I've had the speaker wires come loose and never had a problem. I also am biwired using two sets of cables and I have had one cable come loose that was connected to the bass woofer. I just reconnected it and it was fine. In fact, this is weird, but last week, I was playing my set and only one speaker was connected, as the cleaning lady accidentally knocked off the speaker wire connections to my right speaker. I was listening to music out of the one speaker for about 30 seconds before I realized one speaker wasn't on. I reconnected without a problem. I think it takes a lot more to damage a tube amp than a loose connection for a minute or so, at least in my experience. BTW, I have a conrad-johnson tube amp.
