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Signal Noise from Surge Protectors

Posted: Tue Mar 12, 2019 1:26 pm
by HNB
In my living room (first floor) I get noise even with humbuckers because of my surge protectors. Even if nothing is plugged into them, as soon as I plug one in (even a Monster one with power filtering) a hum starts. It gets louder as I plug in any other one. Any way to get rid of this noise? I even tried using an extension cord to plug the amp in to another outlet in a different room and the noise persists. My guitars pickups are picking the noise up from them. I can't just unplug every device downstairs when I want to play and thought someone might have had this issue and figured out how to fix it. If no power strip is plugged in, it is all quiet. I even tried one at a time to see if it was just one. If I plug in any power strip (Monster or cheap-o) the noise happens.

Re: Signal Noise from Surge Protectors

Posted: Tue Mar 12, 2019 2:37 pm
by Larry Mal
I have a similar problem... first of all, see if you have any shielding in the guitar if you haven't, you might be unpleasantly surprised. I shield every damn guitar I have.

I also used ferrite cores recently.

And I also bought a quality direct box recently also.

Re: Signal Noise from Surge Protectors

Posted: Tue Mar 12, 2019 2:39 pm
by Larry Mal
And, of course, are you sure that your outlet is actually grounded?

Re: Signal Noise from Surge Protectors

Posted: Tue Mar 12, 2019 3:50 pm
by HNB
Guitars are shielded. Even with nothing plugged into the monster strip it adds noise when plugging it in. How would I check the outlet ground?

Re: Signal Noise from Surge Protectors

Posted: Tue Mar 12, 2019 4:26 pm
by Larry Mal
https://m.lowes.com/pd/southwire-analog ... gI8XPD_BwE

Something along the lines of that should tell you- they aren't expensive. Your outlet is probably grounded, but it's certainly something to rule out first one way or the other because if it's not- and just because there are three holes doesn't mean it is- then nothing else you do further down the chain is going to make any difference.

Re: Signal Noise from Surge Protectors

Posted: Thu Mar 14, 2019 12:40 pm
by øøøøøøø
What frequency is the hum?

See if you can download an app to analyze the noise

Re: Signal Noise from Surge Protectors

Posted: Thu Mar 14, 2019 3:53 pm
by HNB
No idea. I could record it, but not sure how close the noise would be on recording vs in real life though.

Re: Signal Noise from Surge Protectors

Posted: Thu Mar 14, 2019 4:37 pm
by Larry Mal
Run the recording through something like this feature in Audacity:

https://manual.audacityteam.org/man/plot_spectrum.html

Re: Signal Noise from Surge Protectors

Posted: Thu Mar 14, 2019 4:55 pm
by Larry Mal
There is also Voxengo's Span:

https://www.voxengo.com/product/span/

So, you'd just need to make a recording, and then open that file with either Voxengo ( running as a plug in inside a DAW) or Audacity should work, and then take a screen shot of that.

Built in EQs from a DAW like Logic would probably also show what Brad is looking for- and I don't know what he's looking for, except my guess is he's looking to see if it's 60 cycle hum, but I could be off base.

Regardless, just record the noise, get it into a DAW of some kind and then take a screen shot of the noise in some kind of EQ with graphic capabilities or a dedicated analyzer.

Re: Signal Noise from Surge Protectors

Posted: Thu Mar 14, 2019 5:08 pm
by HNB
Here is a video. I have a class tonight but I will try to figure out how to do that.

http://www.youtube.com/watch?v=u2c1ZK2_r4w

Re: Signal Noise from Surge Protectors

Posted: Thu Mar 14, 2019 8:17 pm
by timtam
So, just to be sure, you have your guitar plugged directly into your amp, that is plugged directly into the surge protector, which is plugged directly into the wall ? And you already said there is nothing else plugged into the surge protector.

What about if you use that extension cord to connect your amp to the surge protector in another room ? (checking if it's a proximity / induction issue or an in-circuit issue)

And does turning your pickup volume right down (but not your amp) remove the hum ?

Re: Signal Noise from Surge Protectors

Posted: Thu Mar 14, 2019 9:10 pm
by andy_tchp
Is not using the surge protector not an option here?

They have limited utility unless you have frequent voltage spikes, in which case you should be raising a case with your power company. And guitar amps would be well down the bottom of the list if I was thinking about devices that are 'sensitive' to voltage fluctuations.

Re: Signal Noise from Surge Protectors

Posted: Fri Mar 15, 2019 3:19 am
by øøøøøøø
Larry Mal wrote:
Thu Mar 14, 2019 4:55 pm
There is also Voxengo's Span:

https://www.voxengo.com/product/span/

So, you'd just need to make a recording, and then open that file with either Voxengo ( running as a plug in inside a DAW) or Audacity should work, and then take a screen shot of that.

Built in EQs from a DAW like Logic would probably also show what Brad is looking for- and I don't know what he's looking for, except my guess is he's looking to see if it's 60 cycle hum, but I could be off base.

Regardless, just record the noise, get it into a DAW of some kind and then take a screen shot of the noise in some kind of EQ with graphic capabilities or a dedicated analyzer.
The idea would be to try and narrow down the cause.

If the dominant frequency wasn’t somewhere near 60 or 120, I’d start to discount utility power, and start trying to figure out how something (in one of the strips?) might be radiating emi/rfi of some sort out into the room. Of course this is a possibility even if the hum is at 60 or 120, just trying to gather more information.

Re: Signal Noise from Surge Protectors

Posted: Fri Mar 15, 2019 3:21 am
by øøøøøøø
Oh, another question—

Can you measure the voltage coming out of your wall?

This is a super long shot, but that would rule out your strips going into some sort of protection mode (or borderline condition) due to over voltage (exhibiting strange behavior as a result).

I’m really grasping at straws, but I’m at a loss. I’ve never seen a correlation with surge protectors before with truly nothing plugged in.

Now when you say “nothing” you truly mean nothing right? Not even a lamp? Not even a phone charger? Not even stuff that’s been switched “off?”

And one more—is there anything fancy about your surge protectors, or are they just big-standard ones with a few Edison outlets and nothing else?

Re: Signal Noise from Surge Protectors

Posted: Fri Mar 15, 2019 4:00 am
by Larry Mal
Well, he says that he has a Monster surge protector with some kind of line conditioning- I'd like to know a little more about that. I recently tried to get my situation noise free (and was only somewhat successful) but I did spend some time looking into power conditioners to know that they are all not the same.

Can you show me exactly what your Monster device is?

I guess I should ask to verify that your amp is in fact equipped with a three prong cord coming from it? Not a two prong? I'm assuming it has a three but it's something to rule out.

Also, definitely double check that your outlet is in fact grounded. We'll be shooting in the dark trying to find the cause of the problem every other place otherwise with no success if that outlet isn't actually grounded. It's code here that if they put in a three hole outlet but it's not actually grounded that it has to be labelled "ungrounded", and that's exactly what they've done- there's no requirement in an old building like this to actually upgrade the wiring, unfortunately.

I had to complain to get any grounded outlets at all- I have exactly one.