I'd noticed a slight unevenness in my monitors, just a general sense that the center image had drifted a little to the left. My little radioshack spl meter confirmed that the left monitor was producing a little more volume, maybe 3db, particularly with test tones around 200hz. My first thought was that it was problem with the right monitor, but, remarkably, when I switched the speaker leads, the problem switched sides. By testing with other monitors and by replacing all the cables, I think I've pretty much isolated the problem in the amp. The thing that has me scratching my head is the frequency-specific nature of it. The right side of the amp is definitely coming up short between 200hz and about 300hz or so. At 100hz the monitors test out the same, and above 1K they test the same. Between 300 and 1K, I sometimes got a spread of 1 or 2db, but of course I'm not using the greated decibel tester. Does this make any sense? It's occurred to me that the frequency-specific test results might have more to do with the meter than the amp. Could one side of the amp just be falling short at some frequencies but not others? Thanks a million.