sometimes i tend to here scratchiness/crackling on the EF86 side, idk if that's the best way to describe it so we may not be on the same page, basically as the EF86 channel distorts it gets a little scratchy and rough around the edges, almost similar to a solid state clipping? i'm running a cheap electro harmonix tube for the EF86 and wonder if that could be causing a weird distortion, or could it just be a bad pot or other similar issue anyone else is having?

i do know what you mean with the master volume, i have that problem too, and I'm sure everyone does. but yes, it does this in full power as well, and only on the ef86 side, i might just try popping in a tube to see if that's the problem, i wouldn't be surprised if that's all the problem is.