Chord Etude is the first sample of a new circuit concept, invented by the head of Chord Electronics, John Franks. Based on theoretical work on circuits with proactive forward communication instead of reverse — and Bob Cordell, the author of a textbook on amplifier circuit design, was a consultant to Chord Electronics on these issues — and ultrafast key power supplies, John Franks moved Chord amplifiers forward. Following the Etude, new circuit solutions are embodied in the ultra-expensive flagship amplifiers of the Ultima series. So, Chord Etude has lived up to expectations.