I even noticed that the placement of tube rings on the tube matters. If they are placed right in the middle of the tubes, they become too much of a good thing. But at the very top of the tubes, they provide a nice improvement. Although I didn't hear any drastic tonal changes, but separation, definition of instruments and overall soundstage clarity definitely improved. Dressing all the tubes in the preamp with Hal-O damping instruments doesn't cost much and I think it's a worthy improvement.
At least in my system it was.
At least in my system it was.