David, the Yamaha electric grand as you describe it may be a relatively new Yamaha digital grand model called a GT1, GT2 or GT7...no strings, optic sensing controls velocity information, 30meg piano sample voice, etc. A much earlier somewhat portable electric grand was the Yamaha CP70B and CP80 model which did have strings. I'm going to comment to the various points of your post assuming this is a GT1 2 or 7 digital grand. Comments: A great deal of the "control" that a pianist attains with any amplified keyboard instrument has to do with how loud the volume control is...If the volume is on the loud side, the pianist backs off and the touch seems "light". Alternately, making the amplified volume soft makes the pianist work harder. The closest comparison I can think of is when a well regulated/weighted regular piano (built with hammers, strings, soundboard) still feels "light" or difficult to control to a pianist because the hammers are hard and are producing way too much volume. In other words the same effort by the pianist produces too much volume as compared to other (well-adjusted including voicing) pianos. I believe releading the keys on any piano should only be considered after a piano is properly regulated and voiced (I'm talking pianos with real hammers here of course). Consider that the factory weighting on a new Yamaha is probably pretty good and within manufacturer's specs - at least I certainly don't get many calls about too light action adjustments on new Yamaha grands. The swing test - use the technique Yamaha uses at the factory - hold the hammer shank shank and flange w/screw in place in a straight horizontal line...the shank should slowly move down when released. Dealing with friction such as tight balance key holes ...yes. Often this procedure involves cleaning the balance pins first before using the easing tool. Raising the black key height - Yamaha spec. is 12 mm. above whites. I would suggest not to consider going beyond this until you have addressed your VERY LITTLE AFTERTOUCH assessment...This is quite probably a major concern for this pianist (Graduate of piano Bmus), especially since for this digital grand to feel similarly to a regular grand the aftertouch and total feeling of action responsiveness has to feel like other grand actions. The usual regulation aftertouch procedures work well for this piano...however, if you are considering to change the key height adjustment considerably, please consider that there is a sensing system under the keys that could be affected. Checking both the hammer sensor and the sensor under the keys is also part of regulating this piano. A misadjusted sensor can possibly result in volume control (velocity) information that isn't correct. David, If you are needing a service manual please contact me with the exact model of this piano and your address. Good luck, Ron Giesbrecht, Piano Service Manager, Yamaha Canada Music Ltd. (416)298-1311 ext.2303 rgiesbrech@yamaha.ca -----Original Message----- From: David Renaud <studiorenaud@qc.aibn.com> To: Pianotech List <pianotech@ptg.org> Date: Friday, January 08, 1999 9:17 PM Subject: Yamaha electric grand >My first experience with such a beast. > >The "Piano" > >I have a client with a Yamaha electric grand, it has >wippens, shanks.Hammers appears >to be plastic, impregnated with graphite or like substance. > >It is a grand action, adjustable as such, but the hammers >strike a solid barrier,, a metal tab attatched low on the shank >enters a switch triggering the velocity sensitive electronics. > >The problem > >Client says touch too light. >She is a graduate of piano--B.Mus. >Although she realizes what she has, wants >to know if I can improve touch. > >What she really wants is more control. >Another tech. wants to just stick lead >in the keys, She knew me from university, >and requested I take a look: > >SO---- here's what I found. > >Downweight 55 grams. >Upweight 40 grams.. >I get 11-12 swings off all tested hammers >Keys are very tight on balance rail >Hammer level is a low, very little after touch. >let off, drop, backchecking is very good. > >I'm considering doing the following: > >1)Repin to about 5-6 swings, increase friction >in action. >2)Ease balance rail whole, keys, reduce >resistance in keys. >3) Raise sharps 1 mm, and corresponding dip, >to make hand work a little harder, creating >illusion of firmer touch. >4) After this is done, add weight to key if >she at that point wants me to. > >Questions > >Anyone out there can give factory specs for these machines. > >Any experiences with these machines you want to share, >and am I missing something in this picture. > > Dave Renaud > RPT > Hull, Quebec > Canada > >
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