The Unison Research Triode 25, like its famous predecessor the Triode 20, is a push-pull amplifier that utilizes EL34 tubes in the output stage. The push-pull circuit includes a final stage with two power tubes intended for the amplification of the positive half-waves, respectively, and of the negative half-waves of the audio signal. The task of properly reconstructing the audio signal is then assigned to the output transformer which, thanks to its symmetrical structure, allows for a highly linear signal.
Here are some of the more important and significant benefits of a push-pull structure in this type of amplifier design:
– Higher output power
– Higher efficiency and therefore less heat generated, with positive effects on the durability of the output tubes as well as significant savings in energy costs
– No static polarization of the output transformer, resulting in better performance of this section
To ensure high-quality sound in an amplifier with a push-pull configuration, however, it is essential that all individual amplification stages, especially the two semi-output amplifiers, are carefully designed and constructed to prevent the formation of dangerous and compromising odd-order harmonic distortion. This is even truer for the output transformer.
The new Triode amplifier 25 has experienced a long and painstaking design and testing period despite the considerable experience already gained in the construction of its predecessor, the Triode 20. The Triode 25 can operate in two modes: triode and pentode. The latter is capable of delivering a maximum power output of over 45 watts per channel with a load of 6 ohms with harmonic distortion extremely contained across the entire audio band.
Unison Research Triode 25 Technical Specifications
- Output Stage: Push-pull, ultra-linear, Class-AB
- Output Power: Approx. 45 watt per channel Pentode configuration, Approx. 25 watt per channel Triode configuration
- Output Impedance: 6 Ohm
- Input Impedance: 47 kOhm / 50 pF
- Negative feedback: 5 dB or 1.8 dB
- Valve complement: 2 x ECC83 (12AX7) 1 x ECC82 (12AU7) 4 x EL34 (6CA7)
- Power Consumption: 300 watt max
- Fuses: T6.3A from 100V to 130V T3.15A from 220V to 250V
- Dimensions: 30 cm x 45 cm x H. 20cm
- Net weight : 20 Kg