Tuesday, 22 January 2013

DeArmond Square Wave Distortion Generator

Now this one is quite a mystery to me. Analogguru's schematic matches the gutshot at the effectsdatabase, yet the demo suggests something quite different from your average Dist+/250 clone. Schematic states that the pot values are guesses, but there are clone build reports around the web.. So. However it may be. Here it is. The Almighty DeArmond Square Wave Distortion Generator.




18 comments:

  1. Didn't have any luck with this one last night, but I had a few Margaritas before starting. I'll recheck the connections tomorrow morning.

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  2. Ok, you can tag it. I had to stick 1N4148's in there because that's what I had, but this is a mean little machine. Sounds great with a TL071 as well. Thanks for another great layout!

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  3. I breadborded this one and it works fine. Used a TL071. Sounds surprisingly good! It goes on my to-do list.

    The only thing worth mentionen is that the gain pot does a sudden jump at the end of the turn. It should probably be a anti-log taper for best control. :) Thanks for the layout!

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  5. Hmmm, I just took a look at this to compare it to the Vox Zoom Distortion I did a few weeks back and I'm not sure it's right. I build it and it refused to fire up, I had a look at the schematic and it looks like there was a 1M resistor and a 1uf cap missing. I put the 1uf in between the bottom two rows on the left hand side (where it is on the vox) and put a 1M resistor in from pin 3 of the op amp going to the second row from the bottom and it fired up first time. What do you think guys?

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    1. Seems like you are correct. Really weird.

      There's nothing coming of from vref strip.. I'll fix it...
      +m

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    2. Thanks Madferret! I also tagged it...
      +m

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    3. Hey don't thank me yet because I actually meant 'right hand side' when I was talking about the 1uf cap, it should go to ground. Sorry, my bad. I had it from the end of the 1M going to ground. 32 years old and I still can't tell left from right eh?

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    4. When y'all get the kinks worked out, I'll build the updated version and compare the sound to the original layout. I'm not sure how I got the original to work if there were components missing. :) I added a simple tone control to it as well because my amp can get pretty bright with my Tele.

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    5. Funny. I'm the same age :D

      The formerly missing 1µ is filter cap for vref and i placed it wrong :) fixing it right now..
      +m

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    6. Who'd have thought it? The thirties must be the pedal building years :D

      The layout looks just like I made it hitokirimnb, I play a tele with a Fender Blues Junior which tends to be quite bright and I can tell you that this layout sounds very nice and fat so it should be perfect for you.

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    7. Thanks! And I'm also in my thirties.

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  6. I have a 1uf ceramic capacitor. that will work instead of the 1uf electrolytic capacitor right?

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    1. Yes no problem. In fact I just stocked up with 500 x 1u multilayer ceramic caps for that very same purpose, to avoid electrolytics.

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  7. I'm kind of shocked at how damn good this little thing sounds. I built this on a lark because I was bored and it's so small and simple and I had some Vero bits left over.

    I tested it out with a les paul double cut with a Mullinax "Oh, Salvation" bridge pickup (http://www.mullinaxguitars.com/products.php), so I can tell you that solid-body mahogany + p-90 pickup through this pedal sounds BAD ASS.

    I used ceramic 1uf caps, 1N34 diodes, and the nastiest looking little "found in the dusty corner of the bag" 15pf ceramic disk capacitor I've ever dared solder onto a board. I socketed the diodes in case I wanted to experiment some.

    Any suggestions on other diodes that would sound noticeably different while still sounding good? I'd mess with it now, but it's already 2:30am here and I gotta be up for work in 3 hours.

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  8. I was going off an earlier layout of this that I printed out which didn't have the 1uf cap at the bottom and the extra 1m resistor coming off of pin 3. the extra 1uf was no problem, but I had to put the extra 1m at the let edge of the layout left next to that 10k resistor. I haven't put it all together yet, but I assume this shouldn't be a problem right?

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  9. This one definitely needs a C500k pot for intensity.

    A500k gives you 1-8 mostly nothing and then SHOOOOP! whereas the anti-log pot gives a nice smooth range of distortion. I didn't try a Linear as the anti-log seems to worked perfectly.

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  10. Like this one. Get some really nice sounds with this one and seems to blend well with most other pedals. I used OA90s for the Ge diodes and they give a really nice creamy sustain. Another recommend build from me.
    Mark and Miro I bow to your knowledge and this site, just love it. Think the wife might be getting a bit pissed off with my obsession though need to spend a day with the family tomorrow. Maybe sneak in a quick one in the morning. God it sounds like I am having an affair, ha.

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