Switched Jack True Bypass Wiring

[nickbungus]

Hi Guys

I recently built the ToneLab MXR Noisegate clone.  It works fine and is great but I'm struggling to get it to work in the enclosure.  I always use the following True Bypass wiring diagram when enclosing:



But last night I didn't have any Switchcraft #12b style stereo jacks, but I did have lots of these:



I believe I correctly identified my Ring, Sleeve and Tip (although I had to guess the ring as I didn't have a male stereo jack to test continuity).  But alas, it didn't work.  The bypass works but when engaged I'm not getting the LED and no audio.

I haven't had too much time to debug but I've arrived at work and its really niggling me.

So, really I have 3 questions:

1)  Can I use this type of socket for true bypass wiring?

2)  If so, which pins should I be using?

3)  What's the best way of identifying the pins on the socket?

Thanks as always.

[nocentelli]

The contact on the diagonally cut corner is the sleeve/ground connection: The other four contacts are ring, switched ring, tip and switched tip. The "switched" versions are in contact with the respective counterpart until a jack is inserted, whereby they will be disconnected by the sprung contact being pushed clear. The normal ground, ring and tip should be used. The easiest way to identify which is which is to peer inside, inserting a jack to see what happens and gaining a better understanding of how the socket works.

The switched contacts are useful for expression or remote switching sockets, e.g if no exp pedal is connected, an internal connection is automatically made e.g. to connect an onboard pot instead. I've also seen the switched tip connected ground so the input of the effect is grounded if no instrument is plugged in.

[nickbungus]

The "switched" versions are in contact with the respective counterpart until a jack is inserted, whereby they will be disconnected by the sprung contact being pushed clear.

I think this was the bit I didn't get.  I must have used the switched ring.  I take it this would explain the symptoms?

Thanks Nocentelli!

[nocentelli]

Yes - If you used the switched ring there would be no battery negative connection to the circuit when a jack is inserted so no audio, no LED.

[nickbungus]

Thanks again Nocentelli.

I love this forum.  I don't understand anything, but I do love it

[duck_arse]

the type of socket you use has no bearing on the truth of the bypass, it just gets stuff in and stuff out.

you can find the ground connection easy with your meter, one end is the metal bit out the front for the nut, find which of the lugs connects with yr meter. seeing as a stereo socket will have 2 dingers inside, get yr mono plug and push it in till the tip picks up the first dinger, which will be the ring connection. now meter from the jacks tip to the whichever lug, then push the plug in to pick up the second dinger, meter, lug, diagram, happy.

or, as nocentelli says, peer up the arse of the jack, see what is, so to speak.

[anotherjim]

The R connection is contact #4 on the jack diagram. You don't need a stereo jack to test it, a mono jack should short R-S (or 4-1) only when it's inserted. R-S will be ARSE without the vowels

[duck_arse]

R-S has always been rat shit, in the vernacular.

[bluebunny]

R-S has always been rat shit, in the vernacular.

I once worked in a place where a colleague's name was R. S. Hole.  No, really...   

Apologies.  please carry on...

[blackieNYC]

FWIW, these switching are great for expression pedals as mentioned here, or in the geofex article on replacing pots with expression pedals.  Also, they are great in a multiple-fx pedal with several circuits, each with its own stomp, By using such a switching jack (mono would be all you need) as the input jack for each switchable "pedal", and a simple mono jack at the output, you can have access to each pedal, for splitting or blending purposes, but but tying that input jack switch to the output of the previous effect, you can string all the effects consecutively (in mono) without a patch cable, leaving all jacks empty but the first in and the last out.
    These jacks cost a little more. When you get some mono jacks someday you should switch these out and do something wacky with them.