Such a thing as a 4-conductor 1/4" phone plug?

[Mark Hammer]

We have T-S plugs/jacks, and T-R-S "stereo" plugs/jacks.  There are also 4-conductor 1/8" mini phone plugs/jacks.

Does such a thing as a 1/4" T-R-R-S plug/jack exist?  I ask because someone gave me a little 3-switch footswitch unit for a Fender amp, that uses diodes to do what it needs to do with a stereo plug/jack.  I thought "Such footswitch units could be put to very flexible use with greater ease if each stompswitch (latching or non-latching) could be used to make a simple connection to ground."

It would seem from a cursory search that the TRRS standard only exists for 3.5mm plugs/jacks.

[PRR]

I bet it will be easier to do the convoluted logic to make >2 things happen on a TRS than to find a TRRS in 1/4".

[Jay]

Yes I think there are 4 conductor 1/4" plugs/sockets.  Used on aircraft for headsets - cans plus mic.

[italianguy63]

Omit..

[EBK]

They DO exist.  Amphenol Nexus Technologies manufactures them, and Mouser stocks them.  Cheapest is $9.57 USD....
http://www.mouser.com/ProductDetail/Amphenol-Nexus-Technologies/TP-120-5/?qs=sGAEpiMZZMv0W4pxf2HiV3TUc6umO4VrYFBRWAmR5xc%3d

[italianguy63]

What about a female panel jack?!

MC

[EBK]

A jack:
http://www.mouser.com/ProductDetail/Amphenol-Nexus-Technologies/TJ-120/?qs=sGAEpiMZZMv0W4pxf2HiV3TUc6umO4VriDDpp3R30WM%3d

[davent]

$13 & $18 cdn for Mark and everyone else in the great white north.
dave

[italianguy63]

A jack:
http://www.mouser.com/ProductDetail/Amphenol-Nexus-Technologies/TJ-120/?qs=sGAEpiMZZMv0W4pxf2HiV3TUc6umO4VriDDpp3R30WM%3d

Thanks!  (Ouch)

[reddesert]

By the time one is going to require special TRRS plugs and jacks, meaning a cable that looks like a 1/4" cable but is different from every other 1/4" cable, why not change to a different connector entirely? Otherwise you have a substantial risk of user error, plugging in the wrong cable. This could be mitigated by hardwiring the cable to the footswitch and using the TRRS jack only at the amp / equipment to be controlled, but even so you're inviting someone (including yourself) to eventually plug a normal TS or TRS 1/4" cable into that jack.

I would consider something like a 5-pin DIN MIDI cable, which has the advantage that if you lose a cable or need a longer one, just get another standard MIDI cable. The nuisance is that the jack requires a larger panel hole.

[ElectricDruid]

If you do that, someone's only going to plug a MIDI keyboard into it, and then complain loudly that it doesn't receive pitchbend!

= I don't think you can win...

It's worth thinking about what would happen if someone did do the wrong thing. If someone plugs a standard TS 1/4 jack into this amazing TRRS jack that we've managed to track down then actually nothing much bad happens. Two of the switches are "on" (shorted to ground). Since that's one of their normal conditions, I don't see it as much of a problem. I'd be more concerned about what happens when various combinations of things get shorted as you stick the plug in, but that should be easy enough to protect against.

I reckon PRR's bet with just figuring out the logic required to do it with a TRS is fairly safe. You could do four switches with 3 pins if you were reading them with a PIC, for example. You'd switch the various pins back and forth between internal pull-ups and ground, and then read them as inputs. Then you use the PIC to switch whatever it was that you were switching. It's "charlieplexing" in reverse, essentially.

Tom

[blackieNYC]

used to fix ADATs.  I always thought the little remote was very cool.  1/4" TX plug, resistor network keypad with all those buttons:
https://www.dnd.utwente.nl/~mrjb/electro/lrcdecoder/

[anotherjim]

I think you could use plain logic. I expect it was intended to feed 2 input pins with pull ups. So it's normally 11, two of the switches give 01 or 10 and the switch with 2 diodes (anodes to each T & R) gives 00. It's just a 2 to 4 decoder 74xx138 or similar needed. After that you can have edge triggered D or J-K flip-flop latches. Selected decode output (#0 to #2) goes low from normally high when switch pressed, when it goes back high on switch release, the flip-flop toggles. Should be possible to use latching relays instead if you want.

With 2 to 4 decoding, the 4th (no switch pressed state output is #3) will change (go High from normally Low) when any of the 3 switches are operated, which might also be a useful control.

[Mark Hammer]

At the prices folks have noted, I think I'll pack that little pipe-dream away.  Funny how something which is so much harder to do in a smaller form-factor is neglected and pricey at the size where it's easier to do.

[digi2t]

How about converting to DIN instead? I'm working on a project now using a 9 pin mini DIN. The chassis jack and plug came to about $5. DIN plugs and jacks in general are still pretty cheap.

BTW, my Egnater Tourmaster uses an 8 pin DIN arrangement for switching between 4 channels, reverb on/off, and loop on/off.

[Mark Hammer]

There's no compelling reason to use (or not use) any particular connector.  It was just one of those things where I thought "Boy, this would be a breeze if I could use a 4-conductor jack and plug", and I got curious.