• Transistor Tickler
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Are these jacks supposed to have two or three connections?

If they are supposed to be three wire then how would you wire them up?

Thanks in advance!


  • Electron Doctor
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I canít tell by the description if it is similar to the 112A or 112B. Basically, itís a switching style jack. Easiest way to tell if it is an A is to use a DMM to test for continuity between two of the lugs, then put a cable into the jack and test for continuity between the tip of the jack and one of those two lugs. The lug with continuity is the tip lug. The ground lug would be that third lug (you can always use the DMM on the cable sleeve to verify).  You could also visually look for the connections.

You can use the jacks as regular input/output by using the tip and sleeve lugs as normal. They can also be used as part of an effects loop. The send signal would go to the tip lug, the third switch lug would be wired to the switch lug of the return jack, and the tip lug of the return jack connects to the return signal of the board.
Build guides of my original designs and modifications here


  • Transistor Tickler
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Just to expand on Chris's (excellent) reply: a mono enclosed jack should only have two lugs if it's of the standard type.  So it sounds like you got a switched mono jack, or they sent you a stereo jack by mistake (or because they've mislabeled their parts listings).  Either seems possible (because that parts listing is really crappy), so it's important that you suss out which one you've got.  Note that a switchcraft enclosed with a 2 at the end of the designation is generally a stereo jack so it's possible that that's what you've got.  I'd guess switched, but make sure you rule out stereo.

First, check if it's stereo by looking into the interior of the jack for a second flange that would hit the ring of a stereo jack.  If that's not there, then you probably have a switched mono jack--if it is then it's stereo. Follow Chris's advice to use a continuity tester to find which lug is switched on when the jack is engaged and which one is the ground.  Just wire the former as your tip and the latter as your ground and you can wire it up as normal and should be good to go.