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ground loop isolator is picking up AM RADIO!!

Posted: Sat Sep 23, 2006 1:07 pm
by x00stalkr00x
I am a DJ and I have a very basic studio for recording live mixes.

So I just got the SELF POWERED KRK RP5's. I connected them to my main out rca holes on my mixer (I have a 2 channel Vestax vmc-002). Everything works great at this point, speakers are beautiful, NO FEEDBACK.

When I decide I am ready to record my mix, I take an rca cord from my RECORD OUT on the back of my mixer, use a RCA -> 1/8 inch adaptor, and plug that 1/8 inch adaptor into the back of my sound card. As soon as I do this, BUZZZZZZ MAJOR LOUD feedback.

So I went to radio shack to get a ground loop isolator to put between my computer and my mixer. This solved the rediculous feedback problem but now I'm picking up AM RADIO on anything that is connected to my computer. Example...my computer speakers...headphones that I plug into my computer...and most devastating of all...my MONITOR speakers that I use for mixing my live music.

I am about to kill myself........what is wrong now?

Posted: Tue Sep 26, 2006 2:57 am
by Aaronw
Greetings and Welcome to the site.

Start here: http://www.johnlsayers.com/phpBB2/viewtopic.php?t=3231


As far as your issue, a majority of it is caused by using unbalanced/unshielded cables.

Posted: Tue Sep 26, 2006 4:48 pm
by x00stalkr00x
Aaronw wrote:Greetings and Welcome to the site.

Start here: http://www.johnlsayers.com/phpBB2/viewtopic.php?t=3231


As far as your issue, a majority of it is caused by using unbalanced/unshielded cables.
mmm yes I just did a search and saw that RCA cables are considered an unbalanced cable and that TRS cables are considered BALANCED. I will try and use TRS cables...but first I need a mixer that supports TRS.

Posted: Tue Sep 26, 2006 11:29 pm
by Aaronw
You may also add a line filter to your AC lines.

Posted: Mon Oct 09, 2006 2:47 pm
by x00stalkr00x
a bit skeptical about buying the trs connections...

xlr cables seem to have one pin specifically for grounding.

Posted: Mon Oct 09, 2006 2:55 pm
by Aaronw
a bit skeptical about buying the trs connections...

xlr cables seem to have one pin specifically for grounding.

So does TRS (Tip, Ring, Sleeve (Ground))

Tip/Sleeve is unbalanced.

I would also suggest a braided cable (2 conductor w/ shield).