Gthgmg, I would try a silver treatment to the tube pins, AC connectors, and RCAs. I had alot of luck with QuickSilverGold, but SST is very good as well.
It significantly increased the dynamics, but initially brightened the sound. The brightness disappears but the improved dynamics remained. It's a cheap enhancement. If you don't like the sound you can remove it with Detox and use some ProGold instead.
Be very careful though, you don't want to over do it.