What tube amp to drive Guarneri's?

What do you mean "add" a tube amp?? Play the two amps in parallel?? Or one tube amp for full-range?

If the latter, and having tried a few -- but obviously not all -- tubes the only model that sounded OK was a KR sporting one big 611 tube/channel. Dunno what it;s called, but it's distinctive.

Why not stick to your Rowland?

If it sounds "great" why switch?

Guess I should have elaborated on "add". I am going to keep my Rowland since the amp is so good and I want to swap out with a tube amp to get tube sound vs. the ss sound of the Rowland.
The Rowland sounds great but like all ss amps, I am fairly sure that it does not sound like a tube amp and apparently the SF's like tubes.

Actually, that vintage of Rowland sounds very similar to a good tube amp. I ran the Model 6's for a few years, which share the same basic circuit as the Model 8, and on both Revel Salons and Vienna Acoustics Mahlers, they sounded uncannily like my VAC Renaissance 140/140 Class-A biased triode tube amps run with zero feedback. What was surprising is how well the Rowlands layer space, which is usually the domain of good tube equipment.

I used to own the Guarneri and drove them at the time with the Welborne Apollo II single ended amps. They produced 18-20 watts. The combination was pretty awesome. I would think a good single ended 845 amp would work. Something like a Komura 845 or Sophia Electric 845, or even De Havilland 845.