have you switched the monos themselves? sounds like a very odd problem to me. you might wanna check with deja vu if you haven't already.
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