I just can't get a break! (Bridge grounding help)

[Kess.V]

I just can't seem to get a break. After finding a solution to one problem, I decided to clean up my wiring a little bit (as suggested/insulted by users). Now whenever I touch the bridge pickup (Seymour Duncan Invader) of my guitar, I get a loud buzz (like touching a plain cable plugged into an amp, but not as loud). This leads me to believe that it's a grounding issue. If I touch anything else on the guitar (i.e. the bridge) there is no buzzing. The 60 cycle hum that occurs usually because of my basement's bad electrical work stops when I do. Does anyone know of any solutions to get my bridge pickup to stop buzzing when touched? I've since soldered a wire from the back plate to the back of the push/pull pot and ran copper shielding to make sure it was making contact with the input jack plate.
Wiring schematic I used (I checked and rechecked my wiring and everything appears to be right):


Here's some pics of the wiring, not that it helps any:





Please keep all responses positive and/or constructive. I appreciate/thank you for any response!

 

[Mincer]

Re: I just can't get a break! (Bridge grounding help)

Is there a chance the 2 wires going to the jack are reversed?

 

[KNUCKLHEAD]

Re: I just can't get a break! (Bridge grounding help)

I doubt the Jack is backwards if Only the 1 Pu makes noise . I would Run an Auxilary ground wire to That Pickup . Also - not mentioned here often . I make simple a twisted bare ground Jumper wire and run it to all the main apparatus and attach to it , wherever needed along it like a long Buss . Usually use 3 small wires twisted together , in the gauges of 20 something . In other words , I'm only attaching to a Pot once and the Buss-wire along several places ( I usually twist a few Loops in it in the run - as well ) whenever You add a Ground for Anything ~ just Solder to the common Buss-wire not keep hitting pots and other appar. <-- I have never had one Fault on Any build for the last 20ish years. I do this because I have been an Electrician for 40ish years and some techniques carry over very well to guitar building . Dont let Anyone tell You this isn't a Merited method ~ they would be full of Krap . I NEVER have Ground issues incorporating this Harnessing , unless the apparatus is Faulty ( Pickup, Switch, Pot , etc.. You also need to know how to Solder properly (dont know if U do or not ) avoiding cold joints with proper tinning , dipping Iron in water / Rag dish <--- cleaning the Tip ongoing during the solder job , etc. Also pinch things off where Needed with a Stainless (non-Magnetic) Hemostat /Roach Clip to Disperse heat from the Soldering Iron/gun .

 

[Joey Voltage]

Re: I just can't get a break! (Bridge grounding help)

Do you have a dmm? It would be very easy to test for continuity between the the pickups, all the metal parts, shielding and the return reference.

 

[zionstrat]

Re: I just can't get a break! (Bridge grounding help)

Assuming good joints, I've had to star ground a few complex builds with similar symptoms, ie breaking multiple grounds, but your build is so simple that this seems unlikely.

Definitely agree with JoeyV, a couple of minutes with a dmm is worth 100 words

 

[Hyperborea]

Re: I just can't get a break! (Bridge grounding help)

Actually, if when you touch the bridge the noise stops then the issue isn't the bridge ground. When you touch the bridge and it's grounded then you become grounded and your noise (yes, you are a big antenna of noise) is taken to ground and not injected into the circuit. The bridge isn't the grounding issue you are looking for.

 

[Kess.V]

Re: I just can't get a break! (Bridge grounding help)

Do you have a dmm? It would be very easy to test for continuity between the the pickups, all the metal parts, shielding and the return reference.

I do, and was told on another forum to test the connection from the back plate to the back of the push/pull pot. I got a reading of 0 Ohms, which is what I was told is what it should be. Could you be specific with locations to where is should check the connection? I'm not too great with knowing those things...

 

[Kess.V]

Re: I just can't get a break! (Bridge grounding help)

Actually, if when you touch the bridge the noise stops then the issue isn't the bridge ground. When you touch the bridge and it's grounded then you become grounded and your noise (yes, you are a big antenna of noise) is taken to ground and not injected into the circuit. The bridge isn't the grounding issue you are looking for.

When I touch the bridge pickup the noise actually gets louder.

 

[Joey Voltage]

Re: I just can't get a break! (Bridge grounding help)

I do, and was told on another forum to test the connection from the back plate to the back of the push/pull pot. I got a reading of 0 Ohms, which is what I was told is what it should be. Could you be specific with locations to where is should check the connection? I'm not too great with knowing those things...

So there are a couple of things that stand out to me.

1: Set your dmm to the lowest ohms setting, and touch the red and black probes together. What do you read? it should be ridiculously low, but probably a little higher than 0 ohms. What you read is your short resistance.

2: make sure you have conductivity between all the patches of that copper tape you used and ground. Otherwise it's not doing you any good, you also don't have to have it on the bottom of the base plate of the invader. Since you are using humbuckers, the shielding isn't adding much to noise performance since you already have a very good cmrr with them. You would have to encase the entire humbucker and all the routes for it to really buy you better noise performance, so it's not crucial you keep it.

3: touch your probe to the bridge or block, and the output jack sleeve connection to Make sure your bridge is grounded.

4: check for continuity between all the metal parts - pot casings, switch exterior etc and make sure those are all reading a short to the sleeve connection of the output jack.

5: On another note, Your tone cap also looks like it is shorted to the pot casing. Make sure the side that is connected to the center lug isn't touching the casing.

Let me know how it goes, and we'll take it from there if it's still giving you grief.

 

[Hyperborea]

Re: I just can't get a break! (Bridge grounding help)

When I touch the bridge pickup the noise actually gets louder.

Ah, I see that in your original post. Then it does sound like a bridge grounding issue. You touch the bridge and now the strings are also part of your big antenna of noise.

 

[Kess.V]

Re: I just can't get a break! (Bridge grounding help)

So there are a couple of things that stand out to me.

1: Set your dmm to the lowest ohms setting, and touch the red and black probes together. What do you read? it should be ridiculously low, but probably a little higher than 0 ohms. What you read is your short resistance.

2: make sure you have conductivity between all the patches of that copper tape you used and ground. Otherwise it's not doing you any good, you also don't have to have it on the bottom of the base plate of the invader. Since you are using humbuckers, the shielding isn't adding much to noise performance since you already have a very good cmrr with them. You would have to encase the entire humbucker and all the routes for it to really buy you better noise performance, so it's not crucial you keep it.

3: touch your probe to the bridge or block, and the output jack sleeve connection to Make sure your bridge is grounded.

4: check for continuity between all the metal parts - pot casings, switch exterior etc and make sure those are all reading a short to the sleeve connection of the output jack.

5: On another note, Your tone cap also looks like it is shorted to the pot casing. Make sure the side that is connected to the center lug isn't touching the casing.

Let me know how it goes, and we'll take it from there if it's still giving you grief.

1: Lowest setting I have is 200 ohms, and the short reading was 1.5

2: Conductivity between the copper tape and ground was good. The patches of tape on the back of the pickups have been taken off

3: Bridge and output sleeve got a reading of 2.0/2.3

4: Bridge Pickup to sleeve- 1.5
Tone to sleeve- 1.5
Volume to sleeve- 1.5
Bridge Case to volume- 1.4

5: Tone cap is no longer touching casing

 

[Joey Voltage]

Re: I just can't get a break! (Bridge grounding help)

3: Bridge and output sleeve got a reading of 2.0/2.3

Just to rule out higher resistivity in the metal of the bridge, does this reading change the closer you get to the claw, or wherever the ground wire actually terminates to the bridge? If it doesn't it is very possible you might have a partial break. Also have you tried it since, and observed the noise exactly the same after taking your readings?

Do you have a separate patch cable? One very ghetto trick you can do is plug into your guitar, and amp with one cable then mute the bridge while holding one end of the xtra patch cable putting the tip to the bridge or strings. Take the other end of the cable and touch it to the metal outer sheath of the the one that is plugged into the amp. If conductivity is good enough, this should put your bridge at ground potential.

 

[zionstrat]

Re: I just can't get a break! (Bridge grounding help)

Good trick JV! Always used alligators for same test but they are never long enough.

Interested in hearing resolution.


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