The Audio Research SDP1 is a multichannel music processor designed to expand a traditional stereo setup into a five-channel matrix, enhancing the spatial experience of two-channel recordings. Introduced in the mid to late 1990s, the SDP1 was Audio Research's foray into pseudo-surround sound, aiming to synthesize rear and center surround channels from stereo sources.
Production
1995
Condition
9/10
Serial No.
25180001
Orig. MSRP
$2,995
Restoration
- Replaced missing knob
- Cleaned control contacts
- Inspected and verified main board
- Verified all inputs and outputs
- Unit comes with owners manual
Factory Specs
L-R ambience extractor
Inputs: one pair, balanced or unbalanced
Input impedance: 1.5Megohms unbalanced, 3M ohms balanced
Gain: 12dB maximum (6dB balanced into unbalanced out, 10dB unbalanced into balanced out)
Frequency response: 2Hz-400kHz +0, -3dB
Distortion: <0.01% at 2V out. Noise: <30µV RMS, IHF-weighted, center channel
Maximum output: 18V balanced
Controls: two surround level, one center level, surround delay (25, 28, 32, 38, and 45 milliseconds), Mute, Power. Outputs: one pair surround, one pair pass-through L and R, one center, all balanced and unbalanced
Power consumption: 40W.
Dimensions: 19" W by 11¾" D by 3½" H
Weight: 11.5 lbs.
The History of Audio Research
Audio Research Corporation, affectionately known to fans as ARC, was founded by William Z. Johnson, who began designing custom audio electronics in the early 1950’s and who also operated a specialty audio retail store until the mid-1960’s. Johnson’s efforts almost single-handedly revived vacuum-tube designs at a time...
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Liner Notes
The SDP1 Multichannel Music Processor is intended to be used with any conventional stereo preamplifier to achieve a 5-channel matrix from two (stereo) channels of information. It does not use Dolby® noise reduction or steering logic. The SDP1 has rotary controls for adjustment of level (volume) of center, rear-right and rear-left channels; a fourth rotary control allows choice of time delay for the rear channels from a menu of 5 options ranging from 22 ms to 45 ms. Rear and center channels are operated at full frequency bandwidth, with a minimum of signal manipulation or processing; this helps insure tonal accuracy, transparency and best dynamics. Delay is achieved through advanced digital tech- nology, while gain circuitry (12 dB overall) is fully analog. Front L and R channels remain completely unprocessed at all times for maximum fidelity.
The SDP1 features both single-ended and balanced inputs and outputs (three outputs for connections to center and rear channel amplifiers). It is connected to a set of main outputs from the existing stereo preamplifier. Once the center and rear channel levels are set, the main preamp volume control becomes the master control.
While designed to meet strict sonic criteria for music reproduction, the SDP1 processor also performs amazing feats of resolution in video or theater applications. Coherence of the entire sonic envelope and ease of operation are the hallmarks of the SDP1.
Designed for use with the SDP1 processor is the SDA1 Four Channel Power Amplifier.
Stock No.
8958927077597
