The ultimate DIY? A Stax SRM-T2!

[cspirou]

On 8/20/2018 at 2:39 PM, swampsong said:

Does any of the boards available? i would pick one up, and is there a thread for it? or a BOM?

I bought a couple boards from sorenb. He might still have some available.

[bui501]

Thank you, Kevin and JoaMat.

[JoaMat]

On ‎8‎/‎25‎/‎2018 at 2:38 PM, kevin gilmore said:

It would take a whole bunch of time to netlist the board which would allow filleting. Current board works, so I will leave it alone.

Is it possible to netlist a board without an associated schematic?

[kevin gilmore]

definitely. ratsnest mode in proteus.  makes things much easier when you have to make changes to something that works.

[spritzer]

Yup, I've gone through and netlisted many of our old projects plus assigned values to the parts instead of just silk text. 

[JoaMat]

Great! Now I get it - becoming an expert. Thank you! Which version are you folks working with?

Edited August 29, 2018 by JoaMat

[kevin gilmore]

8.7sp3

I have 8.8sp0 but many things have changed and its not backward compatible, so have not installed it yet.

[JoaMat]

I use 8.5 but I came cross 8.6 just to find out that it had some funny behavior that I didn’t understood so I went back to 8.5. The beauty with not backward combability is that you can read my files but I can’t read yours…   8.3 - 8.4 - 8.4 ….. 8.8 non- backward combability. Just love that business model.

[bui501]

On 8/24/2018 at 8:48 PM, kevin gilmore said:

updated shrunk board files with missing trace fixed and rounded corners

staxt2powershrunk.ZIP

t2shrunk.ZIP

I sent the staxt2powershrunk gerbers to a board house for a run, and they ran into the following error.

Should I be using the netlisted version that Kevin posted?

 

[kevin gilmore]

I made them as gerber version 2, that is what everyone seems to want to use these days. no idea which polygon or layer...

here it is as rs274x

staxt2powershrunk - CADCAM.ZIP

Edited September 6, 2018 by kevin gilmore

[Helium]

Question to Mr. Gilmore: Any chance to see your photos linked in this thread?

Particularly about T2 build progress (making enclosure, stuffing the boards etc. Actually I'd love to see all of them). Could they be uploaded somewhere?

[swampsong]

Yes i would second that, i read through this thread twice and having those early pictures would be great.

My new boards should be here in a week or so and i can finally begin... I probably could have started with the old ones but why not spend more money... lol

-James

 

Here are pics

[Helium]

8 hours ago, swampsong said:

Yes i would second that, i read through this thread twice and having those early pictures would be great.

My new boards should be here in a week or so and i can finally begin... I probably could have started with the old ones but why not spend more money... lol

-James

 

Here are pics

What's wrong with these boards? By new boards do you mean published a week ago?

[swampsong]

Nothing wrong with the boards in the pics, and yes they are the new ones Kevin posted a few weeks ago. I picked up this set from a user on Head-Fi.  Excited to get them and get started

 

-James

[Kerry]

Been busy at work, but managed to pull a new version of the T2 amp board together.

I've added separate modules for the active batteries, balance servo, pre-CCS feeding the output CCS and the opto coupled output servo.  I should be able to plug and play with a few options on these modules.

Here's a rendering (Eagle / Fusion 360)...

 

I still have to test, but so far I'm happy with the layout.

Edited September 19, 2018 by Kerry

[JoaMat]

but, but, nothing in the tubes - must be vacuum tubes……….. 

Looks absolutely beautiful. Very interesting with the modules.

[Rossliew]

That's a minimalist, gorgeous design! Hopefully this will make the T2 more accessible to the masses...

[swampsong]

Looking for the last parts on the BOM, this one says back ordered till January anybody using a substitute or know where i can find some:

1n4007        625-1n4007gp-e3/54

1.0 Amp 1000 VoltVishay Rectifiers

https://www.mouser.com/ProductDetail/vishay/1n4007gp-e3-54/?qs=N4vtoAxH%2fSroP3EzTqv8Nw%3d%3d&countrycode=US&currencycode=USD

and this one says March:

.1uf/50v              80-c324c104j5r5ta

Multilayer Ceramic Capacitors MLCC - Leaded 50volts 0.1uF 5% X7R

https://www.mouser.com/ProductDetail/KEMET/C324C104J5R5TA?qs=cxy41lVAGV93OCTUVZDn7w%3D%3D

And also trying to figure out what type of screws everybody was using these days? going to reread the thread and see if i get any more details on those... Are peek screws still the preferred?

Thanks, new boards were supposed to be here today but post office text said nobody was here, but i was here so i bet I'll have to pick them up Monday...

-James

 

[Helium]

There is plenty of 1N4007 diodes. P/N E3/54 you provided is just a package type. Search another one, this generic diode cannot be out of stock for sure.

https://www2.mouser.com/ProductDetail/Vishay-Semiconductors/1N4007-E3-54?qs=sGAEpiMZZMtbRapU8LlZD0HbIjlpuZ44RKYLoMCkjXw%3d

Same for 0.1uF 50V. There are tons of alternatives. If you would like to stick to Kemet, try searching Kemet 315, 320 series as well. 100V is OK also. Just mind lead spacing. 

[swampsong]

Ohhhh that makes sense, I guess my lack of experience is showing, thank you??

 

Edited September 22, 2018 by swampsong

[swampsong]

Thank you Helium, found them and they are on the way. Hope i can get started this week.

[swampsong]

They are here... guess it’s time to put up or shut up?

[Milosz]

--NEVER MIND (but thanks if you intended to post!)  I FOUND THE SCHEMATICS.-

 

Sorry for being lazy.... can someone please post a link to the DIY T2 schematic (amp & power supply)

I had them but lost them due to a bonehead / senile dementia disk mirroring error, and my searches for them have only yielded links to dead locations at Northwestern Univ.

I suppose I could spend the time and read through every post in this topic, I'm sure they are here, but as I am old I fear I may expire before getting through all 185 pages of posts...

t2schem-b.pdf

t2schempower.pdf

Edited October 12, 2018 by Milosz

[JoaMat]

We have to keep this thread alive, don’t we.

New version of 4093 based timer for T2 PSU - replaces the 555 IC. Makes a LED flashing during pre-heat and get steady when high voltages kicks in.

Old to the left and new to the right.

New in place in the T2 power supply.

[nopants]

Do you guys happen to know the shelf-life of the recommended thermal grease for this? I have some from when I first built the T2 but at some point a hole formed in the tube. Been leaking for who knows how long.

Edited April 28, 2019 by nopants