Hello

Who can give me some info concerning a tube amplifier (no case only chassis) I received recently. There are 8 tubes:

L 63 (2 X 2), 6 J 5 GT/G (2X) and PX 25 (2X and great tubes!). The tubes are placed in line: 2 X L 63 (number 2), 2 X 6 J 5, 2 X L 63 (number 3) and 2 X PX 25 (number 4). Four knobs are placed above the tubes and there are two sorties: one radio, one pick-up..... One electricity cable with 10 different cables in it.... Has somebody any idea?

Thanks very much

Marc Verschooris

Hi,
From the description, you did not get a power supply with that amp, and either it is set up (as mono-block push-pull, or stereo single ended amps), it should have enough gain for magnetic phono cartridges.

Does it appear to have large diameter inductor(s) on the output side of the PX25's? If so, this is likely a WWII through Korean war era RF linear amplifier from a transmitter, which could be easily modified to audio use. If it does not, then it is more likely an audio amplifier that could date from WWII through to the Sixties. Military cloth wire insulation generally will be lacquered quite heavily- if there is no other marking on the amp to be found, the wire insulation, and the type of small value caps will help to ID it as military surplus, or just an amp that was not made for military use.

The PX25's I cannot find a cross reference to, so I suspect British, Australian or Canadian origin. From the tube specifications for the PX25's, you can determine what voltage you can to supply to them. If the plate voltage supplies are split, you can use 250 volts on the pre-amps and driver stages if the voltage ratings of the capacitors permit it.

Your only problem is going to be finding a suitable output transformer if it (or they in the case of it being stereo) are not present (without the tube specs at any rate.).

: Hello

: Who can give me some info concerning a tube amplifier (no case only chassis) I received recently. There are 8 tubes:

: L 63 (2 X 2), 6 J 5 GT/G (2X) and PX 25 (2X and great tubes!). The tubes are placed in line: 2 X L 63 (number 2), 2 X 6 J 5, 2 X L 63 (number 3) and 2 X PX 25 (number 4). Four knobs are placed above the tubes and there are two sorties: one radio, one pick-up..... One electricity cable with 10 different cables in it.... Has somebody any idea?

: Thanks very much

: Marc Verschooris