Magnetic hum/buzz from my guitar.

[Lavabug]

Ever since I started doing pickup swaps on my Charvel I've always gotten a slight buzz in the background whenever I let go of the bridge/strings, somehow the circuit isn't properly grounded but I've tried a billion different ways of wiring it and the hum never goes away completely. Recently I wired it up like this:





(1 humbucker, 1 single coil)

By hooking up all grounds to the switch, then to the pot(I've tried 3 different ones), then to the jack I got much less ground buzz, but it's still there, and whenever I lower my volume knob below 100% it dials in a static noise with radio stations faintly audible in the background. Wtf.



I even tried using copper foil in the electronics and pickup cavity to make a Farday cage(insulation against radio waves when grounded), but I recently found out that if you don't fold over the ends of the copper foil so the sticky part makes contact, it won't work as only the sticky side of the tape is conductive, so basically I did it wrong. Ordered some more copper tape and solder(I wasted a whole tube ) and am going to try this again.



If that doesn't work I might try hooking up a pickup from the pot straight to the jack with no switch, maybe the switch is fucked, but I'm not sure something as simple as a bad switch is going to pickup radio stations. I did all of the wiring on my Ironbird and it never gets any radio signals(and I've tried its pots on my Charvel, so the only thing different between the 2 is the pickups and the switch(an EMG switch)).

[L Macey]

You've got a bad earth somewhere if it's buzzing when you let go of the strings. Make sure the ground is connected inside the pickups (by taking them apart if necessary) and maybe replace some of the earth leads if they look crappy. Resolder any suspect joints.



I'm not sure why your switch has a ground on it..

[Lavabug]

[quote name="L Macey"]You've got a bad earth somewhere if it's buzzing when you let go of the strings. Make sure the ground is connected inside the pickups (by taking them apart if necessary) and maybe replace some of the earth leads if they look crappy. Resolder any suspect joints.



I'm not sure why your switch has a ground on it..[/quote]

Thanks man. Most of the wiring diagrams I've seen from SD and Dimarzio show the switch being grounded, it has a lug on the opposite side of the pickup lead lugs that seems to be for that purpose. Am I not supposed to ground it? I think I tried that once and I got even more noise.



I managed to fix the problem mostly, shielded the whole guitar internally(it's connected to the ground too) and got new wire and resoldered all the connections a lot better. The buzz is now generally nonexistent or extremely faint when I let go of the strings, but now I've got another problem: whenever I roll the volume knob down it dials in a very LOUD static noise that persists unless I roll the pot back up to 100% or 0%, anywhere in between gives me a static noise that is as loud as the guitar signal, so it's impossible to make use of the volume knob for cleans.



I've tried different pots(quality ones btw) and it's not working for me. Any ideas?



Btw how can I check if the pickup's earth lead is fine without cutting the wire/pickup open? Can I check continuity between the earth lead and one of the hex screws or the back plate of the pickup?

[L Macey]

You can check continuity the way your describe yeah, the ground should be soldered to the back plate of the pickup.



Are you using EMGS btw? Does this behaviour happen for all the pickups in the guitar or just one?

[Lavabug]

[quote name="L Macey"]You can check continuity the way your describe yeah, the ground should be soldered to the back plate of the pickup.



Are you using EMGS btw? Does this behaviour happen for all the pickups in the guitar or just one?[/quote]

Nope, I'm using a Dimarzio Steve's Special in the bridge and a Jackson single coil in the neck(it's a Charvel), and yeah the static noise happens with both pickups. The problem also happened when I had a tonezone in this same guitar.



I'll try checking continuity that way, I'll update later. If it so happens that there's no continuity, should I solder a wire from the back plate of the pickup to the common ground(like the bare wire normally is)? It would suck if i had to cut open the pickup to check if it's connected.

[L Macey]

Yeah that'd work I think. However if both pickups are making the noise, a single pickup is unlikely to be the problem. As annoying as it is i'd suggest trying the pickups in another guitar, then placing ALL the electronics in your charvel one at a time, as this sounds like a real mystery.