Yamaha C7 tuning instability

[Jeff Tanner]

Hi Mark,
No solutions, but similar experiences.  I recently tuned a Yamaha - C2, 
I think - which had been stored while a new sanctuary was being built.  
They put the piano back in the sanctuary on Monday, and I tuned it on 
Friday before they were to have their first service on Sunday.  I sat 
down to tune, and noticed the air in the room was fairly cool.  I 
started tuning the bass, and very few changes to the tuning were 
needed.  As I got into the low tenor, it was a little on the low side.  
I tuned up through middle C and noticed the low tenor had dropped back 
almost back to where it had been, so I tuned it again.  I tuned all the 
way through the piano, and found again that the low tenor had dropped 
well below pitch again.  It was then that I noticed that the bass, 
which had been right on when I began, was now between 4 and 8 cents 
flat all the way across!  I also had to completely retune the entire 
piano, this being the 4th pass for the low tenor.  I was also beginning 
to notice that the air in the room was warming up.  Apparently the air 
conditioning had been cut off or the setting raised not long after I 
arrived.

I spent about 2 1/2 hours trying to get that piano tuned stable enough 
that I could leave!  I had not used the pitch raise feature on my SAT 
III, because when I measured several notes before I began, the pitch 
was so close it didn't seem to warrant using the pitch raise.  I don't 
like to use the pitch raise feature when the pitch is close because not 
every note will be at the same deviation - particularly if the previous 
tuner tuned aurally.

This is not an unusual experience for me with Asian pianos in churches, 
and there is something about the feel of the Yamaha pins/pinblock as 
they age that seems to make it more difficult to stabilize the pitch as 
well.

Regards,
Jeff

On Wednesday, June 16, 2004, at 10:27 PM, Mark Dierauf wrote:

>
> I take care of an older Yamaha at a recording studio that has a tuning
> instability problem that I've never encountered on any other piano - 
> the
> pitch fluctuates by as much as 3 or 4 cents over the course of only a
> few minutes.