The CD3 was a two box unit, with a separate power supply. Ayon has since done away with the two box pieces, and the CD2 should be a significant upgrade over the CD3. Schroeder's review claims the CD2 to be "at least a 15% upgrade over the CD3." It uses the same four 6H30 tubes in the CD3. The kicker was that Ayon reduced the price of the CD2 from that of the CD3.