So, Thomas Mayer Differential 10Y, Allegri + passive, Vinnie Rossi L2, Berning ZOTL Pre One? Drums beating and beating,… then stop.

In my acoustically treated space, having the loudspeakers sing freely without anything between them, with all electronics on the side wall, the preamp's influence on the sound for the four mentioned is less than 15% to my ears which I regularly check. It is perhaps not fair to forget the subtle mix of character—I'm not allowed to use the word 'distortion' here, lol—between Nenuphar/Bakoon versus each of the contenders. Different pairings with other amps slightly changed the picture.

Anyway, what Thomas managed with his 10Y push/pull preamp is something that's probably closest to traditionally accepted perfection. Enough said.

Townshend's Allegri+ is a little guy only in physical dimensions. It produces a great soundstage with touches of eerie psych effects.

Berning's ZOTL is ruthlessly accurate. Maybe David's grandparents were German too?

Eclipsing lunar and stellar L2? Highly transparent, easy and fun to play with and with that one distinct advantage from the claimed and confirmed S/N ratio which produces this feeling of calmness which allows for no impurities. I'd conclude that for SET lovers, I'm certain that all four will provide a lot of satisfaction.

What am I going to do you ask?

Nobody could stop me now. I'm writing Vinnie asking him to sell me this L2. Yes, good evening to you. My name is Dan and I'm an addict!

PS. If you're curious about my extended playlist, here goes:

1. Au/Ra – Panic Roomlink
2. Grandson – Bury Me Face Downlink
3. July Talk – I've Rationed Well –  link
4. Rainbow Kitten Surprise – Cocaine Jesuslink
5. Alabama Shakes – You Ain't Alonelink
6. Regina Spektor – On The Radiolink
7. Mariza – Medolink
8. Rag'n And Bone Man – St. James  (Bluestown) – link
9. Koko Taylor & Willie Dixon – Insane Asylumlink
10. J.S. Bach – Easter Oratoriolink
11. Saint, Sahale – Dune (Buddha Bar- Armen Miran & Ravin) – link
12. Perfume Genius – Gridlink
13. Warp Brothers – Cokanelink
14. No Blues – Ya Dunya – Rageen Ramblinglink
15. Taraf de  Haidouks – Gipsy Lamentlink
16. E Lucevan le Stelle – Tosca – G. Puccini – link
17. Astrud Gilberto, Stanz Getz and João Gilbert – Corcovadolink
18. Csik Zenekar – Most Mulik Pontosanlink
19. Goat – Words (Commune) – link
20. Brian Jonestown Massacre – Just Like Kicking Jesuslink
21. Ane Brun – How To Disappear Completelylink
22. Timber Timbre – Lay Down In The Tall Grasslink
23.  Rachel Yamagata – Nobodylink
24. Willis Earl Beal – Too Dry To Cry – link
25. The Record Company – Turn Me Looselink
26. The Outlaws Blues Band – I Tried To Be A Good Boylink
27. Two Feet – I Feel Like I'm Drowninglink
28. Phildel – Dare (Disappearance Of the Girl) – link
29. Mercan Dede – Sufi Dreamslink
30. Jessie Reyez – Gatekeeperlink
31. Jason Ricci & New Blood – The Way I Hurt Myselflink
32. John Coltrane – A Love Supreme, P.2 Resolution  MCA Records – link
33. Miles Davis & John Coltrane – Teolink
34. The Jazz Singers – Franklin Mint Record Society  disk 6 face A
35.  R. Strauss – Also sprach Zarathustra, Deutsche Gramophon – link

PPS: I tried dozens of different tubes now. The L2 advantage is that one can micro fine-tune the sound character of the loudspeaker/amplifier interaction.

A: One needs a bit more resolution, more clarity, less "velvet and honey": go PX4, SV811, 183/483 (5V 45) or TAK 300B (last being borderline between A and C).
B: One needs a bit more soul and sexiness: 300B is the soul-ution (TAK, Elrog, Sophia Electric).
C: One is already balanced but longs for a bit more meat on the bones and presence: 2A3 and 6A3 are clear winners for me, with the JJ 40 coming out on top.

The L2 ⇒ Berning VT52 ⇒ Nenuphar combo in my room is really magical. The best sound you and I heard together back in the old room was less than 75% of what I'm hearing now. I purposely didn't mention speed as an individual character point because the OTL amp supersedes any such influence from the L2, being OTL-ightspeed itself.