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AngusG

Annoying hummm

12 posts in this topic

OK... Got a bit of an annoying hum through my Edirol FA-66 and Dell Inspiron 9300...  Played around with it, and it's only there when my laptop power supply is plugged in...  It's fine when running off the battery... What's the easiest/cheapest/most foolproof way of fixing this??  or am I doomed to go out and buy a Mac?? Thanks heaps in advance, Angus

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A mac may not fix your problem - they also experience ground loop issues.

If you can, the first course of action is to try balanced cables from your Edirol to your monitors. That's most likely TRS to TRS. Cost should be about $10

Dell also supply a bigger 90W PSU that has the earth pin removed from. It's the PA10 family. Cost is about $60, and will remove the ground loop issue. The latitude, precision and XPS dell laptops all ship standard with this better 90W PSU.

Last resort would be an isolation transformer from Jaycar or similar. Cost is about $20. Isolation transformers will not fix the ground loop issue but will cause a break in it hiding the symptom. Personally, the better PSU is the option i would be taking as it wil lalways work and you wont need to worry about cable and crap when you're doing gigs.

DO NOT REMOVE THE EARTH PIN FROM YOUR CURRENT PSU. It's dangerous and illegal. I know on some other web forums they suggest this, but trust me as someone who works and designs with the bitey stuff all day you DO NOT want to be removing your earth pin as it may cause you DEATH. To my knowledge, death is a serious and irreversible injury and will leave you scared for life. :(

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is there a plan B ;D

Haha... I was about to ask the same! ;D

Welcome, AG AKA P-B! ;)

EDIT: Yeah, and as J-FU stated, Macs can hum issues too, but it might just be me. I went the isolation transformer path (Jaycar) but as its the non-critical built-in soundcard with issues, not my audio interface, I'm not too concerned re sound degradation. Actually, I'm struggling to fault the isolation transformer, but that could be my clapped out hearing.

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Hehe... Thanks guys...

Been lurking on here for a while but haven't really had much time (and this buzzing's been pissing me off too much) to sit down and actually do anything...

I've got an Inspirion 9300 (with the bigger power supply) but might see if I can pinch one without the middle pin from work...  I'm using TRS-TRS leads atm... Would TRS - XLR make any difference??  Soundcard's got TRS out, monitors have TRS/XLR combo in..  (Sorry about the n00b questions)

A mate of mine with a Macbook Pro rigged it up to my sound card and didn't have the problem..

Looking forward to reading a bit more in here and hopefully having something to show for it (Don't worry, it won't all be trance ;))

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I'm using TRS-TRS leads atm... Would TRS - XLR make any difference??  Soundcard's got TRS out, monitors have TRS/XLR combo in..

Nope, won't make an ounce of difference as the electrical connections are *exactly* the same, albeit the plugs are different.

A mate of mine with a Macbook Pro rigged it up to my sound card and didn't have the problem..

Probably a silly question, but was his power plug connected too?

(Don't worry, it won't all be trance ;))

Don't be silly. This isn't that *other* forum. Everyone *loves* trance here, and electrohause, and hardstyle...

PLUR all 'round!

;)

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Probably a silly question, but was his power plug connected too?

Ummm... I'm sure it was a powerboard or powerpoint in my room...  This was going back a year ago, but I'm sure he plugged it in

Don't be silly. This isn't that *other* forum. Everyone *loves* trance here, and electrohause, and hardstyle...

Hahaha... I can't do hardstyle...  I already live with a hardstyle DJ...  It can be quite painful :S

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Don't want to re-visit old ground here (if that's possible with my 3rd post, lol) but a 2 pin is really dangerous, the earth is there for a reason.

http://www.jaycar.com.au/productView.asp?ID=AA3085&CATID=&keywords=isolator&SPECIAL=&form=KEYWORD&ProdCodeOnly=&Keyword1=&Keyword2=&pageNumber=&priceMin=&priceMax=&SUBCATID=

I use one of these at all me gigs and in the studio and although it can create a potential difference between your gear it is much much safer than a 2 pin adaptor.

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^The 2 pin is a Dell designed PSU. It's the 90W version and rather than having the earth pin removed, it has the PSU designed to not require the earth pin. Hence Dell supply it, legally, with a 2 pin adapter plug. The PSU uses a different design and does not rely on an earth path as part fo the rectifcation process.

I have the 2 pin PSU for my laptop, as does everyone else in the company i work for. These pass all OH&S requirements in every state and also pass testing under tag and test process... just like the Apple 2 pin PSU does.

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