This is a multi-part message in MIME format. ---------------------- multipart/alternative attachment Comments interspersed below in original post: Terry Farrell Piano Tuning & Service Tampa, Florida mfarrel2@tampabay.rr.com ----- Original Message -----=20 From: "joegum" <joegum@webtv.net> To: <pianotech@ptg.org> Sent: Saturday, January 27, 2001 10:07 PM Subject: Basic SAT III (& VTD) Questions > Hi. I had the opportunity this afternoon to experiment with an SAT = III > at a friend's home. (My first experience with a VTD... II was trained > years ago as an aural tuner.) I was led through the F-A-C procedure, = set > the temperament by device and tuned the > strip-muted middle register. (The piano wasn't significantly out of > tune and very close to pitch.) However, when I checked the octaves, > they were beating quite noticeably (one to two BPS). Is this normal? 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! 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.=20 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 may = 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). 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!). > Is it now in some circles considered acceptable for octaves to be > stretched this much? 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. > When you use a VTD in noisy conditions, how can > you have faith in what it's telling you without the benefit of aural > verification? 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) 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. 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. > If the stretch is adjustable, can the stretch be reliably > individualized for each instrument without aural verification?=20 NO! 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 can = 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? > Thanks > for letting me pop back onto the list and ask these questions. -Joe > Gumbosky =20 >=20 You are welcome. Hollar back with any questions! Good luck! ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/ca/65/e3/79/attachment.htm ---------------------- multipart/alternative attachment--
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