This is in response to a question posted sometime last week about using the same stretch numbers for every piano and altering the double octave beat function to get the stretch.
When I was studying with Jim Coleman Sr. a few years ago he taught me the method I use pretty often, which was to use a feature that was added to the SATIII (I think at his request). The manual describes it, it allows you to tune A4 directly, then take the A6 measurement for the FAC calculation, and then just save or "roll over" to the page of memory. What happens is the machine uses the A6 number times 0.8 as the A; F and C are default (8 and 6), and the A4 in the program ends up just where you set it, thereby ensuring a perfect ("perfect") A440.
The next step was to set the machine to A3 on the page, play A4 on the piano, and watch the lights. If they are still, the machine is giving you a perfect 4:2 octave there. If you want more stretch, alter DOB up and check until the lights move .5 bps or whatever you want. Then tune down from A4, and when you get to about F3 start checking the octaves against the fifths, and when the octaves get noisier than the fifths you can lower the DOB to quiet them down. Then go up from A#4, reset the DOB where you put it originally and do whatever you want from there.
The one thing that comes to mind in the original post is that I think using the same A number (for the FAC) on every piano may not be a great idea, there were some old articles about what happens when you get that wrong by Rick Baldassin (?).
Patrick Mackey
New Orleans
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