#1
Hey I have a few questions about power adapters for pedals. I've heard that if you use the wrong one that your pedal can be damaged permanently, or just not work at all, even if the adapter has the same physical input jack. Basically, why i need to know is because I need a specific adapter for my ehx holy grail pedal but I have plenty of 9v power adapters already from various things. I saw at radio shack today that they have different tips for 9v adapters that you can use if you need a different size, which the holy grail needs one that looks like a 1/8" stereo jack. The guy there said to make sure that everything matched or something so I wouldn't damage my pedal. So what exactly do I need to know? my pedal says "9V DC / 500mA" where the power adapter is supposed to be plugged in. so do i need a power adapter that is 500mA and thats it?
#2
You need to check that it's
1) The right current (DC or AC)
2) The right amount of Volts
3) Enough current to power it (a little more or less doesn't usually matter)
4) If you have the right polarity (positive center or negative center)

If all of those are good, then it should work... Did this pedal manufacturer make it into this plug on purpose so that you have to buy thier power supply?

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#3
Indeed.

Electric appliances or in this case your pedal, are wired in relation to the input voltage, if your input voltage changes, every resistor, and capacitor in most circuits would need to be changed or the voltage to each device will be off, in sensitive electric equipment like your pedal, you will either fry it, if you use a much higher voltage, or won't power it (lower voltage).

Just make sure your input is 9 volts with an Milliamp current of 500 such as:

http://bestofferbuy.com/Power-Adapter-9V-DC-500mAh-p-25367.html?currency=USD&utm_source=gbase&utm_medium=cse&utm_campaign=gbase
Last edited by Roy Annashi at Jun 12, 2010,
#4
Everything seems fine except the power adapter I have says "Output: 5VDC 500mA" but the power supply thats designed specifically for the pedal says "Output: 9VDC 500mA". So I'm guessing my power adapter isn't enough to power the pedal since its only 5V?
Last edited by redick4ulous at Jun 12, 2010,
#5
Yeah you won't get much response, you'll need 9V. The output signals how much voltage is leaving to your devices circuit, which in this case 5v isn't enough.


Edit: Forgot to include, I don't know how savvy you are with wiring or anything, but if you have a soldering gun, the jack you need, and an adapter with the right voltage you can always just switch the ends off of one you don't need, unless you need them all, just make sure you make a clean connection.
Last edited by Roy Annashi at Jun 12, 2010,
#6
Quote by julzius
1) The right current (DC or AC)


i thought the point of an AC adapter was to convert AC to DC. i haven't run across any that convert one AC current to another.


Quote by julzius
2) The right amount of Volts

not supplying enough voltage will probably just keep the pedal from turning on or it may perform odd. like my digital reverb pedal wouldn't turn on when not supplied with enough volts, but a pedal like a ds-1 will actually sound 'sagged', there are even some power supplies that allow for 'sagging' a voltage for a desired effect.

Quote by julzius
3) Enough current to power it (a little more or less doesn't usually matter)

the current you are concerned about is in units called 'ma'. basically your adapter must meet or exceed your device's current draw demands. if a pedal cannot provide enough current then it turn on or it'll turn on then cut back off shortly after(depending on design).

Quote by julzius
4) If you have the right polarity (positive center or negative center)

this is the sign that looks like:


this can jack some stuff up and break pedals, make sure you match polarity.

read this
http://support.radioshack.com/support_tutorials/batteries/pwrgde-6.htm
punk isn't dead, it's always smelled that way.

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Last edited by gumbilicious at Jun 12, 2010,
#7
and of course I have a 12V 500mA power supply, but not a 9V. The 12V would probably be too much right?
#8
I just read that link. Very helpful, thanks. So I need to match the voltage exactly, but the current can be higher. So if I have a 9V with positive polarity that is higher than 500mA it would still work?
#9
Quote by redick4ulous
I just read that link. Very helpful, thanks. So I need to match the voltage exactly, but the current can be higher. So if I have a 9V with positive polarity that is higher than 500mA it would still work?


very very good. yes, that is dead on.

edit: also take into consideration the actual tip. most manufacturers use a boss psa-120 style tip to make it easy, but there are some pedals with weird stuff (i am talking about you ehx)
punk isn't dead, it's always smelled that way.

"A perfection of means, and confusion of aims, seems to be our main problem."
-ae
Last edited by gumbilicious at Jun 12, 2010,
#10
Ok, now I have another question. I already have a power supply for my pedal, but my pedal isn't working. I'm not sure if its the pedal itself or the power supply, thats why i'm asking about other power supplies. I actually have an adapter that would fit my pedal, but the adapter only fits on a power supply that is 12V 500mA. All I really want to know is if its my power supply or the pedal itself. Is plugging it in with this power supply and adapter a bad idea? all I would be doing is seeing if the light would come on. But I'm kind of afraid because it might damage the pedal

edit: and yes, mine is ehx. its that 1/8" input jack
#11
Quote by gumbilicious
i thought the point of an AC adapter was to convert AC to DC. i haven't run across any that convert one AC current to another.

Adapter probably isnt the best name, but its the easiest to understand. Transformer is probably a better term, but then people big think big chunks of iron
#12
There are plenty of AC adapters that convert AC to AC. A lot of valve pedals do so they can step it up to a decent voltage easily and have a low voltage on the plug. Alesis gear is 9 VAC too.
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#13
Quote by littlephil
Adapter probably isnt the best name, but its the easiest to understand. Transformer is probably a better term, but then people big think big chunks of iron


that is pretty much what i was thinking, the concepts are similar, but rectification of the AC signal is usually implied with an ac adapter.
punk isn't dead, it's always smelled that way.

"A perfection of means, and confusion of aims, seems to be our main problem."
-ae
#14
Quote by Cathbard
There are plenty of AC adapters that convert AC to AC. A lot of valve pedals do so they can step it up to a decent voltage easily and have a low voltage on the plug. Alesis gear is 9 VAC too.


no kidding then. wonder i haven't run into them yet. well, i guess i am on the map then
punk isn't dead, it's always smelled that way.

"A perfection of means, and confusion of aims, seems to be our main problem."
-ae
#15
From how I've been educated by the guys at Voodoo Lab and a few other pedal manufacturers, is that any pedal that requires a 1/8th jack, will always be a positive tip or reverse polarity. In other words opposite of the 2.1mm barrel type power plugs or negative center.