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New listening impressions of Stax C32 prototype and Shipping SR-009
Jun 26, 2011 at 8:08 AM Post #1,096 of 1,514
Hi Spritzer, I'm a little confused about the overlapping projects. Apparently, the Blue Hawaii is grandfathered in from the original T2. However, they are not verbatim because you pointed out the differences in lay-outs, heat dissipation power supplies and background signals. Despite these fixes that would imply that the Blue Hawaii is an upgrade revision of the T2, people are still going out to build the original T2 at extensive costs. From their motivations, the DIY T2 seems to be the ultimate lay-out. Consequently, is the DIY T2 seemingly taking a step back out of purism or are there recently discovered advantages to the DIY T2 over the BHSE? I guess for some of us reading the problem is we do not know how closely the DIY T2 follows the original because it implies that it will bring back old problems whereas the BHSE seems like a more modern alternative.
 
Jun 26, 2011 at 9:28 AM Post #1,097 of 1,514
The original BH was designed by Doctor Kevin Gilmore without having the T2 on hands and knowing the schematics. Unlike the original T2, it doesn't have the tube input stage (read http://gilmore2.chem.northwestern.edu/projects/showfile.php?file=gilmore4_prj.htm). BHSE is an improved version of the BH to deal with the obsolete devices, along with many more improvements. It's no doubt that the BHSE is the best commercial electrostat amp you can buy.

The original T2 is a monster with tube input and output stages. It has a lot of issues like Spritzer mentioned before (heat, hum, PCB layout). Thanks to his generosity, the DIY T2 was born, with the schematics drawn by Doctor Gilmore. AFAIK, the amp section was kept as-is (with some tweaks to help stabilize the amp). The PSU is a completely different design which is much, much better to make the amp run at full potential. Adding the beefed-up side heatsinks, better PCB and components on top of that would make the DIY T2 the most complicated and highest performance headamp ever. Problem is, you can't buy the DIY T2 (or maybe, but with a lot of cash) :) The parts cost for the DIY T2 alone will buy you a BHSE.

I personally won't call the BH is an upgrade revision of the T2 though.
 
Jun 26, 2011 at 2:40 PM Post #1,100 of 1,514
He is a staff engineer at the Northwestern University sciences department, though I'm pretty sure he's not a professor (where would he get all the time to design electronics?
biggrin.gif
).  Whether he has a doctorate, I couldn't say.  He'll always have a Ph.D. in electrostatics in my eyes!!!
 
Quote:
visualguy said:
 
I keep seeing references to Kevin Gilmore as "Doctor". I never saw him claiming that he had a doctorate degree... He certainly deserves an honorary one from Head-Fi, though!
 
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Jun 26, 2011 at 5:01 PM Post #1,101 of 1,514
You make the original T2 sound like a SinglePower creation which it's not.  
In 1994 the T2 retailed at 460,000 Yen I believe a huge sum then, more than the new SR-009 today.  They were produced to drive the original Stax Omega so very few were made,
I have had mine for several years and it has proved very reliable and no hum.  The so called issues you talk about have had no impact on daily use except making sure the unit is kept well ventilated.  A lot of myth, legend and hearsay has grown up around them propogated by people who have never owned one. Yes they do get hot but no more than some transistor amps like those of Nelson pass FirstWatt for instance. 
 
I believe Kevin Gilmore may have had permission from Stax Japan directly to use the original circuit design of the original for his DIY T2, provide they are not sold as a commercial product in any way.  Kevin has made some updates to the original, particularly the power supply and use of up to date components etc,that were probably not available or cost effective 17 years ago. Producing a commercial product that has to be sold on the open market at a profit is very different to building something yourself. 
 
Quote:
lil' knight said:
The original T2 is a monster with tube input and output stages. It has a lot of issues like Spritzer mentioned before (heat, hum, PCB layout). Thanks to his generosity, the DIY T2 was born, with the schematics drawn by Doctor Gilmore. AFAIK, the amp section was kept as-is (with some tweaks to help stabilize the amp). The PSU is a completely different design which is much, much better to make the amp run at full potential. Adding the beefed-up side heatsinks, better PCB and components on top of that would make the DIY T2 the most complicated and highest performance headamp ever. Problem is, you can't buy the DIY 
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Jun 26, 2011 at 8:40 PM Post #1,102 of 1,514
livewire said:
Well said Lil' Knight. When will your T2 be operational? Any progress on the KGSSHV?
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Progress is slow like turtle. :xf_eek: I don't have much experience with chassis work so it would take quite a long time to finish the thing.
I already got a working KGSSHV on the bench but I think I'm gonna build a new PSU for it.

@complin. I didn't know someone here owns an original T2. Good to hear that yours has been working fine.
I saw many pics of the inside and felt the heatsinks are clearly not adequate for the job. Most of them are just tiny on-board ones and putting all the tubes inside is not a good idea to me. Did you ever measure its working temperature?

Hell, I never said it's something like the SP. They are absolutely different beasts.
 
Jun 27, 2011 at 6:12 AM Post #1,105 of 1,514
@ Lil' Knight Progress is slow like turtle.
redface.gif
I don't have much experience with chassis work so it would take quite a long time to finish the thing 
 
We have done the chassis part of  the DIY T2.   Chinsettawong is very good at that.
We are lucky to get the HE90 chassis female socket from Moon-audio which was thought previously to be back ordered.
We will get the original stax chassis female socket too , soon from EU.  When we get that we will replace the existing one.
Chinsettawong are beginning the power supply unit .   BTW Lil' Knight, your PCB's board is very good, is it the most updated version?
 
Are there anything that we should be careful ?  except for the smoke????
biggrin.gif

Please help us on this, we are quite scared.
eek.gif

 
 
BTW we got the CCa that we wanted : Valvo CCa pinched waist 2 matched pairs, Telefunken CCa ULM diamond mark quad, Siemen Halske CCa Quad and Amperex 6922  quad  : these are the 6DJ8's and for the EL34's we have got some too.  I have finished my parts for the tubes.
 
Need to stop shopping  and need  more real job work to fund the project
 
 
Now it's building time.  Chinsettawong will update from time to time and need to ask some questions about the PSU tricks
 
Jun 27, 2011 at 7:20 AM Post #1,108 of 1,514
Yes, the PCB is the latest revision.

I'm also waiting for the HE90 chassis jack :frowning2: Price has become ridiculous for a mere connector these days.
Why bother with the the stock Stax jack? The teflon one is not good enough for you?

Did you get the chassis from Doctor Gilmore or make it on your own? Your tube collection is mouth-watering.

Please don't ask me about the build lol. I'm in the same situation with you guys. :xf_eek:

I feel like I'm derailing the thread, sorry about that.
 
Jun 27, 2011 at 8:09 AM Post #1,110 of 1,514
Why bother with the the stock Stax jack? The teflon one is not good enough for you?
 
I just follow my mentor, Spritzer use that and I think it's a good idea for me because I don't
know much about this business so I try to do the way that other has done before.
 
 
Did you get the chassis from Doctor Gilmore or make it on your own? Your tube collection is mouth-watering. 
 
Yes I get one original chassis from Kevin Gilmore (the reason is as above).   Thanks for complimenting my tube collection.
I don't know much so I try to get those beter ones but I think it's not just the brand of the tubes or the prices but the synergy
between several factors and Chinsettawong and others will do that, I just do the best of my part.
 
Let's hope that there is no smoke at our place.
Sorry about the derailing too.
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