initial documentation for Robert's amplifier for electric violin use

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+# Audio Amplifier
+
+This is an amplifier based on a National Semiconductor LM1875 that Bdale and
+Robert built to use playing around with an electric pickup on Bdale's 
+violin.  The ultimate objective is to have a modest effects chain with amp 
+and speaker that Robert can use when playing music with his friends.  We chose
+to start by building a high-quality amplifier.
+
+## LM1875
+
+This part family came to Bdale's attention for other reasons, and the 
+apparent simplicity with which a 20 watt amplifier could be built with the
+[LM1875](http://www.national.com/mpf/LM/LM1875.html) made it seem like a 
+good choice as a starting point.  Samples
+were obtained, and the first prototype wired up using the split supply 
+example application circuit in the data sheet just worked... and worked
+brilliantly!
+
+## Artifacts
+
+A schematic for this circuit based on the data sheet reference design is in
+the [hw/audio](http://git.gag.com/?p=hw/audio;a=summary) repository at 
+[git.gag.com](http://git.gag.com).