Ground Hum Query

EG 2006

Inspired
Bit of a strange one and possibly nothing to do with the AX3. When playing guitar, there is no hum when the guitar volumes are on 10 but when I roll the volume off on the guitar a hum is introduced. When I try any of my guitars straight into an analogue valve amp there's no hum? So it seems the Axe is responding to my guitars in some weird way. I've tried the ground lift switch - no change. I've swapped guitar cables - no change.

When I touch metal - hum goes away - definite ground issue but it's across multiple guitars so I have to rule out the guitar being a factor.

Any ideas?
 
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How do you have your Axe-Fx hooked up? As in Guitar --> Axe-Fx --> ??? ---> Studio Monitors/Poweramp/etc. Are you using a surge protector/power conditioner? Are your pickups active or passive in your guitars?

I've noticed interference with just about all of my equipment under certain conditions. Such as if I sit too close to my LED keyboard I'll get buzzing in my signal with just about any pickup. Had a dimmer switch that caused a ton of hum too that was super annoying. Even using the Axe-Fx connected to the same breaker as a noisy fridge can cause interference.

If you're noticing humming only when the volume pot is lowered it could be something that is triggered through an increase in resistance such as resistor noise that can origin from the type or resistor to one that is failing.

What I'd try is using the Axe-Fx in a different room with a pair of quality headphones in isolation from the rest of your equipment to see if you're still experiencing hum then go from there diagnosing the source of the noise.
 
If you put your head to the ground and still hear the humming: It means there's a train a coming. 😁

Seriously, though: If the usual ground loop suspects don't pan out, In particular: powering connected devices from more than one outlet:
Could be the guitar cable. If the shielding is damaged, some confounding hum issues can arise.
 
If you put your head to the ground and still hear the humming: It means there's a train a coming. 😁

Seriously, though: If the usual ground loop suspects don't pan out, In particular: powering connected devices from more than one outlet:
Could be the guitar cable. If the shielding is damaged, some confounding hum issues can arise.
Nice one ;-). Seems I need to to check out the power sources. Will give it a go.
 
Thanks guys. Problem solved. I'm running guitar - axe fx - mackie monitor controller - adam sub7 - adam a7x. I'm using a Furman M10xe to power the rig. On the same power outlet I am running my PC. Power chain goes wall - Arlec RCD Power Block - Belkin Power Board - Furman/Mackie/PC.

So, long way of saying the power line is pure. Turns out, I had power cables too close to audio cables. I simply tidied up the cable runs and problem solved. Crystal clean axe fx goodness now :)
 
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