Help! New PC, new noise! SOLVED

Guitarjon

Guitarjon

Fractal Fanatic
Hi all,

I got a new PC. It's a completely new i7 build with all new components. I use my Axe Fx III as my USB interface everyday and I use it most often to reamp through my real tube amps. I set everything up today to record with my amps but I noticed a high pitched whine coming through the amp, like a sort of ground loop. I am using the hum buster cables from the Axe Fx III to my amp but it's still there, mostly with gainy sounds.

I have tried everything I can think of: 3 different USB cables, different outlet, everything connected to the same outlet, moving the amp away, etc. As soon as I unplug the PC from the Axe Fx the noise is gone. So it is coming through the USB connection somehow. The noise gate helps of course but it doesn't remove it completely. Any help or suggestions to get rid of this noise would be very helpful. I'm basically desperate...

Thanks!
 
When you say new build, do you mean you built it from scratch? What power supply was used? How far away is the pc from everything else?
 
randyvanmartini said:
When you say new build, do you mean you built it from scratch? What power supply was used? How far away is the pc from everything else?
Click to expand...

I ordered it from a store, they put it together.

I've tried various distances but that didn't make a difference. It seems to be within the USB connection. When that connection is gone, no noise...
This is the power supply: 750 Watt Cooler Master
 
I don't think it's the shielding to be honest. At first when I had the PC a little closer there was some noise in the pickups, but moving the PC further away solved that problem.
 
Guitarjon said:
I ordered it from a store, they put it together.

I've tried various distances but that didn't make a difference. It seems to be within the USB connection. When that connection is gone, no noise...
This is the power supply: 750 Watt Cooler Master
Click to expand...
Since distance doesn’t seem to matter, it does look like there must be a problem component. The hard part as you well know is finding which one. Kind of hard when you didn’t build it, because will you void the warranty if you start changing parts? Can you get with whoever built it and let them know what’s happening with it? Motherboard or power supply would be my guess.
 
randyvanmartini said:
Since distance doesn’t seem to matter, it does look like there must be a problem component. The hard part as you well know is finding which one. Kind of hard when you didn’t build it, because will you void the warranty if you start changing parts? Can you get with whoever built it and let them know what’s happening with it? Motherboard or power supply would be my guess.
Click to expand...

It may be the CPU... My pc (Windows 10 btw) was set to the maximum performance settings, or whatever that's called in the English version. So the CPU is running at high power. Now, I tried the energy saving settings and as the CPU usage went down, the noise changed. It didn't go away, but it started to sound like a more constant beep. When I cranked it back up again, the sound changed again, more "textured" or "distorted". Hard to explain, but it seems to be CPU related... Not sure though
 
Guitarjon said:
It may be the CPU... My pc (Windows 10 btw) was set to the maximum performance settings, or whatever that's called in the English version. So the CPU is running at high power. Now, I tried the energy saving settings and as the CPU usage went down, the noise changed. It didn't go away, but it started to sound like a more constant beep. When I cranked it back up again, the sound changed again, more "textured" or "distorted". Hard to explain, but it seems to be CPU related... Not sure though
Click to expand...
I don’t know man, my CPU is de-lidded and overclocked, and is still whisper quiet. I would still say motherboard or power supply. Also, kind of curious what parts they used in the build…..premium or budget….no offense meant, just curious.
 
Guitarjon said:
Thanks for your reply, yes one side is made of tempered glass...
Click to expand...
There's your problem. Glass does not provide EMI shielding. Computers with glass windows are the dumbest thing ever invented. All the EMI goes right through the window and into your guitar pickups. You'll notice that Dell, HP, Lenovo, etc. don't sell computers with windows. Why? Because they wouldn't pass FCC/CE emissions tests.

Do a search as this has been discussed here many times before.
 
to me it sounds like emi being injected into the usb ground connection.. it takes a very small potential difference in grounding for this to be a problem. have you tried..

a) only PC and fxiii connected to power and each other (use headphones)..no amps, studio monitors nothing?
b) (a big one for me) turn off any led lights or lights on dimmers in the house?
c) a different USB socket?
d) a decent power conditioning strip?
e) a usb cable with ferrite cores?
f) there are now USB ground loop isolators, presumably all based on the ADuM4160.. worth a shot
g) opened the case and checked the case ground connections and power cable routing?
 
I looked it up, did a search but it doesn't seem to be a shielding issue to be honest. It seems to be coming from the cable. When the cable is unplugged the noise goes away. Moving the PC much further away also didn't make a difference.
 
Guitarjon said:
I looked it up, did a search but it doesn't seem to be a shielding issue to be honest. It seems to be coming from the cable. When the cable is unplugged the noise goes away. Moving the PC much further away also didn't make a difference.
Click to expand...
USB has a flaw in its design in that it causes a ground loop because both ends are grounded. You can use a USB Isolator to break the ground loop.
 
FractalAudio said:
USB has a flaw in its design in that it causes a ground loop because both ends are grounded. You can use a USB Isolator to break the ground loop.
Click to expand...

I looked for those but they either seem really hard to find or they only work with USB 1.1. I wish I could just buy one and try it...
 
FractalAudio said:
USB has a flaw in its design in that it causes a ground loop because both ends are grounded. You can use a USB Isolator to break the ground loop.
Click to expand...

Cliff, thank you so much man, that was the issue indeed! I fixed this myself with a little temporary solution but a friend is going to make me a special cable. This solved all the noise!!!! I'm so happy now because it was a very long and stressful day. Cheers!
 
Mystic38 said:
to me it sounds like emi being injected into the usb ground connection.. it takes a very small potential difference in grounding for this to be a problem. have you tried..

a) only PC and fxiii connected to power and each other (use headphones)..no amps, studio monitors nothing?
b) (a big one for me) turn off any led lights or lights on dimmers in the house?
c) a different USB socket?
d) a decent power conditioning strip?
e) a usb cable with ferrite cores?
f) there are now USB ground loop isolators, presumably all based on the ADuM4160.. worth a shot
g) opened the case and checked the case ground connections and power cable routing?
Click to expand...

Thanks for also chiming in by the way, much appreciated!
 
FractalAudio said:
There's your problem. Glass does not provide EMI shielding. Computers with glass windows are the dumbest thing ever invented. All the EMI goes right through the window and into your guitar pickups. You'll notice that Dell, HP, Lenovo, etc. don't sell computers with windows. Why? Because they wouldn't pass FCC/CE emissions tests.

Do a search as this has been discussed here many times before.
Click to expand...

This problem has been bugging the past 6 months or so because I built a PC with one of those cases a couple years ago. The noise problem wasn't as bad when I used active Fishman Fluence pickups, but since I moved back to passive pups, I get more noise. It's not bad enough to really annoy me when I'm just practicing/jamming, but if I do any recording with high gain, it does make me move to another part in the room while I track that part.

I've been thinking about building a DIY EMI shield that I could just put over/around the PC while I'm recording. Do you think something as simple as aluminum foil wrapped around a cardboard "wall" would make a significant difference? Do I need to make a complete faraday cage around the PC?

You're answer is probably, "I don't know... give it a try!" but I'm just curious since it sounds like you're knowledgeable on the topic.
 
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Guitarjon said:
Cliff, thank you so much man, that was the issue indeed! I fixed this myself with a little temporary solution but a friend is going to make me a special cable. This solved all the noise!!!! I'm so happy now because it was a very long and stressful day. Cheers!
Click to expand...
Can you share how you fixed it and what cable you modified and how?

I've tried disconnecting the ground on the USB A side, USB B side and both and neither made much of a difference. I've tried removing the ground from my power conditioner that everything is plugged into. I've tried using a APC Back-UPS BX1000 and disconnected from the power and ran off of battery. I've turned off all the lights in the house and even turned off the main circuit breaker to the house, so there was no power to anything and just ran off the UPS battery.

One thing that helped was to move my PC's from the right side of my desk to the left side and keep all my audio gear on the right side. I'm right handed, so when I sit at my desk the guitar pickups where directed at my PC's that used to be on the right side and were picking up a lot of noise. Now that I've moved my PC's, the noise has been reduced but I'm still getting a really high frequency noise above 2k. I've tried using a low pass filter as the first thing in my FX chain but it makes it lose definition and sounds muffled.
 
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