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, August 24, 2015

EarthQuaker Devices Bit Commander

The Bit Commander is an synth/octave effect that's all analog. It creates square wave synth tones across 4 octaves (2 up, 2 down) and it's capable of creating a wide range of sounds. The octave down effect is generated from the ICs, while the octave up comes from the 4024 and transformer (kind of like an Octavia). From EQD:

Like all analog octave effects, there are some basic rules to follow that will get you the most enjoyment from your Bit Commander. Use the neck pickup and play single notes. The best tracking occurs from the 7th fret up on all the strings. Below the 7th will still track but there will be occasional glitches and stutters. The lower the note, the harder it is for the Bit Commander to register. The use of Bass and lower registers on keyboards will yield unexpected, sometimes pleasing, sometimes disgusting results. These are not mistakes or flaws, it is the nature of analog octaves.




37 comments:

  1. Hello, I have made 2 times this pedal and it does not work, you can check if everything is correct. Thank you for your time and your work!

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    1. I left out one connection, but it's an easy fix. Just put a jumper from pin 6 of the TL072 to the far side of the 220k resistor that connects to pin 7. Hopefully that makes sense... I'm updated the layout now.

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  2. If anyone finds a good source for these transformers let us know. Mouser charges $34 postage to Australia.

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  3. Hello again! Do you think well this transformer?
    https://shop.strato.com/epages/62070367.sf/secc7e9935701/?ObjectPath=/Shops/62070367/Products/TRA-42TM011

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  4. This layout does not work, there is no any potentiometer which work well, they do nothing, only works on volume, sorry.

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  5. Can anyone confirm this layout works?

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  6. Hello, pin 2 cd4024 must be grounded, I've built this as their layout and did not work ... watch this layout (http://tagboardeffects.blogspot.com.es/2015/09/earthquaker- devices-bit-commander.html) and found the fault.
    Thank you very much for your page and effort.
    Juanteleca. (Spain)

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    1. pin 2 connected to ground works

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    2. Awesome! I've updated the layout with pin 2 of the 4024 to ground. Thanks for helping sort that out.

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  7. with this last arrangement have been all fixed, works perfectly, this layout is fully verified!

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  8. Hi,
    Nice layout.
    Thank you.
    Could you confirm that audio output is wired on Volume 2 ?

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  9. Hi, so as I understand the posted image of pcb layout is corrected now and is verified? And what's the pcb dimensions? Need to determine zoom scaling for printing it. Sorry for questions I'm almost beginner and thanks in advance.

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    1. Check out the Transfer Image Library tab at the top of the page. It has scaled PDFs of all pcbs on the blog.

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    2. And yes it is correct and verified.

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  10. This comment has been removed by the author.

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  11. Not quite sure what you're asking about...

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  12. Built this one today, and it sounds awesome! Thanks for the great site!

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  13. I can put 42TM022-RC?

    http://pedal-parts.com/ru/home/transformers/42tm022-rc

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    1. This comment has been removed by the author.

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    2. The input is the same (15K ohms), but the output is a little bit higher than the TM011-R.
      The TM011-R has an output of 500ohms and the 42TM022-RC provides 600 ohms output. I really don't know if you can use 42TM022, you decide.

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  14. I can put 42TM022-RC?

    http://pedal-parts.com/ru/home/transformers/42tm022-rc

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  15. First I'd like to thank you for the layout!

    I've just built it, and at first everything worked (I think). Then the upper octave pot stopped responding, and the lower octaves are not ringing out very long, only the dry guitar sound.

    Could you give me some tips, where should I start the troubleshooting?

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  16. Hi, I am new to this page, is there a parts list?

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  17. My local electronics store doesn't carry 2k pots. SO i picked up a 1k pot instead for the UP ONE control.. will this have any adverse effect on the pedal? or can i sub this in, until i find the proper pot?

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    Replies
    1. You can always use a 5k pot with a 3.3k resistor from lug 1 to 3.

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  18. Hi, still relatively a rookie at this. Is the LED connection positive from the 4.7k resistor and then the negative end connects to the ground? or does it connect somewhere else? Sorry. I've been going back and forth on this for awhile.

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    1. Check out the General Layout Notes tab at the top of the page. The negative end gets connected to ground via the footswitch.

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  19. Thanks for the quick response. I checked the general notes at first but I wasn't connecting the dots haha Thanks again

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  20. I wonder, is there a way to mode the 'base' circuit of this pedal so that it doesn't clip? so that that the base knob would mix in a clean version of your tone, rather that a fuzz. would be neat to put that on a toggle switch.

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    Replies
    1. Just tack on a blend circuit like the Split 'n Blend.

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  21. Hi, where can i find the parts list? Thanks

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  22. The lower octaves do not sound long, and break in what the reason?

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  23. This works. i think that majority of issues ppl have is that those 4024's can be a bit iffy. I tried two and they sounded different.

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