What happens if...

[MrBump]

... you plug a 9v pedal into a 12v adapter?

Does it go boom, or blow out a bit of the circuit?  Or can most tolerate the extra power?


Mark.

[tomjackson]

I'd say it depends on the pedal, some have protection circuitry, some don't.  Some pedals can run from 9V to 18V happily and are designed to accept greater voltages.

I think most would be okay but some would die :(

[gingataff]

I'm hardly an expert but I think it'll mostly depend on the value of the electrolytic caps used. Most small ones are rated up to 16v so you *should* be fine with 12v, but be wary of 18v power supplies unless you know what's inside the box.
Often using a higher voltage supply can give more headroom, but if in doubt use 9v.

[jpfamps]

The advice given above is correct for most pedals as the components should be able to tolerate the higher voltage.

I would be wary of using a higher voltage adaptor in a digital pedal (although there wouldn't be much point).