A very simple, but useful PCB. A power supply for the Muffsy Relay Input Selector (or anything else that can be powered by 5V DC/1A):

While there are lots of quality kits for preamplifiers, I have never really found a decent way of adding more inputs to a preamp. The existing ones are either of dubious quality, spec'ed like a spaceship, or both.

So I decided to make my own input selector. With relays. And an ESP-32 module! A year,...