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

pass aleph 5 is rated 60W/ch pure class A. The way it drives the speakers even with low efficiency it would seem to me that it works at least twice the rated power. I'm not realy sure if it does switch to B after it riches 60W/ch but it no worse driver than 3B-st. The musicality and mids are very close to tube performance so I guess you should only gain in performance but you might notice that your room will be much wormer since this amp is getting real hot.

Good luck!

Of course your room and desired volume level are paramount in this regard. Your pre-amp out put should be considered too. Thiel recommended 50-250 watts (as rated into 8 Ohms). As they are a steady 4 Ohm load I prefer to think in terms of 100-500 Watts into 4 Ohms. The 3.5's use and equalizer to bolster bass response. This can put an added burden or your amplifier. The answer to your question is yes but more power would be better. I would recommend at least 200 Watts into 4 Ohms. By the way, I think Pass would sound very nice with these Thiels, but some of the early Pass amps were not suited to this steady 4 Ohm load. Rumour has it that the 3.5's were designed around the then top of the line Threshold gear (earlier Nelson Pass designs). You may be on the right track but proceed with caution.

As a current owner of Thiel 3.5s; I would agree with Unsound's remarks. The 3.5s DO sound better when they have a higher powered amp to drive them. A Bryston 4BST would be an excellent choice. I'm a McIntosh fan - so I'm driving mine with an MC150 amp right now - though I'm considering a
possible move up to a Mac 200 watt amp later this year.

I would think the 5 would be up to the task as I had a 4B ST & replaced it with a 5. I had more efficient speakers than you do but on a comparative level the 5 did everything the 4B ST did in terms of adequate volume but much more musical. I sold the 4B ST as it was too analytical for me & subsequently sold the 5 as it wasn't quite what I was looking for. I now have an Ayre V-3 which I'm really happy with but will probably move up to a V-1.

I would say if classical, jazz & female vocals make up the bulk of your listening, then the 5 will do it for you. If you prefer rock, electronica, metal & so on it may not float your boat. That was my experience with the two amps.

Of course, the best thing would be to try an in home audition but even if you purchased & it didn't work out, you'd be able to resell easily. Good luck!

The Pass Aleph series are all single ended. That topology cannot operate in anything other than class A (and still be listenable!).