ESR Graphic Fuzz traced

[peeps]

Hi.  I traced this thing from several pictures and made a layout that works like the original (my trace is drastically different than the DIY layout).  There are only 4 caps and 4 resistors and the + & - of the battery is connected directly to the board.  The filter crosses both the input and output.  The ic is a little fussy with regard to the whine from the filter- tl061 is great, lm741 okay, and ua741 always whines.  
Anywho, I'm happy to help as needed, but I haven't figured out how to post on the main blog from my iPhone.

Cheers,
Peeps

[rocket88]

hey peeps, do you have a vero layout for it? i'm dying to make this thing. did you use the schematic i posted from the diystompbox forum?

[peeps]

I didn't use a schematic- I traced the original board.  I have a vero layout that works.  I can take a picture of a hand-scribbled layout if that helps.

[rocket88]

that would be awesome peeps. as long as i can read it and know where everything goes i'll give it a shot.

[peeps]

[peeps]

Good luck!  Notice the + & - of the battery connected to the board.  

[JaviCAP]

Great, this very evening witll give a try to this layout!

[rocket88]

Thanks peeps. Hhow can I add a LED, and stomp switch to this? I take it I cant use this  can I

[rocket88]

or add a power jack.

[JaviCAP]

Yeah, it works! Pity I just have UA741 and whimes all time, but the tone is the same of the demos. Lets see I I get tomorrow some TL061!

Thanks a lot!

[GoranP]

peeps wrote

Anywho, I'm happy to help as needed, but I haven't figured out how to post on the main blog from my iPhone.

I had this problem for ages but the solution is really simple (if you are using google account at least, haven't tried any of the other options). Have another page opened and log into your google account. Apparently Safari on ios also uses cookies and that'll get your comment posted.

[JaviCAP]

Still looking the reason why with an UA714 squeals and with a LM741 does not... any idea? Both datasheets look exactly the same....

[rocket88]

javicap, how did you wire the stomp switch? did you add a jack or is it just 9v battery only?

[JaviCAP]

I've not boxed it yet, nor put the 3pdt or the dc jack. Just a bare circuit tryout in  the same way that I always do before building the stompbox and the offboard final wiring of any pedal.

But there's no problem, the fact is that the real ground row has to be isolated, or at least, not directly connected to the power supply, as appears on the layout

So:

Led: Upper row has plenty of room to place there the led resistor. Led cathode I bet that goes to the ground row. If doesn't work, to the -9v tow.

DC.Jack: Just wire it like in any other pedal, but the groung lug goes to the  -9v hole instead of the ground row.

BR

[GoranP]

JaviCAP wrote

But there's no problem, the fact is that the real ground row has to be isolated, or at least, not directly connected to the power supply

Would you mind elaborating on this? Vero ground row is not to be connected directly to the power supply ground?

[peeps]

Thanks for verifying my first posted layout!  For the whine you can add series resistance to the filter/freq pot.  I personally prefer the LM741, which almost whines and causes a cool glassy effect.  TL061 is a close second.  Enjoy.

[rocket88]

Peeps, can you elaborate about the 3PDT switch and LED that Javicap talked about. I want to make this tonight, I'm way to excited to make it. lol

[peeps]

FYI, I started a thread at FSB for this.  I forgot to note that Vol is 10k, Filter(Freq) is 1M, & output is from Vol 2.

[JaviCAP]

You're welcome :) Great layout, i'll try to get a LM741 or a TL061, i have a bunch of UA741, and seems they don't work for this circuit.

Goram, if you take a look to the layout, you can see that the negative wire from the battery (or the power supply) is connected to -VCC of the opamp and goes to groung row trough a 10k resistor and a 100nf cap, but not directly as you usually do on most of the circuits you build

In fact, my dmm reads -4.54 volts on IC pin 4 (-VCC) instead of the 0v, and pin 3 (In+) is grounded (0V), so this circuit is built in a very unusual way.

BR

[JaviCAP]

Yeah, I used 10k and 1M, both linear in this build.

BR