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Need help with hum (Lakland Glaub)

moro

moro

Geek
Sep 5, 2006
504
4
Bay Area, CA
#1
I just bought a used Lakland Bob Glaub and it hums. The hum goes away when I touch the strings / controls / bridge so I figured it was a grounding issue. I opened it up and all the wiring seemed fine, but just to make sure, I shielded the control cavity, replaced the pots and jack (which were a bit rusty), and re-wired it, but the hum is still there.

:(

I'm really not sure what to do. Does this wiring look ok?

126007102-M.jpg


The previous owner says that he didn't experience any hum. Is it possible that something happened to the pickup during shipping?

Thanks.
 
#2
As of my experience, the hum IS a grounding issue, but on your amp... Or you have a really bad cable...

So, just try putting your amp in an other room or try your bass in another amp. If it doesn't humm anymore, it can't be the bass.
 
#4
I am having the same problem with my Kelly fretless. Finally realized after taking it to the shop that it only hums on the second floor. It did not hum in the shop or downstairs. Have tried it with 2 amps, changed all the cables and it still hums only on the second floor and not with any of my other basses. Having a master electrician come in next week and check all of the grounding in the house. The house has 2 circuit boxes and has had 2 additions.

For know I take it downstairs to use it :hmm: :crying: :bawl:
 
#5
Gintaras said:
I am having the same problem with my Kelly fretless. Finally realized after taking it to the shop that it only hums on the second floor. It did not hum in the shop or downstairs. Have tried it with 2 amps, changed all the cables and it still hums only on the second floor and not with any of my other basses. Having a master electrician come in next week and check all of the grounding in the house. The house has 2 circuit boxes and has had 2 additions.

For know I take it downstairs to use it :hmm: :crying: :bawl:
Click to expand...

You've got to be kidding. :( I'm not sure how I would isolate a problem like that. I live in an apartment and I'm sure all the electricity is on the same circuit.

How would something like this even happen?
 
#6
moro said:
You've got to be kidding. :( I'm not sure how I would isolate a problem like that. I live in an apartment and I'm sure all the electricity is on the same circuit.

How would something like this even happen?
Click to expand...

It has everyone baffled :hmm: one of the guitarist that I play with is a master electrician and he is going to come over this week. What has us perplexed is that the second floor is not dedicated to one of the circuits. Part of the upstairs is the original house and on the original circuit box. I still think that part of the problem is the Kelly since none of my other basses do this.....

Have you played your rig anyplace else??
 
#7
Could it be you have ground loops? Just judging by the diagram you sent, there are multiple paths to ground. Try doing a "star" grounding of the different component grounds. The Guitarnuts website has a good write-up on shielding and doing star grounding. Did this on my jazz bass and the amount of hum reduced significantly. It's still there, but not as substantial as before. Whatever hum's left I attribute to the amp and things outside of the bass since I get different levels of hum when using a crappy practice amp, a better quality amp, and the headphone out of different multiplyFX boxes - all of these using headphones.
 
#10
moro said:
You're right. All the pots are connected through the shielded pickguard, so I got rid of all the unnecessary wires.

Now it's more of a buzz which goes away when I roll the tone completely off. Argh.
Click to expand...

What you have is the same case I have now. Crank up the treb and the buzz can be feintly heard through headphones on a headphone amp. Using an amp and I can hardly make out the buzz. Aside from bad grounds, interference etc. from the environment (not the bass), whatever buzz at extreme settings might be due to the single coils. I'm not familiar with Laklands but do you have single coils or humbies?
 
#12
I have a US Glaub that hums exactly as you describe through every amp in every room. The only other bass that hums for me is my Skyline Hollowbody with Dark Stars. I have not made any attempt to quiet them down yet because it has not been critical to do so yet, but it has really surprised me to have so much hum from my Glaub.
 
#13
One thing is hum and another thing is a grounding noise/buzz. I have a USA Glaub as well and I get a grounding buzz when I lift my hands of the strings/bridge, but it is no hum (which is a low, rumbling sound).

The buzzing is normal in most passive basses. If you have "hum," though, I wound think that the pickup is not wired conrrectly and is not humbucking. . .

As mentioned before, some electrical instalation may amplify noise ot extreme levels, like when you have certain light type plugged in the same system, etc.

I have experienced bad hums with even the quittest basses when there a light (concert lights) plugged in the same circuit as my amp.
 
#14
lefty007 said:
One thing is hum and another thing is a grounding noise/buzz. I have a USA Glaub as well and I get a grounding buzz when I lift my hands of the strings/bridge, but it is no hum (which is a low, rumbling sound).

The buzzing is normal in most passive basses. If you have "hum," though, I wound think that the pickup is not wired conrrectly and is not humbucking. . .

As mentioned before, some electrical instalation may amplify noise ot extreme levels, like when you have certain light type plugged in the same system, etc.

I have experienced bad hums with even the quittest basses when there a light (concert lights) plugged in the same circuit as my amp.
Click to expand...

Thanks. Having not experienced it in my first decade of playing bass (all active instruments) I was surprised by the buzzing and figured that was the same as humming. I have buzz and it is negligible.
 
#15
I *think* my current problem is a buzz, not hum. The active vs passive issue is interesting--this is my only passive bass. Though I don't have any problems with my passive guitars.

The buzz isn't the sort of background noise I sometimes hear on my other basses, though. It's a very loud buzz that makes it nearly impossible to play with the tone knob at full.
 
#16
Based on lefty007's suggestion, I tried turning out the lights in the room. That changed the quality of the buzz but not the quantity. That was promising, though, so I tried shutting down my computer. Nothing. So then I started uplugging things from the walls. When I unplugged the iPod power supply, the buzz went down considerably.

Weird, huh? I totally don't understand electronics.

So after that, the bass was much quieter, but there was still a fair amount of buzzing. Based on a hunch, I decided to shield the pickguard and to ground the pickup cover for good measure:

126423698-M-1.jpg


It isn't pretty, but it worked. The bass is dead silent now, even with the iPod power supply plugged in. Hooray!

Thanks everyone, for your advice.
 

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