From my perspective, the troubleshooting list is the same, though I would also try and play with speaker toe-in/out. Also, is the plasma sitting between the speakers? I couldn't tell from your description. They can really brighten things up. I don't know if you can possibly drape something over it during listening sessions.
Otherwise:
1) ICs
2) PCs
3) Plug amp directly into the wall
4) McIntosh MC402 & possibly tube preamp (unless running direct satisfies you)
Thank you for a thorough explanation. It's much easier for the crowd to make suggestions when we can fully understand the factors at hand. Best of luck, and please post how things resolve for you.
Otherwise:
1) ICs
2) PCs
3) Plug amp directly into the wall
4) McIntosh MC402 & possibly tube preamp (unless running direct satisfies you)
Thank you for a thorough explanation. It's much easier for the crowd to make suggestions when we can fully understand the factors at hand. Best of luck, and please post how things resolve for you.