The ultimate DIY? A Stax SRM-T2!

[G600]

Yes I did compare, but it's suspect.

[GeorgeP]

That is the slightly shorter board - I can confirm that it works as it should. The two middle rows are for setting the voltage.

[G600]

Yep, a shrunk blue board.

But the one I have on hands have connection between each and every one of the 6 holes, both vertically and horizontally.

Of course nothing is soldered to it yet.

[GeorgeP]

sorry, are you saying the traces on your board don't match the image you posted above?

 

 

 

 

 

 

[G600]

Yes, this is the only area of both boards with bad looking traces around the holes,making undue connections.

Think I'm going to salvage them, helped by the gerber's bottom copper traces.

[GeorgeP]

so the solder pads are touching? Can you post a photo? The shrunk boards I have match the the Gerber perfectly, with no slop.

 

 

 

 

 

 

[G600]

I may post a picture if I can catch it with my crappy phone.

It looks like leaking copper around the holes, but I can also see direct connections between adacent holes.

[G600]

You can clearly see the "leakage", but at a second look you may peek traces between second and upper third row.

[GeorgeP]

I see, that is something I have never seen before - so there is copper under the solder resist that is creating a bridge between the pads where there shouldn't be any continuity. So your time delay would have had no effect and the amp would be on immediately.

I checked my boardset, and it doesn't have this extra copper - not sure what happened there. Also the through-holes seem to poke out a bit past the solder pads, but I am guessing that hasn't turned out to be an issue.

Did want to mention that I will likely be unloading my extra boardset as it is unlikely that I will be using it. The boards are 4oz copper and 3mm thick, so this is only for people who know what they are doing. The amp board is the shorter version that can use off the shelf 400mm heatsinks (no need for custom pieces).

 

 

 

[kevin gilmore]

hard to see if its really copper from that angle, but what probably happened is that the photo mask lifted

at the edge and caused that.

[G600]

I was sure there was a technical explanation.

I started to salvage the traces, and copper it is. 4 oz. Damn hard to get rid of. Those boards are borderline too much overkill.

[spritzer]

Look what was finally brought back to life yesterday.... 

This has a new board as I could never find out what was wrong with the old one.  Might have found it though...    Anyway, nice to have it alive and kicking. 

 

Btw.  If anybody needs any of the hard to get Xicon resistors used in this, drop me a line.  I bought a lot of them... a lot!!!! 

[blubliss]

Finally!  Good on ya'

[GeorgeP]

Yes, that is awesome news!

And never thought of moving the LEDS to the topside - means you don't have to start it up on its side with both covers off - great idea. Probably want the 22k resistor topside as well.

What testpoints are those?

[GeorgeP]

Also, did you end up going with the 4686 or did you go 3675?

 

 

 

 

 

 

 

 

 

[Kerry]

Very nice!

Congrats

[Hennyo]

Wonderful, nice job!

[chinsettawong]

Putting all the leds on the top side is an excellent idea.  Congrats!

[spritzer]

Thanks.    Having it to play with means I'll probably never build any more of this.  Might finish the three PCB's I have but it would be insane to try and sell this beast.  Even with this updated layout it is still a chore to build. 

Also, did you end up going with the 4686 or did you go 3675?

This one is completely stock, Xicon parts everywhere and all the stock sand.  I even used the 1486's where KSA1156's would have worked just fine.  The test points are just some teflon units off ebay but they work perfectly.  Since this was a custom PCB I spaced them further apart to the test leads would fit comfortably. 

[GeorgeP]

Thanks.    Having it to play with means I'll probably never build any more of this.  Might finish the three PCB's I have but it would be insane to try and sell this beast.  Even with this updated layout it is still a chore to build. 

 

Yeah, its like the Ironman of amp builds... and that is if nothing goes wrong... commercial viability = 0.

[nopants]

Saw this on Schiit's website, made me think of those users who were opting for the SS input stage on their T2s:

http://schiit.com/products/lisst-tubes

I dig the aesthetics

[UFN]

Saw them as well - and immediately started dreaming up around 57 potential ways to violate Schist's advice of "Do not use these in other products" 

 

//UFN

[Earspeakers]

Interest check for a group buy for T2 boards. I have a quote from Custom Circuit boards for $125/amp, $100 PSU, ENIG, 2.36mm, 3oz copper, 100% e tested in quantity 4 each. These are the shortened boards, GeorgeP has verified the PSU is good (we've already got a set each). 

I want one, if three others are interested I'll do the buy. PM me if interested, if I don't get enough interest here I'll do a separate post to call it out. 

[chiguy]

Are these boards with new or old sand?

[Earspeakers]

Are these boards with new or old sand?

No sand, just the PCB's. We've done a run of 4 boards already and the PS has been built out and tested as mentioned and the Gerbers have been previously fully built out and verified by others. Correction to above, these are not the shortened boards.