master volume on Princeton reverb

[stagekraft]

hey all,

years back I had a Pro Reverb that a local tech had installed a master volume on, I guess his thinking was to overdrive the frontend without breaking up the output.

Anybody have any input, pros or cons, to doing this on a Princeton reverb?

regards
stagekraft

[jjman]

They have different PI’s than the Pro. Some say the cathodine won’t distort nicely. I have some post PI MV amps but none cathodine. Added components can allegedly mitigate some/all of the causes identified for the “bad cathodine clipping.”

You could seek to distort the 3rd preamp stage instead and place the master between it and the PI. Remove feedback, change the 3.3meg/cap values, increase the “mids” resistor. Of course many consider all of that heresy. I’ve done some of them to my Fenders so I’m a little heretical.

[Firestorm]

I can't see the advantage of a master in a Princeton. 6V6 tubes require comparatively less signal to drive them than 6L6s so you will be overdriving the output tubes before any other stage in the amp (unless you significantly alter the circuit). And you don't ever want to overdrive a cathodyne anyway.

[PaisleyTube]

maybe try one (simple MV) in front of the splitter like an early 80s SuperChamp.....

[tictac]

Like this...

[fabiomayo]

Reviving this thread. Can anyone explain the difference between tictac's schematic and this?
I was going to include VVR in my build but am now thinking of just having a MV to avoid the PÌ distorting and I think I like tictac's better.

[tictac]

The one I posted keeps the stock circuit intact when the Master volume is fully CW....

[fabiomayo]

I'm assuming 1MA for the pot. Is it right?

I'll give it a try...

[tictac]

1M or 500K...

either will work

TT

[jon]

maybe try one (simple MV) in front of the splitter like an early 80s SuperChamp.....

This works well