It's a Markbass 1x12 Combo where the head sometimes works and sometimes doesn't. Basically, I'm looking for a small-form head to power the cab. When I do play bass, it's often outside and without PA support. The Markbass (with 300w at 8ohm into 1x12") kept up JUST FINE. So -- I'm thinking that for $250 at Sweetwater and for however long it lasts, the TC Electronics BQ500 will be perfect.