Why My J Bass hums?

[Cachaito]

When my pickup knobs are not at exactly the same setting, say both full on or both at half on etc. I get a noticeable hum or buzzing. It is tolerable when just on a small practice amp but plugged into the PA it is atrocious! It has done this always since new. Now I want to explore different tones, thanks to you guys. But I can't without this awkward noise. I can't even go full on with on pickup and full off on the other. I wonder is this common. Or have I got a lemon? Any advice would be greatly appreciated. Thanks in advance! Its a MIM Jazz Bass.

 

[mfbolton]

This is due to the inherit hum in a single coil pickup. Jazz Bass pickups are wound to cancel each other out when the signal levels are matched. So when you have them set to different levels you will get some 60 cycle hum. There are ways you can reduce that, like adding shielding to the body cavities.

 

[jd56hawk]

You can always upgrade the pickups, too...Fender Super 55s or Lace Sensor Man O' War Jazz pickups, both noiseless, both quite potent.

 

[bassbenj]

This is due to the inherit hum in a single coil pickup. Jazz Bass pickups are wound to cancel each other out when the signal levels are matched. So when you have them set to different levels you will get some 60 cycle hum. There are ways you can reduce that, like adding shielding to the body cavities.

Note that adding shielding to cavities will NOT reduce single coil hum! If you have some hum of the kind that gets less when you touch the strings or ground, shielding will remove THAT hum which in turn will make the single coil hum less noticeable. But the single coil hum can ONLY be removed by either having both pickups at the same level (turns the pair into a big humbucker) or by changing to hum-cancelling J pickups. The problem is that hum cancelling J pickups typically do not sound as good as single coils. So it's a trade-off.

I have SCN pickups on my J bass and a DiMarzio ultrajazz on my PJ and they sound pretty good for hum cancellers in my opinion. But real single coil tone takes a real single coil pickup and that means single coil hum. About the best you can do with that is try to move away from the hum source. I find my Amp head is a REALLY good source of single coil hum. Lighting gear makes great hum too!

 

[megafiddle]

With single coil hum, there will be some orientation of the bass where the hum is virtually gone. If it is not practical to turn the bass (and yourself) sideways enough to find this "null" position, you may be able to identify and reorient the offending equipment. These are typically anything containing a power transformer, like amps. Have someone rotate anything that might be suspect while the hum is present. You will know immediately if that is the source of the hum.

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[Cachaito]

That is all excellent feed back guys. Thank you very very much. I guess I got my answer! Awesome. I am thinking of getting a P Bass, it won't have this issue I assume! So thanks to mfbolton,jd56hawk,bassbenj, and megafiddle for replying. You all rock! I will implement the advice and work with the single coils. Perhaps implementing a mild soundgate or volume pedal will help too. I am just glad to know that there isn't something bad wrong with Hanna (thats my Basses name).

 

[Chrisk-K]

With single coil hum, there will be some orientation of the bass where the hum is virtually gone. If it is not practical to turn the bass (and yourself) sideways enough to find this "null" position, you may be able to identify and reorient the offending equipment. These are typically anything containing a power transformer, like amps. Have someone rotate anything that might be suspect while the hum is present. You will know immediately if that is the source of the hum.

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The hum will not go away regardless of orientation. A certain orientation makes noise caused by EMF go away because EMF is typically directional.

 

[megafiddle]

The hum will not go away regardless of orientation. A certain orientation makes noise caused by EMF go away because EMF is typically directional.

That's true for hum caused by a bad ground, or capacitively coupled AC buzz.

If it's single coil hum, there is absolutely a null position.

Try it. Place a single coil instrument near an amp power transformer so as to pick up noticable 60 Hz hum. Rotate it through all 3 dimensions and there will be a null somewhere.

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[Doner Designs]

As others have said, you can get humbucking J bass pickups. The inline splits will sound most like single coils. They are like a P bass pickup under a J bass cover. DiMarzio Area J's are like this and are reasonably priced. Nordstrand and others make them but you will pay a little more. BUT, there is a new solution in town. Check out the Audere JNC noise cancelling preamps. They use a phantom coil in the control cavity to cancel out the hum regardless of pickup mixing plus you get multiband tone controls and you can keep your Fender pickups and pure single coil tone. I was a skeptic but installed one in this bass recently and have been very very impressed. It works exactly as advertised - single coil tone with no hum whatsoever. Mine is a more complicated custom because of the four pickups, but Audere sells drop in control plates that will fit most J basses.

 

[Wallace320]

That's bass porn to me...

Probably one of the best lookin' basses around

Congrats Steve!

Cheers,
Wallace

 

[Muddslide]

It's not humming; it's crying inside because it wants to be a P bass.

J/K!

 

[Doner Designs]

It's not humming; it's crying inside because it wants to be a P bass.

J/K!

Ye speaketh blasphemy.

 

[Muddslide]

Ye speaketh blasphemy.

Ha! Yeah, I couldn't have been LESS serious when I said that. I just find the whole "P vs. J" or "MIA vs. MIM" or "Fender vs. Any Other Brand" threads/discussions amusing.

I really have no dog in that fight.

Over the years I've come to be a pretty solid P guy, but I love a good Jazz and I am glad there are so many different options for players these days.

 

[DiabolusInMusic]

@Doner Designs those things are great (do you work for the company??) but they do not work passively. You will still have to give up something to maintain single coil tone. In today's day and age you can get a pretty good single coil tone out of some humbuckers. It depends what the OP's end goals are. I prefer passive basses so I do not have much interest in the Audere.

 

[Scottkarch]

I picked up a Hum Debugger pedal EHX.com | Hum Debugger - Hum Eliminator | Electro-Harmonix
I think it works fantastic and I can't hear anything removed from the signal. It is not just a 60 hz filter. It has an AC/AC adapter so it's feeding the pedal AC power I'm assuming so it knows when the 60hz wave is peaking and reduces 60hz most when the ac sine wave is peaked. So I assume it's some kind of active filter that follows the AC power you're on. I find it works great with my Jazz and Ric.

 

[AltGrendel]

I was going to post a smart remark until I saw Steve's post.

Took my breath away, that looks so cool.

 

[Doner Designs]

@Doner Designs those things are great (do you work for the company??) but they do not work passively. You will still have to give up something to maintain single coil tone. In today's day and age you can get a pretty good single coil tone out of some humbuckers. It depends what the OP's end goals are. I prefer passive basses so I do not have much interest in the Audere.

No, I don't work for Audere but realize I probably sound a bit like a promoter. Just a happy customer and have gotten to know David Meadows a bit via email with custom orders like this one and a Siamese twin model he did for my magnetic/piezo Spectorcore (separate pre for each pickup with VV, TT, MM, BB conjoined stacked pots).

I don't know if he ever plans to offer a production model without tone controls, but think he might. He's making a custom rig for a telecaster guitar we are building and it will not have any tone controls, just the noise cancellation coil and circuit.

I tend to be a skeptic, so I had an active/passive switch included with the Pro-Z model that I have on my P bass. The Audere preamps do not add any gain or color the sound if the tone controls are set flat. The active/passive switch is unnecessary except as a demo type thing and to provide the option to skeptics.

Even without the tone controls, the noise cancellation circuitry would need a battery and that might be a downside for some.

 

[bassbenj]

@Doner Designs those things are great (do you work for the company??) but they do not work passively. You will still have to give up something to maintain single coil tone. In today's day and age you can get a pretty good single coil tone out of some humbuckers. It depends what the OP's end goals are. I prefer passive basses so I do not have much interest in the Audere.

You are right, but phantom coils CAN be made to work passively. You wire the phantom coil in series with the pickups so it cancels hum. I've done this with J bass single coils and the hum is gone! That's the good news. The bad news is that phantom coil inductance is added to the pickup inductance and it significantly changes the tone. Finally, I gave up on the idea. This is why Phantom coil setups (Alembic, Audere, etc.) are active. It solves the signal mixing problem.

 

[jd56hawk]

I've tried the Audere JZ3 with Fender Super 55s...excellent combo, in fact, after talking with someone at Audere, I've found out that they recommend the Super 55s.
This time I'm going with Lace Sensor Man O’ War Jazz pickups...the output of these pickups equals many active systems on the market today, and Madison's Deluxe Passive Jazz bass control plate.
I'm going to have the most potent Squier CV Jazz bass around!

 

[bholder]

I picked up a Hum Debugger pedal EHX.com | Hum Debugger - Hum Eliminator | Electro-Harmonix
I think it works fantastic and I can't hear anything removed from the signal. It is not just a 60 hz filter. It has an AC/AC adapter so it's feeding the pedal AC power I'm assuming so it knows when the 60hz wave is peaking and reduces 60hz most when the ac sine wave is peaked. So I assume it's some kind of active filter that follows the AC power you're on. I find it works great with my Jazz and Ric.

Neat, I was actually looking for something like that - my practice amp is on a very noisy circuit - didn't occur to me to check whether EHX had a gadget.