Introduction: Overdrive Pedal



An overdrive guitar pedal is kind of like a less harsh distortion pedal. Technically speaking, whereas a distortion pedal clips an amplified waveform at a particular height, the overdrive pedal actually rounds the top of the clipped wave. While this still makes it a bit fuzzy when you crank up the gain, it sounds less extreme than a distortion or fuzz pedal. What is cool about this pedal is that it adds a little extra warmth to your signal when you are strumming gently, but when you really strum hard, the audio spikes up into crunchy distortion territory. While this is generally a very subtle effect, it is actually quite robust in terms of the different types of sounds that you can get out of it. It is great for adding a little something extra to any effects chain.

Step 1: Materials

You will need:

(x1) 2N3904 NPN transistor (Radioshack #276-2016)
(x1) 0.1uF capacitor (Radioshack #55047557)
(x1) 0.047uF capacitor (Radioshack #55047555)
(x2) 0.01uF capacitor (Radioshack #55047551)
(x1) 100K logarithmic potentiometer (Radioshack #271-1722)
(x1) 100K linear potentiometer (Radioshack #271-092)
(x1) 10K linear potentiometer (Radioshack #271-1715)
(x1) 2.2M ohm resistor (Radioshack #55049482)
(x1) 33K ohm resistor (Radioshack #55049446)
(x1) 22K ohm resistor (Radioshack #271-1339)
(x1) 3.3K ohm resistor (Radioshack #271-1328)
(x1) 680 ohm resistor (Radioshack #55048032)
(x1) PC Board (Radioshack #276-150)
(x1) 9V battery snap (Radioshack #270-324)
(x1) 9V battery (Radioshack #23-853)
(x3) Knobs (Radioshack #274-415)
(x2) Stereo audio jacks (Radioshack #274-312)
(x1) Foot switch
(x1) BB project enclosure
(x1) 5" x 4" x 1/8" rubber sheet
(x1) 5" x 4" x 1/8" cork sheet

Step 2: Circuit

Build the circuit as pictured in the schematic, with the exception of the potentiometers.

The overdrive pedal schematic is largely based on two different circuits. The transistor stage of the schematic is based on the Trotsky Drive Pedal by Beavis Audio Researsch (itself based on the Electra Distortion module). However, instead of using a rare Russian NPN transistor, I used a 2N3904. All-in-all, this part of the schematic is largely just boosting the incoming signal, controlling the gain, and doing a little bit of filtering.

The lower half of the schematic is based on Jack Orman's page on tone clipping, and it is in this part of the circuit where all of the real overdrive magic is happening. Basically, there is a high pass and low pass filter in parallel, each of which is followed by its own pair of clipping diodes. Aside from the filters themselves having unique tone charachteristics, each pair of diodes also has its own clipping charachteristics.

The 10K potentiometer in the schematic sweeps between the two different filter / diode pairs. This potentiometer gives the pedal a very adjustable and unique sound. By swapping out the filter components and diodes for different values, you can experiment with the pedal and find your own perfect combination.

Step 3: Wire the Switch

Connect one pair of the switches outer terminals together.

Connect a 4" red wire to each of the central terminals.

Connect a 4" green wire to each of the outer terminals.

Step 4: Drill Guides

Print out the attched drill guides and affix them to the pedal enclosure.

Step 5: Drill the Top

Drill the three potentiometer crosshairs with a 1/4" drill bit.

Drill the center foot switch crosshair with a 1/2" drill bit.

Step 6: Drill the Sides

Drill both side crosshairs with a  3/8" dril bit.

Step 7: Clean

Remove the drill guides after all of the holes are drilled.

Step 8:

Use the attached template to make a spacer out of rubber or cardboard for the inside of the casing, and position it in place.

Mount all 3 potentiometers in place, with the 10K potentiometer being in the center, and the 100K logarithmic potentiometer being to its left (while the pedal is face down). Fasten them firmly in place with their included mounting hardware.

Step 9: Jacks

Insert the audio jacks into each of the side holes and mount them in place with their mounting hardware.

Step 10: Switch

Insert the stomp switch into the 1/2" hole and mount it firmly in place with its mounting nut.

Step 11: Connect

Connect each of the red wires from the switch to the signal tab on one of the audio jacks. This is the tab that has electrical continuity with the long bent peice of metal that comes into contact with the plug's tip.

Step 12: Wire the Pots

Solder a green wire between the center tab on the 10k potentiometer and the lefthand tab on the 100K logarithmic potentiometer.

Connect a 4" green wire to the center tab on the logarithmic potentiometer.

Connect 4" green wires to the outside tabs of the 10K potentiometer.

Connect a 4" green wire to the center tab of the 100K linear potentiometer, and a 4" red wire to the righthand tab.

Step 13: Wire Ground

Connect the remaining unused tab from the 100K logarithmic potentiometer to the tab on the closest stereo jack that is electrically continuous with the outer barrel.

Connect a 3" black wire to the same jack. This wire will later connect to the circuit board.

Connect the black wire from the 9v battery snap to the remaining unused tab on the stereo jack.

Step 14: Wire the Output

Connect the center green wire from the 100K logarithmic potentiometer to the switch such that it is connected next to the red wire which is connected to the stereo jack that is also connected to ground.

Step 15: Attach the Circuit

Attach the remaining components as appropriate to the circuit board based on the schematic.

Remember that the remaining green wire from the foot switch should connect to 'Audio In.'

Step 16: Insulate (optional)

To help prevent shorts, download the attached template and cut that shape out of a non-conductive material. I used cork for this purpose.

Glue the cutout to the inside of the lid.

Step 17: Power

Snap the battery into the 9V connector.

Step 18: Case Closed

Put everything inside of the case and fasten it shut.

Step 19: Knobs

Turn all of the potentiometer shafts all of the way to the left. Place the knobs onto the shaft and fasten them in place using their set screws.

Step 20: Use

To use the pedal, simply plug it in between your guitar and your amp.

If it does not sound like the pedal is doing much of anything, press the switch.

You should now be ready to rock and roll.

Comments

author
AngelKnight113 made it! (author)2017-05-23

What the Hell.. I dont know what pot to use on the Gain cause the List said 100k but The circuit said 50k and the Resistor.. The circuit said 22k but the List said 22ohm.. Idk what to use.. And what color to use on LEDs ?

author
randofo made it! (author)randofo2017-05-23

As a general rules, always go by the schematic... anyhow...

It is listed between 33K and 3.3K, so it should be 22K. Thanks for pointing out the typo.

In terms of the potentiometer, I don't think it should matter too much. Start with 50K. If that doesn't make you happy, try 100K. There are not many hard rules to this.

Here are some potentiometers of different values:

https://www.amazon.com/Knurled-Linear-Rotary-Poten...

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pavan7495 made it! (author)2015-06-29

How long does the battery last? I mean since we are shutting the battery inside, will I have to screw it open every other day to change the power supply?

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Hachmamut made it! (author)Hachmamut2017-03-29

Those circuits normaly have currents less than a mA. Its important to unplugg the input jack cable if you stop playing, since this cable serves as a connector to ground for the battery. If you unplugg the cable it's like turning the device off.

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jmwreck made it! (author)jmwreck2015-10-21

if you have a multimeter, you can check the current rating of the pedal and from there you can compute how many hours your battery will last.

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JamesL290 made it! (author)2017-03-15

The arrow part of the symbol is the middle pin of the pot. You can simply wire pins 2 and 3 of the pot to each other, or simply use pins 1 and 2 and leave pin 3 unconnected in this case. The circuit will operate the same either way.

This is a good guide:

http://www.build-electronic-circuits.com/potentiom...

author
DanielL497 made it! (author)2016-12-11

how to connect this part?

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Raiden11 made it! (author)2016-11-07

In step 2 there is no image of the schematic!! Can you please re-uplode it :)

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DuyH8 made it! (author)2016-04-17

Unfortunately, I followed everything in this instruction but nothing seems to work. I don't know if it's correct to connect the barrel lug of the jack which is not connected to ground to ground. Have any ideas, guys? I'm stuck

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DuyH8 made it! (author)DuyH82016-04-18

And i'm using a c2383 transistor instead. Is it good or do i have to change it?

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ChristinD made it! (author)ChristinD2016-09-10

Hello, I'm struggling to pin down the datasheet on your transistor, but one datasheet I observed showed a transistor with a turn on voltage of .45 to .75 while the transistor in this instructable turns on at .65 to .85/.95. Mayb your transistor isn't on. I'm sorry.

author
etanercept made it! (author)2016-07-19

Is it possible to do this with DC instead of battery? Some circuits make a hum when you replace the battery for a DC converter (even the finest) :)

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DrGoob made it! (author)2016-04-18

Are the grounds on the diodes only attached to the ones facing up, or to both diodes in each set?

author
Dr_K made it! (author)2016-02-14

I know this Instructable is a little "dated", but it looks like a fun and interesting project. I am not an electronics guru (I'm kind of a hack) and pretty new to transistor circuits.

I my understanding right--when you turn down the gain pot (ie, to lower resistance), it increases the gain? The 3.3k resistor is just there to limit the gain of the circuit?

Thanks for posting/designing,

John

author
Anargopunk made it! (author)Anargopunk2016-04-01

yes, by turning the gain kob to a lower resistence, the gain gets higer, keep this in mind while making the pedal so you don't have reverse knobs, i've had that a few times and it sucks

author
Dr_K made it! (author)Dr_K2016-04-01

excellent, thanks or the response. I know what you mean--several of my op-amp circuits come out that way, and I need to reverse the leads so clockwise=increased gain....

I recently purchased a little USB O-Scope which is great for tinkering and testing these things. It would be good to know how high you can go before the transistor distorts, how high you need to go to the get the clippers to clip....

Really enjoyed this build. It sounds good and raunchy. I put it in this swirl painted box.

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Jrmo14 made it! (author)2015-03-25

I'm a bit green in terms of electronics, what type of diode should I use?

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jmwreck made it! (author)jmwreck2015-10-21

if it's for a clipping diode, you can use a variety of diodes, you can even use an LED. If you want options, you can make it switchable

author
Mário Conti made it! (author)2015-07-03

Can I replace the resistor 2.2M on the other? I did not find anywhere!

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jmwreck made it! (author)jmwreck2015-10-21

you can series 2 x 1M resistors

author
KROKKENOSTER made it! (author)2013-10-11

This is a cool little circuit but do you know where this came from? I have forgotten who the group was but it was a pop group whose loudspeakers had a tear in one of the cones. They did not have the money or time to replace/repair this as it happened just before the gig. Their audience liked this new sound so much that they dared not repair this and this was then made electronically with tubes ( Early'60 's) New popular sound due to poverty we may add.

author
savage-drummer made it! (author)savage-drummer2015-06-12

The kinks?

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Scarface Claw made it! (author)Scarface Claw2013-10-11

The Kinks.

author
666_noscopebys8ncauseyolo_666 made it! (author)2015-05-16

can someone make a video of how to do this step? i only know the very very basic stuff on electronics and am confused. thanks

author
666_noscopebys8ncauseyolo_666 made it! (author)2015-05-16

what are the dimensions for the box?

author
Mark TimothyO made it! (author)2015-04-14

Thanks for that. I'll wait for it. I'm really struggling with the breadboard version of this project. I tried to connect it to the guitar and the amp. It has a sound but it's just a clean tone sound. I can't produce the expected overdrive sound of this pedal. I'm currently doing this as my project in school. Your help would be very much appreciated. Thanks bro.

author
drskyskull made it! (author)2014-06-02

Just put this together -- well, a breadboarded version so far -- and it works well and sounds pretty cool! Be sure to pick up the two LEDs and the 1N4148 diodes, which are not in the parts list.

Thanks Randofo!

author
Jrmo14 made it! (author)Jrmo142015-04-06

thank you so much

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Jrmo14 made it! (author)Jrmo142015-04-05

I am also confused with the wiring. Would it be possible for you to post a picture of your breadboarded version? Thanks.

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drskyskull made it! (author)drskyskull2015-04-06

Was out of town the past week -- I'll take it apart tonight and take some pictures!

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Mark TimothyO made it! (author)Mark TimothyO2015-03-29

Hey bro. Would you be able to post a photo of the breadboard version that you did? I'm currently working now on this project and I'm just really confused on the wiring. Thanks.

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AdanR1 made it! (author)2015-03-05

What if i want to remove the TONE potentiometer, could this work? Thabks!

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Djenne made it! (author)Djenne2015-03-18

I think it could work; you could put a resistor there with a value somewhere between 0 - 10kOhm, and I think 10kOhm will give you the max. amount of tone and 0 the min. amount. However, I'm just starting with electronics, but this is how I understand it.

author
Djenne made it! (author)2015-03-18

Since in the parts list there's two 100K pots listed, one linear one logarithmic, but in the schematic there's one 100K and one 50K pot listed, I was wondering which of those is logarithmic and which is linear? And what is the result if I use a logarithmic where a linear pot is listed, or the other way around?

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syberdiver made it! (author)2015-01-22

Verry Nice! I will build it soon :-)

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cyrisis made it! (author)2014-08-28

I followed the schematic to the last. But I'm facing the 'clipping' issue. When attack is increased even a little the 2N3904 goes into clipping mode and more than half of my sustain is lost and this happens with my Gain Pot (50k) being at ZERO position. If I increase Gain even a little, the sound becomes utterly torn appart and its beyond what distortion pedal would sound like. Also when I connect it in series with a hand built distortion pedal, the bass frequencies get filtered (Guitar >Dist > OD > Amp). If I alter the position (Guitar > OD > Dist > Amp) the sound becomes a little better but its still not what your pedal sounds like. The pedal alone just sound very lost to me :( I'll upload the image of what I've made up. Any tweeks that I can do it make it like yours?

IMG_20140828_133625.jpgIMG_20140828_133710.jpgIMG_20140828_133741.jpgIMG_20140828_133809.jpg
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cyrisis made it! (author)cyrisis2014-08-28

Sorry I forgot the add, the Vol. also needs to be kept upto 50% and tone doesn't work change anything at all :( I've traced the schematic with my build and its perfectly same. Diodes however were random from my old components box. But as I've read the comments, diodes should effect the tone type and not the over clipping of transistor. What I mean is that my pedal has no clarity at all :( I've checked ground connects if there was a shortage or not. The build seems to be fine except i can't identify any sound at all. I live in Pakistan and its difficult to find components. is it the quality of components that is effecting?

author
Antoine D made it! (author)2014-08-20

Hi, I would like to know if it's a 50k potentiometer or 100k ? Cause the schematic shows you need a 50k and the list of objetcs shows you need a 100k... Wich pot used ?

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iobee made it! (author)2014-07-13

love this :) thanks for sharing this..

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ckts made it! (author)2014-06-30

Put this pedal together and it sounds awesome (especially with other effects). Updating the parts list with what is on the schematic would be nice too. There are a LOT of inconsistencies such as a different pot value, different resistor value (22 ohm and 22k), missing diodes and LED's etc. Overall, it's a rewarding experience for somebody who is brand new to building their own pedals such as myself.

author
DastardlySexy made it! (author)2014-04-17

I love how neat and clean everything is, but I do have a concern with the parts list/schematic- it seems like you have parts in the schematic that aren't listed on the list (those extra two diodes, for example), and there's a label for a second transistor but no transistor there (the 1N4148)? Maybe I'm missing something, but I'd love to give this project a swing. Very tight Instructable, friend!

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Maggoo made it! (author)2014-04-05

looks good, cosmetically. I find it odd that you went to the trouble of a produced video that didn't showcase the sound of the pedal (or, uh, it wasn't distorted sounding).

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rjohanson made it! (author)2014-03-21

Can you tell me more accurate how you connected stereo jacks, my pedal dont work and I think that I have problem with stereo jacks. Can you send me some pic. about step 14.

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WadeRS made it! (author)2014-03-12

the schematic doesn't seem to be there anymore?

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randofo made it! (author)randofo2014-03-14

It is still in Step 2

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kimjames229 made it! (author)2013-12-08

Hey randy! I am currently making this od pedal and I was looking at the picture of your circuit board and it seems like a lot extra soldering is done on the other side, is it possible to get a clear picture of that? And also it seems that there are two extra resistors on your board that's not listed on the schematic??

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randofo made it! (author)randofo2013-12-08

I didn't have a 2.2m resistor on hand, so I used two 1M resistors and a 200K resistor in series.

Honestly, the speed at which I might get another picture posted is not going to be very fast. Most of the connections on the underside are largely ground connections. I'd just go by the schematic.

author
jpacheco4 made it! (author)jpacheco42014-01-21

I need the pictures from above and below too! It has been a while since the last time I translated a diagram into a perf board so that could really help me. Please!

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Malstrøm made it! (author)2013-12-30

Overall price??

author
ElectricProjects made it! (author)2013-12-08

How much did this cost overall??

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Bio: My name is Randy and I founded the Instructables Design Studio. I'm also the author of the books 'Simple Bots,' and '62 Projects to ... More »
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