PX25A Marconi Holy Grail balloon V shaped base large anode DA30 300B alike extremely rare pair tested 100%

Description

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

Pair Marconi PX25A power amplifying valves of extremely high efficiency designed with a large power handling capacity to supply considerable undistorted volume. 

They intended for use in the last stage of Low Frequency Amplifiers where provision is made for adequate high tension supply. When operating the PX25A 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 -100

Anode Current Average 62

Anode Dissipation 25 Watts

Mutual Conductance  mA/V 3.7

 

Tested with AVO VCM 163

PX25A Marconi {1} 68mA 100% emission mA/V 3.7

PX25A Marconi {2} 69mA 100% emission mA/V 3.7