Alright so I might be getting a used JCM 2554, silver jubilee 1x12 combo amp. I was thinking, is it possible to control Clean/OD with the volume knob or will I have to turn down the gain on the amp if I want to do so?

You should be able to, maybe not if it's dimed, but otherwise I'd think it would work. You could also try a volume pedal if you don't like to futz with your volume knob or you don't like the sound when it's turned down.
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may i add that higher quality/better taper knobs can help with this.
Quote by patriotplayer90
Lolz that guy is a noob.

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