It depends on you room size. Just yesterday I went over to my buddy's place. My buddy had my LSA wasp class D ...125 wpm into 8 ohm amp at his place for 2 weeks. . He has the acoustat, not sure of model, about 7 feet tall and maybe 12 to 15 inches wide. His room is approximately 17 ft by 21 feet. He had been using NAT mono blocks, but couldn't get them to drive the acoustats. His jaw dropped when he heard this amp with his speakers. he subsequently, spent many hours in the music room. I can only guess that the current the amp produced is what drove them satisfactorily.

Back in the day there was an Acoustat dealer that I visited on several occasions. He drove the speakers with the VAC Renaissance 70/70 amplifier (Push-pull 300b, 65-70 per channel) with truly excellent results. Granted these amplifiers were built with very stout power supplies ​​​​​​.

I did not realize that their sensitivity was that low (81db) so I understand The recommendation for higher power solid-state amplifier. But, I can attest to the fact that they were marvelous sounding driven by the VAC amplifiers. The speaker probably has a friendly impedance load.

Charles

Sorry, forgot to mention, he also had a pair of subwoofers along side of his acoustats. I must say I was very impressed with the sound I heard, considering the age of the speakers. He also had mentioned that he thought they were 82 or 86db efficient .

Sorry, forgot to mention, he also had a pair of subwoofers along side of his acoustats. I must say I was very impressed with the sound I heard, considering the age of the speakers. He also had mentioned that he thought they were 82 or 86db efficient .

@jasonbourne52 +1