At one time, you’d purchase a guitar cable and when the plugs didn’t fall off or short out, it was an excellent cable, right? Now we now have esoteric guitar cables that cost just as much as some guitars, and claim all types of tonal benefits – but can cables really really make a difference, or is it all just smoke and mirrors? If you are using a guitar or bass fitted with active pickups you can sit down now, because the selection of cable can make hardly any difference, as a result of suprisingly low output impedance of active circuitry. However, if (like the majority) you use conventional passive pickups, then yes, cables do make a difference.
The Cable Conundrum
The electrical resistance of Instrument Cables is insignificantly tiny in contrast to the impedance from the pickups and controls, so that won’t affect your tone a good deal, but cable capacitance is yet another matter altogether. A capacitor is formed whenever two electrical conductors have been in positioned in close proximity, and then for a particular spacing, the greater the surface area of the conductors, the greater the capacitance. The core and screen conductors of typical guitar cable may produce a capacitance of approximately 30 picofarads per foot (or 100 picofarads per metre), so that it follows the longer the cable, the greater capacitance you might have hanging on the output of your guitar.
Placing a capacitor across an audio circuit produces a low?pass filter, and given this, you may expect a lengthy cable (a treadmill with a higher capacitance than usual) to kill your guitar’s high end – which is the argument used by those companies making esoteric guitar cable. However, there’s actually a lot more to obtaining a great guitar sound than simply choosing a low?capacitance cable.
Firstly, before anyone gave cable an additional thought, guitarists were making great?sounding records using standard guitar leads, so if you’re after imitating their sounds, there’s little point in looking for an ultra?low-capacitance cable: that could make your guitar sound brighter than theirs did. In the end, the complete past of guitar sound is built on technological imperfections. Today we could make a guitar pickup having a 20Hz to 20kHz response, we might build perfect amplifiers without audible distortion and that we could connect those to state?of?the?art speaker systems that cover the whole audio spectrum. But we’d hate it! It might be acceptable for quasi?acoustic rhythm playing, however it just ain’t rock & roll!
Another intriguing and important fact about guitar cable capacitance is that it doesn’t only serve as a minimal?pass filter. An electric guitar’s pickups are made of coils of wire, causing them to be highly inductive. Wire a capacitor across an inductor and you get a tuned circuit, rather like a mixing desk’s mid EQ set to improve. In the case of a typical guitar, the tuned circuit is pretty well damped, because of the resistive parts inside the volume and tone circuits and the resistance from the pickup coil itself, however you can certainly still get a 1?2dB hump in the response. If you choose low?capacitance cable, the tuned circuit will resonate in a higher frequency, whereas a very high?capacitance cable will push the pickup resonance downwards. In any event, the tonality of the pickups will alter.
This knowledge can be helpful, since if your instrument lacks sparkle, selecting a low-capacitance cable could improve matters significantly. What’s more, you should check the outcome before spending your qnwpup simply by making up a really short conventional cable (a couple of feet should have the desired effect) to see how your tone changes in comparison with your standard cable. On the contrary, in case your guitar sounds thin and lacking in punch, a regular high?capacitance cable may possibly ensure it is sound better.
An additional consideration, taking all this into account, is definitely the behaviour of radio systems created for guitar. A number of these overlook the cable capacitance issue, or simply put a low?pass filter inside the receiver, but that won’t affect the resonant frequency of the pickups like a real cable does. If you use a radio system and locate that this tone seems thinner, why not try wiring a capacitor of 200?400pf across the jack plug at one end of the short cable that connects the guitar towards the transmitter and find out if that helps?
Summing up then, cables do make a difference with guitars that have passive, magnetic pickups. However, there’s no simple answer as to what type of cable will continue to work best together with your instrument because, just like the amplifier and speaker, the cable is part of your sound. Paul White