Hi
I'm having similar problems with my WT-600 (essentially the same amp but an earlier version) and thought it might be useful to share info.
I run my amp in bi-amp mode with the high out going to a 2x10 and low out going to a 1x18.
the problem only occurs when playing at gig levels (all controls around 12 o'clock) but when the amp cuts out, it is accompanied by a [b]very [/b]loud pop from the 2x10's.
First thing I did was fit a new valve
I originally thought that the problem was with the left power amp, but I lose both outputs. I recreated the fault and simultaneously recorded the DI out signal, the waveform showed a very fast power spike, the signal recovers after a few seconds. this signal is taken post EQ. so I figure the problem is likely to be in the preamp section, or the power supply (which affects everything).
I'm currently waiting for a response from Eden. - if you like, I'll keep you posted.
Rob