Question on humming/feedback

I have four basses - 3 active basses and one passive.

I run my basses through a Behringer U-Phoria UMC22 and can hear a slight humming/buzzing sound on all my active basses (the passive bass is clear as a bell). The buzzing goes away when I touch the strings or volume control on on the basses or if I bring the Behringer up close to the bass (like within 30cm of it).

I’m not sure it’s a grounding issue as it’s happening on all the active basses - having said this, I know zip about electronics and how they work. Can anyone offer suggestions on how to resolve this. I don’t think I really used to notice it. But since I upgraded the pick-up on my Squier Affinity PJ (passive) it’s so clear that it makes the humming so obvious on the others.


PS: RIP to the great man, Charlie Watts :cry:


@Bassdacious What are the basses and pickups on each?

Hey Eric,

I’ve got:

Sire V9 - stock pickups;
Ibanez SR600e - stock pickups;
Ray 4 with upgraded Aguilar MM pickup;

The Squier Affinity PJ (passive) was upgraded to EMG Geezer PJ.



Are any of them shielded?

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Is there an easy way to tell if they are without opening them up?


I don’t believe so. The coverplate on the V9 is 3 screws if it’s like my V7.

I had humming on my Paranormal, and copper tape put it to bed.


No, not if you want to be sure. Product websites aren’t always reliable. Specifically if you got it used. Like the Ray with the upgraded pickups. If you got it that way the person that did the upgrade may have gone ahead and shielded the cavity.

Take a look here to identify your hum.
Solving Guitar Noise, Buzz and Hum | Sweetwater

And here for an overview of these kinds of problems.
FAQ: Getting Rid of Guitar Hum, Buzz and Noise Issues - Guitar Gear Finder

There are a couple of weird things going on here and you will probably need advice from some of the more experienced electronics people like @terb, @howard, and some of the others I can’t think of off the top of my head.

The noise going away when you bring the DAI close makes no sense to me.

The other weird thing is I would expect the J pickup on the Affinity to buzz since there isn’t a second J pickup to balance it but that might be a feature of the Geezer EMG’s.

My best guess is you’re looking at a shielding issue. Not everybody uses copper tape for shielding. For instance, Fender uses a black conductive shielding paint.

Other things to check…

  • Were you using the same wall plug? A plug on the same circuit as a dimmer switch or a touch sensitive lamp can introduce interference.
  • Were you using all the same cables and pedals each time? A bad cable or a noisy pedal can make all the difference.

I’m looking forward to hearing if one of the noisy basses has shielding just because that would make things even more weird.


EMG has two coils in the J pickup. Like my Apollo J set, it’s a linear humbucker. So a feature


Damn. That’s cool.

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Cheers Eric. I changed out cables and still got the buzzing. My passive Squier has the black conductive shielding paint. I’ll have a look inside the others tomorrow - seems strange that it’s happening on all three. The socket I’m using is just for the laptop and and I run the DAI into that. Yep it’s weird - will post again tomorrow.

BTW - I am LOVING those Geezer PJ pickups.

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Does the noise go away when you point the bass in a different direction? Does the hum sound like it is 60Hz?

To me it sounds like grounding or shielding because it goes away when you touch the strings. No idea why it goes away getting close to the DAI.

My active basses pick up the EM noise leaking from my PC when I face towards it. This usually is much more noticable on active basses because the bass preamp amplifies it.


I didn’t know this. All of mine have been passive. Does shielding take care of this?

Yeah, and it’a also better on basses without unmatched single-coils, and worse on P/J in my experience.

J/J, the two pickups, if opposite-wound, can cancel the hum as if they were a single split coil. P’s are split coil. Humbuckers are obviously humbuckers. but with a P/J you just have that lone single coil J, and it picks up interference.


I think all EMG are humbuckers. even the old Stratocaster pickups (EMG S, SA …) are stacked dual coil with humbucking effect.


Can you record your hum in a DAW or only here ambient?

You can try a power conditioner ahead of everything.
What other electronics do you have plugged in close to your setup?
USB cables are crazy susceptible to noise, try swapping out. When I am connected into one of my pedals via USB to change settings I get crazy hum sometimes as well.

Is it very bad or only noticeable because you are in a room by yourself vs. with a band?
I always think some hum is going to be there and no one cares in a band setting but we here it in our setting of being home alone, could be totally wrong here.

Shielding helps but might not solve if that’s not where its coming from to begin with, but a cheap and simple just in case to do.


If a J/J coils are on different volumes, you can get hum though


yeah true

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Fwiw My Squier I’ve refitted with Emerson pots and ‘60s custom shop pickups has zero hum. I didn’t shield anything that wasn’t already (nothing was). It’s not an active bass but still zero hum.

The Rocco active PJ with Aguiler electronics had wicked hum when treble was up at all and more the more the J was used.

I have no hum in the active Frank Bello PJ system.

I have some slight hum in the Sims Glock setup but there is so much going on there I think something inside is touching something it shouldn’t. Have to investigate when it comes back from getting its pickguard made.


An easy way to split the system in half is to turn the bass volume knob(s) all the way down. If the noise goes down with the volume knobs, the problem is upstream of the knob. If the noise doesn’t go down with the knob, it’s not a single coil picking up noise for example.

You can play this same game with any volume knob in the system. If the knob makes the noise go up and down, the noise is before the knob in the signal chain.


Yeah, my system is - bass into DAI into laptop (via USB) and when I record it goes into Garageband. I notice it only as ambient noise. It is only slight but to me it’s something new - it may be because my Squier PJ is so damn quiet now. I’ll have a play with some of the suggestions you made re cables and balancing JJ pickups. I also think I won’t notice it when I record, as it is just slight. You’re right about sitting in my lounge room and it magnifying the noise. I’m sure in a band setting it would not be at all noticeable. I’ll have a play around today with it. Cheers

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