I posted this a while ago:
Here are my limited thoughts on the tubes I tried:
NOS Amperex 6922 PQ Gold Pin US Version White Lettering: Most expensive and the clear winner. Clean, detailed across the spectrum, great soundstage and depth
Amperex Bugle Boy 6DJ8 Holland White lettering. 2nd choice. Much like the above, except I found the high end a tad overpowering and distracting at times
HP (Amperex) 6DJ8 A frames Holland: 3rd choice. Too much low midrange.
NOS Valvo PCC 88: 4th choice. Not enought bass detail. Sounded a little too harsh for me after even 30 hours. According to Bill, these take a while to break-in, but are a good value.
EH 6922: These were the stock tube and I never gave them a fair listen to evaluate.