[HemiSam]

I'll take that as a yes...LOL.  Good stuff.
 
HS

 

[Earspeakers]

The only active Stax gear that doesn't get hot is the equalizers. I guess they figured that in the winter it would warm up the paper walled traditional Japanese houses, and in the summer it wouldn't make any difference anyhow with the humidity 

 I always did my best to visit in the Fall or Spring. 
 
Though to be fair the Mafia amps get hotter. 

 

[HemiSam]

Not my KGST.  I can run it half a day and lay my hand on top of where the tubes stand indefinitely.  Not all the designs are the same outside of the boards.
 
HS

 

[vapman]

What is the origin of the quote I read somewhere that Stax intentionally use hard leather on their pads? Is there a reason cloth pads for certain models just don't exist anymore?

 

[Earspeakers]

My stock KGST gets 100++ at the top of the case which is a generous 6" above the tubes (most KGST builds I see are 3U-4U variants). So I pull the cover, given the tall design of mine the back electronics is well hidden. Even then it's throwing off more heat than any Stax amp (except the T2 of course.). A regulated supply and twice the tubes will do that. Oh well the 727 probably is about the same since it has four tubes. 
 
Something to consider since the ratings on electrolytics plummet at around 100 degrees. 

 

[Ali-Pacha]

Just some thoughts about bass and seal with stax gear.
I've a bald head. One time with my Lambda Sig, because of summer heat, I did try some very thin paper tissues beetween my ears and the cups. Avoiding sweat on earpads look like a good idea.
Or not : bass slam was almost gone.
I knew seal was critical considering bass on Stax...but I never expected it would be THAT much 

 
Ali

 

[HemiSam]

  My stock KGST gets 100++ at the top of the case which is a generous 6" above the tubes (most KGST builds I see are 3U-4U variants). So I pull the cover, given the tall design of mine the back electronics is well hidden. Even then it's throwing off more heat than any Stax amp (except the T2 of course.). A regulated supply and twice the tubes will do that. Oh well the 727 probably is about the same since it has four tubes. 
 
Something to consider since the ratings on electrolytics plummet at around 100 degrees. 

 
 
The heatsinking Geoff did (headinclouds) is exceptional.  The man really knows his stuff on the design and fit and finish.  Perhaps he can share his thoughts with you.  I have pics of the internals, but I don't post those out of respect.
 
I did a google on the Stax da-80 and "you can fry an egg on top of it" pops up....LOL.  Class A amp FTW.
 
http://www.audiogon.com/cgi-bin/fr.pl?aamps&1056077807&&&/Stax-amplifiers-experiences
 
Good thing you installed the fans.
 
HS

 

[Earspeakers]

Geoff does first rate work, for sure, external mounted heat sinks will help. But I'm not saying I have a problem, just pointing out that the stock KGST with board mounted sinks generate a lot of heat. 

 

[rgs9200m]

I have not heard a KGST, but although I really like tube sound (and own tube amps for dynamic phones), my Mjolnir KGSS-HV (mini) sounds nice and bloomy and well-textured and not shrill w/SR009 phones.
I could be fooled into thinking this amp was a tailor made custom match for the 009.
I've heard the 009 at a show with an expensive tube amp and with my Stax amp and always thought I would need to put up with the 009 fatigue factor, but the KGSS-HV makes the 009 engaging and sweet and musical, with a great see-through bass that is full of natural detail.
I mention this because if the heat reported with a KGST is an issue, I would try a solid state KG amp from Mjolnir. It's just a really great amp.

 

[vapman]

Is it okay for me to ask if anyone in here has built a KGSSHV? I've read the build thread twice and feel like I can build it but I also feel like there's something I don't understand about the KGSSHV I don't. I apologize if this is not discussion intended for this thread.
 
still amp-less, but one day I will have one
 
P.S. SRD-7 owners, when I got it at first I didn't realize the Stax transformer boxes and assumed it was a tiny amp. I thought I'd probably replace the power cord with a grounded one and redo the caps, but obviously the caps are not present here! Still, is there any benefit to adding a grounded power cord to this unit? I can't imagine anything else that would be good for it except to maybe clean out the knobs and replace the audio in cable - it has the old stock terminal to plug all your stereo wires into, and even though I know it uses crappy thin wire, I can't bring myself to chop it off! Anyone here own multiple versions of the SRD-7? I only have an early model of the oldest version.
 
It would be really wonderful to own a SRD-7 MK2 one day. I hate that I have one not-real amp for normal bias phones and no amp for pro bias, even though I own Lambdas! This should change soon though...

 

[Earspeakers]

  Is it okay for me to ask if anyone in here has built a KGSSHV? 

 
It's OK to ask, doesn't mean <fill in the blank>. 
 
I just finished one. Hard to source silicon now, some parts have seemingly dried up (1968's or 1986's, I forget). Plus it's an optioned board with a fair number of parts. If you haven't done a build yet I'd suggest to do a KGST. 
 

P.S. SRD-7 owners, when I got it at first I didn't realize the Stax transformer boxes and assumed it was a tiny amp. I thought I'd probably replace the power cord with a grounded one and redo the caps, but obviously the caps are not present here! Still, is there any benefit to adding a grounded power cord to this unit?

 
Small safety benefit to grounding the case. However I'm of the camp that says leave Stax gear alone unless you have to fix something. Too many folks running around doing stupid upgrades and tearing old gear apart, for no good reason. 
 

I can't bring myself to chop it off! Anyone here own multiple versions of the SRD-7? I only have an early model of the oldest version.

 
I've got a variety
 

It would be really wonderful to own a SRD-7 MK2 one day. I hate that I have one not-real amp for normal bias phones and no amp for pro bias, even though I own Lambdas! This should change soon though...

 
Not sure it really matters that much. If I really wanted to go transformer coupling on a Pro I'd get a Woo-Wee. 

 

[vapman]

   
I just finished one. Hard to source silicon now, some parts have seemingly dried up (1968's or 1986's, I forget). Plus it's an optioned board with a fair number of parts. If you haven't done a build yet I'd suggest to do a KGST. 
 
 
Small safety benefit to grounding the case. However I'm of the camp that says leave Stax gear alone unless you have to fix something. Too many folks running around doing stupid upgrades and tearing old gear apart, for no good reason.
 
 
Not sure it really matters that much. If I really wanted to go transformer coupling on a Pro I'd get a Woo-Wee. 

Sourcing silicon and the rest of the high voltage parts was my biggest concern.
Do you think there's much of a sonic difference between the various SRD-7's?
I plan to use my SRD-7 with a Crown D60 for as long as I can handle not buying a Stax amp. the Woo-Wee looks very cool but part of me thinks that if i'm spending $499 I could just get an amp that drives Pros and Normals both.
 
Edit: by "do a build first" do you mean any amp build or a KG design specifically? I just finished repairing an old vector monitor for a Sega G-80, so i'm not scared of the voltages or the building it aspect.. a friend bought the boards a while back and wants to build it as a team effort. I want to build it with him, but if the advice is to not mess with the KGSSHV until you've done something else I will heed that advice.
 
edit 2: Okay, now I really want a Wee-Woo.

 

[HemiSam]

  Geoff does first rate work, for sure, external mounted heat sinks will help. But I'm not saying I have a problem, just pointing out that the stock KGST with board mounted sinks generate a lot of heat. 

 
OK.  I thought we were comparing the heat put out by the KGST vs the DA-80.  Glad you're enjoying your Stax portfolio.
 
I love that a new and highly reliable amp in the $2K range has a reasonable sized footprint, solid state/tubey (i.e. hybrid) goodness and makes my SR-007A's sound so damn good...makes the scream at the turn of a knob w/o being at all harsh.  Married up with the Ygg....homerun for a reasonable investment.
 
Been listening to the SR-003's courtesy of a kind friend and I have to say I'm pretty impressed.  I don't find them comfortable over a long period, but the sound is WAY better than I would have ever expected.  Definitely great value for $.
 
HS

 

[preproman]

I can vouch for Geoff's work on the KGST, they are just so damn beautiful.  It get's warm but not hot as my Pass Labs amp.  That aside.  I've heard a few KGSSHV in years past - I would take the KGST with the 009s, just my preference I guess.  
 

 

[HemiSam]

  I can vouch for Geoff's work on the KGST, they are just so damn beautiful.  It get's warm but not hot as my Pass Labs amp.  That aside.  I've heard a few KGSSHV in years past - I would take the KGST with the 009s, just my preference I guess.  
 

 
Listening to acoustic Zeppelin tracks at the moment...The Battle of Evermore and now Going to California.  Life is good after a long work week....
 
EDIT:  I'm several hours in now and temps up.  I'm reading ~30 degrees above ambient at the vented top plate above the tubes.  Say 80 degrees above ambient if I shoot down into the tip top of the tubes via the vented grid with the infrared thermometer.  You seeing similar or a delta to that?
 
Beautiful stack you have there, pre.  
 
HS