Build A Power Supply For Your Guitar Pedals

Step 7 Finished!

You now have your very own guitar pedal power supply!  Use it to run your pedals without having to waste batteries and streamline your pedal board or setup without needing several DC wall adaptors.

The beauty of this design is it is very customizable and expandable.  If you include a center-tapped transformer you can add negative voltages to power some elaborate homebrew pedals or amplifiers.  The possibilities are endless and this is a great starting point. 

I hope you liked my Instructions.  They're a little long in the tooth but I wanted to make sure that the maximum amount of information was available with minimal misinterpretation.  Please leave a comment if you have any questions or thoughts.

Thanks for reading!


Matt

Comments

[MusicManDR3W]

what output are your 9v supplys? Im trying to find a build for something to power my 200+mA pedals

[mattthegamer463]

The 7809 regulator comes in a TO-220 package which can deliver 1A. If your transformer can deliver 1A at its rated voltage per regulator, you're all set.

[monchis30]

This is my first proyect,, and I have to say thanks, what a great experience, I started Saturday morning without knowing absolutely nothing about electronics and ended today with a great power supply.

My design its simpler ,I did it for only 9v,. It took me a long time to understand the diagram and I more than triple check everything and did everything very carefully

One question..How many pedals can I daisy chain from a single line(or whatever its called)? , for what is worth I used the smaller  100uF capacitors and currently Im daisy chainning 2 overdrives and a wah without any problems, but I may add another one or two pedals more in the short future.

Thanks

Heres a couple of pics

[mattthegamer463]

Nice job. Those regulators should deliver 1A at maximum load, and each of those pedals probably doesn't ever draw more than 100mA, so you could probably daisy chain 5 or 6 or so without issue. Worst case scenario is that the chip will overheat and shut off, but no damage done.

[amarafioti]

hey man, great tutorial! I'm a noobie in electronics, I've builted power supplies before but your design really caught me. Great building! and it seams really solid. Just, why didn't you used any dissipators or heat sink? and, how can i know how much current is being drained away through the led?
Txs for the tutorial man, it's great

[mattthegamer463]

The regulators can run up to 1A without heatsinks, and I won't ever need that much power, that is a lot of power. The small transformer I used can't even deliver that much if it wanted to, its only rated for 300mA.

To find the current through the LED take the supply voltage minus the LED voltage (5V - 2.1V = 2.9V) and divide it by the resistance in series with the LED (220 ohm) and you get 13mA. A little lower than the maximum for the LED which is 20mA so it will work fine and not be too bright.

[Electronics Blurred]

Well not really , i did 800mA through a 7812 ( i forgot my heatsink ! ) , it overheated instantly and shutdown was engaged .

[mattthegamer463]

Ah. Perhaps the engineers fudged some numbers on the datasheet. I bet if your input voltage was only 1V above the output voltage it could do 1A, that would only be 1W of heat, really not that much.

[Thereyouhaveit]

IT was worse , man , mine overheated w/o the input v over the output , because i was a fool at the time , because somebody recommended me a 7812 , even with a 12v input , i wasn't a electronics engineer at that time ... so it was only doing dropout voltage yet 1.7W+/- overheated it ...

[mattthegamer463]

That's only about 150mA output current then... very strange. Maybe the junction was mis-attached to the tab, resulting in a junction-to-ambient temperature coefficient far worse than the specific rating. Only explanation I can think of unless the regulator wasn't meant to run at near-dropout. Some are low-dropout and some are not, I think. Some require 1V+ above output to function effectively.

[Thereyouhaveit]

Probably yes :\

[PoloyTisoy]

How do you change the 9v DC output to AC? cause there's some effect requires AC power...

[mattthegamer463]

To be honest I have no idea how to build a regulated 9V AC supply. Cutting out the caps and the regulators would get you AC outputs, but not 9V without a 9V transformer and a certain amount of current loading.

[Pedrojoca]

that was a REEEAAALLY good tutorial :D , it helped me a lot.keep em' coming