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Question about grounding issues for the electronically minded


chile

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I'm trying to sort out an issue I have with my NUO 2.0.. When I connect it to my new soundcard (Roland OCTA CAPTURE) and raise the input level on the channels its connected to, I end up hearing staticy noise.. It's not the preamp fuzz, but more noise from the computer.. For example if i left or right click, or close a tab/window in the comp, i hear a little noise to accompany the action. I looked it up and its likely a ground issue.. I don't really understand how to fix it though. I know for sure it's the mixer though as I unplugged everything one by one and as soon as I got to the mixer it killed the noise instantly, leaving only the minor preamp fuzz of the soundcard. The noise is loud enough to be audible in recordings and covers more frequencies than high band. I had it with the MOTU soundcard but it wasn't quite as bad.

 

I pretty much have what this guy is mentioning - http://forum.cakewalk.com/Hearing-things-computer-and-mouse-noises-through-speakers-and-headphones-m2704766.aspx

 

I'm just not sure exactly what to try.. I don't think my cables are balanced (I use XLR to TRS), or particularly well shielded (they weren't that expensive).. I could try buy some new cables but preferably I wanna try other stuff first..

 

Also the OCTA comes with a screw on the case to ground it.. How do I go about grounding it though?

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I tried grounding from sound card to the computer and hasn't done anything.. Tried grounding to the mixer ground and that didn't work either..

 

just read a little on ground loop isolators.. pretty cool.. I'm wondering on whether to get balanced shield protected cables or an isolator.. more complicated than i thought

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Guest broke

OK I just did a bit of reading on Gearslutz and it looks like you might be able to fix it without getting new cables or an isolator.

 

https://www.gearslutz.com/board/music-computers/473245-calling-all-gigabyte-mobo-users.html

 

or here

 

http://www.tomshardware.com/forum/329790-28-processor-noise-coming-speakers

 

Basically you need to change a couple of BIOS settings

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And, just to add, a correctly wired XLR to TRS will be balanced... but 1/4" cable =/= TRS cable as a lot of people think.

 

TRS will have two lines near the tip, or more accurately it will have a tip, a ring, and a sleeve section.

 

Sorry if you already know, just thought I'd stick my oar in!

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Guest rasteri

Balanced cables should in theory eliminate ground loop issues without the need for an isolator. If you're not using balanced cables you should be.

 

I honestly could rant for hours on grounding schemes and the differences between grounds/earths/shields etc but I'll save that for if I ever meet you in person :)

 

Rane has a couple of excellent notes on this : http://www.rane.com/note151.htmland http://www.rane.com/note110.html

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Guest broke

I'm not sure it's a grounding issue, it sounds more like processor noise

 

 

Quote:
Originally Posted by Animus
I think all you have to do to fix it is turn off all the c1 halt/eist/speedstepping which is fine since you really shouldn't have that stuff on for a DAW anyway. I have a gigabyte board, corsair psu and a i7 and never get the coil whine.

I had that awful sound over my monitors whenever there was I/O activity of any kind (wireless, USB, FireWire). Disabling C1 completely fixed it for me, and like others have mentioned, you should disable EIST and the C states anyway for consistent audio performance.

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I have this chile.

 

Would you describe the noise as like a high pitched screaming?

 

Mine sounded like a high sine wave mixed with a bit of white noise. Kind of like the dial tone bit of the old dial up modems.

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Guest rasteri

It's true that removing speedstep might reduce interference from the PC, but balanced cables are (theoretically) impervious to interference anyway, even if it's not technically a grounding issue.

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Sometimes I get a bit of digital chatter at the studio - my problem seems to eminate from my laptop's magsafe power adaptor. I did once have the power socket on the laptop changed which might be the origin. Regardless, i mostly solved the problem by not having my laptop plugged into the same extensions as my mixer and the PA. My laptop is now plugged into a completely different wall socket on it's own. Occasionally I get a very slight noise stil but it can be removed by wiggling the power adaptor in it's socket on the laptop.

 

It does seem that the more stuff you plug in, the more likely you are to get unwanted noises. I've often wondered if one of those rack mounted power conditioner units they use in studio would help quell such issues.

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^^^yeah, I have one piece of gear that louses up the whole signal. I have to leave it unplugged unless I'm specifically using it. But I also have a bunch of weird and old synths/sound modules.

 

In the past I've had ground loop issues because I was running gear in a chain off different power outlets. It should all be plugged into the same outlet. Otherwise you will need to do a ground lift and maybe get a furman to condition the power supply.

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thanks for all the suggestions guys, managed to sort it today! Broke you were right on it with disabling speedstepping, c states etc. Didn't think it'd work as I have an ASUS mobo, not a GB one, but it did. I now have no computer noises going on, I'm just getting preamp fuzz, which is ok since i have it turned all the way up to max sensitivity so would expect that. I am getting a buzzing though still from mixer, but i really have to have the mixer turned up a lot for it to effect a recording in a big way. And cheers chris, i didn't actually know that about TRS cables. I assumed mine were TRS, but having checked the lead it seems to be XLR to 1/4 Jack instead. Have ordered two balanced XLR to XLR cables to go from mixer to interface now.. hopefully that might get rid of the slight buzz

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Guest broke

thanks for all the suggestions guys, managed to sort it today! Broke you were right on it with disabling speedstepping, c states etc. Didn't think it'd work as I have an ASUS mobo, not a GB one, but it did. I now have no computer noises going on, I'm just getting preamp fuzz, which is ok since i have it turned all the way up to max sensitivity so would expect that.

 

Cool, I'm glad you got it sorted.

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Guest rasteri

Have ordered two balanced XLR to XLR cables to go from mixer to interface now.. hopefully that might get rid of the slight buzz

 

Let us know if it does, I like happy endings :)

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  • 5 months later...

Ok guys, everything was A OK for a long while, but now this issue is back with a new face. I now have a ground issue with a usb cable connection from my Roland SYSTEM 1 to my PC. It causes buzzing and mouse/computer changes noise etc when connected via USB... This happens regardless of whether the device is powered on or off (or whether the system1 adapter is plugged into the mains). Basically I get the buzzing when the usb cable coming from the SYSTEM 1 connects to any usb port on the mobo. I noticed that some of the usb ports are better than others.. The front case usb ports are by far the noisiest, while the back ports are less noisy, with the top usb port being the least noisiest [but I still can hear mouse movements and it would still dirty any recording while the synth is connected via USB). I've tried switching usb cables and the problem occurs on every one I've tried. I know its from the SYSTEM 1 itself because it completely disappears once I remove the usb cable connection to it. All of the cables running into my interface including the SYSTEM 1 cables are balanced [TRS].

 

I read that one fix for this sort of problem is to use the MIDI connections, but I can't do that as my interfaces MIDI ins and outs are already taken up by the Electribe, which doesn't have the usb connection option since its much older technology.

 

I'm wondering if buying a shielded USB cable would fix this [ http://www.amazon.co.uk/gp/product/B007PKPV9S?psc=1&redirect=true&ref_=ox_sc_act_title_1&smid=A1171WB52V5OD5] ? Recon a USB isolator would do the trick? This seems overly expensive though.. - http://www.amazon.co.uk/HifimeDIY-Isolator-ADUM4160-signal-isolation/dp/B00M1QQBJ0/ref=sr_1_1?ie=UTF8&qid=1447139732&sr=8-1&keywords=usb+isolator

 

I'm considering buying an internal USB hub as well as I read somewhere that if you use the connections on it solely for your sound devices it somehow separates it from the rest of the usb bollocks you have hooked up and helps with shite. Don't know how true this is though.

 

EDIT: After reading the reviews for the USB isolator I've decided to give that a go as the stories seem very similar to the issues I have. Will let you know how it goes..

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Guest rasteri

Yeah those isolators look good, only thing I would say though is that if it doesn't fix it try plugging the soundcard in through the isolator instead of the synth.

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Guest rasteri

Actually I found something you might have a problem with, if you look at the datasheet for the chip that's in the isolator it only supports low and full-speed USB devices :

 

http://www.analog.com/media/en/technical-documentation/data-sheets/ADuM4160.pdf

 

If your device uses USB High-speed (i.e. the 480Mb/sec rate of USB2) then the isolator might not work.

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no luck. didnt make a difference to system 1 [i actually think its soley the soundcard now as i noticed the sound even without the usb connected]. Soundcard wasnt working when i tried to use it with the isolator. gonna refund the device and try something else

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Guest rasteri

Grounding issues are a cunt to figure out. I guess the only thing is to unplug everything (I mean literally everything) from your computer apart from the soundcard, then start adding stuff until the sound comes back. Then you'll know what combination of devices is causing it.

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I tried that earlier with a few things but will go over it with everything now. Just ordered some of these in various lengths for my USB midi devices and interface, hopefully will do something or ive spent 40 quid on usb cables lol.. I found out from returning the isolator that amazon now to do collections so you dont even have to drop off the item youre returning at a local collect plus branch. Also they refund the item + postage cost, which is handy since my impatient ass paid the 8 quid for the 1 day delivery..

 

http://www.amazon.co.uk/gp/product/B007PKPV9S?keywords=LINDY%20CROMO%20USB%202.0%20Type%20A%20to%20B%20Ca&qid=1447818541&ref_=sr_1_fkmr0_1&sr=8-1-fkmr0

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