Hello,

      I just acquired a Spider II HD150 head and I am having an issue with the volume significantly dropping while playing. I am connecting the head (8 ohms) to an Ampeg slant cab (16 ohms) using 2 speaker cables to each jack. When I first power it on, it sounds great. But after playing for approx 5 - 10 minutes, the volume will drop. If I have the Master volume up around 3 or 4, the drop basically silences the amp completely. When this happens, i will crank up the Master pretty high to allow the jams to continue, but at some point, the amp will regain its power and almost blow my head off. Very annoying! The amp will maintain its volume for a short period of time, but eventually it drops again. I have replaced the cables to no avail. Anyone have any thoughts as to what might cause this to happen and if there is anything I can do to fix this issue?

Thanks in advance for your help!