Hey all. Looking for some advice. I know very little about amps. My GK 1001rbii is in the shop. It looks like the power amp is out. Amp sounds great when I run bass into the GK input, out of the effect loop send, into the effect loop return of my fender rumble. When I run it as normal (outputs at the back into cabs) it fades in and out and sounds super nasty. When I described that to the repair guy, he said it was likely the power amp, and estimated anywhere from 75 to 200 bucks to fix. He also mentioned that I could just use a second amp to power the cabs, and that a cheap one would do. What should I do, mighty gods of thunder? Should I get my amp fixed? Should I just use a slave power amp, which would probably mean another piece of gear to worry about? Any advice is appreciated.