In a message dated 3/4/2004 5:51:53 PM Eastern Standard Time, [log in to unmask] writes:

Now, none of these sequences explains the 5 in/s in Don Chichester's email and 5.63 in Marie's original post, although this does explain the 4.4/4.5 in/s of the Saskatchewan tapes.

Thank you, Richard.  Your explanation (ast least in my case) makes sense.  I suspect the problem IS in the mains.  And, as long as playback was from the same machine with the same main, no one would be the wiser.
Don Chichester