I really like the GE 5751 NOS. I use it in my ASL headphone amp. This tube is a direct replacement for 12AX7. For new 12AX7's try the Tung Sol. (very good for the price)
23 responses Add your response
You need to be careful with using a 5751 tube in place of a 12AX7. The 5751 has only 70% of the gain of a regular, typical 12AX7. These work GREAT in some gear, but it really depends on the circuit design. If they will work, they are indeed excellent tubes.
For new production 12AX7 tubes, I have used and really like the Mullard reissues and for a little more money the Psvane 12AX7s or the Sophia 12AX7s.
With a tube phono I really like the Sovtek 12AX7LPS tubes and the newer Mullard CV4004/12AX7 tubes.
With a Jolida Tube DAC 2 I really liked the Genelex Gold Lion 12AX7 tubes.
In my Jolida amp my favorites are the JJ 5751 tubes, and Ruby 12AX7AC7 HG+ aka TAD 7025-S and Preferred Series 7025.
Sorry if I'm confusing you. I enjoy all of these tubes and haven't had issues with SQ, build quality or endurance. A majority of these tubes were purchased via Doug's Tubes, Jim McShane and Upscale Audio. That may be why I haven't had any issues.
Tube rolling has one problem from sonics: It will show YOU what it can do in a given unit, with a given design, with a given layout, with given tube sockets, with the output range of a given preamp and so on. Change the unit and you can start all over again. Too bad for those who desperately look for the one and only super tube :-)
Anyway, my vote is for Psvane 12AX7 treasury series. Excellent performance for their price (compared to NOS, which are normally not NOS).
I'm not looking for the one and only super tube.
Fortunately with the prices of many of the recommendations above it's actually possible to roll a few without going to the poor farm. The great NOS stuff can be difficult to find and expensive, getting more so all the time. I've seen some of the great old 12ax7's approaching $1000 a pair. I have some NOS tubes but was looking for something a bit more down to earth and realistic.
No one mentioned Sophia or EAT 12ax7's. The EAT's are very pricey for a new tube but some reviews I've read rated them highly. Hard to find information on the Sophia's.
One thing for certain, there are a lot of new (non-NOS) 12ax7's currently available although most are probably coming from the same factories but with different names and different quality control standards.
I agree that the sonic result is dependent on the context and application. I have had good luck with and enjoy JJ, Sovtek, Genelex and Telefunken in a variety of applications, power amps, pre amps, phono stages and guitar amps. It all depends, which is why rolling to find what is good in a given context is de riguer.