This is a switching method I developed in the 90's for switching audio video radio and other equipment. Today I do use micro controllers but on high end tube gear I like to run all discrete component circuitry. All have been tested and run by me at one time or another .
The 3 way 4 mode I used in a guitar overdrive pedal and as switching for model rockets and fireworks. This switch has 3 buttons only allows one selection at a time and to bypass/turn off press the active mode button and all go off.
Give Feedback please.
I can remember input selector on my old soviet amplifier. It has has so noisy switching. I was afraid touching it. One day I tried to repair it and dig a schematics. Audiotechnica U-101-Stereo