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 Post subject: Grounding issues
PostPosted: Mon Mar 13, 2017 7:19 pm 
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First name: Bob
City: Kurtistown
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So, I'm able to figure out electronic grounding issues normally. I'm wondering if there is a reliable way to determine on a old guitar if the pickup itself is the problem? Can the an old pickup, or a new one for that matter, cause a ground hum without being actually shorted out? Thanks, Bob

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 Post subject: Re: Grounding issues
PostPosted: Tue Mar 14, 2017 11:14 am 
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Pegasusguitars wrote:
So, I'm able to figure out electronic grounding issues normally. I'm wondering if there is a reliable way to determine on a old guitar if the pickup itself is the problem? Can the an old pickup, or a new one for that matter, cause a ground hum without being actually shorted out? Thanks, Bob

Absolutely, I think most hums are not caused by grounding actually. What year guitar/pickup? Many pickups go through wax potting to minimize hum, but older pickups may not have much wax left, especially if they've been handled a lot. You can wax dip it yourself and that may help. Also, 60 cycle hum is normal for a single coil pickup (hence the reason humbuckers were invented). Nearby electronics can also get picked up through the pickups as hum. I assume the wiring in your house is good? Aside from the pickups, your pots and caps could be causing it. Look for cold solder joints or loose grounds in the bridge, switches, and other hardware.

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 Post subject: Re: Grounding issues
PostPosted: Tue Mar 14, 2017 11:17 am 
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John Elshaw wrote:
Pegasusguitars wrote:
So, I'm able to figure out electronic grounding issues normally. I'm wondering if there is a reliable way to determine on a old guitar if the pickup itself is the problem? Can the an old pickup, or a new one for that matter, cause a ground hum without being actually shorted out? Thanks, Bob

Absolutely, I think most hums are not caused by grounding actually. What year guitar/pickup? Many pickups go through wax potting to minimize hum, but older pickups may not have much wax left, especially if they've been handled a lot. You can wax dip it yourself and that may help. Also, 60 cycle hum is normal for a single coil pickup (hence the reason humbuckers were invented). Nearby electronics can also get picked up through the pickups as hum. I assume the wiring in your house is good? Aside from the pickups, your pots and caps could be causing it. Look for cold solder joints or loose grounds in the bridge, switches, and other hardware.

Sent from my SAMSUNG-SM-G935A using Tapatalk

One more thing, unplug the guitar completely and listen if you still hear the hum to rule out amp issues.

Sent from my SAMSUNG-SM-G935A using Tapatalk


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 Post subject: Re: Grounding issues
PostPosted: Tue Mar 14, 2017 12:15 pm 
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First name: Bob
City: Kurtistown
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Country: USA
John,-Thanks. I am pretty much aware of all that stuff, but appreciate the reminders. I use single coils in the lap steels I make so I know they can be noisy. Because I am slowly becoming the local lap steel guy, after 40+ years of acoustic building and repair, people are starting to bring me a few steels with problems. Old lap steels are all over the map in terms of pickups and some of the crappiest wiring and components you'll ever see. Most of the components are fairly easy to check, but the pickups themselves are more difficult. I'm just starting to learn about making my own pickups and doing the potting, so I will take the repotting idea into account. Thanks, Bob

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