I've tried a few different el34 and like the Svetlana winged "c" very much. I will be trying the same tube cryo'd very soon and hope to squeeze out a little more performence.
I'll second the Seimens for EL-34's. As for 12au7's did alot of tube rolling with these and found Amperex 7316's to be the best. Has the speed and clarity of Telefunkens but not so thin sounding. Full midrange of Mullards but clearer and more detailed. By all means there are tons I haven't tried nor have I gone into the rare and expensive but for around $100 a pair (my limit) they are fantastic and worth the extra $.
electroharmonix 12au7's alway's seems to be, dollar to quality, a good buy. I use them and I think they sound just fine. Telefunken, if money didn't matter, would be my first choice.
I use Siemens EL-34s which I like a lot and have read a lot of good things about Mullards, EH, JJ, and cryoed Svetlana C wings. As for 12AU7s there are too many good ones out there, but Telefunken, Mullard and Amperex seem be to be the ones everyone talks about. I use NOS RCA from the '50s with the side getter. They are more reasonably priced and there is a better stock of them for easier matching.
I just bought some of those Mullard re-issues that New Sensor is building and am pretty impressed. There seems to be all sorts of trade-offs with different tubes. I am using them in an Audiomat Aprege integrated, which I find to be sort of a laid-back CJ sound with a tad more detail and bass oomph. I sourced the tubes from the tubestore and they were excellent to deal with.
As far as 12AU7,s I have tried a bunch of them in various Cary preamps. I kind of like the RCA clear-tops if you can find them. They used to be pretty cheap. I have not tried any of the Tung-Sol re-issues yet. They might be worth a try.
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