Herron VTPH-2 12ax7 Recommendations?


My new VTPH-2 is breaking in nicely. Tough to say I've ever heard a better phono pre and I've heard (and owned) a lot of them! I've got the version with 2 12ax7s. Any suggestions from other Herron users for NOS?

dhcod
Buy a pair of good used and matched Telefunkens and compare. If no likey, resell.
@dhcod 
@bdp24
I use NOS Sylvania Gold Brand 5751s in place of 12AX7s in my Herron VTPH-2 with no problems at all - to my ears they are a better choice in most circuits than the 12AX7 (smoother, better balanced, slightly warm) and the difference in gain has never mattered to me as I already have more than I need. I have also used NOS Tungsol 5751s in the Herron and found they accentuated the bass in a way I like (both more of it and tighter) but haven't been able to get hold of quiet ones. People will say that this is changing how Keith wanted the unit to sound, but so what if you find you prefer it that way and anyway, it's both fun and informative to experiment, if you can afford it. I bought my Herron secondhand and it came with cheap nasty 12AX7s of some brand I don't remember, hence I experimented. In general, with the exception of the increased Tungsol bass, I have not found a huge difference between various alternatives in this circuit. 
Thanks ochremoon. In the 80's I had the Frank Van Alstine Super Pas in which he used 5751's (Sylvania, if memory serves) instead of 12AX7's, for their linearity and low noise said Frank. I had Keith send my VTPH-1mm with two 12AX7's and two 12AT7's in order to get the lower gain and higher overload margin that combination affords. I use a very high output cartridge (5mv!), so I don't need the gain. I believe I'll audition a pair of 5751's in place of the 12AX7's myself.
Went ahead finally and bought from a well reviewed seller on eBay a matched low noise pair of Telefunken 12ax7 smooth plates. I'm not sure how it's possible to make such a great phono pre better but somehow these tubes do. It's just more of everything that the Herron is so great at: tonality, soundstage, dynamics. I'm sad when the day is over and I can't listen anymore. 
One thing though, the "matched" teles were not so I’ve had to adjust the balance on my VTSP to 1 o’clock. Keith says no sonic penality, but it makes me nervous....