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Topic: USB control cables - ground loop solutions? |
David Mason
From: Cambridge, MD, USA
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Posted 10 Aug 2015 11:13 am
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I have a couple of audio devices with handy computer software that lets you get inside and do some deep editing of parameters, but if I've got both 1/4" audio ins & outs into a mixer and the USB cables hooked up I get a lot of noise. Supposedly you can make another cable from computer case to a mixer input that... subverts the ground loop somehow? Overrides it is maybe a better word. I read about it once but I can't find it again! Can anybody point me at it, or understand it or something? I know you can spend a lot of time and money and NOT fix hum & buzz.... |
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Stephen Cowell
From: Round Rock, Texas, USA
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Les Cargill
From: Oklahoma City, Ok, USA
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Stephen Cowell
From: Round Rock, Texas, USA
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Scott Duckworth
From: Etowah, TN Western Foothills of the Smokies
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Posted 11 Aug 2015 5:20 am
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Or you can buy just the ferrite at Radio Shack and clamp them on, or get one that you wind the cable trough. _________________ Amateur Radio Operator NA4IT (Extra)
http://www.qsl.net/na4it
I may, in fact, be nuts. However, I am screwed onto the right bolt... Jesus! |
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David Mason
From: Cambridge, MD, USA
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Posted 11 Aug 2015 7:13 am
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I bought a little assortment of ferrite beads & clamped stuff up with no effect. The thing I saw basically said something like, connect a low impedance speaker wire to the computer case, and the other end to a jack to put in the mixer? Maybe. Sleeve or center or something. I'm gonna try it today - certainly can't blow anything UP, right? (famous last woooo... BOOM!)
So, is like regular "usb noise" just an immutable curse of the Gates Demon, or something understandable? I'm pretty militant about NOT buying $100 devices when I have NO idea what I'm doing. |
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Stephen Cowell
From: Round Rock, Texas, USA
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Posted 11 Aug 2015 8:04 am
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David Mason wrote: |
I bought a little assortment of ferrite beads & clamped stuff up with no effect. The thing I saw basically said something like, connect a low impedance speaker wire to the computer case, and the other end to a jack to put in the mixer? Maybe. Sleeve or center or something. I'm gonna try it today - certainly can't blow anything UP, right? (famous last woooo... BOOM!) |
Actually, you can cause quite a shower of sparks if one piece's ground has been wired to 'hot'... I'm pretty sure you'd have noticed this before now. Use the jack's sleeve... you should just be able to touch the wire to both ends and create the loop.
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So, is like regular "usb noise" just an immutable curse of the Gates Demon, or something understandable? I'm pretty militant about NOT buying $100 devices when I have NO idea what I'm doing. |
USB has bunches of noise on it, just from doing its digital job. Also, it has noise even when nothing's going on, since there's constant polling and messaging. Your devices might not have been designed to be configured and also working at the same time... you'll need to contact the manufacturer about this. Certainly don't burn $120 before contacting them. _________________ Too much junk to list... always getting more. |
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