Yamaha C7 tuning instability

[John Ross]

The only thing wrong, with turning the air off, while you tune, is, it will
go wonky, when they turn the A/C back on.
It would be better to face the problem, and have a stable, environment for
the piano.
Regards,
John M. Ross
Windsor, Nova Scotia, Canada
jrpiano@win.eastlink.ca
----- Original Message ----- 
From: "Kent Swafford" <kswafford@earthlink.net>
To: "College and University Technicians" <caut@ptg.org>
Sent: Thursday, June 17, 2004 5:14 PM
Subject: Re: Yamaha C7 tuning instability


> Um, I'm a little surprised no one has suggested that you inquire if the
> AC could be turned off while you tune. If the problem is the stopping
> and starting of the air flow, this should solve the problem and let you
> tune without having to hit a moving target.
>
> Kent Swafford
>
>
>
> On Jun 17, 2004, at 2:31 PM, Mark Dierauf wrote:
>
> > Thanks to all for the responses. I did check the plate screws, but even
> > my biggest square-shanked screwdriver with a wrench on it couldn't do
> > more than just crack a few of them a hair. The studio is not large and
> > there are vents everywhere, so I don't think that it's possible to get
> > this piano out of the line of fire. The blanket is a good idea for
> > tuning, but it doesn't help once I'm gone. The engineer usually either
> > removes the lid altogether or else raises it until it is vertical and
> > leaning against a piece of foam that he has located on a wall for that
> > express purpose. I was thinking about trying one of the Edwards wool
> > string covers, but I assume that this would change the sound (and
> > volume) and throw off his miking procedure. Has anybody used one of
> > these covers who could comment? Would a DC bottom cover across the top
> > of the case (in place of the lid) be likely to help?
> >
> > - Mark
> >
> > -----Original Message-----
> > From: Don Mannino [mailto:dmannino@kawaius.com]
> > Sent: Thursday, June 17, 2004 1:24 PM
> > To: 'College and University Technicians'
> > Subject: RE: Yamaha C7 tuning instability
> >
> > Mark,
> >
> > As you surmised, this problem has nothing to do with the piano, and
> > everything to do with the air changing the string's temperatures.
> >
> > The best approach is to move the piano so that it is not in a drafty
> > spot
> > during tuning, then move it back when you are done.  Make sure the
> > studio
> > owners are aware of the draftiness problem - you can demonstrate it for
> > them
> > using your tuning machine easily.  Simple zero out the display, then
> > 'huff'
> > hot air on the strings while playing it - the display will begin to
> > move
> > right away.  Well, at least it works well with my unusually large
> > quantity
> > of hot air ;-)
> >
> > This problem could possibly be solved by redirecting a heating vent, or
> > getting air deflectors for one or two vents that are blowing on the
> > piano.
> >
> > A blanket or cover draped over the piano could help during tunings,
> > too.
> >
> > Don Mannino RPT
> >
> >
> > -----Original Message-----
> > From: caut-bounces@ptg.org [mailto:caut-bounces@ptg.org] On Behalf Of
> > Mark
> > Dierauf
> > Sent: Wednesday, June 16, 2004 7:27 PM
> > To: caut@ptg.org
> > Subject: Yamaha C7 tuning instability
> >
> >
> >
> > 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. It took me quite a while to realize that this fluctuation ran
> > in
> > sync with the forced hot air heating system. Now that it's summer, the
> > air-conditioning from the same vents is having the same effect. The
> > piano
> > has a complete DC unit installed with a bottom cover, is tuned at least
> > 20x
> > annually, and is very pitch-stable in the long term. It is not located
> > in
> > direct sunlight and the temperature doesn't vary much, certainly not
> > within
> > seasons. In the winter there is a humidity control system adding
> > moisture
> > through the hot air ducts. The studio is in an old New England barn
> > that
> > had
> > several hundred thousand dollars worth of renovation, and so is very
> > well
> > finished and insulated, but in the time that it takes me to work
> > through
> > the
> > temperament the first notes tuned have already moved substantially.
> > Once
> > after chasing the pitch all through a tuning I repeated A4 for several
> > minutes and watched the pitch rise about 2 cents above the starting
> > point
> > then fall about 2 cents below. This cycle kept repeating as I watched.
> > Has
> > anyone ever seen such a problem? Did you find any solutions?
> >
> > - Mark
> >
> >
> >
> > _______________________________________________
> > caut list info: https://www.moypiano.com/resources/#archives
> >
> >
> >
> >
> >
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