Audio buzzing

[JoeDat]

Well, good news.  Lowering the software volume did the trick.  The sound is still there, but barely even noticeable.  I'm convinced you nailed the source being storage access interference.  I've abandoned an attempt to replace the sdcard...just don't think it's worth trying since the noise is all but gone. 
 
I admittedly saw that as a suggestion for another audio issue, but stubbornly didn't try it.  Thanks again for the support!!