Super enjoyable. Happy camper


 
  
 Get yourself one of those cheap Tungsram E80cc to pair with the 5998


----------



## Dimitris

Turns out my crack is a special edition one that only takes ECC99 tubes. There were only 8 of these made. I guess I shouldn't have used 12au7 tubes as input.


----------



## moriez

jamiemcc said:


> Get yourself one of those cheap Tungsram E80cc to pair with the 5998


 
  
 I kept the one I offered a few pages back. To my ears and with my setup it made a very noticeable difference compared to the 5814A. The Tungsram suffocated the T1 and pushes the more or less neutral and open presentation into introverted and closed. Not good. Not good at all.
  
 Any experience with a RFT ECC82?


----------



## JamieMcC

moriez said:


> I kept the one I offered a few pages back. To my ears and with my setup it made a very noticeable difference compared to the 5814A. The Tungsram suffocated the T1 and pushes the more or less neutral and open presentation into introverted and closed. Not good. Not good at all.
> 
> Any experience with a RFT ECC82?


 
  

 Interesting I really liked the E80cc its one of my favourite input tubes very open sound stage with excellent resolution. So quiet the opposite impression. I have tried a few different 5814A the ones I like the most were the Tung sols and Sylvania gold print
  
 I had a pair of RFT Ecc82 over a year or more ago. I cant remember any sound impressions of them but I did think they were inoffensive sounding for a inexpensive and easy to find NOS tube.I didn't hang on to them so probably didn't suit me and I think I was using the HD650 at the time.


----------



## larcenasb

This is my third Crack build, it really lives up to the name, haha. I just love the simplicity of, and tube compliment with, this amp. Such a great value and so rewarding to build. Cheers to everyone else enjoying their music -- especially late into the nights as I am right now!


----------



## moriez

jamiemcc said:


> Interesting I really liked the E80cc its one of my favourite input tubes very open sound stage with excellent resolution. So quiet the opposite impression. I have tried a few different 5814A the ones I like the most were the Tung sols and Sylvania gold print
> 
> I had a pair of RFT Ecc82 over a year or more ago. I cant remember any sound impressions of them but I did think they were inoffensive sounding for a inexpensive and easy to find NOS tube.I didn't hang on to them so probably didn't suit me and I think I was using the HD650 at the time.


 
  
 Yeah, that's Head-Fi for ya right?
  
 Just between the two of us only there's already so many factors at play. For instance, who knows my tube is at the end of its life, our Cracks differ in components, our hearing and preferences, the rest of our setup. Forget about it! 
	

	
	
		
		

		
		
	


	




 
  
 It's that I Googled around and found a favourable comment about the RFT as compared to a Hytron. Bought one for €20 shipped this morning. Didn't like the Cleartop with the T1 and 5998 by the way. Made the upper treble unpleasantly present.


----------



## JamieMcC

moriez said:


> Yeah, that's Head-Fi for ya right?
> 
> Just between the two of us only there's already so many factors at play. For instance, who knows my tube is at the end of its life, our Cracks differ in components, our hearing and preferences, the rest of our setup. Forget about it!
> 
> ...


 

 One thing I have noticed that's has remained consistent for me through rolling different input tubes with the Crack is I tend to prefer tubes with foil getters. Please don't ask me why because I really don't know the!
  
  


larcenasb said:


> This is my third Crack build, it really lives up to the name, haha. I just love the simplicity of, and tube compliment with, this amp. Such a great value and so rewarding to build. Cheers to everyone else enjoying their music -- especially late into the nights as I am right now!


 
  
 Man I wish I could take such good pictures how did you capture the purple glow in the tube? Are those signal caps electrolytics or pio?
 I always though bypassing the last electrolytic in the power supply was worth while as well. But the a superb mod to the power supply has to be but replacing the last cement resistor with a C7X choke and last electrolytic with a film cap which I thought brought a significant improvement. 
  
 Nice build


----------



## krikor

Gotta say, my workday has been much more enjoyable the past few weeks since I moved the Crack to my office. Just wasn't listening to it enough (or ever) at home. Been having a blast bounding through a drawer full of 12au7 tubes, a couple of different output tubes and a few cans. Though not sure it has helped my productivity all that much 
	

	
	
		
		

		
		
	


	



  
*Crack is Fun!* (need a Bottlehead shirt with that on it).


----------



## i luvmusic 2

krikor said:


> Gotta say, my workday has been much more enjoyable the past few weeks since I moved the Crack to my office. Just wasn't listening to it enough (or ever) at home. Been having a blast bounding through a drawer full of 12au7 tubes, a couple of different output tubes and a few cans. Though not sure it has helped my productivity all that much
> 
> 
> 
> ...


 
 I did the same took mine into the construction site trailer so i can used it instead of collecting dust at home(I'am away from home weeks/months at a time contractor's life)until my trailer was hit by a lightning


----------



## larcenasb

Thanks JamieMcC.  To capture the purple glow, I couldn't add too much light externally (all I used was a clip-on reading light a few feet away), so I had to shoot with my lens wide open at f/1.8 and leave the shutter open for one second to let in a good amount of light.
  
 And the signal caps are indeed electrolytics. I was weighing the pros and cons of buying Dayton 100uF 250Vs @ $30/piece (not too outrageous) or the vintage Mallory electrolytics @ $12/pr. But fives times the price -- and impressions on film caps that seemed unsure and minimal -- were my reasons for choosing the electrolytics. Most people seem to say film caps tame harsh/grainy treble a bit, but my AKG K240 Sextetts coupled with the GB6080 Sylvania don't sound harsh or grainy at all. 
  
 I really am intrigued by the choke idea, thank you! I just hunted down your past posts on the subject. The last cement resistor is the one at 13L and 15L, right? And with a choke, does it matter which lead goes to which terminal? Thank you so much and take care.


----------



## ScottFW

The choke (C7X) doesn't have polarity. I also didn't find a clear best answer regarding where in the circuit to place the choke. I replaced the first resistor instead of the second (making it CLCRC instead of CRCLC) because of a few factors: 1) some vague mention on either diyaudio or some other tube amp building forum that CLCRC was preferable, 2) a post either in this thread or on the Bottlehead forum by either Doc or PJ or another Bottlehead guru whom I can't specifically recall right now saying it probably doesn't matter which of the two resistors you replace, and 3) the parts swapping & wiring is easier/shorter/straighter that way given where I've mounted the choke. I did it without drilling any extra holes in the top plate, using standoffs to replace the stock nuts on the existing screws for (IIRC) the safety ground next to the power cord inlet and one of the long transformer screws. It required slight drilling and filing to the choke's mounting tabs and "clearancing" the plastic choke bobbin to fit inside the base. Drilling new holes in the top plate would have been easier and faster, but also potentially uglier. I can take pics when I get home.
  
 Granted, I only have a few 6080 tubes (none of which are the Sylvania GB6080) and a few 6AS7 types so far, but none of them exhibit any significant purple glow in my Crack. Even in a dark room I've never noticed anything besides the filaments. Different tube types will glow differently so this could be a bit of apples-oranges here, but FWIW one of my 300Bs started glowing massively more than the other seven (in a pair of monoblock amps with 4 x 300B each) shortly before dying. Do all your tubes glow that much or just this one?


----------



## JamieMcC

larcenasb said:


> Thanks JamieMcC.  To capture the purple glow, I couldn't add too much light externally (all I used was a clip-on reading light a few feet away), so I had to shoot with my lens wide open at f/1.8 and leave the shutter open for one second to let in a good amount of light.
> 
> And the signal caps are indeed electrolytics. I was weighing the pros and cons of buying Dayton 100uF 250Vs @ $30/piece (not too outrageous) or the vintage Mallory electrolytics @ $12/pr. But fives times the price -- and impressions on film caps that seemed unsure and minimal -- were my reasons for choosing the electrolytics. Most people seem to say film caps tame harsh/grainy treble a bit, but my AKG K240 Sextetts coupled with the GB6080 Sylvania don't sound harsh or grainy at all.
> 
> I really am intrigued by the choke idea, thank you! I just hunted down your past posts on the subject. The last cement resistor is the one at 13L and 15L, right? And with a choke, does it matter which lead goes to which terminal? Thank you so much and take care.


 

 Yep you got all the requires info can be found on the BHF once a page or two in there are some pics of the parts to remove and what goes were etc. Its a easy and inexpensive mod that gives results.
  
http://bottlehead.com/smf/index.php?topic=6030.0
  
http://bottlehead.com/smf/index.php?topic=6030.0


----------



## larcenasb

jamiemcc said:


> Yep you got all the requires info can be found on the BHF once a page or two in there are some pics of the parts to remove and what goes were etc. Its a easy and inexpensive mod that gives results.
> 
> http://bottlehead.com/smf/index.php?topic=6030.0
> 
> http://bottlehead.com/smf/index.php?topic=6030.0


 
 Thanks, I'll look into it and do another pros and cons list!


----------



## Mich4lle

krikor said:


> Gotta say, my workday has been much more enjoyable the past few weeks since I moved the Crack to my office. Just wasn't listening to it enough (or ever) at home. Been having a blast bounding through a drawer full of 12au7 tubes, a couple of different output tubes and a few cans. Though not sure it has helped my productivity all that much
> 
> 
> 
> ...


 
  
 Is that a HRT musicstreamer II in the background? How is it with the Crack? Are you enjoying the combo?


----------



## adydula

I use my Crack with a ODAC Rev 1 and a HRT Music Streamer II+ and both are great, no discernible sonic differences to me at all.
  
 A.


----------



## krikor

mich4lle said:


> Is that a HRT musicstreamer II in the background? How is it with the Crack? Are you enjoying the combo?


 
 Correct. Really enjoy it with the Crack, more so than the DAC section of my Wyred mPRE. Plus it is so painless and easy to use... no nonsense approach to digital conversion, no drivers to muck around with, no power supply, easy to hide behind the equipment, etc. They don't get much fanfare, but I really respect what Kevin Halverson (formerly of Muse Electronics fame) has done with the HRT line both in terms of usability and sound quality. But full disclosure, I am a former Muse customer back when I used to run their big 300 monoblocks, matching preamp and digital converter... but that was in another audiophile life.
  
 I am really interested in trying out their higher/newer models with the Crack, but then I'm also being enticed by the new Schiit Bifrost and Gungnir multibit converters (I was fortunate to spend an afternoon with a pre-production version of the Yggdrasil via the Crack and it was VERY impressive, but a bit too much scratch for me nowadays).


----------



## krikor

adydula said:


> I use my Crack with a ODAC Rev 1 and a HRT Music Streamer II+ and both are great, no discernible sonic differences to me at all.
> 
> A.


 
 ODAC - that's another one I'm being tempted with right now. The revB is available over at massdrop at a very reasonable price, but I'm not sure it will really be much of a bump up over the HRT.


----------



## adydula

If you have the HRT your not going to hear any difference with an ODAC....I have A/B'd them side by side.....cant tell any real world difference.

Alex


----------



## reihead

Anyone using the Bottlehead OTL with the arcam irDAC? Good pairing?
 Plan to get this to use with my HD600


----------



## Maxhawk

I have an irDAC, but I use it with my main speaker rig. It replaced a Musical Fidelity M-1 which I modded by selectively upgrading some of the caps as well as all the opamps. In the end, I don't think I could tell any difference between the two. I use the M-1 with the Crack now because the amp fits nicely on top of the DAC, minimizing desk space where I use it with my computer.
  
 In my opinion, any good quality DAC pairs well. Between the cheapest $20 DAC I have versus the $700-800 irDAC & M-1, there is only a very marginal difference. Those marginal differences get swamped by changing a tube. 
  
 To answer your question, yes the irDAC pairs well, but so will most properly implemented DACs.


----------



## reihead

^^ Thank you very much, very helpful


----------



## soundfanz

Thought I'd post up a few pictures of my Crack + speedball.
  
 I had stained it black a couple of weekends ago but didn't like it too much. Started to fine sand it back, and loved the look. Finished with a couple of coats of varnish.


----------



## i luvmusic 2

^
 NICE


----------



## reihead

That's a fine looking crack!


----------



## Karlsand

Hi everyone! First post for me. I read through this whole thread a while ago which resulted in an order placed for a crack + speedball. 

I have to say, of all the beautiful builds I've seen in the thread this has to be my favourite. The wood finish is just fantastic. Well done!

I might just copy that for my build. You said you painted it black first and started sanding off. What's left of the paint looks more Brown than black to me. Anyway, might have to borrow that idea.


----------



## soundfanz

karlsand said:


> Hi everyone! First post for me. I read through this whole thread a while ago which resulted in an order placed for a crack + speedball.
> 
> I have to say, of all the beautiful builds I've seen in the thread this has to be my favourite. The wood finish is just fantastic. Well done!
> 
> I might just copy that for my build. You said you painted it black first and started sanding off. What's left of the paint looks more Brown than black to me. Anyway, might have to borrow that idea.


 
  
 I stained, not painted. Applied 3 coats. I then finely sanded it back until I was happy with the look. And finished with a coat or two of varnish.


----------



## Karlsand

Thanks Soundfanz for the clarification. That finish is right up my alley. I will try to do that with mine. If it comes out even close to the looks of yours, I'll be happy!


----------



## Karlsand

I'm bored waiting for my Crack to arrive. I'm going to buy a different pot knob. Can anyone measure the pot axis diameter for me so I can buy the right knob. Also, how big is the original knob (diameter)?

Thanks, Karl


----------



## Ankaret

Hi Crack owners. Are there any good alternatives to swapping out the stock power cable, besides the direct upgrade from Bottlehead for their nice power cable kit? And what do you think about the Bottlehead power cable upgrade for crack vs. the original vs. any alternatives that might be out there? Thanks in advance for your thoughts.
  
 I just ordered a speedball upgrade for my crack of 1.5 years and a new power tube. Thinking about upgrading the power cord too eventually.


----------



## adydula

oh gosh...IMO your wasting your dollars on power cords, but if thats your thing..there are many power cords that can be wired in. Check the Bottlehead crack forums...
  
 The speedball upgrade is well worth it.
  
  
 Alex


----------



## Rocketman248

Someday I'd like to get Bottlehead power cords for all my BH amps simply because that look cool.


----------



## JamieMcC

Replacing a resistor with a $15 choke in the power supply will give much better results than dropping $100 on a fancy power cable imho


----------



## ScottFW

I'm rocking a Monoprice right angle cord. The "upgrade" is that it lays flat instead of sticking straight up off the chassis plate.


----------



## FunyunBreath

scottfw said:


> I'm rocking a Monoprice right angle cord. The "upgrade" is that it lays flat instead of sticking straight up off the chassis plate.


 
  
 +1


----------



## lextek

funyunbreath said:


> +1



Same here. Have a right angle headphone cable and RCA adapters. The Speedball is great upgrade.


----------



## Ankaret

The laying flat rather than right out of the top would be nice. Will this work for the crack without any trouble?:
  
 http://www.monoprice.com/product?p_id=7676
  
 Does the AWG # matter for matching the right one to the crack?


----------



## adydula

I like a right angle power cable, but it has no real bearing to the actual sound quality that I am hearing....Speedball or things that muck with the circuitry have more affect on the sound that a upgrade of a power cable....nice, functional but thats about it.
  
 A.


----------



## lextek

ankaret said:


> The laying flat rather than right out of the top would be nice. Will this work for the crack without any trouble?:
> 
> http://www.monoprice.com/product?p_id=7676
> 
> Does the AWG # matter for matching the right one to the crack?



That's the on I'm using. You could always try a"better" power cord see if it sounds better to you. Remember it depends what it's plugged in to .....


----------



## Ankaret

So the AWG values don't really matter, just pick a length and go for it as far as these monoprice replacement power cables go?


----------



## adydula

Does anyone know why there are different AWG wire sizes???
  
 Why doesn't it matter with the crack?
  
 Would that power cord ever be used for another household appliance?
  
 hmmmmm..
  
 A.


----------



## daltonljj

AWG is just a measurement of how thick the wire is. The thinner the the wire the higher the resistance of the wire due to smaller cross sectional area. Most decent cords will have a awg that will meet the safety standards. So if you're asking if it will work yes it will work and it doesn't matter. But if you're asking if it matters to the sound then its a very controversial topic to discuss.


----------



## lextek

adydula said:


> Does anyone know why there are different AWG wire sizes???
> 
> Why doesn't it matter with the crack?
> 
> ...


----------



## FunyunBreath

I think that "functionally" all that really matters is that the power cord is rated for 120V and at least 10 amps.


----------



## cddc

So there is no sale this Black Friday or Cyber Monday (like the one in September or even better)? 
  
 Pretty weird given here is the biggest shopping week...


----------



## Keithpgdrb

just find a good medical grade power cord.  thats what I use.  look for the green dot.


----------



## JamieMcC

cddc said:


> So there is no sale this Black Friday or Cyber Monday (like the one in September or even better)?
> 
> Pretty weird given here is the biggest shopping week...


 
  
 Yes there is look on the Bottlehead forum for 15% off discount code


----------



## coastal1

Tempted to try the BH power cord with this discount



jamiemcc said:


> Yes there is look on the Bottlehead forum for 15% off discount code


----------



## moriez

Love bump for BH Crack.
  
 Just received the deliciously tight TS 7236 and have a Mullard CV4003 in the front. Beyerdynamic T1 hooked up. Straight romance.


----------



## FunyunBreath

moriez said:


> Love bump for BH Crack.
> 
> Just received the deliciously tight TS 7236 and have a Mullard CV4003 in the front. Beyerdynamic T1 hooked up. Straight romance.


 
  
 Very nice!
  
 I just scored an Amperex 7316 for dirt cheap on ebay last week and it's amazeballs... Sounds so good with both the 5998 and 7236.


----------



## reihead

moriez said:


> Love bump for BH Crack.
> 
> Just received the deliciously tight TS 7236 and have a Mullard CV4003 in the front. Beyerdynamic T1 hooked up. Straight romance.


 
  
  


funyunbreath said:


> Very nice!
> 
> I just scored an Amperex 7316 for dirt cheap on ebay last week and it's amazeballs... Sounds so good with both the 5998 and 7236.


 
  
  
 Care to describe the differences in SS with those tubes?
 Thanks


----------



## FunyunBreath

No problem! I haven't sold my second crack yet so I did a straight up A/B test with 2 cracks at once for you 
  

  
 I ran Cleartops in both cracks because I have a bajillion of them
  
 Highs:
 Listening first to the EQ differences between both tubes the 7236 emphasizes the highs a bit more, though at the cost of some sibilance at times. The highs on the 7236 are slightly more detailed and extend more but the 5998's are sweeter for sure. 
  
 Mids:
 7236 is more forward in the mix but thinner sounding. The 5998's mids have more substance but are slightly recessed in the mix. I'd say in general the 7236 has more separation in the midrange. Listening to Home Free and Pentatonix I can more easily pick out each singers voice at all times with the 7236. However the 5998 wins hands down when it comes to realism. Listening to Loose Duck by Wynton Marsalis the strikes on the piano keys in the beginning just have an energy and realism that isn't present on the 7236.
  
 Lows:
 The lows are definitely the point where both tubes really differ drastically. The 7236 lows are faster and more controlled, but don't go nearly to the depths that the 5998s low end does. The lows on the 5998 just puts a chill down your spine 
  
 Soundstage:
 Vocals and bass seem pretty smack dab in the center of your head on the 7236, whereas the 5998 has more height/depth. Things seem "around your head" on the 5998 and on the 7236 things are in the center and on the sides (if that makes any sense)
  
 Imaging:
 This is where the 7236 wins hand down. Listening to Amber Rubarths binaural album "Sessions from the 17th Ward" instruments are so well placed and 3D with the 7236


----------



## moriez

Or, since I couldn't begin to try giving you a detailed report like FB did, in my own few words:
  
 TS 7236 gives me a quite noticeable tighter, leaner and more impactful presentation with a more lit up top end. It indeed has the disadvantage of more sibilance and comes off as slightly less warm compared to TS 5998. After a little back and forth the TS 5998 has only slightly more bass presence to my ears and I think I'm going to prefer it most of the time over 7236. Both very nice to try out.


----------



## reihead

Thank you very much for sharing your impressions, golden information given that you have two cracks to properly A/B test.
  
 2016 will be the year I venture to play with a few tubes.


----------



## coastal1

I've been happily using the TS 5998 but may need to try the TS 7236, happy to see they're relatively reasonably priced at <$50


----------



## mitchmalibu

Hey guys,
  
 I've stumbled across a site that sells tubes in my country. Could anyone help me find out if there is anything worth getting on there ?
  
 http://www.audiophonics.fr/fr/tubes-lampes-c-533.html
  
 Much appreciated !


----------



## FunyunBreath

reihead said:


> Thank you very much for sharing your impressions, golden information given that you have two cracks to properly A/B test.
> 
> 2016 will be the year I venture to play with a few tubes.


 
  
 No problem! It's been fun having 2 cracks and I've been meaning to do a serious test between both tubes 
  
  


coastal1 said:


> I've been happily using the TS 5998 but may need to try the TS 7236, happy to see they're relatively reasonably priced at <$50


 
  
 For the prices the 5998 is commanding these days the 7236 is a really great deal. Especially since  neither are really better than the other in my opinion, they trade blows back and forth.


----------



## FunyunBreath

mitchmalibu said:


> Hey guys,
> 
> I've stumbled across a site that sells tubes in my country. Could anyone help me find out if there is anything worth getting on there ?
> 
> ...


 
  
 Looks like most of this stuff is reissued tubes, not actual vintage so I wouldn't order anything. There's great deals on ebay as long as you buy from reputable sellers.


----------



## nykobing

mitchmalibu said:


> Hey guys,
> 
> I've stumbled across a site that sells tubes in my country. Could anyone help me find out if there is anything worth getting on there ?
> 
> ...


 
 I've bought all his good stuff and I am done with 12au7/ecc82.6189/5814 etc, but this guy has amazing prices for you -
  
 http://www.ebay.fr/usr/tsf54000
  
 I got a Mazda silver plate  12au7wa for about 6 euros and a few Cifte/Belvu 6189s for the same price. You can even get great prices on Dutch tubes from him/her.


----------



## mitchmalibu

I will check him out. Thanks for your input guys.


----------



## i luvmusic 2

^^^^
 Once you check him out let us know how it goes.


----------



## mitchmalibu

I was sure that sounded weird when I clicked submit. Wasn't wrong


----------



## reihead

Specially with that avatar


----------



## Walderstorn

If u guys know any1 that lives in europe and wants to sell his...


----------



## tian105

Really looking hard to find one used.. But they all seem to come and go very quickly.


----------



## FunyunBreath

I have one to sell, I'll put the listing up later today and shoot you a pm


----------



## BohanYe

I got one coming next week, cannot wait to put this baby together.


----------



## BrettMatthews

I recently purchased one that the previous owner was unable to figure out initially and didn't have time to continue trouble shooting. Should have a chance to get started working on it next week. Then I will need to install the Speedball. Hopefully all goes well, I'm excited to see the difference between this and my O2 on my HD600.


----------



## Walderstorn

brettmatthews said:


> I recently purchased one that the previous owner was unable to figure out initially and didn't have time to continue trouble shooting. Should have a chance to get started working on it next week. Then I will need to install the Speedball. Hopefully all goes well, I'm excited to see the difference between this and my O2 on my HD600.


 
 Oh so u r the one who bought it, im actually curious to know what he did wrong.


----------



## BrettMatthews

walderstorn said:


> Oh so u r the one who bought it, im actually curious to know what he did wrong.




So far I have found a couple small things, but out off respect to the previous owner I probably won't say too much. Also I do have a degree in electronics engineering so that has helped me finding these potential issues (still need to get a 110 to 220v transformer to power the unit so I can test it thoug).

On that note, any chance anybody out there has a 110v transformer that they would be looking to trade for a brand new (spare) 220v transformer?


----------



## i luvmusic 2

Or you can get cheap step up transformer from active surplus last time i was there they have one for $30.


----------



## BrettMatthews

i luvmusic 2 said:


> Or you can get cheap step up transformer from active surplus last time i was there they have one for $30.




I have found a set up transformer that would work but ideally I would rather not need to use that and just have the proper sized internal transformer.


----------



## Walderstorn

brettmatthews said:


> So far I have found a couple small things, but out off respect to the previous owner I probably won't say too much. Also I do have a degree in electronics engineering so that has helped me finding these potential issues (still need to get a 110 to 220v transformer to power the unit so I can test it thoug).
> 
> On that note, any chance anybody out there has a 110v transformer that they would be looking to trade for a brand new (spare) 220v transformer?


 
  
 I understand, still i want to know what he shortted  for knowledge purposes eheh
  
 Keep us posted with the troubleshooting it can help ppl.


----------



## BrettMatthews

walderstorn said:


> I understand, still i want to know what he shortted  for knowledge purposes eheh
> 
> Keep us posted with the troubleshooting it can help ppl.




I believe I have found one wire going to the wrong spot and potentially some cold solder joints. Haven't had a real chance to work on it yet though so that's just from a quick first look and isn't for sure the issue.


----------



## i luvmusic 2

If you have the manual i think it is best to just redo the whole wiring.


----------



## BrettMatthews

i luvmusic 2 said:


> If you have the manual i think it is best to just redo the whole wiring.


 
 Yeah, that's what I have been doing, going through set by set inspecting so far. Then when I actually sit down to work on it I am going to go through and re-solder and check all the connections.


----------



## i luvmusic 2

brettmatthews said:


> i luvmusic 2 said:
> 
> 
> > If you have the manual i think it is best to just redo the whole wiring.
> ...


 
 Have fun and best of luck!


----------



## BrettMatthews

Well I got my Bottlehead crack working today, so far its awesome! I've only heard it so far with my work setup, line out on my Fiio E10 into the Crack and then into my DT770 250ohm and it was a big difference compared to just the E10. Looking forward to hearing my HD600 on this!
  
 So as far as things that were wrong, the power transformer was shot, once I had what I needed to power it (Euro style power cable and step-up transformer), and fixed the major issues (being the red wire off the transformer terminal 9 going to terminal 20 instead of 19, and the power resistor that goes across the PTU one side wasn't soldered on), I did the resistance checks and they were all good, so I powered it on and the PTU started smoking. So luckily a second one was included, so I swapped that out, in the process I changed quite a few of the wires, mostly to clean up how it looks, re-touched all the solder joints, then I redid the resistance checks and they looked good, powered it up, no smoke, voltage checks were good, checked the audio and all was good!
  
 For future reference if you are going to use a step-up or step-down transformer (I am in Canada (110V)and using a 220v Crack) I recommend going with a 200W transformer even thought the amp only draws about 40W. The first one I had was 100W and I'm not sure if it was a problem with the unit or not enough power, but I switched over to the 200W and it has been working well so far.
  
 Going to leave it stock for a little while then install the speedball addon (already have it) so I can see what kind of difference I hear.


----------



## Tom-s

Since crack is all about modding. Did anyone change the powersupply filter tot dual mono? And so converting the crack to a pseudo dual mono amp?


----------



## NightFlight

I'm going to say no. But I know people have cleaned it up with Cree rectifiers.


----------



## Walderstorn

brettmatthews said:


> Well I got my Bottlehead crack working today, so far its awesome! I've only heard it so far with my work setup, line out on my Fiio E10 into the Crack and then into my DT770 250ohm and it was a big difference compared to just the E10. Looking forward to hearing my HD600 on this!
> 
> So as far as things that were wrong, the power transformer was shot, once I had what I needed to power it (Euro style power cable and step-up transformer), and fixed the major issues (being the red wire off the transformer terminal 9 going to terminal 20 instead of 19, and the power resistor that goes across the PTU one side wasn't soldered on), I did the resistance checks and they were all good, so I powered it on and the PTU started smoking. So luckily a second one was included, so I swapped that out, in the process I changed quite a few of the wires, mostly to clean up how it looks, re-touched all the solder joints, then I redid the resistance checks and they looked good, powered it up, no smoke, voltage checks were good, checked the audio and all was good!
> 
> ...


 
  
 Why didnt u buy from bottlehead? Got it much cheaper? Wondering since its a 220.


----------



## BrettMatthews

walderstorn said:


> Why didnt u buy from bottlehead? Got it much cheaper? Wondering since its a 220.




Yeah I got it for a bit over half the cost.


----------



## Tom-s

nightflight said:


> I'm going to say no. But I know people have cleaned it up with Cree rectifiers.


 
 Yeah i used those already. And used a pair of triad c-7x chokes to get CLCLC. Was now thinking of making it a dual CLCRC power supply filter. Since the chokes allow me to use lower capacitance caps for the same results. If someone did this already, please let us know how it affected the sound quality. Otherwise i'm just changing the caps for bigger caps 1 + 2 and one 220uf film cap for the last one.


----------



## Walderstorn

brettmatthews said:


> Yeah I got it for a bit over half the cost.


 
  
 Gotcha, so maybe u will find a almost broken Crack down the road anduse the 110v transf ^^.


----------



## BrettMatthews

walderstorn said:


> Gotcha, so maybe u will find a almost broken Crack down the road anduse the 110v transf ^^.




That would definitely be ideal! The cost to buy a new power transformer was just too high when I already had a spare 220v one and the step up transformer was a third of the cost, but ideally I would like to switch to a 110v at some point. 

So if anyone ever wants to trade a 110v ptu for a 220v ptu let me know!


----------



## Walderstorn

brettmatthews said:


> That would definitely be ideal! The cost to buy a new power transformer was just too high when I already had a spare 220v one and the step up transformer was a third of the cost, but ideally I would like to switch to a 110v at some point.
> 
> So if anyone ever wants to trade a 110v ptu for a 220v ptu let me know!


 
 Oh y didnt even thought of that, some1 may be willing trade, u should try that. Good luck.


----------



## moriez

Any ''Crackatwoa'' builds yet? This thing got me curious.


----------



## chuckwheat

I just ordered a bottlehead crack and speedball tonight!


----------



## Tonequest

chuckwheat said:


> I just ordered a bottlehead crack and speedball tonight!


 

 Great! Keep us posted on how it sounds and what headphones you'll use with it!


----------



## chuckwheat

tonequest said:


> Great! Keep us posted on how it sounds and what headphones you'll use with it!


 
 It will definitely be with the hd650. I was specifically looking for a inexpensive but good match for them. The few bottleheads I listened to sounded pretty good with them.


----------



## Jimmy24

chuckwheat said:


> It will definitely be with the hd650. I was specifically looking for a inexpensive but good match for them. The few bottleheads I listened to sounded pretty good with them.


 
  
 I remember the first time I bought the Crack. Still use it today. Now it's all suped up and sounding incredible with the HD650's. You'll love it chuckwheat!


----------



## chuckwheat

jimbo24 said:


> I remember the first time I bought the Crack. Still use it today. Now it's all suped up and sounding incredible with the HD650's. You'll love it chuckwheat!


 
 Sweet. What sort of tubes do you use with it?


----------



## Jimmy24

chuckwheat said:


> Sweet. What sort of tubes do you use with it?


 
 I've been happy with my Tung Sol 5998's paired with a Siemen 5814a. I would say the CBS Hytron 5814a Flat Black Plates are up to bar with the Siemen's. If you like acoustic music the 5998's are perfect for it.


----------



## chuckwheat

So it has been a few days since I ordered. I know it says 3-6 weeks, but does it really take that long to ship?


----------



## Jimmy24

chuckwheat said:


> So it has been a few days since I ordered. I know it says 3-6 weeks, but does it really take that long to ship?


 
  
 Yes. The same thing happened to me when I ordered mine. From my understanding they do not have all the parts available to ship so they need to order them. I think it took at least a month before I got mine but it was well worth the wait


----------



## chuckwheat

jimbo24 said:


> Yes. The same thing happened to me when I ordered mine. From my understanding they do not have all the parts available to ship so they need to order them. I think it took at least a month before I got mine but it was well worth the wait


 Wow. I wish I knew about that before I ordered. I would think they would have at least some stock...


----------



## Jimmy24

chuckwheat said:


> Wow. I wish I knew about that before I ordered. I would think they would have at least some stock...


 
 I know how you feel. I wish I got mine faster but that's the way it goes.


----------



## daltonljj

chuckwheat said:


> Wow. I wish I knew about that before I ordered. I would think they would have at least some stock...


 
  
 Its worth the wait really. At its price point i doubt you can find anything better than it. Of course you need to fix it up properly too which i trust you can. Hook up a pair of high impedance headphones and you're good to go.


----------



## drizek

Guys, my Bottlehead has been sitting in the closet for over a year now. It worked okay for the first year I had it, without speedball, although I did have some issues with microphonics. Last year I decided to install the speedball upgrade though and I messed something up during the installation that I was never able to troubleshoot on my own. My voltage readings at the end of the installation were very wrong on one of the channels, and I never actually powered it on afterwards. 
  
 Is this a good place to ask for technical help? Should I go to Bottlehead directly?


----------



## daltonljj

You can post your questions here. Alternatively you can always go to bottlehead forum itself. More likely to get a response there faster.


----------



## JamieMcC

drizek said:


> Guys, my Bottlehead has been sitting in the closet for over a year now. It worked okay for the first year I had it, without speedball, although I did have some issues with microphonics. Last year I decided to install the speedball upgrade though and I messed something up during the installation that I was never able to troubleshoot on my own. My voltage readings at the end of the installation were very wrong on one of the channels, and I never actually powered it on afterwards.
> 
> Is this a good place to ask for technical help? Should I go to Bottlehead directly?


 

 Using the Bottlehead forum for trouble shooting it will be much quicker and by creating a new post in the Crack section you will be able to reference all reply's in order in one place with out having to trawl backwards and forwards through posts here.
  
 If you post your voltage readings and if you are able a few photos it will help speed things up.


----------



## adydula

Go to Bottlehead!!!
  
 A.


----------



## platinumbird

So the weirdest thing happened to me the other day... about 3 months ago, for some silly reason i was cleaning around my crack, and I had a look underneath with the power attached (switched off) and electrocuted myself  it was just a little shock, nothing crazy . After that, only the right channel was working. I'm in Australia so shipping to US wasn't really and option for repair, and im not very technical when it comes to repairing electronics, so its been sitting in a cupboard for this time because i haven't been able to fix it.
  
 So I get upgraditis again, dust it off so i plug in my HD650s and NOW ITS WORKING without me doing anything.
  
 What the hell?  I could've been enjoying this sound for the last 3 months. Was it a capacitor that discharged? or The tubes?
  
 Im scared if I move it it might happen again.
  
 Just got Tidal too..god damn ive missed this sound!


----------



## grausch

platinumbird said:


> So the weirdest thing happened to me the other day... about 3 months ago, for some silly reason i was cleaning around my crack, and I had a look underneath with the power attached (switched off) and electrocuted myself  it was just a little shock, nothing crazy . After that, only the right channel was working. I'm in Australia so shipping to US wasn't really and option for repair, and im not very technical when it comes to repairing electronics, so its been sitting in a cupboard for this time because i haven't been able to fix it.
> 
> So I get upgraditis again, dust it off so i plug in my HD650s and NOW ITS WORKING without me doing anything.
> 
> ...


 
 Even if you switch off your power at the wall, I believe it only switches off live (could be neutral - I can never remember). Thus, as long as the Crack is plugged in you run the risk of being shocked. The only way to avoid that risk is to a) unplug the Crack completely, b) switch the power off at the circuit breaker or c) don't touch any exposed wires when touching the Crack "down under". The shock you experience would not have been capacitors discharging nor would it have been from the tubes. When you touched the exposed wires, you simply grounded the electricity coming in from the wall and got shocked.
  
 Not sure why only one channel worked after that incident. I have been shocked the same way you were once or twice and I have been shocked once from the caps discharging when I touched them immediately after unplugging the power from the wall. My Crack worked fine thereafter although it took me some time to recover - it was less than 3 months though . I am assuming you have a bad solder joint somewhere that is now making proper contact again.


----------



## platinumbird

grausch said:


> Even if you switch off your power at the wall, I believe it only switches off live (could be neutral - I can never remember). Thus, as long as the Crack is plugged in you run the risk of being shocked. The only way to avoid that risk is to a) unplug the Crack completely, b) switch the power off at the circuit breaker or c) don't touch any exposed wires when touching the Crack "down under". The shock you experience would not have been capacitors discharging nor would it have been from the tubes. When you touched the exposed wires, you simply grounded the electricity coming in from the wall and got shocked.
> 
> Not sure why only one channel worked after that incident. I have been shocked the same way you were once or twice and I have been shocked once from the caps discharging when I touched them immediately after unplugging the power from the wall. My Crack worked fine thereafter although it took me some time to recover - it was less than 3 months though . I am assuming you have a bad solder joint somewhere that is now making proper contact again.


 
 It's such a freaky feeling >.< 
  
 Anyway now there is constant hiss more on the left channel than the right, i have a feeling it may be dust and or that bad solder joint, or maybe tubes? Ugh wish i was in the US would just send it back to bottlehead to redo it for me, lol


----------



## grausch

platinumbird said:


> It's such a freaky feeling >.<
> 
> Anyway now there is constant hiss more on the left channel than the right, i have a feeling it may be dust and or that bad solder joint, or maybe tubes? Ugh wish i was in the US would just send it back to bottlehead to redo it for me, lol


 
 Yes, being shocked by electricity is no fun and realising how I stupid I was even less. Being shocked from the caps discharging is even worse. Before I start working on the Crack nowadays (and especially during voltage checks), I always check to ensure that the PS caps have discharged before I even start. 
  
 The best place to solve the issue would be the Bottlehead forums. Check your resistances and your voltages and post any that seem out of line there. They can help guide you through the process of fixing the problem much better than we can here.


----------



## platinumbird

grausch said:


> Yes, being shocked by electricity is no fun and realising how I stupid I was even less. Being shocked from the caps discharging is even worse. Before I start working on the Crack nowadays (and especially during voltage checks), I always check to ensure that the PS caps have discharged before I even start.
> 
> The best place to solve the issue would be the Bottlehead forums. Check your resistances and your voltages and post any that seem out of line there. They can help guide you through the process of fixing the problem much better than we can here.


 
 Just turned it over and gave it a good dusting.
  
 Now the hissing is gone, but only right channel is working  "sigh"
  
 Guess i should get out my multimeter  I have no idea wehere to start... how do i know if a solder joint is bad or not?


----------



## grausch

platinumbird said:


> Just turned it over and gave it a good dusting.
> 
> Now the hissing is gone, but only right channel is working  "sigh"
> 
> Guess i should get out my multimeter  I have no idea wehere to start... how do i know if a solder joint is bad or not?


 
 You can find bad solder joints by doing the chopstick test, namely taking a chopstick (any non-conductive object will do) and systematically giving all solder joints a push or shove. If you listen to your headphones, you will usually hear a crackling noise to indicate something is loose. I would first check resistances. If those check out, check voltages. If everything checks out at this point, you could do the chopstick test, but I would still recommend contacting the team at the Bottlehead forums before you start poking in there with the chopsticks and run the risk of further damage to your amp.


----------



## adydula

Get over to Bottlehead crack forum, post your resistnances and if ok, then post all your voltage measurements...the guys over there are "bottlehead" and will quickly respond and help you get things working correctly!!
  
 Alex


----------



## ohcrapgorillas

If one wanted to bypass the final power cap in the Crack with a film capacitor, does the actual capacitance value of the film cap matter? The only thing I could find on that mod, which I know I've seen in multiple places, was someone using a WIMA 2.2uf cap. Just curious whether or not the capacitance value matters, and what effect increasing/decreasing that value might theoretically have on the sound


----------



## ScottFW

It's fairly standard for bypass caps to be 1% of the value of the larger cap being bypassed, but that's not the only "correct" or magic value. I doubt you'd hear much difference within an order of magnitude of that range. IIRC the theory has mostly to do with resonant frequencies (which I read about a while ago and have since forgotten) and the fact that two caps in parallel will have a lower ESR than just one.
  
 I've hot-swapped a variety of bypass caps (values, as well as material/construction type) over the 100uF output coupling caps, where my naive understanding says I'd be more likely to detect audible differences than in the PS section. Even in sighted, biased tests where I had bypass caps alligator-clipped in and was disconnecting them on the fly (if anyone has a better experimental method, I'm all ears) I struggled to hear differences. With "a bypass cap" in place the highs were perhaps a touch more open and airy. Maybe. Could have been imaginary. I was working within a range of 0.1uF to 3uF (0.1% to 3% of the larger cap's value). So I wouldn't lose sleep over bypass cap value provided it has an appropriate voltage rating.


----------



## ohcrapgorillas

Speaking of those damn output caps, I just got done replacing them entirely earlier today. I put in a couple of Dayton Audio 100uF 250V polypropylene caps in their place. IMO there is a significant gain in clarity that I would recommend.


----------



## Jimmy24

ohcrapgorillas said:


> Speaking of those damn output caps, I just got done replacing them entirely earlier today. I put in a couple of Dayton Audio 100uF 250V polypropylene caps in their place. IMO there is a significant gain in clarity that I would recommend.


 
  
 Mmmm yes I got those too on my Crack. There is definitely a big change in clarity that I believe is very noticeable.


----------



## saxophone

So I was looking this up, and I found a lot of information from a few years ago. I'm sure it's still relevant, but I might as well ask again. 

I am interested in building the Crack and don't have any equipment (iron, solder etc.). With a $50 budget, what equipment would you suggest? Or do I need to extend my budget?


----------



## audiojun

$50 is enough
Soldering iron, solder, multi meter and maybe some desoldering wick for when you mess up.


----------



## Drrizzt

I just bought the legendary HD600, having a Hifiman He-500 before i'm just happy with the more accurate sound of the HD600, even though it's more polite.
  
 I used to drive my Hifiman with the Project Polaris from Garage1217 wich is a SS amp with some harmonics tube distorsion. I'm now considering to upgrade with the very renowned Crack, but i'm wondering if it's worth it considering the fact that the Polaris is already a very good amp pairing with the HD600, i have no idea of how the HD600 could improve upon such a good match with the crack...


----------



## Jimmy24

saxophone said:


> So I was looking this up, and I found a lot of information from a few years ago. I'm sure it's still relevant, but I might as well ask again.
> 
> I am interested in building the Crack and don't have any equipment (iron, solder etc.). With a $50 budget, what equipment would you suggest? Or do I need to extend my budget?


 
  
 I would also recommend a solder wire sponge. It beats having to use a paper towel after each solder. It's just more neat that way. You'll definitely need a soldering iron, solder, and either a desoldering pump (takes practice using it) or desoldering wick. I like using the pump better, it's just faster and easier when you get the hang of it. Not sure if $50 will cover all of it but I'm sure you can get close to around that price.


----------



## saxophone

Well, I understand that I need those items. Some people suggested getting a soldering iron that can run 600 degrees Farenheit and others said I need an iron that can run 600 degrees Celsius. That's a pretty big difference, and I still haven't figured out which one is correct, although 600 F makes a bit more sense. I didn't consider purchasing a multimeter, so I added that into the equation. I saw that soldering stations were available and a bit cheaper, but they didn't have a desoldering pump/wick.
  
 This is what I have so far in my cart:


 Besides solder, are there any other things I will need? Also, do you have any suggestions on modifications to this list (brands, cheaper products available, etc.)?


----------



## daltonljj

saxophone said:


> Well, I understand that I need those items. Some people suggested getting a soldering iron that can run 600 degrees Farenheit and others said I need an iron that can run 600 degrees Celsius. That's a pretty big difference, and I still haven't figured out which one is correct, although 600 F makes a bit more sense. I didn't consider purchasing a multimeter, so I added that into the equation. I saw that soldering stations were available and a bit cheaper, but they didn't have a desoldering pump/wick.
> 
> This is what I have so far in my cart:
> 
> ...


 
  
 a long nose pliers and a cutter too. not forgetting a wire stripper this would be for the electronics component. For the wooden base you will need wood glue and some tape.


----------



## saxophone

I have a 5 inch/17.5cm wire cutter/stripper and a 5 inch/17.5cm long nose pliers. I forgot about the base. I do need wood glue and some paint.


----------



## Jimmy24

You should be good to go with those items. Let us know how it goes and good luck!


----------



## saxophone

Yeah. I probably won't be able to buy it for a month or so. I might just wait until the next speedball sale so I can get both at the same time. 

In the mean time, I'm going to solder everything.


----------



## Jimmy24

That's what I would do as well. Btw, it takes time to wait for the Crack to arrive just to let you know. Last time it took 3 to 4 weeks before I received mine. Just giving you a heads up for the wait time.


----------



## Mich4lle

Hello Funyunbreath,
  
 I saw this picture of you Crack about a year ago and was very impressed, in fact I am sure I commented on it.
 I have a question for you though, I have bought the same tube sockets with adapters and I just want to know how the are installed.
 The main part of my concern has to do with where the top and bottom wires go. If the wire went into the bottom hoop of the normal socket,
 does it go into the outside hoop on the adapter?
  
 Any help would be greatly appreciated.


----------



## Mich4lle

This is the image I was talking about.


----------



## Mich4lle

Ok so a complete disaster has befallen me. In the process of removing the sockets I broke one of the LEDs in the 9 pin socket.
 I have no idea what to replace it with, or if the crack might work without it. Can somebody please let me know what I can do about it.
 Thank you in advance for any help.


----------



## Whit3Rav3n

The amp will not work correctly without the LED. You need a HLMP-6000 as a replacement.


----------



## Mich4lle

Is that the only way, because I live in South Africa and the post is VERY slow.
 Is there not some alternative I can use that I might be able to source locally?
 If not I will just be without my Crack for a while.


----------



## JamieMcC

mich4lle said:


> Ok so a complete disaster has befallen me. In the process of removing the sockets I broke one of the LEDs in the 9 pin socket.
> I have no idea what to replace it with, or if the crack might work without it. Can somebody please let me know what I can do about it.
> Thank you in advance for any help.


 
  
 Just look for HLMP-6000 on ebay they are plenty of sellers or you can find them at electronic specialists like Mouser. I think Bottlehead are also selling spares.
  
http://www.mouser.co.uk/Search/Refine.aspx?Keyword=HLMP-6000


----------



## Mich4lle

Like I said to WhiteRaven, I live in South Africa, which has really slow post.
 I am looking for an alternative I can source locally.
 I can order it straight fro Bottlehead, or one of the Ebay retailers which are all in the UK, both options mean I will have to wait for the terrible post service.
 Thanks for the replies though.


----------



## saxophone

For those of you who have build the speedball upgrade, do you suggest building the Crack with speedball upgrade in one go or do you suggest building the Crack, testing it and then upgrading it with the speedball?


----------



## Keithpgdrb

saxophone said:


> For those of you who have build the speedball upgrade, do you suggest building the Crack with speedball upgrade in one go or do you suggest building the Crack, testing it and then upgrading it with the speedball?


Build it without first to make sure it works. Then add. Even if you buy them together.


----------



## BrettMatthews

saxophone said:


> For those of you who have build the speedball upgrade, do you suggest building the Crack with speedball upgrade in one go or do you suggest building the Crack, testing it and then upgrading it with the speedball?


 
 Definitely build them separate, you don't want to have to try to diagnose a problem with the speedball without having a solid base to start.
  
 I just finished building mine not that long ago and added the speedball even more recently. Amazing pairing with the HD600's, sounds fantastic, but sadly I am thinking of selling the pair and downgrading my setup as I just haven't had time to do much listening lately.


----------



## daltonljj

mich4lle said:


> Like I said to WhiteRaven, I live in South Africa, which has really slow post.
> I am looking for an alternative I can source locally.
> I can order it straight fro Bottlehead, or one of the Ebay retailers which are all in the UK, both options mean I will have to wait for the terrible post service.
> Thanks for the replies though.


 
  Dont think there is anyway to get around it unless you can find a local electronics store that sells the HLMP-6000. And what do you mean bu broke? The leads broke off? The leads of mine broke off last time too so what i did was i carefully soldered a short piece of bare wire wire to reconnect them. But of course i ordered fresh stocks of it to replace it. Just order 2 to 3. they are really cheap should you damage it again there will be spares.
  
  


saxophone said:


> For those of you who have build the speedball upgrade, do you suggest building the Crack with speedball upgrade in one go or do you suggest building the Crack, testing it and then upgrading it with the speedball?


 
  
 If you have some experience and know what you're doing and have studied and understand circuits before, you could built them together cos the crack isn't really a tough job. However if you don't have any prior knowledge but insist on building it together you will need to be extremely careful in following all the steps in the instruction manual cos should you do it wrongly it will be hard for you to diagnose the issue. So might be best to do it separately although it maybe a little troublesome haha.


----------



## brokensound

Are there any local builders in the So-Cal area? Everything worked before my Speedball upgrade. Now the music sounds distant and there's low volume hum. I totally would troubleshoot it, but it's been difficult to find the time between school and work.


----------



## chuckwheat

Does anyone recommend that the crack be built with the speedball immediately? I ordered them both.


----------



## grausch

chuckwheat said:


> Does anyone recommend that the crack be built with the speedball immediately? I ordered them both.


 
 No. Build the stock Crack first. If you run into any issues, the first troubleshooting step is to remove the Speedball.
  
 Only thing I would recommend is putting the standoffs in place. Inserting the standoffs after having built the Crack can be tricky. I prefer to do this in advance.
  
 Edit: It makes routing the wires around the 9-pin socket much easier. With my first build it was almost impossible to get the standoffs in place.


----------



## heliosphann

Just got a HD800 to use with my Crack w/speedball. Anyone have any input tube recommendations that excell with this pairing? I'm running a Graphite Bendix 6080WB for the power.


----------



## Maxhawk

heliosphann said:


> Just got a HD800 to use with my Crack w/speedball. Anyone have any input tube recommendations that excell with this pairing? I'm running a Graphite Bendix 6080WB for the power.


 
 With my HD800 my favorite input tube is the 5687 paired with a slotted graphite 6080WB. Unfortunately the 5687 has a different pin out and bias requirements so it's not plug and play.
  
 For a 12AU7 drop-in replacement, my favorite was the CBS-Hytron 5814.


----------



## heliosphann

maxhawk said:


> With my HD800 my favorite input tube is the 5687 paired with a slotted graphite 6080WB. Unfortunately the 5687 has a different pin out and bias requirements so it's not plug and play.
> 
> For a 12AU7 drop-in replacement, my favorite was the CBS-Hytron 5814.




Funny you say that, I was actually using a CBS-Hytron 5814 rebrand!


----------



## JamieMcC

Build the Crack stock first not only is it easier to trouble shoot but you also get to hear the difference the Speedball makes when added.
  
 When you come to fit the Speedball your only going to have remove four resistors. All four are real easy and take no time at all to install in the first place these are the two 22.1k plate load resistors and the two big 3k cement cathode resistors that are soldered together and sit below vents in Cracks top plate.
  
 If you plan ahead to allow for easy snipping of their leads its only six snips with your side cutters and your ready to install the Speedball...


----------



## Jimmy24

chuckwheat said:


> Does anyone recommend that the crack be built with the speedball immediately? I ordered them both.


 

 You might like the sound without Speedball. I think I remember liking it better w/o Speedball. It could be my ears fooling me but I think I heard better bass and clarity. Definitely would build it first w/o it like Jamie said.


----------



## Jimmy24

heliosphann said:


> Just got a HD800 to use with my Crack w/speedball. Anyone have any input tube recommendations that excell with this pairing? I'm running a Graphite Bendix 6080WB for the power.


 
  
 If you can afford it, I'd try the Siemens 5814a. I use to have the CBS Hytron 5814a but the Siemens takes it one step above.


----------



## Aeolus Kratos

Just to let you guys know, there will be a 16% discount for nearly ALL products in Bottlehead in one day only - 29th Feb. I doubt there won't be a better time to get the fantastic budget Crack amp or the marvelous Mainline amp.
  
http://bottlehead.com/smf/index.php?topic=8903.0
  
 Happy shopping!


----------



## Jason Orlando

Looking at purchasing this kit and looking for second opinions.
  
 I purchased HD700 and O2+ODAC.  I found that when plugged into the O2 the HD700 has some problems that id not seen described in much detail elsewhere on the web.  I did purchase them in large part for the comfort, but i still expect good sound quality.
  
 When plugged into the O2, they are clear, but lack bass ( around 30hz and under).  I thought the issue was the headphones -- but had a friend over with a schiit asgard, 2 (he also brought hd650 for comparison) and found that the hd700 actually have pretty good bass on that unit, and ALSO when plugged into my receiver (pioneer vsx-1124k)
  
 So now i'm a bit relieved, but looking for a replacement for my O2.  I was initially interested in the valhalla2 but now i'm looking at several amps.
  
 According to this review: http://www.headfonia.com/ls-take-on-the-sennheiser-hd700/ the bottlehead crack pairs really well with the HD700.  However this seems to conflict with the manufacturers description of this amp as being suitable for 300ohm and above.  
  
 I'm looking to roll off the highs a bit, get more warmth, and extended bass on my existing hd700 headphones.  Is this the amp for me?


----------



## Tom-s

Crack has an output impedance of 120 Ohms. This makes it a good match with headphones rated above 120 Ohms.
  
 http://bottlehead.com/smf/index.php?topic=546.0
  
 IME lower impedance headphones with low power consumption sound ok with crack.
  
 Edit: The crack is an amplifier that could work with just about every taste. There's a whole list of mod's available that help create your preferred sound.
 After that it's a matter of seasoning via rolling capacitors and tubes.


----------



## audiojun

The HD700 150 ohm is pushing it on the dampening factor between amp and headphones. Maybe a schiit valhalla instead, it has the lower output impedance so it matches with the HD 700 better.
  
 disclaimer: I never listened to the HD 700 with the Crack.


----------



## Tom-s

If this would be a problem, then there's some mod's to help this. Search the BH forum.
 - Change the 6080 for a lower impedance model (impedance could drop to only 70 ohms, 5998).
 - Up the capacitance of the output caps


----------



## chuckwheat

Oh, what might this be, I wonder...

 Well, I know what I'm doing tonight


----------



## i luvmusic 2

SEX?


----------



## Jimmy24

chuckwheat said:


> Oh, what might this be, I wonder...
> 
> Well, I know what I'm doing tonight


 
  
 Sweet man! Yours seemed to arrive sooner than mine did. Good luck on the build sir.


----------



## lextek

chuckwheat said:


> Oh, what might this be, I wonder...
> 
> 
> Well, I know what I'm doing tonight



Most fun I had was building my Crack. No wait that would be listening to it and thinking I made that.


----------



## chuckwheat

lextek said:


> Most fun I had was building my Crack. No wait that would be listening to it and thinking I made that.







jimbo24 said:


> Sweet man! Yours seemed to arrive sooner than mine did. Good luck on the build sir.





Aaaaaaand I melted the switch. Schiit.
Does anyone know if I could use a similar switch? In the instructions it offers a free replacement if you melt the switch, but I'm impatient, and shipping takes a while.


----------



## audiojun

You melted the power switch? If the metal contact parts inside are intact it could still be used. It really depends on how bad you melted it. I've melted some of the wires but it does nothing sonically.


----------



## lextek

Now we miss the local Radio Shack


----------



## audiojun

Just some advice don't rush your crack build. Do everything correctly and according to the manual, because fixing mistakes can be a hard puzzle.


----------



## lextek

Should you run som hiccups. The Bottlhead forums are great for troubleshooting help.


----------



## chuckwheat

audiojun said:


> You melted the power switch? If the metal contact parts inside are intact it could still be used. It really depends on how bad you melted it. I've melted some of the wires but it does nothing sonically.



The metal pieces don't fit back into the switch, and the switch became mushy. My multimeter found the switch no longer reliably switching... :/ I only had the iron on it for a second.


----------



## audiojun

Yeah get a new switch. You can still continue your build. You can temporary operate the crack without one, just have it always on and unplug the power cord to turn it off.


----------



## chuckwheat

audiojun said:


> Yeah get a new switch. You can still continue your build. You can temporary operate the crack without one, just have it always on and unplug the power cord to turn it off.




Too late I already finished . Resistance check passed too. I took my time and was really careful. 8 hours? Jeez
I think I'm just going to solder the switch wires together and plug/unplug like you said until I can get a replacement switch. Going to do voltage check tomorrow.
Question: How much force is normal for plugging in the tubes? I'm worried I'm going to crush them trying.


----------



## JoshMo

Don't worry about inserting tubes, they wont break in your hands. Just make sure you have the pins lined up correctly and it will take a firm push.

As for replacement switch parts - parts express, digi key, etc will carry similar switches.


----------



## JamieMcC

Bottlehead have some tutorial videos on their forum
  
http://bottlehead.com/smf/index.php?board=55.0
  
 Including
  
*How to solder the power switch without melting it ! *


----------



## chuckwheat

jamiemcc said:


> Bottlehead have some tutorial videos on their forum
> 
> http://bottlehead.com/smf/index.php?board=55.0
> 
> ...







joshmo said:


> Don't worry about inserting tubes, they wont break in your hands. Just make sure you have the pins lined up correctly and it will take a firm push.
> 
> As for replacement switch parts - parts express, digi key, etc will carry similar switches.




Voltage check passed, plugged it in, it works! The first thing I notice is that vocals are IMMENSELY clear over the magni 2U. WOW. Actually, just about everything is tighter and clearer.
I look forward to installing the speedball later on and seeing how the sound changes.
Thank you everyone for your help and advice!


Edit
The instructions mention this:
"REVISION 5/6/10: Making this wire 3” long and connecting it to Terminal 14U instead of terminal 22L may yield more quiet operation" when connecting power transformer terminal 4 to terminal 22L. Has anyone actually tried both configurations and/or recommend one or the other?

Every couple minutes or so it will make a small noise in the right channel. It is like 2-4 different tones for a second or less one after another. It sounds around 2000-5000hz. Some static will accompany it. It's very quiet, and seems to get better when it's in use for longer, but it's still a little worrying if i'm going to put the speedball into it.
I noticed that the voltage checks were within range, but always on the lower end of the range. Is that anything unusual?
Edit: I think it's related to interference from my phone, wifi, computer, etc. Putting my phone right next to it makes the noise. I'm going to try and and cover the crack with foil and see if it goes away.


----------



## audiojun

It's just a different path to the ground shouldn't matter that much.

Wait till you get the speedball in.


----------



## chuckwheat

audiojun said:


> It's just a different path to the ground shouldn't matter that much.
> 
> Wait till you get the speedball in.


 
 Is it that much better?


----------



## audiojun

Yeah the speedball is such a crucial upgrade, imo the Crack without speedball makes the Crack build not worth it. Since chinese tube amps like darkvoice/la figaro 336se/ little dot etc have near similar sonic quality at a lower price, adding the speedball makes the crack a league above them.
  
 The speedball tightens up the bass, the crack feels faster, more details and clarity and the background noise drops even lower with the speedball installed.


----------



## JoshMo

Agree that speedball makes a big difference, but the one that really floored me was upgrading the output caps to some mundorfs. I felt the SB upgrade improved clarity at the expense of the warm tube sound. I feel upgrading caps made the bass return, tightened it up and was overall a warmer but still detailed OTL. Not a inexpensive upgrade, like swapping out the pot, but imo worth the price of admission.


----------



## Jimmy24

I agree with JoshMo about the difference in sound you will get by upgrading the output caps. I upgraded mine with Dayton's and the difference was much more apparent than the upgrade to Speedball. I can't say if the Speedball really improved the Crack to a significant degree. I wasn't really floored when I upgraded it to be honest with you, so don't get your hopes up too high. The fun thing about the Crack is that there are so many different mods you can do after completing it which makes it unique than other amps. Definitely upgrade your output caps at some point and you will be happy that you did. Not to mention the installation is really easy.
  
 I'll post some pics of mine soon so you can see what other mods you can do with it. Right now I hope you get yours working soon so you can start enjoying it


----------



## chuckwheat

audiojun said:


> Yeah the speedball is such a crucial upgrade, imo the Crack without speedball makes the Crack build not worth it. Since chinese tube amps like darkvoice/la figaro 336se/ little dot etc have near similar sonic quality at a lower price, adding the speedball makes the crack a league above them.
> 
> The speedball tightens up the bass, the crack feels faster, more details and clarity and the background noise drops even lower with the speedball installed.



Well then, I think I know what I'm doing tonight.

I discovered that my amp pick up my neighbors wifi interference every so often. I live in a dense neighborhood. It's not so bad, but it means I probably built it correctly and I can go ahead and add the speedball. The manual even mentions the speedball would aid in reducing interference carried over the power line. So that's good


----------



## audiojun

The tubes can pick up interference. Probably your situation here.
  
 In my case, those long input wires from RCA to Pot was a source of interference for me. I was shocked when I discovered that all my noise problem was because of the power supply interfering with those long wires, though I did an half assed job of braiding them. I bought new wires and re-braided and even added aluminum foil grounded shield just to be extra secure (don't know if it helped). But now my Crack is super quiet, It's completely black at max volume.


----------



## chuckwheat

audiojun said:


> The tubes can pick up interference. Probably your situation here.
> 
> In my case, those long input wires from RCA to Pot was a source of interference for me. I was shocked when I discovered that all my noise problem was because of the power supply interfering with those long wires, though I did an half assed job of braiding them. I bought new wires and re-braided and even added aluminum foil grounded shield just to be extra secure (don't know if it helped). But now my Crack is super quiet, It's completely black at max volume.


 
 Do you have any pictures of the aluminum you wrapped around them? That seems easy enough to give a try.
 I do notice that no input and volume all the way up will cause an audible 60hz hum. I can even faintly hear it with the volume lower. Pot cable pickup makes sense...


----------



## audiojun

It was just me being nuts it might have done something or nothing at all I haven't compared it. The aluminum should make contact with the chasis because it's the ground, it makes a faraday shield, the same concept how shielded cables work the ground is wrapped around the wires that carry audio signals. This could also be done around the tubes if you are nuts about rfi.


----------



## ScottFW

chuckwheat said:


> I do notice that no input and volume all the way up will cause an audible 60hz hum. I can even faintly hear it with the volume lower. Pot cable pickup makes sense...


 
  
 Pre-Speedball mine had a barely audible 60 Hz hum at normal-to-loud listening volume. Post-Speedball, in order to hear any hum I have to crank the volume up to a point that if music was playing my eardrums would melt. It's effectively negligible.
  
 The Bottlehead guys said that at least some of the noise in Cracks is due to B+ ripple, hence the recommendations to run a choke in the PS. I can't say I noticed a huge audible difference after adding a choke, but it was already pretty darn quiet after adding the Speedball and I don't have a 'scope to measure it.
  
 For tube gear in general, AC filament supply is another possible source of 60 Hz hum, but it's not safe to convert the Crack filament supply to DC using the stock transformer. A 6V wall wart would work, but I've seen and listened to a couple of other Crack builds at local meets, all still running AC on the filaments and all had negligible hum. As long as it's nice and quiet at sane listening volumes, this isn't worth addressing IMO.
  
 Also, some of my 12AU7s are slightly noisier and/or hum a little more than others. Again, this was more of a pre-Speedball issue, but you're going to wind up swapping tubes anyway so it's an easy place to start.


----------



## bigbenrfan99

jason orlando said:


> Looking at purchasing this kit and looking for second opinions.
> 
> I purchased HD700 and O2+ODAC.  I found that when plugged into the O2 the HD700 has some problems that id not seen described in much detail elsewhere on the web.  I did purchase them in large part for the comfort, but i still expect good sound quality.
> 
> ...


 
 I don't know if you made a decision, but I'm listening to the HD700 + Crack with Speedball combo now.  It's fantastic in my opinion.  I can't really compare it to any other amp at the moment, but it is better than my memory of it with the Burson HA-160.  I don't really think the Crack will extend the bass very much, but the bass quality is excellent.  I have a hard time imagining someone describing the combo as having a "lack of bass."  I haven't encountered any sibilance so far.


----------



## chuckwheat

audiojun said:


> It was just me being nuts it might have done something or nothing at all I haven't compared it. The aluminum should make contact with the chasis because it's the ground, it makes a faraday shield, the same concept how shielded cables work the ground is wrapped around the wires that carry audio signals. This could also be done around the tubes if you are nuts about rfi.


 
  
  


scottfw said:


> Pre-Speedball mine had a barely audible 60 Hz hum at normal-to-loud listening volume. Post-Speedball, in order to hear any hum I have to crank the volume up to a point that if music was playing my eardrums would melt. It's effectively negligible.
> 
> The Bottlehead guys said that at least some of the noise in Cracks is due to B+ ripple, hence the recommendations to run a choke in the PS. I can't say I noticed a huge audible difference after adding a choke, but it was already pretty darn quiet after adding the Speedball and I don't have a 'scope to measure it.
> 
> ...


 
  
 So today I installed the speedball. Unable to get one of the standoffs in, it's kind of just hanging in by one standoff. It seems fine, but the tip of the lower heatsink will touch whatever table you set it on. I don't think it will be a problem.
 Regardless, the sound is pretty amazing. Instrument separation is amazing. I notice that the vocals might not seem so warm with the speedball vs the vanilla crack, but the clarity and super black background makes up for it. Soundstage is immense. It'll definitely take some getting used to, having used the magni 2 uber for the past year almost non-stop.
 The noise in the pot volume range is still a little bit there.
 I still hear possible RFI high pitched tone or static hum when it's quiet. The aluminum wrap around the rca wires didn't change much. It is especially so after a few minutes of running. I turn it on, and for about a minute, it's really quiet. As the tubes get hotter, it starts to pick up more background noise, humming, and ringing. It also seems to get more prone to this noise if it hasn't been playing anything for a few minutes or more. Could this mean a bad tube?
 Thanks everyone for the help 
  
 It seems I only use 10% of the potentiometer range. Has anyone replaced it with another kind of potentiometer with more resistance? Perhaps a stepped attenuator?


----------



## audiojun

Try the aluminum foil thing for the tubes as well make a shield around the glass and ground the aluminum to the chasis. I am just curious if it would help, for science!
  
 It's very likely bad tubes or the ac heater wiring or soldier joints you can go over soldier joints as well at the ac heater area, or do the chopstick test, turn the crack around while it's on (be careful it's high voltage) and poke hard (don't break it though) at the solder joints and wiggle the wires with a chopstick or a stick (non conductive) if it make the hum better or worse you'll know it's bad wires or soldier joints, listen to it with headphones.


----------



## chuckwheat

audiojun said:


> Try the aluminum foil thing for the tubes as well make a shield around the glass and ground the aluminum to the chasis. I am just curious if it would help, for science!
> 
> It's very likely bad tubes or the ac heater wiring or soldier joints you can go over soldier joints as well at the ac heater area, or do the chopstick test, turn the crack around while it's on (be careful it's high voltage) and poke hard (don't break it though) at the solder joints and wiggle the wires with a chopstick or a stick (non conductive) if it make the hum better or worse you'll know it's bad wires or soldier joints, listen to it with headphones.


 
 Thank you for helping me out with this. I'll do this "chopstick test" tomorrow. What's the AC Heater?
 I'm learning more about this background noise the more I mess with it.
 Wiggling the rectifier tube sometimes seems to either cause the noise, change the noise, or silence the noise temporarily. It seems to be pretty consistent by channel. The right channel is getting most of the noise.


----------



## grausch

chuckwheat said:


> So today I installed the speedball. Unable to get one of the standoffs in, it's kind of just hanging in by one standoff. It seems fine, but the tip of the lower heatsink will touch whatever table you set it on. I don't think it will be a problem.
> Regardless, the sound is pretty amazing. Instrument separation is amazing. I notice that the vocals might not seem so warm with the speedball vs the vanilla crack, but the clarity and super black background makes up for it. Soundstage is immense. It'll definitely take some getting used to, having used the magni 2 uber for the past year almost non-stop.
> The noise in the pot volume range is still a little bit there.
> I still hear possible RFI high pitched tone or static hum when it's quiet. The aluminum wrap around the rca wires didn't change much. It is especially so after a few minutes of running. I turn it on, and for about a minute, it's really quiet. As the tubes get hotter, it starts to pick up more background noise, humming, and ringing. It also seems to get more prone to this noise if it hasn't been playing anything for a few minutes or more. Could this mean a bad tube?
> ...


 
 A little late for this advice now for you, but perhaps others may find this helpful. I always advise installing the standoffs right at the beginning of the normal Crack build. Remove them each time you need to solder in their vicinity and then replace them. Makes cable routing a lot easier.
  
 Regarding the noise, what are you using as source? Static could be bad power from a USB port. If the static is still there if the Crack is plugged into an iPhone (or other portable device) then it could be a bad solder joint. If there is a constant hum, it could be a ground loop. Quite a few possibilities and you could try to eliminate some of them.
  
 I see you also posted on the Bottlehead forum, although there it looks like the noise decreases as the tubes get hotter. I have never had a bad tube, so don't know what the symptoms would be. Try to troubleshoot all other areas unless you really want to roll your tubes.
  
 The VA Labs attentuator gave me more usable range or you could also install some Harrison Labs 12db attentuators. Decreasing the volume from your source could also be an option.
  


chuckwheat said:


> Thank you for helping me out with this. I'll do this "chopstick test" tomorrow. What's the AC Heater?
> I'm learning more about this background noise the more I mess with it.
> Wiggling the rectifier tube sometimes seems to either cause the noise, change the noise, or silence the noise temporarily. It seems to be pretty consistent by channel. The right channel is getting most of the noise.


 
  
 If wriggling a tube causes noise, then also check the solder joints on the tube socket. You could also try and clean the tube pins and inserting and removing the tube a couple of times to try and clean the tube socket itself.


----------



## chuckwheat

grausch said:


> A little late for this advice now for you, but perhaps others may find this helpful. I always advise installing the standoffs right at the beginning of the normal Crack build. Remove them each time you need to solder in their vicinity and then replace them. Makes cable routing a lot easier.
> 
> Regarding the noise, what are you using as source? Static could be bad power from a USB port. If the static is still there if the Crack is plugged into an iPhone (or other portable device) then it could be a bad solder joint. If there is a constant hum, it could be a ground loop. Quite a few possibilities and you could try to eliminate some of them.
> 
> ...




I'm sure it's not the source. PC to modi 2 uber with toslink, RCA to crack. Unplugging the RCA from the crack doesn't get rid of the noises. At one point, no RCA plugged in made the noise change from hissing to humming at full volume. After "shielding" the RCA to pot wires with aluminum, it's sometimes completely quiet at full volume, and other times scratchy. Definitely different than before adding the aluminum. The general background noises I'm also describing happens at any volume, but doesn't get louder if I turn the volume up.

Honestly, I'm completely confused about it. Sometimes I find a correlation between the noise and something, and then an hour later, they're no longer related. That was the case of the tube heat. At first it seemed like the colder tubes had more noise, now it seems they have less.

I'll do some research into attenuators later on. I'd like to try and solve the noise first, but thanks for the recommendations. I'll keep them in mind.

I have a feeling I'm going to be spending many hours poking connections and resoldering...


----------



## audiojun

When I installed my speedball it basically magnified all my hum, buzz and stuff. once those issues got addressed the speedball was more quiet than pre-speedball. I think it's best to follow what the pros say at bottlehead though.


----------



## grausch

chuckwheat said:


> I'm sure it's not the source. PC to modi 2 uber with toslink, RCA to crack. Unplugging the RCA from the crack doesn't get rid of the noises. At one point, no RCA plugged in made the noise change from hissing to humming at full volume. After "shielding" the RCA to pot wires with aluminum, it's sometimes completely quiet at full volume, and other times scratchy. Definitely different than before adding the aluminum. The general background noises I'm also describing happens at any volume, but doesn't get louder if I turn the volume up.
> 
> Honestly, I'm completely confused about it. Sometimes I find a correlation between the noise and something, and then an hour later, they're no longer related. That was the case of the tube heat. At first it seemed like the colder tubes had more noise, now it seems they have less.
> 
> ...


 
 I would get a thread going on the Bottlehead site and post some pictures. The guys there are pretty good at the troubleshooting.
  
 I have never had humming, so never needed to investigate potential causes for that. However, here is a helpful ground path check that can eliminate some potential problems (http://bottlehead.com/smf/index.php?topic=4812.0). If everything is properly grounded, you have no ground loop elsewhere and the RCA cables are properly braided / shielded then you should have no hum.
  
 When I had static in my Crack, my first problem was a noisy USB port. Once that was fixed I also had another problem with the soldering at T13. Once that was fixed my amp was dead quiet. With the help of the Bottlehead crew, you should start eliminating problems until you find a solution. Might take a bit of time, but definitely worth it.
  
 If your Modi 2 is running in 24-bit mode, you can decrease the volume on your PC without any loss in sound quality. Look for *GUILT-FREE VOLUME ADJUSTMENT **here - *http://nwavguy.blogspot.lu/2012/04/odac-released.html. If you do not wish to go that route, then the Harrison Labs attentuators are the easiest solution. Just make sure you go for the -12db padding. The smaller values do not make enough of a difference.


----------



## audiojun

Well with enough evidence I am introducing the aluminum foil mod. Wrap a piece aluminum foil around 12au7 and ground it to the chasis. Easiest mod ever and it Eliminates noise from rfi interference.

Next I am going to try to use something else like chicken wire or something that can see through and can cage the tube. since aluminum foil looks ugly.




 Now some proof:

I put my phone up to my 6080 power tube and just searched the web, it didn't make a sound.

I did the same to the 12au7 input tube and dang it picked up noise from my phone. So I did the aluminum foil mod. I tested again with my phone and yep zero noise at max volume.

Another project I did today:

 asrock z97 motherboard had some computer noises from it's Headphone jack. After examining I noticed none of the wires from inside my case was actually grounded or shielded. I removed the wires that where not grounded from the case cause they can pick up noise like an antenna. I wrapped aluminum foil around the HD audio cable (goes to front headphone header) inside the computer then I wrapped a piece of paper around the foil (I don't want it to short my board with aluminum) then I attached an piece of aluminum from the shield to the case effectively grounding it. resulted in no noise from computer even when amped from crack.

Earlier I wrapped aluminum around the wires from rca input to the pot, it lowered noise more than just braiding.

Guys this mod is awesome! I am going to have a aluminum foil crack soon with my aluminum foil hat.


----------



## mcandmar

You are one step away from wearing a tinfoil hat 
	

	
	
		
		

		
			




  
 Seriously though, fit one of these http://www.ebay.co.uk/itm/390293225944


----------



## Walderstorn

mcandmar said:


> You are one step away from wearing a tinfoil hat
> 
> 
> 
> ...


 
 Cool, didnt know about those, are they easy to install?


----------



## mcandmar

They are a replacement tube socket, so you would have to unsolder the old socket, then resolder all the connections onto the new socket.  The two LED's would make it a fiddly job on a crack.
  
 Another alternative is a slip on shield e.g. http://www.ebay.co.uk/itm/361225703724


----------



## adydula

Boy all this stuff on noises, hissing, pops, cracks, intermittents, chopsticks makes me laugh!! 
 Being an old timer, growing up with tubes, building countless tube projects some which has 21 tubes, makes me smile alot!
  
 Its like dealing with vinyl for years, hiss, pops, ticks, tracking etc..anti static guns, pads etc...terrible.
  
 Then cd's come on the scene and they have bandwidth, silent, but still foreign! Many doubting thomas's, still today unless its a high sample
 or high bit rate....
  
 The Crack, and I do have one with Speedball, I built to see how it worked with my set of T90's. Having many solid state amps from many vendors and building three recent DIY SS amp. Which all are toatally silent and work very well..with none of the worts that many of you have gone thru with the Crack!
  
 That said its still a great amp. If put together well, soldering, good tubes, keep away from interference, like dont put it next to your 2.4/5ghz wireless box, or your cell phone...it will give you thousands of hours of great performance!
  
 But it will have its worts over time, mechanical  jolts, tapping on the tubes, jiggling tubes in sockets will drive you crazy chasing noise and hum.
  
 Welcome to the world of tubes.....now where is my turntable micro micro tracking adjuster??
  
 A.


----------



## Jason Orlando

bigbenrfan99 said:


> I don't know if you made a decision, but I'm listening to the HD700 + Crack with Speedball combo now.  It's fantastic in my opinion.  I can't really compare it to any other amp at the moment, but it is better than my memory of it with the Burson HA-160.  I don't really think the Crack will extend the bass very much, but the bass quality is excellent.  I have a hard time imagining someone describing the combo as having a "lack of bass."  I haven't encountered any sibilance so far.


 
 Thanks for the feedback.  I ordered the standard crack during the leap-day sale.   From what i read, the standard crack alone seems to help the bass more than having the speedball installed.  Did you try it before and after the speedball upgrade?
  
 I was able to get some bass out of my O2 by EQing it +20db.   Still looking forward to the crack.


----------



## Jason Orlando

audiojun said:


> asrock z97 motherboard had some computer noises from it's Headphone jack. After examining I noticed none of the wires from inside my case was actually grounded or shielded. I removed the wires that where not grounded from the case cause they can pick up noise like an antenna. I wrapped aluminum foil around the HD audio cable (goes to front headphone header) inside the computer then I wrapped a piece of paper around the foil (I don't want it to short my board with aluminum) then I attached an piece of aluminum from the shield to the case effectively grounding it. resulted in no noise from computer even when amped from crack.
> 
> Earlier I wrapped aluminum around the wires from rca input to the pot, it lowered noise more than just braiding.
> 
> Guys this mod is awesome! I am going to have a aluminum foil crack soon with my aluminum foil hat.


 
 This is a common problem with computer builds.  Plugging into the rear port should eliminate most of the interference.  Otherwise an external dac is usually how people get around the issue.


----------



## Walderstorn

mcandmar said:


> They are a replacement tube socket, so you would have to unsolder the old socket, then resolder all the connections onto the new socket.  The two LED's would make it a fiddly job on a crack.
> 
> Another alternative is a slip on shield e.g. http://www.ebay.co.uk/itm/361225703724


 
  
 Im not much of a soldering guy but that doesnt seem hard, its just to copy basicly whats already done. Thanks


----------



## audiojun

I might do the slip on shield. It's a boutique part compared to aluminum foil 
	

	
	
		
		

		
		
	


	




.
  


jason orlando said:


> This is a common problem with computer builds.  Plugging into the rear port should eliminate most of the interference.  Otherwise an external dac is usually how people get around the issue.


 
  
 What really helped was I removed a bunch of extra usb ports since they where not even shielded. Then I shielded/grounded the usb ports I was using. Now I get almost zero noise out of my motherboard analog outs yay! And Yes I have an external dac I have the Bifrost, I was just testing out the aluminum foil shielding and it works really well. I thinking people with noisy usb ports can do a simple aluminum foil shielding and ground it, then wrap the foil with an insulator so you don't short the motherboard.


----------



## chuckwheat

grausch said:


> If your Modi 2 is running in 24-bit mode, you can decrease the volume on your PC without any loss in sound quality. Look for *GUILT-FREE VOLUME ADJUSTMENT **here - *http://nwavguy.blogspot.lu/2012/04/odac-released.html. If you do not wish to go that route, then the Harrison Labs attentuators are the easiest solution. Just make sure you go for the -12db padding. The smaller values do not make enough of a difference.


 
 Is that true? At least in the case of 44.1 16bit music? What % could I lower my PC volume if i'm using 192 24bit on the modi?


----------



## Whit3Rav3n

In case of 16 Bit music you can use 8 bit for volume control. You can lower the volume by 48 db without losing bit depth.


----------



## chuckwheat

whit3rav3n said:


> In case of 16 Bit music you can use 8 bit for volume control. You can lower the volume by 48 db without losing bit depth.


 
 I have no idea how Windows 10 implements volume output for using a dac. I'm just wondering if I could lower whatever windows thinks the volume is to 50% or so, and not have any loss.
 Question:
 Could I plug the AMP output to the microphone input on my pc, with nothing connected, and try to capture the sounds it's creating by itself?


----------



## audiojun

I found some good info on how to lower the hum/noise for those of you who still have it.

http://www.diyaudio.com/forums/tubes-valves/211731-heater-wiring-good-bad-ugly.html

I am particularly interested in maybe converting my heater to dc. I just might do it in the future. My crack is dead silent though so obviously it isn't necessary at the moment. but i know 60hz harmonic is unavoidable due to the crack's ac heater design and I can feel the 60hz phase or something when it's cranked up to max though it's dead silent.


----------



## Doc B.

mcandmar said:


> You are one step away from wearing a tinfoil hat
> 
> 
> 
> ...


 
 Great shields. Very high price.


----------



## chuckwheat

So I plugged the output of the Crack to the input on my computer, and recorded the noise in audacity.
 Here's the WAV: https://drive.google.com/file/d/0B6sq2jN3eWR6VF9kYUZmb05GOHM/view?usp=sharing
 This is with no rca cables attached, and some aluminum wrapped around the RCA to Pot braided cables. At least 3 layers of foil is wrapped and grounded.
 I started turning up the volume at around 8 seconds, and turned it down at around 20 seconds. At 30 seconds, I started gently tapping on the 12au7 tube, and also wiggled it slightly in its socket. I didn't hear any of the whining noise that comes every other minute, so I'll just keep recording until it comes. :/


----------



## audiojun

Did wrapping the foil around the 12au7 help at all? Do you live on like a 2nd or 3rd floor by any chance? Because I heard the windings inside the power supply can act as an antenna and rfi can get transmited through the wires and picked up from the tubes. A photo of the inside of your crack will be helpful.


----------



## chuckwheat

audiojun said:


> Did wrapping the foil around the 12au7 help at all? Do you live on like a 2nd or 3rd floor by any chance? Because I heard the windings inside the power supply can act as an antenna and rfi can get transmited through the wires and picked up from the tubes. A photo of the inside of your crack will be helpful.


 
 I cut a piece of pie tin into a cone and used it over the 12au7. Not much difference. I live on the ground floor, but there's many neighbors. I imagine they all have phones, wifi, radios, etc.
 What sort of photos?


----------



## audiojun

take a picture of the underside of your crack.


----------



## chuckwheat

audiojun said:


> take a picture of the underside of your crack.


 
 here ya are: http://imgur.com/a/nuV87
  
 My joints aren't the best, but I don't think they're weak or not contacting well.


----------



## audiojun

Nice pictures looks like you did a good job with your build.
  
 You shoud post those pictures on the bottlehead forum. I am just a noob at this.
  
 My guess is your wires or power supply are picking up interference some how. Try tightening up your power supply. Also if your rca cables are the unshielded kind they will act like antennas, if they are then remove and listen.


----------



## chuckwheat

audiojun said:


> Nice pictures looks like you did a good job with your build.
> 
> You shoud post those pictures on the bottlehead forum. I am just a noob at this.
> 
> My guess is your wires or power supply are picking up interference some how. Try tightening up your power supply. Also if your rca cables are the unshielded kind they will act like antennas, if they are then remove and listen.


 
 I think i'll go ahead and make a bottlehead thread. I've been putting it off because i'm going on vacation in a few days. I'll do it when i get back next week when I can really dive into refining the crack build.
 I have these RCA cables: http://www.amazon.com/KabelDirekt-feet-Stereo-Audio-Cable/dp/B00DI89I04
 They're cheap as dirt, but they work well. I've tried them on bigger systems and they sound perfectly fine.
 I think they're shielded well. I don't hear any noise with them connecting the modi and magni...


----------



## grausch

chuckwheat said:


> Is that true? At least in the case of 44.1 16bit music? What % could I lower my PC volume if i'm using 192 24bit on the modi?


 
 I have found this piece that actually recommends adjusting volume on your PC rather than the amp - http://bitperfectsound.blogspot.lu/2013/03/digivol.html
  
 There may be some channel imbalances with some of the pots in the Crack. The Bottlehead suggested solution is to turn down the PC volume so that you can comfortably listen to the Crack without any channel imbalance. I have done that in the past, and unless channel imbalance is present, I doubt I could tell the difference between running my PC at full volume or at lower volume. You can always test this yourself.


----------



## daltonljj

adydula said:


> Boy all this stuff on noises, hissing, pops, cracks, intermittents, chopsticks makes me laugh!!
> Being an old timer, growing up with tubes, building countless tube projects some which has 21 tubes, makes me smile alot!
> 
> Its like dealing with vinyl for years, hiss, pops, ticks, tracking etc..anti static guns, pads etc...terrible.
> ...


 
  Isn't that the fun of this entire diy hobby. The satisfaction in building it, rectifying issues if any and learning a lot along the way


----------



## chiggah

If anyone is interested to let go a Bottlehead crack + speedball 230V, please let me know


----------



## chuckwheat

chiggah said:


> If anyone is interested to let go a Bottlehead crack + speedball 230V, please let me know




You should make a post in the wanted section



grausch said:


> I have found this piece that actually recommends adjusting volume on your PC rather than the amp - http://bitperfectsound.blogspot.lu/2013/03/digivol.html
> 
> There may be some channel imbalances with some of the pots in the Crack. The Bottlehead suggested solution is to turn down the PC volume so that you can comfortably listen to the Crack without any channel imbalance. I have done that in the past, and unless channel imbalance is present, I doubt I could tell the difference between running my PC at full volume or at lower volume. You can always test this yourself.




I'll give that a try. Thanks.


----------



## adydula

Yes it is....wouldnt have it any other way!! Ha!
  
 Each time I swap out tubes some noise gremlin pops up!
  
 A.


----------



## FunyunBreath

chuckwheat said:


> So I plugged the output of the Crack to the input on my computer, and recorded the noise in audacity.
> Here's the WAV: https://drive.google.com/file/d/0B6sq2jN3eWR6VF9kYUZmb05GOHM/view?usp=sharing
> This is with no rca cables attached, and some aluminum wrapped around the RCA to Pot braided cables. At least 3 layers of foil is wrapped and grounded.
> I started turning up the volume at around 8 seconds, and turned it down at around 20 seconds. At 30 seconds, I started gently tapping on the 12au7 tube, and also wiggled it slightly in its socket. I didn't hear any of the whining noise that comes every other minute, so I'll just keep recording until it comes. :/


 
  
 99% of the time the intermittent hums and rings are from a tube in my experience. Some tubes are noisier than others and just produce those microphonic noises when they heat up. Could be the input or output tube, though I've noticed that the 12au7's generally produce those hums and rings more often than power tubes. I'd buy a new set of tubes and see if that fixes the issue before going through and resoldering and testing components.
  
 The static pops that i'm hearing in the left channel of the recording sound like either a cold joint or a bad component. In my 2nd crack build I had that exact same noise and it took a while to track down. After reflowing every single joint I started checking resistors in the signal path and I ended up having a bad resistor. I found out which one it was by desoldering the 22.1k resistors and flipping them between channels and the noise moved with it.
  
 Good idea recording the output! Wish i would have thought of that at various points when I've been trying to track down an issue


----------



## chuckwheat

funyunbreath said:


> 99% of the time the intermittent hums and rings are from a tube in my experience. Some tubes are noisier than others and just produce those microphonic noises when they heat up. Could be the input or output tube, though I've noticed that the 12au7's generally produce those hums and rings more often than power tubes. I'd buy a new set of tubes and see if that fixes the issue before going through and resoldering and testing components.
> 
> The static pops that i'm hearing in the left channel of the recording sound like either a cold joint or a bad component. In my 2nd crack build I had that exact same noise and it took a while to track down. After reflowing every single joint I started checking resistors in the signal path and I ended up having a bad resistor. I found out which one it was by desoldering the 22.1k resistors and flipping them between channels and the noise moved with it.
> 
> Good idea recording the output! Wish i would have thought of that at various points when I've been trying to track down an issue




I definitely suspect the 12au7. Just wiggling it is enough to cause, change, or stop the noise. Thanks for your advice . I would hate to have to reflow every joint just looking for any improvement. Are 12au7 tubes mostly the same? I'm new to the tubes.


----------



## JamieMcC

Sweet deal on film caps at Partsconnexion for anyone looking to upgrade to film caps
  
http://www.partsconnexion.com/capacitor_film_asc_metal.html?utm_source=getresponse&utm_medium=email&utm_campaign=1express&utm_content=pcX%E2%80%99s+Clearance+Event%3A+50%25+Off+CLARITY+TC+Series+130uF+600V+Film+Cap%3B+40%25+Off+SOLEN+Hepta-Litz+%E2%80%9Cin-stock%E2%80%9D+Inductors%3B+50%25+Off+Select+CARDAS+Solder%3B+80%25+Off+AURA-T+Teflon+Caps+-+4+Values


----------



## audiojun

80uf shouldn't drop the sub bass too much right? For the output caps. From calculator with a load of 240ohms at 100uf I got -3db at 6.6hz and at 80uf its -3 db 8.2hz. I am not sure if I calculated the load right for the 300-550 ohm sennheisers. I am kind of not sure about using less than 100uf since I feel the sens don't have enough sub bass as is but 80uf shouldn't be too much of a difference. I might buy to experiment since I have not changed the output caps yet.


----------



## JamieMcC

audiojun said:


> 80uf shouldn't drop the sub bass too much right? For the output caps. From calculator with a load of 240ohms at 100uf I got -3db at 6.6hz and at 80uf its -3 db 8.2hz. I am not sure if I calculated the load right for the 300-550 ohm sennheisers. I am kind of not sure about using less than 100uf since I feel the sens don't have enough sub bass as is but 80uf shouldn't be too much of a difference. I might buy to experiment since I have not changed the output caps yet.


 
  
 Have you seen this chart 80uf looks like its still in the sweet spot for the Senns very tempted myself but am in the UK so shipping and import duty makes would add substantially to the cost. Price looks very attractive for a ASC product


----------



## Aradea

Guys, just got me BH Crack w/o speedball.
  
 I was scrolling through these pages to find info on the Power and Input tubes.
  
 Can you guys help me what types of Power and Input tubes that this amp can use? Better if you could add the best power and input tubes that are the best by all of you here.
  
 Appreciate so much & sorry for the noob question.


----------



## Tom-s

*Input Tubes (Original: 12AU7)*

 12AU7(A)(WA)
 ECC186
 ECC82
 ECC802(S)
 E8025
 E82CC
 CV4003
 CV4122
 CV491
 5814(A)
 6189(W)(WA)
 6680 (WL6680)
 6067
 7489
 7316
 5963 (computer version of 12AU7)

 Sort-of-Drop-In (but not equivalent - for best results, replace plate resistors with Speedball boards)

 E80CC
 12BH7
  
  
 With adapters:
 6SN7
 6F8G
 6CG7


*Power/Output (Original: 6080)*

 6AS7G
 6080
 6H13C
 5998
 7236
 6N13


----------



## Aradea

Thank you!


----------



## bizkid

Which DT880 sounds better on the crack, the 250 Ohm variant or the 600 Ohm? I found the 600 to be ever so slightly recessed in the mids.


----------



## Keithpgdrb

bizkid said:


> Which DT880 sounds better on the crack, the 250 Ohm variant or the 600 Ohm? I found the 600 to be ever so slightly recessed in the mids.


 

 what are you amping the 880 with now?


----------



## bizkid

I currently dont have a DT880 but i have owned it 3x before. Im considering getting one with the crack. I love tubes.


----------



## audiojun

just going off of dampening factor the 600ohm beyers is better dampened for the crack 120 ohm output impedance thus the drivers will sound more controlled. 600 ohms is tighter, detailed sound vs 250 ohm mushy looser sound. 

tldr; 600 ohm is better for the crack.


----------



## Jimmy24

aradea said:


> Guys, just got me BH Crack w/o speedball.
> 
> I was scrolling through these pages to find info on the Power and Input tubes.
> 
> ...


 
  
 I own the Tung Sol 5998 (Power Tube) and Siemens 5814a (Input Tube).
  
 If you want the best power tube for Crack you'll want to get the WE 421a. The only ones on eBay are $600 new or $216 for one that tests low. The Tung Sol 5998 and Bendix 6080WB are second best. I've had the Bendix 6080WB but I didn't like the sound. It sounded lush and had great sound stage but it was lacking the natural sound that I got from the 5998.
  
 For input tubes, the best for a good price is the CBS Hytron-JHY 5814a with flat grey/black plates. Almost as good as the Siemens 5814a and around 3 times less the cost. Very natural sounding, great sound stage, and exceptional clarity.
  
 If price is not an issue definitely try the WE 421A. I'm not sure what the best input tube is so you'll have to ask around for that.
  
 If you want to buy the Tung Sol 5998 for a good price go to vacuumtubes.net. They have excellent prices and they still might also have the CBS Hytron JHY 5814a flat/grey plates.


----------



## JamieMcC

aradea said:


> Guys, just got me BH Crack w/o speedball.
> 
> I was scrolling through these pages to find info on the Power and Input tubes.
> 
> ...


 
  
  
 Have a read of Nick Tams excellent multi 6080/6as7 review I thought his descriptions of the different tube characteristics were bang on the money.
  
 Its worth bearing in mind that this review is based on a modified Crack (details given of the test set up at the bottom of the review). Running the very top tier premium tubes in a stock Crack with a budget system then results will fall short of the characteristics he describes and could be considered a bit of a waste of a beautiful old tube as your only ever going to be getting a taster of what these top tier tubes are capable of delivering. Funds may be more wisely spent moving up the food chain to the Sex, Crack-a-two or Mainline for better performance than chasing premium tubes.  
  
http://the-key.enix.org/~krystal/review-tube-bottlehead.html


----------



## chuckwheat

jamiemcc said:


> aradea said:
> 
> 
> > Guys, just got me BH Crack w/o speedball.
> ...





List of tubes that can be used is on the bottlehead forum:
http://bottlehead.com/smf/index.php?topic=663.0

I think a lot of people will agree either a Tung-Sol 5998 or WE421A are some of the best power tubes for the crack. Not sure about input tubes though.

Edit:
Unrelated, but here's a pretty picture 







Sent from my Nexus 6P using Tapatalk


----------



## Doc B.

Just thought I'd post a pic of how I build a Crack these days -
 tight twisted cables, careful wire dress, and some slightly different wire routing than shown in the manual.
 This one is ready for the Speedball upgrade installation.


----------



## grausch

doc b. said:


> Just thought I'd post a pic of how I build a Crack these days -
> tight twisted cables, careful wire dress, and some slightly different wire routing than shown in the manual.
> This one is ready for the Speedball upgrade installation.


 
 That is a beautiful build. Out of curiosity, do you use 14U or 22L for the ground? I think I see a ground wire going past the back of the transformer, so it looks like 14U, but I am not 100% certain from the photo.


----------



## Doc B.

Thanks for the kind words. I've had a little bit of practice over the past 25 years.
  
 I wish I had never written about that 14 or 22 terminal selection. It's a theoretical observation, nothing more, and really makes no difference. Cracks that exhibit noise are usually a result of builders rushing the build and thus not taking time to develop their wiring and soldering skills. Make sure your wiring is neat, solder joints are excellent and it won't make a whit of difference which terminal you use.
  
 More important refinements can be seen in this build. Notice the tight twist on the heater wiring and the tight braid on the input wiring. The sharp angles will keep noise down as the wires cross each other as close as possible to 90 degrees. I pre-braided and pre-twisted the wire before installing it.
  
 Note also that I rerouted a few wires around the front terminal strip to better clear the yet to be installed Speedball PC board standoffs.
  
 I will emphasize once again that old style 62/38 tin/lead solder is_ far_ easier to use than the lead free stuff. Someone left a spool of Sn96 on the bench yesterday. I thought my solder station was broken because the dwell time on each joint was so long. When I realized what was going on and grabbed some 62/38 the process went about three times as fast.


----------



## FunyunBreath

Looks awesome Doc!
  
 I used the Cardas eutectic solder when I built mine and its a dream to work with. Used the standard 62/38 on my first build and the eutectic was just as easy if not easier to work with on my 2nd build.


----------



## Doc B.

Actually the "standard" is 60/40. 63/37 is the eutectic proportion, and I have no good reason to offer why the heck I wrote 62/38.


----------



## chuckwheat

So I'm going to try swapping out the stock tubes to see if they solve my noise issues from a while ago. What do you guys recommend? They don't need to be those super-rare expensive tubes. Something comparable to the stock tubes would work. Thanks fellas


----------



## Keithpgdrb

Bottle head would send you new ones if the ones that came with it are bad. Cheap too.


----------



## chuckwheat

keithpgdrb said:


> Bottle head would send you new ones if the ones that came with it are bad. Cheap too.


 
 I'm not sure if they are bad. I made a bunch of unorganized posts about the noise issues I've had with my crack, and was told to try replacing the tubes at one point. I will consistently hear fuzzy ringing noises that will start randomly, and moving the tubes a little in their socket or tapping them gently will stop the noise for a little while.


----------



## Solarium

jimbo24 said:


> I own the Tung Sol 5998 (Power Tube) and Siemens 5814a (Input Tube).
> 
> If you want the best power tube for Crack you'll want to get the WE 421a. The only ones on eBay are $600 new or $216 for one that tests low. The Tung Sol 5998 and Bendix 6080WB are second best. I've had the Bendix 6080WB but I didn't like the sound. It sounded lush and had great sound stage but it was lacking the natural sound that I got from the 5998.
> 
> ...


 
 I just got a BH Crack w/ speedball too, and got started hunting down on tubes. Planning on getting a used a TS5998. If I end up getting a used one, with say about 200-300 hours used on them, will that change the sound output much? What's the lifetime on these tubes?
  
 Also, do input tubes make much difference? They're not terribly expensive so I don't mind getting one new, but just curious.


----------



## Keithpgdrb

chuckwheat said:


> I'm not sure if they are bad. I made a bunch of unorganized posts about the noise issues I've had with my crack, and was told to try replacing the tubes at one point. I will consistently hear fuzzy ringing noises that will start randomly, and moving the tubes a little in their socket or tapping them gently will stop the noise for a little while.


 

 Yeah, that ringing noise makes me think its a tube.  but you will really get great help at the bottlehead forums as well.  I wonder if I have one of my old tubes I can get to you.  I'll look.


----------



## Ultrainferno

I dedicated the first post of our new series to the Crack. Still love it, I just wish I had more time to use it


----------



## Aradea

Yeah I'm also a new crack owner and started with Raytheon power and input tubes. Now I got the Tung sol 5998 and Brimar's long plate on mine.. I'm really loving it!


----------



## chiggah

What do I need for Cracks (US Voltage) to be used in EU/AU/NZ countries with 230V ?

 Can i simply use a transformer ? Or would it need to be a specific spec - ie frequency etc?


----------



## Doc B.

You just need a 230-120V step down transformer. Needs to be rated for about 50VA minimum to give you some headroom. The way most step downs are made a bit higher VA rating is a good thing. I'd look for more like 100VA or higher.


----------



## Doc B.

ultrainferno said:


> I dedicated the first post of our new series to the Crack. Still love it, I just wish I had more time to use it


 
 Wow! Thank you so much!


----------



## chiggah

doc b. said:


> You just need a 230-120V step down transformer. Needs to be rated for about 50VA minimum to give you some headroom. The way most step downs are made a bit higher VA rating is a good thing. I'd look for more like 100VA or higher.


 
  
 I mean convert from USA to NZ. I live in New Zealand
  
 So I guess i will need a step-up transformer ? 110V to 240V ?
  
 Any suggestion on brands I should use ? Or can i pretty much use any transformer from the hardware/electronics store ?


----------



## Tom-s

This thread really makes me smile 
	

	
	
		
		

		
			





 .
  
 I'm so glad the BH crew is always there to help customers with really complex problems.
  
 Thanks for the great products and support!


----------



## Doc B.

chiggah said:


> I mean convert from USA to NZ. I live in New Zealand
> 
> So I guess i will need a step-up transformer ? 110V to 240V ?
> 
> Any suggestion on brands I should use ? Or can i pretty much use any transformer from the hardware/electronics store ?


 
 Yup, that will require a 120-240VAC step up transformer, of the same general VA rating. You can find them on ebay, and possibly a travel supply store might have something usable - though that stuff is generally made for appliances with a low power draw.


----------



## Solarium

Got my BH Crack w/ speedball today! Finally seeing what all the fuss about (after all these years, and returning the massdrop BH crack kit back in 2014). Haven't even gotten to the tube rolling yet, and even when using the stock tubes I'm impressed. I'm surprised that the synergy with my iDSD as the DAC is greater than with my bifrost multibit, due to iDSD's warmer signature. Listening to norah jones actually gave me goosebumps and made my neck hair stand up! What are all your experiences in what kind of DAC's to pair with the Crack?
  
 Someone in another thread mentioned some upgrades for the crack, including film caps, Valab 23 stepped attenuator volume pot, and a Triad c-7x choke. Where do I get these components? Do they make more of a difference than tube rolling?
  
 If anyone's selling output tubes from the *5998 (TS/Chamtam)* and *6080 (TS/Bendix)* series and also input tube like *CBS Hytron-JHY 5814a* with flat grey/black plates, please let me know  Let the tube rolling begin!


----------



## grausch

solarium said:


> Someone in another thread mentioned some upgrades for the crack, including film caps, Valab 23 stepped attenuator volume pot, and a Triad c-7x choke. Where do I get these components? *Do they make more of a difference than tube rolling?*


 
   
I have not tried any other tubes, but I believe common consensus is that once Speedball is installed, the difference between tubes is much smaller than before. Although that being said, there is a tube-rolling thread on the Bottlehead website so you could read through that (http://bottlehead.com/smf/index.php?topic=663.0).

  
 Stepped attentuator and choke can be bought off ebay. For film caps, ebay may be a good option. Other options are http://www.partsconnexion.com/, www.hificollective.co.uk/ or https://www.parts-express.com/. Depending on where you are geographically located, you may need to shop around to get the best prices.
  
 Regarding how much of a difference they make, I can honestly say that I don't know. My hearing is not bad, but with my DT770s I notice almost no difference and I am not sure whether or not I am imaging these differences. At any rate, modding the Crack is fun, but I ran into diminishing returns from the beginning - a stock Crack that is properly built is still an excellent amp.


----------



## Tom-s

Schottky diodes rectifiers are another worthy upgrade (+-10$).
 E80cc/12bh7/5687 switches are another cheap one but not as easy.
 With these the FAQ #3 could best be implemented on the VALAB attenuator from the start (more easy when installed from the start).


----------



## Solarium

grausch said:


> I have not tried any other tubes, but I believe common consensus is that once Speedball is installed, the difference between tubes is much smaller than before. Although that being said, there is a tube-rolling thread on the Bottlehead website so you could read through that (http://bottlehead.com/smf/index.php?topic=663.0).
> 
> Stepped attentuator and choke can be bought off ebay. For film caps, ebay may be a good option. Other options are http://www.partsconnexion.com/, www.hificollective.co.uk/ or https://www.parts-express.com/. Depending on where you are geographically located, you may need to shop around to get the best prices.
> 
> Regarding how much of a difference they make, I can honestly say that I don't know. My hearing is not bad, but with my DT770s I notice almost no difference and I am not sure whether or not I am imaging these differences. At any rate, modding the Crack is fun, but I ran into diminishing returns from the beginning - a stock Crack that is properly built is still an excellent amp.


 
 The diminishing returns is exactly what I was thinking about too, especially since I bought it prebuilt with the speedball in a practically new condition for $300. I have no experience in modding the crack at all. Getting both the TS5998 and the 5814a input tube would add about $100 to the amp, which is about 25%. I didn't know about tubes making a smaller difference with the speedball installed, but that's good to know. I'm going to listen to the crack some more and figure out whether I want to continue using it before committing myself to more upgrades. I like the tube sound, but it typically does not go well with EDM, which is 90% of what I listen to. I'm also considering getting the iFi iCAN SE to go along with my iDSD, although I'm completely satisfied with the iDSD amp portion too after EQ'ing.


----------



## ChrisR1

Have any of you fine gentlemen or women compared Sylvania's "vintage" 6AS7G with RCA's 6AS7G in their BH Crack? I love RCA's version, I was thinking about picking up an old Sylvania for rolling or at least backup...


----------



## nykobing

i have one of those Sylvania's someplace and I remember it sounding exactly like an RCA one. I am pretty positive RCA made it.


----------



## grausch

solarium said:


> The diminishing returns is exactly what I was thinking about too, especially since I bought it prebuilt with the speedball in a practically new condition for $300. I have no experience in modding the crack at all. Getting both the TS5998 and the 5814a input tube would add about $100 to the amp, which is about 25%. I didn't know about tubes making a smaller difference with the speedball installed, but that's good to know. I'm going to listen to the crack some more and figure out whether I want to continue using it before committing myself to more upgrades. I like the tube sound, but it typically does not go well with EDM, which is 90% of what I listen to. I'm also considering getting the iFi iCAN SE to go along with my iDSD, although I'm completely satisfied with the iDSD amp portion too after EQ'ing.


 
 My first mod was the VA Labs attentuator. When I received it, the PCB was installed upside down. Luckily by looking at pictures of other builds I realised what the problem was and PB on the Bottlehead forums was very helpful in explaining how to check for in, out and ground. I was a bit nervous installing it, but it worked first time and set me on the path for further upgrades. I then rebuilt the Crack using higher gauge cloth-covered wire.
  
 Next upgrades were replacing my input jack and RCAs, then the Schottky diodes, replacing the last resistor in the PSU with a choke, replacing the first two PSU caps with 470uF caps, replacing the final PSU cap with a 270uf a film cap, bypassing the final PSU cap with four Russian cruise missiles.
  
 I still have the Speedball waiting (more than a year now) and film caps for the audio path, as well as some bigger Russian cruise missiles for bypassing duty.
  
 With the current mods, the biggest changes are a) the effectiveness of the gravity mounted plate has increase tremendously and b) it now takes seven seconds for the audio to fade once I switch off power (was definitely shorter before mods). There may be an increase in bass, but it was impossible to test that by ear. It could also very well be my imagination. Perhaps a set of HD 650s would make the changes more noticeable, but at this point I just enjoy listening to the music.
  
 Modding the Crack is a great confidence-builder since it is so easy to work on, but once you add on the cost of components, shipping and import duty you can easily get to the cost of the Mainline. No matter how much you mod the Crack, the Mainline is still the superior amp. Just something to bear in mind.


----------



## q2klepto

So i received my used Bottlehead Crack w/ Speedball a couple weeks ago, it has a 220v step down transformer as i am in Canada (120v).  Plugged everything in, fired up - tube glow was sexy - but had an extremely loud humming noise.
  
 I guess ill be looking at the build and troubleshoot the problem - but wondering if anything i can focus on first, and which pages in the manual i should be looking at?

 Thanks!


----------



## nykobing

q2klepto said:


> So i received my used Bottlehead Crack w/ Speedball a couple weeks ago, it has a 220v step down transformer as i am in Canada (120v).  Plugged everything in, fired up - tube glow was sexy - but had an extremely loud humming noise.
> 
> I guess ill be looking at the build and troubleshoot the problem - but wondering if anything i can focus on first, and which pages in the manual i should be looking at?
> 
> Thanks!


 
 It might be something so simple as a bad tube, do you have other to try. I have tubes that hum in the crack, but are silent in other amps.


----------



## JamieMcC

q2klepto said:


> So i received my used Bottlehead Crack w/ Speedball a couple weeks ago, it has a 220v step down transformer as i am in Canada (120v).  Plugged everything in, fired up - tube glow was sexy - but had an extremely loud humming noise.
> 
> I guess ill be looking at the build and troubleshoot the problem - but wondering if anything i can focus on first, and which pages in the manual i should be looking at?
> 
> Thanks!


 
  
 I suggest you subscribe to the Bottlehead forum and post in the Crack section you will be able to converse directly with the Bottlehead team and the Cracks designer to help with trouble shooting
  
 Edit looks like you already have


----------



## ChrisR1

So I've been enjoying my Crack w/ Speedball that I completed a few weeks ago immensely using Fiio X5->Crack/Sball->Senn 600.  All genres of music are far more engaging and lifelike, and I can listen with relish for hours.  
 I've been told that switching to a dedicated DAC such as Schiit bifrost would be another big improvement in my listening experience.  I'm hesitant to do this for the simple reason that I like how easy it is to fire up the system and listen for a little while here and there using the X5 as source.  The improvement in my listening experience is already immensely improved from using the Schiit Vali (accurate, but not very engaging) making me wonder if another big bump in quality awaits me if I pick up a Bifrost.  
 Can any of you guys who have a Fiio X5 comment on the difference relative to a dedicated DAC through their Crack/speedball?  It does have Texas Instrument's top-of-the-line DAC chip, but I know that a DAC is more than just the actual chip...
 Any guidance would be greatly appreciated!


----------



## adydula

Stay where you are and enjoy...
 A.


----------



## audiojun

chrisr1 said:


> So I've been enjoying my Crack w/ Speedball that I completed a few weeks ago immensely using Fiio X5->Crack/Sball->Senn 600.  All genres of music are far more engaging and lifelike, and I can listen with relish for hours.
> I've been told that switching to a dedicated DAC such as Schiit bifrost would be another big improvement in my listening experience.  I'm hesitant to do this for the simple reason that I like how easy it is to fire up the system and listen for a little while here and there using the X5 as source.  The improvement in my listening experience is already immensely improved from using the Schiit Vali (accurate, but not very engaging) making me wonder if another big bump in quality awaits me if I pick up a Bifrost.
> Can any of you guys who have a Fiio X5 comment on the difference relative to a dedicated DAC through their Crack/speedball?  It does have Texas Instrument's top-of-the-line DAC chip, but I know that a DAC is more than just the actual chip...
> Any guidance would be greatly appreciated!




Both The Bifrost 4490 and Multibit is an excellent dac for the crack & HD600. I only compared it with a few dacs such as xonar essence stx, an ebay multibit nos dac, fiio e10. The Bifrost just better, it's a league or 2 above the dacs I tried.

Also running from computer as a source has the advantage of using programs such as JRiver. I highly recommend trying it they have a free 1 month trial. I personally found surround effects on medium with no environment effects awesome for soundstage also the EQ is perfectly done and lossless.


----------



## Tom-s

On the bottlehead forum i found the suggestion of the Gustard X20 DAC.
 Here in EU it's about the same price as the Bifrost (the normal one, that is) 
 Reading material: http://www.head-fi.org/t/780385/gustard-x20-dac
 Might be worth it. Can't tell. 
 I'm happy using a M2U.


----------



## deserat

I own the X5 and the Bifrost ( currently multibit but was just Uber ), unfortunately while I own the Crack it's probably still being put in a box so that it can be shipped.  I have however run both the X5 and the Bifrost through the Lyr2 and the hdva 600 ( yes using line out). I do it every so often still just because I like to hear the difference.  In both cases the sound is night and day while driving HD800 and HE 560's.  The first thing you'd notice is the the Bifrost is louder so you can turn the volume down about 1/4 turn on the amplifier.  After that with the multibit anyway, there is a  noticeable difference in soundstage size and mind boggling difference in instrument separation and positioning. It is most apparent in songs that have alot going on, the first song that dropped my jaw in amazement was Tools 10,000 days pt 2, the thunder just became more real and the raindrops because distinctly audible - but orchestral music and even glitch take on a whole new life.  I like the x5 I  use it on the go  with my Momentums ( which I hate ) but  for me anyway it's not even in the same sonic league as the Bifrost. The modi 2 would be better comparison. 

 How apparent this will be with the Crack.... I don't know yet. Depends on how resolving the Crack is and on your headphones.   Will loop back once it's assembled and been running for a bit... that'll be a month or so though.


----------



## audiojun

My Bottlehead Crack is for sale check my signature. Hard to let this go, I have so many fond memories with it, but my wife wants me to sell it since I have 2 headphone amps at the moment.


----------



## silentmoon

I have never listened to any crack otl but I've been living with 6080 for years, tried all 6080 of all versions and countries and found that the best was 6h13c from old Soviet Union. They do not magic, they do not make colorations, they do sound fine and natural.


----------



## chiggah

Just bought my first amp - a used Crack + SB that comes with tubes

How are these tubes and what config should I use with the Sennheiser HD650 ? And how much these tubes worth ?

What upgrade should I be going for first ? Below are the seller comments 



> I have built this amp as carefully and meticulously as I can. The circuit is noise-free and all voltage readings are within spec.
> 
> A high quality Alps RK27 volume pot has been installed instead of the supplied, which has much better low volume tracking. The output capacitors have been installed on leads for easily upgrading to PIO or film capacitors.
> 
> ...


----------



## JamieMcC

chiggah said:


> How are these tubes?
> 
> RCA 6AS7G
> Svetlana 6H13C
> ...


 

 I would take the Svetlana and probably the if using hd650 then the RCA if its a clear top is always a good choice but not so good with other phones like byers.


----------



## Aradea

chiggah said:


> How are these tubes?
> 
> RCA 6AS7G
> Svetlana 6H13C
> ...




I have the Brimar long gray plate and its a musical input tube.


----------



## chiggah

How does a 6BL7 compare to the 5998 TungSol ?


----------



## chuckwheat

audiojun said:


> my wife wants me to sell it


 
 but why!?


----------



## audiojun

chuckwheat said:


> but why!?


 
 I have no desk space, right now It's unused. I also need money for my twins that are about to be born soon. Also I recently built the Torpedo III and loving it 
	

	
	
		
		

		
		
	


	




 but in a way it's feels like it's the opposite of what the crack is all about, it uses output transformers and it's differential push-pull instead of single ended. I wish I could keep both because they sound different enough. The Torpedo III wins on dynamics and resolution but the Crack is better for musicality and smoothness.
  
 edit: My crack doesn't have the full mods just only speedball. A fully modded out Crack or Crack2 should be on another level but I haven't heard it.


----------



## Demoninja

Hey all just wanted to confirm if this is the right part. I'm interested in upgrading the pot to a stepped attenuator but I'm not willing to pony up $150+ so I'm gonna go with a Valab. http://www.ebay.com/itm/Valab-23-Step-Ladder-Type-Attenuator-Potentiometer-100K-Log-Stereo-/301934856580?hash=item464cb84984:g:cekAAOSwo3pWgXR7 Is this the correct part? If it is the right part is there anywhere I can purchase it from for a similar price but faster shipping? I can't seem to find any place to get it besides eBay.


----------



## JamieMcC

demoninja said:


> Hey all just wanted to confirm if this is the right part. I'm interested in upgrading the pot to a stepped attenuator but I'm not willing to pony up $150+ so I'm gonna go with a Valab. http://www.ebay.com/itm/Valab-23-Step-Ladder-Type-Attenuator-Potentiometer-100K-Log-Stereo-/301934856580?hash=item464cb84984:g:cekAAOSwo3pWgXR7 Is this the correct part? If it is the right part is there anywhere I can purchase it from for a similar price but faster shipping? I can't seem to find any place to get it besides eBay.


 

 You have the right one, I haven't seen them for sale anywhere else other than on ebay I have used a several now in different projects. With the Crack you will probably need to braid up some new signal wiring as the Valabs hook up points are on its top and I think I needed a extra couple of inches of length after swapping out the stock pot. 
  
 Importantly don't forget to bridge the two separate channel grounds on the top of the Valab together with a small piece of wire


----------



## chiggah

My crack is dead quiet at minimum volume up to about 1-2 o'clock on the knob. But when I turned off the music and maxed out the volume knob...around 2 o'clock there was some slight hiss...kinda like a white noise and grew louder as I maxed out the volume knob. 
  
 Not complaining because I would never set the volume at 2 o'clock (too loud) anyways, but just curious what noise could that be ? 
  
 Is that the hiss coming from the Asus Essence ST source ? That would be my guess
  
 Would one method to tell is by disconnecting the RCA from the input on the Crack itself ? Please let me know what other methods I can test to determine the source of the sound.
  
 However, I just found the below on the Crack FAQ page - so this is nothing to worry about ?
  
 5.  When I turn my Crack all the way up, I hear some noise, is this normal?
 Generally yes, there will be some noise with the volume control at its maximum level.  The amount of noise will depend greatly on the impedance of the headphones, but the important thing to remember is that this is well beyond a comfortable listening level.


----------



## Demoninja

jamiemcc said:


> You have the right one, I haven't seen them for sale anywhere else other than on ebay I have used a several now in different projects. With the Crack you will probably need to braid up some new signal wiring as the Valabs hook up points are on its top and I think I needed a extra couple of inches of length after swapping out the stock pot.
> 
> Importantly don't forget to bridge the two separate channel grounds on the top of the Valab together with a small piece of wire


 
  
 Thanks for the heads up on bridging the grounds and the potential need for rewiring. I plan on doing a pretty extensive rebuild of my Crack that already called for all new wiring.
  


> However, I just found the below on the Crack FAQ page - so this is nothing to worry about ?
> 
> 5.  When I turn my Crack all the way up, I hear some noise, is this normal?
> Generally yes, there will be some noise with the volume control at its maximum level.  The amount of noise will depend greatly on the impedance of the headphones, but the important thing to remember is that this is well beyond a comfortable listening level.


 
  
 If it's only noisy at volumes way way beyond what you would listen to it at I don't see why you would worry about it, just enjoy your Crack!


----------



## Doc B.

If the noise gets louder when you turn the volume up it's not coming from the Crack. It's coming from the gear ahead of it.


----------



## Solarium

Just grabbed several pieces of tubes at great prices on ebay:
  
 TS 6080 - $38 (output)
 CBS JHY-5814a - $20 (input)
 Telefunken 12AU7 / ECC82 - $32 (input)
  
 3 tubes for the price of 1 TS5998, not bad at all! Can't wait to finally do some tube rolling. I'm wondering if I should still even look for the 5998 at this point.


----------



## Walderstorn

Uuuhhh i would like to try that telefunken.


----------



## Solarium

Testing out the Tung Sol 6080 right now, sounds absolutely superb compared to the stock tube. What stock tubes does the crack usually come with? This one has black plates and a white/grey bottom. The TS6080 sounds more enveloping, larger soundstage, tighter and less boomy bass, less thick. It's hard to use words to describe it but definitely at least a 50% improvement over the stock tube. Best $38 I spent on audio equipment. I hope that the rest of the purchase isn't going to disappoint compared to this! Also just bought a TS5998 for $60, hopefully it'll compliment the TS6080 well


----------



## Solarium

What the hell is going on, even my EDM sound amazing with the crack now! The bass is SO smooth and liquid, the sound is no longer sluggish and thick, so much better than before. I can't believe how much difference tubes can make, WOW.


----------



## audiojun

I agree the TS6080 is much better than stock Sylvania 6080 tube a great value if you can find it cheap. The TS5998 can get expensive it's a good deal because you found one at $60 though.


----------



## Solarium

audiojun said:


> I agree the TS6080 is much better than stock Sylvania 6080 tube a great value if you can find it cheap. The TS5998 can get expensive it's a good deal because you found one at $60 though.


 
 Reading the review of the Sylvania and looking at the pictures shows exactly what I have: smeared, blobby, obscured details, and poor treble extension. Wonder why they would include this as the stock crack tube.


----------



## defbear

solarium said:


> ....Wonder why they would include this as the stock crack tube.


It would come down to availability. There are enough around that they could create kits in quantity. The S.E.X is going away as they can't reliably get the tubes for it. I have ordered the Crack with the Speedball kit. I still have a week or two to wait.


----------



## hdtv00

solarium said:


> Just grabbed several pieces of tubes at great prices on ebay:
> 
> TS 6080 - $38 (output)
> CBS JHY-5814a - $20 (input)
> ...


 
 Yea you should ALWAYS be on the lookout. I have like 4 now. All under $100. They're worth it. I also waited and found a Western Electric 421 too. The Tele 12au7 you picked up is really nice tube for input stage.


----------



## Solarium

hdtv00 said:


> Yea you should ALWAYS be on the lookout. I have like 4 now. All under $100. They're worth it. I also waited and found a Western Electric 421 too. The Tele 12au7 you picked up is really nice tube for input stage.


 
 I just bought one for $60 so I'm pretty happy with it. It's used and it's a Heinz Kaufman but I heard that they are the same as Tung Sol's. What is the point of owning more th an 1 tube of each kind? I mean do they wear out that fast? If I leave on the crack without any music running, does it still run down the life of the tube? I just don't feel like turning it off and on every time I use my headphones.


defbear said:


> It would come down to availability. There are enough around that they could create kits in quantity. The S.E.X is going away as they can't reliably get the tubes for it. I have ordered the Crack with the Speedball kit. I still have a week or two to wait.


 
 Let me know how you like the pairing with your HD800, and how would you compare it to the Lyr 2. I see that you have the iDSD and the bifrost uber, how do the DAC's of each compare? Also, how do you like the Liquid Carbon with your HD800, how does it compare to the amp of the iDSD?


----------



## Hibuckhobby

Whenever the amp is on, it is putting hours on the tube(s). A tube with about 5000 hour
lifespane will last less than a year if left on. 
YMMV,
Hibuck...


----------



## defbear

solarium said:


> I just bought one for $60 so I'm pretty happy with it. It's used and it's a Heinz Kaufman but I heard that they are the same as Tung Sol's. What is the point of owning more th an 1 tube of each kind? I mean do they wear out that fast? If I leave on the crack without any music running, does it still run down the life of the tube? I just don't feel like turning it off and on every time I use my headphones.
> Let me know how you like the pairing with your HD800, and how would you compare it to the Lyr 2. I see that you have the iDSD and the bifrost uber, how do the DAC's of each compare? Also, how do you like the Liquid Carbon with your HD800, how does it compare to the amp of the iDSD?


The Bifrost Uber is now a Bifrost Multibit. I found the Uber with the Lyr2 to be fatiguing with the Hd800 headphones. But that was a new setup. Not burned in at the time. So now I have the Bifrost Multibit. New right now. I found the "Bimby" needs a lot of warm up time to sound it's best. But now the Bimby, Lyr2 and hd800 is a Golden Combonation. It's like they tuned the setup with the hd800. I like it. The hd800 and Liquid Carbon is another favorite. I find no harshness with the pair. The Liquid Carbon sounds better than the ifi idsd. Yet, I went on a 10 day vacation with my HD800, ifi micro idsd and a Microsoft Surface 2 and did not feel deprived. Say what thread am I in? I am looking forward to the Bottlehead Crack. I will have a lot of listening before adding the Speedball. Er, when I get the kit.


----------



## Solarium

hibuckhobby said:


> Whenever the amp is on, it is putting hours on the tube(s). A tube with about 5000 hour
> lifespane will last less than a year if left on.
> YMMV,
> Hibuck...


 
 What happens to the sound when it runs down on hours? Does it change the sound signature, lower the volume, etc?


defbear said:


> The Bifrost Uber is now a Bifrost Multibit. I found the Uber with the Lyr2 to be fatiguing with the Hd800 headphones. But that was a new setup. Not burned in at the time. So now I have the Bifrost Multibit. New right now. I found the "Bimby" needs a lot of warm up time to sound it's best. But now the Bimby, Lyr2 and hd800 is a Golden Combonation. It's like they tuned the setup with the hd800. I like it. The hd800 and Liquid Carbon is another favorite. I find no harshness with the pair. The Liquid Carbon sounds better than the ifi idsd. Yet, I went on a 10 day vacation with my HD800, ifi micro idsd and a Microsoft Surface 2 and did not feel deprived. Say what thread am I in? I am looking forward to the Bottlehead Crack. I will have a lot of listening before adding the Speedball. Er, when I get the kit.


 
 I have a hard time telling different DAC's apart. I had the bimby and the Lyr 2 combo before and tested for a month with the HD800, it was good I thought but it wasn't worth so much more than my iDSD. What do you feed into the LC, how do you like that vs Lyr 2? I'm sure you'll love the crack, it's absolute magic with the TS6080 and HD800 right now. Made me believe in tubes again.


----------



## Hibuckhobby

As they age tube "can" get noisy, lose gain, change sonic signature and/or short internally. If the latter occurs, associated parts can fail as well.


----------



## Solarium

hibuckhobby said:


> As they age tube "can" get noisy, lose gain, change sonic signature and/or short internally. If the latter occurs, associated parts can fail as well.


 
 At what point are you supposed to change the tubes?


----------



## defbear

solarium said:


> What happens to the sound when it runs down on hours? Does it change the sound signature, lower the volume, etc?
> I have a hard time telling different DAC's apart. I had the bimby and the Lyr 2 combo before and tested for a month with the HD800, it was good I thought but it wasn't worth so much more than my iDSD. What do you feed into the LC, how do you like that vs Lyr 2? I'm sure you'll love the crack, it's absolute magic with the TS6080 and HD800 right now. Made me believe in tubes again.


The Lyr2 is a nice amp. I use it. It got better with new Gold Lion tubes. The Liquid Carbon sounds better. I can't say it 'smokes' it. But the LC is perhaps on another level. I use a Emotiva Stealth DAC-1. So far it beats Bimby as well. But Bimby is not broken in fully. The Emotiva with the Liquid Carbon is a fully balanced system. Add a set of balanced HD800 headphones and it's a hard setup to beat for the money.


----------



## Solarium

defbear said:


> The Lyr2 is a nice amp. I use it. It got better with new Gold Lion tubes. The Liquid Carbon sounds better. I can't say it 'smokes' it. But the LC is perhaps on another level. I use a Emotiva Stealth DAC-1. So far it beats Bimby as well. But Bimby is not broken in fully. The Emotiva with the Liquid Carbon is a fully balanced system. Add a set of balanced HD800 headphones and it's a hard setup to beat for the money.


 
 Isn't the LC solid state? I don't understand how solid state can be much different from one another without adding coloration. Tubes I understand, because of their coloration can be favorable or unfavorable depending on setup, but aren't all solid state technically supposed to be completely neutral/transparent?


----------



## defbear

solarium said:


> Isn't the LC solid state? I don't understand how solid state can be much different from one another without adding coloration. Tubes I understand, because of their coloration can be favorable or unfavorable depending on setup, but aren't all solid state technically supposed to be completely neutral/transparent?


That's the official story.


----------



## Aradea

solarium said:


> I just bought one for $60 so I'm pretty happy with it. It's used and it's a Heinz Kaufman but I heard that they are the same as Tung Sol's. What is the point of owning more th an 1 tube of each kind? I mean do they wear out that fast? If I leave on the crack without any music running, does it still run down the life of the tube? I just don't feel like turning it off and on every time I use my headphones.
> Let me know how you like the pairing with your HD800, and how would you compare it to the Lyr 2. I see that you have the iDSD and the bifrost uber, how do the DAC's of each compare? Also, how do you like the Liquid Carbon with your HD800, how does it compare to the amp of the iDSD?



Can you explain to me the characteristics of the Heinz Kaufman 12au7? I've tried searching for a review online but couldn't find one

Thanks


----------



## deserat

Has anybody played with the Sophia 12au7?  I know the 300B is much beloved, and noticed they do make a 12au7. Haven't been able to find any reviews or mentions of the tube in any application let alone the Crack. It's a bit pricey for me to just buy without at least some unknown, untrusted source telling me how great it is.


----------



## Solarium

walderstorn said:


> Uuuhhh i would like to try that telefunken.


 


hdtv00 said:


> Yea you should ALWAYS be on the lookout. I have like 4 now. All under $100. They're worth it. I also waited and found a Western Electric 421 too. The Tele 12au7 you picked up is really nice tube for input stage.


 
 Got the Telefunken ECC82/12AU7 and CBS Hytron 5814a today. The telefunken is definitely special, it has a very interesting reverb, very large soundstage, superb treble. The only shame is that the right channel gets a loud hiss when I use this, so I suspect there's some kind of damage it. It does have the diamond on the bottom plate so it's an authentic one. Also, while the reverb is cool, I prefer to listen without it for my EDM, so I might just return it. I might get it later down the line for classical music though, I think the sound signature would be absolutely perfect for classical music, especially large symphonies.
  
 The CBS-JHY Hytron 5814a, compared to the stock tube, has a larger soundstage, it's faster and more transient, almost solid-state like, tighter bass, less thick, more airy, more clarity, more pronounced treble and better extension. It is so far the perfect pairing with my TS6080, because it brings the sweetness and thickness a tad lower. The TS6080 by itself though, gave me a lot more wow than these input tubes did. Perhaps I just have higher expectations now.
  
 Will be getting my TS5998 later this week, so can't wait to make some more comparisons  This is fun!


----------



## q2klepto

I think i fixed all my issues with my Crack + Speedball - but i notice an audible noise floor at 0 volume.  This is with stock tubes - is this normal with the CS?
  
 The noise floor is present with my HD800s, but weirdly enough not detectable with my TH-X00. I would think with the lower impedance/higher sensitivity the X00 it would be worse. Guess it has something to do with Damping Factor?


----------



## Tom-s

I'd suggest using a (what's it called...?) cocktail pick or something to test all the solder joints while listening with your HD800's.


----------



## FunyunBreath

Try some different tubes before going through and resoldering stuff. A lot of tubes just aren't low noise and will have an audible noise floor. I'd start with trying a different 12au7 first and see if that fixes the issue.


----------



## Tom-s

If your pin pick test is negative you don't need to resolder anything and you know your amp is sounding it's best. 
  
 Be very careful when performing this test.


----------



## Walderstorn

q2klepto said:


> I think i fixed all my issues with my Crack + Speedball - but i notice an audible noise floor at 0 volume.  This is with stock tubes - is this normal with the CS?
> 
> The noise floor is present with my HD800s, but weirdly enough not detectable with my TH-X00. I would think with the lower impedance/higher sensitivity the X00 it would be worse. Guess it has something to do with Damping Factor?


 


 My problem was the input tube.


----------



## q2klepto

walderstorn said:


> My problem was the input tube.


 
 Which one is that? The big one or the small one? lol


----------



## Walderstorn

q2klepto said:


> Which one is that? The big one or the small one? lol


 
 The small one 12AU7.
  
I noticed after i gave it a little nudge that it ringed even more when it was on. I thought it was a bad solder but it was the tube itself, the stock one.


----------



## q2klepto

walderstorn said:


> The small one 12AU7.
> 
> I noticed after i gave it a little nudge that it ringed even more when it was on. I thought it was a bad solder but it was the tube itself, the stock one.


 
  
 Cool thanks - its kind of annoying at low volumes - ill recheck the solder joins/voltages ..if everything lines up ill look at getting a quiet/higher end tube.  Didnt really want to start tube rolling tho ..


----------



## hdtv00

Oh man you have to tube roll take your time find the right price.


----------



## defbear

Hooray, my Crack kit has shipped. Will see it next week. Besides building the amp, I'm looking forward to finishing the case. I build guitar pedals for a hobby and the case is always fun. Would it be non-audiophile to have your Bottlehead Crack incased in a psycodelic drip. Dancing Tubes? Space Nebula! Hmmm


----------



## Jimmy24

hdtv00 said:


> Yea you should ALWAYS be on the lookout. I have like 4 now. All under $100. They're worth it. I also waited and found a Western Electric 421 too. The Tele 12au7 you picked up is really nice tube for input stage.


 

 Hi HD. Would you say the WE 421a is a nice upgrade from the TS 5998? What are the differences? Looking into buying one. Thanks.


----------



## Solarium

How long should you wait after the amp is off for the tubes to cool off to switch tubes? I just wait for 10-20 seconds, will that damage the tubes at all? I use some paper towels to remove it and to put it back on, so it won't leave my fingerprints all over these beautiful tubes


----------



## hdtv00

jimbo24 said:


> Hi HD. Would you say the WE 421a is a nice upgrade from the TS 5998? What are the differences? Looking into buying one. Thanks.


 
 I love mine is it worth tons extra money. I don't honestly thing so but at same time I'm glad I have one. To me I hear better highs, How I listen is I play string instrument, or horns maybe some bells type sound in high res audio and give a listen when I change a tube. The more natural and life like it sounds the better I consider it. I think it is better but not leaps and bounds. Like not worth $200 more better hell no. I'm nearly as happy with my 4 5998's as with it. I save it though You can find one for $200 if you are patient. I paid I think $180-190. Don't let greedy idiots here convince you they're worth tons of extra money.
  
 But really I've seen one guy here I HATE because he just milks people for money. Probably I'd bet trades or deals he got from other members too. He had 5998 single one listed for $300-400 like What ever dude. That's messed up.


----------



## Solarium

Loving the Heinz 5998 so far, loses some of the warmth and smoothness of the TS6080 but gain clarity, better treble extension, larger soundstage. I would say that the mids on the 6080 is equally good, and the bass is more addictive and more pronounced. It all comes down to personal preferences, and I would say get both since you can find the 6080 $30-40 and it's easily worth the investment.


----------



## ClintonL

Anywhere you can get this prebuilt? In Aus and my soldering skills are filthy and don't want to ruin a good piece of kit.
  
 Cheers


----------



## q2klepto

Ok - did a voltage check and everything is ok - i guess the slight noise floor/hum is tube related.
  
 Can anyone recommend some dead silent tubes? It would be the power tube that usually causes hum?


----------



## audiojun

q2klepto said:


> Ok - did a voltage check and everything is ok - i guess the slight noise floor/hum is tube related.
> 
> Can anyone recommend some dead silent tubes? It would be the power tube that usually causes hum?


 
  
 Take a picture of the internals of your crack.
  
 Lots of reasons for hum I spent a while chasing that hum and fixing it.
  
 some reasons: Input wires was not braided tightly, power supply is not screwed on tightly, ac heater wires to the tubes not twisted tightly, bad soldier connections especially the ground connections. I haven't had a tube that hummed before, it was usually a ringing sound from bad tube. The 60hz-120hz hum is always from the power.
  
 Did the hum exist before speedball? The speedball tends to amplify whatever existing hum you had.


----------



## q2klepto

I bought it used, previous* owner said it had a slight hum.. But he wasn't the builder heh

Heres a post I started on the bh forums 
http://bottlehead.com/smf/index.php?topic=9029.0

And here's an album of the insides 

Http://imgur.com/a/PKrwL

What do you think? 



audiojun said:


> Take a picture of the internals of your crack.
> 
> Lots of reasons for hum I spent a while chasing that hum and fixing it.
> 
> ...


----------



## Solarium

Any comparisons of the Crack-a-two vs the Crack w/ speedball yet?


----------



## audiojun

q2klepto said:


> I bought it used, prevention owner said it had a slight hum.. But he wasn't the builder heh
> 
> Heres a post I started on the bh forums
> http://bottlehead.com/smf/index.php?topic=9029.0
> ...


 
 It's obvious to me. The long input wiring that goes from the RCA to the Attenuator isn't braided correctly. When it isn't braided correctly those long wires become an antenna and it picks up interference from the power supply. Unsolder it and buy some solid core wires and braid them correctly. It looks like the previous owner just twisted all 3 together which is incorrect.
  
 It looks like you make cables for headphones so I guess you already know but this is a nice video on how to get a good braid.


----------



## q2klepto

audiojun said:


> It's obvious to me. The long input wiring that goes from the RCA to the Attenuator isn't braided correctly. When it isn't braided correctly those long wires become an antenna and it picks up interference from the power supply. Unsolder it and buy some solid core wires and braid them correctly. It looks like the previous owner just twisted all 3 together which is incorrect.
> 
> It looks like you make cables for headphones so I guess you already know but this is a nice video on how to get a good braid.


 
  
 Ah youre right - i really didnt pay attention to the braids, only the solder joints and voltages.  So your crack w/ sb is dead silent with stock tubes?


----------



## ClintonL

Has anyone tried both the valhalla 2 and the crack + speedball for hd800's?


----------



## audiojun

q2klepto said:


> Ah youre right - i really didnt pay attention to the braids, only the solder joints and voltages.  So your crack w/ sb is dead silent with stock tubes?




Yeah stock tubes should be fine if it's only a hum, hums are from the power supply. I had a stock power tube that went bad after a lot of use and it was a ringing oscillating sound and it went away when I tapped the tube. Tapping on the tubes to see if noise changes is a good way to check.


----------



## ScottFW

q2klepto said:


> And here's an album of the insides
> 
> Http://imgur.com/a/PKrwL


 
  
 In addition to the signal wire being properly braided, the bodies of the RCA jacks are supposed to be insulated from the chassis plate. On yours the plastic washers have been installed incorrectly (with a metal nut between washer & chassis) so the jacks are not isolated from the chassis.


----------



## audiojun

scottfw said:


> In addition to the signal wire being properly braided, the bodies of the RCA jacks are supposed to be insulated from the chassis plate. On yours the plastic washers have been installed incorrectly (with a metal nut between washer & chassis) so the jacks are not isolated from the chassis.




I think that's fine, the Rca ground wire should be grounded to the chassis the l r signal wires are isolated inside the jacks.


----------



## q2klepto

scottfw said:


> In addition to the signal wire being properly braided, the bodies of the RCA jacks are supposed to be insulated from the chassis plate. On yours the plastic washers have been installed incorrectly (with a metal nut between washer & chassis) so the jacks are not isolated from the chassis.


 
  
 Yup that is correct - the RCA chassis were incorrectly mounted, it was pointed out by Doc and another user over at the BH forums.  Thats fixed now, voltages look good but i get a slight static/noise floor...was attributing it to the stock power tube..but now maybe the RCA is picking up some EMI from my computer
  
 I'll have to redo the RCA wires.


----------



## ClintonL

Just pulled the trigger, anyone have any reccomendations on what tubes are the best for vocal trance/progressive house?
  
 Cheers


----------



## Solarium

clintonl said:


> Just pulled the trigger, anyone have any reccomendations on what tubes are the best for vocal trance/progressive house?
> 
> Cheers


 
 I found the best tubes for the money to be the TS5998 or TS6080 with the CBS/Hytron 5814a input tube.


----------



## ClintonL

Having a tough time finding the CBS/Hytron tube, can only see 1 listing on ebay which only sell as a pair. At the moment thinking about the Mullard 12AU7.


----------



## Solarium

clintonl said:


> Having a tough time finding the CBS/Hytron tube, can only see 1 listing on ebay which only sell as a pair. At the moment thinking about the Mullard 12AU7.


 
 It just takes time. I found a perfect NOS CBS/Hytron for $20 shipped on ebay. For the price, nothing beats it, just like the TS6080.
  
 The Telefunken ECC82 is also very good, but it depends on your taste since it has an echo-like trail after the sound. It's very unique and pairs extremely well with certain music. I'm not sure if it works for fast paced EDM tho. I can't find the ribbed plates on ebay, but there's usually a few smooth plates available.
  
 Siemens ECC82 also very good, but more expensive. You have to look for the ones with the chrome/silver plates, instead of the usual matte metal plates which are cheaper. Cheapest you can usually find is $60 for a NOS. It makes the upper end more sparkly supposedly, so depends on your taste. The CBS/Hytron is still a much better deal.


----------



## Solarium

I'm surprised that the search button for "Elise" has not returned a single result. Is it prohibited on this thread to talk about that amp? 
  
 I'm just wondering if anyone has a good comparison between the 2, using good Crack tubes like the TS5998 and such, with the HD800.


----------



## ClintonL

No luck finding the CBS tube anywhere. Do you know any other decent input tubes around $30-40.


----------



## defbear

My Crack and Speedball kits arrived. Waiting for the weekend as they say.


----------



## ClintonL

Just got my crack and speedball and loving it. My Hd800's sound entirely different now. Only bad thing is it kinda smells like old. Kind of like your grandparents home. Guessing that's from the old tubes. Is there anyway you can get rid of that smell?


----------



## q2klepto

solarium said:


> I'm surprised that the search button for "Elise" has not returned a single result. Is it prohibited on this thread to talk about that amp?
> 
> I'm just wondering if anyone has a good comparison between the 2, using good Crack tubes like the TS5998 and such, with the HD800.


 
  
 Theres a Felik Elise thread on here somewhere 
  
 Here it is http://www.head-fi.org/t/782754/feliks-audio-elise-new-thread its ~700 pages long heh maybe theres some crack comparisons there
  
 A friend of mine on here has the Elise, been meaning to A/B my crack against it but havent had a chance


----------



## ScottFW

clintonl said:


> Only bad thing is it kinda smells like old. Kind of like your grandparents home.


 
  
 It could be that your tubes were previously used in gear owned by a cigarette smoker. Try cleaning the glass with some acetone on a rag or piece of paper towel, and see if a slight brown film comes off. Obviously, avoid wiping any paint if you want the logos to stay intact.


----------



## Maxhawk

clintonl said:


> No luck finding the CBS tube anywhere. Do you know any other decent input tubes around $30-40.


 
  
 Although the bias will be non-optimal, I recall prior to making resistor changes the RCA 12BH7 black plate was an improvement over the 5814.


----------



## attmci

clintonl said:


> No luck finding the CBS tube anywhere. Do you know any other decent input tubes around $30-40.


 
 amperex 7316, CV 491, TS smoke 12au7.


----------



## heliosphann

solarium said:


> I found the best tubes for the money to be the TS5998 or TS6080 with the CBS/Hytron 5814a input tube.


 
  
 I use Bendix/Chatham 6080WB and a CBS/Hytron 5814a for my HD800. Great pairing.
   
 Quote:


clintonl said:


> No luck finding the CBS tube anywhere. Do you know any other decent input tubes around $30-40.


 
 I really like the RCA Command black plate 5814a's. Great sound for the price.


----------



## ClintonL

I've got a Raytheon 6080wb. Would upgrading to a bendix or chatham 6080wb make a noticable difference or should i just go 5998?
  
Cheers


----------



## Tom-s

Depends. For me, the upgrade from a normal raytheon 6080wb to the "tested by Bendix" version was a real upgrade.
 From that one to the Bendix (solid) 6080wb wasn't a real change.


----------



## ClintonL

What did you notice changed after upgrading to the bendix one?


----------



## Tom-s

Even more details plus a better defined and more pronounced bass were the most noticeable improvements. I paid 15€ for the 6080WB Raytheon "tested by Bendix" and 40€ for the Bendix. For that money, it's worth it.


----------



## Solarium

solarium said:


> Any comparisons of the Crack-a-two vs the Crack w/ speedball yet?




Does anyone own a Crack 2? I'm debating whether to upgrade to that or the Elise.


----------



## ClintonL

Where'd you get the tested by bendix one btw? Can't find one on ebay.


----------



## larcenasb

I was reading page 205 of this thread, about padding the volume pot for more breadth and fine-tuning of the volume. I just want to get this right before I start soldering. Anyone with experience, I'd really love to get your affirmation and any tips. Thanks!
  
 http://www.goldpt.com/mods.html
  
 I don't have experience reading schematics, but from what I'm seeing from the link: in order to pad my Alps Blue Velvet 100K pot to get -20db of attenuation and not change the input impedance, I should, 1.) de-solder the wire from the "in" of the pot, 2.) solder an end of an 82.5K (1/2W okay?) resistor to that wire, 3.) solder the other end of the resistor to the "in" terminal of the pot and also to an end of a 10K (1/2W?) resistor, then 3.) solder the other end of the 10K resistor to the ground terminal of the pot. And do this separately for each channel. Is this correct? Thanks so much!


----------



## ScottFW

^^^ Sounds like you've got the right idea. I also have the Blue Velvet 100K pot and usually stay towards the low end of the range w/ HD650s, I just never felt like padding the input since mine measures very evenly between both channels even at the low end of its range.
  
 1/2 watt resistors are overkill, 1/8 W will do fine, and the Vishay / Dale RN55 series are an inexpensive and sonically neutral option.


----------



## larcenasb

Thanks ScottFW.  Although, I already have 1/2W resistors. That's okay right? Or should I buy the 1/8W? Thanks again for your help. Take care.


----------



## ScottFW

By all means, use 1/2 watt if that's what you already have, it's no problem.


----------



## deserat

Step one.  Crack meets Acid and Bath Salts.  ( ok, the only salts I actually had in the house were himalayan pink )


----------



## larcenasb

In the process of upgrading my crack further. I want to replace the last capacitor in the power supply, I have a question though:
  
 What should yield more benefit, a 1000uF 250V electrolytic (from BHC or Rifa) or a 220uF 250V film capacitor (from Solen)? And why? 
  
 They're about the same size, thanks for your time.


----------



## grausch

Based on my understanding, higher capacitance may lead to more bass, but the Crack is already pretty well optimised, thus most of the uF above 220uF may not have any effect (other than the caps taking longer to discharge). There is some math on the Bottlehead forum which will allow you to calculate the corner frequency (I believe it is called this) and Paul Joppa has commented more than once that the final PS cap is part of the audio chain. My own interpretation would be that changing the capacitance on the final PS cap may lead to more / less bass. However, my understanding of this is purely based on forum discussions, so take it with a grain of salt.
  
 Almost everyone believes that film caps offer a genuine sonic improvement, thus it may make more sense to go for the film.
  
 My own build has the first 2 PS caps upgraded to 470uF electrolytic caps and I have a 270uF film cap as the last cap. Tough to say if there are any improvements since A/B comparisons are tough to make while working on the Crack. However, due to the increased capacitance, the audio takes about 7 seconds before it fades out once I switch the power off.


----------



## tomb

Sorry - just saw this in passing.  The corner frequency has nothing to do with caps in the (Power Supply) PS.  The corner frequency occurs because the impedance of a pair of headphones combines with the amplifier's output capacitors to form an RC circuit.  An RC circuit, depending on configuration, will filter out certain frequencies.  In the case of output capacitors on a DAC or headphone amp, they filter out bass.  The circuit phenomenon is dependent on the values of R (the headphone impedance) and C (the output capacitor).  Increase either one and it will move the "corner" of where the bass has dropped by -3dB further down in the frequency range.
  
 For instance, if you combine a 32 ohm headphone with an amp that has 220uf output capacitors, you will lose some bass.  With a headphone of 300 ohms, 220uf capacitors will push the bass drop below 20Hz so you won't hear any lack of bass.  That's one of the reasons (among others) that people say OTL amps are bad for low impedance headphones.  You can up the size of the output capacitors, but they are typically very large and expensive at the high voltages of a tube amp.
  
 In terms of a PS, a film cap may be there specifically to tame higher-frequency transients (hash or even preventing oscillation) that may be coming off of the power supply.  Film capacitors have little to do with removing ripple and hum - that is performed by the electrolytic(s) in the power supply.  Replace the film cap with an electrolytic and you may be increasing the power supply noise, not improving it.


----------



## larcenasb

Thanks *grausch*, yeah I use 600ohm AKG K240s, the bass is just fine on mine.  But I've read others who've replaced the caps with higher uF caps and saying power delivery increases and background is blacker. Did you notice that at all?
  
 Thanks for the thorough explanation *tomb*! I understand better now. However, did you mean "Replace the _electrolytic_ cap with a _film cap_ and you may be increasing the power supply noise, not improving it."? Based on what you said about film caps having nothing to do with removing ripple and hum, that makes sense -- was that a mix-up?
  
 So, my understanding now is that electrolytics are important in a PS to remove ripple and hum, so replacing them with film outright is not a great idea -- but bypassing with film is good as it can add a bit of smoothness to the de-rippled and de-hummed signal. Is that fair to say?


----------



## mcandmar

Larger capacitance can reduce the ripple level by smoothing out the 50 or 60hz mains frequency of the power supply, which translates into less audible hum. A stock crack does a perfectly acceptable job of this so adding more capacitance isn't really going to do anything for you. If anything it may be a disadvantage as you are putting more of a strain on the power supply having to charge up such a large reservoir, especially on startup. IMO a 1000uf 250v capacitor is way too large and not really suitable for this application. If you did want to filter more hum there are much better ways to do that instead of bulk capacitance, i.e. use chokes in the power supply, or add another resistor and capacitor stage to the power supply.
  
 All capacitors have a bit of resistance and inductance, a film capacitor is closer to a perfect capacitor in that it has much lower values of each than an electrolytic capacitor. In theory using a 220uf film cap could give better high frequency response and dynamics, but i stress the "theory". I used a Solen 220uf film cap in my crack, and honestly i cant say if it does make a difference or not.
  
 A 220uf electrolytic and a 220uf film cap with do roughly the same job at smoothing ripple in a power supply. I think what tomb is referring to is small value film caps that are commonly used in circuits to target certain frequencies, which isn't applicable to a stock crack circuit.
  
 In short the big electrolytic is a bad idea, the film cap may be an advantage, but i really don't think its worth the cost. I would buy a nice set of output caps or tubes instead


----------



## grausch

larcenasb said:


> Thanks *grausch*, yeah I use 600ohm AKG K240s, the bass is just fine on mine.  But I've read others who've replaced the caps with higher uF caps and saying power delivery increases and background is blacker. Did you notice that at all?


 
  
 Can't say I did. My stock Crack was pretty damn good with absolutely zero issues. My biggest issue was when I rebuilt the Crack and had a flaky solder at at T13 which is one of the legs of the final PS cap. That made the Crack sound flat and is why I believe the last PS cap influences the sound, although tomb's and mcandmar's explanations are most probably correct and mine not.


----------



## larcenasb

Thank you *grausch* and *mcandmar*, I definitely learned a lot from your answers! I bought Cree Schottky diodes for the power supply and will now plan to get Dayton 100uF 250V output caps. Later on, maybeeee I'll get Mundorf 220uF electrolytics for the power supply just for kicks.  Thanks again for your time and help. Happy listening and take care!


----------



## larcenasb

*mcandmar*, could you please elaborate -- I'm trying to be thorough before I set my mind on a judgment about the power supply caps. I've been reading older threads and getting a lot of conflicting info. When you say, _"__i__f anything it may be a disadvantage as you are putting more of a strain on the power supply having to charge up such a large reservoir, especially on startup,"_ what exactly might happen to the power supply? Please explain.
  
 Food for my jostling thought on the subject:
  
 1.) Paul Joppa, of Bottlehead, said, 
  
_"The output audio current flows through the power supply, mostly the last capacitor, as well as through the output coupling cap and the output triode. So the final power supply cap should, in theory, be as important as the output coupling cap with regard to the sound of the amp. This is a characteristic of cathode follower circuits, such a the Crack and the Foreplay." _
  
 Later, he went on to say, *after a member said he liked the difference using a higher uF cap*,
  
_"__I post this with some frequency: 'I never met a power supply improvement that was not also a sonic improvement.'__"_
 [from the Bottlehead Forum thread, 'Upgrading the power supply capacitors in the Crack,' page 1, replies #4 & #9]
 

2.) Grainger49 said, in response to a member's usage of 1x 1000uF and 2x 470uF PS caps,

_"__Wow, I like a lot of big capacitors! There are a number of engineers here and they would also suggest more power supply capacitance and a choke in the power supply filter.__"_

[from the Bottlehead forum thread, 'A Crack Across the Ocean,' page 1, reply #7]

 Concluding questions:

 - Is it then in fact safe to use a 1000uF cap in the power supply of the crack?

 - Apart from smoothing ripple and filtering hum, is it possible for a larger electrolytic in the PS to affect dynamics and power delivery?

  

 Thanks and take care!


----------



## ScottFW

larcenasb said:


> I bought Cree Schottky diodes for the power supply ...


 
 You have a board to mount those on? I'm pretty sure those only come in a TO-220 package, so would require some bending of the legs to mount them to the stock terminal strips without an adapter board (I used the one from... Parts Connexion I think it was?). Also, the mounting tabs on those are electrically live so take some care that they don't touch anything else under there.


----------



## larcenasb

Hi again ScottFW! Yes, I ordered from Parts Connexion too. I saw how others installed it on that board. I'll post pictures once mine is all set up!
  
 P.S. About the heat concern, I was thinking of some way to cage the board and diodes, still thinking about a solution.


----------



## Tom-s

Mine are just mounted in free space on the stiff short wiring. I've never noted any heating issues.


----------



## JamieMcC

Rather than go for a big expensive 220uf film for the last power cap you can replace the last resistor with a $15 choke and use a less expensive 50uf -100uf film cap instead the smaller cap will be easier to fit in and The C-7X choke is probably the best value upgrade for the Crack the difference it makes is clearly audible. This would be my own prefered option and gives more bang for your buck its also a straight forward mod thats well documented on the BHF.
  
 http://eu.mouser.com/ProductDetail/Triad-Magnetics/C-7X/?qs=%2fPiZ59IM4y3T0O8Zu9aP3g%3d%3d


----------



## larcenasb

Thanks *JamieMcC*, I'm trying to weigh the pros and cons before I decide on which route to take. How do you think the choke ($20) and a 100uF film cap ($30 for a Dayton) would fare against a 1000uF Nichicon KX electrolytic ($8)  bypassed with a 10uF Mundorf Evo aluminum + oil ($20).
 Can you explain what the advantages and differences would be of each route? Thanks!


----------



## larcenasb

And thanks *Tom-s*, I'll not worry about the diodes!


----------



## JamieMcC

larcenasb said:


>


 
 From my understanding and experiences I have found film is preferable sonically to electrolytic for anything the signal passes through.  Also I am pretty sure I have seen mentioned on the Bottlehead forum by one of the team that there is the potential when fitting an overly large value electrolytic a chance of damaging the diodes and over taxing the transformer.
  
 As an exaggeration think of the transformer as a tap filling a bucket (capacitor) up when there is no load the tap has time to fill all the buckets fully as the last bucket (the third cap) is put under load and emptied its contents is topped up from the two dc smoothing reservoir capacitors before it and the transformer tops up the first.  With equal values the 220uf can do this easily but if you swap the last cap with higher values such as the 10000uf it’s going to put a strain on the components before it including the transformer supplying the.
  
 Another option would be to go with the choke but keep the 220uf electrolytic and bypass it with a Russian Teflon or small film bypass, examples of both on the BHF.
  
 Having done it a couple of times now fitting a choke and a standard mkp 50-100uf film cap is going to make a very noticeable improvement. It would be a must do mod for me if building a Crack again.


----------



## Jeb Listens

I agree with Jamie - I found replacing the last electrolytic with a film cap a very worthwhile exercise - perhaps slightly less impactful than doing the output caps but still very good, especially when it comes to producing a smoother more natural treble presentation. 
  
 I used the choke and a 100uf/250v film cap.   Previously I tried bypassing the last electrolytic with a selection of different small film caps and found that they all changed the sound but not in any way that I liked.  For my preferences and gear, that was a backwards step. 
  
 After I had replaced it altogether with a film, I then tried bypassing it and found that to be a positive step forward.  By that point I had accumulated some quite nice small caps so used a jupiter cap, which is probably overkill - but I really like the results. 
  
 In my experience, bypassing caps really requires a bit of experimentation - you can do this carefully with some suitable clip leads before finding what works for you and soldering into place. 
  
 I found the cree diodes to be a really nice upgrade too -especially for the money (~£10).  
  
 After going through the modding process, one thing I would recommend is that if your plan involves drilling the top-plate multiple times,   gather all your components, decide on the layout then do all the drilling in one go.  It gets pretty tight in there.


----------



## Tom-s

larcenasb said:


> And thanks *Tom-s*, I'll not worry about the diodes!


 
 As you see in my picture. The only thing i did was tape the top plate with for insulation right under the diodes. Just in case they'd ever touch the top plate.
  
 I'm currently reviewing my film cap options as wel. For now the 220uf Ansar looks like a great option costing about 60€ shipped 82mm long and 60mm diameter. Any other "small" and cheap options? (diameter is the limiting factor in my case)
 Please remember that the last film cap is in series with the output capacitor. So unlike grausch suggested it actually does influence the capacitance seen by the headphone.
  
 Edit: http://suppression-devices.com/ansar/index.html


----------



## larcenasb

Thanks for all the replies. And that's a great analogy JamieMcC, that helps a lot!
  
 In the Bottlehead forum thread, 'Choking the Crack," Paul Joppa said,
 "I would never use less power supply capacitance (last cap) than in the output cap, and I'd prefer at least twice that - if it were my amp."
  
 But how come with the choke the capacitance can be lowered? *And how low is okay?* I saw Mikey on the Bottlehead forum use a 22uF Solen cap and Doc's green crack looks like it uses a 100uF Audyn cap. I'm learning a lot, thanks


----------



## Tom-s

http://www.duncanamps.com/psud2/


----------



## JamieMcC

Basically a choke is hundreds of times more efficient at reducing the ripple but it costs a thousand times more than a resistor so if a choke is used then last capacitor doesn't need to be so big to get the same end value results.
From memory as a example I think the stock crack power supply has a ripple of 1.5mv or 1500uv when using a choke the final capacitor only needs to be around 22uf to achieve the same result but here using a say a 100uf capacitor will reduce the ripple to 150uv so a massive reduction in ripple is noise floor which is perceived as a blacker background and increased resolution and improved dynamics such as bass impact. I am sure there is much more to it but essential that is my limited under standing. using my phone to reply has been exceedingly frustrating grrr


----------



## larcenasb

jamiemcc said:


> Basically a choke is hundreds of times more efficient at reducing the ripple but it costs a thousand times more than a resistor so if a choke is used then last capacitor doesn't need to be so big to get the same end value results.
> From memory as a example I think the stock crack power supply has a ripple of 1.5mv or 1500uv when using a choke the final capacitor only needs to be around 22uf to achieve the same result but here using a say a 100uf capacitor will reduce the ripple to 150uv so a massive reduction in ripple is noise floor which is perceived as a blacker background and increased resolution and improved dynamics such as bass impact. I am sure there is much more to it but essential that is my limited under standing. using my phone to reply has been exceedingly frustrating grrr


 
 Haha, well thanks so much for taking the time to help me out  I think I will get the choke and three Dayton 100uF 250V caps then bypass the PS cap w/ a nicer film cap. I'll post pictures when I'm done! And thanks, *Tom-s*, I'll play with that software a bit to understand further!


----------



## ClintonL

Anyone know where to find tubes which will ship internationally to Australia?


----------



## Demoninja

Hey everyone so I upgraded my pot to a Valab 23 step attenuator and the knob no longer sits flush with the top plate. Anyone know where to buy another one that fits better or have any specific recommendations?


----------



## JamieMcC

demoninja said:


> Hey everyone so I upgraded my pot to a Valab 23 step attenuator and the knob no longer sits flush with the top plate. Anyone know where to buy another one that fits better or have any specific recommendations?


 
  
 If you adjust the fixing nuts on the Valabs shaft you can get it to sit flush, I had no problem with mine.


----------



## mcandmar

If you only have one nut just add a few washers on the bottom side to fill the gap.  In some cases where the shaft is still too long (Alps Blue) you just have to shorten it.


----------



## Demoninja

Thanks you two, that makes infinitely more sense than what I thought I had to do aha. One more dumb question, I'm trying to find a right angle power cord, can I just buy this one from Monoprice or is there anything I need to look into before I get it. http://www.monoprice.com/product?p_id=7681


----------



## Mingus Ah Um

demoninja said:


> Thanks you two, that makes infinitely more sense than what I thought I had to do aha. One more dumb question, I'm trying to find a right angle power cord, can I just buy this one from Monoprice or is there anything I need to look into before I get it. http://www.monoprice.com/product?p_id=7681


 
 I believe I have the same one...been using it for 2+ years with no problems.


----------



## Tom-s

Anyone considered using chinese motor run oil caps? 3 of these 50uf would make a good last PS cap. Ok, they are bigger but in my case it would fit.
 http://www.ebay.com/itm/CBB65-450VAC-50uF-5-Refrigerator-Non-Polar-Motor-Run-Capacitor-/231132290872?hash=item35d08edf38:g:VSAAAOSwDNdVlVOZ
  
 Any concerns? Would it be a worthwhile upgrade of the standard PS caps?


----------



## spacequeen7

nvm


----------



## JamieMcC

tom-s said:


> Anyone considered using chinese motor run oil caps? 3 of these 50uf would make a good last PS cap. Ok, they are bigger but in my case it would fit.
> http://www.ebay.com/itm/CBB65-450VAC-50uF-5-Refrigerator-Non-Polar-Motor-Run-Capacitor-/231132290872?hash=item35d08edf38:g:VSAAAOSwDNdVlVOZ
> 
> Any concerns? Would it be a worthwhile upgrade of the standard PS caps?


 
  
 Motor runs for the last cap and the signal caps worked out well for me when I tried some 89uf Epcos motor runs in my Crack.
  
 Have a good look round there are some interesting options about, something like in the link below might be easier to fit. Also have a look on Aliexpress you can often find film caps at really great prices for odd values but it takes a bit of searching around that's where I found the ones I used in the pic, just checked and they were 5 for $28.30 delivered!
  
 http://www.ebay.com/itm/2PCS-50uF-850V-Vishay-MKP1848-DC-Link-Filtering-Polypropylene-Film-Capacitors-/351683467304?hash=item51e1f7d828:g:1oIAAOSwa81XRoBr


----------



## chiggah

What is the recommended usage hours per day for the Crack ?

 Would it be suitable for gaming, and turning the crack on for 8-12 hours per day ?


----------



## JamieMcC

chiggah said:


> What is the recommended usage hours per day for the Crack ?
> 
> Would it be suitable for gaming, and turning the crack on for 8-12 hours per day ?


 
  
 No problem keeping it running all day just make sure the base of the Crack is clear to allow for ventilation. I left mine on for a week once.


----------



## Tom-s

Thanks for the reply Jamie. Had a look around for those EPCOS but couldn't find any.
 Decided on 2x 730uf RIFA's for the other PS caps. A pair of those EPCOS would be perfect for the last PS cap.


----------



## larcenasb

Please help -_-
  
 I just tried installing Cree Schottky diodes today but when I power up my amp, nothing happens now. No sound, tubes don't even glow, and no heat coming from the amp at all.
  
 I removed all the stock diodes, and the two wires (from 18 & 19) leading the diodes to the power supply. I then followed others' pictures to guide me. If anyone has done this mod, could you please look over my work and maybe see if I'm missing something? Thank you so much.
  
 I checked my solder joints, tried different tubes, checked the fuse, tried a different power cord, plugged into a different socket, shook the top plate to see if any wire ends or solder were loose anywhere...
  
 Here's where I bought the parts: 
 http://www.digikey.com/product-search/en?mpart=CSD01060A&v=90
 http://www.partsconnexion.com/product26996.html


----------



## larcenasb

FIXED IT!! B6 happened to become unsoldered! Reheated to let the solder flow, then powered up the amp ...that glow was so relieving! Thanks to anyone who may have been taking the time to write something to help me.
  
 Now, take for granted how elated I am to even have sound (lol), but the Cree Diodes definitely make a difference in effortlessness -- more spacious sound, separation more clear, depth increased noticeably! After a little while, I'll install my c7x choke. I'll post more pictures when done!


----------



## larcenasb

Cree Shottky diodes definitely give the sound more depth and separation. The C-7X choke furthers even more depth. For example, my 6080 tubes no longer sound so constricted compared to my 6AS7G. Tomorrow I should be getting my Audyn Q4 68uF film caps! I only use 600ohm AKGs so 68uF should be fine. Will post impressions tomorrow, right now the bass in Ray Charles voice when he says "OhHHHHHhHH" at the beginning of 'Ev'ry Time We Say Goodbye' is very resolute, very gutsy -- effortless and unmechanical sounding.  Happy listening!


----------



## larcenasb

Finished some upgrades today!
  
 Prolonged listening last night made me realize the C-7X choke gives an improvement in detail, and the sound has a brighter signature compared to the stock resistor it replaced. Seems similar to the changes a Tung-Sol 5998 makes compared to the sound of the Sylvania GB6080 and RCA 6AS7G. Also, before, when the volume pot was maxed -- without music -- there was some hum and scratchiness, and now, with the C-7X, it's gone. No music and maxed volume makes me imagine I'm wearing a lab coat in a clean room. I'm happy with this new horizon of clear and clinical sound, but I kept thinking and hoping for nightfall and tomorrow, as I imagined my Audyn film caps being loaded into the local USPS truck. I've been using Mallory 100uF electrolytics, though I couldn't tell a difference from the stock caps.
  
 And here we have another new day! I got my Audyn (Q4 68uF 400V) caps! 
  
*OUTPUT CAPS*: I've read from others saying they _might_ have noticed a difference with their new film output caps but, for me, these caps made an obvious difference in tone, smoothness, and body. I can turn up the volume higher and it doesn't get as harsh and mechanical sounding as before. Highs are still far-reaching and clear but now have a purity and roundness in their demeanor. Sounds very high class. Notes come and go with poise.
  
*LAST PS CAP*: The third Audyn cap in the last PS cap position reinforces the output positions' smoothness, purity, and poise. I'm very, very happy. This is less obvious, but it seems there's more weight to the sound.
  
*MORE NOTES WHILE LISTENING*:
 - Tube rolling, for me, is no longer as important as before. I can live with any of my tubes really, but my favorite 6SN7s of course make it that much better.
 - I keep thinking about how poised the notes present themselves as they fall into place one after another. It's like they discussed the game plan of each song and movie soundtrack and have practiced their execution unendingly. I keep signaling each note's landing by waving my hand in the air and swooning like a conductor.
 - During research, before hitting the "submit order" button, I really hoped there wouldn't be any downgrade with 68uF caps in place of 100uF ones. And there is none. The fact that it's a film cap is the important factor here -- as is my using 600ohm AKGs. In fact, bass is more forceful with the 68uF Audyn's, and reaches deeper. Also, bass lines are noticeably more distinct as are the other instruments and voices. So I can focus on one instrument or vocal but _I'm not forced to_ -- meaning the sound is still coherent and musical, it's not matter-of-fact and strident like Christopher Hitchens at his best. It's classy and honest, always seeming to beautifully deliver the right answer ...like Christopher Hitchens at his best.
 - I remember reading someone else's impression that film caps take away hash and glare (or schreechiness) from the treble, and I would agree; that's another way to explain what I said was smoothness and purity in the sound.
 - Overall, I'm very happy! Here are some pictures! Cheers and happy listening!


----------



## cddc

j123my said:


> Whohooooooo~ I have just finished building my crack + speedball this morning. And it sounds aweeeessoommeeeee!! :atsmile:
> 
> Highs are crystal clear, mids are sweet, and bass, oh the bass is sooo tight and warm. Soundstage is, too, amazing. Feels like listening to a live concert  . My HD600 has never sounded this good before.
> 
> Is it weird if I enjoy looking at my crack? I smile every time I flip the chassis over, maybe somewhat proud that I have built this baby with my own hands..





whooooohooooo, beautiful!!!

Is this build going to take more wire to build? I am asking the question because I want to use some left-over wire to set up the fly leads for the cap upgrade. Not sure if this customized build would leave me with enough wire for the fly leads?

Thanks a lot!


----------



## Tom-s

There's plenty wire in the normal kit. I think you can do all the known mod's and still have some left.


----------



## Valhallatier

Guys my crack started to make a hissing noise on both channels ( first start with right, 1 second later left) right after 10 seconds of turning it on. It was fine pretty much the entire time until this time a power outtage that's like a split second took in, but nothing got turned off. But then my crack started to hiss like white noise playing. I change power outlet, tapping it, RCA cables... still there. I need help


----------



## Tom-s

Do a pin prick test and swap tubes. A voltage check might give some extra insight.


----------



## Tom-s

Any experiences using Herbie's tube dampers with Crack (with normal tubes and microphonic ones)?


----------



## deserat

Finished my Crack.  Haven't done the speedball upgrade yet, am running the Tung Sol 5998. I can say it compares favorably with my HDVA600. Using both the HD600 and HD800.  It's not quite as detailed but it certainly brought that tube magic back into my life. For the HD600 I'd buy the Crack over the HDVA for the HD800, well it looses some of the imaging and mirco detail, but still a wonderful amp.
  
 Backed by a Schiit Gumby.


----------



## JamieMcC

Just a heads up I noticed a seller on ebay has a bunch of 7236 Cetrons for a fair price, just picked a couple myself
  
 http://www.ebay.co.uk/itm/172228954065
  
 From the Multi 6as7g review
  
*"II.a.iii) [RARE]* *$75 (NOS) Cetron/Tung Sol 7236 [Dual Halo Getters]*:

 The 7236 is a computer rated 5998A but should sonically sound similar to the 5998. This specific 7236 has zirconium coated grey box plates. Similar to the 5998 sound abeit more linear, tighter bass and more dynamic. Basically a "faster and controlled" 5998 but at the expense that the bass doesn't go as deep. This tube is glorious listening to vocals and is probably the most controlled and "best" mid-centric tube of the 5998 pack.

*II.b) The Bendix 6080WB Graphite Plates*
 Unlike all other 6AS7 tube types, these had solid graphite COLUMNS and not plates and are very heavy duty. They have ruggedized construction features such as extra supports and copper posts not found on other 6080 tubes. Regardless of branding, these were all manufactured by Bendix. These are a really good buy and an excellent alternative to the 5998"
  
 http://the-key.enix.org/~krystal/review-tube-bottlehead.html


----------



## mitchmalibu

Thanks for the heads up, order a couple too, should make a good step up from the stock one with my hd700 (as I understand, the 5998 is better with lower impedance HP).


----------



## Walderstorn

larcenasb said:


> Finished some upgrades today!
> 
> Prolonged listening last night made me realize the C-7X choke gives an improvement in detail, and the sound has a brighter signature compared to the stock resistor it replaced. Seems similar to the changes a Tung-Sol 5998 makes compared to the sound of the Sylvania GB6080 and RCA 6AS7G. Also, before, when the volume pot was maxed -- without music -- there was some hum and scratchiness, and now, with the C-7X, it's gone. No music and maxed volume makes me imagine I'm wearing a lab coat in a clean room. I'm happy with this new horizon of clear and clinical sound, but I kept thinking and hoping for nightfall and tomorrow, as I imagined my Audyn film caps being loaded into the local USPS truck. I've been using Mallory 100uF electrolytics, though I couldn't tell a difference from the stock caps.
> 
> ...


 
  
 How much did u pay for those caps?


----------



## ClintonL

jamiemcc said:


> Just a heads up I noticed a seller on ebay has a bunch of 7236 Cetrons for a fair price, just picked a couple myself
> 
> http://www.ebay.co.uk/itm/172228954065
> 
> ...


 
  
 How would this compare to rayethon 6080wb's which i'm running? Would i get a notable difference?


----------



## larcenasb

walderstorn said:


> How much did u pay for those caps?


 
 They're only $16.70 ea. on Parts Express!


----------



## JamieMcC

clintonl said:


> How would this compare to rayethon 6080wb's which i'm running? Would i get a notable difference?


 
  
 Hi have a read through the Multi 6as7g review all the info you will ever need on the top tubes for the Crack are in it.
  
 The review is clear that the 7236 has similarities to the premium 5998 and it is listed just ahead of the hard to find Bendix 6080 slotted plates both are highly sought after for their sonic presentation and because of this generally cost around three times the price the 7236 are being offer at.
  
 I would expect you would notice a difference switching from the Rayethorn but obviously it will depend on what your personal preferences are as to if you like those differences. Try asking for some opinions over on the 6as7g rolling thread.
  
   http://www.head-fi.org/t/410326/for-6as7g-tube-rollers-here/3615#post_12634863
  
 Multi 6as7g review
  
http://the-key.enix.org/~krystal/review-tube-bottlehead.html


----------



## Walderstorn

larcenasb said:


> They're only $16.70 ea. on Parts Express!


 
 Is there a particular side i should solder or its the same if i solder one way or the other way around? I didnt make my crack so im not really into it but would like at least to change capacitors.


----------



## cddc

captouch said:


> Pictures of my recent build. . .
> 
> Underside, currently stock.
> 
> ...





really like the paint on the top. what is the paint? where can i find it? thanks a lot


----------



## captouch

cddc said:


> really like the paint on the top. what is the paint? where can i find it? thanks a lot




Thanks! It's Rustoleum Universal Metallic Oil-Rubbed Bronze. I got it at Ace Hardware, but I'm sure Home Depot or Lowe's has it too. 

If you can't find it, I can take a pic of the spray can - I think I still have it a around.


----------



## Doc B.

> Would try wood conditioner next time to smooth out the staining, and tape the edges where the glue could overflow and touch since that affects stain absorption.


 
  
 The trick with the glue is to have a damp rag ready to wipe off anything that squeezes out of the seam. Also, water based aniline dye from woodworking specialty stores works a lot better than most of the big box store stains.


----------



## DavidA

doc b. said:


> The trick with the glue is to have a damp rag ready to wipe off anything that squeezes out of the seam. Also, water based aniline dye from woodworking specialty stores works a lot better than most of the big box store stains.


 
 Learned this from my dad many years ago when I was helping him to build custom furniture, usually made out of koa wood


----------



## cddc

Thank you very much, captouch! I have found the paint in home depot


----------



## cddc

ffivaz said:


> I just finished my BH Crack a week ago. I didn't have any problems with building it, even if it was my first DIY project (except a non-working 6080 tube that I replaced). The guys at BH really helped me sort out the problem (thanks Doc). It sounds really good with my HD 650 and my 600 Ohms Revox RH 310 (reviewed here). And I just can wait to start rolling tubes, and maybe some day go for the Speedball !
> 
> Here are some pictures.
> 
> ...




The base looks pretty clean and nice. How did you treat the wood? What paint or stain did you use? Thanks a lot


----------



## cddc

flysweep said:


> Speedball'ed Crack (with Alps RK pot & Erse X-Pulse output cap upgrades) just arrived.  Lovingly built by Jeremy (j23my).
> 
> Running Tung-Sol 5998, a NOS Tungsram 12AU7 & using a Bottlehead power cord.  Only been listening for a short period of time.. I love it so far.. terrific match with the Fischer Audio FA-002w "High Edition" (pictured) & the HD800.  Feeding it with an ODAC.  Smooth, dynamic,
> clean, airy, very transparent, with just a touch of liquidity.  Impressive.





I like the look on this base as well. Can you guys shed some light on what kind of paint/stain it takes? I really don't know too much about wood work.


----------



## JamieMcC

cddc said:


> I like the look on this base as well. Can you guys shed some light on what kind of paint/stain it takes? I really don't know too much about wood work.


 
  
 One of the nicest and simplest and quickest ways of finishing a base and my personal favorite is to sand to 250 grade followed by a couple of applications of Tung oil. This is just wiped on with a cotton rag then left to dry in between coats, once dry its give a light rub over with some fine gauge wire wool followed by some ordinary wood wax and then a quick buff .
  
 This is how it ends up just letting the wood to the talking


----------



## cddc

jamiemcc said:


> One of the nicest and simplest and quickest ways of finishing a base and my personal favorite is to sand to 250 grade followed by a couple of applications of Tung oil. This is just wiped on with a cotton rag then left to dry in between coats, once dry its give a light rub over with some fine gauge wire wool followed by some ordinary wood wax and then a quick buff .
> 
> This is how it ends up just letting the wood to the talking






Great, thank you so much for the detailed steps, Jamie!

I do not have wood wax, but I do have some fine car wax. Will the car wax do the same trick?


----------



## mcandmar

I have built half a dozen that way on Jamies advice and they all looked fantastic with a silky smooth finish. Also far easier to apply than a clear coat.


----------



## JamieMcC

cddc said:


> Great, thank you so much for the detailed steps, Jamie!
> 
> I do not have wood wax, but I do have some fine car wax. Will the car wax do the same trick?


 
  
 I expect car wax would work just as well but have not tried it myself.


----------



## mcandmar

If its a natural carnauba based wax it should work just fine. A coat of Collinite lasts about six months on my car so it should last a few years on a crack


----------



## cddc

Thanks very much, Jamie and Mcandmar.

My AutoGlym High Definition car wax is a blend of polymers, Carnauba and microcrystalline waxes, combined with selected solid saturated hydrocarbons and oils. It works great on my car, hopefully it will work great on wood as well.


----------



## vintinfinity

I just ordered a used crack with a slight hum on one channel without music playing. Will reflow everything to see if that takes care of it. The guy who built it had never soldered before. So it could be easy to fix. If not, my pops is a retired tech and he will troubleshoot it for me.

Looking to get a 6sn7 adapter since I have some 50s or 60s RCA, GE and Sylvania tubes that tested well. also have a couple 12au7 RCA black plate tubes. Some labeled Conn, rca clear tops, and a few more with similar plates. Most of the labels got worn off by a friend that didn't realize they were like dust. Oh well. Should be fun tube rolling for awhile after I get it working. Especially when I get a Better output tube. 

http://m.imgur.com/a/oYWQN

And these 70s? Rca NOS 
http://m.imgur.com/a/A2fms 6sn7


----------



## Ryheg

is there any alternative site?
  
Block details 
Your IP: *xxx.xx.xx.xxx*
URL: *http://bottlehead.com/*
Your Browser: -
Block ID: *GEO02*
Block reason: Access from your Country was disabled by the site administrator.
Time: Mon, 13 Jun 2016 20:58:24 -0400
Server ID: *cp11004*


----------



## ClintonL

Just got my cetron 7236 linked a few pages ago. Loving it so far beats my raytheon 6080wb.


----------



## Aradea

You should provideur IP address to the admin and have him unblock it for you


----------



## vintinfinity

audiojun said:


> Take a picture of the internals of your crack.
> 
> Lots of reasons for hum I spent a while chasing that hum and fixing it.
> 
> ...




I'm not the person you were replying to, but I also picked up a crack amp with a hum on one channel with no music playing. Does the wiring look suspect in regards to the braiding for that. It was the builder's first time soldering as well. 

http://m.imgur.com/a/AKg0B

Also, one of the speedball boards doesn't work. They look a little messy to me.


----------



## i luvmusic 2

>


 
 Did your Crack catch on fire?


----------



## Feilong4

So I have an already built Crack with speedball coming in a few days and so I'd like advice as to the basics care-taking of a tube amp.
  
 I'm completely new to tube amps so some questions I have right off the bat are:
  
 -Is it safe to unplug the tube while the amp is still on (probably a very stupid question, but it's good to know for sure while I'm ahead)?
 -In what environment should tubes be stored in (like room temp, low humidity)?
 -How long is the average tube life and how do I know when it's time to get new ones?
 -How do you dispose of tubes that are no longer good to use?
 -Should tube amps be used in moderation as in so the amp won't overheat or something?
 -Is it possible/safe to use 2 tubes from different manufacturers?
 -Is one of the tube's function different from the other on the crack?
  
 Also, please also give other advice on anything I should know.

 Thanks!


----------



## deserat

i luvmusic 2 said:


> Did your Crack catch on fire?


 
  
 It did! I broke out a blow torch an smoked it up.  On a more serious note. Something about tubes reminds me of times gone by, and so I wanted my amp to look like it'd been pulled from a burnt down science facility or old barn or something. It's my first attempt a electronics, wood finishing, and metal work... and well I couldn't be happier.


----------



## i luvmusic 2

deserat said:


> i luvmusic 2 said:
> 
> 
> > Did your Crack catch on fire?
> ...


 
 It's unique....


----------



## John Q Lin

Hi guys, any suggestion on a amp to complement my grace m9xx. Thanks.


----------



## audiojun

john q lin said:


> Hi guys, any suggestion on a amp to complement my grace m9xx. Thanks.


 
  
 What price range?
  
 To drive all your current headphones? I guess project ember II in $350 price range or polaris for $250 or you can diy build a Torpedo I or III for an high end amp.


----------



## DavidA

john q lin said:


> Hi guys, any suggestion on a amp to complement my grace m9xx. Thanks.


 
 A little broad question but what headphones are you using?  If the ones listed in your profile then the BH Crack will work quite well for the HD-600 since you are asking the question in this thread.
  
 For the other headphones I would get the Ember as @audiojun suggested if looking in the under $500 range.


----------



## John Q Lin

davida said:


> john q lin said:
> 
> 
> > Hi guys, any suggestion on a amp to complement my grace m9xx. Thanks.
> ...


 

 I would like some thing that would drive the th900, T1, and hd650. I'm considering getting those in the future.


----------



## DavidA

john q lin said:


> I would like some thing that would drive the th900, T1, and hd650. I'm considering getting those in the future.


 
 Crack for the T1 and HD-650 (you will need to get better tubes than the stock ones), the TH-900 on your m9xx should be okay
  
 If you have more $$$ then the Elise or Torpedo III that @audiojun built are great for the under $1K range.
  
 I would also look at a better DAC than the one in the m9xx, the 2 times that I heard used as the DAC it was a little disappointing to me after reading about how everyone said that its great, to me it wasn't as good as the 4490 bifrost for about the same price but if you need portable then the m9xx is about as good as it gets, maybe Mojo better?


----------



## audiojun

john q lin said:


> I would like some thing that would drive the th900, T1, and hd650. I'm considering getting those in the future.




I Forgot to mention the Bottlehead sex to drive everything this is the crack thread after all. I'd also suggest going to a meet and then get something end game that suits you because it seems you have been going through a lot of headphones and upgrading your gear.


----------



## John Q Lin

audiojun said:


> john q lin said:
> 
> 
> > I would like some thing that would drive the th900, T1, and hd650. I'm considering getting those in the future.
> ...


 
 Your right. I have gone through a lot of headphones, I really enjoy the he500, maybe he6 could be my end game, and I like bass too maybe th900.


----------



## DavidA

john q lin said:


> Your right. I have gone through a lot of headphones, I really enjoy the he500, maybe he6 could be my end game, and I like bass too maybe th900.


 

 The BH SEX has been discontinued


----------



## John Q Lin

should I take a look at hd650, or pass,because he500 is consider a better hp. and I really like the he500


----------



## audiojun

john q lin said:


> Your right. I have gone through a lot of headphones, I really enjoy the he500, maybe he6 could be my end game, and I like bass too maybe th900.




HE-6 bass is incredible and so is everything else, you may not need the th900 if you get the HE-6. HE-6 is actually my end game too after hearing it at canjam.


----------



## John Q Lin

audiojun said:


> john q lin said:
> 
> 
> > Your right. I have gone through a lot of headphones, I really enjoy the he500, maybe he6 could be my end game, and I like bass too maybe th900.
> ...



He 6 is that impressive? I thought th900 was king of bass. Would you put He6 above T1, HD800, HD650, th900, lcd2 with all of them being well amp?


----------



## audiojun

The T1, HD800, HD650 are not really about the bass.

I never heard the th900 but usually closed headphones have more bass. The HE-6 bass is dynamic sounding and extends very low. It does have a draw back, it is very inefficienct, dr. hifiman said it's because the thin diaphragms require a lot more current to produce sound. Also the headphones are fast so the treble is also great and smooth sounding. It also sounds very neutral to me if you compare he-6 frequency response to HD-600 it seems to be more neutral than an HD600.

You need an amp centered around the HE-6 to get it to perform well and it will likely be one of the best performing headphone in the same league as a sr009, he1000, lcd-4 and hd800. I heard these headphones need 20 watts per channel to perform it's best, for comparison the HD600 just needs .2 watts. Amp requirements are putting me off on the HE-6 though I would've gotten it


----------



## DavidA

john q lin said:


> He 6 is that impressive? I thought th900 was king of bass. Would you put He6 above T1, HD800, HD650, th900, lcd2 with all of them being well amp?


 
 HE6 is impressive, but it sounds best run from speaker amps
  
 The HD-800 and T1 are very different sounding headphones from the others, they are designed for large sound stage and great details, the rest of your audio chain needs to be able to keep up with them.
  
 HD-650, LCD-2, TH-900 and also your HE-500 are more fun signatures, more musical to me.  While the TH-900 is good with bass its not the same as the bass from the HE6, not as tight or deep.
  
 I have a SR-009, TH-650, HD-800, T1, LCD-2, HD-650, HE-560, RS2e and a few other headphones but I use each for different genres of music but I also like hearing how each presents the different genres of music that I listen to, the way I look at it, use the right tool for the job.  If you like classical then the HD-800/T1 would be my recommendation, if you like R&B, Pop, EDM then the TH-900/600 or LCD-2, for jazz and blues the HD-600/650 or HE-560.  This is where finding an amp gets harder, what works great for the HD-800 will not work as well for the HE-560 so you have to think ahead if you don't want have to change amps all the time, or just have 2 or 3 amps to handle the range of headphones.


----------



## mitchmalibu

clintonl said:


> Just got my cetron 7236 linked a few pages ago. Loving it so far beats my raytheon 6080wb.


 
 Seconded. It really opened the mids for me, coming from the stock tubes.


----------



## JamieMcC

john q lin said:


> I would like some thing that would drive the th900, T1, and hd650. I'm considering getting those in the future.


 
  
  
  
 Look for a used Sex they are great value used imho.
  
 HD800 also is superb on the Sex not quiet at the level of the Mainlines performence but its very very good for a fraction of the cost.
  
 HE-6 is a amazing headphone I have tried it with quiet a few different amps but keep coming back to the little inexpensive Nelson Pass ACA (6W class A speaker amp) with a Bottlehead Quickie preamp in front and damn its just so organic and engaing.
  
 I have the HD800 also and the two are on very much on par but have different presentations I really enjoy both and wouldnt want to choose between them.


----------



## i luvmusic 2

davida said:


> john q lin said:
> 
> 
> > Your right. I have gone through a lot of headphones, I really enjoy the he500, maybe he6 could be my end game, and I like bass too maybe th900.
> ...


 
 I nearly sold mine.


----------



## vintinfinity

I have an Alps Blue Velvet 100k pot from an old project, is there anything I need to do to install it into the Crack amp, other than solder it in place of the stock unit?


----------



## Tom-s

Nope. "Solder and play".


----------



## vintinfinity

tom-s said:


> Nope. "Solder and play".


 
 cool, nice "free" upgrade I had around the house.


----------



## ClintonL

Anyone use both a crack + speedball and a woo audio wa7? Have the opportunity to get a wa7 but not sure if it'll be worth the upgrade.


----------



## vintinfinity

clintonl said:


> Just got my cetron 7236 linked a few pages ago. Loving it so far beats my raytheon 6080wb.




Just bought the last one from the eBay vendor that had these. What kind of changes did you notice from the 6080? Does this tube work without the speedball installed?

Edit: guess he had a few more


----------



## ClintonL

Speedballed and I think the highs sound a bit better and the bass is more controlled. Looking to upgrade my input tube now. I have an original mullard 12au7 atm. Anyone have any recommendations?


----------



## DavidA

clintonl said:


> Anyone use both a crack + speedball and a woo audio wa7? Have the opportunity to get a wa7 but not sure if it'll be worth the upgrade.


 
 I had a WA7d for a few months, BH Crack with good tubes much better for high z headphones like HD-650, HD-800, T1.  For lower z headphone I liked my Lyr2 better than the WA7d


----------



## Tom-s

Any e80cc. Can be used without any modifications when Speedball is installed. Even better with the e80cc/12bh7/5687 switches in place.


----------



## DavidA

clintonl said:


> Speedballed and I think the highs sound a bit better and the bass is more controlled. Looking to upgrade my input tube now. I have an original mullard 12au7 atm. Anyone have any recommendations?


 
 For input tube I like the Telefunken 12AU7 or new issue Electro Harmonix for the HD-650 and DT-990 premium 250ohm.


----------



## ClintonL

I've got a mod for 12bh7's. Not sure to grab one of them or a electro harmonix 12au7


----------



## Tom-s

Get whatever you find cheap.
 5687, 12bh7's and e80cc's are all worth it. 
 No experience with the EH12au7's. From the new production tubes my Genalex 12au7's Gold Lions best most of the premium NOS IME.
  
 Planning on putting a 120uf film cap for the last PS cap. Now using CLCLC (C1=C2=730uf).
 As you can see in the picture (with the tape in the position of the capacitor) it could be moved another centimeter away from the PS and chokes.
 So the cap would be mounted horizontally above the PS, between the chokes, front to back.
 Would this position induce hum?

  
 Edit: Change cap value


----------



## Idgit

I found the 12bh7 to be quite an upgrade. Put a 100uf as the last cap after installing one choke.


----------



## ClintonL

What 12bh7 would you reccomend?


----------



## Tom-s

I'm using "Healthkit" 12bh7's grey plate, taken from some sort of machine. Those were made by RCA and i found them for 3€ each.
 So IME the common RCA's sound great compared to 12au7's.


----------



## Maxhawk

When I was experimenting with the 12BH7 I was partial to the Sylvania 12BH7. However in my McIntosh MC240 I prefer the RCA 12BH7.


----------



## Tom-s

A side note with the 12BH7's. I use the long black and grey plate versions (Sylvania and RCA). And with all i prefer them with normal 6080's (Currently using a Mullard CV2984).
 With more bass heavy tubes like the Bendix 6080's and 6AS7G's (6H13C) there's too much emphasis on the bass for my preference.


----------



## vintinfinity

Just got my (used, built by a first timer and failed install pulled out to the side) basket case speedball boards installed and working. My pop is an old retired tech and he helped me trouble shoot it (he found a broken LED lead on one of the A and B boards, which we fixed) Then installed everything in the Crack amp.
  
 One wire was misplaced to the G instead of the O on the speedball board so I was disappointed it didn't work at first, but I had a beer, cooled off and dove back in and found it myself. Couple touches of the soldering iron and it's working great. 
  
 Feels good. I got a hell of a deal on it. Now I just need to get a 6sn7 adapter for the vintage RCA and Sylvania and GE tubes I have of that variety, a 12bh7 or two, and install my ALPS pot and maybe eventually some film cap upgrades, and possibly a choke if it's that big of a deal. Plus get some sanding paper and tung oil for the base. 
  
 Finally have my end game set up with the HD650s I'm using with it. 
  
 Cheers!


----------



## DavidA

vintinfinity said:


> Just got my (used, built by a first timer and failed install pulled out to the side) basket case speedball boards installed and working. My pop is an old retired tech and he helped me trouble shoot it (he found a broken LED lead on one of the A and B boards, which we fixed) Then installed everything in the Crack amp.
> 
> One wire was misplaced to the G instead of the O on the speedball board so I was disappointed it didn't work at first, but I had a beer, cooled off and dove back in and found it myself. Couple touches of the soldering iron and it's working great.
> 
> ...


 

 How about a picture after finished applied?


----------



## vintinfinity

davida said:


> How about a picture after finished applied?


 
 It's going to take me awhile. I'm out of expendable funds at the moment, so when I get to it, I will try to remember to get around to picture taking and posting.


----------



## deserat

Finished speedball upgrade last night. Voltage checks after small board install weren't right and it took me couple of days to figure it out. Turns out the stock 12au7 was bad. I dropped a Gold Lion in and everything checked out fine.  Speedball was well worth it. Am feeding the Crack with the Bifrost Multibit and it sings like an angel.
  
 Can't turn the volume past 10 o'clock or it's to loud which concern me as it use to sit at about 11 o'clock...  

 Am going to have to have a little shoot out between the Crack + HD600 and the Lyr2 + HE 560 later today but for now ... am just layin' back with a big old grin.


----------



## vintinfinity

Does anyone else prefer the stock Crack circuit to the speedball? I had a nice RCA black plate 12au7 in and the stock crack sounded really good to me. With the speedball the bass is better, deeper, more controlled and the attack is faster for everything else. But I kind of miss the lush reverb I was hearing more fully on vocals before I did the upgrade. We will see how it sounds with a 1957 RCA black plate 12bh7 in the speedball circuit soon though, I guess I will decide what to do at that point depending on how it sounds 

edit: I tried an rca clear top 12au7 and although it wasn't my favorite on the stock circuit (the 50s rca black plate was) it seems better than the black plate with the speedball. Weird how that works.





deserat said:


> Finished speedball upgrade last night. Voltage checks after small board install weren't right and it took me couple of days to figure it out. Turns out the stock 12au7 was bad. I dropped a Gold Lion in and everything checked out fine.  Speedball was well worth it. Am feeding the Crack with the Bifrost Multibit and it sings like an angel.
> 
> Can't turn the volume past 10 o'clock or it's to loud which concern me as it use to sit at about 11 o'clock...
> 
> ...




I think there is no need to worry about the volume control change after the speedball upgrade. I noticed that with mine as well.


----------



## DavidA

deserat said:


> Finished speedball upgrade last night. Voltage checks after small board install weren't right and it took me couple of days to figure it out. Turns out the stock 12au7 was bad. I dropped a Gold Lion in and everything checked out fine.  Speedball was well worth it. Am feeding the Crack with the Bifrost Multibit and it sings like an angel.
> 
> Can't turn the volume past 10 o'clock or it's to loud which concern me as it use to sit at about 11 o'clock...
> 
> Am going to have to have a little shoot out between the Crack + HD600 and the Lyr2 + HE 560 later today but for now ... am just layin' back with a big old grin.


 
 Did a comparison between my BH Crack + HD-650 vs Lyr2 + HE-560, both sound really good but it depends on the music to make me prefer one over the other.  Would like to hear what your thoughts are on your shoot out.


----------



## deserat

davida said:


> Did a comparison between my BH Crack + HD-650 vs Lyr2 + HE-560, both sound really good but it depends on the music to make me prefer one over the other.  Would like to hear what your thoughts are on your shoot out.


 
  
 So I've been listening the playlist i put together to make myself feel good about all the money I spend on headphone equipment for couple of hours and flipping between the various rigs.
  
 For anybody that's interesting the config is as such
  
 Spotify 320 ogg > USB > BiFrost Multibit 

 Then either 

 Lyr2 > Platnum graded Telefunken from UpscaleAudio
 Botthead Crackspeedball > TungSol 5998 + Gold Lion 12au7

 Notes on the Lyr2:
 I've long since settled on the HE 560 as my preferred headphone for this Amp.  I spent a bit of time with the HD600 plugged into it tonight because I also wanted to get a sense how the HD600 played in the Lyr2 vs the Crack. My  feeling is that the HD600 really isn't the best match for this amp. I also prefer the HE 560 on the Lyr2 to the HD800 ( which is a vastly superior headphone over all ).  The best way I  can describe this is to summon what is often referred to as the Sennheiser Veil.  That's is of course a feeling, your ears may totally disagree. 

 Notes on the Crack:
 I bought this thing for two reasons. 1) I've never heard a pure tube amp. 2) I could build it and that sounded fun.  I've had the Crack for about a month but just installed the speedball last night. When I plugged the HD600's into the Crack, sans speedball, I was so happy. I know this from my HDVA600, but the cure for the Sennheiser Veil is an amp designed specifically for high impedance headphones. Also I built the Crack and it's the first time I've soldered in 25 years while everything was is within spec, well... 25 years....
  
 Music: Lots of variety but all from a playlist I've put together to make myself feel good about spending so much money. https://open.spotify.com/user/deserat/playlist/5y92kYShyn1ekVZmmU2SL0
  
  
 Curve: Lyr2/HE 560  flatest. Lyr2/HD600  2, very flat  Crack/HD600  ( Crack turned the HD600 into a bass monster. Who knew. )

 Detail: The Lyr2 HE 560 . Lyr2/HD600, Crack HD600 ( it's pretty close with the HD  600 )
  
 Soundstage is more nuanced.  
     Crack/HD600 - Sound is closer to the head but it occupies a more holographic space than the other configurations. One can get a better sense of how the instrument is positioned in relation to the mic.
     Lyr2 / HE560 - Sound stage is widest of the three, but not as deep. By this I mean that all the instruments seem further away, but the distance from you ear doesn't vary as much. Instruments exist a liner continuum from left to right there is very little front to back. 
      Lyr2 / HD600 - This really splits the difference between the two above except that it sounds like somebody put a sheet between the instruments and the mic.
  
  
 I guess those are the things one is supposed to talk about, but they don't really tell you the difference between the two rigs. In truth I can't tell you I think one is better than the other, or that one is better than the other for certain genre's of music.  I really enjoyed everything I listened to on them both. There are however some very real differences. I think difference is probably best summed up as organic vs mineral.

 The Lyr2/HE 560 combo is very mineral, very crystaline, very sharp and to the point. It retrieves more detail and I can imagine that what I am hearing presented to me is very faithful to how it was transcribed. There is more control in the bass, the highs are tighter,  tremolo in stringed instruments is more apparent. 

 The Crack/HD600 combo well is organic, leaves blowing in the breeze..  Let's say that if the other combo presents exactly what was recorded, this combo presents what the artist heard while they recorded it. The presentation really just sounds more like you are in a small but sonically superior venue  listening to somebody make music. By that, I mean you don't hear the saliva on the singers lips as they separate but you do hear the impact the air waves have as her voice travels through it.

 Last note. I did plug the 560's in the Crack and there is more detail in the Crack than the HD600 is exposing. But getting the volume up to where I was listening caused distortion ( to be expected ) so they only stayed plugged in for few minutes at low volume. Am looking forward to hooking it up to the HD800.  

 EDIT: Spend the day with the Crack and and the HD800's. Also bounced back and forth between the HDVA600 and the Crack w/Speedball. Crack out classes the HD600, there is more exposed through the Amp than the headphones know what to do with. The crack vs the hdva left me feeling the above statements are even more true. I feel like the Crack was on par with the lyr2 detail wise, but not the hdva. The signature was not flat but presented more flat with the HD800 and was much tighter throughout the frequency spectrum than it was the HD600. The organic vs mineral was also more apparent, especially when it came to percussion instruments. Imagine, if you would, a drumstick striking a drum head... a well mic'd drum reveals things you'd never hear across the room... the hdva gives you the experience of the mic... the Crack gives you the experience of being in the room.


----------



## Walderstorn

deserat said:


> EDIT: Spend the day with the Crack and and the HD800's. Also bounced back and forth between the HDVA600 and the Crack w/Speedball.* Crack out classes the HD600*, there is more exposed through the Amp than the headphones know what to do with. The crack vs the hdva left me feeling the above statements are even more true. I feel like the Crack was on par with the lyr2 detail wise, but not the hdva. The signature was not flat but presented more flat with the HD800 and was much tighter throughout the frequency spectrum than it was the HD600. The organic vs mineral was also more apparent, especially when it came to percussion instruments. Imagine, if you would, a drumstick striking a drum head... a well mic'd drum reveals things you'd never hear across the room... the hdva gives you the experience of the mic... the Crack gives you the experience of being in the room.


 
  
 I kinda felt the same comparing my HD800 with my HD600, i like the HD800 also because it sounds less veiled in my ears and perceived "more" (quantity wise) of good sound that was perceived as better (sound wise).


----------



## vintinfinity

Just took out the Speedball from the Crack. Threw the stock resistors back in and while I was worried about the bass seeming to be less after the speedball, it sounds fine on W9 by Nicola Ratti, just a bit less controlled. I did gain back the sweet reverb and echo in regards to the vocals on songs like Hello - by Adele. For me, the speedball was so forward that it was a little too intense and was more fatiging than the stock circuit. 
  
 I was having a microphonics issue with a 12BH7 I put in there with the speedball, but I'm not sure if it was the circuit itself or the tube. The ebay seller thought the higher gain on the BH7 was causing it, but I'm not sure if that's true. Other people have reported using 12BH7 without microphonics. idk. Anyone have input on that? He was perhaps offering a replacement 12BH7 but seemed to back off that notion when he found out the stock tube is the 12au7.


----------



## JamieMcC

vintinfinity said:


> Just took out the Speedball from the Crack. Threw the stock resistors back in and while I was worried about the bass seeming to be less after the speedball, it sounds fine on W9 by Nicola Ratti, just a bit less controlled. I did gain back the sweet reverb and echo in regards to the vocals on songs like Hello - by Adele. For me, the speedball was so forward that it was a little too intense and was more fatiging than the stock circuit.
> 
> I was having a microphonics issue with a 12BH7 I put in there with the speedball, but I'm not sure if it was the circuit itself or the tube. The ebay seller thought the higher gain on the BH7 was causing it, but I'm not sure if that's true. Other people have reported using 12BH7 without microphonics. idk. Anyone have input on that? He was perhaps offering a replacement 12BH7 but seemed to back off that notion when he found out the stock tube is the 12au7.


 

 I believe the Speedball increases gain a bit as well if I remeber correctly I did have several 12au7 that were silent in use without the Speedball fitted but did noticed after I had fitted it a few of them now had a bit of noise.


----------



## vintinfinity

jamiemcc said:


> I believe the Speedball increases gain a bit as well if I remeber correctly I did have several 12au7 that were silent in use without the Speedball fitted but did noticed after I had fitted it a few of them now had a bit of noise.


 
 I had a couple 12au7 (out of about a dozen) that were microphonic with it too, but I'm not sure if the 12bh7 tube itself was undesirable in that regard or if the circuit was causing it on an otherwise good tube. (I spent a decent piece of change on it, so I want to know if it is within reason to exchange it for another one, not sure I can sell this one if it is microphonic in all circuits. [I don't know enough about problems with tubes to know if that makes sense)


----------



## cddc

doc b. said:


> Do put some kind of protection on the bell end, even if it's just paste wax or regular treament with a wipe of light oil like 3 in 1 or Remoil. It's raw steel that just gets a temporary coating of a sort of waxy oil in manufacturing, and it will eventually rust if left in even a moderately humid environment without any protection. Best bet is to clean it well to remove the existing treatment (naptha or acetone) and then shoot it with your choice of clear coat or paint.




Hi Doc, 

Do I need to clean and spray paint both sides of the bell end? I initially thought only the up side needs treatment.


----------



## Tom-s

It's over. It's done!
 After almost 12 months with my crack i'm finally done building it.
 Started out as a normal crack. Then speedball. Caught the modding bug, and the never-ending story begun. 
 It was a journey in search of the perfect sound, the cleanest soldering, the best cable routing and interference-less position for components.
 Thanks Bottlehead. I learned a lot from this project!
 In order of implementation:
 - Speedball
 - Stepped attenuator
 - Schottky diodes
 - Speedball 12bh7/e80cc mod
 - Dual choke in Power Supply
 - New housing for Crack On Steroids
 - Russian paper in oil output capacitors with new alloy frame inside
 - Russian teflon bypass for the output capacitors
 - Russian paper in oil last PS cap bypass
 - Power-amp: Direct wiring of RCA's to input tube (removal volume pot)
 - Speedball Maxhawk's switchboards for 12au7/e80cc/12bh7 and 5687 tubes
 - 730uf PS cap upgrade for cap 1 and 2
 - 120uf film cap for last PS capacitor and removal of PIO bypass.
 - Bottlehead Badge
 - Done .
 Pictures:


----------



## Keithpgdrb

Hmm. Bypassing to an external volume control. Never thought of that. I'll have to read more about your project.


----------



## Walderstorn

tom-s said:


> It's over. It's done!
> After almost 12 months with my crack i'm finally done building it.
> Started out as a normal crack. Then speedball. Caught the modding bug, and the never-ending story begun.
> It was a journey in search of the perfect sound, the cleanest soldering, the best cable routing and interference-less position for components.
> ...


 
  
  
 I cant even understand what you did on those pics lol wth dude eheh would like to hear it to compare to the regular crack w/speedball.


----------



## chuckwheat

tom-s said:


> It's over. It's done!
> After almost 12 months with my crack i'm finally done building it.
> Started out as a normal crack. Then speedball. Caught the modding bug, and the never-ending story begun.
> It was a journey in search of the perfect sound, the cleanest soldering, the best cable routing and interference-less position for components.
> ...


 
 wow


----------



## numberandlocation

vintinfinity said:


> Just took out the Speedball from the Crack. Threw the stock resistors back in and while I was worried about the bass seeming to be less after the speedball, it sounds fine on W9 by Nicola Ratti, just a bit less controlled. I did gain back the sweet reverb and echo in regards to the vocals on songs like Hello - by Adele. For me, the speedball was so forward that it was a little too intense and was more fatiging than the stock circuit.
> 
> I was having a microphonics issue with a 12BH7 I put in there with the speedball, but I'm not sure if it was the circuit itself or the tube. The ebay seller thought the higher gain on the BH7 was causing it, but I'm not sure if that's true. Other people have reported using 12BH7 without microphonics. idk. Anyone have input on that? He was perhaps offering a replacement 12BH7 but seemed to back off that notion when he found out the stock tube is the 12au7.


 
  
 How difficult is it to remove the Speedball upgrade? I just ordered the Crack+Speedball from the recent sale and wanted to be able to test it with and without the Speedball and be able to revert back to just the Crack if possible.


----------



## vintinfinity

numberandlocation said:


> How difficult is it to remove the Speedball upgrade? I just ordered the Crack+Speedball from the recent sale and wanted to be able to test it with and without the Speedball and be able to revert back to just the Crack if possible.




It's very easy to remove. You just desolder a few small wires and remove the boards, then reinstall two sets of resistors.


----------



## numberandlocation

vintinfinity said:


> It's very easy to remove. You just desolder a few small wires and remove the boards, then reinstall two sets of resistors.


 

 Would that be permanent then? Or could you choose to put it back in, for instance if I want to sell it at a later point.


----------



## chuckwheat

numberandlocation said:


> Would that be permanent then? Or could you choose to put it back in, for instance if I want to sell it at a later point.


 
 As long as you don't clip the wires, you could probably add and remove it in 15 minutes or so. (that is, after you've already assembled the speedball boards)


----------



## vintinfinity

Just got a Garage1217 6SN7 adapter in for my Crack amp. I've got a 60s (I think, it's got red lettering) staggered RCA black plate in there right now. Electronic stuff with vocals sounds good (great bass response and spaciousness), but for some reason, Adele's Hello and Say Hello (To Your New Lover) sound like a completely different microphone set up on her vocals, in a way I don't like as compared to my favorite 12au7 tubes. -edit:  after getting used to it, and going back to this material it sounds pretty good on the second time around.
  
 The Talking Heads - This Must Be The Place (Naive Melody0 2005 Remaster has a lot going on that stands out a bit more with the 6SN7. 
  
 Soon I will be able to try this thing with a NOS Tung Sol 5998 output tube that I snagged for less than half the going BIN rate on eBay. Not sure if it's a JAN tube, since I didn't get a clear shot of the base. Either way, supposed to sound good.


----------



## Aradea

Just got myself the Bendix 6080WB.. wow! Much better than my Tungsol 5998. Dont know why but the noise floor is much lower with the Bendix. I can hear everything much clearer and instrument separation improved by quite a lot.
It needs more dial on the knob to a achieve the same level of volume compared to the Tungsol..
Could be the end game power tube hehe


----------



## Paladin79

I am at work and we have restrictions on searching some sites so I was curious if the Bottlehead Crack is still being sold in kit form and what the approximate price was at this time?
  
 I have plenty of experience in electronics and soldering so the assembly would not be an issue for me and I am apt to make some of the modifications listed here.
  
 If that amp has been replaced, is there a current model I should look for?
  
 thanks


----------



## DavidA

paladin79 said:


> I am at work and we have restrictions on searching some sites so I was curious if the Bottlehead Crack is still being sold in kit form and what the approximate price was at this time?
> 
> I have plenty of experience in electronics and soldering so the assembly would not be an issue for me and I am apt to make some of the modifications listed here.
> 
> ...


 
 Still available in kit form, currently on sale for $249 + shipping, and its in stock, $364 with speedball option.


----------



## Paladin79

davida said:


> Still available in kit form, currently on sale for $249 + shipping, and its in stock, $364 with speedball option.


 
 Thanks David, I meant to look it up when I got home last night and forgot. I do have a complete electronics shop at home and still have some precision resistors and such  I could swap into one of the units. I also have some top quality wire that I could use for some of the hook ups so it should be a fun project for me. There is a wealth of info in this thread and I look forward to reading some of it as I build one of the amps.


----------



## DavidA

paladin79 said:


> Thanks David, I meant to look it up when I got home last night and forgot. I do have a complete electronics shop at home and still have some precision resistors and such  I could swap into one of the units. I also have some top quality wire that I could use for some of the hook ups so it should be a fun project for me. There is a wealth of info in this thread and I look forward to reading some of it as I build one of the amps.


 
 It was a great project for my GF and I, started at 4pm and finished at 9am, enjoyed 4 bottles of wine and some great pupu's (local word for horderves) during the build.


----------



## Paladin79

davida said:


> It was a great project for my GF and I, started at 4pm and finished at 9am, enjoyed 4 bottles of wine and some great pupu's (local word for horderves) during the build.


 
 very cool. Did you do the Speedball option? I am likely to build it quickly and then go back and upgrade portions of it as time allows. It looks like it has great accessibility and lends itself to upgrades.


----------



## DavidA

paladin79 said:


> very cool. Did you do the Speedball option? I am likely to build it quickly and then go back and upgrade portions of it as time allows. It looks like it has great accessibility and lends itself to upgrades.


 
 Built it first without the speedball, used it for a few months and then installed the speedball but to me its better without it so took it out.


----------



## Paladin79

davida said:


> Built it first without the speedball, used it for a few months and then installed the speedball but to me its better without it so took it out.


 
 Ok I will probably build it without and add it later on as I read more.


----------



## notphilip

Hi all,
 I just finished my first BHC build, but it looks like I have some weird resistances popping up. 
  
 Any ideas on what to check for first? 
 Here are some pics: http://imgur.com/a/tpOml

 Below are my measurements:
 Terminal    Target            Measure
 1               *                    Starts at 20Mohm and slowly decreases
 2               *                    Starts at 20Mohm and slowly decreases
 3               0                    0
 4               *                    Starts at 10MOhm and slowly decreases
 5               *                    Starts at 8MOhm and slowly decreases
 6               2.4KOhm    2.49KOhm
*7               2.9KOhm    37MOhm and slowly climbs 
 8               0                    35MOhm and slowly decreases
 9               2.9KOhm    37MOhm and slowly climbs *
 10               2.4KOhm    2.49 Kohm
 12               0                    0
*13               * climb towards 270KOhm    6MOhm and decreasing*
 14               0                    0
 20               0                    0
 22               0                    0
*B3               2.9KOhm    35MOhm 
 B6               2.9KOhm    35MOhm*
 RCA ground red    0            0
 RCA center pin red    90-100KOhm    110.1KOhm
*RCA center pin black    90-100KOhm    38MOhm*
 RCA ground black    0    0


----------



## Paladin79

notphilip said:


> Hi all,
> I just finished my first BHC build, but it looks like I have some weird resistances popping up.
> 
> Any ideas on what to check for first?
> ...


 
 If resistors were the only things in the circuit or by themselves you might indeed wonder what is up. You are also dealing with inductors and capacitors in series and parallel circuits. An ohmmeter induces a small amount of volage and current into a circuit and what you were reading is the reactance of said circuits.


----------



## mordicai

You'll have more luck with this if you go on the Bottlehead.com site and post in the forums under Crack


----------



## notphilip

It turned out to be a bad solder joint at terminal 13. 
 Once I fixed that, everything else downstream measured correctly. 
Voltage checks went well too and it finally works! It sounds awesome


----------



## deserat

Took my Crack home to do some work on it. Now all I have at work is this amazingly resolving, highly dynamic, accurate imaging,  much more expensive HDVA 600. I miss my Crack. I think I like it more.


----------



## HiGHFLYiN9

Glad you're following your own ears. Sometimes the best performing (on paper), most detailed amp isn't what sounds the most enjoyable.


----------



## gwitzel

Hello,
  
 I have recently build my first headphone amp, the Bottlehead crack. I tremedously enjoyed it, everything worked right away, all parts were there, and it sounds fantastic.
  
 I inlcuded a step attenuator from the beginning, and later the Speedball upgrade. Then I added some film caps, the choke, and the Cree diodes. I am using an input tube from Tube Amp Doctor (12AU7WA / E82CC TAD Premium Selected). This together with the stock power tube sounds incredibly nice. I tried an inexpensive Chinese tube (6AS7G / 6N5P Shuguang, see picture below), but that didn't sound good. So I wanted to see what all the fuss is about the Tung Sol 5998, despite the high price.
  
 Yesterday, the tube was delivered from a seller with spottless reputation, and I had some time to listen to it before leaving for a trip. It is indeed more detailed and stages better, right in the first minutes of use. But I realized that if you carefully tap the tube with the fingernail you hear some 'tink' sound. The tube seems to be perfectly quite while playing music.
  
 My questions are: Is this a microphonic tube? Would you be ok with using this one if it does not make noises while playing music. I found very different opinions about if this is a problem with microphony or inavoidable. Also, some people expect microphony from the input tubes, but not from output tubes. Some say, tapping a hot tube with the fingernail might even harm the tube.
  
 I would appreciate some advice. I am very new to DIY tube gear, and I have payed almost $200 for this tube and want to make sure that it is a solid investment.
  
 Thank you!


----------



## vintinfinity

gwitzel said:


> Hello,
> 
> I have recently build my first headphone amp, the Bottlehead crack. I tremedously enjoyed it, everything worked right away, all parts were there, and it sounds fantastic.
> 
> ...


 
 My amp is microphonic to some extent with many of the tubes I've tried for input and output.  My 5998 is a bit microphonic like that too. It's fine for listening. I only paid $60 for mine though.


----------



## Maxhawk

I wouldn't worry about the microphonics unless you're in an environment where the amp gets bumped often and you can hear it.
  
 As far as the sound goes, the 5998 sound signature is very subjective. It's got a lower output impedance so bass typically is tighter and better controlled. I also think it sounds more analytical than other tubes and results in a more detail. It also means it sounds more like solid state than other tubes which some people like and other don't. I've worked with solid state most of my life so I can appreciate what the 5998 brings to the table, but it also distances you from what most like about tubes. I've grown to like the warm signature and musicality of tubes and these days my favorite output tube is the Bendix 6080WB slotted graphite. A close second are the Sylvania Gold Brand GB6080 and Cetron 7236. These tubes all offer a warmer sound with a fat sounding bass, which I think pairs well with the HD800 which are known to be quite analytical and a little thin in the bass.


----------



## gwitzel

vintinfinity said:


> My amp is microphonic to some extent with many of the tubes I've tried for input and output.  My 5998 is a bit microphonic like that too. It's fine for listening. I only paid $60 for mine though.


 
  
  


maxhawk said:


> I wouldn't worry about the microphonics unless you're in an environment where the amp gets bumped often and you can hear it.
> 
> As far as the sound goes, the 5998 sound signature is very subjective. It's got a lower output impedance so bass typically is tighter and better controlled. I also think it sounds more analytical than other tubes and results in a more detail. It also means it sounds more like solid state than other tubes which some people like and other don't. I've worked with solid state most of my life so I can appreciate what the 5998 brings to the table, but it also distances you from what most like about tubes. I've grown to like the warm signature and musicality of tubes and these days my favorite output tube is the Bendix 6080WB slotted graphite. A close second are the Sylvania Gold Brand GB6080 and Cetron 7236. These tubes all offer a warmer sound with a fat sounding bass, which I think pairs well with the HD800 which are known to be quite analytical and a little thin in the bass.


 
  
 Thank you for the reply, this is reassuring. The seller also confirmed that light microphonics are normal and might become better with time. However, it is very light indeed so I will not worry.
  
 I felt that the stock tube had a nice timbre and was really pretty good. I am curious to see how I like the TS 5998. Unfortunately, I did not really have time to listen to it carfully. I will know more in 3 weeks when I am back home. After my last mod I had the sense of incredible channel speparation and clarity, but in loud orchestra moments it sounded a bit direct and dense, and the channel separation sounded a bit artificial. I hoped for a bit more transparancy in those dense moments, and more spacial coherence.
  
 However, already with the stock tube the presentation was so real. My chain is:
  
 Mac/Audirvana -> Schiit Wyrd -> Singxer F1 -> Schiit Gungnir MB BNC-input -> Bottlehead Crack -> HD600/650.
  
 I love that I could build this myself for this price. The American audio community is awesome (says the German)


----------



## Doc B.

Tapping a hot tube with your fingernail might damage your fingernail, but unless your fingernail is a like a sledge hammer it's not going to harm a tube like the 5998. A 6080WA was designed for twenty 450G hits ferchrissakes.


----------



## gwitzel

doc b. said:


> Tapping a hot tube with your fingernail might damage your fingernail, but unless your fingernail is a like a sledge hammer it's not going to harm a tube like the 5998. A 6080WA was designed for twenty 450G hits ferchrissakes.


 
  
 Haha, I thought so... twenty 450G hit? So I still have 18 to go? 
  
 The web is full of strange opinions, sometimes very tough to sort out when you deal with technology that is new to you.
  
 However, the Crack is a great set and I had incredibly much fun building it! Thank you!


----------



## networkn

I have a quick dumb question. I just added my speedball to my crack, and am about to power on for the first time. Instructions mention volume to lowest point, but the issue I have and have always had without turning it on, is how do I tell what is lowest? I didn't (stupid) mark this in prior occasions for some reason, but will do so now. 
  
 How do others mark it as such? is there a "nice" way that looks good?


----------



## Tom-s

I don't have it marked. It's just the point where the volume pot is all the way to the left and stops.* Don't know how to describe this. 
 Don't plug anything in but the powercord.
 And never turn it on with a headphone connected. I leave it on for +-30 sec - 1 min before plugging in my headphones.
  
 Should mention i removed my volume pot altogether and use a pre-amp, so my crack powers on at maximum volume every time without any problems.


----------



## networkn

tom-s said:


> I don't have it marked. It's just the point where the volume pot is all the way to the left and stops.* Don't know how to describe this.
> Don't plug anything in but the powercord.
> And never turn it on with a headphone connected. I leave it on for +-30 sec - 1 min before plugging in my headphones.
> 
> Should mention i removed my volume pot altogether and use a pre-amp, so my crack powers on at maximum volume every time without any problems.


 
  
 Hi. 

 Thanks for the reply. Left viewing from which side?


----------



## Tom-s

Anticlockwise


----------



## networkn

tom-s said:


> Anticlockwise


 
  
 Are you saying, if the RCA's are top left, and the volume knob is bottom left (headphone jack bottom right), then turning the knob all the way anticlockwise, will be at it's quietest (IE 0) and all the way clockwise would be say 10?


----------



## Keithpgdrb

networkn said:


> Are you saying, if the RCA's are top left, and the volume knob is bottom left (headphone jack bottom right), then turning the knob all the way anticlockwise, will be at it's quietest (IE 0) and all the way clockwise would be say 10?


Yes. Works like every other volume in the world.


----------



## networkn

keithpgdrb said:


> Yes. Works like every other volume in the world.


 
  
 THANK YOU for taking the opportunity to make me feel extra stupid by using SARCASM! It's a fantastic way for me to start my week!


----------



## networkn

So I installed my speedball upgrade over the weekend, voltages all matched except :
  
19 - Reads 80v (Should be 0)
 20 - 0 (Should be 206)
  
Apparently my version of the manual doesn't reflect an error which says measurement of 19 isn't relevant (no need to test) and 20 is supposed to be zero. (0v)


----------



## JamieMcC

networkn said:


> So I installed my speedball upgrade over the weekend, voltages all matched except :
> 
> 19 - Reads 80v (Should be 0)
> 20 - 0 (Should be 206)
> ...


 
  
 In the Crack section on the BHF there is a sticky on Crack manual corrections
  
 http://bottlehead.com/smf/index.php?topic=657.0


----------



## networkn

Would anyone who has installed their speedball upgrade say that sound was more sibilent afterward?


----------



## deserat

networkn said:


> Would anyone who has installed their speedball upgrade say that sound was more sibilent afterward?


 
  
 Didn't notice more sibilence but my 12au7 was bad so I upgrade that at the same time.


----------



## networkn

Hi. 
  
 Did anyone do this mod: 
  
 http://bottlehead.com/smf/index.php?topic=2946.0
  
 Who would mind photographing it, as I can't really understand exactly what is required. 
  
 Also sorry I haven't read through the 523 pages of this thread, but is there a consensus on what valves to buy as a must-do upgrade. I am not particularly budget sensitive but also don't want to spend stupid money either. I guess max $100?
  
 It would need to be plug and play though, I am done soldering my unit for a while.


----------



## Bacci

networkn said:


> Hi.
> 
> Did anyone do this mod:
> 
> ...


 

 It's not really an upgrade mod, just a precaution to avoid DC offset on your headphones in some situations, like when you plug them in right after turning the amp on. 
 Solder the three pins on the outside of the headphone jack (facing away from the 12AU7, the side where there are 2 unused pins), together.


----------



## audiojun

Does anyone have an 5998 tube for sale? I am mainly interested in a tube that will lower the output impedance of my crackatwoa.


----------



## gab840

Bottlehead sale is going on guys.. Grab what you want.


----------



## lenroot77

Anyone looking for an unassembled kit, pm me!


----------



## buke9

lenroot77 said:


> Anyone looking for an unassembled kit, pm me!


If you would have posted it a day earlier I would have bought it . Bought a already done one really wanted put it together myself.


----------



## NightPhotograph

audiojun said:


> Does anyone have an 5998 tube for sale? I am mainly interested in a tube that will lower the output impedance of my crackatwoa.


 
 Have you ever listened to Crack itself? If yes, How do you compare it to Crack a-two-a? I own HD 800 and cannot choose between Crack and Crack a-two-a.


----------



## audiojun

I built the crack sold it and built T3 then bought a crackatwoa.

The crackatwoa sounds just like the crack, but it is a much lower in noise with the tube shunt regulator and with a better power transformer. Like the crrack it gots a good midrange harmonics easy to listen to, but the treble is a veiled and the bass is too bloomy (in comparison to T3). Although I can change the sound with modifications, but I found it sounded that way with all the tubes I had. I have a 7802 tube coming, higher transconductance than a 5998, 3 times higher than 6080, it should lower the output impedance from 120 to 42 ohms with the 7802 tube which would probably make the crack sound much better.

Currently I am trying to get the Crackatwoa to sound like my Torpedo III while preserving that midrange musicality, while I am trying to get the Torpedo III to have a rich musical tone like the crack.

If it was my money I would modify the HD800 (super dupont resonator with absorber) and get a Torpedo III it is much more linear, powerful dynamics, fast transients, tight bass, crisp treble. The crackatwoa though still has the musical midrange which I prefer over the Torpedo III. Although I heard the T3 isn't available no more as a kit. I haven't fully modded my crackatwoa yet so my impressions may change. Though if never heard the T3 I would be very happy with the crackatwoa.


----------



## NightPhotograph

audiojun said:


> I built the crack sold it and built T3 then bought a crackatwoa.
> 
> The crackatwoa sounds just like the crack, but it is a much lower in noise with the tube shunt regulator and with a better power transformer. Like the crrack it gots a good midrange harmonics easy to listen to, but the treble is a veiled and the bass is too bloomy (in comparison to T3). Although I can change the sound with modifications, but I found it sounded that way with all the tubes I had. I have a 7802 tube coming, higher transconductance than a 5998, 3 times higher than 6080, it should lower the output impedance from 120 to 42 ohms with the 7802 tube which would probably make the crack sound much better.
> 
> ...


 

 Thanks for sharing your opinion on Crackatwoa. I was worried that Crackatwoa would loose that warmness of Crack that HD 800 really needs for the sake of a blacker background. Now, I think I will go for it. I believe T3 is quite bright which might not be a good match for the HD 800 though very resolving.


----------



## audiojun

nightphotograph said:


> Thanks for sharing your opinion on Crackatwoa. I was worried that Crackatwoa would loose that warmness of Crack that HD 800 really needs for the sake of a blacker background. Now, I think I will go for it. I believe T3 is quite bright which might not be a good match for the HD 800 though very resolving.


 
  
 Crackatwoa is a good choice actually, for people who care about mids and musicality. Torpedo III will beat you up with the dynamics it throws at you. When matched with the HD 800 it's playing to the strengths of the HD 800, showing off it's dynamics and transient response just something that needs to be experienced imo. Probably need to be paired with a modded HD 800 because of brightness like you said.
  
 My Crackatwoa sounds amazing right now, rolled a 7802 Tung-Sol and wow it's flexing it's muscles, it's probably getting closer to the T3 in dynamics. Tighter bass, more crisp treble, beautiful mids, sound stage is big, vocals are beautiful and come to life. Also I have an output impedance about ~42 ohm thanks to that 7802 tube. Still need to replace the stock output capacitors, should be able to get the parts by next week. Also no twoquiet stepped atteunator yet.


----------



## Doc B.

I suspect your output impedance is not quite that low. The current in the Crack circuit is low enough that CF output impedance calculations using the published tube data tend to be too optimistic. My SWAG would be it's probably more like 70-80 ohms. That's still a nice improvement from a 6080 and certainly should be audible, especially on lower impedance cans.
  
 You have the dubious honor of now having contributed to driving the price of 7802s into the stratosphere like the 421A and 5998. Welcome to the club, I've done that with 5998s, 6DN7s, NOS mesh plate tubes, reel to reel tape decks, prerecorded tapes, and a few other things over the years. Unfortunately I have never been smart enough to stockpile the item I have been enthused about before announcing my enthusiasm.


----------



## audiojun

Yeah probably not that low, but it does have triple the transconductance of 6080.

My 7802 was cheaper than an 5998. Probably would be good to stock pile a few 7802 since I could see these are going to be very expensive in the future since I could only find one seller with it in stock.

Doc I am wondering if it's possible to drop the impedance even more? I know its possible to lower the impedance by lowering the cathode resistor value, but crack is CCS loaded so I am not sure what to do on the CCS.


----------



## NightPhotograph

audiojun said:


> Crackatwoa is a good choice actually, for people who care about mids and musicality. Torpedo III will beat you up with the dynamics it throws at you. When matched with the HD 800 it's playing to the strengths of the HD 800, showing off it's dynamics and transient response just something that needs to be experienced imo. Probably need to be paired with a modded HD 800 because of brightness like you said.
> 
> My Crackatwoa sounds amazing right now, rolled a 7802 Tung-Sol and wow it's flexing it's muscles, it's probably getting closer to the T3 in dynamics. Tighter bass, more crisp treble, beautiful mids, sound stage is big, vocals are beautiful and come to life. Also I have an output impedance about ~42 ohm thanks to that 7802 tube. Still need to replace the stock output capacitors, should be able to get the parts by next week. Also no twoquiet stepped atteunator yet.


 
 Eventually, I decided to get Crackatwoa for my HD 800. Doc says this kit is not recommended for inexperienced builders and they are better off with Crack. Since Crackatwoa would be my first DIY project, I'd like to know whether it's just going to take more time to build or its soldering needs better techniques. 
  
 Cheers


----------



## Doc B.

It just takes more time to build than a Crack, and some PC board soldering. So it's sort of like a Crack with Speedball, but with more parts. I've seen guys who never picked up a soldering iron build stunning amps, and guys who brag about being experienced technicians completely screw them up. A successful build is much more about exercising patience and following instructions than having any particular skill or level of experience.


----------



## sureshot1234

Would the Bottlehead Crack 1.1 OTL work ok with my Sennheiser HD598SE and AKG K612 Pro headphones?


----------



## jamesino

I currently have an HD 650 with Magni/Modi 1 and am looking to purchase a used, pre-built BH Crack + non-installed Speedball.
  
 I have zero soldering experience and no tools.
  
 If upon audition I find that the BH Crack works, how likely is it to break several months down the road?
  
 Is there anywhere in NYC where I can bring the BH Crack and ask someone to install the Speedball upgrade for me? Any idea how much this typically takes and how much it would cost?


----------



## deserat

sureshot1234 said:


> Would the Bottlehead Crack 1.1 OTL work ok with my Sennheiser HD598SE and AKG K612 Pro headphones?


 
  
 That's an interesting question. Interesting enough that I actually found and pulled out my 598's and plugged them into the Crack for the first time since I used them to test that the crack worked. I also pulled the HD600's out just to make sure I wasn't being  partial to the HD800. Even listened with both the 6080 that came stock and 5998 that I've upgraded to.  I can't speak to the AKG's sorry. 

 The HD598 with  both the stock and a Tung Sol 5998 sound.... well... not great.  I enjoyed the treble  but the bass distorted and dominated the mids.  Not the kind of distortion that makes you want to rip the headphones off in fear that they might get damaged but that kind of annoying distortion you hear when the band you wanted to see brought a set of speakers that are to big  for the  venue they are playing in. It reminded me of seeing a punk band in tiny bar.  I can't recommend it unless you are underage, really drunk, and looking for a fight.

 The AKG's will probably fair better as they are at the bottom end of the Crack's recommended impedance, 120 ohm. Which is roughly double the 598's 50.


----------



## vintinfinity

jamesino said:


> I currently have an HD 650 with Magni/Modi 1 and am looking to purchase a used, pre-built BH Crack + non-installed Speedball.
> 
> I have zero soldering experience and no tools.
> 
> ...




If it works and everything (impedance and voltage checks) is in order, it is pretty unlikely to suddenly go bad. New ish caps and resistors last quite awhile (many years, decades even). Tubes do get used up but that can take years and years as well. 

If you can find an electronic repair specialist or a local hobbyist that is willing to install the speedball, it is pretty simple and doesn't take long. Also easy to remove and put things back the way they were if you don't like it. No idea on cost, but it shouldn't be too bad since it is so simple.


----------



## sureshot1234

deserat said:


> That's an interesting question. Interesting enough that I actually found and pulled out my 598's and plugged them into the Crack for the first time since I used them to test that the crack worked. I also pulled the HD600's out just to make sure I wasn't being  partial to the HD800. Even listened with both the 6080 that came stock and 5998 that I've upgraded to.  I can't speak to the AKG's sorry.
> 
> Thank you for that information might just get a hybrid for now get a taste for tube sound to make sure I like it then when I get hd600-700 or beyer770 880 990 250 ohm I will look at the crack again
> 
> ...


----------



## deserat

@sureshot1234  was there suppposed to be a reply attached to that quoted post or have I finally become simply quotable?  
  
 Edit:
  
 Sorry I didn't see the paragraph added in the middle of the quote.  I can fully attest to the quality of the HD600 with the Crack. Best I've ever heard them sound.
  
 The 598 are what ruined my life though. I bought them and with the Aune T1. They showed me what music could be like... and well the rest is money flying out the door. The 598 sound pretty good with a hybrid. I've used 'em with a couple and the results were nice.


----------



## sureshot1234

deserat said:


> @sureshot1234
> was there suppposed to be a reply attached to that quoted post or have I finally become simply quotable?
> 
> Edit:
> ...




Yes it was supposed too lol thank you for the Info I will probably just wait for that amp when I have higher impedance headphones that match well with it


----------



## adydula

598 are 50 ohms
 akg 612 are 120 ohms
  
 and
  
Crack is an output transformerless amp designed specifically for running higher impedance (200 ohms or higher) headphones like the many Sennheiser, AKG and Beyer designs.
  
So not that good.....
  
Alex


----------



## buke9

audiojun said:


> Yeah probably not that low, but it does have triple the transconductance of 6080.
> 
> My 7802 was cheaper than an 5998. Probably would be good to stock pile a few 7802 since I could see these are going to be very expensive in the future since I could only find one seller with it in stock.
> 
> Doc I am wondering if it's possible to drop the impedance even more? I know its possible to lower the impedance by lowering the cathode resistor value, but crack is CCS loaded so I am not sure what to do on the CCS.


Do you mind telling where you sourced the 7802 ? After your post about it I looked high and low and couldn't find one. I just think it might help out my HD 700's just a bit more than the 5998 I have right now. The RCA 6080 sounded bad bloaty bass and everything else for that matter. Screwed up and was looking for a Chatham 5998 and bought a pair of Chatham 6080's (late night eBay and beer) and sounded a lot better but so far the TS-5998 sounds better. The 7802 just might be a little better I hope.


----------



## jamesino

Thanks for the help. I just purchased a used, pre-built BH Crack.
  
 Just one question, do I need to plug the Crack directly into my home AC outlet, or can I plug it into a powerstrip shared with other equipment? I live in the USA and have standard US outlets.


----------



## buke9

jamesino said:


> Thanks for the help. I just purchased a used, pre-built BH Crack.
> 
> Just one question, do I need to plug the Crack directly into my home AC outlet, or can I plug it into a powerstrip shared with other equipment? I live in the USA and have standard US outlets.


A power strip is fine. Unless you get a lot of noise then something might have a ground loop problem.


----------



## jamesino

It should be safe to leave my HD 650 plugged into the BH Crack when powering on and off the Crack right?
  
 All I have to do is turn the volume all the way down, and then power on/off right?


----------



## Doc B.

Yes. The startup voltage with the headphones plugged in is very low. For belt-and-suspenders type assurance you can do the following, if it hasn't already been done -
  
http://bottlehead.com/smf/index.php?topic=2946.0


----------



## jamesino

Are your guys' BH Cracks dead silent 100% of the time when music is not playing?
  
 I hear occasional crackles/static in my left ear only. The crackle/static persists even when volume is 0 and/or DAC not plugged into USB port. The loudness of the crackle/static is unaffected by the volume knob. Unplugging the left RCA cable appears to stop the crackle/static. 
  
 I tried carefully lifting it up and poking at the wires with a chopstick, but can't reproduce the static.
  
 I also tried plugging the BH Crack directly into wall AC outlet, instead of powerstrip, and the crackle/static still persists. I also tried clearing the surrounding area of any electronics, the crackle/static still persists. It occurs from the moment I turn the amp on, and even after it's been playing for 30-45 mins. 
  
 It occurs every 5-20 secs for a split second. 
  
 Not terribly bothersome, but it'd be great if there was an obvious solution I'm missing.


----------



## buke9

jamesino said:


> Are your guys' BH Cracks dead silent 100% of the time when music is not playing?
> 
> I hear occasional crackles/static in my left ear only. The crackle/static persists even when volume is 0 and/or DAC not plugged into USB port. The loudness of the crackle/static is unaffected by the volume knob. Unplugging the left RCA cable appears to stop the crackle/static.
> 
> ...


Not being a expert by any means but if you unplugged the source and it stopped it could be the source that is the problem not the amp. Not a real safe thing to do poking around with the amp on. Easy to budge a wire loose if not connected well and if it was a wooden chopstick wood is not a great conductor but still is one.


----------



## Doc B.

If the noise is occurring at intervals it is possibly due to outside interference from some appliance, cellphone or wifi router. From your description that the noise is there even with the DAC not connected it is apparent that the noise is not coming thru the cables from the DAC. For technical support regarding Bottlehead gear I always recommend posting your inquiry on the Bottlehead forum, as there is a pretty rich experience base.
  
 You might try different tubes to eliminate the possibility that one of them is sensitive to interference.


----------



## jamesino

Thanks guys, I'll do some more testing. So to be sure, it is NOT safe to poke around the amp while it is turned on? I got that idea from reading some suggestions on the BH forums where someone recommended doing some poking with a chopstick to see if the crackle can be emulated to help isolate the possible weak solder joint.


----------



## buke9

doc b. said:


> If the noise is occurring at intervals it is possibly due to outside interference from some appliance, cellphone or wifi router. From your description that the noise is there even with the DAC not connected it is apparent that the noise is not coming thru the cables from the DAC. For technical support regarding Bottlehead gear I always recommend posting your inquiry on the Bottlehead forum, as there is a pretty rich experience base.
> 
> You might try different tubes to eliminate the possibility that one of them is sensitive to interference.


They didn't say when the DAC was disconnected just turned off and stopped when they pulled the left RCA out of the amp.


----------



## Doc B.

He did however say the DAC was disconnected from the USB port. And that the noise persisted with the volume set to 0. So it's fairly safe to assume that it was not coming thru signal hot. That would imply noise pickup is likely to be coming in on the left channel ground somewhere, possibly at the RCA jack or the cable shield, or being picked up by a tube.


----------



## luiscasgt

Hi guys,
 It has been a while since my last visit to this forum. I have had my bottlehead crack for about three years now and recently I started noticing a crackling coming out, even with the source off and regardless of the headphones it is connected to, tried it with Beyerdynamic DT880(600ohm) and Sennheiser HD-650 (more noticeable on this ones).
  
 Do you guys think I need to replace tubes on it, I usually use it Mon-Fri for about 7-8hrs. I only had a spare 12AU7 and replaced it but same thing. Your thoughts are greatly appreciated.


----------



## deserat

luiscasgt said:


> Hi guys,
> It has been a while since my last visit to this forum. I have had my bottlehead crack for about three years now and recently I started noticing a crackling coming out, even with the source off and regardless of the headphones it is connected to, tried it with Beyerdynamic DT880(600ohm) and Sennheiser HD-650 (more noticeable on this ones).
> 
> Do you guys think I need to replace tubes on it, I usually use it Mon-Fri for about 7-8hrs. I only had a spare 12AU7 and replaced it but same thing. Your thoughts are greatly appreciated.


 
  
 I had a bad 12AU7 that was crackling. Replaced it and it went away. 6080's can be had for pretty cheap so it's worth a try. Could be any number of things, though personally I'd start with tubes. Time doth take it's toll.


----------



## Allanmarcus

I thought I would share some anti-vibration stuff I'm using. It's cheap and effective.
  
 First, the pads. I got them here:
  
 http://www.supplyhouse.com/DiversiTech-MP-2E-EVA-Anti-Vibration-Pad-2-x-2-x-7-8
 http://www.supplyhouse.com/DiversiTech-MP-2C-Rubber-Cork-Anti-Vibration-Pad-2-x-2-x-7-8
  
 They sell 3x3 and 4x4 too.
  
 Pricing is very cheap, but shipping can be tough, so buy dozens. You will use them all over the place. I love them under speakers to both reduce vibrations and to protect surfaces.
  
 The wood board under the crack is just for testing, which I just started. So far the isolation is great, so I will make that board pretty.
  
 I found that even light vibrations transmit through the crack, so anti-vibration was needed. AV stuff in the audiophile world can be ridiculously expensive. Perfect opportunity for DIY.
  
 Next I might try some tube damper, specifically some inexpensive o-rings, and see what that does.


----------



## jamesino

doc b. said:


> He did however say the DAC was disconnected from the USB port. And that the noise persisted with the volume set to 0. So it's fairly safe to assume that it was not coming thru signal hot. That would imply noise pickup is likely to be coming in on the left channel ground somewhere, possibly at the RCA jack or the cable shield, or being picked up by a tube.


 
 Did some more testing and turns out the crackles were coming from my laptop's Wifi and my phone. 
  
 The phone is of course easy to move away, but I can't move my laptop more than 12 inches away due to space limitations. I thought this would be far away enough to not cause interference, but I guess that's not the case.  
  
 So I just save my Spotify playlists offline and listen while with the wifi turned off.
  
 Thanks for the help guys!


----------



## deserat

jamesino said:


> Did some more testing and turns out the crackles were coming from my laptop's Wifi and my phone.
> 
> The phone is of course easy to move away, but I can't move my laptop more than 12 inches away due to space limitations. I thought this would be far away enough to not cause interference, but I guess that's not the case.
> 
> ...


 
  
 I had that problem! Those tubes definately act as wifi antenna. Setting my laptop  on a different elevation than the Crack got rid of it.


----------



## donato

I just installed my Speedball this morning.  Can't really speak to the changes necessarily since I didn't listen too much before the upgrade and also changed the tubes to Mullard 12AU7 and Bendix 6080WB from stock and use this to drive my HD650.  It's a very fun and enjoyable setup with the additional satisfaction of it being DIY.
  
 Question for everyone - I have a pretty decent collection of 6SN7, VT-99, VT-231, 6F8G from my main rig (Woo WA22) and ordered some 6SN7 to 12AU7 and 6F8G to 12AU7 (I was sure to get the 6.3V versions) so I can take advantage of my existing tubes instead of investing in 12AU7 and such.  Is there any "consensus" on if either type of driver tube is any better or worse with the Crack?


----------



## chuckwheat

Alrighty. The time has come to replace the stock tubes. What's everyone's favorites? . I'm using the hd650, and listen to some of everything. Thanks fellas


----------



## JamieMcC

donato said:


> I just installed my Speedball this morning.  Can't really speak to the changes necessarily since I didn't listen too much before the upgrade and also changed the tubes to Mullard 12AU7 and Bendix 6080WB from stock and use this to drive my HD650.  It's a very fun and enjoyable setup with the additional satisfaction of it being DIY.
> 
> Question for everyone - I have a pretty decent collection of 6SN7, VT-99, VT-231, 6F8G from my main rig (Woo WA22) and ordered some 6SN7 to 12AU7 and 6F8G to 12AU7 (I was sure to get the 6.3V versions) so I can take advantage of my existing tubes instead of investing in 12AU7 and such.  Is there any "consensus" on if either type of driver tube is any better or worse with the Crack?


 

 I was fond of running 6sn7 in the driver slot but never got round to trying the 6F8G


----------



## JamieMcC

chuckwheat said:


> Alrighty. The time has come to replace the stock tubes. What's everyone's favorites? . I'm using the hd650, and listen to some of everything. Thanks fellas


 

 Have a read of the multi 6as7g review and see if anything appeals
  
 http://the-key.enix.org/~krystal/review-tube-bottlehead.html


----------



## donato

jamiemcc said:


> I was fond of running 6sn7 in the driver slot but never got round to trying the 6F8G


 
 So you prefered the 6SN7 over 12AU7 in the Crack?  Which brands did you try?


----------



## JamieMcC

donato said:


> So you prefered the 6SN7 over 12AU7 in the Crack?  Which brands did you try?


 
  
 I rolled a bunch of 12au7 for about a year before moving to E80cc after which I let go of all but a couple of my 12au7 (check out the speedball resistor mod on the Bottlehead forum to switch between the 12au7 and the sweet spot for running the E80cc ).
  
 After that I would switch between the E80cc and the 6sn7 for the input tube.I only rolled a handful of 6sn7 but had two firm favourites the National 6sn7 VT231 black glass & the Russian Melz 6sn7 (the perforated anode version) I might add that the Melz I only used when listening to LP's it just seemed to have great synergy in my system but for digital I preferred the National.


----------



## barontan2418

Hi. Looking for some help and advice. My Crack with Speedball has an on going issue which I causing the right channel to cut out after about 15 minutes of play. It's been in to a local electronics engineer already once, £140 and its doing the same again. He thought a couple of components on one of the two small speedball needed replacing but having done so unfortunately did not rectify the issue. It will sadden me to do so but it might be the end of the line for my Crack as I cannot afford such costs. The electronics engineer has suggested removing speedball taking it back to original Crack but that would be too much of a retrograde step for me. Any ideas?


----------



## JamieMcC

barontan2418 said:


> Hi. Looking for some help and advice. My Crack with Speedball has an on going issue which I causing the right channel to cut out after about 15 minutes of play. It's been in to a local electronics engineer already once, £140 and its doing the same again. He thought a couple of components on one of the two small speedball needed replacing but having done so unfortunately did not rectify the issue. It will sadden me to do so but it might be the end of the line for my Crack as I cannot afford such costs. The electronics engineer has suggested removing speedball taking it back to original Crack but that would be too much of a retrograde step for me. Any ideas?


 
  
 Sounds like a solder joint problem once the joint heats up as the Crack starts to heat up in your case 15mins a connection expands enough to lose contact. Do you have a soldering iron? If so you could work your way back through the terminals of the effected channel heating up the joints and reflowing the solder. Posting some pics on the Bottlehead forum might be helpful the guys are pretty good at trouble shooting such problems.


----------



## barontan2418

Thanks Jamie. Yes I do have a soldering iron but not certain I could identity those joints applicable to right channel. I did not assemble the myself. Thank again for your reply.


----------



## Tom-s

A way to check for a bad connection is by performing a pin prick test.
 Using a wooden chopstick touch every solder joint.
 When the crackling appears or disappears you've located the bad solder joint.
  
 Edit: be very careful. Keep the other safety advice from the manual in mind.


----------



## barontan2418

Interesting. Its more a total loss of the right channel than crackling. Thanks.


----------



## Allanmarcus

barontan2418 said:


> Thanks Jamie. Yes I do have a soldering iron but not certain I could identity those joints applicable to right channel. I did not assemble the myself. Thank again for your reply.


 

 Just take a simple approach. Reflow all, or as many joints, as you can. They see if that helped. if you want to be systematic, reflow a few joints, then test, then reflow more.
  
 Figuring out which are for the one channel is as easy as following the connection from the RCA to the Pot, then out of the pot. You may need the manual to determine which wire from pot is the channel you are looking for.
  
 Still, if it were me, I would just reflow a section, listen, then reflow another section until all the joints have been reflowed. I would start with the easiest ones.


----------



## barontan2418

Thanks Allen.In your opinion could component failure be just as likely as a cold joint to cause loss of right hand channel audio after approx 15 min of play?


----------



## buke9

barontan2418 said:


> Thanks Allen.In your opinion could component failure be just as likely as a cold joint to cause loss of right hand channel audio after approx 15 min of play?


I would try the things that the others have mentioned before worrying about bad components. If you have other tubes that would be my first move them on to the others . No one can diagnose your problem from here you have to try some things first. Good luck though.


----------



## Allanmarcus

barontan2418 said:


> Thanks Allen.In your opinion could component failure be just as likely as a cold joint to cause loss of right hand channel audio after approx 15 min of play?


 

 It's possible. It's a good place to start.
  
 Actually, and easier place to start is the source and the cable running from the source to the crack. Switch the left and right plug going into he crack. If the other channel fails then the problem isn't even wit the crack.


----------



## buke9

And if you have a different source that's worth a try easy first then the hard stuff.


----------



## buke9

While we're in troubleshooting mode I have something strange that happens. When I have the Crack and Liquid Carbon plugged into to the Yggy both are fine unless I turn off the Liquid Carbon and the bass gets all distorted I know the solution don't turn the Carbon off but is just a bit strange I'm sure it is and impedance thing with some relay in the Carbon that changes something just though I would share.


----------



## barontan2418

Really impressed with all the advice given. Much thanks to all
 I have already changed the tubes,source and cables to no avail but will certainly follow the soldering route. Thankd again.


----------



## mrravioli

I post this on the WA7 thread but it's always better to hear from both sides.

Hi, I'm considering upgrading from my ODAC/O2 combo for Beyerdynamic T1. I heard good words about tube amps for T1 but currently torn between choices. WA7 is freakin sexy and appreciate the usb-DAC/amp in one design (coz I only listening with my MacBook). Another choice is the Bottlehead Crack. Ive only heard praise on it and it's less than half of the price of WA7 and seems pair well with high impedance cans. However it requires building myself (I'm not experienced in this regard and quite busy these days) and also needs a new DAC to pair with (most likely some ODAC or MODI stuff under $200).

At all rates, the sound is still of prime concern. Would the WA7 deserve the extra cost or the Bottlehead deserve the extra efforts to pair with my T1? And I listen to Classical 90% of my time.


----------



## Tom-s

Building your own amplifier is not something to look at as extra effort.
 It's more fun hobby-wise. It helps you understand the technology you're listening to.
 Crack is a great choice to start with. 
 The biggest advantage of building a crack is everything that comes after.
 And in that, the options are limitless. Flavouring, seasoning and refining it's sound to your personal taste. 
 It's a very versatile amplifier for high impedance headphones.
  
  
 It's all about the journey!: http://www.head-fi.org/t/476650/crack-bottlehead-otl/7800#post_12695818


----------



## mrravioli

tom-s said:


> Building your own amplifier is not something to look at as extra effort.
> It's more fun hobby-wise. It helps you understand the technology you're listening to.
> Crack is a great choice to start with.
> The biggest advantage of building a crack is everything that comes after.
> ...


 

 Thx Tom, I might go the Crack route. Could you also recommend a DAC (with USB) to pair with the Crack? My budget would be $300 and can live with used ones. I did some research but the results was too dazzling and only confuse me more. Should I just buy the Schiit Modi or ODAC for around $100 instead?


----------



## adydula

I use a ODAC with my Bottlehead Crack and a HRT MSii+. Both work well and I can not tell any difference. There is no real need to spend more money here IMO.
  
 Alex


----------



## mrravioli

adydula said:


> I use a ODAC with my Bottlehead Crack and a HRT MSii+. Both work well and I can not tell any difference. There is no real need to spend more money here IMO.
> 
> Alex


 

 Thx Alex.
  
 Actually I'm using a ODAC/O2 combo now. I bought it 2-in-1 for convenience then with no idea of upgrading, so have to shoot for a new DAC since the combo can't be used as DAC only. I was a non-believer of DAC making a difference in sound, be last week I tried to connect my Macbook Pro directly into my O2 (skipping the ODAC) and the sound became noticeably 'flatter' (don't have a big hifi vocabulary, 'flat' is the best word I can think of).
  
 BTW, what's your HP and music style Alex? Can you also compare the O2 (amp part) to the crack? Seems we have very similar taste in equipment so I would take your words seriously.


----------



## Tom-s

I can only comment on the Schiit Modi 2U. It's a great DAC. It plays perfect with my Crack running from my macbook.
 And it looks cool next to the aluminum macbook. Best spend dollar i'd recommend a Modi 2U or multibit.
 Looking second hand is always a good idea. I found a Gustard X20 for cheap that way and use it till today (price of a new Bifrost).
 The only reason i sold the Modi and kept the X20 is the fact that the modding bug got me so hard i just needed to play around with that DAC.


----------



## Allanmarcus

I've used various DACs with my crack, and all work well. Differentiation between DAC is usually subtle unless you have really good ears, and or are trained.

I have a modi multibit on order, and will be getting it next week. I'll try to post comments and impressions with the crack.

You can usually find pre-made cracks used for decent prices. I know of one for sale on another site for $500, and it comes with many tubes, and many upgrades. I've heard it personally, and it sounds good. PM me if interested. 

For $300 I would get a modi multibit, a PeachTree DAC-it2, or a used Bifrost.


----------



## adydula

mrravioli...
  
 You could take the odac apart from the amp but thats a chore for most....best just get a new one...they arent that expensive. The ones out now are REV B sonically no real difference.
  
 I have used several headphones with the ODAC and other amps, for what its worth the ODAC is just ...well a very good dac that doesnt do much except do what its designed to do very well at a great price. I have compared to others and its as good as many others costing much more.
  
 Headpones I use, Audeze LCD2's, AKG 701/2's, AudioTechnica ATH M50's, MSR7's, Beyerdynamic T90's, 1350's, Senn 650's...
  
 All work well with the O2 and ODACand all can be driven to painful levels. The Crack amp is a great option for your higher impedance cans! Sound is different than the O2.
  
 Music style is many different styles, but I like stuff that is very well mastered and recorded. I dont try to fix bad recordings of artists I like by finding a set of headphones or amps to "fix" crappy recordings. I look for neutral electronics, that allow me to hear what headphones can and can not do. The ODAC will allow you to do this.
  
 I like jazz, rock, instrumentals, check out this link I started that has many of the BEST recordings out there.....all kinds of stuff:
  
 http://www.audiocircle.com/index.php?topic=63936.0
  
 Best of Luck and Enjoy!!
 Alex


----------



## Doc B.

> You can usually find pre-made cracks used for decent prices.


 
  
 One thing I would caution buyers of used kits - find out if the seller guarantees that the amp will work when you receive it. There are some very skilled builders out there, and yet we see a fair number of amps sold used coming across our repair bench. Seems sometimes to be due to damage from poor packing. Other times it seems due to less than stellar construction by a maybe less than very skilled builder. We're happy to repair them, it pays my tech's wages. But as a buyer you probably don't want to have to ship an amp to us to get it fixed before you can use it. 
  
 This has been an issue with kits forever. I remember buying Dynaco Stereo 70s that were stunningly crafted underneath (usually by engineers) and Stereo 70s that were a nightmare bird's nest underneath. All built from the same set of instructions.


----------



## mrravioli

adydula said:


> mrravioli...
> 
> You could take the odac apart from the amp but thats a chore for most....best just get a new one...they arent that expensive. The ones out now are REV B sonically no real difference.
> 
> ...




Definitely concur with the 'neutral electronic' concept. Actually not only to the extent of recordings, even to the 'real sound' territory. I'm a classical fan and go to concert as often as I can (fortunately we have a world class orchestra here). IME, the 'true' acoustic sound is no way 'perfect', but definitely perfectly 'detailed'. When I sit in the front rows, I can hear the conductor humming, stomping and even world-class singers have sibilance (which many audiophiles spend thousands of dollars to eliminate)


----------



## adydula

You know I agree with you. When I go to a live concert or band I really listen to what the instruments sound like....when you listen to a trumpet up close or a drum whack....its brutal in real life....I want stuff that allows this to be recreated as best possible. Every once in awhile you get the right material with the right downstream stuff and am amazed. But often than not its a compromise compared to the real world "listening" event.
  
 Alex


----------



## jamesino

How loud of a volume do you guys use when comparing amps? Does the DAC have an impact on how loud you need to turn your amp?
  
 I have a Modi 1 > BHC + SB > HD 650 and listen to music with the knob at 9 o'clock.


----------



## buke9

jamesino said:


> How loud of a volume do you guys use when comparing amps? Does the DAC have an impact on how loud you need to turn your amp?
> 
> I have a Modi 1 > BHC + SB > HD 650 and listen to music with the knob at 9 o'clock.


There might be some differences between some dacs but I doubt very large. If I were comparing between two I would just try to volume match between the two or I could break out the calibrated mic and get the exact volume. 9 o'clock is very loud for my HD 700's from the Crack feed by my Yggy.


----------



## Tom-s

Listening levels on Crack differ with tube's gain and headphone dB SPL / mW. 
 When using a crack with lets say a ecc40 and 5998 it will be way louder at same potentiometer position compared to the standard ecc82 and 6080.
  
 For more useful volume range FAQ #3 helps a lot.


----------



## buke9

tom-s said:


> Listening levels on Crack differ with tube's gain and headphone dB SPL / mW.
> When using a crack with lets say a ecc40 and 5998 it will be way louder at same potentiometer position compared to the standard ecc82 and 6080.
> 
> For more useful volume range FAQ #3 helps a lot.


Using a 5998 now I know way it's louder now thanks.


----------



## HOLLOWCOW

So I finally got the CRACK+SB amp and the MODI MULTIBIT combo to pair with my Beyer T90's.
 
It is a solid upgrade over the JDS Element (same components as O2+DAC combo).
the sound is better and more alive than the JDS,
however with the stock tubes I still find the treble too fatigue, and the sound to be a little digital and too much clarity. 
I'm a total noob to tube amps. I had someone assemble it for me. 
I understand the Crack have two types of tubes. the big one is the sound signature and the small one is the power, is this right?
 
 
MY QUESTION IS:
*I'm looking for a new set of tubes to* give it a more "tuby" "lush/warm" sound with nice roll-off to the trebles.
the bass can also be improved. (maybe less in your face and more slow like sennheiser bass. maximum budget of 350$. preferably less.
Ive read some recommendation on the rca 6AS7G and the Tung Sol 5998. but those comments werent about the crack with speedball upgrade and the T90's
 
 
I would really appreciate your recommendation based on your personal experience with this setup.
I would also be really greatfull if you can provide a link to a reliable eBay seller or web store. as all the parameters and brands are very unclear to me.
I could easily buy something else.
THANK YOU!


----------



## Tom-s

From the new tubes i'd recommend the following combination (sub 50$):
  
 - Genalex Gold Lion new production ecc82  (that's the small one)
 - Svetlana 6H13C (not new as you ask but cheap all over the bay, and big bottle shaped*)
  
 The Svetlana gives a very strong bass foundation and more air to the music compared to the average 6080wb (i prefer it to my 6AS7G RCA's).
 The Gold Lion is a great little tube with a nice balanced tubey sound. I prefer it by far over the other new production ecc82 tubes i tried and to the most NOS.
  
 *It excels in real audiophile quality => because big bottles look better.


----------



## JamieMcC

hollowcow said:


> So I finally got the CRACK+SB amp and the MODI MULTIBIT combo to pair with my Beyer T90's.
> 
> It is a solid upgrade over the JDS Element (same components as O2+DAC combo).
> the sound is better and more alive than the JDS,
> ...


 
  
 Another option you could try would be bypassing the Cracks 100uf output capacitors with some Russian 250v 1uf K75 10 capacitors they are only a couple of dollars each and should add bags of character, think full rich juicy mid centric sound with bags of texture plus you should get the roll off you are after. Cheep to try anyhow so thought I would throw the idea out there for consideration..
  
 http://www.enjoythemusic.com/diy/0411/capacitor2.htm
  
 http://www.ebay.co.uk/itm/1uF-250V-Hybrid-PIO-Capacitors-K75-10-Matched-Pair-2-x-0-947uF-/201719646854?hash=item2ef76d8a86:g:HykAAOSwiONYK-Tr


----------



## buke9

hollowcow said:


> [COLOR=454434]So I finally got the CRACK+SB amp and the MODI MULTIBIT combo to pair with my Beyer T90's.[/COLOR]
> 
> [COLOR=454434]It is a solid upgrade over the JDS Element (same components as O2+DAC combo).[/COLOR]
> [COLOR=454434]the sound is better and more alive than the JDS,[/COLOR]
> ...


To me the stock tubes were unusable. It might be the fact that it was used so can't say for sure. I'm also pushing it a bit with HD-700's at 150 ohms but with Tung Sol 5998 and Telefunken 12au7 it is quite nice definitely tamed the highs on the 700's. I have a pair of Tung Sol 6080 Chathams that had a more lush sound but the bass was a bit too boomy I'm thinking this could be from the lower impedance of the 700's don't know will have to wait to try it out on the HD-6xx's sometime around Christmas. I haven't had too much luck with RCA tubes as I have another tube amp that came stock with them and it was just too bright for me switching out the RCA 1626 for a Tung Sol VT-137 and all was right in the world for me.


----------



## HOLLOWCOW

Thank for your replays, I'm going with the ts 5998 nos from the 60s and mullard ECC82.
Hope it will last long enough.


----------



## buke9

hollowcow said:


> Thank for your replays, I'm going with the ts 5998 nos from the 60s and mullard ECC82.
> Hope it will last long enough.


The 5998 is a very good choice I hope you like it. Nothing last forever.


----------



## NightPhotograph

jamiemcc said:


> Another option you could try would be bypassing the Cracks 100uf output capacitors with some Russian 250v 1uf K75 10 capacitors they are only a couple of dollars each and should add bags of character, think full rich juicy mid centric sound with bags of texture plus you should get the roll off you are after. Cheep to try anyhow so thought I would throw the idea out there for consideration..
> 
> http://www.enjoythemusic.com/diy/0411/capacitor2.htm
> 
> http://www.ebay.co.uk/itm/1uF-250V-Hybrid-PIO-Capacitors-K75-10-Matched-Pair-2-x-0-947uF-/201719646854?hash=item2ef76d8a86:g:HykAAOSwiONYK-Tr


 
 I have no prior experience in DIY projects. Can you please tell how you replace 100uf capacitor with 1uf one? Shouldn't the capacity be kept equal when capacitors are replaced?
  
 Cheers


----------



## daltonljj

bypass not replace. its just to have it soldered parallel to the output caps. make sure its in the right direction if the caps you buy have polarity.


----------



## JamieMcC

nightphotograph said:


> I have no prior experience in DIY projects. Can you please tell how you replace 100uf capacitor with 1uf one? Shouldn't the capacity be kept equal when capacitors are replaced?
> 
> Cheers


 

 The 1uf doesnt replace the 100uf capacitor its added by soldering the two leads of the 1uf  capacitor one lead to each of  the same terminals the 100uf is attached to so you have 101uf. As the K75 is a film capacitor doesnt have a +/- polarity like the 100uf electrolytic doesn't matter which way round the leads are connected.
  
 A pic of some in my old Crack
  

  
 Later some teflons bypasses were added to the mix as well


----------



## NightPhotograph

jamiemcc said:


> The 1uf doesnt replace the 100uf capacitor its added by soldering the two leads of the 1uf  capacitor one lead to each of  the same terminals the 100uf is attached to so you have 101uf. As the K75 is a film capacitor doesnt have a +/- polarity like the 100uf electrolytic doesn't matter which way round the leads are connected.
> 
> A pic of some in my old Crack
> 
> ...


 
 Thank you very much for the information. Woaa! that's a giant Crack . Do the capacitors affect sound stage? Crack has somewhat narrow sound stage. Is it possible to improve it a little bit?


----------



## JamieMcC

Going down the standard Crack upgrade path can make a noticeable difference. However its still going to be a more intimate presentation compared to Bottleheads Sex and Mainline headamps.


----------



## Tom-s

I thought to remember you once left SEX as is, because your maximally modded Crack was sounding as good or better?
  
 And @NightPhotograph if you think that Crack is big. Jamie once used one with 100uf PIO cans attached to it externally.


----------



## HOLLOWCOW

Hi guys,
 I found a tung sol 5998 clear top year 1967 from eBay. (bottom getter)
 I understand the clear top are the best quality.
  
 however I thought the clear top were made in the early 50's and not the 60's.
 the tube have green letters writing in the bottom "tung-sol made in usa 3226731-3"
 any thoughts?


----------



## Tom-s

The difference is marginal between those. I had both and kept the 50's version. 
 Any 5998 will be a big step up over the standard 6080 you use now.


----------



## HOLLOWCOW

I can get a 50's version but not a clear top.  
 (for the same price) 190$


----------



## Tom-s

The price is a bit steep for both.
 I think a good Tung Sol 5998 can be had for way less. 
 Theres a few for sale here on the forum. A topic was bumped last week selling 2.
 Use the search.
  
  
 My bad; only ships to US: http://www.head-fi.org/t/779391/great-tubes-for-crack


----------



## HOLLOWCOW

I look everywhere on tubes website and ebay and those are the prices.
 Of course I will prefer to buy from a forum member.
  
 The 5998 clear top from ebay test are:
T1 10,500 105% T2 10,500 105% No gas leak, No shorts, Low microphonics. Tested 4/2016 WE 539C tester calibrated in Q3 2015.

Min new is 10,000gm on this tester
  
is this any good?
will it last 5+ years?


----------



## Allanmarcus

There's a good discussion of various tubes for the Crack on another site. Sorry, I cannot link to it, but if you google
  
 bottlehead crack tube overview driver tubes
  
 and click on the first hit, you will see a good thread.


----------



## HOLLOWCOW

i just need to know if those test results are any good.
 thanks


----------



## buke9

hollowcow said:


> i just need to know if those test results are any good.
> thanks


It is testing as new as far as lasting 5 years depends on use I would imagine have not had my amp but a few months so don't know.


----------



## HOLLOWCOW

OK  guys just one more question before I pull the trigger.
 the same ebay seller offered me a Western Electric *421A* from 1978 for 250$
  
 tests results are:
T1 10,750 T2 10,500 107% / 105% No shorts or gas leaks, low Micros. 1978 vintage double O getters.
is it good results?


----------



## buke9

hollowcow said:


> OK  guys just one more question before I pull the trigger.
> the same ebay seller offered me a Western Electric *421A* from 1978 for 250$
> 
> tests results are:
> ...


This place has 5998 Chathams for $100 and $150 
http://www.vacuumtubes.net/RES%20Audio%20pages/6080.html


----------



## HOLLOWCOW

thanks for that! 
 I prefer the we 421A, however I don't know if those test results are good. (noob here)


----------



## buke9

hollowcow said:


> thanks for that!
> I prefer the we 421A, however I don't know if those test results are good. (noob here)


It tests new.


----------



## HOLLOWCOW

well the guy want 80$ for shipping.
 while others ask for 10$.
 so its a no.


----------



## buke9

hollowcow said:


> well the guy want 80$ for shipping.
> while others ask for 10$.
> so its a no.


That is a big no!


----------



## JamieMcC

tom-s said:


> I thought to remember you once left SEX as is, because your maximally modded Crack was sounding as good or better?
> 
> And @NightPhotograph if you think that Crack is big. Jamie once used one with 100uf PIO cans attached to it externally.


 
  
 The Sex has better resolution and soundstaging than the Crack period no matter what the mods. But the Sex's presentation is a bit cooler than the Cracks.
  
 Loquah's detailed reviews of the Crack, Sex and Mainline are spot on imho check out the link
  
 http://www.head-fi.org/t/683012/bottlehead-amplifier-discussion-comparison-thread-crack-sex-mainline


----------



## SP Wild

What's the 'official' way of securing the top plate/guts to the wooden base? Don't want the damn thing lifting up every time I am pulling a cable out.... Or smashing more tubes. 

Other than this horrendous flaw... Speedball crack is indeed a magnificent pairing with HD650s. 

Compared to the stock Valhalla 2, the treble is mores extended as is the bass. The stock Valahalla2 isn't as extended on both ends. Lacks sub bass and unable to decode and correctly render/resolve/separate frequencies around middle c. The crack sounds more correct to me.


----------



## Allanmarcus

sp wild said:


> What's the 'official' way of securing the top plate/guts to the wooden base? Don't want the damn thing lifting up every time I am pulling a cable out.... Or smashing more tubes.


 
 Quite simple. Hold the plate down with one hand, carefully remove what you need to remove with the other hand.


----------



## buke9

sp wild said:


> What's the 'official' way of securing the top plate/guts to the wooden base? Don't want the damn thing lifting up every time I am pulling a cable out.... Or smashing more tubes.
> 
> Other than this horrendous flaw... Speedball crack is indeed a magnificent pairing with HD650s.
> 
> Compared to the stock Valhalla 2, the treble is mores extended as is the bass. The stock Valahalla2 isn't as extended on both ends. Lacks sub bass and unable to decode and correctly render/resolve/separate frequencies around middle c. The crack sounds more correct to me.


You could screw down the top plate I guess but I don't think that is necessary if you pull the cables out as normal human beings. I don't have a problem one hand to secure the unit and the other to pull the cables. If you think you should be able to yank on the input cables to change them out then you are the problem not the amp. Sorry but I have no sympathy.


----------



## SP Wild

No its not like that at all. I merely assumed that a consumer product housing lethal voltages would... 

Look, nevermind it is an awesome sounding amp. I am stoked.


----------



## JamieMcC

If you use your Crack in a environment where there are children with small inquisitive fingers then personally I think it is essential to take some precautions keeping the amp and power leads well out of reach for starters but also it's easy to add some small right angle brackets on the inside of the wood enclosure which will allow the top plate to. be fastened down and some wire mesh to be added cover the underside just in case.


----------



## HOLLOWCOW

Hi all
 I have a chance to get the 421A from an eBay seller (not to many reviews about him)
 for 280$ including shipping.
  
 http://www.ebay.com/itm/Western-Electric-421A-Electron-Tube-Code-8113-Tested-/252612290412?
  
 he have some sort of image with a test result.
 does it look genuine?
  
 THANK YOU!


----------



## adydula

$280.....way to rich for my pocket!!
  
 I have bought many tubes from Ebay sellers and have had to send some back just because the were really sensitive to movement , vibrations, microphonic, humming, shorted heater....
  
 If I were to spend $280 on a single tube I would want a solid assurance you can return and get a refund if there are any issues on your end.
  
 A fool and his money are soon parted, just be careful....
  
 Good Luck!
 Alex


----------



## HOLLOWCOW

adydula said:


> $280.....way to rich for my pocket!!
> 
> I have bought many tubes from Ebay sellers and have had to send some back just because the were really sensitive to movement , vibrations, microphonic, humming, shorted heater....
> 
> ...


 
 I will ask for 14 days return grantee, if he answer yes is it a solid assurance?
 also, he said the tube is from 1981. is it possible?
 In his pics I can barley see the hard yellow print that is related to the 421A. it look more grey to me. and the font is very different than all that i've seen!


----------



## DavidA

hollowcow said:


> I will ask for 14 days return grantee, if he answer yes is it a solid assurance?
> also, he said the tube is from 1981. is it possible?
> In his pics I can barley see the hard yellow print that is related to the 421A. it look more grey to me. and the font is very different than all that i've seen!


 
 I think you might be better off with 2 TS-5998, the WE421A is really over priced IMO.


----------



## HOLLOWCOW

davida said:


> I think you might be better off with 2 TS-5998, the WE421A is really over priced IMO.


 
 I couldn't find a clear top ts 5998 anywhere (best version) and they coast 200$ anyway. 
 if this WA 421A is legit I would prefer it for 280$.


----------



## DavidA

hollowcow said:


> I couldn't find a clear top ts 5998 anywhere (best version) and they coast 200$ anyway.
> if this WA 421A is legit I would prefer it for 280$.


 
 While I have a pair of WE421A I wouldn't say they are worth the price premium over any TS5998, this is just my opinion after using these tubes for a few years now.  To me they are not better sounding, just a very slightly different sound signature, again IMO and YMMV.
  
 This is what I would spend my funds on: http://www.ebay.com/itm/1967-NOS-TUNG-SOL-5998-TUBES-DOMINO-BLACK-PLATE-6080-421A-TYPE-PAIRS-AVAILABLE-/182262920711?hash=item2a6fb77607:g:Rv0AAOSwzgRW0e5k


----------



## buke9

davida said:


> While I have a pair of WE421A I wouldn't say they are worth the price premium over any TS5998, this is just my opinion after using these tubes for a few years now.  To me they are not better sounding, just a very slightly different sound signature, again IMO and YMMV.
> 
> This is what I would spend my funds on: http://www.ebay.com/itm/1967-NOS-TUNG-SOL-5998-TUBES-DOMINO-BLACK-PLATE-6080-421A-TYPE-PAIRS-AVAILABLE-/182262920711?hash=item2a6fb77607:g:Rv0AAOSwzgRW0e5k


Wow great price for those. If I didn't have to buy a new car yesterday I would pick those up.


----------



## HOLLOWCOW

If I'm goings with the 5998 I would want a clear top version. Besides this guy want 129$ for shipping! He won't accept using Standart usps. Only ups with tons of extra taxes for international buyers. Go figure!
Is there a reason to get a matched pair instead of one? I only have one a slot in my cracking.


----------



## DavidA

hollowcow said:


> If I'm goings with the 5998 I would want a clear top version. Besides this guy want 129$ for shipping! He won't accept using Standart usps. Only ups with tons of extra taxes for international buyers. Go figure!
> Is there a reason to get a matched pair instead of one? I only have one a slot in my cracking.


 
 I have usually bought matched pairs in the past since I was considering an amp which needed match pairs in addition to my BH Crack.
 I've never heard that the clear top version was better but then I've never asked, do you have a link to where you found that the clear top is a better tube?
  
 The tubes I linked to are already sold, figured it was a really good price and was going to get them as a 3rd set.


----------



## JamieMcC

You know the GEC 6080 has the same plate structure as the 6AS7G both made in the same factory while its not at the same level as the 6AS7G version it still is a very nice tube with some similar traites and is a fraction of the price probably one of the best 6080 tubes about. If you study the plate structure you can also sometines find the branded as Valvo for just a few dollars a very nice sounding tube imo
  
 Food for thought
  
 http://www.ebay.com/itm/GENALEX-UK-MADE-FOR-HALTRON-6080-VACUUM-TUBE-IN-ORIGINAL-BOX-/222202692814?hash=item33bc5004ce:gosAAOSwRgJXj4mI


----------



## HOLLOWCOW

Wow this is great news, is the ebay list you provided is a gec 6080? The same Sq?


----------



## Tom-s

The same factory. 
 Also show up as Mullard i think.
  
 Seen here:


----------



## HOLLOWCOW

I got a chance to grab a we 421A or gec 6as7g brown curved or 
MWT A1834 with Black Curved Base and Cup Getter.
All Nib for about the same price each.
I never heard of the MWT A1834 before,will it fit my crack well?
What should I choose for best top end tube for the crack speedball. I would like a great detailels and dynamic, great bass and an overall warmth to the sound. Will pair it with the mullard ECC82 or new jj ec802s.

I would appreciate if you can help me choose the best of the three.
Hard decision!


----------



## Tom-s

GEC A1834 or 421A.
 I saw the MWT 1834 on the bay. I think you get the same SQ from the tube Jamie suggested for 1/3rd the price.
  
 Try E80CC with speedball.


----------



## HOLLOWCOW

Many thanks to you.


----------



## Oskari

jamiemcc said:


> http://www.ebay.com/itm/GENALEX-UK-MADE-FOR-HALTRON-6080-VACUUM-TUBE-IN-ORIGINAL-BOX-/222202692814?hash=item33bc5004ce:gosAAOSwRgJXj4mI




That would seem to be a *Mullard*-made tube…




hollowcow said:


> Wow this is great news, is the ebay list you provided is a gec 6080? The same Sq?







tom-s said:


> The same factory.
> Also show up as Mullard i think.




… which is *not the same as GEC*.


----------



## Oskari

Double post.


----------



## HOLLOWCOW

so considering I ordered the 421A clear top,
 is it worth having the GEC 6080 for a backup? does it have a different sound signature that make it worth having?
 (what is the average price for them?)
  
 I also have the RCA 6AS7G Black Plates as a backup.
 Thank you!


----------



## Oskari

hollowcow said:


> I never heard of the MWT A1834 before,will it fit my crack well?







oskari said:


> There was a manufacturer called M-O Valve Co. (MOV), originally Marconi-Osram Valve Co. This was a GEC (Osram being their brand) and Marconi joint venture. Later on, MOV was owned by GEC and EMI, and even later on by GEC alone. So, MOV was the manufacturer. Brands such as Marconi, Osram, MWT, GEC, etc. appeared.


----------



## HOLLOWCOW

Thanks for the Clarification!


----------



## JamieMcC

oskari said:


> That would seem to be a *Mullard*-made tube…
> 
> … which is *not the same as GEC*.


 

 Well spotted
  
 The GEC made Valvo 6080 tubes I've had have all had the GEC/Marconi Z factory mark on them as well as the Bundesburg Eagle stamp. they have been identicle to my GEC branded 6080 tubes the thing is to learn the plate structures and keep looking and save some cash look for the european codes not just the more well known US codes. The 5998 and GEC 6as7g can be found with different codes on them or even none at all.


----------



## HOLLOWCOW

davida said:


> I have usually bought matched pairs in the past since I was considering an amp which needed match pairs in addition to my BH Crack.
> I've never heard that the clear top version was better but then I've never asked, do you have a link to where you found that the clear top is a better tube?
> 
> The tubes I linked to are already sold, figured it was a really good price and was going to get them as a 3rd set.


 
 I heard it from here: http://www.head-fi.org/t/410326/for-6as7g-tube-rollers-here/2205#post_11736359
  
 and also from Thenewguy007.


----------



## DavidA

@HOLLOWCOW, if you read through the thread the are many different impression on the different types of construction so its hard to say that a clear top will be better than one with flashing.  Also, it was noted by some that the WE is a rebranding of another tube.  Another place that there is much discussion about the 5998/6080/421A is in the Feliks Elise thread:
  
 http://www.head-fi.org/t/813488/feliks-audio-elise-impressions-thread-a-new-start-please-read-first-post-for-summary/3435#post_13025188​,
  
 and in this one:
  
 http://www.head-fi.org/t/782754/feliks-audio-elise-new-thread/13185#post_13006538​ (more exotic tube setups)


----------



## chahooa

I've really enjoyed reading through these threads. I have the crack+speedball and have been happy enough with the stock tubes, but I'm curious to dip my toe in the waters of tube rolling. Can anyone suggest a pretty affordable option that would appeal to me? I like warm and a big soundstage, detail is welcomed as long as its not hard or bright sounding. Thanks!


----------



## buke9

chahooa said:


> I've really enjoyed reading through these threads. I have the crack+speedball and have been happy enough with the stock tubes, but I'm curious to dip my toe in the waters of tube rolling. Can anyone suggest a pretty affordable option that would appeal to me? I like warm and a big soundstage, detail is welcomed as long as its not hard or bright sounding. Thanks!


Sometimes affordable and tubes don't go together too often. Not a tube expert by any means just got into this myself. I'm running HD700's out of the Crack with Tung Sol 5998's and it is very smooth and warms the 700's up to be just about right for me and the bass, soundstage and detail is very good. It is not a cheap tube though I've seen them for up to $349 that is the crazy price I got a used one that test just shy of new for $99. I have some Tung Sol 6080's Chathams that are even smoother but they really want higher impedance cans I think . I'll know at Christmas time when my HD 6XX's come in. I paid $90 for two of the 6080 Chathams. I'm sure there are others here with much more knowledge of tubes that can steer you a little better but this is my take on it so far. The original RCA 6080's were unlistenable on the 700's the bass was just too flabby. 
Tube amps and tubes are a different ballgame to be sure my Amps and Sounds Kenzie amp that cost over 4x's what I paid for the Crack takes tubes that on the high end cost less than $40.


----------



## chahooa

buke9 said:


> Sometimes affordable and tubes don't go together too often. Not a tube expert by any means just got into this myself. I'm running HD700's out of the Crack with Tung Sol 5998's and it is very smooth and warms the 700's up to be just about right for me and the bass, soundstage and detail is very good. It is not a cheap tube though I've seen them for up to $349 that is the crazy price I got a used one that test just shy of new for $99. I have some Tung Sol 6080's Chathams that are even smoother but they really want higher impedance cans I think . I'll know at Christmas time when my HD 6XX's come in. I paid $90 for two of the 6080 Chathams. I'm sure there are others here with much more knowledge of tubes that can steer you a little better but this is my take on it so far. The original RCA 6080's were unlistenable on the 700's the bass was just too flabby.
> Tube amps and tubes are a different ballgame to be sure my Amps and Sounds Kenzie amp that cost over 4x's what I paid for the Crack takes tubes that on the high end cost less than $40.


Thanks for the reply. Do you remember where you found the used Tung-Sol? I know the better or rarer tubes can get pricey. Used doesn't bother me if they work fine.


----------



## buke9

chahooa said:


> Thanks for the reply. Do you remember where you found the used Tung-Sol? I know the better or rarer tubes can get pricey. Used doesn't bother me if they work fine.


https://tubeworldexpress.com/search?q=5998


----------



## ScottFW

chahooa said:


> Can anyone suggest a pretty affordable option...


 
 The least expensive output tube I've tried that actually sounds good is the Svetlana "Winged C" 6H13C. I bought a set of 4 tubes for $34 shipped via ebay from a seller in eastern Europe, and they sound significantly better than the few 6080 tubes I've run (RCA, GE, Sylvania) which all sounded lifeless or muddy to some degree. Granted, the Russian tubes are new and the USA ones have arrived to me with an unknown number of hours on them, so maybe that has something to do with it. The Winged Cs have decent bass, pretty good midrange that doesn't stray excessively warm, and open and detailed highs. Lately I'm using a Tung Sol 7236 which sounds a bit better still (deeper bass, a bit richer midrange) but costs ~4x as much as the Svetlanas.
  
 For affordable input tubes I like the good old RCA clear top 12AU7, but you have a ton of options in 12AU7/ECC82 at whatever price point you like. There's a ton of info on the web for this tube type. If you don't mind swapping a couple of resistors to run them at the proper voltage (or install a little switchboard as some of us have) 12BH7 tubes are also inexpensive, and I have a couple of NOS RCAs that I picked up for cheap that sound better than any of the 12AU7s I've tried.


----------



## JamieMcC

The Svetlana "Winged C" 6H13C is a nice tube at a very affordable price the silver flashing at the base of the tube is a tell tell hallmark of the tube if you look out for this you will soon notice they are often found rebranded in the popular brands and more often than not with premium prices being asked for a NOS tube that normally sells for under $10.
  
 Use a inexpensive Tungsram E80cc ($20) in place of the 12au7 is a great choice with this tube imho.  This was my daily set up for some time the E80cc is a longlife tube 10000hrs+ and the 6H13C are inexpensive so I didnt worry about turning the amp on of an evening and just leaving it on whilst watch a bit of TV saving my premium tubes for times when I could listen without the normal distractions.


----------



## Tom-s

chahooa said:


> Can anyone suggest a pretty affordable option that would appeal to me? I like warm and a big soundstage, detail is welcomed as long as its not hard or bright sounding.


 
  
 The Svetlana 6H5C or 6H13C (equal to my ears) are a good option.
 I wouldn't recommend the RCA clear tops for a warm sound. I think the E80CC Tungsram matches your requirements better. Problem is it prices can ben very high.
 With these it's a good idea to look into the E80CC/12BH7/7119 resistor modifications for best SQ.


----------



## DukeOfYork

Tube sound is much better than SS.


----------



## larcenasb

Just finished soldering in some ClarityCap PX 4.7uF caps to bypass my final two lonely power supply caps. This is likely the end of my Crack upgrading journey which has been going on for almost two years! Not much room left!
  
 Anyone else notice a significant change when bypassing _all_ the power supply caps? I installed the ClarityCaps and noticed a brighter, tighter, and more dynamic sound that wasn't at all harsh but just... live sounding. I then took the ClarityCaps out and noticed dynamics seemed a bit uninspired, bass also seemed to bleed into the lower mids -- things that always did bother me a little before. Put the caps back in again and the soundscape clears up, tightens and the dynamic-range reawakens.
  
 Right now, I'm listening to "Unforgettable" by Nat King Cole while watching a muted video of Sugar Ray Robinson vs. Jake LaMotta VI and this amp just feels like a sublime emotional communicator with serious power reserves.
  
 Happy listening 
 larcenasb, Seattle, WA, USA.


----------



## Tom-s

Interesting to read you found such a great effect with those 2 bypass caps in the PS.
  
 My powersupply is schottky diode rectified like yours but with CLCLC and with a 120uf film cap as last PS capacitor. 
 Fitting 730uf caps for the others only made a very minor change, if any at all.
  
 Nice padding on your 240's! DIY"?


----------



## attmci

Recent discussion with @HOLLOWCOW. 
  
Hi there Conversation between HOLLOWCOW and me
[img]http://cdn.head-fi.org/e/ec/38x38px-ZC-ec832a9a_avatar-120-1.jpg[/img]
HOLLOWCOW
 Nov 20, 2016 at 9:08 pm

 Hi there,
 In looking for a ts 5998 clear top or a good we 421a for my crack speedball and Beyer dynamic t90.
 As I understand these are the best tubes for them. I am looking for a great overall Sq with warmth and lush sound but great details too. Will paire them with the mullard ECC82 from the 60s. And maybe a future telefunken ecc82.

 The thing is I really can't find a good and legit 5998 clear top or 421a. I found some on eBay but they all look shady and fake. Too risky for a 200$ single tube.

 I hope you could guide me out where to look at, or even better Know a forum user who sell his 
	

	
	
		
		

		
			




  

[img]http://cdn.head-fi.org/3/35/38x38px-ZC-3581259e_file.jpeg[/img]
attmci
 Nov 20, 2016 at 9:30 pm

  Check this: http://www.head-fi.org/t/813488/feliks-audio-elise-impressions-thread-a-new-start-please-read-first-post-for-summary/3420
  
 Stavros @rosgr63 could have the tubes you want.
  
 Ebay is not risky if the seller has over 99.7% reputations. But you have to be patient.
  
 For your needs, you best bet are GEC 6AS7G/7316 
  
 Tube rolling is fun. BTW, if you are brave enough, you can try 2 X 6BL7 as output tubes. Just amazing.


[img]http://cdn.head-fi.org/e/ec/38x38px-ZC-ec832a9a_avatar-120-1.jpg[/img]
HOLLOWCOW
 Nov 21, 2016 at 2:22 am

  also, What do you say about this tube as a driver tube? does it seem legit?
http://www.ebay.com/itm/1x-ECC802S-Telefunken-Balanced-Long-plates-tube-valvo-Rohre-/182282441215?hash=item2a70e151ff:g:7q4AAOSw8w1X2qlV
 I heard it suppose to be the best.
  
 and also this simense ec82 at half the cost (but maybe less sq)
http://www.ebay.com/itm/321862437476?ul_noapp=true
  
 or maybe this?
http://www.ebay.com/itm/ECC82-Telefunken-NOS-COIN-BOTTOM-12-3-12-4mA-10-5mA-100-9600-/322282768049?hash=item4b098cc6b1:g:gSAAAOSwYIxX8876
  
 hope you can help me out with the decision 
  

  

[img]http://cdn.head-fi.org/3/35/38x38px-ZC-3581259e_file.jpeg[/img]
attmci
 Nov 21, 2016 at 4:57 am

  None of those can compete with a 7316.  


[img]http://cdn.head-fi.org/e/ec/38x38px-ZC-ec832a9a_avatar-120-1.jpg[/img]
HOLLOWCOW
 Nov 21, 2016 at 5:24 am

 7316 I searched for them on eBay but couldn't find anything.
 Does it fit into the crack?
 No mods needed?
  

[img]http://cdn.head-fi.org/e/ec/38x38px-ZC-ec832a9a_avatar-120-1.jpg[/img]
HOLLOWCOW
 Nov 21, 2016 at 8:22 am

  attmci you are my hero!
 I'm ordering a pair of WE 421A from Stavros. looking great and legit.
 I was so lost but now i'm found!
 He's the man! so glad I found him.
 they are NIB Double D getters at the bottom, clear tops.
 tested 97% both section (I believe that is a good result.)
 on a calibrated Jackson 648 No shorts or leakages.
  
 now for the driver tube, do you know if the 7316 are the best match? I tried looking for them on eBay but couldn't find anything.
  
 anyway, Thank you so much for the reference!
  
  
  

  

[img]http://cdn.head-fi.org/3/35/38x38px-ZC-3581259e_file.jpeg[/img]
attmci
 Nov 21, 2016 at 6:21 pm

  Nice. How much did he ask for one tube? Should give you a discount without those ebay fees. 
	

	
	
		
		

		
		
	


	





[img]http://cdn.head-fi.org/e/ec/38x38px-ZC-ec832a9a_avatar-120-1.jpg[/img]
HOLLOWCOW
 Nov 22, 2016 at 2:29 am

 He asked for xxx for one Unit.
 Including shipping
  

[img]http://cdn.head-fi.org/3/35/38x38px-ZC-3581259e_file.jpeg[/img]
attmci
 Nov 22, 2016 at 11:36 am

  Better than the market price .  Hope you will like them. 


[img]http://cdn.head-fi.org/e/ec/38x38px-ZC-ec832a9a_avatar-120-1.jpg[/img]
HOLLOWCOW
 Nov 22, 2016 at 3:50 pm

 I hope so too!
 How much do you think they are worth if I don't like the sound (I have a doubt it will happen)
 The pair Is matched NIB. Rare cleartop from the 50s with double d Getter.
 Also the test were 97% for both sections.( I don't know what it means).

 It seems better then the ones I found on eBay for 250+.
  
  

[img]http://cdn.head-fi.org/3/35/38x38px-ZC-3581259e_file.jpeg[/img]
attmci
 Nov 22, 2016 at 10:47 pm

  To be honest, as soon as you open the box, it's a used tube. Lost $80 in value......... LOL


[img]http://cdn.head-fi.org/e/ec/38x38px-ZC-ec832a9a_avatar-120-1.jpg[/img]
HOLLOWCOW
 Dec 6, 2016 at 5:49 pm

  where do you get your HIREZ audio files?
 I hear a noticeable difference between mp3 and 16/96 FLAC.
 I wonder id a DSD/FLAC 24/192 will give me better results.

  

[img]http://cdn.head-fi.org/3/35/38x38px-ZC-3581259e_file.jpeg[/img]
attmci
 Dec 6, 2016 at 10:10 pm

https://www.oppodigital.com/hra/dsd-by-davidelias.aspx


[img]http://cdn.head-fi.org/3/35/38x38px-ZC-3581259e_file.jpeg[/img]
attmci
 Dec 6, 2016 at 10:17 pm

  You DAC has to support the DSD. The next to mod is the after market headphone cable. LOL


[img]http://cdn.head-fi.org/e/ec/38x38px-ZC-ec832a9a_avatar-120-1.jpg[/img]
HOLLOWCOW
 Yesterday at 12:04 pm

  does the modi mb support it?
 I know it support  24/192

  

[img]http://cdn.head-fi.org/3/35/38x38px-ZC-3581259e_file.jpeg[/img]
attmci
 Yesterday at 9:54 pm

  I don't know about modi. The price of the DAC should close to the cost of your headphone.


[img]http://cdn.head-fi.org/3/35/38x38px-ZC-3581259e_file.jpeg[/img]
attmci
 Today at 10:54 am

 I am totally agree with this guy: http://www.audiostream.com/content/dsd-v-pcm-file-comparison-16441-2496-24192-64x-dsd-128x-dsd#UTMTpVt4IHBQkOpv.97


----------



## larcenasb

tom-s said:


> Interesting to read you found such a great effect with those 2 bypass caps in the PS.
> 
> My powersupply is schottky diode rectified like yours but with CLCLC and with a 120uf film cap as last PS capacitor.
> Fitting 730uf caps for the others only made a very minor change, if any at all.
> ...


 
 Hi!
  
 Yeah, the 470uF caps didn't make a clear-cut difference to me. Although the choke and schottky diodes were already installed and alone made improvements to dynamics and a space-black background, so I wonder how the 470uFs would fare w/o the choke and diodes (I may try someday!).
  
 Those pads are the Brainwavz pleather earpads and they're super comfy! My ears no longer touch the edge of the pad causing discomfort after 30 mins of listening. Bass solidity is also improved as the seal the earpads make is very good.
  
 So you haven't bypassed all the PS caps? If not, the ClarityCap PX don't cost much if you want to experiment. Sometime down the line I'll even try cheapo orange drops to see if they make as much of a difference. Cheers and happy listening!


----------



## larcenasb

chahooa said:


> I've really enjoyed reading through these threads. I have the crack+speedball and have been happy enough with the stock tubes, but I'm curious to dip my toe in the waters of tube rolling. Can anyone suggest a pretty affordable option that would appeal to me? I like warm and a big soundstage, detail is welcomed as long as its not hard or bright sounding. Thanks!


 
 Compared to most 12AU7 tubes, I found the 'RCA 1950s black-plates square-getter' to be the epitome of what you're asking for. Very lush and warm and doesn't sound as closed-in or constricted as many other 12AU7 tubes. They can be found on auction sites for 20 bucks a pair or less if you're patient. Hope you find the sound you're hoping for!


----------



## attmci

chahooa said:


> I've really enjoyed reading through these threads. I have the crack+speedball and have been happy enough with the stock tubes, but I'm curious to dip my toe in the waters of tube rolling. Can anyone suggest a pretty affordable option that would appeal to me? I like warm and a big soundstage, detail is welcomed as long as its not hard or bright sounding. Thanks!


 
 http://www.ebay.com/itm/Quad-5814-CBS-BLACK-PLATE-D-getters-tested-strong-matched-/132024648195?hash=item1ebd484203:g8oAAOSw2xRYRPX2


----------



## cddc

Just completed my Crack assembly couple of days ago.
  
 Really like its appearance...but above all it sounds fabulous in its stock form...crystal clear with dead silent background on my HD650
  
 will do the Speedball upgrade shortly...but not sure if the Speedball upgrade will reduce the fun of tube rolling?
	

	
	
		
		

		
		
	


	



  
 Here are some pics of my Crack:


----------



## i luvmusic 2

cddc said:


> Just completed my Crack assembly couple of days ago.
> 
> Really like its appearance...but above all it sounds fabulous in its stock form...crystal clear with dead silent background on my HD650
> 
> ...


 
 I hope that 100uf cap wouldn't touch the headphone jack terminals.


----------



## DukeOfYork

looks good


----------



## dede4metal

Hi guys! With my Bottlehead when the volume is low I can hear a stron hiss. When the volume is medium the hiss goes away but then it comes back. This happens to the Crack connected to it's own main and no input at all... any suggestion?


----------



## ScottFW

dede4metal said:


> Hi guys! With my Bottlehead when the volume is low I can hear a stron hiss. When the volume is medium the hiss goes away but then it comes back. This happens to the Crack connected to it's own main and no input at all... any suggestion?


 
  
 Could be a wonky tube.
  
 I've also gotten significant audible hiss from other tubed gear (not my Crack) due to sub-optimal impedance matching between source and load. What headphones are you using?


----------



## dede4metal

scottfw said:


> What headphones are you using?


 
 I have a pair of Beyerdinamic T1 2nd, the thing is it was not doing it in my old house, now I have moved to this new one and it just sounds strange with this hiss and, funny enough, if the volume is very low i can hear the local radio! I know there is a local antenna and I think I am picking up that... strange!


----------



## Krit

Do you have the speedball install?? I remember reading from the Speedball installation instruction that the Speedball will act like an antenna and will pick up RF interference if you are close to radio tower and there is a strong RF tower near by.


----------



## Krit

dede4metal said:


> I have a pair of Beyerdinamic T1 2nd, the thing is it was not doing it in my old house, now I have moved to this new one and it just sounds strange with this hiss and, funny enough, if the volume is very low i can hear the local radio! I know there is a local antenna and I think I am picking up that... strange!


 
 Do you have the speedball install?? I remember reading from the Speedball installation instruction that the Speedball will act like an antenna and will pick up RF interference if you are close to radio tower and there is a strong RF tower near by.


----------



## Doc B.

krit said:


> Do you have the speedball install?? I remember reading from the Speedball installation instruction that the Speedball will act like an antenna and will pick up RF interference if you are close to radio tower and there is a strong RF tower near by.


 
 Nope. ANY tube circuit can be susceptible to RFI. The Speedball, by virtue of its high impedance, actually improves the situation by isolating the circuit from any RFI coming in through the power supply.


----------



## Krit

doc b. said:


> Nope. ANY tube circuit can be susceptible to RFI. The Speedball, by virtue of its high impedance, actually improves the situation by isolating the circuit from any RFI coming in through the power supply.


 

 My bad Doc, just went and re-read the Speedball Manual and its just what you said. I mis-read it. BTW just finish installing my Crack w/ Speed Ball. All I have to say is wow!!! The Crack got me up almost to 3:00AM eveyday (Its 1:53AM now in Bangkok Thailand). I just can't and don't want to take my headphone off, ha!


----------



## HOLLOWCOW

Anyone heard of the MWT A1834 valve?
And can compare it to the gec 6as7g?


----------



## Tom-s

It's the same tube with a different label. So "yes".


----------



## JamieMcC

hollowcow said:


> Anyone heard of the MWT A1834 valve?
> And can compare it to the gec 6as7g?


 

 Yes they are both the same tube made in the same factory


----------



## HOLLOWCOW

Thanks,
 Love my 421A, is it worth to try it out?


----------



## JamieMcC

hollowcow said:


> Thanks,
> Love my 421A, is it worth to try it out?


 
  
 The GEC 6as7g is often referred to as the "Super Tube" and the "Holy Grail" of all 6AS7Gs but the thing is you really need a hot rodded Crack to appreciate what they have to offer.
  
 When you start adding up the cost of a hot-rodding a Crack up with mods and premium tubes better sonic value can be found by moving higher up the Bottlehead ladder.
  
 Saying that I think a maxed out Crack paired with a high Z phone like the on T1 or HD800 is a pretty special amp that has a iconic timeless look which for me aesthetically makes it the best looking of all the Bottlehead. headphone amps


----------



## Tom-s

To add to @JamieMcC 's post:
  
 Budget upgrades (the most worthwhile) for Crack:
  
 1. FAQ #3 + E80CC/ECC40 switch mod (10$) (more volume control and optimization for tube rolling)
 2. Schottky rectifiers to PS (20$) (silent background)
 3. Choke in PS (20-30$) (even more silent background)
 4. Output capacitor upgrade (Russian PIO's sub 50$, Mundorf film 120$)
 5. Bypass capacitors (FT-3 0.1uf  in output and maybe some for PS, 10-20$)
 (6. (Film cap PS 50$+) maybe not worth it.)
  
 For only 120$ Crack's internals are optimized.
  
 Tubes can be made as expensive as you like.
 I'm currently using a 25$ set of tubes as my favorites.


----------



## HOLLOWCOW

tom-s said:


> To add to @JamieMcC 's post:
> 
> Budget upgrades (the most worthwhile) for Crack:
> 
> ...


 
 problem is someone built it for me with the sb upgrade and shipped it to me.
 I don''t know how to do this stuff and the modders community is small if any in my country.


----------



## JamieMcC

Lets not forget a budget Stepped attenuator $40ish for a Valab essential imo for passing through those micro details that the film caps choke and premium tubes can give.
  
 FWIW I have tried both 100uf Mcap Mundorfs and Russian PIO with teflon bypass's both are great choices and I have thought them a step up from the Solen, JFX, Daytons I have also used.


----------



## Tom-s

Oh forgot about that one! (I removed the volume control completely to get best results).
  
 Edit: Cheapest too. If you have pre-amp.


----------



## hy931208

I've had nightmares about forgetting to turn off my amp before I went to bed.


----------



## buke9

hy931208 said:


> I've had nightmares about forgetting to turn off my amp before I went to bed.


Why?


----------



## hy931208

They get really hot lol, it's like walking outside and suddenly worried about whether or not you've turned off your stove


----------



## HOLLOWCOW

Today the electricity stopped working a few times during the day on my whole neighborhood, the electric company said there is a high voltage problems and that they working to fix it.


I wonder if it can harm the crack when it is plugged to the wall outlet but the the amp is set to off?
Is there any risk to damage the tubes? The amp?
Do I have to disconnect the power cable untill the electricity will be stable again?


----------



## Kozic

hollowcow said:


> Today the electricity stopped working a few times during the day on my whole neighborhood, the electric company said there is a high voltage problems and that they working to fix it.
> 
> 
> I wonder if it can harm the crack when it is plugged to the wall outlet but the the amp is set to off?
> ...


 
 If the amp is off it would have to be HIGH voltage like lighting high.


----------



## adydula

Santa brought a set of Beyer T1 G2's to my stocking and I have had a few days to listen and compare these on my Speedball Crack with my "old friends" T90's....
  
 I was a bit concerned that the Crack might nor push the 600 ohm T1's to a good listening level....well after swapping a few things around yesterday and letting the crack to warm up for several hours my short term conclusion is it does a wonderful job with the T1's as well as the T90's.
  
 I have several Schitt audio products, both SS and tubes, as well as several other DIY amps.
  
 Their are other amps that are indeed "clearer" or more transparent, but the overall presentation of these cans on the Crack is just very different, a bit warmer and musical to my ear....
  
 Its an amp even if others might be "better" I would never sell or get rid of...its that nice of an amp...a simple design that just works very well for an OTL amp!!
  
 Happy New Year!
 Alex


----------



## adydula

dp...sorry!!


----------



## benjaminhuypham

Does anyone know how to connect a Bottlehead Crack to a Silicon Arts Next Class Si2 DAC? 
The main source would be music from my computer. I don't know what cables are needed. Any help will be appreciated.


----------



## adydula

From their site:
  

Inputs​1 Digital Input (S/PDIF), Single Ended (RCA)Outputs​1 Stereo Pair, Single Ended (RCA)
  
 Pair of RCA to RCA from the outputs to the Crack RCA inputs.
 Output of S/PIDF to DAC Input.
  
 Looks like this is not a USB dac...so your computer has to have a S/PIDF output or a audio card that does.
 from a review:"plus the Si2 DAC doesn't have the right inputs for a computer-based system (meaning like USB)"
  
 Alex
  
  DIGITAL INPUT : S/PDIF digital input terminal. Digital output signals from CD players and transports can be used.
  After the DAC unit is settled into its position, connect digital output (S/PDIF) of CD player/transport to the INPUT terminal. After connecting such input device, connect “OUTPUT” left and right terminals to devices such as preampliers.
  
 https://www.amazon.com/C2G-Cables-29114-Velocity-Digital/dp/B0002J2B7E/ref=sr_1_2?ie=UTF8&qid=1483049544&sr=8-2&keywords=spdif+cable


----------



## benjaminhuypham

Thanks a lot for your help Adydula. It seems like this one would work https://www.amazon.com/Signstek-Coaxial-Converter-Decoder-Analogue/dp/B00FEDHHKE/ref=sr_1_2?ie=UTF8&qid=1483052667&sr=8-2&keywords=S%2Fpdif+to+usb but I'm not really sure.

I guess I'll have to use a pair of RCA to RCA as you mentioned to connect the Amp to the DAC, then will hook up a S/PDIF coax cable to the converter and finally use a USB cable to connect the converter to my computer.


----------



## adydula

You may just get simple USB dac....versus all these "compromises", cables, convertors and connections....??
  
 You can get a good dac for $100.....
  
 Food for thought
  
 Alex
  
 Note: The device u linked to has a dac in it according to its description and you already have one? Dont think this is what your wanting to do...if u really want to use this dac you have then this is not the box IMO.


----------



## TeediuS

Finally stopped my tubes rolling.....off of my unit.

Had them all loose before, with a few close calls of knocking one and dominos to the others, least they're all secure now. 

If anyone is interested, 19mm for 6080 and 12.5mm holes for 12au7 tubes. 

(Had a novel idea to wire them all up with switch boxes, save having to roll them )


----------



## vintinfinity

teedius said:


> Finally stopped my tubes rolling.....off of my unit.
> 
> Had them all loose before, with a few close calls of knocking one and dominos to the others, least they're all secure now.
> 
> ...




That's a great room display and holder for your tube collection. Really cool. 

Hd650 with the BH Crack is such a great combo! Are those HD800 as well?


----------



## TeediuS

I got the 650 and 800S on the same day, as couldn't decide in the shop, 800S sounded so clear, though the 650 sounded fun. 

Thing is, in the three months or so I've had them, 800S have had ~99% of the air time, amazing detail that just keeps drawing me back to them (of all my headphones)


----------



## JamieMcC

teedius said:


> Finally stopped my tubes rolling.....off of my unit.
> 
> Had them all loose before, with a few close calls of knocking one and dominos to the others, least they're all secure now.
> 
> ...


 
  
 Nice idea, but whats with the blue tape on your Crack enclosure not glued yet?


----------



## Tom-s

adydula said:


> You may just get simple USB dac....versus all these "compromises", cables, convertors and connections....??
> 
> You can get a good dac for $100.....
> 
> ...


 
  
 He quotes he already has a 1000$+ DAC, so why not use it? I do get your point on the extra connections and all.
  
 The product he linked has a DAC in it but can also be used as a simpel USB -> Coax, digital -> digital converter. For that price it's worth the try.


----------



## benjaminhuypham

tom-s said:


> He quotes he already has a 1000$+ DAC, so why not use it? I do get your point on the extra connections and all.
> 
> The product he linked has a DAC in it but can also be used as a simpel USB -> Coax, digital -> digital converter. For that price it's worth the try.




Honestly, I won this DAC from a prize draw at RMAF. It is listed over $1000 and I'm very curious to see how big of an improvement expensive DAC makes. It has been sitting in a basement for a while and now is a good time to actual use it. Thanks all for your help. I'm getting a converter anyway to see if it works.


----------



## Allanmarcus

My guess is that whatever gains one gets from a high end DAC will be lost with a cheap converter. Mutec makes some high end converters, but you would be better off just buying a new DAC rather then getting the muted.
  
 I recommend just selling the DAC for no less than $265 and then just get a Mimby. If you think you can get more for it, like $500, get a used Bimby, or pocket ehe money and get a Bimby.


----------



## TeediuS

jamiemcc said:


> Nice idea, but whats with the blue tape on your Crack enclosure not glued yet?


 
 that's right.  got the glue, and some wood oil, but hadn't stained it yet....and glad, thinking i might paint it black now too.


----------



## vintinfinity

Edit: extra post


----------



## vintinfinity

benjaminhuypham said:


> Honestly, I won this DAC from a prize draw at RMAF. It is listed over $1000 and I'm very curious to see how big of an improvement expensive DAC makes. It has been sitting in a basement for a while and now is a good time to actual use it. Thanks all for your help. I'm getting a converter anyway to see if it works.




A decent sound card with pci-e could be a nice digital coaxial source if you find the right model. Assuming you have expansion ports available


----------



## adydula

I would sell it and get a less complicated connections solution.....but hey its your $$$$ please let us know what you think???
  
 Alex


----------



## JamieMcC

benjaminhuypham said:


> Does anyone know how to connect a Bottlehead Crack to a Silicon Arts Next Class Si2 DAC?
> The main source would be music from my computer. I don't know what cables are needed. Any help will be appreciated.


 
  
 I think it would be well worth trying a converter you could probably pic up a decent used one to try for not a lot of cash and that way you can move it on at minimal cost. I remember looking at the J kenny ones think the MK III or the current one I think is the Ciunas. Just to a search for usb to s/pdif on ebay and select the used listings should bring up plenty of choices to read up on. Something will turn up if you keep your eyes open or post a wanted add perhaps


----------



## buke9

Have a great New Year everyone!


----------



## adydula

Happy New Year and Great Listening!\
  
 Alex


----------



## benjaminhuypham

Happy New Year folks! Thanks all for your advice, I'll update when I receive a converter. The Bottlehead Crack is a very special amp, greeting to all owners .

Benjamin


----------



## ElMariachi

Hi everyone, I just purchased a bottlehead crack that is already built and I want to add the speedball upgrade. I am looking for someone who can install it for me as I have no experience or the equipment to accomplish the job. Any suggestions would be greatly appreciated! Thank you.


----------



## Doc B.

I think you should try it yourself. That is the whole point of these kits, to get some good sound and to learn something new at the same time.


----------



## buke9

doc b. said:


> I think you should try it yourself. That is the whole point of these kits, to get some good sound and to learn something new at the same time.


I agree with this also. I was going to assemble one myself but got such a good price on one assembled I couldn't pass up and waiting on the Speedball to be delivered so I can install it myself.


----------



## adydula

Guys I have had a Bottlehead Crack with Speedball for almost a year now and its a very, very good amp to be used with Beyerdynamics T90's and T1's.

I recently got a set of the newer T1's and they are indeed a magical pairing...with a well recorded / mastered song they are surprisingly good.

The depth and layering with this OTL and Beyers are really amazing.

If you think you might want to venture into the DIY area of this hobby the Bottlehead Crack is "the" kit to start with...especially if you like the nostalgic vacuum tube "glow"...lol

Alex


----------



## ElMariachi

doc b. said:


> I think you should try it yourself. That is the whole point of these kits, to get some good sound and to learn something new at the same time.



Alright, Ill give it a shot. Thanks for the words of encouragement!


----------



## jedi

I am a proud crack + speedball owner thanks to Bottlehead for the last two years.  I've been feverishly lurking the 536 pages in this thread for the past year and even branching into other forums (bad, bad, bad jedi).  Anyway, I have all the tools to disassemble desolder, solder, etc to upgrade my caps and the gear under the hood but alas!  I find myself struggling to source a build that has upgraded and presents a way for me to get in touch with the OP and ask which items to remove.
 Specifically I am looking to replace the knob, the caps, the resistors. 
  
 I love the crack thus far but I would love it even more to rock out these Sennheiser HD6xx headphones that came in during the holidays.  Would any of my fellow headfiers have a few reference posts I can use to help me out?
  
 Thanks!


----------



## Allanmarcus

I highly recommend this knob

https://www.amazon.com/gp/product/B00X773QEU
$7
There are silver knobs too. Usually I prefer a bright sound, but for some reason, I liked the dark knob 

I also highly recommend you upgrade the pot first as that will give you the biggest upgrade in SQ. You can go crazy with pots, but if you want a tried and true inexpensive upgrade, get a blue velvet. You will need a Dremel or file to enlarge the holes for the pot, but that is very easy. This is the pot I got and I'm thrilled with it. Channel balance is perfect, and volume control is much more precise. 

http://www.ebay.com/itm/Japan-ALPS-RK27-VOLUME-Potentiometer-Dual-100K-100KAX2-Slotted-/320816794126?hash=item4ab22bca0e:g-QAAMXQrNtRzvTh
$11


----------



## deserat

jedi said:


> I am a proud crack + speedball owner thanks to Bottlehead for the last two years.  I've been feverishly lurking the 536 pages in this thread for the past year and even branching into other forums (bad, bad, bad jedi).  Anyway, I have all the tools to disassemble desolder, solder, etc to upgrade my caps and the gear under the hood but alas!  I find myself struggling to source a build that has upgraded and presents a way for me to get in touch with the OP and ask which items to remove.
> Specifically I am looking to replace the knob, the caps, the resistors.
> 
> I love the crack thus far but I would love it even more to rock out these Sennheiser HD6xx headphones that came in during the holidays.  Would any of my fellow headfiers have a few reference posts I can use to help me out?
> ...


 
  
 Just for clarity's sake.  Are you asking for a link to a post ( forum, blog, or other ) that has detailed instructions on how to upgrade the Crack? Failing that for links to a post of an upgraded crack that has contact information?

 I've not seen any detailed upgrade instructions.  But if you browse the Bottledhead forums, there are lots of discussion of upgrade paths, and potential parts; Caps, Pots, etc... I've not seen any good instructions...


----------



## Tom-s

I think that's because every "upgrade" or replacement is simply a unique one every time. 
 Replacing a volume knob = remove the old and install the new. If it doesn't fit, make it fit and continue. 
 Same with caps, the rectifier, the choke's, the volume pot, everything really.
 FAQ #3 is described in Bottlehead's Crack FAQ on the forum.


----------



## i luvmusic 2

Start a thread regarding your upgrade in BH forum lots of helpful fellas up there.


----------



## Elber

I have a crack with speedball. A year ago I put an Alps, it is better than the original but not much. A month ago I put a TKD 2CP 2511, it's expensive but when you hear it seems cheap. The improvement is spectacular


----------



## Allanmarcus

elber said:


> I have a crack with speedball. A year ago I put an Alps, it is better than the original but not much. A month ago I put a TKD 2CP 2511, it's expensive but when you hear it seems cheap. The improvement is spectacular


 
  
This one?
  
http://www.partsconnexion.com/tkd_64185.html
$99
  
What's the implication of the 10K vs 100K? I would if a 10K Alps pot would sound as good to you?
  
 Found the 100K version:
 http://www.partsconnexion.com/tkd_64187.html
 $99
  
 I also found some very positive discussion on the TKD on the BH forum. Very interesting. Something to put on my Christmas list now 
  
 All that said, the $11 Alps upgrade is great bang for the buck.


----------



## adydula

What "spectacular" sonic improvements "exactly" do you get withe replacing the volume pot???
 Inquiring minds want to know?
  
 Mechanical build ok, sonics hmmmm??
  
 Alex


----------



## Tom-s

The same way people find resistors to sound different. 
 A different volume pot means different resistors in the signal pathway. 
 I had great results going from stock to the Valab stepped attenuator.


----------



## JamieMcC

tom-s said:


> The same way people find resistors to sound different.
> A different volume pot means different resistors in the signal pathway.
> I had great results going from stock to the Valab stepped attenuator.


 

 Yes I have also had good results with the 100k Valab stepped attenuator and used it in a couple of builds now.


----------



## Allanmarcus

adydula said:


> What "spectacular" sonic improvements "exactly" do you get withe replacing the volume pot???
> Inquiring minds want to know?
> 
> Mechanical build ok, sonics hmmmm??
> ...


 

 From my perspective with the $11 Alps upgrade:
  
 Channel balance is perfect, and volume control is much more precise. On the original pot the usable range of volume for me was 8:00-12:00. With the Alps pot that range moves up to 2 or 3:00. I can more easily adjust the range at lower levels. It does't sound like much, but it's very helpful and makes using the amp, and more importantly, listening to music, more enjoyable. 
  
 I can't say it sound betters, but I can say I enjoy the amp and music more because if better control.
  
 And it was only $11.


----------



## Tom-s

For more usable volume range implement FAQ #3.


----------



## adydula

I can agree about precise volume control etc but when hear the result is "spectacular", well I have to ask.
  
 Why because like most I am looking for things that indeed do make spectacular differences but on the sonic side...
  
 It looks like replacing the volume control will not provide me with a "spectacular" improvement in a listening experience.
  
 That said I do appreciate well made "stuff", even a volume potentiometer!!
  
 Alex


----------



## Allanmarcus

adydula said:


> I can agree about precise volume control etc but when hear the result is "spectacular", well I have to ask.
> 
> Why because like most I am looking for things that indeed do make spectacular differences but on the sonic side...
> 
> ...


 

 Once you have a good equipment, and this is just a general rule, you need to spend an order of magnitude of more money to get any significant improvement. To get spectacular improvement, you probably need to spend 2 orders of magnitude more on both equipment and environment. Not always true, but many times true.
  
 I heard a well made crack and a fully decked out one side by side In a blind test, I doubt I could tell the difference. Now, I'm horrible at that, but still, any difference must have been very subtle. 
  
 So why did I install an $11 pot, and upgrade a few wires on my crack? I was able to remove a hum with the wire upgrade (or maybe it just resoldering, who knows, it worked). As for the pot, it was a DIY item that added value and I did all by myself, so 2% to sound improvement, 10% to functionality improvement, and 87% to self-satisfaction (1% due to rounding errors 
  
 If you want "spectacular" improvement on your crack, get a mainline. Even then, "spectacular" might be hard to achieve.


----------



## Elber

I'm sorry I'm Spanish and I hardly speak English, I use translator to write.
  
 The improvement is 100%, the timbre, the detail, the spatiality. Do not explain it better but if they read a little on the net they will realize that the potentiometer Alps is well done (that's why it sells a lot) but it is a potentiometer of 15 euros, it is very basic and with a slightly dark sound .
  
 Another alternative less expensive is tkd 2CP 601   http://www.hificollective.co.uk/potentiometers/tkd-2cp-601s-potentiometer.html
  
 Regards


----------



## Tom-s

And i don't speak Spanish (except on holidays). So this is what i made of it:



> The improvement is 100%, the timbre, the detail, the spatiality. Do not explain it hay better, but if you read a little on the net you will realize that the Blue Alps potentiometer is well done (this is why it sells a lot) but it is a potentiometer of 15 euros, it is very basic and with a veil over the treble.   Another alternative less expensive is tkd 2CP 601 http://www.hificollective.co.uk/potentiometers/tkd-2cp-601s-potentiometer.html


 
  
 With all "upgrades" it's my ears vs yours. YMMV and more of that.
  
 That's why a few pages back the most worthwhile (read: cheap) "upgrades" were listed. 
  
 Keep in mind that a lot of the sound is affected by the tubes. 
  
 The impact of the driver tube is larger with a good quality power tube.
  
 My pairing at this moment (since a few weeks): Tung Sol 5998 with Telefunken 6211.


----------



## JamieMcC

allanmarcus said:


> I heard a well made crack and a fully decked out one side by side In a blind test, I doubt I could tell the difference. Now, I'm horrible at that, but still, any difference must have been very subtle.


 
  
 Really this is a surprise as many find the difference between a hot rodded Crack and a stock Crack easily audible but there are many variables I guess in parts cans sources etc.
  
 I have owned both at the same time by the way.


----------



## adydula

Well its a good thing that people are at least thinking of this topic in terms of "reality"....
  
 Your super hot rodded crack looks kool, and must sound great....but IMO most likely due to the good basic design "Doc" has
 developed...and not as much with all the neat looking "oompa lumpa" parts...
  
 A fool and his money are soon parted, but I have parted with alot as well!!
  
 In the last year I have built and tested side by side 6 head amps and hoping the next one would be "spectacular" ......for a few days it seems to be..and
 then its just another amp....on for the next one...
  
 IMO a stock generic plain jane Crack with or without speedball sounds very nice, works well with the Beyers...and now after years of mucking around
 my humble opinion is it is indeed my "spectacular" baseline.
  
 Alex
 "snowing in NC!"


----------



## JamieMcC

The Oompa Lumpa parts are of course the icing on the cake  
	

	
	
		
		

		
			




  
 However you dont need to spend large to give the performance a boost an inexpensive mod like adding a $10 choke to the power supply will substantially reduce the power supply ripple and lower the Cracks noise floor resulting in a blacker background and giving an increase in resolution this effect is easily audible. Compared to spending $xxx on an after market cable for your cans which will never get close to giving the same reults its a stonking sonic upgrade that costs peanuts.


----------



## adydula

Hey Jamie!
  
 Hope things in the Isle of Wright are okie dokie!!
  
 Has anyone measured this substantial reduction of power supply ripple? If you know please publish or is there a post somewhere that has this data?
  
 I would like to equate this reduction to what this "increase" in resolution equates to?
  
 Alex
  
 (yes i am an anal analytical guy..)


----------



## Tom-s

Search the Bottlehead forum for Choking the Crack. There's a thread where PB explained the benefits of a choke based on a calculator like PSUD2 etc. 
 http://www.duncanamps.com/psud2/
  
 All i remmember is that significant noise floor reduction is the result using a choke in Crack.


----------



## Krit

jamiemcc said:


> Really this is a surprise as many find the difference between a hot rodded Crack and a stock Crack easily audible but there are many variables I guess in parts cans sources etc.
> 
> I have owned both at the same time by the way.


 
  
 You are missing a creed diode mod!


----------



## JamieMcC

From  http://bottlehead.com/smf/index.php?topic=1632.msg74051#msg74051
  
 A simulation of the PSU using Duncan Amps shows stock the Cracks ripple is around 1.5068m
  
 With the C7X choke and keeping the stock capacitors this is reduced to 66.546u
   
  
Some comments here from Paul "PB" Birkeland the Cracks designer on adding chokes to the power supply


  
 http://bottlehead.com/smf/index.php?topic=3498.msg30955#msg30955


----------



## JamieMcC

krit said:


> You are missing a creed diode mod!


 
  
 Its a old pic there have been 6 or 7 Cracks since


----------



## adydula

Do you honestly think that going from 1.5068mv p-p ac? to approx 66uv p-p ac will make a spectacular difference?
  
 Alex
  
 Note: From BH Forum as well...
  
*"I have to order some things from Mouser and Angela Instruments for my Stereomour kit before I move to the wiring stage, so I'm still debating whether I should pick up the Triad choke while I'm at it and replace the first PS resistor in the Crack. Problem is, I don't see how this is going to be worth it - the amp is now absolutely dead silent with the 6CG7, shielded heater wiring, grounded center shield (pin 9), upgraded, non-metallic pot (Alps), and this is even with the pot wide open. It's so quiet that I have to look over at it to know if it is on. Plus, I have the Speedball boards, which no doubt contribute to the quiet, effortless sound. So, what would the choke really accomplish at this point?"*


----------



## JamieMcC

adydula said:


> Do you honestly think that going from 1.5068mv p-p ac? to approx 66uv p-p ac will make a spectacular difference?


 
  
 I didnt say it made a spectacular difference I said its "easily audible". Why not just try it yourself and see they are only $12.08 on Mouser. By the way I also thought my Speedballed Crack was dead silent and had a pitch black background but I was wrong adding the choke improved it!
  
  
 http://www.mouser.co.uk/ProductDetail/Triad-Magnetics/C-7X/?qs=%2fPiZ59IM4y3T0O8Zu9aP3g==


----------



## Tom-s

My experience with the PS mods in chronological order;
  
 1. Cree diode rectifier vs stock: easily audible effect
 2. 2x chokes vs resistors: audible effect
 3. 100uf Film cap/bypass, last in PS, or PIO cap vs stock: maybe? 
 4. 740uf caps in position 1 and 2 vs stock: probably imagination.
  
 My ears vs your ears, difference in other equipment and YMMV etc etc etc
 All in all i like the sound of my Crack.


----------



## adydula

Ok Jamie!!
  
 I am up to soldering in two wires to replace a resistor!! Ha!!
  
 You want me to replace the first resistor in the chain or both???
  
 .......and if I dont hear any difference I am going to tell you.......
  
 I will get hold of an Oscilloscope and measure the AC ripple before and after...
  
 This thing is indeed relatively low cost, probably will cost as much for shipping to me!
  
 Stay Tuned!
 Alex


----------



## JamieMcC

adydula said:


> Ok Jamie!!
> 
> I am up to soldering in two wires to replace a resistor!! Ha!!


 

 Plenty of info here on the mod with input from the Cracks designer.
 http://bottlehead.com/smf/index.php?topic=6030.0
  
  


adydula said:


> .......and if I dont hear any difference I am going to tell you.......


 
  
 Not sure of any modofications for cloth ears 
	

	
	
		
		

		
		
	


	




  Have fun with it anyhow.


----------



## Doc B.

adydula said:


> Do you honestly think that going from 1.5068mv p-p ac? to approx 66uv p-p ac will make a spectacular difference?
> 
> Alex


 
 A few thoughts -
  
 Firstly, that seems to be a reference to numbers generated in PSUD. It's nice modeling software, but it's only as accurate as the number of factors you guessed accurately in the model. 
  
 Secondly most of you guys will never see 66uV of hum on a scope due to EMI in your environment. PB has to shut down his entire house to get those kinds of readings in his lab. We can't even begin to get there in our lab in an industrial park. If these numbers are accurately modeled it will be difficult to reproduce them.
  
 Thirdly, while the relative proportion of the numbers has merit, the actual magnitude of the numbers is useless unless you tell me what the output load is. Ultimately you will also need to know the sensitivity of the cans to say whether this will have much effect. More sensitive, more effect.
  
 Fourthly, has anyone considered that there might be other effects from adding the choke that could alter the sound in a way we don't like? Almost nothing in the audio mods world is a free lunch, except the free lunch at a Bottlehead meet.
  
 All that said, it's not necessarily a difference in hum or background blackness you will hear when you get the noise floor down that low. When going from very low levels to ultra low levels you typically hear more space between notes and a more relaxed presentation.
  
 Don't get me wrong. I am 110% behind getting a scope and seeing what is really going on. But you need to approach the process with no expectations in order to get an objective measurement.


----------



## adydula

Hey Doc....good thoughts....
  
 I am a pretty objective guy but am always open to "new" stuff and "new" ideas, but adding a choke in the Bottlehead IMO will not add any real world audible differences even if a choke is $12 + shipping!! lol.
  
 I wonder how many people have pondered your statement:
  
 "has anyone considered that there might be other effects from adding the choke that could alter the sound in a way we don't like? Almost nothing in the audio mods world is a free lunch, except the free lunch at a Bottlehead meet."
  
 You may want to expound on that statement for the masses....
  
 Alex
 :>)
  
 PS: If you ever hold a Bottlehead meet in Raleigh, NC I will buy you lunch!!


----------



## JamieMcC

adydula said:


> I am a pretty objective guy but am always open to "new" stuff and "new" ideas, but adding a choke in the Bottlehead IMO will not add any real world audible differences even if a choke is $12 + shipping!! lol.


 
  
 As I'm one of the many who have *actually* done this mod and liked the results I think I will stick to with my own opinion on this one if you dont mind  
	

	
	
		
		

		
		
	


	



  
 Any how enough of chokes how are you liking the Crack compared to the O2?


----------



## adydula

Jamie,
  
 I have approx 5 - O2's....
  
 One totally stock....
 One with OP1688's.
 One with AGDR Booster Board (827's) (has zero ohm output impedance).
 One with an inverting ampflifier stages...
 One is a super upgrade that makes the O2 an ODA of sorts.
  
 So back to the question of the O2 vs the Crack.
  
 Well, both are good amps that do a good job with most of my headphones. Of course the OTL crack really only works well with the higher impedance cans. 
 I have gone thru a lot of cans...Audeze, Senns, Audio Technica, Grados, Beyers, AKG etc...
  
 I have settled in on Beyer T90's and T1's 2nd gen. I dont like things that get in the way of what on the recording....I like clear, transparent, good soundstage etc.
  
 The amp has little to do with most of this IMO, but the two amps sound very different to me.
  
 I had the O2's for a few years but always wanted to hear what a good tube amp would sound like...and I grew up with tubes...lots of them!!
  
 So i built one, added Speedball and now I can say the O2 is clearer to me, but the Crack is softer to me...pleasing but not as accurate to me.
  
 I have gone thru a bunch of tubes, most of which sound the same to these "cloth" ears of mine!
  
 I had had several other amps, and sold most of them, but kept the O2's and the Crack...so that should tell you something.
  
 I use the crack more than the O2's...why because it sounds "better" to me most of the time...even though the O2 might be clearer or more crisp!
  
 There is no way I would spend hundreds of bucks on NOS tubes for imaginary gains....the RCA 6AS7G's and 12AU7's are just fine to me.
  
 I have a strong desire to build  mainline...only to see and compare for myself the differences...and then I have the right to diatribe whether its worth it!! LOL!!
  
 I have spent lots of time blind testing and A/B ing the O2 against other amps as well...
  
 Alex


----------



## Kozic

Hey guys I just got done putting one together and going over the Resistances all are good but the center pin (the last one 
	

	
	
		
		

		
		
	


	




). I'm getting 00.0, all the joints look and feel good both led banded ends are going to the center and the wire to the top inner volume pot looks good. any thoughts I posted over on bottlehead too.
 Thanks 
  
 Never mind I got it it was the RCA jack not the tube center pin.


----------



## buke9

I bought a pre assembled Crack and have a Speedball on order and the PDF says I need to do resistance checks but have no idea how to do that as I'm not the original builder. Is there somewhere I can get this ? I've checked out the website but nowhere to download it. Can someone send it to me or is this not allowed?


----------



## Allanmarcus

buke9 said:


> I bought a pre assembled Crack and have a Speedball on order and the PDF says I need to do resistance checks but have no idea how to do that as I'm not the original builder. Is there somewhere I can get this ? I've checked out the website but nowhere to download it. Can someone send it to me or is this not allowed?




You'll need a multimeter and some basic understanding of electricity. YouTube is a great place to study up

Basically you set you multimeter to ohm and touch the sensors to two points and read the results.


----------



## JamieMcC

buke9 said:


> I bought a pre assembled Crack and have a Speedball on order and the PDF says I need to do resistance checks but have no idea how to do that as I'm not the original builder. Is there somewhere I can get this ? I've checked out the website but nowhere to download it. Can someone send it to me or is this not allowed?


 
  
 Contact Bottlehead direct with your order reference I am sure they will be able to quickly help.


----------



## buke9

allanmarcus said:


> You'll need a multimeter and some basic understanding of electricity. YouTube is a great place to study up
> 
> Basically you set you multimeter to ohm and touch the sensors to two points and read the results.


I know enough about electronics was a Interior Communications Technician in the Navy many moons ago I just don't know where the points are on the amp that needs testing or the values I'm looking for.


----------



## Allanmarcus

buke9 said:


> allanmarcus said:
> 
> 
> > You'll need a multimeter and some basic understanding of electricity. YouTube is a great place to study up
> ...




That's all in the manual. See if you can get a copy from BH, or PM me.


----------



## buke9

jamiemcc said:


> Contact Bottlehead direct with your order reference I am sure they will be able to quickly help.


I got the PDF for the Speedball but it say to check resistance on the amp that is what I don't have.


----------



## Allanmarcus

buke9 said:


> jamiemcc said:
> 
> 
> > Contact Bottlehead direct with your order reference I am sure they will be able to quickly help.
> ...


 

 Right. All that is in the Crack manual.


----------



## adydula

You can post a note on the Bottlehead forum.....or call them or send them an email..
  
 Alex


----------



## buke9

Thanks all but a friendly Head-Fi'er has emailed me a copy of the manual so all is good in the world again.


----------



## Timoteo80

Thought id post of pic of my recent Crack build. I have the Speedball upgrade on the way. REALLY enjoying the stock Crack it's a beautiful amp the makes my HD600s sound amazing  HIGHLY recommended!!


----------



## buke9

timoteo80 said:


> Thought id post of pic of my recent Crack build. I have the Speedball upgrade on the way. REALLY enjoying the stock Crack it's a beautiful amp the makes my HD600s sound amazing  HIGHLY recommended!!


Sweet looking job on the stain. Get ready to wait on the Speedball I have it on order for a month now and still says processing order.


----------



## Timoteo80

buke9 said:


> Sweet looking job on the stain. Get ready to wait on the Speedball I have it on order for a month now and still says processing order.




Yeah when I originally ordered my Crack it took about a month to receive. Bottlehead does state on their site that a 1 month wait is average tho. But waiting more than a month is a bummer. I emailed them with some questions & got prompt responses so I recommend you contact them & ask how much longer you should expect to wait.

As far as me receiving the Speedball upgrade, I'm totally fine waiting because I am not going to install it right away. I am really enjoying the stock Crack & ordered it so I could have it on hand for the day the "upgrade bug bites"! We all know that day is inevitable haha.

Thank you for the compliment BTW. I routed the 4 long lengths of the wood enclosure to match the look of the Lenco TT plinth I built. Used Ebony stain & 3 coats of TripleThick polyurethane to get the high gloss to match the epoxy coat on the TT. You can kinda see it in the background.


----------



## Timoteo80

Ok so the stock 12au7 on my Crack has gotten VERY microphonic. I can barely touch the volume knob with out hearing it in my cans even with the volume at 0. If I tap the amp or the tube itself very lightly with the back of my fingernail it "tings" & will create a "hum" for a solid minute+. To me it sounds like the tap creates a vibration inside the tube which then resonates for a bit. If I turn the power switch off then back on it seems to go away. It is very easily created even when trying to be as gentle with everything as possible, definately not normal.

Any advice welcome!!

Also, I'd like to replace/upgrade the stock 12au7. I cannot afford but maybe $40. Recommendations on tubes are very welcome please.

Thx guys!!


----------



## Tom-s

Use this and search the tube rolling with Crack thread on the BH forum for recommendations. 
 A lot depends on what type of sound you are looking for.


----------



## hdtv00

timoteo80 said:


> Ok so the stock 12au7 on my Crack has gotten VERY microphonic. I can barely touch the volume knob with out hearing it in my cans even with the volume at 0. If I tap the amp or the tube itself very lightly with the back of my fingernail it "tings" & will create a "hum" for a solid minute+. To me it sounds like the tap creates a vibration inside the tube which then resonates for a bit. If I turn the power switch off then back on it seems to go away. It is very easily created even when trying to be as gentle with everything as possible, definately not normal.
> 
> Any advice welcome!!
> 
> ...


 
 http://www.ebay.com/itm/TESTS-NOS-MULLARD-UK-12AU7-ECC82-PRE-AMP-AUDIO-TUBE-TESTS-STRONG-A84-/112213295787?hash=item1a206f02ab:g:-1QAAOSwj85YNLw1
  
 http://www.ebay.com/itm/1-NOS-Amperex-Holland-12AU7A-Tube-/192081823835?hash=item2cb8f8085b:g:dcsAAOSwjDZYf7HQ


----------



## dede4metal

doc b. said:


> Nope. ANY tube circuit can be susceptible to RFI. The Speedball, by virtue of its high impedance, actually improves the situation by isolating the circuit from any RFI coming in through the power supply.


 
 OK I have moved it into another room and now it is fine. Strange though since it did have the speedball installed.


----------



## Timoteo80

Received a few NOS tubes to roll. Barely had time to try them out tho. Excited to roll them once the Speedball arrives & gets installed. I've read that the difference in tubes is greater heard AFTER the SB upgrade is done to the Crack. Besides the stock 6080 I have 2 6as7g tubes to try (RCA & Sylvania) & 4 NOS 12au7s (RCA clear top, Mullard, GE & a long black plate with no print) Fun stuff!!


----------



## chuckwheat

timoteo80 said:


> Besides the stock 6080 I have 2 6as7g tubes to try (RCA & Sylvania)


 
 ooh. Please let me know if you prefer them over the stock. I'm looking to change out the stock tube.


----------



## Timoteo80

chuckwheat said:


> ooh. Please let me know if you prefer them over the stock. I'm looking to change out the stock tube.




Works been busy & I haven't had much time with my Crack. I have listened for about 1hr with the RCA 6as7g. However it seemed a bit more harsh so far. I swapped in the stock 6080 & it was smoother. However to be fair, I did notice that I can hear something loose inside the RCA 6as7g if lightly shook. So it might not be nos as the seller suggested & may be running out of juice. The other 6as7g got delayed in the mail & I haven't received it yet. I'll be doing more listening before making any claims tho.


----------



## LikeABell

Hello everyone, finished my crack recently. Loving it!


----------



## DavidA

@LikeABell, very nice workmanship, love the corner/feet braces


----------



## LikeABell

davida said:


> @LikeABell, very nice workmanship, love the corner/feet braces


 
 Thanks! My first time doing DIY. Was so much fun.


----------



## DavidA

likeabell said:


> Thanks! My first time doing DIY. Was so much fun.


 
 I can see a HD-700 and M50x? on your headphone stand, are those the only 2 headphones that you use with the BH Crack?


----------



## LikeABell

davida said:


> I can see a HD-700 and M50x? on your headphone stand, are those the only 2 headphones that you use with the BH Crack?


 
 HD700 and M40x. I have a pair of HD558s too. But I mainly use the HD700s. HD558s sound surprisingly good too, LOTS of bass.


----------



## Timoteo80

Hmm besides my HD600s I have the HD558 & the M50x as well. I hadn't even thought to try either of the other two pairs on my Crack...I'll have to give it a try!!! 

Side Note: I just received the Speedball upgrade in the mail this week. Finally after over 6 weeks. I wasn't I. A rush so it didn't bother me. I have REALLY been enjoying the Crack stock & wanted to get akin to its sound before the SB upgrade.


----------



## adydula

Just got a new RCA 6AS7G from Tubedepot...first one was humming a lot, AC heater noise, they replaced it with no quibblng and the second one is excellent, quiet, works very well......Even the RCA's are getting pricey!! $30 + shipping.
  
 My crack has speedball and it does make a difference...
  
 Headphones, Beyer T90 and T1 2G...the crack works with these cans as best as I have heard...
  
 Alex


----------



## SP Wild

Noob toob here. 'they' say the Tung Sol 5998 is the bee knees of these tubes. 

They seem to be VERY expensive. I am thinking of getting a matched pair, I can use in my WA22 and SB Crack. 

Is there a new contender or are these still the tubes to get, maybe even someone can say... Don't bother this is Audio nervosa. 

???


----------



## buke9

sp wild said:


> Noob toob here. 'they' say the Tung Sol 5998 is the bee knees of these tubes.
> 
> They seem to be VERY expensive. I am thinking of getting a matched pair, I can use in my WA22 and SB Crack.
> 
> ...


5998 in the Crack is awesome. Yes they are getting expensive .


----------



## lyncks

Hey everyone
  
 anyone using this with the k7xx? good match?
  
 Cheers


----------



## i luvmusic 2

I did with Q7XX and i don't like it the Q sounds like lacking in bass and a bit bright to my ears.


----------



## DavidA

lyncks said:


> Hey everyone
> 
> anyone using this with the k7xx? good match?
> 
> Cheers


 
 Just tried my K7XX with BH Crack, not a good pairing, I think the output impedance of the Crack is too high for them, K7XX pairs much better with Lyr2 or Ember.


----------



## lyncks

Thanks for the quick replies!
  
 The headphones are on their way and have no amp yet  so annoying.
  
 Cheers


----------



## DavidA

lyncks said:


> Thanks for the quick replies!
> 
> The headphones are on their way and have no amp yet  so annoying.
> 
> Cheers


 
 While I love my BH Crack its really only for high impedance headphones like the HD-600/650/700/800, T1, and the other DT 250/600 ohm versions.

 ​The amps offered by Garage 1217 like the Polaris (SS for $250) or Solstice (hybrid tube for $250) are quite good an flexible enough to use with a much wider range of headphones than the BH Crack.


----------



## lyncks

Those look pretty nice I must say.
  
 need to read more about them.
  
 Cheer man


----------



## ohcrapgorillas

Okay, so I'm neck deep in this thing and I absolutely love this amp.
  
 My power tubes are Tung-Sol 5998, GE 6AS7GA, Sylvania Winged C 6H13C, Chatham 6080, and stock 6080. I have recently added a Shuguang 6H13C to that collection and so far, I am really impressed with what I got for $10! The Tung-Sol 5998 is obviously the king, but I think the GE 6AS7GA is a solid runner up.
  
 My 12AU7 tubes are...just kidding, who cares about these little things? I got a 6SN7 adapter from Garage1217 and have barely given my 12AU7 tubes a second listen. I have Raytheon, Sylvania, and Russian vintage surplus 6SN7. They are _vastly_ superior to the 12AU7 tubes in every way. I have been seriously impressed with the "old russian" tube: it is a very no-nonsense, solid stateish sounding tube with great resolution and dynamics. It cost me $5. The Raytheon VT-231 is the best I've heard in the Crack yet, though.
  
 So far the mods I've added:
  

Speedball, duh
cheap chinese 21-step attenuator, 100Kohm. the stock potentiometer is really bad and replacing it with anything, even a blue velvet, is a good idea. unfortunately 21 is not enough steps for my tastes, so I'm going to be replacing this with a 3-way gain switch and a 50Kohm 21-step attenuator. the people at bottlehead helped with the not-obvious-at-all wiring schematic on this so as to keep the load at ~100Kohm ish. 
Dayton film capacitors in place of the output capacitors. this makes such a difference in clarity that I consider any Crack without film cap outputs to be an incomplete unit
  
 I also did some mods to the power supply all at once:
  

added a 2.2uF film cap bypass to the middle capacitor in the power supply
adding a Triad C7-X inductor to replace the first resistor in the power supply, which in turn allows me to....
replace the last capacitor in the power supply with a Panasonic 100uF film cap.
  
 while I can't comment on how each individual mod in the power supply affects the sound quality, I can say that I was absolutely blown away by the resolution I was getting. I did not know that my headphones (HD650) were capable of reproducing such fine textures and details. I was hearing lots of things I had not heard before and with a surprising amount of extra detail. I have to say that modding the Crack is a gift that keeps on giving. The gains are typically surprising. I was really genuinely stunned by the gains that came from modding the power supply, but then again I live in an old building with ****ty wiring/power so ymmv.
  
 I think I am running out of mods here. I have seen some people using chokes at the start of the power supply, that looked really simple so might give that a go sometime. Also, recently a friend of mine gifted me three 1uF paper-in-oil capacitors so that I could bypass the output caps and the last power supply cap to see if that makes a difference. He has done it to his Crack and thought he heard a slight improvement but was willing to admit that it might well be placebo.
  
 After this, I swear I am done. Like there will be literally no more room left in the damn case. I would have to re-home my Crack entirely to add anything else.


----------



## Maxhawk

lyncks said:


> Hey everyone
> 
> anyone using this with the k7xx? good match?
> 
> Cheers


 
  
 If you use a transformer on the output you can lower the output impedance at the expense of gain. This works with my 25Ω Fostex TH-X00 and the 62Ω AKG K7XX. I used two 10KΩ to 150Ω (8.2:1) transformers and it restores the tight bass that I get with my Sennheiser HD800. I installed them into an enclosure with 1/4" jacks that lets me install it inline when I use low impedance cans.


----------



## Allanmarcus

ohcrapgorillas said:


> Okay, so I'm neck deep in this thing and I absolutely love this amp.
> 
> :
> 
> ...




Can you please post part numbers, pics and instructions?


----------



## ohcrapgorillas

allanmarcus said:


> Can you please post part numbers, pics and instructions?


 
 Part number: DMPC-100
  
 Instructions:
  
 1. Remove the old blue 100 uF 160V output coupling capacitors from your Crack. Cut one open and offer it as a sacrifice to Jude or Tyll or whoever your guardian audiophile is, in the hopes of a successful mod and great sound quality to you and your lineage for a thousand years. Then throw them in the trash where they belong.
  
 2. You will need to mount the new capacitors somehow. They are large, about the size of a small can of soup. I used some small strange loops that I found at home depot--no idea what they're called or their original purpose--which could be drilled into the chassis. I then wrapped a zip tie around that to tie the new capacitor to it. Be creative, there are lots of solutions out there to this problem. In general, double-sided tape is frowned upon as it degrades with heat. 
  
 3. Solder the capacitor wires onto the terminals where the old caps used to be. Film caps are bipolar, so there's no need to worry about which wire goes where.
  
 These capacitors I believe do burn in a little bit, so may sound slightly harsh at first, but after they settle in you will notice a BIG improvement in clarity.
  
 Crappy pic of my Crack below. Note that the large black rectangular feature in the power supply, the 100 uF panasonic film cap, is not secured to the chassis and so sits on the table underneath the amp. Really gotta do something about that but it's a REEALLY tight fit. The little red thing to the left and behind the inductor (the large feature blocking the view of the power transformer) is a WiMA 2.2 uF film cap bypass for the middle cap in the power supply. The large film cap nearest to the attenuator is pushed back so as to make hypothetical room for a gain switch (which I have, I just have yet to put in).


----------



## Allanmarcus

Many thanks @ohcrapgorillas !
  
 I found this page <http://diy.koenigs.dk/2014/02/26/hot-rodding-with-film-caps/> which has a more step by step guide. I'm sure there are more.
  
 Many thanks for the part number and helpful instructions.


----------



## vintinfinity

ohcrapgorillas said:


> Okay, so I'm neck deep in this thing and I absolutely love this amp.
> 
> My power tubes are Tung-Sol 5998, GE 6AS7GA, Sylvania Winged C 6H13C, Chatham 6080, and stock 6080. I have recently added a Shuguang 6H13C to that collection and so far, I am really impressed with what I got for $10! The Tung-Sol 5998 is obviously the king, but I think the GE 6AS7GA is a solid runner up.
> 
> ...


 
 Is it ok to use the 2.2uf power supply bypass cap without the speedball?
  
 I got my Crack already built in need of repair with a speedball that the previous builder couldn't get to work. We got the amp sorted and I installed the Speedball but it hurt my ears. Not sure if it is because the builder damaged the LEDs that come with the kit then used a cheaper replacement. They are visibly different. I also initially had a miswire of the high voltage into the speedball board accidentally so I don't know if that caused the peaky feeling in my ears if I fried something. Or possibly from the failed attempts by the first builder, additionally. Voltages all tested ok, but a bit above the given values in the manual for voltage.
  
 Is it worth also doing the 2.2 cap in that case if I am going to upgrade to the big caps for output?


----------



## ohcrapgorillas

vintinfinity said:


> Is it ok to use the 2.2uf power supply bypass cap without the speedball?
> 
> I got my Crack already built in need of repair with a speedball that the previous builder couldn't get to work. We got the amp sorted and I installed the Speedball but it hurt my ears. Not sure if it is because the builder damaged the LEDs that come with the kit then used a cheaper replacement. They are visibly different. I also initially had a miswire of the high voltage into the speedball board accidentally so I don't know if that caused the peaky feeling in my ears if I fried something. Or possibly from the failed attempts by the first builder, additionally. Voltages all tested ok, but a bit above the given values in the manual for voltage.
> 
> Is it worth also doing the 2.2 cap in that case if I am going to upgrade to the big caps for output?


 
  
 First of all, you can get the original LEDs from Bottlehead for really cheap. It's worth doing that right, because those set the bias on the tubes and having that wrong could be really bad. I would honestly go back and try and get the speedball right. I think it's definitely worthwhile, and the people on the Bottlehead forums are incredibly helpful. Like, really really great and responsive support. They even designed a 3-way gain switch for me that keeps the load around 100Kohm!
  
 As for the 2.2 uF bypass, this can go in at any point regardless of anything else like output caps or speedball. Bypassing capacitors is a pretty simple, common practice in audiophile engineering: you take a mediocre capacitor, usually aluminum, and run a much better capacitor with 1% of the capacitance in series with it. The idea is you get something like a 50/50 split between actual performance, despite the capacitance only being a 1:100 ratio. Pretty good deal. Best practice would put this in series with the last capacitor in the power supply, rather than in the middle like I've done (since I've completely replaced my last power cap). You could even get three 2.2 uF caps and bypass all three power supply capacitors! Those are easy to mount to the chassis with a little bit of superglue, as long as you let it set for the proper amount of time. 
  
 As for the link above ^, I have no idea why this guy is bypassing film capacitors with other film capacitors? I'm no expert, but that seems kind of asinine. I am excited to try bypassing my output film caps with some 1uF paper-in-oil caps that a friend of mine gave me, but I'm not expecting any miracles.


----------



## Timoteo80

QUESTION:
If I install a 12au7 to 6sn7 adaptor on my stock Crack do I need to do any rewiring? Or is it just plug & play?


----------



## ohcrapgorillas

timoteo80 said:


> QUESTION:
> If I install a 12au7 to 6sn7 adaptor on my stock Crack do I need to do any rewiring? Or is it just plug & play?


 
  
 Plug and play, no rewiring or bias adjustment required
  
 I have heard that not just any 6SN7 adapter will work. I don't quite recall exactly what the issue was, something about how the 12AU7 has 9 pins and the 6SN7 only has eight (same socket style as the 6080), and what was being done with the ninth pin. Like it had to be grounded or something? Don't quote me on that. The Bottlehead people grudgingly recommend the Garage1217 adapter, but there are some REALLY cheap adapters from China that might work.


----------



## Timoteo80

ohcrapgorillas said:


> Plug and play, no rewiring or bias adjustment required
> 
> I have heard that not just any 6SN7 adapter will work. I don't quite recall exactly what the issue was, something about how the 12AU7 has 9 pins and the 6SN7 only has eight (same socket style as the 6080), and what was being done with the ninth pin. Like it had to be grounded or something? Don't quote me on that. The Bottlehead people grudgingly recommend the Garage1217 adapter, but there are some REALLY cheap adapters from China that might work.




Thank you for the quick reply! 
I was checking out the Garage1217 adapter at $25 which seemed a little high. I'll look into other options, if anyone else knows of a quality alternative for less I'm all ears! 
Thx again!!


----------



## buke9

Just hooked up the Crack after letting a fellow Head-Fi'er test it out and something is wrong. It would only play out of the left side. If I pulled the plug up a little then both sides would play but the sound is a bit off. I tried different headphones and cables both ends and input tubes also have not tried a different power tube yet but something is not right. Any ideas?


----------



## vintinfinity

ohcrapgorillas said:


> First of all, you can get the original LEDs from Bottlehead for really cheap. It's worth doing that right, because those set the bias on the tubes and having that wrong could be really bad. I would honestly go back and try and get the speedball right. I think it's definitely worthwhile, and the people on the Bottlehead forums are incredibly helpful. Like, really really great and responsive support. They even designed a 3-way gain switch for me that keeps the load around 100Kohm!
> 
> As for the 2.2 uF bypass, this can go in at any point regardless of anything else like output caps or speedball. Bypassing capacitors is a pretty simple, common practice in audiophile engineering: you take a mediocre capacitor, usually aluminum, and run a much better capacitor with 1% of the capacitance in series with it. The idea is you get something like a 50/50 split between actual performance, despite the capacitance only being a 1:100 ratio. Pretty good deal. Best practice would put this in series with the last capacitor in the power supply, rather than in the middle like I've done (since I've completely replaced my last power cap). You could even get three 2.2 uF caps and bypass all three power supply capacitors! Those are easy to mount to the chassis with a little bit of superglue, as long as you let it set for the proper amount of time.
> 
> As for the link above ^, I have no idea why this guy is bypassing film capacitors with other film capacitors? I'm no expert, but that seems kind of asinine. I am excited to try bypassing my output film caps with some 1uF paper-in-oil caps that a friend of mine gave me, but I'm not expecting any miracles.




I may have to revisit the speedball. I noticed the wrong leds in there after the fact. 

I meant to ask if it is really worth doing the 2.2 psu bypass cap if I were to use the Dayton film caps on the output, I didn't want to fiddle with tiny output bypass caps as on the link.


----------



## ohcrapgorillas

vintinfinity said:


> I may have to revisit the speedball. I noticed the wrong leds in there after the fact.
> 
> I meant to ask if it is really worth doing the 2.2 psu bypass cap if I were to use the Dayton film caps on the output, I didn't want to fiddle with tiny output bypass caps as on the link.


 
  
 An output cap bypass would ideally be 1 uF, not 2.2 uF, since the ideal value is 1% and the output caps here are 100uF (power supply is 220 uF so those bypasses are 2.2uF). And no, I don't think that bypassing the Dayton film caps with another type of film cap would be worthwhile. You'd get a lot more out of bypassing power supply capacitors than you would bypassing output film capacitors with more film caps.
  
 If you wanted to use something else fancy and exotic like silver mica, that might make a difference. I am gonna try and use paper-in-oil bypasses, which is a totally different (and supposedly superior) type of capacitor to the metallized polypropylene film ones, and I'm only planning on doing that because I have them and it's easy to zip-tie them to the Daytons that are already in there.


----------



## LikeABell

buke9 said:


> Just hooked up the Crack after letting a fellow Head-Fi'er test it out and something is wrong. It would only play out of the left side. If I pulled the plug up a little then both sides would play but the sound is a bit off. I tried different headphones and cables both ends and input tubes also have not tried a different power tube yet but something is not right. Any ideas?


 
 Something is wrong. You get a mono signal when you lift the jack up slightly.
  
 Are both LEDs lighting up? You could try reflowing all solder joints. I would post on the BH forum.


----------



## buke9

likeabell said:


> Something is wrong. You get a mono signal when you lift the jack up slightly.
> 
> Are both LEDs lighting up? You could try reflowing all solder joints. I would post on the BH forum.


Not for sure if it is mono or not just happened and don't have the time right now to diagnose it just was wondering if it was something simple I overlooked. I didn't build the amp myself as it was a great deal and was about ready to start the Speedball upgrade and have to figure this out first. Just tried different power tube same result so not something simple. Not the source as it is fine on another amp and checked the other output also. I was in listening mode and have had a couple of adult beverages so this will have to wait to go any further. Thanks for your response will try something tomorrow.


----------



## LikeABell

buke9 said:


> Not for sure if it is mono or not just happened and don't have the time right now to diagnose it just was wondering if it was something simple I overlooked. I didn't build the amp myself as it was a great deal and was about ready to start the Speedball upgrade and have to figure this out first. Just tried different power tube same result so not something simple. Not the source as it is fine on another amp and checked the other output also. I was in listening mode and have had a couple of adult beverages so this will have to wait to go any further. Thanks for your response will try something tomorrow.


 
 No problem.
 Also, I would strongly discourage you from connecting your good headphones to the crack until the issue is resolved.


----------



## buke9

likeabell said:


> No problem.
> Also, I would strongly discourage you from connecting your good headphones to the crack until the issue is resolved.


Agreed .


----------



## heliosphann

I'm kinda having a similar problem. When I first power on my BHC w/speedball and plug a headphone in, I get sound in the left channel only and a very nasty pop in the right channel. I think it has something to do with the input tube seating, because if I move the tube around it'll eventually play in both channels. I did not build it, so I'm pretty ignorant on what it could be or how to fix it.


----------



## adydula

I have had nasty pops at random and then when slightly moving the 12AU7A smaller input tube in its socket gently.
  
 Many people pop tubes in and out and the two small red leds soldered in the socket can become "loose" or the leads of this small device can come loose due to their initial installation (no "slack" in the leads to tube socket pins), This installation with no play in the led leads move over time with tube change-outs, they may crack, fracture or come unsoldered.
  
 I had this several times, fixed by re-soldering for a short while, then it comes back, sometimes weeks later...so
  
 Ordered a new set of leds, removed old ones, re-installed new one with "bends" in the legs to help take up any movement of the socket pins when changing out tubes. Also when changing out tubes I am very careful not to rock the tube excessively.
  
 For several months now its been fine....that really annoying and scar "pop" is alarming...
  
 Another way to resolve this is to make up a small circuit board and hot glue it to the top panel near the tube socket and mount the leds on the board so no mechanical movement is allowed on the leds and just wire to the tube pins with flexible wires...
  
 Alex


----------



## vintinfinity

ohcrapgorillas said:


> An output cap bypass would ideally be 1 uF, not 2.2 uF, since the ideal value is 1% and the output caps here are 100uF (power supply is 220 uF so those bypasses are 2.2uF). And no, I don't think that bypassing the Dayton film caps with another type of film cap would be worthwhile. You'd get a lot more out of bypassing power supply capacitors than you would bypassing output film capacitors with more film caps.
> 
> If you wanted to use something else fancy and exotic like silver mica, that might make a difference. I am gonna try and use paper-in-oil bypasses, which is a totally different (and supposedly superior) type of capacitor to the metallized polypropylene film ones, and I'm only planning on doing that because I have them and it's easy to zip-tie them to the Daytons that are already in there.


 
  I don't want to bypass the Dayton output caps. I'm trying to ask how much of a difference there would be only doing the big output Dayton caps with no bypass on them and no power supply bypass, compared to Dayton output caps by themselves with a power supply bypass. For instance, as you said (using a 2.2uf WIMA) on the last power supply cap (I want to keep it simple and to one bypass if that is effective) 
  
 I'm inclined to just do the Dayton output cap upgrade with no power supply bypass since I'm not sure how everything is supposed to be arranged with the psu cap bypass. Unless someone can point out how to wire the last power supply cap bypass.


----------



## ScottFW

Quote:


heliosphann said:


> ... a very nasty pop in the right channel....


 
 The nasty pops are probably caused by a loose/intermittent connection. I went through a similar thing 2-3 weeks ago... hissing and pops in just the L channel. I had success with the chopstick method: operate the amp upside down while listening to some music with some headphones that aren't precious to you, and probe every component & solder joint with a wood/plastic (something non-conductive!) chopstick or similar, and you should be able to quickly ID anything that's loose. Don't stop probing when you find one loose part; probe everything in case there's more than one culprit.
  
 In my case it was one of the 2N2907A transistors on a Speedball board... not exactly a part that I'd think would be subjected to movement or stress. The amp had worked perfectly noise-free from initial build through Speedball upgrade and a few mods/tweaks over two years' time before I started getting the hissing and pops. I can't really explain it (heat cycling a handful of times per week combined with the fact that it hangs upside down?) but one of the joints had obviously loosened up over time. Thankfully, an easy fix. So far so good.


----------



## buke9

Only one led lit so that could be the problem. The joint seems good though.


----------



## adydula

If the led isnt lit its an issue....try resoldering it...if that does it, it will come back!
  
 Alex


----------



## LikeABell

adydula said:


> I have had nasty pops at random and then when slightly moving the 12AU7A smaller input tube in its socket gently.
> 
> Many people pop tubes in and out and the two small red leds soldered in the socket can become "loose" or the leads of this small device can come loose due to their initial installation (no "slack" in the leads to tube socket pins), This installation with no play in the led leads move over time with tube change-outs, they may crack, fracture or come unsoldered.
> 
> ...


 
 This. I had done a horrible job with the LEDs. I'd get all sorts of pops, static, hiss. It was very frustrating, to be honest.
 So I finally removed the LED, wicked out all the solder, bent the LED and soldered it firmly. It's all been good after that.


----------



## buke9

Well reflowing didn't work. Think the led died? What next ?


----------



## LikeABell

buke9 said:


> Well reflowing didn't work. Think the led died? What next ?


 
 I would post on the BH forum. You get top class troubleshooting there from the makers themselves.


----------



## adydula

Agree the guys at the BH forum will assist.

Check that the led is in the right direction...and if its ok, then just order new leds from BH.
Replace both of the leds on the input tube and when installing the new ones be careful and bend the
leads carefully so there is some slack and hopefully this will fix this for you.

Over at the BH forum this has been discussed even by "Doc" himself.

The leds are cheap....

Alex

NOTE: Glad this helped out the other person....Be gentle when replacing tubes, solder, leads will fracture making like a cold solder joint and or damaging parts.


----------



## HOLLOWCOW

hello,
 I got the crack + SB with the recent new international transformer (not sure what it is, they announced it on their website)
 my question is, do I have to plug off my headphone every time I shut it down and only plug again when the amp is warmed up a little?
 it is not recommended to just leave them plug in all the time?
  
 thank you.


----------



## JamieMcC

hollowcow said:


> hello,
> I got the crack + SB with the recent new international transformer (not sure what it is, they announced it on their website)
> my question is, do I have to plug off my headphone every time I shut it down and only plug again when the amp is warmed up a little?
> it is not recommended to just leave them plug in all the time?
> ...


 

 Quiet a few just leave their headphones plugged in personaly I never had any issues in doing so for several years with the old transformer. But I would recommend if trying out a new to you valve for the first time to use some old headphones for that first power up just in case you are very unlucky to get a dodgy tube that arcs and pops.


----------



## ohcrapgorillas

vintinfinity said:


> I don't want to bypass the Dayton output caps. I'm trying to ask how much of a difference there would be only doing the big output Dayton caps with no bypass on them and no power supply bypass, compared to Dayton output caps by themselves with a power supply bypass. For instance, as you said (using a 2.2uf WIMA) on the last power supply cap (I want to keep it simple and to one bypass if that is effective)
> 
> I'm inclined to just do the Dayton output cap upgrade with no power supply bypass since I'm not sure how everything is supposed to be arranged with the psu cap bypass. Unless someone can point out how to wire the last power supply cap bypass.


 
  
 The two upgrades you're talking about are in two totally different parts of the circuit and, theoretically speaking, have two different effects. The idea--as I understand it, and I am no EE--is that film capacitors have a much faster response time and are better at noise rejection than electrolytic capacitors.
  
 When you upgrade the output capacitors, you're replacing the thing that is literally right between the tube and headphone jack. Your entire, completed music signal is going through those capacitors and your headphone jack is wired directly to them. Having something "faster" in that spot is an obvious advantage that yields significantly better resolution and a cleaner background.
  
 When you put a bypass on the last capacitor of the power supply, you're not only helping your power supply respond to large demands faster but you're adding better noise rejection. There's typically a little bit of AC ripple that gets passed on to the DC power supply, and a film capacitor bypass does a better job of smoothing out that ripple current than electrolytic capacitors (aka film caps have a higher ripple current rating) so your tubes are getting cleaner, more stable power. That is the general purpose of the speedball upgrade as well as I understand it, and people generally agree that the speedball results in a cleaner sound, especially in the bass. (A film cap bypass is no substitute for speedball, which is much more thorough).
  
 By the way, all you have to do to bypass the last power supply cap is wire the two ends of the 2.2uF film cap to the terminals with the two leads of the last power supply capacitor--literally just run it in parallel series. Solder wires from each end of one cap to an end of the other. Film caps are bipolar so it doesn't matter which wire goes to the + or - on the electrolytic. I think the wima caps are less than $5 from mouser or digikey, they are light and can easily be superglued onto the chassis wherever (the closer the better) for stability. I would also recommend twisting the wires together for noise rejection since they run near the transformer.
  
 I never did the bypass on the last PSU cap, I went straight for replacing it with a film cap and adding the inductor so I can't speak to how much of an upgrade it would be on its own, but I think the results would probably be worthwhile for the $5 experiment.


----------



## ScottFW

ohcrapgorillas said:


> By the way, all you have to do to bypass the last power supply cap is wire the two ends of the 2.2uF film cap to the terminals with the two leads of the last power supply capacitor--literally just run it in *parallel*.


 
 FTFY


----------



## ohcrapgorillas

scottfw said:


> FTFY


 
 Damn, what was I thinking? lol thanks
  
 Also, just ordered some cree diodes for me and another Crack-head friend, very interested to see how these sound. that will be the final upgrade.


----------



## Tom-s

For all those looking for some Crack, it's on SALE! : http://bottlehead.com/?product=crack-otl-headphone-amplifier-kit


----------



## Hofy

tom-s said:


> For all those looking for some Crack, it's on SALE! : http://bottlehead.com/?product=crack-otl-headphone-amplifier-kit


 
 Oh, my aching wallet!


----------



## LikeABell

Oh god! $199 for the basic crack is a STEAL!
 I'm tempted to buy another, build and sell.


----------



## buke9

Almost too good to pass up.


----------



## Paladin79

I may have to buy one, that does sound tempting. I already have someone lined up who can fashion a box out of solid cherry, walnut, birch, or maple; I do believe I would go that direction rather than staining the existing case. I am sure something could be done to dress up the top plate a bit as well, perhaps get a new one cut from copper or brass.


----------



## Hofy

It has been ordered.  I have just the basic amp coming as I want to do upgrades over time so I can hear the differences and improvements as I go.


----------



## ProfFalkin

hofy said:


> It has been ordered.  I have just the basic amp coming as I want to do upgrades over time so I can hear the differences and improvements as I go.



If I'm not mistaken, the speedball is on sale now too. Might as well pick it up now too save $.


----------



## Hofy

proffalkin said:


> If I'm not mistaken, the speedball is on sale now too. Might as well pick it up now too save $.


 
 Yes it is, but I am really pushing it with the extra funds right now.


----------



## ProfFalkin

hofy said:


> Yes it is, but I am really pushing it with the extra funds right now.



I know how that goes! Anyway, thought I'd be helping. Enjoy the build!


----------



## Paladin79

I am sure it has been discussed in here but how much difference does the Speed Ball upgrade make? Has anyone done the upgrade and not noticed a difference?
  
 thanks


----------



## FunyunBreath

Not 2 long ago I had 2 Cracks in my possession because I had the itch to build it again. I built my second Crack without the SB at first so I could do some proper A/B tests with the same tubes in each. Long story short there's a pretty significant difference. It really is preference though, the amp sounded a bit warmer and more "tubey" without the SB but at the expense of clarity and detail in the highs and low end. In the end, I installed the speedball in my second build.


----------



## Paladin79

funyunbreath said:


> Not 2 long ago I had 2 Cracks in my possession because I had the itch to build it again. I built my second Crack without the SB at first so I could do some proper A/B tests with the same tubes in each. Long story short there's a pretty significant difference. It really is preference though, the amp sounded a bit warmer and more "tubey" without the SB but at the expense of clarity and detail in the highs and low end. In the end, I installed the speedball in my second build.


 

 Great info! Thanks so much. A Crack with speedball it shall be then.


----------



## vintinfinity

I saw a post on bottlehead awhile back about grounding the headphone jack or something along those lines to mitigate the slight voltage spike when the amp is turning on... does anyone have a link? Can't find it now. 
  
 It's not included in the instructions, but was on BH forum for a suggested mod.


----------



## Allanmarcus

vintinfinity said:


> I saw a post on bottlehead awhile back about grounding the headphone jack or something along those lines to mitigate the slight voltage spike when the amp is turning on... does anyone have a link? Can't find it now.


 

 If you buy a new one, the errata is included in the manual, so just follow the directions in the manual.


----------



## zuber

tom-s said:


> For all those looking for some Crack, it's on SALE! : http://bottlehead.com/?product=crack-otl-headphone-amplifier-kit


 

*Tom-s* I owe you a beer, or a couple of beers 
	

	
	
		
		

		
			





.
  
 I placed an order for Crack with Speedball 8 days ago. Now, Crack is on sale. So, I had contacted Bottlehead and received a refund of 115$ 
  
 Just a few emails and that's it. Great customer support!
  
 Now I am waining for my kit to be shipped.


----------



## Doc B.

Before everyone who ordered a Crack in the past seven years calls for a refund -
  
 We issue coupons for discounts on future purchases, not refunds. Some restrictions on what the coupon may be used for apply. We only do this for kits ordered close to the sale date, like within a week before. If the kit was always on sale it would never really be on sale, dig?
  
 You can subscribe to the Bottlehead Forum and opt to get email notification next time something goes on sale. 
  
 Thanks to everyone who is ordering! We are gonna be very busy around here for a while...
  
 Lastly, a small plug for the Port Townsend Record Show this Saturday. This is the second year, and I hear the first year was pretty successful. We'll be there demoing phono preamps and headphone amps. You are welcome to stop by and listen to your show purchases.


----------



## buke9

Well since I was going to have to buy some leds to fix mine I thought why not go ahead and build my own also. The price is just too good to pass up. Paladin79 I was thinking of building my own case if it turns out good I'll let you know. I have a boatload of walnut but have to find someone to resaw it for me as it is in 2 inch or more rough cut slabs.


----------



## vintinfinity

allanmarcus said:


> If you buy a new one, the errata is included in the manual, so just follow the directions in the manual.


 
 I already have one built that needs to be altered, only have an old manual (if I can even find it) ... the new one is password protected on bottlehead's site


----------



## Paladin79

buke9 said:


> Well since I was going to have to buy some leds to fix mine I thought why not go ahead and build my own also. The price is just too good to pass up. @Paladin79 I was thinking of building my own case if it turns out good I'll let you know. I have a boatload of walnut but have to find someone to resaw it for me as it is in 2 inch or more rough cut slabs.


 
 Buke, I already have a machine shop with cnc equipment who will do most anything I want with a top plate. I am thinking of going Steampunk with copper or brass and those materials are readily available. The guys in the shop owe me a few favors so I may be able to help if you want a custom top plate as well. If the wood is down to the proper thickness one of my employees did an excellent job on some subwoofer cabinets for me so I definitely have someone who can build the cases for the amps. I may well be able to trade you a custom plate for some walnut if you have an interest. A 1/8 inch 12 by 8 inch plate is around $37 I believe, as of yet I do not know the exact size of the plate but I should know soon. I have a ton of electronics in my garage and will soon be swapping parts in the amp.


----------



## Allanmarcus

vintinfinity said:


> allanmarcus said:
> 
> 
> > If you buy a new one, the errata is included in the manual, so just follow the directions in the manual.
> ...


 

 pm Doc or email bottle head. I believe this is the answer, but not positive


----------



## buke9

paladin79 said:


> Buke, I already have a machine shop with cnc equipment who will do most anything I want with a top plate. I am thinking of going Steampunk with copper or brass and those materials are readily available. The guys in the shop owe me a few favors so I may be able to help if you want a custom top plate as well. If the wood is down to the proper thickness one of my employees did an excellent job on some subwoofer cabinets for me so I definitely have someone who can build the cases for the amps. I may well be able to trade you a custom plate for some walnut if you have an interest. A 1/8 inch 12 by 8 inch plate is around $37 I believe, as of yet I do not know the exact size of the plate but I should know soon. I have a ton of electronics in my garage and will soon be swapping parts in the amp.


Here is some of what I have. this is the new stuff like 10 years old. This is much older almost as much as me. There is a peice of Cherry on top of the first pic that I remember is the earliest.


----------



## Paladin79

buke9 said:


> Here is some of what I have. this is the new stuff like 10 years old. This is much older almost as much as me. There is a peice of Cherry on top of the first pic that I remember is the earliest.


 
 We will have to talk once I get the amp. I may well have a couple top plates made just for trading purposes. Regardless, I am glad to see you have such a selection to choose from.
  
 It appears to me that you can flip the top plate out of the box to work on the amp. If that is the case I would probably use the original box for that purpose and then place it on a furniture grade box for normal use and a better look. I could be wrong in this assumption of course.
  
 I have done things in red oak like this bow rack but I do want a nice close grained dark wood for the amp, it should go better with the look I want to achieve. I will have to be careful with screws because some dissimilar metals react and if I use copper or brass I am considering hand hammered copper rivets but I have not thought it all through yet. I just ordered the Bottlehead Crack so I hope to get to work on it soon.


----------



## mds2004

I have a crack with speedball ordered. Would it not work with the Monoprice Monolith M1060 due to them only being 50 ohms, or do I need to buy another pair like the HD650 for the crack?


----------



## Keithpgdrb

mds2004 said:


> I have a crack with speedball ordered. Would it not work with the Monoprice Monolith M1060 due to them only being 50 ohms, or do I need to buy another pair like the HD650 for the crack?


 

 the crack is not designed to work with your monolith.  you will get sound, it will not sound good.  you would want a higher ohm headphone.  Beyer dynamic or sennheiser come to mind.


----------



## JamieMcC

mds2004 said:


> I have a crack with speedball ordered. Would it not work with the Monoprice Monolith M1060 due to them only being 50 ohms, or do I need to buy another pair like the HD650 for the crack?


 
  
  
 Try it and see you might be surprised.


----------



## deserat

mds2004 said:


> I have a crack with speedball ordered. Would it not work with the Monoprice Monolith M1060 due to them only being 50 ohms, or do I need to buy another pair like the HD650 for the crack?


 


 I don't even know what a Monolith M1060 is... but can tell you that no headphone I have plugged into a Crack that was under 300 ohms made me happy. HD 600, HD 800 both (300 Ohm ) with the Crack... wow sounds amazing!  HD 598 ( 70 Ohm ), HE 560 (  45 Ohm ), Mr Speaker Ether ( 23 Ohms ) OMG that's terrible...  

 I've settled on a Lyr 2 with the Ether C. Good for work where people are annoying. Almost as good, for ALOT less money, is the HD 600 and Crack.  What  makes the different pairings good, isn't the same. The former more analytical and detailed,  the latter more musical and holographic. The Ether C paired with the Crack, like listening with mud in your ear. The HD 600 with the Lyr 2, like listening in a room filled with tin foil and glass. 

 I'm not an expert... far far from it.. but I think the general wisdom is true. Crack needs high impedance cans.  High impedance cans need high impedance Amps. Plugging a 50 Ohm Can into the Crack ... it's a fun experiment... but in my experience one that leads to not wanting to  do it again.

 I seem to have caught from various threads that the rule is a headphone should be 3 to 4 times the output impedance of the amp (Smarter people please correct me.)  The crack is about 100 - 120 ohm. The 2nd most popular mod ( a 5998 tube) drops it to about 90. 

 Anyway, my vote... plug the 50 Ohm can's in, but make sure you have the HD650 or 600 on next day shipping.

 Just wanted to make it clear. The Crack rocks. I prefer it to the Lyr 2, just not with low z headphones. It's is what I'm using at home until i finish building the mainline. And since it's my first DIY, it's pretty unlikely I'll ever part with it.


----------



## adydula

I have several headphone amps, mostly solid state DIY versions of great designs....and went thru a Schitt Lyr and Asgard.

I have tried several lower impedance headphones with my Bottlehead Crack with Speedball and they work, but not as well on other non OTL amps for sure.

My favorite headphones are 300 and 600 ohms and the Crack is a wonderful pairing for these, and I spend a lot of time listening to this combination and used my other amps for the best performance IMO with the lower impedance cans.

Recently I have a Schitt Vahalla2 on its way to compare it with the Crack and to see how well the lower Z cans will play with it...seeing how one if its design points was to be able to use a wider range of "Z" cans ....I will do a extensive listening test with the Crack and the Vahalla2 and post in a seperate thread.

Alex


----------



## Paladin79

adydula said:


> I have several headphone amps, mostly solid state DIY versions of great designs....and went thru a Schitt Lyr and Asgard.
> 
> I have tried several lower impedance headphones with my Bottlehead Crack with Speedball and they work, but not as well on other non OTL amps for sure.
> 
> ...


 

 I have a Schiit Valhalla 2 among my amps and love it but I generally use Alpha Primes and I would be curious if anyone likes them with the Crack. (they are fairly low impedance around 50 ohms as I recall) I ordered a Crack but it may take as much as four weeks to get to me since I bought it on sale. I have a feeling I will be shopping for higher impedance headphones soon lol.


----------



## adydula

Just got the V2, and its working fine, will update later.
  
 Alex


----------



## Paladin79

If any of you do own the MrSpeakers Alpha Primes I would be curious how you like them with the Bottlehead Crack?
  
 If not a good match I will probably grab some HD 650's unless there is a better choice for similar money.


----------



## LikeABell

4 hours of soldering in and I have the Speedball installed.
  
 Just poured myself a drink and pumping the jams! Sounds promising so far.


----------



## adydula

Congrats ....enjoy your work!!
  
 Music always sounds good with a cold one!!! lol!
  
 Alex


----------



## Allanmarcus

adydula said:


> Congrats ....enjoy your work!!
> 
> Music always sounds good with a cold one!!! lol!
> 
> Alex


 

 Sounds great with hot coffee and Irish Cream too!


----------



## Paladin79

I have a few weeks before I can build mine and I need the original metal plate to copy before I can have another version made. (unless someone out there has an accurate template.) In the meantime my workbench awaits the kit:
 That is an older photo, I have since had to move the Jagermeister machine.


----------



## ProfFalkin

paladin79 said:


> I have a few weeks before I can build mine and I need the original metal plate to copy before I can have another version made. (unless someone out there has an accurate template.) In the meantime my workbench awaits the kit:
> 
> That is an older photo, I have since had to movet the Jagermeister machine.



Have you had many Jagermeister + soldering adventures? I wouldn't think the two would mix well. Hehehe


----------



## FunyunBreath

deserat said:


> I don't even know what a Monolith M1060 is... but can tell you that no headphone I have plugged into a Crack that was under 300 ohms made me happy. HD 600, HD 800 both (300 Ohm ) with the Crack... wow sounds amazing!  HD 598 ( 70 Ohm ), HE 560 (  45 Ohm ), Mr Speaker Ether ( 23 Ohms ) OMG that's terrible...
> 
> I've settled on a Lyr 2 with the Ether C. Good for work where people are annoying. Almost as good, for ALOT less money, is the HD 600 and Crack.  What  makes the different pairings good, isn't the same. The former more analytical and detailed,  the latter more musical and holographic. The Ether C paired with the Crack, like listening with mud in your ear. The HD 600 with the Lyr 2, like listening in a room filled with tin foil and glass.
> 
> ...


 
  
 I would agree with this as well. Anytime I've plugged any headphone into my crack that was under about 100ohms it just sounds distorted at reasonable listening volumes. Crank it a little bit higher than that and it sounds like FM radio haha.


----------



## adydula

Well, I spent a few hours this morning setting up and level matching the volume settings on my Crack with Speedball and the new Schitt Vahalla2.
  
 I have not done my usual blind AB tests yet, but I can tell you what I "think" I am hearing so far....
  
 I use a 1Khz test tone and set levels to 80db and then 85db, the difference between the two isn't that much physically on the actual vol knobs but its a really "perceptible" loud difference to me actually listening.
  
 The crack is a little more difficult to actually set this level at, 80db no issues,but 85 seem to be in a range on my Crack that takes some attention to setting it up. I use a SPL meter I have had for years and a home-brew acoustic coupler to set the levels. With both set to these 2 levels I noticed it was easier to tell differences IMO at the lower spl level. Weird.
  
 Sometimes when comparing amps, there is the tendency to crank up the volume level to make u for deficiencies so setting the levels to match is really important.....
  
 Listening to my ususal favorites and demo tracks there is an immediate wow such a difference....between the two....I bought the Vahalla 2 because I wanted to see what it sounds like and it has more power available at 300 and 600 ohms compared to the Crack. My headphones range from 35 to 600 ohms. The Crack of course is not designed to work with low impedance headphones but the Vahalla 2 is. Schitt doesn't state its the cats meow with the lower headphones but it should be much better than their first generation of this amp.
  
 Like with many new purchases there is that "human" element that wants the new stuff to be "better"...or you might have just wasted several hundred dollars! I am no exception.
  
 So I have only had the Schitt Vahalla2 for less than 2 days and about 4 hours of ply time with the stock tubes while my good old friend the Crack I have had for almost two years and a dozen sets of tubes. It has been my go to amp for my high impedance headphones.
  
 Listening to the Vahalla 2 I was amazed at how clear and transparent it sounds, using the higher gain setting, recommended for higher impedances. It has more than enough power and doesn't strain at all driving the 300 or 600 ohm Beyers. The sound is very clear, open and its easy to articulate musical instruments. Very much like a solid state amp, than a tube amp. Really shocking in a good way to me. Most good amps IMO take some real listening and "straining" to hear differences which to me tells me that they are really close in performance.
  
 Comparing to the Crack the immediate thing is the soundstage on the Crack seems more open and wider...but more recessed. The drum beats seemed to be "louder" or maybe more "boomy" not a bad or poor bass but just more fuller and "wider" in sound. The Vahalla 2 bass was less thick, but very well done too. My first and immediate impression was the Crack soundstage being so different and musical was startling. Depending on what material you play and how It was recorded they both sound very well.
  
 Playing rock music like the remastered "The Doors" the drum whacks on the Vahalla 2 will make your ears bleed...they are really, really well recreated on my T1's a 10 out of a 10 IMO. The Crack is just a little behind a 9 out of a 10 to me. That said the overall presentation eeks out to the Crack...its just softer and more musical to me.
  
 Now all this was with the higher impedance T1's....when I shifted to a lower impedance set of headphones the story changes quite a lot.
  
 I have a set of Beyer DT1350's and they just sit there not being used much since I have had my T90s and T1's and several other headhones, Tyl over at innerfidelity liked these a lot, which is saying something (LOL). They have small transducers, don't fit over my ears and when playing with other SS amps they have a smaller soundstage and presence to me. The T90s and T1's blow them away.
  
 Well that was until the Vahalla 2 arrived..
  
 I have tried these 80 ohm headphones on the Crack and immediately I know this was not the amp for these headphones they played but well....not that well at all. So the Crack is relegated to the 300+ plus range for sure.
  
 The Schitt Vahalla 2 was re-designed to work with a wider range of headphones and this it does very well IMO. Actually when I put the DT1350s into the V2, I was really blown away...playing the original Trinity Series of Cowboy Junkies the bass response and soundstage and ambient background reverberation was better than any presentation of these headphones on any other amp I have. It shocked me so much that I had to check to see if I had these on my head!! These were played with the lower gain setting. The really low bass was actually to me better than the T1's!  
  
 So I will next setup up a blind listening session and invite a few audio friends over and test them to see what they hear in a blind test environment. its the only way to me to see how they both stand up.
  
 I like building stuff, and the Bottlehead Crack with the Speedball mod to me is one of the best tube OTL amps that is affordable and competes with higher priced amps and does so very well with high impedance headhones, if you have this amp you cant go wrong, its that nice. (speedball is a must :>).....).
  
 That said if you like playing around with amps, and I do, I had to try this amp, it has gobs of power at 300 ohms (800mw RMS). The Crack volume knob has to be cranked up 3/4 or so where as the Vahalla2 is only cranked up to 1/3 of the way, but to be fair the gain has to be factored in here. But the Vahalla 2 will make most higher impedance cans dance very well.
  
 If you don't like building stuff the Vahalla 2 is a good choice, its well built, solid and the stock tubes are to me just wonderful. I feel no need to go chasing NOS tubes. The price you pay for them is getting well, ridiculous IMO. Schitt will sell you a et of 4 for $40, now that's a great deal to me.
  
 I am not going to get rid of my Crack for sure and the Vahalla 2 is also going to be around for a long time as well....both companies have real winners here....
  
 All the best
 Alex


----------



## Paladin79

funyunbreath said:


> I would agree with this as well. Anytime I've plugged any headphone into my crack that was under about 100ohms it just sounds distorted at reasonable listening volumes. Crank it a little bit higher than that and it sounds like FM radio haha.


 
 Great info, I will get some 650's on the way, thanks!


----------



## Paladin79

proffalkin said:


> Have you had many Jagermeister + soldering adventures? I wouldn't think the two would mix well. Hehehe


 
 I am not a huge fan of the drink but I ended up with the machine when I bought the contents of a bar. I am more apt to chill single malt scotch a bit in it. Soldering is second nature to me I have been doing it so long I rarely have misadventures but I try to limit consumption when soldering, 
  
 I am curious what the average build time is for folks assembling the amp. Looking at the parts, I am hoping to finish one in six hours or so including the Speedball upgrade.


----------



## Timoteo80

adydula said:


> Well, I spent a few hours this morning setting up and level matching the volume settings on my Crack with Speedball and the new Schitt Vahalla2.
> 
> I have not done my usual blind AB tests yet, but I can tell you what I "think" I am hearing so far....
> 
> ...




I really enjoyed your write up! Thank you for that comparison.


----------



## Timoteo80

paladin79 said:


> I am not a huge fan of the drink but I ended up with the machine when I bought the contents of a bar. I am more apt to chill single malt scotch a bit in it. Soldering is second nature to me I have been doing it so long I rarely have misadventures but I try to limit consumption when soldering,
> 
> I am curious what the average build time is for folks assembling the amp. Looking at the parts, I am hoping to finish one in six hours or so including the Speedball upgrade.




Took me 3 evening sessions totaling approx 9hrs. Keep in mind it was my first build & I hadn't soldered in many years. So I took my time, enjoying the actual build. I have not installed the Speedball yet. It's sitting on the shelf waiting for the upgrade bug to bite. Really enjoying the stock Crack so far. Good luck on your build!!

BTW: the 9hrs did not include all the time I spent polishing the top plate, and staining/clear coating the wood base.


----------



## Paladin79

My shop now, I have multiples of everything so I rarely have to look for a tool or change tips in an iron.
 Quote: 





timoteo80 said:


> Took me 3 evening sessions totaling approx 9hrs. Keep in mind it was my first build & I hadn't soldered in many years. So I took my time, enjoying the actual build. I have not installed the Speedball yet. It's sitting on the shelf waiting for the upgrade bug to bite. Really enjoying the stock Crack so far. Good luck on your build!!
> 
> BTW: the 9hrs did not include all the time I spent polishing the top plate, and staining/clear coating the wood base.


 
 I will do the build and basic testing with the provided base but will be swapping it out at some point so I doubt I will finish it. The top plate I may clear coat if I go solid copper but I do not include that in build time. I will also not include time upgrading components but once all parts are in hand and organized, it sounds like six hours is not out of the question, seven if I stop for lunch. Very nice job by the way. I work long hours during the week so it will be a Saturday project for me and I would want to hear it that evening.


----------



## Timoteo80

paladin79 said:


> I will do the build and basic testing with the provided base but will be swapping it out at some point so I doubt I will finish it. The top plate I may clear coat if I go solid copper but I do not include that in build time. I will also not include time upgrading components but once all parts are in hand and organized, it sounds like six hours is not out of the question, seven if I stop for lunch. Very nice job by the way. I work long hours during the week so it will be a Saturday project for me and I would want to hear it that evening.




Since you have soldering skill from the sound of it, I have no doubt you could do it in your time frame. Thx for the compliment. I hear ya on the long work week hours, I've been working 6-7 day weeks lately. Kind of a bummer when I want some time to enjoy my Crack/HD600 combo. Enjoy your build bud!! I did


----------



## DavidA

Quote:


paladin79 said:


> I will do the build and basic testing with the provided base but will be swapping it out at some point so I doubt I will finish it. The top plate I may clear coat if I go solid copper but I do not include that in build time. I will also not include time upgrading components but once all parts are in hand and organized, it sounds like six hours is not out of the question, seven if I stop for lunch. Very nice job by the way. I work long hours during the week so it will be a Saturday project for me and I would want to hear it that evening.


 
 Nice shop setup, which I lived in a house where I could set up a work area.  It took me 14 hours to build my Crack, had too much help from my GF and a few too many bottle of wine during the process, started at 6pm finished at 10am, but it worked.  My work area:


----------



## Tom-s

Like in your picture, needle holders (and maybe a scalpel) are really helpful when working on projects like these.
 I also have a Gemini forceps laying around for hard to reach areas. 
 Being able to use Cremaillere is really helpful for builds.


----------



## Paladin79

timoteo80 said:


> Since you have soldering skill from the sound of it, I have no doubt you could do it in your time frame. Thx for the compliment. I hear ya on the long work week hours, I've been working 6-7 day weeks lately. Kind of a bummer when I want some time to enjoy my Crack/HD600 combo. Enjoy your build bud!! I did




I often work 7 days a week as well if my employees are behind on a cable building project. Then I might solder for 20 hours or more on a weekend. I have set up entire production lines to stuff and solder PC boards so it is normal for me to work quickly and efficiently. In 2015 there were maybe 3 months where I did not solder on weekends. I have also taught electronics and had tube theory so recognizing components and reading color codes on resistors comes easily for me. 



I may speed things up a bit by using shielded three or four conductor ofc wire in place of braiding it like some of the photos I have seen show. I will be swapping out capacitors so I may change the layout slightly as well. I have access to most any wire including occ copper, silver, litz, OFC etc. that I use for headphone cable building as well. If I come across any obvious upgrades I will try to share them here. I have had experience upgrading old Dynaco amps, preamps and tuners so this build should go a lot quicker. My only concern is more for appearance sake than anything else. I will have to locate some tube sockets that will match the look I want to achieve, I hope to have only copper, brass or gold showing on the top plate. With any luck I may be able to convert some very rugged CHC Silverado headphones over to high impedance so they matched the look of the amp.

There are dark brown bakelite tube sockets out there with a gold or brass plated finish that should go nicely, I just found a nine pin version.

http://www.ebay.com/itm/4pc-9pin-Bakelite-vacuum-tube-socket-valve-base-12AX7-12AU7-ECC83-6N11-audio-amp/151026213631?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D2%26asc%3D41376%26meid%3Db2df8604f5a248618c74274ab186c1cd%26pid%3D100005%26rk%3D5%26rkt%3D6%26sd%3D331092292624


----------



## neddoge

Crack + SB inbound, ordered a new iron and a few extra goodies to prep for this DIY.
  
 I'm pumped...... And I have 500 pages to read through!


----------



## mds2004

Inbound as in shipped or ordered? I only ordered on March 5th and wasn't sure how far out the backlog is.


----------



## Paladin79

I ordered mine a week ago and I was told it could take four weeks for the Crack to be shipped. They have to get the wooden cabinets made and I am sure they were flooded with orders because of the sale.


----------



## mds2004

Thanks for the response. I was assuming the worst of 6 weeks from the website, solely based on the sale. 4 weeks isn't bad as I thought.


----------



## Paladin79

mds2004 said:


> Thanks for the response. I was assuming the worst of 6 weeks from the website, solely based on the sale. 4 weeks isn't bad as I thought.


 
 Their customer service is really good about responding to emails if you do begin to wonder. I asked them for a drawing of the top plate but have not heard back on that though. Until I get that made i will not be able to begin the build since it would be time consuming to swap all components from the original plate.


----------



## Allanmarcus

For those about to build a Crack. I _highly_ recommend you look at the Bottlehead Crack forum. Good tips and answers to many questions there.
  
 http://bottlehead.com/smf/index.php?board=24.0


----------



## Paladin79

allanmarcus said:


> For those about to build a Crack. I _highly_ recommend you look at the Bottlehead Crack forum. Good tips and answers to many questions there.
> 
> http://bottlehead.com/smf/index.php?board=24.0


 
 I skimmed it a while back, there is some good info there. thanks


----------



## Doc B.

paladin79 said:


> Their customer service is really good about responding to emails if you do begin to wonder. I asked them for a drawing of the top plate but have not heard back on that though. Until I get that made i will not be able to begin the build since it would be time consuming to swap all components from the original plate.


 
 Sorry you didnt get a response. We cannot share our CAD files, as they are a part of Bottlehead's intellectual property. Your best bet for copying our panel design is to measure the plate that ships with your kit.


----------



## Timoteo80

paladin79 said:


> I ordered mine a week ago and I was told it could take four weeks for the Crack to be shipped. They have to get the wooden cabinets made and I am sure they were flooded with orders because of the sale.




Well it took 6 weeks for me to get my SB upgrade sent. When I originally ordered my Crack it arrived in just under 5. Be patient it will come tho!!


----------



## Paladin79

doc b. said:


> Sorry you didnt get a response. We cannot share our CAD files, as they are a part of Bottlehead's intellectual property. Your best bet for copying our panel design is to measure the plate that ships with your kit.


 
 Will do and I was not complaining, just trying to plan ahead a bit and have the plate ready to populate with associated parts. I just prefer another look besides the silver plate.
  
 Another thought might be if I sent you my UPS account number in case you had any top plates in stock now and you were able to ship just that prior to the remainder of the parts. I have already paid for the amp of course and this would cost you no extra shipping but I understand if it is not feasible. My only intent is to get someone started making the plate while he still remembers he owes me a favor lol.
  
 Tom


----------



## neddoge

mds2004 said:


> Inbound as in shipped or ordered? I only ordered on March 5th and wasn't sure how far out the backlog is.


 

 ​Like you, I ordered thereabout Mar5 so it'll be here when it gets here.  I'm making a few cables in the meantime to get my hand in it for soldering.


----------



## TeeReQs

paladin79 said:


> Will do and I was not complaining, just trying to plan ahead a bit and have the plate ready to populate with associated parts. I just prefer another look besides the silver plate.
> 
> Another thought might be if I sent you my UPS account number in case you had any top plates in stock now and you were able to ship just that prior to the remainder of the parts. I have already paid for the amp of course and this would cost you no extra shipping but I understand if it is not feasible. My only intent is to get someone started making the plate while he still remembers he owes me a favor lol.
> 
> Tom




What do you plan on doing differently with the plate from the stock one?


----------



## Paladin79

teereqs said:


> What do you plan on doing differently with the plate from the stock one?



Nothing against the original look but I prefer to use a copper or brass top plate, maybe brown Bakelite sockets. I am going to design and build a matching headphone rack. Think steampunk; since it will be sitting out, I want to go for a specific look. It makes more sense to me to have the top plate ready and not move parts from one to the other but that is just my approach. I may buy a second one and leave it stock so I can have a baseline when I start upgrading the fancier one. Since college I have worked in electronics for four decades and have plenty of test equipment and precision components in my shop so to do the build is not a huge challenge for me but outward appearance is a factor. I may go as far as upgrading the drivers in some CHC headphones and using all clear jacketed OCC copper brsided cables for aux and headphone cables but that is not a tough upgrade to make. If anyone has suggestions for volume knob or matching RCA connectors that might go with my theme, lay them on me! 



Tom

Some connectors use nickel plated brass, I might be able to remove the nickel plating from the backshells for an all brass and copper look. Either that or have a buddy make them on a metal lathe, that may be doable as well. I am also more inclined to put the AC input and power switch on the back of the box on another copper plate. In some photos I have seen what look like a couple extra holes near the front tube socket. Making my own plate will allow me to make desired changes. Maybe more decorative vents or a brass toggle switch mounted toward the front. I have other thoughts that I will disclose when finished. 

I will use Aux cables similar to this, OFC, french braid, silver plated copper cable.


----------



## Doc B.

paladin79 said:


> Will do and I was not complaining, just trying to plan ahead a bit and have the plate ready to populate with associated parts. I just prefer another look besides the silver plate.
> 
> Another thought might be if I sent you my UPS account number in case you had any top plates in stock now and you were able to ship just that prior to the remainder of the parts. I have already paid for the amp of course and this would cost you no extra shipping but I understand if it is not feasible. My only intent is to get someone started making the plate while he still remembers he owes me a favor lol.
> 
> Tom


 
 Unfortunately the accounting that is required when we have to start sending kits in multiple shipments is not feasible, particularly when we have so many to manufacture and deliver from the recent sale. If every kit has a different set of parts shipping at different times we will probably ****** up royally from losing track of who is owed what parts. I know it probably doesn't seem like it from the end user perspective, but we're constantly updating inventory on several thousand different parts that are going into orders for around 30 different types of kits. When I say "we" I mean 3.5 employees, and one of them is doing most all of that inventory control and fulfillment. So we have to keep the products we ship uniform in their packaging to maintain consistent production.


----------



## Paladin79

That is fine. Can you maybe tell me the outside dimensions of the top plate, just a ballpark so I can get some blank copper on the way? 11x9 inches or some such.
  
 thanks
  
 Tom


----------



## TeeReQs

@Paladin79 I actually thought about possibly cutting a different top plate as well once I get mine. I run a waterjet, and a Copper or Brass top might look pretty good. Or even a mirrored stainless. We'll see.


----------



## Paladin79

teereqs said:


> @Paladin79 I actually thought about possibly cutting a different top plate as well once I get mine. I run a waterjet, and a Copper or Brass top might look pretty good. Or even a mirrored stainless. We'll see.


 

 Very cool, after eliminating some of the openings for female AC socket and switch I may do mine myself. I have a nibbler and a large hole punch. Copper is a lot softer so I may just go brass and be done with it. I may also shift the location of a couple things but not by much.
  
 I have some RCA connectors that have a brass backshell that will work well for my aux cables. I just have to decide if I want those poking out of the top of the plate or not, I may end up mounting the jacks on the back of the box along with the AC input.


----------



## mds2004

That is exactly what I was hoping to do. I am wanting the patina'ed copper look for the plate.


----------



## Paladin79

I found some of the switches I want to use on Ebay and they even said beside them, look "steampunk" lol. Luckily I found someone selling just one, if I end up with a dozen of them I may be mailing them out to other people just to unload them.  There are also some really neat brass nautical switches out there with porcelain bodies. Suddenly I am not feeling so bad about the idea of brass or copper. In my mind a dark wood would be best for the base and I can practice a few stains before I decide. Mahogany and brass can work though.
  
 http://badnixie.com/Web_Files/IMG_1209.JPG


----------



## ScottFW

> Originally Posted by *Paladin79* /img/forum/go_quote.gif
> Can you maybe tell me the outside dimensions of the top plate...


 
 It's darn close to 10" x 6". After assembling my wood base I measured the recess the plate sits in at approx 6 1/32" x 10 1/16" and that allows a slight gap all around.


----------



## Paladin79

scottfw said:


> It's darn close to 10" x 6". After assembling my wood base I measured the recess the plate sits in at approx 6 1/32" x 10 1/16" and that allows a slight gap all around.


 

 Cool that info helps a lot, thanks. That is not a huge plate so 1/8 inch copper might even do the trick.


----------



## kxanthop

I am pretty sure these have been answered before, but the thread is huge: 
I) where can I get tubes for my Crack in the EU, other than eBay? I am still using the stock tubes and it's time I upgraded.
II) is there a pair of headphones that sounds substantially better than the HD650s out of the Crack (with the Speedball)? I tried the HD800s but in my opinion were not that much better than the HD650s when driven by the Crack
III) it's been a few days that the attenuator had been making rapping sounds when i turn the volume knob between specific positions. The noise is only heard when I turn the knob. I'd there anything I can do, or the only remedy is changing the attenuator?
Many thanks!


----------



## Allanmarcus

152mm x 253mm
  
 I think


----------



## Paladin79

kxanthop said:


> I am pretty sure these have been answered before, but the thread is huge:
> I) where can I get tubes for my Crack in the EU, other than eBay? I am still using the stock tubes and it's time I upgraded.
> II) is there a pair of headphones that sounds substantially better than the HD650s out of the Crack (with the Speedball)? I tried the HD800s but in my opinion were not that much better than the HD650s when driven by the Crack
> III) it's been a few days that the attenuator had been making rapping sounds when i turn the volume knob between specific positions. The noise is only heard when I turn the knob. I'd there anything I can do, or the only remedy is changing the attenuator?
> Many thanks!


 

 There are products out there for cleaning potentiometers, Deoxit comes to mind but I have known of people even using WD 40 or silicone spray. It may or may not work if the resistive layer is pitted but it might save you some money to give it a try.


----------



## kxanthop

Many thanks! I think I should have some wd40 somewhere, i will give it a try.


----------



## i luvmusic 2

1/8" copper plate? WOW.....


----------



## buke9

Copper is not real strong so it needs to be a bit thicker. Should look awesome though.


----------



## i luvmusic 2

I know that copper is softer but 1/8" probably won't be that cheap,will at least in my TRADE


----------



## buke9

i luvmusic 2 said:


> I know that copper is softer but 1/8" probably won't be that cheap,will at least in my TRADE


No not cheap at all but what is in this hobby?


----------



## Paladin79

i luvmusic 2 said:


> I know that copper is softer but 1/8" probably won't be that cheap,will at least in my TRADE


 
 Luckily I can solder to copper and if need be I can reinforce it underneath at least around the transformer area. In a show of homage to Michael Faraday I am working on another idea or two pertaining to the surface plate.  The copper plate itself should be under $30, I plan to get enough to do a back plate and a small switch plate for the front. Correction $36.00, I just bought it.
  
 If you will it, it is no dream.  Theodor Herzl  (slightly paraphrased in The Big Lebowski.)


----------



## i luvmusic 2

Burn $$$$
	

	
	
		
		

		
		
	


	



  
 Did i get it right?


----------



## i luvmusic 2

paladin79 said:


> i luvmusic 2 said:
> 
> 
> > I know that copper is softer but 1/8" probably won't be that cheap,will at least in my TRADE
> ...


 
 Sure copper look nice as long as it is done correctly and depending on what type of copper you are working on.


----------



## Paladin79

i luvmusic 2 said:


> Burn $$$$
> 
> 
> 
> ...


 
 I just corrected my previous post, final cost is $36 for said 1/8" copper.


----------



## i luvmusic 2

That is a good price.


----------



## buke9

i luvmusic 2 said:


> Burn $$$$
> 
> Did i get it right?


Why not?


----------



## Paladin79

buke9 said:


> Why not?


 
 Why not indeed. Cosmetics are important and how long does it take to polish the original plate or sand and stain the original box when I can have mahogany or walnut? I already saved $100 getting the amp on sale and I am building my own aux cables and headphone cables for whichever 300 or 600 impedance cans I attach to the amp. I am in a college town and constantly have science people over from the local university so it should be a fun conversation piece. Most from a sci-fi book club will appreciate the steampunk approach. Oh yes my wife will probably love it just because of the looks but it will also be one piece of electronics my son does not own so even he might be impressed.


----------



## Paladin79

i luvmusic 2 said:


> Sure copper look nice as long as it is done correctly and depending on what type of copper you are working on.


 
 Naturally I will post some photos when completed and you can judge for yourself whether it looks nice. I have to admit I do not know the exact type of copper I will be working with. it is shiny and um copper colored.
	

	
	
		
		

		
		
	


	




 
  
 I am more apt to steer toward this type of patina:
 And if I can find it, some really old quartered oak that is nice and dark:

 Maybe something showing some wear, and age. This is the color of a 1914 Kimball upright piano we once owned. It took a while to achieve kind of a crackled varnish appearance but in my humble opinion, that might look ok.


----------



## buke9

paladin79 said:


> Naturally I will post some photos when completed and you can judge for yourself whether it looks nice. I have to admit I do not know the exact type of copper I will be working with. it is shiny and um copper colored.:wink_face:
> 
> I am more apt to steer toward this type of patina:
> 
> ...


I like the patina idea. Quarter sawn oak might be a little hard to find as mostly veneer now . If you have a WoodCraft store near you they have a lot of different woods and some wild exotics.


----------



## deserat

Nice can't wait to see how this turns out. I started off down that road but ultmately ended up blackening the aluminum and burning the wood.  I've got a crack-a-twoa that I'm being more patient with. Though it'll still likely be alumi black, I'm playing with etching ( chemical, dremel, and CNC ) to put patterns into the to top plate.  Not sure i have the patience to work through translating designs in to CAD.


----------



## Paladin79

buke9 said:


> I like the patina idea. Quarter sawn oak might be a little hard to find as mostly veneer now . If you have a WoodCraft store near you they have a lot of different woods and some wild exotics.




I am not sure of the exact dimensions of the box but I have my eye on a couple old pieces of furniture that have some damage but probably enough clear wood for my purpose. 3/4 inch roughly, solid wood and I would not be destroying a beautiful piece of furniture. I also know a guy who cuts his own trees if I want to go new wood.


----------



## buke9

paladin79 said:


> I am not sure of the exact dimensions of the box but I have my eye on a couple old pieces of furniture that have some damage but probably enough clear wood for my purpose. 3/4 inch roughly, solid wood and I would not be destroying a beautiful piece of furniture. I also know a guy who cuts his own trees if I want to go new wood.


 Lookslike outside 7 3/32 by 11 3/32. Just a shade under 3/4 inch thick. The inset is 6 x 10 "'s. They are using 3/4" wood.


----------



## Paladin79

buke9 said:


> Lookslike outside 7 3/32 by 11 3/32. Just a shade under 3/4 inch thick. The inset is 6 x 10 "'s. They are using 3/4" wood.




That is good info and close to what I was figuring. I may have the copper plate as early as Monday but need to get the kit before I start cutting holes. The box may be the last thing I do so I have some time to get it right. Also going for the patina look offers some flexibility handling the copper. Dings and scratches will matter less.


----------



## buke9

paladin79 said:


> That is good info and close to what I was figuring. I may have the copper plate as early as Monday but need to get the kit before I start cutting holes. The box may be the last thing I do so I have some time to get it right. Also going for the patina look offers some flexibility handling the copper. Dings and scratches will matter less.


Still trying to find someone to resaw my walnut. I might use my table saw to do a sample and see if you like it.


----------



## Paladin79

I love all kinds of hardwood so I would be happy to see it. One of my employees has a small wood shop but not a planer. Another has a metal lathe. I am depending on them for a couple things. I would help if I could but my shop is nearly all electronics and tools for rental property upkeep.


----------



## buke9

paladin79 said:


> I love all kinds of hardwood so I would be happy to see it. One of my employees has a small wood shop but not a planer. Another has a metal lathe. I am depending on them for a couple things. I would help if I could but my shop is nearly all electronics and tools for rental property upkeep.


Yep need a planer . I have a jointer planer but that doesn't help if it isn't square. I'm sure there is someone in town that can do it just haven't found them yet. I'll cut some this weekend and send you a sample to see if that is up to snuff.


----------



## Paladin79

buke9 said:


> Yep need a planer . I have a jointer planer but that doesn't help if it isn't square. I'm sure there is someone in town that can do it just haven't found them yet. I'll cut some this weekend and send you a sample to see if that is up to snuff.




If I like it I am sure I can find something in my shop to send as a thank you. A Weller or Hakko station or some such. I always return a favor.


----------



## buke9

paladin79 said:


> If I like it I am sure I can find something in my shop to send as a thank you. A Weller or Hakko station or some such. I always return a favor.


No a copper plate.


----------



## Paladin79

I can do that if I decide to go with walnut. I am supposed to get mine early next week and I should be able to order another. Will you be able to make the modifications if I sent a blank plate? I am still thinking through how many holes I want to make in the top of mine. I may only have openings for the transformer and tubes and vent holes with small copper plates on the front and back for ac input, audio in, on-off switch, volume, and quarter inch jack. The last three things would be on the front plate. I have military grade plugs and jacks that I can use so I would still be able to remove the top plate for modification. I may leave a master power switch in the back but the normal on/off will be mounted on the front. I may incorporate some old analog vu meters on the front if I can find some that match in which case I may have to rethink the placement of those items. Worst case scenario is having the on off on the front left of the plate and headphone jack on the front right. I will probably do a mock up when I get the kit.
 
Tom


The Chinese make some small circular VU meters with yellow lights that are less than 1.378 inches across in black plastic cases. Imagine those mounted on a small copper plate exhibiting the proper patina. I am not real crazy about the black plastic cases but I can always paint those if need be.


----------



## HiddenFatKid

So im planning on getting a crack this summer, I have HD600's and i've been looking around for a pair of closed backs that would benefit from the Crack. Besides the DT770/1770 line, what other closed backs would benefit from the crack?


----------



## ProfFalkin

Pretty much any high impedance dynamic headphone has a good chance of pairing well.


----------



## ScottFW

Problem is, the list of fully closed-back cans that don't have severely compromised SQ in one way or another (congested, echo-ey and generally closed-sounding, and/or basshead type cans that don't appeal to me) is already somewhat short, and only a fraction of those that don't suck are in the high impedance category.
  
 One that I've always been curious about is the Beyer DT-150. A bit industrial looking, but seems to have a cult following as a not-too-closed-sounding headphone, never gotten to hear a set myself though.


----------



## Allanmarcus

hiddenfatkid said:


> So im planning on getting a crack this summer, I have HD600's and i've been looking around for a pair of closed backs that would benefit from the Crack. Besides the DT770/1770 line, what other closed backs would benefit from the crack?


 

 I think beyer is your only option for close, high impedance cans.
  
 I've heard fantastic things about the 150. If you can get over its looks, it's supposed to be awesome.


----------



## HiddenFatKid

allanmarcus said:


> I think beyer is your only option for close, high impedance cans.
> 
> I've heard fantastic things about the 150. If you can get over its looks, it's supposed to be awesome.


 
 Honestly, I love the look of the DT-150's, i'd never heard of them until ScottFW mentioned them, and looking them up, they're some rugged look cans man, i can dig it! The only thing im seeing is clamping force may be a bit of an issue, couple years ago i had to sell my AT m50's real quick because of my big-ass noggin. Would you know if the clamping force on the DT-150's is anything like that of the M50's?


----------



## Allanmarcus

hiddenfatkid said:


> allanmarcus said:
> 
> 
> > I have read that about the clamping force, but I've never tried them. I might be getting a used pair, and if I do I'll post impressions.
> ...


----------



## HiddenFatKid

allanmarcus said:


>


 
 Yes please man! That'd be awesome! The one thing holding me back from pulling the trigger once i get the crack is that clamping force, I like the looks of them, cable might be a little long, but it sounds like quite a package, and obscure too, ive never seen someone with these


----------



## DavidA

scottfw said:


> Problem is, the list of fully closed-back cans that don't have severely compromised SQ in one way or another (congested, echo-ey and generally closed-sounding, and/or basshead type cans that don't appeal to me) is already somewhat short, and only a fraction of those that don't suck are in the high impedance category.
> 
> One that I've always been curious about is the Beyer DT-150. A bit industrial looking, but seems to have a cult following as a not-too-closed-sounding headphone, never gotten to hear a set myself though.


 
  


allanmarcus said:


> I think beyer is your only option for close, high impedance cans.
> 
> I've heard fantastic things about the 150. If you can get over its looks, it's supposed to be awesome.


 

 ​The DT-150 is the closed version of a HD650 and it does sound quite good but I've only heard it twice but both times it has impressed me.


----------



## Allanmarcus

davida said:


> scottfw said:
> 
> 
> > Problem is, the list of fully closed-back cans that don't have severely compromised SQ in one way or another (congested, echo-ey and generally closed-sounding, and/or basshead type cans that don't appeal to me) is already somewhat short, and only a fraction of those that don't suck are in the high impedance category.
> ...


 

 Well, the seller has a smoker is hm home, so I passed on the sale.
  
 Also, I really really don't like the HD650, yet I like the signature beyerdynamic signature. I'm pretty surprised that the 150 and 650 sound alike, but it they do, it's good for me that passed. The HD650 is so dark to me, I cannot imagine using it with _my_ crack, which has some darkish tubes.


----------



## HiddenFatKid

I feel that man, I like a darker sound signature, but not too dark. Im coming from Hifiman HE-400's, so im trying to expand my tastes and i just fell in love with the 600's like most people do, but if the DT-150's have the sound signature of the 650's or close to the HE-400's, that might be an insta-buy for me. If i do end up getting them, it would be in the summer, but i could try and post my impressions too, i'm not that sound-savvy, but i could try my best, it'd be my frist review/impression


----------



## Paladin79

I have about a month to catch a deal on high impedance headphones before my Kit arrives so I will have a little time to build up cash reserves for either Sennheiser or Beyerdynamic. Happy St.Patrick's Day!!!


----------



## Rewrap

So I just got a pre-built Crack w/ Speedball and a bunch of tubes to use my HD 600 with. I'm seriously looking forward to listening to it. Is a Modi 2u enough as a DAC to use with it? 
  
 Tubes include:
  
 Power tubes: 1959 Chatham / Tung Sol 599 and Chatham 6AS7G
  
 Driver tubes: Philips Miniwatt E80CC, Siemens ECC82, and J J ECC82


----------



## Tom-s

I was very happy with the Modi 2U / Crack combination


----------



## MIKELAP

Got a question, would you guys know what is the Crack power tube  socket and driver socket maximum heater voltage  rating would it be 3.0A for power tube and .50A for driver ? Thanks


----------



## Tom-s

It's a total of 3.5A rating indeed for the power transformer.
 The relative currents don't really matter. 
 A 6080 tube runs @ 2.5A heater current. 
 So that's 1A to spare for the driver tube (the driver tubes for Crack i know of don't exceed 0.8A).
  
 Using 2 6BL7's (6BX7) in parallel (2x 1.5A) you can use up to 0.5A for the driver tube.


----------



## MIKELAP

tom-s said:


> It's a total of 3.5A rating indeed for the power transformer.
> The relative currents don't really matter.
> A 6080 tube runs @ 2.5A heater current.
> So that's 1A to spare for the driver tube (the driver tubes for Crack i know of don't exceed 0.8A).
> ...


----------



## ProfFalkin

mikelap said:


> So what your saying is that this 6BL7 adapter would work in a Crack



Why would you want to?


----------



## MIKELAP

Just trying to find out what i can and what i cannot do with this amp


----------



## i luvmusic 2

Hey Mike at parts connex10n 6080 US$4.50 each no need for the adapters i just got 12 of them.


----------



## MIKELAP

i luvmusic 2 said:


> Hey Mike at parts connex10n 6080 US$4.50 each no need for the adapters i just got 12 of them.


 
 I am already using these adapters with the 6BL7in my WA22 so if it works might as well put them to use .Thats a really  good deal. Got plenty of power tubes they will outlast me i afraid .


----------



## ProfFalkin

mikelap said:


> Just trying to find out what i can and what i cannot do with this amp




Fair enough. I didn't know if it offered any benefit, so I thought I'd ask. Cheers


----------



## MIKELAP

proffalkin said:


> mikelap said:
> 
> 
> > Just trying to find out what i can and what i cannot do with this amp
> ...


 
 Just tried this Double 6BL7 ADAPTER DOESNT WORK IN CRACK AND A SINGLE TUBE EITHER


----------



## MIKELAP

tom-s said:


> It's a total of 3.5A rating indeed for the power transformer.
> The relative currents don't really matter.
> A 6080 tube runs @ 2.5A heater current.
> So that's 1A to spare for the driver tube (the driver tubes for Crack i know of don't exceed 0.8A).
> ...


 
 i guess this adapter isnt wired right it doesnt work


----------



## neddoge

paladin79 said:


> I have about a month to catch a deal on high impedance headphones before my Kit arrives so I will have a little time to build up cash reserves for either Sennheiser or Beyerdynamic. Happy St.Patrick's Day!!!


 

 ​Looks like we'll both be building our Cracks at the same time 
  
 Did you get the Speedball as well?


----------



## Paladin79

neddoge said:


> ​Looks like we'll both be building our Cracks at the same time
> 
> Did you get the Speedball as well?


 
 Absolutely, and the badge, and the hat lol. I am doing a lot of customizing on it, I have already thought it all through and have some things on the way for it. The circuitry will be similar to the original design but the outside appearance is going to be quite unique.


----------



## Tom-s

mikelap said:


> i guess this adapter isnt wired right it doesnt work


 
  
@attmci has experience using 2 6bl7's?
  
 Maybe he can help out.


----------



## i luvmusic 2

.


----------



## Paladin79

I do have a plan in mind to modify some existing headphones so they will be 250 ohms and work well with the Crack. Hopefully I will have enough variables so I can adjust the sound for my liking. Final cost, $50 plus labor. I hope I can make the modifications in four hours or less but right now it is a little tough to quantify.  When finished the headphones will look like they belong with the Crack amp I will be building.


----------



## Paladin79

Ok I received my 1/8 inch copper plate. It has a few scratches that will buff out but you can probably tell by the finger prints it is pure copper, not coated, precisely 6 inches by 10 inches. It weighs 2.6 lbs. This is not copper plated aluminum lol. Also it is freaking rigid, there is no problem with it supporting two tubes, and a small transformer once cut. Some of the scratches are a little deep for my liking but I plan to add a patina any way but it is certainly thick enough to buff down to a lustrous copper sheen if I wished. Then try to picture it with a bluish green patina against some dark oak (hopefully quartered oak, or even walnut.) I may strive for copper rivets holding brown bakelite tube sockets, attention to detail is important.


----------



## buke9

paladin79 said:


> Ok I received my 1/8 inch copper plate. It has a few scratches that will buff out but you can probably tell by the finger prints it is pure copper, not coated, precisely 6 inches by 10 inches. It weighs 2.6 lbs. This is not copper plated aluminum lol. Also it is freaking rigid, there is no problem with it supporting two tubes, and a small transformer once cut. Some of the scratches are a little deep for my liking but I plan to add a patina any way but it is certainly thick enough to buff down to a lustrous copper sheen if I wished. Then try to picture it with a bluish green patina against some dark oak (hopefully quartered oak, or even walnut.) I may strive for copper rivets holding brown bakelite tube sockets, attention to detail is important.


With patina that will be bitchin.


----------



## Paladin79

buke9 said:


> With patina that will be bitchin.


 
 it will hide some scratches too, and with a little chemistry the finish will only take one day and then I will clear coat it. I was definitely wrong in worrying about this bending.
  
 At least I know now if I use this thickness copper plate on the front and back of the amp, it will support switches, jacks, potentiometers, ac outlets and VU meters once I get my patterns figured out.


----------



## i luvmusic 2

My new tube for my CRACK i don't know tho if this Raytheon 6832 Sub miniature tube has been used with CRACK by someone else before me Anyway it sound darn good to my ears i just need to make a proper adapter to be safe so i don't touch any of those small exposed leads for now here it is.


----------



## ProfFalkin

You are a brave soul.


----------



## Paladin79

I guess changing the socket was out of the question for someone. Nice tube height though.


----------



## i luvmusic 2

That just for testing not for permanent use i do have the new adapter just waiting for it to dry.


----------



## Paladin79

i luvmusic 2 said:


> That just for testing not for permanent use i do have the new adapter just waiting for it to dry.


 
 Whew! Now I might sleep tonight.


----------



## i luvmusic 2

Here it is.


----------



## Paladin79

i luvmusic 2 said:


> Here it is.


 
 Omg I love it!!!!  I already have plans for copper usage on my Crack otherwise I might snag that idea.


----------



## i luvmusic 2

Go ahead....
	

	
	
		
		

		
			




  
 I think that is better than this one on the picture below.
 WARNING DON'T TRY THIS.


----------



## Paladin79

A more masterful use of Phoenix connectors have I rarely seen. At least if it goes up in some you can say they are trying to rise from the ashes.


----------



## i luvmusic 2

You can use a copper coupling/reducer for the case feet i thought about it long time ago just didn't try it yet.


----------



## i luvmusic 2

paladin79 said:


> A more masterful use of Phoenix connectors have I rarely seen. At least if it goes up in some you can say they are trying to rise from the ashes.


 
 It actually reminds of rocket launcher.


----------



## Paladin79

i luvmusic 2 said:


> You can use a copper coupling/reducer for the case feet i thought about it long time ago just didn't try it yet.


 
 Hmm I will consider that but mine will be steampunk, I am considering small claw feet or claw and ball if I can find them small enough. I am incorporating a bit of brass with a lot of copper, the VU meters should give it a 1920's look and they will be functional. Now for my headphone rack that matches, I am using copper pipe and a copper plate with patina over the whole thing. That will rest on a walnut or quartered oak base and go with the headphones I am modifying to 250 ohm. I am considering copper mesh over a jacketed star quad cable, it would look scary as hell but be quite safe. Maybe a miniature star quad to keep the weight down.


----------



## i luvmusic 2

paladin79 said:


> i luvmusic 2 said:
> 
> 
> > You can use a copper coupling/reducer for the case feet i thought about it long time ago just didn't try it yet.
> ...


 
 I'am drooling already,I love steampunk have alot of gauges,couplings pipes,wires etc etc etc that i can  use to build some steampunk lamps/headphone stand  i'am just suck at designing my own.


----------



## Paladin79

i luvmusic 2 said:


> I'am drooling already,I love steampunk have alot of gauges,couplings pipes,wires etc etc etc that i can  use to build some steampunk lamps/headphone stand  i'am just suck at designing my own.


 
 At least with a copper plate on top, I will be able to solder to it most anywhere I want and that will help with some additional things I will do on top. If you read much, read Angelmaker by Nick Harkaway, great steampunk novel.
  
 Anyway I will try to post pictures as I work on the amp. The electronics is easy for me so I want to spend my energy on the cosmetics. I already have employees involved who will offer advice on the woodworking and such. I want someone who uses a router a lot more than me to make sure my copper plates fit well. So far I will be using three.


----------



## Timoteo80

Wow this has gotten VERY interesting!! Seeing designs like this trip me out, in a good way tho haha. What tube are you using up front? I'm just curious, why go they all that effort to have a different tube from the stock 12au7? What sonic difference is there? Thx for posting I'm loving it.


----------



## Charles L

Doc B.
  
 Would you take a look at the power transformer? Is this original bottlehead? 
  
http://i.ebayimg.com/images/g/2VwAAOSwax5Ywtfz/s-l1600.jpg
  
  
 Thanks.
  
 Dr. L


----------



## i luvmusic 2

The tube is Raytheon 6832 sub miniature tube the sound of this tube to my ears is similar to 6SN7 smooth and none fatiguing i have this tube few years ago for my littledot MK III and last night i found it in the box where i put all the tubes that i used for my MK III so i decided to try it with the crack and turned out well for me sound quieter than some of my 6SN7 with adapters the way i made the adapter for this 6832 i just solder it directly to a 9 pin socket with 3 layers of heat shrink tubing then i used a JB WELD to attach the socket/tube to the copper reducer it's not hard to do at all.If i remember correctly i paid a dollar and change per tube few years ago but now they go for $10 per tube.


----------



## Paladin79

If you do not mind me asking, you have four screw heads around that front tube socket. On a lot of the Cracks I see two empty holes. Are the four screws (bolts) used for the tube socket or other upgrades?


----------



## i luvmusic 2

paladin79 said:


> If you do not mind me asking, you have four screw heads around that front tube socket. On a lot of the Cracks I see two empty holes. Are the four screws (bolts) used for the tube socket or other upgrades?


 
 Two for the socket and two for the Speedball.


----------



## Paladin79

i luvmusic 2 said:


> Two for the socket and two for the Speedball.


 
 That makes sense, and therefore some of the amps I have seen lack the upgrade. Looks like I will be drilling four holes in my copper plate then and I will be trying for copper rivets. Some ugly things can happen when you use dissimilar metals so I like to play it safe.


----------



## i luvmusic 2

In a few minutes i will show you more screws on the top plate for some other upgrades like 2 FILM CAPS and for the DIODES some people used adhesive to hold the film caps i just don't trust the adhesive due to the high heat created by the amp that is why i just drilled those holes and used screws so many ways you can attach those upgrades but this is how i did mine.


----------



## Paladin79

i luvmusic 2 said:


> In a few minutes i will show you more screws on the top plate for some other upgrades like 2 FILM CAPS and for the DIODES some people used adhesive to hold the film caps i just don't trust the adhesive due to the high heat created by the amp that is why i just drilled those holes and used screws so many ways you can attach those upgrades but this is how i did mine.


 

 I am increasing the height of my cabinet so I can include VU meters. I will have four inch copper plates on front and back so it is feasible I can attach to the back plate if need be and I will have extra room besides so I will have some flexibility on changing out parts.  I am hoping to limit my openings in the top plate but every now and then I may still have to drill a couple holes.


----------



## i luvmusic 2

Noticed the 4 screws on the plate by the transformer the 2 on the side of the tranny is for the diodes and the 2 in front of the tranny is for the film caps now at least you can decide how would you like to attach those upgrades if you ever decide to do them.I hope you make those plate larger and the box taller so you have more room to install those upgrades,Hope this help.
 These are old photos.


----------



## i luvmusic 2

paladin79 said:


> i luvmusic 2 said:
> 
> 
> > In a few minutes i will show you more screws on the top plate for some other upgrades like 2 FILM CAPS and for the DIODES some people used adhesive to hold the film caps i just don't trust the adhesive due to the high heat created by the amp that is why i just drilled those holes and used screws so many ways you can attach those upgrades but this is how i did mine.
> ...


 
 Ooops! late reply.


----------



## Paladin79

i luvmusic 2 said:


> Ooops! late reply.


 

 Np, those caps do take up some space. I will have some plugs and jacks in mine because I am pulling things off the top plate and I will need to be able to access any portion of the electronics for upgrades. My on off switch will be on the front and I hope to not have any wires poking out of the top of the plate.


----------



## i luvmusic 2

If i'am going to do it all over again i will definitely make everything larger.


----------



## i luvmusic 2

paladin79 said:


> i luvmusic 2 said:
> 
> 
> > Ooops! late reply.
> ...


 
 more space you will need for the choke,bypass caps,attenuator maybe more film cap/s or bypass cap for the power supply.Be careful re-routing those wirings you may encounter some HUM issue.


----------



## Paladin79

i luvmusic 2 said:


> more space you will need for the choke,bypass caps,attenuator maybe more film cap/s or bypass cap for the power supply.Be careful re-routing those wirings you may encounter some HUM issue.


 
 I will more than likely use shielded wires when I do reroute some of them. The electronics is the easy part for me, getting the esthetics right for my vision will be the tricky part.
  
  If I upgrade much I will definitely want to upgrade my headphones, I am just modifying some with 250 ohm drivers to get by until I catch a deal on some high end ones. I have not read much of this thread but I seem to recall saying that with changing some of the capacitors you are more likely to need 600 ohm headphones.  I can put those drivers in as well but they are not cheap.


----------



## Doc B.

charles l said:


> Doc B.
> 
> Would you take a look at the power transformer? Is this original bottlehead?
> 
> ...


 
 Looks like the power transformer is stock. So I will presume you are asking about that little choke that has been hung under the stock through-chassis mounted power transformer. Very important first thing -
  
 if it says MADE IN CHINA, it's not a Bottlehead transformer. Bottlehead transformers and inductors are made in the Democratic People's Republic of Kalifornia (aka North Kalifornia). And they have Bottlehead printed on the label. We design them ourselves, working with the winder. 
  
 Secondly that's a choke, not a transformer, that someone added. Not stock. Not supported by Bottlehead. Presumably added in the power supply. Not, in my opinion, worth the trouble. Whoever built it will probably argue that the Crack is much better when you add $750 worth of extra boutique parts. I will argue that you will be better off stepping up to a Crackatwoa at that point, which actually improves the design, not just the parts brands.


----------



## i luvmusic 2

AMEN! i dropped a little bit of my hard earned $$$ for the upgrades and some are NOT WORTH THE MONEY,Sorry folks!


----------



## Charles L

thanks. Doc. B. That's very prompt and thorough answer. Thumbs up.
  
 By the way, I assume you count Wa as part of Democratic People's Republic of Kalifornia? 
	

	
	
		
		

		
			




  
 Cheers!
  
 Dr. L


----------



## Paladin79

I did not catch the sale date for the Crack. I assume it is over, now my son wants one, I should have grabbed two when I had the chance.
  
 My son is interested in my cabinet upgrades. They will either be wonderful or suck, probably no in between. It is how I play ping pong, every shot is either a winner or some innocent bystander gets smacked in the derriere by an extremely wild miss. One way or the other, the ball is not going back and forth over the net a lot.


----------



## Allanmarcus

i luvmusic 2 said:


> Noticed the 4 screws on the plate by the transformer the 2 on the side of the tranny is for the diodes and the 2 in front of the tranny is for the film caps now at least you can decide how would you like to attach those upgrades if you ever decide to do them.I hope you make those plate larger and the box taller so you have more room to install those upgrades,Hope this help.
> These are old photos.


 
  
 I think you should try some large caps. Those look wimpy!


----------



## Paladin79

I am definitely going with a taller box. In effect I will have three plates, all at the same ground potential. It is taking me a while to get all the parts together but it probably took me a total of ten minutes to envision the design. The electronic build might take me six hours but the cosmetics will take longer. I am starting with a 1.37 inch diameter solid copper rod for volume knob and switch housing. And being a Gemini, I do things in twos, so I will build two amps.


----------



## Charles L

Dear Doc. B.
  
 Do you still provide any service for a s.e.x 2.1? how much?
  
 Thx.
  
 Dr. L


----------



## adydula

i luvmusic 2,
  
 Might I ask which ones are worth the money and which ones are not in you opinion??
  
 Thanks,
 Alex


----------



## i luvmusic 2

allanmarcus said:


> i luvmusic 2 said:
> 
> 
> > Noticed the 4 screws on the plate by the transformer the 2 on the side of the tranny is for the diodes and the 2 in front of the tranny is for the film caps now at least you can decide how would you like to attach those upgrades if you ever decide to do them.I hope you make those plate larger and the box taller so you have more room to install those upgrades,Hope this help.
> ...


 
 NO THANKS!Those Caps are just wimpy MUNDORF let me guess you used DUELAND.


----------



## i luvmusic 2

adydula said:


> i luvmusic 2,
> 
> Might I ask which ones are worth the money and which ones are not in you opinion??
> 
> ...


 
  I would say the Speedball,Volume Pot and the Cree Diode.Which ones are not?You be the judge and if you will asked me about  that caps to my ears for what i paid for them including the bypass caps not worth my $$$.


----------



## JamieMcC

When looking at caps consider the Russian MGBO paper in oil capacitors for the outputs caps, I've seen a couple of Cracks with them now. I used them with a russian teflon bypass they were a superb combo with my Beyer T1's and ousted a pair of expensive 100uf Mundorfs.
  
 Six 30uf 160v capacitors like the ones in the link will set you back about $10 + shipping but you need to get creative fitting them in.
  
 http://www.ebay.co.uk/itm/30-uF-160-V-LOT-OF-2-RUSSIAN-PAPER-PIO-AUDIO-CAPACITORS-MBGO-2-/272564648176?hash=item3f761e78f0:g:KeUAAOSwCU1YtLNE


----------



## adydula

I am totally happy with the Crack with its speedball constant current design...I agree with Doc, its more the design of the circuit than all the extra stuff...not trying to take away any fun of modding your Crack..have at it.
  
 I would rather spend the bucks on a Mainline or new headhpones!! or some NOS Beer!! LOL!
  
 Alex


----------



## JamieMcC

adydula said:


> I am totally happy with the Crack with its speedball constant current design...I agree with Doc, its more the design of the circuit than all the extra stuff...not trying to take away any fun of modding your Crack..have at it.
> 
> I would rather spend the bucks on a Mainline or new headhpones!! or some NOS Beer!! LOL!
> 
> Alex


 
  
 The way the premium tube prices have been going up it is certainly very easy to spend a small fortune on hot rodding up your Crack. But on the other hand it is a hell of a lot of fun and can give hours of enjoyment and of course can be done piece meal. I am positive that if I hadn't done the Crack I would never have had the confidence to build a Sex, Mainline or Eros myself with no prior build experience, hats off to those who do..
  
 But if you have deep pockets I can honestly say the Mainline is seriously good!


----------



## ProfFalkin

jamiemcc said:


> The way the premium tube prices have been going up it is certainly very easy to spend a small fortune on hot rodding up your Crack. But on the other hand it is a hell of a lot of fun and can give hours of enjoyment and of course can be done piece meal. I am positive that if I hadn't done the Crack I would never have had the confidence to build a Sex, Mainline or Eros myself with no prior build experience, hats off to those who do..
> 
> But if you have deep pockets I can honestly say the Mainline is seriously good!



I thought pot was a gateway drug... Looks like we have progressed to Crack.

About the Mainline, have you heard other amps in it's price range and how would you compare them?


----------



## neddoge

Which pot is everybody using in their Crack over the stock version?  I've heard of a 100k Blue Velvet and a Valeb stepped ladder.


----------



## Allanmarcus

neddoge said:


> Which pot is everybody using in their Crack over the stock version?  I've heard of a 100k Blue Velvet and a Valeb stepped ladder.




I use this alps pot. Made a significant improvement and cost $11

http://www.ebay.com/itm/Japan-ALPS-RK27-VOLUME-Potentiometer-Dual-100K-100KAX2-Slotted-/320816794126


----------



## Paladin79

allanmarcus said:


> I use this alps pot. Make a significant improvement and cost $11
> 
> http://www.ebay.com/itm/Japan-ALPS-RK27-VOLUME-Potentiometer-Dual-100K-100KAX2-Slotted-/320816794126


 
 I have always had great success with Alps and they would be my brand of choice as well.


----------



## neddoge

paladin79 said:


> I have always had great success with Alps and they would be my brand of choice as well.


 
  
  


allanmarcus said:


> I use this alps pot. Made a significant improvement and cost $11
> 
> http://www.ebay.com/itm/Japan-ALPS-RK27-VOLUME-Potentiometer-Dual-100K-100KAX2-Slotted-/320816794126


 
 Thanks for the input Allan, Tom.
  
 http://www.ebay.com/itm/302245653411
  
 Any thoughts on this pot as well?  I had the Alps referenced above in my cart as well for comparison.


----------



## kxanthop

neddoge said:


> Thanks for the input Allan, Tom.
> 
> http://www.ebay.com/itm/302245653411
> 
> Any thoughts on this pot as well?  I had the Alps referenced above in my cart as well for comparison.



Are these 100% compatible with the Crack, especially physically wise? It's been quite a while since i assembled the Crack, is it only two cables that need soldering? Many thanks!


----------



## Paladin79

kxanthop said:


> Are these 100% compatible with the Crack, especially physically wise? It's been quite a while since i assembled the Crack, is it only two cables that need soldering? Many thanks!


 

 I have not received my Crack yet, I downloaded the PDF's but have not had a lot of time to look at them. I have a feeling if you search the Bottlehead website or even this thread you will find people talking about various pots they have used. I could talk in general about potentiometers and rheostats but that is not going to answer specific questions. After value and wattage rating, the best info might be from folks who have tried specific volume pots. There are a couple ways you can approach such a build, someone tells you were to solder a red wire and a white wire or you can learn how another brand of product hooks up and how a potentiometer works. I always found it more fun to do some research and learn something and there is plenty of info out there on the Cracks.


----------



## neddoge

kxanthop said:


> Are these 100% compatible with the Crack, especially physically wise? It's been quite a while since i assembled the Crack, is it only two cables that need soldering? Many thanks!


 

 ​There was a user on Reddit that used this pot specifically, despite its peculiar size and solder points.  I'm still working through this thread for feedback, but I'll probably go with the ALPS above.


----------



## Paladin79

neddoge said:


> ​There was a user on Reddit that used this pot specifically, despite its peculiar size and solder points.  I'm still working through this thread for feedback, but I'll probably go with the ALPS above.


 

 There have been a lot of people doing mods on this amp for some time so I am sure the info is out there. What will be tricky is knowing the exact difference a $75 pot might  make compared to a $12.00 pot, you will see some Alps configured the same way with stepped resistors but they can be pretty pricey.


----------



## Allanmarcus

neddoge said:


> paladin79 said:
> 
> 
> > I have always had great success with Alps and they would be my brand of choice as well.
> ...


 

 yes that will work
  
 note, for the alps pot I recommended, I think I had to make some minor mods to the plate. It was easy with a drill, but just saying.


----------



## ProfFalkin

paladin79 said:


> I have not received my Crack yet, I downloaded the PDF's but have not had a lot of time to look at them. I have a feeling if you search the Bottlehead website or even this thread you will find people talking about various pots they have used. I could talk in general about potentiometers and rheostats but that is not going to answer specific questions. After value and wattage rating, the best info might be from folks who have tried specific volume pots. There are a couple ways you can approach such a build, someone tells you were to solder a red wire and a white wire or you can learn how another brand of product hooks up and how a potentiometer works. I always found it more fun to do some research and learn something and there is plenty of info out there on the Cracks.




I agree. I have not received my Crack yet either. For the low price of the Alps pot - being a known and well trusted manufacturer around here - I picked one up. 

Sure, ladder type pots should provide a better signal path and constant impedance, but I've never heard of the maker of the one that was linked which seems to be cheap-fi ebay stuff, and I'd rather stick with a known quantity. 

Also, consider what you're sticking it into. Sure, the Crack is a good amp, but I'd argue putting a well known attenuator like the Khozmo or Audio Note into it would be overkill. Spend that cash on a Crackatwo, imo.


----------



## adydula

Now thats a good conclusion!

A.
:>)


----------



## Paladin79

I may build my son one so it would allow me to have one to compare to the custom Crack I will build. For a while I would be able to switch between them to compare the sound and know how much difference a pot, or capacitors will make. If the change is significant, I will know to do the same upgrades to his. If I catch a deal on a completed one that has had some upgrades I will work toward getting my build to the same level.


----------



## Allanmarcus

paladin79 said:


> I may build my son one so it would allow me to have one to compare to the custom Crack I will build. For a while I would be able to switch between them to compare the sound and know how much difference a pot, or capacitors will make. If the change is significant, I will know to do the same upgrades to his. If I catch a deal on a completed one that has had some upgrades I will work toward getting my build to the same level.


 

 I borrowed a friend's fully pimped out crack with all the giant caps and choke and unobtanium everything, and compared it to my mostly stock crack, and guess what, they sound the same (with the similar tubes) to me. Like I've said, I'm lucky that I can't hear these very subtle differences that so many _claim_ to be able to hear. Either than, or their really isn't as much a difference in sound as many claim. Or there isn't that much a difference in sound for the music I listen to.


----------



## Paladin79

allanmarcus said:


> I borrowed a friend's fully pimped out crack with all the giant caps and choke and unobtanium everything, and compared it to my mostly stock crack, and guess what, they sound the same (with the similar tubes) to me. Like I've said, I'm lucky that I can't hear these very subtle differences that so many _claim_ to be able to hear. Either than, or their really isn't as much a difference in sound as many claim. Or there isn't that much a difference in sound for the music I listen to.


 

 That is good to know, my son is fully capable of pimping his down the road but time is always a factor for him. I just saw a non working one on Ebay for $350 opening bid lol, it claimed it had the speedball upgrade but sure did not show in the photo as best I could tell. If I can catch one for $300 used with speedball I will probably snag it just to save me a little time as I do my own build. For the next month or so I may be on electronics all weekend anyway and I am anxious to build my own amp.  Monday I have 6 more pieces of 1/8 inch copper plate arriving and bakelite sockets and inch and a half copper rod. My wife is fine with this build, a giant tesla coil with bucket capacitors makes this look so tame. Everything is relative.
  
 Some of the Chesky stuff I listen to, there are a lot of subtle little noises that come through that lend to the appeal. Slight nuances.


----------



## kxanthop

paladin79 said:


> I have not received my Crack yet, I downloaded the PDF's but have not had a lot of time to look at them. I have a feeling if you search the Bottlehead website or even this thread you will find people talking about various pots they have used. I could talk in general about potentiometers and rheostats but that is not going to answer specific questions. After value and wattage rating, the best info might be from folks who have tried specific volume pots. There are a couple ways you can approach such a build, someone tells you were to solder a red wire and a white wire or you can learn how another brand of product hooks up and how a potentiometer works. I always found it more fun to do some research and learn something and there is plenty of info out there on the Cracks.





paladin79 said:


> I have not received my Crack yet, I downloaded the PDF's but have not had a lot of time to look at them. I have a feeling if you search the Bottlehead website or even this thread you will find people talking about various pots they have used. I could talk in general about potentiometers and rheostats but that is not going to answer specific questions. After value and wattage rating, the best info might be from folks who have tried specific volume pots. There are a couple ways you can approach such a build, someone tells you were to solder a red wire and a white wire or you can learn how another brand of product hooks up and how a potentiometer works. I always found it more fun to do some research and learn something and there is plenty of info out there on the Cracks.







neddoge said:


> ​There was a user on Reddit that used this pot specifically, despite its peculiar size and solder points.  I'm still working through this thread for feedback, but I'll probably go with the ALPS above.




Many thanks!
I think i will go for the Alps!


----------



## i luvmusic 2

Alps Blue Velvet they do sound good for the money i really like mine.


----------



## Paladin79

Right now I a spending more on cosmetics, just purchased enough quartered oak for two cabinets so most everything I will do on the outside is covered. I might even use hinges so the tops tilt up and lock in place but that idea is still on the drawing board.
  
 I did order a blue velvet to check out. Anything reminiscent of a David Lynch film should be good.
  
 Tom


----------



## adydula

Allanmarcus,

That has been my experience as well....the upgrades that modders do are "neat" and look cool, but in reality there isnt much of a real world sonic difference to my ears....but having a well made stepped vol pot is a nice mechanical thing and the low volume area of the pot that many pots have tracking issues with may be much better...this is a nice thing.

Even though 99% of the time we dont listen at these low volume levels.

The basic Crack circuit and the speedball is the magic here....BH has done a nice job in its design and simplicity.

Alex


----------



## Paladin79

adydula said:


> Allanmarcus,
> 
> That has been my experience as well....the upgrades that modders do are "neat" and look cool, but in reality there isnt much of a real world sonic difference to my ears....but having a well made stepped vol pot is a nice mechanical thing and the low volume area of the pot that many pots have tracking issues with may be much better...this is a nice thing.
> 
> ...


 
 It is really good to get info like that. I have yet to see one up close so I respect most any comment about the amp. I should know this but it has been a while since I studied it but audio taper pots are logrithmic as opposed to linear where half way down the pot would be half the resistance. I am sure there is some variance between brands and types on how that taper is set up. Ladder type pots might offer more variables on that range but that is just a hunch. It is obvious there is a fixed resistance when switching between said resistors.
  
 I do not mean to butt in, I am in the process of building 300-400 audio cables this weekend and need a break from time to time. So far the only electronic components I have ordered for my amp is the Blue Velvet pot, some bakelite tube sockets, and I will be upgrading the headphone jack. The sockets and jack will not make an audible change, I am thinking more of longevity on the jack and I am going old school look on the tube sockets.


----------



## Allanmarcus

adydula said:


> Allanmarcus,
> 
> That has been my experience as well....the upgrades that modders do are "neat" and look cool, but in reality there isnt much of a real world sonic difference to my ears....but having a well made stepped vol pot is a nice mechanical thing and the low volume area of the pot that many pots have tracking issues with may be much better...this is a nice thing.
> 
> ...




The low volume issue is the main reason I got the blue velvet. Works well at low volume.


----------



## Paladin79

allanmarcus said:


> The low volume issue is the main reason I got the blue velvet. Works well at low volume.


 
 Very cool. Allan is very down to earth and were I to buy a working Crack as well as building my own I would certainly trust his workmanship and component choices. Time can be a factor for me. 
  
 The large cat in my avatar is trying to help me with cables right now. He is a lot of help provided I want teeth marks in the pvc jackets.
  
 It is not a sonic improvement but since I am installing dual VU meters, I will more than likely install dual Blue Velvet volume pots once I check one out. Having the extra plate on the front and more room gives me more choices.


----------



## Paladin79

I now have all the copper needed for the cabinets on two Cracks. Enough copper rod for control knobs. My wife came in carrying the mail and asked if I was buying bricks.


----------



## ProfFalkin

Getting into the commodities business, eh?


----------



## Paladin79

Quote: 





proffalkin said:


> Getting into the commodities business, eh?


 
 I sold my gold when it was at an all time high so I invested in copper lol. The knobs may have to be hollowed out a bit, I do not want the amp tipping forward from the weight. I want individual volume pots for right and left channel, I may mount an on off switch on the left hand side of the cabinet and the headphone jack on the right. I may have them on small plates inset into the wood, copper plates naturally. The electronics is fairly easy for me so I am concentrating on the cabinet build. I intend for it to sound good of course and I will have extra room for adding future updates. The vu meters and volume knobs for each channel should be pretty close to the same size, mind you there will be a green patina on the copper, all cables and headphones will look steam punk if everything works out.


----------



## Tom-s

paladin79 said:


> I will more than likely install dual Blue Velvet volume pots once I check one out.


 
  
 On the BH forum's i've seen the experienced builders vote against this option. 
 BH once had a foreplay with dual volume control. Using a separate volume control on each channel could be a PITA for adjustment..


----------



## Allanmarcus

tom-s said:


> paladin79 said:
> 
> 
> > I will more than likely install dual Blue Velvet volume pots once I check one out.
> ...


 

 The Koss ESP-950 has dual adjustment. It's not horrible, but it would be much better to have a balance and a volume, or even better, no need for balance and just a volume (you know, like the Crack has


----------



## Paladin79

tom-s said:


> On the BH forum's i've seen the experienced builders vote against this option.
> BH once had a foreplay with dual volume control. Using a separate volume control on each channel could be a PITA for adjustment..


 
 I may test single as well as dual. I have the option on a couple amps I like real well and they have never given me any issues as far as adjustment. I am not exactly a novice builder by any stretch of the imagination. Dual VU meters will give me a good visual representation as well. There are several pieces of music I can think of where I would like to bring up one channel slightly in respect to the other so I prefer having that ability. Each to their own. I am not a fan of balance controls, I will go dual controls, one for each channel. A copper plate with copper knobs might be a bit much so I may go with something with more of a contrast such as this on one amp I build. Antique bakelite will match the sockets I am using.
  
  
 Tom


----------



## Timoteo80

paladin79 said:


> If you do not mind me asking, you have four screw heads around that front tube socket. On a lot of the Cracks I see two empty holes. Are the four screws (bolts) used for the tube socket or other upgrades?




Thank you for asking that. Been wondering that myself! My Crack is stock & I have two empty holes. I see others with 4 screw heads & wondered why mine had 2 open haha. NOW I get it! My Speedball upgrade is sitting here waiting to be installed but I haven't felt the need yet. It's that good.


----------



## Paladin79

timoteo80 said:


> Thank you for asking that. Been wondering that myself! My Crack is stock & I have two empty holes. I see others with 4 screw heads & wondered why mine had 2 open haha. NOW I get it! My Speedball upgrade is sitting here waiting to be installed but I haven't felt the need yet. It's that good.


 

 That is good to know about the sound without the upgrade. I will be putting those four holes in my top plate, holes for tube sockets and transformer but that should be about it I hope.
  
 Anyone know of much difference between the 1.0 crack and the 1.1? I may be buying a couple of these and want to have an idea about versions.


----------



## Timoteo80

paladin79 said:


> That is good to know about the sound without the upgrade. I will be putting those four holes in my top plate, holes for tube sockets and transformer but that should be about it I hope.
> 
> Anyone know of much difference between the 1.0 crack and the 1.1? I may be buying a couple of these and want to have an idea about versions.




I highly recommend you build yours stock first. Listen, enjoy & SB it later. BH actually recommends this approach too. This way if you need to trouble shoot anything upon initial start up you won't have to remove the SB & go to stock to do the troubleshooting. A LOT less hassle. Plus you get to get used to the stock sound & really hear what the SB upgrade does to the Crack. It's a BEAUTIFUL amp in my opinion, both looks & definitely sound!! I'll never sell my Crack! -insert crude joke here-lol


----------



## Allanmarcus

paladin79 said:


> timoteo80 said:
> 
> 
> > Thank you for asking that. Been wondering that myself! My Crack is stock & I have two empty holes. I see others with 4 screw heads & wondered why mine had 2 open haha. NOW I get it! My Speedball upgrade is sitting here waiting to be installed but I haven't felt the need yet. It's that good.
> ...


 

 I think the difference is the universal voltage transformer and a better manual.


----------



## Timoteo80

Correct 





allanmarcus said:


> I think the difference is the universal voltage transformer.




Correct!


----------



## Paladin79

timoteo80 said:


> Correct
> Correct!


 

 Oh good well I have a 1.1 on the way and if I buy a 1.0 from someone in the states I should be safe. I could have looked that up myself but I had a feeling it was a pretty easy question for you folks. Now that I was planning to build two of the Cracks my son may want a higher end headphone amp from Bottlehead so I may be building something else as well. My time is less valuable and I am faster so it makes sense to me.


----------



## neddoge

allanmarcus said:


> yes that will work
> 
> note, for the alps pot I recommended, I think I had to make some minor mods to the plate. It was easy with a drill, but just saying.


 

 ​Do you recall roughly what mods were needed?  How much of a PITA is it to install the stock pot, and then upgrade the pot when I upgrade the speedball mod?


----------



## buke9

Going to build my new one straight stock and after checks go straight to the SB so I'll be able to a/b them after I'm done. I bought the SB to put in the old one but then Bottlehead had the sale so I'm glad I waited. Still waiting on LED's to fix the old one. I hope to get it once I get back from vacation to CanJam SoCal so I should be inspired to get it done pretty quick.


----------



## Allanmarcus

neddoge said:


> allanmarcus said:
> 
> 
> > yes that will work
> ...


 

 The depends. I took the opportunity to replace the twisted three wires that come from the RCA connectors to the POT with two shielded wires. The issue with a replacement pot is the length of the wires from the RCA connectors to the POT. The big-ass pots might require slightly longer wire. Very easy to make a wire shorter; much harder to make is longer! The good news is you can purchase shielded 24AWG wire from markertek.com by the foot for under $1 a foot, so replacing the wire, if you have to, will only cost a few bucks.
  
 As for the mods to the plate, they were easy with a round file or a drill. I just had to enlarge a hole a little. If you don't have a file or file set, this will be your opportunity to get one! You don't need to spend a ton; harbor freight probably has a set for a few bucks.


----------



## Paladin79

buke9 said:


> Going to build my new one straight stock and after checks go straight to the SB so I'll be able to a/b them after I'm done. I bought the SB to put in the old one but then Bottlehead had the sale so I'm glad I waited. Still waiting on LED's to fix the old one. I hope to get it once I get back from vacation to CanJam SoCal so I should be inspired to get it done pretty quick.


 
 Once I see a kit I can probably help with LED's, I have an assortment left over from test equipment builds. If my son decides to move up to a Mainline or such I should have plenty of copper and such left over after I build a Crack. I normally buy things in two's anyway and I doubt some of the items will fit the other build.


----------



## Allanmarcus

paladin79 said:


> buke9 said:
> 
> 
> > Going to build my new one straight stock and after checks go straight to the SB so I'll be able to a/b them after I'm done. I bought the SB to put in the old one but then Bottlehead had the sale so I'm glad I waited. Still waiting on LED's to fix the old one. I hope to get it once I get back from vacation to CanJam SoCal so I should be inspired to get it done pretty quick.
> ...


 

 The LEDs are very very specific. There is discussion on these on the BH Crack forum.


----------



## Paladin79

allanmarcus said:


> The LEDs are very very specific. There is discussion on these on the BH Crack forum.


 
 Interesting. I may have to look that one up, now I am curious.


----------



## Paladin79

allanmarcus said:


> The depends. I took the opportunity to replace the twisted three wires that come from the RCA connectors to the POT with two shielded wires. The issue with a replacement pot is the length of the wires from the RCA connectors to the POT. The big-ass pots might require slightly longer wire. Very easy to make a wire shorter; much harder to make is longer! The good news is you can purchase shielded 24AWG wire from markertek.com by the foot for under $1 a foot, so replacing the wire, if you have to, will only cost a few bucks.
> 
> As for the mods to the plate, they were easy with a round file or a drill. I just had to enlarge a hole a little. If you don't have a file or file set, this will be your opportunity to get one! You don't need to spend a ton; harbor freight probably has a set for a few bucks.


 
 One of the first changes I was going to make were the three twisted wires, now I wish I had included some with the coaxial cable I sent Neddoge. I am using two pots anyway since I will run dual pots as well as replacing the quarter inch jack. I really should look at the PDF for this amp sometime but I still have a bit of a wait for the kit.


----------



## buke9

I ordered 5 leds when I bought the new Crack so I guess they will arrive together.


----------



## Paladin79

buke9 said:


> I ordered 5 leds when I bought the new Crack so I guess they will arrive together.


 

 ​hlmp 6000 through hole poly dome red made by Broadcom perhaps? I will know more when I see one.


----------



## Allanmarcus

paladin79 said:


> allanmarcus said:
> 
> 
> > The LEDs are very very specific. There is discussion on these on the BH Crack forum.
> ...


 
 http://bottlehead.com/smf/index.php?topic=8977.0


----------



## Paladin79

allanmarcus said:


> http://bottlehead.com/smf/index.php?topic=8977.0


 
 That is certainly what I read them to be, I was not saying to throw any LED in there, I have a large selection and have used that part before but I may have to look around a bit. I should tell you, the last time I hired someone to organize my shop, he took one look at it and told me he would need a team. I have some parts, not so much copper plate, I had to order that, but electronic parts I have.


----------



## buke9

paladin79 said:


> That is certainly what I read them to be, I was not saying to throw any LED in there, I have a large selection and have used that part before but I may have to look around a bit. I should tell you, the last time I hired someone to organize my shop, he took one look at it and told me he would need a team. I have some parts, not so much copper plate, I had to order that, but electronic parts I have.


Not a big deal they are on order and I have many headphones and amps to keep me busy till then ; )


----------



## Paladin79

buke9 said:


> Not a big deal they are on order and I have many headphones and amps to keep me busy till then ; )


 
 Ok it could take me a while to find them honestly. I can order as many as 1300 and have them in a couple days but searching my shop is another matter lol. No disrespect to anyone building a Crack of course or working with electronics for the first time.
  
 The area I live in used to be a hotbed for electronics. It always saddened me to go to a garage sale and see cabinets of electronic parts that used to mean something to someone and the widow selling them off. If I have something, and I can help, I offer it. I cannot recall if I sent you anything Buke but I have with Alanmarkus, and Neddoge and others on here; it is just how I think.
  
 As I said before I am more interested in the cosmetics, the electronics you may not recognize much when I am done but the metallurgy, the chemistry, and the physics are what interest me about this project.


----------



## buke9

paladin79 said:


> Ok it could take me a while to find them honestly. I can order as many as 1300 and have them in a couple days but searching my shop is another matter lol. No disrespect to anyone building a Crack of course or working with electronics for the first time.
> 
> The area I live in used to be a hotbed for electronics. It always saddened me to go to a garage sale and see cabinets of electronic parts that used to mean something to someone and the widow selling them off. If I have something, and I can help, I offer it. I cannot recall if I sent you anything Buke but I have with Alanmarkus, and Neddoge and others on here; it is just how I think.
> 
> As I said before I am more interested in the cosmetics, the electronics you may not recognize much when I am done but the metallurgy, the chemistry, and the physics are what interest me about this project.


You sent me some wire that I have yet to utilize. I still am working on some Walnut for you it just seems too much gets in the way to do it. I'm going to try to do it this week. The largest width I can do is 6 inches. I'll try and plane some for you to check out. I have to break out some that I have not seen as they are rough cut and different thickness. I will get back to you.


----------



## Paladin79

buke9 said:


> You sent me some wire that I have yet to utilize. I still am working on some Walnut for you it just seems too much gets in the way to do it. I'm going to try to do it this week. The largest width I can do is 6 inches. I'll try and plane some for you to check out. I have to break out some that I have not seen as they are rough cut and different thickness. I will get back to you.


 
 not a problem either way. I can work with six inches or if need be I have access to a planer that will handle as wide as 12. I have a couple employees who do some woodworking and I will enlist their help as needed. The copper knobs are a bigger issue, if those do not work out I will use antique bakelite. I am using 4 inch by 4 inch plates on front and back. The front plate will have two vu meters and dual volume knobs. There are some Chesky recordings where I would love to tweak the right channel just a bit, maybe my hearing is less on that side but it is usually high frequencies that I do not pick up like I should. Once I figure out which amp my son wants, I will know more about how many extra parts I have lol. I do believe I can lay my hands on 1/8 inch 6x10 copper plates whenever I want so that is easy.


----------



## Paladin79

Here is the fit for the drivers of the headphones I am modding for use with the Crack. These are 250 ohm but once I know this works and sounds the way I want I will most likely mod some for 600 ohm. I thought the fit would be close but this is way better than I hoped. When completed they should sound a little like Beyerdynamic.


----------



## Paladin79

How easy is it to sell a Crack once completed? I would think a lot of the joy is building it yourself. I may end up with an extra one but it should be customized with a cabinet upgrade and copper plates and such.


----------



## deserat

paladin79 said:


> How easy is it to sell a Crack once completed? I would think a lot of the joy is building it yourself. I may end up with an extra one but it should be customized with a cabinet upgrade and copper plates and such.


 
  
 The stock ones go pretty quick on ebay, though there are alot of 'em right now. Adding artistic flare as you are talking about could increase the price but require the right buyer, and as such make it a longer turn around. It's a pretty popular amp and there alot of people who simply don't want to build it ( so sad for them ).


----------



## buke9

paladin79 said:


> How easy is it to sell a Crack once completed? I would think a lot of the joy is building it yourself. I may end up with an extra one but it should be customized with a cabinet upgrade and copper plates and such.


It will sell quick as long as your under $400 it is gone.


----------



## Paladin79

buke9 said:


> It will sell quick as long as your under $400 it is gone.


 I doubt I will do VU meters and dual volume controls on the one I sell so under $400 should be doable perhaps.


----------



## TeeReQs

I'm still waiting for mine to ship. I probably shouldn't have waited until the last night of the sale to order. No hurry though. Plenty of other projects to do! Just found the shipping status page on their website though. Getting closer!


----------



## Paladin79

deserat said:


> The stock ones go pretty quick on ebay, though there are alot of 'em right now. Adding artistic flare as you are talking about could increase the price but require the right buyer, and as such make it a longer turn around. It's a pretty popular amp and there alot of people who simply don't want to build it ( so sad for them ).


 This is a very thought out answer. I have seen basic ones fetch $450 to $500 but some have extra tubes. Hopefully a quartered oak furniture grade cabinet and copper helps but just cause I like the idea does not mean everyone will.

If I do not end up with an extra amp I may just sell the cabinet ready to go for someone to upgrade their kit or finished amp.


----------



## i luvmusic 2

For a while i've been using 6CG7 for my CRACK and i got tired of some 6CG7 tubes will hum with my crappy DIY adapter so i decided to put a switch between Pin 4 and Pin 9 i'am surprised how quiet those same 6CG7 that hum on my adapter.
  
  
 Sorry for the crappy phone camera.


----------



## Paladin79

i luvmusic 2 said:


> For a while i've been using 6CG7 for my CRACK and i got tired of some 6CG7 tubes will hum with my crappy DIY adapter so i decided to put a switch between Pin 4 and Pin 9 i'am surprised how quiet those same 6CG7 that hum on my adapter.
> 
> 
> Sorry for the crappy phone camera.


 
 Those are decent enough photos. I look forward to experimenting with various tubes to find those I like best and thankfully there is plenty of info out there describing what others have tried. The biasing LED is pretty obvious in the photo.
  
 I must have ordered my kit in early March, so far no news on that shipment. I am still waiting for other parts but I did get 250 ohm headphones going that will match my build once I finish the cosmetics.


----------



## i luvmusic 2

I prefer the 6CG7 or 6SN7 for me the sound of these tubes is more relax than the 12AU7 their  are times that the 12AU's can be warm sounding to my liking.


----------



## Timoteo80

paladin79 said:


> Those are decent enough photos. I look forward to experimenting with various tubes to find those I like best and thankfully there is plenty of info out there describing what others have tried. The biasing LED is pretty obvious in the photo.
> 
> I must have ordered my kit in early March, so far no news on that shipment. I am still waiting for other parts but I did get 250 ohm headphones going that will match my build once I finish the cosmetics.




Well if you ordered early March then plan on an early/mid April shipment. My SpeedBall took just under 6 weeks to ship. That was during the NewYear time so it was busy for them. I was in no rush tho so it didn't bother me. Funny thing, I STILL haven't installed the SB! Just LOVING my stock Crack. I just wanted the SB on hand for the day I want to upgrade. What a great amp Doc at BH has designed. My hat goes off to that genius!!


----------



## TeeReQs

Check this list for where they're at in terms of shipping things out:
  
 http://bottlehead.com/bottlehead-kit-delivery-status/


----------



## Paladin79

This is the style quarter inch stereo jack I will use in the crack, it should be nickel plated brass and once i remove the outer coating it should look good with the build. It is long enough to fit through an inch thick cabinet and made by Switchcraft, a quality brand. 





teereqs said:


> Check this list for where they're at in terms of shipping things out:
> 
> http://bottlehead.com/bottlehead-kit-delivery-status/


 

 Yeah I have been checking the list and mine should take a little while yet. No biggy I have ordered some tools and parts that should take a while to get here. Once my cabinet is built i will have to decide on which of five or six finishing methods i want to use for quartered oak. I should be able to get it somewhat functional and then mount some parts in the box later. I have laid out entire television chassis and extended high voltage, convergence, and deflection so the thought of the components laid out before installation is not too scary. I will start on the top plate first and get the transformer and tubes mounted but that is all I intend to put there and that plate can sit on the old box for a bit. I will be adding a small transformer for my VU meters but everything will be well shielded. If I were to end up with hum, i will troubleshoot it. Before I do anything I have to fabricate the top, front and back plates. I want to do all cutting before I apply a patina to the copper. (sodium-chloride, nitrogen, and hydrogen). That process will take a couple days in itself.


----------



## Demoninja

Hey all, I had a question about my stepped attenuator. I used it in my build and had no issues with it. However this weekend I rebuilt my Crack all the resistance values and voltages were good. Unfortunately when I tested the Crack with my headphones, when I turned the attenuator up 4 "steps" the right channels gets significantly louder and I can't hear the left channel. Steps "3" and "5" are both completely fine. Does this mean I somehow damaged my attenuator in the process or are there any steps I can take to test this before purchasing a new one?
  
 Thanks all.


----------



## TurbOSquiD67

Will the R1 resistor values on the speedball boards need to be adjusted if one would like to run a 6SN7? I'm running a Crackatwoa, but know that I need an adapter for the 6SN7, and that the R1 resistor positions on the small C4S board may need adjusting. I could try the tube, then adjust accordingly, but unsure if voltages will be too far off and harm anything without adjusting first.
  
 Thank you,
  
 -T


----------



## Tom-s

In Crack the 6SN7 work just fine with the normal 137 Ohms R1 (voltages within normal limits).
 Give it a shot. Monitor your voltages to be sure.


----------



## deserat

demoninja said:


> Hey all, I had a question about my stepped attenuator. I used it in my build and had no issues with it. However this weekend I rebuilt my Crack all the resistance values and voltages were good. Unfortunately when I tested the Crack with my headphones, when I turned the attenuator up 4 "steps" the right channels gets significantly louder and I can't hear the left channel. Steps "3" and "5" are both completely fine. Does this mean I somehow damaged my attenuator in the process or are there any steps I can take to test this before purchasing a new one?
> 
> Thanks all.


 
  
 If only level 4 is  wrong, I would check for solder bridges, exposed wires causing a short,  and/or broken resistor leads. ( I'm assuming you have the ladder style with the resistors running around the outside. )


----------



## TurbOSquiD67

tom-s said:


> In Crack the 6SN7 work just fine with the normal 137 Ohms R1 (voltages within normal limits).
> Give it a shot. Monitor your voltages to be sure.


 
 Thanks Tom


----------



## Demoninja

deserat said:


> If only level 4 is  wrong, I would check for solder bridges, exposed wires causing a short,  and/or broken resistor leads. ( I'm assuming you have the ladder style with the resistors running around the outside. )


 
  
 Hey deserat, 
  
 Yeah only the one step is wrong. It's actually step 3 though not 4. I took a look at the resistors and nothing seems broken, reflowed them just in case. There aren't any exposed leads or cables everything is trimmed as nice and neat as I could. I checked for solder bridges between steps 2 and 3 as well as steps 3 and 4 but everything looks good. Really unsure about what could be the cause of this since the pot was working perfectly before.
  
 Is it safe to assume the problem is solely in the pot or is it possible that somewhere along the way something in the Crack circuitry is affecting this.


----------



## CarlosUnchained

Hello everyone!
  
 I'm new on this thread. I searched around but I couldn't find the answers.
  
 1. How does the Crack pairs with the LCD-X?
  
 2. Since I'm not sure about my abilities, is there any place to buy prebuilt?


----------



## adydula

If I read the specs correctly they are 20 ohm headphones...
  
 Cack is output transformerless amp designed for higher impedance heeadpones like the Sennheiser, AKG, and Beyer designs.
  
 20 ohms is not "higher impedance"....
  
 Not a good choice for these headphones...IMO
  
 Alex


----------



## Allanmarcus

carlosunchained said:


> Hello everyone!
> 
> I'm new on this thread. I searched around but I couldn't find the answers.
> 
> ...


 

 not well. It only works well with high impedance headphones.


----------



## Paladin79

adydula said:


> If I read the specs correctly they are 20 ohm headphones...
> 
> Cack is output transformerless amp designed for higher impedance heeadpones like the Sennheiser, AKG, and Beyer designs.
> 
> ...


 
 I checked a few AKG models and the ones I saw were rated at 62 ohms. What models do you feel would work or is the 62 ohm high enough?


----------



## Paladin79

carlosunchained said:


> Hello everyone!
> 
> I'm new on this thread. I searched around but I couldn't find the answers.
> 
> ...


 
 There are some completed ones on ebay, one is going for as much as $650 as I recall. The folks at Bottlehead may be able to build you one for a certain price. Heck if you buy a kit and send it to me, I would probably build you one for a couple bottles of single malt scotch. (I get to pick the scotch.)
  
 If you wanted one with all the modifications I will make on my own, that is doable as well except the scotch requirement suddenly aged by a decade or so.


----------



## CarlosUnchained

paladin79 said:


> There are some completed ones on ebay, one is going for as much as $650 as I recall. The folks at Bottlehead may be able to build you one for a certain price. Heck if you buy a kit and send it to me, I would probably build you one for a couple bottles of single malt scotch. (I get to pick the scotch.)


 

 I would gladly pay you for that! Unfortunately it won't be a good match for my LCD-X. I think S.E.X. would be better, but it's out of my price range.


----------



## Paladin79

carlosunchained said:


> I would gladly pay you for that! Unfortunately it won't be a good match for my LCD-X. I think S.E.X. would be better, but it's out of my price range.


 

 Give me your price range for a built crack and a set of headphones that would work with it. And please tell me you are in the continental US otherwise worldwide shipping and customs and such might get messy.


----------



## CarlosUnchained

paladin79 said:


> Give me your price range for a built crack and a set of headphones that would work with it. And please tell me you are in the continental US otherwise worldwide shipping and customs and such might get messy.


 
  
 Right now I'm looking something to get the best out of the LCD-X.
  
 Aaaand nowhere near US. Right now Asia but in a few months I'll be back in Europe.
  
 Customs are messy as phuck in my country. Held the X's for a month and asked me for too much money to release them.
 It's just a mandatory kidnaping.


----------



## Paladin79

carlosunchained said:


> Right now I'm looking something to get the best out of the LCD-X.
> 
> Aaaand nowhere near US. Right now Asia but in a few months I'll be back in Europe.
> 
> ...


 

 not a problem and I just checked the price on the SEX so it probably would not have been doable anyway.  If anyone else needs one built I do not mind helping out, within reason lol.


----------



## deserat

demoninja said:


> Hey deserat,
> 
> Yeah only the one step is wrong. It's actually step 3 though not 4. I took a look at the resistors and nothing seems broken, reflowed them just in case. There aren't any exposed leads or cables everything is trimmed as nice and neat as I could. I checked for solder bridges between steps 2 and 3 as well as steps 3 and 4 but everything looks good. Really unsure about what could be the cause of this since the pot was working perfectly before.
> 
> Is it safe to assume the problem is solely in the pot or is it possible that somewhere along the way something in the Crack circuitry is affecting this.


 
  
 I would bet it's the attenuator, but it could be elsewhere. Pots and Attenuators adjust resistance so you could  try hooking up your MultiMeter set to "ohms" to the in and out of each channel then reading and writing down the resistance at each step, first left channel, then right channel. If the resistance doesn't match for left and right at each step or if the one of the steps is not between  Step -1 and Step +1 ( Step 3's resistance is not between Step 2 and Step 4 ) then it's the Attenuator.  Could be a bad resistor. Depending on the cost of your attenuator, it might be worth replacing the resistor or the whole attenuator.


----------



## adydula

Carlos, why dont you get an amp that will drive your LCDx's?? 
 or 
 Get a set of cans that will work with the Crack?
  
 I have a crack and 8 other amps....the crack is great, but there are other great amps that will work with your
 LCD'x s if thats what you really want to use..
  
 Alex


----------



## ProfFalkin

carlosunchained said:


> Right now I'm looking something to get the best out of the LCD-X.




A used Cavalli Liquid Carbon might do it. Have heard good things.


----------



## Allanmarcus

carlosunchained said:


> paladin79 said:
> 
> 
> > Give me your price range for a built crack and a set of headphones that would work with it. And please tell me you are in the continental US otherwise worldwide shipping and customs and such might get messy.
> ...


 
  
 You should read and post in the LCD-X thread. Lot's a good advice and expertise there.
  
 http://www.head-fi.org/t/684394/audeze-lcd-x


----------



## Paladin79

Getting back to Crack discussion, hopefully the amps ordered during the sale will ship soon. I check shipping status but nothing as yet.


----------



## buke9

paladin79 said:


> Getting back to Crack discussion, hopefully the amps ordered during the sale will ship soon. I check shipping status but nothing as yet.


It took 6 weeks I think to get my Speedball upgrade so this should be about the same.


----------



## Paladin79

Cool cause I am anxious to start the build and check out the ground setup so I can see how I can rearrange things. I have a few types of AC switches I want to use but I definitely want something brass and ancient looking. Toggle or push button.


----------



## ProfFalkin

paladin79 said:


> Getting back to Crack discussion, hopefully the amps ordered during the sale will ship soon. I check shipping status but nothing as yet.



Got mine a week ago


----------



## Paladin79

Unfortunately I am working seven days a week right now but I could get started on a few things when mine shows up, at least the metal plates and cabinet. I will need a low voltage ac source for my VU meters and I may go with a wall-wart and a decent grade of cable going into the box. It is easy enough to unplug it to insure there are no issues.


----------



## LikeABell

paladin79 said:


> Unfortunately I am working seven days a week right now but I could get started on a few things when mine shows up, at least the metal plates and cabinet. I will need a low voltage ac source for my VU meters and I may go with a wall-wart and a decent grade of cable going into the box. It is easy enough to unplug it to insure there are no issues.


 
 I'm just wondering, won't a VU meter degrade the quality of the audio signal in any way?
  
 Do note I have no knowledge of all this.


----------



## Paladin79

likeabell said:


> I'm just wondering, won't a VU meter degrade the quality of the audio signal in any way?
> 
> Do note I have no knowledge of all this.


 

 If properly done I doubt it would affect much. Such meters have been used for decades on audio equipment. No matter what, I own three oscilloscopes and various other equipment with which I can examine the signal. My biggest concern is shielding and grounds. Generally you have chassis ground, signal ground, and power supply ground. I have not looked over the pdf's much yet but if anything I will probably over shield parts of mine to be safe. Twisted pair is good, shielded twisted pair is even better but you only want to connect the shield to the source end in my experience. It has been a while since I studied tube theory but I am hoping some of it comes back to me lol.


----------



## Allanmarcus

paladin79 said:


> likeabell said:
> 
> 
> > I'm just wondering, won't a VU meter degrade the quality of the audio signal in any way?
> ...


 

 There is a ground that runs throughout the Crack's circuitry. My guess is that you want everything "ground" related to be in sync with the central ground that runs throughout the Crack. all the voltage checks assume it's the same ground.


----------



## Paladin79

allanmarcus said:


> There is a ground that runs throughout the Crack's circuitry. My guess is that you want everything "ground" related to be in sync with the central ground that runs throughout the Crack. all the voltage checks assume it's the same ground.


 

 That would in essence be chassis ground but I will know more when I see it up close. Since I will have three different copper plates I will look at running a common ground. between the three. If I have any issues I will troubleshoot it. I am still toying with the idea of grabbing a second unit since I may not hear this one in its standard state. I would like to do my own and have a reference. The way they appear to be selling on Ebay I doubt I would get stuck if I built two. There is one there now with a guy asking $650 that is pretty much stock except he spray painted the top plate. His wiring is nice but not $300 worth of nice. I could also try to borrow one, send a UPS call tag and then ship it back in a few days. Having not heard one yet, I prefer to approach things this way.


----------



## Allanmarcus

paladin79 said:


> allanmarcus said:
> 
> 
> > There is a ground that runs throughout the Crack's circuitry. My guess is that you want everything "ground" related to be in sync with the central ground that runs throughout the Crack. all the voltage checks assume it's the same ground.
> ...


 

 Asking price is irrelevant on eBay. Click the 'Completed Listing' check box to see what stuff actually sold for. that said, an well mad stock unit should sell for what you paid, but remember that you lose money with eBay and paypal fees.


----------



## Paladin79

allanmarcus said:


> Asking price is irrelevant on eBay. Click the 'Completed Listing' check box to see what stuff actually sold for. that said, an well mad stock unit should sell for what you paid, but remember that you lose money with eBay and paypal fees.


 
 Yeah I know this Allan, I have been dealing with ebay since its inception and with a similar company prior to that. I merely stated there was one on there asking that price. I am well aware of the fees as well, I have in excess of 1,000 sales and purchases there.
  
 There was also one with an ASKING PRICE of $345 nonworking. Odd thing though it states it has speedball with it but I do not see that in the internal view lol.  The seller did add later that the speedball is new and uninstalled. It would not be a bad deal except I do not want to pay quite that much for a non-working one since there is a working unit with Speedball installed that could go for similar money or less.


----------



## Paladin79

Quote: 





likeabell said:


> I'm just wondering, won't a VU meter degrade the quality of the audio signal in any way?
> 
> Do note I have no knowledge of all this.


 
 I did some research and I do believe I will be fine with the VU meters. It has been years since I studied D'arsonval meter movements in college but the old analog meters will add some style and substance to the amp in my humble opinion. I may have to vary a series resistance to get the deflection I am hoping for but that theory I know. The meters have a range of 100 to 500 micro amp and they are not hard to hook up. I will have more trouble mounting them onto the 1/8 inch copper plate but I do have a variety of metal hole saws on the way. I also have a Dremel tool and a three in one Dremel device that can do routing and can cut circular holes 
  
 I just ordered a second bottlehead crack that I will build stock. I will then have a baseline with which to compare any changes I make to the second crack. When and if all goes well I already have all parts needed to build two Cracks using copper plate, quartered oak, VU meters, dual volume controls etc. I will then list one on Ebay so see what others feel it might be worth. (The value of an item often rests in what people are willing to pay for it.) This may not be the best approach but it is my approach. Worst case scenario is the second amp does not sell and I have one to use in my office at work
  
 They are not mounted yet but here is the general idea for vu meters with dual volume controls to be centered on the front of the cabinet. The dials should give off a yellow glow and all you will see are two circles when mounted, possibly some brass headed rivets or bolts.
  
 Tom


----------



## deserat

paladin79 said:


> That would in essence be chassis ground but I will know more when I see it up close. Since I will have three different copper plates I will look at running a common ground. between the three. If I have any issues I will troubleshoot it. I am still toying with the idea of grabbing a second unit since I may not hear this one in its standard state. I would like to do my own and have a reference. The way they appear to be selling on Ebay I doubt I would get stuck if I built two. There is one there now with a guy asking $650 that is pretty much stock except he spray painted the top plate. His wiring is nice but not $300 worth of nice. I could also try to borrow one, send a UPS call tag and then ship it back in a few days. Having not heard one yet, I prefer to approach things this way.


 


 I dunno. Crack with Speedball is about 414 + tax.  So $250. Given it takes about 8 hours to build... that's roughly $30 an hour. Seems fair to me for a quality job built to sell. My auto mechanic certainly charges more.  I think people undervalue the time put into building the thing. For some of us it's a labor of love, but for most people it's why they don't own one. I'm always blown away when I see a Bottlehead build go for at  or just above it's kit value unless it's been used for a few years. But to each his own...


----------



## Paladin79

deserat said:


> I dunno. Crack with Speedball is about 414 + tax.  So $250. Given it takes about 8 hours to build... that's roughly $30 an hour. Seems fair to me for a quality job built to sell. My auto mechanic certainly charges more.  I think people undervalue the time put into building the thing. For some of us it's a labor of love, but for most people it's why they don't own one. I'm always blown away when I see a Bottlehead build go for at  or just above it's kit value unless it's been used for a few years. But to each his own...


 
 This guy does a nice job with the build but Bottlehead certainly makes it easy enough for anyone to build one if they take their time and read the directions. I think he said he got $650 for one on another site so more power to him. My labor of love will be in the cabinet and appearance, I have built some of my own electronics and designed some test equipment so it will not be overly difficult but it has been ages since I messed with tube circuitry so I am looking forward to that. I can recall hot and cold bias and a few choice things but my memory is a little rusty on some of the theory. Too long in solid state for me lol.  It is not life or death to me if I do not sell the second one and I will probably have $600 in materials on each when done, (kit plus upgrades). I am not concerned about the labor, I am guessing it will take me six hours to do a stock build but I may install some connectors to make the changeover easy once my testing is done.


----------



## DavidA

deserat said:


> I dunno. Crack with Speedball is about 414 + tax.  So $250. Given it takes about 8 hours to build... that's roughly $30 an hour. Seems fair to me for a quality job built to sell. My auto mechanic certainly charges more.  I think people undervalue the time put into building the thing. For some of us it's a labor of love, but for most people it's why they don't own one. I'm always blown away when I see a Bottlehead build go for at  or just above it's kit value unless it's been used for a few years. But to each his own...


 
 I was like you a few years ago and decided to take the plunge and build my own.  The cost of kit + speedball and the tools needed (multi-meter, soldering station, solder, flux, etc) was about $450 since the kit + speedball were on sale at the time.  It took me about 14 hours to build, started at 5pm and finished at 7am, granted my GF helped and we enjoyed a few bottles of wine along the way but the skills gained have remained and have enhanced my love of audio and saved me more than enough to pay for the equipment I purchased a few times over.  I've built new cables for almost all my headphones, done mods for removable cables on a few Grados, Beyer T1/DT-990, MDR-7506, ATH-M50, K553, TH-600, TH-900, and build a few headphones along the way. 
  
 I can understand that its not for everyone but if you have ever considered building your own cables or even to repair broken cables, and other simple house hold task building the Crack is a great learning tool and the knowledge you gain will be useful for years to come.


----------



## Paladin79

davida said:


> I was like you a few years ago and decided to take the plunge and build my own.  The cost of kit + speedball and the tools needed (multi-meter, soldering station, solder, flux, etc) was about $450 since the kit + speedball were on sale at the time.  It took me about 14 hours to build, started at 5pm and finished at 7am, granted my GF helped and we enjoyed a few bottles of wine along the way but the skills gained have remained and have enhanced my love of audio and saved me more than enough to pay for the equipment I purchased a few times over.  I've built new cables for almost all my headphones, done mods for removable cables on a few Grados, Beyer T1/DT-990, MDR-7506, ATH-M50, K553, TH-600, TH-900, and build a few headphones along the way.
> 
> I can understand that its not for everyone but if you have ever considered building your own cables or even to repair broken cables, and other simple house hold task building the Crack is a great learning tool and the knowledge you gain will be useful for years to come.


 
 Well said David.I taught my son some electronics starting when he was four and he was able to repair his own plasma tv not too long ago with me shipping him a few parts. All knowledge is good. Just making a few measurements inside the amp with a voltmeter will help a few people down the road. I bought a kit from an individual knowing my kit has not shipped yet from Bottlehead, I am anxious to get going with both of the amps I will build. My son may end up wanting one of the two after he sees the outcome, or he will hate it, generally there is no in between.


----------



## Timoteo80

paladin79 said:


> Getting back to Crack discussion, hopefully the amps ordered during the sale will ship soon. I check shipping status but nothing as yet.




Took 6 weeks to get my SB upgrade as well & that was just before the sale. I hope yours ships soon. Plan on 4-6 weeks from order date. They are pretty good at that time frame & im sure they were somewhat prepared for the larger than normal order volume during the sale. BTW I STILL haven't installed the SB hahaha. Stock Crack is just mesmerizing & I haven't wanted to mess with it yet


----------



## Paladin79

timoteo80 said:


> Took 6 weeks to get my SB upgrade as well & that was just before the sale. I hope yours ships soon. Plan on 4-6 weeks from order date. They are pretty good at that time frame & im sure they were somewhat prepared for the larger than normal order volume during the sale. BTW I STILL haven't installed the SB hahaha. Stock Crack is just mesmerizing & I haven't wanted to mess with it yet


 
 I finally bought a second kit from an individual that should be here in a couple days. Still waiting on Bottlehead to ship but I have not checked them lately. I am building one stock, so I will know how my modified one compares. I am lacking two brown bakelite octal sockets if anyone out there has a couple they want to unload. Gold or brass plated preferred. I bought some from a photo on ebay from off shore and they turned out to be black bakelite with silver housings.


----------



## TeeReQs

Looks like they are still on orders from 2/28. I'm sure there was a ton from the sale.


----------



## Paladin79

teereqs said:


> Looks like they are still on orders from 2/28. I'm sure there was a ton from the sale.


 
 Oh good, at least I do not feel too bad about buying a second one quickly then lol. I have a plan with which I can  swap things in and out pretty fast to convert quickly from a stock unit to my dream build and back again within five minutes or so. I have two sets of VU meters from a couple manufacturers to try out. They are identical in size and range but have a slightly different dial.I have a half dozen logarithmic pots arriving tomorrow, switching from dual gang to single is no biggy.


----------



## deserat

davida said:


> I was like you a few years ago and decided to take the plunge and build my own.  The cost of kit + speedball and the tools needed (multi-meter, soldering station, solder, flux, etc) was about $450 since the kit + speedball were on sale at the time.  It took me about 14 hours to build, started at 5pm and finished at 7am, granted my GF helped and we enjoyed a few bottles of wine along the way but the skills gained have remained and have enhanced my love of audio and saved me more than enough to pay for the equipment I purchased a few times over.  I've built new cables for almost all my headphones, done mods for removable cables on a few Grados, Beyer T1/DT-990, MDR-7506, ATH-M50, K553, TH-600, TH-900, and build a few headphones along the way.
> 
> I can understand that its not for everyone but if you have ever considered building your own cables or even to repair broken cables, and other simple house hold task building the Crack is a great learning tool and the knowledge you gain will be useful for years to come.


 
 I couldn't agree more with most of this. On the other hand I've a friend who who spent years in the music industry, tonight I've got my soldering iron fired up and am repairing a crappy cable for him.  I'm doing it for the experience of doing it. It's fun, but let's be honest if they guy wasn't my friend, I'd charge him for it... given what I make in my professional job, I'd charge him $60 an hour because I'm kinda new at this... that's just what my time is worth.

 I really dig the Crack, it's an AMP that dances on top  of music and I'd like to share the joy I have when I plug mine in with people who aren't going to build it.  Who will spend more than $650 on an amp they won't enjoy nearly as much. $650 is an arbitrary number, I couldn't tell you what a Crack is worth. I know I like it better than my Lyr2 and differently than my Mainline. But I strongly support a cottage industry of people who are willing to pay attention to detail building Cracks, so that; a) Bottlehead can sell more of them and b) people who won't build them can enjoy them.

 The other thing I know is that purists who insist the only people who should enjoy a thing are the people willing to risk screwing it up, and willing to risk building it themselves. Yes I'm better for it. Yes I learned alot. Yes I'll do it again for the fun... but most people just wanna have fun.   

 FYI... I'm not the guy charging $650 for a built crack. But I'd like to see enough volume in crack sells that Bottlhead could either lower the price, make something better, or hell - just comfortably stay in business.  Honestly, buy a built crack, build your own... use the Crack Circut to create a work of Art, I'm with you.  Demand everybody else do enjoy something really cool exactly the same you do.... well that's just counter productive.

 And hey, I'm sorry if I'm coming off argumentative... it's not my intent. There are number of people who responded to me and I don't have time to respond to a number of posts. I just summed it all up here. Peace out.


----------



## Paladin79

The Crack is a unique device that is pretty easy to research. Most people who would buy one built have probably been to the Bottlehead site and hopefully know the amp is for high impedance headphones before buying one built or building one themselves. When mine are finished they will not look like the traditional build so if I list one on Ebay I will mention upgrades and what the amp is capable of. It would be a little embarrassing if it did not sell but I may put a reasonable reserve on it so it does not sell too cheaply. The one for $650 is still there but a new one is now listed for $480 buy it now price complete with speedball as well. 
  
 I should receive a Crack kit for today, it is out for delivery. Even though I work 50 miles away technology is such today that my phone will get a video when the box is delivered. (I can also control thermostat and lighting from most anywhere as well.)  Finding time to build it will be interesting but I will work it in and probably have the basic amp with speedball built before my kit from Bottlehead arrives.


----------



## Doc B.

Some of you guys are, understandably, antsy to get your kits. Here's a little update I am cross posting from the Bottlehead Forum:
  
 Josh has been working like a madman the past few weeks getting ready to ship out the rather fantastic, record number of Crack kits that were ordered during the last sale. Everything is prepacked, I have maybe the last 10 or 15 panels left to brush as of this morning, and we are ready to slam these puppies out. The one small delay is that the power transformers that were due to arrive today have not. Apparently the hi-pot, which is a test to assure that the insulation in the transformers well exceeds any voltage they will ever see, did not meet spec on some. Our winder works to very strict standards and the transformers are being reworked as I type this. They are scheduled to ship Monday, and usually get here in two days. So God willin' and the river don't rise we should be blasting out mass quantities of Crack mid-week. 

 We apologize for going a few days over our shipping window estimate due to this. It's the first time in over 15 years of using them that our winder has had to rework a production run. Just like us, they won't send it out until they are sure it's right. On the positive side, when they do arrive Josh figures to be shipping around 50 kits a day so they should all be shipped out within a few days of the transformers' arrival.


----------



## Paladin79

Thanks for the update!


----------



## Doc B.

Some good news - we just found out that apparently the rework is on a different transformer that we use in a different kit, and the Crack power transformers could be here by Monday.


----------



## Paladin79

doc b. said:


> Some good news - we just found out that apparently the rework is on a different transformer that we use in a different kit, and the Crack power transformers could be here by Monday.


 

 Very cool, and I actually knew what a Hipot test was that you mentioned earlier.
  
 Tom


----------



## i luvmusic 2

I can't wait to see the STEAMPUNK Crack.


----------



## Paladin79

shhhhh Doc B is on here. He may never sell me another kit after I am done with the modifications on this one. 
  
 I do have the majority of the parts, two large planks of wood, bunches of copper. There will not be a silver thing showing on it if all goes well. Either copper, brass or gold will be used. Maybe the prongs on the AC plug but that will not show.
  
 I probably said this but the headphones will match at some point, they are functional but I need to work on cosmetics.


----------



## i luvmusic 2

I still have my burnt out CRACK that i want to redo however the Transformer is fried.


----------



## TeeReQs

Don't smoke the crack!


----------



## Paladin79

i luvmusic 2 said:


> I still have my burnt out CRACK that i want to redo however the Transformer is fried.


 

 They would probably fix it if you sent it back to them. I kind of doubt they would sell just the transformer.  There is a guy on Ebay with a non working one but he is asking $324 I think, it obviously has a burned resistor but that is still a lot for a non working unit IMHO.


----------



## i luvmusic 2

NO actually the CRACK got smoked by a lightning strikeLong story short my site trailer at the job site got strike  by a lightning awhile back.


----------



## i luvmusic 2

paladin79 said:


> i luvmusic 2 said:
> 
> 
> > I still have my burnt out CRACK that i want to redo however the Transformer is fried.
> ...


 
 Yes i discussed this awhile back with BH but for me to ship it back and forth is not worth it,Not like you guys from the US of A spoiled when it comes to shipping rates....


----------



## Paladin79

i luvmusic 2 said:


> NO actually the CRACK got smoked by a lightning strikeLong story short my site trailer at the job site got strike  by a lightning awhile back.


 
 Yikes.


----------



## i luvmusic 2

paladin79 said:


> i luvmusic 2 said:
> 
> 
> > NO actually the CRACK got smoked by a lightning strikeLong story short my site trailer at the job site got strike  by a lightning awhile back.
> ...


 
 The really bad thing is the insurance doesn't want to pay for any personal belongings because the trailer is only insured for limited business coverage.F@#ing account dept. man i wish i knew...


----------



## Paladin79

i luvmusic 2 said:


> The really bad thing is the insurance doesn't want to pay for any personal belongings because the trailer is only insured for limited business coverage.F@#ing account dept. man i wish i knew...


 
 Please do not take this question the wrong way. With the transformer being bad the lightning obviously came through the power and not the signal input. Are the wires to the transformer burned? Is it pretty obvious the transformer was wiped out? I have done a ton of work on lightning and power surge damage so I was just curious how you determined the transformer is bad. 
  
 Do you still  have the amp and can you take a couple photos?
  
 I am wanting to help if I can but I would need a little info first.


----------



## i luvmusic 2

paladin79 said:


> i luvmusic 2 said:
> 
> 
> > The really bad thing is the insurance doesn't want to pay for any personal belongings because the trailer is only insured for limited business coverage.F@#ing account dept. man i wish i knew...
> ...


 
 Yes the cable/Tranny are burnt as far as i can see the only salvageable parts is the wood case and the top plate.


----------



## Paladin79

i luvmusic 2 said:


> Yes the cable/Tranny are burnt as far as i can see the only salvageable parts is the wood case and the top plate.


 
 The majority of other parts are not super expensive, if you can get another transformer from Bottlehead I could repair or replace most anything else pretty easily. I am going to have factory pot, 1/4 inch jack, tube sockets wiring etc. left after my build. I will have the original cabinet and top plates and those do not help you much. Shipping it back and forth between Canada and the states would be troublesome but it could be done. I can even offer to send you kit parts I do not use no charge but the transformer is the kicker.
  
 I received a Crack kit yesterday but`have not so much as opened the box, I hope to check it out this weekend in between cable builds. There could be even more parts I could send you in an attempt to help out.


----------



## i luvmusic 2

paladin79 said:


> i luvmusic 2 said:
> 
> 
> > Yes the cable/Tranny are burnt as far as i can see the only salvageable parts is the wood case and the top plate.
> ...


 
 WOW!That is so nice of you
	

	
	
		
		

		
			





but thank you if i  build a next amp it would be different from the crack.I have an idea of using a rectifier tube and all my existing tubes so i don't need to do more costly tube rolling.congrats for your amp!


----------



## Paladin79

i luvmusic 2 said:


> WOW!That is so nice of you
> 
> 
> 
> ...


 
 You have always been most kind and if I could help I would.
 I ran into a slight snag with the control knobs for mine, they were to be turned from solid copper but the young man who would have done the work finally admitted he probably lacked the experience so I had already purchased bakelite knobs from the 20's or 30's that will add appeal to the finished product. My biggest holdup right now is a set of metal circle cutters that I will use for the tube sockets and VU meters. I will need to cut those holes before I start adding a patina to the copper. At least now I have the top plate I can match against the copper to insure my cuts are the correct sizes. I plan to mount the front and back plate with brass screws and eventually I will have to decide between solid brass or brass plated. Tube sockets will be mounted with copper rivets. I get cautious when I start to use dissimilar metals, I have had enough education in specific fields to know what I do not know. I hope that makes sense lol.
  
 My thanks go out to the folks who mentioned the proper top plate size, it allowed me to get the perfect copper plate for my project, it will line up perfectly!
 Instead of the thin slots I have something else in mind for ventilation, but I should figure out the pattern soon.


----------



## i luvmusic 2

I can't wait to see your finished amp.I just finished installing the choke in my amp the best $20 i've spent for this kit it makes the amp background quieter.


----------



## buke9

Same here sound like it will be cool if all goes well.


----------



## Paladin79

buke9 said:


> Same here sound like it will be cool if all goes well.


 
 I have an experienced woodworker doing my cabinets, I will do final finish. The oak I purchased is nearly an inch thick, a foot wide, and forty-five inches long. I have some tools but not the 30 years experience doing such things. The copper plate I purchased is perfect for my needs, There is a slight weight difference (cough) between it and the original plate but I am do not plan on carrying this amp around with me.
 The top plate in copper is like two pounds and it will not change much because I am only cutting three openings there. It should look cool and honestly the two round holes should not be an issue, the square opening will be a little tougher but I suspect the transformer will hide any deviations and I have two shots at this. I plan to keep the prettiest one.


----------



## Paladin79

i luvmusic 2 said:


> I can't wait to see your finished amp.I just finished installing the choke in my amp the best $20 i've spent for this kit it makes the amp background quieter.


 
 I hesitate to say what I have spent so far on my modifications of two kits and I am not exactly done yet. I do plan to have added room inside the cabinets for any changes I make. The one I keep for myself may well have a row of brass toggle switches on one side with appropriate old school bulbs but I have not thought that all the way through yet. They may end up on the matching headphone stand I plan to build with a cable connecting it to the amp. I may hide a dac there as well. I do not want anything real modern looking noticeably hooking right to the amp. 
  
 There is suddenly a new listing for a Crack on Ebay, $875 with walnut base. Pretty looking but I do believe the top plate is spray painted. I can definitely claim mine will be professionally assembled if I post one there but I have seen the Mundorf EVO caps for sale and $150 for those seems a little pricey but it has been a few weeks since I checked some out. Mine will most likely have dual Alps pots but those are one of three brands I will be testing. TKD makes a good volume pot but I always wonder when I see them selling for $100 out of Hong Kong, same with Alps when they are $10 out of China. I prefer going through known distributors for some parts.


----------



## TurbOSquiD67

Has anyone ran 50-70uF value for the output caps? How'd it sound? I understand 100uF is recommended, but anywhere from half to twice the stock value should be sufficient. Experimentation is in order for those who wish to do so? That is, without hurting anything correct? I'm curious to try a few values of different caps I have, and the total would be 70uF for each channel. 
  
 Happy listening,
  
 -T
  
 Edit:
 Confirmed it is OK to go half to twice the value. What about going past that?


----------



## Tom-s

Look up the exact calculations in the Output Capacitor Upgrading Questions thread on the BH forum.
  
 I'm using 90uF with great effect.


----------



## Paladin79

tom-s said:


> Look up the exact calculations in the Output Capacitor Upgrading Questions thread on the BH forum.
> 
> I'm using 90uF with great effect.


 
 Pardon my lack of knowledge on this subject but are those the capacitors use the Mundorf  EVO 100 ufd caps for? If so going to a different value results in pretty good savings sometimes at the same voltage rating it would appear. That in itself looks like a good reason to try the other values.


----------



## Doc B.

Just letting everyone know that the first big batch of sale Crack kits shipped out this afternoon. The rest will follow early next week. Thanks to everyone who ordered, we appreciate the support!


----------



## ProfFalkin

doc b. said:


> Just letting everyone know that the first big batch of sale Crack kits shipped out this afternoon. The rest will follow early next week. Thanks to everyone who ordered, we appreciate the support!



Thank you Doc!


----------



## buke9

I'm in the first batch cool. Will be here in a week. Might have time to build it before the Dayton meet. Hopefully the led fixes my old one.


----------



## Maxhawk

turbosquid67 said:


> Has anyone ran 50-70uF value for the output caps? How'd it sound? I understand 100uF is recommended, but anywhere from half to twice the stock value should be sufficient. Experimentation is in order for those who wish to do so? That is, without hurting anything correct? I'm curious to try a few values of different caps I have, and the total would be 70uF for each channel.
> 
> Happy listening,
> 
> ...


 
  
 It's a simple first order high pass filter. With C in microfarads and Z = headphone impedance, you can calculate the -3 dB frequency with this formula:
  
 f3 = 159000 / (C * Z)


----------



## Tom-s

paladin79 said:


> Pardon my lack of knowledge on this subject but are those the capacitors use the Mundorf  EVO 100 ufd caps for? If so going to a different value results in pretty good savings sometimes at the same voltage rating it would appear. That in itself looks like a good reason to try the other values.


 
  
 I'm using 90uf (3*30uf) paper in oil caps. Costs were 35€ shipped for 10 pieces (only used 6).
  
 Search MBGO 30uf on ebay.


----------



## Hofy

Thank you Doc. I have a tracking number.


----------



## Paladin79

I also have the tracking on my amp and one to build as a standard before I start modifications. I have to finish installing french doors today and then I hope to see if I can build a stock Crack amp in six hours.


----------



## i luvmusic 2

Have fun!


----------



## i luvmusic 2

I just finished installing a top handle for my amp.
 (Sorry for the crappy phone camera)


----------



## attmci

paladin79 said:


> I hesitate to say what I have spent so far on my modifications of two kits and I am not exactly done yet. I do plan to have added room inside the cabinets for any changes I make. The one I keep for myself may well have a row of brass toggle switches on one side with appropriate old school bulbs but I have not thought that all the way through yet. They may end up on the matching headphone stand I plan to build with a cable connecting it to the amp. I may hide a dac there as well. I do not want anything real modern looking noticeably hooking right to the amp.
> 
> There is suddenly a new listing for a Crack on Ebay, $875 with walnut base. Pretty looking but I do believe the top plate is spray painted. I can definitely claim mine will be professionally assembled if I post one there but I have seen the Mundorf EVO caps for sale and $150 for those seems a little pricey but it has been a few weeks since I checked some out. Mine will most likely have dual Alps pots but those are one of three brands I will be testing. TKD makes a good volume pot but I always wonder when I see them selling for $100 out of Hong Kong, same with Alps when they are $10 out of China. I prefer going through known distributors for some parts.


 
 deleted.


----------



## Paladin79

attmci said:


> Crack is not as popular as before. I doubt that $875 one can be sold in the coming weeks. No one will purchase that broken one for sure.
> 
> To max out a Crack, you need GEC 6AS7G and driver tubes like a 7316 which cost a lot of $$ these days.


 
 that is good advice. My purpose is not to make a killing on one and if I can get good results spending $30 on caps instead of $150, that is probably the route I will choose.
 The electronics is easy for me so I am concentrating on building what I consider a pretty amp, headphone rack, and matching headphones...Steampunk style. It takes a lot to impress some scientists I hang with so I want something jawdroppingly cool looking when completed. I will strive for excellent sound as well. I am trying to insure my modified version does not sound worse than an original and I am paying attention to the advice of experienced builders on capacitors, volume pots, etc. I am doing individual left and right volume controls, I prefer that setup and want to try ladder pots along with more conventional pots.
  
 I paid less for my extra Crack kit than the price the broken one is asking lol. 
  
 Interesting handles Luvmusic. if all goes well I will only have two tubes and the transformer showing on the very top. I got my work done on the french doors so now I need to take time for a cold beer and some lunch then on to the crack build. 
 Once again I will just do a stock build today and mark the top copper plate, final builds will come later once I receive more tools and more volume control pots.


----------



## Tom-s

Experiment #242.4: Telefunken ECC81 (ribbed) in the driver seat for a few hours. 
 Voltages are good with R1 = 470 Ohms (like E80CC, ECC40).
 Sound is nothing special. Lean tight bass. Like the average 12au7 but less dynamic, more congested.
 I like the 12au7 Telefunken's (ribbed) better.
  
 Beware this type of tube has a lot more gain (no problem for me since i use Crack as a poweramp only).
 And it might heat up your Speedball a bit.


----------



## Paladin79

Power amp huh? So perhaps two could be monoblocks.

Too nice of a day to stay indoors but after three hours I am close to installing the speedball upgrade.

I just got a set of circle cutters in the mail so I should be attacking some copper plate soon. I also got more Alps potentiometers but I need to hear an original crack before I decide on all changes.

My second kit should be here in a few days from Bottlehead.

Tom


----------



## nimmen

attmci said:


> Crack is not as popular as before. I doubt that $875 one can be sold in the coming weeks. No one will purchase that broken one for sure.
> 
> To max out a Crack, you need GEC 6AS7G and driver tubes like a 7316 which cost a lot of $$ these days.


 
 I would suggest 5998 or WE 421A + good 6sn7(I use brimar cv1988) with adapter, at least that's what i'm using, but not all 5998 domino plates are the same, have two, they do differ a lot, but construction differences are very small and subtle... Crack is absolute beast(with correct headphones) when paired up with great tubes and modded with care, next step for me would be stax probably, but I don't think i'll leave my modded crack for a while as can't find anything that sounds same in 2-3x the price range...


----------



## Timoteo80

doc b. said:


> Just letting everyone know that the first big batch of sale Crack kits shipped out this afternoon. The rest will follow early next week. Thanks to everyone who ordered, we appreciate the support!




No thank YOU for the amazing Crack you designed!!


----------



## MIKELAP

Anybody ever tried a ECC31(NR73/1280) type tube in there Crack it is a very nice sounding tube used with an adapter, normally used in a 6SN7 socket in this case a 6SN7 to 12AU7is added .Only thing heater current is rated at .95A used with a 5998 which is rated at 2.4A .is it cutting it close or would it be ok .I am  using this tube already in a WA22 rated at 1A/Channel .


----------



## Paladin79

I just finished a basic Crack, I have yet to install the Speedball because I wanted to test the basic amp for a bit and make sure all was well before I proceeded. Total build time including some RCA cables about five hours but speedball is bound to add an hour or two. Currently I am using the preamp out from a Valhalla 2 as a source. I may end up using the tube sockets in my custom builds, I am having trouble finding matching octal and nine pin sockets and I already have dimensions for these.
 I like the sound of the amp and it certainly has potential but I have not played more than six songs through it yet so it is a little early to form any opinions.


----------



## i luvmusic 2

paladin79 said:


> I just finished a basic Crack, I have yet to install the Speedball because I wanted to test the basic amp for a bit and make sure all was well before I proceeded. Total build time including some RCA cables about five hours but speedball is bound to add an hour or two. Currently I am using the preamp out from a Valhalla 2 as a source. I may end up using the tube sockets in my custom builds, I am having trouble finding matching octal and nine pin sockets and I already have dimensions for these.
> I like the sound of the amp and it certainly has potential but I have not played more than six songs through it yet so it is a little early to form any opinions.


 
 Congrats and enjoy.


----------



## i luvmusic 2

Sorry double post.....


----------



## Paladin79

i luvmusic 2 said:


>


 
 I will need to install the speedball one day soon and by next weekend after my second kit arrives I can start experimenting. I did take time to make a few measurements, I trust my builds but it seemed a little silly to take chances.
  
 I need to try the amp with other sources, and eventually other tubes, with a few tweaks I feel I will like the amp more and more.


----------



## buke9

paladin79 said:


> I will need to install the speedball one day soon and by next weekend after my second kit arrives I can start experimenting. I did take time to make a few measurements, I trust my builds but it seemed a little silly to take chances.
> 
> I need to try the amp with other sources, and eventually other tubes, with a few tweaks I feel I will like the amp more and more.


Definitely different tubes the RCA is not real good.


----------



## Paladin79

buke9 said:


> Definitely different tubes the RCA is not real good.


 
 Yeah it will be a work in progress for a while. I have decided on the VU meters I want to use.
  

 Similar dials but the one on the right has the color I was seeking in the back light. They are easy to adjust and set up as long as you have a basic understanding of electronics, some test equipment and are used to working with Chinese instructions.
  
 Listening to the Crack now, the sound is starting to smooth out a bit, I am starting to like it more. I am probably a little too used to solid state and amps like the Valhalla 2 which sounds solid stateish


----------



## buke9

paladin79 said:


> Yeah it will be a work in progress for a while. I have decided on the VU meters I want to use.
> 
> 
> 
> ...


 Yes the tubes definitely will need a bit of time to warm up and get cooked off and the rest of the system to come to temp and burn in a bit. Some will disagree with burn in but after dealing with the Ether-C's and Yggdrasil there is something to say about it for those two for sure. The meters will be a nice touch I like the look.


----------



## Paladin79

buke9 said:


> Yes the tubes definitely will need a bit of time to warm up and get cooked off and the rest of the system to come to temp and burn in a bit. Some will disagree with burn in but after dealing with the Ether-C's and Yggdrasil there is something to say about it for those two for sure. The meters will be a nice touch I like the look.


 
 I need to get to work on the cabinet design, start cutting copper, and decide if I want to do ladder pots by Dale or go with Alps. A bigger cabinet will certainly help.
  
 I will stick with stock sockets but otherwise everything I originally conceived is doable. 
  
 The bass sounds especially good.


----------



## i luvmusic 2

paladin79 said:


> i luvmusic 2 said:
> 
> 
> >
> ...


 
 I'am glad that you like the amp but once the upgraditis sits in i feel sorry for your wallet.


----------



## buke9

paladin79 said:


> I need to get to work on the cabinet design, start cutting copper, and decide if I want to do ladder pots by Dale or go with Alps. A bigger cabinet will certainly help.
> 
> I will stick with stock sockets but otherwise everything I originally conceived is doable.
> 
> The bass sounds especially good.


Yes going to do my own cabinet still haven't found anyone to do any resawing or has a big planer. Most will not touch rough cut stuff that I felled myself. I have a few boards that I can make work of my walnut but might have get some new knives for my planer/joiner as I think 6 in's should be tall enough for some big caps and whatever else but there is a nic in it that has about a 1/32 bump that would probably sand out but I'd rather not. I think the contrast of the white sockets on the copper might look good. I know you wanted the Bakelite but it might work anyway. Can't wait to see your creation.


----------



## Paladin79

I am fortunate to work in the industry. Some things I can get at a discounted rate or as samples. I already own all major parts for the cabinets so that cost is over.


NOS tubes are another story lol.


----------



## Paladin79

buke9 said:


> Yes going to do my own cabinet still haven't found anyone to do any resawing or has a big planer. Most will not touch rough cut stuff that I felled myself. I have a few boards that I can make work of my walnut but might have get some new knives for my planer/joiner as I think 6 in's should be tall enough for some big caps and whatever else but there is a nic in it that has about a 1/32 bump that would probably sand out but I'd rather not. I think the contrast of the white sockets on the copper might look good. I know you wanted the Bakelite but it might work anyway. Can't wait to see your creation.


 
 You are most kind Buke and I bet you figure out a way to use the walnut. The nine pin style sockets I bought did not have the center conductor like the kit part anyway. Until I received one it was a little tough to figure some things out. There is one on Ebay with a burled walnut cabinet that is fabulous looking and that would have been my second choice. The copper plate I bought was precisely the same size as the original and just a little thicker so if you ever want to go that route I will hook you up with the source. My cabinets will be taller than the originals and a little wider and deeper so I will have room for some changes.


----------



## buke9

paladin79 said:


> You are most kind Buke and I bet you figure out a way to use the walnut. The nine pin style sockets I bought did not have the center conductor like the kit part anyway. Until I received one it was a little tough to figure some things out. There is one on Ebay with a burled walnut cabinet that is fabulous looking and that would have been my second choice. The copper plate I bought was precisely the same size as the original and just a little thicker so if you ever want to go that route I will hook you up with the source. My cabinets will be taller than the originals and a little wider and deeper so I will have room for some changes.


Yes I will get it figure it out. I also have some Ambrosia Maple that I might make corner blocks rather than mitre joints. I also have a 6080 Tung Sol Chatham that I bought as a pair if you want to try one out. It will definitely make the Crack sound better.


----------



## Paladin79

buke9 said:


> Yes I will get it figure it out. I also have some Ambrosia Maple that I might make corner blocks rather than mitre joints. I also have a 6080 Tung Sol Chatham that I bought as a pair if you want to try one out. It will definitely make the Crack sound better.


 
 I would love to try one out you can ship it to my house or the business address is on our website.


----------



## Allanmarcus

No offense, but maybe you can take the wood negotiation to a PM. We are all interested in your crack, Paladin79. but maybe a few less public details


----------



## Paladin79

allanmarcus said:


> No offense, but maybe you can take the wood negotiation to a PM. We are all interested in your crack, Paladin79. but maybe a few less public details


 
 You might want to reread Allan, we were talking about tubes. No one was negotiating for wood.


----------



## Guidostrunk

Wood and Crack , in the same post. Hilarious!


----------



## Paladin79

LMAO!!!!  I do want to try other tubes, thanks Buke. later.


----------



## Allanmarcus

OK, sorry.


----------



## Paladin79

No biggy. The thread is on one amp and I have seen plenty of people modify them both inside and out. I have an interest in the electronics and the cosmetics. I will listen to anyone talking about either.

I just read through some posts on the Alps Blue velvet pots, as I said before I would generally only buy such things from a distributor. They are on ebay with different part numbers than Alps uses and by all accounts they are bogus parts. I thought it was a little funny that a Japanese part would be consistently shipped from China. They have a small paper sticker on the back saying Alps but it is awfully easy to create such stickers. A pretty good example of caveat emptor.


----------



## attmci

nimmen said:


> I would suggest 5998 or WE 421A + good 6sn7(I use brimar cv1988) with adapter, at least that's what i'm using, but not all 5998 domino plates are the same, have two, they do differ a lot, but construction differences are very small and subtle... Crack is absolute beast(with correct headphones) when paired up with great tubes and modded with care, next step for me would be stax probably, but I don't think i'll leave my modded crack for a while as can't find anything that sounds same in 2-3x the price range...


 
 Try a Long Plate D Getter w/ Foil Strip 7316. You will love it.


----------



## Tom-s

What is the factory of these?


----------



## deserat

buke9 said:


> Yes the tubes definitely will need a bit of time to warm up and get cooked off and the rest of the system to come to temp and burn in a bit. Some will disagree with burn in but after dealing with the Ether-C's and Yggdrasil there is something to say about it for those two for sure. The meters will be a nice touch I like the look.


 
 I was just asking about burnin on a Mainline I recently finished, and Doc popped into confirm that Bottlehead themselves believe in and account for burn in when testing new circuts.  It took about 40 hours for my Crack to settle in completely  after I built it.  

 Had the same experience with the Ether C though that was closer to 100 hours.


----------



## Doc B.

attmci said:


> Crack is not as popular as before.


 
 Ah, that explains why the most recent sale was the biggest one we have ever had.


----------



## Paladin79

doc b. said:


> Ah, that explains why the most recent sale was the biggest one we have ever had.


 
  
 LOL, ok well that answers that.
  
 My amp should be arriving Friday and I am sending a small gift to Doc that should be there about the same time.


----------



## attmci

doc b. said:


> Ah, that explains why the most recent sale was the biggest one we have ever had.


 
 Ooooooops.  Don't get me wrong. 
  
 Congratulations on the successful sale.


----------



## buke9

deserat said:


> I was just asking about burnin on a Mainline I recently finished, and Doc popped into confirm that Bottlehead themselves believe in and account for burn in when testing new circuts.  It took about 40 hours for my Crack to settle in completely  after I built it.
> 
> 
> Had the same experience with the Ether C though that was closer to 100 hours.


I let the C's go for 150 but it still took another 50 for me before they settled in. Mine was a pre built Crack so I don't know if it was burned in or not but my new one will be though. I hope the new leds fix my old one . I haven't had any Crack for two months now I'm jones'n something fierce.


----------



## Tom-s

attmci said:


> Try a Long Plate D Getter w/ Foil Strip 7316. You will love it.


 
  


tom-s said:


> What is the factory of these?


 
  
  Amperex 7316 can be a lot of factories (like any Philips tube). The D-strips Foil getter ECC82 come from the Heerlen factory in my collection (Branded as Philips, Adzam, Valvo). And the Amperex bugle boy ECC82's are from Heerlen aswel.


----------



## Paladin79

buke9 said:


> I let the C's go for 150 but it still took another 50 for me before they settled in. Mine was a pre built Crack so I don't know if it was burned in or not but my new one will be though. I hope the new leds fix my old one . I haven't had any Crack for two months now I'm jones'n something fierce.


 
  LOL,If the LED's do not fix it I will trouble shoot it if you like as a thank you for lending me the tube. I have yet to install the speedball upgrade but I understand the circuitry enough to repair one.
  
 You have received the LED's I hope.
  
 My second Crack arrives this Friday but I have things to do before I start modifications, I will be cutting openings in copper soon.


----------



## TeeReQs

Crack has shipped. Woo hoo. This should be a nice project for the weekend.


----------



## Paladin79

teereqs said:


> Crack has shipped. Woo hoo. This should be a nice project for the weekend.


 
 I should be building the newer version as well soon. Just glad I decided to run it as a basic amp before installing the speedball. Something in my psyche reacts when i have to rip out parts I just put into something but it needs to be done for the upgrade. You should have a lot of fun building it, just pay close attention to the upper and lower solder lugs and you should be fine.


----------



## TeeReQs

paladin79 said:


> I should be building the newer version as well soon. Just glad I decided to run it as a basic amp before installing the speedball. Something in my psyche reacts when i have to rip out parts I just put into something but it needs to be done for the upgrade. You should have a lot of fun building it, just pay close attention to the upper and lower solder lugs and you should be fine.


 
 Im definitely going to build it sans speedball first. A buddy of mine built me a custom wood desk, and I need to find out what color stain he used so I can match the crack to it.


----------



## Paladin79

teereqs said:


> Im definitely going to build it sans speedball first. A buddy of mine built me a custom wood desk, and I need to find out what color stain he used so I can match the crack to it.



Great I watched several videos on finishing quartered oak but I will have to watch them again. I doubt you will have problems but I will help if you have issues.


----------



## attmci

tom-s said:


> Amperex 7316 can be a lot of factories (like any Philips tube). The D-strips Foil getter ECC82 come from the Heerlen factory in my collection (Branded as Philips, Adzam, Valvo). And the Amperex bugle boy ECC82's are from Heerlen aswel.


 
 Yes,  the tube with a delta sign. Attached is a picture of a foil D gutter. 
  
 But a 7316 is an ecc82 substitute and they sounds quite different (at least to me). 
  
 Some ref. here:
  
 https://www.audioasylum.com/messages/tubes/170117/re-amperex-7316


----------



## buke9

teereqs said:


> Im definitely going to build it sans speedball first. A buddy of mine built me a custom wood desk, and I need to find out what color stain he used so I can match the crack to it.


Myself I would go with something that contrasts it to make it stand out.


----------



## TeeReQs

buke9 said:


> Myself I would go with something that contrasts it to make it stand out.


 
 That's actually not a bad thought. I'm thinking the top plate should be enough contrast, as the desk is really dark, but I guess I'll see once I get it.


----------



## nimmen

attmci said:


> Yes,  the tube with a delta sign. Attached is a picture of a foil D gutter.
> 
> But a 7316 is an ecc82 substitute and they sounds quite different (at least to me).
> 
> ...


 
  
 Thanks for info, may be worth checking it out, I would say for most of the time I am after "lush" type of sound.


----------



## Tom-s

Try Hamburg (Valvo) or Blackburn (Mullard) made Philips ECC82 tubes. Just a normal plate small O getter Hamburg Ecc82 can ben found cheap and sounds a million!
  
 Like these: http://www.ebay.de/itm/2-Doppel-Triode-ECC-82-VALVO-Code-Nr-Gf0-D9F-Messwerte-16-17-ma-16-17-ma-/391757452640?hash=item5b36905560:g:TfMAAOSw4CFY72SX
  
 NOT these (Valvo brand but Heerlen made, different getter, build): http://www.ebay.de/itm/ECC82-E82CC-12AU7-pair-VALVO-ribbed-plates-O-Getter-Tube-Rohre-Valvola-NOS-/152512896180?hash=item23827a1cb4:g:tTAAAOSw7U5Y82Cj
  
 And for Mullard goes the same, buy the early Blackburn versions, not the other factories.


----------



## Paladin79

After testing some Alps, Vishay, Bourns, and TKD pots I will probably go with the Alps on my dual builds. Single gang pots although I bought a couple duals in case I build Cracks for friends. I prefer single gang but not everyone does.
  
 The Alps I will be using have solder lugs like the original pot, so many are made for mounting in a circuit board that this style is not always easy to find.


----------



## Hofy

Mine arrived today. I only had time to check the parts list against contents before leaving the house.


----------



## Paladin79

Cool my second arrives tomorrow.


----------



## buke9

Mine is still on track for tomorrow.


----------



## ProfFalkin

Sorry for the potato pic, but I thought I'd share anyway...

Padauk Crack base build in progress.


----------



## ProfFalkin

.


----------



## Timoteo80

buke9 said:


> Definitely different tubes the RCA is not real good.




Really? I actually really enjoyed the stock RCA tubes. I have since purchased a hand full of others including NOS Mullard, NOS GE, RCA clear top & a couple 6as7's. I enjoy them all but the stock seem to be some of the cleanest of the group so far. What do you recommend as far as tubes?....


----------



## Paladin79

6080 Tung Sol Chatham
  
 Buke is sending me one of these to try out so apparently he likes it pretty well. I have only heard good things about Tung Sol but my tube knowledge is lacking. I used to own hundreds of them but technology changes so I am just getting back to them. Funny how the circle goes around, vinyl is making a comeback and people are looking for NOS tubes from the fifties and sixties.Kind of makes you want to start socking things away in a warehouse like Andy Warhol., Who knows what might have great value one day?


----------



## buke9

paladin79 said:


> 6080 Tung Sol Chatham
> 
> Buke is sending me one of these to try out so apparently he likes it pretty well. I have only heard good things about Tung Sol but my tube knowledge is lacking. I used to own hundreds of them but technology changes so I am just getting back to them. Funny how the circle goes around, vinyl is making a comeback and people are looking for NOS tubes from the fifties and sixties.Kind of makes you want to start socking things away in a warehouse like Andy Warhol., Who knows what might have great value one day?


Been super busy and forgot. It will get to you don't fret just might take a few more days.


----------



## Paladin79

I rarely fret and I was just saying I believed you liked that tube lol. For a while I will be busy building a modified Crack so no rush. I just found some blade switches I want to incorporate ( knife switches) and I am thinking through that. I have seen a couple Steampunk amps lately and need to step up my game.

Today I have been thinking about the wiring on the amps I will be building. I am extending two copper plates so grounding and shielding are definitely a factor.


----------



## HiddenFatKid

So I have HD600's, and i have DT770 premium 600ohm's in the mail coming to me right now, ive heard the crack pairs well with both of these, does it pair well with the HD800 too?


----------



## Paladin79

hiddenfatkid said:


> So I have HD600's, and i have DT770 premium 600ohm's in the mail coming to me right now, ive heard the crack pairs well with both of these, does it pair well with the HD800 too?


 

 The paperwork that comes with the Crack describes it as working best with headphones having an impedance of 100 or more so many high impedance headphones would pair well I would think. Individuals might prefer one pair of headphones over another but I believe you are in good shape once you get into the higher impedance threshold.


----------



## buke9

hiddenfatkid said:


> So I have HD600's, and i have DT770 premium 600ohm's in the mail coming to me right now, ive heard the crack pairs well with both of these, does it pair well with the HD800 too?


I have not heard the 800's on a Crack so can't say for sure but I have heard others say it is ok but most who buy the 800's generally go for a bit higher end amp but it is fantastic with 600's and 650's the later I own. I have heard the DT 880's 250 ohm from my amp and it was quite nice.


----------



## Tom-s

The beauty of the Crack is that you can make it work with most headphones > 120 Ohms (except maybe AKG K1K). Tubes can be rolled and modifications made so it can be seasoned to taste for each headphone's sound signature.


----------



## buke9

Well got the kit today and was starting to build the top plate and I've been shorted the ground lug screw. So now I'm counting the whole parts list. I probably have one around the house and know for sure have one at our shop but still a pain. I'm not going to request a replacement as I hope to have it done but it was checked off on the list so someone is slacking ; )


----------



## buke9

Well everything else is here sans one screw life could be worse.


----------



## DavidA

hiddenfatkid said:


> So I have HD600's, and i have DT770 premium 600ohm's in the mail coming to me right now, ive heard the crack pairs well with both of these, does it pair well with the HD800 too?


 

 ​It goes well with the HD800 to me, just might want to change the stock tubes.


----------



## HiddenFatKid

davida said:


> ​It goes well with the HD800 to me, just might want to change the stock tubes.


 
 awesome! it'll be a while before i get the 800's, but would you recommend getting the speedball or tube roll with something like the tung sol 5998 first?


----------



## DavidA

hiddenfatkid said:


> awesome! it'll be a while before i get the 800's, but would you recommend getting the speedball or tube roll with something like the tung sol 5998 first?


 

 ​I originally setup my BH Crack without the Speedball installed and liked how it sounded, began rolling tubes and after a year installed the speedball only to remove it a month later, I just liked the sound without the speedball better, a little more clarity and details to me.  Its also possible my speedball was defective but I've heard 2 other BH Crack's with the speedball and like mine without the speedball better. 
  
 With the cost of tubes and cap updates I would consider other options like the Elise (a noticeable improvement in sound stage but will need to roll some tubes), Hugo1/2 (one of the few that pairs well with both HD800 and HE560) or Liquid Glass (with a decent DAC and run balanced, really good with both HD800 and HE560).  Right now I have 5 amps (BH Crack, Lyr2, Ember, headphone output of UD-301, Asgard2) to pair with my various headphones but am trying to reduce it to 2-3, need the table space to put wine glasses on.


----------



## Paladin79

buke9 said:


> Well everything else is here sans one screw life could be worse.


 
 I should at least check if all the parts are there, I will not be starting the build for a little while but at least it is not a huge list to work through.
  
 I appear to have different tubes so I will see how a new Philips/ECG  tube compared to the older RCA in my other Crack.
  
 I just realized that I will be able to build one amp with the speedball upgrade and try it out side by side against an amp without and decide which I like better since it appears that opinions vary on the upgrade. It will be a while before I upgrade caps but other than that I am pretty well set on other things I will change out on my second Crack.


----------



## Allanmarcus

buke9 said:


> Well everything else is here sans one screw life could be worse.




You sure it wasn't loose in the box? because then we could all say....

You have a screw loose!


----------



## buke9

allanmarcus said:


> You sure it wasn't loose in the box? because then we could all say....
> 
> You have a screw loose!


I don't need one in the box for that.


----------



## buke9

Took a break from the new build to install a new led in the old Crack that was dead and it is alive again.


----------



## Paladin79

buke9 said:


> Took a break from the new build to install a new led in the old Crack that was dead and it is alive again.


 
 Glad to hear it Buke. If it ever happens again contact me, did you not have a fairly long wait for the diodes?
  
 Today I start cutting some copper plate and then on to the patination. That will take a day but hopefully tomorrow I start the build on my second Crack.


----------



## Allanmarcus

I'm comparing my Crack with some thinner sounding tubes to a stock Mjolnir 2 using the Utopia. With my "good" tubes, the utopia was way too bass/bloomy. I must say, the Crack holds its own. Bass is looser and bloomer on the Crack, even with the thinner tubes, which is expected given the 80 Ohm impedance of the Utopia. Still, pretty good and a sort of fun sound (Hotel California goes boom boom!). For bass heavy music it would be too much, for classical, it's quite good. Usable, but the Mj2 is better. and I have some better tubes on order for the Mj2.
  
 With good tubes and the HD800 or T1, the Crack totally holds its own.
  
 I guess it's Mainline time for me


----------



## Paladin79

Digital meters are great for some things but my old Simpson 260  analog meter is phenomenal for testing for audio or linear taper pots. You can watch the kick of the meter needle and not have to sit there and calculate the change on a digital meter.
  
 For bass test I use Hotel California but my all time favorite test is Nighttime at the Switching Yard by Warren Zevon and a couple Chuck E. Weiss songs that are a little obscure.
  
 Copper is considered a soft metal but when thick enough, it can take a while to work through. Cutting square or rectangular holes are going to be interesting. I tried a Dremel cutting wheel but the thing went flying across the room and made a successful escape. It may be in Canada by now.
  
 One plate is nearly ready for patination but alas there are three plates per amp and the front and the top plate are fairly easy. The back plate is causing me to entertain the idea of a large square opening in the back of the box with wires hanging out. It would probably be easier to train a cat to sit there and cover the opening but I will persevere. A couple good stiff drinks are called for but I am rather attached to my fingers and must face this with all possible sobriety.
  
 Solution, a metal cutting blade in a Bosch jigsaw.  Once again the world is spinning in greased grooves. Beats my other option which involved a hammer, chisel, bandaids and earplugs.

 Back plate nearly done, just leaves top plate and applying finish.


----------



## buke9

I love the 260 I almost bought one a couple years back . That is what we had when I was in the Navy then right before I got out we started getting Fluke 70's. If you want a bass track it would be for me "Da Funk" by Daft Punk.
Well the amp is coming together pretty well it seems.


----------



## Paladin79

buke9 said:


> I love the 260 I almost bought one a couple years back . That is what we had when I was in the Navy then right before I got out we started getting Fluke 70's. If you want a bass track it would be for me "Da Funk" by Daft Punk.
> Well the amp is coming together pretty well it seems.


 
 I have not touched this one in about five years and it fired right up, batteries were fine. i also have a bunch of Simpson digital 467's that were military surplus, they are still working fine.
  
 I am about done with my top plate then I need to clean all the copper and hopefully get started with the patina late tonight. 
 on to copper clean up for me, I put a large hole in the plate for a vent system that should go well with the Steampunk theme. I also have a few surprises but those will only be shown on the finished piece. The four holes around the transformer line up perfectly, I was rushing to try to get this finished today and lucked out. Hopefully the sockets fit well but I will find that out when I do the build, and install the vu meters.


----------



## Timoteo80

Damn Paladin79 I'm really digging the copper!! Wasn't sure how I felt but as I see it coming along I see the attraction. Nice job on the project so far bud! 2thumsup


----------



## Paladin79

timoteo80 said:


> Damn Paladin79 I'm really digging the copper!! Wasn't sure how I felt but as I see it coming along I see the attraction. Nice job on the project so far bud! 2thumsup


 
 You may not say that when you see the finished result lol, If all goes well with the chemicals, all plates are in the process of getting a green patina. What you see was before i buffed it out- a bit in prep for the patina, it had to be perfectly clean and oil free. I like the looks of the polished copper ones I have seen so I am considering doing that to my second one and then sealing it so it does not oxidize. I also have to do a little bit of tweaking, the switch is not perfectly straight but that will be on the back side anyway. I have two other switches to install and a mirror ball (just kidding).


----------



## Paladin79

It will be a couple weeks before the cabinets are done, the case will be taller to accommodate the meters in the front. That is copper mesh over the vent holes but that is just temporary.  
  
 Quote: 





buke9 said:


> I love the 260 I almost bought one a couple years back . That is what we had when I was in the Navy then right before I got out we started getting Fluke 70's. If you want a bass track it would be for me "Da Funk" by Daft Punk.
> Well the amp is coming together pretty well it seems.


 
 Buke I have an extra Alps dual gang volume control you can have if you ever want to do an upgrade on your existing pots. Say the word and it is yours gratis.I have some really good Alps single gang but they were a little large for the front plate I am using. They are ladder pots so I may figure out something to do with them on another build.
  

 Here is what happens to that lovely copper when you expose it to NaCl and NH3, this is happening in my shed maybe fifty yards from my house. A good place for it. I was expecting blues but so far I have greens, it is early. This is part of my current Crack build so it pertains to this thread, i guess. 
  
 The Bottlehead Cracks I expected to still be for sale are still for sale on Ebay. $875, $675, and $345 for non-working. I may well be offering the gentleman who is making my cabinets a percentage of whatever one of mine brings if i sell it there.
  
 With patina and sealed. Some assembly will take place today.


----------



## Paladin79

top view, no jacks or controls or switches will be on the top, my preference but probably not for everyone. Still considering options, the blade switches are just there for looks at this time. White contrasts well, I think Buke mentioned it should. No silver shall show.


----------



## i luvmusic 2

WOW!Nice patina.


----------



## Paladin79

i luvmusic 2 said:


> WOW!Nice patina,NO OFFENCE you are not planning to just put that knife switch where you set it?Makes me not to turn your amps ON,SORRY!


 
 Na I just set those there for looks lol, there will be no switches, jacks, or control pots on top. I happened across those and I and thinking about how to use them. If anything they will control low level DC if active. I am still kicking around steampunk ideas. I even mentioned they were just there for looks.


----------



## i luvmusic 2

paladin79 said:


> i luvmusic 2 said:
> 
> 
> > WOW!Nice patina,NO OFFENCE you are not planning to just put that knife switch where you set it?Makes me not to turn your amps ON,SORRY!
> ...


 
 I'am sorry!I misread your post that is why i edited it.


----------



## i luvmusic 2

BTW I'am in a process of building my own amp to compliment my CRACK,These transformers are not cheap it cost me $99 canadian peso including tax for both but these are the most expensive parts the rest are peanuts
  
 PS Palidin79 i might steal some of your ideas,Sorry!


----------



## Paladin79

i luvmusic 2 said:


> I'am sorry!I misread your post that is why i edited it.


 
 no harm done, scary looking are they not lol? If I replace a switch and use it in an AC circuit it will have a 15 amp rating like this one.
 I do have a background in electronics and when I am done the amp may look a little scary but it will be perfectly safe.


----------



## i luvmusic 2

paladin79 said:


> i luvmusic 2 said:
> 
> 
> > I'am sorry!I misread your post that is why i edited it.
> ...


 
 That one is much better i can sleep better tonight...


----------



## Paladin79

i luvmusic 2 said:


> BTW I'am in a process of building my own amp to compliment my CRACK,These transformers are not cheap it cost me $99 canadian peso including tax for both but these are the most expensive parts the rest are peanuts
> 
> PS Palidin79 i might steal some of your ideas,Sorry!


 
 If you want to do a patina on copper I can help, I did see some shiny steampunk amps lately so I am tempted to do one of those as well. The beauty of the patina is it hides scratches and such. I started with copper plate about 11 am yesterday, did all the cuts, prepped the copper and the rest was easy. Cutting the copper plate is the biggest issue.
  
 I am far from finished but most of the things I am working on are cosmetics since I thought through the electronics before I touched this amp.


----------



## i luvmusic 2

paladin79 said:


> i luvmusic 2 said:
> 
> 
> > BTW I'am in a process of building my own amp to compliment my CRACK,These transformers are not cheap it cost me $99 canadian peso including tax for both but these are the most expensive parts the rest are peanuts
> ...


 
 I can't decide what chassis i need to use these  amp that i'am building is top heavy those tranny's are heavy plus i might put in another transformer for the 12V tube heaters so i can drive 6.3V-12.6V tubes flexible amp i might say.I will PM you anytime i need your help,Thanks again!


----------



## Paladin79

i luvmusic 2 said:


> I can't decide what chassis i need to use these  amp that i'am building is top heavy those tranny's are heavy plus i might put in another transformer for the 12V tube heaters so i can drive 6.3V-12.6V tubes flexible amp i might say.I will PM you anytime i need your help,Thanks again!


 
 Not a problem, always glad to help. The 1/8 inch copper plate is plenty sturdy, 6 x 10 inches weighs just over two pounds.


----------



## i luvmusic 2

paladin79 said:


> i luvmusic 2 said:
> 
> 
> > I can't decide what chassis i need to use these  amp that i'am building is top heavy those tranny's are heavy plus i might put in another transformer for the 12V tube heaters so i can drive 6.3V-12.6V tubes flexible amp i might say.I will PM you anytime i need your help,Thanks again!
> ...


 
 For me getting those copper/aluminum plate are easy finding the time to work on the amp is more difficult,busy at work plus family so yeah this will take some time.Luckily i have the CRACK to enjoy!


----------



## Paladin79

i luvmusic 2 said:


> For me getting those copper/aluminum plate are easy finding the time to work on the amp is more difficult,busy at work plus family so yeah this will take some time.Luckily i have the CRACK to enjoy!


 
 I have been pretty busy so I am rushing through the electronics a bit but cutting the copper was my biggest holdup. I need to get the cabinets before I proceed. 
  
 You may have been the one who asked me what kind of copper I got. I know nothing about copper and even less about how to cut it well lol. The square opening for my transformer is a bit crooked but luckily there is some wiggle room there and it is covered well by the part.


----------



## i luvmusic 2

paladin79 said:


> i luvmusic 2 said:
> 
> 
> > For me getting those copper/aluminum plate are easy finding the time to work on the amp is more difficult,busy at work plus family so yeah this will take some time.Luckily i have the CRACK to enjoy!
> ...


 
 I might just buy a Hammond steel chassis they are sturdy have used a few of them but they are PITA to drill holes will see.


----------



## i luvmusic 2

On a side note a lot guys painted their top plate to get the patina effect but nothing compares to the real thing like what you did with yours Paladin79.


----------



## Paladin79

You sound like an experienced builder and I am sure you will make the right choices. i speeded up my process by using the same size top plate as the original. After the two Cracks I will probably move on to the Mainline and some of the other DIY amps out there. It is a relaxing hobby.


----------



## buke9

Argh just fired it up and I have problems. With volume all the off it plays fairly loud on the right side and increasing the volume it goes down and the gets all over the place and then right goes out and left is loud. I've checked my wiring and it looks good. I think it might be a bad pot. My diodes and caps are right .


----------



## buke9

The tubes are fine as I have another Crack to test them out of just saying.


----------



## Paladin79

All tests were ok before you fired it up? I have an extra Alps 100k dual gang if you need me to send it. Definitely check the wiring at the switch carefully and you have another crack you can compare of course. Those pots are easy to test with an ohmmeter and it would be a little strange for both elements to be bad.


----------



## i luvmusic 2

paladin79 said:


> You sound like an experienced builder and I am sure you will make the right choices. i speeded up my process by using the same size top plate as the original. After the two Cracks I will probably move on to the Mainline and some of the other DIY amps out there. It is a relaxing hobby.


 
  No not at all,What it gets me doing diy is when i had a spare time bought a Littledot MK III and start modding it then i found the Bottlhead that was it i'am hook,It is not long ago i been to this audio hobby.I used to play with engine and wheels(EXPENSIVE )...


----------



## buke9

After rechecking again somehow what I thought was a black wire was a white one I inadvertently burned. It made contact with the black wire. I did this at 1 in the morning so it was my bad and stupid. Pulled the wire up and all is good. I just got in too much of a hurry. Going to replace them and everything should be fine. Thanks for your offer Tom.


----------



## Paladin79

buke9 said:


> After rechecking again somehow what I thought was a black wire was a white one I inadvertently burned. It made contact with the black wire. I did this at 1 in the morning so it was my bad and stupid. Pulled the wire up and all is good. I just got in too much of a hurry. Going to replace them and everything should be fine. Thanks for your offer Tom.


 
 Np, I have seen pots like that get noisy but they are rarely bad out of the box lol.  Glad you found it now enjoy your amp!


----------



## buke9

paladin79 said:


> Np, I have seen pots like that get noisy but they are rarely bad out of the box lol.  Glad you found it now enjoy your amp!


Yeah just was working too late and too tired. Stupid of me just was having fun. No biggy though it will be fixed in short order and then the Speedball. The other Crack is wired a bit differently the transformer must be different. Well back at the task at hand thanks for the support.


----------



## Paladin79

buke9 said:


> Yeah just was working too late and too tired. Stupid of me just was having fun. No biggy though it will be fixed in short order and then the Speedball. The other Crack is wired a bit differently the transformer must be different. Well back at the task at hand thanks for the support.


 
 Yeah I have the older version also. Neither have the speedball yet but I want to test one against the other as I build the modified one, I will add it to one and make sure i like it before putting it in the second.
  
 I have some plans for the vent opening on mine, one would be a rotating finned disk that moved with increased heat but finding something the perfect size is not easy and i do not want to run the risk of it making noise. That is only my second choice, my first choice has no moving parts but would look cool.


----------



## MIKELAP

paladin79 said:


> i luvmusic 2 said:
> 
> 
> > For me getting those copper/aluminum plate are easy finding the time to work on the amp is more difficult,busy at work plus family so yeah this will take some time.Luckily i have the CRACK to enjoy!
> ...


 
 When cutting copper you need to use somekind of oil based coolant mixture to prevent from sticking and jamming and altogether  will make a nicer cut .


----------



## Paladin79

I appreciate the info, one of my employees mentioned that. I will look into it before I take on the second set of plates. I figured with the round holes and drill press it would get pretty messy but that is part of it I suppose. I did stop several times to let the metal cool. Anything that conducts electricity well also conducts heat well.


----------



## Timoteo80

I'm loving this thread...very interesting & seeing the different aesthetic styles is cool too. Having already built my own Crack I can understand & appreciate some of the comments made. Thx guys for documenting your diy projects here. It's one of the few things I like to check out on my phone periodically. This patined copper is out there bud rad! (Yeah I said rad...)


----------



## Paladin79

Thanks for the kind words. It will be a week or so before I will have done more work on this. I need to get busy on the matching headphones and headphone stand but I doubt they belong in this thread. Maybe just one photo when all parts are done. Heck my wife was impressed with the looks of the amp so far and she has little interest in the hobby otherwise lol.


This is fun to play around with so before I am done I may build several of these amps. My son is more interested in a Mainline so I will probably grab a couple of those and do mods as well. 

Tom


----------



## Tom-s

Matching headphones and stands do belong in this thread. So does a matching Mainline! Keep us updated!


----------



## Paladin79

tom-s said:


> Matching headphones and stands do belong in this thread. So does a matching Mainline! Keep us updated!


 

 Thanks Tom, I always feel like I am talking to myself when I see your name. My first name is Tom and my last name begins with S. That is my handle on several of the book groups with which I associate.
  
 Anyway right now I am in pursuit of a box full of brass pressure gauges I heard about. Such things as watch mechanisms and gears also lend themselves to steampunk. I love learning new things so now I am working on my copper cutting skills.


----------



## wolfmath

I just finished building my Crack and it sounds awesome with my HD 650's! I'll be attaching the Speedball soon, but I think I'll wait on that. 

One issue that I've noticed is that the volume is _very_ unbalanced at low levels. Does anybody else have that problem, or is that just my unit? I'm guessing the problem lies with the potentiometer...


----------



## Tom-s

Finally found my way around the new website. But hate it much and probably can't find this again thread after this reply.

Anyways, it's a normal thing with the stock volume pot. To get more out of it, look up the FAQ #3 mod on the Bottlehead forum.


----------



## Paladin79

I might be wrong on this but I measured one of the stock pots the other day and it did not measure like an audio taper (logarithmic taper) pot to me, more like a linear taper, it is one of the first things I replaced on the amp I am currently building. I could not find many markings on it to determine who made it but I will have others on both of my Crack builds soon.


----------



## silvrr

Has anyone seen any good instructions of the FAQ #3 mod for the resistors on the input or for the choke on the power supply circuit? Pretty sure I understand them, however, wouldn't mind having a go-by or something to reference off of.


----------



## Tom-s

The FAQ #3 instructions:
Disconnect the white wire at the pot that originated at the left RCA jack.  Install a 75K resistor between this wire and where it connected on the pot.  
Repeat this step for the red wire coming from the right RCA jack.
Attach and solder one 33K resistor between each outer pair of lugs on each level of the volume pot.
Resistor wattage is unimportant, 1/10 Watt or greater will work nicely.

For the Choke, remove powersupply resistor (either one is fine, but most remove the first), and replace with the choke. It's not directional. 

Don't have any pictures for you as i build in the FAQ on a VALAB pot (not the stock) and used a pair of chokes vs only one in my PS.


----------



## Timoteo80

Congrats on your Crack. I agree with waiting on the SB upgrade. I did the same thing. In fact I've had my Crack on daily listening & STILL have not added the SB. In fact it's been sitting on the shelf waiting to be installed for a few months. I MIGHT start assembling it tonight if I find some time. The wife is in the garden, so I have the house to myself, kinda nice lol.

The stock Crack is so pleasing with my HD600s that I've just been loving it as is. Hoping I hear a pleasing improvement with the SB. Some claim to like the Crack without. We'll see what side of the fence I'm on soon.


----------



## Timoteo80

Oh and I too have some slight channel imbalance on the Crack's pot but it's very minor & only at the lowest of volumes. You may want to consider upgrading your volume pot if it's as bad as you mentioned. Good luck bro!!

*Digging the look of the new site*


----------



## LikeABell

Paladin79 said:


> Thanks for the kind words. It will be a week or so before I will have done more work on this. I need to get busy on the matching headphones and headphone stand but I doubt they belong in this thread. Maybe just one photo when all parts are done. Heck my wife was impressed with the looks of the amp so far and she has little interest in the hobby otherwise lol.
> 
> 
> This is fun to play around with so before I am done I may build several of these amps. My son is more interested in a Mainline so I will probably grab a couple of those and do mods as well.
> ...


You're in luck! The Mainline is on sale right now.


----------



## Paladin79

I will have to check it out, thanks!

Unfortunately other work may keep me from doing much with my Crack mods this weekend. I am waiting to get the cabinets so I can cut all my cables the proper lengths.


----------



## Paladin79




----------



## i luvmusic 2

Paladin79 said:


>


WOW I'am drooling!Where did you get those VU meters(you posted before)?I'am thinking of putting one in my own DIY amp.Thanks!


----------



## Paladin79 (Apr 30, 2017)

I ordered one set from Ebay and another set from Amazon.

https://www.amazon.com/Nobsound-Aud...UTF8&qid=1493556662&sr=8-1&keywords=vu+meters

http://www.ebay.com/itm/291589607698?_trksid=p2060353.m1438.l2649&ssPageName=STRK:MEBIDX:IT

They are cheaper on Ebay but coming out of China there is a long wait. They are also a little tricky to deal with if you do not understand the electronics involved. The instructions are very lacking but I was able to figure them out. If you get one or two and need help, PM me and I will help where I can.

Tom


----------



## i luvmusic 2

Paladin79 said:


> I ordered one set from Ebay and another set from Amazon.
> 
> https://www.amazon.com/Nobsound-Aud...UTF8&qid=1493556662&sr=8-1&keywords=vu+meters
> 
> ...


Ok Thanks!


----------



## Aradea

Anyone here currently uses their Crack to drive the HD 800?


----------



## deserat

Aradea said:


> Anyone here currently uses their Crack to drive the HD 800?



Yup.  Doesn't push the HD800 to it's best but it's fun. I like the Crack with all it's flaws better than my HDVA600  ... In it's price range I've not heard anything better for the HD800.  ( though I've not heard the Valhalla or Woo Amp OTL amps ).  If  you feel the HD800 has weak bass the crack will change your mind.

Anything beyond that you wanna know?


----------



## Allanmarcus

I too use it with an 800. Lush tubes help


----------



## DavidA

Aradea said:


> Anyone here currently uses their Crack to drive the HD 800?



Another HD800 / BH Crack user here, as @Allanmarcus noted lush / warm tubes do sound better


----------



## adydula

"lush tubes....."

What specification do I need to look at to determine what tubes are "lush'?

Alex


----------



## timind (Apr 30, 2017)

I finished this Crack about a month ago. The speedball was put in yesterday and I'm not sure I like it better than stock. We'll listen for a while to determine.

This one has the ALPs blue velvet pot installed. Also, I used some left over 20 gauge Audioquest wire for all wiring in the signal path. I figured the copper wire should be an improvement. It was stripped out of an extra length of AQ Type 8 speaker cable. Only issue with the AQ cable is, it doesn't match the color of wire supplied with kit.


----------



## Paladin79

I will be using a lot of shielded twisted pair in my builds, I can see where 20 awg is important in certain parts of the amp and it allowed BH to stick to one size for the kit so that part makes sense. Since I am building two i will be able to switch back and forth between one without the speedball and one with. Otherwise it would be a tough to judge IMHO.


----------



## Allanmarcus

adydula said:


> "lush tubes....."
> 
> What specification do I need to look at to determine what tubes are "lush'?
> 
> Alex



there is no "spec" for that. Listening to tubes is the best way to determine for yourselves, but that is not always possible. The next best way is to read reviews. There are some here and others on the web. Google:
"crack tube rolling review friends"
I cannot post a like to the first hit, but it's a good thread on tubes for the Crack.

After reviews, some listening, and some questions, I ended up with this combo:
Mullard 12AU7 (Blackburn factory, Great Britain, code Gf1 84DX), Catham 6080


----------



## Tom-s

Allanmarcus said:


> I ended up with this combo:
> Mullard 12AU7 (Blackburn factory, Great Britain, code Gf1 84DX), Catham 6080



Good choice! Really like these. The 8 is actually a B (the factory code of Mullard Blackburn).

Interested in more comments on HD800 with Crack .


----------



## Allanmarcus

Tom-s said:


> Good choice! Really like these. The 8 is actually a B (the factory code of Mullard Blackburn).
> 
> Interested in more comments on HD800 with Crack .



Thanks! So my description should be:

Mullard 12AU7 (Blackburn factory, Great Britain, code Gf1 B4DX), Catham 6080

???


----------



## Tom-s

Allanmarcus said:


> Thanks! So my description should be:
> 
> Mullard 12AU7 (Blackburn factory, Great Britain, code Gf1 B4DX), Catham 6080
> 
> ???




I can't place the X on the end, Philips tube code is as follows:

Gf1    B4DX
TTC  FYMW

TT = Tube Type = Gf = ECC82/12au7
C= Change code? = Old code, in my collection only Gf1 and Gf2's are present.
F= Factory = B = Blackburn
Y= Year = 4 = 1964, 1974 etc
M= Month = D =  April
W= Week = 1, 2, 3 etc.

I've searched my collection (+-25 Blackburn ECC82's) for the X, but can't find any.
They do use different coding for some ECC82's code like k61, B61 for the dual getter tall plates.


----------



## Paladin79

I will have to watch for a Chatham 6080, is that not a division of Tung Sol? I know I have seen some while searching that say Sylvania and Tung Sol as well.


----------



## Aradea

Ah this new head-fi is giving me headaches.. I cannot seem to quote.

@deserat: yeah I own a standard crack. I'm loving it with my HD 650 and DT880..
But with my HD 800.. as you said, it does not push the 800s to the maximum. It just sounded fine..
Will modding the crack helps? I am relunctant to part with it


----------



## Timoteo80

Well...finally installed the Speedball upgrade to my Crack after sitting on it for about 4 months. I've been enjoying the standard Crack & wanted to get used to its signature first.

Yesterday I got an itch to install it & finished in about 4hrs. I really took my time & enjoyed the build making sure each solder looked nice & followed every step to a T. It fired right up last night on first attempt. It was late tho & I wanted a fresh approach to first hearing it so I went to bed BEFORE giving it a listen. Woke up about 30min earlier than normal before work & got a small listening session in this morning.

First thing I noticed was the darker background everyone talks about. Details had more "air" to them & just like Bottlehead describes, everything "tightened up". I'll post more of my thoughts later after I get a hold on it's new signature. Just wanted to post my initial thoughts.


----------



## Allanmarcus

Paladin79 said:


> I will have to watch for a Chatham 6080, is that not a division of Tung Sol? I know I have seen some while searching that say Sylvania and Tung Sol as well.



Yes, catham or tung-sol 6080 or 6080WA. From reviews I read, only the tung-sol/Catham's are worth getting.


----------



## Paladin79

I have been on the lookout for some but have yet to catch a deal. I used to know some people who dealt in tubes from the 60's and such, eventually I will lay my hands on some since people speak so highly of them.


----------



## deserat

@deserat:  I'm loving it with my HD 650 and DT880..
But with my HD 800.. as you said, it does not push the 800s to the maximum. It just sounded fine..
Will modding the crack helps? I am relunctant to part with it[/QUOTE]

There are alot of mods you can make to the Crack that improve SQ. Some of the more popular are:

Speedball
Roll Tubes.
Choke the power supply.
Better Pot or a Stepped attenuator.
Upgrade Capacitors. 

From reading alot of posts on the subject, it seems you can increase the SQ quite a bit. But you're likely to end up spending more money over time than buying or building a crackatwoa or mainline.  Granted it's not always about the money, it's often about having built something totally custom. I choked mine, run better tubes, and put a pkd pot in it, the choke was the least expensive upgrade, and it does yield noticeable results, the only tough part is where to put the choke.

There are alot of Crack build posts out there, this thread has serveral, https://www.head-fi.org/f/threads/b...-comparison-thread-crack-sex-mainline.683012/ does as well. The Bottlehead forums have alot of god discussion as well.


----------



## Paladin79

I am not familiar with PKD pots but I have tried TKD  I am a bit of a sci-fi buff so the only PKD I know of wrote the book the Bladerunner is based on: Philip K. Dick....Do Androids Dream of Electric Sheep. Your advice is sound.

Personally I do not mind upgrading the Crack and I am doing electronic as well as aesthetic upgrades. I am building two Cracks and the upgrades I do to either should pay dividends towards the one I keep. It may not be the best approach, but I am happy with my approach. Down the road I may add a Mainline and mod it to match the Crack, and the headphone rack, and headphones I am modding for my build.


----------



## deserat

Paladin79 said:


> I am not familiar with PKD pots but I have tried TKD  I am a bit of a sci-fi buff so the only PKD I know of wrote the book the Bladerunner is based on: Philip K. Dick....Do Androids Dream of Electric Sheep. Your advice is sound.
> 
> Personally I do not mind upgrading the Crack and I am doing electronic as well as aesthetic upgrades. I am building two Cracks and the upgrades I do to either should pay dividends towards the one I keep. It may not be the best approach, but I am happy with my approach. Down the road I may add a Mainline and mod it to match the Crack, and the headphone rack, and headphones I am modding for my build.



LOL you'll have to forgive me I must've been hallucinating a world in which my volume pot controlled my resistance to reality!  Am a PKD fan... yes I meant TKD.


----------



## Paladin79

No harm intended and your advice was most solid! I found some NOS Alps single ganged pots that are obviously segmented but just a bit large for my application. I may use them in another upgrade. It's been years since I studied tube theory so I wanted to start small with the Crack. I am trying to impress some sci-fi friends with my steampunk build... all sorts of clockwork gears, blade switches, copper and brass, pressure gauges etc.


----------



## HiddenFatKid

So I've pretty much decided to get the crack, and later add the speedball upgrade, with hopefully either a tung sol 5998 or a chatham 2399 tube and gold lion tubes. Before building the crack, is there any parts that i should upgrade before building (like better caps, a stepped attenuator, pots,  stuff like that?) the crack so i dont have to take it apart later to do it? Links would be awesome!  

Also would it be possible to add a decibel guage on the crack (like the ones used on the front of McIntosh Amps? I feel like that'd be looking pretty snazzy.

I'm planning on using the crack with my HD600's, and hopefully eventually HD800's. What are some good closed back cans that work with the crack, besides Beyerdynamic Cans, or the ZMF Eikon, are there any other options?


----------



## Tom-s

The Bottlehead team always suggest to build the amp completely standard first. This to make troubleshooting more easy.

If you'd want to upgrade one thing from the start (because it's a pain later on), then this would be silver(plated) wiring for the signal pathway.


----------



## Paladin79

You have to build the amp completely even if you plan on doing the speedball upgrade. I guess it is good to know if you like the difference. I really do not think it too bad to install a different pot or capacitors. You will be changing a lot of things if you do the speedball though. The VU meter or meters are just add on devices. Personally I am having bigger cabinets made so I will have room for more and more upgrades if I so desire.


----------



## larcenasb

I envy all of you who've stocked up on 5998s, the struggle is real-ly annoying right now lol. Feelin' like a dinosaur hunter out here...


----------



## Jimmy24

Do 6DJ8 tubes work with Crack or do I need to modify it?


----------



## Allanmarcus

Check here http://bottlehead.com/smf/index.php?topic=663.0 for what tubes to use with the crack.


----------



## Paladin79

Thanks for the link, I am trying for some Mullard 12au7's from 1961. I have personal reasons for searching for those marked Webcor (made by Mullard).


----------



## HiddenFatKid

Paladin79 said:


> You have to build the amp completely even if you plan on doing the speedball upgrade. I guess it is good to know if you like the difference. I really do not think it too bad to install a different pot or capacitors. You will be changing a lot of things if you do the speedball though. The VU meter or meters are just add on devices. Personally I am having bigger cabinets made so I will have room for more and more upgrades if I so desire.


I don't think i'll change too much, a VU meter would just be for aesthetics most likely, do you have any pots or capacitors in mind?


----------



## Paladin79 (May 6, 2017)

I am using Alps pots but they are single gang, I want individual adjustment on each channel. I will most likely use Mundorf EVO caps but I have not purchased them yet. Those and a choke are something I will consider after all shielding and cosmetics are done.  The VU meters will add to the steampunk look I am going for. One set was $20 so they are not an outrageously expensive add on and cutting the holes for those was probably the easiest thing I have done so far. I am changing out the 1/4 inch jack with one that has a brass alloy top, all visible parts will be gold, copper or brass on my build. Maybe a bit of silver in some moving gears, they are a little hard to paint.


 ar the 1.  The one I keep will be more elaborate than the one I sell but they will be of similar design.


----------



## JamieMcC

Paladin79 said:


> I am using Alps pots but they are single gang, I want individual adjustment on each channel. I will most likely use Mundorf EVO caps but I have not purchased them yet. Those and a choke are something I will consider after all shielding and cosmetics are done.  The VU meters will add to the steampunk look I am going for. One set was $20 so they are not an outrageously expensive add on and cutting the holes for those was probably the easiest thing I have done so far. I am changing out the 1/4 inch jack with one that has a brass alloy top, all visible parts will be gold, copper or brass on my build. Maybe a bit of silver in some moving gears, they are a little hard to paint. ar the 1.  The one I keep will be more elaborate than the one I sell but they will be of similar design.



Really impressed by the patina you have achieved the blues that have come through look great.


----------



## Paladin79 (May 7, 2017)

Thanks, I could have gone for green with a different chemical makeup. This was easy to do, sea salt, ammonia and clean copper is all you need.  White vinegar and sea salt for a green appearance as I recall. They sat over night and I put a clear finish on them early the next day. I will use the same treatment on a headphone stand made with copper pipe on a copper and oak base. The headphones i am building will come close to the look I want to achieve.

My thanks to Allanmarcus for the mention of mesh material I could use for some steampunk inspired headphones to go with my Crack builds. This is an office pencil holder with mesh cut out for protection of some open headphones that were previously closed. I am not quite done with them but they are usable and final cost is around $60. They sound amazingly similar to Beyerdynamics.


----------



## larcenasb

Tidied up the underside of my amp and also, finally -- much to my begrudgment -- bought myself a Tung-Sol 5998 for a semi-sane price. No more boxes to tick for this set-up. After three years, I'm done!

Overall, the sound now coming out of my AKG K240 Sextetts is big -- and I mean big! -- even at low-volume-level listening. I suppose that's what is meant by "headroom". The Tung-Sol really took that to another level, after the Speedball did likewise from early on in my audio journey. So, I'd say big, detailed, effortless, unrestricted, slightly warm, and most of all: emotionally engaging and satisfying. The Bottlehead amp has been such a learning experience, and even if I upgrade to more expensive gear way in the future, I can never let go of this both as a passion project and as an excellent communicator of emotions and mindscapes. Happy listening!


----------



## hawkwindx (May 9, 2017)

Nice looking amp, larcenasb. 

I understand your "begrudgment". I may some day spring for a Tung-Sol 5998 but I haven't been lucky enough to find one for a decent price.

I've read a whole lot about tube rolling for the crack, including the above link to the bottlehead site. A lot of that information is a few years old now. 

Has anyone found any inexpensive output tubes as an alternative to the Tung-Sol 5998?


----------



## Allanmarcus

hawkwindx said:


> Has anyone found any inexpensive output tubes as an alternative to the Tung-Sol 5998?



Tung-sol or Chatham 6080. Some, myself included, think it's better.


----------



## Paladin79

As luck would have it I listened to the Chatham 6080 some last night and so far I really like the outcome.
 I also stopped by a distributor this morn whose company has been around since the tube days and they told me to try Tubesandmore. They said they know the value of the tubes so if nothing else they can be used for price references as you shop around. They do carry some reissue Tung Sol that are made in Russia but I still prefer looking for NOS.


----------



## Paladin79 (May 9, 2017)

larcenasb said:


> Tidied up the underside of my amp and also, finally -- much to my begrudgment -- bought myself a Tung-Sol 5998 for a semi-sane price. No more boxes to tick for this set-up. After three years, I'm done!
> 
> Overall, the sound now coming out of my AKG K240 Sextetts is big -- and I mean big! -- even at low-volume-level listening. I suppose that's what is meant by "headroom". The Tung-Sol really took that to another level, after the Speedball did likewise from early on in my audio journey. So, I'd say big, detailed, effortless, unrestricted, slightly warm, and most of all: emotionally engaging and satisfying. The Bottlehead amp has been such a learning experience, and even if I upgrade to more expensive gear way in the future, I can never let go of this both as a passion project and as an excellent communicator of emotions and mindscapes. Happy listening!


What is the impedance of the AKG's? I have found some k240's that are around 52 ohm impedance and obviously they make a few models.
Good job with the build by the way. It looks like you have gone with Alps pot, choke, caps, different power switch obviously, and possibly a Canare 1/4 inch plug on the headphone cable.

thanks
Tom


----------



## larcenasb

hawkwindx said:


> Nice looking amp, larcenasb.
> 
> Has anyone found any inexpensive output tubes as an alternative to the Tung-Sol 5998?



Thank you!

I could be very happy with my RCA 6AS7G, and surely will be once my 5998 tubes die. The RCAs can be had for only $15 each, and while the 5998 is spectacularly holographic with a big soundscape around my head, the RCA isn't far behind and is ahead of my Sylvania Gold Brand 6080 in terms of holography. To give out some courtesy points, the Sylvania does have a beautiful, cozy tone that is much more graceful than my dry and unsure-of-itself RCA 6080. It's just hard to go back to a closed-in sound for me after having heard the open expansiveness of the Tung-Sol 5998 and RCA 6AS7G. So, the RCA 6AS7G isn't as open, dynamic, or holographic as the 5998 but it also isn't six times less so, as the prices are... More like 1.5 times less so.



Paladin79 said:


> What is the impedance of the AKG's? I have found some k240's that are around 52 ohm impedance and obviously they make a few models.
> Good job with the build by the way. It looks like you have gone with Alps pot, choke, caps, different power switch obviously, and possibly a Canare 1/4 inch plug on the headphone cable.
> 
> thanks
> Tom



Hi, my AKGs are the vintage K240 Sextett model, which are 600 ohms. The K240 Sextett (six passive radiators), K240M (Monitor), and K240DF (diffuse-field equalized/radio station reference) are all vintage 600 ohm models. The K240 "Studio" is the new-production 55 ohm model. I used to have the Studio and they sounded okay, but the musicality of the Sextetts sets them apart, similar I'd say to new production vs NOS tubes.
And thank you! Correct on all observations! And yes, that is a Canare 1/4" plug, I really like the quality and reasonable prices of Canare, along with Rean, Mogami, and Belden for DIY cabling. Cheers!


----------



## Paladin79 (May 11, 2017)

They sound like great vintage headphones. I have used plenty of Canare cable and connectors as well as all others mentioned. Belden's factory is just north of me and I love to use their product whenever possible.

Great advice on the tubes as well!

Ok after spending some time listening to a basic Crack amp with no speedball and very few upgrades other than the Chatham 6080WA I am pretty impressed with the capabilities of the amp and may well end up keeping one for home and one for my office. Right now i am just using a PONO player loaded with binaural plus recordings as a source and I could live with hauling that to work as needed.

I am now trying some Mullard 12Au7's, I have four versions but it is a little early to have a preference.


----------



## hawkwindx

Always interesting to hear people's reactions to the tubes. There are so many variations that it's a gamble when buying them. After I install the Speedball I'll try out the E80CC's. 

In the meantime the tubes that came with the Crack sound outstanding!


----------



## larcenasb (May 15, 2017)

Ahhh, it's so frustrating! You hear about other people's opinions on different tubes in the Crack, they say: "I like the RCA 12AU7 clear top for it's far-reaching highs," or "I prefer 6SN7s for their rounded tone," and you think it's all preference; purely subjective. But then, the more you read, you start to notice a prevailing consensus amid all this: "The Tung-Sol 6SN7GT RP is the holy grail," "So pure!" "So organic!" "Nothing sounds as right!" So, I, hoping a tube so expensive isn't my preference, buy a low-testing one for cheap, hoping I'll prove to myself that it isn't for me and that I'm lucky to save so much money. But then, no matter how hard you try to encourage the placebo effect and make yourself believe the tube is flawed or ill-suited for your tastes, you sigh in the face of the evidence or your dopamine and goosebumps, and realize it's the best you've heard. -_-


----------



## Paladin79

There are a lot of Russian reissues on Ebay of the 6SN7GT tubes. Has anyone tried those? Naturally I do not expect the same results but are they any where near a viable alternative?


----------



## Tom-s

I only have the 1578 Melz tube with the shiny plates with holes. And that one sure sings!


----------



## Paladin79 (May 16, 2017)

Luckily I have two Crack amps so I should have an easier time comparing one tube to another. I have a few more choices on the way but I had not heard of the Melz yet. (Russian no doubt) Some day I will have time for some research.


----------



## attmci

Paladin79 said:


> There are a lot of Russian reissues on Ebay of the 6SN7GT tubes. Has anyone tried those? Naturally I do not expect the same results but are they any where near a viable alternative?



I recommend that you should try a "cheap" NU black glass 6SN7GT first. Just my 2c.


----------



## Paladin79

I did find a couple 6SN7GT Tung Sols to try out, they are on the way. They were not exactly cheap but they were not $150 each any way. I also found some 1578 Melz that were reasonable but shipped from Russia, I may get some of those to try out at a later time. Soon I will need to spend some time on finishing the cabinets for my Crack amps and building a headphone rack to match.


----------



## LikeABell

Paladin79 said:


> I did find a couple 6SN7GT Tung Sols to try out, they are on the way. They were not exactly cheap but they were not $150 each any way. I also found some 1578 Melz that were reasonable but shipped from Russia, I may get some of those to try out at a later time. Soon I will need to spend some time on finishing the cabinets for my Crack amps and building a headphone rack to match.


Well well.. Someone's bitten by the tube rolling bug!


----------



## Paladin79 (May 17, 2017)

It beats being bitten by fleas, mosquitoes or chiggers I would think.

Since I will be keeping one Crack and probably selling the other, I figured a few extra tubes might sweeten the deal for anyone interested in the amp. I am already planning major modifications in the Steampunk style as well as electronic upgrades and added features. VU meters, dual pots, etc.

Obviously I will keep the tubes I like the best but I am ordering two of some things.


----------



## i luvmusic 2

In this hobby their is a lot of snake oil,Just listened to your music  and enjoy what you have.


----------



## Paladin79

I certainly understand snake oil but the way some of these tubes are appreciating in value I have considered putting some away as an investment.
I envision my grandkids one day opening a safety deposit box to find tubes and a note from me saying not to sell these unless they double check the going price on Ebay. They then turn to each other and ask what an Ebay is and why had I not invested in gold or baseball cards or something of value????

I did try a Tung Sol 6080 and IMHO there was a pretty good difference between it and the original tube but it is only an opinion. Since arguments should be based on facts and not opinions, it is never an easy thing to argue what a person might hear or not hear in any kind of audio equipment.


----------



## i luvmusic 2 (May 17, 2017)

I'am wondering how much a CRACK amp go for this days,I'am planning to sale mine.


----------



## Paladin79

With your upgrades I would think yours could fetch at least $700 or more but that is just an educated guess. Personally I would throw it on ebay with a reserve and see what happened. The ones that ask for a Buy It Now of $800 or more are still sitting there. Something is only worth what someone is willing to pay for it. (Pubilius Syrus) No matter what, keep me informed, you can post it for sale here and on Ebay of course but you know all of that. I have the attitude that if my second Crack does not sell, I will give it to my son as a gift or just use it in my office.

 I am not sure if Head-fi would allow it but what might be cool is to try to raffle one off at say $25 a ticket. Assign each ticket a four digit number and then announce a lottery on a certain date that would be the basis for the winning number, closest person to the number with their ticket wins.  (using only the last four digits.) Maybe allow each person to select their own four digit number or numbers before said lottery. I am just thinking out loud but at $25 per, you need only sell 32 tickets to hit $800.  Maybe even get a second party to handle the raffle so there is no question it is on the up and up. Have that person handle the money and once the winner received the Crack, send the money on to you. Make it as clear cut and honest as possible and I would buy a couple tickets myself (if it is allowed by Head-fi of course.)

Tom


----------



## Allanmarcus

I will end up selling mine, which is built well and has a few minor upgrades and some good tubes, for $500. Head-fi rules don't allow selling DIY items for more than the cost of parts and/or actual paid labor costs, so if you want to get reimbursed for your own labor, you'll have to sell it on audiomart, audiogon, ebay, or elsewhere.


----------



## Paladin79

Yeah I seem to recall reading that therefore placed a couple caveats in my post. Any Cracks being sold in the classifieds would hopefully fall into that category.

 In my case I am paying a guy to build a new cabinet and there will be only a handful of stock parts left when I am done. Mine will be built, and rebuilt...well.  It would be a little tricky to do an audit on some of my parts so chances are I will sell my extra one on Ebay anyway if I do sell it.


----------



## i luvmusic 2

Paladin79 your ideas are all great i think i will ask my wife if she want it if not it will be for sale but i won't take less than $699.99 US that is,not canadian Peso.Thanks!


----------



## Paladin79

I was just goofing around with the raffle idea but once I said it, I tried to think through it logically. You have probably said it but is that a Tung Sol Sylvania tube you have in there? You no doubt have invested in different components that bring value to the amp. 

You can always set up more than one listening station but then I am someone who has has as many as five sound systems in a house at one time so my advice may not be the best lol.


----------



## i luvmusic 2 (May 18, 2017)

I should have let her listened 





Paladin79 said:


> I was just goofing around with the raffle idea but once I said it, I tried to think through it logically. You have probably said it but is that a Tung Sol Sylvania tube you have in there? You no doubt have invested in different components that bring value to the amp.
> 
> You can always set up more than one listening station but then I am someone who has has as many as five sound systems in a house at one time so my advice may not be the best lol.



It's a Sylvania and ???? 6CG7 can't read the name of it,Two listening area is enough for me The wife is taking the amp and the headphone Darn it.I should have let her listened to RAP music not her favourite instrumental.


----------



## Paladin79 (May 19, 2017)

Years ago I built a bunch of Dynaco equipment including tube amps, now I wish I had them. You might be kicking yourself one day if you did sell the Crack amp.


----------



## hawkwindx

Showing off my recently finished Crack. Sounds good!


----------



## LikeABell

hawkwindx said:


> Showing off my recently finished Crack. Sounds good!


Do you have a pic with better lighting?


----------



## i luvmusic 2

I think he is trying to capture the tube glow,looks ok.


----------



## Paladin79 (May 21, 2017)

I should have my cabinet Monday and I still need to do some work on the patina of my headphone rack to match the Crack amp, but a few cosmetic things are starting to come together. 90% is patinated copper, brass or gold, very little silver except on headphones and solder joints. I left those a bit sloppy just for effect.


----------



## i luvmusic 2

WOW!That is beautiful...........


----------



## Paladin79

Thanks,
I need to work on the patina on the headphone rack, I got ready to patinize it and found my container was not large enough. I was also dealing with round objects that are very difficult to sprinkle with sea salt.
I ended up using a plastic trash can and water based sea salt in a sprayer. Right now the blue is a little overpowering. I need to fine tune a few things but I am getting there.


----------



## i luvmusic 2

Yeah i hate working on something then you get held back by little things you never think of,For example i'am  working on my Preamp  then i realized i'am missing a 250K resistor  now i have to stop and wait until Tuesday to get one.


----------



## Paladin79

I backed off on some  of the patina for the headphone rack. These are the cables I will use with the steampunk crack amp. Brass alloy headshells, gold plated RCA connectors, OFC coaxial cable.  I had to do serious mods on the connectors so they would fit the cable so these are pretty much one of a kind.


----------



## i luvmusic 2

But the cables are not cryo treated.....beautiful BTW.


----------



## Paladin79 (May 21, 2017)

if they were once cryo treated the heat from a brass brush on my grinding wheel negated that effect. They used to be black powder coated. I am listening to them now through a crack amp and they certainly did nothing to harm the sound.


----------



## Paladin79

A better view of the headphone rack and headphones modified to work with the Crack. I will finish oak in the rack to match the Crack amp case.


----------



## hawkwindx (May 21, 2017)

Paladin79 the amp looks great! Looking forward to seeing it finished.


----------



## Paladin79 (May 21, 2017)

Thanks, I am supposed to get a cabinet tomorrow for the various copper plates I have ready for it. In the meantime I am finishing up accessories. The electronics go quickly for me, the cosmetics take some time. A working knowledge of physics, chemistry and metallurgy helped.  It is fun to shop for plumbing supplies and to tell those wanting to help you that the project has nothing to do with water. Oh I plan on using blade switches somewhere on the amp, just now sure where yet but they look cool and I want them somewhat functional.


----------



## Allanmarcus

Paladin79 said:


> if they were once cryo treated the heat from a brass brush on my grinding wheel negated that effect. They used to be black powder coated. I am listening to them now through a crack amp and they certainly did nothing to harm the sound.


Throw 'em in the freezer overnight and call 'em cryo-treated!


----------



## Paladin79

I suspect that happens in some cases, especially if you are relying on someone off shore doing the process. I had heard of it being done some in the states but I have not researched it much. The less I say on such processes the better.


----------



## i luvmusic 2

Allanmarcus said:


> Throw 'em in the freezer overnight and call 'em cryo-treated!



You need to add SNAKE OIL so it's much effective.


----------



## Paladin79

I probably have an extra 50 or 60 feet of this particular coaxial cable. It requires a connector with at least an 8 mm opening though so it can be tricky to use. I figure for a connection from a DAC to the Crack amp it will not be moved much anyway, it is not super flexible. The way it solders and by the looks of the braid it may well be silver plated ofc copper. It does not have the look of normal tinned wire.


----------



## Paladin79 (May 23, 2017)

This may show it a bit, the wire is a real light color and shiny. Maybe it was just tinned with a ratio of silver solder.
  I did find the specs and this is low capacitance silver plated digital audio cable, 110 ohm.

I now have an oak cabinet in hand, will work on the oil and wax finish this weekend as well as finishing up some of the electronic mods on the crack build.


----------



## Paladin79 (May 23, 2017)

I have to apply oil and wax finish but the quartered oak cabinet is complete otherwise. You can see the size difference between this and the standard Crack down the bench. Rear has four inch plate as well. The oak is so pretty I may finish the inside. The tiger stripes will really pop when completed.

Tom


----------



## neddoge

That looks incredible!


----------



## Paladin79 (May 23, 2017)

Thanks, just wait till the cabinet is golden brown and it picks up the exposed copper in the plates. The patina should show better then as well.

I am building two amps in this vein, I am seriously thinking of using polished copper for the second amp, same dual volume controls, same VU meters, same cabinet.
Then it is just a matter of deciding on which one I want to keep. I can easily do a headphone rack in polished copper; I have plenty of extra room for mods.  I was aiming to install the headphone jack on the right side of the cabinet but I may have to think through that a bit before I drill the hole. The stripes will be glorious when completed. My son reminds me I need to beat up the cabinet to make it look old. This is nearly inch thick quartered oak, well seasoned. If I hit it with a chain, the chain might break first. The copper plate on top is two pounds, when completed this will be one heavy sweet sounding amp.


----------



## Paladin79




----------



## DavidA

@Paladin79, great craftsmanship


----------



## Paladin79 (May 24, 2017)

Thanks, one of my employees built the cabinet, I did all of the copper plate and design and will be altering some of the electronics.  I went with dual single ganged volume pots because on some music, I like to turn left or right channel up a bit but that is more of a personal preference. On the second one I make I may put a dual ganged Alps pot on the front plate with the headphone jack next to it. Adding patina is a lot easier than buffing out all the copper so I will have to see how things work out on my second build.


----------



## larcenasb (May 24, 2017)

Hi, some expert assistance needed please: Looking at my attached graph, it is not unreasonable at all to use 33uF output caps (I'm looking to get ClarityCap CSA 33uF 250V caps) with my AKG K240 Sextetts (600 ohms), right? I'm currently using Audyn Q4 68uF outputs and I notice no bass roll off from the stock 100uf electrolytics. I'm just trying to make my amp the best I can afford to make it.

My second question is: The graph shows output frequency at -3db, so with 33uF caps 8hz will be the limit with my cans before rolling off. Does this change with low volume level listening, meaning will it roll off sooner: 20hz, 30hz, 40hz?

Finally, I read from Paul Joppa, "I would never use less power supply capacitance (last cap) than in the output cap, and I'd prefer at least twice that - if it were my amp." I currently have 3 Audyn Q4 68uF caps (2 as outputs, 1 as the last PS cap), so if I buy the CSA 33uF caps, my Audyn 68uF would be fine as the last PS cap, doubling (just about) the outputs' capacitance. PAULLLL, SIRRRR, are you on head-fi!?!?!?! Can you (or anyone else that knows) please explain what the benefit is of the last PS cap doubling the outputs' capacitance? Does this affect the bass roll off? Thanks so much everyone. Have a good day. 

P.S. I have my Alps pot padded, does that have anything to do with the bass roll off, since I am actually turning the volume up much higher because of the extra resistance? Thanks!


----------



## i luvmusic 2

Paladin79 WOW!That is really pretty.


----------



## Paladin79 (May 27, 2017)

Thanks, it will look better once I apply finish to the cabinet and get the VU meters working, and change some electronics. Everything is progressing as I expected up to this point. Luckily I have two to build and can sell one, I doubt I will part with this one.


----------



## hawkwindx

Paladin79 said:


> I did find a couple 6SN7GT Tung Sols to try out, they are on the way. They were not exactly cheap but they were not $150 each any way. I also found some 1578 Melz that were reasonable but shipped from Russia, I may get some of those to try out at a later time. Soon I will need to spend some time on finishing the cabinets for my Crack amps and building a headphone rack to match.



Did you get a chance to listen to those 6SN7GT Tung Sols yet?


----------



## Paladin79

I did and in all honesty I preferred the Chatham 6080 (also Tung Sol I believe) it could be the age of the tubes I bought but the volume level was lower with those. Sound quality was decent but they did not push my modified headphones quite like the 6080.


----------



## attmci (May 27, 2017)

Paladin79 said:


> I did and in all honesty I preferred the Chatham 6080 (also Tung Sol I believe) it could be the age of the tubes I bought but the volume level was lower with those. Sound quality was decent but they did not push my modified headphones quite like the 6080.



Hi, Tom. I am a little bit confused. You use the TS 6SN7GT as driver or power tube?

PS Just found a couple your friends here also wanna to sale their Crack. LOL


----------



## Allanmarcus

attmci said:


> Hi, Tom. I am a little bit confused. You use the TS 6SN7GT as driver or power tube?
> 
> PS Just found a couple your friends here also wanna to sale their Crack. LOL



Interesting. Looks like the 6SN7GT can be used instead of the 12AU7, but requires mods to the crack.


----------



## Paladin79 (May 27, 2017)

I definitely used it for the power tube, it fits the octal socket and it is considerably smaller than the 6080. I just happened across a couple of these and grabbed them quickly without doing much research lol. Maybe you folks were talking about using them in place of the 12au7 and I missed that.

The tubes I ended up with are sized in between the 12Au7 and 6080, they are marked Tung Sol
6SN7GTB, I have a tendency to skim the posts quickly so I may well have missed important info about their usage.


----------



## Paladin79

attmci said:


> Hi, Tom. I am a little bit confused. You use the TS 6SN7GT as driver or power tube?
> 
> PS Just found a couple your friends here also wanna to sale their Crack. LOL



I know Allanmarcus mentioned selling his, I have two so I will either sell one or give it to my son. He is starting to like the looks of the one I am modifying and I have enough parts to do two. I have not done the Speedball upgrades yet but with the proper headphones I do like the way they sound.

Tom


----------



## attmci

Paladin79 said:


> I definitely used it for the power tube, it fits the octal socket and it is considerably smaller than the 6080. I just happened across a couple of these and grabbed them quickly without doing much research lol. Maybe you folks were talking about using them in place of the 12au7 and I missed that.
> 
> The tubes I ended up with are sized in between the 12Au7 and 6080, they are marked Tung Sol
> 6SN7GTB, I have a tendency to skim the posts quickly so I may well have missed important info about their usage.



Thanks for your quick response, Tom. 

Those >$150 TS 6SN7GT are round plate ones made in 1940s (WWII/black glass). By using a 6SN7-to-12AU7 adapter, they are wonderful driver tubes. In your second crack, not sure if you can mod it to be able to use both 6SN7 and 12au7 tubes (with switches). Someone had done that before.


----------



## attmci

Allanmarcus said:


> Interesting. Looks like the 6SN7GT can be used instead of the 12AU7, but requires mods to the crack.



No need to mod the crack, you can use a  6SN7-to-12au7 adapter.


----------



## Paladin79

Thanks for the info on the tubes, I have been in electronics long enough to know what I do not know and tubes are not my specialty lol. I studied them in college some but only worked with them briefly in hybrid tv's and Dynaco equipment years ago.  I did not pay $150 for these by any means and you have given me some good info. 

Tom


----------



## hawkwindx

This adapter has been recommended for a "6SN7-TO-12AU7-TUBE-SOCKET-ADAPTER"
http://www.ebay.com/itm/GARAGE1217-...APTER-OUTSTANDING-BUILD-QUALITY-/252576786494


----------



## Paladin79

Thanks Hawk!  I may grab one of those. Have you tried them and what changes in sound might I expect using one?

  I also see where there are some Tung Sol 6336's available on Ebay but they draw 5 amps. Anyone had experience with them or bad idea?

I need to locate the Bottlehead list of tubes again so I can more carefully check out what to try.


----------



## attmci (May 28, 2017)

Paladin79 said:


> Thanks Hawk!  I may grab one of those. Have you tried them and what changes in sound might I expect using one?
> 
> I also see where there are some Tung Sol 6336's available on Ebay but they draw 5 amps. Anyone had experience with them or bad idea?
> 
> I need to locate the Bottlehead list of tubes again so I can more carefully check out what to try.



Hi, Tom, I used that adapter. But the top 6SN7s are very expensive comparing to 12au7s.  

Here is a good reference:

http://www.fourwater.com/files/hist6sn7.txt

"
Another debate about plates is the plate material color.
The material color does not have any real impact on the performance
of the tube. While some argue that the black plates are better because
they can radiate heat more effectively, the reality is that the
tubes are not operated at a level where this would have any impact
on the performance of the tube. A better reason for paying attention
to the plate material used is to get an idea of who made the tube.
Black rectangular ribbed plates are most commonly found on RCA tubes
(although they produced rectangular gray and square gray plates as well).
Square plates are found in later (cheaper) constructed tubes, which
is why they usually don't command as high a price as the rectangular
or round plates. The round plates don't have as much maximum power
handling as the rectangular or square plates, but *the round plates 
have a more even distribution between the cathode, grid and plate which 
improves the amplification quality of the tube*." (leads to >$150 TS RP tubes,  )



The PT-3 power transformer can handle 3.5 amps of AC heating.

Not sure about the new PT-10 in your crack.


----------



## Paladin79

I have the newest version of the Crack (that I am customizing) as well as a 1.0 (I believe) that I built stock for comparison purposes. I will not risk it, I see those tubes going for $50 so I figured I had best ask.

I do not have the top 6sn7's by any means and I will probably stick with quality 12AU7's, 

Right now I am in the middle of wiring my VU meters and Alps pots with Molex plugs so I can reach under, disconnect anything I wish from front and back plate and pull the main plate of the amp. (mine has three copper plates.) Tedious stuff but when completed I will post a photo with lighted meters.


----------



## Allanmarcus

Paladin79 said:


> I need to locate the Bottlehead list of tubes again so I can more carefully check out what to try.



http://bottlehead.com/smf/index.php?topic=663.0


----------



## Paladin79 (May 28, 2017)

Thanks Allan, for some reason I have trouble accessing that site and the link really helps. 

 

The wood came out a little darker than intended but luckily I will be doing another cabinet and I think polished copper would fit this cabinet a bit better. With the system I have in place i can swap all three plates in a minute or two.

I finished the inside of the cabinet as well, the oak had such a nice grain it seemed a shame not to show it off a bit.


----------



## attmci

For new tube amp owners who are reading this thread, I have some suggestions:

1. Ignore the recommendations from the tube sellers.
2. Ignore the extremely positive comments from someone who just purchased a tube in the last couple of days.
3. Avoid impulse purchase and bidding wars.
4. Don't have to trust those "power sellers" on E--bay (i.e.  desiremexxxx). They sometimes sell weak tubes as NOS.
5. Choose the tube(s) you like most based on your own taste.
6. Good pair(s) of driver and power tubes will help you easily pass this test:
http://www.npr.org/sections/therecord/2015/06/02/411473508/how-well-can-you-hear-audio-quality

Enjoy!


----------



## hawkwindx

Thanks attmci, for the helpful information.

As for the article, thanks for that too! Really interesting. I would think with stock tubes on the crack one could hear a difference. I don't have the most expensive tubes or have the speedball added yet. I only got one of those correct. I really tried to listen for a difference even after knowing the answer.

When I've compared Spotify with my FLAC files I haven't been able to hear much if any difference.


----------



## Paladin79

Thanks so much for taking the time to offer such sound advice Attmci!

I listened to the quiz and missed the Mozart piano concerto but it was a good sound test. I believe i read once that a piano is the toughest instrument to capture as far as recording.

The Neil Young was the hardest for me with the selection they chose. I listen to that album a lot but that particular song is probably my least favorite.


----------



## i luvmusic 2

Paladin79 said:


> Thanks Allan, for some reason I have trouble accessing that site and the link really helps.  The wood came out a little darker than intended but luckily I will be doing another cabinet and I think polished copper would fit this cabinet a bit better. With the system I have in place i can swap all three plates in a minute or two.
> 
> I finished the inside of the cabinet as well, the oak had such a nice grain it seemed a shame not to show it off a bit.



That is a BEAUTY.....


----------



## Paladin79

Thanks, I hope to complete it one day lol. I keep getting sidetracked with work, work.

On a scale of one to ten I consider it an eight, my next one will be nicer. I have had friends hint about me building them one and I am not sure they know what a headphone amp does. 

I do have a couple Tung Sol 5998's headed my way and I may include one with the amp I do not keep.

Tom


----------



## i luvmusic 2

Not to bust your marbles but you realized you need to MOD the crack to run 5998's?More work for you....


----------



## Paladin79

damn, what now lol?  It is listed on the Bottlehead site as one of the tubes you can swap without modification unless I misread it.

I have not completed my build on the fancier crack amp I own so perhaps I can incorporate mods there if need be.


----------



## i luvmusic 2

I'am interested on how the VU meter connected into the amp.


----------



## i luvmusic 2

Paladin79 said:


> damn, what now lol?  It is listed on the Bottlehead site as one of the tubes you can swap without modification unless I misread it.
> 
> I have not completed my build on the fancier crack amp I own so perhaps I can incorporate mods there if need be.



Hey! I could be wrong it won't be the first time...


----------



## Paladin79 (May 29, 2017)

i luvmusic 2 said:


> I'am interested on how the VU meter connected into the amp.



I was always taught to connect such meters to the last stage before the speakers, for most of my testing i have had them hooked up to the 1/4 inch jack circuit with no ill affects. I did a lot of testing running them off the headphone jack of portable devices in order to get them tweeked in a bit. Does that help? They are mostly for show but I do like to make sure I am not pegging the needles unless I am beyond a comfortable listening level.


----------



## Paladin79

i luvmusic 2 said:


> Hey! I could be wrong it won't be the first time...



I have a feeling someone will jump in soon with the answer and you may well be correct.


----------



## i luvmusic 2

Paladin79 said:


> I was always taught to connect such meters to the last stage before the speakers, for most of my testing i have had them hooked up to the 1/4 inch jack circuit with no ill affects. I did a lot of testing running them off the headphone jack of portable devices in order to get them tweeked in a bit. Does that help?



I thought about that I might put mine in between the Preamp and Amp,Yes Thank You!


----------



## Paladin79 (May 29, 2017)

It really depends on the range of the meters in question. They are usually rated at a specific current range. I want to say these are 500 micro amp but do not hold me to that, it has been a long weekend and the technical portion of my brain is a bit frayed or fried. That should equate to .5 milliamps.


----------



## i luvmusic 2

I'am not trying used the VU meter for accurate measuring i just wan't it there for looks they do look cool.


----------



## Paladin79

I understand but it is nice if the meter works somewhat lol. You do not want the needle sitting there doing nothing, or pegging itself every time you turn the amp on. The type i am using has an adjustment range of 100 to 500 microamps, apply more current than that and you may be ruining the meter. If you get into trouble, you can always read up a bit on current limiting resistors and change the range of the meter slightly. Mine are functional, if you just want the lights glowing, you can do that as well.


----------



## i luvmusic 2

I agree the needle should show some movements and lighted that is all i want from that device doesn't need to be that accurate.Thanks!


----------



## Paladin79

LOL the word meter comes from the Greek word metron meaning to measure. It is hard to use a meter and not measure something.

Anyway the meters measure current and I believe the Crack puts out around 333 mw at 300 ohms with clipping at around 10v rms. Since current equals power divided by voltage the meter would show about .03 amp, safely within the range of the meter. Impedance does vary with frequency and you can probably use headphones down to about 100 ohms with this amp so I figured a .5 amp current range would be a good place to start.  I can adjust the meters down to a .1 amp range if need be.  YMMV but this is what I considered when looking around for VU meters.


----------



## CarlosUnchained

I'm new to DIY world so I'd like to start with a kit, the Crack caught my eye.
Since is an OTL amp It does not pair well with my LCD-X.

I'm looking for advice on what parts change/add/remove to make it more powerful on the 20 ohm region.

Also I'd like to add a second pair of RCA variable output to use it as preamp.

Is something like that possible having the Crack as a base?


----------



## Allanmarcus

CarlosUnchained said:


> I'm new to DIY world so I'd like to start with a kit, the Crack caught my eye.
> Since is an OTL amp It does not pair well with my LCD-X.
> 
> I'm looking for advice on what parts change/add/remove to make it more powerful on the 20 ohm region.
> ...


It will not pair well. There is some discussion on some mods you can try on the Bottlehead forum <http://bottlehead.com/smf/index.php?board=24.0>, but from my reading, it's just not recommended for low impedance headphones.


----------



## Paladin79 (May 31, 2017)

CarlosUnchained said:


> I'm new to DIY world so I'd like to start with a kit, the Crack caught my eye.
> Since is an OTL amp It does not pair well with my LCD-X.
> 
> I'm looking for advice on what parts change/add/remove to make it more powerful on the 20 ohm region.
> ...



Unless someone else gives a good answer on the RCA out as preamp, I was going to experiment with that in the next few weeks and I can get back to you. I have a lot of other things I am doing first but I definitely have room for another set of RCA jacks on the back plate of the amps I am building. (I went with front and back plates as well as a standard size top plate all in copper.)

If it works and you want to use the original plate, you should be able to drill two more holes for said preamp out.

As far as the headphone impedance, I personally looked at it as a reason to buy more headphones. I modified one pair of Colorado Headphone Company cans by adding 250 ohm drivers and by turning them from closed to open.


----------



## i luvmusic 2 (May 31, 2017)

IMO you have two options regarding preamp out.

1. TRS to RCA adapter.





2.The headphone jack is switch so you can attach a RCA jack to the other side of that jack.

I personally like the option 1.


----------



## Paladin79

i luvmusic 2 said:


> IMO you have two options regarding preamp out.
> 
> 1. TRS to RCA adapter.
> 
> ...



Personally, I would go with something more permanent like the second option. You would definitely have the volume controls in the circuit so the sound output would be variable. I will have to check and see how they did it on my Valhalla 2, I have only used such circuitry on existing amps and had not given it a lot of thought yet.


----------



## i luvmusic 2 (May 31, 2017)

Or you can connect the RCA from the POT's output or where the HP jack's connection  from the pot's output any of these connections will work.I like it on the other side of the jack so if a HP jack is inserted the connections to RCA will be off(HP jack is switch type).
I've never done the option 2 but i did with the option 1.


----------



## Paladin79 (May 31, 2017)

I will have to think about it some, at least trying out the cable should be similar to hooking up the circuit at the same point so I will see how well I like it with amplified speakers. I also have a NAD amp in circuit with standard speakers I could hook up pretty quickly. It would be nice to get some tube sound going through that amp.

This may be a great weekend to put on season five of House of Cards and do more work on the Crack amps.


----------



## Allanmarcus

wow, I just tried the Crack as a preamp. I'm impressed. Listening through my Koss ESP950, and A/B comparing between the Crack and a Mjolnir 2 as preamps (DAC is Bimby). I'm hard pressed to tell the difference. Now I have to pull out the Taurus Mk 2 and try the set up with that amp.

If it works well, I may tap out of the headphone jack and put in a set of RCA females on the crack for preamp out like @i luvmusic 2 suggests.

I also posted on a crack preamp thread to see if the crack experts have better ideas.


i luvmusic 2 said:


> Or you can connect the RCA from the POT's output or where the HP jack's connection  from the pot's output any of these connections will work.I like it on the other side of the jack so if a HP jack is inserted the connections to RCA will be off(HP jack is switch type).
> I've never done the option 2 but i did with the option 1.


i tried option 1 and it worked well; very well, with my ESP 950. I think it sounds as good as my Mjolnir 2 as a preamp. I also tried with my Taurus mk 2, and was impressed. I will do more listening this weekend, and if I like it, I will look into option 2. I confirmed with doc on the actual bottlehead crack forum (which I highly recommend), and he recommended coming off the jack rather than anywhere else for preamp out jacks.


----------



## Paladin79

The headphone jack is indeed the most logical place and as I said earlier, method 2 is the one I would prefer to use other than for test purposes.

I will take the output into powered Martin Logan speakers as well as through a NAD amp I refurbished that has dual volume controls (my preference).

Very good question Carlos and excellent answers Luv!


----------



## CarlosUnchained

Thanks @Paladin79 ,

I see that the preouts can be achieved somehow, but not the issue for low impedance cans. Since I'm not willing (for now) to buy another pair of headphones, I'll skip the Crack.

I found this interesting build that fits my needs much better. I'll add preouts and try to upgrade power out. Lower price but full responsibility on getting the right parts.

https://wtfamps.wordpress.com/papa-rusa-headphone-amplifier/

What do you think of it?

If I get too scared I might save enough money for S.E.X.


----------



## Allanmarcus

CarlosUnchained said:


> Thanks @Paladin79 ,
> 
> I see that the preouts can be achieved somehow, but not the issue for low impedance cans. Since I'm not willing (for now) to buy another pair of headphones, I'll skip the Crack.
> 
> ...




Very interesting. You also might consider a Garage 1217 amp. Many people lover their (easy to build) amps.


----------



## Paladin79 (Jun 1, 2017)

I may have time to look at it in more depth later today but are these folks basically telling you which parts to buy or selling a kit? It has been ages since I studied cathode follower amps but personally I prefer things that have been out there a long time such as the Crack, where there is a proven history and upgrades have been made. I have looked at other such kits where the sellers were solving hum issues long after kits were sold and completed and such things bother me. Bottlehead has a great support structure in place and the amps have been around a while. That is my opinion and probably not the answer you were seeking.

I also think what I saw skimming that site is that those amps would be for more seasoned builders. I would not have any issues but if you do not have a background in electronics, Bottlehead takes you step by step through soldering and safety and is an excellent first choice. You can look around on this site and see if anyone here talks of building that amp and the results they achieved.

If you can be patient, my son insists on being able to hook up some 32 ohm headphones to an amp I will build for him, I may well be building a SEX or Mainline soon if they can handle said impedance. (I have done little research on them thus far so perhaps Doc B can jump in here and enlighten me.)

Tom


----------



## DavidA

CarlosUnchained said:


> Thanks @Paladin79 ,
> 
> I see that the preouts can be achieved somehow, but not the issue for low impedance cans. Since I'm not willing (for now) to buy another pair of headphones, I'll skip the Crack.
> 
> ...



Agree with @Allanmarcus about the Garage 1217 amps but like you said in the Lyr2 thread the looks are not great IYO.

One thing that I love about all BH amps like the Crack and SEX is the great instructions and support structure of users and the manufacture as @Paladin79 noted.


----------



## CarlosUnchained

@Paladin79 , patience is one of my virtues.

This guy (Mr. @Sodacose) doesn't sell anything, he just explains his designs and which parts you should use to build your own and a few possible upgrades. Btw, he's answering a lot of noob questions and he's willing to help me get what I need to start.

As I said previously, I'd rather start with a kit, the problem is that I can't find many options out there, and even less that fits my needs and taste. I need power for low impedance, preouts (some load would be nice but not needed) and chasis is also a important part for me.
He recommended me to go with a small speaker amp as I use the LCD-X (4 W @ 8 Ohm for speakers and 1 W @ 32 Ohm for HP) as his project:  https://wtfamps.wordpress.com/la-luciernaga-part-2-the-amp/

I read that both S.E.X. and Mainline handle low impedance pretty good, but we are getting to another range of price.


----------



## Paladin79

Carlos, can you read a schematic diagram?  Have you had soldering experience? Do you understand that half an amp of current under the right circumstances can kill you?

 The gentleman at What certainly looks like he knows what he is doing; I glanced at the formulae and they look to be correct. As long as he is willing to help you that is certainly a good thing.
Since this is a Crack related thread I feel more comfortable talking about the Bottlehead products here as you can probably tell.


----------



## CarlosUnchained

Paladin79 said:


> Carlos, can you read a schematic diagram?  Have you had soldering experience? Do you understand that half an amp of current under the right circumstances can kill you?
> 
> The gentleman at What certainly looks like he knows what he is doing; I glanced at the formulae and they look to be correct. As long as he is willing to help you that is certainly a good thing.
> Since this is a Crack related thread I feel more comfortable talking about the Bottlehead products here as you can probably tell.



I do have experience for all those things. I graduated in physics so I've build some low voltaje devices including detectors and very rudimentary filters. https://i.imgur.com/LlUIHRj.jpg I played with tubes too, just different ones 
I know the circuit theory, how they behave, and I understand what every component does to the atomic level.
However, my building experience is not much (I just follow rules), but I'd said I'm pretty good at it having the right tools (which I don't own).

I've never dealt with high voltage circuits, I don't know how to design anything and how to achieve a certain goal, in this case, noiseless flat audio amplification. I just focused on the theory, not applications and topologies.

Having said this, you are right this is not the best thread for this topic. I'll go to the DIY forum for more help.

S.E.X. can be a nice point to start though


----------



## Paladin79 (Jun 1, 2017)

Carlos you asked some very intelligent questions that led to good discussion and I wish you well in your endeavors. My tube theory is not what it once was but if you get into an area where you do have questions PM me and I will always try to give you an answer, even if the answer is I do not know.

The Cracks I am building are more to impress local friends who are involved with physics, astrophysics, mathematics and such so much of my concern is about cosmetics and eye appeal and they enjoy sci-fi and steampunk.  I like good sounding equipment of course and the amp sounds great even without many upgrades.

I cannot think of a proper pun about S.E.X that might not bring about a moderator intervention so the less I say now the better, take care.


----------



## CarlosUnchained

Many thanks @Paladin79

I don't think it has to be with being physicist or else, It's just people out of the hobby that don't specially get excited by the specs of an amp but just enjoy hardware.
I share the excitement of seeing tubes and wood though. For me cosmetics are almost as important as specs in order to choose a product.
I don't mind paying extra when I get double the pleasure by listening AND looking at my hardware.

I hope you find the Crack appealing and proceed with the S.E.X. later on.

...sorry for that

See you around!


----------



## Paladin79

Just got two Tung Sol 5998's in the mail but I will have to listen later tonight. I did take the time to plug them in and make sure they came up properly, I will have to clean the pins on one, no filaments at first but it will be all right.


----------



## i luvmusic 2

I've used my crack as a buffer(connected to TAPE LOOP)i have a good result as will.


----------



## Paladin79

Cool, I am using mine as a preamp into a NAD amp to try out different tubes.


----------



## CarlosUnchained

i luvmusic 2 said:


> I've used my crack as a buffer(connected to TAPE LOOP)i have a good result as will.



What is TAPE LOOP?


----------



## Allanmarcus

CarlosUnchained said:


> What is TAPE LOOP?


On an integrated amp or receiver there is a line out called Tape Out and a line in called Tape in.  There will also be a button to monitor the tape in.  The idea is to be able to use magnetic tape to record whatever is playing, and to be able to monitor that recording.


----------



## hawkwindx

Hey Paladin, how are those Tung Sol 5998s sounding?

As far as the eye appeal and steam punk look you're going for, for my eyes the wood doesn't contrast enough with the copper. Maybe some day build another box out of metal with sharp rusty spikes and giant rusty nails and thick chains hanging off of it. Add some circuitry that causes snaps and sparks. What do you think?


----------



## Paladin79 (Jun 3, 2017)

The Tung Sols seem to have deepened the bass a bit, one gives me fits, I have cleaned it a couple times but I do not always get good contact.

You are echoing my thoughts on the contrast. As I mentioned in a recent post the brown cabinet came out a little dark for my liking and the patinated plates kind of blend with it so on my second cabinet I will use another finish and probably use shiny copper with this box. Everything unplugs so I can pull the plates easily. Perhaps being a gemini causes me to buy everything in twos so I still have options.

I do have some blade switches but I began scaring people as I sent them on top of the amp. I may use them to control the lights in the VU meters down the road.

Right now I am knee deep in trying to get my second amp going and my modifications are correct but something is amiss. The transformer was changed on this model compared to the first one I put together. My memory is not as good as it once was, time to get the instructions out lol. It's been a good month since I built one of these but I thought I could build one from memory. I was a little concerned about the wiring on the two single gang pots I am using but they are correct.

 I will get it figured out but it will be time consuming. I am also applying a coat of wax to the finished cabinet, it looks a little better in person. Steampunk is more brass gears and pressure gauges and there will be working gears involved in the build. I am also rereading Perdido Street Station by China Mieville  for inspiration, as well as a series by Ballantine and Morris.


----------



## Paladin79 (Jun 4, 2017)

Amp is now complete and working.  The VU meter lights are not as bright as they appear in the photo, I still have to tweek them a bit. With all of the work I have done on the copper plates I was not getting a real good ground yesterday but it took all of ten minutes to remedy that today. This sounds every bit as good as my stock Crack amp and perhaps a bit better with shielded cable.

Adding separate pots and VU meters did nothing to affect the sound IMHO. Running the amp off of preamp out on a Valhalla 2 amp so tubes throughout, I love the sound. Right now using a Tung Sol 5998 and GE 12AU7 cause it was handy. Front dual volume controls and no cables showing except for the headphone cable, jack is mounted on the right side of the cabinet. Now I am on to turning a second Crack into something similar,

Tom


----------



## hawkwindx

That is a great looking amp!


----------



## MattTCG

Looking for advice on the best way to remove rust from the power bell.


----------



## Paladin79

I would use steel wool myself. It is how I polished mine before painting it. But then definitely paint it.


MattTCG said:


> Looking for advice on the best way to remove rust from the power bell.


----------



## MattTCG

I'm guessing that it can't be painted after the build is complete.


----------



## Paladin79

hawkwindx said:


> That is a great looking amp![/QUOT
> 
> Thanks Hawk. I have been offered right at $750 each excluding parts to build a couple more of these but I am not sure I want to take it on just yet and I would have to pay someone to make the cabinet and figure in about 20 hours of build time for myself.


----------



## Paladin79 (Jun 5, 2017)

MattTCG said:


> I'm guessing that it can't be painted after the build is complete.



It would take a whole lot of masking but it could be done. One I built stock is starting to rust as well and I have only had it for a month and a half, it did sit in someones closet as a kit for over a year though.


----------



## hawkwindx

You could include pictures of your amp in the gallery section of the Bottlehead forum.


----------



## Paladin79

Yeah I may well do that, thanks for the advice. I have to figure out where to put the badge now, I might be able to center it on the front plate. Once I get the shiny copper plates in this wooden box the appearance should be nicer, I hope to use just a golden oak finish on the one I keep with these copper plates. This finish was supposed to be golden but looked more on the brown side.


----------



## DavidA

MattTCG said:


> I'm guessing that it can't be painted after the build is complete.



You can undo the bolts and remove the bell to paint, I did it with mine.


----------



## Allanmarcus

Just pull off the tubes and spray paint the whole top!


----------



## Paladin79 (Jun 5, 2017)

Sockets and all!  JK
One final touch, the badge.


----------



## Paladin79 (Jun 6, 2017)

ok I am now trying some NOS RCA 6AS7G"s and I am suitably impressed. I will have to start comparing other tubes to these soon lol.

I do have two Speedball upgrades to add to my two Crack amps but I am really starting to wonder how much of an improvement they might make. Using the preamp out on a Valhalla 2 and listening to some binaural plus music that I know well, I am so pleased with the sound that I feel any improvement might be very slight. All of my cabling is top notch as are my source files, tubes, etc.  I have probably reached a point of diminishing returns but I will try the speedball on one amp and compare them all the same.


----------



## hawkwindx (Jun 7, 2017)

I'm using this 6080WA and a Sylvania 6SN7W (using an adapter) without speedball and everything else is stock. Using it for a while to make sure it continues to work well before installing the speedball. This amp sounds great as it is. I'm also wondering how much better this can sound after the speedball is added.

Paladin, really nice that you have a couple amps that you are comparing and sharing with us here. Interested in your comparisons of stock 6080, your 6AS7G, and 5998.


----------



## Paladin79

This weekend I have a friend coming in who has exceptional hearing, I am anxious to get her thoughts on the two amps and which tubes she likes better. I will install a speed ball in one and do some testing side by side. I do own a few o'scopes and signal generators so some of my tests are more serious than others.
i do have a Chatham 6080WA I like and to me it is as good or better than the Tung Sol 5998 but the RCa 6AS7G's are pretty amazing IMHO.


----------



## i luvmusic 2

Paladin79 said:


> Amp is now complete and working.  The VU meter lights are not as bright as they appear in the photo, I still have to tweek them a bit. With all of the work I have done on the copper plates I was not getting a real good ground yesterday but it took all of ten minutes to remedy that today. This sounds every bit as good as my stock Crack amp and perhaps a bit better with shielded cable.
> 
> Adding separate pots and VU meters did nothing to affect the sound IMHO. Running the amp off of preamp out on a Valhalla 2 amp so tubes throughout, I love the sound. Right now using a Tung Sol 5998 and GE 12AU7 cause it was handy. Front dual volume controls and no cables showing except for the headphone cable, jack is mounted on the right side of the cabinet. Now I am on to turning a second Crack into something similar,
> 
> Tom



I really like the finished look of your amp beautiful,Congrats!


----------



## i luvmusic 2 (Jun 8, 2017)

Speaking of PREAMP these is what is running all my gears just got this done yesterday.

(DIY Preamp)


----------



## Paladin79

i luvmusic 2 said:


> I really like the finished look of your amp beautiful,Congrats!



Thanks and it is good to see you got your preamp done. I am very familiar with the VU  meters now if you ever need help. I ended up using 15k current limiting resistors and now they are perfectly matched for the Crack amp. I have a few wires to shorten and a power supply for the meters to incorporate inside the box and then i will start testing the speedball in the other amp to see what change it makes. There is a good chance i will be building more of these for folks who liked the layout. (not selling them on here of course, just family and friends mostly.)


----------



## i luvmusic 2

Paladin79 said:


> Thanks and it is good to see you got your preamp done. I am very familiar with the VU  meters now if you ever need help. I ended up using 15k current limiting resistors and now they are perfectly matched for the Crack amp. I have a few wires to shorten and a power supply for the meters to incorporate inside the box and then i will start testing the speedball in the other amp to see what change it makes. There is a good chance i will be building more of these for folks who liked the layout. (not selling them on here of course, just family and friends mostly.)



I will PM you when i'am ready for my next build,THANKS!


----------



## hawkwindx

What is that preamp called? Looks cool!


----------



## i luvmusic 2

hawkwindx said:


> What is that preamp called? Looks cool!



If you are refering to my DIY Preamp, Just call it ''I Have No Clue" Preamp.

Thanks!


----------



## Paladin79

This weekend I hope to add a speedball upgrade to my standard Crack amp and compare one Crack with and one without said upgrade. I also need to go back and try my favorite tubes in a stock Crack to be certain I am comparing apples to apples.

I also realized that my Valhalla 2 is a great way to get the signal to my Crack but i can reverse the process and use the Crack as a source into the Valhalla and get more use from my lower impedance headphones. I will have to check this out to see if I am as pleased with the results as the other way around.

I also need to start shopping for Dacs that will compliment the Crack amp, possibly tube type output. I have people wanting me to hand them a modified Crack and headphones but they will still need a DAC. Hopefully I can find something decent around $500 since most want to keep the three pieces around $2,000 or thereabouts.  Any suggestions are certainly welcome.

Tom


----------



## MattTCG

For a complementary DAC, I'd look no farther than Modi MB. The price/performance is as good as it gets and pairs very well with the Crack.


----------



## Paladin79

That DAC is certainly worth considering and i really like the Valhalla 2 I own. Price is great but it does max out at 24/192; apparently  the Bifrost Multibit is probably the next step up and costs considerably more but offers upgrade-ability. One of the gentlemen is an EE so I best give him a choice.

Thanks for the input Matt.


----------



## MattTCG

No problem. When comparing the Modi MB against the Bifrost MB, the difference was there but somewhat subtle. Then stepping up to the Gungnir MB was quite noticeable but then there's the price and that's it's best used balanced.


----------



## Paladin79 (Jun 11, 2017)

Yeah it is a pretty good price jump so the Modi is still in contention. I suppose anything I found with tubes is only using them in the pre-amp out stage but I definitely want the folks to have a quality DAC section no matter what.

Ok the big difference between my stock Crack and my modified Crack is the volume control (my modded one has dual Alps single gang pots). They sound pretty similar with the same tubes but I love the smoothness of the Alps when cranking the volume and being able to tweak each channel a bit if needed but other than that it is tough to discern much difference so far. I will see what happens with the speedball when I get back into town later today.

I installed the speedball in my standard Crack amp and it is a little too early to tell how much difference it will make but at least it is up and running.

 There were a few things I found to be a little sloppy in the speedball kit compared to the amp but it is going so I am thankful I have some things laying around my shop I could use. If any of you do the install and have issues and need a quick response contact me and I will try to help.

There is an obvious difference, I have only tried a half dozen songs so now I have to figure an easy way to switch back and forth between amps on the same music, at the same volume level with similar tubes on the same headphones. I am picking up a bit better separation of channels and and perhaps a more prevalent mid-range but those are just preliminary thoughts.


----------



## i luvmusic 2 (Jun 11, 2017)

This should do it a simple 3P ON-ON Switch from any OUTPUT to AMP 1 and AMP 2.Sorry! for my unconventional schematic Drawing.


----------



## Paladin79

Yeah I definitely understand the switch portion but what I will need to do is build a splitter cable going from both amps to the same headphones. Both signals will not arrive there at the same time what with the switch but I want to be able to hear one amp, then the other in the same headphones. Same music, same volume level, etc. I did not want to use my extra bulkhead mount female 1/4 trs  so I will grab one that is cable mount. I also have a slight delay with letting other listeners judge the sound differences but that will take place in a week or two so I have plenty of time. 

As far as the switch I have audio/video switches set up with female rca connectors so it will save me wiring something like that.

When done i will be able to switch between Crack amp with speedball and Crack amp without. While the tubes i will use will be as identical as possible i will swap them at some point and do the same testing all over again.

Tom


----------



## Allanmarcus

Since it can take 60-120 seconds for our brain to adjust to sound input, you are probably fine just splitting the output of your DAC into both amps, then simply listen to one amp for a couple of minutes, unplug the headphone from A and plug them into B, then listen for a couple of minutes to the same part of the song.


----------



## Paladin79 (Jun 12, 2017)

I understand about the adjustment period but I will also be looking at various signals using test equipment and prefer not to plug and unplug as I test. 15 minutes of cable building is not an issue for me and with other folks involved (giving me their opinions on which amp they prefer), a switch will make it less obvious which amp I am engaging at any given time.

I am now set up with switch box and Y cable so testing will begin soon on Crack with and without Speed ball upgrade.

Also early in my career I worked with a gentleman who designed speakers and we could switch from speaker to speaker to speaker as a comparison. I like the instantaneous approach personally so that is what I will use. It is also a very good way to tweak in the volume level as one goes back and forth between amps. The more things I can have equal, the better.

Tom


----------



## i luvmusic 2

Or get two identical Headphones one for each amp,There you go BOB is auntie!


----------



## Paladin79 (Jun 13, 2017)

hmmm and four ears! I do have plans to build another set like the ones I modified but not quite yet. Right now I am just doing a bit of comparison and then I need to build at least two more Crack amps that I do not mind giving up. If it turns out I like the amp better without the speedball, I will have a complete kit unused and will not order it with my future Crack purchases. I seem to recall some liked the amp better without it but I try to stay open minded.

I am going as far as building two identical sets of interconnect cables.

I set this up quickly and it is not pretty but right now I can quickly switch back and forth between both amps, lower standard version with speedball, modified cabinet version without. After I have tried this out for a bit I will post my findings.

There is obviously less background hum with no signal on the speedball version. Obviously this has been said before, I just read it described as a "black" background with speedball upgrade. I tend to form my own opinions before doing a lot of research so much of what I am saying is no doubt redundant.

 I used Mogami Neglex 2534 throughout the test set up with a short final stage of some Belden Brilliance series. Top of the line Neutrik 1/4 inch connectors.

This is also a quick and easy way to compare tubes. Early on yesterday I thought the speedball made the midrange a bit cleaner, it was cleaning up the low frequency noise that caused that effect. I have no doubt I will be able to see a difference on a scope, that will have to wait till this weekend but for right now there is certainly an audible difference.


----------



## Paladin79 (Jun 17, 2017)

I am going to attempt to use all shiny copper on my next crack build. It should look good with this quartered oak and I will probably use the patinated copper in a limed quarter oak box, just to make the patina jump out a bit more. 

Another way I can achieve the height I prefer is to use two of the bottlehead crack cases one on top of the other.  By using those I can build my own wooden case and use the size plates I prefer. I can achieve this with a jigsaw and dremel tool since I do not own a lot of big power tools.


----------



## Paladin79 (Jun 20, 2017)

ok I know this is a bit crazy but some time back I read about some headphones that mostly made their appearance about 12 or so years ago, Darth Beyers. I did not own a pair, till now...250 ohm and match up well with the Crack. Zebra stripe meets tiger
stripe. They look bizarre but the bass is incredible. Something I would call a ported closed design, or semi open.The cup allows the bass to reverb a bit, old school but interesting.


----------



## HOLLOWCOW (Jun 29, 2017)

Anyone here use UPS to protect the crack?
I have the crack+speedball upgrade and In my region we have frequent electric problems. I'm gonna use APC br550gi UPS to protect my PC and I wonder if it is safe to power the crack
with the ups battery, or plug it only to the surge protection.
this UPS is not using pure sine,
I heard it can cause problems with the PSU of the computer (active pfc). is this relevant to the crack also?
I have the latest crack version with the international transformer.

Also what happens if the crack is not protected with a ups?
does it damage the crack? and what about the tubes?
Thanks.


----------



## LikeABell

HOLLOWCOW said:


> Anyone here use UPS to protect the crack?
> I have the crack+speedball upgrade and In my region we have frequent electric problems. I'm gonna use APC br550gi UPS to protect my PC and I wonder if it is safe to power the crack
> with the ups battery, or plug it only to the surge protection.
> this UPS is not using pure sine,
> ...


Better ask this at the BH Forum.


----------



## Paladin79 (Jul 2, 2017)

My present crack build will involve carbon fiber plates with the same setup as my copper plates. One four inch plate on each end along with a ten by six inch top plate. All connections will be to the rear of the amp and there will be dual VU meters and dual single gang Alps pots in the front, headphone jack will be on the right side. The cabinet will be a limed oak so the basic look of the amp will be grey and black with silver showing instead of copper. Later today I hope to have made all necessary cuts and should have the cabinet and plates as they will finally appear. I have some detailed photos of the previous build on the Bottlehead forum gallery page for those who want to see how the cuts were made in all plates.


There is still a layer of protective plastic in place over the carbon fiber but all cuts are made to cabinet and top plate.


----------



## Paladin79

I have to find some proper feet for it, do a lot of sanding and applications of black lacquer but it is coming along. Plates are just set in place right now. I am still a long ways from a piano finish.


----------



## Timoteo80

Paladin79 said:


> I have to find some proper feet for it, do a lot of sanding and applications of black lacquer but it is coming along. Plates are just set in place right now. I am still a long ways from a piano finish.




Man you're crazy Tom!....& I like it hahaha


----------



## Timoteo80

I need to re polish the top plate & the aluminum on my Lenco L75 turntable but here is where my system is at as of now....


----------



## Timoteo80




----------



## Paladin79

My son wanted black and I had thought about carbon fiber for a while. Originally he wanted limed oak so we bought about six different finishes but he was not crazy about any of them. He mentioned a black piano finish and then Alanmarkus said the same thing so it is my goal. I am giving this one away so if it does not come out perfectly on looks it will still sound good.

Wow nicely done matching up to the turntable!!  Very pretty.

My problem is I absolutely hate the idea of reaching across the top of the amp to plug and unplug anything so all of my builds will be this design, transformer and two tubes in top plate, nothing else. I also prefer control over each channel as well as analog vu meters but I am stating the obvious. 

My next build will be a combination of my first two crack builds. It will most likely be limed quarter oak cabinet with copper plates buffed to a high shine. I have a few people wanting the amps so a lot of it has to do with how quickly I can purchase the next few kits. I enjoy building them and I can pretty much wire them in my sleep so it is just a matter of matching up to what some friends want. (I am also being offered a tidy sum for such builds so they have to be perfect.)

Tom


----------



## Timoteo80

Paladin79 said:


> My son wanted black and I had thought about carbon fiber for a while. Originally he wanted limed oak so we bought about six different finishes but he was not crazy about any of them. He mentioned a black piano finish and then Alanmarkus said the same thing so it is my goal. I am giving this one away so if it does not come out perfectly on looks it will still sound good.
> 
> Wow nicely done matching up to the turntable!!  Very pretty.
> 
> ...




Well we all dig your posts & seeing the projects come together. Thx for taking the time to share.

And thx for the compliment. I built that Lenco  & glad you noticed them matching. Eventually I am going to rebuild the Crack wood base. I used an epoxy glaze on the Lenco but tried a "triple thick" poly on the Crack. The poly is definitely not as transparent & has a "milky" tone to it which I don't like. It's noticeable side by side. So I'll build my own new base maybe even out of layered plywood/mdf like I did with the turntable & use the better epoxy so they really match nice. 

Good luck on your amp builds Tom!

Tim


----------



## Paladin79 (Jul 4, 2017)

I noticed on the Bottlehead site the other day that you can buy additional bases so that is also a way to go. I do not have a woodworking shop or I would cut some of my own bases. I was able to use a couple different Dremel tools and a jigsaw to cut my two existing bases. It looks like you are using speaker spikes for feet on the turntable. I may use those on the current crack build if I do not find something else more suitable.

This was an easy build for the most part, carbon fiber has 3M adhesive on the back and it was meant for the interior of a Corvette so it looks decent. I keep an original top plate around so I can make all the proper cuts in any material I use and that is how I line up the cuts on my back plate. I have a couple gold tube guards I want to incorporate on a build one day (front tube only) and they will lend themselves well to a shiny copper steampunk crack. Those require much more work, the black on black crack is ok but easy to give away, my original Crack is a keeper.

Tom


----------



## LikeABell

Hey everyone, a seller is willing to sell a pair of Tronix 6AS7G tubes. They're made in USA. Does anyone have any info on these tubes?


----------



## bookemJ

Hey guys got a question from a noob, I bought an Amperex 7308 tube and dropped it in my Bottlehead Crack w/ Speedball and it didn't light up/make any noise. Went to test it at a shop and it worked after cleaning the pins a bit. Brought it back home tried it again and it didn't work in my BHC again.  So I sent it back got a replacement thinking it was the tubes/socket not touching correctly and just got the replacement and this 1 doesn't work in my BHC either.  

Any tips you guys got I can try before I give up on this tube?


----------



## ProfFalkin

bookemJ said:


> Hey guys got a question from a noob, I bought an Amperex 7308 tube and dropped it in my Bottlehead Crack w/ Speedball and it didn't light up/make any noise. Went to test it at a shop and it worked after cleaning the pins a bit. Brought it back home tried it again and it didn't work in my BHC again.  So I sent it back got a replacement thinking it was the tubes/socket not touching correctly and just got the replacement and this 1 doesn't work in my BHC either.
> 
> Any tips you guys got I can try before I give up on this tube?



Is the 7308 compatible?

https://bottlehead.com/smf/index.php?topic=663.0

Doesn't look like it based on that list.


----------



## Timoteo80

H


bookemJ said:


> Hey guys got a question from a noob, I bought an Amperex 7308 tube and dropped it in my Bottlehead Crack w/ Speedball and it didn't light up/make any noise. Went to test it at a shop and it worked after cleaning the pins a bit. Brought it back home tried it again and it didn't work in my BHC again.  So I sent it back got a replacement thinking it was the tubes/socket not touching correctly and just got the replacement and this 1 doesn't work in my BHC either.
> 
> Any tips you guys got I can try before I give up on this tube?



Have you checked other tunes to make sure it is not a bad connection in your Crack?


----------



## Timoteo80

ProfFalkin said:


> Is the 7308 compatible?
> 
> https://bottlehead.com/smf/index.php?topic=663.0
> 
> Doesn't look like it based on that list.



Good point! Check up on that for sure too.


----------



## deserat

Timoteo80 said:


> Good point! Check up on that for sure too.



I ran the 7308 in my Lyr 2. It's not compatible with the Crack. The 7308 is a 6922 variant.


----------



## bookemJ

Wow the noob struck out. Appreciate you guys pointing out the obvious can't believe I wasted that much time trying an incompatible tube haha wow .


----------



## ProfFalkin

bookemJ said:


> Wow the noob struck out. Appreciate you guys pointing out the obvious can't believe I wasted that much time trying an incompatible tube haha wow .



As my father used to say...  "That's how we learn.   Now pull that tent spike out of your foot, and finish pitching the tent.   It's getting dark."


----------



## attmci (Jul 19, 2017)

deleted


----------



## deserat

bookemJ said:


> Wow the noob struck out. Appreciate you guys pointing out the obvious can't believe I wasted that much time trying an incompatible tube haha wow .



I've done the same thing, actually worse, I once had all the right tubes but was plugging them into the wrong sockets! All 8 pin sockets of the same size are compatible with all tubes that will fit in them right?   Welcome to the club!


----------



## Ahrimofnor

I am just starting my crack build now. I have put a clear coat on top of the transformer end bell to prevent rust. Is it okay for me to also paint the underside of the end bell as i am worried about rust there too. 

The manual says not to paint it as it may be a part of the ground loop but for the life of me i cant see any circuits or ground loops that incorporate the transformer end bell. Any thoughts on this?

I would ask on the bottlehead forum but it appears to be offline for me at least


----------



## ProfFalkin

I have yet to see Doc tell anyone not to do something just because.  If he says don't, seriously, don't.


----------



## LikeABell

The Bottlehead site is offline for me as well. Try to access the site though a proxy/VPN, it works then.


----------



## LikeABell

Has anyone been able to access the Bottlehead website? I haven't been able to since a few weeks now.
I get this error: "Access from your Country was disabled by the administrator."

Bummer.


----------



## DavidA

LikeABell said:


> Has anyone been able to access the Bottlehead website? I haven't been able to since a few weeks now.
> I get this error: "Access from your Country was disabled by the administrator."
> 
> Bummer.


tried just now and I can access it without any issue


----------



## deserat

LikeABell said:


> Has anyone been able to access the Bottlehead website? I haven't been able to since a few weeks now.
> I get this error: "Access from your Country was disabled by the administrator."
> 
> Bummer.



I can get to it fine.  Unfortunately their hosting provider is pretty bad. For instance if you try to log into the store and you use the wrong username and password it throws a security error and doesn't tell you that your username and password are bad. 
My bet is there were attacks ( DDoS, Brutforce Password ) coming from whatever country your IP is associated with and the provider just blocked the whole country or region. It happens.


----------



## Paladin79 (Aug 26, 2017)

Taking a working crack amp with speedball and removing everything from the top plate to change over to my three plate system is not the easy way to go because you have to cut a lot of wires and you have altered the original to add the speedball upgrade.
 I am also adding molex plugs so the top plate can be removed without   disturbing the front and back plates. The individual volume knobs in pearl and silver once adorned two Fender guitars.So far I have used about 12 coats of black lacquer on the cabinet but I cannot install the headphone jack in the cabinet side till all of that is done. The jack will have to be mounted then wired. Basically every wire had to be cut from the small tube socket to remove it so I have to keep the speedball upgrade out of the way while I rewire said socket. Luckily my son is not in a big hurry for this amp and this is not a build i would do for anyone but a family member. I should have known I was in trouble when I showed off my amp and my son asked if could have his own choice of materials. Oak was easier as was adding a patina to copper. When completed this should go nicely with a gloss black Music Hall turntable.


----------



## i luvmusic 2

Paladin79 said:


> Taking a working crack amp with speedball and removing everything from the top plate to change over to my three plate system is not the easy way to go because you have to cut a lot of wires and you have altered the original to add the speedball upgrade. I am also adding molex plugs so the top plate can be removed without   disturbing the front and back plates. The individual volume knobs in pearl and silver once adorned two Fender guitars.So far I have used about 12 coats of black lacquer on the cabinet but I cannot install the headphone jack in the cabinet side till all of that is done. The jack will have to be mounted then wired. Basically every wire had to be cut from the small tube socket to remove it so I have to keep the speedball upgrade out of the way while I rewire said socket. Luckily my son is not in a big hurry for this amp and this is not a build i would do for anyone but a family member. I should have known I was in trouble when I showed off my amp and my son asked if could have his own choice of materials. Oak was easier as was adding a patina to copper. When completed this should go nicely with a gloss black Music Hall turntable.



That is not a mess,Mine is.


----------



## Paladin79 (Sep 4, 2017)

Except for some polishing I am nearly finished with the carbon fiber crack amp that uses my three plate system. I also ran a preamp out to the back plate so my son can hook it easily to his speaker amp if he so chooses. I used a 3.5 mm for the preamp out because it can also double as a second headphone jack, since it is in parallel with the original jack, two sets of headphones can be run at the same time.

 I will build some silver audio cables to match and right now it just has the factory rubber feet till I find something better in silver. Vu meter lights are white whereas I used yellow on the steampunk crack amp. My next crack builds will most likely involve polished copper, more quartered oak, some top quality walnut, and or cherry.


----------



## attmci

Paladin79 said:


> Except for some polishing I am nearly finished with the carbon fiber crack amp that uses my three plate system. I also ran a preamp out to the back plate so my son can hook it easily to his speaker amp if he so chooses. I used a 3.5 mm for the preamp out because it can also double as a second headphone jack, since it is in parallel with the original jack, two sets of headphones can be run at the same time.
> 
> I will build some silver audio cables to match and right now it just has the factory rubber feet till I find something better in silver. Vu meter lights are white whereas I used yellow on the steampunk crack amp. My next crack builds will most likely involve polished copper, more quartered oak, some top quality walnut, and or cherry.


Nice. Now you have enough space to install those large Mundorf Caps.


----------



## ProfFalkin

attmci said:


> Nice. Now you have enough space to install those large Mundorf Caps.


Or enough room to hide a Magni 2 MB + Eitr under it.  Hehehe

Great work.


----------



## Paladin79 (Sep 6, 2017)

I definitely built my amps with room to spare. The black crack amp has a case double the size of the factory version, (two factory cabinets stacked, glued, and finished as one.) Knowing I would be using lacquer the base wood did not matter so much. There is a circuit board for the meters but it is no more than 2 inches by 3 inches and I have it mounted to the inside of one of the sides. I am going to go back and install a pre-amp out on my steampunk crack amp. I have been testing the carbon fiber black amp and really like the results and it was one of the easier changes to make on the Cracks IMHO.

I will install a DAC inside my Crack amp, I ship the other to my son in a week or so when all my testing is done. I wanted to burn it in a bit and make sure all of the internal plugs and jacks I installed do not work loose in shipment. I made both amps so the top plate unplugs from the permanently mounted front and back plates for ease of upgrades. My son will be able to make his own upgrades if he so desires. Right now the biggest change I made was dual Alps volume pots rather than ganged pots.

Tom


----------



## attmci

Paladin79 said:


> I definitely built my amps with room to spare. The black crack amp has a case double the size of the factory version, (two factory cabinets stacked, glued, and finished as one.) Knowing I would be using lacquer the base wood did not matter so much. There is a circuit board for the meters but it is no more than 2 inches by 3 inches and I have it mounted to the inside of one of the sides. I am going to go back and install a pre-amp out on my steampunk crack amp. I have been testing the carbon fiber black amp and really like the results and it was one of the easier changes to make on the Cracks IMHO.
> 
> I will install a DAC inside my Crack amp, I ship the other to my son in a week or so when all my testing is done. I wanted to burn it in a bit and make sure all of the internal plugs and jacks I installed do not work loose in shipment. I made both amps so the top plate unplugs from the permanently mounted front and back plates for ease of upgrades. My son will be able to make his own upgrades if he so desires. Right now the biggest change I made was dual Alps volume pots rather than ganged pots.
> 
> Tom



Add a pair of these and make your son a happy camper: http://www.ebay.com/itm/1-pair-2pcs...d=162343179900&_trksid=p2047675.c100005.m1851


----------



## Paladin79

Give me your recommendations (thus saving me the research) and I may well get two sets. Voltage and capacitance you prefer? I do not have a schematic in front of me, which two capacitors are you replacing?  Sorry to not know this but I spent most of my time on aesthetics.


----------



## attmci (Sep 6, 2017)

Paladin79 said:


> Give me your recommendations (thus saving me the research) and I may well get two sets. Voltage and capacitance you prefer? I do not have a schematic in front of me, which two capacitors are you replacing?  Sorry to not know this but I spent most of my time on aesthetics.


https://www.flickr.com/photos/28459414@N08/sets/72157677895339383/

The two output caps. You need 100uf/350V. There are a lot of discussions on cap upgrades.

JamieMcC is the man of cap rolls. LOL


----------



## Paladin79 (Sep 7, 2017)

Yeah I know there are a lot of discussions lol, my life is complicated enough so I will go with the 100uf/350v for now. I began teaching my son electronics, computers and chess when he was four so any other cap changes, he can make. He shocked me by fixing his own plasma tv when I shipped him a few parts so he can handle things like this. I will ship his amp with those though. I am going to buy them before someone else talks me into another value.

you have been most helpful attmci, thanks!

I do not have the speedball upgrade in my amp yet so I will probably install the caps in it then figure out a different way to mount those boards.

It is nice to know there are specialists in such things as cap rolling. I think my specialty from now on will be in finding someone with a cnc machine so I do not have to spend a day making all the cuts in the 1/8 inch copper I used for my three amp plates.

It is time to call in some favors so I get the Mundorf caps at a low price.


----------



## Renato Fury

Paladin79 said:


> Yeah I know there are a lot of discussions lol, my life is complicated enough so I will go with the 100uf/350v for now. I began teaching my son electronics, computers and chess when he was four so any other cap changes, he can make. He shocked me by fixing his own plasma tv when I shipped him a few parts so he can handle things like this. I will ship his amp with those though. I am going to buy them before someone else talks me into another value.
> 
> you have been most helpful attmci, thanks!
> 
> ...


Is it possible to buy a bottlehead amplifier already built ?


----------



## DavidA

Renato Fury said:


> Is it possible to buy a bottlehead amplifier already built ?


check the "for sale" thread: https://www.head-fi.org/categories/for-sale-trade-and-feedback-forums.109/


----------



## Renato Fury

DavidA said:


> check the "for sale" thread: https://www.head-fi.org/categories/for-sale-trade-and-feedback-forums.109/


I'm not talking about that site, I mean the manufacturer's website, bottlehead.


----------



## DavidA

Renato Fury said:


> I'm not talking about that site, I mean the manufacturer's website, bottlehead.


Unfortunately Bottlehead does not sell already built amps but I think it might have been mentioned in this thread that there are some who will build it for you, hope someone else can clarify this.


----------



## ProfFalkin

Renato Fury said:


> Is it possible to buy a bottlehead amplifier already built ?


Yes.  Well, kind of.

https://bottlehead.com/smf/index.php?topic=4783.0


----------



## Paladin79 (Sep 9, 2017)

Occasionally you will find them on Ebay as well  and a couple folks on there seem to do quality builds. I am committed to building a couple more but my builds require some extensive  modifications and they are not as cost effective as the gentleman listed on the Bottlehead site. The info given with the kits allows most anyone to build a kit but you would have to invest in some basic equipment so that part is up to you. I believe Alanmarkus pointed out that if you sell a completed kit on Head-Fi you are not allowed to profit from it so some of the best buys would come from here. If you do try to buy one here and there is an internal view of the wiring many of the folks here could probably give you an opinion on whether they believed it was a quality build.  I have no doubt you would be assured of a quality build if you went with the builder recommended by Bottlehead, caveat emptor.


 I totally enjoyed my first build but it is not for everyone and I easily have $250 in additional parts, the labor I would rather not talk about. I also bought many pieces for this build that I did not use, I like choices, and i will use them on future builds.


----------



## Renato Fury

Does anyone know why the heck this company does not sell their already built products ? The Garage company offers this kind of service but unfortunately the Bottlehead does not, unfortunate, just when I'm interested in an amp I know it's good I discover that it can only be sold to customers like myself who do not understand anything about building amplifiers can build it.


----------



## attmci

Paladin79 said:


> Occasionally you will find them on Ebay as well  and a couple folks on there seem to do quality builds. I am committed to building a couple more but my builds require some extensive  modifications and they are not as cost effective as the gentleman listed on the Bottlehead site. The info given with the kits allows most anyone to build a kit but you would have to invest in some basic equipment so that part is up to you. I believe Alanmarkus pointed out that if you sell a completed kit on Head-Fi you are not allowed to profit from it so some of the best buys would come from here. If you do try to buy one here and there is an internal view of the wiring many of the folks here could probably give you an opinion on whether they believed it was a quality build.  I have no doubt you would be assured of a quality build if you went with the builder recommended by Bottlehead, caveat emptor.
> 
> _*I totally enjoyed my first build but it is not for everyone and I easily have $250 in additional parts, the labor I would rather not talk about. I also bought many pieces for this build that I did not use, I like choices, and i will use them on future builds.*_



That's the best part. DIY!


----------



## Renato Fury

attmci said:


> That's the best part. DIY!


The best part is to pair the amp with the headphone and enjoy the sound, I just want to plug and play.


----------



## Paladin79 (Sep 9, 2017)

The owner of the company is on here occasionally, he should be the one to explain why he sells kits and not finished products. There are plenty of companies who sell finished OTL's but DIY kits allow the customer to save manufacturing costs and adapt the amp to their liking. Open up a prebuilt amp and start playing with it and you just voided the warranty. Want plug and play? Buy a Crack amp someone built.

They are also a good way to learn soldering techniques and component recognition.

There are plenty of things that make the Crack amp enjoyable, you have so much versatility in shaping the sound to match your tastes. It is not too hard to match headphones to the amp since you are starting out with high impedance headphones only. Try to think of another amp where folks try so many different sets of capacitors, tubes, control pots, and  chokes to shape the sound. The fact that you build it lends itself to your going back inside and understanding later changes you might make. I own a Valhalla 2 and I can swap tubes, that is about it. DIY amps are more geared to those who like to tinker with them, if that is not for you, so be it.


----------



## larcenasb (Sep 9, 2017)

Paladin79 said:


> DIY amps are more geared to those who like to tinker with them, if that is not for you, so be it.



To reinforce what Paladin79 is saying...yeah, it's cool to get a finished amp and call it a day--maybe I'll one day own a Leben CS-300XS (they're just beautiful!). But as you can see in my pictures below, I've learned a whole lot over the years by going DIY, from internal tidiness to being able to pinpoint my musical preferences upgrade-by-upgrade. And I'm so, so, so happy for that--especially since the Crack is, relative to other great heights of hi-fi, quite affordable. Okay, maybe I've gone a little overboard with the tinkering  but the little improvements and tailorings to my preferences got me to both musical bliss and to the empowerment of understanding electrical trouble-shooting. Whatever your route, being able to enjoy good music and unwind on a Saturday like this...ah, that's what it's all about.

*currently listening to Radiohead's _The Bends_*


----------



## Paladin79

Nice job with the build, once I finish building four Cracks I will go back and start modifying the electronics in my own. I have not even installed the speedball upgrade in mine yet since I have been busy with cabinet designs. I am working on getting a large amount of Mundorf caps at a low price and I may check out other brands as well.


----------



## Renato Fury

That is, I can never have a Bottlehead amplifier, but is there an amplifier in the range of 500 to 600 dollars that reproduces the same quality of Crack or who knows a superior quality ? One that has obviously been built.


----------



## larcenasb (Sep 9, 2017)

Paladin79 said:


> Nice job with the build, once I finish building four Cracks I will go back and start modifying the electronics in my own. I have not even installed the speedball upgrade in mine yet since I have been busy with cabinet designs. I am working on getting a large amount of Mundorf caps at a low price and I may check out other brands as well.


Thanks! I'm totally beguiled by the sound of mine, but I really want to try a 0.68uF Audyn True Copper Cap as my PS bypass--I know it's not the most efficient use of money but that'd be the cherry on the top. Audyn's explanation of it just had me dying and won me over:

"_No contamination by strange mixture of various metals and fairy-like oils._"

Each time I upgraded up to this point I kept it under $20 ($20 one month, $10 another, $20 a few months later)...so, this as a final upgrade at $50 isn't too outrageous. Your builds are just beautiful BTW. Cheers!


----------



## Paladin79

I am sure there are discussion threads on here about many tube type and OTL amps, I would search for those. If he still has it for sale, Allanmarcus talked about selling his Bottlehead Crack and he is a builder i would trust. He takes great care in all of his work and takes the time to learn. IMHO


----------



## ProfFalkin

Renato Fury said:


> That is, I can never have a Bottlehead amplifier, but is there an amplifier in the range of 500 to 600 dollars that reproduces the same quality of Crack or who knows a superior quality ? One that has obviously been built.


A used Elise, maybe.  I didn't like mine tbh.

Why can you never have a Crack?  I don't get that.


----------



## Renato Fury

ProfFalkin said:


> A used Elise, maybe.  I didn't like mine tbh.
> 
> Why can you never have a Crack?  I don't get that.


Because unfortunately I live in a junk country called Brazil, if I lived in the United States I could even hire someone to build for me, but living here in Brazil who will build for me ? So it's out of the question to have any Bottlehead product, worst of all is that I enjoyed Crack, they say it's the best in this Sennheiser HD 650 price range.


----------



## larcenasb (Sep 9, 2017)

Renato Fury said:


> Because unfortunately I live in a junk country called Brazil, if I lived in the United States I could even hire someone to build for me, but living here in Brazil who will build for me ? So it's out of the question to have any Bottlehead product, worst of all is that I enjoyed Crack, they say it's the best in this Sennheiser HD 650 price range.



Why not take the advice of Paladin79 and search for those on head-fi that would build it then send it to you? Or check out the for sale section on head-fi, or check ebay? If you really want it, you can find a way.

And hey, this is my 100th post!


----------



## Paladin79

Renato Fury said:


> The best part is to pair the amp with the headphone and enjoy the sound, I just want to plug and play.





larcenasb said:


> Thanks! I'm totally beguiled by the sound of mine, but I really want to try a 0.68uF Audyn True Copper Cap as my PS bypass--I know it's not the most efficient use of money but that'd be the cherry on the top. Audyn's explanation of it just had me dying and won me over:
> 
> "No contamination by strange mixture of various metals and fairy like oils."
> 
> ...


----------



## Paladin79

Renato Fury said:


> Because unfortunately I live in a junk country called Brazil, if I lived in the United States I could even hire someone to build for me, but living here in Brazil who will build for me ? So it's out of the question to have any Bottlehead product, worst of all is that I enjoyed Crack, they say it's the best in this Sennheiser HD 650 price range.




Whether it is a kit or a completed amp, most likely it would be shipped from the US. Go to the used equipment portion of the site and mention you are looking for someone to ship a completed Crack amp to Brazil.


----------



## Renato Fury

The problem is not to send here, the problem is to send to the already built, I do not know anyone who lives in the United States who can arrange this for me.


----------



## Paladin79

Since it is against the rules to make a profit on such things here, go on the Bottlehead Crack website, ask around and maybe someone will offer to build and ship you one completed for six crisp $100 bills.


----------



## attmci (Sep 9, 2017)

Renato Fury said:


> The best part is to pair the amp with the headphone and enjoy the sound, I just want to plug and play.


Then go ahead by an amp whic


Renato Fury said:


> The best part is to pair the amp with the headphone and enjoy the sound, I just want to plug and play.



deleted.


----------



## larcenasb

There's only one thing about my amp that's nagging me to make a change: Anyone else with an Alps 100AX2 pot notice the turning gets rougher as the Bottlehead amp heats up? At first, when cold, there's a luxuriously buttery resistance as you turn the pot, but once the amp is warm it becomes cheap-feeling.

Anyone with a TKD, or any other nice pot, experience this?


----------



## Paladin79

Where did you buy the Alps pot? There are some Chinese imports I stay clear of.

I have not experienced it with dual Alps but then my pots are mounted lower and do not get the full effect of the heat build up.


----------



## larcenasb

I got mine from a good dealer, partsconnexion.com. Curious if mine is just a bad pot, or if others are having this experience as well. Anyone?


----------



## ProfFalkin

larcenasb said:


> I got mine from a good dealer, partsconnexion.com. Curious if mine is just a bad pot, or if others are having this experience as well. Anyone?


My Alps pot has no such issue.   Check for cold solder joints in the pot perhaps?


----------



## larcenasb (Sep 9, 2017)

Thanks for the response! But how can a cold solder joint affect this? It seems like the heat loosens the grease or whatever is there for the turning tension. Since your Alps Blue doesn't have the issue, I'm very curious what's the deal with mine.

It may be worth it to buy another Alps Blue and test to see if the problem persists for me.


----------



## ProfFalkin

larcenasb said:


> Thanks for the response! But how can a cold solder joint affect this? It seems like the heat loosens the grease or whatever is there for the turning tension. Since your Alps Blue doesn't have the issue, I'm very curious what's the deal with mine.
> 
> It may be worth it to buy another Alps Blue and test to see if the problem persists for me.


Uhhh, pretty sure I misread your post.  Sry. But no, mine is fine.


----------



## larcenasb

No worries, but just to be clear: you have an Alps Blue Velvet (100AX2) in your Bottlehead Crack and even after, say, an hour of listening, you can turn the pot and it still feels smooth and weighty just like when the amp is cold? Thanks for your time!


----------



## Renato Fury

Could you recommend a tube amplifier with a tube sound that can be used with the Sennheiser HD 598 ? Nothing too expensive but needs to be something that beautifies the sound like a tube amp can do.


----------



## Paladin79 (Sep 9, 2017)

Larsenasb I have two dual gang 100 k  Alps pots that a vender gave me. I can send you one no charge to swap out your pot. If it helps it is yours. Private message me an address and I will have my people ship you one Monday. I only use Alps single gang in my builds.

Tom


----------



## larcenasb (Sep 9, 2017)

Renato Fury said:


> Could you recommend a tube amplifier with a tube sound that can be used with the Sennheiser HD 598 ? Nothing too expensive but needs to be something that beautifies the sound like a tube amp can do.



It's good you specified the cans you use...because the Bottlehead Crack's OTL design actually isn't ideal for low-impedance cans (yours are only 50 ohms). For those, a Bravo Audio Ocean ($89.99) would be a good match--I used the Sennheiser HD 555 with it and it sounded warm and much more powerful than without it. For the beautification you desire, you can start tube rolling: get some romantic-sounding 12AU7s (Brimar 13D5, Mullard CV4003, and RCA black plates) and see which is most beautiful to you.

Other options would be the Little Dot I+ ($100) and the Schiit Vali 2 ($169). These and the Bravo are all hybrid tube/solid-state designs that will be a more ideal match for your low-impedance cans than the (output transformerless) Bottlehead Crack.

If you want to go more expensive: you could get Schiit's higher-quality hybrid, the Schiit Lyr 2 ($449), or a transformer-coupled design--but IMO they'd be overkill unless you look to get higher quality low-impedance cans in the future. A well regarded transformer-coupled amp would be the Woo Audio 6 ($699). Good luck!


----------



## larcenasb

Paladin79 said:


> Larsenasb I have two dual gang 100 k  Alps pots that a vender gave me. I can send you one no charge to swap out your pot. If it helps it is yours. Private message me an address and I will have my people ship you one Monday. I only use Alps single gang in my builds.
> 
> Tom


Wow, the kindness. Thanks so much.


----------



## Paladin79

If you happen to build your own headphone cables or interconnects I will see what else I can include in the package.

I like the Schiit Valhalla 2 For around $350. Works well with 50 ohm Alpha Primes. It is OTL as I recall but does high or low impedance cans.

One day I will get a Micro Zotyl amp, but I will hear it first at the factory.


----------



## larcenasb

Paladin79 said:


> If you happen to build your own headphone cables or interconnects I will see what else I can include...



No, no, no! You're too kind! Just the pot is all I need. I do build cables but I don't need any atm. Thanks so much again!


----------



## Renato Fury

larcenasb said:


> Wow, the kindness. Thanks so much.


I intended to buy a Indeed G3 that has the same design as the Bravo Audio V2 only that improved and the Schiit Fulla 2 as Dac, but given all that I read it seems that a tube amplifier is not recommended for the HD 598 because I want to spend money to have no difference, I want something like night and day, so I ask you, are you sure that such a tube amplifier will make the sound hot ? Increasing the bass and midrange, controlling the treble and hiding to the maximum the imperfections that only a neutral headphone can reveal, this amplified you said can even provide me all that I desire ?


----------



## larcenasb

Lol, not _all_ you desire! That's a lofty expectation! But tubes definitely alter the sound, "no difference" is something you shouldn't fear. Apart from the character of the tubes, the amp also boosts bass, dynamics, and loudness. A night and day difference would be getting better headphones, but a great amp powering them will only get you closer to audio nirvana.


----------



## Renato Fury

Have you seen the "Amp and Sound" amplifiers ? They look pretty much like Bottlehead's, but they're prettier, but I hope their amplifiers are built, too bad they're so expensive.


----------



## DavidA

Renato Fury said:


> Could you recommend a tube amplifier with a tube sound that can be used with the Sennheiser HD 598 ? Nothing too expensive but needs to be something that beautifies the sound like a tube amp can do.


I would suggest looking at a Garage 1217 Solstice or the solid state Polaris since rolling tubes can get expensive quickly.  These amps have adjustable output impedance so you can better match them to almost any headphone.


----------



## ProfFalkin (Sep 9, 2017)

Renato Fury said:


> Have you seen the "Amp and Sound" amplifiers ? They look pretty much like Bottlehead's, but they're prettier, but I hope their amplifiers are built, too bad they're so expensive.


I have, and I'll be hunting down one of those amps at RMAF to demo it.  Not sure if I want a Mogwai or Encore.

Edit:. Or a BH Mainline.


----------



## Renato Fury

DavidA said:


> I would suggest looking at a Garage 1217 Solstice or the solid state Polaris since rolling tubes can get expensive quickly.  These amps have adjustable output impedance so you can better match them to almost any headphone.


I had already seen some amplifiers, including I had been interested in Project Ember but for being a hybrid I do not know if it would have the same quality as a Bottlehead for example, have you ever tested any to know if the quality is as good ?


----------



## DavidA

I have both the Ember and BH Crack and used to have a HD598 a few years back. The HD598 sounded best on the Ember of all the amps I had at the time that I owned them and didn't sound as good with the BH Crack, Lyr2 and WA7d (sold) to me mostly due the sound of the HD598 being a bit thin and a little harsh in the highs.  The BH Crack is really designed for high impedance headphones like the HD600/650/700/800 and not for low/medium impedance headphones like the HD598.  Another thing to consider is that the tubes used in the Crack can have a significant effect on how it will pair with any particular headphone.

If you want the smooth sound of a tube amp I would start with changing from the HD598 to either the HD650, NightHawk or SRH-1840 since these headphones have that smoother sound versus the thin and slightly bright sound of the HD598.  The headphone has the biggest influence on the sound so I would start with a headphone that sounds as close to what you want and then look at amps, DACs and cables (choke) to tune the sound.


----------



## Renato Fury

DavidA said:


> I have both the Ember and BH Crack and used to have a HD598 a few years back. The HD598 sounded best on the Ember of all the amps I had at the time that I owned them and didn't sound as good with the BH Crack, Lyr2 and WA7d (sold) to me mostly due the sound of the HD598 being a bit thin and a little harsh in the highs.  The BH Crack is really designed for high impedance headphones like the HD600/650/700/800 and not for low/medium impedance headphones like the HD598.  Another thing to consider is that the tubes used in the Crack can have a significant effect on how it will pair with any particular headphone.
> 
> If you want the smooth sound of a tube amp I would start with changing from the HD598 to either the HD650, NightHawk or SRH-1840 since these headphones have that smoother sound versus the thin and slightly bright sound of the HD598.  The headphone has the biggest influence on the sound so I would start with a headphone that sounds as close to what you want and then look at amps, DACs and cables (choke) to tune the sound.


Yes of course, the HD 598 would actually be my first headphone at hi-fi level and I intend to pair it with the Schiit Fulla 2 just because it's an amplifier with enough power to drive it, the BH Crack I intended to use with the HD 650 in the future but my plans have been frustrated thanks to this antics of the manufacturers do not sell it already built, so what I have left is Project Ember for the price, but for being a hybrid I do not know if I'm going to feel that sound that only tubes can provide, but worth just buying it? I do not want the neutrality of Valhalla 2 for example, I want the heat of BH Crack or the closest to it.


----------



## Ahrimofnor

Renato Fury said:


> Yes of course, the HD 598 would actually be my first headphone at hi-fi level and I intend to pair it with the Schiit Fulla 2 just because it's an amplifier with enough power to drive it, the BH Crack I intended to use with the HD 650 in the future but my plans have been frustrated thanks to this antics of the manufacturers do not sell it already built, so what I have left is Project Ember for the price, but for being a hybrid I do not know if I'm going to feel that sound that only tubes can provide, but worth just buying it? I do not want the neutrality of Valhalla 2 for example, I want the heat of BH Crack or the closest to it.



As someone who recently built the crack + speedball as my first DIY / soldering experience ever I can say it really is not that bad. The directions are phenomenal and as long as you take care when building it, you really cant screw it up too easily. That being said, there are some that are occasionally offered on reddit's AVexchange or here on the classifieds. Honestly, I would suggest getting the kit as I thoroughly enjoyed the DIY process of building everything especially as the finished product looks and sounds so damn good. I can not recommend building the kit enough. For reference, I spent about an hour or two a night and maybe three or four hours a day on weekends for two weeks staining / painting the base and soldering everything together in order to complete the crack + speedball.


----------



## DavidA

Renato Fury said:


> Yes of course, the HD 598 would actually be my first headphone at hi-fi level and I intend to pair it with the Schiit Fulla 2 just because it's an amplifier with enough power to drive it, the BH Crack I intended to use with the HD 650 in the future but my plans have been frustrated thanks to this antics of the manufacturers do not sell it already built, so what I have left is Project Ember for the price, but for being a hybrid I do not know if I'm going to feel that sound that only tubes can provide, but worth just buying it? I do not want the neutrality of Valhalla 2 for example, I want the heat of BH Crack or the closest to it.


Aside from the BH Crack the 2 other OTL amps that can give you a tube sound and with a change of tubes become closer to neutral are the Elise and WA2, granted these are not the cheapest amps but they respond to changes in tubes so much more than other tube amps that I've tried.  I wouldn't worry about the Ember being a hybrid, to me having the adjustable output impedance is a feature that has just as much of an influence in the sound than changing tubes.  I agree that the Valhalla2 is too neutral and it didn't respond to changes in tubes much and less than the Ember in my experience so far.


----------



## LikeABell

Renato Fury said:


> Have you seen the "Amp and Sound" amplifiers ? *They look pretty much like Bottlehead's, but they're prettier, but I hope their amplifiers are built, too bad they're so expensive.*


And we have thus arrived at the solution for your original question.


----------



## Renato Fury

LikeABell said:


> And we have thus arrived at the solution for your original question.


Unfortunately no, one has a more affordable price but I do not have the ability to build it, the other comes built but the cheaper one is a lot more expensive than crack, regardless of my continuing dilemma.


----------



## Paladin79

There are currently two Bottlehead cracks on ebay right now, completed and working. Contact the sellers and see if either is willing to ship to Brazil, bid on one is only $197.50 at this time but that could change drastically in the next few hours. lf you have an use paypal, they will darn near guarantee you get the product or they will freeze the seller till it is resolved. (based on my past experiences.)  Either that or buy a pre-built one from someone on here. Saying Bottlehead does not meet your needs by not offering a completed amp makes little sense to me. They do quite well with kits and the vast majority of people love building the kits. 
 To pay folks to assemble them and sit on the parts while completed amps sit on their shelves changes their business model drastically. Not sitting on a lot of inventory can keep their price down and allow them to offer their product at a reasonable price. I believe the owner said the last sale they had on Cracks produced the largest amount sold in their history. Their business model is working and they are able to be in business with a relatively small workforce. 

Yesterday I came really close to offering to build you one and ship it to you but I am already obligated and you would have a bit of a wait. If you get creative and do not mind paying up front I doubt it would be that hard for you to find someone to ship you a completed amp.


----------



## DavidA

Renato Fury said:


> Unfortunately no, one has a more affordable price but I do not have the ability to build it, the other comes built but the cheaper one is a lot more expensive than crack, regardless of my continuing dilemma.


If you are so concerned with expenses then I don't think a tube amp is something you want to get involved with since the cost of tubes can exceed the cost of the amp it self and many who build a Crack update many parts of the build like caps, volume pots, and the speed ball option.  I've spent more on tubes than the price of the BH Crack and this does not include most of the driver tubes that I was using in the Ember.  Its a reality of owning a tube amp that you need to include in your budget for tubes and due to the demand for NOS tubes the prices are only going higher.


----------



## Paladin79

Here is a quick and easy way to make a preamp out or extra headphone circuit for a Crack amp. 3.5 mm female, shielded Belden wire. It is just a matter of wiring it in parallel to the quarter inch jack you are using in the Crack amp. I have run two headphones or one headphone and preamp out into a power amp without affecting or lowering the sound quality in the least. In my case I can just drill a hole in the back plate of my amps and mount it next to the RCA inputs. With the standard top plate on a Crack amp, you can drill a hole there and you suddenly have dual headphone jacks or a preamp out in addition to the standard headphone out.


----------



## Renato Fury

DavidA said:


> If you are so concerned with expenses then I don't think a tube amp is something you want to get involved with since the cost of tubes can exceed the cost of the amp it self and many who build a Crack update many parts of the build like caps, volume pots, and the speed ball option.  I've spent more on tubes than the price of the BH Crack and this does not include most of the driver tubes that I was using in the Ember.  Its a reality of owning a tube amp that you need to include in your budget for tubes and due to the demand for NOS tubes the prices are only going higher.


You're right, I'll have to buy a solid-state amplifier myself, but I'm in no doubt between the Schiit Jotinheim or the Audio GB NFB 11.28.


----------



## Renato Fury

Okay so, I'm going to buy Sennheiser HD 6XX, Project Ember and a Dac, but which Dac would be the best choice to pair with Project Ember ?


----------



## Doc B.

Renato Fury said:


> my plans have been frustrated thanks to this antics of the manufacturers do not sell it already built


Antics - that's the first time in my recollection that someone has used that descriptor. Somehow we have been getting away with these antics for 22 years. Looking at it that way, I feel pretty lucky.


----------



## ProfFalkin

Doc B. said:


> Antics - that's the first time in my recollection that someone has used that descriptor. Somehow we have been getting away with these antics for 22 years. Looking at it that way, I feel pretty lucky.


It takes a very self-entitled point of view to think those are antics. 

On another note Doc... I've been trying to hit different parts of your forum all day, and have been getting hosting 504 errors.   Thought you should be aware of that.


----------



## Paladin79

I must have missed the antics and high jinx classes in my business training.


----------



## Doc B.

Yes, sorry about the site. We have been getting slammed with attacks the past few weeks. That combined with a big uptick in traffic since we released our new speaker kit has the site bogging down for a short time here and there. My IT guy is fine tuning every day to try to keep a balance between fending off the bot attacks and letting legit traffic thru. Speaking of which, we have had to beef up our firewall and block some countries from which most of the attacks were originating. If you get a 504 (timeout) or 502 (bad gateway) that's not us blocking, it's just heavy traffic from bot requests. In that case just try again in a few minutes. If you get a notice from our firewall that your country is blocked, PM me and I can help you with accessing the site.


----------



## Renato Fury

Doc B. said:


> Antics - that's the first time in my recollection that someone has used that descriptor. Somehow we have been getting away with these antics for 22 years. Looking at it that way, I feel pretty lucky.


And that I use google translator, it ends up saying words that I did not write, but I'm happy that your business is prosperous and profitable, and that it continues for another 22 years, but why the hell do not you offer the possibility to sell your already built amplifiers since people like me and many others can not build one ?


----------



## Doc B.

I am sorry that you cannot build a kit. There are a quite a few manufacturers who I am sure would be happy to offer a good sounding assembled product to you. We decided many years ago to specialize in offering kit products to those who wish to enjoy the building process and the knowledge gained by doing so. That's why the hell we do not offer the possibility to purchase already built amplifiers. We do recommend a couple of independent technicians who are very experienced at assembling our kits for those individuals who have no interest in building their own. I would be willing to put you in contact with them.


----------



## Renato Fury

Thank you sir tube head, but since I do not live in the United States I could not hire the services of a builder, who knows someday I'll be able to buy on Ebay.


----------



## Paladin79 (Sep 13, 2017)

PayPal offers the ability to make payments anywhere in the world.

Has anyone got any suggestions for some silver feet to go on the bottom of a Crack amp? I have seen small speaker spikes and I prefer something modern looking as opposed to ornate feet that mount on the outside of the box.  For this amp.
  I am also including a photo of the inside of this amp, I know it is a mess. The little yellow tubes at the bottom of the frame contain current limiting resistors for the VU meters. I do not like leaving resistors next to wires so they are housed in metal sleeves with a pvc insulator over the outside. The diameter is about double that of the resistors and the ends are open to allow for heat dissipation. The top plate will come out completely since I used Molex connectors for small wire, and spade connectors and such for larger wire gauges.


----------



## Renato Fury

You guys, stop flaunting your Bottle Head Cracks for those who can not build one.


----------



## ProfFalkin

Renato Fury said:


> You guys, stop flaunting your Bottle Head Cracks for those who can not build one.


=/


----------



## Paladin79

Heck I am just happy Doc B will sell me a kit when he sees the sloppy wiring I have going on under the last one I built.  In all seriousness though, through the years I have assembled Heathkits, Dynaco Dynakits, etc. and Bottlehead offers a fun product with excellent instructions. I take pride in offering some of my own interpretations and in no way is there any intent to make anyone feel bad about their kit builds or lack thereof. It is an excellent sounding amp that is still quite popular and I look forward to future builds.


----------



## Renato Fury (Sep 13, 2017)

Paladin79 said:


> Heck I am just happy Doc B will sell me a kit when he sees the sloppy wiring I have going on under the last one I built.  In all seriousness though, through the years I have assembled Heathkits, Dynaco Dynakits, etc. and Bottlehead offers a fun product with excellent instructions. I take pride in offering some of my own interpretations and in no way is there any intent to make anyone feel bad about their kit builds or lack thereof. It is an excellent sounding amp that is still quite popular and I look forward to future builds.


Relax, my friend, I'm kidding.


----------



## Paladin79 (Sep 13, 2017)

Good to hear and I am generally relaxed. If you get serious about wanting to buy one of the Crack amps there are plenty of ways to do it and you have received some good advice here.  Heck back in the day I shipped some equipment to countries where certain cigars that Fidel Castro liked could be purchased, Cohiba Esplendidos, worth their weight in gold in some countries lol. If you want something bad enough there are always ways to work through problems.

In the meantime if anyone has any suggestions for silver feet for the black amp I built before I ship it to my son, lay it on me. A lot of things I found were too large for my application.


----------



## attmci

ProfFalkin said:


> =/


Por que o idiota não pode construir um amplificador ainda aqui?

Estou só brincando. Usei o google tradutor e diz algo que não pretendia dizer.


----------



## larcenasb (Sep 13, 2017)

Paladin79 said:


> Larsenasb I have two dual gang 100 k  Alps pots that a vender gave me. I can send you one no charge to swap out your pot. If it helps it is yours. Private message me an address and I will have my people ship you one Monday. I only use Alps single gang in my builds.
> 
> Tom


"And relief washes over me in an awesome wave." Oh my goodness! Either I had a flawed Alps 100KAX2 pot or a flat out counterfeit. Thank you so very much Tom (Paladin79) for your generosity and kindness to help me fix this problem. My new Alps pot turns butteryyyy smooth--no more cheap, rough turning. Also, stereo separation is noticeably wider and instruments more distinct. So, there was definitely something wrong with my old pot. But that's all over now, and it's just my music and me. Thanks again, Tom. I just can't say it enough.


----------



## Paladin79 (Sep 14, 2017)

I am so glad it worked out well for you. I was fairly confident that was the issue but I did not feel right telling you to go buy another pot so the solution I offered was more logical in my mind. The lugs on those pots are made for mounting in PC boards so it is possible it got a little too hot during the soldering process.
 We once built two guitar cables for a gentleman and shipped them at different times. Same length, same cable, same connectors. He called to say one was louder than the other and it turned out to be true. My builder got one of the cables a little too hot and created a high resistance short that measured about 300k ohms. In a live test both seemed fine but compared to each other there was a difference. Sometimes in order to understand a process you have to enter into it and flow with it. (I am paraphrasing Frank Herbert's first law of Mentat..Dune).


----------



## Paladin79

attmci said:


> Por que o idiota não pode construir um amplificador ainda aqui?
> 
> Estou só brincando. Usei o google tradutor e diz algo que não pretendia dizer.



LMAO, that is funny and also quite intelligent since you used Portuguese and not Spanish. I try to avoid trouble with the moderators and I deleted several responses before I finally decided on something to say.


----------



## Renato Fury (Sep 14, 2017)

attmci said:


> Por que o idiota não pode construir um amplificador ainda aqui?
> 
> Estou só brincando. Usei o google tradutor e diz algo que não pretendia dizer.


The idiot here already explained why he can not build one, unless you're still an illiterate I'd understand, but rest easy because I'm just kidding.


----------



## Renato Fury

Well, since I'm the only jerk in the world who can not build one then I just have to buy Project Ember II "already built", but would anyone know how I could make Ember sound as close as possible to the sound of Bottlehead Crack ?


----------



## ProfFalkin

Look, if you're not going to buy a Crack, and you have nothing meaningful to contribute about the Crack (which you haven't to this point), then perhaps you should go annoy talk to the people in the Project Ember thread.  Ok?


----------



## Renato Fury

ProfFalkin said:


> Look, if you're not going to buy a Crack, and you have nothing meaningful to contribute about the Crack (which you haven't to this point), then perhaps you should go annoy talk to the people in the Project Ember thread.  Ok?


If you answer my question I will stop talking about Project Ember II. OK ?


----------



## Paladin79 (Sep 14, 2017)

Buy a Mullard-Webcor 12au7 tube, swap it for the one that comes in the Ember and you are all set. Enjoy the amp in good health, be well and prosper, bye.

During lunch I need to run by the Ford dealer and ask him why he is not selling Cadillacs and ask them what I will have to change in order for them to be the same. Mind you I am not a mechanic and am incapable of changing many things on a car but yet I want him to answer me anyway.


----------



## Paladin79

Any chance of a sale on Crack amps coming about in the near future? I believe the sale early this year was on an anniversary of some sort.


----------



## ProfFalkin

Paladin79 said:


> Any chance of a sale on Crack amps coming about in the near future? I believe the sale early this year was on an anniversary of some sort.


Or one on the crackatwoa?   Because... you know... capacitors.


----------



## Paladin79

I asked cause I saw Doc B. listed below but he might be reading some of the earlier posts, or like me just keeps this program open sometimes and goes on to do other things.


----------



## larcenasb

Paladin79 said:


> I am so glad it worked out well for you.


Hey Tom, I went ahead and installed the preamp mod tonight! I just realized you are who I talked with months ago about quality cables and you said a Belden factory is close by you--I realized this when I saw the cable you sent me was a Belden! 

About the amp: Ideally I'd have put the output jack closer to the RCAs but it was a bit crowded in that area, so I opted for an open area towards the middle. Take a look! All I have is my receiver with my HT system to test the preamp performance and still...I LOVE IT! The mods and tubes I have really breathe a sense of renewal into my HT. I watched _Kubo and the Two Strings_ and was just blown away at the atmosphere and sophistication coming out of my modest HT system now. So, I'm off researching to get a second-hand amp (maybe an Acurus A150 or Nakamichi PA-5) and some nice stand-mount speakers to really take advantage of this new functionality for my workstation/studio set up. Somebody should tally how many thank yous this will be...thank you, Tom.


----------



## larcenasb (Sep 15, 2017)

I'd have a hard time fitting much else into my crack now. Lmao, I had to. 

P.S. Sorry for just using my camera phone, sometimes I'm not in the mood to get out my lenses and all.


----------



## ProfFalkin

larcenasb said:


> P.S. Sorry for just using my camera phone, sometimes I'm not in the mood to get out my lenses and all.



INEXCUSABLE!!!   What man.    

Good lord, yeah you have no room left.   How do you like the sound there, and what are those blue caps?


----------



## larcenasb

ProfFalkin said:


> INEXCUSABLE!!!   What man.
> 
> Good lord, yeah you have no room left.   How do you like the sound there, and what are those blue caps?


Hahaha, I'll take proper photos once I get my amp and speakers to complete the setup!

I love the sound coming out of my AKG K240 Sextetts, sincerely I do. My fully-modded crack drives them with supreme confidence, and gracefully as well, making listening each night truly rejuvenating. Furthermore, I love letting friends and family listen, most of them have never heard audio through tubes before (let alone high quality audio) and the wow factor that you can see lighting up their faces is really satisfying. 

Those blue caps are 4.7uF ClarityCap PXs bypassing the first two power supply caps. It's hard to say with scientific confidence how much any one upgrade does to the sound, but all the power supply upgrades together (Choke, Cree Schottky diodes, all the caps and bypass caps) clearly makes my amp more dynamic, airy and effortless sounding, while also making the background quiet even when dialing the volume to max.


----------



## Paladin79 (Sep 15, 2017)

I am impressed by the installation of all of those components and you did a very neat job of installing the pre-amp line. I have a separate home theatre system but I do use the Crack as a preamp into Martin Logan powered electrostatic speakers and through a NAD amp and Polk audio speakers. I also use a Schiit Valhalla 2 as pre-amp into the Crack amp. I built a custom switch box so I can switch back and forth between the devices. Personally I prefer Binaural plus music for headphones but otherwise I have in excess of 35k albums in various formats. I prefer the tube sound so somewhere along the line I end up using that through my stereo system. If you run out of room in that box you can always do what I did with the black amp, stack two Crack cabinets, glue them, use filler to conceal the seam and then use a high gloss lacquer paint. Roughly 15 coats, sanding between each but I am guessing at number of coats.

I am trying to get a bunch of high end capacitors from a supplier in Florida but with the hurricane, it may be a while before I accomplish this. I will probably seek your advice on some of that Larcensab but I am open to any suggestions. I should be shipping the black amp to my son fairly soon and I will most likely let him worry about capacitor upgrades (I taught him enough electronics so I have no worries with him making the changes.) I learned about the preamp setup from Iluvmusic2 so I would not take credit for that. Before I started building a Crack I knew I wanted more space (larger cabinet), dual volume controls (I greatly prefer them), VU meters for looks, and a clean top other than tubes and transformer. I am always plugging things in and out and I did not like the idea of reaching around tubes for switches or cables so all Crack amps I build will most likely be this design. I used the original crack top plate for the black and carbon fiber amp and just covered over the holes I did not want to use, that part was quick and easy and not overly expensive.

Oh yeah as I said before the preamp out can double as another headphone jack, I am constantly letting friends and family listen to the crack amps and being able to plug in two sets gives me a chance to monitor the music I expose others to. I experiment with many types of wire for headphone cables so the more plug ins I have the better lol.

I do use a lot of Belden cable and most likely did talk to you about it a while back. I am on the DIY cable thread here a lot and I try to answer what questions I can. I certainly used a lot of it in my Crack builds.

It would be fun to mount either a dac or an amp in the above box, probably not a Crack amp unless I drastically changed the layout and spread it out more.


----------



## larcenasb

Paladin79 said:


> I am impressed by the installation of all of those components and you did a very neat job of installing the pre-amp line.


Thank you! Yeah, like with my evolutionary pictures from the first build to now with all the mods, I slowly got better at cleaning things up! This was a great experience for me to learn that and so much more.

I would be very happy to give some advice, or at least my experience and reasoning for each of the cap upgrades. Let me know anytime!

Oh, I was wondering what you did for the tall wood bases...stacking is a good idea, your amp looks so potent and serious that way! I really like your custom natural wood base too.

One day as perhaps my final mod, I think I'll add VU meters into the wood as you did. Having them be detachable as well so I can access the underside no problem. And wow, then--this is a bit difficult to say with the lump in my throat--that would complete my amp.


----------



## Paladin79

The amp I am keeping is made out of inch thick quartered oak. It is not quite as tall as the two stock cabinets stacked. The neat thing is, there is a guy on Ebay who sells the solid copper plate in exactly the size I wanted. I think the normal plate is six by eleven inches (I do not have one here to measure), the front and back plates are four inches square and you definitely need a taller cabinet for those to look right. My son has very specific tastes and lots of black furniture so I knew I would be doing laquer on his and I already had the two stock cabinets laying around. I do believe Bottlehead sells them as such if you ever want to go that route. I will be building two more and at least one will be polished copper with the quartered oak for which I was offered four figures so I really need to take my time on that one.


----------



## larcenasb

Paladin79 said:


> I do use the Crack as a preamp into Martin Logan powered electrostatic speakers...



So, I was thinking of getting a Bottlehead Kaiju amp and Harbeth P3ESR mini-monitors to go with my Crack preamp, but then I thought perhaps that's overkill lol. Yet you use the preamp with ML electrostats! You don't feel you're missing anything from your electrostats with the Crack in the chain? I mean, I know my Crack is a pound-for-pound great with all the mods and my beloved 6F8G tube collection, sounding refined and highly resolved; though, I'm just trying to choose the right path for my speaker set-up that will last a lifetime.


----------



## Paladin79

I have hooked up the Martin Logans four or five different ways and I like the richness and warmth of the tube sound from he Crack but that is just me. I also run a Klipsch powered subwoofer with that configuration and with lossless audio I am hard pressed to find a way to make it sound objectionable. This probably sounds silly but I like to be able to run quality headphones or remove them with the speakers going and experience similar quality. What I do not get with the speakers is the instrument spacing that headphones give with binaural music. Have you ever felt like you could tell if a performer was standing or sitting? I have had that feeling a few times with the right music.


----------



## larcenasb (Sep 15, 2017)

Paladin79 said:


> I have hooked up the Martin Logans four or five different ways and I like the richness and warmth of the tube sound from he Crack but that is just me. I also run a Klipsch powered subwoofer with that configuration and with lossless audio I am hard pressed to find a way to make it sound objectionable. This probably sounds silly but I like to be able to run quality headphones or remove them with the speakers going and experience similar quality. What I do not get with the speakers is the instrument spacing that headphones give with binaural music. Have you ever felt like you could tell if a performer was standing or sitting? I have had that feeling a few times with the right music.


Awesome to hear how well the Crack holds its own while partnered with more expensive components. And wow, I've never had the pleasure of being able to tell if someone is sitting or standing while listening! Once I get Harbeths one day and perhaps Beyer T1s, maybe I'll get there. 

Also, I realize the Kaiju and Harbeth P3ESR aren't the best pairing given that the Harbeth's sensitivity is just 83.5dB. I may get a solid-state amp instead (like the Acurus or Nakamichi mentioned before). But the Kaiju would be a great next step in kit difficulty, and is so beautifullll!! We'll see.

P.S. I love the rich, warm sound of the Crack as well, so I think your experience is helpful to me.


----------



## Paladin79 (Sep 16, 2017)

IMHO you can hear it in some of the Chesky recordings and because they are binaural plus, they sound decent over speakers as well. Here is a better pic of the black amp I made, it is hard to get the effect of the carbon fiber in some photos. I am by no means the first person to use copper or carbon fiber on a Crack but mine are a little unique with the use of the three plate system and I strive for symmetry.


----------



## ProfFalkin

Paladin79 said:


> IMHO you can hear it in some of the Chesky recordings and because they are binaural plus, they sound decent over speakers as well. Here is a better pic of the black amp I made, it is hard to get the effect of the carbon fiber in some photos.


Very nice!


----------



## attmci

Nice Q&A about crack amp: https://bottlehead.com/smf/index.php?topic=10291.0


----------



## JamieMcC

Two words for you guys who want to run speakers and headphones

 Bottlehead Sex

 Its a absolute steal performance wise for what it costs.

p.s

The BH Mainline makes for a amazing preamp as well


----------



## Paladin79

There is an upgraded Sex as well as a Mainline kit on ebay right now for decent prices. (The Sex is at auction and the Mainline buy it now.)

I like the idea of upgrading the Crack a bit at a time as Larcenasb did but I may  well build the others down the road once I build some other Crack amps that I have committed to build.


----------



## larcenasb

Paladin79 said:


> There is an upgraded Sex as well as a Mainline kit on ebay right now for decent prices. (The Sex is at auction and the Mainline buy it now.)
> 
> I like the idea of upgrading the Crack a bit at a time as Larcenasb did but I may  well build the others down the road once I build some other Crack amps that I have committed to build.


Same! I one day dream of building a Mainline, but just as a sort of celebratory Epicureanism, taking in the grandness life has to offer lol. That said, I am in no way dissatisfied with my Crack.


----------



## Paladin79

Once i have sold the last of my builds i will certainly consider it. I am pretty pragmatic, right now I have a couple stock picks starting to go through the roof and I am trying to dump all money I can into them before they get cost prohibitive. I have five preamps so it is not like I am hurting for one. 

Larcenasb what brand are your output caps?  I am considering Mundorf but they are specialty items that my normal distributors do not carry.


----------



## larcenasb

They are Audyn Q4 (68uF 250V) caps, and a matching third as the last PS cap. I've never bypassed the outputs; some say it's worthwhile, some say leave the output path pure. I did bypass 1/100 the last PS cap though with a Jantzen Superior-Z. Not only are neither of these caps terribly expensive, but they are really challenging the competition. For example: the German-made Audyn Q4 MKPs are cheaper than the very basic Dayton MKPs, and the Jantzen Superior-Z is cheaper than the Mundorf Supreme. In my research, in both cases, the cheaper caps were also perceived as the better ones. But of course this is probably extremeeeeeeely subtle!

Have you seen Humble Homemade Hifi's cap test? (http://www.humblehomemadehifi.com/Cap.html) I know it's just one source, but it's an exhaustive one that people generally look to as a reference--it may be useful to you. Cheers!


----------



## Paladin79

Thanks for the info Larcenasb, I will start to check out some of the caps. I had not seen that cap test before but will read up on it as time allows. My son is interested in an Elekit TU8600 300B amp so I need to look into that as well.


----------



## attmci

larcenasb said:


> They are Audyn Q4 (68uF 250V) caps, and a matching third as the last PS cap. I've never bypassed the outputs; some say it's worthwhile, some say leave the output path pure. I did bypass 1/100 the last PS cap though with a Jantzen Superior-Z. Not only are neither of these caps terribly expensive, but they are really challenging the competition. For example: the German-made Audyn Q4 MKPs are cheaper than the very basic Dayton MKPs, and the Jantzen Superior-Z is cheaper than the Mundorf Supreme. In my research, in both cases, the cheaper caps were also perceived as the better ones. But of course this is probably extremeeeeeeely subtle!
> 
> Have you seen Humble Homemade Hifi's cap test? (http://www.humblehomemadehifi.com/Cap.html) I know it's just one source, but it's an exhaustive one that people generally look to as a reference--it may be useful to you. Cheers!



Those test are based on speakers.


----------



## larcenasb

Yes, different application, but I use it just as a reference comparing one cap to another. If A handles the signal better than B as a speaker crossover cap, it's reasonable to assume A will handle the signal better than B as an output cap.


----------



## i luvmusic 2

When it comes to Capacitors i like using the SOLEN I have used the Mundorf film caps and compared it to the Solen i did not hear a difference.


----------



## larcenasb (Sep 18, 2017)

i luvmusic 2 said:


> When it comes to Capacitors i like using the SOLEN I have used the Mundorf film caps and compared it to the Solen i did not hear a difference.


*Output Capacitor Options:*

I was just now writing this for Paladin79, but this may be useful to others looking to upgrade. Humble Hifi's cap comparisons really are a lot to take in. Here is a sifted list of the common, and some not so common, 100uF caps, many of which other Crack builders have tried. So, based on all my research before starting my own build, this is how I'd break down 100uF output cap options (in bold are my picks within each tier):

Tier 1 (Sensible):
- *Audyn Q4 400V $24* (Pretty big, mine are only 68uF...)
- MKP-kondensotor 250V $27 (They seem cheap, but hey they're an option.)
- Dayton MKP 250V $32
- Jantzen Crosscap 400V $32

Seeing as the general consensus is that _any _MKP cap would be sufficient,--since the effect of film over electrolytics is subtle here--it's hard for me to justify not choosing the German-made, crazy-inexpensive Audyn. But life has so much to offer lol...

Tier 2 (I wonder how much nicer these are exactly...):
- *Obbligato Film Oil 630V $36* (68uF is the highest capacitance for these, so make sure you won't be using lower-impedance cans...which you shouldn't be anyway. Also, they're big and require a larger wood base, or some creative mounting, to fit. I'm curious how the oil will affect things.)
- Ansar 100uf 450V $40
- Solen 400V $41
- Mundorf MKP 250V $41 (For the pair, you'd be spending $34 more than you would for their German brother Audyns. I'd like to do a double-blind test!)

Tier 3 (Splurging):
- ClarityCap PX 250V $51 (Big, requires a larger wood base.)
- Mundorf EVO 350V $60
- Mundorf EVO aluminum + oil 350V $68 (If I built an ultimate Crackatwoa, I'd be curious to try the Obbligatos or these just to see what, as Audyn calls it, the "fairy-like oils" are all about hahahaha.)
- *ClarityCap ESA/CSA 250V $90!* (Also very big. I have a suspicion that all the previous MKP, non-oils, are indiscernibly similar. But these ones stem from a very rigorous two-year research program "on the audible effects of improved control over mechanical resonance [microphonics] in a metalized film capacitor," and "employs a non-standard polypropylene film." So, I'd like to do another double-blind test with these haha.)

Tier 4 (The land of irrationality!):
- Mundorf EVO silver/gold + oil 350V $360 ($720 for a pair lol...)

To sum up:
I picked the Audyns because of price and reason. Furthermore, having a matching third as the last PS cap was decided after I read, designer at Bottlehead, Paul Joppa's post on the BH forum:

_"The output audio current flows through the power supply, mostly the last capacitor, as well as through the output coupling cap and the output triode. So the final power supply cap should, in theory, be as important as the output coupling cap with regard to the sound of the amp. This is a characteristic of cathode follower circuits, such as the Crack and the Foreplay." _

_"I post this with some frequency: 'I never met a power supply improvement that was not also a sonic improvement.'"_

Continuing on, then bypassing the last Audyn in the PS was a nicety, sure, but the Jantzen Superior-Z is only about $15 ($12 for my 0.68uF version) so I could deal with that as a single upgrade. One day though I hope to get an Audyn True Copper 0.68uF ($45-ish) to replace the Jantzen--only because I've come to really admire Audyn as a company and it would be a nice kingly crown for my much-beloved build. Cheers!


----------



## larcenasb

Paladin79 said:


> Thanks for the info Larcenasb, I will start to check out some of the caps. I had not seen that cap test before but will read up on it as time allows. My son is interested in an Elekit TU8600 300B amp so I need to look into that as well.


No problem! I was considering getting an Elekit TU-8100 and some full-range Fostex speakers...until you helped me with the preamp circuit for the Crack! Now I'm looking for a separate amp and speakers to go with my Crack instead.


----------



## Paladin79

I have a good source for caps at a decent price so I may do a few upgrades before I ship the carbon fiber Crack, my Crack has more space as well and I will get a better discount buying the caps ten at a time anyway so I may well do both quickly and have some spares for the next couple Cracks I build. That was not part of my original deal but if i can upgrade the last two for under $100 each I will probably go for it. If I build a TU8600 I have a feeling I will end up owning my own after I hear it, then there are all the nice upgrades lol. $2k can be used up pretty quickly on those amps.


----------



## Paladin79

i luvmusic 2 said:


> When it comes to Capacitors i like using the SOLEN I have used the Mundorf film caps and compared it to the Solen i did not hear a difference.



Solen is another brand I can get a decent buy on, they make a 100 ufd 400 v cap that I may have to consider.


----------



## mcandmar

They also come in 250v which would be easier to package into a Crack chassis.

https://solen.ca/products/capacitor...eries-metallized-polypropylene/solen-pa10000/


----------



## Paladin79

They would most likely cost less as well. One of my amps has double the normal amount of space of a normal cabinet, the other is close behind. I had seen photos of some of the caps that folks tried to position in a normal case and knew going into this that it would be one of three or four major modifications I would make before building the amps.
 The next two I build will be more in line with the one on the right so unless I get caps larger than a 12 oz coke can I should be fine lol. I once nearly built a Tesla coil using a bucket capacitor. Consider a capacitor being a five gallon bucket of motor oil and associated parts. My wife was a little worried about the cats getting too close, or the three foot long discharge igniting something in the garage so the idea did not reach fruition. Some women just have no sense of adventure.


----------



## Paladin79

Ok my next Crack build is going to be really radical as far as the internal workings of the amp. I have some parts left over from the first couple Crack builds so I may incorporate some of those. I once heard that if you rebuild enough carburetors eventually you will have enough left over parts to build one from scratch. That is one of the principles I will use in the build. I have been asked to make one major change on the amp that in all honesty, I have not seen done before. The amp is for an electrical engineer so I have been given criteria to meet and there is a wager involved so we will see how it goes.  (he is also going to hand me a box of parts I must incorporate in the build.)


----------



## larcenasb

Paladin79 said:


> Ok my next Crack build is going to be...


Excited to see your build! Maybe it'll inspire me to make another or an ultimate Crackatwoa!


----------



## Paladin79 (Sep 22, 2017)

I can only say it will be one of a kind and may involve toroidal transformers, massive amounts of copper plate. and cold cathode displays (nixie tubes).


----------



## Voyst

Hello guys,

I really apologize for the following noob question which I imagine has been ask a 1000 times, but I am not willing to read all the 500+ pages...
I just bought a Crack + Speedball and of what I understood the TS 5998 seems to be the consensus for the output tube. Unfortunately, it is expensive and kind of hard to get (If you have reliable places to buy one <100€, please share). So I was wondering if there is a consensus on budget and easy to get tubes ? The amplifier will be paired with an HD650.

Thank you very much by advance


----------



## Paladin79 (Oct 5, 2017)

I have had good luck with some older RCA tubes but I will have to check to see what series they are when I get home. I also have some Russian tubes arriving shortly that I wanted to check out and if they pan out well I will give you the sources for both types. I do have Tung Sol 5998's but personally I cannot tell much difference between those and Chatham 6080's and others I have tried but YMMV. Most of my sources come from Ebay and thus far I have been pretty fortunate with the results but I generally buy from folks with only a couple tubes for sale here and there that I take a chance on.

Good luck with your build by the way. With the current sale going on you are jumping in at a good time. My builds are a little radical but there are many experienced builders here who can walk you through proven modifications if you want to go in that direction.


----------



## attmci

Voyst said:


> Hello guys,
> 
> I really apologize for the following noob question which I imagine has been ask a 1000 times, but I am not willing to read all the 500+ pages...
> I just bought a Crack + Speedball and of what I understood the TS 5998 seems to be the consensus for the output tube. Unfortunately, it is expensive and kind of hard to get (If you have reliable places to buy one <100€, please share). So I was wondering if there is a consensus on budget and easy to get tubes ? The amplifier will be paired with an HD650.
> ...


Try this:

http://www.ebay.com/itm/VINTAGE-TUN...277128?hash=item48a2945bc8:g:reAAAOSwXQZZdRTD


----------



## Paladin79 (Oct 5, 2017)

They are RCA 6AS7G's that I own that I really like the sound of. I found them on Ebay as a one time buy so I cannot say who has any now. You want to look for the ones with the old RCA symbol inside a circle with a lightning bolt under the letters. (I worked for RCA years ago and could have probably owned a huge sign like that if I so desired, I was there when they went to the block capital letters on the building.) The tubes also say Radiotron Electron tube on them.

http://www.ebay.com/itm/6AS7-6AS7G-...029097&hash=item56a09cc362:g:uFEAAOSwnB1Zp1uH

This style. They also say RCA in large capital letters but it is not the new RCA logo developed in the 70's I would guess.


----------



## Maxhawk

My favorites are the Chatham 6080 graphite plate, Sylvania 6080GB, and Cetron 7236. The 5998 is a good tube if you're looking for tighter, better defined bass since it has a lower output impedance compared to the other 6080/6AS7G variants.


----------



## Paladin79 (Oct 5, 2017)

I have some of the Chatham and Sylvania  as well, we all have our favorites. I have the ability at this time of switching back and forth between two crack amps that I have modified to be as identical as I can make them (electronics wise),.I can use my ears as well as an oscilloscope to track the sound. I will not have that opportunity when i ship one of the amps to my son with a set of tubes and no doubt his reaction will be different than mine to the tubes. My newest Crack build will not be very recognizable as a Crack but it will allow for more experimentation with tubes.


----------



## attmci

Maxhawk said:


> My favorites are the Chatham 6080 graphite plate, Sylvania 6080GB, and Cetron 7236. The 5998 is a good tube if you're looking for tighter, better defined bass since it has a lower output impedance compared to the other 6080/6AS7G variants.



Chatham 6080 graphite plate could be a bendix.

Clear top 5998 is better than tube labeled 5998/421A.


----------



## Doc B.

The most bang for the buck, easy to get, good sounding tube is the one that comes with the kit. Give the amp a chance in stock form before making arbitrary changes.


----------



## Paladin79 (Oct 6, 2017)

I do believe I received Sylvania and RCA 6080's with my kits so far, fine tubes indeed and buona fortuna with the current sale Doc.


----------



## i luvmusic 2

I agree with the stock tube my kit comes with GE 6080 and RCA 12AU7 and it sound nice after many hours of playtime,The Crack is nice to tube roll with it i've been using C3g,6SN7,6CG7 and some other 7 pin tubes that i have.


----------



## Paladin79

I imagine the 6080's vary a bit but they were good solid tubes with plenty of life regardless of the kit inclusion. I hope to have a third amp completed by Thanksgiving and if all goes well I will ship my son's out next week (carbon fiber and black lacquer.)


----------



## attmci (Oct 6, 2017)

I cannot imagine some one will go direct to a 5998 without trying a stock tube first. 

But after you had tried a 5998 etc, those stock tubes would be in storage at least for me. Hope Doc. B will recycle those tubes.

But I think you may also want to change those 5 buck electrolytic capacitors first.

*The crack is the best amp at its price.*


----------



## Doc B.

Speaking of price, you guys might want to check it.


----------



## Paladin79 (Oct 7, 2017)

I get the newsletter, $199 for the amp till October 9th is hard to beat. With the kits shipping 4-6 weeks later, it would be a fun little wintertime project for those who have not built the amp. Add your own personal touches and end up with a one of a kind Crack amp.


----------



## Paladin79 (Oct 8, 2017)

I was asked to incorporate a couple of these into my next Crack build so it is time to experiment a bit. As best I can tell they were called magic eye tubes. This build will be seriously steampunk and should be pleasing to the eye as well as the ear.


----------



## controllerboy

My heart skipped a beat on thursday. Received the crack+speedball I ordered about a month earlier, went to the website to download instructions and saw the fresh news of the sale. 106 euros saved if I had just waited one more month 

Anyways, I'm building my first crack now. Since I've done a few projects before, I'm not a total beginner, but I'm confident that just about anyone can make this thing.

Heck, with this huge discount, I'm tempted to just order another one. Buy it now!


----------



## gwompki

I just ordered one Friday and am super excited to build.  I had been considering selling my HD-6XX but thought I owed it to them to try them from a Crack before I sold them on.


----------



## Paladin79 (Oct 9, 2017)

Those headphones will go well with the Crack no doubt. I may order an extra one just to use a speedball kit I never used. I am not crazy about the way the speedball mounts so I may redo that circuit on one amp, probably single board.

I have another on the way so this will be my fourth build. Hopefully Doc will have another record sale on the Cracks. The more that are out there, the more people are involved in doing modifications.


----------



## Paladin79

I just got some Russian 6H13C tubes (6ASg7) Svetlana tubes and while I have not checked all of them yet, the first is certainly impressive. I purchased four and they shipped five so that was a nice surprise as well. These are NOS. Tight bass, mids and highs are as good as anything I own. Once I match a pair, they will go into my next Crack build.


----------



## Doc B.

Paladin79 said:


> Hopefully Doc will have another record sale on the Cracks. The more that are out there, the more people are involved in doing modifications.



We did indeed. It was actually a little difficult to sleep the night the sale started because Eileen and I were both the getting transaction notifications from the phones on our nightstands every few minutes. They kept lighting up the room. Thanks to everyone who participated!


----------



## mcandmar (Oct 13, 2017)

Change the alert-tone to a cha-ching sound, you will sleep much better 

I had to skip this sale, think its the first October in years i haven't bought a Bottlehead kit for my Birthday.


----------



## Paladin79 (Oct 14, 2017)

I think one of those cha-Chings was mine but I am building amps for others in my rare spare time and this time I am not in a hurry for the last Crack kit to arrive. Tomorrow I start assembly on a barely recognizable crack. I have to stop accepting wagers and intimating that people have choices when I agree to build them a Crack.

This is my latest Crack build, I will be using polished copper, front and back plates for control knobs and inputs, tube type vu meters, antiqued cabinet using several wax applications. I will call this one the Gemini Crack and I imagine the layout hints at at least one new capability. There will be three major changes compared to a stock crack. This is a one time build then I will do a more standard Crack. (standard for me anyway.)


----------



## attmci

Paladin79 said:


> I think one of those cha-Chings was mine but I am building amps for others in my rare spare time and this time I am not in a hurry for the last Crack kit to arrive. Tomorrow I start assembly on a barely recognizable crack. I have to stop accepting wagers and intimating that people have choices when I agree to build them a Crack.
> 
> This is my latest Crack build, I will be using polished copper, front and back plates for control knobs and inputs, tube type vu meters, antiqued cabinet using several wax applications. I will call this one the Gemini Crack and I imagine the layout hints at at least one new capability. There will be three major changes compared to a stock crack. This is a one time build then I will do a more standard Crack. (standard for me anyway.)


Tom, What's this?


----------



## Paladin79

It is the early stages of an amp I am building for a friend. I am using left over Crack parts as well as some my friend provided. The circuitry will be similar to a Crack but I have been challenged to add some features to it. You will know a lot more when the front and back panels are complete.


----------



## attmci

Paladin79 said:


> It is the early stages of an amp I am building for a friend. I am using left over Crack parts as well as some my friend provided. The circuitry will be similar to a Crack but I have been challenged to add some features to it. You will know a lot more when the front and back panels are complete.


looking forward...


----------



## Paladin79

Thanks, my fourth Crack build will be more traditional, I will be pushing the limits of dual 12AU7's and 6AS7G's to get the desired results. I also need to generate 240v DC for the dual magic eye tubes ( one of the curveballs I was thrown) but a bet is a bet.


----------



## attmci

Paladin79 said:


> Thanks, my fourth Crack build will be more traditional, I will be pushing the limits of dual 12AU7's and 6AS7G's to get the desired results. I also need to generate 240v DC for the dual magic eye tubes ( one of the curveballs I was thrown) but a bet is a bet.



Are you using a new transformer? I doubt the stock transformer  (heat current ~3.5A) can support dual 12AU7 and 6AS7G. I cannot/am not dare to use even two 6bl7 and a 6SN7.


----------



## Paladin79 (Oct 14, 2017)

Two new transformers that were supplied to me. There is a wager involved and I will need to think through a few things to pull this    off, but I like a challenge and I like my odds. Once you see the jacks on the front and back I bet you figure out what two of the goals are.


----------



## i luvmusic 2

Now I'am interested on the "CIRCUIT DIAGRAM" a PM of copy would be nice....

Thanks!


----------



## Paladin79

It is a little early for that, I am still in the planning stages and parts of the design may not be mine to share.


----------



## i luvmusic 2

F@#K speaking of schematics i just lost/misplaced(DIY and  the CRACK schematics) mine......


----------



## i luvmusic 2

Paladin79 said:


> It is a little early for that, I am still in the planning stages and parts of the design may not be mine to share.



No worries/rush when ever it's ready,THANKS Tom!


----------



## Paladin79

Here is enough info on the front and back plates that should reveal two of the things I am going for in the build. I will not be using the chicken-head knobs but just slapped them on the dual volume controls for the time being. In between said knobs are a quarter-inch stereo jack and a standard size four pin XLR female. On the back plate there will be the obvious speaker jacks as well as dual three pin xlr females, four RCA jacks, AC input jack, etc. Now there will be a small toggle switch on the front as well and one on the back but that is work for another day. It has been a while since I have laid out and made a pc board but there will most likely be one in the power supply section with all supply voltages well marked. My trusty watch dog Woodstock is guarding the build, cave canem.


----------



## Paladin79 (Oct 21, 2017)

My amp build is starting to be less Crack like so I may have to move it to another thread. There is a good chance I will be using four 6AS7G tubes in the build. I am using a 12 inch square top plate to allow for such changes.

I did come across some little plates that can be mounted behind Neutrik connectors. At the top they have a little area that will accept letters so I will be able to mark the left and right three pin XLR's on the input plate of my amp. One is shown on the bottom copper plate and above it is the style Neutrik jack I can use with it.  Luckily Neutrik makes RCA jacks in the same configuration


----------



## Paladin79

Opinions needed..

I was getting some scratches in the front plate so I went ahead and added a patina after a couple hours trying to buff them out. Do I :

A. Use patina on all plates including the top?
B. Start all over with front and back plates and keep them shiny?
C. Do a combination of patina on front and back plates only and keep shiny copper on top?

The patinization really jumps out against the waxed grey cabinet but so does the copper.


----------



## DavidA

One vote for option C, its a nice contrast


----------



## Paladin79

Thanks David, I am leaning toward that direction. I can now get the proper level of patinization in about five hours and it is so much easier to not have to try for a high gloss copper finish. I will clear coat the top to maintain the shine and then start on the electronics. I have so many inputs and outputs on the back I will have a third side plate for AC input and power switch. The blade switch on the top will be functional but I will probably just use it to control the magic eye tubes in the front row.


----------



## DavidA

Paladin79 said:


> Thanks David, I am leaning toward that direction. I can now get the proper level of patinization in about five hours and it is so much easier to not have to try for a high gloss copper finish. I will clear coat the top to maintain the shine and then start on the electronics. I have so many inputs and outputs on the back I will have a third side plate for AC input and power switch. The blade switch on the top will be functional but I will probably just use it to control the magic eye tubes in the front row.


Do you have access to a photo studio or some where with a seamless background and controlled lighting?  I'd love to see your creations in a nice product shoot since they are quite beautiful/imaginative in design.


----------



## Paladin79 (Oct 24, 2017)

I can probably get some better quality photos later on. I already shipped one amp to my son and my current build will be shipped out once completed as well but it is going to take some time. I have not thought through all of the electronics yet but at least all the tubes, jacks, and pots are in place. Right now it is mostly on my workbench cause it is a work in progress.

 My amps look a lot better if you stand back a ways and squint your eyes but I will see what I can do. Oh yeah if I get all the features going on this particular amp it will most likely be one of a kind unless the recipient wants to go into production on them, this is a bit of a beast to build quickly.

Here is an example of patina that I achieve in about 5-6 hours. I need to brush off the excess and clear coat it but the process produces some wondrous colors.

Here is also a top view with tube and transformer layout. The transformer covers have vents and I am using toroidal transformers. I still have to figure out some top vents for the top copper plate, mount and wire the blade switch, make a circuit board and then wire everything. Cabinet is twelve inches square and about six inches tall so I have plenty of room inside.



Tom


----------



## FunyunBreath

Finally finished the exterior of my build after a long time of kicking around different ideas, figured I'd post in here for inspiration


----------



## Paladin79

Nice job on the build. I particularly like the feet, I ordered a similar set in silver for a Crack I gave away.


----------



## FunyunBreath

Paladin79 said:


> Nice job on the build. I particularly like the feet, I ordered a similar set in silver for a Crack I gave away.


 Thanks! The cool thing is they looks awesome and they're actually pretty practical. I have a few power tubes that can be pretty microphonic and the feet isolate them really well from vibrations on my desk.


----------



## Paladin79

Do you mind saying where you got the feet? If not that is perfectly fine. Most of my builds are with copper or brass but I happened to do one in silver and black carbon fiber for my son and I have the feet coming out of China.


----------



## FunyunBreath

Paladin79 said:


> Do you mind saying where you got the feet? If not that is perfectly fine. Most of my builds are with copper or brass but I happened to do one in silver and black carbon fiber for my son and I have the feet coming out of China.



Yup! They're speaker isolation spikes from Dayton audio: https://www.parts-express.com/dayton-audio-iso-4g-gold-isolation-cone-set-4-pcs--240-720


----------



## Paladin79

Ahhhh I had seen some there and had not noticed the gold ones. I may grab a set for this amp, I just have sliders on it for the time being so I can easily turn it as I work on the build.I rarely have trouble with the electronics but it takes me a while to decide appearance. This is not a basic crack build of course but it contains many of those parts and there are circuit similarities.


----------



## DavidA

@FunyunBreath very nice build, also a great choice in the headphone


----------



## wolfmath

I'm having a little difficulty with my Crack. I've built it just fine, and it sounds awesome with my HD 650's. I am however having issues with the volume, and channel imbalance. Not a big problem, it's addressed in the Crack FAQ (I love the rhyme btw); it's numbers 3 and 4.  I just don't understand the phrase, "Attach and solder one 33K resistor between *each outer pair of lugs on each level of the volume pot and the ground lugs on the pot.*" 

_Where are_ each pair of lugs on each level of the volume pot and the ground lugs on the pot? I've been staring at the underside of my Crack for a long time now (LOL), and I can't figure out where those resistors are supposed to go! Any ideas?


----------



## Paladin79

I do not have photos or drawings in front of me but as I recall, the two lugs on the right with the black wire going through them are the ground for that control pot. Notice they are on top of one another so to speak? A dual ganged pot is nothing more than two pots of the same type sharing a common control shaft. The grounds are joined together but the red and white wires going to the pots are the right and left channels respectively so you can consider them sharing the same control shaft just like the ground lugs. If you go from the red wire or the white wire to the ground lugs with a resistor, you are affecting each channel equally. This is not balanced audio so there is a common ground just like when you wire a 3.5 mm or 6.5 mm TRS connector and there are three connections. I have not used the stock pots permanently in any of my builds and you could also just eliminate that pot and go with a dual gang Alps 100k audio taper pot, or do what I did and use two single gang pots then you can control each channel independently. Just remember on the pot you are using, left and right lugs are lining up the same way the ground lugs are and you should be fine.


----------



## gwompki

FunyunBreath said:


> Finally finished the exterior of my build after a long time of kicking around different ideas, figured I'd post in here for inspiration



That looks fantastic!  Very similar to what I have envisioned for my own kit that is incoming.  Do you mind sharing how you finished the case and the chassis?  The finishing aspect is probably the part I dread most since I have so little experience with it 

Also out of curiosity, will I receive a tracking number once the kit ships?  I ordered during the last sale so I know they got crushed with orders.  I think mine should ship sometime in the next 2 weeks since it has been around 4 weeks since I placed the order.  I'm very excited to put it mildly lol.


----------



## FunyunBreath

Paladin79 said:


> Ahhhh I had seen some there and had not noticed the gold ones. I may grab a set for this amp, I just have sliders on it for the time being so I can easily turn it as I work on the build.I rarely have trouble with the electronics but it takes me a while to decide appearance. This is not a basic crack build of course but it contains many of those parts and there are circuit similarities.


Man that looks sweet! What's under the hood on that?



DavidA said:


> @FunyunBreath very nice build, also a great choice in the headphone


 Thank you! Really liking the hd800s as well.



gwompki said:


> That looks fantastic!  Very similar to what I have envisioned for my own kit that is incoming.  Do you mind sharing how you finished the case and the chassis?  The finishing aspect is probably the part I dread most since I have so little experience with it


Yup! I used Krylon black hammered spray paint on the top chassis, transformer bell, and volume knob (about 4 coats or so). The wood base was actually incredibly easy, it's not stained or anything. All I did was sand to 220 grit and then I finished it with Briwax creamed beeswax applied with 0000 steel wool (about 3-4 coats)


----------



## gwompki

Thanks! I will definitely be taking a look at the Briwax approach.


----------



## Paladin79

I may try it out on my next Crack build. I ended up getting one cabinet a little darker than I liked. I will be using a similar design but I want the patinated copper to jump out more on my next build. I have more of this quartered oak and do not want it to go to waste.

so


----------



## Voyst

Hello everyone,

I have a very newbee question:
Which of the two tubes has the most influence on the sound signature ? The input (12AU7) or output (6080) tube ?

I ask that because i have several input and output tubes, and was wondering on which position i should roll first (in order to change only one factor at a time).

Of my understanding so far, it is the output tube which has the most influence. So I should roll between my 6080s and choose my favourite, and then roll 12AU7s and choose the best combo with my favourite 6080, right ?

Thank you very much in advance !


----------



## attmci

Voyst said:


> Hello everyone,
> 
> I have a very newbee question:
> Which of the two tubes has the most influence on the sound signature ? The input (12AU7) or output (6080) tube ?
> ...


Most of the people agree that the driver tube has more influence on a crack.


----------



## Paladin79 (Nov 26, 2017)

Agreed.

 I did a lot of side by side listening and testing, switching back and forth between two stock cracks. It made the most sense to me to do it that way and I did it over a period of time so I could give each combination a good listen but it is not for everyone. I was also fortunate to allow others to listen and give me their feedback but in the end I arrived at tubes that I love but I am doubtful my final selections would match those of other enthusiasts. I strive for a balance between subjective and objective.

You will also find that when buying new or used old stock, the sound and quality can vary between specific brands and builds depending on condition and prior usage. In dealing with old tubes you will find yourself needing to clean the tube pins to insure good contact. There are new, new old stock (if you can believe the seller), and used tubes. Keep your original tubes handy and go back to them when in doubt, they may well be better than some you find on the used market.

Just remember you cannot improve sound, you can only hope to maintain it and not diminish it.

Above is the start of my latest build. Try as I might I still like the looks of 1/8 inch copper and quartered one inch oak. This is the challenging part of a build for me and I have some new Alps pots I fell in love with on another build that I cannot wait to use. I may try for a brushed copper look but if that does not work out, a patina will hide most any imperfection.


----------



## attmci

Paladin79 said:


> Agreed.
> 
> I did a lot of side by side listening and testing, switching back and forth between two stock cracks. It made the most sense to me to do it that way and I did it over a period of time so I could give each combination a good listen but it is not for everyone. I was also fortunate to allow others to listen and give me their feedback but in the end I arrived at tubes that I love but I am doubtful my final selections would match those of other enthusiasts. I strive for a balance between subjective and objective.
> 
> ...


Tom, you forgot a very important thing here:

Cryo-treated tubes have “tighter focus from top to bottom”, “more holographic 3D soundstage”, “more subtle inner resolution extracted from recordings”, “tighter bass”, “increased dynamic range”, “faster transient response”.
Discussed here: 
http://www.effectrode.com/cryogenic-treatment-tubes-engineers-perspective/


----------



## Paladin79 (Nov 26, 2017)

Tempus sure does fugit, is it April 1 already?

  I have seen that article but it is best I do not say much here. I am not supposed to disparage against any product or products, I just tend to wince each time I hear Cryo this or that.

I will say I own many Mullard tubes and they are one of my first choices for drivers.


----------



## DavidA

Voyst said:


> Hello everyone,
> 
> I have a very newbee question:
> Which of the two tubes has the most influence on the sound signature ? The input (12AU7) or output (6080) tube ?
> ...


Which tube makes the most difference is also dependent on the headphone you will be using since the power tube influences the output impedance which will affect some headphones more than others while other headphones will be more sensitive to driver tube changes is what I've noticed so far.  @Paladin79 has a great suggestion of just using the stock tubes to start so you get familiar with how they sound with your headphones.  I've also noticed that how a tube sounds is affected by the speedball, I've removed my speedball since I like the sound without it with the set of tubes that I like most.


----------



## Maxhawk

The way I've heard it explained is that the input tube makes a big difference because it's the gain stage. The output tube will make a bigger difference as you lower the impedance of the load.


----------



## attmci

DavidA said:


> Which tube makes the most difference is also dependent on the headphone you will be using since the power tube influences the output impedance which will affect some headphones more than others while other headphones will be more sensitive to driver tube changes is what I've noticed so far.  @Paladin79 has a great suggestion of just using the stock tubes to start so you get familiar with how they sound with your headphones.  I've also noticed that how a tube sounds is affected by the speedball, I've removed my speedball since I like the sound without it with the set of tubes that I like most.


Tube rolling won't change your amp from a $400 equipment to a $1000 one.


----------



## DavidA

attmci said:


> Tube rolling won't change your amp from a $400 equipment to a $1000 one.


I never said it did but its a persons opinion that tubes can change a $400 amp to a $1000 amp and I think there are some who would say the proper tubes/caps/etc can make the BH Crack compete with some $1000 amps but its a personal preference / opinion to me.


----------



## JamieMcC (Nov 27, 2017)

Dont chase expensive input tubes do this simple inexpensive mod ($5) and you can run both 12au7 or e80cc at optimal voltages as specified by the PB the Cracks designer at the flick of a switch. Once you have tried E80cc you might never buy another12au7 again. 


https://bottlehead.com/smf/index.php?topic=5989.30


----------



## Paladin79

DavidA said:


> I never said it did but its a persons opinion that tubes can change a $400 amp to a $1000 amp and I think there are some who would say the proper tubes/caps/etc can make the BH Crack compete with some $1000 amps but its a personal preference / opinion to me.



In my limited experience working with the Crack amps, I have found performance and appearance to be factors in adding value to the basic Crack amp. I have mostly built the amps for family and friends but I have had several requests to build them for folks who have seen my work. One way of measuring what something is worth is what an individual is willing to pay and while I am not in the amp building business the offers have been fairly high for amps I may build. That being said, there was a fairly nice one on Ebay for about $900 that I kept seeing for a long time. I have been offered more but I do believe that hearing the amps makes a big difference in the selling process.

 I do not have the speedball in my steampunk styled Crack amp, I have heard them side by side and while the speedball does remove some of the background noise I am happy with the amp as it sits. I may add it to my next build but not in its current form, I want to build  my own pc board on which to mount the parts but that is just me. It should not change the performance any.


----------



## bloodhawk

Paladin79 said:


> In my limited experience working with the Crack amps, I have found performance and appearance to be factors in adding value to the basic Crack amp. I have mostly built the amps for family and friends but I have had several requests to build them for folks who have seen my work. One way of measuring what something is worth is what an individual is willing to pay and while I am not in the amp building business the offers have been fairly high for amps I may build. That being said, there was a fairly nice one on Ebay for about $900 that I kept seeing for a long time. I have been offered more but I do believe that hearing the amps makes a big difference in the selling process.
> 
> I do not have the speedball in my steampunk styled Crack amp, I have heard them side by side and while the speedball does remove some of the background noise I am happy with the amp as it sits. I may add it to my next build but not in its current form, I want to build  my own pc board on which to mount the parts but that is just me. It should not change the performance any.



Weird question, but do you know if it is possible to swap out the transformer in the Crack 1.0 with one that is compatible with (and can be rewired) 120V and 240V? Its almost impossible to get a hold of an original Bottlehead universal transformer, since they are custom wound for them. Plus i can make my own face plate to accommodate the size / shape differences.


----------



## Paladin79

I believe the newer transformers are 120v and 240v capable and Bottlehead may well sell you one. They are having a sale on some product so this would certainly be a time to check. If they will sell you one, they should fit without modification but you would have to get the 1.1 build info that covers the transformer wiring. Doc Bottlehead is on here on occasion and I am sure he can easily answer this for you or just go to the website and look under their spare part section.


----------



## bloodhawk

Paladin79 said:


> I believe the newer transformers are 120v and 240v capable and Bottlehead may well sell you one. They are having a sale on some product so this would certainly be a time to check. If they will sell you one, they should fit without modification but you would have to get the 1.1 build info that covers the transformer wiring. Doc Bottlehead is on here on occasion and I am sure he can easily answer this for you or just go to the website and look under their spare part section.



Gotcha. Yeach ill shoot Doc and email today. Ill be travelling to Asia for a few months soon, and would like to take my Crack along. Plus i can implement a flip switch to change between the voltages. Plus im planning on re-doing the wiring along with upgrading the caps etc. So might as well do this in one go as well. At least the Transformer swap and adding a choke at atleast along with adding the E80CC switch.


----------



## Paladin79

Unless you are going to be going back to Asia a lot you could just get a step down transformer for $35 or so and save yourself a lot of time and money. Just another option for you.

Tom


----------



## bloodhawk

Paladin79 said:


> Unless you are going to be going back to Asia a lot you could just get a step down transformer for $35 or so and save yourself a lot of time and money. Just another option for you.
> 
> Tom


Yeah thats what Doc also suggested. BUT BUT BUT... the tinkerer in me.... the idiot has this itch......


----------



## Paladin79

lol, Another option is sell the one you have, get a newer model on sale and convert that one. Good luck in your endeavor though.


----------



## bloodhawk

Paladin79 said:


> lol, Another option is sell the one you have, get a newer model on sale and convert that one. Good luck in your endeavor though.


Neah im actually fine with the current one. 
Its not too big of a deal tbh. The only reason i started looking into the transformer was because im tearing the whole thing down this weekend to upgrade a bunch of components and figured why not swap the transformer and the necessary parts from the Crack 1.1 as well, plus im working on a new face plate cut out, so its easy to accommodate for difference in dimensions.. Unfortunately its not possible to get the transformer, since it wont work in the Crack 1.0 (As i have been told... )
What i think about it not working , is a totally different story. But i respect Doc's decision, so all good. Ill turn it into a universal crack one way or the other


----------



## Paladin79

One source of happiness is working toward a goal and you definitely have a goal, good luck.


----------



## Paladin79

I do have another Crack kit arriving today but what with the holidays coming up it may be a while before I do much on the build. I have begun work on the cabinet and will start to cut copper plate when I can. It will be in this basic shape but the oak and copper will look very different.


----------



## bloodhawk (Dec 2, 2017)

Anyone have a picture of the Cree Diode Rectifier Board? (Both sides)
Would highly appreciate it.

Underside of this board to be exact - http://www.partsconnexion.com/media/product/kits/77727-1.jpg


----------



## bloodhawk

Finished some upgrades, while i wait for the TKD pot to come in along with the parts connexxion rectifier PCB. - 


Spoiler: Pikchur











Still debating if i should add a bypass cap to the last power supply cap or just replace it out right with a better 100uF cap.

A main question - How do i reduce the RFI going from the USB port to the DAC? Specially the coil whine from my GPU. My Crack picks up a lot of of that coil noise when the GPU is under load and hooked up to the desktop with the Origen +. I have a NFB11.28 coming in tomorrow, going to see if the interference persists with that. 

Also i have 3 x extra 2.2uF 250VDC Mundorf MKP Caps and 2 x extra 1uF 250VDC Mundorf MKP Caps coming in on Wednesday and since i dont need these at all as they are extras. If someone else wants them, Just send me a shipping label and ill be happy to give them to you. First come First Serve.


----------



## Faber65

ViKiD(TM) said:


> Finished some upgrades, while i wait for the TKD pot to come in along with the parts connexxion rectifier PCB. -
> 
> A main question - How do i reduce the RFI going from the USB port to the DAC? Specially the coil whine from my GPU. My Crack picks up a lot of of that coil noise when the GPU is under load and hooked up to the desktop with the Origen +. I have a NFB11.28 coming in tomorrow, going to see if the interference persists with that.



I don't know about your mods, but what if the noise would be generated in the power line?
Did you consider to use a filtered power entry module like this?

https://www.digikey.com/product-detail/en/schaffner-emc-inc/FN261S-1-06-10/817-1912-ND/1997733


----------



## bloodhawk

Faber65 said:


> I don't know about your mods, but what if the noise would be generated in the power line?
> Did you consider to use a filtered power entry module like this?
> 
> https://www.digikey.com/product-detail/en/schaffner-emc-inc/FN261S-1-06-10/817-1912-ND/1997733



Interesting, i haven't tried one of those before. 

But i kind off ruled out the crack or the power line, because when i connect the DAC feeding the Crack to anything other than my desktop any and all interference goes away. I didnt expect the DAC to pick up the interference over USB tbh., specially since when the headphones are connected to the Origen+ the background is pitch black. But using it as a Pre out the Crack, results in the coil whine being literally amplified.


----------



## SeNNsational

Hi, newly purchased Crack+Speedball owner here (unit is 9 months old, proffesionally assembled). Thanks for all the help in this thread for helping me decide to get it.

I have a question though that is niggling me on it. So I have a Titanium HD soundcard in my computer which I was using prior to this purchase and enjoying. It has a Burr-Brown PCM1794 inside it.
Now, I've routed it's DAC to the Crack with LC-1 3 ft cables and listening to it after warmup and using a few different 12AU7 tubes (6080 power) and I think I enjoy the output of the soundcard's headphone out on most songs, except high lyrics songs which I'll give to the Crack just about.

This seems wrong to me given all the suggestions that this would pair excellently with my HD6XX phones, which are about a week old with about 30 hrs in.

The "tube sound" seems to me a little bit muddled, rounded is all I can explain it as. The detail is there but I can hear that detail more clearly/cleanly and brighter out of the headphone jack of a 7 year old, now $70 soundcard that according to people in reviews shouldn't even be able to drive a 300ohm set of cans well.
I don't know if it's sign but the Crack also needs turning up to around 75% to what I consider "loud", with 100% output from the sc lineout. The Crack's 100% is louder than the sc 100% though.
There is no hum or other such noise from my Crack at 100% with silence coming from the sc lineout.


The Crack sounds good, and I wasn't expecting MASSIVE improvement but I thought it would at least beat the soundcard jack for the price and people's opinion it pairs so well with the HD650/6XX.

So what's the deal in your opinion? I know it's a tough question but am I just not used to or a fan of "tube sound" or is there something else going on?


I am contemplating a separate DAC but I dunno, I'm skeptical.


----------



## bloodhawk (Dec 4, 2017)

SeNNsational said:


> Hi, newly purchased Crack+Speedball owner here (unit is 9 months old, proffesionally assembled). Thanks for all the help in this thread for helping me decide to get it.
> 
> I have a question though that is niggling me on it. So I have a Titanium HD soundcard in my computer which I was using prior to this purchase and enjoying. It has a Burr-Brown PCM1794 inside it.
> Now, I've routed it's DAC to the Crack with LC-1 3 ft cables and listening to it after warmup and using a few different 12AU7 tubes (6080 power) and I think I enjoy the output of the soundcard's headphone out on most songs, except high lyrics songs which I'll give to the Crack just about.
> ...



You might want to try out a 5998 tube with a 6sn7 . Another option is a 5687 tube, but that will require a bit of modification for the correct plate voltage.

As for the DAC, i switched from the STX 2 to the Origen+ (still use the STX 2 for games) , and now to the NFB 11.28. The NFB 11.28 is the best out of the lot and really helps with improving the muddyness that you are referring to.

Im using this - Audio GD 11.28 -> Crack (JAN CTL 5998 Catham + RCA 6sn7)  -> HD6XX/HD800.


----------



## SeNNsational

Thanks. I do have a 6sn7 adaptor that came with it, but no tubes as yet. In Canada it seems hard to source them. I'll have to import.


----------



## i luvmusic 2

SeNNsational said:


> Hi, newly purchased Crack+Speedball owner here (unit is 9 months old, proffesionally assembled). Thanks for all the help in this thread for helping me decide to get it.
> 
> I have a question though that is niggling me on it. So I have a Titanium HD soundcard in my computer which I was using prior to this purchase and enjoying. It has a Burr-Brown PCM1794 inside it.
> Now, I've routed it's DAC to the Crack with LC-1 3 ft cables and listening to it after warmup and using a few different 12AU7 tubes (6080 power) and I think I enjoy the output of the soundcard's headphone out on most songs, except high lyrics songs which I'll give to the Crack just about.
> ...



My CRACK amp at 1/4 turn it's loud at 3/4 turn too loud it can probably blow my eardrum(Unlistenable),Do you have the resistor mod in the volume pot,Are you from GTA?


----------



## SeNNsational

I don't know for sure but I don't think so. I should have said at 50%+ it's starting to get loud, at 75% it is pumping and close to too much so it sounds like this is similar to yours. Thanks, that confirms that aspect is fine then it would seem.

I've been listening to it between 9 (1/4 turn) and 2 o'clock depending on source+style. I brought this up as I had read in some posts that there are others with similar setup who were uncomfortable listening with it set past 9 o'clock so I was wondering if mine was particularly off.

In Quebec.


----------



## i luvmusic 2

With mine at 10 o'clock really loud can't stand it,The reason i asked if you're from GTA i would like to let you try my DAC  before you start spending your hard earned $$$$ or maybe i can assist you with something else on your setup.


----------



## attmci

SeNNsational said:


> Hi, newly purchased Crack+Speedball owner here (unit is 9 months old, proffesionally assembled). Thanks for all the help in this thread for helping me decide to get it.
> 
> I have a question though that is niggling me on it. So I have a Titanium HD soundcard in my computer which I was using prior to this purchase and enjoying. It has a Burr-Brown PCM1794 inside it.
> Now, I've routed it's DAC to the Crack with LC-1 3 ft cables and listening to it after warmup and using a few different 12AU7 tubes (6080 power) and I think I enjoy the output of the soundcard's headphone out on most songs, except high lyrics songs which I'll give to the Crack just about.
> ...


Could be: 1) A very weak power tube. 2) master setting of your play back device.


----------



## bloodhawk

Got this doodad and hooked it up between the NFB11.28 and the Crack -

https://www.amazon.com/gp/product/B01A56CMUO/ref=oh_aui_detailpage_o02_s01?ie=UTF8&psc=1

Instantly got rid of any and all interference. 

Did an A/B test using a RCA switch and couldn't tell any signal degradation taking place with with the HD800 and HD6XX.


----------



## i luvmusic 2

I'am in the Process of making my first AUDIOPHOLE Power Bar using this Filter because My Crack,SEX and DIY amp is plug into the wall socket i can only plug-in 2 at a time.Has anyone here used this type of filter and what is the best type of connection for the filter SOLDERED or QUICK TYPE Connectors?Thanks!


----------



## Paladin79

You can use spade connectors if you make sure they are nice and tight on the connections. You can use long nose pliers to tighten them a bit if you have any issues. Soldering is more permanent and more trust worthy but if you are planning on unplugging things on occasion the spade connectors can be handy for that. I used some on the grounds on the inside of a couple Cracks I made. I then used molex connectors for audio pots and other wiring.


----------



## i luvmusic 2 (Dec 6, 2017)

Thanks!BTW i paid CAD$2.00 each filter that is why i end up with two


----------



## Paladin79

Very nice. It is great to see someone taking the time to do things for himself. I start another Crack build soon but most likely that will happen after Christmas. I just drifted into the realm of solid state amplifiers and balanced audio but I will return to tubes soon.


----------



## i luvmusic 2

SS and Balanced?You are lucky that one of the Head-fi member is not subscribe into this thread or else he will be all over you that guy is a Balanced audio fanatic.


----------



## Paladin79

I like to try lots of venues, I have done balanced with tubes as well. I am doing another steampunk Crack before long but my Christmas parties have me booked till January.


----------



## bloodhawk

Belly of the beast is now full of.. errm.. Crack ?


----------



## SeNNsational (Dec 8, 2017)

SeNNsational said:


> Hi, newly purchased Crack+Speedball owner here (unit is 9 months old, proffesionally assembled). Thanks for all the help in this thread for helping me decide to get it.
> 
> I have a question though that is niggling me on it. So I have a Titanium HD soundcard in my computer which I was using prior to this purchase and enjoying. It has a Burr-Brown PCM1794 inside it.
> Now, I've routed it's DAC to the Crack with LC-1 3 ft cables and listening to it after warmup and using a few different 12AU7 tubes (6080 power) and I think I enjoy the output of the soundcard's headphone out on most songs, except high lyrics songs which I'll give to the Crack just about.
> ...



To follow up on this, I tested my current set of tubes and my power (and a few of the input) tubes were microphonic. The RCA 6080 I had in, that isn't supposed to be very good in the first place rang like a bell when tapped with a little force from a pencil. So I changed that out for a NOS 6AS7G SED Winged C and a new-ish EH 12AU7 and it's night and day. Listening to the Skyrim OST in lossless for instance now sounds like I'm completely surrounded by instruments.

I have a pair of NOS Tung Sol 6080WA power tubes on the way and some other 12AU7 + 6SN7 input tubes to try out.

I have to say the EH 12AU7 are great though given these are not rare at all so can be bought cheap.


----------



## Demoninja

Just have to chime in and express my joy! I finally have a dead quiet Crack!!!! For the longest time I had buzzing and humming and crackles and all sorts of crappy noises I don't want to hear. I've rebuilt the amp 3 times, one of those times with a majority of new components. Turns out my build was probably perfectly fine the first time because purchasing a UPS and some new tubes solved all of those noises. Whew finally time to sit back and enjoy listening to this kit I've had for over 2 years now.


----------



## Jimmy24

HD 650 + Crack/Speedball one of the best combo's ever made!


----------



## attmci

Jimbo24 said:


> HD 650 + Crack/Speedball one of the best combo's ever made!



If you really like it, you may consider to upgrade the caps.


----------



## Jimmy24

trust me already have  my amp is pretty much full on hulk. Changed all caps, got the cree upgrade etc. Sounds exquisite!


----------



## Jimmy24

Btw have you guys seen what cshop87's selling on eBay? Beautiful, just beautiful.


----------



## attmci

Jimbo24 said:


> Btw have you guys seen what cshop87's selling on eBay? Beautiful, just beautiful.


It will be nice to build one by yourself.

What tubes are you using?


----------



## Jimmy24

I got a TS 5998 and Siemens 5814a. I had the CBS Hytron 5814a which was actually a fantastic tube. I think I like it better than the Siemens 5814a but I haven't looked to get one yet


----------



## attmci (Jan 5, 2018)

Jimbo24 said:


> I got a TS 5998 and Siemens 5814a. I had the CBS Hytron 5814a which was actually a fantastic tube. I think I like it better than the Siemens 5814a but I haven't looked to get one yet



The best 12au7 is Lorenz Ecc82 (long plate, very rare) and Amperex 7316 (rare). Followed by many other nice tubes like Mullard blackburn ECC82 (long plate), TS black glass, CBS Hytron 5814a (with the bent getter, black plate), Amperex CV 491,  Mullard CV4003, Telefunken ECC82.

(Don't use this guy's price as reference for any tube: old_guy_radiola )


----------



## Paladin79 (Jan 7, 2018)

Jimbo24 said:


> Btw have you guys seen what cshop87's selling on eBay? Beautiful, just beautiful.



Those are basic builds, no upgrades with a nice wiring job. It will be interesting to see if they sell since the kit on sale is what $275-$300 with speedball upgrade? Building the basic kit takes me about six hours, eight hours if I take my time so even at nine hours for the build that is ballpark $40 per hour. After my first build I got considerably faster so build time should decrease, the more you build. There is also the expense of spray paint and wood finishes. Not a bad venture if they sell, I suspect it will be a bit of a wait.  I left out Ebay fees and they are including shipping so that is probably an investment of $3,000 to make similar money so still not bad.


----------



## attmci

Paladin79 said:


> Those are basic builds, no upgrades with a nice wiring job. It will be interesting to see if they sell since the kit on sale is what $275-$300 with speedball upgrade? Building the basic kit takes me about six hours, eight hours if I take my time so even at nine hours for the build that is ballpark $40 per hour. After my first build I got considerably faster so build time should decrease, the more you build. There is also the expense of spray paint and wood finishes. Not a bad venture if they sell, I suspect it will be a bit of a wait.  I left out Ebay fees and they are including shipping so that is probably an investment of $3,000 to make similar money so still not bad.


Agreed.

How about these installations:

https://www.head-fi.org/threads/la-figaro-339.502306/page-144


----------



## Paladin79

Very nice work. I definitely want to try several new tube builds in the upcoming year as time allows.


----------



## Jimmy24

Paladin79 said:


> Those are basic builds, no upgrades with a nice wiring job. It will be interesting to see if they sell since the kit on sale is what $275-$300 with speedball upgrade? Building the basic kit takes me about six hours, eight hours if I take my time so even at nine hours for the build that is ballpark $40 per hour. After my first build I got considerably faster so build time should decrease, the more you build. There is also the expense of spray paint and wood finishes. Not a bad venture if they sell, I suspect it will be a bit of a wait.  I left out Ebay fees and they are including shipping so that is probably an investment of $3,000 to make similar money so still not bad.



Trust me I've built a few myself and considering that he also had to stain and finish the wood and chassis takes a long time. Look at the details on that angled wiring for those amps. I've tried doing something similar which was just too much work. He must have spent at least a few days building each one like that. I mean to do 10 of them, that's insane amount of work. I have also not seen anything quite as beautiful as them. Most have good stains but not great and the finishing is top notch as well.


----------



## Paladin79

I can only speak from experience and were I to do ten of the amps, it is easy enough to get the lengths and bends down to where you are doing the same steps to ten wires, or ten resistors or ten caps and things go quicker. Judging by the reflection in the cards it is a high gloss finish that appears to have been used on all boxes. Get the stains applied, spray all boxes at once and that step moves pretty fast as well. I apologize for thinking this way, I have done and currently do large production jobs. My amps are more complex, three copper plates, dual controls, dual vu meters but it is not as though I cannot do the simpler work. I did build one stock and combined two of the stock wooden cabinets so I have used the original materials extensively as well. I do a lot of project management and this person or persons are obviously experienced to keep wires at right angles to one another and to keep the consistency in the builds. I have seen plenty of the crack amps on ebay and some have Alps pots, walnut cabinets, selections of high end tubes, expensive capacitor changes and extremely good wiring and paint jobs. Even those sit for a while with prices not so much higher than the ten listed.


----------



## Demoninja

Those builds are absolutely beautiful but I think the asking price is way too much.  You lose the value proposition of the Crack and I feel like a majority of people who would consider purchasing a prebuilt Crack wouldn't dare touch the insides of the amp. At $650 you're nearing the price of amps that blow an unmodded BHC out of the water (in my opinion)/


----------



## bloodhawk

Demoninja said:


> Those builds are absolutely beautiful but I think the asking price is way too much.  You lose the value proposition of the Crack and I feel like a majority of people who would consider purchasing a prebuilt Crack wouldn't dare touch the insides of the amp. At $650 you're nearing the price of amps that blow an unmodded BHC out of the water (in my opinion)/



Very true. Which would be those other amps though?


----------



## Paladin79

There are other OTL amps on the market of course, some out of China. I have not heard them all so it is a little tough to compare apples to apples. One thing about it, the person or persons building those is doing it as a business venture and that is a lot different than someone taking the time over a weekend to build their own amp. Those builds are quite nice and then need to be. I talked about it as a business venture because I do electronics professionally so I looked at it as if I were to take on building ten of those amps.


There is a lot of pleasure in building such a thing yourself and putting your own personal touches in it. My own preferences differ from what is offered on Ebay and that probably holds true for most of the folks in here. This is one of my crack builds, quartered oak, copper, and brass.


----------



## Demoninja (Jan 7, 2018)

ViKiD(TM) said:


> Very true. Which would be those other amps though?



Cheating a bit by using some used prices but I'd say La Figarro 339 and Mjolnir 2 are both better purchases at that range.

What do you guys do with tubes that have ringing? I have a couple lying around that i don't listen to because of that problem.

Edit: added in Mjolnir 2 which I accidentally deleted before posting.


----------



## bloodhawk

Demoninja said:


> Cheating a bit by using some used prices but I'd say La Figarro 339 are both better purchases at that range.
> 
> What do you guys do with tubes that have ringing? I have a couple lying around that i don't listen to because of that problem.


Ah yeah that is a pretty good one. 

I personally haven't had Tube ringing on anything other than one Mullard 12AU7, which also for some weird reason went away after a few days. I would try using a foam/rubber feet maybe.


----------



## attmci

Demoninja said:


> Cheating a bit by using some used prices but I'd say La Figarro 339 and Mjolnir 2 are both better purchases at that range.
> 
> What do you guys do with tubes that have ringing? I have a couple lying around that i don't listen to because of that problem.
> 
> Edit: added in Mjolnir 2 which I accidentally deleted before posting.



Clean the pins with the DeoxIt. If that doesn't help, get rid of it and move on.


----------



## bloodhawk

Demoninja said:


> Cheating a bit by using some used prices but I'd say La Figarro 339 and Mjolnir 2 are both better purchases at that range.
> 
> What do you guys do with tubes that have ringing? I have a couple lying around that i don't listen to because of that problem.
> 
> Edit: added in Mjolnir 2 which I accidentally deleted before posting.


La Figarro sure, but not the Mjolnir 2. But that could just be me. I really dont like a neutral analytical signature.


----------



## Doc B.

Jimbo24 said:


> Btw have you guys seen what cshop87's selling on eBay? Beautiful, just beautiful.



It's usually considered good form to clarify whether or not you have any association with the seller when posting this kind of thing.


----------



## attmci (Jan 9, 2018)

Doc B. said:


> It's usually considered good form to clarify whether or not you have any association with the seller when posting this kind of thing.


Now I am pretty sure these amps are not assembled by the Bottlehead.


----------



## Doc B.

Your comment may be adding some confusion. Those are our kits. We did not assemble them. I don't know why anyone would assume that we did. 
None of that is my point. Generally accepted good netiquette is that someone clarifies when they post enthusiasm about something for sale whether they have any association with the seller or not. I was just suggesting that such a clarification might be appropriate here.


----------



## Paladin79 (Jan 9, 2018)

Nice builds but I assumed there was an association myself. Most folks are proud of their own builds, it is part of the experience.

I should clarify, an association between the seller and commentor seemed logical. Bottlehead just sells a very well documented kit.


----------



## deserat

Demoninja said:


> Cheating a bit by using some used prices but I'd say La Figarro 339 and Mjolnir 2 are both better purchases at that range.
> 
> What do you guys do with tubes that have ringing? I have a couple lying around that i don't listen to because of that problem.
> 
> Edit: added in Mjolnir 2 which I accidentally deleted before posting.



MJ2 isn't that much better. I have the MJ2 and the Crack + Speedball.  Crack I'd put somewhere between the Lyr2 and the MJ2 on most things, but the MJ2 is really is harsh and tubes don't help that much, Crack vs MJ2 at least for me is really a question of what you prefer. Ya loose some detail with Crack, but gain musicality. Neither amp will put you in the room with the performer, but I'd say the Crack gets closer.  Some of this will of course come down to what you are driving with the amp, can't run my Ethers off the Crack. My point is it's not as clear cut as suggested.


----------



## Quadfather

Who knows the model numbers for "big Russian" and "little Russian" tubes?  What are the best crack tubes for use with HD650?


----------



## FunyunBreath

Quadfather said:


> Who knows the model numbers for "big Russian" and "little Russian" tubes?  What are the best crack tubes for use with HD650?



There really is no "best", all the higher end tubes are a balance of trade-offs really. That being said, I prefer the Siemens Chrome Plate for the driver most of the time. And for power tubes I rotate between the 5998, Mullard 6080, and Tung Sol 6as7G

If you've heard the Valhalla 2 with your 650's, the SIemens + 5998 will give you a very close sound signature, with maybe a touch of added warmth.


----------



## Paladin79

I like some Russian 6as7g's I bought NOS, they are the larger tube of course. I do not have an amp in front of me but I am fairly certain that is the tube number. I used four of them in this configuration.


----------



## bloodhawk

Quadfather said:


> Who knows the model numbers for "big Russian" and "little Russian" tubes?  What are the best crack tubes for use with HD650?



My pair of choice is the Tung Sol 5998 + Mullard 12AU7 (Or Amperex Bugle Boy, Tungsgram E80CC , Amperex 7119 PQ -> Crack needs modifications to run the latter 2)


----------



## Paladin79

The question was about Russian tubes but I have run Tung Sol etc. and own a Valhalla 2, IMHO the Crack is warmer sounding with most any combination I have tried. The Valhalla is a little tough to discern from solid state or maybe I have not varied my tube rolling in it enough to approximate a Crack.


----------



## bloodhawk

Paladin79 said:


> The question was about Russian tubes but I have run Tung Sol etc. and own a Valhalla 2, IMHO the Crack is warmer sounding with most any combination I have tried. The Valhalla is a little tough to discern from solid state or maybe I have not varied my tube rolling in it enough to approximate a Crack.



You need to try the Tungsgram E80CC. It really livens up the signature. But the plate load resistors will need to be swapped for it work effectively.


----------



## buldogge

Quadfather said:


> Who knows the model numbers for "big Russian" and "little Russian" tubes?  What are the best crack tubes for use with HD650?



I answered your question in the other thread you posted in.

-Mark in St. Louis


----------



## Demoninja

deserat said:


> MJ2 isn't that much better. I have the MJ2 and the Crack + Speedball.  Crack I'd put somewhere between the Lyr2 and the MJ2 on most things, but the MJ2 is really is harsh and tubes don't help that much, Crack vs MJ2 at least for me is really a question of what you prefer. Ya loose some detail with Crack, but gain musicality. Neither amp will put you in the room with the performer, but I'd say the Crack gets closer.  Some of this will of course come down to what you are driving with the amp, can't run my Ethers off the Crack. My point is it's not as clear cut as suggested.



Just to clarify, my comment was in the context of spending $650 for a prebuilt Crack with speedball, no other mods involved. Given that price bracket I think the MJ2 offers a lot more for a majority of people. I agree it's mostly a matter of preference and I typically tend towards the more utilitarian choice.


----------



## Quadfather

buldogge said:


> I answered your question in the other thread you posted in.
> 
> -Mark in St. Louis



Thanks


----------



## DavidA

Paladin79 said:


> The question was about Russian tubes but I have run Tung Sol etc. and own a Valhalla 2, IMHO the Crack is warmer sounding with most any combination I have tried. The Valhalla is a little tough to discern from solid state or maybe I have not varied my tube rolling in it enough to approximate a Crack.


The Valhalla2 is a strange OTL amp, agree with you that its like a SS amp, rolling tubes has little or no effect on the sound from my limited time that I spent with rolling tubes in it.


----------



## Paladin79

I ended up using mine more as a preamp out into other amps including Crack amps.


----------



## attmci

ViKiD(TM) said:


> My pair of choice is the Tung Sol 5998 + Mullard 12AU7 (Or Amperex Bugle Boy, Tungsgram E80CC , Amperex 7119 PQ -> Crack needs modifications to run the latter 2)


You have to mod the Crack to use E80CC or 7119 (5687) tubes.

*Amperex 7316 Long Plates Foil Getter *is one of the best. But, hope you can find it.


----------



## bloodhawk

attmci said:


> You have to mod the Crack to use E80CC or 7119 (5687) tubes.
> 
> *Amperex 7316 Long Plates Foil Getter *is one of the best. But, hope you can find it.


Yeap -> https://imgur.com/a/Ax2VG

Yeah i was looking for one of those, but as you said, they are super hard to find for a decent price.


----------



## attmci

ViKiD(TM) said:


> Yeap -> https://imgur.com/a/Ax2VG
> 
> Yeah i was looking for one of those, but as you said, they are super hard to find for a decent price.


For that price, I will get a ECC33.


----------



## bloodhawk

attmci said:


> For that price, I will get a ECC33.


 Been debating getting a VT-231. Already have quite a few good 6SN7's. But lets see, now a days i usually swap around between the Mullar 12AU7/7119 PQ/Tungsgram E80CC. Sometimes even using the Telefunken 12AU7.


----------



## i luvmusic 2

Paladin79 said:


> I ended up using mine more as a preamp out into other amps including Crack amps.



Have you tried the CRACK as a PRE?I used my Crack as a Pre to drive my Kenwood Amp and a Sansui speaker nice pairing i would say.....


----------



## Paladin79

I have used a Crack as a preamp and even added outputs on two of them. I have several amps and amp/DACs with more arriving next week. They do work well in that function; I tend to experiment until I find an exceptional sound I am willing to share with others. My latest interest is balanced amps but I keep all those components separate.


----------



## bloodhawk

Paladin79 said:


> I have used a Crack as a preamp and even added outputs on two of them. I have several amps and amp/DACs with more arriving next week. They do work well in that function; I tend to experiment until I find an exceptional sound I am willing to share with others. My latest interest is balanced amps but I keep all those components separate.



Which would be your fav balanced diy amp ?


----------



## Paladin79 (Jan 13, 2018)

Unfortunately it is a tube amp I designed and built myself, class A, cathode follower, but I gave it away to a friend. I learned enough in the process to know what I want to build next. The Crack thread is probably not the best place to discuss such things. Currently I am doing an entire solid state balanced  set up but I am a week out in completing that. I generally build my own cables and modify the headphones to fit the design. It takes a couple weeks to tweak everything.

I am not aware of a lot of balanced DIY amps but I was thinking the Bottlehead Mainline might be one?  I have not built one so I cannot comment much about it but I did glance at them some time ago and I do believe they use a higher level of individual parts in the build and it is a company I would trust to provide great products. If there is a current thread in here talking about balanced amps send me a link and we could go there to discuss such things.


----------



## Quadfather

I cleaned the tube contacts, both male and female ends, on my bottlehead crack and it seems to sound even better. I use Deoxit. Am I imagining things?


----------



## deserat

Quadfather said:


> I cleaned the tube contacts, both male and female ends, on my bottlehead crack and it seems to sound even better. I use Deoxit. Am I imagining things?



I've heard a difference when applied to NOS tubes. But I'm guessing it depends on how corroded or dirty ( finger oils etc )  the pins are. Once cleaned the first time repeat cleanings have never done  any good.


----------



## Demoninja

So I'm getting ready to mod my Bottlehead crack and was getting my shopping list ready. I've decided on adding a choke, replacing the 2 output caps with film caps, modding the power supply with cree diodes. Anyone got suggestions on what to purchase to mount the choke? I think I've got the film cap mounting and the PCB board down.


----------



## atomicbob

Demoninja said:


> So I'm getting ready to mod my Bottlehead crack and was getting my shopping list ready. I've decided on adding a choke, replacing the 2 output caps with film caps, modding the power supply with cree diodes. Anyone got suggestions on what to purchase to mount the choke? I think I've got the film cap mounting and the PCB board down.


https://www.digikey.com/product-detail/en/2250-832-AL/1772-1226-ND/


----------



## bloodhawk

Demoninja said:


> So I'm getting ready to mod my Bottlehead crack and was getting my shopping list ready. I've decided on adding a choke, replacing the 2 output caps with film caps, modding the power supply with cree diodes. Anyone got suggestions on what to purchase to mount the choke? I think I've got the film cap mounting and the PCB board down.



I used the spacers from this -https://www.amazon.com/gp/product/B018C19KJ0/ref=oh_aui_detailpage_o08_s00?ie=UTF8&psc=1

Wrapped them in electrical tape for good measure.


----------



## Demoninja

Thanks for the suggestions, went with the set from Amazon. Just waiting for all the parts to come in and I can get started modding.


----------



## Quadfather

I am getting a low-level ringing in the Left Channel. When I tap on the tubes it goes away for a while. Does this sound like one of the tubes?


----------



## FunyunBreath (Feb 22, 2018)

Quadfather said:


> I am getting a low-level ringing in the Left Channel. When I tap on the tubes it goes away for a while. Does this sound like one of the tubes?



Yeah that sounds like microphonics in either the driver or power tube. If the tube is fairly new then sometimes that can go away with burn in. Try leaving the amp on for 3-4 days straight to give the tube cathodes time to form.


----------



## Quadfather (Feb 22, 2018)

FunyunBreath said:


> Yeah that sounds like microphonics in either the driver or power tube. If the tube is fairly new then sometimes that can go away with burn in. Try leaving the amp on for 3-4 days straight to give the tube cathodes time to form.



There have been a few times that my Crack shuts itself off, but it's rare.  When I tap on the power tube the ringing will temporarily go away. Sometimes that happens with the smaller tube as well.  Damn, still sounds great. I have an RCA CRC 6080 and an RCA 12AU7A


----------



## bloodhawk

Quadfather said:


> There have been a few times that my Crack shuts itself off, but it's rare.  When I tap on the power tube the ringing will temporarily go away. Sometimes that happens with the smaller tube as well.


That is not normal. I would check the wiring pronto. Along with the solder joints, could be a cold joint somewhere.


----------



## Quadfather (Feb 22, 2018)

bloodhawk said:


> That is not normal. I would check the wiring pronto. Along with the solder joints, could be a cold joint somewhere.



What kind of solder should I use?  I use tin- lead 60/40 rosin core solder to fix a loose wire but everything else looked good.  And said it was for electronics.


----------



## bloodhawk (Feb 22, 2018)

Quadfather said:


> What kind of solder should I use?


Any 60/40 rosin core leaded solder is fine. I personally prefer Kester. Though people would love to sell you on Cardas / Audio grade solder etc... But that is a totally different can of worms.

Main thing with soldering though, is to use flux. Apply flux, heat up joints while feeding solder in. With the properly heated joints, the solder will easily flow across.


----------



## attmci

Quadfather said:


> What kind of solder should I use?  I use tin- lead 60/40 rosin core solder to fix a loose wire but everything else looked good.  And said it was for electronics.


All of the joints.

Those two tubes can be obtained for $10 each, so no big deal.


----------



## Paladin79

Most solder is hollow core and already contains rosin flux. On occasion extra flux is needed to clean new metal.


----------



## Quadfather

@bloodhawk,  is it normal for one side of the tube to be so much brighter than the other?


----------



## bloodhawk

Quadfather said:


> @bloodhawk,  is it normal for one side of the tube to be so much brighter than the other?



Not really.
But unless your voltages are off , or you are having channel imbalance , i think you should be ok.


----------



## Quadfather (Feb 22, 2018)

bloodhawk said:


> Not really.
> But unless your voltages are off , or you are having channel imbalance , i think you should be ok.



The channel balance is fine, and the amp sounds drop dead gorgeous. I am thinking maybe the tube imbalance in brightness is a sign that it's going bad which may be part of the problem


----------



## bloodhawk

Quadfather said:


> The channel balance is fine, and the amp sounds drop dead gorgeous. I am thinking maybe the tube imbalance in brightness is a sign that it's going bad which may be part of the problem



Definitely could be, some tubes start becoming micro-phonic as they are about to go bad.


----------



## hawkwindx (Feb 22, 2018)

What song or songs makes your Crack shine?

It’s a question that’s been asked a lot, but it’s nice to discover something new. Something I recently discovered is “Sinatra At The Sands”.


----------



## Quadfather

hawkwindx said:


> What song or songs makes your Crack shine?
> 
> It’s a question that’s been asked a lot, but it’s nice to discover something new. Something I recently discovered is “Sinatra At The Sands”.



Any high resolution Rush.  Solar Wind, Mix it Up, Chick Correa Trio, among others.  I will try to add them as I listen to them. People talk about the hd650s being so warm, but I think they are really quite a neutral on the Bottlehead Crack.


----------



## Paladin79 (Feb 23, 2018)

I mostly listen to binaural plus recordings, people like Amber Rubarth and Noah Wall but one of my favorite standard recordings is Warren Zevon's Nighttime at the Switching Yard and Brubeck's Time Out album.  Another binaural favorite is Rebecca Pigeon's Spanish Harlem.  I recently discovered Tidal so through there I often play The Beast in Me by Nick Lowe and Lake Street Dive's I want you Back.

I generally have two amps hooked up with different headphones, the Crack with HD 650's and a balanced setup using two solid state amps with another set of headphones, the warmth of the Crack always draws me back and I spend more time listening to it.


----------



## Doc B.

Guys, you have this backwards. If you tap on the tube and it rings, that is microphonics. If the tube starts to sing without any mechanical impulse like tapping - and tapping it stops the singing - that is not microphonics, it is an oscillation due to something electrical. First thing to try is thoroughly cleaning the tube pins.


----------



## hawkwindx (Feb 23, 2018)

Thanks for clearing that up, Doc B.

I bought a tube with a broken center pin, the plastic part, that sounds OK, but very microphonic.

Joni Mitchell's Travelogue and Peter Gabriel's New Blood is worth checking out.


----------



## Quadfather

Doc B. said:


> Guys, you have this backwards. If you tap on the tube and it rings, that is microphonics. If the tube starts to sing without any mechanical impulse like tapping - and tapping it stops the singing - that is not microphonics, it is an oscillation due to something electrical. First thing to try is thoroughly cleaning the tube pins.



Could it also be a bad tube?


----------



## Doc B.

Did you try what I suggested?


----------



## Quadfather (Feb 24, 2018)

Doc B. said:


> Did you try what I suggested?



I cleaned the connectors and the power tube area, but I don't know how to get into the other one to clean it. The holes are so small


----------



## Doc B.

I'm saying clean the pins on the tube. The tube socket contacts are probably fine. Sometimes you can clear up oscillation by simply inserting and removing the tube from the socket a few times, which scrapes the pins a little bit. But I usually clean them with DeOxit or even a little fine sandpaper. To really do them up you can chuck up half a Q-tip in a Dremel tool and buff the pins with some metal polish. That's what I do with critical stuff like recording gear.


----------



## Quadfather

Doc B. said:


> I'm saying clean the pins on the tube. The tube socket contacts are probably fine. Sometimes you can clear up oscillation by simply inserting and removing the tube from the socket a few times, which scrapes the pins a little bit. But I usually clean them with DeOxit or even a little fine sandpaper. To really do them up you can chuck up half a Q-tip in a Dremel tool and buff the pins with some metal polish. That's what I do with critical stuff like recording gear.



The sockets for the, I forget if it's called input or output tube, were filthy.


----------



## Quadfather

Okay, I cleaned as best as I could. It seems like ringing is much diminished.  I am assuming tubes always have a little bit of background noise.


----------



## Quadfather

@Doc B. , Can a power cable cause oscillation?  Seems much better since cleaning.


----------



## Quadfather

Day 2 since cleaning the pins and sockets.  Any ringing is barely audible on pause.


----------



## Quadfather

Can noisy tubes cause low level ringing?


----------



## Quadfather (Feb 25, 2018)

On my RCA 12AU7A, there is a dark circle inside the glass surrounded with a lighter colored charcoal/white color.  Could this have anything to do with low-level ring?

*****UPDATE*****  I cleaned the pins with wet/dry sandpaper, 1500 fine grit until they shined and it seems like any ringing is probably just my ears.  Actually, now there isn't any ringing. I was also able to get a mini cleaning pick into the sockets for the output tube and they were pure black dirty.


----------



## Quadfather (Feb 25, 2018)

Do most people on here plug their Bottlehead Cracks into a surge protector, or directly into the outlet?


----------



## Quadfather

Quadfather said:


> Do most people on here plug their Bottlehead Cracks into a surge protector, or directly into the outlet?



Okay, I plugged mine into a surge protector and thoroughly cleaned the pins.  Now I get a little ringing when the amp first starts up, but after it warms up it's dead silent.


----------



## Quadfather (Feb 25, 2018)

HELP!  When I order for my Crack, do I order high-gain for the tube, or just low microphonics and balanced triodes?  Everybody on this thread is sure to know I'm a newbie.  Also, is a Tung Sol 5998, with a Mullard CV4003 a good tube combination?   I am loving the sound now, but I want to try to roll.


----------



## Paladin79

I have used the tung sol and other Mullards and was pleased with the results.

it is good to have some extra tubes so you can swap tubes that become suspect. In my experience the kits come with new 6080's but I do not recall any choices other than you get quality working tubes.


----------



## Ad-Astra

if anyone is selling one, pm me


----------



## Quadfather (Mar 7, 2018)

I purchased an RCA 12AU7A and an RCA 6080 from tubedepot.com, and now there is absolutely zero ringing noise or any other kind of noise. It actually sounds quite good.  Eventually, I want a Mullard CV4003 and a Tung Sol 5998.


----------



## Paladin79

Ad-Astra said:


> if anyone is selling one, pm me



Lots of them on Ebay by the same seller but the price is fairly high in the event no one contacts you. 

Usually when I see ad astra it is followed by per aspera, to the stars through difficulties.


----------



## Paladin79

Quadfather said:


> I purchased an RCA 12AU7A and an RCA 6080 from tubedepot.com, and now there is absolutely zero ringing noise or any other kind of noise. It actually sounds quite good.  Eventually, I want a Mullard CV4003 and a Tung Sol 5998.



It never hurts to have extras and it is a quick and easy way to diagnose issues. I have several older RCA tubes I like pretty well, I even worked for them once upon a time.


----------



## Quadfather

Am I the only person who enjoys the RCA 6080 along with the RCA 12AU7A?


----------



## bloodhawk

Quadfather said:


> Am I the only person who enjoys the RCA 6080 along with the RCA 12AU7A?



Im more a Mullard/Telefunken/CBS Hytron 12AU7 Fan , otherwise i use the Tungsgram E80CC or the Amperex 7119PQ + TungSol 7236 or 5998.(latter one most of the time)


----------



## Quadfather

bloodhawk said:


> Im more a Mullard/Telefunken/CBS Hytron 12AU7 Fan , otherwise i use the Tungsgram E80CC or the Amperex 7119PQ + TungSol 7236 or 5998.(latter one most of the time)



I am just beginning to experiment with tubes on somewhat limited funds as I'm trying to save for a Sony NW-WM1Z...


----------



## attmci (Mar 7, 2018)

Quadfather said:


> I purchased an RCA 12AU7A and an RCA 6080 from tubedepot.com, and now there is absolutely zero ringing noise or any other kind of noise. It actually sounds quite good.  Eventually, I want a Mullard CV4003 and a Tung Sol 5998.


5998 are good tubes to invest in, for sq. I have a bunch.

CV4003, they are good for resell. I have one and it stays in the box all the time.

You can use 6SN7 etc. with an adapter.

BTW, I _know_ tubedepot.com made >$1000s purchase (tube adapter etc.) from China quite often.


----------



## buldogge

There are Tung Sol 7236s on eBay for $35...I've got one of the paired with a Tung Sol Mouse Ears 6SN7, and it IMHO is quite a nice combo.

-Mark in St. Louis


----------



## LikeABell

I'm currently rocking the RCA 12AU7 and GEC 6080. Good bass and nice top extension. You can find the RCA cleartops labelled as "Conn" for cheap.
Another great input tube is the RFT, lovely soundstage and lots of details.


----------



## Paladin79

I have been pleased with the results of this RCA tube, no reason to get a matched pair but this is something I watch for on EBAY.

https://www.ebay.com/itm/NIB-NOS-Ma...356329?hash=item4d6edb6ee9:g:h-cAAOSw7GRZL3SB

I may have called them 5998's earlier but they are 6AS7G's. The Russian tubes I like are this series. I have bought seven or eight and all have been NOS and in excellent condition. 

https://www.ebay.com/itm/2-x-6N13S-...600030&hash=item5b434bfb39:g:0wkAAOSweLBabo~U


----------



## Quadfather (Mar 8, 2018)

Paladin79 said:


> I have been pleased with the results of this RCA tube, no reason to get a matched pair but this is something I watch for on EBAY.
> 
> https://www.ebay.com/itm/NIB-NOS-Ma...356329?hash=item4d6edb6ee9:g:h-cAAOSw7GRZL3SB
> 
> ...



Believe it or not an RCA 6080 and an RCA 12AU7A is rocking this thing nicely.  With regard to the Sennheiser HD 650 headphones, what veil?


----------



## Quadfather

I am still marveling at the dead silent, black background after replacing the tubes in my Bottlehead Crack amplifier!


----------



## Paladin79

Honestly I do not find a lot of difference between 6080's or comparable tubes compared to the 12AU7A's so I just usually say something like "they work well". Audio is pretty subjective and if you are happy with a certain set of tubes that is wonderful. I have gone as far as to buy Tung Sol, Chatham, Mullard and have tested in two identical Crack amps sitting next to each other (I did both builds). I used a switchbox and the same set of headphones so there were few variables. I was hard pressed to find enough difference to justify spending $200 for a tube compared to the $10 for a new 6080 or 6AS7G. YMMV

 You get good original tubes with the kit and in buying a lot of used tubes and supposed new old stock, occasionally I would get some that did not perform as well as the originals but that is the nature of tubes, they only last so long.


----------



## Quadfather

Paladin79 said:


> Honestly I do not find a lot of difference between 6080's or comparable tubes compared to the 12AU7A's so I just usually say something like "they work well". Audio is pretty subjective and if you are happy with a certain set of tubes that is wonderful. I have gone as far as to buy Tung Sol, Chatham, Mullard and have tested in two identical Crack amps sitting next to each other (I did both builds). I used a switchbox and the same set of headphones so there were few variables. I was hard pressed to find enough difference to justify spending $200 for a tube compared to the $10 for a new 6080 or 6AS7G. YMMV
> 
> You get good original tubes with the kit and in buying a lot of used tubes and supposed new old stock, occasionally I would get some that did not perform as well as the originals but that is the nature of tubes, they only last so long.



I finally got the ringing to stop, so I'm afraid to even touch the tubes with my hands now. LOL


----------



## Paladin79

I tend to hold onto one set as a baseline, new tubes that I have received with a kit or have purchased as new. Then I swap tubes till I find a pair I like but if I ever wonder about tubes, I can go back to the originals and see if conditions change. My situation is different and I have built a few Cracks and similar amps so it is nothing for me to have a dozen or more tubes laying around. Things happen and you can get a decent 6080 for $10 or so, I have not bought 12au7's for a while but new stock is probably less than $10.


----------



## attmci (Mar 10, 2018)

Paladin79 said:


> Honestly I do not find a lot of difference between 6080's or comparable tubes compared to the 12AU7A's so I just usually say something like "they work well". Audio is pretty subjective and if you are happy with a certain set of tubes that is wonderful. I have gone as far as to buy Tung Sol, Chatham, Mullard and have tested in two identical Crack amps sitting next to each other (I did both builds). I used a switchbox and the same set of headphones so there were few variables. I was hard pressed to find enough difference to justify spending $200 for a tube compared to the $10 for a new 6080 or 6AS7G. YMMV
> 
> 
> 
> You get good original tubes with the kit and in buying a lot of used tubes and supposed new old stock, occasionally I would get some that did not perform as well as the originals but that is the nature of tubes, they only last so long.





Paladin79 said:


> Honestly I do not find a lot of difference between 6080's or comparable tubes compared to the 12AU7A's so I just usually say something like "they work well". Audio is pretty subjective and if you are happy with a certain set of tubes that is wonderful. I have gone as far as to buy Tung Sol, Chatham, Mullard and have tested in two identical Crack amps sitting next to each other (I did both builds). I used a switchbox and the same set of headphones so there were few variables. I was hard pressed to find enough difference to justify spending $200 for a tube compared to the $10 for a new 6080 or 6AS7G. YMMV
> 
> You get good original tubes with the kit and in buying a lot of used tubes and supposed new old stock, occasionally I would get some that did not perform as well as the originals but that is the nature of tubes, they only last so long.


Toooo bad, my friend. I hope you will find a pair of output and driver tubes meet your needs.

https://bottlehead.com/smf/index.php?topic=663.0


----------



## Paladin79

I have many I like, some more than others. I just tend to notice more difference changing 12Au7's.


----------



## attmci

I see. Bendix 6080wb is a good choice for the Crack.


----------



## Paladin79 (Mar 11, 2018)

I will try to check those out sometime. I just found some on Ebay in the $200 range, I would hope they sound better and yours is certainly an opinion I would trust.

Soon i will be doing some more testing using local grad students from a very good school of music, I have RCA, Tung Sol, Chatham, Russian made etc. I am always curious what those with younger ears might find to their liking or if I can even get consistent results. I will then try the same thing with different 12au7 equivalents but I need to stock up on more of those before I do testing. It is just to satisfy my sense of curiosity but if people are just as pleased with a $10 6080, why invest in a $100-$200 tube? It is a given that buying old or used tubes can be tricky. Are you really getting new old stock or even tubes in decent condition? I sold my tube tester years ago but I have been meaning to reinvest in a good one, at least that way I am more likely to compare apples to apples. In a few years I shall retire and probably do a bit of consulting but I may consider building custom headphone cables, or selling tubes that I have tested and certified. I will probably say no more than here is a Tung Sol 5998, here are the test results. Cables are even trickier, I would talk about materials and construction techniques but it is always up to the individual to say 7 N OCC copper sounds better than high strand litz or a specific brand of OFC. I would never do that as a seller since some things are pretty subjective. On tubes I guess I could say, this particular brand or type is a favorite of my testers, or folks whose opinions I trust YMMV. As tubes become more scarce, their values will no doubt rise, I can think of worse investments lol.


----------



## attmci

Paladin79 said:


> I will try to check those out sometime. I just found some on Ebay in the $200 range, I would hope they sound better and yours is certainly an opinion I would trust.
> 
> Soon i will be doing some more testing using local grad students from a very good school of music, I have RCA, Tung Sol, Chatham, Russian made etc. I am always curious what those with younger ears might find to their liking or if I can even get consistent results. I will then try the same thing with different 12au7 equivalents but I need to stock up on more of those before I do testing. It is just to satisfy my sense of curiosity but if people are just as pleased with a $10 6080, why invest in a $100-$200 tube? It is a given that buying old or used tubes can be tricky. Are you really getting new old stock or even tubes in decent condition? I sold my tube tester years ago but I have been meaning to reinvest in a good one, at least that way I am more likely to compare apples to apples. In a few years I shall retire and probably do a bit of consulting but I may consider building custom headphone cables, or selling tubes that I have tested and certified. I will probably say no more than here is a Tung Sol 5998, here are the test results. Cables are even trickier, I would talk about materials and construction techniques but it is always up to the individual to say 7 N OCC copper sounds better than high strand litz or a specific brand of OFC. I would never do that as a seller since some things are pretty subjective. On tubes I guess I could say, this particular brand or type is a favorite of my testers, or folks whose opinions I trust YMMV. As tubes become more scarce, their values will no doubt rise, I can think of worse investments lol.


Nope, it should cost similar to a 5998. Check the eBay price history for reference.


----------



## Paladin79

Cool I will look around more when time allows. I just looked through the first page of listings, and there was an auction that may be more realistic.


----------



## attmci

Paladin79 said:


> Cool I will look around more when time allows. I just looked through the first page of listings, and there was an auction that may be more realistic.


You can set an alert on ebay.


----------



## Paladin79

I know. I have used EBay since it’s inception and a similar company prior to them that lacked their foresight. Some of the higher priced tubes may not sell just like the listing for Crack amps at $650, they may be there for quite a while lol. An item is only worth what a person is willing to pay for it.


----------



## attmci

Paladin79 said:


> I know. I have used EBay since it’s inception and a similar company prior to them that lacked their foresight. Some of the higher priced tubes may not sell just like the listing for Crack amps at $650, they may be there for quite a while lol. An item is only worth what a person is willing to pay for it.


There are other good amp kits available for DIY.


----------



## Paladin79

I did Dynaco years ago but have only dealt with Bottlehead recently as well as one I helped design.
 I am running out of space for amps, computers, speakers, headphones etc. My shop is filled with test equipment, tools, and components.


----------



## attmci

Paladin79 said:


> I will try to check those out sometime. I just found some on Ebay in the $200 range, I would hope they sound better and yours is certainly an opinion I would trust.
> 
> Soon i will be doing some more testing using local grad students from a very good school of music, I have RCA, Tung Sol, Chatham, Russian made etc. I am always curious what those with younger ears might find to their liking or if I can even get consistent results. I will then try the same thing with different 12au7 equivalents but I need to stock up on more of those before I do testing. It is just to satisfy my sense of curiosity but if people are just as pleased with a $10 6080, why invest in a $100-$200 tube? It is a given that buying old or used tubes can be tricky. Are you really getting new old stock or even tubes in decent condition? I sold my tube tester years ago but I have been meaning to reinvest in a good one, at least that way I am more likely to compare apples to apples. In a few years I shall retire and probably do a bit of consulting but I may consider building custom headphone cables, or selling tubes that I have tested and certified. I will probably say no more than here is a Tung Sol 5998, here are the test results. Cables are even trickier, I would talk about materials and construction techniques but it is always up to the individual to say 7 N OCC copper sounds better than high strand litz or a specific brand of OFC. I would never do that as a seller since some things are pretty subjective. On tubes I guess I could say, this particular brand or type is a favorite of my testers, or folks whose opinions I trust YMMV. As tubes become more scarce, their values will no doubt rise, I can think of worse investments lol.


An interesting test. However, ....


----------



## Paladin79

As one gets older, I read that it is fairly normal to lose a one octave range, high frequencies. I can no longer hear 15,750 hertz or above so I try to remain objective about sound and garner other opinions. There are obviously tubes I like more than others but I often wonder if specific used tubes might be at their best when received.


----------



## Allanmarcus

can anyone post what parts are needed for the rectifier cree/Schottky diodes needs for the mod? The board, I think is this one:
http://www.partsconnexion.com/product26996.html

but what about the diodes?


----------



## bloodhawk

Allanmarcus said:


> can anyone post what parts are needed for the rectifier cree/Schottky diodes needs for the mod? The board, I think is this one:
> http://www.partsconnexion.com/product26996.html
> 
> but what about the diodes?



https://www.mouser.com/ProductDetail/941-CSD01060A


----------



## Allanmarcus

bloodhawk said:


> https://www.mouser.com/ProductDetail/941-CSD01060A



Thanks! Any idea about the Schottky?


----------



## bloodhawk

Allanmarcus said:


> Thanks! Any idea about the Schottky?



That is a Schottky Diode. Which is a type and not a brand


----------



## Paladin79 (Mar 19, 2018)

Cree brand. I have several in my shop but not Cree. Barrier diode.


----------



## Allanmarcus

bloodhawk said:


> That is a Schottky Diode. Which is a type and not a brand


Doh! I though Schottky was a brand, not a type. Research time.

Thanks.


----------



## Paladin79 (Mar 19, 2018)

Walter Schottky was the inventor. Names like Volta, Faraday, Galvani, were attached to invention.

For some fun research look up Giovanni Aldini, nephew of Galvani. His experiments with electricity on frogs are thought to be the basis of the first science fiction novel, Frankenstein by Mary Shelley.


----------



## Dababy

I have found that the Crack is very sensitive to microphonic, almost not matter what tube you put in. Anyone have any ideas on chassis modifications to make it more stable and isolate more vibrations?


----------



## Allanmarcus

Dababy said:


> I have found that the Crack is very sensitive to microphonic, almost not matter what tube you put in. Anyone have any ideas on chassis modifications to make it more stable and isolate more vibrations?


Yep. I had the same issue. Here's how I solved it.

First, I get a few of these any vibration pads:
https://www.supplyhouse.com/sh/control/search/~SEARCH_STRING=anti vibration

I got the some of the blue ones and some of the cork ones. They are so darned cheap, I got a nice variety for different purposes. Some times I use them under speakers to protect the surface. Sometimes I use them to increase ventilation under a component.

For the crack I did this. I use four 2" square pads under a 5 pound granite cutting board ($11), then 4 more under the crack. The heavier surface between the crack and the table seems to help stabilize the crack.

I would start with the anti-vibration pads, and if you need more isolation, add a heavy surf between the crack and the table, with anti vibration pads in between. it's a very inexpensive solution.


----------



## Dababy

This does look like a very neat solution! I found that my EC ZDS with triangular rubber feet isolates vibration very well. I wonder how rubber spike would work under the granite....


----------



## Allanmarcus (Mar 25, 2018)

Dababy said:


> I wonder how rubber spike would work under the granite....



There are some examples of that on Esty. There are also lots of spikes and feet on Amazon (probably on AliExpress too). This would not be hard to make:

https://www.etsy.com/listing/268521224/audiophile-walnut-isolation-platform

Just some nicely stained, thick hard wood and some feet like these: https://smile.amazon.com/gp/product/B077SVS33N
Add more weight with the granite cutting board.

If you google search for "The Tube Anti-Vibration/isolation Discussion" you will find a thread I started on a another site on this topic. There are some good ideas there too.

Also, herbies makes some good stuff that isn't too expensive
http://herbiesaudiolab.net/compfeet.htm and http://herbiesaudiolab.net/misc.htm and http://herbiesaudiolab.net/softdots.htm
They also have some well regard anti-vibration stuff for the tubes too. http://herbiesaudiolab.net/tube.htm
Might even be helpful, though I have not tried it, to put weight on the crack itself. Any herbies has some "stabilizers" specifically for that, but they are pricey http://herbiesaudiolab.net/stable.htm
.
The trick is to get some weight to stabilize it.

I would try the anti vibration pads first.


----------



## Maxhawk

In my opinion, a properly functioning tube should not be microphonic. The 12AU7 input tube contains all the gain so it will be more susceptible, but there's nothing about the Cracks's topology that makes it more sensitive to microphonics. I have probably a dozen input tubes and maybe 1-2 of them are microphonic.


----------



## Paladin79 (Mar 25, 2018)

I happened to notice dampers for various sized tubes the other day in the event a tube is slightly microphonic.

https://www.ebay.com/itm/10Pcs-19mm...12AU7-12AT7-EL84-ECC88-6F2-/263366770809pers-

I have no idea if these work on tubes.

Personally I have no problems with this issue, the three plates I incorporated in my crack weigh in at three pounds and I used one inch thick oak for an enlarged cabinet. Weight alone probably helps mine a bit. 

To quote Allan...
The trick is to get some weight to stabilize it.

Mine is very stable, but not your normal Crack build.


----------



## Paladin79 (Mar 25, 2018)

Maxhawk said:


> In my opinion, a properly functioning tube should not be microphonic. The 12AU7 input tube contains all the gain so it will be more susceptible, but there's nothing about the Cracks's topology that makes it more sensitive to microphonics. I have probably a dozen input tubes and maybe 1-2 of them are microphonic.



I do agree with this statement, if you look at the other components used, the wire etc., there is very little in the design that can cause issues. There is some thing called a flag pole effect, if you have a tube that is slightly microphonic sitting on the cabinet I can imagine the microphonics being made evident with a slight cabinet shake.

I had not even purchased a crack, I glanced at a photo of the parts in the kit and I knew immediately I did not want to use the top plate. I went so far as to ask the dimensions and order an 1/8 inch copper plate before I even received the kit. I also incorporated other changes, a larger cabinet to allow for more expansion, dual volume controls, etc.  I believe Allan was kind enough to tell me it was a 6x10 inch top plate and I went from that.

I did use the aluminum plate on another build but only after I added a layer of carbon fiber and double the basic cabinet size, two more plates and 16 layers of laquer so it has some extra weight as well, and little vibration.

I should also mention, and this is more of a personal thing, but I did not like the idea of reaching around the tubes on the top plate to turn the amp on or plug in a cable, or plug in the quarter inch headphone connector. All inputs on mine are on the back, controls are on the front, and my headphone jack is on the side in one inch oak. I do little to add any vibration even if it is just adjusting the separate left and right volume controls.


----------



## Allanmarcus

Maxhawk said:


> In my opinion, a properly functioning tube should not be microphonic. The 12AU7 input tube contains all the gain so it will be more susceptible, but there's nothing about the Cracks's topology that makes it more sensitive to microphonics. I have probably a dozen input tubes and maybe 1-2 of them are microphonic.



I think the issue is with external vibrations, like say banging on a keyboard or walking around near the table where the Crack sits. I forgot that I could not keep the Crack on my desk as I hit the keys on the keyboard pretty hard. I keep the crack on a table next to my desk.



Paladin79 said:


> I should also mention, and this is more of a personal thing, but I did not like the idea of reaching around the tubes on the top plate to turn the amp on or plug in a cable, or plug in the quarter inch headphone connector. All inputs on mine are on the back, controls are on the front, and my headphone jack is on the side in one inch oak. I do little to add any vibration even if it is just adjusting the separate left and right volume controls.



The way I, and I think most others, orient the crack is to have the volume and jack on the front and the inputs and power on the back. While the input tube is a little close to the volume and jack, I wouldn't say I have to reach around anything to use volume, jack, or power.


----------



## Paladin79 (Mar 26, 2018)

I know the positions and as I said, it is a personal thing just like preferring a separate volume control for each channel. I would be reaching up there twice as much and I would  need to put the second control somewhere. I did what felt right for me. Also I did build a stock crack amp and used it to compare to one I began modifying,  I wanted to be absolutely sure that none of my changes affected overall sound. After that I pretty well knew the build and went on to modify a few of them.

I did put a blade switch on top in another build but it just controls magic eye tubes and aesthetically it is not meant to be mounted vertically. This is the only photo I have handy but the white blade switch is on the bottom left amp.

I envisioned my build before receiving the kit but that is just the way I think. My third build required some thought but I designed my own circuits. I should not even call this one a Crack amp, I just used a few left over parts from previous builds. It has 8 tubes, not the standard two.


----------



## chimney189

Good day everyone,
I recently purchased a BH Crack w/SB upgrade.
I'm currently using Tung Sol 7236 and Telefunken 12AU7.  The sound is a great balance between warmth and clarity, but I'm missing bass slam and punchiness (the bass slam seems near non-existent).

I've been looking for tubes that might help the situation out: https://www.ebay.com/itm/2-MULLARD-...017926&hash=item33e634c724:g:BlIAAOSwxyJav8fc

Has anyone had experience with these tubes?
Impressions?
Thanks!


----------



## FunyunBreath

chimney189 said:


> Good day everyone,
> I recently purchased a BH Crack w/SB upgrade.
> I'm currently using Tung Sol 7236 and Telefunken 12AU7.  The sound is a great balance between warmth and clarity, but I'm missing bass slam and punchiness (the bass slam seems near non-existent).
> 
> ...



The tubes you linked to are 6DJ8 and are not compatible with the Crack at all.

From my experience, the 7236 is the culprit here if you're looking for more bass slam. The 7236 is a very linear sounding tube with fast, well controlled bass, but it's flaw is that the bass lacks depth and slam.

I would look at a Tung Sol 6as7G to replace the 7236. And if you like that sound and want a more expensive variant with better sound, look at the Tung Sol 5998.

FWIW I've rolled almost all the higher-end tubes in my crack and my favorite combination is the Siemens Chrome Plate 12au7 + Tung Sol 5998


----------



## chimney189

attmci said:


> Bendix 6080wb





FunyunBreath said:


> The tubes you linked to are 6DJ8 and are not compatible with the Crack at all.
> 
> From my experience, the 7236 is the culprit here if you're looking for more bass slam. The 7236 is a very linear sounding tube with fast, well controlled bass, but it's flaw is that the bass lacks depth and slam.
> 
> ...



Thanks for your quick reply, much appreciated!
How does the overall sound signature sound with your favorite combination? 
I was also looking at the 7316 ECC186 Amperex?  Any impressions with that one?


----------



## chimney189

I also am realizing that the 5998 is a bit too expensive at the moment, are there cheaper alternatives that offer similar sound?


----------



## FunyunBreath

chimney189 said:


> Thanks for your quick reply, much appreciated!
> How does the overall sound signature sound with your favorite combination?
> I was also looking at the 7316 ECC186 Amperex?  Any impressions with that one?



No problem!

Siemens + 5998 is just a great combo with the HD800S. Holographic imaging, wide soundstage, fantastic mids, no sibilance, neutral but with deep bass. I rarely roll any other tubes in my crack at this point if that tells you anything 

The Amperex 7316 (mine is a Beckman labeled tube, short plate with halo getter) is my second favorite tube  However, 7316 have gotten insane in terms of price and I really don't think they are worth the money. I prefer the Siemens Chrome plate anyways, and they can be found for around $50 easily.

Another great tube to look at that is very reasonably priced is the Sylvania 5814A w/ 3 mica. They have a gorgeous midrange that really makes vocals shine.


----------



## FunyunBreath

chimney189 said:


> I also am realizing that the 5998 is a bit too expensive at the moment, are there cheaper alternatives that offer similar sound?



The Tung Sol 6as7G is basically a 5998 but with a bit less detail. I ordered mine from vacuumtubes.net for $20 a few months back


----------



## chimney189

So, this is what I've found:
https://www.tubedepot.com/products/6as7g-6520
&
https://www.ebay.com/itm/2-Siemens-...epid=0&hash=item239b4f15d0:g:dpAAAOSwKRdamg1Z


----------



## chimney189

Would these be correct?

EDIT:  I apologize for the back-and-forth as this would probably be handled better in private messages.


----------



## Paladin79 (Apr 3, 2018)

I like some of the 6as7g tubes, there are plenty of NOS Russian tubes but when you can trust the seller. I like the RCA. I am running one now in fact.

https://www.ebay.com/itm/rca-6as7g-tube/183070395857?epid=0&hash=item2a9fd88dd1:g:TmIAAOSwqfZagSu1


----------



## buldogge

chimney189 said:


> Good day everyone,
> I recently purchased a BH Crack w/SB upgrade.
> I'm currently using Tung Sol 7236 and Telefunken 12AU7.  The sound is a great balance between warmth and clarity, but I'm missing bass slam and punchiness (the bass slam seems near non-existent).
> 
> ...



I like the TS 7236 a lot as a 5998 alternative...especially since they can be picked up for around $25-30!

Have you considered pairing it with a 6SN7?...Maybe a KR V-231 or a NU Black Glass? (need Garage1217 adapter, as well)

I'm running a 7236/TS Mouse Ears combo myself on The Crack/SB (plus choke/diodes/films) and it is quite nice.

There's also the question of which phones you're using, of course.  I use mine with T90s and HD700s FWIW.

-Mark in St. Louis


----------



## chimney189

buldogge said:


> I like the TS 7236 a lot as a 5998 alternative...especially since they can be picked up for around $25-30!
> 
> Have you considered pairing it with a 6SN7?...Maybe a KR V-231 or a NU Black Glass? (need Garage1217 adapter, as well)
> 
> ...



I'm using the HD 800S


----------



## FunyunBreath (Apr 3, 2018)

I have quite a few 6SN7 tubes as well, along with the garage 1217 adapter. Overall they have a much darker sound signature than 12au7 types, which can be quite nice with the HD800. I rarely use them though because they tend to be more prone to microphonics and have a higher noise floor in my crack.

Of the 6sn7's I have, the Tung Sol Mouse Ear, and Sylvania JAN VT-231 are my favorites.


----------



## Allanmarcus

I thought the Tung Sol 7236 was a ruggedized 5998. I also thought, based on reading about them on the Bottlehead forum a little, that they sound the same.

I'm currently using a Tung Sol 7236 and a Telefunken ECC82 (12AU7), and I'm not lacking for bass, but I don't listen to EDM or anything like that.


----------



## bloodhawk

Allanmarcus said:


> I thought the Tung Sol 7236 was a ruggedized 5998. I also thought, based on reading about them on the Bottlehead forum a little, that they sound the same.
> 
> I'm currently using a Tung Sol 7236 and a Telefunken ECC82 (12AU7), and I'm not lacking for bass, but I don't listen to EDM or anything like that.



Partially true, but the transconductance on the 7236 (12000, iirc) is lower than that of the 5998 (15000)


----------



## FunyunBreath

There's a pretty significant difference to my ears between the two. Once upon a time I had 2 Speedballed Cracks and an A/B switch so that I could instantly switch between different sets of tubes in the same circuit 

The bass difference between the tubes isn't so much "quanitity" but rather quality. 5998 has more texture/slam and goes deeper, 7236 is faster and clearer but overall much less interesting.

Clarity/detail between the 2 tubes is about identical though.


----------



## Allanmarcus (Apr 3, 2018)

I wonder if the impedance is just so high on the crack that the 5998, or even the 421a, lower it enough that dampening factor comes into play, and the Crack can control the driver better with those tubes, even 600 ohm headphones.

Update: I got this info TubeWorld. I need to learn what these mean

*5998=421A Dual Power Triode*
(5998 is an uprated 6AS7G and has a 13 watt plate dissipation rating)
(the 5998 sounds very clear and has superb overall sonics,
 the 421A Western Electric sounds even better; slightly more magical sound)
(5998 Mu = 5.4, Gm = 15500, Rplate = 350 ohms, Vplate max = 250 volts and Vplate max 5998A = 275V)
(7236 Mu = 4.8, Gm = 12500, Rplate = 350 ohms, Vplate max = 300 volts)
(7236 is a computer rated 5998A, 7236 and 5998A are uprated from 5998)
(6AS7G Mu = 2, Gm = 7000, Rplate = 280 ohms)
(6080 Mu = 2, Gm = 6500-7000, Rplate = 280-300 ohms)

5998 substitute = 7236
7236 is a computer rated 5998A


Update 2: interesting article here: http://www.tubeaudiostore.com/tubmatdem.html


----------



## Paladin79 (Apr 3, 2018)

It has been a while since I studied tube theory but Mu as I recall is voltage gain. Gm is transconductance. That amp starts out with a stock 6080 and I would think the bias voltage is based on that tube. The 6as7g is quite close so I found it to be a decent match. I probably should have done more testing when I had two stock cracks side by side just as Funyun did but my interest was in other areas

Ok I just tried various tubes I have laying around, please note I do have VU meters on my Crack amp, the Tung Sol 5998's had a higher volume level than Chatham 6080, GE 6080, RCA 6AS7G, 6H13C's etc.  Quality of sound, that is a bit debatable.

test music... Otis Redding  Dock of the Bay, Warren Zevon..Nighttime at the Switching Yard.


----------



## attmci (Apr 4, 2018)

Paladin79 said:


> It has been a while since I studied tube theory but Mu as I recall is voltage gain. Gm is transconductance. That amp starts out with a stock 6080 and I would think the bias voltage is based on that tube. The 6as7g is quite close so I found it to be a decent match. I probably should have done more testing when I had two stock cracks side by side just as Funyun did but my interest was in other areas
> 
> Ok I just tried various tubes I have laying around, please note I do have VU meters on my Crack amp, the Tung Sol 5998's had a higher volume level than Chatham 6080, GE 6080, RCA 6AS7G, 6H13C's etc.  Quality of sound, that is a bit debatable.
> 
> test music... Otis Redding  Dock of the Bay, Warren Zevon..Nighttime at the Switching Yard.


In the Crack, the 6080 is setup as a cathode follower, which has a fixed plate voltage.

The driver stage is a common grounded cathode amplifier. It's cathode voltage is set by the 1.57V LED, and the plate is loaded with a 22.1K resistor.


----------



## Paladin79 (Apr 4, 2018)

That certainly  makes sense Atmci, I get so involved with other projects that I do not think about the Crack setup very often. I could recall the LED setup.


----------



## Kitchener

Hello.
My account is quite fresh around here.
I've been lurking for about six months, trying to absorb as much as possible from this ever expanding thread, but only registered recently.
-to bother Ohcrapgorillas for details about his Crackhouse, incidentally.

Anyway, I'm hoping someone here might be able to lay some wisdom on me with regards to putting a choke in the Crack PSU.

I've purchased a Hammon 157M choke to replace a resistor in the PSU.
Specs: 8H, 100mA, 259Ohms, 400V.

I've seen it posted that stuffing a choke in lets you replace the last electrolytic capactor in the PSU with a film capacitor with weaker specs and, more importantly, smaller dimensions than a 220uF 250V+ film cap.
-this Reddit post had some details but the comment appears to have vanished.

Sooo, given my choice of choke, would it be advisable for me to replace the lytic cap with a 100uF 250V film cap?
-Or should I just put in a choke and bypass the last lytic with a 2.2uF film cap?

Thanks for reading.
Disclosure: I have a similar thread over at Bottlehead where I initially just asked for alternatives to the Triad C-7X.


----------



## attmci (Apr 5, 2018)

Kitchener said:


> Hello.
> My account is quite fresh around here.
> I've been lurking for about six months, trying to absorb as much as possible from this ever expanding thread, but only registered recently.
> -to bother Ohcrapgorillas for details about his Crackhouse, incidentally.
> ...



I knew you from the Bottlehead. Did Doc. B. ignore you there? Unbelievable.

I saw a lot of your questions had been answered: https://bottlehead.com/smf/index.php?topic=10729.0

BTW, if you wanna to replace the last caps, you need a pair. And yes, the quality film caps are expensive.


----------



## Kitchener

attmci said:


> I knew you from the Bottlehead. Did Doc. B. ignore you there? Unbelievable.
> 
> I saw a lot of your questions had been answered: https://bottlehead.com/smf/index.php?topic=10729.0
> 
> BTW, if you wanna to replace the last caps, you need a pair. And yes, the quality film caps are expensive.



Oh no no, I find they’re very helpful over at Bottlehead. They generally put up with my rambling 

I’m just “throwing a wide net” trying to gather as much info as possible.

A pair?
Are you referring to the pair of output capacitors?

I’m already replacing those with a pair of Mundorf 100uF 250V film caps.

The PSU has three electrolytic capacitors, each rated at 220uF 250V.

I could be mistaken, but I mean to recall reading that fitting a choke will let you replace the last of the three PSU caps with a single film cap; not a pair.


----------



## buldogge

Kitchener said:


> Hello.
> My account is quite fresh around here.
> I've been lurking for about six months, trying to absorb as much as possible from this ever expanding thread, but only registered recently.
> -to bother Ohcrapgorillas for details about his Crackhouse, incidentally.
> ...



You can proceed exactly as you have written...either way works. I used the Triad but th Hammond 157M would be fine, as well.

Also, you can replace either resistor with the choke.  I chose to replace the 1st one (across along the back)....thus C-L-C-R-C...C-R-C-L-C is also fine.

I opted for a 2.2uf bypass, as I also did the schottky diode bridge...but...a 100uf 250v film works very well, here.

-Mark in St. Louis


----------



## Kitchener

buldogge said:


> You can proceed exactly as you have written...either way works. I used the Triad but th Hammond 157M would be fine, as well.
> 
> Also, you can replace either resistor with the choke.  I chose to replace the 1st one (across along the back)....thus C-L-C-R-C...C-R-C-L-C is also fine.
> 
> ...



Thanks a lot, Mark!
This was great, exactly what I was looking for.

I’m probably going to try a bypass at first.
-I’ve already ordered one, along with some bypasses for the output caps, so I’ll sit on my wallet for now.

I think there’s been some discussion about what resistor to replace, but as I recall in the end it didn’t really matter?

It doesn’t matter how I hook up the choke, correct?
-polarity is irrelevant here?


----------



## buldogge (Apr 5, 2018)

Kitchener said:


> Thanks a lot, Mark!
> This was great, exactly what I was looking for.
> 
> I’m probably going to try a bypass at first.
> ...



Wiring connection choice shouldn't matter much...This what Paul Joppa wrote over on the Bottlehead Forum, some time ago, regarding the wiring/ dot marking on the C-7X choke:

_"Yes there is some sense to twisting the wires (minimizing the current-loop area.

The choke works by reducing the current fluctuations of the power supply, but it does not of course completely eliminate them. The twisted wires reduce the magnetic hum field generated by the remaining fluctuations.

The most important twisting is the heater power wires, where the fluctuating current is very high - 2.5 amps for the 6080 heater.

The dot usually signifies the start of the winding, standard practice it to use that with the highest AC voltage, i.e. the input of a filter choke. In this application the difference will be very tiny, so don't stress."_

-Mark


----------



## Kitchener

buldogge said:


> Wiring connection choice shouldn't matter much...This what Paul Joppa wrote over on the Bottlehead Forum, some time ago, regarding the wiring/ dot marking on the C-7X choke:
> 
> _"Yes there is some sense to twisting the wires (minimizing the current-loop area.
> 
> ...



Aha, I remember reading that!
-I suck at finding stuff I _know_ I’ve read _somewhere_.
Thanks for the quote.


----------



## Allanmarcus (Apr 5, 2018)

Another thing to so to help with power is to upgrade the included rectifiers with Schottky diodes. This was discussed on the Bottlehead board too. Not a hard mod, but it does require removing the 4 rectifiers. I desoldered them, but in hindsight, I should have just clipped them off (easier).

Here's how I did it. I got some help from a super friend with the wiring diagram

Note, I decided to just let the diode board hang since the green wires are pretty stiff. Other options include a 1" nylon spacer and some drilling, or super glue.

Does it sound better? The parts where like $10. It sounds $9.95 better  I already have the choke as well. I supposed I could upgrade the caps, but meh.

BOM:

4 cree "Schottky" diodes (Parts Connexion # DIODES-68247) $1.50/ea
1 small board (Parts Connexion # PCB-77727) $1.95











My crack story: https://sites.google.com/marcusfamily.info/diynotes/my-stuff/bottlehead-crack


----------



## bloodhawk (Apr 5, 2018)

Allanmarcus said:


> Another thing to so to help with power is to replace the rectifier with diodes. This was discusses on the Bottlehead board too. Not a hard mod, but it does require removing the 4 rectifiers. I desoldered them, but in hind site, I just have just clipped them off (easier).
> 
> Here's how I did it. I got some help from a super friend with the wiring diagram
> 
> ...




Nice! That should help a lot of new comers ...

This is what my crack looks like  ...im in the process of moving this over to a 10x10 panel and a larger frame - https://imgur.com/a/EYi11 (Album)


----------



## attmci (Apr 5, 2018)

bloodhawk said:


> Nice! That should helo a lot of new comers ...
> 
> This is what my crack looks like  ...im in the process of moving this over to a 10x10 planel and a larger frame - https://imgur.com/a/EYi11



Nice job on the upgrades. 

I am so glad I hadn't taken the same route. LOL


----------



## bloodhawk

attmci said:


> Nice job on the upgrades.
> 
> I am so glad I hadn't taken the same route. LOL



Haha yeah, it was pretty tricky to get everything in there. And now since i dont use the Crack as much , rarely actually, wanted to move to a more spacious panel and clean things up.


----------



## Kitchener

Oh my god, I love you!
-both of you that is! 
I love seeing how people mod their Cracks, it's such a great source of inspiration.
Those albums/guides are right up my alley, Bloodhawk and Allanmarcus.
Especially for someone like me who don't know s**t about circuitry; learning by doing/asking (monkey see, monkey do).

My plan right now is:

Get the Speedball in, once it gets here (I've ordered both my BH kits over holidays; Crack before Christmas, Speedball before Easter, waiting can be torturous!)
Then I'm fitting Mundorf Mcap MKPs (100uF, 250V) as outputs with 1uF Mundorf bypasses (I'm basically copying this guy)
TKD 2CP-601 pot.

Choke, Hammond 157M.
And either a 100uF 250V cheapish film cap replacement or just a 2.2uF bypass on the last lytic cap in the PSU.
I've been thinking of doing the Cree mod, but I haven't done any research on it so I was a little apprehensive.
But that great photo you posted, Alanmarcus, has pushed me over the edge; I'm totally doing that!
Thanks a lot 


*By the way.*
I'm going to fit the output caps with metal brackets/clamps, these.
But pretty much _everyone_ else uses strips.
Can metal fastenings result in problems with grounding/noise/something? -I'm baring my ignorance here, so bear with me


----------



## bloodhawk

Kitchener said:


> Oh my god, I love you!
> -both of you that is!
> I love seeing how people mod their Cracks, it's such a great source of inspiration.
> Those albums/guides are right up my alley, Bloodhawk and Allanmarcus.
> ...



No problemo. Feel to shoot me a PM or post here if you need any help. 
This is how i had my rectifier bridge setup before the actual tiny PCB got delivered xD - https://imgur.com/a/b2bgr

The brackets shouldn't be a problem, till the time they are not shorting or coming in contact with any active joints. That ones reason why a lot of people like to use zip ties .

Another cool way would be to use these - https://www.amazon.com/gp/product/B01GSXN45K/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1 or These - https://www.amazon.com/gp/product/B01HR9VS4I/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1
Swap out the existing double sided tape with some Gorilla Double sided tape and then run zip ties through them. 

That photo Alanmarcus posted with the proper pinouts should pretty much be made sticky lol.


----------



## Allanmarcus

bloodhawk said:


> That photo Alanmarcus posted with the proper pinouts should pretty much be made sticky lol



Sorry, this is the Crack thread, not the S.E.X. thread!


----------



## attmci (Apr 5, 2018)

bloodhawk said:


> Haha yeah, it was pretty tricky to get everything in there. And now since i dont use the Crack as much , rarely actually, wanted to move to a more spacious panel and clean things up.


Man, you should tell the guy if the replacement of the Crack PSU cap has any impact on the sound quality. I doubt that.

If that's true, then, what's %? 1, 2, 3%?

But don't get me wrong. The Crack is a great $400-500 amp.


----------



## bloodhawk (Apr 5, 2018)

Allanmarcus said:


> Sorry, this is the Crack thread, not the S.E.X. thread!



Im confused? I dont see any S.E.X related post?



attmci said:


> Man, you should tell the guy if the replacement of the Crack PSU cap has any impact on the sound quality. I doubt that.
> 
> If that's true, then, what's %? 1, 2, 3%?
> 
> But don't get me wrong. The Crack is a great $400-500 amp.



Well towards sound i dont think so. At least nothing major changed. The most difference i noticed with PSU mods was with the rectifier that really cleaned up the background. From what i remember, the only noticeable difference would be apparent if one replaces all the PSU caps with equivalent (or larger) film caps. But the problem is that film caps of those values are 1. too expensive and not worth it  and 2. too large to fit in the stock chassis.

Sonically, as in therms of the sound signature the most difference is noticeable from the output caps and the TKD pot. Stock pot to Alps isnt all that noticeable other than the channel imbalance. But Alps to TKD is a pretty big change.

All in all, there was about a 10-15% change in sound signature after all the mods, if that even makes sense.


----------



## Kitchener (Apr 6, 2018)

attmci said:


> Man, you should tell the guy if the replacement of the Crack PSU cap has any impact on the sound quality. I doubt that.



Fact is, I don't expect to hear _any_ difference from anything other than the Speedball.
Some people are probably going to look at me like I've just fallen out of a tree for saying this.
But I'm not much of an audiophile, frankly.
I had a hard time telling the difference between my phone and the Crack while listeningen through my Beyer DT770.
I haven't bothered trying my Senn HD6XX on my phone because I don't want to have the same experience.

Tube rolling?
Fuggedabboudit, can't tell a Mullard from a Clear Top from a Gold Lion, not  a chance..
-hell, by the time the tubes have warmed up after switching, I can't even remember what the previous tubes sounded like.

Bottlehead clearly state that the Speedball will make a clear, noticable change in the Crack's sound.
So I'm looking forward to that.
But subtle changes, probably not gonna notice.
Film caps? Subtle.
PSU mods? _Very_ subtle.

My point is, I'm just doing this for the fun of tinkering.
-I miss the smell of solder at 2 am.
And as far as I can tell, at least none of these mods will make the sound _worse, _so any noticeable improvement (imaginary or real) is just an added boon 

I'm not saying modding and tube rolling doesn't alter the sound!
What I am saying is that _I_ just don't have the ear for it and I envy those who do.


----------



## attmci (Apr 6, 2018)

Kitchener said:


> Fact is, I don't expect to hear _any_ difference from anything other than the Speedball.
> Some people are probably going to look at me like I've just fallen out of a tree for saying this.
> But I'm not much of an audiophile, frankly.
> I had a hard time telling the difference between my phone and the Crack while listeningen through my Beyer DT770.
> ...



Go for it! And be sure to posts pics.

Not sure if you have a DAC. Otherwise, you may need one.


----------



## Kitchener

attmci said:


> Go for it! And be sure to posts pics.



You bet I will!
I’ve also got some neat new feet for the base coming, nothing like the amazing case mods some people around here do but I think they’ll look cool.


----------



## bloodhawk

Kitchener said:


> Fact is, I don't expect to hear _any_ difference from anything other than the Speedball.
> Some people are probably going to look at me like I've just fallen out of a tree for saying this.
> But I'm not much of an audiophile, frankly.
> I had a hard time telling the difference between my phone and the Crack while listeningen through my Beyer DT770.
> ...




Thats a great mindset along with being the correct one, before going into these mods. A lot of feedback post mods is highly exaggerated, and the most difference you will ever notice is from tube rolling.

But as compared to the DT770 you will definitely notice more a difference with the HD6XX. Because of the output impedance of the amp.


----------



## Paladin79

I went more for looks myself and some of my changes were functional but most times just cosmetic. I did make larger cabinets to have room for future additions. It is probably human nature after paying a large amount of money for some caps or whatever that they should help out but that is another reason I built two stock and listened to them side by side as I started modifying things. Hearing a before and after is never easy.


----------



## Kitchener (Apr 6, 2018)

bloodhawk said:


> Thats a great mindset along with being the correct one, before going into these mods.



I generally try to keep a level head about most things 
I’ll just be happy if I still works when I’m done with it.



Paladin79 said:


> I went more for looks myself and some of my changes were functional but most times just cosmetic.



I’ve been eyeing your latest build with lustful eyes for a long time!
I especially love the VU meters, I don’t really understand what they do, but they look very, very cool.

If I’ve understood this correctly, you use them to visualise balance between channels?

Could I put a VU meter in my normal “one-potted” Crack?
And is it difficult?


----------



## Paladin79 (Apr 6, 2018)

Kitchener said:


> I generally try to keep a level head about most things
> I’ll just be happy if I still works when I’m done with it.
> 
> 
> ...


 The VU meters are a measure of volume units, power. They will show when the channels are balanced and I run separate volume controls so I can tweak the balance a bit anyway. They come as a set with a control board for as low as $20 on EBAY or $30-$40 on Amazon. You can get them with yellow or white bulbs as I recall. The circuit board has a left and right channel input and shared ground, I ran mine off of the last stage, the headphone jack. You can also use that as a preamp out of course. They have some adjustment but the power was a bit high for the meter deflection so I put a current limiting resistor in line with the signal to each meter until I got it measuring into the red portion of the meter at a level a bit higher than I would normally listen.  They are fairly important in my case because I run most all of my amps off of the preamp out of other amps, or dacs and there is generally a master volume control involved. I can see the level before I ever plug my headphones into this crack. If you buy a set I can walk you through setup, I ran a separate 12 v 500ma ac to dc converter to the pc board to light the bulbs.  https://www.ebay.com/itm/2Pcs-VU-Panel-Meter-Warm-Back-Light-Cables-Recording-Durable-Driver-Board-Module/232698469460?_trkparms=aid=555019&algo=PL.BANDIT&ao=1&asc=20150817211623&meid=fda087ad5ed84ec58a9c588fe02145fb&pid=100505&rk=1&rkt=1&&itm=232698469460&_trksid=p2045573.c100505.m3226

Personally I would run two meters in your case, they will always read the same and I prefer the look of two if you have room. I am also a Gemini so I tend to do things in twos anyway. Each meter has four solder lugs on the back, two for the meter and two for the bulbs. I should have a spare set laying around so I can figure out which is which pretty easily. The yellow meters match up very well with edison bulbs on color. I also used magic Eye tubes in one build but on those you best have a very good understanding of electronics, power supplies, and how much current might do you some damage.   Oh I lucked into some 100k single gang ALPS pots that seem stepped like ladder pots, I believe they might use surface mount resistors but I am not positive since they are sealed.

I gave the black amp to my son, the other one has 1/8 inch copper plates on top, front and back. I have turned down some hefty offers for it but it is a keeper.

https://www.amazon.com/Panel-Meter-...UTF8&qid=1523036099&sr=8-1&keywords=vu+meters

At least Amazon gives you a diagram of how to hook them up and this price is a bit better than I have seen before. I can access plugs for the sockets if you decide to get some or you can pull the sockets and hardwire to the control board.

https://www.amazon.com/Magic-EM87-A...qid=1523038218&sr=8-1&keywords=magic+eye+tube

Here is the option I used on another project, the magic eye tube. In this  case it has like a bar graph of green that goes up and down with the change of volume level, comes with its own circuit board.
Sounds easy right? Then you realize you have to use a 250v supply to power this baby. I built my own; unless you happen to have one or have a good plan, I would avoid this option. This is more of a cool effect rather than a calibrated meter. I incorporated it on an amp to win a bet.


----------



## Paladin79

I am working on setting up a set of those meters now for a friend, if you have specific questions I should be able to help. He is coming out of  an extra preamp out so i will have RCA connectors wired to the board. Tomorrow I do the fine tuning.


----------



## bloodhawk

Paladin79 said:


> I am working on setting up a set of those meters now for a friend, if you have specific questions I should be able to help. He is coming out of  an extra preamp out so i will have RCA connectors wired to the board. Tomorrow I do the fine tuning.



Pictures of how you wire it up would be highly appreciated , if possible!


----------



## Paladin79

The wiring is on the amazon link I posted above. In this case i just went left to right, green, black, red, yellow and repeated. I hooked a 12 volt ac to dc converter to the orange plug, and the light is working. The bottom green three pin plug is marked L in ( left channel in), center is shared ground, R in is Right channel in. I will have RCA cables hooked to it in a few minutes and into a preamp; out fairly soon.


----------



## bloodhawk

Paladin79 said:


> The wiring is on the amazon link I posted above. In this case i just went left to right, green, black, red, yellow and repeated. I hooked a 12 volt ac to dc converter to the orange plug, and the light is working. The bottom green three pin plug is marked L in ( left channel in), center is shared ground, R in is Right channel in. I will have RCA cables hooked to it in a few minutes and into a preamp; out fairly soon.



Basically meant inside the amp 

But thank you nonetheless!


----------



## Paladin79 (Apr 7, 2018)

I mentioned that up above but I can explain it again. The board has a left, right and ground input. You can wire directly to your headphone jack, that is where you plug in your quarter inch male connector. It has been a while since I built one but I believe it uses red for right, black for ground, and white wire for left channel. This took me all of 15 minutes to wire and incredibly it is matched up to my preamp out stage I just plugged it into. It will be ready to go for my friend tomorrow with RCA connectors on it to plug into the back of his Jotunheim. The first photo was earlier today, I work with this type of thing so if my explanation was not very good I will try to explain it better.

If I wired this to a quarter inch trs connector, instead of the two rca connectors, I could plug straight into my crack amp right now and run two sets of meters off of the same amp lol. No sound, just meters.


----------



## Kitchener

Thanks a lot for the info Paladin79!

I've been a little busy over the weekend so I haven't had time to reply.



Paladin79 said:


> The VU meters are a measure of volume units, power. They will show when the channels are balanced and I run separate volume controls so I can tweak the balance a bit anyway. They come as a set with a control board for as low as $20 on EBAY or $30-$40 on Amazon. You can get them with yellow or white bulbs as I recall. The circuit board has a left and right channel input and shared ground, I ran mine off of the last stage, the headphone jack. You can also use that as a preamp out of course. They have some adjustment but the power was a bit high for the meter deflection so I put a current limiting resistor in line with the signal to each meter until I got it measuring into the red portion of the meter at a level a bit higher than I would normally listen.  They are fairly important in my case because I run most all of my amps off of the preamp out of other amps, or dacs and there is generally a master volume control involved. I can see the level before I ever plug my headphones into this crack. If you buy a set I can walk you through setup, I ran a separate 12 v 500ma ac to dc converter to the pc board to light the bulbs.  https://www.ebay.com/itm/2Pcs-VU-Panel-Meter-Warm-Back-Light-Cables-Recording-Durable-Driver-Board-Module/232698469460?_trkparms=aid=555019&algo=PL.BANDIT&ao=1&asc=20150817211623&meid=fda087ad5ed84ec58a9c588fe02145fb&pid=100505&rk=1&rkt=1&&itm=232698469460&_trksid=p2045573.c100505.m3226
> 
> Personally I would run two meters in your case, they will always read the same and I prefer the look of two if you have room. I am also a Gemini so I tend to do things in twos anyway. Each meter has four solder lugs on the back, two for the meter and two for the bulbs. I should have a spare set laying around so I can figure out which is which pretty easily. The yellow meters match up very well with edison bulbs on color. I also used magic Eye tubes in one build but on those you best have a very good understanding of electronics, power supplies, and how much current might do you some damage.   Oh I lucked into some 100k single gang ALPS pots that seem stepped like ladder pots, I believe they might use surface mount resistors but I am not positive since they are sealed.
> 
> ...




Those links were very helpful for getting a grasp of what components are required.

So to hook up a meter I'll need a circuit board for the meters and a separate converter to power them?
I'm quickly running out of space in my Crack! 
But I think I might be able to mount those boards along the inside walls maybe,

I have some rather large corner brackets and feet incoming that might take up quite a bit of surface area in my Crack, so I'll need to make some measurement before I decide wether it's even possible to fit VU meters.

I've been browsing for meters on eBay, but it's been hard finding one that might fit.
While I really like the look of the meters you've used, I don't want them to protrude very much from the Crack.
-preferably I'd want the meters to almost run flush with the front of the Crack.

I found one that might fit the bill: https://www.ebay.com/itm/291034519630
But it has blue LEDs and I really don't want that 

But how to do you hook up the converter?
Could you perhaps take a picture of where you have connected the ac/dc converter to your power supply?
And also a picture of how you connect the VU-circuit board to the output jack?


----------



## Paladin79 (Apr 8, 2018)

The kit i showed you does come with the circuit board of course. The AC to DC converter (you have to purchase this separately) plugs into a wall outlet, I did not wire it into the Crack power supply. I mounted the meters on an 1/8 inch copper plate from the front but i could have done a flush mount as well. I wanted to show the brass screws on the front of the plates but I could have mounted these flush as well. Mounting from the front hid any imperfections in the circular holes I made and while I have ten hole cutters, the closest one in size was a bit bigger than the meter so I hid that gap as well.

Because of the way I built my Crack amps, it is not easy to show a photo of that 1/4 inch jack but I described it in an earlier post. Look in your Crack build instructions and you just need to know left channel, right channel and ground. White wire, red wire and black wire. I used a totally different 1/4 inch jack on mine and photos would probably be more confusing than helpful. Think of it this way, I can get the same connections plugging in a 1/4 inch male plug into my Crack amp, you just need to be on the wire side of the connector.

The meters themselves are right at 34 mm diameter. with 6.55 mm depth before the square frame with the holes.  Here you see the ac-dc adapter and it goes to the orange plug. ( red wire to 12 v, black wire to zero)The three pin green plug at the top connects to two RCA male connectors in this case but to mount it in a Crack you would wire to the lugs on the backside of your 1/4 inch connector. All other connections go to the meters.

I do not know about other meters and their circuit boards, I have worked with this style five times and I cannot speak for other products. These are imported and there are not a lot of instructions but luckily Amazon posted some good drawings.

I built my Crack amps with extra space and the plate onto which I mounted the meters and the left and right volume controls is four inches square.One option for you would be to add pre-amp out female RCA jacks to your crack and plug the meters in there and build them into a different box. Like I said, I have a friend coming in who just wants the meters so he can plug them into the pre-amp outputs on his amp. The rca jacks would hook up exactly like the meters, left channel, right channel and ground. I added those to the back of the black Crack I built but then I use four inch plates and a larger cabinet. Before I touched the crack kit I knew what changes I wanted and worked toward those.

I found some photos of the inside of one of my Cracks but I had not wired to the jack yet and soon changed it out for a metal jack. All metal on my steampunk crack is either brass or copper, my cables even matched, as did my headphones and headphone stand.


----------



## Paladin79 (Apr 8, 2018)

I found an original 1/4 inch Jack from the kit, those are the three connections I described, one with white wire (left channel) Red wire, right channel, and black wire for ground. I used shielded twisted pair audio cable, two wires and a ground and matched those up on the jack, and input jack on the circuit board for the meters. You end up with two wires on each lug instead of one. There is a common ground, the black wire is ground. If you were to wire this to two rca jacks for a preamp out, you would run the ground from each connector to the black wire, then white to left and red to right.

The opening for this jack is on the right, if you insert the male plug, it matches up to this order, tip, ring, sleeve. Tip is white wire, ring is red, sleeve is black.

The black carbon fiber crack I showed earlier is just two standard wooden cases glued together, they allowed for most anything I wanted to do. It is just a matter of gluing them, using wood filler, then a whole lot of sanding and multiple coats of black spray lacquer. I used up more time working on that cabinet than any portion of the crack build.


----------



## Kitchener

Thanks a lot for taking the time, Paladin79 

So when you hook the meters to the jack, you just connect them directly to where the black/red/white wires are connected on the jack?
-Like one would hook up a bypass capacitor?

The meters need a separate power supply?
I'm fast running out of power outlets at my office (as well as space in my Crack) so I might have to give meters a pass in this Crack.
I was hoping it would just be a matter of hooking them up to the power plug inside the Crack.
Show how much I know about circuitry! (nothing, that is, I understand _nothing _)
-my only previous experience with DIY electronics comes from building keyboards, like this one.

Proper woodwork is a nothing short of a massive hassle.
I read up a bit on surface finishes before I got the Crack.
And just reading about the elbow grease involved in applying Danish oil made me want to lie down.
In the end I just opted for a plain, clear poly coating.

What you've done with your builds is incredible, just beautiful


----------



## Paladin79 (Apr 8, 2018)

I appreciate your kind words.

You can connect them directly to the solder lugs. They do have to be soldered. I could internally wire an ac outlet into the crack but for me it is just as easy to use an outlet strip such as this.

https://www.amazon.com/Certified-EZ...1&sr=8-1-spons&keywords=ac+outlet+strip&psc=1

I also like to keep a less expensive transformer like that outside of the Crack circuitry. I used Danish oil on this crack but it is quartered oak, and deserving of a good finish. The electronics goes pretty quickly for me so I am more apt to spend time on other aspects of the build. 

A fascinating keyboard! Maybe there is a language barrier here but if you can wire that, a quarter inch jack should not be much of an issue lol.


----------



## Tom-s (Apr 16, 2018)

I fired my Crack up again after a year of sitting around, collecting dust, just on my desk.
Yesterday i started out with a afternoon of tube rolling European ECC82's.

Decided that i like my Philips Valvo factory tubes the best.

Got onto tube rolling 6SN7's. I prefer the Brimar 6SN7GT (1963) over de 6H8S Melz metal plate and round plate black glass VT-231's.

Going back in time the 6F8G is the predecessor to de 6SN7's. Those Tung-Sol round plates (1938) are great tubes.

But now i tried new ones, ECC32 labeled Adzam (pre 1955). It's a British made tube with the insides comparable to the Brimar.

The sound is very lush, open, lots of detail retrieval, suberb mids, easy highs , laid back, (i'm not good at this).

Bass is weak, detailed, but weak (even with Tung Sol 5998, Bendix Graphite plates).

When used in Crack. Use it only in a speedballed Crack with the extra resistor options in place.

When using standard R1 the ECC32 tubes display 115V+-, with R1 on E80CC mode it's a better fitting 80V+-.

So that makes tube rolling a little difficult since switching would be required.

For now i compared it to E80CC pinched waist Philips tubes and it is more open/airy, more details, less bass.


----------



## S.S.R.I (Apr 23, 2018)

Hi,

I purchased a crack 1.1 otl kit via someone who lives in U.S.A.The kit has arrived to me but there is no manual CD inside the box.I have no order number and at the moment i can't reach the person who made the purchase.So i am not sure does bottlehead help for manual.If anyone can help for manual i will be very happy.

Thanks.


----------



## Paladin79

It is downloadable from Bottlehead. i would think if you emailed them and explained your situation they might hook you up with  the link. I have built an earlier version that came with a CD but you certainly need the latest download.


----------



## S.S.R.I

Paladin79 said:


> It is downloadable from Bottlehead. i would think if you emailed them and explained your situation they might hook you up with  the link. I have built an earlier version that came with a CD but you certainly need the latest download.



Thanks for reply.Yes you're right, i need the latest version.I wrote here firstly because i need the manual immediately .If i can't find someone has the latest version from here i will try to contact with bottlehead.


----------



## Kitchener (Apr 24, 2018)

I got a 6SN7 adapter from Garage1217 a couple of weeks ago.
But I'm having some difficulties putting it to good use.

_I think it acts pretty much like an antennae for all electrical interference in my office.
Whenever I try using it there is a high pitched whine, regardless of volume.
The whine goes away as soon as I cup my hands around the adapter like a shield.

So I'm thinking maybe I can try shielding the adapter in some way.
My first thought was getting some sort of tube, metal or plastic, with the right diameter and just put it around the adapter.
But I'm fed up with **** money away, so I want to MacGyver something instead.

I've got loads of Sugru lying around.
Could I mold a housing of Sugru around the adapter?
It's non-conductive, so it could act as insulation.
Should I try putting some wiring inside the Sugru to better shield against interference?_

Edit:
Nah, nevermind it's just the tube picking up more interference than the 12AU7.


----------



## Kitchener

This is pretty much a straight copy of my post over at Bottlhead, but I figured maybe someone over here might appreciate it as well. Whore for attention, that I am.

Let me present my, pretty much finished (for now), Crack:

*IRONCLAD*
​-or_ *Brass Shithouse*_, alternatively.


*Mods:*
Speedball
Output Caps: Mundorft MKP, 100uF 250V
Choke: Hammond 157M
Pot: TKD 2CP-601
Power Bypass Cap: JB JFX, 2.2uF 250V

​
*Cosmetics:*
Polycoat for base
Clearcoat for transformer bell
Knob: Elma Marconi Classic British Wing Knob from HifiCollective
Brass corners: Heart of Brass Etsy store

​
*Pictured tubes:*
Mullard 6080
Mullard 12AU7
-just because they fit the IRONCLAD (capital letters required) theme

​
Before I move on to some more detailed descriptions of the mods, let me just make it absolutely clear that I am an awful audiophile.
I have almost no frame of reference, my experience with amps is limited to once owning an APPJ "something" and still owning a couple of broken down old Tandberg receivers (next project: restoring them!).
To be completely honest, I just did all this for the fun of building.
And to be even more honest, I thought the Crack sounded wonderful without mods, and after mods it ...errr still sounds wonderful. But I can't for the life of me tell what's different.
But I did find the bass more punchy and clear after the Speedball, so that's nice.

*Speedball:*
Not much to say, order the kit and stuff it in.
Audible difference: *Nicer bass.*

*Choke:*
I debated wether to suspend the choke from the top plate or mount it in the base.
In the end I decided to screw it to the inside wall of the base, where I think it fit rather nicely.
I might stuff in another choke just to adhere to the IRONCLAD theme...nah.
Audible difference: *Not that I could hear. My Crack was dead quiet before and is still dead quiet.*

*Power bypass:*
The small film cap was cheap so I figured "why not".
Bypassed the last cap in the PSU.
Audible difference: *Nah.*

*Pot:*
There was a slight, expected, imbalance at lower levels with the stock pot.
So I figured, "why not".
Went for a TKP pot just because lot's of people go for the Alps.
The stock pot was just as smooth as the TKP, I find the TKP takes a little more force to rotate.
The TKP fits in the plate hole, so no need for filing.
But the “locking tap” makes the pot’s terminals face away from the nine pin socket and it’s considerably smaller than the stock pot, so you might have to choose between running longer wires to and from the pot or figure out how to mount the TKP facing another way.
I ended up putting an extra nut on the pot, so the locking tap didn’t reach the plate. But the pot is still a little small, so my wiring to and from the pot is a mess, gonna fix it up some day.
Audible difference: *better channel balance at lower volume levels.*

*Output caps:*
These are probably my favourite.
Not because of the sound, just because I like the look of them.
But soldering the fat leads with a 15W iron was an enormous pain in the ass; took ages to heat up.
They’re suspended below the top plate by metal mounting clamps. I quite like the clamps as they’ll let me swap caps quite easily if needed and they look sturdy.
Audible difference: *sorry, can’t hear it.*

*Brass corner pieces:*
I wanted some square, metal feet for my Crack.
It was pretty much impossible to find exactly what I pictured so I landed on these metal corner guards that I mounted like legs.
While I quite like the look, the Crack has gone from an intriguing oddity on my desk to a brutal and ostentatious behemoth.
Audible difference: *by far the largest sonic improvement of any modification.*

 ​
*Conclusion:*
As I’ve said, I have a poor frame of reference and a poor audiophile ear.
So when I say that I can’t hear an improvement in the sound of my Crack, it’s just that: *I can’t hear it*, not saying it’s not there.
Besides, by the time I’ve actually installed a mod, I’ve forgotten what the damn thing sounded like before!
I had a stock Crack about three months before I started modding it.
I’m still not quite done with the Crack. I’m going to put in some new wires to and from the pot, reflow a couple solder joints and I’ve also got two bypasses for the output caps lying around. But after that I’m probably done.
As for the whole IRONCLAD thing, I’m well aware it’s just a pretty ordinarily modded Crack with tacky tat screwed on. But it’s mine. IRONCLAD!

The only mod I can recommend is the Speedball.

The other stuff I just did for the fun of tinkering, and if you like that sort of thing: go for it!
Just don’t expect to have your mind blown.
​


----------



## larcenasb

Nice build, Kitchener! When I first started modding, I'd carry the Crack under one arm to my garage, but I felt a bit uneasy...thinking the glued wood base would break apart. So, I now always carry it with two hands just to be safe. Your IRONCLAD Crack will never have that problem haha! What a tank-like beast! Happy listening!


----------



## bloodhawk (Apr 28, 2018)

Kitchener said:


> This is pretty much a straight copy of my post over at Bottlhead, but I figured maybe someone over here might appreciate it as well. Whore for attention, that I am.
> 
> Let me present my, pretty much finished (for now), Crack:
> 
> ...




Nice!

This is exactly the reason why i said in the past the changes are at most 10-5% IF at all.

People will exaggerate the extent of placebo changes to oblivion, end of the day all that matters is good tubes, PERIOD.
Along with that how cleanly you are able to avoid inductance / RFI.

The most anyone will ever hear is a blacker background and slightly more clarity. And the latter will be very much so be because of the former. That too with headphones that cost 3 to 4 times the crack itself.

All that matters is that you are happy with it!

I recently modded two LD MKVI+'s and that is an amp you can hear the differences in, but those are also ONLY audible when very specific parts are changed. But people still go ahead and spend 100's of $$'s on part that maybe make like 0.1% of a difference by making the signal cleaner. 

Here are some images - https://imgur.com/a/7JKlF4o

And the only way i COULD tell that there was a difference, was because i ABX's both the amps  (one post mods and one unmodded). Even then the main difference was noticed using better tubes. (both had same tubes for comparisons) 

But there are people who will argue with me that the Dale resistors that not advertised as non inductive and cost $1.30 a pop are WORSE (and sound worse lol) than the MILLS resistors that cost $6 a pop. The funny thing is that they are made in the same factory lol. At least i couldn't hear a smidgen of a difference between the two.


----------



## Kitchener (Apr 29, 2018)

bloodhawk said:


> Nice!
> 
> This is exactly the reason why i said in the past the changes are at most 10-5% IF at all.
> ...
> All that matters is that you are happy with it!



Thanks!
Good, level headed takes all round.

I’m quite happy with it, apart from a scratching noise sometimes when I adjust the volume.
I tried asking over at Bottlehead but no bites yet.


----------



## attmci

Kitchener said:


> Thanks!
> Good, level headed takes all round.
> 
> I’m quite happy with it, apart from a scratching noise sometimes when I adjust the volume.
> I tried asking over at Bottlehead but no bites yet.


That sounds like a pot problem. Did you upgrade the pot?

Try to recycle it several times when the amp is off.


----------



## Kitchener (Apr 29, 2018)

attmci said:


> That sounds like a pot problem. Did you upgrade the pot?
> 
> Try to recycle it several times when the amp is off.



Yeah it’s a new pot, been using it a week.

Here’s a copy of my post over at Bottlehead:

I _speedballed my Crack a week ago.
I installed a new pot (TKD 2CP-601) a week before that.

After installing the Speedball there has been a slight scratching noise when adjusting the volume on the Crack.
It's barely noticeable on my HD6XX Senns (but much more prominent on my 80 Ohm Beyer DT770s)

Some observations:
The scratching is not constant; only slight stabs of scratching when I twist the pot,
the quicker I twist the louder the scratch,
it goes away after a while.

Is this expected behaviour or indicative of some malady?



Just to go off topic right off the bat:
After speedballing, my 80 Ohm Beyers really stopped playing nice with the Crack.
I notice the bass seemingly dropping off sometimes, like the headphones can't keep up.
This does not happen with the 300 Ohm Senns_.


----------



## attmci (Apr 29, 2018)

Kitchener said:


> Yeah it’s a new pot, been using it a week.
> 
> Here’s a copy of my post over at Bottlehead:
> 
> ...



Get another pot to see if you still have the noise. I hate noise.

Crack is not recommended for your _80 Ohm Beyers. Try to use a 5998/421A/*two 6bl7 *to see if you may get better results._


----------



## Kitchener

attmci said:


> Got another pot to see if you still have the noise. I hate noise.
> 
> Crack is not recommended for your _80 Ohm Beyers. Try to use a 5998/421A/two 6bl7 to see if you may get better results._



Might have to ask the retailer if they think the new pot might be covered by some sort of warranty.
-or just put the stock pot back in.

I brought up the Beyers pretty much just because I finally seem to have discovered what using unsuited headphones might sound like 

The scratching is barely noticeable with my 300 ohm Senns, though. And seems to go away completely after the amp heats up.


----------



## Allanmarcus

Sounds defective to me. Best to swap it out now than deal with it.


----------



## bloodhawk

Kitchener said:


> Thanks!
> Good, level headed takes all round.
> 
> I’m quite happy with it, apart from a scratching noise sometimes when I adjust the volume.
> I tried asking over at Bottlehead but no bites yet.



Its odd for TKD pots to be defective. Does it always happen at the same positions?

I had a similar issue in my MK VI+, but it went away after a while, turned out one of the solder joints was cold after all the mods. I had to go over all joints close to a power tube as the voltages around that tube were a bit wonky. 

Might help to do a voltage check, and see if anything odd shows up, or do the poke with a wooden chopstick test.


----------



## Kitchener

At least all the voltages on the Speedball were good right after assembly.
I'm going to give the whole build a good do over with the soldering iron, just need to get it home from the office.


----------



## larcenasb (May 1, 2018)

Okay, I think I'm done! First off, the value of the Crack is simply astounding...plus the learning experience of trying out different upgrades makes this a totally worthwhile long-term investment. As a rule, I limited the cost of any one upgrade to $20 max (besides the Speedball of course). Cree Schottky diodes, Triad C-7X choke, Alps pot, Mogami input cable, Audyn Q4 ouput caps & last PS cap ($16.70 ea...), Jantzen Superior-Z to bypass last PS cap, Nippon Chemi-Con 470uF PS caps, ClarityCap PX 4.7uF bypasses for other two PS caps, 6SN7-to-12AU7 adapter, 1940s 6SN7 tube (patience on eBay), preamp circuit...all under $20. So, over the course of a few years, this made the cost of the end product very easy to live with. Not to mention getting to listen through it each night is never-endingly satisfying. 

Sadly though, it's been the end of my upgrade journey for some months now. And, so, just for kicks, I thought I would just do one final upgrade. I decided to replace the Jantzen bypass with an Audyn Tri-Reference 0.68uF (my film caps are 68uF). The Audyn truly looks kingly, and so unsurprisingly the price was a little steeper ($25 shipped)--I finally violated my cost rule haha. It's difficult to say what exactly changes in the sound with each upgrade, all together though, the film caps and PS upgrades seem to allow a more dynamic and smoother sound. Improvements I can be certain about however, are that the PS upgrades made the scratchy interference go away when the volume is maxed; the Alps pot fixes the channel imbalance at low volumes; a 6SN7 greatly improves the width, body and weight in the sound; and padding the pot allows for more range in volume before it gets too loud. The rest is more comfort, just knowing the guts of my amp are top notch. Hope all of you are enjoying your learning and experimenting with this gem of a kit. Happy listening! 

EDIT: It's important to note about any possible subjective changes in the sound...that the stock kit with the Speedball is already fantastic and totally satisfying. More important to good sound is good cans, a good source (don't skimp on this), and good tubes.


----------



## Kitchener (May 20, 2018)

I’m a little intrigued by the funky looking electrostatic Stax Lambdas.
But I’m a little confused by their specs.

Would the Lamba SR Pro work with the Crack via their SRD-series adaptor?

It seems like the Stax adapters have an input impedance of 30 Ohms, but I’m not entirely sure so I figured it might be best to ask.

EDIT!
Never mind:
https://www.head-fi.org/threads/the-entry-level-stax-thread.676272/page-191#post-14251653


----------



## hawkwindx

Which DAC, if any, are you all using with your Crack?


----------



## DavidA

hawkwindx said:


> Which DAC, if any, are you all using with your Crack?


Teac UD-301, Biforst Uber, and Bifrost MB


----------



## bloodhawk

hawkwindx said:


> Which DAC, if any, are you all using with your Crack?



NFB 11.28 or the Topping DX7s.


----------



## Paladin79

I am using the Topping DX7 and listening to a new Binaural + Chesky album Meiko, Playing favorites. I listened to some class A transistor amps with balanced out but the Crack makes this album sing. Another amazing Chesky recording.


----------



## Allanmarcus

How about folks just post their gear/chains in their sigs and profiles, and if one wants to know which DACs, just scroll back a bit.


----------



## Paladin79

I like to think for myself, besides my gear chain is a little too complex for that. Right now, 3 dacs, 10 amps, two speaker power amps etc. It is easier to say what I currently have switched in.


----------



## DavidA (May 26, 2018)

Allanmarcus said:


> How about folks just post their gear/chains in their sigs and profiles, and if one wants to know which DACs, just scroll back a bit.





Paladin79 said:


> I like to think for myself, besides my gear chain is a little too complex for that. Right now, 3 dacs, 10 amps, two speaker power amps etc. It is easier to say what I currently have switched in.



I'm like @Paladin79, a bit too much changes in the gear/chain to have in my sig.

@Paladin79, love the "trip over it" part of your sig, LOL.  Its like my GF and her shoes


----------



## Paladin79

Thanks David!  I am going to PM you a couple photos of my current DIY project, you are going to be surprised.


----------



## buke9

I also like the sig I can relate.


----------



## bigfatpaulie

So....  Anyone else buy yet another Crack during the last sale?


----------



## Tom-s

History:
I'm using my crack for many years now. Updated a bit. A bit more. A bit more. Started doing stuff, just for fun. Tried almost all possible tube types with Crack (have few hundred tubes to roll).
It all started with an AKG k340, another, another, 4 more, sold a few, got some more, sold more, now have 3 left.
Bought Senn HD650, 2 months after that, sold it again. Could better the AKG K340 in bass area, but not for the high, details or soundstage/separation.
Now using HD800's, SuperDupontResonator in place after a month.
Upstream i had a Modi2u, went to Gustard x20, modded a bit, modded some more. 
For the rest, restored speaker (AR), build Ncore based class D power amp for them, build lots of cables just for fun of trying.
I'm now, with the HD800 hearing more difference with tubes then before (relatively speaking), and i think the Crack could be my "weak link".

Question:
Planning on a mainline as my next project but in doubt if it be reasonable / more fun to get a Crack a two (stepped attenuator) first. Would anyone suggest to go via Crack-a-two first? Or just get the mainline, forget about tube rolling and be done with it? Anyone with both that could compare the two (with HD800)?


----------



## bigfatpaulie

Tom-s said:


> Question:
> Planning on a mainline as my next project but in doubt if it be reasonable / more fun to get a Crack a two (stepped attenuator) first. Would anyone suggest to go via Crack-a-two first? Or just get the mainline, forget about tube rolling and be done with it? Anyone with both that could compare the two (with HD800)?



Answer:
It depends.  I have not heard the Crack-a-two but Doc maintains that the Mainline is their top amp (headphone) amp.  If you are a tinkerer and get a lot of joy out of that, which it seems like you do, the Cack-a-two is probably a good option.  Get it, mod it, play around for 2 years with it and when are board with it, like you are with the Crack now, then upgrade to the Mainline.  Rinse and repeat.  If, however, you'd rather not tinker as much, just go for the Mainline.

I don't think there is a wrong answer here.  Is there an amp you are more excited about?


----------



## Paladin79

bigfatpaulie said:


> So....  Anyone else buy yet another Crack during the last sale?



I still have one from a previous sale that is spoken for; I have built a few but moved on to some solid state builds just to break up the monotony.


----------



## R-Oak

quick question, 
- i have yet to order the bottlehead crack, (missed the last sale)
is this build still one of the best bang for your buck to amp senheiser 6xx / 650 / 800 ? 

i'm receiving the 6xx in a month or so, and i am looking at a few combo's
1 - schitt jotunheim + multibit dac (600$)
2 - topping D30 + schiit valhalla 2 (460$)
3 - topping D30 + bottlehead crack + speedball   (410$) when on sale 

the last options seems like the best for the price 
that being said, the bottlehead crack seems like a little old of a design, i know old doesnt meen bad, but the tech world is moving so fast, so it got me wondering 

lastly, being canadian, the exchange rate isnt really great for us up north. i'm lucky to have access to a CNC machine / a few mechanical and electrical engineer's knowledge, all the equipement, i need. so even if i dont have experience myself, i have been enjoying the tought of doing the DIY that is the bottleheadcrack
that being said, i know the top plate and the case work of the crack is probably a good chunk of the asking price, 
and that is the part that i think i could do myself really easy 

did anyone toy whit the idea of making themself a amp, using the bottleheadcrack build, but sourcing all the material themself, while doing a 1-2 upgrade from the start,
like adding the popular Alps Blue Velvet volume control ?


----------



## Paladin79 (Jun 4, 2018)

This is a proven design and a good one for the price with those headphones. Generally speaking, IMHO, some of the best bang for the buck comes from DIY.

I have maybe ten amps and still love the sound from the Crack. I have a Valhalla 2 and prefer the Crack.

As far as doing it yourself from parts, unless you really know what you are doing it is best to build at least one, start there and then decide if you want to go farther. I am fairly experienced with electronics and DIY but found the best way to go was to build one, buy another and then compare any changes to a base unit to be sure I was not downgrading the build by changes I made. (I used multiple plates on my builds, not just the one.)

Procuring a power transformer would be the tricky part of doing your own build. Also considering the time it would take you to source parts, figure out a build, and proceed you would be money ahead buying a kit at the sales price. A big part of this build is telling you to hook a black or red wire between points A and B. Can you read a schematic and do that?


----------



## Allanmarcus

The mass drop cavalli CTH and sdac should be on your list. Also, the Magni 3/modi, multi bit or not. All are good.


----------



## DavidA

R-Oak said:


> quick question,
> - i have yet to order the bottlehead crack, (missed the last sale)
> is this build still one of the best bang for your buck to amp senheiser 6xx / 650 / 800 ?
> 
> ...



A little late to reply here but here are my thoughts:
For the HD650 the Jot and Valhalla2 might be a better match than the BH Crack but it will depend on the tubes used, if you change the power tube in the BH Crack to one with a slightly lower output impedance and use a clean driver tube I like it much better than the Valhalla2 (rolling tubes don't seem to have much effect with this amp) or Jot.  Preferred tubes in the BH Crack for me are TS-5998/WE421A power and Telefunken 12AU7 driver, not the cheapest tubes around but they do sound quite good to me.

For the HD800 I'd take the BH Crack over the Valhalla2 and Jot any day since both the Jot and Valhalla2 with the HD800 is a bit thin and harsh sounding to me.

I'm not a fan of the Topping D30 since to me it was a bit metallic sounding over even the Modi2uber but this is really just a preference thing.  While I don't have the Modi-MB I do have the Bifrost MB and Uber but I'd still take my Teac UD-301 over these two DAC since the UD-301 sounds more extended and smoother to me with the gear that I have but the differences are quite small since most of my friends can't hear any differences between these DACs.

I agree with what @Paladin79 and @Allanmarcus posted above about trying to build your own BH Crack, MassDrop CTH and Magni3, all are solid choices.


----------



## Paladin79

I have a UD-301 and it is a good solid performer but I prefer the Topping DX-7 dac/amp with a few more features and balanced output. I have run each into a Crack.


----------



## R-Oak

thank you all, i'm pretty sure i'm just going to have to wait 6months for the crack to go on sale, 
as far as the DAC goes, i dont know much myself, but most say that the sound doesnt do a big difference, that anyone of the cheap options are great
schiit uber / topping d30 / and a few others in that 100$ USD bracket 
i dont plan on spending anymore than a 100$ on a DAC, and thruth be told, i might try to run my amp dirrectly from my sound card before deciding to upgrade ( having said that, i will run away and hide) 
sadly the crack + 6xx is already quite a sum for me


----------



## Paladin79

One of my favorite solid state amps is a DIY build ($100 in parts) but you only get a schematic and Bom list, and circuit board. It is not an easy thing to start with like the Crack. They give you step by step instructions and photos.


----------



## attmci (Jun 5, 2018)

R-Oak said:


> thank you all, i'm pretty sure i'm just going to have to wait 6months for the crack to go on sale,
> as far as the DAC goes, i dont know much myself, but most say that the sound doesnt do a big difference, that anyone of the cheap options are great
> schiit uber / topping d30 / and a few others in that 100$ USD bracket
> i dont plan on spending anymore than a 100$ on a DAC, and thruth be told, i might try to run my amp dirrectly from my sound card before deciding to upgrade ( having said that, i will run away and hide)
> sadly the crack + 6xx is already quite a sum for me


Go to the trading thread and try a used one first.

If you use the laptop then you will amplify all the noise.....NOT recommended.


----------



## Allanmarcus

R-Oak said:


> thank you all, i'm pretty sure i'm just going to have to wait 6months for the crack to go on sale,
> as far as the DAC goes, i dont know much myself, but most say that the sound doesnt do a big difference, that anyone of the cheap options are great
> schiit uber / topping d30 / and a few others in that 100$ USD bracket
> i dont plan on spending anymore than a 100$ on a DAC, and thruth be told, i might try to run my amp dirrectly from my sound card before deciding to upgrade ( having said that, i will run away and hide)
> sadly the crack + 6xx is already quite a sum for me


If your motherboard has line out, that’s a great place to start with a crack. You next purchase should be tube upgrades, then a DAC.


----------



## attmci

R-Oak said:


> thank you all, i'm pretty sure i'm just going to have to wait 6months for the crack to go on sale,
> as far as the DAC goes, i dont know much myself, but most say that the sound doesnt do a big difference, that anyone of the cheap options are great
> schiit uber / topping d30 / and a few others in that 100$ USD bracket
> i dont plan on spending anymore than a 100$ on a DAC, and thruth be told, i might try to run my amp dirrectly from my sound card before deciding to upgrade ( having said that, i will run away and hide)
> sadly the crack + 6xx is already quite a sum for me


https://www.head-fi.org/threads/fs-bottlehead-crack-w-speedball-and-extras.881296/

Those tubes are great! Cv4003 5998


----------



## Paladin79

attmci said:


> https://www.head-fi.org/threads/fs-bottlehead-crack-w-speedball-and-extras.881296/
> 
> Those tubes are great! Cv4003 5998



That is not a bad deal considering the labor involved and the possible upgrades. A guy is selling basic builds on Ebay for around $650 each, he started with ten as I recall so they must be moving on occasion.


----------



## DavidA

R-Oak said:


> thank you all, i'm pretty sure i'm just going to have to wait 6months for the crack to go on sale,
> as far as the DAC goes, i dont know much myself, but most say that the sound doesnt do a big difference, that anyone of the cheap options are great
> schiit uber / topping d30 / and a few others in that 100$ USD bracket
> i dont plan on spending anymore than a 100$ on a DAC, and thruth be told, i might try to run my amp dirrectly from my sound card before deciding to upgrade ( having said that, i will run away and hide)
> sadly the crack + 6xx is already quite a sum for me



I think the CTH is a better amp (if price is really a concern) in that you don't really need to roll tubes like you will probably have to with the BH Crack since the stock tubes are a bit on the warmer side and to me make the HD650/6XX a bit overly warm and the bass does get muddy.  A TS-5998 / WE421A + Telefunken 12AU7 might add $150-200 to the price of the BH Crack so consider that in your price evaluation


----------



## bigfatpaulie

They said get, build and measure your Crack before buying new caps....







This is advice I did not take.


----------



## Kitchener

bigfatpaulie said:


> They said get, build and measure your Crack before buying new caps....
> 
> 
> 
> ...



Look at it like this:
If you can't fit the new caps in the old base, it's it but a golden opportunity to make your own custom base!
To paraphrase Johnny Cochran, "_if the cap don't fit, you must not quit_"...errr


----------



## JamieMcC

bigfatpaulie said:


> They said get, build and measure your Crack before buying new caps....
> 
> 
> 
> ...



lol 

Paul your going to have to get creative, looks like a lot of fun.


----------



## bigfatpaulie

Kitchener said:


> Look at it like this:
> If you can't fit the new caps in the old base, it's it but a golden opportunity to make your own custom base!
> To paraphrase Johnny Cochran, "_if the cap don't fit, you must not quit_"...errr



HAHA!  Pretty sure sure that that is an EXACT quote.  



JamieMcC said:


> lol
> 
> Paul your going to have to get creative, looks like a lot of fun.



I think so...  I didn't realize any of them were as big as they are.  Thank you again for all your guidance and help.  I also have a CX-7 on hand, just no Crack as of yet.


----------



## Paladin79

I cannot recall if Bottlehead will sell them separately but since I used other materials for my cabinets, I stacked two of their basic cabinets on top of one another for one build. With enough work, the seam can be concealed and you would have plenty of room for the larger caps. Maybe someone on here even has an extra cabinet you can get cheaply.


----------



## bigfatpaulie

Yeah, BH does sell them.  Having said that, I'm not keen on a tall Crack.  I'll find a way to make them fit.  It'll be fiiiiiiiiiiiiiiiiiiiine (famous last words).


----------



## Paladin79 (Jun 6, 2018)

LOL ok good luck with that, I had to make mine taller since I did not like the idea of pots, jacks, switch, or meters on the top on the top of mine and I had seen plenty with caps that were a struggle to fit inside the standard case. I can also recall someone saying that was one thing they always wanted, a larger case. My son wanted black piano finish so I was basically spraying multiple coats of lacquer on wood so it was not a good spot for expensive hardwood.

My builds are not for everyone by any means, I like to be challenged.


----------



## Th3Drizzl3

bigfatpaulie said:


> So....  Anyone else buy yet another Crack during the last sale?


I bought two more. i actually passed my crack/speedball on to my nephew to get him started down the long highway that is this hobby hahaha, and i ended up missing it. i do plan to order a mainline at some point because i just want to see how much better it is / how good the crack can be with upgrades. one im going to actually use in my back garage office where i do my soldering and building of anything like that. i am going to do a very odd hidden type of housing for that one the other i plan to match the (if i have enough left) of some maple with resin i made that i used on a few shaving brushes and keep it in the living room. now that i dont have any kids that are to young i can have stuff like that out without the fear of it seeing any accidents. plans can always change in this hobby though lol


----------



## Quadfather

I am running an RCA 6080 and an RCA 12AU7A with HD650s.  Sounds "okay."  Just ordered Tung Sol 5998 and Mullard CV4003.  I hope this gives me the improvement I'm looking for.


----------



## JamieMcC

Th3Drizzl3 said:


> i plan to match the (if i have enough left) of some maple with resin i made that i used on a few shaving brushes and keep it in the living room.



A resin wood enclosure has been one of the things I've been wanting to try for a little while now, I have some experience with casting myself and have been looking for the right piece of wood to use to achieve the look I am after for a while now. Probably cast a large block and then cut it into strips and glue up similar to the standard enclosure then sand and polish to get the finish.  

Best of luck it should be an interesting project.


----------



## Th3Drizzl3

thanks! thats actually what i did is cast a larger rectangle and then cut it down into "slices" and then ill polish it all once assembled. its not really hard honestly to work with. once they get here ill get started and update.


----------



## Quadfather

Jimbo24 said:


> So I had another listening session tonight with my Tung Sol 5998's with the stock tube. I want to take back what I said about it sounding flat. The instrument separation and 3d imaging is all there. I guess I needed a day to really relax my ears. I think yesterday I was stressed out and doing a bunch of other things while listening to music so that probably influenced my opinion on it. I find them really amazing. I was listening to Fleetwood Mac's self-titled album and everything just sounded so good. I also tried listening to it on a lower volume and it made much more of a difference. I can't wait to roll different tubes with the 12au7's. I'm really diggin the 5998's.


I have a Tung Sol 5998 and a Mullard CV4003 on the way.


----------



## Jimmy24

Quadfather said:


> I have a Tung Sol 5998 and a Mullard CV4003 on the way.



You will be pleased with the Tungsol 5998. I have not heard the Mullard but they're one of the best tubes you can get. 5998's are very natural sounding and clear. You'll love the way acoustic instruments sound with them.


----------



## Quadfather

Jimbo24 said:


> You will be pleased with the Tungsol 5998. I have not heard the Mullard but they're one of the best tubes you can get. 5998's are very natural sounding and clear. You'll love the way acoustic instruments sound with them.



This is the only hobby that makes me feel like a kid at Christmas!


----------



## Quadfather

What is better on Crack?  HD650, or Beyerdynamic T1?


----------



## bigfatpaulie

I think the 650 is the better headphone, personally, with or without a Crack.


----------



## Quadfather

bigfatpaulie said:


> I think the 650 is the better headphone, personally, with or without a Crack.



I really really like my HD650s. I have a Tung Sol 5998 and a mullard CV4003 on the way for my Bottlehead Crack


----------



## Allanmarcus

Quadfather said:


> What is better on Crack?  HD650, or Beyerdynamic T1?


There are various revisions of each of those headphones.  The 650is warmer, and livelier tubes help with the pairing.  The older T1 is bright, so warmer tubes are pair best.  Recent versions of both headphones have moved to balance their sound signatures, so tubes matter a little less, but are still important. If you prefer a more “fun”sounds, the T1is probably better, if you prefer a mellower, laid back sound, the HD650is probably better. That said, the T1 gen 2 isn’t nearly as bright as the gen 1.


----------



## JamieMcC (Jun 11, 2018)

Quadfather said:


> What is better on Crack?  HD650, or Beyerdynamic T1?



If your just going to run a stock Crack the HD650 would be good choice as on a stock Crack the T1 can sound a little lean and anaemic.

If your planning on modding your Crack then go for the T1 I thought they scaled better than the HD650 by some margin. Fitting a couple of inexpensive teflons bypasses to the output caps works wonders with the T1, I would go so far as to say the T1 on a modded Crack sounds like a different headphone with a fuller, richer and a more refined, smoother top end (teflons) than out of a stock Crack. 

Its a cracking combo imho


----------



## Quadfather

JamieMcC said:


> If your just going to run a stock Crack the HD650 would be good choice as on a stock Crack the T1 can sound a little lean and anaemic.
> 
> If your planning on modding your Crack then go for the T1 I thought they scaled better than the HD650 by some margin. Fitting a couple of inexpensive teflons bypasses to the output caps works wonders with the T1, I would go so far as to say the T1 on a modded Crack sounds like a different headphone with a fuller, richer and a more refined, smoother top end (teflons) than out of a stock Crack.
> 
> Its a cracking combo imho



The only modification is a Dale stepped attenuater.  I bought mine completed.


----------



## JamieMcC

bigfatpaulie said:


> They said get, build and measure your Crack before buying new caps....
> 
> 
> 
> ...



Paul I found a pic of a Crack showing the scale of the 400V Mundorfs your Clarity caps are only a few mm larger I think you should be ok maybe just some higher feet to get a little extra ground clearance. I remember using some 25mm rubber door stops on mine.


----------



## JamieMcC

Quadfather said:


> The only modification is a Dale stepped attenuater.  I bought mine completed.



The 650 is a safe bet if your not looking to do any modding yourself. It is a legendary headphone combo after all...


----------



## Paladin79

The 650 is my favorite even with modded Cracks I have built. I also use some heavily modded Beyerdynamics with a Crack I kept and I always go back to 650's when doing any serious listening.


----------



## JamieMcC

Th3Drizzl3 said:


> thanks! thats actually what i did is cast a larger rectangle and then cut it down into "slices" and then ill polish it all once assembled. its not really hard honestly to work with. once they get here ill get started and update.



Please takes some pics of your progress its an unusual approach I am sure plenty would be intrigued to see. 

I had good results casting large blocks 400mm x 150mm x 150mm of resin in moulds made out of HDPE plastic which releases easily (I used the white plastic hdpe cutting boards which work out a lot less expensive than buying it in sheet form).


----------



## Paladin79

I am always fascinated by your builds Jamie, I may be using a similar design that you used on some Amp camp amps, I have large heat sinks on the way out of China and once those hit I will probably start shopping for either burled walnut or burled maple for the tops and fronts.


----------



## bigfatpaulie

So you said.


JamieMcC said:


> Paul I found a pic of a Crack showing the scale of the 400V Mundorfs your Clarity caps are only a few mm larger I think you should be ok maybe just some higher feet to get a little extra ground clearance. I remember using some 25mm rubber door stops on mine.



Thanks!  I used to have the 400v in my last one.  I feel like the Clarity caps are bigger, however.  That's just from memory, not measuring so I could be wrong.  Time will tell I supposed.


----------



## R-Oak

the skill level displayed in a few of those crack's build on this thread is really inspiring, 
i was wondering: 
what are the *few upgrades* that people tend to do the *most??*, (i'm guessing either because they are easy to implement, cheap and does a difference)

i have seen alot of the velvet blue volume pot


----------



## Paladin79

Rolling tubes is one upgrade of course, lots of people do replace the pots with Alps blue velvet.
 Most of my changes were a bit radical and expensive to talk about as common upgrades so I will defer to others to talk about caps.


----------



## Allanmarcus

R-Oak said:


> the skill level displayed in a few of those crack's build on this thread is really inspiring,
> i was wondering:
> what are the *few upgrades* that people tend to do the *most??*, (i'm guessing either because they are easy to implement, cheap and does a difference)
> 
> i have seen alot of the velvet blue volume pot


Most popular, and effective, is tube rolling.  Until you have tubes you really like, there isn’t much of a point in changing anything else.  In terms of effect on sounds, tubes have an enormous effect compared to any other change.

The next is probably to pot.  The blue velvet or other pots give better balance at low volumes, and more even co tell of the volume at moderate volumes.

A choke is common for the vest mod, and more and more, the rectifier mod.  They are relatively easy.

Finally, caps. 

A few folks will “upgrade”the rca and trs jacks,  it that is really cosmetic also, a few will use difference tube sockets. 

Biggest bang for buck for sound is tubes.  All other mods are pretty much for fun and will have a fraction of sound impact as the tubes.


----------



## Kitchener

R-Oak said:


> the skill level displayed in a few of those crack's build on this thread is really inspiring,
> i was wondering:
> what are the *few upgrades* that people tend to do the *most??*, (i'm guessing either because they are easy to implement, cheap and does a difference)
> 
> i have seen alot of the velvet blue volume pot



Only mod I can recommend is the Speedball.
I’ve done Mundorf caps, choke, TKD pot and power bypass cap. And I can’t say any of them made a noticeable difference.
-then again, I can’t tell a Mullard from a Gold Lion from a Clear Top so what do I know?


----------



## Paladin79

You are honest in your appraisal of changes.

As far as microphonics I have added a copper top, front, and back plates to mine and the sheer weight of the amp along with one inch thick quartered oak makes mine very very stable and not susceptible to vibrations but it is not something i would recommend to others. I also like single gang pots but that is a personal preference. I did locate some made by Alps that are amazing but you have to have room for them, and know where to find them.


----------



## Kitchener

I can only tell what I hear 

I must point out that I’m not dismissing other mods. Some people have sharper ears that others.
And, I did all mods at once, not taking the time to appreciate each one, so there’s that.
The best way to find out is to try for yourself, sadly!


----------



## Paladin79

I did most all mods with a stock Crack next to the one being modified so I could listen and test each as I went along but I knew I would be starting with two.  It is hard for me to say ok I made a bunch of changes and I "remember" what the Crack sounded like before I changed things lol. It is not something for everyone but I like to be able to readily switch between amps, dacs, headphones, solid state, tubes, balanced, unbalanced and even headphone cables and try different combinations to achieve the sound I like. I still go back to the Crack though just for the tube sound.


----------



## Kitchener

I wish I could have done that!
I wasn’t in a hurry exactly, but once I start a project I devote as much as I can to getting it done.
When I was into DIY handwired mechanical keyboards, I worked on them in the garage until 6 in the morning before heading to work. -with a two year old in the house!
I guess it’s a form of mania.

I recently got a Stax earspeaker set and discovered I’m more of a neutral, analytical sort of guy! Still use the Crack for bedside listening though.


----------



## Paladin79

I believe you showed one of your keyboards before, it was amazing. Right now I am looking at old school typewriter keyboards with bluetooth for an Ipad Pro I just got but a lot of them are $400 up.

I am also building class A monoblock speaker amps and coaster hybrid headphone amps and am considering doing an Elekit preamp or Marantz M7.


----------



## Maxhawk

Another useful mod is the ability to change the bias resistor in the anode of the signal tube to optimize the current for other tube types such as the E80CC and 12BH7. I used to offer a PCB with a switch that allowed easy switch of this resistor. I currently have no more boards but would be willing to get more if there's enough interest.


----------



## bloodhawk

Maxhawk said:


> Another useful mod is the ability to change the bias resistor in the anode of the signal tube to optimize the current for other tube types such as the E80CC and 12BH7. I used to offer a PCB with a switch that allowed easy switch of this resistor. I currently have no more boards but would be willing to get more if there's enough interest.



This is how @Maxhawk 's awesome PCB's look in my crack - https://imgur.com/a/g3zkf4e

Im overhauling things today and moving everything to a 10"x10" Panel, it will look even better on that.


----------



## Paladin79

Very nice and additions like that are one of the reasons I went with a larger cabinet to begin with. Of course I used VU meters and their circuit board and dual pots so my builds would have been tough to do in a standard box no matter what. I did finally use a 12 by 12 inch top copper plate but with all the changes I made there, I hesitate to call it a Crack amp. A few components were recognizable but not many.


----------



## attmci (Jun 11, 2018)

Quadfather said:


> I have a Tung Sol 5998 and a Mullard CV4003 on the way.


You need to try a smoke glass TS 12au7 and a 7316 then stop driver tube rolling on the Crack. They are working very well with your 5998. GEC or 421 sounds better, but they are overkill for a Crack unless you plan to move to a better amp later.

These are fake:

https://www.ebay.com/itm/Quad-Vinta...332918&hash=item5d7bacafb9:g:nFUAAOSw9mpZ6Zos


----------



## FunyunBreath

attmci said:


> You need to try a smoke glass TS 12au7 and a 7316 then stop driver tube rolling on the Crack. They are working very well with your 5998. GEC or 421 sounds better, but they are overkill for a Crack unless you plan to move to a better amp later.



+1 on the 7316 being the end of the road for driver tube rolling


----------



## Quadfather

attmci said:


> You need to try a smoke glass TS 12au7 and a 7316 then stop driver tube rolling on the Crack. They are working very well with your 5998. GEC or 421 sounds better, but they are overkill for a Crack unless you plan to move to a better amp later.
> 
> These are fake:
> 
> https://www.ebay.com/itm/Quad-Vinta...332918&hash=item5d7bacafb9:g:nFUAAOSw9mpZ6Zos



What is the next step up from the Crack?


----------



## Allanmarcus

Quadfather said:


> What is the next step up from the Crack?


S.e.x., cracka twoa, then mainline.


----------



## Kitchener

Quadfather said:


> What is the next step up from the Crack?



Consumer debt.


----------



## Quadfather

Kitchener said:


> Consumer debt.



5 pairs of headphones, 3 digital audio players, and a tube amp. I am already there LOL


----------



## FunyunBreath

Lol, the key I think is selling off the stuff you don't need 

As soon as I finish my Mainline build the Crack is going to a new home haha.


----------



## Kitchener

Yeah, I think most of us are there! 
Right now I’m down to two “serious listening” headphone systems:
Crack + HD6XX (bedside)
STAX SRM-313 + Lambda Pro + Topping D30 DAC(office)

One Sennheiser Momentum On Ear Wireless for on-the-go listening.

One Beyerdynamic DT770 Pro for PlayStation/computer games/videos.

Can’t really see myself cutting down here.
Better pay of my debt and save up for whatever comes


----------



## attmci

Quadfather said:


> What is the next step up from the Crack?


Depends on what is your life after the hd-650/800  (i.e. LCDs etc). And don't forget the DAC.


----------



## Quadfather

attmci said:


> Depends on what is your life after the hd-650/800  (i.e. LCDs etc). And don't forget the DAC.



Right now, I am using an Audioquest Big Sur to hook up my DAPs.


----------



## DavidA

Kitchener said:


> Yeah, I think most of us are there!
> Right now I’m down to two “serious listening” headphone systems:
> Crack + HD6XX (bedside)
> STAX SRM-313 + Lambda Pro + Topping D30 DAC(office)
> ...


A lot or restraint on your part, I wish I was even half way there as you can see from the picture below:


Its an older picture and some of the headphones have changed but the quantity is still the same, or might have gone up, LOL.


----------



## bloodhawk

The 10"x10" Panel came in-


----------



## Paladin79

Plenty of space, very nice.


----------



## Th3Drizzl3

That looks awesome. hmmmm. lol


----------



## ALL212 (Jun 12, 2018)

Confessions of a Crack addict...

My last post (from what I can find) was back in 2013.  Since then I've built a stock Crack that didn't stay stock but got sold and I kept what I refer to as the BAC or Big A$$ Crack - the plate above reminded me of it.  The goal was to create enough space with a custom made plate to do all of the mods I wanted to do without trying to cram them all in that small stock area.  In a way I cheated a bit as I work for a company that has a sheet laser and I have friends in the department that programs the laser.  I designed the layout and then passed it to them.

The goal was to get the standard crack kit and the speedball installed with all of the goodies.  Goodies included the upgraded diodes, upgraded PS caps including one full film cap, PS inductor, film caps tipping any electrolytic caps, film output caps, 6SN7 instead of 12UA7 socket and upgraded volume pot.    I wanted the design to keep the on/off switch at the front and keep the volume and headphone jack at the front.  Mogami W2534 wire in the signal path if possible.

Once done I also tipped the output film caps with the MX series of Clarity Cap (base caps are PX Clarity caps).  I added resistors to the volume knob as I thought the volume came up too fast.  You'll also notice damping material on the plate as I thought the slight clicks of the volume Pot were lessened by that.

Base Layout:  I left the first two caps sticking up through the chassis.





Top plate done minus tubes:  Just some bling around the headphone jack.





Done except for the extra resistors at the volume:





Volume Pot wiring:
	

	
	
		
		

		
		
	


	




Next to his cousin - the modified but stock plate Crack:  Socket adapter on the stock plate allows use of the 6SN7 tube.





The only mistake I made was after I adjusted the distance of the speedball from the transformer I didn't remeasure the distance between the holes mounting the speedball.  So it's just mounted with one screw.  As light as it is this doesn't cause any issues.

A year or two ago I built the Mainline and this past winter built the Crack-a-two-a.  Folks - Mainline wins, I don't care what components you put in the Crack or derivatives thereof.  However, this amp rocks! 

Aaron


----------



## Kitchener

So I'm considering, _maybe_, down the line trying to sell my Crack (Ironclad/Brass Shithouse, has pictures) to finance a Bottlehead S.E.X. kit.
I'm not quite there yet, and maybe I'll never get there but I'd like some help determining how much I could realistically ask for it.

It has the following internal mods:
Speedball - $125
Mundorf Mcap MKP (100uF 250V) - $95
Hammond 157M choke - $30
TKD 2C-601 pot - $40
JB JFX, PSU bypass cap (2.2uF 250V) - $1-2

Cosmetics
New knob - $15
Brass Corners - $78.41 (I _know_, jesus what was I thinking!?)
Clear poly coat

Bunch of tubes
12AU7 type:
Mullards x7
RCA Clear Tops x3
Genalex Gold Lion x1 

6080 type:
Mullard x1
Svetlana 6N13S x2
Philips x1

It was wired and soldered to the best of my abilities.
My philosophy was pretty much "this should be able to fall down the stairs and still work" (_It wont_, of course, but I tried).
I'm particularly pleased with how I suspended the output caps from the top plate; metal clamps, sturdy, easy to either remove or replace caps.
The wiring from the RCA inputs to the pot could probably use a do-over, but they're good and solid.

Cracks pop up frequently on the marketplace here, some of the really unique ones go for $6-700 maybe more, while the stock variants go for about $400 it seems.
Let's say I could sell the lot, what would anyone be willing to pay, what would a reasonable asking price be?


----------



## Paladin79

I cannot swear it is true but I have been told that on DIY amps you can only base them on kit price to sell them on Headfi. Now on Ebay there are stock cracks for $650 up. I have turned down a private offer of much more for mine. Also here, everyone knows you can buy a kit on sale without speedball for $200 roughly so personally I would say post in on Ebay next to stock Cracks and you should be able to fetch considerably more if the right buyer comes along.


----------



## Kitchener

Ideally I'd sell it on our "Norwegian eBay" called Finn.no, that way I can maybe even hand it over in person and be "on call" for tech support.
But I'd definitely "cast a wide net" and try eBay.


----------



## Paladin79

I think that is wise but I am certainly not an expert on policy here so maybe someone else has some thoughts there.

My basic build was six hours but I spent a LOT of time on cabinet and copper plates and components and tubes and changing the build. The fact that less probably exist in Norway should help you a lot I would think.


----------



## Allanmarcus

here be the rules:

https://www.head-fi.org/articles/buy-sell-trade-rules.13274/
*Likewise, DIY items cannot be sold at greater than the cost of parts (and shipping), as doing so would make the DIY'er a Member of the Trade and subject to the rules as stated in the Terms of Service.*


----------



## Kitchener

Great, thanks!


----------



## Paladin79

Well stated Allan, personally I would like to be paid for the pain and suffering I incurred while cutting square holes in 1/8 inch copper plate but that amount would be astronomical so I best just keep the amp.


----------



## bloodhawk

Allanmarcus said:


> here be the rules:
> 
> https://www.head-fi.org/articles/buy-sell-trade-rules.13274/
> *Likewise, DIY items cannot be sold at greater than the cost of parts (and shipping), as doing so would make the DIY'er a Member of the Trade and subject to the rules as stated in the Terms of Service.*



Going by that Logic, everyone selling their BH Cracks for $200+ is breaking the rules.


----------



## Paladin79

Not necessarily, buy one when not on sale with Speedball and they could be $375 or more.


----------



## bloodhawk

Paladin79 said:


> Not necessarily, buy one when not on sale with Speedball and they could be $375 or more.



Totally agreed, but my statement above was based on the actual cost of material.


----------



## Kitchener

I have a feeling that people on here are the sort who have the skills and confidence to actually build amp kits, and therefore might not be interested in paying extra unless the amp is truly unique in some way.


----------



## Paladin79

Very true. One guy on ebay started with about ten and is down to four or so now at $650 or so, but he has had them up for sale for a long time. Shipping to Norway has to be expensive, I know sending a small cable to the Netherlands was $35 postal.  A lot of the Bottlehead experience is the fun of the build but not everyone wants that.


----------



## bigfatpaulie

I bet there are mods here who don't know that rule...  I think if you listed it for what you want, it's fine.  I think that rule is to prevent someone from building a business on HF's sales corner, not selling a one off amp that was for your own private use.


----------



## bloodhawk

bigfatpaulie said:


> I bet there are mods here who don't know that rule...  I think if you listed it for what you want, it's fine.  I think that rule is to prevent someone from building a business on HF's sales corner, not selling a one off amp that was for your own private use.



Definitely makes sense.


----------



## Quadfather

I have not yet received the Tung Sol 5998. However, I received the Mullard CV4003. Currently I am running it with an RCA 6080 power tube. I really love the fact that this tube has made the treble and cymbals sound much more realistic and clear. That is the first thing I notice.


----------



## Allanmarcus

bigfatpaulie said:


> I bet there are mods here who don't know that rule...  I think if you listed it for what you want, it's fine.  I think that rule is to prevent someone from building a business on HF's sales corner, not selling a one off amp that was for your own private use.


The mods here are very strict. I posted an HD600 and asked for PayPal fees or gift, and they edited the part about about fees out, and sent me a polite note saying why, and that I might want to update the posting. Lots of folks break the rules, and the mods don't monitor every post. If a person uses the "report" link, the mod will get involved.

I sold a crack here that netting me $400, about what I paid. It was not purchased on sale, and had a few upgrades that I added. The buyer was not the type of person to build there own, so he was very happy. I agree that the intent of the rule is stop folks from using HF as a business outlet, and not paying for the MOT badge.


----------



## bloodhawk (Jun 13, 2018)

And done - https://imgur.com/a/fLWdBZf

































The saddest thing is that I'm leaving on an extended work trip in 2 weeks, so i gotta let this baby go 

Also wish i had the time to figure out where is noise in the left channel when using 5687 tubes.. ah well. At least everything else is waaay cleaner than my previous build.


----------



## GU1DO

Paladin79 said:


> Well stated Allan, personally I would like to be paid for the pain and suffering I incurred while cutting square holes in 1/8 inch copper plate but that amount would be astronomical so I best just keep the amp.


i feel you are being sarcastic ,, you charge 125$ for minor fixes + a box  (and shipping is not included)
650$ for fully assembled crack w/Speedball (kit cost 422$) is totally reasonable with your price rate!


----------



## Quadfather

For anybody that gets weird static on their Bottlehead Crack, which is otherwise dead silent, get your cell phone way the hell away from it. I found out that is what's causing it.


----------



## adydula

I agree with your Mainline wins!

I have done many listening sessions between my Crack and new mainline...hands down the Mainline is really special....it always makes
me smile....the overall presentation is just wonderful....

Alex


----------



## Paladin79

GU1DO said:


> i feel you are being sarcastic ,, you charge 125$ for minor fixes + a box  (and shipping is not included)
> 650$ for fully assembled crack w/Speedball (kit cost 422$) is totally reasonable with your price rate!



I am not sure why you used my quote with your message. I merely said i spent more time on cosmetics and it is not something I can recover. I was joking but I hope that was obvious.  Earlier we were talking about Cracks on sale without speedball being $200.  I did mention I believed you were supposed to sell DIY products at a certain price and Allan quoted the actual rule here. That is pretty much the end of the story.


----------



## Astral Abyss

bloodhawk said:


> And done - https://imgur.com/a/fLWdBZf
> 
> 
> The saddest thing is that I'm leaving on an extended work trip in 2 weeks, so i gotta let this baby go
> ...



That is a beast.  I really like the way it turned out.


----------



## ALL212

bloodhawk said:


> And done - https://imgur.com/a/fLWdBZf
> The saddest thing is that I'm leaving on an extended work trip in 2 weeks, so i gotta let this baby go
> Also wish i had the time to figure out where is noise in the left channel when using 5687 tubes.. ah well. At least everything else is waaay cleaner than my previous build.



Wow!  I'm coming in late to this party - what's with the switchy thingy boards?  Tell me more - dual inductors?  I've know what you did with the white and gold caps - what's with the blue?

Very cool!


----------



## bloodhawk (Jun 14, 2018)

Astral Abyss said:


> That is a beast.  I really like the way it turned out.



Thanks ! Its always fun tinkering around.



ALL212 said:


> Wow!  I'm coming in late to this party - what's with the switchy thingy boards?  Tell me more - dual inductors?  I've know what you did with the white and gold caps - what's with the blue?
> 
> Very cool!



The Switch boards are PCB's that @Maxhawk made to enable the use of a wider range of driver tubes. Yeah the chokes are mainly replace the 270Ohm wirewound resistors.  And that blue cap is basically bypassing the last PSU cap  (This isn't really necessary, and contrary to popular belief, it doesn't really do much for sonic improvements. Mainly helps with clearing out the background a bit)


----------



## GU1DO

Paladin79 said:


> I am not sure why you used my quote with your message. I merely said i spent more time on cosmetics and it is not something I can recover. I was joking but I hope that was obvious.  Earlier we were talking about Cracks on sale without speedball being $200.  I did mention I believed you were supposed to sell DIY products at a certain price and Allan quoted the actual rule here. That is pretty much the end of the story.


sorry but your statement was misleading because all current ebay listings are for crack w/Speedball and i thought your are disagreeing with these high prices by your jock, thats all .


----------



## bigfatpaulie

bloodhawk said:


> ...



That's AMAZING!  Well done, Sir!


----------



## Paladin79 (Jun 14, 2018)

sorry but your statement was misleading because all current ebay listings are for crack w/Speedball and i thought your are disagreeing with these high prices by your jock, thats all .

I know what the listings are, someone else kept using the figure $200 but I did not want to argue it, that is a sale price without speedball, shipping, or badge.

I was just emphasizing how much trouble I went through with part of my build. I have many years in electronics so that portion of the build was fairly easy for me but I challenged myself to bring about a lot of changes if I built a Crack.
On here there are rules about how you sell DIY product, Allan quoted those. Previously I just said that if a base crack with speedball went for $650 on Ebay, then the gentleman who put a lot of upgrades into his should be able to get more.  I hope this makes sense to you now.

 I have purchased four and my builds are unique but not for everyone. I put so much work into the one I kept, I doubt I will sell it. The photo is my first build and the one I kept.


----------



## Kitchener

Yowza! Sweet build there, Bloodhawk!


----------



## Kitchener

Paladin79 said:


> sorry but your statement was misleading because all current ebay listings are for crack w/Speedball and i thought your are disagreeing with these high prices by your jock, thats all .
> 
> I know what the listings are, someone else kept using the figure $200 but I did not want to argue it, that is a sales price without speedball, shipping, or badge.
> 
> ...



Unique builds like yours should definitely go for a considerable sum.


----------



## Paladin79

I gave one away, asked kit cost for another, and won a bet by building one but it had nothing to do with selling on Headfi. My current builds are all Class A solid state and some round hybrid amps. I will try to mount a round amp inside a scotch bottle. I like a challenge, this 8 ball will be easy in comparison.


----------



## bloodhawk

bigfatpaulie said:


> That's AMAZING!  Well done, Sir!





Kitchener said:


> Yowza! Sweet build there, Bloodhawk!



Thanks guys!

I just really wish i had to time to make the aesthetics as unique as @Paladin79 does with his builds. That would have made it truly stand out!


----------



## Paladin79

You are most kind Bloodhawk, if you ever want to add patina to copper I can teach you that pretty easily. The process takes 24 hours or less but actual work time might be ten minutes or less.
 Here is a lighter blue patina I added to another copper plate. You can go more towards dark blue or green depending on the salt and liquid combination.


----------



## bloodhawk

Paladin79 said:


> You are most kind Bloodhawk, if you ever want to add patina to copper I can teach you that pretty easily. The process takes 24 hours or less but actual work time might be ten minutes or less. Here is a lighter blue patina I added to another copper plate. You can go more towards dark blue or green depending on the salt and liquid combination.



Damn that looks awesome! 

I might do a LTP build for my dad in a few months, once im settled down again and will definitely send a few questions your way


----------



## Paladin79

Not a problem, here are a couple other things I am playing around with.


----------



## Allanmarcus

Paladin79 said:


> I gave one away, asked kit cost for another, and won a bet by building one but it had nothing to do with selling on Headfi. My current builds are all Class A solid state and some round hybrid amps. I will try to mount a round amp inside a scotch bottle. I like a challenge, this 8 ball will be easy in comparison.


A spherical amp has the potential to be "rolled off". Could be a problem


----------



## Paladin79

Unless the bottom is flat, which it is. I was in a hurry and just said 8 ball, that is a magic 8 ball child's toy, cost $6 with shipping from Amazon Prime. The board fits in it like it was made for it, dumb luck.

It took me over an hour to get it open. Picture a knife blade and large rubber mallet. They are well sealed to protect small children I would think.


----------



## Quadfather (Jun 14, 2018)

Loving the CV4003 so far.  And the first picture is my glowing, hot crack! LOL. Bottlehead makes it so easy to sound dirty on the internet.


----------



## bigfatpaulie

Be kind, resize


----------



## Quadfather

bigfatpaulie said:


> Be kind, resize



I just went in and save them as thumbnails. Does that look any better?


----------



## bigfatpaulie

Yup!

Glad you are loving the amp and glass!


----------



## Quadfather (Jun 14, 2018)

bigfatpaulie said:


> Yup!
> 
> Glad you are loving the amp and glass!



My 5998 hasn't even got to me in the mail, so it's only going to get better.  I was close to selling it, and then I thought hey let's try changing the tubes and it may sound more to my liking... So glad I changed some tubes out.  I really didn't think an output tube would have such a big impact.


----------



## Quadfather

OH, HELL YEAH!!!!!!!!!!!!


----------



## bloodhawk

Quadfather said:


> OH, HELL YEAH!!!!!!!!!!!!



Isn't it a massive step up form the standard
power tubes ? 

I love the 5998/421A and the 7236's in my amps and love chnag8ng between them every now and then. 

But the 5998's are the most balanced of them all.


----------



## Quadfather (Jun 15, 2018)

bloodhawk said:


> Isn't it a massive step up form the standard
> power tubes ?
> 
> I love the 5998/421A and the 7236's in my amps and love chnag8ng between them every now and then.
> ...



So far I am in love with the 5998 / 4003 combination. Sounds very holographic and gives it that gooey tube sound. The 4003 refines the upper end and of course the mid-range is liquid and holographic as well.  I may order back up tubes once I can afford it to keep in the safe.


----------



## Jimmy24

Quadfather said:


> OH, HELL YEAH!!!!!!!!!!!!



Looks amazing  Nice set up you got there


----------



## Quadfather

Jimbo24 said:


> Looks amazing  Nice set up you got there




Thanks. I am glad I took the OTL plunge.


----------



## Tom-s

When flat on a surface, for a Crack without feet, ventilation for its internals is minimal.
Especially when tube rolling there's more thermal stress on some components compared to stock.
From my own experience, sufficient airflow becomes more important the more crowded you get your Crack from various mods.
To have lots of fun with your Crack for a long time, it might be a good idea to get it on feet.
Let it breathe, and enjoy it!


----------



## attmci

Paladin79 said:


> You are most kind Bloodhawk, if you ever want to add patina to copper I can teach you that pretty easily. The process takes 24 hours or less but actual work time might be ten minutes or less. Here is a lighter blue patina I added to another copper plate. You can go more towards dark blue or green depending on the salt and liquid combination.



Be careful of playing with copper. You may generate toxic materials.


----------



## Paladin79 (Jun 16, 2018)

That is one of the reasons I offered to teach.

I either do this outdoors or in a shed on the back of my property in the winter. If I ever have questions I turn to my daughter-in-law. Her PhD is in chemistry.  I am also used to dealing with ROHS compliance, etc.; even when soldering with 60/40 solder I warn employees that lead is a cumulative poison.


----------



## attmci

Paladin79 said:


> That is one of the reasons I offered to teach.
> 
> I either do this outdoors or in a shed on the back of my property in the winter. If I ever have questions I turn to my daughter-in-law. Her PhD is in chemistry.  I am also used to dealing with ROHS compliance, etc.; even when soldering with 60/40 solder I warn employees that lead is a cumulative poison.


Thanks for the comments. It's so beautiful.


----------



## Quadfather (Jun 24, 2018)

I really do not understand tubes and electronics. I have had more listening time on this tube amp with the new Tung Sol 5998 and Mullard CV4003 tubes, and all of the sudden the bass is starting to really slam hard and go way lower. I like it.


----------



## attmci

Quadfather said:


> I really do not understand tubes and electronics. I have had more listening time on this tube amp with the new Tung Sol 5998 and Mullard CV4003 tubes, and all of the sudden the bass is starting to really slam hard and go way lower. I like it.



You words worth much more than other expert's on this forum.  

Congratulations!


----------



## Quadfather (Jun 24, 2018)

attmci said:


> You words worth much more than other expert's on this forum.
> 
> Congratulations!



Thank you. One thing I never do on here, is pretend to be an expert. When I do not understand something or how it works, I am the first to admit it. I also realize everybody hears differently, so I never criticize others for their opinions of equipment.  This is the most rewarding hobby I've ever been a part of.


----------



## Rhamnetin

Quadfather said:


> I really do not understand tubes and electronics. I have had more listening time on this tube amp with the new Tung Sol 5998 and Mullard CV4003 tubes, and all of the sudden the bass is starting to really slam hard and go way lower. I like it.



Very nice. I plan to compare the Mullard CV4003 to the Amperex Bugle Boy in this amp. Won't bother with anything else and the only power tube I will be using is a NOS Tung Sol 5998.


----------



## Quadfather

Rhamnetin said:


> Very nice. I plan to compare the Mullard CV4003 to the Amperex Bugle Boy in this amp. Won't bother with anything else and the only power tube I will be using is a NOS Tung Sol 5998.



Be sure to let us know. Cheers


----------



## Mightygrey

Quadfather said:


> I really do not understand tubes and electronics. I have had more listening time on this tube amp with the new Tung Sol 5998 and Mullard CV4003 tubes, and all of the sudden the bass is starting to really slam hard and go way lower. I like it.


I finally bit the bullet and got myself a Tung Sol 5998 tube, paired with a Sylvania 6SN7 input tube. I should have gotten it months ago - the dynamics have certainly changed for the better - it's also dead-silent now compared to the noisy RCA 6AS7G's I took a punt on via eBay a while ago. It's perfection.

For science, I also tried using my Crack as a pre-amp with my two-channel power amp. I used a 6.3mm adapter to 2 x RCA, and fed the signal to the line-level inputs on my 250 WPC power amp. It was incredible.


----------



## Paladin79

I have used the Crack as a preamp as well with great results. I went so far as to install RCA outputs in a couple Cracks I built just for that purpose.


----------



## Mightygrey

Paladin79 said:


> I have used the Crack as a preamp as well with great results. I went so far as to install RCA outputs in a couple Cracks I built just for that purpose.


I'm not electrically-minded enough to understand the impact (if any?) that the Crack's relatively high output impedance may have on performance downstream when using as a pre-amp - is there anything to be mindful of?


----------



## Mightygrey

Paladin79 said:


> I have used the Crack as a preamp as well with great results. I went so far as to install RCA outputs in a couple Cracks I built just for that purpose.


Would that just involve linking the L/R wiring upstream from the headphone-out + a shared ground to 2 x RCA outputs? Do any resistors need to be added?


----------



## Paladin79

I have not added resistors and the rca females I used are just in parallel with the standard jack so it is similar to what someone else said about plugging in a quarter inch to dual rca's.


----------



## bigfatpaulie

So it begins....  Again.


----------



## Allanmarcus

Mightygrey said:


> I'm not electrically-minded enough to understand the impact (if any?) that the Crack's relatively high output impedance may have on performance downstream when using as a pre-amp - is there anything to be mindful of?



nope



Mightygrey said:


> Would that just involve linking the L/R wiring upstream from the headphone-out + a shared ground to 2 x RCA outputs? Do any resistors need to be added?



I've done it. Just add the RCA jacks and wire to the headphone out. One needs to have a plug in the headphone jack to keep the connection active, but other than that, nothing special.

Here's a cable I made that works well as a pre-out:





here's an old crack that I added RCA pre-outs. Unfortunately, I cannot find pics of the wiring, but it wasn't hard.


----------



## Paladin79 (Jul 6, 2018)

With names like the Crack, and Mainline I thought perhaps this 8-ball amp I just built might fit into the drug related theme. It is a hybrid DIY amp I built into a toy Magic 8 ball, the bottom is flat so it will sit on a desk. Remove the top and you have a headphone amplifier. I am also working toward mounting a few in tobacco tins, headphone racks, and even scotch bottles but I got an easy build out of the way first. Naturally I have built a few Crack amps but I am branching out a bit, hopefully it is not grossly off topic.


----------



## kevlar51

Just finished my Crack build yesterday—I’ll start the Speedball upgrade in another week or so after I’ve given the standard build a fair shake. Then on to tube rolling and then of course I’ll be all done

In the meantime I’m hoping someone can advise on my setup—currently I use HD650, fed by some Schiit products: Eitr>Mimby>Jotunheim

The Jot has the phono preamp onboard, and a modified AT LP-120 feeds into that (I’ve cut the preamp out of the turntable). 

The Jot also feeds into an old Onkyo receiver that powers some speakers for when I feel up to it. 

Currently the Jot’s controls switch nicely between all of these functions. But now I’ve added a Crack into the mix for different flavor. What are some opinions on a good setup? Am I selling myself short to use the Jot as a preamp to the Crack? I’m not sure I see a way around when I’m listening to vinyl, unless I buy a new separate phono preamp. 

Thanks for any thoughts.


----------



## Allanmarcus

kevlar51 said:


> Just finished my Crack build yesterday—I’ll start the Speedball upgrade in another week or so after I’ve given the standard build a fair shake. Then on to tube rolling and then of course I’ll be all done
> 
> In the meantime I’m hoping someone can advise on my setup—currently I use HD650, fed by some Schiit products: Eitr>Mimby>Jotunheim
> 
> ...


Sounds like a good set up. You can always spend more money for a very incremental improvement.


----------



## bigfatpaulie

I forgot how good the Crack is.  Holy smokes, talk about value!


----------



## Rhamnetin

bigfatpaulie said:


> I forgot how good the Crack is.  Holy smokes, talk about value!



Especially when you pay only $300 for a Crack 1.1 + Speedball.


----------



## Stillhart

So I've got an itch to build another DIY amp (I've built a Project Solstice before) and the one I want to build is rather complicated.  I thought I might start with a Crack and mess around with mods and stuff to build up a little more knowledge before tackling something more complex.

Some questions for you fine folks:  I haven't actually heard one before, I only know them by reputation.  The only high impedance cans I have at the moment are my trusty HD800.  How do they fare with the Crack?  By comparison, I'm currently driving them with a Liquid Carbon.

How often do they go on sale?  I've seen the $200 price mentioned in the last few pages, but it's nowhere near that right now.  Am I going to be waiting until Black Friday or is it more of a regular thing?

Can I use my tubes from the Solstice in the Crack?


----------



## Allanmarcus (Jul 12, 2018)

Stillhart said:


> So I've got an itch to build another DIY amp (I've built a Project Solstice before) and the one I want to build is rather complicated.  I thought I might start with a Crack and mess around with mods and stuff to build up a little more knowledge before tackling something more complex.
> 
> Some questions for you fine folks:  I haven't actually heard one before, I only know them by reputation.  The only high impedance cans I have at the moment are my trusty HD800.  How do they fare with the Crack?  By comparison, I'm currently driving them with a Liquid Carbon.
> 
> ...


Crack and HD800 with good tubes sound great. Good tubes are about a $100 or less a set, so not a big deal. With the stock tube the combo will sound good.
The crack goes on sale a couple of times a year, sometimes with the speedball upgrade. Subscribe to their newsletter to get notified. Hard to know when the next sale will be. From what I can tell last sales were:

May, 2018
Oct 2017
Mar 2017
Sep 2016
April 2019

So you can extrapolate from this data the next sale will likely be oct. Sometimes they lower the price, sometimes they include a free speedball.


----------



## bigfatpaulie

Hello all,

I built my new Crack (this is my second one and 3rd BH amp) and it worked perfectly.  Now I added in the Speedball - all the voltage checks passed, all the LED's light up but there is no sound on the right channel.  I also posted on the BH form.

I've checked continuity on all the paths.  I've flowed the solder on every connection on the SB boards and on the joints that I work on tonight.  I've switched L/R RCA cables, the side issue stays on the same side.  I've tested the headphones on a different amp and they work.

Added: I tested every transistor and diode.

Added: I've checked every resistor.

Added: I've rolled both tubes.

I should also not that the left channel sounds great.

Any thoughts?  Could it be a DOA part?  What am I missing?

Thanks for any advice.

-Paul


----------



## kevlar51

bigfatpaulie said:


> Hello all,
> 
> I built my new Crack (this is my second one and 3rd BH amp) and it worked perfectly.  Now I added in the Speedball - all the voltage checks passed, all the LED's light up but there is no sound on the right channel.  I also posted on the BH form.
> 
> ...




I had no sound in the right channel both after the Crack build and the Speedball build, measurements were fine on each.  For the Crack, resoldering the joints between and on the headphone jack and the volume attenuator did the trick (not sure which joint was ultimately the culprit).

For the Speedball, no resoldering was necessary, I found some bare wire touching where it shouldn't in the octal socket.  I believe it was a wire soldered to A7 pushed over and touching A8.  It's a cramped spot, but once I separated them, my issues were fixed. Initially after the Speedball install, I also had a hiss at the low end and the high end of the volume. Same fix took care of it.


----------



## kevlar51

Allanmarcus said:


> Sounds like a good set up. You can always spend more money for a very incremental improvement.



So far I'm not super thrilled with using the Jot as a preamp to the Crack. I'm getting extra hum and hiss that I don't get when I plug my mimby directly into the Crack (or mimby into the Jot when I listen through the Jot). I might just need to play around with the volume and see if there's a spot that works. It's already on low gain.


----------



## bigfatpaulie

kevlar51 said:


> I had no sound in the right channel both after the Crack build and the Speedball build, measurements were fine on each.  For the Crack, resoldering the joints between and on the headphone jack and the volume attenuator did the trick (not sure which joint was ultimately the culprit).
> 
> For the Speedball, no resoldering was necessary, I found some bare wire touching where it shouldn't in the octal socket.  I believe it was a wire soldered to A7 pushed over and touching A8.  It's a cramped spot, but once I separated them, my issues were fixed. Initially after the Speedball install, I also had a hiss at the low end and the high end of the volume. Same fix took care of it.



Thanks.  I just double checked both tube sockets, all clear.  

I reflowed all the joints in the right audio channel path as well. 

No dice.


----------



## Allanmarcus (Jul 12, 2018)

kevlar51 said:


> So far I'm not super thrilled with using the Jot as a preamp to the Crack. I'm getting extra hum and hiss that I don't get when I plug my mimby directly into the Crack (or mimby into the Jot when I listen through the Jot). I might just need to play around with the volume and see if there's a spot that works. It's already on low gain.


Looks like you have an opportunity to buy or build an RCA switch box!

Alternative, you can try simple RCA Y splitters and run the DAC output to both the Jot and the Crack.

I have some info on RCA switch boxes here:
https://sites.google.com/marcusfamily.info/diynotes/home/rca-switchbox


----------



## Allanmarcus

bigfatpaulie said:


> Thanks.  I just double checked both tube sockets, all clear.
> 
> I reflowed all the joints in the right audio channel path as well.
> 
> No dice.


When you added the first board of the speedball, did the crack work fine? That would help for you figure out if the issue is with the first board or the second board. Also, post lots of pictures of the boards and the wiring, including under the boards.


----------



## bigfatpaulie

Allanmarcus said:


> When you added the first board of the speedball, did the crack work fine? That would help for you figure out if the issue is with the first board or the second board. Also, post lots of pictures of the boards and the wiring, including under the boards.



It tested fine, but I didn't listen to it in that state...

Here are some photos.  Pardon the mess but everything has been either re-flowed or re-soldered 3 times now so, you know.

Please let me know if there something specific you want to see.


----------



## drtechno

Stillhart said:


> So I've got an itch to build another DIY amp (I've built a Project Solstice before) and the one I want to build is rather complicated.  I thought I might start with a Crack and mess around with mods and stuff to build up a little more knowledge before tackling something more complex.
> 
> Some questions for you fine folks:  I haven't actually heard one before, I only know them by reputation.  The only high impedance cans I have at the moment are my trusty HD800.  How do they fare with the Crack?  By comparison, I'm currently driving them with a Liquid Carbon.
> 
> ...


Just build it.  These are simple common tube circuits located in the RCA tube manuals. The only real expensive part would be the $35 transformer. Otherwise, you could build it  under $100 with the cheap parts I saw on the bottlehead site.


----------



## kevlar51

Allanmarcus said:


> Looks like you have an opportunity to buy or build an RCA switch box!
> 
> Alternative, you can try simple RCA Y splitters and run the DAC output to both the Jot and the Crack.
> 
> ...



I've got one already, but it's not hooked up yet. I've known for a while that I was going to need to put a switch between the Jot (preamp) and the Crack so that I could also have my PC hooked up to an old Onkyo receiver hooked to passive speakers.

So if I dump the Jot, I'll need to get another switch. And a phono preamp.


----------



## Jimmy24

bigfatpaulie said:


> Thanks.  I just double checked both tube sockets, all clear.
> 
> I reflowed all the joints in the right audio channel path as well.
> 
> No dice.



Make sure you post pics on the BH forum. They usually can pinpoint exactly what's wrong with your amp. The owners are quick to respond and can usually figure it out.


----------



## drtechno

redo these solder joints. wires should go around at least 1 1/2 times on eyelet terminals...


----------



## drtechno

drtechno said:


> redo these solder joints. wires should go around at least 1 1/2 times on eyelet terminals...


----------



## Stillhart

drtechno said:


> Just build it.  These are simple common tube circuits located in the RCA tube manuals. The only real expensive part would be the $35 transformer. Otherwise, you could build it  under $100 with the cheap parts I saw on the bottlehead site.


Interesting.  You're not the first to suggest hat the parts can be obtained for a lot less than the kit price.  At that price, it's a bit of a no-brainer.


----------



## Allanmarcus

bigfatpaulie said:


> Please let me know if there something specific you want to see.



So far what I see looks good, but since all the LED are lighting, I would check the jack, and make sure it's soldered well, and the wires that connect to it.

I never did the 1.5 wrap around wiring in the eyelets that @drtechno mentioned, but I did do a little curl, and then pliers to crimp the wires to the eyelet, then solder to hold in place.you can check continuity with power disconnected to verify the joints.

Also, walk through the manual again and verify each step. When I made my Mainline, I missed a step. I didn't catch it until I actually printed the manual, went through each step, and physically checked off the step in the printed manual. 

But for now, I would world backwards from the jack.


----------



## Allanmarcus

Stillhart said:


> Interesting.  You're not the first to suggest hat the parts can be obtained for a lot less than the kit price.  At that price, it's a bit of a no-brainer.


some of the magic of the crack is the transformer. It's a good transformer.

The larger magic of the crack is the instructions and support community. if you try to replicate the crack and build it yourself, you will need to seek support from other DIY communities. Many are absolutely fantastic.


----------



## drtechno

Stillhart said:


> Interesting.  You're not the first to suggest hat the parts can be obtained for a lot less than the kit price.  At that price, it's a bit of a no-brainer.


Well about 30 years ago, I used to teach people how to construct point to point, and those all look like the ones in the tube manuals. The only issue I see is he initially uses the wrong grid stops, that will cause problems, until you put a ccs on them (the magic speedball upgrade).


----------



## drtechno (Jul 12, 2018)

Allanmarcus said:


> some of the magic of the crack is the transformer. It's a good transformer.
> 
> The larger magic of the crack is the instructions and support community. if you try to replicate the crack and build it yourself, you will need to seek support from other DIY communities. Many are absolutely fantastic.


you always use a good transformer. Like the Hammond he is using.

btw, why would someone (like me) who repaired/restore antique radios for a couple of decades would need help with the simple designs that apparently, he put the wrong parts in the kit?

btw he doesn't have the simplest version of css, like using a preamp tube per channel, and use the heater of the preamp tube as the 6080/6as7 cathode resistor.


----------



## Allanmarcus

drtechno said:


> you always use a good transformer. Like the Hammond he is using.


I always use the transformer that comes with the Bottlehead kits, so yes, I used a good transformer.

I'm pretty sure the Crack does not use any transformer from hammond. From the BH forum and posted by a BH employee:


> There isn't any drop-in power transformer from Hammond that would work in the Crack.  The Crack power transformer is labelled with a rating for DC current from a voltage doubler, which is not how it's configured in the Crack.


----------



## bigfatpaulie

Thanks, @drtechno.  Done.  I've reflowed them all.  No change.


----------



## bigfatpaulie

Allanmarcus said:


> So far what I see looks good, but since all the LED are lighting, I would check the jack, and make sure it's soldered well, and the wires that connect to it.
> 
> I never did the 1.5 wrap around wiring in the eyelets that @drtechno mentioned, but I did do a little curl, and then pliers to crimp the wires to the eyelet, then solder to hold in place.you can check continuity with power disconnected to verify the joints.
> 
> ...



Thanks.  Yeah, I did what you described - curled it around and soldered.  I've tested the continuity from one solder point to the other without touching the multimeter to the wire, just the tab to ensure that there is current flow from the tab, to the wire, through the wire, to the next tab.  I can't find a gap anywhere.  

I also jumped from the back of the RCA jacks past the volume pot straight into the input tube (IE Very loud) and I am still having the same issue.


----------



## drtechno

Allanmarcus said:


> I always use the transformer that comes with the Bottlehead kits, so yes, I used a good transformer.
> 
> I'm pretty sure the Crack does not use any transformer from hammond. From the BH forum and posted by a BH employee:


looking at the closeup, it looks like a triad transformer. Still doesn't matter, I bet I could get Edcor to build one for $40, and with end bells


----------



## drtechno

bigfatpaulie said:


> Thanks.  Yeah, I did what you described - curled it around and soldered.  I've tested the continuity from one solder point to the other without touching the multimeter to the wire, just the tab to ensure that there is current flow from the tab, to the wire, through the wire, to the next tab.  I can't find a gap anywhere.
> 
> I also jumped from the back of the RCA jacks past the volume pot straight into the input tube (IE Very loud) and I am still having the same issue.


Ok, lets troubleshoot: What are the cathode voltages on both channels on both tubes?


----------



## bigfatpaulie

Thank yo so much for talking the time to help me: I really appreciate it!

You will have to do a little hand holding here, however.  I'd rather use terminal numbers (eg, A3 or B2) as I don't have the confidence to know exactly which terminal to test when you say cathode voltages (thought I suspect A4, A9, B8 and B7).


----------



## drtechno (Jul 13, 2018)

where's a schematic? here is the preamp tube pinout: 
	

	
	
		
		

		
			





 and your output: [IMAGE REMOVED]
so #3 and #8 on the preamp tube, #3 and #6 on the output tube.

BTW, these pictures are from the pin/soldering side (if you didn't know that)

is it this poorly designed one here? [IMAGE REMOVED]

2018-07-13 1121 EDT MODERATOR NOTE: Images removed at the request of the copyright holder.


----------



## bigfatpaulie (Jul 13, 2018)

Here are the labels:

[IMAGE REMOVED]

Just to be clear, I would be measuring DC from (for example) A1 to the grounding tab, correct?

2018-07-13 1124 EDT MODERATOR NOTE: Images removed at the request of the copyright holder.


----------



## drtechno (Jul 12, 2018)

Correct, 
This translates to A3 and A8, B3 and B6. And yes, you would measure DC from the grounding tab to the points.

btw, this looks like this constant current source:


----------



## bigfatpaulie

Thank you and no problem:

A3: 1.53
A8: 1.53
B3: 137.6
B6: 103.7


----------



## drtechno (Jul 13, 2018)

lol I found their manual... yes it is that poor design... too bad its too big to post at once, but page 7 would be ok.
this schematic they have in the manual is for a ac heater system. By what other said in the thread they used a 9V heater winding, which would be typical if they went DC with the design to curtail the poor power supply noise rejection.


----------



## drtechno

bigfatpaulie said:


> Thank you and no problem:
> 
> A3: 1.53
> A8: 1.53
> ...


tube A ok, tube B, the section B3 is not biased. Check your circuit in b3 for opens.


----------



## bigfatpaulie

drtechno said:


> tube A ok, tube B, the section B3 is not biased. Check your circuit in b3 for opens.



Interesting.  Okay.  But you will have to spoon feed a little bit here; what in a piratical sense, does "Check your circuit in b3 for opens" mean?


----------



## drtechno (Jul 13, 2018)

somewhere in the circuit, from B3 to ground is not connected. so the tube is exhibiting the plate voltage (or near plate voltage) on the cathode, because its not conducting (fully).  I would check the transistor's ground connection. R1  to ground of the constant current source board, and test the transistors (you don't have to pull them out in this circuit). Since its brand new, its not unheard of a 2n2222 to be bad brand new, thats why they are cheap (under a $1 each) and the tip50 is about half of that price. Could be bad solder joints and or wire connections too...


----------



## audiowize (Jul 12, 2018)

drtechno said:


> is it this poorly designed one here?


Posting  a manufacturer's design on here and making claims about its noise performance with no measurements is "bad design". (where are your designs btw?)  Hopefully a moderator will enforce copywrite rules on this one.

DC heating will not have any impact on power supply noise rejection, that's what the HV filtering is for.

To the OP, I think drtechno may have imbibed excessively at club last weekend, you'd be better off looking for help elsewhere.


----------



## Doc B.

I don't bother with this stuff usually, but your mistake is posting Bottlehead copyrighted IP without permission. Mods have been notified of your copyright violation. If you really want to improve your stature by denigrating my work don't take cheap shots on a forum, take me on in the street. Start an audio company, put out some of your own designs instead of stealing others, prove yourself regarding product support, surround yourself with a talented staff who are technically competent, capable of good designs of their own and have a reputation for some of the best customer support in the industry. Sell thousands of kits, millions of dollars of product over the years, earn hundreds of repeat customers. Earn respect from industry peers, get some great reviews, take a few best sound awards at trade shows along the way, sell some gear to Grammy winning recording engineers. While you are at it start a record label, revive a format. Get requests from those Grammy winning engineers for technical assistance in their recording sessions, get some album credits. Find yourself approached by some manufacturers to license your designs to them, and by others to offer service for their products. Grow the business for 25 years, put a couple of kids through college with it. Because right now son, you're not walkin' the walk, you're just talkin' the talk.


----------



## Paladin79

Very well said Doc.


----------



## drtechno (Jul 13, 2018)

audiowize said:


> Posting  a manufacturer's design on here and making claims about its noise performance with no measurements is "bad design". (where are your designs btw?)  Hopefully a moderator will enforce copywrite rules on this one.
> 
> DC heating will not have any impact on power supply noise rejection, that's what the HV filtering is for.
> 
> To the OP, I think drtechno may have imbibed excessively at club last weekend, you'd be better off looking for help elsewhere.


btw the design is older (1954 General Electric) than the company is and is a common circuit now. The design flaws of dc coupling without grid-stops was always been a topic off and on for decades with this circuit. Other flaws with this circuit is that it has no power supply rejection and all power supply and heater noise will be present on the output. The reason why they went to dc heaters is the fact that it takes a very high quality heater winding and a voltage regulator is cheaper than the high quality winding with a center tap that does not distort near center crossing under load. Vox AC30 has one in it btw...

The one design variant I like is that German guy that did it for McIntosh (patnent 1955) that is the same circuit John Brooskie markets as the Akido amp.


----------



## atomicbob

There is nothing "poor" about Doc's heater design. Here are dScope measurements for my Crack, which is close to original, non-speedball, though it does have the high voltage PS choke mod.
Please note these are UNWEIGHTED noise measurements. No A-weighting to make 60 / 120 / 180 Hz noise appear better than reality as is often published in manufacturers' specifications.



 

Those are damn decent figures for an all tube amplifier. Many manufacturers prefer not to list such as they struggle to achieve -78 ~ -80 dBr.

And here is a picture of how I enjoy my Crack:


----------



## Allanmarcus

atomicbob said:


> And here is a picture of how I enjoy my Crack:



you just need a glass of good scotch to make that picture perfect


----------



## Quadfather

Allanmarcus said:


> you just need a glass of good scotch to make that picture perfect



Do you mean bourbon? LOL


----------



## drtechno

atomicbob said:


> There is nothing "poor" about Doc's heater design.



Its a standard free domain circuit. Where are the patent numbers then...


----------



## Doc B.

Thank you, Bob. @drtechno - direct coupling is indeed common, however our specific design values and operating points are our IP and you are violating copyright laws when you post a schematic from our manual on the internet. Your statements about the power supply design are incorrect, and you are professing to know reasons for our design decisions when I don't even know you.


----------



## Allanmarcus

bored at work, so...


----------



## atomicbob

Allanmarcus said:


> you just need a glass of good scotch to make that picture perfect


Indeed. I'm looking forward to having a few drams of Macallan Rare Cask when I finish healing from cardiac surgery.


----------



## atomicbob

drtechno said:


> Its a standard free domain circuit. Where are the patent numbers then...


Huh? My Crack has an AC heater, which has been around since the beginning of valve usage. That isn't the issue. Posting copyrighted information is the issue. 

Again,there is nothing deficient concerning noise with the Crack, AC heater and all. Before the PS Choke mod I measured -89 ~ -90 dBr which is still much better than many other all tube headphone amps. PS Choke mod makes about 10 dBr improvement.


----------



## drtechno (Jul 13, 2018)

atomicbob said:


> Huh? My Crack has an AC heater, which has been around since the beginning of valve usage. That isn't the issue. Posting copyrighted information is the issue.
> 
> Again,there is nothing deficient concerning noise with the Crack, AC heater and all. Before the PS Choke mod I measured -89 ~ -90 dBr which is still much better than many other all tube headphone amps. PS Choke mod makes about 10 dBr improvement.


ok, Lets go a little generic. lets look at the input and the main circuits. Ok, lets look at this input. This old method of the first grid being applied directly to the wiper was bad practice indeed, as the wiper wears, and dirt gets in there, the moment the wiper stops contact with the carbon disk inside the control, the bias would go out of control. Just like this RCA variant, which is a little bit better design because they use negative feedback to add some power supply rejection. The tubes used isn't the point btw, it can do the same thing with something like a 6EM7 if needed. :    
	

	
	
		
		

		
		
	


	




  something like a 1M resistor to ground on the grid of the input tube would maintain a bias if the wiper opens....   now lets look at the 1955 drawing of the core of the circuit:    you see, there is no real rf blocking so all the rf noise in the first tube is dumped into the second tube. Using the correct gridstop resistor (both size, and type) will fix this. On the input in series with the grid, after the 1M we added and before the wiper, adding a grid stop will help isolate the circuit from the source device (ipod, computer, whatever it is....) onthe power supply side, a resistor divider in series with a final small cap that would help filter that lst bit of plate noise, but going to a positive and negative power supply, then injecting a ratio of the supply noises into the plate would make a better noise snubbing network. A more simpler, but not as effective approach is to use a modest plate choke with a single supply. Of course other things could be applied to the plate supply, like a tube diode in series, that would snub some of the noise, as well as provide a soft start.

the AC coupled output takes away from the dc coupled theme the circuit has. There are several circuits could be applied and reconfigured here, even a simple op amp servo.


----------



## drtechno (Jul 13, 2018)

Doc B. said:


> Thank you, Bob. @drtechno - direct coupling is indeed common, however our specific design values and operating points are our IP and you are violating copyright laws when you post a schematic from our manual on the internet. Your statements about the power supply design are incorrect, and you are professing to know reasons for our design decisions when I don't even know you.


Its circulating around the Internet just like the Fender and Marshall and everyone else's.  If Bob was still alive (the guy who designed the tube), he would give you a lecture on why the 6080/6as7 should be grid instead of cathode biased. There is nothing proprietary about voltage drops and bias points btw...


----------



## Eileen Schmalle

Allanmarcus said:


> bored at work, so...


Thank you for making my day! It's now my background screen LOL!


----------



## DavidA (Jul 14, 2018)

Allanmarcus said:


> bored at work, so...


Great image

@atomicbob, while I like scotch its wine, vodka or tequila for me, cheers​Cosmo


strawberry spritz


----------



## drtechno

love those cosmos


----------



## drtechno (Jul 14, 2018)

Doc B. said:


> I don't bother with this stuff usually, but your mistake is posting Bottlehead copyrighted IP without permission. Mods have been notified of your copyright violation. If you really want to improve your stature by denigrating my work don't take cheap shots on a forum, take me on in the street. Start an audio company, put out some of your own designs instead of stealing others, prove yourself regarding product support, surround yourself with a talented staff who are technically competent, capable of good designs of their own and have a reputation for some of the best customer support in the industry. Sell thousands of kits, millions of dollars of product over the years, earn hundreds of repeat customers. Earn respect from industry peers, get some great reviews, take a few best sound awards at trade shows along the way, sell some gear to Grammy winning recording engineers. While you are at it start a record label, revive a format. Get requests from those Grammy winning engineers for technical assistance in their recording sessions, get some album credits. Find yourself approached by some manufacturers to license your designs to them, and by others to offer service for their products. Grow the business for 25 years, put a couple of kids through college with it. Because right now son, you're not walkin' the walk, you're just talkin' the talk.



Don't get bent out of shape just because I tried to help someone with their "kit". Kit, as opposed to finished product. As far as your guide, it has the wrong approach in my opinion. There is so much you should cover, so it would be a learning experience for these guys, and not a paint-by-numbers guide. It just needs a WOMAN's touch... That's all... Now I'm off to the beauty shop...

and oh by the way, this 66 year old woman here doen't have to prove anything.


----------



## Kitchener

Man, this thread over the last couple of days...


----------



## bigfatpaulie

Yeah, I didn't mean to stir things up...  Sorry for the all trouble, everyone.


----------



## neogeosnk

Probably a stupid question but.. what is the crack 1.1 & speedball vs.  regular crack  w. speedball?


----------



## Eileen Schmalle

neogeosnk said:


> Probably a stupid question but.. what is the crack 1.1 & speedball vs.  regular crack  w. speedball?


Hi Neogeosnk! Thank you for asking your question, questions are never stupid! The Crack1.1 is our latest updated version of the Crack which offers a universal power transformer and can be used worldwide by following the wiring instructions in the manual otherwise it still offers the same great sound as our original Crack.


----------



## brokensound

I did a quick search and couldn't find an example of folks using the Vishay MKP capacitors. So if you had trouble fitting three 100uF capacitors in the stock case along w/ the choke and schottky diode, these wonderful rectangular capacitors are worth exploring. It is rated for 500v. I picked mine up on Amazon for ~$20, which is even cheaper than the Audyn Q4s. I used it to replace the last power supply capacitor. My impression is that it improved the weight of the music, namely, the bass sounded more authoritative.


----------



## Bruc3

hi all,

I live in Sydney, Australia and am very keen on pairing a BH crack + speedball with my HD6xx.

Any Aussies here willing to build one for me if I buy the kit?

Of course I will pay for your services. Its hard to find a used one here in Australia and I don't have confidence to build one myself.


----------



## Tom-s

Crack's been my first DIY kitbuild. I learned to solder by building Crack.
Thanks to the superb manual, even with skill-level 0, Crack is a safe bet.
Be confident, you can build it.
For the money, and how it taught me a lot about how audio, tubes and stuff works (all, that standard, of the shelf stuff didn't) it is probably the best amplifier i ever bought and ever will buy.
Compared to many (more expensive) amps the last few years, i can say with confidence that the Crack is indeed a gaint-killer with Sennheiser HD6xx/HD800 headphones.
The journey, building it, enjoying it, modding it, enjoying it further is what makes the Crack special. Don't miss out on that, build one yourself.


----------



## JamieMcC

Bruc3 said:


> hi all,
> 
> I live in Sydney, Australia and am very keen on pairing a BH crack + speedball with my HD6xx.
> 
> ...



Hi you could try giving  Loquah a pm he has built a number of Bottlehead kits if he can't help then he will probably know some one who can.

I would really recommend you give the build a go you self. I was like many others having never soldered or used a multi meter before and had the same doubts as yourself. The instructions are really good and easy to follow there is always a picture along with the text for reference so if your not quiet sure about how something has been described in the text looking at the picture normally makes it crystal clear.

Learning to solder and with the confidence gained in building your own Crack can lead to all sorts of other great diy audio projects. 
Its a lot of fun and a neat hobby.

https://www.head-fi.org/members/loquah.152302/


----------



## Eileen Schmalle

Tom-s said:


> Crack's been my first DIY kitbuild. I learned to solder by building Crack.
> Thanks to the superb manual, even with skill-level 0, Crack is a safe bet.
> Be confident, you can build it.
> For the money, and how it taught me a lot about how audio, tubes and stuff works (all, that standard, of the shelf stuff didn't) it is probably the best amplifier i ever bought and ever will buy.
> ...


Thank you for your post Tom! I'm so happy that you got so much out of building the Crack kit and had such a good experience.


----------



## Bruc3 (Jul 18, 2018)

Guys, I think you may have convinced me to try building one.

I will wait till the kit is on sale again before I purchase though as its pretty expensive now buying from Australia (import tax, weak AUS dollar)

In meantime I will start reading on soldering tutorials.

In regards to tools for the job, could I just buy below to do it?

Solder kit:
https://www.jaycar.com.au/20-130w-soldering-iron-starter-kit/p/TS1651

Multimeter
https://www.jaycar.com.au/low-cost-digital-multimeter-dmm/p/QM1500


----------



## Stillhart

Bruc3 said:


> Guys, I think you may have convinced me to try building one.
> 
> I will wait till the kit is on sale again before I purchase though as its pretty expensive now buying from Australia (import tax, weak AUS dollar)
> 
> ...



There are tons of good soldering tutorials online.  I just watched some from this guy and I thought they were pretty helpful:  https://tangentsoft.net/elec/movies/

Regarding those items, I'm sure they'll work fine to get you started.  That DMM doesn't appear to come with the test probes though, so you'll have to add those in.


----------



## Bruc3 (Jul 18, 2018)

Stillhart said:


> There are tons of good soldering tutorials online.  I just watched some from this guy and I thought they were pretty helpful:  https://tangentsoft.net/elec/movies/
> 
> Regarding those items, I'm sure they'll work fine to get you started.  That DMM doesn't appear to come with the test probes though, so you'll have to add those in.



Thanks I will checkout those soldering tuts.

Is this the test probes here:
https://www.jaycar.com.au/multimeter-test-probes-shrouded-type/p/WT5325

And little additional tools I need are:
- plyers
- screwdriver
- wire cutter/stripper

Will that cover everything for the job? Assuming I have nothing at the moment.


----------



## Stillhart

Bruc3 said:


> Thanks I will checkout those soldering tuts.
> 
> Is this the test probes here:
> https://www.jaycar.com.au/multimeter-test-probes-shrouded-type/p/WT5325


Those will definitely fit.  They cost more than the DMM though... lol


----------



## Bruc3

Stillhart said:


> Those will definitely fit.  They cost more than the DMM though... lol



Lol, oh the one's here are cheaper, should do the job yeah?
https://www.jaycar.com.au/multimeter-test-probes-930mm/p/WT5316

Also what size wire stripper do i need?


----------



## Stillhart

Bruc3 said:


> Lol, oh the one's here are cheaper, should do the job yeah?
> https://www.jaycar.com.au/multimeter-test-probes-930mm/p/WT5316
> 
> Also what size wire stripper do i need?


Looks good to me.  For wire strippers, I use something like the below (though obviously a much cheaper version):

https://www.jaycar.com.au/stainless-steel-wire-stripper-cutter-pliers/p/TH1841


----------



## Paladin79

with a bit of work you can alter the looks of the amp as well.


----------



## Bruc3

Stillhart said:


> Looks good to me.  For wire strippers, I use something like the below (though obviously a much cheaper version):
> 
> https://www.jaycar.com.au/stainless-steel-wire-stripper-cutter-pliers/p/TH1841



Thanks, looks like I am pretty much set on the tools.


----------



## Bruc3

Paladin79 said:


> with a bit of work you can alter the looks of the amp as well.



Yeah that is the next thing I will research into, I have never painted anything either so need to read up on basics.

I was thinking just buy a can of black spray paint to do the wood and metal top plate but I am guessing it probably involves a little more than that.


----------



## Paladin79 (Jul 18, 2018)

Mine involved quartered oak and copper plate, I did spray paint the transformer bell.

Patinated copper and danish oil otherwise. 

I also changed pots, added front and back plates and left the top clean except for tubes and transformer.


----------



## Quadfather

Well, I just got my QP1R back from battery indicator repair.  This is what I usually use for my Crack. Some much-needed time with my crack and 650s!!!


----------



## attmci

So quite here.


----------



## Paladin79

It may become less quiet, Jason Stoddard is doing a new chapter in Schiit Audio talking about DIY companies and Bottlehead is mentioned there in a list of such companies.

https://www.head-fi.org/threads/sch...lds-most-improbable-start-up.701900/page-2473


----------



## Tom-s (Aug 29, 2018)

To get some life into this topic:

Because of a small defect (red led bias of the driver tube died somehow), i'm limited to running 5687/7119/6n6p etc. This means i'm rolling a lot more with 6080/6as7g and variants.
So went trough some "cheap" power tubes and concluded i liked most with my headphones HD800 (with 7119 Heerlen made super tube):
- Thomson CSF 6080, +-10€; airy, V shaped, detailed, bit loose in the bass (sold as Telefunken from time to time, but then you pay way too much haha).
- 6H13C Svetlana, +-15€; enough air, strong bass, even bass heavy, less details but good on that part, easy on just about every recording. 

Edit: Sylvania 6080WC, Philips, RCA, some more, not worth it..

Now listening to:


----------



## attmci (Aug 29, 2018)

Tom-s said:


> To get some life into this topic:
> 
> Because of a small defect (red led bias of the driver tube died somehow), i'm limited to running 5687/7119/6n6p etc. This means i'm rolling a lot more with 6080/6as7g and variants.
> So went trough some "cheap" power tubes and concluded i liked most with my headphones HD800 (with 7119 Heerlen made super tube):
> ...



Tom, I recall there is a eBay seller at UK have these cheap.

https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=HLMP-6000+LEDs&_sacat=0


----------



## Tom-s

Thank you. I have a few spares laying around. Just didn't make time to replace them.


----------



## attmci

Tom-s said:


> Thank you. I have a few spares laying around. Just didn't make time to replace them.


I see. You have mod the Crack, now it's hard to reach it. LOL


----------



## Th3Drizzl3

just started my first crack build so far its been pretty simple mi us the fact my hakko actually took a crap on me im a bit upset its under warranty but still. so im using a el cheapo 60watt radio shack iron and got nearly everything soldered up tonight. used 67/33 lead based flux solder.


----------



## audiowize

Th3Drizzl3 said:


> just started my first crack build so far its been pretty simple mi us the fact my hakko actually took a crap on me


If you have the FX-888, it's very easy to think you're turning up the iron temperature when you're actually calibrating the iron and making the tip significantly cooler.  There are directions in the manual to reset the iron, as well as the proper steps to turn the temp up.  I went through the same thing right after I bought my 888.


----------



## Th3Drizzl3

i have the fx-951 i checked everything.


----------



## Paladin79

Th3Drizzl3 said:


> just started my first crack build so far its been pretty simple mi us the fact my hakko actually took a crap on me im a bit upset its under warranty but still. so im using a el cheapo 60watt radio shack iron and got nearly everything soldered up tonight. used 67/33 lead based flux solder.



Folks swear by Hakkos but I have tried some in production situations without good results. More often than not my people use Wellers and many have run for ten years, five days a week 8.5 hours a day.


----------



## Th3Drizzl3

this is the second one that died on me over the years. sadly my soldering this time is not as flawless as i usually do but its way more then acceptable. the gun i used sucked.


----------



## Paladin79

Contact me if you ever get in that situation again, I used to run my own shop and still own multiple Wellers, some new in the box. I can send you a loaner.


----------



## Th3Drizzl3 (Aug 29, 2018)

i just ordered a new weller. ill give it a shot. never a fan personally but i know they are workhorses. i love my hakko tips. lol this job is still better then i usually see im very ocd with stuff like that so i habe to get it perfect like component spacing and height off the board etc otherwise im not a happy camper lol. i def appreciate the offer. lmk if u ever want to sell one off also would love a backup


----------



## Paladin79

Weller has a large variety of tips, I build Coaster amps using them as well as Cracks, and other through hole soldering.


----------



## Paladin79 (Aug 29, 2018)

Th3Drizzl3 said:


> i just ordered a new weller. ill give it a shot. never a fan personally but i know they are workhorses. i love my hakko tips. lol this job is still better then i usually see im very ocd with stuff like that so i habe to get it perfect like component spacing and height off the board etc otherwise im not a happy camper lol. i def appreciate the offer. lmk if u ever want to sell one off also would love a backup



What I have are not as fancy as new Wellers but I will look around my shop this weekend, I bet I have two or three new on the box and I used to buy tips ten at a time so I could include some of those. If anything fails other than the transformer there are parts available, heaters, switches, handle sets. etc.

OCD is not always a bad thing, some of my best employees are like that, their tools are well laid out, their work is precise and their work areas are clean. Sometimes their food cannot touch other food and they have to eat all of one item before starting on the next but that has little to do with work habits lol.

For those of you not familiar with the Coaster amp, you can build it as a hybrid headphone amp or never install a part and use it for a drink coaster. Made by Schiit corp more as a novelty than anything else but a fun, one day diversion. Mounting them in a suitable container takes some serious thought.


----------



## Th3Drizzl3

Yeah I had to use this old ancient thing that the tip was a mess on I tried cleaning it but it was as good as it was getting lol. It's a pos lol. It's the one I use for literally anything except soldering usually haha


----------



## Th3Drizzl3 (Aug 29, 2018)

Minus some of the leads not trimmed fully u can still do a decent job with a junk gun though. Is it as perfect as I would have liked no. But it's not bad. just no smd stuff with it lol. that would not work. lol


----------



## CAPT Deadpool

I've got one coaster built, working on a second. 

I'm also about 50% through on a Crack 1.1

I used a cheap ~20-30 Weller for the first coaster.  I bought a Weller 1010NA and switched from 60-40 to 63-37 and I think things are working much better.  Now if I could only pay attention enough to avoid singeing nearby wires' insulation on the Crack (will be replacing those later).


----------



## Paladin79

You did the harder build first so the Crack should be a pleasure for you to build. Eventually you will learn about wire placement and keeping the soldering iron from touching things it should not. There is a reason only five of us have the Coasters going so far, I would suspect the Crack is among the largest selling kit amps out there.

 Having seen some of Th3Drizzl3's work I would not have a problem owning something he has built, and I have seen plenty of soldering.


----------



## CAPT Deadpool

Luckily as the son of an electrician I should have no trouble at all getting a little scrap 20AWG to replace the singed wires with.  His company keeps reels of the stuff and the lengths I need are literally trash for their purposes.  I've worked with him on large cables like 500 MCM in a drydock.


----------



## Th3Drizzl3

im using silver wire for this crack because i have some left in small pieces that would have prob been tossed but i like to keep a small scrap bin for wires this size.


----------



## Quadfather (Aug 30, 2018)

My bottlehead crack, with a Tung Sol 5998, and a Mullard CV4003 with a Dale stepped attenuator is getting no use. It is in mint condition.  What is the typical price that would be fair in the classifieds?  Both tubes were procured, and tested from tubedepot and new old-school tubes


----------



## Paladin79

I do believe HeadFi has restrictions on what you can charge here, kit price plus maybe some parts or some such. Lesser builds than what you have are on EBay for $730 as I recall. You could probably get more there IMHO.


----------



## Th3Drizzl3

it always amazes me when i see what some people pay for a slightly modded crack on ebay.


----------



## joaogma

Hello guys!

Would anyone advise me for getting a Speedballed Crack for hiphop listening? Is there any deep bass roll off with the stock tubes? Should I go SS for this particular genre?

I'm really considering getting one for my HD650 

Thanks in advance.


----------



## Paladin79

joaogma said:


> Hello guys!
> 
> Would anyone advise me for getting a Speedballed Crack for hiphop listening? Is there any deep bass roll off with the stock tubes? Should I go SS for this particular genre?
> 
> ...



The Crack is an excellent amp for HD650's I have to admit I do not listen to any hiphop but I like it with other music genres. (I do not listen to rap either but each to their own.) I am terrible at describing things like bass but I do have several class A solid state amps and I am more partial to the bass of the Crack.


----------



## Th3Drizzl3

joaogma said:


> Hello guys!
> 
> Would anyone advise me for getting a Speedballed Crack for hiphop listening? Is there any deep bass roll off with the stock tubes? Should I go SS for this particular genre?
> 
> ...


imo the speedball makes the amp much better. some dislike it though. i had another crack (one i didnt build) i used it with my 6xx's all the time. sounded great, imo the speedball makes the backround even more quiet, makes the amp sound faster, have more impact, its more resolved.


----------



## Th3Drizzl3 (Aug 30, 2018)

so heres a question before i finalize this thing the 9 pin front socket is your a bit loose under the mounting ring? i have it as tight as it will go and the 9 pin really moves around a good amount in the hole like if i shake the plate the 9 pin rattles? the other socket is nice and snug without being to tight. im torn on the top plate finish still.

i have not fully snapped in the switch or the wall sockets yet so i can easily get them out. im thinking a orange or titanium chrome vinyl over the top or polishing it or an actual hammer type finish (you can achieve this in the aluminum but it takes a long time and is super tedious i have a friend who is a blacksmith who showed me this type of finish before) or leave it bare just because i like the look. hmmmmmmmmm. lol i was going to just anodize it at first but now im undecided haha

i do have a custom real carbon fiber top plate being made for the second kit i have here that should be interesting. ill have to run a ground for everything since the top will not be metal though


----------



## CAPT Deadpool

MAster shake i mean tha drizzle.  My 9pin is solidly attached to the metal plate.  My socket soldering loops move a bit but not the socket itself.  Did you put the retaining ring on top?


----------



## CAPT Deadpool (Aug 30, 2018)

But im still putting mine together thatnks to your question i noticed that one lead was loose when I wiggled my socket so thank you


----------



## Paladin79

With the retaining ring on top the nine pin socket should be nice and tight. I have not tried mounting that socket underneath.


----------



## Th3Drizzl3

I am using the retaining ring and it's as tight as it's getting and the white socket moves around a good amount inside the retaining ring. The larger socket is solid as can be. It is also mounted on top as it said in the instructions.


----------



## Paladin79 (Aug 30, 2018)

Th3Drizzl3 said:


> I am using the retaining ring and it's as tight as it's getting and the white socket moves around a good amount inside the retaining ring. The larger socket is solid as can be. It is also mounted on top as it said in the instructions.


That does not sound right, can you post a photo?

Here is one of mine, socket is flush across the top, ring holds it firmly. I may have changed out the socket for a ceramic one but the principle should be the same.


----------



## Th3Drizzl3

from a pic it looks perfect but if you grab the white socket you can move it around. ill take a pic though. its def mounted per directions


----------



## Th3Drizzl3




----------



## Paladin79 (Aug 30, 2018)

Mine does not budge in the least. The ring should fit snugly. I will try to catch up tomorrow if you are still having issues.

Which part wiggles, the metal ring in the very center?


----------



## Th3Drizzl3

i can literally turn the socket back and forth about an 1/8" and move it back and forth. ive tried flattening the ring some and its the same way. i may have to order a ceramic socket instead.


----------



## CAPT Deadpool

Did u use all the washers etc?


----------



## Th3Drizzl3

yes. exactly per directions checked multiple times


----------



## CAPT Deadpool

Can you take a picture of the other side.  And did you use one short and one longer screw for each socket?


----------



## CAPT Deadpool (Aug 30, 2018)

Weve got Lots of ?s just trying to help.  I asked Paladin for his help earlier for u


----------



## audiowize

It is not the end of the world if the socket moves a little bit.  You can put a drop of super glue on the back side of the plate between the plate and the socket to lock it in place.


----------



## Th3Drizzl3

i think i figured it out. the retaining ring has a good amount of extra metal on the underside of it where the screws go through its not flat at all. looks like when they punch the holes in that metal they were never cleaned up.


----------



## CAPT Deadpool (Aug 30, 2018)

Glad you figured it out.  Would p**s me off if It happened to me.  THAnks for posting the problem you probably won’t be the only one


----------



## Th3Drizzl3 (Aug 30, 2018)

i just used a wet stone and flattened the wings out really nice where the screws go ill report back. its nice and smooth though now. 

edit. not perfect yet but a LOT better. i can move it still but it takes a bit more force to move it around now. it doesnt just rattle around im going to take a tad bit more off and test again


----------



## Th3Drizzl3

@Paladin79  where did you find the ceramic socket you used? if you would share id like to get a few. the one they included is very meh imo


----------



## Paladin79

It’s been a while but I found them on ebay


----------



## Th3Drizzl3

ill look again i searched for them but nothing came up that would fit. thanks!

i took a tiny bit more off the ring and its nearly polished on the bottom of the wings now lol. im also going to add a couple delrin flat washers under the screw heads there on top because it did kink the thin metal a bit where the screws were tightened.


----------



## Th3Drizzl3 (Aug 30, 2018)

ahhhh perfect now. nice and snug now i cant even move it at all. so if anyone has this issue take the mounting ring and gently file down the bottom side of the wings a bit and its perfect.

edit again found a couple that would fit. hopefully they are a bit nicer then this one. i found a few brass retaining rings also im going to test out.


----------



## atomicbob

atomicbob's nuclear crack system:




 

My crack is non-speedball, has power supply choke mod, re-biased for Tunsram e80cc driver, and larger than normal output capacitors, which requires care during power up (headphones disconnected until warmed up.)
HD800 J-mod headphones (originally modified by mikoss.)


Here is a hot-rod analogy to what this system is like:


----------



## chuckwheat

It has been a while since I've touched my beloved bottlehead crack amp. I'm looking to get back to regular music sessions, but I think my crack needs some help. It's the stock crack with speedball, and I've replaced the smaller tube with a new Mullard 12au7 ecc82.  I'm experiencing consistent ringing and humming noises in the left channel. When I press or wiggle the big power tube, I can get it to go away for a short time. This was always the case after I assembled it almost 2 years ago, but I'd love to solve it once and for all. Does anyone have any tips on what I can do? Thanks fellas


----------



## hawkwindx

chuckwheat said:


> It has been a while since I've touched my beloved bottlehead crack amp. I'm looking to get back to regular music sessions, but I think my crack needs some help. It's the stock crack with speedball, and I've replaced the smaller tube with a new Mullard 12au7 ecc82.  I'm experiencing consistent ringing and humming noises in the left channel. When I press or wiggle the big power tube, I can get it to go away for a short time. This was always the case after I assembled it almost 2 years ago, but I'd love to solve it once and for all. Does anyone have any tips on what I can do? Thanks fellas



I had a tube that would cause some ringing. I switched to a different tube, and no ringing. So in your case, maybe it's the tube.


----------



## AthenaZephyrian

atomicbob said:


> atomicbob's nuclear crack system:
> 
> 
> 
> ...



Good for rock?


----------



## AthenaZephyrian

chuckwheat said:


> It has been a while since I've touched my beloved bottlehead crack amp. I'm looking to get back to regular music sessions, but I think my crack needs some help. It's the stock crack with speedball, and I've replaced the smaller tube with a new Mullard 12au7 ecc82.  I'm experiencing consistent ringing and humming noises in the left channel. When I press or wiggle the big power tube, I can get it to go away for a short time. This was always the case after I assembled it almost 2 years ago, but I'd love to solve it once and for all. Does anyone have any tips on what I can do? Thanks fellas



I got a vintage 12aT7 I pulled out of an old philco radio.  No idea if it works, but I can do a multimeter test sometime next week, and if nothing seems amiss, I'm happy to post it to you if you cover S&H.


----------



## JamieMcC (Sep 2, 2018)

Th3Drizzl3 said:


> so heres a question before i finalize this thing the 9 pin front socket is your a bit loose under the mounting ring? i have it as tight as it will go and the 9 pin really moves around a good amount in the hole like if i shake the plate the 9 pin rattles? the other socket is nice and snug without being to tight. im torn on the top plate finish still.
> 
> i have not fully snapped in the switch or the wall sockets yet so i can easily get them out. im thinking a orange or titanium chrome vinyl over the top or polishing it or an actual hammer type finish (you can achieve this in the aluminum but it takes a long time and is super tedious i have a friend who is a blacksmith who showed me this type of finish before) or leave it bare just because i like the look. hmmmmmmmmm. lol i was going to just anodize it at first but now im undecided haha
> 
> i do have a custom real carbon fiber top plate being made for the second kit i have here that should be interesting. ill have to run a ground for everything since the top will not be metal though



Carbon fibre conducts electricity you should be able to ground your carbon plate the same as the stock alloy one however the type of resin used and method used in forming the carbon sheet material will have an impact on how conductive the carbon ends up.

Its easy enough to test conductivity with a multi meter on the underside of the carbon plate before you start. Where the ground connections are made it would be advisable to locally sand the carbon to remove any surface resin  to expose the actual carbon fibres for better conductivity. Similar to how you would remove paint or anodized finish to expose the metal.

Couple of pics that show the 12au7 mounted on the top and from below with a carbon top plate in case its any help. Its pretty easy to mount both ways and see for yourself.

Went with from underneath myself.


----------



## Tom-s

chuckwheat said:


> It has been a while since I've touched my beloved bottlehead crack amp. I'm looking to get back to regular music sessions, but I think my crack needs some help. It's the stock crack with speedball, and I've replaced the smaller tube with a new Mullard 12au7 ecc82.  I'm experiencing consistent ringing and humming noises in the left channel. When I press or wiggle the big power tube, I can get it to go away for a short time. This was always the case after I assembled it almost 2 years ago, but I'd love to solve it once and for all. Does anyone have any tips on what I can do? Thanks fellas



Sounds like a problem with the powertube. Replace it with another and test again.
Bottle shaped or larger glass envelope powertubes are more suspectable for microphonics in my experience.

If in EU, i have enough spares.



AthenaZephyrian said:


> I got a vintage 12aT7 I pulled out of an old philco radio. No idea if it works



Even if it works (and they will when good); PB on Bottlehead forum strongly recommended me once not to use them.
As these would severely impact the operating points of Crack's powertube in a negative way.


----------



## Paladin79

A friend from here gave me a couple very nice old 6SN7's to try my crack in place of the 12AU7. The change is shocking and very good. I am running a Schiit Gungnir Dac into a Freya pre-amp with four of Tung Sol 6SN7's in it. The tube sound is crisp and accurate but has the warmth I seek.


----------



## buke9

You find the Tung Sol 6SN7’s to be a bit warm on the Freya? I have been seeking that myself .


----------



## Paladin79

In my opinion, yes.


----------



## buke9

Just been trying to warm up my Freya .


----------



## Paladin79 (Sep 13, 2018)

I like them better than the stock tubes but like I said I am listening through the Crack so that probably helps. Tomorrow i will try the Freya with a Whammy amp for a better comparison. Saturday some friends come over for some testing so I need to set some things up anyway.


----------



## chuckwheat

Tom-s said:


> Sounds like a problem with the powertube. Replace it with another and test again.
> Bottle shaped or larger glass envelope powertubes are more suspectable for microphonics in my experience.


Hey, I got a "WINGED C 6H13C / 6AS7G" and the annoying sounds were immediately relieved.  It also sounds much better overall. Thanks for the advice.


----------



## larcenasb (Sep 19, 2018)

This Crack journey continues to be amazing! I've been at this the past 4 years now, upgrading literally one thing at a time. Now, I really don't have room! My latest upgrade is the Valab 23-step attenuator (coming from a padded Alps 100KAX2). There is no need to pad the Valab, the 23 steps provide fantastic range without getting too loud too early, with plenty of headroom towards the end of the range. With the padded Alps, some vinyl albums didn't quite get loud enough with the pot turned to max--only to 9 out of the the Spinal Tap 11 range. Also, clarity is noticeably improved, as is instrument separation. YAY!


----------



## Rhamnetin




----------



## larcenasb

LOL, if you mean me Rhamnetin, I cannot refute your claim.


----------



## Rhamnetin

larcenasb said:


> LOL, if you mean me Rhamnetin, I cannot refute your claim.



Yes you! That inspires me though, lovely work. I think I will also use my Bottlehead Crack as an ongoing project like that, for fun and to improve my DIY skills. I probably won't go as far as you though.


----------



## larcenasb (Sep 19, 2018)

Rhamnetin said:


> Yes you! That inspires me though, lovely work. I think I will also use my Bottlehead Crack as an ongoing project like that, for fun and to improve my DIY skills. I probably won't go as far as you though.



 Thanks so much! This feeling right now--listening and relaxing after building--is just the best. I hope you get to this point soon as well with your build. However far you go, at least you can look at an example that really stuffed the limited dimensions to give you a baseline.

FYI, I believe the most important upgrades are tubes (IMO 6SN7 or 6F8G w/ adapters), the Speedball kit, and a new pot/attenuator to fix the stock low-volume channel imbalance (Alps or Valab were my choices). The caps and the rest added to an overall smoother, high-end sound, but it's very subtle. Cheers and take care!


----------



## attmci (Sep 19, 2018)

larcenasb said:


> This Crack journey continues to be amazing! I've been at this the past 4 years now, upgrading literally one thing at a time. Now, I really don't have room! My latest upgrade is the Valab 23-step attenuator (coming from a padded Alps 100KAX2). There is no need to pad the Valab, the 23 steps provide fantastic range without getting too loud too early, with plenty of headroom towards the end of the range. With the padded Alps, some vinyl albums didn't quite get loud enough with the pot turned to max--only to 9 out of the the Spinal Tap 11 range. Also, clarity is noticeably improved, as is instrument separation. YAY!


You used 6F8G or 6C8G? Both should work on the Crack (with adapter https://www.ebay.com/itm/1pc-Gold-p...388446?hash=item2c8398c5de:g:NCwAAOSwu4BVwu6v), and better than most of the 12AU7.


----------



## larcenasb (Sep 19, 2018)

Yeah, I use the 6F8G and 6SN7GT. I prefer their sound much more than any 12AU7. The Mullard 12AU7 long plate was the best I've heard of that miniature 9-pin family, but it still can't compare to the octals IMO.

EDIT: I should be specific...I much prefer the octals for their wider, deeper soundscape. And for the fat, weighty tones that are much more lifelike than the thin, restrained sounds that I hear from 12AU7s. Just my two cents. However, I did read about audio engineers and radio enthusiasts complaining about the 12AU7 in the 50s, saying it was an obvious sonic compromise to the octals of the 40s. I just so happen to agree.


----------



## attmci

larcenasb said:


> Yeah, I use the 6F8G and 6SN7GT. I prefer their sound much more than any 12AU7. The Mullard 12AU7 long plate was the best I've heard of that miniature 9-pin family, but it still can't compare to the octals IMO.


You are neighbor of the Bottlehead. 

Enjoy and get a HD-6XX later.


----------



## larcenasb

attmci said:


> You are neighbor of the Bottlehead.
> 
> Enjoy and get a HD-6XX later.


Yeah, I've been meaning to take the ferry to their headquarters for a meet--hopefully the next one! I absolutely love my K240 collection(!), but I should hear what the fuss about the Sennheisers is all about. Maybe around the holidays!  Cheers!


----------



## S3nsoryDeprivati0n

Just had to post: On my Bottlehead Crack with Speedball, I have an RCA 6080 NOS, and it was paired with a GE 12AU7.  I'm using DT 770 Pro 250, which I expect to be bright.  Even so, the sound was muddy.  Well, I put in an RCA Clear Top 12AU7, and the improvement was ridiculous.  Now, I know this combo probably is a 5/10 from what I've read, that a RCA Clear Top is a side-grade, so imagine what it was like before.  Seriously stoked.  Now, its still too smooth on the HD 650s for my liking, and I really want to brighten them up, so I've ordered a Tung Sol 12AU7 re-issue, and was sly enough to secure a NOS Tung Sol 6AS7G, and a Thomson CSF 6080.  Not sure which combo will be best, but looking forward to finding out.


----------



## larcenasb

S3nsoryDeprivati0n said:


> Just had to post: On my Bottlehead Crack with Speedball, I have an RCA 6080 NOS, and it was paired with a GE 12AU7.  I'm using DT 770 Pro 250, which I expect to be bright.  Even so, the sound was muddy.  Well, I put in an RCA Clear Top 12AU7, and the improvement was ridiculous.  Now, I know this combo probably is a 5/10 from what I've read, that a RCA Clear Top is a side-grade, so imagine what it was like before.  Seriously stoked.  Now, its still too smooth on the HD 650s for my liking, and I really want to brighten them up, so I've ordered a Tung Sol 12AU7 re-issue, and was sly enough to secure a NOS Tung Sol 6AS7G, and a Thomson CSF 6080.  Not sure which combo will be best, but looking forward to finding out.


You might want to try a Tung-Sol 7236 to replace your 6080. I think most around here would agree that swapping the output tube makes the most noticeable difference to your sound (although the input tube really fine-tunes the sound to your liking). The 7236 is lively and very dynamic, with clarity comparable to the coveted 5998/421A--I imagine it will wake up your HD 650s. I got my 7236 from someone on eBay who has a whole lot of them from storage and--although untested--is selling them at $35 a piece, so it may be worth it for you to try. My tube was in great condition and worked great.


----------



## Paladin79

Here is my latest endeavor, a Crack cabinet for a friend. Front and back plates, quartered oak cabinet, 1/8 inch copper.


----------



## cobrabucket

Paladin79 said:


> Here is my latest endeavor, a Crack cabinet for a friend. Front and back plates, quartered oak cabinet, 1/8 inch copper.



Day-um! That is sexy. Very nice!


----------



## cobrabucket

Just bought a BHC from *S3nsoryDeprivati0n. *Super stoked!*https://www.head-fi.org/members/s3nsorydeprivati0n.443922/*


----------



## cobrabucket

I'm guessing that the BHC is not a particularly good pairing for either a HE 400i or Argon Mkiii, eh?


----------



## Tom-s

Being low impedance headphones Crack won't be the best match. 
It will truly shine with the HD6xx headphone mentioned in your signature.
For the HE 400i or Argon MKiii i'd look at the S.E.X. 3.0 kit first and Mainline kit as a second instead.


----------



## Tom-s

For everyone looking for the best bang for buck DIY OTL high impedance headphone kit: Crack's on sale from October 4th to October 8th!

I'm just promoting this as it was the DIY Kit that got me into the world of DIY audio and saved me a lot of money in the process!

I honestly think, because of the good manual and support forum that everyone can build one.


----------



## larcenasb (Oct 4, 2018)

Tom-s said:


> For everyone looking for the best bang for buck DIY OTL high impedance headphone kit: Crack's on sale from October 4th to October 8th!
> 
> I'm just promoting this as it was the DIY Kit that got me into the world of DIY audio and saved me a lot of money in the process!
> 
> I honestly think, because of the good manual and support forum that everyone can build one.


Wow, great sale right now... And I totally agree, we're in the same boat, the Crack saved me tons of money and continues to supply aural nourishment each evening for me. I remember seeing Skylab's ranking of tube amps here on head-fi and being shocked at how high the affordable Crack was placed (#8), it clearly represented amazing value on that list. So, that's when I bought it! Also, it was placed way above the Woo Audio 3 (#17) which was $495 while the Crack was $219 + $99 for the speedball at the time--so $495 vs $318. And the amps that placed higher than the Crack were $750, $620, $1K, $2K, $4K! What makes me content is to know that ranking was of a _stock_ Crack and Speedball...mine is completely modded out and no where near stock! So, I have no desire to upgrade from my beloved Bottlehead, just headphones later on perhaps. 

EDIT: Here's that Skylab ranking: https://www.head-fi.org/threads/rev...2-tube-and-tube-hybrid-headphone-amps.402585/
It was a great resource for me starting on my headphone journey, hopefully it's of help to anyone who hasn't seen it.


----------



## Paladin79 (Oct 11, 2018)

Listening to a set of Tung Sols in the Crack, I am suddenly a huge fan of 6SN7's but most of you probably know about them. Feeding the Crack from a Schiit Gungnir multibit DAC and a Freya preamp just to allow some easy switching and a bit more tube sound. Tung Sol 6sn7's in that as well. I own ten or more headphone amps but always find myself returning to the Crack, I love this amp.


----------



## larcenasb

Oh my goodness, your build is more gorgeous than I remember! And I love the black tube adapter  it really blends in better than if it were gold and white! It's nice to know you love your Crack when you have so many other amps as well, that makes me cherish mine more than I already do. Here's to more hours into the night, getting some tube nourishment!! Cheers!


----------



## CAPT Deadpool

Paladin79 said:


> Listening to a set of Tung Sols in the Crack, I am suddenly a huge fan of 6SN7's but most of you probably know about them. Feeding the Crack from a Schiit Gungnir multibit DAC and a Freya preamp just to allow some easy switching and a bit more tube sound. Tung Sol 6sn7's in that as well. I own ten or more headphone amps but always find myself returning to the Crack, I love this amp.



Where did you get your feet and the vent cover?  I'd like to buy something like them.  

Are the Tung Sols new or NOS?  How do they compare to other 6SN7s?  

Have you tried any *6F8G*'s?  I've seen a lot of pics of what looks like them installed front tube socket.


----------



## Paladin79

I ordered the feet off of Amazon, if I can find the link I will send it to you later. 

The vent cover is the inside of an old pocket watch, all brass I believe. I found it in a group of such things I bought on Ebay so it is pretty well one of a kind. Since I knew I was doing Steampunk, I bought lots of old watch parts and gears. Some of them I used in two copper and brass headphone stands I built. I traded some of those out and put in an Edison light that you can nearly make out in the photo. Originally I just had a hole in the top plate and copper mesh under it to allow for ventilation. There are plenty of gaps in the pocket watch to allow air flow.

The Tung Sols were probably used but in good condition as far as I recall, I have hmmmm 200 tubes, it is kind of tough to recall the origin of each. I did receive an RCA tube from 1942 from a gentleman on here, 6sn7, that has to be my favorite tube but last night I was just swapping tubes for the heck of it.  To be honest I found the Tung Sol 6SN7 in a drawer and did not realize I even owned it. It was made in the US and is a GTB, The new ones that Schiit supplies with the Freya are Russian built. They have to use tubes they can buy by the 100 and match for that preamp.

I have not tried 6f8g's that I recall.


----------



## CAPT Deadpool

Paladin79 said:


> I ordered the feet off of Amazon, if I can find the link I will send it to you later.
> 
> The vent cover is the inside of an old pocket watch, all brass I believe. I found it in a group of such things I bought on Ebay so it is pretty well one of a kind. Since I knew I was doing Steampunk, I bought lots of old watch parts and gears. Some of them I used in two copper and brass headphone stands I built. I traded some of those out and put in an Edison light that you can nearly make out in the photo. Originally I just had a hole in the top plate and copper mesh under it to allow for ventilation. There are plenty of gaps in the pocket watch to allow air flow.
> 
> ...



They require another adapter too if you want to connect the terminal on the top of the tube, it frees up pin 1 in the base for a shield and has a classic bottlehead shape.


----------



## Paladin79

Ah I have seen those as I recall, I need to run but I will be around later.


----------



## larcenasb

I am a HUGE fan of 6F8G tubes! If you guys like the 6SN7GT, the next step would definitely be to start treasure hunting for 6F8Gs. They sound just as good as 6SN7s; some even say better but it's hard for me to say something like that so easily without scientific testing. The real advantage is that a lot of times you can find the 6F8G for less because they aren't as in demand as 6SN7s. They are the precursor to 6SN7s though, in fact I have an RCA 6F8G that was from 1937...so amazing to me. The 6SN7 is easier to start with though because they're less susceptible to microphonics (in my experience). That said, the 6F8G is no more microphonic than the 6AS7G...so it's all worth it.

This may sound strange at first, but I LOVE that the Crack uses the 12AU7 at 6.3V, I wouldn't change it. This is because I find it's much easier to use an adapter with the octals, rather than plugging in a cumbersome 6F8G right into the amp. I can easily pull out the 6F8G with the adapter and roll different ones into the socket _away from the amp_...much easier handling and tube rolling. There's just so many options with the 12AU7 socket...can easily plug in a 12BH7, and can find many different adapters for octals...it's perfect for this flexibility. Plus the adapter acts as a pedestal, or a kingly throne, for these wonderful tubes. 

If any of you are interested in learning more about the octals' sound, I did a pretty in-depth comparison of the many 6SN7GTs and 6F8Gs I have. Here's the link: https://www.head-fi.org/threads/6sn...of-wwii-era-octal-tubes.890205/#post-14521083

Cheers!


----------



## wwmhf

Paladin79 said:


> Listening to a set of Tung Sols in the Crack, I am suddenly a huge fan of 6SN7's but most of you probably know about them. Feeding the Crack from a Schiit Gungnir multibit DAC and a Freya preamp just to allow some easy switching and a bit more tube sound. Tung Sol 6sn7's in that as well. I own ten or more headphone amps but always find myself returning to the Crack, I love this amp.



I envy you to have that big box of CRACK!


----------



## Paladin79

wwmhf said:


> I envy you to have that big box of CRACK!



I like the extra room for installing upgrades and the three pounds of copper plate and one inch thick quartered oak give me really good stability, less chance of microphonics.


----------



## Plazmodia

For those of you who got on the cracktober sale, you're in for a treat! I went for it last year, and it has been one of the most fun experiences to make. Not to mention that it sounds amazing. I have mine paired with the well-known HD 650 with a Topping D30. 

I got the speedball upgrade, but after all this time I haven't installed it. Do you guys think it's really worth adding? What other additions would you consider to be must-haves for your Crack?


----------



## attmci

Plazmodia said:


> For those of you who got on the cracktober sale, you're in for a treat! I went for it last year, and it has been one of the most fun experiences to make. Not to mention that it sounds amazing. I have mine paired with the well-known HD 650 with a Topping D30.
> 
> I got the speedball upgrade, but after all this time I haven't installed it. Do you guys think it's really worth adding? What other additions would you consider to be must-haves for your Crack?


Tom, I have a problem!


----------



## KcMsterpce

There are some beautiful Cracks in here. I have two myself. One with Speedball, the other without. I attempted to apply a finish to the wood, but since I'm a n00b at coating wood, I choose not to attempt it on the Mainline. The Cracks are simple and fun builds, and the cost (especially during the sales) is well beyond respectable for the performance.
I find the perfect marriage is when they are used with the Sennheiser HD650. I have listened to AKG K702/Q701, DT770 (250ohm), DT880 (250ohm), and several other headphones, but I usually end up going back to the HD650s.


----------



## CAPT Deadpool

KcMsterpce said:


> There are some beautiful Cracks in here. I have two myself. One with Speedball, the other without. I attempted to apply a finish to the wood, but since I'm a n00b at coating wood, I choose not to attempt it on the Mainline. The Cracks are simple and fun builds, and the cost (especially during the sales) is well beyond respectable for the performance.
> I find the perfect marriage is when they are used with the Sennheiser HD650. I have listened to AKG K702/Q701, DT770 (250ohm), DT880 (250ohm), and several other headphones, but I usually end up going back to the HD650s.


I notice your crack goes up to 11!


----------



## attmci

All crack lovers, I am wondering if we can use this kind of metal steel cover to shield the Crack transformer. 

https://www.ebay.com/itm/Metal-Stee...ull-up-cover-for-tube-amplifier-/142174801727

The crack transformer is naked.............and it is too close to the power tube which may cause some problems at some times. (Yes, I know its "special" design).


----------



## CAPT Deadpool

attmci said:


> All crack lovers, I am wondering if we can use this kind of metal steel cover to shield the Crack transformer.
> 
> https://www.ebay.com/itm/Metal-Stee...ull-up-cover-for-tube-amplifier-/142174801727
> 
> The crack transformer is naked.............and it is too close to the power tube which may cause some problems at some times. (Yes, I know its "special" design).



I think it would work if you're having a problem.  I'm separating my PSU from the audio portions due to some upgrades and space issues.


----------



## attmci

CAPT Deadpool said:


> I think it would work if you're having a problem.  I'm separating my PSU from the audio portions due to some upgrades and space issues.


For Crack? Some Pics?

Thx!


----------



## rlXX

Plazmodia said:


> For those of you who got on the cracktober sale, you're in for a treat! I went for it last year, and it has been one of the most fun experiences to make. Not to mention that it sounds amazing. I have mine paired with the well-known HD 650 with a Topping D30.
> 
> I got the speedball upgrade, but after all this time I haven't installed it. Do you guys think it's really worth adding? What other additions would you consider to be must-haves for your Crack?



I only added the Speedball to my build (so far  ). However, having listened to it before and after the speedball upgrade, I would definitely recommend upgrading your crack. It definitely adds to the sound. Also, I loved assembling the crack and by adding the Speedball, I had further tasks to complete.

Cheers


----------



## rlXX

Also, just wondering: I am looking to roll some tubes with my Bottlehead Crack. Is there any discussion on head-fi with recommendations to begin with? I am currently rocking the russian combination but would love to switch it up.

Thanks


----------



## JamieMcC

rlXX said:


> Also, just wondering: I am looking to roll some tubes with my Bottlehead Crack. Is there any discussion on head-fi with recommendations to begin with? I am currently rocking the russian combination but would love to switch it up.
> 
> Thanks



Have a read through this link, while the pics no longer show they are easy googled for an image. Its probably the most comprehensive review you will find on rolling tubes in the Crack.

http://the-key.enix.org/~krystal/review-tube-bottlehead.html


----------



## rlXX

JamieMcC said:


> Have a read through this link, while the pics no longer show they are easy googled for an image. Its probably the most comprehensive review you will find on rolling tubes in the Crack.
> 
> http://the-key.enix.org/~krystal/review-tube-bottlehead.html



Perfect. Just what i was looking for. Cheers!


----------



## attmci (Nov 15, 2018)

rlXX said:


> Also, just wondering: I am looking to roll some tubes with my Bottlehead Crack. Is there any discussion on head-fi with recommendations to begin with? I am currently rocking the russian combination but would love to switch it up.
> 
> Thanks


More active discussion here. Crack can take a lot of tubes. A lot of. The best power tubes for the crack is a couple of 6bl7/6bx7.

https://bottlehead.com/smf/index.php?topic=663.0


----------



## rlXX

attmci said:


> More active discussion here. Crack can take a lot of tubes. A lot of. The best power tubes for the crack is a couple of 6bl7/6bx7.
> 
> https://bottlehead.com/smf/index.php?topic=663.0



Great. Even more stuff to read. Thank you guys.


----------



## proto65

two questions regarding the crack. First what headphones do you recommend that are not similar to the hd 6xx and that work well with the crack? I was currently looking at AKG K240 Sextett. Also I am trying to get into tube rolling on the crack as well, should I go for a tung sol 7236 or Winged C or something entirely different?


----------



## adydula

Anything with an impedance of 250 ohms or higher.....

The stock tubes will work just fine..

Alex


----------



## proto65

adydula said:


> Anything with an impedance of 250 ohms or higher.....
> 
> The stock tubes will work just fine..
> 
> Alex


I am aware of the impedance, but I was looking for more specific recommendations on interesting tube and headphone choices.


----------



## adydula

Take a look at the bottlehead forum at bottlehead.com
They have a very good thread on this and many stories, experiences and selections....

Headphones, I use Beyer T90, T1's and HD600's,,,,all work very well my favorite right now is the HD600's.


----------



## Jim Spec

I have two Cracks. One highly modified including Speedball and one with NO modifications - NO Speedball.  I have used a 6F8G and a 6C8G as a power tube on the Crack with no modifications (IT WILL NOT WORK ON A CRACK WITH SPEEDBALL).  I believe it provides a much smoother tube-like sound even competing well with the Speedball Crack.  Add an 8 to 9 pin converter and it can also be used as a driver tube.  The best of the lot is the Tung-Sol 6F8G.


----------



## buke9

It’s been a while so broke out the Sextetts and fired up the Crack ( non Speedball) and not bad at all. Using a Tung Sol 6080 Chatham with a stock input tube this one is a Baldwin piano tube all the power the 240’s need.


----------



## Jim Spec

I am currently listening to the modified crack using a GE 6080 with a chrome metal base (the only one I have ever seen).  I am using an 8SN7GTB Sylvania (less current than 6sn7) with an eight to nine pin adapter.  It calms the 6080 and produces wide sound stage.  I am using Sennheiser HD800S for listening.  I like the sound of the 8SN7 and it is cheaper than the 6SN7.  As people find out about this sleeper, the tube will, like others, go up in price.


----------



## Sound Trooper

Just got my crack+speedball completed, and man.. does this amp pack a punch!

First impressions are definitely positive, but I’ll let it run in further before settling down for a serious listen.


----------



## joaogma

Im considering the Crack (and potentially Speedball) for my HD650. I mainly listen to some old school hiphops. Is the crack good for bass reproduction and extension?


----------



## DavidA

joaogma said:


> Im considering the Crack (and potentially Speedball) for my HD650. I mainly listen to some old school hiphops. Is the crack good for bass reproduction and extension?


Yes, but you should also remember that tubes used do make a difference in how it sounds so I'd budget for some alternative tubes to try.


----------



## cobrabucket (Dec 5, 2018)

joaogma said:


> Im considering the Crack (and potentially Speedball) for my HD650. I mainly listen to some old school hiphops. Is the crack good for bass reproduction and extension?


I really like the Tung-Sol 7236 as my power tube for quality bass extension [Hip-Hop, EDM. etc.] Other tube is a Sylvania 7N7 w. adapter. Love this combo with my 6XX!!! The Winged-C was good as well, but couldn't match the punchy low end of the 7236.


----------



## attmci (Dec 4, 2018)

cobrabucket said:


> I really like using a Tung-Sol 7236 as the driver to get excellent bass. Other tube is a Sylvania 7N7 w. adapter. Love this combo with my 6XX!!! The Winged-C was good as well, but couldn't match the quality low end of the 7236.


7236 is a power tube. There are special 7n7 tube available (Frankies).


----------



## cobrabucket

attmci said:


> 7236 is a power tube. There are special 7n7 tube available (Frankies).


Yes, I use 7236 as power tube and use a 7N7 to 12AU7 adapter for the other tube!


----------



## Sound Trooper (Dec 5, 2018)

I've spent a bit more time with the BH crack+SB and found that it is a really good match with the HD6XX and HD58X. Using the A&K SPKM as a source, I'm starting to understand why are there so many recommendations of the BH Crack + HD6XX combination on the forums. The highs are effortless while non fatiguing, the mids are smooth and holographic and the lows are satisfyingly full as well. With the 58X, highs come off a little more exciting and the lows hit slightly harder, however it does lose some of those romantic mids the 6XX are capable of. 

I'm now starting to think of what other tube combinations to roll to improve sound, but as it stands, the stock BH crack+SB+HD6XX/58X is pretty much hard to beat. 

Besides the 6XX and 58X, I have also tried the ZMF Auteurs with the BH crack+SB. I do get plenty of volume out of the BH crack with the Auteurs but somehow i feel that the mids are too forward and the lows are not satisfying enough. Its like some of the ZMF Auteur magic is gone with this combination. To me, the Auteur sounds best out of the Glenn's EL3N amp!


----------



## cobrabucket (Dec 5, 2018)

Sound Infinity said:


> I've spent a bit more time with the BH crack+SB and found that it is a really good match with the HD6XX and HD58X. Using the A&K SPKM as a source, I'm starting to understand why are there so many recommendations of the BH Crack + HD6XX combination on the forums. The highs are effortless while non fatiguing, the mids are smooth and holographic and the lows are satisfyingly full as well. With the 58X, highs come off a little more exciting and the lows hit slightly harder, however it does lose some of those romantic mids the 6XX are capable of.
> 
> I'm now starting to think of what other tube combinations to roll to improve sound, but as it stands, the stock BH crack+SB+HD6XX/58X is pretty much hard to beat.
> 
> Besides the 6XX and 58X, I have also tried the ZMF Auteurs with the BH crack+SB. I do get plenty of volume out of the BH crack with the Auteurs but somehow i feel that the mids are too forward and the lows are not satisfying enough. Its like some of the ZMF Auteur magic is gone with this combination. To me, the Auteur sounds best out of the Glenn's EL3N amp!


I thought the 58X would not be a good match seeing as it's only 150 ohms? My understanding is it's preferred to use phones with 250+. I was considering getting a 58X but would like to ideally get something that plays nice with the Crack. Thoughts? I'd like to check out some more pairings with this amp, but my current line-up doesn't look to have any high impedance options. Suggestions? Was looking at DT 1990's but that might be out of my range atm. Maybe 770s? Any folks use these with the Crack?


----------



## Sound Trooper

cobrabucket said:


> I thought the 58X would not be a good match seeing as it's only 150 ohms? My understanding is it's preferred to use phones with 250+. I was considering getting a 58X but would like to ideally get something that plays nice with the Crack. Thoughts? I'd like to check out some more pairings with this amp, but my current line-up doesn't look to have any high impedance options. Suggestions? Was looking at DT 1990's but that might be out of my range atm. Maybe 770s? Any folks use these with the Crack?



I think the 58X pairs very nicely with the BH crack, however I prefer the tone of the 6XX with the crack more. 

Actually the 58X pairs really nicely with the ifi nano BL as well.


----------



## cobrabucket

Sound Infinity said:


> I think the 58X pairs very nicely with the BH crack, however I prefer the tone of the 6XX with the crack more.
> 
> Actually the 58X pairs really nicely with the ifi nano BL as well.


I have a pair of Beyer 880 600Ohms on the way. Can't wait! I will probably end up the 58X, too...


----------



## attmci

Sound Infinity said:


> I've spent a bit more time with the BH crack+SB and found that it is a really good match with the HD6XX and HD58X. Using the A&K SPKM as a source, I'm starting to understand why are there so many recommendations of the BH Crack + HD6XX combination on the forums. The highs are effortless while non fatiguing, the mids are smooth and holographic and the lows are satisfyingly full as well. With the 58X, highs come off a little more exciting and the lows hit slightly harder, however it does lose some of those romantic mids the 6XX are capable of.
> 
> I'm now starting to think of what other tube combinations to roll to improve sound, but as it stands, the stock BH crack+SB+HD6XX/58X is pretty much hard to beat.
> 
> Besides the 6XX and 58X, I have also tried the ZMF Auteurs with the BH crack+SB. I do get plenty of volume out of the BH crack with the Auteurs but somehow i feel that the mids are too forward and the lows are not satisfying enough. Its like some of the ZMF Auteur magic is gone with this combination. To me, the Auteur sounds best out of the Glenn's EL3N amp!


Hi, I believe you have better amps according to other threads.


----------



## attmci

Anyone else had tried a pair of 6BL7/6BX7 as power tubes on the crack? I highly recommend it.

Be careful, you can only use 12au7 with this set-up.


----------



## cobrabucket

attmci said:


> Anyone else had tried a pair of 6BL7/6BX7 as power tubes on the crack? I highly recommend it.
> 
> Be careful, you can only use 12au7 with this set-up.


Any particular brands you'd recommend? And would a 6BL7/6BX7 work if there was a 7n7 to 12au7 adapter?


----------



## attmci (Jan 21, 2019)

cobrabucket said:


> Any particular brands you'd recommend? And would a 6BL7/6BX7 work if there was a 7n7 to 12au7 adapter?


No brands preference on Crack.

NO, you cannot use a 7N7 (0.64A, similar to a 6SN7, limited by the Crack transformer).


----------



## cobrabucket (Dec 19, 2018)

attmci said:


> No brands preference on Crack.
> 
> NO, you cannot use a 7N7 (0.6A, similar to a 6SN7, limited by the Crack transformer).


I'm currently running my BHC with a Tung Sol 7236 and a Sylvania 7n7 with an adapter [7n7 to 12au7]. Is this combo ok? I think it sounds fantastic, but don't want to damage anything! I am guessing this is safe normally, but the set-up you mentioned with the 6BL7 would change the power parameters to make using the adapter unsafe?


----------



## attmci (Jan 21, 2019)

cobrabucket said:


> I'm currently running my BHC with a Tung Sol 7236 and a Sylvania 7n7 with an adapter [7n7 to 12au7]. Is this combo ok? I think it sounds fantastic, but don't want to damage anything! I am guessing this is safe normally, but the set-up you mentioned with the 6BL7 would change the power parameters to make using the adapter unsafe?



It's safe to use a pair of 6BL7 with one 12AU7/ECC82/7316.

If you like 7236, you will like this combo. 

BTW, your current setting is safe.


----------



## Quadfather

I am going fully portable, so I put this up...

https://www.head-fi.org/threads/bot...cable-heavy-duty-power-cable-included.895106/


----------



## attmci

https://www.head-fi.org/threads/6sn...of-wwii-era-octal-tubes.890205/#post-14521498

Nice review of rolling driver tubes on a Crack.


----------



## Ultrainferno

On the last day of the year we're giving away a Bottlehead Crack 1.1 DIY headphone amplifier kit! Everyone can join, world wide entries allowed. Good luck

https://www.headfonia.com/giveaway-16-bottlehead-crack/


----------



## Tin Trinh

Hello every one , im going upgrade bottlehead crack 1.1 for my hd650 , so what dac can i use with my desktop ? . Thanks


----------



## attmci

Tin Trinh said:


> Hello every one , im going upgrade bottlehead crack 1.1 for my hd650 , so what dac can i use with my desktop ? . Thanks


All DACs work. What's the price range?


----------



## Tin Trinh

attmci said:


> All DACs work. What's the price range?


Hello , around 100 to 150 usd, is the schiit modi work ?


----------



## SMDEE

Tin Trinh said:


> Hello , around 100 to 150 usd, is the schiit modi work ?



Yes, I have the Modi 3 and it works well with my Crack and HD650 headphones.


----------



## Paladin79

I use another Schiit multibit with mine but it is out of that price range, I run Gumby to Freya to Crack.  All 6sn7 tubes except for a Tung Sol 5998, I did away with the 12AU7 some time ago.


----------



## Tin Trinh

SMDEE said:


> Yes, I have the Modi 3 and it works well with my Crack and HD650 headphones.


Yeah thanks you ill try that.


Paladin79 said:


> I use another Schiit multibit with mine but it is out of that price range, I run Gumby to Freya to Crack.  All 6sn7 tubes except for a Tung Sol 5998, I did away with the 12AU7 some time ago.


Love it , hope to upgrade soon , i go with modi 3 first thank you.


----------



## attmci

Copy from the bottlehead: 

"I misread some of the comments here and plugged my VT-231 into the output socket (of the Crack) and listened away. I actually had a few hours on it before I figured it out. Nothing exploded and it sounded OK to me except a very slight flange effect sound in the mids, but I figured it's old, actually a really old sample. Anyway, I'm wondering what's the harm in continuing to use it as the output from time to time? I've since rolled my 6as7's in and out and the amp's fine."
Paul:
"Someone else did this a while ago and tried to argue that there was no problem.  I went through the laundry list of problems that you'll run into if you do this, but the post is proving to be a little elusive to find.

It's not surprising that nothing happened that immediately.  What you're doing would be like going out and starting your car, then putting a cinder block on the gas pedal and walking away.  Will your car still run for a while?  Probably so, but you can expect imminent destruction in a far shorter time period compared to normal use.

The amp also isn't designed for the 6SN7 to plug into that socket.  The 6SN7 would be a poor choice overall for this position, so it's not like a moderate amount of tweaking would make the 6SN7 work in place of the 6080.  They are very, very different tubes made for completely different purposes."


----------



## Paladin79

The 6sn7 with adapter is a great choice to use in place of the 12Au7 or equivalent. I rarely use anything else since being exposed to this solution.


----------



## attmci

Paladin79 said:


> The 6sn7 with adapter is a great choice to use in place of the 12Au7 or equivalent. I rarely use anything else since being exposed to this solution.


Tom, the guy used 6SN7GT as power tube.


----------



## Paladin79 (Feb 12, 2019)

attmci said:


> Tom, the guy used 6SN7GT as power tube.



Yeah I saw that, I was just saying with adapter it is a good choice for the driver tube, IMHO or the loktal version the 7N7. (The tall version of that tube, in action here.)


----------



## Maxhawk (Feb 25, 2019)

A while back I made a board for the Crack with a switch that changes the bias resistors for optimal current for 12AU7, E80CC, and 12BH7 tubes. This replaces the Speedball current source board and mounts to the existing standoffs. Here is my original post. I ordered some new boards to have on hand for future projects and I'm offering my remaining bare boards for $6.00 shipped in the US ($10.00 international for most countries -- will need to confirm actual shipping charge depending on destination). PM me if you're interested.






The new boards are blue:


----------



## bloodhawk (Feb 24, 2019)

Maxhawk said:


> A while back I made a board for the Crack with a switch that changes the bias resistors for optimal current for 12AU7, E80CC, and 12BH7 tubes. I continue to get requests so I decided to get more boards made and offer them to the community. Here is my original post for the board I made. I'm offering bare boards for $6.00 shipped in the US ($10.00 international for most countries) and if there's enough interest in kits, I can buy parts in quantity to get a discount. I'm thinking +$10 with parts. So, $16 shipped in the US and $20 for int'l for kits.
> 
> 
> 
> ...




These are totally worth it! And add so much more value to the crack and expand the tube rolling options!

Had them in my Crack build from some time back - 



Spoiler


----------



## attmci

bloodhawk said:


> These are totally worth it! And add so much more value to the crack and expand the tube rolling options!
> 
> Had them in my Crack build from some time back -
> 
> ...


Have u tried to use the Dave to drive the Crack?


----------



## bloodhawk

attmci said:


> Have u tried to use the Dave to drive the Crack?



Did try it a few times, but didn't really find any audible change vs the Dx7s which is what i was using the crack with.


----------



## Paladin79

My favorite tubes in the Crack to date. Tung Sol 5998 and a Russian 1578 (6sn7 equivalent) Melz plant. Another interesting driver tube can be the 7N7 tall body loktal, but this 6sn7 equivalent is on a par with the 1940's grey glass RCA tubes IMHO and a total winner.


----------



## proto65

I am about to pull the trigger and buy two little upgrades for the crack, the Triad C7-X, and the cree schottky diodes. I have only seen them installed on post speedball cracks but I assume they work fine with pre speedball cracks, is that correct? Also for installing the triad, I desolder this 270 resistor and solder the triad in its place, right? Lastly does the orientation of the triad matter because I have seen photos of it installed both ways?


----------



## attmci

bloodhawk said:


> Did try it a few times, but didn't really find any audible change vs the Dx7s which is what i was using the crack with.


Thanks for the quick response. I always want to try my better DAC on the Crack, but haven't got a chance. Now I believe a better Dac needs a better Amp to scale up, and *vice versa.*


----------



## attmci

Paladin79 said:


> My favorite tubes in the Crack to date. Tung Sol 5998 and a Russian 1578 (6sn7 equivalent) Melz plant. Another interesting driver tube can be the 7N7 tall body loktal, but this 6sn7 equivalent is on a par with the 1940's grey glass RCA tubes IMHO and a total winner.


Looks great, Tom.


----------



## Paladin79 (Feb 24, 2019)

Thanks, I was about to mention the DX7S is not a bad DAC, I was involved with some tests recently with 20 pretty expensive DACS and the Topping came in at number 6, it rated higher than some DACs costing 10 times more. I use the DX7 with my Crack on occasion but usually it his hooked to a Freya/Gumby combo.

Oops sorry, my only point should have been the Crack can sound pretty good with a DX7S.


----------



## bloodhawk

attmci said:


> Thanks for the quick response. I always want to try my better DAC on the Crack, but haven't got a chance. Now I believe a better Dac needs a better Amp to scale up, and *vice versa.*



Definitely. I got the Dave for a steal of a price with the stand, that's why I bought it. Otherwise, i would have never even thought of getting one. I'm definitely not a believer in super high-end DAC's.

The Crack in itself makes the output from any DAC a total treat to listen to.


----------



## Tom-s

Just a heads-up! There's a Crack sale coming this weekend!

Even with a Mainline and S3X, what i said a year ago still stands:


Tom-s said:


> Crack's been my first DIY kitbuild. I learned to solder by building Crack.
> Thanks to the superb manual, even with skill-level 0, Crack is a safe bet.
> Be confident, you can build it.
> For the money, and how it taught me a lot about how audio, tubes and stuff works (all, that standard, of the shelf stuff didn't) it is probably the best amplifier i ever bought and ever will buy.
> ...


----------



## SilverEars

I tried the RCA 6AS7 tube, and prefer the stock tube.  Stock tube just sounds better.


----------



## audiowize

SilverEars said:


> I tried the RCA 6AS7 tube, and prefer the stock tube.  Stock tube just sounds better.


Some Cracks ship with RCA 6AS7G tubes.


----------



## SilverEars (Feb 28, 2019)

audiowize said:


> Some Cracks ship with RCA 6AS7G tubes.


Didn't know.

If that's the case then I prefer the Raytheon Registered tube.


----------



## SilverEars

The tube I'm liking is the Raytheon CK6080.  I've only tried two tubes with the crack, RCA 6AS7G and Raytheon CK6080.  I definitely prefer the Raytheon CK6080.  

This is how it looks like.


----------



## Mak333 (Mar 7, 2019)

I'm not sure what it is, but I've tried a Russian 6H13CC 8702 winged tube, and also an RCA 6AS7G tube, and they sound fairly bright.  Don't get me wrong, they have more detail and separation than the stock Tung-Sol 6080 tube I received with the kit, but they are just too bright for me, even when using input tubes that aren't bright.  Almost hurts my ears actually. 

I've only been listening with Sennheiser HD-600s, and this amp for about 9 years now with not much tube rolling other than the aforementioned, but the stock 6080 output is what really sounds best to me in terms of longer listening sessions.  Other output tubes in the 6AS7G variant are rather fatiguing to me in this specific amp.


----------



## attmci

Mak333 said:


> I'm not sure what it is, but I've tried a Russian 6H13CC 8702 winged tube, and also an RCA 6AS7G tube, and they sound fairly bright.  Don't get me wrong, they have more detail and separation than the stock Tung-Sol 6080 tube I received with the kit, but they are just too bright for me, even when using input tubes that aren't bright.  Almost hurts my ears actually.
> 
> I've only been listening with Sennheiser HD-600s, and this amp for about 9 years now with not much tube rolling other than the aforementioned, but the stock 6080 output is what really sounds best to me in terms of longer listening sessions.  Other output tubes in the 6AS7G variant are rather fatiguing to me in this specific amp.


This?


----------



## Mak333

attmci said:


> This?


Basically, yes.  Mine has the JAN-CTL-6080 designation.  62-16.  I'm assuming that's a date code?  Year and week of year?  1962, 16th week?


----------



## attmci (Mar 8, 2019)

Mak333 said:


> Basically, yes.  Mine has the JAN-CTL-6080 designation.  62-16.  I'm assuming that's a date code?  Year and week of year?  1962, 16th week?


Correct.

This is a rare tube, and the one on the left sounds similar to the Bendix 6080WB with Graphite Plates.


----------



## cebuboy

Hello, are capacitor upgrades worth it? Those film caps I see you guys using here are $$$ and how does bypass caps help in the sound? So far the stock crack with speedball and alps pot + rca cleartop 12AU7 and Svetlana 6H5C sounds great with the HD650.


----------



## bloodhawk

cebuboy said:


> Hello, are capacitor upgrades worth it? Those film caps I see you guys using here are $$$ and how does bypass caps help in the sound? So far the stock crack with speedball and alps pot + rca cleartop 12AU7 and Svetlana 6H5C sounds great with the HD650.



The super expensive ones are not really worth it. 

The cheaper / vfm film caps help noticeably.


----------



## SilverEars (Mar 8, 2019)

Mak333 said:


> I'm not sure what it is, but I've tried a Russian 6H13CC 8702 winged tube, and also an RCA 6AS7G tube, and they sound fairly bright.  Don't get me wrong, they have more detail and separation than the stock Tung-Sol 6080 tube I received with the kit, but they are just too bright for me, even when using input tubes that aren't bright.  Almost hurts my ears actually.
> 
> I've only been listening with Sennheiser HD-600s, and this amp for about 9 years now with not much tube rolling other than the aforementioned, but the stock 6080 output is what really sounds best to me in terms of longer listening sessions.  Other output tubes in the 6AS7G variant are rather fatiguing to me in this specific amp.


I didn't find the RCA 6AS7G bright sounding (at least not more so than the Raytheon CK6080).  I thought it was smoother sounding than the Raytheon CK6080.  A bit less clear, smoother and a bit blended in smoothness for imaging (so not as distinct sounds).  CK6080 had better clarity and imaged better with more bite/peak to the treble presence.


----------



## SilverEars

Have you guys noticed differences between the different 6080?  I personally liked couple of 6080 tubes I've tried, and wondering if there are differences in sound between the different 6080 tubes.

What is yall's top sounding tubes?


----------



## attmci

SilverEars said:


> Have you guys noticed differences between the different 6080?  I personally liked couple of 6080 tubes I've tried, and wondering if there are differences in sound between the different 6080 tubes.
> 
> What is yall's top sounding tubes?


Here,  for power tubes,
https://bottlehead.com/smf/index.php?topic=663.465


----------



## Paladin79 (Mar 8, 2019)

SilverEars said:


> Have you guys noticed differences between the different 6080?  I personally liked couple of 6080 tubes I've tried, and wondering if there are differences in sound between the different 6080 tubes.
> 
> What is yall's top sounding tubes?



My top sounding tubes are a Chatham 6080, Tung Sol 5998, and a NOS RCA 6AS7G for power tubes.

for driver tube it is the Melz 1578 (6sn7) with appropriate adapter, a couple 7n7 tall bodies which are Loktals (another adapter), and twin Sylvania 6J5's as shown in the photo. This is a single triode arrangement that is a sub for a 6sn7 which has twin triodes built in. It might be more complex than what you are looking for but these old Sylvania tubes have an excellent SQ. NOS RCA 6as7G in the background. I am going to do some work with adapters so they match the theme of my amp so this is a work in progress right now.


----------



## penguinofsleep2

Has anyone noticed a significant difference in sound with different solder being used? I imagine no but I'm sure we've all been surprised before.


----------



## bloodhawk

penguinofsleep2 said:


> Has anyone noticed a significant difference in sound with different solder being used? I imagine no but I'm sure we've all been surprised before.


Nope, dont waste money on that stuff. Just get good quality solder from a company like Kester, MGChemicals , etc


----------



## adydula

Zip. Zero, Nada...dont waste your money !!!


----------



## penguinofsleep2

Awesome thanks guys.


----------



## CAPT Deadpool

https://www.amazon.com/gp/product/B0149K4JTY/ref=oh_aui_search_asin_title?ie=UTF8&psc=1

Recommend a leaded solder 63 Sn (Tin), 37 Pb (lead) with flux core.  63/37 is eutectic making it easier to work with.


----------



## L0rdGwyn (Mar 13, 2019)

SilverEars said:


> Have you guys noticed differences between the different 6080?  I personally liked couple of 6080 tubes I've tried, and wondering if there are differences in sound between the different 6080 tubes.
> 
> What is yall's top sounding tubes?



I've rolled a lot of tubes through my Crack(atwoa).

There are differences between the 6080's, but they are more subtle then going from a 6080 to something like, say, a 5998.

IMO, the two best 6080's I have heard are the Mullard CV2984 and the Tung Sol 6080 (not to be confused with the Chatham rebrand or other rebrands)

In terms of the BEST output tubes in the Crack, here is what I have at the top of my list:

Tung Sol 7802 = Western Electric 421A > Tung Sol 421A > Tung Sol 5998 > Mullard CV2984 = Tung Sol 6080 > everything else I have (Tung Sol 6AS7G, Bendix 6080WB, Chatham 6080WB, Sylvania 6080WC...that might be it)

Granted, I haven't listened to a lot of the tubes on the bottom of that list in quite a while.



Mak333 said:


> Basically, yes.  Mine has the JAN-CTL-6080 designation.  62-16.  I'm assuming that's a date code?  Year and week of year?  1962, 16th week?



Neither of the above tubes is a "true" Tung Sol 6080, the one on the left is a Chatham rebrand.  Not sure of the right, but I suspect other rebrand.

The Tung Sol 6080 has silver support rods and should have the "322" Tung Sol factory code, see below.


----------



## L0rdGwyn

By the way, is this a better place to discuss the Crackatwoa?  There is another BH thread, but it doesn't get much action sadly  and I am a Crack(atwoa) head.


----------



## attmci (Mar 13, 2019)

L0rdGwyn said:


> I've rolled a lot of tubes through my Crack(atwoa).
> 
> There are differences between the 6080's, but they are more subtle then going from a 6080 to something like, say, a 5998.
> 
> ...



Sounds like a _*Crack(atwoa)*_ is quite different than a regular _*Crack*_. 

The Bendix 6080WB sounds great on a Crack.

But everyone has their own tastes and preferences.


----------



## L0rdGwyn (Mar 13, 2019)

attmci said:


> Sounds like a _*Crack(atwoa)*_ is quite different than a regular _*Crack*_.
> 
> The Bendix 6080WB sounds great on a Crack.
> 
> But everyone has their own tastes and preferences.



Nah, the same rules apply, just a matter of preference.  I've tried several times to find the appeal in the Bendix, especially since I paid a pretty penny for it.  I think I haven't been able to get over how collapsed the soundstage feels compared to something like the WE 421A or TS 7802.

Maybe I need to reevaluate my priorities and give it another try


----------



## attmci

L0rdGwyn said:


> Nah, the same rules apply, just a matter of preference.  I've tried several times to find the appeal in the Bendix, especially since I paid a pretty penny for it.  I think I haven't been able to get over how collapsed the soundstage feels compared to something like the WE 421A or TS 7802.
> 
> Maybe I need to reevaluate my priorities and give it another try


TBH, the Crack don't deserve any tube cost more than $60. So a couple of 6bl7/bx7 is your best  bet. I used to love those tubes like crazy.


----------



## SilverEars (Mar 24, 2019)

I wonder if they can design an amp identical sound characteristic of the Crack, but with much greater power and works well for low impedance headphones as well?  I do like how the amp images for the Sennheiser HD6 series (so interesting how the headphone images out of this). If I can get same imaging push for other cans of low impedance, it would be an interesting amp.

It just seems to have very good separation to sounds, outputting distinction in sounds for imaging. Good bass impact as well.  Surprises me how fast this tube amp is.

I'm wondering if the result is just pure luck from it's OTL output and HD6 series?!


----------



## attmci

SilverEars said:


> I wonder if they can design an amp identical sound characteristic of the Crack, but with much greater power and works well for low impedance headphones as well?  I do like how the amp images for the Sennheiser HD6 series (so interesting how the headphone images out of this). If I can get same imaging push for other cans of low impedance, it would be an interesting amp.
> 
> It just seems to have very good separation to sounds, outputting distinction in sounds for imaging. Good bass impact as well.  Surprises me how fast this tube amp is.
> 
> I'm wondering if the result is just pure luck from it's OTL output and HD6 series?!


You can try to ask Doc. B. if he can make you one.
LOL


----------



## adydula

Mainline?


----------



## adydula (Mar 25, 2019)

...and then there is the $10,000 head amp Doc has made...and will make you one if so desired!!


----------



## Makiah S

Firing up a Crack with Speedball for my first even listen to this product! Tube wise I've got a Psvanne 12au7 on output and... a French 6080a [Thomson CFS??]? There's two Jan Phillips that came with it but I can figure out what's different about each


----------



## Mightygrey

Mshenay said:


> Firing up a Crack with Speedball for my first even listen to this product! Tube wise I've got a Psvanne 12au7 on output and... a French 6080a [Thomson CFS??]? There's two Jan Phillips that came with it but I can figure out what's different about each


Welcome down the rabbit-hole! What cans are you using - 800s?


----------



## Paladin79

One of my latest builds, a headphone stand to match a bottlehead crack. I soon realized the tubes would have to be lit so I worked on that.The tubes are removable and replaceable. I like the ST series of tubes but a 6080 or even an EL 34 could work and on the other side 6sn7's and such.


----------



## L0rdGwyn

Anybody own both the HD600 and 650 paired with their Crack?  Oddly enough, I have owned every headphone from the family except the 600 (although I did have the HD580 at one time, arguably the same headphone, same driver).  I had it on loan for a short time and enjoyed the extra bight in the upper mids.  I LOVE the 650, it's a permanent member of the club.  Think it is worth owning both?  I am a committed Crackhead, almost seems like a rite of passage


----------



## DavidA

L0rdGwyn said:


> Anybody own both the HD600 and 650 paired with their Crack?  Oddly enough, I have owned every headphone from the family except the 600 (although I did have the HD580 at one time, arguably the same headphone, same driver).  I had it on loan for a short time and enjoyed the extra bight in the upper mids.  I LOVE the 650, it's a permanent member of the club.  Think it is worth owning both?  I am a committed Crackhead, almost seems like a rite of passage



I owned the HD600 along with the HD650, HD58X, HD6XX and had borrowed a friends HD660S: HD600 is the only one that I sold since with some tracks it was a bit sharp/sibilant to me due to the small peak in the 3.5-5khz range and I've found that my Ypsilon S1 does everything the HD600 does but without the small peak and is much easier to drive so it sounds better on most of my other gear.

@Paladin79, so create some of the most inspiring stuff around


----------



## L0rdGwyn (Apr 28, 2019)

DavidA said:


> I owned the HD600 along with the HD650, HD58X, HD6XX and had borrowed a friends HD660S: HD600 is the only one that I sold since with some tracks it was a bit sharp/sibilant to me due to the small peak in the 3.5-5khz range and I've found that my Ypsilon S1 does everything the HD600 does but without the small peak and is much easier to drive so it sounds better on most of my other gear.
> 
> @Paladin79, so create some of the most inspiring stuff around



Thanks David, we'll see if I find that area problematic.  I decided to go for it, open box pair for $210, great resell value if they aren't my thing.  A while back, I went on a deep dive down the Grado aftermarket driver rabbit hole, never tried the Elleven Acoustica stuff but wanted to, I had a custom Nhoord Red V2 set as well as a Symphones V8 pair I built, I was a big fan of the V8 driver, great low end, maybe I'll consider giving it another go sometime and try the Ypsilon.


----------



## DavidA

L0rdGwyn said:


> Thanks David, we'll see if I find that area problematic.  I decided to go for it, open box pair for $210, great resell value if they aren't my thing.  A while back, I went on a deep dive down the Grado aftermarket driver rabbit hole, never tried the Elleven Acoustica stuff but wanted to, I had a custom Nhoord Red V2 set as well as a Symphones V8 pair I built, I was a big fan of the V8 driver, great low end, maybe I'll consider giving it another go sometime and try the Ypsilon.


I got my HD600 a few years back for $210 brand new from Adorama IIRC, back friday sale?, ended up selling them to a friend for $200 a few months later and then my friend sold them for $240 on craig's list to fund a Ypsilon S2 build that I did for her which she still loves to this day.  I also have a Ypsilon R1 and had a G1 but ending up selling the G1 since it was so close to the R1,  Also built a few with Ypsilon S2 drivers for a few friends and they all love them.  Haven't heard the V8 yet but got to hear a V7 build by fleasbaby and it was impressive so I can imagine that the V8 might be pretty good also.  The only issue I had with the V7 was that it sounded better with L-pads versus the G-pads that I prefer so I haven't gotten around to doing a V8 build.  Also have a Nhoord Red V2 build that I use a lot since it sounds quite good on almost any gear including my Galaxy S9 (which is quite sound average IMO).  I'm like you that I love my Crack but aside from slightly better CAPs haven't done much mods to it but it does great for my needs as is.


----------



## L0rdGwyn (Apr 28, 2019)

DavidA said:


> I got my HD600 a few years back for $210 brand new from Adorama IIRC, back friday sale?, ended up selling them to a friend for $200 a few months later and then my friend sold them for $240 on craig's list to fund a Ypsilon S2 build that I did for her which she still loves to this day.  I also have a Ypsilon R1 and had a G1 but ending up selling the G1 since it was so close to the R1,  Also built a few with Ypsilon S2 drivers for a few friends and they all love them.  Haven't heard the V8 yet but got to hear a V7 build by fleasbaby and it was impressive so I can imagine that the V8 might be pretty good also.  The only issue I had with the V7 was that it sounded better with L-pads versus the G-pads that I prefer so I haven't gotten around to doing a V8 build.  Also have a Nhoord Red V2 build that I use a lot since it sounds quite good on almost any gear including my Galaxy S9 (which is quite sound average IMO).  I'm like you that I love my Crack but aside from slightly better CAPs haven't done much mods to it but it does great for my needs as is.



Oh yeah, headphones like the HD600/650/800 seem to never lose their resale value, they've earned their "classic" monikers after all.  That's quite the collection!  I'm sure fleasbaby is still churning out those beautiful wood cups.  I only ever used the V8 with the L pads which are most definitely less comfortable than the G pads.  Pretty sure the V8 were meant for either the S or L pad, but don't quote me, probably also sound good with the TTVJ flats but would make sense they don't play nice with the G's.  I want to build another set to wear around the house with my phone like you've done with your S9, gotta love how lightweight those builds are.  May be contacting fleasbaby soon...

Probably smart to stop where you did with the Crack, like everything in this hobby, diminishing returns kick in very quickly.

I did the opposite ha!  I had the Crack+SB originally, which I loved, didn't mod it but upgraded the tubes and the volume pot.  I liked it so much, I decided I wanted a Crack on...crack, so to speak lol.  I first compared it to the Felix Audio Espressivo with some high-quality tubes in both, figured it was worth testing other more expensive waters, but the Crack+SB blew the Espressivo away, IMO.

So, I sold the Crack+SB and did a brand new build with BH's Crackatwoa kit.  This time I added their stepped attenuator and the biggest, fanciest caps I could fit.  More tube upgrades, boutique components, etc. and now I am stuck with this beautiful monstrosity.  Let's just say, I am in it for the long haul.


----------



## meffisto

Those caps 

Guys i could need help.. im building my crack OTL with speedball, started saturday. My problem is i did DL both manuals at time i ordered kits. I m not able to find them now and not able to DL again. Found some on the net but its not the last version. There are some changes on AC slots.. I emailed bottlehead yersteday and should get an answer soon but if one of you has the pdf and could send it to me (antoinegplus at gmail . com) i would be really gratefull!!


----------



## donato

meffisto said:


> Those caps
> 
> Guys i could need help.. im building my crack OTL with speedball, started saturday. My problem is i did DL both manuals at time i ordered kits. I m not able to find them now and not able to DL again. Found some on the net but its not the last version. There are some changes on AC slots.. I emailed bottlehead yersteday and should get an answer soon but if one of you has the pdf and could send it to me (antoinegplus at gmail . com) i would be really gratefull!!



If you login to the bottlehead site and go into your orders, you'll be able to download your manuals there.


----------



## meffisto

donato said:


> If you login to the bottlehead site and go into your orders, you'll be able to download your manuals there.



its not working.. tried already.. i m told i ve reached the download limit for this file....


----------



## meffisto

meffisto said:


> Those caps
> 
> Guys i could need help.. im building my crack OTL with speedball, started saturday. My problem is i did DL both manuals at time i ordered kits. I m not able to find them now and not able to DL again. Found some on the net but its not the last version. There are some changes on AC slots.. I emailed bottlehead yersteday and should get an answer soon but if one of you has the pdf and could send it to me (antoinegplus at gmail . com) i would be really gratefull!!



Nobody got the manuals for me please?


----------



## L0rdGwyn

meffisto said:


> Nobody got the manuals for me please?



I would wait for Bottlehead's response.  You will hear from them more quickly if you create a post on the Bottlehead forum, that is typically where they operate for customer support, make a post here: https://bottlehead.com/smf/index.php?board=24.0


----------



## Blommen

So @L0rdGwyn would you say that the crack +SB is way better than the espressivo? I am thinking about getting a otl amp for my zmf Eikons, from the classifieds. 

A plus for me on the espressivo is the preamp function so I could hook it up to my vintage amp but if sq is much better on the crack then that kinda negates that plus.


----------



## L0rdGwyn

Blommen said:


> So @L0rdGwyn would you say that the crack +SB is way better than the espressivo? I am thinking about getting a otl amp for my zmf Eikons, from the classifieds.
> 
> A plus for me on the espressivo is the preamp function so I could hook it up to my vintage amp but if sq is much better on the crack then that kinda negates that plus.



Hey Blommen, yes that was my impression.  I compared the Crack+SB and the Espressivo, using higher-quality-than-stock tubes in both.  I believe I had a Mullard CV4003 input and Western Electric 421A output in the Crack+SB and Western Electric JW 2C51 input and Foton 6N6P-IR output in the Espressivo.  These are nearly the best tubes that can be put in each respective amp.

Of course, it all depends on what you value.  For me, the most immediate and high-priority item when comparing amps/tubes is airiness/staging/separation, which lends it self to detail-retrieval as well.  The Crack+SB was just more spacious, larger soundstage, and thus, more detailed sounding than the Espressivo with this setup.  The Espressivo had a much smaller stage, with sounds/instruments more on top of one-another.

Now if you can sacrifice some soundstage/air and detail for preamp out, that is your call!  But I could not overlook it.

Now you do not need a Western Electric 421A to get that airiness, a Tung Sol 5998 will get you 90% of the way there.  A decent 6SN7 with an adapter will also be an upgrade over a Mullard CV4003 in the driver position, IMO.

Hope that helps.


----------



## Blommen

L0rdGwyn said:


> Hey Blommen, yes that was my impression.  I compared the Crack+SB and the Espressivo, using higher-quality-than-stock tubes in both.  I believe I had a Mullard CV4003 input and Western Electric 421A output in the Crack+SB and Western Electric JW 2C51 input and Foton 6N6P-IR output in the Espressivo.  These are nearly the best tubes that can be put in each respective amp.
> 
> Of course, it all depends on what you value.  For me, the most immediate and high-priority item when comparing amps/tubes is airiness/staging/separation, which lends it self to detail-retrieval as well.  The Crack+SB was just more spacious, larger soundstage, and thus, more detailed sounding than the Espressivo with this setup.  The Espressivo had a much smaller stage, with sounds/instruments more on top of one-another.
> 
> ...



Thank you, that helps a lot! Those are qualities I value also, as my music is very "busy" (metal).

I guess I'll have to try it, won't I?


----------



## L0rdGwyn

Any Crackheads out there who prefer it without the Speedball? I admittedly did not give my old Crack a lot of time without it, but I do remember it having significantly more distortion and a more "gooey" tube sound.  The thought of buying another kit to build without adding the Speedball has crept into my mind lately


----------



## JamieMcC

I also have a hankering to revisit a non speedball crack I once owned. I've built six or seven Cracks in the past some stock some modded but the one that sticks in my mind was fitted with 3x30uf 160v Russian MGBO (paper in oil) plus a teflon bypass per channel and  a choked power supply. Just have this memory of beautiful textured midrange with GEC 6AS7G + 6SN7 gt. Not sure if I hd650 or T1 cans at the time, If I do another Crack it would certainly be along similar lines.

The caps were only a few $ each I remember preferring them to the  Mundorf 100uf Mcaps. Mind it was a few years back now.

https://www.ebay.co.uk/itm/30uF-160...m41cc79f78b:g:RAoAAOSw~kZZiWrf&frcectupt=true


----------



## L0rdGwyn

JamieMcC said:


> I also have a hankering to revisit a non speedball crack I once owned. I've built six or seven Cracks in the past some stock some modded but the one that sticks in my mind was fitted with 3x30uf 160v Russian MGBO (paper in oil) plus a teflon bypass per channel and  a choked power supply. Just have this memory of beautiful textured midrange with GEC 6AS7G + 6SN7 gt. Not sure if I hd650 or T1 cans at the time, If I do another Crack it would certainly be along similar lines.
> 
> The caps were only a few $ each I remember preferring them to the  Mundorf 100uf Mcaps. Mind it was a few years back now.
> 
> https://www.ebay.co.uk/itm/30uF-160...m41cc79f78b:g:RAoAAOSw~kZZiWrf&frcectupt=true



Interesting!  Those are some oddball capacitors, I'll have to look into them.  I haven't tried a ton of different caps, might be fun to do a Crack build with some cap rolling action.  Must be something to the non-speedballer if it stood out among that many Cracks.  Thanks for the link.


----------



## Jimmy24

L0rdGwyn said:


> Any Crackheads out there who prefer it without the Speedball? I admittedly did not give my old Crack a lot of time without it, but I do remember it having significantly more distortion and a more "gooey" tube sound.  The thought of buying another kit to build without adding the Speedball has crept into my mind lately



Hi L0rdGwyn. I made a Crack without Speedball recently for a client and there seemed to be a noticeable difference in the bass and the sound stage. I think you're right in that it sounds more distorted, but not necessarily in a bad way. It sounds more intimate to my ears with much more low end presence. However, the Speedball does give more clarity and a bit more air and space.


----------



## Wes S

L0rdGwyn said:


> Any Crackheads out there who prefer it without the Speedball? I admittedly did not give my old Crack a lot of time without it, but I do remember it having significantly more distortion and a more "gooey" tube sound.  The thought of buying another kit to build without adding the Speedball has crept into my mind lately


I actually just bought, a used kit, without speedball.  I plan to add the speedball, after i get a good feel for the normal crack.  I love warmth, and think I am going to love both versions.  I just scored a NIB Mullard ECC882 square getter, from Blackburn 57', so now I just need to find a 5998 power tube. . .I am looking forward to hearing what others have to say about, with and without speedball.


----------



## L0rdGwyn

Jimmy24 said:


> Hi L0rdGwyn. I made a Crack without Speedball recently for a client and there seemed to be a noticeable difference in the bass and the sound stage. I think you're right in that it sounds more distorted, but not necessarily in a bad way. It sounds more intimate to my ears with much more low end presence. However, the Speedball does give more clarity and a bit more air and space.



Hi Jimmy, that's helpful.  If memory serves, I think it is different enough to warrant a new build, thought having a more "tubey" Crack could be fun.  I also just have the urge to break out the soldering iron again   thanks for your impressions.



Wes S said:


> I actually just bought, a used kit, without speedball.  I plan to add the speedball, after i get a good feel for the normal crack.  I love warmth, and think I am going to love both versions.  I just scored a NIB Mullard ECC882 square getter, from Blackburn 57', so now I just need to find a 5998 power tube. . .I am looking forward to hearing what others have to say about, with and without speedball.



That is a good approach.  Some out there like the original enough that they never add the Speedball, you never know!  As Jimmy said above, the SB takes the clarity and air up a few notches and reduces the distortion.  I remember seeing some measurements on the Bottlehead forum of various power tubes in the stock Crack, the 5998 had significantly less distortion than the stock 6080.  So, the changes you hear when going from the 6080 to the 5998 might be indicative of what you might hear more of when you add the SB, a good litmus test perhaps.

THD of various output tubes: http://i.imgur.com/FWphjsJ.png

Parent post: https://bottlehead.com/smf/index.php?topic=7853.0


----------



## L0rdGwyn (May 9, 2019)

Running the British Invasion tube setup in the Crackatwoa this morning, Brimar CV1988 input, MOV A1834 output, some Telefunken EL90 shunt reg tubes, jamming on the HD600 and Atticus 




Since I got my hands on a MOV A1834, I think I have finally collected the Pantheon of 6AS7G-type output tubes for the Crack(atwoa), here is the final lineup:

Tier I:
MOV A1834
Tung Sol 7802
Western Electric 421A

Tier II:
Tung Sol 421A
Tung Sol 5998
Tung Sol/Chatham 6AS7G

Tier III:
Bendix 6080WB solid graphite plates
Mullard CV2984
Tung Sol 6080

I have a few others but these are the top for me.  Happy to give comparisons if anyone is considering any of these tubes.

Edit: reorganized output tubes by tier


----------



## Wes S (May 9, 2019)

L0rdGwyn said:


> Running the British Invasion tube setup in the Crackatwoa this morning, Brimar CV1988 input, MOV A1834 output, some Telefunken EL90 shunt reg tubes, jamming on the HD600 and Atticus
> 
> 
> 
> ...


Man!  I missed out on a heck of a deal on a MOV A1834!  However, I scored a pair of Tung Sol 5998, instead.   I absolutely love the U.K. sound, and Brimar are my favorite! I am on the hunt for the top 3 on your list.  How do the top 2 compare, to the 5998?  I have the Mullard ecc82 long plate square getter 57' Blackburn, and Brimar CV4003 (from Upscale Audio), and think that the top 2 on your list, might be to warm, for my driver tubes.  Thoughts?

I have that same CV1988, in my Lyr 3, and it is glorious!


----------



## L0rdGwyn (May 9, 2019)

Wes S said:


> Man!  I missed out on a heck of a deal on a MOV A1834!  However, I scored a pair of Tung Sol 5998, instead.   I absolutely love the U.K. sound, and Brimar are my favorite! I am on the hunt for the top 3 on your list.  How do the top 2 compare, to the 5998?  I have the Mullard ecc82 long plate square getter 57' Blackburn, and Brimar CV4003 (from Upscale Audio), and think that the top 2 on your list, might be to warm, for my driver tubes.  Thoughts?
> 
> I have that same CV1988, in my Lyr 3, and it is glorious!



Oh that's too bad!  I haven't had the A1834 long, but early impressions are very, very good, it's a well-balanced tube.  The 5998 is great though.

So re-reading my post, I realized it sounded like I had ranked the tubes, but they were actually alphabetical ha!  So I went and reorganized them into tiers in terms of how I think they perform.  The top three for me are the MOV A1834, the Tung Sol 7802, and Western Electric 421A.  I know there is some debate as to whether the 421A is just a rebranded 5998 or not, but I have had a few 421A's and several 5998's, and IMO, the 421A is slightly better, a little better air/staging and slightly better detail, but the 5998 will get you like 90% of the way there.  Unless you are crazy like me and want to collect them all and get max performance, I wouldn't suggest getting a 421A over a 5998.  They are also very, very similar in terms of presentation.

The Tung Sol 7802 is a very interesting albeit quite rare tube.  It very well could have the largest soundstage and be the most detailed out of the bunch.  BUT it is also one of the brightest and most dynamic, I would say just bright of neutral, gives the upper midrange some more bite and it is a more mid-range forward tube compared to the 5998, which some might already consider to be a little bit bright and forward.  It has a pretty aggressive sound, which is nice with more laid-back headphones.

As far as the 6080's go (Bendix, Mullard, Tung Sol), in my experience, you lose a significant amount of soundstage and separation with these tubes.  They all have a similar head-stage, but differ in tonality.  I probably prefer the Tung Sol of the three, I think it has the best low-end, but honestly I use them very infrequently, since soundstage/dynamics/detail are important to me and the tubes higher on the list offer more in that department.  I think I paid $30 for my Mullard CV2984 two years ago, now they are going for $100 or more and at that price I don't think they are worth it, same for the Bendix.

So far, the MOV A1834 is interesting to me in that it doesn't seem to assert as much of a specific tonality/timbre, it sort of gets out of the way and allows the driver tube to have more influence on the sound.  Still very detailed and good soundstage, maybe a little less enveloping than the 421A and 7802 and less aggressive, but overall it's just very well-balanced and natural sounding.  It is probably the most "neutral" of my top three.

This has probably been said before, but as far as output tubes go, my advice for getting to 90% of max performance (in terms of soundstage/air/detail) would be to go for the 5998 and stop.  To me, it is better than any 6080.  If you want to get into the top 90-100% of performance, then you'd have to shell out $200+ for a 421A or wait forever to find a 7802.  I think the 5998 vs. the A1834 could really come down to personal preference, and the A1834 will also cost $200+.

As far as driver tubes go, I have tried several 12AU7 variants, but never the Mullard long-plate.  Some of the best 12AU7 drivers I have are Mullard CV4003, Telefunken CV491 long-plate, Siemens ECC82 nickel plate, Pinnacle 13D5, and Brimar CV4034.  The best I have heard is the Brimar CV4034, which is a flying-lead type tube and needs to be soldered to an adapter, probably pretty hard to come by these days.  But once I went down the 6SN7 rabbit hole, starting with the Sylvania 6SN7W short bottle, I never looked back, 6SN7's are my preference for drivers in the Crack(atwoa).

Sorry for the text wall!  Just figured I'd get it all out there  also, I would assume these impressions would mostly hold true for the non-Speedball Crack, but I can't say for sure.


----------



## Wes S (May 9, 2019)

L0rdGwyn said:


> Oh that's too bad!  I haven't had the A1834 long, but early impressions are very, very good, it's a well-balanced tube.  The 5998 is great though.
> 
> So re-reading my post, I realized it sounded like I had ranked the tubes, but they were actually alphabetical ha!  So I went and reorganized them into tiers in terms of how I think they perform.  The top three for me are the MOV A1834, the Tung Sol 7802, and Western Electric 421A.  I know there is some debate as to whether the 421A is just a rebranded 5998 or not, but I have had a few 421A's and several 5998's, and IMO, the 421A is slightly better, a little better air/staging and slightly better detail, but the 5998 will get you like 90% of the way there.  Unless you are crazy like me and want to collect them all and get max performance, I wouldn't suggest getting a 421A over a 5998.  They are also very, very similar in terms of presentation.
> 
> ...


Thanks for all the great info!  I am glad I scored those 5998's, and will stick with that for a while, and then look for an A1834 or 421a, later down the road.  I have all the great 6SN7's, but wanted to have a different tube, for switching things up, so I am sticking with the 12AU7's, in the Crack.  The next driver tube, I am on the hunt for is, the Brimar 13D5.


----------



## attmci (May 9, 2019)

deleted.


----------



## L0rdGwyn

attmci said:


> TBH, you guys can put those tubes to good use if you upgrade to another amp.



Quite the patronizing remark!  I will dignify it only by saying, no thank you, I am very content with what I have built myself and its performance.


----------



## L0rdGwyn

Wes S said:


> Thanks for all the great info!  I am glad I scored those 5998's, and will stick with that for a while, and then look for an A1834 or 421a, later down the road.  I have all the great 6SN7's, but wanted to have a different tube, for switching things up, so I am sticking with the 12AU7's, in the Crack.  The next driver tube, I am on the hunt for is, the Brimar 13D5.



You're welcome!  Sounds like a great approach.  I have heard/read great things about the Brimar 13D5, I suspect it will be the next performance bargain the tube-loving community will make a run for.  Better get em while they're still cheap


----------



## attmci

L0rdGwyn said:


> Quite the patronizing remark!  I will dignify it only by saying, no thank you, I am very content with what I have built myself and its performance.


NP. 

I went through the same path a couple years ago. I still have the Crack I built and upgraded.


----------



## Wes S (May 10, 2019)

L0rdGwyn said:


> Quite the patronizing remark!  I will dignify it only by saying, no thank you, I am very content with what I have built myself and its performance.


I seen that comment, all the time and always, disregard it.  I love putting the best tube I can find, in my tube amps, regardless how much the amp cost.  Seems like a good and easy way, to get better performance.


----------



## cobyatch (May 10, 2019)

Hey everyone, thought I'd share my tube rolling experiences with you all. Running them all with a Tung Sol 5998, speedball upgrade, and a cheap stepped attenuator from eBay. Shoutout to L0rdGwyn for helping me start my journey haha 

*Sylvania 6F8G*: Very energetic and fun tube. Bass is thick and has a lot of upper mid/treble presence. Largest soundstage of the bunch. My favorite with the Atticus when I want powerful, in-your-face bass.

*National Union 6F8G*: Clean and fast sounding tube, probably the closest to neutral and analytical out of the ones I've tried. Soundstage more intimate than the Sylvania. Slight touch of warmth while retaining speed and clarity. Upper bass can get a bit muddy with the Atticus, but works great with the HD6XX IMO. Compliments the HD800 perfectly, giving it the right amount of warmth and retains detail.

*Pinnacle 13D5A*: Really nice tube. A bit more bass presence than the NU with smoother vocals. Soundstage pretty much on par. A lot more clarity in the mids and highs compared to the stock 12AU7 tube, however doesn't extend as much in the highs compared to the 6F8G tubes. My personal favorite with the HD800 for a more romantic listening experience. Really surprised by this pickup considering how cheap they were on eBay, highly recommend picking up.

Looking into getting more tubes soon, have my eyes on the RCA 6F8G but would love your guy's recommendations as well. Also, is upgrading the output caps worth it? Seems like it's a pretty common upgrade but haven't read much about the benefits of it.


----------



## Wes S

cobyatch said:


> Hey everyone, thought I'd share my tube rolling experiences with you all. Running them all with a Tung Sol 5998, speedball upgrade, and a cheap stepped attenuator from eBay. Shoutout to L0rdGwyn for helping me start my journey haha
> 
> *Sylvania 6F8G*: Very energetic and fun tube. Bass is thick and has a lot of upper mid/treble presence. Largest soundstage of the bunch. My favorite with the Atticus when I want powerful, in-your-face bass.
> 
> ...


Good stuff!  I found some of those 13d5a and 13d5, on ebay and I am gonna get one of them, soon.


----------



## attmci

L0rdGwyn said:


> Quite the patronizing remark!  I will dignify it only by saying, no thank you, I am very content with what I have built myself and its performance.


Congratulation on the new GOTL!!


----------



## attmci

Wes S said:


> I seen that comment, all the time and always, disregard it.  I love putting the best tube I can find, in my tube amps, regardless how much the amp cost.  Seems like a good and easy way, to get better performance.


Great idea!


----------



## L0rdGwyn (May 19, 2019)

attmci said:


> Congratulation on the new GOTL!!



What can I say?  What I said was true, I love my Crackatwoa.  After realizing I had matched pairs of 421As and 7802s, curiosity gave way.  I plan to keep my Crackatwoa, it is a great amp, as is the Crack, we will see how they compare 

Oh, and don't congratulate me yet, the long wait now begins...


----------



## attmci (May 20, 2019)

L0rdGwyn said:


> What can I say?  What I said was true, I love my Crackatwoa.  After realizing I had matched pairs of 421As and 7802s, curiosity gave way.  I plan to keep my Crackatwoa, it is a great amp, as is the Crack, we will see how they compare
> 
> Oh, and don't congratulate me yet, the long wait now begins...


You sure you don't want to roll the rectifier tubes? You don't need the most expensive ones to roll. And a rectifier tube will last very long.

You can Google and find out how rectifier tubes can change the sound.

Best wishes.


----------



## adydula (May 23, 2019)

I have been spending ALOT of time with Burson Audios FUN amp and its various SS discrete op amps.

I put it away for awhile and started listening with the Crack with Speedball....RCA NOS 6AS7G and RCA 12AU7 Clear Top.

For two days I have ben listening and fallen in love with its sound all over again.

Words like, smooth, lucid, warm, lush, musical, to die for sound come out of my head....all with a set of HD600's.

Low levels, mid vol levels etc all sound so nice.

This amp and these cans make for such a nice listenable musical experience I am torn with leaving it again for more testing and evaluation!!

Next is the Mainline....but this BH Crack is indeed very, very special!!

Alex


----------



## adydula

I switched over to my Bottlehead Mainline this morning...and after an hour or so I have finally deduced that the Senn 600's sound better overall to me with the Crack!!

With my Beyer T1's the Mainline is the amp for them...

I think the Mainline being more articulate and light saber resolution qualities helps with IMO the more laid back sound of the T1's.
With the 600's and the Mainline its like they are too accurate or bright sounding...

Put the T1's on the Crack and its too subdued overall....put the Senns on the Crack and voila! Its audio nirana.

Alex


----------



## ALL212

New variation of the Crack with modifications. I've created an album of more pictures called the Crack C-4 version ( https://www.head-fi.org/gallery/album/crack-c-4-version.1154954/ ).  C-4 as this is my 4th Crack build.  I also have a Mainline, Crack-a-2-a and S.E.X. headphone amps.

I'm running Senn HD650, HD800s and ZMF Auteurs on it.  The only major circuit change was using a much larger final power supply cap (470uf) and then dropping the output cap total to 79uf.  I also plumbed the pre tube for a 6SN7 instead of the 12AU7.  So far the sound is wonderful - bass is plentiful (especially with the ZMF's).


----------



## JamieMcC

I always thought that the T1 sounded a bit thin out of a stock Crack but on a Crack with all the normal mods it was significantly better almost like listening to a different headphone it scaled so well.

I used T1 on the Mainline for a while but after trying the hd800 Mainline combo there was no going back.


----------



## L0rdGwyn

ALL212 said:


> New variation of the Crack with modifications. I've created an album of more pictures called the Crack C-4 version ( https://www.head-fi.org/gallery/album/crack-c-4-version.1154954/ ).  C-4 as this is my 4th Crack build.  I also have a Mainline, Crack-a-2-a and S.E.X. headphone amps.
> 
> I'm running Senn HD650, HD800s and ZMF Auteurs on it.  The only major circuit change was using a much larger final power supply cap (470uf) and then dropping the output cap total to 79uf.  I also plumbed the pre tube for a 6SN7 instead of the 12AU7.  So far the sound is wonderful - bass is plentiful (especially with the ZMF's).



Looks awesome, love the "6080" and "6SN7" cut outs in the top plate.


----------



## Wes S

Happy to join the club!  I fired up my Crack Speedball, for the first time last night, and within minutes, my HD650 never sounded so freakin good!  I am pairing up the Crack and my Aeolus tonight, and think I am in for some musical bliss!

Happy Friday!


----------



## Wes S (Jun 14, 2019)

Just did my first roll with the Crack Speedball, and decided not to mess around and went with my A- Team.  I was going to work my way through my stash from medium grade tubes, then onto my top tier tubes, but made a last minute descision, and said what the heck, let's see what this amp can really do.  I rolled in the Tung Sol 5998 and Mullard ECC82 57' Blackburn Square Getter.  Damn, I did not know my HD650's could produce bass like this!  I am going to make sure all is well tonight, and then tomorrow the Aeolus, gets it turn.  I will report back, after some burn in.


----------



## Spareribs

Their products are so cool looking, One of these days I’m going to build one of their phono preamps


----------



## Wes S

Well after some tube rolling, I have realized the 5998 and Mullard ECC82 Long Plate, were a bit to warm, and bloated, for my Aeolus.  So, now I am jamming with the 5998 and Brimar CV4003, and they are perfect.  I did roll a Bendix 6080wb slotted plate, with the Mullard ECC82 Long Plate and that sounded really freakin good, however the Bendix was a bit noisy, and is being returned.

If anyone has a spare Bendix 6080wb slotted plate, I would love to buy it.


----------



## Astral Abyss

Wes S said:


> If anyone has a spare Bendix 6080wb slotted plate, I would love to buy it.



Wouldn't we all...


----------



## isitaheadset (Jun 18, 2019)

I know this gets asked a lot of times, but for the people who built it, is it too difficult for someone that had pretty much 0 experience with electronics? How long does it take to assemble it?

Edit: oh my god, someone revived this really old post and I commented here too, sorry mods :S


----------



## L0rdGwyn

isitaheadset said:


> I know this gets asked a lot of times, but for the people who built it, is it too difficult for someone that had pretty much 0 experience with electronics? How long does it take to assemble it?
> 
> Edit: oh my god, someone revived this really old post and I commented here too, sorry mods :S



As long as you have the necessary tools and follow the directions carefully, anyone can do it.  I would not recommend it  someone who is impatient though, as it is possible to make a mistake and can be frustrating to go back and fix it.  I would say it can be done in three sessions for the circuit, plus another for finishing the wood base and top plate.  Maybe four evenings during a single week.  Keep in mind you want to do the finishing of the base and top plate before assembling the circuit.  You can always leave them as is though if you don't care about aesthetics.

*Need to haves:*
Soldering iron
Solder
Multimeter
Soldering wick or solder sucker (for solder removal)
Wood glue
Tape
Wire strippers

*Nice to haves:*
Wood finishing supplies (stain, top coat, foam brush, sand paper)
Top plate finishing supplies (spray paint is the most common method)
Bent nose pliers (these will make the whole process 100x easier, I like these ones: https://xuron.com/index.php/main/consumer_products/5/34)

The nice thing about building yourself is you can reuse these tools for other projects.  For example, you have just about everything you would need to build your own headphones cables, besides the raw materials of course.


----------



## isitaheadset

L0rdGwyn said:


> As long as you have the necessary tools and follow the directions carefully, anyone can do it.  I would not recommend it  someone who is impatient though, as it is possible to make a mistake and can be frustrating to go back and fix it.  I would say it can be done in three sessions for the circuit, plus another for finishing the wood base and top plate.  Maybe four evenings during a single week.  Keep in mind you want to do the finishing of the base and top plate before assembling the circuit.  You can always leave them as is though if you don't care about aesthetics.
> 
> *Need to haves:*
> Soldering iron
> ...


Thank you so much for these detailed instructions!! I’ll buy one very soon and I appreciate that you took your time to write this. I’ll give this a go since I’m studying Electrical engineering at college, so most of these tools I’ll end up buying either way.


----------



## Spareribs (Jun 19, 2019)

For people who have no experience with a soldering iron, it’s not a bad idea to practice with a small cheap circuit board kit that’s designed for students. You probably can find them at Amazon.com. Even if you mess up those little student kits, it does not predict you can’t build a tube amp.

My first practice soldering circuit kits and circuit board projects were disasters but I did successfully  build a guitar tube amp anyway and it worked fine.


----------



## TylersEclectic

YouTube is your friend! also don’t heat the solder, but the joint =) the crack was my first foray into soldering and it was pretty easy....that being said I would do it again and I’m positive it would look nicer as I learned a lot during the process.


----------



## L0rdGwyn

isitaheadset said:


> Thank you so much for these detailed instructions!! I’ll buy one very soon and I appreciate that you took your time to write this. I’ll give this a go since I’m studying Electrical engineering at college, so most of these tools I’ll end up buying either way.



No problem, happy to answer any questions you may have.  I have built the Crack + Speedball and the Crackatwoa, both great amps.


----------



## isitaheadset

Thank you everyone for the replies. I'll be getting some practice kits for sure!


----------



## Tom-s (Jun 19, 2019)

I'm a Bottlehead addict and the next kit is on it's way.
In 2013 i've build my first Crack kit. When i got, i first had to go to the local hardware store and buy a soldering station and learn how to solder.
Since then, i've build various BH amps and DIY amps. Crack was my gateway drug.
I'm also a student but have no electronic or engineering background as you do, you'll be fine.



			
				Something i've written on this forum before. It  said:
			
		

> *A word on what makes these kits so special to me.:*
> 
> What, for me, makes these kits stand apart from any other piece of audio equipement i own or have owned is not the sound quality. Good sound quality can be bought (usually at a far higher price). These kits can teach you, how your equipement works, what influences the sound and in the end, how to do it yourself. This is the essence of these kits. You can learn a thing or two from the experience. They can be anyones gateway drug into building your own high-end audio equipement. What these amps can teach you about audio electronics is often overlooked on "hi-fi forums" and is what i’m most grateful for.
> 
> ...


----------



## Tom-s

A few month ago this video was posted on Vimeo. It tells all about the Bottlehead company. 
Beyond that, it shows the whole process of building a kit. 
A must watch imho! 
Oh and here's one on Blumenstein Audio!


----------



## LikeABell

Tom-s said:


> A few month ago this video was posted on Vimeo. It tells all about the Bottlehead company.
> Beyond that, it shows the whole process of building a kit.
> A must watch imho!
> Oh and here's one on Blumenstein Audio!



This is so good, thanks for sharing!


----------



## L0rdGwyn

Tom-s said:


> A few month ago this video was posted on Vimeo. It tells all about the Bottlehead company.
> Beyond that, it shows the whole process of building a kit.
> A must watch imho!
> Oh and here's one on Blumenstein Audio!




Really cool video!  Thanks for posting.


----------



## Wes S

Astral Abyss said:


> Wouldn't we all...


And I found one!  From a forum member


----------



## Wes S

Tom-s said:


> A few month ago this video was posted on Vimeo. It tells all about the Bottlehead company.
> Beyond that, it shows the whole process of building a kit.
> A must watch imho!
> Oh and here's one on Blumenstein Audio!



Thanks for posting this!  I really enjoyed, both videos.


----------



## Wes S (Jun 23, 2019)

On another note, I finally have my BHC Speedball and tubes (Mullard ECC82, Long Plate 57' Blackburn & Tung Sol 5998), all burned in, and the sound is amazing.  The sound is wide and deep, with warmth, yet plenty of detail.  Natural and real, are two words that come to mind.  This amp and tube combo, is stunningly magical, with my ZMF Aeolus!

ZMF Aeolus + Schiit Gungnir Multibit + BHC/Speedball = ENDGAME


----------



## TylersEclectic

Wes S said:


> On another note, I finally have my BHC Speedball and tubes (Mullard ECC82, Long Plate 57' Blackburn & Tung Sol 5998), all burned in, and the sound is amazing.  The sound is wide and deep, with warmth, yet plenty of detail.  Natural and real, are two words that come to mind.  This amp and tube combo, is stunningly magical, with my ZMF Aeolus!
> 
> ZMF Aeolus + Schiit Gungnir Multibit + BHC/Speedball = ENDGAME


 I really do need to finish my speedball upgrade....it is just sitting on my work bench lol


----------



## LikeABell

Darthpool said:


> I really do need to finish my speedball upgrade....it is just sitting on my work bench lol


If you can, I'd suggest listening to a SB upgraded Crack before putting your Crack under the knife.
I sometimes miss the euphonic sound of the stock Crack.


----------



## Wes S

LikeABell said:


> If you can, I'd suggest listening to a SB upgraded Crack before putting your Crack under the knife.
> I sometimes miss the euphonic sound of the stock Crack.


Interesting.  I have euphonics in spades, with my Liquid Platinum, so I have that covered.  However, I would like to hear a non speedball, just for kicks.


----------



## TylersEclectic

LikeABell said:


> If you can, I'd suggest listening to a SB upgraded Crack before putting your Crack under the knife.
> I sometimes miss the euphonic sound of the stock Crack.


This is part of the reason I haven't upgraded it yet lol...maybe I need to buy another kit ...hmmm


----------



## Wes S (Jun 24, 2019)

Darthpool said:


> This is part of the reason I haven't upgraded it yet lol...maybe I need to buy another kit ...hmmm


I actually did some research on this, before going with the speedball, and it seems about 95% of the people, preferred the Speedball upgrade.  However, there are some that have stayed with the original, and are very happy.  The big thing, that caught my attention, was that the Speedball upgrade is said to take down the noise to nothing, which really adds to the experience.  My BHC speedball, is dead silent, with a black background, and I love it.  With the only other OTL I have owned, the Valhalla 2, I always had a bit of hum in the background, and it drove me nuts.


----------



## L0rdGwyn

I had the original kit for a few days, but I really enjoyed building, so I added the Speedball almost right away.  I do remember having a "WOAH! That sounds different" reaction to the original circuit.  Definitely a more "tubey" distorted sound.  The Speedball lowers distortion significantly, gives the Crack more clarity and improves technical performance.  I have thought about building another stock Crack to give that tubey-ness another try  curious how the original circuit would sound with TOTL tubes, which I did not own at the time.


----------



## donato

Yeah, I bought another kit just so I could build without speedball first to compare with and w/o speedball for awhile.  Then I'd eventually upgrade it to speedball and start modding it.


----------



## Paladin79 (Jun 24, 2019)

I did the same, and kept a stock Crack as a baseline while I modded the second Crack. I did a lot of A/B testing before I achieved the sound I wanted, then I started experimenting with tubes and 6sn7 variations. My favorite is twin 7A4 VT 192 tubes.


----------



## New Yorker

isitaheadset said:


> I know this gets asked a lot of times, but for the people who built it, is it too difficult for someone that had pretty much 0 experience with electronics? How long does it take to assemble it?


I elected to have mine assembled. And yes, it added to the cost significantly. It’s not that I thought I couldn’t build it myself; I’m VERY patient and quite good at following well-written instructions. (No one can assemble IKEA furniture as well as I can, lol.) No, the problem was that I’ve never soldered before, and I own none of the necessary tools. Worse, I believe doing nice woodworking (I’ve never done any) requires some experience. So while I had no doubt that I could build a Bottlehead Crack that would probably work, I feared that it would LOOK like someone’s first ever electronic kit project. And I wanted mine to look factory perfect. Awaiting delivery now!


----------



## Wes S (Jun 25, 2019)

New Yorker said:


> I elected to have mine assembled. And yes, it added to the cost significantly. It’s not that I thought I couldn’t build it myself; I’m VERY patient and quite good at following well-written instructions. (No one can assemble IKEA furniture as well as I can, lol.) No, the problem was that I’ve never soldered before, and I own none of the necessary tools. Worse, I believe doing nice woodworking (I’ve never done any) requires some experience. So while I had no doubt that I could build a Bottlehead Crack that would probably work, I feared that it would LOOK like someone’s first ever electronic kit project. And I wanted mine to look factory perfect. Awaiting delivery now!


It is an amazing amp, either if you built it or had it built.  No shame, as I paid a pro, and could not be happier.




I tend to worry about the smallest things, and just wanted to enjoy the amp, without thinking about cold solder joints, and whether I was getting peak performance.  Now, that I have a perfect BHC, I would like to build one myself down the road, as I have benchmark to follow, and compare.

The amp has speedball added and an Alps Blue Velvet pot, and is top notch.


----------



## New Yorker

Wow, that’s beautiful!


----------



## L0rdGwyn

Wes S said:


> It is an amazing amp, either if you built it or had it built.  No shame, as I paid a pro, and could not be happier.
> 
> 
> 
> ...



I've seen that builder's work on Etsy/eBay, top quality looks great!


----------



## Wes S (Jun 25, 2019)

L0rdGwyn said:


> I've seen that builder's work on Etsy/eBay, top quality looks great!


Yep!  Etsy, is where I got it, and the work is top notch, and worth the cost.  This amp started as a kit, and is now heirloom quality.


----------



## L0rdGwyn

Wes S said:


> Yep!  Etsy, is where I got it, and the work is top notch, and worth the cost.



It really is, I've always wondered how they got the wire angles so precise, very clean.


----------



## SilverEars

Anybody know who designed Crack?


----------



## TylersEclectic

Recently got the 6SN7 adapter and Tung Sol 6SN7GTB tube… I think I like it a lot…now to find a cover for the adapter lol

It is dead silent with no music except at Max volume... already sounds great with no break in. Very excited for this


----------



## cebuboy

Been wondering to ask, can the stock power supply handle the extra current needed to run the 6SN7?


----------



## Paladin79 (Jun 29, 2019)

I certainly hope so, I have been running one for a couple years now, as has my son, and one employee and a few friends. 

When I say running one, I mean one variation of the 6sn7 or another. I have run dual 6J5’s and 7A4’s single triode versions that each require half the filament current of a 6SN7.  I have run 7N7’s, the loktal version of the 6SN7 as well.

I run the same tubes in a Schiit Vali 2 that normally draws about 450 milliamperes of filament current but can handle the higher current for the 6SN7.

My favorite single tube is the 6N8S 1578 Melz (6sn7 equivalent), you have to be very careful which version you buy and they can be pricey because they are highly sought after. They sound very different than your normal RCA, Sylvania or Tung Sol so they may not be for everyone.


----------



## TylersEclectic

Paladin79 said:


> I certainly hope so, I have been running one for a couple years now, as has my son, and one employee and a few friends.
> 
> When I say running one, I mean one variation of the 6sn7 or another. I have run dual 6J5’s and 7A4’s single triode versions that each require half the filament current of a 6SN7.  I have run 7N7’s, the loktal version of the 6SN7 as well.
> 
> ...



I have always liked your custom builds and the look of them! I especially like the VU meters!


----------



## Paladin79

Darthpool said:


> I have always liked your custom builds and the look of them! I especially like the VU meters!



Thanks for your kind words.  Here is a Crack with one of the 6sn7's. I will be testing around 20 of them as part of a challenge I am involved with. I have help though.


----------



## Tom-s

cebuboy said:


> Been wondering to ask, can the stock power supply handle the extra current needed to run the 6SN7?



Crack's heater winding on the PS is designed for 3.5A total current. It's designed with all the needed headroom to accommodate tube rollers abuse. The 6080/6AS7 uses 2.5A (or 2.4A for 5998, 7236). This leaves +-1 amp for the driver tube.

On a hot day, even with higher current "6SN7 equivalents" like ECC32 (0.9A) and a Bendix 6080WB for the output, Crack takes this abuse perfectly.

So a normal 6SN7 (0.6A) won't be a problem.



SilverEars said:


> Anybody know who designed Crack?



How i remember it, is that Crack was based on an older OTL schematic. Reworked by the guys at BH for optimal headphone performance.
It's probably been a team effort, where based on the original design different drivers, and bias options passed through selection before settling on the 12au7 direct coupled, led bias setup OTL. Maybe this is a good question to ask on the BH forum. 



Paladin79 said:


> I will be testing around 20 of them as part of a challenge I am involved with. I have help though.



You've got my attention, do tell us more about that challenge!


----------



## Paladin79 (Jun 29, 2019)

Ok the challenge. Sealed within this PVC pipe is a 6SN7 tube, only the pins stick out. Top, and all sides are well sealed and the pipe is vented. A friend in North Carolina has bet me a steak dinner with a big bottle of wine (he hates GE tubes), that he will pick a GE at the very bottom of whatever tubes I send him, (all 6sn7 equivalents).  Each tube is numbered  1-8 but after he does the listening and I tell him what the tubes really are, we can change the numbers, send them on to other friends and they can try to figure out which tube is which. No bets involved with them. I own in excess of 200 6sn7 tubes and will do a lot of listening to make it as hard as possible but I will send him tubes with similar emission so they sound at or near their peak. Tubes may well include RCA, Sylvania, Ken-Rad, Melz, Foton, Marconi, Hytron, Mullard, etc. I will make every effort to insure a tube was not built by another company and re-branded. I have CBS tubes like that, some are obviously GE, others are made by Sylvania I believe. No tubes will be harmed and when all is done I can recover them. I am including many of the tubes my friend knows and loves, 1953 Foton with ribbed plates, tall body 7n7's (a loktal equivalent of a 6sn7), Melz 1578 etc.

If anyone wishes to try this themselves down the road, PM me and I will see about sending the tubes your way. If nothing else, it may be a chance for you to hear some black glass and grey glass tubes from the 40's compared to some more modern tubes.

I should note I am testing this in a $100 headphone amp, just in case the wax melts I am not about to take a chance with another amp lol, no offence to Schiit.


----------



## SilverEars

Tom-s said:


> How i remember it, is that Crack was based on an older OTL schematic. Reworked by the guys at BH for optimal headphone performance.
> It's probably been a team effort, where based on the original design different drivers, and bias options passed through selection before settling on the 12au7 direct coupled, led bias setup OTL. Maybe this is a good question to ask on the BH forum.


I'm curious because I'm wondering what else has the designer of Crack and the speedball has also designed?


----------



## JamieMcC

I had always thought the Cracks conception was  down to Paul Birkelands (PB / Caucasian Blackplate)  I think he  also does/did some custom design work as well  as there are a few posts about online.


----------



## SilverEars

Wes S said:


> It is an amazing amp, either if you built it or had it built.  No shame, as I paid a pro, and could not be happier.
> The amp has speedball added and an Alps Blue Velvet pot, and is top notch.


That looks well built.  Whoever built that seems to be very detailed oriented. 

A good build is important with this amps because the solder-joints must be soldered with good amount of solder.  Building one of these I realized how important well soldered joints are for proper sound out of these amps.


----------



## attmci (Jun 30, 2019)

Tom-s said:


> Crack's heater winding on the PS is designed for 3.5A total current. It's designed with all the needed headroom to accommodate tube rollers abuse. The 6080/6AS7 uses 2.5A (or 2.4A for 5998, 7236). This leaves +-1 amp for the driver tube.
> 
> On a hot day, even with higher current "6SN7 equivalents" like ECC32 (0.9A) and a Bendix 6080WB for the output, Crack takes this abuse perfectly.
> 
> ...


You' better not using the 6SN7GT with  a pair of 6bl7/6bx7.

The 6bl7/bx7 are the most suitable power tubes for a Crack. Don't know why they are not using these.

I highly recommend the other Tom to make a Crack to use these tubes. We may have to move the power tube socket away from the transformer.




*Paladin79*


----------



## audiowize

attmci said:


> You' better not using the 6SN7GT with  a pair of 6bl7/6bx7.
> 
> The 6bl7/bx7 are the most suitable power tubes for a Crack. Don't know why they are not using these.
> 
> ...


We will be looking forward to the release of your 6BX7 OTL amp! 

You will find that a 6BX7 is about twice the price of a 6080 and far less common.  The heater cathode insulation on a 6BX7 is also inferior to a 6080, so be careful where you use them!  There are also a great many negative reviews of paralleling triodes.  How do you ensure that one half of the 6BX7 isn't drawing 90% of the current and the other half 10%?  Under these conditions you lose the assumed benefits of the paralleled triodes in the first place and you're better off with a single tube.  If you want to provide 6BX7s with matched triode sections, then you will take an expensive and somewhat uncommon tube, then throw a large number of them away because they have poorly balanced sections.  

An additional complication is that the higher mu of the 6BX7 will push the operating point of the 6BX7 in a Crack close to where it will draw grid current and seriously impede the performance of the amp.  This is improved a little bit by using a second tube, but at the same time (assuming each tube shares current equally) you will run into cutoff very quickly.  I think you'd swing less than 3.5V RMS before distortion got ridiculous into a 300 Ohm load, that's terrible!  Using a single 6080 that number is more like 17V RMS, but clearly that's not the right tube to use right?

While you might love the way this sounds and think that everybody's amp should sound like this, that viewpoint is poorly supported by empirical standards.  I have no doubt that it sounds a lot different than a 6080.


----------



## attmci

audiowize said:


> We will be looking forward to the release of your 6BX7 OTL amp!
> 
> You will find that a 6BX7 is about twice the price of a 6080 and far less common.  The heater cathode insulation on a 6BX7 is also inferior to a 6080, so be careful where you use them!  There are also a great many negative reviews of paralleling triodes.  How do you ensure that one half of the 6BX7 isn't drawing 90% of the current and the other half 10%?  Under these conditions you lose the assumed benefits of the paralleled triodes in the first place and you're better off with a single tube.  If you want to provide 6BX7s with matched triode sections, then you will take an expensive and somewhat uncommon tube, then throw a large number of them away because they have poorly balanced sections.
> 
> ...


https://www.head-fi.org/threads/2359glenn-studio.600110/


----------



## audiowize

attmci said:


> https://www.head-fi.org/threads/2359glenn-studio.600110/


You linked me to a thread with 1800 pages and didn't mention anything about why...


----------



## m17xr2b

attmci said:


> https://www.head-fi.org/threads/2359glenn-studio.600110/


Crack and Glenn have nothing in common, different input design, different output design, different PSU configuration and most likely different operating points.  
The crazy tube configs that can be used in the GennOTL cannot be used in the Crack


----------



## Paladin79 (Jul 1, 2019)

attmci said:


> You' better not using the 6SN7GT with  a pair of 6bl7/6bx7.
> 
> The 6bl7/bx7 are the most suitable power tubes for a Crack. Don't know why they are not using these.
> 
> ...



I will try to check out those tubes in the next couple days. I have experimented with the power tubes far less than the driver tube.

I do like to play it safe, I will go into my tube manuals and look at the specs for the 6BL7, there is also a good chance I own some of those tubes somewhere in my tube stash. I bought a whole bunch of power tubes to use in a headphone stand project and many of those tested fine (they were purchased as duds lol.)

I am always open to new ideas as long as they do no damage.


----------



## attmci

Paladin79 said:


> I will try to check out those tubes in the next couple days. I have experimented with the power tubes far less than the driver tube.
> 
> I do like to play it safe, I will go into my tube manuals and look at the specs for the 6BL7, there is also a good chance I own some of those tubes somewhere in my tube stash. I bought a whole bunch of power tubes to use in a headphone stand project and many of those tested fine (they were purchased as duds lol.)
> 
> I am always open to new ideas as long as they do no damage.


You need an adapter to use a pair of these. I had done a lot of research before used these on my Crack. They sounds great to me, but YMMV.


----------



## L0rdGwyn (Jul 2, 2019)

I never got around to giving 12BH7 drivers a shot in my Crack + SB or Crackatwoa.  That changes today...

Giving this Fivre 12BH7 a listen.  Man, this is a great tube!  Think it holds its own against the 6SN7 crew, sounds excellent with the Auteur, very detailed, articulate bass, great soundstage.  Love the Fivre label as well, glad I got one with it intact, $30 plus shipping for a pair


----------



## SilverEars (Jul 2, 2019)

I wonder what tubes combo is the most resolving and also clear with well textured mids?

Anybody notice how HD800's treble sounds different with different tube/amps?  Is there tube combination that makes 800(S) treble sound smooth yet detailed mids?

I'm totally fine with 600/650 with it, but 800(S) treble gets too sparkly at times, and it's rare to find anything the reduces it.  Also, I don't like how 800(S) are expressed as sparkly, and other setups more controlled in tightness.  I just don't like it when the treble sounds like sparkle, seemly unruley in control.

I also like it when sibilence harshness is subdue'd and sounds more like breathing vs chhhhhh


----------



## L0rdGwyn (Jul 2, 2019)

SilverEars said:


> I wonder what tubes combo is the most resolving and also clear with well textured mids?



Hard to say, as making those calls would vary from person to person.  What I will say though is the ladder of performance from the 6SN7 hierarchy holds true in the Crackatwoa.  The TOTL 6SN7s like the Tung Sol BGRP, Brimar CV1988, etc. are all very resolving and sound great in the Crackatwoa, but have different characteristics.  The ones I use most often are probably the Sylvania 6SN7W metal base, Fivre 6SN7GT black or grey plates, and RFT 6H8C/6SN7.  For output tubes, the same holds true, what are considered the best 6AS7 tubes actually do sound the best in the Crackatwoa.  My top three are the Western Electric 421A, MOV A1834, and Tung Sol 7802.  I also like the GEC 6080, Bendix 6080, and NEC 6AS7G.

From my experience, when you get some of these top tubes, resolution doesn't vary so much, it's really the character or perceived frequency response that does.  But many of these are very rare and expensive, you could buy another Crack + SB for the price of some of these tube combos.


----------



## SilverEars

L0rdGwyn said:


> Hard to say, as making those calls would vary from person to person.  What I will say though is the ladder of performance from the 6SN7 hierarchy holds true in the Crackatwoa.  The TOTL 6SN7s like the Tung Sol BGRP, Brimar CV1988, etc. are all very resolving and sound great in the Crackatwoa, but have different characteristics.  The ones I use most often are probably the Sylvania 6SN7W metal base, Fivre 6SN7GT black or grey plates, and RFT 6H8C/6SN7.  For output tubes, the same holds true, what are considered the best 6AS7 tubes actually do sound the best in the Crackatwoa.  My top three are the Western Electric 421A, MOV A1834, and Tung Sol 7802.  I also like the GEC 6080, Bendix 6080, NEC 6AS7G.
> 
> From my experience, when you get some of these top tubes, resolution doesn't vary so much, it's really the character or perceived frequency response that does.  But many of these are very rare and expensive, you could buy another Crack + SB for the price of some of these tube combos.


How similar and different is the Crackatowa from Crack?  Does it output more power and lowered impedance?


----------



## L0rdGwyn

SilverEars said:


> How similar and different is the Crackatowa from Crack?  Does it output more power and lowered impedance?



No, the output impedance is identical to the Crack + SB.  The main difference between the two amps is a larger power transformer and a more sophisticated power supply in the Crackatwoa.  It is shunt-regulated, which from my understanding means there will be greater isolation between the power supply and the output signal.  Mine also has the Bottlehead-developed TwoQuiet stepped attenuator.

Bottlehead describes the audible improvement in the Crackatwoa as a "blacker background" and more low end definition.


----------



## Wes S (Jul 3, 2019)

Bendix 6080wb > Tung Sol 5998

The Bendix 6080wb, and Mullard ECC82 57' Square getter long plate, just took the amp to another level!

The Bendix/Mullard combo, has the hardest hitting and most textured bass, I have heard.  The mids are insane and sounds are literally exploding from all directions, and the 3d like feel, is in full effect.  The sound is wide and deep, and each instrument has it's own space and I don't even feel like I am wearing headphones, but listening to speakers.  Very analoge like sound, and so punchy, you can feel every note.  The Bendix and Mullard, won't be coming out, any time soon.


----------



## Wes S

Happy Saturday!

Bendix 6080wb and Mullard ECC82 57' Long Plate is a killer combo!


----------



## L0rdGwyn

Happy Saturday to you as well, Wes!

The Tung Sol 421A and Fivre 6SN7GT black plate are also a killer combo  they synergize well with my morning coffee.


----------



## Paladin79

L0rdGwyn said:


> Happy Saturday to you as well, Wes!
> 
> The Tung Sol 421A and Fivre 6SN7GT black plate are also a killer combo  they synergize well with my morning coffee.



Fivre is not a brand I have used before, but I may have to check them out.


----------



## Wes S

L0rdGwyn said:


> Happy Saturday to you as well, Wes!
> 
> The Tung Sol 421A and Fivre 6SN7GT black plate are also a killer combo  they synergize well with my morning coffee.


Nice!  Those are some really nice and rare tubes you got there.  I will be trying all my "Holy Grail" 6SN7 tubes, one of these days.  However, for now I am loving the 12AU7.


----------



## Wes S

LOrdGwyn - I have never heard the Fivre, and I am curious what it's sound sig is like?  I have a bunch of Brimar, and love them, and I am curious how they compare.


----------



## L0rdGwyn

Paladin79 said:


> Fivre is not a brand I have used before, but I may have to check them out.



They are an Italian brand, really great stuff, worth a listen I think!  If they are intact, they can have beautiful labels too, here are some others in my collection.

 



Wes S said:


> Nice!  Those are some really nice and rare tubes you got there.  I will be trying all my "Holy Grail" 6SN7 tubes, one of these days.  However, for now I am loving the 12AU7.





Wes S said:


> LOrdGwyn - I have never heard the Fivre, and I am curious what it's sound sig is like?  I have a bunch of Brimar, and love them, and I am curious how they compare.



Thanks!  The Tung Sol 421A is a 5998 more or less, whether or not they are truly different is a hotly debated topic.

I would say if you like Brimar, Fivre is another good one to try.  Compared to the Brimar/STC CV1988, I would say the Fivre are a little bit less warm with a slightly more forward midrange, but it is infinitely smooth and what they are most known for.  Ever since a gracious Head-Fier gifted me a Fivre 6SN7 with a tube purchase I made, I have been smitten.  If you keep your eyes on international eBay, you can usually find a Fivre 6SN7 for $50 USD or less.


----------



## Wes S

L0rdGwyn said:


> They are an Italian brand, really great stuff, worth a listen I think!  If they are intact, they can have beautiful labels too, here are some others in my collection.
> 
> 
> 
> ...


Cool!  Thanks for the info.


----------



## cddc (Jul 20, 2019)

A question for you guys regarding differences in shipping fee on eBay:

I find some sellers charge only $3.5 for a 12AU7 tube using the basic Standard Shipping (USPS First Class Package®), while others can charge as much as $6.8 using the same Standard Shipping (USPS First Class Package®) for a similar 12AU7, almost doubled. Why is the difference? Is it the case that sellers set different shipping fees, or it's automatically set by eBay based on different shipping distances?


----------



## cddc

L0rdGwyn said:


> They are an Italian brand, really great stuff, worth a listen I think!  If they are intact, they can have beautiful labels too, here are some others in my collection.
> 
> 
> 
> ...




Nice tubes.


----------



## cddc

L0rdGwyn said:


> No, the output impedance is identical to the Crack + SB.  The main difference between the two amps is a larger power transformer and a more sophisticated power supply in the Crackatwoa.  It is shunt-regulated, which from my understanding means there will be greater isolation between the power supply and the output signal.  Mine also has the Bottlehead-developed TwoQuiet stepped attenuator.
> 
> Bottlehead describes the audible improvement in the Crackatwoa as a "blacker background" and more low end definition.



Cool stuff.

Can anyone explains the difference between shunt-regulated and choke? Will choke cause some loss on the output from power transformer, which leads to less power output from the power tube to headphones?


----------



## cddc

Paladin79 said:


> Ok the challenge. Sealed within this PVC pipe is a 6SN7 tube, only the pins stick out. Top, and all sides are well sealed and the pipe is vented. A friend in North Carolina has bet me a steak dinner with a big bottle of wine (he hates GE tubes), that he will pick a GE at the very bottom of whatever tubes I send him, (all 6sn7 equivalents).  Each tube is numbered  1-8 but after he does the listening and I tell him what the tubes really are, we can change the numbers, send them on to other friends and they can try to figure out which tube is which. No bets involved with them. I own in excess of 200 6sn7 tubes and will do a lot of listening to make it as hard as possible but I will send him tubes with similar emission so they sound at or near their peak. Tubes may well include RCA, Sylvania, Ken-Rad, Melz, Foton, Marconi, Hytron, Mullard, etc. I will make every effort to insure a tube was not built by another company and re-branded. I have CBS tubes like that, some are obviously GE, others are made by Sylvania I believe. No tubes will be harmed and when all is done I can recover them. I am including many of the tubes my friend knows and loves, 1953 Foton with ribbed plates, tall body 7n7's (a loktal equivalent of a 6sn7), Melz 1578 etc.
> 
> If anyone wishes to try this themselves down the road, PM me and I will see about sending the tubes your way. If nothing else, it may be a chance for you to hear some black glass and grey glass tubes from the 40's compared to some more modern tubes.
> 
> I should note I am testing this in a $100 headphone amp, just in case the wax melts I am not about to take a chance with another amp lol, no offence to Schiit.




LOL...thought the challenge was to cook something using 6SN7.


----------



## New Yorker (Jul 20, 2019)

Well, I received my assembled Crack/SB amp a couple of weeks ago and… I am lovin’ it. I didn’t know, at first, how to have it finished, exactly. Then it hit me; why not echo the look of my ancient Victor Victrola? And so that’s the way we went. I think it worked out well!


----------



## cddc

Can 12AT7 and 12AX7 be used in Crack? Anyone tried?

They have 6.3V 300mA heaters, same as 12AU7.

12AX7 is a high gain tube, 12AT7 and 12AU7 are both medium gain tubes.


----------



## audiowize

cddc said:


> Can 12AT7 and 12AX7 be used in Crack?
> 
> 
> 
> ...


----------



## cddc

Okay, but why?

They do not work in Crack, or sound bad?

From technical perspective they seem okay to me, same pinout and same heater current & voltage.


----------



## m17xr2b

From a technical perspective it's not even close to being OK. 
12AU7 needs -8.5 grid voltage, has 10.5mA of current, 7700ohm resistance, transconductance of 2200 and gain of 17.
12AT7 needs  -2    grid voltage, has 10mA of current,   11000ohm resistance, transconductance of 5500 and gain of 60
12AX7 needs -2    grid voltage, has  1.2mA of current,  4000ohm resistance, transconductance of 1600  and gain of 100.

These are not simple differences of +-10% but required fundamental circuit differences to operate properly. Some sound will be made but you will throw the operating point of the 6080 into the unknown. A crack it will no longer be.


----------



## audiowize

cddc said:


> Okay, but why?
> 
> They do not work in Crack, or sound bad?
> 
> From technical perspective they seem okay to me, same pinout and same heater current & voltage.



1.  Too much gain.  The 12AU7 is already pretty hot, but the 12AT7 and 12AX7 have significantly more gain that is absolutely not desired.
2.  Available B+ voltage.  The 12AU7 is perfectly fine with 80V on the plate, but a 12AX7 with 80V on the plate will either draw grid current or draw ridiculously low plate current.  In the stock Crack and the Crack with Speedball, the operating points are all wrong for the 12AX7.  The 12AT7 has similar issues.  The LED bias and the available plate voltage leave the tube near cutoff.
3.  The plate voltage of the 9 pin tube in the Crack biases up the 6080.  Too much plate voltage and the devices under the 6080 cathodes get really hot and you run out of plate to cathode voltage for the 6080 to work properly.  Too little voltage isn't as bad for the 6080, but you could run into compliance problems with the current sink loads in the Speedball.

If you wanted to use the 12AX7 or 12AT7 in a Crack style amp, you would want 300V of B+ and you would likely need to wrap feedback around the amp to make it usable (30-40dB of feedback for the 12AX7, 20-ish dB for the 12AT7) .  Otherwise when you rotate the volume control one degree, you will be very close to full output with most headphones and most sources (also known as a "hair trigger" volume control)

Notice that I didn't say anything about the heater voltage or current...


----------



## cddc

Ahh...I thought they are in the same family and have the same heater current&voltage, hence should work in the socket. Wild thought it is.

Thanks a lot for the correction!


----------



## audiowize

cddc said:


> Ahh...I thought they are in the same family and have the same heater current&voltage, hence should work in the socket. Wild thought it is.
> 
> Thanks a for the correction!


They are in the same family and they do have the same heater voltage, heater current, and pinout.  They are otherwise completely different devices and will need very different component values and operating points to work properly.


----------



## cddc

Tubes are just too complicated to me.

A higher gain 5998 can replace 6080, but we cannot do the same thing to driver tubes. 

I guess the key point is that the driver tube sets the operating points for power tube in Crack, so we cannot mess around with the driver tube.


----------



## Wes S (Jul 21, 2019)

New Yorker said:


> Well, I received my assembled Crack/SB amp a couple of weeks ago and… I am lovin’ it. I didn’t know, at first, how to have it finished, exactly. Then it hit me; why not echo the look of my ancient Victor Victrola? And so that’s the way we went. I think it worked out well!


Love everything about it!  Is that the stock wood base?  The grain on that looks awesome, and like some type of exoctic wood.


----------



## New Yorker (Jul 21, 2019)

Thanks! That base is
actually African mahogany, finished with red mahogany dye and denatured alcohol to color it a bit so that it resembles the red mahogany veneer on the Victrola. (It’s not a perfect “match”, nor was it meant to be; more of a subtle “tip o’ the hat” to the older machine.) The top plate is finished with a “gold vein” powder; its textured finish kinda, sorta resembles the texture on the wooden ornamentation around the top of the Victrola.

This masterful work was done by none other than Paul Birkeland of Bottlehead! He will assemble kits if you are unable to do it yourself. Yes, I could have built the thing, as I am patient and good at following well-written instructions. (I’m the king of perfectly assembled IKEA furniture; friends ask me to come over and build theirs, lol.) Alas, I live in a small NYC 1-bdrm apt with no garage, no basement and no ventilation. Worse, I’ve never soldered before. And to complete the Trifecta, I have zero woodworking experience. Suffice to say, I didn’t want to end up with a functional but sloppily assembled Bottlehead Crack that looked like someone’s first soldering job. And I definitely didn’t want the thing to look like the sorry bookshelf I made in tenth grade shop class. So having it built by someone who knows how to build electronics _and_ woodworking was pretty much a no-brainer.

I’m so glad you like it!


----------



## L0rdGwyn

New Yorker said:


> Well, I received my assembled Crack/SB amp a couple of weeks ago and… I am lovin’ it. I didn’t know, at first, how to have it finished, exactly. Then it hit me; why not echo the look of my ancient Victor Victrola? And so that’s the way we went. I think it worked out well!





New Yorker said:


> Thanks! That base is
> actually African mahogany, finished with red mahogany dye and denatured alcohol to color it a bit so that it resembles the red mahogany veneer on the Victrola. (It’s not a perfect “match”, nor was it meant to be; more of a subtle “tip o’ the hat” to the older machine.) The top plate is finished with a “gold vein” powder; its textured finish kinda, sorta resembles the texture on the wooden ornamentation around the top of the Victrola. So glad you like it!



That is SHARP.  Love it, nice attention to detail.  Enjoy the amp!


----------



## audiowize

cddc said:


> A higher gain 5998 can replace 6080, but we cannot do the same thing to driver tubes.


In the output stage, the output tube sees a certain amount of bias voltage at its grids (from the first stage), the B+ voltage, and the load under its cathodes.  When you use a 5998, the magnitude of the grid to cathode voltage drops a bit, but that change is inconsequential for proper amplifier operation.  The cathode follower also doesn't have any voltage gain, so the mu of the tube isn't a problematic parameter.


----------



## cddc (Jul 21, 2019)

@audiowize, thanks a lot for explaining the theory behind it.


----------



## cddc

L0rdGwyn said:


> That is SHARP.  Love it, nice attention to detail.  Enjoy the amp!



I second it. Great work from PB!


----------



## cddc

spacequeen7 said:


> http://www.ebay.com/itm/1pc-convert..._Audio_Amplifiers_Preamps&hash=item4ad0f9a77c



So have you tried any 6SL7 tubes on your Crack with this adapter, @spacequeen7 ?


----------



## audiowize

cddc said:


> So have you tried any 6SL7 tubes on your Crack with this adapter, @spacequeen7 ?


The 6SL7 is absolutely not at all acceptable for use in the Crack.  With the Speedball, the plate voltage on the 6SL7 will not drop much below the B+, so the 6080 will have absolutely no voltage to work with and the current sink under the 6080 cathodes would end up dissipating way too much heat if it did.  If any signal managed to squeeze its way out of the amp, it would be horrendously distorted.

With the stock circuit, the situation is only 99% as bad as the situation above. The amp would still be useless in this configuration.

The 6SL7 also has a very high amplification factor, and maybe one or two people in 13 years have asked for a Crack with more gain.  The 6SL7 is also the most microphonic indirectly heated tube I've ever used, which is another attribute nobody is looking for.

The 6SN7 will work just fine in a well made adapter though.


----------



## cddc (Jul 31, 2019)

audiowize said:


> The 6SL7 is absolutely not at all acceptable for use in the Crack.  With the Speedball, the plate voltage on the 6SL7 will not drop much below the B+, so the 6080 will have absolutely no voltage to work with and the current sink under the 6080 cathodes would end up dissipating way too much heat if it did.  If any signal managed to squeeze its way out of the amp, it would be horrendously distorted.
> 
> With the stock circuit, the situation is only 99% as bad as the situation above. The amp would still be useless in this configuration.
> 
> ...




Great, learned a lot here before making any mistakes. Much appreciate it!

6SL7 has an amplification factor of 70, which could be too high for Crack I guess (similar to the 12AX7 case discussed earlier)


----------



## Wes S

cddc said:


> Great, learned a lot here before making any mistakes. Much appreciate it!
> 
> 6SL7 has an amplification factor of 70, which could be too high for Crack I guess (similar to the 12AX7 case discussed earlier)


One can go to the bottlehead forum and the Crack tube rolling thread, has all the acceptable tubes listed.


----------



## cddc

Thanks a lot, mate! I read the list before, somehow the list is incomplete.

I like tube rolling...Bottlehead Crack /w Speedball is a wonderful tube amp to me in that it offers lots of fun rolling tubes and sounds sublime...I wish it came with a 6.3V to 12V heater switch someday...LOL


----------



## Wes S

cddc said:


> Thanks a lot, mate! I read the list before, somehow the list is incomplete.
> 
> I like tube rolling...Bottlehead Crack /w Speedball is a wonderful tube amp to me in that it offers lots of fun rolling tubes and sounds sublime...I wish it came with a 6.3V to 12V heater switch someday...LOL


There are tons of rolling options for the power and driver tubes, and the fact you only need one of each, really makes it fun and easy to find good tubes.  I am loving my BHC, and just rolled a new tube combo, that has me stunned.  I rolled in a Bendix 6080wb slotted plate/copper grid post and Sylvania gold brand 5814a triple mica grey plate and all I can say is WOW!


----------



## cddc (Aug 1, 2019)

Wes S said:


> There are tons of rolling options for the power and driver tubes, and the fact you only need one of each, really makes it fun and easy to find good tubes.  I am loving my BHC, and just rolled a new tube combo, that has me stunned.  I rolled in a Bendix 6080wb slotted plate/copper grid post and Sylvania gold brand 5814a triple mica grey plate and all I can say is WOW!




Indeed, a matched pair is always overpriced and harder to find compared to 2 singles...I think BHC is better than other tube amps for people who love tube rolling, coz it takes only one single driver tube and one single power tube. It makes rolling much easier.

Bendix 6080WB slotted graphite plates is one of the top 6080's...glad you enjoy it.


----------



## Wes S (Aug 1, 2019)

cddc said:


> Indeed, a matched pair is always overpriced and harder to find compared to 2 singles...I think BHC is better than other tube amps for people who love tube rolling, coz it takes only one single driver tube and one single power tube. It makes rolling much easier.
> 
> Bendix 6080WB slotted graphite plates is one of the top 6080's...glad you enjoy it.


Yes sir, a tube rollers dream amp, for sure!  The Bendix is a killer power tube, and I have tried several of the top tier power tubes, including the Tung Sol 5998, and the Bendix 6080wb is king.

My next roll, is the famous driver tube, the Amperex 7316 long plate, which should arrive tomorrow and we will see if it can dethrone the Sylvania 5814a triple mica.  The Sylvania dethroned the famous Mullard ECC82 long plate square getter, and that says a lot.

Happy tube rolling!


----------



## audiowize

cddc said:


> Thanks a lot, mate! I read the list before, somehow the list is incomplete.
> I wish it came with a 6.3V to 12V heater switch someday...LOL


This sounds like a good idea until you run the amp with the switch on 12V and a 6V tube installed.  Either you destroy the tube or the power transformer.


----------



## cddc (Aug 4, 2019)

audiowize said:


> This sounds like a good idea until you run the amp with the switch on 12V and a 6V tube installed.  Either you destroy the tube or the power transformer.




That won't happen.....hahah....won't run a 6V tube over 12V socket, or vice versa


----------



## m17xr2b

My stock bottlehead crack rebuild is finished. Next up, another one but overbuilt with speedball


----------



## L0rdGwyn

Crack on sale: https://bottlehead.com/product/crack-1-1-otl-headphone-amplifier-kit/

For those that haven't dabbled, the Crack is (in my opinion) the best introduction to headphone tube amplifiers, skip the hybrids.  Be warned, unless you have amazing self-restraint, be prepared to spend at least 2x of what you spend on the amp on tubes!


----------



## Wes S (Aug 9, 2019)

L0rdGwyn said:


> Crack on sale: https://bottlehead.com/product/crack-1-1-otl-headphone-amplifier-kit/
> 
> For those that haven't dabbled, the Crack is (in my opinion) the best introduction to headphone tube amplifiers, skip the hybrids.  Be warned, unless you have amazing self-restraint, be prepared to spend at least 2x of what you spend on the amp on tubes!


This is true! This amp is the best value around, and smokes everything under $1000.00, with ease.

I have a Bendix 6080wb Slotted Plate and Amperex 7316 tube combo, that is insanely good.  I am there with the musicians, as in sounds like real life.  Really could be endgame for many, including myself.


----------



## cddc (Aug 10, 2019)

m17xr2b said:


> My stock bottlehead crack rebuild is finished. Next up, another one but overbuilt with speedball




Looks gorgeous!

How did you get the mirror finish, you sanded it down or got it chromed by some shop?

Also, mind telling us where you got the choke and rectifier upgrades?  Thanks a lot.


----------



## hawkwindx

I have question I’ve searched for the answer to but haven’t had any success. 

I have LCD-3 headphones that are low impedance. I use them with the Audeze Deckard and JDS Labs “EL DAC”. 

Question - has anyone used the Bottlehead Crack hooked to a solid state amp like the Deckard? This would make the Bottlehead Crack a preamp to the Deckard. The way I would attach them is using a 3.5 mm to RCA cord, from the Bottlehead Crack headphone jack to the Deckard RCA input.

I’m wondering if this will add the “tube” sound to the Deckard?


----------



## L0rdGwyn

Good price on a 5998 here, over 100% emission, copper grid rods,  Seller accepts returns:

https://www.ebay.com/itm/273964706855?ul_noapp=true


----------



## jamwagon

To add to that, I saw this yesterday. https://www.ebay.com/itm/1-Vintage-...c-vacuum-tube-Ham-Radio-Amp-tube/333254276633
Ridiculous price. No test results posted though or returns accepted. Price seems low enough to take a chance though!

Oh BTW, Hi everyone! First time poster in this thread. Just wanted to introduce myself. I've interacted with a few of you one way or another through head-fi PMs, Reddit, or Bottlehead forums. I will definitely be posting some pics of my build and various tubes once I get the wooden base re-sanded/refinished. Currently looks like crap :\ but it sounds great!


----------



## L0rdGwyn

jamwagon said:


> To add to that, I saw this yesterday. https://www.ebay.com/itm/1-Vintage-...c-vacuum-tube-Ham-Radio-Amp-tube/333254276633
> Ridiculous price. No test results posted though or returns accepted. Price seems low enough to take a chance though!
> 
> Oh BTW, Hi everyone! First time poster in this thread. Just wanted to introduce myself. I've interacted with a few of you one way or another through head-fi PMs, Reddit, or Bottlehead forums. I will definitely be posting some pics of my build and various tubes once I get the wooden base re-sanded/refinished. Currently looks like crap :\ but it sounds great!




Welcome, @jamwagon !  Looking forward to it.

Yes, always risky to buy an untested tube, but hey, a $45 5998 is a steal if it worked out.  Weird print on that tube though, never seen that font on a 5998.


----------



## jamwagon

Thanks!

Yeah, I noticed that too. I'd want to ask the seller for more pics of the label including factory code, etc.


----------



## audiowize

jamwagon said:


> Thanks!
> 
> Yeah, I noticed that too. I'd want to ask the seller for more pics of the label including factory code, etc.


What would you hope to learn from this?


----------



## jamwagon

audiowize said:


> What would you hope to learn from this?


Welp, doesn't matter anyway. That sucker is SOLD! Figured it wouldn't last long


----------



## audiowize

jamwagon said:


> Welp, doesn't matter anyway. That sucker is SOLD! Figured it wouldn't last long


Gift horse, etc.


----------



## audiowize

hawkwindx said:


> I have question I’ve searched for the answer to but haven’t had any success.
> 
> I have LCD-3 headphones that are low impedance. I use them with the Audeze Deckard and JDS Labs “EL DAC”.
> 
> ...



This will put tubes in the signal path, but it won't add the "tube" sound IMO.  Part of the tube sound comes from the way tube amps interact (or don't interact) with the load your headphones present vs. a solid state amp.


----------



## SilverEars (Aug 14, 2019)

hawkwindx said:


> I have question I’ve searched for the answer to but haven’t had any success.
> 
> I have LCD-3 headphones that are low impedance. I use them with the Audeze Deckard and JDS Labs “EL DAC”.
> 
> ...


Crack is for dynamic drivers of 300+ ohms.  The reason why people like it is how the tube amp reacts to the dynamic drivers.  Solid states maybe more stable with whatever type of drivers, but you won't get sound like crack.


----------



## m17xr2b

I love rolling tubes on the crack, output mainly.  If I want something mellow with classic tube sound the GEC 6080 fits the bill, melodious and liquid Sylvania GB6080, allrounder Bendix 6080 solid plates, crisp clean and punchy Bendix 6080 slotted. If I want an event and amazement the GEC 6AS7G is just the ticket. It's mood dependant really. 5998 just doesn't get any use.


----------



## attmci

L0rdGwyn said:


> Welcome, @jamwagon !  Looking forward to it.
> 
> Yes, always risky to buy an untested tube, but hey, a $45 5998 is a steal if it worked out.  Weird print on that tube though, never seen that font on a 5998.


You'd better test it asap.

I have a lot of DOA 5998.


----------



## bequietjk (Aug 16, 2019)

Hi people!  I've yet to read ANY posts really on this thread.  But I ordered a Crack and can't wait to join the crew.  I've got 647 pages to go through?  Oh boy... 

Can't wait to pit my Project Horizon up against the Crack.


----------



## jamwagon (Aug 15, 2019)

attmci said:


> You'd better test it asap.
> 
> I have a lot of DOA 5998.



I didn't pick that one up. Someone did buy it that same day though! Whoever ended up with it hopefully got a great deal.

My first 5998 was untested and it has worked pretty well so far. Seller did accept returns so it would've went straight back.

Did the getter turn white on the right tube in your picture? Hard to tell but looks like a leak


----------



## attmci

jamwagon said:


> I didn't pick that one up. Someone did buy it that same day though! Whoever ended up with it hopefully got a great deal.
> 
> My first 5998 was untested and it has worked pretty well so far. Seller did accept returns so it would've went straight back.
> 
> Did the getter turn white on the right tube in your picture? Hard to tell but looks like a leak


All have problems.


----------



## SilverEars (Aug 18, 2019)

So, I've tried two OTL amps that have different amount of output impedance.  One is as low as 3 ohms and high as 10 ohms.  The Crack has magnitudes more in ohms being around 120 ohms or so

First of all, dynamic drivers of high ohms (Senny 300 ohms, etc..) reacts really well with OTL.  I don't believe the output impedance is why the heaphones react with such level of bass dynamism (hard, quick, and punchy), but the amp being OTL.  Something about OTL just really brings out the significant driver air movement.  It's like the area of air moved is much greater with OTL.

I don't believe this response is to be consider neutral in terms of amp response.  Interms of headphone response on the other hand, OTL may bring out more bass that's needed for the particular headphone, and becomes more balanced in the low-end as result, or just bass fun.  Why this type of bass dynamism is fun?  It's because bass isn't loose or muddy, but tight.  As long as bass is tight, significant level of bass is fine for me.


----------



## L0rdGwyn

SilverEars said:


> So, I've tried two OTL amps that have different amount of output impedance.  One is as low as 3 ohms and high as 10 ohms.  The Crack has magnatudes more in ohms being around 120 ohms or so
> 
> First of all, dynamic drivers of high ohms (Senny 300 ohms, etc..) reacts really well with OTL.  I don't believe the output impedance is why the heaphones react with such level of bass dynamism (hard, quick, and punchy), but the amp being OTL.  Something about OTL just really brings out the significant driver air movement.  It's like the area of air moved is much greater with OTL.
> 
> I don't believe this response is to be consider neutral, but if you experience such response, neutral becomes boring.



What OTL are you referring to with an output impedance of 3 Ohms?


----------



## SilverEars

L0rdGwyn said:


> What OTL are you referring to with an output impedance of 3 Ohms?


EC Zana Deux Super.


----------



## L0rdGwyn

SilverEars said:


> EC Zana Deux Super.



Oh I see, they use negative feedback to get the output impedance that low.  Interesting!


----------



## Maxhawk

L0rdGwyn said:


> Oh I see, they use negative feedback to get the output impedance that low.  Interesting!



I built an SRPP + 6080 headphone amp whose original design had negative feedback. It sounded good but didn't have the holographic imaging of the Crack. When I disconnected the feedback it resulted in the imaging I get with the Crack. I'm certain the distortion is higher but "no feedback" resulted in a much more satisfying experience.


----------



## L0rdGwyn

Maxhawk said:


> I built an SRPP + 6080 headphone amp whose original design had negative feedback. It sounded good but didn't have the holographic imaging of the Crack. When I disconnected the feedback it resulted in the imaging I get with the Crack. I'm certain the distortion is higher but "no feedback" resulted in a much more satisfying experience.



It's funny that you say this, as most objective engineering-type folks would say the negative feedback is the better choice: lower distortion, decreased output impedance, etc. but here you say that it has a detrimental effect on the subjective experience.

I'm no engineer, but I have a STEM degree, I try to keep myself educated on the scientific aspects of audio design.  I just think it's interesting how what is correct from an engineer's perspective and what measures well may not actually yield the most enjoyable listening experience.  How do you measure holographic imaging?  This type of debate is dividing a lot of audiophiles these days.


----------



## audiowize

One could certainly put feedback around the Crack circuit and get the output impedance super low, but it does indeed come with some negative side effects.  As Gwyn pointed out above, there are many objective benefits of global negative feedback, and it is present in nearly all currently manufactured audio components.  

Back in the day of vacuum tube amplifiers, the output transformer put a reasonable limit on the amount of GNFB that could be used before instability occurred, but with solid state amplifiers there is not such a hard limit.  Manufacturers learned that saying your amplifier had 0.001% THD at rated power vs. your competition's 0.01% THD drove sales, so this trend continued until enough subjective listening tests were done to determine that minuscule decreases in THD didn't always correlate to a better sounding amplifier.  Due to the subjective nature of this research, it took a few decades to be taken seriously, and that is about where we are now.


----------



## L0rdGwyn (Aug 18, 2019)

audiowize said:


> One could certainly put feedback around the Crack circuit and get the output impedance super low, but it does indeed come with some negative side effects.  As Gwyn pointed out above, there are many objective benefits of global negative feedback, and it is present in nearly all currently manufactured audio components.
> 
> Back in the day of vacuum tube amplifiers, the output transformer put a reasonable limit on the amount of GNFB that could be used before instability occurred, but with solid state amplifiers there is not such a hard limit.  Manufacturers learned that saying your amplifier had 0.001% THD at rated power vs. your competition's 0.01% THD drove sales, so this trend continued until enough subjective listening tests were done to determine that minuscule decreases in THD didn't always correlate to a better sounding amplifier.  Due to the subjective nature of this research, it took a few decades to be taken seriously, and that is about where we are now.



Very interesting, this is a topic I am going to read into more thoroughly.  I'd love to read some actual funded studies that do blind tests with GNFB vs no GNFB, tube vs. solid-state, etc.  I know the GNFB topic has been discussed ad nauseum.  This type of subjective, blinded research might shed some light.  It seems to me there is a lack of measurable parameters to fully describe the subjective experience.  Distortion alone is not telling the whole story.

I have owned a few solid-state amps, most recently the Arcam rHead and Violectric V100.  These amps never performed as well for me compared to say, the Crack, Crackatwoa, or my Glenn OTL.  I am certain if you measured them both with an audio analyzer, the solid-state amps would come out on top, especially when it comes to distortion and output impedance, but it just does not translate to the actual listening experience for me.  Maybe I am smitten by shiny, glowing orbs and it is feeding a placebo effect, but I doubt it.  There is a realism and three-dimensional listening experience you get with these tube amps, a sort of haze that is lifted compared to solid-state, for me.  The Violectric V100 is also more expensive that the Bottlehead amps and even the base model GOTL, so it is not a matter of dollars spent.  To be fair though, I have not listened to the absolute TOTL solid-state amps.  Even if they matched or exceeded the tube OTL listening experience, the tube amps would then be the smarter choice from a financial perspective.

Do you have an engineering background, audiowize?  You seem very knowledgeable on the technicalities.


----------



## Maxhawk

I suspect one reason that a lot of people like tubes, especially circuits without negative feedback, is the presence of even order harmonics. I know there have been attempts to add these harmonics in solid-state circuits, but I don't recall any formal conclusions. I used to fuss over distortion and frequency response measurements, but now I use those only as a guide when fine tuning circuits. If you care, you might check out some measurements I did years ago with the Crack and different tubes: https://imgur.com/a/dRFeJ


----------



## L0rdGwyn

Maxhawk said:


> I suspect one reason that a lot of people like tubes, especially circuits without negative feedback, is the presence of even order harmonics. I know there have been attempts to add these harmonics in solid-state circuits, but I don't recall any formal conclusions. I used to fuss over distortion and frequency response measurements, but now I use those only as a guide when fine tuning circuits. If you care, you might check out some measurements I did years ago with the Crack and different tubes: https://imgur.com/a/dRFeJ



Aha!  Those are your measurements?  I have referenced them many times, thank you for posting them!  To my knowledge, they are the only measurements of the Crack done using different input and output tubes.

If I am not mistaken, they were done without the Speedball installed.  Would be very interested to see how they compare with it.

A hobby project I would like to pursue in the near future is to build an affordable, at home audio analyzer setup, most likely using the QuantAsylum QA401.  I think it would be fun to measure the distortion profiles of my tube amplifiers and try to match my subjective preferences to a specific profile.


----------



## Maxhawk

L0rdGwyn said:


> If I am not mistaken, they were done without the Speedball installed. Would be very interested to see how they compare with it.



The measurements were taken with Speedball. It was also my first experience with tubes thus my fascination with taking measurements and trying to correlate them with my favorite tube combos. At the time my favorite output tube was the slotted graphite 6080, which happened to be the one with the highest measured distortion. Perhaps if I need to go back and do an FFT measurement with different output tubes....


----------



## Toad_of_Toad_Hall

I highly recommend this small change to the Crack if you are having trouble with noise from a digital source:

https://forum.bottlehead.com/index.php?topic=11676.0

For those of you who are too lazy to click the link, this is what Paul Birkeland says:

"For those who can hear their computer working away through their Crack or who are using a powerline ethernet kit and hear lots of clicking and static, a ground breaker installed in place of the buss wire between the chassis and the ground tab of the IEC power entry module will very likely solve this issue.  I recommend using a diode that's rated for at least 2A, and the voltage isn't particularly important.  Part number STTH2R06 looks to be a solid choice.  I do not recommend using a Schottky diode here."

I used 2 x 1N5408 diodes instead and they work well. Best mod you can make: Obvious and beneficial results and it only costs a couple of bucks.

Image is Paul's and added for convenience.


----------



## m17xr2b

My crack is almost complete, still can't find a matching volume knob. 

Custom Sowter 50W transformer
Custom laser cut and chromed top plate and wood chassis.
Duelund 20 and 26AWG OCC copper with cotton wiring.
Dual choke UK made. 
2x220uF Jensen caps and 3x50uF oil output caps with Duelund bypass
100uF Mundorf Evo Oil output caps with VCap TFTF 0.15uF bypass
TKD 2511 pot
NiMh battery bias instead of led. 
Cree diodes
About 40 hours of work. 

           

I still have a few things to do and overall I'm very happy with how it sounds. I rotate the output tube between GEC 6AS7G and 6080, Bendix solid and slotted and Sylvania 6080GB. I do have the 5998 but it's pretty much unused.


----------



## JamieMcC (Sep 22, 2019)

m17xr2b said:


> My crack is almost complete, still can't find a matching volume knob.
> 
> Custom Sowter 50W transformer
> Custom laser cut and chromed top plate and wood chassis.
> ...



Sure looks like you have had a blast building your Franken Crack. There used to be a real fun thread on the bhf with these sorts of builds in might have been capacitor porn or something along those lines, it was a blast to follow some of the crazy builds.

I'm off to google NiMh battery bias


----------



## L0rdGwyn

m17xr2b said:


> My crack is almost complete, still can't find a matching volume knob.
> 
> Custom Sowter 50W transformer
> Custom laser cut and chromed top plate and wood chassis.
> ...



https://www.partsconnexion.com/ANKNOB-81888.html
https://www.partsconnexion.com/ANKNOB-81897.html


----------



## Tom-s

Tonight i've had a first few hours with a Telefunken 6080WA output tube. A tube i previously thought off as non-existent with only fakes on the market. 
Bought it by chance, as is. Tested it >100% NOS, lucky me!
Telefunken only produced +- 27.000 6080's and 9.000 6080WA's (i have a 1965 6080WA). 
For comparison, the rare and wanted ECC803s almost 150.000 pcs. The 6080WA is as rare as the EC8020. 
The cheap ones found on ebay and other websites are mostly Telefunken faked GE / RCA / Thomson (France) tubes (the last ones sound good aswel!).
Read about the fakes here https://jacmusic.com/nos/images/Fakes/

Never read about these on this forum nor found a review. So it was a gamble for me.
How does it sound? Clear, open, detailed. It's just turning up the typical Telefunken sound another notch.
It's a tube to look out for! Definitely! And you can easily identify them by build (see Jac).
The tubes.rs ones are the real ones.


----------



## cddc

m17xr2b said:


> My crack is almost complete, still can't find a matching volume knob.
> 
> Custom Sowter 50W transformer
> Custom laser cut and chromed top plate and wood chassis.
> ...



Very nice mod! 

It's the first time I saw dual choke on BHC...used to see only single choke before.

Must be very good at electronics to figure out all these fancy mods!


----------



## cddc

Why the fu*k Amperex gives a flash when powering on?

I almost had a stroke this afternoon seeing the flash...thought it's arcing, so immediately unplugged my HD800 and put on a pair of crappy testing cans.

But it turned out to be OK, and I realized it could be something like the famous "Mullard flash", am I right?


----------



## Tom-s

cddc said:


> Why the fu*k Amperex gives a flash when powering on?
> 
> I almost had a stroke this afternoon seeing the flash...thought it's arcing, so immediately unplugged my HD800 and put on a pair of crappy testing cans.
> 
> But it turned out to be OK, and I realized it could be something like the famous "Mullard flash", am I right?



You are correct. This is a normal phenomenom with tubes, mostly seen in European or Philips tubes. Wether they are branded Amperex, Mullard, Valvo, Siemens, Philips, Adzam etc. It also happens on GEC's i.m.e.  Most American brands and the European counterparts (Brimar for instance) use a controlled heater warmup, which eliminates the flash and supposedly prolongues valve life. Telefunken also uses controlled heater warmup for its valves. 

A word on the Telefunken 6080WA. After a few evenings of listening i can't get it to sound optimal. It has the typical Telefunken sound but lacks in lower end (extension).
This makes it an awesome tube, but only for those wanting to make their system as detailed as possible. I prefer the Bendix/GEC type 6080 sound.
A picture on the night stand, with a Heerlen E80CC to fatten up the sound without losing quality (also comes with "Mullard flash"  ).


----------



## JamieMcC

E80cc is a superb tube there is a very simple and inexpensive mod on the bhf which allows you to run this tube in its sweet spot voltage wise well worth doing if using this tube.

From what I understand the E80cc was only manufactured by two companies Tungsram (Hungary) and Philips/Siemens (Holland).  Any E80cc with other branding are more than likely to have been manufactured in Philips Heerlen plant who were suppliers to many other brands such as Amperex, Miniwatt, Valvo, Mullard, La Radiotechnique RTC, Siemens  Adzam


----------



## cddc

Tom-s said:


> You are correct. This is a normal phenomenom with tubes, mostly seen in European or Philips tubes. Wether they are branded Amperex, Mullard, Valvo, Siemens, Philips, Adzam etc. It also happens on GEC's i.m.e.  Most American brands and the European counterparts (Brimar for instance) use a controlled heater warmup, which eliminates the flash and supposedly prolongues valve life. Telefunken also uses controlled heater warmup for its valves.
> 
> A word on the Telefunken 6080WA. After a few evenings of listening i can't get it to sound optimal. It has the typical Telefunken sound but lacks in lower end (extension).
> This makes it an awesome tube, but only for those wanting to make their system as detailed as possible. I prefer the Bendix/GEC type 6080 sound.
> A picture on the night stand, with a Heerlen E80CC to fatten up the sound without losing quality (also comes with "Mullard flash"  ).



Cool...so there are indeed Amperex flash, Mullard flash, Valvo flash...all kinds of flashes. 

I'm normally on U.S. tubes, the only European 12AU7 that I have is a Telefunken, but it does not give start-up flashes. So was terrified yesterday to see the "Mullard flash"


----------



## cddc

A question regarding how to identify 12A?7 tubes: 

Say, sometimes you messed up with a bunch of 12AU7 / 12AT7 / 12AX7 tubes, and most of the print on tubes are gone, how can you tell a tube is a 12AU7 or 12AT7 or 12AX7?

They all look the same to me.


----------



## Tom-s (Oct 6, 2019)

Just look up the tube you think they are and compare internals with pictures. That usually works. With US tubes there's normally an etched engraving that gives away the type.
For Philips tubes there's a code on the lower part of the tube, or on the bottom.
If this all not works, test it on a tester and see how it does.

Best is to keep your ECC's organised. I use Sunware brand Q-line 22Liter boxes. These use an insert that is perfect fit for ECC's. About 200 pcs fit the top insert, with convenient separations.
Here's an example with ECC81's.  The bottom of these boxes hold the new in box ones. And these boxes are easily stackable. Saving space.
https://ep1.pinkbike.org/p5pb17835015/p5pb17835015.jpg

But, i have confess, many tubes end up on piles. For this, i use old shoe boxes (because, also stackable)... and they are not so organised.
Below an example with 6189's or close lookalikes (mostly 12AX7's from GE), so yes, these get messed up..
https://ep1.pinkbike.org/p5pb17835008/p5pb17835008.jpg

Edit: Removed pics, only links, as they are not very relevant for the topic.


----------



## cddc

Good idea, I should begin to label tubes and get a storage box for them, as the number is ever increasing 

Do you think if the etched code "12AU7" or "6SN7" can be erased by alcohol? 

I often use alcohol to clean tubes, and I find some print / stencil on tubes can easily be removed by alcohol, especially on these miniature glass bottle tubes.


----------



## audiowize

cddc said:


> Say, sometimes you messed up with a bunch of 12AU7 / 12AT7 / 12AX7 tubes, and most of the print on tubes are gone, how can you tell a tube is a 12AU7 or 12AT7 or 12AX7?
> 
> They all look the same to me.



In a Crack with no Speedball, you can run it with no 6080 and plug these tubes in. The 12AU7 will produce the expected plate voltage that's around 75V or so.  

A 12AX7 is going to show very, very high plate voltage.  With or without the Speedball, it's going to be up close to whatever your B+ is, so 180V DC or so.

A 12AT7 with a Speedballed Crack will show about 130V on the plates, and it looks like without the Speedball it will be fairly close to that.

You do not, under any circumstances, want to run the Crack with a 12AT7 or 12AX7 if it has a 6080 plugged into the octal socket.  I can't predict what would break first, there are too many choices!


----------



## cddc

Thanks very much for the practical method to ID 12A?7 family tubes without a tester. A very smart approach!

I won't risk my Crack with any of the 12AX7 or 12AT7 tubes for sure . I read your detailed explanation where I asked the question some pages earlier...and it etched onto my memory already 

Ideally the etched code like "12AU7"or "6SN7" should stay there after alcohol cleaning. But after cleaning one of my 6SN7 tubes with alcohol, I found the etched "6SN7" code on top of the bottle faded away...or maybe the golden paint on the etched code faded away...sadly I couldn't recognize the "6SN7" after cleaning 

So I'm concerned about the etched codes. If it is gone after cleaning, it would be very difficult to identify 12AU7 from 12AT7/12AX7 visually as all of them look the same.

PS: I grabbed a bunch of 12A?7 tubes with a pack deal some time ago, most of them are 12AU7, but 2 of them happened to be 12AT7 and 1 12AX7.


----------



## DenverW

So about two months ago I traded another headfier my amp for his bottlehead crack (w/speedball) and absolutely fell in love with it.  Too much love, as I’ve showered it with affection in the form of output and driver tube rolling.  I have to say that I’ve really enjoyed listening and experimenting with it.

So far I’ve tried:
RCA 6as7g (came with it, along with a stock 6080 I don’t recall)
Tung sol 6080
Tung sol 5998
Tung sol 7236

Driver tubes:
Jj/Tesla 12au7
Mullard 4003 
Phillips e80cc
Tungsram e80cc
Tung sol 12bh7a
RCA 12bh7a
Ken rad vt231 
Tung sol 6sn7gt mouse ears

I also have a Raytheon 6f8g I haven’t been able to test yet but I’m looking forward to trying.

I plan on building a second crack on my own for fun once a good enough sale pops up, which should help me learn the ins and outs of the amp.  Important because when it stops working, like it is right now, I won’t need outside help to get it running again.  

Until then I’ll just keep having fun reading about tubes and impressions!


----------



## cddc

Yes, building a Crack is a very pleasant project. You can learn a lot about the Crack by DIY.


----------



## Tom-s

Time for another tube family to try in Crack!
The Dull Emitter Transmitter 20 or DET20.
Also known as CV6, E1148, 7193, CV3601, 2C22, VR135, CV1135, NR80, CV2920, VT252 and by some other names. It had many!

Back in the 1900’/10’s, the first tubes were developed (Fleming diode -> R triode). You had bright emitters, those were the early tubes that could function as a light bulb because of the pure Tungsten filaments. Later-on came the dull emitters, you’ve guessed it, not so much of a light source and far more economic for use with a battery, as was common in the 1920’s.

This Dull Emitter name since stuck a bit in England. So when de E1148 prototype was released in the USA for UHF use, the British had to get their counterpart. These tubes go by various names and have one thing in common, both anode and grid are connected via top caps. Starting out as the 6J5 (a 12AU7 predecessor), i guess this family was developed with the prevention of oscillations at high frequencies in mind. This tube (named military Common Valve 6) played a major role in military equipement during WWII. DET20 was the name given to civil versions of this tube, sold by the Marconi company, but picked from both the GEC as Mullard production line.

Being so close to the 6J5 (6SN7/12AU7), these make for a perfect fit in our beloved OTL headphone amps. Maybe even with some extra special “sparkling highs”  (Because VHF tube, haha, bad joke...    .... ).






Top: E1148 (Hytron) and 7193 (Ken Rad)
Bottom: CV6 (Mitcham) and CV6 (Hammersmith)

The E1148 then is a one of the first in this family and was build in the USA and Hytron branded tube. It has it’s inners mounted horizontally. It’s British and other American relatives show a normal vertical construction. Here’s an example from a 1942 group of this type. As you see, these all show a pan getter. Later versions show a different mica construction over that getter of no getter? I might have to break one to find out exactly.

In the CV6 type, tubes can be found from various factories and most of them were Mullards made in Mitcham (D) or Blackburn (A). My only Marconi tube looks exactly the same as the CV6’s from the Mullard line. I can’t spot any difference in internal structure. The plates of these area smaller then 6J5’s and charcoaled black for better heat radiating performance being welded together.

The 7193 is the American sibling, with the same construction/look as a 6J5 metal base (the normal ribbed plates), but with the same top-caps. They are fysically smaller compared to the EU counterparts and E1148 predecessors. In 7193’s there’s 2 versions i’ve seen. The Ken-rad, distinguischable via the top mica spacer from the National Union version (round mica).

When using these, please take extra care for the correct position of both the anode cap and grid cap!! Don’t ever swap them! Mishaps possibly harm the tube and your amplifier.

Always look up the datasheet before putting them in your amp to check both the parameters and connections. Then put the guide-pin correctly in the socket. After that you place the top caps according to the datasheet. Before power-on, visually double-check if the datasheet is correct for your tube (just look trough the glass and follow each connection).

Because i couldn’t find any datasheet on the E1148 (only the mention of it in the CV6 datasheet), i played around with it a bit longer before amplifier testing. For this, "used" specimens from 1942-1944 era were tested. All tests were done with 250V anode, -5,5v grid and show +- 8,2Kohm plate resistance, amplification factor 21, mutual conductance 2,5-3 ma/V with 13-15ma output. So close enough to CV6 (and same pinout) for the use of that same datasheet (+-NOS). So, these tubes are interchangeable and very usable as driver in Crack!





Picture: Test setup E1148.

CV6 datasheet: http://www.r-type.org/pdfs/cv6.pdf
On page 3, mounting position is specified.
Note that the E1148’s and CV6’s in my collection all share the same mounting positions.

7193 datasheet:  http://www.r-type.org/pdfs/2c22.pdf
On page 2, mounting position is specified.
Note the differences!


Oh. *Sound*!
These are very, very, very good sounding tubes. These add layers and layers of texture to the music bringing out soooooo many details. Wow, just wow. I’ve got tons of tubes to choose from for my Crack, and these enter the top-10 out of nowhere. This makes me want to explore more odd-ball UHF over-constructed tubes with the right specs.

I’ve tried 6 or 7 pairs by now in my Crack and none have been microphonic or problematic with interference due to long wires. All test strong and perform even better!

For the money this family is impossible to beat! You can find a pair for 25€ or less and i found a “made in China” adapter for 25€ that is performing perfectly.

It’s more worthwhile buying a pair of these with an adapter vs any 6SN7/12AU7 that goes for the same price. In the states the 7193 Ken Rad would be the one i’d recommend. In Europe the CV6’s can be found at bigger retailers, for very convenient prices (a few Euro/pound each) but you have to ask for supply (as nobody uses them). My personal favorite is the Mitcham factory CV6.





Picture: Kings of the bunch, the Mitcham CV6. Used with Bendix 6080 driving AKG K340 electret/dynamic headphones. Yes, i still need to rework the adapter and rotate it 90 degrees.

All-in-all these tubes sound so good that i’m planning on researching further developments of the UHF group for a next, completely nuts, tube adventure!


----------



## bequietjk (Oct 12, 2019)

Excited to get my Crack built but i ran into a small bump in the road, cosmetically.



It's residue from the adhesive bubble wrap packaging.  Is there a good method or chemical to use to clean this that wont damage the laquer coating of the transformer?


----------



## m17xr2b

Testing out stock vs speedball. It's so nice to use the ECC32 without adaptors.


----------



## bryceu (Oct 21, 2019)

Info no longer needed.. thanks!


----------



## cddc

bryceu said:


> Is it normal to get loud pops while inserting the 1/4" headphone jack in to the BHC? I just picked up a used BHC+SB that looks very well built, but for some reason I'm getting very loud pops/cracks whenever I insert the headphones into the jack or even twist it slightly while fully inserted.
> The volume pot is at about 25% but adjusting it doesn't seem to make a difference. Afraid I'm gonna blow my HPs... :/




It's definitely not normal!

Could be bad tubes. If you have some spare tubes known to be good, just swap out the tubes one by one and see if pops/cracks would go away.


----------



## cddc

m17xr2b said:


> Testing out stock vs speedball. It's so nice to use the ECC32 without adaptors.




Nice work!

If I were to build my second Crack, I would wire it for 6SN7 as well so that I don't have to use an adapter. 

BTW, is there any tutorial to teach you how to wire the 12AU7 socket for 6SN7? I guess there should be some on BHC forum...need to dig them out...LOL


----------



## cddc

bequietjk said:


> Excited to get my Crack built but i ran into a small bump in the road, cosmetically.
> 
> 
> 
> It's residue from the adhesive bubble wrap packaging.  Is there a good method or chemical to use to clean this that wont damage the laquer coating of the transformer?




Sorry to hear that. 

I normally use 99% isopropyl alcohol to clean electronics, but not too sure if it will remove the adhesive residue or it will damage the coating. 

Not majored in chemistry myself...so we need expert with chemistry background to help out.


----------



## bequietjk

@cddc Thanks!  Upon installation that part ended up being on the backside of the setup so I gave it a few good scrapes and called it good!

Crack is all finished


----------



## cddc

@bequietjk You're welcome.

Happy listening.  Crack should strike you with its sublime sound...I was amazed at how good it sounded when I finished building it.


----------



## bequietjk

I have a Garage1217 6sn7 adapter for the 9 pin octal socket.  Will the stock Crack circuitry play well with it?  So i can get to using my 6sn7s?


----------



## attmci

bequietjk said:


> I have a Garage1217 6sn7 adapter for the 9 pin octal socket.  Will the stock Crack circuitry play well with it?  So i can get to using my 6sn7s?


Sure.


----------



## m17xr2b (Oct 24, 2019)

cddc said:


> BTW, is there any tutorial to teach you how to wire the 12AU7 socket for 6SN7?


I don't know if there is, should be simple enough to figure out and it's especially easy when you have numbered pins like belton sockets do.

I'm done with my crack. Very happy with how it sounds, every time I get home I get slight chills to fire it up. 
Surprisingly:
- removed the duelund silver hybrid cast bypass cap on the psu
- removed the Vcap teflons on the output
- no speedball

My goal was to use the Crack more often, now it's a bit overboard as I'm only using it and neglecting the Stellaris.


The final build has:
Custom laser cut plate and wood case
Cree diodes
Jensen 220uF caps
Jensen 3X50 oil caps for the last one in the PSU
Mundorf evo oil 100uF output
duelund wireing
custom 50VA transformer
TKD pot
naked resistors
dual choke

Nerdy wet pants picture


----------



## Wes S

m17xr2b said:


> I don't know if there is, should be simple enough to figure out and it's especially easy when you have numbered pins like belton sockets do.
> 
> I'm done with my crack. Very happy with how it sounds, every time I get home I get slight chills to fire it up.
> Surprisingly:
> ...


Wow!  I would love to hear those, compared to my stock Speedball.


----------



## cddc

m17xr2b said:


> I don't know if there is, should be simple enough to figure out and it's especially easy when you have numbered pins like belton sockets do.
> 
> I'm done with my crack. Very happy with how it sounds, every time I get home I get slight chills to fire it up.
> Surprisingly:
> ...




Gorgeous mods...these are simply the ultimate BottleHead Cracks! 

Mind telling us a little bit differences in sound between the left one and right one that you perceived?


----------



## audiowize

cddc said:


> Gorgeous mods...these are simply the ultimate BottleHead Cracks!


No amount of parts swapping on a stock Crack will bring it up to the performance level of the Crack-two-a. Granted there's a lot of enjoyment in parts swapping.


----------



## m17xr2b (Oct 24, 2019)

If that were true the Crack-two-a should sound better than the Apex Teton since the teton has that capacitor in the power supply, and the teton is a more similar to a stock crack circuit design as it doesn't have any equivalent speedball even. Otherwise it's the same basic thing with tube rectification.

That's an old myth to stop people buying ridiculous caps, physically larger than the crack. When you have superior components overall, from a larger, better power transformer with complementary tubes and the Metrum Pavane as a dac you'll find it's not that simple.

I've been planning this crack for a long time. Had the Apex Teton for a year, super amp, in my top 3. Sold it as I already had two TOTL amps but still wanted that great OTL sound in a small package.

If I didn't have a quad of gec 6AS7G among other tubes I wouldn't have pushed 700-800£ for a glorified bottlehead crack.  Plus it gave me a reason to use the BL63 input tube, the best input tube I've ever heard.

This will compete with the DNA Stratus, WA22, Glenn OTL and other 2K+ amps easily.
The bottleneck on the Crack is the power transformer, but then if you replace it is it still a crack?


----------



## Wes S

audiowize said:


> No amount of parts swapping on a stock Crack will bring it up to the performance level of the Crack-two-a. Granted there's a lot of enjoyment in parts swapping.


I have been told this same thing, by someone who's ears I trust, but would love to hear one some day.


----------



## attmci

Some day? Here is the chance now: https://www.head-fi.org/threads/pri...quiet-stepped-attenuator-unique-build.916875/


----------



## proto65

Thinking about selling my crack soon and upgrading to an s.e.x., I want something that can drive my recently bought hd700s. How much money would a modded pre speedball crack fetch? I haven't seen any modded cracks without speedballs for sale. The mods I have done are: Cree Schottky diodes, upgraded caps (Audyn Cap Q4 MKP), and a Triad choke.


----------



## bequietjk

Dang, I gotta say.  My Grado SR80e sound WICKED with the Crack.  Before I foud them to be pretty fatiguing on long listening sessions but now?  Nah.  It's tolerable and wonderful.  NOW i'm curious to hear the rest of the Grado line-up.


----------



## cddc

bequietjk said:


> Dang, I gotta say.  My Grado SR80e sound WICKED with the Crack.  Before I foud them to be pretty fatiguing on long listening sessions but now?  Nah.  It's tolerable and wonderful.  NOW i'm curious to hear the rest of the Grado line-up.




Dude, Crack works best for the high-Z headphones, like HD650, HD600, HD800, T1, etc

Never had a Grado myself, but I think most Grados are low-Z headphones, which are not suitable to Crack.

If you mainly play with Grados, you should grab a Bottlehead Mainline


----------



## bequietjk (Oct 26, 2019)

@cddc I have my babies right next to me (HD600s).  But I feel like it isn't as exciting as hearing the sr80e.  For me, the Crack has tamed the brightness and has unlocked the bass in the sr80e.  With the HD600 I feel like they are being pushed well enough but is VERY tube dependent.

I'm on about 50 hours of break in with the Crack.  I don't expect much with another 50 hours, but I'm still evaluating the HD600 paired with it and the hype that propelled me into building it.

A Syl 6080 was supplied with it along with an RCA 12au7.

Currently I'm using a RCA 6080 + GE 6189 12AU7.  This combo sounds awesome.  Tight and controlled lowers, the mids get tamed a bit and the highs seem smooth atm.


----------



## cddc

It's pure personal preferences over headphones...i figure you're a big Grado fan  

From what I read on this thread, Crack works best for high-Z headphones, and Mainline or S.E.X works for both high-Z and low-Z headphones. But I'm glad to hear that Crack also works well for your Grados.


----------



## cddc

I saw some boards behind your Crack, are you building another Crack for a friend
*@bequietjk*...lol?


----------



## bequietjk

@cddc ok, so about the boards...

I found out I melted my on/off switch after completing my board.  It was the only negative about my experience!  So, luckily the manual has a troubleshooting page and the switches are readily available.  Now, I knew I wanted a SOLID stain and color for the amp and good thing you can order replacement boards.  Of course I bought some!  Why not.  Might as well get some shipped with the switch! 

Tomorrow I'll be practicing MINWAX oil based staining along with Keda Dye that I purchased.  The Keda Dye owner has a youtube video of him completing a project using his dye and the colors look friggin' amazing.  Especially the dark aqua green that I'm going for.

Also, I might build another Crack for my grandpa   So, yeah, I guess you could say I'm building another.. possibly ^.-


----------



## cddc

LOL...someone with soldering skills is hard to find, your grandpa will definitely find you handy.


----------



## bequietjk

It just dawned on me...

Considering i have yet to finish my alder boards, ive noticed the amp plate gets pretty damn hot and was wondering if there is a choice finish for this?  Is it a good idea to get a certain type of clear finish that can with stand the heat, or method that should be considered?

I have clear gloss minwax polyurethane.


----------



## cddc

bequietjk said:


> It just dawned on me...
> 
> Considering i have yet to finish my alder boards, ive noticed the amp plate gets pretty damn hot and was wondering if there is a choice finish for this?  Is it a good idea to get a certain type of clear finish that can with stand the heat, or method that should be considered?
> 
> I have clear gloss minwax polyurethane.



Have you installed the Speed Ball?

I think before installing the SB, the plate was kind of hot (but not damn hot) due to the pair of white wirewound resistors under the heat sink. I only had stock Crack for couple of nights and quickly upgraded to SB, so not too sure about the plate temp on stock Crack. Then with SB upgrade the pair of wirewound resistors were removed, and I believe the plate temp dropped significantly.

But even without SB, the plate temp of stock Crack is still okay IMO, maybe a little bit hot, but definitely not stupid hot. So I never had any concern on the paint. BTW, I used Rust-Oleum paint on my Crack.


----------



## audiowize

bequietjk said:


> I've noticed the amp plate gets pretty damn hot and was wondering if there is a choice finish for this?


If your amp passed the voltage checks, then it is running as hot as any other working Crack.  The kit has been out for over a decade with no reports of failing wood finished from heat, and consequently I would suggesting using whatever you like.


----------



## audiowize

cddc said:


> Have you installed the Speed Ball?
> Then with SB upgrade the pair of wirewound resistors were removed, and I believe the plate temp dropped significantly.


The heat dissipated under the chassis goes up when the Speedball is installed.

The localized heating of the chassis plate right where those 10W resistors sit will decrease when the Speedball is installed.  

(Always remember to install the rubber feet too)


----------



## cddc

audiowize said:


> The heat dissipated under the chassis goes up when the Speedball is installed.
> 
> The localized heating of the chassis plate right where those 10W resistors sit will decrease when the Speedball is installed.
> 
> (Always remember to install the rubber feet too)



I don't have any equipment to test the temperature, but I think the temp on Crack w/ Speedball is okay, the plate just feels warm, but never hot.

I am not sure if SB will increase or decrease the temp, but I think the 2 dissipators sitting on top of the SB board help to dissipate heat to the air around them thus reduce the heat conducted to the plate like the wirewound resistors do. So it could give me a biased impression that SB reduces the plate temp.


----------



## audiowize

The large Speedball board heatsinks dissipate the same amount of heat as the 3K resistors do, but both the large Speedball board and the small Speedball board have some additional current flowing through them to permit the current sources to operate, so the overall heat dissipated inside the chassis is a bit higher.

The Speedball boards are not as close to the chassis, so what would be heated locally by the 3K resistors is a bit more spread out to the entire chassis after the modification.


----------



## bequietjk

I scooped a 'Zaerix' branded power tube from ebay, suppose to be a 6as7g.

Look familiar to anyone?  I wonder what its parent company is!


----------



## m17xr2b (Nov 11, 2019)

Russian rebrand. Edit: Still a good tube, nice bass.


----------



## cddc

bequietjk said:


> I scooped a 'Zaerix' branded power tube from ebay, suppose to be a 6as7g.
> 
> Look familiar to anyone?  I wonder what its parent company is!




Buddy, this is 100% a Svetlana 6H13C or 6H5C from Russia, I have couple of these as well. 

Did you see the 2 flying UFO getters right above the base, it is a telltale of Russian tubes.


----------



## cddc

You can often find lots of rebrands of Svetlana 6H13C/6H5C, sometimes they are rebranded as Hytron, Mullard, and even GEC, and asking for a premium for them, but really they're just Russian 6H13C/6H5C and are not worth that much. Hope you didn't pay big bucks on the 'Zaerix'. You can easily find Svetlana 6H13C/6H5C for $8 - $15.

That said, Svetlana 6H13C/6H5C is a decent tube, it sounds much better than the crappy RCA 6080.


----------



## bequietjk

Nice!  Is it the ssame as the Winged C?  I paid $28 for it to be shipped overseas.  It's not a bad tube, though there are aspects about my RCA 6080 that I like more than the Zaerix that keep the RCA installed.

Those 2 space-plates are funny looking!  They just kind of dangle there.  

I'm really curious of the RCA 6AS7G.


----------



## cddc (Nov 11, 2019)

bequietjk said:


> Nice!  Is it the ssame as the Winged C?  I paid $28 for it to be shipped overseas.  It's not a bad tube, though there are aspects about my RCA 6080 that I like more than the Zaerix that keep the RCA installed.
> 
> Those 2 space-plates are funny looking!  They just kind of dangle there.
> 
> I'm really curious of the RCA 6AS7G.




Yes, it is the same as Winged C. Svetlana's logo has a big C with wings, so it's called Winged C






Some people like the RCA 6080s, especially if they're mainly on vocal albums. RCA is famous for its warm mids - good for vocals for sure. But I really don't care for it, lack of details and soundstage, really nothing but warm, YMMV, LOL.

RCA 6AS7G sounds similar to RCA 6080, I have both, and neither of them grabs my attention, LOL


----------



## Wes S

Tung sol, makes really good power tubes for the crack, and is my recommendation.

Tung Sol - 6080 and 6AS7G, are all really good power tubes, in the crack.


----------



## Conotocarius

Wes S said:


> Tung sol, makes really good power tubes for the crack, and is my recommendation.
> 
> Tung Sol - 6080 and 6AS7G, are all really good power tubes, in the crack.


I have that Tung Sol in my crack (!) and I agree it's great.  seems to gel well with tfunken ecc82


----------



## bequietjk

Have to cut each character out (Attack on Titan) and play with arrangement.  Probably have Mikasa in the front with the bottlehead badge.

Does anyone have recommendation how i should apply these decals?  I was thinking of letting the polyurethane dry, then using a gluestick on the decals, then apply...


----------



## bequietjk

DONE!


----------



## m17xr2b

You made me realise I never put the badge on mine. Thx.


----------



## Wes S

bequietjk said:


> DONE!


That came out quite nice!


----------



## JTori

m17xr2b said:


> You made me realise I never put the badge on mine. Thx.



Interesting build. I'd like to know more about the input tube and any other mods you've made to your Crack.  Mine's a little more pedestrian, save for some tube rolling.

Best,

Joe.


----------



## m17xr2b

The input tube is a CV1102, I really like it and decided that's to only input tube I'll use in the crack and just roll output.  Can't be used in a stock crack due to 1.3A of heater requirement and different pin config
The more notable things I've put in it:
Jensen 220uF x2 audio electrolytic caps
Jensen 50uF oil x3 for the last cap in the PSU
Mundorf 100uf evo oil for output
Dual UK made choke
Battery bias instead of LED for the input tube
No Speedball
Custom overspeced transformer - this runs really cool compared to stock.
Duelund 26AWG wiring
TKD volume pot
Charcroft Z-foil resistors where I could.


----------



## JTori

m17xr2b said:


> The input tube is a CV1102, I really like it and decided that's to only input tube I'll use in the crack and just roll output.  Can't be used in a stock crack due to 1.3A of heater requirement and different pin config
> The more notable things I've put in it:
> Jensen 220uF x2 audio electrolytic caps
> Jensen 50uF oil x3 for the last cap in the PSU
> ...



Wow!  Very interesting build!  I'm sure it sounds awesome.  Did you construct a new, larger base to accommodate everything?


----------



## m17xr2b (Nov 29, 2019)

Yes, custom plate and wood base, actually there's no bottlehead kit part in it, not even a nut.

It does sound pretty baller, but then again it's a 1K amp at this point. Still, there's something about the crack circuit that hits the sweet spot. It's my daily amp but might as well be end game. My main amp is the DNA Stellaris.


----------



## JTori

Very impressive and well thought through!  I agree with you, the Crack circuit is elegant in its simplicity; BH has taken time to distill the design to its essence, not always easy to achieve.  I don't know how many Crack kits they sell per year, but in my opinion it's not as many as they should.  And, the company is a prime example of how to build a loyal customer base:  highly responsive to DIY'ers' inquiries and a thriving discussion forum.  I've built both the Crack/Speedball and the Mainline.  My Crack is bone stock, while I did pop a pair of 10uF Mundorf Supremes in the Mainline.  I love both amps.  I'm not contemplating replacing my longtime ARC/Magnepan/Vandy sub rig with a pair of Kaijus, a BeePre, an Eros 2 and a pair of Jagers.

Once more, nice work!


----------



## Toad_of_Toad_Hall (Dec 1, 2019)

.


----------



## DenverW

Here’s an adapter question for the tube experts!  I have multiple adapters for a 6sn7 based darkvoice amp.  Things like 6f8g and 7193 adapters.  Rather than purchase multiple adapters for these going into 12au7 would I be able to use two adapters at once?  For example, 6f8g to 6sn7 adapter —> 6sn7 to 12au7 adapter—> crack w/speedball?

May not be the prettiest, but if it would work it would save time and money!  I would thiiink it should be ok?


----------



## m17xr2b

Toad_of_Toad_Hall said:


> Did you pay Bottlehead for the use of their design? I wonder how Doc & co would feel about this build. At what point does a Crack stop being a Crack?


The right question is if I ever bought a new crack before to have access to the manual. The answer is yes and other kits as well.
Why did you feel the need to post this question? Go back to the swamp.


----------



## Toad_of_Toad_Hall (Dec 1, 2019)

.


----------



## m17xr2b (Nov 30, 2019)

Not being rude, just making fun of your nickname, because you're a toad. Still, your accusation is quite severe and in a public forum yet you failed to mention exactly what I did or what I shared that not already public.

Why are you picking on my build, who are you? Are you really a toad? If DocB wants me to redact anything fine by me, I love bottlehead and learned to do this because of their kits especially the BeePre.

Crack modding is a culture by now and I couldn't use anything from the kit for my purpose not even the transformer and top plate, I don't get the SJW attitude.


----------



## Wes S

m17xr2b said:


> Not being rude, just making fun of your nickname, because you're a toad. Still, your accusation is quite severe and in a public forum yet you failed to mention exactly what I did or what I shared that not already public.
> 
> Why are you picking on my build, who are you? Are you really a toad? If DocB wants me to redact anything fine by me, I love bottlehead and learned to do this because of their kits especially the BeePre.
> 
> Crack modding is a culture by now and I couldn't use anything from the kit for my purpose not even the transformer and top plate, I don't get the SJW attitude.


I would love to hear that thing, and bet it sounds awesome!  Really cool to see different builds!  Thanks for posting


----------



## m17xr2b (Nov 30, 2019)

DenverW said:


> Here’s an adapter question for the tube experts! I have multiple adapters for a 6sn7 based darkvoice amp. Things like 6f8g and 7193 adapters. Rather than purchase multiple adapters for these going into 12au7 would I be able to use two adapters at once? For example, 6f8g to 6sn7 adapter —> 6sn7 to 12au7 adapter—> crack w/speedball?


I did chain adaptors for other amps, not pretty but it does work, you will increase the chance of static and noise but if it works fine you should be good to go.



Wes S said:


> I would love to hear that thing, and bet it sounds awesome! Really cool to see different builds! Thanks for posting


If you're ever in London...


----------



## audiowize

For those who may consider a larger/cooler running transformer to be some kind of improvement, it's worth remembering that underloading a transformer leads to poor regulation, and poor regulation can leave your 6.3V heater winding putting out far more than 6.3V, which can reduce tube lifetime.

I had someone bring by a Singlepower MPX3 that someone had "improved" by adding a really heavy duty power transformer.  The heater winding was putting out over 7V, and this is not so great for tube life.


----------



## m17xr2b

audiowize said:


> For those who may consider a larger/cooler running transformer to be some kind of improvement, it's worth remembering that underloading a transformer leads to poor regulation, and poor regulation can leave your 6.3V heater winding putting out far more than 6.3V, which can reduce tube lifetime.


I doubt anyone would consider a larger transformer but you are right. Normally my transformer would run at about 6.7V but brought down to 6.3V. This is detail a bit beyond the typical DIYer for the crack.  I do like a load of 60-70% of the rating.


----------



## audiowize

The stock transformer is spec'd at about 105VA and runs under 50VA.


----------



## m17xr2b

Doesn't make sense, the stock crack runs at 30W and it's not anywhere near 105VA for spec.  My 2A3 amp runs at 100VA. Are you sure it's the crack you're thinking of?


----------



## audiowize

The Crack transformer is also in the SEX amp, and that's the clue to the capacity of the HV winding.  From the original SEX amp and Crack 1.0, that indicates a high voltage winding capacity of 72VA and a LV winding capacity of 22VA, so I guess it's only 94VA.  This is to keep the transformer cool enough to touch without harm, but the materials undoubtedly would tolerate more heat.  The Crack transformer can power a 2A3 monoblock quite easily.


----------



## m17xr2b

That's not really fair, you'll need two transformers for a stereo 2A3 amp. 72VA HV...winding, are you sure? I've already been accused of intellectual property revealing so I can't give out the full numbers but it's closer to 15VA. As confirmed on the BH forum there's around 70mA of total current.
The transformer I had was the original 1.0 for 240V and it got pretty warm to hot. Not that that's an issue.


----------



## audiowize

I sure hope the winding isn't 15VA, the Crack amp draws more than 30VA from that winding; the SEX amp draws more.  

AC and DC current are not the same.  The transformer only cares about AC current.


----------



## Toad_of_Toad_Hall (Dec 1, 2019)

.


----------



## Toad_of_Toad_Hall (Dec 1, 2019)

*.*


----------



## audiowize

I don't see any words of encouragement there, that seems to be your addition to the conversation.


----------



## Toad_of_Toad_Hall (Dec 1, 2019)

.


----------



## audiowize

Toad_of_Toad_Hall said:


> Not sure what you mean.


Encouragement would be saying something like "go ahead and do it".  The statement that there are many mistakes in the clones is some evidence that there isn't approval on that end.  I don't see any encouragement in anything you've posted from that statement.  The statement also talks about modifying kits, not copying them.  

I read that more as "it happens, and we don't encourage it, but we aren't filing lawsuits every time someone does something crappy".  Being cranky toward your customers is a good way to go out of business.  

You never know, M17 may have even asked for permission from Doc B.


----------



## Toad_of_Toad_Hall (Dec 1, 2019)

A full and unequivocal apology is due to @m17xr2b . Enjoy your amp.

Sometimes grey areas are best left grey.


----------



## bequietjk (Dec 3, 2019)

Does anyone know the conductor material used in the Crack cord?  Is it solid or stranded silver?


----------



## audiowize

bequietjk said:


> Does anyone know the conductor material used in the Crack cord?  Is it solid or stranded silver?


Solid core copper. If it appears to be silver, it is tinned to prevent the copper from oxidation, which is not at all abnormal and will allow the wire to be reworked easily at a later point.

Stranded wire should not be used for these purposes.


----------



## bequietjk

@audiowize in the *power cord?


----------



## audiowize

Most IEC power cords will be stranded copper with a PVC jacket.


----------



## attmci

audiowize said:


> The Crack transformer is also in the SEX amp, and that's the clue to the capacity of the HV winding.  From the original SEX amp and Crack 1.0, that indicates a high voltage winding capacity of 72VA and a LV winding capacity of 22VA, so I guess it's only 94VA.  This is to keep the transformer cool enough to touch without harm, but the materials undoubtedly would tolerate more heat.  The Crack transformer can power a 2A3 monoblock quite easily.


The Bottlehead transformer is cool for it's size, but could also be the bottleneck....


----------



## TylersEclectic

Messing around with some tubes loaned to me for playing with so I figured I would get a shot in. Thanks @raindownthunda  for allowing me the pleasure of hearing all these! super fun, and I can't wait to hear your experience with them once your Crack is completed!


----------



## Wes S (Dec 8, 2019)

Darthpool said:


> Messing around with some tubes loaned to me for playing with so I figured I would get a shot in. Thanks @raindownthunda  for allowing me the pleasure of hearing all these! super fun, and I can't wait to hear your experience with them once your Crack is completed!


Cool shot man!  What tubes are you using?


----------



## TylersEclectic

Wes S said:


> Cool shot man!  What tubes are you using?


In that picture I believe it’s a Chatham and a Brimar....on loan from @raindownthunda


----------



## Wes S

Darthpool said:


> In that picture I believe it’s a Chatham and a Brimar....on loan from @raindownthunda


Right on!


----------



## bequietjk

Ok final decal placement.  Didnt like the first go around.  

Crack finished...

Until i get the urge for new feet


----------



## TylersEclectic

@Wes S 

Sooo... I have on loan from @raindownthunda some of your favorite tubes....I'm impressed, they are quite excellent! Smooth/clean/detailed holographic... I've tried all the tubes at this stage...now to narrow it down to my favorite combos...but to be honest, I kind of like all of them...they all sounded great, just different flavors of great.
Amperex and Chatham


----------



## Wes S

Darthpool said:


> @Wes S
> 
> Sooo... I have on loan from @raindownthunda some of your favorite tubes....I'm impressed, they are quite excellent! Smooth/clean/detailed holographic... I've tried all the tubes at this stage...now to narrow it down to my favorite combos...but to be honest, I kind of like all of them...they all sounded great, just different flavors of great.
> Amperex and Chatham


Yes sir!


----------



## adydula (Dec 10, 2019)

Hey Darth!! My musical buddy!! :>)

I have the pretty much the exact same set of tubes in my Crack.

I have a bunch of Bugle Boy variants and 5963, JAN and others...

The Chatham tube is great....I also love the RCA 6AS7G's....those old NOS coke bottles are really neat to look at!!

Nostalgic!

Alex

Oh, I notice you have a "tall" device near it? Wireless router? Wonder if you get any interference from it?


----------



## TylersEclectic

adydula said:


> Hey Darth!! My musical buddy!! :>)
> 
> I have the pretty much the exact same set of tubes in my Crack.
> 
> ...


Hey! That device is my MacMini 2018, so far no interference....I usually keep my tube amps on my audio shelf, but it is on the opposite wall, so I moved the BHC to the desk for easier access for playing with it.


----------



## bryceu

Darthpool said:


> @Wes S
> 
> Sooo... I have on loan from @raindownthunda some of your favorite tubes....I'm impressed, they are quite excellent! Smooth/clean/detailed holographic... I've tried all the tubes at this stage...now to narrow it down to my favorite combos...but to be honest, I kind of like all of them...they all sounded great, just different flavors of great.
> Amperex and Chatham


Dig the all-black paint job. That's what I'm probably going for with my build whenever it happens.


----------



## TylersEclectic

bryceu said:


> Dig the all-black paint job. That's what I'm probably going for with my build whenever it happens.


It’s a fun build! I kind of want to build another one or maybe a S.E.X. Next...also, the fun thing is you can build multiple bottom cases if you get bored with your first one =) I believe @raindownthunda is building a Crack now...hopefully he takes lots of pictures documenting it and shares his experience! I think his will turn out pretty dope looking!


----------



## DenverW

So I’m super excited, as I finally replaced the piece of my crack I needed to, and it works again!

Since it took me so long, I’ve been using my darkvoice 336se in the interim, and it’s very interesting which tubes work better with different amps.  The 6c8g works gangbusters with the darkvoice, but isn’t a good pairing with the crack, sounding muted and veiled, but the 6f8g sounds great on the crack.  

I’ll do some more experimenting, since I enjoy tube variants quite a bit!


----------



## bequietjk

Has anyone had experience using an AC connector like this?  I'm wondering if it will work and if it can provide any benefit!
https://www.amazon.com/SCHAFFNER-FN9260SB-4-06-10-CONNECTOR-POWER-ENTRY/dp/B00OVEUH72


----------



## attmci

Darthpool said:


> @Wes S
> 
> Sooo... I have on loan from @raindownthunda some of your favorite tubes....I'm impressed, they are quite excellent! Smooth/clean/detailed holographic... I've tried all the tubes at this stage...now to narrow it down to my favorite combos...but to be honest, I kind of like all of them...they all sounded great, just different flavors of great.
> Amperex and Chatham


That's the best 12au7 for the Crack.


----------



## bequietjk

Is it true that installing Speedball will increase voltage swing?  Satisfying the hunger of our high impedence cans?


----------



## audiowize

bequietjk said:


> Is it true that installing Speedball will increase voltage swing?  Satisfying the hunger of our high impedence cans?


The Speedball will increase current delivery to the load at the output, which will increase available power. The stock circuit has a ton of voltage swing; that's rarely an issue.


----------



## swapheadfi

I've an OTL I got a year ago, still unopened, never got around to assembling it. Does anyone know how much it costs to get it assembled?


----------



## DenverW

swapheadfi said:


> I've an OTL I got a year ago, still unopened, never got around to assembling it. Does anyone know how much it costs to get it assembled?



If you can, I strongly recommend setting it up yourself.

I ended up buying a preassembled crack from another head Fier.  After about 2 months, something shorted and it stopped powering in.  Because I hadn’t assembled it I wasn’t confident enough to diagnose and repair it.  Took 3 months for another guy to fix it for me.

During that 3 month period I actually got a kit from the cyber Monday sale, so I can build one myself in case this ever happens again.  I’ll either sell it or use it as a computer amp.


----------



## swapheadfi

Makes sense, I think over the time realized that I prefer portable and less bulky amps. I now use the AudioQuest Dragonfly (mostly), and JDSLabs ODAC/AMP. I want to try out the Bottle head crack but I've not gotten to it in a year. If I don't get to it in the next few days perhaps I may just list it for sale here


----------



## swapheadfi

DenverW said:


> If you can, I strongly recommend setting it up yourself.
> 
> I ended up buying a preassembled crack from another head Fier.  After about 2 months, something shorted and it stopped powering in.  Because I hadn’t assembled it I wasn’t confident enough to diagnose and repair it.  Took 3 months for another guy to fix it for me.
> 
> During that 3 month period I actually got a kit from the cyber Monday sale, so I can build one myself in case this ever happens again.  I’ll either sell it or use it as a computer amp.



Makes sense, I think over the time realized that I prefer portable and less bulky amps. I now use the AudioQuest Dragonfly (mostly), and JDSLabs ODAC/AMP. I want to try out the Bottle head crack but I've not gotten to it in a year. If I don't get to it in the next few days perhaps I may just list it for sale here 


DenverW said:


> If you can, I strongly recommend setting it up yourself.
> 
> I ended up buying a preassembled crack from another head Fier.  After about 2 months, something shorted and it stopped powering in.  Because I hadn’t assembled it I wasn’t confident enough to diagnose and repair it.  Took 3 months for another guy to fix it for me.
> 
> During that 3 month period I actually got a kit from the cyber Monday sale, so I can build one myself in case this ever happens again.  I’ll either sell it or use it as a computer amp.


----------



## swapheadfi

For anyone interested, I'm selling my unopened rig that I've put off assembling for over a year here https://www.head-fi.org/threads/fs-unopened-crack-1-1-otl-headphone-amplifier-kit.922005/


----------



## swapheadfi

swapheadfi said:


> Makes sense, I think over the time realized that I prefer portable and less bulky amps. I now use the AudioQuest Dragonfly (mostly), and JDSLabs ODAC/AMP. I want to try out the Bottle head crack but I've not gotten to it in a year. If I don't get to it in the next few days perhaps I may just list it for sale here



I'm going to part with it, I don't think I'll ever get to it.


----------



## bequietjk

Has anyone experienced AKG K712 with and without Speedball?  If the current delivery is better with the Speedball, I wonder how the power hungry K712 will take to it...


----------



## cobrabucket

swapheadfi said:


> For anyone interested, I'm selling my unopened rig that I've put off assembling for over a year here https://www.head-fi.org/threads/fs-unopened-crack-1-1-otl-headphone-amplifier-kit.922005/


Sweet deal for someone!


----------



## DenverW

So I’ve been using a 6f8g to 12au7 adapter with no problems.  Fun tube!  However, I’ve been having a weird issue with the 6c8g tube variant.  The 6c8g, which sounds great on my darkvoice, sounds muted on the crack, with distortion issues at the 9pm volume mark.  Normally I’d blame the adapter, but it works fine with the 6f8g, as well as with 6c8g on the darkvoice.  The 6c8g tubes I’ve been using all show this issue, then sound fine on the other amp.

any ideas?


----------



## audiowize

The 6C8G is not a substitute for a 6F8G/12AU7.


----------



## DenverW

Yes, I appreciate that.  I think my question revolves more around seeing others use the 6C8G in the crack with speedball, as well as having them work well in the dark voice 336se.  I was wondering what other people’s experience was, if they’d experienced something similar with the crack.


----------



## audiowize

They aren't even close. They will not work without a major redesign of the circuit. 

They might work a little better in the stock circuit if the LEDs were replaced with resistors, but you'd be moving backwards to use an inferior tube.


----------



## DenverW

Completed the power cord kit.  I did it just for a fun little DIY experience, figuring that would be it.  Looks like I was wrong thinking power cables make no difference.  I recommend adding this kit to your amp, its a winner.


----------



## raindownthunda

DenverW said:


> Completed the power cord kit.  I did it just for a fun little DIY experience, figuring that would be it.  Looks like I was wrong thinking power cables make no difference.  I recommend adding this kit to your amp, its a winner.



Awesome! How would you describe the difference?? I just completed my crack and was contemplating the power cord kit at some point...


----------



## DenverW

raindownthunda said:


> Awesome! How would you describe the difference?? I just completed my crack and was contemplating the power cord kit at some point...



sorry for the delay!  I’d describe the sound as smoother, overall.  I’m not a poet, but I find a bit more of a blacker background with better tone, leading me to keep using “smoother” to describe it.  The kit wasn’t hard to build, even though I’m sure I’d do better another time around.  100% worth it.


----------



## mxxl

Can anyone compare the crack with speedball to the little dot mkIII? I see so much praise for it and I’m wondering if it could be a solid upgrade down the line


----------



## TylersEclectic

Just picked up @raindownthunda extra base for the crack...damn if it isn’t beautiful! Great job bud! I’ll try and get non-camera phone pics soon! Ziricote wood if anyone was curious...


----------



## Wes S (Jan 18, 2020)

Darthpool said:


> Just picked up @raindownthunda extra base for the crack...damn if it isn’t beautiful! Great job bud! I’ll try and get non-camera phone pics soon! Ziricote wood if anyone was curious...


Wow!  Looks killer and goes very well with your desk!

Curious what is the driver tube?  Looks like it could be a Brimar ECC82 with a socket saver?


----------



## JTori

Darthpool said:


> Just picked up @raindownthunda extra base for the crack...damn if it isn’t beautiful! Great job bud! I’ll try and get non-camera phone pics soon! Ziricote wood if anyone was curious...



That's gorgeous!


----------



## TylersEclectic

Wes S said:


> Wow!  Looks killer and goes very well with your desk!
> 
> Curious what is the driver tube?  Looks like it could be a Brimar ECC82 with a socket saver?


That is a correct assessment on the driver


----------



## Wes S

Darthpool said:


> That is a correct assessment on the driver


Nice!  That was the first driver tube I feel in love with, in my BHC.  Never heard a Brimar I did not like.


----------



## JamieMcC

Darthpool said:


> Just picked up @raindownthunda extra base for the crack...damn if it isn’t beautiful! Great job bud! I’ll try and get non-camera phone pics soon! Ziricote wood if anyone was curious...



Looks fantastic any chance of some more details on the type of product/coating used to get such a nice finish?


----------



## TylersEclectic

JamieMcC said:


> Looks fantastic any chance of some more details on the type of product/coating used to get such a nice finish?


I didn't build it...lets ask the man himself  

@raindownthunda would you be so kind as to inform on this?


----------



## raindownthunda (Jan 21, 2020)

@JamieMcC I was inspired to build the ziricote base because of the ziricote ZMF Aeolus headphones I bought from @zach915m. I reached out to Zach to get help on the products and process to achieve a matching finish, so basically all of these tips are thanks to him! I'm planning to post a build write up on the base as I have a bunch of pictures of the process and final product. Right now I'm having too much fun tube rolling with my new Bottlehead Crack, so here's the quick rundown:

Sand up to 400 grit then apply Mohawk pre-catalyzed sanding sealer
Sand up to 1000 grit. For the high grit (500-4000) I used the abralon pads used for bowling balls that Zach recommended
Apply 5-7 coats of Mohawk pre-catalyzed semi-gloss clear lacquer, with light sanding at 500-1000 grit between coats - as needed to remove any bumps in the lacquer and definitely before the last coat goes on. The more you sand off the more coats you'll need to apply... Use a tack cloth to clean up dust between each coat, esp after sanding.
After the last coat dries, sand up to 4000 grit. I dry-sanded first and eventually wet sanded everything again, which turned out better.
Let the lacquer cure for a little over a week and then apply the Mohawk penthouse polish. I underestimated how much of a difference the polish makes! You can see after / before polish in the two pics below.
Let me know if you have any more questions! This was my first time doing this type of a wood finish so had a lot of questions going into it myself...

Here's the other base and Aeolus after applying the penthouse polish to both:





Fully assembled crack, BEFORE polishing the base, with all black furnishing & powder coated top plate & transformer:


----------



## JTori

raindownthunda said:


> @JamieMcC I was inspired to build the ziricote base because of the ziricote ZMF Aeolus headphones I bought from @zach915m. I reached out to Zach to get help on the products and process to achieve a matching finish, so basically all of these tips are thanks to him! I'm planning to post a build write up on the base as I have a bunch of pictures of the process and final product. Right now I'm having too much fun tube rolling with my new Bottlehead Crack, so here's the quick rundown:
> 
> Sand up to 400 grit then apply Mohawk pre-catalyzed sanding sealer
> Sand up to 1000 grit. For the high grit (500-4000) I used the abralon pads used for bowling balls that Zach recommended
> ...





raindownthunda said:


> @JamieMcC I was inspired to build the ziricote base because of the ziricote ZMF Aeolus headphones I bought from @zach915m. I reached out to Zach to get help on the products and process to achieve a matching finish, so basically all of these tips are thanks to him! I'm planning to post a build write up on the base as I have a bunch of pictures of the process and final product. Right now I'm having too much fun tube rolling with my new Bottlehead Crack, so here's the quick rundown:
> 
> Sand up to 400 grit then apply Mohawk pre-catalyzed sanding sealer
> Sand up to 1000 grit. For the high grit (500-4000) I used the abralon pads used for bowling balls that Zach recommended
> ...



Beautiful job!  Thank you for sharing the steps you went through to achieve such a striking finish.  I'll bet there are plenty of folks on the Bottlehead Forum who'd appreciate this info, if you share it there.

Best,

Joe.


----------



## cddc

raindownthunda said:


> @JamieMcC I was inspired to build the ziricote base because of the ziricote ZMF Aeolus headphones I bought from @zach915m. I reached out to Zach to get help on the products and process to achieve a matching finish, so basically all of these tips are thanks to him! I'm planning to post a build write up on the base as I have a bunch of pictures of the process and final product. Right now I'm having too much fun tube rolling with my new Bottlehead Crack, so here's the quick rundown:
> 
> Sand up to 400 grit then apply Mohawk pre-catalyzed sanding sealer
> Sand up to 1000 grit. For the high grit (500-4000) I used the abralon pads used for bowling balls that Zach recommended
> ...




Very beautiful finish!

Just curious to know: other than the chestnut color there is also some golden color on the top. Is it caused by the nature of wood itself (say, some areas of the board absorbed the Mohawk paint differently than the other) or you used 2 types of paints (chestnut & golden)?


----------



## raindownthunda (Jan 22, 2020)

cddc said:


> Just curious to know: other than the chestnut color there is also some golden color on the top. Is it caused by the nature of wood itself (say, some areas of the board absorbed the Mohawk paint differently than the other) or you used 2 types of paints (chestnut & golden)?



That's the wood itself. I didn't use any stains or paints, just clear coat. The grain is just really wild! I believe the light blonde part is the sapwood (younger part of the tree). Here's more examples of what it can look like: http://hobbithouseinc.com/personal/woodpics/zircote.htm

Here's what the planks looked like before I did anything with them:


----------



## cddc

raindownthunda said:


> That's the wood itself. I didn't use any stains or paints, just clear coat. The grain is just really wild! I believe the light blonde part is the sapwood (younger part of the tree). Here's more examples of what it can look like: http://hobbithouseinc.com/personal/woodpics/zircote.htm
> 
> Here's what the planks looked like before I did anything with them:




Ahhh...should have figured out that the chassis is made of non-stock boards, coz it's much higher than the stock chassis.

Excellent wood work!!!


----------



## Wes S

cddc said:


> Ahhh...should have figured out that the chassis is made of non-stock boards, coz it's much higher than the stock chassis.
> 
> Excellent wood work!!!


Looks like he left some room for some mods.  Which was clever.


----------



## NoName1 (Jan 22, 2020)

raindownthunda said:


> @JamieMcC I was inspired to build the ziricote base because of the ziricote ZMF Aeolus headphones I bought from @zach915m. I reached out to Zach to get help on the products and process to achieve a matching finish, so basically all of these tips are thanks to him! I'm planning to post a build write up on the base as I have a bunch of pictures of the process and final product. Right now I'm having too much fun tube rolling with my new Bottlehead Crack, so here's the quick rundown:
> 
> Sand up to 400 grit then apply Mohawk pre-catalyzed sanding sealer
> Sand up to 1000 grit. For the high grit (500-4000) I used the abralon pads used for bowling balls that Zach recommended
> ...


@zach915m Should consider making bottlehead bases to go with his headphones. I know I’d love a cocobolo base to match my ZMFs.


----------



## cddc

Wes S said:


> Looks like he left some room for some mods.  Which was clever.



For sure, enough room to hold these large caps and chokes


----------



## Wes S

NoName1 said:


> @zach915m Should consider making bottlehead bases to go with his headphones. I know I’d love a cocobolo base to match my ZMFs.


Sign me up for a Sapele, to match my Aeolus.


----------



## BobMonkhouse

It's my first post here in this thread... I've had my BH Crack for a month and love it!
Here it is in its full glory dressed up in my new just finished piano glossy frame:





It's going to sound better now because of the shiny frame, right?!...


----------



## Astral Abyss

BobMonkhouse said:


> It's my first post here in this thread... I've had my BH Crack for a month and love it!
> Here it is in its full glory dressed up in my new just finished piano glossy frame:
> 
> 
> ...


Very nice!  And shiny!  I love the logo you made for the front.


----------



## BobMonkhouse

Thank you! The logo's stainless steel brush finish, laser cut. The BH is really what my  HD6XX deserved.


----------



## bagwell359

BobMonkhouse said:


> It's my first post here in this thread... I've had my BH Crack for a month and love it!
> Here it is in its full glory dressed up in my new just finished piano glossy frame:
> 
> 
> ...



Hmmmm, might be a bit bright in the upper mids... The BHC can't play my HFM cans well, but my Senn 600 sounds remarkable on it.


----------



## cddc

BobMonkhouse said:


> It's my first post here in this thread... I've had my BH Crack for a month and love it!
> Here it is in its full glory dressed up in my new just finished piano glossy frame:
> 
> 
> ...





Very nice build!

Any difference in sound from the Ember?


----------



## BobMonkhouse (Feb 16, 2020)

It is different and as much as I like the Ember, the BHC adds not much width but layering and depth to the imaging of my HD6XX making it sound more holographic. Obviously, there's nothing objective in this statement talking about tube amps. It's all my subjective perception.

I like the relatively cheeper RCA 6AS7G output tubes and fine tune the sound by changing my few favorite mini driver tubes. I totally enjoy my music with this setup.

Again, there's nothing wrong with the Ember which I use with a few other headphones, but the BHC/HD6XX combo is very satisfying.


----------



## cddc

BHC and HD6XX is a match made in heaven 

Thanks for the impression on Ember, for sure Ember and BHC will sound different, one being hybrid and the other pure tube.


----------



## cddc

i luvmusic 2 said:


> I should have let her listened
> 
> It's a Sylvania and ???? 6CG7 can't read the name of it,Two listening area is enough for me The wife is taking the amp and the headphone Darn it.I should have let her listened to RAP music not her favourite instrumental.



Just curious: can 6CG7 be used in the 12AU7 socket? Do we need an adapter?  

Thanks.


----------



## DenverW

cddc said:


> Just curious: can 6CG7 be used in the 12AU7 socket? Do we need an adapter?
> 
> Thanks.




Yes, but you would either need an adapter, or, as Paul B states, " Just separate the jumper between pins 4 and 5, then run a wire from pin 9 to whicheven pin (4 or 5) has no wire running to it."  I'm lazy, so its adapter for me .


----------



## cddc

DenverW said:


> Yes, but you would either need an adapter, or, as Paul B states, " Just separate the jumper between pins 4 and 5, then run a wire from pin 9 to whicheven pin (4 or 5) has no wire running to it."  I'm lazy, so its adapter for me .




Cool, thanks a lot buddy!

I am pretty bad at soldering, so an adapter would be a much easier solution to me.


----------



## Tom-s

A new chapter in my own tube-rolling adventures -> Going from 3 to 4 tubes on my Crack . This with an 6080 -> dual A2293 adapter.
Did anyone notice the A2293 is only 0,95A -> more driver options  .



At this moment in time i've only changed the output tube. I'm not noticing much difference from my GEC 6080. 
I'll try to write a comparison soon. Comparing GEC 6080 with the GEC A2293's in detail. 
And maybe also compare single vs dual drivers, so a dual GEC tube Crack vs four GEC tube Crack.


----------



## JTori

Tom-s said:


> A new chapter in my own tube-rolling adventures -> Going from 3 to 4 tubes on my Crack . This with an 6080 -> dual A2293 adapter.
> Did anyone notice the A2293 is only 0,95A -> more driver options  .
> 
> 
> ...



Fascinating.  I've got a Crack and am interested in the benefits to this approach.

Best,

Joe.


----------



## cddc (Feb 23, 2020)

Tom-s said:


> A new chapter in my own tube-rolling adventures -> Going from 3 to 4 tubes on my Crack . This with an 6080 -> dual A2293 adapter.
> Did anyone notice the A2293 is only 0,95A -> more driver options  .
> 
> 
> ...



"Did anyone notice the A2293 is only 0,95A -> more driver options"

Interesting, you mean you've tried them in the 12AU7 socket?

I think 0.95A is close to 0.9A from ECC32. 

I normally do not like miniature tubes thou.


----------



## attmci

cddc said:


> "Did anyone notice the A2293 is only 0,95A -> more driver options"
> 
> Interesting, you mean you've tried them in the 12AU7 socket?
> 
> ...


I recall the 5998 or a pair of 6bl7 with adapter plus a 7316 are the best match for me. All the others are just waste of time and $$. But that was fun.


----------



## cddc

5998 indeed sounds very good.

I had some reading on 6BL7/6BX7 some time ago...it seems to me that some people with WA22 liked them at some point of time but later turned  back to 5998. Some Glenn folks still like 6 x 6BL7 in their systems, but that's way beyond Crack's capacity.


----------



## cddc

My current fav driver is TS round plates.


----------



## DenverW

For quite a while I also felt that 6sn7 types were my favorite in my crack/speedball.  i was mainly rolling the input tube, and tried everything from 12bh7a to e80cc to 2x7193/cv6.  

I was using a 5998 tube in the power 6AS7 socket.  Then I ended up finding a western electric 421a, and that changed everything.  The tube was lights out better than anything I had previously rolled, in either socket.  And oddly enough, it works best with 12au7.  So I went back to hunting for rare 12au7, if I could find them for an affordable price.  Some are priced so high as to make them ridiculous, like a genelex gold monarch or mullard 10m gold pin ($900?!?), but some rolls Royce 12au7 can be found on the cheap.  Siemens chrome plate, 1940s victor/rca black plate, and telefunken smooth plate (sellers don’t always recognize copper rod variants) are some to watch out for.  They sound heavenly.  

Anyway, don’t discount the 12au7.  There is a lot of junk out there that sounds harsh, but the amp was designed for this tube, and there are GREAT ones.


----------



## cddc

Great find on 12AU7s, I think it's all about synergy


----------



## BobMonkhouse

It's very true about the synergy. I prefer the 6SN7 in my Ember but 12AU7 tubes work better for me in my Crack.


----------



## DenverW

Funny enough, right after I posted that I ended up finding three end game Mullard 10M 12au7 gold pin for a non ridiculous price.  I’ll keep one and sell the other two.  Excited to hear them compared to the non gold pin.


----------



## attmci

DenverW said:


> Funny enough, right after I posted that I ended up finding three end game Mullard 10M 12au7 gold pin for a non ridiculous price.  I’ll keep one and sell the other two.  Excited to hear them compared to the non gold pin.


I will spend the money to upgrade the headphones, dac, and amp instead of expensive 12au7. The Bottleheads are good, but still....middle to low-end amps. I have successfully transfer a couple of believers to alternative amps. LOL

These are the best ones if you have $$$$$:

*- Gold Monarch B749 
 - Lorenz welded plate circle getter 12AU7 (even with sub-standard readings!) 
- Mullard 10M gold pins 12AU7 
- Telefunken ECC802S factory certified version 
- Cossor wrinkle glass long welded plate square getter double support 
- Siemens chrome plater double getter support ECC82 
 - Marconi toast plate square getter wrinkle glass B329 (Mullard made)*


----------



## DenverW

I have a few of those, one more now that the 10M gold are on the way.  I enjoy the collection aspect of things just as much as the sound.  The full list from above is:

Amperex long welded plate D-getter 12AU7 (pre-1955) 
Chinese stock 12AU7 
RCA 1940's black plate square getter 12AU7 
Valvo long plate D-getter ECC82 (pre-1955) 
Siemens chrome plater double getter support ECC82 
Marconi toast plate square getter wrinkle glass B329 (Mullard made) 
Telefunken ribbed plate wrinkle glass square getter ECC82 (the most early version) 
Telefunken smooth plate copper rod ECC82 
Telefunken ECC802S factory certified version 
Telefunken ECC802S generic version 
Brimar long black plate square getter 12AU7 
Brimar half box plate square getter CV4003 
Hivac shinny black long smooth side square getter CV491 
Gold Monarch B749 
Mullard 10M gold pins 12AU7 
Cossor wrinkle glass long welded plate square getter double support 
12AU7 (likely to be Mullard/Ediswan made) 
Lorenz welded plate circle getter 12AU7 (tested below standard!)


----------



## cddc

Holy Moly!  

You got way too many 12AU7s buddy 

You should also try some Amperex Bugle Boys, I found them very nice sounding.


----------



## DenverW

That’s not my list, I only have about 6 of those.  That list is just a reference for totl 12au7.


----------



## cddc

LOL...so it seems to be a long way to go


----------



## DenverW

That’s the fun of it!  If I were done collecting I’d be bored .


----------



## cddc

True...and with adapters more and more new tubes getting in the line


----------



## Tom-s

JTori said:


> Fascinating.  I've got a Crack and am interested in the benefits to this approach.



For me it's just something i've been wanting to try.  With GEC 6080's being very expensive and scarce. I want to compare this as an alternative (and on first impressions, it is).



cddc said:


> "Did anyone notice the A2293 is only 0,95A -> more driver options"
> 
> Interesting, you mean you've tried them in the 12AU7 socket?



No. Absolutely not. Don't plug them in the driver socket.
Crack uses a 3.5A power transformer. Normally 2.5A 6080 + 0.9A ECC32 is max. What i meant was, that with only 1.9A total for the power tube, there's 1.6A room for the driver tube. There's only a few extra options to try with Crack. 
For now. The only real world advantage of this lower power consumption is a cool running Crack on a hot day .


----------



## cddc (Feb 24, 2020)

Thanks a lot for the clarification, Tom! Obviously I made a mistake yesterday without checking the specs of A2293. I thought 0.95A is close to 0.9A ECC32, hence could be used to replace ECC32 in the 12AU7 socket.

I checked its specs today, A2293 is rated for 0.95A, so running a pair would be 1.9A, which is too high for the 12AU7 socket. However, if used in the power tube socket, 1.9A is sort of low compared to 2.5A 6080, is the dual A2293 going to be as powerful as 6080 when driving HD650/800?

I'm thinking of other possible candidates, but not sure if they can be used in Crack. Say, we use 0.3A 12AU7 as driver, then we will have 3.2A headroom for the power tubes, so has anyone tried 1.27A KT66 / 1.5A KT77 / 1.8A KT88 or 2.54A dual KT66 / 3.0A dual KT77?


----------



## m17xr2b (Feb 28, 2020)

cddc said:


> A2293 is rated for 0.95A, so running a pair would be 1.9A, which is too high for the 12AU7 socket


What?


cddc said:


> so has anyone tried 1.27A KT66 / 1.5A KT77 / 1.8A KT88 or 2.54A dual KT66 / 3.0A dual KT77?


What????

Don't take this the wrong way, you don't know what you're doing spec wise with tubes and it can be extremely dangerous, transformer meltdown flying sparks dangerous.


----------



## cddc

LOL....I'm asking potential candidates to try with Crack, not sure if they will fit in Crack though


----------



## cddc

You know the 6080/6AS7G family has limited members. If we can have some breakthrough into other family of tubes, it would be very encouraging.


----------



## DenverW

After spending a good amount time rolling all kinds of tubes, such as e80cc, 12bh7a, dual 7193, dual cv6, e1148, 6sn7, 6j5, 6f8g..

..I've come to the conclusion personally  (YMMV!) that the crack just seems to work best with the tubes it was designed for: 6as7/6080 type and 12au7 type.  I found a larger improvement in sound quality doing the bottlehead power cord than I did using 6sn7 tubes.

I've never really found an appealing power tube with adapter variant to try.


----------



## BobMonkhouse

Just wondering if there's another pair of headphones that can come close to the sound signature of the HD650 paired with the Crack!?


----------



## DenverW

Does price matter?  I've tried both an hd800S and SDR modded hd800 (my current headphone).  I would recommend both over the 650.  I think the 650 is the absolute best value on this amp price wise, because it can be found under $200 easily (6XX), but its not the BEST pairing.  I preferred my Beyerdynamic Amiron over the 650, both in sound and comfort.  Lots of high impedance headphones will match well with the amp.  Beyer T1, 1990, Amiron...ZMF offerings...HD800, all great.  The matchings can be somewhat tube dependent, for example if you match the T1 with a bright Westinghouse 12au7 it can really have sharp treble.

But for the price?  The 650 can't be beat, which is why its so often recommended for this amp.  If I misunderstood your question and by 'close' you mean sound signature instead of overall sound quality, I would say possibly a zmf such as an atticus, Aeolus, or eikon.  Hope this helps!


----------



## BobMonkhouse

That was exactly my question, you got it right, and I didn't think about the price point but rather improving on the HD650 experience with similar sound signature.

Actually, I love my HD6XX/Crack combo. I've listened to HD800 hooked up to SS type of amps but it's not for me, it's too lean and hot sounding from what I remember.

In the same price range, I'm curious about the ATH-R70X. It sounded quite neutral when I demoed it at a meet-up but don't know if it's going to be a good alternative with the Crack.


----------



## DenverW

I don't think it would be a major upgrade from the 650, especially if you like the sound signature on the 650.  I would say a big upgrade without losing somewhat of what you like in the 650 would be either a ZMF atticus or an HD800S.  The S is changed enough to lower the treble spike, much similar to the SDR modded 800.


----------



## BobMonkhouse

Good info here, thanks! Do you know where T1 stands against HD800 and HD800S?


----------



## DenverW

I found it a bit too bright for my tastes.  For Beyer my favorite sound signature was the amiron.


----------



## Wes S (Feb 29, 2020)

BobMonkhouse said:


> Just wondering if there's another pair of headphones that can come close to the sound signature of the HD650 paired with the Crack!?


The ZMF Aeolus, without a doubt.  I own the BHC Speedball, HD650, and Aeolus.  I can honestly say, that the Aeolus improves on every aspect of the HD 650 while maintaining a similar sound with the BHC, and it is a match made in heaven.


----------



## raindownthunda (Mar 10, 2020)

Wes S said:


> The ZMF Aeolus, without a doubt.  I own the BHC Speedball, HD650, and Aeolus.  I can honestly say, that the Aeolus improves on every aspect of the HD 650 while maintaining a similar sound with the BHC, and it is a match made in heaven.


Couldn't agree more!


----------



## larcenasb

Anyone here have experience rolling different bypass caps for the Crack's last power supply cap? With this extra time at home, I spent hours switching out and listening with the two bypass caps I have: Jantzen Superior Z-cap 0.68uF 800V & Audyn Tri-Reference 0.68uF 600V ($15 & $25, respectively...neither grossly expensive).

This obviously isn't ideal because it's not a blind test, and there's a good chunk of time between listening with each bypass cap. Also, I am a highly skeptical person and am constantly questioning things to make sure I'm not fooling myself. Yet, every time I switch to the Audyn Tri-Reference, I am confident there is a noticeable tone and quality shift for the better. Specifically, the Audyn allows for a larger and deeper soundscape, precise placement of instruments within that soundscape, and a delicately handled treble with no loss of tantalizing bite. So, I soak in the sonic pleasure...then my skepticism cuts in again. I proceed to unplug everything, take my amp downstairs to the garage, and switch the cap back to the Jantzen again. And again, the sound is comparatively closed in, the distinct placement of instruments not so apparent, and treble a bit screechy...or so I think.

At this point, I feel like I'm going nuts... On one hand, I feel nourished and enthralled by my music in a substantial way with the Audyn, but, on the other hand, I know that there's nothing easier than fooling oneself. Another reason to think it's placebo is that I adore the marketing of the Audyn caps. Audyn's description of their True Copper Cap on Hificollective's website states that there is "no contamination by strange mixture of various metals and fairy like oils (LOL)," and the Tri-Reference is very similar with its copper-foil construction. Conveniently, the Jantzen is "made from polypropylene film metalized with aluminum and zinc particles (from partsconnexion)," i.e. a stange mixture of various metals haha. So those descriptions could be swaying my thoughts. But, Jantzen does go so far as to describe what their cap's sound is like, saying it has "good detailing and soundstaging with natural tone reproduction," but that's what I hear with the Audyn, not the Jantzen. But that is likely my bias towards Audyn, and trusting their marketing more to begin with. Buttttt maybe marketing and truth are not always mutually exclusive! AHHHHHHHHHHfjodyasknfd456%$^#5njkfbnas###!!

If anyone has done similar tests or has other opinions, I'd love to read about them as I gather more info about this mystique of judging musical reproduction.

(For reference, my Bottlehead Crack specs can be found on my profile page: About > Audio-Related Tweaks.)

I hope all of you and your loved ones are staying safe and doing okay amid our physical social distancing. Cheers


----------



## Tom-s

larcenasb said:


> Anyone here have experience rolling different bypass caps for the Crack's last power supply cap?



IMHO, while the gains may vary. Rolling a bypass fancy type cap just for the sake of experimentation, to experience how the PS influences the sound, is a good thing to try.
Especially with cheap / Russian caps, go ahead.



larcenasb said:


> At this point, I feel like I'm going nuts...



To be honest, i feel you're not the only one here . But in a good way.

It's the good kind off Crack to escape this weird reality for a while. Last weekend I had a perfect high made possible by the great adapter dealer @Deyan .


----------



## larcenasb

Tom-s said:


> It's the good kind off Crack to escape this weird reality for a while. Last weekend I had a perfect high made possible by the great adapter dealer @Deyan .


Thanks for the reply! And whoa! Please tell us what tubes and adapters those are! And how would you compare the sound to a 6AS7G+6SN7GT combo!? Thanks!


----------



## Tom-s (Mar 23, 2020)

The following should be read with this in mind. I have enough tubes to not have a single clue anymore on how every single one sounds.

The driver tubes are Sylvania 76's, that's some sort of grand father version of the 12AU7 and 6SN7/7N7 that became 6J5 and went into a single envelope ->> 6SN7 was born.
In general these have a big band, cathedral kind of sound to them. It's like a S3X, you are placed somewhat further away from the podium in a bigger hall. This makes them sound very very good, similar to when you are used to 6J5's, that also have this kind of effect on presentation. I don't roll 6SN7's that often, so don't know exactly how they compare. The National Union, Sylvania and RCA's 76's i own all have a different flavor but share the "big band" sound that makes you want to turn up the volume. Before i was using an adapter tower, this @Deyan adapter looks better imo.

The output tubes are some variation on the A2293's (see previous pages), another "half 6080" type of tube, Russian 6C19P, there's actually a few OTL tube amps based on these. It's technically not much better than 6080 on datasheet. And I couldn't find many comparisons with these, luckily Deyan was kind enough to build me an adapter for this purpose.
In general i feel this tube does sound very good. It's not the best on every level, but very very capable overall. But i've started to notice these need time to warm up, like a Bendix 6080 that sounds better after 30 mins or so. I'll do a, single triode per envelope that fits half a 6080, comparison one day.


----------



## bagwell359 (Apr 10, 2020)

Got a kit, have stared at it for two weeks while I read up on all the design concepts, suggested mods, tossed in my own experience building kits through the years.

I decided to build it in versions:

1. stock - but go with different attenuator, and locking headphone jack
2. add speedball
3. add caps & other mods

so I'm using insulated clips to I don't have to solder and re-solder over and over.  When I'm done I'll hard solder it.

Also, I dislike the way the amp looks with the RCA's and power cord sticking up like rooster feathers.  So they are going in from the side, and I'm hard wiring the RCA's, using a well insulated cable (3-5') (using cable ties as strain relief for both).  I'm bypassing the input plug and on/off as well.  Don't worry, I'll pretest the "right way" and "my way" to be sure I haven't done something idiotic.

I'm putting a pair of 270 ohm chokes on top over the RCA and power in holes.  If there is notable hum in that position I'll try others or metal sheets to block them from the PS.  It seems that there could be some hum due to the wiring, so twisting, re-routing, insulation, and magnets may be employed.

Finding any of best power tubes very tough to aquire.  The input tube is easier.  I'd say tubes are 3x more expensive then around Y2K when I had the last of my tube stuff.  Haven't bought anything yet.

Will buy speedball and Cree Shottky's & board this week.  Have a pair of 1.0 uf Clarity Caps from another project I didn't use - so they will be my first bypass attempt.  I like the Obliggatto 100uf, esp with the Supreme oil bypass.  The 2 220's for the PS might not get updated (but will get bypassed) but the 3rd one is.  There is a Mundorf Mlytic meant to be mounted on a board that looks good for that (not film).

I'm changing resistors in the signal path to Mills, and that pair of 5 watt coffins is gone, and I'll mount a spherical heat sink on the Mills.  Probably heat sink the Cree Schottky as well.  Actually only the single 1 watt to dissipate voltage is likely to be the only one in the kit I use in the long run.  I want a dead on match for the headphone and vol pot.  Haven;t tested the kit resistors yet, but doubt they are that tight.


----------



## Bullpride

Wes S said:


> The ZMF Aeolus, without a doubt.  I own the BHC Speedball, HD650, and Aeolus.  I can honestly say, that the Aeolus improves on every aspect of the HD 650 while maintaining a similar sound with the BHC, and it is a match made in heaven.




I have a BHC Speedball on the way (ordered this morning).  I also have the Atticus, which is what started me down the tube route.  Are you running the stock tubes with your BHC?  If not, where should I start with the best pairing for The ZMF cans?

I am also already working on an upgrade from the crack, but its at least a few months away. I am hoping the crack shipping soonish so I have some time with it.


----------



## Wes S

Bullpride said:


> I have a BHC Speedball on the way (ordered this morning).  I also have the Atticus, which is what started me down the tube route.  Are you running the stock tubes with your BHC?  If not, where should I start with the best pairing for The ZMF cans?
> 
> I am also already working on an upgrade from the crack, but its at least a few months away. I am hoping the crack shipping soonish so I have some time with it.


Nice!  The BHC sounds amazing with my Aeolus and I can only imagine the Atticus would sound great too.  I am currently running some of the best NOS tubes ever made, and could not be happier.  My current tube combo is, the Bendix 6080WB Graphite Slotted Plate for power tube, and the Valvo ECC82 Long Plate Foil D Getter from Hamburg Germany 63' as the driver tube.  These tubes are expensive, but can't be beat in my setup, with my heaphones and taste.  I would look for any Bendix 6080WB Graphite plates for power tube, and my other 2 favorite driver tubes are the 7316 Long Plate Foil D Getter, and Sylvania 5814a Triple Mica Square Getter with Grey Plates.

Happy tube hunting!


----------



## m17xr2b (Apr 14, 2020)

I'm thinking this is the last upgrade to my Crack, a dual PSU setup, a shared CLC then a split LC.

In addition, SIC input bias and gyrator for the input.  Now the amp has matured into a different beast and while I'm having even more upgrade ideas this has to be the end.




I did run for a while clarity cap TCs for the PSU, uber sound but impractical and now part of a different amp.


----------



## Toad_of_Toad_Hall (Apr 21, 2020)

.


----------



## Bullpride

Toad_of_Toad_Hall said:


> New build totally devoid of electrolytics.




Is that a custom base?  Taller than the stock?  Any suggestions for building one myself?  I have one on its way, and want to build a taller base with African Padauk to match my Headphones. I can PM you if you prefer.


----------



## JamieMcC

Toad_of_Toad_Hall said:


> New build totally devoid of electrolytics.



Nice work you must have had a blast building it.


----------



## Toad_of_Toad_Hall (Apr 21, 2020)

.


----------



## Toad_of_Toad_Hall (Apr 21, 2020)

.


----------



## Tom-s

*When paying tax makes beautiful. *

Below is an example from the Fivre factory in Milan, Italy (a company that produce US tubes in Europe under RCA license). 
It's a pair of type 76 tubes, used as drivers in Crack (with an @Deyan adapter). *Click on image for full size.
The stickers are from the ministry of finance, they were proof tax was paid on the tube (tax was based in weight and type of tube if i'm correct). 
I was very lucky to find these. I found the first tube long ago in Belgium (grabbed it untested, based on looks), just recently I found another in the Netherlands (and both are NOS). The search was diffucult as the top mica support construction is rare. Other Fivre 76's were found with normal RCA type top mica construction, but I couldn't find another reference of this construction type anywhere on the internet. And as fate would have it, both came with the exact same tax sticker on them dating 9.9.42 (and matching code above it). 
It may have to do with the fact that the Italians didn't get along with the rest of the world those years, that these look different. The construction may have changed due to lack of supplies from the RCA company USA (or other war-time related shortages). I've only seen 6C5's from that era with the same construction top "springs?" https://www.ebay.com/itm/254507568343 .

The sound is typical 76. These are  detailed, with a sort of "bigband" enveloping type of sound to them. The bass is less pronounced compared to other tube types, still they sound full, very enjoyable. These mate well with Bendix 6080's or Tung Sol 5998's, or as seen in pictures with GEC A2293's. Are they much different from other RCAs type build 76's, no not really. Do not pay crazy money for this kind of tubes (above hyperlink). A 20$ RCA pair 76's sounds close to the same to me.


----------



## D P C

Been looking at these myself just lately and thinking is a kit for me or just buy one done? Thats the question


----------



## D P C

Also do they do a balanced input version? And anyone in the UK got one? If so what was it like to import it


----------



## Toad_of_Toad_Hall (Apr 21, 2020)

.


----------



## Toad_of_Toad_Hall (Apr 21, 2020)

.


----------



## Toad_of_Toad_Hall (Sep 22, 2021)

.


----------



## profanum429

D P C said:


> Been looking at these myself just lately and thinking is a kit for me or just buy one done? Thats the question



Get the kit! It's a good time putting it together and you get to learn some about how it works  I really enjoyed doing mine.


----------



## bagwell359

larcenasb said:


> Anyone here have experience rolling different bypass caps for the Crack's last power supply cap? With this extra time at home, I spent hours switching out and listening with the two bypass caps I have: Jantzen Superior Z-cap 0.68uF 800V & Audyn Tri-Reference 0.68uF 600V ($15 & $25, respectively...neither grossly expensive).
> 
> This obviously isn't ideal because it's not a blind test, and there's a good chunk of time between listening with each bypass cap. Also, I am a highly skeptical person and am constantly questioning things to make sure I'm not fooling myself. Yet, every time I switch to the Audyn Tri-Reference, I am confident there is a noticeable tone and quality shift for the better. Specifically, the Audyn allows for a larger and deeper soundscape, precise placement of instruments within that soundscape, and a delicately handled treble with no loss of tantalizing bite. So, I soak in the sonic pleasure...then my skepticism cuts in again. I proceed to unplug everything, take my amp downstairs to the garage, and switch the cap back to the Jantzen again. And again, the sound is comparatively closed in, the distinct placement of instruments not so apparent, and treble a bit screechy...or so I think.
> 
> ...



I think I've looked at every Crack build on the net.  This is one of my favs.  Clean, organized, and chock full of great pieces.


----------



## bagwell359

D P C said:


> Been looking at these myself just lately and thinking is a kit for me or just buy one done? Thats the question



Haven't built one of these, but I have built about 20 other audio kits.  Very satisfying, and if you add even or two wrinkles of your own, than it's unique.  Plus I'm cheap, I figure if it costs $X dollars for someone to do it, I can spend that on better pieces in the build - but that's me.

There are a few people that specialize in these, I'm sure they are very good.


----------



## larcenasb

bagwell359 said:


> I think I've looked at every Crack build on the net.  This is one of my favs.  Clean, organized, and chock full of great pieces.


Hi bagwell359,

Thanks so much, your comment means a lot.  I see you have a BH Crack too...have you done any upgrades? If so, what did you choose?


----------



## bagwell359

larcenasb said:


> Hi bagwell359,
> 
> Thanks so much, your comment means a lot.  I see you have a BH Crack too...have you done any upgrades? If so, what did you choose?



Collecting all pieces first before I start.  Hope to get going within 2 weeks, it's about 85% aftermarket parts.  

I'm chasing a rare NOS tube today.  I can't find any really good film 100uf caps either, so I may start w/ the stock, and change later.  I actually think it's people building the crack now because a lot of the popular aftermarket film 100's are out of stock and just went out over the past 3 weeks.  Good news is from prior projects I have a lot of the pieces in home already.


----------



## GreenNeedle (Apr 26, 2020)

Finally read through this thread.  That's a lot of pages lol.  Just to open I was initially looking for a cheap option to let me listen to my HD580 and Sextetts from my laptop on rare occasions, but somehow ended up much higher up the chain and am here fully sold on the BH Crack.  Of course being here means I want to utilise this equipment more than just here and there from my laptop.

With this in mind I want to be able to use this amp with my CD player as well.

I am currently researching affordable (yes subjective) DACs to put in between the amp and source and so far the Grace on the Drop site has favourable reviews with the Crack and the price is what I would suggest is affordable.  I am looking at £100 for the DAC as being my ballpark and while the Grace is $80 which would make it about £65 if looking at exchange rates, this is the UK and in buying terms you can basically ignore the exchange rate and say £1 = $1 when buying this sort of thing.  Anyway I digress.  The Grace looks fine, has good reviews and is bang on budget.  I can go from laptop to it via USB and voila, the original intention (PC to HD580 audio perfection) is solved.

However, now adding the CD player into the equation I hit a problem (or maybe not a problem) as it is a USB input DAC only.  No optical input.  My CD player is a Denon DCD-500AE.  (IMO) it sounds incredibly good fed into my Stereo receiver and nearly as good plugged into my Yamaha AV.

My question(s) is/are as follows:
1 - Is the DAC onboard this CD player (Burr Brown PCM1791) good enough to plug direct into the Crack or would I be better getting an external DAC that I can plug both the laptop AND CD player into?
2 - IF we went the external DAC route with the Denon and found an alternative with Optical input, would the "pure direct" option on the CD player bypass the onboard DAC and thus put an untouched digital signal to the external DAC for it to do the conversion work?
3 - With the above in mind where the source and crack are already decided, what would you do?  Go for the grace and just plug the CD directly into the Crack when wanted?  (Use a source selector?)  Buy a different DAC that both can plug into?

I am open to buying used so a DAC up to £150/$150 including shipping and customs is the budget.

Am I misunderstanding the CD player to DAC part?

EDIT:  One more question.  I don't really want to get into the debate about cables however I can understand that a poundland USB cable might have some effect on the source signal to DAC so would I need to buy something a little better?  My other interconnects are Van Damme OFC with Neutrik RCAs.  I made them myself.


----------



## larcenasb (Apr 26, 2020)

Hi GreenNeedle!

First off, congrats on deciding to build a Crack! I've built three since 2010 and can sincerely say, it's a staple in my audio life. Plus, I use them with Sextetts and it achieves my favorite type of sound I've expereienced: smooth and present with plenty of lush body and a bit of lifelike bite. Here's my answers to your questions:

1) Here is a 2008(!) post of different DACs' specs (from audioholics):

"Flagship Burr-Brown DACs: PCM1792 (THD 0.0004%, SNR 129dB, Crosstalk -124dB).

Second Burr-Brown DACs: PCM1796 (THD 0.0005%, SNR 120dB, Crosstalk -119dB).

Flagship Analog Devices DACs: AD1955 (THD 0.0006%, SNR 120dB, Crosstalk -125dB).

Flagship Cirrus Logic DACs: CS4398 (THD 0.0007%, SNR 120dB).

Flagship Wolfson Microelectronics DACs: WM8741 (THD 0.001%, SNR 128dB).

Third Burr-Brown DACs: PCM1791 (THD 0.001%, SNR 113dB, Crosstalk -110dB)."

So, the PCM1791 is considered Burr-Brown's third-best back in 2008. While I suspect music through it will be enjoyable, we're 12 years moved on with advanced models for amazing prices.
2) The Pure Direct function is only to forgo any digital signal processing, such as bass/treble controls--it doesn't mean to bypass the onboard DAC. Simply using an external DAC will be what bypasses the onboard DAC--because, with the signal leaving your CD player through optical, it's still in digital form and hasn't undergone analog conversion yet. So, to send out an "untouched digital signal to the external DAC," simply use an external DAC in combination with the Pure Direct function.
3) Personally, I wouldn't want to have to unplug/replug different sources into my amp. I would buy a Schiit Modi, or something similar. That way, for $99, I'll have a source selector and will improve the sound of my CD player. If I bought the $80 Grace, my CD player will still have the ancient DAC and I'd have to tolerate unplugging/replugging things. I wouldn't buy a source selector and Grace because that would be very nearly the same price as the Modi, but the CD player won't have the improved sound. I say get the Schiit Modi, or look for second-hand DACs that have both optical and USB inputs.

Answer two I think should have cleared up the CD player to DAC part.

As for the USB cable question, the best I can do without debating is to simply state that I'm not one who thinks it would improve the sound in a double-blind test. Glad to hear you built Van Damme cables with Neutrik plugs, I love DIY too of course. Cheers and enjoy your Bottlehead build!

P.S. Just to share my opinion... For me, the most important mods for the Crack, to make it its best, are the Valab 23-step attenuator, Speedball upgrade, and a 6SN7-to-12AU7 6.3V adapter with American (or British ) NOS tubes. Once I build my 4th Crack, those three will be the first upgrades I do.


----------



## GreenNeedle (Apr 26, 2020)

larcenasb said:


> Hi GreenNeedle!
> 
> First off, congrats on deciding to build a Crack! I've built three since 2010 and can sincerely say, it's a staple in my audio life. Plus, I use them with Sextetts and it achieves my favorite type of sound I've expereienced: smooth and present with plenty of lush body and a bit of lifelike bite. Here's my answers to your questions:
> 
> ...



Thanks for your very detailed answers.  Can I ask you to clear up a couple of further questions that have come up with another few hours of research (Lockdown is getting to me. lol) into this as well as clearing up some other bits and maybe you can also give an opinion on my understanding of this research.  This is from multiple other sites.  Bear with me.  I'm not trying to debate what you have said, merely ask for an opinion.  It may well be an "ears/taste vs specs" debate on my part vs reality that may well mean that the specs prove something is better or worse.

I do know what DACs do, just that I am kind of an analog guy and not really gone into depth before on how they sound different to each other.

r.e. the DAC.  I understand what you are saying r.e. old tech but then there is the whole "TDA1541 lovers" aspect of an ancient DAC plus there is the old vinyl vs digital debate which counters (rightly or wrongly) that suggestion.  I do prefer the sound of vinyl (maybe placebo) and I also prefer to put my music through my mid 70s Trio (Kenwood) Stereo Receiver than I do through my late noughties Yamaha RX-v361 AVR.  In terms of vinyl this is a necessity because the AV doesn't have a phono stage but if I put the Denon CD player via analog into the Trio then it sounds much better (to me) than putting it into the AV whether using analog or Digital (Optical or Coaxial.)

I also have a Pioneer DV696-AV player which is a bit of an all rounder that  plays DVDs or CDs but it also plays SACD.  From what I can gather this has a PCM1742KEG/2K  DAC in it? I only have 1 SACD so that is a moot point really but I originally bought the Denon because I didn't like the sound of music from the Pioneer through either the Stereo receiver or the AVR.  The Denon solved this.  The one SACD I have came in a deluxe edition I have and thus along with the "standard" CD version of the same album.  The standard version through the Denon sounds as good if not better than the SACD version from the Pioneer through either receiver.  The Standard version sounds pants through the pioneer.

I am assuming from what you say r.e. external DACs is that if I am plugging my sources via digital into the Yamaha that it is the Yamaha DACs that are being used and not the source equipments?  And thus the same would happen if plugging digital into a dedicated DAC?  In theory at the moment the Yamaha is doing what an external DAC would be doing?

So I'm not dismissing at all that tech has moved on, nor that the DACs in both of these units are outdated, just that to my ears the Denon sounds very good through my setup which is limited by budget but way above most people's setups, i.e. soundbars or DVD players with little surrounds etc.  I'm a min wage earner so I get what I can and keep hold of it unless it stops working 

I guess the above is all very subjective in terms of listening but a whitewash on paper looking at specs.

I already have a source selector which is actually a speaker selector used in reverse so that I could hook up both receivers to the same front speakers rather than connecting / disconnecting speaker wires.

In terms of the Modi.  There is so much info out there about equivalent DACS and I can see there is a lot of love for the Schiit setup.  Also I don;t know how much Modi has improved from v1 to v3.  There are a lot of conflicting opinions out there and so I kind of ended up at Topping D30 vs the Grace SDAC.  The Topping has the optical inputs so would remove the need for a source selector.  It also has independent power rather than being powered by my laptop. Any other options? DAC-01A?

The Modi3 is hard to get at the mo.  SchiitUK dealer has no date on when they will get more, US means heavy customs on top, Used prices are high too at the mo because of availablility.  Ther is a used Modi3 on ebayUK at the moment.  1 day left and is already at £99 ($122) It will probably end up in the £150 region!!!!  D30 I can get for £80 delivered. Grace about the same.

As for the BH Crack.  I am just looking at buying the stock + speedball.  Tube rolling is not really my thing in terms of trying loads out.  As you can tell I research like mad (autism. lol) so will spend hours finding out what within budget I can do and sticking with that option once bought, other than replacing when a tube wears out.  I did read an article somewhere that weighed up value for money on tubes but for some reason I can't find it which is a pity because it detailed a $30 tube that gave value for money.  We'll see.   A week ago I was looking for an all in one amp/DAC for £100 max. lol.  Finances aren't infinte though and while I am still working who knows what is going to happen in terms of consumer confidence in the next year or 2 so can't empty my limited bank funds into this obsession.  I'll probably just use the stock tubes for a while after I build it.


----------



## larcenasb

GreenNeedle said:


> Thanks for your very detailed answers.  Can I ask you to clear up a couple of further questions that have come up with another few hours of research...



1) Yes, there are of course exceptions. I myself prefer my older AudioQuest DragonFly v1.0 to both the v1.5 and Red. And I generally prefer vinyl over digital copies I've heard (though there are again exceptions, such as the DTS track on the Nirvana Unplugged DVD). Most people, in my experience, can tell the difference in tone and lack of compression of vinyl (vs digital) pretty reliably--I think placebo is more likely with USB cables ;P. The difference between your vintage Kenwood and modern Yammie receivers I think has more to do with the quality of vintage receivers (less-compromised designs, serious power transformers, and quality analog stages) vs modern AV receivers (generally, low-effort designs and low-grade components) than it has to do with what source is being plugged into it. If a signal is decent enough, like with your ancient DAC, then the drastic quality difference of the receivers will have more of a say in how good the system sounds. Same goes with the better Denon CD player (vs the Pio)--the unit itself is of such a quality that the inferior disc format doesn't matter as much anymore. Though this is a classic science mishap of having two independent variables. There should only be one independent variable (disc format) while everything else remains the same in order to see the real differences between the formats.

Other comparisons mentioned are also unfair. For example, vinyl may be older, but we have to remember that the trend for digital formats, in the beginning, was mostly convenience over quality. Vinyl is analog whereas digital formats started with pretty heavy compression. Digital has offered uncompressed options as we've moved along but it's not as if vinyl to CD to mp3 to SACD to Blu-ray audio was intended as being a linear increase in sound quality. This graph looks more like a valley. Whereas DACs _are_ intended to be a linear increase in sound quality (in terms of improving THD, SNR, and crosstalk). The exceptions are not so much to do with what era a particular piece is from, but the implementation, engineering, and circuit design being so good that it may lead that component to having a lovers' club or cult following. For me, the DragonFly 1.0 is one such exception because even though the Red clearly has less distortion, the sound is presented in a way that doesn't cater to the sounds I prefer. The Red, in my system, is clearer but more closed in, prone to glare, and constricted.

My point is, for similar money to the Grace, you can get an optical/USB DAC that does more for the money (source selection, CD player sound upgrade). Now, if your CD player's DAC was one of those pieces that had a cult following--that was designed in such a way that the sound presentation was a standout and outweighed its inferior specs--then I'd make the case to get the Grace and a source selector. But, as it stands, you're already planning on spending $80 for a DAC, and it makes more sense to me to utilize a modern DAC for both your sources for around the same amount of money.

2) What you say here is correct... "I am assuming from what you say r.e. external DACs is that if I am plugging my sources via digital into the Yamaha that it is the Yamaha DACs that are being used and not the source equipments?" The source won't convert from digital to analog then back to digital when it leaves optically. The optical output bypasses the source DAC entirely. And yep, the Yammie is doing what the external DAC would be doing.

3) I totally understand wanting to be frugal in this hobby; I try my best to as well. My point still stands though that you're already spending around $100 for a DAC, and in my opinion, spending a little more money for a multi-input DAC likely will give you more satisfaction, given your setup. But if you already have a source selector that can work for you, and you do enjoy the Denon's DAC... then you just need to decide if $20 more is worth it or not for the simplicity of one DAC and to see if the Denon's sound quality can improve. Previously, I didn't know you had a source selector... Your decision rests on spending or not spending $20.

4) The Topping D30 has a nice following too. There's also the SMSL M100 for $80. Obviously, more research will yield a mind-numbing number of results. I think you can save time and trust the many positive reviews for the D30, Modi, or M100.

5) Yeah, tube rolling can be daunting, but I went down that path...and I think researching a bit and trying out just a couple 6SN7 tubes is entirely worthwhile. To me, the sound is satisfyingly bigger, reaches deeper into bass frequencies, and sounds more true-to-life. Just know it's an option, and perhaps in the future you'll be interested in exploring it.

Decisions, decisions! Don't go too mad, but I hope you'll be mad about your system and enjoy it for years to come. Take care.


----------



## GreenNeedle (Apr 27, 2020)

larcenasb said:


> 1) Yes, there are of course exceptions. I myself prefer my older AudioQuest DragonFly v1.0 to both the v1.5 and Red. And I generally prefer vinyl over digital copies I've heard (though there are again exceptions, such as the DTS track on the Nirvana Unplugged DVD). Most people, in my experience, can tell the difference in tone and lack of compression of vinyl (vs digital) pretty reliably--I think placebo is more likely with USB cables ;P. The difference between your vintage Kenwood and modern Yammie receivers I think has more to do with the quality of vintage receivers (less-compromised designs, serious power transformers, and quality analog stages) vs modern AV receivers (generally, low-effort designs and low-grade components) than it has to do with what source is being plugged into it. If a signal is decent enough, like with your ancient DAC, then the drastic quality difference of the receivers will have more of a say in how good the system sounds. Same goes with the better Denon CD player (vs the Pio)--the unit itself is of such a quality that the inferior disc format doesn't matter as much anymore. Though this is a classic science mishap of having two independent variables. There should only be one independent variable (disc format) while everything else remains the same in order to see the real differences between the formats.
> 
> Other comparisons mentioned are also unfair. For example, vinyl may be older, but we have to remember that the trend for digital formats, in the beginning, was mostly convenience over quality. Vinyl is analog whereas digital formats started with pretty heavy compression. Digital has offered uncompressed options as we've moved along but it's not as if vinyl to CD to mp3 to SACD to Blu-ray audio was intended as being a linear increase in sound quality. This graph looks more like a valley. Whereas DACs _are_ intended to be a linear increase in sound quality (in terms of improving THD, SNR, and crosstalk). The exceptions are not so much to do with what era a particular piece is from, but the implementation, engineering, and circuit design being so good that it may lead that component to having a lovers' club or cult following. For me, the DragonFly 1.0 is one such exception because even though the Red clearly has less distortion, the sound is presented in a way that doesn't cater to the sounds I prefer. The Red, in my system, is clearer but more closed in, prone to glare, and constricted.
> 
> ...



Again thanks for the detailed answer and humouring my questioning nature.

1 and 2 are put to bed there.  Just for interest.  The Yamaha uses the AK4588VQ DAC.  No idea which of these 3 DACs (PCM1791, AK4588, PCM1742) "should" sound better but as stated.  The 1791 is the one I prefer of the 3.  The Denon sounds better analog into the Yamaha (thus using the Denon DAC) than it does through digital (using the Yamaha DAC)...to my ears anyway.  The Pioneer is the opposite as it sounds better digital (using the Yamaha DAC) than analog (using the Pioneer DAC.) 

I appreciate what you say that this may not solely be down to the DAC itself and the engineering of each unit has a part to play in how that DAC sounds.  I also appreciate that compared to many people on this or other forums all of these pieces of equipment are relatively budget/entry level.

So of the 3 my taste / hearing ranks them 1791 > AK4588 > PCM1742.

3.  I need to be very frugal, not just in this hobby.  I am a min wage earner with a wife and 3 kids in a country that is very expensive to live in. lol.  Add on top that the current economic situation may well have effects for the next few years.  If I spend money on things, they have to be keepers or hold their resale value.  My nature is quite investigative anyway so I would probably still research like mad even if money were no object.

On the subject of the Denon.  Would it be worth looking for a DAC that had analog inputs as well so I can decide whether the Denon sounds better with its onboard vs the external DAC?  I assume from the above if I exit the Denon via analog into a DAC then the DAC does nothing other than pass the signal through to the amp it is connected to?

4)  I will look into the M100.  The D30 does look favourite at the moment.

5) I get what you;re saying here.  barring some bad luck I will have years to buy a tube here and there.  A slower "try tubes out" than most but still.  Can you give a basic description what difference replacing the big tube with another small tube makes?  I know this depends on what tube is used but in general.

And for 5)  No worries there.  I have always been proud of my setup.  At each stage of progression it has improved.   Within budget each upgrade has been very satisfactory and while the Yammie wouldn't get too many people in this hobby excited, it does its job very well.  For films, TV, youtube etc it sounds exceptional and is very versatile.  It plays music very well for people who aren't looking for perfection.  After all we live in an age where people seem happy to listen to compressed music through the tinpot speaker of their phone, through a cheap bass overloaded bluetooth speaker etc.  I think most people nod to humour me when I'm detailing the musical failings/limitations of parts of my equipment.  I can't afford true audiophile setup from source to end but I do want to try and get as close as I can within a tight budget.  For me the music is the key part.  I'm not particularly bothered if everything else doesn't sound that good as long as the music does.  For the rest of the household they wouldn't really notice the difference.

I splurge on audio equipment, then am dormant for a while.  I suppose spread out I would average £300 to £400 a year on equipment but that includes audio, multimedia and audio.  I'm looking here to get a separate headphone setup to keep for the next decade with minimal spend on top once it's done.  Then I can enjoy that setup while the wife and/or kids are enjoying some other aspect of the "family" entertainment setup.

I am thinking of buying the crack kit this week.  No idea about lead time or when it will arrive.  Should be fun when it does though.


----------



## larcenasb

GreenNeedle said:


> Again thanks for the detailed answer and humouring my questioning nature.
> 
> 1 and 2 are put to bed there.
> 
> ...



3) Yeah, as I mentioned earlier, I've been listening with a Bottlehead Crack since 2010 and am supremely happy with my setup. Plus, you also have K240 Sextetts that I imagine you enjoy...well, the combo of Sextett+Crack is again my favorite I've encountered so far. When I "upgraded" to the Beyer DT 1990, I still preferred the Sextett...the Beyer sounded harsh and the mids were nowhere near as present or lifelike, they were scooped out unforgivably (after hearing the Sextett, many owners often won't compromise on mids). As for the resale value, stock Cracks tend to sell for around $600 on eBay. I was pm'd here on head-fi by someone offering $1000 for my build! That made me really proud. My advice to you is to really take your time with the build--when people see the guts of the amp, it should inspire confidence and, hopefully, awe.

A DAC with analog inputs isn't common. You can do research here to try and find some models, but I've only seen in it very expensive receiver-sized type DACs which prioritize features/options. Emotiva had one but it was still around $350. I think the best way to test your Denon CD player's DAC would be to simply connect it to your amp directly via RCAs (Denon -> RCAs -> Bottlehead Crack), listen to music critically; then add your new DAC to the chain (Denon -> optical cable -> DAC -> RCAs -> Bottlehead Crack), listen to the same music critically. Then go back and forth comparing. And yes, if you did get a DAC that has analog inputs, the Denon's signal would bypass the new DAC circuit (since there is no digital signal for it to convert), and it would just be sent out analog the same as how it entered...unless it's some strange model that I'm not aware of.

4) The Topping seems like a smart buy. It's all-metal with sturdy toggle switches and has fantastic reviews.

5) I'm not sure I understand what you mean when you said "replacing the big tube with another small tube." What I meant was the opposite. The stock driver/input tube is a small tube (12AU7) and some listeners opt to buy a 6SN7-to-12AU7 (6.3V) adapter to use the bigger (6SN7) tube. In general, a 6SN7 will make the presentation sound bigger, bass will reach deeper, voices will have more body, and there will be an overall sense of lushness to the sound. Lots of people though, including Doc of Bottlehead, prefer a good NOS 12AU7 (Mullard, Telefunken, Brimar, Amperex, et al.). So, it's all just options as you search for the presentation you like. Supposedly, many audio engineers in the 50s were upset about the advent of the 12AU7, saying it was clearly inferior to the octal predecessor, but was cheaper to make. To really simplify, some say the 12AU7 has a cleaner more solid-state like sound in general, and the 6SN7 has more character and bloom giving it the quintessential tube sound. It's nice the Crack allows for sooo many options to finetune your sound.

And yeah, same here, my setup is the culmination of a lot of research and small, informed steps. I like finding great values most of all and being happy with what I do have, as the quote in my sig alludes to.

6) Well, I think the Bottlehead Crack and AKG K240 Sextetts will likely offer you plenty of satisfaction for a long, long time. Lol, it's nice that I have those two pieces as part of my main setup, so it should inspire a bit of confidence in you that it's worth it.

7) Yeah, have fun with the build! But if I may elaborate on what I meant about really taking your time with the build... I don't know how much soldering experience you have, but I'll say just in case: Try to make the wiring decent at the very least, without overlong wires or messy routing (that will really help with resale value). And remember to make a good mechanical connection before soldering. I've seen so many builds where people put solder on a wire lead, heat up the joint, then move the wire to the joint... It's best to not rely on the solder to make the connection, it should just be bolstering an already-made connection. I like to make a nice curved hook with the wire lead, secure it on the intended joint and either use helping hands to hold the other end of the wire to pull it taut, or even use pliers to pinch the hook and make it tightly fit around the wire/socket tab...then solder. The solder shouldn't be a bridge, it should be a straitjacket. Hope this helps! Take care!


----------



## Tom-s

Another day, another tube to try in Crack. Today from the type 37 collection. This is an 1931 (december) pair Sylvania 37 that I picked up recently. I've always wanted to try an old mesh plate tube in Crack. But since it's for 6.3V indirectly heated only, the options are very very limited. There are these old globe's, that are very rare and have a huge potential to hummmmm. 
And that last part, is just what they do (continues loud hummmmm). They are not microphonic, they just hum away. This may indicate a grounding issue i've never noticed with any other tube of be due to the fact that the amp is AC heated. This is most likely as the hum does not change with volume and these were designed in a mostly DC era, to be used in cars using 6V heater from the car battery. Unfortunately, the hum makes them unsuitable for my Crack. 
Sound: With the volume up (because of the low volume hum), there's beautifully clear dynamic music. Tight bass with good authority, very precise defined high's, good soundstage, nice natural tonality overall. It's very unfortunate that no modern manufacturer is making a mesh plate indirectly heated driver tube (without hum issues).

For now, i'll investigate the hum further, to hopefully be able to use these in the future. A DC heated driver socket (another Crack) is sort of a last resort.


----------



## GreenNeedle (Apr 28, 2020)

larcenasb said:


> 3) Yeah, as I mentioned earlier, I've been listening with a Bottlehead Crack since 2010 and am supremely happy with my setup. Plus, you also have K240 Sextetts that I imagine you enjoy...well, the combo of Sextett+Crack is again my favorite I've encountered so far. When I "upgraded" to the Beyer DT 1990, I still preferred the Sextett...the Beyer sounded harsh and the mids were nowhere near as present or lifelike, they were scooped out unforgivably (after hearing the Sextett, many owners often won't compromise on mids). As for the resale value, stock Cracks tend to sell for around $600 on eBay. I was pm'd here on head-fi by someone offering $1000 for my build! That made me really proud. My advice to you is to really take your time with the build--when people see the guts of the amp, it should inspire confidence and, hopefully, awe.
> 
> A DAC with analog inputs isn't common. You can do research here to try and find some models, but I've only seen in it very expensive receiver-sized type DACs which prioritize features/options. Emotiva had one but it was still around $350. I think the best way to test your Denon CD player's DAC would be to simply connect it to your amp directly via RCAs (Denon -> RCAs -> Bottlehead Crack), listen to music critically; then add your new DAC to the chain (Denon -> optical cable -> DAC -> RCAs -> Bottlehead Crack), listen to the same music critically. Then go back and forth comparing. And yes, if you did get a DAC that has analog inputs, the Denon's signal would bypass the new DAC circuit (since there is no digital signal for it to convert), and it would just be sent out analog the same as how it entered...unless it's some strange model that I'm not aware of.
> 
> ...



_*reply to 3*_*:* The Sextetts were a suggestion out of the blue from Monsterzero. Never heard of them before. I managed to get an LP and like it a lot. Reading on I bought an MP but preferred the LP. A year or so on with new genuine AKG pads and I'm not so sure anymore. The MP is sounding really nice. I also bought the Senn 580s from reading on here and they are now complete with genuine new pads, 650 cable and 600 grilles. They sound amazing too. To be honest I tend to prefer the 580s to the Sextetts for most music however they can't compete on some music. It's always the Sextetts for ACDC - Back in black. No competition there. The Sextetts sound perfect for music that is closer to a "live" recording. The BH Crack just seems from the reviews an amp which will be perfect for both the Sextett and HD580. I wouldn't have any of these were it not for this forum so a collective thank you to all. 

_*reply to 5:*_  My bad.  I was assuming 6 = small and 12 =  big. lol.  I get you here.  Will have to see where we go over time on this.  I can;t afford to buy a selection of tubes trying out things but over time, a tube here and there.  They hold their value I suppose even at the lower end.

_*reply to 7:*_  I'm no electrician nor have much knowledge of electronics but I do have internet access which is great for learning and being able to try things yourself that in my/our younger days would have needed a lot of reading books or taking courses to achieve.  I can solder though.  Research and trying led me to building this luminaire in 2012.  This was actually an aesthetically improved version.  I had made 2 more before this in boxes but I am a very vain person and aesthetics are key (Bottlehead crack looking great is important as how it sounds.  I have also replaced lamps in several old stereo receivers as well as replacing headphone jacks etc, so I do have a fair amount of practice with soldering.  This is why the bottlehead crack appeals to me because (if all the reviews and write ups are true) it doesn't really need knowledge of electronics.  Simply an ability to solder and follow instructions is the selling point in my eyes.  The below is very simple; 2 Led drivers. 1 driving 2 outer rows (12 x 3W LEDs.)  1 driving the centre row (6 x 3W LEDs.)  Using stars so easy to solder them.  Wires hidden under the heatsinks so you can only see them from below.  I did this from using other people's knowledge and adapting what can be done to what I wanted to do.  Someone with electronics knowledge would have been able to do it much better.  I did it by using 2 plugs.  I'm very much a "can do" type of person.  I like to see if I can do it before I say I can't :



To be quite honest here, for all my tall of frugalness I do have thoughts in my mind to have a go at a S.E.X. for my speaker setup if this goes well.  I am quite lucky in that I don't have any credit, and a few months "cover money" in the bank.  

I would still use the Trio receiver, just to connect everything up and then use the "tape rec" as a line out to the S.E.X.  The Trio looks beautiful lit up and I have invested time and money refinishing / veneering that. lol.

That is some way off though.  Let's see how the crack goes first.  Many thanks for your help though.  I'll order the crack+speedball tonight.  IT was Lugnegaard's finish that really appealed to me.  Dark outer, polished plate, rounded edges.  Not decided whether I will try and veneer it or just dye the existing wood yet.  I have time to think on that.  Veneering is hard on rounded edges.


----------



## GreenNeedle

Sorry another question for anyone who knows the answer.  I have tried searching the internet but it seems there used to be a 240V version of this kit that people in Europe and UK ordered.  

There is just one Crack kit on the site that I can see.  Is there some clever wiring that allows it to be used at 240V in the UK?  or is the kit they sell at the moment only to be used on US 120V wall outlets?  Like those SS amps that have a switch on the back that you slide as applicable to your wall outlet supply?


----------



## Tom-s

GreenNeedle said:


> There is just one Crack kit on the site that I can see.  Is there some clever wiring that allows it to be used at 240V in the UK?


Yes. It comes with a universal powersupply that can be wired for both 120 and 240v.


----------



## GreenNeedle

Tom-s said:


> Yes. It comes with a universal powersupply that can be wired for both 120 and 240v.



Thank you, ordering the Crack now.

Oh and after researching the S.E.X. that is a no goer.  My speakers are 88db.


----------



## PsilocybinCube

Need some help with a noise coming from the Crack w/Speedball.  I bought one second-hand a few weeks ago and can't get a faint sound (only playing on the right channel) to go away.  It sounds like a lightbulb warming and then maintaining the 'warming' sound throughout the time it is on.  I _think _it's the power tube...currently RCA 6AS7G in that slot.

I've tried a few different things:

Swapped 12AU7 tubes (no change)
Tried different power cords (no change)
Purchased a power conditioner (very, very slight improvement)
Swapped RCA cables (no change)
Moved closer or further from other devices (no change)

I don't think it's interference.  I do think it's the power tube...but I'm wondering if anyone can think of other things to try.  I have zero DIY experience with amps, but I'm fairly handy and want to learn.  I just don't even have any clue where to start when I look at the underside of the board and all the connections.

The amp also has Mudorf caps and ALPS potentionmeter.  I don't even know what that means...so I'd love to learn.

Other than the slight hum - which fades into the background when listening to music at reasonable levels - the Crack sounds great.  

I'm coming from a DX7Pro, so this change to SE and tubes is definitely a big change.


----------



## Wes S (Apr 29, 2020)

PsilocybinCube said:


> Need some help with a noise coming from the Crack w/Speedball.  I bought one second-hand a few weeks ago and can't get a faint sound (only playing on the right channel) to go away.  It sounds like a lightbulb warming and then maintaining the 'warming' sound throughout the time it is on.  I _think _it's the power tube...currently RCA 6AS7G in that slot.
> 
> I've tried a few different things:
> 
> ...


I would try a different power tube, and this would be the first thing I would try.  I have had some noise before, and it has always been the power tube or driver tube.  A tube swap with a better tube has always done the trick.


----------



## larcenasb

Wes S said:


> I would try a different power tube, and this would be the first thing I would try.  I have had some noise before, and it has always been the power tube or driver tube.  A tube swap with a better tube has always done the trick.


Same here. I've had a few noisy 6AS7G tubes... but they are pretty cheap and I love their sound over the 6080, so a few bad eggs in the basket are more than tolerable for me.


----------



## PsilocybinCube

As a new person to tubes, I'm a little lost on where to order them.  I bought some of the Soviet Winged 'C' tubes...but then realized they probably won't come forever because they are being shipped by Putin's personal assistant direct from the Kremlin.

For purposes of an inexpensive tube (mostly to narrow down if the power tube is indeed the issue), what would you recommend buying that could get to me quick?  (I'm in US, btw)


----------



## DenverW

A rca 6as7g is cheap and plentiful.  A tung sol 6080 or 6as7g....I can’t remember which tube I sent to you with the crack.


----------



## PsilocybinCube

It's the RCA 6as7g which it seems a lot of people say have some microphonics (I think that's the term) that cause some noise.


----------



## GreenNeedle (Apr 29, 2020)

Hello, me again.  I'm considering making my own base rather than trying to veneer rounded edges.  Can anyone give me the thickness of the wood?  I see the chassis plate is 10" x 6" and the planks about 3.5" high, so what I am after is the actual thickness of the wood for the base below the rebate/rabbit.

I know I said dark but I am going to use Santos Rosewood to match what I did with veneer on my Trio turntable and Stereo Receiver:


----------



## PsilocybinCube

PsilocybinCube said:


> It's the RCA 6as7g which it seems a lot of people say have some microphonics (I think that's the term) that cause some noise.



I swapped out the power tube and troubleshooted other buzzing (all electronic interference from devices, mostly a printer) and now it is dead silent and sounds great!

Computer interference was a bit of a pain and is still occurring to a degree, mostly when running very intensive programs.  Moving the amp and DAC away from the my PC ameliorated that issue, but it's hurt the feng shui of my desk!

Looking forward to continuing to use the amp.  I swapped the power tube for a super cheap SINO tube from Tube Depot.  I have the Soviet Winged C tubes on order and look forward to trying them once they come in.  At some point, I'll have to give some different 12au7 tubes a try, too.


----------



## Wes S

Hey fellow Crack fans!  For the past year, I have been in a pretty intense love affair with the 12AU7, and having a blast.  However, as the tube rolling addiction goes, I decided to see if the grass was greener on the other side, and got some adapters to roll some of my top tier 6SN7's.  Well it turns out, this time it actually was greener on the other side.  This is my current tube roll and one I will not be changing any time soon.  The Tung Sol 6SN7GT VT231 BGRP, is the real deal.  Everything about this tube is perfect, when paired with a Bendix 6080WB, my Atticus and Gumby.  The detail, depth, impact, and realism are all the best I have heard from my BHC.  The 6SN7 is a killer tube and worth giving a try, no doubt.


----------



## PsilocybinCube

Wes S said:


> Hey fellow Crack fans!  For the past year, I have been in a pretty intense love affair with the 12AU7, and having a blast.  However, as the tube rolling addiction goes, I decided to see if the grass was greener on the other side, and got some adapters to roll some of my top tier 6SN7's.  Well it turns out, this time it actually was greener on the other side.  This is my current tube roll and one I will not be changing any time soon.  The Tung Sol 6SN7GT VT231 BGRP, is the real deal.  Everything about this tube is perfect, when paired with a Bendix 6080WB, my Atticus and Gumby.  The detail, depth, impact, and realism are all the best I have heard from my BHC.  The 6SN7 is a killer tube and worth giving a try, no doubt.


Which adapter do you recommend?  I've been considering this myself.


----------



## Wes S (May 7, 2020)

PsilocybinCube said:


> Which adapter do you recommend?  I've been considering this myself.


I recommend 2 different ones.  The first is from Garage1217, and the second is from forum member @Deyan.

Here is the link for the Garage 1217 - http://garage1217.com/garage1217_diy_tube_headphone_amplifiers_012.htm

Contact @Deyan, by PM, and he is really great to work with.  He can pretty much make what ever you want, and he has a great reputation on this forum.

The Garage 1217 is not as pretty, and I need to put a cover over that white part.  @Deyan's look much better, by the way.


----------



## Wes S (May 8, 2020)

I put a cover over the white Garage 1217 6SN7 adapter, and now it is looking good.  I highly recommend giving the 6SN7 tube w/adapter a try,  if you have the Speedball.  The sound for me went to another level, and is blowing my mind!    Every part of the sound got better, as in more realistic/lifelike sounding.


----------



## raindownthunda

Wes S said:


> I put a cover over the white Garage 1217 6SN7 adapter, and now it is looking good.  I highly recommend giving the 6SN7 tube w/adapter a try,  if you have the Speedball.  The sound for me went to another level, and is blowing my mind!    Every part of the sound got better, as in more realistic/lifelike sounding.


Looking good!! Do you think the sound is better than your best 12au7 tubes?


----------



## DenverW

Finished my crack build!  All black.  Completely stock right now, but with S Tier tubes from my previous bottlehead amps (Western Electric 421A and 1954 Amperex long welded plate D getter).  My previous crack, which I did not build, was upgraded with speedball, blue alps, and mundorf caps.  Unfortunately, its been long enough that I cant identify specific differences.


----------



## Wes S (May 8, 2020)

raindownthunda said:


> Looking good!! Do you think the sound is better than your best 12au7 tubes?


Thanks!  I like my top tier 6SN7 more than my top tier 12au7, but I would not necessarily say they are better.  I could see people liking it either way depending on synergies and preferences.  All I know, is 12au7's won't be going back in my BHC.


----------



## Wes S

DenverW said:


> Finished my crack build!  All black.  Completely stock right now, but with S Tier tubes from my previous bottlehead amps (Western Electric 421A and 1954 Amperex long welded plate D getter).  My previous crack, which I did not build, was upgraded with speedball, blue alps, and mundorf caps.  Unfortunately, its been long enough that I cant identify specific differences.


Nice tubes and Crack!  Those are some top tier tubes, no doubt.  It's nice to see another tube roller, that uses top tier tubes!  They really take the amp to another level.


----------



## larcenasb

It's been harrowing and mad this Crack obsession! I keep thinking this will be the last upgrade,--one more, one more, one more--but now I think it really will be...because I plan to order the Crackatwoa soon. 

For my last mod, I decided to set up my last PS cap for bypass cap rolling. I set up the leads to allow alligator clips to easily attach. There is also adhesive Velcro on the caps to make sure each bypass stays put.

A special thanks to Doc and PB for informing me how to safely handle charged caps--they advised I make a bleed resistor tool (5W 10K ohm) to discharge the PS cap before handling.


I plan to buy just a couple more bypass caps to roll and experiment with (cheaper ones). But here is my grail piece: the Audyn True Copper Cap (As Audyn says, "No contamination by strange mixture of various metals and fairylike oils." haha). I've dreamt about it for sooooo long. It's about $40, and while that's sane compared to V-Caps or Jupiters, I still always try to be frugal. It's been torturous holding out, but finally this is the one comparatively lavish exception for me! For a while, I settled with the Audyn Tri-Reference, which is a high-quality piece already, but I'm happy to now close the book on my upgrade addiction. This thing is weighty and feels serious!


*Audyn True Copper Impressions*: It's too early to_ fully_ assess, but right from the get-go, the treble is noticeably more controlled and refined, and the focus of the imaging more precise. The scale of the presentation is bigger/wider. If you've read my thoughts on the Crack before, you know I value bite during crescendos to rile me up. Versus the Tri-Reference, the True Copper takes a tiny bit of the bite away from tracks that used to give me serious goosebumps, but the clarity and refinement are eye-openingly improved. So, I'm in a place where I thought I would never give up ANY PART of the bite, but am now really being seduced by what's on offer. I am honestly disappointed that the True Copper didn't retain the bite AND introduce the refinements... but I'm becoming more aware that the bite seems like it's a result of the treble flying off the handle a bit; not being fully controlled. It's kind of like a minecart lifting a bit off the track during a high-speed turn...not fully controlled but makes the experience exhilarating. Whereas the True Copper stays locked on the tracks. It's nice to know I can easily swap the caps now depending on my mood or curiosity. As I get more bypasses and do more listening tests, I'll post my impressions. Cheers and stay safe everyone.


----------



## PsilocybinCube

DenverW said:


> Finished my crack build!  All black.  Completely stock right now, but with S Tier tubes from my previous bottlehead amps (Western Electric 421A and 1954 Amperex long welded plate D getter).  My previous crack, which I did not build, was upgraded with speedball, blue alps, and mundorf caps.  Unfortunately, its been long enough that I cant identify specific differences.


I like it!  Looks like mine...except for the plate.

BTW, I finally got my 'Soviet Winged C' power tubes and they sound great.  The RCA had that issue which got replaced by a cheap SINO tube from China.  That tube made the amp silent and I was happy with the sound...but the NOS Winged C tubes sound waaaay better.

Now for getting an adapter to try the 6SN7 tubes where the 12au7 is...


----------



## DenverW

Speedball ordered.  The upgrade bug has set in, so I’ll probably do speedball, then the potentiometer, then caps.


----------



## Wes S

I just can't get enough of this tube combo, and I am really digging the look too!

Bendix 6080WB and Tung Sol 6SN7GT BGRP all lit up, and sounding insanely good with my ZMF Atticus.


----------



## DenverW

I bet those tubes pair together so well!  Its always good to hear tube combos; you can make a great tube average with a bad one, or make a good tube great with a good pairing!  I have a victor/rca 1940's 12au7 that is very clear and pairs very well with warm power tubes.


----------



## Bullpride

My build is sitting in the basement, waiting on a replacement multimeter that wasn't reading Ohms.  It should be in the mailbox today.  Hoping I can get some final tests done tonight and pics posted tomorrow!!


----------



## Wes S

DenverW said:


> I bet those tubes pair together so well!  Its always good to hear tube combos; you can make a great tube average with a bad one, or make a good tube great with a good pairing!  I have a victor/rca 1940's 12au7 that is very clear and pairs very well with warm power tubes.


Totally agree, and I have had my BHC for over a year now, and I am still having a blast tube rolling and finding those magical combos.


----------



## DenverW

Let’s talk about capacitor rolling?  Who has replaced the stock 100uf or others?  Anyone running just a bypass or a new film cap with a bypass?


----------



## Toad_of_Toad_Hall (Sep 22, 2021)

.


----------



## chrisdrop

Wes S said:


> I recommend 2 different ones.  The first is from Garage1217, and the second is from forum member @Deyan.
> 
> Here is the link for the Garage 1217 - http://garage1217.com/garage1217_diy_tube_headphone_amplifiers_012.htm
> 
> ...


FYI- one more recommendation for @Deyan. He is great to work with.


----------



## Tom-s (May 13, 2020)

I'm also a very happy @Deyan adapter user! I now have about 10 of them. And all are perfect for my rolling adventures!

His 37 / 76 adapter is getting some fine use. I found a General Electric 37 pair in the collection today and opened the boxes for the first time since packing (Date code 43-L0, if anyone knows what date this is?? ).

Lovely open detailed sound with the most refined highs, more "hi-fi" compared to other 37/76 tubes. I'm a big fan of these more "cheap" alternative tubes.

Here's a picture, fresh from the box, before removing 60-80 years of the dust from them. I like these old style GE boxes. Prefer them over the "modern" grey/orange ones.


----------



## DenverW

Toad_of_Toad_Hall said:


> ClarityCap TC 110uF output caps - Will bypass with 1uF Audyn True Copper Max (when they eventually turn up from the UK). No electrolytics in the power supply - Just more ClarityCap TCs. Very happy.



Did you replace the ps caps with 110uf as well?  Any trouble with the fit?


----------



## JamieMcC

Toad_of_Toad_Hall said:


> ClarityCap TC 110uF output caps - Will bypass with 1uF Audyn True Copper Max (when they eventually turn up from the UK). No electrolytics in the power supply - Just more ClarityCap TCs. Very happy.



Hi I seem to have to have a vague recollection you have used the clarity caps in a crack before (5 or 6 years ago maybe) but my memory is not what it used to be?


----------



## Toad_of_Toad_Hall (Sep 22, 2021)

.


----------



## DenverW

Sounds impressive!  And complicated.  For now I'll put in the blue velvet pot, wait for speedball to arrive, put that in, and then pop in the kzk output caps.

Does anyone have a suggestion on mounting the caps without having to drill holes in the faceplate?  I will if I have to, but I'd prefer other options.  The caps are 59mm L and 63mm D.   Big, but not as big as mundorfs.


----------



## larcenasb

Spent the last several days comparing bypass caps for the last power supply film cap in the Crack (Audyn Q4 68uF 400V, same as output caps), and here are my impressions:

No bypass cap: Very smooth sound, but not very engaging. Still pleasant and enjoyable. 

Audyn Tri-Reference 0.68uF 600V: Not as smooth, little details are rendered sharply, vocals take a significant step forward. There's plenty of attack and engagement when listening, makes your eyes pop open. Compared to no bypass, the difference is obvious...this is like adding a supercharger.

Audyn True Copper 0.68uF 630V: The supercharger impression is diminished, vocals take a modest step back, attack and engagement are lessened. Instruments separate further apart, the soundscape width expands, little details are sharp yet the overall sound is smoother than the Tri-Reference. The sound seems very refined and controlled, treble is never screechy. Interestingly, I have to turn the volume up a couple clicks to match the output of the amp with the Tri-Reference.

Current thoughts: When I first heard the True Copper, I was entranced with its refinement and control. I thought this is a clear objective upgrade in sound quality--and it is--even though it wasn't as engaging as the Tri-Reference. After several days of testing each, I found that I kept smiling more when going back to the Tri-Reference. I appreciate the True Copper's high-class, controlled sound...but I adore the Tri-Reference's on-the-edge lust for life--its need to spill its heart out every time. I analyze the music more with the True Copper, and I experience goosebumps from the music more with the Tri-Reference. In the end, it is a quality that's really important to me.


----------



## larcenasb

DenverW said:


> Does anyone have a suggestion on mounting the caps without having to drill holes in the faceplate?



I recommend you drill and use zip tie mounts with a small bolt and nut. I've used just adhesive zip tie mounts with the Crack before, and after a few months the adhesive didn't hold and one of the caps dropped. The heat of the top plate and the weight of bigger caps require a more secure mounting method.


----------



## Bullpride

So............ Everything put together, plug the RCAs into the Pass of my Drop Liquid Carbon + Grace SDAC.  Not getting any sound.  Anyone else using the the LCX x/Grace as just a DAC? Passing the analog signal to their Bottlehead (or another amp). USB in from my computer.  I hope I am not misunderstanding how the link in the chain should work.











https://imgur.com/gallery/3KnaWrz


----------



## DenverW

I wish I could say it’s because the volume knob is all the way down.  

Did it pass all of the resistance and voltage checks?  If so, do you have another dac to test it with, or a different amp to test the pass through function?  That would help narrow down if you’re looking at a pass through issue or an issue with the crack.  Pass through shouldn’t be a problem.  Once you have the check numbers, post them with the issue on the bottlehead forums and doc and Paul will help you as well.

Thats a nice looking amp!


----------



## Bullpride

DenverW said:


> I wish I could say it’s because the volume knob is all the way down.
> 
> Did it pass all of the resistance and voltage checks?  If so, do you have another dac to test it with, or a different amp to test the pass through function?  That would help narrow down if you’re looking at a pass through issue or an issue with the crack.  Pass through shouldn’t be a problem.  Once you have the check numbers, post them with the issue on the bottlehead forums and doc and Paul will help you as well.
> 
> Thats a nice looking amp!




Ha yeah I wish, too.  I did turn the volume up.

All resistance and voltage test passed. 

Unfortunately the LCX is the only DAC/Amp I currently have.


----------



## DenverW

I’m not familiar with the lcx amp, but what I’d do is review the manual to make sure I’m not missing some kind of setting with the pass through, then I’d post my voltages on the Bottlehead forum in the crack section.  Theyre super helpful and can identify if the issue is with the crack.  

it looks like the tubes are glowing fine, but if you have any other tubes I would swap them.  Also check the solder joints on your headphone jack.


----------



## PsilocybinCube

DenverW said:


> I’m not familiar with the lcx amp, but what I’d do is review the manual to make sure I’m not missing some kind of setting with the pass through, then I’d post my voltages on the Bottlehead forum in the crack section.  Theyre super helpful and can identify if the issue is with the crack.
> 
> it looks like the tubes are glowing fine, but if you have any other tubes I would swap them.  Also check the solder joints on your headphone jack.


It's likely your amp might need to be set to line out mode or DAC-only mode.  You should verify that the sound is passing through the RCAs.


----------



## Bullpride

So the Grace SDAC on the Liquid Carbon does have an RCA Pass, but that only works with the SE RCA input.

There is a 3.5mm Line Out which is part of the DAC itself.  3.5 to dual RCA connected to the Crack and we are in business. 

Some other pics of the finished build:
https://imgur.com/gallery/3KnaWrz

Some pics of the build along the way:
https://imgur.com/a/z5odUR0


----------



## bagwell359

Here is what my BHC is going to look like.  Before you spit out your wheaties:

1. I'm adapting a cage for the backside to keep anyone for getting a ground shock off the filters, if it looks bad or doesn't work they'll go inside.

2. I know the amp isn't balanced, but all my cables terminate in a balanced not SE manner.  It doesn't hurt that the cable locks in more surely than the stock piece.  I will add an SE plug later, hung underneath the chassis.  

3. I dislike the unruly ostrich like power line and RCA ins.  So I'm going under.  Direct short run for both, I may notch the case once I've installed them.  Seems weird to have the RCA ins then run across the length of the amp.  I don't like the fuse/AC in combo either, they are gone, separate AC3 fuse holder going in.  Also adding X1 Y2 safety caps at input.

4. Yes, using E80CC.  Have the resistors for the change needed for speedball

5.  Yes, cutting down the shaft of the volume pot about 1/2" so knob sit better.

Why all the fuss?  Well between 1972 and 1983 I built 14 kits and they all were by the book.  Then for years I built subwoofer cabinets and changed tweeters and x-overs, but no kits.  Pretty sure this will be my last one, so why not go over the top?


----------



## Bullpride

bagwell359 said:


> Here is what my BHC is going to look like.  Before you spit out your wheaties:
> 
> 1. I'm adapting a cage for the backside to keep anyone for getting a ground shock off the filters, if it looks bad or doesn't work they'll go inside.
> 
> ...


Interesting looking build for sure.

What XLR Jack did you use? I've considering putting one mounted through the front of the base (So I have both options).


----------



## Wes S

bagwell359 said:


> Here is what my BHC is going to look like.  Before you spit out your wheaties:
> 
> 1. I'm adapting a cage for the backside to keep anyone for getting a ground shock off the filters, if it looks bad or doesn't work they'll go inside.
> 
> ...


That looks amazing!


----------



## bagwell359

Bullpride said:


> Interesting looking build for sure.
> 
> What XLR Jack did you use? I've considering putting one mounted through the front of the base (So I have both options).



Performance Audio - they had the gold pins (Neutrik NC4FD-LX-B Female 4-Pin XLR Connector (Black/Gold) for $7.14 and the shipping was $1.20 !!!  First I ever bumped into them, but based on that, they seem good, and that's the lowest I've paid for anything to be shipped in decades.


----------



## bagwell359

Wes S said:


> That looks amazing!



Thanks, I wanted it to be different, but nice looking and technically sound too.


----------



## Bullpride

bagwell359 said:


> Performance Audio - they had the gold pins (Neutrik NC4FD-LX-B Female 4-Pin XLR Connector (Black/Gold) for $7.14 and the shipping was $1.20 !!!  First I ever bumped into them, but based on that, they seem good, and that's the lowest I've paid for anything to be shipped in decades.


I will check them out.  Did you have to do a lot of surgery to get it to fit where the standard jack goes?


----------



## bagwell359 (May 16, 2020)

Bullpride said:


> I will check them out.  Did you have to do a lot of surgery to get it to fit where the standard jack goes?



Yes, its got a bigger footprint than the SE Neutrix, which needs a bit of drilling.   So after drilling a guide hole, I increased to my biggest bit and was maybe .15" short, so I had to grab it firmly and keep running the drill around the inside "circle", that can take a few minutes.  when most of it fits, there is little 1/3" x 1/8" nub that has to be taken out on the release cable silver push thing.  I have some excellent cutters, but they didn't seem right, so some more drilling in that "nub" space".  It's easier than it sounds, but its not easy, just tedious.

My largest bit is bigger than what you typically get at HD when you buy a box of 20 bits.  It's a 1/2".  5/8" is probably closer, don't do like me - measure first!


----------



## PsilocybinCube

Has anyone tried the Beyerdynamic T1 gen 2 with the Crack?  I am using HD 650s right now and like them, but it would be nice to have something a bit more detailed.
I have the BHC w/speedball if that makes a difference.  
I use the Crack for a mixture of listening to music throughout the day while working and then occassional PC gaming at night or weekends.  
I have heard and seen a lot of mixed reviews of the T1, but amp pairing never seems to be right.  In the reviews where someone used a tube amp, the reviews seem to be better.
Anyone with thoughts on this?


----------



## DenverW

PsilocybinCube said:


> Has anyone tried the Beyerdynamic T1 gen 2 with the Crack?  I am using HD 650s right now and like them, but it would be nice to have something a bit more detailed.
> I have the BHC w/speedball if that makes a difference.
> I use the Crack for a mixture of listening to music throughout the day while working and then occassional PC gaming at night or weekends.
> I have heard and seen a lot of mixed reviews of the T1, but amp pairing never seems to be right.  In the reviews where someone used a tube amp, the reviews seem to be better.
> Anyone with thoughts on this?



They pair well with the crack.  The sound signature is brighter than the 650, especially the t1.1  version.  If your budget allows, I would look for a used hd800.  They cost more than the t1, but the increase in detail is worth it.


----------



## PsilocybinCube

DenverW said:


> They pair well with the crack.  The sound signature is brighter than the 650, especially the t1.1  version.  If your budget allows, I would look for a used hd800.  They cost more than the t1, but the increase in detail is worth it.


I'm very interested in the HD800.  The high price and the fact that people seem much more taken by the HD 800s (add when more to the cost) has me looking for the poor man's HD800.
Do you think the original HD800 (not the S) is a worthwhile purchase?


----------



## DenverW

PsilocybinCube said:


> I'm very interested in the HD800.  The high price and the fact that people seem much more taken by the HD 800s (add when more to the cost) has me looking for the poor man's HD800.
> Do you think the original HD800 (not the S) is a worthwhile purchase?



For the crack, absolutely.  The SDR mod for the hd800 puts it about where the hd800S is as far as eliminating the treble peak.  With the mod the hd800 keeps its great resolution.  I have a ZMF auteur, a focal clear, and an hd800 SDR, and I'm having a really hard time trying to figure out which to keep and which to let go.  It pairs SOOO well with the crack.


----------



## bagwell359

PsilocybinCube said:


> I'm very interested in the HD800.  The high price and the fact that people seem much more taken by the HD 800s (add when more to the cost) has me looking for the poor man's HD800.
> Do you think the original HD800 (not the S) is a worthwhile purchase?



Check out the well thought out mods for the 800.  In addition the 800 has a cleaner bass with less THD, which the Crack will take care of.  Only issue is age and shape to deal with and of course the mods.


----------



## bagwell359

Here are a few more pics, I was careless and broke something so another 3-4 day delay.  Labor Day is about when the thing will be done.

Used half cherry and half oak to get the finish.

How's that for a piece of marble?  Heh...


----------



## cddc

bagwell359 said:


> Here are a few more pics, I was careless and broke something so another 3-4 day delay.  Labor Day is about when the thing will be done.
> 
> Used half cherry and half oak to get the finish.
> 
> How's that for a piece of marble?  Heh...




Looks fantastic!

Which paint did you use to get the top plate with mixed colors?

Is the top plate custom-built? I don't think the stock plate has enough space for 2 chokes alongside the power transformer....


----------



## DenverW

Now the question is: HD800 or ZMF Auteur.....


----------



## bagwell359 (May 19, 2020)

cddc said:


> Looks fantastic!
> 
> Which paint did you use to get the top plate with mixed colors?
> 
> Is the top plate custom-built? I don't think the stock plate has enough space for 2 chokes alongside the power transformer....



Stock plate.  I cut a bit of the plastic protector off the edges of the chokes so it would fit w/o contact.  If I can fashion a cage that looks good and keeps people from touching the chokes they stay up there, but the tab on the back sides will have to be cut, and the front tab screwed down.

It's faux painting with 6 different acrylic paints - the stuff you get at Michael's Craft Store, and a natural sponge and water - instructions on-line.  Oh, also clear coat for that 'wet" look.  It's my first "marble" one, I've fauxed lots of other things before.  The creme colored bits are too thick, and the crossing over the gold is an absolute no no.  I'll thin those out


----------



## bagwell359

DenverW said:


> Now the question is: HD800 or ZMF Auteur.....



C'mon!  Get both, and then tell us what you think!


DenverW said:


> Now the question is: HD800 or ZMF Auteur.....



Buy both!  Then tell us about them, and sell me the "loser" cheap!  

Honestly, can't lose.


----------



## PsilocybinCube

DenverW said:


> Now the question is: HD800 or ZMF Auteur.....


I looked at the Auteur after you mentioned it.  That's never really been on my radar.  It's a beautiful headphone.  

As I've been looking into the HD800, there are certainly some good deals on them from time to time (even the HD800s).  

I've been doing some A/B tests between listening to my HD650 on my BHC vs. some HE-560 v3 running balanced on a Topping DX7Pro.  Depending on the album, the BHC can be a bit too warm or the Topping/HE-560 combo can be a little too light.  There is no Goldilocks.  I love the greater detail and separation of the HE-560 but I hate the lack of body on certain songs.

I'm hoping (and DenverW has kind of inferred this) that the HD800 combined with the BHC gives the best of both worlds.  Then I start looking into the Auteur and I get totally lost all over again.  Now I realize why people buy so many damn headphones.

I'm thinking I'm going to spring for the HD800 (or the 's' variant if I can get a good deal).  Eventually, I would like to put together a Mainline as I'd imagine that makes the HD800 sing even more than the BHC.

Before I commit myself to the HD800 and quite my incessant search for the next headphone...should I seriously consider the Auteur?


----------



## chrisdrop

DenverW said:


> Now the question is: HD800 or ZMF Auteur.....


ZMF all the way


----------



## Wes S

chrisdrop said:


> ZMF all the way


I agree.  ZMF dynamics sound insanely good on the BHC.


----------



## DenverW

Wes S said:


> I agree.  ZMF dynamics sound insanely good on the BHC.



I hear ya'll, but as I was just saying in a PM I really struggle with decisions.  They're actually great as a pair.  The hd800 with sdr mod has better definition and just a great high end, and the crack adds some bass and really improves the tone.  The auteur has better tone overall, and a better low end.  They both sound different on the crack, but both are great in their own way.   I wish I was the kind of person who could hear two different headphones and say, "yep, THAT one is for me..."

This is a good problem to have.  I'm spoiled for choices, and my wallet is spoiled for cash.


----------



## chrisdrop

DenverW said:


> I hear ya'll, but as I was just saying in a PM I really struggle with decisions.  They're actually great as a pair.  The hd800 with sdr mod has better definition and just a great high end, and the crack adds some bass and really improves the tone.  The auteur has better tone overall, and a better low end.  They both sound different on the crack, but both are great in their own way.   I wish I was the kind of person who could hear two different headphones and say, "yep, THAT one is for me..."
> 
> This is a good problem to have.  I'm spoiled for choices, and my wallet is spoiled for cash.


Only one thing to do. Verite.


----------



## DenverW

chrisdrop said:


> Only one thing to do. Verite.



I think you're right....wait, OPEN OR CLOSED!?!?!


----------



## chrisdrop

DenverW said:


> I think you're right....wait, OPEN OR CLOSED!?!?!


Wrong: OPEN OR *AND *CLOSED!?!?!


----------



## cddc

bagwell359 said:


> Stock plate.  I cut a bit of the plastic protector off the edges of the chokes so it would fit w/o contact.  If I can fashion a cage that looks good and keeps people from touching the chokes they stay up there, but the tab on the back sides will have to be cut, and the front tab screwed down.
> 
> It's faux painting with 6 different acrylic paints - the stuff you get at Michael's Craft Store, and a natural sponge and water - instructions on-line.  Oh, also clear coat for that 'wet" look.  It's my first "marble" one, I've fauxed lots of other things before.  The creme colored bits are too thick, and the crossing over the gold is an absolute no no.  I'll thin those out




Can't believe the stock plate can hold 2 chokes on top of it...but it's happening...good effort!

Faux painting is art compared to spray painting...will definitely consider it if I were to build another DIY kit.


----------



## Bullpride

PsilocybinCube said:


> I looked at the Auteur after you mentioned it.  That's never really been on my radar.  It's a beautiful headphone.
> 
> As I've been looking into the HD800, there are certainly some good deals on them from time to time (even the HD800s).
> 
> ...


I have the Atticus, which is has the same driver as the Aeolus (if you're looking for open instead of closed).  Keep an eye out for either used if you're on a budget.  Many can attest and I agree that ZMF and BHC are an ideal pairing.


----------



## JamieMcC (May 19, 2020)

bagwell359 said:


> Here are a few more pics, I was careless and broke something so another 3-4 day delay.  Labor Day is about when the thing will be done.
> 
> Used half cherry and half oak to get the finish.
> 
> How's that for a piece of marble?  Heh...



Nice effect on the top plate with the faux marble when I first saw it I thought you had swirl dipped it. Something I've been planning to try out with a Crack top plate to match a headphone stand I made with a paint swirl dipped finnish.


----------



## DenverW (May 21, 2020)

Blue velvet pot is going in tonight!  I look forward to imagining I hear a hint of a hint of difference!

Edit:  Success!  That was actually a little more complicated than I expected due to the alps pot not having tabs on the solder points, just little sticks.  

Now a strange problem: the alps pot volume knob is longer than the stock tab, which makes the stock volume tab stick up since it doesn't reach the faceplate.  Anyone have a suggestion of a volume knob that would work better?  Preferably black


----------



## bagwell359

DenverW said:


> Blue velvet pot is going in tonight!  I look forward to imagining I hear a hint of a hint of difference!
> 
> Edit:  Success!  That was actually a little more complicated than I expected due to the alps pot not having tabs on the solder points, just little sticks.
> 
> Now a strange problem: the alps pot volume knob is longer than the stock tab, which makes the stock volume tab stick up since it doesn't reach the faceplate.  Anyone have a suggestion of a volume knob that would work better?  Preferably black



People have said you could hacksaw off 1/2".  I haven't done it, I'm going to use a skill saw with a fine metal blade when I do mine.


----------



## DenverW

bagwell359 said:


> People have said you could hacksaw off 1/2".  I haven't done it, I'm going to use a skill saw with a fine metal blade when I do mine.



I suppose that’s one solution!  I was hoping that there would be a larger knob available somewhere that would still look good


----------



## raindownthunda (May 22, 2020)

DenverW said:


> Blue velvet pot is going in tonight!  I look forward to imagining I hear a hint of a hint of difference!
> 
> Edit:  Success!  That was actually a little more complicated than I expected due to the alps pot not having tabs on the solder points, just little sticks.
> 
> Now a strange problem: the alps pot volume knob is longer than the stock tab, which makes the stock volume tab stick up since it doesn't reach the faceplate.  Anyone have a suggestion of a volume knob that would work better?  Preferably black



I found these Audio Note knobs fit the alps blue velvet perfectly (25mm height). I have to admit it was hard to justify paying that much for a knob. But they are amazing quality, feel nice and sturdy, and look great on the crack. I went with full gloss, but they come in a variety of finishes too.


----------



## DenverW

I found one on ebay in black (probably not as good looking as those audio note ones!) that was only about 8 bucks.  Shipping worries me, estimate is currently...July.  I'll just have a non-fitting knob till then .


----------



## Paladin79

My build might give a few of you ideas on cabinet choices. This is walnut with maple splines and solid brushed copper.


----------



## Toad_of_Toad_Hall (Sep 22, 2021)

.


----------



## Paladin79

Toad_of_Toad_Hall said:


> The VU meters look great! Do they add any noise to the circuit? How do you hook them up?


No noise that I can measure or hear. They go on the output stage, use a 12 v supply that I ran separately. Dual volume pots that are simple enough to install. I did another version that is outboard, uses a pre-amp out, tulip poplar with ebony inlays and splines.


----------



## Paladin79

Those amps are for friends. My next venture will be a honey locust cabinet with copper and maybe holly splines.


----------



## Toad_of_Toad_Hall (Sep 22, 2021)

.


----------



## DenverW

Paladin79 said:


> Those amps are for friends. My next venture will be a honey locust cabinet with copper and maybe holly splines.



Clearly I need better friends .


----------



## Paladin79 (May 23, 2020)

Toad_of_Toad_Hall said:


> Source for the meters?


Amazon or Ebay, they are not expensive but they can take a while to receive. I just noticed this seller and the price is very good.

https://usa.banggood.com/2-Pcs-VU-M...LMmHZ2G1UsvcJphoCZ1AQAvD_BwE&cur_warehouse=CN

It took me a while to find a hole cutter the perfect size but I have used these meters a lot and will continue to do so. I compare different headphone amps a lot and the meters are quick reference for me on signal level. 



.


----------



## wwmhf

Paladin79 said:


> My build might give a few of you ideas on cabinet choices. This is walnut with maple splines and solid brushed copper.



A classy amp ...


----------



## Paladin79 (May 24, 2020)

wwmhf said:


> A classy amp ...


Brushed copper can be time consuming but I love the effect. This is the start of a top plate for my own amp.



thanks


----------



## MRHiFiReviews

Hey Friends!!  Check it out...a quick video I did with a fun montage unboxing of the Bottlehead Crack OTL 1.1 Headphone Amplifier!  I hope you dig it, I will post up more audio gear videos to the channel soon.  Please consider subscribing to the channel and drop me a like on the YouTube video if you don't mind and let me know if you want to see part 2 and 3 of this video series in the comments! Have a safe and great start to your week.

MR


----------



## wwmhf

It should be continued ... until music comes out it ...


----------



## Wes S

MRphotography said:


> Hey Friends!!  Check it out...a quick video I did with a fun montage unboxing of the Bottlehead Crack OTL 1.1 Headphone Amplifier!  I hope you dig it, I will post up more audio gear videos to the channel soon.  Please consider subscribing to the channel and drop me a like on the YouTube video if you don't mind and let me know if you want to see part 2 and 3 of this video series in the comments! Have a safe and great start to your week.
> 
> MR



Hey man!  Nice to see you over hear!


----------



## chrisdrop

I am quite well equipped in the headphone amp department, but, I also want to learn to build 'em. So, I'll build a Crack+Speedball to start that journey.

In terms of parts/ performance upgrades, I think we have:

Potentiometer - a good stepped attenuator can cost as much as the Crack, but an Alps pot seems a good balanced upgrade?
Resistors - Looking for thoughts here. Looks like sometimes a choke is used in place of one resistor post power-supply to reduce power noise too. Hammond? Wire-wound replacements - Mills?
Caps - You can spend quite a bit here. Some can also be huge. Looking for thoughts here.
Anything else?
Question:
I assume it is best to build it to manual spec first (no changed parts), then make changes? Is that the case? Anything worth just doing during the initial build?


----------



## MRHiFiReviews

Wes S said:


> Hey man!  Nice to see you over hear!



Thanks Wes!


----------



## Bullpride

chrisdrop said:


> I am quite well equipped in the headphone amp department, but, I also want to learn to build 'em. So, I'll build a Crack+Speedball to start that journey.
> 
> In terms of parts/ performance upgrades, I think we have:
> 
> ...


Chris,

I recently finished my build, and am asking some of the same questions you are. 

1. Definitely build the stock crack first.  Listen to it for a while.  Then do the speedball.  You can even do the speedball in stages.  This has helped me start to recognize the differences in sound for each upgrade.  
2. Potentiometer and Attenuators.  There seem to be two suggested quite a bit:
One made by PEC
https://www.digikey.com/product-detail/en/KKA1041S28/KKA1041S28-ND/770961
The Alps Blue Velvet you mentioned:
https://www.parts-express.com/alps-...xte0RvVVRp4zTxgRciDFUTM59-A_3scRoCnikQAvD_BwE
3. Chokes - I think these fall under the "not necessary" category by the Bottlehead folks, but others suggest them
4. Caps - worthwhile upgrades, though I haven't done a lot of digging.  The article below does a great job of outlining each of the suggested upgrades, with a decent break down of the individual Cap suggestions. 
https://www.headphonesty.com/2019/04/upgrading-bottlehead-crack-headphone-amplifier/
5. I also found this article.  The author commented on my post in "I love my Bottlehead" Group on Facebook.  Moving one of the signal wires away from another group of wires cleaned up some noise I was hearing
https://www.hificollective.co.uk/bl...TyqZd_IqqNRs5S5pYOo5qtTTMObzAzVQaCDCnR1yX22Ec

This response is for you, but also so I have a handful of notes for myself, ha.  The Bottlehead forum and this thread are an excellent source if you have additional questions.  The folks on the forum are more than happy to help you troubleshoot.


----------



## PsilocybinCube

Quick question everyone - I am purchasing a 12au7 to 6sn7 adapter for my BHC with Speedball.  

Can I simply drop in the tube and adapter?  Do I need to do anything relative to the existing 12au7 socket?  

I purchased this 2nd hand from DenverW and am still learning.  I don't want to fry this baby!

On another note, I purchased a set of Hd800 headphones to pair with the BHC and will post some impressions later with different tube combos.


----------



## Wes S

PsilocybinCube said:


> Quick question everyone - I am purchasing a 12au7 to 6sn7 adapter for my BHC with Speedball.
> 
> Can I simply drop in the tube and adapter?  Do I need to do anything relative to the existing 12au7 socket?
> 
> ...


Just drop it in, and enjoy.  I just recently started rolling my 6SN7's with an adapter after a year of rolling all the best 12AU7's, and I will never roll another 12AU7 in my BHC again.  The 6SN7 really takes things to another level, with the right tube combo.


----------



## PsilocybinCube

Wes S said:


> Just drop it in, and enjoy.  I just recently started rolling my 6SN7's with an adapter after a year of rolling all the best 12AU7's, and I will never roll another 12AU7 in my BHC again.  The 6SN7 really takes things to another level, with the right tube combo.



Well, I am freaked out.  I tried out the adapter and the 6sn7 for about 10 seconds only to see a small amount of greyish/white smoke emitting beneath the adapter.

I purchased the adapter from what looked to be a good Ebay seller (I also have an order for one from a user here on Head-fi) but I wasn't willing to let it stay on once I saw that smoke.  I requested their 6.3V option that they stated worked well with the BHC.

Am I being paranoid?  Do I just need to let them run for a bit and see how it shakes out?  

https://www.ebay.com/itm/GARAGE1217...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649


----------



## Bullpride

I haven't started rolling on my crack  yet, but am considering it.  I will probably make my way through the standard ones before using an adapter.  Isn't there someone on Head-fi that makes adapters?


----------



## chrisdrop

Bullpride said:


> I haven't started rolling on my crack  yet, but am considering it.  I will probably make my way through the standard ones before using an adapter.  Isn't there someone on Head-fi that makes adapters?


@Deyan or xulingmrs on eBay


----------



## Wes S

chrisdrop said:


> @Deyan or xulingmrs on eBay


And Garage 1217, makes great ones as well, and you don't have to wait weeks for shipping, if you are in the States.


----------



## Wes S

PsilocybinCube said:


> Well, I am freaked out.  I tried out the adapter and the 6sn7 for about 10 seconds only to see a small amount of greyish/white smoke emitting beneath the adapter.
> 
> I purchased the adapter from what looked to be a good Ebay seller (I also have an order for one from a user here on Head-fi) but I wasn't willing to let it stay on once I saw that smoke.  I requested their 6.3V option that they stated worked well with the BHC.
> 
> ...


I am using the same adapter, with zero issues.  I have never seen smoke, and would be concerned.  Maybe try a different tube. . .


----------



## PsilocybinCube

Wes S said:


> I am using the same adapter, with zero issues.  I have never seen smoke, and would be concerned.  Maybe try a different tube. . .


I should note that the smoke didn't appear to be coming from the tube, but just below the adapter, where it meets the amp.
If I turn on the amp with the adapter plugged in but no tube (to allow any residue on the adapter to burn off) will that damage the amp?  Running just the power tube and the adapter to see if the smoke stops? 
I would think that should be a safe approach, but again, I'm a neophyte.


----------



## PsilocybinCube

chrisdrop said:


> @Deyan or xulingmrs on eBay


@Deyan has made me an adapter...waiting on international shipping issues to get to the US


----------



## Wes S

PsilocybinCube said:


> @Deyan has made me an adapter...waiting on international shipping issues to get to the US


I am still waiting on mine too, and really hope to get mine soon.


----------



## Wes S (May 27, 2020)

PsilocybinCube said:


> I should note that the smoke didn't appear to be coming from the tube, but just below the adapter, where it meets the amp.
> If I turn on the amp with the adapter plugged in but no tube (to allow any residue on the adapter to burn off) will that damage the amp?  Running just the power tube and the adapter to see if the smoke stops?
> I would think that should be a safe approach, but again, I'm a neophyte.


Honestly, I don't think there should be any residue to burn off, and I wonder if they didn't send you the wrong adapter.  Can you confirm it is the 6.3v version?  I would get in touch with Garage 1217, and ask them if they know what is going on.  There should never ever be any smoke.


----------



## PsilocybinCube

Wes S said:


> Honestly, I don't think there should be any residue to burn off, and I wonder if they didn't send you the wrong adapter.  Can you confirm it is the 6.3v version?  I would get in touch with Garage 1217, and ask them if they know what is going on.  There should never ever be any smoke.


I requested the 6.3v but don't know how to confirm.  I did touch base with Garage1217 to verify.


----------



## PsilocybinCube

PsilocybinCube said:


> I requested the 6.3v but don't know how to confirm.  I did touch base with Garage1217 to verify.



Here's a pic of the underside of the adapter and the tube.


----------



## Wes S

PsilocybinCube said:


> Here's a pic of the underside of the adapter and the tube.


I will take a look at my adapters from Garage 1217 when I get home, to see if they look the same.


----------



## PsilocybinCube

Wes S said:


> I will take a look at my adapters from Garage 1217 when I get home, to see if they look the same.




Two more pics.  The adapter does make contact with the screws at 12 & 6 o'clock.  Not sure if that matters.


----------



## Wes S

PsilocybinCube said:


> Two more pics.  The adapter does make contact with the screws at 12 & 6 o'clock.  Not sure if that matters.


Are the solder joints on the adapter on the underside touching any metal?


----------



## Tom-s

There's probably your problem. Your adapter is now shorted to ground where it shouldn't. This could lead to serious damage inside your amplifier (with bad luck even the PT).
Your tube socket appears not to be sitting on top of your chassis plate, there's your problem.


----------



## Wes S

Tom-s said:


> There's probably your problem. Your adapter is now shorted to ground where it shouldn't. This could lead to serious damage inside your amplifier (with bad luck even the PT).
> Your tube socket appears not to be sitting on top of your chassis plate, there's your problem.


I agree.


----------



## Wes S (May 27, 2020)

@ PsilocybinCube - I notice the socket for the 12AU7 on my BHC sits up higher than yours, and so I have no issues with this adapter.  If there has been no damage to your BHC or adapter, try not inserting it all the way down to the top plate, to avoid contact with solder joints, and see if that works.


----------



## PsilocybinCube

Here was the reply from Garage over at Ebay:


*Hello, That would be the problem - this amp was built with the tube socket on the bottom side of the top plate. Most are built on the top side. We have a note in our listing:

"Our adapters are PCB based and have an open bottom to the PCB. If your tube socket is recessed below a metal plate in the chassis, please message us to verify fitment to make sure the adapter will not short to your chassis."

Good news is, it likely did no damage. Most cracks are built with the socket on the top side like this photo.

I could attempt to make you a spacer that would sit our socket about 1/8" higher than it sits now, but you would need to verify fitment. As it stands, that socket sits so far down into the hole... hard to tell if it will clear that large screw. Let me know your thoughts on it.*


It makes sense.  

I'm going to see about remounting the tube socket such that it sits above the PCB like the Crack in this photo:





I would think that is the easiest fix, right?

On another note, because the adapter was only in the BHC and turned on for 3-4 seconds, nothing seems to be wrong.  I've been listening this morning while working and have throw in two different 12au7 tubes and can't hear any noise or degradation in sound.  And to clarify, the pics I posted with the adapter in the BHC were with the amp turned off!!!


----------



## Wes S

Speaking of adapters, look what just got delivered.   The quality of this adapter, feels as good as it can get.  I love how @Deyan, used really high quality parts, which makes rolling a breeze.  I highly recommend getting in touch with @Deyan, if you are looking for a quality adapter built to your specifications.  He made it exactly how I requested, and this will not be my last adapter purchase.


----------



## attmci

Tom-s said:


> There's probably your problem. Your adapter is now shorted to ground where it shouldn't. This could lead to serious damage inside your amplifier (with bad luck even the PT).
> Your tube socket appears not to be sitting on top of your chassis plate, there's your problem.


Yes, that fix ring of the socket is missing. 

How are u doing, Tom?


----------



## Paladin79

I am trying to avoid cutting holes in this particular cabinet so top mounted pots on this one. Copper supports that I can patinate to match if I want.


----------



## JTori

Paladin79 said:


> I am trying to avoid cutting holes in this particular cabinet so top mounted pots on this one. Copper supports that I can patinate to match if I want.



Love the patinated chassis plate!  And the grain on that base ... !


----------



## Paladin79

JTori said:


> Love the patinated chassis plate!  And the grain on that base ... !


The base is honey locust, no finish on it whatsoever yet, I will use a router on the top so the top plate is inset and then I do corner supports.


----------



## JTori

*Color Me Enamored*

I'm totally intoxicated by the sound of my recently completed Crack-a-two-a.  There's an immediacy to the sound, which fosters a real emotional connection for me.  I've rolled a couple tubes and settled -- for now -- on a mil-spec Sylvania JHS 6189-12AU7WA in the input-tube position, NOS Chatham Electronics 6080WB with slotted graphite columns in the output position and a pair of NOS GE 5-star 6005s in the shunt-regulator spots.  The overall character is one of crystalline clarity, airiness and silky smoothness in the mids and highs with well-rounded, incisive, punchy and robust low end when called for.  So glad I made the decision to purchase this fine amp!  And on top of that, there was the bonus of being able to immerse in the build process.  

Here are a couple test shots I made with my iPhone earlier today.  I plan to make some more nicely arranged, composed and post-processed images with my full-frame mirrorless once I've installed the TwoQuiet upgrade.  

Joe.


----------



## carlman14

I've had my crack for about a year and a half now, and I think I'm finally done upgrading (for now). Here's the final product:

speedball
stained/finished base
film output caps
film cap for last psu cap (with bypass)
24 step goldpoint attenuator with vishay dale resistors
Schottky rectifier diodes
choke
integrated khadas tone board with usb-c input on the top panel (It's an all-in-one unit now!).
toggle switch for switching between onboard dac and an external dac.
Very pleased with how this turned out.


----------



## Bullpride

carlman14 said:


> I've had my crack for about a year and a half now, and I think I'm finally done upgrading (for now). Here's the final product:
> 
> speedball
> stained/finished base
> ...


I am digging the internal DAC mod.  What DACdid you use? Or did you build it from a kit/scratch?


----------



## PsilocybinCube

Have you 


carlman14 said:


> I've had my crack for about a year and a half now, and I think I'm finally done upgrading (for now). Here's the final product:
> 
> speedball
> stained/finished base
> ...


This is beautiful.  What a nice product you've fashioned.

Do you get any USB interference from the USB-C or the DAC being so close to the electronics?  If not, did you have to do any troubleshooting to help with that?

Really great job!  I'm super jealous.


----------



## carlman14

Bullpride said:


> I am digging the internal DAC mod. What DACdid you use? Or did you build it from a kit/scratch?



It was a fun mod for sure! I am using the khadas tone board. No DIY necessary. It's just a pre-built super tiny dac board with a nice DAC chip on it.



PsilocybinCube said:


> This is beautiful. What a nice product you've fashioned.
> 
> Do you get any USB interference from the USB-C or the DAC being so close to the electronics? If not, did you have to do any troubleshooting to help with that?
> 
> Really great job! I'm super jealous.



Thanks! So far, there hasn't been any kind of interference. Everything is incredibly quiet.


----------



## Tom-s

attmci said:


> How are u doing, Tom?



I've had better day's! Here's why:


The *Thomson 6080* is a personal favorite of mine. It's a clean, clear, airy, wonderful sounding tube that brought me a lot of joy! So I've recommended it to a few people.

Recently there's been various reports online (and offline) about the ones coming from sellers in Eastern Europe not functioning as they should.

Six of those found their way to me and i've had some fun with the testers today, checking them out. 

They are supplied in HUGE boxes with some labels and a sticker on top. You could throw these of your local apartment building without anything happening to the tubes.

In the testers i couldn't detect any short or gas, so that's good. When required to supply any current at all, just about nothing happened. 

In a transconductance tester where 7mA/V is the nominal NOS value, the best got up to 2mA/V.

Here's a picture of the line-up.




Luckily i had one good sample from my own collection to listen to!

Unfortunately, that one had sort of a bad interaction with my floor  (hence, the bad day).



So it was dissected for the sake of curiosity.



Here's a view on one half:
- The coated heater wiring 
- The cathode wherein the heater wiring lives
- The grid wire in nicely even spacing
- The anode plates with a large surface area for cooling
- All is suspended in a rigid mica construction seen on the previous image.



It's no Thomas Mayer picture quality (it's a phone!), but i hope you guys enjoyed it anyway!


----------



## carlman14

Tom-s said:


> Recently there's been various reports online (and offline) about the ones coming from sellers in Eastern Europe not functioning as they should.



I can echo that statement. I ordered 3 of these tubes from a seller in Europe last year. All 3 were bad. Two were dead in one channel (one may have been dead in both channels, don't remember), and the other arc'd, blowing out my Atticus drivers. I haven't bothered with them since.


----------



## cddc

Tom-s said:


> Recently there's been various reports online (and offline) about the ones coming from sellers in Eastern Europe not functioning as they should.
> 
> Six of those found their way to me and i've had some fun with the testers today, checking them out.
> 
> ...




Sorry to hear what happened to your working Thomson and those duds, Tom.

Just wondering where they got the new boxes for the duds? Those boxes look authentic, but why would they replace a NIB tube with a dud inside the box?

Also curious about the filament from your photo. The way how the filament is wound and how it is placed inside the cathode makes me wonder why a short is not happening? The filament is touching itself and the metal cathode in so many places. A short should have happened unless the filament is coated with insulating materials.


----------



## cddc (Jun 3, 2020)

Will the frequent thermal expansion and contraction from the big changes in filament temperature peel away the insulating coating over time?


----------



## wwmhf

Tom-s said:


> I've had better day's! Here's why:
> 
> Unfortunately, that one had sort of a bad interaction with my floor  (hence, the bad day).
> 
> ...



Sorry for you loss, but now you and all of us know that this tube is well made


----------



## attmci

carlman14 said:


> I can echo that statement. I ordered 3 of these tubes from a seller in Europe last year. All 3 were bad. Two were dead in one channel (one may have been dead in both channels, don't remember), and the other arc'd, blowing out my Atticus drivers. I haven't bothered with them since.


Wow, that's sad.


----------



## carlman14

attmci said:


> Wow, that's sad.



Yeah I was pretty bummed for my Atticus. Luckily I was the original owner, so the driver replacement was free. That whole Thomson 6080 experience sucked though. It's amazing how many people are reporting receiving bad Thomson 6080s from Europe lately.


----------



## raindownthunda (Jun 5, 2020)

carlman14 said:


> I've had my crack for about a year and a half now, and I think I'm finally done upgrading (for now). Here's the final product:
> 
> speedball
> stained/finished base
> ...



The internal dac mod is genius! Really cool build


----------



## headpfizer

I just came into posession of a crack 1.1 With Speedball and Murdof Caps. It came with a selection of tubes. Can anyone recommend me some good combos from this list?

Power valves are:
Mullard 6080 SB CV 2984 KB/D made in England.
GEC valve made in uk, 6080 CV 2984 KB/Z.
Svetlana winged C NOS bottle shape, 6AS7G
Thomson CSF 6080WA ruggedised double power triode.
Philips ECG Jan 6080WC 3 mica.
Raytheon 6080.

Input valves are:
Vintage RCA NOS black plate Aug 1953, 12AU7
Mullard NOS CV4003 12AU7A
Jan Philips ECG 12AU7 5963
Electro Harmonix gold pins 12AU7/ECC82
JJ electronic ECC82 12AU7

Input valves with supplied 6SN7 to 12AU7 ADAPTER.
Tung Sol 6SN7 GTB.
Sylvania 6SN7 GTB
Electro Harmonix 6SN7GT.


----------



## chrisdrop

headpfizer said:


> I just came into posession of a crack 1.1 With Speedball and Murdof Caps. It came with a selection of tubes. Can anyone recommend me some good combos from this list?
> 
> Power valves are:
> Mullard 6080 SB CV 2984 KB/D made in England.
> ...


*GEC 6080
Sylvania 6SN7 GTB or  Tung Sol 6SN7 GTB.*


----------



## JamieMcC

Gec 6080 + Mullard 4003 would be my pick of the bunch 6sn7 should be great also.

Have fun


----------



## carlman14

headpfizer said:


> Can anyone recommend me some good combos from this list



My vote also goes to the GEC 6080 + whatever. Great tube. If you haven't read the last page or two on this thread... I'd stay away from that Thomson 6080 if I were you.


----------



## DenverW

Hi all!  Question for those of you that have installed a choke:  how did you mount it?  To the faceplate, or with standoffs?  Did you do any extra ground wiring or just a simple replacement of one of the 270 5v?

I'm also waiting for some 100uf kzk white line film caps from russia...one month down and who knows how much more to wait?


----------



## penguinofsleep2 (Jun 5, 2020)

Assuming all of the above work, you hit the lottery on the power tubes. GEC is the obvious answer but side from it:

Thomson + Brimar is a great combo for a more "relax-fi" and easy listening sound without turning into mushy warm-poo. Given that the issues people had with the Thomson tubes have all been recent purchases, I'm guessing a bad/reject batch (or batch of dead tubes) got pulled out of a warehouse somewhere - but known good tubes are a good time.

Svetlana + Philips 12AU7 may also be a very good time. I have an unknown 12AU7 that looks to be of Philips construction + a black plate Svetlana - was may favorite combo excluding $$$ combos (such as GEC + w/e) given that I didn't want to chase down $$$ tubes for BH Crack (amp + mods + $$$ tubes = ~1k, there are amps better than the typical modded crack you can buy for 1k, including other BH stuff).


----------



## carlman14

DenverW said:


> Hi all! Question for those of you that have installed a choke: how did you mount it? To the faceplate, or with standoffs? Did you do any extra ground wiring or just a simple replacement of one of the 270 5v?



Hey there! I used 25mm standoffs to mount the choke to the faceplate. Something like this: https://www.mouser.com/ProductDetail/693-9832.5200. Female end is screwed into the faceplate, and the holes for the choke's bracket go through the male ends of the standoffs and held in place with nuts. This can also be done with female-female standoffs too. 

Yes, it is used to replace one of the 270 ohm 5W resistors. I also added a ground wire going from underneath one of the nuts to ground. For placement, most people mount it such that the screws for the standoffs are just behind the power transformer. You can see those 2 black screws in the back of my faceplate in my pictures a few posts ago. Those are for the choke standoffs.

Hope this helps!


----------



## attmci

headpfizer said:


> I just came into posession of a crack 1.1 With Speedball and Murdof Caps. It came with a selection of tubes. Can anyone recommend me some good combos from this list?
> 
> Power valves are:
> Mullard 6080 SB CV 2984 KB/D made in England.
> ...


GEC 6080, cv4003, 6sn7 to 12au7 adapter.


----------



## PsilocybinCube

attmci said:


> GEC 6080, cv4003, 6sn7 to 12au7 adapter.


Wow, you got the hook-up on the tubes.  I'm a relative newbie to the BHC, but I purchased a couple of Winged C tubes and am in love with it.  For the power tube, it gets my vote.


----------



## DenverW

carlman14 said:


> Hey there! I used 25mm standoffs to mount the choke to the faceplate. Something like this: https://www.mouser.com/ProductDetail/693-9832.5200. Female end is screwed into the faceplate, and the holes for the choke's bracket go through the male ends of the standoffs and held in place with nuts. This can also be done with female-female standoffs too.
> 
> Yes, it is used to replace one of the 270 ohm 5W resistors. I also added a ground wire going from underneath one of the nuts to ground. For placement, most people mount it such that the screws for the standoffs are just behind the power transformer. You can see those 2 black screws in the back of my faceplate in my pictures a few posts ago. Those are for the choke standoffs.
> 
> Hope this helps!



Thanks!  Is there an orientation for the two choke wires or can either wire go to either terminal of the 270 its replacing?


----------



## carlman14

DenverW said:


> Thanks! Is there an orientation for the two choke wires or can either wire go to either terminal of the 270 its replacing?



Either choke wire can go to either terminal.


----------



## DenverW

At 1:42 doc b sent out an email about three crackatwoa kits going on sale for 150 off.  I didn't see the email until 5:50 and they were gone.  Sad face!


----------



## Toad_of_Toad_Hall (Sep 22, 2021)

.


----------



## DenverW

Did the choke mod today.  Replaced the resistor that crosses the transformer.  Why that one?  It was easier .  Ran a ground wire from one of the screws holding it in place.  Had some minor fit issues.  

I assume all is well as voltage checks came back the same and it sounded good.  Thanks for help!


----------



## attmci (Jun 7, 2020)

Tom-s said:


> I've had better day's! Here's why:
> 
> 
> The *Thomson 6080* is a personal favorite of mine. It's a clean, clear, airy, wonderful sounding tube that brought me a lot of joy! So I've recommended it to a few people.
> ...


Tom, who is selling these fake  *Thomson 6080* tubes? I am trying to collecting the names of entrusted ebay sellers, and please feel free to add your findings.

https://www.head-fi.org/threads/over-priced-tubes.920115/


----------



## PsilocybinCube

attmci said:


> Tom, who is selling these fake  *Thomson 6080* tubes? I am trying to collecting the names of entrusted ebay sellers, and please feel free to add your findings.
> 
> https://www.head-fi.org/threads/over-priced-tubes.920115/


I have a Thomson 6080 on the way...now I'm nervous!  Will let you know seller's name if it sounds good!


----------



## JTori

A couple images I made this afternoon of my Crack-a-two-a with the TwoQuiet upgrade installed. 

Best,

Joe.


----------



## attmci

PsilocybinCube said:


> I have a Thomson 6080 on the way...now I'm nervous!  Will let you know seller's name if it sounds good!


Good luck with your purchase.


----------



## GreenNeedle (Jun 8, 2020)

Just thought I would join the Crack love in.  Mine is still a WIP at the moment.  I had originally planned on a Santos Rosewood base with polished chassis but I'm not so keen once I saw it in place.  Love the base, not sure on the polished plate.  In the pics below the plate is nearly fully polished.  Still has a slight haze but I stopped when I had doubts.

The base is not finished yet.  Still some Oil to add on with fine W&D to get the last remnants of saw marks off the sides.  Feet still to be added.

The actual unit is fully wired and working but I may have to (quite likely will) have to unsolder a few wires to take the hardware off the plate.  I have also bought a TKD 2CP-2511 to replace the stock pot.

So what I am thinking at the moment is for the plate to be a cream enamel like very old electronics used to have.  Also to paint the sides of the transformer as it does have some sloppy resin marks all over using the same hammered black as the bell.  Also want to paint the 12AU7 socket clamp with the same paint.

Will have a think over the week before deciding what to do and of course will hold off the speedball upgrade until it is all back together again.

These photos show the stock volume knob but I am changing that as well. lol.


----------



## JTori

GreenNeedle said:


> Just thought I would join the Crack love in.  Mine is still a WIP at the moment.  I had originally planned on a Santos Rosewood base with polished chassis but I'm not so keen once I saw it in place.  Love the base, not sure on the polished plate.  In the pics below the plate is nearly fully polished.  Still has a slight haze but I stopped when I had doubts.
> 
> The base is not finished yet.  Still some Oil to add on with fine W&D to get the last remnants of saw marks off the sides.  Feet still to be added.
> 
> ...



The rosewood base you've created is absolutely gorgeous!  And I respect your deliberative approach to finishing out the Crack.  It will be both audibly and aesthetically appealing.  Making the amp yours is a big part of the build process, in my opinion.  Can't wait to see it once it's completed.

Best,

Joe.


----------



## DenverW

Gotta agree there, that base looks absolutely amazing.  If everything inside looks as good as outside then you're going to have one great little amp!


----------



## GreenNeedle

Thanks guys but a little surprised really.  Base looks terrible in its WIP state there.  Will look much more lively and shiny once its finished.  Once it is fully oiled light will make it look much more 3D and probably a little lighter in colour than at the moment.


----------



## DenverW

Question for anyone who has installed cree diodes: after installing the diodes and wiring the 4 points do you remove the existing wires going from the right terminal strip to the power?  I believe its something like 18 and 19L?  Any other wiring changes necessary?


----------



## carlman14

DenverW said:


> Question for anyone who has installed cree diodes: after installing the diodes and wiring the 4 points do you remove the existing wires going from the right terminal strip to the power? I believe its something like 18 and 19L? Any other wiring changes necessary?



Yes, remove the two wires going from 18 and 19 to the power transformer. The whole wiring changes should be: remove the existing diodes, remove the wires from 18 and 19 to the power transformer, then wire up the 4 cree diodes. There's a pic somewhere in the bottlehead forums detailing the 4 wires from the cree diodes and where they go.


----------



## cddc (Jun 8, 2020)

I saw the cree diode upgrade once, but don't quite understand its benefits (except using larger and better diodes)?

The 4 diodes used in the stock Crack is a simple bridge rectifier, so basically 4 diodes form a diamond bridge where you feed AC into its 2 corners and get DC out of the other 2 corners. The cree diode upgrade uses 4 larger and better diodes (which is an upgrade obviously), but it also uses a PCB to link its 4 diodes (which is a downgrade IMO - I prefer solid core wire connection to PCB connection anytime). If I were to implement the cree diode upgrade, I will just buy 4 larger/better diodes and use solid core wires to solder a bridge rectifier.

Then again I'm an electronic newbie and don't quite understand the benefits of using larger/better diodes. Can someone with better knowledge explain the benefits of cree diode upgrade? Thanks a lot.


----------



## flailure

Hello, 

Recently acquired a bottlehead crack and while it is functional it did sustain some damage in shipping.  The person I bought it from is being very helpful in trying to help me figure out how to fix it, but I don't want to be a pest, I'm working on getting the stuff I need to do the repair, and I have a good idea how to do it with one exception, can't seem to find much on how to remove the damaged portion so that it can be replaced.  The only thing I've come across so far is for removing solder from a pcb, which may just as well apply to this situation, but I wanted to see if anyone could point me in the right direction.  I'm was wondering if maybe the leads are long enough where I can just cut them and still have enough length to remake the connections, but I'm thinking no, some of the components are literally attached straight.  I will upload a picture so that you can see the part that needs to be replaced.  Would appreciate some suggestions.





I found some turrets and have them on order, but as you can see, (apologies about the poor photo) it's snapped off on both sides and was mashed into the transformer, I pulled it up and away and like I said, its certainly functional, but I would like to repair it.  The outside diode looks like there wouldnt be enough length left on it if I just cut it and I definitely will have to figure out how to remove and refit the capacitor considering its right at the post.  I know my dad could fix this, he used to build stuff like it, but I didnt want to bother him with it as his health is really bad right now.  Besides, it is about time I guess for me to learn how to do stuff on my own.


----------



## DenverW

Don't worry, this isn't too catastrophic .  First thing is I believe you can get replacement parts for a reasonable cost directly from bottlehead if you email them and explain.  If that's not an option mouser has many of the parts available, including the capacitor pictured.  If I'm remembering the panel construction properly I believe you'll be able to just heat up and remove the resistors and wires from the little board there, remove the nuts holding it, and replace it with a new one.  Then solder everything back in and recheck resistances and voltages.  Did you get a manual when you bought it from him?

Perhaps someone can chime in if I'm missing something obvious?


----------



## DenverW

You thought it was dead, buried, and gone.

But NO!  Its the return...of FRANKENCRACK!  Now looking even more ridiculous due to a socket saver in the 12au7 socket, its twin Mullard Cv6 black plate tubes.  What the Frankencrack loses in spouse approval it gains in delicious sound.  My previous crack had a gain issue with this tube type, but its fixed and ready to lurch!


----------



## cddc

flailure said:


> Hello,
> 
> Recently acquired a bottlehead crack and while it is functional it did sustain some damage in shipping.  The person I bought it from is being very helpful in trying to help me figure out how to fix it, but I don't want to be a pest, I'm working on getting the stuff I need to do the repair, and I have a good idea how to do it with one exception, can't seem to find much on how to remove the damaged portion so that it can be replaced.  The only thing I've come across so far is for removing solder from a pcb, which may just as well apply to this situation, but I wanted to see if anyone could point me in the right direction.  I'm was wondering if maybe the leads are long enough where I can just cut them and still have enough length to remake the connections, but I'm thinking no, some of the components are literally attached straight.  I will upload a picture so that you can see the part that needs to be replaced.  Would appreciate some suggestions.
> 
> ...




Sorry to hear about the damage in shipping.

I agree with DenverW, it would be a good idea to contact Bottlehead for a terminal strip replacement. 

The repair work is not an easy one. Make sure to take some photos before you start so that you know where each component goes and the polarity/direction of the diodes. Also pay attention to the nylon washers between the transformer and terminal strip that hold the transformer in place.


----------



## cddc

DenverW said:


> You thought it was dead, buried, and gone.
> 
> But NO!  Its the return...of FRANKENCRACK!  Now looking even more ridiculous due to a socket saver in the 12au7 socket, its twin Mullard Cv6 black plate tubes.  What the Frankencrack loses in spouse approval it gains in delicious sound.  My previous crack had a gain issue with this tube type, but its fixed and ready to lurch!




The Frankenstein looks pretty weird , but the WE 421A looks gorgeous. Always wanted one, but the ongoing price is just crazy. Hopefully someday will find one.

Have you compared the Cree diode upgrade before vs after? Interested in how much improvement it brings.


----------



## DenverW

cddc said:


> The Frankenstein looks pretty weird , but the WE 421A looks gorgeous. Always wanted one, but the ongoing price is just crazy. Hopefully someday will find one.
> 
> Have you compared the Cree diode upgrade before vs after? Interested in how much improvement it brings.



My PCB hasn’t arrived yet, so just listening to the choke I put in recently to get a feel for the most recent upgrade.  Next steps are to do the Cree diodes, swap out two of the PS caps for 470uf nichicons, and then swapping the final ps cap with a 100uf Panasonic, then bypassing with a 1uf Mundorf, and then bypassing that with a .01uf audyn true copper max.  I love upgrade tinkering!

I have some kzk white line caps coming for the output caps, but shipping from Russia is so ridiculously slow that it will end up being the last upgrade I do.

And hey, for fun if you ever get a 12au7 to 7193 adapter the 7193 and cv6 tubes are really fun, and VERY good (And cheap!)


----------



## cddc

Cool, seems you got lots of good stuff for your Crack. Just do it one by one slowly so that you could tell us the difference each upgrade brings. 

I always regret I did the Speedball upgrade too fast - only 3 days after the completion of Crack. So haven't got a good handle on how the stock Crack sounds, although I'm pretty sure it sounded already pretty good and tubey...lol

Regarding the caps I'm not sure if we should go with those NOS ones. I know some caps will dry out after certain years, especially those electrolytic caps. Are those old Russian caps gonna work properly?


----------



## DenverW (Jun 9, 2020)

Edit:  I will say that I wouldn't order from Russia again unless things change.  Its looking like at least 2 months to get the caps, and possibly as much as three.  Crazy long shipping and wait times.  

Actually the kzk line isn't NOS, they're new.  Since there wasn't a huge selection of 100uf caps, especially ones that will fit, and I didn't want to pay an obscene amount or drop too low in uf I thought I'd give them a try.  The previous line got some good feedback, so I have high hopes for these, and they didn't cost much at all.  Here is the review for their previous line:

KZK K78-34 250VAC / 375VDC - 5% tolerance


Technical specifications (according to manufacturer): "K78-34 - Brand new Russian audio capacitors; special design of KZK (Kuznetskiy Zavod Kondensatorov, established 1958) brand, based on military grade capacitors K73-16. Taking into account the purpose of this capacitor, sound systems, we produce them with following features: we replaced PET to state-of-the-art polypropylene film, which is more "musical" dielectric and industry standard in audio applications; we use special film with heavy Al-Zn edges for low dissipation factor and more clarity in highs; in contrast to traditional capacitor metal end spraying with Zn + Alloy we use only ultra-pure Zn with special grain structure in order to eliminate parasitic effects in contact areas; our proprietary electrical and thermal treatment allows to get very stable parameters of capacitors and also gives natural musical tone without any harshness of high-order harmonics. Tech Specs: available at ratings of 250Vdc, 400Vdc, 630Vdc, 1000Vdc; capacitance range 0,01 to 100µF; capacitance tolerance ±5%; dissipation factor less than 0,002; operating temperature range -60ºC to +85ºC; insulation resistance greater than 100.000 MO; life expectancy 219.000 h; case material: aluminium tube."


Sound: The KZK K78-34 is a full bodied, slightly warmish sounding capacitor with a very smooth top end. The tonal balance gives slightly more attention to the lower part of the treble making it not as finely detailed as Mundorf capacitors for example but which does give it a nice intimate character that is very pleasing on long term listening sessions. The smooth top end gives a calm and natural presentation that is slightly on the dark side of neutral. As a reality check I compared the K78-34 with the absolutely ruler flat (and far more expensive) Duelund RS-Cu. The Duelund sounded in a direct A-B comparison more open in the top end and overall more balanced. Switching to the other end of the scale, comparing the K78-34 with standard quality MKP's such as the Intertechnik Audyn Q4 or Solen Fast Cap PB-MKP-FC, you notice how nicely full-bodied and rich the presentation of the K78-34 is. It can get a little bit muddy on complex orchestral works or massed choir music but I guess that is due to it being slightly on the dark side of neutral. The soundstage is placed slightly in front of the speakers, again making the overall sound quite intimate. In contrast to various Mundorf capacitors that tend to place the soundstage a little more to the back. That the K78-34 doesn't have heaps of outlined detail at the top end can be quite usefull at times, for example, if your system is a bit on the hot side of neutral the K78-34 should bring everything nicely back into balance.


----------



## John Massaria (Jun 10, 2020)

NOOB Crack owner just aquired!
Just got my Bottlehead Crack with Speedball and tube upgrades from a very cool engineer who built it- glorious sound on my HD600's and 100ohm Etymotic ER4s
Q:1 the tubes are what I think is a philips miniwatt ecc82 and Jan-CAHG 6080WA by Chatham Electronics - any thoughts on these tubes? I heard the Genalex Gold Lion E88cc 6922A is one of the end game tubes-would that even work in the crack? ? Thoughts on maybe explaining if I should try it or some other thoughts- much appreciated.I should mention there is zero noise or issues- I think I just answered my own question BUT would love to hear what experienced owners know of these tubes I am using... thanks again! 

Q:2
Also anyone ever check out this OTL company $600 bucks for a dual box set up (tube power supply + amp)

Technical Parameters:
Tube used : 6N8P, 6N13P, 5C4S
Frequency: + / -1dB 20Hz  ~ 100kHz
Distortion:  < = 2 % Output impedance: 8 to 600 ohm
Output power: 1w (100 ohm impedance load)
Output terminal: 6.3mm stereo jack
Input terminal: RCA jacks
Power supply: 220V or 120V (please choose) 150w
Case dimension: 7 kg

Anyone at all know of this company?


----------



## DenverW

John Massaria said:


> NOOB Crack owner just aquired!
> Just got my Bottlehead Crack with Speedball and tube upgrades from a very cool engineer who built it- glorious sound on my HD600's and 100ohm Etymotic ER4s
> Q:1 the tubes are what I think is a philips miniwatt ecc82 and Jan-CAHG 6080WA by Chatham Electronics - any thoughts on these tubes? I heard the Genalex Gold Lion E88cc 6922A is one of the end game tubes-would that even work in the crack? ? Thoughts on maybe explaining if I should try it or some other thoughts- much appreciated.I should mention there is zero noise or issues- I think I just answered my own question BUT would love to hear what experienced owners know of these tubes I am using... thanks again!
> 
> ...



hi, the e88cc is not a drop in equivalent for the crack.  I would peruse this thread, as well as the tube rollin* thread on the Bottlehead forums.  Congrats on your new crack!


----------



## John Massaria

DenverW said:


> hi, the e88cc is not a drop in equivalent for the crack.  I would peruse this thread, as well as the tube rollin* thread on the Bottlehead forums.  Congrats on your new crack!


I just figured it out about E88CC ! lol. Thanks for replying- hoping others can chime in- about other part of question... much appreciated


----------



## DenverW (Jun 10, 2020)

Off the top of my head, tubes that you can use with speedball would be 12au7 and ecc82 variants. 6sn7 and variants like the 7193 (half of a 6sn7), rj5 types, and 6f8g work fine with the proper adapters.  Tubes like E80CC (not e88!) and 12bh7 work as drop ins but work best with some small resistance changes inside.  Everyone has their favorites, and many prefer the 6sn7 type with the adapter.  Make sure to never put a 6sn7 into your power tube socket, even though it fits.

After all that, you know my favorite tubes with the crack?  12AU7 type.  The crack was designed with these in mind, and some just sing.  Siemens nickel plate (also called chrome or silver) is a great great tube for under $50.

As far as your other question, I've never seen the guys amps before and cant find any information on them.  He is possibly an ebay seller only.  Tube Lamps?  They look nice.


----------



## GreenNeedle (Jun 11, 2020)

I did say that the rosewood base for my crack would look much more lively and while I am not posting any pictures in this post I can say it is absolutely glowing while not finished.

I actually had to strip it back to bare wood because it turned out (I jammed it in for the earlier pictures) that the internal measurements of mine were very slightly smaller and thus the power connector and side capacitors were not fitting in very well.

So I routed out a bit around the rear and rear sides to negate that problem and then sanded the rest back.  I then bought a Danish Oil from someone on Easybay that is not a brand and it is WOW factor stuff.  Much thinner and goes on so nicely.  2 coats so far and it already beats the branded stuff.  I am positive this is going to look superb now 

In terms of the base plate, I have unsoldered the wires I need to, for me to be able to take the hardware off the plate and now have the plate back, bare and ready for enameling.  This will get some scuff sanding, then etch primer and finally enamelled in cream (spray.)  I actually had problems with the bell cover when i sprayed the hammerite on and (maybe sprayed too thick a coating) as it stayed gummy for ages, so I ended up taking that coat off, respraying and then putting it in my oven for an hour at 100C and it came out looking amazing and completely hard.

So I am intending to bake the cream enamel, maybe for less time but am hoping that the usual spray can "orange peel" effect remains rather than polishing it up to a smooth finish.  If it goes well I think I might do the chassis of my Trio KD1033 in the cream as well.

I should add it wasn't really that inspirational a choice.  It was when I was baking my bell cover the Oven communicated to me.  I have one of these ovens below and it lead me to a Garrard turntable that had been refinished in cream:






Should be able to put some "finished" pics up on Monday / Tuesday.  I say "finished" because you all like to add stuff and upgrade.  I am only intending to upgrade the volume pot the the TKD2511 and in a week or 2 add the speedball.


----------



## PsilocybinCube (Jun 12, 2020)

I'm sure that most of you have looked into the power cable from Bottlehead, but I had to add my two cents on their kit.

I purchased my BHC second-hand from @DenverW (who has helped me several times to troubleshoot and improve sound) and he said a couple of times that the first thing to do for the amp was to build the cord.  I was a little bit incredulous to be honest but decided to give it a whirl.

It was a fun and easy project.  Perhaps the best part was that my wife offered to do the braiding and she did a great job with it.  That may be the first time I've managed to wrangle her into this little audio hobby.

So, after plugging it in and A/B'ing it for two days, I have to say, I'm pretty surprised.  There are clear differences in the sound.  It would be easy to detect it in a blind test.  The sound is certainly clearer, the bass is definitely louder and clearer, and honestly the overall sound is much more smooth.

I'm using HD800 headphones (no mods, yet) and though I love the sound and extra dimension the headphones give with their large sound stage, I did feel they were a little bass-light.  The extra oomph to the bass has made quite a difference. 

Take it for what it's worth, but I think the power cable should be a must for BHC owners and now I am tempted to build them for other devices like my Topping DX7Pro.  I don't know that everything will experience the same benefits as an OTL amp, but the gains are pretty amazing for such a small investment.


----------



## GreenNeedle

PsilocybinCube said:


> I'm sure that most of you have looked into the power cable from Bottlehead, but I had to add my two cents on their kit.
> 
> I purchased my BHC second-hand from @DenverW (who has helped me several times to troubleshoot and improve sound) and he said a couple of times that the first thing to do for the amp was to build the cord.  I was a little bit incredulous to be honest but decided to give it a whirl.
> 
> ...



Do you have a link on how to make the power cable?


----------



## Bullpride

GreenNeedle said:


> Do you have a link on how to make the power cable?


The instructions are included when you purchase the materials from Bottlehead.


----------



## carlman14

GreenNeedle said:


> Do you have a link on how to make the power cable?



There's a link to the instructions on the power cord webpage: https://bottlehead.com/bottlehead-power-cord-kit-assembly/


----------



## PsilocybinCube

Bullpride said:


> The instructions are included when you purchase the materials from Bottlehead.


They actually didn't include instructions with mine.  There was a note to look at the instructions online and it stated that some of the parts included in the kit would look slightly different from what was sent.  

You could probably build your own power cable from the instructions online by purchasing the parts from a local electrical outlet.  That said, I didn't want to fry my BHC so I opted to pay a bit more and get it from Bottlehead!!!


----------



## DenverW

And you can support Bottlehead by getting it through them.  If you want to build a cord of your own later with what you learned that’s another matter.


----------



## Bullpride

DenverW said:


> And you can support Bottlehead by getting it through them.  If you want to build a cord of your own later with what you learned that’s another matter.


Yeah that's what I was getting at. I am all about supporting the fine folks at Bottlehead.  With out purchasing from them, they wouldn't continue to put out great kids and guides.


----------



## GreenNeedle

I don;t think I'll have any pictures by Monday.  Will wait a week for the enamel to dry but thought I would add this one.  Autistic people don't do things by halves.  I need that turntable to match the BH crack so that's been enamelled as well......and the new Danish Oil is darker than the one I used on the turntable plinth and my DIY receiver box so they need stripping to match the crack's wood colouring.  The crack is right at the back of this "family."

Pity that because the lighter colour was very much reminiscent of the sticky back vinyl coverings 70s equipment had.  Everything needs to match for me though 

The turntable enamel has a couple of "noggins" in the finish so will need to be wet sanded with P400 in a couple of days and have another go. A few "noggins" need to be lived with because every new coat seems to get some despite very careful tack cloth treatment prior to spraying.  These will likely rub out with nothing other than bare hands rather than needing sandpaper or anything else.

I've already widened the volume hole in the crack plate to accommodate the TKD 2CP 2511.


----------



## matti621

I'd like to have a taste of a tube amp. Which Chi-Fi should I try from aliexpress as a first dip?


----------



## Bullpride

matti621 said:


> I'd like to have a taste of a tube amp. Which Chi-Fi should I try from aliexpress as a first dip?


Pretty sure everyone here is going to suggest you build a Crack (Given this is the crack thread in the DIY forum).  

I know Josh Valour has done a video on tube preamps that can be had on Amazon for around $25. This would require you have a Solid State headphone amp already.


----------



## matti621 (Jun 15, 2020)

Bullpride said:


> Pretty sure everyone here is going to suggest you build a Crack (Given this is the crack thread in the DIY forum).
> 
> I know Josh Valour has done a video on tube preamps that can be had on Amazon for around $25. This would require you have a Solid State headphone amp already.


Let's put it this way. Which known design does it follow? They always resemble at least a class, sometimes almost copy amps from the 60's...  Some follow a seemingly simple desin (e.g. this Chinese amp) but it's hard for me to see from the pics.


----------



## PsilocybinCube

Bullpride said:


> Pretty sure everyone here is going to suggest you build a Crack (Given this is the crack thread in the DIY forum).
> 
> I know Josh Valour has done a video on tube preamps that can be had on Amazon for around $25. This would require you have a Solid State headphone amp already.


I'm pretty sure that if it doesn't have 'THX789' in the name of the amp, Josh doesn't like it.


----------



## matti621 (Jun 16, 2020)

What's the Crack's secret? It measures terribly according to this review. EDIT: link fixed


----------



## Bullpride

matti621 said:


> What's the Crack's secret? It measures terribly according to this review


That isn't a review of a Bottlehead Crack, so I am very confused by this post.


----------



## matti621

Bullpride said:


> That isn't a review of a Bottlehead Crack, so I am very confused by this post.


Link fixed.


----------



## Bullpride

matti621 said:


> Link fixed.



Maybe I don't see it, but where does he summarize that it does not measure well? I do not know enough about measurements to read/interpret them myself.


----------



## carlman14

matti621 said:


> What's the Crack's secret? It measures terribly according to this review. EDIT: link fixed





Bullpride said:


> Maybe I don't see it, but where does he summarize that it does not measure well? I do not know enough about measurements to read/interpret them myself.



I'm in the same boat. I don't necessarily know what good measurements look like... but he did have good things to say about it overall. Also, he's not using the speedball upgrade, which I'm sure would help the measurements a lot. I could be wrong... but don't tube amps generally measure pretty poorly (At least compared to solid state amps)? Tubes add distortion and coloration, so I imagine that no tube amp would measure that great.


----------



## Little Bear

I can't hear measurements.


----------



## chrisdrop (Jun 16, 2020)

... glow test passed. Part way through my 1st Crack build ...

Whenever I get time in the next few days, phase 1 should wrap up. Then, onto speedball..

Fun build project.


----------



## Bullpride

chrisdrop said:


> ... flow test passed. Part way through my 1st Crack build ...
> 
> Whenever I get time in the next few days, phase 1 should wrap up. Then, onto speedball..
> 
> Fun build project.


Nice looking build.  Spend a week or so with it stock, then consider adding the speedball.  That way you can train your ear to hear the difference. Just a thought.  I built mine about a month ago, added just the first small board.


----------



## PsilocybinCube (Jun 16, 2020)

I need to post a rant about why objective measurements of a subjective medium are silly...but - objectively - I don't have time right now.

Literally in every other area of life we match up products that work well together even though separately, they might not be the best standalone product.  Some things just have a synergy.

For instance, try throwing a bunch of CEOs together and ask them to start a business with no other employees.  Good luck finding a good receptionist from a bunch of CEOs...or a good CFO for that matter...or a good HR person...which you might want for a good business.  Audiophiles think things that do well separately should pair well, but that's not reality.

Or...for a more audiophile example.  Zeos reviewed the Verite (which I don't own so I might be out of my depth here) and paired the headphones with a bunch of crap amps.  He never paired it with the amps that everyone raves about using those headphones with.  He then said they were 'meh.'  Well, if I pair my HD800s with my SS amp, they are meh, too.  They are great with the BHC, though.  And likewise, if I paired some LCD-4s with the BHC, they'd sound like crap.  But they sound amazing on my SS amp.

So there you go.  I guess I did a mini rant.


----------



## cddc

chrisdrop said:


> ... glow test passed. Part way through my 1st Crack build ...
> 
> Whenever I get time in the next few days, phase 1 should wrap up. Then, onto speedball..
> 
> Fun build project.



Good progress...

I'd agree with @Bullpride, give it one or two weeks before adding the speedball upgrade.

I always regret that I did the speedball upgrade too fast, only 3 days after finishing the Crack. I vaguely recall the stock Crack has a very nice tubey sound. So spend some time with the stock Crack and get a good handle on how it sounds. Then you can hear what the Speedball upgrade brings.


----------



## cddc (Jul 23, 2020)

matti621 said:


> What's the Crack's secret? It measures terribly according to this review. EDIT: link fixed



I don't get it. Would you elaborate on how Crack measures terribly?

I read the article just a few mins ago, the OP actually says Crack sounds pretty good to his taste.

Now onto the measurements, if you're comparing Crack's measurements to other tube amps' measurements, it would be fair. But if you're comparing Crack's measurements to solid state amps' measurements, it would not be fair anymore, coz it's no longer an apple-to-apple comparison. We all know tube amps bring distortion compared to SS amps. So I don't think tube amps will measure as good as SS amps, but they do sound better than SS amps, at least to my ears.


----------



## Wes S

675 pages and still going. . .I think that speaks volumes for how famous the BHC is.  I hear over and over about how the BHC Speedball, sounds as good as or better than tube amps costing much more.  People can take there measurements, but who gives a crap when the amp sounds as good as it does.


----------



## CAJames

Little Bear said:


> I can't hear measurements.



I'm with you. No one gets a Stradivarius or a Chateau Margaux or a Rembrandt based on measurements, and I'm not getting an amp based on them either.


----------



## matti621 (Jun 17, 2020)

1. Is it true the Crack is extremely similar to the Van Waarde of headwize? A Single-Ended OTL Amplifier for Dynamic Headphones. – HeadWize Memorial
Is it original in design?
2. Is any SS amp similar to it _sonicaly_?


----------



## PsilocybinCube

matti621 said:


> 1. Is it true the Crack is extremely similar to the Van Waarde of headwize? A Single-Ended OTL Amplifier for Dynamic Headphones. – HeadWize Memorial
> Is it original in design?
> 2. Is any SS amp similar to it _sonicaly_?


I don't know an answer to question #1, but as someone who owns like 4 SS amps, I can say that the differences are subtle from SS.  That's not to say it's not noticeable, but everything in audiophilia is a game of inches.  

That said, what you have with a tube amp that you don't necessarily have with SS is the ability to tweak the sound in an incredibly short amount of time by simply changing a tube.  Also, there are some headphones that seem to have an odd synergy with tubes (think high impedance cans from German companies).  I don't think you really hear about that with SS amps.  And again, that's not to say I don't like SS, but tubes hooked me in a very short amount of time.  

As a musician I liken the difference between tube amps and SS to the difference between a digital synth vs. an analog synth.  A digital synth can usually do a lot more than an analog synth and do all of those things well.  But what an analog synth does well, it does really well, much better than the digital synth.  

Keep the SS amp for those Audeze headphones.  Buy the tubes for Sennheiser or Beyers or ZMFs (ooohhhh I want some ZMF headphones).


----------



## GreenNeedle

I notice on the BH page for the power cord assembly it looks like they are using the (quite) stiff PVC coated wire.  Does it matter if you use silicone coated wire of the same AWG?  I know it would be less inclined to stay as tightly twisted but in terms of sound?


----------



## chrisdrop

GreenNeedle said:


> I notice on the BH page for the power cord assembly it looks like they are using the (quite) stiff PVC coated wire.  Does it matter if you use silicone coated wire of the same AWG?  I know it would be less inclined to stay as tightly twisted but in terms of sound?


IMO unless you get a major power cable change/difference, there will be no difference. This is not a Bottlehead specific comment, but a universal amp comment.


----------



## GreenNeedle (Jul 1, 2020)

chrisdrop said:


> IMO unless you get a major power cable change/difference, there will be no difference. This is not a Bottlehead specific comment, but a universal amp comment.



Fun to make though and am currently using a cheap cable that came from an LED strip's power adaptor.  Either that one or a spare kettle lead I have.  Also it isn't really too expensive to make your own.  Not using a hospital grade one but a better made tighter MK plug.  The right angle IEC is also quite cool.

My point being that whether it makes any audible difference (true or false or placebo) with this amp the power cable is on view, it isn't in the back and unseen.

As a reference I am in the UK so we always hear about 240V but when measuring during the build it varied between 221V and 232V.  Pretty regular rather than big swings.

The wire question was more to do with the PVC vs silicon coating.  PVC holds a twist better but (for those that hear a difference) is PVC more desirable due to any "sonic" benefit or is it just because of the twisting ability or because it's the old trick that the dog remembers?


----------



## PsilocybinCube

GreenNeedle said:


> I notice on the BH page for the power cord assembly it looks like they are using the (quite) stiff PVC coated wire.  Does it matter if you use silicone coated wire of the same AWG?  I know it would be less inclined to stay as tightly twisted but in terms of sound?


Bottlehead mentions in the instructions that it's OK if the cables unwind a bit after twisting them up with the screwdriver.  You might just make the initial winding of the cables a bit tighter to compensate for additional unwinding occurring due to the cables being less stiff.  I think a proper braid also has a lot to do with it, and a silicone wire might braid easier.  
As to the sound benefits, as I posted before, I can hear it.  If it is placebo....give me some more placebo, please.


----------



## Little Bear (Jun 19, 2020)

PsilocybinCube said:


> As to the sound benefits, as I posted before, I can hear it.  If it is placebo....give me some more placebo, please.



That reminds me of a guy who made a similar comment on a different forum.  He was in an argument with others about whether he was wasting money on his $10k speaker cables.  His position was, what does it matter whether the difference he heard was real or not?  If he hears it, his outlay was justified even if it's just placebo effect.

I myself have never believed that any type of cables make a difference, and thus I've never heard a difference.  To hear it, you must _first believe it.  _Hearing occurs in the brain, not in the ears.


----------



## chrisdrop

GreenNeedle said:


> Fun to make though and am currently using a cheap cable that came from an LED strip's power adaptor.  Either that one or a spare kettle lead I have.  Also it isn't really to expensive to make your own.  Not using a hospital grade one but a better made tighter MK plug.  The right angle IEC is also quite cool.
> 
> My point being that whether it makes any audible difference (true or false or placebo) with this amp the power cable is on view, it isn't in the back and unseen.
> 
> ...


I am in the UK too. I have very variable power. I needed to get voltage regulation to get my main amp to be quiet in fact. I also built a reasonably posh power cable using Neotech UPOCC Copper & MS HD Power Parts. IMO it makes an audible difference, but it will set you back as much as a Crack.


----------



## PsilocybinCube (Jun 19, 2020)

Little Bear said:


> That reminds me of a guy who made a similar comment on a different forum.  He was in an argument with others about whether he was wasting money on his $10k speaker cables.  His position was, what does it matter whether the difference he heard was real or not?  If he hears it, his outlay was justified even if it's just placebo effect.
> 
> I myself have never believed that any type of cables make a difference, and thus I've never heard a difference.  To hear it, you must _first believe it.  _Hearing occurs in the brain, not in the ears.





Little Bear said:


> That reminds me of a guy who made a similar comment on a different forum.  He was in an argument with others about whether he was wasting money on his $10k speaker cables.  His position was, what does it matter whether the difference he heard was real or not?  If he hears it, his outlay was justified even if it's just placebo effect.
> 
> I myself have never believed that any type of cables make a difference, and thus I've never heard a difference.  To hear it, you must _first believe it.  _Hearing occurs in the brain, not in the ears.


I was being sarcastic about the placebo, I really can hear a difference and I do think it would be clear if A/B testing.
It doesn't seem to be a stretch to think that the clean delivery of power could have a material impact on a device relying on that power for its functions.
Anecdotally, when I purchased a power conditioner, my gaming monitor's image got better.  Prior to the power conditioner, I had horizontal faint lines that would make their way up the screen.  Now, that is not an issue.  It's a 3440x1440p high refresh IPS monitor with G-Sync if that matters.  That example showed me that dirty power can hurt performance of a piece of electronics.
The power conditioner also helped to clean up some of the noise that I was hearing in my BHC.

I've never been one to believe in cables and always thought it was BS, but after so many positive reviews of the power cord, I can say that it does make a material difference.  I'd imagine an electrical engineer somewhere could probably elaborate on why superior power delivery to an electronic device may improve performance.


----------



## Tom-s

I'm not that good with cables. But i do try tube rolling.

Meet the grandparents of 12AU7, the first indirectly heated medium mu triodes, type 27.

Shown here is a mesh plate version -227- labeled Sonatron (a 1920's company).




Based on build/labeling/date code; this pair was made by Sylvania.
This makes it no surprise that these sound close to their Sylvania type 37 brothers i've tried before (similar, but with more Crack friendly 6.3V heaters).
The sound is open and airy, clear, detailed but with a touch of floppy bass. Not as good a soundstage as the 37 version but I do like them!
I have to investigate deeper to find out if AC vs DC heaters influence the soundstage in any way (this could explain the difference i'm hearing).

Don't use these in a standard Crack. With a 2.5V heater voltage (and 1A current), they won't work.
I'm using them with an external power supply.
To get most out of this, i've added a switch in my existing @Deyan adapter.
This makes it possible to switch from the internal to external heater supply and back.


----------



## cddc (Oct 16, 2020)

Those 37's look great!


----------



## chrisdrop

chrisdrop said:


> ... glow test passed. Part way through my 1st Crack build ...
> 
> Whenever I get time in the next few days, phase 1 should wrap up. Then, onto speedball..
> 
> Fun build project.


Well, it works. I have plugged in my cheap "sacrificial headphones" and they are good to go. I had to tidy up one solder-point at the point of voltage testing, but all well otherwise. Eventually I'll get the courage to plug in more expensive headphones (Eikons will start).  I have plenty of nice tubes. I have no illusion that the Crack will be able to coexist with my Glenn amp, but it was a very fun project. Perhaps I'll take it to my office? Not sure yet!



 Inside


----------



## PsilocybinCube

chrisdrop said:


> Well, it works. I have plugged in my cheap "sacrificial headphones" and they are good to go. I had to tidy up one solder-point at the point of voltage testing, but all well otherwise. Eventually I'll get the courage to plug in more expensive headphones (Eikons will start).  I have plenty of nice tubes. I have no illusion that the Crack will be able to coexist with my Glenn amp, but it was a very fun project. Perhaps I'll take it to my office? Not sure yet!
> 
> Inside


Congrats.  And yes!  Take it to the office!  I'm going to build a Mainline or Crack for my office, too!  

Love the paint color, too.


----------



## matti621 (Jun 25, 2020)

Which SS amp made you smile as much as the BHC?
Are they really comparable? According to one of the first matches in Google:


> In the end, its all about your investment. Tubes are hotter, and the power they make watt for watt is more expensive.
> 
> If the closest you can get to real music is your goal, tubes are the way to go. If its anything else (sound pressure, low heat), probably solid state.
> 
> ...


----------



## PsilocybinCube

matti621 said:


> Which SS amp made you smile as much as the BHC?
> Are they really comparable? According to one of the first matches in Google:


I recently found a great deal on the HDVA 600 from Sennheiser that I'm waiting on.  I will let you know how it acts with the HD650 and HD800 once I've tried it!!!
I'm in love with my BHC and great tubes. The HDVA will have a long road to climb to beat out the world of tubes...


----------



## raindownthunda

chrisdrop said:


> Well, it works. I have plugged in my cheap "sacrificial headphones" and they are good to go. I had to tidy up one solder-point at the point of voltage testing, but all well otherwise. Eventually I'll get the courage to plug in more expensive headphones (Eikons will start).  I have plenty of nice tubes. I have no illusion that the Crack will be able to coexist with my Glenn amp, but it was a very fun project. Perhaps I'll take it to my office? Not sure yet!
> 
> Inside



Congrats!! Nothing like that first listen feeling to confirm it works!

I'm very interested in hearing how your Glenn OTL compares to the BHC. I built my BHC at the same time I put a deposit down for a Glenn amp and I can't imagine any amp sounding better than the BHC  Are you planning on installing the Speedball at some point?


----------



## CAJames

chrisdrop said:


> Well, it works. I have plugged in my cheap "sacrificial headphones" and they are good to go. I had to tidy up one solder-point at the point of voltage testing, but all well otherwise. Eventually I'll get the courage to plug in more expensive headphones (Eikons will start).  I have plenty of nice tubes. I have no illusion that the Crack will be able to coexist with my Glenn amp, but it was a very fun project. Perhaps I'll take it to my office? Not sure yet!
> 
> Inside



Nice work! Around the office I refer to myself as a "software guy" and really admire those of you who are handy with a soldering iron and can turn out such classy work.


----------



## attmci

chrisdrop said:


> Well, it works. I have plugged in my cheap "sacrificial headphones" and they are good to go. I had to tidy up one solder-point at the point of voltage testing, but all well otherwise. Eventually I'll get the courage to plug in more expensive headphones (Eikons will start).  I have plenty of nice tubes. I have no illusion that the Crack will be able to coexist with my Glenn amp, but it was a very fun project. Perhaps I'll take it to my office? Not sure yet!
> 
> Inside


Glad to learn you have a Crack too. 

I haven't turned on my Crack for more than a year. But I have no plan to get rid of it.


----------



## GreenNeedle

Little Bear said:


> That reminds me of a guy who made a similar comment on a different forum.  He was in an argument with others about whether he was wasting money on his $10k speaker cables.  His position was, what does it matter whether the difference he heard was real or not?  If he hears it, his outlay was justified even if it's just placebo effect.
> 
> I myself have never believed that any type of cables make a difference, and thus I've never heard a difference.  To hear it, you must _first believe it.  _Hearing occurs in the brain, not in the ears.



When I got my turntable (upon returning to vinyl) I had trouble with buzzing from the stock cable.  Replaced it with some spare Digital Coax cables with the RCA ends and buzzing gone.  Simple and crude example I know but that extra shielding worked.


----------



## BottleFred

Hi there,
First of all, Dutch chap here so (please) excuse the grammar.

Newbie here from The Netherlands, 40ish Sound-Engineer, since fall ’19 very enthousiastic about the combi BottleHead Crack & AKG K340 both introduced by Tom-s (he actually bought my two 2xCV4079 to 6080 adapters which unfortunately were not working in my SpeakerAmp (DIY). A few months later I ordered another from @Deyan  to put in my freshly bought secondhand Crack.

So now powered with a lot of info and knowledge from Tom-s I’m cruising trough Tubie Wonderland to get my kicks and a lot of musical enjoyment!

This will be a review of some 6C5G tubes. Succesor of the 76 tube (27-37-56-76-6C5 etc).
Just for all of you who are interested in something else than 12AU7’s...
These tubes, supplied by Tom-s, will be put on pole position in a BottleHead Crack, normally filled with an ECC82 of some sort. Using an adapter (home-made) and Speedball.
Rest of the line-up:
-Source: Qobuz 16/44.1
-Streamer: M1CLIC Musical Fidelity (also used as pre-amp)
-Interconnect cable: SharkWire
-Headphone-amp: BottleHead Crack with 2x GEC CV4079 as output tube.
(Bottlehead upgrades: Speedball, Vishay 100uF MKP output caps, Choke, Cree Diodes, removed volumepot, removed RCA chassis and hardwired ‘interconnects’ from SharkWire, diy powerlead (from Linn K400).
-Headphone: AKG K340 (fed by Mogami StarQuad cable).

Yesterday I’ve rolled some 37-76 and 6J5G tubes, the musical favorite was Adzam 76.
So this tube will act as ‘reference’-tube.

Chosen music:
-Trondheimsolistene - Magnificat IV. Et misericordia
-Darondo - Didn’t I (Listen to my song: The Music City Session)
-Robert Miles - Loom (Miles Gurtu) ---with Trilok Gurtu---

Tubes:
-76: Adzam 
-6C5G: Brimar, Sylvania, Fivre, RCA, KenRad

Starting of with Adzam’s 76 conclusion:
Very nice tube, neutral but with enough character to be exciting.
Warm sounding tube, full upperbass but a little recessed lowbass/sub, beautiful mids (very nice atmosphere and acoustics), somewhat recessed highs but very pleasing and with enough detail. Spacious presentation, pleasant unobtrusive sound.
Spoiler alert: this tube will actually fall into second place...

5. Brimar
Slightly narrow presentation, highmids-orientated therefore a little harsh sounding. ill low definition due to muddy lows. No common space/no interaction, seems disjointed. Pale, no layer definition.

4. Sylvania
Direct sounding tube. Cloudy due to strong midlows/lows. Feeling of a “digital cut-up” signal, due to little cohesion/transparency/dynamics. Absence of detailed highs, obscured. Restless image.

3. Fivre:
Beautiful acoustics, beautiful mids. A little harshness also caused by recessed lows, therefore little detail in bass/upper bass. Beautiful depth, good natural presentation.

2. RCA:
Medium direct, spatial presentation. Beautiful placement of instruments. A full sounding tube. Slightly withdrawn mid layer. Fine interplay, beautiful instrument separation. Slightly cloudy due to the abundance of bass/midbass. Musically tube.

1. Ken-Rad:
Unfortunately both tubes had a little humm (one more than the other).
Beautiful natural image, very good placement, clear acoustics. Beautiful bottom-end of voices and wooden instruments. Slightly unclear retracted basses. Great presentation. Musical! SPACE. Detailed upper bass, dry, involved tight sound. More details than all the others.

After this evenings runs I actually could live with any of them, they all outperform most 12AU7’s, and the top two ’ll even pale the best of them (and yess I’ve heard them).
The remarks are pointed out with very criticized “Engineers Ears”, and are sometimes a little over-exaggerated, but are used to explane the impressions of the tubes characters...

I'll find a way to add photo's later on...


----------



## DenverW

Had some time during the day so I installed the cree diode upgrade.  For the cost (about 15 total) and the ease of install (4 wires total) I would say this is an excellent upgrade.  Improved low end is the most noticable change that i'm hearing right now.

I'm still waiting on a pair of 100uf kzk white line capacitors from russia (2 months shipping now, and still waiting) so I may end up being the first person to upgrade everything else BEFORE the output caps.  After I do some more listening the next step is to upgrade two ps caps to 470uf, and the final ps cap to a panasonic ezp with some bypass caps.  Sound is just getting better and better.


----------



## cebuboy

KZK caps are good for the money. Running out of space for a choke.


----------



## cddc

DenverW said:


> Had some time during the day so I installed the cree diode upgrade.  For the cost (about 15 total) and the ease of install (4 wires total) I would say this is an excellent upgrade.  Improved low end is the most noticable change that i'm hearing right now.
> 
> I'm still waiting on a pair of 100uf kzk white line capacitors from russia (2 months shipping now, and still waiting) so I may end up being the first person to upgrade everything else BEFORE the output caps.  After I do some more listening the next step is to upgrade two ps caps to 470uf, and the final ps cap to a panasonic ezp with some bypass caps.  Sound is just getting better and better.




Lots of mods...

How do you install these caps, just add them in parallel to the original ones?


----------



## DenverW

cddc said:


> Lots of mods...
> 
> How do you install these caps, just add them in parallel to the original ones?



They're just direct replacements for the original caps.  If I do a bypass that would be in parallel.


----------



## Wes S

This tube combo is legit!  

Bendix 6080WB & Sylvania 6SN7W


----------



## Bullpride

I just picked up a Tung Sol Chatham 6080 and a Tun Sol 12AU7 Black Glass from VacuumTubes.net.  I've only spent a few hours with them, but liking them so far.


----------



## cddc

Bullpride said:


> I just picked up a Tung Sol Chatham 6080 and a Tun Sol 12AU7 Black Glass from VacuumTubes.net.  I've only spent a few hours with them, but liking them so far.



VacuumTubes.net sells used tubes as NOS tubes, just make sure you got the good ones.


----------



## cddc

Wes S said:


> This tube combo is legit!
> 
> Bendix 6080WB & Sylvania 6SN7W




These Metallica tubes look gorgeous


----------



## cddc

DenverW said:


> They're just direct replacements for the original caps.  If I do a bypass that would be in parallel.




Cool!

How do you choose the caps, the bigger the better, or there are some specs that you have to follow?


----------



## Bullpride

cddc said:


> VacuumTubes.net sells used tubes as NOS tubes, just make sure you got the good ones.


How do I tell?

I think I may have gotten used one...?


----------



## Wes S

cddc said:


> These Metallica tubes look gorgeous


They sound even better than they look.  This tube combo is incredible, and has a huge sound stage, killer transparency, and punch you can feel. This is the kind of sound that makes the headphones disappear like you are there and everything sounds so big, natural and lifelike I can't stop listening. All this magic happens, while still being smooth and fatigue free. This is the best I have ever heard, both my BHC and ZMF Atticus sound. Freaking perfection!


----------



## cddc

Bullpride said:


> How do I tell?
> 
> I think I may have gotten used one...?




Buying a tube tester would be too costly an option to just verify a few tubes. Send them to a friend with some tester if you can, or there is nothing really you can do.

Buy tubes next time from some reputable sellers...the most important thing - don't buy tubes without measurements.


----------



## Wes S

Sorry double post.


----------



## DenverW

cddc said:


> Cool!
> 
> How do you choose the caps, the bigger the better, or there are some specs that you have to follow?



For the crack, I took into consideration the cost, reviews of the capacitor, and the size.  Since the output caps are 100uf (although you can go down a but, though that starts getting bass roll off) they're pretty huge, and require some creative mounting options in the base.  I ended up going with the kzk white line tubes because they fit, were reviewed well, and were pretty cheap.  Since it doesnt look like i'll be getting those, I'll probably switch to the panasonic ezp line, because they're small, easy to get, and inexpensive.  The mundorf line is pretty popular, but the cost is pretty high.  If I was going to spend over 100 for a component, I figure I should probably just sell the amp and order a crackatwoa instead.

For my mainline I ordered Auricap XO caps, and bypassed them with really inexpensive FT-3 russian teflons.  I didnt mind spending a bit more here, as this is already my endgame amp.


----------



## Bullpride

cddc said:


> Buying a tube tester would be too costly an option to just verify a few tubes. Send them to a friend with some tester if you can, or there is nothing really you can do.
> 
> Buy tubes next time from some reputable sellers...the most important thing - don't buy tubes without measurements.


 These appear to have measurements, though I have no idea if they are legit or good.


----------



## cddc

Bullpride said:


> These appear to have measurements, though I have no idea if they are legit or good.




The specs for 12AU7 is 2200 micromhos, so you have (1465, 1483) / 2200 = (67%,  67%) of 100% NOS

The specs for 6080 is 7 mA/V,  so you have (5.55, 5.90) / 7 = (79%, 84%) of 100% NOS


----------



## Bullpride

cddc said:


> The specs for 12AU7 is 2200 micromhos, so you have (1465, 1483) / 2200 = (67%,  67%) of 100% NOS
> 
> The specs for 6080 is 7 mA/V,  so you have (5.55, 5.90) / 7 = (79%, 84%) of 100% NOS


 So I got used and not NOS.  When I email him, I don't believe I mentioned I wanted NOS specifically. That's on me and not him.


----------



## attmci (Jul 10, 2020)

Bullpride said:


> These appear to have measurements, though I have no idea if they are legit or good.


That's a 12AX7 according to the label on the box.It's amplification factor (100) is 5 time more than that of a 12au7 (~20).


----------



## cddc

He bought a Tung Sol 12AU7 Black Glass, I guess the box was initially used for 12AX7, but now it's used for his 12AU7.

The 12AU7 is very weak for sure, only 67%.


----------



## attmci (Jul 10, 2020)

cddc said:


> He bought a Tung Sol 12AU7 Black Glass, I guess the box was initially used for 12AX7, but now it's used for his 12AU7.
> 
> The 12AU7 is very weak for sure, only 67%.


I love/enjoy to use the BG TS 12au7 tube on my Crack.Especially with a 5998.


----------



## cddc

DenverW said:


> For the crack, I took into consideration the cost, reviews of the capacitor, and the size.  Since the output caps are 100uf (although you can go down a but, though that starts getting bass roll off) they're pretty huge, and require some creative mounting options in the base.  I ended up going with the kzk white line tubes because they fit, were reviewed well, and were pretty cheap.  Since it doesnt look like i'll be getting those, I'll probably switch to the panasonic ezp line, because they're small, easy to get, and inexpensive.  The mundorf line is pretty popular, but the cost is pretty high.  If I was going to spend over 100 for a component, I figure I should probably just sell the amp and order a crackatwoa instead.
> 
> For my mainline I ordered Auricap XO caps, and bypassed them with really inexpensive FT-3 russian teflons.  I didnt mind spending a bit more here, as this is already my endgame amp.




Oh boy...you are really into this DIY hobby    not too long ago you built a Crack, now you are building a Mainline....congrats!

Crack uses two 100uf caps for output, and three 220uf caps for its PS. The 100uf kzk white line cap is already huge from @cebuboy 's photo on previous page, is the 220 uf cap even bigger and impossible to fit in the case?

Also, why he added two additional 1 uf caps to the output (1 uf bypassed by 100 uf?), are they too small?


----------



## DenverW

cddc said:


> Oh boy...you are really into this DIY hobby    not too long ago you built a Crack, now you are building a Mainline....congrats!
> 
> Crack uses two 100uf caps for output, and three 220uf caps for its PS. The 100uf kzk white line cap is already huge from @cebuboy 's photo on previous page, is the 220 uf cap even bigger and impossible to fit in the case?
> 
> Also, why he added two additional 1 uf caps to the output (1 uf bypassed by 100 uf?), are they too small?



So I actually didnt build my mainline, I got it from another nice head fier.  I did replace the output caps inside, however.

For the 220uf PS caps in the crack, I replaced two with higher 470uf non film caps, so they're a bit bigger, but not anywhere near the size of the film caps.  The final 220uf PS cap is replaced with a 100uf panasonic film cap, and bypassed with a 1uf mundorf and a .01uf audyn true copper.  It was overall inexpensive, as the most expensive caps are the lowest uf.  Since I have a choke installed I was able to lower the uf of the final PS cap to 100 with no problems.  I suppose I could have replaced all the PS caps, but really only the final one should matter.  Its fun, I must say.  I enjoy the tinkering, and it keeps me from tube rolling as much since I'm focused on other components!


----------



## cebuboy

cddc said:


> Oh boy...you are really into this DIY hobby    not too long ago you built a Crack, now you are building a Mainline....congrats!
> 
> Crack uses two 100uf caps for output, and three 220uf caps for its PS. The 100uf kzk white line cap is already huge from @cebuboy 's photo on previous page, is the 220 uf cap even bigger and impossible to fit in the case?
> 
> Also, why he added two additional 1 uf caps to the output (1 uf bypassed by 100 uf?), are they too small?



you are correct, the 1uf orange lines are bypass for the 100uf output caps.

fitting in a 220uf film cap is kinda not cost effective anymore, so I just bypassed it with a 2.2uf.

getting crowded in there, maybe a cree diode and possibly a choke later if it can fit.


----------



## evonimos (Jul 11, 2020)

In a similar OTL design, I increased capacitance as much as space allowed for it.
I replaced the 2x100uF(200uF total) electrolytics with 2x680uF(1360uF total), per channel.

So if your enclosure allows for it, go for an array of large value electrolytics, in parallel with smaller value film capacitors and/or ex-soviet PIO.


----------



## Bullpride

cddc said:


> He bought a Tung Sol 12AU7 Black Glass, I guess the box was initially used for 12AX7, but now it's used for his 12AU7.
> 
> The 12AU7 is very weak for sure, only 67%.


Correct, I believe he reused boxes that did not initially come with the tubes. I bought.  

Is it possible the top measurements are 9s and not 4s (1965/1983 vs 1465/1483) though its hard to tell.  Lesson learned though. Buy NOS instead of used. 

I paid 15 for the 6080 and 40 for the 12AU7 black glass.


----------



## Wes S

Bullpride said:


> Correct, I believe he reused boxes that did not initially come with the tubes. I bought.
> 
> Is it possible the top measurements are 9s and not 4s (1965/1983 vs 1465/1483) though its hard to tell.  Lesson learned though. Buy NOS instead of used.
> 
> I paid 15 for the 6080 and 40 for the 12AU7 black glass.


There is nothing wrong with buying used tubes, as long as you know that when making the purchase and aren't paying NOS prices.  Some of my best tubes were bought used.


----------



## PsilocybinCube

Hey everyone, odd question, but where do





DenverW said:


> So I actually didnt build my mainline, I got it from another nice head fier.  I did replace the output caps inside, however.
> 
> For the 220uf PS caps in the crack, I replaced two with higher 470uf non film caps, so they're a bit bigger, but not anywhere near the size of the film caps.  The final 220uf PS cap is replaced with a 100uf panasonic film cap, and bypassed with a 1uf mundorf and a .01uf audyn true copper.  It was overall inexpensive, as the most expensive caps are the lowest uf.  Since I have a choke installed I was able to lower the uf of the final PS cap to 100 with no problems.  I suppose I could have replaced all the PS caps, but really only the final one should matter.  Its fun, I must say.  I enjoy the tinkering, and it keeps me from tube rolling as much since I'm focused on other components!


Once you get done tricking out that Crack, just let me know if you want to let it go for cheap so you can build another one 😉

When I return to the office, I will need another amp for listening at work.


----------



## cddc

DenverW said:


> So I actually didnt build my mainline, I got it from another nice head fier.  I did replace the output caps inside, however.
> 
> For the 220uf PS caps in the crack, I replaced two with higher 470uf non film caps, so they're a bit bigger, but not anywhere near the size of the film caps.  The final 220uf PS cap is replaced with a 100uf panasonic film cap, and bypassed with a 1uf mundorf and a .01uf audyn true copper.  It was overall inexpensive, as the most expensive caps are the lowest uf.  Since I have a choke installed I was able to lower the uf of the final PS cap to 100 with no problems.  I suppose I could have replaced all the PS caps, but really only the final one should matter.  Its fun, I must say.  I enjoy the tinkering, and it keeps me from tube rolling as much since I'm focused on other components!



Nice find on the Mainline. It is supposed to be a great amp for both low-Z and high-Z headphones.

Obviously lots of mods and considerations involved here. They are much more difficult than swapping tubes, and very likely will bring more sonic improvements.

Is there any benefit to bypass the large caps with smaller ones, like the 1 uf and 0.01 uf caps you and cebuboy used?


----------



## cddc

cebuboy said:


> you are correct, the 1uf orange lines are bypass for the 100uf output caps.
> 
> fitting in a 220uf film cap is kinda not cost effective anymore, so I just bypassed it with a 2.2uf.
> 
> getting crowded in there, maybe a cree diode and possibly a choke later if it can fit.




Getting crowded indeed. Cree should have no problem to fit in there. For the choke, I saw lots of people installed it at the place where you installed your 2.2 uf cap. You can possibly place the choke between the headphone jack and 100uf cap, or switch position with the 2.2uf cap, it won't be an easy task with the stock case anyway


----------



## cddc (Jul 17, 2020)

evonimos said:


> In a similar OTL design, I increased capacitance as much as space allowed for it.
> I replaced the 2x100uF(200uF total) electrolytics with 2x680uF(1360uF total), per channel.
> 
> So if your enclosure allows for it, go for an array of large value electrolytics, in parallel with smaller value film capacitors and/or ex-soviet PIO.




Is there any risk if you increase the capacitance too much or bypass the stock caps with too many caps?

I can see the danger of using caps (relative to other electronic elements). For example, you have to carefully discharge the large caps before making any measurements.

I also possibly read someone blew his headphones due to cap discharging when he turned off the amp or unplugged his headphones (long time ago, so can't remember exactly), after he installed some large caps.


----------



## evonimos (Jul 11, 2020)

cddc said:


> Is there any risk if you increase the capacitance too much or bypass the stock caps with too many caps?
> 
> I can see the damage of using caps (relative to other electronic elements). For example, you have to carefully discharge the large caps before making any measurements.
> 
> I also possibly read someone blew his headphones due to cap discharging when he turned off the amp or unplugged his headphones (long time ago, so can't remember exactly), after he installed some large caps.



Tube circuits are usually high voltage, so one has to be extremely cautious when working around them.
Always discharge capacitors prior to doing any kind of work. Safety first!

Even a smaller charged cap can provide a generous and dangerous shock if not handled carefully.
The last thing we want is dead DIYers on top of their tube amps!

So with that aside, the larger capacitance can be beneficial if in the right place.
OTL designs usually have an array of coupling caps in series to the signal at the output, followed by a resistor to ground. They are used to block DC voltage reaching your cans, allowing only the signal to pass (AC). They also form a CR filter (high pass) in conjunction with the following resistor and the load (impedance) of your cans.

In my case the resistor to ground is a 10kΩ + 50Ω (HD599 cans) which equals to something less than 50Ω total. That means that if i increase  capacitance i achieve a lower high pass frequency. Lower is better than higher in my opinion.

Since the larger capacitance calls for electrolytics, it is also a good idea to use some better caps in parallel.
Film and/or PIO cap are good enough for that and offer a nice improvement.


----------



## Paladin79

Early stages of some cabinet design, lots of sanding to be done. Honey locust with purple heart splines.


----------



## Wes S

Paladin79 said:


> Early stages of some cabinet design, lots of sanding to be done. Honey locust with purple heart splines.


Gnarly and very cool grains on both panels!


----------



## raindownthunda (Jul 14, 2020)

12au7 -> 2x 6j5 adapter from @Deyan arrived!

Initial impressions using my Bottlehead Crack w/ SB, Chatham 6080WB power tube, ZMF Aeolus, and Modi 3...

First pair I tried was a rusty pair of metal Ken Rad 6j5 tubes. These are the cheapest and ugliest 6j5 tubes I own ($15/pair), but work great! These deliver some serious bass.


Next up, a pair of metal RCA 6j5 (one is branded HP). Wait.. these sound fantastic! Definitely more detailed and spacious than the KR's. Despite these being very warm drivers + warm power tube + warm headphones, the end result is extremely pleasing to my ears, but may be too warm for some. I expect these would sound great with the Tung-Sol 5998 or WE421a (need to test to confirm). I was surprised with how well these sound for the price (~$20/pair).


I have a couple more pairs of 6j5's to roll through before moving on to the 6c5 variants. Looking forward to see how the MOV/GEC 6j5's and Fivre 6c5's compare.


----------



## Paladin79

Wes S said:


> Gnarly and very cool grains on both panels!


That was from the same board but patterns vary greatly.


----------



## DenverW

raindownthunda said:


> 12au7 -> 2x 6j5 adapter from @Deyan arrived!
> 
> Initial impressions using my Bottlehead Crack w/ SB, Chatham 6080WB power tube, ZMF Aeolus, and Modi 3...
> 
> ...



Welcome to the world of frankentubes!  I'm a big fan of alternate tube rolling, having tried 6j5, 6f8g, 6sn7, and cv6/e1148.


----------



## Paladin79

DenverW said:


> Welcome to the world of frankentubes!  I'm a big fan of alternate tube rolling, having tried 6j5, 6f8g, 6sn7, and cv6/e1148.


Any 7A4’s?


----------



## DenverW

Paladin79 said:


> Any 7A4’s?



ohhhhh you tease!  Not yet


----------



## Paladin79

DenverW said:


> ohhhhh you tease!  Not yet


There are plenty of them on Ebay for little money but often used and you would have to trust the seller.

There are some NOS if you watch for them, the military version, VT 192's, here is a single.

https://www.ebay.com/itm/U-S-Army-S...367309?hash=item3b4659e68d:g:6mUAAOSwIAxeqeso


----------



## Wes S (Jul 15, 2020)

raindownthunda said:


> 12au7 -> 2x 6j5 adapter from @Deyan arrived!
> 
> Initial impressions using my Bottlehead Crack w/ SB, Chatham 6080WB power tube, ZMF Aeolus, and Modi 3...
> 
> ...


Nice man, I bet those sound killer!  I just would have a hard time not seeing the glass, as seeing the red glow, and internals is a big part of the experience for me, but I may have to give that a shot.  I would love to know how much different the 6J5's sound to a singe 6SN7.  I am especially interested in comparing some 6J5's to my Tung Sol BGRP 6SN7GT and Sylvania 6SN7W, as those 2 tubes are insane.


----------



## Paladin79

Wes S said:


> Nice man, I bet those sound killer!  I just would have a hard time not seeing the glass, as seeing the red glow, and internals is a big part of the experience for me, but I may have to give that a shot.  I would love to know how much different the 6J5's sound to a singe 6SN7.  I am especially interested in comparing some 6J5's to my Tung Sol BGRP 6SN7GT and Sylvania 6SN7W, as those 2 tubes are insane.


I have experimented with most all of the variations of single triode 6sn7 equivalents and some sound pretty good, especially channel separation but a well shielded dual triode can get pretty close to that separation. I personally prefer the two tubes you mentioned but one of my favorite 6j5 Sylvaina three hole black plates can get awfully close to the 6sn7W IMHO.


----------



## Wes S

Paladin79 said:


> I have experimented with most all of the variations of single triode 6sn7 equivalents and some sound pretty good, especially channel separation but a well shielded dual triode can get pretty close to that separation. I personally prefer the two tubes you mentioned but one of my favorite 6j5 Sylvaina three hole black plates can get awfully close to the 6sn7W IMHO.


Cool!  Thanks for talking me off the ledge, and I think I will just stay with my 6SN7's.


----------



## Paladin79

Wes S said:


> Cool!  Thanks for talking me off the ledge, and I think I will just stay with my 6SN7's.


This is just one opinion, and we have some pretty high end 6j5's in an upcoming blind listening, Marconi and GEC are among those. There will be 50 people giving opinions then and I tend to trust the average more than what I might offer myself.


----------



## Wes S

Paladin79 said:


> This is just one opinion, and we have some pretty high end 6j5's in an upcoming blind listening, Marconi and GEC are among those. There will be 50 people giving opinions then and I tend to trust the average more than what I might offer myself.


Cool!  I still can't get past the metal and no visible glass at the moment, but hey if they sound better maybe I can eventually.


----------



## Paladin79

Wes S said:


> Cool!  I still can't get past the metal and no visible glass at the moment, but hey if they sound better maybe I can eventually.


There are still plenty of metal can RCA's out there as well for little money. I have some of those NOS around here somewhere.


----------



## PsilocybinCube

Has anyone tried the 12BH7A tube?  I'd like to try rolling the tube and when I look on this link it says it is compatible with the BHC:    https://forum.bottlehead.com/index.php?topic=663.0

Thoughts?


----------



## CAJames

Wes S said:


> Cool!  I still can't get past the metal and no visible glass at the moment, but hey if they sound better maybe I can eventually.



Yes, under no circumstances should you go out and buy these cheap, great sounding tubes and run up the price!


----------



## Wes S (Jul 16, 2020)

CAJames said:


> Yes, under no circumstances should you go out and buy these cheap, great sounding tubes and run up the price!


No worries, they are safe from me, as I am happy with this tube combo.


----------



## raindownthunda (Jul 17, 2020)

Wes S said:


> Nice man, I bet those sound killer!  I just would have a hard time not seeing the glass, as seeing the red glow, and internals is a big part of the experience for me, but I may have to give that a shot.  I would love to know how much different the 6J5's sound to a singe 6SN7.  I am especially interested in comparing some 6J5's to my Tung Sol BGRP 6SN7GT and Sylvania 6SN7W, as those 2 tubes are insane.



I don't have any 6sn7 to compare to personally, but the consensus on the Glenn thread seems to be that 2x 6j5 have sonic advantages over the single 6sn7 counterparts. @L0rdGwyn compared 2x Tung Sol 6j5 to the Tung Sol 6sn7 BGRP here: https://www.head-fi.org/threads/2359glenn-studio.600110/page-1958#post-15152863

The Glenn amp I am getting will have 2x 6j5 sockets (instead of a 6sn7 socket). They definitely don't t look as elegant in the BHC with the towering adapter


----------



## raindownthunda

Does anyone know if dual 6n7 tubes will work with the bottlehead crack?


----------



## L0rdGwyn

@raindownthunda yes from all of my listening tests on the 2359glenn thread, the 6J5 holds a sonic advantage over the 6SN7.  After modifying my GOTL to take these tubes and ranting about them enough, everyone is now buying up the 6J5  get them while they are still relatively cheap, hopefully commercial tube amp manufacturers don't catch on, otherwise prices and demand will skyrocket, which has been the case with the 6SN7.  I will be very disappointed if that happens.


----------



## CAJames

L0rdGwyn said:


> @raindownthunda yes from all of my listening tests on the 2359glenn thread, the 6J5 holds a sonic advantage over the 6SN7.  After modifying my GOTL to take these tubes and ranting about them enough, everyone is now buying up the 6J5  get them while they are still relatively cheap, hopefully commercial tube amp manufacturers don't catch on, otherwise prices and demand will skyrocket, which has been the case with the 6SN7.  I will be very disappointed if that happens.



If that happens there will always be the 7A4.


----------



## L0rdGwyn

CAJames said:


> If that happens there will always be the 7A4.



That is true!  Not as much variety as the 6J5 family, but they sure are cheap.


----------



## Wes S (Jul 18, 2020)

raindownthunda said:


> I don't have any 6sn7 to compare to personally, but the consensus on the Glenn thread seems to be that 2x 6j5 have sonic advantages over the single 6sn7 counterparts. @L0rdGwyn compared 2x Tung Sol 6j5 to the Tung Sol 6sn7 BGRP here: https://www.head-fi.org/threads/2359glenn-studio.600110/page-1958#post-15152863
> 
> The Glenn amp I am getting will have 2x 6j5 sockets (instead of a 6sn7 socket). They definitely don't t look as elegant in the BHC with the towering adapter


Yes sir!  I know all about those tubes and the Glenn.  I was just giving you a hard time, because it looks funny, but I am sure they will sound insane in your Glenn.    I think I have quite a bit different taste in sound sigs than @L0rdGwyn, but I am sure many have similar taste as well.  I wonder if there is an equivalent 6J5 to the Sylvania 6N7W metal base, like there seems to be for the Tung Sol BGRP?  The Tung Sol BGRP 6SN7 is killer, but the Sylvania W metal base is on another level.


----------



## Paladin79

Wes S said:


> Yes sir!  I know all about those tubes and the Glenn.  I was just giving you a hard time, because it looks funny, but I am sure they will sound insane in your Glenn.    I think I have quite a bit different taste in sound sigs than @L0rdGwyn, but I am sure many have similar taste as well.  I would love to know if there is an equivalent 6J5 to the Sylvania 6N7W metal base, like there seems to be for the Tung Sol BGRP.  The Tung Sol BGRP 6SN7 is killer, but the Sylvania W metal base is on another level.


There are some decent 6j5's out there and I own quite a few as well as 7A4's and some are certainly cheaper than 6sn7's but having included a few high end pairs in with some comparisons to quality 6sn7's, so far they do not rate that highly in blind testing. The 6sn7's can be more expensive because they are highly sought after and that is generally for a reason lol. The 6j5's offer a little better channel separation but that is only one factor in choosing a tube otherwise I would rate most along the lines of mid level RCA's and Sylvania's.


----------



## L0rdGwyn

Wes S said:


> Yes sir!  I know all about those tubes and the Glenn.  I was just giving you a hard time, because it looks funny, but I am sure they will sound insane in your Glenn.    I think I have quite a bit different taste in sound sigs than @L0rdGwyn, but I am sure many have similar taste as well.  I would love to know if there is an equivalent 6J5 to the Sylvania 6N7W metal base, like there seems to be for the Tung Sol BGRP.  The Tung Sol BGRP 6SN7 is killer, but the Sylvania W metal base is on another level.



The equivalent would be the military Sylvania 6J5GT aka the VT-94D.  Obviously opinions will vary, having owned just about all of the TOTL 6SN7s and 6J5s, IMO the differences are significant, especially for the better 6J5s like the Marconi-Osram L63, so you will just have to try them yourself and see if they float your boat.  A pair of Sylvania 6J5GT are relatively inexpensive, just need a 2x 6J5 to 12AU7 adapter.  More than a few prominent members of the 2359glenn thread have sold their 6SN7 collections, others have asked if I will modify their OTL amplifiers to take 6J5 instead, if that tells you anything, the consensus there is strong, but you very well might disagree, just follow your ears


----------



## L0rdGwyn

In fact @Wes S if you are interested, I will send you some 6J5 to try out with a 2x6J5 to 6SN7 adapter, would simply need to plug it into your existing 6SN7 adapter, shoot me a PM if you would like, I can send you a pair of the Sylvanias pictured above and another pair or two.


----------



## Paladin79

Wes S said:


> No worries, they are safe from me, as I am happy with this tube combo.


Nice photo and it is on topic lol.


----------



## Wes S (Jul 18, 2020)

Paladin79 said:


> There are some decent 6j5's out there and I own quite a few as well as 7A4's and some are certainly cheaper than 6sn7's but having included a few high end pairs in with some comparisons to quality 6sn7's, so far they do not rate that highly in blind testing. The 6sn7's can be more expensive because they are highly sought after and that is generally for a reason lol. The 6j5's offer a little better channel separation but that is only one factor in choosing a tube otherwise I would rate most along the lines of mid level RCA's and Sylvania's.


Thanks for sharing man!  I really don't think I could get past not seeing the glass and glow, and I guess it just depends on what you value.  The visual aspect of my gear plays a big role in my overall enjoyment, and I have a bad case of OCD, so I like my setups to look tidy and I love a good tube glow, as well.


----------



## L0rdGwyn

Just offering an alternative opinion since my name was mentioned here, I don't mean to rock the boat.  Enjoy the BHCs, it is a great amp, how I got my start in DIY amp building.


----------



## Paladin79 (Jul 18, 2020)

Wes S said:


> Thanks for sharing man!  I really don't think I could get past not seeing the glass and glow, and I guess it just depends on what you value.  The visual aspect of my gear plays a big role in my overall enjoyment, and I have a bad case of OCD, so I like my setups to look tidy and I love a good tube glow, as well.


If you get a chance to meet up with Ripper he has an extensive collection of 6SN7’s and I believe he is getting into 6j5’s as well but many of us have been there and done that, the tubes have been around for ages. I am not opposed to 6J5’s, some of the higher end will be in a 6SN7 equivalent blind listening but there are only 52 spots so we may be down to Osrams. Heck Ripper even owns a BH Crack waiting to be assembled. 

Here are some 7A4's in one of my BH Crack builds.


----------



## L0rdGwyn

I'm sorry one more thing to prove my membership as a Crack-head, here are my two Crack builds from a few years ago, still very proud of them!  Although I will never do that mirror finish again HA!  If I ever do, I'll take it to a shop to be chromed, hard to do a mirror finish when you are a perfectionist, it will drive you nutso.


----------



## JamieMcC

Some strange looking amps being listed on in eBay being described as Bottlehead Cracks in the discription.

https://www.ebay.co.uk/itm/Tube-Amp...346617?hash=item52389105f9:g:~UcAAOSwaOpe-Nva


----------



## raindownthunda

Wes S said:


> Thanks for sharing man!  I really don't think I could get past not seeing the glass and glow, and I guess it just depends on what you value.  The visual aspect of my gear plays a big role in my overall enjoyment, and I have a bad case of OCD, so I like my setups to look tidy and I love a good tube glow, as well.



One of my favorite things about the bottlehead crack is how versatile it is while sounding sounding excellent with such a large variety of tubes. Nothing wrong with prioritizing that clean aesthetic  Definitely was one of my priorities in building my kit. I just think it’s really cool how with a $30 adapter you can get tubes in the $10 range that are some of the best sounding tubes out there. From a pure value perspective it’s mind blowing! I wonder if anyone has ever modified the crack to take 2x 6j5 sockets natively instead of the 12au7...


----------



## Paladin79

JamieMcC said:


> Some strange looking amps being listed on in eBay being described as Bottlehead Cracks in the discription.
> 
> https://www.ebay.co.uk/itm/Tube-Amp...346617?hash=item52389105f9:g:~UcAAOSwaOpe-Nva


Bizarre all right.


----------



## Wes S

raindownthunda said:


> One of my favorite things about the bottlehead crack is how versatile it is while sounding sounding excellent with such a large variety of tubes. Nothing wrong with prioritizing that clean aesthetic  Definitely was one of my priorities in building my kit. I just think it’s really cool how with a $30 adapter you can get tubes in the $10 range that are some of the best sounding tubes out there. From a pure value perspective it’s mind blowing! I wonder if anyone has ever modified the crack to take 2x 6j5 sockets natively instead of the 12au7...


Good stuff!  I have looked at tons of pics of BHC's, and seen plenty with 6SN7 sockets (wouldn't mine this myself), but never dual 6J5.  That could be cool!


----------



## chrisdrop

Does anyone have a Crack spreadsheet (that they will share) like this one (infamous!) that @Zachik created for the Glenn OTLs?

I am going to bring my newly assembled (but largely neglected!) Crack to my office tomorrow (yes - offices still exist!). I have tubes aplenty, but only 1 little Brimar (BBC branded) 12AU7. (With adapters) what else can I put in that slot?! 

It will also give me a chance to use my Eikons again. Since lockdown I have been WFH mostly and on the VCs.


----------



## chrisdrop

Bendix 6080 + Brimar BBC 
Digging office setup so far


----------



## Wes S (Jul 23, 2020)

chrisdrop said:


> Bendix 6080 + Brimar BBC
> Digging office setup so far


Nice combo!  I had that exact same Brimar/Bendix combo going for a while and it's a good balanced sound, with a bit of warmth.  I love the mids and treble you get with Brimar tubes.


----------



## PsilocybinCube

Hey everybody, I am looking for some help finding a good link to new tube sockets for my BHC.  

Currently both my input and tube sockets are flush with the chassis of the Crack rather than sitting above the chassis as I see on everyone else's Crack.  The problem I'm having is that when using Deyan's 12au7 to 6sn7 adapter, the adapter doesn't fully push down, it strikes the screws holding the socket in place under the amp.  While that hasn't given me issues from a sonic perspective, it worries me that the adapter isn't 100% snug.  I'm sure I could carve out a little section of the plastic on the adapter to make it fit around the screws...but that doesn't seem like it would be aesthetically pleasing.  Also, as I bought this second-hand from @DenverW making the change myself will make me feel a little more connected to the BHC since I didn't build it myself. 

The Speedball upgrade is installed, if that matters.  When I look at the 9-pin sockets online, there are so many options, many of them only $2.50 or so, but I guess I want to go 'premium' since I'm only changing out a couple of these and the cost will be nominal.  I've been looking at something like this:  https://www.thetubestore.com/9-pin-teflon-gold-pin-tube-socket

For the 8-pin socket, something like this:  https://www.thetubestore.com/8-pin-teflon-gold-socket


So, my two main questions are this:


What specific tube sockets would you use if you were me and looking to replace them to go above the chassis?  Links appreciated.
Is there any way to use an 8-pin socket on the input tube rather than a 9-pin socket so the 6sn7 can be used without an adapter?  I'd imagine the answer is 'no,' but it doesn't hurt to ask...unless I am ridiculed for asking.  Then it will hurt.

Thanks!!!!


----------



## Paladin79

Nearly done with this cabinet.


----------



## raindownthunda

Paladin79 said:


> Nearly done with this cabinet.


Stunning!! What type of finish are you using?


----------



## Paladin79 (Jul 28, 2020)

raindownthunda said:


> Stunning!! What type of finish are you using?


That is six coats of clear lacquer with fine sanding in between coats followed by a museum grade wax I get out of England. That is the natural color of honey locust, it is not easy to find but it can be spectacular, I also used purpleheart splines. I am currently building a copper Faraday cage (transformer cover) since this is a steampunk amp.


----------



## barbz127

First time crack builder ordering an alps from parts express.

What else should I be ordering to tweak the crack over the coming months?


----------



## DenverW

barbz127 said:


> First time crack builder ordering an alps from parts express.
> 
> What else should I be ordering to tweak the crack over the coming months?



I would recommend this order:  speedball, alps, output caps, Cree diodes, choke, other caps.  Stop anytime


----------



## chrisdrop

What adapters are popular for the 12au7 socket? I thought I saw 6n7g tubes earlier on the thread (I have some nice ones), but was surprised by the "6"...


----------



## Wes S (Jul 29, 2020)

chrisdrop said:


> What adapters are popular for the 12au7 socket? I thought I saw 6n7g tubes earlier on the thread (I have some nice ones), but was surprised by the "6"...


@Deyan  Makes really nice ones.  Garage 1217 does too.

The one in the pic, is from @Deyan, amd this one is top notch point to point wiring.


----------



## Little Bear

Wes S said:


> @Deyan  Makes really nice ones.  Garage 1217 does too.
> 
> The one in the pic, is from @Deyan, amd this one is top notch point to point wiring.



Your volume knob seems to be sitting a little high.  Is it fully seated?


----------



## Wes S (Jul 29, 2020)

Little Bear said:


> Your volume knob seems to be sitting a little high.  Is it fully seated?


Good eye!  It is fully seated but I believe the shaft is a bit longer on the Alps Blue Velvet pot that was used, instead of the stock pot.  The pot is smooth as silk, has no play whatsoever,  and zero channel imbalance when I turn the knob.  I did not build this, and I assume the guy who did, didn't want to risk messing up the threads by cutting down the shaft, but I never asked because it works perfectly anyway.

With all the pics I have posted of my beloved BHC, I am shocked @Little Bear was the first to notice my high sitting pot.   My amp is a little special and has a little flaw, but hey it sounds and looks killer to me.


----------



## DenverW

Heh, I had the same issue with the length of the blue alps pot, so I had to break out the saw...


----------



## Wes S

DenverW said:


> Heh, I had the same issue with the length of the blue alps pot, so I had to break out the saw...


It doesn't bother me, which is actually kind of shocking for how OCD I am with everything.  I kind of like having my hand further away from the top plate when turning the knob, as to not cause microphonics from vibrations, but then again maybe I am just telling myself that, so I don't fret over it.


----------



## L0rdGwyn

If you ever wanted to switch to one that can take the longer shaft, Audio Note makes some nice brass knobs, a gold or black one might match well.  The bottom is counterbored so it hides the lock nut.  Lots of other options out there too on Mouser, Dig-Key, etc.

https://www.partsconnexion.com/audio-note-knobs.html

Or just use the completely functional stock one, just an idea!


----------



## DenverW

So I ordered one from China that was 25mm tall, thinking it would be perfect.  Unfortunately, the interior shaft was still 15 or so mm, just like all the others.  Annoying!


----------



## Little Bear

Wes S said:


> With all the pics I have posted of my beloved BHC, I am shocked @Little Bear was the first to notice my high sitting pot.   My amp is a little special and has a little flaw, but hey it sounds and looks killer to me.



Actually, it's because your BHC looks so nice that I stared at it long enough to notice!   Especially the nicely finished base.  Personally I like the knob currently on it, but if you wanted to drop it down a smidge, you could use a cutoff wheel on a Dremel tool to shorten the shaft a couple of mm's.  Or you could just paint the visible nut black so it isn't noticeable.  Doesn't matter though.  Nice Crack!


----------



## Astral Abyss

@Wes S Easiest way to cover that gap is to replace the knob with another one with a higher mounting point.  Richard has some really nice NOS bakelite knobs off old radios and I bet you could find one that would cover the base more and look unique.  I've bought a few knobs and tubes from him and everything is good quality.

https://www.etsy.com/shop/LeedsRadio?ref=pr_faveshops&section_id=13888066


----------



## Wes S

Astral Abyss said:


> @Wes S Easiest way to cover that gap is to replace the knob with another one with a higher mounting point.  Richard has some really nice NOS bakelite knobs off old radios and I bet you could find one that would cover the base more and look unique.  I've bought a few knobs and tubes from him and everything is good quality.
> 
> https://www.etsy.com/shop/LeedsRadio?ref=pr_faveshops&section_id=13888066


Thanks!  I have bought tubes from Richard, and know he is legit.  However, I am fine with it the way it is, and only talked about it because it was mentioned by someone else.  No worries folks, my BHC sounds and looks fine to me.


----------



## PsilocybinCube

Wes S said:


> Thanks!  I have bought tubes from Richard, and know he is legit.  However, I am fine with it the way it is, and only talked about it because it was mentioned by someone else.  No worries folks, my BHC sounds and looks fine to me.


Personally, I think it looks fine @Wes S .  That said, if anyone wants some free knobs, I have some I took off an old recurved I scrapped.  They are aluminum and pretty.


----------



## Bullpride

PsilocybinCube said:


> Personally, I think it looks fine @Wes S .  That said, if anyone wants some free knobs, I have some I took off an old recurved I scrapped.  They are aluminum and pretty.


I might be interested.  Depends on if the interior hole diameter is .250 (6.35) or larger .  I bought a 6mm and it doesn't fit on my PEC Pot.


----------



## chrisdrop

I'm very glad I used the amp (at my office of all places!) for a few weeks pre Speedball upgrade. The Speedball is a substantial improvement to my ears. I know Speedball is often listed as "upgrade #1". Do any of the other improvements come close to it?


----------



## Wes S

chrisdrop said:


> I'm very glad I used the amp (at my office of all places!) for a few weeks pre Speedball upgrade. The Speedball is a substantial improvement to my ears. I know Speedball is often listed as "upgrade #1". Do any of the other improvements come close to it?


Nice man!  Speedball and Alps Pot are all the extra's I have.  However, I have found changing from my "Top Tier" 12AU7's to my "Top Tier" 6SN7's with an adapter, was another major improvement.


----------



## Astral Abyss

Wes S said:


> Nice man!  Speedball and Alps Pot are all the extra's I have.  However, I have found changing from my "Top Tier" 12AU7's to my "Top Tier" 6SN7's with an adapter, was another major improvement.


Does using a 6SN7 in place of the 12AU7 require any modification of the circuit, or is the BH already capable of handling its power requirements?


----------



## Wes S

Astral Abyss said:


> Does using a 6SN7 in place of the 12AU7 require any modification of the circuit, or is the BH already capable of handling its power requirements?


As long as you have the Speedball mod, you are good to go with 6SN7's.


----------



## cddc

chrisdrop said:


> I'm very glad I used the amp (at my office of all places!) for a few weeks pre Speedball upgrade. The Speedball is a substantial improvement to my ears. I know Speedball is often listed as "upgrade #1". Do any of the other improvements come close to it?




I'd love to hear your impression on the changes before vs after the Speedball upgrade?

Also, would you mind sharing with us a little bit of your Crack w/ Speedball vs your GOTL, as I recall GOTL has no CCS load available?


----------



## PsilocybinCube

Wes S said:


> As long as you have the Speedball mod, you are good to go with 6SN7's.


The 6sn7 is a better tube.  Period.  Beware though...6sn7 collecting is highly addictive and it will make your BHC sound better than you imagined possible.


----------



## chrisdrop

cddc said:


> I'd love to hear your impression on the changes before vs after the Speedball upgrade?
> 
> Also, would you mind sharing with us a little bit of your Crack w/ Speedball vs your GOTL, as I recall GOTL has no CCS load available?


Funny you should mention GOTL CCS:

Here is a mod that @L0rdGwyn did for another GOTL owner and posted about yesterday. 



L0rdGwyn said:


> Sharing a little DIY side project I have been working on the last few days.
> 
> I have @whirlwind 's GOTL on hand for some surgical modifications.  Similar to what I did with my GOTL when I had it, I have replaced his loctal sockets for the C3g with octal sockets set up for 6/12J5.  The heaters for the SN7 socket have been daisy-chained to the new sockets, such that all three are affected by the rear switch, allowing the use of 12J5 as well.
> 
> ...



Glenn replied here: 



2359glenn said:


> Technically 1/2 of the 6AS7 is used as a CCS for the other 1/2.
> Sounds pretty good and no SS in the audio circuit.



Regarding Speedball upgrade; comparing Crack with and without Speedball (-Speedball, +Speedball).  This is my office setup (Eikon, Crack, D50s). Using reasonably nice tubes; Bendix 6080 output, 1954 Brimar 12AU7. No other upgrades (pot, caps, etc.).

Overall clearer/less grainy than the Crack -Speedball. Sometimes tubes can be euphonic/pleasing, at the cost of graininess (IMO). I sometimes experience this as a short period of enjoying "a change" followed soon by listening fatigue. I assume this is fatigue of hearing distortion. There is less of this fatigue +Speedball, but preserving the nice overall tone. 
General imaging improvement (perhaps enabled/unearthed by the general clarity improvements?)
Minor-scale comment but the Eikon has a bit of occasional edginess for me in the upper mids. +Speedball this has been more smooth with less frequent harshness. Perhaps that is also a comment on distortion as above? 
Regarding Crack vs GOTL. The comparison is confounded by several things. This is my home setup. 

Home has lot more tube options for the GOTL, acquired over time, some "expensive" or "rare". 
Home is using a Verite Closed with the GOTL (vs Eikon with the Crack). I love my Eikons, but IMO the VC is nicer (and more expensive of course). 
Home has a much nicer DAC, USB streamer, dedicate power circuit/regeneration, cables, etc. This surrounding system is critically important IMO. 
Totally different price-points. The Goldpoint stepped attenuator in the GOTL is almost as expensive as the whole Crack. While it is not a _very_ expensive amp, it is a multiple of Crack cost. It is possible to put in tubes that in total cost as much as the Crack.
It is hard to compare because of all those reasons. I certainly prefer my home setup but that is a function of all things. I am happy to have both setups. I am, however, impressed with the Crack. I got it as a learning project more than for use, and I am quite thankful and happy to use it. 

I generally think there are better input tubes than the 12AU7 family and I'll have to get some adapters to give 2x 6J5*s (which I prefer to 6SN7*, but are equavalent) or 6N7*s.

Regarding CCS/ voltage/ adapters; the comment earlier suggests that +Speedball you can just plug in a 6v tube to the 12AU7 slot. That is surprising, but - I am inexperienced here, so the novelty is closely related of my lack of informedness! To the uninformed such as me, it is all new/novel 

Sorry for the long post, but perhaps it answers the questions in part.


----------



## flailure

chrisdrop said:


> Funny you should mention GOTL CCS:
> 
> Here is a mod that @L0rdGwyn did for another GOTL owner and posted about yesterday.
> 
> ...



12au7 can be heated using either 12 v or 6 v depending on whether you wire the heaters in series or parallel.  Crack is setup for and uses 6v, so as long as you use the proper adapter (or if you want to swap the miniature 9 pin base to an octal like I did, make sure you rewire the octal for 6sn7 configuration and ensure that you do not accidentally put a 6080 into the modified slot as it is an octal but not the same pinout, I ended up marking the slots for their respective tube families after making that change) then the largest change is in amps needed for the 6sn7 heater over what was needed by the 12AU7.   6sn7 is rated for 600ma vs 12AU7 at 300ma.  Transformers are the limitation when it comes to how many amps can be handled for tube amp heater circuits, and my understanding is that the bottlehead crack transformer included with the kit is rated for 3.5 amps (approx).  6080 pulls roughly 2.6 amp, add another .6amp for 6sn7 and you are at 3.2 amp and still within tolerances.  I do not wish to speculate on why bottlehead designed their amplifier with 12au7 and 6080 tubes as opposed to 6sn7 and 6080, but if I were to, I suspect it was to prevent the inevitable tube mix up that would happen if they had gone 6sn7 with 6080, as both use an octal base.  You know at some point someone would insert the wrong tube in the wrong base, and that would cause some damage.  

As to whether the change from 12AU7 to 6sn7 is worth it, well thats up to the user to determine, i find the changes to be more subtle as opposed to the sweeping changes that most seem to profess.  I mainly swapped to 6sn7 as I had a decent stockpile of 6sn7 family tubes set aside from a previous amp.  And it is nice to swap out tubes every so often, just so your brain doesn't become too used to one particular configuration.   Kind of like clearing your aural palette as it were.


----------



## cddc

chrisdrop said:


> Funny you should mention GOTL CCS:
> 
> Here is a mod that @L0rdGwyn did for another GOTL owner and posted about yesterday.
> 
> ...



You might be a new Cracker owner here, but you are definitely not new to tubes, you are a veteran now in tube rolling...LOL 

Great review on the Speedball upgrade, quite close to my vague memory on the Speedball upgrade (as I had my stock Crack for only 3 days and quickly upgraded it with Speedball). The Speedball does bring more refinement and clarity to the sound as I remember.

It is true that it would be unfair to compare the Crack + Speedball with GOTL directly as their pricing points are quite different...just curious to see how much a difference it would be, especially given the improvements that Speedball brings. You can possibly bring your Crack home someday when holiday comes and do a true A/B comparison with all your premium rigs and premium tubes at home.

I guess you've already collected lots of premium 6SN7 tubes for your GOTL, so all you need is a 6SN7-to-12AU7 adapter, and you can try these 6SN7 tubes in your Crack. Just make sure you get the 6.3V version of 6SN7-to-12AU7 adapter, as Crack runs 6.3V heater. You can tell Deyan that you need a 6.3V 6SN7-to-12AU7 adapter, I'm pretty sure he knows exactly how to wire the adapter.


----------



## Mightygrey

I'm using this Garage1217 12AU7 > 6SN7 adapter in my Crack, which works perfectly.


----------



## Little Bear

Mightygrey said:


> I'm using this Garage1217 12AU7 > 6SN7 adapter in my Crack, which works perfectly.



Your "this" link goes to page one of this thread.


----------



## cddc

Little Bear said:


> Your "this" link goes to page one of this thread.




I am not a fan of these Garage1217 adapters. They have contact points exposed, which can be very dangerous - they can cause shock or short if touched.

We had a user here with this Garage adapter and the contact points touched the top plate of his Crack and created shorts. Luckily the user quickly turned off his Crack when he saw the rising smoke, and nothing was damaged, IIRC. That happened just several weeks ago, if you look back a few pages here you could find the incident.

BTW, your icon is the same as Doc B's


----------



## cddc

The incident can be found here:
https://www.head-fi.org/threads/crack-bottlehead-otl.476650/post-15640259


----------



## Wes S (Aug 11, 2020)

cddc said:


> I am not a fan of these Garage1217 adapters. They have contact points exposed, which can be very dangerous - they can cause shock or short if touched.
> 
> We had a user here with this Garage adapter and the contact points touched the top plate of his Crack and created shorts. Luckily the user quickly turned off his Crack when he saw the rising smoke, and nothing was damaged, IIRC. That happened just several weeks ago, if you look back a few pages here you could find the incident.
> 
> BTW, your icon is the same as Doc B's


The good thing, is the Garage 1217 mentions this issue on their website, so they are aware and make the buyers aware as well.  The whole issue with the one case, is that the socket wasn't properly installed, and the buyer did not read the directions, at least that's what I gathered. Honestly, I don't care for the look, but they did work perfectly fine in my BHC.  However, @Deyan makes much better ones, with point to point wiring.


----------



## cddc

Wes S said:


> The good thing, is the Garage 1217 mentions this issue on their website, so they are aware and make the buyers aware as well.  The whole issue with the one case, is that the socket wasn't properly installed, and the buyer did not read the directions, at least that's what I gathered. Honestly, I don't care for the look, but they did work perfectly fine in my BHC.  However, @Deyan makes much better ones, with point to point wiring.




Yes, Deyan makes excellent adapters, that's why I recommended him.

The Garage 1217 adapter may work well in Crack if cares are taken, however the exposed metal between the top socket and PCB as well as the exposed solder joints beneath the PCB still present big hazards. It is a half done product. Tube amps are high voltage equipments. Imagine an innocent kid touches the exposed metal, that could be life threatening. 

Your Deyan adapter looks great


----------



## Bullpride

Just spoke with Deyan about an adapter.  Now what  6SN7  should I pick up, and where to get it from?


----------



## PsilocybinCube

cddc said:


> I am not a fan of these Garage1217 adapters. They have contact points exposed, which can be very dangerous - they can cause shock or short if touched.
> 
> We had a user here with this Garage adapter and the contact points touched the top plate of his Crack and created shorts. Luckily the user quickly turned off his Crack when he saw the rising smoke, and nothing was damaged, IIRC. That happened just several weeks ago, if you look back a few pages here you could find the incident.
> 
> BTW, your icon is the same as Doc B's


Yes, that was me.  Thankfully all is still well with my amp.  The adapter from Deyan was much, much better on several fronts, mostly it provides a better chassis for pulling on and off of the amp.

And yes, the smell of solder smoking in the morning is not pleasant.  Thank goodness I only left it on for a few seconds before recognizing it wasn't going to end well.


----------



## PsilocybinCube

Bullpride said:


> Just spoke with Deyan about an adapter.  Now what  6SN7  should I pick up, and where to get it from?





Bullpride said:


> Just spoke with Deyan about an adapter.  Now what  6SN7  should I pick up, and where to get it from?


You should hop on the 6sn7 addict's thread and get ready to deep dive.

That said, for a cheaper tube, there are a couple I could recommend.  The Sylvania 'Bad Boy' can usually be had for cheap.  The Westinghouse Reliatron is very inexpensive and can be had for quite cheap.  The Ken Rad black glass is the favorite of many tube rollers, though it's a bit more expensive ($60 - $80usd).

I like the National Union black glass and that tube can also be obtained very inexpensive.

The RCA grey glass with the meatball sounds quite nice, but I seem to have bad luck with them being microphonic (I think it's bad luck on my part more than it being a bad tube).

I've accumulated 20 or so 6sn7 tubes since going down the rabbit hole.  They are a fun tube.

6sn7 thread:  https://www.head-fi.org/threads/6sn7-tube-addicts.479031/page-469#post-15796475


----------



## cddc

6SN7 is a very deep rabbit hole, it could cost you lots of money, be careful folks 🤭

Some 6SN7 tube can cost more than Crack w/ Speedball...


----------



## cddc

PsilocybinCube said:


> The RCA grey glass with the meatball sounds quite nice, but I seem to have bad luck with them being microphonic (I think it's bad luck on my part more than it being a bad tube).



That's definitely a problem of that particular tube. I've never heard RCA grey glass having microphonic issues.


----------



## PsilocybinCube

cddc said:


> That's definitely a problem of that particular tube. I've never heard RCA grey glass having microphonic issues.


For sure.  It's why trusted sellers are so crucial to find.  I bought dud tubes for sure.  They are highly regarded so I know it's a fluke.  

They were listed as NOS and one had a loose base out of the box.  I think every tube roller gets the crappy end of a deal every now and then.

Then again, I've bought some tube lots (untested) and gotten some gems.  

Tubes are like a box of chocolates....


----------



## DenverW

SO I just finished upgrading the power supply caps in my crack.  I replaced them with 470uf 250v, up from the 270uf.  Then I bypassed the final cap with a 1uf mundorf supreme (the poor mans way to mundorf sound!).  I still havent replaced the output caps yet, because they took 3 months to arrive from russia, but even without that last upgrade (i've already installed a choke, cree diodes, and alps pot) it just sounds...

so 
very 
very
good.

I'm a happy camper right now.  I'll put in the kzk white line 100uf output caps this weekend.  Then my head will explode (hopefully not my amp!)


----------



## DenverW

So I installed the output caps tonight.  What a squeze!  A bit tight in there now, so much so that I can just barely get the plate to fit right.

But I think everyone is right, this is the biggest impact since the speedball.  Soundstage and separation improved, and this is right on powering up for the first time, without 'burning' them in.  So, since i've pretty much run out of upgrades, the question is, "what now?"  First, I'm going to enjoy this amp a bit, but the inevitable bug will strike me, and I'll start wondering about the crackatwoa.  Perhaps I can find someone local who'd like to buy this amp so I can start all over .


----------



## cddc

Show us some pics of inside....to see how tight a fit it is


----------



## DenverW

That would mean I'd have to turn it off....


----------



## cddc

DenverW said:


> So I installed the output caps tonight.  What a squeze!  A bit tight in there now, so much so that I can just barely get the plate to fit right.
> 
> But I think everyone is right, this is the biggest impact since the speedball.  Soundstage and separation improved, and this is right on powering up for the first time, without 'burning' them in.  So, since i've pretty much run out of upgrades, the question is, "what now?"  First, I'm going to enjoy this amp a bit, but the inevitable bug will strike me, and I'll start wondering about the crackatwoa.  Perhaps I can find someone local who'd like to buy this amp so I can start all over .




I'm definitely not a tech-savvy. Haven't really looked into Cracka2a, but I remember it is marketed as having improved power supply by using shunt tube, IIRC?

What is a shunt tube? I can understand ordinary rectifier tubes, but I have no idea how shunt tubes work, how they differ from rectifier tubes, and how they can improve the power supply.


----------



## cddc

DenverW said:


> That would mean I'd have to turn it off....




I can see some additional space to squeeze in more caps....LOL

Just kidding...quite packed already, great work!


----------



## cebuboy

DenverW said:


> That would mean I'd have to turn it off....


Welp, there's still room for a pair of bypass caps


----------



## DenverW

cebuboy said:


> Welp, there's still room for a pair of bypass caps



Now THERES an idea....


----------



## Majestyk (Aug 20, 2020)

Two questions... I'm thinking about buying an assembled (stock) Crack with SB and I'm curious what the soundstage is like compared to solid state amps, like the THX series amps for example. Right now I use a vintage receiver and the soundstage just smokes the Monoprice THX amp I tried awhile back.

Also, I might get one with Mundorf caps. How much of an upgrade in sonics would they make?

Thanks.


----------



## GreenNeedle (Aug 22, 2020)

Started wanting to emulate another member's dark stained rounded corner with polished top crack and my desires changed too many times. lol.

Here is the finished (still stock) crack.  Exclusive to head-fi as despite buying the crack and trying to register on the BH forum several times with 3 different e-mail addresses it was to no avail.  They don't want me   I went with the stock base in the end, veneered in Santos Rosewood.  Danish Oil finish, Cream enamelled top, black hammered bell and 12AU7 clamp.

It has a TKD 2cp-2511 volume pot which is the smoothest I have ever experienced, both in actual feel and audibly.  The volume knob was from ebay and a little taller than I wanted but I have grown to like it.  The feet are spikes with little disks for them to sit in.  Yes they are for speakers but I like them.

Tubes are Tung-Sol 5998 and Mazda 12AU7.   The Tung Sol needs no introduction but the Mazda is cheap (£20) and readily available.  Both the British and "foreign" version sounds really good and thus I have bought a few of these.  I have quite a lot of 12AU7 variants at this point but the Mazda (IMO) is one of those that people will learn about and prices will rise.

I will try other tubes with adaptors in the 12AU7 spot but only once I have done the speedball........which at this point I am in no rush to do.

Anyway pictures.  Forgive the mess behind, I am in the midst of several projects:


----------



## JTori

GreenNeedle said:


> Started wanting to emulate another member's dark stained rounded corner with polished top crack and my desires changed too many times. lol.
> 
> Here is the finished (still stock) crack.  Exclusive to head-fi as despite buying the crack and trying to register on the BH forum several times with 3 different e-mail addresses it was to no avail.  They don't want me   I went with the stock base in the end, veneered in Santos Rosewood.  Danish Oil finish, Cream enamelled top, black hammered bell and 12AU7 clamp.
> 
> ...


Absolutely beautiful!  Love the oiled rosewood base and cream top.  Having built three BH amps (Crack/Speedball, Mainline and Crack-a-two-a), I would say that once you're ready, the Speedball is a meaningful upgrade.  Then, having had a taste of that, I wondered what's the platform capable of and weighed modifying my Crack vs. building the C2A.  I opted for the C2A and haven't looked back!  It's my favorite of the three.  Enjoy your amp.  You've done an exceptional job on it!

Joe.


----------



## cddc (Aug 23, 2020)

GreenNeedle said:


> Started wanting to emulate another member's dark stained rounded corner with polished top crack and my desires changed too many times. lol.
> 
> Here is the finished (still stock) crack.  Exclusive to head-fi as despite buying the crack and trying to register on the BH forum several times with 3 different e-mail addresses it was to no avail.  They don't want me   I went with the stock base in the end, veneered in Santos Rosewood.  Danish Oil finish, Cream enamelled top, black hammered bell and 12AU7 clamp.
> 
> ...




Looks gorgeous!

How did you paint the top as smooth as a mirror? I can't believe the finish is even better than those from appliance factories. Fantastic job!


----------



## PsilocybinCube

Hey fellow BHC owners.  Quick question - has anyone here rolled in a 12bh7 tube into their Crack?  Speedball is a must I believe, I'm eager to try the tube but wanted to verify the usability first.


----------



## GreenNeedle

cddc said:


> Looks gorgeous!
> 
> How did you paint the top as smooth as a mirror? I can't believe the finish is even better than those from appliance factories. Fantastic job!



It isn't as smooth as it looks.  I intentionally wanted that enamelled look so it isn't "piano finish."  It isn't like the Orange peel effect from car paints though.  I guess enamel spray does have a smoother finish than your standard acrylic paint though.

If I had wanted a smooth finish, then I would have sprayed an acrylic paint.  Then sprayed clearcoat, then run through the wet and dry grades, culminating with some Brasso because I hate paying loads for a rubbing compound when Brasso works very well.

I'll take a few pictures at some point closer up to the finish so you can see.  

The spray I used was "Rustoleum Mode" which is an ultra glossy finish.  Spray loads of coats thinly every 20 mins hour until you are there.  Spray it too thick and it won't go hard.  I learned that early.  It also does not like baking   The Hammerite on the bell was fine with me baking it hard.  The "Mode" bubbled so was scraped off and second attempt made sprayed thinly and no baking this time.  About 10 thin coats on this.  Could still see mismatched colours of the metal showing through until the 3rd/4th coat.


----------



## GreenNeedle (Aug 24, 2020)

OK, I took a few pictures.  I hate close-ups.  They show too much dust, lol.

I took some pictures of my turntable which I have finished too so they match.  They are in temporary places at the moment because I am re-doing the area they will eventually reside.

So firstly the turntable (please ignore the dust. lol)  First pic gives an idea of the finish on the front edge of the chassis:




From just a little bit away it looks much smoother:




And from a distance it looks really smooth.  Notice also the rim of the platter, which I have polished up.  In the extreme close up you can see tiny scratches, In the second you can barely see them.  In the photo below it looks like I spent hours polishing it.  I could have and may well do in the future but for now it is just a basic fine wet and dry with a quick rub with Brasso:




Similarly with the Crack, the earlier post it looks smooth and does so in its current position:




But get up close and you see that enamelled finish (and all the dust  ):


----------



## GreenNeedle

PsilocybinCube said:


> Hey fellow BHC owners.  Quick question - has anyone here rolled in a 12bh7 tube into their Crack?  Speedball is a must I believe, I'm eager to try the tube but wanted to verify the usability first.



Pretty sure from reading the whole 140+ pages of the Crack tube rolling thread on the BH forum that to use the 12bh7 without risking damage to the unit requires some rewiring at a minimum.


----------



## Little Bear

GreenNeedle said:


> trying to register on the BH forum several times with 3 different e-mail addresses it was to no avail.  They don't want me



I had the same problem.  If you email Dan Schmalle (Doc Bottlehead), he'll activate your account manually.  They're having problems with their email notifications.


----------



## Bullpride (Aug 24, 2020)

PsilocybinCube said:


> Hey fellow BHC owners.  Quick question - has anyone here rolled in a 12bh7 tube into their Crack?  Speedball is a must I believe, I'm eager to try the tube but wanted to verify the usability first.


https://forum.bottlehead.com/index.php?topic=663.0

Tube Rolling Crack thread suggests this tube requires the Speedball upgrade to use.

Apologies, I didn't see the login issues.  Here is the meat of the original post.

\
*DROP-IN EQUIVALENTS

Input Tubes (Original: 12AU7)*

12AU7(A)(WA)
ECC186
ECC82
ECC802(S)
E8025
E82CC
CV4003
CV4122
CV491
5814(A)
6189(W)(WA)
6680 (WL6680)
6067
7489
7316
5963 (computer version of 12AU7)

Sort-of-Drop-In (but not equivalent - for best results, replace plate resistors with Speedball boards)

E80CC
12BH7

*Power/Output (Original: 6080)*

6AS7G
6080
6H13C
5998
7236
6N13
*NOT THE 6SN7!!!!!*


----------



## PsilocybinCube

GreenNeedle said:


> Pretty sure from reading the whole 140+ pages of the Crack tube rolling thread on the BH forum that to use the 12bh7 without risking damage to the unit requires some rewiring at a minimum.


Yes, I have the Speedball upgrade.  I suppose I'm wondering it requires more than that.  I can't find anything staying more is needed...but it makes me nervous.


----------



## GreenNeedle

PsilocybinCube said:


> Yes, I have the Speedball upgrade.  I suppose I'm wondering it requires more than that.  I can't find anything staying more is needed...but it makes me nervous.



It may well be just the speedball needed.  I think it is quite early on in the tube rolling thread on the BH forum but it wasn't something I was really looking at so didn't pay too much attention.  My focus has been more on 12AU7 variants as well as after speedball 6NS7 variants in that position.  The BH thread is well worth the read though if for nothing more than knowing what you can and can't use and what others you can use with slight adaptations/adaptors.


----------



## Tom-s (Aug 24, 2020)

Look at the E80CC/12BH7 modifications thread on the BH forum and all info's there.
https://forum.bottlehead.com/index.php?topic=5989.225

As you'll learn from that thread; the 12BH7 wants 7-10mA current to optimize it in Crack. This is done by lowering the R1 resistance on the CCS (see post 226).
If you ask this much current from the Speedball small boards it's best to change the MJE-350 transistor to MJE 5731A to accommodate the extra heat dissipation.

Edit: I've enjoyed +-10 different 12BH7's and liked all of them! Very engaging sound. Great mid range. Spacious. Nice tube for Crack. I mostly prefer it over the more steroid like sound of E80CC and over ECC82's.


----------



## cddc (Aug 26, 2020)

GreenNeedle said:


> It isn't as smooth as it looks.  I intentionally wanted that enamelled look so it isn't "piano finish."  It isn't like the Orange peel effect from car paints though.  I guess enamel spray does have a smoother finish than your standard acrylic paint though.
> 
> If I had wanted a smooth finish, then I would have sprayed an acrylic paint.  Then sprayed clearcoat, then run through the wet and dry grades, culminating with some Brasso because I hate paying loads for a rubbing compound when Brasso works very well.
> 
> ...





GreenNeedle said:


> OK, I took a few pictures.  I hate close-ups.  They show too much dust, lol.
> 
> I took some pictures of my turntable which I have finished too so they match.  They are in temporary places at the moment because I am re-doing the area they will eventually reside.
> 
> ...





Your work on painting the plate and case is definitely artistic / professional. I wish I had your level of skills on painting. 😝

My Crack to date is still sitting on naked wood, because of my innocence in woodworking and painting. 😭 ...somehow I like the natural color of wood, so it didn't bother me too much.

With my clumsy hands, my painting skill is really bad. I had to use up the whole can of paint to just get one finished top plate, so here is my story: 😭 it all started with some Youtube video watching, I watched some spray painting tutorials and thought it's a piece of cake. So I started working on it.... Gee, why the finish was uneven after I sprayed 4 or 5 layers...no problem, I thought to myself, just remove the paint and paint the plate again. So I found myself some kitchen towel and tried to wipe off the paint....What...the paint was so sticky, it couldn't be wiped off completely, there was always some paint residual holding on to the plate like it's born there 🥵. I was so desperate, I thought it's impossible to remove the residual paint unless I can find some solvent, but I didn't know what is a good solvent for the paint. What's worse, my hands got painted too when I tried to wipe off the paint...and the paint couldn't be washed away by soap or dish detergent (only days later it seemed to disappear by itself). So I had to re-paint the plate with bumpy residuals, hoping that the new layers would cover them up, but no luck, the finish was still uneven. Sprayed and wiped off, sprayed and wiped off, so it went. I lost count on how many cycles I repeated...until finally I got some good even finish, by which time the can of paint was nearly depleted. Some people said you can paint 10 plates or more with one can of spray paint, but I got only one 😬. And here it is:




My soldering skill sucks too. I hoped to add some bypassing caps or Crees to my Crack, but never dared to do it...what if my perfectly working Crack is ruined during the mod...😝


----------



## PsilocybinCube

Tom-s said:


> Look at the E80CC/12BH7 modifications thread on the BH forum and all info's there.
> https://forum.bottlehead.com/index.php?topic=5989.225
> 
> As you'll learn from that thread; the 12BH7 wants 7-10mA current to optimize it in Crack. This is done by lowering the R1 resistance on the CCS (see post 226).
> ...


Hey, thanks for the detailed reply.  I read the posts you referenced and may give this a whirl.  The change doesn't seem too difficult.


----------



## GreenNeedle (Aug 26, 2020)

cddc said:


> Your work on painting the plate and case is definitely artistic / professional. I wish I had your level of skills on painting. 😝
> 
> My Crack to date is still sitting on naked wood, because of my innocence in woodworking and painting. 😭 ...somehow I like the natural color of wood, so it didn't bother me too much.
> 
> ...


Your finish looks fine to me but then I don't know what you were after   A lot of people try to spray too much in one go.  Takes a lot of skill (that I don't have) to put a wet coat on without runs or lumps, so I will do 10+ "flash coats" with 20 mins or so in between.  If there are any bumps then 2 hours and a gentle wet sand, waft a tacky rag over the top to pick up dust without leaving an impression and then flash further.

As a guide your avatar is a guitar with a "piano gloss" finish.  A Pro can wet spray that to perfection.  I would spray clear as above maybe 20x.  Then get to the wet and dry and rubbing compounds.

Don't worry about how far a can goes.  I did the turntable and the Crack from 1 can but not much left in them.  I've had quite a bit of practice with spraying as I have done all sorts over the past decade.  I just restored an old Raleigh steel frame which took many less cans than I used a decade ago.  Like everything it takes practice and then you find a way you are happy with.  Maybe not perfect, not quite as good as the pros but it works for you to achieve a finish you are happy with.



Same with finishing your crack.  If you like natural get a natural oil finish.  doesn't have to be Danish Oil.  For that low lustre finish you could use pure linseed Oil.  Best way for a newbie I would suggest is to paint it on with a brush quite quickly, then get a t-shirt and immediately wipe it in/off.  Repeat a few times, then leave a week for it to harden.  Instructions will tell you to wipe off after half an hour but I find it can already be curing on the surface by that time and make a mess.  After quite a few oiling project I tend to wipe it on now and leave it.

Linseed Oil will darken and yellow it a little but not as much as a glossier finish.  Like an aged Cricket bat colour with Linseed Oil.


----------



## cddc

Spray painting is definitely very challenging, way more difficult than the seemingly easy ones demo'd in some YouTube videos. Bumps and runs are high probability events for noobs. It's very difficult to control how much to spray each time, how much distance to keep, and how to spray the paint evenly. Definitely it takes lots of practice to get a good handle on it.

The steel frame looks fabulous! Professional grade, great job as always!

Thanks a lot for the recommendations.


----------



## tintinsnowydog (Aug 28, 2020)

New crack owner who just installed the speedball tonight! Still trawling through the 686 pages on this thread but wanted to drop my first impressions on the stock circuit and speedball. I'm sure many more detailed and better descriptions are scattered through the thread but since it's so long I thought it wouldn't hurt to scatter another one in. I can offer some good comparison to the la figaro 339 amp which I have used as my main amp for the past 1.5 years if anyone is out looking for pairings with Sennheiser HD6X0 and 800s.

The stock crack sounded like a more polite, smaller and cuter version of the LF339. The LF339 had more power, bigger soundstage and better tonality. The crack sounded faster and slightly more technical, but I felt it lacked the bass extension that you can feel, even using ceramic plate bendix style 6080s. Overall I would describe the character of the stock crack as fun compared to a 'grand' LF339 sound. The HD650s were equally enjoyable out of both, HD600 and 800 brighter out of the crack but also more controlled, more diffuse but warmer out of the LF339.

The speedball upgrade made a huge difference to my ears as I basically haven't used any solid state stuff since I got the LF339. I initially thought I had miswired something as the sound was so much brighter and thinner. After I got past the change in timbre though I was very impressed with how well it improved the technicalities of the crack. Bass was super tight and controlled, essentially solid state sounding, and more linear sounding throughout as expected from the circuit change. I'd say that the HD650 with speedball sounded like a HD600 out of the LF339, and the HD800s a little bright for my liking. Overall it somewhat eliminated the tube characteristics of the crack in exchange for great technical advancements. I think the speedballed crack and LF339 have very different sound signatures, and I'll definitely be keeping both around as they complement each other quite nicely.

While I have an extensive collection of tubes for the LF339, I need to roll through more tubes in the driver slot in the crack still. Will update with impressions there!


----------



## cddc

Nice review, speedball definitely reduces the syrupy tubeyness IMHO.

Welcome on board!


----------



## GreenNeedle

tintinsnowydog said:


> New crack owner who just installed the speedball tonight! Still trawling through the 686 pages on this thread but wanted to drop my first impressions on the stock circuit and speedball. I'm sure many more detailed and better descriptions are scattered through the thread but since it's so long I thought it wouldn't hurt to scatter another one in. I can offer some good comparison to the la figaro 339 amp which I have used as my main amp for the past 1.5 years if anyone is out looking for pairings with Sennheiser HD6X0 and 800s.
> 
> The stock crack sounded like a more polite, smaller and cuter version of the LF339. The LF339 had more power, bigger soundstage and better tonality. The crack sounded faster and slightly more technical, but I felt it lacked the bass extension that you can feel, even using ceramic plate bendix style 6080s. Overall I would describe the character of the stock crack as fun compared to a 'grand' LF339 sound. The HD650s were equally enjoyable out of both, HD600 and 800 brighter out of the crack but also more controlled, more diffuse but warmer out of the LF339.
> 
> ...





cddc said:


> Nice review, speedball definitely reduces the syrupy tubeyness IMHO.
> 
> Welcome on board!



This is probably why I am holding back on putting the speedball in there.  Not sure I would say "syrupy" but I already have a nice sounding vintage Solid State Amp which the headphones sound great out of.  Not overly sure that I want a solid state sound from the Crack.


----------



## PsilocybinCube

As has been said many times, I highly recommend getting a 12au7 to 6sn7 adapter.  It should work fine with the Speedball and the 6sn7 (IMO) is such a better and more interesting tube.  Plus they are infinitely collectible and addicting.


----------



## lalawilson168

Hi guys, I'm fairly new to this and am interested in building the crack with no prior experience in this. Purely on assembling the unit, would the soldering kit in that link be sufficient? And also if anyone has any good recommendations for paints or stains to use for the wood and plate preferably on amazon that would be nice. 

https://www.amazon.co.uk/gp/aw/d/B07PLX3BL8/ref=ox_sc_act_image_1?smid=A3UILG0Y2VPYFY&psc=1

Also I do own a DV 336se, would you say its an upgrade to it?


----------



## GreenNeedle

lalawilson168 said:


> Hi guys, I'm fairly new to this and am interested in building the crack with no prior experience in this. Purely on assembling the unit, would the soldering kit in that link be sufficient? And also if anyone has any good recommendations for paints or stains to use for the wood and plate preferably on amazon that would be nice.
> 
> https://www.amazon.co.uk/gp/aw/d/B07PLX3BL8/ref=ox_sc_act_image_1?smid=A3UILG0Y2VPYFY&psc=1
> 
> Also I do own a DV 336se, would you say its an upgrade to it?



The soldering iron I have is a pretty cheap station like this:
https://www.amazon.co.uk/312091-KAT...tions&qid=1598717179&sr=8-23&ts_id=1939419031

I wouldn't worry too much about buying a "kit."  I pretty much used the soldering station, a pair of needle nose pliers, a pair of 4x reading glasses and some Rosin core solder.

In terms of paints and stains that would depend on desired finish and experience.  There are some that give great finish but a re very hard to work with without experience.  It's pretty much on you to research like mad, not just on how to do things but experiences that others have had (especially inexperienced.)   That way you learn from other's mistakes and reduce your own.


----------



## GreenNeedle

PsilocybinCube said:


> As has been said many times, I highly recommend getting a 12au7 to 6sn7 adapter.  It should work fine with the Speedball and the 6sn7 (IMO) is such a better and more interesting tube.  Plus they are infinitely collectible and addicting.



I do have an adaptor and a  Tung Sol 6SN7GT already.  I may well try it in the stock amp (which I think is OK to do.)  Still not sure about making the crack sound like a solid state though.  anyone can chime in on this subject?


----------



## Little Bear

GreenNeedle said:


> Still not sure about making the crack sound like a solid state though.  anyone can chime in on this subject?



Why would one want to?  The point of a tube amp is for it to sound like a tube amp.  Especially true of an OTL like the Crack or C2A.


----------



## chrisdrop

Little Bear said:


> Why would one want to?  The point of a tube amp is for it to sound like a tube amp.  Especially true of an OTL like the Crack or C2A.


IMO Speedball does not make the amp sound like a solid-state amp. It makes it sound like a better OTL amp.


----------



## PsilocybinCube

Little Bear said:


> Why would one want to?  The point of a tube amp is for it to sound like a tube amp.  Especially true of an OTL like the Crack or C2A.


If it's a syrupy tube sound you are after, opening up to a wider range of tubes will only give you more of an ability to enjoy that sound.  I like the 12au7 ok, but I personally think the 6sn7 has a wider variety of potential sounds.  Of course, that's just my opinion and I am admittedly totally obsessed with the 6sn7 tube.


----------



## cddc

GreenNeedle said:


> This is probably why I am holding back on putting the speedball in there.  Not sure I would say "syrupy" but I already have a nice sounding vintage Solid State Amp which the headphones sound great out of.  Not overly sure that I want a solid state sound from the Crack.




LOL..."syrupy" might be a little bit exaggerated. 

But the stock Crack w/o Speedball did sound lush, smooth, and quite tubey to me, even though only 3 days in my short possession, its tubeyness really impressed me.

I personally won't say the Speedball makes Crack sound like SS, but it does reduce the tubeyness IMHO.

If you are good at soldering, I think it won't be a problem at all. Just try the Speedball by yourself, if you don't like it, just remove it and add back the 2 resistors. Just make sure you don't cut the 2 resistors too short when you add the Speedball, so that they can be added back.


----------



## PsilocybinCube

To be clear, I'm not saying the Speedball makes it sound like maple syrup.  I'm just saying that having access to 12au7 tubes and 6sn7 let's you access warmer driver, smoother driver tubes OR much more clinical detail tubes.  There is a bigger range of possible sonic outcomes with a 6sn7 compared with a 12au7.  That's my claim.


----------



## GreenNeedle

Thanks for those replies.  I'm not that great at soldering but I got the stock one working with no problems.  I guess I can desolder the resistors and try the speedball out.  I can even try out the "half" speedball with just the small board and see what I prefer.

I'll try out the 6SN7 with adaptor before I do any of the above though so I can hear the differences of both the 12AU7 and 6SN7 with all 3 stages of the stock > half speedball > full speedball "upgrade" and will wait until I can get this registration thing sorted on the BH forum before doing it, just in case I do have problems.

It may well be that I just like the "syrupy" cuddly warm blanket of the stock version.


----------



## carlman14

Here's some adapter madness for the BHC for y'all. Looks ridiculous, but the tube rolling is fun.

First: 12AU7 -> 6SN7 -> dual 6J5 -> Cunningham 6C5g tubes
Second: 12AU7 -> 6SN7 -> dual 6J5 -> 6C4 -> Tung-Sol 6C4 tubes


----------



## JazzVinyl (Sep 1, 2020)

carlman14 said:


> Here's some adapter madness for the BHC for y'all. Looks ridiculous, but the tube rolling is fun.
> 
> First: 12AU7 -> 6SN7 -> dual 6J5 -> Cunningham 6C5g tubes
> Second: 12AU7 -> 6SN7 -> dual 6J5 -> 6C4 -> Tung-Sol 6C4 tubes






Does look fun!  Are you turning the heater voltage down from 12 to 6 volts,  to run these tubes?


----------



## carlman14

JazzVinyl said:


> Does look fun! Are you turning the heater voltage down from 12 to 6 volts, to run these tubes?



The crack is already 6v. It runs the 12AU7 in 6v mode (12AU7 can be run with 12v or 6v depending on how the heaters are connected). So no voltage adjustment needed!


----------



## chrisdrop

carlman14 said:


> Here's some adapter madness for the BHC for y'all. Looks ridiculous, but the tube rolling is fun.
> 
> First: 12AU7 -> 6SN7 -> dual 6J5 -> Cunningham 6C5g tubes
> Second: 12AU7 -> 6SN7 -> dual 6J5 -> 6C4 -> Tung-Sol 6C4 tubes


Tower of (adapter) Babel. I love the 6J5/6C5 family of tubes. How do you like the 6C4s? I never thought the more modern/mini-tubes were as good, but I've not tried too hard...


----------



## carlman14

chrisdrop said:


> Tower of (adapter) Babel. I love the 6J5/6C5 family of tubes. How do you like the 6C4s? I never thought the more modern/mini-tubes were as good, but I've not tried too hard...



So far I quite like them! The Cunningham 6C5g's are a bit brighter, and the 6C4's seem to have a bit more punch in the bass. That's not a generalization though... I don't have any other pairs of either type of tube to compare them to. Just starting my single triode collection! I know Glenn is quite fond of 6C4 tubes. They do sound good.


----------



## GreenNeedle (Sep 1, 2020)

Well I am trying the Tung Sol 6sN7(GT).. Initial thoughts are that it sounds so congested with HD580 so listening with the Sextetts instead.  Soundstage is wider, separation hit and miss TBH. Lower and higher registers are much better then 12AU7.  In the centre seems that the 12AU7 controls things better.  12 AU7 cannot compete in separation (overall) nor soundstage:  +/- weigh favourably towards the 6sn7:


----------



## GreenNeedle

GreenNeedle said:


> Well I am trying the Tung Sol 6sN7(GT).. Initial thoughts are that it sounds so congested with HD580 so listening with the Sextetts instead.  Soundstage is wider, separation hit and miss TBH. Lower and higher registers are much better then 12AU7.  In the centre seems that the 12AU7 controls things better.  12 AU7 cannot compete in separation (overall) nor soundstage:  +/- weigh favourably towards the 6sn7:



I should add (as I should've before) this is listening from either PC FLAC or CD through the Topping D30.  The d30 is really good "but" the  Denon CD direct to the amp is a little mellower.  It's one of those YMMVs, however I am sticking to the new kid on the block (Topping) at the mo.


----------



## cddc

chrisdrop said:


> Tower of (adapter) Babel. I love the 6J5/6C5 family of tubes. How do you like the 6C4s? I never thought the more modern/mini-tubes were as good, but I've not tried too hard...




As far as I know, 6C4 is half of 12AU7. I bought some 6C4 tubes but not yet bought its adapter, not sure if would go this route....


----------



## PsilocybinCube

GreenNeedle said:


> Well I am trying the Tung Sol 6sN7(GT).. Initial thoughts are that it sounds so congested with HD580 so listening with the Sextetts instead.  Soundstage is wider, separation hit and miss TBH. Lower and higher registers are much better then 12AU7.  In the centre seems that the 12AU7 controls things better.  12 AU7 cannot compete in separation (overall) nor soundstage:  +/- weigh favourably towards the 6sn7:


Not sure what tube that is but the 6sn7 sounds very different from tube to tube.  The newish tung sol 6sn7 that can be found for around 25$ is ok, but there are much better options.  I'd go to the 6sn7 addicts thread for good recommendations.


----------



## cddc

GreenNeedle said:


> Well I am trying the Tung Sol 6sN7(GT).. Initial thoughts are that it sounds so congested with HD580 so listening with the Sextetts instead.  Soundstage is wider, separation hit and miss TBH. Lower and higher registers are much better then 12AU7.  In the centre seems that the 12AU7 controls things better.  12 AU7 cannot compete in separation (overall) nor soundstage:  +/- weigh favourably towards the 6sn7:



It all depends. People's gears / music genres / sound preferences / ... all come into play when choosing tubes.

I know @DenverW  and @BobMonkhouse here prefer 12AU7 to 6SN7 on their Cracks.


----------



## bagwell359 (Sep 2, 2020)

OOPS: consensus on the BH Crack site is the 6AS7G is very good in this app.  But if you have alternate take, feel free.

Specific Question: What to run with an Amperex E80CC (tall)?  Please only read/answer if you've run this tube.

I've got the stock 6080, and a Sovtek 6AS7G.  I'm sure there is better out there for the Amperex, but I don't know that what works best with the the 12AU7 will work out the same with the E80CC.  Comments.


----------



## Shane D

Are any Crack/Speedball users running the Senn HD660's on their units? I know it _should _be fine, but I was just wondering.

Also, any feedback on the Sundara's or Elex's?

I do have a tube amp now (Ear+ HDII by Mapletree Audio Design) and am thinking about picking up a BHC/Speedball. I currently have the HD600's and the DT880 (600 Ohm's). I am keeping an eye out for used T1.2's and Audio Technica R70X's.

Thanks for any feedback.


----------



## cddc

Shane D said:


> Are any Crack/Speedball users running the Senn HD660's on their units? I know it _should _be fine, but I was just wondering.
> 
> Also, any feedback on the Sundara's or Elex's?
> 
> ...




HD600/HD660/DT880 will work great on Crack.

But Sundara or any other planar or low-impedance headphones are a no-go for Crack or other OTL amps. To work with these planar or low impedance headphones, you need a transformer coupled tube amp.


----------



## Shane D

cddc said:


> HD600/HD660/DT880 will work great on Crack.
> 
> But Sundara or any other planar or low-impedance headphones are a no-go for Crack or other OTL amps. To work with these planar or low impedance headphones, you need a transformer coupled tube amp.



Thank you for the reply. I already have amps for the very efficient 'phones, I was just wondering about "mid-impedance" phones. I know planars can be problematic on tube amps.

So, NOTHING under 150 Ohm and beware of planar's.


----------



## cddc

Shane D said:


> Thank you for the reply. I already have amps for the very efficient 'phones, I was just wondering about "mid-impedance" phones. I know planars can be problematic on tube amps.
> 
> So, NOTHING under 150 Ohm and beware of planar's.




You are welcome. 

"Mid-impedance" cans should be okay with Crack. I used to think mid- to low- impedance cans won't work well on Crack, but sometime later one Crack user reported that some low-impedance Grado cans work well on his Crack too, which really surprised me. 

But for planars you definitely need some solid state amp that's capable of supplying high current swings.


----------



## PsilocybinCube

I tried some Hifiman HE560 headphones with my BHC and they sounded super smooth.  Seriously, super smooth.  No detail.  Just smooth sound with zero fidelity.  It wasn't fun.  it was like listening to a stick of butter.


----------



## DenverW (Sep 3, 2020)

cddc said:


> It all depends. People's gears / music genres / sound preferences / ... all come into play when choosing tubes.
> 
> I know @DenverW  and @BobMonkhouse here prefer 12AU7 to 6SN7 on their Cracks.



Its true, but I have some caveats.  I've found some pretty big swings in quality of certain 12au7.  The bottom of the barrel 12au7 are some of my least favorite tubes overall, while the top end are my absolute most loved.  I'd say after having tested many 6sn7, 12au7, and other types with adapters that I prefer the mid range cost 6sn7 over many if not most of the 12au7.  My current top 5 input tubes are:

1. amperex welded plate 45 degree 1940's d getter 12au7
2.  1940's victor rca 12au7 (can you believe it? an rca?! The very old 1940's are a different beast)
3.  CV6 mullard black plate (with adaper)
4.  Siemens silver plate 12au7
5.  CBS/Hytron E1148

So 3 of my top 5 are 12au7, and the other two are frankentubes.  My favorite 6sn7 is the 3 hole sylvania 'bad boy.'  I will mention that i've yet to hear both the tung sol round plate 6sn7 and the telefunken ecc802s.  Just too price prohibitive.

As far as using lower impedance headphones with the crack, its my understanding that there will be bass roll off depending on the impedance of the headphone.  So I think its certainly possible to listen to lower impedance headphones on the crack, but when you hit a certain song or type of music it will be more apparent.

@ bagwell359 I have an amperex e80cc, and I think the tube has great potential, but I'm too lazy to change the resistors to get the crack to work optimally with it.  I was just too into trying other tubes to limit myself to either 12bh7 or e80cc types.  The amperex is a rich sounding tube (to me, everything is imho!) that had great spaciousness.  Airy rich; I like it a lot.  As long as you don't pair it with anything syrupy it will work well.  5998, rca 6as7g, tung sol 6080, 421a...they all worked well.  I would say that without that resistor mod the e80cc just didnt beat out the tubes the crack is optimized for.  I'd like to one day make a three way switch for 12au7 type/12bh7/e80cc.  I've read a bit about one or two others that have done this, but the skill level/effort level is above me right now .

On a side note, I'm having to modify the base of my crack.  The kzk 100uf caps were just too big.  Luckily, my next door neighbor is a wood worker.  SCORE!


----------



## cddc

DenverW said:


> Its true, but I have some caveats.  I've found some pretty big swings in quality of certain 12au7.  The bottom of the barrel 12au7 are some of my least favorite tubes overall, while the top end are my absolute most loved.  I'd say after having tested many 6sn7, 12au7, and other types with adapters that I prefer the mid range cost 6sn7 over many if not most of the 12au7.  My current top 5 input tubes are:
> 
> 1. amperex welded plate 45 degree 1940's d getter 12au7
> 2.  1940's victor rca 12au7 (can you believe it? an rca?! The very old 1940's are a different beast)
> ...




Very nice overview of tubes for BHC!

You really scored for a good neighbor! 

I wish I could find someone like this


----------



## GreenNeedle

PsilocybinCube said:


> Not sure what tube that is but the 6sn7 sounds very different from tube to tube.  The newish tung sol 6sn7 that can be found for around 25$ is ok, but there are much better options.  I'd go to the 6sn7 addicts thread for good recommendations.



It's an NOS Tung Sol 6SN7GT.  Black base with 3226-13 also printed on the base.



DenverW said:


> Its true, but I have some caveats.  I've found some pretty big swings in quality of certain 12au7.  The bottom of the barrel 12au7 are some of my least favorite tubes overall, while the top end are my absolute most loved.  I'd say after having tested many 6sn7, 12au7, and other types with adapters that I prefer the mid range cost 6sn7 over many if not most of the 12au7.  My current top 5 input tubes are:
> 
> 1. amperex welded plate 45 degree 1940's d getter 12au7
> 2.  1940's victor rca 12au7 (can you believe it? an rca?! The very old 1940's are a different beast)
> ...



I do agree with you on the 12AU7 at least in my short experience and with no speedball added yet.  There are large differences between some of these tubes.  Stock (and least favourite) on the left to my favourite on the right:


----------



## DenverW

@GreenNeedle probably not a big deal overall, but if you’re rolling some other tube types I’d look at adding the speedball to help keep the current controlled.  Is it going to hurt anything using 6sn7 in a non speedball crack?  Probably not.  Have I done it?  Yep.  Am I more comfortable using variant tubes with speedball added? Yes 

I don’t think you’ll regret speedball.


----------



## cddc

GreenNeedle said:


> I do agree with you on the 12AU7 at least in my short experience and with no speedball added yet.  There are large differences between some of these tubes.  Stock (and least favourite) on the left to my favourite on the right:



A very nice collection of European ECC82 / 12AU7 tubes there.

I saw: GE, Mullard, Philips/Amperex, Russian new production, Tungsram, Siemens, ? No print, Thorn (Brimar?), Mazda.

I figured one of the benefits living in Europe is the easy access to those European beauties - GEC, Mullard, Amperex, Telefunken, Siemens, Valvo, Mazda, Philips, ...


----------



## GreenNeedle (Sep 4, 2020)

cddc said:


> A very nice collection of European ECC82 / 12AU7 tubes there.
> 
> I saw: GE, Mullard, Philips/Amperex, Russian new production, Tungsram, Siemens, ? No print, Thorn (Brimar?), Mazda.
> 
> I figured one of the benefits living in Europe is the easy access to those European beauties - GEC, Mullard, Amperex, Telefunken, Siemens, Valvo, Mazda, Philips, ...



The No Print is an old Tung Sol and yes the Thorn? was sold to me as a Brimar and is (currently) my second fav.  I have a few more to test out yet including a Marconi ECC 82 one that came yesterday   TBH Out of that lot I only use the Mazda and Brimar.  The Siemens is a little bright and neutral for my tastes and the Philips Miniwatt even more so.  The Russian Tung-Sol is nowhere near the old Tung-Sol (no print.)

GEC is out of my price range. lol.  I got my pair of Tung Sol 5998 for £40 (buy it now) off ebay.  They appeared while I was searching so I was on ebay at just the right time.  I wouldn;t have bought them at £100 each.


----------



## DenverW

GreenNeedle said:


> The No Print is an old Tung Sol and yes the Thorn? was sold to me as a Brimar and is (currently) my second fav.  I have a few more to test out yet including a Marconi ECC 82 one that came yesterday   TBH Out of that lot I only use the Mazda and Brimar.  The Siemens is a little bright and neutral for my tastes and the Philips Miniwatt even more so.  The Russian Tung-Sol is nowhere near the old Tung-Sol (no print.)
> 
> GEC is out of my price range. lol.  I got my pair of Tung Sol 5998 for £40 (buy it now) off ebay.  They appeared while I was searching so I was on ebay at just the right time.  I wouldn;t have bought them at £100 each.



You lucky dog!  5998 is a great tube


----------



## DenverW

Your tube porn has inspired me.  What's the point of making a collection of you can't make people jealous on the forums?    Although, there are plenty of people here that would put my collection to shame.  In order of preference from top to bottom;  12au7 favorites and power tube favorites.


----------



## GreenNeedle

DenverW said:


> You lucky dog!  5998 is a great tube



Even better at £20 each shipped   They were listed as used though and no "test readings" so how long they will last, who knows.


----------



## cddc

GreenNeedle said:


> Even better at £20 each shipped   They were listed as used though and no "test readings" so how long they will last, who knows.




At £20/ea shipped it's a steal, no matter untested or used. You really lucked out!


----------



## cddc

DenverW said:


> Your tube porn has inspired me.  What's the point of making a collection of you can't make people jealous on the forums?    Although, there are plenty of people here that would put my collection to shame.  In order of preference from top to bottom;  12au7 favorites and power tube favorites.




Another great collection of tubes!

I saw: 

Amperex, 5814A (likely RCA or GE?), Marconi, Brimar, Telefunken, Siemens, RCA, Amperex (guess from your ranking) 12AU7/ECC82's on the left, 

and Sylvania 6080 Gold Brand, Bendix 6080, GEC 6AS7G, WE 421A on the right.


----------



## GreenNeedle

There are quite a lot of tubes on the easybay at the moment that have what looks like a filler around the base and the glass.  What do you guys reckon?  Are these Frankens?  Is it just to stabilise some looseness or a leak?  What's that all about?:

https://www.ebay.co.uk/itm/KEN-RAD-...e=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649


----------



## chrisdrop

GreenNeedle said:


> There are quite a lot of tubes on the easybay at the moment that have what looks like a filler around the base and the glass.  What do you guys reckon?  Are these Frankens?  Is it just to stabilise some looseness or a leak?  What's that all about?:
> 
> https://www.ebay.co.uk/itm/KEN-RAD-JAN-CKR-6SN7GT-VT-231-Black-Glass-Valve-Tube-Used-Tested-Strong/184418833662?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649


FYI - the seller is a generally good seller. I don't know what is up with the sealant.


----------



## cddc

GreenNeedle said:


> There are quite a lot of tubes on the easybay at the moment that have what looks like a filler around the base and the glass.  What do you guys reckon?  Are these Frankens?  Is it just to stabilise some looseness or a leak?  What's that all about?:
> 
> https://www.ebay.co.uk/itm/KEN-RAD-JAN-CKR-6SN7GT-VT-231-Black-Glass-Valve-Tube-Used-Tested-Strong/184418833662?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649



The brown sealant / filler should be the aged glue from a cheap fix to the loose base years ago. 

Tube bases can become loose after decades of aging. When it happens, people normally fill some glue into the gap between the glass bottle and bakelite base to fix the problem. I had a couple of tubes that came with loose bases, and when I filled the gap with glue, I normally clean up the overflow of glue with Q-tips or towels. 

Obviously the previous owner of the tube in auction didn't clean up any overflow of glue. When the glue oxidized years later, it became brown (or possibly the glue was brown itself). 

Anyway, I personally think the previous owner did a really bad job on fixing the loose base, but the seller seems to be a good one from his track record.


----------



## cddc

BTW, you can clean up the mess with a blade. I did it once on a tube with some nasty brownish aged glue like that.


----------



## GreenNeedle

cddc said:


> BTW, you can clean up the mess with a blade. I did it once on a tube with some nasty brownish aged glue like that.


They all went past my budget anyway.  I was looking at the Ken Rad VT231 6SN7 and a few came up (mostly from the one seller) but they all went a little too high for me.  I don't pay £50+ for a tube.


----------



## cddc

These are among the popular 6SN7 tubes, famous for their strong bass performance.

But with patience and/or good luck you can score some under £40, I think.


----------



## DenverW

You mean to say that you don’t pay that for a tube...yet!  once the fall down the rabbit hole begins who knows where it ends!  I used to have price limits too


----------



## GreenNeedle

DenverW said:


> You mean to say that you don’t pay that for a tube...yet!  once the fall down the rabbit hole begins who knows where it ends!  I used to have price limits too


Most I've paid for an individual tube was £36 (inc shipping) for the Siemens ECC82 silver plates.  Pity because it is one I will end up selling on.


----------



## DenverW

So the new wood base is built and its perfect.  I need to stain or paint it, but the caps fit perfectly as long as I lower the top plate directly down (instead of at an angle).  I'll put up a picture tomorrow, basicially its identical to the original base but with a 3 1/2 inch section widened out of the wood on the sides.  Have some listening to catch up with....


----------



## JamieMcC

Fyi afaik Tungsram & Siemens were the only manufacturers of the E80cc  all the rest are rebranding sourced from Siemens or Tungsram factories. Don't pay over the top for other branded E80cc. Essentially you see variations of smooth and holed plates with halo or foil getters.


----------



## DenverW

JamieMcC said:


> Fyi afaik Tungsram & Siemens were the only manufacturers of the E80cc  all the rest are rebranding sourced from Siemens or Tungsram factories. Don't pay over the top for other branded E80cc. Essentially you see variations of smooth and holed plates with halo or foil getters.



my knowledge isn’t perfect by any means, but I was under the impression that Phillips was one of the original manufacturers in the 50s, and that the Siemens tubes were rebranded ring getter later version Phillips?


----------



## Tom-s

JamieMcC said:


> Fyi afaik Tungsram & Siemens were the only manufacturers of the E80cc  all the rest are rebranding sourced from Siemens or Tungsram factories. Don't pay over the top for other branded E80cc. Essentially you see variations of smooth and holed plates with halo or foil getters.



In my collection there's none Siemens/Halske (Munich) factory build E80CC. I think @DenverW is right.

Most of what's for sale are E80CC made in Heerlen (Netherlands; Delta code). Here's a lineup with labels from the Heerlen factory.




If you source pinched waist E80CC's you can find Eindhoven versions aswel. Supposedly also Hamburg, not in my collection yet.



Oh, and for something special! Here's a picture i took this summer.
Who can guess what Philips factory this was?
On the picture you see the length of the cafeteria! With the typical Philips factory type windows.

Yes I'm a fanatic.


----------



## DenverW

Here is a picture of the wood base that I mentioned.  I haven't stained it yet.  A portion of the side was cut out to make room for the caps, which were just a hair too big to sit comfortably.


----------



## GreenNeedle

DenverW said:


> Here is a picture of the wood base that I mentioned.  I haven't stained it yet.  A portion of the side was cut out to make room for the caps, which were just a hair too big to sit comfortably.


 Can you do for me a "eye level" with plate photo from the back?  So I can see how you've mounted and wired the choke.  I have one on its way to me.  I'll not mention the crees that are also on their way because the PCB boards are unobtainium so I am hoping to copy someone else's solution of a "no board" fitment.


----------



## DenverW

GreenNeedle said:


> Can you do for me a "eye level" with plate photo from the back?  So I can see how you've mounted and wired the choke.  I have one on its way to me.  I'll not mention the crees that are also on their way because the PCB boards are unobtainium so I am hoping to copy someone else's solution of a "no board" fitment.




You mean this pcb board?  https://www.partsconnexion.com/PCB-77727.html

They also have one thats built with cree diodes already, but that ones 20 bucks as opposed to 2.  When I start to stain the wood base I'll take a picture for you.  I can tell you that I mounted it behind the transformer (instead of over it) closest to the rear of the crack.  I used two screws and stand offs.  The only issue I had was that I put one of the screws too close to the transformer, so the top part of the screw brushed against the transformer on the top of the panel.  Basically, just don't forget that the top of the screw is bigger than the rest .  Rookie mistake by me!  Cree diodes was a very simple upgrade, and honestly don't even need a stand off because they weigh nothing and the wires just hold them in place.


----------



## GreenNeedle

DenverW said:


> You mean this pcb board?  https://www.partsconnexion.com/PCB-77727.html
> 
> They also have one thats built with cree diodes already, but that ones 20 bucks as opposed to 2.  When I start to stain the wood base I'll take a picture for you.  I can tell you that I mounted it behind the transformer (instead of over it) closest to the rear of the crack.  I used two screws and stand offs.  The only issue I had was that I put one of the screws too close to the transformer, so the top part of the screw brushed against the transformer on the top of the panel.  Basically, just don't forget that the top of the screw is bigger than the rest .  Rookie mistake by me!  Cree diodes was a very simple upgrade, and honestly don't even need a stand off because they weigh nothing and the wires just hold them in place.



Yep that's the one.  It was out of stock when I looked at the weekend.......Problem is I then read on in the bottlehead threads and they charge £15 or something silly shipping for the $2 board.  I've bought the diodes already so I'm going to try the non board solution and see if I can burn the house down. lol.


----------



## GreenNeedle

Or maybe not.  Turns out shipping + board would be about £8 which isn't that bad.  Might buy the board now. lol


----------



## cddc

DenverW said:


> Here is a picture of the wood base that I mentioned.  I haven't stained it yet.  A portion of the side was cut out to make room for the caps, which were just a hair too big to sit comfortably.



Brilliant idea to carve out a groove on the wood to make the fit!

I was wondering how you would make the chassis wider, as the top plate is fixed in size. But now I see it.

How did your neighbor cut the corners and the grooves, did he use any machine? They are very smooth, definitely professional grade!


----------



## cddc (Sep 7, 2020)

GreenNeedle said:


> Can you do for me a "eye level" with plate photo from the back?  So I can see how you've mounted and wired the choke.  I have one on its way to me.  I'll not mention the crees that are also on their way because the PCB boards are unobtainium so I am hoping to copy someone else's solution of a "no board" fitment.




Here is a pic that I collected earlier (from members here), which shows how the choke would stand behind the transformer.





I always wanted to do these mods, but my soldering skill sucks, so never dared to do them. I hope to pick up a soldering station someday and practice on my soldering skills...sigh 😆


----------



## GreenNeedle

cddc said:


> Here is a pic that I collected earlier (from members here), which shows how the choke would stand behind the transformer.
> 
> 
> 
> I always wanted to do these mods, but my soldering skill sucks, so never dared to do them. I hope to pick up a soldering station someday and practice on my soldering skills...sigh 😆



Thanks for that.  From what I read these are 2 very easy mods the cree board you are soldering away from the Crack anyway so get that right away from the "money" and then it's just wire it in like the rest of the build.  The bit I am more worried about is screws showing on the top.  I'm all for minimalism so with the cree ones would be looking to glue them and probably try and hide the choke ones behind the transformer.  Depends how heavy it is I suppose.


----------



## cddc

For the crees I think it's okay to glue the board to the plate with some sticks, or use nothing as @DenverW suggested because the stock Crack wires should be strong enough to hold the board and crees in place. For the choke, I personally think it might be not safe to use sticks and glue to hold it in place because of the high temperature and heavy weight. I think it's safer to use some screws there, though I'm all for minimalism myself too.


----------



## cddc

For the choke installation, one way to avoid drilling additional holes on the plate, that I can think of, is to utilize the grounding screw and one of the screws that hold the transformer in place. 

I think you can possibly make some metal rack for the choke using some metal stripes, and fix the stripes to the plate by the grounding screws and one of the transformer screws.


----------



## PsilocybinCube

DenverW said:


> Here is a picture of the wood base that I mentioned.  I haven't stained it yet.  A portion of the side was cut out to make room for the caps, which were just a hair too big to sit comfortably.


When does this go up for sale?


----------



## DenverW

PsilocybinCube said:


> When does this go up for sale?



lol!  Perhaps once I have a crackatwoa?  Help me find one!  Bottlehead threw up three kits on sale and I missed it, barely.

@GreenNeedle i would strongly recommend against glue for the choke.  It’s very heavy glue would fail at some point with the heat.  The screws are behind the transformer so arent very visible on the top.  Might as we’ll get used to adding some screws for when you upgrade those output caps!


----------



## DenverW

GreenNeedle said:


> Can you do for me a "eye level" with plate photo from the back?  So I can see how you've mounted and wired the choke.  I have one on its way to me.  I'll not mention the crees that are also on their way because the PCB boards are unobtainium so I am hoping to copy someone else's solution of a "no board" fitment.




Here is a ground level pic of the choke installation, hope it helps.  The wood base was made by machinery from my neighbor, those clean lines are beyond my skill level.  I'm more hacksaw Jim Dugan than black swan.  Now its time for the part that I've screwed up every time i've tried: staining.  Wish me luck


----------



## PsilocybinCube

DenverW said:


> lol!  Perhaps once I have a crackatwoa?  Help me find one!  Bottlehead threw up three kits on sale and I missed it, barely.
> 
> @GreenNeedle i would strongly recommend against glue for the choke.  It’s very heavy glue would fail at some point with the heat.  The screws are behind the transformer so arent very visible on the top.  Might as we’ll get used to adding some screws for when you upgrade those output caps!


Just kidding really.  I am still loving the Crack I bought from you the first time.  I will have my own new base to show off soon I'm building from walnut.

I do sort of blame you (and give you credit) for my very healthy tube addiction.


----------



## DenverW

Once the addiction really hits you'll sell that one and build one .  It was honestly worth going through the experience of building one and modding it.  Not just the 'pride' factor of creating something yourself, but I'm much more confident in troubleshooint.  I had a channel go out and I was able to figure out what the problem was and fix it (wire had come loose).  Pass the sickness on to the next person...


----------



## GreenNeedle

DenverW said:


> Here is a ground level pic of the choke installation, hope it helps.  The wood base was made by machinery from my neighbor, those clean lines are beyond my skill level.  I'm more hacksaw Jim Dugan than black swan.  Now its time for the part that I've screwed up every time i've tried: staining.  Wish me luck


Good luck.  I never have much luck with staining either.


----------



## cddc

DenverW said:


> Here is a ground level pic of the choke installation, hope it helps.  The wood base was made by machinery from my neighbor, those clean lines are beyond my skill level.  I'm more hacksaw Jim Dugan than black swan.  Now its time for the part that I've screwed up every time i've tried: staining.  Wish me luck




LOL...Hacksaw Jim   🤣🤣🤣

I think you can possibly give the staining job to your neighbor as well, as he's good at wood works.


----------



## cddc

DenverW said:


> Once the addiction really hits you'll sell that one and build one .  It was honestly worth going through the experience of building one and modding it.  Not just the 'pride' factor of creating something yourself, but I'm much more confident in troubleshooint.  I had a channel go out and I was able to figure out what the problem was and fix it (wire had come loose).  Pass the sickness on to the next person...




Wait....you mean there can be building addiction in addition to tube addiction? I think I should give up the idea of getting a soldering station....🤪

Just kidding


----------



## GreenNeedle

so I have all my parts other than the PCB board (which I did order in the end.)  What order do you think I should do these upgrades in?  I want to do each individually so I can assess any differences.  See if I like or dislike them.

Should I do speedball first followed by crees and then choke?

I've also finished my power lead home made version of the bottlehead one so will test that out before the above.


----------



## DenverW

GreenNeedle said:


> so I have all my parts other than the PCB board (which I did order in the end.)  What order do you think I should do these upgrades in?  I want to do each individually so I can assess any differences.  See if I like or dislike them.
> 
> Should I do speedball first followed by crees and then choke?
> 
> I've also finished my power lead home made version of the bottlehead one so will test that out before the above.



Speedball first, because you have specific voltage tests after installing it, and it gives the largest overall change both to space in the unit and overall sound.


----------



## cddc

GreenNeedle said:


> so I have all my parts other than the PCB board (which I did order in the end.)  What order do you think I should do these upgrades in?  I want to do each individually so I can assess any differences.  See if I like or dislike them.
> 
> Should I do speedball first followed by crees and then choke?
> 
> I've also finished my power lead home made version of the bottlehead one so will test that out before the above.




Agree with @DenverW . Speedball 1st, choke 2nd, and crees 3rd.

BTW, where did you source your choke and crees? What are the specs on them (I have no idea about the specs )? Thanks.


----------



## GreenNeedle

cddc said:


> Agree with @DenverW . Speedball 1st, choke 2nd, and crees 3rd.
> 
> BTW, where did you source your choke and crees? What are the specs on them (I have no idea about the specs )? Thanks.



Choke and crees: Mouser.  They came in 3 days after buying.

I'm going to have to wait to do all this.   My Noval socket is causing some crackling.  No idea if it is a solder issue or the socket itself.


----------



## GreenNeedle

cddc said:


> BTW, where did you source your choke and crees? What are the specs on them (I have no idea about the specs )? Thanks.



Sorry didn't reply on specs.  No idea on specs, I copied other links from posts on BH crack site.  I bought these:
https://www.mouser.co.uk/ProductDet...T0O8Zu9aP3g==&countrycode=GB&currencycode=GBP
https://www.mouser.co.uk/ProductDet...fQT7VqjsiJw==&countrycode=GB&currencycode=GBP


----------



## DenverW

Crackling is usually a solder issue or a tube issue.  Try Other tubes, and if it remains the same it’s probably solder.  Most crack issues are solder .


----------



## cddc

GreenNeedle said:


> Sorry didn't reply on specs.  No idea on specs, I copied other links from posts on BH crack site.  I bought these:
> https://www.mouser.co.uk/ProductDetail/triad-magnetics/c-7x/?qs=/PiZ59IM4y3T0O8Zu9aP3g==&countrycode=GB&currencycode=GBP
> https://www.mouser.co.uk/ProductDet...fQT7VqjsiJw==&countrycode=GB&currencycode=GBP




Cool, thank you very much for the links!

Same as @DenverW , I think it's best to replace the current driver tube with a different one first. If the crackling is still there, we can conclude that it's not a bad tube problem, and you can proceed to reflowing the joints on your Noval socket.


----------



## GreenNeedle

I tried several tubes already before the last post.  All had the crackling.  I've had a bit of a mare since then. lol.  I decided to reflow some wires and then I had some low level hum.........so I decided to tighten up the screws thiking maybe that might help...........and some enamel chipped off round the screws..........so I've had to take it all off and respray the top.  Happy days


----------



## DenverW

@GreenNeedle Hopefully it won't be much more of an issue and you can get back to the music.  Did you do any voltage checks after you redid the solder?  I admit I've skipped that step before, and every time I have I usually end up regretting it.

Here is a question to the group:  how many people get the background tap tap tap from other electronics (such as internet) that might be nearby.  So I do get this intermittently, and I have a truly ghetto solution.  I've put a small wall of tin foil up between the crack and the router.  I've noticed that its actually the top of the crack (the tubes) that needs the tin foil blocking.  When I folded the tin foil in half and placed it on the side of the frame i'd getting the background sound.  I'm thinking of trying some DIY tube shields.  Anyone done this?


----------



## jivex5k

I recently purchased this amp after asking for some advice here. I'm incredibly happy with this decision and really enjoyed building it. I was happy to see a huge thread here dedicated to the amp, very cool to see the various mods and upgrades. It's been fun to slowly upgrade this amp. I installed speedball, a mod with the ground lug to filter PC noise (worked great), and built that special power cable.

I installed a new pot and knob today, came out nice. I ended up going with the audio note since it had solder lugs, and figured what the hell I'll splurge a little. The new pot fixed the audio balance at low levels so that's cool. I was at a loss for what to upgrade, glad I found this thread, going to find some inspiration.


----------



## DenverW

It looks great!  Prepare to fall into the tube and upgrade pit!  Output caps, Cree diodes!  Chokes!  Gec tubes!


----------



## cddc

jivex5k said:


> I recently purchased this amp after asking for some advice here. I'm incredibly happy with this decision and really enjoyed building it. I was happy to see a huge thread here dedicated to the amp, very cool to see the various mods and upgrades. It's been fun to slowly upgrade this amp. I installed speedball, a mod with the ground lug to filter PC noise (worked great), and built that special power cable.
> 
> I installed a new pot and knob today, came out nice. I ended up going with the audio note since it had solder lugs, and figured what the hell I'll splurge a little. The new pot fixed the audio balance at low levels so that's cool. I was at a loss for what to upgrade, glad I found this thread, going to find some inspiration.




Excellent work!

I love the legs, where can I find them?


----------



## cddc (Sep 14, 2020)

DenverW said:


> @GreenNeedle Hopefully it won't be much more of an issue and you can get back to the music.  Did you do any voltage checks after you redid the solder?  I admit I've skipped that step before, and every time I have I usually end up regretting it.
> 
> Here is a question to the group:  how many people get the background tap tap tap from other electronics (such as internet) that might be nearby.  So I do get this intermittently, and I have a truly ghetto solution.  I've put a small wall of tin foil up between the crack and the router.  I've noticed that its actually the top of the crack (the tubes) that needs the tin foil blocking.  When I folded the tin foil in half and placed it on the side of the frame i'd getting the background sound.  I'm thinking of trying some DIY tube shields.  Anyone done this?




Too bad you have the RF interference issue. My Crack is also very close to my router (about 1.5m), but I didn't have the tap tap tap issue.

For the 12AU7 tube you can find aluminum shields like this:





But I am not sure if there are similar shields for the 6080/6AS7G tube.


----------



## cddc

DenverW said:


> @GreenNeedle Hopefully it won't be much more of an issue and you can get back to the music.  Did you do any voltage checks after you redid the solder?  I admit I've skipped that step before, and every time I have I usually end up regretting it.
> 
> Here is a question to the group:  how many people get the background tap tap tap from other electronics (such as internet) that might be nearby.  So I do get this intermittently, and I have a truly ghetto solution.  I've put a small wall of tin foil up between the crack and the router.  I've noticed that its actually the top of the crack (the tubes) that needs the tin foil blocking.  When I folded the tin foil in half and placed it on the side of the frame i'd getting the background sound.  I'm thinking of trying some DIY tube shields.  Anyone done this?




Another solution to get rid of the RF interference issue is to use Faraday cage.





You can find some metal mesh, and DIY a cage to cover the whole Crack or just the tube section. It works best if you connect the Faraday cage to the ground - maybe connect it to the grounding nut on your Crack.


----------



## jivex5k

DenverW said:


> It looks great!  Prepare to fall into the tube and upgrade pit!  Output caps, Cree diodes!  Chokes!  Gec tubes!


Thanks 



cddc said:


> Excellent work!
> 
> I love the legs, where can I find them?


Thanks 
I got them on Amazon. Just looked up jewelry box feet. They scratch stuff up though, I really need some rubber pads for them.


----------



## cddc

jivex5k said:


> Thanks
> 
> 
> Thanks
> I got them on Amazon. Just looked up jewelry box feet. They scratch stuff up though, I really need some rubber pads for them.



Cool, thank you very much!

That's indeed a very innovative idea


----------



## jivex5k

DenverW said:


> Here is a question to the group:  how many people get the background tap tap tap from other electronics (such as internet) that might be nearby.  So I do get this intermittently, and I have a truly ghetto solution.  I've put a small wall of tin foil up between the crack and the router.  I've noticed that its actually the top of the crack (the tubes) that needs the tin foil blocking.  When I folded the tin foil in half and placed it on the side of the frame i'd getting the background sound.  I'm thinking of trying some DIY tube shields.  Anyone done this?



I was getting a lot of noise from my PC, I installed two diodes from the ground on the IEC to the ground lug in place of the buss wire, it's dead silent now.
PB made a post about it here: https://forum.bottlehead.com/index.php?topic=11676.0

Sounds like your noise is RFI though.


----------



## cddc

That's also a very promising solution. 

I haven't installed that solution yet, coz it came up just recently (maybe the end of last year). Saw it on the BH forum, but almost forgot about it.


----------



## GreenNeedle

DenverW said:


> @GreenNeedle Hopefully it won't be much more of an issue and you can get back to the music.  Did you do any voltage checks after you redid the solder?  I admit I've skipped that step before, and every time I have I usually end up regretting it.



Alas I didn't.  It all tested fine when I first did it and I was just reflowing things so didn't deem it necessary.  When I put it all back together I will do the checks.

Before I re-flowed though I tested the power cord I made.  No inputs just phones into the unit.  With the old power cord (from a 5A LED power supply) it was pretty quiet but you could hear hum at near max to max volume.  With new power cord, silent all the way to max.  After reflow............humm all the way from bottom. lol.  Sounds to me like ground.  Like the humm you get plugging a guitar into an amp with a dodgy lead.  Like the beginning of Oasis-Cigarettes and alcohol.



> Here is a question to the group:  how many people get the background tap tap tap from other electronics (such as internet) that might be nearby.  So I do get this intermittently, and I have a truly ghetto solution.  I've put a small wall of tin foil up between the crack and the router.  I've noticed that its actually the top of the crack (the tubes) that needs the tin foil blocking.  When I folded the tin foil in half and placed it on the side of the frame i'd getting the background sound.  I'm thinking of trying some DIY tube shields.  Anyone done this?



I get this.  My phone's charger base is above the Crack.  My solution is to turn the phone off. lol.  Works a treat and no interruptions either.

Is it a router you are talking about or wi-fi?  If router, can't you shield around that and hide it away somewhere?


----------



## jivex5k

GreenNeedle said:


> Alas I didn't.  It all tested fine when I first did it and I was just reflowing things so didn't deem it necessary.  When I put it all back together I will do the checks.
> 
> Before I re-flowed though I tested the power cord I made.  No inputs just phones into the unit.  With the old power cord (from a 5A LED power supply) it was pretty quiet but you could hear hum at near max to max volume.  With new power cord, silent all the way to max.  After reflow............humm all the way from bottom. lol.  Sounds to me like ground.  Like the humm you get plugging a guitar into an amp with a dodgy lead.  Like the beginning of Oasis-Cigarettes and alcohol.
> 
> ...


Double check 3L, seems to be a troublesome terminal related to ground issues. Here's a ground connection check guide too: https://forum.bottlehead.com/index.php?topic=4812.0
It doesn't mention the grounded pads on the speedball upgrade though.


----------



## DenverW

GreenNeedle said:


> Alas I didn't.  It all tested fine when I first did it and I was just reflowing things so didn't deem it necessary.  When I put it all back together I will do the checks.
> 
> Before I re-flowed though I tested the power cord I made.  No inputs just phones into the unit.  With the old power cord (from a 5A LED power supply) it was pretty quiet but you could hear hum at near max to max volume.  With new power cord, silent all the way to max.  After reflow............humm all the way from bottom. lol.  Sounds to me like ground.  Like the humm you get plugging a guitar into an amp with a dodgy lead.  Like the beginning of Oasis-Cigarettes and alcohol.
> 
> ...



Its my wi-fi, and unfortunately due to layout its got to go about 4 feet away from my amps.  I'll sort it out eventually.  Until now its the ghetto tin foil solution .


----------



## tintinsnowydog

So I just picked these up locally for the astonishing price of $9 AUD per tube. Very detailed but still smooth presentation, and one of the most unique midrange presentations I've heard. Treble is strong, pairs great with HD800 on classical music(incredible soundstage), though some hi-hats did stick out a bit. HD650 even better. Haven't tried out other power tube combinations, but I predict it'll pair well with a slower 6080; currently have a raytheon 6080 graphite plates in. Tonight will be a good night


----------



## jivex5k (Sep 18, 2020)

Ordered a couple 12au7 tubes from ebay, got a bugle boy and a mullard.

It's strange, some mullards sell for around 500 bucks, but I picked one up for 30 and it's NOS.
Same with the bugle boy, I see some way higher priced but I got mine for 25.

https://www.ebay.com/itm/254626346257
https://www.ebay.com/itm/282981215782

I've been reading up on tubes and stuff, it's a lot to take in, but I've come to a few conclusions:

1. Input tube affects audio more than power tube. (Except when they don't)
2. Mullards sound good as input tube. (If it's NOS)
3. Bugle Boy has a cool name and logo.
4. Don't pay more than 50 bucks for a tube.
5. Unless you've had a couple drinks.


----------



## PsilocybinCube

jivex5k said:


> Ordered a couple 12au7 tubes from ebay, got a bugle boy and a mullard.
> 
> It's strange, some mullards sell for around 500 bucks, but I picked one up for 30 and it's NOS.
> Same with the bugle boy, I see some way higher priced but I got mine for 25.
> ...


Drinking and buying tubes is great fun but horrible for your bank account.


----------



## DenverW

Guess what?  Cracktember sale just started on the 18th.  $100 of crack and $15 off speedball.  315 for speedball crack?  Ridiculous!!!!

Now if they’d only put the crackatwoa on sale!


----------



## DenverW

jivex5k said:


> Ordered a couple 12au7 tubes from ebay, got a bugle boy and a mullard.
> 
> It's strange, some mullards sell for around 500 bucks, but I picked one up for 30 and it's NOS.
> Same with the bugle boy, I see some way higher priced but I got mine for 25.
> ...



Great post!  I'm sure we all have our own opinions on this, and we're not shy here .  I can respond to several of those numbers at once: it depends on the tube.  I was a believer in input doing more than power tubes to affect sound...until I tried some big boys.  My personal opinion is that when I was running mid to lower cost tubes, it was more about synergy than the tubes themselves.  This is a generalization, of course.  The rca 6as7g sounded good with this, not good with that.  Tung sol mouse ears was great with this, too clinical for that.

Enter something like the western electric 421A.  It really doesnt matter what I plug into the input tube, the crack sounds amazing with this tube.  It pairs with everything I've tried it with.  Same thing when I paired my top input tube with different power tubes.  Everything sounded great, from the stock tube I got with the crack to high end power tubes.  So do I agree with not spending more than 50 for a tube?  Nope.  

But do you have to?  You can do cheap and really nice upgrades to the crack for really small amounts.  A choke, cree diodes, and an alps blue pot should cost under 50 together, and give more improvement than you'd get from a $50 dollar tube.  KZK white line 100 uf caps were only 20 apiece on ebay with negotiation (although it took 3 #(&#$*@$ months for them to arrive!).

But what do you do when you've done every upgrade under the sun?  You've tried all different types of adapters?  That haunting melody you hear is the sound of top end tubes .  I can only shake my head in envy seeing someone who can hear the crack and NOT be tempted to try better and better tubes with it.

I didn't have that self control.  I only console myself knowing I can always sell them, or use them in other amps in the future, like my one day crackatwoa.


----------



## jivex5k

The mullard tube, I swear it sounds fuller than the baldwin the crack shipped with. Then I have an electro-harmonix ECC82 that sounds harsh, don't like it at all. Bugle boy should be here in a week or so.

I wonder how much of this is just the placebo effect.

Microphonics are one thing, easy to tell of course, but these subtle differences in warmth and clarity could all be in my head.


----------



## John Massaria

I have my Crack with SB and its great but I was wondering if I maybe drained my power tube too much by leaving amp on for a week or so- I can't recall but now I noticed a hum when amp volume is above 1:00 - do all BH have hum while using a HP like HD600?


----------



## cddc (Sep 25, 2020)

tintinsnowydog said:


> So I just picked these up locally for the astonishing price of $9 AUD per tube. Very detailed but still smooth presentation, and one of the most unique midrange presentations I've heard. Treble is strong, pairs great with HD800 on classical music(incredible soundstage), though some hi-hats did stick out a bit. HD650 even better. Haven't tried out other power tube combinations, but I predict it'll pair well with a slower 6080; currently have a raytheon 6080 graphite plates in. Tonight will be a good night




You really had a steal!

I wish I could find some local store selling TF's for that low 

You really scored!


----------



## cddc

jivex5k said:


> The mullard tube, I swear it sounds fuller than the baldwin the crack shipped with. Then I have an electro-harmonix ECC82 that sounds harsh, don't like it at all. Bugle boy should be here in a week or so.
> 
> I wonder how much of this is just the placebo effect.
> 
> Microphonics are one thing, easy to tell of course, but these subtle differences in warmth and clarity could all be in my head.




This is not a placebo effect. 

Tubes from different brands do have their own unique sound due to different materials / technologies they used. This is sometimes called "house sound" 

Mullard is famous for their lush mids, Sylvania is normally more on the neutral side, and new production tubes are just a pure waste of money, IMO.


----------



## cddc

John Massaria said:


> I have my Crack with SB and its great but I was wondering if I maybe drained my power tube too much by leaving amp on for a week or so- I can't recall but now I noticed a hum when amp volume is above 1:00 - do all BH have hum while using a HP like HD600?




Nope, BHC doesn't feature humming issues.

Tubes are like light bulbs, they have a life span. Normally a brand new tube will last 5k to 10k hours. So it will be a bad habit to leave your tube amps on all the time, coz the tubes will consume very fast. It's also not a good habit to turn on and off your tube amps frequently (like many times within an hour).

In your case you might have depleted tube(s), which possibly caused the hum. If you have some spare tubes, just replace the old ones to see if the hum will go away.


----------



## cddc

John Massaria said:


> I have my Crack with SB and its great but I was wondering if I maybe drained my power tube too much by leaving amp on for a week or so- I can't recall but now I noticed a hum when amp volume is above 1:00 - do all BH have hum while using a HP like HD600?




I noticed that volume at 1pm is a little bit high, I normally listen to my Crack with SB around 9-10am.

If your amp has no humming issues at normal volume, it's just fine. Don't bother with hum at high volume.

A low tube can just work fine if it doesn't make noises or cause deterioration in sound.


----------



## John Massaria

Thank u!


----------



## DenverW

@John Massaria after you confirm or deny that it’s the tube by swapping out tubes, I would also recommend doing a new voltage check as well as giving solder points a once over.

This will help identify if there are any non tube related issues through the voltage check, and most likely fix them through solder check.


----------



## tintinsnowydog (Sep 27, 2020)

cddc said:


> You really had a steal!
> 
> I wish I could find some local store selling TF's for that low
> 
> You really scored!



Was from a local guy, untested, but pulled out of old testing equipment that was barely used. All sound fine and no issues so far!


I have found the TF 12AU7 to be the most detailed and punchy 12AU7 by far. Pairing with a warm power tube (Mullard 6080, RCA 6AS7) actually cancels outits abilities a little too much for my liking. Naturally, the TF's go perfectly with the expensive trio; GEC 6AS7 (slightly warmer presentation with no loss in details, best to my ears), TS 5998 (balanced with a touch of warmth, treble can get a bit hot with HD800 my only complaint but otherwise as good as GEC) and graphite plate 6080 (extremely punchy and dynamic, but the with a bit of recess in the mids and often treble gets a bit too bright).

Have really enjoyed the BHC, the speedball took some time to adjust to from my warmer LF339 amp (or maybe it was just everything burning in ?) but everything is sounding super dynamic now. After waiting over a month, I have had over 15 different 12AU7, 6CG7 and 6SN7 finally show up from UK and US; damn these are fun to collect and so much more affordable than the power tubes! Will be rolling through them slowly and posting some detailed impressions. Will use the HD800 and TS6080 power tube as my favourite neutral combo; was considering using a Cetron 7236 but it is just too bright for my ears with the HD800 for extended listening.

At the current moment, I have to say the 6SN7 family is vastly superior to 12AU7; considering rewiring the Crack to a permanent octal input. Strongly recommend anyone who wants  a less harsh, more linear sound to try a 6SN7 with adaptor. xulingmrs on our favourite online bidding platform makes brilliant quality adaptors for a very reasonable price, have used 5 different adaptors from her and all have been silent, sturdy and fully functional.


----------



## DenverW

tintinsnowydog said:


> Was from a local guy, untested, but pulled out of old testing equipment that was barely used. All sound fine and no issues so far!
> 
> 
> I have found the TF 12AU7 to be the most detailed and punchy 12AU7 by far. Pairing with a warm power tube (Mullard 6080, RCA 6AS7) actually cancels outits abilities a little too much for my liking. Naturally, the TF's go perfectly with the expensive trio; GEC 6AS7 (slightly warmer presentation with no loss in details, best to my ears), TS 5998 (balanced with a touch of warmth, treble can get a bit hot with HD800 my only complaint but otherwise as good as GEC) and graphite plate 6080 (extremely punchy and dynamic, but the with a bit of recess in the mids and often treble gets a bit too bright).
> ...



I agree with so much of this post .  I also was not a fan of the 7236, love the TF smooth plate (look for ones with champagne colored inner rods) and xulingmrs is my 'go to' adapter maker.

For fun, I would try the 7193 to 12au7 adapter.  Looks like a science project, sounds great.  Lets you use 7193, e1148, cv6 tubes ( you have to change the top connectors for the last two i believe).  Fun, and tubes are not expensive for the sound quality.

Now, if only I could convince you of the superiority of the 12au7.....


----------



## tintinsnowydog

DenverW said:


> I agree with so much of this post .  I also was not a fan of the 7236, love the TF smooth plate (look for ones with champagne colored inner rods) and xulingmrs is my 'go to' adapter maker.
> 
> For fun, I would try the 7193 to 12au7 adapter.  Looks like a science project, sounds great.  Lets you use 7193, e1148, cv6 tubes ( you have to change the top connectors for the last two i believe).  Fun, and tubes are not expensive for the sound quality.
> 
> Now, if only I could convince you of the superiority of the 12au7.....



Having read through the BHC tube rolling thread on their forum, I do recall seeing mention of the 7193 with adaptors only a couple of times. They should be cheap right? Looking at past sales they seem to be going at an acceptable but not so cheap price! Will investigate further, certainly look funky. Now I wonder what other oddball tubes the crack can take with adaptors...


----------



## GreenNeedle

cddc said:


> I noticed that volume at 1pm is a little bit high, I normally listen to my Crack with SB around 9-10am.
> 
> If your amp has no humming issues at normal volume, it's just fine. Don't bother with hum at high volume.
> 
> A low tube can just work fine if it doesn't make noises or cause deterioration in sound.



This will depend on where you have stuck the 0 point of the knob on.  Your 9-10am might be different to someone elses.  This of course also assumes that pot is stock, "upgrades" might have nearer to a full sweep from 0-max.

On mine I have the knob set dead centre so that 0 and max are at 6.35 and 5.25 respectively.  I listen to Sextetts at 1-2 o clock, HD580s at 11-12.30.  That is with a TungSol 5998 in which noticably louder than the stock GE.  At least 1 hour marker louder!!!

I do like to listen at loud volume though.


----------



## cddc

That's true, the various volume pots and dac output levels all affect the pot position. I personally think 8am-2pm should be a good usable range, otherwise the pot might be not suitable for the amp.

More precisely I normally listen to music around 65 - 75 dB's. Anything above 85 dB's will hurt your hearing, and hearing loss is irreversible. So guys pay attention to your volumes


----------



## cddc

tintinsnowydog said:


> Was from a local guy, untested, but pulled out of old testing equipment that was barely used. All sound fine and no issues so far!
> 
> 
> I have found the TF 12AU7 to be the most detailed and punchy 12AU7 by far. Pairing with a warm power tube (Mullard 6080, RCA 6AS7) actually cancels outits abilities a little too much for my liking. Naturally, the TF's go perfectly with the expensive trio; GEC 6AS7 (slightly warmer presentation with no loss in details, best to my ears), TS 5998 (balanced with a touch of warmth, treble can get a bit hot with HD800 my only complaint but otherwise as good as GEC) and graphite plate 6080 (extremely punchy and dynamic, but the with a bit of recess in the mids and often treble gets a bit too bright).
> ...




You are spot on regarding the tubes. TF is a tube with super technicalities, albeit a little bit sterile/dry. Definitely need some warmer power tubes to pair with, Mullard could be a good candidate. RCA 6AS7G is a warm tube, but it's a crap right there, will definitely blur the super clarity coming out of the TF


----------



## cddc

I am amazed how the forum purifies our wording by changing s h * t to crap automatically without a notice...lol


----------



## cddc

DenverW said:


> I agree with so much of this post .  I also was not a fan of the 7236, love the TF smooth plate (look for ones with champagne colored inner rods) and xulingmrs is my 'go to' adapter maker.
> 
> For fun, I would try the 7193 to 12au7 adapter.  Looks like a science project, sounds great.  Lets you use 7193, e1148, cv6 tubes ( you have to change the top connectors for the last two i believe).  Fun, and tubes are not expensive for the sound quality.
> 
> Now, if only I could convince you of the superiority of the 12au7.....




So I don't attempt to convince you 7236 is a good tube, and you don't attempt to convince me 12AU7 is a better tube, and we call it a deal? ...LOL


----------



## cebuboy

I think this is as far I can go with modding the crack..
KZK caps for coupling and bypass
Cree schottkey diodes
Alps blue velvet pot
Triad choke, surprised to see this made in my country  so it just made a homecoming haha

So far I think I like the sound more before the cree diodes and choke. Now it sounds solid stateish...


----------



## PsilocybinCube

tintinsnowydog said:


> Was from a local guy, untested, but pulled out of old testing equipment that was barely used. All sound fine and no issues so far!
> 
> 
> I have found the TF 12AU7 to be the most detailed and punchy 12AU7 by far. Pairing with a warm power tube (Mullard 6080, RCA 6AS7) actually cancels outits abilities a little too much for my liking. Naturally, the TF's go perfectly with the expensive trio; GEC 6AS7 (slightly warmer presentation with no loss in details, best to my ears), TS 5998 (balanced with a touch of warmth, treble can get a bit hot with HD800 my only complaint but otherwise as good as GEC) and graphite plate 6080 (extremely punchy and dynamic, but the with a bit of recess in the mids and often treble gets a bit too bright).
> ...



I agree with the 6sn7.  It's a great tube.  Great with the BHC.


----------



## cddc

cebuboy said:


> I think this is as far I can go with modding the crack..
> KZK caps for coupling and bypass
> Cree schottkey diodes
> Alps blue velvet pot
> ...




Excellent job, well organized!

Would you also post some pics showing how the 2 big 100uF caps and the cree are attached?


----------



## cddc

cebuboy said:


> So far I think I like the sound more before the cree diodes and choke. Now it sounds solid stateish...




Now, this part is kinda counterintuitive to me  ....are you sure?

I might be better off just abandoning the idea of getting a soldering station and improving my soldering skills in order to prepare for these mods that I always wanted...LOL


----------



## DenverW

cebuboy said:


> I think this is as far I can go with modding the crack..
> KZK caps for coupling and bypass
> Cree schottkey diodes
> Alps blue velvet pot
> ...



Very similar to mine! Bravo on getting those white lines to fit, I had get help with the base to make mine work. What do you think of the white lines?

oh, and you’re not done until you upgrade those power caps and bypass them!!!!

  great looking crack, man!


----------



## cebuboy

cddc said:


> Excellent job, well organized!
> 
> Would you also post some pics showing how the 2 big 100uF caps and the cree are attached?



Sure, coupling caps attached using zip ties to the mointing tabs. The cree are soldered on to a breadboard hanging below the power transformer. A friend of mine did this as I can’t do something like this without burning something.


----------



## cebuboy

cddc said:


> Now, this part is kinda counterintuitive to me  ....are you sure?
> 
> I might be better off just abandoning the idea of getting a soldering station and improving my soldering skills in order to prepare for these mods that I always wanted...LOL



I liked it after installing the KZK caps, bass went deeper and more clear with a wee bit nice reverb. After putting the choke and cree in, it makes it sound cleaner, the bit of bass reverb went away, tightening everything up, hence the solid state feeling. My chain is Macbook > Eitr > Modi MB > Crack > HD650 and Audirvana.



DenverW said:


> Very similar to mine! Bravo on getting those white lines to fit, I had get help with the base to make mine work. What do you think of the white lines?
> 
> oh, and you’re not done until you upgrade those power caps and bypass them!!!!
> 
> great looking crack, man!



I have not tried other film caps in this Crack, compared to the stock lytics, big improvement in bass depth and clarity. Well, there is still the stepped attenuator, nicer jacks too. I don't think you can fit any more caps in there..


----------



## cddc (Sep 29, 2020)

cebuboy said:


> Sure, coupling caps attached using zip ties to the mointing tabs. The cree are soldered on to a breadboard hanging below the power transformer. A friend of mine did this as I can’t do something like this without burning something.




So the cree just rests upon the crossing wires between the 2 terminal strips, and the 2 big caps are just bound to the terminal strips without any mounting?

Genius!  

Perfect for minimalists like me and @GreenNeedle


----------



## cddc

cebuboy said:


> Sure, coupling caps attached using zip ties to the mointing tabs. The cree are soldered on to a breadboard hanging below the power transformer. A friend of mine did this as I can’t do something like this without burning something.



BTW, where did you buy these metal supporting rods for the choke and what's the length? Thanks!


----------



## cddc

cebuboy said:


> I liked it after installing the KZK caps, bass went deeper and more clear with a wee bit nice reverb. After putting the choke and cree in, it makes it sound cleaner, the bit of bass reverb went away, tightening everything up, hence the solid state feeling. My chain is Macbook > Eitr > Modi MB > Crack > HD650 and Audirvana.
> 
> 
> 
> I have not tried other film caps in this Crack, compared to the stock lytics, big improvement in bass depth and clarity. Well, there is still the stepped attenuator, nicer jacks too. I don't think you can fit any more caps in there..



Sounds like another Speedball upgrade to me...improves technicalities while reducing some tubeyness...LOL 

Might need some time to get used to the new sound...


----------



## GreenNeedle

cddc said:


> BTW, where did you buy these metal supporting rods for the choke and what's the length? Thanks!


I bought some of those from Mouser when I bought the choke.  inch long ones.

How are those big caps mounted?  Zip tied to where?


----------



## cddc

Thanks, great to know Mouser also supplies accessories...thought they only supply electrical components

I think @cebuboy first used 2 large Zip ties to bind the 2 big caps together, then he attached them to the 2 terminal strips using 2 smaller Zip ties (check the photo below).


----------



## cebuboy

GreenNeedle said:


> I bought some of those from Mouser when I bought the choke.  inch long ones.
> 
> How are those big caps mounted?  Zip tied to where?



zip tied together and zip tied to the mounting tabs. 



cddc said:


> BTW, where did you buy these metal supporting rods for the choke and what's the length? Thanks!



They are from an online retailer shopee, mouser also carries them, I think those are 25mm long


----------



## carlman14

I have a special update on my franken-crack today. Covid and quarantine has me really bored, and this is what came of it: I ended up rewiring my crack to support 6J5/6C5 tubes! 2 Belton octal sockets were added just behind the volume pot and headphone jack. It looks pretty awesome if I do say so myself.

I had to remove the Audyn film cap in favor of another rectangular Panasonic film cap to make everything fit.

The 12AU7 socket is completely disconnected. I have an idea to make it so I can switch between using the 6J5 sockets or the 12AU7 socket... but that's for another day.


----------



## cddc

Wow....you are a super Cracker!

How did you make the 2 socket holes on the top plate, with some special Dremel tools?


----------



## raindownthunda

carlman14 said:


> I have a special update on my franken-crack today. Covid and quarantine has me really bored, and this is what came of it: I ended up rewiring my crack to support 6J5/6C5 tubes! 2 Belton octal sockets were added just behind the volume pot and headphone jack. It looks pretty awesome if I do say so myself.
> 
> I had to remove the Audyn film cap in favor of another rectangular Panasonic film cap to make everything fit.
> 
> The 12AU7 socket is completely disconnected. I have an idea to make it so I can switch between using the 6J5 sockets or the 12AU7 socket... but that's for another day.


Awesome work!! I love the layout decision, aesthetically it looks great. Getting closer and closer to a mini-GOTL style amp  I'm curious on what the process was to re-wiring the circuit use these sockets instead of the 12au7? Is it fairly straightforward? Was the most difficult part cutting the new holes? The switch would be KILLER!!


----------



## carlman14

cddc said:


> How did you make the 2 socket holes on the top plate, with some special Dremel tools?



I used a hole saw. I bought one from McMaster-carr that attaches to a drill. They're only about $15.



raindownthunda said:


> Awesome work!! I love the layout decision, aesthetically it looks great. Getting closer and closer to a mini-GOTL style amp  I'm curious on what the process was to re-wiring the circuit use these sockets instead of the 12au7? Is it fairly straightforward? Was the most difficult part cutting the new holes? The switch would be KILLER!!



Thanks! The process was pretty simple. Every wire from the 12AU7 is a direct rewire to a pin on one of the 6J5 sockets. You can look at the pin outs on both tubes to see which wire goes where. There's also a handy guide someone posted on the bottlehead forum (post #18): https://forum.bottlehead.com/index.php?topic=11409.15


----------



## carlman14

Favorite combo so far is the RCA metal 6J5's with ZMF headphones. Sounds wonderful.


----------



## jivex5k

carlman14 said:


> I have a special update on my franken-crack today. Covid and quarantine has me really bored, and this is what came of it: I ended up rewiring my crack to support 6J5/6C5 tubes! 2 Belton octal sockets were added just behind the volume pot and headphone jack. It looks pretty awesome if I do say so myself.
> 
> I had to remove the Audyn film cap in favor of another rectangular Panasonic film cap to make everything fit.
> 
> The 12AU7 socket is completely disconnected. I have an idea to make it so I can switch between using the 6J5 sockets or the 12AU7 socket... but that's for another day.


That's impressive! Is the circuit board with the USB-C some sort of audio interface for a pc?


----------



## carlman14

jivex5k said:


> That's impressive! Is the circuit board with the USB-C some sort of audio interface for a pc?



That is a Khadas tone board! It's an internal dac, making my crack an all-in-one unit. There's also a switch on the back of it to switch between using an external dac with the RCA cables, or using the internal dac using the USB-C. You can check out my post (# 10,048 in this thread) where I show off some better pics of the installation of the board.


----------



## DenverW (Oct 4, 2020)

@carlman14 You really should get something better than those entry level headphones in your pic 

Honestly, I logged on to post a pic of the stain job that I didnt horribly botch, and find myself humbled by what an amazing job you did.  Everything from the tone board to the new sockets just looks fantastic.  I tip my hat to you, sir.

Here is the new stain I put on the custom wood base that allows the KZK caps to fit:


----------



## carlman14

DenverW said:


> Honestly, I logged on to post a pic of the stain job that I didnt horribly botch, and find myself humbled by what an amazing job you did. Everything from the tone board to the new sockets just looks fantastic. I tip my had to you, sir.



Thanks! I appreciate the kind words. The base on yours is looking really nice. I'm also jealous of that GEC 6AS7G you've got there...


----------



## cddc

DenverW said:


> @carlman14 You really should get something better than those entry level headphones in your pic
> 
> Honestly, I logged on to post a pic of the stain job that I didnt horribly botch, and find myself humbled by what an amazing job you did.  Everything from the tone board to the new sockets just looks fantastic.  I tip my hat to you, sir.
> 
> Here is the new stain I put on the custom wood base that allows the KZK caps to fit:




Well done on the stain job!

Anyone knows how to stain the wood and make it look like chestnut (as in the pic below)?

I saw the beautiful samples in Home Depot, not sure if they use stain or paint to achieve the dark chestnut finish...


----------



## attmci

DenverW said:


> @carlman14 You really should get something better than those entry level headphones in your pic
> 
> Honestly, I logged on to post a pic of the stain job that I didnt horribly botch, and find myself humbled by what an amazing job you did.  Everything from the tone board to the new sockets just looks fantastic.  I tip my hat to you, sir.
> 
> Here is the new stain I put on the custom wood base that allows the KZK caps to fit:


What are those "cheap" headphones?? Looks better than mine.


----------



## Little Bear

cddc said:


> Well done on the stain job!
> 
> Anyone knows how to stain the wood and make it look like chestnut (as in the pic below)?
> 
> I saw the beautiful samples in Home Depot, not sure if they use stain or paint to achieve the dark chestnut finish...



You might be able to match the color, but the alder wood just doesn't have anywhere near the grain of that example in the picture.  How a finished board looks depends as much or more on the type of wood as the stain you put on it.


----------



## HiFiHawaii808

I finally signed up for Tidal and I love it.   What is the best way to stream Tidal to my BHC?    I am currently using my iPad going USB into my Schitt Modi Multibit.    Are there any products that can improve the sound over USB-C from my iPad?


----------



## chrisdrop

HiFiHawaii808 said:


> I finally signed up for Tidal and I love it.   What is the best way to stream Tidal to my BHC?    I am currently using my iPad going USB into my Schitt Modi Multibit.    Are there any products that can improve the sound over USB-C from my iPad?


Probably just enjoy where you are. That is good enough.
You could go for a dedicated streamer, even one without USB (i.e.; SPDIF>DAC>BHC). You will spend > the BHC cost most likely, however!


----------



## HiFiHawaii808

chrisdrop said:


> Probably just enjoy where you are. That is good enough.
> You could go for a dedicated streamer, even one without USB (i.e.; SPDIF>DAC>BHC). You will spend > the BHC cost most likely, however!


Thanks.  Do you think it is worth chasing MQA?   I am getting mixed signals in what I am reading about it.

I listened to some MQA recordings on my iPhone with my DragonFly Red and it sounded great.   I haven't done the A/B comparison, but from what I heard it seemed to make a noticeable difference in sound quality.   Could be the placebo effect though, I'll admit.


----------



## JamieMcC (Oct 12, 2020)

HiFiHawaii808 said:


> I finally signed up for Tidal and I love it.   What is the best way to stream Tidal to my BHC?    I am currently using my iPad going USB into my Schitt Modi Multibit.    Are there any products that can improve the sound over USB-C from my iPad?



Probably not a replacement in DAC capability to the Modi but the $99 new hiby R2 looks a interesting product with Tidal, MQA, WiFi & Bluetooth. Looks like potentially two ways to connect to a amp analogue out via trs to RCA adaptor from the R2 direct to Crack or usb digital out to Modi onto Crack.  Hiby have a app so looks like you can use iPad or mobile to control remotely via WiFi that might make for a simple wire free streaming option with the ability to control volume as well if your amp was not within reach.

  I'm guessing a bit here that when used as a portable device it uses your mobile phone signal to connect with tidal if out and about when your travelling.


https://darko.audio/2020/10/hibys-r2-puts-tidal-mqa-into-the-smallest-of-pockets-for-99/


----------



## chrisdrop

HiFiHawaii808 said:


> Thanks.  Do you think it is worth chasing MQA?   I am getting mixed signals in what I am reading about it.
> I listened to some MQA recordings on my iPhone with my DragonFly Red and it sounded great.   I haven't done the A/B comparison, but from what I heard it seemed to make a noticeable difference in sound quality.   Could be the placebo effect though, I'll admit.


MQA - no. IMO it is a digital copyright (and other things) scheme, not really a quality scheme. You might find this interesting.
I am on Roon w/ flac for my favourites, Tidal for breadth. A good streamer does make a difference, but you need a pretty beefy system before it makes a material difference. 
Here is an old post on my streamer journey. 
Headphones matter most - spend there if you are not already on ZMF !


----------



## chrisdrop

And here is today at the office: Fivre 6J5GT via @Deyan adapter. I really like these in the Crack.


----------



## bagwell359 (Oct 13, 2020)

I use Tidal/UAPP for MQA.  If some of the music I'm listening isn't MQA then: I get dig parametric EQ, balance (amp doesn't have one, but my ears not even), crossfeed.  It also seems in some cases w/ MQA I can still add the other features and lose bit-perfect, but still have some of the MQA increases in fidelity.

MQA is easy to hear on HEX v2, HE6se, HE-500, HD-600 - on Rag 1/Gumby 1.  And for the HD-600 on BHC - this combo is of course seductive, liquid, etc. and anything that gets more definition into that mix w/o any spikiness (like say a DAC "upgrade" using SABRE chips) allows for even more enjoyment of the the 600/BHC combo.

BTW, my cost of MQA is: $200 for a used mint LG v40, $20 cable, $20/month for TIDAL MQA - and its level of fidelity is the same or better than my last analog rig (very high end).

BTW, I do not agree with many fans of the v40, the sound direct into my HEX v2 or HD-600 (set to high output) is too bright, and continually changes emphasis on treble details which is annoying).


----------



## HiFiHawaii808

My new box of tubes just arrived today.  I've been listening all afternoon and the sound is glorious.    I am listening with TS 5998 and CBS Hytron 5814a.   The bass is amazing now with HD600s.   Deep, clean and clear.   Getting a nice halo effect with classical music.    This is just so good.   I am going to have to try this set up with some HD800S or 820s.    I am guessing it will pair fine.


----------



## HiFiHawaii808

JamieMcC said:


> Probably not a replacement in DAC capability to the Modi but the $99 new hiby R2 looks a interesting product with Tidal, MQA, WiFi & Bluetooth. Looks like potentially two ways to connect to a amp analogue out via trs to RCA adaptor from the R2 direct to Crack or usb digital out to Modi onto Crack.  Hiby have a app so looks like you can use iPad or mobile to control remotely via WiFi that might make for a simple wire free streaming option with the ability to control volume as well if your amp was not within reach.
> 
> I'm guessing a bit here that when used as a portable device it uses your mobile phone signal to connect with tidal if out and about when your travelling.
> 
> ...



that does look interesting.   I like that it supports 5G wifi.   It's cheap so maybe worth a try.    I could also try something similar with my Dragonfly Red since it does support MQA, but I think I may be chasing a unicorn that doesn't exist.   I may be better off just upgrading my DAC from a Modi to a Bimby.


----------



## HiFiHawaii808

What's really weird is that the tubes cost more than my headphones and the tubes are 50 years old.


----------



## PsilocybinCube

HiFiHawaii808 said:


> What's really weird is that the tubes cost more than my headphones and the tubes are 50 years old.


Bro, get that HD800.  It pairs nicely with the BHC.  I came from the HD650 and the HD800 is a monumental step up.


----------



## GreenNeedle

cddc said:


> Well done on the stain job!
> 
> Anyone knows how to stain the wood and make it look like chestnut (as in the pic below)?
> 
> I saw the beautiful samples in Home Depot, not sure if they use stain or paint to achieve the dark chestnut finish...



You could try a similar method to how they make the grain stand out on guitar veneers.  Stain the top, let it dry, sand back until only the grain is dark, stain again over the top.

With guitars you would tend to use dye instead of stain.  black dye, sand back, do it again if required, then put the colour dye on top, let it dry then clear lacquer over the top, let it set for at least a couple of weeks then fine sand/rub for that piano gloss finish.

Or just buy dark walnut (real wood) veneer and glue it on.  Veneer is cheaper in the US than Europe, especially walnut.


----------



## cddc

I am a newbie to wood work. Thanks a lot for explaining the different approaches to color the wood.

I think I like the stain or veneer approach better than the dye/paint approach. The finish on guitar or piano basically covers up the beautiful grains on the wood.

But I think stain is very difficult to work with, as @DenverW has pointed out in his work.

To make something as beautiful as the samples below would be quite challenging, I guess...


----------



## GreenNeedle (Oct 19, 2020)

cddc said:


> I am a newbie to wood work. Thanks a lot for explaining the different approaches to color the wood.
> 
> I think I like the stain or veneer approach better than the dye/paint approach. The finish on guitar or piano basically covers up the beautiful grains on the wood.
> 
> ...


You can buy "tinted" oil finishes.  Wipe on, wipe off etc.  If you look above oil would turn the left picture into the right picture.  The Alder when you get it is light, When you oil it naturally tints it anyway but you can buy Oils with added tints in them.  I however use a natural "untinted" one  (Untinted still tints a little.)

The easiest way to get the colour you want is for the surface to already be close.  like dying hair.  It is much harder to go from one extreme to another.

A few examples:
This is rosewood veneer before and after.  The photos are quite accurate and it is the same veneer I have used on my Crack but I didn't take "befores" with the Crack.  Before it is a beautiful grain but a dull finish and visually quite a flat 2D appearance.  After it comes alive.  3D and really popping,  It also is holographic with light. The colours in these photos are quite accurate (on my screen) so you can really see the difference.  A lighter yellowy brown before.  A much darker redder after:


Something Darker?  Macassar Ebony.  Similar to the rosewood before.  A dusty undefined finish but it looks like dark chocolate and caramel after oiling:


Something lighter?  Zebrano is very light, almost white but the dark grains contrasting look really good.  This wood really does pop after oiling:


Flame Maple on an old highgate alpha of no value?  Why not.  Incidentally this maple is exactly the same colour as the BH Alder before Oiling:


Try it.  The big roll in the first pic cost about £30.  It would probably be only $20 in the US.  You could veneer 10 Cracks with that so plenty of it to practice on other things ↑

And p.s.  I can't get good finishes with stains.  I am useless at it.  Dyes with lacquer on top I can get away with.  Can't go wrong with Oiling.  If it isn't working you just let it cure for a week or 2 and sand it back before continuing.

And I am not a carpenter nor a pro.  The above are all still in my house apart from the Alpha which my Dad has permanently on listening to the radio in his retirement.  I can't afford "nice" things so I make them "nice" instead


----------



## GreenNeedle

CDDC.  I just noticed your avatar.  That guitar would have been the same colour as the alder before:



But add dyes, coat with lacquer and:



This was probably the one project I wish I hadn't done. lol.  I wish I had just sanded up the swamp Ash, then oiled it and left it as the Ibanez Blazer it was.


----------



## HiFiHawaii808 (Oct 19, 2020)

Got a couple more tubes.   Finally got a Western Electric 421a.   It looks pretty much identical to the Tung Sol 5998 (bottom getter).   It sounds bigger and grander than the Tung Sol.  It really makes the HD600 sound warm with deep and tight bass.  It took a while to sound right.  It actually sounded quite bad at first.   Several hours of play time to self correct.    And, it takes a while to warm up where only one channel is audible for a few minutes.  Not sure if that is indicative of any problems.

Also got an Amperex Bugle Boy 12au7.    It has that old buzzy sound and the sound stage really collapses to little peep hole.

I'll do an A/B comparison with the TS 5998 and Western Electric 421A later when I get a chance.   I think I read where someone posted that the tubes are identical.   I don't think so.   Right now, I am just enjoying the listening experience.


----------



## PsilocybinCube

HiFiHawaii808 said:


> Got a couple more tubes.   Finally got a Western Electric 421a.   It looks pretty much identical to the Tung Sol 5998 (bottom getter).   It sounds bigger and grander than the Tung Sol.  It really makes the HD600 sound warm with deep and tight bass.  It took a while to sound right.  It actually sounded quite bad at first.   Several hours of play time to self correct.    And, it takes a while to warm up where only one channel is audible for a few minutes.  Not sure if that is indicative of any problems.
> 
> Also got an Amperex Bugle Boy 12au7.    It has that old buzzy sound and the sound stage really collapses to little peep hole.
> 
> I'll do an A/B comparison with the TS 5998 and Western Electric 421A later when I get a chance.   I think I read where someone posted that the tubes are identical.   I don't think so.   Right now, I am just enjoying the listening experience.


Congrats on some great tubes.  I'd recommend cross-posting in the 6as7g thread for some thoughts on the channel imbalance during warm-up.  Those folks have been very helpful for me.  
https://www.head-fi.org/threads/for-6as7g-tube-rollers-here.410326/page-398#


----------



## cddc

GreenNeedle said:


> You can buy "tinted" oil finishes.  Wipe on, wipe off etc.  If you look above oil would turn the left picture into the right picture.  The Alder when you get it is light, When you oil it naturally tints it anyway but you can buy Oils with added tints in them.  I however use a natural "untinted" one  (Untinted still tints a little.)
> 
> The easiest way to get the colour you want is for the surface to already be close.  like dying hair.  It is much harder to go from one extreme to another.
> 
> ...



Wow…can’t believe oiling can do such magic to veneers. The dull grain on the veneers just popped out after oiling.

Years ago I saw people applied Danish Oil to their Crack, the results were pretty good, but just not as impressive as the works you did.

Thanks a lot for sharing your excellent wood works and their recipes.

BTW the vintage radio looks awesome!


----------



## cddc

GreenNeedle said:


> CDDC.  I just noticed your avatar.  That guitar would have been the same colour as the alder before:
> 
> 
> 
> ...




Why you wish you hadn't done the project...the finish on your bass looks fabulous...very close to Les Paul, the most beautiful guitar ever made.

Excellent workmanship!


----------



## cddc

HiFiHawaii808 said:


> Got a couple more tubes.   Finally got a Western Electric 421a.   It looks pretty much identical to the Tung Sol 5998 (bottom getter).   It sounds bigger and grander than the Tung Sol.  It really makes the HD600 sound warm with deep and tight bass.  It took a while to sound right.  It actually sounded quite bad at first.   Several hours of play time to self correct.    And, it takes a while to warm up where only one channel is audible for a few minutes.  Not sure if that is indicative of any problems.
> 
> Also got an Amperex Bugle Boy 12au7.    It has that old buzzy sound and the sound stage really collapses to little peep hole.
> 
> I'll do an A/B comparison with the TS 5998 and Western Electric 421A later when I get a chance.   I think I read where someone posted that the tubes are identical.   I don't think so.   Right now, I am just enjoying the listening experience.




I normally wait only one or two minutes for my Crack to warm up and then start to listen to music, by which time both channels play nicely, though the optimal status may come half an hour later. One channel does not make any sound after a few minutes warm-up while the other does is a bad sign. It could be a sign that the cathode on that channel is near depletion and can not emit enough electrons (so need more time to heat up in order to emit enough electrons).

Had the 421A been tested by the seller before you bought it? If it was tested, the test values should be able to tell you something about the status of both channels.


----------



## cddc

HiFiHawaii808 said:


> Got a couple more tubes.   Finally got a Western Electric 421a.   It looks pretty much identical to the Tung Sol 5998 (bottom getter).   It sounds bigger and grander than the Tung Sol.  It really makes the HD600 sound warm with deep and tight bass.  It took a while to sound right.  It actually sounded quite bad at first.   Several hours of play time to self correct.    And, it takes a while to warm up where only one channel is audible for a few minutes.  Not sure if that is indicative of any problems.
> 
> Also got an Amperex Bugle Boy 12au7.    It has that old buzzy sound and the sound stage really collapses to little peep hole.
> 
> I'll do an A/B comparison with the TS 5998 and Western Electric 421A later when I get a chance.   I think I read where someone posted that the tubes are identical.   I don't think so.   Right now, I am just enjoying the listening experience.




Whether TS 5998 and WE 421A are the same was a huge debate. 

Normally if 2 tubes possess the same innards in any other types of tubes, they would always be considered the same tube - one being the original and the other being the rebrand of course. But some people just can't treat TS 5998 / WE421A the same way, which is pretty weird!

The biggest "fact" that those "not-the-same-tube" believers often cite is that on tube specs datasheets WE421A has transconductance of 20,000 uMhos vs TS5998 only 14,000 uMhos. So they think the 2 are different tubes because they have different transconductances. But what they do not know is that these different transconductances were obtained under different plate voltages and grid voltages, if WE421A and TS5998 were tested under the same plate voltage and grid voltage, they will have the same measured transconductance. And I don't blame those believers, as most of them has little knowledge on how testers work and how transconductances are measured if at all.

Some people say the 2 sound the same, while others say WE421A sounds better. Well, this is quite subjective, and people's opinions are often biased by the prices. It's quite psychological, but it is true. People tend to think the expensive tubes sound better even if they were hearing the same tube oftentimes. This psychological effect can be eliminated by a double-blind test, but in practice few people were able to do a double-blind test.

I used to be 90% sure that WE421A and TS5998 are the same tube (because I only heard subjective reviews with few concrete data). Until recently after spending weeks researching how testers work and their datasheets I'veI become 100% sure that WE421A and TS5998 tube are the same tube. 

Data/Facts:
On the military TV-7 tester datasheet, there is one entry for TS5998 and one entry for WE421A. I compared the 2 entries, they are the SAME! So they are using the exactly the same settings and exactly the same plate voltage and grid voltage to test the 2 tubes on TV-7, and the minimum good value of 40 is also the same for both tubes (side note: minimum good value is normally 1 Standard Deviation away from the 100% new, so it is often set at 65% of 100% new on various testers). This proves that the biggest "fact" those "not-the-same-tube" believers hold is WRONG. If TS5998 and WE421A are tested under the same plate voltage and grid voltage, they will have exactly the same transconductance as per the military TV-7 datasheet. Had the WE421A come with a much higher transconductance than TS5998, its minimum good value would have been much higher than 40, but WE421A and TS5998 just have the same minimum good value of 40 if they are tested under the same plate voltage and grid voltage on TV-7. On their datasheets WE421A has a higher transconductance of 20k Mhos (vs 14k Mhos on TS5998), that's only because WE421A was tested with higher plate and grid voltages (i.e. more positive voltage on the plate and less negative voltage on the grid so that the current flow between cathode and plate will become much larger and measured transconductance will be much higher). But if we apply the same plate voltage and grid voltage on these 2 tubes, they will have the same measured transconductance as proved by the military TV-7 datasheets. (side note on the U.S. military TV-7 tube tester: it is for use in battle fields, so accuracy and reliability is of top priority. The datasheets for TV-7 has to be certified by tube and tube tester experts. So I trust what the TV-7 datasheets tell me). Other testers say the same thing, like the 752A tester also has the same test settings and minimum good value for the 2 tubes.

While I do trust our tube and tube amp expert @Skylab 's opinion that WE421 and TS5998 are the same tube and sound the same to him (side note: Rob aka @Skylab did lots of great professional grade reviews on tube amps and tubes, and has a gigantic collection of NOS tubes - see pic below), I am more of a scientific person, I always try to be as objective/unbiased as possible, so I'd rather trust data/facts than people's subjective and often money-biased opinions, but what I found through data/facts also prove WE421A and TS5998 are the same tube. Both tubes had some small variations over the years, but they are essentially the SAME tube, both designed by Western Electric and manufactured by Tung Sol / Chatham. 








PS:   @Skylab , if you mind me posting the pic that you posted long time ago, let me know, I will delete it.


----------



## tintinsnowydog (Oct 20, 2020)

Just received these interesting smooth welded plate, slanted square getter CV491. HR indicates it’s a Mullard from the Hivac Ruislip factory, dated December of 1953. They test very low so got them much cheaper than the crazy prices welded plate Mullards are going for right now. They sound incredible paired with an Osram A1834, the most beautiful yet accurate midrange tonality I have heard, especially for classical violin and orchestra. Wide soundstage, bass is well controlled and impactful, treble clear but never harsh.

I wasnt a believer in the different Mullard constructions sounding very different, but this is definitely the best 12AU7/ECC82 I’ve heard, a step above the later k61/gf1/gf2/cv4003 Blackburns in most aspects of sound. Am yet to try the amperex 7316 or MOV offerings, but I wont spend more than double digits for any 12AU7- may be a while before I can hear them


----------



## HiFiHawaii808 (Oct 20, 2020)

cddc said:


> Whether TS 5998 and WE 421A are the same was a huge debate.
> 
> Normally if 2 tubes possess the same innards in any other types of tubes, they would always be considered the same tube - one being the original and the other being the rebrand of course. But some people just can't treat TS 5998 / WE421A the same way, which is pretty weird!
> 
> ...


They both sound great.   I could not do an A/B test because of the time required to change tubes.   I did try to inspect them to see if there was any difference in the tubes and I couldn't find anything different except the label.

The tubes do behave differently as the WE 421a has a warm up period whereas the TS5998 didn't.    I'd like to do a real A/B test, but based on the data you are providing, my guess is that the major difference will just be tube variations.


----------



## DenverW

tintinsnowydog said:


> Just received these interesting welded plate slanted square getter CV491. HR indicates it’s a Mullard from the Hivac Ruislip factory, dated December of 1953. They test very low so got them much cheaper than the crazy prices welded plate Mullards are going for right now. They sound incredible paired with an Osram A1834, the most beautiful yet accurate midrange tonality I have heard, especially for classical violin and orchestra. Wide soundstage, bass is well controlled and impactful, treble clear but never harsh.
> 
> I wasnt a believer in the different Mullard constructions sounding very different, but this is definitely the best 12AU7/ECC82 I’ve heard, a step above the later k61/gf1/gf2/cv4003 Blackburns in most aspects of sound. Am yet to try the amperex 7136 or MOV offerings, but I wont spend more than double digits for any 12AU7- may be a while before I can hear them



Join me on my quest for 12au7 superiority!  My favorite is a welded plate slant getter amperex from 1945.  Now, if only we could convince the group...


----------



## tintinsnowydog (Oct 20, 2020)

HiFiHawaii808 said:


> They both sound great.   I could not do an A/B test because of the time required to change tubes.   I did try to inspect them to see if there was any difference in the tubes and I couldn't find anything different except the label.
> 
> The tubes do behave differently as the WE 421a has a warm up period whereas the TS5998 didn't.    I'd like to do a real A/B test, but based on the data you are providing, my guess is that the major difference will just be tube variations.


I am also in the camp for WE421A=5998. I have only heard them side by side briefly as I dont own the 421A but in all my tubes same internals=same sound, excluding individual tube difference. If the 421A were simply tubes that were cherry picked for testing better, that would be more than enough to explain any perceived difference.




DenverW said:


> Join me on my quest for 12au7 superiority!  My favorite is a welded plate slant getter amperex from 1945.  Now, if only we could convince the group...


1945! I thought the 12AU7 only came after 1946 starting in US and only later EU. I’d imagine they sound similar to the Hivac. As for 12AU7 superiority.. the best ones certainly do many things well especially in the mids, but for me, I still think their overall presentation is a little dry, and somewhat rolled off and prone to distortion distally at both ends. I do think the 6SN7s are much more expansive and warm/darker sounding, be that due to more euphonic distortion or otherwise. Specific 12AU7s all do certain things well, if I wanted to really nail a specific technicality I would choose from them; e.g. TFECC82 has the best clarity and laser sharp focused details, Mullards have beautiful liquidity; but they both have their flaws too. If i wanted to stick something in that just blends and sounds overall pleasant but may not have any clear strengths, I would turn to my 6SN7s.


----------



## PsilocybinCube

DenverW said:


> Join me on my quest for 12au7 superiority!  My favorite is a welded plate slant getter amperex from 1945.  Now, if only we could convince the group...


You should go on the 6sn7 thread and start a serious audiophile discussion on this...I for one have been coaxed to the 6sn7dark side despite being your jedi apprentice.


----------



## JamieMcC (Oct 20, 2020)

Pretty sure I've owned at least six variations of the 5998 tubes with differing internals they all have sounded similar sonically.

The exception being  the early Tungsol 5998 clear top variant (1950's) which to me most definitely had a different sonic character. I also have several WE421a and would consider the early Tungsol clear top my favourite tube of all the variants of 5998 I've had so far it just had something a bit special about how it sounds compared to the others I've owned.


----------



## cddc

tintinsnowydog said:


> I am also in the camp for WE421A=5998. I have only heard them side by side briefly as I dont own the 421A but in all my tubes same internals=same sound, excluding individual tube difference. If the 421A were simply tubes that were cherry picked for testing better, that would be more than enough to explain any perceived difference.



I used to think WE 421A is a cherry-picked TS 5998 too, but it's just some hearsay, no concrete proof. But the more I think about it, the more I feel like it's unlikely to be some  cherry-picking. No company will pick out its best products for other companies to sell and leave only those low quality products for itself to sell, coz that will only promote its rivals and ruin its own reputation. Tung Sol has a good reputation in the industry, so I don't think it would cherry-pick its 5998 tubes.

I think the most likely scenario is like this: 
Western Electric received some request from its parent company AT&T to design and manufacture some special tubes for their telecom facilities, so Western Electric did the R&D job and came up with the 5998 prototype. But somehow WE felt it's not economically favorable to set up a new product line to fulfill the orders from AT&T - maybe the order size from AT&T was not large enough for them to break even, maybe WE did not have enough resources at that time.....So Tung Sol saw the opportunity and proposed to Western Electric, "Hey Bro, I've got plenty of extra capacities, I can help you manufacture these tubes. But you know your order size is too small for me to break even. So how about you license me to make and sell these tubes under my label so that I can break even? And of course I will give you a very good price for your orders (cost + 5% profit margin)." "Deal!" said the WE managers after seeing the price TS offered. So TS set up new product lines and started to manufacture these 5998 tubes, the ones for WE would be labelled as WE 421A, and the ones for themselves to sell would be labelled as TS 5998 / TS 421A / Chatham 5998 / TS 2399 / TS 6520 / etc. Of course, WE had some special specifications to meet, in order for these tubes to be used in AT&T equipment. So TS tested its WE 421A tubes using the WE specs, those not meeting the WE specs would be discarded. Some people may think of this process as cherry-picking. But it doesn't mean TS did not QA its own 5998 tubes, I think TS would also ditch these TS 5998 tubes that failed to meet its own QA specs.

And below is a solid proof that Tung Sol manufactured 5998 under contract to Western Electric. It's an article by Eric on the 17th issue of the Vacuum Tube Valley magazine (the article was found by @attmci).


----------



## Little Bear (Oct 21, 2020)

I don't have any experience (yet) with either tube, but I'm inclined to believe that any sonic differences between them most likely comes down to individual tube variations in measurements due to age and hours of use.  I suspect that when new, they sounded identical, and most of them with similar hours probably still do.  But one specific tube might sound better than another one (even of the same variety), which may explain the ongoing debate.

I recently bought an unused TS 5998 for $195 to use in my Crackatwoa.  I think an unused WE421a goes  for, what, $500?  Even $195 for a 5998 isn't easy to justify, IMO.


----------



## HiFiHawaii808

Little Bear said:


> I don't have any experience (yet) with either tube, but I'm inclined to believe that any sonic differences between them most likely comes down to individual tube variations in measurements due to age and hours of use.  I suspect that when new, they sounded identical, and most of them with similar hours probably still do.  But one specific tube might sound better than another one (even of the same variety), which may explain the ongoing debate.
> 
> I recently bought an unused TS 5998 for $195 to use in my Crackatwoa.  I think an unused WE421a goes  for, what, $500?  Even $195 for a 5998 isn't easy to justify, IMO.


the market certainly thinks there is some differential value for a WE421a vs TS5998.   I haven't yet done an A/B comparison, but I am switching the tubes.   It feels like the 421a has a bigger sound stage and has a more dynamic sound.   Not sure if that is confirmation bias or tube variation.   But the 421a seems to have a slight advantage.   I won't know for sure until I do an A/B comparison test.  Could be a while because I only feel comfortable doing it if I have 2 BHCs with similar build.


----------



## tintinsnowydog (Oct 24, 2020)

HiFiHawaii808 said:


> the market certainly thinks there is some differential value for a WE421a vs TS5998.   I haven't yet done an A/B comparison, but I am switching the tubes.   It feels like the 421a has a bigger sound stage and has a more dynamic sound.   Not sure if that is confirmation bias or tube variation.   But the 421a seems to have a slight advantage.   I won't know for sure until I do an A/B comparison test.  Could be a while because I only feel comfortable doing it if I have 2 BHCs with similar build.


Would be great to hear your findings! If you’re able to measure the plate voltages that would be even better to see if they are doing anything different electrically.

Have been enjoying dual GEC CV4079 as power tubes the last few days. They’re a great budget alternative to the GEC 6AS7G, with all its technicalities and only a little less warmth and soundstage. RCA 6SN7  in the driver slot gives great bass while warming up the mids and highs, without being too aggressive like the Ken Rad 6SN7 in the low end. Currently enjoying Sylvania VT-231 with HD800, incredibly smooth highs (one could argue it’s rolled off... but definitely enough detail still), singing midrange, and high quality, non-exaggerated bass. They are definitely not bass light paired with the right power tubes- at least not for classical symphonies


----------



## bagwell359

Little Bear said:


> I don't have any experience (yet) with either tube, but I'm inclined to believe that any sonic differences between them most likely comes down to individual tube variations in measurements due to age and hours of use.  I suspect that when new, they sounded identical, and most of them with similar hours probably still do.  But one specific tube might sound better than another one (even of the same variety), which may explain the ongoing debate.
> 
> I recently bought an unused TS 5998 for $195 to use in my Crackatwoa.  I think an unused WE421a goes  for, what, $500?  Even $195 for a 5998 isn't easy to justify, IMO.



When I was looking this summer for a power tube, I'd have taken yours for that money.  It's not a steal, but if its what it purports to be, it's a good deal.


----------



## HiFiHawaii808 (Oct 25, 2020)

I did some moderate testing between my bottom getter TS 5998 and WE 521A.   A few hours of testing across many different music genres.    It's pretty conclusive to me that for these tubes, the 421A sounds better.   It has a slightly larger sound stage and a much sweeter timber to violins.   I can hear it at all volume levels.   It's like the 5998 has a slight veil in comparison for the highs.   The 421a sounds grander and more open.

I am sure it is not confirmation bias because I can hear the difference in most tracks.   I don't know if the difference in sound is just tube variation.  I'd have to get a few more of each to test them.

After hearing these tubes and reading the reports that they appear to be the same tubes, I can only conclude that the most likely way to account for the differences is that the better tubes were pulled from various lots and branded as 421a vs TS5998.   I know that sounds unlikely, but I don't know how to account for the sound difference.   I would do a double blind test, but it's just too hard with these tubes on this amp given their warm up and cool down requirements and potential for operator error.


----------



## DenverW

I have had both the 5998 and the different types of 421A.  YMMV but I found a clear difference in the 421A tubes, of either type.  Better separation and clarity.

But hey, lets talk bottlehead power cord.  I have two stock, and I'm considering making a third with different wire, perhaps the duelund 20awg tin plate copper hook up wire (600vdc).  Wonder if the different wire would make a different.  The other thing I'm considering is filling one of the cables with fine steel shot like the old audio dynamic power 3 cables.


----------



## HiFiHawaii808

DenverW said:


> I have had both the 5998 and the different types of 421A.  YMMV but I found a clear difference in the 421A tubes, of either type.  Better separation and clarity.
> 
> But hey, lets talk bottlehead power cord.  I have two stock, and I'm considering making a third with different wire, perhaps the duelund 20awg tin plate copper hook up wire (600vdc).  Wonder if the different wire would make a different.  The other thing I'm considering is filling one of the cables with fine steel shot like the old audio dynamic power 3 cables.


I purchased an upgraded power cord.   It definitely impacts the sound.  It really deepened the bass and closed in the sound stage.  Felt like I was sitting right next to the bass player.   Live feel to the music with a more intimate feel.   It was really good for small 4 piece bands in intimate settings.   Jazz combos and rock and roll, but no strumming guitars like with the Eagles.   The elevated bass put a veil on the mids.   I used it before I did any tube rolling.    Once I got really nice tubes, I found the upgraded power cord was bringing the sound out of balance.   Too much bass and closing in the sound stage rather than letting it open up.  So, now I have stopped using it completely.   I would use it with the stock tubes or maybe the stock BHC with speedball.


----------



## DenverW

I found the bottlehead power cord to be one of the bigger jumps in sound quality overall, thats why I have one for both my amps.  I'm just getting the itch to DIY a different type, or to modify one of the two that I have.


----------



## PsilocybinCube

DenverW said:


> I found the bottlehead power cord to be one of the bigger jumps in sound quality overall, thats why I have one for both my amps.  I'm just getting the itch to DIY a different type, or to modify one of the two that I have.


I found I was still getting some interference from my PC after making this.  I purchased some shielded tech flex and it helped greatly.  Also, the tech flex that ships with the BHC is oversized relative to what is actually needed so it's nice to have the cord be a bit more tidy.
https://www.wirecare.com/category/braided-sleeving/metal-shielding-sleeving/flexo-shield


----------



## DenverW

PsilocybinCube said:


> I found I was still getting some interference from my PC after making this.  I purchased some shielded tech flex and it helped greatly.  Also, the tech flex that ships with the BHC is oversized relative to what is actually needed so it's nice to have the cord be a bit more tidy.
> https://www.wirecare.com/category/braided-sleeving/metal-shielding-sleeving/flexo-shield



What size did you order?


----------



## PsilocybinCube

DenverW said:


> What size did you order?


I purchased one 10 ft cut of 1/2 inch shielded techflex.  Also, you can really use a smaller diameter heat shrink and just not have it go over the male end, instead have the mail end clamp onto the heat shrink as most people do with DIY power cords.  It results in a much cleaner finish.


----------



## GreenNeedle

Does anyone know who made tubes for RTRA?

https://www.ebay.co.uk/itm/RTRA-6SN...700047?hash=item340924b54f:g:SekAAOSwMYRaftSa


----------



## tintinsnowydog (Oct 31, 2020)

GreenNeedle said:


> Does anyone know who made tubes for RTRA?
> 
> https://www.ebay.co.uk/itm/RTRA-6SN...700047?hash=item340924b54f:g:SekAAOSwMYRaftSa


Those photos are so blurry.. The plates and top mica supports look similar to Foton 6N8S but I am not sure. 'Foreign made' so it is possibly a euphemism for lesser known branding. Would be beneficial to post it here too  https://www.head-fi.org/threads/the-6sn7-identification-guide.209782/page-22


----------



## cebuboy

GreenNeedle said:


> Does anyone know who made tubes for RTRA?
> 
> https://www.ebay.co.uk/itm/RTRA-6SN...700047?hash=item340924b54f:g:SekAAOSwMYRaftSa


Looks like a '60s Foton.


----------



## HiFiHawaii808 (Oct 31, 2020)

Oops. Posted on the wrong thread.    My bad.


----------



## cddc

GreenNeedle said:


> Does anyone know who made tubes for RTRA?
> 
> https://www.ebay.co.uk/itm/RTRA-6SN...700047?hash=item340924b54f:g:SekAAOSwMYRaftSa




This is a Russian Foton 6N8S made in 60s, normally $3-ish, the link is a rip-off, don’t buy it.

The other tube you posted is a Sylvania Bad Boy


----------



## cddc

Don’t know who bought the Bad Boy, when I saw the link it had gone already.


----------



## GreenNeedle

cddc said:


> Don’t know who bought the Bad Boy, when I saw the link it had gone already.


  he, he.


----------



## cddc

GreenNeedle said:


> he, he.



So you bought it?

The transconductance measurement of that tube is NOS+.


----------



## attmci

cddc said:


> This is a Russian Foton 6N8S made in 60s, normally $3-ish, the link is a rip-off, don’t buy it.
> 
> The other tube you posted is a Sylvania Bad Boy


Not sure if it is a "bad boy".


----------



## cddc

attmci said:


> Not sure if it is a "bad boy".




Why not sure? Because of the year 1959?


----------



## GreenNeedle

cddc said:


> So you bought it?
> 
> The transconductance measurement of that tube is NOS+.



I took a chance on it yes   Even if the date doesn't match, it looked right in every other way to the Bad boy in the middle of the ID thread with the silver glass from base to bottom mica.  Only listening will tell


----------



## cddc (Oct 31, 2020)

GreenNeedle said:


> I took a chance on it yes   Even if the date doesn't match, it looked right in every other way to the Bad boy in the middle of the ID thread with the silver glass from base to bottom mica.  Only listening will tell




Nice score. It is a true bad boy, the year 1959 on the base only means that tube was shipped out in 1959.

Zalytron is a UK rebrander, it might order the batch of tubes from Sylvania in 1953, it took a year or 2 for the tubes to reach the UK, then sitting in their warehouse for another couple of years until Zalytron finally silk printed its logo and 1959 on the base, and shipped them out.


----------



## cddc

BTW, since the tube is located in the UK, the seller might have used an AVO tester to measure the transconductance.

IIRC, the NOS on AVO is 2.6, not sure why the seller stated 2.9 as NOS in his ads, which might make his tubes look bad...At least he’s honest, I think.


----------



## GreenNeedle (Oct 31, 2020)

cddc said:


> Nice score. It is a true bad boy, the year 1959 on the base only means that tube was shipped out in 1959.
> 
> Zalytron is a UK rebrander, it might order the batch of tubes from Sylvania in 1953, it took a year or 2 for the tubes to reach the UK, then sitting in their warehouse for another couple of years until Zalytron finally silk printed its logo and 1959 on the base, and shipped them out.



When it arrives I'll pair it with one of the TS5998 pair I got for £40.  Nice budget tubes these   £60 cost for a 5998/(possible) badboy combo. 

I'm all setup for this new lockdown now.  Got the diodes for the groundbreaker, Have 3 Mundorf EVOs, Triad choke, cree diodes and little power board.  Oh and the Speedball.  None of this installed yet.  It is still stock except the TKD volume pot.


----------



## cddc

£80 for a 5998 is a great score. You are doing very well in finding good tubes 

The EVO’s are quite expensive, but if you want to max out your Crack, it’s the way to go


----------



## GreenNeedle

cddc said:


> £80 for a 5998 is a great score. You are doing very well in finding good tubes
> 
> The EVO’s are quite expensive, but if you want to max out your Crack, it’s the way to go


£80?  It was £40 for a pair of used ones.


----------



## cddc

Wow...you are a master in finding tubes with great prices.


----------



## GreenNeedle (Nov 3, 2020)

cddc said:


> Wow...you are a master in finding tubes with great prices.


Got lucky with the 5998s.  Obviously seller didn't know what they were and listed them up at £40 inc shipping.  I was looking for tubes and these didn't come up.  Had one more look and these appeared.  I bought them 2 minutes after he had listed them .  If I hadn't been on ebay OR if I hadn't had another look then someone else would have got lucky.

I guess I also got lucky that they both work........and boy do they work 

On a BH note, I'm just holding off doing all the upgrades because my noval socket is still crackling.  Sometimes for no reason but if I move the tube slightly it crackles.  Might be that things are a bit loose as I have soldered/unsoldered 3 times.  I've bought a (ebay but I like to trust) 60s Spanish made ceramic noval




and I might need to re-wire some other wires in the vicinity because I got a bit clumsy with the soldering iron last time and there are a few burns on wire housings etc. lol.

Plus bought a Jack Russell Puppy 3 weeks ago.  She is now 11 weeks old and does not stop biting everything.  I am a little too worried that the volume might cut out only to see puppy eyes looking up at me with delight as she chews on a broken headphone cable. lol.

I'll post up some new pics before Xmas.  I already have a pair of 6H13C coke bottles that I haven't even tried yet.  I bought them an hour before I got the 5998s and as they took longer to arrive they didn't really stand a chance of getting used early on   I also have a Thompson 6080WA.  No idea  if it is one of the "dodgy ones" people talk about but it looks pretty modern to me and new in a perfect condition box so seems unlikely it is an NOS old one.

Then I have a Brimar 6SN7GT on its way.  All of those I haven't tried yet.  I have far too many tubes really for my uses.  I want to find a couple of different combos I like and then sell on the rest.

So far my go to is the 5998 with either the Mazda 12AU7 or "Tung Sol*" 6SN7GT  *Branded Tung Sol but I think this is the "Raytheon" rebranded as Tung Sol mentioned in post #113 in the 6SN7 thread:
https://www.head-fi.org/threads/the-6sn7-identification-guide.209782/page-8#post-13476833
I think I paid £24 inc shipping for the Raytheon-Tung Sol.  Re-brand or not it sounds great and just edges out the Mazda but not by much.  I seem to be the only giving love to the Mazda though.  It is that good and cheap that I bought another 6 within an hour of hearing it.

Laptop-Music Bee (Wasapi)-USB into Topping D30 into BH Crack with the 5998 and Ray-Sol 6SN7GT into AKG Sextetts (MP).    Rush - Permanent Waves on.  (Puppy is asleep.)  Absolute Heaven  And this is still stock (no crackling at the mo either.)


----------



## JTori

*Do These Caps Make My Amp Look Big?*

I've been enjoying listening to my Crack-a-two-a in its stock form for the past few months, save for the installation of some very nice tubes.  I purchased a pair of Clarity caps around the time I finished building the amp and just got around to fitting them.  It was necessary to reposition a couple of terminal strips and resistors, lengthen/shorten a couple of wires and fabricate some mounting blocks.  Here’s the finished product.  Tested it out.  All seems good, and in the past couple days I've been doing some critical listening with the Sennheiser HD800S.  

The amp is a lot more incisive with the upgraded caps, and vocals are more palpable. Percussion is delivered punch, impact, grunt and pace.  Cymbals sound as real as I've heard, with natural timbre and sustain.  micro dynamics.  Vocals -- female and male -- are so present and there.  Overall, music sounds real to me.  I think it's safe to says I won't be doing any further upgrades to t he amp. 




 

Joe.


----------



## lessblue (Nov 12, 2020)

nm


----------



## bagwell359

JTori said:


> *Do These Caps Make My Amp Look Big?*
> 
> I've been enjoying listening to my Crack-a-two-a in its stock form for the past few months, save for the installation of some very nice tubes.  I purchased a pair of Clarity caps around the time I finished building the amp and just got around to fitting them.  It was necessary to reposition a couple of terminal strips and resistors, lengthen/shorten a couple of wires and fabricate some mounting blocks.  Here’s the finished product.  Tested it out.  All seems good, and in the past couple days I've been doing some critical listening with the Sennheiser HD800S.
> 
> ...



I use the same caps on my BH, guess what?  They are not inside the cabinet.  Sound great as you say, lots of refinement including some very nice decay.  Female vocals in the center get more air too.  No pics, its still ungainly looking.


----------



## JTori

bagwell359 said:


> I use the same caps on my BH, guess what?  They are not inside the cabinet.  Sound great as you say, lots of refinement including some very nice decay.  Female vocals in the center get more air too.  No pics, its still ungainly looking.



Not surprising.  There's not a lot of real estate inside the Crack envelope to accommodate them; they're large.  Did you build a separate enclosure for them?  Even with the extra room provided by BH on the Crack-a-two-a, I had to use my best packaging engineering skills.  I did quite a bit of measuring and revisualization before attacking the task.  I'm pleased with the outcome, though.  Well worth the effort!

Best,

Joe.


----------



## bagwell359

JTori said:


> Not surprising.  There's not a lot of real estate inside the Crack envelope to accommodate them; they're large.  Did you build a separate enclosure for them?  Even with the extra room provided by BH on the Crack-a-two-a, I had to use my best packaging engineering skills.  I did quite a bit of measuring and revisualization before attacking the task.  I'm pleased with the outcome, though.  Well worth the effort!
> 
> Best,
> 
> Joe.



Imagine them stacked between the chokes wrapped in copper sheeting.

Walt


----------



## bagwell359 (Nov 13, 2020)

w/ tubes.  HA!  Joe, I knew it was a JMW Memorial on a VPI.


----------



## Wesley88

Crack + Speedball + Mods. Built for me by a forum friend. Tubes are Chatham 6AS7G + Tung-Sol 12AU7.


----------



## cddc

Wesley88 said:


> Crack + Speedball + Mods. Built for me by a forum friend. Tubes are Chatham 6AS7G + Tung-Sol 12AU7.



One of the best Crack builds I've seen. Excellent workmanship!

What are the 2 oil bypass caps in the pics?  Their size is perfect.


----------



## Wesley88

cddc said:


> One of the best Crack builds I've seen. Excellent workmanship!
> 
> What are the 2 oil bypass caps in the pics?  Their size is perfect.



I doubled his asking price because of his attention to detail. The caps are Dayton Audio: https://www.parts-express.com/dayto...tm_term=dayton audio&utm_content=Dayton Audio


----------



## cddc (Nov 13, 2020)

Wesley88 said:


> I doubled his asking price because of his attention to detail. The caps are Dayton Audio: https://www.parts-express.com/dayton-audio-dmpc-100-100uf-250v-polypropylene-capacitor--027-447?utm_group={group}&msclkid=ea1cc11e262d1eb95fa59e787a1d394c&utm_source=bing&utm_medium=cpc&utm_campaign=DSA_Dayton-Audio&utm_term=dayton audio&utm_content=Dayton Audio




Thanks a lot for the link. Not sure how much you paid for the building and who built it for you, but it is easily one of the best IMHO. The wiring looks gorgeous.

For comparison my amateur wiring (Speedball was not added yet at that time):


----------



## cddc

GreenNeedle said:


> Then I have a Brimar 6SN7GT on its way.  All of those I haven't tried yet.  I have far too many tubes really for my uses.  I want to find a couple of different combos I like and then sell on the rest.
> 
> So far my go to is the 5998 with either the Mazda 12AU7 or "Tung Sol*" 6SN7GT  *Branded Tung Sol but I think this is the "Raytheon" rebranded as Tung Sol mentioned in post #113 in the 6SN7 thread:
> https://www.head-fi.org/threads/the-6sn7-identification-guide.209782/page-8#post-13476833
> ...



The Tung Sol 6SN7GT you bought is definitely a rebranded Raytheon. Only Ray 6SN7 has these extra supporting rods (5692 not included). A very nice tube. The Brimar is even better, I like it more than the Ray.


----------



## cddc

Wesley88 said:


> I doubled his asking price because of his attention to detail. The caps are Dayton Audio: https://www.parts-express.com/dayton-audio-dmpc-100-100uf-250v-polypropylene-capacitor--027-447?utm_group={group}&msclkid=ea1cc11e262d1eb95fa59e787a1d394c&utm_source=bing&utm_medium=cpc&utm_campaign=DSA_Dayton-Audio&utm_term=dayton audio&utm_content=Dayton Audio




Just checked the Dayton 100uF cap, but I couldn't find "Oil" or "Film"anywhere in its specs. It only mentions "polypropylene capacitor" in its title.

IIRC polypropylene is basically used in most modern caps, even the electrolytic caps use polypropylene as dieletric as well.

But the linked Dayton caps do look like typical Oil Film caps, so are they Oil Film caps? Anyone can confirm?


----------



## JTori

Wesley88 said:


> Crack + Speedball + Mods. Built for me by a forum friend. Tubes are Chatham 6AS7G + Tung-Sol 12AU7.



Nice build! Really well thought through and executed!
Joe.


----------



## bagwell359

cddc said:


> Just checked the Dayton 100uF cap, but I couldn't find "Oil" or "Film"anywhere in its specs. It only mentions "polypropylene capacitor" in its title.
> 
> IIRC polypropylene is basically used in most modern caps, even the electrolytic caps use polypropylene as dieletric as well.
> 
> But the linked Dayton caps do look like typical Oil Film caps, so are they Oil Film caps? Anyone can confirm?



Doubt it, not at that asking price.


----------



## GreenNeedle (Nov 16, 2020)

JTori said:


> Nice build! Really well thought through and executed!
> Joe.


They aren't Oil ones.  I was looking at them when I was deciding what to buy because the price is really good.  They look cool too.  I didn't buy them in the end and bought the Mundorf MKP audiophiler (not the EVO I stated earlier.)  Not because of anything to do with the Daytons really, just that I drank too much port, thought "sod it" and clicked on the Mundorfs.

Then I bought some Clarity Cap ESA to use as bypass on them, hic, hic. lol.


----------



## GreenNeedle

Forcing myself to get on with sorting the crack out seeing as I have a week off.  Today will just be sorting out that crackle.  This is how it looks at the moment, excuse my scruffy work:




This is all to do.  Not today although I may do the ground breaker as well.  In the picture below:
Top left is the new noval socket, below it the ground breaker diodes (only need 2.)  Below that the speedball kit.  Above some spare star washers and risers for the choke and 2 spares.
Then centre at the top we have the cree diodes and little PCB, below that is the choke and below that some cable tie mounts for the film caps.
On the right at the top we have 3 ClarityCap ESA 1uf 250V for bypassing the couplers and the last power cap.  And at the bottom 3 MKP 100uf 250v film caps.  2 for coupling and 1 for the last power cap.  I also have 2 x Clarity Cap ESA 2.2uf to bypass the other 2 electrolytic caps somewhere (must've put them in the wrong parts box. lol.)



I might start the whole thing (the wiring bits) from scratch and tidy it up although I only have 22AWG wire on hand.  Will have to do some research to see if that is OK to use.


----------



## GreenNeedle

Well as seen above I moved the crack into the kitchen as I can work in front of the window.  Turned it upside down with headphones on and power on and prodded away with a wooden kebab skewer and I couldn't get it to crackle.  So I brought in the DAC and laptop and connected that up.  No crackle, prodded away and no crackle, just some microphonic sounds.  Very strange because "in situ" nudging the 12AU7/6SN7 would stop/start the crackle.  Maybe it was the location?  More likely something that was interfering behind the 12AU7 ?  fell out, got moved?

With this in mind I decided to leave the noval socket as is, just replacing a few of the wires that had careless solder burns on their jackets, done the ground breaker mod and returned it back to "situ" to listen for longer for crackles but to no avail.  Listened to 2 albums that are totally innapropriate for this amp.  KLF-White room and Happy Mondays-Pills and Thrills sound much better on solid state (to me) and no crackles at all.

Once the kitchen is available again (had to clear out for cooking and tea-time) I will get myself setup for speedball addition.   I did play earlier with placing for the film caps and have drilled the holes for the Choke.


----------



## GreenNeedle

I am currently re-reading through the whole thread.  Just getting tips on mounting and positioning film caps etc but I have come across a fair amount of posts praising Amperex bugle boys.  I have one of these.  Is this one of these "fabled" tubes?  It has ECC82/12AU7 printed on the tube so not "7316."


----------



## tintinsnowydog

GreenNeedle said:


> I am currently re-reading through the whole thread.  Just getting tips on mounting and positioning film caps etc but I have come across a fair amount of posts praising Amperex bugle boys.  I have one of these.  Is this one of these "fabled" tubes?  It has ECC82/12AU7 printed on the tube so not "7316."


They would be very good tubes. The getter shape is hard to see; is it a halo or a foil getter? The ones from pre-1955 are the most desirable and supposedly sound better; I have not heard any so cannot confirm. They are also very expensive. Let us know how it sounds


----------



## GreenNeedle (Nov 19, 2020)

tintinsnowydog said:


> They would be very good tubes. The getter shape is hard to see; is it a halo or a foil getter? The ones from pre-1955 are the most desirable and supposedly sound better; I have not heard any so cannot confirm. They are also very expensive. Let us know how it sounds


It is a Halo.  As for sound I have only given it 20 minutes or so at this time as it came around the same time as the first a Marconi ECC82 and the first 2 6SN7s.  From memory it wasn't my preference of sound.  Much prefer the Mazda 12AU7 sound but it wasn't bad and not in the bottom half of my tubes.  I would have to give it a bit more time to describe it fully. Bear in mind I'm not overly keen on the (all ECC82) Mullard, Philips Miniwatt or Siemens silver plate which many people rate highly.

Meanwhile I've done some Prep work.  I have made a bracket for the power film cap to sit in (bent a bracket I had into the shape I needed and then wrapped it in some wide heatshrink) which bolts under the rear Octal screw.  I don't want to add any more screws other than the Choke ones which are hidden behind the transformer somewhat.  I'm am far too into aesthetics here I'm afraid.

Then I've de-soldered the last power and output capacitors attaching them to flyleads ready for when the film caps go in.  I saw CDDC's above and copied his. lol.  Resistance and Voltage test (re)passed.  I'm now ready to start on the speedball, hopefully get that done tonight, quick listen then bed, Tomorrow I'll give the speedball version a whirl and report back with my impressions.  If all goes well I am hoping each night to make the next change and get the whole lot of upgrades completed by Monday:


----------



## tintinsnowydog

GreenNeedle said:


> It is a Halo.  As for sound I have only given it 20 minutes or so at this time as it came around the same time as the first a Marconi ECC82 and the first 2 6SN7s.  From memory it wasn't my preference of sound.  Much prefer the Mazda 12AU7 sound but it wasn't bad and not in the bottom half of my tubes.  I would have to give it a bit more time to describe it fully. Bear in mind I'm not overly keen on the (all ECC82) Mullard, Philips Miniwatt or Siemens silver plate which many people rate highly.
> 
> Meanwhile I've done some Prep work.  I have made a bracket for the power film cap to sit in (bent a bracket I had into the shape I needed and then wrapped it in some wide heatshrink) which bolts under the rear Octal screw.  I don't want to add any more screws other than the Choke ones which are hidden behind the transformer somewhat.  I'm am far too into aesthetics here I'm afraid.
> 
> Then I've de-soldered the last power and output capacitors attaching them to flyleads ready for when the film caps go in.  I saw CDDC's above and copied his. lol.  Resistance and Voltage test (re)passed.  I'm now ready to start on the speedball, hopefully get that done tonight, quick listen then bed, Tomorrow I'll give the speedball version a whirl and report back with my impressions.  If all goes well I am hoping each night to make the next change and get the whole lot of upgrades completed by Monday:


A marconi ECC82, is it branded B329? They are very very rare! Halo getter on the bugle boy would indicate later vintage. Many like them but some find them too bright from what I've read. Looking good on the upgrades, hope the film cap installation goes well


----------



## GreenNeedle (Nov 21, 2020)

tintinsnowydog said:


> A marconi ECC82, is it branded B329? They are very very rare! Halo getter on the bugle boy would indicate later vintage. Many like them but some find them too bright from what I've read. Looking good on the upgrades, hope the film cap installation goes well


It says on it ECC82/B329.  I don;t think this is one of the rare ones.  Halo getter, Most online have ECC82 print with B329 below it.  Mine is side by side as typed above.  Has a single seam across the top (half/half) whereas the bugleboy has a cross seam (quarters) on the top.

Upgrades are going well..............although I posted on the bottlehead forum that after the Diode upgrade I had no sound.  Panicked a little, turned out the DAC was switched off at the wall. lol.

Am upgrading in stages and listening.  Will update with those impressions when I am done.  Probably next week some time.


----------



## HiFiHawaii808

GreenNeedle said:


> It says on it ECC82/B329.
> 
> Upgrades are going well..............although I posted on the bottlehead forum that after the Diode upgrade I had no sound.  Panicked a little, turned out the DAC was switched off at the wall. lol.
> 
> Am upgrading in stages and listening.  Will update with those impressions when I am done.  Probably next week some time.


I hate when that happens.   I do that with the input selector on my DAC.


----------



## barbz127

Finally part of the club after having a kit sitting around for a couple of months.

Base crack with brimar cv4003 and tungsol 6080 metal base.

Have parts for mods ready to go:
Speedball 
Blue alps pot with pcb
Panasonic output caps
Cx7 choke

Enjoyed the process of building so much that I've ordered a C2A through their black Friday 15% off deal.


----------



## raindownthunda

barbz127 said:


> Finally part of the club after having a kit sitting around for a couple of months.
> 
> Base crack with brimar cv4003 and tungsol 6080 metal base.
> 
> ...



Very nice!! Look forward to your impressions and comparison between the Crack and C2A (esp with the VC)!


----------



## markkr

I finished my first Bottlehead builds. I bought two so I could have one at the office (which has been closed indefinitely). Both tested perfectly and worked without issue. I plan to buy a Mainline next.

Edit: (I have a set of Speedballs to install next weekend)


----------



## DenverW

Those cracks look really well done!  I've considered moving one of my tube amps to the office, but have gone with a simpler, more portable option (dx220 and he-500).  Well, portable enough to use at my desk, that is.

Crackatwoa is ordered, along with two quiet.  I plan to sell my uber-crack and mod the heck out of the crackatwoa and compare it with the modded mainline.  I've been posting in the amp section for a crackatwoa for 6 months, so I'm glad bottlehead had a sale!  Definetely overspent


----------



## Bruc3

Who is pairing this with the HD800S and what tubes do you find the best and why?

Also anyone happen to compare this to a La figaro 339?


----------



## cddc

GreenNeedle said:


> Then I've de-soldered the last power and output capacitors attaching them to flyleads ready for when the film caps go in.  I saw CDDC's above and copied his. lol.  Resistance and Voltage test (re)passed.  I'm now ready to start on the speedball, hopefully get that done tonight, quick listen then bed, Tomorrow I'll give the speedball version a whirl and report back with my impressions.  If all goes well I am hoping each night to make the next change and get the whole lot of upgrades completed by Monday:




The flyleads is a great idea for folks who plan to upgrade their output bypassing capacitors. I put it down on my must-do list immediately after learning about it.

Unfortunately I had little knowledge on capacitors when building my Crack, didn't know the difference between oil and electrolytic caps, and had no idea what caps/specs to buy.

From the cap mods folks did here(@DenverW , @cebuboy ,  etc), I think I've known what caps to look for. One day I will replace the stock electrolytic caps with some oil caps and utilize the flyleads eventually.  Before that I need to buy a soldering station and polish my soldering skills.


----------



## cddc

barbz127 said:


> Finally part of the club after having a kit sitting around for a couple of months.
> 
> Base crack with brimar cv4003 and tungsol 6080 metal base.
> 
> ...




Very nice build. Did you use the stock boards or your own boards? The grain on your case is quite different than mine. 

I like the finish on your case, what stain/oil did you apply to your case?


----------



## cddc

markkr said:


> I finished my first Bottlehead builds. I bought two so I could have one at the office (which has been closed indefinitely). Both tested perfectly and worked without issue. I plan to buy a Mainline next.
> 
> Edit: (I have a set of Speedballs to install next weekend)




Nice job!

I saw some differences between my old version and your new version:

1.) in my Crack I had to use a pair of twisted wires to connect the left half and the right half of the transformer, while yours don't have that connection. I guess the transformer in my Crack has 2 primaries and I had to join the 2 primaries either in series or in parallel according to the line voltage (either make it 115V or 230V, I guess? ).

2.) the heater wires are now in green (in yours and @GreenNeedle 's). I guess Bottlehead now supplies dedicated green wires for tube heaters?


----------



## barbz127

The more I scroll through this thread the more builds I see with upgraded output caps, chokes etc but no speedball.

Is the speedball just not to everyones taste


----------



## cddc

barbz127 said:


> The more I scroll through this thread the more builds I see with upgraded output caps, chokes etc but no speedball.
> 
> Is the speedball just not to everyones taste





LOL...I dont think so.

My pic shows the Crack before the Speedball upgrade...but if you read carefully you'll find that I had already installed the 3 plastic stands for Speedball. And I did install the Speedball upgrade later and I like it!

People normally build the Crack first, making sure everything works fine with the basic unit, and then upgrade it with speedball.


----------



## DenverW

barbz127 said:


> The more I scroll through this thread the more builds I see with upgraded output caps, chokes etc but no speedball.
> 
> Is the speedball just not to everyones taste



I found the speedball a must, and an excellent upgrade.


----------



## cddc

Speedball is indeed a must IMHO.

It will move the tube operation points into a more linear interval, hence improve the performance of the Crack.


----------



## JTori

markkr said:


> I finished my first Bottlehead builds. I bought two so I could have one at the office (which has been closed indefinitely). Both tested perfectly and worked without issue. I plan to buy a Mainline next.
> 
> Edit: (I have a set of Speedballs to install next weekend)



Very neat builds!  You'll really enjoy them.  And the mainline is exceptional!


----------



## JTori

DenverW said:


> Those cracks look really well done!  I've considered moving one of my tube amps to the office, but have gone with a simpler, more portable option (dx220 and he-500).  Well, portable enough to use at my desk, that is.
> 
> Crackatwoa is ordered, along with two quiet.  I plan to sell my uber-crack and mod the heck out of the crackatwoa and compare it with the modded mainline.  I've been posting in the amp section for a crackatwoa for 6 months, so I'm glad bottlehead had a sale!  Definetely overspent



The Crack-a-two-a is an exceptional amp.  I contemplated modding my Speedballed Crack, but opted for the C2A and couldn't be more pleased.  My upgrades included some top-shelf tubes and a pair of Clarity CSA caps.  Sonic bliss!


----------



## DenverW

After throwing everything I could at my crack it was bound to happen:  I've posted it for sale.  I ran out of improvements and its not possible to scratch the itch to see if I can make it better and better.

...but the Crackatwoa is on the way.


----------



## hmss007

My Crack + Speedball has been built (I had Paul at Bottlehead build it for me) and I'm waiting for my base to be built by a local woodworker, he's making it out of cherry to match my desk and my ZMF headphone stands. Should have the completed kit by this weekend. In the meantime, here's a picture of the unit awaiting it's base.


----------



## PsilocybinCube (Dec 2, 2020)

Bruc3 said:


> Who is pairing this with the HD800S and what tubes do you find the best and why?
> 
> Also anyone happen to compare this to a La figaro 339?


I do.  I use the TS 5998 with a 1942 RCA smoked glass 6SN7 or Ken Rad 6SN7 or Westinghouse Voice of Music 12au7 (courtesy of @DenverW).

The HD 800 needs a bit more bass and oomph.  The 5998 does that well.  Pair it with a warm driver.

@Deyan makes amazing adapters if you have the speedball and want to run the 6sn7.


----------



## cddc

DenverW said:


> After throwing everything I could at my crack it was bound to happen:  I've posted it for sale.  I ran out of improvements and its not possible to scratch the itch to see if I can make it better and better.
> 
> ...but the Crackatwoa is on the way.





I would suggest that you sell your upgraded Crack after you build your Crack-a2a, so that you can compare what differences these "shunt" tubes bring (I have no idea what they do).


----------



## cddc

Two reasons:
1.) you have something excellent to listen to before your Crack-a2a is completed
2.) you can AB the 2 amps and find out what improvement these "shunt" tubes bring


----------



## DenverW

cddc said:


> Two reasons:
> 1.) you have something excellent to listen to before your Crack-a2a is completed
> 2.) you can AB the 2 amps and find out what improvement these "shunt" tubes bring



I like where your head is at, but I need to make some room both on the shelf and in the wallet.  I've been waiting months for certain sales so I went a bit crazy.  Auteur and new cable, along with a crackatwoa has cleaned me out so I sold my hd600 and now the crack has to go.  A headfier is swinging by tomorrow to check it out.

On a side note I created a new cable for it using different wire, and its gooooooooood.  Even better than bottlehead cable which I'd been using.  Once I complete it if it still stands up I'll share.


----------



## GreenNeedle

cddc said:


> Nice job!
> 
> I saw some differences between my old version and your new version:
> 
> ...



I think the transformer has changed since yours so that it can be wired differently for different countries power supplies.  I notice a lot of older cracks have all red/black/white so quite probably a newer addition with the green wires.

I had been a little downhearted because a low level hum I already had became much more noticeable after speedball and other upgrades and was intending to try to alter the wiring especially seeing how tight the heater wires are twisted in Paul's build above.  However I tried a 12AU7 this morning and absolute silence.  Both with the China adaptor and the Garage 1217 adaptor all 4 of my 6SN7s give me a hum so posted on the BH forum to see if anyone has any ideas.  Not a major problem though because I am in the camp of 6SN7 being complimentary to the 12AU7 (and variants of) rather than vastly superior.

This is the before (stock):


And this is the completed upgrade (I have no desire to go further):


I didn't do extensive listening between each upgrade, just 3 CDs into Topping D30 DAC and with Senn 580s. Tubes were Tung Sol 5998 and Mazda (Foreign) 12AU7.:
KLF-White Room - to test how generally it would present EDM type synth/sample music.
Coldplay - Rush of Blood to the head - This album has lots of quiet bits, Crescendo bits, Harmonies Reverb, Electric and acoustic etc.
Marillion - FEAR - This was mainly to test how it handles heavily congested passages of music (Plus I love Marillion.)

I didn't listen to the whole of each album, just certain tracks within each album that I thought would test things.  Although several times when an upgrade had made a great improvement (choke, adding output film caps) I ended up just sitting back and listening to a bit more.

These were my uneducated findings:

Stock Crack with Speedball Upgrade
Tightens up the Bass a little, possibly going a little deeper. Really tightened up the upper mids / treble. Cymbals sound really nice and defined. Has however introduced (or revealed) a sharpness / peakiness to the lower treble / upper mids. Some notes can sound a little sibilant. Mids separation in congested passages is much improved but can still struggle sometimes. If anything the speedball has removed some of the “musicality” or warmth that was so enjoyable with the stock crack.

With Choke Added
This has really made a "WOW" difference. The whole sound has tightened up. Sounds really clear and direct. A bigger change than the speedball made. Seems to have retrieved/discovered some very subtle parts in the music I had never noticed before. Has also removed (or tidied up) that peakiness the speedball "introduced" in the upper mids.

With Cree Diode added
No noticeable change to my ears.

With Output film caps added (new and not burned in.)
This has improved bass power and depth, maybe too much, can sound a little boomy although that may just be from being used to the sound previously. Will take time to appraise things from this point on. It might be that the mids are recessed (as mentioned in post #5,071.) I won’t know until the caps have had the hours put into them. Musicality has returned to the Crack. I’m happy again.

With last power film cap added
Not a huge change IMO in terms of levels but this seems to have discovered even more subtle underlays within tracks. I could say that even more bass depth has appeared but I can’t be sure.

With 1% bypasses to all caps added.
No discernable difference at this point.


----------



## HiFiHawaii808

Does anyone pair ZMF headphones to their Bottlehead Crack?    I'm interested in finding headphones that complement my HD800S, but provide more warmth like the HD650, but better detail retrieval.    I also own HD650 and HD600.


----------



## DenverW

HiFiHawaii808 said:


> Does anyone pair ZMF headphones to their Bottlehead Crack?    I'm interested in finding headphones that complement my HD800S, but provide more warmth like the HD650, but better detail retrieval.    I also own HD650 and HD600.



yes, I’ve tried the auteur and Aeolus in the past, and have a different auteur on the way.  They pair excellently.  Right there with the 800 for some of the best pairings around with Bottlehead amps.


----------



## HiFiHawaii808

DenverW said:


> yes, I’ve tried the auteur and Aeolus in the past, and have a different auteur on the way.  They pair excellently.  Right there with the 800 for some of the best pairings around with Bottlehead amps.


Awesome.  I am leaning toward the Auteur.   I like what I read about the Aeolus, but I am not a big fan of v-shape sound signature.    Is the Auteur different enough from the 800S to be good complementary headphones?


----------



## DenverW

It’s closer than the Aeolus to the 800.  More of a fleshed out lower end (that’s what she said!) with less resolution than the 800.  You can’t go wrong either way, but if you want the biggest difference it would be the Aeolus.


----------



## HiFiHawaii808

DenverW said:


> It’s closer than the Aeolus to the 800.  More of a fleshed out lower end (that’s what she said!) with less resolution than the 800.  You can’t go wrong either way, but if you want the biggest difference it would be the Aeolus.


That's what I get from the reviews.   I'll have to listen to them both to see which one works better for the music I want to listen with them.


----------



## cddc (Dec 7, 2020)

GreenNeedle said:


> I think the transformer has changed since yours so that it can be wired differently for different countries power supplies.  I notice a lot of older cracks have all red/black/white so quite probably a newer addition with the green wires.
> 
> I had been a little downhearted because a low level hum I already had became much more noticeable after speedball and other upgrades and was intending to try to alter the wiring especially seeing how tight the heater wires are twisted in Paul's build above.  However I tried a 12AU7 this morning and absolute silence.  Both with the China adaptor and the Garage 1217 adaptor all 4 of my 6SN7s give me a hum so posted on the BH forum to see if anyone has any ideas.  Not a major problem though because I am in the camp of 6SN7 being complimentary to the 12AU7 (and variants of) rather than vastly superior.
> 
> ...




Excellent job!

All components are nicely aligned. It seems that you've taken the minimalist approach. Only 2 holes were added to the plate (for the choke stands), others were all glued to the plate. I still couldn't figure out how you installed the oil cap for the power supply unit. It's quite tricky to squeeze in a big oil cap in the narrow space between the transformer and the Speedball. So you glued some sticks in between and placed the oil cap on top of them?

I agree with you that Bottlehead has changed the transformer since my time.

Regarding the low level hum, I'm not sure if it is the adapter problem or other problems, but I would recommend you to try the ground breaker approach - add a pair of diodes to the ground tab. See the pair of diodes in @hmss007 's build (top left corner). Details can be found on the BH forum. Not sure if it will solve the problem, but it doesn't hurt to give it a try. Or if you don't care about using 6SN7 tubes, the problem doesn't exist anymore.


----------



## cddc

GreenNeedle said:


> I didn't listen to the whole of each album, just certain tracks within each album that I thought would test things.  Although several times when an upgrade had made a great improvement (choke, adding output film caps) I ended up just sitting back and listening to a bit more.
> 
> These were my uneducated findings:
> 
> ...




Thanks a lot for sharing your findings on various upgrades! 

It seems the choke made a big impact...I am now considering dual chokes


----------



## A Jedi

cddc said:


> I am now considering dual chokes



I did this and couldn’t hear a difference. YMMV


----------



## cddc

A Jedi said:


> I did this and couldn’t hear a difference. YMMV



You mean you couldn't hear the difference between single choke and dual chokes, or single choke vs no choke?


----------



## cddc

Never mind, read your reply again and found you couldn't hear the difference after adding a second choke. It is possible that one choke is enough...


----------



## DenverW

cddc said:


> Never mind, read your reply again and found you couldn't hear the difference after adding a second choke. It is possible that one choke is enough...



Agreed, its diminishing returns for the 2nd choke.  Do a single choke and cree diodes instead.  Cree diodes were cheap and pretty easy to install.  Probably the easiest of the upgrades I did.


----------



## A Jedi

Yup - didn’t hear anything between 1 and 2 chokes.


----------



## GreenNeedle (Dec 7, 2020)

cddc said:


> Excellent job!
> 
> All components are nicely aligned. It seems that you've taken the minimalist approach. Only 2 holes were added to the plate (for the choke stands), others were all glued to the plate. I still couldn't figure out how you installed the oil cap for the power supply unit. It's quite tricky to squeeze in a big oil cap in the narrow space between the transformer and the Speedball. So you glued some sticks in between and placed the oil cap on top of them?
> 
> ...



On the ground breaker suggestion............I did that before speedball. lol:


On the film cap, I had some "s" hooks that were about 1 inch wide flat steel.  1mm or less thickness so easy to bend with clamps or pliers.  S shaped as in squared off corners.  A bit like the old drawing board clips type stuff.  I bent one into a question mark shape but with a tab at the bottom with a hole in it.  The whole thing is covered in some very wide heatshrink apart from the tab which is connected (contacting the chassis plate) under the the rear bolt of the Octal socket.  EDIT-I've missed a hole out on this diagram.  There is another wide hole drilled in the upright just below the cup for the cable tie to go through:


So yes I only drilled 2 holes for the choke. The Crees are supported by another nylon spacer which is just epoxied top and bottom. I just put something with a little bit of weight (but not too much to bend the crees ) on it for a few hours until the epoxy was dry. The Output caps are on cable tie mounts that are epoxied to the chassis. Used too much epoxy and spent an hour getting hardened epoxy out of the holes for the cable ties. lol.

P.S. Mods, Am having problems getting on the site. Certificate issue? Was giving me the following in my usual browser:

*Your connection is not private*
Attackers might be trying to steal your information from *www.head-fi.org* (for example, passwords, messages, or credit cards).


NET::ERR_CERT_DATE_INVALID
Back to safety*Help me understand*


I had to use Chrome then advanced to get onto the site ignoring the "safety" issues.


----------



## HiFiHawaii808

I had the same security issue.  Now it appears to be fixed.


----------



## jonathan c

I am sitting at my comfortable chair in my home office enjoying a new Bottlehead Crack 1.1 with speedball, mega-capacitors, plus. The build quality from James C at The HeadAmp Builder is outstanding. I have been alternating between my HD-600s (custom can mods) and DT-880s (600 ohm). Now I see what the fuss over the BHC is about: dynamics, naturalness, realism! I am happy to be a Cracker...”we hold these truths to be self-evident”...


----------



## cddc

GreenNeedle said:


> On the ground breaker suggestion............I did that before speedball. lol:
> 
> 
> On the film cap, I had some "s" hooks that were about 1 inch wide flat steel.  1mm or less thickness so easy to bend with clamps or pliers.  S shaped as in squared off corners.  A bit like the old drawing board clips type stuff.  I bent one into a question mark shape but with a tab at the bottom with a hole in it.  The whole thing is covered in some very wide heatshrink apart from the tab which is connected (contacting the chassis plate) under the the rear bolt of the Octal socket.  EDIT-I've missed a hole out on this diagram.  There is another wide hole drilled in the upright just below the cup for the cable tie to go through:
> ...




LOL....the ground breaker was indeed installed in your Crack already, it just didn't catch my attention, I guess I focused only on the upgrades when viewing the photos. 

Holding a DIY hook by the octal socket screw is a very innovative idea! The narrow space between speedball and transformer can now be utilized, brilliant!


----------



## Wes S (Dec 8, 2020)

DenverW said:


> yes, I’ve tried the auteur and Aeolus in the past, and have a different auteur on the way.  They pair excellently.  Right there with the 800 for some of the best pairings around with Bottlehead amps.


@HiFiHawaii808 I totally concur with @DenverW on the ZMF's and the Crack.  I own the Aeolus and Atticus, and they sound insanely good on the Crack, and especially with a Bendix 6080WB and Tung Sol Black Glass Round Plate 6SN7GT tube combo.  ZMF dynamics and BHC, go together like PB&J.


----------



## DeweyCH

GreenNeedle said:


> On the ground breaker suggestion............I did that before speedball. lol:
> 
> 
> On the film cap, I had some "s" hooks that were about 1 inch wide flat steel.  1mm or less thickness so easy to bend with clamps or pliers.  S shaped as in squared off corners.  A bit like the old drawing board clips type stuff.  I bent one into a question mark shape but with a tab at the bottom with a hole in it.  The whole thing is covered in some very wide heatshrink apart from the tab which is connected (contacting the chassis plate) under the the rear bolt of the Octal socket.  EDIT-I've missed a hole out on this diagram.  There is another wide hole drilled in the upright just below the cup for the cable tie to go through:
> ...


Their SSL certificate expired. They have since renewed it, it seems. No big deal.


----------



## jonathan c

Ready for action...a la carte portions of musical menu for this evening...Thelonius Monk...Jazz Messengers...Pat Metheny...


----------



## DenverW

jonathan c said:


> Ready for action...a la carte portions of musical menu for this evening...Thelonius Monk...Jazz Messengers...Pat Metheny...



Great photo!  I was just thinking how I'm horrible at taking pictures; I wish I had a better eye like yours


----------



## jonathan c

Thank you DenverW. I actually had to be that close to take the picture since I did not have on my “gogs” (glasses)...


----------



## hmss007

hmss007 said:


> My Crack + Speedball has been built (I had Paul at Bottlehead build it for me) and I'm waiting for my base to be built by a local woodworker, he's making it out of cherry to match my desk and my ZMF headphone stands. Should have the completed kit by this weekend. In the meantime, here's a picture of the unit awaiting it's base.


The base is done and I think it looks good. Sounds even better.


----------



## DenverW

I think it's time to figure out how to do a switchable resistance mod.  My crack has found its way to another headfier, but I have a cracktwoa here now to build, and I'd love to incorporate the ability to switch out 12au7 with 12bh7 and e80cc tubes without having to break out the soldering iron and switch resistors.

Has anyone done a mod like this?  I've investigated some posts that mention particular switches and such, just wondering if there was someone who's brain I could pick.


----------



## cddc

Not sure if Crack_a2a also has the same Speedball? I once looked into it couple of years ago, the way people do it with the original Crack is carried out on the speedball.

They put 2 resistors in parallel to get the desired resistance value on speedball, and they add a 2-way or 3-way switch to toggle among different optimal resistance values on the speedball.


----------



## cddc

I normally do not run these 12BH7's or E80CC's, so did not go that route.


----------



## DenverW

Hmmm...the parallel switch is a good idea, and isn't so complicated that it makes me want to give up on it.  

I think one of the big appeals I have to the idea, besides really liking e80cc tubes, is that 12au7 and 6sn7 tubes are getting a bit out of control, so having the option to substitute is good.  Also, i'm a tube rolling addict.


----------



## Tom-s

If there’s a bunch of interest in this switch board. I’m willing to design a board or kit for this.
Like if interested.


----------



## DenverW

Tom-s said:


> If there’s a bunch of interest in this switch board. I’m willing to design a board or kit for this.
> Like if interested.



I have multiple personalities, so my like counts for a bunch.


----------



## jonathan c

These just arrived...I cannot wait to “torque up” the BHC with 421a....akin to Mustang 421 cubic inch V8?....


----------



## cddc

jonathan c said:


> These just arrived...I cannot wait to “torque up” the BHC with 421a....akin to Mustang 421 cubic inch V8?....




These WE 421A's should have the same specs (gain, transconductance, voltage/current, etc) as the Tung Sol 5998's - see my research on 421A vs 5998 pages earlier.

WE 421A seems much rarer than TS 5998 (or maybe not, due to all these Western Electric believers / hoarders ), so it fetches a much higher price than 5998. Congrats on the new acquisition! They seem to be in good condition, new in box?


----------



## jonathan c

Yes, NIB


----------



## cddc

Tom-s said:


> If there’s a bunch of interest in this switch board. I’m willing to design a board or kit for this.
> Like if interested.



Switch board is a great idea! I would have clicked on the like button...but I had few 12BH7/E80CC tubes.

Switch board brings more possibilities than a 3-way switch, which offers only 3 sets of resistance values.

I recommend using jumpers to choose different resistance values.


----------



## jonathan c

Blue Note bop, Bottlehead, Brimar, Western Electric: on a snowy Saturday eve, my favourite foursome off the golf course.


----------



## trigeminalv3

Hello all, I thought I'd share some pics of my bottlehead crack to add to the gallery. W/ speedball, Tung sol 5998, Mullard CV 4003, purple heart wood base, purple textured powdered coat on the top plate. Built by Paul B at Bottlehead. 

I put it up for sale but I'm somewhat conflicted. I tried the verite closed/open, auteur, and utopia but the performance hasn't really connected with me. The same was true with the ZMF pendant (I did prefer the BHC to this though). I figured maybe I'm just not into tube amps.. 

What headphones are known to bring out the best of the crack? HD650?


----------



## DenverW

trigeminalv3 said:


> Hello all, I thought I'd share some pics of my bottlehead crack to add to the gallery. W/ speedball, Tung sol 5998, Mullard CV 4003, purple heart wood base, purple textured powdered coat on the top plate. Built by Paul B at Bottlehead.
> 
> I put it up for sale but I'm somewhat conflicted. I tried the verite closed/open, auteur, and utopia but the performance hasn't really connected with me. The same was true with the ZMF pendant (I did prefer the BHC to this though). I figured maybe I'm just not into tube amps..
> 
> What headphones are known to bring out the best of the crack? HD650?



The utopia doesn’t pair with the crack based on its impedance, but the zmf cans should all sound great.  If there is another amp you prefer then you might be right and tubes aren’t your thing.  What is your source chain?


----------



## trigeminalv3

DenverW said:


> The utopia doesn’t pair with the crack based on its impedance, but the zmf cans should all sound great.  If there is another amp you prefer then you might be right and tubes aren’t your thing.  What is your source chain?


That makes sense as the Utopia-BHC pairing was outright dismal. I love my Pass Labs HPA-1. The experience I get with the Utopia is what I imagined hifi would be. My DAC is the aqua la voce s3. Macbook pro 2019 touch bar as the source.


----------



## DenverW

trigeminalv3 said:


> That makes sense as the Utopia-BHC pairing was outright dismal. I love my Pass Labs HPA-1. The experience I get with the Utopia is what I imagined hifi would be. My DAC is the aqua la voce s3. Macbook pro 2019 touch bar as the source.



I think you’re looking apples to oranges there. The pass labs is about 8x the price of the crack for stock kits, and the utopia probably sounds great out of it (I haven’t heard it). I think it’s not that you don’t like tubes, but that you’re comparing imho the absolute best entry level tube amp with summit fi gear. It’s still a basic tube amp at the end of the day. The Pendant though should be another matter. I haven’t heard it so I can’t sya definitely, but if you’re used to the utopia sound the zmf gear on tubes may be too relaxed. I would give two weeks without listening to the passlabs to let your ears adjust to see if you change your mind.

Im the complete opposite; I’ll never go back to solid state amps after I fell in love with tube gear.  It just sounds too clinical to me.


----------



## trigeminalv3

DenverW said:


> I think you’re looking apples to oranges there. The pass labs is about 8x the price of the crack for stock kits, and the utopia probably sounds great out of it (I haven’t heard it). I think it’s not that you don’t like tubes, but that you’re comparing imho the absolute best entry level tube amp with summit fi gear. It’s still a basic tube amp at the end of the day. The Pendant though should be another matter. I haven’t heard it so I can’t sya definitely, but if you’re used to the utopia sound the zmf gear on tubes may be too relaxed. I would give two weeks without listening to the passlabs to let your ears adjust to see if you change your mind.
> 
> Im the complete opposite; I’ll never go back to solid state amps after I fell in love with tube gear.  It just sounds too clinical to me.


How does the crack compare to something like the woo audio WA22 (or really anything in that $2500 range)? What improvements should you expect as you move up that tube amp price ladder?

I'm not sure what I was expecting out of the BHC. Reading about made it seem that it had a sound all its own, even among tube amps. It definitely sounded wildly different from the pendant. I figured it occupied its own one amp niche..that it's not a reflection of what tube amps are, just what the signature bottlehead sound is. 
It makes me wonder whether being conflicted on the BHC is more or less how I will feel about tube amps as a whole.

But yeah I love a sharp/technical/clinical sound.


----------



## DenverW

Well base crack is much more "tubish" in sound.  When you add the speedball it tightens up a bit.  Also, I find the 5998 tube a more clear, clinical sounding tube.  So your crack is probably running more to the clinical angle right now (as far as cracks go), and may just seem like a less impressive SS amp.  My crack was about as upgraded as I could make it (speedball, chokes, cree diodes, cap upgrades, bypass caps, alps potentiometer) and it didn't have the clarity of my bottlehead mainline.  However, I did like the extra lushness and impact the crack had, so I'm working on a crackatwoa amp right now to see if I prefer it to the mainline amp.

If you want something very different from your SS amp, I would say put in a lusher tube or two and give it a whirl for a while to let your ears get used to the different type of sound.  When I went from the crack to a SS amp I found the sound too dull and lifeless for my taste.


----------



## PsilocybinCube

DenverW said:


> Well base crack is much more "tubish" in sound.  When you add the speedball it tightens up a bit.  Also, I find the 5998 tube a more clear, clinical sounding tube.  So your crack is probably running more to the clinical angle right now (as far as cracks go), and may just seem like a less impressive SS amp.  My crack was about as upgraded as I could make it (speedball, chokes, cree diodes, cap upgrades, bypass caps, alps potentiometer) and it didn't have the clarity of my bottlehead mainline.  However, I did like the extra lushness and impact the crack had, so I'm working on a crackatwoa amp right now to see if I prefer it to the mainline amp.
> 
> If you want something very different from your SS amp, I would say put in a lusher tube or two and give it a whirl for a while to let your ears get used to the different type of sound.  When I went from the crack to a SS amp I found the sound too dull and lifeless for my taste.


Second this.  I have a sennheiser hdva 600 which is a nice SS amp but it's not as enjoyable as the BHC.


----------



## raindownthunda (Dec 28, 2020)

DenverW said:


> Well base crack is much more "tubish" in sound.  When you add the speedball it tightens up a bit.  Also, I find the 5998 tube a more clear, clinical sounding tube.  So your crack is probably running more to the clinical angle right now (as far as cracks go), and may just seem like a less impressive SS amp.  My crack was about as upgraded as I could make it (speedball, chokes, cree diodes, cap upgrades, bypass caps, alps potentiometer) and it didn't have the clarity of my bottlehead mainline.  However, I did like the extra lushness and impact the crack had, so I'm working on a crackatwoa amp right now to see if I prefer it to the mainline amp.
> 
> If you want something very different from your SS amp, I would say put in a lusher tube or two and give it a whirl for a while to let your ears get used to the different type of sound.  When I went from the crack to a SS amp I found the sound too dull and lifeless for my taste.



I'm curious about how the other Bottlehead amps compare with ZMF headphones but haven't heard them yet.

Have you tried different tubes for the crack?

It takes some experimentation but finding a good combination of tubes with the best synergy for your chain can be totally worth it. Check the 6j5 thread for impressions.

If you are willing to run an adapter, check out the 6sn7 or 6j5 (dual) adapters. @Deyan makes a great 12au7 -> dual 6j5 adapter that works with a number of 6j5/6c5/L63 tubes... I'm doubtful that you can "roll you way" to a $1k+ amp, but IME finding the right combintation of power & driver tubes that really make your chain come to life is absolutely worth the experimentation it takes to get there.


----------



## DenverW

I’ve tried the 6j5 series but preferred the dual cv6 or e1148 tubes to it.  I still prefer 12au7 on the crack overall .


----------



## Wes S

DenverW said:


> I’ve tried the 6j5 series but preferred the dual cv6 or e1148 tubes to it.  I still prefer 12au7 on the crack overall .


Right there with ya!  I have rolled 6sn7, 6j5, and 12au7, and the 12au7's are staying in my BHC.  I thought I liked the 6SN7's more for a while, and just recently rolled my 12au7's back in, and I like them the most.  Love the BHC for when I just want to relax and listen to some old blues or classic rock.


----------



## tintinsnowydog (Dec 30, 2020)

Inspired by some recent posts here and on the 6J5 thread, I decided to do a mini shoot-out of the 'top' 12AU7/ECC82s. I was recently loaned an Amperex 7316, generously by a fellow BHC owner on another forum. Their market price is above and beyond what I'd be willing to pay for these mini guys, so I am super thankful I get to test them out! Other tubes were the Telefunken smooth plate ECC82, Hivac smooth welded plate CV491, and a regular Mullard Blackburn Gf1 (1963) ECC82. I then compared them to a pair of Mullard 6J5GT tubes. The listening was conducted with a 5998 to maximise the input tube's abilities, and HD800 to hear every detail available.  I have tried to summarised each tube's characteristics in 3 words as well as some listening notes as I went along, both for my own quick reference in future and for anyone who wants to get a brief idea of their differences 

For reference, I find that the 12AU7 family is a little grainy and harsh, especially in the top registers. It is not as obvious with my HD650s, but most 12AU7s, bar the best of the best, exhibit this problem- sometimes painfully so- through the HD800. I presume this is due to the tube not being as linear as it could be. That is what I refer to as grain below!

*Amperex 7316- airy, detailed, light.*
-Very detailed across all frequencies, effortlessly airy and spacious presentation.
-Does NOT suffer overtly from treble grain problem, but can be a little fatiguing on very high notes; not as smooth as a good treble could be. The slightest hint of graininess can sometimes be detected on a few notes.
-Sonorous, well-extended bass, but lacking some weight at times (decreased upper bass, and a little unbalanced emphasis from higher frequencies may have contributed)
-A little lean/timbre was off at times; emphasis in upper mids may contribute to this.
-Forward presentation gives impression of a somewhat more intimate soundstage; but it is actually quite wide, although not as deep as some other tubes.
-Very neutral and detailed presentation overall, skewed slightly away from low end, and towards the treble. 'Light and fast'.
-Vocals sound incredibly life-like.
-Overall not as smooth as Telefunken or Hivac (below).


*Telefunken ECC82- detailed, balanced, refined.*
-Beautifully detailed and sparkly top end with no hint of grain.
-Well extended in both directions; possibly slightly bright at the top end, but smoothly so and thus never fatiguing.
-Slightly less detail and texture below treble regions compared to Hivac, but is as smooth or even slightly smoother in treble region with equal detail and treble extension.
-Very spacious sounding, bass and mids are warm and full with appropriate weight.
-Very similar presentation to the 7316, but a touch smoother and possibly more balanced in exchange for a tiny bit less detail, airiness, lightness.


*Mullard Gf1 Blackburn ECC82- warm, full-bodied, tonally-pleasant.*
-Lots of weight and body to the sound; makes the 7316 sound a little lean and polite in comparison.
-Less overall clarity and grain on the top end.
-A little muddy especially in upper bass/lower mids, but pleasantly warm in presentation.
-More diffuse and rounded ('warm'), but also with better tonality across the frequency range.
-Slightly more texture on 'attack' in lower frequencies up to lower mids compared to 7316.
-Wider and deeper perception of stage space than 7316.
-Overall, not as smooth or refined as 7316.


*Hivac CV491 detailed, powerful, expansive.*
-Put simply; does everything the 7316 does, but better!
-Insanely detailed, still can hear more even when at 2dB less volume.
-Incredible weight and depth to each note.
-Most accurate timbre.
-Treble is superbly extended yet without a hint of grain.
-Most powerful, textured bass.
-All frequencies very balanced; nothing obscured.
-Very smooth and musical mids, superb vocals but perhaps not as airy as the 7316.


*Mullard 6J5GT -warm, smooth, laid-back.*
-Soundstage as well as overall presentation is clearly wider, airier and better separated compared to ALL 12AU7s.
-Persistently noticing a more powerful, weighty presentation.
-Simply more linear and balanced sounding, with better extension in both directions compared to all 12AU7s.
-Treble is much smoother even than the Hivac and Telefunken, while it is just as detailed.
-Warm and controlled, with an expansive sound.


Overall, I felt a little more to be desired from the 7316 despite its high price and rave reviews. It sat halfway between a Mullard and Telefunken, and with the airiest presentation of all the tubes. It would definitely be my go to for vocal music, which I think it excels at better than all of the other tubes I tested. The Hivac CV491 is still my favourite 12AU7 variant; however, I feel the 6J5s are still a leap above even the CV491, inasmuch as the CV491 is better than the Gf1 Mullard ECC82. The Gf1 Mullard is best for a relaxed presentation, the Telefunken best for classical music, the CV491and 6J5 as all rounders with hard hitting low-end and sparkly treble.

Happy holidays everyone, keep safe, and have a Happy New Year!


----------



## Wes S

tintinsnowydog said:


> Inspired by some recent posts here and on the 6J5 thread, I decided to do a mini shoot-out of the 'top' 12AU7/ECC82s. I was recently loaned an Amperex 7316, generously by a fellow BHC owner on another forum. Their market price is above and beyond what I'd be willing to pay for these mini guys, so I am super thankful I get to test them out! Other tubes were the Telefunken smooth plate ECC82, Hivac smooth welded plate CV491, and a regular Mullard Blackburn Gf1 (1963) ECC82. I then compared them to a pair of Mullard 6J5GT tubes. The listening was conducted with a 5998 to maximise the input tube's abilities, and HD800 to hear every detail available.  I have tried to summarised each tube's characteristics in 3 words as well as some listening notes as I went along, both for my own quick reference in future and for anyone who wants to get a brief idea of their differences
> 
> For reference, I find that the 12AU7 family is a little grainy and harsh, especially in the top registers. It is not as obvious with my HD650s, but most 12AU7s, bar the best of the best, exhibit this problem- sometimes painfully so- through the HD800. I presume this is due to the tube not being as linear as it could be. That is what I refer to as grain below!
> 
> ...


Good stuff!  There are a few more top tier 12au7's, that might give different/better results (less grain up top)  but you do have some good ones.


----------



## PsilocybinCube (Dec 30, 2020)

Hello fellow tube addicts.  I need help and your opinion.

I'm looking to purchase a new pair of headphones for my recently improved (asthetically) BHC which I will post pics of soon.  I'm looking for some new headphones and interested if anyone has opinions on what to buy at around the $1,000 - $1,500 mark.  There's the ZMF lineup and I am intrigued by the Auteur and the Eikon, but I'm wondering if there is another good option I may be missing.

I do have the Speedball upgrade along with some other upgrades courtesy of @DenverW

I mostly listen to jazz, indie rock/folk, and classical.

Thoughts?

Edit:  I own the HD800 and love the sound of those.  Of course, bit more bass would be nice but detail and wide stage is certainly preferred.

I'm selling my HD650 headphones as (though I like them) I want a relatively significant upgrade from those.


----------



## DenverW

PsilocybinCube said:


> Hello fellow tube addicts.  I need help and your opinion.
> 
> I'm looking to purchase a new pair of headphones for my recently improved (asthetically) BHC which I will post pics of soon.  I'm looking for some new headphones and interested if anyone has opinions on what to buy at around the $1,000 - $1,500 mark.  There's the ZMF lineup and I am intrigued by the Auteur and the Eikon, but I'm wondering if there is another good option I may be missing.
> 
> ...



zmf auteur is a good change of pace, with better bass than the hd800. You’re going to sacrifice some soundstage, and a small amount of detail, but you just can’t beat the 800 for those. An Aeolus is another option if you’re looking for complimentary headphones, as it has a bit different sound than the 800 or auteur.
Honestly, though, for OTL amps like the crack there aren’t a lot of options better than the 800.  

If you have the funds I’d try both those zmf, and resell the one or two headphones you prefer less.

We could also talk about a new amp or more upgrades to your crack.


----------



## PsilocybinCube

DenverW said:


> zmf auteur is a good change of pace, with better bass than the hd800. You’re going to sacrifice some soundstage, and a small amount of detail, but you just can’t beat the 800 for those. An Aeolus is another option if you’re looking for complimentary headphones, as it has a bit different sound than the 800 or auteur.
> Honestly, though, for OTL amps like the crack there aren’t a lot of options better than the 800.
> 
> If you have the funds I’d try both those zmf, and resell the one or two headphones you prefer less.
> ...


So I have the hd800 on my amp from Paladin (another head-fier) and it lives at my home office.  My BHC will live at work and there I'm looking for something purely musical.  Maybe I should buy another hd800...I do love them.


----------



## DenverW

PsilocybinCube said:


> So I have the hd800 on my amp from Paladin (another head-fier) and it lives at my home office.  My BHC will live at work and there I'm looking for something purely musical.  Maybe I should buy another hd800...I do love them.



Do you need any sort of isolation?


----------



## PsilocybinCube

DenverW said:


> Do you need any sort of isolation?


No I have a suite and plenty of noise isolation.  My staff is fairly removed and I can't hear them even if they were in a phone conference.

We built a new office right as COVID started and I built it for audio and confidentiality/low noise transfer.  I have magnepan .7s in one of my offices where I meet with clients but my office where I spend most of time is just built tight as a drum and very quiet.  That's the office the BHC will go in.  I've been using an HDVA 600 amp with the 650 which is a bit of a dark (but good) pairing.  I miss my BHC desperately and spend so much time listening to music I would like to invest in a nice new set of headphones.  

Tubes will likely be the 5998 and Westinghouse Voice of Music 12au7 (the 12au7 also c/o @DenverW ).  I also run a 6sn7 pretty often in the amp.


----------



## DenverW

Cool!  I would try the auteur then.  I find that in the office it’s a combination of sound and comfort, so you have two types of headphones to choose from.  Also, let’s PM a bit so you can remind me what upgrades are in that crack; maybe I can recommend some I didn’t do.


----------



## markkr

Sold both of my Cracks this week... Crackatwoa inbound!


----------



## JamieMcC

PsilocybinCube said:


> Hello fellow tube addicts.  I need help and your opinion.
> 
> I'm looking to purchase a new pair of headphones for my recently improved (asthetically) BHC which I will post pics of soon.  I'm looking for some new headphones and interested if anyone has opinions on what to buy at around the $1,000 - $1,500 mark.  There's the ZMF lineup and I am intrigued by the Auteur and the Eikon, but I'm wondering if there is another good option I may be missing.
> 
> ...



No need to change the hd800 build a Bottlehead Mainline.


----------



## DenverW

JamieMcC said:


> No need to change the hd800 build a Bottlehead Mainline.



Keeping my Hd800, but he zmf auteur/Aeolus is enough of a contrast with the mainline that I’m glad I got it.  Right now the Auteur is the new girl in school, so it’s getting all my attention.  Time will tell if things even out, or if I drift back to the 800 more.


----------



## PsilocybinCube

JamieMcC said:


> No need to change the hd800 build a Bottlehead Mainline.


I have a dedicated setup at home for the hd800.  The other pair in question is for the office.  I'd rather have two different pairs of headphones. 

The setup at home is the HD800 paired with my Incubus Elegant from @Paladin79 .  The work setup is where my BHC will reside.  So, not replacing the HD800.  I'm replacing the HD650 which was previously at work.  

The HD800 has spoiled me.for soundstage and HD650 is more....intimate.  the best would be an HD800 soundstage with a bit more oomph.  Of course tubes give the oomph(as can something like a Schitt Loki), but I want something that is naturally more bass forward for my second headphone that will live at the office.o


----------



## raindownthunda (Jan 2, 2021)

PsilocybinCube said:


> I have a dedicated setup at home for the hd800.  The other pair in question is for the office.  I'd rather have two different pairs of headphones.
> 
> The setup at home is the HD800 paired with my Incubus Elegant from @Paladin79 .  The work setup is where my BHC will reside.  So, not replacing the HD800.  I'm replacing the HD650 which was previously at work.
> 
> The HD800 has spoiled me.for soundstage and HD650 is more....intimate.  the best would be an HD800 soundstage with a bit more oomph.  Of course tubes give the oomph(as can something like a Schitt Loki), but I want something that is naturally more bass forward for my second headphone that will live at the office.o



The Aeolus has excellent "oomph" for an open back, especially with the stock (lambskin) pads and an OTL amp. I think it would be a pretty good upgrade to the HD650. I went from the 58x and JDS Labs Atom to the Aeolus w/ BHC and there was a fairly dramatic improvement in soundstage (both width and 3d/depth), instrument separation/layering, and bass quality+quantity. As I'm sure you're already familiar, tube rolling with the BHC can make a pretty big difference. Currently using the Bendix 6080WB, Tung Sol 6J5G (x2 with @Deyan  adapter), Bifrost 2, and ZMF Aeolus with with perf. suede universe pads... This is pretty much the perfect combo for me with tube rolling to keep things interesting and varied. The Aeolus is truly a chameleon and can change quite a bit with pad rolling, so there are many different variables you can experiment with between the headphones and tubes with the BHC to find a winning combo for your personal tastes. Can't compare the Auteur as I haven't heard that one yet, but from what I''ve read it seems the Aeolus is warmer than the Auteur, so maybe more of an analog to the HD650?


----------



## Paladin79

PsilocybinCube said:


> I have a dedicated setup at home for the hd800.  The other pair in question is for the office.  I'd rather have two different pairs of headphones.
> 
> The setup at home is the HD800 paired with my Incubus Elegant from @Paladin79 .  The work setup is where my BHC will reside.  So, not replacing the HD800.  I'm replacing the HD650 which was previously at work.
> 
> The HD800 has spoiled me.for soundstage and HD650 is more....intimate.  the best would be an HD800 soundstage with a bit more oomph.  Of course tubes give the oomph(as can something like a Schitt Loki), but I want something that is naturally more bass forward for my second headphone that will live at the office.o


You do have a couple options if you do not mind me butting in.    Use the 800's with the Crack, I run an Incubus Elegan with 50 and 80 ohm headphones and it does quite well. Some use 32 ohm, one audiophile is use lower impedance than that lol but 50 ohms up is my preference. You have one of the later Incubus amps and headphones like Focal Utopias are my pick but they can be rather pricey. I also want to try the ZMF Verite but have not yet. Friends and I do run four of the Incubus amps with HD800's for blind tube comparison and they are always an excellent choice IMHO.


----------



## PsilocybinCube

Paladin79 said:


> You do have a couple options if you do not mind me butting in.    Use the 800's with the Crack, I run an Incubus Elegan with 50 and 80 ohm headphones and it does quite well. Some use 32 ohm, one audiophile is use lower impedance than that lol but 50 ohms up is my preference. You have one of the later Incubus amps and headphones like Focal Utopias are my pick but they can be rather pricey. I also want to try the ZMF Verite but have not yet. Friends and I do run four of the Incubus amps with HD800's for blind tube comparison and they are always an excellent choice IMHO.


You are right, I could keep the HD800 with the BHC.  I need to try to demo some Focals with the Incubus.  The BHC has responded so poorly to all the low impendance headphones I've ever run at it before that it makes me very nervous to pair a something low impedance with an OTL amp.


----------



## Paladin79

PsilocybinCube said:


> You are right, I could keep the HD800 with the BHC.  I need to try to demo some Focals with the Incubus.  The BHC has responded so poorly to all the low impendance headphones I've ever run at it before that it makes me very nervous to pair a something low impedance with an OTL amp.


Yeah as best I recall you need at least 150 ohm up for the Crack, 50 ohm up for the Incubus is realistic.


----------



## cddc (Jan 11, 2021)

Differences between headphones in terms of Taylor Swift     - for your amusement


----------



## jonathan c

Brimar CV4003’s new Bottlehead neighbour with clean pins just for the occasion.


----------



## GreenNeedle

cddc said:


> Differences between headphones in terms of Taylor Swift     - for your amusement


Lol @ Beats.  Surprised it isn't next to the bass drum with the bass amp right next to it, a thick blanket over both and everyone/thing else far into the distance on the horizon.


----------



## GreenNeedle

I'm putting lots of testing time into my crack at the moment.  Fully motivated:


----------



## cddc

GreenNeedle said:


> Lol @ Beats.  Surprised it isn't next to the bass drum with the bass amp right next to it, a thick blanket over both and everyone/thing else far into the distance on the horizon.






Yes, with @ Beats it is right next to the bass drum...LOL 






Quite slippery outside, stay home and stay safe. Good luck with the Crack and hope it will recover soon!


----------



## DenverW

So, I am going to entitle this post:  The Frustration with the Crackatwoa.

Having built and modded a crack and speedball.  I've really been excited to get my hands on a crackatwoa kit.  Black friday sale was just the ticket, and I've been taking my time (cause I have no time) to get to the build.  Worked the base...stained...lacquer...looks pretty good for my usually screw ups. 

First issue comes from mounting the sockets into the chassis.  One of the sockets is too large.  Since I'm a manly man, I try to force it.  It crumbles in my hand.  Well, that was a mistake.  I order a new socket.

Meanwhile I finish mounting the other components, and wire the power supply.  First power test!  Zippo.  No power.  Is my volt-o-meter broken?  Nope.  After troubleshooting, resoldering all the connections, and getting annoyed, I guess that its a faulty fuse.  Amazon to the rescue.  I order more fuses.

Fuses arrive two days later.  I was right, the fuse I was sent was bad.  Everything tests within the parameters.  I continue wiring.

Socket arrives!  I determine that the hole in the chassis was cut too small.  I spend a significant amount of time shaving and sanding out the chassis to get the socket to fit.  Finally it does.  I don't break this one (yet).

Ok, time to finish mounting the stand offs around the last socket.  Well guess what?  I'm short two screws.  Before you ask, YES, i'm positive I'm short, as I put all the components in an ice cube tray with a plastic cover to keep them separate and secure.  All screws gone.  Two screws needed.  Tomorrow will be Home Depot.

I love Bottlehead.  This build is cursed though.  If you're thinking of building the crackatwoa be aware that its not a step up in complication from the crack, its a LEAP.


----------



## cddc

Looks like a tough project, especially with the defects and missings. But with your experience of 2-ish Cracks, I think it will eventually shine.


----------



## jonathan c

Loving and hard bopping to the combination of Tung Sol 5998 and Brimar CV4003...deep, full bass...solidly dimensional midrange...pure treble...👂👂


----------



## Pimmsley (Jan 16, 2021)

My modded build before ifinal nput wiring, also Triad cx-7 choke not in pic as it's mounted in the temporary case... waiting for my mate to finish the Tasmanian dark wood cabinet.

Cheers.


----------



## jonathan c

Pimmsley said:


> My modded build before ifinal nput wiring, also Triad cx-7 choke not in pic as it's mounted in the temporary case... waiting for my mate to finish the Tasmanian dark wood cabinet.
> 
> Cheers.


I like the interim cabinet too.


----------



## A Jedi

Pimmsley said:


> My modded build before ifinal nput wiring, also Triad cx-7 choke not in pic as it's mounted in the temporary case... waiting for my mate to finish the Tasmanian dark wood cabinet.
> 
> Cheers.



Sexy build. Another vote for the temp case


----------



## Pimmsley (Jan 16, 2021)

jonathan c said:


> I like the interim cabinet too.



Cheers !
Amazon cardboard can be quite useful at times 












N.B. My build is for personal use (non-commercial)


----------



## cddc

DenverW said:


> zmf auteur is a good change of pace, with better bass than the hd800. You’re going to sacrifice some soundstage, and a small amount of detail, but you just can’t beat the 800 for those. An Aeolus is another option if you’re looking for complimentary headphones, as it has a bit different sound than the 800 or auteur.
> Honestly, though, for OTL amps like the crack there aren’t a lot of options better than the 800.
> 
> If you have the funds I’d try both those zmf, and resell the one or two headphones you prefer less.
> ...




Great review on the amf headphones! I've heard lots of good things about them. 

The only concern to me is their weights. Anything above 400g would be too heavy to wear, including these planars and Focal headphones.


----------



## cddc

Just for comparison, my HD650 weighs 9.1 oz / 260g and my HD800 weighs 11.6 oz / 329g, they are both very comfortable to wear.

I once tried the Audeze LCD-2 (around 580g), and soon suffered fatigue.  I think they are spine / disc destroyers


----------



## HiFiHawaii808

DenverW said:


> zmf auteur is a good change of pace, with better bass than the hd800. You’re going to sacrifice some soundstage, and a small amount of detail, but you just can’t beat the 800 for those. An Aeolus is another option if you’re looking for complimentary headphones, as it has a bit different sound than the 800 or auteur.
> Honestly, though, for OTL amps like the crack there aren’t a lot of options better than the 800.
> 
> If you have the funds I’d try both those zmf, and resell the one or two headphones you prefer less.
> ...


I finally did it.  I bought a ZMF Verite Closed.    I wanted something really fun to complement my HD800S for listening to with my BHC.   I am so excited about it.


----------



## DenverW

cddc said:


> Great review on the amf headphones! I've heard lots of good things about them.
> 
> The only concern to me is their weights. Anything above 400g would be too heavy to wear, including these planars and Focal headphones.



I hear you on the weight factor.  One reason why I steer away from old style headbands on audeze headphones.  The lcdc2 was pretty fatiguing to wear.  The auteur are heavy, but well distributed.  To me the positive is it FEELS like a more solid headphone than the hd800, which I like.  They hug my head a bit more.  The hd800 comfort level is overall better though, due to their light weight and looser fit.  I'm good with both.


----------



## markkr

DenverW said:


> So, I am going to entitle this post:  The Frustration with the Crackatwoa.
> 
> Having built and modded a crack and speedball.  I've really been excited to get my hands on a crackatwoa kit.  Black friday sale was just the ticket, and I've been taking my time (cause I have no time) to get to the build.  Worked the base...stained...lacquer...looks pretty good for my usually screw ups.
> 
> ...



My Crackatwoa arrived on friday, hopefully I have better luck.


----------



## DenverW

markkr said:


> My Crackatwoa arrived on friday, hopefully I have better luck.



Got some screws from Home Depot so it’s back on!


----------



## cddc

jonathan c said:


> Loving and hard bopping to the combination of Tung Sol 5998 and Brimar CV4003...deep, full bass...solidly dimensional midrange...pure treble...👂👂



Great looking Crack, may I ask what wood or stain is used?


----------



## jonathan c

cddc said:


> Great looking Crack, may I ask what wood or stain is used?


 PM response...


----------



## HiFiHawaii808

I finally got my ZMF Verite Closed headphones yesterday.   I tried them out with most of my AMPs/DACs and my favorite pairing is

Tidal > Bluesound Node 2i > Hugo 2 > BHC > VC.  It's truly amazing sound and very complementary to my HD800S cans.    I am going to replace my Modi Multibit with a Bifrost 2 shortly and expect that this will be my primary listening set up for my ZMF headphones.   I was using the Hugo 2 until I could get the Mimby replaced.   My Hugo 2 is going to be used for my IEMs.


----------



## InstantSilence

Is this amp powerful?


----------



## cddc

InstantSilence said:


> Is this amp powerful?




Very powerful on high impedance headphones, like HD600/650/800S/T1/DT880/etc


----------



## cddc

Just watching Metallica in one of the highest-attended rock & roll live concerts, and this comment is killing me....LMAO


----------



## cddc

Well, the forum automatically cuts the F letter off from the word LM*F*AO, how convenient!


----------



## bagwell359

InstantSilence said:


> Is this amp powerful?



Seems to drive cans better than SS amps that should pound it on paper.  My Rag 1 puts out like 3 times the juice into 300 than the BHC, but it doesn't sound like it.  Bass is also much stronger sounding, but, based on what I know its a great audio result, but the amount of D & THD takes a big jump with the BHC.  Put it this way there is no reason in my home system to run the HD-600 on the Rag 1 once the BHC came on-line - except to shock people.


----------



## Tom-s (Jan 28, 2021)

The Crack puts out 300mw into 300 Ohm or more. It manages to keep the output power constant with higher impedances. But can't on low impedance cans. This is a result of the OTL output stage. If you'd want to use a SS or other amp that provides 300mw into 300 Ohms. Assuming power halves when impedance is doubled in most amplifiers (SS / transformer coupled tube amps) this would equate to roughly 5-10W of power into 8Ohms as given by most manufacturers.
That's why your Crack sounds more powerful into high impedance cans; it is. Ever more so when it comes to hard to drive headphones like AKG K340's with impedances up to 800 Ohms. A normal amp struggles with cans like these because of the harsh impedance curve and people recommend to run them from speaker amps as a result; the Crack just sings like none other.


----------



## bagwell359 (Jan 28, 2021)

Tom-s said:


> That's why your Crack sounds more powerful into high impedance cans; it is.



But its NOT more powerful on paper.  My Rag 1 (100 wpc/4 ohms, 15 wpc/50 ohms, 750 mW/300 ohms) puts out ~2.5x more than the BHC into 300 ohms, but it sure doesn't sound like that.


----------



## DenverW

You guys are not accounting for the force.  The crack is strong with it.


----------



## cddc

bagwell359 said:


> But its NOT more powerful on paper.  My Rag 1 (100 wpc/4 ohms, 15 wpc/50 ohms, 750 mW/300 ohms) puts out ~2.5x more than the BHC into 300 ohms, but it sure doesn't sound like that.




I think that's typical for solid state amps, they usually put a large nominal output power on paper, but when you put them to work they may not output as much power as they put on paper. Oftentimes you'll find an 8W 300B amp sounds much more powerful than a 60W solid state amp. So I think we must discount the nominal output powers on SS amps.


----------



## bagwell359 (Jan 28, 2021)

cddc said:


> I think that's typical for solid state amps, they usually put a large nominal output power on paper, but when you put them to work they may not output as much power as they put on paper. Oftentimes you'll find an 8W 300B amp sounds much more powerful than a 60W solid state amp. So I think we must discount the nominal output powers on SS amps.



300B... haven't heard one in about 15 years, pretty much top of the mountain in tube-land


----------



## InstantSilence

Can it power an abyss TC?


----------



## bagwell359 (Jan 28, 2021)

DenverW said:


> You guys are not accounting for the force.  The crack is strong with it.



Yes, it's a revaltion.  It might even make some of those German cans I hate sound good.

It's even better/stronger with a E80CC as the driver.  


 Mine is actually an Amperex with gold pins. Have to change (or add and then a switch) resistor in the speedball board to get the most out of it, its got more output and its quiet, so quiet. It's about 1.5 inches taller than the standard tube.


----------



## DenverW

Looks like a pre1955 welded plate.  Amazing tube.


----------



## bagwell359

DenverW said:


> Looks like a pre1955 welded plate.  Amazing tube.



I'd say so.  There are two pics of my tube in the BHC thread probably in the Spring of ;20 if you are curious.


----------



## PsilocybinCube

bagwell359 said:


> Yes, it's a revaltion.  It might even make some of those German cans I hate sound good.
> 
> It's even better/stronger with a E80CC as the driver.   Mine is actually an Amperex with gold pins. Have to change (or add and then a switch) resistor in the speedball board to get the most out of it, its got more output and its quiet, so quiet. It's about 1.5 inches taller than the standard tube.



Tubes make the hd800 into the totl headphone.


----------



## A Jedi

InstantSilence said:


> Can it power an abyss TC?



No. Planars require a lot of current. OTL designs can do plenty of voltage but not much current.


----------



## DenverW

bagwell359 said:


> I'd say so.  There are two pics of my tube in the BHC thread probably in the Spring of ;20 if you are curious.



I've been trying to turn people on to the pre 1955 amperex welded plate slanted D getter.  For some reasons, its all melz and craziness instead .


----------



## Bonddam

Is anyone looking to try Bendix 6080 which I believe the Crack takes pm me if interested.


----------



## HiFiHawaii808

PsilocybinCube said:


> Tubes make the hd800 into the totl headphone.


The BHC makes my HD800S into great headphones.   But, you lose some transparency with tubes.     What really turned my HD800S into TOTL cans is equalization.   Hugo 2 + Equalizer APO + HD800S = TOTL for any genre of music.


----------



## carlman14

Alright everyone, I have the next big modification to my franken-crack ready. Meet the tube-rectified bottlehead crack! I completely re-implemented the power supply with an oversized power transformer capable of supporting a tube rectifier. The high-voltage winding is maida-regulated for a consistent, stable, low-ripple B+ voltage no matter what rectifier is plugged in. Any 5V rectifier is supported. I've tried 5U4G, 5U4GB, 5AR4, and 596 rectifiers with great success.

One neat thing here is that if I wanted to go back to SS rectification, I can! I have a SS plug-in rectifier that fits in the octal socket. This was tons of fun, and I learned a lot about power supply design in the process!

Under the hood you can see the maida regulator for the HV winding, as well as the massive heatsink attached to it. I managed to fit this while keeping all the previous upgrades in place, including the onboard DAC.

I also replaced the input wiring with shielded cable, as there were now AC lines closer to the input wiring. With the shielded wire in place, the amp is completely silent with no hum whatsoever from the new PT. It's silent using both the RCA inputs as well as using the onboard DAC.

Overall I am very pleased with how this turned out. The differences in sound are noticeable, and my BHC has never sounded this good! Aesthetically, it came out better than I expected too. I managed to fit the new transformer in such a way that it covered the massive hole in the top plate from the original transformer.


----------



## Bonddam

carlman14 said:


> Alright everyone, I have the next big modification to my franken-crack ready. Meet the tube-rectified bottlehead crack! I completely re-implemented the power supply with an oversized power transformer capable of supporting a tube rectifier. The high-voltage winding is maida-regulated for a consistent, stable, low-ripple B+ voltage no matter what rectifier is plugged in. Any 5V rectifier is supported. I've tried 5U4G, 5U4GB, 5AR4, and 596 rectifiers with great success.
> 
> One neat thing here is that if I wanted to go back to SS rectification, I can! I have a SS plug-in rectifier that fits in the octal socket. This was tons of fun, and I learned a lot about power supply design in the process!
> 
> ...


Only a crack user would be that crazy! That’s one crazy Crack.


----------



## HiFiHawaii808

carlman14 said:


> Alright everyone, I have the next big modification to my franken-crack ready. Meet the tube-rectified bottlehead crack! I completely re-implemented the power supply with an oversized power transformer capable of supporting a tube rectifier. The high-voltage winding is maida-regulated for a consistent, stable, low-ripple B+ voltage no matter what rectifier is plugged in. Any 5V rectifier is supported. I've tried 5U4G, 5U4GB, 5AR4, and 596 rectifiers with great success.
> 
> One neat thing here is that if I wanted to go back to SS rectification, I can! I have a SS plug-in rectifier that fits in the octal socket. This was tons of fun, and I learned a lot about power supply design in the process!
> 
> ...


What do all of those changes do to the sound?    It looks like it might be capable of time travel.


----------



## InstantSilence

Anyone have this amp with the Rosson Rad0?


----------



## JamieMcC

carlman14 said:


> One neat thing here is that if I wanted to go back to SS rectification, I can! I have a SS plug-in rectifier that fits in the octal socket.



Congratulations on the build the ss plug in idea is inspired


----------



## carlman14

HiFiHawaii808 said:


> What do all of those changes do to the sound? It looks like it might be capable of time travel.



The regulated PSU definitely made the biggest change out of all the upgrades (aside from the speedball). Early impressions are that the sound is just flat-out cleaner and more resolving, and the bass is more defined and punchier.



JamieMcC said:


> Congratulations on the build the ss plug in idea is inspired



Thanks! I like having ultimate flexibility of either tube or SS rectification.


----------



## carlman14

InstantSilence said:


> Anyone have this amp with the Rosson Rad0?



The impedance of the Rad0 is only 29 ohms, so this amp is a bad pairing. This amp is more suited for high impedance headphones like Sennheiser and ZMF (200-300 ohm or above headphones).


----------



## HiFiHawaii808 (Feb 1, 2021)

carlman14 said:


> The regulated PSU definitely made the biggest change out of all the upgrades (aside from the speedball). Early impressions are that the sound is just flat-out cleaner and more resolving, and the bass is more defined and punchier.


Can I achieve something similar just by purchasing a different amp?  That seems a lot of work and the aesthetic of it really does leave quite a bit to be desired.


----------



## InstantSilence

carlman14 said:


> The impedance of the Rad0 is only 29 ohms, so this amp is a bad pairing. This amp is more suited for high impedance headphones like Sennheiser and ZMF (200-300 ohm or above headphones).


When looking for an amp how do I match inpedence and all that ohms ect. 
I never quite understood electricity. 
Dumb it down for me as simple as possible. How do I match things up and read on paper and assume the pairing is OK or bad?


----------



## DenverW

HiFiHawaii808 said:


> Can I achieve something similar just by purchasing a different amp?  That seems a lot of work and the aesthetic of it really does leave quite a bit to be desired.



Sometimes it’s about the journey .


----------



## carlman14

HiFiHawaii808 said:


> Can I achieve something similar just by purchasing a different amp? That seems a lot of work and the aesthetic of it really does leave quite a bit to be desired.



It was a lot of work.  The main purpose of doing this was for the fun of tinkering and learning about amp design. The crack is all about tinkering... some just take it further than others. 

And personally, I love the aesthetic of adding the rectifier tube. It looks super unique as far as cracks go. It's not ugly... It has character lol.

You could accomplish something similar by just buying a crackatwoa instead of a crack. It has a lot of the common upgrades people do to the crack included already.



DenverW said:


> Sometimes it’s about the journey .



Exactly!


----------



## carlman14

InstantSilence said:


> When looking for an amp how do I match inpedence and all that ohms ect.
> I never quite understood electricity.
> Dumb it down for me as simple as possible. How do I match things up and read on paper and assume the pairing is OK or bad?



As far as I understand it, planar magnetic headphones need a lot of current to be driven properly, whereas high impedance dynamic headphones need more voltage. OTL designs like the bottlehead crack output sufficient voltage into high impedance headphones, but not nearly enough current for lower impedance panars.

For planars, look for either a solid state amp, or a OTC (output transformer coupled) tube amp with a relatively low output impedance (8 and 32 ohm outputs are common in OTC tube amps). Most planars will do well with either.


----------



## cddc

carlman14 said:


> Alright everyone, I have the next big modification to my franken-crack ready. Meet the tube-rectified bottlehead crack! I completely re-implemented the power supply with an oversized power transformer capable of supporting a tube rectifier. The high-voltage winding is maida-regulated for a consistent, stable, low-ripple B+ voltage no matter what rectifier is plugged in. Any 5V rectifier is supported. I've tried 5U4G, 5U4GB, 5AR4, and 596 rectifiers with great success.
> 
> One neat thing here is that if I wanted to go back to SS rectification, I can! I have a SS plug-in rectifier that fits in the octal socket. This was tons of fun, and I learned a lot about power supply design in the process!
> 
> ...




Wow...this Franken'd Crack is awesome, you are the man!

While I do prefer tubes to SS in the signal path, I've been trying to avoid tube rectification when considering amps (it's not in the signal path anyway). I heard SS rectification is superior to tube rectification, as there are voltage drop and voltage instability (up and down) with tube rectification.

So how is the tube rectification going? How does it compare to the SS rectification in your opinion, which one do you prefer?


----------



## cddc

InstantSilence said:


> When looking for an amp how do I match inpedence and all that ohms ect.
> I never quite understood electricity.
> Dumb it down for me as simple as possible. How do I match things up and read on paper and assume the pairing is OK or bad?



You should consider Mainline from Bottlehead, it works with both low-impedance headphones (like planars, Grado's,...) and high impedance headphones. Crack works best for high impedance headphones.


----------



## DenverW

cddc said:


> You should consider Mainline from Bottlehead, it works with both low-impedance headphones (like planars, Grado's,...) and high impedance headphones. Crack works best for high impedance headphones.



I have a mainline, and I often don’t love it with some planars I’ve tried, for example the he-500.  I’m in the process of getting a Bottlehead sex amp, and I’ll see how that pairs.


----------



## MattTCG

DenverW said:


> I have a mainline, and I often don’t love it with some planars I’ve tried, for example the he-500.  I’m in the process of getting a Bottlehead sex amp, and I’ll see how that pairs.



The SEX amp pairs well with planars. I believe that you will enjoy that combo. Best of luck!


----------



## carlman14

cddc said:


> Wow...this Franken'd Crack is awesome, you are the man!
> 
> While I do prefer tubes to SS in the signal path, I've been trying to avoid tube rectification when considering amps (it's not in the signal path anyway). I heard SS rectification is superior to tube rectification, as there are voltage drop and voltage instability (up and down) with tube rectification.
> 
> So how is the tube rectification going? How does it compare to the SS rectification in your opinion, which one do you prefer?



Thanks! Voltage drop, instability, and heat are definitely disadvantages of tube rectifiers. I mitigated the voltage drop and instability by using a regulated power supply. So no matter what rectifier is plugged in, I get the same output voltage. No need to worry about voltage drop. 

Realistically, there's no benefit big enough to use tube rectification over SS. The only thing I can think of is that some tubes have a slow start up (like the 5AR4), which gives the input/output tubes time to warm up before being hit with B+ voltage. This is better for tube health and will lengthen the life of the tubes in the signal path. Also, I'm not sure if this is the particular SS plug-in rectifier I'm using... but I get a lower noise floor with tube rectifiers than SS. Sound-wise, to me rectifiers make almost no difference in sound. If there's any differences between tube and SS, they're either very minute or I'm just imagining them. The improvements I described earlier are likely the result of the revamped power supply rather than the actual rectifier used.

But like I said... using a tube instead of SS was 100% for fun/looks and not for sound improvements


----------



## cddc

carlman14 said:


> Thanks! Voltage drop, instability, and heat are definitely disadvantages of tube rectifiers. I mitigated the voltage drop and instability by using a regulated power supply. So no matter what rectifier is plugged in, I get the same output voltage. No need to worry about voltage drop.
> 
> Realistically, there's no benefit big enough to use tube rectification over SS. The only thing I can think of is that some tubes have a slow start up (like the 5AR4), which gives the input/output tubes time to warm up before being hit with B+ voltage. This is better for tube health and will lengthen the life of the tubes in the signal path. Also, I'm not sure if this is the particular SS plug-in rectifier I'm using... but I get a lower noise floor with tube rectifiers than SS. Sound-wise, to me rectifiers make almost no difference in sound. If there's any differences between tube and SS, they're either very minute or I'm just imagining them. The improvements I described earlier are likely the result of the revamped power supply rather than the actual rectifier used.
> 
> But like I said... using a tube instead of SS was 100% for fun/looks and not for sound improvements



Fantastic, thanks a lot for letting us know the difference between tube rectification and SS rectification on Crack! No one has done that before!

You are correct, the slow start-up with tube rectification does help improve the working conditions for tubes and lengthen their lives. With SS rectification B+ hits tubes almost right away after amp is turned on, while tube rectifiers need some time to boil electrons off the cathodes.

I guess the maida regulator that you implemented plays a pivot role in getting a solid power supply for your Franken Crack, so that it minimizes the impact from different rectifier tubes or SS. The gigantic heatsink on the regulator also looks awesome btw, really love it! So you ditched the CRCRC filter in Crack PSU all at once, or you added the maida regulator after the CRCRC filter in case you still use the SS rectification?


----------



## carlman14

cddc said:


> Fantastic, thanks a lot for letting us know the difference between tube rectification and SS rectification on Crack! No one has done that before!
> 
> You are correct, the slow start-up with tube rectification does help improve the working conditions for tubes and lengthen their lives. With SS rectification B+ hits tubes almost right away after amp is turned on, while tube rectifiers need some time to boil electrons off the cathodes.
> 
> I guess the maida regulator that you implemented plays a pivot role in getting a solid power supply for your Franken Crack, so that it minimizes the impact from different rectifier tubes or SS. The gigantic heatsink on the regulator also looks awesome btw, really love it! So you ditched the CRCRC filter in Crack PSU all at once, or you added the maida regulator after the CRCRC filter in case you still use the SS rectification?



So I went home and re-listened to tube vs SS rectifiers, and I half-take back what I said earlier. Take this with a grain of salt... but It sounds like the SS rectifier could have slightly faster, leaner bass, whereas the tube rectifier has a little bit fuller bass. The tube seemed to have a tiny bit more treble extension too. These differences are so minuscule that there's a chance I'm imagining it. So basically, what I said holds true. You're not missing anything with either type of rectifier. 

To answer your question, I completely tore out the CRCRC (CLCRC in my case) in favor of the regulator. The order of PSU components now is PT -> rectifier -> 33uF input cap -> regulator -> output voltage. The regulator has insane DC filtering on it's own (about 20uV of ripple), which is way better than I would have gotten with the CLCRC filter. I am able to still use SS rectification because I have a plug-in SS rectifier that plugs into the octal socket where a tube rectifier would go. I attached a pic of the SS rectifier I'm using.


----------



## cddc (Feb 1, 2021)

Awesome, coming up with the idea of optimizing the PSU with an HV regulator is creative!


----------



## evonimos

I think, if one chooses to go with tube rectification then it's kind of 'counterproductive' to also apply an IC-based regulator in its path.
It sort of defeats the purpose of choosing to forgo with the sand based rectification in the first place. Especially when you place an IC down the line.

That's just me but hey, it is all about fun and that's why we do stuff.


----------



## carlman14

evonimos said:


> I think, if one chooses to go with tube rectification then it's kind of 'counterproductive' to also apply an IC-based regulator in its path.
> It sort of defeats the purpose of choosing to forgo with the sand based rectification in the first place. Especially when you place an IC down the line.
> 
> That's just me but hey, it is all about fun and that's why we do stuff.



That's a great point. I was actually wondering about this myself when I was building this. I already had these parts on-hand, so I ran with it! I think I found a way to fit a couple chokes under the hood to try out a more traditional tube rectifier setup. And because this is the frankiest franken-crack, I think I just might try it!


----------



## larcenasb (Oct 20, 2022)

*Bottlehead Crack Upgrading Guide*

EDITED 2/4/2021 4:26 PM: grammatical edits, restructured some parts, added bits of info, and added links for my Bottlehead headphone amps comparison review & 6SN7GT comparison review

Introduction

It's been a little while for me reading or posting in this thread, but I’ve gotten a couple of messages last week about what mods most improve the sound quality of the Crack. So, I’ll post my take on the subject here in case anyone else is wondering. The mods will be ranked in tiers 4-1: tier 4 being the top and with the most obvious audible improvement, and tier 1 being no noticeable audible improvement, or merely audio gear jewelry. Within each tier, the mods are further listed in order of most audible improvement...except tiers 2 and 1 because no audible improvement was discerned by me. Included are only the more popular--and reasonably affordable--mods that you’ll see on many, many builds (for example, my suggestions will favor things like a $30 stepped volume attenuator, not an exotic $200 attenuator). This is by no means comprehensive; look at this as more of _a table of contents to guide you_ on your exploration through this and Bottlehead's forums. If you're interested in a particular upgrade listed, Google it, along with keywords: "bottlehead" and "crack" to direct you to detailed forum posts and guides. And of course, feel free to reply/ask here if you can't find the info you need and I, or many of the other bottlehead tinkerers, will surely try to help.

Here for reference are some photos of my most recent build at various stages:










These rankings are of course just my humble opinion and with my gear (see my sig below)! However, I have built 3 Cracks since 2010, installed upgrades one at a time over the course of months, and have done a sit-down listening comparison with the Crack, Crackatwoa, SEX, and Mainline at Bottleheadquarters [review can be found here: https://www.head-fi.org/threads/bot...ck-sex-mainline.683012/page-131#post-15398582]. So, I think I have a decent level of experience to reference when it comes to differences in sound with Bottlehead gear.

Lastly, since the list will be ranked in order of most audible improvement, price isn't factored in. So, I will use asterisks in front of the upgrades that I think represent amazing value for what you get. Let's go!

Tier 4: Obvious audible improvements

Add Speedball upgrade (_dramatically_ _increased clarity, separation, excitement, dynamics, bass slam..._) [$115]
*Replace stock 6080 w/ 6AS7G (_in general... wider soundstage, a fuller sound, more natural tone, deeper bass..._) [$20-ish]
Changing the output tube (6080/6AS7) has a bigger effect on the overall sound compared to the input tube (12AU7/6SN7), though the input tube has many more options for tuning the signature to your precise liking.

Replace stock 12AU7 w/ 6SN7GT, using a 6SN7-to-12AU7 6.3V adapter (_in general... full-bodied vocals, more balanced across frequency range, more natural tone...and just better overall for what I consider to be lifelike sound_) [a good-testing old-stock 6SN7GT can be had for around $20-30 on auction sites, $20-ish for the adapter]
Some history: _"The main competitor of the 6SN7GT after the war was the 12AU7 and its variants. A dual version of the 6C4 triode, the 12AU7 was developed by RCA in late 1946. It used half as much heater current and had a smaller footprint than the 6SN7GT. RCA and GE (having bought Ken-Rad in 1945) heavily pushed miniature tubes after the war, and many miniatures were designed-in where octals or loctals would have been the natural choice. The higher cathode emission and plate dissipation of the 6SN7GT kept it popular, though...In 1954, RCA came out with the 6CG7, which was pitched as a direct equivalent of the 6SN7GT. Although audiophiles found that the 6SN7GT typically sounded better, this was the beginning of the end for widespread usage of the 6SN7GT." _[source: https://www.effectrode.com/knowledge-base/the-6sn7gt-the-best-general-purpose-dual-triode/]
You could also use a 6F8G w/ a 6F8G-to-12AU7 6.3V adapter. It's the older brother of the 6SN7GT and sounds just as good, if not minimally better. But availability and price make the 6SN7GT a more viable option for most people. Also the 6SN7GT tends to be less noisy and microphonic IME...but I still love my 6F8G tubes. [My comparison review of some of the more popular NOS choices can be found here: https://www.head-fi.org/threads/6sn7gt-6f8g-an-exploration-of-wwii-era-octal-tubes.890205/]

Volume pot upgrade (pick one):
*Pad stock pot w/ 75K & 33K Ohm resistors for -12dB of attenuation (_no more channel imbalance at low volumes, more usable volume range and control_) [$5-ish]
Only pad the volume pot if the volume gets too loud too quickly w/ your headphones. I find it does even w/ my power-hungry AKG K240 Sextetts 600 Ohm...

*Replace stock pot w/ 100K stereo stepped attenuator (_perfect channel balance at all levels, and, as a bonus, subtly increased clarity and separation_) [$20-30 on auction sites]
No need to pad a stepped attenuator...is already just a series of resistors and provides good usable volume range adjustment.
I use a Valab 23-step but it doesn't seem to be available on auction sites anymore. Dale 23-step is another option around $20-30 that other Crack owners have used w/ success.
You may be wondering why I'm not suggesting an upgraded potentiometer like the popular Alps 100KAX2... I've used it in the Crack but, IMO, a stepped attenuator is better for the money: channel imbalance isn't a concern, you get more usable volume range (not restricted to the 7-9 o'clock positions). With the Alps you really should get a PCB and not solder wires directly to those fragile pins, you may have to cut/dremel the shaft if it's too high, and you will likely still need to pad it with resistors...I'd just rather get a stepped attenuator and enjoy the easier install and better sound. But if you like the smooth feel of a volume pot over the clicky turns of an attenuator, or if you like that the pot allows you to really fine-tune the volume instead of being limited to 23 set volume levels, then go for it.
Also, I've used an Audio Note 100K stereo volume pot [$35-ish] in one of my Crack builds and I was very impressed with the build quality, smooth feel of the turns, good tracking, and that it had solder lugs for easy installation. Though it would still need to be padded to get more usable volume range. It's my pick if you prefer a pot over an attenuator. And, again, there's nothing wrong with an Alps if you don't mind how it's high maintenance...You are a tinkerer after all, right!?


Tier 3: Subtle but clearly noticeable

Replace electrolytic output caps w/ film caps (_smoother treble and midrange_) [anywhere from $50-100 and beyond]
Don't stress so much on which brand to get or how much to spend...the important thing is to have film caps, in general, handling the audio signal. Any respectable brand will do just fine. Having said that... Dayton 250V, Audyn Q4 400V, and Panasonic EZPE 500V are good value options around $50 for 2.
Here's a chart from the Bottlehead forums that I saved years ago. It shows bass roll-off of different output cap capacitance values depending on your headphones' impedance. So, with my AKG K240 Sextetts 600 Ohms, I could use 33uF output caps and notice no bass roll-off vs the stock 100uF caps...however, it's nice to have a little breathing room in case I want to plug in different headphones.



With the above chart in mind... I actually use 68uF output caps (Audyn Q4 68uF 400V). There are multiple reasons for this: 1) Due to the Crack's 120 Ohm output impedance, it's not recommended to use headphones lower than 200 Ohms regardless of what output capacitance is used for the output caps [search "Crack damping factor" to learn more]...it basically just means the Crack doesn't control the drivers of low-impedance cans well because it was designed for high-impedance cans, 2) The lower-value cap is also used as my last power supply cap, so the lower capacitance means more savings for those nicer bypass caps, 3) Higher voltage caps, like my 400V Audyns, are physically bigger and the 100uF version wouldn't fit with the way I'm mounting them.

*Replace first 270 Ohm resistor (the one on the left terminal strip of the power supply) w/ Triad C-7X choke (_better dynamics, separation, bass definition, quieter background..._) [$12-ish]
Add a higher-quality 1/100 film cap as a bypass on the last power supply film cap (replacing last power supply electrolytic cap first w/ one identical to the output film caps is advisable since lower-capacitance bypass caps are cheaper, see tier 2) (_adjusts the sound signature to your liking w/ an influence from the qualities of the nicer cap_) [from $20 on upwards]
Bottlehead designer, Paul Joppa has said, _"There are no reliable 'rules' about bypassing power supply caps. Sometimes they help, sometimes they hinder, and sometimes you can't tell the difference. The '1% rule' is really more like 'something between 0.1% and 10%' and even then exceptions are not at all uncommon...The only reliably useful answer is 'try it and see!'" _[source: Bottlehead forum, Re: Power supply bypass cap values, Reply #15, May 22, 2013, 08:20:51 PM]
So, for my 68uF last PS cap, I would prefer a 0.68uF bypass, but wouldn't fret at all if the cap I wanted to try was only available in 0.47uF or 1uF. Even .068uF or 6.8uF, as Mr. Joppa explained, are worth a try.
I've tried the following 0.68uF caps: Jantzen Superior-Z [$15], Audyn Tri-Reference [$25], and Audyn True Copper [$50]. The Jantzen sounded detailed and natural, but it was subtle. The Audyn Tri-Reference had a bold sound in comparison, with natural tone and thrilling dynamics. Switching to the Audyn True Copper didn't live up to what I imagined it would be after months of dreaming of it (yeah, I'm a nerd lol)...the True Copper sounded very refined but lacked the boldness and dynamics of the Tri, sounding very polite...and my tastes just couldn't live with that. More expensive doesn't always mean better for what you prefer. And though I love my Audyn Tri-Reference, its thick copper leads were a pain to deal with...
Many swear by bypassing PS caps, but loathe the idea of bypassing or "contaminating" output/signal caps. Try if you like and discover what you think is best. I personally haven't bypassed the output caps, but with Mr. Joppa's comment below (tier 2, 1st bullet point) about the last power supply cap being in the audio current loop, and being_ "as important as the output coupling cap," _then theoretically my bypassing the last PS cap isn't much different--from a purist's perspective--than bypassing the output caps! I love the sound from the Audyn Tri-Reference bypass though, so I don't care about being a purist in this sense.

Add sound deadening material (Dynamat, Kilmat, Noico, MAT66, etc.) to underside of top-plate (_reduces microphonics when turning on amp, adjusting volume, tapping top plate if you ever do that lol, etc._ _...just improves the user experience and adds a dense, quality feel to your amp_) [<$20]
You don't need full coverage... Like with sound-deadening car doors, follow the 25% rule to avoid diminishing returns. I apply larger pieces where I can and focus on putting smaller pieces all around the tube sockets, volume pot/attenuator, and the headphone socket. See second-to-last photo at top of post.

Tier 2: I’d like to think I hear a difference, but it’s more placebo than anything

Replace last power supply cap (C3, the sideways one) w/ film cap (ideally, double the capacitance of the output caps [100uF output caps, 220uF last PS cap]...but the same value [100uF output caps, 100uF last PS cap] is commonly used due to space constraints) [$20-30 for Dayton, Audyn, or Panasonic]
Paul Joppa has said, _"The output audio current flows through the power supply, mostly the last capacitor, as well as through the output coupling cap and the output triode. So the final power supply cap should, in theory, be as important as the output coupling cap with regard to the sound of the amp." _[source: Bottlehead forum, Re: Upgrading the power supply capacitors in the Crack, Reply #4, April 18, 2011, 08:08:44 AM]
It was hard for me to notice, but then bypassing it w/ a higher-quality cap was clearly noticeable. So, this is an important upgrade to me as a gateway to bypassing it. On its own though, I can't say I can tell the difference for sure.
If on a budget, you could install the last PS film cap before installing the output film caps...maybe then the difference would be more noticeable...and it would be half the cost. I know it seems like common sense to take care of the output/signal caps first, but here's a situation where an audio engineer, Mr. Joppa, is telling us the theory of the circuit design...an engineer's theory should take precedence over a layman's common sense. So, if you install this instead of the film output caps, it could potentially be a tier 3 upgrade...it's just not my experience, so I can't place it there.

Replace the 220uF 250V first power supply cap (C1, beside RCA jacks) w/ 470uF 250V electrolytic cap (more power supply filtration) [$5-ish for Nichicon KX, which are "great for power supply upgrades," according to hificollective...I went with Nippon Chemi-Con KMH]
Bottlehead designer, Paul Birkeland, has said,  _"...there's nothing wrong with increasing the capacitance of cap 1 or 2 in the power supply (I put a 500uF cap for C1 in one Crack I built)_._"_ [source: Bottlehead forum, Re: Choking the Crack, Reply #12, November 10, 2012, 04:15:11 PM]
This is something I do since I'm not using the ideal doubled-capacitance last power supply film cap...I use the same capacitance for the PS film cap as the output caps. So, with the larger capacitance PS electrolytic, it's nice to know I'm not lacking in PS filtration.
Actually, as you can see in my above photos, I replaced both PS electrolytics w/ 470uF caps, but it's clearly overkill... for my next build, I would just upgrade the first PS cap and return to the land of reason.

Add 1/100 film bypass cap to each electrolytic power supply cap (C1 & C2) [<$5 for 2.2uF or 4.7uF 250V film caps]
For power supply electrolytics, basic film caps are all you need (orange drop, Dayton, Audyn Q4, Wima, etc.). Caps w/ beeswax and, as Audyn calls it, "fairy-like oils" don't make much sense in this application, or arguably in any audio application for that matter.
I went with ClarityCap PX 4.7uF 250V caps. They fit very nicely as you can see, but the thicker leads were less than ideal to work with. I'd go with orange drop types next time.

Replace power supply rectifiers (18, 19, 20, & 21) w/ Cree Schottky diodes [$5-ish for 4 "CSD01060A" diodes & "Discrete Bridge Rectifier PCB - TYPE 2 (TO-220 Radial Style)" PCB]
Many say there's increased detail, dynamics, and clarity, but I didn't notice...maybe if I didn't already install the choke, I might've noticed?...
For only $5, perhaps try this before the choke and report back here if you notice any audible improvements. I'll do this for my next build. This is another upgrade that has the potential to be a tier 3 upgrade if installed instead of the choke or other PS upgrades.

Replace input wires (from RCA jacks to volume pot) w/ Mogami W2549 cable, or other OFC cable/wires [$0.80/ft. for Mogami W2549, $0.50/ft. for Canare L-2T2S, and you only need about 1 ft.]
Some say the sound in the Crack is smoother w/ OFC...I would love to see them identify it in a blind test.
But this is something I will always do anyway since I have so much OFC wire/cable lying around...it's one of those "nice to haves" that don't cost much at all. For less than $1, it's comforting to know your audio signal is comfortably traveling in style!

Tier 1: Audio Gear Jewelry

Replace plastic volume knob w/ solid aluminum knob [$5-ish]
Of course, has no effect on sound quality, but the weighty feel turning the knob is really nice/premium.
Especially if using a pot, a larger diameter knob allows you to really fine-tune the volume--similar to what joystick extenders do on game controllers. Up to 50mm diameter knobs will fit, even if using the wider 6SN7GT tube.

Replace RCA jacks w/ exotic noble-metal-plated jacks [up to $20 or more]
Bottlehead upgraded their RCA jacks since 2010, the gold-plated jacks they supply now are already of great quality...I feel no need to "upgrade" them.

Replace tube sockets w/ gold-plated ceramic tube sockets [$5 or more]
This is another thing I always do anyway because I like to show my NOS tubes that I appreciate them lol...another "nice to have".

Replace rubber feet w/ metal spikes [$15 or more]
Taller variants of course can supply more ventilation...but are mostly just pretty.

My Recommendations

If you have a basic Crack built, and objective sound quality improvement is what you're after, just work down tiers 4 & 3.
If you have a basic Crack built, and objective sound quality improvement is what you're after...but money is a concern, I would buy upgrades in stages every few months or so (but perhaps still install each part one at a time to try and hear the differences):
STAGE 1 $25: 6AS7G, and pad stock volume pot
STAGE 2 $50: 6SN7GT + adapter, and choke
STAGE 3 $100: Speedball kit
STAGE 4 $100: stepped attenuator, film output caps, and sound deadening material

If you have a basic Crack built, and you're a starving student who gives up Cup Noodles in order to get good audio, buy one upgrade at a time!  I'd focus first on padding the volume pot, then trying to get a good deal on tubes on auction sites, and then trying some of the low-cost power supply upgrades like the 470uF first PS cap, Cree Schottky diodes, or bypassing the PS electrolytics. And ask for the Speedball kit for your birthday...
If I were starting a new Crack build, here's how I'd go about it: basic Crack kit, gold-plated ceramic tube sockets, Mogami W2549 input cable, stepped attenuator, sound deadening material, and solid aluminum volume knob.
This would run you about $360. The reasoning for these upgrades is that they don't cost too terribly much and some are easier to install right from the get-go (good luck if you decide to replace the stock tube sockets later on...). Also, these initial upgrades make the basic kit feel much more premium and make for a good foundation to install the more expensive upgrades down the road--think of it like prioritizing a good-quality motherboard for a new PC. For me, sound quality is most important...but it's also nice to have a really premium looking and feeling product.
For the sound deadening material, be sure to plan the layout: leave open spaces for future upgrades such as the zip-tie mounts for the output caps, and standoffs for the choke.

If cost is no object and you want the best sound this circuit has to offer ASAP, then consider getting the Crackatwoa kit instead. In stock form, it's better than the Crack w/ all the above upgrades...and would actually be cheaper overall (don't forget separate tax and shipping for all the Crack upgrades). [$269 premium for the Crackatwoa over the Crack + Speedball]
For upgrading the Crackatwoa, Bottlehead owner, Doc B., explained to me that all the PS upgrades for the Crack--including replacing the last PS cap with a film cap--would be pointless, as the more sophisticated, shunt voltage regulated power supply is a far better solution than all the Crack PS upgrades combined...I'm paraphrasing but I think that's accurate to what he intended. He can correct me here if I'm wrong. 
For the Crackatwoa, the only upgrades I would do are: 6AS7G, 6SN7GT + adapter, stepped attenuator, film output caps, gold-plated ceramic tube sockets, sound deadening material, and solid aluminum volume knobs. [around $150]

Conclusion

This turned out to be longer than I expected haha, but I wanted to add details and notes that I think are important to clarify for anyone starting their Crack journey. This amp is certainly a mainstay--being available for over a decade--and, as you can see, there are many upgrade paths you could go down, but hopefully my post here is a good primer and starting guide if you're planning your first build or first upgrades to an existing build. It should help you to not go overboard and to get the most for your money. Like I said in the intro though, this isn't comprehensive and you should always seek other forum members' inputs, so as to not take one person's word as the end-all-be-all. Good luck with your build!


----------



## evonimos (Feb 3, 2021)

Regarding tubes and mods that go well with them, I'd ike to add my two cents.
I know this is probably a contentious issue, but my compulsive A/B tests seem to indicate that tubes do very well with carbon composite resistors.

The difference (or improvement in my opinion) is not that huge, but it is there.
They seem to add further to the 'tubiness' of  the sound.
By 'tubiness', I mean the subjective effect that comes along with tubes, especially in zero-feedback, single ended topologies.
It certainly doesn't hurt trying them out, despite the 'bad press' they've been getting from people compared to other types like metal-film resistors etc. The only issue is that they are getting harder to come by (and cost accordingly) and the current production is limited to 250mW and 500mW power ratings only.

Larger wattage carbon films are also a good match, especially when you need something above the 500mW mark.

If I had to make a guess of what's going on, I'd say they might add slightly more second order harmonics which seems to be the reason tubes can sound so unique.
But that is just me speculating so it might be something else entirely.


----------



## HiFiHawaii808 (Feb 3, 2021)

larcenasb said:


> *Bottlehead Crack Upgrading Guide*
> 
> Introduction
> 
> ...


Very nice.   One of the best overviews and upgrade how-to guides I've every seen for the Crack.

All you need is the same type of analysis for Tubes and you've got one of the best how-to guides in the industry.


----------



## DeweyCH

larcenasb said:


> *Bottlehead Crack Upgrading Guide*
> 
> Introduction
> 
> ...


Wow, this is super helpful. I'm planning my first build and will follow as much of this as I can - I already have a stepped attenuator I was considering putting in my Darkvoice, but that's got an Alps and a shunt mod so I'm pretty happy with it... and I'll probably use the fancier tube sockets I ordered for the DV here, since I am not really looking forward to trying to replace the sockets in an already-built box.

Thanks!


----------



## larcenasb

HiFiHawaii808 said:


> Very nice.   One of the best overviews and upgrade how-to guides I've every seen for the Crack.
> 
> All you need is the same type of analysis for Tubes and you've got one of the best how-to guides in the industry.


Thanks so much for your kind words. And I actually do have a write-up for input tubes(!), you can read it here: 

https://www.head-fi.org/threads/6sn7gt-6f8g-an-exploration-of-wwii-era-octal-tubes.890205/

I'll also add the link to my post above under the 6SN7GT entry.


DeweyCH said:


> Wow, this is super helpful. I'm planning my first build and will follow as much of this as I can - I already have a stepped attenuator I was considering putting in my Darkvoice, but that's got an Alps and a shunt mod so I'm pretty happy with it... and I'll probably use the fancier tube sockets I ordered for the DV here, since I am not really looking forward to trying to replace the sockets in an already-built box.
> 
> Thanks!


You're welcome! I'm glad I wrote it at just the right time for you.  Yeah, replacing tube sockets is not a quick-and-easy task...best to do it at the start instead. I'd love to see photos of your build here once you're done! Cheers!


----------



## cddc

larcenasb said:


> *Bottlehead Crack Upgrading Guide*
> 
> Introduction
> 
> ...




Excellent write-up, easily one of the best in the Crack thread!

I was thinking why you need to pad the stock 100K pot with some resistor, while skipping it on the same 100K stepped attenuator? Is it because the 100K stepped attenuator is on logarithmic scale and the stock pot is on linear scale?


----------



## cddc

evonimos said:


> Regarding tubes and mods that go well with them, I'd ike to add my two cents.
> I know this is probably a contentious issue, but my compulsive A/B tests seem to indicate that tubes do very well with carbon composite resistors.
> 
> The difference (or improvement in my opinion) is not that huge, but it is there.
> ...




Interesting finding!

I guess you'll have to find some new production carbon composite resistors, as carbon composite resistors are notorious for drifting. The ones recycled from antique radios normally drifted miles away.


----------



## larcenasb

cddc said:


> Excellent write-up, easily one of the best in the Crack thread!
> 
> I was thinking why you need to pad the stock 100K pot with some resistor, while skipping it on the same 100K stepped attenuator? Is it because the 100K stepped attenuator is on logarithmic scale and the stock pot is on linear scale?


Thanks! And about not padding the attenuator... The Alps pot I had (100KAX2) was logarithmic but still needed to be padded. So, I don't know but I'd love to see a reply on this from some of the more technical head-fiers here. Anyone?


----------



## evonimos (Feb 4, 2021)

cddc said:


> I guess you'll have to find some new production carbon composite resistors, as carbon composite resistors are notorious for drifting. The ones recycled from antique radios normally drifted miles away.



I only use current production.
Usually by Ohmite (USA) or Kamaya (Japan), depending on availability.
They are both excellent, but cost 2-3 times more than film types.

Vintage stuff like Allen Bradley are way too much money and trouble for my projects at the moment.

However, the current production ones are getting increasingly harder to come by.
Also, all current production is limited to 250mW or 500mW power ratings and 10% or 5% accuracy.
Strangely this seems to be shared among all the manufacturers left making them.


----------



## Jimmyblues1959

Beefy said:


> I finally got around to uploading some photos of my Crack......
> 
> External:
> 
> ...



Nice clean build.  One of the nicest finished Bottlehead Cracks I have seen. 😊


----------



## Bruc3

Hi all,
After many Years of wanting one of these and never getting around to actually buying one, a friend may be selling his to me with stock tubes.

I plan to get the TS5998 as power tube, but what is a good/recommended driver tube?

I like nice vocals/mids.


----------



## DenverW (Feb 7, 2021)

DenverW said:


> So, I am going to entitle this post:  The Frustration with the Crackatwoa.
> 
> Having built and modded a crack and speedball.  I've really been excited to get my hands on a crackatwoa kit.  Black friday sale was just the ticket, and I've been taking my time (cause I have no time) to get to the build.  Worked the base...stained...lacquer...looks pretty good for my usually screw ups.
> 
> ...



Editing this post:  The rectifiers that I thought were missing were packed in with the c4s board, so it was my fault for assuming the packaging for the c4s didn't have additional parts.  Maybe not the place I would have packed them, but its a good learning experience to look in every plastic bag, even if one is clearly for a specific part of the build.


----------



## markkr

My crackatwoa build was difficult to say the least, first the skill level is about 10 notches higher than a regular Crack... I was missing 4 screws... and ran out of wire due to my attempt at “clean wiring”. Also the 7 pin sockets are very loose, the tubes are essentially “rattling” in the looseness of the socket. I had a bad wire which required disgnosis as well as a mistake that I made in the regular potentiometer.

Tonight I wired up the two-quiet... that was quite a chore but I cant test it yet since I’m awaiting 2 new 7 pin tube sockets. 

None of this is BH’s fault, 4 missing screws is no big deal... DIY always has challenges. Prior to the two-quiet, the amp sounded fantastic so I expect even better things with the upgrade. I also installed a pair of Mundorf caps for good measure.


----------



## DenverW

markkr said:


> My crackatwoa build was difficult to say the least, first the skill level is about 10 notches higher than a regular Crack... I was missing 4 screws... and ran out of wire due to my attempt at “clean wiring”. Also the 7 pin sockets are very loose, the tubes are essentially “rattling” in the looseness of the socket. I had a bad wire which required disgnosis as well as a mistake that I made in the regular potentiometer.
> 
> Tonight I wired up the two-quiet... that was quite a chore but I cant test it yet since I’m awaiting 2 new 7 pin tube sockets.
> 
> None of this is BH’s fault, 4 missing screws is no big deal... DIY always has challenges. Prior to the two-quiet, the amp sounded fantastic so I expect even better things with the upgrade. I also installed a pair of Mundorf caps for good measure.



Let me know what you think of the mundorf caps; I assume you're replacing the 100uf?  I'm considering those, but I've heard they're a bit warm, so I'm also looking at some clarity cap CSA that are on sale.  

I love BH, and nothing that's happened will stop my love for them, but I do get frustrated when I want to work on the amp with limited time and end up having to stop for delays from missing or faulty parts.  The screws werent a big deal for me either, I got some the next day at Home Depot, but waiting on a fuse took a couple days, and now I'm waiting on the missing rectifiers.  I'm super slow, so these delays just make things take longer and longer.


----------



## cddc

Bruc3 said:


> Hi all,
> After many Years of wanting one of these and never getting around to actually buying one, a friend may be selling his to me with stock tubes.
> 
> I plan to get the TS5998 as power tube, but what is a good/recommended driver tube?
> ...


 

Get the Mullard and Amperex, but don't go for Telefunken, Telefunken is clean & clear sounding, but kind of lean to my taste.


----------



## cddc (Feb 7, 2021)

DenverW said:


> Let me know what you think of the mundorf caps; I assume you're replacing the 100uf?  I'm considering those, but I've heard they're a bit warm, so I'm also looking at some clarity cap CSA that are on sale.
> 
> I love BH, and nothing that's happened will stop my love for them, but I do get frustrated when I want to work on the amp with limited time and end up having to stop for delays from missing or faulty parts.  The screws werent a big deal for me either, I got some the next day at Home Depot, but waiting on a fuse took a couple days, and now I'm waiting on the missing rectifiers.  I'm super slow, so these delays just make things take longer and longer.




Too bad, sorry to hear so many troubles. I guess probably it's a good idea to check parts on the checklist upon arrival, that way even there are missings a 2nd shipment should solve it all, but then at that time people probably don't know what these parts are for.

BH was probably in a rush to get those kits out after the Black Friday, haha. Hopefully they will send you the missings asap.


----------



## markkr (Feb 7, 2021)

DenverW said:


> Let me know what you think of the mundorf caps; I assume you're replacing the 100uf?  I'm considering those, but I've heard they're a bit warm, so I'm also looking at some clarity cap CSA that are on sale.
> 
> I love BH, and nothing that's happened will stop my love for them, but I do get frustrated when I want to work on the amp with limited time and end up having to stop for delays from missing or faulty parts.  The screws werent a big deal for me either, I got some the next day at Home Depot, but waiting on a fuse took a couple days, and now I'm waiting on the missing rectifiers.  I'm super slow, so these delays just make things take longer and longer.



I added both the 100uf and the .1uf caps to the low current board. The caps did add slight bit of warmth, however I think the increased clarity added by the Two-Quiet made up for it. It certainly sounds cleaner, more articulate than any Crack I've ever heard.


----------



## DeweyCH

My Crack with Speedball is shipping! Hopefully I can finish rebuilding my Darkvoice before it arrives... so at least I have something to listen to.


----------



## Bruc3

I got a pre-made Crack + speedball coming my way soon, should be hear next week. Looking forward to it.

Will be comparing it to my CMA12 and Figaro 339.


----------



## DenverW

DeweyCH said:


> My Crack with Speedball is shipping! Hopefully I can finish rebuilding my Darkvoice before it arrives... so at least I have something to listen to.



I had a darkvoice while my crack was broken for a couple months before repair.  Great amp, that darkvoice!  Once I got the crack going again, though, I had to say goodbye to it.


----------



## HiFiHawaii808

markkr said:


> I added both the 100uf and the .1uf caps to the low current board. The caps did add slight bit of warmth, however I think the increased clarity added by the Two-Quiet made up for it. It certainly sounds cleaner, more articulate than any Crack I've ever heard.


I have Munsdorf Evo Oil caps as well.   They really add a lot of clarity and sound stage.  I love them.


----------



## Bruc3

Who has paired both the Bendix 6080 and Tung Sol 5998 with their Crack?

Which did you prefer and why?

I have a Bendix 6080 incoming, and also considering to get a 5998 pair eventually.


----------



## haasaaroni

Bruc3 said:


> I got a pre-made Crack + speedball coming my way soon, should be hear next week. Looking forward to it.
> 
> Will be comparing it to my CMA12 and Figaro 339.


Let us know! The LF339 and Crack (and Crackatwoa) were my top picks for an OTL amp to try out with the ZMF Aeolus, as you know from the other thread... On @DenverW 's (and others') recommendation actually, I ordered a Crack kit to build myself. Along with a solder and all the gear  Looking forward to the whole process!


----------



## lalawilson168

Proud crack and SB owner here, wanna ask wheres the best place to get your hands on some munsdorf caps and which one I should be buying for the crack?

Also if any crackatwoa owners here and shed some light on whether it's a noticeable upgrade from the crack plus sb? I find very little review and impressions of the crackatwoa hence the ask . Cheers


----------



## maxpudding

lalawilson168 said:


> Proud crack and SB owner here, wanna ask wheres the best place to get your hands on some munsdorf caps and which one I should be buying for the crack?
> 
> Also if any crackatwoa owners here and shed some light on whether it's a noticeable upgrade from the crack plus sb? I find very little review and impressions of the crackatwoa hence the ask . Cheers



I own the C2A, never had a Crack (no pun intended) but from what I can tell you that the crackatwoa has the shunt regulator tubes, which means that the amp has a better channel separation. And of course, a larger chassis. Other members who had a Crack experience might have better answers than mine.


----------



## carlman14

My BHC has been in open heart surgery for the last couple weeks. I did a comparison between using the regulator from my last post and a more traditional CRCLC power supply. I decided to stick with the CRCLC for a few reasons:

1. The sound differences between the two PSU implementations were very minor (if any)... minor enough to justfiy not using the regulator. I can save the regulator for another project now.
2. CRCLC is running a bit cooler. There is a lot of heat dissipated in the "R" of the CRCLC, and the heat seems to stay more localized to that corner vs the giant regulator heatsink I had in there before.
3. I didn't like the way the regulator was mounted. I couldn't figure out a way to mount that giant heatsink to the top plate, and it was just putting stress on the mosfet pins.
4. Theoretically, I should be able to better hear the difference between rectifiers as well as the SS plugin now. Will do listening tests later.

B+ ranges from 165V - 200V depending on the rectifier plugged in, which is all within the spec of the original design. I can still use the SS rectifier plug-in if I want.

Other changes include: 
1. Putting back the 100uF film cap as the last PSU cap.
2. Wiring the 12AU7 socket in series with the 6J5 sockets. I can now use either the 6J5's or a 12AU7.

It sounds dang good and is dead silent. I'm done for now... it's going back to the office. I'm tired of listening to my earbuds at work!


----------



## lalawilson168

carlman14 said:


> My BHC has been in open heart surgery for the last couple weeks. I did a comparison between using the regulator from my last post and a more traditional CRCLC power supply. I decided to stick with the CRCLC for a few reasons:
> 
> 1. The sound differences between the two PSU implementations were very minor (if any)... minor enough to justfiy not using the regulator. I can save the regulator for another project now.
> 2. CRCLC is running a bit cooler. There is a lot of heat dissipated in the "R" of the CRCLC, and the heat seems to stay more localized to that corner vs the giant regulator heatsink I had in there before.
> ...


This is a mammoth


----------



## cddc

carlman14 said:


> 3. I didn't like the way the regulator was mounted. I couldn't figure out a way to mount that giant heatsink to the top plate, and it was just putting stress on the mosfet pins.



Consider water cooling for the mosfet...LOL






Just kidding, excellent workmanship!


----------



## jonathan c

carlman14 said:


> My BHC has been in open heart surgery for the last couple weeks. I did a comparison between using the regulator from my last post and a more traditional CRCLC power supply. I decided to stick with the CRCLC for a few reasons:
> 
> 1. The sound differences between the two PSU implementations were very minor (if any)... minor enough to justfiy not using the regulator. I can save the regulator for another project now.
> 2. CRCLC is running a bit cooler. There is a lot of heat dissipated in the "R" of the CRCLC, and the heat seems to stay more localized to that corner vs the giant regulator heatsink I had in there before.
> ...


Honey, I shrunk the Pendant?...


----------



## carlman14

cddc said:


> Consider water cooling for the mosfet...LOL



Don't give me any ideas! I think I'll leave the water cooling to the PCs for now.



jonathan c said:


> Honey, I shrunk the Pendant?...



Funny you mention that, I'm actually building out an EL84-based amp (like the pendant) right now. We'll see how it turns out.


----------



## cddc (Feb 18, 2021)

carlman14 said:


> Funny you mention that, I'm actually building out an EL84-based amp (like the pendant) right now. We'll see how it turns out.



Just checked EL84, it's a pentode.

I think I read that triodes generally have better linearity than pentodes, have you considered triodes like 2A3 or 300B? Or what makes you choose EL84 for your future amp? Is it because there are more EL84 variants you can choose from? Just curious.


----------



## carlman14

cddc said:


> Just checked EL84, it's a pentode.
> 
> I think I read that triodes generally have better linearity than pentodes, have you considered triodes like 2A3 or 300B? Or what makes you choose EL84 for your future amp? Is it because there are more EL84 variants you can choose from? Just curious.



Good question! I had a really bad experience building a 45-based headphone amp last year based around the tubelab SE circuit. I just couldn't get working well enough for headphone use. It was very noisy, and no matter how I tweaked it, I couldn't get the hum to go away. It seems like everyone else is using that circuit for speakers, not headphones, so maybe that's my fault. 

Anyway, people seem to really love EL84 amplifiers like the pendant, so I wanted to see for myself! I also know someone who built the same amp recently and he said it sounds wonderful. Also... a lot of the parts I had leftover from the 45 amp are compatible with the EL84 including my output transformers... So the cost of starting over is minimal.


----------



## CAJames

I know nothing about the pendant amp, but I do know that EL84s can be wired to work as a triode. You give up a lot of power, but gain, I’ll call it “musicality”, which is a good trade off for a headphone amp.


----------



## cddc

carlman14 said:


> Good question! I had a really bad experience building a 45-based headphone amp last year based around the tubelab SE circuit. I just couldn't get working well enough for headphone use. It was very noisy, and no matter how I tweaked it, I couldn't get the hum to go away. It seems like everyone else is using that circuit for speakers, not headphones, so maybe that's my fault.
> 
> Anyway, people seem to really love EL84 amplifiers like the pendant, so I wanted to see for myself! I also know someone who built the same amp recently and he said it sounds wonderful. Also... a lot of the parts I had leftover from the 45 amp are compatible with the EL84 including my output transformers... So the cost of starting over is minimal.




Cool, I do see good reports on EL84 and its amps like the pendant. It seems to have a nice warm tune. I wish you best of luck building a wonderful sounding EL84 amp.


----------



## cddc

CAJames said:


> I know nothing about the pendant amp, but I do know that EL84s can be wired to work as a triode. You give up a lot of power, but gain, I’ll call it “musicality”, which is a good trade off for a headphone amp.




That's true, triode-strapped pentodes can sound very good, I think the "musicality" comes from its enhanced linearity.


----------



## carlman14

CAJames said:


> I know nothing about the pendant amp, but I do know that EL84s can be wired to work as a triode. You give up a lot of power, but gain, I’ll call it “musicality”, which is a good trade off for a headphone amp.





cddc said:


> That's true, triode-strapped pentodes can sound very good, I think the "musicality" comes from its enhanced linearity.



I'm pretty sure Ampsandsound amps are all triode strapped. It looks like a pentode/triode switch isn't that hard to implement. I'll give both modes a try. Thanks for the suggestion!


----------



## DenverW

lalawilson168 said:


> Proud crack and SB owner here, wanna ask wheres the best place to get your hands on some munsdorf caps and which one I should be buying for the crack?
> 
> Also if any crackatwoa owners here and shed some light on whether it's a noticeable upgrade from the crack plus sb? I find very little review and impressions of the crackatwoa hence the ask . Cheers



Here is a posting that I've had my eye on.  I cannot comment on the quality of the cap.

https://www.ebay.com/itm/PAIR-TWO-M...apacitor-Cap-100uf-100-uf-350VDC/312264038976

Sorry it took me so long to reply.


----------



## DenverW

Bruc3 said:


> Who has paired both the Bendix 6080 and Tung Sol 5998 with their Crack?
> 
> Which did you prefer and why?
> 
> I have a Bendix 6080 incoming, and also considering to get a 5998 pair eventually.



I prefer the 5998/421A coke bottle style tubes to the 6080 style.  They are a bit brighter, but when paired with a quality input tube that can balance them a bit I find the combo to have more soundstage and clarity than trying to brighten a 6080 tube.


----------



## jonathan c

DenverW said:


> Here is a posting that I've had my eye on.  I cannot comment on the quality of the cap.
> 
> https://www.ebay.com/itm/PAIR-TWO-M...apacitor-Cap-100uf-100-uf-350VDC/312264038976
> 
> Sorry it took me so long to reply.


My Bottlehead Crack 1.1 (speedball +) was built by James C at HeadAmp Builder and has  these capacitors. While I cannot vouch for the capacitors per se, I will say that the BHC sounds fantastic - the heart of my listening system #2.


----------



## Bruc3

DenverW said:


> I prefer the 5998/421A coke bottle style tubes to the 6080 style.  They are a bit brighter, but when paired with a quality input tube



So whats some quality input tubes you recommend to pair with the 5998?


----------



## DenverW

Bruc3 said:


> So whats some quality input tubes you recommend to pair with the 5998?



You want tubes with good, lush tone.  High end would be the amperex welded 12au7 45 degree getter.  Mid would be a Siemens chrome 12au7.  There are several 6sn7 that work, such as a Ken rad.


----------



## jonathan c

DenverW said:


> You want tubes with good, lush tone.  High end would be the amperex welded 12au7 45 degree getter.  Mid would be a Siemens chrome 12au7.  There are several 6sn7 that work, such as a Ken rad.


Here are a few 12au7-type tubes, with a TS 5998, that have thrilled me in the BHC (and in the Woo WA3):  Amperex PQ 7316, Brimar CV4003, Lansdale 12AU7.


----------



## cddc

jonathan c said:


> Here are a few 12au7-type tubes, with a TS 5998, that have thrilled me in the BHC (and in the Woo WA3):  Amperex PQ 7316, Brimar CV4003, Lansdale 12AU7.



Never heard the Lansdale 12AU7, but when folks were into the Frankenstein frenzy 1 or 2 years ago I bought a genuine Lansdale 7N7 in NOS condition, you know, with the yellow CBRZ Lansdale stencil shining on the glass.

I bought this tube because I initially thought it might sound like 6SN7W, because this tube shares a lot of structural commonalities with 6SN7W - they both have long glass bottle with heavy chrome top, they both have a robust extra supporting rod between the 2 plates, and the plates themselves are quite similar. But,  to my disappointment the Lansdale Frankenstein sounds nowhere like the 6SN7W, not even close. I won't say the Lansdale 7N7 Frankie a bad sounding tube, actually it's still a good sounding tube, it's just a completely different flavor. Maybe one day I shall sell it to those Lyr 3 folks, the Lansdale Frankie is still one of their favorite tubes on Lyr3 ...LOL


----------



## DenverW (Feb 21, 2021)

Alrighty.  I have officially  been defeated by the crackatwoa.  I don’t think I’m going to be able to get this kit working.  I’ll see what options I have from Bottlehead.

Edit:  hey, I’m a 1000+ headfier now!


----------



## cddc

Congrats, 500 more posts to go, to become a Headphoneus Supremus . Me too a 1000+ member...but I think I'll join the Headphoneus Supremus club much later as I'm quite slow in posting.

Get some good resistance and voltage measurements on your cracka2a, and ask Paul & Paul on the BHC forum, they are normally super helpful in building the BH kits.


----------



## DenverW

cddc said:


> Congrats, 500 more posts to go, to become a Headphoneus Supremus . Me too a 1000+ member...but I think I'll join the Headphoneus Supremus club much later as I'm quite slow in posting.
> 
> Get some good resistance and voltage measurements on your cracka2a, and ask Paul & Paul on the BHC forum, they are normally super helpful in building the BH kits.



I’ve been going that route for the last week plus.  Unfortunately there’s not a clear idea of what to work on, other than rewire and resolder Pretty much everything, so that’s the feedback I’ve been getting. I’ve been doing that for a long while and its Not fixing the issues.  In fact, tonight was the last straw, as I worked on the low current board only to have two additional led stop working.


----------



## Tom-s

That’s not a setback. It’s more information to work with! Don’t give up yet. Don’t know if you ever build a stock Crack? But you could repurpose the resistors from the pre speedball Crack to get the CCS issues out of the equation (driver tube).


----------



## DenverW

Tom-s said:


> That’s not a setback. It’s more information to work with! Don’t give up yet. Don’t know if you ever build a stock Crack? But you could repurpose the resistors from the pre speedball Crack to get the CCS issues out of the equation (driver tube).



I've built a stock crack, then added speedball, then modded the pants off it.  This crackatwoa is a whole different beast .


----------



## Bruc3

I have owned the La Figaro 339 for a few Months now, and have recently bought a BH Crack + SB a few days ago.

Here is my impressions of the Figaro vs the Crack so far.

    Originally when I auditioned the Crack I thought I may have liked it more than the Figaro, but now I am not so sure.

   I was pairing with my CMA12 as the DAC and Sen HD800S headphones.

    BH Crack + speedball, with RCA 6as7g +  5814:

    - brighter sound, bit more detailed
    - More forward and aggressive sound, more similar to my solid state than the Figaro
    - nice bass impact
    - dynamic sound (more obvious to hear the quiet and louder passages in music)

    La Figaro 339, with Mullard 6080 + EF86:

    - more smoother sound, I guess the word I am looking for is euphoric sound
   - bass impact seems roughly equal,  but I feel the Figaro goes bit deeper
   - Has a bit more reverb sound going on, noticeable on the vocals etc.
   - At times the Figaro seem to have a bit more holographic sound

    Both of these amps have:
    - Nice "organic" sound you can say when compared to my SS CMA12 amp.
    - Both have wider/deeper soundstage than my CMA12, probably the Figaro had slightly the widest, but bit difficult for me to tell mostly.
    - Seems they both have punchy bass and cant say I feel one is better than the other

    I need to spend more time with these and listen to more music. I would say I would be happy with any of these amps.

    But if I had to choose now purely based on sound, I think Figaro is my pick, but not by alot. BH Crack is damn impressive for the price I think, and comes in smaller package with only need for 2 tubes, also I really dig the wood look.


----------



## GreenNeedle (Feb 21, 2021)

No real changes to mine.  Still using the Mazda with the Tung-Sol 5998.  I do intend to sort out the wiring within to try and eliminate the buzz I get with 6SN7 (with any adaptor) but I do like this Mazda sound.  Yet more pictures in the past few pages with very tight twisted wiring from transformer to the sockets just makes me think that is where I should focus.  Mine is not nearly as tight, nor angled so I want to sort that out.

BTW they are HD580 precisions in disguise, not HD 600s.


----------



## haasaaroni

Bruc3 said:


> I have owned the La Figaro 339 for a few Months now, and have recently bought a BH Crack + SB a few days ago.
> 
> Here is my impressions of the Figaro vs the Crack so far.
> 
> ...


Awesome to hear! Does definitely sound like the Crack is the better amp for the Aeolus of the two, like you’d mentioned before. It definitely benefits from a livelier, more dynamic sound. I bet the 6XX sounds amazing on both, to say nothing of the 800S.


----------



## cddc (Feb 22, 2021)

Bruc3 said:


> I have owned the La Figaro 339 for a few Months now, and have recently bought a BH Crack + SB a few days ago.
> 
> Here is my impressions of the Figaro vs the Crack so far.
> 
> ...




Thanks for taking up the time to write this great comparison. Very nice impressions on both amps!

I personally think the RCA 6AS7G and 5814 tubes you used on your BHC for the evaluation kinda put the BHC in a huge disadvantageous position. Lots of people find the RCA 6AS7G tube to be sloppy muddy veiled sounding, me included, I personally would put it to the bottom of my BHC power tube ranking. Even a cheap $10 Russian Winged C can easily kick its ass.

If you could unplug one of the Mullard 6080 tubes (which is a great power tube IMHO) from your LF339 or a Bendix 6080 (another great tube BTW), and put it on your BHC, then it would be more like an apple-to-apple comparison. In my estimation of the importance of power vs driver tube on BHC, the power tube accounts for 60% and the driver tube 40%. A sloppy power tube like the RCA 6AS7G will definitely doom the wonderful BHC sounding.

The 5814 tube is also a so so type driver tube, nothing spectacular. If you could use one of the better 12AU7 driver tubes, like Mazda, Siemens, Mullard, or Amperex that @DenverW or @GreenNeedle mentioned, things could also turn better.

Now, I am not too familiar with the EF86 tube and how it is used in LF339. It is a pentode, so I would guess most likely it is used as a triode-strapped pentode in LF339, since we don't need a lot of power from pentodes in the driver stage, and linearity is the key in this stage. I would suggest using the same power tube (Mullard 6080 or Bendix 6080) on both amps, and using the driver tube from the same brand (say, Mullard, Sylvania, RCA) for a fair apple-to-apple evaluation.



Eidt: to correct some typos, the 6AS7G was meant to be the RCA 6AS7G, I have no problem with other 6AS7G's...LOL


----------



## HiFiHawaii808

Bruc3 said:


> I have owned the La Figaro 339 for a few Months now, and have recently bought a BH Crack + SB a few days ago.
> 
> Here is my impressions of the Figaro vs the Crack so far.
> 
> ...


Thanks for this direct comparison.   I've always wondered how the Figaro compares with the BHC.    I am now looking at either the ZMF Pendant or another Ampsandsound tube amp as my next project.     Or, getting a transportable amp like a C9 that has tubes as an option.


----------



## HiFiHawaii808

cddc said:


> Thanks for taking up the time to write this great comparison. Very nice impressions on both amps!
> 
> I personally think the RCA 6AS7G and 5814 tubes you used on your BHC for the evaluation kinda put the BHC on a huge disadvantageous position. Lots of people find the 6AS7G tube to be sloppy muddy veiled sounding, me included, I personally would put it to the bottom of my BHC power tube ranking. Even a cheap $10 Russian Winged C can easily kick its ass.
> 
> ...


I am going to try some of those input tubes you mentioned.    I currently use the cbs hytron 5814a.   I really only focused on power tubes in my last tube rolling project.

Still love my Western Electric 421A as power tube.


----------



## cddc

HiFiHawaii808 said:


> I am going to try some of those input tubes you mentioned.    I currently use the cbs hytron 5814a.   I really only focused on power tubes in my last tube rolling project.
> 
> Still love my Western Electric 421A as power tube.




For the miniature 12AU7 driver tubes, try those European glass bottles, you'll definitely find a lot of surprises.


----------



## GreenNeedle

HiFiHawaii808 said:


> I am going to try some of those input tubes you mentioned.    I currently use the cbs hytron 5814a.   I really only focused on power tubes in my last tube rolling project.
> 
> Still love my Western Electric 421A as power tube.


I would add the Brimar CV4003 to the list above.  Everybody's preferences are different but for me it is quite similar to the Mazda(s) and probably more easily available outside Europe than the Mazda(s.)  The Mazda comes in 2 forms.  The 12AU7 (UK) and ECC82 (Foreign) They sound and look the same other than the print/etch on the glass. Both Mazdas and the Brimar are relatively cheap as well. <$30


----------



## haasaaroni

All this talk of tube rolling has got me wishing my Crack were built already! My kit should be shipping next week...

I would think it's not the _smartest_ thing to get a set of NOS tubes before I even start building the Crack, but I really want to hear this thing in its full glory as soon as it's set up. Any good first steps you all would recommend taking as a replacement for the stock tubes? The Brimar CV4003 looks temtping, being so readily available.


----------



## hikaru12

haasaaroni said:


> All this talk of tube rolling has got me wishing my Crack were built already! My kit should be shipping next week...
> 
> I would think it's not the _smartest_ thing to get a set of NOS tubes before I even start building the Crack, but I really want to hear this thing in its full glory as soon as it's set up. Any good first steps you all would recommend taking as a replacement for the stock tubes? The Brimar CV4003 looks temtping, being so readily available.



I ordered mine last Thursday so hoping to having a shipping notice this week myself. I can't wait to pair them with my recently aquired Eikons. Had I built one back in the day when I had my Atticus I probably would have kept it.


----------



## cddc

haasaaroni said:


> All this talk of tube rolling has got me wishing my Crack were built already! My kit should be shipping next week...
> 
> I would think it's not the _smartest_ thing to get a set of NOS tubes before I even start building the Crack, but I really want to hear this thing in its full glory as soon as it's set up. Any good first steps you all would recommend taking as a replacement for the stock tubes? The Brimar CV4003 looks temtping, being so readily available.



I'd suggest you to buy tubes only after your Crack is completed, unless of course you've got another similar amp to test the incoming tubes. Most tube sellers/vendors/stores don't test their tubes on amps, they only test tubes on tube testers, and lots of them don't test their tubes at all. And even if a tube tests good in the tester, it could still hum or buzz or be microphonic on your amp (though the possibility is pretty low), given those NOS tubes have been in sleep for decades. If you have a completed Crack, you can return the defective tube to the seller before it's too late.

A good starter power tube to consider is the Russian Winged-C, it has a nice deep bass and large soundstage. You can get them really cheap, normally around $10 + shipping from Ukraine or Russia. This tube was introduced to me by @Tom-s years ago on the BHC forum, and I can't stop recommending it to any BHC owner as a starter tube for its high price/performance ratio. From this up you would have to shed lots of money , the top tier ones include 5998/421A, 7236, GEC 6AS7G/6080, Mullard 6080, etc.


----------



## maxpudding

cddc said:


> I'd suggest you to buy tubes only after your Crack is completed, unless of course you've got another similar amp to test the incoming tubes. Most tube sellers/vendors/stores don't test their tubes on amps, they only test tubes on tube testers, and lots of them don't test their tubes at all. And even if a tube tests good in the tester, it could still hum or buzz or be microphonic on your amp (though the possibility is pretty low), given those NOS tubes have been in sleep for decades. If you have a completed Crack, you can return the defective tube to the seller before it's too late.
> 
> A good starter power tube to consider is the Russian Winged-C, it has a nice deep bass and large soundstage. You can get them really cheap, normally around $10 + shipping from Ukraine or Russia. This tube was introduced to me by @Tom-s years ago on the BHC forum, and I can't stop recommending it to any BHC owner as a starter tube for its high price/performance ratio. From this up you would have to shed lots of money , the top tier ones include 5998/421A, 7236, GEC 6AS7G/6080, Mullard 6080, etc.


Agreed on the Russian winged-C tube, bought a few of them and I really like the sound. The Melz 1578 and the Foton 6N8S do sound quite nice as well in the driver’s seat.


----------



## cddc

Folks, stay away from this idiot, *wege_high_tube*, aka "the Italian BangyBang". He is a sheer liar/scammer, look what he is doing - selling a pair of fake GEC 6AS7G for $450, it's actually a pair of Russian Winged-C rebranded as Haltron, worth $20 at most.

https://www.ebay.com/itm/6AS7G-TUBE...LIFIER-A1834-6080-VINTAGE-STEREO/254195578638


----------



## jonathan c

cddc said:


> Folks, stay away from this idiot, *wege_high_tube*, aka "the Italian BangyBang". He is a sheer liar/scammer, look what he is doing - selling a pair of fake GEC 6AS7G for $450, it's actually a pair of Russian Winged-C rebranded as Haltron, worth $20 at most.
> 
> https://www.ebay.com/itm/6AS7G-TUBE...LIFIER-A1834-6080-VINTAGE-STEREO/254195578638


Thank you for the alert!


----------



## DeweyCH

Crack is in the house. Time to build!


----------



## jonathan c

DeweyCH said:


> Crack is in the house. Time to build!


Get cracking! Keep posting!


----------



## DeweyCH

jonathan c said:


> Get cracking! Keep posting!


Paint and stain drying. Went with a satin nickel for the top plate and bell and some Minwax Provincal for the case. I’ll pop pics up when they’re dry.


----------



## InstantSilence

Would this amp work with audeze Lcd4z?  Idk how to read how combo of amps/cans work.


----------



## DenverW

InstantSilence said:


> Would this amp work with audeze Lcd4z?  Idk how to read how combo of amps/cans work.



No, this OTL amp works with headphones that have higher impedance, at or over 200-300 ohms.  The LCD line would have bass roll off, and the bass will sound poor.


----------



## cddc

InstantSilence said:


> Would this amp work with audeze Lcd4z?  Idk how to read how combo of amps/cans work.



As @DenverW answered, Crack or other OTL amps won't work well with low impedance headphones like LCD's. 

You should consider Bottlehead S.E.X. or Bottlehead Mainline amp instead, which work for both high impedance and low impedance headphones.


----------



## DenverW

cddc said:


> As @DenverW answered, Crack or other OTL amps won't work well with low impedance headphones like LCD's.
> 
> You should consider Bottlehead S.E.X. or Bottlehead Mainline amp instead, which work for both high impedance and low impedance headphones.



I will hopefully be trying the s.e.x. Kit soon, but I find the mainline kinda meh with some Planar.  Quad era 1 and lcd2c were good, but hifiman He-500 was meh.


----------



## cddc

Tubes in general are high output impedance devices, with no output transformer (i.e. OTL or Output TransformerLess), they normally work well only with high impedance headphones. Low impedance headphones normally need output transformer to match impedance with tubes.

But output transformer has 2 major problems: 1) dramatically increases the amp cost, a high quality output transformer like Audio Note or Lundahl can cost a lot of $$$ ; 2) output transformer will alter the amp sound, you are no longer hearing the pure tube sound from OTL amps, instead the sound is now somewhat shaped by output transformers, which is really bad IMHO, we can't roll output transformers after all, right?  But in case of 300B or 2A3 amps, you'll have to use output transformers


----------



## Bruc3

InstantSilence said:


> Would this amp work with audeze Lcd4z?  Idk how to read how combo of amps/cans work.



If you want an OTL tube amp that would work well with a range of different impedance headphones, have a look at the La Figaro 339.


----------



## jonathan c

cddc said:


> Tubes in general are high output impedance devices, with no output transformer (i.e. OTL or Output TransformerLess), they normally work well only with high impedance headphones. Low impedance headphones normally need output transformer to match impedance with tubes.
> 
> But output transformer has 2 major problems: 1) dramatically increases the amp cost, a high quality output transformer like Audio Note or Lundahl can cost a lot of $$$ ; 2) output transformer will alter the amp sound, you are no longer hearing the pure tube sound from OTL amps, instead the sound is now somewhat shaped by output transformers, which is really bad IMHO, we can't roll output transformers after all, right?  But in case of 300B or 2A3 amps, you'll have to use output transformers


Is it time to invent a transformer adapter?...


----------



## cddc

jonathan c said:


> Is it time to invent a transformer adapter?...




Good idea...there will be a huge market for plug-and-play type of output transformers and transformer adapters


----------



## DeweyCH

It's begun (no the staining process isn't finished yet, yes I'll be adding a clear-coat when it's done with stain, yes I probably need to do another coat on the top plate b/c my wife dropped it while it was drying)


----------



## cddc

DeweyCH said:


> It's begun (no the staining process isn't finished yet, yes I'll be adding a clear-coat when it's done with stain, yes I probably need to do another coat on the top plate b/c my wife dropped it while it was drying)



Looks good!


----------



## DeweyCH

Almost done. Got through the point of putting in caps around the transformer and had to stop for the night. I’ll add photos tomorrow. Instructions are very easy to follow. Hardest thing so far was those goddamned fiddly leds


----------



## DeweyCH

Time to go through the instructions from top to bottom and check each one to make sure I did it right and soldered it solidly, then it's time to rock.


----------



## Tom-s

DeweyCH said:


> Time to go through the instructions from top to bottom and check each one to make sure I did it right and soldered it solidly, then it's time to rock.



@DeweyCH ; It's important to make a mechanical connection before you make a solder connection. This, helps to avoid loose wires in your amps.

Make sure to really secure all ground wires. Fill the holes if you can't get a mechanical connection. For instance on your power input connector. 

Your input wiring is very long, loosely braided and close to the heater wiring. This could make for unwanted hum/noise issues. I'd shorten the input wiring and move it as far from the heater's/HV as physically possible.


----------



## DeweyCH

Tom-s said:


> @DeweyCH ; It's important to make a mechanical connection before you make a solder connection. This, helps to avoid loose wires in your amps.
> 
> Make sure to really secure all ground wires. Fill the holes if you can't get a mechanical connection. For instance on your power input connector.
> 
> Your input wiring is very long, loosely braided and close to the heater wiring. This could make for unwanted hum/noise issues. I'd shorten the input wiring and move it as far from the heater's/HV as physically possible.


Appreciate it. I will shorten and tighten the input wiring and make sure everything is solidly connected.


----------



## cddc (Mar 5, 2021)

DeweyCH said:


> Time to go through the instructions from top to bottom and check each one to make sure I did it right and soldered it solidly, then it's time to rock.




Nice. Just a kind reminder, keep the braided RCA signal wires away from the green heater wires, otherwise noises from the AC heater wires can possibly bleed into your signal path.

Edit: Tom has also found it, haha


----------



## DeweyCH

Better I hope.


----------



## DeweyCH

Hmm. Voltages and resistances all check out spot-on. But I've got a ground hum. Time to look for crap solder.


----------



## cddc

DeweyCH said:


> Better I hope.



Bend the left cap straight up to keep it away from the braided RCA signal wires to see if it helps.


----------



## DeweyCH

cddc said:


> Bend the left cap straight up to keep it away from the braided RCA signal wires to see if it helps.


Didn't help. I found a bad solder on the ground for the pot, too, so there's LESS hum, but still some. I'll find it. In the instructions it says to check for continuity between the bell and the ground screw; that would be checking to make sure there's zero resistance between the screws on the bell and that ground screw in the plate, yes? I did paint the top of the bell and the plate, so I want to make sure I've got a solid ground connection there.


----------



## cddc

DeweyCH said:


> Didn't help. I found a bad solder on the ground for the pot, too, so there's LESS hum, but still some. I'll find it. In the instructions it says to check for continuity between the bell and the ground screw; that would be checking to make sure there's zero resistance between the screws on the bell and that ground screw in the plate, yes? I did paint the top of the bell and the plate, so I want to make sure I've got a solid ground connection there.




Yes, that should make sure if the bell is grounded, but I guess it's not so important if the bell is even not grounded . Why? Because my bell is also not grounded...LOL.

I painted my bell with multiple layers of heavy paint, so the paint insulated the bell, and it took me a while to figure out why the resistance measurement on my bell is not correct. But I think it's not an issue.


----------



## cddc

DeweyCH said:


> Didn't help. I found a bad solder on the ground for the pot, too, so there's LESS hum, but still some. I'll find it. In the instructions it says to check for continuity between the bell and the ground screw; that would be checking to make sure there's zero resistance between the screws on the bell and that ground screw in the plate, yes? I did paint the top of the bell and the plate, so I want to make sure I've got a solid ground connection there.




I'd also suggestion you to check if there is any router or computer close to your Crack, if so move your Crack away from these possible sources of noises, and see if it helps. Before that make sure all your soldering joints are solid.


----------



## DeweyCH

cddc said:


> I'd also suggestion you to check if there is any router or computer close to your Crack, if so move your Crack away from these possible sources of noises, and see if it helps. Before that make sure all your soldering joints are solid.


Yeah, I'll have to go through all the joints again. There's buzzing even if it's nowhere near anything and has nothing plugged into the RCA jacks. It's also not the tubes; I checked a couple alternates I have lying about.


----------



## Mightygrey

It's been a while since I've visited the Crack thread, and it's got me thinking about tinkering again. A few ideas I might start plotting:

1. Adding a VU meter to the front panel 
2. Installing a Khadas toneboard 2 inside the chassis for an onboard DAC
3. Installing a Schiit Phono card next to the line-level RCA inputs (although I have no idea if this needs to be connected to the power supply or if it is really 'passive)
4. Adding RCA pre-outs


----------



## haasaaroni

cddc said:


> Yes, that should make sure if the bell is grounded, but I guess it's not so important if the bell is even not grounded . Why? Because my bell is also not grounded...LOL.
> 
> I painted my bell with multiple layers of heavy paint, so the paint insulated the bell, and it took me a while to figure out why the resistance measurement on my bell is not correct. But I think it's not an issue.


Dang this looks so clean! Y'all are impressing me with the paint jobs...I just got my kit, glued and stained the frame and painted the top plate and bell, and so far it looks like a 4th grade arts project


----------



## DeweyCH

cddc said:


> Yes, that should make sure if the bell is grounded, but I guess it's not so important if the bell is even not grounded . Why? Because my bell is also not grounded...LOL.
> 
> I painted my bell with multiple layers of heavy paint, so the paint insulated the bell, and it took me a while to figure out why the resistance measurement on my bell is not correct. But I think it's not an issue.


That is stunning. Very nicely done.


----------



## hikaru12

Hey all,

What kind of DACs are you guys pairing with the BHC? I’m hot rodding mines as a majority of you are but curious what is considered a good or bad pairing with it or if that depends entirely on the tubes used. I plan on getting a NOS DAC like the Menuet or Morpheus but don’t know if that would sound too warm with the BHC. Are neutral or brighter DACs a better pairing?


----------



## jonathan c

hikaru12 said:


> Hey all,
> 
> What kind of DACs are you guys pairing with the BHC? I’m hot rodding mines as a majority of you are but curious what is considered a good or bad pairing with it or if that depends entirely on the tubes used. I plan on getting a NOS DAC like the Menuet or Morpheus but don’t know if that would sound too warm with the BHC. Are neutral or brighter DACs a better pairing?


I use a Mojo Audio EVO Mystique d-a-c. It is a n/o/s R2R design - not to be confused with Chord Mojo. The BHC is a great match to the Mystique.


----------



## DeweyCH

Oooooooh, it's working! Doc B. over at the Bottlehead forums spotted that I hadn't properly soldered the black ground on the headphone jack, now it's... well, it's kinda glorious.


----------



## DeweyCH

Holy crap y'all I built an amp...


----------



## cddc

DeweyCH said:


> Oooooooh, it's working! Doc B. over at the Bottlehead forums spotted that I hadn't properly soldered the black ground on the headphone jack, now it's... well, it's kinda glorious.




It turned out to be a soldering joint problem eventually...

Glad Doc B caught it with his hawk eyes. I was about to question the soldering joints you did on the headphone jack earlier, which is a little bit different than mine (see the photo attached), but I thought Bottlehead might have changed their procedures over the years...


----------



## cddc (Mar 7, 2021)

Mightygrey said:


> It's been a while since I've visited the Crack thread, and it's got me thinking about tinkering again. A few ideas I might start plotting:
> 
> 1. Adding a VU meter to the front panel
> 2. Installing a Khadas toneboard 2 inside the chassis for an onboard DAC
> ...




1. Adding some VU meter will definitely make the amp look more beautiful, but I think the meter will add some additional load to the tubes/circuit, kinda like insert a damper into the circuit, so it might affect the performance a little bit if not carefully calculated/executed.

2. Regarding the onboard DAC, @carlman14 did a fantastic job on his Crack, you can refer to his onboard DAC mod:
https://www.head-fi.org/threads/crack-bottlehead-otl.476650/post-16187626

3.&4. I guess are the same thing, right? You want to add some Schiit plug-in for pre-amp output on Crack? It could be a great idea. IIRC, no one here has done it before, you can definitely try it out and let us know. It would be great to have some pre-outs to work with speaker amps.


----------



## jonathan c

DeweyCH said:


> Oooooooh, it's working! Doc B. over at the Bottlehead forums spotted that I hadn't properly soldered the black ground on the headphone jack, now it's... well, it's kinda glorious.


A really nice look. I like the driver tube socket and the match of the transformer cap and the chassis plate. Beautiful finish on the base!😄😄


----------



## cddc (Mar 6, 2021)

jonathan c said:


> A really nice look. I like the driver tube socket and the match of the transformer cap and the chassis plate. Beautiful finish on the base!😄😄



Agree, a very nice build. 

Have you put some clear coating or wax on your base, @DeweyCH? Why is it so shining?


----------



## DeweyCH

cddc said:


> Agree, a very nice build.
> 
> Have you put some clear coating or wax on your base, @DeweyCH? Why is it so shining?


Just some wipe on water based poly.


----------



## DeweyCH

jonathan c said:


> A really nice look. I like the driver tube socket and the match of the transformer cap and the chassis plate. Beautiful finish on the base!😄😄


Much appreciated! I’m not much of a wood or metal painter but it turned out pretty decent for me


----------



## cebuboy

hikaru12 said:


> Hey all,
> 
> What kind of DACs are you guys pairing with the BHC? I’m hot rodding mines as a majority of you are but curious what is considered a good or bad pairing with it or if that depends entirely on the tubes used. I plan on getting a NOS DAC like the Menuet or Morpheus but don’t know if that would sound too warm with the BHC. Are neutral or brighter DACs a better pairing?


I paired mine with a Bifrost 2, rca cleartop for the input, svetlana 6H5C power tube, russian film caps, and a choke. Sounds very nice.


----------



## cddc

DeweyCH said:


> Just some wipe on water based poly.



Aha, that's why it's so shiny


----------



## cddc

haasaaroni said:


> Dang this looks so clean! Y'all are impressing me with the paint jobs...I just got my kit, glued and stained the frame and painted the top plate and bell, and so far it looks like a 4th grade arts project




It will get better as you progress in the building


----------



## haasaaroni

Here, 4th grade arts project turned into an _actual_ arts project 🎨 I accidentally left some glue residue in certain places before applying the stain, so the glue spots didn't stain well and looked all funky. SO I just decided to go wild and paint over them with acrylics! Loving how personal this DIY stuff can be.

Just finished assembling the chassis, now time to get soldering


----------



## cddc

Nice mix of colors, quite unique


----------



## JaquesGelee (Mar 15, 2021)

Hey there,

yesterday i read the first time about it and flew asap through this forum.
Maybe already asked, but:

1. Is soldering this kit + upgrade doable with entry level experiences?
(soldered BNC plugs on RG58, N-Plugs on RG213, soldered and desoldered some semiconductors, done entry circuit pcb´s many years ago)
*Edit: ok, seems not, if i plan to modify it like i would.

2. where do i get finished rosewood casing?
3. Which tube is highly recommended as solid allrounder?
4. Which DAC do you use? I have Chord Mojo, Qutest in mind.

audiophile greetings


----------



## Mightygrey

JaquesGelee said:


> Hey there,
> 
> yesterday i read the first time about it and flew asap through this forum.
> Maybe already asked, but:
> ...


1. I've never used a soldering iron before, and I found it easily doable.

2. A hobby/hardware store. 

3. The stock tubes will be plenty fine for a good while unless you find them sonically lacking anything. After that, try a 5998 power tube. 

4. I use a Schiit Bifrost 2, or a Rega Planar 2 for sources. It won't matter too much as long as you feed it with well mastered and recorded music.


----------



## haasaaroni (Mar 16, 2021)

She lives! What a joy putting this thing together and being rewarded with such an incredible sound. Goes with my Aeolus like peanut better and crack...I mean, jelly 

Hearing just a _tiny_ bit of channel imbalance towards the right and a bit of sound in the right channel though (the stock power tube seems pretty microphonic). It's so little that I'm just assuming it's just tubes being tubes, and will see if using a different tube fixes the problem. Looked it over pretty well and didn't any cold joints or anything.


----------



## DeweyCH

haasaaroni said:


> She lives! What a joy putting this thing together and being rewarded with such an incredible sound. Goes with my Aeolus like peanut better and crack...I mean, jelly
> 
> Hearing just a _tiny_ bit of channel imbalance towards the right and a bit of sound in the right channel though (the stock power tube seems pretty microphonic). It's so little that I'm just assuming it's just tubes being tubes, and will see if using a different tube fixes the problem. Looked it over pretty well and didn't any cold joints or anything.


What in the name of all that's holy is that gorgeous base made of?


----------



## haasaaroni

DeweyCH said:


> What in the name of all that's holy is that gorgeous base made of?


You mean the stained wood with acrylic paint (and way more coats of poly than I could have ever needed)? Or the hammered black spray paint on the top plate?


----------



## DeweyCH

haasaaroni said:


> You mean the stained wood with acrylic paint (and way more coats of poly than I could have ever needed)? Or the hammered black spray paint on the top plate?


Former


----------



## haasaaroni

DeweyCH said:


> Former


Haha yeah, it’s just the regular wood that I messed up the staining on, painted over the mistakes with some cool acrylic colors, and dumped a pound of ploy onto


----------



## cddc

haasaaroni said:


> She lives! What a joy putting this thing together and being rewarded with such an incredible sound. Goes with my Aeolus like peanut better and crack...I mean, jelly
> 
> Hearing just a _tiny_ bit of channel imbalance towards the right and a bit of sound in the right channel though (the stock power tube seems pretty microphonic). It's so little that I'm just assuming it's just tubes being tubes, and will see if using a different tube fixes the problem. Looked it over pretty well and didn't any cold joints or anything.




Channel imbalance is one of the most common problems of potentiometers, especially at low volumes (6-9 am), mainly because a small displacement of the 2 wipers on the 2 resistive discs can cause a relatively large % difference in resistance between the 2 channels at low volumes, but as volume increases and the distances of the 2 wipers from their starting points increase, the % difference is becoming smaller and smaller (as its denominator increases) and channel imbalance normally will disappear at normal listening levels. If the imbalance at normal listening levels is tiny, you can possibly ignore it. If you can't stand it, you can upgrade the stock pot with some higher grade Alps pot or stepped attenuator.

You are both lucky and unlucky on the stock tubes...  I got the worst ever double-double from Bottlehead, GE + GE . Your Baldwin 12AU7 seems to be a Sylvania 12AU7, which is slightly better than my GE 12AU7 stock tube. Your GE 6AS7GA is also slightly better than my GE 6080 stock tube. The unfortunate part is your GE 6AS7GA seems microphonic. Give the tubes some burn-in time (20 hours, maybe) and see if the microphonics goes way. If not, clean the pins, or replace it with some better tubes. The stock tubes are just some basic tubes. A good starter tube that I always recommend to BHC fellows is the Russian 6H13C tube, nice and cheap, normally costs $10 + shipping from Ukraine or Russia.


----------



## haasaaroni

cddc said:


> Channel imbalance is one of the most common problems of potentiometers, especially at low volumes (6-9 am), mainly because a small displacement of the 2 wipers on the 2 resistive discs can cause a relatively large % difference in resistance between the 2 channels at low volumes, but as volume increases and the distances of the 2 wipers from their starting points increase, the % difference is becoming smaller and smaller (as its denominator increases) and channel imbalance normally will disappear at normal listening levels. If the imbalance at normal listening levels is tiny, you can possibly ignore it. If you can't stand it, you can upgrade the stock pot with some higher grade Alps pot or stepped attenuator.
> 
> You are both lucky and unlucky on the stock tubes...  I got the worst ever double-double from Bottlehead, GE + GE . Your Baldwin 12AU7 seems to be a Sylvania 12AU7, which is slightly better than my GE 12AU7 stock tube. Your GE 6AS7GA is also slightly better than my GE 6080 stock tube. The unfortunate part is your GE 6AS7GA seems microphonic. Give the tubes some burn-in time (20 hours, maybe) and see if the microphonics goes way. If not, clean the pins, or replace it with some better tubes. The stock tubes are just some basic tubes. A good starter tube that I always recommend to BHC fellows is the Russian 6H13C tube, nice and cheap, normally costs $10 + shipping from Ukraine or Russia.


Thanks for this! I had no idea the stock tubes vary so much between kits. I'm definitely loving the sound!

And yeah, thanks for bringing up burn-in. I actually think the slight noise went away already from just a couple hours! And the channel imbalance isn't terrible (and happens at normal listening levels with the HD6XX), as my hearing actually drifts further to the left than normal anyway. So the right-leaning imbalance is having the effect of balancing all the images that sound "off" on more well-balanced gear


----------



## QuasiSpecies

haasaaroni said:


> She lives! What a joy putting this thing together and being rewarded with such an incredible sound. Goes with my Aeolus like peanut better and crack...I mean, jelly
> 
> Hearing just a _tiny_ bit of channel imbalance towards the right and a bit of sound in the right channel though (the stock power tube seems pretty microphonic). It's so little that I'm just assuming it's just tubes being tubes, and will see if using a different tube fixes the problem. Looked it over pretty well and didn't any cold joints or anything.



Wow! This is a beautiful build, A+

I love the Crack with ZMF headphones!


----------



## DeweyCH

Can anyone give me a kind of overview of pot resistances and how they change things? I did a lot of modding on a Darkvoice, and one of the issues I had was that it was extremely loud extremely fast - couldn't turn it more than a tiny bit without blowing my eardrums out through my nose. So I went from the stock crappy 100k pot to a 50k with a 47k shunt, and that solved my problem - volume was nicely balanced due to the shunt and didn't get to "too loud" until like 1 o'clock.

Now I've got a 10k stepped attenuator in there, which seems to have gone a little bit too far in the other direction.

So as I understand it, bumping down the resistance of the pot makes the volume increase more slowly. This has been my takeaway. But the pot replacement discussions around the Crack always seem to default to the 100k resistance the stock one comes with. Other than slower volume gain, what would, say, a 20k pot in my Crack do to the sound/build/etc?

Thank you!


----------



## Bonddam

I ain't got the balls to build one so I bought the classified option. Wanted a dedicated amp for these guys


----------



## CaptainFantastic

Hi everyone, I am new to this thread. I have a small army of high-impendence headphones that apparently would pair well with the BHC. Unfortunately, I also have a small army of quality 6922 tubes that I somehow would like to get good use out of.

Is it possible to have a Crack built to take 6922/E88CC as an input tube instead of the standard 12AU7? Or is that a) too complex to pull off or b) not recommended, not a good synergy in this amp.


----------



## Bonddam (Mar 18, 2021)

Im going to be using my Bendix 6080WB but don't know which driver to choose. Any driver recommendations?


----------



## jonathan c

CaptainFantastic said:


> Hi everyone, I am new to this thread. I have a small army of high-impendence headphones that apparently would pair well with the BHC. Unfortunately, I also have a small army of quality 6922 tubes that I somehow would like to get good use out of.
> 
> Is it possible to have a Crack built to take 6922/E88CC as an input tube instead of the standard 12AU7? Or is that a) too complex to pull off or b) not recommended, not a good synergy in this amp.


Rather than rebuild a BHC, you might use a 6922 (top) -> 12au7 (bottom) adapter. These can be found on EBay or you could have Head-Fier @Deyan build one for you. (He built me two of the opposites - great workmanship!)


----------



## DeweyCH

Bonddam said:


> Im going to be using my Bendix 6080WB but don't know which driver to choose. Any driver recommendations?


I've been having good success with a RCA clear-top 12AU7. I'll probably end up using 6SN7s with an adapter mostly, but that's more about the tubes I have.


----------



## jonathan c

DeweyCH said:


> I've been having good success with a RCA clear-top 12AU7. I'll probably end up using 6SN7s with an adapter mostly, but that's more about the tubes I have.


Ditto Dewey! The RCA clear-top is an excellent 12AU7 tube and does not cost limbs totaling ten digits. Two more suggestions: Philips BEL 12AU7 and Lansdale 12AU7 (long plate). These match very well, to my ears, with a variety of 6080s: Brimar CV5008, Philips, Raytheon in the BHC and Woo WA3 (w/adapter).


----------



## CaptainFantastic (Mar 19, 2021)

[deleted]


----------



## GreenNeedle

DeweyCH said:


> It's begun (no the staining process isn't finished yet, yes I'll be adding a clear-coat when it's done with stain, yes I probably need to do another coat on the top plate b/c my wife dropped it while it was drying)


What have you finished the top with.  looks nice.   Wood case looks excellent.  Nicely done.


----------



## GreenNeedle

hikaru12 said:


> Hey all,
> 
> What kind of DACs are you guys pairing with the BHC? I’m hot rodding mines as a majority of you are but curious what is considered a good or bad pairing with it or if that depends entirely on the tubes used. I plan on getting a NOS DAC like the Menuet or Morpheus but don’t know if that would sound too warm with the BHC. Are neutral or brighter DACs a better pairing?


I'm using Topping D30.  It is linked to my Denon and is a marginal improvement, maybe placebo but sounds good.


----------



## DenverW (Mar 24, 2021)

I do not know the seller, so perhaps someone with experience with him can chime in, but in my opinion these are the best of the best tubes for the crack.  45 degree slanted D getter welded plate amperex 12au7.  Sorry, 6SN7, but this tube beats ya .

https://www.ebay.com/itm/373508207981

Seller has another pair that tests lower for less.  If he tests them at all .


----------



## Bonddam

Crack? I think the new name for xtcy MOLLY. Never felt euphoria on crack. I'd build one when I get older. For the one I have I'll stain or automotive paint it. Leaning towards a shinny white paint job. 

Put in Bendix 6080wb and Baldwin. Don't let the Euforia people hear this but this is so much better. Aeolus just sounding so alive tons of detail crisp highs on silky smooth side with the right amount of bite. Currently judgement will be placed against WA2. As for WA33 Elite that wins hands down if it's 1266 TC but when Aeolus the Crack wins 

Wires if interested are Wire World.

Oh forgot the amp is dead silent.

 hands down no questions asked.


----------



## Bonddam

This is what's in my crack 

Crack + Speedball + Solen output caps + power supply shunt + cree diode rectifier bridge + Alps pot + 4 pin XLR plug (for balanced headphone cables) + shielded case + copper shield between PSU and signal electronics + 1% resistors


----------



## cddc

Bonddam said:


> This is what's in my crack
> 
> Crack + Speedball + Solen output caps + power supply shunt + cree diode rectifier bridge + Alps pot + 4 pin XLR plug (for balanced headphone cables) + shielded case + copper shield between PSU and signal electronics + 1% resistors




From the additional screws on the chassis I can imagine it's stuffed with lots of goodies. Just curious to see what's under the hood, any pics?

The Bendix 6080 on your Crack is a very nice tube, but the Baldwin 12AU7 is just a run-of-the-mill tube, nothing spectacular, it's actually a rebranded Sylvania 12AU7 made for Baldwin organs. So you'll have at least 20% more improvement if you were to replace the stock 12AU7 with some premium driver tubes. One good thing about Crack is that it has endless flavors of driver tubes, from the 12AU7 family to the 6SN7 familiar and their derivative families. You'll need some time to find out your favorite combo.


----------



## Bonddam

Here's under the hood. The one transformer was connected with plastic parts so even though it was super packed it still broke off. So I had to crazy glue it back to the posts and solder 3 wires back on. I can't wait to go home. 
In my chain I'm using a Wells Audio Cipher lvl 1 tube dac that further improves holographic and euphonic qualities of the amp. I'm most likely the only one with this setup. Put a pic of the dac internals it's built by hand so board components are hole to hole soldering. Price tag don't laugh because I have compared it to cheaper DAC's


----------



## cddc

Very nice, it's stuffed with almost all the mods I've seen on Crack, plus the shielding between the PSU and amplification compartments.

It's a pity that the plastic rods broke off during shipping, the builder should have used some metal standoffs, but glad you were able to fix it. The transformer is actually a choke, and I noticed one connection on it might not be solid (circled in red rectangular - not too sure on this, maybe just bad viewing angle), if so, add some solder, or cut the black wire, strip it and make a new connection. The choke is normally mounted in the red battery-shaped area behind the power transformer, but side mount is also okay as long as it's appropriately arranged.

It's actually the first time I saw a Wells Audio Cipher lvl 1 tube dac, very nice, quite complicated, lots of goodies inside, I can imagine it will sound sublime. It's a tough job for hand building though, lots of surface-mount components, hard to solder them by hand with iron (unless of course these SMD were soldered by machines).


----------



## Bonddam

cddc said:


> Very nice, it's stuffed with almost all the mods I've seen on Crack, plus the shielding between the PSU and amplification compartments.
> 
> It's a pity that the plastic rods broke off during shipping, the builder should have used some metal standoffs, but glad you were able to fix it. The transformer is actually a choke, and I noticed one connection on it might not be solid (circled in red rectangular - not too sure on this, maybe just bad viewing angle), if so, add some solder, or cut the black wire, strip it and make a new connection. The choke is normally mounted in the red battery-shaped area behind the power transformer, but side mount is also okay as long as it's appropriately arranged.
> 
> It's actually the first time I saw a Wells Audio Cipher lvl 1 tube dac, very nice, quite complicated, lots of goodies inside, I can imagine it will sound sublime. It's a tough job for hand building though, lots of surface-mount components, hard to solder them by hand with iron (unless of course these SMD were soldered by machines).


I took the picture before I fixed it I was running around with my kids and finding bad tubes on my WA33 while setting up a make shift soldering area on my pool table.
I wasn’t mad about it coming off as I like fixing things. I need to add some metal rods right now I super glued the crap out of the choke then taped it just in case the glue breaks. The first tube combo I did was perfect. Now I put a rca 6as7g in had a matched pair but the Filament or connection on the D getter Separated.


----------



## cddc (Mar 24, 2021)

Lots of heat around the PSU area, so definitely go with the metal rods, I suspect tape or glue won't last long.

Just noticed the 2 x 2.49K 1/8W resistors on the stock headphone jack seem missing from the replacement XLR jack, not sure how it will impact the system, someone with better knowledge about circuitry can possibly chime in...@Doc B., @Tom-s 


---------------
Edit: maybe not missing, there seem to be 2 black resistors hiding in the shade of the bottom-left prong.


----------



## Bonddam

I like the sound I'm happy. There where other mods that the builder got rid of, said they made no difference. What I did was use a spray that metals the plastic. Don't remember the name but it super dries the super glue and creates high temperature. Used this all the time in custom car audio. I know it works better because I glued my fingers together and the ass hole behind me thought it be funny to really super glue them together. It burned and luckily had the liquid that breaks apart superglue bonds boy did my hand stink.


----------



## PsilocybinCube

DenverW said:


> I do not know the seller, so perhaps someone with experience with him can chime in, but in my opinion these are the best of the best tubes for the crack.  45 degree slanted D getter welded plate amperex 12au7.  Sorry, 6SN7, but this tube beats ya .
> 
> https://www.ebay.com/itm/373508207981
> 
> Seller has another pair that tests lower for less.  If he tests them at all .



You know you like the 6sn7, give in to the dark side.  Stop fighting the allure of the beautiful octal base. 

I'm a 12bh7 advocate for the BHC.  It's an unsung hero.  The Brimar is relatively cheap and sounds delicious.


----------



## DenverW

PsilocybinCube said:


> You know you like the 6sn7, give in to the dark side.  Stop fighting the allure of the beautiful octal base.
> 
> I'm a 12bh7 advocate for the BHC.  It's an unsung hero.  The Brimar is relatively cheap and sounds delicious.



I think it’s a great tube.  I have a tung sol that sounds good, and I didn’t change any resistors to listen properly.  I’m still interested in setting up a switch for 12au7, 12BH7A and e80cc.

but true Jedi listen to the 12au7 on the amp it was intended for.

this is the way.


----------



## PsilocybinCube

DenverW said:


> I think it’s a great tube.  I have a tung sol that sounds good, and I didn’t change any resistors to listen properly.  I’m still interested in setting up a switch for 12au7, 12BH7A and e80cc.
> 
> but true Jedi listen to the 12au7 on the amp it was intended for.
> 
> this is the way.


Well, in honor of the you @DenverW I will roll in one of the 12au7 tubes you recommended long ago in a galaxy far far away.

I must be part Jedi and part Sith, because both sides beckon.  And this must mean that @Deyan is Sith, because he introduced my BHC to the 6sn7.


----------



## GreenNeedle

Does the copped shielding make any difference?  And what is it?  a sheet of film like tin foil.  I am still pondering ways  to remove the hum I get with 6SN7s so along with redoing the green wires from transformer to octal to noval I might try shielding as well.


----------



## Tom-s

cddc said:


> Lots of heat around the PSU area, so definitely go with the metal rods, I suspect tape or glue won't last long.
> 
> Just noticed the 2 x 2.49K 1/8W resistors on the stock headphone jack seem missing from the replacement XLR jack, not sure how it will impact the system, someone with better knowledge about circuitry can possibly chime in...@Doc B., @Tom-s
> 
> ...



These resistors are a ground reference for the output cap. These should be in place for safe / good operation of the amplifier. 

I'd advice against leaving these out.


----------



## Bonddam

Its not something you can get rid of if it comes from the tube


----------



## GreenNeedle

Bonddam said:


> Its not something you can get rid of if it comes from the tube


In reply to me?  I have 4 6sn7s all make this humm at varying levels.  I also have 2 adaptors.  The Garage one and an ebay one.  Both make the humm.  I don't get any humm with 12AU7s.  I'm figuring it is a difference in the current the 6SN7 takes to the 12AU7 being picked up by my wiring positioning or the wires not being twisted tightly enough.


----------



## Bonddam (Mar 26, 2021)

Delete wrong thread


----------



## Bonddam

I was 


cddc said:


> From the additional screws on the chassis I can imagine it's stuffed with lots of goodies. Just curious to see what's under the hood, any pics?
> 
> The Bendix 6080 on your Crack is a very nice tube, but the Baldwin 12AU7 is just a run-of-the-mill tube, nothing spectacular, it's actually a rebranded Sylvania 12AU7 made for Baldwin organs. So you'll have at least 20% more improvement if you were to replace the stock 12AU7 with some premium driver tubes. One good thing about Crack is that it has endless flavors of driver tubes, from the 12AU7 family to the 6SN7 familiar and their derivative families. You'll need some time to find out your favorite combo.


You need to help me. I'm looking at driver tubes and researched on google and the first one I looked up was Philips 7316 and the seller wants $390. Are there cheaper that sound good? Which ones do you recommend?


----------



## jonathan c

Bonddam said:


> I was
> 
> You need to help me. I'm looking at driver tubes and researched on google and the first one I looked up was Philips 7316 and the seller wants $390. Are there cheaper that sound good? Which ones do you recommend?


Some 12AU7 recommendations:  RCA clear-top, $50-$60 each; Philips BEL, $60-$70 each; Lansdale (Philco) long plate, $85-$95 each. I have found these: on EBay, Brent Jesse Recording, and Langrex respectively.


----------



## cddc

Bonddam said:


> I was
> 
> You need to help me. I'm looking at driver tubes and researched on google and the first one I looked up was Philips 7316 and the seller wants $390. Are there cheaper that sound good? Which ones do you recommend?



Unlike power tubes, there are so many different flavors of driver tubes, it's hard to recommend, some folks like 12AU7s, some like 6SN7s, some even go for E80CC/12BH7/6CG7 etc. I've been enjoying the Sylvania 6SN7W Metal Base recently, but it's a $200+ tube. 

7316 is a premium version of 12AU7, just like ECC802S to ECC82, but $390 is too steep, I personally wouldn't pay even a third of its price.


----------



## cddc

GreenNeedle said:


> Does the copped shielding make any difference?  And what is it?  a sheet of film like tin foil.  I am still pondering ways  to remove the hum I get with 6SN7s so along with redoing the green wires from transformer to octal to noval I might try shielding as well.




I think you can make a sheet of tin foil too, it shouldn't really matter as long as it's metal shielding. Just make sure ground the shielding and insulate it with some tape so that it won't short anything inside the cabinet.

Not sure of the source of hum on your 6SN7s, I have no problem using 6SN7 tubes.


----------



## skhan007

New Crack Speedball owner here! Just purchased a pre-owned unit and it arrived today! OK, so I really liking what I'm hearing so far. I do have a couple of newbie questions, if you all could be so kind:

Fist a photo...

I'll look forward to applying a nice stain/finish to the wood cab. I also have a big stash of tubes for my many guitar amps. I think I can only swap in various 12au7, 12at7 maybe, but I know 12ax7 will be too high gain. I do have several vintage 6SN7 as well. I'm curious about that as my preamp tube with the proper 9 to 8-pin adapter. 







Quick questions:

1) For those using an RME ADI-2, do you run the line out at a preferred level? I've chosen -5 dBu (-23 dBr). I didn't know if going to a higher level was advised. 

2) Mine came with a 188-5 GE 12Au7a and a JAN Phillips 6080WC 8526 (assuming 26th week of 1985). Do stock tubes vary? Could these be stock?

3) Any RCA cable recommendations? I'd like right angle and not into pricey, solid silver, etc. Not something I have the coin for at the moment. 

Thanks and happy to be part of the club!!


----------



## GreenNeedle (Mar 28, 2021)

skhan007 said:


> New Crack Speedball owner here! Just purchased a pre-owned unit and it arrived today! OK, so I really liking what I'm hearing so far. I do have a couple of newbie questions, if you all could be so kind:
> 
> Fist a photo...
> 
> ...


Can't comment on how yours sound or any opinion on them but for your second question, the answer is yes.  The kits come with vintage (meaning not new Chinese) tubes which will of course normally be ones you can pick up cheap and BH will have picked up batches cheaper however, sometimes people have been lucky and the "whatever we bought a batch of" has slightly better tubes.  Mine came with GE both 12AU7 and 6080.

In terms of rating mine.  When you first put it together it sounds great.  Get a mid range 12AU7 and I'll never use that GE 12AU7 again.  It gets blown away by virtually every vintage tube (budget or not) you buy on ebay.  If a Mullard CV4003 is a 10 (I'm not paying £75+ for one so never heard one) and I assume my favourite Mazdas (£15-20ish) are a 9 then the GE 12AU7 I got is a 5!!!  When I mean budget or not the Mazda is pretty cheap in the £15-£20 region but have spent up to £40 on a 12 AU7 yet the Mazda is my favourite that I own.  I have about 15 12AU7 variants that have ranged between £15 and £40.  They are all better than the stock GE that came with the kit but 2/3 only marginally better.

The GE6080 that came with the kit is a different scenario.  It isn't that bad really.  Compare to a Tung Sol 5998 of course it is nowhere near but if I had never got the 5998 I could have lived with it.  I do have a few more 6080 options but I got the 5998s early and haven't tried the others. lol.

Like I say, out of the box with the stock tubes you will like it.  It will sound good.  Buying a few cheap vintage options you will improve things unless you get really unlucky.  What you thought sounded really good will suddenly sound amazing and each time you find a tube that sounds better that "good" seems worse when in reality the "good" is just that.  The stock is pretty good out of the box.

RCA cables I can't help you with.  I made my own with some Van Damme OFC interconnect cable and Neutriks.  I like them sticking up rather than angled.

So on your tubes first thing I would do is replace the 12AU7 with something affordable just so you can hear that difference.  I find the 12AU7 changes the tone of the sound.  The 6080 makes changes to the soundstage, depth and heft of the sound.


----------



## skhan007

GreenNeedle said:


> Can't comment on how yours sound or any opinion on them but for your second question, the answer is yes.  The kits come with vintage (meaning not new Chinese) tubes which will of course normally be ones you can pick up cheap and BH will have picked up batches cheaper however, sometimes people have been lucky and the "whatever we bought a batch of" has slightly better tubes.  Mine came with GE both 12AU7 and 6080.
> 
> In terms of rating mine.  When you first put it together it sounds great.  Get a mid range 12AU7 and I'll never use that GE 12AU7 again.  It gets blown away by virtually every vintage tube (budget or not) you buy on ebay.  If a Mullard CV4003 is a 10 (I'm not paying £75+ for one so never heard one) and I assume my favourite Mazdas (£15-20ish) are a 9 then the GE 12AU7 I got is a 5!!!  When I mean budget or not the Mazda is pretty cheap in the £15-£20 region but have spent up to £40 on a 12 AU7 yet the Mazda is my favourite that I own.  I have about 15 12AU7 variants that have ranged between £15 and £40.  They are all better than the stock GE that came with the kit but 2/3 only marginally better.
> 
> ...


Thanks- I do have a great appreciation for Mullard as I use them as much as possible in my guitar amps. The 12AX7 are brilliant as first and second gain stages and Mullard EL34 tubes (XF2 variety) are among the most coveted and I'm glad to have acquired many over the years. It sounds like the 12AU7 Mullard is held in similar regard, so I may pick one up. Curious if there's a particular variant to seek out, such as long plate, black plate, halo getter, Blackburn factory, etc.? Not even sure if these variants exist on the Mullard 12AU7. 

It also sounds like the 5998 is king of the mountain. Now, in my other tube amps, the preamp tubes have the most impact on sound and the power tubes have much less. Not sure if that's the case with the BHC, as we only have the two tubes. I assume much more synergy between the two, especially since there's no output transformer. 

I've dug through my stash and found among 100 tubes, sadly only two that could be used in the BHC. Pictured below are an old Philco 12AU7 (which I've just tried and doesn't sound all that great. Not as good as the stock GE. Probably fine for a guitar amp, however) and a (I think) newer production Sovtek 6SN7. I do have a pair of 50's RCA 6SN7 currently in use in my Alessandro guitar amp. I could test drive those if I get the adapter for the BHC.


----------



## Bonddam

I'm come to the conclusion that that BH is better with Bendix 6080 and rca clear tops. It's more of a euphoric sound. The WA2 has a good sound but not euphoric like the Crack. I'm even running TOTL tubes in WA2. Looks would make you think the WA2 would perform better. I might let the WA2 go. There's no point in having WA33 and WA2 as they give same type of sound signature.


----------



## haasaaroni

Bonddam said:


> I'm come to the conclusion that that BH is better with Bendix 6080 and rca clear tops. It's more of a euphoric sound. The WA2 has a good sound but not euphoric like the Crack. I'm even running TOTL tubes in WA2. Looks would make you think the WA2 would perform better. I might let the WA2 go. There's no point in having WA33 and WA2 as they give same type of sound signature.


Man, that’s so crazy to me. I’m letting my WA6-SE go, because I don’t really have any headphones that benefit from the lower output impedance, but I always considered the WA2 a dream to have for the 300 ohm stuff...it just couldn’t ever fit it my desk  Good to know you find the Crack a more euphoric experience, I’m enjoying mine immensely.


----------



## Bonddam

haasaaroni said:


> Man, that’s so crazy to me. I’m letting my WA6-SE go, because I don’t really have any headphones that benefit from the lower output impedance, but I always considered the WA2 a dream to have for the 300 ohm stuff...it just couldn’t ever fit it my desk  Good to know you find the Crack a more euphoric experience, I’m enjoying mine immensely.


Yeah don't get me wrong WA2 is a solid OTL I'll take it over the Euforia any day of the week. My tubes for wa2 are Tung Sol 5998 Amperex 6922 and mullard EZ 80. The sound is all there. Making the choice to sell it difficult.


----------



## haasaaroni

Bonddam said:


> Yeah don't get me wrong WA2 is a solid OTL I'll take it over the Euforia any day of the week. My tubes for wa2 are Tung Sol 5998 Amperex 6922 and mullard EZ 80. The sound is all there. Making the choice to sell it difficult.


Sounds like a killer setup. Those tubes are definitely not easy to come by!


----------



## Bonddam

They are when you buy from Woo Audio they have the Tung Sol 7236 in stock in matched pairs and 5998's but you pay the premium to get them with warranty of 30 days. I think I just got screwed on eBay for some tubes that hum. So I would rathe pay that premium from now on.


----------



## jonathan c

Bonddam said:


> I'm come to the conclusion that that BH is better with Bendix 6080 and rca clear tops. It's more of a euphoric sound. The WA2 has a good sound but not euphoric like the Crack. I'm even running TOTL tubes in WA2. Looks would make you think the WA2 would perform better. I might let the WA2 go. There's no point in having WA33 and WA2 as they give same type of sound signature.


I can only guess that, in some way, the rectifier tubes for the WA2 (puzzling since the OTL WA3 has none) are a limiting factor in euphoria, energy, and “thereness”.


----------



## Bonddam

jonathan c said:


> I can only guess that, in some way, the rectifier tubes for the WA2 (puzzling since the OTL WA3 has none) are a limiting factor in euphoria, energy, and “thereness”.


Ownded both Euforias and now that I have the crack and WA2 the Euforia is overpriced. The only benefit is it's ability to play lower impedance cans.


----------



## skhan007

Quick tube follow up and seeking advice:

I've got stock tubes currently (GE 12au7 and Philips 6080) and I think I'm pretty clear on the benefits of swapping my 12au7 for Telefunken, Mullard, or clear top RCA. 

1) Who is happy with the adapter/6sn7 route? Notable improvement over a really good 12au7?

2) Regarding the swap of the stock 6080: Option 1. Tung Sol 6080, which I'm told is great. Option 2. Big bottle Tung Sol 5998 (I'm afraid I can't afford it, however) or maybe the RCA 6as7g or Svetlana winged C as a poor man's alternative? Thoughts are greatly appreciated. Help a rookie out!!

Thank you in advance.


----------



## PsilocybinCube

skhan007 said:


> Quick tube follow up and seeking advice:
> 
> I've got stock tubes currently (GE 12au7 and Philips 6080) and I think I'm pretty clear on the benefits of swapping my 12au7 for Telefunken, Mullard, or clear top RCA.
> 
> ...


Winged C is probably the best starting point and a good tube to keep around in case you are having an issue with whatever else you buy.

My BHC is having hum issues with every 5998 I throw at it.  Currently using a TS 6080 that's great.  I bought 3 of them for $60 not so long ago, but they appear to have gone up in price.

And yes, the 6sn7 is great, and it's a deep rabbit hole.  I like it better than the 12au7 but I've never tried a TOTL 12au7.


----------



## Bonddam

RCA 6as7g is very good for the price lots of good low end and midrange and good top end.


----------



## Bonddam

Is the adapter the only thing that has to be installed with 6sn7? I was thinking there might need something done on the internals but I don’t know. Why is the 6sn7 attractive over 12au7? I splurged on Amperex bugle boy 12AU7/ECC82 long plate D foil getter.


----------



## skhan007

Nope, if you get the right kind of adapter you're good- A guy on Ebay, Garage1217 is the seller, makes these specifically for the BHC. No internal changes needed.

The tonal benefit of the 6sn7? I have no idea. I have a few that I use on a guitar amp and they are much cleaner in the preamp stage than amps that use 12ax7/12at7 etc. 9-pin dual triodes. I think the bigger octal nature of the 6sn7 is headroom enhancing, but others can chime in, as my experience in tube hifi is not nearly as extensive compared to guitar amps.


----------



## hikaru12 (Mar 29, 2021)

Really enjoying my Crack at first listen. This is what my Eikons needed to wake up, totally blows away the LP I had them on before. The mid detail is excellent and the bass is quite nice. Very easy but fun listen. I can't wait to get my Aeolus to pair with it. RCA Grey glass might be my next runner up for driver tube.


----------



## Bonddam

Any 6sn7 recommendations? I just purchased the adapter so I might as well pick up a tube or 2. eBay has too many choices. $10-$50 I'll invest in one tube.


----------



## PsilocybinCube

Bonddam said:


> Any 6sn7 recommendations? I just purchased the adapter so I might as well pick up a tube or 2. eBay has too many choices. $10-$50 I'll invest in one tube.


At that price point I would recommend a westinghouse reliatron or clear glass ken-rad.


----------



## jonathan c

Bonddam said:


> Any 6sn7 recommendations? I just purchased the adapter so I might as well pick up a tube or 2. eBay has too many choices. $10-$50 I'll invest in one tube.


If you are willing to try “new production” tubes, I suggest the Tung-Sol 6SN7GTB. From Upscale Audio, in the ‘Kevin’s Stash’ (best) category the price is $39.95 per tube. Lower prices for lower categories. I use these (w/cryo treatment) in Woo WA6 - an excellent “all-rounder”. To my ears, a very large percent of what a CBS/Hytron has to offer.


----------



## skhan007

jonathan c said:


> If you are willing to try “new production” tubes, I suggest the Tung-Sol 6SN7GTB. From Upscale Audio, in the ‘Kevin’s Stash’ (best) category the price is $39.95 per tube. Lower prices for lower categories. I use these (w/cryo treatment) in Woo WA6 - an excellent “all-rounder”. To my ears, a very large percent of what a CBS/Hytron has to offer.


Just curious- What do the 6sn7 tubes offer above or differently than the 12au7? Rookie question, I know, but genuinely interested.


----------



## Bonddam

I bought over my budget and got Psvane cv181t had these in Euforia and really liked them.


----------



## jonathan c

skhan007 said:


> Just curious- What do the 6sn7 tubes offer above or differently than the 12au7? Rookie question, I know, but genuinely interested.


Here is an interesting article about the appearance and evolution of the 6SN7 and the 12AU7:  http://www.hifi-tunes.com/the-evolution-of-a-constant-glow-in-high-fidelity/


----------



## Bonddam

I went to 6sn7 thread and believe cv181 will blow my transformer as it draws too much. Does anyone know which types of 6sn7 are fine to use?


----------



## Tom-s

Crack has a 3.5A heater winding.

CV181 (the original Mullard) consumes 0.9A heater current.
6080 consumes 2.5A heater current.

In my experience with this combination. It's fine. 
A Tung Sol 5998 or WE 421A consumes 2.4A heater current; to get some extra headroom.

I've even tried BL63 (1.3A) with less consuming output tubes like a dual pair A2293 / CV4079


----------



## Bonddam

Tom-s said:


> Crack has a 3.5A heater winding.
> 
> CV181 (the original Mullard) consumes 0.9A heater current.
> 6080 consumes 2.5A heater current.
> ...


I just got worried after reading post one on 6sn7 thread about cv181 frying transformer.

Does the crack auto bias because I can’t see any pot to adjust it?


----------



## Bonddam

Here’s Psvane cv181 t 2 ratings I’m not familiar with matching things tube related.


Heater
UH………… 6.3 V
IH ………… 0.6 A

Static Parameter
Ua ………………………… 90 250 V
Ug………………………… 0 -8V
Ia ………………………… 10 9 mA
Gm………………………… 3 2.6 mA/V
Ri ………………………… 6.7 7.7 kΩ
μ ………………………… 20 20
Ia when Ug=-12.5V _ 1.3mA
Ug whenIa=-10uA – 7 -18V
Maximum Rating
class A1
Ua………………………… 450V
Ik………………………… -20mA
Pa ………………………… 5w
Pa(No.1+No2) ………… 7w
Rg ……………… 1MΩ
Uhk ………………±100V

I will be using different power tubes mainly gh13c and 6as7g.


----------



## GreenNeedle (Mar 31, 2021)

skhan007 said:


> Thanks- I do have a great appreciation for Mullard as I use them as much as possible in my guitar amps. The 12AX7 are brilliant as first and second gain stages and Mullard EL34 tubes (XF2 variety) are among the most coveted and I'm glad to have acquired many over the years. It sounds like the 12AU7 Mullard is held in similar regard, so I may pick one up. Curious if there's a particular variant to seek out, such as long plate, black plate, halo getter, Blackburn factory, etc.? Not even sure if these variants exist on the Mullard 12AU7.
> 
> It also sounds like the 5998 is king of the mountain. Now, in my other tube amps, the preamp tubes have the most impact on sound and the power tubes have much less. Not sure if that's the case with the BHC, as we only have the two tubes. I assume much more synergy between the two, especially since there's no output transformer.
> 
> I've dug through my stash and found among 100 tubes, sadly only two that could be used in the BHC. Pictured below are an old Philco 12AU7 (which I've just tried and doesn't sound all that great. Not as good as the stock GE. Probably fine for a guitar amp, however) and a (I think) newer production Sovtek 6SN7. I do have a pair of 50's RCA 6SN7 currently in use in my Alessandro guitar amp. I could test drive those if I get the adapter for the BHC.


You should note that Mullard 12AU7/ECC82 is not the same as a Mullard CV4003.  The Mullard CV4003 is a very sought after tube and will cost you £75+ (testing good NOS) unless you find a bargain.  A Mullard 12AU7 ( I do have one) will be in the £20-£30 region and I rated it a 6 so is one of the marginally better than the GE ones I have.  This is of course my opinion and others here do rate it though.  It does suffer from the name because sellers mention CV4003 in the listings for this tube and thus it often commands a premium above where (I feel) it should be.

Poster above on the 6SN7.  I do feel that it gives a little extra than the 12AU7 (from the tubes I have tested) but it isn't a vast improvement over my favourite 12AU7(s.)  A little bit more grunt and bite maybe?  Possibly placebo.


----------



## Bonddam

So after a week the sound of my overbuilt Crack is more enjoyable then WA2. It comes down to dynamics. The WA2 never keeps me engaged with the music. So the WA2 must go. Hope it goes as it comes with a ton of tubes.


----------



## hikaru12

Bonddam said:


> So after a week the sound of my overbuilt Crack is more enjoyable then WA2. It comes down to dynamics. The WA2 never keeps me engaged with the music. So the WA2 must go. Hope it goes as it comes with a ton of tubes.



I'll take any 6080s - I've been looking for a Bendix 6080WB for a while.


----------



## skhan007

GreenNeedle said:


> You should note that Mullard 12AU7/ECC82 is not the same as a Mullard CV4003.  The Mullard CV4003 is a very sought after tube and will cost you £75+ (testing good NOS) unless you find a bargain.  A Mullard 12AU7 ( I do have one) will be in the £20-£30 region and I rated it a 6 so is one of the marginally better than the GE ones I have.  This is of course my opinion and others here do rate it though.  It does suffer from the name because sellers mention CV4003 in the listings for this tube and thus it often commands a premium above where (I feel) it should be.
> 
> Poster above on the 6SN7.  I do feel that it gives a little extra than the 12AU7 (from the tubes I have tested) but it isn't a vast improvement over my favourite 12AU7(s.)  A little bit more grunt and bite maybe?  Possibly placebo.


Good to know, regarding the Mullard’s. When you rated the ecc82 a 6, does this mean that you posted a hierarchy or ratings for different 12au7 tubes? I’d be interested to see this, if so.


----------



## Bonddam

I guess somebody is hoarding all the Bendix 6080


----------



## GreenNeedle (Apr 1, 2021)

skhan007 said:


> Good to know, regarding the Mullard’s. When you rated the ecc82 a 6, does this mean that you posted a hierarchy or ratings for different 12au7 tubes? I’d be interested to see this, if so.



I did but I have a ton more to add to it as I stopped being so banal. lol.  My notes cover the first 8 variants I bought.  I have probably another 5 or more that I have obught since and only given a few minutes each to so far.

Should also be noted that these things are subjective.  Our ears prefer different blends.  Many people do like the Mullard.  For testing I used the same CDs, source and songs.  I did initial impressions which were short notes and then a fuller note appraisal.  I may have been a little hard on this tube.

This is what I did.  Feel free to chuckle at my initial over enthusiasm before thinking "can't be bothered."  Sad when you are doing a TLDR to yourself.  Prices were all including shipping.


----------



## DenverW

Bonddam said:


> So after a week the sound of my overbuilt Crack is more enjoyable then WA2. It comes down to dynamics. The WA2 never keeps me engaged with the music. So the WA2 must go. Hope it goes as it comes with a ton of tubes.



Lucious tube sound for the win.

On a side note, the crackatwoa monster is up and running.  I wanted to run it one night with stock tubes to get an idea of the change when I put in some real quality ones...and that idea lasted about 20 minutes.  Initial thoughts on the first night:  really, really good instrument separation and clarity.


----------



## Tom-s

Bonddam said:


> Here’s Psvane cv181 t 2 ratings I’m not familiar with matching things tube related.
> 
> 
> Heater
> ...



The Psvane CV181 is not a Mullard CV181. Electrically the Psvane is a 6SN7 and the Mullard is not.
http://www.r-type.org/exhib/aad0139.htm
So with the Psvane it will function exactly the same as any other 6SN7. No problems with any 6SN7 amplifier.
The Mullard is electrically not a 6SN7 whatever others want you to believe. It will bias differently, consume more 0,35A heater current and potentially could fry a transformer when not build for it's use.


----------



## cddc

Tom-s said:


> The Psvane CV181 is not a Mullard CV181. Electrically the Psvane is a 6SN7 and the Mullard is not.
> http://www.r-type.org/exhib/aad0139.htm
> So with the Psvane it will function exactly the same as any other 6SN7. No problems with any 6SN7 amplifier.
> The Mullard is electrically not a 6SN7 whatever others want you to believe. It will bias differently, consume more 0,35A heater current and potentially could fry a transformer when not build for it's use.



Agree, lots of people take Mullard CV181 / ECC32 as a 6SN7 direct replacement, but it is really NOT. CV181 / ECC32 takes 0.95A heater current which is 150+% higher than 6SN7, it can fry some transformers if there is not enough redundancy in design. 

Also, the gain of ECC32 is 32 (vs gain of 20 from 6SN7), which makes it more a 6922/6DJ8/ECC88 (gain of 33) replacement. With gain 165% higher, I suspect replacing a 6SN7 with ECC32 will overdrive the power tube grid.


----------



## cddc

DenverW said:


> Lucious tube sound for the win.
> 
> On a side note, the crackatwoa monster is up and running.  I wanted to run it one night with stock tubes to get an idea of the change when I put in some real quality ones...and that idea lasted about 20 minutes.  Initial thoughts on the first night:  really, really good instrument separation and clarity.



Glad to hear you finally got your Cracka2a up and running, seems to be a really tough project.

Hope you didn't forget how a Crack w/ Speedball sounds, and let's know their differences.


----------



## Bonddam

Tom-s said:


> The Psvane CV181 is not a Mullard CV181. Electrically the Psvane is a 6SN7 and the Mullard is not.
> http://www.r-type.org/exhib/aad0139.htm
> So with the Psvane it will function exactly the same as any other 6SN7. No problems with any 6SN7 amplifier.
> The Mullard is electrically not a 6SN7 whatever others want you to believe. It will bias differently, consume more 0,35A heater current and potentially could fry a transformer when not build for it's use.


If usps deliver my stuff this weekend I will report back.


----------



## attmci (Apr 2, 2021)

cddc said:


> Agree, lots of people take Mullard CV181 / ECC32 as a 6SN7 direct replacement, but it is really NOT. CV181 / ECC32 takes 0.95A heater current which is 150+% higher than 6SN7, it can fry some transformers if there is not enough redundancy in design.
> 
> Also, the gain of ECC32 is 32 (vs gain of 20 from 6SN7), which makes it more a 6922/6DJ8/ECC88 (gain of 33) replacement. With gain 165% higher, I suspect replacing a 6SN7 with ECC32 will overdrive the power tube grid.


I believe the ECC32 is very expensive. No?


----------



## YtseJamer (Apr 2, 2021)

Morning guys,

I just bought a Crack with the Speedball but I'm looking for tubes recommendations.  I will use the amp with the ZMF Verite Closed/Aeolus and my DAC is the Bifrost 2.

The seller told me that the amp is coming with the stock input tube, but the power tube was upgraded to the famous electro harmonix that everyone uses.

I don't want to go down the tubes rabbit hole (been there, done that..) and my goal is simply to bring the amp to the next level with some 'affordable' tubes.  Affordable = $50/75$ CAD per tube 

Thanks in advance


----------



## Bonddam

YtseJamer said:


> Morning guys,
> 
> I just bought a Crack with the Speedball but I'm looking for tubes recommendations.  I will use the amp with the ZMF Verite Closed/Aeolus and my DAC is the Bifrost 2.
> 
> ...


Crack is fun when rabbit hole opens. I said the same thing now I bought more tubes and 6sn7 tubes plus adapter.


----------



## YtseJamer

Bonddam said:


> Crack is fun when rabbit hole opens. I said the same thing now I bought more tubes and 6sn7 tubes plus adapter.



Hahaha, I just don't want to end up spending more money on the tubes than the actual amp


----------



## GreenNeedle

YtseJamer said:


> Hahaha, I just don't want to end up spending more money on the tubes than the actual amp


Dependent on how much you paid for the amp, that is impossible. lol.


----------



## YtseJamer

GreenNeedle said:


> Dependent on how much you paid for the amp, that is impossible. lol.



Hahaha, I paid $600 CAD.


----------



## skhan007

YtseJamer said:


> Hahaha, I just don't want to end up spending more money on the tubes than the actual amp


Hey, new BHC Speedball owner here! Got mine a week ago and I'm circling the rabbit hole with a safety harness on. I have started to research, explore, correspond with the kind and  knowledgeable members here and I'm learning a lot. That being said, I'm looking at various lower priced 12AU7 tubes, as I'm told virtually anything would be better than the stock GE preamp tube that came with mine. The power tube with mine is also quite Meh by most standards, so I may have some nice vintage/NOS ones to swap in very soon. That being said, it's quite likely that if you want to make a single purchase of pre- and power- tubes, you'll find some good deals if you look around and try to be patient. Listen to your stock tubes and note what you'd like to improve upon. Read the last 3-4 pages of this thread, as there's good talk about synergy, starting with some decent mid-priced tubes, and building from there if needed.


----------



## Bonddam

I spent more on accessories then then I paid for the amp. Mine was fully loaded close to 700.


----------



## GreenNeedle (Apr 2, 2021)

YtseJamer said:


> Hahaha, I paid $600 CAD.


When I first started researching and actually ordered the Crack kit I stated I was looking for a single pair of improvement tubes and wasn't going to spend much more.  Jus a one stop....................how wrong was I 

That said you can easily buy loads of tubes over time and just keep a handful that you get on with.  You will get virtually all your money back and over time the vintage tube prices do go up because of course there will be less and less of them as years go by.  Buy sensibly with patience and the ones you don't want to keep just put on a buyitnow at the same price you paid including postage + new postage and someone will buy them.

Should also add that prices are different in different countries.  US made tubes tend to be much cheaper in the US and vice versa for Europe.  My "cheap tubes" might cost a bit more in the US and that's if you can find them.  US made tubes the same over here.  So my talk of a £20 tube ($28ish) might cost $40 in the US and your $20 tube might cost me £40 her in the UK.


----------



## DenverW

YtseJamer said:


> Hahaha, I just don't want to end up spending more money on the tubes than the actual amp



So we shouldn’t talk about upgrading the caps, pot, or choke right now?  
Don’t worry, we’ll be here...

For reasonable tubes look for rca coke bottle 6as7g and Siemens chrome plate 12au7.


----------



## YtseJamer

DenverW said:


> So we shouldn’t talk about upgrading the caps, pot, or choke right now?
> Don’t worry, we’ll be here...
> 
> For reasonable tubes look for rca coke bottle 6as7g and Siemens chrome plate 12au7.



Haha, no not yet.  I also ordered the SW51+, but if I prefer the BHC I will probably upgrade the caps later.

I'm very close to pull the trigger on the Tung Sol 5998.  Do you think the Westinghouse 12AU7 would be a good match with the TS 5998?

Thanks for your feedback.


----------



## hikaru12

Bonddam said:


> I spent more on accessories then then I paid for the amp. Mine was fully loaded close to 700.



Same here I'm about at $800 on BHC.


----------



## DenverW (Apr 2, 2021)

YtseJamer said:


> Haha, no not yet.  I also ordered the SW51+, but if I prefer the BHC I will probably upgrade the caps later.
> 
> I'm very close to pull the trigger on the Tung Sol 5998.  Do you think the Westinghouse 12AU7 would be a good match with the TS 5998?
> 
> Thanks for your feedback.



Beware of bright with bright.  The Westinghouse especially I found a bright tube.

edit: 5998 isn’t so much bright as...clear.  Still not a combo I would recommend.


----------



## cddc (Apr 3, 2021)

attmci said:


> I believe the ECC32 is very expensive. No?



No, it's actually crazy expensive . It's actually the reason why it successfully caught my attention in the first place.

I don't know who pushed up its price, maybe those crazy 6DJ8/6922/ECC88/E188CC users (some premium versions of this ECC88 family tubes can fetch $300-$500+), maybe some Mullard hoarders, or less likely some unwise 6SN7 users.

Then I looked into the ECC32 specs. First thing I noticed was the 0.95A heater current - it's pretty high, actually might be too high for lots of 6SN7 amps, but luckily Crack still has the extra capacity to run it.

But then I noticed its gain of 32, and it immediately turned me off.   With a gain of 32, it's actually a 6DJ8/6922/ECC88/E188CC (gain of 33) replacement rather than a 6SN7 replacement (gain of 20).

And I don't like the idea of sticking a 6DJ8/6922/ECC88/E188CC tube or its replacement (ECC32) into the 6SN7 driver socket. 6SN7 amplifies the input signal 20 times, but ECC32 amplifies it 32 times, and this might overheat the power tube, and also might overdrive the power tube grid (which could lead to clipping - chop the peaks off a sine wave and turn it into some square-ish wave). If you're interested in hearing the "overdrive" distortion, here is a video for you:


----------



## skhan007

Based on a lot of suggestions, I picked up two RCA 12AU7 clear tops. The immediate difference over the stock GE (which many have stated, anything would be better) is that it sounds like a blanket has been lifted off the midrange and highs, which suddenly sound more "alive" and crisp. Very noteworthy difference there. Bass doesn't sound much different, but perhaps a tiny bit more clearly defined. This was a very low-cost upgrade and I'm pleased! Now, onto the driver tubes later this week.


----------



## Bonddam

Got some Tung Sol 7236 and currently using RCA 12au7 clear top and the sound is amazing so detailed. waiting for tomorrow when I can swap out the 12au7 and test psvane cv181t mk2 along with the 7236. The 7236 I got are not the military spec units. I can't hear a difference.


----------



## RedJohn456

I have been interested in the Crack for awhile after briefly auditioning 4 years ago. Really close to picking up a used BHC + speedball combo but wondering if it would be better to get the crackatwoa?


----------



## DenverW

RedJohn456 said:


> I have been interested in the Crack for awhile after briefly auditioning 4 years ago. Really close to picking up a used BHC + speedball combo but wondering if it would be better to get the crackatwoa?



I couldn't find a crackatwoa so eventually built my own.  It is a pretty decent upgrade over the crack.  If you have the opportunity to build a crack vs. buy one, I 100% recommend building it.  Unless you're already experienced the knowledged gained is invaluable.  For example, long, long ago I bought a crack.  When it stopped working I had to take it to a shop and it took them three months to fix it.  It was a blown fuse.  Thats it.

Then I built a crack.  While upgrading I had some channel issues.  Because I had built the amp I was able to trace the problem and fix it.  Made a huuuuuuge difference.  Besides, upgrading the crack is fun as all get out.


----------



## RedJohn456 (Apr 4, 2021)

DenverW said:


> I couldn't find a crackatwoa so eventually built my own.  It is a pretty decent upgrade over the crack.  If you have the opportunity to build a crack vs. buy one, I 100% recommend building it.  Unless you're already experienced the knowledged gained is invaluable.  For example, long, long ago I bought a crack.  When it stopped working I had to take it to a shop and it took them three months to fix it.  It was a blown fuse.  Thats it.
> 
> Then I built a crack.  While upgrading I had some channel issues.  Because I had built the amp I was able to trace the problem and fix it.  Made a huuuuuuge difference.  Besides, upgrading the crack is fun as all get out.



That's a fair point, I am also quite deep into mechanical keyboards and so I am no stranger to soldering and desoldering (I have a lot of tools as a result) and am quite handy in that regard. It is literally cheaper for me to buy a 2nd hand upgraded BHC versus ordering it new and importing into Canada.

Edit: typo


----------



## PsilocybinCube

YtseJamer said:


> Morning guys,
> 
> I just bought a Crack with the Speedball but I'm looking for tubes recommendations.  I will use the amp with the ZMF Verite Closed/Aeolus and my DAC is the Bifrost 2.
> 
> ...


I like the Chatham 6as7g with all Zmf headphones.  There is good synergy with their headphone tuning.

I pair mine with a Brimar 12bh7.


----------



## DenverW

RedJohn456 said:


> That's a fair point, I am also quite deep into mechanical keyboards and so I am no stranger to soldering and desoldering (I have a lot of tools as a result) and am quite handy in that regard. It is literally cheaper for me to buy a 2nd hand upgraded BHC + upgrade versus ordering it new and importing into Canada.



Then grab a crackatwoa if you can locate one!


----------



## RedJohn456

DenverW said:


> Then grab a crackatwoa if you can locate one!


Sadly not so easy in Canada but I might jsut have to get a fresh Kit in that case


----------



## DenverW

RedJohn456 said:


> Sadly not so easy in Canada but I might jsut have to get a fresh Kit in that case



Crackatwoa was not an easy build.  It was a lot more challenging than the crack.


----------



## skhan007

New Tubes Day! Based on recommendations and reading many entries on this thread, I have acquired some new power tubes to accompany my recently acquired RCA clear top 12AU7 driver tubes.

Just delivered and soon to be test driven are a matched pair of Chatham 6AS7G (even though I only need one, they were sold in a pair) and a single Bendix 6080, all testing at NOS. Really looking forward to seeing if I can hear the difference from the stock BHC Philips driver tube. I'm hopeful I'll hear an appreciable difference, as I did when I subbed in the RCA clear top in place of the stock GE.


----------



## raindownthunda

skhan007 said:


> New Tubes Day! Based on recommendations and reading many entries on this thread, I have acquired some new power tubes to accompany my recently acquired RCA clear top 12AU7 driver tubes.
> 
> Just delivered and soon to be test driven are a matched pair of Chatham 6AS7G (even though I only need one, they were sold in a pair) and a single Bendix 6080, all testing at NOS. Really looking forward to seeing if I can hear the difference from the stock BHC Philips driver tube. I'm hopeful I'll hear an appreciable difference, as I did when I subbed in the RCA clear top in place of the stock GE.



Very nice. Let us know what you think!


----------



## cebuboy

skhan007 said:


> New Tubes Day! Based on recommendations and reading many entries on this thread, I have acquired some new power tubes to accompany my recently acquired RCA clear top 12AU7 driver tubes.
> 
> Just delivered and soon to be test driven are a matched pair of Chatham 6AS7G (even though I only need one, they were sold in a pair) and a single Bendix 6080, all testing at NOS. Really looking forward to seeing if I can hear the difference from the stock BHC Philips driver tube. I'm hopeful I'll hear an appreciable difference, as I did when I subbed in the RCA clear top in place of the stock GE.


Nice score on the Bendix, that is really hard to find. Do let us know of your impressions.


----------



## DenverW

skhan007 said:


> New Tubes Day! Based on recommendations and reading many entries on this thread, I have acquired some new power tubes to accompany my recently acquired RCA clear top 12AU7 driver tubes.
> 
> Just delivered and soon to be test driven are a matched pair of Chatham 6AS7G (even though I only need one, they were sold in a pair) and a single Bendix 6080, all testing at NOS. Really looking forward to seeing if I can hear the difference from the stock BHC Philips driver tube. I'm hopeful I'll hear an appreciable difference, as I did when I subbed in the RCA clear top in place of the stock GE.



Hope you love them!  I’m also curious to hear impressions; I actually like the 6as7g more than the bendix, but I’d probably be the minority.


----------



## jonathan c

DenverW said:


> Hope you love them!  I’m also curious to hear impressions; I actually like the 6as7g more than the bendix, but I’d probably be the minority.


I have been using a Tung-Sol (made in U.S.) JAN-CAHG-6AS7G in my Woo Audio WA3 to great musical satisfaction. I prefer this power tube to (m)any of the 6080s that I have tried in the WA3. The 6080s were not disappointing, the TS 6AS7G just stood taller - physically and sonically.


----------



## Bonddam

Here's real good 12au7 that cost a pretty penny. I got two off eBay. I tried Psvane cv181 tube but don't recommend it as it is noisey and through a pop through my VC so now ZMF is replacing the driver for me.


----------



## OceanRanger

Bonddam said:


> Here's real good 12au7 that cost a pretty penny. I got two off eBay. I tried Psvane cv181 tube but don't recommend it as it is noisey and through a pop through my VC so now ZMF is replacing the driver for me.


wow, that just looks awesome. My solid state amp definitely falls short on that coolness factor. Or perhaps I should say that warmness factor.


----------



## DenverW

You guys with your tube porn!  Makes me want to post pictures....crackatwoa with brimar el90, the oldest of amperex welded plate 12au7, and some gec power tube with an ugly brown base.


----------



## skhan007

I've spent a few days doing A/B testing with my recently acquired Chatham 6AS7G vs. Bendix 6080.

They sound similar to my ears overall, with the Bendix having more definition in the mids, especially vocals, and the high frequencies. My RME DAC has an PEQ, so if I were to make some very slight EQ adjustments and raise the midrange and highs a dB or two, they are very close. Both are excellent and have great presence in the low end frequencies. I wish I could A/B quickly, but I have to power down, allow the current tube to cool for a few minutes, put in the other and allow it to warm up. That being said, I believe the Bendix has a wider soundstage and separation, where the Chatham is slightly more focused sounding. 

My next stop will be the GEC 6080, as I've heard great things and I'm eager to see if that is on-par or perhaps better in any way to what I've currently got.

I was interested in the 5998, but I've been using the search function on this thread and the 6AS7G tube roller thread and noted a lot of mixed reviews. Some guys state it's their favorite in the BHC, while others stated they become unstable/microphonic, no difference is sound to Tung Sol Chatham 6AS7G, or simply too pricey. I know there's no consensus (there rarely is among tube rollers, from what I'm reading), but my main question would be how people would see the Tung Sol 5998 vs. Chatham 6AS7G in terms of overall sound.


----------



## Bonddam

skhan007 said:


> I've spent a few days doing A/B testing with my recently acquired Chatham 6AS7G vs. Bendix 6080.
> 
> They sound similar to my ears overall, with the Bendix having more definition in the mids, especially vocals, and the high frequencies. My RME DAC has an PEQ, so if I were to make some very slight EQ adjustments and raise the midrange and highs a dB or two, they are very close. Both are excellent and have great presence in the low end frequencies. I wish I could A/B quickly, but I have to power down, allow the current tube to cool for a few minutes, put in the other and allow it to warm up. That being said, I believe the Bendix has a wider soundstage and separation, where the Chatham is slightly more focused sounding.
> 
> ...


The only place I've been able to buy 5998 that I know are tested and matched is Woo. Price for one is $450. I like it in bhc but find 6as7g of any brand a better option. It's just cheaper route. 7236 gives a solid state experience and I got 3 for $150 bucks Woo wants $249 a unit. Difference is I have none military units total units 8. Three are metal base and 5 plastic base.


----------



## PsilocybinCube

Bonddam said:


> Here's real good 12au7 that cost a pretty penny. I got two off eBay. I tried Psvane cv181 tube but don't recommend it as it is noisey and through a pop through my VC so now ZMF is replacing the driver for me.


I had a bad 12au7 do that to an Eikon.  It's about as frustrating an experience as you can have in audio.  

It's definitely a reminder to unplug before turning on your amp!!!


----------



## Bonddam

Did a 2nd try installed first ken rad 6sn7 had hiss that got lower and lower played some music sounded real good. So went back to the cv181tmk2 psvane and powered on without headphones plugged in waited 30 seconds and a little hum in left side not loud enough to bother music playing. So not sure what I'm listening for but I'll switch back later to my Amperex 12au7 bugle boy tube and I know it's dead silent.


----------



## Bonddam

The amp gets turned on and off with no headphone connected from now on.


----------



## PsilocybinCube

Bonddam said:


> Did a 2nd try installed first ken rad 6sn7 had hiss that got lower and lower played some music sounded real good. So went back to the cv181tmk2 psvane and powered on without headphones plugged in waited 30 seconds and a little hum in left side not loud enough to bother music playing. So not sure what I'm listening for but I'll switch back later to my Amperex 12au7 bugle boy tube and I know it's dead silent.


As much as I like to pump up the 6sn7 as a preferred tube (or a pair of 6j5 tubes) in the BHC, I can't get around the fact that a 12au7 or 12bh7 has always been the most noise-free and fuss-free for me.

I don't know all the rules around the 12bh7 vs. the 12au7, I think you are supposed to have the Speedball.  I bought my BHC used from @DenverW and the only modification I've made is the woodworking.

That said, I tell you what, the 12bh7 is a hell of a tube for a small amount of money.  The TS is cheap and sounds great.  It is super punchy in it's bass, it's got a great soundstage, and good detail.  I have it paired with a Chatham 6as7g and that pairing is going great with my Verite Open.  With the ZMF Eikon I found it a bit too bright, but the VO is more warm/neutral and the combo feels just right!

The nice 12au7 tubes are approaching crazy territory (along with 6as7, 6080, 6sn7, and some 6j5 tube variants) and it's nice to find a really great alternative that isn't expensive (yet).


----------



## Bonddam

PsilocybinCube said:


> As much as I like to pump up the 6sn7 as a preferred tube (or a pair of 6j5 tubes) in the BHC, I can't get around the fact that a 12au7 or 12bh7 has always been the most noise-free and fuss-free for me.
> 
> I don't know all the rules around the 12bh7 vs. the 12au7, I think you are supposed to have the Speedball.  I bought my BHC used from @DenverW and the only modification I've made is the woodworking.
> 
> ...


I just decided to jump and test something I was nervous about. This time around the noise went away and seem to run with no issues. I’m going to buy two easy to drive speakers off partsexpress and uses it as a dummy load for testing new tubes. Just need high impedance with high sensitivity. They’ll have to be able to take loud pop’s.


----------



## skhan007

PsilocybinCube said:


> As much as I like to pump up the 6sn7 as a preferred tube (or a pair of 6j5 tubes) in the BHC, I can't get around the fact that a 12au7 or 12bh7 has always been the most noise-free and fuss-free for me.
> 
> I don't know all the rules around the 12bh7 vs. the 12au7, I think you are supposed to have the Speedball.  I bought my BHC used from @DenverW and the only modification I've made is the woodworking.
> 
> ...


Thanks for the tip on the TS 12bh7!  I was not aware that this tube existed and have only recently acquired my pair of Chatham 6AS7G. Right now, I’m using an RCA  clear top 12aU7,  based on some recommendations in this thread. Curious if the TS 12BH7 is a step up? I do have the speedball set up, as well. I was listening to my 6AS7G earlier today. Glorious sounding tube in the BHC!


----------



## DenverW

So yes, before using 6sn7, 12BH7, or e80cc tubes you want to have the speedball upgrade.

The 6sn7, 6j5, 6f8g, and the like can be used without any modifications, just adapters.

12BH7A and e80cc will benefit from some slightly different resistors to bring the currents to optimal crack levels.  You can get more Details on the Bottlehead website.

Or you could do what I keep saying I’m going to do and build a three way switch with different resistors to be able to roll all three.

I preferred the Phillips sq e80cc to the 12BH7A.


----------



## DenverW

Combo of repairs and fun tonight.  Received a bottlehead S.E.X. kit from a classified 'want to buy' I posted.  The goal was to bring it into work and have a nice mid range amp to use there with a wide variety of headphones.  I had to do some repairs on the amp when it arrived, but got it up and working.  Had it at work this week, and then it just...stopped.  Music just cut off.

Tonight I swapped out the alps pot that had been having issues before, and BOOM, its working again.  Now for the fun part.  Switched out the .1uf dayton caps with .1uf Miflex KPCU caps.  In the lower uf range these are very affordable (18 bucks from parts connection) and they are VERY good caps.  One caveat on these: the connecting wires are fairly large and will not fit on circuit board connections like the .1 caps on the mainline.  Listening on my HD800 (which is a great thing about the S.E.X. amp, it plays pretty much anything and is imho the most versatile of the bottlehead amps) the sound is clear, euphoric, and has just a tiny touch of smoothness that eliminates the dull feeling I get with some solid state amps.  (I'm looking at you, drop THX!)

If you want an amp that plays anything, including planars, and don't want to fall into the tube swapping pit (they pretty much all sound the same on the S.E.X.) this is the amp for you.


----------



## Bonddam (Apr 10, 2021)

Edit


----------



## Bonddam

Delete


----------



## cddc

DenverW said:


> Combo of repairs and fun tonight.  Received a bottlehead S.E.X. kit from a classified 'want to buy' I posted.  The goal was to bring it into work and have a nice mid range amp to use there with a wide variety of headphones.  I had to do some repairs on the amp when it arrived, but got it up and working.  Had it at work this week, and then it just...stopped.  Music just cut off.
> 
> Tonight I swapped out the alps pot that had been having issues before, and BOOM, its working again.  Now for the fun part.  Switched out the .1uf dayton caps with .1uf Miflex KPCU caps.  In the lower uf range these are very affordable (18 bucks from parts connection) and they are VERY good caps.  One caveat on these: the connecting wires are fairly large and will not fit on circuit board connections like the .1 caps on the mainline.  Listening on my HD800 (which is a great thing about the S.E.X. amp, it plays pretty much anything and is imho the most versatile of the bottlehead amps) the sound is clear, euphoric, and has just a tiny touch of smoothness that eliminates the dull feeling I get with some solid state amps.  (I'm looking at you, drop THX!)
> 
> If you want an amp that plays anything, including planars, and don't want to fall into the tube swapping pit (*they pretty much all sound the same *on the S.E.X.) this is the amp for you.



Congrats on getting and fixing a S.E.X.

So S.E.X. has the magic of making a GE tube sound like a GEC?


----------



## jonathan c

cddc said:


> Congrats on getting and fixing a S.E.X.
> 
> So S.E.X. has the magic of making a GE tube sound like a GEC?


Only when switched off 😄


----------



## skhan007

In my search for some GEC 6080 tubes, I was able to find a pair for sale. They would be shipped from the UK to the US, and I've never made an overseas purchase before and was hoping for some guidance. The tubes test NOS and only have a few hours on them.

Without import fees, I think I'm at about $275 (tubes, shipping, and PayPal fees). I'm not sure if I'm calculating import fees correctly, as I've found some on-line cost calculators and I'm uncertain if they are accurate, but I think it's another $30 or so.

Is $300 too pricey for a pair of GEC 6080 tubes? My instincts say this is too much, but I'm really not sure, as I'm still pretty new to the tube rolling process. Any input is appreciated. I've asked the same question on the 6AS7G tube rolling thread, in hopes of additional input.


----------



## DenverW

skhan007 said:


> In my search for some GEC 6080 tubes, I was able to find a pair for sale. They would be shipped from the UK to the US, and I've never made an overseas purchase before and was hoping for some guidance. The tubes test NOS and only have a few hours on them.
> 
> Without import fees, I think I'm at about $275 (tubes, shipping, and PayPal fees). I'm not sure if I'm calculating import fees correctly, as I've found some on-line cost calculators and I'm uncertain if they are accurate, but I think it's another $30 or so.
> 
> Is $300 too pricey for a pair of GEC 6080 tubes? My instincts say this is too much, but I'm really not sure, as I'm still pretty new to the tube rolling process. Any input is appreciated. I've asked the same question on the 6AS7G tube rolling thread, in hopes of additional input.



I think you’re set on these tubes, so my opinion may not be what you’re looking for.  I think overall that the 6080 style tubes lag behind the 6as7g type, and would recommend those instead.  I think the gec tubes overall are overpriced, and for that money you could be getting some totl tube Or tubes.  5998, 421a, etc.

You could get a mullard 6080 for well under $100, and I didn’t find a difference worth noting between that and the gec,  tung sol 6080 are great, but also expensive and not worth it imho at this point.  What led you to the gec 6080 tube?


----------



## skhan007

DenverW said:


> I think you’re set on these tubes, so my opinion may not be what you’re looking for.  I think overall that the 6080 style tubes lag behind the 6as7g type, and would recommend those instead.  I think the gec tubes overall are overpriced, and for that money you could be getting some totl tube Or tubes.  5998, 421a, etc.
> 
> You could get a mullard 6080 for well under $100, and I didn’t find a difference worth noting between that and the gec,  tung sol 6080 are great, but also expensive and not worth it imho at this point.  What led you to the gec 6080 tube?


Your opinion is very much appreciated. 

What led me to these tubes- A lot of really strong reviews on this thread, the 6AS7G tube rolling thread, and reviews on a different forum. I've heard a couple people stating that the GEC 6080 was to them, superior to the Bendix 6080 (which I have) and even superior to the Chatham 6AS7G (which I have and absolutely love). 

A couple of concerns that mostly come down to price: After currency conversion fees, import fees, and PayPal fees, I'm at about $150 per tube (maybe more). Also, the import fee calculators on-line are giving me very different import fee estimates. Some say $30 and some say over $100 (that seems extreme, but I've never imported goods and had to pay duties). 

If you or anyone knows rough ways to calculate the cost of importing 2 tubes from the UK to US, that would also be very much appreciated. But from what I'm hearing from you, @DenverW , perhaps I should pause and consider costs/other options.


----------



## DenverW (Apr 11, 2021)

skhan007 said:


> Your opinion is very much appreciated.
> 
> What led me to these tubes- A lot of really strong reviews on this thread, the 6AS7G tube rolling thread, and reviews on a different forum. I've heard a couple people stating that the GEC 6080 was to them, superior to the Bendix 6080 (which I have) and even superior to the Chatham 6AS7G (which I have and absolutely love).
> 
> ...



I would consider other options for sure, especially since you already have two great tubes.  Honestly, two VERY solid tubes.  For me, tube rolling is something I have to control myself on.  I want to try EVERYTHING!  But the reality is that most tubes would just end up sitting on a shelf or being resold because there are only two tubs in the crack at any given time. 

So after trying pretty much everything, I limit myself.  I try to follow a few rules.  I try not to buy multiples of a particular tube, especially if I havent heard it, because matched pairs can cost more than buying individually, and because one of the two isn't getting used.  There is a temptation to have a 'spare' but these tubes last a pretty long time, and unless it becomes my favorite I don't need a spare.  So basically I try not to buy tubes now unless I think there is a legitimate chance it will replace a current favorite, or at least add a different enough sound that I can justify having it.

Also, with the crack, do you really want tubes that cost as much or more than the kit itself?  A crackatwoa with stock tubes will sound better than a crack with great tubes based on components and design.  At $300 plus for those tubes you're pretty much at crackatwoa levels, and you can keep all your current crack tubes to use with it.  This is what I did.  I've had and built a couple cracks, modded them to death, then I sold them and used the money for a crackatwoa. 

So here is what I think.  If you're looking at the gec6080, I would look for a single tube that is reasonable.  If you're open to other power tubes that I think are much better, I would find a single tung sol 5998, a western electric 421A, or a GEC 6AS7G.  Imho, those are the top three power tubes in the crack, and I find them better than any 6080 variant.  They cost a pretty penny, though, so be patient.  Eventually one is sold in the more reasonable price range.  $150 for the 5998 and $300 or less for the other two are 'reasonable' in today's prices.  I honestly wouldn't get one unless this is your forever amp, or if you're going the crackatwoa route one day.

Next, (or first!) I would explore the fun of input tube variants.  You have the speedball, right?  You can run some fun, fun tubes with an adapter.  The favorite is the 6sn7 (not a driver tube although it is the same socket, don't get confused! It needs a 6sn7 -> 12au7 adapter!).  Many crazy people who don't know better (hahah I couldn't resist!) prefer these to 12au7 tubes.  Problem is, the price is going high.  My favorite is the cv6 or e1148 tubes.  These are half of a 12au7/6sn7 each, so with an adapter it turns the crack into the 'frankencrack!'.  Others like the 6j5, 6f8g, or others.  Basically, you can have fun for lower prices by rolling tube variants that arent as popular in amps as the 12au7 and 6sn7.  Just make sure you have the right info and don't pop anything in that will hurt the amp.

So sorry for the long reply, hope it didn't bore you!  We're all here to help and offer opinions (thats all they are!) so feel free to ask 

Edit: I had accidentally identified the WE 421a as a GE 421a.  Theres a nasty typo, for sure!  Avoid GE tubes


----------



## wabibito

I recently bought an unbuilt crack 1.0 with speedball.  Does anyone knows performance wise is it the same as 1.1?  I know that the transformers differ for 1.0 and it only support 110v.  Also the speedball seems to have two boards instead of 1 like the newer one.


----------



## skhan007 (Apr 18, 2021)

Initial impressions of my first foray into rolling power tubes. Besides the stock one, I only have two: The Bendix 6080 and the Chatham 6AS7G. Well, after a week of A/B listening to a lot of music, I keep coming back to the Chatham as being slightly better to my ears. I do like the Bendix, as it has a crisp and polished presentation that is great of analytical listening. It's very strong in the details. However the Chatham has a very big, warm, and embracing nature to the sonic presentation. The Bendix does wonderfully with staging, but there's something about the Chatham that is quite noticeable to me, where it feels like the sonic equivalent of being wrapped in a newly woven fleece blanket and handed a piping hot mug of hot coco from my grandma. That's how this tube sounds to my ears!

A couple of you have stated you preferred the Chatham 6AS7G over other choices and I'm inclined to agree. Also, I don't have anything in the driver position to roll or compare, but this Chatham pairs beautifully with the clear top RCA. Open to driver suggestions as well, but so far, you brilliant lot have nailed it on your recommendations to me. Eternally thankful for the tips here!!! Oh, I also stained the base of my BHC Speedy to match my ZMF Auteur's. Came out very close.


----------



## PsilocybinCube

skhan007 said:


> Initial impressions of my first foray into rolling power tubes. Besides the stock one, I only have two: The Bendix 6080 and the Chatham 6AS7G. Well, after a week of A/B listening to a lot of music, I keep coming back to the Chatham as being slightly better to my ears. I do like the Bendix, as it has a crisp and polished presentation that is great of analytical listening. It's very strong in the details. However the Chatham has a very big, warm, and embracing nature to the sonic presentation. The Bendix does wonderfully with staging, but there's something about the Chatham that is quite noticeable to me, where it feels like the sonic equivalent of being wrapped in a newly woven fleece blanket and handed a piping hot mug of hot coco from my grandma. That's how this tube sounds to my ears!
> 
> A couple of you have stated you preferred the Chatham 6AS7G over other choices and I'm inclined to agree. Also, I don't have anything in the driver position to roll or compare, but this Chatham pairs beautifully with the clear top RCA. Open to driver suggestions as well, but so far, you brilliant lot have nailed it on your recommendations to me. Eternally thankful for the tips here!!! Oh, I also stained the base of my BHC Speedy to match my ZMF Auteur's. Came out very close.


For a long time, I wasn't s fan of the Chatham, but lately I've been using it my BHC driving my ZMF Verite and Eikon and I love it.

As for other driver tubes, the 6sn7 is nice, but dual 6j5 tubes is even more fun IMO.  @Deyan makes very high quality adapters.


----------



## skhan007

Oh man. How deep is the 6sn7 rabbit hole? Also, is the 6sn7 family notably superior to the 12au7 class?


----------



## jonathan c (Apr 18, 2021)

skhan007 said:


> Oh man. How deep is the 6sn7 rabbit hole? _About 7960 miles (diameter of earth)._





skhan007 said:


> Also, is the 6sn7 family notably superior to the 12au7 class? _I do not think that a tube family can be deemed categorically superior to another tube family without a specific application in mind. After that, one may need to consider the brand and oftentimes the year of manufacture within the brand._


----------



## skhan007

Thanks- let me revise my second question: I’m curious if folks have gone the 6sn7 route in the BHC and not looked back.


----------



## DenverW

skhan007 said:


> Oh man. How deep is the 6sn7 rabbit hole? Also, is the 6sn7 family notably superior to the 12au7 class?



Its all subjective as to what is "better."  I think they're a lot of great tubes in both categories.  My personal opinion is that average 6sn7 may have a sliiiight edge on average 12au7, but that the TOTL and best of the 12au7 are the best tubes overall for the crack.


----------



## skhan007

Have we listed TOTL 12au7 tubes for the BHC on this thread?


----------



## DenverW

skhan007 said:


> Have we listed TOTL 12au7 tubes for the BHC on this thread?



I haven’t tried all of the best, so my list would be incomplete.  For example, the Telefunken ecc802s tube is very highly regarded, but I haven’t found one in the realm of affordable pricing.  And honestly, I’ve been collecting these for a bit now, and I’ve seen the price on my favorites rising really high.

Favorite tubes: 
1. Earliest version amperex welded plate 45 degree slant getter
2. Marconi b329 or
3. Telefunken g73r
4. Telefunken smooth plate Champaign rods
5.  Earliest rca/victor 

A rule of thumb, welded plate tubes are often the oldest and most desireable you can get.  Not a hard rule, but something I often look for.


----------



## attmci

skhan007 said:


> Your opinion is very much appreciated.
> 
> What led me to these tubes- A lot of really strong reviews on this thread, the 6AS7G tube rolling thread, and reviews on a different forum. I've heard a couple people stating that the GEC 6080 was to them, superior to the Bendix 6080 (which I have) and even superior to the Chatham 6AS7G (which I have and absolutely love).
> 
> ...


Disagree. I recommend to go with the 5998 first. I believe a pair of 6BL7 or 6BX7 is also better than the GEC 6080. GEC 6AS7GT is another story. 

"GEC 6080 was to them, superior to the Bendix 6080 (which I have) and even superior to the Chatham 6AS7G (which I have and absolutely love)."


----------



## attmci

skhan007 said:


> Initial impressions of my first foray into rolling power tubes. Besides the stock one, I only have two: The Bendix 6080 and the Chatham 6AS7G. Well, after a week of A/B listening to a lot of music, I keep coming back to the Chatham as being slightly better to my ears. I do like the Bendix, as it has a crisp and polished presentation that is great of analytical listening. It's very strong in the details. However the Chatham has a very big, warm, and embracing nature to the sonic presentation. The Bendix does wonderfully with staging, but there's something about the Chatham that is quite noticeable to me, where it feels like the sonic equivalent of being wrapped in a newly woven fleece blanket and handed a piping hot mug of hot coco from my grandma. That's how this tube sounds to my ears!
> 
> A couple of you have stated you preferred the Chatham 6AS7G over other choices and I'm inclined to agree. Also, I don't have anything in the driver position to roll or compare, but this Chatham pairs beautifully with the clear top RCA. Open to driver suggestions as well, but so far, you brilliant lot have nailed it on your recommendations to me. Eternally thankful for the tips here!!! Oh, I also stained the base of my BHC Speedy to match my ZMF Auteur's. Came out very close.


Sounds like you need a Chatham 5998 immediately. LOL


----------



## attmci

DenverW said:


> I haven’t tried all of the best, so my list would be incomplete.  For example, the Telefunken ecc802s tube is very highly regarded, but I haven’t found one in the realm of affordable pricing.  And honestly, I’ve been collecting these for a bit now, and I’ve seen the price on my favorites rising really high.
> 
> Favorite tubes:
> 1. Earliest version amperex welded plate 45 degree slant getter
> ...


It will be nice if you can share some pictures of these rare tubes. Thx!


----------



## DenverW

attmci said:


> It will be nice if you can share some pictures of these rare tubes. Thx!



So if there is one talent I do NOT have, its taking good pictures.  I will do my best.  Here is the pre 1945 amperex welded plate slant D getter.  My favorite tube.





G73R tube from telefunken.  Rare tube made for avionics.




Marconi b329.  There are earlier and rarer versions of this tube, but non lottery winners are priced out.




Telefunken smooth plate.  These are not uncommon.  If you can find the older ones with champagne/copper rods get them.  Terrible picture, I'm sorry .  




1940's RCA/Victor tube.  Black plates, also a slant getter.  Great clarity, and not as bright as the later clear tops.




Honorable mention, the siemen's silver/chrome plate.  Double getter support.




Other tubes that I like that are not pictured...tung sol black glass (it's bright, so pair with a dark power tube), brimar long black plate square getter,  Mullard 10M gold pin (but super overpriced now), tungsram welded plate, multiple 5814 tubes...

Also, tubes marked red, white, or yellow were often specially selected for medical or other purposes, and often can be the best of their type.


----------



## Mightygrey

I've decided to start on a bit of a DIY mission to create a 'Multibit Crack' - installing a Schiit multibit DAC chip inside the chassis of my Crack + Speedball. Only problem is, I'm not sure how the ten-pin PCB header analogue-out from the Multibit DAC chip is configured. Any thoughts here on how it might work or how I might go about testing this so that I might be able to route it to the L/R/ground of the Crack?


----------



## tintinsnowydog

DenverW said:


> So if there is one talent I do NOT have, its taking good pictures.  I will do my best.  Here is the pre 1945 amperex welded plate slant D getter.  My favorite tube.
> 
> 
> 
> ...


Great collection of tubes! Have never seen the G73R before, super rare. Are there factory codes on the B329? I have always wondered with Marconi labelled tubes, as most have construction that look similar to Mullard k61


----------



## attmci

DenverW said:


> So if there is one talent I do NOT have, its taking good pictures.  I will do my best.  Here is the pre 1945 amperex welded plate slant D getter.  My favorite tube.
> 
> 
> 
> ...


Thanks a bunch for sharing, buddy. Too bad we can not see the inside of these precious tubes.


----------



## skhan007

Apologies if this has been asked already:

With an proper adapter, it it possible to run any of the following power tubes in the BHC:

KT66
EL34
6V6/6V6G

I ask because I have many of the above and was curious about putting them to use.


----------



## DenverW

attmci said:


> Thanks a bunch for sharing, buddy. Too bad we can not see the inside of these precious tubes.



Lol, dammit!  Ok, I’m using my phone.  Is there a tube you’d particularly like to see?  I can try to take a few better shots.


----------



## tintinsnowydog

skhan007 said:


> Apologies if this has been asked already:
> 
> With an proper adapter, it it possible to run any of the following power tubes in the BHC:
> 
> ...


These tubes won't be compatible with the BHC. The Bottlehead Moreplay preamp uses a pair of the 6V6 tubes though


----------



## Galapac

Well I took the plunge and just finished building my first amp. Very rewarding and I learned a lot so far.
I did most of the trouble shooting myself by going over all my solder work and it’s up and running.
Got a bit of static in the headphones so will check my phone jack solder work tomorrow.


----------



## DenverW

Galapac said:


> Well I took the plunge and just finished building my first amp. Very rewarding and I learned a lot so far.
> I did most of the trouble shooting myself by going over all my solder work and it’s up and running.
> Got a bit of static in the headphones so will check my phone jack solder work tomorrow.


Looks great!  Congrats on your build!


----------



## HTSkywalker

Paladin79 said:


> Thanks for your kind words.  Here is a Crack with one of the 6sn7's. I will be testing around 20 of them as part of a challenge I am involved with. I have help though.


That's no Finnegan ???? 😍😍😍


----------



## HTSkywalker

Galapac said:


> Well I took the plunge and just finished building my first amp. Very rewarding and I learned a lot so far.
> I did most of the trouble shooting myself by going over all my solder work and it’s up and running.
> Got a bit of static in the headphones so will check my phone jack solder work tomorrow.


Nice job there 👍


----------



## Paladin79

HTSkywalker said:


> That's no Finnegan ???? 😍😍😍


We have four cats and a dog. Finnegan is my buddy.


----------



## HTSkywalker

Paladin79 said:


> We have four cats and a dog. Finnegan is my buddy.


Probably the only cat who’s interested in tubes 😊


----------



## DeweyCH

Galapac said:


> Well I took the plunge and just finished building my first amp. Very rewarding and I learned a lot so far.
> I did most of the trouble shooting myself by going over all my solder work and it’s up and running.
> Got a bit of static in the headphones so will check my phone jack solder work tomorrow.


I both love and hate how you put the Bottlehead badge on top of the bell.


----------



## Galapac

DeweyCH said:


> I both love and hate how you put the Bottlehead badge on top of the bell.


My reasons for that are in case I wanted to refinish the wood the badge was out of the way and I wanted to be different. I took a cue from my 339i amp which had a badge on the bell as well. The finish was done with hammered paint. About 4-5 coats and then at least 2 weeks curing time so that takes the longest because you really cannot start the build until the paint fully cures.


----------



## HTSkywalker

Galapac said:


> My reasons for that are in case I wanted to refinish the wood the badge was out of the way and I wanted to be different. I took a cue from my 339i amp which had a badge on the bell as well. The finish was done with hammered paint. About 4-5 coats and then at least 2 weeks curing time so that takes the longest because you really cannot start the build until the paint fully cures.


Well it did pay, final product looks 👍


----------



## DeweyCH

I've got the slightest crackling in my right channel and I'm not really sure where to look. It comes and goes, it's only audible in quiet points of songs, but it's very annoying. It is audible when the pot is cranked to zero. Persistent between a RCA 12au7 and a Sylvania 6sn7 on an adapter.

Might it be the power tube? I'm almost afraid to try to see if my TS 5998 is right-channel fuzzy somehow.


----------



## Paladin79

DeweyCH said:


> I've got the slightest crackling in my right channel and I'm not really sure where to look. It comes and goes, it's only audible in quiet points of songs, but it's very annoying. It is audible when the pot is cranked to zero. Persistent between a RCA 12au7 and a Sylvania 6sn7 on an adapter.
> 
> Might it be the power tube? I'm almost afraid to try to see if my TS 5998 is right-channel fuzzy somehow.


I have been finding more and more TS 5998’s with pin issues. Try resoldering the pins, be sure all pins and sockets are clean as well.


----------



## DeweyCH

Paladin79 said:


> I have been finding more and more TS 5998’s with pin issues. Try resoldering the pins, be sure all pins and sockets are clean as well.


Gonna check with a different 6080-family tube back there first, but I'll take a peek at the pins when it's out.


----------



## DeweyCH (Apr 26, 2021)

Hmm... early indications seem to point at the TS. RCA 6AS7 is in there now and there's no static. I'll try some DeOxit on the TS pins before anything else.

EDIT: Nevermind, right-channel static came back as the tubes warmed up. I suspect it might be something with the 12-pin socket, like I pushed something too close to something else while rolling.


----------



## Paladin79

DeweyCH said:


> Hmm... early indications seem to point at the TS. RCA 6AS7 is in there now and there's no static. I'll try some DeOxit on the TS pins before anything else.


That makes sense, my response was a bit out of order but always try the easy things first. I have at least a half dozen of the TS 5998's and finally just replaced the solder in all pins after they started acting up. In once case I was getting a low hum with certain driver tubes, two more began to crackle a bit.  I also just fixed two GE 5998A's from the late 70's, the solder looked great but maybe their technique was the issue lol. Anyway they were an easy fix.


----------



## HTSkywalker

DeweyCH said:


> I've got the slightest crackling in my right channel and I'm not really sure where to look. It comes and goes, it's only audible in quiet points of songs, but it's very annoying. It is audible when the pot is cranked to zero. Persistent between a RCA 12au7 and a Sylvania 6sn7 on an adapter.
> 
> Might it be the power tube? I'm almost afraid to try to see if my TS 5998 is right-channel fuzzy somehow.


The easiest fix is to re-solder as a starter.


----------



## PsilocybinCube (Apr 26, 2021)

Dumb resoldering question...are you starting by replacing the solder entirely?  Or are you heating up the pin such that the solder flows a bit but NOT replacing the solder?

I know that @Paladin79 has shared the process to suck out the old solder and start anew, but I didn't know if you would first start with my lazy method...I did bring a TS back to life with the lazy method recently...


----------



## Paladin79 (Apr 26, 2021)

PsilocybinCube said:


> Dumb resoldering question...are you starting by replacing the solder entirely?  Or are you heating the up pin such that the solder flows a bit but NOT replacing the solder?
> 
> I know that @Paladin79 has shared the process to suck out the old solder and start anew, but I didn't know if you would first start with my lazy method...I did bring a TS back to life with the lazy method recently...


I really do not trust the Russian solder on Melz or Fotons so I replace that. Two GE 5998A's that failed had wonderful looking solder so I added a bit more with silver content just to insure good flow inside the tube, and to take advantage of some fresh rosin at the center of said solder. To me that is more like a reflow and it was all that was required. Some of the folks with TS 5998's seem to have to reflow the solder a few times before a positive improvement so I am more apt to replace the solder on those.


----------



## HTSkywalker

Paladin79 said:


> I really do not trust the Russian solder on Melz or Fotons so I replace that. Two GE 5998A's that failed had wonderful looking solder so I added a bit more with silver content just to insure good flow inside the tube, and to take advantage of some fresh rosin at the center of said solder. To me that is more like a reflow and it was all that was required. Some of the folks with TS 5998's seem to have to reflow the solder a few times before a positive improvement so I am more apt to replace the solder on those.


I second @Paladin79, emptying and refilling new solder is the best way but you can start the lazy way first, may solve it for you


----------



## Tom-s

I started cooking today! Now it's a matter of patience.


----------



## HTSkywalker

Tom-s said:


> I started cooking today! Now it's a matter of patience.


Good paint job 👍


----------



## Galapac

Tom-s said:


> I started cooking today! Now it's a matter of patience.


Nice color! Making two?


----------



## skhan007

Galapac said:


> Well I took the plunge and just finished building my first amp. Very rewarding and I learned a lot so far.
> I did most of the trouble shooting myself by going over all my solder work and it’s up and running.
> Got a bit of static in the headphones so will check my phone jack solder work tomorrow.


Slotted Bendix 6080?


----------



## Wes S

skhan007 said:


> Slotted Bendix 6080?


There is no other tube that looks like that, so without a doubt that is a Bendix.  That is the best power tube I have heard hands down.


----------



## HTSkywalker

Wes S said:


> There is no other tube that looks like that, so without a doubt that is a Bendix.  That is the best power tube I have heard hands down.


Better than the TS 5998 ???🙄🙄


----------



## Wes S (Apr 28, 2021)

HTSkywalker said:


> Better than the TS 5998 ???🙄🙄


Heck yes.  If you like bass impact, and amazing seperation and air in the mids and treble, the Bendix is your tube.  The TS 5998 was the first power tube I rolled, and it was great until I heard what a Bendix can do.


----------



## skhan007 (Apr 28, 2021)

Wes S said:


> There is no other tube that looks like that, so without a doubt that is a Bendix.  That is the best power tube I have heard hands down.


Yes, I have one as well and it's great- Although it's been displaced now that I've got the GEC 6080, which I think I like better, by a bit.


----------



## jonathan c

Wes S said:


> There is no other tube that looks like that, so without a doubt that is a Bendix.  That is the best power tube I have heard hands down.


The best power tube “in and of itself” or when paired with [ choose ] driver tube(s) ?


----------



## Galapac

On the Crack I pair the Bendix with a Mullard 12AU7 and it’s out of this world with lots of headspace. This is pre speedball so I am excited to see what that has to offer after I install it. It will be awhile as I want to get used to the Crack and give it plenty of burn in time before I change anything.


----------



## HTSkywalker

Galapac said:


> On the Crack I pair the Bendix with a Mullard 12AU7 and it’s out of this world with lots of headspace. This is pre speedball so I am excited to see what that has to offer after I install it. It will be awhile as I want to get used to the Crack and give it plenty of burn in time before I change anything.


Any positive experience with lower than 150 Ohms cans with the BHC ?


----------



## HTSkywalker

Wes S said:


> Heck yes.  If you like bass impact, and amazing seperation and air in the mids and treble, the Bendix is your tube.  The TS 5998 was the first power tube I rolled, and it was great until I heard what a Bendix can do.


Where did you buy it from ?


----------



## Wes S

jonathan c said:


> The best power tube “in and of itself” or when paired with [ choose ] driver tube(s) ?


The best.  It pairs incredible with every driver out there.


----------



## Galapac

HTSkywalker said:


> Any positive experience with lower than 150 Ohms cans with the BHC ?


I tried the Focal Utopias with them which are 80 ohm with no issues. I didn't use them long enough to make an opinion as I mainly use ZMF cans for my listening.



HTSkywalker said:


> Where did you buy it from ?


If you are asking about the tubes I do not remember. I have had the Bendix for a long time and who knows on the 12AU7, lol.


----------



## Wes S

HTSkywalker said:


> Where did you buy it from ?


A forum member.


----------



## Mightygrey

HTSkywalker said:


> Any positive experience with lower than 150 Ohms cans with the BHC ?


The 5998 power tube lower the output Z of the Crack somewhat, it can warm-up certain lower Z cans such as the Focal range pretty enjoyably.


----------



## HTSkywalker

Mightygrey said:


> The 5998 power tube lower the output Z of the Crack somewhat, it can warm-up certain lower Z cans such as the Focal range pretty enjoyably.


I have the Elear so that’s good news 👍
Thanks


----------



## Tom-s (May 2, 2021)

Today I build a Crack. It's the one from last weeks pictures. I cheated the Hammerite dry times of 2-4 weeks by using the oven.

So this morning I started the journey and am now enjoying the new build Crack!
Leds lit. All checked out first time. And it's sounding great!

Here it sits next to my other Crack. This one looks better! 




What's done!
In no particular order.
Input wiring and all signal wires are silver plated solid core copper.
FAQ #3 was implemented for optimizing usable volume range.
The volume pot is a stepped ladder time with SMD resistors. For better balance and sound quality.

The 6SN7 is used as input tube.
The Speedball small board was replaced by a switch board. This allows to switch between 3.6mA; 7,2mA and 8,2mA.
The first option is for 6SN7's. The other 2 options are for; par example; 12BH7's; E88CC's. Depending on the condition of the tube (and sound preference).

The power supply uses Shottky SIC diodes as bridge rectifier. And a Hammond 158M choke as second resistor in the power supply.
A film cap still needs to be installed; space is there. This is for another time. I preferred to do the base build without for troubleshooting reasons.
Same goes for the diode ground mod by PB. During this fase; i prefer a solid wire connection to ground.

For output caps Mundorf film types were installed.

It's

Edit: Don't know why i stopped at It's. Anyhow; i'll enjoy this on the coming evenings; as is. Next weekend. Building a base and the rest of the upgrades.


----------



## Mightygrey

Tom-s said:


> Today I build a Crack. It's the one from last weeks pictures. I cheated the Hammerite dry times of 2-4 weeks by using the oven.
> 
> So this morning I started the journey and am now enjoying the new build Crack!
> Leds lit. All checked out first time. And it's sounding great!
> ...


Very neat job. Nice work! Making me want to upgrade my caps...


----------



## HTSkywalker

Tom-s said:


> Today I build a Crack. It's the one from last weeks pictures. I cheated the Hammerite dry times of 2-4 weeks by using the oven.
> 
> So this morning I started the journey and am now enjoying the new build Crack!
> Leds lit. All checked out first time. And it's sounding great!
> ...


Indeed very neat and innovative job 👍


----------



## HTSkywalker

Tom-s said:


> Today I build a Crack. It's the one from last weeks pictures. I cheated the Hammerite dry times of 2-4 weeks by using the oven.
> 
> So this morning I started the journey and am now enjoying the new build Crack!
> Leds lit. All checked out first time. And it's sounding great!
> ...


What cans are you using with the BHC


----------



## skhan007 (May 5, 2021)

Question about line level between the DAC and BHC:

I'm running my DAC (RME ADI-2) at -5dBu into the BHC. At this level, I find the BHC volume at about 9 or 10 O'Clock, which I think is pretty low on the dial, but sufficient and comfortable volume for me and my ZMF cans (about 70 dB listening level).

Curious if the BHC needs to be up at Noon or higher to get the proper tube benefits (i.e. the qualities we tend to love about tubes being driven at sufficient levels). I can certainly use my ears and dial down the output of the DAC a bit and turn up the volume on the BHC, but mostly curious how other people run their signal into the BHC?


----------



## HTSkywalker

skhan007 said:


> Question about line level between the DAC and BHC:
> 
> I'm running my DAC (RME ADI-2) at -5dBu into the BHC. At this level, I find the BHC volume at about 9 or 10 O'Clock, which I think is pretty low on the dial, but sufficient and comfortable volume for me and my ZMF cans (about 70 dB listening level).
> 
> Curious if the BHC needs to be up at Noon or higher to get the proper tube benefits (i.e. the qualities we tend to love about tubes being driven at sufficient levels). I can certainly use my ears and dial down the output of the DAC a bit and turn up the volume on the BHC, but mostly curious how other people run their signal into the BHC?


Normally you crank the DAC volume all the way up into the BHC, the less volume used on a tube amp the less audible humming and hissing.


----------



## Galapac

skhan007 said:


> Question about line level between the DAC and BHC:
> 
> I'm running my DAC (RME ADI-2) at -5dBu into the BHC. At this level, I find the BHC volume at about 9 or 10 O'Clock, which I think is pretty low on the dial, but sufficient and comfortable volume for me and my ZMF cans (about 70 dB listening level).
> 
> Curious if the BHC needs to be up at Noon or higher to get the proper tube benefits (i.e. the qualities we tend to love about tubes being driven at sufficient levels). I can certainly use my ears and dial down the output of the DAC a bit and turn up the volume on the BHC, but mostly curious how other people run their signal into the BHC?


I guess it depends on your use. For me I use a FiiO DAP so I run an RCA to USB-C line that reaches my chair. I set the tube amp anywhere from 10 to noon on the dial and then control the volume from my DAP to increase/decrease the volume from my chair. I get very minimal hum depending on the tubes, if it is a 6080 very minimal, a 5998 has a bit more due to the gain.


----------



## eimis

Bottlehead interview


----------



## HTSkywalker

In fact am checking on the Bottlehead Moreplay as a preamp to my high end system. sounds interesting but not much previews.


----------



## xkonfuzed

I have found that lower the input voltage into the Crack, the more I can avoid the initial channel imbalance from the potentiometer. Also it seems that with a 3V input form my Mojo I am rarely ever going past 11-12 on the knob on any of my headphones. When I run it at 2V I can get a lot more out of the amp.


----------



## headphone hedonist

Question about a recent post, 


Tom-s said:


> The Speedball small board was replaced by a switch board. This allows to switch between 3.6mA; 7,2mA and 8,2mA.


Is this pcb available for sale? 
As a kit or just the board, doesn't matter.
If so, any information on where to purchase, or have one made would be greatly appreciated.

Thanks.


----------



## Tom-s (May 9, 2021)

These switch boards were made for my own personal use. I have a few spares available, as these PCB makes have a minimal order number.
Let's continue via PM.

Edit: build some BH bases today. 2x Crack. 1x Eros.


----------



## DeweyCH

Upgraded my Crack - after having it built for a couple of months, I finally added the Speedball package and replaced the stock pot with a 20k DACT-style stepped attenuator.

Other than being an idiot and miswiring the attenuator the first time, it sounds really great! I re-did the braided wire from the inputs to the pot, too. All in all, a DEAD SILENT noise floor, whereas the old pot/lack of Speedball had some static popping up enough to be annoying in the right channel.

Now I just need a better knob, because this one I got from eBay is just absurd looking.





Philips ECC82/12AU7 in the front with a RCA 6AS7 in the back. Not my everyday tubes, but a couple that are nice but I won't be too sad if I f'ed up something in the wiring and they melted. But they didn't. So huzzah.


----------



## xkonfuzed

Looks nice! Do you like the sound with Speedball more, or without?

I'm running JAN 6AS7G as well. Really smooth tube. I'm looking at input tubes to replace my RCA cleartop, to me its a bit too forward and can end up sounding too shouty in mid-forward headphones. Do you like the Phillips ECC82?


----------



## DeweyCH

xkonfuzed said:


> Looks nice! Do you like the sound with Speedball more, or without?
> 
> I'm running JAN 6AS7G as well. Really smooth tube. I'm looking at input tubes to replace my RCA cleartop, to me its a bit too forward and can end up sounding too shouty in mid-forward headphones. Do you like the Phillips ECC82?


To be honest, I think it's too early to tell which sound I like. Haven't even rolled in my better tubes yet. But I will say the noise floor is dramatically different. I also figure that some of the difference I'm hearing right now in terms of less background stuff is from the pot change. Getting overzealous and doing both Speedball and pot swap at the same time might have hampered my ability to test the outcomes.

The Philips is fine, but I prefer my RCA cleartop. I got a pair of the Philips to try and plop into a Liquid Platinum, and they ended up being replaced rather quickly by RCA cleartops. Generally I like using 6SN7 variants with a Garage1217 adapter - either my Sylvania metal-base or my brown-base CBS/Hytron. Then again, I built the Crack after a whole lot of tube-rolling on a Darkvoice, so maybe it's just what I have on hand...

(Also a HUGE fan of putting a dual-6J5 adapter into a 6SN7 socket... haven't tried yet on the Crack running 12AU7-6SN7 adapter then 6SN7-dual 6J5 adapter. But I will.)


----------



## DeweyCH (May 10, 2021)

Speaking of double-adaptering... this sounds amazing:






Still the RCA 6AS7 in the back, 12AU7 socket is being converted to a 6SN7 which is in turn being converted into two 6J5s. I have two Super Silvertone 6L5 tubes in there. This is possibly my favorite driver tube setup from my Darkvoice, and it sounds fabulous here, too. Hoping @Deyan can make me a 12AU7 --> dual 6J5 adapter to skip the adapters-on-adapters thingy.


----------



## DeweyCH

Sorry for blathering so much, but wow... "Hey Jude" has this left-channel acoustic guitar part that is just buried in the background, but with my Crack set up like you see above and my Auteurs, it's so clear and just... hearable. I love hearing parts of songs I've listened to forever but never noticed.


----------



## Galapac (May 10, 2021)

DeweyCH said:


> Upgraded my Crack - after having it built for a couple of months, I finally added the Speedball package and replaced the stock pot with a 20k DACT-style stepped attenuator.
> 
> Other than being an idiot and miswiring the attenuator the first time, it sounds really great! I re-did the braided wire from the inputs to the pot, too. All in all, a DEAD SILENT noise floor, whereas the old pot/lack of Speedball had some static popping up enough to be annoying in the right channel.
> 
> ...


Great job Dewey! I agree the knob is a bit out of place ,lol. I need to do my speed ball but I'm in no rush. I want to burn this in for a month or so then go ahead and install.
It's funny that you need to rip out parts that you installed like the large resistors but all in the name of progress I guess..
Can you PM me where you got the attentuator?


----------



## HTSkywalker

xkonfuzed said:


> Looks nice! Do you like the sound with Speedball more, or without?
> 
> I'm running JAN 6AS7G as well. Really smooth tube. I'm looking at input tubes to replace my RCA cleartop, to me its a bit too forward and can end up sounding too shouty in mid-forward headphones. Do you like the Phillips ECC82?


Try a Tung Sol 5998 or a GE 5998A


----------



## Galapac

DeweyCH said:


> Sorry for blathering so much, but wow... "Hey Jude" has this left-channel acoustic guitar part that is just buried in the background, but with my Crack set up like you see above and my Auteurs, it's so clear and just... hearable. I love hearing parts of songs I've listened to forever but never noticed.


I had the same epiphany when listening to the Beatles' song Come Together. You can actually hear John Lennon whisper "shoot me" in the beginning of the song....gives you goose bumps. I never noticed that until I had a good set of headphones/amp.


----------



## DeweyCH

Galapac said:


> I had the same epiphany when listening to the Beatles' song Come Together. You can actually hear John Lennon whisper "shoot me" in the beginning of the song....gives you goose bumps. I never noticed that until I had a good set of headphones/amp.


Beatles are good for that. First time I listened to my Auteurs it was the "ooh la la la"s in You Won't See Me.


----------



## DenverW

If anyone wants to try a different Bottlehead amp I’ve posted my upgraded mainline in the classifieds.  Will I regret it?  Yea probably .

Interested in trading for a Bottlehead sex or their new estat amp.  Love me some Bottlehead!


----------



## HTSkywalker

DeweyCH said:


> To be honest, I think it's too early to tell which sound I like. Haven't even rolled in my better tubes yet. But I will say the noise floor is dramatically different. I also figure that some of the difference I'm hearing right now in terms of less background stuff is from the pot change. Getting overzealous and doing both Speedball and pot swap at the same time might have hampered my ability to test the outcomes.
> 
> The Philips is fine, but I prefer my RCA cleartop. I got a pair of the Philips to try and plop into a Liquid Platinum, and they ended up being replaced rather quickly by RCA cleartops. Generally I like using 6SN7 variants with a Garage1217 adapter - either my Sylvania metal-base or my brown-base CBS/Hytron. Then again, I built the Crack after a whole lot of tube-rolling on a Darkvoice, so maybe it's just what I have on hand...
> 
> (Also a HUGE fan of putting a dual-6J5 adapter into a 6SN7 socket... haven't tried yet on the Crack running 12AU7-6SN7 adapter then 6SN7-dual 6J5 adapter. But I will.)


How does the DV compares to the Crack with and without Speedball ?


----------



## DeweyCH

HTSkywalker said:


> How does the DV compares to the Crack with and without Speedball ?


It holds its own nicely. Now, to be fair I've done a LOT of upgrading to the DV... all the 6SN7 socket resistors were replaced, both tube sockets were replaced, the pot was upgraded first to an Alps 50k with a shunt mod, then to a stepped attenuator, I installed, removed and reinstalled a Fitz mod, the heater cables were replaced with a twisted pair, the power switch was replaced, and a virtual center tap was created. Here's the guts of the DV more or less right now (still has the Alps in it, but you get the idea):





So it's not so much a direct DV-vs-Crack comparison. That said, I'd probably say that the modded DV is pretty much on par with a baseline Crack, whereas the Speedball (so far) sounds much better than either/both.

Now that the Speedball is in and the DV has been relegated to "other OTL amp" status, I'm planning on experimenting further yet. I've got some Nichicon caps to replace those six red ones. I'll never be as aggressively talented at this as the folks I learned from in the DV tuberolling thread, but hey, it's fun!

TLR response to your actual question:

Crack + Speedball >>> Crack == Modded DV >>>>>>>> stock DV.


----------



## HTSkywalker

DeweyCH said:


> It holds its own nicely. Now, to be fair I've done a LOT of upgrading to the DV... all the 6SN7 socket resistors were replaced, both tube sockets were replaced, the pot was upgraded first to an Alps 50k with a shunt mod, then to a stepped attenuator, I installed, removed and reinstalled a Fitz mod, the heater cables were replaced with a twisted pair, the power switch was replaced, and a virtual center tap was created. Here's the guts of the DV more or less right now (still has the Alps in it, but you get the idea):
> 
> 
> 
> ...


Well clear enough 🙂
What cans were you using ?


----------



## DeweyCH

HTSkywalker said:


> Well clear enough 🙂
> What cans were you using ?


ZMF Auteurs mostly. Some ZMF Verite Closeds, but those typically live in my bedroom with my Liquid Platinum (also recently up off the upgrade bench).


----------



## HTSkywalker

DeweyCH said:


> ZMF Auteurs mostly. Some ZMF Verite Closeds, but those typically live in my bedroom with my Liquid Platinum (also recently up off the upgrade bench).


a 300 Ohms cans would definitely weigh in especially with the Crack, I have a Focal rated at 80 Ohms, not that great mating with the BHC


----------



## DeweyCH

HTSkywalker said:


> a 300 Ohms cans would definitely weigh in especially with the Crack, I have a Focal rated at 80 Ohms, not that great mating with the BHC


Yeah, the ZMFs love OTL amps. So do my old AKG K240s (600 ohms). How do the Focals sound w/the BHC?


----------



## wabibito

Last week i started helping my friend building the crack for the first time.  We got an older unbuilt kit off ebay recently.  It was quite an experience.  So far it sounds good.  Next will be wiring in the mods and speedball.  I made a small case for the Cree Diodes and test mount the Choke.  Everything seems to fit perfectly.


----------



## HTSkywalker

DeweyCH said:


> Yeah, the ZMFs love OTL amps. So do my old AKG K240s (600 ohms). How do the Focals sound w/the BHC?


In fact I don't own a BHC, although am planning for a Bottlehead Moreplay preamp but I have a Violectric V90, a Cavalli CTH and the DV along with the Focal Elear and Hifiman Ananda and an AKG 550.
The Violectric is an all rounder, the Cavalli is so clean with a beautiful tubey sound. The DV is the most tubey and I don't regret it even though with the slight hum.


----------



## DeweyCH

HTSkywalker said:


> In fact I don't own a BHC, although am planning for a Bottlehead Moreplay preamp but I have a Violectric V90, a Cavalli CTH and the DV along with the Focal Elear and Hifiman Ananda and an AKG 550.
> The Violectric is an all rounder, the Cavalli is so clean with a beautiful tubey sound. The DV is the most tubey and I don't regret it even though with the slight hum.


I'd be curious to hear the CTH against Cavalli/Monoprice's Liquid Platinum.

DV is a solid amp once you fix all the things that are wrong with it.


----------



## cddc

wabibito said:


> Last week i started helping my friend building the crack for the first time.  We got an older unbuilt kit off ebay recently.  It was quite an experience.  So far it sounds good.  Next will be wiring in the mods and speedball.  I made a small case for the Cree Diodes and test mount the Choke.  Everything seems to fit perfectly.




You must have spent lots of time reading and studying on Crack before building, hard to imagine a noob with no prior experience can figure out the excellent implementation of the upgrades.

Great work!


----------



## cddc

DenverW said:


> If anyone wants to try a different Bottlehead amp I’ve posted my upgraded mainline in the classifieds.  Will I regret it?  Yea probably .
> 
> Interested in trading for a Bottlehead sex or their new estat amp.  Love me some Bottlehead!




I don't have low impedance cans, otherwise would have considered your upgraded Mainline.


----------



## DenverW

cddc said:


> I don't have low impedance cans, otherwise would have considered your upgraded Mainline.



It honestly works great with pretty much anything.  I wouldn't be giving it up but I want to try estats so I need to sell one of my larger pieces of gear to give it a fair shake.  I mostly have high impedance stuff for my bottlehead gear, so I was using the mainline with my Auteurs and HD800.  The difference is this worked with my emu-teak as well.


----------



## DeweyCH

wabibito said:


> Last week i started helping my friend building the crack for the first time.  We got an older unbuilt kit off ebay recently.  It was quite an experience.  So far it sounds good.  Next will be wiring in the mods and speedball.  I made a small case for the Cree Diodes and test mount the Choke.  Everything seems to fit perfectly.


Listen, can y'all start a thread for absolute professionals? You're making scrubs like me feel bad.

Amazing work, seriously. Where's a picture of the completed product driving some cans?


----------



## wabibito

cddc said:


> You must have spent lots of time reading and studying on Crack before building, hard to imagine a noob with no prior experience can figure out the excellent implementation of the upgrades.
> 
> Great work!


yes,  Since i am building it for a friend, and it is an older crack version 1.0.  I spent a lot of time understand the mod.  So there is three mod i think that is cheap, Cree, Choke and the UF4007 in the grounding.  The reason why i made the case is from what i read, the Cree diodes get very hot.  So this way he won't accidentally touch it and the casing is open enough to have no heat issue.  I also added a new power switch that fit existing slot.  This has different wiring so it will glow green when it turns on.  It is a worth it 3 dollars mod hehe.


----------



## wabibito

DeweyCH said:


> Listen, can y'all start a thread for absolute professionals? You're making scrubs like me feel bad.
> 
> Amazing work, seriously. Where's a picture of the completed product driving some cans?


Thank you for the complement, I was quite surprised it fit as well as it should, my friend is testing out the base crack now before adding the speed ball then wiring in the mod.  Though since everything so tight, have to plan fit everything upfront.


----------



## cddc

wabibito said:


> yes,  Since i am building it for a friend, and it is an older crack version 1.0.  I spent a lot of time understand the mod.  So there is three mod i think that is cheap, Cree, Choke and the UF4007 in the grounding.  The reason why i made the case is from what i read, the Cree diodes get very hot.  So this way he won't accidentally touch it and the casing is open enough to have no heat issue.  I also added a new power switch that fit existing slot.  This has different wiring so it will glow green when it turns on.  It is a worth it 3 dollars mod hehe.




The stock power switch is prone to melting, Bottlehead has made a Youtube video to warn builders not to touch the pins of the switch with soldering iron for too long.

The $3 power switch mod is well worth it


----------



## wabibito

cddc said:


> The stock power switch is prone to melting, Bottlehead has made a Youtube video to warn builders not to touch the pins of the switch with soldering iron for too long.
> 
> The $3 power switch mod is well worth it


Yes, since it is from amazon and doesn't come with any instruction, it took a while to figure out with the multimeter.  it actually have 4 pins.  I ended up have to run both L and N from power to the switch then run through the transformer.  This then make the switch light up when turns on and turns off when it is off.  It works much better than the 3 pin led switch where you need external led power.


----------



## cddc

DenverW said:


> It honestly works great with pretty much anything.  I wouldn't be giving it up but I want to try estats so I need to sell one of my larger pieces of gear to give it a fair shake.  I mostly have high impedance stuff for my bottlehead gear, so I was using the mainline with my Auteurs and HD800.  The difference is this worked with my emu-teak as well.



Agree, if I had both low impedance and high impedance headphones, I would have considered something like the Mainline, which works great for both of them with an impedance switch. I'm a big fan of Sennheiser and all my cans are high impedance cans. I am so saddened by the sale of Sennheiser recently. An era has come to an end. 

Good luck with your journey to the electrostatic land, hope you find something excellent there.


----------



## cddc

wabibito said:


> Yes, since it is from amazon and doesn't come with any instruction, it took a while to figure out with the multimeter.  it actually have 4 pins.  I ended up have to run both L and N from power to the switch then run through the transformer.  This then make the switch light up when turns on and turns off when it is off.  It works much better than the 3 pin led switch where you need external led power.




I check the glow of tubes on my BHC to see if the amp is ON or OFF, but obviously having an indicating LED is better


----------



## wabibito

cddc said:


> I check the glow of tubes on my BHC to see if the amp is ON or OFF, but obviously having an indicating LED is better


just check, it even cheaper if you buy 6. $1 each.
https://www.amazon.com/Twidec-Illum...oat+switch+rocker+illuminated,aps,240&sr=8-21

My reason i like the dedicated light is that case where somehow the amp failed and tube doesn't glow.


----------



## DenverW

cddc said:


> Agree, if I had both low impedance and high impedance headphones, I would have considered something like the Mainline, which works great for both of them with an impedance switch. I'm a big fan of Sennheiser and all my cans are high impedance cans. I am so saddened by the sale of Sennheiser recently. An era has come to an end.
> 
> Good luck with your journey to the electrostatic land, hope you find something excellent there.



Whoa!  Let’s not get them impression I’m leaving tube land!  I still have my crackatwoa at home and a s.e.x. At work .


----------



## Galapac

Will a 20k pot work in a BHC without any retrofitting?
Is it a direct replacement?


----------



## wabibito

Galapac said:


> Will a 20k pot work in a BHC without any retrofitting?
> Is it a direct replacement?


It should works though the default stock one is 100k.


----------



## DeweyCH

Galapac said:


> Will a 20k pot work in a BHC without any retrofitting?
> Is it a direct replacement?


Yeah. That's what I've got in mine now - a 20k stepped attenuator. No problem whatsoever.


----------



## elsanto

Has anyone compared this kit to the pass labs ACP+ ?  I've been enjoying the acp+ for a while but looking for something differenct.. thanks!
https://diyaudiostore.com/products/acp-amp-camp-pre-amp


----------



## Galapac (May 11, 2021)

elsanto said:


> Has anyone compared this kit to the pass labs ACP+ ?  I've been enjoying the acp+ for a while but looking for something differenct.. thanks!
> https://diyaudiostore.com/products/acp-amp-camp-pre-amp


The ACP is a solid state amp correct? I have not had experience with the ACP but it looks cool. Is the sound neutral, meaning no color like a tube amp?
I would be interested in comparing the starving student model to BHC.
https://diyaudiostore.com/collections/headphone-amplifiers/products/starving-student-ii


----------



## JamieMcC

elsanto said:


> Has anyone compared this kit to the pass labs ACP+ ?  I've been enjoying the acp+ for a while but looking for something differenct.. thanks!
> https://diyaudiostore.com/products/acp-amp-camp-pre-amp



Firstly I'm not able to compare the ACP+ directly to the Crack but have owned the Bottlehead  Crack, Sex and Mainline and the original ACA which I used to drive my Hifiman HE6 paired with a Bottlehead Quickie (pre amp) with excellent results. 

I have always thought the ACA more comparable sonically to the Bottlehead Sex amp than the Crack.  The Sex being a little bit sweeter in the mid range and the ACA being faster and more controlled in the bass.

Sonically especially in stock 
non speedball form I would expect the Crack to offer quiet a different presentation to the ACA+ may perhaps be a step backwards technically but am only basing that view on my experience with the ACA not the ACA+

The Crack is a rewarding project hot rodding and tube rolling add further dimensions as does connecting with the Bottlehead community here and on the BHF.


----------



## skhan007 (May 12, 2021)

An absolutely self-indulgent and purposeless "upgrade" to my BHC. Why, you ask? Because I'm a fan of Hard Rock! Yes, I'll be using this pun quite often moving forward...

Also, please recommend some feet that would go nice with this!


----------



## cddc

LOL...I recommend some roller feet so that you can have Rock N' Roll


----------



## raindownthunda

skhan007 said:


> An absolutely self-indulgent and purposeless "upgrade" to my BHC. Why, you ask? Because I'm a fan of Hard Rock! Yes, I'll be using this pun quite often moving forward...
> 
> Also, please recommend some feet that would go nice with this!



Dude - way to be different!! I would probably get some decorative  feet to make a true statement piece. This Etsy seller has some wild “jewelry box legs”:  https://etsy.me/2NjvjYh

Some of my favorites:


----------



## cddc (May 12, 2021)

Joke aside, there are too many choices for feet.

The decorative metal feet above seem pretty nice.

You can also consider feet that are more geared towards vibration/shock isolation, like these:


----------



## DenverW

skhan007 said:


> An absolutely self-indulgent and purposeless "upgrade" to my BHC. Why, you ask? Because I'm a fan of Hard Rock! Yes, I'll be using this pun quite often moving forward...
> 
> Also, please recommend some feet that would go nice with this!



I absolutely love that!  Play some ‘heavy’ metal with all the rock!  maybe some stones?


----------



## Galapac

skhan007 said:


> An absolutely self-indulgent and purposeless "upgrade" to my BHC. Why, you ask? Because I'm a fan of Hard Rock! Yes, I'll be using this pun quite often moving forward...
> 
> Also, please recommend some feet that would go nice with this!


What type of stone is that? Soapstone? Marble? Granite? Must have some heft to it.


----------



## lalawilson168

elsanto said:


> Has anyone compared this kit to the pass labs ACP+ ?  I've been enjoying the acp+ for a while but looking for something differenct.. thanks!
> https://diyaudiostore.com/products/acp-amp-camp-pre-amp



I have both on my desk currently, and tbh we are not really comparing apples to apples. since one is OTL tube amp and the other SS amp with a small SMPS. Having said that, ACP+ does have that euphoric almost tube like sound signature and its much cheaper and easier to build (the resistor matching part is a bit of a pain... but thats another story). I'd say if you have high impedance HPs like the Sens HD stuff, go with the BHC, and if you have a range of HPs with different  impedances, I would highly recommend the other amp on diyaudiostore, namely Whammy.


----------



## cddc (May 13, 2021)

DenverW said:


> I absolutely love that!  Play some ‘heavy’ metal with all the rock!  maybe some stones?



Some stones...


----------



## wabibito (May 13, 2021)

Finally finish the speed ball and the mod. Boy this sound great.  Learned a trick while studying the build reversed the 100uF so it folded nicely under the speedball.


----------



## HTSkywalker

skhan007 said:


> An absolutely self-indulgent and purposeless "upgrade" to my BHC. Why, you ask? Because I'm a fan of Hard Rock! Yes, I'll be using this pun quite often moving forward...
> 
> Also, please recommend some feet that would go nice with this!


Is that granite ? looks awesome 👍
Definitely needs some stand offs for ventilation


----------



## HTSkywalker

cddc said:


> LOL...I recommend some roller feet so that you can have Rock N' Roll


Or some rockers even for that same purpose lol


----------



## HTSkywalker

cddc said:


> Joke aside, there are too many choices for feet.
> 
> The decorative metal feet above seem pretty nice.
> 
> You can also consider feet that are more geared towards vibration/shock isolation, like these:


The golden ones would go nicely, same as the golden knob on the BHC


----------



## HTSkywalker

Galapac said:


> What type of stone is that? Soapstone? Marble? Granite? Must have some heft to it.


Looks like granite to me, pretty innovative 👌


----------



## wabibito

skhan007 said:


> An absolutely self-indulgent and purposeless "upgrade" to my BHC. Why, you ask? Because I'm a fan of Hard Rock! Yes, I'll be using this pun quite often moving forward...
> 
> Also, please recommend some feet that would go nice with this!


Man that thing is a beauty.


----------



## HTSkywalker

wabibito said:


> Finally finish the speed ball and the mod. Boy this sound great.  Learned a trick while studying the build reversed the 100uF so it folded nicely under the speedball.


Good job there, Is that a 6080 Power tube in the back ?


----------



## wabibito

HTSkywalker said:


> Good job there, Is that a 6080 Power tube in the back ?


Yup. The default tube


----------



## HTSkywalker

wabibito said:


> Yup. The default tube


So a 6AS7G would also also work ?
How about the pre-amp tube, would 6SN7 fit with or without adapter ?


----------



## skhan007

Galapac said:


> What type of stone is that? Soapstone? Marble? Granite? Must have some heft to it.





HTSkywalker said:


> Is that granite ? looks awesome 👍
> Definitely needs some stand offs for ventilation


Yes, granite! Very hefty.


----------



## wabibito

HTSkywalker said:


> So a 6AS7G would also also work ?
> How about the pre-amp tube, would 6SN7 fit with or without adapter ?


I assumed the 6AS7G should also work.  The front tube is a 9 pin.  I do have a garage1217 adapter to 6SN7 that i use for my project ember II.  Though from what i read the voltage or something need to change for it to work with 6SN7.  When i get my own crack, I will try it out.


----------



## wabibito

Next stop is replace the film cap. These square ones fits better on one side. I made a case for it so the idea is to clip it on to the headphone jack and the corner screw of the transformers so I dot have to drill any hole.


----------



## cebuboy

HTSkywalker said:


> So a 6AS7G would also also work ?
> How about the pre-amp tube, would 6SN7 fit with or without adapter ?


Yup 6AS7G works nicely and 6SN7 too with an adapter, I use the Garage 1217 adapter in mine.


----------



## wabibito

cebuboy said:


> Yup 6AS7G works nicely and 6SN7 too with an adapter, I use the Garage 1217 adapter in mine.


do you need to modify anything?  would the amp provide enough power?


----------



## skhan007

I believe the speedball mod and adapter are all you need for 6sn7.


----------



## cebuboy

wabibito said:


> do you need to modify anything?  would the amp provide enough power?


Speedball and adapter, you are good to go.


----------



## HTSkywalker

Good to know as I have lots of the Darkvoice tubes 6080, 6AS7G, 6SN7, dual 6J5 etc. and would love to use in a BHC, I believe the speedball is mandatory in any Crack no matter what.


----------



## JamieMcC

wabibito said:


> Next stop is replace the film cap. These square ones fits better on one side. I made a case for it so the idea is to clip it on to the headphone jack and the corner screw of the transformers so I dot have to drill any hole.



Very important you have good clearance around your capacitor terminals from the metal securing band and preferably insulate the connection as well otherwise there is a very real risk of your top plate becoming live if the capacitor moves even a milimetre or two during normal moving and handling movements.

Maybe it's just the angle of the pic but clearance looks pretty minimal from the picture particularly at either ends

Neat way of securing them other wise.


----------



## wabibito (May 14, 2021)

JamieMcC said:


> Very important you have good clearance around your capacitor terminals from the metal securing band and preferably insulate the connection as well otherwise there is a very real risk of your top plate becoming live if the capacitor moves even a milimetre or two during normal moving and handling movements.
> 
> Maybe it's just the angle of the pic but clearance looks pretty minimal from the picture particularly at either ends
> 
> Neat way of securing them other wise.yeah.



I plan to make the hole bigger and also heat shrink all the solder points there in case.


----------



## wabibito

Though this bring up another question, is it safe to heat shrink the solder point on the cap?


----------



## skhan007

OK, I bought a set of half-dome rubber feet for audio components. They do the job well. So, here are my quick observations after listening to:

Deep Purple - In Rock
AC/DC - For Those About to Rock
Aerosmith- Rocks
Rolling Stones- It's Only Rock n Roll
Hendrix- Stone Free

The tone is solid and heavy. Very heavy. Sometimes cold, but yet smooth and dense.


----------



## jonathan c

skhan007 said:


> OK, I bought a set of half-dome rubber feet for audio components. They do the job well. So, here are my quick observations after listening to:
> 
> Deep Purple - In Rock
> AC/DC - For Those About to Rock
> ...


I think that the heavy base + feet would really dampen any vibration....good for sound !


----------



## skhan007

That was the biggest motivation! The tube you see in the picture is actually quite sensitive to vibration and all is good now.


----------



## HTSkywalker

skhan007 said:


> That was the biggest motivation! The tube you see in the picture is actually quite sensitive to vibration and all is good now.


A dampening joint around the upper base part where the metal tray touch should kill any vibration


----------



## DeweyCH

Anyone have strong opinions on a 20k Alps Blue vs. a 50k Audio Note pot vs. a 20k eBay "DACT-style" stepped attenuator? I've got the attenuator in there now, and it works fine, but I don't particularly know what to expect in differences... and it takes me so long to swap a pot out that I can't remember specifically what I heard from the last one.

I am somewhat inclined to put the Audio Note in for the (stupid) reason that it's a solid shaft whereas my attenuator is a split knurled shaft... I know that's a fairly stupid reason, but there are many stupid reasons, and this one is mine.


----------



## hikaru12

DeweyCH said:


> Anyone have strong opinions on a 20k Alps Blue vs. a 50k Audio Note pot vs. a 20k eBay "DACT-style" stepped attenuator? I've got the attenuator in there now, and it works fine, but I don't particularly know what to expect in differences... and it takes me so long to swap a pot out that I can't remember specifically what I heard from the last one.
> 
> I am somewhat inclined to put the Audio Note in for the (stupid) reason that it's a solid shaft whereas my attenuator is a split knurled shaft... I know that's a fairly stupid reason, but there are many stupid reasons, and this one is mine.



I have the Audio Note in mine and I find it better detailed and a more smoother pot than the Blue Alps. Highly recommended. It's not that expensive either.


----------



## DeweyCH

hikaru12 said:


> I have the Audio Note in mine and I find it better detailed and a more smoother pot than the Blue Alps. Highly recommended. It's not that expensive either.


Yeah I was surprised it was so close in price to the Alps.


----------



## DeweyCH

Had to Dremel a bit of the top plate to get it to fit, but the Audio Note is in and sounds really good. I love the design with the solder lugs. HUGE solder lugs. Very handy for getting multiple grounding cables attached to the pot. Like the stock pot, but better sounding.

Really smooth and great balance, even down to super low volume. It's 100k, not 50k as I initially wrote. All in all, great pot. Better than the eBay attenuators.


----------



## DenverW

For the audio note pots, what’s the difference between the stereo balance and stereo volume 100k pots?


----------



## wabibito

DeweyCH said:


> Had to Dremel a bit of the top plate to get it to fit, but the Audio Note is in and sounds really good. I love the design with the solder lugs. HUGE solder lugs. Very handy for getting multiple grounding cables attached to the pot. Like the stock pot, but better sounding.
> 
> Really smooth and great balance, even down to super low volume. It's 100k, not 50k as I initially wrote. All in all, great pot. Better than the eBay attenuators.


I have the blue alps and the eBay dact type with D shaft. Do you know a good place to buy the Audio Note in the US?


----------



## DeweyCH

wabibito said:


> I have the blue alps and the eBay dact type with D shaft. Do you know a good place to buy the Audio Note in the US?


I bought mine from partsconnexion.


----------



## DeweyCH

DenverW said:


> For the audio note pots, what’s the difference between the stereo balance and stereo volume 100k pots?


Volume is for volume, balance is a L/R balance. Don't buy the stereo balance pot.


----------



## DenverW

DeweyCH said:


> Volume is for volume, balance is a L/R balance. Don't buy the stereo balance pot.



You make a lot of sense with this .


----------



## DeweyCH

DenverW said:


> You make a lot of sense with this .


Oh dear, I must be ill...


----------



## HTSkywalker

Anyone tried the BHC with Focal cans ?


----------



## Tom-s (May 21, 2021)

Enjoying my Bottlehead Crack with my oldest type 6F8G.

An early round plate Sylvania with engraved base from October 1937. Output is a Telefunken 6080.
"Early" since the first mention of 6F8G is September 1937 according to this site: https://www.radiomuseum.org/tubes/tube_6f8g.html

Sounds great; test NOS. No sign of any first production run issues 

Edit: some more reading material http://www.hifi-tunes.com/the-evolution-of-a-constant-glow-in-high-fidelity/


----------



## DenverW

HTSkywalker said:


> Anyone tried the BHC with Focal cans ?



Not a good match.  The lower impedance of focal cans don't pair well with OTL amps.  Look for headphones with higher impedance, such as beyerdynamic and sennheiser.


----------



## jonathan c

DenverW said:


> Not a good match.  The lower impedance of focal cans don't pair well with OTL amps.  Look for headphones with higher impedance, such as beyerdynamic and sennheiser.


Agreed! Beyer DT1770 pro, 250 ohms; Beyer DT880, 250/600 ohms, Senn HD600, 300 ohms; ZMF Auteur, 300 ohms...


----------



## DenverW

jonathan c said:


> Agreed! Beyer DT1770 pro, 250 ohms; Beyer DT880, 250/600 ohms, Senn HD600, 300 ohms; ZMF Auteur, 300 ohms...



Audio technica r70x...but honestly the crack's soulmate is the sennheiser HD line, all the way up to the 800.


----------



## DenverW

Little bird just told me that Bottlehead raised their prices.  I can confirm.  Makes me glad I already have some BH amps.  If only I hadn’t JUST sold my mainline .


----------



## wabibito (May 22, 2021)

I have a question about the Belton 9 Pin socket.  I bought one of these and it seems like it doesn't have the center ground pin.  How do i wire the LEDs etc to the crack?  Can i just use a screw and act as ground?


----------



## hikaru12

DenverW said:


> I would consider other options for sure, especially since you already have two great tubes.  Honestly, two VERY solid tubes.  For me, tube rolling is something I have to control myself on.  I want to try EVERYTHING!  But the reality is that most tubes would just end up sitting on a shelf or being resold because there are only two tubs in the crack at any given time.
> 
> So after trying pretty much everything, I limit myself.  I try to follow a few rules.  I try not to buy multiples of a particular tube, especially if I havent heard it, because matched pairs can cost more than buying individually, and because one of the two isn't getting used.  There is a temptation to have a 'spare' but these tubes last a pretty long time, and unless it becomes my favorite I don't need a spare.  So basically I try not to buy tubes now unless I think there is a legitimate chance it will replace a current favorite, or at least add a different enough sound that I can justify having it.
> 
> ...



I've pretty much maxed out my Crack now at this point and wanted to get your impressions on the Crackatowa (if you still have it)? Is it a significant upgrade over the Crack? I'm most concerned with the bass. I want slam! Air and separation being secondary concerns. How would you rate it in that department compared to the BHC?


----------



## DenverW

hikaru12 said:


> I've pretty much maxed out my Crack now at this point and wanted to get your impressions on the Crackatowa (if you still have it)? Is it a significant upgrade over the Crack? I'm most concerned with the bass. I want slam! Air and separation being secondary concerns. How would you rate it in that department compared to the BHC?



My crack was about as pumped as it could get, and I preferred my mainline amp so I sold it.

I prefer my crackatwoa vs the mainline amp just for some of the things you mentioned.  While slightly less technical, the impact, slam, and FEEL of it are more to my tastes overall.  Can’t go wrong with a c2a or mainline, but I prefer the former.


----------



## hikaru12

DenverW said:


> My crack was about as pumped as it could get, and I preferred my mainline amp so I sold it.
> 
> I prefer my crackatwoa vs the mainline amp just for some of the things you mentioned.  While slightly less technical, the impact, slam, and FEEL of it are more to my tastes overall.  Can’t go wrong with a c2a or mainline, but I prefer the former.



That’s awesome. Glad to hear it. Do you feel like the slam was better on the C2A vs your regular maxed out Crack?


----------



## DenverW

hikaru12 said:


> That’s awesome. Glad to hear it. Do you feel like the slam was better on the C2A vs your regular maxed out Crack?



Yes, noticeably.  Now that could be a function of better slam, or the blacker background and better separation giving the appearance of better slam, or both.


----------



## davehg (Jun 2, 2021)

Not a Crackhead, but a pic of the Bottlehead BeePree 300b pre amp in a custom wood case. These have Teflon Vcaps, stepped attenuators, and buffered outputs. Just need to settle on a stain to match the pretty copper hammertone finish but not black.


----------



## raindownthunda

davehg said:


> Not a Crackhead, but a pic of the Bottlehead BeePree 300b pre amp in a custom wood case. These have Teflon Vcaps, stepped attenuators, and buffered outputs. Just need to settle on a stain to match the pretty copper hammertone finish but not black.



Very nice work with the custom case! The tapered base with the slim bezel around the top plate looks very refined. Can’t wait to see what it looks like when finished. I’ve heard good things about the Osmo Hard Wax if you want to keep that natural look.


----------



## davehg

Thanks. I think the BeePre2 really demands a case with more heft than the stock one. My neighbor had some down time and mad woodworking skills, so he cad designed this and crafted it by hand. I love these types of joints and he had the idea for the tapered top.

I‘ve another friend who builds guitars and his most recent one has a cool wengewood style stain that is interesting.


----------



## Stillhart (Jun 3, 2021)

Well, it's not the prettiest Crack ever built, and it's CERTAINLY not the quickest, but I finally got around to completing my half-assembled Crack and I'm pretty happy about it.  I haven't tested it much yet as I need to make some space for it near my current rig, but initial impressions are pretty positive given the price of the amp kit. 

And it worked on the first try!  I found one bad solder during the resistance testing that was quickly fixed but otherwise no issues.  I messed up the staining by not sanding away enough of the glue at the corners.  And I messed up the paint on the top by flipping it over to work on before it was 100% dry (you can see where some pain came off around the edges where it touched the wooden case).  But all that's just personality if you ask me.  

Gonna be using it with my HD800's and my (soon to arrive) ZMF Auteur.  Source-wise, I'll be experimenting to see if my warmish R2R DAC-19 is too much warmth or if I should use the Mojo with it instead.

Eventually I'll install the Speedball kit (I want to get used to the stock sound first though) and think about tube rolling.  Anyone know if it's safe to use my tubes from my Project Solstice with the Crack?


----------



## skhan007

ZMF Auteur + BHC Speedy = Perfect Match!!


----------



## HTSkywalker

DenverW said:


> Not a good match.  The lower impedance of focal cans don't pair well with OTL amps.  Look for headphones with higher impedance, such as beyerdynamic and sennheiser.


The DV is listed to handle 60 Ohms and up but am pretty sure it's not driving the cans to its full potential


----------



## HTSkywalker

jonathan c said:


> Agreed! Beyer DT1770 pro, 250 ohms; Beyer DT880, 250/600 ohms, Senn HD600, 300 ohms; ZMF Auteur, 300 ohms...


how about the DT 990 600 OHMS ?


----------



## HTSkywalker

DenverW said:


> Little bird just told me that Bottlehead raised their prices.  I can confirm.  Makes me glad I already have some BH amps.  If only I hadn’t JUST sold my mainline .


In fact most companies raised their prices due to the components shortage related to the COVID lockdown


----------



## HTSkywalker

davehg said:


> Not a Crackhead, but a pic of the Bottlehead BeePree 300b pre amp in a custom wood case. These have Teflon Vcaps, stepped attenuators, and buffered outputs. Just need to settle on a stain to match the pretty copper hammertone finish but not black.


The wood texture is beautiful, which wood is that ?


----------



## davehg

HTSkywalker said:


> The wood texture is beautiful, which wood is that ?


A Canadian snow ash if I recall. Nice grain. They typically make bats out of it.


----------



## HTSkywalker

davehg said:


> A Canadian snow ash if I recall. Nice grain. They typically make bats out of it.


Very nice indeed 👍


----------



## wabibito (Jun 6, 2021)

The last two mods for the amp.
Cap bypass and the film cap.
After a couple tries. Finally made the box for the two film caps. I had to redo some of the wire to rotate the headphone jack around. This so it won’t risk a short. The box is clip on the headphone jack and the corner screw of the transformer.


----------



## HTSkywalker

wabibito said:


> The last two mods for the amp.
> Cap bypass and the film cap.
> After a couple tries. Finally made the box for the two film caps. I had to redo some of the wire to rotate the headphone jack around. This so it won’t risk a short. The box is clip on the headphone jack and the corner screw of the transformer.


Tell us about the results when it's up and running, lots of work done there


----------



## wabibito (Jun 7, 2021)

HTSkywalker said:


> Tell us about the results when it's up and running, lots of work done there


It sounds fantastic.  It actually like it better than the Eddie Current ZDT Jr that i shielded not too long ago.  The amp is dead silence with both stock tube set and the 6N13S + 6SN7 (with garage1217 adapter).  Too bad this amp is not mine lolz.
Here is the list of mod done so far:
- Speedball
- Ground the earth with a pair of uf4007 rectifier
- Choke
- Cree Diodes
- Panasonic Square Film Caps
- Cap Bypass for all


----------



## HTSkywalker

wabibito said:


> It sounds fantastic.  It actually like it better than the Eddie Current ZDT Jr that i shielded not too long ago.  The amp is dead silence with both stock tube set and the 6N13S + 6SN7 (with garage1217 adapter).  Too bad this amp is not mine lolz.
> Here is the list of mod done so far:
> - Speedball
> - Ground the earth with a pair of uf4007 rectifier
> ...


Were you able to make it handle cans with impedance lower than 150-200 Ohms ? am curious as a Focal owner


----------



## wabibito

HTSkywalker said:


> Were you able to make it handle cans with impedance lower than 150-200 Ohms ? am curious as a Focal owner


I will test it out with my focal elegia later tonight when i am home.  let see how it will sound.


----------



## wabibito (Jun 7, 2021)

HTSkywalker said:


> Were you able to make it handle cans with impedance lower than 150-200 Ohms ? am curious as a Focal owner


I did a quick listening test for the focal elegia and it works fine.  The off volume is at 6 o'clock.  anything pass 9 o'clock is too loud for my taste with this headphone.  It does seems to have a little more punch than my 650.  I also test with the 80hm dt770, that also works fine.  It seems like the treble is toned down a bit for the dt770 with this amp, which is a good thing for me =).

I tested this via Ares II Dac.


----------



## HTSkywalker

wabibito said:


> I did a quick listening test for the focal elegia and it works fine.  The off volume is at 6 o'clock.  anything pass 9 o'clock is too loud for my taste with this headphone.  It does seems to have a little more punch than my 650.  I also test with the 80hm dt770, that also works fine.  It seems like the treble is toned down a bit for the dt770 with this amp, which is a good thing for me =).
> 
> I tested this via Ares II Dac.


Sounds good with the Elegia 👍


----------



## wabibito

I see quite a few people have custom metal panel with larger size,  I wonder where do you guys order those?


----------



## jonathan c

Are there any Bottlehead designs or variants, including the Crack, that use the 12AT7 tube?


----------



## HTSkywalker

How about using using  6SN7 tubes in a BHC ? 
It seems we can also use 6922 tubes but may need an adapter of sort.


----------



## DenverW

HTSkywalker said:


> How about using using  6SN7 tubes in a BHC ?
> It seems we can also use 6922 tubes but may need an adapter of sort.



6SN7 tubes are very common, with a 12au7 adapter.  Make sure you have speedball installed, and make sure not to use it in the 6080 socket.


----------



## HTSkywalker

DenverW said:


> 6SN7 tubes are very common, with a 12au7 adapter.  Make sure you have speedball installed, and make sure not to use it in the 6080 socket.


Speedball is mandatory for 6SN7 ?


----------



## Tom-s

wabibito said:


> I see quite a few people have custom metal panel with larger size,  I wonder where do you guys order those?



There's very little Cracks with a bigger top chassis. Look into the Crack A Two A; as it was designed with a bigger top plate. To allow room for more fancy (big) output capacitors.



jonathan c said:


> Are there any Bottlehead designs or variants, including the Crack, that use the 12AT7 tube?



The Bottlehead Stereomour amplifier uses 12AT7 tubes as drivers for the 2A3 power tubes with great succes. Half of the 12AT7 is used as a shunt regulator for optimal performance of the halve that is driving the 2A3. 



HTSkywalker said:


> How about using using  6SN7 tubes in a BHC ?
> It seems we can also use 6922 tubes but may need an adapter of sort.



One could use the 6SN7 without the Speedball. As the 6SN7 is very close to a 12AU7 electrically. 
The 6922 is very different. I'd not recommend using it in the stock Crack or with a Speedball without further modifications. One would need to modify the wiring on the socket and R1 on the Speedball allowing more current like 6-8mA for better performance / match to the Crack. Then you'd still have to deal with the greater output / gain from the 6922. A Crack that's modified to use 12BH7 could also use 6922 with an adapter.


----------



## wabibito

Any one heard of this brand of cap?  A local shop has these for 5 dollars each.
75 UF 600 V 5% C G Electronics MKP Metalized Polypropylene Capacitor


----------



## HTSkywalker

wabibito said:


> Any one heard of this brand of cap?  A local shop has these for 5 dollars each.
> 75 UF 600 V 5% C G Electronics MKP Metalized Polypropylene Capacitor


That's too big (size wise)


----------



## Bimbleton

Does anyone have any experience buying a built, pre-owned Bottlehead Crack? Do these things survive the journey, or do the connections come apart during travel?


----------



## jonathan c

Bimbleton said:


> Does anyone have any experience buying a built, pre-owned Bottlehead Crack? Do these things survive the journey, or do the connections come apart during travel?


I have that experience. I bought a built-to-order BHC+speedball from HeadAmp Builder (James C, Los Angeles CA). The build was gorgeous and the packing was meticulous! Everything was intact and worked perfectly: I live in southwestern Pennsylvania. [FYI, my initial contact with HeadAmp Builder was through Etsy.]


----------



## CaptainFantastic

jonathan c said:


> I have that experience. I bought a built-to-order BHC+speedball from HeadAmp Builder (James C, Los Angeles CA). The build was gorgeous and the packing was meticulous! Everything was intact and worked perfectly: I live in southwestern Pennsylvania. [FYI, my initial contact with HeadAmp Builder was through Etsy.]



I had the same experience intra-EU with a very, very nice packing job from a fellow Head-Fier. 

I will say that indeed it does require that meticulous packing effort. I think I read above (a few months back) of someone who bought a used BHC and it arrived slightly damaged due to shipping. So I would arrange carefully with the seller about shipping arrangements.


----------



## wabibito

Bimbleton said:


> Does anyone have any experience buying a built, pre-owned Bottlehead Crack? Do these things survive the journey, or do the connections come apart during travel?


I bought a prebuilt crack on eBay not too long ago and when it came the plate was bent and the wood base fall aparts. The seller use to small of a box and USPS seems like they dropkick the box.
My friend bought a prebuilt S.E.X which is larger and it came in perfect condition via UPS.


----------



## wabibito

Finally finished my friend amp with the last mod he requested. Replacing the last power supply with film cap. Mounting was a bit challenge so I made another box. Everything works outs stacking via the two holes on the face plate.


----------



## DenverW

Bimbleton said:


> Does anyone have any experience buying a built, pre-owned Bottlehead Crack? Do these things survive the journey, or do the connections come apart during travel?



So I’ve received and shipped multiple Bottlehead amps.  Most have been fine. I did receive one unit that was in rough shape: the frame had broken, wires had come loose, screws had fallen out... The sender had made a pretty big mistake by sending it with the faceplate upside down, so the entire thing rested on the internal components.

So Bottlehead has some good instructions on shipping.  You wrap the amp with bubble tape first horizontally then vertically.  Fill a box with packing peanuts and rest the amp upside down so it’s laying on the top plate with the inside facing up.  Obviously there are no tubes in it!

I think there should be good instructions on the website to share with a seller.

Finally, if you’ve never built a kit be wary of buying.  If something goes wrong you won’t know what to do.  My first kit was purchased instead of built, so I spun my wheels for ages on something as simple as a blown fuse.

The recent kit I bought that arrived mangled I was able to repair successfully!  Build one first if you are able!


----------



## Bimbleton

Thank you all for the advice. My hesitancy is that the cost of the unit has increased, and I've heard I'll need $150+ of equipment to even build the thing. Is there any truth to the latter -- do you really need $150 of equipment to build one?


----------



## DenverW

Bimbleton said:


> Thank you all for the advice. My hesitancy is that the cost of the unit has increased, and I've heard I'll need $150+ of equipment to even build the thing. Is there any truth to the latter -- do you really need $150 of equipment to build one?



You will need a soldering station, solder, wire strippers, needle nose pliers...perhaps a helping hands, magnifying glass if you’re old like me..

someone else can chime in if I’m forgetting something.  So yeah, the components cost.  I will say that I’ve used all of the stuff from my first build to do plenty of other diy projects, so it’s not just an added cost onto my first crack.

Besides, if you want to upgrade a component, or if something happens you need to fix, how will you do that?


----------



## cddc

DenverW said:


> You will need a soldering station, solder, wire strippers, needle nose pliers...perhaps a helping hands, magnifying glass if you’re old like me..
> 
> someone else can chime in if I’m forgetting something.  So yeah, the components cost.  I will say that I’ve used all of the stuff from my first build to do plenty of other diy projects, so it’s not just an added cost onto my first crack.
> 
> Besides, if you want to upgrade a component, or if something happens you need to fix, how will you do that?



Agree, I will add that you don't have to use wire strippers if you know how to strip the wires with a blade, though using a blade can potentially leave some cuts on the copper if you apply too much force (not a big problem at all). But wire strippers work the best, and I do have one myself. So all you need is a soldering iron and some solder, and needle nose pliers to bend the wires, maybe $20 tools in total if you really want to go cheap, that's it, you can build the kit if you follow carefully the Bottlehead instruction, even if you have no experience at all in electronics. Some auxiliary equipments might help if you have them, like wire strippers, digital multi-meter, etc.

The major part of the fun from Crack is coming from building it by yourself. You can learn some thing about the project and be proud of it, as Doc B. said. If you build the Crack by yourself and you want to do some mods later, you'll know where to start; and if there is any problem, you can possibly know how to solve them (just like what @DenverW did) instead of having to send the amp to some "amp doctors".

If you pay hundreds of $$$ to some Crack leech to build it, then you lose the major part of fun from the Crack project. And if there's anything going wrong inside, you will have no idea where it is. Your life and tubes can be jeopardized if you happen to find some charlatan to build the Crack for you.


----------



## DenverW

Cddc got another one: you must have a multimeter.  I got a cheap one from Amazon from elekcity that works just fine.


----------



## wabibito (Jun 22, 2021)

DenverW said:


> You will need a soldering station, solder, wire strippers, needle nose pliers...perhaps a helping hands, magnifying glass if you’re old like me..
> 
> someone else can chime in if I’m forgetting something.  So yeah, the components cost.  I will say that I’ve used all of the stuff from my first build to do plenty of other diy projects, so it’s not just an added cost onto my first crack.
> 
> Besides, if you want to upgrade a component, or if something happens you need to fix, how will you do that?



A fancy helping hand isn't really needed.  I got myself a cheap 30 dollars soldering station (on sale on amazon) with two clips on the side and it been working great building my friend's Crack.  that comes with solder suction pen etc.  Also for wire strippers, i am using one of these and it on sale for 18 dollars right now.

https://www.amazon.com/gp/product/B...800bc2ead178cde80INT&smid=ATVPDKIKX0DER&psc=1

As for upgrading parts, I would build the crack first and upgrade on top of it.  Most of these parts it is not easy to damage, it just take time to unsolder and resolder.  The tricky part will be the led in the 9pin tube.

One thing really help me is i spent a lot of time looking at people build pictures and reading the sticky on the crack official forum.  this way you are familiar which what goes where and learn on how to organizing things.


----------



## cddc

I think folks can find some cheap $10-ish soldering iron from HomeDepot, though a fancy soldering station works better.

Building a Crack by yourself is not at all difficult IMHO, the Bottlehead step-by-step instruction is well written and easy to follow, just follow the instruction carefully and anyone can build a Crack.

Here is a great video from our old friend Tyll (InnerFidelity), in which he shows how easy it is to build a Crack:


----------



## Mightygrey

I'll leave a comment here that as someone who'd never used so much as a soldering iron before ordering my Crack, it was pretty easy to figure out. But, it was without a doubt one of the most satisfying things I've ever done. Well worth it.


----------



## Bimbleton

Thanks for all the responses y'all. Good combo with a ZMF Aeolus? At least that's what the Aeolus folks told me.


----------



## Mightygrey

Bimbleton said:


> Thanks for all the responses y'all. Good combo with a ZMF Aeolus? At least that's what the Aeolus folks told me.


It's a terrific pairing with all ZMF dynamics.


----------



## L0rdGwyn

Bimbleton said:


> Thank you all for the advice. My hesitancy is that the cost of the unit has increased, and I've heard I'll need $150+ of equipment to even build the thing. Is there any truth to the latter -- do you really need $150 of equipment to build one?



If you enjoy the experience, you will then have much of what you need for other DIY projects  how far down the rabbit hole you go is up to you, but you could also build your own headphone cables, for instance.


----------



## Mightygrey

L0rdGwyn said:


> If you enjoy the experience, you will then have much of what you need for other DIY projects  how far down the rabbit hole you go is up to you, but you could also build your own headphone cables, for instance.


I've definitely caught the DIY bug since building my Crack and I've picked-up some invaluable skills in the process. I've built several cables, which can be done pretty affordably simply by sourcing parts from Aliexpress. I've also modded more than the odd Grado to make their cables detachable too.


----------



## DenverW

L0rdGwyn said:


> If you enjoy the experience, you will then have much of what you need for other DIY projects  how far down the rabbit hole you go is up to you, but you could also build your own headphone cables, for instance.



So true!  From crack to crack mods to DIY alpha dogs to cables to rewiring Sony z7 to crackatwoa!  It’s a gateway drug to making everything sound better!


----------



## cddc

DenverW said:


> gateway drug to making everything sound better!


----------



## L0rdGwyn

Yes!  And if you take the time to learn about the circuit, you might even start on your own amplifier designs!  Just takes a lot of reading a learning.

Sorry in advance since I've probably reposted it like five times, but I sort of miss my Crackatwoa lol I spent an absurd amount of time polishing that top plate...never again.


----------



## CaptainFantastic

L0rdGwyn said:


> Yes!  And if you take the time to learn about the circuit, you might even start on your own amplifier designs!  Just takes a lot of reading a learning.
> 
> Sorry in advance since I've probably reposted it like five times, but I sort of miss my Crackatwoa lol I spent an absurd amount of time polishing that top plate...never again.



Wow. How did you achieve that? Is that the stock top plate and you just went at it? Didn't even know it was possible.

And why go on and sell it after that?  I can picture what those tubes and their reflection look like in the evening...


----------



## L0rdGwyn

CaptainFantastic said:


> Wow. How did you achieve that? Is that the stock top plate and you just went at it? Didn't even know it was possible.
> 
> And why go on and sell it after that?  I can picture what those tubes and their reflection look like in the evening...



Yeah it's the stock top plate.  Need to sand the surface down to a fine grit, then use buffing compound and a buffing wheel to get the mirror finish.  Aluminum is a soft metal though, so the surface is very susceptible to scratches after polishing, which can drive you crazy LOL.  I design my own amps now and only have so much space, so it had to go.


----------



## Bimbleton

L0rdGwyn said:


> Yes!  And if you take the time to learn about the circuit, you might even start on your own amplifier designs!  Just takes a lot of reading a learning.
> 
> Sorry in advance since I've probably reposted it like five times, but I sort of miss my Crackatwoa lol I spent an absurd amount of time polishing that top plate...never again.


I think that's the most gorgeous Crack I've ever seen, holy cow... Imagine the reflected glow of those tubes!


----------



## jonathan c

Bimbleton said:


> I think that's the most gorgeous Crack I've ever seen, holy cow…


Oops 😬…


----------



## L0rdGwyn

A more durable approach to making a top plate like above is to get it chrome-plated at a shop.


----------



## HTSkywalker

jonathan c said:


> I have that experience. I bought a built-to-order BHC+speedball from HeadAmp Builder (James C, Los Angeles CA). The build was gorgeous and the packing was meticulous! Everything was intact and worked perfectly: I live in southwestern Pennsylvania. [FYI, my initial contact with HeadAmp Builder was through Etsy.]


But that defies the DIY concept and fun 😨😨


----------



## HTSkywalker

Bimbleton said:


> Thank you all for the advice. My hesitancy is that the cost of the unit has increased, and I've heard I'll need $150+ of equipment to even build the thing. Is there any truth to the latter -- do you really need $150 of equipment to build one?


Just the daily tools in your workshop, nothing expensive.


----------



## HTSkywalker

cddc said:


> I think folks can find some cheap $10-ish soldering iron from HomeDepot, though a fancy soldering station works better.
> 
> Building a Crack by yourself is not at all difficult IMHO, the Bottlehead step-by-step instruction is well written and easy to follow, just follow the instruction carefully and anyone can build a Crack.
> 
> Here is a great video from our old friend Tyll (InnerFidelity), in which he shows how easy it is to build a Crack:



Make sure to use good solder, makes all the difference.


----------



## HTSkywalker

Mightygrey said:


> I'll leave a comment here that as someone who'd never used so much as a soldering iron before ordering my Crack, it was pretty easy to figure out. But, it was without a doubt one of the most satisfying things I've ever done. Well worth it.


especially the first time you fire it up and it's singing 🙂


----------



## jonathan c

HTSkywalker said:


> especially the first time you fire it up and it's singing 🙂


…unlike a DarkVoice…


----------



## jonathan c

Overall BHC+speedball questions: Can a 12AT7 be used in lieu of the 12AU7? Is that too high an amplification factor? Could a less powerful version of a 6080 be used to allow for the use of a 12AT7?


----------



## HTSkywalker

L0rdGwyn said:


> Yes!  And if you take the time to learn about the circuit, you might even start on your own amplifier designs!  Just takes a lot of reading a learning.
> 
> Sorry in advance since I've probably reposted it like five times, but I sort of miss my Crackatwoa lol I spent an absurd amount of time polishing that top plate...never again.


Well the polishing did pay 👌👌


----------



## HTSkywalker

jonathan c said:


> …unlike a DarkVoice…


The Darkvoice starts and keeps on humming for a lifetime (not a long one though) lol


----------



## DenverW

jonathan c said:


> Overall BHC+speedball questions: Can a 12AT7 be used in lieu of the 12AU7? Is that too high an amplification factor? Could a less powerful version of a 6080 be used to allow for the use of a 12AT7?



The 12AT7 is not compatible to my knowledge.


----------



## tintinsnowydog

The 12AT7 has same pinout and works, but has much higher gain and a different operating point. If you have one on hand to try hear how it sounds by all means, but wouldn't be a tube to seek out for this amp specifically.


----------



## L0rdGwyn

jonathan c said:


> Could a less powerful version of a 6080 be used to allow for the use of a 12AT7?



So in the BHC and similar cathode follower output OTLs, the 6AS7G does not provide any voltage gain.  The "ideal" cathode follower operates at unity gain, a gain of 1, in reality it is less than one, so you actually _lose_ some gain from a cathode follower.  It might be 0.8 or so.  That is why two tubes that have differing amplification factors, like 6AS7G and 5998, produce roughly the same volume with the same driver tube in the BHC, since they are both cathode followers.  A cathode follower is a buffer circuit, its purpose is to provide an easy load from the previous stage and a low output impedance - its sole purpose in a cathode follower OTL is to provide a sufficiently low output impedance to properly drive headphones.  Tubes have their limitations though and the output impedance is still relatively high compared to something like a MOSFET buffer which has a much, much higher transconductance.  The equivalent circuit to a cathode follower in MOSFET terms is a source follower.  For those that are averse to negative feedback, you will have to get rid of your cathode follower OTLs - a cathode follower operates at 100% local, internal negative feedback, the reason they have low output impedance, low distortion, and no gain


----------



## cddc

I have mixed feelings about the negative feedback (NFB) 

I do read some folks do not like NFB. Though NFB lowers distortion and improves various measurements, some folks think NFB reduces the speed of the circuit, hence  transient is more sluggish. Imagining a boxer is trying to hit the punchbag with his fist, but suddenly some heavy gel (like NFB) fills the space between his fist and the punchbag, now the more force the boxer applies to his fist the more pushback from the gel his fist will receive, so he'll never hit the punchbag as fast as if there's no such drag from the gel.

But a cathode follower OTL that operates at 100% local internal NFB does sound very good, just like the BHC. So I think I have no problem with some local NFB, besides, the cathode resistor always comes with some NFB if not bypassed. The global NFB with some flying leads is somewhat more difficult for me to swallow though, but in the end if the implementation does sound very good, I think I'll still be fine with it.

I have never spent too much time on SS components, but I remember I read that BJTs and Mosfets have worse linearity than tubes, so there is always lots of NFB used in SS amplification circuits to improve distortion.


----------



## L0rdGwyn

@cddc it is all about implementation!  My main system amplifier uses some small amount of local NFB to lower the output impedance, it is very dynamic!  I think the bad reputation comes from poor circuits that use very high degrees of global NFB.  Yes, BJT and MOSFETs have characteristics similar to pentodes and often use negative feedback.  Used as a source follower, a MOSFET also operates at 100% NFB, so very similar characteristics to a cathode follower - low distortion, low output impedance, no gain.  I use a SiC MOSFET source follower in another amplifier, a hybrid design with a tube gain stage.  They can sound quite good if done well!  There is one transistor that is very interesting, the VFET (aka SIT), which actually has triode-like curves, making it very much usable in class A designs that do not use any NFB, much like class A tube amplifiers.  These are popular right now in the DIY community, popularized by Nelson Pass in his First Watt line, but they are all NOS and numbers are dwindling.  I bought some so I have them around when I am ready to build something with them 




And the curves!  Like from a triode datasheet.


----------



## Wes S

Just in case any BHC owners are looking for some amazing and rare driver tubes, I have a few listed in the classifieds.  I have several really nice early Hamburg Valvo Long Plates listed, that were one of my favorite tubes in the BHC.

Cheers!


----------



## wabibito

Does anyone know how to replace the PT-3 from the crack with a PT-7?  I heard this is possible but PT7 is missing the terminal 9.


----------



## CaptainFantastic (Jul 5, 2021)

In some of the more recent posts above there have been queries on whether it is too risky to buy an already assembled BHC. The risks would generally be build quality and safety of the unit during shipment. I would like to share my very positive experience with a BHC project I pursued with Tom-s, a fellow member of these forums. As we are both based in Benelux, this is more directed toward the European crowd.

For those short on time *the summary* in one paragraph is this:

It was a very fun project where we collaborated in picking the mods and options available at all points along the way. Tom did the build, the painting of the steel plate and a great super-safe shipping job. I could not be happier with the result. If you are in the EU and interested in getting a Crack built, send Tom a message, depending on his availability and what you’re looking for it might lead to an interesting and engaging project like mine was. And you will have a great sounding tube amp that outperforms what else I’ve heard in the sub-1k range.

The details:

I have zero experience with soldering and do-it-yourself projects in electronics. So despite being very interested in what the BHC has to offer, I always kept away knowing that I would not entertain the idea of building one myself. I was interested in the BHC because my stable of headphones is perfectly suited for it – mainly 300Ω Sennheisers and a ZMF, soon two.

My goal has been for a while to have a high performing solid state amp and a very enjoyable tube amp. For the tube amp I had the Woo Audio WA3, an amp I enjoyed a lot and acquired some very good tubes for. In fact, I enjoyed it so much that I owned two of them. And it was in the context of tubes for the WA3 that I started speaking with Tom. What this particular BHC-build was promising over the stock WA3 was hand-picked upgraded components and therefore the hope to take the performance up a notch or even two in the same compact format.

We discussed the build in detail and chose the mods together. One particular feature I wanted to have was the ability to use my E88CC tubes. Tom therefore installed a switch that allows three different current settings for the driver tube bias - to optimize it for 6SN7 (12AU7, 6J5, 76) first and E88CC (12BH7) second. We also went with a 6SN7 socket as standard, a nice mod since most of the time I run 6SN7s not E88CCs or 12AU7s.

The other main mods were:

Audio Grade 21 steps DACT Type Stepped Attenuator
Mundorf MCap Classic 250V 100 uF ±5%
Hammond Choke 158M
Schottky diodes
PRP Audio Metal Film Resistors
and upgraded internal wiring to silver plated solid core copper
Tom completed the build over the course of something like two-three weeks, which included the painting of the plate to the color/finish I chose and also did a few days of testing that everything works well (note – I did the wood treatment myself, hence I am responsible for the imperfections on that front as seen in the pictures, but it was still enjoyable/personal and I now know what I would do slightly differently next time). This project was never about getting it done quickly. We knew from ordering the parts from the U.S., to choosing and sourcing the mods, to the build, that this would be about taking it easy and advancing with the right decisions and quality rather than speed.

The shipment from Tom to me required particular care to protect all the internal components. He used a cloth material wrapped/molded almost on the unit which ensured zero movement inside. It arrived in top shape and (out of an abundance of caution) we even did a one hour video session together where I ran through a number of tests of the unit with a multimeter at Tom’s direction to ensure nothing moved somehow during shipping. Everything checked out.

So what are the results:

Almost 3x the tube rolling possibilities with 12AU7s and 6SN7s now added to my E88CCs.
A sense of ownership of a custom-built amp that is much greater than toward the off-the-shelf units.
Satisfying, rich sound with deeper impact while maintaining good clarity. It’s not the transparency and detail of the TT2, of course, but I listen to the TT2 50% of the time and to this great tube sound the other 50% of the time. As someone else said in the TT2 forum recently “audiophile terms are squishy” and “getting into the weeds with actual adjectives” sometimes promotes misunderstanding and blowback. So I won’t go deeper into this, but to say that if you are interested in the BHC you have surely researched it and know what it promises to deliver. Well, imagine that stock BHC very nicely upgraded as detailed above… even better.
Tube hum and microphonics depend on the tube, but I understand that sometimes the amp can accentuate the issues as well. I am very pleased that as we built it, this BHC sounds clean, even when running an E88CC tube.
Hope this “review” is helpful to others and a big thanks to Tom for the project.


----------



## HTSkywalker

CaptainFantastic said:


> In some of the more recent posts above there have been queries on whether it is too risky to buy an already assembled BHC. The risks would generally be build quality and safety of the unit during shipment. I would like to share my very positive experience with a BHC project I pursued with Tom-s, a fellow member of these forums. As we are both based in Benelux, this is more directed toward the European crowd.
> 
> For those short on time *the summary* in one paragraph is this:
> 
> ...


Good job there 👍


----------



## cddc

CaptainFantastic said:


> In some of the more recent posts above there have been queries on whether it is too risky to buy an already assembled BHC.



I thought you'd have talked a little bit about how your $200+ GEC 6AS7G got toasted on the already assembled BHC, as you started your article with the above statement. To my surprise, there is none.  

Before - clear glass:







After - smoked glass:


----------



## CaptainFantastic (Jul 5, 2021)

@cddc I didn't talk about it because this was about the amp, not about that particular tube. I bought two of those 6AS7Gs from Billington (so a trusted source - but they certainly didn't test them in amps), One did this, the other did not. None of my other power tubes had any issues and all testing showed it was the tube, not the amp. By the way, the tube works great still and I use it. It just looks "different".


----------



## CaptainFantastic

cddc said:


> I thought you'd have talked a little bit about how your $200+ GEC 6AS7G got toasted on the already assembled BHC, as you started your article with the above statement. To my surprise, there is none.
> 
> Before - clear glass:
> 
> ...



By the way, am I getting old, or the top picture is not mine. Did you own this particular tube before me?


----------



## cddc

CaptainFantastic said:


> By the way, am I getting old, or the top picture is not mine. Did you own this particular tube before me?



No, the top picture is from the web just for comparison, I have several GEC 6080's and A2293's, but I prefer 7236/5998/421A, so I don't want to go this route.


----------



## cddc

CaptainFantastic said:


> @cddc I didn't talk about it because this was about the amp, not about that particular tube. I bought two of those 6AS7Gs from Billington (so a trusted source - but they certainly didn't test them in amps), One did this, the other did not. None of my other power tubes had any issues and all testing showed it was the tube, not the amp. By the way, the tube works great still and I use it. It just looks "different".





So you're questioning a trusted source Billington not testing his tubes and hence sending you a faulty GEC 6AS7G? Have you thought about other possibilities?


----------



## CaptainFantastic

cddc said:


> So you're questioning a trusted source Billington not testing his tubes and hence sending you a faulty GEC 6AS7G? Have you thought about other possibilities?



No, I am not questioning Billington nor did I intend to suggest that above, the tube works as I said. I don't think any tube seller has time to test tubes in amps for hours.


----------



## cddc

Then, good luck...LOL


----------



## DenverW

@CaptainFantastic switch looks great.  I’ve been talking about putting one in for a while, and never manned up.


----------



## wabibito

Bought a cheap damaged basic crack that has broken based and bent top plate recently. In the process of fixing and restoring it. Deciding to build it a little different then the last one I build for my friend. I also using the BT-7 instead of the BT-3 so the wiring is a little different.


So far it sounds good. Time to order the mods.


----------



## Bonddam

Even though I didn't build my Crack it's still my favorite and decided to get the 6XX so I can use it. I originally had the Euphoria AE and Woo WA3 otl's and crack is my favorite.


----------



## Mightygrey

wabibito said:


> Bought a cheap damaged basic crack that has broken based and bent top plate recently. In the process of fixing and restoring it. Deciding to build it a little different then the last one I build for my friend. I also using the BT-7 instead of the BT-3 so the wiring is a little different.
> 
> 
> So far it sounds good. Time to order the mods.


Any tips on how to install the VU meters? Great job!


----------



## wabibito

Here is some of the pictures where I mount the meters and parts.  This is detachable so will allow me to take the amp and case apart.


----------



## Mightygrey

wabibito said:


> Here is some of the pictures where I mount the meters and parts.  This is detachable so will allow me to take the amp and case apart.


Really helpful, thanks mate. 

So, you need to attach the RCA L/R/G into the PCB board for the VU meters, and then connect the board directly to the power supply? Or, do you need to 'tap' the power supply elsewhere on the amp?


----------



## wabibito

Mightygrey said:


> Really helpful, thanks mate.
> 
> So, you need to attach the RCA L/R/G into the PCB board for the VU meters, and then connect the board directly to the power supply? Or, do you need to 'tap' the power supply elsewhere on the amp?


There are two cables that goes into the board. The three wire ones are rca. Then you see there is another one that run to the back where I have drilled a hole on the top plate for an external power plug. I am ordering a ac120v to 12v dc converter from amazon. Hopefully I can drive everything from the single power source.


----------



## wabibito

Mightygrey said:


> Really helpful, thanks mate.
> 
> So, you need to attach the RCA L/R/G into the PCB board for the VU meters, and then connect the board directly to the power supply? Or, do you need to 'tap' the power supply elsewhere on the amp?


Hey. The converter came. I replaced took it a part and replace the wires with the one came with the meter so it is cleaner install. I also replace the power L N wire with the same Teflon one I been using for the crack. It seems to fit perfectly under the choke. Here is the spec and picture if you decide to get one. Will test it out this weekend once I out everything back together and let you know.


----------



## wabibito

The power converter works fine.  I didn't experience any noise.


----------



## wabibito

almost done with all the mod.

It is getting a little crowded lolz. Also th double loop zip tie is a life saver.


----------



## Mightygrey

wabibito said:


> almost done with all the mod.
> 
> It is getting a little crowded lolz. Also th double loop zip tie is a life saver.


Nice work mate!


----------



## wabibito

Mightygrey said:


> Nice work mate!


Thanks. Glad I can salvage the damaged crack. Too bad the back speedball module is cracked.


----------



## skhan007

I really look forward to weekend mornings, when I don't have to think about work or life in general. I can put on my ZMF cans, warm up some tubes, and dive deep in to my music library. So stress relieving and a great escape. I'm going to be getting my basement finished in the coming weeks, so looking forward to a dedicated spot to set up my headphone amp setup. Right now, I'm listening on my guitar repair bench/counter. Love my BHC Speedy setup!!


----------



## Bonddam

wabibito said:


> almost done with all the mod.
> 
> It is getting a little crowded lolz. Also th double loop zip tie is a life saver.


Your internals look like a crossover. What magic are you creating by using different caps together?


----------



## wabibito

Bonddam said:


> Your internals look like a crossover. What magic are you creating by using different caps together?


I just simply replacing the existing cap with better film cap and by pass all of them. It sounds pretty good even without speedball. Well, 1/2 speedball as I don’t have the large board.


----------



## Bonddam

wabibito said:


> I just simply replacing the existing cap with better film cap and by pass all of them. It sounds pretty good even without speedball. Well, 1/2 speedball as I don’t have the large board.


Very nice. Like to see what it sounds like after 4-5 hundred hours.


----------



## wabibito

Bonddam said:


> Very nice. Like to see what it sounds like after 4-5 hundred hours.


That is a long time lolz.  I mainly listen to the DX300 DAP.


----------



## WaveTheory

I just posted a Crack review here: https://www.head-fi.org/showcase/bottlehead-crack-otl.12105/reviews


----------



## zizzyhead (Jul 23, 2021)

Here's another freshly minted build for the crackheads out there (with speedball upgrade) I used locally rough cut oak and planed it myself so that I could achieve this effect with the grain. Also used enamel paint with automotive catalytic clear coat and finished with multistage wet sanding, cutting and buffing. Electronics are stock. It really transformed my 650s and I love the sound.


----------



## GreenNeedle

zizzyhead said:


> Here's another freshly minted build for the creackheads out there (with speedball upgrade) I used locally rough cut oak and planed it myself so that I could achieve this effect with the grain. Also used enamel paint with automotive catalytic clear coat and finished with multistage wet sanding, cutting and buffing. Electronics are stock. It really transformed my 650s and I love the sound.


Although I wouldn't go for those colours the finish on yours is absolutely superb.


----------



## zizzyhead

GreenNeedle said:


> Although I wouldn't go for those colours the finish on yours is absolutely superb.


Thanks!


----------



## HTSkywalker

zizzyhead said:


> Here's another freshly minted build for the crackheads out there (with speedball upgrade) I used locally rough cut oak and planed it myself so that I could achieve this effect with the grain. Also used enamel paint with automotive catalytic clear coat and finished with multistage wet sanding, cutting and buffing. Electronics are stock. It really transformed my 650s and I love the sound.


Red looks gorgeous 👍


----------



## zizzyhead

Thanks!


----------



## Mightygrey

After spending a good year or so using a Sylvania 6SN7 (with Garage1217 adapter) for the input tube on my Crack + Speedball, I decided to go back to the stock 12AU7 to see how it sounded. I was surprised by how much it was an immediate step 'backwards' - overall lower dynamics, transparency, and a more congested soundstage. Tube rolling really is an interesting hobby.


----------



## Dude707Can

Please tell me more about the adapter and what tube are you pairing the Sylvania with?


----------



## Mightygrey

Dude707Can said:


> Please tell me more about the adapter and what tube are you pairing the Sylvania with?


The adapter is one of these. I'm using a Tung-Sol 5998 power tube.


----------



## blackdragon87

Looking to buy a completed one with speedball. please pm


----------



## HTSkywalker

Mightygrey said:


> The adapter is one of these. I'm using a Tung-Sol 5998 power tube.


The TS 5998 is one of my preferred tubes 👍👍


----------



## Mightygrey

HTSkywalker said:


> The TS 5998 is one of my preferred tubes 👍👍


Last one I'll ever need...unless my cats break it.


----------



## Dude707Can

Where is good place to get the TS at a reasonable price?


----------



## CaptainFantastic

Dude707Can said:


> Where is good place to get the TS at a reasonable price?



Honestly, only on eBay from time to time. You could get lucky and get a very good one for say 150 EUR/170USD. The prices can be random. I bought a perfect 5998 for about 120 USD from an Italian seller last year and now the same seller has one for 340 USD. But I also got a not so good specimen for 140 USD last year - useable but looks a bit beat up. So if you want to be 100% sure check with the sellers you trust and be prepared to pay more.

If you are determined, check via Hifishark/eBay regularly and if you see one under 200USD and the seller seems reliable - that's a reasonable deal these days. There's a posting now on eBay for a pair at 330 USD. Not a bad offer and I bought from the seller last year a single tube at quite a low price. It was delivered fast, safe and as advertised but with glue pieces moving in the base (not advertised this). Not my best "feeling" tube, but sounds just like a 5998 should.

Otherwise find some good 6080s or 6AS7Gs. Some say the TS 6AS7G sounds even better in their system than the TS 5998.

The best, best way is to know people in the hobby. You can always trust a friend to sell you a used but great sounding/performing 5998 over a stranger selling you an "NOS" 5998. But this takes time in the hobby.


----------



## GreenNeedle

You can get lucky sometimes.  £40 buy it now for 2.  Might not have worked but they both do and sound awesome


----------



## L0rdGwyn (Jul 30, 2021)

Every once in a while, you can fix a short in a tube.  If the heater lights but it doesn't conduct, you can check for continuity between pins with a DMM (or if you have a capable tube tester).  If you figure out which electrodes are shorted, you might be able to spot the short visually.  Since the tube is already nonfunctional, you can whack it a few times in the direction you think might break the short, shifting the internals slightly, and check the short again with a DMM.  Have to do this delicately - enough force to shift the internals, but not enough to shatter the tube!  This doesn't always work, but it has fixed two valuable tubes in the past for me: a Sylvania 45 DHT and a Tung-Sol 5998.


----------



## HTSkywalker

Mightygrey said:


> Last one I'll ever need...unless my cats break it.


Well Chatham is as good 👍


----------



## HTSkywalker

Dude707Can said:


> Where is good place to get the TS at a reasonable price?


While it's mostly off and on on eBay, I recommend getting one from a regular trusted store while they have it. The eBay thing unless you know the seller is kind of a gamble.
my 2 Cents


----------



## HTSkywalker

GreenNeedle said:


> You can get lucky sometimes.  £40 buy it now for 2.  Might not have worked but they both do and sound awesome


That's a catch, will give 41 for a single 😁😁


----------



## Tom-s

The greatest Bottlehead gateway drug is going on sale this weekend!
Starting Sunday 15th.
Have a look at the Bottlehead forum for more details. 
Can't wait for my next builds!
Greeted by the top plates!



Then comes the parts list for your Crack.




And then the kit with all the small parts and Bottlehead's transformer box.



Can I build one?  -> Yes! 

Here's a great video on Bottlehead kits.


----------



## HTSkywalker

Tom-s said:


> The greatest Bottlehead gateway drug is going on sale this weekend!
> Starting Sunday 15th.
> Have a look at the Bottlehead forum for more details.
> Can't wait for my next builds!
> ...


Keep us posted


----------



## DeweyCH

I think my favorite tube combo right now is a Tung-Sol 5998 + Sylvania VT-99 in an adapter. Really detailed, bass hits just right, and for whatever reason the VT-99 looks really cool with that little hat on it.


----------



## zizzyhead

DeweyCH said:


> I think my favorite tube combo right now is a Tung-Sol 5998 + Sylvania VT-99 in an adapter. Really detailed, bass hits just right, and for whatever reason the VT-99 looks really cool with that little hat on it.


Very cool! Does the VT-99 require any circuitry mods to be done?


----------



## DeweyCH

zizzyhead said:


> Very cool! Does the VT-99 require any circuitry mods to be done?


Nope, just an adapter. That said I have Speedball installed. I’ve read that you really should have that installed if you’re going to use any adapters, but I used my 6SN7 adapter before doing the upgrade and it was fine.

Actually it’s two adapters - 12AU7–>6SN7 and 6SN7–>VT-99/6F8G


----------



## jonathan c

DeweyCH said:


> Nope, just an adapter. That said I have Speedball installed. I’ve read that you really should have that installed if you’re going to use any adapters, but I used my 6SN7 adapter before doing the upgrade and it was fine.
> 
> Actually it’s two adapters - 12AU7–>6SN7 and 6SN7–>VT-99/6F8G


An infant HeadFier might say: “adadapters” ?


----------



## DenverW

"Adapterers"


----------



## DeweyCH

jonathan c said:


> An infant HeadFier might say: “adadapters” ?


You should see it when I run dual A2293s in the back and dual 6J5s up front. Looks exactly like a toddler got ahold of a bunch of tubes and slammed them into place.


----------



## cddc

Double-adaptering is *illegal* in the kingdom of tubes   

Here is what we should be looking for


----------



## zizzyhead (Aug 16, 2021)

Sweet, now where can I get one?? Or what is the proper terminology for me to use to find one?


----------



## cddc

I got this one from fleabay long time ago...just search "6F8G to 12AU7 adapter", I'm pretty sure there're lots of them.

Just make sure choose the 6.3V version.


----------



## jonathan c

cddc said:


> Double-adaptering is *illegal* in the kingdom of tubes


What about adapter rolling?…


----------



## zizzyhead

@cddc thanks!


----------



## cddc

jonathan c said:


> What about adapter rolling?…




If that happens, the subject is either mad or a tube vendor shilling tubes (more likely the later if the number of adapters is suspicious or using some tubes that are totally unrelated or unworthy to buy adapter for).

That said, having several adapters (for alternative tubes folks normally use for the amp) is totally acceptable.


----------



## cddc

zizzyhead said:


> @cddc thanks!



You are welcome


----------



## DeweyCH

cddc said:


> Double-adaptering is *illegal* in the kingdom of tubes
> 
> Here is what we should be looking for


I had @Deyan make me a 12AU7 --> Dual 6J5 adapter because I wanted to avoid adapters on adapters. With this one... meh.


----------



## cddc

DeweyCH said:


> I had @Deyan make me a 12AU7 --> Dual 6J5 adapter because I wanted to avoid adapters on adapters. With this one... meh.



I was just kidding on double-adpatering...LOL

Having Deyan build adapter is another way to get adapters.


----------



## jonathan c

cddc said:


> I was just kidding on double-adpatering...LOL
> 
> Having Deyan build adapter is another way to get adapters.


Is an adpater a rewired adapter?…


----------



## jonathan c

cddc said:


> I was just kidding on double-adpatering...LOL
> 
> Having Deyan build adapter is another way to get adapters.


And he does great work!


----------



## Galapac

What about double socket savers? Seen one person do it many times with pics.


----------



## cddc

Galapac said:


> What about double socket savers? Seen one person do it many times with pics.



I remember seeing the funny pic once...the guy is using double socket savers to lift up some ridiculously huge light bulb sized new production 6SN7 tube, otherwise the 2 big 6SN7s can not fit in his Elise/Euphoria I believe. 

Nothing against double adaptering, it works


----------



## DenverW

Trying out a new tube tomorrow.  Found an old welded plate Lorenz circle getter from a seller overseas.  The seller set it up for auction and no one recognized the differences in this tube vs the standard newer lorenz.   Doens't look like much ,but Potentially one of the best 12au7 tubes of all time.

Also going to try some 6cg7 tubes, as thats a variant I haven't rolled before and I have an adappterer.  (The 2nd P is silent).


----------



## GreenNeedle

DenverW said:


> Trying out a new tube tomorrow.  Found an old welded plate Lorenz circle getter from a seller overseas.  The seller set it up for auction and no one recognized the differences in this tube vs the standard newer lorenz.   Doens't look like much ,but Potentially one of the best 12au7 tubes of all time.
> 
> Also going to try some 6cg7 tubes, as thats a variant I haven't rolled before and I have an adappterer.  (The 2nd P is silent).


What did the font say?  ECC82?


----------



## DenverW

GreenNeedle said:


> What did the font say?  ECC82?



Yea, faded.


----------



## DenverW

As a follow up, this tube is an absolute winner.  Very, very musical.  Just...right sounding.  Bass is present, and overall very smooth.  There is an article by homestead called 'best of the best 12au7.'  I've hunted down a good amount of these super rare/expensive 12au7 that they tested.  Some, such as the amperex 45 degree welded plate or the oldest of Victor RCA are winners, while some I found a bit average in the crack.  The mullard 10m was an example of this; it just didn't hit my preferences.  

I've been hunting this lorenz tube for a long time, and finding only newer tubes.  It was a real steal to grab this in an auction for $10; it really paid off recognizing what it was.  This is in contention for my favorite tube at the moment.


----------



## dstarr3

I'm torn. I placed a preorder for a DarkVoice 336SE on Drop, and then discovered the Bottlehead Crack. Considering I'm looking for a tube amp to complement my HD6XX, suddenly the Crack seems like a better choice.

Thoughts on the two?


----------



## DenverW

dstarr3 said:


> I'm torn. I placed a preorder for a DarkVoice 336SE on Drop, and then discovered the Bottlehead Crack. Considering I'm looking for a tube amp to complement my HD6XX, suddenly the Crack seems like a better choice.
> 
> Thoughts on the two?



Ive had both, and besides sharing the ability to roll 6sn7 (the crack with speedball and an adapter) and 6080 variants, they’re pretty different.  Overall I much preferred the crack.  As an otl it has a tube warmth that the darkvoice did not have.  The darkvoice allowed me to run a wider variety of headphones with different Impedances, where the crack should be using high impedance headphones to sound best.  For the 6xx, I would disagree with anyone who thought it was better on the darkvoice.  Of course, you don’t have to build a darkvoice.  on the flip side, I would often have 6sn7 tubes require burn in to remove hum on the darkvoice, while they would play without a hitch on the crack.

Tldr: crack


----------



## dstarr3

I actually like the kit nature of it. I'm a woodworker, so I look forward to making the box for it out of zebrawood or some other exotic wood.

I also have an MP AKG Sextett that currently I can only drive with my AVR in the living room. Anybody have any experience driving Sextetts on the Crack?


----------



## skhan007

So we finally got our basement finished and now I have a proper dedicated spot for my BHC and RMI ADI-2 DAC. It's a perfect, quiet, place where I can put on my ZMF's and escape! Still really loving the GEC 6080 and RCA clear top combo!


----------



## ScornDefeat

skhan007 said:


> So we finally got our basement finished and now I have a proper dedicated spot for my BHC and RMI ADI-2 DAC. It's a perfect, quiet, place where I can put on my ZMF's and escape! Still really loving the GEC 6080 and RCA clear top combo!



I absolutely LOVE the look of your BH Crack! I have a "marble" topped desk in my office and would like to make a matching BH Crack; how did you achieve this finish???


----------



## L0rdGwyn

dstarr3 said:


> I'm torn. I placed a preorder for a DarkVoice 336SE on Drop, and then discovered the Bottlehead Crack. Considering I'm looking for a tube amp to complement my HD6XX, suddenly the Crack seems like a better choice.
> 
> Thoughts on the two?



I would also vote the Crack.  From a circuit design standpoint, the Crack is the better of the two, especially when you factor in the Speedball which adds an active load to both the input and output tube.  This reduces distortion, power supply rejection (i.e., noise), will increase the gain slightly as well.

The DarkVoice only has 30uF of output capacitance per channel, the Crack has 100uF.  That means that as you lower the impedance of the headphone used, the bass extension will roll off faster in the DarkVoice, so the Crack is better suited for lower impedance headphones, the output impedance of both amps will be roughly the same.  From a heat management standpoint, the DarkVoice is poorly designed - the resistors loading the output tube are mounted directly on the chassis which has pretty poor ventilation, so it gets HOT.  That means poor longevity for the parts inside, especially electrolytic capacitors.

Also factor in that building the Crack, if you choose to do so, is a great learning experience and might open the door to a very satisfying DIY audio hobby.  You can even mod the Crack quite easily to use different input tubes.

Also the stock pot on the DarkVoice I'm quite certain is made of sand, it is extremely scratchy.


----------



## dstarr3

DenverW said:


> Trying out a new tube tomorrow.  Found an old welded plate Lorenz circle getter from a seller overseas.  The seller set it up for auction and no one recognized the differences in this tube vs the standard newer lorenz.   Doens't look like much ,but Potentially one of the best 12au7 tubes of all time.
> 
> Also going to try some 6cg7 tubes, as thats a variant I haven't rolled before and I have an adappterer.  (The 2nd P is silent).



I'm still new to the world of tube shopping. How do I tell this tube apart from other Lorenz tubes I can see on eBay?


----------



## DeweyCH

dstarr3 said:


> I actually like the kit nature of it. I'm a woodworker, so I look forward to making the box for it out of zebrawood or some other exotic wood.
> 
> I also have an MP AKG Sextett that currently I can only drive with my AVR in the living room. Anybody have any experience driving Sextetts on the Crack?


I was running my Sextetts on my Crack tonight. They’re really fabulous together. I also have a DV that I upgraded significantly, which also gets along great with the Sextetts but which is on the shelf because the Crack outdoes it. I have the Speedball in mine.


----------



## skhan007

ScornDefeat said:


> I absolutely LOVE the look of your BH Crack! I have a "marble" topped desk in my office and would like to make a matching BH Crack; how did you achieve this finish???


Thanks- It’s White Carrera granite. I had it custom made.


----------



## wabibito

Any one know the difference between 12BH7 and 12BY7?


----------



## raindownthunda

wabibito said:


> Any one know the difference between 12BH7 and 12BY7?


Are you listening to these in your crack? I don't think these are drop-in compatible in the 12au7 socket and would require some mods. Not sure about the 12BH7 vs 12BY7, but I recently found out the 12BY7 was used in the the famous Harmon Kardon Citation II amp. The Brimar 6870 is another video pentode that is supposed to be fairly similar... @A2029 makes adapters for these family of tubes to work in his Blue Halo OTL amp.


----------



## wabibito

raindownthunda said:


> Are you listening to these in your crack? I don't think these are drop-in compatible in the 12au7 socket and would require some mods. Not sure about the 12BH7 vs 12BY7, but I recently found out the 12BY7 was used in the the famous Harmon Kardon Citation II amp. The Brimar 6870 is another video pentode that is supposed to be fairly similar... @A2029 makes adapters for these family of tubes to work in his Blue Halo OTL amp.


I have installed the board that can switch between the 12AU7 and the 12BH7.  I bought a 12HB7 and the seller threw in a 12BY7 also.  I wonder if it will work or not.


----------



## L0rdGwyn (Aug 19, 2021)

wabibito said:


> I have installed the board that can switch between the 12AU7 and the 12BH7.  I bought a 12HB7 and the seller threw in a 12BY7 also.  I wonder if it will work or not.



Well 12BY7 is a very different tube than a 12BH7 - 12BH7 is a dual triode, similar to a 12AU7, whereas a 12BY7 is a pentode, so not really going to work, unless you get a pair and then triode strap them, which would likely necessitate some changes to the bias point, which starts to get complicated.  Probably best to just stick to the 12BH7!


----------



## wabibito

L0rdGwyn said:


> Well 12BY7 is a very different tube than a 12BH7 - 12BH7 is a dual triode, similar to a 12AU7, whereas a 12BY7 is a pentode, so not really going to work, unless you get a pair and then triode strap them, which would likely necessitate some changes to the bias point, which starts to get complicated.  Probably best to just stick to the 12BH7!


Thank you much for the explanation. I will file this tube in the electronic etc drawer lolz.


----------



## HTSkywalker

DV advantages:
- Cheaper
- no assembly required
- handles lower impedance cans from Crack
- Could be used as a pre-amp
- 6AS7G/6080/5998 & 6SN7 out of the box

Crack advantages (W/Speedball):
- Warmer sound
- less humming
- Kit building
- better components
- Simpler design
- Customizable

While both amps are entry ones, the Crack have a slighter advantage but again it's one of those YMMV situation


----------



## ScornDefeat

skhan007 said:


> Thanks- It’s White Carrera granite. I had it custom made.



Gorgeous, and a great idea!


----------



## GreenNeedle

dstarr3 said:


> I actually like the kit nature of it. I'm a woodworker, so I look forward to making the box for it out of zebrawood or some other exotic wood.
> 
> I also have an MP AKG Sextett that currently I can only drive with my AVR in the living room. Anybody have any experience driving Sextetts on the Crack?



LP with the brown headband.  MP with the black headband.


----------



## DenverW

dstarr3 said:


> I'm still new to the world of tube shopping. How do I tell this tube apart from other Lorenz tubes I can see on eBay?



A good place to start is to get an idea of what welded vs non welded plate construction looks like.  Some of the best oldest 12au7 have welded plates, such as the amperex 45 degree slant getter.


----------



## skhan007 (Aug 23, 2021)

So, I'm in an interesting place with my very modest and simple set up:

BHC Speedball w/ clear top RCA pre amp and GEC 6080 power tube
RME- ADI2 DAC
ZMF Auteur cans

I'm completely happy listening to lossless files through this set up. The only thing I can think of is possibly trying some different tubes, but other than that, I feel strangely satisfied and pacified with the set up. I'll occasionally swap in my Chatham 6AS7G, but mostly loving the GEC 6080. This is odd, as my mindset (and the norm on the forum) is to be in a perpetual state of upgrading, purchasing, and wanting. Feels weird to be content.


----------



## ScornDefeat

Did anybody order a Crack during the sale 2 weeks ago? If so, anybody received a shipping notice yet?


----------



## Galapac

ScornDefeat said:


> Did anybody order a Crack during the sale 2 weeks ago? If so, anybody received a shipping notice yet?


Yes I did, mine shipped on 8/18 and getting it Wednesday but I was also one of the first to place an order as they stated first in/first out. Hope this helps.


----------



## ScornDefeat

Galapac said:


> Yes I did, mine shipped on 8/18 and getting it Wednesday but I was also one of the first to place an order as they stated first in/first out. Hope this helps.



Thanks! Sure does help, appreciate it! I also ordered it right when the sale started so I'm fairly surprised mine hasn't shipped yet. I'll give it another week before contacting them.

Thanks again!


----------



## Galapac

ScornDefeat said:


> Thanks! Sure does help, appreciate it! I also ordered it right when the sale started so I'm fairly surprised mine hasn't shipped yet. I'll give it another week before contacting them.
> 
> Thanks again!


Another note, I didnt get the speedball upgrade with mine as I already had one, if you got that , that may be the delay.


----------



## ScornDefeat

Galapac said:


> Another note, I didnt get the speedball upgrade with mine as I already had one, if you got that , that may be the delay.



I actually passed on the Speedball as I wanted to first try the Crack in its purest and rawest form (no pun intended lol).


----------



## dstarr3

How frequently do BHCs go on sale? This amp only came on my radar just the other day, so I missed this recent one, and I'm the kind of dude that tries to buy stuff only when it's on sale.


----------



## ScornDefeat

dstarr3 said:


> How frequently do BHCs go on sale? This amp only came on my radar just the other day, so I missed this recent one, and I'm the kind of dude that tries to buy stuff only when it's on sale.



The last sale I believe was in 2019, so not very often, unfortunately.


----------



## dstarr3

Bummer. Well, I guess it was only $60 off and not, like, hundreds off or anything.


----------



## raindownthunda

dstarr3 said:


> Bummer. Well, I guess it was only $60 off and not, like, hundreds off or anything.


If you’re planning to build a custom enclosure, I was able to save a few bucks ($45) by opting out of the wood panels. Not sure if they are still doing this, but you can email and ask.


----------



## dstarr3

Ahh, good shout. I'll have to write and see. Thanks!


----------



## jonathan c

skhan007 said:


> So, I'm in an interesting place with my very modest and simple set up:
> 
> BHC Speedball w/ clear top RCA pre amp and GEC 6080 power tube
> RME- ADI2 DAC
> ...


To paraphrase WC Fields: “if you feel the urge to ‘upgrade’, lie down until the feeling goes away”…😜…


----------



## wabibito

ScornDefeat said:


> Thanks! Sure does help, appreciate it! I also ordered it right when the sale started so I'm fairly surprised mine hasn't shipped yet. I'll give it another week before contacting them.
> 
> Thanks again!


You might one to email them. I ordered two to build for friends. One with speedball and one without. Last week I got an email asking if I preferred two boxes or one. I replied saying 1 is fine and I got both today.


----------



## ScornDefeat

wabibito said:


> You might one to email them. I ordered two to build for friends. One with speedball and one without. Last week I got an email asking if I preferred two boxes or one. I replied saying 1 is fine and I got both today.



Thanks for the insights! I have taken your advice and checked-in with them, it does seem odd that I have heard nothing so far. 

Thanks again.


----------



## DenverW

Has anyone tried 6cg7 tubes?  My first attempt was a bust; no sound.  It’s either a bum tube, bum adapter, or I’m missing something.  If anyone has tried this with an adapter with success, would you mind linking me?


----------



## HTSkywalker

skhan007 said:


> So, I'm in an interesting place with my very modest and simple set up:
> 
> BHC Speedball w/ clear top RCA pre amp and GEC 6080 power tube
> RME- ADI2 DAC
> ...


The Chatham should kick ass in your setup 👌👌


----------



## HTSkywalker

jonathan c said:


> To paraphrase WC Fields: “if you feel the urge to ‘upgrade’, lie down until the feeling goes away”…😜…


It usually only goes away once you press "place order", "lie"ing about it won't help 😁😁😁😁


----------



## tintinsnowydog

DenverW said:


> Has anyone tried 6cg7 tubes?  My first attempt was a bust; no sound.  It’s either a bum tube, bum adapter, or I’m missing something.  If anyone has tried this with an adapter with success, would you mind linking me?


6CG7 is electrically equivalent to the 6SN7 in a 9 pin envelope, so should be fine as long as the adapter is the correct pinout. I used an ECC88 --> 12AU7 adapter as they have the same pinout 6CG7 and ECC88.


----------



## DenverW

tintinsnowydog said:


> 6CG7 is electrically equivalent to the 6SN7 in a 9 pin envelope, so should be fine as long as the adapter is the correct pinout. I used an ECC88 --> 12AU7 adapter as they have the same pinout 6CG7 and ECC88.



Thanks, I tried some different tubes and determined that the adapter I have is faulty, so I'll look for an ecc88 adapter .  Appreciate it!


----------



## muscleking

so just jumping on this thread since i knew bottlehead for a long time but never used one. need something to amp my new old zmf eikon headphones, maybe it's driven well but i just wonder what tube can do. i used it for a few hours with hugo 1. not bad but i think the bass can be better. put in my 64 audio u12 and it sounded better than the eikon honestly, more bass and more low detail. other sectors are comparable.

the bottlehead what makes the components worth almost 500 USD? is there a chinese copy that is identical? i have a beyerdynamic A1 and i know chinese copied this thing 1 to 1 for like a fraction of the cost. i saw someone selling a bottlehead mainline on audiomart and it went fast less than a day of listing. probably that's the one to go. i wonder it's gonna be better than my audiogd reference 10.32. i haven't take that out after moving yet it is too big and heavy to set up and i have yet to put in the furutech wall duplex set with good power cable. also the IFI iusb 3.0 set i got. i was hoping the eikon can surprise me it's good don't get me wrong but if i am to keep one headphone i would keep the u12 and hugo 1, magic combination. maybe i found my end game but hey this hobby never stops lol. i was gonna quit buying then came across deal for hd820 then the eikon. sold my lcd-xc and i do miss the bass on the audeze a lot. i'll give the eikon some more time. i know each headphone my brain need to adjust a bit. too many gears to mix and match to test lol. i have a schiit loki mini that i got months ago and never took it out of the box : ( the ower told me some settings to go with the beyer A1 and T1 first gen high serial i got from him as well.


----------



## Galapac

There are so many thoughts going on in that paragraph I wouldn't know how to respond.


----------



## jonathan c (Sep 9, 2021)

Galapac said:


> There are so many thoughts going on in that paragraph I wouldn't know how to respond.


I agree. “Too many gears to mix and match” in that outpouring…I have owned a BHC…but I am not certain that I can be of help…


----------



## DenverW

muscleking said:


> so just jumping on this thread since i knew bottlehead for a long time but never used one. need something to amp my new old zmf eikon headphones, maybe it's driven well but i just wonder what tube can do. i used it for a few hours with hugo 1. not bad but i think the bass can be better. put in my 64 audio u12 and it sounded better than the eikon honestly, more bass and more low detail. other sectors are comparable.
> 
> the bottlehead what makes the components worth almost 500 USD? is there a chinese copy that is identical? i have a beyerdynamic A1 and i know chinese copied this thing 1 to 1 for like a fraction of the cost. i saw someone selling a bottlehead mainline on audiomart and it went fast less than a day of listing. probably that's the one to go. i wonder it's gonna be better than my audiogd reference 10.32. i haven't take that out after moving yet it is too big and heavy to set up and i have yet to put in the furutech wall duplex set with good power cable. also the IFI iusb 3.0 set i got. i was hoping the eikon can surprise me it's good don't get me wrong but if i am to keep one headphone i would keep the u12 and hugo 1, magic combination. maybe i found my end game but hey this hobby never stops lol. i was gonna quit buying then came across deal for hd820 then the eikon. sold my lcd-xc and i do miss the bass on the audeze a lot. i'll give the eikon some more time. i know each headphone my brain need to adjust a bit. too many gears to mix and match to test lol. i have a schiit loki mini that i got months ago and never took it out of the box : ( the ower told me some settings to go with the beyer A1 and T1 first gen high serial i got from him as well.



1.  Eikon and other high impedance headphones pair very, very well with the crack, as it is OTL.
2.  Your u12 would not, it is much better on solid state amps.
3.  There is no Chinese equivalent, and if there were, I wouldn’t direct you to a site ripping off Bottlehead.
4.  Part of the magic of the amp is building it yourself, and upgrading it.
5.  That was a tough stream of consciousness post to decode.


----------



## DenverW

Picked up this adapter to see if my previous one was faulty and it ended up working perfectly.

https://www.ebay.com/itm/201083377532

Testing out 3 different 6cg7 tubes, an amperex, sylvania, and tung sol.  So far enjoyable tubes, but perhaps just a step behind my best 12au7.  Great value, though, as all three tubes cost a total of about $35.  These tubes remind me of the e80cc phillips in their shape and sound.


----------



## Galapac

DenverW said:


> Picked up this adapter to see if my previous one was faulty and it ended up working perfectly.
> 
> https://www.ebay.com/itm/201083377532
> 
> Testing out 3 different 6cg7 tubes, an amperex, sylvania, and tung sol.  So far enjoyable tubes, but perhaps just a step behind my best 12au7.  Great value, though, as all three tubes cost a total of about $35.  These tubes remind me of the e80cc phillips in their shape and sound.


This is a really good one to roll in 6SN7s into the BHC, you probably have one…https://www.ebay.com/itm/265086338924
It was a life saver for me in $$$ as I moved on from the DV 336se and they use the 6AS7/6080 6SN7 combination.


----------



## DenverW

Ive tried stock, 12bh7, E80cc, 6j5, 6f8g, 6sn7, cv6, vt-232 and some others I can’t remember.  Now the 6cg7.  Id say my favorite aside from stock 12au7 is the frankentube cv6, both for the sound and how cheap you can find the different variants.


----------



## Galapac

DenverW said:


> Ive tried stock, 12bh7, E80cc, 6j5, 6f8g, 6sn7, cv6, vt-232 and some others I can’t remember.  Now the 6cg7.  Id say my favorite aside from stock 12au7 is the frankentube cv6, both for the sound and how cheap you can find the different variants.


Thanks for the lead, I’ll give the CV6 a try, with an adapter for my BHC.


----------



## DenverW

Galapac said:


> Thanks for the lead, I’ll give the CV6 a try, with an adapter for my BHC.


So the adapter works for 7193 tubes, which are also good.  Cv6 and e1148 (hytron) tubes connect differently at the top than the 7193 ones.  7193 go to the closer point, where the cv6 goes across the tube to he farther point.


----------



## wabibito

Where could I get the adapter for the cv6? Thanks.


----------



## DenverW

I believe this is the one I have:  https://www.ebay.com/itm/191552830664?hash=item2c99703cc8:g:LiAAAOSwHnFVtZ7p


----------



## muscleking

DenverW said:


> 1.  Eikon and other high impedance headphones pair very, very well with the crack, as it is OTL.
> 2.  Your u12 would not, it is much better on solid state amps.
> 3.  There is no Chinese equivalent, and if there were, I wouldn’t direct you to a site ripping off Bottlehead.
> 4.  Part of the magic of the amp is building it yourself, and upgrading it.
> 5.  That was a tough stream of consciousness post to decode.



thanks man. yeah I have tendency to hoard gears and can't decide which one is better than the other. i spent some more time with hugo and eikon and they pair quite well. still the U12 has some strong bass. it is definitely a keeper. so small and light and powerful.

i'll keep an eye for the crack for sale. saves me time building it and likely cheaper too than buying new. 

i had a little dot iii and rolled tube for quite a while and it didn't sound too good. so a bit skeptical on tubes amps. i think i ran the SMSL M8 as dac with it and later the SMSL amp that came with it and couldn't tell too much sound differences. i would love to attend some meet ups but too bad i am in small city in Canada. maybe down the road go work in US for a bit and can listen to more gears.

so the parts alone is worth it for the crack? it looks very simple. so if i to build one, you recommend using silver solder?


----------



## DenverW

muscleking said:


> thanks man. yeah I have tendency to hoard gears and can't decide which one is better than the other. i spent some more time with hugo and eikon and they pair quite well. still the U12 has some strong bass. it is definitely a keeper. so small and light and powerful.
> 
> i'll keep an eye for the crack for sale. saves me time building it and likely cheaper too than buying new.
> 
> ...



Non otl tube amps tend to sound more solid state like to me.  The crack has a tubey Goodness that made me fall in love with the sound.  I would advise against buying used if possible.  The experience gained building the amp gives knowledge and confidence for upgrading the amp and for other projects.  If something ever happens to the amp you’ll have the knowledge to troubleshoot and take care of it,  there is also a certain pride from listening to something you built.  It doesn’t take that long.


----------



## Galapac

Plus you will never get a BHC cheaper than the kit…once built there is the added premium for the builder’s time and materials and any mods added. Like @DenverW said, better to build yours from scratch with the knowledge gained and pride that you built something that sounds really cool, even without any mods IMO.


----------



## muscleking

DenverW said:


> Non otl tube amps tend to sound more solid state like to me.  The crack has a tubey Goodness that made me fall in love with the sound.  I would advise against buying used if possible.  The experience gained building the amp gives knowledge and confidence for upgrading the amp and for other projects.  If something ever happens to the amp you’ll have the knowledge to troubleshoot and take care of it,  there is also a certain pride from listening to something you built.  It doesn’t take that long.





Galapac said:


> Plus you will never get a BHC cheaper than the kit…once built there is the added premium for the builder’s time and materials and any mods added. Like @DenverW said, better to build yours from scratch with the knowledge gained and pride that you built something that sounds really cool, even without any mods IMO.



what is the most expensive component in here that make it cost over 400USD? i am thinking the wooden enclosure must took a lot of time to make. the other stuff, capacitors, resisters and small transformer can't be that hard to source?

the bottlehead mainline was listed for 1300 cad and sold in minutes. now i know how much that one is worth.


----------



## Galapac

Most expensive component is the transformer. If you bought the BHC last month it was $300 but regularly sells for $350, not over $400, unless you buy the speedball kit along with it, but not necessary.


----------



## DenverW

muscleking said:


> what is the most expensive component in here that make it cost over 400USD? i am thinking the wooden enclosure must took a lot of time to make. the other stuff, capacitors, resisters and small transformer can't be that hard to source?
> 
> the bottlehead mainline was listed for 1300 cad and sold in minutes. now i know how much that one is worth.



You could ask that question about pretty much every amp, dac, or headphone on the market.  Sometimes things are greater than the sum of their parts.


----------



## Wes S (Sep 14, 2021)

DenverW said:


> Trying out a new tube tomorrow.  Found an old welded plate Lorenz circle getter from a seller overseas.  The seller set it up for auction and no one recognized the differences in this tube vs the standard newer lorenz.   Doens't look like much ,but Potentially one of the best 12au7 tubes of all time.
> 
> Also going to try some 6cg7 tubes, as thats a variant I haven't rolled before and I have an adappterer.  (The 2nd P is silent).


Nice tube!  I recently discovered the Tungsram welded plates myself, and I am loving them.  I have never seen a Lorenz rebrand though, that's a nice find.  If you like the grey welded plate version, I highly suggest keeping an eye out for the earlier black welded plate version as well.


----------



## Galapac (Sep 25, 2021)

Trying out the E-1148 Franken tubes today…timing couldn’t be better with Halloween 🎃 right around the corner.
Fall is my favorite time of year when the air is cooler, crisper…the leaves are falling…and the tube amp keeps me warm while I enjoy my music.
Pure bliss!


----------



## DenverW

Galapac said:


> Trying out the E-1148 Franken tubes today…timing couldn’t be better with Halloween 🎃 right around the corner.
> Fall is my favorite time of year when the air is cooler, crisper…the leaves are falling…and the tube amp keeps me warm while I enjoy my music.
> Pure bliss!


Looking forward to your thoughts!  I liked that variant.


----------



## HTSkywalker

Galapac said:


> Trying out the E-1148 Franken tubes today…timing couldn’t be better with Halloween 🎃 right around the corner.
> Fall is my favorite time of year when the air is cooler, crisper…the leaves are falling…and the tube amp keeps me warm while I enjoy my music.
> Pure bliss!


You definitely sound happy with this combination 😍😍


----------



## Astral Abyss

Galapac said:


> Trying out the E-1148 Franken tubes today…timing couldn’t be better with Halloween 🎃 right around the corner.
> Fall is my favorite time of year when the air is cooler, crisper…the leaves are falling…and the tube amp keeps me warm while I enjoy my music.
> Pure bliss!


This is pure madness!


----------



## jonathan c

Astral Abyss said:


> This is *PURE *madness!


…not reconstituted…the real thing…like music…


----------



## Dawgfish

I'm new to the Bottlehead club and I'm really digging the Crack.  Currently I'm running a RCA 6AS7 for power tube and an RCA Clear Top 12AU7 for the input tube.  The only other power tube I have for it is a Raytheon 6080 which sounds quite good also.

I rolled a bunch of 12AU7s in this yesterday including Telefunken, Mullard, Amperex, EI, CBS-Hytron 5814, RCA Triple Mica BP 5814, Sylvania BP, and a lot of others.  To my surprise I liked the RCA Clear Top the best.

I have to caveat that I'm running not only the HD600 family of cans but also Beyerdynamic DT1990s and Amiron Homes on the Crack also.  On the DT1990s and Amiron Homes most of the tubes were a little too thick in the lows so the two best 12AU7 types to counter this were the Telefunken Smooth Plate and the RCA Clear Top.  If I were running just the HD600 family of cans I would lean towards either the CBS-Hytron 5814, Amperex 12AU7, or Mullard 12AU7.

As good as the Crack sounds with the HD600 and 6XX, I must say I'm enjoying it with the DT1990s more.  Granted I eq'd the nasty mid-treble spike the 1990 has and I'm also running Dekoni Elite Hybrid pads on it.  The 1990 paired with the Crack is fantastic!  The tube sweetness does wonders for the 1990s presentation (especially in addition to eq).  In this configuration it's smooth and warmly-tilted while retaining the 1990s amazing detail and dynamics.  The soundstage is very wide and deep also with fantastic imaging.  To my ears this combo does everything right with every type of music I've listened to on it while being highly listenable.


----------



## DenverW

Methinks you like treble....errr I mean clarity !  I do too, but preferred the hd600 for its overall tonal balance and the amiron home for games and movies for its nice soundstage.


----------



## Dawgfish

I'm definitely not a treble head by any imagination.  I've eq'd the treble substantially to levels similar to the Amiron and HD600, and probably closer to the HD6XX.  I can't take the 1990 treble in stock form.  Way to bright for me.  Interestingly enough though when you eq it to tame the highs, add the hybrid pads which also tames the highs while adding a little bass, and then add in OTL tube goodness it becomes magical.  Its dynamic and powerful while very pleasant to listen to. I'm pleasantly shocked with the findings.


----------



## Bonddam

Sold my Crack and now am fixing it as USPS demolished it. If you ever saw Ace Ventura where Jim is playing delivery guy and kicks around the box. Well USPS must play with swords because they did this




Then this happened.


----------



## Galapac

What? Those components/caps look like they were soaked in acid!
So I assume you sold it and it was returned?
Did you have insurance?

Insurance is a must have these days with the delivery services. The only one I am remotely trusting these days is UPS and I still opt for the insurance because of the lack of workers and logistical nightmares.

I feel for you, what a shame!


----------



## Dawgfish

Bonddam said:


> Sold my Crack and now am fixing it as USPS demolished it. If you ever saw Ace Ventura where Jim is playing delivery guy and kicks around the box. Well USPS must play with swords because they did this
> 
> Then this happened.


Oh wow!  So sorry to hear that!


----------



## Bonddam (Oct 21, 2021)

Everything back to normal took 10 minutes to fix and sounds perfect. Keep it for HD6xx makes them have a much better bass region. 

Maybe I'll actually paint it. Had to replace one wire and solder the choke back to the cap below it and good can glue with activator did the trick.


----------



## Mightygrey (Oct 31, 2021)

After five or so years of listening to my Crack but having to put up with the limited range of the stock volume pot, I finally got around to installing a new one. Following the advice of many people both here and on the Bottlehead forums, I opted for an Alps Blue Velvet. After a bit of tinkering, I got around to turning it back on, and to my disappointment, it wasn't working properly! There was no sound in the right channel, and the left channel didn't respond to changes in twisting the pot. I figured that I'd either wired it incorrectly or accidentally bumped something elsewhere while I was at it. I checked it a million times, and decided to reinstall the old pot as I thought that the Alps one I bought might have been DOA. Looking at the old pot, I realised that I hadn't linked the top/bottom ground lugs on the RHS with a piece of connecting wire. After soldering them together, it worked perfectly!

It doesn't sound any different, but the Alps Blue Velvet is a huge quality-of-life upgrade. I no longer have to reduce the source gain level upstream to get proper channel matching and usable volume range. Highly recommended.


----------



## sonic2911

Hi guys, anyone know where can I buy tube in local? I'm in Houston, TX
Thanks


----------



## jonathan c

sonic2911 said:


> Hi guys, anyone know where can I buy tube in local? I'm in Houston, TX
> Thanks


Try ‘Tubes Unlimited’. Telephone: 713-471-5408; Website: ‘www.nosvacuumtubes.net’; Joshua is the proprietor - a good fellow and I have ordered frequently with no problems. Tubes Unlimited is in Houston, TX.


----------



## sonic2911

thank you a lot


----------



## hikaru12

Hey guys I thought I saw this posted around here but I haven’t been able to find the original post - I have a 12AU7 to 6SN7 adapter in my Crack from TubeMonger and it works great but it doesn’t look that great considering it’s a stark white ceramic color. I know it’s probably trivial but someone mentioned someone on the forums makes custom metal 12AU to 6SN7 adapters. Does anyone happen to know who that is or if not where I can get some? Can post a picture to explain if needed.


----------



## raindownthunda

hikaru12 said:


> Hey guys I thought I saw this posted around here but I haven’t been able to find the original post - I have a 12AU7 to 6SN7 adapter in my Crack from TubeMonger and it works great but it doesn’t look that great considering it’s a stark white ceramic color. I know it’s probably trivial but someone mentioned someone on the forums makes custom metal 12AU to 6SN7 adapters. Does anyone happen to know who that is or if not where I can get some? Can post a picture to explain if needed.


@Deyan is the resident adapter maestro. Superior builds at fair prices.


----------



## VanHai (Nov 11, 2021)

Error.


----------



## Bonddam

My fellow Crack heads I was lead to believe the driver tube does not change the sound on this amp. Possibly misunderstood as I thought they are used in the gain and not a buffer stage.


----------



## Dawgfish

My experience is both tubes make a difference in sound.


----------



## cddc

Bonddam said:


> My fellow Crack heads I was lead to believe the driver tube does not change the sound on this amp. Possibly misunderstood as I thought they are used in the gain and not a buffer stage.



My experience is that on Crack driver tube makes about 40% and power tube makes around 60% impact in terms of tube rolling.

You need a good power tube to set up the backbone of the sound, then use the driver tube to fine tune the sound to your own liking.


----------



## cddc

hikaru12 said:


> Hey guys I thought I saw this posted around here but I haven’t been able to find the original post - I have a 12AU7 to 6SN7 adapter in my Crack from TubeMonger and it works great but it doesn’t look that great considering it’s a stark white ceramic color. I know it’s probably trivial but someone mentioned someone on the forums makes custom metal 12AU to 6SN7 adapters. Does anyone happen to know who that is or if not where I can get some? Can post a picture to explain if needed.



Deyan makes excellent plastic adapters, but he doesn't seem to make metal adapters. If you are looking for metal like adapters, I am not sure if Woo makes 12AU7 to 6SN7 adapters, but I find their adapters look great with white ceramic base and a metal ring, their prices are ridiculously expensive though...lol


----------



## Bonddam

Show my Shugaung cv181-z with some Sylvania 6080 which sounds amazing with my ZMF Verite Closed sporting some fake Audeze LCD pads I got off eBay and no more Zmf house sound. It's a bonus when I actually don't think about listening to the Abyss 1266.


----------



## hikaru12

cddc said:


> Deyan makes excellent plastic adapters, but he doesn't seem to make metal adapters. If you are looking for metal like adapters, I am not sure if Woo makes 12AU7 to 6SN7 adapters, but I find their adapters look great with white ceramic base and a metal ring, their prices are ridiculously expensive though...lol


Ah looking for all black metal adapters. Ceramic is nice for noise but I’ve never seen them in full black.


----------



## Bonddam

hikaru12 said:


> Ah looking for all black metal adapters. Ceramic is nice for noise but I’ve never seen them in full black.


My tubes base is white so it works for that tube.


----------



## Bonddam

Glad USPS forced my hand to refund the seller. Now I can enjoy it.


----------



## Bonddam

Hey I just got shocked by the 6sn7 adapter my finger slipped an touched the metal below the base didn't hurt but gave my finger wake up. lol


----------



## VanHai (Nov 13, 2021)

Bonddam said:


> Hey I just got shocked by the 6sn7 adapter my finger slipped an touched the metal below the base didn't hurt but gave my finger wake up. lol


I am glad that you are ok, I think i have the same adapter bought from Garage 1217 on Ebay. The first thing that i noticed the metal that exposed at the bottom, it is hazardous to your health so i hacked it by cutting a part of plastic tube for medicine to cover it. It fits perfectly and prevent you from touching the base.


----------



## Bonddam

VanHai said:


> I am glad that you are ok, I think i have the same adapter bought from Garage 1217 on Ebay. The first thing that i noticed the metal that exposed at the bottom, it is hazardous to your health so i hacked it by cutting a part of plastic tube for medicine to cover it. It fits perfectly and prevent you from touching the base.


I'm doing that today. It's a nice adapter but I got kids. Thanks for tip. The clear orange adds flare.


----------



## GreenNeedle (Nov 16, 2021)

The black rubber caps that fit on the end of a brush handle work really well on these adaptors.  Just cut the bottom off and they are just about a perfect fit and positioned right they will just overlap the base of the tube a little..

These are the sort of things I mean.  Can't remember the diameter I bought.  Long time ago.  Measure the adaptor.
https://www.ebay.co.uk/itm/23367797...xx7XFzXiHxpgsapI0%3D|ampid:PL_CLK|clp:2047675


----------



## Bonddam

GreenNeedle said:


> The black rubber caps that fit on the end of a brush handle work really well on these adaptors.  Just cut the bottom off and they are just about a perfect fit.




Only time I use brush is tall grass toothbrush and hairbrush. Not sure what describes brush in the UK. Same words different meanings between us.


----------



## GreenNeedle (Nov 16, 2021)

Bonddam said:


> Only time I use brush is tall grass toothbrush and hairbrush. Not sure what describes brush in the UK. Same words different meanings between us.


This sort of thing.  Metal handled sweeping brushes often have one on the end of the handle:


----------



## Bonddam

GreenNeedle said:


> This sort of thing.  Metal handled sweeping brushes often have one on the end of the handle:


We call it end caps. So in UK it's brush?


----------



## buencamino

hey, fairly new to OTL tube amps and assembled a crack a few months ago. Actually the experience with the HD800S I have is kind of underwhelming. Sounded pretty normal to me, despite all the hype the crack gets with senns cans. Was just wondering maybe I should change the stock tubes? I have no experience with tube rolling, but if it could improve the sound a bit (especially the soundstage, I mean the crack just took away all the soundstage my HD800S had..). Any advice from experienced users would be nice. Thanks in advance. Oh I use a Aune X8 dac magic as my dac with burson vivid op amps.


----------



## Bonddam

buencamino said:


> hey, fairly new to OTL tube amps and assembled a crack a few months ago. Actually the experience with the HD800S I have is kind of underwhelming. Sounded pretty normal to me, despite all the hype the crack gets with senns cans. Was just wondering maybe I should change the stock tubes? I have no experience with tube rolling, but if it could improve the sound a bit (especially the soundstage, I mean the crack just took away all the soundstage my HD800S had..). Any advice from experienced users would be nice. Thanks in advance. Oh I use a Aune X8 dac magic as my dac with burson vivid op amps.


Yes get RCA 6sa7g to start with also get the amp modes more here's inside of mine. I bought this from a member. It's awesome with my Verite open and closed. My HD6XX is way better on this amp them any solid state I tired. For $690 buck was worth the chance on it.


----------



## buencamino

Not changing tubes?


----------



## maxpudding

buencamino said:


> Not changing tubes?



Yeah you could do that and roll different tubes.

With adapters (make sure they are the 6.3V type) in the driver slot, you could try the 6SN7, or the 6J5s (you'll need two of these because each 6J5 is 1/2 of the 6SN7). 

I'd only recommend changing the inner stock parts if you are confident enough to do the mods, or probably you could send your stock crack to someone who could do the mods for you.


----------



## JamieMcC (Nov 17, 2021)

buencamino said:


> hey, fairly new to OTL tube amps and assembled a crack a few months ago. Actually the experience with the HD800S I have is kind of underwhelming. Sounded pretty normal to me, despite all the hype the crack gets with senns cans. Was just wondering maybe I should change the stock tubes? I have no experience with tube rolling, but if it could improve the sound a bit (especially the soundstage, I mean the crack just took away all the soundstage my HD800S had..). Any advice from experienced users would be nice. Thanks in advance. Oh I use a Aune X8 dac magic as my dac with burson vivid op amps.



Congratulations on building your Crack. I can understand where you're coming from with your hd800 I use them as well and have built a number of Cracks in the past.  The Crack is a fun amp it's reputation is essentially built off of its pairing with the Senn 600 & 650.

it's possible with premium tubes and some straight forward modifications to make noticeable gains in its sonics with the hd800 that's probably the route that the majority of Crack users take no matter what headphones they use with it.

Ultimately though the thing to bear in mind is even when spending on expensive tubes and upgraded components and modifications your hd800 performance is still going to be restricted by the Cracks technical ability.

What you will end up with taking that path will sound very nice and you will end up with a unique to you amp.

However its of importance to understand that while that is a enjoyable journey to undertake with the Crack it would be more financially economical to just go with one a more capable amp than spend time and money upgrading a Crack.


----------



## Bonddam

I put in one of my 7N7 tv tubes with two adapters. I have the 6sn7 adapter then Woo's 7N7 adapter. The tube is sitting almost as high as the RCA 6AS7G very good sound. I'm waiting on more RCA 6AS7G tubes of different decades and hopefully a replacement to my current one which has noise heard in cathode tube tv's so not a hum more midrange pitch only coming out of the right channel.


----------



## Bonddam

Here's the crack two adapters and 7n7 Westinghouse.


----------



## DenverW

buencamino said:


> hey, fairly new to OTL tube amps and assembled a crack a few months ago. Actually the experience with the HD800S I have is kind of underwhelming. Sounded pretty normal to me, despite all the hype the crack gets with senns cans. Was just wondering maybe I should change the stock tubes? I have no experience with tube rolling, but if it could improve the sound a bit (especially the soundstage, I mean the crack just took away all the soundstage my HD800S had..). Any advice from experienced users would be nice. Thanks in advance. Oh I use a Aune X8 dac magic as my dac with burson vivid op amps.


What are the stock tubes you have now?


----------



## ColdsnapBry

Is there a good resource on Crack + Speedball upgrades a first time builder can do while making the thing? I want to do my first build, but also have a bit of extra money where I can do the upgrades during the build.


----------



## DenverW

ColdsnapBry said:


> Is there a good resource on Crack + Speedball upgrades a first time builder can do while making the thing? I want to do my first build, but also have a bit of extra money where I can do the upgrades during the build.


Bottlehead recommends not doing upgrades during the initial build and I completely agree.  It just gets harder to diagnose any issues.  

Down the road there is a speedball upgrade, switching to film caps, adding a choke, and switching to Cree diodes.


----------



## cddc

DenverW said:


> Bottlehead recommends not doing upgrades during the initial build and I completely agree.  It just gets harder to diagnose any issues.
> 
> Down the road there is a speedball upgrade, switching to film caps, adding a choke, and switching to Cree diodes.



I agree, from my personal experience. 

Do the basic Crack build first, not even with the Speedball upgrade, so that there will be less trouble for beginners. Otherwise, too much frustration could lead to give-up.

Once the basic Crack is successfully done, you can then add SB, and mods later.


----------



## cddc

ColdsnapBry said:


> Is there a good resource on Crack + Speedball upgrades a first time builder can do while making the thing? I want to do my first build, but also have a bit of extra money where I can do the upgrades during the build.



The Bottlehead forum is a good resource...though I haven't been there long time (here Head-Fi as well).


----------



## cddc

VanHai said:


> I am glad that you are ok, I think i have the same adapter bought from Garage 1217 on Ebay. The first thing that i noticed the metal that exposed at the bottom, it is hazardous to your health so i hacked it by cutting a part of plastic tube for medicine to cover it. It fits perfectly and prevent you from touching the base.





I have said many times here on the Crack thread - don't buy these Garage 1217 adapters, they are half done products. The exposed metal contacts on these Garage 1217 adapters pose huge hazards to safety, they could lead to shorts, shocks, or even death. Keep your kids away from these adapters!


----------



## DenverW

cddc said:


> I have said many times here on the Crack thread - don't buy these Garage 1217 adapters, they are half done products. The exposed metal contacts on these Garage 1217 adapters pose huge hazards to safety, they could lead to shorts, shocks, or even death. Keep your kids away from these adapters!


Agreed, the first crack I ever owned was purchased instead of built by me, and the input socket was slightly recessed.  The garage adapter shorted the amp, while the eBay adapter from xulingmrs worked fine.


----------



## cddc

Yeah, your case is the second case of Garage 1217 adapter shorting Crack chassis that I've seen here. Some Crack builders like to keep their 12AU7 socket low-profile, so they choose to mount it from the bottom of the chassis instead of to the top. Then, there won't be enough clearance for these exposed solder joints at the bottom of these Garage 1217 adapters, they will touch the metal chassis/screws and cause shorts.

Adding a plastic/rubber cylinder will protect against the exposed metal legs on top of the Garage 1217 adapters, but still the exposed solder joints at the bottom pose another threat to safety.

All in all, these Garage 1217 adapters lack of basic safety considerations (tubes are high voltage stuff in general, hence the exposed metal contacts pose huge threats), they are half-done products and should be avoided IMO.


----------



## Galapac (Nov 17, 2021)

Yep…either of these are better and insulated.
You want 6.3 volt version when buying these for standard BHC.

https://www.ebay.com/itm/203513997654?hash=item2f62612956:g:olsAAOSw5VFWLiss

https://www.ebay.com/itm/294212319817?hash=item44806bba49:g:G14AAOSwXuRe5Ey3

Deyan also can make you one and is a member here.


----------



## CaptainFantastic

Galapac said:


> Yep…either of these are better and insulated.
> You want 6.3 volt version when buying these for standard BHC.
> 
> https://www.ebay.com/itm/203513997654?hash=item2f62612956:g:olsAAOSw5VFWLiss
> ...



Just to strengthen the recommendation - I had Deyan build me several adapters and I am very, very satisfied with the products and entire process. Highly recommended instead of what I am reading above about dangerous, half-finished adapters.


----------



## GreenNeedle (Nov 18, 2021)

cddc said:


> Yeah, your case is the second case of Garage 1217 adapter shorting Crack chassis that I've seen here. Some Crack builders like to keep their 12AU7 socket low-profile, so they choose to mount it from the bottom of the chassis instead of to the top. Then, there won't be enough clearance for these exposed solder joints at the bottom of these Garage 1217 adapters, they will touch the metal chassis/screws and cause shorts.
> 
> Adding a plastic/rubber cylinder will protect against the exposed metal legs on top of the Garage 1217 adapters, but still the exposed solder joints at the bottom pose another threat to safety.
> 
> All in all, these Garage 1217 adapters lack of basic safety considerations (tubes are high voltage stuff in general, hence the exposed metal contacts pose huge threats), they are half-done products and should be avoided IMO.


I have one of each.  With the Garage one in its end cap the bit that would have been the top of the cap is cut but the curve left so it sits past the PCB and holds the adaptor up a mm or so from the noval socket without it being wobbly.

End cap is on the left, Garage adaptor in the middle and ebay adaptor on the right.


----------



## cddc

GreenNeedle said:


> I have one of each.  With the Garage one in its end cap the bit that would have been the top of the cap is cut but the curve left so it sits past the PCB and holds the adaptor up a mm or so from the noval socket without it being wobbly.
> 
> End cap is on the left, Garage adaptor in the middle and ebay adaptor on the right.




Why bother trying to fix a half-done product.  Your solution seems to fix most of the problems, but still there are exposed solder joints at the bottom, which can potentially short the screws on the chassis if you push down the Garage adapter too hard.

I don't think lots of people can complete the kind of fix-up that you did, nice workmanship though.


----------



## VanHai

cddc said:


> Why bother trying to fix a half-done product.  Your solution seems to fix most of the problems, but still there are exposed solder joints at the bottom, which can potentially short the screws on the chassis if you push down the Garage adapter too hard.
> 
> I don't think lots of people can complete the kind of fix-up that you did, nice workmanship though.


If you already have a lemon, then make lemonade out of it


----------



## cddc

VanHai said:


> If you already have a lemon, then make lemonade out of it




LOL...you made my day


----------



## Bonddam

New RCA Victor with a copper metal plate below the plate not sure what's the name but this tube so much better then regular RCA 6as7g. You can see the copper in the pic. Also lucky tube dead silent


----------



## cddc

Bonddam said:


> New RCA Victor with a copper metal plate below the plate not sure what's the name but this tube so much better then regular RCA 6as7g. You can see the copper in the pic. Also lucky tube dead silent




Nice find, RCA tubes with a Victor label indicate they are early production RCA tubes, normally in 40's or 50's I think, so they should be better than the late production RCA tubes in 60's and 70's.

RCA 6AS7Gs with copper skirts do not come up very often, these copper skirts look cool, they serve as RFI shielding, so should not affect the sound, but because this is an early production 6AS7G, I guess that's why you heard a  better sound.


----------



## Bonddam

Bought a bigger volume knob


----------



## davehg (Nov 25, 2021)

Not a Crack, but thought you’d enjoy this all-300b Bottlehead system. The Pre Bee 2 is just outstanding, and the amps are variations of an older Parabee design with Magnaquest nickel 2004 transformers and Mundorf Silver foil oil caps.


----------



## dstarr3

Anyone have any experience with the BHC and a Beyer 880/600?


----------



## Dawgfish

dstarr3 said:


> Anyone have any experience with the BHC and a Beyer 880/600?


I don't specifically for the 880/600 but I do with the T1 Gen2 which is 600 ohm also.  It's a match made in heaven.  I also use it with the DT1990 and Amiron Home (both 250 ohm).  It sounds great with anything above 150 ohm to my ears.  I bet it will sound great with your 880.


----------



## DenverW

dstarr3 said:


> Anyone have any experience with the BHC and a Beyer 880/600?


So I’m in a similar boat as dawgfish, as the 880 is pretty much the only beyer I haven’t tried.  Of all the beyer, including the T1, my favorite with the crack was the amiron home.  Sure the T1 is a better performer but the amiron had Greater  comfort and was good for movies and media.  The 990 and 770 weren’t nearly as impressive to me as the senheiser hd600 or 650, and I didn’t feel like the bhc made a significant difference compared to solid state amps. It didn’t seem to change the sound as much as the senns.   Ymmv of course!


----------



## cobrabucket (Dec 6, 2021)

Hey there! I recently sold a working Crack w/ SB. The buyer says that he is getting very low volume. I was wondering if this could be a bad tube? I gave him extra power and input tubes. I'm guessing I should ask him to try all tube configurations to see if that helps. Any other suggestions? As mentioned, I know this amp worked fine when I listened to it last week before listing it for sale. I am wondering if one of the tubes went bad or was damaged in shipping. Makes me nervous as I have never sold anything that didn't work as intended! The Crack came pre-assembled to me, so I have zero knowledge or skills in diagnosing anything wrong with the electronics but I suspect that it's tube-related. Does this sound like something that could happen with a bad tube? Any help would be greatly appreciated!


----------



## DenverW

cobrabucket said:


> Hey there! I recently sold a working Crack w/ SB. The buyer says that he is getting very low volume. I was wondering if this could be a bad tube? I gave him extra power and input tubes. I'm guessing I should ask him to try all tube configurations to see if that helps. Any other suggestions? As mentioned, I know this amp worked fine when I listened to it last week before listing it for sale. I am wondering if one of the tubes went bad or was damaged in shipping. Makes me nervous as I have never sold anything that didn't work as intended! The Crack came pre-assembled to me, so I have zero knowledge or skills in diagnosing anything wrong with the electronics but I suspect that it's tube-related. Does this sound like something that could happen with a bad tube? Any help would be greatly appreciated!


If he is getting sound in both channels, but low volume, it could be a tube that has gone bad.  Another thing to check would be the volume potentiometer to see if any wires have come loose.  Shipping is rough on these unless they're shipped in a very particular way; wrapped both ways with bubble wrap and then shipped upside down (resting on the top plate).  I've received pre made stuff in the mail in the past as part of trades and twice I've had screws come loose and wires detach.  

Does the buyer have any experience with building a kit?  If not, and it's NOT a tube, you may have a problem, because even if he can find the issue he may not be able to fix it.  I would recommend the following:

1.  Try a different combination of tubes
2.  check your chain to determine if something is off with input or output
2.  Check every wire connection to see if any wires had come loose during shipping, starting with the volume pot and the wires going to it


----------



## cobrabucket

Thank you. I will forward this to him and return with an update tomorrow. Cheers!


----------



## DenverW

The greatest resource is going to be the bottlehead forum.  Posts there get responses from the people at bottlehead to troubleshoot.  You can also post here and we'll help as much as we can.  Generally to diagnose an issue he'll need a voltometer in order to check voltages.  Hopefully its a tube, or an obvious issue like a missing wire.


----------



## cobrabucket

DenverW said:


> The greatest resource is going to be the bottlehead forum.  Posts there get responses from the people at bottlehead to troubleshoot.  You can also post here and we'll help as much as we can.  Generally to diagnose an issue he'll need a voltometer in order to check voltages.  Hopefully its a tube, or an obvious issue like a missing wire.


Yes. I posted there as well. I am hoping it's a tube or at worst, a loose volume cable. I know that with y'all's help we'll get it sorted!


----------



## cobrabucket

Guys, I think it's all sorted. It looks to have been a wire that came loose during shipment. He just need to re-solder the spot that had become disconnected. What a relief! I'll keep you posted if I have any more questions/ issues. Thanks everyone!


----------



## med666 (Dec 7, 2021)

Hi y’all. Quick question. I have a bhc with the sb upgrade. I love my bhc and what it does to the Senns 600 series.  I’m looking for another OTL amp that gets the same or similar sound out of the  600s series. It’s for someone who neither can build a crack nor has the real estate in their desk for such a big, chunker amp like the crack - otherwise, this person would get an already assembled crack… I know, the heresy!

I’ve read the Little Dot mk3 gets the job done but I would love to hear from folks who have done a comparison or own both. Other suggestions?

Thanks!


----------



## Dawgfish (Dec 7, 2021)

med666 said:


> Hi y’all. Quick question. I have a bhc with the sb upgrade. I love my bhc and what it does to the Senns 600 series.  I’m looking for another OTL amp that gets the same or similar sound out of the  600s series. It’s for someone who neither can build a crack nor has the real estate in their desk for such a big, chunker amp like the crack - otherwise, this person would get an already assembled crack… I know, the heresy!
> Thanks!


Schiit Valhalla would fit the bill.  It's an easy, low commitment (not having to build), and no fuss OTL tube amp with a smaller footprint than the Crack.  It sounds great with the HD600 family of cans.  I actually prefer the Valhalla over the Crack when paired with the HD6XX/650.  It's slightly brighter sound signature (which can be very much tempered with warmer sounding tubes if you are sensitive to brightness) really wakes up the 6XX/650.


----------



## davehg (Dec 9, 2021)

It’s amazing what a difference caps can make. In the 300b amp, things were amazing except the low end felt lightweight. Swapping the coupling caps for much larger Mundorf Silver Gold foil ones (same as the original only 75% larger) made a big difference - suddenly there was the missing low end weight. I am going to repurpose the remove caps for a Crack or Mainline build. Cap on the left replaced the one on the right.


----------



## Jonmakauu

davehg said:


> It’s amazing what a difference caps can make. In the 300b amp, things were amazing except the low end felt lightweight. Swapping the coupling caps for much larger Mundorf Silver Gold foil ones (same as the original only 75% larger) made a big difference - suddenly there was the missing low end weight. I am going to repurpose the remove caps for a Crack or Mainline build. Cap on the left replaced the one on the right.


Any link as to where I can get mundorf caps?


----------



## davehg

Parts connexxion:


Jonmakauu said:


> Any link as to where I can get mundorf caps?


https://www.partsconnexion.com/


----------



## buencamino

DenverW said:


> What are the stock tubes you have now?


Just the ones that came with the stock equipment. It says here on the instruction manual, 6080 vacuum tube, and a 12AU7 vacuum tube. are there any recommended tubes to upgrade? preferably something with soundstage as that's what I noticed that disappeared when I used the crack.. but any nice tubes to experiment with would be nice too, just want to see what's out there and listen to different sound signatures. Many thanks.


----------



## L0rdGwyn

buencamino said:


> hey, fairly new to OTL tube amps and assembled a crack a few months ago. Actually the experience with the HD800S I have is kind of underwhelming. Sounded pretty normal to me, despite all the hype the crack gets with senns cans. Was just wondering maybe I should change the stock tubes? I have no experience with tube rolling, but if it could improve the sound a bit (especially the soundstage, I mean the crack just took away all the soundstage my HD800S had..). Any advice from experienced users would be nice. Thanks in advance. Oh I use a Aune X8 dac magic as my dac with burson vivid op amps.



Is this with or without the Speedball upgrade?


----------



## buencamino

L0rdGwyn said:


> Is this with or without the Speedball upgrade?


yup without


----------



## L0rdGwyn

buencamino said:


> yup without



I think you'll find adding the Speedball will get you more of the soundstage you are looking for.  Changing the power tube to a Tung-Sol 5998 will take it even a step further.


----------



## buencamino

L0rdGwyn said:


> I think you'll find adding the Speedball will get you more of the soundstage you are looking for.  Changing the power tube to a Tung-Sol 5998 will take it even a step further.


Oh ok, the reason I didn't get it was that bottlehead support on fb chat told me just to get the basic one.. is the speedball really a big difference? which is the power tube? the big one in the middle?


----------



## buencamino

Bonddam said:


> New RCA Victor with a copper metal plate below the plate not sure what's the name but this tube so much better then regular RCA 6as7g. You can see the copper in the pic. Also lucky tube dead silent


is that balanced output for the crack? Is that possible?


----------



## L0rdGwyn

buencamino said:


> Oh ok, the reason I didn't get it was that bottlehead support on fb chat told me just to get the basic one.. is the speedball really a big difference? which is the power tube? the big one in the middle?



Yes it is a big difference, and the big tube is the power tube.  Balanced output is not possible with the Crack as it is a single ended amplifier, but you could change the output connector to XLR, which is what was done in the post above.


----------



## buencamino

L0rdGwyn said:


> Yes it is a big difference, and the big tube is the power tube.  Balanced output is not possible with the Crack as it is a single ended amplifier, but you could change the output connector to XLR, which is what was done in the post above.


Alright.. thanks ill check the things you said out.. oh so the xlr connection is purely for  aesthetic purposes..


----------



## Bonddam

buencamino said:


> is that balanced output for the crack? Is that possible?


No just convince. You don’t have noise from plugging and unplugging from pins touching.


----------



## buencamino

Bonddam said:


> No just convince. You don’t have noise from plugging and unplugging from pins touching.


Whats convince?


----------



## Bonddam

Convenience was word I was using. The stupid correction on my phone is thinking I am choosing wrong word.


----------



## buencamino

Bonddam said:


> Convenience was word I was using. The stupid correction on my phone is thinking I am choosing wrong word.


oh got it, what tubes do you use?


----------



## Bonddam

RCA 6as7g victor and RCA6sn7gtb


----------



## buencamino

Bonddam said:


> RCA 6as7g victor and RCA6sn7gtb


are they good? where did u buy them? thanks


----------



## dstarr3




----------



## L0rdGwyn

buencamino said:


> Alright.. thanks ill check the things you said out.. oh so the xlr connection is purely for  aesthetic purposes..



It's just a connector preference, XLR is meant to be used in balanced gear but can be wired for single-ended.


----------



## Galapac

buencamino said:


> Oh ok, the reason I didn't get it was that bottlehead support on fb chat told me just to get the basic one.. is the speedball really a big difference? which is the power tube? the big one in the middle?


For what it’s worth, my BHC was quiet without the speedball and I am slowly adding it in now. I went for the Black Friday deal and said why not. I did the first part and you get more dynamic sound from the BHC so it is definitely worth it. I will finish the second part this weekend but if you built the crack and your voltages check out, then the upgrade is a snap.

If you cannot afford a 5998 tube there are decent Mullard 6080s too that sound decent.
I use either a 5998 or Bendix 6080WB but I got them before prices went to unobtanium status.


----------



## Bonddam

buencamino said:


> are they good? where did u buy them? thanks


Best/Worst place but I lucked out… eBay.
The Victor was biggest leap of faith couldn’t believe it was quite. The 6sn7 stuff I buy from Bullz Tubez. Bullz Tubez has been good 4 out 4 purchase perfect using that seller. All my 6sn7 are dead silent sound amazing. I also buy from another seller in Vietnam and lucked out on pair Ken Rad chrome tops V231 see those on the Woo.


----------



## jonathan c

Bonddam said:


> Best/Worst place but I lucked out… eBay.
> The Victor was biggest leap of faith couldn’t believe it was quite. The 6sn7 stuff I buy from Bullz Tubez. Bullz Tubez has been good 4 out 4 purchase perfect using that seller. All my 6sn7 are dead silent sound amazing. I also buy from another seller in Vietnam and lucked out on pair Ken Rad chrome tops V231 see those on the Woo.


I agree with you about Bullz Tubez 👍👍


----------



## ColdsnapBry

So what are some good starter NOS tubes for the Bottlehad Crack that are not too hard to find and reasonably priced?


----------



## DenverW

For power tubes I would recommend the rca 6as7g, the tung sol 6as7g, or the 7236 tube.  They can all be found at reasonable prices, so if you see what seems an excessively high priced one just move on.

For input tubes I would say a older rca/victor 12au7, a Siemens silver plate 12au7, or a 6sn7 adapter and one of the tubes that interests you from the 6sn7 reference thread.


----------



## jonathan c

Cetron 7236 for the power (back) tube. RFT ECC82 for the driver (front) tube. [The ECC82 is the European 12AU7.]


----------



## DenverW

There is a post in the classifieds selling many different 6sn7 tubes.  I would recommend having the speedball upgrade and make sure to NEVER put them in the power tube slot.  You must use a 6sn7 to 12au7 adapter.  Although they fit in the 6080 tube slot they are not compatible.


----------



## Dawgfish

Good tube suggestions guys!   I'm getting really good sound right now with a Chatham (Tung-Sol) 6AS7 for the power tube and a CBS-Hytron 5814 for the input tube.  This combo has very good synergy with the Cocobolo Auteur.  When I'm listening to the T1 Gen 2 I like the RCA Black Plate 6AS7 and Mullard 12AU7/EC82. This tube combo sounds great with the HD6XX family of cans also.  I haven't tried the Chatham/CBS-Hytron combo with the 600 family yet but it will probably pair well with them also.  I've got next week off so I will know soon! Lol!


----------



## Amish

I really want to build one of these amps. I might just have to pull the trigger sometime.


----------



## cddc

DenverW said:


> For power tubes I would recommend the rca 6as7g, the tung sol 6as7g, or the 7236 tube.  They can all be found at reasonable prices, so if you see what seems an excessively high priced one just move on.
> 
> For input tubes I would say a older rca/victor 12au7, a Siemens silver plate 12au7, or a 6sn7 adapter and one of the tubes that interests you from the 6sn7 reference thread.




Good recommendations! 

Tung Sol 5998 is also one of the best power tubes to consider, if the budget can be stretched a little bit, so does Bendix 6080. I've rolled almost all the power tubes available to Crack over the years, someday when I get the time and energy I may write a summary on them.

For input tubes, there are just too many choices/flavors, 12AU7 / 6SN7 / 7N7 / 7AF7 / 12BH7 / 6CG7 / etc. If you like the 12AU7 family tubes, you can also try the dual 6C4 tubes with an adapter, it's 12AU7 equivalent.


----------



## bagwell359

L0rdGwyn said:


> It's just a connector preference, XLR is meant to be used in balanced gear but can be wired for single-ended.


Yes.  Every can I have has a balanced connection, so... Also unless u use locking SE connections - balanced has a more stable connection.


----------



## L0rdGwyn

bagwell359 said:


> Also unless u use locking SE connections - balanced has a more stable connection.



Then you can go mountain biking with your BHC in a backpack


----------



## Lovebox

Bonddam said:


> Bought a bigger volume knob


Link ?


----------



## skhan007

I'll rotate different tubes in every now and then and listen for a couple of months. Right now, I've got the slotted Bendix in the power tube position and wow, the low end response is just great with tube! Still hoping to find a reasonably priced 5998 one day to test drive.


----------



## raindownthunda

skhan007 said:


> I'll rotate different tubes in every now and then and listen for a couple of months. Right now, I've got the slotted Bendix in the power tube position and wow, the low end response is just great with tube! Still hoping to find a reasonably priced 5998 one day to test drive.


Which weighs more: the Bendix or the stone chassis? This pic screams heavy duty!


----------



## skhan007

raindownthunda said:


> Which weighs more: the Bendix or the stone chassis? This pic screams heavy duty!


I take my hard rock very seriously.


----------



## raindownthunda

skhan007 said:


> I take my hard rock very seriously.


Maybe you can convince Zach to make a ZMF hand-chiseled from stone


----------



## skhan007 (Jan 9, 2022)

raindownthunda said:


> Maybe you can convince Zach to make a ZMF hand-chiseled from stone


Well, kind of funny that you mention Zach! I just took delivery yesterday of these beautiful Camphor Burl ltd. ZMF Verite Open cans. I’ve only had about 24 hours with them so far, but holy smokes, the low and extension and slam are head and shoulders above my Auteur.

There is some kind of magic synergy between the BHC speedball, NOS tubes, and ZMF cans. It’s completely undeniable and readily apparent. This amp drives these cans into sonic perfection. The frequency range and response is amazing. Huge, I tell you!

In all my research, the Verite are supposed to be endgame level headphones. I’ll be putting them through the paces over the next several weeks to see. I was really torn between these and the Utopia, but the latter would not be a match for the BHC speedball. I believe the Utopia need to have a different kind of amp for impedance matching, or so I’m told. I went with the cans that would be the best match for what I currently have. So far, so good! Many more hours of listening to follow to confirm that these are endgame headphones.


----------



## GreenNeedle

skhan007 said:


> I'll rotate different tubes in every now and then and listen for a couple of months. Right now, I've got the slotted Bendix in the power tube position and wow, the low end response is just great with tube! Still hoping to find a reasonably priced 5998 one day to test drive.


Isn't the Bendix supposed to be much better (or at least much more expensive) than the 5998?  Or are you just wanting to compare 2 highly regarded tubes against each other?


----------



## skhan007

GreenNeedle said:


> Isn't the Bendix supposed to be much better (or at least much more expensive) than the 5998?  Or are you just wanting to compare 2 highly regarded tubes against each other?


Yes, curious to compare more than anything.


----------



## DenverW

GreenNeedle said:


> Isn't the Bendix supposed to be much better (or at least much more expensive) than the 5998?  Or are you just wanting to compare 2 highly regarded tubes against each other?


I think it is a preference thing, as well as what tubes they're paired with.  I preferred the 5998 sound over the bendix 6080wb, personally.  They're both good tubes, though.  I've noticed both around the same price point, however the bendix can be slightly higher, so you are correct on that end.


----------



## ColdsnapBry (Jan 16, 2022)

You can sand down the base and start over, right? Not really happy with my end stain and I want to go with a black stain instead of brown.


----------



## L0rdGwyn

ColdsnapBry said:


> You can sand down the base and start over, right? Not really happy with my end stain and I want to go with a black stain instead of brown.



You might not be able to sand down far enough - wood is porous, the stain seeps down into the pores of the wood.  Likely there will be residual stain even if you sand off a decent amount of the top layer, and that will likely affect the new stain appearance.  If you really want to start from scratch, would be best to order a new base from Bottlehead.


----------



## skhan007

ColdsnapBry said:


> You can sand down the base and start over, right? Not really happy with my end stain and I want to go with a black stain instead of brown.


Absolutely. You can also build a new base as many people have, from exotic woods, or in my case I had one made in granite. Make it your own! I think there are many great photos on this thread, you could check out for ideas.


----------



## Galapac

ColdsnapBry said:


> You can sand down the base and start over, right? Not really happy with my end stain and I want to go with a black stain instead of brown.


Yes you can if the stain didn't penetrate too deep and where you are going from brown to a darker black you should be ok.
Just be careful on the corners as to not round them off as it is a soft wood.
You can also just buy the wood panels separately from Bottlehead as an option but it's like $50 so not cheap.


----------



## L0rdGwyn

@Galapac is right, going from brown to black it might work out okay!


----------



## skhan007

Question about the 100 uf output caps (and apologies if it's been answered. This thread is massive and it's a bit of a challenge to find the answer to my question):

I'm hearing a blurry presentation of the high end frequencies, in terms of detail and separation. I'm understanding that I should upgrade the 100 uf output caps to film caps of a different value. Can anyone recommend specifics? I don't necessarily need more high end, but rather just better detail within the high end. For example, my solid state ADI-2 DAC/amp does this in spades, but doesn't have the pleasing low-end like the BHC. Thanks in advance.


----------



## L0rdGwyn

skhan007 said:


> Question about the 100 uf output caps (and apologies if it's been answered. This thread is massive and it's a bit of a challenge to find the answer to my question):
> 
> I'm hearing a blurry presentation of the high end frequencies, in terms of detail and separation. I'm understanding that I should upgrade the 100 uf output caps to film caps of a different value. Can anyone recommend specifics? I don't necessarily need more high end, but rather just better detail within the high end. For example, my solid state ADI-2 DAC/amp does this in spades, but doesn't have the pleasing low-end like the BHC. Thanks in advance.



Hi - so changing the capacitors will not change the high-frequency response in any measurable way, in fact the output capacitors more drastically affect the low frequency response.  However, it's possible you might appreciate some subjective changes in the presentation of the high frequencies by changing capacitors.  If you wanted to do that, you would be looking for 100uF (or larger) rated for 200VDC or higher.  Note that a 100uF film cap is pretty massive, so fitting them inside the chassis can be a challenge.  Capacitance in parallel adds, so alternatively you could use two 50uF caps in parallel (47uF would be a more standard value), or three 33uF caps in parallel.  As far as brands, I personally like ClarityCaps, but you will hear different favorites from different people.


----------



## bagwell359

L0rdGwyn said:


> Hi - so changing the capacitors will not change the high-frequency response in any measurable way, in fact the output capacitors more drastically affect the low frequency response.  However, it's possible you might appreciate some subjective changes in the presentation of the high frequencies by changing capacitors.  If you wanted to do that, you would be looking for 100uF (or larger) rated for 200VDC or higher.  Note that a 100uF film cap is pretty massive, so fitting them inside the chassis can be a challenge.  Capacitance in parallel adds, so alternatively you could use two 50uF caps in parallel (47uF would be a more standard value), or three 33uF caps in parallel.  As far as brands, I personally like ClarityCaps, but you will hear different favorites from different people.


Yes the Clarity caps are very nice and the 100 uF is very large.  Looks like two pontoons under the base.  Either need a custom base, put them outside, or install in such a way as its easy to remove them (my way) to do other work, because they will block about 70% of the undersides when installed inside the dimensions of the frame.

If you do put 2 or more together to get to 100, test the combos so they match as well as possible before you solder or link them up so you a. get the best match and b. so you don't have to have neurotic concern that you have a 101 paired with a 97.

I've been upgrading caps since the Hafler DH100 days, DQ10, various Maggies... and especially for HF audio they can make a notable and fine difference.  Never got as far as the Duelands, but pretty far into the upper end.  Enjoy!


----------



## DeweyCH

L0rdGwyn said:


> Hi - so changing the capacitors will not change the high-frequency response in any measurable way, in fact the output capacitors more drastically affect the low frequency response.  However, it's possible you might appreciate some subjective changes in the presentation of the high frequencies by changing capacitors.  If you wanted to do that, you would be looking for 100uF (or larger) rated for 200VDC or higher.  Note that a 100uF film cap is pretty massive, so fitting them inside the chassis can be a challenge.  Capacitance in parallel adds, so alternatively you could use two 50uF caps in parallel (47uF would be a more standard value), or three 33uF caps in parallel.  As far as brands, I personally like ClarityCaps, but you will hear different favorites from different people.


Do you have a recommended vendor for sourcing film caps? I've been looking through partsconnexion's website. Also, among ClarityCaps options, would you be able to compare the PX vs. CSA vs. SA series? I know the SA series has a higher voltage rating, but all 3 are well over the recommended minumum.

Oh, and last question (sorry), is there any audible benefit or detriment to three 33uF caps in parallel vs. a single 100uF cap?

Gracias muy mucho.


----------



## L0rdGwyn

DeweyCH said:


> Do you have a recommended vendor for sourcing film caps? I've been looking through partsconnexion's website. Also, among ClarityCaps options, would you be able to compare the PX vs. CSA vs. SA series? I know the SA series has a higher voltage rating, but all 3 are well over the recommended minumum.
> 
> Oh, and last question (sorry), is there any audible benefit or detriment to three 33uF caps in parallel vs. a single 100uF cap?
> 
> Gracias muy mucho.



Hey - depends on what brand you are after, but Partsconnexion is one option, Sonic Craft is another.  Despite their being located in the UK (I'm in the USA), I buy a lot of parts from Hificollective.  They have a great selection, organized site with up-to-date inventory (this last part is sometimes a problem with Partsconnexion).

I can't really comment on all of the different brands head-to-head as I haven't compared them that way.  I will say I have used the TC, ESA, CSA, and CMR all with good results.  Thing is, using a higher voltage rated cap than is needed is going to mean a bigger cap.  The 250VDC PX, ESA, CSA might get you more capacitance for the size than say, a 400VDC CMR or 630VDC SA.  Since size considerations are important for modding the Crack, I would shoot for a 250VDC rated cap if going with ClarityCap.

Theoretically, using caps in parallel would getting you closer to the "ideal" capacitor, so there might be audible benefits.  I will say that in one of my amplifiers, I tested this and found two caps in parallel sounded better than a single cap of equivalent capacitance.  I also found that using caps of unequal values resulted in worse sound than two caps of equal value or a single cap.

So for example, to get a total capacitance of 6.6uF, two 3.3uF caps in parallel sounds better than one 6.6uF cap, which sounds better than one 2.2uF in parallel with one 4.4uF cap (these are nonstandard values, just an example).

YMMV of course, this was just from one series of listening tests I did for a particular design, which happened to be a parafeed output.


----------



## skhan007

L0rdGwyn said:


> Hi - so changing the capacitors will not change the high-frequency response in any measurable way, in fact the output capacitors more drastically affect the low frequency response.  However, it's possible you might appreciate some subjective changes in the presentation of the high frequencies by changing capacitors.  If you wanted to do that, you would be looking for 100uF (or larger) rated for 200VDC or higher.  Note that a 100uF film cap is pretty massive, so fitting them inside the chassis can be a challenge.  Capacitance in parallel adds, so alternatively you could use two 50uF caps in parallel (47uF would be a more standard value), or three 33uF caps in parallel.  As far as brands, I personally like ClarityCaps, but you will hear different favorites from different people.


Thank you for this information. So, if I understand correctly, adding some good 100 uf caps might help with my subjective interpretation of high frequencies? The big question, before I order caps, install new terminals, and apply this mod, is - Do we think this will add definition to the high frequencies and reduce the "blurry" softening of those frequencies? If not, I'll just stick with the stock BHC and consider the sound part of it's "charm". 

I found this pic on another forum and this person used the Dayton 100uf caps:


----------



## L0rdGwyn

skhan007 said:


> Thank you for this information. So, if I understand correctly, adding some good 100 uf caps might help with my subjective interpretation of high frequencies? The big question, before I order caps, install new terminals, and apply this mod, is - Do we think this will add definition to the high frequencies and reduce the "blurry" softening of those frequencies? If not, I'll just stick with the stock BHC and consider the sound part of it's "charm".



Potentially, yes, perhaps the capacitor will impart a new sound, but the measured high frequency response will be the same.  Sorry, I can't commit to saying the "blurriness" will be improved with a cap change, maybe someone else who has added in film caps to their BHC recently can comment on how it affected the sound in theirs.


----------



## DenverW

I found that good tubes had a greater impact than good capacitors over all.  That being said, I still upgraded both.


----------



## skhan007

L0rdGwyn said:


> Potentially, yes, perhaps the capacitor will impart a new sound, but the measured high frequency response will be the same.  Sorry, I can't commit to saying the "blurriness" will be improved with a cap change, maybe someone else who has added in film caps to their BHC recently can comment on how it affected the sound in theirs.


Thank you- After doing some more reading and making some level adjustments, I have concluded that I had too much input gain going into the BHC from my ADI-2 DAC. I had read elsewhere that people recommended the reference level of the ADI-2 DAC should be at +7 dBu and the meters should be just below clipping (usually with the volume set to 0 dBr). In doing so, I would have the BHC volume at about 8-9 O'Clock and it was getting loud. I think I was introducing some distortion which introduced the blurriness and loss of clarity I had described. Now with much different output levels on my ADI-2 DAC, I hear much better clarity.


----------



## L0rdGwyn

skhan007 said:


> Now with much different output levels on my ADI-2 DAC, I hear much better clarity.



Glad to hear it, that's a lot less work!


----------



## skhan007

Two questions for my crack friends here:

1) Regarding power tubes, I have (and really enjoy) the Bendix and GEC 6080 and the lovely Chatham 6as7g big bottle. In your opinion(s), do you feel the 5998 will offer anything more/different/better?

2) I’d like to get a nice volume knob, preferably in aluminum, steel, or something if that nature. Any suggestions or links?


----------



## Galapac

1) 5998 is a nice tube that I use exclusively as a power tube in my BHC although the GEC 6080 is nice too, I just prefer the 5998 a little more.

2) Try amazon or partsconnexion
https://www.partsconnexion.com/cgi-...d0a875b77f1157d6bb78322a865&search_field=Knob


----------



## DenverW

1) The 5998 tube for me tended towards being a bit brighter than your 6080, with more clarity and sparkle.  Great tube.

2) The only thing I had to figure out when putting a new volume knob in is how long the new know can accept.  I got one where I had to saw off part of the potentiometer to make it fit.  Other than that you're all good.


----------



## raindownthunda

skhan007 said:


> Two questions for my crack friends here:
> 
> 1) Regarding power tubes, I have (and really enjoy) the Bendix and GEC 6080 and the lovely Chatham 6as7g big bottle. In your opinion(s), do you feel the 5998 will offer anything more/different/better?
> 
> 2) I’d like to get a nice volume knob, preferably in aluminum, steel, or something if that nature. Any suggestions or links?


1) I wouldn’t say better, but different. Worth having to experiment with? I’d say yes, especially as you could probably try it out and sell it without much of a loss if not your flavor. Compared to the Chatham (which is my favorite lately) I’d say the 5998 is more energetic/forward/brighter and the Chatham more relaxed/more euphonic decay. I would make a rough comparison the GEC 6080 is somewhere in between the two.

2) +1 for PartsConnexion. I highly recommend the AudioNote knobs. Pricey but very high quality and heavy/smooth feel. Fits perfectly on Alps Blue Velvet (I think the same as the stock pot but you should double check the shaft diameter/length works). Here is the 25mm gloss black AudioNote knob currently in my BHC:


----------



## Galapac

raindownthunda said:


> 1) I wouldn’t say better, but different. Worth having to experiment with? I’d say yes, especially as you could probably try it out and sell it without much of a loss if not your flavor. Compared to the Chatham (which is my favorite lately) I’d say the 5998 is more energetic/forward/brighter and the Chatham more relaxed/more euphonic decay. I would make a rough comparison the GEC 6080 is somewhere in between the two.
> 
> 2) +1 for PartsConnexion. I highly recommend the AudioNote knobs. Pricey but very high quality and heavy/smooth feel. Fits perfectly on Alps Blue Velvet (I think the same as the stock pot but you should double check the shaft diameter/length works). Here is the 25mm gloss black AudioNote knob currently in my BHC:


  Nice! What custom wood is that?


----------



## raindownthunda

Galapac said:


> Nice! What custom wood is that?


Thanks - wood is ziricote. Inspired by the ziricote wood ZMF Aeolus I got a few years back. One of my first woodworking projects, Zach helped me out with tips on the finish process as I wanted them to match the ear cups as closely as possible. Didn’t turn out perfect, but I’m happy with it . I posted a bunch of pics in this gallery a while back: https://imgur.com/a/uATdg3g


----------



## skhan007

Thanks, Gents! I will source a nicer volume knob and further adorn my already beautiful BHC with more stunning appointments.

Regarding the 5998:

If any of you would be kind enough to help me identify a source to purchase one (at hopefully, at a non-price gouging dollar amount) I would be most appreciative. Furthermore, if one of you happen to have one that you are not currently using and would be generously willing to allow me to purchase and try it out, I would be immensely thankful. Feel free to PM and I'm happy to follow up.


----------



## skhan007

Thanks to another Head-Fier, I have a nice NOS Chatham 5998!! 

I’ve only had a short time with it tonight, but I immediately hear very clear upper midrange, airy and crisp highs, and a nice push to vocals. Very, very smooth on the bass frequencies. I’m most impressed with the clarity in the treble frequencies. Some of the above descriptions were spot-on.

I’ll give it many days if listening coming up, but I feel so far this has taken my BHC up a notch!


----------



## DenverW

skhan007 said:


> Thanks to another Head-Fier, I have a nice NOS Chatham 5998!!
> 
> I’ve only had a short time with it tonight, but I immediately hear very clear upper midrange, airy and crisp highs, and a nice push to vocals. Very, very smooth on the bass frequencies. I’m most impressed with the clarity in the treble frequencies. Some of the above descriptions were spot-on.
> 
> I’ll give it many days if listening coming up, but I feel so far this has taken my BHC up a notch!


Lol!  So you're saying my incredibly in depth review with multiple comparisons was helpful?  

I may be good at some things, but reviewing gear is NOT one of them .  Glad you like the tube!  Now...time to tempt you with the 421A.


----------



## Galapac

DenverW said:


> Glad you like the tube! Now...time to tempt you with the 421A.


Oh the proverbial rabbit hole...let's not forget the Bendix 6080WB slotted...


----------



## skhan007

Galapac said:


> Oh the proverbial rabbit hole...let's not forget the Bendix 6080WB slotted...


Yeah- got that one already! It's a good one, as well. I'll post a nice family photo later on, but having fun with different tubes in the power section. Oddly, I've been totally satisfied with the clear top RCA in the input position. I've felt no need to touch that one!


----------



## Galapac

skhan007 said:


> Thanks to another Head-Fier, I have a nice NOS Chatham 5998!!
> 
> I’ve only had a short time with it tonight, but I immediately hear very clear upper midrange, airy and crisp highs, and a nice push to vocals. Very, very smooth on the bass frequencies. I’m most impressed with the clarity in the treble frequencies. Some of the above descriptions were spot-on.
> 
> I’ll give it many days if listening coming up, but I feel so far this has taken my BHC up a notch!


Congrats to you on scoring a great tube!
So any preference for the 5998 or 6080? To me I like them both and they are just different.
It depends on your ears, your mood, music genre, etc...
You may find that certain 12AU7 and their equivalents may or may not mate better with the 5998 but that's the fun of tube rolling, enjoy!


----------



## skhan007

Galapac said:


> Congrats to you on scoring a great tube!
> So any preference for the 5998 or 6080? To me I like them both and they are just different.
> It depends on your ears, your mood, music genre, etc...
> You may find that certain 12AU7 and their equivalents may or may not mate better with the 5998 but that's the fun of tube rolling, enjoy!


Thanks- It's hard to know so soon, but I plan on clocking a lot of hours listening this weekend. My quick observation after < 24 hours with it, is that I'm very impressed with the clarity. There is less pronounced bass, which is fine with me, as I'm mostly focused on details in the treble frequencies, such as cymbals, snare, snap of rack toms, keyboards, strings, etc. This tube, so far, sounds the most accurate and "solid state" of any other tubes I've used, meaning that it does not soften the frequencies. Thus, less warmth (in a good way) and less blending of sounds. Better separation, in other words. 

As I'm spending more time with the BHC (less than a year owning it and rolling tubes), I think I'm a clinical listener and not gravitating to warm, second order harmonics/distortion, and "relaxed" tubey presentation. I think I'm liking accuracy, detail, separation, and staging. Completely the opposite of my life as a guitarist using tube amps exclusively. 

I'll compare with my 6080 and 6AS7G tubes and get back with thoughts.


----------



## DenverW

You can pair it with a complementary input tube that has a bit more warmth and bottom end to really round it out.  Some of the mullard 12au7, amperex (especially the very old ones), or a 6sn7 with a little body like a grey glass rca.


----------



## skhan007

Power tube family photo...

L to R: 

1959 Chatham 5998 domino plate; pair of matched 1960 Chatham 6AS7G; 1962 slotted Bendix 6080; pair of matched 1963 GEC 6080.

Right now, it's the honeymoon phase with the 5998. Listened for about 3 hours this morning and I like this tube better (so far, honeymoon phase mind you!) than any of the others. If that holds true over the next month or so, I don't see any of these other tubes getting any amp time. We shall see...


----------



## CaptainFantastic

@L0rdGwyn I have a quick question. I know in the past you used Audio Note knobs on your Crackatwoa build. I bought one for my Crack. I noticed that it cannot sit flat on the top plate. It's too heavy and makes for a messy volume control. So it has to sit higher up a bit, as in your photos of the Crackatwoa. My question is - did you use any washer or anything between the knob and the plate? Mine seems to stay on just fine, but as I turn it the gap distance varies, no matter how straight I try to fix it on. A bit annoying.

Thanks!


----------



## L0rdGwyn

CaptainFantastic said:


> @L0rdGwyn I have a quick question. I know in the past you used Audio Note knobs on your Crackatwoa build. I bought one for my Crack. I noticed that it cannot sit flat on the top plate. It's too heavy and makes for a messy volume control. So it has to sit higher up a bit, as in your photos of the Crackatwoa. My question is - did you use any washer or anything between the knob and the plate? Mine seems to stay on just fine, but as I turn it the gap distance varies, no matter how straight I try to fix it on. A bit annoying.
> 
> Thanks!



Hey!  The question is, what is causing the crookedness?  Is the shaft of the pot crooked, or is the bored hole in the knob crooked?  Is the knob aligned vertically?  Have you noticed the unevenness of the pot when using a different knob?  If it's the knob, replacing it may fix the issue, if the shaft of the pot is crooked (or it is mounted crooked), then the pot could be replaced or the mounting adjusted.  A pot with a straight shaft mounted perpendicular to the top plate with a properly aligned knob shouldn't cause any issues with unevenness.  I didn't use any washers or anything on the Crackatwoa that I can remember.


----------



## CaptainFantastic

L0rdGwyn said:


> Hey!  The question is, what is causing the crookedness?  Is the shaft of the pot crooked, or is the bored hole in the knob crooked?  Is the knob aligned vertically?  Have you noticed the unevenness of the pot when using a different knob?  If it's the knob, replacing it may fix the issue, if the shaft of the pot is crooked (or it is mounted crooked), then the pot could be replaced or the mounting adjusted.  A pot with a straight shaft mounted perpendicular to the top plate with a properly aligned knob shouldn't cause any issues with unevenness.  I didn't use any washers or anything on the Crackatwoa that I can remember.



Thanks for the detailed answer! It must be the knob, because the stock Crack knob sits just fine and the shaft of the pot does not seem crooked at all.

Disappointed with the Audio Note quality on this particular item. It also came in with "seconds" finish quality, despite purchasing it brand new. I will see if they can send a replacement.


----------



## pravous

CaptainFantastic said:


> @L0rdGwyn I have a quick question. I know in the past you used Audio Note knobs on your Crackatwoa build. I bought one for my Crack. I noticed that it cannot sit flat on the top plate. It's too heavy and makes for a messy volume control. So it has to sit higher up a bit, as in your photos of the Crackatwoa. My question is - did you use any washer or anything between the knob and the plate? Mine seems to stay on just fine, but as I turn it the gap distance varies, no matter how straight I try to fix it on. A bit annoying.
> 
> Thanks!


Maybe a shaft diameter mismatch?  If the Audio note volume knob has a larger diameter hole than your potentiometer shaft the set screws might force it off kilter. They do sell sleeves/bushings if that is the case.


----------



## CaptainFantastic

pravous said:


> Maybe a shaft diameter mismatch?  If the Audio note volume knob has a larger diameter hole than your potentiometer shaft the set screws might force it off kilter. They do sell sleeves/bushings if that is the case.



Thanks, something to keep in mind for the future for sure. In this case the diameter is the same as the old, stock knob. The AudioNote is 6mm diameter shaft, and so is the stock Crack pot shaft I believe.


----------



## jonathan c

CaptainFantastic said:


> Thanks, something to keep in mind for the future for sure. In this case the diameter is the same as the old, stock knob. The AudioNote is 6mm diameter shaft, and so is the stock Crack pot shaft I believe.


6mm is a standard for cylindrical pot shafts.


----------



## skhan007

DenverW said:


> Now...time to tempt you with the 421A.


So, I did some searching on Head-Fi and elsewhere and apparently, supposedly, allegedly, the 421a is identical to the 5998. Maybe there's a different location for the getter, I'm not sure. But it sounds like the 421a is a rare, high-priced, equivalent? No difference in sound reported in several posts, but a few have stated they hear superiority in the 421a.


----------



## anjaudiofile

ironbut said:


> Maybe the subject heading is a little confusing for folks that aren't used to Doc Bottlehead's tendency for naming his DIY kits a little differently than the run of the mill audio company.
> 
> Doc's just announced a new OTL headphone kit called "Crack". If you've ever been interested in developing some soldering skills and learn about what's going on inside of a tube amp, Bottlehead kits are a great place to start.
> The fantastic part about this all tube design is the whole kit just costs $200!
> ...


Hey man, I have been really interested in the Bottlehead Crack. I love the DIY nature of it, but aside from my computer, I haven't put electronics together before. Seems like I'll need to pick up a soldering iron, but what else would I need to get started?


----------



## DenverW

skhan007 said:


> So, I did some searching on Head-Fi and elsewhere and apparently, supposedly, allegedly, the 421a is identical to the 5998. Maybe there's a different location for the getter, I'm not sure. But it sounds like the 421a is a rare, high-priced, equivalent? No difference in sound reported in several posts, but a few have stated they hear superiority in the 421a.


It’s an ongoing discussion.  I’ve had both, and currently have two different versions of the 421a.  It is not a match structurally or sonically to the 5998.  I’m in the ‘not the same’ boat.


----------



## DenverW

anjaudiofile said:


> Hey man, I have been really interested in the Bottlehead Crack. I love the DIY nature of it, but aside from my computer, I haven't put electronics together before. Seems like I'll need to pick up a soldering iron, but what else would I need to get started?


You’ll need wood glue for the base, as well as stain or paint depending how you want to make it.  For the kit you’ll need wire strippers, wire cutters, and some needle nose pliers.  Besides the soldering iron, solder, and solder remover.  It sounds like a lot at first, but it’s really not, and I’ve used the gear on every DIY project since.

Everyone, am I forgetting anything?  Second hand tool perhaps, with a magnifying glass.


----------



## raindownthunda (Feb 9, 2022)

DenverW said:


> You’ll need wood glue for the base, as well as stain or paint depending how you want to make it.  For the kit you’ll need wire strippers, wire cutters, and some needle nose pliers.  Besides the soldering iron, solder, and solder remover.  It sounds like a lot at first, but it’s really not, and I’ve used the gear on every DIY project since.
> 
> Everyone, am I forgetting anything?  Second hand tool perhaps, with a magnifying glass.


You also need a basic multimeter to test voltage. I’d also recommend a practice soldering project to build your confidence in soldering (many options available, Here is one I got). The bottlehead crack was my gateway drug electronics project and I’ve used the tools I purchased for my build in countless projects since.

Here are links to all of the tools I bought that I would recommend in a heartbeat:

Wire cutter (diagonal)
Bent nose pliers - highly recommended!
Needle nose pliers
Silicone soldering mat
Multimeter
Solder station
Wire stripper
Solder .6mm
De-solder wick (for removing excess solder)
I didn’t use a magnifying glass and didn’t have any issues, but some might find it useful. I also bought a “helping hands” station which I found to be somewhat cumbersome and mostly just soldered directly on the solder mat.

edit: I just checked the links I posted and some of the items seems to have gone up in price. I think you can search and find comparable tools (like the bent nose pliers) for cheaper than the specific ones I got that should work just as well.


----------



## DenverW

Multimeter!  That’s what I forgot.  Essential, and you can get a decent one for very little.


----------



## pravous

I second the warm up solder project motion.  I used minty boost kit from adafruit. It was simple enough that my kids actually ended up making them. More importantly it gave me confidence and experience with both a soldering iron and multimeter.


----------



## skhan007

Once you guys have found your optimal tubes, do you keep all the other ones you’ve collected? Now that I’m in club 5998, I’m not sure I’ll go back to anything else! All those tubes I collected could be sold and I could buy other gear.


----------



## Galapac

skhan007 said:


> Once you guys have found your optimal tubes, do you keep all the other ones you’ve collected? Now that I’m in club 5998, I’m not sure I’ll go back to anything else! All those tubes I collected could be sold and I could buy other gear.


If you have some desirable ones they keep going up in value every day as there is a finite number of them so you could consider it an investment, or you could pay it forward and give another member a good deal. Anyway it’s a winning proposition.


----------



## DenverW

skhan007 said:


> Once you guys have found your optimal tubes, do you keep all the other ones you’ve collected? Now that I’m in club 5998, I’m not sure I’ll go back to anything else! All those tubes I collected could be sold and I could buy other gear.


Sometimes it’s about variety and synergy.  You may get a great input tube that pairs well with your bendix in the future, or miss the thicker sound.  That being said, I usually keep some of my favorites and sell the rest.  

I’ve kept 7 or 8 of the best 12au7 tunes and sold many of my average 6sn7.  Since everyone knows that 12au7 are superior and all that.


----------



## skhan007

Just scored a matched pair of NOS 5998 locally, which is great. I now feel "fully stocked" having a small stash of 5998's. If a good price comes along on a 421a, I'd be curious to hear one. I believe Tung Sol and Chatham are the same company, so these should sound identical to my '59 Chatham. They look structurally identical.


----------



## GreenNeedle (Feb 19, 2022)

raindownthunda said:


> I didn’t use a magnifying glass and didn’t have any issues, but some might find it useful. I also bought a “helping hands” station which I found to be somewhat cumbersome and mostly just soldered directly on the solder mat.



I have some 1x 2x and 4x reading glasses that I use for all sorts of things like soldering, tinkering with watch movements.............erm, reading the teeny tiny print on food packets I used to be able to read. lol.  Cheap and cheerful but mega useful for magnifying things.


----------



## DenverW

skhan007 said:


> Just scored a matched pair of NOS 5998 locally, which is great. I now feel "fully stocked" having a small stash of 5998's. If a good price comes along on a 421a, I'd be curious to hear one. I believe Tung Sol and Chatham are the same company, so these should sound identical to my '59 Chatham. They look structurally identical.


Here are a couple pics of the 421a I have here at the office:


----------



## skhan007

DenverW said:


> Here are a couple pics of the 421a I have here at the office:


Beautiful! How fast can you ship? 

In your opinion, can you tell me where a 5998 would score on a 0-10 scale and where you’d score the 421a? Trying to get a subjective ranking of the 421a.


----------



## DenverW

skhan007 said:


> Beautiful! How fast can you ship?
> 
> In your opinion, can you tell me where a 5998 would score on a 0-10 scale and where you’d score the 421a? Trying to get a subjective ranking of the 421a.


Ah!  You’re going to pin me down .  I would say if the 421a is my favorite tube and gets a 10 then the 5998 gets a 8.5 and the gec straight brown base 6as7g is a 9.  I haven’t heard the curved brown base gec 6as7g, but it is supposedly just as good if not better than the 421a, but costs a PRETTY penny.


----------



## DenverW

I will also say this:  if you have a crack, don’t buy a 421a.  If you plan on upgrading to the c2a one day, or a more expensive amp using 6080 equivalent that’s fine, but the crack sounds great with tubes that don’t cost $200, and the c2a stock sounds better than a crack with a 421a.


----------



## skhan007

DenverW said:


> I will also say this:  if you have a crack, don’t buy a 421a.  If you plan on upgrading to the c2a one day, or a more expensive amp using 6080 equivalent that’s fine, but the crack sounds great with tubes that don’t cost $200, and the c2a stock sounds better than a crack with a 421a.


Thanks, I appreciate the feedback! It’s exciting to explore tubes, but at this point the cost of the tubes that I’ve collected for exceed probably what I need. While I am quite curious about the 421A, I think you’re right, it makes sense just to perhaps stick with what I’ve got. Honestly, I’m quite happy with the 5998.


----------



## DenverW

skhan007 said:


> Thanks, I appreciate the feedback! It’s exciting to explore tubes, but at this point the cost of the tubes that I’ve collected for exceed probably what I need. While I am quite curious about the 421A, I think you’re right, it makes sense just to perhaps stick with what I’ve got. Honestly, I’m quite happy with the 5998.


You can also resell them.  The way I look at it, is if I resell a piece of gear for less than I got it, I'm just paying a fee to rent the gear for a while.


----------



## ColdsnapBry (Feb 11, 2022)

Just curious on what some BHC owners thoughts are. I'm having a service build my BHC and I'm wondering if I should have it built right out with a speedball. I have a ZMF Verite Open headphone and hoping to get a bit more of a warmer and fuller presentation with it on tubes. I heard the stock BHC is pretty warm and I might like that, but probably best to get the speedball installed?


----------



## DenverW

ColdsnapBry said:


> Just curious on what some BHC owners thoughts are. I'm having a service build my BHC and I'm wondering if I should have it built right out with a speedball. I have a ZMF Verite Open headphone and hoping to get a bit more of a warmer and fuller presentation with it on tubes. I heard the stock BHC is pretty warm and I might that, but probably best to get the speedball installed?


Honestly, my first suggestion is to NOT have a service build it, unless you are already comfortable with doing the builds and just don’t want to do this one.  It isn’t a hard build, and the knowledge gained about the components, build, and soldering is invaluable in the future in case you want to upgrade anything or there is a future problem.

That being said, do the stock crack first, then add speedball a couple weeks later.  It lets you understand the change in sound and determine which you prefer.  Also, if there is an issue, it is easier to identify if everything is done separately.


----------



## skhan007

ColdsnapBry said:


> Just curious on what some BHC owners thoughts are. I'm having a service build my BHC and I'm wondering if I should have it built right out with a speedball. I have a ZMF Verite Open headphone and hoping to get a bit more of a warmer and fuller presentation with it on tubes. I heard the stock BHC is pretty warm and I might like that, but probably best to get the speedball installed?


Agree with @DenverW . I’ll also add that the ZMF VO and crack is a phenomenal pairing.


----------



## barbz127

skhan007 said:


> Agree with @DenverW . I’ll also add that the ZMF VO and crack is a phenomenal pairing.


Would you know if it's as good with VC also?


----------



## raindownthunda

barbz127 said:


> Would you know if it's as good with VC also?


It‘s excellent with the VC


----------



## DeweyCH

Anyone have thoughts or experience using a solid state preamp feeding a Crack? I’m considering making the Crack my second “zone” for my Luxman TP-117 rather than feeding my DAC into it directly. This would be nice because the TP has a nice phono stage, remote control and can switch easily between sources and outputs (main zone is a R-117 SS receiver).


----------



## SHIMACM

Hello friends, I am a new owner of a Crack with Speedball in the area. 

Some valve bearings.


----------



## SHIMACM

I own a Darvoice 336se as well.

I've been noticing that the valve bearing in Crack is much less sensitive than in Darkvoice.

I'm even thinking about getting rid of some exotic valves I own.


----------



## CaptainFantastic

SHIMACM said:


> Hello friends, I am a new owner of a Crack with Speedball in the area.
> 
> Some valve bearings.



Very nice. What are you using there for power tubes?


----------



## SHIMACM

CaptainFantastic said:


> Very nice. What are you using there for power tubes?



A pair of GEC CV4079.

By many reports, sound very close to the GEC 6as7g.


----------



## carlman14

SHIMACM said:


> Hello friends, I am a new owner of a Crack with Speedball in the area.
> 
> Some valve bearings.



Congrats! Love the green on the transformer. What are the driver tubes in the first pic? Are they 6C5s?


----------



## smodtactical (Mar 13, 2022)

Just built my crack OTL (no speedball) and I am absolutely loving the sound with BS650, HD800S and ZMF Atticus. Even compared to my TU8600S that is heavily upgraded and has warm 300b and input tubes I think I prefer the crack that sounds bigger more immersive and 3D !

Are there any mods or other amps you guys did/moved to that prefer that euphonics and bloom but still improved the sound further? I do have speedball kit but I know lot of ppl said that it takes way the euphonics and warmth and makes it more neutral / ss sounding.


----------



## DenverW

smodtactical said:


> Just built my crack OTL (no speedball) and I am absolutely loving the sound with BS650, HD800S and ZMF Atticus. Even compared to my TU8600S that is heavily upgraded and has warm 300b and input tubes I think I prefer the crack that sounds bigger more immersive and 3D !
> 
> Are there any mods or other amps you guys did/moved to that prefer that euphonics and bloom but still improved the sound further? I do have speedball kit but I know lot of ppl said that it takes way the euphonics and warmth and makes it more neutral / ss sounding.


The speedball will tighten things up a bit and you'll lose a bit of the bloom for more detail and other benefits.  Upgrades that you can do if you want to trick out the crack but not install speedball would be replacing the 100uf caps with film caps or changing out the potentiometer with an upgrade such as an audio note or blue velvet.


----------



## smodtactical

DenverW said:


> The speedball will tighten things up a bit and you'll lose a bit of the bloom for more detail and other benefits.  Upgrades that you can do if you want to trick out the crack but not install speedball would be replacing the 100uf caps with film caps or changing out the potentiometer with an upgrade such as an audio note or blue velvet.



I think ill def change the pot eventually since id like something a bit more smooth feeling.

Will the cap upgrade or any other upgrades preserve the bloom but just bring more technicality?


----------



## cddc

smodtactical said:


> I think ill def change the pot eventually since id like something a bit more smooth feeling.
> 
> Will the cap upgrade or any other upgrades preserve the bloom but just bring more technicality?




Cap or pot change is only component swap, it's like some tuning thing (similarly swap fuse, wires, etc), they won't affect the amp from a technical perspective, in other words they will preserve the bloom that you like, so no worries.

Only upgrades like Speedball will change the amp technically, by supplying a constant current source which makes the tubes work in a more linear fashion. Or if you like you can change the tube heaters from AC to DC, which is also a technical change, so to speak.


----------



## smodtactical

cddc said:


> Cap or pot change is only component swap, it's like some tuning thing (similarly swap fuse, wires, etc), they won't affect the amp from a technical perspective, in other words they will preserve the bloom that you like, so no worries.
> 
> Only upgrades like Speedball will change the amp technically, by supplying a constant current source which makes the tubes work in a more linear fashion. Or if you like you can change the tube heaters from AC to DC, which is also a technical change, so to speak.



So cap changes won't impact the sound ? If they do in what way?


----------



## Toad_of_Toad_Hall (Mar 14, 2022)

smodtactical said:


> So cap changes won't impact the sound ? If they do in what way?



Yes, cap changes impact the sound, but suitable film capacitors can be very expensive indeed. If you do decide to try out some replacement caps, remember that the improvements they offer are marginal to most and inaudible to some. Spending a few bucks is fine.  However, IMO, instead of spending hundreds of dollars on caps (as some do) you're better off putting the money towards a different amp, another pair of headphones, or a nice weekend away.  If you have all the amps, headphones and holidays you need, I'm sure there are many charities out there who'd like to have a chat with you.

Edit: I hope I don't come across as preachy: I say all this as someone who has spent hundreds of dollars on capacitors in the power supply and output of the Crack. Wish I hadn't, but I had fun along the way.


----------



## DenverW

Toad_of_Toad_Hall said:


> Yes, cap changes impact the sound, but suitable film capacitors can be very expensive indeed. If you do decide to try out some replacement caps, remember that the improvements they offer are marginal to most and inaudible to some. Spending a few bucks is fine.  However, IMO, instead of spending hundreds of dollars on caps (as some do) you're better off putting the money towards a different amp, another pair of headphones, or a nice weekend away.  If you have all the amps, headphones and holidays you need, I'm sure there are many charities out there who'd like to have a chat with you.
> 
> Edit: I hope I don't come across as preachy: I say all this as someone who has spent hundreds of dollars on capacitors in the power supply and output of the Crack. Wish I hadn't, but I had fun along the way.


I love it!  I’ll mention that the memories of a nice weekend will fade over time, but a film cap will burn in and get better .


----------



## JamieMcC

Fwiw changes in both tube and cap sonic difference's are more noticeable if your running a good attenuator I prefer stepped myself. The stock pot is a cheap part and is known for its poor performance it's the first thing I would look to upgrade imho.


----------



## DenverW

There are decent pot upgrades for under $30 from parts connexion.


----------



## smodtactical

Toad_of_Toad_Hall said:


> Yes, cap changes impact the sound, but suitable film capacitors can be very expensive indeed. If you do decide to try out some replacement caps, remember that the improvements they offer are marginal to most and inaudible to some. Spending a few bucks is fine.  However, IMO, instead of spending hundreds of dollars on caps (as some do) you're better off putting the money towards a different amp, another pair of headphones, or a nice weekend away.  If you have all the amps, headphones and holidays you need, I'm sure there are many charities out there who'd like to have a chat with you.
> 
> Edit: I hope I don't come across as preachy: I say all this as someone who has spent hundreds of dollars on capacitors in the power supply and output of the Crack. Wish I hadn't, but I had fun along the way.


No I hear you and appreciate your advice. The Crack sounds so incredible that I actually don't want to even touch it lol.

The question I have is where do I go from here to maintain the romance and warmth and midrange seduction but improve on it? I can only think of DNA as being a potential 'upgrade' ? Maybe crackatoa ?


----------



## smodtactical

DenverW said:


> There are decent pot upgrades for under $30 from parts connexion.



Ya I am thinking about either the alps rk27 or Audio note.


----------



## smodtactical

Listening to BS650 + Crack OTL and its hypnotizing. On Crack OTL I feel like i can hear all these details i didnt hear before. Subtle nuances. It is weird I don't understand why.  Is it because the song is relaxed and allowing me to notice things that are more subtle since foreground detail is not jumping out into my face ?

I love this amp so much I can't describe it even. And its surrounded by amps that cost thousands more but I think i prefer Crack over everything i have.


----------



## GPJ7 (Nov 30, 2022)

..................


----------



## pravous

GPJ7 said:


> This Audio Note pot is a good one. I use it in a S.E.X amp and it is very smooth, has more turning resistance than the Alps that is in my Crack/SB. It is balanced very nicely all the way through. I like it much better than the Alps although both are very good performers.
> 
> https://www.partsconnexion.com/ANVPOT-81914.html


I used the audio note pot on my Bottlehead crack build as well.  Very happy with it.  I love that chicken head volume knob and plate.  If you don't mind me asking where did you find the dial plate?


----------



## smodtactical

Anyone put the tkd pot in ? I have it in my elekit and its really nice. But I think im gonna try the audio note one.

https://www.partsconnexion.com/TKD-64187.html


----------



## GPJ7 (Mar 15, 2022)

pravous said:


> I used the audio note pot on my Bottlehead crack build as well.  Very happy with it.  I love that chicken head volume knob and plate.  If you don't mind me asking where did you find the dial plate?



Thanks!

https://www.amazon.com/gp/product/B07SGY3LZF/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

The knob that comes with it is decent too.


----------



## DenverW

I’ve used both audio note and blue velvet pots and slightly preferred the audio note, but it really didn’t matter. 

Also, I have a crackatwoa.  It was a much harder build, but it is an excellent amp and pairs very naturally with the same headphones the crack does.  If you want to jump right into a direct sonic upgrade this is it.


----------



## GPJ7 (Mar 16, 2022)

If I was buying new, I would definitely go straight to the Crackatwoa. I built my Crack/SB in 2014. Paid $325 back then and did about$100 in upgrades. I am really happy with the performance. So much so that a Crackatwoa will never make financial sense. I did build an S.3.X. recently and it is excellent. More refined than Crack/SB and a better overall amp IMO, but I enjoy both equally. And, I've enjoyed them more than any SS headphone amp I've used.


----------



## GreenNeedle (Mar 17, 2022)

smodtactical said:


> Anyone put the tkd pot in ? I have it in my elekit and its really nice. But I think im gonna try the audio note one.
> 
> https://www.partsconnexion.com/TKD-64187.html


Yeah very very smooth.  It glides and (seems to me) to be equalized L&R all the way up to FKN LOUD. lol
I ground the pin guide, next to the pole, off mine as it is in a different direction to the stock plate and tightened it on as hard as possible plus I had to take the pole down about half way to get my knob sitting a paper width off the plate surface.


----------



## smodtactical

I compared my Crack OTL to my ARC Ref5se into pass x350.8 and although the stack might be slightly more transparent and detailed I prefer the crack OTL. It has a richer smoother tone, full more seductive midrange and nearly matches the air and imaging of the FAR MORE expensive stack. I am utterly blown away by Crack OTL (this is with BS650).


----------



## smodtactical

Some of my comments from our discord:

its so incredibly seductive
the emotion in the sound is overwhelming
it connects me to the music in a different way
and i honestly dont find it muddly or lacking of clarity
i simply hear it as extremely pure and natural
arc/pass might have a hair more micro and a bit more transparency
but it loses some of that beautiful tone and full mid range
they def named this amp right
its addictive


----------



## DenverW

smodtactical said:


> Some of my comments from our discord:
> 
> its so incredibly seductive
> the emotion in the sound is overwhelming
> ...


You nailed it with ‘tone.’  I’ve learned about myself that however much I think I desire transparency, tone means more to me.  I gave up my 007 for my auteur, for example.

And what discord?  Is there a headfi discord?


----------



## smodtactical

DenverW said:


> You nailed it with ‘tone.’  I’ve learned about myself that however much I think I desire transparency, tone means more to me.  I gave up my 007 for my auteur, for example.
> 
> And what discord?  Is there a headfi discord?



No our audio discord, sonic visions. Its in my signature feel free to stop by.


----------



## smodtactical (Mar 20, 2022)

Ok so as you guys know I am loving the non-speedball OTL Crack amp  (with BS650, HD800S and ZMF Atticus). I am thinking of where to go from here. I know some may say 'if you love it stop'. But I feel there is yet more out there to explore... and since this is my first taste of a warm, spacious holographic sound I want to sample more. This is my thought process.

Cayin HA 300 -> Seems to be plagued with issues although proponents of it seem to really like it (@jambaj0e liked it even more than DNA stellaris for its warm euphonic sound).

A+S Kenzie / mogwai -> Again seems to have lot of noise issues from my reading and ive read some impressions that mids are actually fairly flat / recessed? But this seems to be a common rec for a euphonic tube sound.

Crackatoa -> Seems like a logical next step, still OTL, speedball integrated so maybe not as euphonic? Also will the step up in sonics be worth it over crack otl?

 DNA Stratus / stellaris -> Seems to be universally praised as a warm but detailed amp... my concern is that it may not be warm enough for me (at least 3 people ive talked to called stellaris neutral and ha300 and wa33 elite warmer and more euphonic).

Custom? Aric audio, radu tarta etc -> Fairly pricey and risky (poor resell most likely) if it doesn't turn out well.

I know at some point I have to just get things and try them (for context again the amps I've heard, audio gd he9, elekit tu8600 with mullard and WE clone tubes, ARC ref5se + pass x350.8 and before all that HDV820 and burson conductor SL so I have some level of minimal experience). But it would be nice if there was a clear path just based on recommendations for a warm euphonic but good quality amp. Seems its going to be very hard to find.


----------



## Galapac

My next step up from the BHC was the Elekit TU-8200 DX from diyaudio. Was a fun SET kit and the tolerances were spot on in the build. Japanese parts and very high quality.
It is my favorite amp now and possibly my end game.


----------



## smodtactical

Galapac said:


> My next step up from the BHC was the Elekit TU-8200 DX from diyaudio. Was a fun SET kit and the tolerances were spot on in the build. Japanese parts and very high quality.
> It is my favorite amp now and possibly my end game.



So I have arguably a step above that in the TU8600 prettty much with full upgrades and I prefer the crack otl. That is what makes things tough.


----------



## skhan007

smodtactical said:


> So I have arguably a step above that in the TU8600 prettty much with full upgrades and I prefer the crack otl. That is what makes things tough.


That’s great that you’re so happy with your BHC. I have not yet done the cap upgrade, but the absolute best/biggest improvement I’ve personally experienced is the 5998 tube. I can’t say enough about the huge improvement in clarity, separation, and overall frequency.


----------



## smodtactical

I'll look into that. I am also thinking about getting a crackatwoa and making that my 'modding' platform so to speak.


----------



## JazzVinyl

skhan007 said:


> That’s great that you’re so happy with your BHC. I have not yet done the cap upgrade, but the absolute best/biggest improvement I’ve personally experienced is the 5998 tube. I can’t say enough about the huge improvement in clarity, separation, and overall frequency.



Does your crack have the Speedball?


----------



## skhan007

JazzVinyl said:


> Does your crack have the Speedball?


Yes, speedball, RCA clear top 12au7 and Chatham 5998 currently.


----------



## SlothRock

Hey all! New to tube amps and looking at the crack/bottlehead OTL as a potential starting point. It's kinda hard to gauge, but how compact is this amp? I'd be putting it on my computer desk which doesn't have tons and tons of space left over for me to place it. Some of the pictures it looks quite compact and others not so much so its a bit hard to gauge.


----------



## DenverW

SlothRock said:


> Hey all! New to tube amps and looking at the crack/bottlehead OTL as a potential starting point. It's kinda hard to gauge, but how compact is this amp? I'd be putting it on my computer desk which doesn't have tons and tons of space left over for me to place it. Some of the pictures it looks quite compact and others not so much so its a bit hard to gauge.


I believe 12x10x6?  On a desk it’s fine, just make sure you have some vertical room for tubes and cable connections.  Crackatwoa and mainline are both larger and more square than rectangle.


----------



## Galapac

SlothRock said:


> Hey all! New to tube amps and looking at the crack/bottlehead OTL as a potential starting point. It's kinda hard to gauge, but how compact is this amp? I'd be putting it on my computer desk which doesn't have tons and tons of space left over for me to place it. Some of the pictures it looks quite compact and others not so much so its a bit hard to gauge.


Are you going to build one? I recommend it and it is highly rewarding and if something goes wrong you will know better how to fix it.
There is a great BHC forum on the site for help as well.

I saw you mention that you have the ZMF VC Camphor Burl and they will work well with that amp.
Trust me.


----------



## skhan007

Galapac said:


> Are you going to build one? I recommend it and it is highly rewarding and if something goes wrong you will know better how to fix it.
> There is a great BHC forum on the site for help as well.
> 
> I saw you mention that you have the ZMF VC Camphor Burl and they will work well with that amp.
> Trust me.


I will also confirm that my ZMF cans (Teak Auteur and Camphor Burl Verite Open) are an absolute PERFECT match for the BHC Speedy. Listening to King Crimson "Red" this morning as I type this. With the current tube complement, the sound is so brilliant and lively, like I'm in the room with the band! Cheers to all...


----------



## L0rdGwyn

Just a random thought - a fun project could be to buy two Cracks, parallel the sections of both the 12AU7 and 6AS7G, and run them as headphone monoblocks.  Would cut the output impedance in half, I bet it would sound pretty good!  Wonder if anyone has done it.


----------



## Galapac (Mar 26, 2022)

L0rdGwyn said:


> Just a random thought - a fun project could be to buy two Cracks, parallel the sections of both the 12AU7 and 6AS7G, and run them as headphone monoblocks.  Would cut the output impedance in half, I bet it would sound pretty good!  Wonder if anyone has done it.


That kind of reminds me of how the 339i was built, as a parallel system with separate power supplies for each channel.
That would be a cool undertaking to see a combined Crack, maybe call it the “Split Crack”. 😂


----------



## L0rdGwyn

Galapac said:


> That kind of reminds me of how the 339i was built, as a parallel system with separate power supplies for each channel.



Oh yeah I guess that's pretty much what they did  except the Crack + Speedball uses active loading rather than resistive, which is a huge benefit.  I suspect it would be superior to a 339i.


----------



## steve468

smodtactical said:


> Ok so as you guys know I am loving the non-speedball OTL Crack amp  (with BS650, HD800S and ZMF Atticus). I am thinking of where to go from here. I know some may say 'if you love it stop'. But I feel there is yet more out there to explore... and since this is my first taste of a warm, spacious holographic sound I want to sample more. This is my thought process.
> 
> Cayin HA 300 -> Seems to be plagued with issues although proponents of it seem to really like it (@jambaj0e liked it even more than DNA stellaris for its warm euphonic sound).
> 
> ...


Sorry I'm a bit behind with this reply, but I have a few of the options you're considering in the house right now, so maybe I can provide some insight. I have a Cayin-HA300, and a Crackatwoa (after building a Crack w/Speedball, now gone awhile ago), as well as a ZMF Pendant on hand, with HD800S and Atticus. 

To my ears, if you want lush, warm, euphonic, etc., the best option at least of those 3 is the HA-300. It does a great job of being detailed and natural without being too harsh. 

The Crackatwoa is definitely a big step up from the Crack, but as you guessed, it goes further away from that warm euphonic sound - I would say it's actually on the brighter side, with an incredibly open, wide sound. 

The Pendant is one you should consider with the Atticus - the sound is very fast and punchy compared to the others, which pairs great with the smoothness of the Atticus. Tubes are still fairly cheap and plentiful, and can be used to make it just about as warm as the Cayin, though maybe not as detailed and smooth. I'm sure the Kenzie is also great, I'd love to get ears on one one day.

And if cost is an issue, obviously the Cayin is quite a bit more expensive while not necessarily being better, just different.


----------



## Galapac

L0rdGwyn said:


> Oh yeah I guess that's pretty much what they did  except the Crack + Speedball uses active loading rather than resistive, which is a huge benefit.  I suspect it would be superior to a 339i.


Would you share the power supply between the two or theoretically build 2 of them with a pass-thru between both of them?
This would take a bit of thought to pull off and I’m really surprised no one has done this or maybe they have.
I will have to research this and Bottlehead gives you a discount too if you buy 2 or more at a time.


----------



## jonathan c

Galapac said:


> That kind of reminds me of how the 339i was built, as a parallel system with separate power supplies for each channel.
> That would be a cool undertaking to see a combined Crack, maybe call it the “Split Crack”. 😂


The system would be the Crack…the two amps would be the Cheeks…😂


----------



## L0rdGwyn

Galapac said:


> Would you share the power supply between the two or theoretically build 2 of them with a pass-thru between both of them?
> This would take a bit of thought to pull off and I’m really surprised no one has done this or maybe they have.
> I will have to research this and Bottlehead gives you a discount too if you buy 2 or more at a time.



No it would be two completely different Cracks with separate power cords and IEC inlets, unless you wanted to get a single top plate made that could house both sections and run one IEC inlet to both power transformer primaries.  I can ask Paul about it, I'd be shocked if he hadn't tried it himself or advised someone on doing it.


----------



## DenverW

L0rdGwyn said:


> Just a random thought - a fun project could be to buy two Cracks, parallel the sections of both the 12AU7 and 6AS7G, and run them as headphone monoblocks.  Would cut the output impedance in half, I bet it would sound pretty good!  Wonder if anyone has done it.


When you volunteer your friends, you volunteer yourself!

Woot!  I’m anxious to hear how this project goes!


----------



## jonathan c

DenverW said:


> When you volunteer your friends, you volunteer yourself!


The corollary:  “it’s easy to be generous with others’ time”…😉😏…


----------



## L0rdGwyn

I'd love to work on it, but I don't have time!  Got a queue of projects to work on already.  Maybe some time in the next few years of things slow down.


----------



## smodtactical

steve468 said:


> Sorry I'm a bit behind with this reply, but I have a few of the options you're considering in the house right now, so maybe I can provide some insight. I have a Cayin-HA300, and a Crackatwoa (after building a Crack w/Speedball, now gone awhile ago), as well as a ZMF Pendant on hand, with HD800S and Atticus.
> 
> To my ears, if you want lush, warm, euphonic, etc., the best option at least of those 3 is the HA-300. It does a great job of being detailed and natural without being too harsh.
> 
> ...



 Really helpful thank you so much.  At the end you said Cayin is more expensive but not better than what? Crack OTL ?

Ya I wish you had Kenzie OG or Ovation. Tylers eclectic did a recent video on the kenzie 2 (I think og) and found that its not as euphonic as OTL crack but its still quite warm.

Also @Maxx134  did a mod to ha300 involving i think adding or replacing 1 cap and apparently makes a huge difference in technical performance while maintaining tone.


----------



## steve468

smodtactical said:


> Really helpful thank you so much.  At the end you said Cayin is more expensive but not better than what? Crack OTL ?
> 
> Ya I wish you had Kenzie OG or Ovation. Tylers eclectic did a recent video on the kenzie 2 (I think og) and found that its not as euphonic as OTL crack but its still quite warm.
> 
> Also @Maxx134  did a mod to ha300 involving i think adding or replacing 1 cap and apparently makes a huge difference in technical performance while maintaining tone.


I just meant the Cayin is more of a different flavour (a warm, rich, detailed and yummy flavour mind you) compared to the Crackatwoa and the Pendant. They all have their strengths and weaknesses.

I'll try and track down that Kenzie video, thanks. As if I need another amp on my radar...


----------



## Maxx134 (Mar 31, 2022)

smodtactical said:


> Also @Maxx134 did a mod to ha300 involving i think adding or replacing 1 cap and apparently makes a huge difference in technical performance while maintaining tone


To clarify,  it was one "area",  not one cap. It was fhe coupling cap stage (2caps in single ended amps like Cayin).

The coupling cap stage is the most important and most universal spot to upgrade on every tube amp.
 Absolutely every manufacturer uses "lower-tier" cost savings cap here, for practicality and profit margins.
It is not any CCS stage (speedball name, ha) or PSU stage.

Also, adding a CCC (constant current source) circuit to your tube does not increase resolution.  That is a fallacy.  It mainly cleansup tube sound, by eliminating thse chosen bias curve of a resistor bias design, with instead some "optimal" neutral bias curve.

It changes the operation of the bias curve. So say goodbye to your tube sounds with a "speedball" circuit. Nothing is "speeded up" lol. Just a reduction of harmonics.
Harmonics is not "bad". It is in all sounds and what differentiates and personalize sounds.

Transparency and resolve are always present,  but the there are always one or two "bottleneck" (pun intended) areas, and they are always the "coupling " stage.
Either coupling between the amp stages (driver &output), OR...
Coupling between the output stage (transformer or capacitor output).

Designer's do not like to give out their secrets, but as builders we need to know and not just build a kit because it's supposed to sound better. Learn to design.

It is up to the consumer to choose wether to upgrade their amp to a  higher resolve level,  if they choose. Maybe you like the sound or don't have headphones that would take advantage of that "higher resolve" .
To me, after a long journey into this, I come full circle to realize that "musicality" should be of top concern. That is the key for musical enjoyment.

" Nirvana", is to have both the "resolve" and the "musicality/euphorics" at same league.

The excuses today of gear being described as "unapologetic" or harsh at a higher resolve is why synergy with gear is more important.  Get a good source and mate with your euphoric tube amp and you eliminate much spending.
Then just upgrade your existing chosen amp. Choose wisely..😄




steve468 said:


> I just meant the Cayin is more of a different flavour (a warm, rich, detailed and yummy flavour mind you) compared to the Crackatwoa and the Pendant. They all have their strengths and weaknesses


Totally agree here.


----------



## smodtactical

Listening to arc + pass / atc scm7. And its sounding really good. The Tung sol I put in the ref5se is helping but.... when I go to HD650 (black silk) + Crack OTL.... :O.... Its over. The smoothness, richness,  depth... you just sink into the music and  really relax. Its like the singers voice is just caressing your soul! :O

Lot of people overlook Crack OG (without speedball)... its insane  magic. This is one of the darkest head chains you can get but its still remains enthralling and detailed.


----------



## bagwell359

smodtactical said:


> Listening to arc + pass / atc scm7. And its sounding really good. The Tung sol I put in the ref5se is helping but.... when I go to HD650 (black silk) + Crack OTL.... :O.... Its over. The smoothness, richness,  depth... you just sink into the music and  really relax. Its like the singers voice is just caressing your soul! :O
> 
> Lot of people overlook Crack OG (without speedball)... its insane  magic. This is one of the darkest head chains you can get but its still remains enthralling and detailed.


That's true.  I have a bias towards tube amps that are more contiguous from top to bottom - like SS amps.  In OG form the bass is more tube like.  With the Speedball and upgraded output film caps, bypass caps, volume pot, cree diodes, power cable, etc... The bass and mids are not one but notably better and it doesn't dominate my attention as the stock does.


----------



## smodtactical

I got a Crack with speedball in so I can directly A-B, my notes:

So far
OG wins
speedball is more clear and crisper
a bit more detailed
but it loses some of the midrange magic and the emotion
and the texture in the singers voice
OG is smoother, more liquid... i think more bassy
speedball reminds me of elekit a bit
ya OG wins hands down... it sounds bigger, more 3d, more holographic... its amazing
the way the mids come forward in such an incredible way... like the singer steps forward out of the music to sing to you personally... its hard to describe
to be fair not the same tubes in each amp so i will try to swap tubes and compare further


----------



## smodtactical

bagwell359 said:


> That's true.  I have a bias towards tube amps that are more contiguous from top to bottom - like SS amps.  In OG form the bass is more tube like.  With the Speedball and upgraded output film caps, bypass caps, volume pot, cree diodes, power cable, etc... The bass and mids are not one but notably better and it doesn't dominate my attention as the stock does.



I respect that. I think I am looking for a different sound. I think I love rich, 3d, tubey, euphonic sound. SS is good or ss like tube sounds but I greatly prefer the former.

I guess I am weird


----------



## Galapac

bagwell359 said:


> That's true.  I have a bias towards tube amps that are more contiguous from top to bottom - like SS amps.  In OG form the bass is more tube like.  With the Speedball and upgraded output film caps, bypass caps, volume pot, cree diodes, power cable, etc... The bass and mids are not one but notably better and it doesn't dominate my attention as the stock does.


That’s interesting because I prefer the speedball upgrade as it appeared quieter overall where there was the lack of music, at least to me.
I enjoyed both versions, and for me, the speedball edged out. 
I also own an Elekit TU-8200 and prefer that overall to all of my amps and is my workhorse amp but I did heavily modify it with all upgraded components including Lundahl transformers so there is that. 

My music genres do you listen to the most and what headphones do you primarily use with the OG BHC?
That may be a factor why you prefer the the original as your whole chain works for you best.


----------



## smodtactical (Apr 5, 2022)

maybe its also the tubes or something ?
i just did some more AB
when i go to OG Crack
its so 3d sounding
im surrounded by the music'
it pulls me into it
whereas speedball kind has me at a distance
and im watching it
OG is just more engaging
speedball is flatter sounding like elekit
honestly im not even sure speedball is more detailed... id say its 'crisper' maybe
but OG is more natural and has much better flow... the music just pours and spills around you


----------



## GreenNeedle

smodtactical said:


> maybe its also the tubes or something ?
> i just did some more AB
> when i go to OG Crack
> its so 3d sounding
> ...


This is pretty much where I am at and have been pondering reverting back to non speedball. i want(ed) to like it with Speedball; 1 because it cost money, 2 because "everyone" says it is a night and day improvement but I find I lost some of the magic.

however.  with all the upgrades I've done I'm not sure whether I can run it non speedball with the upgrades.  Can I use the 6SN7 in the 12AU7 spot without speedball?  I am guessing that the choke, diodes, film caps will work fine?


----------



## GPJ7

Instead of dismantling, why not just buy another Crack? That's exactly what I am doing. I see that you are in the UK. You could probably get your money back on a resale after a thorough tryout? Or just keep both like I will


----------



## dstarr3

Suppose I wanted to build a Crack with a brass plate instead of the usual one. Is there an easy place to get my hands on a brass plate with the proper cutouts, or would I have to commission/make one myself?


----------



## Galapac

dstarr3 said:


> Suppose I wanted to build a Crack with a brass plate instead of the usual one. Is there an easy place to get my hands on a brass plate with the proper cutouts, or would I have to commission/make one myself?


You could probably get one made and use the plate that comes with it as a template but one of the main functions of the plate is to use it to ground your components and brass is not a great conductor of electricity for grounding.
That is why you do not see the plates painted underneath.

While the plate that it comes with is aluminum you can see brass drops a third in conductivity In the chart below.
It may be better to go with copper and you would get a nice patina over time.
Something to consider.


Material IACS (International Annealed Copper Standard)RankingMetal% Conductivity*1Silver (Pure)105%2Copper100%3Gold (Pure)70%4Aluminum61%5Brass28%6Zinc27%7Nickel22%8Iron (Pure)17%9Tin15%10Phosphor Bronze15%11Steel (Stainless included)3-15%12Lead (Pure)7%13Nickel Aluminum Bronze7%


----------



## bagwell359

Galapac said:


> That’s interesting because I prefer the speedball upgrade as it appeared quieter overall where there was the lack of music, at least to me.
> I enjoyed both versions, and for me, the speedball edged out.
> I also own an Elekit TU-8200 and prefer that overall to all of my amps and is my workhorse amp but I did heavily modify it with all upgraded components including Lundahl transformers so there is that.
> 
> ...


That's not what I said.  I like the sb better, and along with the other mods it's superb for what I like.  Still want a 800 on it. 

I listen to a lot of stuff - Norah Jones, Krall, Cowboy Junkies, Dead Can Dance, Prokofiev, Copeland, Miles Davis, King Crimson, Joni Mitchell, Neil Young, Durutti Column, Felt, Agnes Obel, etc...


----------



## bagwell359

dstarr3 said:


> Suppose I wanted to build a Crack with a brass plate instead of the usual one. Is there an easy place to get my hands on a brass plate with the proper cutouts, or would I have to commission/make one myself?


Paint it.  I did.  It's back in this thread.


----------



## dstarr3

Galapac said:


> one of the main functions of the plate is to use it to ground your components


Oh, I didn't realize that. Then yup, I'll just paint it or something. Thanks for the heads up!


----------



## GPJ7 (Apr 6, 2022)

Galapac said:


> You could probably get one made and use the plate that comes with it as a template but one of the main functions of the plate is to use it to ground your components and brass is not a great conductor of electricity for grounding.
> That is why you do not see the plates painted underneath.
> 
> While the plate that it comes with is aluminum you can see brass drops a third in conductivity In the chart below.
> ...



There is a guy who just built a mainline using a carbon fiber plate. Pics at BH forum.

A thing to remember with the Crack is there are only 2 locations where grounding occurs on the plate.

1. Terminal 3 (considered the "audio" ground)
2. IEC Ground (plate bolt next to IEC socket)

This is to minimize noise in the amplifier.

The IEC plastic socket, plastic on/off switch, RCA's, transformer terminal strips, and headphone jack are all mounted with isolation. The transformer bell is held on with poorly conducting steel bolts. Ultimately, one of those bolts is connected to IEC ground.

The volume pot body is in contact with the plate but all six lugs are isolated from the plate locally at the pot. The volume pot body can be considered as part of the plate with nothing electrically connected to it from the pot internally. The black wire from 2 pot lugs is routed to Terminal 3 (audio ground).

Same goes for the octal socket clamp. It is in contact with the plate but the socket pins are isolated from it. It attaches to Terminal 8 which has nothing connected to it.

The 9 pin socket clamp is in contact with the plate and is bolted to Terminal 3 and therefore part of the audio ground.

So in reality, Terminal 3 ground ultimately travels to the IEC grounding point through the plate. I am going to think a brass plate is going to be OK as long as everything is wired correctly. However, I am not the amp designer and it's best to contact BH for expert advice.


----------



## Galapac

bagwell359 said:


> That's not what I said.  I like the sb better, and along with the other mods it's superb for what I like.  Still want a 800 on it.
> 
> I listen to a lot of stuff - Norah Jones, Krall, Cowboy Junkies, Dead Can Dance, Prokofiev, Copeland, Miles Davis, King Crimson, Joni Mitchell, Neil Young, Durutti Column, Felt, Agnes Obel, etc...


Sorry @bagwell359, I quoted the wrong post, I meant to reply to  @smodtactical in my reply.
Must have been confusing.


----------



## Maxx134 (Apr 7, 2022)

bagwell359 said:


> With the Speedball and upgraded output film caps, bypass caps, volume pot, cree diodes, power cable, etc... The bass and mids are not one but notably better and it doesn't dominate my attention as the stock does.


There is a reason for this I will try to explain.




smodtactical said:


> I got a Crack with speedball in so I can directly A-B, my notes:
> 
> So far
> OG wins
> ...





smodtactical said:


> OG is just more engaging
> speedball is flatter sounding like elekit
> honestly im not even sure speedball is more detailed... id say its 'crisper' maybe
> but OG is more natural and has much better flow... the music just pours and spills around you..... "Lot of people overlook Crack OG (without speedball)... its insane magic. This is one of the darkest head chains you can get but its still remains enthralling and detailed"...




I  would like to clarify what is going on here, with the speedball implementation.
Traditionally,  this is called a "CCS" circuit. "Constant Current Source"
Look it up. Yet, from a designer's point of view, the end main result will cause less harmonics,  and so "clean up" the sound.
This equals _less tube sound_..a less thick or what amouts to less "euphoric" sound.
there are also other ways to have less tube (harmonics) sound.  Elimination of a cathode cap is another.
The main strength of tube holography stays regardless of how "clean" it will sound.

So choosing option of "speedball", should really be an option of how much _color_, or _richness_ in sound  that you prefer...
From a designer's perspective,  it should be viewed as a signature choice, rather than an "improvement".
I would say that the crack as an amp is as worthy as any amp to keep regardless of other expensive amps, if you prefer it's signature. Dont think just by buying a more expensive amp, you will be any more happier, if you already prefer the crack..

Yet _resolution_ is another matter. If you want higher resolve, then you just have to focus on the most prominent places for sound upgrade. All amps can benefit similarly from upgrades...
  So were? the coupling cap, and output cap areas are main areas that what you wanna upgrade for higher resolve.
Resolution is different from noise level, or added harmonics. There is a vague misconception that fixing all other things in an amp, will bring you higher resolve.  It may change and add performance to the resolve, but it basically that's not raising it.
For instance,  we can lower noise floor, and lessen harmonics to give a "cleaner" sound, but that's not increasing Resolution.  We can add more dynamics with larger caps,  but that's not increasing Resolution.
Those are separate added aspects.

So basically,  if you prefer the stock non-speedball sound, then you would like thicker amps.
Beware the illusion of going up the "price" ladder with other amps would be any better.
You should try and listen to them first, because many top amps have even more bloom and thicker or euphoric sound.

As most sound observations are "subjective" my comments are only my opinion, and should be put in perspective, as your ear and experience is what matters in the end.  If there's anything I would want you to know, is that you should not second guess your observations for others. Believe your ears 👍 
🙂


----------



## JNKM

Maxx134 said:


> There is a reason for this I will try to explain.
> 
> 
> 
> ...


Really appreciate accessible explanations like this — thanks! What are some examples of higher-tier amps that are even more thick and bloomy?


----------



## L0rdGwyn (Apr 7, 2022)

This "thick" sound that is being heard without the Speedball upgrade is the sound of second harmonic distortion.  Going from non-Speedball to Speedball changes the loading of both the 12AU7 input and 6AS7G output from a resistive load to a CCS load.

Functionally what this does is "flatten" the load line of the tubes as viewed on their characteristic curves.  The end result of that is minimization of second harmonic distortion as well as increase PSRR (power supply rejection ratio).  The increased PSRR means less of the power supply noise reaches the tube gain stage.

So if you like the sound of stock, that is the sound of second harmonic distortion.


----------



## bagwell359

Maxx134 said:


> There is a reason for this I will try to explain.
> 
> 
> 
> ...


Interesting.  I agree harmonics are manipulated for popularity/sales.  Music reproduction with none is like a desert.  Too much and it's like carmel on everything.  I like hybrid tubed electronics and Nelson Pass Class A amps - in the middle.

I think it's "euphonic" not "euphoric" BTW.


----------



## Asterisk3095 (Apr 12, 2022)

Hello,  I am interested in getting the Bottlehead Crack as my first ever tube amp, and my foray into soldering electronics. However I have one question I can't seem to find an answer for. Whenever I see anything about the Crack, people say to get the Speedball upgrade because it makes noticeable improvements to the amp. However, I have not seen any answer to what those improvements are, and what the speedball upgrade actually does. If anybody here can elaborate on this, that'd be great!


----------



## CaptainFantastic

Asterisk3095 said:


> Hello,  I am interested in getting the Bottlehead Crack as my first ever tube amp, and my foray into soldering electronics. However I have one question I can't seem to find an answer for. Whenever I see anything about the Crack, people say to get the Speedball upgrade because it makes noticeable improvements to the amp. However, I have not seen any answer to what those improvements are, and what the speedball upgrade actually does. If anybody here can elaborate on this, that'd be great!



Look precisely two posts above yours. Best succinct explanation I have seen.


----------



## Asterisk3095

CaptainFantastic said:


> Look precisely two posts above yours. Best succinct explanation I have seen.


ah... this is embarrassing. Anyways thanks for the help!


----------



## DenverW

Asterisk3095 said:


> ah... this is embarrassing. Anyways thanks for the help!


We’ve all been there!


----------



## GPJ7 (Apr 12, 2022)

I am actually buying a new Crack with no speedball to rediscover what I missed.. Admittedly, I immediately added speedball and output caps and recently did Crees and choke. All since initial build in 2014. End result is incredibly good but I want to find out what a bone stock (keep it unmodified out of box) Crack amp sounds like without all the changes. By the time I build it (hasn't shipped yet), I will have spent a great deal of time with the modified amp. So, it should be a really fun comparison. I think even better than doing it the other way. I will have the amps side by side for immediate comparison.

If I find it not to my liking I can always upgrade it cheap (or my brother gets a nice b-day present!)


----------



## raindownthunda

GPJ7 said:


> I am actually buying a new Crack with no speedball to rediscover what I missed.. Admittedly, I immediately added speedball and output caps and recently did Crees and choke. All since initial build in 2014. End result is incredibly good but I want to find out what a bone stock (keep it unmodified out of box) Crack amp sounds like without all the changes. By the time I build it (hasn't shipped yet), I will have spent a great deal of time with the modified amp. So, it should be a really fun comparison. I think even better than doing it the other way. I will have the amps side by side for immediate comparison.
> 
> If I find it not to my liking I can always upgrade it cheap (or my brother gets a nice b-day present!)


I’ve always wondered how difficult it would be to configure a switch to toggle between stock crack & speedball crack. Has this ever been done?


----------



## GPJ7 (Apr 12, 2022)

raindownthunda said:


> I’ve always wondered how difficult it would be to configure a switch to toggle between stock crack & speedball crack. Has this ever been done?



It could be done with enough thought and layout but the Crack chassis is small and it would probably require more than a few switches and additional wiring. And potential sound degradation. I personally think t would not be worth it.

The best option would be to build it stock like they say and wait. (I was too impatient and I think that is most everyone's problem). The other option is to buy another Crack. I personally think t's a good way to go. For one thing, I will have a lot of hours listening on the modded Crack so it should be plain as day to hear the differences. Especially with two completely different configurations side by side. No reliance on audio memory needed whatsoever. Instant A/B.

The other thing is a built Crack will resell for more money than paid most likely. Or do the full upgrades for about $300 and have a very clean sounding Crack/SB.

Or, If the goal is to have an upgraded eventually, just do a Crackatwoa to begin with and be done with it. The cost will be similar but the Crackatwoa will still be better. Myself, I just want the basic bare bones amp to hear the rawness of the tubes. And in my case, a C2A makes no financial sense.


----------



## smodtactical

Imo too many people jump to speedball. It loses a lot of the magic of og imo.


----------



## Galapac

smodtactical said:


> Imo too many people jump to speedball. It loses a lot of the magic of og imo.


One advantage of the Speedball upgrade is it allows you to use the E80CC tube which I find to be superior to the 12AU7 offerings.
I especially like the Philips version, and to me at least, I get more top end and expanded mids from the E80CC.

You can also take advantage of 6SN7 variants, which for people coming from the DarkVoice is an advantage as you do not need to buy more tubes.

It is also mentioned here in more detail from @DenverW :
https://www.head-fi.org/threads/crack-bottlehead-otl.476650/post-16286212


----------



## GPJ7 (Nov 28, 2022)

.........................


----------



## GPJ7 (Nov 28, 2022)

smodtactical said:


> Imo too many people jump to speedball. It loses a lot of the magic of og imo.



................................


----------



## GPJ7 (Nov 28, 2022)

.................................


----------



## KonanAtlante (Apr 16, 2022)

How many watts are the resistors? 1w, 3w?


GPJ7 said:


> The E80CC is indeed phenomenal with Crack/SB. I recently changed the transistors on the Speedball boards to run Matsushita 12BH7A's (Mullard tooled). Really excellent. Maybe as good as E80CC but I need to do more listening.
> 
> I have 470 ohm resistors installed permanently on the Speedball boards. And changed the transistors permamnently to the more robust ON MJE5731AG for use with 12BH7A.
> 
> ...


I have a valve amplifier very similar to the bottlehead, 6sa7g rca and 6sn7wgta sylvania brown, I opened it and I see that it has a speed ball (I didn't make it), I wanted to modify it so that it sounds better in the beyerdynamic dt880 600ohm, I notice it lacks power, mainly bass, the superlux 681 (modified, cable and casing) superlux hd330 150ohm (cable mod) works very well, with multitester it gives me the output at maximum volume voltage 3.w (varies according to the music and the moment in it is reproduced) with peaks of 5.5w in both channels and 10.00 kohm I leave some images in case you can give me some advice, what to modify















Speedball?





capacitor 220uf 160v siemens in the end towards the jack socket


----------



## GPJ7 (Apr 16, 2022)

KonanAtlante said:


> How many watts are the resistors? 1w, 3w?



They are 1/2 watt, +/- 1%

Interesting amp and very nice!  It looks like whoever built in knew what they were doing. I don't believe that is a Bottlehead Speedball board. I am nearly electrically illiterate and just provided the above information from what I learned at the BH forum. It isn't too complicated and there was enough good info there to try the mod. Sorry I can't help but I am sure there is a wizard here that might be able to help.


----------



## KonanAtlante

hikaru12 said:


> Really enjoying my Crack at first listen. This is what my Eikons needed to wake up, totally blows away the LP I had them on before. The mid detail is excellent and the bass is quite nice. Very easy but fun listen. I can't wait to get my Aeolus to pair with it. RCA Grey glass might be my next runner up for driver tube.


can you tell me where you bought the headphone stand?


----------



## hikaru12

KonanAtlante said:


> can you tell me where you bought the headphone stand?


Try Angry Goose on Etsy. It’s very pricey but it’s expert craftsmanship. It’s my last stand I still have mine.


----------



## bagwell359

Galapac said:


> One advantage of the Speedball upgrade is it allows you to use the E80CC tube which I find to be superior to the 12AU7 offerings.
> I especially like the Philips version, and to me at least, I get more top end and expanded mids from the E80CC.
> 
> You can also take advantage of 6SN7 variants, which for people coming from the DarkVoice is an advantage as you do not need to buy more tubes.
> ...


I use the E80CC myself and it smokes the 12AU7 variants.  My amp is quieter, has better bass, detail, the treble has lots of decay harmonics but seems to have less HD, and the images are better fleshed out and more 3D.  Outside of that...

I did however spend a lot of money and my cathode follower (6080 and 6AS7G) are meh.  I missed out on a mint 5998 about 18 months ago and the prices since are bizzare.


----------



## Asterisk3095 (Apr 23, 2022)

As someone new to tubes, how many hours does a tube typically have for its lifetime? Furthermore, are there any popular tubes that are still in production? It makes me worried that I might like a certain tube, but when it runs out of life there won't be any more I can get since they won't be in production.


----------



## bagwell359

GPJ7 said:


> Chatham 2399 with Telefunken E80CC about 5 mins ago .... good stuffs for sure.


Wow near twin to mine


----------



## bagwell359

Asterisk3095 said:


> As someone new to tubes, how many hours does a tube typically have for its lifetime? Furthermore, are there any popular tubes that are still in production? It makes me worried that I might like a certain tube, but when it runs out of life there won't be any more I can get since they won't be in production.


Most no longer made.  Life depends on design and quality of tube construction.


----------



## Asterisk3095

bagwell359 said:


> Most no longer made.  Life depends on design and quality of tube construction.


ah I see... well that's unfortunate. someday there won't be any more tubes....


----------



## bagwell359

KonanAtlante said:


> How many watts are the resistors? 1w, 3w?
> 
> I have a valve amplifier very similar to the bottlehead, 6sa7g rca and 6sn7wgta sylvania brown, I opened it and I see that it has a speed ball (I didn't make it), I wanted to modify it so that it sounds better in the beyerdynamic dt880 600ohm, I notice it lacks power, mainly bass, the superlux 681 (modified, cable and casing) superlux hd330 150ohm (cable mod) works very well, with multitester it gives me the output at maximum volume voltage 3.w (varies according to the music and the moment in it is reproduced) with peaks of 5.5w in both channels and 10.00 kohm I leave some images in case you can give me some advice, what to modify
> 
> ...


Resistors in coffins?  Do you test values?  Lots of naked wire.  I jacket every bare wire in Teflon.  Hate shorts except outside.  I do like bypassing caps.  That directional cap attached the 150 uf resistor would be tough to dussasemble.


----------



## bagwell359 (Apr 23, 2022)

Asterisk3095 said:


> ah I see... well that's unfortunate. someday there won't be any more tubes....


Nah somebody will sell you NOS tubes or make new tubes if your wallet can handle it.

I have 1 very rare very great tube should last about 10x less than its life span which at age 65 is all I will need


----------



## jonathan c

Asterisk3095 said:


> ah I see... well that's unfortunate. someday there won't be any more tubes....


There will be tubes at a price that meets the demand. Whether a particular buyer can ‘stomach’ that price, well…


----------



## KonanAtlante

bagwell359 said:


> Resistors in coffins?  Do you test values?  Lots of naked wire.  I jacket every bare wire in Teflon.  Hate shorts except outside.  I do like bypassing caps.  That directional cap attached the 150 uf resistor would be tough to dussasemble.


I only tested the stripped jack output without any headphone load
complete old image, the blue cable that is seen from the xlr input to the alps potentiometer and from the siemens capacitor to the jack output, I changed it to low impedance 22awg roxtone, with this I eliminated radio noise that it had despite the insulation it has and I won a 25% volume approx, I also removed a led light diode that it had indicating the power on, according to what I read, this diode consumed me between 23 to 53 mw, the led diode had a rectifier diode and a resistor, when I removed them together with the diode led sound got very dirty especially the broken bass, I don't know their values, I reconnected them without the led diode and the sound came back clean and noiseless


----------



## Asterisk3095

jonathan c said:


> There will be tubes at a price that meets the demand. Whether a particular buyer can ‘stomach’ that price, well…


well yeah that makes sense. not going to be spending hundreds on rare tubes (yet) so i should be fine in that regard


----------



## Galapac

Asterisk3095 said:


> ah I see... well that's unfortunate. someday there won't be any more tubes....


There will be tubes, especially those that are more popular, just not the old NOS desired ones that most favor for their superior designs and materials.
There are companies today that make new tubes in Russia, China, Slovakia, and a few boutique tube manufacturers in other countries that make real high end tubes like the 300B for $$$$.


----------



## bagwell359

KonanAtlante said:


> I only tested the stripped jack output without any headphone load
> complete old image, the blue cable that is seen from the xlr input to the alps potentiometer and from the siemens capacitor to the jack output, I changed it to low impedance 22awg roxtone, with this I eliminated radio noise that it had despite the insulation it has and I won a 25% volume approx, I also removed a led light diode that it had indicating the power on, according to what I read, this diode consumed me between 23 to 53 mw, the led diode had a rectifier diode and a resistor, when I removed them together with the diode led sound got very dirty especially the broken bass, I don't know their values, I reconnected them without the led diode and the sound came back clean and noiseless


That's quite nice.  Good job.


----------



## cddc

Asterisk3095 said:


> As someone new to tubes, how many hours does a tube typically have for its lifetime? Furthermore, are there any popular tubes that are still in production? It makes me worried that I might like a certain tube, but when it runs out of life there won't be any more I can get since they won't be in production.




Normally new or NOS tubes last 5k - 10k hours under normal load, but in Crack they are lightly loaded, so they will last even longer. So there is no need to worry about tube lifetime.

Furthermore, tubes used in Crack are easy to find and their supply is abundant...I mean really really abundant....


----------



## Asterisk3095

cddc said:


> Normally new or NOS tubes last 5k - 10k hours under normal load, but in Crack they are lightly loaded, so they will last even longer. So there is no need to worry about tube lifetime.
> 
> Furthermore, tubes used in Crack are easy to find and their supply is abundant...I mean really really abundant....


I see! Many thanks. Glad to know that tubes are still so plentiful. I guess I was worried because I heard people saying there is a shortage due to the ongoing war in Ukraine/Russia


----------



## cddc

Asterisk3095 said:


> I see! Many thanks. Glad to know that tubes are still so plentiful. I guess I was worried because I heard people saying there is a shortage due to the ongoing war in Ukraine/Russia



The war only impacts Russian new production tubes, but those new production tubes can hardly compete with NOS tubes. There are tons of NOS 6080/6AS7G/12AU7/6SN7 tubes out there, so no worries.


----------



## bagwell359

cddc said:


> Normally new or NOS tubes last 5k - 10k hours under normal load, but in Crack they are lightly loaded, so they will last even longer. So there is no need to worry about tube lifetime.
> 
> Furthermore, tubes used in Crack are easy to find and their supply is abundant...I mean really really abundant....


Unless one uses an alternate driver tube like the EC80CC.  Also finding a standout 6080 type is difficult.

Also nobody mentioned the plethora of bogus NOS tubes available - on x bay and other places.

Some of the newer tubes from Czech, Russia, and China are unlistenable vs the same types from pre 1970 Europe and the US 

Overall you can wend your way - just stick with the tubes you get with the BHC.  It's when you step into the depths that the churn can be quite wild.


----------



## bagwell359

GPJ7 said:


> Chatham 2399 with Telefunken E80CC about 5 mins ago .... good stuffs for sure.


Fairly similar


----------



## cddc

bagwell359 said:


> Unless one uses an alternate driver tube like the EC80CC.  Also finding a standout 6080 type is difficult.
> 
> Also nobody mentioned the plethora of bogus NOS tubes available - on x bay and other places.
> 
> ...




Yeah, I suppose it would be difficult to find a tube with the signature from her majesty the queen, but the 12AU7 and 6080 NOS tubes that come with the Crack kit can easily be found $5 apiece.


----------



## tomb

larcenasb said:


> <snip>
> 
> Thanks for the thorough explanation *tomb*! I understand better now. However, did you mean "Replace the _electrolytic_ cap with a _film cap_ and you may be increasing the power supply noise, not improving it."? Based on what you said about film caps having nothing to do with removing ripple and hum, that makes sense -- was that a mix-up?
> 
> So, my understanding now is that electrolytics are important in a PS to remove ripple and hum, so replacing them with film outright is not a great idea -- but bypassing with film is good as it can add a bit of smoothness to the de-rippled and de-hummed signal. Is that fair to say?


Sorry for the super-delayed response, but someone just liked my post that you are referencing.

So, in answer to the question, "Based on what you said about film caps having nothing to do with removing ripple and hum, that makes sense -- was that a mix-up?" - *there are more forms of noise from a power supply than just hum and ripple*.

I'll just go out on a limb here and make the sweeping statement: Most switching power supplies have little to no issue with ripple and hum.  Yet, most of them in a high-fidelity audio application sound like crap.  This is because switching power supplies introduce high-frequency trash into the power circuit.  A lot of this is beyond the audio limits of 20kHz, but harmonics cause the effects to be heard much lower down, well into the audio band.  Yes, there are some mfrs who claim their switching supplies are completely free of such noise, but that's a highly debatable topic, mostly because it almost always centers around whether you can _hear _it.  What one mfr may claim is inaudible may be clearly audible with our high-performance headphone setups. 

The specific reference I was making to film caps is that film caps in a power supply are there (one of many reasons) to reduce the high-frequency hash.  Even if the power supply is not a "switching" type, rectifiers themselves are switching all the time in the absolutely necessary conversion of AC to DC.  Sometimes film caps are placed directly across the leads of rectifiers to reduce this switching noise.  So, yes - I stated that if you replace a film cap with an electrolytic in a power supply you may increase the noise, not reduce it.  I didn't say that particular noise was hum and ripple.  An electrolytic capacitor is very useful for reducing hum and ripple, but high frequency noise?  No.


----------



## bagwell359 (Apr 24, 2022)

Dupe


----------



## bagwell359

cddc said:


> Yeah, I suppose it would be difficult to find a tube with the signature from her majesty the queen, but the 12AU7 and 6080 NOS tubes that come with the Crack kit can easily be found $5 apiece.


Read much?  Read my whole post.


----------



## larcenasb

tomb said:


> high-frequency trash


Haha, yeah, I understand now. Thanks so much  Even with the delay, I'm always happy to learn something new.  Cheers


----------



## GPJ7 (Nov 28, 2022)

bagwell359 said:


> Fairly similar



.............


----------



## Jonmakauu

Finally found the time to build my kit. The woodworking was the only part I had trouble since it is my first woodworking project. Overall, I really liked how easy to understand the instructions were!


----------



## Asterisk3095 (Apr 29, 2022)

What's the general consensus around here on the Bottlehead Power Cord Kit? Does it noticeably change the sound of the Crack, and is it really worth over $100 extra? If I were on a budget, would it be fine to just skip over it?


----------



## larcenasb (Apr 30, 2022)

It’s a good quality, durable cord. But changing the sound?… Some people will swear on it, but I’d challenge them to identify a fancier power cord over a generic one in a blind test. Remember, engineers will tell us time and again that there are miles and miles of generic wire bringing the electricity to our homes, so adding six feet of an “audio specialized” power cable dressed up in nice sleeving just doesn’t make sense in terms of making a difference.

To be fair, when Bottlehead first released the Bottlehead power cord, they explained it’s because they had a bunch of extra smaller gauge wire…so they decided to combine the wires for a thicker gauge and make it into power cord kits. They didn’t claim it would change a system’s sound, just that it’s a nice, durable cord and an easy kit for beginners.

In hi-fi there is so much pseudoscience only verified by sighted listening and wishful thinking. You can save lots of money by identifying what products make sense and can clearly change the sound of your system (headphones, ear pads, amp, tubes, DAC, etc.) and what products can’t outside of delusion (weights on top of electronics, cable risers, cryo treatment, power cords…).


----------



## Asterisk3095 (Apr 30, 2022)

larcenasb said:


> It’s a good quality, durable cord. But changing the sound?… Some people will swear on it, but I’d challenge them to identify a fancier power cord over a generic one in a blind test. Remember, engineers will tell us time and again that there are miles and miles of generic wire bringing the electricity to our homes, so adding six feet of an “audio specialized” power cable dressed up in nice sleeving just doesn’t make sense in terms of making a difference.
> 
> To be fair, when Bottlehead first released the Bottlehead power cord, they explained it’s because they had a bunch of extra smaller gauge wire…so they decided to combine the wires for a thicker gauge and make it into power cord kits. They didn’t claim it would change a system’s sound, just that it’s a nice and durable cord.
> 
> In hi-if there is so much pseudoscience only verified by sighted listening and wishful thinking. You can save lots of money by identifying what products make sense and can clearly change the sound of your system (headphones, ear pads, amp, tubes, DAC, etc.) and what products can’t outside of delusion (weights on top of electronics, cable risers, cryo treatment, power cords…).


Alright thanks, that's what I expected anyways since I never really believed cables could change sound anyways. Some of these people talking about cables seem really weird to me with how they act. Like they speak like their $1000+ cables change how a pair of headphones sounds completely and it confuses me because realistically, the cable should change the sound the least out of everything (if at all)


----------



## GPJ7 (Nov 28, 2022)

....................


----------



## GreenNeedle (May 3, 2022)

Asterisk3095 said:


> Alright thanks, that's what I expected anyways since I never really believed cables could change sound anyways. Some of these people talking about cables seem really weird to me with how they act. Like they speak like their $1000+ cables change how a pair of headphones sounds completely and it confuses me because realistically, the cable should change the sound the least out of everything (if at all)


They have a guide on the bottlehead site to build your own power cable.  I built one.  Mainly because I wanted a right angle cable and because I wanted to believe.  Does it sound better because of it?  Yes.........but probably because my mind wants it to sound better. lol.  I can't say hand on heart it makes any difference whether I think it does or not but I would like to think it does for my effort.

Biggest change I noticed with all the film caps, cree diodes, Silly money volume pot & other upgrades was the choke.  Cheap upgrade and was a very noticeable difference not subtle like the others.  Choke IMO is a no brainer upgrade.


----------



## bagwell359

Asterisk3095 said:


> Alright thanks, that's what I expected anyways since I never really believed cables could change sound anyways. Some of these people talking about cables seem really weird to me with how they act. Like they speak like their $1000+ cables change how a pair of headphones sounds completely and it confuses me because realistically, the cable should change the sound the least out of everything (if at all)


I was around ground zero when the cable wars started.  Bigger diam (lower guage).  I went along at first being a good audiophile - and the price was not much more.  But then it got crazy.  Pure silver, cryo.... I have some stuff from the 80's still.  The final straw was some 5 foot $5k cable - 3 of them at a dealers.  Loved the speakers - eventually bought them but my used cable didn't sound any different.

Now on the other hand I have blind tested balanced vs balanced (same) and SE vs SE interconnect (some different), speaker cable (no except exotics).  But the big thing here is HFM vs OFC cable - lots of differences - all in favor of replacements.

Don't let cachet, cost, appearance, ego get to you.  Do compare, hopefully blind.  Mind open.


----------



## GPJ7 (Nov 28, 2022)

........................


----------



## bagwell359

GPJ7 said:


> I've never went wrong with just an ordinary OFC cable. Inexpensive one's are perfectly fine IME. This includes speaker wire, interconnects, and headphone cables. I've had excellent results with all Mogami wire types and love the price.


I like Migami too.


----------



## bagwell359

BTW to get to the question - I had a nice Belden 12 GA power cord about 5' long. Chopped off the female end, mounted them too 100% copper lugs.  Heated up the shrink wrap to get a nice fit.  I didn't use the IEC plug, wired them straight in (no fuse).  Also no RCA connections (looks gross to me).  One sided RCA from pre amp to the connections underneath - using insulated cable.  Not reccomending - heck I've been building and moding since 1967.


----------



## MacMan31

I would love to get a Bottlehead Crack. But I don't have the space or tools to build it myself. I'd need someone to do that for me. Currently my tube amps are the Schiit Valhalla 2 and Lyr 3. I know the former is an OTL amp but according to Schiit "If you’re expecting syrupy, tubby, euphonically colored tube sound, you’re in for a shock. Valhalla 2 is exceptionally accurate, neutral, and resolving, without being strident or etched." They do not state the same for the Lyr 3 but I know it's a hybrid amp. So I suspect I'm not getting a genuine "tube sound" even though these amps do sound really good. It is really worth switching over to something like the BHC? My current headphones are HD6XX and ZMF Aeolus.


----------



## raindownthunda (May 23, 2022)

MacMan31 said:


> I would love to get a Bottlehead Crack. But I don't have the space or tools to build it myself. I'd need someone to do that for me. Currently my tube amps are the Schiit Valhalla 2 and Lyr 3. I know the former is an OTL amp but according to Schiit "If you’re expecting syrupy, tubby, euphonically colored tube sound, you’re in for a shock. Valhalla 2 is exceptionally accurate, neutral, and resolving, without being strident or etched." They do not state the same for the Lyr 3 but I know it's a hybrid amp. So I suspect I'm not getting a genuine "tube sound" even though these amps do sound really good. It is really worth switching over to something like the BHC? My current headphones are HD6XX and ZMF Aeolus.


Worth trying? Yes. Worth switching? Only your ears can decide. I personally love the big flavor the BHC brings to the my Aeolus and VC and have a blast tube rolling. They both sound great from my Jot 2, but the rich, full and enveloping sound from the BHC is addicting. Pretty sure that‘s how the Crack got it’s name 

As for obtaining one - I’d highly recommend considering building it yourself if at all possible. It’s a very rewarding project and the instructions are very good. Many people on here and the bottlehead forums would be happy to guide you if you got stuck. Not many tools are required besides a soldering iron, and the tools you would purchase are likely to come in handy for future diy or household work. As for workspace, a small table and cheap soldering mat would suffice. If you’re set on not building it yourself, watching the classifieds or posting a WTB is probably your best bet. There is a builder on Etsy who will do it for a fee: www.etsy.com/listing/546413394 IMO at that price point you may want to consider going with a higher end amp.


----------



## skhan007

MacMan31 said:


> I would love to get a Bottlehead Crack. But I don't have the space or tools to build it myself. I'd need someone to do that for me. Currently my tube amps are the Schiit Valhalla 2 and Lyr 3. I know the former is an OTL amp but according to Schiit "If you’re expecting syrupy, tubby, euphonically colored tube sound, you’re in for a shock. Valhalla 2 is exceptionally accurate, neutral, and resolving, without being strident or etched." They do not state the same for the Lyr 3 but I know it's a hybrid amp. So I suspect I'm not getting a genuine "tube sound" even though these amps do sound really good. It is really worth switching over to something like the BHC? My current headphones are HD6XX and ZMF Aeolus.


Well, I haven't heard the other tube amps you've mentioned, but my BHC is tubbiness maximus! I have gravitated toward the 5998 and RCA clear top 12au7, after some tube rolling. I bought mine pre-made by an expert BHC builder and then had the granite enclosure custom made. I also use ZMF cans and it's a PERFECT pairing (as would be your Senns). While I really like it a lot, I may stick with solid state and go that route. Undecided, but I might sell and fund a solid state amp I have my eye on. Here's mine...


----------



## jonathan c

skhan007 said:


> Well, I haven't heard the other tube amps you've mentioned, but my BHC is tubbiness maximus! I have gravitated toward the 5998 and RCA clear top 12au7, after some tube rolling. I bought mine pre-made by an expert BHC builder and then had the granite enclosure custom made. I also use ZMF cans and it's a PERFECT pairing (as would be your Senns). While I really like it a lot, I may stick with solid state and go that route. Undecided, but I might sell and fund a solid state amp I have my eye on. Here's mine...


That _is _a beautiful piece of gear! Did you have ‘speedball’ installed?


----------



## skhan007

jonathan c said:


> That _is _a beautiful piece of gear! Did you have ‘speedball’ installed?


Thank you! Yes, speedball equipped!!

I listened to it today for some time and it truly sounds wonderful. I may just keep it, although I tend to want to listen to solid state more often. Not sure what the Head-Fi protocol is, LOL! If something doesn't get used very often, do we just hold on to it, just to have it and use on occasion? In theory, I could sell it (and the lot of vintage NOS tubes I accumulated) and fund something else. First world problems, I know.


----------



## larcenasb

skhan007 said:


> Thank you! Yes, speedball equipped!!
> 
> I listened to it today for some time and it truly sounds wonderful. I may just keep it, although I tend to want to listen to solid state more often. Not sure what the Head-Fi protocol is, LOL! If something doesn't get used very often, do we just hold on to it, just to have it and use on occasion? In theory, I could sell it (and the lot of vintage NOS tubes I accumulated) and fund something else. First world problems, I know.


I don't listen to my Crack every day, but when I do...oof, it's what I call my "special reserve label" setup. So yeah, I use a solid-state (my trusty Drop O2) for daily use, and I use my Crack setup for transportive, rejuvenating listens. Whatever you decide to do, keep enjoying the music.


----------



## jonathan c

skhan007 said:


> Thank you! Yes, speedball equipped!!
> 
> I listened to it today for some time and it truly sounds wonderful. I may just keep it, although I tend to want to listen to solid state more often. Not sure what the Head-Fi protocol is, LOL! If something doesn't get used very often, do we just hold on to it, just to have it and use on occasion? In theory, I could sell it (and the lot of vintage NOS tubes I accumulated) and fund something else. First world problems, I know.


•  You should keep it. The RCAs are very good 12AU7s. If you have not, try the RFT ECC82s ‘foil getter’. Those are wondrous in their sound quality.
•  WC Fields audio advice: “if you feel like listening to solid-state, lie down ‘til the feeling goes away”…😏


----------



## MacMan31

skhan007 said:


> Well, I haven't heard the other tube amps you've mentioned, but my BHC is tubbiness maximus! I have gravitated toward the 5998 and RCA clear top 12au7, after some tube rolling. I bought mine pre-made by an expert BHC builder and then had the granite enclosure custom made. I also use ZMF cans and it's a PERFECT pairing (as would be your Senns). While I really like it a lot, I may stick with solid state and go that route. Undecided, but I might sell and fund a solid state amp I have my eye on. Here's mine...



That looks awesome. Though I'm more of a wood finish kind of guy. Are tubes fairly easy to find for the BHC?


----------



## bagwell359

jonathan c said:


> •  You should keep it. The RCAs are very good 12AU7s. If you have not, try the RFT ECC82s ‘foil getter’. Those are wondrous in their sound quality.
> •  WC Fields audio advice: “if you feel like listening to solid-state, lie down ‘til the feeling goes away”…😏


ECC82 yummy.


----------



## skhan007

MacMan31 said:


> That looks awesome. Though I'm more of a wood finish kind of guy. Are tubes fairly easy to find for the BHC?


Thanks- I found the NOS 12AU7 tubes easy to find, but the 6AS7G, 6080, and 5998 were very, very difficult for me to find. So much so, that I had to source a couple from the UK as I could not find any in the US for sale.


----------



## GPJ7 (Nov 28, 2022)

.......................


----------



## DenverW

GPJ7 said:


> I recently built another Crack but this time without Speedball. The stock amp is just fine the way it is but my intention with this one is to never have Speedball installed. I did do the Cree's, Choke, and some Panny caps (plus XLR jack and Audio Note pot). Result is spectacular with my brand new Romanian HD 600, TS 5998 and TS 6SN7GB. This is the first time I've ever had thoughts of dumping my Woo Audio WA2. I am extremely happy with the two Crack's I have.


I looked at those caps too .  Great lush sound front the stock crack.  Time for a nice potentiometer?


----------



## GPJ7 (Nov 28, 2022)

..................


----------



## DenverW

GPJ7 said:


> I couldn't find the 100uF so used the 110uF. Really happy with them! That's a good suggestion on pot. I've only had the Alps and the Audio Note. The Audio Note pot is very good. I was debating laddered stepped attenuation but wasn't sure of the lower stepped one's and don't want to spend $200 on a top end one. I replaced a pot in a Little Dot Mk3 with a stepped DACT and thought the audio did indeed improve. I will probably leave well enough alone for now and think more about it as I go.


I popped an audio note into the s.e.x. Amp and it worked very well, as did the blue velvet.  With both under $30 it was a nice little add on.


----------



## GPJ7 (Nov 28, 2022)

........................


----------



## GreenNeedle

GPJ7 said:


> I recently built another Crack but this time without Speedball. The stock amp is just fine the way it is; my intention with this one is to never have Speedball installed. I did do the Cree's, Choke, and some Panny caps (plus XLR jack and Audio Note pot). Result is spectacular with my brand new Romanian HD 600, TS 5998 and TS 6SN7GTB. This is the first time I've ever had thoughts of dumping my Woo Audio WA2. I am extremely happy with the two Crack's I have.


So the question is which do you prefer?  The speedball or non speedball?  And are you saying you are using the 6SN7 in the non speedball?


----------



## bagwell359

The non SB version with stock parts is really a tube amp.  Like a Dyna Mk 3 but quieter.  The SB version tricked out with many updated parts is more like a hybrid with more taut bass - with less syrupy more precise treble.  

I'll always reach for the second choice but understand why others would not.


----------



## GPJ7 (Nov 28, 2022)

..................................


----------



## GPJ7 (Nov 28, 2022)

...................................


----------



## MacMan31

bagwell359 said:


> The non SB version with stock parts is really a tube amp.  Like a Dyna Mk 3 but quieter.  The SB version tricked out with many updated parts is more like a hybrid with more taut bass - with less syrupy more precise treble.
> 
> I'll always reach for the second choice but understand why others would not.



By SB I assume you mean speed ball right? So the SB upgrade makes the BHC sound less "tubey"?


----------



## bagwell359

MacMan31 said:


> By SB I assume you mean speed ball right? So the SB upgrade makes the BHC sound less "tubey"?


IMO


----------



## larcenasb

bagwell359 said:


> IMO


I second that. The speedball adds dynamics and clarity--especially in the bass--but the midrange still has that magical tube realism.


----------



## MacMan31

I was looking at various posts on Reddit concerning the BHC. There seems to be a divide on the Speedball option. Some say it seems to remove some of the "tube sound" and are against the option. Others really like the upgrade. Would be nice if there was a switch on the amp to turn speedball on or off. Kind of like having a bass boost button.


----------



## bagwell359 (May 30, 2022)

MacMan31 said:


> I was looking at various posts on Reddit concerning the BHC. There seems to be a divide on the Speedball option. Some say it seems to remove some of the "tube sound" and are against the option. Others really like the upgrade. Would be nice if there was a switch on the amp to turn speedball on or off. Kind of like having a bass boost button.


The circuit is way to integrated in the amp for that.

I do like tubes for some things.  But I don't like the discontinuity from bass to mids.  It's like drum kits are all outfitted with soft mallets instead of sticks and all bass guitar sounds like stand up acoustics being milked for all the sustain they can get from every note.

Next problem is hideous re-tubing cost and availability issues of known excellent tubes.

Next problem - treble roll off and softness.

Some tube units have so much THD that details smudge together and are mitigated in the syrup.

Very pricey tube amps and some hybrids fix some of those issues a bit.

SS like a lot of DACs have many bright hard sounding units.  I found refuge in Pass electronics (bit more THD than typical SS) and Schitt Gumby & Yggy Multi bit DACs.

So why am I here?  Because of Senn 600's unusually great coupling with the BHC.


----------



## Ganymede

Over the last 4 months I've built a crack and progressively molded it (Inc. SB). It's been a real rabbit hole (and a money pit). 

imho, the old skool OG "tubby" sound is overly romanticised. As the mods have been installed one by one, clarity has increased while distortion, bass and holographics have decreased. I would only like the intensity of the holographics return. To me, it is a much better sounding amp now. Subjectively, it sounds great, although I also have a burson GT which is objectively "better". Now, I'm keen to learn to design and build my own tube amp.

Since the SB install, it's run stinking hot. Voltages are within spec and that seems to satisfy the bottlehead forum. It's not a refined product like something Schiit or Woo audio offers.


----------



## ColdsnapBry

I went with the Etsy builder for my latest Crack build, he did a really amazing job. It's just a basic crack with a upgraded pot and choke mod. I've been listening to this much more than my speedball crack.


----------



## Galapac (Jun 1, 2022)

ColdsnapBry said:


> I went with the Etsy builder for my latest Crack build, he did a really amazing job. It's just a basic crack with a upgraded pot and choke mod. I've been listening to this much more than my speedball crack.


That's a nice stand for your amps, may I ask where you got it?

Also that SW looks very similar to the Eddie Current ZDT Jr, shown here:


----------



## ColdsnapBry

Galapac said:


> That's a nice stand for your amps, may I ask where you got it?
> 
> Also that SW looks very similar to the Eddie Current ZDT Jr, shown here:



Thanks! I had the stand made by a local woodworker, we referenced the Salamander Design modular racks but shrank the dimensions for a headphone amp rack.

It does! I believe the SW51+ and EC ZDT Jr. are from the same manufacturuer / one guy.


----------



## MacMan31

So the BHC has arrived. I have it set up and playing some Avengers: Infinity War score now. Sound is really good so far through my HD6XX. I just put in a random pairing of tubes as I got a handful with the Crack. To be honest I'm not quite sure what tubes exactly are in the amp now. I'll just keep trying various combinations to find my preferred sound.


----------



## MacMan31

New Yorker said:


> Well, I received my assembled Crack/SB amp a couple of weeks ago and… I am lovin’ it. I didn’t know, at first, how to have it finished, exactly. Then it hit me; why not echo the look of my ancient Victor Victrola? And so that’s the way we went. I think it worked out well!



That Crack looks awesome. Would it have been possible to get the pattern of the Victor into the sides of the Crack?


----------



## jonathan c

New Yorker said:


> Well, I received my assembled Crack/SB amp a couple of weeks ago and… I am lovin’ it. I didn’t know, at first, how to have it finished, exactly. Then it hit me; why not echo the look of my ancient Victor Victrola? And so that’s the way we went. I think it worked out well!


That’s a Bottlehead Craque !!!


----------



## MacMan31

So on my BHC I notice that I barely need to turn the volume knob to get a more than comfortable volume level. Like not even a quarter turn. Plus at the lowest point I hear sound there is channel imbalance. The volume increase is not very smooth and gradual. Is there any fix for this. I would rather need to turn the knob about half way than barely at all. Seems to be the only real issue I have. Otherwise it works great. Keep in mind I did not build this myself.


----------



## Galapac (Jun 3, 2022)

MacMan31 said:


> So on my BHC I notice that I barely need to turn the volume knob to get a more than comfortable volume level. Like not even a quarter turn. Plus at the lowest point I hear sound there is channel imbalance. The volume increase is not very smooth and gradual. Is there any fix for this. I would rather need to turn the knob about half way than barely at all. Seems to be the only real issue I have. Otherwise it works great. Keep in mind I did not build this myself.


You would need to change your volume pot to either Alps, Audio Note or TKD.
https://www.partsconnexion.com/cgi-...b77f1157d6bb78322a865&search_field=Volume+pot

Others can share their thoughts but I have used 100k Alps in mine with no issues.

You can also use a volume PCB board for cleaner installation.
https://www.ebay.com/itm/275031067565?hash=item4009210bad:g:fVwAAOSwFV9X1nbh


----------



## MacMan31

Galapac said:


> You would need to change your volume pot to either Alps, Audio Note or TKD.
> https://www.partsconnexion.com/cgi-...b77f1157d6bb78322a865&search_field=Volume+pot
> 
> Others can share their thoughts but I have used 20K Alps in mine with no issues.



Okay. I have heard of the Alps one. What is the difference between the various "K" options? They have 10K, 20K, 50K, 100K. Also where could I get a different volume knob if I wanted to change from the one I have (seems to be the stock one).


----------



## Galapac

MacMan31 said:


> Okay. I have heard of the Alps one. What is the difference between the various "K" options? They have 10K, 20K, 50K, 100K. Also where could I get a different volume knob if I wanted to change from the one I have (seems to be the stock one).


Same place:
https://www.partsconnexion.com/cgi-bin/sc/productsearch.cgi?search_field=knob
…or Amazon.
Etsy has them too, just search for knobs.


----------



## MacMan31

Okay perhaps I will check those out. I have never soldered before though.


----------



## raindownthunda

Galapac said:


> Same place:
> https://www.partsconnexion.com/cgi-bin/sc/productsearch.cgi?search_field=knob
> …or Amazon.
> Etsy has them too, just search for knobs.


+1 For parts connexion. The 25mm AudioNote knob is a very nice upgrade.


----------



## MacMan31

I'm starting to think that the DIY kind of amp is not for me. Thankfully I have a Feliks Audio Echo on the way.


----------



## jonathan c

Don’t write off the BHC just yet. If need be, you may find an amplifier repair in the classified adverts - for the volume pot replacement. The BHC, with the right 6080 / 5998 / 6AS7G etc + 12AU7 tube, will work magic.


----------



## MacMan31

jonathan c said:


> Don’t write off the BHC just yet. If need be, you may find an amplifier repair in the classified adverts - for the volume pot replacement. The BHC, with the right 6080 / 5998 / 6AS7G etc + 12AU7 tube, will work magic.



Well I'm sure it's a great amp. But I'm not so much of a DIY kind of person. I have no electrical experience.


----------



## jonathan c

I can’t imagine difficulty in finding a technician to replace a volume pot for the BHC. There are a few Head-Fiers, for example, who have replaced pots on BHC, Liquid Platinum etc. Place an advert…


----------



## GPJ7 (Nov 28, 2022)

........................


----------



## MacMan31

jonathan c said:


> I can’t imagine difficulty in finding a technician to replace a volume pot for the BHC. There are a few Head-Fiers, for example, who have replaced pots on BHC, Liquid Platinum etc. Place an advert…



You mean put an ad in the Classified section? 



GPJ7 said:


> You need to pad the pot with resistors. Your volume situation is a common issue. See item #3 here (and the photo at the bottom of that post) .... this should solve your problem completely:
> 
> https://forum.bottlehead.com/index.php?topic=4295.msg39600#msg39600
> 
> The 100K stock pot shouldn't need upgraded but the Alps and Audio Note are a good choice. Your headphones are causing the issue and even those pots will need to be padded if they are 100K.



I don't see any photos on that page. How are my headphones causing the issue?


----------



## GPJ7 (Nov 28, 2022)

.......................


----------



## MacMan31

GPJ7 said:


> The photo can be seen if you log into the forum.
> 
> There is nothing wrong with your headphones. The Crack is meant to drive high impedance headphones (best with 250 - 600 ohm IME). It will drive low impedance phones but not omptimally and may not sound the best they can. It can also make the volume adjustment a lot more sensitive just like you are experiencing.



Well I'd have to create a log in for the forum. My headphones currently are the HD6XX and ZMF Aeolus though I would like to try other options. My plan is to have one solid state and one tube amp so I can use a variety of headphones. That's why I had gotten the Schiit Lyr 3. It can handle all kinds of headphones and give some "tube sound" as well. Also is it advisable to use an adapter in the front tube socket to be able to use other tube options? I've seen a few BHC posts on Instagram where the front tube is a big (or bigger) tube than the 12AU7 tube. Examples: https://www.instagram.com/p/BfDt1R9BYs-/ and https://www.instagram.com/p/Cc0nkAZO5lL/


----------



## GPJ7 (Nov 28, 2022)

......................


----------



## DenverW

I advise against the garage adapter.  Shorted my crack, and i'm not the only one.  I got mine from xulingmrs on ebay.


----------



## MacMan31

GPJ7 said:


> Roger that. The HD-6XX should give you normal volume control although at 12 o'clock it's going to be maxed for nearly everyone unless liking it really loud.
> 
> Good choice on amps, I'd like to hear a Lyr 3. I had the first version.
> 
> ...



I also think my volume knob was installed sideways. It's not meant to turn Infinitely around. There is a minimum and maximum point that it stops at each end of the volume range. 

I'm intending to sell the Lyr 3 because I now have the BHC and still waiting on a Feliks Audio Echo. I was going to include a bunch of extra tubes with the Lyr 3 but then I saw the adapter to use 6SN7 tubes in the BHC. 

I did see your amp photo. That seems like a pretty high guard. But why would I need one if I'm not touching the tube while the amp is on? I'd only be touching the tube to swap it while the amp is turned off. Yeah I was wondering about other 12Ax7 tubes. I have some really nice Brimar CV455 12AT7 tubes which I was hoping I could use in the Crack. But I can also use them in the Feliks Echo which should arrive tomorrow. 



DenverW said:


> I advise against the garage adapter.  Shorted my crack, and i'm not the only one.  I got mine from xulingmrs on ebay.



Which adapter (if any) would you recommend?


----------



## MacMan31

raindownthunda said:


> Thanks - wood is ziricote. Inspired by the ziricote wood ZMF Aeolus I got a few years back. One of my first woodworking projects, Zach helped me out with tips on the finish process as I wanted them to match the ear cups as closely as possible. Didn’t turn out perfect, but I’m happy with it . I posted a bunch of pics in this gallery a while back: https://imgur.com/a/uATdg3g



Thanks for that link. It's nice to see the process. So do you have your own woodworking shop? That amp looks awesome. Seems like you have the amp resting on top of the wood case instead of slightly recessed inside. That's a sweet double tube adapter as well with some great looking tubes.


----------



## MacMan31

carlman14 said:


> My BHC has been in open heart surgery for the last couple weeks. I did a comparison between using the regulator from my last post and a more traditional CRCLC power supply. I decided to stick with the CRCLC for a few reasons:
> 
> 1. The sound differences between the two PSU implementations were very minor (if any)... minor enough to justfiy not using the regulator. I can save the regulator for another project now.
> 2. CRCLC is running a bit cooler. There is a lot of heat dissipated in the "R" of the CRCLC, and the heat seems to stay more localized to that corner vs the giant regulator heatsink I had in there before.
> ...



Damn that's quite the mod. Can you not use the 6J5 and 12AU7 at the same time? Looks odd having some sockets unused. I only wish I knew how to do all this stuff. But even if I did I don't have the space as I live in an apartment. Especially with something like building a custom wood case.


----------



## jonathan c

DenverW said:


> I advise against the garage adapter.  Shorted my crack, and i'm not the only one.  I got mine from xulingmrs on ebay.


I’ll second that on xulingmrs for adapters. [Use 12A#7 (top) —> 6DE7 (bottom) adapters for 1st Generation Woo WA6: 👍👍]


----------



## carlman14

MacMan31 said:


> Damn that's quite the mod. Can you not use the 6J5 and 12AU7 at the same time? Looks odd having some sockets unused. I only wish I knew how to do all this stuff. But even if I did I don't have the space as I live in an apartment. Especially with something like building a custom wood case.


Wow, feels like forever ago that I posted that. That was quite the wacky experiment I did haha. I never tried using the 12AU7 and 6J5 at the same time, but I didn't mind the unused socket. I actually did all of this in my small Seattle apartment! This stuff is loads of fun to learn about... definitely recommend it.


----------



## MacMan31

carlman14 said:


> Wow, feels like forever ago that I posted that. That was quite the wacky experiment I did haha. I never tried using the 12AU7 and 6J5 at the same time, but I didn't mind the unused socket. I actually did all of this in my small Seattle apartment! This stuff is loads of fun to learn about... definitely recommend it.



Well it's something to consider. But I've never really been the "hands on" kind of guy. Also I'm looking for a right angle adapter given that the headphone jack is on the top. Does it really matter if the plug is "gold plated" or not? Right now I'm using a 1/4" to 4 pin XLR adapter but I worry long term about strain relieve on the cord.


----------



## GPJ7 (Nov 28, 2022)

..................


----------



## DenverW

GPJ7 said:


> That is the first time I've heard of that. Sounds like bad luck.


The design of the adapter didn't mesh well with the crack.  I'm not the only one.  YMMV.


----------



## jonathan c

DenverW said:


> The design of the adapter didn't mesh well with the crack.  I'm not the only one.  YMMV.


Your Music May Vanish?….🤣🤣


----------



## HTSkywalker

Anyone tried Converting the headphone's jack to a side position instead of the upward one ?


----------



## Slade01

Hey guys - just got into the bottlehead crack (w/speedball) world since last month.  After getting a feel for the stock tubes, im starting to tube roll again.  I had a question for those using the Garage 6SN7 adapter.  Is the adapter itself prone to higher noise, or perhaps just by virtue of using any 6SN7 on the amp?  I was just curious.  Sadly, I only have one 6SN7 tube to try so I can't say for sure if its this tube specific, the adapter, or any 6SN7.  LOL.   Not that i'm into them all too much, my preference is for dual 6J5s anyways as I'm using right now.   Thanks!


----------



## bagwell359

HTSkywalker said:


> Anyone tried Converting the headphone's jack to a side position instead of the upward one ?


Side?  If using a wood base it would be tough.  I have considered putting a SE under pointed straight dow - strapped in tight - because I have XLR plug on top.  But an adaptor is easier.


----------



## HTSkywalker

bagwell359 said:


> Side?  If using a wood base it would be tough.  I have considered putting a SE under pointed straight dow - strapped in tight - because I have XLR plug on top.  But an adaptor is easier.


Adapter is definitely easier but better not to introduce any connectors, on the long run the phone cables won't be happy going upwards and curved  😐


----------



## barbz127

Is this adaptor safe to use with the crack?
https://www.ebay.com.au/itm/200952599533


----------



## bagwell359

HTSkywalker said:


> Adapter is definitely easier but better not to introduce any connectors, on the long run the phone cables won't be happy going upwards and curved  😐


I agree on adapter.  But the can I use on the amp is xlr terminated.  If I did add the SE plug it would face out, not down.  That was my initial idea.  But out would be difficult to make solid enough for trouble free use.


----------



## HTSkywalker

bagwell359 said:


> I agree on adapter.  But the can I use on the amp is xlr terminated.  If I did add the SE plug it would face out, not down.  That was my initial idea.  But out would be difficult to make solid enough for trouble free use.


Agree👍


----------



## MacMan31

Which tubes exactly am I able to use in the Crack. Seems I can only use 12AU7 (at least without any adapters) in the front socket but what about the rear socket?


----------



## CaptainFantastic

MacMan31 said:


> Which tubes exactly am I able to use in the Crack. Seems I can only use 12AU7 (at least without any adapters) in the front socket but what about the rear socket?



421A, 5998, 6AS7G, 6080, 6520, 7236 in the rear socket.

In front don't forget ECC82 is the same as 12AU7.


----------



## bagwell359

CaptainFantastic said:


> 421A, 5998, 6AS7G, 6080, 6520, 7236 in the rear socket.
> 
> In front don't forget ECC82 is the same as 12AU7.


E80CC and more


----------



## HTSkywalker

Probably a 6SN7 in the front is the best bet


----------



## MacMan31

bagwell359 said:


> E80CC and more





HTSkywalker said:


> Probably a 6SN7 in the front is the best bet



Just to clarify. I was asking what types will fit the stock sockets and won't require any adapters.


----------



## HTSkywalker (Jun 15, 2022)

MacMan31 said:


> Just to clarify. I was asking what types will fit the stock sockets and won't require any adapters.


This should be helpful
https://forum.bottlehead.com/index.php?topic=6360.0
and yes the 6SN7 would require an adapter


----------



## bagwell359

HTSkywalker said:


> This should be helpful
> https://forum.bottlehead.com/index.php?topic=6360.0
> and yes the 6SN7 would require an adapter


Well a E80CC is a 9 pin that fits.  But use it with Speedball and a resistor value must change.  The makers have a list in the doc that comes with the kit.  Also Google E80CC and 9-pin and visit the list from AliExpress.


----------



## MacMan31

bagwell359 said:


> Well a E80CC is a 9 pin that fits.  But use it with Speedball and a resistor value must change.  The makers have a list in the doc that comes with the kit.  Also Google E80CC and 9-pin and visit the list from AliExpress.



From what I can find the E80CC is pretty pricey. I wonder if these would be any good? 

https://www.langrex.co.uk/products/e80cc-mullard-blue-boxed-nos-valve-tube-lc84/

https://www.langrex.co.uk/products/e80cc-mullard-nos-boxed-valve-tube-lc68/


----------



## bagwell359

MacMan31 said:


> From what I can find the E80CC is pretty pricey. I wonder if these would be any good?
> 
> https://www.langrex.co.uk/products/e80cc-mullard-blue-boxed-nos-valve-tube-lc84/
> 
> https://www.langrex.co.uk/products/e80cc-mullard-nos-boxed-valve-tube-lc68/


Yeah it's not cheap to obtain.  I think you get a very clean sound that has dynamics and the liquid magic.

I would get the exact specs.  The key one IMO is ch balance.  Finding max versions in matched pairs is a major thing - thankfully for this application it does not matter.

My estimate is 75% of these tube dealers are frauds.  In particular eBay guys.  I like Brent Jesse's.  His reviews are worth it alone.

I saw a pinched waist E80CC matched pair for $7500.  Yeah sure..


----------



## smodtactical

Crack OG (no speedball) is amazing. Took down amps I have that cost  10x more. Its truly a magic machine. I prefer OG to speedball version (I have both).

It is very warm, fluid, 3d while still rendering detail very well. Excellent imaging and space.


----------



## HTSkywalker

smodtactical said:


> Crack OG (no speedball) is amazing. Took down amps I have that cost  10x more. Its truly a magic machine. I prefer OG to speedball version (I have both).
> 
> It is very warm, fluid, 3d while still rendering detail very well. Excellent imaging and space.


If by OG you meant the original standard version vs the Speedball added then that's a first. 🙄
But again YMMV situation


----------



## smodtactical

HTSkywalker said:


> If by OG you meant the original standard version vs the Speedball added then that's a first. 🙄
> But again YMMV situation


Even Justin at ampsandsound said he prefers no speedball.

I think a lot of people just just jump right to speedball without really trying og or having og and speedball next to each other to compare.


----------



## DenverW

MacMan31 said:


> Just to clarify. I was asking what types will fit the stock sockets and won't require any adapters.


All of the 12au7 types will fit, such as ecc82 and 5814a.

E80cc will fit but won’t be optimal without small internal changes.  Same thing with the 12bh7 tubes.  

You can find adapters online for tube types like the 6sn7.


----------



## MacMan31

DenverW said:


> All of the 12au7 types will fit, such as ecc82 and 5814a.
> 
> E80cc will fit but won’t be optimal without small internal changes.  Same thing with the 12bh7 tubes.
> 
> You can find adapters online for tube types like the 6sn7.



What about other 12A*7 options?


----------



## pravous

MacMan31 said:


> What about other 12A*7 options?


The 12at7 has gain factor of 60 and the 12ax7 has a gain of 100 vs the @20 for the 12au7 so they are a no go for the BHC.


----------



## JamieMcC (Jun 30, 2022)

MacMan31 said:


> From what I can find the E80CC is pretty pricey. I wonder if these would be any good?
> 
> https://www.langrex.co.uk/products/e80cc-mullard-blue-boxed-nos-valve-tube-lc84/
> 
> https://www.langrex.co.uk/products/e80cc-mullard-nos-boxed-valve-tube-lc68/


 
Fyi be aware I'm pretty sure Mullard didn't make E80cc themselves they will be either rebranded Tungsram or Siemen/Philips who I believe we're the only manufacturers of the E80cc in Europe.

Fwiw Both brands produced very nice sounding tubes with substantially longer life than the 12au7. 

They are a great choice for the Crack when used with the inexpensive resistor mod for optimising voltage. 

Follow the guide on the Bottlehead forum and the mod to add a small switch that allows switching between the correct voltages for 12au7 and E80cc it's a easy and inexpensive (just a few dollars) to do.


----------



## snapple10

skhan007 said:


> Well, I haven't heard the other tube amps you've mentioned, but my BHC is tubbiness maximus! I have gravitated toward the 5998 and RCA clear top 12au7, after some tube rolling. I bought mine pre-made by an expert BHC builder and then had the granite enclosure custom made. I also use ZMF cans and it's a PERFECT pairing (as would be your Senns). While I really like it a lot, I may stick with solid state and go that route. Undecided, but I might sell and fund a solid state amp I have my eye on. Here's mine...


that granite enclosure got my attention on the ZMF thread , nice!!!


----------



## RestoredSparda

Hey all! I have a brand new never used pair of General Electric 5 Star 6005 vacuum tubes available FOR CHEAP if anyone needs for a crackatwoa build.

I was going to go crackatwoa back when, but ended up building a Mainline. PM me for details as these are just sitting in a box and I'd rather someone enjoy them.


----------



## dstarr3

I'm building a media rack that I'd like to design to accommodate an eventual BHC. About how tall is a BHC with tubes installed?


----------



## MacMan31

Any one here from Canada that would be able/willing to make a custom wood base for my BHC? Also where are you all getting your alternate volume knobs?


----------



## skhan007

Gents- I have been using exclusively a clear top RCA 12au7 in my preamp position, but after reading a bit, I feel like I'm standing on the edge of the rabbit hole and hearing positive reviews of the 6sn7 w/ adapter in this position. 

So very simply: I believe the garage1217 adapter is the safe bet for 12au7 to 6sn7 conversion, correct? If there was one brilliant 6sn7 tube to try in the position, what would you recommend?

If I can hear a superior presentation in this position with a good 6sn7, I'll be more likely to explore that rabbit hole! Cheers to all.


----------



## jonathan c (Jul 24, 2022)

•  Before you hitchhike on route 6SN7, try one more tube: the RFT ECC82 ‘foil getter’. It is a remarkable tube. I used these when I owned a Rogue RH-5. I _do _roll them into Woo WA2, WA3, and WA6. Fantastic balance, clarity, dynamics, soundstage: even better than the excellent RCA ‘cleartop’.
•  As for 6SN7 tubes, the best to my ears are: Melz 6N8S/1578 (1960s vintage), Raytheon ‘brown base’ 6SN7GT, CBS / Hytron / Zalytron ‘brown base’ 5692. Excellent 6SN7s also include: Sylvania ‘chrome dome’ 6SN7 and Ken-Rad (Kentucky Radio Corp.) VT-231.
•  Lastly, for the adapter, I recommend the one below from ‘xulingmrs’ (Xuling Audio Lab) on EBay. I have been using XAL adapters on all my Woos (a TV program spinoff 😳🤔?) with _no issues just all 🎼.

_


----------



## skhan007

jonathan c said:


> •  Before you hitchhike on route 6SN7, try one more tube: the RFT ECC82 ‘foil getter’. It is a remarkable tube. I used these when I owned a Rogue RH-5. I _do _roll them into Woo WA2, WA3, and WA6. Fantastic balance, clarity, dynamics, soundstage: even better than the excellent RCA ‘cleartop’.
> •  As for 6SN7 tubes, the best to my ears are: Melz 6N8S/1578 (1960s vintage), Raytheon ‘brown base’ 6SN7GT, CBS / Hytron / Zalytron ‘brown base’ 5692. Excellent 6SN7s also include: Sylvania ‘chrome dome’ 6SN7 and Ken-Rad (Kentucky Radio Corp.) VT-231.
> •  Lastly, for the adapter, I recommend the one below from ‘xulingmrs’ (Xuling Audio Lab) on EBay. I have been using XAL adapters on all my Woos (a TV program spinoff 😳🤔?) with _no issues just all 🎼._


Fantastic! Thank you for all this great information. I will proceed accordingly.


----------



## bagwell359

dstarr3 said:


> I'm building a media rack that I'd like to design to accommodate an eventual BHC. About how tall is a BHC with tubes installed?


Depends.  Stock ones are pretty basic.  I use taller ones as do a fair amount of folk.  I'd give an answer but mine is on loan.  

Do please give it lots of room on all sides, and if you plan on changing tubes and/or cables put it on top or give it more room for that.

Alternately in a cold basement get them close to your feet.


----------



## skhan007

jonathan c said:


> •  Before you hitchhike on route 6SN7, try one more tube: the RFT ECC82 ‘foil getter’. It is a remarkable tube. I used these when I owned a Rogue RH-5. I _do _roll them into Woo WA2, WA3, and WA6. Fantastic balance, clarity, dynamics, soundstage: even better than the excellent RCA ‘cleartop’.
> •  As for 6SN7 tubes, the best to my ears are: Melz 6N8S/1578 (1960s vintage), Raytheon ‘brown base’ 6SN7GT, CBS / Hytron / Zalytron ‘brown base’ 5692. Excellent 6SN7s also include: Sylvania ‘chrome dome’ 6SN7 and Ken-Rad (Kentucky Radio Corp.) VT-231.
> •  Lastly, for the adapter, I recommend the one below from ‘xulingmrs’ (Xuling Audio Lab) on EBay. I have been using XAL adapters on all my Woos (a TV program spinoff 😳🤔?) with _no issues just all 🎼._


Ok, I decided to purchase the adapter pictured above. The seller wants me to confirm that I have 6.3 volts for my current 12au7 tube and not 12 volts. I believe this is true, but can you guys confirm? Is there a pin I should check with my multimeter?


----------



## Galapac

skhan007 said:


> Ok, I decided to purchase the adapter pictured above. The seller wants me to confirm that I have 6.3 volts for my current 12au7 tube and not 12 volts. I believe this is true, but can you guys confirm? Is there a pin I should check with my multimeter?


The crack is 6.3 V for the 12AU7 socket.


----------



## skhan007

Galapac said:


> The crack is 6.3 V for the 12AU7 socket.


Thank you- most appreciated!

I have a few 6sn7 tubes in my tube stash and I figured, why not give them a go. I believe one is a newer Sovtek and two are old RCA brown base. I'll have to double check those.


----------



## pravous

dstarr3 said:


> I'm building a media rack that I'd like to design to accommodate an eventual BHC. About how tall is a BHC with tubes installed?


My BHC with dual 6j5 adaptors is @ 9 1/4 inches tall.  @ 8 1/2 to the top of a 6as7g if you are not using adapter for the 12au7 socket.  With the heat the power tubes give out I would not go anything less the 12 inches in my opinion.


----------



## skhan007

Guys, regarding 6sn7 preamp/driver tubes, I've got the following in my stash that I'd like to try when my 9 pin to 8 pin adapter arrives. I'm pretty sure the tube on the left, the 6SL7 is not compatible, correct? The other three are 6sn7 and two 5691 tubes.


----------



## DatClampTho

Only that Sovtek would work. The 5691 are 6SL7 equivalent and the Crack is not compatible with these.


----------



## MacMan31

Got these for my BHC. Now I can try my 6SN7 tubes from my Lyr 3.


----------



## skhan007

Gents, this is my first 6sn7 venture. Now I’m just patiently waiting for that adapter to arrive.


----------



## MacMan31

So far I'm not sure I have found a 6SN7 tube I like in the BHC. I have 8 or 9 different ones and so far none have overly impressed me.


----------



## Galapac

MacMan31 said:


> So far I'm not sure I have found a 6SN7 tube I like in the BHC. I have 8 or 9 different ones and so far none have overly impressed me.


Have you tried an E80CC tube in place of a 12AU7?
If you have the SB upgrade you can use that tube natively and I prefer them over the 12AU7 tubes myself.


----------



## MacMan31

Galapac said:


> Have you tried an E80CC tube in place of a 12AU7?
> If you have the SB upgrade you can use that tube natively and I prefer them over the 12AU7 tubes myself.



You mean ECC82? I did not know there was an E80CC.


----------



## Galapac

E80CC. They are a bit pricey these days but if you are patient you can find a good deal.
You even commented on it back in June. 😉

Post in thread 'Crack;Bottlehead OTL'
https://www.head-fi.org/threads/crack-bottlehead-otl.476650/post-17008658

Search this thread on E80CC for peoples comments on it.


----------



## MacMan31

Galapac said:


> E80CC. They are a bit pricey these days but if you are patient you can find a good deal.
> You even commented on it back in June. 😉
> 
> Post in thread 'Crack;Bottlehead OTL'
> ...


Yes I do now remember that comment. I also came across this website which sells many tube types. 
https://www.nostubestore.com/search/label/E80CC/6085


----------



## bagwell359

Galapac said:


> Have you tried an E80CC tube in place of a 12AU7?
> If you have the SB upgrade you can use that tube natively and I prefer them over the 12AU7 tubes myself.


With a lot of room to spare.


----------



## skhan007

Galapac said:


> Have you tried an E80CC tube in place of a 12AU7?
> If you have the SB upgrade you can use that tube natively and I prefer them over the 12AU7 tubes myself.





bagwell359 said:


> With a lot of room to spare.


Is there a particular brand/spec that’s recommended?


----------



## DenverW

skhan007 said:


> Is there a particular brand/spec that’s recommended?


I preferred the Phillips sq personally on the e80cc.  However, I also prefer a great  12au7 to the e80cc overall.


----------



## Galapac

skhan007 said:


> Is there a particular brand/spec that’s recommended?


I like the Philips and Valvo red label brands.
Both have solid plates.
Be careful of Siemens being sold with holes in the plates as those are usually knockoffs of cheaper Tungsram tubes.


----------



## skhan007

OK, Gents- I have entered the Rabbit Hole. My 12au7 to 6sn7 adapter arrived and I'm test driving my two current tubes (Raytheon and Sylvania chrome top). Exciting stuff!! My big question (to be answered in the coming days): Will I notice an improvement over the wonderful RCA clear top 12au7?


----------



## bagwell359

DenverW said:


> I preferred the Phillips sq personally on the e80cc.  However, I also prefer a great  12au7 to the e80cc overall.


In that circuit with the correct resistor value change?  Speedball - 475 ohms.


----------



## DenverW

bagwell359 said:


> In that circuit with the correct resistor value change?  Speedball - 475 ohms.


Yeah, even with playing around with the different resistors.  I found the standard 12au7 was behind the e80cc or 6sn7, but that a few of the greats were my overall favorites.


----------



## skhan007

OK, reporting back on my first week with 6sn7 tube(s) in the preamp section. I've gone between the chrome top Sylvania and the Raytheon. They sound pretty much the same to me and both are great. I can likely conclude that I like the 6sn7 as much (or maybe even more) than the RCA clear top 12au7, which was fantastic to begin with.

I do note that the adapter and 6sn7 creates a very, very, low level hum when no music is playing. It does not get louder or quieter when you roll the volume up down on the BHC or source (RME ADI2 DAC). It's inaudible when the music is playing. Just noting that it's NOT a black background. 

When the music is paused and the slight hum is there, and I roll up the BHC volume to about 3/4 (I would never listen to music at this volume) there's a range on the volume knob where there's more hum on the right side of the headphones, but then it disappears when the volume knob gets to max. None of this happens with 12au7 tubes. Weird.


----------



## GreenNeedle (Aug 20, 2022)

skhan007 said:


> OK, reporting back on my first week with 6sn7 tube(s) in the preamp section. I've gone between the chrome top Sylvania and the Raytheon. They sound pretty much the same to me and both are great. I can likely conclude that I like the 6sn7 as much (or maybe even more) than the RCA clear top 12au7, which was fantastic to begin with.
> 
> I do note that the adapter and 6sn7 creates a very, very, low level hum when no music is playing. It does not get louder or quieter when you roll the volume up down on the BHC or source (RME ADI2 DAC). It's inaudible when the music is playing. Just noting that it's NOT a black background.
> 
> When the music is paused and the slight hum is there, and I roll up the BHC volume to about 3/4 (I would never listen to music at this volume) there's a range on the volume knob where there's more hum on the right side of the headphones, but then it disappears when the volume knob gets to max. None of this happens with 12au7 tubes. Weird.


I have that low level hum when using either the ebay adaptor above or the Garage one and with any of the 4 6SN7 I have.  When you say it is inaudible when music is playing it will probably still be there somewhere, just the music puts it way down in the backround.  It annoyed me though and I liked the cheap Mazda 12AU7s so I haven't used a 6SN7 for a long time.


----------



## skhan007

GreenNeedle said:


> I have that low level hum when using either the ebay adaptor above or the Garage one and with any of the 4 6SN7 I have.  When you say it is inaudible when music is playing it will probably still be there somewhere, just the music puts it way down in the backround.  It annoyed me though and I liked the cheap Mazda 12AU7s so I haven't used a 6SN7 for a long time.


Yeah, agreed- The low-level hum is simply overshadowed when the music starts. It's definitely still in the background. A bit frustrating, but oh well. 

Curious if any BHC owners feel their amp, after personalization, tweaks, tube upgrades, etc. is endgame for them? I know many guys have stated this amp, when tweaked, punches above it's weight class. I'm genuinely interested if guys here find this amp to be their main headphone amp?

I've got my eye on a very nice TOTL headphone amp and it's super pricey (to me anyway) at $3700. It makes me wonder if I should just stop and be happy with what I have.


----------



## jonathan c

skhan007 said:


> Yeah, agreed- The low-level hum is simply overshadowed when the music starts. It's definitely still in the background. A bit frustrating, but oh well.
> 
> Curious if any BHC owners feel their amp, after personalization, tweaks, tube upgrades, etc. is endgame for them? I know many guys have stated this amp, when tweaked, punches above it's weight class. I'm genuinely interested if guys here find this amp to be their main headphone amp?
> 
> I've got my eye on a very nice TOTL headphone amp and it's super pricey (to me anyway) at $3700. It makes me wonder if I should just stop and be happy with what I have.


I know which h/p/a that is…😜. One important difference between it and the BHC is that its output impedance is 2.0 ohms vs _an estimated _100 ohms for the BHC. A 300-ohm headphone such as ZMF Auteur will sound different - for that reason (besides others) - with that TOTL h/p/a vs with the BHC.


----------



## skhan007

jonathan c said:


> I know which h/p/a that is…😜. One important difference between it and the BHC is that its output impedance is 2.0 ohms vs _an estimated _100 ohms for the BHC. A 300-ohm headphone such as ZMF Auteur will sound different - for that reason (besides others) - with that TOTL h/p/a vs with the BHC.


Thanks for the feedback, as always. I do really want that "other" TOTL headphone amp, but it's just so pricey. Used ones are super hard to come by. I may just have to bite the bullet and pay the top-dollar pricing. I'm just having a psychological tug-of-war about spending this kind of money. I'm also thinking about TOTL solid state and keeping the BHC for when the need for tube tone strikes.


----------



## jonathan c

skhan007 said:


> Thanks for the feedback, as always. I do really want that "other" TOTL headphone amp, but it's just so pricey. Used ones are super hard to come by. I may just have to bite the bullet and pay the top-dollar pricing. I'm just having a psychological tug-of-war about spending this kind of money. I'm also thinking about TOTL solid state and keeping the BHC for when the need for tube tone strikes.


If you get the “other” TOTL h/p/a, you can make the sound as ‘tubey’ or as close to SS as you like with tube choices. _Very generally speaking, _RCAs and Siemens at each end of the spectrum - for example 🤷🏻‍♂️. Plus that “other” TOTL h/p/a will _deftly _handle low impedance headphones (except Abyss + Susvara).


----------



## Deceneu808

skhan007 said:


> Thanks for the feedback, as always. I do really want that "other" TOTL headphone amp, but it's just so pricey. Used ones are super hard to come by. I may just have to bite the bullet and pay the top-dollar pricing. I'm just having a psychological tug-of-war about spending this kind of money. I'm also thinking about TOTL solid state and keeping the BHC for when the need for tube tone strikes.





jonathan c said:


> If you get the “other” TOTL h/p/a, you can make the sound as ‘tubey’ or as close to SS as you like with tube choices. _Very generally speaking, _RCAs and Siemens at each end of the spectrum - for example 🤷🏻‍♂️. Plus that “other” TOTL h/p/a will _deftly _handle low impedance headphones (except Abyss + Susvara).


----------



## Dawgfish

skhan007 said:


> Yeah, agreed- The low-level hum is simply overshadowed when the music starts. It's definitely still in the background. A bit frustrating, but oh well.
> 
> Curious if any BHC owners feel their amp, after personalization, tweaks, tube upgrades, etc. is endgame for them? I know many guys have stated this amp, when tweaked, punches above it's weight class. I'm genuinely interested if guys here find this amp to be their main headphone amp?
> 
> I've got my eye on a very nice TOTL headphone amp and it's super pricey (to me anyway) at $3700. It makes me wonder if I should just stop and be happy with what I have.


I don't know if its end game but its damn good.  I know you and I PM'd each other about this subject in the past and since then I have added a Bottlehead Mainline.  The Mainline is definitely a step up over the BHC with SB but its not night and day.  Its a matter of degrees.  

For the money the BHC with SB offers outstanding performance.  In my opinion if you want to make major changes in sound you will get more by changing headphones.


----------



## DenverW

skhan007 said:


> Yeah, agreed- The low-level hum is simply overshadowed when the music starts. It's definitely still in the background. A bit frustrating, but oh well.
> 
> Curious if any BHC owners feel their amp, after personalization, tweaks, tube upgrades, etc. is endgame for them? I know many guys have stated this amp, when tweaked, punches above it's weight class. I'm genuinely interested if guys here find this amp to be their main headphone amp?
> 
> I've got my eye on a very nice TOTL headphone amp and it's super pricey (to me anyway) at $3700. It makes me wonder if I should just stop and be happy with what I have.


The crack will always have a special place in my heart.  It was my first tube amp, and my first build.  It is a great, great sounding amp, especially with tweaks and upgrades.  For me, though, it's not end game.  Both the mainline and C2A are better for my listening, and the bigger ben I am currently using is (imho of course!) a fairly big step up over the mainline.  There always seem to be a step up somewhere, I wish I could have remain satisfied.


----------



## Dawgfish

DenverW said:


> The crack will always have a special place in my heart.  It was my first tube amp, and my first build.  It is a great, great sounding amp, especially with tweaks and upgrades.  For me, though, it's not end game.  Both the mainline and C2A are better for my listening, and the bigger ben I am currently using is (imho of course!) a fairly big step up over the mainline.  There always seem to be a step up somewhere, I wish I could have remain satisfied.


I hear you!  Me too!  There's always that curiosity about other stuff and upgraditis is a very real thing in our hobby.  Truth be told though I could live with the BHC with SB for high impedance phones.

The main reason I decided to get something over the BHC was I was looking for a tube amp that could possibly drive the lower impedance phones I have also.  I was surprised to hear the Mainline actually drives the Sundara and Aeon Flow Open X decently at moderate levels.  It will not drive the AFO X at louder levels however.  Luckily I'm very much into high impedance phones at this time and I'm very satisfied with how the BHC, Mainline, and WA6 drives those.  That's not to say that wont change in the future however.  We all know how this hobby goes!  Lol!


----------



## Tom-s

@skhan007 I’m experienced with Crack, C2A, S3X (normal and with E55L) and Mainline(6c45 and ec8020). Headphones used are mostly AKG K340, HD800 and ZMF Verite Open.
Sometimes also AKG K1000 or K340/240 with Stereomour II (2A3 or 45). And various DIY self build amps.

My most used amplifier remains the Crack by a long margin. I just keep going back to it. I like all others but am mostly a Crack addict. Have tried many implementations of Crack. The perfection of Crack is the DC coupled driver. I feel this simplicity makes it perfect.

I don’t own any “end-game” amps in the typical sense of the word. An “end-game” amp with some thousands of euros in components can be mediocre due to implementation in the same way that a very simple thought out circuit can be a perfect base to build a stellar amp.


----------



## skhan007

DenverW said:


> The crack will always have a special place in my heart.  It was my first tube amp, and my first build.  It is a great, great sounding amp, especially with tweaks and upgrades.  For me, though, it's not end game.  Both the mainline and C2A are better for my listening, and the bigger ben I am currently using is (imho of course!) a fairly big step up over the mainline.  There always seem to be a step up somewhere, I wish I could have remain satisfied.





Tom-s said:


> @skhan007 I’m experienced with Crack, C2A, S3X (normal and with E55L) and Mainline(6c45 and ec8020). Headphones used are mostly AKG K340, HD800 and ZMF Verite Open.
> Sometimes also AKG K1000 or K340/240 with Stereomour II (2A3 or 45). And various DIY self build amps.
> 
> My most used amplifier remains the Crack by a long margin. I just keep going back to it. I like all others but am mostly a Crack addict. Have tried many implementations of Crack. The perfection of Crack is the DC coupled driver. I feel this simplicity makes it perfect.
> ...


Very much appreciate your input, Gentlemen. It's a very strange mental tug-of-war that I'm experiencing! I have my BHC Speedball (pictured below) with great tubes. I've bought a stash of 5998 tubes, which I like a tad better than my 6080 and 6as7g tubes. This past month, I tried the 6sn7 preamp tubes with the adapter and really like them, as well (minus the slight hum). The 6sn7 might be a slight improvement over my RCA clear top 12au7. 

Long story short- There is a local amp builder (Linear Tube Audio) and I've visited the shop several times and absolutely love their flagship tube amp, the MZ3. It's just so amazing. It leans a bit away from the typical "tube sound" and is super sharp, defined, crisp, but has that nice tube low end extension. All that being said, it's VERY expensive (for me, anyway). Now, when I listen to my BHC, I just imagine that my listening experience would be better with this other amp, but I also think about how good my BHC sounds at 1/6 the price!!


----------



## Dawgfish

skhan007 said:


> Very much appreciate your input, Gentlemen. It's a very strange mental tug-of-war that I'm experiencing! I have my BHC Speedball (pictured below) with great tubes. I've bought a stash of 5998 tubes, which I like a tad better than my 6080 and 6as7g tubes. This past month, I tried the 6sn7 preamp tubes with the adapter and really like them, as well (minus the slight hum). The 6sn7 might be a slight improvement over my RCA clear top 12au7.
> 
> Long story short- There is a local amp builder (Linear Tube Audio) and I've visited the shop several times and absolutely love their flagship tube amp, the MZ3. It's just so amazing. It leans a bit away from the typical "tube sound" and is super sharp, defined, crisp, but has that nice tube low end extension. All that being said, it's VERY expensive (for me, anyway). Now, when I listen to my BHC, I just imagine that my listening experience would be better with this other amp, but I also think about how good my BHC sounds at 1/6 the price!!


Your Crack is really beautiful! (That didn't sound right! Lol!).  That's the thing I always come back to, sure there are a lot of better tube headphone amps out there but at a significantly higher price. Is the difference in price worth it?  Ultimately that's up to each user to decide.  

Sometimes having equipment with better technicalities doesn't always equal more enjoyment.  In the end the thing that stands out to me about the Crack is how much I enjoy listening to it.  For its price its an exceptional bargain.  I have no doubt there are other tube amps out there that I would probably enjoy more but for a large increase in price.  Sometimes its good to kick back and just enjoy what we have.


----------



## MacMan31

I sold my BHC and kept the Feliks Audio Echo Mk2. Also just traded my Jot 2 for a Rebel Amp. The BHC was pretty good but I think I like the Echo Mk2 better overall.


----------



## Dawgfish (Aug 25, 2022)

Nm


----------



## dstarr3

Aw heck yeah. Just pulled the trigger on a BHC, non-SB.

I intend to primarily pair this amp with my 6XX, secondarily with my MP Sextett, and down the line I may get a Beyer DT880 600ohm that would likely be exclusively driven by my BHC.

That being said, BHC, no Speedball, 6XX/Sextett/DT880, what are some easy-to-acquire tubes that would synergize well? I would like to stay under $100 total, but if there are some tubes north of that that are positively mindblowing in ways you can't get for less, I can be convinced to spend more.


----------



## Dawgfish (Aug 28, 2022)

Congrats! My favorite combination for the BHC with and without SB (have both) is the Chatham 6SA7 power tube and CBS 5814 for driver tube.  I actually prefer the Chatham 6SA7 to the more expensive Tung Sol Domino Plate 5998 (a little bright for my tastes).  RCA Black Plate 6SA7s are a reasonable alternative and sound great!  Mullard, Brimar, Amperex, Telefunken, RCA, CBS, Raytheon, etc. all make excellent sounding 12AU7s (and variants).  The RCA Clear Top 12AU7 can usually be found for pretty reasonable prices.


----------



## dstarr3

Dawgfish said:


> Congrats! My favorite combination for the BHC with and without SB (have both) is the Chatham 6SA7 power tube and CBS 5814 for driver tube.  I actually prefer the Chatham 6SA7 to the more expensive Tung Sol Domino Plate 5998 (a little bright for my tastes).  RCA Black Plate 6SA7s are a reasonable alternative and sound great!  Mullard, Brimar, Amperex, Telefunken, RCA, CBS, Raytheon, etc. all make excellent sounding 12AU7s (and variants).  The RCA Clear Top 12AU7 can usually be found for pretty reasonable prices.


I checked eBay after reading this and I found an auction on a pair of RCA Clear Top 12AU7s that was ending in 45 seconds. I had to act fast and the pair was only $25 shipped, so I bid and won. I'm still new to tubes, so I don't know if these particular examples are better or worse than average. How'd I do?






Description says they measure at 95% and 98% of NOS spec.


----------



## skhan007

dstarr3 said:


> I checked eBay after reading this and I found an auction on a pair of RCA Clear Top 12AU7s that was ending in 45 seconds. I had to act fast and the pair was only $25 shipped, so I bid and won. I'm still new to tubes, so I don't know if these particular examples are better or worse than average. How'd I do?
> 
> 
> 
> Description says they measure at 95% and 98% of NOS spec.


The RCA clear top 12au7 is an EXCELLENT choice! Well done.


----------



## skhan007

Technical question: How much input voltage does the BHC need to “see” coming from one’s source (DAC)? I’m curious if I’m using too much or not enough output from my RME ADI2 DAC into the BHC.


----------



## Beefy

skhan007 said:


> Technical question: How much input voltage does the BHC need to “see” coming from one’s source (DAC)? I’m curious if I’m using too much or not enough output from my RME ADI2 DAC into the BHC.



It doesn't matter. You control how much the input tube sees through the volume control.

That said, the Crack's gain is very high. Cooler sources give a wider range in the volume knob.


----------



## Dawgfish

dstarr3 said:


> I checked eBay after reading this and I found an auction on a pair of RCA Clear Top 12AU7s that was ending in 45 seconds. I had to act fast and the pair was only $25 shipped, so I bid and won. I'm still new to tubes, so I don't know if these particular examples are better or worse than average. How'd I do?
> 
> 
> 
> Description says they measure at 95% and 98% of NOS spec.


Like @skhan007 said above, you done good!  One of the really great things about the BHC is it only uses one driver and one power tube. This makes it relatively less expensive to roll tubes than other designs that use more tubes. 

 As time and budget allows try more tubes until you find the combination you like best for your tastes and equipment.  If you read through this thread you will find many great recommendations.


----------



## skhan007

Dawgfish said:


> Like @skhan007 said above, you done good!  One of the really great things about the BHC is it only uses one driver and one power tube. This makes it relatively less expensive to roll tubes than other designs that use more tubes.
> 
> As time and budget allows try more tubes until you find the combination you like best for your tastes and equipment.  If you read through this thread you will find many great recommendations.


Correct! I've been happy with the RCA clear top 12au7 for about 1.5 years and this past month, per the recommendation of others on this thread, decided to try a 6sn7 w/adapter (very inexpensive, like the RCA clear top option). I really like it a lot.


----------



## Dawgfish (Aug 28, 2022)

Great recommendation! Thanks! I'm eventually going to get around to trying one of the 6SN7s or other similar octal tubes with the BHC.  I see many, many reputable posters such as yourself using them so there definitely has to be something to them.

I know I keep saying this but your BHC and Verite are beautiful!  Stunning combination!


----------



## skhan007

Dawgfish said:


> Great recommendation! Thanks! I'm eventually going to get around to trying one of the 6SN7s or other similar octal tubes with the BHC.  I see many, many reputable posters such as yourself using them so there definitely has to be something to them.
> 
> I know I keep saying this but your BHC and Verite are beautiful!  Stunning combination!


Thanks, much appreciated. Honestly, the guys on this thread have been so incredibly helpful. Many of them have tried everything under the sun and simply recommend their top choices, based on experience. None of the recommendations have been wrong. For example, I loved the GEC 6080 and enough people stated I'd love the 5998 even more. They were right! The RCA clear top was a recommendation and then it was suggested that I try the chrome top Sylvania and Raytheon 6sn7(really inexpensive, by the way) with a recommended adapter- Right again!!


----------



## dstarr3

I also picked up a black-plate RCA 6AS7G just now. Measures 77/74 where 80/80 is NOS.





So between this and the clear-top RCA 12AU7A that I bought earlier, I think I should be all set, yeah?


----------



## Dawgfish

dstarr3 said:


> I also picked up a black-plate RCA 6AS7G just now. Measures 77/74 where 80/80 is NOS.
> 
> 
> 
> So between this and the clear-top RCA 12AU7A that I bought earlier, I think I should be all set, yeah?


Wow!  That was fast! I certainly found the RCA 6SA7 Black Plate and RCA Clear Top 12AU7 combo to be a good one.  Hopefully it will be to your ears also.  Lets us know what you think when everything comes in and you've had a chance to listen for a bit.


----------



## GreenNeedle

Thought I'd just add my up to date aesthetic for my BH crack:





Oh, and remember I said I was gonna re-do my old turntable to match.......................Came out quite well I think:


----------



## Dawgfish

GreenNeedle said:


> Thought I'd just add my up to date aesthetic for my BH crack:
> 
> 
> 
> Oh, and remember I said I was gonna re-do my old turntable to match.......................Came out quite well I think:


Quite well indeed!  Both are beautiful.  Is that a laminate finish and if so what kind?  I really like it!


----------



## GreenNeedle (Sep 5, 2022)

Dawgfish said:


> Quite well indeed!  Both are beautiful.  Is that a laminate finish and if so what kind?  I really like it!


Do you mean the paint?  Rustoleum Mode spray.  Says it is an ultra gloss finish like you get on old fashioned (or modern trendy retro) enamel ovens/fridges.  I layered mine quite thick and left it for a couple of weeks to set.  It came out very slightly rippled like 25% of the Hammerite effect which is what I was after rather than a piano finish:






Or do you mean the wood veneer?  0.6mm Santos Rosewood real wood veneer cut and glued on.  I don't have any photos of the raw veneer from the turntable or the crack.  The below was cut to do my Stereo Receiver.  To gauge size the big piece centre is about 55cm / 22 inches left to right. :




I found one pic from the past that might show it better.  The box on top of the sheet of veneer verses the completed Danish Oiled unit:


----------



## Dawgfish

Its definitely came out well!  It has a very classy look to it.


----------



## Dawgfish

GreenNeedle said:


> Do you mean the paint?  Rustoleum Mode spray.  Says it is an ultra gloss finish like you get on old fashioned (or modern trendy retro) enamel ovens/fridges.  I layered mine quite thick and left it for a couple of weeks to set.  It came out very slightly rippled like 25% of the Hammerite effect which is what I was after rather than a piano finish:
> 
> 
> 
> ...


I was actually referring to the wood veneer so thanks for adding that!  I like the hammered white finish on the top plates also so thanks for providing that info.  The top plate and veneered base go extremely well together.

I'm satisfied with the finish of my BHC w/SB but the finish on my BHC wo/SB could use some work.  Your's definitely gives me some ideas.

Which receiver is that?  I'm a big fan of vintage receivers.


----------



## GreenNeedle (Sep 5, 2022)

Trio (Kenwood) KR-3600:









Anyway, we're way off topic now. lol.  Back to the crack


----------



## Dawgfish (Sep 5, 2022)

Beautiful!  I've heard great things about Trio or Kenwood as they are known in the states.  I have yet to get my ears on one.  I have a couple of Sansuis (G5000 and AU-719 integrated) and a couple of Marantzs (2250B and 2220B).  Vintage receivers are so cool!  Your Trio is gorgeous. It reminds me of my 2250B with the wood case.  Yep agreed back to the Crack.


----------



## skhan007

Decided to swap in this old Bendix slotted 6080 tube, to see how well it paired with the Raytheon 6sn7 (which is a great sounding preamp tube!). Well the Bendix has a real solid punch and really makes the low-midrange and low end really push nicely. Like all my 6080 tubes, it seems to favor these frequencies, while the 5998's really REALLY accentuate clear and crisp upper mids and highs. The Bendix is a nice match to this preamp tube and a different flavor!


----------



## raindownthunda

This is wayyy too much fun: Bifrost 2/64 -> Mullard 6080 + Telefunken G-73R -> ZMF Verite Closed


----------



## GreenNeedle

raindownthunda said:


> This is wayyy too much fun: Bifrost 2/64 -> Mullard 6080 + Telefunken G-73R -> ZMF Verite Closed


Love the wood    Is that setup for banana plugs at the back?


----------



## raindownthunda (Sep 10, 2022)

GreenNeedle said:


> Love the wood    Is that setup for banana plugs at the back?


Thanks! Nah, they are still RCA. Two pairs of these right angle connectors daisy chained so the RCA cables don't jam into the wall lol: https://www.amazon.com/gp/product/B07RDLWFZH/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1


----------



## CaptainFantastic

raindownthunda said:


> This is wayyy too much fun: Bifrost 2/64 -> Mullard 6080 + Telefunken G-73R -> ZMF Verite Closed



I like all the nice customization. Solid brass Audio Note knob, all the adapters to have the cables point in better directions, black screws on the top plate. All the small things that make us enjoy our gear and the experience even more. The Telefunken G-73R looks fantastic. Is it a drop in for 12AU7? Never heard of it, but then again, I'm a noob...


----------



## raindownthunda (Sep 10, 2022)

CaptainFantastic said:


> I like all the nice customization. Solid brass Audio Note knob, all the adapters to have the cables point in better directions, black screws on the top plate. All the small things that make us enjoy our gear and the experience even more. The Telefunken G-73R looks fantastic. Is it a drop in for 12AU7? Never heard of it, but then again, I'm a noob...


Good eye on the knob  You nailed what I love about the Bottlehead kits... doing up all the details makes for an ultra-satisfying experience all-around.

The G-73R is a rare and _very _expensive 12au7 equivalent. Found a (relatively) reasonably priced eBay listing a while ago. Certain forum members who shall not be named hyped them up on the Pendant thread recently, so not much availability and the current listings are wayyy out there. Unfortunately for the wallet, it is very, very nice sounding tube. So far the Mullard has the best power tube synergy. Luscious, liquid, and weighty warmth with tremendous clarity and detail. I generally prefer the 6J5/L63 style tubes over 12au7/6sn7, but the G73R is up there with the best.


----------



## skhan007

raindownthunda said:


> Good eye on the knob  You nailed what I love about the Bottlehead kits... doing up all the details makes for an ultra-satisfying experience all-around.
> 
> The G-73R is a rare and _very _expensive 12au7 equivalent. Found a (relatively) reasonably priced eBay listing a while ago. Certain forum members who shall not be named hyped them up on the Pendant thread recently, so not much availability and the current listings are wayyy out there. Unfortunately for the wallet, it is very, very nice sounding tube. So far the Mullard has the best power tube synergy. Luscious, liquid, and weighty warmth with tremendous clarity and detail. I generally prefer the 6J5/L63 style tubes over 12au7/6sn7, but the G73R is up there with the best.


Wow, yours looks great!! The tube chasing is never-ending. I did this with guitar amps for YEARS and amassed a completely unnecessary amount of tubes, of which 99% just sit in a box, LOL!! I'm trying hard to not do anything similar with the Crack, but I think I'm too late. 

I went through a family of power tubes and they're all really great. The 5998 (Tung Sol & Chatham) is likely my favorite for separation, detail, and high-frequency clarity. The 6080 family hits harder in the lower end and really pushes my ZMF Auteur and VO in a good way, with lower end resonance. The 6as7g is in between the other two. A good medium. 

For preamp, I've enjoyed the RCA clear top 12au7 for a long time, but now I appreciate the 6sn7 (especially this old Raytheon) with the proper adapter. I've also been interested in upgrading caps, but haven't done so yet. I'm trying my hardest not to sink any more more into my BHC, as I might be getting a TOTL tube amp that I've really longed for, so I'm trying to show restraint!!


----------



## SHIMACM

Hello guys!

I have a problem when I use valve drivers with adapters in my Crack w/speedball.

There is often a kind of hissing/static noise in the headphones, which, to temporarily resolve, I have to unplug and reconnect the headphones to the amplifier for the background to go back to black.

This happens with all my headphones.

This is very annoying because I have to do this procedure at least 5 times during my listening session.

The problem occurs when I use 6sn7, 6f8g, 6j5g/l63 valves with 6f8g to 12ua7, 6j5g/l63 to 12ua7 and 6sn7 to 12ua7 adapters.

When I put 12ua7 type valves I don't have this kind of problem.

Has anyone had this kind of problem and managed to solve it?


----------



## skhan007

SHIMACM said:


> Hello guys!
> 
> I have a problem when I use valve drivers with adapters in my Crack w/speedball.
> 
> ...


I have the same issue. Although mine never resolved and I can never have a black background unless I take the adapter out and use a 12au7. I just turn the music up louder!


----------



## SHIMACM

skhan007 said:


> I have the same issue. Although mine never resolved and I can never have a black background unless I take the adapter out and use a 12au7. I just turn the music up louder!



What bad news! But anyone with the same problem? or without it?


----------



## Dawgfish

I have some hiss/noise when I turn the volume pot past 3 o'clock while running 12AU7s.  If I leave the volume below 3 o'clock the noise is slight to very faint to my ears and is non obtrusive.  I use my source volume (dac, phone, or computer) to raise or lower the volume and it has plenty of power to run all of my high impedance phones to ear splitting levels. May be worth a try but then again probably must users are already doing this.


----------



## SHIMACM

Dawgfish said:


> I have some hiss/noise when I turn the volume pot past 3 o'clock while running 12AU7s.  If I leave the volume below 3 o'clock the noise is slight to very faint to my ears and is non obtrusive.  I use my source volume (dac, phone, or computer) to raise or lower the volume and it has plenty of power to run all of my high impedance phones to ear splitting levels. May be worth a try but then again probably must users are already doing this.



I have no problems with 12ua7. The hissing problem is only when I use adapters with the driver valve.


----------



## Dawgfish

SHIMACM said:


> I have no problems with 12ua7. The hissing problem is only when I use adapters with the driver valve.


Gotcha.  Hopefully some of the others will have some advise for you.  I haven't tried anything buy 12AU7s or 5814s in any of my Bottleheads.


----------



## steve468

SHIMACM said:


> Hello guys!
> 
> I have a problem when I use valve drivers with adapters in my Crack w/speedball.
> 
> ...



It could be the actual adapter. I went through 3 6sn7 adapters before I got one that didn’t have a hum. The good one was from Garage 1217. Though I was fine with my first 6f8g adapter. It is a bit weird that it happens for you with ANY adapter…


----------



## raindownthunda

skhan007 said:


> Wow, yours looks great!! The tube chasing is never-ending. I did this with guitar amps for YEARS and amassed a completely unnecessary amount of tubes, of which 99% just sit in a box, LOL!! I'm trying hard to not do anything similar with the Crack, but I think I'm too late.
> 
> I went through a family of power tubes and they're all really great. The 5998 (Tung Sol & Chatham) is likely my favorite for separation, detail, and high-frequency clarity. The 6080 family hits harder in the lower end and really pushes my ZMF Auteur and VO in a good way, with lower end resonance. The 6as7g is in between the other two. A good medium.
> 
> For preamp, I've enjoyed the RCA clear top 12au7 for a long time, but now I appreciate the 6sn7 (especially this old Raytheon) with the proper adapter. I've also been interested in upgrading caps, but haven't done so yet. I'm trying my hardest not to sink any more more into my BHC, as I might be getting a TOTL tube amp that I've really longed for, so I'm trying to show restraint!!


I don’t think there are any tubes I’ve tried I flat out didn’t like, it’s just some synergize better with others, which is what makes the tube rolling journey so fun IMO. That being said, nothing wrong with leaving it alone if it sounds good. It’s very hard to make the BHC sound bad!

What tube amp are you getting next?


----------



## skhan007

raindownthunda said:


> I don’t think there are any tubes I’ve tried I flat out didn’t like, it’s just some synergize better with others, which is what makes the tube rolling journey so fun IMO. That being said, nothing wrong with leaving it alone if it sounds good. It’s very hard to make the BHC sound bad!
> 
> What tube amp are you getting next?


I hope to get the LTA MZ3, which to date, is the best sounding tube amp I’ve ever experienced.


----------



## cebuboy

SHIMACM said:


> What bad news! But anyone with the same problem? or without it?


Did not experience any noise problems with the Garage 1217 6sn7 adapter.


----------



## GreenNeedle

SHIMACM said:


> I have no problems with 12ua7. The hissing problem is only when I use adapters with the driver valve.


After reading around a bit over the past year or more I wondered whether my green wiring from transformer to octal socket to noval socket was twisted tightly enough.  I see some very tight twists on photos so that is one job I intend to do (have been intending to do this for over a year. lol)
There are also some comments about the proximity of a couple of the solders on the noval socket.  Then of course there are the LEDs under the noval socket which might become a little weak when a little tight on the legs.

I daresay that with us all (those of us who do have problems) having them with different adaptors and not with the 12AU7 that the slight difference in powering the 6SN7 might show up a problem that isn't shown up by the 12AU7?



Dawgfish said:


> I have some hiss/noise when I turn the volume pot past 3 o'clock while running 12AU7s.  If I leave the volume below 3 o'clock the noise is slight to very faint to my ears and is non obtrusive.  I use my source volume (dac, phone, or computer) to raise or lower the volume and it has plenty of power to run all of my high impedance phones to ear splitting levels. May be worth a try but then again probably must users are already doing this.


At what point on "the clock" is the zero marker at on yours?  3 'o' clock makes me think of instant deafness.


----------



## skhan007

cebuboy said:


> Did not experience any noise problems with the Garage 1217 6sn7 adapter.


I was planning on purchasing the Garage 1217 adapter, but several on this thread advised against it, having had damage done to their amps as a direct result. I know that doesn't account for everyone, as there are many who didn't have problems with this adapter, but I didn't want to risk it and heeded the words of caution who had bad experiences with the Garage 1217. I bought the Xulingmrs adapter that was recommended. 

My particular observation with my Xulingrmrs adapter: Very very slight hum with my Raytheon 6sn7; slightly more hum with my Sylvania chrome top 6sn7; unbearable and non-ignorable hum with my Sovtek 6sn7GT. The former produces a hum so slight, that it's only heard when there is no music playing. It's inaudible (but likely present) with any music playing. 


GreenNeedle said:


> I daresay that with us all (those of us who do have problems) having them with different adaptors and not with the 12AU7 that the slight difference in powering the 6SN7 might show up a problem that isn't shown up by the 12AU7?


I likely concur with this. I don't know enough about what is going on, however. At first, I thought it must be a grounding issue or perhaps an artifact of the tube itself. I wish I had a proper 6sn7 tube amp to test my tubes, to see if they hum in a different amp. Then, I would know it's definitely the adapter or the BHC.


----------



## Dawgfish

GreenNeedle said:


> After reading around a bit over the past year or more I wondered whether my green wiring from transformer to octal socket to noval socket was twisted tightly enough.  I see some very tight twists on photos so that is one job I intend to do (have been intending to do this for over a year. lol)
> There are also some comments about the proximity of a couple of the solders on the noval socket.  Then of course there are the LEDs under the noval socket which might become a little weak when a little tight on the legs.
> 
> I daresay that with us all (those of us who do have problems) having them with different adaptors and not with the 12AU7 that the slight difference in powering the 6SN7 might show up a problem that isn't shown up by the 12AU7?
> ...


I control the volume via the source not the amp.  The source volume is turned down to moderate levels.


----------



## MacMan31

raindownthunda said:


> This is wayyy too much fun: Bifrost 2/64 -> Mullard 6080 + Telefunken G-73R -> ZMF Verite Closed



That is an amazing BHC. I had one a little while ago but sold it. I could never make one this awesome looking. If I knew someone that could I'd pay them for it. Where did you get the right angle headphone adapter?


----------



## SHIMACM

steve468 said:


> It could be the actual adapter. I went through 3 6sn7 adapters before I got one that didn’t have a hum. The good one was from Garage 1217. Though I was fine with my first 6f8g adapter. It is a bit weird that it happens for you with ANY adapter…



Well, it actually happens with all adapters.

The Garage adapter also read a lot of negative reviews about them.

And something to think about.


----------



## SHIMACM

Can anyone with Crack without Speedball installed, and who uses 6sn7 with adapter, can tell if they are having problems with noise or not?

I'm trying to understand if the speedball contributes to the noise production when using valves like 6sn7, 6j5g, 6f8g.


----------



## pravous

BHC with speedball here.  I too had problems with noise with 6sn7 but found after I got a tester that they were very low testing 6sn7.  I have zero issues with 6j/c5g.


----------



## skeptic (Sep 15, 2022)

SHIMACM said:


> Can anyone with Crack without Speedball installed, and who uses 6sn7 with adapter, can tell if they are having problems with noise or not?
> 
> I'm trying to understand if the speedball contributes to the noise production when using valves like 6sn7, 6j5g, 6f8g.



It has been years, but you can add me to the list of those who tried multiple 6sn7 tube adapters and never managed to get one that didn't introduce significant noise.  I eventually gave up on that avenue and added an early iteration of maxhawke's bias selector board to my crack.  Been very happy with an amperex pq e80cc + 5998 ever since (other mods - TKD 2511 pot, 100uf Obbligato coupling caps, and psu choke).  Candidly, I liked GEC 6as7g in the back even better than the 5998, but mine eventually died, and the cost of a replacement appears to be more than my Mainline lol.  Hard pass.


----------



## dstarr3

Aw yeah. Gonna be a fun weekend


----------



## bpiotrow13

dstarr3 said:


> Aw yeah. Gonna be a fun weekend


I missed the recent sale, but i am thinking of ordering the kit anyway. Good luck!


----------



## dstarr3

bpiotrow13 said:


> I missed the recent sale, but i am thinking of ordering the kit anyway. Good luck!


I missed it, too. I paid regular price.


----------



## jonathan c

dstarr3 said:


> I missed it, too. I paid regular price.


*D*amn, *I* *Y*elled…😤


----------



## dstarr3

Should I pick up a different volume pot before I get much further in assembly? Like an Alps 100K Blue Velvet or something? The volume pot seems to be a highly recommended component to upgrade. Any other component I should consider upgrading before assembly, too?


----------



## Beefy

dstarr3 said:


> Should I pick up a different volume pot before I get much further in assembly? Like an Alps 100K Blue Velvet or something? The volume pot seems to be a highly recommended component to upgrade. Any other component I should consider upgrading before assembly, too?



Yeah, the idea of rolling and comparing pots is a bit silly, so starting with something good from the start is a lot easier. Alps Blue is OK. I have a TKD 2CP2511 which is better.

Most important thing to consider from the start is some way to mount big output caps. Screwed in mounting tabs for physical connection, and fly leads for electrical connection.


----------



## dstarr3

Beefy said:


> Yeah, the idea of rolling and comparing pots is a bit silly, so starting with something good from the start is a lot easier. Alps Blue is OK. I have a TKD 2CP2511 which is better.
> 
> Most important thing to consider from the start is some way to mount big output caps. Screwed in mounting tabs for physical connection, and fly leads for electrical connection.


<checks price of TKD 2CP2511>



Okay, Alps money is much more my speed at the moment, lol. For $20, is it worth using instead of the pot Bottlehead ships with the Crack kit?


----------



## skeptic

dstarr3 said:


> <checks price of TKD 2CP2511>
> 
> 
> 
> Okay, Alps money is much more my speed at the moment, lol. For $20, is it worth using instead of the pot Bottlehead ships with the Crack kit?



I have the same tkd that Beefy recommended in my crack, and it is a very nice pot. That said, I view it as a non-essential upgrade, and it is easy enough to replace in the future if you decide the channel imbalance at the very lowest volumes are a problem in your setup.

I actually ended up repurposing the stock crack pot in my wire se-se build years after the fact.  Had planned on it as a temporary measure to get things up and running, but since it is a unity gain amp, I never really have the volume below 8pm anyway.  Five or six years later, I still haven't come up with a reason to swap it.  TLDR - film output caps and tubes are a better spot to sink funds to my ears - subject to the channel imbalance comment above.


----------



## Galapac (Sep 17, 2022)

dstarr3 said:


> <checks price of TKD 2CP2511>
> 
> 
> 
> Okay, Alps money is much more my speed at the moment, lol. For $20, is it worth using instead of the pot Bottlehead ships with the Crack kit?


To make your life easy if you install the Alps pot get a pcb board from eBay for like a buck. You may need to shave/snip one side to make it fit.
I used a Dremel to trim mine.
it’s better than trying to solder onto the pins of the pot.


----------



## GreenNeedle

I have the same TKD as Beefy and skeptic.  It really is super smooth to turn as well.


----------



## bpiotrow13

Beefy said:


> . I have a TKD 2CP2511 which is better.


I see three values values: 10K, 50K and 100K. Which one would be the proper one?


----------



## Beefy

bpiotrow13 said:


> I see three values values: 10K, 50K and 100K. Which one would be the proper one?



The kit is 100k. A 50k would be fine too. My Crack has the 50k, padded by 50k resistors in series, which gives -6dB additional attenuation.

With regard to the relative importance of the attenuator as an upgrade.... People put it low on the list, but I think that sells it short. The entire signal goes through the attenuator, just the teeniest little strip of carbon film and a wiper sliding along it. I can't think of a more critical place where sound could get degraded.


----------



## Tom-s

I've finished a Crack the other day. And thought it was time to share a family picture.


----------



## skhan007

Tom-s said:


> I've finished a Crack the other day. And thought it was time to share a family picture.


Let me be the first to say, you have a beautiful family!!


----------



## CaptainFantastic

Tom-s said:


> I've finished a Crack the other day. And thought it was time to share a family picture.



Awesome! I think I know who two of those are destined for.  

Question. Where is the volume knob on that Super-Crack?


----------



## bpiotrow13

Beefy said:


> The kit is 100k. A 50k would be fine too. My Crack has the 50k, padded by 50k resistors in series, which gives -6dB additional attenuation.
> 
> With regard to the relative importance of the attenuator as an upgrade.... People put it low on the list, but I think that sells it short. The entire signal goes through the attenuator, just the teeniest little strip of carbon film and a wiper sliding along it. I can't think of a more critical place where sound could get degraded.


Thanks. I see also Black beauty alps is available. Is it better than TKD 2CP2511?


----------



## Beefy

bpiotrow13 said:


> Thanks. I see also Black beauty alps is available. Is it better than TKD 2CP2511?



Honestly don't know. Its conductive plastic like the TKD, which is generally considered a good step up over carbon film. But check the size, I think it might be too big to fit in the intended spot in the Crack.


----------



## dstarr3

Ahhh, duck it, I'll just go for the TKD.


----------



## Beefy (Sep 18, 2022)

dstarr3 said:


> Ahhh, duck it, I'll just go for the TKD.



Parts Connexion has regular 20% off sales. Try not to pay full price!


----------



## bpiotrow13

Beefy said:


> Honestly don't know. Its conductive plastic like the TKD, which is generally considered a good step up over carbon film. But check the size, I think it might be too big to fit in the intended spot in the Crack.


Thanks! A lot of things to consider.


----------



## SHIMACM

Now my Crack is showing the same hiss even with the 12ua7 valves.

This rules out the possibility that the problem is only with the valves that need adapters.

Does anyone know what can it be?

It's a kind of interference noise, which sometimes disappears when I disconnect and reconnect the phone in Crack.

As the amplifier I bought already built, I don't know how to restate all the components of the amplifier.


----------



## raindownthunda

SHIMACM said:


> Now my Crack is showing the same hiss even with the 12ua7 valves.
> 
> This rules out the possibility that the problem is only with the valves that need adapters.
> 
> ...


Is it in both channels or just one? Did you buy the amp from a builder that you can ask to service it? I had a similar issue and turned out to be a weak solder connection on one RCA jack (it was just in one channel). Since you’ve ruled out tubes, it’s either external interference (eg dimmer switches, cell phones, etc) or mechanical connection with a weak solder joint. Since you said it happens as a result of connecting/disconnecting headphones my bet is a solder joint. Your best bet is to post on the bottlehead forums, Paul B. Is usually very helpful in troubleshooting with you there. It‘a likely they will recommend doing some voltage and/or resistance tests with a multimeter and reflowing solder joints. Either way they should be able to help if you explain what’s going on.


----------



## SHIMACM

raindownthunda said:


> Is it in both channels or just one? Did you buy the amp from a builder that you can ask to service it? I had a similar issue and turned out to be a weak solder connection on one RCA jack (it was just in one channel). Since you’ve ruled out tubes, it’s either external interference (eg dimmer switches, cell phones, etc) or mechanical connection with a weak solder joint. Since you said it happens as a result of connecting/disconnecting headphones my bet is a solder joint. Your best bet is to post on the bottlehead forums, Paul B. Is usually very helpful in troubleshooting with you there. It‘a likely they will recommend doing some voltage and/or resistance tests with a multimeter and reflowing solder joints. Either way they should be able to help if you explain what’s going on.



It's on both channels.

The person I bought it from is not a professional builder and lives too far away to ship it.

There is no outside interference. Because the amplifier is in the same place as always and before it was not having any problems.

From what you told me it may actually be a problem with a weak solder point, as connecting and disconnecting the problem temporarily solves it.

I'll look for help on the Bottlehead forum.

Thank you very much!


----------



## SHIMACM

I managed to solve the hissing problem.

Now everything is silent as before.

Even with the adapters, everything is silent.

The problem was a bad solder where the headphones are connected.


----------



## larcenasb

Beefy said:


> Parts Connexion has regular 20% off sales. Try not to pay full price!


Got some caps for a Crackatwoa build, they have ASC 60uF 500V film caps at 91% off... $4.49 each, so it was a no-brainer. The caps have radial leads, but I can get creative and make it work since it's under $10 a pair.

BTW, anyone use sound deadening material under a Crackatwoa? I have some under my Crack to help with some of my microphonic tubes. With it, the microphony is lessened, especially when touching the amp, using the volume knob. Just not sure how much hotter the Crackatwoa gets, and I wanna make sure I don't overlook anything....


----------



## larcenasb (Sep 27, 2022)

Found another Crackatwoa build on Google images using sound deadening. I think I'm being a worry wart about the potential heat....the sound-deadening material has been fine in my Crack for years, and the temp is unlikely to be much different with the Crackatwoa. If anyone has experience with it long-term though, I'd love to be reassured. I'm just starting my build 

To be clear, attached is the build with sound deadening I found, not my build.


----------



## DenverW

larcenasb said:


> Found another Crackatwoa build on Google images using sound deadening. I think I'm being a worry wart about the potential heat....the sound-deadening material has been fine in my Crack for years, and the temp is unlikely to be much different with the Crackatwoa. If anyone has experience with it long-term though, I'd love to be reassured. I'm just starting my build
> 
> To be clear, attached is the build with sound deadening I found, not my build.


As long as there is airflow through the top vents and especially under the amp it should be fine.


----------



## bagwell359

larcenasb said:


> Found another Crackatwoa build on Google images using sound deadening. I think I'm being a worry wart about the potential heat....the sound-deadening material has been fine in my Crack for years, and the temp is unlikely to be much different with the Crackatwoa. If anyone has experience with it long-term though, I'd love to be reassured. I'm just starting my build
> 
> To be clear, attached is the build with sound deadening I found, not my build.


Nice looking piece!  Redoing my Crack so it's displayable.  

Some ideas.  Based on experience I think dynamat would deaden cheaply.  Sorbothane is expensive and doesn't adhere well.  Dynamat might not like to be to close to hot pieces however.

 Also on another front I will use use anti RFI sheeting all over the inside and on long wire runs.

Those rubber feet they give you to mount on the bottom are meh.  I'm working on gold speaker spikes mounted on kiln dried maple dowels affixed with gorilla hot glue on the inside corners.  The veneer of the case is too thin to mount any rugged spikes.  I would mount the dowels about 1/3" in so there is no chance of seeing them but spikes give at least 3/4" more space under the case than the rubber.

Comments welcome.


----------



## dstarr3

These look fun if vibration is a concern. https://smile.amazon.com/Audiocrast-Isolation-Protector-Dampening-Vibration/dp/B08MPBXG6M

Easy to design and 3D print if you've got the ability, too


----------



## larcenasb (Oct 20, 2022)

bagwell359 said:


> Nice looking piece!  Redoing my Crack so it's displayable.
> 
> Some ideas.  Based on experience I think dynamat would deaden cheaply.  Sorbothane is expensive and doesn't adhere well.  Dynamat might not like to be to close to hot pieces however.
> 
> ...


Hi there! I finished building my Crackatwoa last weekend. I can say now the temp isn’t a concern for the sound-deadening material. The top plate gets warm after hours of use, but never hot. I use NVX 90 mil butyl sound deadener.

Also, I wouldn’t worry about the anti-RFI sheeting unless you have serious problems with RFI where your audio gear is. The amp is dead quiet. Separate issue, but it even silences my USB DACs when other amps amplify the hash and buzzing at louder volumes.

Loving the Crackatwoa so far though. I’ll write a detailed comparison between my heavily-modded Crack and the Crackatwoa after a few weeks. Cheers! Oh, and here are some photos in the meantime.


----------



## DenverW

larcenasb said:


> Hi there! I finished building my Crackatwoa last weekend. I can say now the temp isn’t a concern for the sound-deadening material. The top plate gets warm after hours of use, but never hot. I use NVX 90 mil butyl sound deadener.
> 
> Also, I wouldn’t worry about the anti-RFI sheeting unless you have serious problems with RFI where your audio gear is. The amp is dead quiet. Separate issue, but it even silences my USB DACs when other amps amplify the hash and buzzing at louder volumes.
> 
> Loving the Crackatwoa so far though. I’ll write a detailed comparison between my heavily-modded Crack and the Crackatwoa after a few weeks. Cheers! Oh, and here are some photos in the meantime.


Love the green on the top!  Great aesthetic touch!


----------



## larcenasb

DenverW said:


> Love the green on the top!  Great aesthetic touch!


Thanks DenverW  I thought why not give it a little more pop


----------



## CaptainFantastic

larcenasb said:


> Hi there! I finished building my Crackatwoa last weekend. I can say now the temp isn’t a concern for the sound-deadening material. The top plate gets warm after hours of use, but never hot. I use NVX 90 mil butyl sound deadener.
> 
> Also, I wouldn’t worry about the anti-RFI sheeting unless you have serious problems with RFI where your audio gear is. The amp is dead quiet. Separate issue, but it even silences my USB DACs when other amps amplify the hash and buzzing at louder volumes.
> 
> Loving the Crackatwoa so far though. I’ll write a detailed comparison between my heavily-modded Crack and the Crackatwoa after a few weeks. Cheers! Oh, and here are some photos in the meantime.



Very nice customization touches, the color, the volume knobs, on/off switch. Well done!


----------



## Galapac (Oct 20, 2022)

larcenasb said:


> Hi there! I finished building my Crackatwoa last weekend. I can say now the temp isn’t a concern for the sound-deadening material. The top plate gets warm after hours of use, but never hot. I use NVX 90 mil butyl sound deadener.
> 
> Also, I wouldn’t worry about the anti-RFI sheeting unless you have serious problems with RFI where your audio gear is. The amp is dead quiet. Separate issue, but it even silences my USB DACs when other amps amplify the hash and buzzing at louder volumes.
> 
> Loving the Crackatwoa so far though. I’ll write a detailed comparison between my heavily-modded Crack and the Crackatwoa after a few weeks. Cheers! Oh, and here are some photos in the meantime.


Well thought out customization. I like how you routed the wires from the RCAs, nice touch!


----------



## warp2600

larcenasb said:


> Hi there! I finished building my Crackatwoa last weekend. I can say now the temp isn’t a concern for the sound-deadening material. The top plate gets warm after hours of use, but never hot. I use NVX 90 mil butyl sound deadener.
> 
> Also, I wouldn’t worry about the anti-RFI sheeting unless you have serious problems with RFI where your audio gear is. The amp is dead quiet. Separate issue, but it even silences my USB DACs when other amps amplify the hash and buzzing at louder volumes.
> 
> Loving the Crackatwoa so far though. I’ll write a detailed comparison between my heavily-modded Crack and the Crackatwoa after a few weeks. Cheers! Oh, and here are some photos in the meantime.


Gosh, that's so beautiful! Well done. I wish I had the skills...


----------



## larcenasb (Oct 20, 2022)

warp2600 said:


> Gosh, that's so beautiful! Well done. I wish I had the skills...


Thank you, CaptainFantastic, Galapac, and warp2600 

A couple members pm’d me asking about what mods I did, so I should’ve posted that here from the get-go. Sorry hehe, but here you go….

- Audio Note balance and volume pots
- Multicap PPFXS 0.1uF 600V RC filter film caps
- ASC LTI 4-5 60uF 500V output film caps (60uF is okay because even with 33uF output caps, 250 ohm headphones will still play down to 20 Hz at -3 db, and below 200 ohm headphones really shouldn’t be used with an OTL amp. Also, these caps are 91% off on partsconnection.com, so at $5 a pop, it was too good a deal to pass up for film caps. Keep in mind these are very large and would need creative mounting to fit in the smaller Crack.)
- Output cap rolling mod: Velcro straps instead of zip-ties, and then spade connectors and flexible cable from an old RCA composite video cable that has been unused for over a decade (I’m going to also use this as a preamp, so caps as small as 2uF will work fine for that… it’ll be fun to try some nice caps at the lower-cost capacitance)
- custom control overlay (quickly designed it in Paint (the Art Deco font is called DK Otago) then had someone on Etsy make a proof, laser-cut the acrylic, then engrave and powder coat the text/numerals. I was surprised it all only cost $25 plus shipping.)
- NVX 90 mil butyl sound deadening to underside of top plate (to reduce user-handling microphonics)
- heavy-duty toggle power switch (with custom-cut hard plastic as a washer to cover the corners of the original square cutout …. plastic was from a container lid)
- Wood base has 4 inner posts for way-more-than-needed sturdiness
- 4 coats of Tried & True varnish oil to wood base, inside and out (lol, this was a labor of love!)
- Power transformer bell cap has 4 coats of automotive-grade Rust-Oleum Custom matte emerald green spray paint
- top plate has 4 coats of Rust-Oleum Universal hammered silver spray paint
- custom rear info badge (for anyone in the future who gets this when I’m gone, at least they’ll know what it is, what tubes are needed, and a little of the company’s history)
- knobs are from AliExpress, solid aluminum, so many to choose from….
- DIY 3.5mm-to-RCAs Canare cable (for preamp use)
- Octal adapters: 6SN7GT-to-12AU7 & 6F8G-to-12AU7 (both 6.3V)

And I think that’s everything….lol, I’m just on my phone and going off memory. Still, not nearly as many mods as my Crack + Speedball. The Crackatwoa really doesn’t need much (only pot and output caps really), the circuit is fantastic and let me tell you the weight of that power transformer is seriously serious. Cheers


----------



## larcenasb

warp2600 said:


> Gosh, that's so beautiful! Well done. I wish I had the skills...


I think you can get there with practice! If there’s something else stopping you though and you want one of these amps, PM me and perhaps I could build you one for a reasonable fee.


----------



## buencamino

Hi, relatively new owner to a crack... been liking it so far with my HD800S... and gaming with it is great too... maybe just that lately it's been giving me cracks/static at random moments, and I may need to check the solder joints with chopsticks for any incorrect joints... but looking forward to learn in this thread...


----------



## larcenasb

buencamino said:


> …I may need to check the solder joints with chopsticks for any incorrect joints... but looking forward to learn in this thread...


Congrats, you’re getting so much for your money. And many before you have loved what the Crack’s smooth sounds does for the HD 800. Enjoy!

Also, if you’re unable to find out the problem, don’t hesitate to go over to the Bottlehead forum and post in the Crack section. The Bottlehead team are very active there and quick to help. Usually you’ll just have to post your voltage/resistance checks and attach some photos of your wiring/solder joints. Hope you get it all fixed up. Cheers!


----------



## SHIMACM

buencamino said:


> Hi, relatively new owner to a crack... been liking it so far with my HD800S... and gaming with it is great too... maybe just that lately it's been giving me cracks/static at random moments, and I may need to check the solder joints with chopsticks for any incorrect joints... but looking forward to learn in this thread...



Until recently I was having static/squeaking problems in my Crack.

I reinforced all the welds and the problem was solved.

Total silence, even using valves with adapters.


----------



## SHIMACM

Guys, I'm thinking of modifying my Crack, changing the output caps for the film ones and adding a choke.

Which ones do you recommend and where can I buy them?


----------



## larcenasb (Oct 22, 2022)

SHIMACM said:


> Guys, I'm thinking of modifying my Crack, changing the output caps for the film ones and adding a choke.
> 
> Which ones do you recommend and where can I buy them?


Hey, I was going to let someone else answer, but since you haven't gotten a response yet, here you go:

The brand and model aren't so important here, the main thing is to have film caps, in general, handling the audio signal. The Crack is a simple circuit, so no need to spend crazy amounts. Just make sure the diameter of the caps doesn't exceed 54mm, otherwise you'll have to get creative with mounting. For reference, my Audyn Q4 68uF 400V caps are 52mm in diameter and fit nicely on each side of the chassis (see attached photo).

Here are some of the usual suspects:

Mundorf MKP 100uF 250V 46mm-diameter ~$120/pair (partsconnexion.com)
Dayton 100uF 250V 51mm-diameter ~$80/pair (parts-express.com)
Audiophiler 100uF 250V 50mm-diameter ~$60/pair (eBay)
Panasonic EZPE 100uF 500V 35mm-wide (rectangular cuboid shape, so mounting may be a little odd) ~$44/pair (newark.com)

Also, you can get away with lower-capacitance caps (see attached chart). This will save you space and money. If you follow Bottlehead's recommendation and only use headphones that are 200 ohms or greater, then output caps as low as 47uF will still allow frequencies just below 20Hz to pass at -3 db. Again, I use 68uF caps and notice no bass roll-off with the 300-ohm Sennheiser HD 600 or 600-ohm AKG K240 Sextetts.

Here are some more options:

Mundorf MKP 68uF 250V 43mm-diameter ~$72/pair (partsconnexion.com)
Audyn Q4 68uF 400V 52mm-diamter ~$53/pair (parts-express.com)
Solen PB 68uF 400V 49mm-diameter ~$51/pair (partsconnexion.com)
Audiophiler 68uF 250V 39mm-diameter ~$36/pair (eBay)

Just in case, remember it's recommended that you drill holes to secure zip-tie mounts with a screw and nut. If you just use adhesive zip-tie mounts, eventually the weight of the caps and the heat of the top plate will cause the adhesive to let up and the caps can fall.

For a choke, the Triad C-7X is a common choice .... ~$12 (digikey.com)

If you are wondering more about upgrading, I wrote a whole guide that's gotten buried deep within this thread: https://www.head-fi.org/threads/crack-bottlehead-otl.476650/post-16152725

Hope this helps. Cheers.


----------



## DenverW

Another option that I used was the KZK white line capacitors 100uf.  Very good value for the caps based on their price...BUT...they ship from Russia.  I checked on ebay just now and it mentioned the seller is out through dec 31st.  Great caps, bad timing.


----------



## larcenasb

DenverW said:


> Another option that I used was the KZK white line capacitors 100uf.  Very good value for the caps based on their price...BUT...they ship from Russia.  I checked on ebay just now and it mentioned the seller is out through dec 31st.  Great caps, bad timing.


Never saw those before, thanks for the info. I like the clean look of them. But whoa, it says seller is away till Dec 31st, *2030*!!

https://www.ebay.com/itm/332678750938


----------



## DenverW (Oct 22, 2022)

I liked them in my first crack build; inexpensive, clean sound, and weren't so big I had to make a mess of everything.  For the already warm crack they're a good choice.

But, again...getting them from Russia...


----------



## SHIMACM

larcenasb said:


> Hey, I was going to let someone else answer, but since you haven't gotten a response yet, here you go:
> 
> The brand and model aren't so important here, the main thing is to have film caps, in general, handling the audio signal. The Crack is a simple circuit, so no need to spend crazy amounts. Just make sure the diameter of the caps doesn't exceed 54mm, otherwise you'll have to get creative with mounting. For reference, my Audyn Q4 68uF 400V caps are 52mm in diameter and fit nicely on each side of the chassis (see attached photo).
> 
> ...


Thanks for the very detailed answer.


----------



## buencamino

larcenasb said:


> Congrats, you’re getting so much for your money. And many before you have loved what the Crack’s smooth sounds does for the HD 800. Enjoy!
> 
> Also, if you’re unable to find out the problem, don’t hesitate to go over to the Bottlehead forum and post in the Crack section. The Bottlehead team are very active there and quick to help. Usually you’ll just have to post your voltage/resistance checks and attach some photos of your wiring/solder joints. Hope you get it all fixed up. Cheers!


Thank you!



SHIMACM said:


> Until recently I was having static/squeaking problems in my Crack.
> 
> I reinforced all the welds and the problem was solved.
> 
> Total silence, even using valves with adapters.


When you say reinforced, did you re-solder all the joints/welds?


----------



## SHIMACM

buencamino said:


> Thank you!
> 
> 
> When you say reinforced, did you re-solder all the joints/welds?



Yup. But I didn't remove the old solders. I reinforced them all.


----------



## buencamino

SHIMACM said:


> Yup. But I didn't remove the old solders. I reinforced them all.


this meant touching it with the soldering iron, just melt it and fixed it up again..?


----------



## bagwell359

buencamino said:


> this meant touching it with the soldering iron, just melt it and fixed it up again..?


Make sure you have resin to add if you are retouching.  Cold solder joints is what you'll get if not.  If you are using solder with resin core to retouch unless it's a dry joint you risk the chance of solder splashing and excess blovs - shorts waiting to happen and a very poor look.


----------



## SHIMACM

buencamino said:


> this meant touching it with the soldering iron, just melt it and fixed it up again..?



In my case I didn't melt anything. I just added more solder and reinforced the ones that were already there.


----------



## bagwell359 (Oct 27, 2022)

SHIMACM said:


> In my case I didn't melt anything. I just added more solder and reinforced the ones that were already there.


Wait, the original solder wasn't melted?  Soldering fresh adjacent to existing is not good.  Does the new solder have resin in it?  That's better but solder with no resin added to the existing?  Ugh.

What components are involved?  Based on a lot of experience i'm very careful.  For instance I never solder or resolder chips directly into boards (use sockets), and whenever possible I use heat sinks to keep anything from heat damage.  Everything is tied down and all checked with a 10x loup looking for splashes, cracks, cold joints, etc.

For anyone reading this - lots of guides on-line.  It's not rocket science, but it's not trivial if one wants perfect results.


----------



## larcenasb

Given that one of my messages SHIMACM quoted had been translated, I was thinking there was some loss in translation.

But yeah, to be clear, the iron should stay on the joint long enough to be reheated sufficiently, so that all the solder melts....and then making sure the iron is touching both the terminal and the wire/lead. Then wait a couple of seconds and pull off the iron. Perfect and shiny joint.


----------



## bagwell359

larcenasb said:


> Given that one of my messages SHIMACM quoted had been translated, I was thinking there was some loss in translation.
> 
> But yeah, to be clear, the iron should stay on the joint long enough to be reheated sufficiently, so that all the solder melts....and then making sure the iron is touching both the terminal and the wire/lead. Then wait a couple of seconds and pull off the iron. Perfect and shiny joint.


Yes, with resin present.  Sorry if specified earlier.  No resin, bad joint.


----------



## SHIMACM

bagwell359 said:


> Wait, the original solder wasn't melted?  Soldering fresh adjacent to existing is not good.  Does the new solder have resin in it?  That's better but solder with no resin added to the existing?  Ugh.
> 
> What components are involved?  Based on a lot of experience i'm very careful.  For instance I never solder or resolder chips directly into boards (use sockets), and whenever possible I use heat sinks to keep anything from heat damage.  Everything is tied down and all checked with a 10x loup looking for splashes, cracks, cold joints, etc.
> 
> For anyone reading this - lots of guides on-line.  It's not rocket science, but it's not trivial if one wants perfect results.



I actually use google translate. My mother language is Portuguese. I melt the previous solder and add more solder. The end result remains. Black background.


----------



## bagwell359

SHIMACM said:


> I actually use google translate. My mother language is Portuguese. I melt the previous solder and add more solder. The end result remains. Black background.


Excellent!


----------



## MacMan31

Check out this BHC. It's not mine but it's really cool. I love the volume knob. Looks like a combination lock. 
https://old.reddit.com/r/headphones/comments/yjoled/another_bottlehead_crack_hd650_combo/


----------



## larcenasb

Whoa, a small version knob and a larger one! It has very nice OCD-level wiring as well. Hope it's still getting lots of play time.


----------



## dstarr3

And another Crack has been born into this world!






I got a little carried away on the casework. I took a stab at mirror-polishing the steel plate and the transformer cap. I did as good a job as my limited patience would allow, lol. If there's a next time I build one of these, I'm just going to take the metal parts down to my local auto body shop and ask them to polish them for me.

I also prepped and painted the power transformer with some spray-on truck bed liner because I didn't like the raw look with the chicken wire resin pattern. Bed liner paint is particularly good to use here since it has a nice texture that hides small imperfections in the laminations and it has a high temperature tolerance without needing to be cured.

Two coats of golden oak Danish oil.

The soldering was by far the easiest part, lol. I'm used to working on much smaller devices. I just followed the instructions, it passed all the resistance and voltage checks first time, and sounds perfect. No channel imbalance, no cracking, popping, buzzing, etc. Always a good feeling when complicated projects work out without any drama.

Replaced the stock pot before assembly with a TKD 2CP-2511 as recommended here earlier. I don't know what the stock pot sounds like, but this one sure sounds and feels great. I'll get a fancier pot knob later.

This was a super fun and rewarding project. Thanks, everybody, for all the advice along the way!


----------



## Dawgfish

dstarr3 said:


> And another Crack has been born into this world!
> 
> 
> 
> ...


Congrats and gorgeous build!


----------



## pravous

dstarr3 said:


> And another Crack has been born into this world!
> 
> 
> 
> ...


Amazing work.  Polishing the plate and bell cover must have taken some elbow grease.  Base crack or have you added the speedball yet?   BHC and 6xx got me hooked on tubes. Wish I had more patience when I assembled mine.  Didn’t give the paint enough time to cure and resting it upside down in the chassis left marks. Happy listening!


----------



## dstarr3

Dawgfish said:


> Congrats and gorgeous build!


Thanks!



pravous said:


> Amazing work.  Polishing the plate and bell cover must have taken some elbow grease.  Base crack or have you added the speedball yet?   BHC and 6xx got me hooked on tubes. Wish I had more patience when I assembled mine.  Didn’t give the paint enough time to cure and resting it upside down in the chassis left marks. Happy listening!


Thanks! Yeah, I random-orbit-sanded it up to 3000-grit, then got some buffing wheels for my cordless drill with some metal polish and went to town. Took forever and still doesn't look as good as I wanted, lol. I threw in the towel at "good enough." It's not a skill I feel any particular desire to master.

This is the base BHC, I'd read some reviews that suggested the Speedball upgrade undoes a lot of the "tube magic" that the base BHC was loved for, so I figured I'd start off without it. Maybe down the line I'll pick up another BHC kit with the SB upgrade and A/B the two. But for now I'm satisfied with my base one.


----------



## Dawgfish

dstarr3 said:


> Thanks!
> 
> 
> Thanks! Yeah, I random-orbit-sanded it up to 3000-grit, then got some buffing wheels for my cordless drill with some metal polish and went to town. Took forever and still doesn't look as good as I wanted, lol. I threw in the towel at "good enough." It's not a skill I feel any particular desire to master.
> ...


No problem!  I own a BHC with SB and one without.  I love both of them.  They both have their strong points.  One day I plan on upgrading the caps and volume pot with the one without SB.


----------



## larcenasb

Great job! And very cool eye-shaped wood grain


----------



## dstarr3

Also, if anyone is looking for some vibration-dampening feet, either for their BHC or in general, these are on sale:
https://smile.amazon.com/gp/product/B08MPBXG6M?psc=1

I linked them not too long ago. But right now they're on sale for $16, plus a coupon for a further 35% off, making the final price a little over $10.


----------



## Galapac

dstarr3 said:


> Also, if anyone is looking for some vibration-dampening feet, either for their BHC or in general, these are on sale:
> https://smile.amazon.com/gp/product/B08MPBXG6M?psc=1
> 
> I linked them not too long ago. But right now they're on sale for $16, plus a coupon for a further 35% off, making the final price a little over $10.


These are pretty good and I use them under my turntable between a butcher block and granite stone. Never had a skip, even jumping around.
They are adjustable in that you can add/remove springs as needed for tension.


----------



## bpiotrow13

I have just pulled the trigger for the BHC and would like to join the club. While waiting for delivery i am thinking of the upgrades. I would not go for speedball but would rather focus on output caps. I was thinking of Mundorf Capacitor 100uF 350Vdc MCap® EVO Oil.

Is it good choice? Would be grateful for any thoughts/suggestions. I will use BHC with hd650 (and zmf aeolus in future).


----------



## Tom-s

It’s a very good choice quality wise. But I’d strongly advice to build it first and see for yourself how it will fit. These are very big and it’s possible they don’t fit with the normal woodwork. 
I’ve had good experiences with normal Mundorf mcap 100uf. 
Here’s some before / after pictures on how those fit.


----------



## bpiotrow13

Tom-s said:


> It’s a very good choice quality wise. But I’d strongly advice to build it first and see for yourself how it will fit. These are very big and it’s possible they don’t fit with the normal woodwork.
> I’ve had good experiences with normal Mundorf mcap 100uf.
> Here’s some before / after pictures on how those fit.


Thanks, i have found suggestions here and understood these Mundorf will fit:

https://www.headphonesty.com/2019/04/upgrading-bottlehead-crack-headphone-amplifier/

Maybe i should go for Audyn caps as suggested by Doc B? Will Mundorf be much better (it is also slightly larger)? I am also not sure if aluminium oil is not too soft sounding.


----------



## bagwell359 (Nov 11, 2022)

dstarr3 said:


> Thanks!
> 
> 
> Thanks! Yeah, I random-orbit-sanded it up to 3000-grit, then got some buffing wheels for my cordless drill with some metal polish and went to town. Took forever and still doesn't look as good as I wanted, lol. I threw in the towel at "good enough." It's not a skill I feel any particular desire to master.
> ...


Yes the Speedball makes it less obviously tube - more towards a hybrid feeling with tighter bass, more definition, and a little more clarity in the upper end of the treble.  But you'd never mistake it for a Class AB SS 200 wpc.


----------



## bpiotrow13

bagwell359 said:


> Yes the Speedball makes it less obviously tube - more towards a hybrid feeling with tighter bass, more definition, and a little more clarity in the upper end of the treble.  But you'd never mistake it for a Class AB SS 200 wpc.


I guess there are diverse opinions on speedball. Most people consider it as major upgrade but some says it takes away charm. I decided to start without and decide on speedball later.

While waiting for my kit I am hesitating if to upgrade output caps or to built stock crack first and see how it sounds.


----------



## GreenNeedle

bpiotrow13 said:


> Thanks, i have found suggestions here and understood these Mundorf will fit:
> 
> https://www.headphonesty.com/2019/04/upgrading-bottlehead-crack-headphone-amplifier/
> 
> Maybe i should go for Audyn caps as suggested by Doc B? Will Mundorf be much better (it is also slightly larger)? I am also not sure if aluminium oil is not too soft sounding.



These Mundorf's fit and this is in the original base not a heightened one:


----------



## bagwell359

bpiotrow13 said:


> I guess there are diverse opinions on speedball. Most people consider it as major upgrade but some says it takes away charm. I decided to start without and decide on speedball later.
> 
> While waiting for my kit I am hesitating if to upgrade output caps or to built stock crack first and see how it sounds.


The directions advise building it stock first for simplicity sake - and that gets you both experiences when you redo it.

To me the stock is like a sepia photo, the Speedball is like a standard B&W.  And my favorite amp ever the Pass X-150 is like Kodachrome 25 developed properly on a large format Hasselblad (for the true film buffs).


----------



## bpiotrow13

GreenNeedle said:


> These Mundorf's fit and this is in the original base not a heightened one:


Good i think aluminium oil version is the same as aluminium only. I wonder which would better suit.


----------



## bpiotrow13

bagwell359 said:


> To me the stock is like a sepia photo, the Speedball is like a standard B&W


Understood. I fully understand why some may not like it. One of my milestones findings in audio was realising that i do not like neutral sound


----------



## DenverW

bpiotrow13 said:


> I guess there are diverse opinions on speedball. Most people consider it as major upgrade but some says it takes away charm. I decided to start without and decide on speedball later.
> 
> While waiting for my kit I am hesitating if to upgrade output caps or to built stock crack first and see how it sounds.


Stock first, both to know what any improved components bring later and in case you need any assistance with the build.


----------



## bagwell359 (Nov 11, 2022)

bpiotrow13 said:


> Good i think aluminium oil version is the same as aluminium only. I wonder which would better suit.


No they are not.  IMO aluminum oil is the best price/performance combo they offer but only for mids and highs.  Too huge and too expensive for bass (talking xovers).  The aluminum/oil make for really good bypass caps.


----------



## bpiotrow13

bagwell359 said:


> No they are not


Ah, my typo, i wanted to say the aluminium oil is the same size as aluminium version only


----------



## bpiotrow13

GreenNeedle said:


> These Mundorf's fit and this is in the original base not a heightened one:


Looks nice, how did you stick those black stripes (holding mundorf caps) to the cover?


----------



## bpiotrow13

bagwell359 said:


> No they are not.  IMO aluminum oil is the best price/performance combo they offer but only for mids and highs.  Too huge and too expensive for bass (talking xovers).  The aluminum/oil make for really good bypass caps.


So You recommend to take aluminium only version?

The price difference between aluminium and aluminium oil is not that big.


----------



## pravous

The only component I would change for a first time build is the volume pot.  That same upgrade post on headphone honesty lists the usual contenders.  I opted for the Audio note 100k pot and I have been very happy with it.  I left mine stock for about a month before installing the speedball, which in my opinion was a clear upgrade.   Maybe upgrade the output caps when installing the speedball as the connections for the output caps will be harder to get at once the large speedball board is installed. Good luck with the build.  Looking forward to seeing some pictures.


----------



## bagwell359

bpiotrow13 said:


> So You recommend to take aluminium only version?
> 
> The price difference between aluminium and aluminium oil is not that big.


I believe I was clear: 

aluminum/oil > aluminum


----------



## bpiotrow13

pravous said:


> I opted for the Audio note 100k pot


Cool, You recommend it over Blue Alps? I guess it is easier to soldier.


----------



## bpiotrow13

bagwell359 said:


> I believe I was clear:
> 
> aluminum/oil > aluminum


Ok, i misunderstood. Thanks.


----------



## lost&confused (Nov 12, 2022)

bpiotrow13 said:


> I have just pulled the trigger for the BHC and would like to join the club. While waiting for delivery i am thinking of the upgrades. I would not go for speedball but would rather focus on output caps. I was thinking of Mundorf Capacitor 100uF 350Vdc MCap® EVO Oil.
> 
> Is it good choice? Would be grateful for any thoughts/suggestions. I will use BHC with hd650 (and zmf aeolus in future).


I really recommend the russian white line KZK caps if you can find them (100uf 250v
I've had those Mundorf evo oils and the normal Mcaps and the russians are far better
The KZK are bigger than the mundorfs be harder to fit with the speedball installed


----------



## pravous

bpiotrow13 said:


> Cool, You recommend it over Blue Alps? I guess it is easier to soldier.


Most blue alps have pins instead of holes for the solder connections.  There are circuit boards that make it easier to attach to.  When I built my crack I couldn’t find any blue alps in stock anywhere so I went with the Audio note.


----------



## bpiotrow13

lost&confused said:


> I really recommend the russian white line KZK caps if you can find them (100uf 250v
> I've had those Mundorf evo oils and the normal Mcaps and the russians are far better
> The KZK are bigger than the mundorfs be harder to fit with the speedball installed


Got it, how would You describe difference (soundwise) between mundorf normal and evo oil?


----------



## lost&confused (Nov 12, 2022)

I'm not the best at describing sound sorry ,  I did prefer the normal mcaps over the oils tho ( I did lots of burnin
They both sounded kinda dull way too smooth and lifeless ,ok not really bad  but when I installed the russian caps I was gobsmacked

Get the russians


----------



## lost&confused




----------



## lost&confused (Nov 12, 2022)

I had to cut flush 2 of the solder lug terminal strips at the top (they are unused anyway )  both sides of the power supply to move them up
with the speedball tho it will be very tight

Used these cable tie mounts https://www.ebay.co.uk/itm/192096947037 
I had to raise these cable tie mounts up another 5mm for them to fit
fixed with m4 screws 12mm long
https://www.ebay.co.uk/itm/321232365051?var=510171044574
with doomed nuts
https://www.ebay.co.uk/itm/320938286430?var=510070811405


----------



## bpiotrow13

lost&confused said:


>


Quite an achievment to fit it in


----------



## lost&confused

my old crack with the oils .. I've owned built 3 cracks over the years also had the crackatwoa
crack is a great amp with great tubes !


----------



## dstarr3

lost&confused said:


>


Sweet pair of Dagmars you got there


----------



## bpiotrow13

lost&confused said:


> my old crack with the oils .. I've owned built 3 cracks over the years also had the crackatwoa
> crack is a great amp with great tubes !


Nice

How did You fix those black stripes (around caps) to the top plate?


----------



## lost&confused (Nov 12, 2022)

I used the normal cable tie mounts with the sticky backs on the mundorfs .  I still used screws and the doom head nuts to hold them on tho
Lots of guys just stick them on not using no screws
If you just stick them on clean the surface well and use a few drops of superglue aswell
https://www.ebay.co.uk/itm/203773678057?hash=item2f71db91e9:g:WG8AAOSwiBlhzHbr&amdata=enc:AQAHAAAA4PCLxAjFI4+LzWplnDde934ntgdIW42G6wDszdUr0xpZPpbJS75aOjJueOtZM7lJljjOfjsiFH4zpWXv+l0VKaAiZJR1JKIesYQ9NklX7CdFAMmykQQqJNLW3zQCzJtPffnCpkxFLb1oYf22h41w68b7U3PdCc8Ne0Dp+UTfjlsVHCcCbudhwF6NEEgieqVYYIpbNRxshfQIBdLtXjtlPbQaF898ZmT+W6sGRFzUAz2zbK+Dk9vntNoEQGU4bzLj5Qm/Y/5c1l1wjNJYDGz6EwBLJmUnD/TuOkjyXGbhAnji|tkp:BFBMwPSMzI1h


----------



## bpiotrow13

lost&confused said:


> I used the normal cable tie mounts with the sticky backs on the mundorfs .  I still used screws and the doom head nuts to hold them on tho
> Lots of guys just stick them on not using no screws
> https://www.ebay.co.uk/itm/20377367...DGz6EwBLJmUnD/TuOkjyXGbhAnji|tkp:BFBMwPSMzI1h


Thanks, thisnis exactly what i was looking for!


----------



## lost&confused

your welcome


----------



## lost&confused

you could use 2 sticky mounts for each cap to make it stronger if it works ....But i never needed to  using screws


----------



## GreenNeedle

bpiotrow13 said:


> Looks nice, how did you stick those black stripes (holding mundorf caps) to the cover?


 The 2 on the sides are cable tie bases epoxied to the back of the top plate  The one over the transformer I made a stand bending a metal strip and securing it under the transformer bolts so it continues the grounding.


----------



## bpiotrow13

GreenNeedle said:


> The 2 on the sides are cable tie bases epoxied to the back of the top plate  The one over the transformer I made a stand bending a metal strip and securing it under the transformer bolts so it continues the grounding.


Thanks, it is still before me. For now i am collecting the stuff required for crack assembly (paits, soldier, ect). Lots of things to buy and learn while waiting for the crack. 

I have no experience in building any electronics, but there is a lot of information available also in this forum. Looks like i will have lots of fun


----------



## bagwell359

lost&confused said:


>


Like it!   Clean.


----------



## DenverW

Couple notes on the Kzk white line caps; I believe they come available with a higher vdc rating if needed.  It’s been a while but I believe either 400 or 600 vdc; I’d have to check.

Also, it took three months to arrive from Russia.  This was long before the war, so who knows nowadays?


----------



## lost&confused (Nov 15, 2022)

Yeah I looked for the ebay store just now and it looks banned
The price for the mundorf oils is £110 each in the UK
£220 on caps is way to much money I paid £52 for pair the russian Kzk
You can get carried away much better buying better tubes than caps

or maybe bpiotrow is loaded with money if so go for it!


----------



## DenverW

Or don’t worry on cap upgrades for a crack and save for the crackatwoa .


----------



## bpiotrow13

lost&confused said:


> or maybe bpiotrow is loaded with money if so go for it!


Do I sound so?  I need to pause with spending for a while and I need to put together my BHC first...



DenverW said:


> Or don’t worry on cap upgrades for a crack and save for the crackatwoa .



It may be a good idea to think if to upgrade the BHC or to concider crackatowa. but not now.. Now my patience is exposed to long wait for BHC. I am almost ready with all tools:


----------



## lost&confused (Nov 16, 2022)

use a small chisel tip if you can as it's much easier better than the pensil type
think mines 1.6mm for my weller (not sure tho)
and buy some solder wicking braid to desolder if you make a mistake

https://www.youtube.com/@bottleheadaudio

And get some good wire stripper ..very important
https://www.amazon.co.uk/gp/product/B001HQMWNY/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1


https://www.ebay.co.uk/itm/363876353823?hash=item54b8b8871f:g:SP8AAOSw0KtfR9h~&amdata=enc:AQAHAAAA4I4y6zZfeGBUu9VbYN72P5C6D2X1YWHiTNwDma/lRiOofRsicwwi4thMWk5K1MMHNPNIolF/TZhLoiAQlFQ443qwidc8etT9oBMvTEZwNHyDvaa72oXqOyBI8JFRTKCTPX1QJAK9Zi3thaLhIon9tk32VOi9iKtCneUDyDmEKxfDG+BDL4TuVFuKver7qapL0V911OXqcGDxPQV4hnbC9BA3QN5x7C/E9MhRLeXRk7Dt/7XJXv6DDZbbZ4A+xHVk/awae/K/VEqdnTBke1PTqQwIEuTisj5OtXSlOUubRZwe|tkp:BFBMkO2H_49h


----------



## bpiotrow13

lost&confused said:


> and buy some solder wicking braid to desolder if you make a mistake


Thanks, already bought


----------



## SHIMACM

lost&confused said:


> my old crack with the oils .. I've owned built 3 cracks over the years also had the crackatwoa
> crack is a great amp with great tubes !



What reasons led you to dispose of Crackatwoa and just stick with Crack? Did you feel that Crackatwoa was not a significant upgrade over Crack?


----------



## lost&confused (Nov 16, 2022)

I really like the non speedball with the hd600 best

With the crackatwo I didn't hear much of a change when tube rolling ( tung sol 5998 and mullard 12au7 1950's square getters) I already had these

The speedball and crackatwo are a bit too bright and thin for me when using the hd600's and missing a little tubey sound .... maybe using the hd650 I can see why ppl like the speedball upgrade better as they are not as bright.
Tho With the Normal Speedball crack I can hear a difference tube rolling.

Also I play very loud volumes and the non speedball sounds ace up high ...it sends the hd600's into overdrive 

I think the bass hits harder its smoother with great detail still (sounds better up loud)

I have the hd650 but don't like them

for me non speedball with great tubes sounds the best.


----------



## SHIMACM

lost&confused said:


> I really like the non speedball with the hd600 best
> 
> With the crackatwo I didn't hear much of a change when tube rolling ( tung sol 5998 and mullard 12au7 1950's square getters) I already had these
> 
> ...



I really like the valve bearing Crack w/speedball with the HD650.

I never used the version without the Speedball.

Crack w/speedball sounds great with GEC 6as7g/GEC l63 tubes; WE421a/Melz 1578; TS 5998/TS 6f8g; GEC 6080/Fivre 6c5g, among others.

I seriously thought about upgrading to Crackatwoa due to the comments.

But like you said, Crackatwoa is brighter and doesn't respond much to valve bearing.

Maybe I should stay with Crack anyway.


----------



## lost&confused

i should really edit my comment on the speedball , I was  going off what I remember

I've not heard the speedball in years now so its hard for me to say 

You've got me buying the speedball now !


----------



## pravous

bpiotrow13 said:


> Do I sound so?  I need to pause with spending for a while and I need to put together my BHC first...
> 
> 
> 
> It may be a good idea to think if to upgrade the BHC or to concider crackatowa. but not now.. Now my patience is exposed to long wait for BHC. I am almost ready with all tools:



That band clamp should make assembling the base pretty easy.


----------



## bpiotrow13

pravous said:


> That band clamp should make assembling the base pretty easy.


At least I hope so

This is really a madness for me to go into DIY gear as I have no experience here, but it is very exciting as well. I thought I need to try.

If I make It I will have a nice amp


----------



## GreenNeedle

lost&confused said:


> I really like the non speedball with the hd600 best
> 
> With the crackatwo I didn't hear much of a change when tube rolling ( tung sol 5998 and mullard 12au7 1950's square getters) I already had these
> 
> ...



This echoes what I remember too.  I listened to the crack much more when it was minus speedball and I'm not so inclined to use it since.  Its just lost that "something" that was  making drawing me to listen to much more music than usual.

I've been umming and ahhing about reversing the speedball for probably over a year now and apart from laziness it was reading the sheer amount of posts that are speedball positive.  I think I should go with my own impressions though and your post seems to be similar to mine.  I am using modded HD580s mostly so similar to your 600s.  I'll have to look into what I need to replace though as I snipped the resisters and bits out to put the speedball in.


----------



## lost&confused (Nov 16, 2022)

exactly how I felt with the speedball too
At first I didn't like it  then i used the 5998 with mullard then I was like yes!
sold it after years as I wasn't using it

bought another one a year later with no speedball and loved it with my old tubes

So so that bought a crackatwo but for some reason I loved the stock...it just play excellent at high volumes my old hd600s thump with them
yeah the crackatwo is more detail darker background but when I turned it up loud it just didn't have that magic

now on my 3rd crack 
yes im an odd ball


----------



## Dawgfish (Nov 16, 2022)

I have two Cracks one with and one without Speedball.  I like both of them very much.  Honestly I listen to the Speedball one much more often even when listening with TS 5998s as power tubes in both.  I also really enjoy the Chatham 6AS7 with both.  I mostly use CBS Hytron black plate 5814s with both for input tubes.

I must caveat that I rarely listen to either my HD600 or HD6XX any more.  I listen to my ZMFs mainly with them and they are both superb with ZMFs.  It just matters what mood I'm in whether I listen to the tubier and more lush Crack without Speedball or the faster, more detailed Crack with Speedball.  Either way both give excellent sound and both are incredible values.


----------



## SHIMACM

Can anyone else here who has or has Crackatwoa comment on how it responds to valve bearings?


----------



## steve468

SHIMACM said:


> Can anyone else here who has or has Crackatwoa comment on how it responds to valve bearings?


Me personally, I don't think it responds any better or worse than any other tube amp. Changing the tubes makes an audible difference (again, at least to me). I think with any tube amp it takes some experimentation to find the tubes you like; you may find that the "popular" choices aren't what you're looking for. For example, I'm not a huge fan of the vaunted 5998, because I find it too smooth. I didn't know that until I tried it, and found something missing.

Different tubes are not going to change the amp, it's a matter of dialing in or emphasising the features of the amp you like. In my opinion, of course.

As an aside, to respond to one of your earlier comments: I never had the Crack and Crackatwoa at the same time (they were separated by a long 'twoa build time for me), but I thought the upgrade was worth it. The Crackatwoa is less mid-bassy and much more even in frequency response. Some people like the Crack sound. I think you can add that magic back with tube choice.


----------



## SHIMACM

steve468 said:


> Me personally, I don't think it responds any better or worse than any other tube amp. Changing the tubes makes an audible difference (again, at least to me). I think with any tube amp it takes some experimentation to find the tubes you like; you may find that the "popular" choices aren't what you're looking for. For example, I'm not a huge fan of the vaunted 5998, because I find it too smooth. I didn't know that until I tried it, and found something missing.
> 
> Different tubes are not going to change the amp, it's a matter of dialing in or emphasising the features of the amp you like. In my opinion, of course.
> 
> As an aside, to respond to one of your earlier comments: I never had the Crack and Crackatwoa at the same time (they were separated by a long 'twoa build time for me), but I thought the upgrade was worth it. The Crackatwoa is less mid-bassy and much more even in frequency response. Some people like the Crack sound. I think you can add that magic back with tube choice.



I like a warm and lush sound well.

With the right valves, crack does it for me.

From what you said, Crackatwoa has a more neutral sound, and consequently, colder, I believe.


----------



## bagwell359

I like when amps are coherent from top to bottom.  Pass SS amps with a small dose of harmonic richness is my ideal.

The BHCs with the E80CC is no X Series Pass, but to me the magic comes through without receding highs and overly warm mid bass.  Its a tube alright but with some hybrid leanings (I.E. more neutral but hardly cold)


----------



## DenverW

SHIMACM said:


> Can anyone else here who has or has Crackatwoa comment on how it responds to valve bearings?


The c2a doesn't change as much with tube rolling as the crack does.  That being said, the c2a with basic tubes has a blacker background, more space, more bass, and overall (imho!!!) sounds better than the crack with high end tubes.  There isn't as big of a gap with the c2a between super expensive totl tubes and others, but it's still there.  

The difference is I could sell my western electric 421a tubes and use good mid level centron tubes on the c2a and still get amazing sound.

The mainline doesn't respond to tube rolling pretty much at all, but is even higher end sound than the c2a.  However, it is even less "tube" than the c2a, which is less "tube" than the crack with speedball, which is less "tube" than the baseline crack.  I fit into the c2a level, personally, as my sweet spot between tube euphoria and clarity, imaging, bass, ect.  Only you can say where your sweet spot is.


----------



## Dawgfish (Nov 20, 2022)

DenverW said:


> The c2a doesn't change as much with tube rolling as the crack does.  That being said, the c2a with basic tubes has a blacker background, more space, more bass, and overall (imho!!!) sounds better than the crack with high end tubes.  There isn't as big of a gap with the c2a between super expensive totl tubes and others, but it's still there.
> 
> The difference is I could sell my western electric 421a tubes and use good mid level centron tubes on the c2a and still get amazing sound.
> 
> The mainline doesn't respond to tube rolling pretty much at all, but is even higher end sound than the c2a.  However, it is even less "tube" than the c2a, which is less "tube" than the crack with speedball, which is less "tube" than the baseline crack.  I fit into the c2a level, personally, as my sweet spot between tube euphoria and clarity, imaging, bass, ect.  Only you can say where your sweet spot is.


Good description.  Not trying to be contrarian but I can hear a noticeable difference when rolling tubes in my Mainline.  I must caveat that I am running Mundorf caps on my Mainline so that may account for the difference.  You are right though rolling tubes in the Mainline does not make as much as a difference as with the Crack. 

I think the oddball 6C45pi are a big reason for that. There is just not a big variety of those tubes and they can be hard to source.  Fortunately I was able to source some early 70s production 6C45pi tubes out of Ukraine.  They are noticably warmer and less sterile than the stock later production Sovteks or gold pin EHs.  The combination of the early production 6C45pi power tubes with a RCA black plate 12AU7 or CBS Hytron 5814s and the Mundorf caps actually gives the Mainline a much warmer sound.  Its similar in tone to the BHC with SB with good tubes while retaining the advantages of detail, soundstage, imaging, and tighter bass of the stock Mainline. I find it a lot more engaging than stock. 

Having said all of that I still enjoy listening to the Crack with and without SB just as much as the Mainline.  It just depends on what mood I'm in.  I would definitely love to get my ears on the C2A one day but frankly after picking up the Mogwai I have no real need or desire to pickup anything else.  It does everything I need in a tube headphone amp.  I thought the Mainline was going to be that amp but it's lack of power when driving inefficient headphones led me to keep looking.


----------



## SHIMACM

DenverW said:


> The c2a doesn't change as much with tube rolling as the crack does.  That being said, the c2a with basic tubes has a blacker background, more space, more bass, and overall (imho!!!) sounds better than the crack with high end tubes.  There isn't as big of a gap with the c2a between super expensive totl tubes and others, but it's still there.
> 
> The difference is I could sell my western electric 421a tubes and use good mid level centron tubes on the c2a and still get amazing sound.
> 
> The mainline doesn't respond to tube rolling pretty much at all, but is even higher end sound than the c2a.  However, it is even less "tube" than the c2a, which is less "tube" than the crack with speedball, which is less "tube" than the baseline crack.  I fit into the c2a level, personally, as my sweet spot between tube euphoria and clarity, imaging, bass, ect.  Only you can say where your sweet spot is.



I'm still trying to find my sweet spot. Of one thing I'm sure. I prioritize feeling soul/emotion in music more than technical details.

So I must sell my HD800s and stick with Veritè.

As for the amplifier, I like the magic of the tubes, so much so that I'm thinking of trying the Crack without the Speedball or a Woo Wa2, for example.


----------



## bpiotrow13 (Nov 20, 2022)

SHIMACM said:


> So I must sell my HD800s and stick with Veritè.
> 
> As for the amplifier, I like the magic of the tubes, so much so that I'm thinking of trying the Crack without the Speedball or a Woo Wa2, for example


Verite shines with tubes but You need to match the amplifier to You liking. I guess the amps You mentioned sounds differently. I have not heard BHC yet (it is on its way to me), but wa2 is very clear sounding, less tubey amp. I had it and sold it due to lack of charm. 
This does not mean it is not good, but really apms differ and You need to choose the one You like.


----------



## dstarr3

I've been meaning to ask, now that I have my Crack, what are some other god-tier combinations with this amp? I've got a Senny 6XX, AKG Sextett, and Beyer 880 600-ohm, and I love them all on this amp. I see the Vérité come up a lot, who knows if I'll ever be lucky enough to own one of them. 

So, beyond those four, what are some other famous pairings?


----------



## Dawgfish (Nov 20, 2022)

dstarr3 said:


> I've been meaning to ask, now that I have my Crack, what are some other god-tier combinations with this amp? I've got a Senny 6XX, AKG Sextett, and Beyer 880 600-ohm, and I love them all on this amp. I see the Vérité come up a lot, who knows if I'll ever be lucky enough to own one of them.
> 
> So, beyond those four, what are some other famous pairings?


Some other phones I find it be a great match with the Crack are Beyer T1.2,  Amiron Home, DT1990, HD600, HD660, HD58X, HD800, and all ZMF dynamic driver phones (Aeolus, Atrium, Atticus, Eikon, Auteur OG, and VO).


----------



## SHIMACM

bpiotrow13 said:


> Verite shines with tubes but You need to match the amplifier to You liking. I guess the amps You mentioned sounds differently. I have not heard BHC yet (it is on its way to me), but wa2 is very clear sounding, less tubey amp. I had it and sold it due to lack of charm.
> This does not mean it is not good, but really apms differ and You need to choose the one You like.



You say the Woo Wa2 is not a tubey amp?!

Everything I've read to date says just the opposite.

Can you explain better?


----------



## bpiotrow13

SHIMACM said:


> You say the Woo Wa2 is not a tubey amp?!
> 
> Everything I've read to date says just the opposite.
> 
> Can you explain better?


Remember everything is a bit subjective and You need to make Your own judgment.

For me wa2 is not tubey and i am not alone in this view. I even preferred wa3, which sounded nicer for me. If You compare wa2 to other woo amps it may be warmer (i used to have wa22 and wa6se as well), but woo amps are not particurarly warm.

See for example a review of La Figaro 339 and a brief comparison to wa2:

https://www.headfonia.com/lafigaro-339-my-fav-otl-amp/

I think it captures it well. I used to have La figaro 339 and loved it. If You are looking for warm but technically good sound this is it.

Feliks Elise is said to be tubey (i have not heard it) as is BHC without speedball (i will have it shortly).

Try really to listen Yourself at least one or two amps and check for comparisons to other amps so that You could have a view as to where they are against Your preferences.


----------



## pravous

dstarr3 said:


> I've been meaning to ask, now that I have my Crack, what are some other god-tier combinations with this amp? I've got a Senny 6XX, AKG Sextett, and Beyer 880 600-ohm, and I love them all on this amp. I see the Vérité come up a lot, who knows if I'll ever be lucky enough to own one of them.
> 
> So, beyond those four, what are some other famous pairings?


The ZMF Atrium is amazing with the BHC speedball imo.


----------



## bpiotrow13 (Nov 20, 2022)

pravous said:


> The ZMF Atrium is amazing with the BHC speedball imo


And how does BHC with speedball compare to Airmid?


----------



## pravous

For the most part I run the same tube rolls in both the Airmid/BHC speedball.    6as7g/6j5.  Airmid has a larger stage, better seperation/imaging and extends deeper than the BHC.  Not surprising given the differences in cost, size, power supply and components.  I consider them in the same 6as7g OTL family.  The difference between a great top of the line tube and an average one are greater in the BHC than the Airmid.  That being said, if I like a roll on the Airmid I like that combination on the BHC and vice versa.  I still use the crack with the 6xx daily in my workshop.   Long term I plan on making a new larger top plate and frame and converting to dual octal inputs so I can run the crack with 6j5, 6c5, 7193 inputs with out adaptors.


----------



## bpiotrow13

pravous said:


> if I like a roll on the Airmid I like that combination on the BHC and vice versa


Interesting, thanks. So apart from the obvious difference in technicalities they are close in terms of sound temperature/ tone (cold/warm)?


----------



## SHIMACM

dstarr3 said:


> I've been meaning to ask, now that I have my Crack, what are some other god-tier combinations with this amp? I've got a Senny 6XX, AKG Sextett, and Beyer 880 600-ohm, and I love them all on this amp. I see the Vérité come up a lot, who knows if I'll ever be lucky enough to own one of them.
> 
> So, beyond those four, what are some other famous pairings?



All three of my high impedance headphones (VO, HD800s and HD650) pair perfectly with my Crack w/speedball. But I have to use the right combination of valves for each of them.


----------



## Galapac

Bottlehead Black Friday sale.

Black Friday/Cyber Monday​all available kits 15% off​Friday, November 25th​and Monday, November 28th​


----------



## bagwell359

SHIMACM said:


> All three of my high impedance headphones (VO, HD800s and HD650) pair perfectly with my Crack w/speedball. But I have to use the right combination of valves for each of them.


Interesting.  Please share.  I'm kind of locked in on mine (E80CC needs Speedball and resistor change - but whoa the sound).

Speaking of which - lots of people use input tubes that don't fit in order to get more choices/better sound.

What about the cathode follower?  The ones with the big reputations are like hens teeth.  Any alternates?  Anybody?


----------



## SHIMACM

bagwell359 said:


> Interesting.  Please share.  I'm kind of locked in on mine (E80CC needs Speedball and resistor change - but whoa the sound).
> 
> Speaking of which - lots of people use input tubes that don't fit in order to get more choices/better sound.
> 
> What about the cathode follower?  The ones with the big reputations are like hens teeth.  Any alternates?  Anybody?



Well.

There are many good combinations.

But I can mention a few here.

Some combinations sound good with all three headphones like:

GEC 6as7g/GEC L63; WE421a or Ts5998/Foton or Melz 1578; GEC 6as7g/Tung-Sol 6j5gt; TS 5998/Brimar 6sn7gt; Chatham 6as7g/TS 6f8g.


----------



## bpiotrow13

SHIMACM said:


> Some combinations sound good with all three headphones like:
> 
> GEC 6as7g/GEC L63; WE421a or Ts5998/Foton or Melz 1578; GEC 6as7g/Tung-Sol 6j5gt; TS 5998/Brimar 6sn7gt; Chatham 6as7g/TS 6f8g.


Wow, some of those combinations are worth much more than the amplifier

What adapters do You use?


----------



## CaptainFantastic

bpiotrow13 said:


> Wow, some of those combinations are worth much more than the amplifier
> 
> What adapters do You use?



Sorry to drop into the conversation like this, but just to say that in Europe Deyan's adapters are definitely worth looking into. Drop him a note here on Head-Fi. I have several from him... 6J5 to 6SN7, 12AU7 to 6SN7 and E88CC to 6SN7 (since my BHC is built for 6SN7). I especially like the rotation on the 6J5 adapter which allows me to clear the volume knob nicely.


----------



## bagwell359

Thanks folks.  But I was looking for a 6080 replacement - I have the 6as7g.  I was looking for a different type that needs an adaptor that is sonically as good or better than unobtanium stuff like 421's.  My E80CC lays waste to the 12AU7 and plug in variants IMO and it costs less than a lot of the sainted tubes of that type. Hoping for the same for the cathode follower.  Haven't seen any suggested so it might be a pipe dream.


----------



## steve468

bagwell359 said:


> Thanks folks.  But I was looking for a 6080 replacement - I have the 6as7g.  I was looking for a different type that needs an adaptor that is sonically as good or better than unobtanium stuff like 421's.  My E80CC lays waste to the 12AU7 and plug in variants IMO and it costs less than a lot of the sainted tubes of that type. Hoping for the same for the cathode follower.  Haven't seen any suggested so it might be a pipe dream.


Google 6BL7 - although I personally haven't used it, a couple plugged into an adapter in the 6080 spot is supposed to compare favourably to a 5998. It apparently lowers the output impedance in a similar way. There's probably some info in the thread even.


----------



## bagwell359

steve468 said:


> Google 6BL7 - although I personally haven't used it, a couple plugged into an adapter in the 6080 spot is supposed to compare favourably to a 5998. It apparently lowers the output impedance in a similar way. There's probably some info in the thread even.


Excellent!  Thank you.


----------



## bpiotrow13

CaptainFantastic said:


> Sorry to drop into the conversation like this, but just to say that in Europe Deyan's adapters are definitely worth looking into. Drop him a note here on Head-Fi. I have several from him... 6J5 to 6SN7, 12AU7 to 6SN7 and E88CC to 6SN7 (since my BHC is built for 6SN7). I especially like the rotation on the 6J5 adapter which allows me to clear the volume knob nicely.


Thanks, I have heard many good things about those adapters, but I would try to avoid adapters first. I have TS5998 and Brimar 12au7 for BHC waiting. It is only that my BHS seems to stuck with the customs... Welcome to EU


----------



## JamieMcC

bagwell359 said:


> Thanks folks.  But I was looking for a 6080 replacement - I have the 6as7g.  I was looking for a different type that needs an adaptor that is sonically as good or better than unobtanium stuff like 421's.  My E80CC lays waste to the 12AU7 and plug in variants IMO and it costs less than a lot of the sainted tubes of that type. Hoping for the same for the cathode follower.  Haven't seen any suggested so it might be a pipe dream.



Get the speedball in and do the resistor mod with toggle switch the mod only cost about the same as a coffee to implement and the E80cc will sound even better running on the correct voltage.


----------



## RD777

I've been waiting for the black Friday sale to pull the trigger, however, I'm still not entirely sure as to whether I should go with the Crack (speedball)   VS C2a (w/o upgrades). I cannot find a lot of information on the c2a, and even though doc B lists it as an upgrade its still a little nebulous how big of an upgrade it is.

Most folk, seem to go crack + speedball into mainline. But direct comparisons between c2a and crack seem scarce.  

At the moment, Im looking exclusively at the crack or c2a to pair them with ZMF Aeolus. (currently using a schiit stack and a dark voice)

I was also considering a tor audio Roger for example.

Anyone got any advice?


----------



## cats4cans

RD777 said:


> I've been waiting for the black Friday sale to pull the trigger, however, I'm still not entirely sure as to whether I should go with the Crack (speedball)   VS C2a (w/o upgrades). I cannot find a lot of information on the c2a, and even though doc B lists it as an upgrade its still a little nebulous how big of an upgrade it is.
> 
> Most folk, seem to go crack + speedball into mainline. But direct comparisons between c2a and crack seem scarce.
> 
> ...


Buy 2 kits, one with, one without. Keep the one you like better. Sell the other one. I’m leaning toward going that way myself. From what I’ve read without should be more “tubey”.

Im also thinking about building it with a socket for a 6SN7 instead of using an adapter later. I’m sure it’s been done, but I need to research it a little.


----------



## raindownthunda

RD777 said:


> I've been waiting for the black Friday sale to pull the trigger, however, I'm still not entirely sure as to whether I should go with the Crack (speedball)   VS C2a (w/o upgrades). I cannot find a lot of information on the c2a, and even though doc B lists it as an upgrade its still a little nebulous how big of an upgrade it is.
> 
> Most folk, seem to go crack + speedball into mainline. But direct comparisons between c2a and crack seem scarce.
> 
> ...


I don't have experience with C2A, but you cannot go wrong with the Crack + SB with your ZMF Aeolus. I've been using mine with my Aeolus and VC going on 3 years now and still loving it - no regrets. IIRC the C2A is an improved version of the crack circuit while the mainline is a different topology/sound altogether. Hopefully others can comment on sound difference between the two cracks. If you could swing it, you could build both, decide for yourself, and sell the other one. Lots of people want to try these amps but don't want to or can't diy build.


----------



## steve468

RD777 said:


> I've been waiting for the black Friday sale to pull the trigger, however, I'm still not entirely sure as to whether I should go with the Crack (speedball)   VS C2a (w/o upgrades). I cannot find a lot of information on the c2a, and even though doc B lists it as an upgrade its still a little nebulous how big of an upgrade it is.
> 
> Most folk, seem to go crack + speedball into mainline. But direct comparisons between c2a and crack seem scarce.
> 
> ...


I've had both the Crack w/Speedball and currently have the Crackatwoa. If you've never had either, my recommendation is to start with base Crack, then go from there. I had never soldered before (or done anything handy at all, really), so it was definitely a learning process. The kits get harder as you move up.

But even just as a journey of learning what it is you like about the circuit, whether it's the junk food yummy bass of the base kit, or the texture and clarity of the Crackatwoa, you'll only know if you try them all.


----------



## LobalWarming

steve468 said:


> Google 6BL7 - although I personally haven't used it, a couple plugged into an adapter in the 6080 spot is supposed to compare favourably to a 5998. It apparently lowers the output impedance in a similar way. There's probably some info in the thread even.


6BX7 is even better. A single 6BX7 has higher output impedance than a 6AS7, and bass definition can suffer a little - but the overall presentation is more enjoyable to me than any 6AS7/6080 that doesn't cost $500 per bulb. Uncertain if the Crack trafo can support a pair of 6BX7s (3A total - 1.5A per tube). A pair has lower output impedance than 6AS7/6080.

I find most 6AS7s a bit dull and most 6080s too harsh and pushy. 6BX7 is my Goldilocks. It's just right. 

A TS 7236 is the E80CC of the 6080 AC motor regulator tubes - that was the design purpose of that family. They are a bit leaner than 5998 and many times cheaper which makes them much, much better.


----------



## RD777

steve468 said:


> I've had both the Crack w/Speedball and currently have the Crackatwoa. If you've never had either, my recommendation is to start with base Crack, then go from there. I had never soldered before (or done anything handy at all, really), so it was definitely a learning process. The kits get harder as you move up.
> 
> But even just as a journey of learning what it is you like about the circuit, whether it's the junk food yummy bass of the base kit, or the texture and clarity of the Crackatwoa, you'll only know if you try them all.


Thanks for the info! I'm not too concerned about the difficulty of the build (famous last words maybe...), but starting with the Crack would make sense.

In your experience, is the sound difference notable between the crackatwoa and crack + speedball?


----------



## steve468

RD777 said:


> Thanks for the info! I'm not too concerned about the difficulty of the build (famous last words maybe...), but starting with the Crack would make sense.
> 
> In your experience, is the sound difference notable between the crackatwoa and crack + speedball?


In my opinion, yes. Each step along the path is another layer of proverbial grime wiped off the music. The Crackatwoa has a better transformer and more noise rejection, which allows for a blacker background. The music is tighter and clearer. Now, whether that’s a good thing is personal.


----------



## bagwell359

JamieMcC said:


> Get the speedball in and do the resistor mod with toggle switch the mod only cost about the same as a coffee to implement and the E80cc will sound even better running on the correct voltage.


I have that mod and it works great.


----------



## bagwell359

bagwell359 said:


> Excellent!  Thank you.





steve468 said:


> Google 6BL7 - although I personally haven't used it, a couple plugged into an adapter in the 6080 spot is supposed to compare favourably to a 5998. It apparently lowers the output impedance in a similar way. There's probably some info in the thread even.


Promising but not at all a match with the E80CC which I'm never giving up.  So it's back to the domino plate Tung Sol 5998 - which one is for sale outside of US right here on HF.


----------



## Dawgfish

The TS 5998 is one of my favorites for the BHC.


----------



## steve468

bagwell359 said:


> Promising but not at all a match with the E80CC which I'm never giving up.  So it's back to the domino plate Tung Sol 5998 - which one is for sale outside of US right here on HF.


I'm curious what you saw that said the tubes don't match. Do the tubes' characteristics take the circuit too far off it's operating point? Does the mod to use the E80CC make the 6BL7 not work properly?


----------



## bagwell359 (Nov 25, 2022)

steve468 said:


> I'm curious what you saw that said the tubes don't match. Do the tubes' characteristics take the circuit too far off it's operating point? Does the mod to use the E80CC make the 6BL7 not work properly?


edited for clarity: Both of those tubes require the Speedball mod for best results - in fact I wouldn't use either without it.

Within that the resistor mod for the E80CC is 470 Ω, and the 6BL7 is 115 (or near that).  Also a 6BL7 pair uses more power from the transformer than its spec'd for which could be an immediate issue for transformers near the edge, or long term issues later.

The correct pairing for best sonics would appear to be the 5998/421/2399 and either the E80CC (aka 6085) Tungsram best, Amperex also very good OR 6SN7.

One note on the E80CC it is more accurate with less HD than the 12AU7.  I very much prefer the lively much more defined E80CC than the soporific HD drenched 12AU7. You would still never confuse the E80CC with an SS amp - more like a hybrid.  The gain is higher so you can't use it IMO with the stock volume pot - you'll get the channel mistracking fighting very high gain at low settings.

The 6SN7 doesn't need the resistor mod just an adaptor.  I reckon after I get the 5998 I'll have to try the 6SN7.  With the 6SN7 the 6BL7 appears to be a good match (but more research needed to be sure).

BTW, verify for yourselves stuff I wrote here.  Don't just go by my reading of the net.  Only the E80CC and the 470 Ω resistor switch have I done myself - with a basic 6080.


----------



## steve468

bagwell359 said:


> edited for clarity: Both of those tubes require the Speedball mod for best results - in fact I wouldn't use either without it.
> 
> Within that the resistor mod for the E80CC is 470 Ω, and the 6BL7 is 115 (or near that).  Also a 6BL7 pair uses more power from the transformer than its spec'd for which could be an immediate issue for transformers near the edge, or long term issues later.
> 
> ...


Thanks for that. I do remember that there's some great discussion of 6BL7 compatibility on the Bottlehead forums, from the main guys themselves (who are INCREDIBLY helpful, and know that circuit inside and out). I reread that after I asked that question, and their recommendations basically mimic yours. In essence - be careful with anything not stock!


----------



## GPJ7 (Nov 28, 2022)

.....................................


----------



## bpiotrow13

And the new story begins it has just arrived


----------



## bagwell359 (Nov 27, 2022)

GPJ7 said:


> FTR, today I soldered in some sockets on the speedball boards that allow me to easily plug in or unplug resistors from R1 on the small boards (old Speedball). Three different resistance values are used to run E80CC (470 ohm), 12BH7A (113 ohm), and 12AU7/6SN7 (235 ohm). I didn't have the exact values and so used a combination of 470 and 150 ohm resistors. I came across this socket method using a Vista Audio phono preamp and it worked great. Anyway, just wanted to provide an alternate method of dealing with these resistors. The transistors were changed to more robust ON MJE5731AG for use with 12BH7A.
> 
> https://www.amazon.com/dp/B01MTGHZMB?psc=1&ref=ppx_yo2ov_dt_b_product_details


Yes.  Switches esp little ones to fit near the board are going to require turning the amp over to switch or wired to a spot where you can flick them easily. 

I had a PS pre amp where you could change the resistor value for the cartridge gain.  Very easy to use and needed for all MC and some MM cartridges.  Thanks for reminding me.

Formula to combine resistors:

Parallel:

Rtot = R1 x R2 / R1 + R2

So your combo is 113.7 if the resistors have 0 error.  That's right there.

Series:

Rtot = R1 + R2


----------



## GPJ7 (Nov 28, 2022)

.........................


----------



## bagwell359

GPJ7 said:


> Digikey has a nice resistor calculator for series and parallel:
> 
> https://www.digikey.com/en/resource...rsion-calculator-parallel-and-series-resistor


Nice, but there are ones that just give the results without the commercial angle.


----------



## GPJ7 (Nov 28, 2022)

.............................


----------



## bpiotrow13

Work in progress





I am satisfied with the result (especially given i am not a technically skilled person), though painting the transformer end bell is a bit challenging. I have ordered the black one


----------



## jonathan c

bpiotrow13 said:


> Work in progress
> 
> 
> 
> I am satisfied with the result (especially given i am not a technically skilled person), though painting the transformer end bell is a bit challenging. I have ordered the black one


Now that is a transparent amp! 😉


----------



## bpiotrow13

jonathan c said:


> Now that is a transparent amp!



Ha, ha i have always hated transparent sounding amps. I need to finish this BHC so that it is not so transparent


----------



## LCMusicLover

carlman14 said:


> Alright everyone, I have the next big modification to my franken-crack ready. Meet the tube-rectified bottlehead crack! I completely re-implemented the power supply with an oversized power transformer capable of supporting a tube rectifier. The high-voltage winding is maida-regulated for a consistent, stable, low-ripple B+ voltage no matter what rectifier is plugged in. Any 5V rectifier is supported. I've tried 5U4G, 5U4GB, 5AR4, and 596 rectifiers with great success.
> 
> One neat thing here is that if I wanted to go back to SS rectification, I can! I have a SS plug-in rectifier that fits in the octal socket. This was tons of fun, and I learned a lot about power supply design in the process!
> 
> ...





carlman14 said:


> The regulated PSU definitely made the biggest change out of all the upgrades (aside from the speedball). Early impressions are that the sound is just flat-out cleaner and more resolving, and the bass is more defined and punchier.
> .
> .
> .
> Thanks! I like having ultimate flexibility of either tube or SS rectification.





carlman14 said:


> The impedance of the Rad0 is only 29 ohms, so this amp is a bad pairing. This amp is more suited for high impedance headphones like Sennheiser and ZMF (200-300 ohm or above headphones).


I bought this amp — using w/ ZMF Auteur & Atrium, as well as 6XX. Definitely good synergy w/ ZMF — haven’t tried 6XX yet as I just picked the amp up yesterday.

Funny part is how I fell into this amp — was hoping to do a try-out and someone posted a link to the listing — didn’t realize the seller was (relatively) local until we chatted.

So now I need power tube recommendations (already have lots of input tube choices) to synergize best w/ my ZMFs. My initial read suggests that Tung Sol 5998s are the ‘cream of the crop’. Concur/disagree? Any other recs — I’m looking for ‘max disciplined tubiness’ if that makes sense.

And I wouldn’t _mind_ spending less than the ~$250 a TS 5998 will end up costing.


----------



## carlman14

LCMusicLover said:


> I bought this amp — using w/ ZMF Auteur & Atrium, as well as 6XX. Definitely good synergy w/ ZMF — haven’t tried 6XX yet as I just picked the amp up yesterday.
> 
> Funny part is how I fell into this amp — was hoping to do a try-out and someone posted a link to the listing — didn’t realize the seller was (relatively) local until we chatted.
> 
> ...



A personal favorite of mine is the Chatham 6AS7G. That tube basically never left my BHC. They are less pricey than the 5998s, but still up there. Unlike the 5998s though... the Chatham 6AS7G can be periodically found for much cheaper. I got all of mine for $25-$30 per tube just by being a little patient and waiting for the right deal to pop up.


----------



## Dawgfish (Dec 4, 2022)

LCMusicLover said:


> I bought this amp — using w/ ZMF Auteur & Atrium, as well as 6XX. Definitely good synergy w/ ZMF — haven’t tried 6XX yet as I just picked the amp up yesterday.
> 
> Funny part is how I fell into this amp — was hoping to do a try-out and someone posted a link to the listing — didn’t realize the seller was (relatively) local until we chatted.
> 
> ...


The TS5998 is a good one though I wouldn't necessarily describe it as lush and tubey.  It's actually quite extended in the highs.  It is a great power tube however.  What really impresses me the most about it is the size of the soundstage and holographic nature of it.  If you are patient you can find one below $250.  I think I paid $150 for mine and it measured NOS.

Other power tubes I really enjoy with the BHC are the Chatham 6AS7, Wing C 6H5C, Tung Sol 6AS7, and RCA Black Plate 6AS7.  The Chatham and Tung Sol 6AS7s (early production were two different tubes until Tung Sol bought Chatham and produced tubes for both labels later on) can be pricey though not as bad as the 5998s (typically around $100-150 per tube).

The Wing C 6H5C and RCA Black Plate 6AS7 are the best bang for the buck IMHO.  You can find the 6H5C from AliExpress:  https://www.aliexpress.com/item/32809963593.html
I purchased mine from them and its an excellent tube though its took about a month to receive it.  It has great tonality though its not quite a holographic as some of the others.

To me its hard to go wrong with a RCA Black Plate 6AS7.  Its a great sounding tube and can be regularly bought for around $50-60 apiece.  Imho anyone with an amp using 6080/6AS7/5998 type power tubes should have a few of these since they offer great sound and don't break the bank.


----------



## Dawgfish

carlman14 said:


> A personal favorite of mine is the Chatham 6AS7G. That tube basically never left my BHC. They are less pricey than the 5998s, but still up there. Unlike the 5998s though... the Chatham 6AS7G can be periodically found for much cheaper. I got all of mine for $25-$30 per tube just by being a little patient and waiting for the right deal to pop up.


You got a great deal on those Chatham 6AS7s!  Congrats on that!  I paid $100 for mine and its worth it imho.


----------



## pravous

I bought this amp — using w/ ZMF Auteur & Atrium, as well as 6XX. Definitely good synergy w/ ZMF — haven’t tried 6XX yet as I just picked the amp up yesterday.


LCMusicLover said:


> Funny part is how I fell into this amp — was hoping to do a try-out and someone posted a link to the listing — didn’t realize the seller was (relatively) local until we chatted.
> 
> So now I need power tube recommendations (already have lots of input tube choices) to synergize best w/ my ZMFs. My initial read suggests that Tung Sol 5998s are the ‘cream of the crop’. Concur/disagree? Any other recs — I’m looking for ‘max disciplined tubiness’ if that makes sense.
> 
> And I wouldn’t _mind_ spending less than the ~$250 a TS 5998 will end up costing.


Tung Sol or Cetron 7236 is another power tube to try.  Not quite as sought after as the 5998 but I would say they deliver on the discipline criteria you asked for.   Cream of the crop would be GEC 6as7g/a1834, Bendix 6080wb and Tung Sol/Chatham 5998 but they are priced accordingly.  If you look up the Bottlehead Crack tube rolling thread there are some posts that rank the power tubes.


----------



## steve468

Another alternative to the 5998 that’s often mentioned is the Tung Sol (and later Cetron) 7236. Similar in sound if a little more solid state sounding. Can be found quite a bit more widely and cheaply. But count me as someone who would take the Chatham/TS 6as7g and the Russians before the 5998.

Another for “max discipline tubiness”  is a GEC (NOT GE) 6080. Langrex had a bunch, hope they still do. That’s probably the perfect description for that tube. Pricey but still less than 5998 prices.


----------



## steve468

pravous said:


> I bought this amp — using w/ ZMF Auteur & Atrium, as well as 6XX. Definitely good synergy w/ ZMF — haven’t tried 6XX yet as I just picked the amp up yesterday.
> 
> Tung Sol or Cetron 7236 is another power tube to try.  Not quite as sought after as the 5998 but I would say they deliver on the discipline criteria you asked for.   Cream of the crop would be GEC 6as7g/a1834, Bendix 6080wb and Tung Sol/Chatham 5998 but they are priced accordingly.  If you look up the Bottlehead Crack tube rolling thread there are some posts that rank the power tubes.


Ah! Beat me to it by milliseconds. You must have faster internet than me


----------



## LCMusicLover

carlman14 said:


> A personal favorite of mine is the Chatham 6AS7G. That tube basically never left my BHC. They are less pricey than the 5998s, but still up there. Unlike the 5998s though... the Chatham 6AS7G can be periodically found for much cheaper. I got all of mine for $25-$30 per tube just by being a little patient and waiting for the right deal to pop up.


Are 6AS7G & 6AS7GA the same? The way tube designations work is … inscrutable.


----------



## caracara08

Can I get some tube upgrade recommendations that won’t kill my wallet?


----------



## Dawgfish

LCMusicLover said:


> Are 6AS7G & 6AS7GA the same? The way tube designations work is … inscrutable.


Pretty much the same.  Your good.


----------



## Dawgfish

caracara08 said:


> Can I get some tube upgrade recommendations that won’t kill my wallet?


RCA 6AS7 black plates and early 70s Russian 6H5Cs for power tubes.  RCA clear top 12AU7s for input tubes.


----------



## LCMusicLover

pravous said:


> …If you look up the Bottlehead Crack tube rolling thread there are some posts that rank the power tubes.


If only I could find that thread. Not on Head-fi?

Pointer please … pretty please


----------



## pravous

On the Bottlehead forums.  
Rolling thread


----------



## dstarr3

Dawgfish said:


> RCA 6AS7 black plates and early 70s Russian 6H5Cs for power tubes.  RCA clear top 12AU7s for input tubes.


I'm running the RCA 6AS7 black plate / 12AU7 clear top combo and I have to agree, it's tremendous. The tubes the Crack ships with are fine, but yeah, these are a huge upgrade. I got a strong matched pair of each for $80 total, so I'm set for life. You can probably get one of each for under $50 total easy. Huge value.


----------



## Dawgfish

dstarr3 said:


> I'm running the RCA 6AS7 black plate / 12AU7 clear top combo and I have to agree, it's tremendous. The tubes the Crack ships with are fine, but yeah, these are a huge upgrade. I got a strong matched pair of each for $80 total, so I'm set for life. You can probably get one of each for under $50 total easy. Huge value.


Agreed!  I think it may be the best value combination for the BHC or at least right up there.  I honestly think I paid around $50 for both combined.  Like you said huge value!


----------



## whirlwind

carlman14 said:


> A personal favorite of mine is the Chatham 6AS7G. That tube basically never left my BHC. They are less pricey than the 5998s, but still up there. Unlike the 5998s though... the Chatham 6AS7G can be periodically found for much cheaper. I got all of mine for $25-$30 per tube just by being a little patient and waiting for the right deal to pop up.



Years ago I use to buy the Chatham 6AS7G from Leeds Radio and I found them through Etsy.  I think they were around $50 for a pair!


----------



## bpiotrow13 (Dec 14, 2022)

I could not resist inserting the tubes before soldering to check the look.






I had some problems with painting the transformer bell (top cap) and ordered the new already painted one for eur 4. It matches perfectly.


----------



## Dawgfish

bpiotrow13 said:


> I could not resist inserting the tubes before soldering to check the look.
> 
> 
> 
> I had some problems with painting the transformer bell (top cap) and ordered the new already pained one for eur 4. It matches perfectly.


She's a beaut!  Looking forward to hearing your impressions.


----------



## moriez

caracara08 said:


> Can I get some tube upgrade recommendations that won’t kill my wallet?



If you want ''clean and fast'' shoot me a PM for Sylvania 7236. Off to the races with something like a HD650. Big fav after TS5998 and maybe GEC6080 when I owned the Crack.


----------



## Tom-s

I'm selling a build Bottlehead Crack with all sorts of upgrades:

But! It's with a 6SN7GT / VT231 or even ECC32 driver tube.

https://www.head-fi.org/classifieds/bottlehead-crack-6sn7-ecc32-6080-full-option-build.37743/


----------



## bpiotrow13

So it seems i have made it. Now i need to check if everything has been done properly, but the manual says i have completed the assembly





Having no soldering experience and very limited tech skills i must say everybody can assembly the crack

Can not wait to hear it


----------



## caracara08

bpiotrow13 said:


> So it seems i have made it. Now i need to check if everything has been done properly, but the manual says i have completed the assembly
> 
> 
> 
> ...


That’s awesome. Congrats!


----------



## bpiotrow13 (Dec 22, 2022)

Just had a short first listening to my crack. Stock tubes (pictured with changed power tube for next listening), hd650 and neko d100 dac. I can only say wow. Proud to assemble it entirely myself it really sounds very good and is dead silent.


----------

