Author Topic: How do I put jacks for 9V adaptors on my pedals?  (Read 23626 times)

VolksWilliam

How do I put jacks for 9V adaptors on my pedals?
« on: March 14, 2013, 10:18:46 AM »
I just read the entirty of the FAQ looking for the answer to this one question. And of course the answer is a link to a page that no longer exists.

I currently run 18 pedals on my board and for that reason do not run any batteries. I use a power supply similar to a voodoo. I want to do a 9 v adapter jack instead of a battery. And do not need to do a stereo input jack for turning the pedal on when plugged in.

Anyone have a schematic that would resolve this for me?

Thanks!

thelonious

Re: How do I put jacks for 9V adaptors on my pedals?
« Reply #1 on: March 14, 2013, 12:14:39 PM »
You need one of these, or something similar. They are 2.1mm center pin diameter, 5.5mm outer plug diameter.
http://www.smallbearelec.com/servlet/Detail?no=666
http://www.thaishine.com/servlet/the-1560/5-x-DC-Power/Detail

Many of these jacks have an internal switch that disconnects the battery when you plug in the power cable, which is what the third contact is for. There is a great graphic that demonstrates true bypass and switchable power wiring at http://www.cardenmusic.com/images/diy-guitar/3pdt-pedal-wiring.png .

Here is a graphic that shows pin assignments on the back of a normal switching power jack. If you are not using the input jack for switching, just wire that contact to a main ground point:

My apologies to whoever I ganked that graphic from. I saved it years ago and don't remember where I got it. If someone can identify its source, I'll link to it instead.

The easiest way to wire a DC power jack in is to cut off the battery connector and solder the black wire onto the "to input jack ring" contact and the red wire onto the "+9v to circuit board" contact. But if you're planning to resell the pedal at any point, it's better to wire the whole thing as shown in the two graphics.

And here is more thorough information if you want it:
http://www.generalguitargadgets.com/tech-pages/50-powering-effects/34-adding-a-power-jack-to-a-stompbox

VolksWilliam

Re: How do I put jacks for 9V adaptors on my pedals?
« Reply #2 on: March 14, 2013, 12:54:40 PM »
The easiest way to wire a DC power jack in is to cut off the battery connector and solder the black wire onto the "to input jack ring" contact and the red wire onto the "+9v to circuit board" contact.

Great. So basically I can wire any pedal with a dc jack by replacing the pos and neg battery terminals with the pos and neg on the dc jack?

aron


VolksWilliam

Re: How do I put jacks for 9V adaptors on my pedals?
« Reply #4 on: March 14, 2013, 02:39:36 PM »
http://www.diystompboxes.com/smfforum/index.php?topic=970.0

Thanks Aaron. I've actually seen that one. . But if I don't want a battery at all can I just omit it and those wires from the schematic?

thelonious

Re: How do I put jacks for 9V adaptors on my pedals?
« Reply #5 on: March 14, 2013, 02:48:45 PM »
The easiest way to wire a DC power jack in is to cut off the battery connector and solder the black wire onto the "to input jack ring" contact and the red wire onto the "+9v to circuit board" contact.

Great. So basically I can wire any pedal with a dc jack by replacing the pos and neg battery terminals with the pos and neg on the dc jack?

I can't think of a situation where that wouldn't work, unless something really unusual were going on with the wiring. The center pin of the DC jack will be negative.

Also, don't try to do this with PNP devices like positive ground fuzz faces unless your power supply has outputs that are isolated from each other.

VolksWilliam

Re: How do I put jacks for 9V adaptors on my pedals?
« Reply #6 on: March 14, 2013, 04:36:52 PM »

I can't think of a situation where that wouldn't work, unless something really unusual were going on with the wiring. The center pin of the DC jack will be negative.

Also, don't try to do this with PNP devices like positive ground fuzz faces unless your power supply has outputs that are isolated from each other.

Ok good to know. Most scematics the dc jack and the battery are wired different and I don't use batteries so this will make my projects a little easier. Thanks.