power supply question

My OD pedal needs to be powered using a 9v power supply due an accident including my guitarist friend that borrowed it for a gig. The back of the pedal says 9v DC 100Ma. I found a power supply for some random appliance laying around and it says 9v DC 500Ma on it.

I tried it on the pedal and it worked for the 2 minutes that I played with it, but is this safe for long term use????

I plan to get a one-spot eventually so that I can just power all of my pedals and not have to worry about batteries, but that may be a while.

Try Amazon or ebay for a One Spot. Save a bit from non retailers....

too much amperes shouldn't be an issue at all. If you're running it higher than 9v, then you have a high risk of damaging the pedal. The power supply should be fine. It would be nifty to have in case you ever get a pedal with a high power demand.

My reverb pedal has worked fine for a long time now with 100 but I tried saving some presets in it, as per it's built in capability, but it kept shutting off and erasing all it's presets when I tried. I switched it to the higher output slots on my pp2 and it works great now.

Don't know why that was relevant to you at all.... but you should be fine =P lol

Haha alrighty. Cool beans! I have an OD pedal for church now!:D. And it looks like I have a bunch of those things laying around, but a single daisy chain would be better in the long run:P

Thanks guys/gals:)

Edit: Looks like my tuner pedal has an output for a max of 200ma, so a daisy chain off of it should work for the OD and my muff! Dont need a one spot any more:)

I'd measure the output voltage of that supply. A non regulated supply would be a lot higher than 9.5v. They're specked out at rated voltage at rated current so if your running at less than 500ma the voltage would be a lot higher. A regulated supply would not have this problem.

I'd measure the output voltage of that supply. A non regulated supply would be a lot higher than 9.5v. They're specked out at rated voltage at rated current so if your running at less than 500ma the voltage would be a lot higher. A regulated supply would not have this problem.
This is exactly what you should do!

I'd measure the output voltage of that supply. A non regulated supply would be a lot higher than 9.5v. They're specked out at rated voltage at rated current so if your running at less than 500ma the voltage would be a lot higher. A regulated supply would not have this problem.

It says "output: 9v 500ma" on the back of the supply. The power supply was for a guitar amp that could either run off of 4 AA batteries or this plug.

Many OD pedals can run safely at a (reasonable) higher voltage. Many digital pedals can be damaged by higher than rated voltages. Also, most random wall warts are not very well regulated which makes them noisy for pedal use. A 1 Spot is $20, well regulated, and can daisy chain a lot of pedals - no need to mess around.

In this case,appararently there was enough filtering,as Thinlineman reports that "it worked for the two minutes I played with it."Since it was a power supply for a guitar amp,it figures.If you pick up a wall wart for an office machine or calculator,the filtering is often too small and you will get an ugly hum from the pedal.

So if there's no hum I'm good to go??

The muff (before the OD in my chain) that is running off a 9 volt battery hums, but that's just the nature of that pedal:P.

It would be easy for me to say :Yes ,nothing would probably happen.
If it were my pedal I would take a voltage reading before I plugged it in.
Hum would be bothersome but wouldn´t hurt the pedal.
A too big voltage could.It is not my pedal to take chances with.

I have two one spots, one is 800ma, and the other, I don't remember..
500ma should be fine, but most pedals don't really pull much power.

I tested my board with a meter and it used 180ma when everything was on.
I'm running a Dunlop wah, DynaComp, Tubeulartor, DS-1, TS9-DX, Phase 90, CH-1, DD3, Morley Volume pedal... I think that is all of them...

Try Amazon or ebay for a One Spot. Save a bit from non retailers....

Here's a tip... buy only the daisy chain extension for the One Spot, then go into your local Goodwill or Salvation Army store. If they're anything like the ones in Seattle, they will have a bin or shelf with loads of 9v power adapters (other voltages as well, but 9v is what you're after). Find one with a current rating of 1A (1000mA) or higher that has the same type of plug used by the OneSpot (and most pedals out there). They'll generally be 99 cents and will work just as well as the OneSpot power adapter. Watch that the polarity is correct (negative center, positive sleeve), or you can just cut the plug off and rewire it for the correct polarity. Solder + heatshrink and it'll hold for ages.

The current rating on the power supply is the sustained maximum current that the power supply can handle over the load (pedal).

A 9VDC 500mA power Supply can source up to 500mA of sustained current. Any more than that, and the power supply will begin to break down.

The danger here is not the pedal, but the power supply. Using a device (or devices) that draws more than the rated current from the power supply can cause the power supply to burn out, or worse, start a fire.

Edit: Power supplies are typical designed with a headroom built in for in-rush surges and spikes so they can handle a higher load than rated, but only for a short period of time.

You are perfectly right Montana when you say that a 500ma supply can´t deliver more than that current for a sustained period without breaking down.In this particular case though,there is no danger to the supply since the OD pedal only has a current draw of 100 mA.What is surprising to me is that there are eleven posts from members who are trying to help Thinlineggman out and one thing he is asked to do which would help him.MEASURE THE VOLTAGE OF THE SUPPLY!(I apologize for shouting.)There must be someone you know or somewhere you can go where there is a multimeter,Thinlineggman.It takes two seconds to measure it! Bye!

You are perfectly right Montana when you say that a 500ma supply can´t deliver more than that current for a sustained period without breaking down.In this particular case though,there is no danger to the supply since the OD pedal only has a current draw of 100 mA.What is surprising to me is that there are eleven posts from members who are trying to help Thinlineggman out and one thing he is asked to do which would help him.MEASURE THE VOLTAGE OF THE SUPPLY!(I apologize for shouting.)There must be someone you know or somewhere you can go where there is a multimeter,Thinlineggman.It takes two seconds to measure it! Bye!

I have been running around a lot lately and just started at a new job that has me working from early in the morning to mid afternoon, so I haven't even though about playing my guitars haha. I played bass for a gig today, but that's it.

And I do know someone with a multimeter. I just haven't had the time to ask, or to pick it up and actually do the measuring. By Wednesday I will have it measured, though, so that I can use the pedal at practice.

I suppose measuring the DC voltage could provide some reassurance that it is correctly labeled 9V, but to be honest, I have a bunch of DC supplies that I use for guitar effects and other electronics and I have not bothered to measure a single one. I guess what I'm saying is that I am willing to trust the label on the supply. Is there a chance it could be incorrectly labeled? Sure. Has it ever happened to me? No.

It is not a question of a "false label"!Read the thread.I´ve got unregulated 9 volt supplies that will give your average Pedal 13 volt because they are made for devices that draw more power!

It depends what the power supply actually is. If it's nothing but a 60hz transformer, diodes and a cap, then it will vary with load and movements of the line input voltage.

If it is a regulated switching power supply, then it will regulate to the correct voltage within it's current range.

Easy way to tell......take the power supply and plug it in. Now lie it on top of your guitar pickups. Plug in the amp and turn it on. If you hear white noise "shhhhhhh", it's a switcher for sure.