<html> <body> At 12:17 PM 12/30/2003 -0500, you wrote: <blockquote type=cite class=cite cite>If one of the coupled strings goes flat by 4 hz, the combined pitch drop would be 2 hz.   If the uncoupled string goes flat, it is business as usual for wandering unisons.   The coupler will delay the overall degrading of unisons, but not prevent, reduce or delay the failure of the uncoupled unison.   So the couplers reduce the chances of an audible unison failure over a given time period by about 50%. </blockquote> Hmmmmmmmmmmmm - yes. The audio and video clips seem to be about as good as that kind of thing can reasonably get over IP (Internet) transmission.  Pretty striking differences between "before" and "after". I wonder what they will sound like in the flesh...let alone what other effects they might produce.  Kind of hard to imagine them being made out of stainless.  What happens if they get grunged up? Ed, I'm sure we're all going to want your feedback on this!  As I think of it, such an upright as you suggest would be a really good place to test these things in a "real world" setting...still, it won't fix the jumping pins and rendering problems.... Best. Horace </body> </html>