Simple Overdrive Effect Pedal

This is a very simple overdrive effect. There are a lot of same kind of effects on the net, but I decided to design something simple. It's a great beginner project.

This is me playing with it:
http://youtube.com/watch?v=z-1BsJz9Cpk
First I play clean, the switch on the effect.

Step 1: Diode Clipping

Overdrive or distortion occurs, when signal is amplified too much. Amps have an upper limit of volume. If a sound signal is louder than then it's peaks are simply chopped off. That is called clipping (distortion).

We can simulate clipping, by placing diodes between the signal and ground.

Step 2: The Schematic

Now it's time to build one for yourself too!

This is what you need:

6.3mm stereo female jack
6.3mm mono female jack
DPDT switch
0.1uF capacitor
LM386 op-amp
220uF electrolytic capacitor
47k resistor
100k resistor
red LED
two 1N4148 diodes

Incase you don't know, how to read schematics, there are a plenty of tutorials available. Just Google

Comments

[JatinK007]

Can we use this pedal for bass guitar too? Or is it only for guitar?

[marrymay]

Excellent write-up. I absolutely appreciate this post. I did try this way to build an overdrive pedal! and it's nice, check on this overdrive pedal

[cardboarddude]

I built the circuit and when I connect it to my guitar, I hear the radio! What did I do wrong?!!

[ilovegm]

Shielding, enclose the electronics in a conductive material of sorts (faraday cage)

[tsamarakoon]

Instead of 1N4148 diodes, could I use 1N5818 schotky diodes? and for the OP amp, should it be an LM386? Can't it be another op amp model?

[666sebas999]

Something wrong happened, It didn't work and I tried to figure out what happened; I found this, even with the effect on bypass the signal isn't going through; when I unplug the DC power, signal goes through bypassed-effect. This have never happened to me before, can someone explain me what just happened?

Thanks :)

[maheshsankaran]

I found that by connecting the diodes to the switch (top right point of the switch) rather than to ground, I get much more distortion. With the circuit as shown above, I get lots of overdrive, but hardly any distortion. Does that make sense?

[yrosema]

I made mine like this:

added drive pot and 2x 1M resistor because it was too loud.

[badad]

does it need another kind of jack or the regular will work?

[Jahiruddin]

Dear
Thank you for provide this circuit diagram but now I like to test sound . Is it possible . Please help me.
Jahir

[Jahiruddin]

Dear
Thank you for provide this circuit diagram but now I like to test sound . Is it possible . Please help me.
Jahir

[yrosema]

I read somewhere that if I use a 100uF capacitor in stead of the 0.1uF one I'd get more bass. Is that true?

[666sebas999]

Does it need to be a LM386?
because i get a LM731 from an old recorder, can I use it too?

[pfred2]

You may be able to build one of these:

http://www.google.com/search?hl=en&q=mxr%20distortion%20741%20schematic&gs_sm=e&gs_upl=2229l13479l0l14617l28l28l0l18l7l0l257l1696l0.6.4l10l0&um=1&ie=UTF-8&tbm=isch&source=og&sa=N&tab=wi

[pfred2]

You had me all pumped up what happened?

[serverfp]

Como puedo descargar los pdf ayudenme chicos

[91chevywt]

Hey i've got a quick question for you. I've got everything together, as indicated in the diagram, and when I have it hooked up all switching the switch does is amplify the sound almost double. There is no distortion, just loud and clean. Do you have any idea what could be causing this? I checked my resistances with an ohmmeter and they seem to be in line with what the schematic calls for. Other than that i'm not sure what else to try.

[odopudj]

Try pins 1 and 8.connect directly or put 10 uF capacitor between pins

[PowerslaveNSHC]

Can someone write me schematic for volume pot or gain pot or both of them? Regrets and thanks!

[Guitar_slave]

PICKO madjarska stavi pot od 100 k tamo gde ti cika stewa reko!!on je dobar covek slusaj ga!!!al dzabe ti kad nemash lemilicu XD eheheh