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, March 5, 2015

Dwarfcraft Devices Robot Devil

Got a request for the EQD Bit Commander, and while there doesn't seem to be a schematic for it, my search for one lead me to this effect. It's no Bit Commander, but it does do the synth-y octave down thing. The original Robot Devil has the octave switch (which allows you to switch between one octave down and 2 octaves down) as a footswitch. If you go that route, you'll need to use a DPDT if you want LED indication. Or you could just use a toggle SPDT if you want to put it in a 1590B and don't like the idea of having 2 footswitches on such a small box.



Here's how to wire the octave switch as a footswitch with LED indication:


As is, the LED turns on if the sub octave (2 octaves down) is activated. If you wanted, you could use 2 LEDs (or a bi-color LED) to indicate which octave is in effect. Just connect the cathode of one LED to lug 6 (anode to +9v via 2.2k resistor) to indicate 1 octave down. 




12 comments:

  1. Has anyone verified this layout?,Im thinking of making one of these but Id feel happier if there was a schematic to look at..I was thinking it would be cool to have a big muff tone stack on this,I was also thinking about a pre or post circuit fuzz boost with germainium diodes.

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    1. Got the schem from this thread on FSB:

      http://freestompboxes.org/viewtopic.php?f=7&t=18344&hilit=devil+robot

      It hasn't been verified to my knowledge yet.

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  2. Would the +9v go to starve1 or starve2? Thanks.

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    1. Starve 1. Starve 2 goes to the board (not sure why I put "+9v/Starve 2" on the layout drawing...)

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  3. i built this but it sounds way too gated kinda unusable. btw i left out the starve knob but it cant really be the problem i think

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  4. I built it and it works! sounds as the video shows, from a nice distortion to total 8-bit! it's also possible to have a nice distortion with a good octave.
    for me it's verified! thanks for putting the project!

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    1. Does the starve control work well? Like in the video? That is, does the oscillating sound respond when you turn the potentiometer?

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  5. No you're right. I didn't check the starve control very well. It sure does oscillations (more in the first part) but not like the ones in the video and only in some combinations. And octave pot sounds very nice but it doesn't work if the switch is off, in the video he used it even with it off.

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  6. I did it with starve. Verified. Sounds great.

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  7. Verified with starve pot,..I was wondering about the unused pins on both ics,.and I read somewhere that its good practice to ground them,its gives better performance and limits stray noise..anyway this is a good layout thank you!

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  8. Verified with starve pot,..I was wondering about the unused pins on both ics,.and I read somewhere that its good practice to ground them,its gives better performance and limits stray noise..anyway this is a good layout thank you!

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  9. Oh and for anyone confused,9v goes to pin 3 of starve,pin 2 to board.. pin 1 should be left unused!

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