What tube pre-amps pair well with Pass amps?


Does anyone have experience with this?  I'm running Focal Sopra No. 2s and I understand the Focal's pair nicely with Pass amps.  Any tube pre-amps you'd recommend for consideration? I like the classical rock, but am gravitating more to jazz, classical and vocals. I just want to try something new.  Thanks.
billtro
When comparing Focals and any amp, pay particular attention to the mid bass.

They tend to be above-average demanding and therefore suppressing output this region. There's no right answer, you might like it suppressed, giving you a built-in loudness curve or matching better with the room.

Given this combo, old school CJ or Sonic Frontiers.
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billtro
What tube pre-amps pair well with Pass amps?

Many don’t work with quite a few Pass amps as many Pass amps are low input impedance, and a lot of tube preamps are high’ish output impedances
You need to look at output impedance v input impedance 1 to 10 ratio or more for good impedance match. Otherwise it can start to become a voltage divider and "can" squash dynamic impact as well as output level.

Cheers George

I've often wondered about this, for different reasons like the allure of tubes etc.

I'm run the Pass Labs XP-22, XP-17 and the XA60.6s with an analog front-end only. I recently put in a distributed bass array and altogether I'm blown away and quite happy. Yet...

Curiousity and interest got the best of me and I reached out to Pass. Here was their recommendation for tube pres: Atma-sphere, BAT, Conrad-Johnson.

I'd like to know what the OP decided to do. And any other continuing thougths.