Sony CDP-55

The Sony CDP-55 is an unusual beast: a two-box CD player with the transport and power supply in one chassis and the DACs and analog output stage in a separate chassis. It sold for $380 at a time when Sony's own ES line dominated the company's high-end image, yet this non-ES model was quietly built to a standard that has kept it in service for over three decades.

The standout feature is the conversion stage. Instead of Sony's house-built filter and DAC chips, the CDP-55 uses a Burr-Brown PCM58P in a dual-mono configuration — one per channel — fed by a DF1700P 8x oversampling filter. That's a deliberate departure from typical Sony practice of the era, and it gives the player a character its 1-bit siblings lack. A separate transformer feeds the transport and the DAC sections. There's a coaxial SPDIF output but no TOSLINK optical. The laser is a KSS-150A, riding on a Sony "full-floating" mechanism built around a Philips CDM-2 transport.

The CDP-55 came in at least two flavors: this oversampled Burr-Brown design and a later single-bit version, visually indistinguishable. A period advertisement in Audio (December 1986, p.43) promoted Sony digital equipment as capturing the experience of live music.

As with any vintage unit, the capacitors, the KSS-150A laser, and belts are the expected failure points.

Known specs:

- Price: $380

- DAC: Burr-Brown PCM58P, dual mono (one per channel)

- Filter: DF1700P, 8x oversampling

- Laser: KSS-150A; mechanism: Sony full-floating / Philips CDM-2

- Frequency response: 2 Hz–20 kHz ±0.5 dB

- S/N ratio: 115 dB; dynamic range: 115 dB

- THD: 0.0012%; channel separation: 110 dB

- Output: fixed RCA; coaxial SPDIF (no optical)

- Power consumption: 23W

- Dimensions: 430 × 90 × 310 mm; 4.6 kg