Unison Research Triode 25 [Black Edition] Integrated Tube Amplifier

Unison Research® is celebrating with a special edition of our most successful products: Simply Italy, Triode 25 and S6. The Black Edition boasts advanced technical and sonic performance, featuring a new cosmetic design with a piano black wood front panel, black gun metal finish and updated lettering graphics.

To improve the Triode 25 we worked on its strengths and we went even further to achieve higher sound quality. The circuitry has been revised in the signal path and power management, again surpassing the milestones already achieved in the Triode 25. We reduced the distortion and increased the power.

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 our most premium equipment. We’ve also paid extreme attention 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.

All the new Black Edition series are equipped with 3 digital inputs USB,SPDIF and Toslink

To improve the Triode 25 we worked on its strengths and we went even further to achieve higher sound quality. The circuitry has been revised in the signal path and power management, again surpassing the milestones already achieved in the Triode 25. We reduced the distortion and increased the power. 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 our most premium equipment. We've also paid extreme attention 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 Triode 25 Black Edition amplifier is able to meet the needs of the most demanding users, featuring:

• Triode and Pentode working mode (30W and 50W);
• Bias adjustable;
• Feedback adjustable in two positions;
• Unfiltered SUB output that maintains the sound timbre of the amplifier designed to be connected to active subwoofer;
• Input selection circuit implemented using micro relays and Return GND technology;
• in addition to the 3 analogue inputs, inside the amplifier there's the new 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.
  

Triode 25 Black Edition uses 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. Triode 25 Black Edition can operate either in triode or pentode mode. With this new design we reduced the distortion and increased the power by 20% in Triode mode and 10% in Pentode mode.

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. 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. 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 during the specific listening session. 

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. 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.

Features

• Triode and Pentode working mode (30W and 50W)
• Revised circuitry 
• Bias adjustable
• Unfiltered Sub output 
• New built-in 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.
• Made in Italy

Specifications

• 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

Support

• Manual
  
• Black Edition Whitepaper