Re: Stereo Noise Fixed! Thanks

[monkey@gold.interlog.com]

>I tried one of these on my QTC when I was rewiring the stereo, and much to
>my surprise the buzzing actually got worse!  The strategy that worked the best 
>for me was to run heavy gauge power and ground leads directly from the bat-
>tery to the stereo head.  I rigged a relay so that the +12 was switched on 
>and off by inserting the key in the ignition switch (using the same contact 
>that makes the warning bell ring when you open the door with the key in the 
>ignition switch).  I still can hear a small amount of whine in the rear 
>speakers if I have the volume turned way up and it is a quiet passage of 
>music, but it is acceptable.  BTW - the RS isolators use a transformer to 
>isolate the two circuits ... if anything that should adversely affect the 
>frequency response of the system (i.e. you should have a more faithful 
>reproduction without the isolator).
>
>Don't forget the fuses if you run any direct wiring from the battery!
>

Hi...
Another note is that in Audis the antennas have a built-in booster that
is powered.  There is a potential for a ground loop to develop in the antenna
run back to the head unit, especially if an after-market one is installed.
Putting a noise filter on the antenna +12v line could help as could an
inline filter on the antenna wire.  Make sure you disconnect the powered
speakers as well, if you're not using them, as they'll contribute to the
dreaded whine.
I installed an after-market head and amps in my 1990 Coupe Q20v, and
I'm STILL getting a bit of whine,  but what the heck: it's not noticeable when
the music's up and those twenty valves are "screaming"!!!

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