Clarification on Pedal Grounding

[garcho]

Great thread. It's important to walk through things step by step. I think part of what makes this issue confusing for so many people is:

• often, when you do it "wrong", it works just fine
• self-taught tinkerers like myself tend to focus only on voltage and forget that electricity is voltage AND current
• ground vs earth vs shield vs reference vs... but it's all ground?!?! 

[Big Monk]

...i.e. a single connection to the enclosure is shunting rather than conducting current.

I prefer to think of it as the enclosure does not "participate" in the basic operations of the circuit.  Shielding is a "bonus" that the enclosure provides in this configuration, which I like to simply enjoy and take for granted. 

Well said.

Appreciate the input. Now let me go build that power supply filter I've been thinking about all morning...

[amz-fx]

regards, Jack

[Rob Strand]

regards, Jack

Quite a good video but the motive behind it it more about safety and stopping audio geeks doing stupid things.

The part from 17:40 (and some background for that back to 14:52) is probably more useful in terms of understanding mains related  "buzz".

With that in mind you can start to think a bit more about how mains borne noise couples in,
https://www.analog.com/media/en/technical-documentation/application-notes/41727248an_347.pdf

If you can explain why touching the guitar strings decreases the buzz you know you have got the idea.

[sopapo]

I an having difficulties understanding the proper way of doing this, I would like to wiring usin rg keen method, and use shielded input cables I dont need input power switching... But when he says that the audio ground of the input socket has to go to the input"ground of the board, what does mean? To me, the ground of the board is the same for all... has the board layout has be designed in a especial way?
We can do this method to aby board we have? I dont know how to implement this in a 3pdt switching arrangement..
Thanks for all
Best regards

[antonis]

But when he says that the audio ground of the input socket has to go to the input"ground of the board, what does mean?

Simply what R.G. says..

On PCB, there might be many GND points so you have to consider the - not necessarily physically - closer to input GND point..
(e.g. point connected the input pull-down resistor..)

[sopapo]

Ok, thanks Antonis, the pull down thing has put me on track. I understand that is the same for the output...
And the ground connection of the 3pdt is also to the "star" point of the pcb?
The thing that "bug" me a little, is that the point grounds on the pcb are more "spreaded" than the typical wiring with all the grounds on the jack, but I suppose that in reality its better....

[antonis]

The thing that "bug" me a little, is that the point grounds on the pcb are more "spreaded" than the typical wiring with all the grounds on the jack, but I suppose that in reality its better....

Many ground points on a board serve primarily for in-out wiring convenient connections..
You may see many semi-proffesional PCBs with a number of GND pads more than required bu circuitry design..
There are practical reasons for doing that, like assembling/dismantling a particular enclosure mounted gounded pot without interrupting the whole ground chain..

[sopapo]

Thank you for your answers I thought that was relevant that the grounds have to be on the same spot physically, with little deviation...
The ground of the 3pdt goes to the same point on the board with the  rest of the grounds?
Best regards

[antonis]

The ground of the 3pdt goes to the same point on the board with the  rest of the grounds?

If we're talking about stompbox effects (aka low voltage - low current - small acreage) there is of no interest to discern particular ground points..

e.g. below Black, Blue & Violet wiring paths are completely interchangeable..

[mark2]

Has anybody actually ever had a problem from a ground loop through the enclosure by wiring both the input and output sleeves of non-isolated jacks?

Maybe this is a topic for its own thread?

I see this flavor of ground loop discussed and addressed more than a few times. I've even seen, much to my dismay, pedals with an input or an output jack's sleeve connected to the net ONLY through the enclosure (presumably to address the ground loop "problem"). Woe to the unlucky player whose nut comes loose during a show.

I don't particularly like any isolated jacks I've come across for top mounted 125B's, so I just use ones with metal threads, both of which are securely tied to GND by PCB traces or wires. Sure it's a ground loop, but does it ever actually matter in the real world?

[antonis]

Woe to the unlucky player whose nut comes loose during a show.

[mark2]

Woe to the unlucky player whose nut comes loose during a show.

Unless the loctite gets between the metal and enclosure altogether. But at least then you'd know it before the show.

[GibsonGM]

When I started, I ONCE had a jack loosen up on stage and go "BRRRRRRRRRRRRRRRRRRRRRRRRR".   After that I started grounding both jacks. Never had any single problem with doing it.

[zbt]

ref
https://www.diystompboxes.com/smfforum/index.php?topic=124462.0
https://www.diystompboxes.com/smfforum/index.php?topic=120439.0
https://www.diystompboxes.com/smfforum/index.php?topic=100148.0

my little bug
try using the switch, try potting the volume switch,
I feel the culprit is the battery and switch so I decided not to use inside,
more space, better use the battery outside of a good battery bank maybe that will help?

another bug popped up when trying the bypass switch
if the signal can be passed, why does the ground have to be a detour
so think what if the bypass switch is used as center ground (pin 5) and use shielded wire
depending on the cable, now ground bypass can use copper or via pcb
maybe add a protection diode, filter cap, voltage sag, etc

but now the input and output jacks have to be isolated,
my only advantage is that the 3PDT already locks the washer



now again is it better at input, output, or 3PDT?
has anyone tried this?