I bought a Bugera 333XL about a month ago, and when I had it on the lead channel, there was a ridiculous hiss. So I patched my old RP200 into the FX loop as a noise gate, and that worked pretty good. Now, whenever I have the FX loop engaged, I get this weird volume fluctuation. Almost sounds like I've got a tremolo effect going on, but I know that's not the case. Any suggestions?
By RP200 I assume you mean the digitech RP200, which would probably be your problem, I had an RP80 at one time and it was a waste of money, I'd get either a noise suppressor pedal or check out the fullbore metal, it has a built in noise gate that I've been using and enjoy, but if you like your amp dist then the suppressor is probably your best option.