Joule electra Pre Amp -tube rolling

While it doesn't hurt to know what tubes a manufacturer chooses or what is recommended in equipment, ultimately, the user is trying to achieve a certain sound. So, saying which tube might sound better with which numbered tube is worthless unless at least some actual listening and comparing is done and then at least a hint is given as to the perceived tonal differences between the two or more being discussed. "So and so likes this" one and "I like this one" doesn't mean a single thing without an explanation as to why one is preferred and what it seems to sound like and ideally a reference given to another tube and the differences.

And those preference are also affected by the amp and speaker being driven. I agree with Clio9, I would stick with Jud's choices.

I'd still try an "inexpensive" set of Amperex 12AX7's to hear if you like the difference. In the Joule amps replacing the stock 5751's with Amperex 12AX7's gives a fuller sound albeit a tad less detailed. Jud bought what could get a big enough stock of which we don't have to do. We can hunt for small numbers of the tubes we like( it is getting tougher but not impossible). I think it's good to try rolling for yourself. I had a Calypso pre amp that most liked the Mullard CV-4004 '81 or one of the M-10's gold or steel pin. I used the CV-4004 until I tried an Amperex Holland 12AX7 and found it was a fuller sound that worked better for me, anyway you get the idea.