Help diagnosing hum?

F

FrenchFry

Member
So I have a persistent backround hum that is constant through my Axe 2...

It's much louder if I don't touch anything metal, as soon as I do, a large part of it goes away, but I still have a backround hum that can be heard on clean patches, even while I'm playing.

I've tried different cables/guitars, different outputs, front and rear input, etc...

Everything is going through a furman power conditioner. At this point, I'm straight into the axe, into headphones, and I still get the hum.

Any ideas to try?

Thanks!

EDIT TO ADD: I've turned off computer monitors, disconnected USB, reinstalled firmware 6.0, system reset, etc...

Hum is only introduced when guitar cable plugged into the instrument or input 1 rear. Present whether or not the cable is plugged into guitar at other end.

Persistent across my own presets as well as factory presets.
 
Last edited:
Could you cover the rest of your rig connection? Where does it go from the Axe II, what else is in the rack, kind of cabling, etc. That will help. It sounds like a simple ground loop from what you're describing, but those can come from a lot of sources. Also, the environmentals (grounded plugs, fluorescent lighting, etc) can help narrow it down.
 
Is your guitar grounded? Plug your guitar into a powered speaker or something and see if you get a hum.
 
Two possibilities I get:

I had a similar problem with my Strat once. Check to see it there is a ground wire coming from the bridge area that is supposed to tie into the grounds on the pickup pots and ultimately the input jack. If that ground connection isn't there, hum you shall get!

Also, if you are close to something with a magnetic field (recorders, stereo systems, speakers, laptops) with the guitar plugged in, it can pick up that field as a hum. See if it stops or lessens as you turn the guitar in different directions.

The good news is that it is in front of the Axe... you can rest assured the fix is easier!
 
Thanks guys, I'll keep looking I guess.

The guitar is properly grounded to bridge. This happens with all guitars, single coil, p90's, buckers.

I'll try a different electrical circuit, away from the computer.
 
Rick said:
Could you cover the rest of your rig connection? Where does it go from the Axe II, what else is in the rack, kind of cabling, etc. That will help. It sounds like a simple ground loop from what you're describing, but those can come from a lot of sources. Also, the environmentals (grounded plugs, fluorescent lighting, etc) can help narrow it down.
Click to expand...

Chain is as follows

Guitar -->
Cable -->
Axe FX 2 -->
Headphones.

USB is not plugged in. Outputs 1 and 2 are not plugged in. Only output is the headphones. I have tried a few different instrument cables. (Generic, mogami, monster).
The hum occurs as soon as I plug a cable into the axe, regardless of whether a guitar is at the other end or not.
 
FrenchFry said:
Chain is as follows

Guitar -->
Cable -->
Axe FX 2 -->
Headphones.

USB is not plugged in. Outputs 1 and 2 are not plugged in. Only output is the headphones. I have tried a few different instrument cables. (Generic, mogami, monster).
The hum occurs as soon as I plug a cable into the axe, regardless of whether a guitar is at the other end or not.
Click to expand...


Hey mate, how'd ya go with this???
I have the same issue. Guitar straight into axe > headphones, massive hum only
When a lead is plugged in.

With the ac power lead, should it have 2 or 3 prongs??
 
If the hum goes when you touch the strings it will be a shielding issue, often the back side of the control cavity. When you touch the strings your actually adding to the shielding. If you get a friend to touch the strings and let go yourself the noise should stay the same or get worse. The AxeFX is a little bit worse than a real amp for this problem but the input gate is good enough to cope! Alternatively get shielding with some copper foil.

3 prong btw.
 
Does this happen on all your presets or just some - like a high gain preset?
If common to all - sounds like some form of ground loop, and they can be a bear to find.
Make sure everything is grounded correctly in the rack and plugged into single outlet.

If you have rubber spacers under the rack mount screws, remove them (you want all devices in the rack to share the SAME ground) as that can magnify the isolation issues.
 
Ok, so I just went through the rear input (with the same lead) and suddenly all the hum is gone. The unit is silent. As soon as I go back to the front input I get nothing but hum and noise, even as soon as I plug in a lead into the input (no guitar etc)
 
Have you tried a different pair of headphones? Don't think I saw whether you did..... Eliminate the obvious

Have you tried with a speaker and/or amp? No headphones
 
Yes tried a different pair of headphones, ran through multiple speakers / monitors.
The sound only appears as soon as any lead is plugged into the FRONT input.
As soon as the lead is in it is constant humming / noise.

When I plug straight into the REAR input there is no noise at all.
I want to be able to use the front input.

I have placed the axe in a rack case, on a plastic table, on a wooden table etc. turned off all the appliances / lights / USB etc.
It's only the front input. Is it possible there is a loose connection for the input. Just seems weird that's it's only the one input
 
danielhm1 said:
Is it possible there is a loose connection for the input. Just seems weird that's it's only the one input
Click to expand...
Its possible. Contact support. They can advise you to send it back, or if you are able, have you do the minor repair, if that is the case.
 
You must log in or register to reply here.
Back
Top Bottom