On Wed, 12 Jul 2006 21:59:19 -0400, pancake
wrote:

Perhaps I was incorrect in calling it AGC, the data sheet on the chip
calls it ALC . Regardless, it sucks up unwanted noise from the audio.

Sounds like a squelch control. It turns the audio off if there's just
background noise?

There's something being fed to that pin on the chip. Either ground
the pin or connect it to the positive rail - one or the other is
effectively "off" for the function. If you have a voltmeter, just
check which way the voltage goes to cut off the audio - you want the
other voltage on it constantly.