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Post by killheart7 on Sept 24, 2010 21:38:09 GMT -5
Hello. I'm working on a somewhat unusual schematic where two humbuckers are wired to two push/pull volume pots for individual volume controls and coil tapping. No tone controls. The problem, as I have labeled in the diagram, is the bare wire coming from the Pro Tubes pickup. When not grounded, the guitar operates, but I get mild hum (as expected) and serious buzzing when my fingers touch the magnets on the Lil' Killer. While touching the magnets, the buzzing goes away if I touch another conductive element on the guitar. When the bare wire is grounded, the Pro Tubes goes into single coil operation regardless of the push/pull pot's mode. As I pick with my fingers often and this guitar is meant for recording purposes, the buzzing is a huge problem. Losing the coil tap function also sucks a lot since that was a big part of my original vision for the build. The really weird part? I have this exact design built elsewhere and it functions perfectly. Dead quiet even under lights, coil taps work perfectly, does not buzz when the magnets are touched, and it is wired identically to this one. The only difference is that the other circuit is using a GFS Loudmouth instead of a Pro Tubes and the positions (bridge/neck) are reversed. I'm lead to believe that this means a problem with one of the humbuckers here. Any thoughts? Thanks for any help with this, I'm slowly losing my mind over it.
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Post by killheart7 on Sept 24, 2010 22:56:18 GMT -5
Ok, so I just did a test by wiring the Pro Tubes to the push/pull pot it's been wired to and then directly to the output jack. The coil tapping malfunction still happens as soon as I ground the bare lead.
I have also switched out the pot with another one I had lying around. Same problem.
Anybody know what's going on here?
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Post by JohnH on Sept 24, 2010 23:19:37 GMT -5
Just a shot in the dark - run-it-up-the-flagpole idea:
Are the connections at the jack socket the wrong way round? (Photo on the diagram suggets they might be)
cheers
John
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Post by killheart7 on Sept 24, 2010 23:35:44 GMT -5
Ah, I wish, but that's just my bad diagraming skills showing themselves. I hurried to put that together and didn't check it too thoroughly, so my apologies for that. That had occurred to me before though, and it was not the problem.
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Post by ashcatlt on Sept 25, 2010 0:22:30 GMT -5
My L'il killers buzz when I touch the blades as well. Of course, mine have 4 conductors and a shield braid, but I don't have the shield braid connected - partly because they're inside a shielded cavity. I suspect this comes from the fact that the blade itself is not grounded. When you touch it, the noise from your finger is injected deep inside the coil, where it can do the most damage. I've noticed the same thing when touching the pole pieces on other pickups here and there as well. I think you'll need to find somewhere else to rest your hand.
The other issue is a little weirder, but I suspect that at least one of the "inside" wires (the ones between the individual coil, making the series connection for that HB) has some damage to its insulation - probably right around where it leaves the pickup itself - and is shorting to the shield braid wrapped around it. The L'il Killer in the Bridge of my strat has a similar issue right now. I've been working up the courage to attempt a fix for something like a year now.
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Post by killheart7 on Sept 25, 2010 0:33:18 GMT -5
I'm also starting to think a short is the problem. The buzz on the Lil' Killer is completely negligible when everything is properly grounded, but obviously that's where I run into the problem. Grounding everything properly defeats the coil tap on the neck pickup. I wonder if GFS would let me send this one in for a replacement... It's worth a shot. I'll let you guys know what the response is.
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Post by killheart7 on Sept 25, 2010 1:20:54 GMT -5
Alright, so I can't find any proof of purchase for that Pro Tubes. I usually keep records like that on hand, but that one slipped through apparently. Since it wouldn't be fair of me to expect a refund without POP, I'm just going to see what happens when I attempt a fix on the pickup myself. Here goes nothing.
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Post by ashcatlt on Sept 25, 2010 7:08:59 GMT -5
It may be too late now, but I'd suggest attempting to prove the short with your meter before tearing the pickup apart.
Guitarfetish customer service is pretty good. If you ordered it over the Internet, there's got to be an electronic record of your transaction somewhere. Did you check your email? I'd say it's worth at least sending them a message.
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Post by newey on Sept 25, 2010 7:25:22 GMT -5
KH- I think Ash is probably on the right track. It sounds like 2 separate problems here. On the Protubes, you might be able to verify that there is a grounding issue by disconnecting the pup and checking it with a meter. It sounds like you'll be de-wiring it anyway, and at least you'll know that you've isolated the problem to the pickup. On the Lil' Killer, I also have one of those in one of my guitars and, while it's been a few years since I put it in, I'm sure I'd remember if it was a 3-wires-plus-bare deal. Did the GFS instructions say that the bare wire substituted for the black wire? Maybe they've changed things around since I bought mine, but I could swear mine was the standard 4-wire plus shield configuration. While you state that the Lil' Killer has the bare wire instead of the black wire, your diagram seems to indicate that it is the green wire that's not there on that pickup. So I was a bit confused by that as well. EDIT:Ash got to the meter suggestion before I did! Ninja'd!
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Post by wolf on Sept 25, 2010 21:39:46 GMT -5
Yeah, it seems to me that it's the green wire that's missing from the Li'l Killer. The green wire is the hot wire and I can't see how that bare wire is taking the green wire's place. Also, Guitar Fetish seems to have the least published information on their pickup wire color codes. From what I could determine, their humbucker wire codes are: Green + White - Red + Black -
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Post by newey on Sept 25, 2010 22:01:11 GMT -5
GFS wire colors are the same as SD wire colors. Here's a copy of the insert that comes with every GFS pickup I've ever bought- it's the same sheet, covers all their pickup types: Wolf- Note that red is negative, white is positive, according to the sheet.
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Post by killheart7 on Sept 25, 2010 22:18:00 GMT -5
Thanks everybody. I took apart the pickup last night and fixed the short. The wire was pulled through the baseplate too tightly and caused the edge of the plate to cut into it. A little electrical tape solved the problem. For those interested, both of the Lil' Killers are the same way: red, white, green, and bare wires only. Maybe it's only the calibrated sets that come that way, I don't know, but that's how they are.
Thanks again.
-Justin
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Post by wolf on Sept 25, 2010 23:59:31 GMT -5
Thanks for posting that newey. Okay I came up with a graphic: Well it seems GFS uses Seymour Duncan's wire colors but the polarities seem to be opposite and the South North designations seem to be opposite too.
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Post by newey on Sept 26, 2010 0:40:54 GMT -5
Hmmm. Right you are!
As I read it again, it actually says: "GFS Humbuckers may also be wired using Seymour Duncan wiring codes"- which is not the same as saying the colors are the same as SDs!
But if the polarities are opposite and the N and S coils are opposite, then one could use SD wiring diagrams to wire them, and get the same results, presumably. They would just be wired "inside out", as Wolf calls it.
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Post by ashcatlt on Sept 26, 2010 12:03:46 GMT -5
Thanks everybody. I took apart the pickup last night and fixed the short. The wire was pulled through the baseplate too tightly and caused the edge of the plate to cut into it. A little electrical tape solved the problem. For those interested, both of the Lil' Killers are the same way: red, white, green, and bare wires only. Maybe it's only the calibrated sets that come that way, I don't know, but that's how they are. Thanks again. -Justin That's the same problem I've got, only it seems to be both the green and black wires, since when it shorts out it kills the entire guitar. Glad to hear it was an easy fix. My L'il Killers came as a set and quite definitely have 4 conductors plus shield. When did you get yours? Have they changed something recently?
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Post by wolf on Sept 26, 2010 13:01:38 GMT -5
newey It's not an "inside-out" wiring the way I define it.
Green + Red - White + Black -
Now, turning that "inside-out" it becomes:
Red - Green + Black - White +
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Post by sumgai on Sept 26, 2010 18:53:27 GMT -5
wolf, Re-arranging the order of how you present the wires doesn't change anything else, only the appearance on the page. Inside out means that the start/finish or the positive/negative designations have been swapped, per wire color. But in the grand scheme of things, it really doesn't make any difference how they're labeled. So long as the wires are connected, one is going to achieve either in-phase or out-of-phase. Knowing ahead of time which way is which is a bonus, but not mandatory - the odds of getting it right the first time are exactly 50-50. The odds of fixing it so it's correct afterwards increase dramatically. HTH sumgai
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Post by newey on Sept 27, 2010 0:49:44 GMT -5
Ash noted:
I checked mine in the Esquire-ish git, and as I remembered, it's a 4-wire plus shield. And mine wasn't in a set, just a single pup.
Also, when one does see, on occasion, a 3-wire (plus shield) HB, the shield is still just a shield. One of the 3 insulated wires is usually the "series junction", joining the 2 coils internally- which is not how Killheart has his wired.
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Post by killheart7 on Dec 4, 2010 0:57:30 GMT -5
Hello...really late reply here. I was just browsing and noticed that ashcatlt left a question I never saw. I got my Lil' Killers from a guy on eBay earlier this year, so I don't know when they were manufactured or anything like that. From the reactions here it sounds like mine are some form of oddity, but I haven't got a clue as to the explanation. Sorry.
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