# Is anyone building the KGSSHV?



## verwandlung

I actually know that some people are, but does anyone know anyone who is or might be planning to sell it? 
   
  Thanks.
   
  Verwandlung
   
   
  PS. Please don't tell me that I can do it myself: I know I can't!


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## verwandlung

I am just not ready to believe this!


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## kevin gilmore

although there is a standard build that fits in a single pesante chassis, it seems
  that everyone building these are going for over the top custom chassis, and once
  you build one of those, you don't want to sell it. So eventually one might show
  up used, but you are going to wait a while to get it.


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## tranhieu

Oi, you can do it yourself, save time waiting for a used one turning up in the fs box.


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## sydneyaudio

Guys, how do we get the details on building one of these, schematics etc.? Really enjoying my O2 Mk1's, but have read that the 323s may not be enough amp...


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## kevin gilmore

schematics here
http://gilmore.chem.northwestern.edu/kgsshvproduction.pdf
http://gilmore.chem.northwestern.edu/kgsshvps8e.pdf
   
  on board heatsink version gerber files
http://gilmore.chem.northwestern.edu/kgsshvampv6.zip
   
  off board heatsink version gerber files, latest board
http://gilmore.chem.northwestern.edu/kgsshvampv7s.zip
   
  power supply
http://gilmore.chem.northwestern.edu/kgsshvps8e.zip


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## verwandlung

Quote: 





kevin gilmore said:


> schematics here
> http://gilmore.chem.northwestern.edu/kgsshvproduction.pdf
> http://gilmore.chem.northwestern.edu/kgsshvps8e.pdf
> 
> ...


 

 Thank you very much Mr. Gilmore. It is very kind of you to share this (but of little use for someone like me I am afraid). At any rate, it seems that I am going to order your other creation, the BHSE, since it is the only one Head Amp is building now. Still, I would much prefer a solid state amp (not having to worry about leaving it on for long periods of time). 
   
  If I may ask, how  does the KGSSHV compare with the BHSE in terms of sound?


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## kevin gilmore

The few others that have heard both would be better qualified to answer this.
   
  I'm clearly biased   (about 580 volts)


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## verwandlung

Quote: 





kevin gilmore said:


> The few others that have heard both would be better qualified to answer this.
> 
> I'm clearly biased   (about 580 volts)


 

 Somehow I thought you designed the BHSE as well...


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## kevin gilmore

I did design the BH, and justin made a few modifications and the result is the BHSE.
   
  I have at least 9 different kind of stax amps. And a few of them i have 2 of.


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## verwandlung

Quote: 





kevin gilmore said:


> I did design the BH, and justin made a few modifications and the result is the BHSE.
> 
> I have at least 9 different kind of stax amps. And a few of them i have 2 of.


 


  That it was I thought. So then I am not sure why you should be reluctant to say how you think the BH(SE) and the KGSSHV compare. It is not exactly as asking you whether you prefer one child over another, but rather asking what are the strengths and weaknesses (if any!) of one and the other. That being said, I can understand that you would prefer to avoid having to respond to such question. It is pity though since you are among the few who heard both.
   
  On another note, could you tell me how long it took after you designed the BH for Justin to build it? What would be a reasonable guess as to how long it may take before someone decides to commercially build the KGSSHV? It seems that the KGSS was one of the very best electrostatic solid state amp (to drive the Stax 007) and I assume that the HV version is even better... How long, really, can we live without either one of them being produced!? -- I am sure that the your BH(SE) is a masterpiece, but a very HOT one I was told, and with TUBES, which somehow I would like to avoid if I could.
   
  Thanks again.


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## Asr

Quote: 





verwandlung said:


> On another note, could you tell me how long it took after you designed the BH for Justin to build it? What would be a reasonable guess as to how long it may take before someone decides to commercially build the KGSSHV? It seems that the KGSS was one of the very best electrostatic solid state amp (to drive the Stax 007) and I assume that the HV version is even better... How long, really, can we live without either one of them being produced!? -- I am sure that the your BH(SE) is a masterpiece, but a very HOT one I was told, and with TUBES, which somehow I would like to avoid if I could.


 

 This isn't really intended to answer your question but hopefully it clarifies a few things for you:
   
  http://www.headamp.com/electrostat_amps/kgbh/index.htm
  http://www.headamp.com/electrostat_amps/bhse/index.htm
   
  The BHSE is sort of an evolution of the KGBH that Justin himself came up with.
   
  Also, you seem to not realize that commercial building of the KGSSHV would have to be approved by Dr. Gilmore. Or in other words, not just anyone will be able or allowed to commercially build KGSSHVs - and Dr. Gilmore is definitely a stickler on who can build his designs. 
	

	
	
		
		

		
		
	


	




 The KGSSHV is also primarily a DIY project; if you really wanted a KGSSHV it'd probably be more practical to commission a DIY-er as the probability of commercial production is a lot lower.
   
  Just because HeadAmp stopped producing KGSS amps doesn't mean they're not available anymore. They've been known to appear from time to time on the FS forums. There have also been other DIY-ers' KGSS amps as well, in addition to HeadAmp's.


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## kevin gilmore

I do want to prevent another trevornetwork fiasco.
  Which means no more plexiglass boxes held together with superglue.
   
  If justin does do the kgsshv it will be just as outrageous as the bhse.


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## verwandlung

Quote: 





asr said:


> This isn't really intended to answer your question but hopefully it clarifies a few things for you:
> 
> http://www.headamp.com/electrostat_amps/kgbh/index.htm
> http://www.headamp.com/electrostat_amps/bhse/index.htm
> ...


 


  Thanks for the clarifications. I was mostly aware of those things. That is why I, although indirectly, asked Mr. Gilmore whether he knew when (approximately) we can expect a commercial production of the KGSSHV. Justin (from Head Amp) told me that it was “possible” that he would build it, but didn't go father than that.
   
  The fact is that I am just deeply torn : if I knew that in a year or so there is a  good chance that I can get a KGSSHV (ideally from Head Amp), I think that I would not order the BHSE now and just wait a little longer. But if it was more likely that if a KGSSHV is ever build commercially, it wouldn't be before 2 to 3 years, then my decision would me easy, that is, I would go without further delay for the BHSE with no hesitation.


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## verwandlung

Quote: 





kevin gilmore said:


> .
> 
> If justin does do the kgsshv it will be just as outrageous as the bhse.


 


  Thank you. I guess that answer my previous question as to how both amps compare.


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## Asr

Quote: 





verwandlung said:


> The fact is that I am just deeply torn : if I knew that in a year or so there is a  good chance that I can get a KGSSHV (ideally from Head Amp), I think that I would not order the BHSE now and just wait a little longer. But if it was more likely that if a KGSSHV is ever build commercially, it wouldn't be before 2 to 3 years, then my decision would me easy, that is, I would go without further delay for the BHSE with no hesitation.


 

 Given Justin's track record, I wouldn't personally expect a HeadAmp KGSSHV for another 2 years at least, if not more. You'd almost definitely get a BHSE sooner if you ordered one soon. And given the high resale value typical of HeadAmp products (particularly the BHSE), you could probably re-sell the BHSE for very low loss, if any.
   
  Or another strategy - if you just want to wait for a KGSSHV and don't have much interest for a BHSE, you could probably acquire a lesser amp more easily, like one of the Stax 323S, 717, or 727 amps, or a used KGSS, or even an Exstata, if you really want to get as cheap a stop-gap as possible. I've personally heard the SR-007/Exstata combo and it wasn't bad - maybe not something I'd recommend long-term but for a stop-gap, why not.


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## Elysian

I believe KG is discussing build quality.  Justin does not skimp when it comes to quality, fit, and finish, and part of the BHSE cost is incorporated in the exacting job Justin does, and what a great job he's done with the chassis.
   
  Given the several years of stat amp threads I've read, I'd be highly surprised if a commercial KGSSHV emerged anytime before 2H2013 at earliest.  If you really want a KGSSHV that badly, you should commission one, or build one with a friend whose comfortable around high voltage electronics.  One person built two DIY T2s with an experienced friend.


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## verwandlung

Quote: 





asr said:


> Or another strategy - if you just want to wait for a KGSSHV and don't have much interest for a BHSE, you could probably acquire a lesser amp more easily, like one of the Stax 323S, 717, or 727 amps, or a used KGSS, or even an Exstata, if you really want to get as cheap a stop-gap as possible. I've personally heard the SR-007/Exstata combo and it wasn't bad - maybe not something I'd recommend long-term but for a stop-gap, why not.


 


  How does the Stax 323S compare with the 323II? Does it make much sense to go from one of those to the 727?


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## verwandlung

Quote: 





elysian said:


> Given the several years of stat amp threads I've read, I'd be highly surprised if a commercial KGSSHV emerged anytime before 2H2013 at earliest.  If you really want a KGSSHV that badly, you should commission one, or build one with a friend whose comfortable around high voltage electronics.  One person built two DIY T2s with an experienced friend.


 


  Thanks Elysian for your take on the estimated time. I guess I should relax a little bit and just go for something (Stax 727 or BHSE), which both I can easily resale when the KGSSHV comes out.


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## Elysian

Yes, I'd just get something now that drives the O2 reasonably well.  That's why I got the GES, even though my end-game stat amp is the BHSE.
   
  It might be good to start with a lesser amp since it'll help you appreciate the better stuff all the more   Even with all the BHSEs coming out, I doubt that resale value will suffer much, if at all, given how it is an end-game amp.
   
  I was also very worried about solid state vs tube reliability, replacement costs, safety, etc., but it's actually not nearly as big a deal as I had thought.  My setup has 20 tubes in it and I just use common sense when operating it.  Headamp also has a 3 year warranty, and Justin has been a stand-up guy in my interactions with him.  You don't want to get a KGSSHV and wonder what you're missing after you read 20+ pages of happy BHSE owners in audio nirvana.


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## verwandlung

Quote: 





elysian said:


> Yes, I'd just get something now that drives the O2 reasonably well.  That's why I got the GES, even though my end-game stat amp is the BHSE.
> 
> It might be good to start with a lesser amp since it'll help you appreciate the better stuff all the more  ...
> 
> ...  You don't want to get a KGSSHV and wonder what you're missing after you read 20+ pages of happy BHSE owners in audio nirvana.


 

 I am not sure that I want to start with a lesser amp (I am currently driving my 007 with a Stax 323II). As you may guess, I find this “shopping” time pretty annoying actually: somehow I just want to get something good (or even great, why not?), listen to music and forget about amps! I suppose that if I could get a KGSSHV now I would be quite satisfied with it and not think much of the 20+ pages of happy BHSE owners because I would just stop reading those pages, plus I would not have to worry about leaving the amp on all day long!  
   
  On the other hand, since there is not KGSSHV in sight, at least for a near future, I guess that I would already notice a great improvement if I were to switch form my Stax 323II to a 727II and perhaps I would even be very satisfied with it for at least a few years, wouldn't I? Aren't there any happy owners of 007/727 out there? -- I assume that the people at Stax think that there flagship amps remain after all suitable for their flagship earspeakers (even though they are certainly certainly aware that they might not be the absolute best).


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## visualguy

Quote: 





verwandlung said:


> On the other hand, since there is not KGSSHV in sight, at least for a near future, I guess that I would already notice a great improvement if I were to switch form my Stax 323II to a 727II and perhaps I would even be very satisfied with it for at least a few years, wouldn't I? Aren't there any happy owners of 007/727 out there?


 

 The SRM-727A (unmodded) doesn't drive the SR-007mk1 all that great. I would recommend either sticking to your 323, or trying to find a used KGSS if you want something better. A modded 727 may also be a good option - I don't have any experience with that one.


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## spritzer

Switching from a 323 to a 727 isn't as straight forward as the latter being more powerful and thus better since their voicing is completely different.  Now the modified 727 is a solid improvement over a 323 but only about 10 of those out there...


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## verwandlung

There is of course always the possibility of getting a new 727 and get it modified (by either one of the person you, Spritzer, and I don't remember who else, recommended). I am surprise though that there is not much difference between the 323 and the non-mofified 727. Hum, it seems that I always come to the same conclusion: just order that BHSE!
   
  Meanwhile, I hope to be lucky enough to find a used KGSS. By the way, what is a good price for a used KGSS? Someone here wanted to sell a five years old KGSS for $1850 (with only one volume control and no RCA and 450VW caps). Should I jump on it?


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## visualguy

Quote: 





verwandlung said:


> I am surprise though that there is not much difference between the 323 and the non-mofified 727.


 

  
  They actually sound very different. The 323 is better with the SR-007mk1 in my opinion, but the 727 is better with the SR-009.


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## verwandlung

Quote: 





visualguy said:


> They actually sound very different. The 323 is better with the SR-007mk1 in my opinion, but the 727 is better with the SR-009.


 


  I guess what you said about mk1 is also valid for the mk2 in that case, isn't?
   
  By the way, what is a good price for a used KGSS? Someone would sell me a five years old KGSS for $1850 or possibly less (with only one volume control though and no RCA and 450VW caps). Should I jump on it?


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## Elysian

For a five year KGSS, my gut tells me that that's on the slightly higher side for a KGSS, as used KGSS prices, over the last few years, have been around $1300-2100 or so.  You can use the search function to see previous KGSS FS posts over the last two years.  The past FS threads usually don't say how old the KGSS is, but they do mention the builder.
   
  If I was in the market for a KGSS, I'd probably be looking closer to $1550-1700.  I'd be looking for one Justin built, as Headamp products have a good reputation for build quality and longevity.


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## verwandlung

Quote: 





verwandlung said:


> I guess what you said about mk1 is also valid for the mk2 in that case, isn't?
> 
> By the way, what is a good price for a used KGSS? Someone would sell me a five years old KGSS for $1850 or possibly less (with only one volume control though and no RCA and 450VW caps). Should I jump on it?


 


  So it is actually quite expensive, considering that there is no RCA and only one volume control (which is not a problem per se, but should somehow lower the cost).


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## DaveBSC

Quote: 





verwandlung said:


> So it is actually quite expensive, considering that there is no RCA and only one volume control (which is not a problem per se, but should somehow lower the cost).


 
   
  The Headamp KGSS used dual volume controls in lieu of a balance control. In my view it's completely unnecessary, and annoying. Stepped attenuators track _extremely _well between the L/R channels, there's none of the nonsense that pots have of being off by several dB at the bottom of the volume range. Headphones don't have room interactions, so unless there's something wrong with your hearing, I don't see why you'd need a balance control, and having to make sure the two steppers are lined up every time you want to adjust the volume is just a PITA.
   
  The Stax split volume control/balance is a way better system, but I never use that either. My KGSSHV uses a single balanced attenuator, and incidentally also is XLR only. I don't think $1850 is all that bad. There's not a huge supply of the things, and it's not as if you can just go order one from Headamp instead.


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## n3rdling

The only time a channel balance on amps comes in handy is when you have a channel imbalance in the headphones which isn't totally uncommon with some electrostats.


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## visualguy

Quote: 





verwandlung said:


> I guess what you said about mk1 is also valid for the mk2 in that case, isn't?


 

 I don't know - I've never listened to the mk2.


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## verwandlung

Thank you all. I was not saying that I would miss having two volume controls or no RCA, simply that the price could be a little high, especially considering the absence of those features.
   
  One other thing I didn't mention because it is pretty common for this amp is that there is only one entry for the headphone, so no possibility to use two pairs of cans at the same time. Hence this question: would I be able to use my DAC with two different amps at the same time (one using the RCA, the other one the XLR) for the few times when I like to listen to music someone else? Or is it just a bad idea, or simply something which will not work?


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## justin w.

Quote: 





verwandlung said:


> Thank you. I guess that answer my previous question as to how both amps compare.


 


  i spent $4k a year ago to get the die made for the heatsink that will be used for this amp and others.  it's just sitting around!  wish i had the time, but orders for the BHSE need to be filled, and then I can make some progress on it.  it will be a single box amp because otherwise it would cost as much as the BHSE.  really the only difference in cost between building a BHSE and a KGSSHV is the cost of a quad of EL34 tubes and 2 more wires on the umbilical cable.


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## justin w.

Quote: 





davebsc said:


> The Headamp KGSS used dual volume controls in lieu of a balance control. In my view it's completely unnecessary, and annoying. Stepped attenuators track _extremely _well between the L/R channels, there's none of the nonsense that pots have of being off by several dB at the bottom of the volume range. Headphones don't have room interactions, so unless there's something wrong with your hearing, I don't see why you'd need a balance control, and having to make sure the two steppers are lined up every time you want to adjust the volume is just a PITA.
> 
> The Stax split volume control/balance is a way better system, but I never use that either. My KGSSHV uses a single balanced attenuator, and incidentally also is XLR only. I don't think $1850 is all that bad. There's not a huge supply of the things, and it's not as if you can just go order one from Headamp instead.


 

 The reason the KGSS used dual volume controls was because at the time I started building that amp (end of 2003), I'm not sure there were any dealers selling the quad stepped attenuators (required for a balanced amp)  and I didn't have the volume at that time to buy directly from DACT.  so, I used the parts available to me, which meant there would be dual volume controls.
   
  There were improvements to the build quality of the KGSS in the last couple years.  You're not going to see it just looking at the chassis, however.  The improvements are internal.


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## visualguy

Quote: 





justin w. said:


> it will be a single box amp because otherwise it would cost as much as the BHSE.  really the only difference in cost between building a BHSE and a KGSSHV is the cost of a quad of EL34 tubes and 2 more wires on the umbilical cable.


 

 Unless there's some noticeable effect on the sound (noise), single box is better in my opinion - more convenient and easier to place.
   
  I'll definitely sign up for it when you offer it! I've been enjoying the KGSS for over 4 years now.


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## DaveBSC

Quote: 





> Originally Posted by *verwandlung* /img/forum/go_quote.gif
> 
> One other thing I didn't mention because it is pretty common for this amp is that there is only one entry for the headphone, so no possibility to use two pairs of cans at the same time. Hence this question: would I be able to use my DAC with two different amps at the same time (one using the RCA, the other one the XLR) for the few times when I like to listen to music someone else? Or is it just a bad idea, or simply something which will not work?


 

 That shouldn't be a problem at all. As long as the single ended and balanced outputs of your DAC are active at the same time (most are) you can connect two amps to the same DAC and use them simultaneously.


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## DaveBSC

Quote: 





justin w. said:


> i spent $4k a year ago to get the die made for the heatsink that will be used for this amp and others.  it's just sitting around!  wish i had the time, but orders for the BHSE need to be filled, and then I can make some progress on it.  it will be a single box amp because otherwise it would cost as much as the BHSE.  really the only difference in cost between building a BHSE and a KGSSHV is the cost of a quad of EL34 tubes and 2 more wires on the umbilical cable.


 

 It will definitely make a lot of people happy if Headamp makes a HV. Single box can definitely be done, even with the 500V version. That's what mine is. It's a little tight inside, but it works. Interesting that there weren't quad SAs available back then, I had always just assumed that you wanted to offer a balance adjustment. While we're talking SAs, might I humbly suggest switching to Goldpoint? Noticeably better than DACT, IMHO.


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## visualguy

Quote: 





davebsc said:


> might I humbly suggest switching to Goldpoint? Noticeably better than DACT, IMHO.


 

 Goldpoint certainly has a better feel to it when you turn the knob. Have you found other advantages?


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## justin w.

Quote: 





justin w. said:


> i spent $4k a year ago to get the die made for the heatsink that will be used for this amp and others.  it's just sitting around!  wish i had the time, but orders for the BHSE need to be filled, and then I can make some progress on it.  it will be a single box amp because otherwise it would cost as much as the BHSE.  really the only difference in cost between building a BHSE and a KGSSHV is the cost of a quad of EL34 tubes and 2 more wires on the umbilical cable.


 


   


  Quote: 





davebsc said:


> It will definitely make a lot of people happy if Headamp makes a HV. Single box can definitely be done, even with the 500V version. That's what mine is. It's a little tight inside, but it works. Interesting that there weren't quad SAs available back then, I had always just assumed that you wanted to offer a balance adjustment. While we're talking SAs, might I humbly suggest switching to Goldpoint? Noticeably better than DACT, IMHO.


 

 the reason I use the DACT is for PCB mounting.  GoldPt never offered a PCB mount version (maybe they do now).  But overall I am tired of SAs, especially the 24 step ones, and want to move exclusively to high-end potentiometers.  I just don't want to go exclusively with the Alps RK50 on the BHSE and  possibly exclude someone from being able to afford it.


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## DaveBSC

Quote: 





visualguy said:


> Goldpoint certainly has a better feel to it when you turn the knob. Have you found other advantages?


 

 I've occasionally seen noise issues with DACTs when changing steps, never with Goldpoints. I haven't done any lengthy A/B comparisons of the two in terms of sound, but to the best of my knowledge I think the Goldpoints may sound a bit better.


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## DaveBSC

Quote: 





justin w. said:


> the reason I use the DACT is for PCB mounting.  GoldPt never offered a PCB mount version (maybe they do now).  But overall I am tired of SAs, especially the 24 step ones, and want to move exclusively to high-end potentiometers.  I just don't want to go exclusively with the Alps RK50 on the BHSE and  possibly exclude someone from being able to afford it.


 
   
  Which pots were you thinking? I've seen the TKD pots spoken of pretty highly, but have no experience with them. The standard Alps pots are pretty meh. I looked at several SAs for my HV build, and unfortunately most of the 40+ step ones are not available as quads. I settled on the 48-step Khozmo Z-foil, lot of money for a SA, but it should sound _really _good. The problem with Khozmo though is that it may take them two tries to actually get you the one you ordered.


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## spritzer

Quad pots FTW!!!  
	

	
	
		
		

		
		
	


	



  
  Quote: 





verwandlung said:


> There is of course always the possibility of getting a new 727 and get it modified (by either one of the person you, Spritzer, and I don't remember who else, recommended). I am surprise though that there is not much difference between the 323 and the non-mofified 727. Hum, it seems that I always come to the same conclusion: just order that BHSE!
> 
> Meanwhile, I hope to be lucky enough to find a used KGSS. By the way, what is a good price for a used KGSS? Someone here wanted to sell a five years old KGSS for $1850 (with only one volume control and no RCA and 450VW caps). Should I jump on it?


 

 Well I don't mod 727's (unless you find me in a really good mood) bur any experienced DIY'er can easily do the mod.  You only need 4 resistors (high quality metal film) and to adjust the amp afterwards. 
   
  Nothing wrong with the KGSS having 450WV caps.  It runs off a dual 280VAC transformer and runs on +/-350VDC rails so those caps are well within spec.


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## verwandlung

Quote: 





justin w. said:


> ... it will be a single box amp because otherwise it would cost as much as the BHSE.  really the only difference in cost between building a BHSE and a KGSSHV is the cost of a quad of EL34 tubes and 2 more wires on the umbilical cable.


 


  I am very glad to learn that this (KGSSHV) is in the pipeline. 
   
  Justin, do you think that you will make a batch 4 of BHSE after you are done with the next one (expected to be completed sometime mid 2012)? Is it too early to know?


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## verwandlung

Quote: 





spritzer said:


> Quad pots FTW!!!
> 
> 
> 
> ...


 
   
  Spritzer, I was referring to the two guys in NYC that you and someone else mentioned a while ago when I asked whether you knew people here who would do that job for me. But there is no need to come back on that topic since the 727 (modified or not) is becoming less and less of a option for me. It will be either the BHSE or most likely (with even more patience) the KGSSHV when Justin is ready!
  Thanks.


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## verwandlung

Quote: 





davebsc said:


> That shouldn't be a problem at all. As long as the single ended and balanced outputs of your DAC are active at the same time (most are) you can connect two amps to the same DAC and use them simultaneously.


 


  That is what I suspected. I am pretty sure they are (have a Bel Canto 2.5). 
  Thanks.


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## Hennyo

I am undergoing building KGSSHV, and I'm ******* proud of it.


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## n3rdling

Cool, what headphone do you plan to use with it?


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## Hennyo

Hi N3rdling
  I was inspired by Chinsetta's work (asked some of the people at the meet how they liked his first set of headphones once heard). 
	

	
	
		
		

		
		
	


	




 Needless to say the response was pretty much (really overwhelmingly) positive. I even went to the Thai sites to see what they 'heard' or how 'good' they thought they were.
   
  I'm making 4x pair of diy electrostats. Checked it out for the last month or so and all the materials are on the way.   Some are already here, Fortunately it's not very hard for me to get access to one of the University CNC machines for a bit.
   
  My plan is to do two drivers that are similar (as close as possible) to HE90 and Sr 007. ~
   
  One HE90 variant, One 007 clone, (or as close as I can get) and maybe a couple of my own designs. Or if they turn out well, I'd like to use Koss ESP 950. After that, I'll likely design my own, but those are my thoughts as of now...
   
  Plastic/wood may be the baffle/cup for the second pair, and the third pair may be all wood. I would like to:
  HE90-Plastic - Second HE90 - improve somehow upon the first HE90 to more truly try to match the originals sound.
  Sr007-Wood,
  Koss ESP 950- Plastic/wood hybrid
  A design or two of my own (maybe replacing and just buying the 950 so I have a genuine set...) - likely wood.
   
  EricJ's also been wonderful in helping me out with any uncertainties I'm having with the formula for the headphones (just the particulars). To credit everyone who answered a question or two would just be too much, thanks for being so responsive.
   
  Although busy... the goal is to have the headphones done by mid-January. And KGSSHV in a couple weekends (for me realistically) as soon as I have the funds... Depends on the next couple weeks. I'd like to start the stuffing (thanks for selling Tcp)! When Spring starts in three weeks... I guess the main problematic issue is a couple transistors and getting the trafo to my doorstep.
   
  Something I'd like to share, the special plugs for the HE90 variant of headphone. EricJ made a few of these back these a while back and wanted to share a picture with me. The other headphones will likely get Stax plugs or something similar to this. But in the spirit of diy, I'd like to make the diy "HE90" this one. I may also etch credit to those who's helped and answered questions onto my KGSSHV..
   

   
  Thanks for making this project quite straightforward KG! Livewire, Spritz, Douglas, and a host of others. From where I'm coming from, this is a great way to learn (even how to use solidworks/CNC. Diy CNC in the future?
   
  To Wahara - _Teh projects is epics._ Thanks for sharing your builds because that is truly some inspiring piece of kit. I'm almost apprehensive,.... You are my idol and have largely made electrostatics surmountable for a first year uni student like me.


----------



## verwandlung

Quote: 





hennyo said:


> I am undergoing building KGSSHV, and I'm ******* proud of it.


 


  Are you making some progress Hennyo? How many are you building?


----------



## chinsettawong

Hi Hennyo,
   
  Nice to see that you are moving ahead with your DIY ES headphones project.  Let us know how it goes.
   
  Wachara C.


----------



## Frur

...


----------



## HDMan

Power supply is finished.
   

   
  Still waiting for some IXYS transistors to finish of the channel boards.
   

   
   
  Khozmo Quad Attenuator
   

   
  Still waiting on the Case and Transformer, should be testing soon.
   
  Just like to thank Kevin for making this build easy enough to understand for general DIYers.


----------



## El_Doug

I'm at about the same point - I forgot to purchase a 3k resistor, and am waiting on my transformer and LSK389s.  Otherwise things are going great!  Mine are offboard though, and I'm having a local guy drill up my angle brackets and heatsinks - should be a relatively unique build


----------



## verwandlung

Quote: 





hdman said:


> Khozmo Quad Attenuator
> 
> 
> 
> ...


 

 Looks nice. Is there any particular reason why you chose the Khozmo Quad Attenuator instead of the Alps RK50? I am just curious to know. Some people told me that the Khozmo Quad Attenuator is cheaper _and_ better than the Alps RK50. Do you agree with that?
  s


----------



## bcg27

Quote: 





verwandlung said:


> Looks nice. Is there any particular reason why you chose the Khozmo Quad Attenuator instead of the Alps RK50? I am just curious to know. Some people told me that the Khozmo Quad Attenuator is cheaper _and_ better than the Alps RK50. Do you agree with that?
> s


 


  Someone told you wrong.


----------



## verwandlung

Quote: 





bcg27 said:


> Someone told you wrong.


 


  Good to know. Perhaps he just meant that it wasn't worth the price difference with the Khozmo, but I suspect that you will just tell me again that he told my wrong anyway, right?


----------



## HDMan

Quote: 





el_doug said:


> I'm at about the same point - I forgot to purchase a 3k resistor, and am waiting on my transformer and LSK389s.  Otherwise things are going great!  Mine are offboard though, and I'm having a local guy drill up my angle brackets and heatsinks - should be a relatively unique build


 

 Which 3K resistor are you going to use for the Bias? The Xicon resistor was out of stock from Mouser when I ordered. The Vishay resistor I ordered to replace it was spec'ed as the same rating.
   
  Spritzer also recommended the CMF60.
   
"You can also use Vishay CMF60 and CCF60, both are rated at 500V for a 1/2W+ resistor."  

  
  Quote: 





verwandlung said:


> Looks nice. Is there any particular reason why you chose the Khozmo Quad Attenuator instead of the Alps RK50? I am just curious to know. Some people told me that the Khozmo Quad Attenuator is cheaper _and_ better than the Alps RK50. Do you agree with that?
> s


 

 I wouldn't know, but others have reported good things about the Khozmo and it's more in my comfortable price range.


----------



## El_Doug

I ordered this, which is a Vishay.  So long as yours meets the spec requirements, it doesnt really matter which brand or range you go for. 
  
  Quote: 





hdman said:


> Which 3K resistor are you going to use for the Bias? The Xicon resistor was out of stock from Mouser when I ordered. The Vishay resistor I ordered to replace it was spec'ed as the same rating.


----------



## DaveBSC

Quote: 





verwandlung said:


> Looks nice. Is there any particular reason why you chose the Khozmo Quad Attenuator instead of the Alps RK50? I am just curious to know. Some people told me that the Khozmo Quad Attenuator is cheaper _and_ better than the Alps RK50. Do you agree with that?
> s


 

 The Khozmo is rated +/- 0.1dB for channel matching, from the first step to the last. No pot, including the RK50 can touch that. In terms of sound, I suspect the RK50 probably outperforms the standard Khozmo with Caddock resistors. The Z-foil versions may be a different story.


----------



## El_Doug

All stepped attenuators should have that level of channel matching - it would be just stupid if they were off by more than 0.1db  
  
  Quote: 





davebsc said:


> The Khozmo is rated +/- 0.1dB for channel matching, from the first step to the last. No pot, including the RK50 can touch that. In terms of sound, I suspect the RK50 probably outperforms the standard Khozmo with Caddock resistors. The Z-foil versions may be a different story.


----------



## bcg27

Quote: 





verwandlung said:


> Good to know. Perhaps he just meant that it wasn't worth the price difference with the Khozmo, but I suspect that you will just tell me again that he told my wrong anyway, right?


 
   
  Sorry I was reading on my phone and misread your statement - I thought you said that the RK50 was cheaper than the khozmo, which is definitely not the case. Certainly the Khozmo will have better channel matching, but the rk50 should be good enough that you won't be able to hear a difference. The main advantages of the rk50 are that it has 'infinite' resolution unlike the stepped attenuator which can get into a case where one step is too loud and the other is too soft. It also has a much better 'feel,' I much prefer a smooth turning pot to the clicks of the stepped attenuator. I can't comment on the sound since I have never heard an rk50 but the khozmo sounds just fine to me. Last I checked rk50s were going for over $700 so its a pretty massive price gap that definitely makes the rk50 not worth it IMO.
   
  For the best of both worlds check out amb's delta 1 stepped attenuator - 256 .5 dB steps so it is plenty fine grained to get desired volume, can be used with a RF remote control, and can also read a regular cheapo pot into an a/d to set the volume so you still get the pot 'feel.' Plus it can be built for about the same price as a khozmo if you use reasonable resistors. Takes up quite a bit of space and requires an additional 5V power supply which is why I didn't use one in my KGSSHV.


----------



## verwandlung

Quote: 





bcg27 said:


> Last I checked rk50s were going for over $700 so its a pretty massive price gap that definitely makes the rk50 not worth it IMO.


 


  I guess that is what the person I was referring to was saying. Thanks for you suggestion (amb's delta 1 stepped attenuator - 256 .5 dB steps).


----------



## johnwmclean

Quote: 





bcg27 said:


> The main advantages of the rk50 are that it has 'infinite' resolution unlike the stepped attenuator which can get into a case where one step is too loud and the other is too soft.


 


  ... and an advantage the Khozmo has over most other steppers is 48 positions.
   
  EDIT: Well at least DACT and Goldpoint.


----------



## pabbi1

I've never had that problem with either of my Khozmos, nor my 42 step Acoustic Dimensions.


----------



## bcg27

My khozmo was shipped with only two of four caddock input resistors. After a couple emails they mailed me replacements but it still seems QC is somewhat questionable.


----------



## sachu

I liked the Khozmo that is in Pabbi's stat amp. It is the caddock version. Very clean sounding compared to my TKD 4CP.
   
   
  Still i think the best option is to try out the Penny and GIles. At 350-375, its worth giving it a shot although channel matching is only decent.


----------



## HDMan

Seriously SumR have the most outrageous shipping prices for there transformers, must put alot of international customers off. They even offer Sea mail, prolly cause there Airmail is such a rip off.
   
  Next build I am going to go local for my transformers.


----------



## johnwmclean

Quote: 





hdman said:


> Seriously SumR have the most outrageous shipping prices for there transformers, must put alot of international customers off. They even offer Sea mail, prolly cause there Airmail is such a rip off.
> 
> Next build I am going to go local for my transformers.


 


  Welcome to the wonderful world of Canadian mail...


----------



## ujamerstand

As a Canadian I apologize.


----------



## Lil' Knight

Buying power transformers locally is a big plus for me  I imagine shipping cost for all the T2's transformers would be a chunk of money...


----------



## HDMan

Quote: 





ujamerstand said:


> As a Canadian I apologize.


 

 LOL


----------



## HDMan

Boards are complete, got everything except the Transformer, probably be waiting for that for awhile 
	

	
	
		
		

		
			





.
   
  Milling that front 10mm thick alloy was very tricky, lol.
   
  I am building the 500v version with onboard heatsinks and PC case fans for exhausting the hot air of the case. Built some rails directly above the heatsinks on the channel boards, 4 x 80mm fans, might go to 120mm fans at some stage, those really quite ones 
	

	
	
		
		

		
		
	


	




.
   
  After all this hard work, let's hope she works.


----------



## El_Doug

My boards are done too - did you not get your transformer from SumR?  I was told that if it wasn't done by today, it would certainly go out Monday. 
   
  Still... doesn't active cooling kind of defeat the purpose?


----------



## bcg27

Yea if you are using active cooling you could use much smaller heatsinks.


----------



## DaveBSC

Quote: 





hdman said:


> I am building the 500v version with onboard heatsinks and PC case fans for exhausting the hot air of the case. Built some rails directly above the heatsinks on the channel boards, 4 x 80mm fans, might go to 120mm fans at some stage, those really quite ones
> 
> 
> 
> ...


 

 Noiseblocker multi-frames are my favorites, and I'm pretty sure they are available at both 80 and 120mm. Keep in mind that many of the so called quiet fans are not quiet at all with 12V.


----------



## HDMan

Quote: 





el_doug said:


> My boards are done too - did you not get your transformer from SumR?  I was told that if it wasn't done by today, it would certainly go out Monday.
> 
> Still... doesn't active cooling kind of defeat the purpose?


 
   
   
  Well I figured that my PC is running at the same time as my amp anyhow, I use it as my source. If I build it as quite as my PC, then no probs.
   
  Yeh I ordered the SumR with non-priority mail, which I found out later meant by Sea 
	

	
	
		
		

		
			





. LOL 
   
  $98 shipping Airmail Priority for a $91 transformer, dang I was like, what.
   
  Its been 3 weeks now, prolly another 2 weeks.
  
   
  Edit:
   
  I ordered the CMF60 for the bias that was in the BOM here: https://docs.google.com/spreadsheet/lv?hl=en_US&key=0Aq_FzyStz20hdEE1SDR3Q3JWZU5ydGpjZ2xleDA3M1E&hl=en_US&f=true&noheader=true&gid=1
   
  Apparently it's no good, rated a bit under voltage at only 500v, lucky RS Online have the 3.5kv 0.5w under a different part number with free delivery in OZ.


----------



## jaycalgary

Shipping wasn't much for me because I am in Canada. It has been very very expensive for shipping from USA so I wouldn't blame Sumr especially if your looking for some high dollar airmail service. I just picked up my transformer today and the quality looks great to me. I don't want to get in to my story but I can say without a doubt Sumr is about the best customer service you will get this day in age. 

I hate getting stuck with having to use UPS for shipping from USA to Canada. They worked there way in with so bad that buying online they are the only option for shipping with so many company's. With what they do and how they charge these extra brokerage fee's it should be criminal. The worst/best example I have is I bought a 2nd hand pair of headphones before for $500 and it cost about $725 by the time I received them because of UPS fees.


----------



## johnwmclean

Quote: 





jaycalgary said:


> I don't want to get in to my story but I can say without a doubt Sumr is about the best customer service you will get this day in age.


 

 Totally agree, Richard is awesome to deal with, even for us southern convicts.


----------



## Beefy

Quote: 





jaycalgary said:


> Shipping wasn't much for me because I am in Canada. It has been very very expensive for shipping from USA so I wouldn't blame Sumr especially if your looking for some high dollar airmail service. I just picked up my transformer today and the quality looks great to me. I don't want to get in to my story but I can say without a doubt Sumr is about the best customer service you will get this day in age.
> I hate getting stuck with having to use UPS for shipping from USA to Canada. They worked there way in with so bad that buying online they are the only option for shipping with so many company's. With what they do and how they charge these extra brokerage fee's it should be criminal. The worst/best example I have is I bought a 2nd hand pair of headphones before for $500 and it cost about $725 by the time I received them because of UPS fees.


 

 Yeah, cost me $12 to get three units sent to me in Canada. Richard just passes on what it costs him, and you can't blame him for Canada Post.
   
  And I too hate UPS for USA sourced deliveries. Stupid brokerage fees, customs fees, and taxes. Terrible missed delivery practices. USPS and FedEx are both far more reasonable.


----------



## HDMan

She's a tight fit.
   

   
  The Hifi2000 case was designed to have the vent holes at the back, had to do some mods to turn the top and bottom chassis plates around so the vents were up front for ventilation with the channel board heatsinks. This is really just a rough version, need to do some cable management when the transformer arrives.
   

   
  I don't like the knob, I have ordered a bigger one, 51mm in silver color, cover up a couple of knicks to, . I took the front panel to a Metal worker, he put whiteout on the front to mark some spots to drill. He was taking to long getting around to it, so I had a crack at it myself, tough without pro tools, but it turned out alright except there are still some whiteout marks he put on there.
   
  I read WD40 helps to lift it off, might have to try it on the backside first.
   

   
  Anyhow, having loads of fun with the build.


----------



## DaveBSC

THL audio is a really great source for volume knobs. Ordering is a bit of a pain, but they have a ton of them.


----------



## bcg27

I think it's not a great idea to have a computer SMPS right in there next to the inputs to an amp with 60 dB of gain


----------



## Beefy

Quote: 





bcg27 said:


> I think it's not a great idea to have a computer SMPS right in there next to the inputs to an amp with 60 dB of gain


 

 Lets be honest here, its a bloody terrible idea.


----------



## bcg27

Just trying to be a little diplomatic 
	

	
	
		
		

		
		
	


	



   
  Also HDMan you know you need to be able to access the potentiometers with a small screwdriver to adjust offset and balance right? It looks like your fan assembly is blocking access.


----------



## HDMan

Quote: 





bcg27 said:


> Just trying to be a little diplomatic
> 
> 
> 
> ...


 

 Adjustment to the balance and offset can be done with the fan assembly removed first.


----------



## bcg27

Quote: 





hdman said:


> Adjustment to the balance and offset can be done with the fan assembly removed first.


 


  That may be, but the final adjustment should be made at the operating temperature of the amp. So generally with passive cooling you will let it sit and run for an hour or so and then make the final adjustment. If you do your adjustments without the fans on then the operating temperature is going to be very different and your offset and balance may be significantly off.


----------



## HDMan

Quote: 





bcg27 said:


> I think it's not a great idea to have a computer SMPS right in there next to the inputs to an amp with 60 dB of gain


 

 Well I researched previously on diyaudio.com, no indication from them that any interference would cause problems, the SMPS is elevated above the PCB's and power entering the case and it is incased in its own metal housing. Some people are even using them to power 200watt amplifier's, this amp only does what 20-30watt. What reasoning do you have for this conclusion that it will cause any issues with interference?
   
   
  http://www.diyaudio.com/forums/chip-amps/56615-computer-power-supply.html
   
  http://www.diyaudio.com/forums/chip-amps/77007-smps-questions.html


----------



## HDMan

Quote: 





bcg27 said:


> That may be, but the final adjustment should be made at the operating temperature of the amp. So generally with passive cooling you will let it sit and run for an hour or so and then make the final adjustment. If you do your adjustments without the fans on then the operating temperature is going to be very different and your offset and balance may be significantly off.


 

 It's no problem with the fan rack installed, I can easily get a small screwdriver down there.
   
  Thanks for trying to help though


----------



## jaycalgary

How many megs of ram does it have? What graphics card are you using?

I am building my case from scratch. I am hoping to post some pics soon. So far it is not working out for me. I'm over $300 so far in aluminum and material so far.About half is shipping costs. Many mistakes and change of designs wasted a good amount of material and now I am compromising. Mine is an off board design and I am on my 3rd try ordering heatsinks. first order was a pair at 10"x6" 1"fin to heavy for me. Second was a pair 10"x2" heatsinks that the whole unit would fit in a case that is 6" high, 9.25" wide and 13" deep. The heatinks would even be inside of this space.Amp boards would be still vertical but inside open area of the psu board eg one side the heatsink would run a little over top of the big psu heatsinks. Probably a really bad idea but that was my idea of how would Stax build it. I'm to much of an amateur so I changed back to similar to other builds but as compact as possible. The new build is 5" high 9.25" wide 13" deep. The new heatsinks will be 7.25"x5" 1"fin and mounted outside.. The psu is turned to the short side I hope this is all right? My toroid has an epoxy core and will be mounted vertically on an aluminum plate that also separates the psu from the toroid. Pics soon but am fishing for ideas if I will be in trouble with this so far?


----------



## spritzer

Quote: 





bcg27 said:


> That may be, but the final adjustment should be made at the operating temperature of the amp. So generally with passive cooling you will let it sit and run for an hour or so and then make the final adjustment. If you do your adjustments without the fans on then the operating temperature is going to be very different and your offset and balance may be significantly off.


 

 Yeah and those fans are a stupid idea of epic proportions.  If this is a 500V version then you will have major drift issues as the CCS will never settle down and this is an audio amplifier, it is supposed to get hot.


----------



## arnaud

He he, maybe we have found a new future mikhail


----------



## jaycalgary

Here is a pic of what I am trying to do. Waiting for the right size heatsinks. So far it looks like an old piece of test equipment. I can't say it is worth all the effort to hand build a case. I am just hoping it can work.


----------



## HDMan

Quote: 





spritzer said:


> Yeah and those fans are a stupid idea of epic proportions.  If this is a 500V version then you will have major drift issues as the CCS will never settle down and this is an audio amplifier, it is supposed to get hot.


 

 No probs, I'll drop the fans then. Thanks for the help.
   
  Anybody thinking of buying international from SumR, I wouldn't.
   
  I was advised shipping by non-priority would take, quote "a few weeks", only to find out after the transformer was sent that it actualy states 4-6 weeks on Canada Posts website, from the time it leaves Canada's shores by SEA 
	

	
	
		
		

		
			





. I'll say that again, by SEA.
   
  Now Auspost has informed me 6-8 weeks from the date it leaves canada's shores.


----------



## HDMan

Seriously looks like fake IXTP01N100D's are going around.
   
  I have ixys10m90s parts from a friendly Headfier (supposedly from Future Electronics) and some IXTP01N100D's from a friendly DIYaudio'er, they both look the same in writing style and appearance, shiny plastic housing and typing style are identical.
   
  I also got some IXTP01N100D's from Little Diode (now refunded) which look remarkably different in typing style and plastic housing (dull, not shiny), me thinks this might be a fake. I can post pics if anybody needs to see them.


----------



## jcx

who can afford to fake $1 parts?


----------



## HDMan

Quote: 





jcx said:


> who can afford to fake $1 parts?


 


  They sell for $12 at Little Diode each. Fakes and a rip off.


----------



## Sathimas

Just because I'm curious - how much would just the parts for a KGSSHV be? (working amp without enclosure)


----------



## livewire

A lot of variables there.
  Quality of the parts used, who you buy them from, shipping costs, etc.
  An "economy build" can be done for around $1000 USD. (parts cost)


----------



## vvs_75

I have all the parts except transformer, minus case would be roughly $800, + $100 for transformer and  $250 for the case, that comes to  about $1200 in all parts + lots and lots of sleepless nights.


----------



## jaycalgary

I still need wire. Does anyone know what gauge to use? I need Peek M3 screws and that looks like it will be over $100 to get shipped. Anyone have 10-20 they would sell me? I don't really want a volume pot but not sure how easy it is to bypass and not use one for now. I am close to done with the case. Not perfect but it is solid. I am thinking of using some model glue around joints and rivets. Any ideas or opinions are appreciated.


----------



## DaveBSC

Quote: 





jaycalgary said:


> I still need wire. Does anyone know what gauge to use?


 

 All of the low voltage signal wiring in my HV is 24AWG. The power supply, bias and other high voltage wire is 18AWG Furutech. Obviously anything you use for that needs to be rated to handle 600V+.


----------



## kevin gilmore

I use 20 gauge teflon because it is rated for the voltage, and i have a bunch of it.
  Same as i use on the T2.


----------



## jaycalgary

I found two company's in Canada here that would be better to get the wire from for me. It is hard to find the voltage rating on most wire and that sounds really important with this amp. 
Take Five Audio has Neotech hookup wire that is rated for 600v but maybe it needs to be a AC or a DC rating because there is a difference that I forget at the moment.
I found Neotech UPOCC 20 AWG, Teflon Insulation and only $2.58 a foot. This is suitable?

The other store is PartsConneXion ant they have Neotech too but they don't give the voltage. They also have Neotech 20AWG Silver. Bad idea?
They have the Furutech 18AWG and I don't mind buying some great wire for this project. I really don't need that much. Too bad they
don't show voltage rating on other wire. Just running 20 AWG on everything sounds easy enough for me. I really should keep it as simple as possible. 

Been looking at there Khozmo Attenuator but even on my 717 it is switched off and I use my volume on Wyred4Sound Dac2. I just have yet to see any
amps like these that don't have a volume. I also plan on running off XLR. I am just taking it slow and learning from the experience.Thanks.


----------



## DaveBSC

Quote: 





jaycalgary said:


> I found two company's in Canada here that would be better to get the wire from for me. It is hard to find the voltage rating on most wire and that sounds really important with this amp.
> Take Five Audio has Neotech hookup wire that is rated for 600v but maybe it needs to be a AC or a DC rating because there is a difference that I forget at the moment.
> I found Neotech UPOCC 20 AWG, Teflon Insulation and only $2.58 a foot. This is suitable?


 
   
  I wouldn't recommend the Neotech. I tried it with mine and had shorting problems. I ended up with the Furutech Alpha-18 from PcX. In terms of voltage, if the wire is rated for VAC, you can calculate the VDC by multiplying times 1.414. For your signal wiring, you can go with pretty much whatever you like. I went with VH Audio unicrystal silver with their "airlok" foam teflon. Really nice stuff. You could also use Mundorf or Audience OCC Auric wire, both are excellent and PcX carries both.
   
  I don't think there's any need to use a volume control if you don't want one... but I think a high quality SA will likely outperform DAC volume controls that are digital domain.


----------



## jaycalgary

Thanks that is the direction I will go. If I can ask one more thing and I am guessing again but if I leave out the SA do I need to replace it with a couple resisters? I understand I may lose a little but it will never be hard to install one.


----------



## Sathimas

Quote: 





> An "economy build" can be done for around $1000 USD. (parts cost)


 
   
  Well, this is far more than I expected ...
  Nothing for me at the moment (and in the nearer future)


----------



## HDMan

I have a working Power Supply, but my DMM shows some wierd readings after 10 seconds, slow drop in volts. It could be the DMM though. Reads 502v, then drops gradualy more and more, It now seems to be stabilizing at 398v.


----------



## johnwmclean

Quote: 





hdman said:


> I have a working Power Supply, but my DMM shows some wierd readings after 10 seconds, slow drop in volts. It could be the DMM though. Reads 502v, then drops gradualy more and more, It now seems to be stabilizing at 398v.


 
   
  Over both - and +?


----------



## HDMan

I couldn't get a reading from -, + was 502v then dropped slowly. Tomorrow I will test extensively.


----------



## deadlylover

I'd first check the secondaries of the transformer to see if the windings are labelled wonky.
   
  Good hunting.


----------



## Beefy

While I much prefer to see DIY projects turn out well, I'm going to start looking for train wreck GIFs in anticipation......


----------



## johnwmclean

Quote: 





beefy said:


> While I much prefer to see DIY projects turn out well, I'm going to start looking for train wreck GIFs in anticipation......


 
   
  I just hope the grim reaper doesn’t make an appearance.


----------



## nattonrice

Quote: 





lil' knight said:


> Buying power transformers locally is a big plus for me
> 
> 
> 
> ...


 
   
  It sucked royal ass.
  Compounded by having the b24 transformer and some dac stuff in the same shipment.


----------



## wink

Five transformers for the KGSSHV and two for the F5 in one shipment. Thankfully it came in 4 boxes. From SumR in Canada to Aus by slow boat.


----------



## nattonrice

I refuse to wait for slow boat... the premium for the 3-5 day jobbie is like 50 bucks.
  If it's a big order then it's worth it from a bald spot minimization point of view.


----------



## HDMan

Quote: 





beefy said:


> While I much prefer to see DIY projects turn out well, I'm going to start looking for train wreck GIFs in anticipation......


 
   
  Such a Drama Queen


----------



## HDMan

Quote: 





nattonrice said:


> I refuse to wait for slow boat... the premium for the 3-5 day jobbie is like 50 bucks.
> If it's a big order then it's worth it from a bald spot minimization point of view.


 
   
  Well Richard was saying to me 3 weeks for Surface Mail, turned out to be 2 months. SumR need to understand there shipping ETA's a bit better, I also would have went with Air Mail had I known.


----------



## sachu

there are other folks who manufacture transformers ..you do know that right? especially in australia..Why only ordering from SumR?


----------



## HDMan

Woohoo, healthy Power Supply, reading 499v on the minus rail and 502v on the plus rail. Sorry there are no explosions for you Beefy.


----------



## El_Doug

what changed between then and now? 
   
  Quote: 





hdman said:


> Woohoo, healthy Power Supply, reading 499v on the minus rail and 502v on the plus rail. Sorry there are no explosions for you Beefy.


----------



## HDMan

Quote: 





el_doug said:


> what changed between then and now?


 
   
  It was late last night, DMM was going bonkers.
   
  Channel boards are lighting up except for one LED in the same spot on both boards, hope there are not fake parts, I got 2 different batches of IXYS parts that looked completely different.


----------



## J-Pak

Here is a photo of my verified authentic N100D
   
  (large, unresized image)
  http://home.comcast.net/~drnath/diy/100d.JPG


----------



## HDMan

.


----------



## johnwmclean

Not checking the transformer outputs in isolation before powering anything...
  Not testing the PSU 15 -/+ before powering the first amp board...
  Testing the other amp board without finding out what was wrong with the first board...
   
  PRICELESS
   
  ...and Richard usually supplies paperwork with specs, have you checked the data?


----------



## HDMan

Quote: 





johnwmclean said:


> Not checking the transformer outputs in isolation before powering anything...
> Not testing the PSU 15 -/+ before powering the first amp board...
> Testing the other amp board without finding out what was wrong with the first board...
> 
> ...


 
   
  Checked the Transformer, all good, 500v and 30v respectively
  Checked the PSU -15 +15 = 30v all good.
  Tested both at the same time, I will try 1 at a time.
   
  Yes I have checked the data, correct colour matching for 240v input.
   
  Tested one at a time, same thing. I know a guy with an osciliscope, lets see what we can see there.


----------



## deadlylover

Quote: 





hdman said:


> Channel boards are lighting up except for one LED in the same spot on both boards, hope there are not fake parts, I got 2 different batches of IXYS parts that looked completely different.


 
   
  Why do I have a nagging feeling it's the unnecessary LED for the IXYS current sources. 
	

	
	
		
		

		
			




   
  I'm just taking the piss, no hard feelings bro, best of luck.


----------



## livewire

@dl - Good observation!


----------



## HDMan

Quote: 





livewire said:


> @dl - Good observation!


 
   
  Lol, as if.
   
  Its the LED that runs off the 15v line. It comes on when powering down for 2 seconds only.


----------



## Beefy

Must. Resist. Urge. To. Laugh. Hysterically.
   
  SO.......... are the LEDs installed the right way? Power supply polarity correct?


----------



## wink

sachu posted:-
   
   
  Quote: 





> there are other folks who manufacture transformers ..you do know that right? especially in australia..Why only ordering from SumR?


 
  I tried about 4 places in Oz and none would pot them in mumetal, and charged as much for their vanilla transformer as it cost me for SumR's premium jobs shipped here to the antipodes.
  This is a no-brainer.


----------



## HDMan

In way over my head here, lol.
   
  It's going to the repair shop after i smelt smoke, pop crakle on one of the channel boards. Now you can luagh BEEFY.


----------



## kevin gilmore

Waiting to hear if one of the outputs is at +450 and the other at -450 which is strictly an adjustment problem.
  This condition steals enough current due to the feedback that the current source does not work.
   
  The easiest way to adjust this is to set the offset pot to maximum resistance, then adjust the balance
  pot so that both outputs are the same voltage. (differential)  Then measure one of them to ground
  and adjust the offset pot for 0 volts.  Repeat a few times.
   
  Its much easier if you adjust the pots to center before you solder them in.


----------



## arnaud

hdman said:


> In way over my head here, lol.
> 
> It's going to the repair shop after i smelt smoke, pop crakle on one of the channel boards. Now you can luagh BEEFY.




I surely wont be sending you my 009 to plug into this thing


----------



## HDMan

Quote: 





arnaud said:


> I surely wont be sending you my 009 to plug into this thing


 
   
  Lol, I don't think I will either.


----------



## J-Pak

KGSSHV: not a good first amp to build. Shocking news.


----------



## Nebby

Well hopefully that was a lesson learned. When multiple people tell you something is a bad idea, it's important to keep in mind that they may be right.


----------



## HDMan

Quote: 





nebby said:


> Well hopefully that was a lesson learned. When multiple people tell you something is a bad idea, it's important to keep in mind that they may be right.


 
   
  I know, but I am a stubborn bugger, I gave it a good shot. Got the power supply working but the channel boards just didn't get right. I will take it to the repair shop, if they can't fix it I will sell off parts and live with the SRM-727. I could keep going with it, but I just don't have the spare time.


----------



## Nebby

I only ask because I'm curious, but what happened to the tech guy that was going to do the power-up and testing? Did the deal fall through?


> So that any of you feel safer helping me, *I will tell you that I do not plan on powering it up and testing it myself*, I will have a tech guy do the final stages for me and get it running, I simply want to populate the PCB's, make the case and fit the parts accordingly.


----------



## HDMan

Quote: 





nebby said:


> I only ask because I'm curious, but what happened to the tech guy that was going to do the power-up and testing? Did the deal fall through?


 
   
  He took a good look at it, but he wasn't confident enough in the end. He showed me how to hook up the transformer/power entry/fuse. I think I am going to quit while I am ahead, I have a repair shop that I will try, after that the parts are up for grabs. Prefer those interested from Australia. I will probably have:
   
  Working Power Supply (500v)
  Transformer (500v version) (AC input 240v and 100v optional)
  Khozmo Quad Attenuator
  Case with stax entry, power switch, xlr inputs and power entry module.
  2 x channel boards (not entirely functional)
  A few spare transistors and resistors.
   
  The channel boards may be a simple fix for someone that is in the know.
   
  Also have for sale: 2 x KGSSHV (off board heatsink) PCB boards rev0.4 and 2 x KGSSHV Power boards rev.0.6


----------



## johnwmclean

Well at least you have the guts to own up that you were out of your depth, that is admirable 
	

	
	
		
		

		
			





.
   
  I sent you a pm.


----------



## sachu

that sucks dude..i was really rooting for you here.


----------



## arnaud

At least, you did not kill yourself, that is admirable!


----------



## nattonrice

Quote: 





arnaud said:


> At least, you did not kill yourself, that is admirable!


----------



## kevin gilmore

We all know a person that did a diy T2 as his first project ever.
  And got it to work. And it still works.
   
  This is not something you can slap together in a couple of hours.


----------



## Beefy

Quote: 





hdman said:


> I know, but I am a stubborn bugger, I gave it a good shot. Got the power supply working but the channel boards just didn't get right. I will take it to the repair shop, if they can't fix it I will sell off parts and live with the SRM-727. I could keep going with it, but I just don't have the spare time.


 
   
  I'm not going to gloat....... but I am going to berate you for giving up so damn quickly. Suck it up princess, and go through some proper troubleshooting!


----------



## spritzer

Quote: 





beefy said:


> I'm not going to gloat....... but I am going to berate you for giving up so damn quickly. Suck it up princess, and go through some proper troubleshooting!


 
   
  Yup, you only can give up when you've swapped out all the parts that could be acting up and it still doesn't work. Then you just stuff a spare PCB to get the bloody thing working.


----------



## HDMan

Quote: 





spritzer said:


> Yup, you only can give up when you've swapped out all the parts that could be acting up and it still doesn't work. Then you just stuff a spare PCB to get the bloody thing working.


 
   
  Thanks Spritzer, kick in the butt was what I needed (what a cry baby, lol) 
	

	
	
		
		

		
		
	


	



   
   
  Anyways, so I took the amp to a guy and he soldered the heatsinks properly, my crappy little soldering iron wasn't cutting it, couldn't get a high enough heat.. Now I have one working front channel board and the other one, the .47/50v capacitors both of them are black roasted crispy charcoal 
	

	
	
		
		

		
		
	


	




. I tested the other ones in that batch, they are defective.


----------



## spritzer

Did you use tantalum caps?  Some of them are directional so yeah, that will not end well.  Also stay far away from cheap caps on ebay. 
   
  I used 1uf/50V Wima MKS caps in my amps because I had them and they fit perfectly.  These caps are just for local PSU filtering so pretty much anything works.


----------



## HDMan

Quote: 





spritzer said:


> Did you use tantalum caps?  Some of them are directional so yeah, that will not end well.  Also stay far away from cheap caps on ebay.
> 
> I used 1uf/50V Wima MKS caps in my amps because I had them and they fit perfectly.  These caps are just for local PSU filtering so pretty much anything works.


 
   
  I used the .47uf/50v caps from the BOM.  http://au.mouser.com/ProductDetail/Kemet/C330C474M5R5CA/?qs=sGAEpiMZZMukHu%252bjC5l7YXvEg12wCzMcHJBU5xTZz50%3D
   
  4 out of 5 are defective, go figure hey?
   
   
  When you say anything works, do you mean any caps that are 50v? Please explain further.


----------



## spritzer

80% failure rate isn't normal with any part so something is very wrong somewhere else. 
   
  Any non polar film cap that fits and meets 50V spec will work.  No sense in going to big in value though.


----------



## Victor Chew

Please dont ever give up. Its a big learning curve you have here. Close up pictures of your boards.and your wiring will certainly help.


----------



## Victor Chew

Congratulations. After you have cased up everything, check the balance and offset again. This time out of the stax jack. Be careful not to slip your probes or poke them into the wrong place and short the amp again. If necessary draw a picture of the stax connections on a piece of post it and paste it beside the stax jack for this purpose, as the wiring are different viewed from the front and the back. After that leave the balance and DC offest adjustment alone for a long long time to come; then followed by the most important thing. Enjoy your music!!!!!


----------



## HDMan

I left the amp on for 1/2 to 1 hour while adjusting the balance first, then offset, left it on until there was a stable reading of 0Vdc for at least 15 minutes, the amp was warm (incase before i hooked up the outputs). I haven't checked it through the stax jacks, do you think this is necessary after what I have already done?
   
  Anyways, just hooked it up to test her out, running superbly, sound is amazing with the A8 Realiser using the 007-MK1's, really took it up a few notches. Before I had realism, now it is life like.
   
  Watched some of my favourite Bluray's, wow, they sound completely different with the stax, reminds me of some really high end speakers. This is my first experience with stax, never owned any before, just listened to some at the store. First Stax amp and first Stax headphones (MK1's), what a treat.


----------



## Victor Chew

If you are happy with the dc offset and balance then you can leave the advistments as they are. I often double check at the stax jack and make any final adjustments if necessary.
   
  What is this A8 Reaslier thing for? Interesting and curious! You said it took the sound up a few notches.


----------



## HDMan

Quote: 





victor chew said:


> If you are happy with the dc offset and balance then you can leave the advistments as they are. I often double check at the stax jack and make any final adjustments if necessary.
> 
> What is this A8 Reaslier thing for? Interesting and curious! You said it took the sound up a few notches.


 
   
  http://smyth-research.com/products.html
   
Smyth Research recommend and sell the Realiser with Stax headphones, hence the reason I was chasing some high end Stax gear and the fact I have a PRIR calibration with the Acapella Spharon Excalibur horn speaker, 7.1 surround sound made from 2 very high end speakers. Beyond Audiophile.
   
  http://cybwiz.blogspot.com.au/2011/11/setup-acapella-spharon-excalibur-horn.html
   
   
  If you would like to read more about the Realiser from users, follow the headfi thread here: http://www.head-fi.org/t/418401/long-awaited-smyth-svs-realiser-now-available-for-purchase/1755#post_8385478


----------



## verwandlung

Quote: 





hennyo said:


> I am undergoing building KGSSHV, and I'm ******* proud of it.


 
   
  http://www.head-fi.org/t/610131/michael-bean-hennyo-stole-my-money
   
  I came very close to order a KGSSHV from this person. It goes without saying that I am glad I didn't. Too bad that I few people did. Just thought that this should be well known.


----------



## Beefy

Quote: 





verwandlung said:


> http://www.head-fi.org/t/610131/michael-bean-hennyo-stole-my-money


 
   
  I knew that guy was going to do something like that. His work quality was crappy, and his attitude questionable.
   
  This is why it is worth waiting in line for something from Headamp.


----------



## verwandlung

Quote: 





beefy said:


> I knew that guy was going to do something like that. His work quality was crappy, and his attitude questionable.
> 
> This is why it is worth waiting in line for something from Headamp.


 
  I cannot agree more with the fact that he had, to say the lease, a “questionable attitude,” which prevented me from moving ahead and order the amp from him.
   
  PS. And you know very well that I would be the first to wait in line if Justin ever decides to build that amp! But I'll spare you and leave it there.


----------



## spritzer

Glad you got it working.  Kevin is indeed the nicest guy one could find and I'm happy to call him my friend.  
	

	
	
		
		

		
		
	


	



   
  As for the tough love, with DIY there is really only experience and sometimes we have to force people to listen.  Most of us have a burning wreck of something in our past and we try to prevent other people from making those same mistakes.


----------



## HDMan

Finished the inside:

   
  What's the go with the Khozmo, is it supposed to have little pops/crackling inbetween steps while turning the knob? I think I remember someone else having this problem with there's in another thread.


----------



## sachu

must say..you really did a good job there..definitely had my doubts on this turning out ok, let alone as nice as it looks. enjoy


----------



## Beefy

Quote: 





hdman said:


> Finished the inside:
> 
> 
> What's the go with the Khozmo, is it supposed to have little pops/crackling inbetween steps while turning the knob? I think I remember someone else having this problem with there's in another thread.


 
   
  Doesn't look too shabby at all HDMan, well done fitting it all in that chassis.
   
  With regards to your problem and solution...... etiquette dictates you describe what the problem was, and how you fixed it. Next person with the same problem can read your post, rather than bothering Kevin.


----------



## kevin gilmore

Lets see, correctly assembled, correctly wired, correctly grounded.
  And it works.
   
  Looks good to me.
   
  Much bigger pictures are required.


----------



## HDMan

Quote: 





beefy said:


> Doesn't look too shabby at all HDMan, well done fitting it all in that chassis.
> 
> With regards to your problem and solution...... etiquette dictates you describe what the problem was, and how you fixed it. Next person with the same problem can read your post, rather than bothering Kevin.


 
   
  Well I don't know if it is a problem/solution that will help others, but I accidentaly shorted the circuit, testing it while it was out of the case. After numerous attempts firing the bad channel board up to locate the problem, I then started to notice that the .47uf/50v resistors were colouring a dark colour. It is very difficult testing capacitors and transistors in circuit it seems.
   
  Not boasting, but it would seem that actualy first time round all components were correctly mounted (accept for the heatsinks) (then I shorted the circuit, I think it was cause of the heatsinks not being mounted properly). Not bad for a first attempt, the only other time I had ever soldered was with my headphones to do a recable. I am mechanicaly minded though, spent many hours under the hood of my car. I probably should have done some practice soldering first, but I figured that I had some spare PSU boards anyway, so I started with the PSU first. Watched a few youtube vids from some professionals, crash course, lol. (don't try this at home kiddies)
   
  Quote: 





kevin gilmore said:


> Lets see, correctly assembled, correctly wired, correctly grounded.
> And it works.
> 
> Looks good to me.
> ...


 
   
  Thanks Kevin, good to know I got the basics right.
   
   
  Can you give some insight into the version I built. It is the IXTP01N100D optional current source, with the all out 500v PSU (It was a bit ambitious). I know that many others are using the 500v PSU for the off board version. I can build a 450v PSU, replace it and use the 500v for the next off board build. The heat doesn't seem outrageous to me, although you may know more about the longevity of the parts at that temperature.
   
  How does it differ from the 450v and how does the IXTP01N100D differ from the 2SA1968, someone was saying the 2SA1968 sound sweeter? I may use that transistor next time round.


----------



## johnwmclean

I think Kevin said the 2SA1968’s sounded sweeter, although the ixys run at higher voltage thus a larger voltage swing. BTW the 2SA1968 is discontinued and rare as hens teeth.
   
  Congrats HDMan on a great build,


----------



## HDMan

Thanks John, I hope I can build my next one as good as yours. What are your blue resistors you used, are they expensive?
   
  I have noticed that running the amp with the lid on and off produces a 5v difference from the outputs, so I have been dialing it back 5v then putting the lid on and testing further. How accurate do the voltages have to be to zero.
   
   
  These are my voltage readings after 1 hour operation:
   
  Left Balance
   

   
  Right Balance
   

   
  Left Offset
   

   
  Right Offset
   

   
   
  P.S really need to get some KGSSHV badges, I'm on a budget so engraving is not happening.


----------



## sachu

^ you are plenty fine with those readings IMO


----------



## ujamerstand

Looks like a good rig. How'd you like it with the smyth realiser thus far?


----------



## HDMan

Quote: 





ujamerstand said:


> Looks like a good rig. How'd you like it with the smyth realiser thus far?


 
   
  Yeh it works tremendously well with the Realiser. I know now why Lorr from Smyth Research recommends Stax with the Realiser. Previously I was using some AD-700's from the headphone jack on the Realiser, although this worked quite well, it is no comparison to the KGSSHV/007-MK1 combo. The rear channels are so much more out of head, the front seperation between channels so vivid and the speed and resolution of the Stax are amazing.
   
  This is a cliche, but it serves true, that I am hearing so much more detail now that I never recognized was there before. The Stax have allowed the Acapella Excalibur Spharon (PRIR), to really show there true potential in this sytem. Although the realiser can adjust any headphone to equalize the frequency range, headphones themselves still add a type of influence to the end result.
   
  After I get a balanced DAC, I will be using the balanced XLR's on the KGSSHV, should give some more gain there, still some room for improvement.


----------



## Victor Chew

Readings look good to me.
   
  Just trying to understand where the Realiser is placed in the chain. Since it is an audio processor, you use the Realiser between the CD player/source and the KGSShv correct? As the Reaslsier is SE only it means that you will have to use an adaptor to the balanced input at the KGSShv? Inshort, the realsier is like an equaliser but with surround function capabilities.
   
  If the above is correct, then if you use an XLR DAC how would you implement it with the Realiser?


----------



## HDMan

Quote: 





victor chew said:


> Readings look good to me.
> 
> Just trying to understand where the Realiser is placed in the chain. Since it is an audio processor, you use the Realiser between the CD player/source and the KGSShv correct? As the Reaslsier is SE only it means that you will have to use an adaptor to the balanced input at the KGSShv? Inshort, the realsier is like an equaliser but with surround function capabilities.
> 
> If the above is correct, then if you use an XLR DAC how would you implement it with the Realiser?


 
   
  Yes that's right, the Realiser processes the source material and outputs it to the amplifier or DAC > Amplifier. It has no decoding capabilities of it's own, so for example DTS-MA from a bluray source must be decoded by a BD/CD player or SSP and then transfered to the Realiser as decoded PCM up to 8 channels at 24/192khz, but it only outputs as 24/48khz. It can accept 7.1 analogue or HDMI as inputs and has Toshlink and L/R RCA as outputs, the Realiser will use it's onboard DAC if you output via the RCA's.
   
  If you use the analogue inputs there will be a D/A > A/D > D/A conversion process. If you use the HDMI in and Optical out to a DAC, the will only be one D/A conversion by the DAC
   
  There are a few variations that can be applied before the Realiser, but I am trying to keep the signal digital until it reaches a High End DAC. At the moment I don't have a DAC, so I am using RCA to XLR adaptors.
   
  So it will go, at least for me:
   
  PC Bluray/Xonar HDAV1.3 (HDMI) > Realiser (Optical) > DAC (Balanced XLR) > KGSSHV
   
   
  I realy wanted to add a SSP in between the Bluray player and the Realiser, but none that I know of output multi channel PCM over HDMI, only 2 channel. You could use the analogue outputs of the SSP, but that would break the digital chain. I did try a SSP, but returned it as it was a faulty unit and have now decided to keep the signal digital anyhow. There a lot of people using the Oppo Bluray Player as a source to the Realiser with great success.
   
   
  To finish off my system, I have yet to aquire a DAC and the SR-009's


----------



## spritzer

Stax say +/-10V for adjusting their amps and even that is a miniscule amount compared to the voltage these amps can swing. 
   
  The IXYS version of the amp will not settle down until it's fully warmed up so expect quite a bit of drifting.  The 2SA1968 is a better part is every way except its limited power handling, "low" voltage and price.  There is a reason why some of us have hundreds sitting around.


----------



## HDMan

Quote: 





spritzer said:


> Stax say +/-10V for adjusting their amps and even that is a miniscule amount compared to the voltage these amps can swing.
> 
> The IXYS version of the amp will not settle down until it's fully warmed up so expect quite a bit of drifting.  The 2SA1968 is a better part is every way except its limited power handling, "low" voltage and price.  There is a reason why some of us have hundreds sitting around.


 
   
  Spritzer in your opinion is there a real world difference in sound with the 2SA1968 compared to the IXYS?
   
  Can you actualy here a difference?


----------



## sachu

I think Headamp BHSE uses the IXYS parts..having heard the BH with the 1968 version of the BH i do my "The Rock" eyebrow raise at all the praise that folks seem to heap on the part.


----------



## kevin gilmore

The difference is very tiny, but if you listen long enough you might hear a difference.
To be fair about it you would have to listen to both at 450v power supplies.
Some people are still going to like one over the other anyway.
You could use the 10m90s part instead also at 450 v supplies, it is more thermally
Stable than the other ixys part.

There is a very slight difference in the distortion characteristics which most
Would consider at the noise floor level

If you are nelson pass and want the worlds most perfect current source that
has 100 volts of compliance, and an output of about 2 amps, sure you can
make something absolutely fantastic.

But if you want to make a current source with 900 volts ( or 1000 volts) of compliance
that runs at 2.5 ma and you want it to have a constant impedance for the entire
frequency range, then things get way tougher.

You can do a 2sa1968 with an led as a voltage reference and you end up with
something that is very stable with temperature, and with a 10pf capacitance, its
virtually flat with frequency.

You can do the same thing with a 10m90s but performance at 2.5 ma is not the
same as using it on a BHSE where it runs at 15ma. It is a sharp cutoff device
and is very stable with temperature.

You can do the same thing with the ixtp01n100d but it has more drift with
temperature.

You can also do it the way the T2 does with stacked 600 volt pnp transistors feeding
a 1000 volt npn transistor. Works great, but is more parts. And more heatsink. Very low
capacitance and absolutely flat with frequency.

You can do it with a simple resistor and then the thd goes up. Way up.

The T2 has a pair of servo's to keep the output voltages and offsets under 5 volts.
It takes a fair amount of board space. Maybe a future version of the kgsshv will
also have the same pair of servo's.


----------



## johnwmclean

Quote: 





hdman said:


> What are your blue resistors you used, are they expensive?


 
   
  Just your bog standard xicons from the BOM.


----------



## HDMan

I have some noise at full volume, 5 steps back from full volume is quite, I am using the Realiser as a volume control (digital) and will be using the Buffalo DAC (future build) with digital volume control also.
   
  Would it be worth removing the Khozmo if I want to use the KGSSHV at full volume permanently?


----------



## kevin gilmore

Noise at full volume is usually fixed with 100 ohms in series with the wiper of the volume control.
  To maintain full signal to noise, the volume control is usually a good idea. Then you turn up to
  full blast the dac, and adjust the volume control for just past your maximum listening level.


----------



## spritzer

Quote: 





sachu said:


> I think Headamp BHSE uses the IXYS parts..having heard the BH with the 1968 version of the BH i do my "The Rock" eyebrow raise at all the praise that folks seem to heap on the part.


 
   
  Facepalm was invented for comments such as these.  I know for a fact that you did not hear these two amps side by side so you are comparing current sources based on memory?  Let's just throw out any possibility for difference in the circuitry elsewhere in these amps (which are substantial), different parts used, different sources and the list goes on.  This is even more stupid than people comparing dac's based on the actual chips used and not worrying about any of the other circuits. 
   
  It is a simple fact that the Japanese parts are almost always superior.  Just compare the Toshiba BJT's vs. the Fairchild alternatives, far better specs but with almost all of the Japanese parts at end of life we have to make do.


----------



## sachu

did i even mention that i heard them side by side (facepalm moment!!??).. just said i heard the BH with your famous 1968 devices...it sounded meh. SO maybe its just that the BH does just sound OK to my ears.
   
  Hope you smacked your head hard with that facepalm.


----------



## blubliss

ignore list expanded


----------



## jcx

Quote: 





kevin gilmore said:


> Noise at full volume is usually fixed with 100 ohms in series with the wiper of the volume control.
> To maintain full signal to noise, the volume control is usually a good idea. Then you turn up to
> full blast the dac, and adjust the volume control for just past your maximum listening level.


 
  a detail but noise from the 400 Ohms of source degen/feedback R is larger
   
  and while many source may still work best with analog volume control the picture is changing
   
  several DACs with >120 dB dynamic range are available now - for some of these it no longer makes any difference as long as 24 bit PCM is driving the DAC - and even Windows can now be set for 24 bit output even with 16 bit source: the digital volume control math quantization at 24 bits output is way below any electronics noise floor
   
  and headphone listening doesn't reach the 0 dB SPL anechoic chamber threshold due to mechanical motion "microphonics"
   
  since ES headphones can't reach 120 SPL, hearing noise floor with headphones on is ~ 10 dB SPL then we really don't even "need" 120 dB dynamic range with good system gain structure


----------



## El_Doug




----------



## Lil' Knight

Neat


----------



## gilency

El_Doug, your amp is beautiful!


----------



## spritzer

Very nice indeed. 
   
  I was doing some inventory and I found 3 KGSSHV transformers so I guess I'll have to get cracking on some more amps.  
	

	
	
		
		

		
			





  First we need to finish these two new volksamp projects though... 
   
  Quote: 





blubliss said:


> ignore list expanded


 
   
  Been on mine for years but this was too stupid to ignore.


----------



## kevin gilmore

Nice amp indeed, definitely like the back panel

Hopefully production Teflon stax jacks soon


 Quote: 





jcx said:


> a detail but noise from the 400 Ohms of source degen/feedback R is larger



  
 I was referring to the noise some dac's make when they drive the input capacitance of the jfet directly
 with no series resistance. Reading HDman's comments now, i think he was talking about something else.


----------



## verwandlung

Quote: 





el_doug said:


>


 
  This looks very nice, refined, sober, with the name on the back! How many of them are you planning to build again?


----------



## El_Doug

Thanks for your kind words, everyone!  There actually will be a "KGSSHV" on the front, it is on the faceplate of the power supply (same size box).  However, just like the amp, the PSU front panel will be covered with black enamel and a matte clearcoat (just primed it tonight, actually) - thus the engraved "KGSSHV" will appear as a textured relief, but will not be a different color. 
   
  It'll look even better once I get my wife to use her camera + photography skills, instead of my point-and-shoot technique with my cell phone


----------



## J-Pak

Quote: 





el_doug said:


> Thanks for your kind words, everyone!  There actually will be a "KGSSHV" on the front, it is on the faceplate of the power supply (same size box).  However, just like the amp, the PSU front panel will be covered with black enamel and a matte clearcoat (just primed it tonight, actually) - thus the engraved "KGSSHV" will appear as a textured relief, but will not be a different color.
> 
> It'll look even better once I get my wife to use her camera + photography skills, instead of my point-and-shoot technique with my cell phone


 
   
  Is this an onboard or offboard build? Pics of the insides too please


----------



## El_Doug

Quote: 





j-pak said:


> Is this an onboard or offboard build? Pics of the insides too please


 
   
  offboard, of course


----------



## J-Pak

Quote: 





el_doug said:


> offboard, of course


 
   
  Very nice, what relay switching board are you using for the input selection?


----------



## kevin gilmore

I like it even more after that last picture.


----------



## chinsettawong

Very nicely done.  Wow!


----------



## Victor Chew

Very nice . Any PS pictures?


----------



## El_Doug

Still working on painting the front and drilling/wiring the inside, but here's the rear panel (for what it's worth): 
   

   
  Quote: 





victor chew said:


> Very nice . Any PS pictures?


----------



## Victor Chew

Nice. The PS and Amp will certainly look lovely side by side.


----------



## El_Doug

Quote: 





victor chew said:


> Nice.


 
   
  lol ty - sorry I don't have much else to show right now, as far as the power supply goes.  I did go out of my way to make the thing safer by using a female dc power connector on the PSU, and a male one on the amplifier


----------



## Lil' Knight

What power connectors are you using? Doesn't look like the usual Amphenol...


----------



## El_Doug

switchcraft conxall
   
  Quote: 





lil' knight said:


> What power connectors are you using? Doesn't look like the usual Amphenol...


----------



## HDMan

At what point is the inside of the case to hot for the components to handle and what is the best way to measure the temperature inside the case?


----------



## kevin gilmore

If you can hold on to the heatsinks for more than 5 seconds, its NOT too hot.
  temperature meters including the infrared ones work fine.
  Krell class hot is still ok.


----------



## tranhieu

Quote: 





kevin gilmore said:


> If you can hold on to the heatsinks for more than 5 seconds, its NOT too hot.
> temperature meters including the infrared ones work fine.
> Krell class hot is still ok.


 

 Does this also apply to other dynamic amps? I can't touch my b22's heatsinks for more than 5 seconds these days, and the summer hasn't come yet...


----------



## johnwmclean

MOSFETs maximum junction temperature is 175°C. Under 100°C junction temperature is recommended.
  Personally 60°C is my max limit, anything over that and I’ll start to consider alternatives.
  You have to consider all the components in the frying pan.


----------



## spritzer

With high ambient temp then the first things to go would be the electrolytic caps, especially the ones rated at only 85°C.  
   
  I just measured my KGSSHV which is in a pretty cramped chassis and the highest reading I got was 47°C.  This is with an IR thermometer measuring the output heatsinks so the ambient temp is much lower.


----------



## Victor Chew

My KGSShv runs about 85C on hot days at the hottest heat sinks (at the amps) where the temperature outside is about 34C to 35C. On cooler days the temperature drops. Do you guys think mine is running too hot? The PSU runs way cooler.
   
  I like the sun and I think it is nice. Equator benefits. But I am not sure if my KGSShv would agree with me.


----------



## HDMan

Quote: 





kevin gilmore said:


> If you can hold on to the heatsinks for more than 5 seconds, its NOT too hot.
> temperature meters including the infrared ones work fine.
> Krell class hot is still ok.


 
   
  Thanks, i'll try holding the heatsink trick.
   
  Quote: 





spritzer said:


> With high ambient temp then the first things to go would be the electrolytic caps, especially the ones rated at only 85°C.
> 
> I just measured my KGSSHV which is in a pretty cramped chassis and the highest reading I got was 47°C.  This is with an IR thermometer measuring the output heatsinks so the ambient temp is much lower.


 
   
  Yeh an IR thermometer would be good, the output heatsinks are the transistors next to the 180 ohm resistors right?
   
   
   
  What I thought previously about there being noise in the headphones at full volume (with no sound obviously), reason being that that the source was not turned on. When the source is turned on the noise goes away. Sounds much cleaner and more dynamic with the KGSSHV at full volume and the source turned down. Could it be a ground issue that i hear noise when there is no source plugged in? Offset also has moved quite a bit since i last measured it.
   
   
  Anybody else experience buzzing noise in there SumR transformer? It is quite loud.


----------



## Victor Chew

My KGSShv is dead quiet when the volume is full and the source is not plugged it.
   
  I think reduction in the souce output voulme means that the output voltage fed to the KGSShv is reduced. If I am correct you should  get quieter sound as some high frequency has been trimmed off. Some people like it though. so, its a matter of preference. 
   
  I think many things can cause the transformer buzzing, from parts to dc satuaration in the ac input lines. I too have that buzzing problem with my transformer. It is caused by the vibration of parts within the transformer. I have tried all practical methods to get rid of it but its still there. You may want to check with sumR.


----------



## johnwmclean

Have you tried using a thermistor in series on the primary of the transformer to tackle inrush?
  An underrated ssr can cause transformer buzz, I had to exchange a 25A for a 40A unit on my particular build for this very reason.
  http://relays.te.com/appnotes/app_pdfs/13c3206.pdf


----------



## HDMan

Quote: 





johnwmclean said:


> Have you tried using a thermistor in series on the primary of the transformer to tackle inrush?
> An underrated ssr can cause transformer buzz, I had to exchange a 25A for a 40A unit on my particular build for this very reason.
> http://relays.te.com/appnotes/app_pdfs/13c3206.pdf


 
   
   
  Thanks John, I do have a thermistor from the BOM that I ordered, what is the best or correct way to mount it?


----------



## nattonrice

RK50 
	

	
	
		
		

		
			




   
  Good form!
   
  Edit1: Directed at Doug
   
  Edit2: My post #888! My Chinese side rejoices in your amp's good fortune!


----------



## Victor Chew

John, 2 pieces of 2amp each in series. That should reduce the inrush current by quite a bit before it hits the transformer. 
  What are your thoughts on it? I believe Kevin did recommend this at the KGSSHV, Balanced Dynahi Rec A and Dynafet board run page 6.
   
  I was also thinking of putting a high rated cap in series at the mains to block any potential incoming dc causing saturation to the transformer.
   
  HDman, place the thermistor at the live. IEC to thermistor to switch.


----------



## HDMan

Quote: 





victor chew said:


> HDman, place the thermistor at the live. IEC to thermistor to switch.


 
   
  K, thanks.
   
  I was reading that soldering the thermistor can cause failure from repeated heating and cooling of the solder joint, what are your thoughts?
   
  What is the best way to mount it?


----------



## deadlylover

Quote: 





hdman said:


> I was reading that soldering the thermistor can cause failure from repeated heating and cooling of the solder joint, what are your thoughts?
> 
> What is the best way to mount it?


 
   
  Solder it, that's what the datasheet said.


----------



## HDMan

I used a 4 piece connector, buzzing noise from the transformer is still there. Sounds like a normal issue with the SumR.
   
  I got this from google:
   
Where does the constant humming sound come from in transformers?


*Answer*

 Most transformers make some audible sound at the frequency of the current they're operating on, for transformers running on utility power in the US this is 60 Hz. The sound is due mostly to the wire in the transformer coils and the steel in the transformer core vibrating at 60 Hz because of the interaction of the magnetic fields of these components. Some of this sound may also be due to something called magnetostriction in which the steel of the core actually expands and contracts with the fluctuating magnetic field.
   
   
   
  Actualy after more than 1 hour operation with the lid on, i can only just hold onto heatsinks for 5 seconds. I am going to get an IR thermometer.


----------



## gilency

Quote: 





victor chew said:


> HDman, place the thermistor at the live. IEC to thermistor to switch.


 
  Do you use only one or a total of 2?


----------



## HDMan

Noise in the headphones turned out to be the stax jack, amphenomal metal pins are realy loose, i had to do a realy tight job on soldering and heatshrink to get it tight. I see why everyone is using teflon stax connectors, can't wait to get some from Spritzer.


----------



## Victor Chew

Quote: 





gilency said:


> Do you use only one or a total of 2?


 
  I would use 2 in series.


----------



## Victor Chew

Quote: 





hdman said:


> K, thanks.
> 
> I was reading that soldering the thermistor can cause failure from repeated heating and cooling of the solder joint, what are your thoughts?
> 
> What is the best way to mount it?


 
  Thermistor works by increasing resistance when heat goes up. That way as resistance goes up it will block big rate of flow (ie. current) before it reaches the transformer. If the heat goes too high for the thermistor it will melt - like a fuse. Inshort, it is an "intelligent fuse".
   
  As far as I my limited knowledge goes,Torriodal transformer are more susceptable to saturation and buzzing. If you can hear it 3 feet away, that for me is not on. The buzzing is not dangerous to the equipment though, but irritating. However, over prolong periods of friction the coil insulation may be taken out and a short may occur.


----------



## gilency

​Victor, let me be sure I understand, you use to thermistors in series in the same wire or one thermistor per wire between the IEC and the transformer ?
And if I have a relay with the e24' is he thermistor really necessary?


----------



## Victor Chew

Quote: 





gilency said:


> Victor, let me be sure I understand, you use to thermistors in series in the same wire or one thermistor per wire between the IEC and the transformer ?
> And if I have a relay with the e24' is he thermistor really necessary?


 
  That depends. Amb site posted , "[size=x-small]An optional sensing loop employing thermal breakers can be used with the ε24, so that in the event of device overheat, it will be automatically shut off". If you have that you should not need additional thermistor.[/size]


----------



## johnwmclean

Quote: 





victor chew said:


> That depends. Amb site posted , "[size=x-small]An optional sensing loop employing thermal breakers can be used with the ε24, so that in the event of device overheat, it will be automatically shut off". If you have that you should not need additional thermistor.[/size]


 
   
  The ε24 does not provide any inrush protection, the ε24’s thermal sensing circuitry provides automatic shutdown from overheating i.e. intended for output devices.


----------



## Victor Chew

Thanks John. I stand corrected then.


----------



## HDMan

Replaced the black knob with a silver one, much nicer looking. The letters are to big, have ordered some small font and volume stripes. And a Danger High Voltage sign for the back panel (hole) that was cut out.


----------



## Forte

Nice, Where are you ordering  the lettering from?


----------



## HDMan

Quote: 





forte said:


> Nice, Where are you ordering  the lettering from?


 
   
  It's marine quality adhesive vinyl, fuel and water resistant, 5 year outdoor lifespan, indoor use should should be long lasting.
   
  http://www.ebay.com.au/itm/190539579423?var=490019157025&ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649


----------



## wink

Kerning looks pretty good.....


----------



## TMoney

FYI, HDMan, I think you mentioned a while back that you were having "clicking" issues with your Khozmo pot. I did as well. It eventually got worse and worse to the point that I pulled the pot out of the amp yesterday to send back to Khozmo for service or replacement.
   
  Keep an eye (or in this case, ear) on yours. If it starts getting worse, you might have to replace it as well.


----------



## gilency

Mine did not work at all. I emailed Khozmo but have not heard from them.


----------



## Nebby

Well I was starting to gain hope that Khozmo was a possible choice for an attenuator, but I think I'll go for other options


----------



## HDMan

Quote: 





tmoney said:


> FYI, HDMan, I think you mentioned a while back that you were having "clicking" issues with your Khozmo pot. I did as well. It eventually got worse and worse to the point that I pulled the pot out of the amp yesterday to send back to Khozmo for service or replacement.
> 
> Keep an eye (or in this case, ear) on yours. If it starts getting worse, you might have to replace it as well.


 
   
  Yeh it seems to be popping/crackling between steps more and more, me thinks not a good quality build, but nice sound none the less.


----------



## TMoney

Quote: 





hdman said:


> Yeh it seems to be popping/crackling between steps more and more, me thinks not a good quality build, but nice sound none the less.


 
   
  It does sound like the same problem I was having. Is it on one channel or both? Mine was only screwed up on one side.


----------



## deadlylover

If anyone's wondering, after letting my onboard version (@~460V) run for about four days straight, the heatsinks on the output devices measure about ~35C above ambient.
   
  If I remember correctly, the offset drifted something like 30V-40V or so with the ixys current sources, settling down rather quickly in five or ten minutes.
   
  How's it sound? Alright with my modded 007a's.


----------



## HDMan

Quote: 





tmoney said:


> It does sound like the same problem I was having. Is it on one channel or both? Mine was only screwed up on one side.


 
   
  Both channels for me, popping in each step as you turn the knob.
   
  Quote: 





deadlylover said:


> If anyone's wondering, after letting my onboard version (@~460V) run for about four days straight, the heatsinks on the output devices measure about ~35C above ambient.
> 
> If I remember correctly, the offset drifted something like 30V-40V or so with the ixys current sources, settling down rather quickly in five or ten minutes.
> 
> How's it sound? Alright with my modded 007a's.


 
   
  I have the 500v onboard version with the IXYS current sources and when i first start the KGSSHV, the offset voltages are +30-35v, then settling to almost zero after 30-60 minutes (from the output's O- O+), i think the balance voltages are not so different between cold and hot, maybe like 10-15v.


----------



## johnwmclean

I’m heading for a Khozmo replacement as well, clicking, distortion and leakage all of which is getting progressively worse.
  Actually... I think I’ll even ask for my coin back and just stick with a reliable DACT.
   
  Pissed to say the least...


----------



## johnwmclean

Mechanical life: >* 50 000 cycles *


----------



## HDMan

Quote: 





johnwmclean said:


> I’m heading for a Khozmo replacement as well, clicking, distortion and leakage all of which is getting progressively worse.
> Actually... I think I’ll even ask for my coin back and just stick with a reliable DACT.
> 
> Pissed to say the least...


 
   
  Let us know how it goes with a refund, I am seriously considering it myself. I guess we will have to pay for return postage eh!!!


----------



## Victor Chew

What alternative attenuators, besides the already mentioned DACT, can we go for at Khozmo's "level"?


----------



## kevin gilmore

shallco...
   
  pure silver things, and kind of pricey.


----------



## gilency

Goldpoint? Based in California. Has anybody used the Mini V?
I opened a dispute in Paypal and Khozmo as not answered yet.


----------



## Lil' Knight

Sad to hear there are more and more problems with the Khozmos... My friend just got one of his B22's channels burnt because of a short to ground in his Khozmo.


----------



## J-Pak

This is a bit weird, they usually make really good stuff in Eastern Europe


----------



## ujamerstand

Khozmos goes on to my blacklist.


----------



## maverickronin

Is anyone using relay switched resistor ladders or something similar?
   
  That's what I'd go for if I was building something that high end.  Perfect channel matching, pretty much as many steps as you want, and far fewer points of failure than the Rube Goldberg-ness of a 4 pole 20+ throw switch.


----------



## kevin gilmore

I use my 8 bit step attenuators. 256 levels, perfectly matched
And .5 db per step. And digital balance if you want it, since
You need a pair for balanced.

If you have to buy a pot, get the P&G, those seem the best of the bunch


----------



## Victor Chew

Infact my bread new DACT is starting to make louder "pop" noises as I turn the volume knob. Was there when I first installed it; then it went away as I used it more and more; and now (after about 150 to 200 hours of total use) the "pops" are louder than when first installed it. I have never had attenuator problems with carbon ones unless they were worn. That would be after years and years of use.
   
  Used to use the joshua peartree and it made a loud pop as the 12 o'clock was passed. Man the pop was loud.
   
  What is happening to the manufacture of these thing?. If anyone came up with a good attentuator at a reasonable price there will be gold literally poring in.


----------



## gilency

Victor, did you use the DACT for your KGSSHV?
Anybody knows where to buy the quad penny & giles?


----------



## Victor Chew

Yes, I use the DACT for my KGSShv. I have 3 more amps to build. 2 more than half done. I had placed an order with khozmo for 3 pieces of the round type but problems with their quality is forcing me to rethink for other choices.


----------



## J-Pak

IMO Elma rotary switches are fairly high quality and don't cost a fortune.


----------



## HDMan

I am leaving the Khozmo at a certain volume and adjusting with the A8 Realiser, seems to be soughting out the popping issue and I get to use a remote in my seat 
	

	
	
		
		

		
		
	


	



   
   
  On another note:
   
  I just included a DAC with balanced XLR outputs, before i was using a RCA to XLR adaptor out of the Realiser. I can't really tell much difference, what am I looking for using balanced inputs on the KGSSHV?


----------



## Victor Chew

I believe that technically, double the voltage swing as signal input is x2 as compared to RCA; because XLR is pull and push (hot and cold will pull and push the signal). This gives us double the power. Using RCA only means that only half of each amp board in the KGSShv is amplifying the signal; either pull or push only depending whether you ground the hot or the cold.
   
  Additionally, balanced will cancel out noise, whereas RCA would not.
   
  In terms of sound, XLR should sound more powerful, especially when used with the hard to drive headphones (eg. O2mk1). Especially at the bass frequency, where the control comes.
   
  I think in your case, you ought to fix the attenuator level of the source and use the Khozmo to do the rest. You are doing it the other way round and lowering the voltage swing which will cause a voltage sag if the impedance at the Khozmo is low at the set level (ie. being a shunt attenuator the input impedance at different travel will have a different impedance). If the voltage sags, you will hear less high frequency, and the music will sound more fat and wooly. However, I do stand corrected inrespect of the above if the experts feel otherwise. 
   
  If there are "pops" in the Khozmo, perhaps you might want to try rotating the attenuator from zero to max as few times, of course with the amp off, to see if it solves the problem. Works on my DACT but after a while the "pops" come back.


----------



## HDMan

Quote: 





victor chew said:


> I believe that technically, double the voltage swing as signal input is x2 as compared to RCA; because XLR is pull and push (hot and cold will pull and push the signal). This gives us double the power. Using RCA only means that only half of each amp board in the KGSShv is amplifying the signal; either pull or push only depending whether you ground the hot or the cold.


 
   
  Yep your right, after carefully A/Bing back and forth with a single DTS-MA test track, plugging the RCA's then back to the XLR's, I now can here what you mean, there is a more powerfull sound through the XLR's.
   
  Pops are not so prominent now, XLR's and the Khozmo pot turned down helps.


----------



## deadlylover

Quote: 





victor chew said:


> I believe that technically, double the voltage swing as signal input is x2 as compared to RCA; because XLR is pull and push (hot and cold will pull and push the signal). This gives us double the power. Using RCA only means that only half of each amp board in the KGSShv is amplifying the signal; either pull or push only depending whether you ground the hot or the cold.


 
   
  I'm pretty sure you get a balanced output no matter what input you use, using XLR just means double the output voltage, which doesn't really make a difference.


----------



## HDMan

Pops in the Khozmo are not there if I turn the knob fast.


----------



## Victor Chew

Quote: 





deadlylover said:


> I'm pretty sure you get a balanced output no matter what input you use, using XLR just means double the output voltage, which doesn't really make a difference.


 
  If you use RCA you will probably ground the cold portion, which means there will be no signal from the cold. This leaves only the hot to provide the signal, therefore only have half the board pumping up the signal.


----------



## deadlylover

Quote: 





victor chew said:


> If you use RCA you will probably ground the cold portion, which means there will be no signal from the cold. This leaves only the hot to provide the signal, therefore only have half the board pumping up the signal.


 
   
  The amp is fully balanced like most stat amps, you will get a balanced output even with a single ended input, it doesn't matter.


----------



## johnwmclean

Quote: 





lil' knight said:


> Sad to hear there are more and more problems with the Khozmos... My friend just got one of his B22's channels burnt because of a short to ground in his Khozmo.


 
   
   
  A short to ground from inputs shouldn’t cause this problem. The outputs on the other hand.....


----------



## kevin gilmore

Quote: 





deadlylover said:


> I'm pretty sure you get a balanced output no matter what input you use, using XLR just means double the output voltage, which doesn't really make a difference.


 
   
  Not exactly.  Se input to balanced output causes a differential gain of about 2%.
   
  Balanced input is much better for stax amps.


----------



## sachu

Highly recommend going either the TKD route or spring for the Penny and Giles RF15 or ALPS RK50.
   
  There is the KG attenuator as well if you can lay your hands on one which would work out to about $220-250 i believe.


----------



## sachu

Quote: 





gilency said:


> Victor, did you use the DACT for your KGSSHV?
> Anybody knows where to buy the quad penny & giles?


 
  Call them.
   
http://www.manquen.net/


----------



## spritzer

Quote: 





kevin gilmore said:


> Not exactly.  Se input to balanced output causes a differential gain of about 2%.
> 
> Balanced input is much better for stax amps.


 
   
  Just make sure that the source is actually balanced.  Way too many designers have used SE output stages with nasty opamp phase splitters to drive the balanced outputs.  This is also true of some very expensive gear...


----------



## HDMan

Quote: 





spritzer said:


> Just make sure that the source is actually balanced.  Way too many designers have used SE output stages with nasty opamp phase splitters to drive the balanced outputs.  This is also true of some very expensive gear...


 
   
  The Matrix uses a phase splitter, it's going up on ebay, ignorance was bliss.


----------



## HDMan

Got a refund on the Matrix, back to the original plan building the Buffalo Dac.
   
  Anybody know how good the Joshua Tree is? http://www.twistedpearaudio.com/control/jt.aspx
   
  And how well it would be with the KGSSHV.


----------



## kevin gilmore

joshua tree is very good.  Not constant impedance, which is just plain stupid.


----------



## johnwmclean

DACT installed, floors the Khozmo is every aspect.


----------



## gilency

Very nice. Would you mind posting a closer picture of the DACT connections and also the Stax jack?
I see you grounded your pot directly to the star ground.
Some people have recommended not to because the body is already grounded directly to the ground panel.


----------



## J-Pak

Nice clean build


----------



## johnwmclean

Thanks guys!
 Quote: 





gilency said:


> Very nice. Would you mind posting a closer picture of the DACT connections and also the Stax jack?
> I see you grounded your pot directly to the star ground.
> Some people have recommended not to because the body is already grounded directly to the ground panel.



  
 There’s really nothing in it, as both positions (star ground and the DACT body) have the same potential.


----------



## HDMan

Quote: 





kevin gilmore said:


> joshua tree is very good.  Not constant impedance, which is just plain stupid.


 
   
  So it's still good although it doesn't have constant impedance?


----------



## kevin gilmore

I like amb's thing better.
Both are going to be too big for your chassis.


----------



## Victor Chew

I know people that have given up their dact for the khozmo. I have never heard the Khozmo but was about to buy it but did not due to reading about its problems.. I have consequently gone back to buying the DACT.


----------



## johnwmclean

Victor from my discoveries on the weekend the DACT proved to be vastly superior. I can honestly say I hadn’t heard my KGSSHV until yesterday - it was a revelation.


----------



## HDMan

Quote: 





kevin gilmore said:


> I like amb's thing better.
> Both are going to be too big for your chassis.


 
   
Yes the AMB δ1 relay-based stereo R-2R attenuator looks nice. Especialy with a remote control and a LCD display 
	

	
	
		
		

		
			




   
   
  I could build it in it's own box, essentialy in between the source and the KGSSHV, kind of like a portable digital volume control?


----------



## sachu

Quote: 





johnwmclean said:


> Victor from my discoveries on the weekend the DACT proved to be vastly superior. I can honestly say I hadn’t heard my KGSSHV until yesterday - it was a revelation.


 
  Interesting. 
   
  I liked the Khozmo myself. BUt preferred the TKD over it. 
   
  I am considering springing for a RK50 or a P&G RF15 for my stat amp.


----------



## HDMan

Quote: 





victor chew said:


> I know people that have given up their dact for the khozmo. I have never heard the Khozmo but was about to buy it but did not due to reading about its problems.. I have consequently gone back to buying the DACT.


 
   
  I have not heard the DACT, but apart from the popping while turning the knob, it honestly sounds really good.


----------



## HDMan

I have been experiencing some strange background noise, almost like a slight hollow noise in quite scenes on movies, the noise goes away if the Khozmo is turned up to almost full volume and the DAC (or Realiser) is turned down.
   
  What kind of interference is this? Is there to much gain from the DAC, or is the Khozmo a superior Attenuator to the digital volume control in the Realiser?
   
  I also experienced this with the XLR outputs from the external DAC i had tried previously.


----------



## J-Pak

Quote: 





hdman said:


> I have been experiencing some strange background noise, almost like a slight hollow noise in quite scenes on movies, the noise goes away if the Khozmo is turned up to almost full volume and the DAC (or Realiser) is turned down.
> 
> What kind of interference is this? Is there to much gain from the DAC, or is the Khozmo a superior Attenuator to the digital volume control in the Realiser?
> 
> I also experienced this with the XLR outputs from the external DAC i had tried previously.


 
   
  Sounds like a problem with the Khozmo to me? If the Khozmo is turned all the way up it is essentially going to no resistance or taking itself out of the signal path.


----------



## HDMan

Quote: 





j-pak said:


> Sounds like a problem with the Khozmo to me? If the Khozmo is turned all the way up it is essentially going to no resistance or taking itself out of the signal path.


 
   
  Would it be advisable to remove the Khozmo and connect the inputs directly to the channel board for testing purposes?
   
  or
   
  Use not Pot at all?


----------



## johnwmclean

Quote: 





hdman said:


> I have been experiencing some strange background noise, almost like a slight hollow noise in quite scenes on movies, the noise goes away if the Khozmo is turned up to almost full volume and the DAC (or Realiser) is turned down.
> 
> What kind of interference is this? Is there to much gain from the DAC, or is the Khozmo a superior Attenuator to the digital volume control in the Realiser?
> 
> I also experienced this with the XLR outputs from the external DAC i had tried previously.


 
   
  Try bypassing the attenuator completely and see if you can hear noise with no input connected. 
   
  I’m hedging my bets on Khozmo as being the culprit, I did this with my build I found the Khozmo was exceedingly noisy.


----------



## johnwmclean

Quote: 





hdman said:


> Would it be advisable to remove the Khozmo and connect the inputs directly to the channel board for testing purposes?
> 
> or
> 
> Use not Pot at all?


 
   
   
  Shouldn’t be a problem,


----------



## HDMan

Quote: 





johnwmclean said:


> Try bypassing the attenuator completely and see if you can hear noise with no input connected.
> 
> I’m hedging my bets on Khozmo as being the culprit, I did this with my build I found the Khozmo was exceedingly noisy.


 
   
  Ok, I'll try it out, really wish the Khozmo was not hyped up so much, a more well known supplier would have been preferable.


----------



## johnwmclean

[size=12.0px]It’s probably a good idea to short the inputs out when testing without a pot. [/size]


----------



## HDMan

Quote: 





johnwmclean said:


> [size=12.0px]It’s probably a good idea to short the inputs out when testing without a pot. [/size]


 
   
  Your going to have to explain in simple terms for this noobie


----------



## johnwmclean

Quote: 





hdman said:


> Your going to have to explain in simple terms for this noobie


 
   
  Simple. Connect ground and +/- inputs together ie shorted, this in effect is the same as having a connected volume pot turned all the way down.


----------



## HDMan

I already tested it, works good, sounds good, but there is interference from the Transformer, is there anyway to counteract this without building a seperate power supply box?
   
  Mumetal casing are expensive?


----------



## kevin gilmore

Its balanced.  The + input and the - input should both go to ground.
  There are 500k resistors on board that do this, but the noise would
  be much higher if the inputs are not tied to ground.


----------



## HDMan

Quote: 





kevin gilmore said:


> Its balanced.  The + input and the - input should both go to ground.
> There are 500k resistors on board that do this, but the noise would
> be much higher if the inputs are not tied to ground.


 
   
  Grounding is ok, there is static like noise, it is quite though not loud. Yes the transformer noise is cut out when signal is passsing through, ground is taking effect.
   
  Does this design use caps to eliminate DC offset noise from the inputs, or is that what the offset pot is for?
   
  EDIT:
   
  Switched RCA cables, static noise is gone. My RCA cables were not shielded.


----------



## spritzer

Just for the sake of clarity, the KGSSHV is fully DC coupled so the offset pot is there to trim the DC offset at the output.  Unlike dynamic transducers, excessive DC voltage will not destroy electrostatic drivers but it should be kept as low as it possible.


----------



## HDMan

Want to buy my Khozmo for cheap? I am building the AMB instead.
   
  http://www.head-fi.org/t/613653/khozmo-quad-attenuator


----------



## gilency

.


----------



## gilency

Well, Khozmo reimbursed me my money on their defective pot, no questions asked.
 I was within 45 days of my Pay Pal purchase however and when he did not return my emails I opened a dispute.
 He still did not answer and I escalated to a claim.
 A few days later I got my money back.
 The Goldpoint works great and I am quite content with the number of steps. With iTunes volume all the way up I then use the attenuator to control volume. No hum or hiss. 

Correction: there is noise with the attenuator all the way down, only in the first step. Not sure yet how to fix that since without grounding the pot I was unable to control the volume.
From step 2 to 23 is a noise free as it gets.


----------



## HDMan

Quote: 





gilency said:


> Correction: there is noise with the attenuator all the way down, only in the first step. Not sure yet how to fix that since without grounding the pot I was unable to control the volume.
> From step 2 to 23 is a noise free as it gets.


 
   
  I had the same problem at step 1, I fixed it by following Justin's instructions on another forum.
   

 "XLR pin 1 should not be connected to star ground,  it should be connected to the chassis through the shortest path possible.  how you connect the chassis to circuit ground elsewhere is another story.

 as for the metal body of the attenuator, i would have it conduct to the chassis and dont try to wire it anywhere."
   
  So I grounded the XRL pin 1 to the XLR mounting screw, took the Khozmo star ground out of the loop and it is grounded directly by touching the chassis. This has worked for me, no more noise at zero volume and as quite as a mouse, completely black background even at full volume.


----------



## gilency

You meant Justin, right?
  Thanks, I am planning on fixing it over the weekend.
  My attenuator won't work without the ground leads connected though. Already tried that.


----------



## HDMan

Quote: 





gilency said:


> You meant Justin, right?
> Thanks, I am planning on fixing it over the weekend.
> My attenuator won't work without the ground leads connected though. Already tried that.


 
   
  LOL, yeh Justin.


----------



## gilency

My transformer (SumR) began buzzing. The amp is otherwise working great.
  I rechecked to make sure is well tightened to the chassis.
  Is this a potential problem I should worry about?


----------



## johnwmclean

Are you using an SSR?


----------



## gilency

I am using the relay [size=9pt]G8P-1A2T-F-DC12[/size]


----------



## johnwmclean

I had a problem with a 25A ssr the transformer had a loud 50hz buzz, I switched to a 40A unit and the buzz instantly ceased.
   
  http://relays.te.com/appnotes/app_pdfs/13c3206.pdf


----------



## gilency

Even with the transformer removed and connected directly it still buzzes though.


----------



## johnwmclean

1/2 wave halogen dimmers will cause dc in the line. Same with florescent lights. Switching power supplies on the same line as the audio transformer can cause dc disturbance.


----------



## gilency

Thanks. The buzz is now gone. I am not sure where the interference came from


----------



## kevin gilmore

El-cheapo lamp dimmers are some of the most evil devices you can imagine. The noise they
  can put on the AC line is just amazing.
   
  Buy the high end lutron dimmers.  Back to back mosfets, full wave, microprocessor controlled
  and automatically adjust for forward or reverse phase control when driving high voltage led's
  and other nasty loads.
   
  Every single dimmer in my house got upgraded to RA2 and have not had any interference
  problems since. There are non RA2 versions that are exactly the same thing.


----------



## gilency

Well, it is the game room's light.
  My son was playing XBox with the room lights dimmed.
  Easily reproduced, and easily fixed!


----------



## jaycalgary

I started gathering more parts for my build. I figured the case I built wouldn't be up to snuff for time and effort this is working out to be. I was about to pull the pin on one at this Siliconray site but for some reason they like to ask you to pay shipping twice and not even by mistake. The nice one was about $300 all together and a perfect size. After spending ridiculous amount of time on the web looking for a nice case I ended up rolling the dice on a game from this site
  Hiendking.com. At a grand total of $169 I took a blind chance that it is big enough and I will actually get it. The faceplate looks like one of the nicest off the shelf enclosures out there.  http://hiendking.com/studio-300-height-120-depth-breeze-aluminum-chassis-p-3551.html    
  Does it look like it will be big enough if you had to guess?


----------



## johnwmclean

If its 120mm height, I’d say proportionally its very similar to the Modushop 3U 400mm case which is a perfect size.
  Pity the site lacks a detailed description of any kind 
	

	
	
		
		

		
			





.


----------



## headinclouds

Is anyone building the KGSSHV? -  Yes there are new builders coming forward.  I have also been enthused by these posts.  Thanks to all for sharing your experiences.  
  My build is getting into its stride  - I have most of the parts now.  I am just about to buy pcbs for the onboard heatsink version - if anyone wants to join in and order a set please pm me.
   
  PEEK screws- does any one have  6 or so for the heatsink which they would be willing to sell me please?


----------



## justin w.

headinclouds said:


> Is anyone building the KGSSHV? -  Yes there are new builders coming forward.  I have also been enthused by these posts.  Thanks to all for sharing your experiences.
> My build is getting into its stride  - I have most of the parts now.  I am just about to buy pcbs for the onboard heatsink version - if anyone wants to join in and order a set please pm me.
> 
> PEEK screws- does any one have  6 or so for the heatsink which they would be willing to sell me please?




Send me a PM, i have the screws


Sent from my iPhone using Tapatalk


----------



## headinclouds

Thank you Justin that's great.  PM sent


----------



## headinclouds

Screws arrived thanks Justin.  I have nearly all the parts now.  Really looking forward to building my KGSSHV. 
   
  Just about to order circuit boards.  Last call for anyone who wants a set!


----------



## jgazal

Quote: 





el_doug said:


> lol ty - sorry I don't have much else to show right now, as far as the power supply goes.  I did go out of my way to make the thing safer by using a female dc power connector on the PSU, and a male one on the amplifier


 
   
  What changes are necessary when the power supply is positioned in other case and connected with umbilical cords? Adding any capacitors or resistors? Adding low voltage power supplies inside the amplifier case?


----------



## spritzer

None really, just keep the umbilical as short as is possible.


----------



## headinclouds

I’ve finished my KGSShv and have at last been able to listen to my SR-507.  The amp has run for 10 hours so far and I have listened to it for the latter couple of those.  It’s certainly working well.  I have heard some beautiful music already.  Thanks to members who so kindly helped with advice and offers to supply parts.   It’s been an enjoyable build.
  After the dust settles on this I might do another, in a different format.


----------



## AnakChan

Quote: 





headinclouds said:


> I’ve finished my KGSShv and have at last been able to listen to my SR-507.  The amp has run for 10 hours so far and I have listened to it for the latter couple of those.  It’s certainly working well.  I have heard some beautiful music already.  Thanks to members who so kindly helped with advice and offers to supply parts.   It’s been an enjoyable build.
> After the dust settles on this I might do another, in a different format.


 
   
  Nicely done! If I may ask, what are the measurements of the case?


----------



## headinclouds

Hi AnakChan!
   
  Thank you, I am pleased with the way it has turned out.  Credit to the designer as it goes together well and works!
   
   
  The case is 435 wide by 400 deep 2U high.  The front panel is 450 x 90 x10. From the Modushop range.


----------



## AnakChan

Quote: 





headinclouds said:


> Hi AnakChan!
> 
> Thank you, I am pleased with the way it has turned out.  Credit to the designer as it goes together well and works!
> 
> ...


 
   
  Thank you. I'm waiting for my boards at the moment, thx to Lil' Knight and to AlwaysHungry and will be pinging them for help during the build. I hope you don't mind if I pop a few questions your way over the next few months when I get my kit.
   
  I'll check out Modushop now (& when I get home will pull out the tape measure). I don't have a lot of space and therefore trying to see various build designs. Unfortunately, I've only heard of (Kevin's??) smallest KGSSHV but never seen pix.


----------



## spritzer

The smallest KGSSHV in existence was built by me and this one uses the same chassis.  No way to cram these boards into a smaller chassis than 480*400mm...   
   
  I've already drawn up smaller offboard PCB's and a new PSU so a very small HV is in the cards...


----------



## headinclouds

That's right Spritzer, the picture of yours was the inspiration for mine as it was clear it would all fit in.


----------



## AnakChan

Thx to Lil' Knight on the board run. Just received them tonight.


----------



## Anthony1

Ok Temporaryname and I have secured some boards from Lil'Knight (thanks Lil'Knight) but something tells me that was the easiest part. Looking for any resources/links on the build if anybody has any.


----------



## spritzer

Google KGSSHV...


----------



## AnakChan

Just seeking advice, has anyone used the TKD 4CP-2508-S for their KGSSHV? How would they compare against the RK27 or RK50?


----------



## sachu

That's a good pot in my book. Smooth. I liked it better than the DACT attenuator and way better than an RK27.


----------



## Lil' Knight

anakchan said:


> Just seeking advice, has anyone used the TKD 4CP-2508-S for their KGSSHV? How would they compare against the RK27 or RK50?



If you ever buy it, Sean, please squeeze a couple for me  Don't know what to do with them but they are one of the quad attenuators that I still haven't tried.


----------



## NoPants

Quote: 





lil' knight said:


> If you ever buy it, Sean, please squeeze a couple for me
> 
> 
> 
> ...


 
  On that note, does anyone know where to get these in the States? I've only seen the dual stepped pots (2508)...I was about to pull the trigger on 2 of these for my next build.


----------



## Pars

I've never seen them in the US. Percy Audio, Partsconnexion both handle TKD, but stereo only. A german vendor does have the quads:
   
http://www.thel-audioworld.de/bauteile/regler/Potis.htm
   
  I'd agree that these are better than RK27s, but not as good as an RK50 (but then they don't cost ~1K either). Penny and Giles is another one you could look at, though I've heard their pricing has gone up to near RK50 levels.


----------



## NoPants

Thanks for the heads up! It's hard to stomach that price stateside too- makes me feel like I should drop for either 2 stereo pots or the RK50- go big / go home etc. etc.
   
  And so I go'd big: http://www.ebay.com/itm/221260665389?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
   
  I'm kind of regretting it right now though...guess this means I'd better build that T2?


----------



## paradoxper

Finding a reliable builder for the KGSShv can be a challenge. Especially considering
 the likes of Fishski won’t touch HV or Tran who is just too busy. So I had to search out for alternatives.
  
 I stumbled across Headincloud’s listing for his on-board, inquired about the possibility
 of shipping overseas, but was informed it was no longer available. Just my luck, right.
 Well, Geoff had other ideas and thus began our journey.

  
 Initially Geoff had drawn up a proven design, which was simple and reliable,
 but I had other ideas. More than willing to give it a shot we came up with a design 
 with a smart look, completely inspired by Headamp’s current offerings. 
  

  
  
 An all aluminum off-board w/servo. Polished front and top panel with the A-D 41-step attenuator.
  





 Being a DIY project there was much risk doing the metal work, luckily, it turned out really great. Thanks to Justin for sharing his knowledge and experience in dealing with the metal. Learned a good deal and can fully appreciate how difficult it is to get Headamp quality.
  
 Thanks to Geoff for putting up with my schiit, being flexible and getting things done right. I was rather lucky to find such a good builder and an utter gentleman. 
  
 Hope you guys enjoy the pics, this was definitely a fun process.
  
  
 And yea, it sounds  damn great.


----------



## mikek200

Hi Para,
  
 Excellent impressions,and glad you are more then satisfied
 Pics are excellent
 I know the wait was long,but,now,you are Endgame--RIGHT-lol
 Use it in Good Health,
  
 Mike


----------



## dailydoseofdaly

Gorgeous congrats Para


----------



## Radio_head

paradoxper said:


>


 
 Wow, that is quite a looker.  Congrats.


----------



## paradoxper

Thanks dudes.


----------



## MacedonianHero

Most excellent looking amp! Your SR-007s should be really singing now with that amp!


----------



## gilency

Welcome to the Kevin Gilmore's club. A very exclusive one may I add!


----------



## paradoxper

gilency said:


> Welcome to the Kevin Gilmore's club. A very exclusive one may I add!


 
 As my builder has said 'without Kevin Gilmore we'd be no where.' Proud to own one of his designs.


----------



## headinclouds

Thank you paradoxper for that excellent write up and your kind words. – I never thought my cardboard mock ups would be online!
 The KGSShv does not seem to get the attention it deserves here in UK/Europe.
 Perhaps it’s because there are few around so you cannot easily see or hear one.
 You have to have some experience and confidence to build a high voltage stat amp, but I have found it works as intended if built carefully.
 Dr Gilmore has given us an excellent circuit design and although not inexpensive it is a taste of the high end.
 I have found it to be superior to all systems I have had before when used with Stax SR-007.


----------



## gilency

I have built 2 KGSSHVs having had minimal experience in electronics before.
 They were my first real builds, besides a couple of Cmoys and cross feeds, and although they were not exactly easy, if you are careful soldering and think and plan your build, you will be rewarded with wonderful sound.
 The DIY community here at head-fi is shrinking, and that is a real shame. I encourage everybody to try, start small and move into more complex projects as you become more experienced.
 It beats buying commercial stuff anytime.


----------



## headinclouds

Yes,  thanks for that encouragement, there is also plenty of advice and help from the h-c community.  Gilency very kindly sent me a summary of advice and tips when I did my first.
  
 Off to London to deliver negura's now!


----------



## negura

My KGSSHV is finally here! So many thanks to headsinclouds for the excellent build. This is an off-board, 1800V, 10mA build.
  
 I also had the chance to compare 4 Stax headphones with it today: Early 007 MK1s, Later 007 SZ1 MK1, 007 MK2 and 507. This was with some very interesting and unexpected impressions in regards to the headphones. 
  
 I will post some pics shortly, but first impressions are very pleasing. For now all I will say is one better like the sound of their DAC.


----------



## paradoxper

Lovin' it!
 Geoff, hurry up and get that cube-build built, so we can have the trifecta.


----------



## headinclouds

It should be a dead heat for sound quality, but if you're angling for a beauty competition, behave.


----------



## paradoxper

headinclouds said:


> It should be a dead heat for sound quality, but if you're angling for a beauty competition, behave.


 
 Everyone knows the silver sounds cleaner.


----------



## Plokhikh

Dear friends,
  
 Could you tell me, please, how much dose KGSSHV DIY parts cost? And where I can buy it all in one in USA? Thank you very much!


----------



## NoPants

1k dependent on casing
  
 mouser


----------



## Plokhikh

And where I can buy this?


----------



## NoPants

mouser
  
 http://tee8tee4388.blogspot.com/2013/07/kgsshv-amplifier.html


----------



## Plokhikh

Is it (mouser) the nickname of the person who sells KGSSHV DIY parts?


----------



## arnaud

plokhikh said:


> Is it (mouser) the nickname of the person who sells KGSSHV DIY parts?




It's hard to guess from the above, but this might be your first diy project, isn't it?

A bit of caution may be in order before you eletrocute yourself with this, please read read amd read even more before you run with this.

Arnaud


----------



## Plokhikh

Yes it is my first DIY project. I have got a good friend who can help me with it. He can solder it, but we need a parts.


----------



## arnaud

Maybe your friend knows mouser then, lol .


----------



## Plokhikh

Mouser electronics?=)


----------



## NoPants

I suggest your friend take a look at the link I posted instead of you playing the intermediary role


----------



## paradoxper

You might want to consider the 'other place.' They're much more informative than these parts and
 generally updated more often as well. Do take caution in buying from the 'right' places,' there's lots of fake parts out there.
  
 Lastly, just don't die. Take your time and be careful.


----------



## NoPants

This is more an issue with everything that isn't the KGSSHV, all the parts for the modern version are now sold by mr mouser. the IXYS parts are expensive but that's really about it. technically you don't even need to case the thing if you give it a good spray of conformal coating if you are cheap


----------



## paradoxper

nopants said:


> This is more an issue with everything that isn't the KGSSHV, all the parts for the modern version are now sold by mr mouser. the IXYS parts are expensive but that's really about it. technically you don't even need to case the thing if you give it a good spray of conformal coating if you are cheap


 
 Good point. It wasn't clear at all which version he was going for, so for, say, the 1968 parts this might change things. I know at the time there was a little trouble in sourcing some  2sc4686a's. Bdent worked out though. Just something to consider.


----------



## AnakChan

paradoxper said:


> Good point. It wasn't clear at all which version he was going for, so for, say, the 1968 parts this might change things. I know at the time there was a little trouble in sourcing some  2sc4686a's. Bdent worked out though. Just something to consider.


 
  
 I may have missed this but where is the 2SC4686A used (I don't see them in the BOM) and what's the benefit of it? The reason is that I still can access the 2SC4686A in Japan.


----------



## NoPants

the 2sc4686 are the original output devices used before the "modernization", my guess is less cap than the ixtd* part


----------



## paradoxper

anakchan said:


> I may have missed this but where is the 2SC4686A used (I don't see them in the BOM) and what's the benefit of it? The reason is that I still can access the 2SC4686A in Japan.


 
 As NoPants noted they're the original output devices. The 'benefit' is a supposed sweeter sound.


----------



## AnakChan

paradoxper said:


> As NoPants noted they're the original output devices. The 'benefit' is a supposed sweeter sound.


 
  
 Gotcha. I have last year's on and off-boards and also jumped onto the KGSSHvk boards which came out in Sept/Oct. I guess none of them would be able to leverage on the 2SC4686A?
  
 Sadly more than 1 year has passed and despite having bought the boards, and transistors from Sato Denki, I've not progressed in my build.


----------



## NoPants

they should work, iirc there are spots for both isolated and exposed-tab devices. even if there aren't just bend the legs to make it work. spritzer has given the blessing on the IXYS "sound" though
  
 I'm jealous, you get some good prices on those active devices.
  
 What's stopping you from finishing? It's fairly straightforward before casework, the KGSSHVk moreso than the others.


----------



## paradoxper

anakchan said:


> Gotcha. I have last year's on and off-boards and also jumped onto the KGSSHvk boards which came out in Sept/Oct. I guess none of them would be able to leverage on the 2SC4686A?
> 
> Sadly more than 1 year has passed and despite having bought the boards, and transistors from Sato Denki, I've not progressed in my build.


 
 Brain fart. I was referring to the 2sa1968 being sweeter sounding. 
  
 You can use either. I don't personally think there's a big difference with the IXY's over the 'older parts'. More drift, but that isn't really a problem.


----------



## AnakChan

To be honest, work, laziness & family responsibilities. I haven't bought any of the other components aside from the transistors & a Tkd 4CP-2508-S pot (although I do still want to order the RK50).

I may make an order with Sato Denki for the 2SC4686A. PM me if you want some. Can ship it to you when it arrives - usual PP & shipping fees.


----------



## NoPants

I've been wanting to try out that TKD pot. Did you source it from a European shop? I've forgotten.
 I would suggest saving an rk50 for something like the BHSE/megatron/T2. That way, the power consumption will be as obscene as the pot price.
  
 Thanks for your generous offer, but I bought a little bit over double what I needed for my first KGSSHV build. I have those leftovers and a set of IXYS for the -k boards which I've also left sitting around for a few months.
  
 I may hit you up for some T2-related parts though...this hobby is the worst


----------



## AnakChan

There is an annual tube festival/event in Japan (which is usually overshadowed by the big Fujiya/e-earphone Headphone, and International Speaker events) and they sold parts there. I bought the TKD from one of the exhibitors there. I also bought some Allen Bradley resistors only to realise the tolerance was the wrong spec 
	

	
	
		
		

		
			





(10%).
  
 I know what you mean about going overboard. I ended up buying like 5x of transistors & boards (3x on, 2x off).


----------



## chinsettawong

anakchan said:


> I know what you mean about going overboard. I ended up buying like 5x of transistors & boards (3x on, 2x off).


 
  
 I think that's very normal for an active DIYer.


----------



## negura

Ok my story. It's been a while since I received my build of the KGSSHV. Built by headinclouds it was an offboard 10mA 1800V. It was a exceptional experience working with Geoff (headinclouds) to get this build completed to my requirement. To the standard build we have added a 41 steps attenuator (credit to paradoxper for the idea) and Furutech XLR and mains sockets. Whether or not the later made any difference I don't know, but they seem to be quality built.
  
 I had a good impression on the KGSSHV sound on my own headphones from previous listening. The initial impression after burn-in was right on par with my original experience. The KGSSHV is an amazing technically sounding amplifier, with great PRAT, detail and speed. However, having heard a few things here and there, I told Geoff something was yet missing. Yes I admit, I am a bit of an ass, I was so lucky in the first place to have found someone to build me a top spec KGSSHV and to my specific requirement.
  
 So here's where the story goes a few months later. A few modifications, and most importantly since we have some good cooling capacity here, a 14mA current KGSSHV. 
  
 I was expecting an improvement I will admit to that. It only has a couple of days burn-in, but I only needed about a few seconds to tell this is now a completely different animal. Before posting complete impressions I would like to allow it to settle to a complete run-in, but it is the best I have ever heard the Stax headphones yet. Organic, effortless, holographic, yet very detailed and fast. That thing that made the KGSSHV just a bit sterile is completely gone now.


----------



## arnaud

Wow, 14mA, that's 3x the nominal value recommended for the build?
You're in DIY T2 territory as far as voltage swing and idle current goes, this thing must be fairly huge and run pretty warm!

Would be curious to hear more about perceived differences beween the 2 versions you heard. What phones are you using?

Voltage swing ratings: http://www.head-fi.org/t/582518/electrostatic-amplifiers-voltage-ratings/0_30#post_7924572

Current ratings: http://www.head-fi.org/t/582518/electrostatic-amplifiers-voltage-ratings/0_30#post_7925458


----------



## negura

Yes, we are probably in previously uncharted territory here. I own the SR-007 MKIs and 009s. My impressions are on the 007 MKIs as these are much harder to drive. I am a simple guy who thinks the 009s actually can run and sound great on a lot of lesser amping. Of course "better" still does it. 
  
 The 14mA KGSSHV is running at a constant 38-39 degrees Celsius with 21-22 degrees room temp. Compared to my tractor class A speaker amp which runs at constant 57-59 degrees and keeps my room warm in the winter at a constant 22 degree, with no other heating, this is a walk in the park.
  
 Regarding perceived difference: The KGSSHV was really great, but this is sounding as a completely different class now. I'm loving it, gets me foot tapping on every genre I've heard so far. It's 3 am here yet I am still re-discovering music. Even metal music is sounding both bad ass and clear and this is a busy genre, yet it sounds effortless. Also the bass response... my god. The KGSSHV always had excellent bass response, but this is yet another level in impact. It's thundering and exploding. Gives these stators a run for their money for sure.  And no, it doesn't change the frequency balance, it's just that bit better in transient response.


----------



## Argybargy

Very interesting! Were the mods substantial enough that a bigger case was needed?


----------



## negura

argybargy said:


> Very interesting! Were the mods substantial enough that a bigger case was needed?


 
  
 No case change.


----------



## gilency

KGSSHV does not sound sterile. At all.


----------



## headinclouds

The case measures 380 W x320 D x100 H, plus a 10mm front panel of 382 x 102.  Edit for the non-metrics (15" W x 12" deep x 4" high) plus feet
 This is it;


----------



## Crashem

Interested in hearing what mods were done. Don't keep us in the dark.

Also, headinclouds, did you do the mods?


----------



## headinclouds

It is very easy to increase the output stage bias as long as you can get rid of the heat.  Change the resistors values that set the bias to less than 100ohm and you're above 10mA.
  
 This is all covered on the other site.


----------



## negura

gilency said:


> KGSSHV does not sound sterile. At all.


 
  
 By that I mean a bit digital sounding. This is compared to the "upgraded" one, which I think sounds that bit more organic and at ease. Also in comparison I think it sounds less grainy and more fluid in the high frequencies.


----------



## gilency

it doesnt sound digital either


----------



## negura

It's very good you are finding it that way. I liked the original KGSSHV, a lot, but not completely. It was great, but I am pleased it could be improved to a net effect to the sound quality I am hearing. And foremost credit goes to the amazing and scalable design we have from KG and I feel on this iteration I will be struggling to find minuses. Well that is until I hear something even better I guess.


----------



## spritzer

These claims of a massive improvement with an increase in current in no way correlate to the data at hand or my own experience.  The circuit is completely linear down to about 2mA (or even slightly less) and we chose 5.5mA as there was no way to make the amp clip and it worked at +/-500V off of onboard heatsinks.  I've gone way past 14mA in testing and the change is subtle at best so by definition there is something horribly wrong if the amp magically gets better by leaps and bounds simply by running it harder.


----------



## paradoxper

negura said:


> Ok my story. It's been a while since I received my build of the KGSSHV. Built by headinclouds it was an offboard 10mA 1800V. It was a exceptional experience working with Geoff (headinclouds) to get this build completed to my requirement. To the standard build we have added a 41 steps attenuator (credit to paradoxper for the idea) and Furutech XLR and mains sockets. Whether or not the later made any difference I don't know, but they seem to be quality built.
> 
> I had a good impression on the KGSSHV sound on my own headphones from previous listening. The initial impression after burn-in was right on par with my original experience. The KGSSHV is an amazing technically sounding amplifier, with great PRAT, detail and speed. However, having heard a few things here and there, I told Geoff something was yet missing. Yes I admit, I am a bit of an ass, I was so lucky in the first place to have found someone to build me a top spec KGSSHV and to my specific requirement.
> 
> ...


 
 What were the few modifications? Just doesn't seem like blasting the output is going to yield these significant changes alone. Though I guess we all hear differently
 this just doesn't add up.


----------



## NoPants

In general upping the current seems to work primarily on the high end, making everything less fatiguing to listen to for long periods of time. This is the main difference I've noticed between a Megatron and offboard KGSSHV, and other differences are mostly in presentation.


----------



## paradoxper

Uh, yea, I guess Negura could have found the HV fatiguing. I spoke to someone who has gone way past 14mA and confirmed it's a subtle change.


----------



## negura

nopants said:


> In general upping the current seems to work primarily on the high end, making everything less fatiguing to listen to for long periods of time. This is the main difference I've noticed between a Megatron and offboard KGSSHV, and other differences are mostly in presentation.


 
  
 Yup. That's exactly what I noticed regarding the high-end of the spectrum. No longer the SR-007s are trying to sound as slightly something else, but I guess this is also a matter of preference. They sound determined, defined, energetic, but organic and sweet. Yet they sound more transparent and life like. Do I like the SR-007s better than before? Hell yeah, but that's me.
  
 Exactly for this reason now the other good news: the KGSSHV will also better match with the SR-009s. Again imo.
  
 The KGSSHV + SR007s was in no way fatiguing. It just sounds better now. In regards to your other question Cory: To get a final tune on the sound I think people should feel free experimenting with resistors, if they can, and this is as much as I want to comment on this, because this is both controversial and very much down to preference, and not a single blanket suits all. Not going to get into any arguments on this topic.


----------



## preproman

Was having a similar build done and was going to bias it as high as the builder would let me, was going to use the RK50 pot and lots of upgraded parts.  The builder called it the KGSSHV-DX.......The DX stands for Deluxe as the enclosure was going to be custom made.
  
 This is the closest I got to my amp being built -->
  

  
  
 I got ripped off by none other than *Lil Knight* himself - in the amount of $4K  Where the heck is my amp?
  
 So I've gone forward and purchased the BHSE.  That was my SR-009 money...


----------



## negura

That is so not cool. I was also recently ripped off in audio, fortunately for me for a much lesser amount, but I know how it feels like. I also happen to have heard mentions of other people in the same situation as you with the same builder.
  
 I'm sure you would've been very pleased with a unique KGSSHV like that, but the BHSE is you know... the benchmark. And there's nothing anywhere close to that look and feel.


----------



## MacedonianHero

spritzer said:


> These claims of a massive improvement with an increase in current in no way correlate to the data at hand or my own experience.  The circuit is completely linear down to about 2mA (or even slightly less) and we chose 5.5mA as there was no way to make the amp clip and it worked at +/-500V off of onboard heatsinks.  I've gone way past 14mA in testing and the change is subtle at best so by definition there is something horribly wrong if the amp magically gets better by leaps and bounds simply by running it harder.


 
 Thanks Birgir....kinda what I expected. Interesting, I didn't realize that the 450V version could go as high as 14mA (mine is set to 9-10mA).


----------



## paradoxper

preproman said:


> Was having a similar build done and was going to bias it as high as the builder would let me, was going to use the RK50 pot and lots of upgraded parts.  The builder called it the KGSSHV-DX.......The DX stands for Deluxe as the enclosure was going to be custom made.
> 
> This is the closest I got to my amp being built -->
> 
> ...


 
 Over at the other place it was confirmed that Tran ran into some issues with his CNC guy. Though his communication stinks don't lose all hope just yet.


----------



## paradoxper

macedonianhero said:


> Thanks Birgir....kinda what I expected. Interesting, I didn't realize that the 450V version could go as high as 14mA (mine is set to 9-10mA).


 
 Yup. Birgir told me the same thing.


----------



## spritzer

macedonianhero said:


> Thanks Birgir....kinda what I expected. Interesting, I didn't realize that the 450V version could go as high as 14mA (mine is set to 9-10mA).


 
  
 IXYS or Sanyo only applies to the third stage CCS.  It's not really a good idea to mess with the current setting on that one so what we alter is the output stage standing power.


----------



## gilency

Exaggerations in sound improvement are not usually made by the DIY crowd.
 I listen to the KGSSHV pretty much nightly and it sounds just great. Neither sterile nor digital or strident comes to mind.
 Can't wait for the Megatron build so I can compare.
 Building them is as much fun as listening....


----------



## headinclouds

There is some speculation on what caused the change to negura’s enjoyment of his KGSShv.  When I made it for him I used  the same circuit components, circuit boards and wiring types as the other three of this design I have built.  (Except at his request it had Furutech IEC socket and xlr connectors.)  It  sounded effectively  the same and  was running at the same nominal 450v and 10mA. 
 negura asked if I had any ideas to squeeze a bit more out of it and the mix now includes metal film and tantalum film resistor types, the bias current has been increased to 14mA. The tantalum film resistors are used in the feedback and output of the amp.
 When it was first powered up I was surprised that it seemed to be so different.  It was bright and revealing of detail.  The sound changes as the circuit runs in.   The amp seems very musically engaging to me also.


----------



## Radio_head

preproman said:


> Was having a similar build done and was going to bias it as high as the builder would let me, was going to use the RK50 pot and lots of upgraded parts.  The builder called it the KGSSHV-DX.......The DX stands for Deluxe as the enclosure was going to be custom made.
> 
> This is the closest I got to my amp being built -->
> 
> ...


 
 I would certainly hope that's not the case, as he currently has thousands of other peoples money tied up in T2 casework.  Last I heard he was waiting for the Chinese new year to pass so he could get some work done...


----------



## spritzer

Given that the RN60D metal film resistor is just about the perfect resistor then "upgrading" them can only be detrimental.  There are exceptions such as the "batteries" in the T2DIY which need a slightly inductive resistor (and Stax told us as much) but that isn't the case here.


----------



## preproman

radio_head said:


> I would certainly hope that's not the case, as he currently has thousands of other peoples money tied up in T2 casework.  Last I heard he was waiting for the Chinese new year to pass so he could get some work done...





 I sure hope not. 
  
 He has yet to return any of my emails or PMs this year.  He stopped returning my PMs in Sept. 2013.  The last email I got from him was from Dec. 15th of 2013 saying his hometown got hit with a Typhoon and flood and promised the amp by the end of the year.  After that - nothing no more emails no more PMs - nothing.  
  
 We started this project in May of 2013.


----------



## Radio_head

That sucks.  When he was in the US a few years back (lived near you in OH actually) he was very easy to get hold of but since he's been out east, its been hard to get in touch with him in general.  Hope you get that resolved, its a great amp.


----------



## preproman

Yeah, it was going to be a special build.  At this point I'd rather take a new / mint condition pair of SR-009s.


----------



## negura

I am loving it and I am very confident of what I am hearing. The upgrades I am finding very significant to SQ. It also helped me personally understand what some criticize about the vanilla KGSSHV sound. My 2c anyone can feel free to disregard and disagree with.

Again many thanks to KG for such a great design and headinclouds for the excellent build!


----------



## paradoxper

I'll take Birgir's absolute experience and knowledge over anything else. But I am glad you found even more enjoyment with your amp, Neg. After all, this hobby is subjective.


----------



## Radio_head

+1.  His knowledge and experience is simply absolute.


----------



## paradoxper

radio_head said:


> +1.  His knowledge and experience is simply absolute.


 
 I ran straight into that one.


----------



## kevin gilmore

On the T2, the high end Vishay resistors caused a problem because they leaked current to the ground plane.
 Due to the super thin coating on these resistors. So running a resistor at 500v ( a few at 560v) for a resistor
 rated at 350v did not turn out well. Lifting the resistors .25 inch above the board did help, but still not
 a great idea. Stax used xicon resistors rated for voltage for a reason. And the same resistors are
 highly recommended if you build a diy T2.
  
 I can definitely see that if you change the feedback resistors to something like a non-inductive bulk film type
 the sound is going to change. The standard dale 1% rn60 resistors are all spiral trimmed to value and
 are therefore slightly inductive, and the inductance changes with the value.
  
 I have found that the absolute best resistors for this are the thick film on ceramic substrate. But they
 are very fragile (crack easily if you overheat when you solder) and 150 times the price of regular resistors.
  
 One of the nice things about DIY is that you can customize just about everything. Like using the
 way overpriced RK50 pots. And silver wire.


----------



## headinclouds

Yes technical requirements come before audiophile fads.  I am not a believer in just throwing money at a project, preferring to get the best result from engineering means.  Starting with a reliable circuit and BOM etc. that sounds really good in stock form, build changes can alter the flavour a little.  Careful selection of component types allows fine tuning of the sound.  Because electrostatic and valve amplifiers involve high voltages we are limited in suitable resistors.  Within that narrow band there are a few resistors that can alter the sound.  I am sure other builders will try experiments of their own; as Kevin says that is one of the nice things about DIY.
 We also have the possibility of fitting the circuits into different personalised cases which is where DIY is really fun.  Some published pictures have shown quite different case types.
 I have built several in different styles, at the request of enthusiasts, so they could get close to their personal wants.  The most recent was built to take up least room on the desk.  Nicknamed the “Cube” it is gold with black trim.   It contains the mini PS, amps, servos and A-D attenuator in a size of 242 W x260 D x180H. It has 450v rails and 14mA standing current.  I am now building one for me to keep.


----------



## chinsettawong

That KGSSHV is a beauty!


----------



## headinclouds

Thanks chinsettawong,  You probably know as well there are times when you wonder what you've gotten into!
 But they turn out well in the end.
  
 P.S. I was admiring your estat phones again this week.  Now I've done a few amps I need to try something else!


----------



## paradoxper

That lil thing is pretty badass. I think we'd all like some desk/rackspace back. Nice work, Geoff!


----------



## headinclouds

Hi Cory,
  
 Glad you like it.  Hope you're still enjoying yours.


----------



## paradoxper

headinclouds said:


> Hi Cory,
> 
> Glad you like it.  Hope you're still enjoying yours.


 
 I am, er, uh, was. I have no headphones! Haha. SR-009 soon though.


----------



## headinclouds

Oh I see you've sold the 007 MkII.  Did you  hear the 009 with your KGSShv?  Perhaps you have posted about this elsewhere.


----------



## paradoxper

I did. I generally don't post impressions much, but I really enjoyed the 009 enough to make the move.


----------



## gilency

009 + KGSSHV = long nights of listening pleasure and sleep deprivation. Very pleasant and detailed. Not strident to my ears. The closest thing to being there.
Will report the differences when I finish the Megatron build.


----------



## Anthony1

headinclouds said:


>


 
 That is a sweet build headinclouds. What type of case is that may I ask?


----------



## HeadphoneAddict

gilency said:


> 009 + KGSSHV = long nights of listening pleasure and sleep deprivation. Very pleasant and detailed. Not strident to my ears. The closest thing to being there.
> Will report the differences when I finish the Megatron build.


 
  
 I know I will regret selling my SR-009 with hotrodded KGSS, as it's a wonderful combination.  But 2 kids in college is expensive and I'll have to be happy with KGBH + 007 and HE-60...  The HE-60 are very close to the 009, with just a little less fullness, warmth and bass than the 009.


----------



## headinclouds

anthony1 said:


> That is a sweet build headinclouds. What type of case is that may I ask?


 

 It is an aluminium case I designed and made.  It is the only way to get exactly what I want. After the metalwork was done I got it surface finished, anodised champagne gold colour and engraved.


----------



## Hun7er

headphoneaddict said:


> I know I will regret selling my SR-009 with hotrodded KGSS, as it's a wonderful combination.  But 2 kids in college is expensive and I'll have to be happy with KGBH + 007 and HE-60...  The HE-60 are very close to the 009, with just a little less fullness, warmth and bass than the 009.


 
  
 What differences between the SR007 and HE60 for you ?


----------



## paradoxper

gilency said:


> 009 + KGSSHV = long nights of listening pleasure and sleep deprivation. Very pleasant and detailed. Not strident to my ears. The closest thing to being there.
> Will report the differences when I finish the Megatron build.


 
 That should be an interesting comparison, surely. Is a T2 gonna make it to your workbench anytime soon?


----------



## gilency

Probably not. The Megatron really caught my eye and it has been a real fun built.
 Main reason for not going for the T2 is difficulty getting some parts, although if I can get me a board I might be tempted  though


----------



## HeadphoneAddict

hun7er said:


> What differences between the SR007 and HE60 for you ?




Those two headphones are so different from each other it would be easier to ask what are the similarities. And that would be speed. 

The Sennheiser have a much more ethereal, airy, and open sound, & it's more delicate and 3-D sounding. They have a fuller sounding mid range and more treble presence than bass presence. The HE-60 require a strong amplifier to extract strong bass impact, such as my 400v KGBH. 

The 007 have more bass impact & bloom, with a slightly recessed midrange that gives them more depth, & a balanced treble responses long as you have an amplifier that's strong enough to drive them. With a weak amplifier the 007 may sound a little bit dark, and lack bass impact as well (Woo GES). The 007 sound a little more laid-back and less energetic than the HE 60, but they became more energetic and less laid back with my previous KGSS. They are still slightly laid-back with the KGBH amplifier except that bass impact & power is greatly increased with it, and the mids still do not jump out at you. The HE-60 would be like a supercharged HD800, the 007 would be like a supercharged LCD-2.

[EDIT - I should add that the HE-60 has a little bit more mid range presence than HD 800, and does not sound as distant. Also the 007 has slightly less midrange presents than the LCD-2 so it's not as forward sounding.]


----------



## Hun7er

headphoneaddict said:


> Those two headphones are so different from each other it would be easier to ask what are the similarities. And that would be speed.
> 
> The Sennheiser have a much more ethereal, airy, and open sound, & it's more delicate and 3-D sounding. They have a fuller sounding mid range and more treble presence than bass presence. The HE-60 require a strong amplifier to extract strong bass impact, such as my 400v KGBH.
> 
> ...


 
  
 Thank you for your answer. I didn't hear the HE60 and SR007 on KGSSHV. But even on another amp my thinking is rather you even I found the HE60 not spacious as the HD800.
  
 http://www.innerfidelity.com/images/SennhheiserHE60.pdf is not as flat as the HD800 http://www.innerfidelity.com/images/SennheiserHD800.pdf but I feel it a bit a bit smoother like electrostatic do.


----------



## elmoe

gilency said:


> Probably not. The Megatron really caught my eye and it has been a real fun built.
> Main reason for not going for the T2 is difficulty getting some parts, although if I can get me a board I might be tempted  though


 
  
 Is there any chance you'd post pictures of your Megatron build? That amp also caught my eye awhile back!


----------



## HeadphoneAddict

hun7er said:


> Thank you for your answer. I didn't hear the HE60 and SR007 on KGSSHV. But even on another amp my thinking is rather you even I found the HE60 not spacious as the HD800.
> 
> http://www.innerfidelity.com/images/SennhheiserHE60.pdf is not as flat as the HD800 http://www.innerfidelity.com/images/SennheiserHD800.pdf but I feel it a bit a bit smoother like electrostatic do.




The HE-60 in those PDF files are mine (loaned to Tyll). 

The HD800 and HE-60 both have large soundstage, but HD800 have a deeper or more distant soundstage, while the HE-60 have the sound of the venue (ambience and air) coming from everywhere and nowhere at the same time in a similar fashion, with more up-front instruments. Yet they still have decent instrument placement most of the time. 

Somehow they both remind me of a well driven SR-009 due to the "surround sound effect" and are not terribly dissimilar like the 007.


----------



## Hun7er

From my memory the HE60 also have thicker sound, less articifial tone than HD800.


----------



## MacedonianHero

headphoneaddict said:


> The HE-60 in those PDF files are mine (loaned to Tyll).
> 
> The HD800 and HE-60 both have large soundstage, but HD800 have a deeper or more distant soundstage, while the HE-60 have the sound of the venue (ambience and air) coming from everywhere and nowhere at the same time in a similar fashion, with more up-front instruments. Yet they still have decent instrument placement most of the time.
> 
> *Somehow they both remind me of a well driven SR-009 due to the "surround sound effect" *and are not terribly dissimilar like the 007.


 
  
 As I read this, I was settling in with my SR-009/KGSSHV and a few Chesky recordings I have on hand and you hit the nail on the head!


----------



## johangrb

headinclouds said:


> Oh I see you've sold the 007 MkII.  Did you  hear the 009 with your KGSShv?  Perhaps you have posted about this elsewhere.


 
 Hey Geoff - thought I'd could pipe up here as one of the lucky few to own one of your builds.
  
 I recently upgraded from my 007MKiis to the 009s. A big step up in terms of cost, but absolutely worth it imho. Bigger soundstage, more detail and bass yet never sibilant or strident.
  
 The only step up I can see from there would be the BHSE +009 combo (which I heard & loved at a recent head-fi meet). When my ship comes in... 
  
 Bottom line: KGSSHV + 009: highly recommended.


----------



## headinclouds

Hi Johan!
  
 Stop it you lot. Soon I'll hear 009 on one of my builds and then I suspect I'm done for.
  
 I do find that the 007's are so good they overcome most of the limitations of HPs for me.  I don't feel I want for anything more, the purist in me says I don't need to spend so much on "earwhatsits".


----------



## paradoxper

Sucker. 

 


 


Neg, you haven't let this gentleman hear your 009? SHAME!


 


I still have the 007 head and shoulders above everything else except the 009, so I can understand where you're coming from...but..


I felt the same way as you did until I didn't. Let us know when you've come over to the darker side, er, see the light.


----------



## headinclouds

This got me to thinking of Oscar Wilde and temptation
  
 Here's your homework then
  
 http://www.brainyquote.com/quotes/keywords/temptation.html


----------



## kothganesh

paradoxper said:


> I am, er, uh, was. I have no headphones! Haha. SR-009 soon though.


 
 Cory, feel for ya ! What is the ETA for th 009s?


----------



## kothganesh

headinclouds said:


> It is an aluminium case I designed and made.  It is the only way to get exactly what I want. After the metalwork was done I got it surface finished, anodised champagne gold colour and engraved.


 
 Geoff,
  
 you're killing me 
	

	
	
		
		

		
			





. I have been having great times with the 007mk1 and your KGSShv but the Cube looks stunning. I'll send you an email.


----------



## paradoxper

kothganesh said:


> Cory, feel for ya ! What is the ETA for th 009s?


 
 Shooting for June.


----------



## astrostar59

Hi guys
New subject
*Has anyone built or have a KGSSHV with Balanced XLR in only, but feeding it with RCA from their DAC?*

I have a single ended DAC with RCA out only, so I am curious if using a RCA-XLR built cable would loose any sound quality?

My DAC has fixed line out at about 1.6V - 2V and I would be using the KGSSHVs volume pot for level.

I will build my own RCA - XLR cable, with the 2nd signal connection on the XLR not connected.

Any help would be great.


----------



## astrostar59

Following on from this question, does anyone know the specs for the input level on a typical KGSSHV build? Is it 2V line level, or can it be
more or less to work ok? It looks as though the standard build KGSSHV is for XLR balanced in only right?


----------



## kothganesh

astrostar59 said:


> Hi guys
> New subject
> *Has anyone built or have a KGSSHV with Balanced XLR in only, but feeding it with RCA from their DAC?*
> 
> ...



When I bought the amp, I also bought a RCA to XLR cable from eBay. This has double RCA pins on one end and two XLR connectors on the other. I used this to connect my Bifrost DAC to the KGSSHV. Now I have balanced connectors on both ends since I use the Gungnir as the DAC.


----------



## particleman14

I use xlr to rca adapaters on my kgsshv since my source is single ended.  Can't really hear a difference...  You should be fine.


----------



## HeadphoneAddict

astrostar59 said:


> Hi guys
> New subject
> *Has anyone built or have a KGSSHV with Balanced XLR in only, but feeding it with RCA from their DAC?*
> 
> ...


 
  
 I have something similar to that before, but I used a Jensens Transformers ISOmax to convert the SE output of the DAC to a balanced XLR output. That worked great, and I'd recommend one for you. You can get them as an input transformer or an output transformer, but either can work both ways with the proper gender changing adapters for the XLR jacks.


----------



## David1961

I've sold my GS-Xmk2, so with me just having the BHSE as a main amp, I'll more than likely be getting the KGSSHV assuming Justin starts building that amp at sometime in the future.
IMO the GS-Xmk2 is an excellent amp, but since using PH tubes with my BHSE I just love how my 009's sound, and if something did happen to my BHSE, I wouldn't want to be without listening to my 009's for that long, hence me thinking of eventually getting the KGSSHV, I've also read the 009's sound amazing with the KGSSHV.


----------



## spritzer

headphoneaddict said:


> I have something similar to that before, but I used a Jensens Transformers ISOmax to convert the SE output of the DAC to a balanced XLR output. That worked great, and I'd recommend one for you. You can get them as an input transformer or an output transformer, but either can work both ways with the proper gender changing adapters for the XLR jacks.


 
  
 The amp on its own will do a far better job of doing the phase splitting than any transformer.  The high gain of the amplifier will generate a balanced signal from a single ended source without any external or extra components.  The exact same is true for the humble Stax SRM-252S and most other electrostatic amplifiers.


----------



## lojay

Hi guys, how does the KGSS built by Headamp doc pare to a KGSSHV? I'm looking to buy one to get through the 2 year wait for BHSE....


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## MacedonianHero

lojay said:


> Hi guys, how does the KGSS built by Headamp doc pare to a KGSSHV? I'm looking to buy one to get through the 2 year wait for BHSE....


 
 The HeadAmp KGSS is very nice and clean with great control of the SR009s (never got to hear mine with my SR-007Mk1s as I got them after I sold of the KGSS). The KGSSHV (mine is the 450V 1968SA version with the current increased to 9mA), the bass is better controlled and the imaging is a bit wider. The KGSSHV is the natural progression of the KGSS with improvements across the board. Now both are extremely clean sounding with great detail, just that the HV version does things a bit better across the board.


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## Crashem

particleman14 said:


> I use xlr to rca adapaters on my kgsshv since my source is single ended.  Can't really hear a difference...  You should be fine.




+1 I use the cardas adapters and they seem to work great.


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## kothganesh

macedonianhero said:


> The HeadAmp KGSS is very nice and clean with great control of the SR009s (never got to hear mine with my SR-007Mk1s as I got them after I sold of the KGSS). The KGSSHV (mine is the 450V 1968SA version with the current increased to 9mA), the bass is better controlled and the imaging is a bit wider. The KGSSHV is the natural progression of the KGSS with improvements across the board. Now both are extremely clean sounding with great detail, just that the HV version does things a bit better across the board.


 
 Mac,
  
 if the power supply on-board or off-board for your amp? Thanks.


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## MacedonianHero

kothganesh said:


> Mac,
> 
> if the power supply on-board or off-board for your amp? Thanks.


 
 Off board.


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## lojay

macedonianhero said:


> The HeadAmp KGSS is very nice and clean with great control of the SR009s (never got to hear mine with my SR-007Mk1s as I got them after I sold of the KGSS). The KGSSHV (mine is the 450V 1968SA version with the current increased to 9mA), the bass is better controlled and the imaging is a bit wider. The KGSSHV is the natural progression of the KGSS with improvements across the board. Now both are extremely clean sounding with great detail, just that the HV version does things a bit better across the board.




Thanks! So the consensus seems to be that the HV is an improvement but not a substantial one? I'm quite eager to buy the Headamp built one!


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## MacedonianHero

lojay said:


> Thanks! So the consensus seems to be that the HV is an improvement but not a substantial one? I'm quite eager to buy the Headamp built one!


 
  
 The KGSS is really good, but it depends what you mean by substantial? IMO, the KGSSHV is totally worth it though over the KGSS.


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## lojay

macedonianhero said:


> The KGSS is really good, but it depends what you mean by substantial? IMO, the KGSSHV is totally worth it though over the KGSS.




That's perhaps what I needed to know. It just happens that there is a good deal for the KGSS where I live which saves the wait and the shipping. I also get to test it before I buy. That's why I'm tempted to pull the trigger.

If the situation is that one would seek to upgrade from the KGSS to the KGSSHV, I might have second thoughts about buying the KGSS now...


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## MacedonianHero

lojay said:


> That's perhaps what I needed to know. It just happens that there is a good deal for the KGSS where I live which saves the wait and the shipping. I also get to test it before I buy. That's why I'm tempted to pull the trigger.
> 
> If the situation is that one would seek to upgrade from the KGSS to the KGSSHV, I might have second thoughts about buying the KGSS now...


 
 I owned the KGSS for about a year (HeadAmp version) and it was fantastic with my SR-009s, when I had the opportunity to jump on a KGSSHV (about a year ago), and I'm glad I did!


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## The Monkey

lojay said:


> Thanks! So the consensus seems to be that the HV is an improvement but not a substantial one? I'm quite eager to buy the Headamp built one!


 
  
 Stop messing around and buy it.


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## headinclouds

Here is my last build – a KGSShv Cube with silver finish.  The usual 450v 10mA, servo boards, A-D 41 step attenuator.  Switching for 115/230v ac.  Sounds same as the bigger ones.  It looks big in the first pic.  The second gives an idea of the size.


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## paradoxper

Last build? Ha! You're a glutton for punishment. Plus, that build is way too big Spritzer, er, Geoff.


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## DairyProduce

Why is it the last one?


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## kothganesh

headinclouds said:


> Here is my last build – a KGSShv Cube with silver finish.  The usual 450v 10mA, servo boards, A-D 41 step attenuator.  Switching for 115/230v ac.  Sounds same as the bigger ones.  It looks big in the first pic.  The second gives an idea of the size.



Oh come on Geoff. I'm busy saving up to buy and you're stopping with this?


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## wink

He's probable going to be too busy building the KGST............


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## Radio_head

headinclouds said:


> Here is my last build – a KGSShv Cube with silver finish.  The usual 450v 10mA, servo boards, A-D 41 step attenuator.  Switching for 115/230v ac.  Sounds same as the bigger ones.  It looks big in the first pic.  The second gives an idea of the size.


 
 Very cool.  So you're saying your amp is slightly larger than Station V?


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## DairyProduce

wink said:


> He's probable going to be too busy building the KGST............



Kgst? Where can I find out more about that?


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## kevin gilmore

the usual place.

there was a recent group buy of boards


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## astrostar59

You can read lots of posts at the other head forum. As for Geoff's builds (headinclouds) I can vouch for that.
 I got him to build me a KGSShv and it's awesome, top quality build, nice casework and it sounds fantastic.
  
 I reckon Geoff's KGST will be to the same high standard. He has a design for the exterior. Maybe you should
 PM him for a copy to see.


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## Lan647

What differentiates the KGSSHV from the KGSS?


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## astrostar59

Voltage, bigger mains transformer, higher voltage rails to 450v from around 350v, various other part changes and board changes.
 Quite a different amplifier. Also the head-Amp KGSS will not be the same as a DIY build of that design. I presume you are referring to the head-amp KGSS? Also the KGSS is on-board heat-sinks, there is an on-board KGSShv and an off-board KGSShv, the later has more amps in the power supply.


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## Lan647

astrostar59 said:


> Voltage, bigger mains transformer, higher voltage rails to 450v from around 350v, various other part changes and board changes.
> Quite a different amplifier. Also the head-Amp KGSS will not be the same as a DIY build of that design. I presume you are referring to the head-amp KGSS? Also the KGSS is on-board heat-sinks, there is an on-board KGSShv and an off-board KGSShv, the later has more amps in the power supply.




Thanks! Yes I was indeed referring to the HeadAmp KGSS.


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## Nisbeth

I recently had some KGSSHV and PSU boards made (latest onboard version) and have a couple of pairs left over, so PM me if you need a pair.
  
  
 /U.


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## kevin gilmore

lan647 said:


> What differentiates the KGSSHV from the KGSS?


 
 mainly the current source at the top of the 3rd stage.
  
 Then voltages and power levels


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## gepardcv

nisbeth said:


> I recently had some KGSSHV and PSU boards made (latest onboard version) and have a couple of pairs left over, so PM me if you need a pair.



Goodness gracious, this is too tempting! Reading this thread makes me want to build a KGSSHV so bad.


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## MacedonianHero

gepardcv said:


> Goodness gracious, this is too tempting! Reading this thread makes me want to build a KGSSHV so bad.


 
  
 I've had mine for just over a year and it still has me extremely happy with what I'm hearing from my SR-009s and SR-007MkI's.


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## kothganesh

macedonianhero said:


> I've had mine for just over a year and it still has me extremely happy with what I'm hearing from my SR-009s and SR-007MkI's.


 
 Pete,
  
 you and me both! Had a 5 hour marathon with the 007 mk1 on Saturday and 5 hours with the 009 on Sunday (it is Monday here already
	

	
	
		
		

		
		
	


	




).


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## MacedonianHero

kothganesh said:


> Pete,
> 
> you and me both! Had a 5 hour marathon with the 007 mk1 on Saturday and 5 hours with the 009 on Sunday (it is Monday here already
> 
> ...


----------



## loligagger

Figured I should show my latest hv build. 450V/10mA output current, uses the old semis. Considerably smaller and lighter than my old hv as well.
  

  

  

  

  
 And just for comparison, the new on top of my old hv which is now in purk's hands.


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## gilency

very nice build.


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## mulveling

loligagger said:


> Figured I should show my latest hv build. 450V/10mA output current, uses the old semis. Considerably smaller and lighter than my old hv as well.
> 
> And just for comparison, the new on top of my old hv which is now in purk's hands.


 
  
 Props to you sir -- I heard the bottom amp on that stack, and it's now the best I've heard the SR-009 short of Purk's DIY T2. I could listen to it endlessly with the SR-009 and/or SR-007 Mk I.


----------



## astrostar59

Nice build Liligagger! Did you build it yourself! If yes, top marks for that, I was too scared I admit it.
  
 I enclose my Headinclouds built KGSShv next to David's BHSE for idea of scale.
 I always liked the volume pot in the middle, nice. We couldn't do that on my build as the Khozmo
 would crash with the heatsinks on the PS board, so Geoff put it on the left side with an extension kit.
  
 I agree, the KGSShv (off-board) is superb with the 009s. I heard it with the BHSE and it was as good in most
 areas, they just had different characters i.e. KGSShv warmer (strangely for an SS design) and a bit more bass
 impact, and the BHSE excelling in vocals and midrange. I could live with either amp IMO.
  
 Wonder how good the Carbon amp coming via Kevin G will sound? Exciting to have a vibrant DIY community.


----------



## loligagger

Indeed I built both of those kgsshvs. Thanks for the compliments folks.
  
 On a side note, right now I'm working on a kgst.


----------



## kevin gilmore

astrostar59 said:


> Wonder how good the Carbon amp coming via Kevin G will sound? Exciting to have a vibrant DIY community.


 
  
  
 That picture gives me vertigo.
  
 I like that. Thanks for the names.
 So it will be KGSSHV-CARBON edition  (very soon now)
 and KGSSHV-CARBON-CIRCLOTRON edition  (the power supply scares me)


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## gilency

well, I supoose I can always build more KGSSHV's, especially the moar power editions


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## NoPants

will there be a circlotron with EL34's?


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## kevin gilmore

there is no reason that it could not be, but I'm working on the solid
 state version first. The circuit would otherwise be identical. You
 just have to add floating filaments. Which means 4 extra windings
 on the transformers.


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## kevin gilmore

full power circlotron testing this weekend
  
http://gilmore.chem.northwestern.edu/kgsshvcarboncirc.jpg
  
 target is 40 watts of heat per channel.
  
 All 3 of the 1700V SiC mosfets are to247 cases
 so the final chassis work is going to be brutal.


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## wink




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## NoPants

isn't 40W a bit on the crazy side? 
  
 is my last question a stupid one


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## jcx

40W would be Gilmore's "Green" version if that were the all up instead of just the per stator power budget - now if he means 40 W * 4 ...
  
 Gilmore's, some other's ES headphone amps already exceed 40 W total by 2x: +/-500 V * 10 mA * 4 = 40 W in just the output stages, some burn some more power in regulated supplies, as much again for vacuum tube filament heaters, some push Class A bias up to 15 mA
  
 10 W per Q is no problem for those transistor's package - some PCB mount heat sinks could just do it but people like seeing fins on their boxes so off board heat sinks are fashionable
  
 at least with the Circlotron you now get true push-pull Class A which ideally can push 2x the bias current into to the load - where most previous efforts have used CCS biased SE outputs per Stator


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## kevin gilmore

So that is 20 watts per fet, 40 watts
 And its at least 40 watts for the power supply per channel
 since the power supply is at most 50% efficient plus the
 rest of the power supplies, it is probably close to 90 watts
 per channel.


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## urlgr-A

Hello,
 I am a newbie here considering building a KGSSHV for my DIY stat headphones - inspired by chinsettawong's DIY headphones thread. I have been a regular visitor to this forum for some time and have been thinking about making my own electrostatic set up for some years.  
 I have to say I am in awe of the fantastic work going on here, fitting superlatives escape me. I _know _that what see here is as good as it gets. Marvelous stuff!
 So, on to my humble requests...
  
 I am looking for KGSSHV pcbs for amp and psu. Do you know of the whereabouts of any?
  
 After looking over the parts list, very kindly supplied with Mouser part numbers, I cannot see the transformer or the spec for the transformer.  What transformer do I need and where would you recommend I get one from? 
  
 Regards,
  
 urlgr-A


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## Nisbeth

Sent you a PM.
  
 /U.


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## urlgr-A

Hello Nisbeth,
 I replied to your PM. I hope I did so properly. Are you able to see that reply? If not, well,  I put a _yes_ word in it


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## bbest

Hello!
  
 Who have extra PCBs of KGSSHV latest version?


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## NoPants

You're asking in the wrong place, the KGSSHV has undergone a fair amount of revisions. The eagle files are available online so anyone can do their own small run.


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## bbest

Thanks for advises!
 I have not yet decide that it is better to assemble KGSSHV or T2? Does somebody has an experience of that comparison?


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## astrostar59

I would recommend DIY with a KGSShv. Even that is pretty advanced. Have you done DIY before? The voltages involved are lethal and the assembly and soldering involved is not a cake walk. Also you need to source all the components after you have sourced decent PCBs. The T2 is mega advanced and because of the heat issues, few have managed to build one that.
  
 Anyway, the difference between a really nice off-board KGSShv and a T2 is not that massive I am told. And the cost of a KGSShv would be a third or less to complete IMO.
  
 I have a headinclouds built KGSShv that I use with the 009s and before that the 007 MK2s. It rocks, and is an end game amp for me. Hope this helps you!
  

  

  

 Here is my KGSShv next to David's BHSE (for size comparison).


----------



## bbest

astrostar59 thanks for answer!
 I have read some threads about Stax DIY. Talked with members from there. And fully agree with you now. Nothing to add to your answer, exactly the same thoughts.


----------



## DHTGUY

Hello,
 I' interested in building the KGSSHV on board hearsink version. Do you still have boards left over, and where can I find the BOM/Parts list? Many thanks for your help. What would they cost?


----------



## NoPants

The gerbers are publicly availble for those that want to do their own run. I forget if there's an updated parts list for the latest iteration. 
  
 Cost is probably north of 1k


----------



## DHTGUY

I'm buying boards and parts.
Can anyone sell me a couple of 2SA1968LS? 
Any advantage of using hexfred soft recovery diodes for the bridges (as is common for SS rectifiers for tube designs)

Cheers
Guy


----------



## NoPants

There's IXTP01N100D which you can  use instead of 1968


----------



## ts8051

kevin gilmore said:


> schematics here
> http://gilmore.chem.northwestern.edu/kgsshvproduction.pdf
> http://gilmore.chem.northwestern.edu/kgsshvps8e.pdf
> 
> ...


Hello,
The links does not work.

Theologos Sarafidis


----------



## gilency

go to HC..thats were the DIY action is, especially for electrostats


----------



## elvispreasley

Hello! What part you were using instead of 2SA1968 and 2SJ79, which is super hard to find?


----------



## samsie

elvispreasley said:


> Hello! What part you were using instead of 2SA1968 and 2SJ79, which is super hard to find?


IXTP01N100D

this link might help 

http://tee8tee4388.blogspot.com/2013/07/kgsshv-amplifier.html


----------



## Beefy (Oct 9, 2021)

samsie said:


> IXTP01N100D
> 
> this link might help
> 
> http://tee8tee4388.blogspot.com/2013/07/kgsshv-amplifier.html



It's worth pointing out, that while that person's information seems reasonable, you should never implicitly trust what you read without verification, or commission a build from them. They take Kevin Gilmore's designs and absolutely butcher them. Google or Bing search for 'Kevin Gilmore Megatron Lil Knight Tran Thuan' to see what sort of horror story this person produces.


----------



## paradoxper

Beefy said:


> It's worth pointing out, that while that person's information seems reasonable, you should never implicitly trust what you read without verification, or commission a build from them. They take Kevin Gilmore's designs and absolutely butcher them. Google or Bing search for 'Kevin Gilmore Megatron Lil Knight Tran Thuan' to see what sort of horror story this person produces.


Yes. Avoid these criminals.

You may find accessibility by the likes of common CFA3/Dynahi builders whom show crossover in the stat-world. 

Plenty of very good, trustworthy builders verified.


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## samsie

Beefy said:


> It's worth pointing out, that while that person's information seems reasonable, you should never implicitly trust what you read without verification, or commission a build from them. They take Kevin Gilmore's designs and absolutely butcher them. Google or Bing search for 'Kevin Gilmore Megatron Lil Knight Tran Thuan' to see what sort of horror story this person produces.


I could not comment on Little Knight 's personality as I did not know him well enough.  Perhaps I am the lucky one.   The information from the link is correct.  I knew because I built one and my KGSSHV has been working for the past 5 years.


----------



## Whitigir

bbest said:


> Thanks for advises!
> I have not yet decide that it is better to assemble KGSSHV or T2? Does somebody has an experience of that comparison?


Do both! The T2 is not an easy project to tackle, but if you can, then why not


----------



## Reima

Whitigir said:


> Do both! The T2 is not an easy project to tackle, but if you can, then why not


Is it still possible to find the parts to build a T2?


----------



## Whitigir

Reima said:


> Is it still possible to find the parts to build a T2?


I don’t know about that, I doubt it


----------



## bbest

Whitigir said:


> Do both! The T2 is not an easy project to tackle, but if you can, then why not


I just do T2 right now


----------

