David, Don't forget that after you've offset the pitch, you've then gone through the FAC procedure which requires you to tune A4 at it's second partial (A5) and then read it at A6 to get the A offset. In other words, you've changed that A4 that you measured to offset pitch when you established the FAC numbers. So, the fact that A4 is now flat is because you've changed it from where it was, no? Did I miss something? Hope that helps. William R. Monroe On Mon, Aug 3, 2009 at 3:41 PM, David Nereson <da88ve at gmail.com> wrote: > First of all, I did call Inventronics about this first, but just couldn't > seem to get "on the same page." > This time of year, most pianos are sharp from summer humidity. Rather > than lower them all down to A440, knowing they'll need a pitch raise in > November if I do, I just tune them sharp. This requires offsetting the SAT > to a sharper pitch. > Following the outlined procedure in the instruction manual, I turn the > unit on, press Tune, then play A4 on the piano, then press the Cents Up > button on the SAT (III) until the lights stop, then press Shift, Reset. The > unit should now be offset to the higher pitch. Then I go ahead and measure > the SAT numbers and store them to a page in memory. Before starting in to > tune, I go to A4 on the SAT and play A4 on the piano to make sure the lights > are still stopped, i.e., that the unit is offset to the pitch of A4. > Here's the problem: the lights are never stopped at A4 after performing > the offset. They're always rotating counterclockwise, indicating that A4 is > flat! Well, I don't want to raise the piano any sharper! Why, after having > supposedly offset the unit's reference point, does it still show A4 as flat? > Should I have A5 or A6 in the window when I offset? (I've tried both, and > it doesn't seem to make any difference.) The guy at Inventronics said to > "drop down a couple cents," or to "leave off a couple cents" or something > like that, but I'm not sure what he meant. > In reality, I don't raise the whole piano to the sharpness of the low > tenor, which is usually the sharpest area of the piano. I'll lower the low > tenor some, leave the treble where it is, and maybe pull the bass up a tad. > On older pianos, I don't like to have to pull the bass up ANY, because of > possible string breakage, but if I don't then I have to lower all of the > tenor and treble, and do a pitch raise when November comes along. And these > school systems don't want to tune more than once a year if they can get away > with it. > But I digressed. Why don't the lights stand still after having > supposedly offset the pitch? > --David Nereson, RPT > > > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/pianotech.php/attachments/20090804/6a43792f/attachment.htm>
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