I owned original Quads with the Quad II power amp. I switched to Threshold SA/2 monoblocks and they sounded a lot better. I tried ARC tube powever amps and while they sounded great with the Quads, I preferred the Thresholds. Caveat though, this is 10 year old info. But, I just sold my SA/2's a few months ago and they still sounded very good compared to the current crop of amps.
Best amplifier for original QUAD ESLs?
Many folks say the original QUAD II is the best amp. Others say the solid state wonders like the Pass Aleph 3. What is the best solution within the 33 peak volt constraint and the capacitive load? What amps can provide an extended top end without sounding strident in the midrange? Are any also suitable for the 63s and 9xx?