What the hell is this guy on about? wherever there is a three phase supply there's a single phase supply, you can only plug this amp into a single phase supply anyway, just another overselling sales gimmick!
The output stage has a 16A CEE power connection and runs on 3 phases and if desired also on one phase but then with current limitation and reduced power! Aber was soll man verlangen wenn Du den Amp noch nie in den Händen hattest.
