But the feature that Yamaha C-65 was known for is in the Phono section. The Yamaha C-series pre-amplifier has been considered by many Audiophile as one of the best preamp ever built by Yamaha. The C-65 employ what Yamaha calls “Zero Distortion Rule” circuits, apparently a combination of feed-back and feed-forward techniques that, in theory, can reduce distortion to zero.