DIY | 3.5mm Cables

3.5mm jacks, also called headphone jacks, are the most common type of audio cable. There are different variations of this jack, such as the smaller 2.5mm and the larger ¼”, but they are all functionally similar. 3.5mm cables are commonly available as off-the-shelf items, but sometimes a repair it easier than a replacement. Other times, users need a custom size not available as a standard cable.

This guide will show users how to assemble 3.5mm themselves, either as a repair or brand-new installation. Since 2.5mm and ¼” jacks are the same shape as 3.5mm, they use the same installation process and the below steps can be used as a general guideline for them as well.

Before getting started, it is important to note there are different types of 3.5mm connections. These three types are TS, TRS, and TRRS. TS connections are used for mono audio or independent microphones and have one ring around the metal end of the connector. TRS connections are used for stereo audio and have two rings. TRRS connections are used for stereo plus a microphone and have three rings.

TS (left), TRS (middle), and TRRS (right) are all industry standards.

*Note: In the images below, we will be using a TRS connector as this is the most common type. A video guide featuring all these steps is available at the bottom of the article.

Step 1: Gathering the Supplies

There are a few simple supplies that will be needed for an installation or repair. The key components are the 3.5mm connector as well as the cable. In the image above, you can see the connector separated into two, three, or four different sections depending on the type of connector used. Make sure to use a cable with a matching number of conductors (internal wires).

Aside from the connector and cable, you will also need a wire stripper as well as a soldering iron. A pair of pliers or something similar will be needed towards the end to pinch the connector onto the cable. Something that can hold the connector while the solder is applied, like a soldering station or a simple vice, is also very useful. The connector may come assembled; if that is the case, remove the strain relief (the outer plastic shell) from the metal part of the connector before getting started.

Step 2: Stripping the Jackets

Before actually stripping the jacket, take the strain relief and slide it over the cable. Put the cable stripper over the outside of the cable and spin it around to cut through the outside jacket. Most cable strippers are rated for multiple cables, so check the AWG (American Wire Gauge) written on the outside of the cable to make sure the right notch on the stripper is used.

After the outer jacket is removed, the conductors will also need to be stripped to expose their metal cores. A bit of the shielding may also be sticking out, which can be trimmed away with a pair of regular scissors.

Step 3: Tinning the Cable

Heat up the soldering iron and apply solder to the ends of both conductors and the end of the shielding. This processing is called tinning and will make it easier to establish a secure connection between the cable and the connector in Step 6.

Step 4: Tinning the Connector

Next, use the soldering iron to tin the connection points on the connector. This is much easier if the connection is being held still. Using a vice or having someone else hold the connector both work well, but handle the soldering iron with care if somebody is holding the connector. Each of these solder points corresponds to a different section (the tip, ring, and sleeve for TRS) of the connector.

(Optional) Step 5: Testing with a Multimeter

The tip, ring, and sleeve are the different sections of the connector separated by the plastic ring(s) on the end. If you are unsure which is which, a multimeter can be used for testing. The easiest method is to use the two ends of the multimeter to see which tab on the back of the connector corresponds to the tip, ring, and sleeve respectively.

Step 6: Soldering the Connector

Solder the conductors and ground onto the back of the 3.5mm connector. Make sure to solder each conductor onto the correct section of the connector. If a mistake is made and the solder is still hot, it can be removed with a desoldering iron. Otherwise, the connector cannot be reused and it will need to be cut off to start from scratch.

Step 7: Securing the Connector

Using a pair of pliers or a similar tool, squeeze the back of the connector to secure it to the cable. Then slide up the strain relief from Step 1 and tightly secure it to the connector and your cable will be complete.

Video Guide: