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.
First off, congrats Zach, sounds like you are having an awesome/busy year.
ReplyDeleteI 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!
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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ReplyDeleteMine 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?
ReplyDeleteFixed 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).
DeleteI’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.
ReplyDeleteRead 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
ReplyDeleteWell, 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
ReplyDeleteQuestions* lol
DeleteYes. 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
DeleteIn 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.
ReplyDeleteHi 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.
ReplyDeleteYES! 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.
DeleteCool! Good to know.
DeleteSweet!!! So, just sit the second IC on top of the first and solder all the legs?
DeleteThommo, yes that is correct. Go easy with the solder or it will be difficult to seat it into the socket.
DeleteGood 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
DeleteI 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!
ReplyDeleteThanks for the discovery! Never heard of this one before. Very cool! I used TL071 because that's all I had on hand. LM741 ordered.
ReplyDeleteI 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
There’s a different schematic out there, which is pretty odd but true to the original. No input or caps and a weird power supply. Schematic provided by an old employee that used to make these, and it matches gut shots on effects database. Mind you the modern adaptation probably has some advantages.
ReplyDeletehttps://vero-p2p.blogspot.com/2020/08/earth-sound-research-graphic-fuzz-vero.html?m=1
I solved the constant whine by throwing a small klon buffer infront of the effect. However, it changes the sound.
ReplyDeleteI didn't feel like the filter did much so I tried a 1M resistor as a jumper between where the filter outputs go. It worked out pretty well and I played with different amount and went with a 1.5M to get more fuzz. A 810K (iirc) resistor worked well for less fuzz and a bit more treble. Using the resistor it becomes a one knob fuzz. I added a simple tone control to the output and am very happy with the result. It's no longer the same pedal but I could not get over the whine.
I did witht he LM741CN but the loud whine was persent on all settings. Just did the STACK of 2 LM741 and now the whine is only present after 50%.
ReplyDeleteI did the 100k on volume, but it would be ok with a 10k on my opnion.
Tks Zack for the layout.
Been working on it for what feels like a lifetime.All I got for now is a fancy bypass.
ReplyDeleteI'd does absolutely nothing
Anyone has s clue of what could be
So if I use a buffer, a 500K log pot can be used as filter with a 470K resistor in series with it? Correct?
ReplyDeletehi
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ReplyDeleteHi, I attempted this layout, but had much better success with the one drawn by Nicholas Kula (scroll down this link: http://guitar-fx-layouts.42897.x6.nabble.com/earth-sound-research-graphic-fuzz-vero-layout-td19882.html) with the null pot and spst.
ReplyDeleteHow do I solder the output jack it doesn't do anything
ReplyDeleteBuilt this one with 100% vintage components, carbon resistors, a real 741 etc. The squeal is there like the original in the video. This circuit reminds me of the Seppuku Space Fuzz a bit. It's pretty noisey (my resistors prob aren't helping), but there are glimpses of a great sounding fuzz in here. Thank you for posting, love this site!
ReplyDeleteInstead of stacking op-amps, could I redraw the circuit to use a dual op-amp instead and just connect both op-amps together? Or is there something about stacking that makes it different from just doing that?
ReplyDeleteThis may already be known, but earlier this year a former ESR employee posted the schematic at the end of this thread: https://www.diystompboxes.com/smfforum/index.php?topic=83300.20
ReplyDeleteHello. Who know that mod?
ReplyDeletehttps://www.youtube.com/watch?v=DGP_8Txcjf4&
Was able to knock this one out pretty quick. Used a TL071 IC. Initially had the squeal through the entire filter sweep and the fuzz was fairly weak. Placed a buffered pedal before it as mentioned above and now it sounds just like the video. Fun lil box of heavy.
ReplyDeleteI've read a very interesting instruction on the layout based on the original:
ReplyDeleteDO NOT CONNECT THE GROUND TO THE NEGATIVE POLE OF THE POWER SUPPLY
this is like a ground lift, right?
could be influencing the whining... couldn't it?
link: https://vero-p2p.blogspot.com/2020/08/earth-sound-research-graphic-fuzz-vero.html?m=1
The link above uses a different schematic, which uses a different power supply - it's similar, but not the same circuit. Ground is ground on this one.
Deletehey j-pee. That's a different version of the circuit, which uses a different power supply (+/- 4.5V on the opamp rails). Can't make direct comparisons between the two grounds for this reason.
Deletethank you, Andy, for the clarification!
DeleteBuilt with a UA741 and was getting the squeal pretty much the whole filter knob sweep, swapped a few different ICs in with no luck so tonight I decided to try stacking another UA741 on top and soldering the legs as I've seen suggested and it works great now! squeal only happens around 80% as seems normal, makes it much more playable and better than the sounds I was getting with a buffered pedal in front of it. Very responsive to the volume knob with single coils, more versatile than I thought it would be. Thanks Zach
ReplyDeleteThe Gigrig Virtual battery is great for clearing the noise with this pedal.
ReplyDeletejust a note: since the site "guitarfxlayouts.. nabble.com" was moved...
ReplyDeletelet me re-post the URL of tabbycat's layout and the discussion about it:
(note the change t the old one: "238.s1" instead of "42897.x6")
http://guitar-fx-layouts.238.s1.nabble.com/earth-sound-research-graphic-fuzz-vero-layout-td19882.html
Hi folks, someone knows why it works better (without this big howling) with a battery 9 volts ?
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