I want to create a passive device with two MIDI inputs and two MIDI outputs, with a switch that has two states. In the first state, input 1 is connected to output 1, and input 2 is connected to output 2. The other state swaps them, with input 1 connected to output 2 and input 2 connected to output 1.
Each input/output has a positive pin, a negative pin, and a ground/shield. I figure I can just wire the grounds together, but I'm trying to figure out if it's possible to shuffle the positive and negative inputs/outputs around with a DPDT switch and some diode trickery, or if I need something less common like a 4PDT switch (or something else entirely).
I would love to figure it out with just a DPDT switch if it's even theoretically possible, but I'm a newbie at electrical engineering, and I don't know very many of the seemingly common tricks to control flow with diodes and such.
Best Answer
You need 4PDT switch, because MIDI is a balanced current loop. So two pins must be switched from each connector, and you have two connectors.