Hi,
I currently own a Jackson KE3 kelly. Around the time i bought it, i knew nothing about electric guitars and had to go through the painful process of learning everything about it.
Now, after 3 years i plan to change the current duncan designed pickups to JB model Seymour duncan pickups. I want to do the job myself but before i try to install the new pickups ive been studying the current wiring and how to properly wire my pickups.
Ever since i bought the guitar ive always had feedback when my hands were off the strings, as soon as i touched the strings the noise would disappear. I first thought it was a problem with the effects processor (VAMP2) that i was using so i bought a BOSS GT-8 but i still had the same problem. Then one day the strings started giving me small electric shocks, not very bad but small shocks when my fingers barely touched the strings. I got a tester and found out an electrical current was flowing not only through the strings, the bridge, the volume nob, the cables and even the Body of the GT-8. I had no idea what it was i finally gave up and thought it was the pickups. Now that ive been looking on how to install pickups i thought maybe it was a grounding problem.
I've been studying the cavity in my guitar and noticed that there was a screw in the body with a small steel plate and all the earth connections were soldered to that steel plate and screw. Could the feedback be possible due to improper grounding? I went to so many websites and still dont get what grounding a guitar means because theres no connection with the ground at all. Can someone please tell me what grounding means in terms of the guitar, what the screw is for, if theres anything special i need to do to ground my new pickups so i dont have the same problem with my guitar, and what the current in my strings and guitar body means?
I have a decent setup and have spent so much money on trying to fix my sound. If the new pickups dont make a difference i think im just going to have to burn my jackson, boss and seymour pickups in one big pile....
Please help...
The guitar is properly grounded from your description. All of the pickups, switches, pots, cavity shielding, bridge and strings should be grounded through a common connection, which itself is connected to the outer terminal of the jack. The ground goes through the outer sheath of the cable to the chassis of the amp. If you're getting shocked, the amp isn't properly grounded and has some sort of electrical leak (short circuit) that's putting ungrounded voltage on its chassis. That's dangerous and needs fixing.
"A cheerful heart is good medicine."
Thanks ricochet, ive always thought it was something wrong with the guitar but now since i started learning about this stuff its made it abit better. I do have a few questions though if you dont mind answering them:
1) I get about how the cable grounds the circuitry now. I think i might have found the problem, the cable which i use is a hotline cable and one day while jamming with a friend i steped on the connector end of the cable and bent it quite abit, so the end of the cable is now bent, it still works but do you think its because someone the outer sheath got messed up cuz i stepped on it?
2) When you say cavity sheilding is that some special covering on the inside? Because to me it just seems like wood with the same black finish and a screw drilled into one of the sides.
3) I dont use an amp, i connect it directly with home stereo system through its mic input using the mono out. I emailed boss one day and they said its some sort of impedance mismatch. I had no idea what that meant lol. Can the noise be cuz of that?
Anyways thanks for all the help. I was looking through your profile and saw you were a doctor by proffession. I too am a medical student, 5th year. And its hard to take time out to play the guitar even though i love it. So its nice seeing someone at your position who still has the love and time to do this stuff. Maybe there is hope for people like us :P Thanks alot
Cavity shielding is a protective layer of conductive stuff (often copper foil or carbon paint) that reduces the EM waves interfering with your guitar signal. That conductive stuff needs to be grounded to send those EM waves to ground. What you get is a Faraday cage.
The reason that you get hum when you are not touching the strings and it goes away when you do touch is them is because you too are a source EM interference or at least an antenna for it. That gets pickup up by the guitar electronics. If you touch the strings then that grounds you out through the string ground (a ground wire often to the bridge of your guitar).
One good place to start is here - http://www.guitarnuts.com/wiring/menu.php
Pop music is about stealing pocket money from children. - Ian Anderson
Does your wall socket (mains outlet) have a connection to ground? There should be three connections at the back of your wall socket - Live, Neutral and Earth (ground). If there is no earth connection, all the grounding in your guitar, amp, etc. has been nullified, there's nowhere for leaks to go. It is also a potential danger to anyone using an electrical appliance connected to that socket.
If the building has been wired to international standards, the earth wire will be green & yellow striped.
The fact that you are getting a shock, when you touch the strings, is a sign that something is very wrong in the amp/stereo unit. Under normal circumstances, the guitar lead transmits only the weak current generated by the pickups. It should NEVER carry an electrical current to the guitar. Get the amp checked BEFORE you use it again. If you need any encouragement, I can probably find a list of performers who have been electrocuted by their faulty equipment and not lived to perform again.
I started with nothing - and I've still got most of it left.
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Shock !!? Yeah don't be playing you're setup anymore. :!:
I'm no electronics expert at all but I have been getting into some amp modding. I've also read about gtr players being killed by no ground. That thing might be waiting for you to touch something else or wet feet. You don't have to fry to die, it only takes a few amps to stop your heart.
Do what Greybeard says and check your house wiring.That outlet has to go to ground.Even if it is the 3 slot type outlet, an old building or sh@tiy contractor could mean it's not grounded.
Again, I'm no expert but if my guitar ever shocks me then my new hobbie will be electronics study forsure.
I doubt it's your gtr. I'd also go ahead & replace or fix that cord & get a real amp. Some high gain settings can hiss n disappear when touching the strings, but a shock is never good. Be safe man.
I found a site that quoted several research studies and they came out with the concensus that 0.2A - 0.3A are sufficient to kill a human. AC also requires far less to kill than DC.
I started with nothing - and I've still got most of it left.
Did you know that the word "gullible" is not in any dictionary?
Greybeard's Pages
My Articles & Reviews on GN
I wonder about the amp that peesho is using. It's not mentioned at all. Is it a modern amp? Is it an early 70's or older amp with no ground? These had a polarity switch to change which can lead to AC in the chassis. That might be the source of his shocking experiences. If it's a more modern amp (or an updated older amp) has the ground prong been cut off the plug?
Pop music is about stealing pocket money from children. - Ian Anderson
He said it was a stereo.
Peesho, I think your stereo's got problems.
"A cheerful heart is good medicine."
Thanks alot people, for all the awesome ideas. Yeah i was pretty sure something was very wrong with the setup the first time i got shocked, i kept justifying everything with high school physics lol 'obviously theres a current because the strings are vibrating in a magnetic feild' but now after i learnt about all the grounding stuff im seriously doubting all that! Haha im going to check my stereo system out right now. Thanks for the input people!
