FirstBass Posted January 21, 2022 Share Posted January 21, 2022 Helloski I bought a Harley Benton Jazz copy in the Summer of 21 purely out of curiosity. £139???? It's gotta be rubbish hasn't it? Err , no! Natural finish Vintage Series JB75-MN Apart from it's sheer heft, I love it. Love the look and love the way it plays There's one thing that's been bugging me though. Playing... no buzz. hands off strings..... buzz! I bought some 20mm wide copper tape from Ebay and last night I set about shielding the body (no provision for shielding whatsoever on this from the factory) About 2 hours to do it all, link all cavities, cover back of plates, test with a meter and stick back together Now - Perfick! I know i've not re-invented the wheel, but what a satisfying job to carry out. Even made The Apprentice bareable to watch (where do they find those people???? ) So... Happy Glambass That's it really.... Bye! Jon I 8 Quote Link to comment Share on other sites More sharing options...
Downunderwonder Posted January 23, 2022 Share Posted January 23, 2022 Cool. You will have incidentally grounded the bridge in the process since there was no buzz when you grounded it yourself. Next time you're playing under a dimmer or fluorescent lights you'll be golden too. 1 Quote Link to comment Share on other sites More sharing options...
Hellzero Posted January 23, 2022 Share Posted January 23, 2022 The forgotten bridge grounding is a myth. All the basses I had to fully shield, and we are speaking hundreds if not thousands, all had a grounded bridge and a theoretically perfect ground continuity... The only way to solve this typical Fender (and relatives 😉 ) issue is to do a perfect shielding with all cavities linked to have a total continuity. The graphite paint or so called copper paint is not working at all, which is explained by the poor conductivity of the paint (check with a meter if you don't believe me) and the lack of links between the cavities. I've been telling that Faraday principle for years and I'm glad someone else is also "telling" it. 3 Quote Link to comment Share on other sites More sharing options...
FirstBass Posted January 23, 2022 Author Share Posted January 23, 2022 The bridge had a wire fanned out beneath it that was earthed on the back of a pot I also put copper tape beneath it as well as the wire I made a copper tape "wire" to run from the pickup cavity to the control cavity and made sure I had continuity between them Passed between each cavity and taped in place I overlapped the tape from the cavities to the backs of the scratch and pot plate so they had continuity when screwed back on It wasn't super pretty, but it did a good job. I wasn't expecting the improvement I got.... It really has transformed the old girl I will definitely be gigging the old girl now ☺️ 2 Quote Link to comment Share on other sites More sharing options...
FirstBass Posted January 24, 2022 Author Share Posted January 24, 2022 Not the prettiest, but it works a treat! 8 Quote Link to comment Share on other sites More sharing options...
Downunderwonder Posted January 24, 2022 Share Posted January 24, 2022 On 23/01/2022 at 22:49, Hellzero said: The forgotten bridge grounding is a myth. All the basses I had to fully shield, and we are speaking hundreds if not thousands, all had a grounded bridge and a theoretically perfect ground continuity... The only way to solve this typical Fender (and relatives 😉 ) issue is to do a perfect shielding with all cavities linked to have a total continuity. The graphite paint or so called copper paint is not working at all, which is explained by the poor conductivity of the paint (check with a meter if you don't believe me) and the lack of links between the cavities. I've been telling that Faraday principle for years and I'm glad someone else is also "telling" it. Can you explain how the touching strings eliminated the buzz then? Quote Link to comment Share on other sites More sharing options...
Hellzero Posted January 24, 2022 Share Posted January 24, 2022 28 minutes ago, Downunderwonder said: Can you explain how the touching strings eliminated the buzz then? Bridge made out of bad conducting alloy showing good results on a meter, but being really poor in real life or mechanical issues in the bridge itself... There is no logical, to date, scientific reason behind this typical Fender(ish) issue. All I can say is, as I mentioned earlier and as @GlamBass74 explained for his bass, that all the instruments I had to fully shield had all a theoretically well grounded bridge, but were buzzing when not touching the strings and became dead quiet after a full shielding as explained, twice, above. Sometimes you have to accept that science, at the present day, doesn't have all the answers to all our questions. It's not a mystery, it's just that science still has to evolve. 1 Quote Link to comment Share on other sites More sharing options...
Downunderwonder Posted January 24, 2022 Share Posted January 24, 2022 14 minutes ago, Hellzero said: theoretically well grounded bridge, There's your 'missing' science! Clearly the bridge was NOT grounding! Quote Link to comment Share on other sites More sharing options...
Downunderwonder Posted January 24, 2022 Share Posted January 24, 2022 Ugh. If it was grounding then touching the strings would not have made a difference! Quote Link to comment Share on other sites More sharing options...
Downunderwonder Posted January 24, 2022 Share Posted January 24, 2022 Bernie is poking a banana in his ear. Burt : ''Earnie, wtf?'' Earnie : ''I am keeping the crocodiles away from Sesame St'' Burt : ''EARNIE, THERE ARE NO CROCODILES ON SESAME ST!!!" Earnie : ''See, it's working!''. 1 Quote Link to comment Share on other sites More sharing options...
Hellzero Posted January 24, 2022 Share Posted January 24, 2022 56 minutes ago, Downunderwonder said: Ugh. If it was grounding then touching the strings would not have made a difference! Check the link below as you seem to take me for an idiot. Maybe if this phenomenon is also described by a pickup maker, you'll start to understand that pseudo science can't explain everything. Remember that the earth was the center of the universe according to science until a guy called Galileo proved science or, better, belief was wrong ... https://d-buz.com/ Ask studio resident Anthony Jackson why is he using the above items and why his hyper high priced basses or his faithful old Precision also have this issue ? That said, the above is a fast and easy solution to these grounding issues. Check also Faraday's work, it will help understanding this phenomenon too. And I think it's time for me to stop helping people, especially when they don't want to evolve or understand that it's not because the majority is wrong that the majority is right. It's only the minority that has made the human kind evolved... Quote Link to comment Share on other sites More sharing options...
Downunderwonder Posted January 24, 2022 Share Posted January 24, 2022 Your link even talks about compensating for bad bridge grounds. Do you have shares in it? Quote Link to comment Share on other sites More sharing options...
Hellzero Posted January 25, 2022 Share Posted January 25, 2022 (edited) 10 hours ago, Downunderwonder said: Your link even talks about compensating for bad bridge grounds. Do you have shares in it? Yes, the link talks about compensating for bad bridge grounding and also a lot of other interesting points that you decided to ignore as well as explanations about the issues of conventional bridge grounding. No, I have no shares in it, but maybe I should. Now I have a question for you : Can you explain how a totally ungrounded body can ground the strings to the electrical network, as it's what the instruments grounding is supposed to do ? Yes, I know the answer. Edited January 25, 2022 by Hellzero Missing quote Quote Link to comment Share on other sites More sharing options...
Downunderwonder Posted January 25, 2022 Share Posted January 25, 2022 5 minutes ago, Hellzero said: Can you explain how a totally ungrounded body can ground the strings to the electrical network, as it's what the instruments grounding is supposed to do ? Is that a trick question? Have at it. I am not an electrician. I don't even know why the strings need to be at ( signal?) ground! All I said was ( grounding everything and everything with ) copper foil fixed the lack of (effective) ground at the bridge ( replacing fingers on strings). I am well aware of Faraday's cage effect. Fingers on strings are not a Faraday cage. Quote Link to comment Share on other sites More sharing options...
Bunion Posted January 25, 2022 Share Posted January 25, 2022 On 24/01/2022 at 09:12, GlamBass74 said: Not the prettiest, but it works a treat! Nice neat job, shame you got hijacked, glad you sorted your problem. 3 Quote Link to comment Share on other sites More sharing options...
FirstBass Posted January 25, 2022 Author Share Posted January 25, 2022 thanks Bunion - i'm chuffed ☺️ Quote Link to comment Share on other sites More sharing options...
Rich Posted January 25, 2022 Share Posted January 25, 2022 (edited) 13 hours ago, Hellzero said: Can't you damn read ? Rule 6: 6. Your Conduct. You also explicitly agree that you shall not: ( a ) provide any content or conduct yourself in any way that may be construed as; unlawful, illegal, threatening, harmful, abusive, etc In other words: play nicely. This is not open for negotiation. Edited January 25, 2022 by Rich 3 Quote Link to comment Share on other sites More sharing options...
rmorris Posted January 25, 2022 Share Posted January 25, 2022 Okay. The discussion on this topic has become ridiculous. No need to talk of "pseudo-science" and people evolving. So - shielding - Copper/Aluminium (as commonly used) shielding is effective in rejecting "rf mush" when it is held at a low impedance voltage. In practice this means connecting it to "Ground". More precisely the "0V reference" of the system. If using an "Earthed" amp etc (ie it has a three wire mains cord) then this is also "Earth". But it isn't always the case - consider battery powered systems or electronic systems on an aeroplane... Ideally the shield is continuous. In practice it never is (well those wires need to get in/out 🙂) but the more complete the better the shielding (basically - there are other considerations when you really get into it !) Grounding the bridge - and hence the strings if they are metal - has a different, though associated, purpose. That purpose is to "ground" YOU - the player. Yes - you are being "Grounded" by the bass/amp setup. You are NOT grounding the bass - since you are (generally) not grounded yourself. And the shielding on the bass is already "grounded". What is happening is that you are acting as a great big antennae and picking up / transmitting rf noise to the bass. Shielding will help with this but it will still be picked up from the pickups in general. Now, when you touch the grounded metalwork then you are being held at a fixed potential and the transmission is effectively halted. It can be demonstrated in the right circumstances - get a situation where you are picking up significant rf noise. Moving your hand(s) nearer the pickups will increase the noise level until you actually touch the string. To put it another way - if you (ie the player) were not near the electronics then the noise would essentially not be there ! 4 1 Quote Link to comment Share on other sites More sharing options...
Hellzero Posted January 25, 2022 Share Posted January 25, 2022 Thanks @rmorris, I'm glad somebody else explained this phenomenon, that has nothing to do with a missing or forgotten bridge grounding as it's there. That said people still have to evolve as well as science that doesn't have all the answers. So thanks again for your crystal clear explanations, hoping the missing bridge grounding believers won't stone you for heresy. 😉 And I really should stop telling bullsh*t instead of giving a correct answer when I'm fed up, but it's too late to change (me). Quote Link to comment Share on other sites More sharing options...
Downunderwonder Posted January 25, 2022 Share Posted January 25, 2022 1 hour ago, rmorris said: What is happening is that you are acting as a great big antennae and picking up / transmitting rf noise to the bass. Shielding will help with this but it will still be picked up from the pickups in general. Now, when you touch the grounded metalwork then you are being held at a fixed potential and the transmission is effectively halted. You're saying the player acts as a big antenna into the bass electronics when he isn't connected to them? But when he is connected to them he stops transmission? No comprendez. Quote Link to comment Share on other sites More sharing options...
rmorris Posted January 25, 2022 Share Posted January 25, 2022 21 minutes ago, Downunderwonder said: You're saying the player acts as a big antenna into the bass electronics when he isn't connected to them? But when he is connected to them he stops transmission? No comprendez. Basically yes. Because when the player (of any sex or gender !) contacts the grounded metal then they are held at the same electrical potential as the "Ground" potential. If the question is why the player is held very near to "ground" rather than than the rf voltage then you have to look at the relevant impedances. It does get a bit technical 😳 But bear in mind that these concepts and models are well understood in electronics in general. There is no special branch of electronics for basses (or even guitars 😄) 1 Quote Link to comment Share on other sites More sharing options...
Downunderwonder Posted January 26, 2022 Share Posted January 26, 2022 Back it up please. Ime an antenna only works when it is in electrical contact with the receiving device. Quote Link to comment Share on other sites More sharing options...
rmorris Posted January 26, 2022 Share Posted January 26, 2022 5 hours ago, Downunderwonder said: Back it up please. Ime an antenna only works when it is in electrical contact with the receiving device. No. This is well known and demonstrable stuff. Transmitting antennae are clearly not in contact with the receiving device. The receiving antenna in this case is the bass pickup etc. 1 Quote Link to comment Share on other sites More sharing options...
Downunderwonder Posted January 26, 2022 Share Posted January 26, 2022 35 minutes ago, rmorris said: No. This is well known and demonstrable stuff. Transmitting antennae are clearly not in contact with the receiving device. The receiving antenna in this case is the bass pickup etc. So the bassist is a re broadcast station for local RF? Not buying it. Quote Link to comment Share on other sites More sharing options...
rmorris Posted January 26, 2022 Share Posted January 26, 2022 3 minutes ago, Downunderwonder said: So the bassist is a re broadcast station for local RF? Not buying it. Ok. As you please. I'm not coming out with anything original here. There's no real mystery. Quote Link to comment Share on other sites More sharing options...
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