Solid State or Tube Preamp mated with Tube Monos?

Thanks for the response Jaybo. The Threshold output impedance is less than 100 ohms; while the Wolcott input impedance is 250,000 ohms. The specs -- given some say that the input impedance on amp should be at least 10X the pre ouput impedance -- seems to mate pretty well. Moreover, the sound of the pieces together seem to approach perfection to a closer degree than other tube and solid state setups we've had. Thanks for your input.

What other preamps have you tried?

Pubul57: Going back nearly quarter of a century, I experienced the following evolution in preamps:

1. Superphon Revelation (S.S.);
2. Counterpoint SA-1000 (Hybrid);
3. Counterpoint SA-5000 (Hybrid);
4. Audible Illusions Modulus 3A (Tube);
5. Threshold Fet 10Hl (which we currently use in 2nd system);
5. Threshold Stasis R5 (in our reference system).

I would say the Thresholds and the Counterpoint were the best of the lot to experience.

I've auditioned in-depth to many preamps in and around New England, some of which were the

1. ASR Emitter w/ Battery Supply/ies;
2. McIntosh;
3. ARC Reference;
3. Krell;
4. Atma-Sphere;
5. Audio Note Kondo;
6. Conrad Johnson;
7. Atma-Sphere;
8. Meridian;
9. Cary;
10. Aesthetix;
11. Sim Audio (?);
12. Ayre (?);
13. Spectral;
14. Linn;
15. Mark Levinson;
16. VTL (?);
17. Sim Audio;
18. Jadis (?);
19. Air Tight (?);
20. Classe;
21. Halcro;
22. Boulder 2010.

There are perhaps some others over the years that I can not vividly recall.

Thanks and happy listening!

? = vaguely recall listening.

Sounds as though you have not only have searched out many options, but are for the most part, are pleased with what you have. But I understand, change for change's sake, although sometimes not listenening for several days is also a nice change and a reminder of how good your sound is when you come back to it.
That being said I'll offer up this because I owned the P220's for a couple of years and loved them. For me they excelled in inner resolution, and because of that I at ist ran my AA Capitole Mk.II cdp direct and than used a
Placette passive which was a nice improvement.
Have you tried or considered a passive?; Music First or Bent Audio or either the passive or active Placette?
Might offer a little bit more of what your system is capable.

Somut, of course I recommend tube preamps over transistor as being more musical :) but whatever you've heard in the past, keep an open mind and for best results audition the preamp at home with your gear rather than anywhere else.

Happy hunting!