Guitar Wiring 101

Posted on by Richard Irons

For many players, a change of pickups is one of the very first steps into modding guitars. It’s reversible, it’s not too hard, and it has an immediate impact on your tone. However, it’s still possible to get yourself into a bit of a mess if you don’t have a basic understanding of why you’re doing what you’re doing. This is the first in a short series of blog posts that will take you from the very basics, up to where you will probably feel confident enough not only to follow the schematics you find on the internet (such as those found here), but to design and implement your own wiring schemes.

The Golden Rule

What a guitar amp actually does is amplify the changing voltage between two contacts enough that it can physically move a speaker. This is what turns the electricity into sound. The two contacts in question are the tip and ring of the jack cable you plug into the input on your amp. We usually call these two contacts “hot” and “ground”. The most basic piece of knowledge you can have about guitar wiring is this:

If the voltage difference between hot and ground is a constant zero,  silence is the result.

Note that this is different to when you plug a cable into your amp, but don’t plug the other end into a guitar (yes, we’ve all done it, even though our amp manual tells us not to). Then, you get noise. So if you plug into your guitar and you get absolute silence, you know you’ve probably got a short circuit.

Wiring a pickup

So now we want to make some noise. This isn’t an article on how pickups work, so for our purposes we will just acknowledge that the strings disturb the pickup’s magnetic field, which is then “read” by the coiled wire. This creates a series of voltage differences between the start and end of that wire, which correspond to the movements of the string, and thus the sound. To start with we’ll use single-coil pickups as they’re more basic. All we have to do is get that voltage difference (from here on in, we’ll call that voltage difference over time the “signal”) into the amp. This is a piece of cake. As you can see in this diagram, we simply attach the two wires from the pickup to the two contacts on the jack. It’s a convention that the black wire goes to the ground contact, and the white one to the hot contact. For this setup, that convention doesn’t matter much. But later in the series we’ll see why it is useful and necessary. Pickup wired straight to jack Having wired this up, we have a playable guitar with one pickup and no controls. For some players, that might even be enough. But I have a feeling you’re not one of those players. And neither am I. Check in again next week and we’ll look at kill switches, volume controls and tone controls.

If you have any questions or comments so far then please bring them up in the comments. I will get back to you as quickly as I can!

Written on June 19, 2012, by Richard Irons

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  • Melbra

    More, I want more!!!!

  • Jireh Abila

    This is Interesting…!!! I like this

  • Did you guys mentioned a Diploma or are you having a laugh?

  • Frederic Bourgoin

    In this situation, would you also connect the ground from the bridge (of a tele in my case) to the ground of the output jack? Thanks!

    • Grant MacNeill

      In almost any situation where the pickups are passive (just coils and magnets, not active, battery powered pickups – EMG for example) then yes, a bridge ground is required. On a Telecaster, it’s usually a wire with one end attached to the back of a pot, or the ground lug on the output jack, run through the wiring channel to the bridge pickup cavity, and the other end is stripped and laid under the bridge plate.

      • Frederic Bourgoin

        Thanks so much Grant! I’m esquier-ing a tele, just a bridge pup straight to the output. If it’s too icy I was going to add a push pull pot for both tone and volume, ideally with a no-load that only applies to the tone? Otherwise I guess I would have to use a blower switch? I want to keep it as minimal as possible, Not too sure how to wire all that, is it complicated? 🙂

        • Grant MacNeill

          If understand your question correctly, you might be confusing push-pull pots with stacked pots. Push-pulls often combine a single pot and a DPDT switch, and stacked pots have two separate pots, and use two knobs with concentric shafts. If you’re thinking of using only one pot, the push-pull might be wired to provide a fixed tone capacitor setting (like one position on a Gretsch tone switch) but the pot would be for either volume or tone, not both. Or, you could use the push/pull switch as the blower switch and the pot for volume or tone – again, not both.

          Early Fender Jazz Bass models used stacked pots to provide volume and tone for each pickup, and that sort of wiring diagram might help you if that’s the layout you are going for. There are nowhere near as many choices for stacked pots as for regular pots, so you aren’t likely to get the no-load tone pot in stacked configuration.

          • Frederic Bourgoin

            Actually I was looking at both, stacked and push pull. But I prefer just having one knob aesthetically. A week ago I literally didn’t know a thing about this so I’m still a noob here, but I found this wiring for a vol/tone push pull, would it work ok?

          • Grant MacNeill

            that would work, within its limits, The limit might be that if you had rolled the volume down, and wanted to also roll back the tone – it’s right back to full volume when you move the switch. When you go back to volume, it’s back to full tone too. There’s no way to store the value of one setting when you switch to the other. As well, you may or may not like the taper on the pot, and you won’t get the no-load effect on the tone from that pot.

          • Frederic Bourgoin

            Thanks! For now I went with bridge pup straight to output, it’s grounded but I’m still getting ground noise. It goes away when I touch the bridge or output, and it’s waaay worse when I remove the ground (from under the bridge to output ground)… 🙁 any help would be super appreciated!

          • Grant MacNeill

            ” It goes away when I touch the bridge” – this result is normal and the way passive pickup systems work. The player is an essential part of the ground. Active pickup systems are about the only way to avoid this. You will also get hum, depending on the orientation of the guitar to the amp and other sources of electrical noise, such as fluorescent lighting. Smartphones on your belt can also induce noise.

          • Frederic Bourgoin

            Thank so much for all your help Grant!