Kenwood DPX-55MD

The Kenwood DPX-55MD is a double-DIN receiver with CD and MiniDisc transports and an FM/AM tuner. It is documented in a manual shared with two siblings, publication B64-3608-00, which the cover describes as covering the DPX-44, a dual-size CD and cassette receiver, the DPX-55MD, a dual-size CD and MD receiver, and the DPX-66MD, a dual-size CD and MD receiver with MP3, WMA and AAC support. Several entries are model-specific and are noted below.

The DPX-55MD does not decode MP3, WMA or AAC. The manual lists all three decoders against the DPX-66MD only. Its CD mechanism runs at 500 -> 200 rpm under constant linear velocity, where the DPX-66MD runs at 1000 -> 400 rpm at double speed. Both use a GaAlAs laser diode with an eight times oversampling digital filter and a 1-bit digital-to-analogue converter. The MiniDisc mechanism runs at 900 -> 400 rpm.

The CD section is quoted at 105 dB signal-to-noise at 1 kHz with 0.008 percent total harmonic distortion and 93 dB dynamic range, figures shared across all three models in the manual. The MiniDisc section returns 90 dB signal-to-noise, 90 dB dynamic range and 0.01 percent distortion.

Tuner performance also differs by model. The DPX-44 and DPX-55MD are quoted at 75 dB mono signal-to-noise with 30 dB stereo separation, where the DPX-66MD is quoted at 70 dB and 40 dB respectively.

Tone control is a three-band arrangement fixed at 100 Hz, 1 kHz and 10 kHz, each adjustable across plus or minus 8 dB. An auxiliary input accepts a maximum of 1200 mV at an input impedance of 100 kohm. The manual lists pre-out level and pre-out impedance against the DPX-66MD only, so the DPX-55MD has no specified pre-out. Mass is listed as 1.9 kg for the DPX-55MD and DPX-66MD, against 2.1 kg for the cassette-equipped DPX-44, making this the lightest double-DIN unit in the archive.

DPX-55MD SPECIFICATIONS
Media	CD and MiniDisc. MP3, WMA and AAC decoding are listed for the DPX-66MD only
FM tuner	76.0 -> 90.0 MHz in 100 kHz steps. Usable sensitivity 9.3 dBf (0.8 uV/75 ohm), S/N 50 dB sensitivity 15.2 dBf (1.6 uV/75 ohm), frequency response 30 Hz -> 15 kHz (plus or minus 3.0 dB), S/N 75 dB mono, selectivity 80 dB or more (plus or minus 400 kHz), stereo separation 30 dB (1 kHz)
AM tuner	522 -> 1629 kHz in 9 kHz steps, sensitivity 28 dBu
CD section	GaAlAs laser diode, 8x oversampling digital filter, 1-bit D/A converter, 500 -> 200 rpm constant linear velocity, wow and flutter below measurable limits, frequency response 10 Hz -> 20 kHz (plus or minus 1 dB), THD 0.008% (1 kHz), S/N 105 dB (1 kHz), dynamic range 93 dB
MD section	GaAlAs laser diode, 8x oversampling digital filter, 1-bit D/A converter, 900 -> 400 rpm, wow and flutter below measurable limits, frequency response 20 Hz -> 20 kHz (plus or minus 1 dB), THD 0.01% (1 kHz), S/N 90 dB (1 kHz), dynamic range 90 dB
Audio section	Maximum output 50W x 4, rated output 30W x 4 (4 ohm, 1 kHz, 10% THD or less), speaker impedance 4 to 8 ohm. Pre-out level and impedance are specified for the DPX-66MD only
Tone control	Bass 100 Hz, middle 1 kHz, treble 10 kHz, each plus or minus 8 dB
Auxiliary input	Frequency response 20 Hz -> 20 kHz (plus or minus 1 dB), maximum input 1200 mV, input impedance 100 kohm
Supplied parts	Power harness, truss screws M5 x 6 mm (six), flat screws M5 x 7 mm (six), sems screw M4 x 8 mm (one)
Electrical	14.4V (11 -> 16V), maximum current draw 10A
Form factor	Double-DIN, mounting dimensions 178 x 100 x 155 mm, mass 1.9 kg
Source	Kenwood owner's manual, publication B64-3608-00, covering DPX-44, DPX-55MD and DPX-66MD