zeop
Rookie Solder Flinger
Posts: 2
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Post by zeop on Jan 13, 2006 17:17:13 GMT -5
Hi, I am new here and new to wiring/rewiring guitars. I have a musicman sub1 that I have shielded, but I have a few questions/concerns. First, the musicman has a metal pickguard. I am trying to isolate the signal ground from the shielding ground but there is no way to do that with metal screws contacting the pups. Second, I pulled the pups out, and left them dangling and connected the amp, and there is still hum. I have tried 2 other guitars (both dual humbuckers - both factory - no shielding) and there is much less hum than on this one. (I have checked the output jack and it is correctly wired) Anyone have any ideas? Pictures located here : www.beach-glass-jewelry.com/images/guitarwww.beach-glass-jewelry.com/images/guitar(pictures are large) Any help is appreciated.... Phil
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Post by fenderstrats on Jan 16, 2006 20:08:22 GMT -5
Have no probms with my strat .Maybe the noise is due to not having the pup cavities shielded.Try wrapping the pups in aluminum foil to see if they quiet down( pulled out) ...if so thats the prob.then shield the cavaties.If not put some electrical tape under the tabsan any part of the pu that micht touch the guard .Although your wiring looks very good check for wires that might be touching the pick guard I had a strand of coax brade that barely was touching the guard.Also if youre working in an area where you have a dimmer light switch turn off the light ...thats the worst thing for any electronics. Hope this can help
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Post by wolf on Jan 16, 2006 23:44:38 GMT -5
That is a nice looking guitar. (I surfed the Internet to see the entire guitar). Anyway, is the only thing you have done is shielding it? (Quieting the Beast as John Atchley calls it). How was the hum before you did the shielding?
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zeop
Rookie Solder Flinger
Posts: 2
Likes: 0
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Post by zeop on Jan 17, 2006 0:14:47 GMT -5
Thanks for the feedback - the black you see inside the cavities is shielding paint.
The problem is that the top of the pickguard is also metal - so I am contemplating putting a nylon washer under the pup, or better yet, replace the pickup screws with nylon ones.
The hum is directional - like something is acting as an antenna - if I turn to face the amp it seems to quiet down to almost no hum, but when I move around it gets loud.
I changed the pickups to Seymour Duncan SH-4 in the bridge and the SH-2N in the neck - I also replaced the pots with 500k instead of 250k. It sounds sweet...but has the dreaded hum.
The hum is the same as before I shielded it I think. It is hard to tell - I use a fender hotrod deville 410 and there is no low volume on it (lol)
I guess the question is this.... I have the pickups grounded to the metal of the pickup guard (signal return) and also to the common star ground via the shielding (0 ohms measured from pup shielding to pup metal chasis)
I think this is causing a ground loop. Is that correct?
Has anyone ever tried using nylon screws to mount their pickups? Does anyone know where to get nylon screws to mount the pickups?
Thanks....
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Post by wolf on Jan 17, 2006 1:47:32 GMT -5
I think the problem might be the way the Seymour Duncan pickups are wired. If I might be permitted to post some sacrilege - I have never used the quieting the beast modification on any of my guitars. I've found using humbuckers or using 2 single coils with 1 of those being Reverse Wired Reverse Polarity reduces a LOT of hum and I feel that using shielding paint or worrying about ground loops is going a bit overboard. I believe other members here have made postings concerning whether ground loops create any more hum than if you had chosen star grounding. I would seriously recheck the pickup wiring before you start worrying about insulated washers, nylon screws, etc.
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Post by UnklMickey on Jan 17, 2006 15:17:18 GMT -5
zeop,
i'd like to offer the following comments:
since your pickguard is metal, the copper shielding laminated to it probably is unnecessary. won't hurt anything, just clutters things up.
i think you might do better, running your string ground direct rather than having that connection through the pickguard shield interface tab.
if you think you have a ground loop caused by the pickguard having contact with the pickups, you MIGHT get less hum if you disconnect the outer shield of the pickup cable from the star ground. what is your pickup wiring like? are any of the coils connected directly to the shield? or do you have the "low" connection separate through a wire?
unk
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