Hello,
I have a general question regarding grounding inside guitar pedal (veroboard).
Let's say I have 8 points who needs to be connected to ground - 3 lugs of 3 different pots, 2 sleeves of jacks, one lug of led and another lug of switch.
I have my main +9v and GND points in the veroboard that I connect to them the DC jack (+ terminal and the GND terminal).
How should I connect them all to ground? if I connect them all to the GND terminal of the dc jack it will be almost impossible connecting so many wires to the same point.
Will it be a better practice to connect each ground point to the other one and so on untill the last one will ne connected to the dc jack GND terminal ? something such as: pot 1 lug 3 ---> pot 2 lug 3 ---> pot 3 lug 1 ---> input jack sleeve ---> minus lug LED ---> ---> sw lug ---> output jack sleeve ---> dc jack GND terminal .
Thanks
That's exactly what you must NOT do or you'll create multiple ground loops..
(each connection between 2 consecutive ground points is added in series on the others so no ground point exhibits exactly the same voltage with the others..)
P.S.
For a simple guitar pedal effect, ignore the above and make ground connections on any convenient point.. :icon_wink:
(also, search for "star ground"..)
Here's how I like to arrange a star ground in a pedal. Take a grounding lug as used in a guitar body, and solder the narrow end of it to the sleeve lead of the input jack. Then use the larger hole (normally where the screw secures the lug to the guitar body) as the star ground point for all the ground wires. Plenty of room. I usually leave these grounds as the last wires to connect. And I use a heat sink on the lug when soldering the ground wires, it takes a while. As a bonus, this makes a handy ground point when metering. Mike
(https://i.postimg.cc/5HgRFP7x/Ground-Lug.jpg) (https://postimg.cc/5HgRFP7x)
Thank you both for making it clearer for me on the subject :)
Edit: will it be a good practice to ground the enclosure as well ?
Yes, you want the enclosure connected to ground, so it will act as a proper shield (screen). The easiest way is to use non-insulated jacks, and make sure there's bare metal around the inside of the jack holes (giggity), not totally covered with paint. With two jack sleeve lugs, that usually enough to connect all ground wires. Nothing wrong with single-point (star) grounding, but it isn't necessary.
For non-insulated jacks the method used by Boss is fine,
http://www.freeinfosociety.com/media/images/1274.gif
Their "single point" is the input socket.
The output socket doesn't have a ground wire it picks up the ground through the chassis.
If you wanted to use shielded wire for the output socket you can just connect one end of the shield.
Using star washers on the socket can help the reliability of the connection.
It's better if you use insulated power inlets then wire the ground back to the input socket, as Boss have done.
Use an inner toothed, lock washers inside the enclosure on your non-insulated jacks and they should stay tight and will ensure an excellent conductive path from the jack to the enclosure.
(https://d10b75yp86lc36.cloudfront.net/Monotaro3/pi/full/mono41972524-160406-02.jpg)
dave
I've been known to occasionally use a 1×N piece of veroboard when I need to ground several things together:
(https://i.imgur.com/Bi4Swzfl.jpg)
Quote from: EBK on June 24, 2020, 12:42:35 PM
(https://i.imgur.com/Bi4Swzfl.jpg)
That's fantastic!
Quote from: ElectricDruid on June 24, 2020, 04:48:50 PM
That's fantastic!
Just imagine it freely hanging around with diode anodes or copper side of board inside enclosure.. :icon_eek:
Quote from: antonis on June 24, 2020, 04:55:45 PM
Quote from: ElectricDruid on June 24, 2020, 04:48:50 PM
That's fantastic!
Just imagine it freely hanging around with diode anodes or copper side of board inside enclosure.. :icon_eek:
Heat shrink tubing or gaffers tape if I'm feeling lazy eliminates that problem, as far as I'm concerned. Sometimes I'll glue it to the enclosure wall near the DC jack. The one in the photo is a pre-boxing prototype, where it it can safely practice social distancing.
Yeah, I'd assumed you'd fold the wires over sideways to make it into a little tube and then put some heat shrink over it.
A bit of hot glue on the enclosure, and your little miscellaneous bits o' perf/vero are safely sorted. I have done that with the AMZ pop-free LED circuit, ought to work just as well with a star grounding point. Alternatively, the old Guitarnutz star grounding scheme uses, IIRC, a round washer as a star grounding point. Again, a bit of electrical tape or shrink tubing, and there are no worries of shorting anything out.
Quote from: Ben N on June 25, 2020, 09:08:04 AM
a round washer as a star grounding point.
Which then becomes its own ground loop. Not that it matters.
Quote from: willienillie on June 25, 2020, 02:46:19 PM
Which then becomes its own ground loop.
Why? If there is a single wire from the washer to each of: circuit board ground, the negative lug of the power jack, and either, but not both, of the signal jacks, where do you see any loop? There is only a single path to ground from anywhere in the pedal.
Quote from: Ben N on June 25, 2020, 05:58:39 PM
where do you see any loop?
The round washer is a loop.
Quote from: willienillie on June 25, 2020, 10:49:23 PM
The round washer is a loop.
Not precisely.. :icon_wink:
(it indeed is a loop in the geometrical viewpoint but it doesn't add any resistance between two distinct ground wires 'cause is the point on which END UP ALL wires..)
(https://i.imgur.com/K6rbQQr.gif)