Pass....Accuphase....or......

I’ve had significant seat time w great musical happiness with subject speakers and a variety of Ayre amplifiers…. still a great company after CH passing. Ariel is agreat engineer…with ears

PS …if i was a younger man and wanted to spend more than my normal 3 months in Canada… i would seek to restart Verity…. 

If @grislybutter is right, the OP should be checking out some good SET amps. Why mess around with these Class A SS amps, go straight to a good 2A3.

I drove mine with a few different amps, the Luxman M800 was probably the most solid with them. That was 60/120. The 590 was okay the 550AXII for low levels. You need to hear a few amps and align with your preferences and circumstances. I’ve had a few Ayre amps, dealer friend demos but liked the Luxman better.

One great sounding combination I heard them with was the Audio Research Ref 110 with Ref 3 preamp.

As for lighter load, I would guess that the impedance curve on these isn’t horrible, but agree with Ozzy you wouldn’t call them high efficiency. I owned the Otello’s, much easier to drive with 93db eff I think. I’d say they Otello's are on the lower side of higher efficiency at best. Drove those great with 30 wpc tubes.

@atmasphere Relaxed, yes (laid back, no) effortless presentation is probably what I call "air" in the music, as in a big concert hall. "even at higher volume levels"...then you need dynamics, otherwise it becomes a  flat/compressed presentation. I don't now about the tricks with distortion, you have to talk to Nelson about that ;). The best amps I ever heard were BIG Audio Research monoblocks and BIG pass Labs, talk about effortless! But I can´t afford such a system....That's why I listen to live music whenever I can.....after all: it's the real thing!