I'm listening to two amps I have, a Sherwood S-7100A and an NAD 3020, on a pair of AKG K240 Monitor headphones. EDIT: I also tested this using a loudspeaker switch to switch between the two amps, in a blind test. The NAD definitely has a cleaner sound, and vocals sound very well rounded. But the stereo imaging of the Sherwood kicks the NAD out of the park. When I look under the hood, I think I have a clue as to why - the signals for both channels are handled by physically separate boards on the Sherwood. So I was wondering whether there are any minor alterations I could try to make on my NAD that might improve the stereo imaging? E.g., bypass the balance controls, adjust the bias or something... I should mention that I recapped it recently and while it sounds great, maybe there's something that should be calibrated after? Thanks!