So I was looking to upgrade my bass rig but am a little tight on cash as of now. Right now I have a Rumble 150 that I was hoping to connect to some old PA speakers I have. I was wondering if I could connect the direct out on the combo amp into the old QSC power amp and then into the PA cabinet. So the idea is to have the 150 combo powering itself, but the preamp effects would go through to the QSC head. Anybody think this would be plausible?