The 12E1 Mark 1
This amplifier was designed to test various valves of the 12E1 family namely 12E1, S11E12, 12E14 etc. It is shown here with 12E1s in place. The top caps plug into 4mm sockets and the anode circuit wiring caters for the series.
Using 6C4 input, 12AU7 amplifier and phase splitter EE180CC as drivers. The CRT is for amusement only, providing two types of display to the audio signal.