PP5/400 Mazda audio output valves thick top mica and bottom getters PX25 DO24 equivalent

Description

The PP5/400 is a directly heated power triode made by Mazda Ediswan.

It was first introduced in 1931.

The PP5/400 is for use in the output stage where a 450 Volt supply is available.

The PP5/400 has an output of 25 Watts and was able to deliver music or speech in a large hall.

The plate structure is a Mazda patented design.

Mazda PP5/400 Characteristics

Filament Voltage 4 Volts

Filament Current 2 Amps

Anode Voltage 400 Volts

Anode Current 62mA

Negative Grid – 32

Mutual Conductance 7

The Mazda PP5/400 is equivalent of Marconi Osram PX25 and Mullard DO24

We attempt to cover the three version of the Mazda PP5/400 as follow:

1) Thin top mica with getter at bottom

2) Thin top mica with getter on top

3) Thick top mica with getter at bottom

 

Pair of Mazda PP5/400 with thick top mica and getters located at bottom of envelope.

Top is clean and both valves look superb!

Tested with AVO VCM 163:

Mazda PP5/400 tested 53mA 100%

Mazda PP5/400 tested 52mA 100%