Disagreement with my tech : very simple question : is HB ground wiring needed?

G

greekdude

New member
Yesterday for no reason, (yes in Athens you have to have a reason) I paid the tech a visit to his shop, as I was around the block spying on my Son and his behavior (long story).

The tech's work is perfect, however we got into a debate . He claims that humbuckers dont need no bridge grounding. When he did my Carvin, transformation from left --> right and he did an absolutely fantastic job beyond belief, he didn't ground the bridge. The guitar has HSS : dimarzio super-distortion bridge/generic carvin middle/air norton S neck. I realized this right away. My rig basically consists of :
guitar --> boss me-25 --> headphones, so this was pretty audible. I tried with other DMZ guitars I have and they were dead silent.
So I conencted the bridge ground and I noticed that :
a) when playing via the me-25 with the amp unplugged the noise was there : not hum, more like a high freq bzzzz / hiss
b) when playing via the me-25 with the amp plugged (regardless of the amp being on) the noise was gone

I know there have been ages since I moded any guitar, but according to the theory should HB also cancel high freq hiss besides regular hum? Why does grounding the bridge actually works?
Again sorry for forgetting all the old classic original GN theory ... I am getting old, can you pls shed some light to this question?
 
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Experimentation (and common practice) shows you are correct, but I'd like some theory to back it up. He (tech) says that Gibson for many years did not ground the bridge of their guitars. He has been around for so long, he has worked in Sweden, Holland, he setup guitars for rolling stones, he was the tech of the (now deceased) Giannis Spathas (the greek Eric Clapton equivalent), ok, he aint got no degree from some elec. eng. Univ but still his opinion counts.
If the "strings/bridge plane + the body touching the strings" system is isolated electrically from the rest of circuitry, is it induction that creates currents to the hot signal? How does the theory work?
 
I don’t know the theory, but I’d be interested to see how he wires guitars to keep them from buzzing if there’s no ground.
 
JB_From_Hell said:
Your tech is wrong. Some active pickups don’t require a bridge ground, but passive humbuckers do.

The bridge ground works because it makes you a part of the circuit when you’re touching the strings.
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I don't think that is accurate. The bare wire just grounds the metal plate. It will work without it but it may be noisy as heel depending on your environment
 
Bill Dennis said:
I don't think that is accurate. The bare wire just grounds the metal plate. It will work without it but it may be noisy as heel depending on your environment
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They're not referring to the bare wire on a 4-conductor pickup, they're talking about grounding the bridge of the guitar. FWIW I used to have a 1977 Les Paul Custom with hum issues and my tech discovered that it didn't have a bridge ground. It was dead silent after installing one.
 
JB_From_Hell said:
Your tech is wrong. Some active pickups don’t require a bridge ground, but passive humbuckers do.

The bridge ground works because it makes you a part of the circuit when you’re touching the strings.
Click to expand...

This was always my position. But if he has another idea, I'd love to hear the science backing it up. Maybe he has some other sevret wiring trick he isn't disclosing. But I think if you are going to go against conventional wisdom, you'd better have a way to back that opinion up.
 
So the theory is that human body creates EMI or RFI noise picked up by the circuit (not by the HBs), so HBs are not able to cancel this noise because it is picked up by wires, pots, switches ?
I have to give the guy a good theory. He is a fantastic tech, so I gotta have a fantastic theory :)
 
Are you using a lot of gain? That might cause the hiss. That is pretty normal with higain and completeky different from the missing ground noise. Have you tried using a noise gate/suppressor? I think your boss me-25 has it built in, try turning it on!
 
Perhaps he is using the star grounding with a capacitor inline and plenty of shielding (see guitarnuts.com article about it). I've done that once before and the guitar was still very quiet. No bridge ground either.
 
Mincer said:
This was always my position. But if he has another idea, I'd love to hear the science backing it up. Maybe he has some other sevret wiring trick he isn't disclosing. But I think if you are going to go against conventional wisdom, you'd better have a way to back that opinion up.
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no tricks. I got the guitar from him and it hummed, I noticed in the first minute of playing.
 
ErikH said:
Perhaps he is using the star grounding with a capacitor inline and plenty of shielding (see guitarnuts.com article about it). I've done that once before and the guitar was still very quiet. No bridge ground either.
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the original GN advocated a big capacitor between bridge and guitar ground to protect against electrical hazard. I had done that in my early days of modding (2011).
 
nexion218 said:
Are you using a lot of gain? That might cause the hiss. That is pretty normal with higain and completeky different from the missing ground noise. Have you tried using a noise gate/suppressor? I think your boss me-25 has it built in, try turning it on!
Click to expand...

normal gain I'd say, what I am talking about here is :
grounded bridge --> dead silent
not grounded bridge -> hiss
 
dystrust said:
They're not referring to the bare wire on a 4-conductor pickup, they're talking about grounding the bridge of the guitar. FWIW I used to have a 1977 Les Paul Custom with hum issues and my tech discovered that it didn't have a bridge ground. It was dead silent after installing one.
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Same difference. The guitar will make sound but will likely be noisy as hell
 
greekdude said:
the original GN advocated a big capacitor between bridge and guitar ground to protect against electrical hazard. I had done that in my early days of modding (2011).
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Yup. The cap is there as protection. Won't eliminate the shock but will lesson how it feels. The diagrams I may still have and saw eliminated the bridge ground completely.
 
ErikH said:
Yup. The cap is there as protection. Won't eliminate the shock but will lesson how it feels. The diagrams I may still have and saw eliminated the bridge ground completely.
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Peavey did that for awhile, on certain guitars. Can't remember the value of the cap though. Maybe 0.01 uf.
 
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