EM11 radio tuning indicator (magic eye) as a VU meter

An old EM11 "magic eye" vacuum tube connected to a PC sound card through a small amplifier circuit on the tube base, which converts the line output of the soundcard to a voltage swing of 0 to -20 volts, which is required for the grid.

Видео EM11 radio tuning indicator (magic eye) as a VU meter канала Jozef Bogin