[CAUT] Advice for achieving stability sooner?

[Ron Nossaman]

 > On Feb 8, 2010, at 6:38 PM, Jeff Tanner wrote:
 >
 >> I've found that Asian pianos do need this for some reason, 
and it
 >> doesn't always have to be right out of the box. I've used 
this
 >> technique on Asian pianos which have had tuning 
instability for years,
 >> and it settles them down. I don't know if it is the 
rendering, or if
 >> the wire stretches (which is kind of what it feels like), 
or the coil
 >> tightens, or all of the above. But you're right. This works.
 >>
 >> But why is it that I don't seem to find that American 
pianos respond
 >> the same way?
 >
Fred Sturm wrote:

> 
>     When I had a Baldwin loan program, I found it was definitely true of 
> both grands and uprights (you could almost always pound flat by 25 cents 
> of more, especially high treble, after a string and pin was otherwise 
> seemingly stable). 


I think it's pretty much got to be coming from the back scale, 
through the bridges. I find this most with Yamahas (the only 
Asian pianos I get to tune with any regularity) after even a 
slight pitch increase. One good whack drops pitch quite a bit, 
after which it's quite docile. It also happens yearly, under 
the wrong humidity cycle conditions, so I don't see any way it 
could be strings straightening around terminations. American 
pianos do it too, but it's a lot harder to make it happen. 
Perhaps the differences between bridge pin plating and 
resulting friction. Another clue that it's coming from the 
back scale is that it doesn't happen in the bass or tenor, 
where the strings are long and heavy and the back scales 
proportionately short. In the treble sections, the speaking 
lengths are short and light, with proportionately long back 
scales (all of it, not just tuned duplex). It's the same 
phenomenon that accounts for a half semitone pitch raise 
showing ragged unisons a couple of weeks afterward in spite of 
sounding pretty good when you left it. Strings creep across 
bridges all the time with temperature and humidity changes, 
never quite matching back scale tensions with the front scale, 
but always trying. Nothing ever stands still. Everything is 
always on the way to somewhere else.
Ron N