I swapped out the tube in my Bellari VP129 for tube that came out of a Prima Luna. Huge improvement. I may consider upgrading to an even better tube in the future...
Tube Rolling In Audio Research Phono Preamp
I have an Audio Research PH3SE phono preamp that currently has three Sovtek 6922's. Audio Research told me not to bother doing any tube rolling because it will change the "voice" and tone of the preamp. However, I keep reading wonderful things about vintage tubes improving the quality of sound in all kinds of gear. I was wondering if anyone has had any experience with different tubes in their phono preamp and which ones they liked the most. Thanks!