ESR Graphic Fuzz traced

[rocket88]

JaviCap, can you post a drawing of how to do it. I hate to admit it, but I'm still confused a little bit. It's my first build like this and need all the help I can get.

[rocket88]

i think i figured out how to do the wiring for the switch, but what i dont get is how to isolate the ground on the board. i've seen two different wiring options from beavis audio. one has 2 grounds on the board, each ground goes to a different jack, seen here. is this what should be done for this circuit? the other shows one ground on the board, and is common with the dc jack, seen here which i know should not be done. i have everything ready to go and want to get it in the box and start playing with it, very excited.

[GoranP]

rocket88 wrote

 the other shows one ground on the board, and is common with the dc jack, seen here which i know should not be done.

I may be a bit thick (and am definitely not helping with your switching question) but why is it that you think the board ground shouldn't be connected to the dc jack ground?

If you look, Mark's diagram shows them connected...
http://tagboardeffects.blogspot.com/2012/02/offboard-wiring.html

I'm quite sure the two ground points on the Beavis's board are connected internally and are on the same potential.

[rocket88]

maybe i'm missing something when reading what JaviCap wrote. He said <quote author="GoranP">

JaviCap wrote

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

if i understand it correctly the ground on the board and the ground for the power source, ie: dc jack or battery, can not be connected. on the offboard diagram the ground is not only connected to the dc jack, but also to the input/output jacks. isn't the only thing available for grounding the box itself, which is why the grounds go to the jacks? this is the reason for my confusion as to how to wire it correctly.

[JaviCAP]

Rocket,

No prob. The only difference is that when you wire the DC jack in nearly every pedal,, you wire the jack's ground to the board's ground row.

With this effect you have to wire the jack's ground to the row where Peeps show -9v (black wire of battery clip).

I'm afraid that with this effect, the usual circuit cut with the stereo input jack cannot be done, because if you do it so, the ground (0v) would go to the real ground row and not to where it shoud. If I'm not wrong, this pedal was designed to work only with battery, no power supply.

BR

[GoranP]

OK Rocket, I thought you were speaking in general terms.

In normal circumstances, Mark's offboard diagram is the way to go, as all grounds need to be connected.

[rocket88]

Thanks Javi. I get what you're saying, since the jack is plastic it will be shielded from the chassis, but where do I connect the ground and the switch. I'm confused since it doesnt match up with the offboard posted by mark here.

[rocket88]

peeps. i got the pedal working, but it seems that the volume output is lower then i thought. the sound is perfect, but when i turn the pedal on the volume drops to like 1/2 of what the clean volume is. is this how the pedal is, or do you have any ideal how to correct it.

[peeps]

Rocket- I didn't get a volume drop.  In fact, part of the fun is rolling back the guitar volume knob.  I'd check all the component values and look for micro solder bridges.  Good luck.

[rocket88]

I checked between all the lines, and there's no extra bridges. I used 10k carbon resistors and .1uF ceramic discs just like the original. I know I had a grounding issue before because the pedal didnt work, just barely came through, so I cleaned out the jack holes so there could be a better connection, and boom it worked. Do I need to do the same for the stomp switch hole? Also, I put an LED onto the switch, but can't figure out where to attach it to make it turn on with the pedal. It doesn't go on when attached to 9V or -9V.

[rocket88]

Anyone else try this? I made it got it to work, and its perfect. I just changed the volume pot to 100k to increase volume control. Only thing I haven't figured out is how to add an LED and DC jack. Anyone got any ideas?

[KT]

If you want to daisy chain this (and not use a battery), I think you can use this: http://tagboardeffects.blogspot.be/2012/05/negative-voltage-inverter.html 
Or am I wrong? But still I wouldn't know if you have to ground your your jacks and Graphic Fuzz board to the dc jack or to the voltage inverter ground

[KT]

http://www.sabrotone.com/?attachment_id=523

Or maybe this is the easiest solution.

[john]

Oh nice. I didn't realize you could use a charge pump for this type of pedal. i take it that i could just wire the jack and battery snap like normal, just attach it to this daughterboard.

[KT]

well I haven't tried it yet. It's still not totally clear for me.

[john]

kt, whats not totally clear?

[KT]

If I would use the charge pump, then I can ground everything like I would normally do. Or is there still a difference except for the -9/+9

[KT]

So how do i have to wire it when i don't want to use a battery. And instead a charge pump

[john]

If you're using the charge pump you wire it like normal from the daughterboard with the charge pump. I'd use the layout from Harold, the -9V goes to the -9V on the main board, +9V on the right goes to the +9V on the main board, +9V on the left goes to the +9V on the DC jack, and ground to ground. With the ESR it uses the +9V and -9V to supply the one side of the OP Amp with +4.5V and the other with -4.5V, this is why you can't daisy chain it with other pedals or ground it to the case.

If you're just going to use a battery, without a DC jack then you would wire the positive lead of the battery to the +9V and the negative side to the -9V. The rest is wired the same, the ground is just not tied to the OP Amp.

[KT]

Ok, but if I use the charge pump, then I'll be able to daisy chain it with other pedals?