Audio Horizon Pre Owners - Tube recommendations?


Greetings, Audio Horizon pre-amp owners. I know you're out there. ;)

I have one of Joseph's earlier models (TP 2.0 i) which I'll likely be upgrading soon. Shortly after purchase, I replaced the stock tubes with Amperex PQ White Label 6922s, and never looked back, running them for several years. Sadly, I've noticed a problem with some tubes (clearly failing in some manner), and have moved back to the stock EH tubes... which sound like crud.

I don't do much tube rolling, so I have a few questions:

- What have been your favorite tubes in the TP?

- Where did you source them?

- Is there any place where I can send my Amperex tubes for testing, to see how much life/power/mojo might be left in them?

I'm sure this question applies to any tubed gear. Even if you don't own an AH, I'm sure your input will be most appreciated!

I don't own an AH. I don't know what tone spectrum, if any, you are seeking. That said, of new production (cheap!) tubes, JJ 6922's are very good, but a bit on the warm side of neutral. On the cold side of neutral, and not quite as cheap you can get NOS 6h23's. You might also ask on the AudioAsylum Tube forum, there are some fairly knowlegable tube folks there who may help.
I owned a TP 2.0n fully modified to a 2.2 version and found the tube of choice for premium performance are Siemens CCa's.As I recall several other members of the AH fan club also tubed with CCa's and I believe that's what Joseph uses in his personal unit.
If you can't justify the exorbitant costs a quad of Siemens ECC88's also work well.
Thanks, Mark and Newbee --

Looks like Joseph is going to be sending me a quad of Siemens ECC88s to replace the Amperex.

I appreciate your input!