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<DIV>Comments interspersed below in original post:</DIV>
<DIV> </DIV>
<DIV>Terry Farrell<BR>Piano Tuning & Service<BR>Tampa, Florida<BR><A =
href="mailto:mfarrel2@tampabay.rr.com">mfarrel2@tampabay.rr.com</A></DI=
V>
<DIV> </DIV>
<DIV>----- Original Message -----
<DIV>From: "joegum" <<A
href="mailto:joegum@webtv.net">joegum@webtv.net</A>></DIV>
<DIV>To: <<A =
href="mailto:pianotech@ptg.org">pianotech@ptg.org</A>></DIV>
<DIV>Sent: Saturday, January 27, 2001 10:07 PM</DIV>
<DIV>Subject: Basic SAT III (& VTD) Questions</DIV></DIV>
<DIV><BR></DIV>
<DIV>> Hi. I had the opportunity this afternoon to experiment =
with an
SAT III<BR>> at a friend's home. (My first experience with a =
VTD... II
was trained<BR>> years ago as an aural tuner.) I was led through the =
F-A-C
procedure, set<BR>> the
temperament &n=
bsp; &nb=
sp;
by device and tuned the<BR>> strip-muted middle register. (The =
piano
wasn't significantly out of<BR>> tune and very close to pitch.) =
However, when I checked the octaves,<BR>> they were beating quite =
noticeably
(one to two BPS). Is this normal?</DIV>
<DIV> </DIV>
<DIV>On a well scaled piano with good FAC numbers (especially the "A" =
value),
the SAT calculates 1/4 to 1/2 bps for all double octaves (without =
adjustment to
the Double Octave Beat (DOB) feature). Dr. Sanderson designed the SAT =
this way
as he felt this was a "typical" or average preference for tuners. So, on =
a nice
Yamaha C7, NO this is not normal - on a rusty/crusty 1943 Betsy =
Ross
spinet, it may not be too far from that expected.......but you can =
change it to
suit your preferences!</DIV>
<DIV> </DIV>
<DIV>Understand that the FAC values (and let's just talk about the A for =
now)
represent an inharmonicity value for that region of the stringing scale. =
If you
have unrepresentative values (i.e., "bad" numbers), the calculated =
tuning may
not fit the piano well. The "A" value is the most critical of the three =
by far.
Dr. Sanderson and his son Paul do a class at the conventions where they =
go into
much detail demonstrating this. I always measure all three strings of A4 =
when
getting my "A" value (unless its a crudiano and I get a number that =
looks
OK). If they do not seem "good" (either way off from that expected or =
light
pattern was jumping all about) I will also measure the "A" value on =
several
other nearby strings (within a couple of notes away - next door first). =
Again,
A4 may not be a good representative note. It may be that the piano is =
poorly
scaled and A4 is the last string of a particular size wire that ideally =
would
have otherwise been a different size - that can certainly throw off =
an "A"
value. </DIV>
<DIV> </DIV>
<DIV>Anyway, get the most representative FAC numbers you can (time and
experience will tell you what is reasonable). My experience is that with =
"good"
FAC numbers on a good piano, the calculated tuning is right-on. BUT, if =
for
whatever reason you don't like what you hear (you have different tuning
preferences, you have bad FAC #s, a bad piano, or its just a bad day - =
poor
planetary alignment, etc.) just adjust the stretch with the DOB and you =
have
equal temperament with YOUR ideal stretch amount (scrunch it or expand =
it). That
is what the DOB is for. And you can change it in any region of the scale =
to your
preferences. You <EM>may </EM>find that you ALWAYS like more stretch =
than the
standard SAT calculation provides - you may want to start adding 0.5 (or =
whatever) to your "A" and "C" values when initially entering FAC numbers =
because
you have found that this will calculate a tuning more close to YOUR =
preferences
(you will learn to customize your initial tuning to your liking - I like =
the
standard approach and do not generally change the FAC numbers).</DIV>
<DIV> </DIV>
<DIV>This is presicely why "machine-only" tooners can - and often do - =
do poor
work. Your ears MUST dictate what you are doing. The advantage of the =
SAT is
that once you verify that your calculated tuning is to your liking (by =
doing a
few octaves and other intervals - whatever makes you comfy and happy) =
you can
then follow the machine and produce a very fine tuning without ear =
strain
(unisons excluded, of course - although on rough pianos, the top several =
notes
on my tunings often have unisons set by machine!).</DIV>
<DIV><BR>> Is it now in some circles considered acceptable for =
octaves to
be<BR>> stretched this much?</DIV>
<DIV> </DIV>
<DIV>You tell the machine exactly how much to stretch the octaves. Don't =
let the
machine tell you what is or is not acceptable. It's name is SAT, not =
Hal.</DIV>
<DIV> </DIV>
<DIV>> When you use a VTD in noisy conditions, how can<BR>> =
you have
faith in what it's telling you without the benefit of aural<BR>>
verification?</DIV>
<DIV> </DIV>
<DIV>Boy, this is one I have red hot advice on........Yesterday I was =
tuning at
a festival concert.......(see my other posts on 1st concert =
tuning)</DIV>
<DIV> </DIV>
<DIV>First of all, you ALWAYS WANT aural verification. I was able to do =
that
yesterday at the beginning of my work. I did my FAC (even on this =
Yamaha, the
three "A" values were (I think) 7.3, 7.8, and 8.4. I certainly like (and =
expected) them to be closer together (like within one or two tenths), =
but time
was critical so I used 7.8. Muted off all the "A"s, tuned them to the =
machine.
Listened to octaves and double octaves. Everything sounded right-on. =
This
combined with having tuned many similar Yamahas with excellent results, =
made me
feel totally comfy knowing that as long as I can "stop the lights", keep =
the
pitch there, and tune good unisons, we would have an excellent tuning - =
even if
I never was able to do any tests after-the-fact (which I did not have =
the
opportunity to do). If you are unsure that you have good numbers, or you =
don't
have a good piano and you don't get to listen to your tuning tests - the =
SAT may
well calculate a "bad" tuning. It only does what you tell it to =
do.</DIV>
<DIV> </DIV>
<DIV>BUT, I will go one step further. If I were tuning a Yamaha C7 in =
real nice
shape, got three "A" values that were real close to one another, all FAC =
values
were within the range of what you would expect, I would feel comfortable =
tuning
that piano with the machine and not ever being able to test the tuning =
(keep in
mind, if there is THAT much noise - no one else will be able to tell if =
it is
out of tune!). But the thing is of course, if you can tune the unisons =
by ear,
you should be able to at least listen to a few octaves to get a basic =
feel of
whether the calculated tuning will work. I will also say that I have =
never tuned
a piano in the manner just described - but if I had to, I think I =
could.</DIV>
<DIV> </DIV>
<DIV>> If the stretch is adjustable, can the stretch be
reliably<BR>> individualized for each instrument without aural
verification? </DIV>
<DIV> </DIV>
<DIV><FONT color=#ff0000 =
size=7><STRONG><EM><U>NO!</U></EM></STRONG><FONT
color=#000000 size=3> You must listen to the calculated =
tuning, and adjust
the stretch so that your ears and tuning preferences are satisfied. The =
ONLY way
to use the DOB (properly) is to listen and adjust. The only reason to =
use the
DOB is because your ears have told you that the calculated tuning is not =
what
you like. The machine MUST be manipulated so that it reflects what YOU =
like.
NEVER assume the machine knows something you don't. It <EM>can </EM>take =
three
numbers and calculate a tuning with amazing results. BUT. The SAT is =
like an
automobile. YOU MUST drive it. If you let go of the wheel you are dead. =
BUT the
automobile sure does make getting there easier, doesn't =
it?</FONT></FONT></DIV>
<DIV> </DIV>
<DIV>> Thanks<BR>> for letting me pop back onto the list and =
ask
these questions. -Joe<BR>>
Gumbosky  =
;
<BR>> <BR>You are welcome. Hollar back with any questions! Good
luck!</DIV></BODY></HTML>