Tube Rolling - No Change in Sound

I rolled 6922's and experienced little change; however I rolled some 12au7's and experienced dramatic change. They were NOS 50's vintage, this was in a CJ.

Thanks for all the comments. I am not sure I am any more illuminated than when I began, given the diverse views, but I suspect the observation that the pre may not be sensitive to tube-rolling may be the most accurate -- at least with the KenRads. (FYI, my amp is a Krell FPB 300cx.)I wonder if more extensive burn-in (these are NOS tubes) will effect a change. Time will tell.

Thanks again.

Neal

Ken-Rad VT231 has been known to deliver excellent bass and sweet mids. Sounds like you didn't get any of that! Well, at least, you will probably be able to easily sell them.

Sure sources (and preamps) affect sonics, but with them, it's basically "what you buy is what you hear" -- they are what they are. The reason the amp+speaker=primary system sonics is because:
A. Once a signal is created (by a source) the amp processes the signal (multiplies it by a huge factor) more radically than any other device (even including equalizers!) A line preamp (not a phono preamp) is really a signal switcher + a buffer stage; it selects a signal (source) and then optimizes it for driving an amplifier; but it doesn't really alter the signal that much; not compared to an amp!
B. The speaker (and the speaker/amp interface, AKA how much the amp likes the speaker it's driving ;-) is the other major factor that determines a system's sound character. Don't tell me about the room treatments, and the cables, and the temperature and the altitude ;-) they're all important. Nevertheless, you can do anything you want upstream, but horns, stats, cones, domes, ribbons, buttons and bows! each have their own unmistakable sonic character -- and you can't make one sound like any of the others (not by any legal means ;-)
.

I don't know if I agree, in my system amps have made the least difference, speakers the biggest difference by far - then source followed very closely by preamp and lastly amp.

I do agree without question the amp/speaker interface has to be optimal or close to it or you can throw everything out the window.