Hum when J pickups aren't at equal volume

Wissen

Wissen

Supporting Member
Nov 11, 2007
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#1
I'm sure this question has been asked 100x but I have had a hard time figuring out search terms to find an old thread that may have my answer.

I have a 2008 MIA Jazz with the S1 switch. When I do not have the S1 switch engaged, I get a hum if the volume pots are on, but unequal. If I have one pot at, say 7, I can find the "sweet spot" when I roll the other pot in and out of that 7 range. When they're both full on it's fine, and when one is on but not the other it is fine.

I know the practical outcome to this situation is "take it to someone who knows what they're doing and get it fixed." But I am a curious dude, and I posted to see if anyone has thoughts on what is happening, electrically speaking. The pickups are stock, obviously.
 
#8
The way in which a humbucker works is by having one coil reverse wound, reverse polarity from the other.
That way the noise induced from EMI in the room cancels out, because it's coming to the output twice in reversed polarity.

A Jazz bass operates like a widely spaced humbucker when both pickups are at the same volume.
 
#9
Wissen said:
Good to know. Apparently I have been oblivious for the last ten years, because I swear this was a new development. At the very least it has gotten louder recently.
Click to expand...

Just because single coils are susceptible to hum does not mean you will always get hum. Something probably changed in your environment that is causing additional noise. You can check the ground wire under the bridge, ensure it is making good contact, but it really sounds like everything is functioning properly. Have you gotten a new amp or anything that may just have made the noise more obvious?

The only real solution to 60hz noise is humbuckers. There will be a sacrifice in tone, however. I use Lindy Fralin humbuckers, I find them fairly close to vintage single coils. Alternatively, you can add an Audere system to function as a humbucker while retaining the tone but it is basically a 9v pre-amp.
 
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#10
Wissen said:
Good to know. Apparently I have been oblivious for the last ten years, because I swear this was a new development. At the very least it has gotten louder recently.
Click to expand...

It could be that something where you are playing is creating more interference than before. My Jazz bass with single coils is pretty quiet when I use it at home, regardless of pickup selection. Single coils are susceptible to hum, but it doesn't mean they will always hum.
 
#12
I bet it's the amp I'm plugging into, then. The only group where I have bass duties anymore, I share them with another guy and we aren't always picky about the amps we use. We have a couple Peavy keyboard amps that have some mileage.

I'm not a tone snob, so I doubt I'll be pursuing a pickup swap. But thanks for the info. Next time I get my bass setup I'll also have them look under the pickguard to see if everything is in order.
 
#13
Wissen said:
I bet it's the amp I'm plugging into, then. The only group where I have bass duties anymore, I share them with another guy and we aren't always picky about the amps we use. We have a couple Peavy keyboard amps that have some mileage.

I'm not a tone snob, so I doubt I'll be pursuing a pickup swap. But thanks for the info. Next time I get my bass setup I'll also have them look under the pickguard to see if everything is in order.
Click to expand...

My money says it is the lighting and the bass. If you want to test the amp, just turn it on with nothing plugged in. If the issue persists, it is the amp.
 
#15
Richard Carson said:
Is there any downside to switching out the factory pickups with the no-hum pickups? Why doesn't Fender just manufacture them with no-hum pickups if they are always a problem?
Click to expand...

Humbuckers do not have the same top-end as single coil pickups. You have to sacrifice some tone to get rid of the hum so 60hz hum is not necessarily a problem to everybody.
 
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#16
DiabolusInMusic said:
Humbuckers do not have the same top-end as single coil pickups. You have to sacrifice some tone to get rid of the hum so 60hz hum is not necessarily a problem to everybody.
Click to expand...

The sidewinding pickups on the Ripper are an interesting case and perhaps an exception to that notion. This was one of Bill Lawrence’s designs while he worked for Gibson. The pickup has a single set of magnets and two sidewinding coils, so the pickup is humbucking, but still has essentially a single coil sound due to having one set of magnets. The Ripper was my first electric bass, the only one for about 25 years and still my favorite due to the great sounds I get from it.

Unfortunately, it’s one one of Bill’s good ideas that hasn’t seen a lot of other use, just like the passive Q-filter midrange cut. I think Q-tuner is a brand that makes modern sidewinders and they even sell them in J pickup cases, which is a bit of a feat.

Looks like they have soap bar, MM and J cases.

Bass pickups - Q-tuner

I think there are some folks here who have tried them, but I haven’t yet, so I can’t offer a testimonial on these, only my favorable 35-year experience with the Ripper.

Otto
 
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