#1
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Guitar Jack Grounding Problem
I had a gig yesterday and all was fine, but when I set my gear up at home this morning, my B-Band pickup-equipped Guild suddenly has a grounding issue. I get a loud whine unless I touch the cable end. This happens with any cable so I'm thinking something came loose inside. I've never installed a pickup myself so wouldn't know what to look for. Any suggestions would be appreciated.
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1967 Aria Classical 1974 Guild D50 2009 Kenny Hill New World Player Classical 2009 Hoffman SJ 2011 Hoffman SJ 12 https://paulashley.weebly.com/ https://www.youtube.com/c/PaulAshley https://www.reverbnation.com/paulashley Last edited by lpa53; 03-24-2019 at 09:03 AM. |
#2
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Have you tried more than one guitar?
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jf45ir Free DIY Acoustic Guitar IR Generator .wav file, 30 seconds, pickup left, mic right, open position strumming best...send to direct email below I'll send you 100/0, 75/25, 50/50 & 0/100 IR/Bypass IRs IR Demo, read the description too: https://youtu.be/SELEE4yugjE My duo's website and my email... [email protected] Jon Fields |
#3
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I've only been retired from my tech-nerd days for a few years and already my troubleshooting skills are going! You're right and just now I changed the thread title. It only happens on my Guild so it appears it's a problem in the signal chain of the pickup somewhere. I've never installed a pickup so wouldn't know what to look for.
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1967 Aria Classical 1974 Guild D50 2009 Kenny Hill New World Player Classical 2009 Hoffman SJ 2011 Hoffman SJ 12 https://paulashley.weebly.com/ https://www.youtube.com/c/PaulAshley https://www.reverbnation.com/paulashley |
#4
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More likely, I would suspect the UST element itself. I had a 20+ year old Fishman develop a super intermittent ground buzz. One day I plugged in and it was dead. Unless a wire got knocked around somehow, you may be looking at a just-starting-to-fail pickup.
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-Gordon 1978 Larrivee L-26 cutaway 1988 Larrivee L-28 cutaway 2006 Larrivee L03-R 2009 Larrivee LV03-R 2016 Irvin SJ cutaway 2020 Irvin SJ cutaway (build thread) K+K, Dazzo, Schatten/ToneDexter Notable Journey website Facebook page Where the spirit does not work with the hand, there is no art. - Leonardo Da Vinci |
#5
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Do you know which B-Band model you've got (so I can look it up)?
The easiest thing to do is to see if it is installed using pluggable connectors. If so I would remove and reseat all of them. Next I would suspect the UST, if it's got one. Non-coaxial USTs are known for developing ripped shields and starting to hum. The Fishman Matrix is famous for this, though probably more so for how many have been manufactured than something weak in their design. Coax based USTs are built from (usually flattened) coax piezo material that is put into asphalt for letting traffic lights know if a car has passed by. Prior to flattening that material is pretty bullet proof. After flattening it is still more robust than the non-coax USTs, but sometimes prone to failure where it bends entering the saddle slot.
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jf45ir Free DIY Acoustic Guitar IR Generator .wav file, 30 seconds, pickup left, mic right, open position strumming best...send to direct email below I'll send you 100/0, 75/25, 50/50 & 0/100 IR/Bypass IRs IR Demo, read the description too: https://youtu.be/SELEE4yugjE My duo's website and my email... [email protected] Jon Fields |
#6
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I've searched the web for a B-Band site but have come up empty.
__________________
1967 Aria Classical 1974 Guild D50 2009 Kenny Hill New World Player Classical 2009 Hoffman SJ 2011 Hoffman SJ 12 https://paulashley.weebly.com/ https://www.youtube.com/c/PaulAshley https://www.reverbnation.com/paulashley Last edited by lpa53; 03-25-2019 at 09:42 AM. |
#7
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OK, now that we know this is a dual source, is there any difference in hum between UST only and AST/SBT only?
If not, and following on the possibility that you dislodged a wire, can you view inside the guitar and see if there is a loose wire at the endpin jack?
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-Gordon 1978 Larrivee L-26 cutaway 1988 Larrivee L-28 cutaway 2006 Larrivee L03-R 2009 Larrivee LV03-R 2016 Irvin SJ cutaway 2020 Irvin SJ cutaway (build thread) K+K, Dazzo, Schatten/ToneDexter Notable Journey website Facebook page Where the spirit does not work with the hand, there is no art. - Leonardo Da Vinci |
#8
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If that does not do the trick, I think it makes more sense to swap the entire system out for something still in production. If you check the current AGF threads you find many good options with strong proponents.
__________________
jf45ir Free DIY Acoustic Guitar IR Generator .wav file, 30 seconds, pickup left, mic right, open position strumming best...send to direct email below I'll send you 100/0, 75/25, 50/50 & 0/100 IR/Bypass IRs IR Demo, read the description too: https://youtu.be/SELEE4yugjE My duo's website and my email... [email protected] Jon Fields |
#9
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you said it happened after you pulled out the cord.
Are you usingbthe same cord. Try another cord. just to illiminate a cord problem. |
#10
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First off, standard 1/4" mono jacks don't have a "hot" and "neutral." I was an electronics technician in the USN for 14 years. I've done a lot of pickup installation, amp repair and cable makeup/repair.
Your jack on your guitar should have an insulated signal lead(s) coming from your pickup(s). On your B-band the pickup goes to a preamp, and the preamp leads go to your output jack. Signal lead should be soldered to the tip terminal. The ground is usually a bare copper shield, twisted up, tinned and soldered to the ring terminal. Again, the leads coming from your B-band preamp may be different. A good installer will insulate both jack terminals with heat shrink to make sure they don't ever get any dirt, dust or moisture providing any connection between them. In a standard round soundhole guitar its not too hard to take off the strings and loosen the output jack so you can pull it back out and look. The pickup end could also be where the problem is, though most piezo pickups we use come with the piezo connection(s) already made and sealed. Is your B-band the UST one? If so, there is a chance the constant pressure of the string force pushing the saddle down on your piezo element has finally worn through? One reason I prefer SBT's over UST's. If yours is the model where the band mounts under the bridge this shouldn't be a problem. You should also check the connection from the band element to the preamp. Could be something has gone wrong within the black-box (non-repairable) preamp. That's one reason why I like external preamps too. |
#11
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While poking around inside in the wake of the many good suggestions, I fell into a "solution" of sorts. As I mentioned before, the loud hum would disappear when I touched the metal at the jack or cable tip. I found it would also dissipate somewhat when I touched the small connections on the soundhole controls. Then I reached inside and very lightly touched the metal cover of the main electronics box and the hum disappeared. And when I removed my finger, the sound was entirely gone, and has stayed gone since. Was this just some buildup of static electricity? Who knows. Oh, well ... false alarm.
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1967 Aria Classical 1974 Guild D50 2009 Kenny Hill New World Player Classical 2009 Hoffman SJ 2011 Hoffman SJ 12 https://paulashley.weebly.com/ https://www.youtube.com/c/PaulAshley https://www.reverbnation.com/paulashley |
#12
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Welcome to the world of electronics troubleshooting and repair.
The dreaded intermittent problem! |
#13
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And more than likely to return at a most inopportune time. murphy strikes again. |
#14
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__________________
jf45ir Free DIY Acoustic Guitar IR Generator .wav file, 30 seconds, pickup left, mic right, open position strumming best...send to direct email below I'll send you 100/0, 75/25, 50/50 & 0/100 IR/Bypass IRs IR Demo, read the description too: https://youtu.be/SELEE4yugjE My duo's website and my email... [email protected] Jon Fields |