Mathew, > Could you nice people suggest a good voltage controlled amp chip > (audio) for Some possibilities are: Analog Devices SSM-2018T (single channel VCA) That Corporation 2180 (single channel VCA) Crystal Semiconductor CS3310 (two channel digital volume control) The Crystal part can be interfaced directly to a PIC. The two VCA's have analog control ports and will require some sort of D/A conversion to interface to a PIC. Kelly Kohls, N5TLE Dallas, TX Email: kkohls@juno.com OR n5tle@qsl.net Homepage: http://www.qsl.net/n5tle/ ___________________________________________________________________ Get the Internet just the way you want it. Free software, free e-mail, and free Internet access for a month! Try Juno Web: http://dl.www.juno.com/dynoget/tagj.