PX25 VR40 Military Grade balloon early type CV1040 DO24 NR47 matched quartet tested 100%

Description

The PX25 is an output valve like a PX4 but with higher output and Anode Voltage.

The Marconi Osram PX25 is a power amplifying valve of extremely high efficiency designed with a large power handling capacity to supply considerable undistorted volume.

It is intended for use in the last stage of Low Frequency Amplifiers where provision is made for adequate high tension supply. When operating the PX25 valve, arrangement should be made for sufficient air circulation to prevent over-heating

Filament Voltage 4

Filament Current 2 amps

Anode Volts 400

Grid Volts -31

Anode Current Average 62

Anode Dissipation 25 Watts

Mutual Conductance  mA/V 8

AudioMagical introduces most of all PX25 type made from 1932 up to the 1960s

The VR40 is a special limited edition of the more common PX25.

It was designed for military use and one single valve could give up to 5 watts.

When operating in push pull the VR40 is capable of about 20 watts.

Valves feature ribbed plate, large getter with all filaments perfectly hooked up, excellent sound with code on glass .

In mint excellent condition and working order

Tested with AVO VCM 163

VR40 PX25 {1} 48mA 100% emission mA/V 7

VR40 PX25 {2} 49mA 100% emission mA/V 7.1

VR40 PX25 {1} 47mA 100% emission mA/V 7

VR40 PX25 {2} 47mA 100% emission mA/V 7.1