I was lucky enough to snag a GK 400RB for cheap, and I really like the way it sounds but it's really quiet. I use an active bass so naturally I engaged the pad which is supposed to be -10db but I can't any volume out of it. I tried messing around with the preamp volume knob, and when it gets almost to the end there's a huge jump in volume, so the head goes from quiet to thunderous. Thinking there might be an issue with the pad I disingaged the pad and turned the preamp input volume way down, to like 2. Even at 2 the head is substantially louder with the pad disengaged than the with the pad engaged and the preamp knob at 10 or so, so I'm thinking there's something going on with the pad. I plugged a passive P-Bass into it and it's way louder on the passive setting than my 18v active bass on the active setting. Edit: the boost knob is at 10 o'clock on both tests So I have two questions: 1. Is it okay to run the amp with the pad disengaged and to use an active bass with the preamp volume lowered (I'm pretty sure it is, I'm not getting any distortion)? 2. The guy I bought it from switched the footswitch jack and the input jack because the input jack was a bit wonky and he didn't use a footswitch. Can there be a problem with this, are they two different parts? Might it have effected the proper functioning of the pad?