Hey guys, for those that have a Herbert, is the volume in channel 1 lower than channel 2 and 3 at the same volume know positions? I've had some problems with my Herbert (losing volume and sound turning muddy after a few minutes of playing, especially after changing channels), after testing extensively (tubes, sockets, inputs, loops, cables) the sound has now stabilized with new power tubes and the original preamp tubes, except v4 because that one broke. I'm reluctant to switch preamp tubes again because I did a lot of swapping during the testing and it didn't solve the problem. Now at least the sound is stable I would rather leave it this way. But am wondering about the volume difference though.