tube mic supply

[mfilter]

I need to build a few supplies for some 221b's w/ ac701's

Heater should be no problem, lm317 like Jakob's G7 I think

But for the 120V HT.....

How important is it to be regulated? I'm thinking tl783 but would that be a good choice with the mic only drawing a couple mA? Or an 0a2 and leave out the silicon?

:?

Michael

 

[neilium]

The OA2 gas regulator wil probably introduce some noise. You can bypass it with a .01uf 400v film cap, which will take out much of the hash. The important thing is that it will look cool and glow purple.

 

[mfilter]

Hmmm maybe I'll try both and see which works out best.

How about using two regulators, one as a current source after the regulated 120v to draw a constant 15mA? Would that make sense?

Thanks!

Michael

 

[gyraf]

You could just load the TL783 with a 2W power resistor in order to sink the 15mA needed for it to regulate properly..