Best Tube Amp For Sonus Faber? Or Pass XA-100.5? $6-7,500 Budget, Purchasing Used.


As the title says, I have a pair of Sonus Faber Olympica III's that I am more than pleased with, for which I am trying to determine the best available amplifier, preferably tube. Of course, there are always budget limitations and my budget for this amp would be $6-7,500, and I would be buying used to maximize purchasing power.

Based on a lot of research, and quite a few auditions at brick and mortar stores, various home systems, Axpona, etc. I'm honestly not sure if there are any truly exceptional tube amplifiers available within that budget that meet my needs. These speakers need 100wpc tubed, or 200 wpc solid state, into 4 ohms to really open up and perform. 

If, in the end, there are no really great tubed options, I've always heard that the Pass Labs XA-100.5's were probably the optimal choice in solid state for former tube lovers. I would also appreciate any thoughts on that option from owners. 
nightfall
Hi Nightfall-I would pair Audio Research with Sonus Faber since both are owned by the Fine Sounds group AND ARC is now using Sonus Faber to voice their equipment. 
nkonor,

You’re results with that combination sound ideal, but isn’t the Manley Steelhead just a phono stage?
jperry,

After reading the earlier suggestion, and some additional reviews, I did list the Aesthetix Atlas for serious consideration, going forward. I also checked out the one being offered right now on Audiogon. If it were only silver (the same as all the rest of my components) I might have already snapped it up for that price!
Nightfall,

If you are interested check with Aesthetix on the cost of swapping out the faceplate. I have a black one too but wanted silver. I think it was under $400
Wharfy, you said "I would pair Audio Research with Sonus Faber since both are owned by the Fine Sounds group AND ARC is now using Sonus Faber to voice their equipment."

Interesting timing. I have a very good friend, and audiophile, who spent much of last December auditioning speakers with me three or four times a week before I settled on the Sonus Faber Olympica III's. I just got a call from him on this very topic. He is currently in Chicago on business and ended up with yesterday afternoon off due to a client cancelling a meeting. He took the time to explore a few audio stores. One of them was a Sonus Faber dealer and had the Olympica III's on display powered by the Audio Research REF-75 power amplifier and an Audio Research preamp (he does not recall the model). He says it powered the Olympica III's really well, produced excellent sound and he apparently listened for an extended period.

I have always loved the look of that amp, and had respect for AR. It would seem that might be one of the only tube amps that seem able to handle the load of the Olympica III's. I know it is a fully balanced design, so it would require me selling my existing preamp and likely buying an AR model (maybe I could find a REF5 at a good price), but that would certainly be an option.