Whether your bass is a single-coil or humbucker, the basic wiring remains the same. Here is a typical four-knob jazz bass configuration with each volume pot controlling one pickup, and the tone control blending them together.
Tip – use shielded cloth wire on longer connections to reduce unwanted electrical noise. Always tin the lugs of any pots or jack socket that require a solder connection.
Pickups
The pickups in a bass guitar are the main sources of sound and there are many different configurations available to suit your personal style. These range from single-coils to humbuckers and can be wired in various ways to alter their function, such as by changing the balance between their outputs and creating a coil tap for single-coil operation. You can use the diagrams below to help you determine how to wire your pickups and choose a wiring layout that suits you.
The first thing to do when rewiring your bass is to connect the two volume controls to the signal wire from the jack socket. This is done by creating a hook at the end of the wire and feeding it through the tip (signal) lug of each pot. We recommend using shielded wire for this, as this will reduce unwanted electrical noise and will also make the connections more durable. If you do not have any shielded cable, standard non-shielded black and white wire will do just fine.
Next, the bridge and neck pickups need to be connected to their respective volume pots. Generally, the middle terminal of each volume pot will be connected to the bridge or neck pickup depending on your desired setup. The rest of the wiring is up to you – try connecting one pickup to each pot, or both in series for a fuller and more powerful sound.
Another cool way to change your pickups’ function is to add a toggle switch that can be used to select between a traditional parallel or series wiring for your bass. This can be especially useful if you have a humbucker, as it can give you the option of running your humbuckers in series for a more powerful and focused sound or in parallel to get a warmer tone with more mid-range.
We recommend tinning the lugs of all the pots and jack socket terminals that will require a solder connection prior to adding your wires. This will ensure a strong mechanical and electrical connection by helping the solder flow into the joint more effectively.
Switches
When it comes to wiring a bass guitar, switches play an important role. They can be used to change the way the tone control responds and add some additional features to your instrument. Switches are also easy to install and are a great place to start for those who want to make some basic electrical modifications to their guitar.
Before installing a switch, it’s important to understand how it works and how it interacts with the other components of your instrument. There are many different types of switches available, each with its own unique function. Some common types of switches include push/pull, toggle and rocker. Once you have a good understanding of how each type works, you can begin to experiment with them and find the best fit for your bass.
Toggle switches are a common upgrade for electric basses because they can increase the amount of control you have over your tone. They can be used to isolate the neck and bridge pickups or to create a series/parallel setup. When in parallel, both pickups will share the same signal and can be pushed together to produce a fuller sound. Alternatively, you can use the switch to solo the bridge or neck pickup, giving you more control over your tone.
Once you have decided on the type of switch you want to use, it’s important to prepare the jack socket and pots for installation. First, remove any existing wires from the jack and pots. Next, clean the jack socket and pots with rubbing alcohol and a cotton swab to remove any dirt or debris. It’s also a good idea to install a new ground wire from the jack socket to the chassis or metal casing of the switch. This will prevent noise and buzzing from a poor connection.
Finally, it’s a good idea to spend a few minutes tinning the jack and pot terminals that will need a solder connection. This will ensure a quality mechanical and electrical connection once you’re ready to solder. I recommend using teflon hookup wire on all of your connections as normal plastic hookup wire tends to melt or even burn when exposed to high levels of current.
Pots
Many bass guitars have two pickups (which means they have two audio signals) and these are controlled by one or more volume potentiometers. On many instruments like the Jazz Bass or a Gibson Les Paul, there are independent volume controls for each pickup which are wired with a selector switch in such a way that when the knob for the neck or bridge is turned down, only the relevant signal is reduced, not both signals. This is different from a blend pot, which allows you to mix the two signals into one by moving the control to the left position.
The first thing to do is to cut the ground and pickup wires from your old harness, stripping off the insulation leaving about 6mm (1/4″) of bare wire on each end. Then, using your pliers, bend the end of each wire back on itself so that it makes contact with the solder lugs. This creates a hook which helps to make a good electrical connection and also helps to prevent the wire from getting loose in the future. Once this is done, solder the wires to the lugs of each pot.
Next, add a tone capacitor – for a bass I would recommend a 0.047uF cap. One lead goes to the input lug of the first volume pot, and the other to the input lug of the second. Remember that pots are non-polarised so it doesn’t matter which way round the capacitor is placed. It is also a good idea to bend the lead back on itself again (like with the wires) to help with the mechanical integrity of the connection.
With the caps and volume pots in place, you can now move on to the blend control. Depending on your personal preference, you may want to use an audio taper pot rather than a linear taper pot – the former changes resistance more evenly and therefore sounds more natural. With the control set to its middle position (all the way clockwise) you will hear the two signals mixed together, but at lower positions the higher frequencies will be throttled and the overall tone will darken.
Amps
There are many different kinds of bass amplifiers. Some are designed to drive active pickups, while others are intended for use with passive piezo transducers found on acoustic basses. In either case, they must be able to handle high input impedance loads without distorting.
Most modern amps have a speaker output jack labeled “speaker out” or something similar. There is usually information about the minimum load the amp can safely accept marked somewhere on or near this jack. It is important to heed this information, since connecting an improper load can damage the amplifier.
When connecting a speakers to an amplifier, it is generally best to use parallel wiring. This method connects the positive output terminal of the amp to the positive terminals of each speaker. This results in a total load of 8 ohms. In contrast, series wiring connects the negative output terminal of the amp to the negative terminal of each speaker. This results in a load of 16 ohms.
In either case, the speaker wires should be run to a 1/4″ jack on the back of the amp. This jack is typically labeled “speaker out” and also usually has a ‘B&T’ (balanced send) terminal that can be used to feed a mixer or recording console.
For longer wiring runs, it is a good idea to use shielded cable. This reduces unwanted electrical noise that may be picked up by the wire itself. Standard non-shielded wire can be used for shorter connections between components, such as between a volume pot and its middle lug.
The final step in a typical bass guitar wiring is to solder the connections. It is important to use a quality soldering iron, and to ensure that the connection points are properly cleaned and tinned before applying solder. This process helps to create a stronger, more reliable connection. It is also a good idea to use heat shrink tubing on all of the exposed connections, to further protect them from corrosion. Finally, it is a good idea to test the circuit before reassembling and plugging it into an amplifier.