Stereo Whine

["Al Powell" <APOWELL@agcom.tamu.edu>]

> From: treilley_at_BANKMARK@conseco.com (treilley)
> 
>      I put in a rear amp and speakers to replace OEM last weekend.  The 
>      problem is that I have an alternator whine present.  I have grounded 
>      the amp more than sufficiently(12 guage to seat belt mount) but stil 
>      have the whine.  I connected the amp ground to the receiver(Alpine) 
>      ground and grounded that behind dash to 2 diff locations in addition 
>      to the ground wire above.  This reduced the whine, but it is still 
>      there.  Noise filters from Radio Shack do no good.  What is wrong?
>      
>      
>      amp ground-----------rear seat belt mount under rear seat
>                        |
>                        |            
>      receiver ground------OEM radio ground
>                          |
>                          |
>                           ---bare metal under dash that ohmed out as ground
>      

Tim - suggest you run longer, heavy guage wires and gound ALL devices 
at the same point - on the same screw or bolt.  This helps, but may 
not eliminate whine.  You also might try to take the amp power 
lead direct from the battery...and turn on with relay.  I dunno but 
what a big capacitor may not still be necessary off the power 
input....my success with killing rising/falling alternator whine has 
not been as good as I'd like.

There are filters which are transformers and others which are caps - 
don't know which you're currently using.  If Radio Shack doesn't hack 
it, you might (after trying common grounding and taking + from 
battery) stop at a good stereo shop and ask for filtering 
recommendations.  I'd be outa tricks at that point mineownself...

Cheers....


Al Powell                           Voice:  409/845-2807
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