Jungle VIP Posted February 21, 2012 Share Posted February 21, 2012 Hi everyone, I finally caved and decided to ask you guys about my problem as I can't figure this out and it's driving me nuts! So the thing is my Lakland 55-60 and what I guess is a relatively uncommon earthing problem. When I touch the control plate, jack (which is metal) and bridge, I get a loud and intrusive pop. Personally I think it is way too loud as it intrudes on my playing but I understand that this is to be expected to some degree. My real upset comes from the strings... When I place my fingers on the strings with no pressure and run them up and down I get terrible crackling! I'm no master but I have a fair amount of experience with pro audio gear and guitar/amps/earth loops etc. and I am stumped so I put it to you and hope you can help me out! [b]What I have done so far:[/b] Checked the earth cable from the tone pot to the bridge. Re-soldered connections from the PUPs to the pots. There was no connection from the tone pot to the sleeve so I made one but no change. Tried with a different head and cab. I tried completing the diagram attached and found it did not change my results. Linking the shielding paint to the control plate. Turned off all electronics like LCDs, other speakers and lights. [b]Things to note:[/b] There is only shielding paint inside the cavity and it doesn't come over the edges. [b]Things I'm waiting to try:[/b] Shielding the control cavity with copper tape. Change the preamp. I guess the first question is: Has anyone come across this before? Any help would be greatly appreciated. Thanks, H Quote Link to comment Share on other sites More sharing options...
icastle Posted February 21, 2012 Share Posted February 21, 2012 Try taking a look at the wire that runs from the bridge back to the common earth point inside the bass - that's the first place I'd check as it seems to be a very common point of failure. Quote Link to comment Share on other sites More sharing options...
mart Posted February 21, 2012 Share Posted February 21, 2012 [quote name='icastle' timestamp='1329857120' post='1548700'] Try taking a look at the wire that runs from the bridge back to the common earth point inside the bass - that's the first place I'd check as it seems to be a very common point of failure. [/quote] +1, except that this is also the first place the OP checked: [quote name='Jungle VIP' timestamp='1329847729' post='1548504'] [b]....What I have done so far:[/b] Checked the earth cable from the tone pot to the bridge.....[/quote] So, next: I'm guessing you'll already have tried using a different cable? Is the buzzing the same with both of your amps? And have you tried plugging the amp(s) in to a different power socket? It's obviously some earthing problem, and the strings/bridge/etc should be connected to the earth via the bridge and then the wire to the pot casings and then to the jack socket. If those connections are good, and the instrument cable is sound, then I fear there must be an earthing problem in the amp(s). Quote Link to comment Share on other sites More sharing options...
mart Posted February 21, 2012 Share Posted February 21, 2012 (edited) If you have a multimeter, you could do an overall check of the earthing on the bass by plugging a cable in, and checking the resistance between the strings and the other end of the cable (the sleeve, not the tip). There should be very little resistance at all if the bass earthing is good. If there is resistance, then check the resistance between the strings and the jack socket, and then between the strings and the pot casings etc. By a process of elimination, you'll find out where the gap is. Edited February 21, 2012 by mart Quote Link to comment Share on other sites More sharing options...
icastle Posted February 21, 2012 Share Posted February 21, 2012 [quote name='mart' timestamp='1329857526' post='1548708'] +1, except that this is also the first place the OP checked: [/quote] Oh good grief How can I have possibly missed that?!? Quote Link to comment Share on other sites More sharing options...
Jungle VIP Posted February 21, 2012 Author Share Posted February 21, 2012 Thanks for the responses guys. As Mart said, I've already tried the bridge earth and yes, I have tried a different cable. I have also tried the different mains socket test and had no luck although I suspect they were on the same ring. I thought the same about the amps but when plugging it into logic through a sound card or using iRig and my phone, I get the same problem. I think you're right Mart, I will have to grab a multimeter and start crunching some numbers. I've been looking at one on amazon today uming and arhing whether or not to get it. How much higher than 0 is acceptable? Thanks. Quote Link to comment Share on other sites More sharing options...
icastle Posted February 21, 2012 Share Posted February 21, 2012 Right. I've read it properly this time. Soldered connections to pot casings seem to cause a lot of people problems (there have been numerous threads on here about that) so that would be a good place to look. One thing that does bother me though, did you make any changes/repairs/upgrades to the bass electronics prior to this issue surfacing or did it just start happening one day? Quote Link to comment Share on other sites More sharing options...
gjones Posted February 21, 2012 Share Posted February 21, 2012 (edited) I had a similar problem when I installed a John east J-retro in my Jazz. What I've now done is screened all the cavities with 3 layers of screening paint and made sure that the copper earthing strip (it's an old MIJ 62 reissue type Jazz) from bridge to pickup plate is connected to the earthing circuit securely. The popping sound has almost gone - it only happens now if I touch the bridge pickup with my finger. There's plenty of info about screening and earthing basses on this forum if you use the search facility at the top right of this page (which is what I did). Edited February 21, 2012 by gjones Quote Link to comment Share on other sites More sharing options...
Jungle VIP Posted February 22, 2012 Author Share Posted February 22, 2012 I've made no changes and it's been like this since I had it but I can't speak for the previous own. I think it's standard. Looks it. I didn't know about the pot casings so thanks! I actually just ordered a J-Retro this afternoon (already had an email from John saying I'll have it before 1pm tomorrow!) so installing that should be interesting. I've got copper tape on the way and think I might just go crazy with it in the control cavity. Thanks for the help guys. Quote Link to comment Share on other sites More sharing options...
mart Posted February 22, 2012 Share Posted February 22, 2012 [quote name='Jungle VIP' timestamp='1329865946' post='1548973']...How much higher than 0 is acceptable?... [/quote] Even with the cable I'd expect a reading of less than 1 ohm, but I'd guess that 1 or 2 ohms should be ok, and (guessing a bit further, so I'm hoping someone more expert will chip in) I'd reckon that it would need to be a good few K ohms before the audible popping became a big problem. Quote Link to comment Share on other sites More sharing options...
BILL POSTERS Posted February 22, 2012 Share Posted February 22, 2012 Hope its not too daft a question, but is this just in one building ? If it is, very dodgy mains earthing might be something to do with it. Quote Link to comment Share on other sites More sharing options...
BOD2 Posted February 22, 2012 Share Posted February 22, 2012 Static electricity ? Discharging from your body through the bass to earth ? It's possible if you have a lot of man made fibres around (carpets) or you're wearing a microfibre fleece. Not sure what the solution would be, though. Quote Link to comment Share on other sites More sharing options...
Jungle VIP Posted February 22, 2012 Author Share Posted February 22, 2012 Well the multimeter is on the way so that might help but I'm still tinkering. The copper tape arrived today and I shielded the control cavity, pick guard, PUP magnets and added a bit around the bridges connection to earth to make a better contact. It's still crackling! Johnston, unfortunately yes, I checked both ends. I even resoldered the connection to the pot casing and exposed some new cable at the bridge end to see if that helped but no luck. Brancini and Bod2 still have good points I haven't managed to test the whole system in a different building and I may indeed be Static Man! Would you guys say it's not likely to be the building if it still happens when playing into my phone? I thought that would make sense but I might be missing something. Got to try the preamp now but it arrived at the wrong address! Quote Link to comment Share on other sites More sharing options...
Jungle VIP Posted February 22, 2012 Author Share Posted February 22, 2012 Oh dear... I just tried the static theory by earthing myself on the radiator whilst touching the bridge, control plate and strings... It's SIGNIFICANTLY reduced. Nothing from anywhere but the bridge which has a small pop... I am Static Man! Wow. Thanks for you help guys and congrats to Bod2 for getting it. Now just to figure out how I can earth myself! Quote Link to comment Share on other sites More sharing options...
Jungle VIP Posted February 22, 2012 Author Share Posted February 22, 2012 Sounds painful.... Quote Link to comment Share on other sites More sharing options...
mart Posted February 22, 2012 Share Posted February 22, 2012 [quote name='Jungle VIP' timestamp='1329929371' post='1549940'] Sounds painful.... [/quote] No, could be worse - he could have suggested the crocodile clip in your boxers Quote Link to comment Share on other sites More sharing options...
StraightSix Posted February 22, 2012 Share Posted February 22, 2012 [quote name='Jungle VIP' timestamp='1329926839' post='1549890'] Oh dear... I just tried the static theory by earthing myself on the radiator whilst touching the bridge, control plate and strings... It's SIGNIFICANTLY reduced. Nothing from anywhere but the bridge which has a small pop... I am Static Man! Wow. Thanks for you help guys and congrats to Bod2 for getting it. Now just to figure out how I can earth myself! [/quote] That may not be static - when you touch the radiator you are earthing through the house so I would expect the buzz to subside. Have you tried another mains lead and/or extension board on the amp...? Quote Link to comment Share on other sites More sharing options...
Jungle VIP Posted February 22, 2012 Author Share Posted February 22, 2012 I hadn't tried a different mains cable and that seemed to be a good idea. I just tried it a minute ago and a) the crackling was worse and when I tried to earth myself like before, I started getting shocks between me and the radiator/strings! Hmmm.... I really need to find somewhere else to test my setup. Quote Link to comment Share on other sites More sharing options...
StraightSix Posted February 22, 2012 Share Posted February 22, 2012 (edited) Do you have another floor you could try it on - generally domestic wiring is done with a ring main for each floor so the problem may just be on one of your rings *EDIT* - please take little care if the shocks are getting worse, we don't want any charred bass players. Edited February 22, 2012 by StraightSix Quote Link to comment Share on other sites More sharing options...
BOD2 Posted February 22, 2012 Share Posted February 22, 2012 [quote name='Jungle VIP' timestamp='1329926313' post='1549875'] Would you guys say it's not likely to be the building if it still happens when playing into my phone? I thought that would make sense but I might be missing something. [/quote] Hang on... are you saying that with your bass plugged directly into the phone, with no AC adaptors anywhere, just bass and phone, you still get the crackling noise ? If that's the case then it has nothing to do with the mains wiring in the house. It could well be static. Sometimes the shoes you wear are good insulators and don't allow the static to discharge. Try playing with no shoes on (I know it sounds daft). Does that make any difference ? If it does then it is definitely static. Quote Link to comment Share on other sites More sharing options...
Jungle VIP Posted February 22, 2012 Author Share Posted February 22, 2012 I have to agree with Bod2. I think it is there is something freaky going on with static rather than mains. I don't think it will be possible to resolve it completely but I'm luckly enough to have string routes through the bass. I might fashion something to go through from the back of the bass to make contact with the bridge to resolve it. If anyone else has some awesome incite I'd welcome it with open arms. Quote Link to comment Share on other sites More sharing options...
StraightSix Posted February 22, 2012 Share Posted February 22, 2012 Did you try the 'shoes off' routine...? Quote Link to comment Share on other sites More sharing options...
Jungle VIP Posted February 22, 2012 Author Share Posted February 22, 2012 Yea... The shoes off routine has been standard from the beginning. Like I said, I'm stumped. Quote Link to comment Share on other sites More sharing options...
icastle Posted February 22, 2012 Share Posted February 22, 2012 [u][quote name='StraightSix' timestamp='1329934136' post='1550032'] Do you have another floor you could try it on - generally domestic wiring is done with a ring main for each floor so the problem may just be on one of your rings *EDIT* - please take little care if the shocks are getting worse, we don't want any charred bass players. [/quote][/u] +1 Try running an extension from an upstairs socket. Also, it would be worth doing a test on the actual earth wiring. A multimeter isn't really the right tool but you could do a fairly crude test to 'prove' that there is an earth connection of some sort there - kitchen sink or radiator pipe (assuming you have metal ones) to an earth point on a mains socket using the continuity setting (usually shown as a diode symbol... ->| on most DVMs). Ask a mate if you can pop round with your amp and bass to see if the problem is equipment or environmentaly related could also save a lot of guesswork as well, Quote Link to comment Share on other sites More sharing options...
BILL POSTERS Posted February 22, 2012 Share Posted February 22, 2012 (edited) [quote name='Jungle VIP' timestamp='1329926839' post='1549890'] Oh dear... I just tried the static theory by earthing myself on the radiator whilst touching the bridge, control plate and strings... It's SIGNIFICANTLY reduced. Nothing from anywhere but the bridge which has a small pop... I am Static Man! Wow. Thanks for you help guys and congrats to Bod2 for getting it. Now just to figure out how I can earth myself! [/quote] Well at least you know now that the strings are not live cos of a really serious earth problem with your mains wiring. Otherwise you could well be dead now. Seriously...NEVER NEVER NEVER earth yourself with one hand while touching something faulty with the other. One possibility that struck me was that your mains isnt earthed very well, and something else in the house is faulty. That way the sockets earth could well have been live, through a high resistance path, but still live.. Edited February 23, 2012 by BRANCINI Quote Link to comment Share on other sites More sharing options...
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