Would a Pass Aleph 5 be able to drive Thiel 3.5 ?

Get a used Plinius SA-100 and end your search ($1800 to $2100 depending on the condition). The Aleph 5,Bryston 3B, or 4B-ST will not have enough current to drive the Thiel CS 3.5.

With all due respect to Audiomax while the Pinius SA-100 might be a good choice with the Thiel CS 3.5's I don't think that the two Bryston amps lack the current any more so than the Plinius might. All would be at the very least adequate. In fact the Bryston 3B is probably very very close to the Plinius in this regard. I'm not so sure about the Aleph 5, but my guess would be that it too can handle the load.

I currently own Theil 2.3's and a Pass Labs x-250(synergy):) I have listened to most of the Thiel line up past and present. Before upgrading to the x-250 I was using x-150 again synergy. When auditioning the 2.3's I compared the aleph 2's vs the x-150. I personally preferred the x-150's. The x-150's goto 15 watts in class A mode. The x-250's goto 40 watts in Class A mode. The smaller amps I compared them to were absolutely terrible; not enough power. Now my Thiel's sing:0 Also owned the x-2 preamp and it is 90% of the x-1 which I know own.

At low level volumes I think it would, but i would opt for a higher power amp. Classe are know to be good matches with the Thiels like the CA 201.

FWIW and years later. . .

I have an Aleph 5 which I purchased to drive some now "set-aside" speakers. I purchased for the third time a pair of Wilson Watt/Puppy 5 speakers (can't seem to find anything I like better long term).

While the W/P 5 are not quite as inefficient as the Thiel speakers in general, the WP's are still a demanding load (ignore their efficiency rating of 94db) as they make wide swings from about 1.5 ohms and up.

The Aleph 5 (stereo amp, 60 WPC) sounds very nice with these speakers for my listening habits, room and volume levels. However, I was recently auditioning a Gamut preamp in my system and found that when I turned the volume up well past my normal "loud" listening levels, the soundfield congested.

I suspect this was mostly caused by a combination of my room and the available power from the Aleph 5 amp (I think it just ran out of juice). Now this being said, this was a listening level well beyond what I would ever sit and listen to for any length of time.

The Aleph 5 is rated at 60 watts class A. I don't know what it really puts out. Nelson is pretty conservative with his ratings. I also don't recall what this amp does in 4 vs. 8 ohm conditions.