• We would like to remind our members that this is a privately owned, run and supported forum. You are here at the invitation and discretion of the owners. As such, rules and standards of conduct will be applied that help keep this forum functioning as the owners desire. These include, but are not limited to, removing content and even access to the forum.

    Please give yourself a refresher on the forum rules you agreed to follow when you signed up.

Multiple Buzzing Sounds

FractalAudio

Administrator
Fractal Audio Systems
Moderator
Oh, and I should add that guitar and amp manufacturers could've done things to improve the problem. If guitars had balanced outputs this would help to reduce the noise but that would add expense so they don't do it. Even with a well shielded guitar and humbucker pickups you're still going to get some common-mode noise due to the unbalanced output. Guitars should use XLR cables or TRS cables with two conductors plus a shield. But that would add expense as the amp input would need to be balanced.
 

yeky83

Power User
Does this sound "normal" to you? I ran the L/R output 1 into my pc and recorded this with Reaper. I started on the factory preset 37 Das Metal...you can hear me moving the guitar around from the worst to the best angles in the first 40 seconds. Then I play a few chords, then scroll through some presets and finish on preset 66 Wrecked...These presets are all at the factory settings...the input noise gate is set from the factory somewhere around -80db, so it's not really doing anything here...but I wanted to show how bad the noise is.



The input meters in reaper were showing the noise peaking at about -18db, and when I play the chords it was around -8db...that's a ridiculous amount of noise. Yes, I can turn up the noise gate, but I'm trying to figure out why there's so much noise to begin with. If I turn the guitar volume knob down the axefx goes silent...so I'm sure it's the pickups. It's also better/worse depending on the preset as you can hear as I scroll through some presets in the clip. So, there has to be something that my guitars are picking up, AND there's something in the presets that amplify the noise depending on it's settings.

If by "normal" you mean pretty common, yeah, I think the lightsaber effect is a pretty common issue with guitars and high gain.

Or do you mean "normal" as in should you just live with it? Up to you. People have already suggested on this thread several things you can try. Depending on your guitar and pickup, a good shielding job might help a lot. And it would probably help to find out the various sources of EMI in your room or house, and getting rid of whatever it is.

If by "normal" you mean is the Axe-Fx behaving normally, yes it is. It's just outputting whatever you put in it. Your pickup picks up noise, gives it to the Axe-Fx, so it gives it back to ya.
 

BrianJ

Inspired
If by "normal" you mean pretty common, yeah, I think the lightsaber effect is a pretty common issue with guitars and high gain.

Or do you mean "normal" as in should you just live with it? Up to you. People have already suggested on this thread several things you can try. Depending on your guitar and pickup, a good shielding job might help a lot. And it would probably help to find out the various sources of EMI in your room or house, and getting rid of whatever it is.

If by "normal" you mean is the Axe-Fx behaving normally, yes it is. It's just outputting whatever you put in it. Your pickup picks up noise, gives it to the Axe-Fx, so it gives it back to ya.

The more gain the more the EMI will be amplified. Simple physics. Hum and noise is a fact of life. All you can do is try to minimize it, you'll never completely eliminate it. Use less gain, shield your guitars, minimize the loop area of your power cords, etc.

Thanks for the replies guys! I'll have my guitars shielded next visit to the shop. It's just amazing how much noise it picks up...and I must be one of the unlucky one's to have more EMI in my area than others...
 

BaronVonGrim

Power User
The more gain the more the EMI will be amplified. Simple physics. Hum and noise is a fact of life. All you can do is try to minimize it, you'll never completely eliminate it. Use less gain, shield your guitars, minimize the loop area of your power cords, etc.
Doing some reading on it. These are Analog based issues? Quoting " The problem comes in exposure to an unshielded amplifier to RF fields" Does the box have internal EMI filters? Probably, we haven't talked about the box.. that's a good thing I presume. If we have EMI withing the gain being amplified and EMI being picked up by the guitar or cables or air.. doesn't it all come together somewhere in the box? Would there be a reverse EMI reverse filter? If analog sensor systems are vulnerable , and these signal injection attacks are intentional and have known electromagnetic waveforms.. why can't the waveforms of amp gains, not guitars be eliminated in ways other than shielding the guitar. I'm confused about the dual topic of amp gain and guitar shielding. The main consideration seems to be amp gains, but guitar shielding only addresses a solution to half the relationship. I thought contact with the bridge eliminates the guitar influence and guitar shielding wont impact amp gain buzzing?
 

Warrior

Power User
Thanks for the replies guys! I'll have my guitars shielded next visit to the shop. It's just amazing how much noise it picks up...and I must be one of the unlucky one's to have more EMI in my area than others...

Keep us posted. I experience major EMI in my home studio as well. Always looking for solutions.
 

BrianJ

Inspired
Oh, and I should add that guitar and amp manufacturers could've done things to improve the problem. If guitars had balanced outputs this would help to reduce the noise but that would add expense so they don't do it. Even with a well shielded guitar and humbucker pickups you're still going to get some common-mode noise due to the unbalanced output. Guitars should use XLR cables or TRS cables with two conductors plus a shield. But that would add expense as the amp input would need to be balanced.

Interesting. How much do you think a balanced cable would help? I’d be open to adding a circuit to make the guitar output balanced...that could then be plugged into one of the balanced inputs on the AxeFX. I’m curious how much you think that would help though...wouldn’t the pickup still be picking up the emi even with a balanced cable?
 

DLC86

Fractal Fanatic
Oh, and I should add that guitar and amp manufacturers could've done things to improve the problem. If guitars had balanced outputs this would help to reduce the noise but that would add expense so they don't do it. Even with a well shielded guitar and humbucker pickups you're still going to get some common-mode noise due to the unbalanced output. Guitars should use XLR cables or TRS cables with two conductors plus a shield. But that would add expense as the amp input would need to be balanced.
Mmh.. Now that I think about it, my ax8 has balanced inputs.. I think I'll mod my guitars :D
 

Rex

Legend!
" The problem comes in exposure to an unshielded amplifier to RF fields"
The bulk of the problem comes from exposing the guitar to RF fields and then amplifying that.


Does the box have internal EMI filters?
The entire metal case is an EMI shield.


...why can't the waveforms of amp gains, not guitars be eliminated in ways other than shielding the guitar.
Amp gain doesn't have a waveform.


I'm confused about the dual topic of amp gain and guitar shielding. The main consideration seems to be amp gains, but guitar shielding only addresses a solution to half the relationship.
Yes, you can also reduce the effect of EMI by lowering the gain.


I thought contact with the bridge eliminates the guitar influence..
It doesn't.
 

yeky83

Power User
If we have EMI withing the gain being amplified and EMI being picked up by the guitar or cables or air.. doesn't it all come together somewhere in the box? Would there be a reverse EMI reverse filter?
Doesn't what all come together in the box? "EMI within the gain being amplified" comes from the "EMI being picked up by the guitar or cables." It's just one thing, nothing "comes together" that you could cancel out.
If analog sensor systems are vulnerable , and these signal injection attacks are intentional and have known electromagnetic waveforms..
It's not a known waveform.
why can't the waveforms of amp gains, not guitars be eliminated in ways other than shielding the guitar. I'm confused about the dual topic of amp gain and guitar shielding. The main consideration seems to be amp gains, but guitar shielding only addresses a solution to half the relationship.
There's no dual topic, you're thinking of it as if it's a separate thing, it's not. The noise you put in through the pickups gets bigger through amp gain. You should think of it as one phenomenon.


Interesting. How much do you think a balanced cable would help? I’d be open to adding a circuit to make the guitar output balanced...that could then be plugged into one of the balanced inputs on the AxeFX. I’m curious how much you think that would help though...
I was typing out a whole answer, but remembered there's google:
http://www.aviom.com/blog/balanced-vs-unbalanced/

How much it would help would depend on how much noise you're getting through your cable, in your playing situation. If you want to test it out for your situation, you can try a very very short guitar cable to see if that helps noise at all.
wouldn’t the pickup still be picking up the emi even with a balanced cable?
Yes, but the cable is also a source of noise.
 

OldSnail

Inspired
I’m not a tech, not an engeneer.
The hum/buzz is something normal but I can get rid of it if I stay away from electronic devices, screens, monitors and amp.
I try to plug electric devices directly in grounded plug in the wall. And I use instrument cable as short as possible.
 

BaronVonGrim

Power User
I’m not a tech, not an engeneer.
The hum/buzz is something normal but I can get rid of it if I stay away from electronic devices, screens, monitors and amp.
I try to plug electric devices directly in grounded plug in the wall. And I use instrument cable as short as possible.
I'm using a 12 or 15' cable. I'll try a shorter one...
I thought the power conditioner took care of some of these associated issues..and for surge protection. I'm a little surprised to hear a few people mentioning ground outlet without the p.c.
 

BaronVonGrim

Power User
Lol.. sorry old snail.. excuse my teasing. I got yelled at for it.
You guys definitely got some things right, that we have wrong.
DC doesn't have these issues? Fractal doesn't provide to you a 2 prong power cord for your outlets would it?
The metric system is another example of a better way.
Kind Regards
BVG
 

DrNick

Inspired
Oh, and I should add that guitar and amp manufacturers could've done things to improve the problem. If guitars had balanced outputs this would help to reduce the noise but that would add expense so they don't do it. Even with a well shielded guitar and humbucker pickups you're still going to get some common-mode noise due to the unbalanced output. Guitars should use XLR cables or TRS cables with two conductors plus a shield. But that would add expense as the amp input would need to be balanced.

I’ve often wondered about this, since my location suffers from EMI issues. Would it be possible for an individual to retrofit a guitar and amp (e.g. AxeFx) so as to use a TRS cable in the manner you describe?

I’m interested even if the answer is “yes, but then your gear is incompatible with other gear” but of course compatibility with standard guitars, amps, cables would be preferable.
 

pauly

Fractal Fanatic
Hi everybody...I mean hi dr nick.
I think we'd need 3 wire pickups for that to be effective.
Thanks
Pauly
 

yeky83

Power User
A built in DI on the guitar? Or an active preamp onboard the guitar, like the old Taylor Expression System? lol there's some ideas for you.
 

pauliusmm

Fractal Fanatic
So is there a way to mod guitars to have balanced outs when using with ax8? What exactly needs to be done? How effective is it?
 

Rex

Legend!
Would it be possible for an individual to retrofit a guitar and amp (e.g. AxeFx) so as to use a TRS cable in the manner you describe?
It’s possible, but it would be intrusive, and it wouldn’t be a complete solution. Much of the noise that’s induced into guitar pickups isn’t common-mode, and wouldn’t benefit from a balanced signal path.

You’d have to make your guitar’s output balanced. That would involve a balun (balanced-to-unbalanced transformer) in the guitar, or active circuitry. You’d also need a balanced input on the Axe.

Any such radical mods should really be considered part of a complete noise-reduction package, including adequate shielding for the guitar. If your guitar isn’t shielded, that would probably be your biggest win.
 

200man

Power User
What about...get a di box and take the balanced output to one of the Axe’s balanced inputs?
...but that wouldn’t get rid of what gets picked up at the guitar, only the cable, right?
 
Top Bottom