a thread last week, talked of a player with a hot amp-chassis. That's one circumstance that I can think of.
Enjoy the benefits of a premium membership!
Upgrade Account
-
TalkBass has been independent since 1998. Add your voice.
Create a free account to reply to discussions, view embedded media, and browse with fewer display ads.
Join free Log in
Want zero display ads or expanded classifieds tools? Compare plans.
WHAT!?
- Thread starter AlphaMale
- Start date
a thread last week, talked of a player with a hot amp-chassis. That's one circumstance that I can think of.
Bare feet on concrete could do it. I saw a guy get shocked on 347v once in a bar in Montreal cuz his DI was plugged in a place where it shouldnt have been. simple plywood stage. wearing shoes. didnt get the full story but it didnt look too fun for him.
How would a hole be made unintentionally? It was made with a very long drill bit. Often there is a large hole routed in the body first so the drill bit can be angled better.
The wire sits under the metal bridge and connects it to ground, which then grounds the strings.
Metal objects pick up stray electrical fields, and these stray fields end up getting picked up by the pickups, which we hear as hum and buzz. Think of the strings as antennae.
When you ground the strings, the fields are then directed to ground, and they no longer appear in the signal.
Pickups like EMG's don't require the strings to be grounded because the pickups is enclosed in a Faraday Cage made of fine brass screen. This effectively shields the pickup from noise.
I measured 80 volts from my bass to a microphone once after I got a bad shock.
The ground on the PA was bad.
- Dec 20, 2004
- 4,267
- 2,481
- Disclosures
- Player-Builder-Founder: Honey Badger Pickups & Regenerate Guitar Works
exactly ... and here's a few extras to consider:
* bad wiring in the house/club you're playing at resulting in an improper ground. your lips touch a metal microphone mesh while singing and *BAM!* lights out bro
* some equipment still uses polarity for its circuit protection (keep the equipment side on the cold side of the power source) ... in cases where someone modified the two prong plug so it could be inserted backwards - and then it did get inserted backwards! - *BAM!* you're on the hot side of the circuit and it's lights out bro
* there are many other scenarios, but by now you should get the point
I tend to provide a grounding wire to the bridge, but I do not connect it to ground within the cavity. instead I leave a note connected to it within the cavity that explains what the wire goes to and the potential danger of connecting that wire to ground (which then puts a player touching their metal strings into the circuit.) in case where the house wiring (or something else) is faulty, it's potentially lights out bro ... and your relatives will be sorting out the wrongful death suit
I have personally been 'buzzed' too many times already, and I really dislike sitting in the hospital attached to the 'octopus' and then having to explain to my wife what all those little round hickies on my chest are
if you play with meatl strings and have not absolutely assured with a testor that the wiring is ok at this specific stage on this specific night ... drop the string ground and keep a finger on the strings between songs - 60Hz EMI buzzing goes away, and you live to play another night
o - and guys/gals ... lighten up. those of us who live here in the Luthier's Forum don't take kindly to the rude behavior in this thread (and a couple others here lately) ... if you can't play nice go somewhere else (like OT) where that childish behavior is tolerated ... that kind of immature behavior is NOT tolerated in this house
all the best,
R
Oh something I just thought of... I started taking one of those neon bulb outlet testers with me. Touch it between your strings and something like a mic you will be using, or your guitar player 
and see if it lights up. If it does, you have a problem!
and see if it lights up. If it does, you have a problem!I thought putting your hand on the strings takes away hum because the strings grounds you and you act as a big old electromagnetic shield sending radio frequencies to ground from you through the strings. With out the strings at ground potential you don't act as a grounded shield and don't get the hum cancelling effects of putting your hands on strings. Since you simply standing on the floor makes a really bad ground connection. Unless your standing barefoot in a puddle. but even then you still have a nice bit of resistance in you.
The post wasn't written to scare you, it was written to inform you of why it happens. I've been zapped by guitars and basses before - it's never an issue with faulty wire on the guitars end, it's always a ground issue in the outlet you're plugging in.
I'll keep the bridge of my studio basses grounded and my gig basses ungrounded. I prefer not to get the bejebus shocked out of me.
I'll keep the bridge of my studio basses grounded and my gig basses ungrounded. I prefer not to get the bejebus shocked out of me.
An acquantance of mine - Lesley Harvey of Stone The Crows (Google, Youtube) was electrocuted to death onstage when he shorted a microphone & his guitar across his chest. Someone had messed with the mains plugs during the band's break. A direct result of a grounded bridge.
If you *don't* ground the strings (and if you use coated strings it doesn't happen anyway) AND providing you use Star Grounding techniques, *and* your control cavities are screened, you shouldn't need that bridge connection at all.
I've just renovated an old Vantage bass that way and it's fine and quiet.
If you *don't* ground the strings (and if you use coated strings it doesn't happen anyway) AND providing you use Star Grounding techniques, *and* your control cavities are screened, you shouldn't need that bridge connection at all.
I've just renovated an old Vantage bass that way and it's fine and quiet.
I think this thread should be held up as an example of the pitfalls of choosing a silly username!! 
(the first sentence in my first post was reagarding exactly that, some people took it as a negative attitude) indeed, group hug. this forum has been very helpful to me in the past years and its not a place to lash out at others or be close minded. Peace.
No, because it still takes away hum if you are not touching the bass.
Leave it sitting on a stand, and disconnect the ground wire to the bridge. Hear the hum?
Your body has too high a resistance to act as a ground connection... plus you are not in your bare feet on concrete. You touching the strings does help ground your body I suppose.
The bass player from the Pretenders also suffered health issues from a bad shock which probably led to his death.
I had one of my Rics totally shielded with copper foil, two humbucking pickups (Hi-A and Gibson Sidewinder) and no string grounding, and it was dead quiet, even with a built in preamp.
I don't agree that star grounding is necessary in a bass... in a tube amp, yes. There is only one ground path to the amp, the rest acts as a ground plane, and the potential is never different enough to cause a ground loop.
I think this thread should be held up as an example of the pitfalls of choosing a silly username!!
Don't forget the signatures either
You're 17 years old! The only thing you're alpha over is the sandbox! You've acquired a lot of attitude and very little common-sense-read-every-response skills! [DenisLeary]Pull up your pants![/DenisLeary]
hahha, don't forget that it's AlphaMale that's posting, we should set our expectations accordingly.
Attributing the hole and wire to "grounding" is clearly a conspiracy cover up attempt.
This is clearly an act of sabotage.
This is clearly an act of sabotage.
