[Doh]

Does anyone have any impression of how the Gilmore sounds running at 20V?

How do I perform the adjustment? Do I simply replace the 500 ohm resistors on the board with 600 ohm resistors and dial up the voltage at the power supply via the trimmer pots? Are there any other parts substitutions I have to make?

Thanks!

 

[Arzela]

Dr. Gilmore chose +/- 16.4 volts
and the bias current since these
values were the "sweet spot" for the
trannies. Of course, you might prefer
the sound at 20 volts...

As far as changing the voltage, I think you need
to change the 22.8 K resister in the power supply,
this sets the output voltage.

Sorry I can't be more specific, this is what I rerember from reading
previous posts.

 

[Doh]

Ahh. Thanks for pointing that out. I missed it when I read the article. I think that the voltage will stay where it is.

 

[Voodoochile]

I don't think the OPA227s would like 40v running through them, either. They are bound to get fussy after +/- 18v.

 

[robo7]

Most amps would benefit from higher supply voltage.
You have to change the 22.8 k to 30k in order to get +/- 20V.

BUT, in addition to Voodoochile's remarks, the output quintet are quite hot and may not stand another stress, you have to reduce their current to keep power dissipation within safe limits.