Re : RE: micro-guitar-tunings

--
Wim Hoogewerf
53, rue Dareau
75014 Paris
T�l: +33 1 43 21 23 01
Fax: +33 1 43 21 23 48

----------
>De�: "Glen Peterson" <Glen@OrganicDesign.org>
>� : <tuning@onelist.com>
>Objet�: [tuning] RE: micro-guitar-tunings
>Date�: Jeu 14 oct 1999 6:03

> There are so many other reasons guitars don't play in tune: strings
> stretching, sticky nut slots, humidity or temperature changes, careless
> tuning, heavy picking, heavy fretting, just to name a few. For these
> reasons, I haven't done much nut compensation in the past, but you are
> inspiring me to do some experiments, come up with measurements, and maybe
> make nut compensation (or at least partial compensation for average strings)
> a standard feature.

Walter Vogt showed me his measurements in 1979 when I came to his workshop
in M�hlen am neckar, a little village in the Black Forest in Germany. I did
spend a full day overthere playing the new classical guitar I ordered and
Vogt explained me many things about the way he worked. He had a specially
designed experimental instrument on which he could actually measure the
distance from the fret to the nut (any string, any position) once the result
corresponded to exact equal temperament. He used a tuning device by Wandel &
Goltermann. Several sets of the same classical strings - they were all
Augustine Blue - gave different results at every measurement. One of these
results occured in his publicity flyer for the fine-tunable guitar with
moveable frets he later devellopped. Only in six cases the result
corresponded to what you might mathematically expect. Luckily I kept this
folder:

Position Mathematically 1st String 2nd 3d 4th 5th 6th
I 36,1 mm 36,0 36,2 36,3 36,2 36,0 36,1
II 70,5 71,5 71,2 71,7 70,5 72,3 70,4
III 103,3 102,5 102,4 103,9 105,6 105,0 102,2
IV 134,2 134,6 132,6 134,0 135,8 136,0 133,2
V 163,2 164,7 159,5 163,8 164,4 164,0 163,2
VI 190,6 191,6 188,5 191,0 192,0 192,0 189,5
VII 216,4 216,7 213,5 216,6 218,0 218,3 217,0
VIII 241,0 241,0 238,2 240,0 242,6 242,8 242,8
IX 264,1 264,5 261,8 264,5 265,0 265,6 266,0
X 285,7 285,6 283,2 285,0 288,0 287,0 286,7
XI 306,0 306,0 303,5 305,0 308,3 308,0 307,4
XII 325,1 326,4 323,9 325,3 326,6 326,8 326,8
XIII 343,4 343,3 340,6 343,0 344,0 344,5 343,4
XIV 360,7 361,5 358,0 359,6 360,2 362,0 360,6
XV 376,9 377,5 374,5 375,0 376,7 378,7 377,3
XVI 392,3 393,0 390,0 390,4 391,6 394,0 392,7
XVII 406,4 407,0 404,0 404,9 407,0 408,2 407,3
XVIII 420,0 420,4 418,2 419,0 421,7 421,9 421,1
XIX 432,8 433,0 434,6

Moveable frets which are set accurately to 12tet clearly show the interest
of a tuneable nut. Vogt devellopped this later on. I have one on my guitar.
First I *tune* the six single frets in the first position. Whenever a fret
is too much out of the straight line I correct the point on the nut where
the string starts vibrating and *tune* the fret once more. Frets are
slightly *moon*shaped - like this: ) - to compensate for lateral
displacement. Due to the shape the vibrating length increases, which lowers
the tone, while the lateral displacement sharpens the tone.

Wim Hoogewerf, Paris

----------
>De�: "Glen Peterson" <Glen@OrganicDesign.org>
>� : <tuning@onelist.com>
>Objet�: [tuning] RE: micro-guitar-tunings
>Date�: Mer 20 oct 1999 17:13
>

> From: "Glen Peterson" <Glen@OrganicDesign.org>
>
>> From: "Wim Hoogewerf" <wim.hoogewerf@fnac.net>
>> Walter Vogt showed me his measurements in 1979 when I came to
>> his workshop...
>> a specially
>> designed experimental instrument on which he could actually
>> measure the
>> distance from the fret to the nut (any string, any position)
>
> Did you see this instrument? Could you describe it?

I saw it in his workshop and there's a picture in the folder showing Vogt
doing his measurements. It's a sort of rough guitar with a diamond shaped
body and a metal plate instead of the ebony fretboard. Vogt is pushing an
artificial finger in a perfect vertical way towards the string. The picture
is not detailed enough to see exactly what's going on. Any suggestions how I
could show this folder to the tuning list?
>
>> Goltermann. Several sets of the same classical strings - they were all
>> Augustine Blue - gave different results at every measurement.
>
> Using multiple sets of strings gives credibility to his results. This is
> great stuff! The chart was very interesting.
>
>> One of these
>> results occured in his publicity flyer for the fine-tunable
>> guitar with
>> moveable frets he later devellopped.
>
> Tell me more about these moveable frets. Many people have emailed me about
> things like this. Some even mentioned the crescent shaped frets. If you
> can compensate at the nut and bridge, do you still need to compensate every
> fret?
Definitely.

In the first version (about 1984) every single fret, in a crescent shape
already, had to be fixed with a small screw and could be moved about 5 mm in
both directions. That was enough to make corrections to obtain a *perfect*
equal temperament. A 1-limit just intonation, all the octaves were in tune,
which was quite a revolution for the classical guitar! A pianotuner in Paris
confirmed me that in this way at least the classical guitar tuning was
*understandable*. Thirds and fifths had their right number of beats! It
remained impossible though to set the frets to for instance Werckmeister
III. (I tried it, but missed some important steps.) I have an original Vogt
guitar on which this system has been build in in 1986. A few years later
Vogt improved the system by replacing the little screw by a small rubber
ring which fixed the single fret inside an aluminium
rail, thus allowing the fret to slide without limits. Instead of screwing
and un-screwing the fret can simply be pushed in both ways with a special
device. The fixation is solid enough to keep the fret perfectly in place
while playing. My Van der Waals guitar has been transformed with this system
about ten years ago. The first system seemed to add some very high partials
in he timbre of the guitare. On the Van der Waals guitar I didn't notice any
change in the actual sound of the instrument. This is the guitar I used to
realize John Dowland's fret settings and to play spanish renaissance music
(Narvaez, Milan, Mudarra...) in a 5-limit JI. Triple satisfaction: the sound
from an instrument of the same person who build lutes for some very famous
lutenists nowadays, perfect 5/4, 6/5 and 3/2's and very refined compositions
in which hardly ever an interval over 5-limit occurs.

The technical realization of the moveable frets is far too complicated to
explain by simple text and I'm not a technician enough myself to be really
sure about what I'm saying. Vogt worked as precice as possible, most of the
time with a 1/100 mm standard and built a huge number of special machines to
transformate the guitars and produces the frets. They were all over the
place. The system is really build in. It's not a ready-made fretboard. Be
welcome to ask any questions.

--

Wim Hoogewerf, Paris