Sunday, 12 July 2020

Earth Sound Research Graphic Fuzz


This is one of my favorite bizarre and unique fuzzes of all time. Gnarly, spacey, heavy, and broken. Nothing else sounds like it.

Induction on the forum a long time ago talked about how to make it so you can daisychain this beast, because you couldn't with the original. I found floating around in my files a schematic with the modification, so I figured why not just whip up a board.






19 comments:

  1. First off, congrats Zach, sounds like you are having an awesome/busy year.
    I just finished this build and noticed a few minor errors.. there’s 3 links, and also only 10 vertical rows. Also the lower left cap is shown as polarized electrolytic. Not sure if it’s supposed to be 100uf, or of it is 100nf can I use a bipolar film cap?

    My filter seems to be working like the video except when I have it wide open. The vid shows super gnarly, balls out fuzz, but I’m getting a kind of anemic, asymmetrical sound. Probably something on my end as I’ve been up for 20 hours and should just look at it with fresh eyes. Thanks for this upload, as well as the other Recent ones, much appreciated!

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    1. 100uF polarize and you’re spot on with the links and size. I made a bunch of changes and must have forgot to make the corrections. Full CCW should be really gnarly and fuzzy, full CW it will thin out a lot and you should get that siren affect. I’ll take a look at it and check for errors. Will upload the corrected one soon. Cheers man.

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  3. Mine sounds about right but I'm getting a constant tone when not playing that varies with the filter - I can kind of hear this on the video but mine seems to be louder, anyone else?

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    1. Fixed with a new IC (CA3130) - I only had one 741 so I assume I just had a bad IC - it still whines as the filter nears fully CW, but I assume that's as designed, so I'd say this is verified (once you correct the cuts/jumpers info).

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  4. I’m also getting the whine, which may be normal. For me, it’s the fuzz tone when filter is all the way down. The demos all sound like a super bright, square wave, grindy fuzz but I’m getting a muddy, rounded fuzz, especially on single notes. I also built the slightly different layout from dirtboxlayouts and it’s the same thing. I tried op07, ca3130, and ca3140 but they don’t seem to change the character much. I think I need to shelf this One for a bit and revisit it after some other builds.

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  5. Read up a bit on this circuit, seems some oscillation is normal. There is a modded layout in the forums too: http://guitar-fx-layouts.42897.x6.nabble.com/earth-sound-research-graphic-fuzz-vero-layout-td19882.html

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  6. Well, if you guys watch the video at around 5:55 I think your answers are answered :D This is not a fault in the layout, the oscillation/whine is in the pedal

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    1. Yes. I should have watched the video before building this, because the high-frequency signal generator that this thing turns into about 50% into that 1M pot is just...not useful. LOL

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  7. In the video, is the performer also varying the fuzz level with the guitar's volume knob? Otherwise I find it hard to work out what the relationship is between the knobs and the different sounds. Unless he/she is in some places demonstrating a clean tone that also sounds kind of filtered.



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  8. Hi everyone, Just wanted to share my results with this circuit. 1st off Thanks to Zack for the layout! Well after watching the video and a few others, I read threw the following thread https://www.freestompboxes.org/viewtopic.php?f=19&t=22197&sid=c3d005d7f1f0e2242743f35abdf0727e and http://guitar-fx-layouts.42897.x6.nabble.com/earth-sound-research-graphic-fuzz-vero-layout-td19882.html. I was curious so I built Zack's layout. And I got that loud whine threw the full sweep of the filter using a UA741. The whine was only when the circuit was at idle, when playing it was gone. Tried LM301, OP07, CA3130, TL061 and TL071. All worked but really lacked definition, sounded dull or lacking something. I tried all the mods mentioned in the forum thread but most left the filter non-functional. So I put the ciruit on the side and went on to other things. Last night the thought of stacking the ic popped into my mind so I gave it a try stacking a pair of UA741. Low and behold the constant whine is gone, filter works like in the video and whines after 50 percent CW. Best part is that elusive fuzz tone with the filter full CCW is there unhindered. So my build is all back to the way Zack's Layout is posted. Only mod is I'm using a A10K pot for the level because the original schematics show a 10k and I was curious. That and the stacking of the pair of 741. It's been really fun trying all the mods and stuff. So I would say this one is verified because it does work and it sounds just like the video demo. I have no idea why stacking the 741 eliminated the constant whine but it does and I am happy with how it sounds.

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    1. YES! As I mentioned in previous posts, it wasn’t quite right. All the knobs worked and it fuzzed but kinda sounded like weak ass. I tried stacking op amps and it’s alive now. It’s Raunchy and in your face like shown in the vids although mine still has a pretty mean squeal.

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    2. Sweet!!! So, just sit the second IC on top of the first and solder all the legs?

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    3. Thommo, yes that is correct. Go easy with the solder or it will be difficult to seat it into the socket.

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    4. Good information I think I might try adding this to my stable. As far as some squealing, have you tried bending some of the capacitors away from other parts, and what about using shielded input and output wire with the shield grounded at one side, and floating open on the other end, doesn"t matter which end

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  9. I built the version from the forum with the null offset. Originally used the UA741CP and had a lot of squealing throughout the range of the filter pot. Swapped it out for a LM741CN which solves this. In the far upper ranges of the filter the squealing comes back, but I guess this is what it is supposed to do. Nice sounding fuzz though!

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  10. Thanks for the discovery! Never heard of this one before. Very cool! I used TL071 because that's all I had on hand. LM741 ordered.
    I almost abandoned because of the squeal (even tried the stacked opamps trick), but then I remembered that this is often cured by placing a buffer in front. My Boss TU-2 did the trick! Maybe I'll try to jam one of these in there eventually: http://tagboardeffects.blogspot.com/2014/08/buffers.html

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