Unison Research Triode 25 Black Edition

Unison Research has taken the Triode 25 even further to achieve higher sound quality. 

• Through component improvements, the power has been increased and the distortion decreased.
• Thanks to its specially designed circuit the power valves of Triode 25 Black Edition can operate either in triode or pentode mode.
• The input selection circuit now utilizes the same advanced technology found in Unison's most premium equipment.
• Extreme attention has been paid to the design of ground paths and channel separation to ensure optimal performance. The valuable audio signal, where possible, travels protected in high-quality coaxial cables.
• The addition of the DAC3. In our opinion is very good, and an excellent way to add a secondary source like a streamer or transport without the additional box (es), cables and accessories.

Triode Or Pentode

The Triode 25 Black Edition can operate either in triode or pentode mode. With this new design the distortion is reduced and power increased by 20% in Triode mode and 10% in Pentode mode. The Triode 25 Black Edition has an output power of 50W in pentode mode and 30W in triode mode (vs. 45W and 25W of the standard version). Pentode mode is an “ultralinear” configuration that achieves the higher power of pure pentode mode but with a much higher sound quality, while in Triode mode the output power of the amplifier is lower, but the sonic character takes on the quality typical of triode.

Adjustable Bias

The bias of the output stage is fixed but partially adjustable by the user. The bias selector switch allows the user to control the bias of both the left and right channels and allows the power valves to operate in the best conditions at all times.

Adjustable Feedback

The feedback control switch allows user adjustment of the amount of feedback applied to the amplifier`s internal circuit (from 10dB to 12dB). A difference in the level of feedback can provide an improvement in the interface between amplifier and loudspeaker. Feedback affects the amplifier`s parameters, such as damping factor, bandwidth and distortion, therefore the user will choose the position that sounds the best.

Power Supply Enhancements

The power supply system has been significantly enhanced, decoupling the anodic voltage of each valve to ensure their independence. Additionally, strategically placed polypropylene capacitors have been added to the power supply, improving transient response and signal dynamics.

Input Section Improvements

The input selection circuit has been meticulously designed to minimize noise and optimize channel separation. Micro relays with gold-plated silver contacts ensure stable contact over time and prevent crosstalk with other non-selected sources connected to the amplifier. Furthermore, the return grounds of the inputs have been implemented using Return GND technology, guaranteeing an individual path of reduced length for each input. 

Additional Features

• Gold Lion tubes exclusively - two ECC83 and one ECC82 triodes for the preamplifier section and four KT77s for power amplification. The carefully matched Gold Lion tubes ensure superior technical and acoustic performance.
• Unfiltered SUB output that maintains the sound timbre of the amplifier designed to be connected to an active subwoofer
• DAC3, which adds 3 more digital inputs USB (PCM up to 384kHz, DSD native up to 256x and DoP up to 128x), Tos-link and SPDIF up to 192kHz as standard.

Tech Specs

• Output Stage: Push-pull, ultralinear, Class-AB
• Output power: 50W pentode mode 30W triode mode
• Signal valves: 2 x ECC83 Gold Lion and 1x ECC82 Gold Lion
• Output power valves: 4 x KT77 Gold Lion in push pull configuration
• Relay Input Selector with Return GND Technology
• Bias adjustable
• Working mode: Triode or Ultralinear with tap at 60% (power valves)
• Inputs: 3 line RCA, 1 USB, 1 SPDIF, 1 Toslink
• Outputs: 1 subwoofer RCA (stereo), 1 line out
• Feedback: 10dB to 12dB selectable
• Bandwidth (-1dB): 10Hz – 50kHz
• Dimensions (x y z): 30 x 45 x 20 cm – 12 x 18 x 8 inch
• Weight: 20kg