Mapman..just a motivated consumer. I have always been intriqued by the 90% efficiency of Class D amps compared to 50% efficiency of a/ab amps that send a lot of wasted energy to the heat sinks. In 1958 there was testing done with pulse switching devices with poor results with current stability problems causing the test amps to blow up. When John Ulrick of Spectron owned Infinity speakers back in the late sixties with Arnie Nudell, he installed his first Class D amp into a Infinity sub-woofer in 1968. The rest is history. Regarding Wyred4Sound, EJ informed me back in 2011 that he was working on a new four piece Class D amp that would be part of the new Wyred4Sound Reference Line but unfortunately that project has been cancelled.