Info on Ground Loops and Hum

DJ~eZ

Participant
Jan 7, 2012
4
Az
www.soundcloud.com
Not sure if this has all been covered but When I started to Dj'ing with a laptop, I soon found out that everytime I plugged the PSU into the laptop there was this 60hz hum and weired noise like hash noise from the changing curcuit of the laptop/PSU, Going back to my electronics college days me and a buch of guys use to be on C.B Radios and I recall having this huge desk mic, but every time I was to hit the ptt bar this thing would put out a 60hz hum over the audio ckt. no matter what I did, so I went to the library to look up audio curcuits, I recall one where they had to use a Audio isolaction transfomer and that cured the humm issues with my Audio on the big mic.
I wnent to radio shack and bought 2 Audio isolaction transfomers (one for each channel L & R) I applided this idea to my laptop audio output, and Wha-lar the 60 hz and hash noise stopped and now could turn up the audio pre gain with no noise or hum.

if your good with a soldering iron and like to make and or repair your own equipment check out the links:

http://www.cliftonlaboratories.com/userimages/softro29.jpg
http://www.lib.uchicago.edu/~dean/blog/isolation-transformer.png

if you would like to contact me about audio issues pleas P.M me
Tnx

Dj~Ez
 

Proformance

DJ Extraordinaire
Nov 6, 2006
3,275
The most useful thing to know about ground loops is that the term is PLURAL. If you approach the problem with the mindset of a single loop - then you may be running in cirlces for a very long time. To solve the problem requires a systems mindset and a modular view.

Ground loops can also occur internally - down to a single faulty piece of gear.
 
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IceBurghDJ

DJ Extraordinaire
Apr 17, 2015
1,671
57
Western Pennsylvania
iceburghdj.com
Had a hum/noise/static last night.
Newer looking venue but not great electrical (one of two outlest at gazebo was dead).

I plug everything into one power strip and that into one outlet. Rarely, very rarely, have an issue. Last night the second speaker was in a separate outlet and fed via wireless signal (alto stealth).

BOTH speakers had terrible noise/static/hum. Made no sense to me, put a 2 prong adapter on the power strip into the wall and it went away in both speakers.

Same equipment I use all the time without issues.
 

steve149

Veni, Vidi, Lusi
Staff member
Sep 26, 2011
32,350
Prospect, CT
Had a hum/noise/static last night.
Newer looking venue but not great electrical (one of two outlest at gazebo was dead).

I plug everything into one power strip and that into one outlet. Rarely, very rarely, have an issue. Last night the second speaker was in a separate outlet and fed via wireless signal (alto stealth).

BOTH speakers had terrible noise/static/hum. Made no sense to me, put a 2 prong adapter on the power strip into the wall and it went away in both speakers.

Same equipment I use all the time without issues.
Be very careful using a "cheater" adapter to bypass ground .. it will void almost any liability insurance if something happens.
 
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steve149

Veni, Vidi, Lusi
Staff member
Sep 26, 2011
32,350
Prospect, CT
Only if they catch you using it.
This is one of those .. "Just Say No" things. There are better solutions with power conditioners or hum-x units. Units that pull a lot of current (powered speakers/subs and amps) really need to have a power path to ground. One thing I would never risk.