Jump to content
Why become a member? ×

Crackle from the bridge pickup of a Jazz bass


Clarky
 Share

Recommended Posts

Prior to putting my 73 Jazz up for sale I had the Bass Gallery re-install the original pickups and do a set-up. I had not played it on an amp until yesterday when I discovered (right in the middle of my eBay auction :) ) that the bridge pickup crackles. There is no issue at all with the neck pickup and when I play with both pickups engaged the crackle disappears if I drop the volume on the bridge pickup by about an eighth of a turn of the control knob.

Does this sound like a shielding issue (as in copper tape in the control cavity will fix it simply and cheaply) to you Jazz experts? Or is it likely something else?

Thanks all

Edited by Clarky
Link to comment
Share on other sites

Hi Clarky, what kind of crackling noise are you getting? Does the signal from the bridge PUP cut in and out at the same time, or is it more of a background interference kind of thing?

Before you try anything drastic, get the control plate off and spray some switch cleaner directly into the bridge PUP volume pot casing (use some kitchen paper towel to soak up the excess trickling out as you do so), and give the knob several full turns in both directions. Also check that the solder joints to the pot are making a good connection.

Hope this helps mate!

Etienne :)

Link to comment
Share on other sites

[quote name='Etienne' post='794978' date='Apr 3 2010, 12:28 PM']Hi Clarky, what kind of crackling noise are you getting? Does the signal from the bridge PUP cut in and out at the same time, or is it more of a background interference kind of thing?

Before you try anything drastic, get the control plate off and spray some switch cleaner directly into the bridge PUP volume pot casing (use some kitchen paper towel to soak up the excess trickling out as you do so), and give the knob several full turns in both directions. Also check that the solder joints to the pot are making a good connection.

Hope this helps mate!

Etienne :)[/quote]
Thanks Etienne! Its more of a background interference type noise, like a hissing/crackling when that pickup is selected and on full.

Link to comment
Share on other sites

[quote name='Clarky' post='794982' date='Apr 3 2010, 12:33 PM']Thanks Etienne! Its more of a background interference type noise, like a hissing/crackling when that pickup is selected and on full.[/quote]

Does it happen only when you turn the knob? Or constantly?

Link to comment
Share on other sites

[quote name='Clarky' post='794982' date='Apr 3 2010, 12:33 PM']Thanks Etienne! Its more of a background interference type noise, like a hissing/crackling when that pickup is selected and on full.[/quote]

I suspect it's down to the pot rather than the PUP, particularly if the neck pickup is behaving itself (save the usual 60-cycle hum when soloed of course). Let me know if there's any improvement after trying the switch cleaner!

Link to comment
Share on other sites

[quote name='Etienne' post='794992' date='Apr 3 2010, 12:45 PM']+1. Forgot to ask that myself![/quote]
Nope, its constant

Edit: Thanks Ray, its a passive old Jazz - the soldering was just done by The Bass Gallery (when they re-installed the original 30-odd year old pickups pickups) and looks very neat to me

Silly question but - before I take off control plate - where exactly do I spray the switch cleaner? Is there a hole in the pot casing or do I just spray the general area?

Edited by Clarky
Link to comment
Share on other sites

OK, tried cleaning the bridge pot with switch/contact cleaner ... and it made no difference :rolleyes: :lol::)

To be clearer on the crackling sound, its like an electrical crackling/hiss/interference type sound thats at a low, just audible level when not playing the bass but gets louder when I play the strings (its much louder on the low E). When I touch the bridge it gets louder too (which to my un-electrically-educated mind sounds like a shielding issue)

Any more thoughts anyone? Many thanks in advance

Edited by Clarky
Link to comment
Share on other sites

[quote name='steve-soar' post='795296' date='Apr 3 2010, 09:00 PM']Can you take pics of the wiring and sheilding within the control cavity and pickup cavities?[/quote]
Here's one I took for eBay listing. The wiring and soldering all looks very neat to me. The cavity is, like all old Fenders, unshielded bare wood

[attachment=46363:Clarky_J...bass_007.JPG]

Edit: and a better one of the soldering

[attachment=46364:Clarky_J...bass_008.JPG]

Edited by Clarky
Link to comment
Share on other sites

Perhaps it was always noisy (how long since you had the original pickups in there?)

Probably worth just disconnecting the pickup and hooking it directly to a jack cable (just hack off one jack plug and twist/solder the leads directly to the pickup wires - if that's ok, then it's volume pot or bad joints (soldered that is :) )

Otherwise take a good look at the offending pickup for signs of cracked/chipped magnet and/or damaged coils. Look for any iron or steel garbage floating around...

Link to comment
Share on other sites

[quote name='Stewart' post='795393' date='Apr 3 2010, 11:21 PM']Perhaps it was always noisy (how long since you had the original pickups in there?)

Probably worth just disconnecting the pickup and hooking it directly to a jack cable (just hack off one jack plug and twist/solder the leads directly to the pickup wires - if that's ok, then it's volume pot or bad joints (soldered that is :rolleyes: )

Otherwise take a good look at the offending pickup for signs of cracked/chipped magnet and/or damaged coils. Look for any iron or steel garbage floating around...[/quote]
Thanks Stewart. I really don't know about the original pickups. When I bought the bass it had EMGs on and I had the Gallery install the originals (after I had tracked them down and bought them off the original owner, who had them on a fretless 'bitsa' bass). I asked the Gallery to check out the pickups after installing them and assumed all was well when I put it for sale. Hence I am a bit miffed to discover this issue on plugging it into an amp.

TBH, I don't have the confidence to dismantle the bass further so I have explained the issue on the eBay auction and cut the price by £75 (which should cover a luthier's costs of shielding, whch seems to me to be the likely problem here). Like I say, this should have been checked properly :)

Link to comment
Share on other sites

[quote name='velvetkevorkian' post='795865' date='Apr 4 2010, 06:07 PM']Can you not take it up with the Gallery?[/quote]
I could but it means schlepping over there (a couple of hours there and back on London transport) and arguing the toss. I will cut my loss at £75 ... assuming that the bass sells at all. If it doesn't sell, I will be heading over there.

Link to comment
Share on other sites

OK, the potential buyer of this bass asked me to photograph the underside of the pickups which I duly did. Screwed them back in and - hey presto - crackle from bridge pickup has disappeared :)

I can only assume one of the wires was somehow touching something metal (maybe the metal plate below the pickup) and in taking it out and reinstalling I have inadvertently (but successfully) fixed the problem. Good news as it proves there was never a serious issue and as it means no schlep over the Bass Gallery.

Maybe its the bass equivalent of kicking the TV to sort out the picture!

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...