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
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Several posts re the Oly's 3 by SF

just some personal observations as an owner of these extraordinary loudspeakers: first of all, IMHO, they are not compressed, veiled, slow, dull, small, or 'blah' sounding speakers, they are everything but that.  That said, are they are as 'good' as the upper level SF offerings?  I have no idea ! Not going there, as I have no present desire to do so. When I first bought and listened to mine I was not initially floored.  My reference was a pair of bigger speakers with larger woofers, much heavier and more efficient but great speakers nonetheless.   The Oly 3's required some adjustment on my part.  Great WAF and as speakers weighing only about 100 lbs each I could handle them fairly easily vs wresting 200 lb speaks. The fit and finish is world class.  The changes I made upstream made all the difference in the world which allowed the 3's to really shine.  I added  a 2nd external power supply to my First Sound dual mono tubed pre amp. Added an external power  supply to my tubed phono pre amp.  Bought a Pass X250.8 ss stereo amp. You can't make chicken soup out of chicken sh!t. 4 ohm speakers? Matters not, you need juice!  You need quality upstream or any speaker just doesn't show what it can do. Listen to these speakers playing Ry Cooder's I Flathead, JJ Cale's Troubador (vinyl please), or Amy Helm's Didn't it Rain, at a reasonable volume and tell me these speakers are less than excellent and we will discuss them further. Or not.  Again, my experience, my room, my ears.  Just be sure to compare apples with apples before making blanket statements.  These are room filling, nut jarring, smooth, detailed, soundstage champs that excell at making music. Plus they don't cost (used) a king's ransom, don't punish your ears, and won't break your back handling them.   Phenomenal product. 
markmendenhall said "Phenomenal product"...

I couldn’t agree more!!! Feed them Kobe steak..not generic hot dogs..and you will then understand what all the fuss is about. Great speakers...period!!!
A tube creates distortion
Most transistors create a lot more. In fact triodes are extremely linear!

What makes distortion in any amp is not so much the devices used, but **how** they are used: the topology. Some tube amps are inherently extremely low distortion (lower than many transistor amps) and others are obviously not.

However, ’distortion’ by itself is not telling enough. Some types of distortion such as lower ordered harmonics are not objectionable to the ear even in fairly large amounts. Other types such as higher ordered harmonics and intermodulations are objection in vanishingly small amounts, some of which can be difficult to measure.

So far the industry does not place a weighting on distortion, viewing it all on a level playing field while the ear does not. But if they did, tubes would be considered overall extremely low distortion.
Spearit Audio is closing it's doors. They have a CJ ET 250 $8500 for $2999. Also if you want to go over budget they have a CJ Art audio Amp for $9999. Regular price $20,000.