input/output basics

[mcm1221]

So, turns out taking college physics of electronic circuits is zero help for real world circuit building projects.

That being said, have 3 questions:

Where do the negative/ground wires connect to the input/output jacks?
Where do the positive wires connect?
Where do these wires connect to the 9V battery.

Take the Arbiter Fuzz Face schematic (which I will not post because I believe this forum has a rule against posting schematics, might be wrong though), I'm having trouble figuring out where all the terminals connect to the jacks and the battery.

Any help would be appreciated. Thanks.

[52 Bill]

That being said, have 3 questions:

Where do the negative/ground wires connect to the input/output jacks?
Where do the positive wires connect?
Where do these wires connect to the 9V battery.

All jacks have 2 or 3 basic connections. Some have additional switching contacts that can be used to connect the tip or ring contacts to other points or to ground.

The standard 2 contact 1/4 inch plug and jack have the tip and the sleeve or shell. The tip is the end of the plug and the sleeve is the basic body of the plug. In audio circuits, the tip contact is the hot contact and the sleeve is the ground. In 3 conductor circuits the sleeve is segmented into two parts, creating a ring contact.

If you look at the jack you will easily see the connection for the sleeve contact, it is usually connected to the threaded mounting section. Look at the contact for the tip and follow the metal piece down to the mounting section and you will see which terminal it connects to. The same will be true of the ring contact if it is a three conductor jack.

When the battery is turned on by pluging in a cord it is usually switched on by connecting the battery's ground connection to the circuit ground. To do this most pedals willl use a three conductor jack as the switching jack. The side of the battery that needs to connect to circuit ground is connected to the third or ring contact. Because the ring contact is created by segmenting the sleeve of the plug, its contact will connect to the sleeve of a two conductor plug when it is inserted into the three conductor jack.

So if the circuit is powered by a negative voltage like a PNP Germanium Fuzz Face, the battery negative lead goes to the circuit and the positive lead goes to the ring contact of the input jack. When a standard two conductor guitar cord is inserted into the input jack the ring contact and therefore the battery positive terminal is connected to ground via the sleeve contact.

Just a little examination of how the jacks are constructed will show you how it all works.

[Enzo]

Hi, welcome to the forum. You must not have read much here if you think we don't post schematics. We even have a schematics request section. One of the most common requests in here is for someone to post the schematic of whatever they are talking about.

[mcm1221]

Thank you.

[Steve Conner]

Jack Orman's schematics show the battery and jacks too.
http://www.muzique.com/schem/fuzzface3.gif

(That's a NPN one, so the battery is connected the other way round compared to the classic Arbiter circuit, but everything else is the same.)

A popular way of building DIY pedals uses metal Switchcraft jacks screwed into a diecast metal box. The box becomes ground and is connected to the sleeves of the jack plugs. Your circuit board will have its own ground rail, and to complete the ground circuit this should be wired to the sleeve terminal on one of the jack sockets.