The ultimate DIY? A Stax SRM-T2!

[mirumu]

Been talking to Carl and we're both keen on building one of these.

[kevin gilmore]

Quotes for PCBs after 1 day, amateurs

3 days !

So if i'm an amateur what do you call mikhail...

[kevin gilmore]

If bigir finds me another T2 floating around for sale from a reputable dealer/person

i would buy it just to add it to the collection of other things.

I can do a better job 25 years later. But justin class chassis's are a whole bunch

of work. At least i'm very now well familiar with the 3D milling machines and the

software, so i can make a chassis with all sorts of pretty holes pretty easily And

even go for completely custom one piece heatsinks. Then ship the stuff out

for anodizing. Should cost about $1k for the chassis. Assuming the labor is free.

The arlon circuit board makes no difference as the lower capacitance is

definitely not necessary, and it probably would have to be much thicker to hold

off the 1kv floating around.

This is pretty close now after about 18 hours of work.

http://gilmore.chem.northwestern.edu/staxt2rev0.bmp

at least all the obvious errors are gone, and the ground plane

has about 95% coverage once i add it.

Edited August 10, 2009 by kevin gilmore

[spritzer]

1k-2k$ for the chassis isn't a bad deal but we simply have to make it in that gun metal gray.

If bigir finds me another T2 floating around for sale from a reputable dealer/person

i would buy it just to add it to the collection of other things.

I will continue to search.

[Torpedo]

Oh yes, I like that gun metal or titanium gray

[kevin gilmore]

proposed power supply for high voltages

http://gilmore.chem.northwestern.edu/staxt2multips.jpg

There will be at least 5 of them. +500, +250, -250,-500, -560

might be overkill for the bias.

Way better than 1% regulation. Not dual tracking, that is a lot more work.

and probably unnecessary due to the servo's already in the thing.

Could do them as shunt regulated supplies, they would then dissipate a bunch

more heat.

[luvdunhill]

Is it really possible to draw 100mA from the 10M90S?

[kevin gilmore]

They say so, but in any case i'm going to put 2 in parallel at 50 ma each

just to make absolutely sure. Amp as is runs 80ma.

[justin]

This is pretty close now after about 18 hours of work.

http://gilmore.chem.northwestern.edu/staxt2rev0.bmp

at least all the obvious errors are gone, and the ground plane

has about 95% coverage once i add it.

you have a shorted LED all the way on the top left

[Icarium]

I want one too ;p 3-4 sets of boards at least and at least 1 chassis if its an option And of course help with prototyping costs.

[kevin gilmore]

you have a shorted LED all the way on the top left

And its mirror cousin. Fixed those two... thanks..

the npn on the power schematic is actually a 2sc3340 and

the reference will be a ref102 because its less than half the price for

the same thing.

[pabbi1]

I'm going to end up somewhere next year with lots of sand and nothing to do. This will definitely be on my list of time killers.

Amazing you keep stat equiptment in places like this:

That was BFE West of Baghdad

This is BFE Kandahar (compliments of my brother with MARCOM)

Someone in Israel asked me how to keep dust off the stats - I wouldn't have the first clue, as I understand it to be more like talcum.

[kevin gilmore]

power supply coming along.

http://gilmore.chem.northwestern.edu/staxt2rev0power-2.bmp

Need +/-12 and high voltage delay circuit.

have the one of the supplies on the bench for testing, works great.

Initial quote for the transformers is 3.7 OD, 1.8 High. Plenty of room

in the box for 3 of them.

[kevin gilmore]

Things are coming along, current board has layout for standard (i.e. cheap)

and the teflon sockets, i'm thinking of going with the teflon sockets only.

Any opinions on this...

Definitely going to be less than $2000 in parts not including chassis.

even with the teflon sockets and the SumR transformers.

[Icarium]

I'm down.. if we can keep the parts cost at around 2.5k - 3k I should be fine.

[Beefy]

Things are coming along, current board has layout for standard (i.e. cheap)

and the teflon sockets, i'm thinking of going with the teflon sockets only.

Any opinions on this...

Not that I could ever build one...... but IMHO considering cheap sockets seems a bit silly in a build of this magnitude

[seacard]

Man, I wish I had some technical skills. Justin, you going to be making these? Naamanf?

[kevin gilmore]

teflon sockets only it is. Actually looks a bit better this way.

Anyone that can build a dynahi can build this. If you stuff all the

parts in the right place and can do a really good job of soldering

it should be a snap.

http://gilmore.chem.northwestern.edu/staxt2connexonlyrev0-2.bmp

ground plane removed for picture otherwise it wipes everything away,

components that don't look like they have a lead connected are connected

to ground

http://gilmore.chem.northwestern.edu/staxt2rev0power-6.bmp

i even have a bill of materials. (first time ever)

so i have a clue how much its gonna cost, and how many more parts to buy.

231 semiconductors makes this the most complicated headphone amp ever.

Edited August 21, 2009 by kevin gilmore

[Beefy]

Anyone that can build a dynahi can build this.

That isn't as much of a help as you may think

[seacard]

Anyone that can build a dynahi can build this. If you stuff all the

parts in the right place and can do a really good job of soldering

it should be a snap.

I can see at least three things there that I would be unable to do. Maybe more.

[Icarium]

Question: How much heatsinking will this need in comparison to the BH?

[Hopstretch]

PM HeadphoneAddict. He can probably knock one together for you after he finishes up his Blue Hawaii.

[Beefy]

PM HeadphoneAddict. He can probably knock one together for you after he finishes up his Blue Hawaii.

Oooooh, kitty has claws!

[Icarium]

Basically its like putting together one of those 1000 piece puzzles right? except sometimes electricity might come and kill you.

[kevin gilmore]

Question: How much heatsinking will this need in comparison to the BH?

mostly due to layout. BHSE has 2 heatsinks 12 inches long.

plus heatsinks inside the power supply.

T2 amplifier has 2 heatsinks same height 17 inches long.

T2 power supply has 2 heatsinks same height 17 inches long.

(it really does not need this much, but it will look better when

sitting under the amplifier.)