How to properly choose your jack cables?

The cable is an important element that is often ignored, but that can be responsible for high frequency losses and noise. Let’s see together how to choose correctly your jack cables, the characteristics to look at, and how it will affect the signal.

why is it necessary to choose quality jack cables?

the jack cable: a low pass filter

a bit of theory

Jack cables are composed of 2 conductors separated by an isolating sheath: they consequently have all the properties of a capacitor! This is the capacitance of the cable. For a good cable, it is under 80pF per meter of cable, and a serious cable manufacturer usually gives its value.

When we plug a cable into a guitar, the output impedance of the guitar coupled with the capacitance of the cable will form a low pass filter. This filter will have the effect of attenuating the high frequencies of our signal.

The output impedance of a guitar is usually a dozen kOhms. In reality, this value varies according to the frequency, because a guitar pickup is not simply a resistor, but an RLC circuit. The impedance can go up to 100kOhms for some frequencies, and the pickup manufacturers often give an average of this impedance.

And the problem is this high impedance. For example, for a 6m cable with a 80pF/m capacitance, connected to a guitar with an average impedance of 25kOhms, this filter will attenuate everything after 13kHz. This is clearly in the audible frequency range! And the longer the cable is, the lower the cutoff frequency of the filter will be.

That’s why it’s important to choose a cable with the lowest possible capacitance for a guitar cable. Be careful, some manufacturers give values in pF/dm, or pF/ft, which can make you think of lower values.

For our guitar cables, we use the Sommercable Spirit LLX, which has one of the best capacitance of the market!

coaxial cable

A guitar cable must also be coaxial. This means that the conductor connected to the ground forms a shield around the wire that transmits our signal.

This ground shield acts like a Faraday cage. Its purpose is to isolate our signal from all external electromagnetic interferences (especially the 50 cycles of the mains, the electromagnetic waves…). It is thus an essential element to avoid all noise problems.

A coaxial cable is particularly important because the signal coming from the guitar catches noise much more easily, due to its high impedance and extremely low amplitude.

This is why all instrument cables are coaxial, but a speaker cable is often not. The signal driving the speaker is strong enough to make external perturbations completely negligible.

A speaker cable must also have a sufficient diameter to transmit all this power correctly. Which is not necessarily the case with instrument cables. It is therefore important to not mix instrument cable and speaker cable.

connectors

The connector will also generate losses. When you plug a jack in, it creates a contact surface between the connector of the jack and the connector of the guitar or the pedal. This contact surface also creates a parasitic capacitance. Over time, the connector can oxidize, increasing this capacitance.

So we use gold-plated connectors, which have the advantage of not oxidizing, and thus keep the same characteristics over time.

pedalboard patches

On a pedalboard, this parasitic capacitance at the contact surface between the jack and the pedal will increase with each connection.

The signal that will pass through the true bypass of a pedal will pass through very thin wires, several soldering points, a switch that will make contacts between several conductors… All these elements will generate losses, even more important than the losses of a single cable.
So if we have true bypass pedals switched off just after the guitar, each of these pedals will interact with the high impedance of the guitar, and attenuate the treble even more. When combined, these pedals have the same effect as extending our cable several dozen meters!

There are also solderless patches, which you can assemble yourself. But the contact between the cable and the connector, which is not covered with tin, can also oxidize over time, resulting in further loss of high frequencies. And the robustness of a solderless contact is not very good.

That’s why our DIY cables are soldered. We want to offer the best quality possible for a pedalboard that lasts in time!

the solution: the buffer

The solution to avoid these losses is to put a buffer just before the pedals. A buffer is a pedal with the single purpose of having a low output impedance. The low-pass filter formed between the low impedance of the buffer and the capacitance of all the cables and pedals that are connected after it, will have a much higher cut-off frequency, far beyond the audible frequencies!

The ultimate solution would be to have the buffer integrated in the guitar. And that’s how the first guitars with active pickups were born!

A good buffer is completely transparent. However, some vintage effects like the Fuzz Face were designed to work with the high impedance of a guitar, when buffers did not exist yet. Putting a buffer before a Fuzz Face can make it sound different.

our range of jack cables

We have therefore developed a complete range of jacks, considering these parameters to offer the best performance!

Every cable has its own application, whether it’s for connecting the guitar, wiring a pedalboard or connecting a cabinet to an amp.

premium guitar jacks

For the guitar cables, we chose the cable with the lowest possible capacitance, because it is the one that will interact with the high impedance of the guitar. So we use Sommercable Spirit LLX with only 52pF/m, and ultra resistant Hicon premium connectors, for an indestructible cable!

pancake patches

The pancake patches use ultra-flat connectors, which save space between the pedals. The connectors are gold plated and there is a wide range of lengths available to suit all situations, using the shortest cables possible and having a perfectly organized pedalboard.

bay patches

These patches use thinner connectors than the pancake. For situations where the connectors are too close together, like on a switcher. Always with the same variety of lengths.

stereo patches

Our pancake patches and bay patches are also available in a stereo format. For expression pedals or pedals with TRS stereo outputs.

speaker cables

These particular jacks are designed with a special cable made to support the high currents that the amp sends to the cabinet. Indeed, a classic instrument cable is not designed for this application, and could generate losses, or even damage the amp.

need another cable?

We propose all the spare parts of our cables individually, to assemble your own jacks, to make a custom cable… We even have other connectors to make RCA, XLR and 3.5mm jack cables! And of course, we have written articles on how to solder each connector correctly.