12ax7 tube recommendations for Croft Phono Integrated

You can also try GE triple mica black plates 5751 for a very detailed sweet sound and lower gain. Not great depth but a lovely black background.

I’m a huge fan of the Genelex Gold Lion for input tubes. I use them on my tubed DAC (12ax7) and on an Audio Research VT60 (6922) with great effect.

They are current production and readily available which is something that your component manufacturer will design around. They won't design for out of production tubes in mind. Also, if you like them you can get them again when/if they go bad.

I second the recommendation for Brett Jessee. He is a real straight shooter. Also, when it comes to NOS tubes, spend a little get a little, spend a lot get a lot. Buy one set of great tubes, don’t buy an assortment of mediocre tubes otherwise you will just end up with tubes you want to sell later.   And do ask about depth.  I have found the most detailed sound can be ruined by lack of openness and depth. 

I used 5751 in the phono stage - lower gain level but absolute velvet. Changed stock JJ with NOS Siemens really opened up mid range.
 Electro harmonix not as good, not tried NOS mullards but heard they are fab too ..... 

I posted further up but want to reiterate to help you guys out. I have been a Croft aficionado since the 80s. I have tried almost everything in these amps over the years. I strongly recommend new Shuguang Black 12AX7LPS from Grant Fidelity. They need 20 hours burn in. Detailed without glare, open, sweet as a nut, transparent, with excellent stage and bass. If you don't dig them, I will buy them from you (for a discount!)