I'll be the lone person how says off with the power! Unless you fancy replacing those hard to find power transformers and odd proprietary transistors that are in you amps, you might want to get comfortable with turning the power off. Of the transformers I've replaced almost all were in units left on to "maximize" the sound. TRUE, Amps will sound better after 20 - 30 mins . I've told more than a few people that unless they wanted to spend multi hundreds on a custom built transformer, their broken equipment would make a GREAT doorstop.
