Hello I wat to add à master volume on my peavey nano valve, here is the block diagram, I guess I should add a LOG varistor, but how can I define the Ohm for it, and also where should I put it ?
Most amps do well with a MV of 1MA, but 500KA might be fine too. As for where to place it, the schematic is required.
If your goal is to crank the input for more distortion without the amp getting too loud, a MV might be fine. But if your goal is to keep the fully cranked tone at a lower volume, a VVR might be a better choice.