Kondo, Zanden, CJ, Ref 5? Pre w/ Pure Tonal Color?

Hi A'Goners! Happy New Year! I am looking for a no-holds barred (second-hand) preamp that can (at least) maintain the transparency, detail, speed of my CJ ACT 2 but really add dramatically more tonal color, purity, harmonic richness.

My system:

Oppo BDP-83 (Upgrade Company modd'd)
Zanden 5000 Signature DAC
CJ ACT 2 Pre (Series 1)
Gryphon Antileon
Wilson X-1/Grand Slamms
Velodyne DD-18 (in parallel...from 35hz downward)
Transp Ref IC/SC
PAD Dominus/Ann Contego & Sablon Audio PCs
Transp Ref Power Conditioner
Nordost QX4

For background, i used to own SF Strads, and have owned Guarneris and CJ equipment for years...but i recently upgraded to the one speaker i have found in 25 years which i preferred. The Wilson X-1 Grand slamms...which far surpasses the Strads in soundstage, dynamics, detail retrieval and rhythm...as well as bass. And I have found it can be intensely musical...when set up right. (super-sensitive to set up.)

With the Wilson's in, my system today is as musical now as it was with the Strads...but i find with the immense increase in detail, soundstage, bass, rhythm, spaciousness, etc...i feel like if i could find a way to add some additional tonal color to the sound...it might go even one level further!!! (As always...a never-ending pursuit!)

i know many feel Pres should be straight wire and gain. in my case, i think the ACT 2 may be "losing" some color along the way. In particular, i think that my Zanden and Gryphon are quite warm with good tonal purity...and i have read that the ACT 2 compared to some well-regarded Pre's is a little too neutral. (hence why the Series 2 came out quite quickly...within less than 24 months).

thus, i am thinking about changing the ACT 2. Here is my current shortlist...but i am truly open-minded:
- CJ ART 3
- CJ Act 2 (Series 2)
- Audio Note?
- ARC Ref 5

These would all be second-hand and therefore "do-able"

meanwhile, for the right deal, i would also look at:
- Wavac PRT-1
- ARC Ref Anniversary
- Kondo M-10

I MUST hear them for myself in my system...i always keep my own counsel. but it sometimes helps to get the benefit of other people;'s experiences to at least draft my "shortlist" of preamps. I have focused on tubes...but if SS gets you there, say so!

Thanks for any guidance!

Lloyd