I just bought a spider valve head and went to pair it with the cab I have from my spider 4 half-stack and I am getting some seriously weak distortion. The volume is loud, but my spider 4 had WAY more umph, and that shouldn't be. now, the cab for the Spider 4 has a funny left/right configuration, and I'm admittedly new to valve amps, but the tubes all seem to be in good shape. Anyone ever paired this head with this cab?