1987 - Yamaha CDX-1100U Natural Sound Compact Disc Player 18bit

Super heavy. No remote. Super Rare. The Yamaha CDX-1100 is the first player to achieve the performance of 18-bit digital decoding from a 16-bit digital-to-analog (d/a) converter. In addition, it provides almost every operating convenience currently available in a CD player. The CDX-1100 uses 18-bit quadruple-oversampling digital filters for each channel. The 176.4-kHz sampling rate of the filters greatly reduces noise in and just above the audio range compared with nonoversampling, 44.1-kHz filters.

These characteristics help preserve a flat response and produce less phase shift and ripple within the audio range. Compared with 44.1-kHz sampling, quadruple oversampling gives a fourfold improvement in time-axis resolution, although this is normally beneficial only at the higher program levels. Yamaha's 18-bit filters extend this improvement to the low-level portions of the program, where they also provide a fourfold improvement in amplitude resolution and correspondingly lower distortion. The peak levels on a digital disc rarely reach the two highest, or most significant, bits of a 16-bit system, so the full capability even of 16-bit d/a conversion is needed relatively infrequently. Many CD players, in fact, use 14-bit decoders without a significant loss of quality.