As work on the device crossed the equator, I began to think about the interface, microphone amplifier, headphones, mixing signals and switching it all.

It was also necessary to come up with a design.
All this made me sad until I suddenly realized that there are devices that combine these functions.
And called mixing consoles.
I quickly found a suitable model and I hope it will close my problems (except for happiness and money)))
Model and photo will be added in the next few minutes.