The SDR-4000 Reference CD Processor

Back to the future

The SDR-4000 Reference CD Processor is Spectral’s ultimate compact disc player, completing the Spectral Digital Reference system begun with the SDR-2000 Digital Processor. The development program for the SDR components was initiated over 15 years ago with the introduction of the Spectral SDR-1000 Reference Disc System, the industry’s first truly high-end compact disc playback system. The innovative SDR-1000 was years ahead of its time, pioneering fundamental processing breakthroughs such as balanced decoding and conjugate correction filters. More recently, the ambitious SDR-2000 Professional Processor has stunned the audio industry with its technical advances and resolving power. Sharing its uncompromising circuit architecture with the historic HDCD recording system by Pacific Microsonics, the Spectral SDR-2000 is widely considered to be the finest digital processor available as well as the acknowledged reference for High Definition Compatible Digital recordings.

The arrival of the SDR-4000 Reference CD Processor culminates the SDR program at Spectral and achieves the final integration of our high resolution digital technology. Supporting the challenge are new generation component technologies and state-of-the-art test systems to push forward the envelope of digital audio performance. Like other Spectral SDR components, no detail or expense has been spared in the SDR-4000 to achieve the status of a true reference.

SDR-4000 Digital Systems Specifications

Sample Rate: 44.1KHz
D/A Conversion: Four custom 24 bit DACs in double balanced configuration
Digital Filter: 8x oversampling, 56 bit math 64 bit accumulator HDCD
Analog Filter: Linear phase to 28KHz
Frequency Response: DC to 22KHz +/- .3 dB (limited by encoding)
DAC Step Resolution: Better than -120dB
Digital Noise Output: 100 uV peak to peak or less
Transient Overshoot: 8% or less
Intrinsic Jitter: 1 picosecond RMS 3-4 picoseconds peak attenuation corner frequency @ 100Hz

SDR-4000 Analog Systems Specifications
Outputs: RCA single-ended
Output Impedance: 100 Ohms
Frequency Response: DC to 1.2 Mhz -3 dB
Harmonic Distortion: Less than .001
Intermodulation(SMPTE): Less than .001
Nominal Output: .75 Volt rms
Output Voltage Swing: 2.5 Volts rms maximum
Signal to Noise Ratio: Greater than 115 dB
Channel Separation: Better than 115 dB
Slew Rate: 250 V/us

SDR-4000 Power Requirements

Voltage: Factory set 120, 220, 240 VAC @ 47.5 Hz to 440 Hz
Continuous Dissipation: 65 Watts

SDR-4000 CD Transport Specifications

Front Panel: Load Selector
Play Selector
Stop Selector
Pause Selector
Operate/Standby Selector
Time Display Function Selector
Display Brightness Selector
Scan Backward Selector
Scan Forward Selector
Previous Track Selector
Next Track Selector

Rear Panel: Spectralink Digital Interface (optional)
Main Power Switch
AC Line Fuse
IEC AC Power Connector

Compact Disc Drive: Front load type with VRDS clamping system, diecast alloy contruction
Disc Loader: Precision type with polished linear bearings
Pickup: Objective lens drive type with 3-beam laser pickup linear drive servo
Wow & Flutter: Below measureable limit (accuracy of crystal)

SDR-4000 Mechanical Specifications

Dimensions: 48cm (19") W, 10.5cm (4.25")H, 40cm (16")D
Weight: 14.1 KG (46 lbs.) net

Matej Isak

Mono and Stereo ultra high end audio magazine
All rights reserved, October 2011