post phase inverter master volume

[isaac_teller]

Hello. Is it possible to use a single-gang 1 Meg pot as a crossline master volume on a fixed-biased amp or does it screw up the bias? Thank you.

[sluckey]

Hello. Is it possible to use a single-gang 1 Meg pot as a crossline master volume on a fixed-biased amp or does it screw up the bias? Thank you.

You can safely do that. I bet you wont like it.

[d95err]

I agree with Slucke; it’s simply a bad circuit (fixed or cathode bias).

In my experience, it has a really bad taper, like an on/off switch, even with a log pot. By the time you start to notice any significant volume reduction, it’s also cutting so much bass and introducing other unwanted artefacts that the tone is unusable.

Find a demo of a modern AC30 where they’re running with the crossline master way down and you’ll see what I mean.

Other people may have better experiences though.