Can't figure out hum issue..

tfodor

tfodor

Inspired
Hey guys,

Attached is an audio file with some noise in it. The recording is exactly what I hear when plugged directly into my axe fx (not the DAW) happens across all guitars, and over all cables. I recently made a substantial firmware update, moved apartments, etc so Im having trouble locking down the variables. I think it has something to do with the power in this room. The noise occurs over all presets, but this particular one was a clean amp and cab, thats it.

Any ideas? Update: When I turn off the noise gate, the noise is constant whether im playing or not. This happens over all amps and cabs no matter how clean or dirty. Update 2: Noise is less when the bright switch is off..

It would be equally helpful if someone could post a link to a gain-staging video. Im starting to think thats my issue. Thanks! Here's the clip:

https://we.tl/F7soiAHkNQ
 
Hi,
It sounds like a light dimmer to me - do you have dimmers? If so, turn them up all the way, or turn the lights off. It could also be a dimmer in an adjacent apartment on the same circuit.
Thanks
Pauly
 
here's a new tidbit of info. If I til my guitar up or down, the sound changes and is definitely being affected by the angle my guitar is to the axe. Could both my guitars pickups be microphonic?
 
tfodor said:
here's a new tidbit of info. If I til my guitar up or down, the sound changes and is definitely being affected by the angle my guitar is to the axe. Could both my guitars pickups be microphonic?
Click to expand...
No. Your pickups are picking up radio-frequency interference. Note that when you change the angle between your guitar and the Axe, you're also changing the angle between your guitar and everything else in the room. :)
 
tfodor said:
here's a new tidbit of info. If I til my guitar up or down, the sound changes and is definitely being affected by the angle my guitar is to the axe. Could both my guitars pickups be microphonic?
Click to expand...

What you've described is not microphonic pickups. There may be an ambient electromagnetic field that's being "heard" by your pickups.

If you're playing single-coil PUs, switching to a guitar with humbuckers will help. If you're already playing humbuckers, well...

Check grounding of the wall outlet. Even if you have a grounding outlet, the ground may not be wired. That'll inject hum in much the same way as an ambient EM field.
 
TieDyedDevil said:
What you've described is not microphonic pickups. There may be an ambient electromagnetic field that's being "heard" by your pickups.
Click to expand...
Bingo.


TieDyedDevil said:
If you're playing single-coil PUs, switching to a guitar with humbuckers will help. If you're already playing humbuckers, well...
Click to expand...
+1.


TieDyedDevil said:
Check grounding of the wall outlet. Even if you have a grounding outlet, the ground may not be wired. That'll inject hum in much the same way as an ambient EM field.
Click to expand...
What @tfodor is describing is an RFI issue, not a grounding issue. Different mechanism with different results.
 
Do you have a computer nearby. I have a friend who has a real bad hum due to his computer. If so Try turning it off.
 
bdrepko said:
Do you have a computer nearby. I have a friend who has a real bad hum due to his computer. If so Try turning it off.
Click to expand...

One of the worst culprits is Wi-Fi access points. Got a Wi-Fi router in the room? Hold your guitar close to it and see what that sounds like.
 
Rex said:
One of the worst culprits is Wi-Fi access points. Got a Wi-Fi router in the room? Hold your guitar close to it and see what that sounds like.
Click to expand...
The problem my friend had, was that he had like 6 hard drives in his computer. The noise from them was pretty loud.
 
Rex said:
Bl
What @tfodor is describing is an RFI issue, not a grounding issue. Different mechanism with different results.
Click to expand...
Rex said:
What @tfodor is describing is an RFI issue, not a grounding issue. Different mechanism with different results.
Click to expand...

If the safety ground floats, the induced voltage can mimic an RFI issue.

In this case, the position sensitivity says that there's an ambient EM field affecting the pickups. But a floating ground can exacerbate the problem.
 
TieDyedDevil said:
If the safety ground floats, the induced voltage can mimic an RFI issue.

In this case, the position sensitivity says that there's an ambient EM field affecting the pickups. But a floating ground can exacerbate the problem.
Click to expand...
"Exacerbate" is the operative word. A floating ground can make the system more susceptible to RFI, but it's still RFI.


For the record, I don't hear much to object to in the clip that @tfodor posted.
 
Check outlet for proper ground and phasing.
Make sure your guitar has decent shielding. Most don't.
Mount rack gear with a plastic tab behind and in front of the rack ears.
Plug all gear into the same outlet for single path to ground.
 
Typical power grid hum. Neon lights with electronic balast or transformer can be a cause. Tried using classic filament bulbs, halogen or Led ? Any fridge or hvac running in the house ?
Older neon light with magnetic ballast are a disaster but I don't believe anyone still has these.
You might try to change the placement of your axe fx also or another power outlet.
 
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