Do people use Google any more?

I did a quick check, and found a similar question asked on another forum.

Long discussion, suggesting various problems, also some solutions.

So, check this:

http://forums.musicplayer.com/ubbthreads.php/topics/2330231/Does_a_simple_MIDI_on_off_box_

May help?

Geoff

It's not commercially available, as far as I know, but you could make one easily:

1. Go to a computer store (or online) and get an old-school AT keyboard extension (same DIN-5 plug as MIDI)
2. Use any switch you like to interrupt pin 4 and/or 5 (one pin is sufficient)
3. Mount as desired

https://www.midi.org/specifications/item/midi-din-electrical-specification

Do people use Google any more?

Yeah. We do. Here I am two years later finding my own post. Were you suggesting that I didn't even try to find this answer? Well, I did. I looked everywhere. Here I am again. If you don't have an answer... don't answer next time, Geoff.

This can be assembled from DIY parts in 15 minutes, using a drill with wood bits and a soldering iron. All it takes is a suitable plastic or wooden box, a flush-mounted (through the hole) on-off switch, like push-button latching switch, horizontal multi-pole single-throw switch etc. (with enough pins/poles to disconnect the required number of MIDI signals with a single push), flush-mounted 5-pin DIN 41524 sockets, and some isolated copper wire.

I built a 1 input to 2 output switcher using 3 jacks and a little switch. I can use it with 1 input and select between 2 outputs, select between 2 inputs to one output, or as a simple on/off switch. This is not perfect. You probably want to make sure that devices are not depending on Active Sensing messages. Running status could sometimes cause a funny error. If you switch while a note is sounding before sending a note-off you can end up with a stuck note. But if you make the change while no instruments are playing it generally works okay.