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EMG J-Set Hum

H

hfader

Nov 8, 2007
10
0
#1
Hello all. Long time listener, first time caller.

I just installed an EMG J-Set on my Fender Japanese 70's style Jazz. I was tired of having to keep the volume controls equal to cancel out hum. I've been disappointed that there is still a considerable amount of hum with pickups and tone pot turned up. I've been over my installation job with the EMG tech and he could find nothing wrong. I've been over this with a fine tooth comb. The cavities are shielded with copper foil so it ain't that. Not trying to impress anybody with my credentials but I'm an electrical engineer and also trained as an electronics tech. So I pretty much know my way around this sort of thing.

It's not unbearable hum but I expected dead silence. I asked the EMG tech to check a few basses and he said they were quiet for all pot positions. I also went and plugged in another stock Jazz into the same amp. It's quieter than the EMGs when volume controls are turned all the way up! Maybe it's the definition of quiet. I'd say quiet would be the same amount of hum from the amp as with the guitar totally unplugged. I'm wondering if my expectations are too high. I don't want to return these for another set just to find the same issue.

So what are other's experience with these pickups? Are they dead silent or quieterER?

- Hugh
 
#4
hfader said:
So what are other's experience with these pickups? Are they dead silent or quieterER?

- Hugh
Click to expand...

I have 2 Fenders with EMJ J in them, the basses are identical, one is dead quiet and the other hums like crazy, more so than my passive basses. I suspect an internal problem with the onboard amp in the humming one, and it does not seem to be a grounding problem since the hum is equal with or without a grounding wire. I guess the ultimate test would be to swap the pickups and see what happens
 
#5
I'm under the impression that the EMG-J's ARE susceptable to hum. I know the original Sadowsky 24F (Modern) came with EMG40J's which are J pickups in a soapbar cover. I'm assuming that they are the same J's just different cover, although I could be wrong. They stopped using them because of the noise issue according to Roger.
 
#6
hfader said:
I just installed an EMG J-Set on my Fender Japanese 70's style Jazz. I was tired of having to keep the volume controls equal to cancel out hum. I've been disappointed that there is still a considerable amount of hum with pickups and tone pot turned up.
Click to expand...

EMG J's are stacked humbuckers. They don't need to have both pickups on to cancel hum.

I had a set in my Ibanez 5 string and they were dead quiet. I had the 40P5 and 40J in a few of my basses and they were also very quiet. No hum at all.

Are you sure you have the bass wired up correctly? Another thing is the rest of the wring in the bass. If you left the original pots and non shielded wire to the output jack, that might be causing noise.

The pickups shouldn't hum at all. It's possible there is an issue with the pickups, like one coil is not working.

Regarding the J soapbars. The older ones have a regular J inside, on an angle. The newer ones have half a DC sized coil that's stacked.
 
#8
Thanks for the info everybody. Yes I'm absolutely sure I have these wired as specified. I'm using the controls that come in the pickup kit.

For the folks that say they get no hum -- I just want to make sure you're doing the same test as me. Do you turn the volumes all the way up and the tone pot fully treble?

Thanks again,
 
#9
I ran into this with a set of EMG's I installed and eventually found that where the wires are soldered to the back of the pot there was a bad connection. I removed the solder joint, roughed up the back of the pot with some sandpaper and resoldered the connection, using some flux to make sure it flowed well. No more hum after that. As you are an electrical engineer I assume you have gone over this but sometimes things look right but ain't! Hope it helps!!
 
#11
hfader said:
For the folks that say they get no hum -- I just want to make sure you're doing the same test as me. Do you turn the volumes all the way up and the tone pot fully treble?
Click to expand...

Mine all ran into a preamp with active bass and treble. No hum or buzz with the treble cranked all the way up.

Take a listen: [Invalid or Expired Link Removed]

And that's sitting in front of the computer monitor.
 
#12
Hey DAVIDRAVENMOOD you are wrong about the EMG J's being stacked humbucker. They are single coil but are internally grounded! Go to the website. I've had the P/J and the J sets and they are dead quiet. I put both on( different basses) because I couldn't stand the impedence loading that's inherant with passsive pickups. When you roll off the tone pot on passive pups the volume drops alot. The EMG's don't do that. Another thing that I notice about most J's is that they are not balanced string to string. That's one thing I hate about alot of J pups. That the A and D strings have less output than the E and G strings. The EMG J pups are balanced. I think EMG P and J pups are great pups. My only complaint is that they are very bright, but that's what the tone pot is for.
 
#13
eff-clef said:
Hey DAVIDRAVENMOOD you are wrong about the EMG J's being stacked humbucker. They are single coil but are internally grounded! Go to the website.
Click to expand...

Did you ever open one up to see? I bet you haven't.

What they are saying is they SOUND like single coils. You can ground a single coil all you like, and it's going to hum.

What they said is they are shielded, not grounded. EMG's have a brass screen shield that encloses the entire pickup. That screen acts as a Faraday Cage, and is grounded. The two stacked coils feed the input of a differential op amp which sums their outputs and cancels out the hum.

They DO NOT say they are single coils, this is what they say:

Instead of the side by side Pole pieces the EMG-J uses a single-pole crescent shaped magnetic field to complement the radiused fingerboard.
Click to expand...

They have a single blade facing the strings.

Their Strat pickups are also called "single coils" but they are stacked humbuckers.

Here's what they say about the SA:

One single Alnico bar magnet delivers classic overdrive with a smooth midrange distortion, while still retaining the familiar high-end of a single-coil pickup.
Click to expand...

And here's what's on the inside. A stacked humbucker. Any questions? :D (EMG's also don't have low impedance coils, see all that wire? ... just low impedance outputs)
 
#14
DAMM DavidRavenMoon, you've really looked into this!

A differential amp shielded as you describe is exactly the type of design you'd see in sensitive measuring equipment. It should be quieter than what I'm hearing.

I suppose another thing I could check is the cable from the pickups to the controls. A short or open connection on the shield wire could be a problem.
 
#15
hfader said:
DAMM DavidRavenMoon, you've really looked into this!
Click to expand...

I like taking things apart! That's how I started building guitars. The pickup in question was damaged, and I've always been curious about what's inside those things. I'm not interested in copying them, but as I said I like taking things apart. It's a very nicely made pickup, and the brass screening was a real surprise.

hfader said:
A differential amp shielded as you describe is exactly the type of design you'd see in sensitive measuring equipment. It should be quieter than what I'm hearing.

I suppose another thing I could check is the cable from the pickups to the controls. A short or open connection on the shield wire could be a problem.
Click to expand...

Something must be amiss. Either it's bad wiring, or the pickups are bad. But they really are very quiet pickups.
 
#16
I STAND CORRECTED. I believe that Bassplayer Mag. called them single coil in a pup shoot out ,and I think EMG leads most people to believe that they are. The radiused blade explains the even output(string to string)of the the J's. GOOD WORK DAVIDRAVENMOON !!
 
#17
Howdy - was this issue ever resolved? Just bought the same set and have EXACTLY THE SAME HUM ISSUE! :( Worse than the original single coils - hums in ALL pot positions (except off of course!)

I was thinking that the soldering/connection of the braided shield portion to that back of the pot is tricky - THAT provides the grounding needed and I'm wodnering if it needs to be super secure to work right?

At any rate, interested to know if the original poster ever got this reoslved....

Jamie
 
#19
Hey folks. I had numerous emails with the EMG technician. He could see nothing wrong with my wiring. He asked that I send the pickups in to check out. I didn't want to do that, so I exchanged them. I just installed the new pickups last night and same problem.

Here's what I notice. The problem is worse near my amp or standing in certain spots. This leads me to believe it's picking up electromagnetic interference from motors, transformers, etc. For those that aren't having the problem, I'll guess they are in a magnetically "quiet" area. Either that or there's something wrong with the shielding on the batch of pickups being produced. I did check continuity on the cables with an Ohmmeter and it was ok.

I'm not happy, but if I keep the tone low and the volumes less than 2/3 it seems ok. I don't really feel like sending the pickups in to them because that puts my guitar out of commission.

Attached is a picture of the installation.
 

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#20
Thanks for the pic hfader!

One thing I noticed - looks like ground wires from your shielding are connected to the neck volume pot casing. But the shielding also connects with the metal control plate due to the overlap up top - any chance you have introduced a ground loop which is being picked up and generating hum? I would try connecting the shield grounds directly to the output jack maybe.....or I could be offbase here - NOT and EE :)

My bigger cocnern is yo uare on the SECOND set and have the same issue - mine are a problem too, so if this is a design flaw I'll just take thgem back and get my money.....

Jamie
 

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