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Tapewounds causing electrical hum

T

tkozal

Feb 16, 2006
1,283
38
New York City
#1
So I put a set of LaBella Tapewounds on My Fender Jaco Jazz Fretless. I have been trying all sorts of flatowunds and such on my basses lately. Well, the Jaco has the classic hum without both pups full on, but now it hums all the time (a slightly different hum). When I touch the metal of the knobs or bridge, it stops. I assume I have an issue somewhere. Do I need to run a ground from somewhere, or have some metal from the string contact the metal on the bass somewhere?

Thanks
 
#4
You don't have a grounding issue you have a shielding issue. I had to shield my Jaco as it hummed quite fierce. A proper shielding job will remove the hum, the little strips of brass they put in the control and pickup cavities does nothing.

If your hum gets louder when you touch strings/metal/bridge it is a grounding issue, if it goes away it is a shielding issue. Simple diagnosis.
 
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#6
DiabolusInMusic said:
You don't have a grounding issue you have a shielding issue. I had to shield my Jaco as it hummed quite fierce. A proper shielding job will remove the hum, the little strips of brass they put in the control and pickup cavities does nothing.

If your hum gets louder when you touch strings/metal/bridge it is a grounding issue, if it goes away it is a shielding issue. Simple diagnosis.
Click to expand...

Thanks, but shield it how? In the control cavity, or pups area also?
 
#7
Come on guys, this is easy. The tapewounds don't allow him to complete the ground. The buzzing stops when he touches the bridge or knobs.

There is a wire that runs from the control cavity ground to the beneath the bridge. It's meant to allow that electrical "noise" that is picked up by your guitar to be dissipated into your body.

The surface of the tapewounds are not conductive. So touching the strings doesn't eliminate the noise. That's why touching the bridge or metal knobs still stops the noise.
 
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#8
tbplayer59 said:
Come on guys, this is easy. The tapewounds don't allow him to complete the ground. The buzzing stops when he touches the bridge or knobs.

There is a wire that runs from the control cavity ground to the beneath the bridge. It's meant to allow that electrical "noise" that is picked up by your guitar to be dissipated into your body.

The surface of the tapewounds are not conductive. So touching the strings doesn't eliminate the noise. That's why touching the bridge or metal knobs still stops the noise.
Click to expand...

Finally a voice of reason :D My D'addarios do the same thing. If you're recording, you could wear a conductive bracelet with a wire connected to either the bridge or the tuning peg, whichever one is the least of a pain in the ***, but I agree, the noise with tapes can be a pain in the ***..........
 
#9
So what do I do if I don't wear jewelry?


photo2_zps4ca6d0a0.jpg
 
#10
OP, you need to shield the control cavity, pickup cavity, and pickup covers and then ground them all together.

Wearing some kind of jewelery or some other stuff is just ridiculous... just fix the bass and the problem goes away. Yes, outside interference causing hum is an issue that should be treated as such.

I just pulled out my Jaco, it has been getting neglected in its case for the last month or so. Turns out my electronics have quit on me somewhere as I am getting no output but this thing was dead silent with flats on it before I put it in it's case, so this is a proper shielding job. I didn't remove the pickup covers but they are covered on the inside and you can see the outside wrap where the ground wire gets connected.
 

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#11
DiabolusInMusic said:
OP, you need to shield the control cavity, pickup cavity, and pickup covers and then ground them all together.

Wearing some kind of jewelery or some other stuff is just ridiculous... just fix the bass and the problem goes away. Yes, outside interference causing hum is an issue that should be treated as such.

I just pulled out my Jaco, it has been getting neglected in its case for the last month or so. Turns out my electronics have quit on me somewhere as I am getting no output but this thing was dead silent with flats on it before I put it in it's case, so this is a proper shielding job. I didn't remove the pickup covers but they are covered on the inside and you can see the outside wrap where the ground wire gets connected.
Click to expand...

Thanks, but I think for now I will put a metal flatwound on, and bag these labellas for awhile. I wouldn't do such work myself, and its gonna be awhile till I can get it to Matt at 30th street

Thanks again
 
#12
OP - It's not a shielding issue, not that shielding wouldn't help. Put the old strings back on and you will see what I mean.

These instruments are designed to use the player as a ground to shunt spurious electrical noise. I can't see for certain, but on the last poster's pics, even with the shielding, the bridge is grounded. The player is supposed to be connected to ground.
 
#13
DiabolusInMusic said:
Turns out my electronics have quit on me somewhere as I am getting no output but this thing was dead silent with flats on it before I put it in it's case, so this is a proper shielding job.
Click to expand...

The OP isn't talking about flatwounds, he's using tapewounds. The surface is insulated. There's a huge difference when it comes to shunting extraneous electrical noise.
 
#15
tkozal said:
Thanks, but I think for now I will put a metal flatwound on, and bag these labellas for awhile. I wouldn't do such work myself, and its gonna be awhile till I can get it to Matt at 30th street

Thanks again
Click to expand...

Don't fret about doing shielding yourself, it is extremely easy. I am far from a professional technician, as you can see my tape job. Quite frankly, you are paying somebody a premium rate to put in some tape and make a couple extremely easy solder points. It is your money at the end of the day, but this is one job I recommend people do.

TBplayer, his string choice is irrelevant here. The issue is a shielding issue, he can fix the issue so it doesn't occur period, regardless of string choice. Of course it is grounded, if it wasn't grounded and the OP touched metal his buzz would get louder, not go away. My Jaco (when working) doesn't hum even with no strings on it.

OP if you shield the bass it won't hum period. Touching the strings/metal/bridge will have no effect on a properly shielded bass.
 
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#17
No. On a jazz you have to run an individual wire to each cavity, I brought them all to a common point, you can barely see it under where the jack would rest in the control cavity. In the picture the cloth wires are from Fender and the rubber is added by me.

The added wires coming from the control cavity are actually grounded to the pickup surrounds not the cavities. I left the copper plates that Fender had installed in each cavity and just ensured the plates made contact with the copper shielding, that is how the cavities are grounded on this particular bass.
 
#20
DiabolusInMusic said:
TBplayer, his string choice is irrelevant here. The issue is a shielding issue, he can fix the issue so it doesn't occur period, regardless of string choice. Of course it is grounded, if it wasn't grounded and the OP touched metal his buzz would get louder, not go away. My Jaco (when working) doesn't hum even with no strings on it.

OP if you shield the bass it won't hum period. Touching the strings/metal/bridge will have no effect on a properly shielded bass.
Click to expand...

When you shielded your bass, which is always a good thing, did you remove your bridge ground wire?
 

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