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.

Thursday, July 16, 2015

MI Audio Crunch Box

Got several requests for this one. The MI Audio Crunch Box is a versatile distortion box, designed to sound like a cranked Marshall. It's very similar to the Marshall Guv'nor, but with a Rat style tone control. Production models have the Presence control as a trimmer internally, but it makes sense to me to have it externally.




62 comments:

  1. Thank you ver much man, you are the bes! :D

    New Proyect! :D

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  2. Verified!works ok!even the presence knob, i use tl082.

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  3. Build it with TL072 i have trebly and crunch/crisp tone, when i replaced with NE5532 it produced warm tone but still high gain! Thank's for the layout, you're the man!

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  4. Dear friends, sorry for the stupid question. What should I do with volume 2 and 3, and presence 2?
    Thankful.

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    Replies
    1. Connect Presence 2 to Volume 3, and Volume 2 is the Out.

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  5. Someone have the 3pdt wiring ? Or have some ideia about what happens? because i'm trying but, in bypass mode works, when I "turn on the distorition" the pedal dont work.

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    1. There's 3PDT wiring in the General Layout Notes tab.

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  6. I made this model using 3pdt easy wiring, but only the bypass works, and, when I "turn on the distortion" the pedal dont works, do you have some ideia about how can I fix it?

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    1. This is a fairly common problem. I run into fairly frequently myself. It could be an issue with your off board wiring or a problem with the circuit board. Have you checked it over with a multimeter?

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    2. hi there, I faced the same problem here... I already made it twice and I got the same result, no sound at all, while the led indicator was on. it also happened in the bypass mode.
      any idea what was happening to my build?
      also, is there any specific position for the two 5mm leds? its + and - pole perhaps?

      thank you man, your site have brighten my days!

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    3. Sounds like an offboard wiring problem, so check all that. As far as diode polarity, the negative side of D1 is on the right, and D2's is on the left. The flat side of an LED indicates the negative (cathode). On all my the pcbs the square pads indicate the negative side of a diode. Hope that helps.

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    4. ah...
      I hardly see the flat side of the led...!
      thank you sir,
      I'll re-wire my led.

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  7. very versatile high gain soooo crunchy and way better than krank dm .... but thats just my opinion
    @dtgehring thanks a lot for the layout

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  8. I accomplished, but the result was the same as Mopheus said at the top of the page. I'll try his solution.
    thanks Bro, you're the man! =D

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  9. I replaced the ic, but I'm having problem with the gain.One doubt: - there's problem if the leds be "high bright" ( I don't know how do you call in english)

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  10. I don't think having high/super bright LEDs would matter too much. But I could be wrong there... Have you tried using different diodes in there? Smaller LEDs, 1N4148s, etc.

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    1. I'll try smaller leds and diodes. I think so strange, the gain don't change, is Always low. The pot is working well. Thanks bro!

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  11. a dumb question... what is meant by B.O.M. ?

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    Replies
    1. bug!
      1M resistor between the 470 ohm and 10K ohm

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  12. am I the only one who attempted to build this one three times using perfboard and failed all of them?
    big lol
    I'll keep on trying for the forth times, fifth times and on till I hear a sound comes out of it. this is my most wanted effect pedal.

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  13. I builded this pedal and works fine, thank for effectslayouts.blogspot.com.br!!!

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  14. DONE!!! FINALLY..!

    MOVING ON TO JHS MORNING GLORY

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    Replies
    1. this is my fifth attempt, and it's worth it.
      thanks to you, brother

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  15. Hi. I builded this and works fine, but sounds a "ploc" when I press the 3pdt. Can you help me? If I put a 1m resistor in the in, can I resolve it? Thanks a lot.

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    1. perhaps it can be solved by soldering a 100k resistor from output to ground.. just like what happened to deep blue delay

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    2. Thanks for the answer. I'll try it.

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  16. Newbie here
    Just want to try simple circuit first
    It works fine. But the distortion is set to max but it sounded like a crunch distortion (yeah i know its crunchbox) but doesn't it suppose to give a high gain dist? I know because I have tried an original CB before way too different than mine. If I lower down my gain knob about 2-3 o'clock theres no distortion at all and leds are not lighting up as I hit my guitar
    Some parts that I use (due to available parts that I have)
    2 100pf monolothic ceramic
    Gain knob - 100kA

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    1. Since you're using a log taper pot (A100k), the control of the gain is only going to be in the last third or so of the pot's turn. If you use a linear taper pot (B100k) the sweep will be more consistent and you'll have more control over the gain. As for the LEDs, in this set up they're being used as clipping diodes, not light sources. So they're not always going to light up.

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    2. Ill try to get some linear pot instead.
      Thank you

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    3. Here's an update on my build. Got a linear pot (B100k) for the gain and you're right i got now a better control on the gain but I still dont get a high gain out of it. Slight/crunch distorted sound from it. Its more of an overdriven kind of sound not a distortion kind of gain. Do I need to get a ceramic caps for the Pf's instead of monolithic? And some of caps were used are wima and polyfilm. Does it matters?
      Thanks

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  17. This comment has been removed by the author.

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  18. Built this and it sounds great! However, it's quite loud, and I'm getting a fair bit of noise with the gain knob at full. Any ideas on what might be causing that?

    Also I noticed there is a missing link in the layout. The layouts on the right show a link between the 1M resistor connection to pin 3 of the IC, but the layouts on the left don't have it.

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  19. Hi, brother I dont have b20k pot for presence. I have a w20k pot, Can I use?

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    1. I have too a b10k. which one work better for presence? w20k or b10k ?

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    2. Try both of them, find one that suit you most. As easy as that

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    3. its used as a single resistor adjustment not a blend . That means you should use the 20k because you can set it up to 20k instead of just 10k. I like it set at about 8k personally but the original version one used just a 10k resistor for that .i would never set it all the way up but its a nice feature especially if you use a fuzz peal before it to get some of the high end back.The presence is nice all the way up to about 14k for my taste . i set it between 7 and 12 k and 8k is the sweet spot with my strat

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  20. Replies
    1. No as the 308 is a single op amp and the 833 is a dual op amp. You can use a TL072, JRC4558, or other dual op amp though.

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    2. Ok, thanks for suggestion, i'll try

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    3. Ok, thanks for suggestion, i'll try

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  21. i'm not find a 20k potentiometer. can i use 50 k ?

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    1. Use the 50k, but solder a 33k resistor across lugs 1 and 3. This will make the pot 20k.

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    2. thanks bro .. you are the best bloggers always answer reader questions .. if I may ask again if i use 50k for replacing 10k does this work?

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    3. You'd have to adjust the value of the parallel resistor. Google parallel resistance. Though the taper might be off since the circuit calls for a rev log 10k. YMMV

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    4. what is your facebook name.. i will send a some picture ..i don't understand how to soldering the resistor place

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  22. Hey Buddy! I'm building the perfboard layout and just caught a mistake. The 1M besides the 470r resistor is going nowhere. In the PCB its right

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  23. how to reduce noise , if I set dist gain knob more than 12'oclock... its noisy

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  24. worked fine, can I reduce volume range? becoz too loud, I cannot set 12'oclock volume from this pedal, its very loud, any remedy?

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    1. try lower value pot for volume. perhaps b10k or b50k
      the noise can't be reduced I guess. hi-gain distortion comes with noise everywhere haha

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  25. Hola en qué tamaño debería imprimir el PCB para transferir ?

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    Replies
    1. Busque en la pestaña Transferir biblioteca de imágenes en la parte superior de la página

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