I'm back!
is there a schematic for building a simple Zen-style preamp? the CSP3 is much more than just a preamp, but I can't find anything about that either. I would like to build myself a preamp to match my Zen Triode, something simple but well sounding, like a ZTpre even unbalanced. Who can help me? I own a preamp that I built myself several years ago using two 6SN7GT in cathode follower who piloted the power amp very well with the 300Bset, but if I combine it with Zen it sounds worse ... and having read on the forum how happy people are a ZTPRE with the Zen Triode, I'd be happy to build it too.
Thanks for those who want to help me, and for your patience.

thanks Brian, I think your thoughts coincide with mine ... for sure the input impedance of the Zen Triode is different from the Triodino 300B but unfortunately my preamp has no output transformers. It is coupled to the power amp only via a capacitor.
I would be so excited to build myself a CSP2 with no headphone output but I can't find a schematic. Meanwhile, I've been looking for a 6N1P-EV for my Zen Triode to replace the E88CC Philips Special Gold. I'm sure it will change the sound for the better, even if it's already exciting now ...  ;)

Would this work?
https://www.decware.com/newsite/diy/decware/ZKIT4.html

Hello Enrico,
Don't forget the 12b4 preamp. There's a huge amount of info available out there. A single gain stage ( around 6-8 IIRC ), an output impedance of 1K with no cathode follower in the mix. Noted for extreme transparency, it would not muddle the sound of your amp. Just google up " 12b4 line stage " and you'll have no shortage of reading material.

Cheers,                 Crazy Bill

Thank you, Lin for correcting me on the impedance matching.
Brian