Homemade Distortion Pedal


View Full Version : Homemade Distortion Pedal

12-17-2005, 03:41 AM
I was bored the other day, and i found this simple circuit here for a distortion stomp box: http://smallbox.zeonhost.com/projects/fface/

So i decided to build it :D It didnt take me long to make, and suprisingly I had all of the bits laying around from old VCRs and old electronic junk that i have collected over the years. The only think i had to buy was the knobs and the foot switch.
It sounds suprisingly good for what it is.

Here is the circuit:

The first box i made was a crappy wooden thing, and i drilled the holes wrong to start with :P

Here is the final box which i got my dad to make at work.

12-17-2005, 03:44 AM
lol sorry guys, the image name had swearing in it :P
here are the last 2 pics:

12-17-2005, 03:51 AM
Sound clips?

Looks cool, hows it sound?

12-17-2005, 04:02 AM
yea it does look cool, but hows the sound.

12-17-2005, 04:07 AM
Nice, I made one of those a while ago too:

heres a clip http://seljer.dmusic.com/

(the trimpot lets you use a wah wah in front of it and set your guitar volume on 0 without it going buzzing, the 3rd pot is controls the area from 10 -> 11 in a way)

I built it along the Fuzz Face with Fuller Mods Schematic here http://geofex.com/Article_Folders/fuzzface/fffram.htm

I used AC128s for the transistors (so germanium ones like in the originals...though I've heard these aren't the best)

12-17-2005, 04:22 AM
good work! the transistors i used were just generic things i had laying around, but there is very little hum.
Sorry guys, i dont have a microphone for my computer or anything, so i cant record it.

12-17-2005, 04:30 AM
good work! the transistors i used were just generic things i had laying around, but there is very little hum.

I'd sax hum thing is more from the design of the pedal that the actual transistors. You probably noticed that the thing can basically turn clean at lower settings, the pedal isn't a high gain distortion (no screaming harmonics...), its a ripped speaker type fuzz.
So any hum there is doesn't really get amplified...

12-17-2005, 03:00 PM
I built the multi fuzz face a while back, with practically the same circuit, and its always got a bit of hum when off, but recently ive been wanting to eliminate this because im becoming more picky about my live sound. when my foot touches the footswitch the hum gets louder, but if I touch the metal part of the guitar cord which is plugged into the pedal anywhere between guitar and pedal, the hum disappears completely adn i can touch anything else metal and there is still no hum. My guitar sound is not affected by the touching of metal things but the hum just increases or decreases etc.

anything i could do to sort this out since im on holiday?

12-17-2005, 03:04 PM
That would be a grounding problem of some sort (on your guitar as well)

12-17-2005, 04:20 PM
Its definantly not my guitar, because when that's plugged in purely to the amp there is no hum at all. It's an electro acoustic guitar in any case so i doubt very much if it had grounding problems. When i use purely my wah theres no hum, so that rules out the possiblility that its the cables. Its definantly the fuzz box!! How do i go about grounding this? My case is made of wood, everything works ok, but i just want to get rid of that hum, the hum is present when on and in bypass mode. If you could give me some solutions to fix this it would be great.


12-17-2005, 04:25 PM
The wooden case is probably the problem. It doesn't shield out interferences.

Also, are the grounds from both the input and output jack connected together?

12-17-2005, 04:28 PM
Oh right its the case... Could i line the inside of the case with tin foil or something and keep my circuit in like a plastic bag to prevent short circuiting? as for the input and outpu jacks being connected together... i connected them both to the "common" on the circuit board so they are connected together yes. Would my tin foil plan work? I mean should i use alimnium foil instead or anything...

12-17-2005, 04:32 PM
any kind of metal foil thing will work. I found a roll of adhesive aluminium tape at a hardware store that I shielded my guitar with but tin foil will work fine.

you don't need to keep the thing in a plastic bag, just cover up the side its sitting on with tape or paper or whatever...or glue it/mount it somehow so it doesn't dance around

12-17-2005, 04:38 PM
What I will do is line it with foil, stick it in etc then cover the foil with an insulator material, maybe stick the circuit board on little wooden legs (previously i had my 9v battery stuck in place by blue-tack and the circuit board let free, basically dancing around!!).

Cheers seljer, you've saved the day! :D

12-17-2005, 04:40 PM
remember that the foil also needs to be connected to ground to work (one of jacks need to touch it....)

12-17-2005, 04:44 PM
I think I'm going to build this. But first, do the transistors make the pedal or are there any other things I could do to make it better? Is there anyway to add a led?

EDIT: what ARE the best transisters to use?

12-17-2005, 04:45 PM
ah, should I connect it to the "common" on the circuit board or actually solder a wire directly to the the bit which touches the tip of one of the jacks?

Edit: to the person asking about the transistors:
The transistors I used were highg ain ones, it depends on the amount of gain you need and what your circuit is hoping to need (NPN or PNP / whether its a fet / MOSfet etc it all depends on the circuit you are intending to use. For my home built distortion pedal that i am talking to Selj about I used 2N7000 transistors.
is where i got my ideas from, i used different capacitor values than that suggestd though ;)

12-17-2005, 04:48 PM
I think I'm going to build this. But first, do the transistors make the pedal or are there any other things I could do to make it better? Is there anyway to add a led?

theres a huge amount of things you can tinker with in the fuzzface circuit http://geofex.com/Article_Folders/fuzzface/fffram.htm

as for a LED:
get a 3DPT footswitch and have the 3rd part turn on a LED with a resistor connected to it in series (1k-10k depening on how bright and how much battery life you want it)

ah, should I connect it to the "common" on the circuit board or actually solder a wire directly to the the bit which touches the tip of one of the jacks?
well the ring part of the jack is allready connected to the ground, so if that part is touching the foil it'll also be connected

12-17-2005, 04:52 PM
excellent, so i connect a wire from the foil, to the RING or the TIP of the output jack? I just want to make sure i dont make too many mistakes ;)

12-17-2005, 05:02 PM
well you dont need any wire, if you have the regular type jacks ( http://www.giantcomputerstore.com/a/Audio_Adapters/Switchcraft_1_4_Female_Phone_Jack.jpg ) that entire part around the washer and nut is also part of the ring section. So you allready have that connected to ground right now, you just have to make sure the jack is screwed into a part where its touching the foil

12-17-2005, 05:07 PM
yeah I see what you mean, what I'll do is just loosen the otput jack a bit, fold the tin foil round the edge of the hole, screw the washer back again, and voila! bodge job complete :D

once again, thankyou for your help!!

12-19-2005, 06:14 AM
it's all worked! hallilujah no more hum!!!
Another niggling factor I have is that when my foot touches the washer of one of the volume knobs or the actual footswitch there is alot of hum, then when i take my foot off, no hum. Can I get the foil to touch the washer of the volumer knob to solve this problem?

I must say the background hum has disappeared almost completely!!


12-19-2005, 11:10 AM
Yeah, I believe the switch and enclosures should be connected to the tin foil as well

01-03-2006, 04:55 PM
can you use any PC Boards?

lookie here
01-04-2006, 03:50 PM
for the booster one would you be able to add a LED to it?