Here is a very rare opportunity to own this beautiful TRON Type PX25 SET amplifier. The Type PX25 is in excellent condition and comes with the legendary Partridge output transformers, NOS driver and rectifier valves and KR PX25s.
This was made for the original owner in 1998 and has been own by him since. I have just bought it back in part exchange against a new Tron Voyager so the Type PX25 needs to find a new home.
Here is some text from the time it was made:
The Type PX25 amplifier is named after the famous PX25 triode it uses in its output stage. The PX25 valve was designed in the 1930s, and regarded amongst many audiophiles world-wide as being a finer sounding valve than the 300B. Amplification is achieved by a 5842 single triode driving the PX25 directly heated triode. The PX25 is coupled to the loudspeaker by a specially made transformer supplied from Partridge. Again there are no capacitors in the signal path what so ever. The power supply is rectified by an U18/20 valve and is in turn connected to a pi filter. To eliminate hum completely which is often a source of aggravation from horn loudspeaker owners DC heating is used on the PX25. Measured hum on the output is of the order of 5mV peak to peak. This is completely inaudible even on loudspeakers of 107dB efficiency. Custom made components are used throughout the Type PX25 and these are hard wired between stages. High quality copper wiring is used through the amplifier and is implemented using traditional hard wiring techniques. The metalwork is based around a CNC machined top plate anodised in natural aluminium finish. Aluminium is used throughout the chassis with a custom extrusion for the case; the transformer covers are also made from aluminium. Connections to the loudspeakers are via high quality 4mm binding posts. Two sets are provided per channel to facilitate bi-wiring. Input connections are via conventional phono/RCA sockets. The finish is piano black for the case and transformers covers. The top and bottom panels are brush finished natural anodised aluminium.
The PX25 amplifier has evolved through the marriage of pre-war technology with modern-day electronics. In spite of its generous dimensions this amplifier produces 5 watts of glorious single-ended power from at input signal of 1.5Volts. Like all TRON amplifiers it is completely free of any feedback, and has been specifically designed to drive efficient loudspeakers of 95db and above.
Input: 1 x RCA – 100K ohms
Sensitivity: 1.5 volts
Output: 2 x 5 watts/channel
Frequency Response: 5Hz – 38KHz +/-3dB
Output connections: 2 x sets of 4mm binding posts configurable for 4, 8 or 16 ohms
Mains voltage: 115v – 230v – 240v
power consumption: 250watts
Valve compliement: 2 x 5842, 2 x PX25, 1 x U18/20
Dimensions: 260mm(w) x 170mm(h) x 350mm(d)
Finish: Black and Silver.
Please call (01895 833099) or email