This is a library of perfboard and single-sided PCB effect layouts for guitar and bass. I'm not an electrical engineer by any stretch of the imagination, just a DIY'er who likes drawing layouts. It is meant for the hobbyist (so commercial use of any of these layout is not allowed without permission) and as a way to give back to the online DIY community.

Wednesday, January 21, 2015

Fulltone OCD - Version 1

There are now 4 version of the OCD. The latest has a few guitarist I know wondering what was wrong with the last version, so if you're looking to go back to the original circuit, this layout is for you. The OCD one of the most respected overdrives out there. Derived from the Voodoo Drive, it uses two 2N7000 mosfets for clipping. I opted to make the tone pot offboard to allow a little more freedom with pot placement in the enclosure. Might not be a bad idea to use long leg pots for the Drive and Volume pots.


33 comments:

  1. Hey I built the OCD following your pcb. It works! Verify that and thanks for the layout

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    1. Thanks for the verify, fuzz daddy!

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  2. Hi, thanks for your designs. attempt to assemble this circuit but fails to have gain, it sounded very low, seeing the schematic I realize a diode failure before trasistor, it incorporates it and began to walk well, really it needs the diode there, thanks a greeting.

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  3. Sounds great!the tone pot It is wired backwards.green wire goes to 1 and the blue o 2/3.

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  4. https://www.youtube.com/watch?v=W2M8YpMCDtA

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  5. Hi,

    I saw some layouts that show a 100R resistor. Is it missing or it's irrelevant to the schematic? Thanks.

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    1. That 100Ω resistor is just a power supply filter resistor. Not all that necessary, but not a bad thing to include. Not sure why I didn't include it or if the schem I worked off just didn't have it. Or if V1 OCDs just don't have it. If you want to include it, just connect one side of it the 9v pad and the other to the DC jack.

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    2. The diode tinchex talked about is really necessary or the OCD don't have it?

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    3. I'm not really sure what he's talking about. None of the schematics or layouts that I've seen using diodes for clipping. You could, it just won't sound like an OCD. The MOSFETS in the layout are where the clipping happens (maybe he didn't use the right transistors?).

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    4. You're right. I just built this one and the Mosfets are enough to provide all the gain it needs. Just converted mine to V3 changing the pots and the 100n cap to 47n and I can say it works way better than the Fulltone V4 I had once. Thanks again, I'm a big fan of your work.

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    5. Thanks. Glad you had a good build.

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  6. great overdrive. sounds awesome. Tone pot is wired backwards per illustration.

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  7. can anybody explane what i have to solder to led hole. i am using true bypass switch and i am soldering led to that switch. help me pls
    ???

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    1. Wire the LED pad to the anode of the on/off indicator LED. Then wire the cathode to the footswitch. See the General Layout Notes tab for more info.

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    2. thanks for reply, i did what you said but it is not working and led is not working too. i really be preasure if you send diagram circuit board with true bypass. i know your time is expensive but i am not expert pls bro. magic66ster@hotmail.com

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    3. Are you wiring the "Sw1" and "Sw2" pads to the footswitch? Those pads are for a toggle switch that alters the tone, not the on/off footswitch. The In and Out pads go to the footswitch. Google is your friend here. There are plenty of diagrams online for how to wire up a pedal, as well as several schematics for the OCD.

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    4. no sw 1 and sw 2 pads to another on off switch. i did 4 true bypass pedal. and there was a no problem that led pad on the circuit is confusing my head.

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    5. can i ask a question? is there any example diagram for me ? for example true bypass switch with like this circuit board?

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    6. Try this: http://bit.ly/1QRA6f9

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  8. brother if i dont want the spst. do I need some bridge on the pcb? or remove any component?, I just want the pedal on LP mode.

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    1. I think to keep it in LP mode you'd jumper the 2 switch pads.

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  9. tone 2 and 3 together to ground? drive 2 and 3 together?

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  10. This comment has been removed by the author.

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  11. Replies
    1. It's not. The current limiting resistor is tho.

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  12. Hey. Please tell me which version it is? 1.4 , 1.7 ?

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  13. Hi! could you send me the Gerber file for the pcb? can you send it to me via email?

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