9V Power Supplies

Which supply?

• Guitar Man GMP02: 9V DC, 600mA, centre negative.
• Rocktron DC OnTap: 9V DC at 1670mA with daisy-chain leads for up to 20 pedals.
• Variable 3-12V supply (P003C): selectable voltage and polarity with interchangeable tips.
• Ernie Ball Volt: four isolated 9V DC outputs at up to 300mA each, plus an 18V DC thru.

How to choose a 9V power supply

• Voltage: 9V DC suits most effects pedals. Check the rating of any pedal that needs 12V, 18V or AC power before you plug it in.
• Polarity: most 9V pedals are centre negative; it is usually printed by the power socket.
• Current: add up the current draw (in mA) of everything on the supply and keep it within the supply's rating.
• Plug: standard pedals take a 2.1mm plug; older pedals can need a 2.5mm plug or reverse polarity.

Match voltage, polarity and plug size to the device's own rating, and keep the total current within the supply's limit.

9V power supply FAQ

What is a 9V power supply?

A mains adaptor that gives 9V DC, the usual supply for guitar effects pedals and many small devices, in place of a 9V battery.

Which polarity do I need?

Most 9V pedals take centre-negative power, and it is usually printed by the power socket. The Guitar Man GMP02 is centre negative, and the P003C lets you select the polarity.

How many pedals can one supply run?

As many as its current rating allows. Add up each pedal's current draw (in mA, usually listed in its manual) and keep the total within the supply's limit: 600mA for the Guitar Man GMP02, or 1670mA shared across up to 20 pedals for the Rocktron DC OnTap.

What is an isolated power supply?

One where each output is electrically separate from the others, which helps avoid ground-loop noise between pedals. Ernie Ball states that every output on the Volt is isolated from the input and from all other outputs.

Can I use a 9V power supply for something other than a pedal?

Yes, if the device takes the same voltage, polarity and plug and draws no more current than the supply gives. The P003C covers 3 to 12V DC at up to 1000mA, with eight interchangeable plugs.

Where can I buy a 9V power supply in the UK?

Order here, with next day delivery available, or collect from our shop at 60 Weir Road, London SW19 8UG.

Related

Pedal power supplies, 9V batteries and all power.