Uli's Web Site
[ Zathras.de - Uli's Web Site ]
Other Sites: Stories
Pix
Abi 2000
Stargate: Resurgence
Lost? Site Map!
 
 
     home | blog | moose | programming | articles >> blog

 Blog
 
 Archive
 
 Blog Topics
 

15 Most Recent [RSS]

 Less work through Xcode and shell scripts
2011-12-16 @600
 
 iTunesCantComplain released
2011-10-28 @954
 
 Dennis Ritchie deceased
2011-10-13 @359
 
 Thank you, Steve.
2011-10-06 @374
 
 Cocoa Text System everywhere...
2011-03-27 @788
 
 Blog migration
2011-01-29 @520
 
 All you need to know about the Mac keyboard
2010-08-09 @488
 
 Review: Sherlock
2010-07-31 @978
 
 Playing with Objective C on Debian
2010-05-08 @456
 
 Fruit vs. Obst
2010-05-08 @439
 
 Mixed-language ambiguity
2010-04-15 @994
 
 Uli's 12:07 AM Law
2010-04-12 @881
 
 Uli's 1:24 AM Law
2010-04-12 @874
 
 Uli's 6:28 AM Law
2010-04-12 @869
 
 Uli's 3:57 PM Law
2010-04-12 @867
 

More...

Better Music through ground loop isolators

I don't own a CD player. Nor do I have a radio or a TV. I simply have a Mac Mini with an EyeTV Hybrid (of course) and iTunes. That, however, is hooked up to an amplifier, to which some nice and old speaker boxes are attached. I got these boxes from my dad, together with an ancient tube radio, and although they're tiny, they sound terrific.

This could be a great set-up, if it wasn't for ground loops. Ground loops, essentially, are the source of the humming sound that you get in your speakers when the devices attached to your amp are "out of phase". It apparently has something to do with AC (alternating current, like it comes from wall outlets) being rectified to become DC (direct current, i.e. no-longer alternating, like batteries), and depends on which phase gets turned into "+" and which into "-" in the process. If this doesn't match, you get a humming noise in your speaker.

The cheap solution would be to plug in the power plug the other way round. The problem with computers these days (and particularly with a Mac Mini with its small form factor and only four USB ports and one FireWire port for extensibility), is that one quickly has about two dozen devices attached to the Mac, most of which have their own power supplies and may be plugged in the wrong way.

The solution is to go to some electric components shop like Conrad here in Germany (I guess Fry's would be a rough equivalent in the US), or to a car electric parts dealer: There you can get a "ground loop isolator" ("Mantelstrom-Filter"). You simply plug it between the Mac and the amplifier, close to the amp, and it will take the buzzing sound out of it.

My iTunes never sounded better. I can turn up the amp, and no noise, no humming, just music. Fantastic.

Thanks to this great tip goes out to our resident audio guru Andy. It's great to work with people like that.

Reader Comments: (RSS Feed)
No comments yet
Comment on this article:
Name:
E-Mail: (not shown, hashed for Gravatar)
Web Site URL: (optional)
Comment: (plain text only)
Please Enter the following word:
Or E-Mail Uli privately.

 
Created: 2007-10-13 @512 Last change: 2007-10-13 @536 | Home | Admin | Edit
© Copyright 2003-2014 by M. Uli Kusterer, all rights reserved.