This is a multi-part message in MIME format. ---------------------- multipart/alternative attachment Greetings -- =20 I did a dealer prep on a brand new, fresh out-of-the-box, Yamaha MX500 P upright today. Every single note double-struck when played softly. I = checked regulation and had to adjust lost motion on every key. Let-off also = needed to be adjusted, but only on about 10 keys. When I finished these two adjustments the regulation may not have been perfect but it was = certainly close enough. Still, every single note was double striking when played softly. (Definition of "softly": Playing the note faster then when you = are checking let-off but slower than it takes to actually check.) =20 What I am witnessing is this: When I play the note, just before the jack releases from under the butt the hammer jumps off the jack prematurely = and strikes the string. After striking the string the hammer then bounces = back onto the jack, which is still in it's pre-release position. Continuing through the keystroke results in the hammer striking the note a second = time as the jack finally releases from under the butt.=20 =20 This was something new to the store manager so I called an associate. He suggested I go through the routine I had just completed, but otherwise = could offer no further suggestion. OK, so I decided to tune the thing while I pondered the matter further.=20 =20 Aha! Tuning finished. Let's see what the other Yamaha uprights are = doing. I checked six other, (not used), Yamaha uprights on the floor, (none of = which I had prepped, but all of them allegedly prepped), and every single one = of them exhibited the same double-strike behavior. For comparison I then checked some NON Yamaha uprights and they all behaved properly. I = finally checked the showroom Yamaha action model, and it, too, was behaving correctly. BUT... It was then that I noticed that all the Yamahas used = in this test had plastic jacks. The Yamaha action model, as well as the non-Yamaha uprights used in this test, all had wooden jacks.=20 =20 That's all the clues I have. Anybody have any idea what's going on, and = what can be done to correct it? =20 Geoff Sykes Assoc. Los Angeles Chapter ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/ea/db/af/d6/attachment.htm ---------------------- multipart/alternative attachment--
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