Whats the best and quietest 12AX7 tube

You've got to test listen for compatibility between various 12AX7s and the other tubes they're sharing space with in the preamp. But, try the Ei Yugo 12AX7. It is very inexpensive, and you might find it has a very musical balance too. It is also as quiet as any 12AX7 I have heard.

I'm sorry,I should have made an update a while ago.I bought a Tungsram 12AX7 super low noise.It quieted the phono to better than acceptable levels.Well,this got my mouth watering.After consulting with Albert and Kevin Deal I replaced all the tubes in my phono section.The Tungs went back to Audio Advisor.Kevin sent me 2 Telefunkin 12AX7 and 2 Radiotechnique 12AU7.These are very similar to Bugle Boys.The line stage has G.E.s which are fine.My mouth was still watering so I bought 4 Svetlana EL-34 for my Dyna.I replaced some very boring Sovtek EL-34 Gs.My Phono is almost as quiet now as my old Lehmann Black Cube was and sounds absolutely awesome!!!

I agree with Opus88. The EI 12Ax7 is a very fine tube and can even compare equally or favorably to a Telefunken 12Ax7.

The best 12AX7/ECC83 is without doubt, the BRIMAR. Period.

I like old Telefunkens with the diamond bottom. The Tesla or EI (basically new telefunken flat plates-factory was blown up by Nato last year) are nice too, for new tubes. In my opinion the Sovteks are dark, too high in gain and boring. The telefunkens seem to be the most balanced across the frequency range and let the music shine-rather than displaying frequency aberrations