Jazz Bass Hum Elimination?

[SGD Lutherie]

Again, copper foil will eliminate higher harmonic electrical field noise (buzz), but it cannot eliminate 60 Hz hum. This is because copper cannot block magnetic fields. You would need a mu-metal magnetic shield for that, or at the very least steel shields such as you find on Lace sensors.

If shielding eliminated hum from single coil pickups, then the humbucker would never have been invented. But you are correct that most Fenders are inadequately shielded. proper shielding can make the bass a lot quieter.

A properly shielded humbucker (and most of them have no shielding) is very quiet and for the most part you can even do away with control cavity shielding, and string grounding. EMGs are an example of this. And it has very little to do with them being active, since they are basically regular high impedance pickups with built in preamps.

[MusicBear]

True, mu-metal would reduce electromagnetic interference, but if it was improperly placed it would also interfere with normal pickup behavior. (Lace probably places it around the back and sides of their pickups.) Copper eliminates the noise most players are bothered by.

There is the whole matter of signal-to-noise ratio in any system. From a practical standpoint when a player sits with a copper-foil shielded bass in his lap and cannot hear any hum or buzz from it over any background noise - the hum of lights, the rushing of his amp, the sigh of the HVAC system, et cetera, then the bass is "quiet." No buzz when you lift your fingers off the strings...

[line6man]

Originally Posted by allexcosta

Shielding solves 90% of the problem. I like conductive paint myself, not that it's better, but I can use some cotton swabs to put them inside every cavity in the bass including the wire channels creating a true Faraday cage and that makes the single-coil hum minimal...

It is impossible to create a true Faraday cage on a bass unless you are completely shielding the pickups. If there are ANY gaps in the enclosure, it is not a true Faraday cage.

Applying conductive paint to the wire channels does nothing. The wire exits into pickup cavities that cannot be completely shielded unless you stuck copper tape over the tops of the pickups to completely enclose them. A slightly better solution is to use shielded wire, though that requires modifying some pickups.


ElectricBlue, if we're talking about 60Hz hum, that is not one exact frequency, it is usually a fundamental (60Hz) and several harmonics above it. If you want to try to EQ out 60Hz hum, the best way to do it is with four or five bands of very narrow bandwidth EQ set on the fundamental and the first few harmonics. This method still yields questionable results.

[AltGrendel]

Originally Posted by SGD Lutherie

Having said all that, I think my Sidewinder Jazz pickups sound very much like real single coils, and even quite a bit like a Jazz bass. They get a nice burp at the bridge and the neck is deep and buttery.

Yea, but they're out of stock.

[SGD Lutherie]

Originally Posted by AltGrendel

Yea, but they're out of stock.

That's due to a shortage of pickup covers.

You have a PM.

[sunbeast]

Originally Posted by line6man

ElectricBlue, if we're talking about 60Hz hum, that is not one exact frequency, it is usually a fundamental (60Hz) and several harmonics above it. If you want to try to EQ out 60Hz hum, the best way to do it is with four or five bands of very narrow bandwidth EQ set on the fundamental and the first few harmonics. This method still yields questionable results.

This is the premise of the Electro-Harmonix Hum-Debugger. It works really well until you hit notes with important content in the eliminated frequencies- specifically the low B sounds dead as the fundamental of that note is greatly reduced. It works great for guitars though in my experience!

[shoot-r]

Originally Posted by shoot-r

I LOVE the sound of the stock pick-ups that came in my Fender Road-Worn Jazz bass.
But, they have a more than normal amount of passive jazz bass hum.
Atleast more hum than any passive Fender jazz I've owned in the past.
Is there a way to ground/eliminate this hum without changing out the pick-ups?

Thanks to all...

Just wanted to say thanks to SGD, MusicBear and all the others for their recommendations on this post.
I finally found a gentleman in southern Illinois that did a complete shielding job/ground check and set-up on my beat up Fender jazz bass.
The difference is nothing short of absolutely amazing!!!
This was easily the noisest jazz bass I've owned/played in 40 plus years of trying to play.
It's now the quietest!
Thanks all!!!

[cflat]

I've mentioned before, the single coil is awesome but you can't get rid of the noise...My new Area J's are humbuckers, dead quiet and awesome sounding. I also use DM J's but they aren't as single coily as the Areas..As I mentioned in another post the neck pu is one of the few that I've ever liked just by itself. I usually have the bridge full on.

[SGD Lutherie]

Originally Posted by cflat

I've mentioned before, the single coil is awesome but you can't get rid of the noise...My new Area J's are humbuckers, dead quiet and awesome sounding. I also use DM J's but they aren't as single coily as the Areas..As I mentioned in another post the neck pu is one of the few that I've ever liked just by itself. I usually have the bridge full on.

You can have humbuckers that sound exactly like single coils. I know because I make some, and others do as well.

The problem is people get hung up on one particular single coil sound, and think that's the only sound a single coil makes.

I'm with you though, I refuse to use pickups that hum.

[cflat]

Yes, no sense these days to have hum and racket with all the great pickups these days, and all the cool gear we have..

[swpyne]

Originally Posted by ShoeManiac

LOL! The timing of your post is really funny. At least to me!

I had some hum with my roadworn Jazz bass. I love the bass, but I had some very considerable reservations about recording with it since there was some hum present. Some recording sessions got scheduled for my band and I knew I had to do something if I wanted to record with this bass.

So I decided to do TWO things: first, I was going to get a pair of Lollar jazz bass pickups. I had a chance to try some Lollars in a Nash JB-63, and they sounded awesome! More of that Jazz bass growl, and a great all-around tone. Next, get the control cavity shielded. So I ordered the pickups and scheduled some time with my luthier to get the pickups installed and a shielding job. I opted for the shielding paint, since it's a more long lasting solution. They also did the pickup installation. The result? The bass sounded great in the studio today. And no hum!

I also have a pair of Lollar pickups in a 2008 US Fender jazz bass and they are virtually silent. Plus they sound huge with great vintage tone. This is the solution IMO!

[Metania]

I wish! My JB is definitely properly shielded, but the neck pup will not stop giving a crackling noise when I touch the strings or let go of them. Touching the hardware stops the noise completely. Everything's grounded and all wirings are good. The neck pup is freshly rewound! But the crackling will not stop!!! Some days I don't care, while others I flip out and wanna sell the bass!

[El-Bob]

Originally Posted by Metania

I wish! My JB is definitely properly shielded, but the neck pup will not stop giving a crackling noise when I touch the strings or let go of them. Touching the hardware stops the noise completely. Everything's grounded and all wirings are good. The neck pup is freshly rewound! But the crackling will not stop!!! Some days I don't care, while others I flip out and wanna sell the bass!

Um... no. I hate to break it to you, but something is absolutely wrong with your bass (my guess is the grounding).

[NYCbassist]

Originally Posted by MusicBear

Proper shielding will eliminate the hum you hear from your Jazz Bass. Older Fender basses had no shielding and newer basses make only a token effort with conductive paint - but, as you point out it doesn't kill the noise.

Copper foil, properly installed, will eliminate all but the very slightest amount of hum from the original single-coil pickups. Then all you have to do is move/turn a little bit and the bass will be silent when you are not playing, and you will hear nothing while you are playing.

I've done this to dozens of Jazz Basses, Rics and other single-coil pickup basses. My customers are always amazed that the bass ends up QUIET.

(There will be some noise from even the best hum-cancelled pickups if they are installed in an instrument that is not properly shielded.)

Right on! Sadowsky Single coils used to have(May still) Copper shield under the insulation. Quiet as a whisper. It don't matter in a live jam situation but I could see worrying about it in recording. Although I don't record in a way that any hum could get through anyway.

[bassbenj]

Originally Posted by NYCbassist

Right on! Sadowsky Single coils used to have(May still) Copper shield under the insulation. Quiet as a whisper. It don't matter in a live jam situation but I could see worrying about it in recording. Although I don't record in a way that any hum could get through anyway.

What does "record in a way that any hum could get through" mean? Is that like recording with your volume control turned all the way down?

Look guys. Musicbear is only partly right. Otherwise he's spinning a false yarn. Truth is there are TWO kinds of hum: Electrostatic and magnetic. Copper shielding ONLY kills electrostatic hum (the kind that goes away when you touch the strings). It DOES NOT (repeat) DOES NOT kill single coil hum. Only MAGNETIC shielding will do that and the closest thing to that is that big metal "bridge" over the top of a Ric pickup and that doesn't work very well. Fender pickup covers, while steel, are too thin to be effective magnetic shields.

But Musicbear is correct that IF You use copper to get rid of all the electrostatic hum, the single coil hum that remains will sound quieter and be much less objectionable. Well that is unless you are standing by a strong magnetic source. Lighting systems, voltage regulating transformers and especially power transformers in powerful amps qualify. My Laney amp is really great at making single coil hum when you stand next to it.

So as others have already pointed out, the amount of single coil hum you get depends on what is running in the room with you, how close you are to it AND what the orientation of your bass is with respect to that source. Usually single coil hum CAN be "nulled" out by rotating your bass around to some position (which you may or may not be able to play it in).

Generally, single coil hum can ONLY be removed with a humbucking arrangement and while I won't say that it's "impossible" to get a humbucker to sound like a single coil, I haven't seen it yet. David is trying to imply that certain humbuckers can sound just like single coils. I've heard some that sound VERY good. I love the SCNs in my Fender Jazz. I love the Dimarzio in my PJ. Great tone, but I wouldn't say "just like" a single coil. I love Nordies, but they are kind of $$$ so I don't have any yet. But I still wouldn't call them an exact single coil tone. I'd love to try David's sidewinders if he gets them in 5 string sizes.

So until word spreads on TB that XYZ pickup model ABC sounds JUST LIKE a single coil, I'll have to remain skeptical. And while copper shielding will reduce your hum to a minimum, it WILL NOT remove single coil hum. Period.

But then when you have a jazz bass with both pickups on and equal volume settings that IS a humbucker arrangement with no single coil hum. So that is a good way to test to see how much OTHER hum the bass has. It's only when jazz pickups are soloed that single coil hum is a problem.