Richard Clark $10,000 Amplifier Challenge - Why Couldn't Anyone Pass this Test??

It has long been considered common wisdom that OTL amps are great with the original QUAD ESL. When I had just gotten my first pair of the speaker, I asked Roger Modjeski at an instore seminar for his view on amps well-suited for the QUAD. He had worked on many Futterman amps, and in the 1980's designed his own OTL, which he ended up selling to Counterpoint. He also worked on the direct-drive tube amp used in the Beveridge ESL, fixing some problems he found in the amp when he went to work for Bev. Roger said that though the OTL/QUAD combination was indeed considered by many to be a good synergistic match, he considered it to be the opposite---an OTL being the absolute worst amp design for use with that speaker. The reasons included the matter of the impedance swings in the speaker, of course. Roger has designed and currently offers an ESL with a direct-drive (no speaker transformer) tube amp, which I am dying to hear. 

Wow, what a great post from Ralph/atmasphere. As always!

Because all properly designed and built amplifiers not in clipping sound exactly the same, of course ;-). But seriously, shadorne's assertation that "well built amplifiers....." can be proven to be untrue by hooking up a low-powered class-A amplifier (a Pass Labs or First Watt would be nice) to, for instance, the original QUAD ESL, a very transparent loudspeaker. My Bedini 25/25 driving my QUADs sounds dissimilar from my two high-powered class-A/B amps doing the same. As Nelson Pass suggests, it is an amp's first couple of watts that matter the most!