[jkm]

So, you're saying that you pretty much switch the "right" (bad) channe with the left speaker cables and its fine? does that happen then to the "Left" (good) channel, meaning when you do the switch, does the left now go bad?  What speaker cables are you using and if you switch the i/c, meaning taking the right out of the right amp and plugging it to the left amp and vice versa, what does that do?  Could be a phase problem in the speaker cables....hard to say, but if switching the speaker cables solves the problem, then its not the amp...or I don't think i is, anyways.
Sonny

When I switch the speaker cables the loud buzz switches from right to left. Whe I switch the ICs, the loud buzz still comes out of the right speaker.

[Sonny]

When I switch the speaker cables the loud buzz switches from right to left. Whe I switch the ICs, the loud buzz still comes out of the right speaker.

tell me how you're switching the speaker and interconnects.  Start with switching at the output end, meaning keeping the end at the amp constant...what happens then?

[jkm]

When I switch the speaker cables the loud buzz switches from right to left. Whe I switch the ICs, the loud buzz still comes out of the right speaker.

tell me how you're switching the speaker and interconnects.  Start with switching at the output end, meaning keeping the end at the amp constant...what happens then?

Sonny, I've tried this all kinds of ways with the same results. Tell me what to try and why and I'll do it.

[Sonny]

When I switch the speaker cables the loud buzz switches from right to left. Whe I switch the ICs, the loud buzz still comes out of the right speaker.

tell me how you're switching the speaker and interconnects.  Start with switching at the output end, meaning keeping the end at the amp constant...what happens then?

Sonny, I've tried this all kinds of ways with the same results. Tell me what to try and why and I'll do it.

Well, what I am trying to do is isolate it to see what the problem is, if its the preamp, amp or cables.  I just am curious as when you switched the speaker cables, it went away from the right to left.  Perhaps its the problem with the speaker cables, I think, the cable might be out of phase, meaning that the red (positive) on one end of the cable is somehow switched at the other end, therefore when you plug the cable from the amp, it switches from red (positive) to black (cold) and this can do it.  
I would first try to switch the interconnects from the amp to the amps, then the speaker cables from the amps to speakers.  but only switch the output end...first...
see what happens...