Wiring a stereo TRS socket as a mono output

Question

I'm designing a product that provides mono audio output via a 1/4" SN49B12B board-mounted socket.

This socket is actually a stereo socket, but I'm wondering if simply wiring the ring and sleeve pins together to ground will effectively make it a mono socket?

Are there any issues with this approach from a product design / durability / robustness perspective? One concern I had was that when plugging, the ring will connect the cable to ground earlier than if there was no ring present - would that create any extra plugging noise or anything like that?

The user will, of course, be using mono TS plugs.

Answer 1

Whether the jack plug gets shorted or not depends on the geometry of the insulation on the plug and the width of the contacts on the socket. Assume the worst - whatever that may be in your design.

^{simulate this circuit – Schematic created using CircuitLab}

You are free to wire the socket any way you desire.

a) This will work with a mono or stereo jack wired tip and sleeve. A stereo plug will have the ring floating and may cause hum in that channel (usually the right).

b) Will work similarly and has the advantage that if a stereo lead is plugged in that the channel will be grounded rather than left floating and producing a hum.

c) This won't work if a stereo lead is plugged in as there is no ground connection.

It's your choice.