I bought an UltraBass 120 on CL. Played it about 2 - 3 hrs, all was good. This morning I had my Zoom B2 plugged into in (in the passive in), only at about 30% volume. Played fine for 20 minutes or so, then it started losing volume, down to zero over the course of about 90 seconds. All the lights come on, the light under the Ultra switch is still registering input signal variance, tuner jack still outputting to the tuner, just zero from the speaker. I pulled the B2 and went straight, nothing. Ideas? I am technically capable but ignorant on amps.