SANSUI CD-α 917 XR (1994) | Reference CD Player

A Reference CD Player Built with Audiophile Precision. The SANSUI CD-α 917 XR is a high-end CD player designed to demonstrate how far digital audio engineering could go when precision, circuit isolation, and mechanical stability were treated as priorities. Featuring a then newly developed 18-bit MASH D/A conversion system, extensive vibration-control measures, and separate power supplies for digital and analog circuits, this impressive machine reflects SANSUI’s ambitious approach to reference-class CD reproduction.

SANSUI CD-α 917 XR – Main Specifications

D/A Converter: 18-bit resolution MASH converter, 2 units

Frequency Response: DC–20 kHz (±0.3 dB)

Total Harmonic Distortion: 0.0022% at 1 kHz

Signal-to-Noise Ratio: 110 dB or more (EIAJ)

Dynamic Range: 98 dB or more (EIAJ)

Wow and Flutter: Below the measurement limit

Output Voltage: 2 V (unbalanced and balanced)

Digital Outputs: Optical and coaxial, with an ON/OFF switch

Digital Attenuator: Adjustable from 0 dB to −26 dB, with fade-in and fade-out

Dimensions (W × H × D): 466 × 126 × 391 mm

Weight: 14.1 kg

Accessories: Wireless remote control

SANSUI focused on improving digital signal-reading accuracy while reducing common-mode noise and distortion. The design was intended to improve the signal-to-noise ratio, particularly addressing distortion in the high-frequency range. The conversion method also aimed to eliminate zero-crossing and nonlinear distortion in principle, helping preserve low-level musical information and subtle details. Balanced signal processing: The digital signal is processed through balanced operations, eliminating the need for an inverting amplifier in the described signal path. This helps avoid associated phase shifts and reduces the susceptibility of balanced output to noise. Completely Separated Digital and Analog Power Supplies. Independent power delivery: Rather than relying on a single shared supply, SANSUI equipped the player with dedicated transformers for the digital and analog sections. The design incorporates 15 independent power-supply systems serving individual sections, including the microcomputer, DAC, disc drive, display, and analog circuitry. This separation was intended to prevent electrical interference between circuits and reduce the risk of digital activity affecting sensitive analog audio signals. Carefully selected capacitors: The power supply also uses electrolytic capacitors featuring low-magnification aluminum foil, reflecting the manufacturer's attention to component selection and circuit performance. Copper Shielding and Mechanical Stability. A central copper dome: The CD-α 917 XR retains a center-mounted mechanical layout, enhanced by a newly developed pure-copper dome. This structure shields the central drive mechanism from surrounding circuitry. The arrangement also helps optimize weight distribution and increase chassis rigidity, while reducing motor-induced vibration and resonance. The copper shielding serves additional purposes, including limiting interference from the digital pickup section and shielding other circuitry from unwanted radiation. A resonance-controlled chassis: SANSUI paid considerable attention to the player's enclosure. The bonnet is coated with a special paint mixed with copper powder to help suppress resonance within the cabinet. Elliptical insulators help isolate the player from external vibration, while Teflon sheets and tapes are used at selected contact points. Copper plating on the back panel and center channel provides further measures against unwanted casing vibration. These details illustrate an engineering philosophy in which mechanical construction was considered an important part of achieving consistent CD playback. Premium Components Throughout the Circuitry. Audiophile-grade component selection: The CD-α 917 XR uses a range of carefully selected components, including Silmic Super Gold capacitors, GSG film capacitors with gold-plated leads, RMG resistors, SA film capacitors, and specialized styrol capacitors. Gold-plated leads and anti-vibration treatments reinforce the emphasis on component quality and mechanical stability. The CD mechanism also receives special attention, with copper plating on the play chassis and a Teflon coating among its vibration-control measures. Balanced Servo and Low-Pass Filter Design. Balanced circuitry: The player incorporates a balanced servo system and a balanced low-pass filter, complementing its balanced analog outputs. For enthusiasts using compatible equipment, balanced connections offer an alternative to conventional unbalanced RCA connections and may be particularly useful in systems where noise rejection is important. Digital Attenuation and Direct Power-Amplifier Connection. Volume control without a conventional preamplifier: One particularly useful feature is the digital attenuator, which allows the output level to be reduced from 0 dB to −26 dB. This makes it possible to connect the player directly to a compatible power amplifier, potentially simplifying the system by eliminating a separate preamplifier. The CD-α 917 XR also offers fade-in and fade-out functions, allowing the music to move smoothly from the selected listening level to silence. Beyond its core playback functions, the player includes a generous selection of features: Peak Search: Locates a disc's peak level, displays its level, and plays the selected peak passage for five seconds. Display ON/OFF: Allows the front-panel display to be switched off. Auto Space and Auto Pause: Provides additional control over pauses and gaps between tracks. Following Memory: Supports continued programming or playback memory functionality. Music Scan: Makes it easier to preview tracks. Five-Way Repeat: Offers several repeat-playback options. Wireless Remote Control: Enables convenient operation from the listening position.

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