The ultimate DIY? A Stax SRM-T2!

[Dusty Chalk]

Not a joke. But i don't expect anyone to buy one either.

I have enough gold in stock for 3 knobs, and enough platinum

in stock for one.

But i do like the idea of making knobs out of titanium. Looks like you

made it out of sterling, except that it does not tarnish.

Well...by "joke" I mean that one is not obliged to use them, as with other parts; not that they aren't real. I have no doubt that you are entirely serious about the knobs.

[seacard]

How long before we have to make a decision? I'm in if I can find a builder, although it seems pretty unlikely.

[Icarium]

Honestly seacard... my thinking was this. The chassis honestly is an amazing deal (I speak from experience trying to source chassis for the Dynafet project) and the boards aren't going to be a common thing either. The fact that the chassis will be finished/drilled/tapped will make this project like 50-66 percent less painful as chassis work is one of the biggest banes of most DIY efforts. Not that the work that is left won't be painful enough.

Worst case scenario you try and use the chassis for another project if it comes back to that.

I'd spent the 1.3k - 2k it would cost to get the chassis/boards/sockets/rare transistors/parts and get a list of everything else you need and then try and drum up a builder. I personally was going to work through a list of projects I have parts/interest in and hope to be ready to do it myself by the end of 3 years of lesser projects. I was in fact going to get two sets as to have one set to offer to my builder in case I wuss out... alas the money.

Unfortunately I had to give it up when I added up what I have in audio right now and it's something like 40-50k (If you include the SS-1 which I wasn't even factoring previously but agh who could forget the travesty/waste of money the Singlepower SS-1 is/was) and another 8-15k for this amp, tubes, headphones.. yeah I had to give it up.

If you want an electrostatic amp it's really this, the BHSE, other variations of the BH and the Vulcan that really are at the tip top for me personally and all but 1 of those need DIY ;p.

The only thing that could potentially eclipse it is the all DHT amp and its variations (Justin may do it as an aristaeus 2 at some point but cost will be something like 12-20k or something...).

That was my line of thinking anyways...

[Dusty Chalk]

What's a Vulcan? This?

[n_maher]

What's a Vulcan? This?

Oh nononono, the Vulcan is a Blue Hawaii on steroids. About as far as you can get from the linked project as you can get.

[Icarium]

Pabbi linked a picture of one at some point and I think he's the only one that's built one? Talking with luvdunhill who I believe designed it? He says that its actually more like the woo amp WES or was it the GES? I forget which one its like... but yeah it's a whole other direction.

If you consider the BH to be one tangent and the Vulcan to be one tangent I think the T2 is somewhere in between sharing like 50-75 percent overlap with the BH... but with more tubes to roll and other differences.

Anyway I'm not technical so correct me if I'm wrong?

[spritzer]

I really should get started on the Vulcan...

The T2 is the front end of the SRX design (aka the fabled ES-1/ES-2) with the output stage of the BH.

[blubliss]

This sounds interesting. I listened to the BHSE 2x (CanJam & and 909's house) and I did not dislike it but I like the ES-2 better. Maybe with more time that would change but that's where I am at now.

Will the DIY T2 sound closer to the BHSE or ES-1 or in between. Maybe this is a stupid question with no answer?? And could it drive the O2 and Omega1/HE90 equally well. If so I may have to enter the fray.

[j4cbo]

I'd pay $150 for an autographed Kevin Gilmore solid titanium knob

Same here

[Icarium]

I take full credit for my only valuable contribution in this thread! Titanium knob!

[kevin gilmore]

DIY ES1/2 coming

Same chassis(s)

Same power supply as the T2 except 2 of the supplies are unpopulated.

Rigged as +400, -400 and -450. Quad filaments.

And REAL bias supply.

Amp board would be trivial for anyone to build as there are virtually no parts

other than the 8 tubes. Still going to be the connex sockets however...

So you guys want autographed...

How about micro engraving?

http://gilmore.chem.northwestern.edu/num.jpg

thats a .002 diameter carbide bit plowing .003 into polished stainless.

(thats about 50x)

(i love my new eyes...)

Edited September 12, 2009 by kevin gilmore

[Pars]

<snip>

The fact that the chassis will be finished/drilled/tapped will make this project like 50-66 percent less painful as chassis work is one of absolutely the biggest bane of most DIY efforts.

FTFY. Not that I, of team dead fucking cheap, would consider 1K or more a bargain for anything, but for this I could see it.

[jgazal]

What's the difference between Spritzer's SRM-T2 (which is the paradigm of this DIY project) and this one below?

[Icarium]

FTFY. Not that I, of team dead fucking cheap, would consider 1K or more a bargain for anything, but for this I could see it.

Well the chassis themselves are like what? 500 bucks for a set? Or like 700 if you include all the mounting brackets and other random bits? It's not a bargain per se, but the chassis is going to be like professional finished/powdercoated and not be ugly... maybe not quite as nice as the bhse/frank cooter work, but You get your moneys worth if it looks matter to you.

Plus its amp chassis + power supply chassis so really two...

[nattonrice]

Hello Dr Gilmore,

I know that I am new here and I hope I am not over stepping my mark.

May I join in on one complete set of everything?

That is, the board set, heat-sinks and casing, components being offered, ect.

I live in Sydney AU.

If it helps I promise to video the first time I flick the power on o(^^)o

Kind Regards

Tom

[spritzer]

There will also be a mini ES-1 coming too (once I have some free time to draw up the PCB) which will only use triodes.

This sounds interesting. I listened to the BHSE 2x (CanJam & and 909's house) and I did not dislike it but I like the ES-2 better. Maybe with more time that would change but that's where I am at now.

Will the DIY T2 sound closer to the BHSE or ES-1 or in between. Maybe this is a stupid question with no answer?? And could it drive the O2 and Omega1/HE90 equally well. If so I may have to enter the fray.

It's a mix of those two but more like the BH. It has a softer touch as it shows the drawbacks of lesser headphones not quite as brutally as the BH and the same goes for cheaper sources. Now whether this will be translated into the DIY amp is hard to say since they aren't direct clones.

I'm not sure how the HE90 would fare with the T2DIY but I'd guess it wouldn't be a great match. They need a sympathetic amp and besides a slight extra midrange presence I'd say the T2 is pretty much ruler flat. The SR-Omega should be an excellent match just as the SR-007 is.

What's the difference between Spritzer's SRM-T2 (which is the paradigm of this DIY project) and this one below?

The stock Stax T2 has a rather simple R-C-R-C PSU design for the high voltage part and runs the EL34's at 10W each. The DIYT2 will use fully regulated and tracking PSU's for the high voltage and run the EL34's at 20W each, same as the BHSE.

Now what this can be a good and a bad thing depending on what people prefer their amps to sound like. Take a KGSS and SRM-717 comparison, the circuits are very similar and yet some people don't like the KGSS and like the 717. The Stax amp has a similar PSU to the T2 while most KGSS amps use the same PSU as the old BH amps i.e. fully regulated.

[Les_Garten]

There will also be a mini ES-1 coming too (once I have some free time to draw up the PCB) which will only use triodes.

It's a mix of those two but more like the BH. It has a softer touch as it shows the drawbacks of lesser headphones not quite as brutally as the BH and the same goes for cheaper sources. Now whether this will be translated into the DIY amp is hard to say since they aren't direct clones.

I'm not sure how the HE90 would fare with the T2DIY but I'd guess it wouldn't be a great match. They need a sympathetic amp and besides a slight extra midrange presence I'd say the T2 is pretty much ruler flat. The SR-Omega should be an excellent match just as the SR-007 is.

The stock Stax T2 has a rather simple R-C-R-C PSU design for the high voltage part and runs the EL34's at 10W each. The DIYT2 will use fully regulated and tracking PSU's for the high voltage and run the EL34's at 20W each, same as the BHSE.

Now what this can be a good and a bad thing depending on what people prefer their amps to sound like. Take a KGSS and SRM-717 comparison, the circuits are very similar and yet some people don't like the KGSS and like the 717. The Stax amp has a similar PSU to the T2 while most KGSS amps use the same PSU as the old BH amps i.e. fully regulated.

Very interesting comparisons here.

How do you compare the 717 vs the KGSS?

Could you give a "personal" hierarchy of how you Tier them? Showing levels and also showing amps that occupy equivalent levels?

From reading most threads related to DIY or third party, you kind of get the idea not to get any STAX amps.

[Smeggy]

DIY ES1/2 coming

Same chassis(s)

Same power supply as the T2 except 2 of the supplies are unpopulated.

Rigged as +400, -400 and -450. Quad filaments.

And REAL bias supply.

Amp board would be trivial for anyone to build as there are virtually no parts

other than the 8 tubes. Still going to be the connex sockets however...

Hmm, color me interested now.

[kevin gilmore]

I just hate it when good quality parts are no longer available.

I'm looking for (a regularly stocked item) pcb mount rca jacks.

(not those 99 cent pieces of shit)

tiffany style like on the older krell stuff. or cardas gfca style.

vampire rca connectors no longer in stock anywhere...

neither are the gold neutriks.

otherwise its going to stay XLR only, and you can buy the neutrik

rca to XLR converters.

The stock T2 supply is not RCRC. In fact its just diode bridge into

capacitors...(balancing resistors and discharge resistors don't count)

An ES1 amplifier section is 8 tubes, 36 resistors, 4 GOOD capacitors, 8 pots, 4 cathode capacitors...

(yep thats it)

Edited September 12, 2009 by kevin gilmore

[digger945]

http://www.partsconnexion.com/product7512.html

[Beefy]

I'm looking for (a regularly stocked item) pcb mount rca jacks.

(not those 99 cent pieces of shit)

tiffany style like on the older krell stuff. or cardas gfca style.

vampire rca connectors no longer in stock anywhere...

neither are the gold neutriks.

The ones Justin sells are no good?

HeadAmp Audio Electronics (Order) - right down the bottom.

[digger945]

Cardas plug and socket

MC Audio - CARDAS AUDIO Connectors

http://www.thecableco.com/product.php?id=5318

http://www.thecableco.com/prodListing.php?cat=79&man=&sort=&st=all

Apparently Moon Audio doesn't carry those any more.

THL Audio has some also.

[kevin gilmore]

let me be slightly more specific.

something like the old vampire right angle single rca jacks, circuit board mount.

justin's are not right angle..

The connex one is the only one currently available, and it is way to long, i.e.

i have to mount it 1 inch back from the circuit board edge to get it to fit the

backpanel.

The cardas is even longer as a dual.

[digger945]

Maybe if you knew how to design and lay out an amp, you wouldn't have such a hard time finding parts now would ya.

[Smeggy]

I just hate it when good quality parts are no longer available.

I'm looking for (a regularly stocked item) pcb mount rca jacks.

(not those 99 cent pieces of shit)

tiffany style like on the older krell stuff. or cardas gfca style.

vampire rca connectors no longer in stock anywhere...

neither are the gold neutriks.

otherwise its going to stay XLR only, and you can buy the neutrik

rca to XLR converters.

The stock T2 supply is not RCRC. In fact its just diode bridge into

capacitors...(balancing resistors and discharge resistors don't count)

An ES1 amplifier section is 8 tubes, 36 resistors, 4 GOOD capacitors, 8 pots, 4 cathode capacitors...

(yep thats it)

Is there a schematic abouts anywhere I can look at, also PSU requirements?