Master volume for a solid state amp.

[cav3man]

I have a Fender Stage 112SE that I love, but I share the common complaint that the volume controls, especially on the clean channel, are too sensitive. It's very difficult dial in anything below stage volume. The pot seems to jump from silence to too loud almost instantly, before it gets to 1.

I was thinking about about changing the clean channel volume pot to something that sweeps more slowly, but then I stumbled onto the master volume idea and liked it better. I would mount this to the back of the amp and not have to worry about messing with the factory pots that sit right on the pc board. I'm looking at schematic for the amp, thinking it would probably fit best after the Power Amp In jack, but I really don't know, and I don't know what would be best to use. I don't know a lot about different types of potentiometers.

All the info I can find on adding master volume seems to concern tube amps.

[pickles_man]

Ha! I just posted a very similar question re: a twin reverb. I don't have an answer for you, but maybe soon....

good luck

[Enzo]

Why modify the amp at all? You have a power amp in jack, so that means you must also have a preamp out jack. Your basic effects loop. Mount a volume control in a small box with a couple trailing cords or mount jacks on it and use a couple patch cords, and connect it in this loop. It will be an external master volume.

You could also just connect a common volume pedal there.

Or a lot of guys like a little EQ pedal in their loop to add a little extra clean gain for solos. You could just as easily turn such a pedal down for a little gain reduction instead.

[Steve A.]

Originally Posted by Enzo

... Or a lot of guys like a little EQ pedal in their loop to add a little extra clean gain for solos. You could just as easily turn such a pedal down for a little gain reduction instead.

I guess that we could call that a Clean Unboost- or would that be an Unclean Boost?

[cav3man]

Yes, I know I could do that, but I'd really like to have a master volume control on the amp itself. I see no reason why this would be any more complicated than building a separate volume control box, which I'd have to carry around separately along with a couple cables.

If I knew how to make such a box, I'd probably just try adding the circuit to the amp itself, but I don't know a lot about this stuff. I'm looking for something that would cut the signal level to .25 or less at the half-way mark.

[Enzo]

Wel i guess that was the point, a master volume is a master volume. I only suggested throwing it on the outside because it wouldn;t require modifying the amp in any way. it is just a pot, and you could just as easily wire it inside the amp chassis as outside in a box.

All a volume control is is a pot. Use a higher value pot like 250k or whatever you have. Wire the signal input to the top end of the control - the end the wiper scrolls to when all the way up. Wire the other end to ground. The wiper then is the signal continuing on the signal path you just broke into.

On your amp, look at the schematic on the right side above the power amp jack. We are looking at TP10. We would break the trace between pin 7 of U5B and that jack. COnnect pin 7 to the top of your control, and ground the bottom end. The connect the wiper to the remainder of the trace going to the jack. So we are inserting the control betwen U5B and the jack.

Another route to try would be to replace R59 - across U5B pins 7 to 6 - with a pot wired as a variable resistor. A 500k pot maybe.

One might be able to remove the preamp out jack - if you don't use it - and use the hole for the control. And you might get away with wiring a pot across that jack's board pads as a variable shunt. C38 ought to be relatively transparent to signal and that might work. Try that. Plug a cord into the Preamp Out jack, then clip a pot wired as variable resistor from tip to sleeve at the other end of the cord. Does it work as a volume control? If so, there you go, mount it inside.