The XSP-1 Differential Reference™ Preamp is the result of a two-year development effort aimed at creating a modern, reference-caliber, fully balanced analog stereo preamplifier with the flexibility and features demanded by the discriminating audiophile. The XSP-1 integrates a classically designed audiophile topology with an advanced, digital control system. Extreme care has gone into maintaining the purity of the analog path, while allowing the digitally controlled analog elements of the system to offer features, resolution, and accuracy unobtainable in a completely analog based design.

The XSP-1 offers the ultimate in sound quality and control for audiophiles who are searching for the finest possible stereo listening experience, but who also need a modern and flexible platform to fully satisfy their listening needs and system requirements. The XSP-1 delivers superb sound quality from a completely analog signal path that is fully differential from input to output. Like all Differential Reference™ components, the XSP-1 delivers an uncompromising and truly transcendent listening experience in Reference Playback mode by totally avoiding single ended to balanced conversions. In addition to its spectacular audio performance, the XSP-1 has a selection of advanced features that provide flexible yet precise control of your audio signal, and allow easy integration with modern systems that include one or more active subwoofers. We’ve even included a balanced home theater bypass mode for ease of use with high-end surround sound systems.

Input selection on the XSP-1 is via instrumentation grade relays with silver clad contacts; level control is via a set of high performance, high voltage, digitally controlled analog resistor ladder networks with 0.5dB per step resolution. This maintains signal integrity and provides near perfect channel matching and repeatability, which is critically important for image stability. Even the best audiophile analog potentiometers often have more than 2dB of channel tracking error at some points of their rotation, especially in the first 50% of travel, which is the most active area of use. This is a non-issue with the XSP-1; it provides virtually perfect channel tracking, from the lowest to highest level settings!

Unlike many other preamps these days, the XSP-1 includes a truly stunning and extremely quiet phono preamplifier with inputs for both moving magnet and moving coil cartridges (with user-selectable loading). This extreme attention to detail pays off with obvious sonic benefits.

The XSP-1 includes precision contour controls which allow you to tailor the high-frequency and low- frequency response of your system by a few critical dB to compensate for aberrations in source material, or make minor adjustments for room acoustics and speaker response. The contour controls operate by switching networks of precision discrete components, and can, of course, be completely bypassed.

Another unique feature of the XSP-1 is the built-in analog bass management which, with its independently variable high-pass and low-pass crossover frequencies, provides the flexibility necessary for perfect integration with high performance 2.2 or 2.1 systems. We’ve also included a high performance, high current, headphone amplifier with its own independent volume control and independent level memory. A large, clear, easy to read, VFD display shows system status messages and provides confirmation when you operate the controls. An external processor loop (tape monitor loop), trigger inputs and outputs, and, of course, a full-function milled aluminum remote control round out the feature list for the XSP-1.

In pursuit of the highest possible performance, the XSP-1 uses the finest quality passive components and hand selected semiconductors. Extensive shielding and careful design fully isolates all digital signals from the low noise analog signal path.

The list of features and design details for the XSP-1 can go on and on... but the real proof is in the listening experience, and in its incredible flexibility and ease of operation. We believe the XSP-1 offers the perfect synergy of high performance pure analog signal handling with digital control, accuracy, and convenience.

At last, we have achieved perfect balance.

Features

• Superb audiophile sound quality via an all-analog signal path.
• Vanishingly low noise and distortion.
• Fully balanced differential signal path.
• Two sets of balanced line inputs and one set of balanced main outputs.
• Four sets of unbalanced inputs and one set of unbalanced main outputs.
• Input switching via instrumentation grade relays.
• Level control via a high resolution (.25dB) digitally controlled analog resistor network.
• Hand selected semiconductors and top quality passive components for superb performance.
• Audiophile quality high current headphone amplifier with independent level control and memory.
• Independent control of main and headphone levels – and separate memory for each.
• High performance phono preamp that supports both moving magnet and moving coil cartridges.
• User configurable cartridge loading for moving coil cartridges.
• Full analog bass management with independently variable crossover points.
• Individually configurable high-pass and low-pass filters for subwoofers and mains.
• Support for both stereo subwoofers and summed mono sub.
• Digital flexibility and convenience including precise repeatability on all settings, a smart mute function, turn on level limit, and a full function remote control.
• True processor loop.
• Top quality parts and construction for years of reliable service.
• Gold plated solid brass machined RCA connectors.
• Gold plated XLR connectors.
• Highly regulated and shielded toroidal power supply.
• Informative (dimmable) front panel VFD display shows level, status, and input selections.
• Flexible trigger and control options.
• Universal AC line voltage.
• Fully transferrable five-year warranty.

Reference

Manuals
XSP-1 User Manual

Test Data
XSP-1 Full Test Report (PDF)

Photos

Specifications

• Inputs:
  Line level: 2 pairs balanced; 4 pairs unbalanced
  Home theater (line level, left, right, sub): 1 set balanced; 1 set unbalanced
  Processor loop (line level): 1 pair unbalanced
  Input impedance, line level: 50k ohms
  Phono (MM or MC): 1 pair unbalanced
• Outputs:
  Main: 1 pair balanced; 1 pair unbalanced
  (Main outputs may be configured as flat or high-pass; high-pass is adjustable from 50 Hz to 250 Hz)
  Subwoofer (left, right, summed): 1 set balanced; 1 set unbalanced
  (Subwoofer outputs may be configured as flat or low-pass; low-pass is adjustable from 50 Hz to 250 Hz)
  Processor loop (line level): 1 pair unbalanced
  Minimum recommended load impedance: 600 ohms
• Trigger:
  Trigger input and output: 1 each
  IR input and output: 1 each
• Gain structure:
  Nominal output level: 0 dBV (1 V)
  Nominal gain (with Volume set to “0”): 1
  Maximum gain: +12 dB
• High-Frequency and Low-Frequency Trims:
  HF trim (settings): -3 dB, -2 dB, -1 dB, Flat, +1 dB, +2 dB, +3 dB @ 12 kHz
  HF trim (inflection point): 4 kHz
  LF trim (settings): -3 dB, -2 dB, -1 dB, Flat, +1 dB, +2 dB, +3 dB @ 50 Hz
  LF trim (inflection point): 200 Hz
• Bass Management:
  Crossover slopes (high-pass and low-pass): 12 dB / octave
  Crossover frequency (high-pass and low-pass): User configurable, 50 Hz to 250 Hz
• Balanced Input to Balanced Output
  S/N (signal-to-noise ratio, A-weighted, ref +6 dBV): > 117 dB
  Frequency response: 20 Hz to 20 kHz +/- 0.02 dB
  THD + N (harmonic distortion plus noise, @ 1 kHz): < 0.0004%
  IMD (intermodulation distortion, SMPTE method, 60 Hz/7 kHz): < 0.001%
  Crosstalk (measured at +6 dBF, 10 kHz): < 100 dB
• Unbalanced Input to Unbalanced Output
  S/N (signal-to-noise ratio, A-weighted, ref +6 dBV): > 113 dB
  Frequency response: 20 Hz to 20 kHz +/- 0.015 dB
  THD + N (harmonic distortion plus noise, @ 1 kHz): < 0.0006%
  IMD (intermodulation distortion, SMPTE method, 60 Hz/7 kHz): < 0.001%
  Crosstalk (measured at +6 dBF, 10 kHz): < 102 dB
• Balanced Input to Unbalanced Output
  S/N (signal-to-noise ratio, A-weighted, ref +6 dBV): > 114 dB
  Frequency response: 20 Hz to 20 kHz +/- 0.015 dB
  THD + N (harmonic distortion plus noise, @ 1 kHz): < 0.0005%
  IMD (intermodulation distortion, SMPTE method, 60 Hz/7 kHz): < 0.0015%
  Crosstalk (measured at +6 dBF, 10 kHz): < 105 dB
• Unbalanced Input to Balanced Output
  S/N (signal-to-noise ratio, A-weighted, ref +6 dBV): > 115 dB
  Frequency response: 20 Hz to 20 kHz +/- 0.017 dB
  THD + N (harmonic distortion plus noise, @ 1 kHz): < 0.0003%
  IMD (intermodulation distortion, SMPTE method, 60 Hz/7 kHz): < 0.007%
  Crosstalk (measured at +6 dBF, 10 kHz): < 100 dB
• Phono (Moving Coil; phono in to balanced out)
  Gain (1 kHz, Volume at 0): approximately 60 dB
  Input impedance (user selectable): 47 ohms, 100 ohms, 470 ohms, 1k ohm
  S/N (signal-to-noise ratio, A-weighted, ref 1.0 mV in): > 79 dB
  Frequency response (referenced to standard RIAA curve): 20 Hz to 20 kHz +/- 0.35 dB
  THD (total harmonic distortion, ref 1.0 mV): < 0.008%
  IMD (intermodulation distortion, SMPTE method: < 0.15 %
  Crosstalk: < 65 dB
• Phono (Moving Magnet; phono in to balanced out)
  Gain (1 kHz, Volume at 0): approximately 40 dB
  Input impedance: 47k Ohms
  S/N (signal-to-noise ratio, A-weighted, ref 10.0 mV in, A-weighted): > 96 dB
  Frequency response (referenced to standard RIAA curve): 20 Hz to 20 kHz +/- 0.3 dB
  THD (total harmonic distortion, ref 10 mV): < 0.001%
  IMD (intermodulation distortion, SMPTE method: < 0.05%
  Crosstalk: < 80 dB
• Power Requirements:
  115 VAC or 230 VAC +/- 10% @ 50 / 60 Hz (automatically detected and switched).
  Power consumption (On): 32 watts
  Power consumption (Standby): <1 watt