Overwhelming ground hum without humbusters

[Rex]

Since humbusters only work connecting the output of the FX8 to the input of the amp (they only work one direction), there's no noise being "induced" at the FX8 output

The noise comes in across the cable, not the FX8 output. In Humbuster cables, the ground on the receiving gear is connected to an input "hidden" behind the FX8's output. That input senses the hum on the ground connection and adds an equal but opposite signal to the output to cancel it.

 

[dtpancio]

What happens to the noise when you unplug your guitar cable from the Axe? If it goes away, it's electromagnetic interference being picked up by your guitar or guitar cord.

It stays.

The clean channel is very quiet. It happens with the distorted channel. But I think it's normal. It applies the gain to the noise.

I think I'll build a humbuster cable and try again. Right now I've just added a Gate/Expander block after the FXL block.

 

[Rex]

It stays.

The clean channel is very quiet. It happens with the distorted channel. But I think it's normal. It applies the gain to the noise.

I think I'll build a humbuster cable and try again. Right now I've just added a Gate/Expander block after the FXL block.

Are you sure it stays with nothing plugged into the Axe? I'd expect some hiss, but not interference, especially if gain brings it out.

 

[dtpancio]

I'm sure. But maybe it isn't interference. I'm not very familiar with this things. And I'm also italian so I can only imagine what you guys mean with hum and hiss. I guess they're kinda onomatopoeic.

 

[Rex]

I'm sure. But maybe it isn't interference. I'm not very familiar with this things. And I'm also italian so I can only imagine what you guys mean with hum and hiss. I guess they're kinda onomatopoeic.

The words "hum" and "hiss" are often misused, even among native English speakers.

Set the Synth block to White Noise or Pink Noise. That's what hiss sounds like. It's broadband, with many frequencies all at once, and it sounds disorganized, like air escaping from a tank.

Hum is the frequency of the power line — 50 Hz where you live. There may also be harmonics of that frequency.

The noise in your recording sounds like interference from electronic equipment. This kind of noise is usually radiated through the air and picked up by the guitar. It almost always goes away when the guitar is disconnected from the amp. That's why I'm surprised that it's still there when you disconnect your guitar. Maybe it's being picked up by a cable between your Axe and your amp. The fact that it increases with gain is a strong indication that the interference is getting before the instrument input jack on your amp.

 

[dtpancio]

I'm familiar with white noise, I didn't know it's what you call hiss

The fact that it increases with gain is a strong indication that the interference is getting before the instrument input jack on your amp.

Well, between the amp and the guitar sits the Axe-Fx, with two conversion AD/DA, but I don't think, like you, it's the problem. Maybe the interference is pickup up by the cable from the fx send of the Axe-Fx to the instrument input of the amp. Rather than try the experiment you suggested (which I did and I can confirm that doesn't change nothing), I can detach the cable between the twos and see if the noise goes away. But I already know the result. If I you the Axe-Fx just for post effects I don't have any noise.

I think the game changer will be the humbuster cable, even if we're not calling it "hum". Or do you think it will be not?