Wired my First Jazzmaster Today

For help with setups and other technical issues.
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Bradley-Jazz
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Re: Wired my First Jazzmaster Today

Post by Bradley-Jazz » Fri Oct 09, 2020 12:35 pm

I’d expect to hear a pop or something like that when tapping a pickup with a screwdriver, but you’re getting it at other times, yes?

I’m not sure how the pickups could hold charge really - they are connected to ground. Are the covers grounded (check with a meter)? - they should be. I suppose if they have lost that connection they might...? Are the pickups solid - I.e, Are the covers loose and move relative to the bobbins?
Stop me if you think you've heard this one before....

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j mascis
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Re: Wired my First Jazzmaster Today

Post by j mascis » Fri Oct 09, 2020 2:00 pm

Bradley-Jazz wrote:
Fri Oct 09, 2020 12:35 pm
but you’re getting it at other times, yes?
Yeah. I wiped the pickguard with Windex and it went away for a while, then came back.
It must be the pickguard/pickups getting a charge for some reason. I read about this online and people say to use dryer sheets to discharge it.
I'm also wondering if this is from shielding the wood inside the cavity but not doing the pickguard (i thought it wasn't necessary due to using humbuckers...originally i was going to put single coils in the guitar, so I had covered the wood with copper tape). Maybe doing half created some crazy scenario in there with half shielded and half not. All grounds test great and the guitar is dead quiet when sitting. The crackles/pops come when striking notes. Like when the pick hits the string. I thought that would be a ground, but the multimeter shows all grounds are as they should be.

I think I will try that dryer sheet trick, and if that doesn't work either shield the entire thing in copper or rip out the copper that's in there. If anyone has other ideas let me know!

Thanks, guys. This thread got the guitar where I wanted it otherwise.

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Bradley-Jazz
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Re: Wired my First Jazzmaster Today

Post by Bradley-Jazz » Fri Oct 09, 2020 2:26 pm

The strings are grounded aren’t they? There should be a ground wire either from the trem cavity into the control cavity, or from one of the bridge thimbles into the control cavity, and that should be soldered to any convenient ground (often back of vol pot). I suppose it is possible that it is loose against the thimble or trem plate (if you have one in there it should be bent up to be trapped under the top trem plate when screwed down),

You could check continuity to ground from the strings, and if apparently ok, crocodile clip the multimeter lead to a string behind the bridge, then hit the strings and see if continuity is intermittent. Might be a long shot but an easy test....
Stop me if you think you've heard this one before....

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j mascis
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Re: Wired my First Jazzmaster Today

Post by j mascis » Fri Oct 09, 2020 3:22 pm

Bradley-Jazz wrote:
Fri Oct 09, 2020 2:26 pm
The strings are grounded aren’t they? There should be a ground wire either from the trem cavity into the control cavity, or from one of the bridge thimbles into the control cavity, and that should be soldered to any convenient ground (often back of vol pot). I suppose it is possible that it is loose against the thimble or trem plate (if you have one in there it should be bent up to be trapped under the top trem plate when screwed down),

You could check continuity to ground from the strings, and if apparently ok, crocodile clip the multimeter lead to a string behind the bridge, then hit the strings and see if continuity is intermittent. Might be a long shot but an easy test....
Hey Bradley. I put the red multi-meter connector into the output jack, and then tested each string. All went to 0. So I think they're grounded properly. I tested every component using that method and all read 0.

I grounded the trem plate, but didn't really read up on it. So maybe what I did is an issue. I put a small piece of wire under the plate, and that is pinched down into the wood by the plate. The other end I grounded to a ball of solder on the copper tape. Not to a pot or anything. Just to a blob of solder on the tape (under that is wood). Would that cause the issue? Maybe it should go to a pot instead. It read as 0 when I do the multimeter test on it, so I assumed it was an ok ground.

Edit: after more testing...it's definitely the pickguard. Rubbing my fingers on it causes major static. The only reason I thought it was maybe hitting the pick to the strings is that I sometimes touch the pickguard when picking, causing it to happen.

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j mascis
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Re: Wired my First Jazzmaster Today

Post by j mascis » Fri Oct 09, 2020 7:02 pm

So this is the exact issue: https://www.youtube.com/watch?v=h2gYcAuTdjk

Weird. I've played guitar for decades and never ran into this until building this one.
I guess I have to add copper tape to the inside because the dryer sheet only lasts a few months.

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Bradley-Jazz
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Re: Wired my First Jazzmaster Today

Post by Bradley-Jazz » Sat Oct 10, 2020 12:34 am

Great - looks like you’ve nailed it! If you’ve continuity from strings through the shielding to ground, that’s all good.

Maybe that pickguard has a different formulation of plastic that is more static-prone? Anyway, I’d shield that and make sure the guard shield electrically contacts something else grounded (eg the pots bolted to it). It’s probably worth buying a packet of drier sheets anyway - they last ages in my experience.
Stop me if you think you've heard this one before....

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j mascis
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Re: Wired my First Jazzmaster Today

Post by j mascis » Sat Oct 10, 2020 1:23 pm

Very happy to report after shielding the pickguard with copper tape, there's no static.
Guitar is dead quiet now and doing exactly what I wanted it to do.

Only thing now is the 1meg pots in the rhythm circuit don't sound much different than the 500k in the main, so I'm wondering what the best values would be for separation. If anyone has suggestions let me know. WRHB pickups. .022 cap in main and .047 cap in rhythm (maybe lower this one so it's a bright switch?).

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