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.

Tuesday, October 26, 2021

PedalPalFX PAL 800

 By popular demand, here's the PAL 800, a well regarded Marshall-in-a-box circuit. Should fit nicely in a 125B. Schematic here. All the trimmers except the one just below the Volume control are for biasing the JFETs. Start at 4.5v on the drain of each JFET and adjust by ear from there. The other trimer is for smoothing out the output signal.







13 comments:

  1. Very nice. Would love to see the PAL959, if anyone has the time.

    SIDE NOTE: This is almost identical to the JCM800 JFET circuit provided by Electrictabs, YEARS ago on one of the DIY pedal sites. Only differences one the PAL800 is some of that filtering at the end, and the added presence control.

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  2. this pedal is awesome, I think I'll build it, I'll just omit presence control 25kb and 100n

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  3. Replies
    1. Yes, though you'll need to adjust the trim pots to 6v when biasing.

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  4. I'd like to build the new version: PAL 800-V3 GOLD Overdrive.
    It has a second footswitch to get a sort of low input and high input mode; a toggle switch for the MOD #34 sound; and a toggle switch to get different voicing.

    I guessed it's about the same PAL800 basic schematic with some little mods and adding, but it seems to have a bit of too much extra parts. The schematic is unknown.

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  5. You can call it verified. Sounds like it should. the tone controls seem subtle and the master tone control doesn't do as much as I was expecting either. I don't have the actual one to compare it too. It sounds great! Probably just like the amp.

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    Replies
    1. I built the JCM layout with the high/low input footswitch that's on Tagboard. The eq wasn't massively effective on that either.

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  6. Hello, can you make a simple Boss MT2 pedal layout and schematic?
    or can someone tell me the layout or the site on google which is easy to understand.
    too hard to find layouts and schematics on google.
    Thank you from Indonesia
    Sorry my english is so bad

    ReplyDelete
    Replies
    1. https://rumunsko.mypage.cz/menu/kytarove-efekty-a-pedaly/mt-2-metal-zone

      I have been searching on the same subject and came across this web site. Auto-translate helps a lot.

      This web site gave me so many good pedals and understanding on building and repairing them, this at least helps admin friend on handling requests. :)

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  7. which pot is to adjust the Drain on Q4

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