Hum with EMG P active pickup

Gear
1

While playing around with VST effects, I noticed that for some effects an annoying ground hum is amplified.
I haven’t noticed this while playing clean, but it is definitely a hardware issue as the hum disappears when I touch the metal volume knob or the output jack.

I am pretty astouned as active EMG pickups should be humfree and grounding is not required.
I checked all cable connections and they are firm and correct.

Now, my idea is to connect the bridge ground cable somewhere to the EMG electronics, if possible by plugging in, not soldering…

But where???

EDIT I could just solder to the stereo output jack. I guess the correct location would be the sleeve/ground, right?
Still I ask myself how an active pickup can hum!?

image

2

Not true at all, the electronics need to be properly grounded regardless of pickup.

1 Like
3

I thought that the ground connection would be suffufficient for this EMG.
I did not find anything in the EMG wiring diagram that allows for proper grounding via the plug-in connectors.

So I just solder to ground (S) on the output jack !?

image
image1257×637 121 KB

4

That connection is grounded, but you also need to properly ground the bridge and strings to the same common ground via the bridge ground wire.

1 Like
5

Yeah, done all that!

Took the opportunity to use my dremel and made a little more space for the 9V battery, as it was a little cramped.
Enjoyed the soldering, so now I will solder anything that can be soldered. There are already some cables looking at me, seductively. They want it :slight_smile:

Finally, the hum is gone … and I’m looking for an excuse to put some cover shielding into the cavities too. Cause … why not?

And, funny: I did not like some of my VST effects, cause it was all noise, even when I did not do anything.
So this happend with extreme fuzz effects. Why?
Today I gave the fuzz effects a 2nd chance (your fault, @howard, as you said somewhere that you like them!).
It turns out that you could not notice the hum when playing clean, but it was noticeable and has all kinds of side effects on the fuzz effects.

Now the hum is eliminated, the Fuzz is usable for the first time. Thanks!

2 Likes
6

So it’s the battery housing?
Active EMG uses current to reverse polarity and cancel hum so it’s unlikely to generate hum as is. But pressure from the battery clip would explain the anomaly.

1 Like
7

Ah, that could be it too!

I soldered a cable from the bridge on the the S connector (mass), but as you’ve read, I also made some space for fitting the battery properly.

Your theory is good, as I don’t always had the hum issue. Every time I inserted the instument cable plug into the jack, it touched the battery and pushed it around in the narrow cavity with all the cables and everything.

So, potentially it put pressure on the battery clip!

Now, with the larger cavity there is more space, thus no pressure on the battery.

So, the bridge/jack (mass) connection makes no sense? It doesn’t hurt, right? So I leave it as is…

1 Like
8

@Al1885 & @howard - I noticed that the bass sounds better now too. MUCH fuller and clearer!

Could it be that the lack of ground and/or the loose battery connection had impact on the tone “quality” (like micro distortions or something like that) which could not be heard if you don’t know what it can sound like (except when using fuzz effects)?

EDIT an indication for “micro distortions” might be that I could not do a precise tuning with bx_tuner VST before. There were quite some fluctuations of measured frequency before I solved the humming issue.
Now I can tune very precisely…

1 Like
9

I think it is more likely one of the ground connections was loose or had poor contact

3 Likes
10

Not trying to be argumentative, but this is straight from EMG’s installation instructions (for active pickups).

“All EMG Pickups are compatible with each other. EMG accessories, the VLPF, EXG, SPC or RPC Controls can be added to any EMG Pickup System
without requiring an extra battery. DO NOT reconnect the bridge ground wire, EMG Pickups do not require string grounding.”

4 Likes
11

Whoa! Wild. So the strings just have a floating ground then? I would be surprised if that didn’t generate noise, and the fact that it goes away when the strings are touched kind of substantiates that.

Thanks for passing that on! That’s super interesting.

3 Likes
12

Actually you are very helpful, so thank you!

Would there be a risk to keep it connected to ground?
The hum is gone, the tonal quality is improved.
I wouldn’t wanna go back to the humming.

Also, I’m going to shield the cavities. That must be grounded too, right?

PS I could not read the d@mn fine print in the manual, but I knew from reviews that “grounding is not required” - see above!
The manual (“DO NOT RECONNECT THE BRIDGE GROUND WIRE”) makes it sound dangerous…

1 Like
13

You’re welcome!

I do not believe that leaving it connected would be harmful. I’d leave it be.

1 Like