Peterson 490ST Strobe tuner....good?

[Richard Brekne]

 Bradley M. Snook wrote:

>Oh, I see, you are not unconvinced about tuning curves in general, just
>the
>ways in which they are currently being calculated. 

Yes... except perhaps the Verituner...but I am not sure enough about how it
goes about doing what it does. The other thing is the fact that the other ETD's
 guess at too many notes (82 or more of them). I know the "guesswork" is pretty
darn good... but as I said in my last..... the results seem less even as I look
closer at what they really are.  

To do the job << right >> you simply need to know the real partials ratio or
ladder for every note, and you have to have an algorithm that makes all the
right compromises to achieve the closest to whatever tuning temperament you are
trying to employ with this information.

>Yes, I completely agree.
>Even though I prefer TunLab, I really dislike the way in which it
>calculates
>the inharmonicity constant. After you measure the inharmonicity of a note,
>it condenses all that data into a single number. It is this number that is
>used to reconstruct where any given partial should be located. I really
>think that this is a serious flaw, because where the partial is, and where
>the software thinks it is, are almost always slightly different. This
>naturally gives a slight difference when one confirms the tuning aurally.

Didnt know that.... glad to tho :)
>
>It is often overlooked that it is possible to do a 'perfect' tuning curve
>manually if one is willing to invest the multitude of hours. Once every
>partial is measured, it is very easy to use a spread sheet to adjust the
>tuning curve to what ever you feel is most appropriate. Naturally no one
>has
>the time to spend on every piano, but if there is a piano that you tune
>regularly for important concert situations, it might be worth some time.

I think this is basically what Verituner claims to be able to do real time, and
why users keep reporting that its best tuning on a piano is figured on the
second, or ensueing passes. And that part of how it accomplishes this is by
relying on this ratio function you briefly point at below. It quickly nails the
partial ratios down on the fly as you tune, and uses these to continually
update the tuning for any piano note for note. Tho I do know know this for
sure.

>One
>more thing: as long as you know the fundamental/partial ratio, you can use
>any partial to tune any given note. For example if I know that the 2nd
>partial is 2.00271895424837:1 and the 3rd partial is 3.00965728900256:1,
>tuning either of these partials will produce the same results for the
>fundamental and all the other partials.
>



>> I agree its interesting, but I am not sure I agree with your second
>point.
>To
>> be sure there is more information provided. That doesn't at the same time
>mean
>> that less information is actually being used.
>
>I was trying to say, that software, in general, allows for the utilization
>of more information. For example, if you were to measure all the relevant
>partials of the piano, software could assist you in the positioning of a
>tuning curve based on many different approaches. You could monitor the
>progression of 3rds, or whatever kind of interval you think is important.
>

I'll go along with that alright.... its just that I wonder how much of this is
actually being used by tuners... Present ETD's make it very very easy .... not
to say outright seductive... to just follow the dial...and perhaps make a
couple aural adjustments (that may or may not be justifiable) along the way.
Software that does what you describe above is not yet out there.. (or what ?)
tho some of us have been asking for it for some time now. 

>
>Bradley M. Snook

Cheers

RicB
Richard Brekne
RPT NPTF
Griegakadamiet UiB