nodehopper Posted December 8, 2010 Share Posted December 8, 2010 OK...I am mostly an acoustic guy so this is probably a very dumb question, but I wanted to get information before I take it to the local shop. I hate going in with out any understanding of what is going on. My LP Studio Premium Plus in amber has just started humming/buzzing when plugged into an amp. I have tried 3 different amps all with about the same hum. What I think might give a big clue is it hums when I am not touching any metal on the guitar, but as soon as I touch the strings, metal around input jack, metal on cable plug..etc. The hum goes away. The only things done to the guitar at about the same time as the hum started was swapping the original top hat knobs with speed knobs. Also the input jack was a little loose and I finger tightened the nut, but I think it also spun the jack a bit when I was doing that. The knobs were tight and took some tugging (bare hand only) to take off and get the new ones on. I am wondering if any of these might have twisted a wire or messed up the volume or tone controls? Would something like that be consistent with the hum going away when I touch metal? ...maybe I am guessing.... I ground it and the hum goes away? I opened the back cover and checked and no wires appear loose or broken off. the wires on the jack which I pulled out seem well attached also... Or does this sound like something bad? Do pups go bad? I did swap out the original pups for DiMarzio PAF® 36th Anniversary Neck DP103 model guitar pickup and DiMarzio PAF® 36th Anniversary Bridge DP223, but it has been a couple years and no problems at all until now. Here is the LP I am asking about. Link to comment Share on other sites More sharing options...
r2bflash Posted December 8, 2010 Share Posted December 8, 2010 OK...I am mostly an acoustic guy so this is probably a very dumb question, but I wanted to get information before I take it to the local shop. I hate going in with out any understanding of what is going on. My LP Studio Premium Plus in amber has just started humming/buzzing when plugged into an amp. I have tried 3 different amps all with about the same hum. What I think might give a big clue is it hums when I am not touching any metal on the guitar, but as soon as I touch the strings, metal around input jack, metal on cable plug..etc. The hum goes away. The only things done to the guitar at about the same time as the hum started was swapping the original top hat knobs with speed knobs. Also the input jack was a little loose and I finger tightened the nut, but I think it also spun the jack a bit when I was doing that. The knobs were tight and took some tugging (bare hand only) to take off and get the new ones on. I am wondering if any of these might have twisted a wire or messed up the volume or tone controls? Would something like that be consistent with the hum going away when I touch metal? ...maybe I am guessing.... I ground it and the hum goes away? Or does this sound like something bad? Do pups go bad? I did swap out for original pups for DiMarzio PAF® 36th Anniversary Neck DP103 model guitar pickup and DiMarzio PAF® 36th Anniversary Bridge DP223, but it has been a couple years and no problems at all until now. Your guitar is not broken, this is normal. Link to comment Share on other sites More sharing options...
T Bone Posted December 8, 2010 Share Posted December 8, 2010 Your guitar is not broken, this is normal. Well, he's noticed a change, so it may not be. Try a new guitar cable first. Next, are there any differences in lighting, the circuit the amp is plugged in to, small appliances added in the area, etc. etc.? Was your furnace running before, and is it now? Any of these things could possibly affect what you are seeing in noise. You may possibly have damaged a connection (even though they look good) on the input jack. Try loosening it back like it was, same condition? Try tapping lightly on each pot (or each knob). What about polarity of the amps, is it reversible, has it been reversed? These are all things I'd try before going further. Link to comment Share on other sites More sharing options...
Fringe Lunatic Posted December 8, 2010 Share Posted December 8, 2010 It sounds like a ground issue in the guitar. For example, if the bridge ground is broken, you'd have the problem you describe. If it was my guitar, I'd carefully check all of the wiring, especially ground connections. Link to comment Share on other sites More sharing options...
CajunBlues Posted December 8, 2010 Share Posted December 8, 2010 That is definitely a ground issue... Take a another look ... If you cannot figure it out, you will have to take it to a tech... I do a lot of electrical work on my guitars and there have been instances where I had ground issues I just couldn't figure out and I had to take it to someone more experienced... Link to comment Share on other sites More sharing options...
nodehopper Posted December 8, 2010 Author Share Posted December 8, 2010 That is definitely a ground issue... Take a another look ... If you cannot figure it out, you will have to take it to a tech... I do a lot of electrical work on my guitars and there have been instances where I had ground issues I just couldn't figure out and I had to take it to someone more experienced... Thanks for the input. To respond so some of the questions. It is happening at my house and I have a Monster Power strip for audio equipment that supposedly cleans the power and takes out the noise. And it happened at a friends house. I also tried 3 cables including a SpectraFlex Fatso that is a really great quality cable, with no changes. I did open the back and with it plugged in I tapped on the backs of the dials and very gingerly poked at wires etc. There was a bundle of wires that looked like it was coming from the pick up area and when I tapped on that it seemed to change the hum louder and quieter. But not being very experienced.... that was about all I felt I should do before asking here and thinking I needed to take it to a tech. I think from your replies it must be a solder point or connection that has wiggled loose or maybe a bad/cold solder that a small wiggle cause it to go south. Thanks ...I do feel better taking it in and having a clue before talking to the tech... I just hate going in clueless and looking like a dope! Link to comment Share on other sites More sharing options...
tartanbeastie Posted December 8, 2010 Share Posted December 8, 2010 Well i'm about as technically minded as a fish so i cant comment on the hum but my point is that theres no such thing as a dumb question, lets face it.. if you dont know something even if its relatively simple or straight forward the only way you will increase your own knowledge is by asking.. hope you get the hum fixed. Link to comment Share on other sites More sharing options...
nodehopper Posted December 8, 2010 Author Share Posted December 8, 2010 Well i'm about as technically minded as a fish so i cant comment on the hum but my point is that theres no such thing as a dumb question, lets face it.. if you dont know something even if its relatively simple or straight forward the only way you will increase your own knowledge is by asking.. hope you get the hum fixed. Isn't the old saying ...."there are no dumb questions.....only dumb people" :lol: I am joking ...yes thanks for that tartan! Link to comment Share on other sites More sharing options...
jnastynebr Posted December 9, 2010 Share Posted December 9, 2010 I dealt with this same issue not one week ago. I ended up completely re soldering every connection in the control cavity, and shielding every route in the body. The hum has decreased dramatically, but I don't know if I can credit this to the solder or the shielding. This is my one beef with Gibson QC. I actually had to do the same thing with my old Smart Wood. Had this issue with 2 of my 3 Gibsons and never with another guitar. Leads me to think something is being overlooked. Link to comment Share on other sites More sharing options...
r2bflash Posted December 9, 2010 Share Posted December 9, 2010 but as soon as I touch the strings, metal around input jack, metal on cable plug..etc. The hum goes away. You are going to spend a lot of time/effort and money on something that does not need to be addressed. If, when you touch the strings the hum goes away, there is nothing wrong with your guitar. I have a lot of guitars and there is a ground that goes to the bridge just for what you are describing. It is there so that when you touch the strings it will help eliminate hum especially on high gain amps. You just never noticed it before is all. But if you insist, I guess you can try to get it to stop humming when you are not touching it but don't you touch it when you are playing it? I am not trying to be a smart a$$ or anything but come on.... Link to comment Share on other sites More sharing options...
jnastynebr Posted December 9, 2010 Share Posted December 9, 2010 I have dealt with it twice, and its a pain in the butt. Its not unrealistic to expect that an expensive precision instrument like a Gibson guitar perform how you want it to. There is a fine line between the noise that every electric guitar generates from electrical interference or florescent lights, and the obnoxious hum caused by a loose ground, lack of shielding, or a bad solder joint. I don't know enough about this case to say what is causing this. I hope for this person's sake that they are just playing too close to their lap top, but if there is an issue with the wiring, it needs to be addressed. In researching this issue because of noise problems with my own Gibson guitars, I came across countless threads and youtube videos of Gibson players that were dealing with the same problem. This caused me to conclude that this is a QC issue for Gibson. I have owned a slew of guitars from Fenders to Carvins, and I have NEVER had a noise issue with any of them. I understand that this is hardly a scientific study, but in my personal experience, this is a problem. If my $300 RG doesn't howl when I'm not touching the strings, than my $2200 Gibson shouldn't either. Link to comment Share on other sites More sharing options...
r2bflash Posted December 9, 2010 Share Posted December 9, 2010 but as soon as I touch the strings, metal around input jack, metal on cable plug..etc. The hum goes away. He does not have a hum while he is playing it, just when he sets it down. My 76 LP Custom does the same thing and has done it since 1976. When I pick it up the hum goes away! So when I set it down I just turn the volume down, has worked great for 34 years! But maybe I should get it fixed. Link to comment Share on other sites More sharing options...
jnastynebr Posted December 9, 2010 Share Posted December 9, 2010 Where does it say that it hums when he puts it down? Sorry to hear your having problems with your custom, but hey, it is a Norlin. Never too late to fix a problem. Link to comment Share on other sites More sharing options...
r2bflash Posted December 9, 2010 Share Posted December 9, 2010 Where does it say that it hums when he puts it down? Sorry to hear your having problems with your custom, but hey, it is a Norlin. Never too late to fix a problem. Well...he does not say those exact words, but he does say when he touches the strings the hum goes away. So I am just saying that when you are playing it there is no hum and when you set it down it does hum because he is no longer touching the strings. I have many guitars that need you touching the strings so that all is quiet. That is why a ground is put on the bridge of most. Link to comment Share on other sites More sharing options...
CajunBlues Posted December 9, 2010 Share Posted December 9, 2010 He does not have a hum while he is playing it, just when he sets it down. My 76 LP Custom does the same thing and has done it since 1976. When I pick it up the hum goes away! So when I set it down I just turn the volume down, has worked great for 34 years! But maybe I should get it fixed. You know that hum bothers some peoople... And not others... I know it bothers the heck out of me... Whatever... It certainly doesn't affect the way the guitar sounds... Once he brings it to the tech, the tech will tell him whether or not the hum is normal... But, there is no doubt in my mind it did get worse after he messed with the knods/jack... I am going to at least give the original poster the benefit of the doubt... Link to comment Share on other sites More sharing options...
ChanMan Posted December 9, 2010 Share Posted December 9, 2010 That is definitely a ground issue... Take a another look ... If you cannot figure it out, you will have to take it to a tech... I do a lot of electrical work on my guitars and there have been instances where I had ground issues I just couldn't figure out and I had to take it to someone more experienced... Pretty sure this has come up before and this was the issue/fix. Good luck! Really sweet guitar! Link to comment Share on other sites More sharing options...
katetot Posted December 9, 2010 Share Posted December 9, 2010 Check groundings and re-solder everything if you can. Link to comment Share on other sites More sharing options...
nodehopper Posted December 10, 2010 Author Share Posted December 10, 2010 You know that hum bothers some peoople... And not others... I know it bothers the heck out of me... Whatever... It certainly doesn't affect the way the guitar sounds... Once he brings it to the tech, the tech will tell him whether or not the hum is normal... But, there is no doubt in my mind it did get worse after he messed with the knods/jack... I am going to at least give the original poster the benefit of the doubt... Thanks CajunBlues....it always is nice to get the benefit of the doubt once in a while. I am definitely gonna see if a local tech can find the issue. The hum is definitely louder than it was before and while I can't pinpoint that it happened exactly at the same time as I messed with things. In my mind it was about that time. If playing through my Fender Super Champ XD totally clean and low volume it is just noticeable. So if I wasn't particularly paying attention I may have missed it if I picked up and quietly practiced a bit. But switching over to the higher gain channel and with volume even at about 2 or 3 it is loud and annoying. Just to give an idea the hum is maybe half as loud as the guitar lightly strummed... not a super accurate description but you get the drift. And for you guys who want to dog Gibson on QC.....these are after market PUPs that were added a year or so ago. So it could be the installer just as easily as it was Gibby. Thanks again for the help....good to know what to do to get it fixed! Link to comment Share on other sites More sharing options...
Zonkers Posted December 10, 2010 Share Posted December 10, 2010 Good luck, I've got one guitar I cannot get the hum to stop on. But like you, when I'm touching the strings, bridge, anything metal on the guitar, the humming is pretty much gone. It's properly grounded, I checked, and had it checked out twice, but nada. It's a semi hollow, so shielding ain't gonna happen :P Link to comment Share on other sites More sharing options...
jmjohnson Posted December 11, 2010 Share Posted December 11, 2010 Sounds like the overall grounding is fine; if it wasn't, the noise wouldn't go away when you touch the metal on the guitar. If it does so consistently, on all the metal you touch (besides strap locks), not likely that something is loose ground-wise. There is EMI/RFI noise around where you play. Your body is a great collector of this type of noise...grab just the just hot/tip of the amp cable jack where it usually plugs into the guitar to hear just how much noise (current) you pass into the live amp. Ground yourself at the same time by touching both parts of the plug and you will sound a lot quieter. BTW, you can lay a few feet of aluminum foil on the floor and touch it with the cable plug tip to get the same noise (like a noise antenna). When you just hold the guitar in playing position, you are 'transmitting' all the electrical noise your body collects right into the electronics. But when you become grounded, by touching properly grounded bridge, strings, tuners, PUP covers, pots, ground lugs, shields, jack, switch, etc., (or any other grounded metal like metal on the amp), all that noise leaves your body and goes to ground instead of into the guitar signal/amp hot (which is why I think the overall guitar ground is fine). The aluminum foil would do the same thing - if you ground it somehow, through the guitar metal or by running a wire from it to an outlet grounding lug - and then lay the guitar on it, the guitar should get quieter. This is how shielding works - it intercepts RFI/EMI noise usually destined for the wiring/PUPs & eventually the amp hot, and dumps it to ground instead. When you are grounded YOU are now a great shield. If you left the guitar at arms length and touched metal/ground, it won't get any quieter, because you aren't close enough to shield it. The braided outer jackets of the PUP cables in a typical LP serve as conductors & as the shields for the cabling...possibly you twisted one of these connections loose, and that shield is no longer making a good connection to ground, or is touching a hot lug/point, or a capacitor, so the noise it collects is being tranmitted (or passed directly) into the hot signal instead of ground. Your body would still shield the shield, so you might want to check for this. But direct contact would likely short out the signal entirely, so not too sure of that idea. Since you said you twisted the output jack, I would start there just to be sure. You can use a multi-meter to check for ground continuity and/or shorts; or if a meter is not available, maybe by using a wire, or yourself, to touch different metal components and compare to a known good grounding point to see if it makes a difference (goes quiet or not). If this all checks fine, then it is simply noise...you can try to figure out what is making the noise in your playing area and eliminate it. Dimmers (anywhere in the house)? CRT monitor? AC unit? Soldering iron? Fluorescents? Dirty power? You could add shielding to the guitar. You could get a noise gate. You can adjust your treble to limit it as much as possible. You could ground yourself 'permanently' when playing. Link to comment Share on other sites More sharing options...
nodehopper Posted December 16, 2010 Author Share Posted December 16, 2010 UPDATE: Just got my LP back from the guitar tech. He did the full shielding job with copper and Hum is significantly better! Yeah !!! I suppose I will never know for sure what the issue was, it could be that gutting the guitar and re-soldering could have fixed a bad solder point or when he put it all back together any issue with grounding was fixed. He didn't see or find anything particularly obvious. The tech said he ran solid core copper wire through channels between pups and pots to act as additional grounding .....not sure I understand that, but it sounds really cool :) Thanks again to all for the info and support! Link to comment Share on other sites More sharing options...
jmjohnson Posted December 16, 2010 Share Posted December 16, 2010 Glad you got it worked out! Enjoy! Link to comment Share on other sites More sharing options...
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