The ultimate DIY? A Stax SRM-T2!

[luvdunhill]

looky here...

[ATTACH=CONFIG]3305[/ATTACH]

[Nebby]

Those heatsinks are nice, where'd you get them?

[cetoole]

I really like that knob, looks great, and I agree that will be perfect with a black case.

[Pars]

Yeah, that knob is way nice. That is titanium?

BTW, what ever happened to that guy on hf that was doing knobs? Seems like he disappeared, but I guess I haven't been over there much (at all) lately. I think he did a titanium one or two...

[kevin gilmore]

Yep, titanium. Very hard to machine correctly. Need special carbide tools, and if you don't get the

feed rates right, the tools shatter. Or the surface ends up with golf ball dimples.

[Voltron]

Killer knob!

[spritzer]

The only thing needed to finish off a truly over the top amp... a solid titanium knob. It was either this or pay a retarded anodizing fee for a one off silver knob.

[kevin gilmore]

dact mounting brackets and a custom piece for Inu

http://gilmore.chem.northwestern.edu/t2bits.jpg

definitely on schedule for stax jacks next week and

more angle brackets the week after.

Edited July 1, 2010 by kevin gilmore

[Inu]

I am afraid to apply HV to the amp board...

Picasa Web Albums - inuponken - T2

[justin]

confirm the LV and heaters are working, then do what i do. goggles on, flip the switch from a safe location in case there is shrapnel

[Les_Garten]

confirm the LV and heaters are working, then do what i do. goggles on, flip the switch from a safe location in case there is shrapnel

You forgot the Hi Speed Video Camera!

[nattonrice]

As long as you flip it while facing Mecca you should be fine... =)

Looks awesome btw.

[wink]

Mecca...? Is that on the way to Pismo Beach? via Alberquerque?

[Craig Sawyers]

I am afraid to apply HV to the amp board...

Picasa Web Albums - inuponken - T2

Looks awesome! Turning on power for the first time is a really sweaty palm moment. Always. The only insurance is to check, check - have a cup of coffee and go for a walk then check again.

[El_Doug]

I am afraid to apply HV to the amp board...

Picasa Web Albums - inuponken - T2

Good luck! Your build is stunning

[Beefy]

I am afraid to apply HV to the amp board...

Picasa Web Albums - inuponken - T2

I think I just came a little.

[kevin gilmore]

No guts, no glory.

Check things over 9 times and then have at it.

As long as there are no shorts on any of the current sources, no parts should fly.

Make sure all the pots are set in the middle, makes things much easier.

[Voltron]

Yew can dew eet Inu! Beautiful work thus far, and good luck with the next steps.

[Inu]

Thank you for the advice.

Before soldering, adjusted in the middle position for all pots.

Check Current Sources = OK, no shorts.

Cafe break = done

Wear goggle = OK

Flip the switch from the safe location.

Confirmed all heaters are ON and wait for the timer

[spritzer]

No burning parts is a good sign but did you test all the LED's prior to installing them?

[digger945]

Heh..lt wouldn't be a Gilmore design unless you had to adjust for the LED's to come on....

[Inu]

No burning parts is a good sign but did you test all the LED's prior to installing them?

Yes, before install, I measured;

Vf for all LEDs and diodes.

hfe for all TR

[Icarium]

Man so want titanium knobs.

[spritzer]

Wrong value would be my guess then.

[Craig Sawyers]

Thank you for the advice.

Before soldering, adjusted in the middle position for all pots.

Check Current Sources = OK, no shorts.

Cafe break = done

Wear goggle = OK

Flip the switch from the safe location.

Confirmed all heaters are ON and wait for the timer…

No smoke and flying parts however,

LED D1, D6,D7,D10,D11 D23 and D24 for both channel does not lit up.

Active battery stays 808V and can’t adjust.

I am regretting that I did not facing Mecca.

That got me thinking. Doing some calculations, the LED's are all operating at reasonably low currents - either 1mA or around 0.5mA. So they will only light dimly, and from the datasheet develop 1.8V.

I'd start looking around D24, Q30 and Q31. These are current sources for Q4, Q5 and provide the current through the batteries. This current should be 1.8 - Vbe = 1.2V across a 240 ohm emitter resistor - or 5mA.

In addition if something is screwy with the circuit around D1, the biassing of Q4 and Q5 will be up the chute.

One or both of those could well put the battery into an inappropriate regime - if it is expecting 5mA and is getting significantly less for example (I haven't figured the circuit for the battery yet).

Er good luck - I'll be in the same place as you in around a month's time.