Special Input Sign in Schematic

[Nobisayzhoi]

On most pedal schematics I see, they write the input like this. Could someone tell me what this means and what to do because I am confused.

[duck_arse]

that is a schematic representation of a tip/ring/sleeve jack socket. the box connected to the striped ground symbol is the sleeve, always ground. the other two "dingers" are the metal spring-fingers that push against the ring and tip of a stereo jack plug, when inserted. [I'm not 100% on the convention as to which is tip and which is ring in isolation - the rest of the circuit usually clarifies.]

if a mono jack plug is inserted, it will short the ring dinger to the sleeve, which is sometimes useful.

[italianguy63]

that is a schematic representation of a tip/ring/sleeve jack socket. the box connected to the striped ground symbol is the sleeve, always ground. the other two "dingers" are the metal spring-fingers that push against the ring and tip of a stereo jack plug, when inserted. [I'm not 100% on the convention as to which is tip and which is ring in isolation - the rest of the circuit usually clarifies.]

if a mono jack plug is inserted, it will short the ring dinger to the sleeve, which is sometimes useful.

The "ring" is the contact closer to the square box (ground).

MC

[ElectricDruid]

+1 agree. It's a stereo jack, and the connections working left-to-right are sleeve, ring, tip.

[PRR]

[EBK]

Paul, you always impress me with your graphical skills (mostly the speed at which you find or create the perfect image).  Sometimes a picture is the best answer.

[PRR]

> mostly the speed at which you find or create the perfect image

Timeline:
July 18, 2018, 11:26:54 AM
July 18, 2018, 06:45:13 PM

7 hours sweating over wet oil paint, scanning, compositing pixels one by one....  no, 1 minute in Google (few clear pics of jack fingers) plus stealing the OP's image.

[PRR]

One reason the symbol does not look like the part we buy is that we buy the cheap parts.

The whole plug system comes from Telephone Switchboards. Every phone in the city (or a large part of a city) came up in one room with a few operators. The jacks had to be *close together*.


Instead of the 2-bit "Littel-Jax" (not yet invented), telcos used "open frame" designs with the terminals way out back, "M-Jax" or "Navy Jacks", a buck a pop. An array of hundreds of these things is not too hard to wire (unlike a mass array of LittelJax which won't pack as dense). For one thing the boss and screw mount means they all face the SAME way and busing is practical. Also they were mounted on oak or phenolic panels and the sleeves were totally isolated.


The open frame allows mounting the contacts in stacks, which means you can stack additional fingers to switch additional circuits. Light an In-Use light *only* if the plug were inserted, so dead calls would be disconnected promptly.


As you can now see, the symbol "IS" the jack, except the ring finger rotated to the bottom for clearer clarity.

This became popular, but never cheap, so SwitchCraft's killer product was the 1/4" plug with simplified shape and the 2-bit panel jack with the contacts bent back toward the front. This does work better when you have few jacks in a small box, no long-frame eating interior space. (Some longframe jacks were deeper than some of your pedals are wide.)

[merlinb]

Could someone tell me what this means and what to do because I am confused.