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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.


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41 comments:

  1. fuzz daddyMay 14, 2015 at 9:47 PM

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

    ReplyDelete
  2. tinchexJune 5, 2015 at 9:16 AM

    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. MaurusAugust 3, 2015 at 9:23 PM

    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. MaurusAugust 3, 2015 at 10:11 PM

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

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  5. Hannibal LecterNovember 13, 2015 at 9:46 AM

    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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    Replies
    1. dtgehringNovember 13, 2015 at 9:51 AM

      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.

      Delete
    2. Hannibal LecterNovember 16, 2015 at 5:38 AM

      Thank you very much!

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    3. Hannibal LecterNovember 16, 2015 at 5:56 AM

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

      Delete
    4. dtgehringNovember 16, 2015 at 9:19 AM

      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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    5. Hannibal LecterNovember 16, 2015 at 9:39 AM

      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.

      Delete
    6. dtgehringNovember 16, 2015 at 9:44 AM

      Thanks. Glad you had a good build.

      Delete
  6. RyanFebruary 16, 2016 at 9:57 PM

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

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  7. eXaNQFebruary 29, 2016 at 5:04 AM

    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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    Replies
    1. Effects LayoutsFebruary 29, 2016 at 9:40 AM

      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. eXaNQFebruary 29, 2016 at 4:46 PM

      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

      Delete
    3. Effects LayoutsFebruary 29, 2016 at 5:07 PM

      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. eXaNQFebruary 29, 2016 at 5:50 PM

      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. eXaNQFebruary 29, 2016 at 5:53 PM

      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. Effects LayoutsMarch 1, 2016 at 9:20 AM

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

      Delete
  8. fredApril 22, 2016 at 4:19 PM

    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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    Replies
    1. Effects LayoutsApril 22, 2016 at 5:44 PM

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

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  9. fredApril 22, 2016 at 7:28 PM

    thanks.

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  10. fredMay 22, 2016 at 2:39 PM

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

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  11. UnknownMay 23, 2016 at 12:00 PM

    Thank you!

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  12. UnknownMay 29, 2016 at 12:23 PM

    This comment has been removed by the author.

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  13. Leonardo Rosa September 8, 2017 at 11:15 AM

    Why is the led on the board?

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  14. Drёn13September 15, 2017 at 4:19 PM

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

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  15. UnknownDecember 6, 2017 at 5:11 PM

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

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  16. CANEPLAJanuary 4, 2018 at 6:58 PM

    I did one but had twice the same problem. For 5 minutes it worked perfectly well, for another 5 he started to go dying slowly and soon after he did not sound any more. I already checked the values ​​of the components and track of both and I do not think error, what can be? The only modification was a B25k for an A20k

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  17. Marble IndexMarch 23, 2018 at 7:08 PM

    This comment has been removed by the author.

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  18. Ricco SeixasJune 5, 2018 at 3:42 PM

    verified !!!
    great sound, already mounted 7 pedals of your site and all work perfectly, congratulations for the great work !!!

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  19. AnonymousJune 11, 2019 at 5:13 PM

    Hello can i ask you ? In this ocd is located condesator 10uf how to install? Left or right ? Please help meee :/

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  20. Ricco SeixasFebruary 7, 2021 at 9:38 AM

    Work with 18v?
    can i use the 555 charge pump from the website for this and get more headroom?
    Thank you!!!

    ReplyDelete
  21. Ricco SeixasFebruary 7, 2021 at 5:07 PM

    works great with bomb charge 555 from here, thank you very much, greetings from Brazil !!!

    ReplyDelete
  22. Manu AltamiranoAugust 31, 2023 at 9:28 AM

    Hi, i'm having a couple problems, so any comment is appreciated
    1- is leg 3 in the drive pot not connected to anything?
    2- Is it a problem if you don't use the onboard led pad?

    ReplyDelete
  23. Emiuser04May 15, 2024 at 10:19 PM

    Can somebody tell me, how do I have to connect the spst?

    ReplyDelete