6Z4J, B7G, RECTIFIER VALVE, FOR LITTLE BEAR AMP, T10, NOS

6Z4J, B7G, RECTIFIER VALVE, FOR LITTLE BEAR AMP, T10, NOS

The 6Z4 is a valve rectifier which is  popular as a cost effective rectifier valve for use in high end audio amplifier and guitar amplifiers

This item is the J suffix - Jun Dui, which is Chinese for "army).

6Z4-J was the highest grade Chinese rectifier and was made in the Beijing factory for the army. These were produced from 1981d.

The valve has the same characteristics as an American 6X4 or European EZ90 but has different pin connections so is not a direct replacement without re wiring the socket.

The differences are on pins 5, 6 & 7 

The 6X4 and EZ90 are wired
Pin 5 un connected,
Pin 6 is anode 2, 
Pin 7 is cathode.

The 6Z4 -J
Pin 5 cathode, 
Pin 6 un connected, 
Pin 7 anode 2