Ultralite distant squeels from laptop power

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Discussion related to installation, configuration and use of MOTU hardware such as MIDI interfaces, audio interfaces, etc. with Windows
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chrislewis
Posts: 2
Joined: Tue May 22, 2007 12:43 pm
Primary DAW OS: Unspecified

Ultralite distant squeels from laptop power

Post by chrislewis »

I'm using the ultralite with a laptop running cubase. Everything is great as long as I don't have the power lead in the back of the laptop. As soon as I do I get what I can discribe as an electrical swirl/squeel through my speakers.

Any suggestions/sollutions please.
acidrecords
Posts: 89
Joined: Sun Apr 20, 2008 7:00 am
Primary DAW OS: MacOS
Location: Europe > Vienna

Post by acidrecords »

it`s a grounding problem.

1) put motu + laptop powerlead @ the same distributor box.
2) check that the powercables do not run parallel to the audio cables.
(if you are going unbalanced)

3) put a wire from the grounding on the distributor box (yours may look different :D :D ), to the metal cover of the vga output on your laptop.
Image

this should fix the problem :wink:
chrislewis
Posts: 2
Joined: Tue May 22, 2007 12:43 pm
Primary DAW OS: Unspecified

Ultralite distant squeels from laptop power

Post by chrislewis »

Cheers acidrecords

I've not tried it yet but it sounds like a good fix.
arth
Posts: 353
Joined: Thu Mar 16, 2006 12:29 pm
Primary DAW OS: MacOS
Location: Simsbury, CT, USA

Post by arth »

WARNING!

Do NOT attempt the above recommendation unless you know that the electrical system in your country has earthed ground (like most but not all of Europe), or ground linked to one of the main wires (like the US).

If it has floating ground, you may be in for a shock (literally), unless you make sure that either all the devices use ground from the same circuit, or none of them are grounded.

Some countries use a five phase system with floating ground. This has the advantage of being very resilient to occasional shorts and spikes on the overall system, including lightning strikes and ground faults, and also has a lower energy loss over large distances. It does, however, imply that the "ground" will carry a current, and the potential between ground and live varies depending on the outlet you use and which two of the five phases it is hooked up to.

And if you didn't understand any of the above, play it safe and don't do it.
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