Strange "body" hum

[Franx]

I have some kind of weird humming problem:

I've swapped the bridge-PU of my Soloist for a J-90C; great sound - so far so good.
But when I turn the volume to 10, I hear a pretty loud low frequency hum. Grounding issue, I thought ! Re-wired everything - no change.
So I soldered the pickup directly to the guitar's output jack - some additional noise (because of the missing grounding) and still that strange hum.

Maybe the back of the pickup is touching the body ? I put some extra hard rubber to the pickup's backside - still there !?!

So what could it be ? It goes away sometimes by moving around (changing the angle to the cab) and of course by turning down the volume.

Next thing I'll try is extra-shielding the pu-cavity with some copper-tape ! If this doesn't help, too - I will go for EMGs.

Any ideas ?

Edit: I already installed other pickups - to be sure, it's not a bad pickup

[nhspike]

Did you reflow your spring-claw ground?
I've had those get funky over time and just need a re-heat.
Just a thought!

[Franx]

Thanx for responding, Spike ! But I've double-checked that before. I'm pretty sure, it's a shielding issue - I'll know it next week ...

But .... yesterday I took out the EMG'd Dinky Rev. (not to be annoyed by that hum) - switched on the amp and heard:
Klak ... Klak ... Klak ... (and so on) - WTF I thought !
Thank God I'm so smart () and I solved this one pretty fast;
the guys at the horse-stable had installed a crappy power set for one of their pasture fences - I turned it off, the Klak was gone !

Good sig, by the way.

[nhspike]

Thanks
LOL! Well that was a good, quick diagnosis!
I hope them boys don't rent pigs!

[SEEGERMANY]

Spike told me that he has a problem with "body hum" each morning after coffee and bran muffins.

[Franx]

Yes, yes ...

I was actually wondering, if "body hum" might mean something different/else !?!
Sometimes, it ain't easy for a non-native-English speaker !

[nhspike]

If it has anything at all to do with a hummer, count me the hell in!

[Newc]

Giving and receiving?


The hum would be expected when being near the amp, especially since it goes away when you turn to and fro in front of the amp. Sounds like you created a magnetic field between the pickups and speakers by standing too close.

[Franx]

Sounds like you created a magnetic field between the pickups and speakers by standing too close.

That sounds plausible, as I noticed last night, that it's almost gone, when I move sidewards away from the cab !

What would you call "standing too close" ? I'm usually 6-10 ft. directly in front of my amp/cab;

What about some extra-shielding the cavity and/or the pickup ? Would that make any sense ?

[Newc]

Depends on the volume mostly. It's not really a good idea to face the speakers at anything above bedroom volume. Sound comes from the speakers and vibrates the coils in the pickups, which comes through the speakers, which vibrates the coils in the pickups, which comes through the speakers, ad infinitum.

It's a type of feedback loop. Feedback isn't just the high screechy kind. Feedback covers any sort of looping that "feeds back into the source".

Extra shielding will not really help. You'd need either weaker pickups, lower amp volume, or face away from the amp.

[nhspike]

Giving and receiving?

Damn!
Left me-self wide open for that one.

:ROTF: