Is tube "thunder" power related?

maybe...however, shipping may have also damaged the tubes...shook em up to much and they are failing....

I have found the tubes in this unit to be noisy by nature. Wright was kind enough to replace mine for this same reason. It is not a hum problem, but a "tube rush" sound along with some sputtering. Oddly, the new ones were also noisy, but sounded so much better that I didn't whine any further over it. The first pair by the inputs is where you want the quietest ones. try switching them around, but don't switch from channel in case they were matched pairs. 9 months later these tubes were very much quieter... can't explain that. If you really want to hear how good this pre is, run it directly into the amp without any line stage.A huge improvement. Anyone not wowed by this phono stage should try this. It is a whole new game. Impractical for a whole "system" though.