tricky noise problem...

calleballe11

calleballe11

Experienced
Hey guys!

I did my first gig with the Ultra yesterday and until then, when I was at home making patches (that sounded great, the unit really is incredible) everything was fine.

When I got to the gig i started getting wierd noise problems, more like a loud buzz than anything else.
My rig is really simple, i have the axe and then i put a Boss GT-10 in its fx loop (with a blank patch, just for using the volume pedal and tuner). I also tried the other way around. Here's where it gets tricky...

When I went straight from the linebox to the stereo output1 with 2 tele cables (without the loop, JUST the two tele and one directly to my guitar) the noise was still there, even with the axe turned OFF. However, when I went straight from the linebox to the GT-10 and used its patches, everything was fine.

I would be sooo grateful for any help, I don't really feel like returning this otherwise fine piece of equipment.
/C
 
I can guarantee you it is NOT the Axe - especially is you stated yourself that it was still there when the Axe was turned OFF !! You likely have a ground loop somewhere.

and what exactly to you mean by a linebox ? a DI ??
and what's a tele cable ?
 
Hey guys!
First of all, sorry for my english:
linebox = DI box
tele cable = 1"4 cable.

It has to be a LITTLE because of the Axe since the noise disappeared when connecting the same cables to the input of the Boss GT-10.
Maybe the Axe is more sensitive to ground loops?
I've been using it for the rest of the tour using just the balanced XLR outputs and haven't had a single issue, but i'm still curious as to why the noise was not there when I plugged into my gt-10, even with it turned on or off or full volume. Hm..
 
calleballe11 said:
Hey guys!
First of all, sorry for my english:
linebox = DI box
tele cable = 1"4 cable.

It has to be a LITTLE because of the Axe since the noise disappeared when connecting the same cables to the input of the Boss GT-10.
Maybe the Axe is more sensitive to ground loops?
I've been using it for the rest of the tour using just the balanced XLR outputs and haven't had a single issue, but i'm still curious as to why the noise was not there when I plugged into my gt-10, even with it turned on or off or full volume. Hm..
Click to expand...

The Axe Fx is not any more sensitive to ground loops than any other piece of gear, it is simply a matter of connections. Even with few connections ground loops can be a pain to find or troubleshoot.
Take your Axefx out of the rack and isolate it, plug into amp and listen, if no hum move on and add guitar....add one piece of gear at time to identify the source of the loop. I don't know what your setup looks like, but all equipment in your rig should be connected to the same power source if possible.
You may even find you need to ground your rack rails to your power source (that fixed my issues).

In your first post you mentioned you used the Axefx at home without loop issues. It sounds like you played in a venue(s) with poor grounds.
Dont give up on the Axefx...I really don't think it is the cause of your issue.
 
Yeah but you're not hearing me...
I'm curious as to why the Axe made noise but not the gt-10 when there was NO other components involved, JUST 2 cables from the axe/gt to the DI box. I had no other gear, and no guitar plugged in, tried lifting it out of the rack and putting it on different places. Overwhelming noise from the axe turned on or off, no noise from the gt-10 turned off or at full volume.

Again, i just want to know what happened, I'm not giving up on the axe =) It worked fine 5 gigs after this.
 
if it's plugged into an electrical outlet regardless if it is turned on...its in the loop- unless there is a switch or other disconnect device in between the Axefx and the power source. The loop is not necessarily caused by your equipment, there could be a lifted ground plugged anywhere into the circuit (coffee pot, other musical gear, ect) causing a loop on the circuit. When you plug into that circuit...your equipment becomes part of the loop. it may or may not cause hum depending on it polarity.
You can reverse the effect the loop has on your equipment by isolating it and lifting the ground.
http://axefxwiki.guitarlogic.org/index. ... Rear_Panel
The lift switch only works on the Balanced output ....which leads me to the next question- why do you need to plug into the DI? Perhaps the DI needed to be lifted.
 
Also worth checking your electrical outlet. In USA/Canada, you can buy a cheap outlet tester like the one shown here: http://www.outlettester.com/ ... not sure where you're located and whether a 120v/60hz tester is what you need, but you get the idea.

It happened MANY times that my gear was noisy in a venue, and a quick check with an outlet tester showed a problem (open ground, open neutral, whatever). This will produce noise.
 
Dpoirier said:
Also worth checking your electrical outlet. In USA/Canada, you can buy a cheap outlet tester like the one shown here: http://www.outlettester.com/ ... not sure where you're located and whether a 120v/60hz tester is what you need, but you get the idea.

It happened MANY times that my gear was noisy in a venue, and a quick check with an outlet tester showed a problem (open ground, open neutral, whatever). This will produce noise.
Click to expand...

+1 on the tester
 
Still no theory on why the noise disappeared in the gt-10.....

EDIT: woops sounded a bit rude, but that's really what I'm after here :)
 
the theory is that it is a ground loop. No one here can tell you what caused it , the physical circumstances of the house wiring or something plugged into it caused the loop to occur- all we know it that you have described a very classic case of ground looping.
Learning how to isolate the issue and troubleshoot it is the resolution. The link I provided above addresses that.
 
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