Unison Research’s unrivalled ability with Single-Ended valve designs is well known around the world. The SH is the company’s first headphone amplifier to benefit from such extensive knowledge and ability.
The SH uses a Single-Ended Class A design with only two stages and a passive volume control. The classic refinement of the valves combines with modern technology found in the internal USB DAC to produce something truly stunning.

USB DAC SPECIFICATION
Asynchronous USB interface compliant to USB 2.0 Audio Class
Accepts PCM up to 384kHz and DSD up to 128x
Resolution up to 32 bits
Last generation ESS Sabre DAC with jitter eliminator circuit
Galvanic isolation between USB interface and conversion circuit
Low phase noise clocks which reside in the “clean” supply domain to preserve low jitter performance
110dB SNR (@ 1kHz, “A” weighted, 192kHZ) 0.008% THD+N (@ 1kHz, -3dBFS)

• Maximum output voltage (THD 1%) : output "High sensibility" 0.5 V/150 ohm, 0.45 V/33 ohm, 0.4 V/10 ohm output "Low sensibility" 1.5 V/150 ohm, 1.2 V/33 ohm, 0.65 V/10 ohm
• Frequency Response: -0.1 dB @ 10Hz / 3-dB @ 50 kHz (output "Low sensibility", 33 ohm load)
• Input impedance: 20 kohm // 100 pF
• Sensibility: 0.67 V in/ 0.33 V out (output "High sensibility", 10 ohm load)
        0.67 V in / 1 V out (output "Low sensibility",33 ohm load)
• Input stage: Pure Class A, ECC83/12AX7
• Output stage: Class A, 2 EL84 triode connected
• Inputs: 1 line RCA, 1 USB
• Outputs : 2 (parallel connected)
• Feedback factor: 16 dB
• THD: < 0.2% @ 1kHz, 0.5V, <0.8% up to 1 V (output "Low sens.", 33 ohm load)
• Absorption: 45 W
• Dimension: 22,5 cm x 12,6 cm x 32,2 cm
• Weight: 6 kg