Quick question about current draw

[smooth55]

I have a pedal that requires an AC adapter with 300mA current draw. I know from another thread that having an adapter with more than that will not fry the pedal, it'll only draw what it needs. What about an adapter with less than 300? How will that affect the sound of the pedal?
Many thanks,

[SonicProvocateur]

The pedal will not function properly, if not at all. It may make glitching noises or dying noises. It will be very apparent that it is not being supplied with the correct voltage/current. I myself use a Visual Sound 1 SPOT converter. It handles up to 1700ma and I have 2 daisy chainers on it and it never fails me in the studio or live!

Now in the case that it is not a 9V pedal (some digitech pedals are 18V and 12V and require their own special adapters) they MUST be ordered from digitech/roland etc, and a generic power supply will not do.

[smooth55]

Interesting. I've used just generic supplies for my pedals without paying much attention to the voltage/current - only worried about the polarity. I'll have to take a look at my pedals specs and see how many of them I've been using an inadequate adapter for. I have several 200mA adapters but I know a few of my pedals are 300mA. I was looking at the pedal power 2 from Voodoo labs and noticed that most of it's outlets are 100mA or 250mA. I guess maybe I should look elsewhere for some kind of pedal power supply like that...

[smooth55]

Just found this quote from the Pedal Power 2 manual:
"Doesn’t my pedal need a 200mA power supply?
Not if it runs on a standard 9V battery. The adapter available
from the pedal’s manufacturer may be able to supply
up to 200 or 300mA, but pedal effects which will run on a
battery will not draw more than about 65mA."
That seems strange to me. I have no idea how the electronics work, although up to this point, I've never had a pedal break on me when not paying attention to anything other than voltage and polarity. Maybe I've just been lucky, maybe not.

[SonicProvocateur]

You are correct to a point. Like the other day, my buddy accidentally plugged up a Electro-Harmonix #1 Echo with a 12V adapter instead of the 9V and it just made crazy "BLOOP BLOOP BLOOP" noises until I figured out he had the adapters wrong. Didn't hurt the pedal, but it made obvious noises from overpowering the circuits. If you were to plug up a 18V Dunlop wah with a 9V adapter (which ive done) it just sounds like garbage from underpowering.

Like you mentioned, always watch for the polarity, and match the voltage. Also be sure its DC or AC (although most small pedals are DC, some are AC). Its also hard to mix up the Digitech adapters, they are slightly larger tipped than the standard Boss/MXR/Dano/etc etc adapters.

[smooth55]

Yeah, I know there are problems if you don't have the voltage and polarity but I was curious about what the mA means and how it would affect the pedal operation when the adapter is rated less than what the pedal calls for.

[S-man]

It is the amperage and you will run the risk of burning up the power supply having a lower amperage rating. Also, you run the risk of damaging the pedal.

In a typical circuit the thickness of the wire/conductor determines it's ampacity.

[smooth55]

I see. So, what do you make of the claims by Voodoo Labs that pedals which use a 9v battery only actually draw about 65mA?
I don't mean to be anal, but I'm looking at buying a power supply for my pedals and I want to be sure that I won't burn out either the supply or the pedal with mismatched amperage.

[S-man]

With amperage...you are better off having a higher mA rating on the power supply.

Also, if you are using it to power multiple pedals, you need to add the amperage of all of the pedals combined and they need to operate at the same voltage.

Higher amperage is OK...lower is not.

This only applies to amperage NOT voltage.

[smooth55]

I understand the voltage side of things. Basically you're saying that something like the Pedal Power 2+ is not adequate if I want to power my pedals because some require as much as 300mA and the PP is only 100mA (despite their FAQ stating that if a pedal can run off a normal 9v battery, it won't pull more than 65mA).

[S-man]

Yeah...go off of what is printed on the pedal from the manufacturer.

Most have the power requirements labeled on the equipment.

[LonePhantom]

If you want a fairly cheap option for a power supply to power multiple pedals check out www.effectspowersupplies.com.

I've got their 6 daisy chain 1.3A power supply. It's great, although I'm wishing now that I got the next step up as my Digitech Hardwire pedal doesn't like to share with too many other pedals and it makes some noise.

I've reviewed their stuff on the Comparison Shopping reviews, and on my blog.

[smooth55]

I'd be interested in hearing if you figured out the reason it doesn't like your DL-8. I've pretty much settled on that pedal for my delays and am looking at something like the one spot, just because it's so cheap in comparison to the PP2+ or the DC brick from Dunlop.

[LonePhantom]

I believe that because the DL-8 requires more mA than my Boss pedals that I should have got the power next step up in the daisy chained power supplies. Apparently it's always good to have excess mA available in your power supply for the cleanest signal. I haven't got enough with it hooked up, along with the others. Probably something to do with peak power, as opposed to average power.

Nothing wrong with the DL-8 of course, it's just a power-hungry pedal due to it's powerful design. Subsequently it chews through batteries. I'm just going to buy a separate power supply for it now, the rest of my 9V pedals will run on the daisy chained one I got from effectspowersupplies.com.