I see big musicians running multiple amps at one some times more then 5 or 6, how do you do this? I thought it was a line selector but some one told me you cant do that with more then three. Is there a special box for it or wire?
Custom Audio Electronics is your friend if you're interested in that many at once.
if you want to run that many amps at once and have some sort of switching system, you are probably going to have to either buy something custom or build it yourself. it probably wouldnt be too hard to design something to do that if you just wanted an on/off switch for each.