"Holy Grail". LOL. What an audiophile / tube enthusiasts cliche.
Through these two years since I have come into ownership of the Leben CS300XS, and lately the McIntosh C2300 preamp, I have tried more than a dozen pairs of 12AX7s, including without limitation the Sovteks, the Mullard 1950's AX7s, the Telefunken smooth plates and ribbed plates, Mazda, Sylvannia, the 1950's Amperex long plate "D"-getter, JJs, Gold Lion reissues and Miniwatts.
But ultimately, the three pairs of which clearly stood out from the rest, in terms of sound quality, IMO, are:
- Telefunken 803S
- Mullard 10M (gold plated pins version)
These tubes, though rarer than most other tubes mentioned above, can still be found on the market occasionally and I suspect many tube owners from the past still store them. They are particularly detailed and Hifi oriented - if you are looking for that kind of characteristics in 12AX7s, look no further.
So, what is the remaining pair? Aren't the Telefunken 803S or the Mullard 10M famous / rare enough? Yes - maybe less heard of than the above due to rarity - but this - IMO, is the TRUE holy grail of all 12AX7s. I came across them during the visit of a hi-fi audiophile friend. He was interested to listen to my Esoteric - McIntosh - Dynaudio system (see signature for details) and was happy to let me try some of his vintage tubes on my McIntosh preamp. He went all SS now so the 12AX7s to him is more for collection than real use. There is currently a pair up of these for sale on eBay, but the measurements are not very good. This pair is now very strong. Once plugged into my system, I know well that I won't unplug them from my McIntosh (well actually I did later as I wanted to try them on my Leben). While the 803S and 10M delivered great details and with the Mullards 10Ms being the widest bandwidth 12AX7s I have heard, they are in no comparison with these tubes when it comes to human voice and musicality. Nor does any of my previous tubes such as the Amperex could even compare with these for musicality (and the Amperex long plate D getters were known for this). So coherent and musical, not overly warmish but not overall Hifi - these are the tubes which I have been looking for my Dynaudio speakers. I would try it with the Leben one of these days, but due to rarity I would hesitate to use them solely for headphones.
Ladies and gentlemen - introducing the vintage Gold Lion B759 12AX7s - the true holy grail among all 12AX7s, and matched within 1% at above 80. As I said, there is a pair currently selling on eBay but its matching or strength is no comparison to my pair. If you happen to find a pair locally, don't hesitate - get them regardless of the price. They sound good. You will hear it. This - IMO - is the ultimate 12AX7.
I couldn't help opening up a bottle after being astonished by the improvement brought about by a tiny pair of tubes.
Edited by googleli - 8/4/12 at 12:32am