fast repetition

[Eric Leatha]

Greg!

If the back shoulder of the jack is just lightly grabbing the butt leather
after catching (much like a grand backcheck catches a hammer tail), look at
jack rotation.  I scratched my head on an M500 last month that had "sticky
keys" when played with the damper pedal depressed.  Everything looked good,
but when the moon was in alignment with Mars and that Hale-Bopp thing going
on, the jack would lightly rest on the back of the butt leather.
The solution?  Increase jack rotation by properly positioning the letoff
rail.  The jack tender should contact the absolute center of the letoff
button.
A challenging puzzle for my supposedly dry morning of tuning tuning tuning.


>List,
>       Greetings all! I have a dilemma I'd like to discuss with you
>all.  It is a warrantee situation and I have not yet contacted the
>manufacturer but do fully intend to. I have recieved such good advice
>and insight from you all in the past I thought I'd run this by you first
>before I get the proverbial "we've never heard of that problem before".
>       Well, here goes. This week I've run into a Yamaha MX100II
>purchased by one of my customers 2 years ago and serviced the first few
>times by the dealers technician. My customer is a good player and also a
>teacher and accompanist. She is unable to get good repetition from quite
>a few "popular" note  in the mid-section of the keyboard. The "other"
>tech increased letoff on at least two occasions to insure that the jack
>was clearing the hammer butt cushion for proper return of the jack but
>the problem still exists.
>        I have found, during my examination, that both the hammer return
>spring and the jack spring have plenty of kick to them. All parts are
>pinned well within tolerance and the action feels normal. Furthur, the
>regulation is pretty good. I've not found anything that I would normally
>look for in this type of situation. Perhaps the only clues I have are
>somewhat loose hammer butt buckskin over a fairly soft cushion and that
>the problem is more prominent with the sustain pedal engaged. Aside from
>these observations I haven't a clue. It seems that the "other" tech is
>in the dark as well.
>       I would appreciate any insight you might be able to share with me
>before I contact Yamaha and ask for their help.
>
>Thanks in advance!
>                               Greg
>--

       A musician must make music, an artist must paint, a poet must write,
if he is to be ultimately at peace with himself.  What a man can be, he
must be.
-Abraham Maslow
 Motivation and Personality, 1954

Eric Leatha, RPT
Portland, OR
tunrboy@teleport.com