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.

Monday, December 21, 2015

EarthQuaker Devices Acapulco Gold

Here's a fun distortion from EarthQuaker. Tonally, it's based on a cranked Sunn Model T amp and uses 2, 386 chips. It cleans up nicely with the guitar's volume, so a good mod would be adding a pot before the input. John K did this and used a reverse log 1M pot.



56 comments:

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    1. The new pot would be a 'pre-gain' control, which is the same as turning your guitars volume down.

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    2. someting else that i never use ;)

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  2. very loud pedal, with vol knob at full i can drive a 8inch speaker :)

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  3. i built this, havent tested yet. the reverse side of the schematic is not exact the same as the front but it havent caused any problem though thanks

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  4. ehmm well on second thought i still like the crunchbox

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  5. What do you think, is it worth to do this pedal? Is it work? What the sound&

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    1. It's verified. Watch the video for how it sounds.

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  6. I built 2 of these pedals and both get crazy squeeling when above 75% volume. Anything I can do to tame this a bit?

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    1. An easy fix would be to wire a 22k resistor between the output cap (1µ on the far right) and the Volume pot. That would would make the max volume less, but would probably eliminate the squealing. It's a ridiculously loud pedal in the first place, so it should still be well above unity with that mod.

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    2. Thanks! While I've got you here I just want to say that your site is an incredible resource!

      Seriously, thank you. I mean it!

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    3. Thanks man! Glad you're finding it useful.

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  7. I builded this pedal and works fine, thank for effectslayouts. Sounds like angry fuzz.

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  8. Finished this build yesterday. Sounds great and fit into a 1590a.

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  9. Verified. This thing is loud as f*ck!

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    1. Sounds like a bad pot. You could also try a larger value pot.

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  11. Hey, where i can find a schematic diagram ?
    Thanks

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    1. http://freestompboxes.org/viewtopic.php?f=1&t=26977&p=255671&hilit=acapulco+gold&#p255671

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    2. Thank you.
      The author says that it is not quite sure in the circuit ...

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  12. Is that a .1 microfarad cap?
    This will be my first pedal build and have most of the components already from amp repairs, minus the amplifiers which I will have to get from China lol.
    I was gonna buy this pedal but why when I can build it for $20. =P
    Cheers

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    1. I think the negative side indicator is throwing you. Those are 1µ caps. (A .1µ cap would be 100n FYI)

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    2. Ah that is a "-" sign, gotcha!
      The local electronics store had what I needed so I will get started on this here.
      You have 3 pots on this schematic?
      I have 250k pots, no 100s I do not think.

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    3. Alsdo, that 4007 is a diode I assume?

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    4. Ah shit...I didn't grab the sockets for the 386's..FML.
      I suppose I could just solder them direct.

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    5. You can probably get away with 250k pots, or you can put a resistor (something in the neighborhood of 160k) in parallel with lugs 2 and 3. And the 4001 is a polarity protection diode.

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    6. Thanks man.
      I am getting some weird stuff happening.
      I made the 2 knob version you posted here but I only connected volume 1 out of the 2 (just to test it) and when I actuate the pedal my volume drops big time...it becomes quite fuzzy for sure but very quiet.
      If I touch the wire to the additional volume pot that is supposed to have a 1M pot on it, the volume bumps up a bit but nothing significant.
      I am just not sure where to connect the second volume pot to on the foot switch and also I had no 68k resistors so I used a 100k.
      I suppose I should use a rule of thumb lower resistance vs more?

      I used the offboard wiring from here:

      https://tagboardeffects.blogspot.ca/201 ... iring.html

      But I see other diagrams showing the FSW being wired up quite differently so perhaps that is where to start lol?
      Cheers for the help!

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    7. There are a lot of different ways to wire up a footswitch and it really just comes down to a matter of personal preference there. Try working to get the one knob version working. The pregain control can be added pretty easily later. The 100k resistor could be the culprit. If you don't want to order some 68k, try wiring two 100k resistors in parallel. That would give you 50k resistance and is a lot closer to the stock value. If that still doesn't sort things out for you, try using an audio probe to find the fault.

      http://www.diystompboxes.com/pedals/debug.html

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    8. OK so I have the Vol 1 & 3 already all wired in so use Vol 1 and unsolder the resistor from the lug on the LM386 then?
      I will wire another 100k in parallel for sure.
      The only other resistor I have on hand is a 33k...I have loads of em for tube amps but not the one I need :\
      This is all new to me man, sorry haha.

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  13. I assume a 100k resistor is safe to use in place of the 68k?

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    1. It's better to use a resistor till 10% lest than value you are looking for. Example: You need a 510k resistor for a Tubescreamer, a 470k works ok.

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  14. where i can find the drilling template for this acapulco gold?

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    1. Since there's only one pot, and it's not even board mounted, I didn't create a drilling template. Feel free to use one of the others as a guide, depending on what size enclosure you plan on using.

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  15. So I soldered the wire that comes from PCB "IN" to G2 (1M pot) and then the G3 to the 3PDT switch.
    I connected G1 to ground.

    The Volume I connected exactly as in version 1, so:
    V3 to PCB "Volume 3"
    V1 to PCB "Volume 1" (is this correct since the V1 is also grounded?)
    V2 to the 3PDT switch

    I tested it and picked up a good radio station haha.
    As soon as I upped the 1M it just started clipping in a rhythmic pattern, no noise from my guitar.
    Everything is properly grounded, wired, soldered, etc as per the schematic so no clue what is up...perhaps I should not be trying to make pedals :(

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  17. Hello, I have a question tha might sound silly. What does "Volume 2 to Out" mean? Where is the out? In the 3pdt? Thank you...

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    1. start from version 1 of the pedal, imagine to have it all wired up in front of you
      The wire that comes from 3PDT switch and goes to PCB "IN" needs to be desoldered from the PCB and soldered it to G3.
      Run a new wire from G2 to PCB "IN"
      connect G1 to ground (well, ok, to V1)

      now the Volume
      it's connected exactly as in version 1, so:
      V3 to PCB "Volume 3"
      V1 to PCB "Volume 1"
      V2 to the 3PDT switch

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    3. I get it now, but why should I do this?

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  18. Just finished mine, having some issues. The volume is unusually low, and there's a lot of hissing. The distortion also sounds a bit "fart-y" for lack of a better word. All polarized components are oriented correctly, and best I can tell all my connections are clean. Any advice?

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    1. What kind of 386 chips are you using? Originals use JRC386Ds

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    2. For sure you have something messed up, this is loud as hell

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    4. Scratch that. Built an audio probe and figured it out. First from scratch pedal build a success. Thanks for the layout. Sounds fantastic.

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  19. I found:

    LM386N-4
    LM386N-1
    LM386N-3

    Which is the best one? I really don't knob the difference...

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    1. You actually want the D variant. I believe original units use JRC386Ds.

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    2. JRC386Ds are available through https://www.mammothelectronics.com

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    3. Thanks... the problem is that I'm in Argentina.

      I was reading about, and the D variant is N-1 and N-3.
      The N-4 equivalent is the JRC386BD (+'B').
      When they're in DIP packages, they add the letter D onto the part code.

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    4. Here's some specs
      https://en.wikipedia.org/wiki/LM386

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  20. i accidentally bought a b100k instead of an a100k. would it still work okay?

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    1. Yeah, the sweep of the volume pot will be a little different, but it will still work.

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