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.



91 comments:

  1. the new pot, what would be?
    master?

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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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    1. This comment has been removed by the author.

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    2. Late comment for anyone interested : The difference is the 4.7nf cap is moved one hole left if you use the reverse side schematic.

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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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  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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    2. Thanks, I'll try both options.

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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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    5. Hi I have the same problem, how did you fixed it?
      thanks.

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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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    5. Probably a little late to the party here, so if I use an LM386N-3 I'm ok?

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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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  21. Any idea how to mod the tone of this to darken it a bit? I'm new to modding, so go easy on me. Thanks.

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    1. Start with increasing the value of some of the caps in the audio path. I'd start with the 2, 1uF caps and the 4.7nF cap.

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  22. hi, i'm new on this...1º can't figured out if "acapulco" has one knob, why the pcb has volume 1 volume, 2 and volume 3... i do understand the v2 is a way to replace the guitar volume, but what about v3... and 2º, is a two side PCB? i mean should i do conections up and down the pcb? maybe im too new to figured out the pcb conection, sorry about that.

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  23. Like some others said, mine is really buzzy and it squeals as i turn the volume up. Havent try to box it yet, it just lies on my table. Does this pedal (as it is so loud) have some special requirements for grounding? I have grounded everything to output sleeve. Also, I used lm386n1. Because this is a simple pedal i soldered it before doing breadboard but i guess i will try it with same parts to exclude soldering mistake

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    1. "half" boxed it (wires not soldered and pcb out of the box) according to your diagram and it is definitely better :)

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  24. I did, but I used a 1k pot, because 100k was very, very high. E 1k is already quite high kkkk

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  25. Hola! Algún reemplazo para los IC's?

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  26. Greetings from Denmark

    I’ve built this on PCB but I’m having a lot of problems with it.
    As soon as I power it, voltage in my power supply drops at least 3-4 V and there is a horrible noise in my amp...
    It’s a static popping and no guitar sound comes through at all.
    What could be the problem
    I’ve tested the lm386 by building at amplifier on breadboard and it works fine until I jumper pin 1 and 8. Then the popping begins unless I put in a gain controle, then nothing
    Even at max gain there is no popping...

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  27. Im an EE student and get the materials from the uni store for cheap. I built this with two M54AV LM386N-3. The pedal is very noisy (lots of hiss, some 60hz too) and WAY too loud, even on the lowest volume I get quite a bit more than unity, and the effect is almost a gating fuzz. I rolled off nearly all the volume from the guitar and got some very decent sound, and could get good Distortion and fuzz with a slight increase. Also, the noise tends to go away after I start playing, and comes right back a little after the note decays.
    How do I deal with the noise ? I looked for grounding issues but it all seems to be wired properly. I still haven't put it in an aluminum chassis, so I thought that might solve it.
    I assume the 1M mod will help with controlling the fuzz/distortion ?
    Thanks!

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  28. It works, the drawing is good. I built a few pedals from the drawings here. Thanks for them.

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  29. It works perfect¡ After building it I wasn't able to work around the massive and brutal volume+gain combo the 100k pot had, so I decided to experiment with a resistor between the output cap and the pot itself. 33k ohms seemed to do nothing, 100k ohms worked a little bit better but 330k ohms (orange, orange, yellow) was the best for taming this magnificent beast. Now I can set the main pot as "gain" sort of and work around the volume of my guitar. I have a complete palette of gain ranging from devastating high gain fuzz full blast until decent overdrive with grit in the notch 1 or 2 of my guitar volume knob. Thanks a lot for your awesome work¡ you layouts are sick cool¡¡¡¡

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  30. Hello, This is the first pedal that I`m building and I need some help with off board wiring diagram to connect volume output to 3pdt and tham to jack.
    Theres some off wire diagram for this pedal?
    Thanks!

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  31. so i have everything wired up, bypass works, effect works great, wiring for the 3pdt is all up to spec per the site, and all the wiring is double checked, but i'm getting an unusual buzz. the buzz is coming from the input, specifically the 10uf cap at the input, as if its not grounded, if i touch that cap, and only that cap, the buzz intensifies, if i tap it with a chopstick or any lead coming from it, its microphonic. could it just be a bad cap?

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    1. edit: changed 10uf cap, issue still persists. is this just normal?

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  32. Built this with the added Gain pot and it works awesome. One thing I will say is that I was getting some squealing from it when the volume was maxed, I noticed that some of my wires were crossing and when I separated them the noise went away so be careful with your wires on this one.
    Also I have been messing around with adding a tone stack, so far when i max the volume it renders the tone dial useless but when I back it off the tone dial works, any suggestions on how to wire one in correctly? I have used the AMZ and the BMP, the AMZ is really great ofr subtle tone changes and the BMP is awesome if you really want to change it, way more treble with the BMP.
    Thanks

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  33. Built this one, just did old school point-to-point on a breadboard. Actually have built 2 now and these sound AMAZING. Side-by-side with a MXR Distorion III and/or a good ol' Boss DS-1, this sounds way better, hands down. Thank you.

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  34. I need sub for 386 ic, any else verified? I have built it, great sound but so dirty, I try filter it with paralel 2k2 R n 104 cap to out layout

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  35. Hi all!

    I buit it tonight: this circuit is really useble massive ditortion sound.
    Im used pair of 386-N1, all ok, output signal solid and without any noise.
    Some qustion:
    1) If i add 22nF to output line after 1uF electrolyte cap, i can use pot to full range? (in current shematic only half of it can be used)
    2) I have very hot SeymorDuncan Blackouts humbakers, and can use my guitar volume knob also obly half of range. Where i can put resistor for full range volume? What is resistir value needed?
    3) What happened, if i install one 386-N1 and one 386D there?

    Thank u so much,

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  36. It sounds great but when im not playing it buzzes like a swarm of bees and picks up a radio station. Seems like something was up with the input when i poked around but I cant figure out what it could be I tried different caps and it still sounds like im holding the cable in my hand. Frustrating. I even went out of my way to buy the 386Ds (which do sound different than the 386s tayda sells btw)

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  37. Hi I just wanted to check that the 10uf capacitor at the input of the circuit is the correct polarity? I would think the '-' symbol should be switched to the side leading into the + input of the the op amp. But I could definitely be mistaken. Appreciate your help.

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  38. Verified!!!
    Jun fr Philippines

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  39. Hi, i built this and it's working ok, but the strange thing is that when i engage it, volume decreases a lot, it is a bit strange since anyone is saying that it is so loud... Sound wise is actually good and it doesn't make any strange sound... What could it be? Thanks a lot for your work, this is my first build and without your website I couldn't make it.

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  40. Hi, just came here to say that this was my first build (did it on the breadboard, no vero) and it works like a charm! At first I got a lot of noise when using the LM386N-1 but I managed to buy a few JRC386D (J1018) and the noise was completely gone (mind you, I'm not even in the aluminum box, it's everything on the breadboard)! Thank you for keeping this stuff here, helped me a lot!

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    1. When I used the LM386N-1 and LM386-4 whenever I would palm mute and chug the volume would decrease dramatically. Switched to the JRC386D and the sound decrease disappeared!!!

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