Hi Jim! I have a method similar to Kevin's to adjust the width of the octaves with the SAT III. After taking the FAC readings I tune F#4 very carefully. I then set the SAT III on B2. I play F#4 and use the double octave adjustment to stop the LED's . I found that setting the A3 - A4 octave to my liking sometimes did not make a B2 -B3 octave that worked! Using this method I find that the whole C3-C5 section sounds very nice! Richard Raskob RPT PS I have also figured out a way to have the SAT II perform a similar result but it is much more complicated. I am willing to post the steps if there is interest. The D.O. adjustment that the SAT III has makes the upgrade worthwhile all by itself! ----- Original Message ----- From: "Jim Coleman, Sr." <pianotoo@imap2.asu.edu> To: <pianotech@ptg.org> Sent: Thursday, November 30, 2000 8:21 PM Subject: Tips For SAT Users > Special help for SAT users > > The newer Sanderson AccuTuners (SAT for short) have the (FAC) > capability for predicting or calculating a tuning for a piano. > Although the measurements of F3, A4 and C6 will provide > a very good tuning for most all pianos, one may alter this > tuning to suit one's personal preferences. For example some > Technicians prefer to have their octaves very tight while others > prefer to have a little stretch in the octaves. Measuring the > 3 notes gives the instrument a pretty good idea of the slope of > the inharmonicity of the piano, but it does not tell everything > about the bridge shape or where the string sizes or type change. > Originally there was a program for measuring 6 C's of a piano > to predict the tuning, but here again, wire size changes and > bridge configurations were not known to the program. One could > measure the inharmonicity of every note on the piano, but this > would be tedious and impractical to do for each tuning job. As > a result Dr Sanderson came up with the scheme to measure only > 3 notes to still get a pretty good representation of the tuning > requirements for a particular piano. > > If a treble bridge has a hockey-stick like bend at the bottom > It is likely that some additional stretching could be advantageous > for the tuning of this piano. I am indebted to Kevin Ramsey > for this simple way of determining if additional stretch should > be welcomed. Here is his procedure: > > After measuring and computing a tuning for a piano using the > FAC capability, carefully tune the A4 to the SAT. Then press > Dn/OCT to A3, play the A4 again and notice the direction of the > LED's. If they are stationary, you would have a tight 4-2 type > octave when the A3 would be tuned to this setting. This means > that the second partial of A4 is exactly in tune with where the > 4th partial of A3 will be when it is tuned later. This is quite > understandable when you realize that the SAT (FAC) tunings tune > by the 4th partials of each note from C3 through B4. When the A4 > is played while the SAT is on A3, it is the 2nd partial of A4 > which is being viewed on the display. When the display is set > this way for the tuning of A3 later, its 4th partial will be > tuned to this setting. In essence you will have a perfect unison > between the 2nd partial of A4 and the 4th partial of A3. This > would give you an aural test where the M3rd F3-A3 would beat at > the exact same speed as the F3-A4 M10th. > > If on the other hand the LED's are rotating counterclockwise in > the above example, the octave would be narrow when the A3 is > later tuned to the A3 setting. This would result in an aural > test where the M3rd would be faster than the M10th. This would > indicate that we would need to stretch the tuning more. > > Additional stretching can be done in two ways. For those who > have the SAT III, the blue SHIFT button is depressed while the > Up/CENTS button is pressed 2 or 3 times to stretch the tuning > by .3 beats per second (bps). This will give the A3 a lower > cents setting while the A4 setting will remain the same. In > most cases this will at least make the 3rd-10th tests equal > or better. On some pianos one might wish to add a little more > stretch by increasing the Double Octave Beat control (DOb) to > .5 bps. > > For those who have the older SAT II or SAT I with the FAC > capability, they can increase the value of the A4 Stretch > number by perhaps .5 to .7 cents to accomplish the same thing. > However it is important to remember when you get up to C5 in > the tuning process that it is necessary to add the same amount > to a reset of the instrument's pitch by using the SHIFT and > RESet buttons. Two articles in the PT Journal of Apr and May > in 1997 explain this in greater detail. > > It has been noted for several years that the better tuners > prefer to stretch their octaves at least to show a half bps > difference between the M3rd F3-A3 and the M10th F3-A4 with > the 10th being the faster. This can be easily duplicated > using the SATs. > > For those still using the older single F4 Stretch number > system Rick Baldassin wrote an excellent piece on doing a > similar thing for the SOTs and the early SAT's. In this case > the reset additions need to be made between F4 and F#4. > If there is enough interest, it might be possible to get him > to repeat that for us here on pianotech. > > Jim Coleman, Sr.
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