Speakers that work with Atma-sphere M60 amps.

Avguygeorge, certainly various horns will fall into that category of OTL M-60 compatible. Note Duke's recommendation of the Avantgarde. Also, Cain & Cain, Zingali and others. It will usually come down to the design of the crossover.
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THanks for all the info. I have heard that coincident and Merlins are good matches. ANyone have experience with Silverline speakers? Their impedance also matches.

Von Schweikerts work well also.

Add Lowthers to the list. Members of the Chicago Horn Club heard a pair of Lowther PM2As driven by a pair of Atma-Sphere MA-1s a few weeks ago to great effect, perhaps overkill since M-60s and probably an S-30 would have been adequate. Jon Ver Halen of Lowther America was there as well. It can't speak for him but one could ask his opinion.

The ZERO autoformers enable other speakers to be used successfully with the amps.

Brian

As a corollary to Gregadd's post, I found that my Raven R3.1 ribbon drivers truly revealed their dynamics and speed with M60s. Their 3ohm nominal impedance doesn't labor the the M60s given their 99 dB efficiency. I have the luxury of actively biamping, keeping the M60s from having to drive paired 12 inch midbasses at 4 ohms. Matched to the right loudspeakers, otls are quite remarkable.