Hello again everyone,
Questions for all of you and Steve D if you can help. I have owned my VM combo for a couple of months. I have noticed that the effects loop is possibly causing problems.
When the loop is engaged with the switch on the back, the output level of the amp drops and there is a distinct rise in background noise. It is my unerstanding that even with the loop switch set to "engaged", if there is nothing plugged in the loop jacks, there should be absolutely NO drop in volume level. Is that correct?
I am finding that, as soon as I engage the effects loop, the volume drops and the background noise goes up. I tried bypassing the loop with a guitar cord - plugging just the cord from the send to the return loop jacks - and then engaged the loop. Even with a direct cable connection from send to return, the level dropped and the noise floor rises. A
Also of note is the fact that the selectable effects loop level control has no discernable affect on the signal level. For example, pushing it in and out with an effect in the loop does not change the volume level.
Question. Could this be a tube problem? It appears to be on the "return" side of the effects loop circuitry. Does the "effects return" signal path pass through a tube or is it solid state? If I can play around with a few tube swaps to test this out, no problem, but I don't really want to waste my time if not required.
Otherwise, if it looks like an effects loop circuit board problem, I will be raising a stink at my retailer for a new amp.
Suggestions?
Deputy Dawg