Wilson Sasha W/P amplifier pairing

I acquired a pair of Wilson Sasha W/P speakers this year. They’re Series 1 Sasha’s. Now trying to find great mono blocks to power them. My other system has Harbeth Speakers and a Pass Labs amp, I love the combo and can listen for hours without fatigue. I’d really prefer something warm and non fatiguing for the Sasha’s. 

Amps I’ve tried so far:

Pass Labs X350 - too bright and forward, etched vocals, not a lot of sparkle but plenty of authority

Pass Labs INT-30A - much better all around than the X350 but still too bright and forward. Not nearly enough power for Sasha. End result is too cold and thin

Bob Latino ST-120 - this is a $1200 kit tube amp I built. 60WPC. This amp was surprisingly kind of magical with Sasha.  Never fatiguing and full bodied. Unfortunately it went up in smoke because I can’t solder.


Mono blocks I’m considering:

Audio Research Ref 160M

Lamm 1.2 Reference

Pass Labs XA100.8


Preamp is a PrimaLuna EVO 400. Rega RP3 with Exact cart. Denafrips Ares II DAC streaming Roon via MicroRendu. Any advice welcome. 


Surprised any of the Pass amps mentioned sounded bright and forward; my W/P6 sound great with my Pass X250. Maybe there’s something else going on in your system or room. Have you played with speaker placement and room treatment? Will note that before I added dedicated circuits to my system my Pass sounded just a little light, but on dedicated circuits it opened things up, fuller more relaxed, effortless with no fatigue whatsoever.

Try Pass Labs XA point 8 series of amplifier.  Never heard anyone describe Pass as bright. 

......correct me if I am wrong, but I do recall Dave Wilson showing as well as owning his speakers with Nagra equipment. It would seem to me based on the sonic characteristics of those two companies it just might be the match you are looking for.   

@gpgr4blu excellent summary. You've actually experience all of these amps so I really value and appreciate your opinion. I'm leaning Ref 160M since I know I won't have issues getting them serviced, plus they're gorgeous, auto bias, longer tube life, etc.

I've heard some people have had issues getting Lamm's serviced (they claim they can't get a hold of anyone). Vlad was a genius but since his passing this year I worry about customer support. Their website has been "under construction" for some time. That said, I've heard nothing but good things about the sound.

@adg101 maybe bright isn't the best descriptor. More forward and top heavy. I applied a 1.5dB rolloff above 14kHz via Roon and that helped. I've treated first reflections with GIK panels after consulting with them, that helped tremendously. But remember, I'm coming from Harbeth's, so going from zero fatigue to some fatigue seems like a stark difference.