Hi Guys, Thanks for all the suggestions, I trimmed the speaker cable ends more cleanly, I had more wire stripped than needed and the ends were slightly poking out, though red/black were not even close, however its possible the louder volume vibrated them enough so something might have earthed against the receiver body (just speculating).
Anyhow, after the clean trimming to just the required length, this hasn't occurred again. I was listening to On the Turning Away, Pink Floyd, heard it 4 times now and it hasn't occurred again.
