# Aikido 24V headamp



## rodentmacbeastie

Has anyone built their 24V hybrid Aikido yet?


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## fran

I'm nearing completion of mine. Prolly be next week before its running I'd say. Easy enough build so far and the quality of the board is excellent.

 This is my second 24V aikido, the first one being a regular pre, ie not a headphone amp and I can say that the sonics are excellent. Well worth throwing a few nice caps into C1, C3 and C4 if you had something like blackgates. Wimas elsewhere.

 Fran


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## fran

The work for this is coming along nicely. I have the chassis done, PCB is mounted and the PS stuff is all done. I need to do the input/output wiring next and then she should be ready to rock.


 More in a day or 2

 Fran


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## fran

2 pics to show some progress:










 Fran


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## fierce_freak

I have one of these boards as well, and have made up a half-way complete bom for it. I'm really unsure of when I might get to it, though.

 -edit- I also have a s11 board I plan to use for it. I've got the resistors in my bom to put it at ~25.2v.


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## fran

OK, I did some more on this tonight and I have it up and running. The linestage part is AOK, but I have some DC (50mV and 30mV left and right) on the HP output. Have to go back and look at that (I emailed JB about it too).

 I used a 24V Tx into a tread regulator from tangent. What I did then was adjust it for the heaters to 25.2VDC. Then I put in an extra CRC filter (10uF motor run/15R/1500uF) for the B+ which drops the B+ rather nicely to 23.95VDC. By my reckoning there should be little enough drift from this once its settled in as all the DC comes from the tread first. The tread is only $17 for the kit, a no brainer if you didn't have something already to hand. The heatsink on it hardly gets warm.

 When I get the DC issue sorted out, I'll post the solution.

 Fran


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## fierce_freak

Awesome, fran. I look forward to hearing about your results.

 -edit- What value did you use for C7-C10?


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## fierce_freak

I'm going through my BOM and fleshing it out. It's essentially done, but upon looking for places to buy 6GM8's, I found how scarce they are. I guess I'll have to budget out enough cash for at least two sets of tubes...I'd hate to need to replace them a year or two down the road and not be able to find any. I've found them to range in price from $5-25, depending on which of the 3 places I found to have it in stock I'm looking at.

 Does anyone have any suggestion on a good source for these tubes?


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## fran

Fierce freak:

 C1 are those 2 metal PIO caps towards the back of the amp, 4uF ones and they are bypassed with 50000pF polystyrenes. I have tried those actual caps in my other aikido and they are indistinguishable from blackgate Ns.

 C4 is 3300uF nichicon VXm, C3 is 2.2uF PP and that is again bypassed a second time by one of TomBs russian PIO 0.22uf from my Max build.

 I used 1000uF nichicon UPW caps for C7-10, but I don't know how important that is (heater string).

 Radiodaze has those tubes and Jim McShane does too. Not that dear either.

 I connected in my K501s and it sounds pretty good. Never heard bass like it from 501s before! Very impressive. can't wait to get it inside to the main rig and see how it runs with the 650s and 701s and vs the max. Hurry up and build it! I think this amp could be a great amp.

 More on that DC offset later - but I think its all OK.

 Fran


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## fierce_freak

I figured out C1 and C3 after I posted. Thanks for the info, though 
	

	
	
		
		

		
			





 Glad to hear it's making music! I look forward to your impressions of it with the HD650s (what I currently have, though I plan to repurchase some RS-1s in the future). I've been really wanting to put this thing together for a long time, but funds just haven't been cooperative 
	

	
	
		
		

		
		
	


	




 Hopefully that'll be taken care of soon.

 What other nice amps have you heard?


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## fran

Yep, its definitely worth putting together.

 Other amps are Little Dot 2, LD MkIII, revmh millet, millet max, original master, DIY ECL82 amp - after that some portable stuff for on the go. Cans are HD650s, K501s and k701s, ER6i.

 I know its not an exhaustive list!

 On the DC offset issue: I think I was making a mountain out of a molehill in a way. Just like the millet, there is a DC offset at turn-on, which rapidly drops. With no headphones plugged in this remains about 20mV or so. Plug in some cans and it drops to zero right away. 

 I've spoke to John Broskie about this. His explanation is that:

_What happens is that the electrolytic capacitors leak a small current which against the 10k terminating resistor ends up equaling a fairly big voltage. But that same amount of current against 32 or 300 ohms makes for a 32/10k or 300/10k as much voltage offset._

 He talks about using a jack like some musicians use where when nothing is plugged in the tip and ring are shorted to ground. This would dissipate the DC quickly. He says that instead of using a short directly to ground to use say a 10R instead. 

 Of course you could just put in a e12 delay too.

 Overall the build was pretty easy. I recommend using the tread from tangent - it simplifies so much (or one of linear power one supplies off ebay). There are a good few parts to buy - it probably isn't the cheapest one to build, but it is good! BTW he recommends panasonic FM series for C4 bypassed with a polystyrene.


 Anyone else out there doing one of these? You get a full function preamp along with a headphone amp too. SQ from the pre is excellent - I can speak on this as this is the second one I've built and it will take on any comers. The headphone amp sounds great to my ears, but I would like a little more time to compare it to say, the max.


 Fran


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## fierce_freak

I hope it's clearly better than the Max. The Max is a good amp, but I prefer my B22 so hope that the Aikido can be on roughly the same level (I've heard a full voltage non-hybrid aikido headphone amp before, and it was killer).

 Thanks for the info on the DC offset 
	

	
	
		
		

		
		
	


	




 About the cap in the C4 position...I was planning on using an Elna Silmic II there, but perhaps I'll purchase some FM's as well, to test. I do plan to bypass C3 with a polystyrne (Multicap RTX), but are you saying that C3 itself should be polystyrene?

 -edit- forgot to ask, in C11 the lead-spacing is 10mm, correct?


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## fran

From his last email to me, yes it would seem that C3 should be polystyrene with FMs in the C4 position. He spec'd panansonic FM 25V 1800uF.

 Highs are excellent with the nichicon/PP/PIO combo that I used though.

 C11 - I'm not sure but 10mm sounds about right. I used a leftover nichicon cap from the max build and I think the leads might have been a shade close together so that the cap wouldn't sit right down on the PCB.

 I've used the e12 - and in fact I have a spare e12 kit in the workshop, but I'm reluctant to use it, just because I don't like relays in the signal path. Had a bad experience with them one time. (even though my max has one and my revMH too!)

 Fran


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## fierce_freak

Awesome, great info. Thanks, fran 
	

	
	
		
		

		
		
	


	




 I'm hoping to start ordering parts for this in the coming few weeks, so I should be able to update then. I've got everything picked out, minus an enclosure (and I'm wavering on the volume control).

 I look forward to hearing any further impressions you have, Fran. I have one last question for you (I hope ;D): next time you're doing some work on the amp, would you mind measuring the height of the populated board? I'm assuming the tubes are the tallest components and that the total height including board and standoffs might be ~75mm.


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## fran

I make it 72mm approx to the top of the tubes - thats with the board on 9mm/3/8" standoffs. And when I had to open, that C11 does look like 10mm lead spacing. I'm using a 35V1500uF nichicon (mouser # 647-UPW1V152MHD6) from the max BOM and I had to bend a lead to fit it in. I also dropped R17 to 5K to up the idle current and give a bit more gain. My heatsinks are the aavid thermalloy ones (mouser #532-513102B25). They don't hardly even get warm. He specifies a 1" hole spacing for the heatsinks, but those ones the pins are a shade to big and while they sit into the holes, they don't seat home fully. You will get away with it, they go in enough to solder them but just they don't sit down all the way.

 There is another thing you should really spring for. Its a LDR based volume control that a fella in australia sells as a kit. His site is SKA Audio and the kit is AUS$27(incl shipping). Beats the crap out of an alps blue. It'll run easily off the 24V aikido supply (you resize a resistor - tell him and he will include it for you). He calls it optivol. I don't think he has it listed on his site, but email him and he will get back to you. I'm going to replace the stepped one i have in my max with it and I've used it now in 2 preamps and it works perfectly.

 Original idea posted here:
diyaudio

 and ska audio forum:
optivol
 Fran

 Fran


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## fran

Listening impression with K701:

 Source: PC>>monica DAC>> either the aikido or millet max mosfet.

 The aikido gives a "fuller" sound - just a bigger richer sound. Put on your k701s with your max and put your hands over the cans and squash them into your head - putting the divers closer to your ears - thats kind of what its like. There seems to be a little more detail as well - cymbal/ hi-hat hits are a bit better defined and are a little more sparkly. No harshness or sibilance from either amp.

 Now the differences aren't huge, but if you were starting out and were thinking of building a lower voltage valve amp, this would be what I'd go for right now. You also get a full function linestage thrown in as well. 

 Having said all that the DC at start up issue does need to get sorted. I neglected to say that this only occurs on the headphone outputs, not the linestage outputs.

 If I get a chance later I'll repeat the exercise with the Hd650s. If I was to be asked for an explanation, I'd say that the aikido had more current available to effortlessly drive the k701s.

 Fran


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## fierce_freak

Thanks yet again, fran, very helpful.

 I don't even have R17 on my BOM...wonder how I missed that. I haven't seen any values for it suggested anywhere, either (nm, just saw it in the original article. no explanation, though). I guess 5k will do. What is the hole spacing on the heatsink you specify? Looks like ~0.75in. Since the 'sink's not getting warm, maybe I'll tweak R15 down a bit further to up the current.

 Thanks for the heads-up on the LDR based volume control. I was debating between three different options (JB's stepper, joshua tree attenuator, and TKD pot), but it looks like I'll have to read up on this one and possibly add it to the list for consideration (the TKD pot was in the lead).

 -edit- Just saw your impressions...looks nice! The max is a very good amp, and differences between it and higher end amps do tend to be a bit more on the subtle side, usually in refinement/smoothness as well as detail retrieval and tone.

 I look forward to your impressions with the HD650.


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## fran

I have a BOM for mouser, I don't how to get it to you, but I'm sure I could convert to excel or something of that makes life easier.

 Tellin' ya, get the optivol. Well worth it - you'll need a 1k8 resistor since you'll be running it off 24V rather than the designed for 30V. (It needs about 5.5V, and draws 13mA, so you can run it off pretty much any lower voltage supply just by changing the resistor using an online ohms law calculator). Heres a guarantee for you: If you don't like it, I'll swap it for a stepped pot that I bought from ebay. If you think thats generous, well think of it this way: I think its better than the stepped pot, so I have a useless stepped pot here - if you don't like the optivol I can only gain!

 Fran


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## fierce_freak

I've decided to give the optivol a shot, it's not very expensive. I've got the BOM more or less complete, but thank you for offering yours 
	

	
	
		
		

		
			





 I've also decided to use a tread and run it at ~25.2v. I'm a big fan of both the TKD pot and the Joshua Tree, but I like to try something new now and again 
	

	
	
		
		

		
		
	


	




.

 -edit- I'm going to use a 24VAC wallwart transformer to the TREAD. I'm trying to decide on a heatsink to use on the LM317, but I can't seem to find one that is large enough and will still fit to handle the heat (based on Tangents calculator). You said in an earlier post the heatsink on yours barely gets warm...are you using the recommended part or a different one?


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## fran

Get an extra couple of caps and set the tread to 25.2 and then use something like 10uF/15R/220uF for the B+. That'll give more filtering and drop it to 24V. Run the optivol off this supply. If you have a choke use that instead of the resistor.

 Fran


 EDIT: the heatsink I'm using is this one from mouser #532-513102B25 Its about 40mm high (1.5 inch) and one inch mounting spacing - which is what is specified in the literature. The cost between the different heights is small and even at 2" high they would still be lower than the tops of the tubes. Thats only an issue if you want the tops of the tubes to stick out the top of the case. But, yes, the 1.5" ones hardly get warm - I've had this here turned on playing all day and just opened the top just now to see and the heatsinks are just a little warmer than body temperature, wouldn't say more than 45 degC. As a whole this is not an amp that gets all that warm, even the tubes don't throw off that much heat (area over the heatsink is warmer than area over the tubes).

 To increase the idle current he told me to reduce R17, which was at 10K - so I just paralleled another 10k each side.

 BTW, there was an updated user manual for the 24V aikido on broskies site, its about 3 blogs back or so. Contains a good few more details that weren't included in the earlier one. Another thing: theres no R13 on the board and I think its R20 and 21 are the same value. 

 Further disclaimer: the max amp I comparing above has a stepped attenuator in it whereas the aikido has an optivol. that may make a difference to the sound too. Also, just in case someone thinks I'm a shill for ska audio, I have no connection with them only bought 2 optivols and think they're great, and in fact bought another 2 tonight for the aformentioned max and another preamp thats in the pipework.


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## fierce_freak

I figured I'd run the whole thing at 25.2 (JB said he'd tried a 25.6v supply and said it sounded slightly better), though I suppose the extra filtering could help.

 -edit- I took a look at your pics again. Do you have a part number for the heatsink used on the tread? That's the last piece for my BOM, then I'm ready to go.


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## fran

simultaneous posting: see the edit to my last post....


 Fran


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## fierce_freak

Just to be clear: You're using the same heatsink on the aikido and on the tread?

  Quote:


  Originally Posted by *fran* /img/forum/go_quote.gif 
_Further disclaimer: the max amp I comparing above has a stepped attenuator in it whereas the aikido has an optivol. that may make a difference to the sound too. Also, just in case someone thinks I'm a shill for ska audio, I have no connection with them only bought 2 optivols and think they're great, and in fact bought another 2 tonight for the aformentioned max and another preamp thats in the pipework._

 

I hope even after the optivol upgrade for the Max that the aikido will still be superior. I'd like it to be on par with a single-ended B22, but that could be asking a bit for only spending about $450 (what my BOM totals, including casing, wiring, etc.).


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## fran

The heatsink on my tread is actually a bit smaller - it was a spare I had in my parts stash. One of the same will do, but on the tread it hangs off the side of the PCB so you may need to cutoff the legs on the heatsink. The whole thing when running does not draw that much current, <500mA in total IIRC.

 $450 sounds dear, but I suppose when you add it all up....

 Fran


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## fierce_freak

Haha, that's what putting blackgates and multicap rtx caps in your BOM will do 
	

	
	
		
		

		
		
	


	




 I'm saving the boutique resistors for later...just using PRP for now.


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## fran

Actually the tread heatsink that I'm using right now gets a good bit hotter than the ones on the board - so just ordering another one like the others (that little bit bigger) would probably be a good thing. I might put a bigger one on mine. when you are putting the tread together, either premount the 317 on the heatsink and then solder it in, or else leave the legs on the 317 longish so that you can fold it back a bit to allow some clearance for the heatsink.

 Another thing. I plugged in some disposable 8 ohm headphones (from the 70's!) and turned on the amp from cold. Got essentially no DC surge even as the caps charged.

 I plugged in the HD650s and did the same. Voltage went up to about 1v for a second and then dropped rapidly. No damage to the cans.

 I'll try this with the k701 as well.

 I would really like to be able to leave the cans plugged in and not have to remember to unplug them each time. From that observation it would seem that while the DC offset does rise, it is at a low low current so it might not matter.

 Fran


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## fierce_freak

I'll probably add the resistor to short tip and ring to ground when there's no headphone plugged in.

 Have you had a chance to listen to the amp with the 650's? It sounds like it pairs very well with the K701's and the K501's.

 I'll be ordering the bulk of the parts on Monday, so hopefully I'll be able to start by next weekend. I should be able to finish the balanced B22 I'm working on this weekend, so my schedule will be more or less clear.


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## fierce_freak

Do you think I can use non-polar blackgates in the C4 position? I have polar blackgates in my BOM, but I'd prefer to use the NX series if it'd work. It seems to me you shouldn't need polarity in that position.


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## kvant

Quote:


  Originally Posted by *fierce_freak* /img/forum/go_quote.gif 
_Do you think I can use non-polar blackgates in the C4 position? I have polar blackgates in my BOM, but I'd prefer to use the NX series if it'd work. It seems to me you shouldn't need polarity in that position._

 

Polarity of electrolytic caps is more like a constraint than advantage or something you would need. Non-polars will do fine. For a practical proof check all those Millett hybrid builds with BG NX or Nichicon ES at the very same position.


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## fierce_freak

Great, thanks a lot kvant. It seemed logical that I could use a nonpolar there, but I wanted to make sure.

 -edit- Could the same be said for C11? It seems the same logic would roughly apply.


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## kvant

Quote:


  Originally Posted by *fierce_freak* /img/forum/go_quote.gif 
_-edit- Could the same be said for C11? It seems the same logic would roughly apply._

 

Yes, the same logic applies. It goes something like this: wherever a capacitor is needed, one is used. Sometimes such a large value is necessary that there is no other practical way than using electrolytic capacitor. These are, by design, usually polarized. In such a case one has to be careful about orientation, which is then indicated on a schematic. However, this indication does not mean that polarized capacitor was needed at the beginning, it just helps a builder not to mess it up.


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## fran

I _think_ non-polar is fine, just that the typical non-electrolytic cap is hard to get at the kinds of capacitance JB recommends. You're going to bypass with a non-polar anyway.

 Fran

 PS: on that tread heatsink, my smaller one does get pretty hot so I think I'm going to stick a bigger one on it when I have the case open again. I'd say its at maybe 70deg C - won't burn you but hot enough for to be uncomfortable to keep your finger on for say >20secs.


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## fran

Listening impressions with HD650:

 Again same setup as for my earlier comments with the k701, source is:

 PC>>monica 2>> either aikido or millet max mosfet>>HD650 rewired with SPC in teflon.
 The millet has a DACT type stepped attenuator, aikido has the optivol.


 Short version: more or less the same effects as with the k701.

 Longer version:


 I based my listening around a few tracks of different types of music. I use Pierre Bensusan - Altiplanos as a bass test. Track 3 on this has some really low bass in the background. I use a Buddy Holly track "True Love Ways" which has the most amazing soundstage ever (you should hear on my quads!). Donald Fagen - Kamakiriad track 5 "Tomorrows Girls" for PRAT and sharp transients. Little Pink Anderson - Carolina Bluesman has a great version of St. James Infirmary. Simple arrangement where you can hear the singer leaning from side to side as he sings. Likewise Muddy Waters - Folk Singer - almost any track. I find some of the stuff from DSOTM very good for detail - if you can clearly hear some of the dialogue in the background you have good resolution. Kings of Leon Aha Shake Heartbreak for some good rock and Bob Dylan - Oh Mercy for a heavy dense Daniel Lanois production that challenges.

 So what do I think;

 To be honest I think the aikido has more dynamic range, better presentation and a fuller more well rounded sound than the max. The max sounds a bit more spacey - which initially I thought might mean that it would soundstage a bit better than the aikido, but in reality what it really means is that it sounds more recessed while the aikido is more lively. It clearly has more resolution too - things like the background stuff in DSOTM is easier to decipher. You know those quieter spoken bits - everyone will hear the "short sharp shock" bit, but the other stuff in there that's quieter. I'm pretty useless at putting into words what I'm hearing, but the aikido also sounds more intimate. Again this goes back to the soundstage bit mentioned above. If a singer is close miked, it sounds really close to your ears. Initially this appears like the soundstage is small, but then you hear something that genuinely has been recorded with a big soundstage and you can hear that clearly. Drums come alive more too, the ring of drums is more dynamic and the thump of a kick drum is very real and alive.


 So that reads like I think the max is a POS. However that ain't the case. The max is a great amp and I think is one of the best offerings out there (and I own one and also a revMH millet too). But the aikido does better them. The aikido circuit is very clever, probably one of the best sounding ones out there. What I'm amazed at is the use of the LM317 in the output stage. I was pretty skeptical of this as JB had earlier talked about using a BUF634, but since they are unobtainium at the moment i thought the LM317 was just a stopgap. But no, they sound great.

 So heres the thing: Say you are on the lookout for an amp to build. If you go tube, you can go for a standard high voltage amp, you can go millet max or you can go aikido. The aikido I think will cost about the same to build as a max, but while JB is very helpful and will answer your emails, there is not the same level of support available to you as with the max. That thread is pretty extraordinary in the DIY world. So if you have say one or 2 builds under your belt, then the aikido is well worth a shot. The other thing is that you get a full preamp in the deal. I have mine set as I said above with 6 inputs. You could easily wire in a tape loop too if you wanted. It is a fairly big board so it does need a fairly big case. Think full width (430mm) and at least 75mm high, 100mm would make life easier for you. I make my own casework so its not that much of an issue for me, but compared to the standard hammond case for the max, it might be an issue for some. The other detail that needs to be fully sorted out is the startup DC offset. Certainly a e12 delay would sort that out and is most likely what I'll end up doing. You need to factor that in to the build cost when your at it.

 I hope that helps or gives some impression of how it sounds. I am looking forward to hearing what you think fierce freak. I am going to email JB with a link to this thread and see if any other who have bought the board and built it would be interested in posting some build info here.

 Fran


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## fierce_freak

Fantastic write-up, Fran. I also appreciate the detail you've gone into regarding support for build in case a newer builder is considering it.

 I've been wanting to put together some form of Aikido as headphone amp for a good while, especially after hearing looser101's awesome high voltage build last November (which I felt on par with a single-ended B22, perhaps beating it out slightly). I also want to get a pre-amp out of the deal, so this looks like a winner to me.

 The max certainly is a great amp (better than most commercial offerings I've heard). I'm glad to hear your impressions about the Aikido as they are though, as they seem to point to exactly to what I'd like improved/changed about the max's sound to bring it up to the next level.

 It's funny that you should mention it as a large amp. I suppose it is, but one of the reasons I'm excited about it is that it will be a down-size for me, in terms of size 
	

	
	
		
		

		
			





 I'm still looking at casing options, but that's something I'm going to leave open until after I've actually put the amp together. The three sizes I'm hovering between at the moment are 12x8x2 (tubes sticking out the top), 12x8x3 (if I decide to fit a hammond 159zc choke (60mH, 2a, 0.7dcr choke) in there), or 12x12x4 if I feel cramped (I don't want to go that large though, which is why I'm using a TREAD).

 Also, thanks Fran for pointing me to SKA. I might pick up a GB150S amp and supply in a few months as reviews look good compared to price.


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## fran

My case runs to about 430mm wide x 250mm deep x 150mm high. Basically it looks "tall". That's primarily though because I was using a recycled transformer which was way oversized and is the tallest thing in the box. On my other aikido I have the tubes sticking out of the top, but because of the heatsinks on this one they are enclosed.

 I too looked at the SKA mps too - but they work into large enough dough when you factor in the power supply and so on.

 have you seen the build thread on diyaudio for the naim clones on ebay at the moment? If I was to build a SS amp, I think thats where I'd go right now.

 Fran


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## fierce_freak

Yeah, with that transformer you'd definitely need to have a case of that size, though it would probably match well with the size of most commercial CD players.

 It is a decent amount of dough for the SKA amps, but it's still less than what I'd planned to do (B24 when amb has it ready for production), and you can get one (GB150S) in a pretty compact form if you're careful with layout. I'm not in a hurry to do it, but it's certainly something I'm looking forward to.

 I haven't been following anything over at diyaudio lately, except for the sabre dac which I'm looking forward to. I'll have to take a look, though.

 As far as my own setup, I'm at a bit of a crossroads. I finished up my balanced b22 today (also setup as pre). It's a fantastic amp, no question, and I don't really expect tubes running at such low voltage to necessarily quite match up (even with the clever aikido topology). There is a large part of me that would like to simplify my rig, though, and downsize, both in terms of space and in terms of cash output. Sure, when I say my BOM comes out to around $450, that might seem like a lot, but when the amp I finished today cost at least three times that, perspective changes. I'm strongly considering selling the just-completed amp...I don't think there's an amp better than it out there (maybe different, not better), but being on that leading edge makes me want to only stay there in every aspect of my system, and that takes cash to do, cash I'm not sure is worth it (for me). I think pulling back just a hair from that edge would put me where I want to be in regards to a system to live with.


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## fran

Whats the rest of your system fierce_freak? What speakers etc are you using? Can't that B22 be used as a power amp or am I dreaming that?

 Fran


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## fierce_freak

I have a nice twisted pear audio Opus DAC to the B22. I don't actually have a speaker setup, though I do have some Silver Iris drivers that I haven't made 'enclosures' for yet. The B22 can be used as a power amp if you build it with the proper heatsinking (this build actually started on proper heatsinks but changed into it's current form when I decided I'd like to try balanced again).


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## kvant

Just a little side note:

  Quote:


  Originally Posted by *fran* /img/forum/go_quote.gif 
_The other thing is that you get a full preamp in the deal [Aikido]_

 

Virtually every headphone amp can be used as a preamp. MAX too. After all, the title of the original Pete Millett's article was "Build a Low-Voltage Tube Hybrid Headphone/Line Amp".


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## fierce_freak

Yeah, this is true. I think the thing I like best about it is that there are seperate outputs for both built into the board. Sure, it's a small thing, but it's something I appreciate.


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## fierce_freak

I placed the order today for all the parts except tubes and case. I hope to order both next week.


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## fran

Thought I'd post a pic or 2 to let you see how it turned out. I ended up putting in a e12 delay for safety sake. Panasonic FM caps for c4 bypassed with 2.2uF and then further bypassed with the KY42 russian 0.22uF caps.

 Other than that its fairly standard stuff:














 Fran


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## fierce_freak

That's a beautiful case. I ordered the tubes last night, too, so all I have left to order is the case. Do you feel any differently about the amp now that you've had the chance to listen to it a bit more?

 -edit- What did you replace the TREAD with? I see it has rounded corners on the PCB, and I've only seen that from JB's stuff.


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## fran

What sharp eyes you have there!!

 Yes, JB was kind enough to send me a new PS PCB that he is trialling. I built it up and had to install it just to keep it all aikido!

 Beautiful PCB from him as always. It builds up very easy - the heatsink is a better one than on the tread, but it still is pretty hot. I don't know how good that gonna be long term. Its bigger than the tread too BTW.

 No, feel just the same about the amp. Excellent. 

 Oh yeah, I put in the panasonic FMs. No real difference - I didn't try bypassing it with other caps, just kept the ones I had in so it would seem like the bypass caps are all important here (C3).

 Fran


----------



## fierce_freak

That's awesome. It's a very nice looking board (like all of the stuff JB does). I imagine he'll blog about it when he gets around to it. Thanks again for the info


----------



## Budgie

Fran-Looking at your image- are those capacitors near top center in the image, with bypasses soldered to them? If so, those are pretty interesting! Any pictures of them?


----------



## fran

None up really close, but they are old PIO ones - 4uF 400V I think and the bypasses are some 50000pF polystyrene ones. I have tested out these caps (which were given to me) against some Blackgate N series and could not tell the difference between them.

 You see similar ones on ebay now and again. They are heavy, so if you buy from overseas the shipping will be high. Sound great though and are bullet proof. They are actually made with a flange so that they can be mounted the opposite way to the way I did it (mine are upside down) with the 2 terminals sticking into the case from outside (if you know what I mean!)

 kinda like this one:
http://www.machmat.com/sales/images2/2x4u600cd.jpg

 Fran


----------



## fran

Just to add that they do take up a fair bit of real estate!


----------



## Budgie

Sweet!
 If I may ask, how did you end up mounting them to the chassis? I have ran into problems mounting motor run type caps, and keep looking for an easy solution.


----------



## fran

Not to code I know, but they are stuck down with an industrial type double sided tape. I picked up a few rolls of this stuff one time and it has an incredible hold. Its think, about 1/8" or so and looks almost like a solid gel, i think its made for sticking pictures to a wall when you can't drill into it.

 There should be mounting brackets available for the motor run types. As you can see I've used one in this amp and I used a bracket to hold it (the cap was a salvage from a dead motor and the bracket came with it).

 Fran


----------



## headphonejunkie

How about grados. Has anyone listened with grados. I would love to hear how the aikido sounds with 225's.


----------



## Budgie

I guess it's just pure laziness that I haven't ordered the correct mounting rings for the oval caps. I can get the round brackets locally, but the oval type seem to be harder to find.


----------



## fran

Oval? i haven't seen them!

 Grados: sorry, i don't own any. Tried some SR80s one time and was less than impressed.


 I can only talk about using HD650, k501 and k701 unless someone want to send me a set of grados (GS1000 naturally 
	

	
	
		
		

		
			





)

 Fran

 Fran


----------



## headphonejunkie

RS1's would work too.


----------



## fierce_freak

Yeah, once I get the Aikido done, the RS-1 will be the next thing on my buy list (how I miss them!).


----------



## fault151

I have the dual mono boards. Got all the bits i need, just gotta put it together. 

 How does everyone else's sound?


----------



## fran

Very good, but I think the PCBs that myself and fierce freak have are the newer ones with the onboard headphone amp capability.

 You can still do the same thing with yours, you just need to either make your own PCB or wire it P2P. The schematic is on JBs website.

 If you are just going for a preamp without headphone bit, then fire right ahead. You will have a superb performing preamp.

 Fierce freak, did you have any problems getting some 6GM8's? I bought the last few from radio daze earlier in the week. Are these things scarce now i wonder?

 Fran


----------



## fierce_freak

That's the point I brought up earlier in this thread...6GM8's are starting to get a bit rough to source. I picked up some nice ones from tubeworld.com but they were expensive. I decided to just get the best I could given the limited supply, though, otherwise I'd be left wondering. It does make me worry about prospects of getting a replacement set when the ones I just ordered eventually need to be changed out. It would be great if one of the current production tube companies would start making some or a similar low voltage tube.

 Regarding the PS that you're testing, fran, is it more or less the same as the schematic JB put in the guide for the 24v aikido?


----------



## dBel84

6GM8's have become somewhat more popular, I recall a thread on DIY audio addressing this approx. a year ago - I thought "yeah right" as there were still a ton listed at various places. I was lucky enough 2 pick up 2 matched pairs of Bugle Boys back then for reasonable cost, and have a supplier for GE tubes at ~ $7 ( actually it's been a while since I inquired about stock) - they are really cool tubes and sound like the more robustly constructed tubes out there. 

 ps - great build Fran, glad to see that it all came together so well..dB

 edit = just noticed that is one in my avatar


----------



## fran

Yes, it is exactly the same as the one in the PDF booklet. Parts are all pretty simple, mur4100 for the main rectification (+ bypass caps), 1n4007 for D5 and D6, LM317 or equivalent, 2 resistors for the voltage divider part of the LM317 and a few caps. 2 higher uF, 2 lower uF.

 The same board can be configured to give 1.414 time the AC minus the dropout or 2.3 times the AC minus dropout. I think you could use a 12VAC Tx with this board to give you the required 24V. Didn't test that though.

 I switched to a 1 1/2" aavid heatsink on the LM317 and it does get hot. I'm still wondering should I get a taller one. I must rig up the temp sensor on my DMM and get a reading, but you wouldn't hold your hand on it for long. Its the only thing left that concerns me.

 I bought 8 6gm8 from radio daze at 5.25 ea. I haven't started to look elsewhere for more yet. Thats 4 thats in each pre and 4 each for spare which should last a looooong time indeed.



 Fran


----------



## fierce_freak

Once I've gotten used to the sound I get from the 24v Aikido, I think I may pick up some jisbos buffers to use in place of the LM317's and also pick up another tread to run the whole thing at +-12.6v. Of course, that's a bit down the road, but I wanted to mention it to see thoughts on it.


----------



## fran

I think you can jumper the heaters to run them at 12.6V, but AFAIK the B+ is at ~24. You could separate both of those out if you wanted.

 I have a doubt about my LM317. I can't now remember whether its the 500mA or higher version. If its the 500mA one then it'll be operating pretty close to its max current. Gonna have to try and get the 1.5A one, or even a LM350 maybe. That might be why its getting hot.

 EDIT: Just had a look and I bought the LM317T which says on the web page that its 500mA but when you look up the data sheet from ST says its good for over 1.5A - and OK to 125 deg C so maybe it'll OK. I really need to get a temp for that heatsink! 

 Fran


----------



## fierce_freak

I think if you ran the heaters in series from +12.6v to -12.6v you'll still end up with a difference of 25.2v, so no change in heater wiring.

 Which LM317 variant came with your TREAD? I should have the tread pretty soon, but it'll probably be later this week before I start receiving the other parts. Of course, the input jack for my AC wallwart was backordered, so I'll have to come up with a hack until I get that towards the end of this month.


----------



## fran

Don't know about the tread LM317 - I'll look it up later for you. 

 I may have been worrying needlessly about the LM317 temp though - I put the meter on the heatsink right at the LM317 this evening and it was only at 57 deg C - the outside edge of the heatsink was a little hotter at 61-62 deg C. That would seem fairly OK to me.

 Fran


----------



## fran

The one in my tread is a LM317AT which is listed as the same as LM317T, which is 1.5A apparently.

 Fran


----------



## fierce_freak

Cool, thanks fran. I got my first two shipments of stuff today, but none of it is anything substantial. I hope to have the rest by next weekend (minus the case and the ac jack).


----------



## fierce_freak

I got pretty much everything in today minus hookup wire, tube sockets, and the caps for C2, so I hope to do a little bit of work on it tonight or tomorrow. This should be a pretty quick project to get going as I'm not casing at the moment, which saves what is always the biggest headache of a project for me, at least for now. I'm only holding off on casing as I have evil plans of balancing the amp in my head...if I prefer the aikido to my unbalanced beta22, then I'll build a second aikido and pair them together for balanced (though getting tubes that match with the original four will be hell...should tubes match across the board?).

 For C2, I ordered both Silver Mica 200pF and some polystyrene 200pF caps...any idea which will be better? This just forms the low-pass filter, correct?


----------



## fran

I used 330pF wima fkp - because I had a bag of them. I can't remember what he says about the value range, but the 330 must have been ok. I think the C2 and R20 make the low pass filter just before the LM317 section IIRC. 

 ....went off and checked it up. with R20 at 10K 330pF gives a cut off at 48.2kHz. with 200pF its a 79.6kHz. Broskie says to use 100-300pF. 

 These are fairly small caps - tell you what you could do if you think you want to vary the sound a bit - solder in some sockets and that way you can swap 'em out at will. You can usually salvage them off old PCBs if you have any lying around.

 Fran

 EDIT: I don't think you need matched tubes. Well I didn't buy them like that anyway. I think once they all "wear" at the same rate then your OK.


----------



## fierce_freak

Cool. I was hoping to get started tonight, but I may not have the time until Sunday...not that I can finish the amp without the tube sockets, haha


----------



## fierce_freak

Unfortunately, I didn't receive the tube sockets or the low-pass filter caps today, but everything else is soldered up and ready to be tested. Assembly took only an hour and a half (for aikido, tread, and optivol), including using steel wool on all the part leads to remove oxidation then cleaning with isopropyl alcohol to remove any particles leftover. I'm dying to try it out, but Monday will be the earliest I will receive my parts.

 I hope the silver micas I ordered end up being the black kind...as it stands now, all components on the board are red, except for white for C1, C3, C12, and C13, and C7-10 and LM317+ heatsinks are black. Looks pretty cool.


----------



## fierce_freak

Got the sockets today and have the amp up and running (caseless). It already sounds awesome, but I'm going to leave it to cook overnight.

 Unfortunately, the Optivol is not working. Figures the simplest part would have the problem, haha. I think it's because of this (I'm having to turn volume down in the digital domain by -50dB) that I'm getting a bit of static.


----------



## looser101

Quote:


  Originally Posted by *fierce_freak* /img/forum/go_quote.gif 
_Got the sockets today and have the amp up and running (caseless). It already sounds awesome, but I'm going to leave it to cook overnight.

 Unfortunately, the Optivol is not working. Figures the simplest part would have the problem, haha. I think it's because of this (I'm having to turn volume down in the digital domain by -50dB) that I'm getting a bit of static._

 

The optivol seems fairly simple. You should be able to get it going with some help from the supplier.

 We need more listening impressions when you are ready.

 Renato


----------



## fierce_freak

For sure. I feel fairly confident in saying it is at least the B22's equal.


----------



## fierce_freak

I have some issues with DC offset, too. Just wanted to note that.

 -edit- swapped in a stepped attenuator for now in place of the Optivol. Static is gone, but I'm getting a low level hum in the right channel...dc offset?


----------



## looser101

Quote:


  Originally Posted by *fierce_freak* /img/forum/go_quote.gif 
_I have some issues with DC offset, too. Just wanted to note that.

 -edit- swapped in a stepped attenuator for now in place of the Optivol. Static is gone, but I'm getting a low level hum in the right channel...dc offset?_

 

Not sure how or when you are measuring this DC offset. The output cap is there to block DC.

 Hum in one channel may be as simple as an input wire to close to a source of AC (ie. transformer).

 R


----------



## fierce_freak

That's what I thought, but I get ~200mV at turn on (from output ground to output signal) then it drifts around under 3mV after that.

 I'll have to isolate the hum later. The transformer is in a wallwart 2 or 3 feet away plugged into the wall. Maybe I'm picking it up from something else.

 -edit- the volume of the hum changes with time. sitting and listening to a couple songs, it can start out at a medium volume, almost disappear during the course of the songs, and then come back louder than ever at a later point, all without anything moving.


----------



## kvant

Quote:


  Originally Posted by *fierce_freak* /img/forum/go_quote.gif 
_That's what I thought, but I get ~200mV at turn on (from output ground to output signal) then it drifts around under 3mV after that._

 

With or without headphones plugged? If without then it is a non-issue. From inside this thread:

  Quote:


  Originally Posted by *fran* /img/forum/go_quote.gif 
_On the DC offset issue: I think I was making a mountain out of a molehill in a way. Just like the millet, there is a DC offset at turn-on, which rapidly drops. With no headphones plugged in this remains about 20mV or so. Plug in some cans and it drops to zero right away. 

 I've spoke to John Broskie about this. His explanation is that:

What happens is that the electrolytic capacitors leak a small current which against the 10k terminating resistor ends up equaling a fairly big voltage. But that same amount of current against 32 or 300 ohms makes for a 32/10k or 300/10k as much voltage offset._


----------



## fierce_freak

That's with headphones plugged in...without, starting offset is greater than 200mV (goes over the range selected on my dmm) then settles to around 60mV.


----------



## fran

mmm my offset issues went as soon as I plugged in the cans. I did mount up a e12 delay though for the cans jack just in case. 60mV sounds right with no cans plugged in - it must be very low current though because as soon as you plug in the cans it drops to zero (in my case). You need to check out that DC. 

 The hum won't be the offset - AFAIK offset is inaudible other than heating the coils of the driver. The hum has to be a grounding issue. Just to check - is the board grounded at one of those standoffs , can't remember which one now, but theres a jumper on the board you can include or leave out.

 I know you will have checked your grounds - don't tie them all together at the PS (as you would a conventional preamp) run inputs to the PCB and then outputs back to the cans/output RCAs. Otherwise you will have a hum. How are you powering this again?


 Fran


----------



## fierce_freak

The hum goes away if I put the inputs straight into the board (no attenuator/pot), but then I have to attenuate the sound level on my PC (turn the digital out to -50dB) and then I get a static that changes with the sound (noisy tubes?).

 I'm using a tread running at 25v. Signal and ground from input RCA's goes to aikido input signal and ground. Output headphone signal and ground go to headphone jack. The only ground connected between the PS and the amp is from gnd from tread to gnd on both H and B+.


----------



## fran

It seems that the issue is with the grounding within the stepped pot. I had the same issues with a different pre I built. Try grounding the back plate of the pot and the shaft too. If you have a metal knob, does the hum go if you touch it?

 From what you say I don't think its the aikido as such, but the volume control.

 On the optivol:


 Did you get Gregs instruction sheet? Check it over - when I got mine there was a mistake in it, it told you to put in a LED backwards. LED blew instantly on power on and then the unit wouldn't work of course. If you have a LED test on your DMM you could check for that. You can trace the pos trace around the PCB and make sure you have the anode of the LED to it.


----------



## fierce_freak

You know, I was thinking it could be the LED polarity. I'll check that tonight after work.

 I do think the hum is volume-control related, but I'm not sure what to make of the static-y noise that changes with the music.


----------



## fran

OK, keep us posted.


 Fran


----------



## fierce_freak

Just got home and fixed the Optivol (pretty stupid, I had C1 and the LED swapped). All noise is gone now. I should be getting my SPL meter in the mail tomorrow, so I can level match this and the b22 for a proper comparison.


----------



## fran

Excellent, thats great news. Photos and impressions please!

 Fran


----------



## fierce_freak

Here are some photos. I didn't take any after I got it all hooked up to work, but nothing interesting to show there.


----------



## fran

Nice build - much neater than mine I think! Even your colours are coordinated!

 Fran


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## fierce_freak

Thanks, fran. It's funny how stuff like that works out


----------



## dBel84

a job well done , that looks great..dB


----------



## fierce_freak

Thanks dBel84 
	

	
	
		
		

		
		
	


	




 The hum has returned. I took a minute to double check the tone of the hum against a tone generator, and it's 120hz hum (I thought it sounded higher pitched than normal hum). From previous conversations with looser101, I know this has to do with the power supply (ripple or oscillation?).


----------



## looser101

Quote:


  Originally Posted by *fierce_freak* /img/forum/go_quote.gif 
_Thanks dBel84 
	

	
	
		
		

		
			





 The hum has returned. I took a minute to double check the tone of the hum against a tone generator, and it's 120hz hum (I thought it sounded higher pitched than normal hum). From previous conversations with looser101, I know this has to do with the power supply (ripple or oscillation?)._

 

If your Tread is set to 25.2v turn it down to 24v and see if the hum goes away (I got a feeling about this). Nice looking build too.

 R


----------



## fierce_freak

I'll give that a try when I get home. I was actually considering that (dropping the voltage), wondering if the measley transformer I'm using is giving the tread enough voltage for the regulator to drop 2 volts.

 Speaking of the tread, can an LM338 be dropped in place of the LM317? It looks like a drop in replacement (in a different form), and it can dissipate up to 50W.


----------



## looser101

Quote:


  Originally Posted by *fierce_freak* /img/forum/go_quote.gif 
_I'll give that a try when I get home. I was actually considering that (dropping the voltage), wondering if the measley transformer I'm using is giving the tread enough voltage for the regulator to drop 2 volts.

 Speaking of the tread, can an LM338 be dropped in place of the LM317? It looks like a drop in replacement (in a different form), and it can dissipate up to 50W._

 

Yup, that's what I was thinking. As your wall voltage fluctuates it can cause the hum to come and go. Also if you look at the datasheet you will see that the dropout voltage is dependent on the temperature of the regulator and the current being drawn. And of course what's in the datasheet are typical values and not necessarily real life. LM338 is overkill in my opinion. You don't need a part that provides a lot more current than your circuit is drawing. Some people claim the LM338 has better specs but I've never bothered to verify that. I guess it won't hurt to experiment if you have it on hand.

 R


----------



## fran

I'm not sure that 2V is enough to make sure that there is no dropout. You'd probably be better to run the amp a bit lower in the likelihood that you'll end up with better sound. You might need to adjust that resistor on the optivol if its much lower. 

 I think the LM317, 338 and theres another I can't recall right now will all fit, but I think there are other components on the tread that are current capped (rectifier?). In any case, its probably the voltage more than the current thats your problem. Time for some measurements with the DMM.

 A lot of ripple won't do the sonics of the optivol any good either - it likes a nice smooth supply AFAIK.

 Fran


----------



## looser101

LM350 is the other common one. It's cheap and good for 3amps.
 If you are real close on drop out voltage you can try adding capacitance before the regulator.


----------



## rodentmacbeastie

So Fierce, any impressions on the B22/Aikido front?


----------



## fierce_freak

I will say that the soundstage on the aikido is definitely superior. Tomorrow I'll have the chance to do much more detailed impression (I have the day off tomorrow, and the fiancee has to work).


----------



## fierce_freak

I'm about to start a brief comparison, so expect an update soon.

 In the meantime, an update on the hum I'm experiencing. I turned down the voltage on the tread to 24v, depending on time of day, the hum is gone, but at other times it cuts in and out constantly (with a small click or pop everytime it comes and leaves), so I must be on the edge of enough headroom for voltage drop at times.

 Anyone have any idea why it only appears in the right channel? Also, obviously the Aikido circuit cuts down on power supply noise quite substantially. I can't imagine how loud the hum would be otherwise.


----------



## fran

mmm interesting that - my left channel has a tiny bit of hum (only noticeable when used as a pre for the speakers - and my sensitive full range speakers at that) but I put it down to the power transformer being down that end of the amp - and too close to the PCB.

 Hum must be due to the voltage from what you say. Would you have a bench supply you could temporarily sub in to see if the problem goes away. Also I suppose try turning down the tread a bit. You might not loose anything sonically. Or you could add in an extra pi filter after the heaters have been tapped off?

 Fran

 EDIT: meant to say can't wait for your impressions! Mine is downstairs doing preamp duty but I think it will return upstairs and do headphone duty soon.


----------



## fierce_freak

This is a tough battle between the two amps. They're very even in overall performance (to my ears), but they are different.

 The Aikido has a bigger and nicer soundstage than the b22. Sometimes, seperate elements of sound are easier to follow on the Aikido due to this, but there are times when the b22 can pull out some small stuff that the Aikido doesn't do as well. It's very give and take between the two.

 I feel that the Aikido is certainly more dynamic and impactful and ever so slightly fuller sounding. Overall, I'd call the Aikido more natural sounding and the b22 more accurate sounding (if that makes any sense); the aikido is emotion without thought, just enjoyment and gratitude for having such great sound, the b22 is a powerful tool, a pinnacle of the thinking human minds achievment, missing nothing...but the differences aren't as big as you might imagine (nor is the gulf between the two big as the previous statements may make it seem...it's a small thing).

 As it is, I haven't been able to choose a winner between the two (which for me is somewhat unfortunate). Further comparison will need to be done, but I think the impressions above are pretty accurate.


----------



## rodentmacbeastie

Fierce,
 You have heard "The Bomb" and your 24V right? Would you say that they sound more or less the same, or does the high voltage one prevail? My thinking is that the better selection of noval tubes and high voltage might help the Aikido out. I had been trying to figure out how to build an Aikido and then this board was released. I would like to use it as a preamp and a headamp and will only ever drive HD650. I can make a HV one with 6H30(or 6H6P) and 6CG7 tubes like "the Bomb" with a switch to change cap values between head and pre. If it is going to sound better, this is the way I will do it. But if a low volt hybrid is nearly it's equal I would then go this route. I am concerned about the meager selection and high prices of 6GM8 tubes though. I also would be eager to hear your impression of this tubes compared to a 6922 or 6SN7. A balanced set-up would be easier with the 24V too I suspect... Hmmm, a balanced Aikido.

 In "The Bomb," the huge output caps were because it was designed to drive Grados(low impedance), right?


----------



## looser101

Quote:


  Originally Posted by *rodentmacbeastie* /img/forum/go_quote.gif 
_In "The Bomb," the huge output caps were because it was designed to drive Grados(low impedance), right?_

 

Short answer: Yes


----------



## fierce_freak

rodentmacbeastie, it's been over 6 months since I heard the bomb, but if asked to go on audio-memory, I'd say they were very similar in sound.

 John Broskie has an article on his blog about a balanced Aikido if that interests you. I'm seriously considering building a second 24v Aikido to run balanced (AikiDos? AikiDeux?) if I decide to stay with it instead of the balanced b22 (which I probably will...I believe I can listen for much longer periods with the Aikido without suffering fatigue).


----------



## fran

just listening to it here now after moving it back up to the office where the PC is. God it sounds good. Best amp I've heard - not that I've heard many, but I'm in bliss right now!!

 On another point, this version of the aikido is just as nice as the other 24V one I built on the mono 9 pin boards, can't tell the difference between them. This is one example of a piece of equipment that really is dual purpose. It really is a great can amp and a really great pre as well. Not many things like that out there.


 BTW, if you were going to be using one headphone only, you could use a transformer output and avoid those output caps. I have read of using a small VA 24V to 110V toroidal transformer to do the job. Would be interesting, wouldn't it?

 Fran


----------



## rodentmacbeastie

Oop! Double post.


----------



## rodentmacbeastie

Fierce and Fran, any news on break in or the sound changing? Any more impressions? I am dying here waiting for JB to release some new boards! I have been without a system at all for nearly 5 months and not had a descent one for 2 years. My speaker rig is in Thailand at my Girfriend's place and I have nothing here in Canada! She is there, the remaining rig is there, my life is there, I am here in silence with my thoughts! I am going bloody crazy here. I thought, "hmmm, a month when I get home to Canada to research and build and I should have music. First, I want the Opus and Aikido(6CG7/6H30). Then the Opus is coming with DSD. Then the DAC chip is delayed. Then JB makes this amp and even though I suggested to him in an email before this release stating that an amp that is simple and easy to build would be a huge hit at headfi. He only made a few and I am waiting... 

 Now, Twisted Pear is coming out with the Buffalo DAC which is exactly what I want as is the Aikido. I can't remember a time when I could say that the consumer market had exactly what I want or need. This combination is exactly what I NEED! DIY with help from boards make it possible for amateurs to get into it! I love that I can get a headamp for a few hundred dollars that is being compared to the recent champ, the B22! I love that I can go balanced later very easily and not having to sell this and buy a new one! I love how it works well at 24V so we can have great sound at non-lethal voltages! I love how TP and the Sabre DAC will answer all my needs for years to come. I love the top quality of product and service from both TP and JB. I love that it is not just another dollar in a huge multinationals coffers.

 I am dying by the day without my music, but it WILL be worth the wait! My hats off to the likes of JB, the folks at TP, and every helpful DIY company out there! I think it is great that with a little of their guidance and great products to boot, we can experience hifi at the price it should be and not the criminal price of most high end gear! Not to mention that many of us fall victim to the belief that WE ARE USELESS! We are not, we are just plain lazy. DIY and the internet must be making a significant dent in the hifi sales market. I truly believe that this is the way trade was meant to be! 

 I want an amp. I choose a design(er), or do it myself. I get someone to build the design, or do it myself. That someone choose the parts quality for me, or do it myself. Find a fabricator for the chassis, or do it myself. At every step I can spend as much or little as I want. This would lead to me getting the right amp personalized to me for what should be less money. Just think how the world would benefit form this model. If the the customers want choice there is no better way. The power would slowly shift back to the people and away from the corporate giants, that with good marketing, are desrtroying the very fabric of society that we wove over last few million years! The responsability to the planet's survival would return. The innovation and creativity that has been shunned by conventional thinking corporate giants would reign supreme. It could if done right be very efficient as well. People could get quality, lasting goods that suit their need and thus become useful and not disposable. The quality of life should increase dramatically as well. The small, powerless genius could freely release to the world the plans for cold fusion thus ending oil's dominion over us! All because of two things, DIY and consumers getting a life outside of buying things and be happy with life and a little less. Although it would require consumers to buy less, what they did buy would be what they want and need and would last them longer. DIY may save the world!


----------



## fierce_freak

Funny you should post, as I was just coming here to make an update 
	

	
	
		
		

		
			





 I decided to get a medical-rated 24v external power supply and give that a try. I've got it put in place of the TREAD today and have been giving it a listen: any and all background noise is gone, leaving dead silence when nothing is playing. I'm not sure if it's because of the removal of some small noise issues I was having, but I'm also hearing a slight increase in the amp's already superb retrieval of low-level and micro- details. I'm very pleased, and I've ordered a case and custom front panel to tie the whole thing together in the coming month (hopefully ;D).

 One last thing I'd like to add is something akin to the e12, but simpler so as to save on space. I'm going to remove the dc offset protection and power supply section of the e12 schematic and use just the muting relay (after I ask amb for permission and verify that my idea is good, of course) with a mute time of 4 seconds or so after turn-on.


----------



## rodentmacbeastie

e12?


----------



## looser101

Quote:


  Originally Posted by *rodentmacbeastie* /img/forum/go_quote.gif 
_e12?_

 

HERE


----------



## rhester

Has anybody tried the other aikido amps? Just wonderin' since there are no 24v boards available and no indication when some might be ready? Any ideas?


----------



## fierce_freak

looser101 sent me a good looking schematic for mute delay, but I wanted to go ahead and post what I was thinking when I spoke about modifying amb's e12:






 Does that look feasible?


----------



## looser101

Don't think that will work with the resistor voltage divider, but you could use a 12v regulator. Or you could use THIS but I don't see the advantage myself. But it achieves the same thing with extra components.

 rhester - you could use the normal stereo 9 pin board (see tubecad site for mods needed to use it) and then make the output buffer on perf board.

 R


----------



## fierce_freak

Thanks, R. Do you think it'd be alright to use a 24v activated relay and forgo the regulator?


----------



## looser101

Quote:


  Originally Posted by *fierce_freak* /img/forum/go_quote.gif 
_Thanks, R. Do you think it'd be alright to use a 24v activated relay and forgo the regulator?_

 

Don't see why not if you can find a suitable relay.


----------



## looser101

AMB (Ti) has this to say about setting up the e12 in this type of situation:

*Amplifiers with a single supply, non virtual ground*
 Amplifiers in this category include the Millett Hybrid, YAHA and Szekeres. The ε12 provides muting delay functionality only. No DC offset protection is provided, but these amplifiers have an output coupling capacitor that blocks DC. The rail splitter and DC offset sensing portions of the ε12 circuit should be omitted, and a some other modifications should be applied as follows:

 * Do not populate the following parts:
 U1, U2, R2 through R10, VR1, Q2 through Q4, C4 through C6, D3, D4
 * Use a 12V zener diode (1N5242B) for D1
 * Install a wire jumper in place of R2
 * Install a wire jumper across the C-E pads of Q2
 * Install a wire jumper in place of C4

 The power supply voltage to the ε12 is 12V to 30V in this configuration. A TO-92 clip-on heatsink should be used on Q1 if the supply voltage is greater than 18V.


----------



## fran

Yes, if you go to amb's site, there are instructions for using the e12 as a muting relay only for single rail supplies. Its works fine, you have a PCB to work with and you only need a few parts.

 I mounted mine on top of the aikido board near the headphone output - looks neat enough. And I don't know if 4 seconds is enough - I think I would go for a bit longer, maybe >15 secs. If you use the standard parts that amb has listed, you will get around 15-20 seconds.

 Thats very interesting about the switching supply. When I use it as a preamp with some sensitive full range speakers I can hear some hum in my right channel - its low and you wouldn;t hear it more than a foot away from the speakers - but thats the end of the board nearest the power transformer. Can't help but think that it would be gone if I used an offboard supply. 

 I think I'll keep an eye out for one of those switching supplies. 

 Fran


----------



## kvant

Quote:


  Originally Posted by *fierce_freak* /img/forum/go_quote.gif 
_Thanks, R. Do you think it'd be alright to use a 24v activated relay and forgo the regulator?_

 

I tried just that with Mouser part No. 653-G6A-234P-DC24 and the start-up delay worked very well. What I didn't completely like on my implementation was that after switch-off the relay didn't disengage fast enough to prevent switch-off transients. However, I don't see how the regulator could speed this up (but then again, I never tried with the regulator). I think that this had more to do with powering the relay from the same rail (and the same slowly discharging caps) as the amp.


----------



## fierce_freak

Thanks everyone 
	

	
	
		
		

		
		
	


	




. I knew about using the e12 in the function I wanted, but the footprint of the board is too large unless I somehow mount it to the front panel (I know, I'm working in pretty tight spaces).

 Is the default 15-20 seconds? I'll use the same values then. I could swear I read somewhere on the site that it was set at 3 seconds, but I could definitely be wrong.

 Here's another oddity: since I've started using the medical switching supply, I don't get the loud hum for about 1 second from the headphones that I used to at turn on...was that just the PS giving out a lot of ripple during turn on?


----------



## rodentmacbeastie

Updates? Impressions Fierce? Anyone else built their 24V yet? If not, someone want to sell me a board so i can get started?


----------



## fierce_freak

The amp is awesome. I've got most of the parts I need to make a second one to run them balanced. I do plan to make a ptp-wired over-the-top tube amp in the near future (2-4 months), but I think it's going to be hard for me to top it with my own design.


----------



## fran

I've heard it said by some tube gurus that the aikido is one of the best sounding preamp circuits that he has ever heard. yes it would be hard to top. The killer in this particular app is that you also get an extremely good preamp too. 

 Fran


----------



## fierce_freak

Yeah, I've seen it praised pretty well, with some saying it's beaten by some DHT based preamps or other such esoterica.

 I've been doing some thinking about the output caps on the Aikido. Currently, headphone output is 1000uF NX Blackgate bypassed with 0.47uF Mutlicap RTX. The sound is pretty awesome, but I wonder if getting the BG out of the way could improve things and also take care of DC offset issues. Of course, that means using a larger valued film cap.

 JB himself suggested I use a 30-47uF Erse cap bypassed with a quality 0.47uF cap. This would be sufficient for the HD650's, but I hate to cut my options of using Grados again in the future. Erse does make a 200uF cap, but I can't find a place to buy it (if anyone does, let me know!). Mundorf does make a 220uF M-Cap series cap, but they are pretty expensive (of course). There is also Solen, but JB advised that Erse sounds better.

 Anyone have a suggestion on which way I should go and how it might compare to the BG+Multicap combo? I've also considered the 47uF Obbligato film caps. Any other suggestions for good 30+uF caps?


----------



## luvdunhill

Quote:


  Originally Posted by *fierce_freak* /img/forum/go_quote.gif 
_Yeah, I've seen it praised pretty well, with some saying it's beaten by some DHT based preamps or other such esoterica.

 I've been doing some thinking about the output caps on the Aikido. Currently, headphone output is 1000uF NX Blackgate bypassed with 0.47uF Mutlicap RTX. The sound is pretty awesome, but I wonder if getting the BG out of the way could improve things and also take care of DC offset issues. Of course, that means using a larger valued film cap.

 JB himself suggested I use a 30-47uF Erse cap bypassed with a quality 0.47uF cap. This would be sufficient for the HD650's, but I hate to cut my options of using Grados again in the future. Erse does make a 200uF cap, but I can't find a place to buy it (if anyone does, let me know!). Mundorf does make a 220uF M-Cap series cap, but they are pretty expensive (of course). There is also Solen, but JB advised that Erse sounds better.

 Anyone have a suggestion on which way I should go and how it might compare to the BG+Multicap combo? I've also considered the 47uF Obbligato film caps. Any other suggestions for good 30+uF caps?_

 

As far as a amazing sounding 200uF film capacitor, check out North Creek's clearance / blimished caps. These caps are freaking huge, but sound absolutely wonderful (and are cheap, considering they're going out of business and all). If you're interested, I might be able to spare one that you could use for testing and return it when you're done. Just let me know.

 Link: North Creek Specials

 $20 plus shipping each

 Also, I'd recommending trying without the RTX bypass for grins. I've never found a Black Gate that sounds good bypassed, even with the excellent RTX.

 I've used ClarityCaps before and they sound decent, but I'd say my favorites in the high capacity department are the North Creek Zen followed by the Multicap metalized.


----------



## fierce_freak

I'll give the black gate only a try on Sunday. I'm hoping to ditch the 'lytic, though, due to the DC offset issue. I'd prefer not to use a relay, but I will if it comes down to it.

 Do you have the dimensions on the Zen caps?

 -edit- nvm, found it...the thickness of the cap might be just a hair too much, argh!

 -edit2- they're relatively cheap so I went ahead and sent in an order for some. Have you tried their harmony caps as bypass?


----------



## kvant

Quote:


  Originally Posted by *fierce_freak* /img/forum/go_quote.gif 
_I'm hoping to ditch the 'lytic, though, due to the DC offset issue. I'd prefer not to use a relay, but I will if it comes down to it._

 

What issue? If you mean the leakage current, then it is a non-issue. There is no offset when the phones are plugged in and if there is some without phones, it does not really matter. You can change the 10k resistor on output (per Broskie schematic) to 1k. This will make the unplugged offset 10 times smaller (and you maybe happier). If you mean the turn-on thump, then that will be there even with a film cap. So, if you want to ditch the 'lytic, do it for other reason than the DC offset.


----------



## fierce_freak

I want to ditch it for sound reasons mainly, but DC offset is an issue at power on, though not serious. Even with the cans plugged in, initial offset is almost 200mV, though brief. Turn-on thump is a pain, but I don't believe it will damage the cans. What do you think? Also, do you think a cap like the one mentioned by luvdunhill will sound better than the blackgate? Sure, it's a blackgate, but it's still an electrolytic.


----------



## luvdunhill

Quote:


  Originally Posted by *fierce_freak* /img/forum/go_quote.gif 
_I'll give the black gate only a try on Sunday. I'm hoping to ditch the 'lytic, though, due to the DC offset issue. I'd prefer not to use a relay, but I will if it comes down to it.

 Do you have the dimensions on the Zen caps?

 -edit- nvm, found it...the thickness of the cap might be just a hair too much, argh!

 -edit2- they're relatively cheap so I went ahead and sent in an order for some. Have you tried their harmony caps as bypass?_

 

they're giant... just be ready for that. I think the the Black Gate N/NX sound very, very good in coupling situations. Don't underestimate them.

 As for the Harmony, yeah I've tried them, but there's a lot of stuff out there I really like... basically any polystyrene mixes and things like ROE MKP1837/1830 etc. I have some various MKP1837 still left if you're interested. Odd sizes though, > 0.01uF and < 0.1uF (note lack of equality there).......

 edit:

 should note I haven't tried the Harmony in electronics bypass, mostly in tweeter crossovers, and there they are very excellent ... definitely a fav.


----------



## fierce_freak

Thanks for the info, Marc. I guess I'lll test between BG, BG w/ RTX, and Zen cap.

 As far as turn-on thump...how much is too much? When I switch on the Aikido with HD650's connected, I can very clearly hear the thump from 3 feet away.


----------



## luvdunhill

Quote:


  Originally Posted by *fierce_freak* /img/forum/go_quote.gif 
_Thanks for the info, Marc. I guess I'lll test between BG, BG w/ RTX, and Zen cap.

 As far as turn-on thump...how much is too much? When I switch on the Aikido with HD650's connected, I can very clearly hear the thump from 3 feet away._

 

cannot beat that price, that's for sure 
	

	
	
		
		

		
			





 did I mention they're huge?


----------



## kvant

Quote:


  Originally Posted by *fierce_freak* /img/forum/go_quote.gif 
_As far as turn-on thump...how much is too much? When I switch on the Aikido with HD650's connected, I can very clearly hear the thump from 3 feet away._

 

O.K. And how far you hear the phones when they are playing music at your normal listening level? And how far when they are playing very loud but still within their specified limit? I guess that you can hear them much farther.

 On the turn-on, the output cap charges through the phones. Calculation says that the amount of energy the phones dissipate during this charging is equal to the energy stored in the capacitor in its charged state (which here is 12V across it). If you evaluate this energy and compare it with the maximum rated power the headphones can take, you will see that there is little to worry about. BTW, all my amps are cap coupled on output and I use Grado, which are more problematic as far as DC offset is concerned. I typically unplug them, but not always. Nothing ever happened to them.

  Quote:


  Originally Posted by *fierce_freak* /img/forum/go_quote.gif 
_ Also, do you think a cap like the one mentioned by luvdunhill will sound better than the blackgate? Sure, it's a blackgate, but it's still an electrolytic._

 

I am pretty sure I am not of people you want to ask this question. If I have to take a side I take the one that has 'snake-oil' in vocabulary. Ask *Ferrari*, he pulled a stunt like that with his Millett hybrid.


----------



## fierce_freak

I'm really pretty open to anything, because I don't pretend to know that much about this stuff. I can put stuff together pretty well, but I don't have the experience or knowledge to say much more than that.

 You are pro or anti Blackgate? I've never really read any of the debates on them.


----------



## fran

I thought that JB recommended some panasonic FM in there. He sent me a few to try and they sound pretty good, but a regular 3300uF nichicon double bypassed with 2.2 wima and 0.22 PP was as nice.

 Try adding a second bypass of lower value again and see if it helps. IMHO in this config the sound signature will be that of the bypass caps with the electrolytic fading out of the equation.

 Fran


----------



## TimJo

Quote:


  Originally Posted by *fran* /img/forum/go_quote.gif 
_a regular 3300uF nichicon double bypassed with 2.2 wima and 0.22 PP was as nice._

 

Hey Fran,

 Just curious, when you said a _PP_, what brand were you refering to? Or did you just mean a polypropylene?

 -Tim


----------



## fierce_freak

I woke up in the middle of the night and couldn't sleep, so I got up and took the RTX's off the board (lol). I have to do more comparison, but I think I prefer it blackgate-only. Bass has lost a touch of bloom I noticed with the bypass combo, soundstage has improved even more (!), and some of the really low level stuff is a bit better defined.

 Marc, have you compared just a BG NX on output to the Zen caps you mentioned earlier (in any application, not Aikido obviously)?


----------



## luvdunhill

Quote:


  Originally Posted by *fierce_freak* /img/forum/go_quote.gif 
_I woke up in the middle of the night and couldn't sleep, so I got up and took the RTX's off the board (lol). I have to do more comparison, but I think I prefer it blackgate-only. Bass has lost a touch of bloom I noticed with the bypass combo, soundstage has improved even more (!), and some of the really low level stuff is a bit better defined.

 Marc, have you compared just a BG NX on output to the Zen caps you mentioned earlier (in any application, not Aikido obviously)?_

 

no, unfortunately not. I have been meaning to go back to some BG NX in my phono stage output, but I'm currently running it DC coupled... strange thing in that case is I almost prefer the BG NX, which is super strange. The Zen caps came to my mind primarily because you were looking for a large 200uF cap for cheap. you'll definitely want to play with bypassing those. How will they compare to the BG NX, I'm not sure at all. I just have found that the BG N/NX defy their classification as electrolytics.

 PM me your address and I'll drop some MKP1837 in the mail for you to play with.


----------



## fran

Yes, PP means polyproylene - afraid i have no make as such as they were sold by a local chain here Maplin. They look like earlier sonicaps but I doubt that they are - they were pretty cheap!

 So my set up for C4:

 panasonic FM 1800uF and then in C3 I have the big PP 2.2uF caps and then tacked on outside that again I have some of the russian KY42 caps from the millet max build 0.22uF.

 Pic here:





 I know thats not the closest pic ever but you get the idea. The board on top of the RHS is the e12 delay on the headphone output.

 Fran


----------



## fierce_freak

Fran, you seem to be in closer contact with JB than I...do you know if he's ordered a second run of 24v Aikido boards yet?

 Re the BG NX's: I've left the amp playing with only the blackgates for for about 24 hours now. I can say now that blackgates only is superior (to my ears) to blackgate plus rtx. I'm wondering now if it's even worth it to try with the Zen caps.


----------



## fran

Sorry, not in close contact with him at all. I take it you emailed him?

 I know I've emailed him on occasion before and it would take a while to email back, sometimes a second one with the same subject header helps. I'm sure he will get them back in stock. Maybe email him and say you need a second one for a balanced amp or something. He might have a spare lying around he could give you.

 Can't hurt!

 Fran


----------



## rodentmacbeastie

Hello Freak,

 I am back from solitary confinement, lol. I would love to know if you have a parts list for your amp? Also, if I want to go balanced would I just double the order or would there be different values? How are you liking it with your Buffalo?


----------



## fierce_freak

Heya macbeastie. Funny you should bump the thread as I just got my second Aikido board yesterday (John will have them up for sale soon, as far as I know). Parts values will just be doubled. I'll have to hold off a couple days on a parts list as some small changes have been made to this second run of boards (just some layout changes, 3-5 extra resistors (i'd need to count), larger physically sized caps in the heater string). I'm also going to try using the LT1085 in place of the LM317 (on John's recommendation) to see if there is any change in SQ.

 I also sent John a balanced HD650 cable, so I image he will be doing some testing with balanced drive when he finds time (gods know he doesn't have enough of it).


----------



## rodentmacbeastie

Quote:


  Originally Posted by *fierce_freak* /img/forum/go_quote.gif 
_Heya macbeastie. Funny you should bump the thread as I just got my second Aikido board yesterday (John will have them up for sale soon, as far as I know). Parts values will just be doubled. I'll have to hold off a couple days on a parts list as some small changes have been made to this second run of boards (just some layout changes, 3-5 extra resistors (i'd need to count), larger physically sized caps in the heater string). I'm also going to try using the LT1085 in place of the LM317 (on John's recommendation) to see if there is any change in SQ.

 I also sent John a balanced HD650 cable, so I image he will be doing some testing with balanced drive when he finds time (gods know he doesn't have enough of it)._

 



 That sounds great! When you finalize the parts list can you please send me a copy?


----------



## fran

Hard to see how the amp could be improved - but then I never thought that a couple of LM317s would sound so bloody good. I'll be interested to read how you get on with the LT1085.

 Looks like Brian and Russ will have Sabre kits in a couple of weeks - need to be around for that!

 Fran


----------



## rodentmacbeastie

Freak,

 I am interested in how your Buffalo and Aikido are sounding once burned in? Have you tried it with the IVY? I would like to try passive I/V conversion then amplify the signal versus active I/V with opamps. If I remember correctly, you have been using the Buffalo as a voltage source. Have you tried it as a passive (resistor) and then diractly to your Aikido? My other idea is that one should take the current output and amplify it in the current domain, then use a resistor. Would this be possible?


----------



## fierce_freak

Lately I've been considering going a radically different direction with my rig, so I've been considering selling my Aikido builds, much as I'd miss it. Is anyone interested in taking a populated board off my hands, or perhaps even the stuff needed to put a balanced one together (I have custom FPE panels for this project...*sigh*)?

 rodentmacbeastie: Buffalo + Aikido is a flippin' sweet combo. I haven't tried the IVY, but I plan to next week. I haven't tried using a resistor for I/V. You could amplify the current like you suggest, but I'm unsure that there would be any benefits over first converting to voltage then amplifying _that._ That would be something you'd probably have to try on your own and let your ears decide.


----------



## rhester

I just got the new version of the board, and it has hi voltage options now. For those with the 24V, would it be woth the hassle to go higher and different tubes or still with the low v version?


----------



## rodentmacbeastie

Freak,

 The reason why I was suggesting amplifying the current first is that if you do a passive I/V and amp the signal, you either have a tiny signal to amp with a 12AX7 or bandwidth begins rolling off quickly. I don't like 12AX7 tubes. The tiny signal needs to see as near 0ohms as possible or SQ will be degraded, right? To get next to nothing input impedance for the DAC you would need to use opamps, transformers, FETs, or something like that and I would like to use tubes. But if the current was tube amplified first it might act like a constant current source allowing higher output voltages with resistors that won't cause roll off and it should have plenty of guts to drive the Aikido, sound right? You would be bringing out more low level detail as well I would think. If I understand correctly, you are in love with tubes thanks to the Aikido. I am too. They just sound real.


----------



## fran

Apparently there is a russian equivalent for the 6GM8 - its a 6N27P. Unfortunately a search on ebay throws up a big fat nuthin.

 Fierce: have you come across this info before? it'd be worth buying a set to see how they worked!

 Fran


----------



## fierce_freak

Yes, I've read about the 6N27P. I want to say I've ran across some before, as well, but I can't remember where it was.

 With the same board you could also run 12BH7's at 48v (there are lots of 48v wallwarts). That's something I've considered trying, as well.


----------



## rodentmacbeastie

Fierce,

 Not to jack the thread again but... Have you got your IVY? Russ seems pumped about the new Wolfson Opus. They both suit my needs and the Opus will cost less than half as much in this situation. That extra cash could be put towards a balanced Aikido. I am dying to hear your impressions on that one too! I have already bought four Telefunken ECC86 tubes presumed to be from the sixties with the diamond on the bottom. The boxes still were sealed but for one to take their picture. I had the understanding that only Amperex made these and that all others were rebranded. The diamond on the bottom is not a rebranding so I guess Telefunken made them too. The Russian tube was discussed by John Broske on his tubecad site and if I remember correctly they sound good.


----------



## rodentmacbeastie

What about a 48V Aikido with 12SX7's?


----------



## fierce_freak

I haven't received my IVY yet due to a mixup in communication. It will probably arrive early next week, but I will be out of the state for vacation.

 I've heard of Telefunken ECC86's but have never run across them.

 I've considered 12SX7's in the past (before the low voltage board came out), so you have me looking at them again. Of course, that's another tube that is a bit costly, but it should work nicely at lower voltages, I think.


----------



## rodentmacbeastie

My understanding of the 12SX7 is that it is a 12SN7 with the same "space" technology that the 6GM8 has. They are design to run on 28v or something like that, but can handle up to 80v. My info is only based on someone elses' so you know how it goes. They were made for aircraft radios I think. Apparently the reason they are expensive is that they are reputed to sound like a more tone rich and musical tube and better in every way than the 6SN7. They have roughly the same gain and output more current. A 48V SMPS, or even better if it were a few volts higher so they saw 12.6v. I bet it would be impressive!


----------



## evo_lution

Do you ppl think a STEPS PSU running at 24V is enough to power the Aikido?
 I ask because i'm getting no sound at all out of mine. I've double checked the build, but something funny is going on when i check the B+/GND i only get 2.1V
 The heaters are powered separately via a 15VDC wall-wart.

 TIA


----------



## fran

I ran mine off a tread with no problems - and that was supplying the heaters as well - so yes is the answer. From your description there is something wrong with your power supply. Maybe do a bit of testing, disconnect the steps, check voltage at the steps output, then reconnect it and check voltage where it goes into the board (assuming you're using one of the PCBs) with the heater supply disconnected. Then connect the heaters again and test again. 

 You say you are using a separate supply for the heaters - you must have the heaters wired partly in series/partly in parallel?

 Fran


----------



## evo_lution

Quote:


  Originally Posted by *fran* /img/forum/go_quote.gif 
_I ran mine off a tread with no problems - and that was supplying the heaters as well - so yes is the answer. From your description there is something wrong with your power supply. Maybe do a bit of testing, disconnect the steps, check voltage at the steps output, then reconnect it and check voltage where it goes into the board (assuming you're using one of the PCBs) with the heater supply disconnected. Then connect the heaters again and test again. 

 You say you are using a separate supply for the heaters - you must have the heaters wired partly in series/partly in parallel?

 Fran_

 

Yea got a problem with my PSU, knocked up a quick one using a spare trafo and it works! Cheers Fran


----------



## billnchristy

Hi guys...I don't post here much because I am not a headphones guy but I thought I would share my build since it is a little different.

 Obviously I did not focus too much on the headphone section but I did build it out so I could try it...besides my daughter can use it when she is playing on the PC.

 I built mine with a variety of resistors (as you can see) but they are all metal and 1% tolerance. The caps are also a variety IC, multi-comp and Rubicon. The big honking white ones are IC motor start 4uf and the empty cap slots for the pre-outs are going to be Jantzen Z-superiors.

 C12 and 13 are going to be Jantzen Z-standards.

 My sockets and caps will be here today so I can check this sucker out. 

 Tubes are GE made in Holland and look identical to the Amperex I got a while back.

 Here is my test setup...as you can see I am using a SMPS instead of linear PSU. It is a Lambda medical PSU and I have used them in two solid state pres with good results...hopefully the same will continue here!

 Pot is just a cheap alpha for the time being...I am thinking of doing the optivol but do you need a - voltage with those? If so I don't know how I will impliment that!


----------



## fran

No, you don't need a - supply - just use the 24V B+ to power it. Nice too.....


 Fran


----------



## manaox2

boilermakerfan gave me a lead and the reviews me to take up where fierce left off possibly. I already have the dual mono Opus, ballsie, metronome now and have a buffalo + IVY on the way. I have plenty of 6GM8 tubes, two matched Optivol, a 25+25v toroid, two 24v Aikido line-stage/headphone amp boards and H-PS-1 power supply kits on the way also. I want to have it balanced.

 Its too bad I didn't catch the sell-off on head-fi, what do those custom FPE panels look like? I am planning on working up the NABU case. I am emailing JB to ask about designing the negative power supply rail and am researching what parts to order. Any advice on going boutique from previous builders? Wish I could find a TO-220 package for the BUF634. Renato's was a little too ridiculous to fit in one case balanced and would require a two man job just to move!


----------



## digger945

I've had the DN2540N5 Depletion mode N-channel mosfets in the output of mine for two weeks now, they run infinitely hotter than LM317T's. Sounds perty good with Auri 2.2 and 2x .01's bypassing panasonic FA 1000uF. Even better than BG NX's imo.
 Wish I could find a 2N6660 in TO220 to try. I think I will try the larger regs next.


----------



## manaox2

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_I've had the DN2540N5 Depletion mode N-channel mosfets in the output of mine for two weeks now, they run infinitely hotter than LM317T's. Sounds perty good with Auri 2.2 and 2x .01's bypassing panasonic FA 1000uF. Even better than BG NX's imo.
 Wish I could find a 2N6660 in TO220 to try. I think I will try the larger regs next._

 

Moskido!


----------



## digger945

Do you have Glassware kits or you gonna buy your own parts to populate with?


----------



## manaox2

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_Do you have Glassware kits or you gonna buy your own parts to populate with?_

 

Buying my own parts to populate them with, not sure if I want to go over the top or what changes I might need to make for the balanced implementation yet.


----------



## looser101

Quote:


  Originally Posted by *manaox2* /img/forum/go_quote.gif 
_Buying my own parts to populate them with, not sure if I want to go over the top or what changes I might need to make for the balanced implementation yet._

 

For balanced increase the value of the output cap by 2x.

 R


----------



## manaox2

Quote:


  Originally Posted by *looser101* /img/forum/go_quote.gif 
_For balanced increase the value of the output cap by 2x.

 R_

 

Thanks, so I guess that means at least 660uf in the C4 position though I'm guessing at least 1000uf would be much better. I guess 25V 1000uf blackgates (maybe in a Super-E configuration?) might be what I want to look at?

 Is it worth bypassing at C3 with a low value still in that case?


----------



## BoilermakerFan

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_I've had the DN2540N5 Depletion mode N-channel mosfets in the output of mine for two weeks now, they run infinitely hotter than LM317T's. Sounds perty good with Auri 2.2 and 2x .01's bypassing panasonic FA 1000uF. Even better than BG NX's imo.
 Wish I could find a 2N6660 in TO220 to try. I think I will try the larger regs next._

 

What value resistor do you have installed for R17? The bias current on the 2540 is probably double what it was with the LM317... A 20ohm resistor will put the FETs around 110-115mA bias current. OK on the big 2-1/2" heatsinks, but that's why they are so much hotter. I'm building mine with a DPDT switch to flip between 20ohm and 27ohm resistors for R17. I will probably upgrade to Caddock resistors and go to 20ohm and 40ohm. The 27ohm resistor puts the LM317 at 46.3mA bias current and ~80mA for a 10M45S or any FET in the secondary buffer position. 

 FWIW, I plan to audition the LM317, LM350, LT1085, DN2540, 10M45S, IRFZ34, IRF510, and IRF610 for the buffers. The IRF FETs can only be used as the second transistor and must be fed by a depletion mode FET. I'm using the transistor sockets on my build with standoff and threaded heatsinks to make swapping as painless as possible. 

 Good luck manox2! Sounds like an ambitious build! If you plan to power the OptiVol from 0-24V, you need a ~1.4K resistor for the power drop on the OptiVol board. Greg ships a 1.7K or 1.9K for MAX builds at 27VDC, IIRC... 

 My new OptiVols showed up yesterday along with two BassXt PCBs... The BassXts will be used with the console speakers though, not headphones.


----------



## looser101

Quote:


  Originally Posted by *manaox2* /img/forum/go_quote.gif 
_Thanks, so I guess that means at least 660uf in the C4 position though I'm guessing at least 1000uf would be much better. I guess 25V 1000uf blackgates (maybe in a Super-E configuration?) might be what I want to look at?

 Is it worth bypassing at C3 with a low value still in that case?_

 

Now you are talking religion.
	

	
	
		
		

		
			





 The Millet Hybrid boys (tomb) have some combos that work well, there is no reason they cannot be used here. Minimum for low impedance cans is about 220uf or about 470uf in balanced configuration. Just remember that the actual effective value will be half of what is installed in C4.


----------



## BoilermakerFan

Quote:


  Originally Posted by *manaox2* /img/forum/go_quote.gif 
_Thanks, so I guess that means at least 660uf in the C4 position though I'm guessing at least 1000uf would be much better. I guess 25V 1000uf blackgates (maybe in a Super-E configuration?) might be what I want to look at?

 Is it worth bypassing at C3 with a low value still in that case?_

 

That's one of the beautiful things about JRB's design. C3 is a bypass cap position for C4. You can wire a selector switch to route the signal through C3, C4, or both. No reason why you couldn't add a third or even fourth cap, but the main reason John designed it that way was to allow flexibility to use different caps for sound signature effects, or to allow the smaller value cap to act as a low pass filter to reduce the bass for night time low listening levels, etc. Like many brilliant games, the Aikido seems very simple at first glance, but then as you get into it and recognize it's flexibility and understand it can actually be very, very complicated. 

 What I've discovered is that John has a lot of information in the manual and in his archives of his blog. The trick is finding it. 
	

	
	
		
		

		
		
	


	




 I have some special chassis work planned for Aikido. The chassis is starting out as a NABU, but it may not be that recognizable once it's all done if things go as planned.


 EDIT: manaox2, I'll send you a PM later with the information on the caps John included in my kit. He has a PCB for the 24V PSU available, but you might have to email him for it. I bought it with my kit.


----------



## digger945

Quote:


  Originally Posted by *BoilermakerFan* /img/forum/go_quote.gif 
_What value resistor do you have installed for R17?_

 

Well the original schematic shows 10K and the schematic for the mosfets shows 10k so I have tried 10k and I also tried 5K. Are you sure your not referring to R15(from ground to the bottom mosfet)?
  Quote:


 The bias current on the 2540 is probably double what it was with the LM317... A 20ohm resistor will put the FETs around 110-115mA bias current. OK on the big 2-1/2" heatsinks, but that's why they are so much hotter. I'm building mine with a DPDT switch to flip between 20ohm and 27ohm resistors for R17. I will probably upgrade to Caddock resistors and go to 20ohm and 40ohm. The 27ohm resistor puts the LM317 at 46.3mA bias current and ~80mA for a 10M45S or any FET in the secondary buffer position. 
 

For R15 to set the bias(I have the 24VAikido board ©2007) I am using 5ohms(actually 4x20ohms) to set the bias at 150mA(I am guessing), the schematic says 3.3 to 6.8ohms IIRC.

  Quote:


 FWIW, I plan to audition the LM317, LM350, LT1085, DN2540, 10M45S, IRFZ34, IRF510, and IRF610 for the buffers. The IRF FETs can only be used as the second transistor and must be fed by a depletion mode FET. I'm using the transistor sockets on my build with standoff and threaded heatsinks to make swapping as painless as possible. 
 

I plan to do the 1085 next I think, as I was very impressed with the 317. I mounted the transistors in the upper mounting hole of the heatsinks to make them stand just a fraction of an inch off the pcb, so removal will be much easier.

  Quote:


 Good luck manox2! Sounds like an ambitious build! If you plan to power the OptiVol from 0-24V, you need a ~1.4K resistor for the power drop on the OptiVol board. Greg ships a 1.7K or 1.9K for MAX builds at 27VDC, IIRC... 

 My new OptiVols showed up yesterday along with two BassXt PCBs... The BassXts will be used with the console speakers though, not headphones.


----------



## BoilermakerFan

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_Well the original schematic shows 10K and the schematic for the mosfets shows 10k so I have tried 10k and I also tried 5K. Are you sure your not referring to R15(from ground to the bottom mosfet)?_

 

It's labeled R17 in my Rev. A manual, but yes, it's your R15...


  Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_For R15 to set the bias(I have the 24VAikido board ©2007) I am using 5ohms(actually 4x20ohms) to set the bias at 150mA(I am guessing), the schematic says 3.3 to 6.8ohms IIRC._

 

I remember the reference to the 3.3-6.8ohms from the blog for your R15 (my R17), but the schematic for that blog entry is different than that used on the actual boards. I have the print out in front of me with DN2540N5s in both positions. I'll email John to see if the DN2540 should follow the 10M45S curve for resistor values and let you guys know when I find out. I think if you remove 3 of the 20ohm resistors you'll get the heat down and still have it sound good. Since they are both depletion mode FETs, I'm not sure if they have the same requirements for setting bias, but John did tell me the 10M45S was completely different than the LM317...



  Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_I plan to do the 1085 next I think, as I was very impressed with the 317. I mounted the transistors in the upper mounting hole of the heatsinks to make them stand just a fraction of an inch off the pcb, so removal will be much easier._


----------



## digger945

Quote:


  Originally Posted by *BoilermakerFan* /img/forum/go_quote.gif 
_That's one of the beautiful things about JRB's design. C3 is a bypass cap position for C4. You can wire a selector switch to route the signal through C3, C4, or both. No reason why you couldn't add a third or even fourth cap..._

 

I soldered two pieces of 18ga strand to the pcb and use alligator clips and test leads to try out different caps in the C3 position. C4 is soldered in for now, and I have tried the BG NX 25V 1000uF (included when I bought this amp from Fierce Freak) and now I run a 16V 4700uF Pany FA. The BG's don't seem to get along with the Auricaps when bypassed.
 I will post a pic as soon as the battery is charged for my camera.

  Quote:


 What I've discovered is that John has a lot of information in the manual and in his archives of his blog. The trick is finding it. 
 

Do share
	

	
	
		
		

		
		
	


	




.


----------



## digger945

This is the exact schematic I used for the upgrade:





 ...and the link to the tubecad page I found it. I should say that to do this mod, three traces must be cut on the underside of the pcb(the old pcb I have), to isolate the gates in the mosfets. Once the traces are cut, I just soldered the 300ohm resistors from ground to the gates. Boilermaker, you must have the latest pcb with the two sets of mounting holes for regs/mosfets.


----------



## BoilermakerFan

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_I soldered two pieces of 18ga strand to the pcb and use alligator clips and test leads to try out different caps in the C3 position. C4 is soldered in for now, and I have tried the BG NX 25V 1000uF (included when I bought this amp from Fierce Freak) and now I run a 16V 4700uF Pany FA. The BG's don't seem to get along with the Auricaps when bypassed.
 I will post a pic as soon as the battery is charged for my camera._

 


 Your experiences bypassing BGs mirrors those of builders with MHMs too. 

  Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_Do share
	

	
	
		
		

		
		
	


	




._

 

Specifically, what do you want me to share? In his blog posts or in the on-line store is where he mentioned using a selector switch to swap between the different caps. He'll mention a snippet here or there in a blog post and you have to check the schematics to see if it will work with the PCB, etc...

 Here is the blog entry with the resistor value for bias on the 10M45S: 
A New High-Voltage Regulator

 And the specific table:





 I emailed John about the differences for setting bias on the DH2540 versus 10M45S... Hopefully I'll hear back from him within the week. 
	

	
	
		
		

		
		
	


	





  Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_This is the exact schematic I used for the upgrade:





 ...and the link to the tubecad page I found it. I should say that to do this mod, three traces must be cut on the underside of the pcb(the old pcb I have), to isolate the gates in the mosfets. Once the traces are cut, I just soldered the 300ohm resistors from ground to the gates. Boilermaker, you must have the latest pcb with the two sets of mounting holes for regs/mosfets._

 

Yes, I have the latest PCB and was one of the lucky 7 to get a Aikido 24V kit with the NOS Amperex Holland 6GM8 tubes and his 24V PSU kit. 

 John has been very helpful answering my questions regarding the 24V with other FETs for the buffers too, it just takes a long time to get an answer most of the time.


----------



## digger945

So are you listening to your amp now? 
 What source are you using?
 I think that manaox sent me a PM and said that he maybe found a few amperex tubes somewhere. I would like to try these out, as 6N27P doesn't return any results on google anymore.
 With my current setup on the amp, it's about as forward as I have listened to yet. Let me see if the battery is charged for the cam yet.


----------



## digger945

I've tried a 3uF Sonicap and some 10 & 24uF motor run's also.


----------



## BoilermakerFan

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_So are you listening to your amp now? 
 What source are you using?
 I think that manaox sent me a PM and said that he maybe found a few amperex tubes somewhere. I would like to try these out, as 6N27P doesn't return any results on google anymore.
 With my current setup on the amp, it's about as forward as I have listened to yet. Let me see if the battery is charged for the cam yet._

 

Nope. It's still in parts in the box it arrived in... Long story, but I'm still in the process of setting up my workbench in the basement to begin building. I have 3 MAXes, the Aikido, and a dual mono AudioSector LM3875 gainclone amps to build as well as two phono stages, 4 OptiVols,and Shigaclone CD transport... And that is just the electronics. I'm waiting for a box of Grado headbands to show up so I can start making some prototype ortho cans too.


----------



## digger945

How long does it take to get to Evansville? LOL.
 Yea, I gotta few long stories too. It will be interesting to see how it goes with manaox's bal. build.

 I really like this amp, I wanna try some more different designs, just don't wanna electrocute myself do death LOL.


----------



## fran

I;ve been searching for ages for some 6N27P - trying ebay every now and then and so on. Never could find any. So turns out someone else spotted and bought some from a canadian ebay seller, nixietubes, but also turns out he wants $90 for a set of 4. Just too rich for me when I already have 24 6GM8 of various sources. Maybe I should sell a few of the 6GM8 and buy a set, but not until I hear solid reports on sonics.

 Fran


----------



## BoilermakerFan

Quote:


  Originally Posted by *fran* /img/forum/go_quote.gif 
_I;ve been searching for ages for some 6N27P - trying ebay every now and then and so on. Never could find any. So turns out someone else spotted and bought some from a canadian ebay seller, nixietubes, but also turns out he wants $90 for a set of 4. Just too rich for me when I already have 24 6GM8 of various sources. Maybe I should sell a few of the 6GM8 and buy a set, but not until I hear solid reports on sonics.

 Fran_

 

Email John and ask for a report... I suspect he has at least heard them in an Aikido.


----------



## BoilermakerFan

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_How long does it take to get to Evansville? LOL._

 

Depends are where you are in IN... Ft. Wayne and South Bend are 6 hours or so, Indy is 3 hours.


----------



## digger945

6N27, the hunt is on.
 I have though for a long time about just doing a ptp Aikido with a different tube, say 48V or something. 
 I just bought 4 of the 19J6 "starving student" tubes, maybe I will give it a try.


----------



## BoilermakerFan

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_6N27, the hunt is on.
 I have though for a long time about just doing a ptp Aikido with a different tube, say 48V or something. 
 I just bought 4 of the 19J6 "starving student" tubes, maybe I will give it a try._

 

If you are going to go P2P, then you could also step up to octal tubes like the 6SN7 and just run it at the lower voltage, maybe use 48VAC on the secondaries and rectify up from there... There is also the 12BH7 to try at 48V in the PCB... 

 A great fellow Head-Fi'er sent me a huge box of assorted oddball tubes or RF tubes. Many of the non-RF tubes are primarily designed for TV beam power applications, but I know a few guys on diyAudio who have had great success with some "TV" tubes. The RF tubes are 12BA6 and such for refurbishing my old consoles. One that I need to see if I can tame in an Aikido is a metal can 12SQ7. Gain of 100 but it can be run at a plate voltage of 100V so it might have some promise with a beam tube as a buffer. I really need to sort through them and figure out which ones have the most potential and toss the dead or broken ones.


----------



## manaox2

I have two Millett Max (two mini-max and two max PCB) kits, two SS millett kits, two Alien DAC kits, the dual mono Opus, metronome, ballsie needing to be wired and cased, Buffalo and Ivy module kits, and now this. I am working on the SS Millett and completing the Opus to bid time until I complete the parts orders for the Aikido and have my Christmas vacation to work on them. 
	

	
	
		
		

		
			





 I really need to order some new cases and do some case work. I feel pretty lazy since have the drill presses and bandsaws available with nothing done. 
	

	
	
		
		

		
		
	


	




 Time for a new head-fi group. "DIY: Do It Yet?"


----------



## BoilermakerFan

I received a reply from JRB regarding the DN2540...

 "The DN2540N5 is pinout compatible with the 10M45S, but setting the same idle current will require a different source resistor value (and probably some tweaking). Note how the Idss (the idle current with the gate tied to the source with no source resistor) is a tad over 300mA; this sets the maximum limit to current conduction (as configured with a source resistor). Also note how having the source sit 0.5V above the gate voltage results in an idle current of about 100mA. A 5-ohm resistor would develop a 0.5V drop with 100mA flowing through it. In other words, start at about 10 ohms and work down to the desired idle current."

 So digger, your DN2540s should be sitting at 100mA bias and the default LM317s when using John's recommended 20ohm resistor value are running with 60-65mA. So that does explain why your DN2540 is so much hotter. Unfortunately, I think I forgot to order 10ohm resistors and I'd have to have 3 positions for resistors on a selector switch. I might just drop in two 1K trimmer pots and measure the resistance across the trimmer once it's installed to set them to the different values per a recommendation to me by another designer... Switching out buffers won't be as fast, but I'll have a lot more flexibility in trying different bias levels with all of the buffer options until I find a favorite or two. Once I figure that out, then I'll go back and replace my critical resistors with better Mills or Caddocks.


----------



## digger945

Hey thanks for the info Boilermakerfan, the 317's never run as hot as the 2540's though, even with 2.5 ohms on the source(output pin on the 317). As for the source voltage being 0.5V above the gate, I'm at 1.3V now(the red approx. 1V on the schematic) and for the approx. 8vdc(positive side of output caps) on the schematic, I have 13.2. 




 I suppose it doesn't matter much, as the AC signal is the only thing passed by the output coupling.
 I'm ordering some more reg's tonight from mouser to try, and I just bought two 9-pin mono Aikido boards and some tubes on the FS forum here to play with.


----------



## BoilermakerFan

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_Hey thanks for the info Boilermakerfan, the 317's never run as hot as the 2540's though, even with 2.5 ohms on the source(output pin on the 317). As for the source voltage being 0.5V above the gate, I'm at 1.3V now(the red approx. 1V on the schematic) and for the approx. 8vdc(positive side of output caps) on the schematic, I have 13.2. 




 I suppose it doesn't matter much, as the AC signal is the only thing passed by the output coupling.
 I'm ordering some more reg's tonight from mouser to try, and I just bought two 9-pin mono Aikido boards and some tubes on the FS forum here to play with._

 

Hmmm... I don't know what to tell you on your readings. 

 Which regs do you plan to order? John sent me the LM317s and a pair of 10M45S since I had already discussed using the the IRF510, IRF610, and IRFX35 FETs with him. I do have the LM350s and LT1085 too so I'll role those into the various sockets with the other reg combos. I also ordered another DN depletion-mode FET, but I can't remember the number and now I'll have to go to the data sheets to compare them to the 2540s and determine the correct resistor. I still suspect I'll end with the 10M45S feeding the IRF510 based on reports comparing the 510s, 610, and X35s in other amps... 

 I'm also going to put the 510/9510 and 610/9610 pairs in the DBs for my MOSFET-MAX as well, just see how it sounds. Luckily I have the big 2-1/2" heatsinks for the MAX so I can bias up to 175mA or 200mA without toasting the FETs. It did require a major overhaul of many of the other components though since the currents go up through the entire MAX. That should put the MAX's output over 1.1 watts. 
	

	
	
		
		

		
		
	


	




 Anybody looking for matched sets of 5087/5088 transistors? LOL! I have at least 6 sets that I won't be using now....


----------



## digger945

I have decided to hold off on the mouser order for now. The 1085 would be my first pic, but I will definitely be trying some other regs like the 350.
 I gotta say boiler, the 317's are just as good as the 2540's to me, the only reason I did the 2540's is for a little current boost for the 25ohm Denons, and they do seem to have better control on the bottom end.
 I did buy some 5087/8's when I ordered the 2540's, and I think that I will also try one of JB's buffer's on an seperate board.
 No doubt, the Aikido is the most fun tinkering I have had in a long time.


----------



## BoilermakerFan

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_I have decided to hold off on the mouser order for now. The 1085 would be my first pic, but I will definitely be trying some other regs like the 350.
 I gotta say boiler, the 317's are just as good as the 2540's to me, the only reason I did the 2540's is for a little current boost for the 25ohm Denons, and they do seem to have better control on the bottom end.
 I did buy some 5087/8's when I ordered the 2540's, and I think that I will also try one of JB's buffer's on an seperate board.
 No doubt, the Aikido is the most fun tinkering I have had in a long time._

 

I only ordered two of the 1085s as I plan to use the 317s or 350s in the first position. John included the 317s in my kit because he felt so strongly about how great they sound in the application. With the components I have for the buffers in the Aikido I have 12 combos to try and I eventually want to try the 12BH7 tubes too, even though it means swapping out 7 parts (4 resistors, 3 caps). I also have extra VitQ caps try try at C3 in addition to the RTLs included. I'll probably add a set of motor run caps to the build too.

 The MAX should be really fun too. I have 3 boards, 5 sets of boutique caps, and 14 combos of DBs. Plus one will be a MOSFET-MAX, so a few of the transistors will be JFETs instead of BJTs, that will influence the sound when used with BJT buffers. Then there are the 3 different tubes... 

 I'll have 5 different sets of headphones soon enough too, so a lot of tinkering for me in the near future. 
	

	
	
		
		

		
		
	


	




 After all the dust (hopefully no sparks or smoke!) settles I'll then build an Octal based Aikido 48V or 72V as a P2P build with some of my oddball tubes. 

 BTW, where in Indiana are you?


----------



## digger945

South Bend, Mishawaka to be exact.


----------



## rodentmacbeastie

Quote:


  Originally Posted by *fran* /img/forum/go_quote.gif 
_I;ve been searching for ages for some 6N27P - trying ebay every now and then and so on. Never could find any. So turns out someone else spotted and bought some from a canadian ebay seller, nixietubes, but also turns out he wants $90 for a set of 4. Just too rich for me when I already have 24 6GM8 of various sources. Maybe I should sell a few of the 6GM8 and buy a set, but not until I hear solid reports on sonics.

 Fran_

 

Fran,
 I am awaiting all of the parts for my Aikido to go with the Reflektor tubes I got from this guy. The Buffalo is on the way, and I am building the D! later as well. Between the two of us we should get it figured.


----------



## digger945

Boilermakerfan,
 I forgot to mention, when I installed the 2540's, I left out the low pass filter between the tubes and buffer, actually just lifted one end of the cap(300pF) from the board. Well I just hooked it back up, and can notice a little more clarity across the board, especially with my fav tunes.


----------



## fran

rodentmacbeastie: thats good. Let us know how you get on with the reflektor tubes. You'd imagine taht there would be a seller inside russia with those tubes that would be a hell of a lot cheaper......

 Fran


----------



## BoilermakerFan

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_Boilermakerfan,
 I forgot to mention, when I installed the 2540's, I left out the low pass filter between the tubes and buffer, actually just lifted one end of the cap(300pF) from the board. Well I just hooked it back up, and can notice a little more clarity across the board, especially with my fav tunes._

 

Ah, good to know, but I planned to keep that in place...


----------



## rodentmacbeastie

Quote:


  Originally Posted by *fran* /img/forum/go_quote.gif 
_rodentmacbeastie: thats good. Let us know how you get on with the reflektor tubes. You'd imagine taht there would be a seller inside russia with those tubes that would be a hell of a lot cheaper......

 Fran_

 



 I have been talking to a master woodworker that is working in the house I am laquering about this. His brother in Poland has seen lloads of tubes in repair shops there and I have asked to see if he can be persuaded to go on a hunt for them. If anything comes of this Fran, I will post it here. However, it will take time.

 Rodent


----------



## manaox2

I checked about three russian dealers and found a few with the goods. The cheapest though was 19.80 before shipping from Russia. They make the ebay deal look very fair and good. Someone should email globex.com.ru to get a quote on theirs still.


----------



## digger945

Just wanted to say, I changed R20/21 from the recommended 300Ω shown on the schematic back to the original 10KΩ shown on the original 24V schematic. I don't think that the 300 mated well with the 200pF cap to form the low pass filter between the tube and 2540 circuits. 
 Now I got the incredible space and detail/depth back that was before(I knew something was wrong), much more forward.

 I would like to know if I used the recommended 300Ω resistor for R20/21, what value cap should be used to complete the filter?

 EDIT: It is unreal how much difference was made with this one little resistor!!!


----------



## fran

Is the cap you're talking about C2 on the board? I think.... just think that they are 330pF wima in my build. I can't read the writing on the caps - the heatsinks on the LM317 are in the way, but I think I used some 330pF that I had for this.



 I've always had R20 and 21 at 10K - I just had a look there now (hope I'm reading the colours right, my DMM is outside in the workshop! brown black black red gold).

 Always loved this amp, thought and still think its the best I've heard yet.

 Fran


----------



## BoilermakerFan

The Rev A manual has the Low-Pass filter as R19/R20 and recommends 10K now, though the range is 1K-10K in the BOM... C2's recommended value is 100pF to 300pF in the Rev A manual. I deleted the PM I sent manaox2 with the value of C2 that is in my kit and have it stashed away for now...

 I'm considering an alternate hybrid Aikido at 96V with a separate heater supply to allow the use of some other tubes that sound good at 100V. It would be a P2P project and I would probably set up the wiring to allow 24V, 48V, 96V, and 192V B+ voltages. The switch would be located inside the chassis so I would have to physically remove the cover to access the switch and change tubes. Actually, it would have two switches, one for the B+ and one for the separate heater voltage... It will need to wait until after I get the first one built and try it with the 6GM8 tubes and all the buffer options.


----------



## digger945

Yea, I think I am gonna try something high voltage with the 9pin mono boards I bought. I would really like to do one with tubes that are stout enough to drive 25Ω Denons with ease. 
 That would be trick to have a PS with that kind of adjustment to sample a variety of tubes.
 Now some research into a good tube candidate for my first try.
 Still can't believe the difference from just that one resistor. Sounds better than ever.
 Gonna be sorely dissapointed if a HV version doesn't sound better.


----------



## rodentmacbeastie

Quote:


  Originally Posted by *fran* /img/forum/go_quote.gif 
_Always loved this amp, thought and still think its the best I've heard yet.

 Fran_

 

That is what I like to hear! I am making this my last build. The only thing that may change is the buffer. I will try the FirstWatt F1 I am building for the speaker with my cans first... If it is marginally better I will build two. The other idea I am having about high voltage tube is why would you not run it at 300 volts for the B+, seperate PS for the heaters and buffer? For those looking at point-to-point, why not build with 300v and just build the buffer seperat with it's own PS or a scaled down F1? I believe that while the buffer on board may be great and simple, but a FirstWatt F1 current amp should truly make the HD650 mirrors of the DAC and preamp. I don't even know if you would have to change much. There is a lot on DIYaudio.com about a F4 buffer scaled down for cans. I believe that the F1 may be the best amp for full range drivers ever made. It is amazing the grip it has on the driver and the design does not really allow color to be introduced by it. I would not do the F1 alone without a tube preamp or DAC/CD, it does show how bad an opamp sounds in comparison to a good discrete stage.


----------



## digger945

^^^This is what I have in mind.
 My buffer will be a Dynamite(only lacking Toshibas at this point).
 Give us some good tube suggestions.


----------



## rodentmacbeastie

If I was going high voltage I would use 6SN7GT/12SN7GT for the headphone board. This would be with the assumption that you can wire a different B+ for the buffer and tubes. If I was going p-t-p or normal boards with and outboard buffer I would use the same as above for the driver tube and a a 6N6P/6H30Pi for the buffer. This combination would drive cans without a SS buffer. However, if I was going this route I would still build a buffer. I think that the 6SN7GT is my favorite tube and I have never had a component with them in. Just from hearing some in my system one time. The 12SN7GT is the same tube with 12v heaters and about 15% of the price. You have got a lot of tubes to roll as well with these and I don't think you will be dissapointed. In fact, four 12SN7GT tubes and a FirstWatt F1 for a buffer might be as closet to the perfect amp as possible. You could jumbper the high volt to the 24V buffer for a more exact comparison as well. If you build it with some blackplate 12SN7GT's and it does not sound any better than the 6GM8's, the 24V will be the last amp I ever build. I could see this being the case. The low volt tubes may sound better given a light load like a buffer. It might not be an even race if you tried to remove the buffer. I wonder what the 6GM8 sounds like at 30v?


----------



## digger945

6H30Pi huh.
 I've read some good things about this one.
 Yea I read luvdunhill's remark in your BOX'O'GOODIES thread.
 Interesting, 6H30 can be had for $100 for set of 4.
 dsavik's comments:High voltage is better in general. Can't comment on the Aikido, though.
 Reading your other thread about 6gm8 vs 6h30.


----------



## BoilermakerFan

Quote:


  Originally Posted by *rodentmacbeastie* /img/forum/go_quote.gif 
_That is what I like to hear! I am making this my last build. The only thing that may change is the buffer. I will try the FirstWatt F1 I am building for the speaker with my cans first... If it is marginally better I will build two. The other idea I am having about high voltage tube is why would you not run it at 300 volts for the B+, seperate PS for the heaters and buffer? For those looking at point-to-point, why not build with 300v and just build the buffer seperat with it's own PS or a scaled down F1? I believe that while the buffer on board may be great and simple, but a FirstWatt F1 current amp should truly make the HD650 mirrors of the DAC and preamp. I don't even know if you would have to change much. There is a lot on DIYaudio.com about a F4 buffer scaled down for cans. I believe that the F1 may be the best amp for full range drivers ever made. It is amazing the grip it has on the driver and the design does not really allow color to be introduced by it. I would not do the F1 alone without a tube preamp or DAC/CD, it does show how bad an opamp sounds in comparison to a good discrete stage._

 

Going to separate Aikido boards and feeding to separate headphone buffer isn't really an Aikido 24V anymore. 
	

	
	
		
		

		
		
	


	




 Though it does allow the use of octal tubes and other buffers like the F1. My biggest reason for going off the 24V PCB would be for better heatsinking of the buffers, then you can up the voltage to them and the current and have a very serious driver for just about headphone and it should be staggeringly good at driving orthos. I also plan to send the signal out to a Pass amp design, or a SKA amp... I'll end up building both... Speakers will be a set of Fonkens and Elsinores (again, just trying to decide which to build first, the Fonkens are in the lead though). The 

 The Aikido 24V board is more than capable of supporting 300V for the B+ voltage and John has a separate section in the Rev A manual addressing HV builds with recommended PSU/Heater configs as well as BOM values for 12AU7 (150V), 6CG7 (200V), and 6DJ8/6922 (100V). The 6H30 can also be used, but the BOM values aren't listed but he does recommend 170V for the B+. I have (21) 12AU7s that are actually allocated to JRB's Aikido PH-1 phono stage for after the RIAA equalization, so I'll just cherry pick four tubes out of those for the Aikido 192V.


----------



## rodentmacbeastie

Has anyone tried to use the headphone out for a pre out and compared the two on speakers yet? I mean has anyone connected the HP out and the PRE out on the 24V board to two inputs on the speaker rig and done A/B switching to see if the buffer aids the tubes or not in that role? I think that in some system the HP out might help with impedance mismatches and the extra dynamics might be a boon?


----------



## digger945

I think maybe fierce freak tried it.


----------



## BoilermakerFan

Quote:


  Originally Posted by *rodentmacbeastie* /img/forum/go_quote.gif 
_If I was going high voltage I would use 6SN7GT/12SN7GT for the headphone board. This would be with the assumption that you can wire a different B+ for the buffer and tubes. If I was going p-t-p or normal boards with and outboard buffer I would use the same as above for the driver tube and a a 6N6P/6H30Pi for the buffer. This combination would drive cans without a SS buffer. However, if I was going this route I would still build a buffer. I think that the 6SN7GT is my favorite tube and I have never had a component with them in. Just from hearing some in my system one time. The 12SN7GT is the same tube with 12v heaters and about 15% of the price. You have got a lot of tubes to roll as well with these and I don't think you will be dissapointed. In fact, four 12SN7GT tubes and a FirstWatt F1 for a buffer might be as closet to the perfect amp as possible. You could jumbper the high volt to the 24V buffer for a more exact comparison as well. If you build it with some blackplate 12SN7GT's and it does not sound any better than the 6GM8's, the 24V will be the last amp I ever build. I could see this being the case. The low volt tubes may sound better given a light load like a buffer. It might not be an even race if you tried to remove the buffer. I wonder what the 6GM8 sounds like at 30v?_

 

If you are going to use the Aikido 24V schematic, then the four tubes have to all be the same due to the heater current draws. Going to separate boards and separate supplies for all 4 boards allows you to mix and match. 

 The 12SN7GT gets my vote too for octal, but the 6H30P is probably one of the best noval options for lower gain. I'm looking at 6N1P and 6H27P too, but their gain is higher. 

 There is another huge advantage of 12V heaters over 6V for the same tube family, reduced current, so lower noise! That is assuming the quality of the 12V heater tubes is equal to the 6V version. If I could just find a great medium mu tube with 50V heaters than the Aikido HV would be very easy to implement at 200V...


----------



## digger945

^I've read JB talk up the 12V 5687 for this reason, and says it is a very robust medium mu tube.
 Yea, 4 boards in balanced config would allow for two different heater voltages.


----------



## rodentmacbeastie

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_6H30Pi huh.
 I've read some good things about this one.
 Yea I read luvdunhill's remark in your BOX'O'GOODIES thread.
 Interesting, 6H30 can be had for $100 for set of 4.
 dsavik's comments:High voltage is better in general. Can't comment on the Aikido, though.
 Reading your other thread about 6gm8 vs 6h30._

 



 I would start with a set of 4 RCA 6FQ7/6CG7 blackplate clear tops from the 50's. The 6CG7 is essentially a 6SN7 with a nine pin and a shield. It does not sound as good as the best 6SN7GT's though. If you are needing more try using an adaptor or rewire an octal socket in the first position with everything else the same and get some "Bad Boy" 6SN7GT Sylvania's. They are not cheapp, but you can resell them later if it does not work out. If a little time passes you might even make a couple of bucks of them. If that is what you are after you can do a couple of things. You could leave it the way it is. You could sell the "Bad Boys" or the top tube you had chosen, switch the heaters to 12.6v and buy the same tubes for 5 times less! However, if you wish to stay noval...

 1. RCA blackplate cleartop in all for positions if using the 24V boards.
 2. If using noval Aikido, I would try the RCA 6GC7 cleartops inthe dirver and a 6N6P in the buffer.

 OCTAL:

 3. I would use 12SN7GT all around.
 4. P-T-P, I would use option #3 if the impedance they are driving is high, like a buffer. If the impedance is low, or you want the tubes to drive cans I would use the 12SN7GT followed by the 6N6P.

 Option 3 is the way I would go if I was to try high voltage. In fact, if you can seperate the PS for the tubes and the buffer on the 24V board I will build a SE all 6CG7 clear top and a SE 6GM8 on the 24V boards I am getting to build my balanced 24V. I have real Telefunken and Reflektor tubes to try in the 24V and I can get some clear top 6CG7. I will use the 24V supply to dive the 24v amp and the heaters and buffer on the high volt board. I can use a Twisted pear OTTO I was going to use for a phase reversal switch at a later date and wire a switch for A/B comparisions. I will buy some Sowter 1:1 transformers to do the SE conversion on the Buffalo DAC. I will then sell the Aikido that loses, buy another board and build the other channel of my balanced rig. If the high volt wins I will use adaptor to convert it to 12SN7GT I will do all of this... in time. LOL!

 No really, this is going to be the last project for a very long time so I will start as soon as the Aikido boards arrive. It will take some time, but I am on it.


----------



## digger945

Last project , right.
 I gotta go put pajama's on my cat, it's time for bed.



 Your post has been printed and put in the "Aikido file".
 Thanks rodent, and BMfan also.
 Tomorrow.


----------



## BoilermakerFan

Quote:


  Originally Posted by *rodentmacbeastie* /img/forum/go_quote.gif 
_<snip>
 Option 3 is the way I would go if I was to try high voltage. In fact, if you can seperate the PS for the tubes and the buffer on the 24V board I will build a SE all 6CG7 clear top and a SE 6GM8 on the 24V boards I am getting to build my balanced 24V. <snip>_

 

The Aikido 24V board requires all four tubes to be identical. The SS buffers run at the same voltage as B+, but the heaters can be powered by a separate supply to run at 6V, or 12V, or even 50V... When you go above 24V on the B+ the SS buffer switches over to the 10M45S and a HV MOSFET since they are rated to 450V. 

 I don't see why you couldn't send the headphone buffer output to a power amp as well. That is how the Millett Hybrid MAX is setup to run.


----------



## manaox2

Quote:


  Originally Posted by *BoilermakerFan* /img/forum/go_quote.gif 
_The Rev A manual has the Low-Pass filter as R19/R20 and recommends 10K now, though the range is 1K-10K in the BOM... C2's recommended value is 100pF to 300pF in the Rev A manual. I deleted the PM I sent manaox2 with the value of C2 that is in my kit and have it stashed away for now..._

 

 Quote:


  Originally Posted by *BoilermakerFan* 
_OK, per the Rev. A manual and the labels on the kit bags:
 C1: 1uF 400V R.T.I. poly cap, #F10068-105
 C2: 100pF little mica caps
 C3: 0.33uF 400V R.T.I. poly #F10068-334
 C4: 1800uF 25V Pan. FM
 C5, C6: Not included, optional, using shorting jumper
 C7-10: 1800uF 25V Pan. FM
 C11: 1800uF 35V Pan. FM
 C12: 3.3uF 160V Wima MKP cap
 C13 0.68uF 250V Wima MKP cap_

 







 You guys gave me a lot to read before sleeping tonight.


----------



## BoilermakerFan

Thanks manaox2, didn't realize I had cleared out my sent PM folder to make room... Your envelope went out Saturday First Class mail in a padded envelope.


----------



## manaox2

Quote:


  Originally Posted by *BoilermakerFan* /img/forum/go_quote.gif 
_Thanks manaox2, didn't realize I had cleared out my sent PM folder to make room... Your envelope went out Saturday First Class mail in a padded envelope._

 

No prob. Your money order also went out Friday afternoon in a 42 cent postage envelope.


----------



## rodentmacbeastie

What is the highest the low volt regulators can run at? When we started talking about tubes, someone mentioned 12SX7GT. Is this not the legendary tube that bests ANY 6SN7GT? Don't they run as low as 48V?


----------



## digger945

^ I remember reading about the SX tube you refer to, just don't remember where. Prolly on TCJ somewhere. Isn't it supposed to be of the "space tube" variety?...like the 6GM8. 

 I recieved the Amperex Bugle Boy 6GM8's today, boy howdy, I know what all the hubbub is all about now, these things stomp a mudhole in a Siemens tube all day long, most especially on the bottom end definition and power, all across the board really. These tubes have the halo at the top, as do the other 6 that came in original boxes.

 I think that I may have been wrong when I mentioned a few posts back about running 4 mono boards in balanced config and having the ability to use two different heater voltage tubes. I dont think that two different heaters can run on one board without cutting traces and modding a little bit.

 Manaox, you ain't gonna believe these tubes man!(I haven't even tried out the ones in the original boxes yet)
 I'll put up some pics in a bit for all to see.


----------



## BoilermakerFan

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_snip>
 I recieved the Amperex Bugle Boy 6GM8's today, boy howdy, I know what all the hubbub is all about now, these things stomp a mudhole in a Siemens tube all day long, most especially on the bottom end definition and power, all across the board really. These tubes have the halo at the top, as do the other 6 that came in original boxes.

 <snip>

 I'll put up some pics in a bit for all to see._

 

Where's the pics? :-D


----------



## digger945




----------



## digger945




----------



## digger945

I really gotta figure out how to do thumbnails.


----------



## digger945

Pic of the 2540, legs crossed.


----------



## digger945

The amperex boxes.


----------



## digger945

Wait, I think we have an A frame in the bunch, only one.


----------



## rodentmacbeastie

I believe the 12SX7GT is a "space" tube that is meant for directional radar in planes to run off 26.5v. This is why I want to try them with the existing 24V set-up. They are one of the best sounding tubes period and the sections are matched very closely, especially for 6SN7GT's.


----------



## manaox2

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_Manaox, you ain't gonna believe these tubes man!(I haven't even tried out the ones in the original boxes yet)
 I'll put up some pics in a bit for all to see._

 

Ah, that is such great news, I really want to hear these now! 
	

	
	
		
		

		
		
	


	




 I'm going to test my boards SE with them, though I think there was a slight mix up in a revision of my H-PS-1 boards I ordered that would cause a ground short, so John is working on sending some replacements.


----------



## digger945

rodentmac,
 Do tell us more about the "space tube". Are these the same as the 12SN7GT?
 Have you read of a fav brand? RCA, GE, etc.
 Do you have any leads on pricing?(We wont require you to divulge your sources, lol)


----------



## BoilermakerFan

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_rodentmac,
 Do tell us more about the "space tube". Are these the same as the 12SN7GT?
 Have you read of a fav brand? RCA, GE, etc.
 Do you have any leads on pricing?(We wont require you to divulge your sources, lol)_

 

The usual suspects have them for $20-$24 a tube, unless you want to buy a case of 100 NOS RCAs, then they are $17 each. 
	

	
	
		
		

		
			





 My 6GM8 tubes from John are Amperex Holland, but they aren't Bugle Boys...


----------



## digger945

I found these on a foreign ebay page. Look familar, he only has one matched pair.
 Claims to be "red falcon" from West German stock.
 EDIT: I finally got this page in english, the sale has ended. Sure are strange looking guts in these ones.


----------



## digger945

Boilermakerfan, 
 So your saying that these tubes can be had for about the same price as 6gm8's(when you can find them). 

 I didn't get to finish listening to the game this weekend, who won?


----------



## BoilermakerFan

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_Boilermakerfan, 
 So your saying that these tubes can be had for about the same price as 6gm8's(when you can find them). 

 I didn't get to finish listening to the game this weekend, who won?_

 

AES has them for $24. Not sure if anyone else has stock... 

 Those look like the RCA flat plates...

 Iowa, 22-17.


----------



## BoilermakerFan

Comments on the 12SX7GT are on both pages:
http://www.head-fi.org/forums/f5/12s...mments-146617/

 Scored a working Heathkit IT-17 tube tester on that auction site last night for $50 and it shipped from Louisville today so I'll have it tomorrow. No curve traces, just a fast Go-No Go tester for this huge box of tubes (and my old Magnavox console) I have so I can quickly sort duds. After that I can inventory my collection. 

 Which tubes do you think will sound better in the Aikido, 6GM8 or 12AU7A? I have 21 of the 12au7a tubes, but 3 are oddities with different getters. Most are RCA with round getters. I'll let you guys know how many are still good after tomorrow night if anyone is interested in a trade for other tubes like 6dj8 or 6cg7.


----------



## rodentmacbeastie

What needs to be done to convert this thing to 48V? I think that having a 24/48v power supply would let you use 12bh7 and 12sx7. Confirmed, the 12sx7 is meant to run at 28v. The only issue is the ss regs.


----------



## BoilermakerFan

Quote:


  Originally Posted by *rodentmacbeastie* /img/forum/go_quote.gif 
_What needs to be done to convert this thing to 48V? I think that having a 24/48v power supply would let you use 12bh7 and 12sx7. Confirmed, the 12sx7 is meant to run at 28v. The only issue is the ss regs._

 

Note, my reply is based on the REV. A manual...

 For the 12BH7 R2, R4, R8, R11 change to 249ohm. C4 changes to a value range of 330uF to 2,200uF at 50V and all the other caps need to be rated at least to B+. So you could always move them up to a 200V or 300V rating across the board and cover yourself from the beginning. I think a nice quality selector switch or even a Darwin could be re-purposed to provide multi-voltage resistor values for each tube or PSU voltage.

 A doubled VA 24VAC/6.3VAC dual secondaries toroid for series/parallel 24/48 connections with removable links could be used in conjunction with a LM317AHVT (to 57V) as the Vreg to allow only one B+ and one heater voltage through to the board(s). A more elaborate PSU is needed for 100V/200V/300V B+ supply.


----------



## Coreyk78

I apologize if my question here has already been answered somewhere else in the thread, I admit I haven't read even close to all of it yet.

 Anyway, I'm very interested in building one of these primarily to use it as a tube preamp to drive my speaker amp. I was going to try building it using a cheap 24v dc switching power supply, like one for an lcd monitor or printer or something. But then I got the idea that it would be nice to build it with a phono section in the same chassis using the Very Simple Phono Stage design from RJM audio found here RJM Audio - The Very Simple Phono Stage and using a rotary selector switch to use the Aikido with several other sources.

 The thing I don't know yet is how to get the voltages I need. Of course I would need +24v for the Aikido but then I also need +12v and -12v for the phono stage. I'm thinking there must be a way to get these using only 1 transformer but I don't know how. Would I be able to use a 24v series/12v parallel secondaries transformer?

 I'm still pretty new at the DIY electronics game, but I learn quickly and am looking for some advice on what would be the most efficient way to power this stuff. I'm very early in planning how to make this work so I am open to any suggestions, I'm also going off the assumption that I only need a single +24v source to feed the Aikido, thats what I gathered from reading the original design article, so please correct me if I'm wrong. Thanks in advance!


----------



## BoilermakerFan

Quote:


  Originally Posted by *Coreyk78* /img/forum/go_quote.gif 
_I apologize if my question here has already been answered somewhere else in the thread, I admit I haven't read even close to all of it yet.

 Anyway, I'm very interested in building one of these primarily to use it as a tube preamp to drive my speaker amp. I was going to try building it using a cheap 24v dc switching power supply, like one for an lcd monitor or printer or something. But then I got the idea that it would be nice to build it with a phono section in the same chassis using the Very Simple Phono Stage design from RJM audio found here RJM Audio - The Very Simple Phono Stage and using a rotary selector switch to use the Aikido with several other sources.

 The thing I don't know yet is how to get the voltages I need. Of course I would need +24v for the Aikido but then I also need +12v and -12v for the phono stage. I'm thinking there must be a way to get these using only 1 transformer but I don't know how. Would I be able to use a 24v series/12v parallel secondaries transformer?

 I'm still pretty new at the DIY electronics game, but I learn quickly and am looking for some advice on what would be the most efficient way to power this stuff. I'm very early in planning how to make this work so I am open to any suggestions, I'm also going off the assumption that I only need a single +24v source to feed the Aikido, thats what I gathered from reading the original design article, so please correct me if I'm wrong. Thanks in advance!_

 

I would avoid a switching PSU, especially for a phono stage, just too much noise...

 I am building Peter Daniel's modified version of the VSPS:
diyAudio Forums - AudioSector-chip amp kits, dacs, chassis - Page 75
diyAudio Forums - AudioSector-chip amp kits, dacs, chassis - Page 63

 Peter's PSU is based on a 50VA Hammond 229D24 transformer which has dual 12Vac secondaries or 24Vac when wired in series. You can use a 50VA 12Vac dual secondaries toroid from AnTech and save some money to also buy a 100VA 24Vac dual secondaries toroid for the Aikido so you can wire the secondaries in parallel for 24Vac or series for 48Vac later. 50VA would be big enough for the Aikido, but I like the idea of having extra headroom in the transformer at 24Vac and keeping the higher current available at 48V though the LM317 v-reg is limited to 1.5A. Buy the HV version of the LM317 and your covered for both 24V and 48V Aikido builds in the future. 

 See Peter's PSU design for the phono stage and use John's PSU for the Aikido. Keep the two on separate PSUs to minimize the noise in the phono stage.


----------



## Coreyk78

Quote:


  Originally Posted by *BoilermakerFan* /img/forum/go_quote.gif 
_I would avoid a switching PSU, especially for a phono stage, just too much noise...

 I am building Peter Daniel's modified version of the VSPS:
diyAudio Forums - AudioSector-chip amp kits, dacs, chassis - Page 75
diyAudio Forums - AudioSector-chip amp kits, dacs, chassis - Page 63

 Peter's PSU is based on a 50VA Hammond 229D24 transformer which has dual 12Vac secondaries or 24Vac when wired in series. You can use a 50VA 12Vac dual secondaries toroid from AnTech and save some money to also buy a 100VA 24Vac dual secondaries toroid for the Aikido so you can wire the secondaries in parallel for 24Vac or series for 48Vac later. 50VA would be big enough for the Aikido, but I like the idea of having extra headroom in the transformer at 24Vac and keeping the higher current available at 48V though the LM317 v-reg is limited to 1.5A. Buy the HV version of the LM317 and your covered for both 24V and 48V Aikido builds in the future. 

 See Peter's PSU design for the phono stage and use John's PSU for the Aikido. Keep the two on separate PSUs to minimize the noise in the phono stage._

 

Fantastic! thanks for the info and links, very helpful. I'm already familiar with Peter Daniel because I built my gainclone with one of his kits so I will definitely read up on his version of the VSPS. 

 The toroids sound like a great idea, and I was planning to order a couple transformers from them soon for the dual mono PA100 LM3886 based amp I am currently working on, so I could probably get the two small toroids in the same box and save the shipping on those. 

 Is the reason for using 48v to get a wider selection of tubes? Or is there some sonic improvement from running the higher voltage?


----------



## digger945

I really dig the idea of the multiple voltage PS. I talked to looser101 the other day and I think maybe I will try something besides the 6H30 on the recently aquired noval mono boards. 

 Glassware is all out of the Octal boards atm(you guys buy em all?), so maybe I will give the 5687 another looking over(gotta buy another pcb of course). The 5687 was my first choice, and there are some attractive tubes in the Cables, etc FS forum, maybe try the Sylvanias or something that Doctorsilantro has up FS.
 Any suggestions for a noval tube to try? I am looking for a stong enough output to drive 25ohm Denons with aplomb.

 I agree with Boiler on the PS issue Corey, I have never had any good results from trying to power one device with two different PS's.


----------



## Coreyk78

Quote:


  Originally Posted by *BoilermakerFan* /img/forum/go_quote.gif 
_ You can use a 50VA 12Vac dual secondaries toroid from AnTech and save some money to also buy a 100VA 24Vac dual secondaries toroid for the Aikido so you can wire the secondaries in parallel for 24Vac or series for 48Vac later. 50VA would be big enough for the Aikido, but I like the idea of having extra headroom in the transformer at 24Vac and keeping the higher current available at 48V though the LM317 v-reg is limited to 1.5A. Buy the HV version of the LM317 and your covered for both 24V and 48V Aikido builds in the future. 

 See Peter's PSU design for the phono stage and use John's PSU for the Aikido. Keep the two on separate PSUs to minimize the noise in the phono stage._

 

Question about using a 24vac dual secondaries xformer for the Aikido, that should be about 33.6vdc after rectification, is the LM317 going to be able to regulate that down close to 24v? That may be a stupid question, but I've never built a regulated PSU before, only unregulated.


----------



## BoilermakerFan

Quote:


  Originally Posted by *Coreyk78* /img/forum/go_quote.gif 
_Question about using a 24vac dual secondaries xformer for the Aikido, that should be about 33.6vdc after rectification, is the LM317 going to be able to regulate that down close to 24v? That may be a stupid question, but I've never built a regulated PSU before, only unregulated._

 

Standard LM317 is good up to 37V, so it will be fine, you actually want a greater voltage delta to keep it running cooler and get better regulation. IIRC, you need at least 3V delta or it will run way too hot and eventually burn out. If you wanted too, you could use 22Vac secondaries just to bring the delta down a little, but the trafo John sent me is a 24Vac secondary. The LM338 will carry 5A, but is only rated to 32V, the LM350 will do 3A with a 33V max input voltage. Dropping to the 22Vac secondaries will sneak in the LM338/LM350 and allow double the current to pass to the amp.


----------



## Coreyk78

Quote:


  Originally Posted by *BoilermakerFan* /img/forum/go_quote.gif 
_Standard LM317 is good up to 37V, so it will be fine, you actually want a greater voltage delta to keep it running cooler and get better regulation. IIRC, you need at least 3V delta or it will run way too hot and eventually burn out. If you wanted too, you could use 22Vac secondaries just to bring the delta down a little, but the trafo John sent me is a 24Vac secondary. The LM338 will carry 5A, but is only rated to 32V, the LM350 will do 3A with a 33V max input voltage. Dropping to the 22Vac secondaries will sneak in the LM338/LM350 and allow double the current to pass to the amp._

 

Thanks again, looking at what Antek has available a 22vac xformer may be the easier choice anyway since they don't have a part# listed for 24vac secondaries in 50 or 100VA sizes.


----------



## BoilermakerFan

Quote:


  Originally Posted by *Coreyk78* /img/forum/go_quote.gif 
_Thanks again, looking at what Antek has available a 22vac xformer may be the easier choice anyway since they don't have a part# listed for 24vac secondaries in 50 or 100VA sizes._

 

I forgot about that. I need to order a 300VA 22Vac for my AudioSector Premium GC kits, a couple different 50VAs for phono stages/CD transports/DACs, and 4 100VAs for the MAXes and Aikido, but my Aikido one will either be 48V secondaries or 100V secondaries since I have a 24V trafo for it already. His shipping is $10 flat fee, so I plan to order a few HV toroids for other tube amp projects too. 

 A Broskie Aikido PH-1 will eventually be built with all 12AZ7A tubes for MM cartridges, but that's about a $350 investment and I need to build a second TT before that. Unfortunately, I've developed an addiction to phono stages. I have about 6 or 7 designs I want to build! The Daniel's modified VSPS is first and I have the parts. I want to build a Pass Pearl or derivative, the PH-1, and a couple others like the LP797.


----------



## BoilermakerFan

It's not that you can't power multiple devices off one transformer; it's the issue that you +/-12-15V for the VSPS and 0-24 or 0-48 for the Aikido. If you wanted to limit yourself to 24V on the Aikido you have a much more limited tube selection, but you could order a 100-200VA toroid with dual 12Vac secondaries and pull the 24Vac for the Aikdo from a series connection and the 12Vac for the VSPS, but I would definitely use a filtered IEC socket and fuse each PSU separately, on both legs. You'll still have the chance for more noise, you might be splitting hairs too if your power is good and your ground is good.

 The 6GM8 cannot be run at 48V. 

 Other novals include the 12au7a (150V), 6922(48-170V), 6DJ8 (48-170V), 6h30(48-200V), 6n6p(100-200V), 6n1p(200-250V), 6cg7(200V), and 12BH7(48-250V). I would start with the 6DJ8/6922 and 12BH7 tubes at 48V first... There are a lot of nice options for sourcing new 6922 tubes too, so that makes them easier to find and you can get crazy and buy matched cryo'd sets for less than some of the 6GM8 or 6h30pi tubes...

 There are actually a lot of other noval options, but their gains are just to high, most between 50-100, which could be great for 1V CDPs, or MCs run through 40dB phono stages if the noise is kept in check, but probably not good for most other applications.


----------



## rodentmacbeastie

Quote:


  Originally Posted by *BoilermakerFan* /img/forum/go_quote.gif 
_It's not that you can't power multiple devices off one transformer; it's the issue that you +/-12-15V for the VSPS and 0-24 or 0-48 for the Aikido. If you wanted to limit yourself to 24V on the Aikido you have a much more limited tube selection, but you could order a 100-200VA toroid with dual 12Vac secondaries and pull the 24Vac for the Aikdo from a series connection and the 12Vac for the VSPS, but I would definitely use a filtered IEC socket and fuse each PSU separately, on both legs. ._

 



 I am interested in a 48V Aikido, but I think I am going to stick with the 24V and maybe try a 12SX7GT in there. I got my boards yesterday and the 6N27P tubes form that dude on Ebay. Now I have to order parts for the board.

 I have all my resistors picked and the cap are up in the air at the moment. Anyone have suggestions for what caps to use?


----------



## BoilermakerFan

Quote:


  Originally Posted by *rodentmacbeastie* /img/forum/go_quote.gif 
_I am interested in a 48V Aikido, but I think I am going to stick with the 24V and maybe try a 12SX7GT in there. I got my boards yesterday and the 6N27P tubes form that dude on Ebay. Now I have to order parts for the board.

 I have all my resistors picked and the cap are up in the air at the moment. Anyone have suggestions for what caps to use?_

 

Just use the LM317HV and a 22Vac dual secondaries transformer and you can easily step it up to 48V later. Just realize you will have to change out 6-10 resistors. I would go a step further and order higher voltage caps for the boards so I could build a 250V unit later an only need to swap resistors again. 

 Here's the HV 317:
LM317AHVT

 And John loves the RTI caps:
PS-1 Solid-State Regulator Kit

 He included the RTIs with Panasonic FMs in my kit. Manaox2 posted my BOM message a few pages back. I would only change the small mica cap to a Wima red box cap if I were ordering my own parts... I'll be adding big Coke can sized oil motor run caps for C4 when I build mine mainly for fun to try it... I forget the value of the caps at the moment.


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## digger945

rodent, are you building your 12SX7 as a linestage or hp amp?


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## rhester

What kin dof power supplies are you'll using to power the Akidio? Anybody used the sigma22 from amb?


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## digger945

This is what I am using atm, don't know exactly what it is:
Top of PS
Bottom of PS
xfmr
 It is set to exactly 24V. It will go higher, but doesn't sound as good.
 It uses a 338 reg, and is adjustable with a bournes pot.

 I started with a medical 24V 2A supply, it doesn't sound bad at all, I just don't use it anymore.
 I use one PS and tie the B+ and heaters together on the board(heaters in series), as the 24V aikido board is designed to be run this way(if you like, and only have one PS).


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## BoilermakerFan

The PSU is pretty open, Peeps have used S22, STEPs, TREAD, etc. The PSU just needs to be a good quality linear regulated supply. The Aikido architecture cuts the noise in half, but starting with a good, clean supply improves the sound of any device exponentially.

 John offers a low cost PSU kit. Peter Daniel has a great one for his AudioSector gainclone kits that many of us have used for other applications too. You'll have to email Peter through his AudioSector web site to get the costs for just the PSU or PSU kits...


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## digger945

The H-PS-1 is $24usd at the glassware yahoo store. This is a beautiful PS and you only need a trafo to go with it.

 Looks like the PS-1 kit has the regs for both high and low voltage(you need two trafos or one trafo with both high and low volt secondary). This is a nice PS as well. It is $74usd complete except transformer.

 Any last minute suggestions before I pull the trigger on a 5687+PS-1 kit? (I am re-reading you guys posts now)
 I guess I will wait for octal pcb's and shop in the mean time for 12SX7 tubes.
 Every day I read another article about the 12SX7 beating the snot out of the best of 6SN7's.


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## manaox2

Quote:


  Originally Posted by *rhester* /img/forum/go_quote.gif 
_What kin dof power supplies are you'll using to power the Akidio? Anybody used the sigma22 from amb?_

 

I have been strongly considering it because it is designed with the negative rail and for dual 25V inputs matching the transformer I have for a balanced 4 channel amplifier.


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## digger945

Hey, howz that project coming along?
 You gonna have some time off the end of next week?


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## manaox2

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_Hey, howz that project coming along?
 You gonna have some time off the end of next week?_

 

YHPM


----------



## rodentmacbeastie

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_rodent, are you building your 12SX7 as a linestage or hp amp?_

 


 I am building a 24V first, but I was thinking that since a 12SX7 was designed to run at 28v it would sound ok at 24v. If it sounded as good or better than the 6GM8 then why not try it at 48v. If I can use a LM317AHVT (x4) for the buffer and change a few resistors to accomodate a 12BH7 or a 12SX7 to make it sound better, why wouldn't I. Can't I use the LM317AHVT in the 24V build with the same heat sink an all and then when I go 48V I can change the resistors, adjust the voltage on the LM317AHVT, and it is 48V Aikido, right?


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## rodentmacbeastie

Quote:


  Originally Posted by *manaox2* /img/forum/go_quote.gif 
_I have been strongly considering it because it is designed with the negative rail and for dual 25V inputs matching the transformer I have for a balanced 4 channel amplifier._

 

I am building a balanced Aikido(2-24v boards) as well and was wondering about your intended use of the negative rail?


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## digger945

rodent,
 The data sheet for the 317HV shows that it has a voltage differential of some 60 volts. It is rated at 57 volts. I got to thinking about this and I really don't see why it wouldn't work just fine. Matter of fact, I am pretty sure the 317T would work also. If we put the 317 in the circuit with a 48V B+ then wouldn't just one 317 only "see" half of the voltage anyway?




 On the schematic, the two regs(2540 shown, it was the only one I could find) in series from B+ to ground will pretty much split the voltage in half(I read 13.2 volts @ 24V B+ on mine).
 When I though about this further, I think as long as your device(317/337/2540, etc.) can handle the voltage and current from biasing, and your heatsink can dissapate whatever heat, you should be just fine.

 FWIW, the DN2540N5 that I have in mine now is rated up to 400V, and is able to dissapate 15W(TO-220 package only). They are $1.60 each at Mouser.
 I will see if I can find the correct circuit with the 317's in it and redraw it with your 48V B+. I don't know about you guys, but it really helps me to look at the circuit on screen or printout.

 As for the 12SX7, if it needs 28V on the plate, I don't see why you couldn't build the circuit with 48V B+ and maybe crank it up later to see what the difference in SQ is. I bet it would work good with 24V on the plate.


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## rodentmacbeastie

I am looking at some crazy ideas for cooling anyway, so the extra heat will not be a problem. My Box-o-Goodies is going to be one vintage looking stereo cabinet abou 24" wide, 16" high and 12" deep. Inside that box I will have a HTPC with ESI Juli@ outputing I2S to a Buffalo DAC with NP D1 I/V stage. The DAC will receive DSD as well from a Denon spinner. The Aikido is next to a Firstwatt F1. I figure the F1 will handle a full ranger like a good HP amp handles cans, I got used to control and less distortion. This will be cooled by two liquid cooling systems. One will cool the air in the whole box(sealed to control humidity) by mounting a rad core inside as well. The second will directly cool the F1 and now maybe the Aikido buffers. I bought some Peltier thermoelectric plates to play with. When I build my house I am going to integrate these elements into my hot water heater and aircon systems. I am thinking that, since I have moving water on the land I will build a small generator from a car alternator(generator). The 12V DC is great for the lights, fans, Peltier plates, etc. I was thinking about running the DAC, Aikido, PC, and F1 off DC-DC power supplies. The only appliances that need AC are the TV and fridge. If I build a HT I would like to build a projector using LEDs as a light source and run it off DC as well. I guess I could wire four 12V batteries with relays to cut charge lines when the power is on. I could use one battery for the DAC and PC, three batteries in series for the 30V D1 rails, and all four wired in series for the 48V. I am sure the F1 would fit in there somewhere. If you have any other ideas or simple DC-DC 12V power supplies to get me the 30V+/- for the D1 and the 48V B+ for the Aikido. I am not so learned yet, this is all just ideas. 

 The benefits of a 12V DC house:
 - less electrical stress on us.
 - less noise in the power.
 - less heat generated by conversion between AC and DC.
 - free power and the infrastucture would cost half.
 - "the man" has to mind his own business.
 - less issues with Thai monsoons making things go boom.
 - less expensive power capacitors.

 I would use an invertor to get my 220V AC if it is necessary, but I am afraid that it will introduce lots of noise. I guess I could convert the power to 220V and use dual 55V transformer to convert the power from 220V to balanced 110V. This way I could use it easily in Canada and buy the big transformer in Thailand to act as a 220V/110V converter. This should also remove any noise introduced by the inverter.

 On a different note... Is there not a way to use two of these boards in a balanced push/pull set-up and remove all of the output caps?


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## digger945

I don't know if there is any way around the output coupling. Maybe coupled to another SS amp, mybe a JB design.If you use the 317, cooling will not be an issue at all. I don't know what the 12sx7 puts out for heat, but the 6gm8 is only warm to touch.I just read yet another article about the 12SX7 being run at 26.5V.I gotta try to stop listening to my aikido, I have lost all interest in everything else. If I do get around to building something else, I will need to put a diaper on before listening.Seriously. I've never been satisfied with an amp this long, of course I have not listened to every amp on the planet yet lol.


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## BoilermakerFan

Quote:


  Originally Posted by *rodentmacbeastie* /img/forum/go_quote.gif 
_I am looking at some crazy ideas for cooling anyway, so the extra heat will not be a problem. My Box-o-Goodies is going to be one vintage looking stereo cabinet abou 24" wide, 16" high and 12" deep. Inside that box I will have a HTPC with ESI Juli@ outputing I2S to a Buffalo DAC with NP D1 I/V stage. The DAC will receive DSD as well from a Denon spinner. The Aikido is next to a Firstwatt F1. I figure the F1 will handle a full ranger like a good HP amp handles cans, I got used to control and less distortion. This will be cooled by two liquid cooling systems. One will cool the air in the whole box(sealed to control humidity) by mounting a rad core inside as well. The second will directly cool the F1 and now maybe the Aikido buffers. I bought some Peltier thermoelectric plates to play with. When I build my house I am going to integrate these elements into my hot water heater and aircon systems. I am thinking that, since I have moving water on the land I will build a small generator from a car alternator(generator). The 12V DC is great for the lights, fans, Peltier plates, etc. I was thinking about running the DAC, Aikido, PC, and F1 off DC-DC power supplies. The only appliances that need AC are the TV and fridge. If I build a HT I would like to build a projector using LEDs as a light source and run it off DC as well. I guess I could wire four 12V batteries with relays to cut charge lines when the power is on. I could use one battery for the DAC and PC, three batteries in series for the 30V D1 rails, and all four wired in series for the 48V. I am sure the F1 would fit in there somewhere. If you have any other ideas or simple DC-DC 12V power supplies to get me the 30V+/- for the D1 and the 48V B+ for the Aikido. I am not so learned yet, this is all just ideas. 

 The benefits of a 12V DC house:
 - less electrical stress on us.
 - less noise in the power.
 - less heat generated by conversion between AC and DC.
 - free power and the infrastucture would cost half.
 - "the man" has to mind his own business.
 - less issues with Thai monsoons making things go boom.
 - less expensive power capacitors.

 I would use an invertor to get my 220V AC if it is necessary, but I am afraid that it will introduce lots of noise. I guess I could convert the power to 220V and use dual 55V transformer to convert the power from 220V to balanced 110V. This way I could use it easily in Canada and buy the big transformer in Thailand to act as a 220V/110V converter. This should also remove any noise introduced by the inverter.

 On a different note... Is there not a way to use two of these boards in a balanced push/pull set-up and remove all of the output caps?_

 

I don't want to discourage your plans, but there are some potentially large issues with the system. I can only imagine that Thailand has high humidity in the summer. Anytime you have a radiator or Peltier, you are going to have condensation. The fans and pumps used to circulate the water and cool the rads will make a lot of line noise so they would have to be on isolated power systems. 

 DC power systems lost out to AC due to current and voltage drops. A 12Vdc home will require huge cabling and the current draw for a device on 12Vdc will twice that of the same device at 24Vdc, and it's lower yet for AC. Battery based systems have their own disadvantages too, and you will see more variation in voltage on a 12Vdc system than a 220Vac system. For ease of math, let's say your secondaries are 22Vac to produce the 31Vdc in a regular PSU. If your house AC system browns out 15% and you drop to 187Vac, you'll have 18.7Vac on your secondaries and still have 26.4Vdc at the V-reg. Your amp will stay at 24Vdc, but your V-reg will run a little hot. Using a 12Vdc system and a see a 10% drop due to high demand loads, or more likely, low output from wind turbines, solar, or water, and your incoming voltage drops to 10.8Vdc and your secondaries drop to 21.6Vdc. Not so good... So you have to step up higher and regulate back down which involves power supply again and you need to step up high enough to minimize the percentage of voltage drop at the device. Most of the designers I really respect played around with various battery or DC only systems and all came back to AC power supplies with filtered AC feeding linear regulated power supplies.


 If your going completely off-grid than you either go without power at times or you need a generator. The generators on the market are designed to either output very high voltage DC or regulated AC. The DC out gensets are designed for use with RE systems and the RE system has the inverter built into it. The "regulated" AC gensets are that in the most generous of terms unless you spend big bucks... But I think the cost killer will still be the very large wire gauges needed to prevent voltage drops within the house. You would have to run 6 or 8 gauge where 14ga can be used for 120Vac and probably still be limited to 10A on a circuit versus 15 or 20 with AC. Actually, dedicated outlets could get you up to 60A at 220Vac if you panel is up to the task. Our Jenn Air oven and range is on a 40A 220Vac circuit by itself. It was in the house when we moved in, so I'm actually looking forward to replacing it with a much less power hungry stove, though we don't use the range top attachments that really suck up the power.

 I think co-generating your own power is awesome and I'm a member of the American Solar Energy Society here in the States. Our next house will be built to much higher energy efficiency standards and have solar hot water, solar PV panels, and hopefully wind turbines as well. BUT, my house will still be grid tied. I just plan to make more electricity than I use and sell the excess power to the grid. Once hydrogen systems become cost effective, I will divert the excess energy into generating and storing hydrogen.


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## manaox2

John has the RTI capacitors now available separately for purchase in the online store at $20 a pair. 
	

	
	
		
		

		
			





 I don't know anywhere else you can order these online.


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## rodentmacbeastie

If I use a +/- power supply is there not a way to avoid coupling caps? Could I not just wire one board - and the other +, reference them to a common ground with a resistor between them thus eliminating the need for coupling caps?


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## digger945

I'm not sure I follow you exactly, but if one stereo amp board was wired +/- 12V, you would have to really fine tune either the voltage or the bias to achieve a near perfect 0V (no DC offset) on the headphone out.


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## rodentmacbeastie

I have a couple of 24V Aikido boards to do a balanced preamp/canamp sitting here driving me mad! I need to order parts before I crack! I want to know if there is a way to remove the DC coupling caps. I thought that if a +/-12V ps was used there would be no need for coupling caps but I don't no if that is 100%. If that is the case, which caps could I remove and how difficult will it be to make everything balance? If I understand correctly, all I need use is a simple resistor for each channel. Where would I tie that resistor, from the + signal to ground and the - signal to ground? I am really new at this and this is my first and likely last big DIY project and I just want to get it right. I was under the belief that other that the extra current, the reason for going balanced was to cancel noise and drop out the caps leading to less coloration(an cash)?


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## looser101

No... if you are going balanced you have some options, and negative supplies are not required. You could remove both output caps and short the pads. The problem is how do you ensure that the voltages at the + and - output are exactly the same so that the net offset is 0mV or very close. You could trim the voltage so that you are close but drift would probably be a problem. You could build a servo to keep the dc between the two outputs zeroed. You could also use only one capacitor on the + or on the - output. Or you could build it like single ended and populate both output caps. Each option has its own problems and complications. Only you can decide which one you are comfortable with.


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## rodentmacbeastie

Caps it is.


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## digger945

Yea like looser101 said, you may finally get to the 0mV point, but you would have to check it often to make sure it doesn't drift.
 Just build it with cap coupling, you will LOVE IT I am sure. Cap coupling gets a bad rap if you ask me.
 Your right rodent, coupling caps do add or take from the coloration, but it's fun to try different ones to see how they react to the signal.
 Another point with just the SE amp would be, that it looks like +/- supply might work in the middle of the schematic(for the tubes), but you would have problems when you look at the input and output, they both rely on the ground to complete the coupling.

 Have you tried anything new looser101?
 I think I am going for the 5687 next.
 I already bought some tubes, and now looking at some Sylvania Gold Brand 5687's(cheap used ones). I want to do something different, even though I am perfectly content with the 6GM8 amp I have now.

 If I may ask another question looser101, I think that somehow I lack the last bit of something on the bottom end.
 My current output coupling is:
 Panasonic FA 4700uF 16V
 Auri 2.2uF 200V
 2x Auri .01uF 200V
 I have tried many caps, maybe it is my source, the 0404usb.
 I would try something else, if I knew someone else had tried it and it held some promise.


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## looser101

rodentmacbeastie: If you want to save some money on a balanced setup you can skip the output coupling cap on the - output, and you can use the standard size cap, since in this situation it doesn't have to be twice the value.

 digger945: Haven't been doing much with the HV Aikido lately, even though I ordered a PS-1 psu from JB. Should be here soon. You should really look at the 6H30, it's reported to be a very good low voltage tube. I could never get the sound I wanted with the 6CG7. RCA 6GU7 was a very good tube, much better than 6CG7 cleartops IMO. 6N6P as an input tube really woke up the highs. So I put in another set of 6H30's on the input with similar results. So currently it's a 6H30/6H30 Aikido.

 I have 3 projects on the go right now. Primaluna Prologue One (no mods yet, except for tubes). Blueberry Audio EL84 Triode SE speaker amp (just received some new Transcendar output transformers for it). And of course the Aikido is getting a new power supply soon.


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## digger945

OK well I will give the 6H30 another look then, maybe just order the parts for the 9pin mono boards I already have.
 I think I will go HV this time looser, manaox is gonna trade some parts for a quad of the 6GM8 tubes I recently purchased and two PS-1 boards are coming my way, they are the older ones with the misprint on them.
 The biggest reason I favored the 5687 setup is to try just output coupling directly from the tube, without the buffer, and the fact that the 5687 puts out some good power. Maybe later.

 At what voltage do you run the 6H30?


----------



## rodentmacbeastie

To be certain, which output caps can I remove and which can be smaller? If you can tell me the C# from the schematic it would be very helpful. Again, I am new to this and want to be sure. Also, if I wired one board for the L/R- and B+ of -24V and the second board L/R+ and B+ of +24V, with seperate PS each would there be any possibilities here?


----------



## rodentmacbeastie

Quote:


  Originally Posted by *rodentmacbeastie* /img/forum/go_quote.gif 
_To be certain, which output caps can I remove and which can be smaller? If you can tell me the C# from the schematic it would be very helpful. Again, I am new to this and want to be sure. In this scenario I remember reading somewhere John Broskie wrote that all that is needed in place of the caps is a resistor between the rails. This is why he said that the mono boards were easier to use in a balanced build and he was toying with the idea of releasing balanced kits. I am guessing that the reason was so it was easier to tied each (+)channel's ground to it's opposing (-)board's ground with a resistor. I remember the resistor is how it sort of autobiases itself. I could be thinking this up myself, but I am not that smart. I will try and find JB's paper on the balanced cuircuits. But if this is right, this makes think that with some crazy wiring that one board for the L/R- gets a B+ of -24V and the second board L/R+ and B+ of +24V referenced to each other with a resistor and with seperate PS each, it should work. Do you think there could be any possibilities here? Ugh, I have to find that paper on tubecad._

 

 I know I read it there.


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## rodentmacbeastie

Whoa, that is some crazy s$@t that just went on with my last post. It turned into two posts with a quote? I did not do any of that, creepy.


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## looser101

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_OK well I will give the 6H30 another look then, maybe just order the parts for the 9pin mono boards I already have.
 I think I will go HV this time looser, manaox is gonna trade some parts for a quad of the 6GM8 tubes I recently purchased and two PS-1 boards are coming my way, they are the older ones with the misprint on them.
 The biggest reason I favored the 5687 setup is to try just output coupling directly from the tube, without the buffer, and the fact that the 5687 puts out some good power. Maybe later.

 At what voltage do you run the 6H30?_

 

150 Volts biased at 40mA. Few tubes can take the abuse I put mine through and sound good doing it.

 Let me know when you are ready and I will give you some tips.


----------



## looser101

Quote:


  Originally Posted by *rodentmacbeastie* /img/forum/go_quote.gif 
_To be certain, which output caps can I remove and which can be smaller? If you can tell me the C# from the schematic it would be very helpful. Again, I am new to this and want to be sure. Also, if I wired one board for the L/R- and B+ of -24V and the second board L/R+ and B+ of +24V, with seperate PS each would there be any possibilities here?_

 

C4 is the output coupling cap. 470uF is good enough for low impedance headphones but some people prefer 1000uF. Not sure why Digger's amp lacks bass with a (too huge) 4700uF cap.

 First of all to use these boards balanced, a balanced source is required. Otherwise it's a headache I would pass on. My preference would be to use one board per channel. Say Right channel side for + (w/coupling cap) and Left channel for - (without cap, just a jumper). Do the same with the second board, which would then be the + / - for the other channel (Right channel?). This allows you to use two power supplies, one per channel, if you so desire. No negative supplies should be used. Some amps can use bipolar supplies to get rid of the output caps but I don't think this is a good candidate, as currently designed.


----------



## digger945

Another possibility is the low pass filter from the tube output to the buffer input.
 I tried the single 300 ohm resistor, per the schematic, and finally went back to the original 10K resistor followed by the 300pF cap to ground, forming the original low pass filter. Maybe I need to go back and reinsert the 300 ohm and try to find a different cap to make the new filter work correctly.
 EDIT: I don't see why it would not work with just the resistor, per JB's schematic, passing all of the signal.
 I'm warning up the soldering iron now.


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## rodentmacbeastie

Did Fierce put BG NX 1000uF 25V caps in C4 and C11? The manual calls for a 35V cap in C11 right? 

 And yes, I don't know why we would need a low pass filter unless your source is noisy. If the DAC is already low pass filtered, the only new HF noise should be from the Aikido's PS which is nullified in the circuit.


----------



## digger945

Yea, I own Fierces amp now, it came with BG NX 25V 1000uF in the C4 position, and that's all as BG NX does not get along too well with other stuff, even films. I can attest to this, I tried it, it sounds funky, but not real. Instrument get placed in wierd places, voice of artist behind you sometimes. Freeky when bypassed, not bad at all if used alone. 
 I guess if your gonna use a 48V PS then you will need at least 48 or 50V for C11, C12, C13, and, according to JB, C7,8,9 and 10 should be rated to the PS output in case a tube is yanked out with power on, or powered up witha tube missing from it's home.

 The low pass filter is a part of the 24V aikido circuit, but when I upgraded to the DN2540 output tranny's the new schematic just called for a 300 ohm resistor in the R20/21 position, no mention of the cap to ground. I am listening to the 300 ohm now, definitely don't like it as much as the 10k in the R20/21 pos. and the 300pF cap to ground, forming the low pass filter. This low pass filter, according to JB, is just to strip away some of the high freq noise from the tubes anyways. I like the slam of just the 300 alone, but with the filter, it's like a machine gun shooting syrup coated jellybeans into my ears, yea it's good for sure.


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## rodentmacbeastie

Balanced Aikido


 I see here that it looks all caps are present. The other article I mentioned he states that "carefully selected parts" would be needed.


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## digger945

A bit off topic...
 You have heard it said that "misery loves company".
 Well excitement loves company also, and I am excited.
 What do you need to order, maybe I can help out?
 EDIT: I clicked on the link you provided above, interesting, I had not read that yet.
 Thanks.


----------



## rodentmacbeastie

OK, forget about the truly balanced circuit. I will simply build two normal 24V boards. I am wondering if the tubecad linear PS has enough juice for two boards or should I get a second? I am buying most parts from sonicraft. They have a 20% sale for a couple more days and 50% off Jupiter beeswax caps. I thought that I would mirror Fierce's recommendation, but I am open to suggestion. I also have to buy parts for a couple of balanced D1 I/V stages for my Buffaloso all the help is appreciated.

 Here is Freak's BOM: http://www.lightmedark.com/aikido2.xls
 Here is the D1 BOM: diyAudio Forums

 -I am using all 1/2Watt PRP resistors
PRP 1/2 Watt Audio Resistors
 -3uF/200V Sonicap Gen I for C1
 -1uF/100V Mulitcap RTX for C12
 -0.1uF/100V Multicap RTX for C13
 -thinking about BG NX for C4 and C11 but this limits me to 24V, got FM 1000uF50V coming for now. Does C11 need to be higher than 50V if I use a 48V ps?
 -C7,C8,C9,C10 get Panasonic FM 1000uF/50V
 -C2 is a 220pF film cap
 -C5,C6 .047 Wima
 -for C3 it looks like Fierce used .47uF Muticap RTX and I could do that too.
 -I was thinking that if there is no trade off for usinf the high voltage LM317 then I will use it even for 24V which leaves the door open for future expandability. Thank you for all the help.




 I am using the same resistors for the D1 unless they are too big. The other parts I would love your help choosing. I am excited with parts arriving daily! I got my 10.2" touchscreen today as well as some SACDs and OCC wire for hook-up. Yesterday I got a Hakko soldering station and some 4% silver solder. The Aikido and D1 boards ready to populate.


----------



## digger945

Before I comment on the fierce aikido BOM, do you have the newer pcb's with the dual places for 317 reg or mosfets?..or the ones that have just the AOI silkscreen for regs only?
 Yes I have some extra stuff you should order anyways but just wanted to get ^that^ out of the way first to make sure you get the right parts.
 Also, is it safe to assume from here on out that your gonna need to order parts for 2 complete stereo boards?
 The last line of the product description at glass-ware says " Each board holds two Aikido linestage/headphone amplifiers; so, one board for stereo unbalanced or one board for one channel of balanced amplification.", so 2 boards = balanced amp.


 D1 I am unfamiliar with.


----------



## rodentmacbeastie

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_Before I comment on the fierce aikido BOM, do you have the newer pcb's with the dual places for 317 reg or mosfets?..or the ones that have just the AOI silkscreen for regs only?
 Yes I have some extra stuff you should order anyways but just wanted to get ^that^ out of the way first to make sure you get the right parts.
 Also, is it safe to assume from here on out that your gonna need to order parts for 2 complete stereo boards?
 The last line of the product description at glass-ware says " Each board holds two Aikido linestage/headphone amplifiers; so, one board for stereo unbalanced or one board for one channel of balanced amplification.", so 2 boards = balanced amp.


 D1 I am unfamiliar with._

 


 I have the new boards. I would live to hear suggestions for the parts, but soon as the sale is over at the end of November. I will need parts for two boards. I read the last line. This would describe a balanced amp if they were connected to nullify DC. So how are they balanced if they are simply two independant SE channels and not push-pull? There has to be a resistor or something to tie the two boards together. I know it can be done, just don't know how or if at all with this board? That said, I am all gung ho for two SE boards and I am sure it will sound great!


----------



## digger945

OK, one more ultra critical question, 
 Were you thinking of using this 24V aikido to do a 12SX7 amp in the future, or did you have plans for a totally new amp?..or did you just want to try the 6GM8 at 48V?

 I just thought of it, the 6GM8 and the 12SX7 are completely different tubes, one in 9pin and one 8, they need completely different pcb's to work.
 Just wondering Rod.


----------



## looser101

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_I am still studying post #271 to understand how you can hook this up balanced to make it work. As I read the article at Tubecad in the link you posted above, I am beginning to understand what your talking about now._

 

The one linked is a dedicated linestage not a headphone amp.

The Basics.


----------



## digger945

I was just trying to get it in my head how the current is going to return to each half of the one board.
 The source I understand, it's the aikido output I am confused about.


----------



## looser101

Pay close attention to the sinewave in the following drawing. It is equivalent to your music. When the + side of the driver is going positive, the - side is going negative (effectively twice the power, and not referenced to ground at the headphone). The balanced source takes care of the polarity of the signal for you.







 * Image Courtesy of Headroom


----------



## digger945

I got that down, no problem.
 I understand it with a direcly coupled solid state amp, but the output of the aikido, it's not the same. It's something I have never thought about before.

 EDIT: Yes, I think I understand what you mean in post 271, just short one of the channels output cap on one board (the negative in this case for balanced). Coupling caps on the positive. OK, no ground. I got it.


----------



## looser101

The output of the Aikido like all single ended amps has an output that is (for sake of illustration) say B+/2, so 12Volts in the case of the 24V Aikido. In this case the headphone driver would see 12v on one side and ground (0volts) on the other (which would be bad since a current would flow across the driver when no music was playing). So what can be done about this problem? We use a coupling capacitor. In this case it will block DC in the output stage and pass AC (ie. music). The DC voltage at the output of the coupling cap is effectively 0 and since ground is also 0 then no current will flow. Hope that is what you are asking.


----------



## rodentmacbeastie

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_OK, one more ultra critical question, 
 Were you thinking of using this 24V aikido to do a 12SX7 amp in the future, or did you have plans for a totally new amp?..or did you just want to try the 6GM8 at 48V?

 I just thought of it, the 6GM8 and the 12SX7 are completely different tubes, one in 9pin and one 8, they need completely different pcb's to work.
 Just wondering Rod._

 

The 6GM8 cannot run at 48V, JB has confirmed that with me. My intentions in if any, were to leave it open to 12SX7 in the future. JB himself said he was wondering what the 12SX7 would sound like at 48V?


----------



## digger945

OK, rodent, so this will be just a 24V 6GM8 amp then. So we don't really need to build it with all the 50V caps and such. So are we ordering the higher voltage parts for the future build of the 12SX7 amp? ...and if so I have no idea what values the Octal pcb needs to build that amp.
 But I do have some suggestions for the 24V 6GM8 amp.


----------



## digger945

Thank you Renato for the help to understand how this all works. I have learned a great deal today. I am bidding on some 6H30 tubes on ebay, if I lose, and I usually do, I will just order some from tubedepot or one of the other familiar ones.
 I have the owners manual for the mono noval pcb's in front of me. I think that I will just order the vishay resistors when I finish up the Dynamite order from Mouser tomorrow or Saturday. I will take your suggestions on parts and such and add them to my list.
 Later guys, I am tired and must get to bed now. 
 Thanks, it's been fun today.


----------



## rodentmacbeastie

Quote:


  Originally Posted by *looser101* /img/forum/go_quote.gif 
_The output of the Aikido like all single ended amps has an output that is (for sake of illustration) say B+/2, so 12Volts in the case of the 24V Aikido. In this case the headphone driver would see 12v on one side and ground (0volts) on the other (which would be bad since a current would flow across the driver when no music was playing). So what can be done about this problem? We use a coupling capacitor. In this case it will block DC in the output stage and pass AC (ie. music). The DC voltage at the output of the coupling cap is effectively 0 and since ground is also 0 then no current will flow. Hope that is what you are asking._

 



 I don't know, that is why I am asking! LOL! Right, so as I see it, unless this idea is fataly flawed, if we make one board B+ +24V and one B+ -24V and leave all caps for the tubes in place except remove the buffer lytics which are replaced by resistors tied to the other board... I am just guessing but I know I read it somewhere.


----------



## rodentmacbeastie

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_OK, rodent, so this will be just a 24V 6GM8 amp then. So we don't really need to build it with all the 50V caps and such. So are we ordering the higher voltage parts for the future build of the 12SX7 amp? ...and if so I have no idea what values the Octal pcb needs to build that amp.
 But I do have some suggestions for the 24V 6GM8 amp._

 

I was just thinking that I would use adaptors and change some resistors and voila! 12SX7 Aikido, ya know, something like that. The Pan FM 1000uF/50V will do fine for the heater string and the lytics for now. If I am happy with the FMs in there I may avoid Black Gates. Does anyone know how the Rubycon stack up to the Black Gates?


----------



## digger945

Do they make such an adapter to put an Octal tube into a Noval socket?
 This might be more hassle and could, if it exists, be way more expensive than just building two seperate amps.
 I gotta do some googling first.
 On C7,8,9,10= I have 100uF 25V in mine. I'm not sure that the 1000uF 50V you have listed will fit next to the tube sockets. JB's BOM says 10-1000uF and rated at B+. I think 100uF would be fine here, it is not directly in the signal path.
 On C5,6= I have the same Wima, but 0.1uF. 
 C3= Fierce kept the .47 Multicap. I now have an Auricap 2.2uF. JB calls for 1-3uF. I think I priced the Multicap .47, IIRC they ain't cheap.
 C4= I think the Panasonic FM should do fine here, get the BG to play with, I would buy both if it were me. This is the main coupling cap from buffer to headphone.
 C11= Same as C4, only this one is B+, this is the main power supply cap. I have a BG 1000uF 25V in mine now but I have used many different ones. I think I liked the Panasonic HA that I robbed from the Dynahi parts stash best. Needs to be a minimum 1000uF and rated at B+ and no more than about 28mm diameter.
 If you really want to build this for a 48V PS and 50V stuff aint available, then 63V will work fine, maybe 80 or 100V if they don't get too big to fit on the board.
 C1 is only necessary if you plan to use the line out, it does not affect the headphone out, it is just the coupling cap to the next amp in your system.


----------



## digger945

On the resistor side...
 Does your amp have an R13? Mine does not and the revised schematic does not but it is listed in the revised BOM on tubecad.

 R1,5,6,7,12,14= 1M. This is what I have.
 R2,4= 180R is what I have. JB says 100-240 ohm, and recommends 180.
 R3,9,10= I have 330R, JB recommends 300. Try to get 300 if you can.
 R8,11= I have 180R, JB recommends 180.
 R15= I used to have 18R when I ran the 317's, JB recommends 20. I would order 18, 20, and 24 or 25 to play with.
 R16= I had 5R when I got it. JB recommends 2R. I would order 2 & 5 to play with.
 R18= 100k.
 R19= 75k.
 R20/21= Your pcb should be revised to show just one part number. By the schematic this should be 10k, and that's what I had also.
 I have read a lot of John's articles that have 20 ohm or 24 ohm for both R15 & 16.
 If I were ordering I would get some extra 10,20,10k,and 4 100k's to play with later, should you decide to upgrade the output to mosfet.
 I still think you would be more satisfied with two amps, one for the 6GM8 and one for the 12SX7.


----------



## rodentmacbeastie

If I use the FM 1000uF 50V for the coupling caps that I have and the HV LM reg I could be covered in both scenarios. The only difference will be a couple of resistors and the octal adapters which can be made from an octal socket soldered to the base of a broken noval tube and then glued in place. One could even to a vibration mount such as the $45 sockets available to reduce microphonics. I could use a chassis mount socket with leads to the board. Many options for octal conversion. I think what has to be done first is someone needs to buy 4 12SX7GT(native 26.5V-28V) tubes and try them at 24V and see how they sound. If they are better than the 6GM8 at 24V then any voltage up to 48V will likely be better. The stock regs can be used with a B+ of double their rating since they only see half the voltage. If you surpass that voltage then using the HV would be required. The heatsink will have to be bigger though. 

 We need to see what a quad of 12SX7GT in the set-up at 25.2V is like. I guess I will have to build one board with octals and one with novals. They will the same caps and I will use the FM's 50V for coupling and I can always go 25V BG NX after the comparison. I will try a 48V PS as well. So I need a 48V PS and some way to convert the signal from balanced to SE. I can probably get a couple of Sowter 1:1 transformers to do the SE conversion and I will need suggestion for a simple linear PS for 48V.
 If we were to run it at 48V, are there any better options for mosfet output devices?


----------



## digger945

I don't think you gotta worry about the heatsinks if you run the 317's. They run cool even at 28V and biased with 2 ohms(I tried it, they don't even get warm).
 Mosfets? There are probably few that wouldn't work, pins installed correctly.


----------



## rodentmacbeastie

OK, so all I need to do to run 12SX7GT is adjust the resistor values from 180 to 220, the 75K to 82K and make sure all of the caps are 50V or higher. The PS is the next thing. The one that John offers is max 25.2V, but what is limiting it? If the device cannot handle the 48V, could I just change it to a HV LM317 and use the same board? I am also looking for a shunt reg PS for my D1 I/V with +/-30V rails if you have any ideas. Twisted Pear is coming out with a shunt reg but it won't do 30V.


----------



## digger945

+/- 30V? I dunno. Do you need a lot of current? I could sell you an extra Dynahi PS pcb, but you may have better success just ordering an amb alpha kit from Glass Jar.
 I am not familiar with the D1.


----------



## rodentmacbeastie

It uses Nelson Pass's balanced supersymmetric design with each balanced channel(+/-) having 4 IRF610 mosfets working in pairs.

diyAudio Forums - Pass D1 I/V Stage PCB - Page 1


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## rodentmacbeastie

What about other output devices than the LM317? Could you use some JFETs like the 2SK170? It is good to about 30v I think so it would be fine with the 24V/2 and even 48/2 for 24V at the JFET. I don't know what else would have to be done?


----------



## Coreyk78

I have a question about tube choices, I have noticed a lot of auctions on ebay with 6N1P tubes that are supposed to be "close" to the same specs as a 6dj8. Does anyone know what the difference would be and if it would be possible to use those tubes with the component values recommended by JB for using 6DJ8/6922 tubes? Would be nice if it was an option because they are cheap and plentiful on ebay.


----------



## digger945

The 9pin users guide shows the values for the 6N1P at 3 different voltages.

 The 24V aikido users guide shows the specs for running the 6DJ8/6922 at 24V B+, but they can be run at high voltages also(scroll down to page 10).

 I think the two are somewhat similar, and can each be run at high voltages.


----------



## rodentmacbeastie

I am going with Multicap and instead of .47uF/400v like Fierce, I was thinking 1uF/100V. How much difference is it going to make between the 100v/200v/400v versions? I was thinking that the 100V will do fine and anything higher is unneccesary. I don't know why Freak put a 400V cap where he could have used a 100V?


----------



## digger945

By ordering the 400V cap you have the option of robbing it for use on a HV amp at a later date
	

	
	
		
		

		
			





 I do this all the time, rob from one project to mod another.
 On your previous post about the output transistors/regulators, I think you will be pleasantly surprised with the 317's, even more so in balanced configuration. You would never think that such a good sound can come from a voltage regulator. The only reason I put the DN2540's in mine was because I read the article on TCJ about it and just wanted to try some modding on my own, that and the fact they were cheap and I was placing an order anyways.

 So how are you coming along with your BOM?
 I finally took advantage of the ebay/microsoft 30% discount to order a quad of 6H30's to go ahead with the noval HV build.


----------



## Coreyk78

I ordered my 24V Aikido board yesterday since it was on sale, and also ordered the H-PS1 kit and some tube sockets. 

 I decided to get some Russian 6N23P tubes, I got a lot of 8 made in 1992 off of Ebay and used the microsoft cashback on them to end up pretty cheap. 

 JB provides recommended values for the resistors depending on which tube is used, but gives a range of caps without a specific recommendation. I'm at a loss on how to figure out what cap sizes would be optimal for me. I will be using the headphone section for my JVC RX700 which have a 48ohm impedance if that helps to choose sizes. The line out will be feeding my gainclone and powered sub.


----------



## digger945

6N23 at 24V, or did you mean 6N27?


----------



## Coreyk78

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_6N23 at 24V, or did you mean 6N27?_

 

6n23 at 24v, I assume since they are a direct replacement for 6dj8 and JB shows how to use them at 24v that they would work right?


----------



## digger945

The 6DJ8 and 6922 are in the updated 24V users guide, with the parts values shown for running at 24V B+, and I have read many places that the 6DJ8/6922 are direct derivatives of the Russian 6N23.
 Interesting. Thing is if you don't like the 6N23 you can always sub another tube, if you like, without much fuss (R2,4,8,and 11 in most cases).
 EDIT:All info I find shows the 6DJ8 and 6N23 to be the same in all specs with the exception of max voltage rating.


----------



## rodentmacbeastie

The PRP resistors that Fierce used don't come in some values he listed in his BOM. So I switched the 2R to a 5R, the 20R to a 22R, the 300R to a 330R. Will there be any major change with these, or should I seek out the exact values?


----------



## digger945

Yea I meant to say that I got his BOM and looked at it, and he had all of the values correct, but some of them were beside the wrong part places. R15 through 19 were mixed up a bit, but that is in relation to my/his amp, and I am unsure if these resistor numbers are changed on the newer uptaded boards.


----------



## rodentmacbeastie

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_Yea I meant to say that I got his BOM and looked at it, and he had all of the values correct, but some of them were beside the wrong part places. R15 through 19 were mixed up a bit, but that is in relation to my/his amp, and I am unsure if these resistor numbers are changed on the newer uptaded boards._

 


 I think the resistor values are the same, the new board just adds a seperate high voltage B+ pad. Could you check to see if the resistor value he used amp is the same as the BOM for (300R for R3,9,10), (20R for R17), and (2R for R18)? The BOM calls for these resistor values, but PRP does not make them so he either used different values or different resistors. I am curious which? I am going to stick with the 24V and try to avoid tinkering and rolling of parts in an effort save cash. 

 My wife can't get a visa to come to Canada to see me so I will need to go to Thailand to see her in the middle of a revolution. My work contract here in Canada has been extended to June. I intended on getting back to her in November. I have not seen her in 14 months and not much more than a couple of months in the last three years. I have been on a mission to save money so I can buy land and build a house before this crisis that will come in the new year. Now, because the other contactors are so slow I will not be ready when it starts and will have to play catch-up in Thailand. I expected this global crisis and was ready for it under Bush Sr. back in the 90's. When he did not get it done I thought the threat had subsided. Enter Junior! I have spent the last six years finding an alternate home on the globe to prepare for what Junior has done for his dad. During this time I fell I fell in love and everything in the scope changed. I had wanted to be set-up before the ID cards with radio chips were issued to the US and the NAU goes through in 2010 because of the trouble these events will create. I sold my system to get back to Canada a few years ago to earn cash as SCUBA instructors may have the best job in the world, their pay is low. The only possesions I have is my music and a few changes of clothes. I am squatting at a friends house who has a PC which helps. Thankfully, I have my DIY project to keep me sane! I just can't let the costs get out of control and exceed my budget even though the extended contract means more cash. We are all going to need to be tight in the near future and keep communication lines open in search of the truth.


----------



## digger945

I'm gonna get you a list of the resistor values I have, but first I just wanted to say that I had no idea... ummm I don't know what to say really.
 Can you move her here to where you are? How hard is it in Canada? If and when the ID thing goes through, and some think it will be stalled, it could make things harder, but it may just make things easier.
 I don't know much of nothin', but I know what it is like to be away from the one you love most.


----------



## digger945

OK, maybe I will just skip freak's BOM and just give you the part's values straight from the board.
 Resistor list for one channel only, 24V amp, all PRP's on mine:
 R1,5,6,7,12,14=1M
 R2,4=180
 R3,9,10=330
 R15=5
 R16=18
 R17=10k
 R18=100k
 R19=75k
 R20,21=10k(Note R20/21 are the same part on both left and right channels, the resistor that couples the tube output to the buffer input, and forms the low pass filter at the same time, new pcb's may be corrected for this, but the updated pdf user's guide on TCJ still shows the old pcb, with R20/21.)
 R15/16 don't have to be 5/18 respectively. They could be 20/20 or 24/24 or 25/25.
 3,9,10 are recommended 300 by JB.

 PM sent Rodent.


----------



## looser101

Quote:


  Originally Posted by *rodentmacbeastie* /img/forum/go_quote.gif 
_The PRP resistors that Fierce used don't come in some values he listed in his BOM. So I switched the 2R to a 5R, the 20R to a 22R, the 300R to a 330R. Will there be any major change with these, or should I seek out the exact values?_

 

None of those values are very critical and the values you chose will work well.


----------



## rodentmacbeastie

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_I'm gonna get you a list of the resistor values I have, but first I just wanted to say that I had no idea... ummm I don't know what to say really.
 Can you move her here to where you are? How hard is it in Canada? If and when the ID thing goes through, and some think it will be stalled, it could make things harder, but it may just make things easier.
 I don't know much of nothin', but I know what it is like to be away from the one you love most._

 



 I can't even get her here to meet my family for three weeks! As for the cards... The US will have anothr "terror" attack and the people will line up. I have a friend in intelligence says that a mushroom in the sky in inevitable to make people run for the cards. If we come out of this with less than a billion dead, it will be because of the will of good men!


----------



## rodentmacbeastie

I am sorry to spoil the Christmas cheer.


----------



## manaox2

Quote:


  Originally Posted by *rodentmacbeastie* /img/forum/go_quote.gif 
_I am sorry to spoil the Christmas cheer.
	

	
	
		
		

		
		
	


	


_

 

Those passports with the RF chip in them can be legally smashed with a hammer if you feel like it or kept in an aluminum foil wallet. 
	

	
	
		
		

		
		
	


	




 Take care of yourself, hope you still have a great christmas.


----------



## rodentmacbeastie

Yah, but smashing in Canada is a very big no no. I do keep it in a copper foil sleeve I made. This is also why my DIY Box'O'Goodies HTPC is going to be copper shielded on every surface... Shielding in both directions is good for my mental health.


----------



## Coreyk78

I received my Aikido board and H-PS-1 kit today and I am very impressed by the quality of these boards.

 I have a question regarding the power supply, the parts I was sent in the kit are sized for 12VAC input or 24vac input to get a regulated 25.2 vdc output. Would it be ok to use a dual 24vac secondaries transformer and only use 1 of the secondaries for now so that I could reuse the transformer later if I decide to step up to 48v? Or would it be better to get a dual 12vac transformer and wire the secondaries in series for 24vac? I'm looking at Antek toroids specifically. It looks like the 12v transformer in series would have more current headroom given the same VA rating.

 edit- and then I forgot Antek doesn't offer many sizes in 24v, which pretty much limits it to the dual 12v in series. The PS-1 schematic recommends only 24vac @ 1A so I don't know if I would be safe using a 25v transformer.


----------



## digger945

When you ordered your H-PS-1 did you have a pull down menu on the glassware-yahoo website to select between 5V, 6.3V, 12.6V, 25.2V?
 Did you pick 25.2V?


----------



## Coreyk78

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_When you ordered your H-PS-1 did you have a pull down menu on the glassware-yahoo website to select between 5V, 6.3V, 12.6V, 25.2V?
 Did you pick 25.2V?_

 

Yeah, I ordered the 25.2v kit.

 I scanned the schematic that came with it.


----------



## digger945

It would apprear you can go witha 24V xfmr and have a full wave rectifier, or use a 12V xfmr and have a fullwave voltage doubler. The method you use will determine the orientation of C5 and C6.
 I guess it just depends on what transformer you are gonna use, or buy.
 Thanks for the schematic btw.

 Pertaining to your post #317, I don't think you would have to wire dual 12V secondaries in series if you were using the 12V voltage doubler, but you could do that to obtain 24V(for the 24V full wave bridge rectifier) provided you are using the correct primaries.
 Do you already have a xfmr like that now?
 I need to order some xfmr's myself.


----------



## Coreyk78

I haven't ordered a xformer yet, but I'm planning to order it soon, since I need two 25v 300VA xformers for my dual mono gainclone project.


----------



## digger945

I just wanted to say that 6GM8's heaters' draw .33A each(I am sure you are prolly already aware of this
	

	
	
		
		

		
			





).

 Do you have a certain place where you order your transformers. I am in the market for some 6.3V. Maybe one 4A or two 2A.


----------



## Coreyk78

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_I just wanted to say that 6GM8's heaters' draw .33A each(I am sure you are prolly already aware of this
	

	
	
		
		

		
		
	


	




).

 Do you have a certain place where you order your transformers. I am in the market for some 6.3V. Maybe one 4A or two 2A._

 

I'm actually going to be using 6N23P tubes (Russian 6DJ8 clones) using the resistor values given by JB for using those tubes at 24V.

 I haven't used them before, but I have read good things about Antek xformers and thats where I'm going to be ordering from.

AnTek Inc.


----------



## digger945

Ahh, the 6N23. You will be the first I know of. The data for the 6N23 shows .365A heater current.
 I look forward to knowing what you think of how they sound in the Aikido circuit.

 I like the looks of the AnTek torroids, are they reasonably priced?


----------



## Coreyk78

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_Ahh, the 6N23. You will be the first I know of. The data for the 6N23 shows .365A heater current.
 I look forward to knowing what you think of how they sound in the Aikido circuit.

 I like the looks of the AnTek torroids, are they reasonably priced?_

 

Yeah the Antek are pretty inexpensive, they have a price list on the site, you just order directly from them.


----------



## BoilermakerFan

You can use the AnTek 22V secondary torroids.


----------



## digger945

^I use a 22V on mine now.


----------



## nano_machine

Has anyone tried building this with this with 6DJ8/6922's at 24V? 6GM8's are getting so difficult to find.


----------



## rodentmacbeastie

I am still awating my replacement H-PS-1 board from Tubecad. I am wondering if one of these PS kits is enough to power two boards? I should get another H-PS-1 board right? Any suggestions for a transformer?


----------



## rodentmacbeastie

Would you be able to feed an IRF610 with a LM317 in the buffer? I have some IRF610 from my D1 I/V stage left over znd wondered if they would sound better?


----------



## BoilermakerFan

Quote:


  Originally Posted by *nano_machine* /img/forum/go_quote.gif 
_Has anyone tried building this with this with 6DJ8/6922's at 24V? 6GM8's are getting so difficult to find._

 

The tube buffered gainclone runs a 6922 at 35V and the chip at 24V so I suspect the sound quality suffered at 24V. Joe didn't specifically say he tested it at 24V, but I'm sure he did as he likes to keep the design as simple as possible. They will sound better at 48V though.

  Quote:


  Originally Posted by *rodentmacbeastie* /img/forum/go_quote.gif 
_I am still awating my replacement H-PS-1 board from Tubecad. I am wondering if one of these PS kits is enough to power two boards? I should get another H-PS-1 board right? Any suggestions for a transformer?_

 

One H-PS-1 is enough to run the Aikido 24V board, so it should have the power to run two separate Octal boards and a buffer.


  Quote:


  Originally Posted by *rodentmacbeastie* /img/forum/go_quote.gif 
_Would you be able to feed an IRF610 with a LM317 in the buffer? I have some IRF610 from my D1 I/V stage left over znd wondered if they would sound better?_

 

I have the IRF510s and IRF610s to try in my 24V board and plan to run them at 24V with LM317, LT1085, and the 10M45S current sources. However, the bias current resistor changes for the LV regs versus the FET reg. 

 I will also be testing the IRFZ35 FET from the Millett Hybrid MAX in the Aikido and the IRF510/IRF610 complimentary pairs will be auditioned in the MOSFET-MAX when I build it on the new rev1.2 board.


----------



## digger945

BMF, do you have the newer pcb's with the dual thru holes for both regs and fets?


----------



## BoilermakerFan

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_BMF, do you have the newer pcb's with the dual thru holes for both regs and fets?_

 

Why yes, yes I do...


----------



## digger945

^You crack me up, goofball LOL
	

	
	
		
		

		
			




 Thanks I needed a laugh, really.

 I guess I will order some of those IRF mosfets and give them a try, see how they sound. While I was ordering H-PS-1 stuffs,I also ordered some extra LM350's and LT1085's to try.

 Anybody got any links to cheap/on sale xfmr's? <for the 6H30 - 150V@120+mA and 6.3V@4A minimum.
 I will prolly go with Digikey/Mouser Hammond stuff, can't argue with the price, though they are almost all labeled with the "BIG" stamp, so extra shipping.


----------



## BoilermakerFan

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_^You crack me up, goofball LOL
	

	
	
		
		

		
		
	


	



 Thanks I needed a laugh, really.

 I guess I will order some of those IRF mosfets and give them a try, see how they sound. While I was ordering H-PS-1 stuffs,I also ordered some extra LM350's and LT1085's to try.

 Anybody got any links to cheap/on sale xfmr's? <for the 6H30 - 150V@120+mA and 6.3V@4A minimum.
 I will prolly go with Digikey/Mouser Hammond stuff, can't argue with the price, though they are almost all labeled with the "BIG" stamp, so extra shipping._

 

I typed it in an Austin Powers voice too. 
	

	
	
		
		

		
		
	


	




 You can use transistor sockets and 3/8" standoffs as spacers for threaded heatsinks to make swapping easier. That's what I'll be doing on all three MAXes and the Aikido. It adds some costs to say the least, but it will save a ton of time and limit the risk of lifting a trace so I think it is worth it. Initially I'll use the same heatsinks as my MAX builds on the Aikido, for the FETs, then I'll set them up on the bigger Aikido 'sinks once I find the set I like the best. 

 Antek has 150V toroids with 6.3V and 12.6V taps. Price is definitely better at Antek than Digi or Mouser. I plan to order a 150V and 200-250V toroid for the Aikido when I order all my other transformers to minimize shipping since Antek is $10 flat rate.


----------



## digger945

I can't seem to find a bloody good tranny socket for me TO-220 stuffs
	

	
	
		
		

		
		
	


	




LOL.
 I'll take your suggestions(on the socket), price is of no concern. The heatsinks I have already got 3 verticle holes for 3 different device mounting heights. I have seen these on an Aavid datasheet from a link on Mouser earlier today but can't remember what exactly I was looking at or looking for. It will be a booger to get all the solder out of the holes to mount sockets as these pcb's are so thick. I finally gave up when I mounted the 2540's and just mounted the device in the top hole on the HS and cut the legs off so they were just a little shy of the pcb (when the HS was re-mounted), then touched the legs with a little solder first and it soon wicked up from the pcb.

 Hey thanks for pointing me back to AnTek, I had looked at that traffo before and didn't notice that it has plenty of 6.3V current for my build, and the most attractive part, only like 29 bucks, how could you go wrong. Perfect
	

	
	
		
		

		
		
	


	




 thanks again(Austin?), this will save me a ton of dough(for sockets maybe?).


----------



## MisterX

http://media.digikey.com/photos/Molex/10-18-2031.jpg

 Part # WM2551-ND


----------



## digger945

Cool, thanks yet again Mr. X.

 EDIT: Price for one piece at Mouser is less than 100 pcs at Digikey. Still not a bad price either way.


----------



## BoilermakerFan

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_Cool, thanks yet again Mr. X.

 EDIT: Price for one piece at Mouser is less than 100 pcs at Digikey. Still not a bad price either way._

 

I'll be using the ones Mr. X linked. I paid $1.88 for mine, but I had a lot of other bits on the order, so Digi was cheaper for me overall. I'm not sure if the multi-holed heatsinks will work with the sockets unless they are spaced 3/8" up. I haven't done a trial fit on my PCBs though. I know the heatsinks for the 24V Aikido only come with pins, so I have to pull those and tap to 6-32. The MAX 2-1/2" heatsinks are screw mount though.


----------



## Coreyk78

Well since I have too much time on my hands, and I haven't bought most of the components to populate my 24v Aikido board I've been thinking about changing my plans for the build. I have 8 6N23P tubes, basically the Russian 6DJ8 which are designed for ~100V operation. I'm hoping to build this thing once, so I want to try and get the best result the first time. 

 I already have the H-PS-1 regulator board and an inexpensive 24vct xformer because I was planning to go with 25.2V B+, but I'm wondering if I can change some components to use that for the heater supply. (regulated power for the heaters may be overkill, but I'd like to use the board since I already have it.)

 The big thing that I don't yet understand is the best way to get the 100v for the B+. I could build an unregulated power supply using a 36V + 36V xformer series wired to give 72VAC and 100VDC after rectification using a spare Audiosector gainclone rectifier board I already have with MUR860 diodes and some appropriate voltage rated smoothing caps. The thing is most xformers at that voltage are much higher VA rating than I need, and thus more expensive than I need, and I would still need a 2nd low voltage xformer for the heater supply.

 The other option I can see is using a xformer designed for traditional tube amps, Antek has a 150v + 150v/ 6.3v + 6.3v xformer, but high voltage stuff is beyond my knowledge right now and I wouldn't know how to reduce that voltage to get it down to 100. And I haven't read the Aikido manual enough to really comprehend how to wire seperate B+ and heater voltages and use the right regulators for the Headamp section and make it all work with the high voltage. I've tried a couple times over the last weekend to figure it out, but its a bit over my head I'm afraid. I think it would be the best performance to run the tubes at 100V but I just don't know how to do it. Maybe I just need to keep rereading the manual until it sinks in instead of thinking out loud on this thread, haha.

 Of course there is the other option of just waiting to find some reasonably priced 6GM8 tubes, or just forging ahead with my original plan of low-voltage 6DJ8s and just see how it sounds for myself.

 Ugh, too many options has my polish brain spinning, I think I'm more confused on what to do than ever.


----------



## digger945

Corey,
 Vacuumtubes.net shows 6GM8's for $20 each.
 Nixie Store on ebay shows two pairs of 6N27P's left, buy-it-now price of $48/pair with $8 shipping, not bad me thinks.

 On the power supply and/or regulator, I am gonna use the $74 PS-1 as soon as they are back in stock. It is good from 100V - 300V. I'm getting a transformer(both B+ and 6.3V heater secondaries) from AnTek for $29 + shipping.

 BMF, I added the TO220 sockets to my Mouser order, I bought 10 so the price was $1.09 each
	

	
	
		
		

		
		
	


	




.


----------



## Coreyk78

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_On the power supply and/or regulator, I am gonna use the $74 PS-1 as soon as they are back in stock. It is good from 100V - 300V. I'm getting a transformer(both B+ and 6.3V heater secondaries) from AnTek for $29 + shipping._

 

Yeah I like the idea of the PS-1, but I'm not really wanting to spend that much more money on the power supply if I don't have too. 

 When I think about it more I should still be able to use the H-PS-1 @25.2v for the heater supply since they are wired in series, and use another power supply for the 100V B+. I don't know how to design and build my own regulated power supply, since I don't really get how to set up a voltage regulator circuit. However, getting an unregulated 100v wouldn't be too difficult I think if I do it like I suggested in my previous post. That way at least I'm not wasting the 40 bucks I already spent on these 6N23P tubes. I still need to study up more on which regulators to use for the headphone section, looks like IXCY 10M45S should be used with the higher voltage.


----------



## BoilermakerFan

Good deal there Digger. I ordered about 30, so that would have saved me, oh, $20 or so... Oh well, I still didn't need anything else from Mouser at the time.

 Corey

 IMHO, the PSU is the most critical piece of any component. Sure the Aikido cuts the NOISE in half, but an unregulated supply will also have voltage issues and more. Save money on tubes if you have to, but don't skimp on the PSU. remember, the "stuff" flows downhill and the PSU is at the top of hill, your headphones are at the bottom of the hill. Garbage In, Garbage Out. Use a filtered IEC jack and a regulated PSU for the best possible power. Maybe even consider the $7 bucks in hardware for a ground loop breaker at the star ground point too. Again, MHO, but there are plenty of other areas to cut costs with much lower impact to the sound quality than a poor PSU.


----------



## Coreyk78

Yeah, I suppose you're right BMF, I'll probably be waiting for the PS-1 to come back in stock so I can do high voltage properly. 
 Still cheaper than dropping $20+/tube for 6GM8s, especially since I'm the kind of guy that likes to have at least 1 spare set for something harder to find like that.


----------



## Coreyk78

I felt like posting an update on my build progress, I have most of my parts gathered for my 6N23P high-voltage 24V Aikido (oxymoron? hehe) 

 I have my order in for a PS-1 kit and am just waiting for the next set of PCBs to be in stock. 

 So far I have 3.3uf Solen PPBs that I'm going to bypass with some russian pios and .47uf multicaps for C1 and C3, and some 1uf Solens for C12 and C13. I also got some 2200uf 35V Nichicon HEs for the heater caps, a 33uf 200V Nichicon PW for C11 and some rather huge sized 470uf 200V PWs for C4, they are almost bigger than some 10000uf 50V Panasonics I have. I also have a bunch of nos ERO-Roderstein KP caps in various sizes on their way to me. Resistors are a mix of Holco, Allen Bradley, Ohmite and Vishay, using the high quality ones in the critical positions.
 I have an Antek 150-0-150/6.3-0-6.3 toroid in the mail, so I'm close to having all the parts collected.

 I forgot to get the heatsinks and FETs on my last mouser order, (doh!) but I need a couple other odds and ends for a different project so I'll get those soon.

 I'm still unsure of what voltage I'm going to use for B+, 100V is suggested for 6DJ8s in the manual, but I've been able to email JB and discuss that a little bit, and he said his favorite amp for his HD650s uses a 150V B+ with 6DJ8s.

 Being a total high voltage tube noob I look at the 6N23P datasheet and it says 100V anode voltage, but 300V max anode voltage, pretty much the same as 6DJ8. Am I going to shorten the tube life by running somewhere around 150V B+? 
 Also I haven't seen the manual for the PS-1 yet, but I think it should be able to drop the 300VCT from the transformer to 150VDC without any problems right?

 I just want this thing to be done right, I'm spending more money than I had planned to, but I intend to use this for years to come. Now I just need to pick out an enclosure that will do all these parts justice, maybe a Par-Metal 20 series, I don't know yet.


----------



## digger945

Quote:


  Originally Posted by *Coreyk78* /img/forum/go_quote.gif 
_I felt like posting an update on my build progress, I have most of my parts gathered for my 6N23P high-voltage 24V Aikido (oxymoron? hehe)_

 

Hey that's what the thread is for and I've been wondering how you were coming along.
	

	
	
		
		

		
			




  Quote:


 I have my order in for a PS-1 kit and am just waiting for the next set of PCBs to be in stock. 
 

Yea I noticed that it looks like maybe 2 more weeks for the PS-1's to be ready to ship.

  Quote:


 So far I have 3.3uf Solen PPBs that I'm going to bypass with some russian pios and .47uf multicaps for C1 and C3, and some 1uf Solens for C12 and C13. I also got some 2200uf 35V Nichicon HEs for the heater caps, a 33uf 200V Nichicon PW for C11 and some rather huge sized 470uf 200V PWs for C4, they are almost bigger than some 10000uf 50V Panasonics I have. I also have a bunch of nos ERO-Roderstein KP caps in various sizes on their way to me. Resistors are a mix of Holco, Allen Bradley, Ohmite and Vishay, using the high quality ones in the critical positions.
 I have an Antek 150-0-150/6.3-0-6.3 toroid in the mail, so I'm close to having all the parts collected. 
 

What's the lead spacing on those 2200uF/35V Nich. heater caps, I show about 3.5mm or so on my pcb? Hey I ordered some nice looking Cornell Dubilier 470uF 450V caps from a military surplus guy on ebay and can't wait to try them out as headphone coupling caps. I also got a fair deal on some Holco resistors. It will be interesting to listen to them as well.
 If I may, how did you order the Antek, do you just use PayPal and put the traffo number in the info box when paying? I sent an email about a week ago and have yet to recieve a reply. Maybe I should use the phone
	

	
	
		
		

		
		
	


	




. 

  Quote:


 I forgot to get the heatsinks and FETs on my last mouser order, (doh!) but I need a couple other odds and ends for a different project so I'll get those soon. 
 

I'm glad I'm not the only one to do this.
  Quote:


 I'm still unsure of what voltage I'm going to use for B+, 100V is suggested for 6DJ8s in the manual, but I've been able to email JB and discuss that a little bit, and he said his favorite amp for his HD650s uses a 150V B+ with 6DJ8s.

 Being a total high voltage tube noob I look at the 6N23P datasheet and it says 100V anode voltage, but 300V max anode voltage, pretty much the same as 6DJ8. Am I going to shorten the tube life by running somewhere around 150V B+? 
 Also I haven't seen the manual for the PS-1 yet, but I think it should be able to drop the 300VCT from the transformer to 150VDC without any problems right? 
 

Just be aware that whatever your B+, each triode will only be getting half(or less that half) of that B+ Voltage, so if you run 150V B+, then each triode in each tube of the Aikido circuit will only have ~75V or less on the plate.
 The two triodes of one tube on the Aikido schematic are in series from B+ to ground. This is how they "share" the PS noise, making this a design with good PSRR.
 If JB says that his fav is 150V B+ using 6DJ8's then I would say you could probably take that to the bank.

  Quote:


 I'm spending more money than I had planned to, 
 

LOL. Welcome to the club friend, I'm glad I'm not alone LOL


----------



## Coreyk78

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_What's the lead spacing on those 2200uF/35V Nich. heater caps, I show about 3.5mm or so on my pcb? Hey I ordered some nice looking Cornell Dubilier 470uF 450V caps from a military surplus guy on ebay and can't wait to try them out as headphone coupling caps. I also got a fair deal on some Holco resistors. It will be interesting to listen to them as well.
 If I may, how did you order the Antek, do you just use PayPal and put the traffo number in the info box when paying? I sent an email about a week ago and have yet to recieve a reply. Maybe I should use the phone
	

	
	
		
		

		
		
	


	




._

 

I pulled up the datasheet, and it says 7.5mm on the lead spacing, I'll have to check and see how those fit the pcb when I get home, they're still sitting in the bag.
 As for ordering from Antek, I actually got this one off their ebay store, saved 3 bucks, haha! But I ordered a pair of toroids for my monoblock chipamp and called them to order, but the woman on the phone actually told me to just send paypal and put your part numbers in the comments because that was the best way to order from them, so thats what I did.

  Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_Just be aware that whatever your B+, each triode will only be getting half(or less that half) of that B+ Voltage, so if you run 150V B+, then each triode in each tube of the Aikido circuit will only have ~75V or less on the plate.
 The two triodes of one tube on the Aikido schematic are in series from B+ to ground. This is how they "share" the PS noise, making this a design with good PSRR._

 

Oh, thats good to know, I didn't realize it worked that way, so it should actually be quite conservative at 150V B+, my minimum cap rating is 200V so I have plenty of headroom there.

  Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_LOL. Welcome to the club friend, I'm glad I'm not alone LOL
	

	
	
		
		

		
		
	


	


_

 

Thanks, happy to be a member 
	

	
	
		
		

		
		
	


	




 but hey, I could think of worse ways to spend money.


----------



## digger945

Quote:


  Originally Posted by *Coreyk78* /img/forum/go_quote.gif 
_I pulled up the datasheet, and it says 7.5mm on the lead spacing, I'll have to check and see how those fit the pcb when I get home, they're still sitting in the bag._

 

Mine measures 7.5mm on the overall diameter, but if your lead spacing will work, you can use a much larger diameter cap here. There is plenty of room.

  Quote:


 As for ordering from Antek, I actually got this one off their ebay store, saved 3 bucks, haha! 
 

I totally didn't know they had an ebay store, must check that out right now.
 Thanks!!!

  Quote:


 But I ordered a pair of toroids for my monoblock chipamp and called them to order, but the woman on the phone actually told me to just send paypal and put your part numbers in the comments because that was the best way to order from them, so thats what I did. 
 

I think I will follow suite and call on the phone also.


  Quote:


 Oh, thats good to know, I didn't realize it worked that way, so it should actually be quite conservative at 150V B+, my minimum cap rating is 200V so I have plenty of headroom there. 
 

FWIW, I am doing the 6H30 witha B+ of 150V, mainly because it is in my user's guide that came with the pcb's. Again, I think if JB recommends it you will be more than satisfied with it.


  Quote:


 Thanks, happy to be a member 
	

	
	
		
		

		
		
	


	




 but hey, I could think of worse ways to spend money. 
 

Oh how true.


----------



## Coreyk78

The 7.5mm lead spacing on the heater caps fit the PCB perfectly, at least on my Rev. 3 board.


----------



## digger945

Just put a pair of PCC88/7DJ8(6DJ8 with 7 volt heater) in my 24V Aikido.
 They sound absolutely fantastic. Bottom end definition is absolutely out of this world, I've yet to hear anything like this.
	

	
	
		
		

		
		
	


	



 TDSL tube data for the PCC88 shows about 90 volts for the plate, I wonder what they would sound like with a little bit more juice.
	

	
	
		
		

		
		
	


	



 A very special thank you to my good friend Ludoo, who sent these all the way from Milan Italy.
	

	
	
		
		

		
		
	


	









 And thanks to dBel84 for forwarding them to me. 
 Thanks Ludo.


----------



## Coreyk78

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_Just put a pair of PCC88/7DJ8(6DJ8 with 7 volt heater) in my 24V Aikido.
 They sound absolutely fantastic. Bottom end definition is absolutely out of this world, I've yet to hear anything like this.
	

	
	
		
		

		
		
	


	



 TDSL tube data for the PCC88 shows about 90 volts for the plate, I wonder what they would sound like with a little bit more juice.
	

	
	
		
		

		
		
	


	



 A very special thank you to my good friend Ludoo, who sent these all the way from Milan Italy.
	

	
	
		
		

		
		
	


	









 And thanks to dBel84 for forwarding them to me. 
 Thanks Ludo.
	

	
	
		
		

		
		
	


	


_

 

Thats good to know, I have my 8 6n23p tubes, and I just got the shipping notification today on my PS-1 kit, and I should have my case from Par-Metal in about a week or so to finish my high voltage build. I'll report back here when its done with what I think of it.

 I also have a second 24v board and an H-PS-1 kit so I could try building a low voltage version too with the same tubes and compare, thats if I feel like spending that much money, haha


----------



## BoilermakerFan

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_Just put a pair of PCC88/7DJ8(6DJ8 with 7 volt heater) in my 24V Aikido.
 They sound absolutely fantastic. Bottom end definition is absolutely out of this world, I've yet to hear anything like this.
	

	
	
		
		

		
		
	


	



 TDSL tube data for the PCC88 shows about 90 volts for the plate, I wonder what they would sound like with a little bit more juice.
	

	
	
		
		

		
		
	


	



 A very special thank you to my good friend Ludoo, who sent these all the way from Milan Italy.
	

	
	
		
		

		
		
	


	









 And thanks to dBel84 for forwarding them to me. 
 Thanks Ludo.
	

	
	
		
		

		
		
	


	


_

 

What? Damn, dB and Ludoo have been holding out on me! 
	

	
	
		
		

		
		
	


	




 Man, I guess things have been crazy busy for me with home life but work has been too slow so my funds are short now. 
	

	
	
		
		

		
		
	


	




 Luckily I do have the trafo for the Aikido already so I may have to just build up the MAXes and gainclones sans toroids for the moment and just listen to the MAXes off a wall wart for DB comparisons. 

 Probably won't be able to make the meet either, but you guys already have the same gear I have, sans the Yamaha YH-3s and SFI orthos I'll be starting in the spring... Oh, and my K601s have just enough differences over the K701s to be audible.


----------



## Coreyk78

Ok, I need some help figuring out if I can use the transformer I already have with the Glassware PS-1 kit.

 I have the Antek AN-1T150 which has dual 150v secondaries, and dual 6.3v secondaries. I just got my PS-1 kit yesterday and the capacitors are 400v, which is a problem if I connect the transformer at 300v series with full-wave bridge rectification, since it will rectify to ~420v.

 The PS-1 has the flexibilty to do either bridge rectifiers or full-wave center-tap rectifiers. Can I use the two secondary leads that are tied together for series as a center tap? I've never used a CT transformer, so I don't know. Assuming I can use it that way though, how much DC voltage should I expect to get with 300-0-300 on a full-wave CT setup? My target voltage after regulation is ~150V so I think if I can get somewhere close to 200v or more before regulation with the CT setup I should be ok.

 I've also considered buying a step up transformer with 230v secondary, but then I need a filament transformer too, so more expensive, or I could upgrade the caps in the PS to higher voltage too I suppose, but I'd like to try and make it work with what I already have first.

 Any advice is welcome!


----------



## BoilermakerFan

Quote:


  Originally Posted by *Coreyk78* /img/forum/go_quote.gif 
_Ok, I need some help figuring out if I can use the transformer I already have with the Glassware PS-1 kit.

 I have the Antek AN-1T150 which has dual 150v secondaries, and dual 6.3v secondaries. I just got my PS-1 kit yesterday and the capacitors are 400v, which is a problem if I connect the transformer at 300v series with full-wave bridge rectification, since it will rectify to ~420v.

 The PS-1 has the flexibilty to do either bridge rectifiers or full-wave center-tap rectifiers. Can I use the two secondary leads that are tied together for series as a center tap? I've never used a CT transformer, so I don't know. Assuming I can use it that way though, how much DC voltage should I expect to get with 300-0-300 on a full-wave CT setup? My target voltage after regulation is ~150V so I think if I can get somewhere close to 200v or more before regulation with the CT setup I should be ok.

 I've also considered buying a step up transformer with 230v secondary, but then I need a filament transformer too, so more expensive, or I could upgrade the caps in the PS to higher voltage too I suppose, but I'd like to try and make it work with what I already have first.

 Any advice is welcome!_

 

I'm not following your train of thought, if 150VDC is your target, then why would you series connect the 150VAC secondaries on the CT? Parallel the 150VAC leads, which be about 210VDC after rectification with double the current, regulated down to 150VDC is fine, that's a 25% delta through the reg so you should be fine in most cases. Check the data sheet for your v-reg just to make sure though, but I don't see the problem. If you are trying to regulate down to 250VDC or 300VDC, then you would need to bump those caps up past 500VDC rating...

 Keep it as simple and clean as possible. That's the Aikido mantra.


----------



## Coreyk78

Quote:


  Originally Posted by *BoilermakerFan* /img/forum/go_quote.gif 
_I'm not following your train of thought, if 150VDC is your target, then why would you series connect the 150VAC secondaries on the CT? Parallel the 150VAC leads, which be about 210VDC after rectification with double the current, regulated down to 150VDC is fine, that's a 25% delta through the reg so you should be fine in most cases. Check the data sheet for your v-reg just to make sure though, but I don't see the problem. If you are trying to regulate down to 250VDC or 300VDC, then you would need to bump those caps up past 500VDC rating...

 Keep it as simple and clean as possible. That's the Aikido mantra._

 

Duh, sorry, I've been sick the last couple days haha. For some reason that hadn't occured to me to just parallel the secondaries, I got it stuck in my head that since there were only 2 AC pads on the board that I needed to series connect them so that I had 2 wires, if that makes any sense of what I was thinking 
	

	
	
		
		

		
		
	


	




 the secondaries are yellow/white, yellow/white. So I should just be able to tie the 2 yellows and 2 whites together and connect that way? Just want to verify since my brain apparently isn't at full function today(or most other days), haha!


----------



## BoilermakerFan

Quote:


  Originally Posted by *Coreyk78* /img/forum/go_quote.gif 
_Duh, sorry, I've been sick the last couple days haha. For some reason that hadn't occured to me to just parallel the secondaries, I got it stuck in my head that since there were only 2 AC pads on the board that I needed to series connect them so that I had 2 wires, if that makes any sense of what I was thinking 
	

	
	
		
		

		
		
	


	




 the secondaries are yellow/white, yellow/white. So I should just be able to tie the 2 yellows and 2 whites together and connect that way? Just want to verify since my brain apparently isn't at full function today(or most other days), haha!_

 

Grab the wiring diagram form AnTek's site to make sure, but that should be correct, tying both yellows and both whites together. You can add a third wire for a single lead at the maximum gauge the PCB will accept and solder the three wires (the 2 secondaries and tail) together, then bring just the tail to the PCB. Or you can use screw terminal blocks and run the two primaries for each leg into one block, the bring a single lead out of the terminal block, but make sure all the lead points are common and not isolated... 

 I'll be using some neat DIN rail mounted miniature terminal blocks for my AC distribution on the PSU side of the Nabu case only because I have gobs of them left over from a failed industrial project and I was giving the hardware. Some neat stuff that I can "repurpose" for audio gear.


----------



## Coreyk78

Good stuff, problem solved, I just mocked it up that way quickly and that should work just fine, thanks for steering me back onto the simple path. 
	

	
	
		
		

		
		
	


	




 Unfortunately the board has 7.5mm spacing on the AC pads, and me terminal blocks are 5mm, so I'll just hardwire it.

 I should now have all the parts to finish my build now, my case from par-metal arrived today, I got gold alodine instead of the clear that I thought I ordered, but I'm gonna use it anyway. Alot of casework and wiring ahead of me now!


----------



## Coreyk78

Also interesting, is that the Antek schematic is not accurate. It shows two 6.3v secondaries, but its actually a 12.6v and a 6.3v.


----------



## digger945

I show the same thing on my 1T150 Corey.
 Bummer, I need at least 4amps 6.3volts for my heaters.
 I think you'll be OK with the 6n23's. Tubedata shows .365 per.
 I bought this from his ebay store because it was advertised as having two 6.3 secondaries, making it flexible to use with both 6.3 and 12.6.
 I'm gonna send an email and see what's up.


----------



## looser101

Quote:


  Originally Posted by *Coreyk78* /img/forum/go_quote.gif 
_Also interesting, is that the Antek schematic is not accurate. It shows two 6.3v secondaries, but its actually a 12.6v and a 6.3v._

 

Very strange. Have you measured it?

 I found these two and they are different, so...

http://www.antekinc.com/AN-1T150.pdf

http://www.toroid-transformer.com/AN-1T150.pdf

 I wonder which one is right.


----------



## Coreyk78

Quote:


  Originally Posted by *looser101* /img/forum/go_quote.gif 
_Very strange. Have you measured it?

 I found these two and they are different, so...

http://www.antekinc.com/AN-1T150.pdf

http://www.toroid-transformer.com/AN-1T150.pdf

 I wonder which one is right._

 

yeah, I measured it last night, unloaded one pair was 13.38 volts, and the other was 6.84v


----------



## digger945

I got 12.7 and 6.5 unloaded.


----------



## looser101

Bummer. Kinda useless if you need more amperage for your heaters.


----------



## Coreyk78

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_I got 12.7 and 6.5 unloaded._

 

your mains voltage must be lower than mine, mine usually sits around ~120v


----------



## BoilermakerFan

Wow, that is a little strange. I wonder if the larger VA or next higher voltage toroid is the same way. Maybe we'll be lucky and it's limited to that model.


----------



## Coreyk78

I thought I had my Aikido built and ready to go last night, but I ran into a big snag.

 My power supply appears to be functioning perfectly, I get 12.58V at the heater supply and ~153V at B+ measured at the supply board.

 The heaters appear to be working just fine, I measure the same voltage at the heater +/- pads at the aikido board and the filaments are glowing. I have installed jumper J3 and J4 so that they run in series parallel with the 12.6v supply and 6.3v heaters.

 The problem is at the high voltage connection. With the power supply connected to the amp board measuring accross B+ and ground I only see about 5V, and the heatsink on the regulator got hot pretty quickly, never blew the 3.15A fuse though. I tried connecting my playstation and playing a cd through to the headphones and while I did get sound it was very badly distorted with lots of static. I disconnected the high voltage supply and checked it again and I still had a solid 153V without it being hooked to the amp board.

 I measured resistance to ground from the B+ pad on the Aikido board and only saw about 64 ohms to ground, which doesn't seem right to me at all. I'm not sure where to start looking for a short, but when I get home I'll be double checking all my resistor values and go from there I guess. If you guys have any other suggestions it would be great.


----------



## digger945

First thought is the wrong value for R5,6,7, or 12. All should be 1M.
 I'm assuming you have the 9-pin stereo pcb.
 Otherwise I'm thinking something in the PS maybe. Running the numbers you gave through PSUD even with a 1ohm load doesn't show voltages that low.


----------



## Coreyk78

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_First thought is the wrong value for R5,6,7, or 12. All should be 1M.
 I'm assuming you have the 9-pin stereo pcb.
 Otherwise I'm thinking something in the PS maybe. Running the numbers you gave through PSUD even with a 1ohm load doesn't show voltages that low._

 

I'm done checking all the resistors, R5,6,7 and 12 are all 1M resistors, they measure at 500k in the circuit, so I'm assuming they must be paralleled, halving the resistance?

 I don't get why the voltage would be 153 unloaded and then drop all the way to 5 when its connected, the regulator only runs a little warm to the touch when unloaded, but its way too hot to touch when connected to the aikido board. I had both boards grounded to the chassis with flying leads to my star ground point, but even when I removed those and completely isolated the boards from the chassis nothing changed at all


----------



## Coreyk78

Oh, and I'm using a 24v Aikido board with high voltage components

 And I'm using all resistor values for a 100v B+, which only R2,4,8 and 11 seem to change between different voltages on the chart, which shows 180R for those positions, maybe they are to low for the higher voltage?


----------



## digger945

Remove the tubes one at a time and check resistance from B+ to ground(with no power of course)


----------



## digger945

Quote:


  Originally Posted by *Coreyk78* /img/forum/go_quote.gif 
_Oh, and I'm using a 24v Aikido board with high voltage components

 And I'm using all resistor values for a 100v B+, which only R2,4,8 and 11 seem to change between different voltages on the chart, which shows 180R for those positions, maybe they are to low for the higher voltage?_

 

Do you have the LM317 outputs populated or are you just using the line out?
 I think 180R should be ok for the biasing.


----------



## Coreyk78

Removing 1 tube at a time it measured ~65R, all tubes removed at the same time measured ~65R as well.

 The solid state outputs are populated, but using IXCY 10M45S mosfets instead


----------



## looser101

The intent of the 24v board was to have the heaters and the main power supply be the same. Looking at the documentation it's not clear to me if there is a jumper that connects H+ and B+ when using a 24v power supply. If you are using a high voltage B+ you have to ensure that it is not connected to the heaters.


----------



## Coreyk78

Quote:


  Originally Posted by *looser101* /img/forum/go_quote.gif 
_The intent of the 24v board was to have the heaters and the main power supply be the same. Looking at the documentation it's not clear to me if there is a jumper that connects H+ and B+ when using a 24v power supply. If you are using a high voltage B+ you have to ensure that it is not connected to the heaters._

 

From what I gather by reading the manual over again, jumper J1 ties b+ to the heater supply. I have J1 open, J3 and J4 have jumpers installed to setup the heater string in series parallel. However, I just measured accross J1 and I only read 3.5R, I would have expected it to be open


----------



## digger945

Do you have the second and third pins on the 10M45's reversed?


----------



## looser101

Quote:


  Originally Posted by *Coreyk78* /img/forum/go_quote.gif 
_From what I gather by reading the manual over again, jumper J1 ties b+ to the heater supply. I have J1 open, J3 and J4 have jumpers installed to setup the heater string in series parallel. However, I just measured accross J1 and I only read 3.5R, I would have expected it to be open_

 

Are you using a PS-1?

 Check R13 and R14 on PS-1


----------



## digger945

Quote:


  Originally Posted by *Coreyk78* /img/forum/go_quote.gif 
_From what I gather by reading the manual over again, jumper J1 ties b+ to the heater supply. I have J1 open, J3 and J4 have jumpers installed to setup the heater string in series parallel. However, I just measured accross J1 and I only read 3.5R, I would have expected it to be open_

 


 Yes, the 24V pcb should have seperate pads and circuit for heaters.
 Facing the 10M45, I am pretty sure the second and third legs need to be switched(crossed)(O and I on the pcb).


----------



## Coreyk78

Yes, I'm using a PS-1, R13 and R14 both measure at 74k.

 The 10M45S are installed on the opposite side of the heatsinks, with lead traces marked as GDS for the outer ones and GAK for the ones closer to the center of the board.


----------



## looser101

Quote:


  Originally Posted by *Coreyk78* /img/forum/go_quote.gif 
_Yes, I'm using a PS-1, R13 and R14 both measure at 74k.

 The 10M45S are installed on the opposite side of the heatsinks, with lead traces marked as GDS for the outer ones and GAK for the ones closer to the center of the board._

 

You are using the rev A board? You don't have to cross the legs on the 10m45... I think?

 R13 should be 300k R14 100k


----------



## digger945

Ah yes, forgot about that, you have the newer pcb. GDS and GAK are the same.


----------



## looser101

Can you pull the B+ and ground connections from the aikido pcb and measure H+ to B+ again, without tubes.


----------



## Coreyk78

Quote:


  Originally Posted by *looser101* /img/forum/go_quote.gif 
_You are using the rev A board? You don't have to cross the legs on the 10m45... I think?

 R13 should be 300k R14 100k_

 

It is the rev A board, the manual didn't say anything about crossing the legs, so I didn't cross them.

 I checked all the baggies that I kept from the PS-1, and R13 and R14 were 300k and 100k respectively, so I'm sure that's what they are. They measure 74k installed though.


----------



## looser101

Quote:


  Originally Posted by *Coreyk78* /img/forum/go_quote.gif 
_I checked all the baggies that I kept from the PS-1, and R13 and R14 were 300k and 100k respectively, so I'm sure that's what they are. They measure 74k installed though._

 

Yes indeed. Mine measures about the same.


----------



## Coreyk78

Quote:


  Originally Posted by *looser101* /img/forum/go_quote.gif 
_Can you pull the B+ and ground connections from the aikido pcb and measure H+ to B+ again, without tubes._

 

I pulled B+/Gnd and H+/H- from the aikido PCB and measuring from the B+ to H+ pads shows infinite resistance.


----------



## looser101

Quote:


  Originally Posted by *Coreyk78* /img/forum/go_quote.gif 
_I pulled B+/Gnd and H+/H- from the aikido PCB and measuring from the B+ to H+ pads shows infinite resistance._

 

Tubes in or out?


----------



## looser101

Can you also measure B+ to ground on aikido pcb.


----------



## Coreyk78

Quote:


  Originally Posted by *looser101* /img/forum/go_quote.gif 
_Tubes in or out?_

 

Oops, that was tubes in, but I just pulled them and its still O.L


----------



## Coreyk78

Quote:


  Originally Posted by *looser101* /img/forum/go_quote.gif 
_Can you also measure B+ to ground on aikido pcb._

 

B+ to gnd pad is 66.4R with tubes in or out


----------



## looser101

Quote:


  Originally Posted by *Coreyk78* /img/forum/go_quote.gif 
_Oops, that was tubes in, but I just pulled them and its still O.L_

 

That's a good thing. I assume you have never used these tubes before. Do you know they are good? Though I don't think that's your problem.


----------



## Coreyk78

Quote:


  Originally Posted by *looser101* /img/forum/go_quote.gif 
_That's a good thing. I assume you have never used these tubes before. Do you know they are good? Though I don't think that's your problem._

 

They are NOS Russian 6N23P, so I assume they are good, the heaters glow anyway...


----------



## looser101

Quote:


  Originally Posted by *Coreyk78* /img/forum/go_quote.gif 
_B+ to gnd pad is 66.4R with tubes in or out_

 

That would draw like ~2amps. Don't think the PS-1 will give you that.

 Try and measure resistance around the 10m45's and match readings left channel to right and hope something is amiss.

 JB never mentioned you could use 2 10m45 per channel? It shows mosfet + 10m45.


----------



## digger945

^That's why I suggested pulling the tubes one at a time and re-measuring B+ to ground(PS disconnected), this would be a quick way to eliminate a bad or shorted tube.


----------



## Coreyk78

Quote:


  Originally Posted by *looser101* /img/forum/go_quote.gif 
_That would draw like ~2amps. Don't think the PS-1 will give you that.

 Try and measure resistance around the 10m45's and match readings left channel to right and hope something is amiss.

 JB never mentioned you could use 2 10m45 per channel? It shows mosfet + 10m45._

 

Ok, if its 2A that is way too much, I think its designed for 50ma, so that would explain the heatsink getting so hot.

 I'll retype part of the paragraph about solid state devices here:

 The IXCY 10M45S constant-regulator is a high-voltage device that works well as the output stage's active load. The output device can be either an additional 10M45S or any high-voltage, low-wattage, N-channel MOSFET in a TO-220 package...(snip)


----------



## looser101

Quote:


  Originally Posted by *Coreyk78* /img/forum/go_quote.gif 
_Ok, if its 2A that is way too much, I think its designed for 50ma, so that would explain the heatsink getting so hot.

 I'll retype part of the paragraph about solid state devices here:

 The IXCY 10M45S constant-regulator is a high-voltage device that works well as the output stage's active load. The output device can be either an additional 10M45S or any high-voltage, low-wattage, N-channel MOSFET in a TO-220 package...(snip)_

 

I think it can supply about 300mA if I understood right.

 I was just about post that about the 10m45.


----------



## Coreyk78

Alright, so assuming that the components are ok and installed properly I need to reduce the current draw somehow?


----------



## looser101

Quote:


  Originally Posted by *Coreyk78* /img/forum/go_quote.gif 
_Alright, so assuming that the components are ok and installed properly I need to reduce the current draw somehow?_

 

The high current draw (ie. low resistance) is an indication of something being amiss. I suspect the output stage. Can you measure resistance from the + side of C4 to B+ and then to ground. Both channels.


----------



## digger945

Just for comparison, I have 12.5ohms +side of C4 to ground. B+ to ground, PS disconnected and heaters disconnected, tubes out, 14.6ohms.
 I am using the DN2540 400V Mosfets and have R15 set at 6.2 ohms and R16 is 1.3 ohms.
 I think we should have pretty close to the same parts values, except for output devices.

 You could always just pull R15 and R16 then see what your PS does then, this would eliminate the output stage.


----------



## Coreyk78

Quote:


  Originally Posted by *looser101* /img/forum/go_quote.gif 
_The high current draw (ie. low resistance) is an indication of something being amiss. I suspect the output stage. Can you measure resistance from the + side of C4 to B+ and then to ground. Both channels._

 

Left- C4+ to B+ = 36.6R
 C4+ to Gnd = 58.9R

 Right- C4+ to B+ = 36.7R
 C4+ to Gnd = 58.8R

 I do have some .047uf bypass caps on those, would that affect anything?


----------



## Coreyk78

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_Just for comparison, I have 12.5ohms +side of C4 to ground. B+ to ground, PS disconnected and heaters disconnected, tubes out, 14.6ohms.
 I am using the DN2540 400V Mosfets and have R15 set at 6.2 ohms and R16 is 1.3 ohms.
 I think we should have pretty close to the same parts values, except for output devices.

 You could always just pull R15 and R16 then see what your PS does then, this would eliminate the output stage._

 

my R15 is 88.7k and my R16 is 100k, so I'm way different than yours, can I ask where you got those values? I was following the recomended values in the manual.

 I may try pulling those resistors and see how it behaves.


----------



## looser101

Quote:


  Originally Posted by *Coreyk78* /img/forum/go_quote.gif 
_I do have some .047uf bypass caps on those, would that affect anything?_

 

Doubt it.

 Diggers build is similar to yours, he may be more help to you than me.


----------



## looser101

Quote:


  Originally Posted by *Coreyk78* /img/forum/go_quote.gif 
_my R15 is 88.7k and my R16 is 100k, so I'm way different than yours, can I ask where you got those values? I was following the recomended values in the manual.

 I may try pulling those resistors and see how it behaves._

 

R18 R17 on yours.


----------



## digger945

Just curious, where did you find the resistor values for R15 and 16?
 I am not finding much on the biasing values for the 10M45.
 I will look some more tomorrow.


----------



## digger945

LOL, yea I read an article on TCJ that had a schematic with the DN2540's in it, but the B+ was the same 24V as I have now.
 I don't have a newer pcb manual. Are the resistor values(R15 and 16) for the LM317 or specifically for the 10M45?


----------



## looser101

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_I am not finding much on the biasing values for the 10M45._

 

Its derived from a graph in the datasheet. 47ohms (R17 in rev A) is about 50mA.


----------



## Coreyk78

I am going off the 1/29/08 version of the 24v pcb manual. Page 11 lists the component values for 12au7, 6cg7, and 6dj8 tubes.

 my r17 is 47 ohms and r18 is 2 ohms


----------



## looser101

Quote:


  Originally Posted by *Coreyk78* /img/forum/go_quote.gif 
_I am going off the 1/29/08 version of the 24v pcb manual. Page 11 lists the component values for 12au7, 6cg7, and 6dj8 tubes.

 my r17 is 47 ohms and r18 is 2 ohms_

 

Looks right. Using 5/30/08 manual Rev A.


----------



## looser101

Have you tried powering up without tubes? Just curious since Diggers resistance readings are also very low.


----------



## Coreyk78

well I removed r17 and r18 and reconnected power. I now have 153v at b+, I'm going to connect a source and see if it makes music thru the line stage.


----------



## manaox2

good luck!


----------



## Coreyk78

eh I got something not quite right yet, lots of static, probably need to look at grounds, but I'm tired tonight so I'll come back to it tomorrow.

 Thanks digger and looser101 for all your input tonight, I really appreciate you taking the time to help me! I think I'm close now to at least getting the line stage working.


----------



## digger945

Quote:


  Originally Posted by *Coreyk78* /img/forum/go_quote.gif 
_eh I got something not quite right yet, lots of static, probably need to look at grounds,_

 

Maybe you can re-install R18 and see how it goes. It is part of the noise voltage divider. I don't see how this could cause a problem if C13 is installed correctly and not shorted.


----------



## looser101

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_Maybe you can re-install R18 and see how it goes. It is part of the noise voltage divider. I don't see how this could cause a problem if C13 installed correctly and not shorted_

 

R18 on his board is part of the output. HERE is a link to the Rev A manual. Look at page 11.

 Corey, do you have R19, C2 populated?


----------



## digger945

Ahh I see. Thanks, I've been looking for this user's manual. This would make most of what I've suggested so far incorrect, or at least the part numbers.


----------



## Coreyk78

Quote:


  Originally Posted by *looser101* /img/forum/go_quote.gif 
_R18 on his board is part of the output. HERE is a link to the Rev A manual. Look at page 11.

 Corey, do you have R19, C2 populated?_

 

R19 and C2 are populated.


----------



## looser101

So without the output stage - its noisy? Both channels? Have any other tubes you can try? Can you describe the noise?

 Thanks


----------



## digger945

It may be somewhat redundant to what you've already checked but I'll ask anyway.

 Are the 10M45's isolated from the heatsinks, and are you sure R17 is indeed 47ohms. Reason I ask is I did this once, got R17 and 18 mixed up.


----------



## Coreyk78

ugh, I've been out of town a few days unexpectedly and been to busy to get back to my Aikido. But I should be able to spend some time on it tonight.

 I do have 8 tubes, so I may try swapping them out to see if there is any difference. Is it possible that i could have harmed the tubes before with the short problem in the headphone buffer?

 As for the noise, it basically sounds like total garbage, extremely weak signal, with lots of static and it all sounds really muffled. The crappiness is equal between channels. The only source I've connected so far has been my playstation that I use as a CDP, but it sounds great if I connect that directly to my Millet, so its working properly.

 Without the board screwed down to the standoffs if I wiggle it a bit I got some really nasty pops as well. I've tried eliminating everything off the board by disconnecting my input selector switch and pot and wiring a pair of rcas directly to the inputs on the board. Didn't seem to make any difference. 

 I have 6 pairs of input rcas on my case, and they all share ground to the aikido board, but are isolated from the chassis. I also have ground wires going from the Aikido board and PS-1 board to the chassis star ground.


----------



## digger945

My pcb has a pad for chassis ground, but it's isolated from PS ground by the J2 jumper. I don't have it hooked up, my amp isn't in a case.
 I do remember trying to connect the HP ground directly to the source ground and it sounded really bad. Both the source ground and HP ground had to be connected to the pcb ground(input and/or output grounds, doesn't matter on mine).

 Note: You might also probe the heaters just to see that everything is OK.(pins 4 and 5)


----------



## Coreyk78

theres definitely something going wrong with the power. I just powered it up briefly to check voltages. I got 153.5 at b+ which I expected, but I have 50V at H+, I don't know What is going on that would cause that, I powered it off as soon as I saw that.

 edit- I disconnected the heater supply from the board and powered up again, 0v at h+ pad which is good, I was thinking some of b+ was somehow leaking to the heater circuit.
 However, I now have 50v at h+ on the power supply, which is really strange, since it was 12.6v last week.


----------



## digger945

Are you using the heater supply on the PS-1 or a seperate supply like the H-PS-1?


----------



## Coreyk78

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_Are you using the heater supply on the PS-1 or a seperate supply like the H-PS-1?_

 

I'm using the heater supply on the PS-1, I have no idea what could have happened to it though. It was putting out 12.59v last week when I first tried it out.


----------



## digger945

I dunno, maybe something changed if and when you cased it up, or a piece of metal, maybe a resistor lead, has found it's way across two traces.
 You have a pic?


----------



## looser101

Quote:


  Originally Posted by *Coreyk78* /img/forum/go_quote.gif 
_I'm using the heater supply on the PS-1, I have no idea what could have happened to it though. It was putting out 12.59v last week when I first tried it out._

 

Did you measure H+ to H-? The heater is elevated above ground by B+/4, so measurements to ground will lead you astray.


----------



## Coreyk78

Quote:


  Originally Posted by *looser101* /img/forum/go_quote.gif 
_Did you measure H+ to H-? The heater is elevated above ground by B+/4, so measurements to ground will lead you astray._

 

Oh, well I guess that mystery is solved then, because I did measure it to ground


----------



## looser101

Quote:


  Originally Posted by *Coreyk78* /img/forum/go_quote.gif 
_Oh, well I guess that mystery is solved then, because I did measure it to ground
	

	
	
		
		

		
		
	


	


_

 

One mystery solved.


----------



## digger945

So how's it goin' Corey?


----------



## Coreyk78

unfortunately I haven't been able to spend much time on my Aikido, I might try poking around at it a little tonight, I just got done changing out the radiator in my car, if it's not one thing its another, hehe.


----------



## BoilermakerFan

Quote:


  Originally Posted by *Coreyk78* /img/forum/go_quote.gif 
_unfortunately I haven't been able to spend much time on my Aikido, I might try poking around at it a little tonight, I just got done changing out the radiator in my car, if it's not one thing its another, hehe._

 

Amen to that Corey! I'm still cleaning up my yard from the damage of the ice storm that pounded Southern Indiana and Kentucky.


----------



## Coreyk78

I couldn't find my camera because my daughter had been playing with it, but I found it tonight, hehe. Here's a pic of the top and bottom of my board, I removed it from my chassis to check it over for anything obvious and to clean the flux off the bottom just in case.


----------



## looser101

Nothing jumps out at me from the pics. Interestingly, I'm having issues with my PS-1 (recently installed). My Aikido draws close to 100mA and the psu refuses to regulate with that load. Yours draws a bit more, so it's possible that we are having the same problem. As soon as my tubes start conducting my voltage drops off 20-30v from where it's set at. Well, back to the drawing board.


----------



## digger945

I've looked her over and don't see anything either Corey.
 Based on what both you and looser101 say, it makes one want to look at the PS some more.
 Maybe we could share a pic of the PS-1.

 EDIT:Are there resistors behind those heatsinks in the top pic?


----------



## Coreyk78

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_I've looked her over and don't see anything either Corey.
 Based on what both you and looser101 say, it makes one want to look at the PS some more.
 Maybe we could share a pic of the PS-1.

 EDIT:Are there resistors behind those heatsinks in the top pic?_

 

No, I have those removed right now, those are R18, I can post some pics of the PS-1 a little later today


----------



## looser101

I emailed JB earlier today. Lets hope he replies with some answers as to why we are having these issues.


----------



## fran

Is it the PS1 or H-PS-1 you guys are using?

 Fran


----------



## looser101

PS-1 - The high voltage version which has a H-PS-1 attached for the tube heater.

PS-1 Solid-State Regulator Kit


----------



## fran

Is your problem with the high voltage only or do both supplies sag under the load? Really sounds like you have no regulation so when you set the voltage with no load its "floating" and then when connected to a load it drops.

 This wouldn't be something to do with the way he floats the heaters off ground would it? There isn;t a jumper or something in there to select that option?

 Fran


----------



## looser101

Quote:


  Originally Posted by *fran* /img/forum/go_quote.gif 
_Is your problem with the high voltage only or do both supplies sag under the load? Really sounds like you have no regulation so when you set the voltage with no load its "floating" and then when connected to a load it drops.

 This wouldn't be something to do with the way he floats the heaters off ground would it? There isn;t a jumper or something in there to select that option?

 Fran_

 

Hi Fran. I'm currently using separate trannies for the supplies. There is no sag in the heater supply. There is also no significant sag in the raw DC in the HV supply, and there is plenty of voltage across the regulator. Output voltage is set like any other 3 pin adjustable regulator. The only difference is the addition of the IXYS 10M45s to isolate the regulator from the high voltage. The voltage is exactly what you would expect until the tubes start to conduct, at which point the voltage drops off. JB is not clear as to how much current the PS-1 can supply. I'm drawing close to 100mA and I'm starting to think the 10M45 is not happy at these current levels and goes into current limiting. Still waiting for a reply from JB.

 Cheers

 Renato


----------



## BoilermakerFan

Quote:


  Originally Posted by *looser101* /img/forum/go_quote.gif 
_Hi Fran. I'm currently using separate trannies for the supplies. There is no sag in the heater supply. There is also no significant sag in the raw DC in the HV supply, and there is plenty of voltage across the regulator. Output voltage is set like any other 3 pin adjustable regulator. The only difference is the addition of the IXYS 10M45s to isolate the regulator from the high voltage. The voltage is exactly what you would expect until the tubes start to conduct, at which point the voltage drops off. JB is not clear as to how much current the PS-1 can supply. I'm drawing close to 100mA and I'm starting to think the 10M45 is not happy at these current levels and goes into current limiting. Still waiting for a reply from JB.

 Cheers

 Renato_

 

Well, the 10M45S is a current regulator, if you look at the data sheet if the input voltage is less than -2.0V than the plateau current will be 100mA or less. It looks like the max it will pass is 400mA.

http://www.datasheetcatalog.org/data...ehw1hso9yy.pdf


----------



## digger945

I just copied this from the Glassware Yahoo PS-1 info page:

 "Kit does not include a power transformer, but works with transformers between 200V to 550V center-tapped, with 6.3V or 12.6V windings. *The PS-1 can deliver up to 50mA of high voltage* and is the prefect choice for a line stage amplifier or a phono preamp."

 Maybe we need to look for a good PS design witha bit more current, like 100mA or more, or see what JB has to say back to looser101 and go from there.


----------



## Coreyk78

yeah I had read the 50mA stuff too. Maybe a simple unregulated supply with an isolation transformer and some smoothing caps would work for my application since 120vac would rectify to 168v, which would be close enough for my application, and my caps are all 200v or higher anyway. If I do need to go that way its kind of a bummer that I dropped 80 bucks on a PS-1 I can't use.


----------



## digger945

^Yea, I need only a high voltage PS to do my 9pin mono Aikido, I have been puttin so much $ into the Dynamite the past few months I haven't had any left over for anything else.
 From what I'm able to gather, the 6DJ8/6N23P is gonna want somewhere in the range of 20mA cathode current (each) at 90V, and that's a little less than the rated (some data pages) 3 to 4 watts dissapation.

 Let's hope with some advice from JB we can mod the PS-1 to give just a little more current.


----------



## BoilermakerFan

What voltage do you guys want after final DC regulation? I might have a schematic that can be tweaked to work. It's designed to feed 300B monoblocks, so current limits really won't be an issue.


----------



## digger945

I'de like to see somewhere in the 150 to 200v range, with a minimum of at least 160mA, 200mA would be better.
 This should be adequate for 4 6H30's.

 I thought about that Janus shunt regulator, but it doesn't specify the output current, only that you shouldn't expect it to supply an amp full of KT-88's. Also the usable voltage range seems to be 250-300V.


----------



## BoilermakerFan

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_I'de like to see somewhere in the 150 to 200v range, with a minimum of at least 160mA, 200 would be better.
 This should be adequate for 4 6H30's._

 

Well 170VDC is obtainable after rectification after an isolation transformer, then regulated down to 150V.

 135V secondaries would net 190VDC before regulation so it could be dropped to 165-175V and stay under the limit of 200V caps. 

 I'll dig up the schematic later tonight.

 Not looking for a pity party, but I was laid off Friday so I'll have a little extra time to spend actually getting my basement workshop set up and building some stuff while looking for a new career. I'm staying away from any companies tied to automotive, construction equipment, appliance industry or transportation vehicles.


----------



## digger945

Yes well it seems we have been averaging 10 a week where I work, 24 this past week. I am getting a little concerned now. We are parts manufacturers and suppliers to the RV/Manufactured housing industries, and were it not for several government contracts for FEMA units we would probably be in sad shape.
 I really don't want to believe it could get much worse here, we are number one for unemployment in the nation now, you may have heard Obama mention the city of Elkhart in his speech last week. Unemployment is estimated by the Mayor to be over 20% within the city limits.

 I am very thankful and fortunate to still have a job in these parts.


----------



## Coreyk78

I'd be looking for 150-190v for my Aikido. 

 Also on the employment stuff, my Dad was laid off in January, and he's a professional Civil Engineer with over 30 years of experience, times are tough all over.

 The city I work for is looking at having to make a 30 million dollar budget cut for this year and 40 million next year because of lost local government aid funding from the state. I've only been there about 2 years so unfortunately I'm not very far up the seniority ladder if layoffs end up being part of those budget cuts...


----------



## looser101

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_I just copied this from the Glassware Yahoo PS-1 info page:

 "Kit does not include a power transformer, but works with transformers between 200V to 550V center-tapped, with 6.3V or 12.6V windings. *The PS-1 can deliver up to 50mA of high voltage* and is the prefect choice for a line stage amplifier or a phono preamp."

 Maybe we need to look for a good PS design witha bit more current, like 100mA or more, or see what JB has to say back to looser101 and go from there._

 

Certainly the 50mA limit was not on that page before, I would of noticed. I guess he did get my email? Hopefully he will get back to me with a possible fix. Anybody know how to best parallel a couple 10M45?

 I was using an isolation transformer and CLC psu and thought the PS-1 would be an improvement, even though I had no complaints. Oh well, live and learn.

 Sorry to hear about your job woes. I hope everyone can hang in there until the economy turns around. All the best.

 R


----------



## digger945

I see no reason why the PS-1 can't be salvaged and simply modified to deliver a bit more current. If the 10M45 is indeed good for 400mA then it is possible.


----------



## looser101

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_I see no reason why the PS-1 can't be salvaged and simply modified to deliver a bit more current. If the 10M45 is indeed good for 400mA then it is possible._

 

The chart in the datasheet shows a possible 400mA but the same datasheet claims an absolute max current of 300mA. JB actually shows the chart of the 10M90s on his website (check my earlier link) when explaining how the PS-1 works. I'm starting to think that chart is probably more true to reality in our case. If the 10M45s can be easily paralleled then we may be able to salvage the PS-1 for our use.


----------



## looser101

Well, I just happened to have some extra 10M45s on hand. So I think to myself, why don't I tack-on another one in parallel? The Aikido goodness is back 
	

	
	
		
		

		
			





. And its not even heatsinked. It's a 40w device and I have 50v across it and 50mA through it, so that's only 2.5w. So now I figure it's good for 100mA, and in my current case it's all I need. 

 Cheers

 R


----------



## digger945

It is really good to see that 2 devices paralleled works great.

 By saying "The Aikido goodness is back" you mean it sounds better now than before?
 Do you think that 2 parallel 10M45's will put out enough juice to run Corey's SS output on his amp?

 Do you think the IRF840 might make a suitable one-device-replacement if properly implemented and set up? It looks like it's rated at 500V/8A/125W.

 Another thing I wanted to mention is the specs on the AnTek 1T150 torroid. Maybe if the secondaries where wrong then other specs could be wrong. The AN-1T150 datasheet shows the HV output to be 106W. 100VA * 0.6Pf / 150V = .4A or 400mA. If the spec sheet is correct this seems like it would be plenty. According to the spec sheet at max 106W output at 137V you should see .8A, double what the above calculation shows with the 0.6Power factor multiplier. Either way it looks like plenty. Could the low voltage secondaries used for the heaters be taking some of the power away from the high voltage secondaries?

 Another calc that I did says that a 40W device(10M45) at 150V will pass 260mA, so if your maxing out the current, I think the voltage will decrease a bit, and that sounds just like what you guys were experiencing. OK at idle, then a voltage drop when you put the load on.


----------



## looser101

I haven't been able to listen to the Aikido for a bit but I think it sounds the same as it used to. It sounded dreadful when the PS-1 was acting up.

 Corey is probably going to need 3 of them since he'll be drawing 100mA just in the output stage. It seems we are limited to 50mA per 10M45. You would need 4 if you are going to bias your input tubes hot (I didn't).

 You can't use a standard mosfet in this case, you need to use a depletion mode mosfet. If I were you and had a DN2540 I would try one of those instead of the 10M45 since it seems to have a higher current capacity, but a lower power dissipation.

 I am using the 1T150 now as well. That was the first change I made when I had trouble with the PS-1. The raw DC was kind of low with the isolation transformer I had been using. I thought that was the problem, so had to rule that out.

 I'm not using the heater windings as of yet, the 150vAC secondaries are paralleled and my raw DC is now ~192vDC and it's not even warm at 100mA draw.

 The voltage on the 10M45 is (raw DC - the output DC). Multiply that by the current (which in this case seems to be limited to ~50mA) and that's it's power dissipation.


----------



## digger945

I bought 2 cheap Hammond 6.3V/3A transformers to go with the 2 H-PS-1 pcb's that I traded manaox for, one complete heater PS for each mono pcb.

 Yes I thought about the DN2540. It's a 15W device but may handle the current better here. I think I figured 100mA for the DN2540 at about 150V. JB refers to the 2540 as "wimpy" in his PS-1 article.
 I think I'm gonna just add the parts necessary to build a PS-1 on breadboard since I don't have the extra $ right now. That's all I need to fire up this amp, I even bought some Raytheon 6FQ7's from Krmathis to try for the input positions.
 I still wanna know what JB has to say about it all.


----------



## looser101

Raytheon 6FQ7's are very nice. Better than RCA cleartops IMO. Make sure you use the right bias resistors.

 If you need any parts let me know. I have a big box full of stuff.


----------



## digger945

I think I have ordered enough Vishay resistors in all values necessary for every possible tube combination in the user's guide, plus all the ones you recommended for the 4 x 6H30 setup, cathode resistors caps also.
 I'll do the 6FQ7/6H30 first then go all 6H30 (these are the Sovtek's I got when Microsoft had the Live.com discounts).
 I _could_ go ahead and get started now


----------



## Coreyk78

Well hopefully I'll be able to solve my problem now, I'll have to order some more 10M45s.
 I wonder how I should install the extra mosfets, solder directly to the legs of the one on the board, or put a couple of them on some perfboard.


----------



## looser101

Quote:


  Originally Posted by *Coreyk78* /img/forum/go_quote.gif 
_Well hopefully I'll be able to solve my problem now, I'll have to order some more 10M45s.
 I wonder how I should install the extra mosfets, solder directly to the legs of the one on the board, or put a couple of them on some perfboard._

 

I would hang tight until someone tries a DN2540. Hopefully Scott has one he can use and report his results. Or if he has extras I would gladly try one out.


----------



## digger945

I'm ordering extras(DN2540N5's) with the PS-1 parts. I guess I'll order 4 of the 10M45S since my amp won't have a SS output.
 I need to find some kinda BOM for the PS-1 so I don't miss anything.

 I'm guessing this will work...








 The top schematic is the one I will use(full wave), the bottom one is just to fill in some values.
 The PS-1 product site has both MUR410G and HER108 rectifiers in the list. Use either one for D1 thru D4?
 Wattage for R1-R4?
 I'm guessing 1000pF/1000V should be ok for C1-C4?
 Polars are Panasonics? Where do the RTI's go? I'll probably use something else for the RTI's.


----------



## looser101

PM me your email and I'll scan the BOM and send it to you.


----------



## digger945

I ordered a bunch of stuff from Mouser yesterday. I got a few things to play with, DN2540 and 10M45 of course, also the IRF840 and FCP4N60 just to tinker with later to see how they might work. I don't find much info online about running regulators parallel. I don't know if the circuit I am building will be helpful unless I also include(and load) the heater circuit, so I am gonna have my H-PS-1's ready to add to the circuit if needed. I don't think they will matter much to the HV circuit, loadwise.


----------



## looser101

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_I ordered a bunch of stuff from Mouser yesterday. I got a few things to play with, DN2540 and 10M45 of course, also the IRF840 and FCP4N60 just to tinker with later to see how they might work. I don't find much info online about running regulators parallel. I don't know if the circuit I am building will be helpful unless I also include(and load) the heater circuit, so I am gonna have my H-PS-1's ready to add to the circuit if needed. I don't think they will matter much to the HV circuit, loadwise._

 

Surprisingly my 10M45S (without heatsink), that I paralleled with the one on board, is still going. It has been on pretty much every night whether I've been listening or not. I found one thread on paralleling the 10M45S and the answer was yes and no. I'm inclined to believe Dave Davenport. 






 Above is the equivalent circuit for the 10M45S. As you can see it is a composite device and not a depletion mode mosfet, even though it acts like one. The chart in the datasheet that pertains to its use in the PS-1 shows the relationship between a voltage applied from G to K and how much current will flow from A to K. So applying the same voltage on G,K of two or more parallel devices would flow the same current through each device, without affecting each other. Well, that's my theory anyway.


----------



## BoilermakerFan

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_I ordered a bunch of stuff from Mouser yesterday. I got a few things to play with, DN2540 and 10M45 of course, also the IRF840 and FCP4N60 just to tinker with later to see how they might work. I don't find much info online about running regulators parallel. I don't know if the circuit I am building will be helpful unless I also include(and load) the heater circuit, so I am gonna have my H-PS-1's ready to add to the circuit if needed. I don't think they will matter much to the HV circuit, loadwise._

 

I don't think the IRF840 is a depletion mode FET. The IRF510 and IRF610 can be used in the MOSFET position in the buffers though. The 540 wouldn't work, but I forget why...


----------



## Coreyk78

I'll be watching closely to see how it goes for you digger. I'm itching to get my Aikido working, hehe.


----------



## digger945

I'm studying the schematic for the sigma22 PS I'm about to assemble and looking at the printout of the PS-1 schematic and comparing the two. I did some digging and learned some stuff about the differences between depletion mode and enhancement mode MOSFET's. I think I will order the  IRFB4332PBF on the next Digikey order to tinker with. Until then I will focus on implementing the DN2540(first victim lol).

 I don't know if I mentioned that I am now listening to a pair of GE 6DJ8's I picked up from Skylab a week or two ago. I have them in the output positions. Skylab sold me on these by complimenting the mids, and he was right. They sound pretty good so far.
	

	
	
		
		

		
		
	


	




 And here is yet another link Aikido Line Stage Amplifier Kits & More FBFF Hybrid Regulators to a regulator circuit involving the 10M45.


----------



## BoilermakerFan

Heh heh. I'm waiting on Ludo to pick up the felt then ship it and some tubes to me.

 I need to read through the last 3 months of JB's posts to get caught up. 

 I actually made progress in my basement storage conversion to a shop yesterday. I was able to get all my crap out of the storage area and move the big industrial shelving unit out (6' long x 18" deep x 60" tall) and over to different part of the basement utility area. The basement is 80% finished space, 20% utility/storage. I have room for a 60" long x 18"-24" deep workbench as well as shelving. I may drop to a 48" long workbench to allow easy use of replaceable 2'x4' tops so I can do a wood, masonite, MDF, PE plastic cutting board, or metal top. I'd change out tops depending on the task I'm working on. Then I'd also have room for a small downdraft spray booth. Small in the sense that it would be about 3' square on the base and 5-6' tall so I could spray all my RC boat hulls, car bodies, audio chassis, and reasonable sized speakers. I'd only spray water-based non-flamable finishes so I could avoid explosion proof fans and lighting. 

 Anyways, As soon as I get the basic carcass for the workbench done and wire up some new 120V and 240V outlets, I can start building the Aikido while I wait for the new V1.2 of the MH MAX boards to arrive at Tom B's. Selling off 2 of my 3 older versions and building up the one remaining as a Muse ES/VitQ build to compare side-by-side with the two newer ones, then I'll sell the amp to my buddy along with a set of SFI driver custom cans or just woodied Grado SR-125s. 

 On a positive note, I received everything I expected in my severance package and a little more, so that was some good news yesterday and today.


----------



## Coreyk78

I've decided to forge ahead and build a new power supply.
 I picked up a cheap Amveco medical isolation transformer with dual .83A 120v secondaries off ebay, and I got a 12.6v filament transformer from digikey that I will use with the H-PS1 I already have for the heaters, along with all the other parts needed to build the simple unregulated power supply with a choke from the 9-pin Aikido manual. I figure that if I'm going to be a DIY guy then I need to do it myself sometimes too, hehe. 

 Should be a fun adventure and a good experience. This PS should be able to supply more than enough current for my Aikido.


----------



## looser101

Quote:


  Originally Posted by *Coreyk78* /img/forum/go_quote.gif 
_I've decided to forge ahead and build a new power supply.
 I picked up a cheap Amveco medical isolation transformer with dual .83A 120v secondaries off ebay, and I got a 12.6v filament transformer from digikey that I will use with the H-PS1 I already have for the heaters, along with all the other parts needed to build the simple unregulated power supply with a choke from the 9-pin Aikido manual. I figure that if I'm going to be a DIY guy then I need to do it myself sometimes too, hehe. 

 Should be a fun adventure and a good experience. This PS should be able to supply more than enough current for my Aikido._

 

Good for you. Let me know if you need any parts. I have a choke gathering dust right now...


----------



## Coreyk78

I ordered a hammond 1536X choke which is 250uH with 2.5A current capacity, hopefully that will be large enough to make a difference, if not I'll step up to one of the larger open frame chokes, the 1536X was only a few bucks.


----------



## digger945

I look forward to seeing what you come up with Corey, and let me know if you have any ideas that you want to try out, I'm expecting the Mouser order to come in tomorrow, I got the Digikey stuff and some film caps from ebay yesterday. Proto board and transformer are on the workbench now.


----------



## Coreyk78

My digikey order should be in by tomorrow, that's at least one advantage to living in the Minnesota cold, I get my parts fast. I'm going to stop by Radio Shat today and pick up some perfboard to build it on, and hopefully I'll have some free time this weekend to tear into it.
 I might look into adding regulation later once I get the unregulated supply working. I should have just gone this way from the start, all the parts including the transformers were less than 50 bucks. Thats not including the H-PS1 that I originally bought when I thought I was going to build a 24v version, luckily I only had to change 1 resistor on that board to change it from 25.2v to 12.6v output.


----------



## digger945

I got my parts today, UPS man was late. I have the PS-1 built on the proto board. Did you use both of the primaries(red and black) and both of the secondaries(yellow and white) on the 1T150?
 I'm gonna put wall power to it and just probe around, then I'll put a load on it. I have two 75ohm 50W power resistors to use for the load if I can get by with it. I can't find my amp gauge, I think I left it at a friend's house. I will use the 10A setting on my DMM and see how it goes. If I don't need to call 911 I'll post a pic in a few minutes.


----------



## looser101

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_I got my parts today, UPS man was late. I have the PS-1 built on the proto board. Did you use both of the primaries(red and black) and both of the secondaries(yellow and white) on the 1T150?
 I'm gonna put wall power to it and just probe around, then I'll put a load on it. I have two 75ohm 50W power resistors to use for the load if I can get by with it. I can't find my amp gauge, I think I left it at a friend's house. I will use the 10A setting on my DMM and see how it goes. If I don't need to call 911 I'll post a pic in a few minutes._

 

Yes use both primaries and secondaries in parallel.

 Edit: You will know if it's working properly if the voltage remains constant under load. ie. voltage across the load resistor. When it goes into current limiting the voltage will drop.

 Edit 2: I just realized that the 75ohm load resistors are way too small. Even in series they will draw 1amp. You need about 750ohms.


----------



## digger945

Do you think that(750ohms) will adequately represent Corey's amp with the SS output?
 I have a bunch of extra resistors I got for the PS-1 maybe they can be made to work.


----------



## looser101

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_Do you think that(750ohms) will adequately represent Corey's amp with the SS output?
 I have a bunch of extra resistors I got for the PS-1 maybe they can be made to work._

 

Pretty sure it will. His biggest draw is the output stage at 100mA. I doubt the tube section is drawing more than 100mA in total. 750ohms load resistor will draw 200mA with 150v supply. Should be close.


----------



## digger945

How about 3 x 249ohm 1/2W? 
 As of right now(unloaded) I get 147AC at the secondaries, 195DC both pre and post regs, I'm using the 10M45 to establish a baseline. 
 Also I do not have R13 and R14 in place at the output, so maybe I can add that, but I really hate to as Corey (mee too) aren't going to use the heater portion of this PS.


----------



## looser101

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_How about 3 x 249ohm 1/2W? 
 As of right now I get 147AC at the secondaries, 195 both pre and post regs, I'm using the 10M45 to establish a baseline. 
 Also I do not have R13 and R14 in place at the output, so maybe I can add that, but I really hate to as Corey (mee too) aren't going to use the heater portion of this PS._

 

3x249 should be fine. If you used 30k for to set your voltage out to 150v then your circuit is not regulating.

 R13/R14 can be added later.


----------



## digger945

For R6 and R7 I used 15k each. 
 Only other variations are C7 is .1uF instead of .01uF, and...
 C6 and C9 I used 2.5uF instead of 4.7uF.
 And as I mentioned I omitted R13, R14 and C18. Everything else is exact spec per the BOM you sent. Rectifiers are HER108's, diodes are 1N4007's.
 For C5 and C8 I used Panasonic TS-ED 150uF 400V Digikey Part Number: P11649-ND.


----------



## Coreyk78

Do you have it built in standard configuration now or are you using multiple 10M45s in parallel? Or did you try the DN2540 right away?


----------



## digger945

Here's a pic of what I have.
 I gotta hit the sack, we will have another look at it tomorrow.


----------



## looser101

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_For R6 and R7 I used 15k each. 
 Only other variations are C7 is .1uF instead of .01uF, and...
 C6 and C9 I used 2.5uF instead of 4.7uF.
 And as I mentioned I omitted R13, R14 and C18. Everything else is exact spec per the BOM you sent. Rectifiers are HER108's, diodes are 1N4007's.
 For C5 and C8 I used Panasonic TS-ED 150uF 400V Digikey Part Number: P11649-ND._

 

Look around your regulator for a problem. Your components seem fine.


----------



## digger945

A single 10M45 is what I started with. I have all the other's including the DN2540.
 It's wired exactly as the schematic.
 We'll have another go at it tomorrow. I'm sure I have something misplaced somewhere.


----------



## looser101

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_A single 10M45 is what I started with. I have all the other's including the DN2540.
 It's wired exactly as the schematic.
 We'll have another go at it tomorrow. I'm sure I have something misplaced somewhere._

 

Jumper from junction of R5 + R6 to Adj pin on reg?


----------



## digger945

I think that's it. I have that jumper to "output"(center pin on 1085) and nothing connected to "adjust" except R8/C7.


----------



## Coreyk78

I'm trying to understand what the ratings on a choke really mean.

 example: a choke is rated at 1.5H and 200mA with 400VDC max voltage.

 is that rating showing the inductance at that current, with inductance rising with less current and lowering with higher current? Or is the 200mA the max current the choke can pass?


----------



## digger945

You were right Renato. Hooked up the adjust pin on the 1085 to the node on the schematic between R5 and R6 and now I get 201.6VDC pre and 149.3 post regs.
 I will do some more testing as soon as I get back from the dentist(ugh). It's gonna be easy to just plug in the DN2540 on this board when we get to that point.

 One thing that I need to think about is that I believe the 2540 will pass all current until the gate is pulled negative with respect to (I forget).


----------



## looser101

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_You were right Renato. Hooked up the adjust pin on the 1085 to the node on the schematic between R5 and R6 and now I get 201.6VDC pre and 149.3 post regs.
 I will do some more testing as soon as I get back from the dentist(ugh). It's gonna be easy to just plug in the DN2540 on this board when we get to that point.

 One thing that I need to think about is that I believe the 2540 will pass all current until the gate is pulled negative with respect to (I forget)._

 

Just make sure the caps have discharged before you touch the metal tab on those devices.

 There is always a negative voltage on the device equal to the voltage drop across the regulator. ~1.3v


----------



## Coreyk78

Quote:


  Originally Posted by *Coreyk78* /img/forum/go_quote.gif 
_B+ to gnd pad is 66.4R with tubes in or out_

 

 Quote:


  Originally Posted by *looser101* /img/forum/go_quote.gif 
_That would draw like ~2amps. Don't think the PS-1 will give you that.

 Try and measure resistance around the 10m45's and match readings left channel to right and hope something is amiss.

 JB never mentioned you could use 2 10m45 per channel? It shows mosfet + 10m45._

 

I was going back and re-reading some of this, if my Aikido is going to be drawing ~2A with the solid state output, then I may have bought an undersized transformer for my CLC power supply. Its rated at .83ma


----------



## looser101

Quote:


  Originally Posted by *Coreyk78* /img/forum/go_quote.gif 
_I was going back and re-reading some of this, if my Aikido is going to be drawing ~2A with the solid state output, then I may have bought an undersized transformer for my CLC power supply. Its rated at .83ma_

 

You can disregard that info. My best guess is that your amp will draw < 200mA. 50+50mA for the output stages and < 100mA for the tube sections.


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## Coreyk78

Quote:


  Originally Posted by *looser101* /img/forum/go_quote.gif 
_You can disregard that info. My best guess is that your amp will draw < 200mA. 50+50mA for the output stages and < 100mA for the tube sections._

 

Oh ok, thats good news then, the 830mA from the transformer will give plenty of headroom. 

 I built up the CLC power supply from JB's schematic in the user guide last night, I used a tiny 250uH choke just to test things out, I'm going to need a much larger choke though, I was thinking uH was mH, my mistake. Anyways, with the isolation transformer I ended up with 181VDC with the power supply unloaded, using 1000uF 200V caps at C1 and C2. 

 I hooked it up briefly and actually got some sound from my Aikido, but with a heavy oscillation type of noise, especially in the right channel, there actually was no music from the right channel, just hum, but I think I messed up the ground wiring on my pot too, not sure, it was late.

 I was looking through the Hammond chokes, and I saw one around 1.5H and 500mA, so I'll probably order that one, should hopefully cut down the hum and the higher DCR should hopefully drop some voltage as well, 181V is quite a bit more than the ~168V I was expecting to get. In fact, with a choke only a little bit smaller than the 250uH, say 100uH the simulation wouldn't even run in PSUD2, so the choke is way undersized. Still, I feel like I'm making progress now and I know what I need to do


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## Coreyk78

Oh, and I'm thinking I should definitely add some bleeder resistors to the power supply caps, about 15 mins after I turned off power to the supply, I accidentally shorted the leads of one of the caps with my test probe and got a nasty explosion of sparks, almost crapped my pants, haha! 

 I tested the voltage after I powered it up and down again later on, and the caps still had over 60v in them about 15-20 mins after I shut it off. 

 Also, is there a need to ground the 0V side of the rectifier bridge directly to earth at the power supply, or will it be ok to let it find its way to ground through the Aikido board's ground?


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## digger945

Are you going with the same basic layout and components as the PS-1 Corey, just adding the inductor/choke to the circuit?
 I know there are so many different schematics online, and especially at tubecad.
 It looks like in the original PS-1 circuit that R5, R6 and R7 make one connection between B+ and ground to help bleed off, and I know the circuit I built is below 1V in probably about 10 to 15 seconds after I kill the power, however I don't assume that every last bit of juice has been dissapated out of C5 and C6 through the 10M45/LD1085. I am going to put the resistor load on it tonight and then try the DN2540 after I take some measurements to see how the two compare. 
 I hope 747 ohms(3 X 249ohm 1/2watt) is a pretty good estimate of actual working conditions. I think it will be close enough for testing purposes.


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## Coreyk78

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_Are you going with the same basic layout and components as the PS-1 Corey, just adding the inductor/choke to the circuit?
 I know there are so many different schematics online, and especially at tubecad.
 It looks like in the original PS-1 circuit that R5, R6 and R7 make one connection between B+ and ground to help bleed off, and I know the circuit I built is below 1V in probably about 10 to 15 seconds after I kill the power, however I don't assume that every last bit of juice has been dissapated out of C5 and C6 through the 10M45/LD1085. I am going to put the resistor load on it tonight and then try the DN2540 after I take some measurements to see how the two compare. 
 I hope 747 ohms(3 X 249ohm 1/2watt) is a pretty good estimate of actual working conditions. I think it will be close enough for testing purposes._

 

Actually I went with something totally different, this was taken from the 9-pin Aikido user guide.


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## Coreyk78

I just ran a PSUD2 simulation with the Hammond 159T choke, 2.5H 300mA 43 Ohm DCR, in place of the itty bitty one I have. The ripple was greatly improved and voltage dropped to ~165.


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## digger945

Yea I just had a look at that same schematic on the tubecad website. I'll do some poking around for chokes when I'm shopping for parts and see if I can find what your looking for, at an affordable price.
 I've read JB say many times that any choke is better than none, and is always an improvement.


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## Coreyk78

and just because I wanted to post a picture, heres the PS, ignore the messy wiring, I had everything temped together last night to test it.





 Also, I noticed that my heater supply was not elevated or whatever above ground like it was with the PS-1. The H-PS-1 has a ref pad between the H+ and H- outputs, now I need to figure out what to reference that too...


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## digger945

Is that a gold anodized Par-metal case? I have two of those for the Dynamite. I think it looks great, much neater than mine. Really like those 2 big Panasonics.

 Looks like there is a trace between the Ref and H- on the pcb.


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## Coreyk78

Yeah, its one of the gold Par-metal cases, I actually had ordered the clear anodize over the phone, but it came gold and I thought it looked cool so I decided to roll with it.

 And the reason I'm worried about the heater supply thing, is I'm thinking that if it isn't raised above ground that I'm probably exceeding the heater to plate voltage difference or whatever, so that could have maybe been causing some of the weirdness I heard last night.


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## digger945

Well the heaters are on a seperate circuit on the pcb from PS, but maybe the two are touching somewhere on the pcb. 
 I wanted to ask how you have your attenuator wired, and to what do you connect the ground?


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## Coreyk78

The pot is one of the other things I may have an issue with, I have 6 pairs of rca inputs and I'm using a 2 pole 6 pos grayhill switch to select inputs, and all the rca grounds are tied together but seperated for left and right, then connected to the input grounds on the Aikido PCB. 

 The left and right channel outs of the grayhill switch are connected to the pot and then to the inputs on the PCB. I didn't know what to do with the pot grounds though, so I wired them together to chassis ground, which may be wrong, idk. I'll probably try bypassing the selector and pot as an experiment.


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## digger945

I remember trying to just wire the negative input from the 0404 directly to my cans and just use the positive through the amp, sounded awful so I hooked the input ground back up to the amp pcb. The 0404 has an attenuator built in and I use that for volume. You may have a problem here if the input ground isn't making it all the way to the pcb or something, maybe.


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## Coreyk78

well the grounds are connected straight from the rca sockets to the pcb, so as long as the pot doesn't need to be grounded to the pcb then it should be ok


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## digger945

Yea that sounds ok, I don't think I would try grounding the pot to the pcb either.

 EDIT: Maybe as a last resort it wouldn't hurt to try grounding the pot to the pcb Corey, just to see if it helps any.
 Still don't know what might me giving you problems on only one channel though.


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## Coreyk78

Well, I still had some hum and distortion in both channels, just the left had much, much less hum.


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## digger945

Progress. Did you bypass something or cut and rewire?


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## Coreyk78

I bypassed the pot, no change, so that wasn't the problem.

 One thing I was able to try though, since the UPS guy got here. I'm gathering parts for a Tubelab.com Simple SE amp right now, and my choke came in today. A rather large Hammond 193L with 5H @ 300mA. I removed the tiny choke and temped the big one in, hum is gone in both channels, but it still has a prominent background hiss, and there is a lot of crackling in right channel. I'm gonna check some more stuff out. I think I may have a cold joint at the right input.


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## digger945

Ah yes, I had the exact same problem on a millet Hybrid once. Reflowed some ground joints and it cleared right up.


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## Coreyk78

reflowed a few joints and tried swapping out the right channel tubes and it cleaned up quite a bit, I'm still getting some bass distortion on the right channel, not sure why. Maybe fixing the heater bias could change that if the tubes are running outside there parameters right now.

 edit- actually I'd say there is almost equal bass distortion on both channels.

 another edit- I'm wondering about how I have the heater supply wired. The transformer I got is 12.6vct but I just connected the outside taps and left the center tap disconnected since my H-PS-1 was already built for a non CT transformer. I could remove a couple diodes and ceramic caps and connect the transformer CT in a full wave CT config. Don't know if that would make any possible difference. 
 I've tried pulling up some threads over on diyaudio.com about how to float the heater supply and they are talking about somehow referencing the center tap of the heater transformer to B+ with a voltage divider to float the heater supply. However, I have no idea what that means or how to go about doing it.


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## looser101

Glad to see progress is being made.

 Look here for a psu schematic. My choke was that big silver thing on the left, in the pic.


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## Coreyk78

Quote:


  Originally Posted by *looser101* /img/forum/go_quote.gif 
_Glad to see progress is being made.

 Look here for a psu schematic. My choke was that big silver thing on the left, in the pic._

 

I'm assuming that psu schematic is what you used for your original supply. I just ordered the exact same choke or at least the one that matches the specs in the schematic. What value did you use for R? I suppose that might vary somewhat depending on current draw, but I'm having trouble modeling it in PSUD2 and I don't want to have to order a whole stock of 10W resistors, hehe 
	

	
	
		
		

		
			





 Also how was your heater supply set up? Did you float it above ground?

 I'm not going to try and work on it more tonight however, since I'm now on beer 3 and losing concentration...


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## looser101

Quote:


  Originally Posted by *Coreyk78* /img/forum/go_quote.gif 
_I'm assuming that psu schematic is what you used for your original supply. I just ordered the exact same choke or at least the one that matches the specs in the schematic. What value did you use for R? I suppose that might vary somewhat depending on current draw, but I'm having trouble modeling it in PSUD2 and I don't want to have to order a whole stock of 10W resistors, hehe 
	

	
	
		
		

		
		
	


	




 Also how was your heater supply set up? Did you float it above ground?

 I'm not going to try and work on it more tonight however, since I'm now on beer 3 and losing concentration..._

 

10ohms 10W worked well in my setup. Maybe you can get 2 or 3 and add or subtract depending on what you need.

 I never elevated my original heater circuit. I just connected a .1uF cap from H+ to ground. If you want to elevate it, the circuit is in the manual. 






 Add the two resistors and the cap to the output of your B+ psu, then run a wire to the ref connection the H-PS-1.


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## dBel84

in case any of you have not yet seen the "ALL in One" - not a headphone amp but pretty sweet ..dB


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## Coreyk78

Quote:


  Originally Posted by *dBel84* /img/forum/go_quote.gif 
_in case any of you have not yet seen the "ALL in One" - not a headphone amp but pretty sweet ..dB_

 

oh man, that's really cool, I can hear my wallet crying...


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## BoilermakerFan

It seems pretty cool. All it needs now is Diamond Buffers and a headphone jack and it will look a lot like a MHM... 
	

	
	
		
		

		
		
	


	




 I'm still catching up on his blog posts since Dec. 2008 to present. That ortho thread moves faster than I can keep up now too!


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## Coreyk78

well, it seems strange, but I'm very happy. I seperated the PSU and Aikido grounds, and reinstalled the resistors for the solid state output section, and it all works! The B+ voltage dropped to 168v with the solid state section connected also, which is where I had expected it to be.

 I think I cooked my potentiometer with all the resoldering though, because I have a buzz and a channel imbalance in the left channel that wasn't there with the pot bypassed, so I need a new one of those, and I'm still waiting for the choke I ordered for the Aikido to come, the one for my Simple SE is too big to even be able to mount it inside the case anywhere, hehe. Sound on the not-buzzy right channel is just awesome though, I'm excited about this project again now! It isn't just an expensive pile of fail anymore


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## looser101

Great. Good to hear.


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## digger945

Good news.
 I can't wait 'till you get it fixed, if it's like mine it's really fun to listen to your music.
 Maybe you can rob a pot off something to get it patched up and be listening while your waiting for parts.
 I think you will be pleasantly surprised and satisfied with the SQ.


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## Coreyk78

Well I kept messing with it for a while last night, I have a pot on order, so I bypassed the one I have now and used my Zero Dac's preamp section for volume control. I have a persistent hum that stay at a constant level regardless of volume setting from the Zero, or whether there is a source connected or not. Music plays over the top of it and I can drown it out, but it's still there in the background and between tracks. I'll need to finish diagnosing that once I get the new pot and I know that part of the chain is OK. I think the hum must be power supply related, hopefully once I get the proper choke and the RC filter added it will help.

 Also right now listening to headphones straight off the solid state HP output the hum is the same, but I get a nasty shutoff pop, any way to cure that? 

 Also I was playing around with my Grayhill selector switch and there seems to be some sound "bleeding" through on the other 5 positions if I have only 1 source connected, althought the bleeding sound is very quiet I'm wondering if this is normal?


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## looser101

Some power grounding info here.

 Suggested signal path connection diagrams in the Beta22 wiring and ground section is a good start.

 Bleeding signal - are your signal wires twisted? Can you post a picture that includes everything (grounds, signal, etc)?


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## Coreyk78

I had already built up a ground loop breaker like the one on your first link last night, but I only had the power supply ground connected to that, since I currently have the Aikido pcb grounded through the center mounting hole with the gnd jumper on the board.

 My signal wires are all twisted pairs for L and R + from the RCA jacks to the selector switch, bundled together with zip ties. The out wires from the switch are the only ones not twisted because I just temped it to the inputs on the aikido board. I'm wondering if the selector switch needs to be isolated from the chassis somehow, I'm going to check it to see if the body of the switch is conductive.

 I do notice that the hum changes a lot when I touch them, and thats just touching the insulation, not the bare wire. I'm a little concerned that maybe the input wiring is too close to the mosfet heatsinks, I can post a picture when I get home to show what I mean. 

 The RCA grounds are tied together with a seperate 18ga solid copper wire running through the ground tabs, all the left jacks on one, right on the other, with a single wire from each of those solid copper wires to L and R input gnd.

 I'm still a bit suspicous of my heater supply, since I don't have anything connected to the ref pad yet, I don't know if the heaters could induce hum or not.


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## Coreyk78

Oh and one other thing about my PS, I ordered the parts before I saw the other schematic on your site Renato, so I didn't have any part values for a high voltage supply so i took the values from Broskies schematic in the 24V Aikido manual that suggested 1000uF caps on either side of the choke. Would my caps being 10x larger have any negative effects?


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## digger945

I was looking at your pic Corey and I wonder if those two transformers being so close to one another could have something to do with the hum.
 Are you still getting a hum with the source disconnected?
 Are your input RCA's and HP jack isolated from the chassis?
 I don't think the PS caps would make a difference, I have seen some of JB's schematics very similar to yours that have 2200uF caps in the same positions.


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## Coreyk78

I was wondering a little about the transformers, but I was trying to keep them as far as possible from the board, I may try turning the filament transformer 180* to see if it changes anything. I've also read of connecting the CT to ground if its not being used?

 The hum is still there without a source.
 All RCA's are isolated from the chassis, the HP jack I believe is not though, that's one thing I was going to look at today when I get home.


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## digger945

I don't think I would connect the CT to ground. Maybe you could take the transformer loose from the chassis and move it around some and see if it effects anything. I did this one time witha CKK amp and it made a huge difference. This would at least let you know that it is or isn't one or the other transformers. 
 My thinking originally was that maybe one transformer might be interfering with the other, magnetically speaking. They do look to be pretty close.


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## Coreyk78

Yeah the plastic bobbin on the filament transformer is only a few mm from the toroid. The toroid is a medical grade one though, so it has a screen ground tap that I connected to the chassis star gnd so hopefully that will work in my favor a bit. 

 I am wondering where I'm going to have room to mount the choke though. I was thinking I could cut away some of the perfboard and mount it right next to the PS near the front of the case. 
 Option 2 would be mounting it horizontally to the rear panel above the transformers since I have a 5" tall case, don't know if that would add to a magnetic interference problem If I do have one, but I experimented placing the big choke I'm using directly on top of the other 2 and didn't hear any change in the hum.

 Maybe I should order one of those internal divider panels from par-metal to use as an EMI shield between the PS section and the board, or just make my own panel from some flat sheet from the hardware store.


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## Coreyk78

Every time it feels like I'm close to making this thing work some problems just keep coming up.

 I added a 10R resistor between the rectifiers and the first C and a hammond 2.5H choke between the first and second C to the PS and added the heater gnd reference circuit. The choke cut hum dramatically but The 10R resistor had absolutely no effect on B+ voltage. 

 I replaced the volume pot with an alps blue 100k and that seems to be working fine. Hum is fairly minimal, if I move the wires from the pot to the inputs on the pcb around a little bit the hum changes from barely audible to unbearable. I have some different grounding ideas yet to try and see if I can eliminate it. 

 My main concern though is that the headphone output seems to be "clipping" badly. I don't know what other term would be appropriate to describe it. The sound cuts abruptly and I get a very nasty pop with a little pause before it pops again unless I back off the volume. It happens quite a bit earlier on the volume knob with my 48 ohm JVC cans vs. the 300 ohm Sennheisers.

 It doesn't seem to happen on the line out, but I'm driving a LM3886 chipamp with fairly high gain so I can't turn it up very far before I start to go deaf anyway.

 The other big issue is a very nasty turn off thump. I switched the aikido off a couple of times with headphones on my ears and I thought it ruptured my eardrums, it was actually painful. It does the same thing to the line out on shutoff, the woofers on my speakers must be moving through their full travel at shutoff, and the speaker protection relays in my amp really freak out.

 I'm feeling rather frustrated again 
	

	
	
		
		

		
		
	


	




 Is there a possibility that since I'm using 10M45S for the solid state buffers that I'm running into the 50mA current limit once again on the headphone output? Or is it possible that the 180 ohm cathode resistors are running my tubes too "hot" and they are running out of breath?


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## Coreyk78

well I redid my signal wiring in a more permanent fashion so it wasn't just hacked in there and my hum is all but gone, I can only here some PS noise at full volume. I still have the clipping on the HP output and the turn off popping issue to deal with though.


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## digger945

That may be all you can do with the transformer in the same case Corey. 
 Good to hear from you and to see your making progress. Have you any listening impressions for us yet?


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## Coreyk78

So far I'm very impressed with the sound, I thought my old beresford design TC-754 preamp was pretty good, but I can honestly say the Aikido blows it away. The sound is very detailed, smooth and natural. I also just finished building a VSPS phono pre so I could take the old preamp out of my system completely, the VSPS and Aikido really seem to work well together, my vinyl never sounded so good. The gain is a little high when listening to CDs from my PS one and playing through my chipamp, I can't turn it up very far before its too loud for me. But it works nicely with the VSPS since that is set up for 40db gain. The gain will probably be a good thing when I'm finished building my SimpleSE tube speaker amp.

 I figure the HP out clipping isn't a big deal, because regardless of which impedance cans I use the clipping only happens at ear-bleeding levels anyway, hehe.

 I'm pretty happy for now, I'll either have to always remember to turn off my amps and unplug my cans before I shut off the Aikido unless I can find a soft start circuit that can handle 170 volts.

 Much thanks for so much help from the people in this thread, especially digger945, looser101, and boilermakerfan.


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## digger945

I'm happy to see you finally enjoying it. I keep going back to mine whenever I need a fix. I listened to each half of my almost completed Dynamite and my first impression is that the Aikido has way more atmosphere to it. We'll see what happens when it's finally completed. After the meet this weekend I plan to begin the 6H30. I will see what I can find with regards to the turn-off pop and the clipping.


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## Coreyk78

I wanted to add that my best grounding results came when I ran the input grounds from the rca jacks to the pot, and then from the pot to the input gnd pads on the pcb. Also I ran the power supply ground to the Aikido PCB and installed the ground jumper on the PCB using the mounting hole and standoff as my star ground point.

 I'm going to try a redo of my power supply, I should be getting another choke today, along with some smaller 220uF caps and I'm going to try a CLCLC setup, with 220uF for C1 and C2, and 1000uF for C3.


----------



## looser101

Quote:


  Originally Posted by *Coreyk78* /img/forum/go_quote.gif 
_I wanted to add that my best grounding results came when I ran the input grounds from the rca jacks to the pot, and then from the pot to the input gnd pads on the pcb. Also I ran the power supply ground to the Aikido PCB and installed the ground jumper on the PCB using the mounting hole and standoff as my star ground point.

 I'm going to try a redo of my power supply, I should be getting another choke today, along with some smaller 220uF caps and I'm going to try a CLCLC setup, with 220uF for C1 and C2, and 1000uF for C3._

 

You might want to try the 0.1uF cap and 10ohm resistor in parallel where you put the ground jumper on the PCB. Did you twist the grounds and signal wire together? ie. One signal + one ground twisted together, repeat for each signal wire? If you move those wires around and the hum changes then you might want to get some small diameter coax. I've used RG-174 and it worked great.

 The all tube Aikido is probably the most docile pre/amp I've ever used for startup and shutdown. The music just fades in or out, no thump whatsoever.

 A tip for you if you don't have a scope....download a tone generator or individual tones of 60Hz and 120Hz. Play them and compare to the hum you hear. If 60Hz then it's probably AC pickup from the AC input or transformer. Or possibly a ground loop. If 120Hz then it's a PSU problem.

 Keep at it, it will all be worth it.


----------



## Coreyk78

I think the signal wires are pretty good, the hum at listening level is gone now, I can hear a very faint background hiss if I put my ear close to the speaker. The only time I hear significant noise now is when the volume is maxed without anything playing. But at that level the speakers would probably be distorting and smoking anyway, hehe. 

 I'm kind of thinking now that I should have just used a standard 9-pin board and used OPTs for headphones, would probably have been simpler. I still don't have bleeder resistors on the power supply caps, I wonder if that could be giving me the pop? I have some 300k 2W resistors I could use, I'd just need to install them from + at the cap to the ground rail right?

 I'm also going to change the rectifier diodes from 1N4007 to MUR860. I made that change on the power supply for my VSPS phono-pre and it made a huge difference, my phono stage is very quiet and hum-free.


----------



## BoilermakerFan

Quote:


  Originally Posted by *Coreyk78* /img/forum/go_quote.gif 
_
 I'm pretty happy for now, I'll either have to always remember to turn off my amps and unplug my cans before I shut off the Aikido unless I can find a soft start circuit that can handle 170 volts.

 Much thanks for so much help from the people in this thread, especially digger945, looser101, and boilermakerfan._

 

Been out of touch of late. Laid off for a month now and just been busy working on my shop area. Tied in the lights today to the main basement lighting circuit. Nice to have 12,000 Lumens of light in a 42 sq. ft. area. 

 The soft start circuit can be adapted from Ti's design like Colin did, or better yet, use the MHM schematic and just hit cetoole with a PM before you do... I'm pretty sure the coil on the Omron relay is 24VDC, but it should be able to switch higher voltage. You might have to use a similar, but higher rated relay. I know they make 240VAC relays. I have a big ass solid state relay with 24VD inputs, but it's huge and probably cost $$$. It's big enough to switch on full size refrigerators. I'll do a little homework on Peter Daniels thread on diyAudio. I know he really likes a certain line of Panasonic relays and they are about $6 each. Planned to upgrade my Darwin, but then decided the stock relays were fine for the console and now I won't need another Darwin for my other MAX build since the V1.2 is being built with dual inputs stock. I can add a DPDT to bring in a third and keep it simple. 

 Here's pics of the "shop" area. Receptacles will be live tonight and I'm finalizing my workbench design this week so I can pick up wood and get the carcass built up. Finish cabinetry and storage will be added later, but there will be a lot of it built in. Can't decide on walnut trimmed maple or maple trimmed cherry for the finish. I'm building one bench and I'm building it right the first time. Damn casters I want are $65 for four. 
	

	
	
		
		

		
			






http://s142.photobucket.com/albums/r...t=IMG_2183.jpg

http://s142.photobucket.com/albums/r...t=IMG_2185.jpg

http://s142.photobucket.com/albums/r...t=IMG_2188.jpg


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## Coreyk78

Nice work so far, I really like all the outlets and lights. My workspace is too dark and I'm always trying to figure out what I can unplug so I can plug something else in, hehe.


----------



## BoilermakerFan

Thanks. The receptacles are all on a shared circuit with others in the finished area of the basement on a single 20A breaker, but I don't really have anything too big that needs to be plugged in at the workbench. Mainly need quantities of outlets for the 'scope, soldering station, tube tester, battery chargers, etc. The center single outlet can be easily rewired into a dedicated 20A receptacle if I need too, but it is intended to be reserved for powering whatever piece I'm testing after building. The single 20A Twist-Lock plug at the back by the panel is a dedicated receptacle so if I need big power, then I'll just go 240VAC. Lighting is all florescent so the grand total is 167 watts, but the one shop light has a pull string to take 64 watts off line when I don't need all the light. Was just down there working on the receptacle junction box and the light is nice and bright. Still need to figure out where I want to put the Ethernet, phone, cable box, but I already have a matching box and conduit ready and painted for it. 

 I thought this project to get the shop area done would be drudgery, but it's actually become quite fun and I keep thinking of more ideas to improve the use of space so it keeps me motivated to think it through and get it done. I'll have to start a separate thread in the off topic area once I get further along or nearly finished. I've taken lots of pics, but don't want to keep dragging other threads off topic.


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## digger945

Oh yea, looks great. Seems like I never can have enough light. I will be taking notes to help improve my little work area.
	

	
	
		
		

		
		
	


	



 Like to see you at the meet in Indy this Saturday but I know it's a long drive and all.


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## BoilermakerFan

Thanks. 

 It's a long drive and the start of Spring Break for my daughter so we're heading to Cincy to visit family. Plus, while I have lots of gear in the pipeline, nothing is built and only my K601s and YH-3s are functional at the moment. Been using my vintage Yamaha receiver as my amp and it's a beast. YH-3s are going under to be modded shortly too. 

 A set of used ESW9s will be on their way to me shortly. I think I'm going to need to build a freestanding headphone cabinet now. Managed to build a collection with really realizing it. LOL! Have an idea for the design already and I'll be reusing some salvaged vintage privacy glass from a neighbor's old bathroom window from the late '30's. Might incorporate a spot for the Aikido, Yamaha receiver, and an Oppo CDP for a nice little office listening station.

 I can't remember if I posted earlier, but my buddy has a piece of figured walnut for my front panel of my Aikido amp. Since the walnut is dark, all knobs, feet, and trim will be maple. Just waiting on John to send me the font that he uses for the manual so my text labeling will look Asian and match his manual.


----------



## Coreyk78

I think I may have some minor mental illness...
	

	
	
		
		

		
		
	


	




 Apparently I must have had some tax return cash that really needed to be spent, because I happened to find 8 6GM8 tubes for a reasonable price and I bought them. And since my high voltage build is still being cranky, and since I just so happen to own a second 24v Aikido PCB and an appropriate power transformer I've decided to build up a 24v version and put that in my case. I've not given up on the high voltage one, but it would at least be a moral victory for me if I have a fully working Aikido with a fully proven configuration that I can actually listen to. Resistors and caps are already on order as well. 

 I've had some strange things happen to my Aikido since I put it into my system this week. For some reason the HP out has gone from a beatiful clean sound to a crappy distorted one while the line out still sounds perfect.

 Also yesterday I had a couple of random pops in the sound from the line out that were bad enough to trip the protection relays in my speaker amp. The weirdest thing easily has to be that I can reproduce that same pop when I turn on my TV, which is on the other side of the room on a different outlet. All this has been very troubling to me and made me nervous that I'm either going to blow up my Wharfedales or my HD580s and I've been afraid to even turn on my Aikido since the TV thing happened last night. 

 I don't know if I have DC on my output or how to actually test for it, I didn't leave any caps off the board so I would think DC would be blocked, I don't know what the heck is going on. Oh well, I'm going to keep working on the high voltage version while I enjoy the easy paint by numbers 24v one, hehe


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## digger945

Quote:


  Originally Posted by *Coreyk78* /img/forum/go_quote.gif 
_I think I may have some minor mental illness...
	

	
	
		
		

		
		
	


	


_

 

Oh good, I thought I was the only one who who had that illness
	

	
	
		
		

		
		
	


	




LOL!!!


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## Coreyk78

Quick question, my mouser order came in so I'm going to stuff my board for the 24v build tonight. I ordered 1000uF and 3300uF nichicon KW caps for C4 which is the headphone out cap. I ordered 2 sizes in case the 3300uf ones didn't fit between the heatsinks but they do. Any reason not to go ahead and use the big boys? Sonic benefits with the smaller caps at all? Just thought I'd ask since I have both.


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## looser101

I would use 1000uF. Larger will just increase turn off thump.


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## digger945

I've tried many different(but not all) caps Corey. Anything over 1000uF has no sonic benefit I can hear. Only one cap makes a real enough difference to immediately notice, and that's the Blackgate N, and mine are 25V 1000uF. I just got some Cornell Dub 470uF MKTG's on ebay and I really want to try them out soon.


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## Coreyk78

gotcha, I'll use the 1000uF then. I found some 680uF blackgate NX which I'm a little tempted to try, but 13 bucks each is still a lot for an electrolytic cap.


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## digger945

Where? I say go for it. I'm gonna get some more, not many but at least one more pair before they are all gone. They are my favorite in the 24V Aikido.


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## Coreyk78

secret... (wherever it is, it wasn't a place where they Craft things in a Sonic fashion)

 yeah I just sent them an email a little bit ago and I don't want them to sell out before I get a pair, hehe.


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## digger945

Tell ya what, if you don't like them after listening for a while, I'll buy them for what it cost you. Howz that.
 I don't think that will start a holy cap war.


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## BoilermakerFan

Well, ESW9's and modded T50rp's might have found their way into my collection and I'm making progress on the workshop, so I really need to start soldering! Still waiting for the new V1.2 MHM boards for the other two amps, but I can get the Aikido going for now. Finally getting warm enough to do some metal work on the chassis in the garage too. Hope to have the Aikido online in the next 3 weeks. Will also have an Oppo 980H as my source shortly too. Plan to open it up as soon as I get it to see what's inside and what can be upgraded.


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## Beefy

Quote:


  Originally Posted by *Coreyk78* /img/forum/go_quote.gif 
_gotcha, I'll use the 1000uF then. I found some 680uF blackgate NX which I'm a little tempted to try, but 13 bucks each is still a lot for an electrolytic cap._

 

That is the same boutique cap often recommended for the outputs on the Millett Hybrids. I don't know much about the Aikido, but I don't see why it would be a _bad_ choice......


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## manaox2

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_That is the same boutique cap often recommended for the outputs on the Millett Hybrids. I don't know much about the Aikido, but I don't see why it would be a bad choice......_

 

I choose not to include them now due to the reports that the blackgates do not play as well with bypassing. I need more time on my Aikido still, got one board and the power supply populated.


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## Beefy

Quote:


  Originally Posted by *manaox2* /img/forum/go_quote.gif 
_I choose not to include them now due to the reports that the blackgates do not play as well with bypassing. I need more time on my Aikido still, got one board and the power supply populated._

 

Again, I see no reason why the standard Millett recommendation of VitQ PIO wouldn't be OK.

 But then again, I only started reading about the Aikido today......


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## manaox2

Quote:


  Originally Posted by *Beefy* /img/forum/go_quote.gif 
_Again, I see no reason why the standard Millett recommendation of VitQ PIO wouldn't be OK.

 But then again, I only started reading about the Aikido today...... 
	

	
	
		
		

		
		
	


	


_

 

I haven't heard anyone recommending bypassing blackgates who have tried it. I have plenty of Vit Q. Right now I am planning using Muse ES 1000uf with RTI 1.0 and Multicap 0.15 bypasses. I hope that works well. I also have some Elna Silmic II I could substitute as well.


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## tomb

Quote:


  Originally Posted by *manaox2* /img/forum/go_quote.gif 
_I haven't heard anyone recommending bypassing blackgates who have tried it. I have plenty of Vit Q. Right now I am planning using Muse ES 1000uf with RTI 1.0 and Multicap 0.15 bypasses. I hope that works well. I also have some Elna Silmic II I could substitute as well._

 

Black Gates can definitely be bypassed. The VitQ's that beefy mentioned is one that seems to work well. However, many common bypass caps - such as the Wima MKP's - are too slow to have any effect on the BG's, or at least any _good_ effect. This is one reason the "safest" recommendation is often to suggest no bypassing at all for BG's.

 Vishay-Roedersteins (MKP's) maybe one box cap that's fast enough to bypass a Black Gate NX. The guys at Soniccraft recommend Multicap RTX's (polystyrene) as the bypass cap of choice for a Black Gate. It's just that those run large and may not accomodate some designs.

 Again, bypassing is more art than scientific. Some combos work, some don't - there's not much consistency. Unless you have suggestions that someone has actually tried, don't expect immediate success.
	

	
	
		
		

		
		
	


	





 P.S. I noticed that John Broskie is selling the Russian K42's on his site. We have a lot of experience with the K42's over on the MAX side of the house.
	

	
	
		
		

		
		
	


	




 They are definitely too slow to have any usefulness in bypassing Black Gates. I would recommend them these days only if you need a lot of warmth and strong bass. There are better choices for good mids and sparkling highs (the VitQ's run circles around them).


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## BoilermakerFan

Nice to see Beefy and Tom over here. 
	

	
	
		
		

		
		
	


	




 The Aikido 24V board has the room for the RTXs if you wish and can even be setup with a selector switch to allow the use of cap "A" only, cap "B" only, or both caps "A" + "B". It's a nice feature in that you can perform listening tests between two caps, or in my goal when using the Aikido as a preamp too, use the smaller cap only to act as a bass filter for listening to Fonken speakers at night when the wife and kids are in bed, but greater range of motion is required to prevent headphone use...


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## digger945

I've tried bypassing the NX with several different caps including Auricaps and to me they just sound better alone. I really need to get some of the VitQ's to try out sometime.
 This is just for the Aikido only, not the MH.


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## kintsaki

Quote:


  Originally Posted by *BoilermakerFan* /img/forum/go_quote.gif 
_Well, ESW9's and modded T50rp's might have found their way into my collection and I'm making progress on the workshop, so I really need to start soldering! Still waiting for the new V1.2 MHM boards for the other two amps, but I can get the Aikido going for now. Finally getting warm enough to do some metal work on the chassis in the garage too. Hope to have the Aikido online in the next 3 weeks. Will also have an Oppo 980H as my source shortly too. Plan to open it up as soon as I get it to see what's inside and what can be upgraded. 
	

	
	
		
		

		
		
	


	


_

 

sent you email a few days ago, have you received it?


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## BoilermakerFan

Quote:


  Originally Posted by *kintsaki* /img/forum/go_quote.gif 
_sent you email a few days ago, have you received it?_

 

Yes Mike, I did receive it and read it. Just haven't had the time to give you the fair reply that it deserves.


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## Coreyk78

Well I've been enjoying my Aikido for a few days now, it really turned out well I think. 

 I wanted to wait before I posted again to make sure everything was working right, hehe. Its dead silent with absolutely zero hum which makes me happy, also no turn on/off popping stuff going on either. 

 I made some changes from how I first put it together, I had originally used some LD1085s for the output buffers but something just didn't seem right with them, my HD580s sounded "ok" but my other low impedance cans sounded really awful. I picked up some LM317s and used those instead and it totally changed the way it sounds, so so much better, now all my cans sound great with this amp. 

 I also was using some k42y-2 1uf caps at c12 and c13, I just so happened to stop by my local surplus store today and found a box of Wima MKP10 1uf 160v caps for $0.19 each so I grabbed all that they had and put those in c12 and c13 and noticed more improvement, everything sounds "faster" somehow. I can't wait until my Blackgates get here to see if I can get even more improvement, they should be here this week 
	

	
	
		
		

		
		
	


	




 For tubes I'm using an NOS quad of GE branded 6GM8's which I believe are rebranded amperex, seem to be pretty nice. I'm waiting on a quad of NOS Siemens tubes to come from England so I can try rolling those in too.

 I also found some other interesting tubes at the surplus store today since I noticed they had a fresh box out on the shelf, found 2 nice 12BH7A, a Realistic 12BH7A GT with goldish looking pins, an RCA 6CG7 and an ECL84. Not bad for 2 bucks each.


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## digger945

Hard to believe a 24V hybrid with voltage regulators as output devices can sound so good, and capacitor coupled no less. Wait 'till you listen to the BG's, I left the leads long on mine so I could swop them out easily and try other stuff. What are you using for a source? What did you use for C11?


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## BoilermakerFan

Quote:


  Originally Posted by *Coreyk78* /img/forum/go_quote.gif 
_<snip>, I just so happened to stop by my local surplus store today and found a box of Wima MKP10 1uf 160v caps for $0.19 each so I grabbed all that they had <snip>

 <snip>I also found some other interesting tubes at the surplus store today since I noticed they had a fresh box out on the shelf, found 2 nice 12BH7A, a Realistic 12BH7A GT with goldish looking pins, an RCA 6CG7 and an ECL84. Not bad for 2 bucks each._

 

Damn, I wish I had a local surplus store like that! Nice finds!

 Glad to hear you're enjoying the amp too! Any thoughts on putting MOSFETs in for the buffers after 10M45S? The IRF510 and IRF610 should work as well as the NPN FET from the standard MOSFET-MAX BOM...


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## Coreyk78

Quote:


  Originally Posted by *digger945* /img/forum/go_quote.gif 
_Hard to believe a 24V hybrid with voltage regulators as output devices can sound so good, and capacitor coupled no less. Wait 'till you listen to the BG's, I left the leads long on mine so I could swop them out easily and try other stuff. What are you using for a source? What did you use for C11?_

 

The source is my modded Zero DAC with an Audio-GD OPA-Earth as the opamp in the DAC section.

 I used a 1KuF 35v Nichicon PW for C11.

 I'm also using a seperate heater power supply since I have 2 H-PS-1s and one was already built for 12.6v output, B+ is 25.2v


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## Coreyk78

I got the Blackgates yesterday and put them in today.

 I had .47uF Multicap PPFX in the bypass position but I pulled them for now to be able to hear the BGs by themself and they sound really nice so far, really clean. I may leave them unbypassed I don't know yet.


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## BoilermakerFan

Quote:


  Originally Posted by *Coreyk78* /img/forum/go_quote.gif 
_I got the Blackgates yesterday and put them in today.

 I had .47uF Multicap PPFX in the bypass position but I pulled them for now to be able to hear the BGs by themself and they sound really nice so far, really clean. I may leave them unbypassed I don't know yet._

 

Let them burn in for at least 100 hours before you make that decision. Every single comment I've read is that the BGs definitely do improve with burn in. Most just argue how much improvement.


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## dBel84

I am sure TCJ fans already know about this but for those who don't ...... a new all in one headphone / linestage amp from JB which runs at a higher B+ ..dB


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## manaox2

Quote:


  Originally Posted by *dBel84* /img/forum/go_quote.gif 
_I am sure TCJ fans already know about this but for those who don't ...... a new all in one headphone / linestage amp from JB which runs at a higher B+ ..dB_

 

Yeah, been looking out for the magical day when all eleven boards (total) will go on sale. They'll be gone quickly.


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## BoilermakerFan

Quote:


  Originally Posted by *manaox2* /img/forum/go_quote.gif 
_Yeah, been looking out for the magical day when all eleven boards (total) will go on sale. They'll be gone quickly._

 

But manaox, you pre-ordered with JB via email, right? 
	

	
	
		
		

		
		
	


	






 I've been working on my chassis prep for my MAX and Aikido. I need to finish wire brush deburring all the holes, then test fit the boards. When I do, I'll take pics and post them up here...


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## manaox2

Quote:


  Originally Posted by *BoilermakerFan* /img/forum/go_quote.gif 
_But manaox, you pre-ordered with JB via email, right? 
	

	
	
		
		

		
		
	


	


_

 

Awww, no. 
	

	
	
		
		

		
		
	


	




 oh well, I may have to skip over this sadly for now.

  Quote:


  Originally Posted by *BoilermakerFan* /img/forum/go_quote.gif 
_I've been working on my chassis prep for my MAX and Aikido. I need to finish wire brush deburring all the holes, then test fit the boards. When I do, I'll take pics and post them up here..._

 

I'll be looking forward to it, I want to see what you do with the Nabu case.


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## BoilermakerFan

Quote:


  Originally Posted by *manaox2* /img/forum/go_quote.gif 
_I'll be looking forward to it, I want to see what you do with the Nabu case._

 

I'll take in progress pics later and pics when I test fit everything again to make sure it lines up. The Aikido isn't nearly as packed as the V1.0 BJT MAX.


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## rhester

For anybody who built the 24V version of the Aikdio with the 6GM8 tubes and H-PS-1 power supply, what transformer reccommendation do you have? All I need to finish and test this amp.


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## Coreyk78

Quote:


  Originally Posted by *rhester* /img/forum/go_quote.gif 
_For anybody who built the 24V version of the Aikdio with the 6GM8 tubes and H-PS-1 power supply, what transformer reccommendation do you have? All I need to finish and test this amp._

 

I ended up using 2 H-PS-1 supplies for mine, with 2 transformers. I just used a standard 12.6v EI core one for the heaters, I don't remember the brand right now. 

 My B+ transformer is overkill, I already had it on hand though so I used it, it's a 160va 2x24vac toroid, I paralleled the secondaries and I am running 25.2v for B+.

 If your going to run 1 supply I'm sure you will have good luck with a much smaller transformer, the H-PS-1 can only pass 2.5A max.


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## digger945

Quote:


  Originally Posted by *rhester* /img/forum/go_quote.gif 
_For anybody who built the 24V version of the Aikdio with the 6GM8 tubes and H-PS-1 power supply, what transformer reccommendation do you have? All I need to finish and test this amp._

 

On mine the same PS is used for B+ and heaters. It's a simple matter of choosing the appropriate jumpers. You could go either way, seperate supplies with 6, 12 or 24v for heaters and 24v for B+ or use a 24v supply for both at the same time.

 I think you will really enjoy this amp, and it's good to see another one will be built and listened to.


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