I had a JMP-1 that I sent in to Trace at Voodoo Amps to get a mod to reduce the loud noise that I was hearing from the unit.
It comes back and the noise was even louder.
I had called Trace and we tried to problem-solve the issue.
One issue was the mod increased the overall gain on the JMP-1 so every gain level needed to be turned down a LOT on the JMP-1.
The second issue was the room where I had the JMP-1 set up.
The ceiling lights were causing the noise.
I had moved the JMP-1 to another room and it was dead quiet.
I wouldn't have sent the JMP-1 to get modded if I had known it was just the ceiling lights causing the noise
I had purchased an amp this summer that was making loud pops while I was switching the channels with the footswitch.
The seller suggested cleaning the end of the power chord and the electrical outlet.
I had cleaned the end of the power chord and tried a different outlet.
The loud pops disappeared.
Most people don't really think about the way electrical current passes from our homes to our gear (I find it interesting (and frustrating) that not all outlets provide equal quality).