Ultimate guide to guitar effect wiring: how to wire DIY guitar pedals properly?

Your guitar pedal circuit is finally populated and ready to rock! However, you still have to solder all the wires... I noticed that it was during this step that beginners encounter most of the issues that go along with guitar effects making.

Especially with veroboard, you can quickly get a huge mess of wires going everywhere in the enclosure, with the so-called "spaghetti wiring" that we all achieved at least once when starting to make guitar effects!

 

Moreover, the wiring step is often the root-cause of many errors and mistakes that prevent your pedal from properly working, making guitar effects making really frustrating at the beginning. In this post, I want to show you how to make a good wiring, and what you can do to avoid mistakes.

 First of all : always wire in the enclosure! I know a lot of people are saying "rock it before boxing it", but I personally think that wiring directly inside the enclosure helps to make beautiful wiring, because you can adjust the size of the wires more easily.

However, it is a bit more risky (if your pedal does not work, it will be a bit more difficult to repair), and complicated (less space). Try to wire as much as you can outside the box (especially potentiometers).

1. Which wire should I use ?

First, and important question of course! There are two types of cables : solid-core wires, with one copper wire inside the cable (black cable on the picture below), and stranded wires that have many copper wires inside (in red): 

I prefer solid-core wires, because it is possible to twist them to make the overall wiring more aesthetic, or to maintain firmly some elements in the enclosure, which is super useful with veroboard plates to avoid false contacts.

Only use insolated wires to avoid false contacts. Finally, a 0.24mm2 cross section wire is big enough, no need for bigger cables.

2. Potentiometers and switches

Always start with potentiometers. Thus, you can easily fix the PCB / veroboard inside the enclosure. It is very easy with PCB: just solder each lug of a PCB-mount potentiometer inside the holes on the PCB. It should look like this:

PCB wiring is waaaay easier than veroboard, and this is one of the many reasons that make me prefer PCBs to veroboard. Indeed, with a veroboard circuit, you will have to wire each potentiometer, which quickly generate a high amount of wires (4 pots = up to 12 wires!). I will show you the technique I use to avoid a complete cable mess when using veroboard.

We are going to use a piece of cardboard to wire the pots, that uses the same template as the pedal enclosure: drill holes the same way that you drilled your enclosure, and place the potentiometers in mirror order, as if it was inside the enclosure. Here is an example for an overdrive pedal:

Do not forget to reverse everything, especially the legs of the potentiometers. I strongly recommend to write the name of the pots and the number of each potentiometer pin in order not to make mistakes. Then, place the potentiometers in each holes and you should have something like this:

Once you are done, solder a wire longer than needed on each potentiometer leg that you have to connect to the board (Gain 1, Gain 2...etc). I strongly advise you to use solid core wire that will firmly maintain the veroboard above the pots and prevents false contacts that way. Another thing that could be useful to avoid mistakes: use a different color wire for each pot so you do not mix them up!

Double check that they are no mistakes (typically, soldering Gain 3 instead of Gain 1 for instance). Place the veroboard above the pots, and start cutting the wires to the righ length, then solder them to the veroboard. You should have something like this now:

Please check again that all your connections are correct! It is the best way I found to make veroboard wiring that are not completely messy, and avoid quite a lot of mistakes that you can make. Once you are done, unscrew the potentiometers and place the whole circuit inside the enclosure. Lets finish to wire everything now!

3. Power supply wiring

Simple stuff now: the power supply DC jack! Most of the times, it looks like this:

Behind it, there are 3 legs that are used to connect the power supply to your circuit. There is the ground connection, +9V connection, and a +9V battery connection that will disconnect the battery if a power supply jack is connected to the DC jack input.

There are also metallic versions of the DC jack. They look good, but I suggest that you do not use them because they are made for center positive power supply, and the external part of the jack is often connected to the enclosure. Thus, if you use it to wire a negative center power supply (guitar pedals standard), it will create a short circuit!

Here are the different pins of a classical DC jack:

If you use a battery, do not forget to connect the positive wire of the battery snap to the "battery +" of the DC jack, in order not to use the battery when a jack is plugged in.

For the wiring, I suggest that you follow this method, that is closed to the one used for potentiometers:

1. Place everything in the enclosure: screw the potentiometers and PCB/veroboard, screw the DC jack input, audio jack inputs...etc
2. Tin the legs that you are going to connect: fill the holes of each leg with solder.
3. Prepare a wire longer than needed (1 cm/ 0.5 inches more is enough), tin it with a bit of solder (it helps to solder it)
4. Solder it to the leg.
5. Twist it with tweezers like you want (I find that square looks good), then cut it to the right length, and solder it to the PCB/veroboard!

I use the same method for jacks and 3PDT, it is quite easy to make clean connections and an overall clean wiring with this way.

4. Input and output jacks

Another part that is not very difficult to wire. It exists at least 3 different versions of jack inputs: open (good for crowded builds or 1590A enclosures), closed "amphenol-style" that I like a lot, and "amp-style" that are used for PCB-mounted jack builds.

I will show you the connections for each type of jack input.

Open jack
It should look like this:

The metallic central ring is connected to the ground, whereas the small leg and the tab are connected to the tip of the jack that conduct the signal. If you are not sure, you can check it with a multimeter.
These jacks are nice for crowded builds because they do not take that much space, however it is easy to mess it up. Moreover, they are not of very good quality most of the times, except if you go for expensive Neutrik jack.


Amphenol type jack
Here are the connections of this type of jack:

I really like this kind of jack: it is hard to mess it up, and they are though as rock!


Amp-style jack
They look a bit more complicated because there are at least 4 connections for a mono jack... I usually avoid to use this style of jack, because they take a huge amount of space inside the enclosure. However, they are the only type of jack that you can use to mount it on a PCB. Two connections are only used to detect whether there is a jack inserted inside the jack input. It can be useful if you want to disconnect the battery when there is a jack inserted in the input.

Solder the legs that are on the "blade" side, these are the ones connected to the jack:

The ground is conducted by the leg closer to the input, whereas the signal is conducted by the leg that is the farest from de input.

For the wiring, use the same technique presented for the DC jack to connect the ground to the ground of the PCB, and the signal to the 3PDT.

5. The 3PDT switch

If you use true bypass switching, you will probably use a 3PDT switch, which is the "error generation pack" for beginners... Take your time when wiring this little beast!


First, I think it is really important to understand how the 3PDT switch works, read my post about 3PDT and true bypass.

You need to make all these connections:

I suggest that you make the connection on the top left outside the enclosure,it will be easier that way. Then, proceed like the input jacks and DC jacks.
Be really careful in order not to create false contacts between the different legs of the 3PDT, which happens quite often!

6. LED: let there be light

Nearly the end! Last thing to wire: the LED.
This drawing can help a lot in order not to mess with the polarity of the LED:

Always wire a resistor in series with a LED, it should be connected to the +9V pad of the power supply, and to the long leg of the LED. The short leg of the LED is connected to the 3PDT. Here is a schematic:

Usually, a resistance between 1k and 10k is fine, depending on the LED color. Indeed, blue or green LED can be a bit agressive for your eye with a low value resistor. Another solution is to use a 50k trimpot, so the user can set the intensity of the LED himself!

7. It does not work, what can I do?

I like to say that it never works on the first attempt, so if you are in this case, it is perfectly normal! There are many potential mistakes that you can made, fortunately there are many ways to find them.

I suggest that you read these two posts I made that should help you to sort everything out:

• Debuggin guitar effects : most common mistakes and fixes
• The audio probe, the tool that will save your broken pedals!

There it is!

I hope that this post was useful to you, if you have any question, post a comment!
If you liked this post, thank me by liking the Coda Effects Facebook Page!