I started playing my Bongo through my GK 1001RB-II and 410SBX rig this morning, making sure to keep it low, since my roommate was sleeping, but I noticed a low fuzz/distorion beneath the clean, amp sound. Almost like a distortion pedal sounding fuzz, but very low. I tried switching instrument, and speaker cables. Nothing. I took the bass to a local shop, and it sounded perfectly fine. I brought it home, and began messing the with the EQ. I set it flat. The same. So I know its the amp, but I'm not sure if its the cabinet or the head. My guess is the head. Can anyone give me some advice on where to go from here? I'm wanting to avoid taking it to the shop, if possible. Anyone got any troubleshooting tips?