Tubes Asylum: Re: BEST 12AU7 by robert

The concept of a "best" anything in audio, particularly tubes, is very wrong, there are really only good and bad, and among the good, many alternatives. Some will work for you and some won't. There is NO perfect tube, they all have strengths and weaknesses.

In the 12AU7, obviously the Telefunken ECC802S and Amperex 7316 are safe bets and everyone jumps in with them, not only because they are good tubes, but because they have been heavily promoted and hyped as "the best". I like them.
For far less money, and a bit of searching, here are a few others:

CBS-Hytron 5814A D-getter mid 1950's - every bit as good as the above. Perhaps not as tight in the bass as the ECC802S but warmer in the mids. Sweet but not sibilant highs. Quite warm but not bloated.

Tungsol 12AU7 early 1950's black glass - like the CBS above, not as warm in the mids, very sweet extended highs. Warmer than the ECC802S.

RCA 5963 1950's D-getter - fabulous tube if no more than 250v on the plates. Warm, great mids, nice highs, deep bass. A steal...

Raytheon 7730 late 1950's D-getter - a very distinctive sound. Warmest 12AU7 I have ever heard, but still clean with no loss of detail. Very big romantic sound. A little rolled on top compared to the Raytheon, but that's good sometimes.

CBS 7730 early 1960's O-getter - very much like the Raytheon, not quite as warm but a bit more direct.

Radiotechnique 6189/12AU7W early 1960's large straight plates - tight and warm. Great mids. Sweet highs, no match for the CBS 5814A, but still a great tube - but better yet (but dissed by dealers who don't have any) is the earlier Radiotechnique version with small staggered plates - very musical sweet romantic sound.

Raytheon 5814A D-getter early 1950's - might be my favorite 12AU7, makes the Telefunken ECC82 sound thin & weak by comparision, warm, deep deep bass, nicely extended highs with no sibilance, very musical.

A final oddball choice is the mid-60's Valvo 6067, which poitively stomps on the Tele ECC802S for tone and musicality, but I have very rarely seen them for sale.