The let-off has a 1.5 mm(about one sixteenth of an inch) difference between bass and treble,this is a good compensation for the difference between key ratios. For most pianos,the manufacture recommend bigger let-off on bass section(3mm is recommended by Germany steinway) and smaller treble let-off(1.5mm recommend by Germany Steinway). The 1.5 mm difference could compensate the key ratio by 0.15(assuming that the key dip is 10 mm).This SD-10 action has only a 0.02(0.54 minus 0.52) difference,I don't think you have to change the key dip if you want to keep the blowing distance the same and the let-off tapered. Of course,if you prefer to spent a little more time to taper the dip,it could turns out to be "better",but I don't think the "improvement" will be very noticeable. Just my opinion. Baoli Liu > > ----- Original Message ----- > From: "Phillip Ford" <fordpiano@earthlink.net> > To: "pianotech" <pianotech@ptg.org> > Sent: August 14, 2002 9:47 AM > Subject: More dip in bass > > > > > The topic of a graduated keydip from bottom to top, > or more keydip in the > bass, came up in a discussion that I had with David > Love about the action > from > a Baldwin SD-10 that I'm rebuilding. This action > has an angled balance rail > and an angled capstan line (in other words not > parallel to the front of the > keys or the keyslip), like a Steinway D action. The > key ratios vary a bit > from the bottom end to the top end of the keyboard. > The keys at the bottom > end have a key ratio of .52 and those at the top end > have a key ratio of > .54. > The action is Renner and of good quality. I don't > know if this change in > ratio was deliberate or accidental. The result of > this is, unless I change > the capstan locations, that the blow distance or the > keydip must be > graduated > from one end of the keyboard to the other for all > the notes to have the same > aftertouch. > > Have any of you seen other actions with a graduated > key ratio that you > thought > was deliberate? > > My own personal feeling is that more keydip in the > bass feels natural and I > often set actions up like this. Pianists who have > given feedback have > seemed > to like the actions, but I've never done a direct > A-B comparison between > uniform keydip and keydip graduated from bottom to > top to see if they prefer > the graduated keydip. Any thoughts about this? Any > feedback from pianists > on > this? > > Phil Ford > > > > Phillip Ford > Piano Service & Restoration > 1777 Yosemite Ave - 215 > San Francisco, CA 94124 > > > > __________________________________________________ Do You Yahoo!? HotJobs - Search Thousands of New Jobs http://www.hotjobs.com
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