UNISON RESEARCH SH

Pre owned. In excellent condition. Shows no visible signs of wear. Includes original manual and packaging.

The Unison Research SH is a headphone amplifier that combines the refinement of valve technology with modern digital features, designed to deliver a high-level listening experience with both analog sources and digital music. Its two-stage Single Ended Class A architecture employs ECC83 tubes in the input stage and an EL84 tube in the output stage, both operating in triode mode, producing a clear, natural, and highly musical sound. The volume control is passive, preserving signal purity, while a sensitivity switch allows the amplifier to adapt its output to headphones of different impedances, ensuring optimal performance even at low listening levels.

The SH features two parallel headphone outputs, allowing easy switching between listeners or sharing audio with multiple people without loss of quality. Connectivity includes an unbalanced RCA input for any analog source and an asynchronous USB input compatible with USB 2.0 Audio Class, supporting PCM up to 384 kHz and DSD up to 128x, with resolution up to 32 bits. The built-in DAC is based on the latest generation ESS Sabre chip (ESS ES9010K2M) and incorporates a jitter elimination circuit, galvanic isolation between the USB interface and the conversion circuitry, and a low phase-noise clock powered by a “clean” supply domain, ensuring precise, detailed, and interference-free reproduction.

Performance features include a 110 dB SNR (1 kHz, A-weighted, 192 kHz) and a total harmonic distortion plus noise (THD+N) of 0.008% (1 kHz, -3 dBFS), demonstrating its ability to deliver music with exceptional clarity and dynamics. By combining valve technology with a modern DAC, the Unison Research SH stands as a versatile and powerful tool, ideal for anyone seeking absolute quality in headphone listening, whether from analog or digital sources, in a fully handcrafted product built to last.

Technical specifications:

• USB Interface: asynchronous, USB 2.0 Audio Class; supports PCM up to 384 kHz and DSD up to 128x; resolution up to 32 bits; ESS Sabre DAC with jitter elimination; galvanic isolation between USB interface and conversion circuitry; low phase-noise clock in “clean” supply domain; SNR 110 dB (@1 kHz, A-weighted, 192 kHz); THD+N 0.008% (@1 kHz, -3 dBFS)
• Maximum output voltage: High sensibility 0.5 V/150 ohm; 0.45 V/33 ohm; 0.4 V/10 ohm; Low sensibility 1.5 V/150 ohm; 1.2 V/33 ohm; 0.65 V/10 ohm
• Frequency response: -0.1 dB @ 10 Hz / -3 dB @ 50 kHz (Low sensibility, 33 ohm)
• Input impedance: 20 kΩ // 100 pF
• Sensitivity: 0.67 V in / 0.33 V out (High sensibility, 10 ohm); 0.67 V in / 1 V out (Low sensibility, 33 ohm)
• Input stage: Class A, ECC83/12AX7
• Output stage: Class A, 2 x EL84 triode-connected
• Inputs: 1 line RCA; 1 USB
• Outputs: 2 parallel-connected
• Feedback factor: 16 dB
• THD: < 0.2% @ 1 kHz, 0.5 V; < 0.8% up to 1 V (Low sensibility, 33 ohm)
• Power consumption: 45 W
• Dimensions: 22.5 cm x 12.6 cm x 32.2 cm
• Weight: 6 kg