What tube amp to drive Guarneri's?

My current amp is a Rowland Model 8 with choke. It drives the SF Guarneri's very well and sounds great. However, I would like to add a tube amp that would compliment the speakers, what suggestions?
If it sounds "great" why switch?
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?
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.
Have heard them in a showroom with Air Tight ATM-2 amps and it sounded extremely nice.
Tmiddle, do you remember what other equipment was being used with the ATM-2's?
Also, what kind of music were you listening to?

Chris, I am a little surprised that you fed your G's with only 18-20 watts, since my Rowland at 250 watts is working to drive them, although I suspect not too hard. My room is very small, is yours?
I remembered the KR enterprises amp model: It's a KR-"Kronzilla" using of course a 1610 tube (not 1611).

It's a SE with ~25W/ channel. They also have monos (~40W/channel SE) which the Guarneri owner ultimately ended up with.

Since you asked -- albeit in a different context -- the room here was big (~600 / 60m2)
I had the set up in two different rooms. They actually worked better in the larger room which was 21' x 15.5'. I don't listen at obscene levels, but never clipped the amps. 20 watts of Apollo SET is probably like 80 watts of SS, and I'm sure having output transformers help in driving the speakers. I found the Guarneri did not like my smaller room, so I sold them and bought Avantgardes which actually worked a bit better in the smallish room. They are gone now too.
Chris, how large was your smaller room?
I suspect probably all speakers work better in a larger room than a smaller room. Mine is 10x11 with a 15' vault ceiling. I sit in the near field( no other choice). Sounds good, but I am sure a larger room would be much better.
Here in S.Calif, the room size is by far the most expensive component you are going to buy. Makes all other equipment choices in comparison seem like chicken feed in cost.
My room is 19'x11' with 8' ceiling. I think the Guarneri are the rare small speaker that sings in large spaces. They seem to thrive on having open space around them. They won't play deep bass, but they do mate well with REL subwoofers like the STRATA III.
Chris, your 19x11 room would seem to be more problematical in its ratio of size than your 21x15.5 room. Did you have the speakers on the long wall or firing down the long wall in the samll room?
I would suspect that maybe the smaller room would be an issue with most speakers due to its ratio.
Yes, the smaller room is a bit of a problem, although, I've successfully used Avantgardes in the same room. The bigger room in my other home sounded great regardless of what was in play. I think a clock radio would have sounded good in that room! I am using a single driver speaker now based on the Phy-Hp driver. It is utterly amazing and the room is not a bit of a problem Oh' I fired the Guarneri down the long wall. They were about 5' from the front wall and I was about 10' from them.

I recommend the David Berning ZH-270 OTL

This is one of the amplifiers SF use to voice their speakers. I have the Guarneri Berning combo and it really has a very nice synergy

I own Vienna Mahlers and McIntosh 2 x MC2102's drive them very well and sound great. It has been the only tube amp to correctly contril the bass, including cj prem8a's and VTL MB750's.

Try one and add another if need and when you can afford.

I have a pair of Guarneris and I love tubes and here is my experience in order of most favorable to least favorable. I own or have owned the following amps with the Guarneris.

Berning + CAT Ultimate 2 (Berning needs the CAT - the CAT is by far the most synergistic preamp I've had in my system)
CJ16LS2 + Art Audio Quartets with KR845 tubes

Joule Stargates (lovely triode, but not enough power for the G's)
Conrad Johnson MV60 el34 tubes (with Winged C or Sovtek) - not nearly as much bottom as any of the above (or as a Tom Evans Linear A on loan), but lovely midrange.

EAR534 (slow, muddy and poorly machined)
Conrad Johnson MV60 (ei tube or svetlana "s" tube)

The Guarneris are also very sensitive to the source. I'm currently using an Audio Note DAC and CDT2 and it sounds wonderful. I've had medium results with a Wadia 301 and poor results with an Arcam fmj23. For vinyl I've had good results with a KandK phono kit and poor results with an EAR834P.
Hi, check RCM Bonasus dual mono integrated from Poland. Now distributed in USA.
It's got very positive reviews in 6moons and Highfidelityonline.
After giving it a little more thought, I realized that I have wondered if a high quality - high power "transformer" based tube amp would kick up the bass response in the Guarneris. In my own experience, I've found many (what are the exceptions?) high-power tube amps lose transparency, emotion and harmonics and those are the sonic qualities that the Guarneris do the best. Nobody is going to buy them for "slam", but I've wondered how they would do with a very transparent high-powered transformer based tube amp. I've not tried such an amp with my Guarneris, although I would like to test drive such a combination some time. Best, Jeff
Following up on Gregm's recommendation, I recently got the KR Audio Kronzilla SXI integrated. It is extremely transparent and has AMAZING bass -- not just deep but it really takes control of the woofers, well beyond the more powerful solid state amps I've had in my system. You might be surprised what the Kronzilla amps can do for "slam".