Power Supply Amperage Limits

[Bio77]

I just bought a Voodoo Lab PP2 on CL. I wanted to verify that I understand the current draw limits correctly with a few questions:

1. If a pedal needs 400mA and the max output of the supply is 250mA, does the pedal just not work? If it does work, is there any danger to the pedal or will only the power supply be overworked and potentially fail?

2. Seems like pedal manuals overstate the current requirements for their pedals when compared to direct measurement. Is this them covering their ass or is it analogous to capacitor voltage ratings and you want to have approximately double the capacity at the supply?

 

[Nostradoomus]

It won’t damage them. Digital pedals just won’t work, analog pedals will exhibit odd behaviour (or in the case of fuzzes, behaviour you may enjoy )

The power supply should have a fuse you can replace if anything goes awry.

 

[pricklyrobot]

Amperage ratings tell you how many Amps something can safely produce or conduct. They’re there to protect wire and other components from overheating/burning up.

A load (pedal, anything else that uses power) won’t ever pull more than it’s stated amperage or wattage.

If a power supply is rated for 1A and you attach a 2A load to it (in the absence of a fuse) it will pull that 2A, and everything in the power supply will heat up (more that it’s supposed to). This may just shorten the lifespan of your power supply, or it may lead to a more acute and/or catastrophic failure.

You can run a pedal on a lower Voltage than it’s designed for and it might do something cool, or just not turn on, but you won’t hurt it.

If you connect a pedal to a higher Voltage than it’s designed for, you’ll damage the pedal, but the power supply will be fine.

If you connect a pedal that exceeds the Amperage of your power supply, you’ll damage your power supply (or just blow a fuse if you’re lucky), but your pedal should be fine. But It’s also a potential fire hazard, so don’t do it!

 

[Aentons]

It has auto shutdown short protection on each output but I'm not sure of the threshold that constitutes a short. Sometimes those higher current requirements for digital stuff are just startup spikes and sometimes it's just for one component, like the screen which will glitch but everything else works fine. It just depends on the pedal.

They do have voltage and current doubling cables available if needed.