A longer guitar cable does not just reach farther. It also changes the tone, and the effect is easier to hear with passive pickups than most people expect. Here is why that happens, how long is too long, and what to do if you need a long run.
Why length changes the sound
Every cable has capacitance, a small electrical property that grows with length. A passive guitar pickup is a high-impedance source, and together the pickup and the cable form a low-pass filter. The more capacitance the cable adds, the lower the frequency at which treble starts to roll off, and the resonant peak of the pickup shifts down too. The result is a duller, less sparkly sound.
Capacitance is usually listed in picofarads per foot (pF/ft). Instrument cables often fall somewhere between about 15 and 40 pF/ft, so a 20-foot cable can add several hundred picofarads to the signal path.
How long is too long?
There is no sharp cutoff, and it depends on your pickups and your cable. As a rough guide:
| Length | What to expect |
|---|---|
| Up to about 10 feet (3 m) | Little audible change for most players. Fine for practice and rehearsal. |
| 10 to 20 feet (3 to 6 m) | The standard stage range. Some treble loss is possible with passive pickups, especially with a high-capacitance cable. |
| Beyond about 25 feet (7.5 m) | Treble loss becomes easy to hear with passive pickups. Hum pickup also increases. |
These are guidelines, not rules. Some players like the slightly darker sound a long cable gives, and some tube amps are bright enough that it sounds fine. Trust your ears.
Hum gets worse too
A guitar cable is unbalanced, so it cannot cancel noise (see balanced vs unbalanced audio). A longer cable has more length to pick up interference from lights, screens and power wiring. If you hear more hum on a long run, that is part of the reason.
What to do if you need a long run
- Choose a low-capacitance cable. Check the spec sheet for pF/ft. Lower is better for passive pickups. See what makes a good guitar cable.
- Add a buffer. A buffer pedal, or a pedal with buffered bypass, converts the guitar’s high-impedance signal to a low-impedance one at the start of the chain. Long cables after the buffer cause far less treble loss.
- Consider a wireless system. Wireless systems have a built-in buffer and remove the cable run entirely.
- Keep the cable between the guitar and the first pedal short. That stretch is where capacitance matters most, because it carries the signal before any buffer.
- Use active pickups if they suit you. Active pickups have a low-impedance output and are much less sensitive to cable length.
The pedalboard effect
Pedals with true bypass add the length of their patch cables, and any internal wiring, to the signal path when switched off. A long chain of true-bypass pedals can behave like a very long cable. Short patch cables help (see pedalboard patch cables), and so does a buffer.