Three to six meters is the practical range for an unbalanced instrument cable. Beyond that it picks up more interference and loses high end, and the fix is a balanced connection or an active box rather than a longer lead.
What you lose
Top end first, then signal level, then noise immunity. On a long cheap lead a guitar sounds duller and hums more, and both are blamed on the guitar.
Buy the length you need plus one meter
Spare length coiled behind an amplifier is an aerial, and it is the most common avoidable source of hum in a home setup.
When you genuinely need distance
A DI box on stage, or a balanced line from an interface. Both solve it properly where a longer instrument cable only makes it worse.
Check your own manual before you plug anything in. Voltage, polarity and current draw differ from model to model, and the manufacturer’s figures take precedence over anything written here. A supply of the wrong polarity can damage a pedal in seconds, phantom power is safe for most microphones but not for every one, and the required voltage is printed next to the socket or stated in the manual — not inferred from a connector that happens to fit.
The questions players ask
Why does length matter more here than on a microphone cable?
A microphone cable is balanced and rejects interference. An instrument cable is unbalanced, so everything it picks up arrives at the amplifier.
Does a thicker cable help?
Capacitance matters more than thickness. Cables sold for instruments state low capacitance for exactly this reason; a cheap speaker cable used as an instrument lead does not.
Last reviewed 2026-08-18