Nine volts DC, center negative, for almost every pedal — but the symbol printed beside the socket and the figure in the manual are the authority, because a supply of the wrong polarity can destroy a pedal in seconds.
The convention
Nine volts DC with the center pin negative and the outer sleeve positive. The symbol showing it is printed next to the socket on nearly every pedal.
Why current draw matters
Digital pedals can ask for several hundred milliamps each. A daisy chain from a small adapter that suits one analog overdrive will not feed four digital pedals, and the symptom is hum, dropouts or a board that behaves differently at rehearsal than at home.
Batteries sidestep it
Most pedals in this class accept a 9 V battery, which removes the polarity question entirely — at the cost of remembering to unplug the input jack, which is what switches many pedals off.
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
Can I use a phone charger?
No. Voltage and polarity are not standardized across chargers, and the plug fitting means nothing. The pedal will not survive the experiment.
How do I power several pedals?
Add the current draw of each one and choose a supply comfortably above the total. A supply run at its limit hums or drops out, and the noise is usually blamed on the pedals.
Last reviewed 2026-08-18