Herron VTPH-2 12ax7 Recommendations?

Speaking of the Herron phono amp and 12AX7 tubes.....the 5751 tube is said to be a 12AX7 substitute, a military grade tube with slightly lower gain than the 12AX7. Does anyone have experience with the 5751 in a circuit designed for the 12AX7?

When I had my Octave V70SE then later the V110 I had used the RCA triple mica black plate in place of the 12ax7 input with great results. It was a warmer overall sound. Of course I did get the OK from Andreas Hoffman at Octave. He also said for those integrated amps 12au7 could be used in place of the 12at7 driver/splitter tubes which is also a lower gain.

That said I would contact the manufacturer and ask if changes like those will work. Some manufacturers design allow for flexibility while other do not. 

dhcod-Good call on picking the Herron. I've had mine for about 3 years and it has served me well. When I got it, I asked Keith about tube rolling. He felt that he had selected the best available tubes that are in production. When I asked him about vintage tubes he said there were lots of options and wished me luck. I have tried Telefunkens, Bugle Boys, RCAs and GEs. I settled on GE grey plates from the 60s for all tubes but V5. I left V5 stock which I think is EI. Vintage tube aficionados will likely snicker at my GE pick. I like them because to me they sound like 60s US audio which is at the roots of my love for this hobby. YMMV but I agree with others to let the phono stage fully break in before you start rolling.

Thanks everyone! I did speak to Keith and he kinda said what he said to you.... which is why I was asking for suggestions. It seems like at some point towards the end of the year, I might just invest in a pair of smooth plate Teles and give them a listen. Mine is the lower gain unit... two 12ax7s, so it’s less of an investment.

Thanks for all the suggestions.

I feel like I have to say again how truly fantastic the VTPH-2 is. If you are in the market for a phono stage, even if your budget is twice the $3650 it costs, make sure you listen to one!

Also Herron's customer service is second to none. That make a huge difference when you are buying something at this level.