Sushi-
First, thanks for the advice I will separate l/r channels when I get home.
However, I have my doubts that this will improve clarity (as opposed to sound stage).
On a tangent - I think the senns are a good reference: they easily allow a/b comparisons (volume adjustment is unnecessary with a headphone amp). And they sound the same in all rooms. You can also bypass some exotic stuff in listening rooms by plugging in directly. I always bring them with me when listening to new gear.
I don't think the issue is whether the senns or grados are too bright, to some extent that is a matter of preference (and hearing loss - god forbid - they don't sound bright to me - am I going DEAF!), it sounds to me as though there is some clarity/articulation missing from my setup. With the senns you can almost hear the mechanics of the harpsichord; the full range of the string being plucked is audible. With my other set up, there is simply less to hear.
Anyway, my dissatisfaction with the current sound can't really be done away with by saying that the senns aren't comparable. As Duke Ellington said, "If it sounds good, it is good." and the senns sound much better right now.
