Solid State Amps for Quad ESL 57?

Bass is hard to get with transistors and Quads. The problem is that the speaker does not run according to the rules that a lot of box speakers use- it seems to work best with amplifiers that can make constant power regardless of load- which is usually a tube amp.

Many transistor amps will double power as you cut the load impedance in half. The Quad has high impedances in the bass and low impedances in the treble/HF region. Most transistor amps will play the speaker with weak bass and too much highs.

Given Atmasphere's explanation, maybe this is why some find that the old Quad 303 works reasonably well with Quads. It is solid state, but my understanding is that its power output actually drops as impedance drops. There are a few firms that do updates, like Net Audio or the new one that advertises on EBAY.

Quad 909