ashcat_lt
Well-known member
If the noise goes away when you touch the strings, it indicates that the bridge ground is working fine! It’s supposed to work that way! The noise is you, and connecting you to the “ground” end of the guitar circuit will reduce the noise. If it keeps buzzing when you touch the strings, then you know you have a problem.
It still leaves the question of whether you can reduce the noise that is there when not touching the strings, which involves all of the other things mentioned above: shielding, staying away from EM noise sources, etc.
Edit - I guess this whole post is mostly replying to [MENTION=89697]ecc83[/MENTION], so let’s add this...
It’s my understanding that there are certain old amps designs where the very high B+ voltage is connected to the chassis via an electrolytic capacitor. That of course blocks DC, so no danger. Until that cap fails, and electro caps like to fail to shorted, which then puts the B+ essentially right on the strings. This isn’t actually dangerous on its own either unless youre standing barefoot in a puddle or sitting on a radiator or walk up and put your mouth on the microphone plugged into the PA. Then something becomes a fuse, and that something could very well be you. It kind of requires several fairly rare conditions to happen at the same time, but it is at least potentially lethal.
That is not an argument against the bridge ground on the guitar. It’s an admonition to never play an amp with a two-prong power cord. Get the power section rebuilt by somebody who knows what they’re doing so that it meets modern safety standards.
The original GuitarNuts site made a big deal out of this, and did a thing where all of the “touchable grounds” (bridge, pots, etc) were isolated from the jack ground (which itself is touchable, but there’s nothing we can do about that) via a capacitor, but in the GuitarNuts2 forum which spawned from it, we’ve pretty much rejected it and decided it’s generally not worth the trouble and kind of only provides a false sense of security.
It still leaves the question of whether you can reduce the noise that is there when not touching the strings, which involves all of the other things mentioned above: shielding, staying away from EM noise sources, etc.
Edit - I guess this whole post is mostly replying to [MENTION=89697]ecc83[/MENTION], so let’s add this...
It’s my understanding that there are certain old amps designs where the very high B+ voltage is connected to the chassis via an electrolytic capacitor. That of course blocks DC, so no danger. Until that cap fails, and electro caps like to fail to shorted, which then puts the B+ essentially right on the strings. This isn’t actually dangerous on its own either unless youre standing barefoot in a puddle or sitting on a radiator or walk up and put your mouth on the microphone plugged into the PA. Then something becomes a fuse, and that something could very well be you. It kind of requires several fairly rare conditions to happen at the same time, but it is at least potentially lethal.
That is not an argument against the bridge ground on the guitar. It’s an admonition to never play an amp with a two-prong power cord. Get the power section rebuilt by somebody who knows what they’re doing so that it meets modern safety standards.
The original GuitarNuts site made a big deal out of this, and did a thing where all of the “touchable grounds” (bridge, pots, etc) were isolated from the jack ground (which itself is touchable, but there’s nothing we can do about that) via a capacitor, but in the GuitarNuts2 forum which spawned from it, we’ve pretty much rejected it and decided it’s generally not worth the trouble and kind of only provides a false sense of security.
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