I ran into the same problem with Vu's 300b push pull amps...required rebias of both amps at his lab. that was 9 years ago. Amps still going strong...
mono amps one weaker than the other ????
i have a pair of high end mono amps from deja vu and after about 2 hours the soundstage moves distinctly to 1 side, i tried switching cables, sources etc... but nothing else at this point, question could a weak tube work good for a couple hours then show a decided loss of output or does this sound like something more thanks in advance
Joe
Joe