I used it on the amp, and it did sound good. But after a very short time, the right channel got scratchy. As it is a sealed unit, I could not use it anymore, and moved on to a stepped attenuator. Even the tolerance was not god, so at low volumes it was a pain. Maybe I got a bum unit. I think it was Eli or Steve E who said that you could open it up in some thread, which I am unable to find. But, while it lasted, it did sound good. Takes about 150 hrs to break in.
shreekant