tuning with Dampp-Chaser

[Farrell]

My bet is temperature changes. Remember, that little heater bar gets toasty. I was practicing with my new Verituner on my Boston grand yesterday for a couple hours. We have an AC vent right above the piano, but keep that vent open only a crack - the air is directed in such a way that you cannot feel any significant air movement within several feet above the piano. The AC was going off and on during my tuning. I did a couple passes with the VT to be sure everything was going to stay where I put it. Then I was comparing the tuning with my SAT III. Often the darn tuning would be closer to the SAT than to the VT! The whole tenor and bass sections were going up two cents in pitch - then I would retune - then it would go back down two cents below pitch - and back again (top two sections - they seems pretty steady). It was pretty frustrating.

We have some cooler weather coming up in the next few days. I want to repeat this exercise on a day when I do not run the AC. I'll report back. From what I have observed in other situations - going into a hot church and they turn the AC on, tuning a piano outside with the sun darting in and out from clouds, etc. - that temperature appears to be the dominant factor in short-term tuning instability.

I think I can say with some degree of confidence that a RH change from 42 to 36% is not going to change any tuning in the short term.

> Do people run into this problem? If so, would you recommend leaving the
> piano open for a while before tuning?

Yes. Yes.

Terry Farrell
  
----- Original Message ----- 
From: "Charles Neuman" <piano@charlesneuman.net>
To: <pianotech@ptg.org>
Sent: Thursday, March 21, 2002 11:53 PM
Subject: tuning with Dampp-Chaser


> Any strategies on tuning when there is a D-C installed?
> 
> When I open the piano, the humidity starts to change. After a while this
> affects notes I've already tuned.
> 
> In my case, the humidity near the action of my vertical changes from 42%
> to 36%. After a half hour or so of practicing setting a temperament, my
> first notes have drifted a bit from where they were. I assume the humidity
> change is the problem, but I suppose it could be how I set the notes.
> 
> Do people run into this problem? If so, would you recommend leaving the
> piano open for a while before tuning?
> 
> Charles Neuman
> 
>