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Topic: Have I wired my Wallace Pickup Wrong? |
George Kimery
From:
Limestone, TN, USA
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Posted 11 Feb 2007 2:55 pm |
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| I have a terrible, 60 hz grounding hum in my 12 string Wallace pickup. I just soldered the white, lead cable to the "tip" of a brand new Switchcraft jack and the outer, wrapping to the "sleeve" of the jack. I can't turn the pre-gain on my amp more than 2, or it hums bad. It is an Evans 500 FET Derrell Stephens amp. It is not the cord, it is not being too close to the amp. I have tried other cords, even from other players, that work perfectly. I have tried other guitars and they don't hum at all. I am about to think it is just a bad pickup, although it works fine. Am I missing something on how to connect these things up? My guitar is a PP Emmons, if that should matter. I disconnected the tone control on the guitar just to isolate that as a problem. I really like the pickup, but am wondering now if I should just put my old pickup back in. |
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Brian Edwards
From:
Santa Fe, NM USA
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Posted 11 Feb 2007 3:23 pm
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Let me see if I have this right...you are wiring the lead to the input jack on the guitar? That doesn't sound right to me.
_________________
1971 Emmons PP and Webb 6-14E |
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Brad Sarno
From:
St. Louis, MO USA
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Posted 11 Feb 2007 4:45 pm
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George, I think you did it right. The white wire lead goes to the "tip" connector on the jack. The outer sleeve or black wire goes to the ground or outer (sleeve) connector on the jack.
Did you have a humbucker before? I can't use a single coil in my house. The big transformer on the pole outside causes real bad hum in any single coil here. You may simply be experiencing single coil hum.
Brad
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Brad Sarno
'82 Emmons S-10 push/pull, Revelation Tube Preamp, Furlong SPLIT powered speaker cab, V8 Octal Tube Preamp, Ganz Straight Ahead power amp - JBL D130 |
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Mike Wheeler
From:
Delaware, Ohio, USA
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Posted 11 Feb 2007 5:13 pm
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Hi George,
Sounds to me like a classic cold solder connection on the ground terminal of the jack. The ground terminal can be difficult to solder well because the jack is mounted in the guitar and that acts as a heat sink...pulling the heat away from the terminal.
Here's what I'd recommend...remove the wire from the tab. Now, heat the tab again without the wire attached to it. Apply solder until you see it flow freely. Don't apply a lot, just enough to coat the tab. Now while holding the wire with a needle nose pliers, reheat the tab and when the solder's melted again, press the ground wire onto the tab...still applying the soldering iron to both the tab and wire...until the solder melts on both. Quickly remove the iron while steadily holding the wire to the tab as it cools. Blowing on it helps cool it.
There, you're done. One thing to be careful of is to not apply the iron to the wire for too long a time. You don't want to melt the plastic insulation, and also, use just enough solder to make the connection...no blobs.
Hope this helps.
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Best regards,
Mike |
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Michael Johnstone
From:
Sylmar,Ca. USA
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Posted 11 Feb 2007 8:21 pm
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| I always take the jack out of the guitar before I solder. It's easier to get to things and you don't have the heat sink effect. Before I'd give up or draw any conclusions make sure it's soldered correctly and then take the guitar to some other location and see if it still hums. If it hums all over town,it's soldered correctly and you've taken the cables,volume pedal and amp out of the equation there might be a short in the pickup windings. |
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George Kimery
From:
Limestone, TN, USA
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Posted 12 Feb 2007 5:18 pm Have I wired my Wallace pickup wrong?
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| Thanks for the suggestion about getting a good solder joint. I outsmarted myself when I tried to solder with the jack in the guitar, thinking that it would be easier to hold everything in place that way. The solder joints are not nice and clean and shiney and are a bit too gobbed up. I will take the jack out and re-do. I don't think that is the problem, though. I connected a cord to the original Emmons single coil pickup that is not mounted in the guitar at the present, and I got the same hum. I moved the pickup around, and the hum changed and in certain positions, the hum almost went away entirely. I have it in an old house with old wiring and the place I play at is an old building with old wiring. I am going to take it to my workplace with new wiring and see what happens. I think it is single coil pickup hum in combination with old, non grounded wiring. I appreciate all the help so much. |
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Dick Wood
From:
Springtown Texas, USA
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Posted 12 Feb 2007 8:09 pm
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Well I guess you could have had my problem. My single coil sounded great at my house but at several clubs I played, the hum was almost as loud as the notes.
I had to go back to a Humbucker in the end. |
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Robert Leaman
From:
Murphy, North Carolina, USA
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Posted 15 Feb 2007 5:16 pm Pickup Wiring
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Since signal output from a magnetic pickup is AC, it makes little difference how the output is connected. However, that said, there may be a significant difference between the two connection methods since one of the wires will have greater capacitance to zero voltage common (some call this ground). I always connect the pickup with the black wire on common and the white on the signal output. Then, I reverse the connections and decide which of the two connections produces the least hum. There is no difference in tone except to say that the music signal can be modulated by hum signal frequencies and that can produce some very annoying wolf tones.
Connection reversal produces phase reversal but human ears cannot discern phase. Human ears discern phase modulation as frequency modulation. |
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