The ideal minimum it would need to operate is 8V, but realistically 7 or even 6V would possibly work if it could get the current it wants. All operating voltage is delivered through converters and regulators, so the input voltage isn't really that important. Again on the pedal side, this is not a big deal. So where you think you're delivering 9V you may only be seeing 7 or 8. So if I have a circuit that wants 500mA at 9V and you supply it with 450mA, nothing is going to break, but the supply voltage will sag under the load. What exactly happens depends on the power supply and how much current it's getting. Click to expand.From the pedal's standpoint if you can't provide enough current then it just won't work right.
