Accuphase DP-11 (1989)
High-end CD player from Accuphase Laboratory, released in December 1989 with 18-bit D/A conversion and digital volume control.
Overview
The Accuphase DP-11 is a CD player developed using technology from Accuphase’s top-of-the-line separate-type CD players. Manufactured by Accuphase Laboratory, Inc., it was released in December 1989 and features a non-contact optical reading system with a GaAlAs semiconductor laser. The player includes both balanced (XLR) and unbalanced (RCA) analog outputs, along with optical and coaxial digital outputs compliant with the EIAJ standard. It comes with the Remote Commander RC-4, operating via infrared pulses and powered by two SUM-3 (R6) batteries.
Specifications
| Product type | CD Player |
| Production years | Released in December 1989 |
| Quantization | 16 bits |
| Sampling frequency | 44.1 kHz |
| Error correction method | CIRC |
| Number of channels | 2 channels |
| Rotation speed | 500 ~ 200 rpm (CLV) |
| Performance speed | constant 1.2 ~ 1.4m/s |
| Reading system | Non-contact optical reading (using semiconductor laser) |
| Laser | GaAlAs (double hetero diode) |
| Frequency characteristic | 4.0 Hz to 20000 Hz ± 0.3 dB |
| D/A Converter | Ladder Resistance Type 18 Bit |
| Digital filter | 8 x Oversampling |
| Digital de-emphasis function | Deviation ± 0.001 dB |
| Total harmonic distortion factor + noise | 0.002% (between 20 Hz and 20000 Hz) |
| S/N | 114dB |
| Dynamic range | 98dB |
| Channel separation | 106dB |
| Rated output / output impedance | Balanced : 2.5V/50 Ω (25 Ω / 25 Ω), balanced XLR type; Unbalanced : 2.5V/50 ohm, RCA phono jack |
| Digital Level Control | 0 to -24dB in 1 dB steps |
| Digital output format level | Formatting : Digital Audio Interface; Optical : Optical output : -21 to -15dBm (EIAJ), emission wavelength : 660 nm; Coaxial : 0.5Vp-p/75 Ω |
| Semiconductor used | Transistor : 15 IC : 46 Diode : 26 Units |
| Power | AC100V/117V/220V/240V, 50Hz/60Hz |
| Power consumption | 20W |
| External dimensions | Width 445x Height 95 (Including Legs) x Depth 325 mm |
| Weight | 13.7kg |
| Attachment | Remote Commander RC-4 |
| Remote control system | Infrared pulse system |
| Remote power | DC 3V Dry battery SUM-3 (IEC Designation, R6), 2 units |
| Remote maximum external dimensions | 64 mm wide x 176 mm high x 18 mm deep |
| Remote weight | 180g (including dry batteries) |
Design
The DP-11 uses carefully selected 18-bit D/A converters and an 8x oversampling digital filter that suppresses frequencies between 24.1 kHz and 328.7 kHz by -110dB, with passband ripple within ±0.00005 dB. The audio low-pass filter is a discrete GIC third-order Butterworth active filter with 18dB/oct characteristics. Digital and analog circuits are electrically isolated using four ultra-high-speed 40Mbit/sec optocouplers per channel. The player features separate power transformers for digital and analog circuits, with independent left/right windings on the analog transformer. Internal circuits are fully shielded with thick metal plates. The laser pickup uses a linear motor mechanism controlled by an 8-bit microprocessor, enabling music selection in about one second, and is mounted on a floating aluminum die-cast frame. A noise shaper reduces quantization noise by feeding rounding errors back into the data stream. The analog output stage uses a DC servo directly connected buffer amplifier with no gain, and volume is controlled digitally in 1 dB steps from 0 to -24dB. The DP-11 also includes a power-on play function that activates playback automatically when powered, in conjunction with a timer.
Context
Accuphase Laboratory, Inc. was founded in late 1972 by former Kenwood engineer Jiro Kasuga, with a philosophy to "enrich life through technology." The brand name combines "Accu" from "accurate" with "Phase." The DP-11 reflects the company's expansion into digital sources, applying high-end engineering principles from its flagship models. Accuphase products are known globally for sound quality, build, and reliability, with many early units still operational today.
Market
The current market price for the Accuphase DP-11 is €900. An original Accuphase DP-11 information folder in English is available as a resource, and user reviews in English can be found online.
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