In Barn for Review: Unison Research Unico 90 Integrated Amplifier

Dual Mono, Zero Feedback, 2-Stage Valve-MOSFET Integrated Amplifier,  baby.

Unison Research has two lines of electronics—the Unico Series that’s comprised of hybrid amplifiers and integrated amps along with preamps, CD players, and a phono stage. The Tube (i.e. Valve) Series that includes integrated amplifiers, the Reference Pre/Power combo, and two phono stages.

The dual mono Unico 90 combines a pure A class tube input stage employing ECC83s and ECC81s directly driving the Class AB MOSFET output stage using zero, as in none, global feedback. for 100 Watts of output power into 8 Ohms and 160 Watts into 4. There are a total of 6 inputs (3x RCA, 2x XLR, 1x RCA ‘Bypass’ input for bypassing the preamp stage) and 2 pair of speaker binding posts per side for bi-wiring. There’s also a single-ended RCA Sub Out and Monitor Out.

The simple front panel houses an input selector knob, an equally sized volume control, and in between corresponding LEDs and IR receiver dead center for the included remote. The power switch hides around the right side.

a peak inside the Unison factory

If you’ve read my recent factory tour, you already know that Unison builds all of its products by hand in their factory near Treviso, Italy which is also near Venice in the North. Unison is a family affair, founded in 1987 by Giovanni Maria Sacchetti who designed and built the first audio amplifier to employ the 845 triode. I wrote a glowing review of their Simply 845 last year that carries on this 845 triode tradition.

another peak inside the Unison factory

I very much look forward to powering up the Unico 90 to see how Unison’s hybrid power makes music sing.

Unison Research Unico 90 Integrated Amplifier
Price: $5499 in Silver, $5499 in Black
Company Website: Unison Research
US Importer Website: Fidelity Imports


Output Power: 100+100 W RMS su 8Ω / 160+160 W RMS su 4Ω
Frequency Response: -1dB @ 12Hz e 45kHz -3 dB
Input Impedance: 21Kohm // 300pF
Input Sensitivity: 860mV RMS
Input Stage: Pure A class, double triode totem pole ECC83 and parallel totem pole ECC81 This single stage due to the particular circuitry is able to amplify the input signal and drive directly the power stage.
Output Stage: Class AB thermostable, complementary Hexfet (3 pairs for channel)
Number of Stages: 2, This amplifier due to the particular circuitry is realized by only two stages: input stage and output stage, and use only local feedback
Input: 6 line (3 unbalanced, 2 balanced, 1 “bypass” unbalanced)
Line Outputs: 1 tape, 1 sub (volume controlled)
Output Connectors: 4 + 4 bi-wiring
Global Feedback Factor: 0 dB
THD: < 0.15% @ 1kHz, 1 W | < 0.5% @ 1kHz, 10 W
Output Resistance: <0.4 ohm, resistive on all audio frequencies
Power Consumption: 550 W (at max power on 8 ohm)
Dimensions: 43.5cm x 44 cm x 18 cm h
Net Weight: 20 kg