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Graham Slee Solo Ultra-Linear Diamond Edition Headphone Amplifier



The Solo Ultra-Linear Diamond Edition hi-fi headphone amplifier gives you the sound you always wanted from a headphone amp. A headphone amplifier truly capable of making good headphones deliver a lifelike, dynamic and breathtaking performance with a real out of head three-dimensional stereo sound stage.

The latest Diamond Edition of the Solo Ultra Linear headphone amplifier is improved by having a lower noise floor for improved in-ear monitor listening and a new output stage for better performance with difficult and low impedance headphones, yet it has the clout to drive high impedance headphones too.

The Ultra-Linear voltage amplifier stage gives you the smoothness and warmth of a tube amp with all the precision, fine detail, and punchy sound of a solid state amp.


  • Headphone impedance range:  8 to 2,000 Ohms / 16 to 600 Ohms preferred
  • Power output:  (rms, both channels fully driven at 1% THD)
  • 32 Ohms:  140mW/channel; 600 Ohms: 30mW/channel
  • Input sensitivity (for specified power output into 32 Ohms):  511mV rms
  • Input impedance:  37k Ohms at max volume; 50k Ohms at min volume
  • Distortion:  (THD plus noise at 9 o’clock volume control setting (qtr power))
    10Hz-20kHz:  better than 0.04%; 10Hz-1kHz: better than 0.02%
  • Frequency response:   (±0,-3dB) 10Hz – 35kHz
  • Output noise:  (22Hz-22kHz, quasi-peak/un-weighted) -95dB
  • Channel balance:  better than 1dB
  • Crosstalk:  Left to Right -56dB; Input to Input -68dB
  • Input selector centre-off position:  non-shorting; -38dB at max volume with 2V rms input (ref: 1kHz and 10kHz)
  • Output Stage:  Bipolar class AB
  • Supply voltage:  24V DC unipolar
  • Size: W: 107 x H: 50 x D: 185 (mm)