uguntde

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Posts posted by uguntde


  1. A Blanchard is very hard to fake because his workmanship was quite exquisit. If it is a fake it is easy to identify as such. Glue marks could only be from a bad repair. The difference in price tag of a Blanchard and a fake is at least a factor of 10. Whether there were others in Blanchard's workshop who made instruments and used such a label I don't know.


  2. The reaction of rosin and linseed oil is chemically a cross-esterification. Lineolic acid gets attached to abietic acid. In solution such reactions are base catalysed. I assume that something like this is happening in hot rosin, especially, as the lime is added in water. Lime light just catalyse the ester cleavage of the abietic acid. Industrially anothet catalyst is used which I need to look up. This is just an assumption, as I know little about such chemistries.


  3. 9 hours ago, martin swan said:

    We recently sold a Tomaso Eberle to a concertmaster. It was a very archetypical Neapolitan violin - quite screechy close to the ear, not unattractive in sound but definitely "penetrating".

    His main concern was that everyone in the orchestra (particularly the strings) could hear him, and he paid a lot of attention to the articulacy of the instrument in fast passages. We tested this with a few of his colleagues in a hall, and while everyone agreed it wasn't the nicest sounding or most sophisticated instrument I took along, they/we all agreed it was the most audible and the "crispest". 

    I think if he had been a soloist, he would also have wanted a more malleable or beautiful essential tone. 

    Very polite way of judging an instrument :). Most English concertmasters (orchestra leaders) can't afford anythng like that and still find good souding instruments.


  4. On 2/1/2019 at 6:36 PM, martin swan said:

    The value of a violin relates to its degree of separation from a Stradivari (or a DG), nothing else.

    Being made in the same country as a Stradivari gets you higher up the list and makes up for all sorts of other shortcomings - terrible model, poor workmanship, inconsequential sound etc. 

    This profound injustice is the reason why so many great contemporary makers are pissed off most of the time ... 

    For every one of the really good Italian makers post-Stradivari you can find a Prague/English/Dutch/French/South German maker who consistently produces a similar quality of sound for a fraction of the market value. 

    WHat Martin describes has been the case for many centuries, but now modern makers from Italy don't have much of an advantage any more. American violins are now probably the most expensive, driven by soloists who used their instruments (e.g. Stern and Zygmutovicz).

    If one wants a 19th or 20th century violin there are some real beauties from German makers. Gärtner, Winterling are among my favourite 20th century makers. Investment wise it is Italian (Fagnola, Oddone, Bisiach ...).  They were also good, but not better than the best German makers of that time.

    Much of this market is now driven by Asian buyers. Unlikely that German violins will surge in value, maybe except for good authentic Kloz family violins.

    For good German instruments it is a buyer's market.


  5. https://simpk.de/arpeggione_790.html

    They say it is tuned E-A-d-g-h-e' as a guitar (h=b).

    Here a blog about it:

    http://arpeggione2009.blogspot.com/2009/08/arpeggione-stauffers-model.html

    And wikiedia also has the information about the tuning

    https://de.wikipedia.org/wiki/Arpeggione

    according to which the only old piece is that by Schubert but since a copy of an Arpeggione was made some more have been written for it (probably transcriptions).

    This is what it sounds like:

    Intonation isn't great.


  6. There is this article, www.jpschmidtviolins.com/Violin_Acoustics_2.pdf
    which I think is by Don Noon, our fellow maestronetter. It refers to this average table in the Strad for the 'key modes' of Stradivarius violins (I attached a screen shot of the spread sheet). I wonder whether anything along these lines exists for violas. What viola sound are we looking for? I know what I like, they must not be 'nasal', I like a strong C-string, I like it if they also have an edge in the upper strings (whatever this means). I have hardly every seen a viola at an auction that I liked.1836963595_Screenshot2018-12-30at21_47_17.thumb.png.35e3b8d56a508121fe25ef4373e2f302.png


  7. 18 hours ago, Don Noon said:

    That has been one of my pet peeves for a long time, and it's even worse than "signature modes", but just the mode frequencies that seem to get the vast majority of the attention.  I grant that the frequencies matter, but the amplitudes have a huge impact on the tone, and I can't recall any substantial work on how to control that aspect.

    I think it's pointless to try to look at individual modes in the higher ranges, but it is definitely a critical part of tone.  You don't have to work with names, but consider them to be sheep that might be herded in certain directions.

    I am trying to get the higher frequencies - they depend a lot on the environment, one almost needs a sound isolated room - which I do not have. Any laptop fan in the background will add a signature. Higher frequencies from from frequency modulating power supplies (dimmable LEDs etc) all add to that sound spectrum. 

    I work a lot with frequency analysis in science (I do something called NMR) and we would not accept a signal that does not have a signal to noise ratio of around 5 and is clearly reproducible.


  8. 11 hours ago, Don Noon said:

    For the first one, it is fairly clear to me:  231= A0,  321=CBR,  374/385=B1-, and 453=B1+.  Although we commonly just talk about these modes as if they are the only things there, quite often there are bumps and blips around them that can muddy the picture.  I wouldn't worry about trying to identify all the other higher peaks, as they vary a lot from instrument to instrument.

    For the second one, 210=A0, and 342=B1-, or perhaps a combination of B1- and the CBR.  The B1+ is surprisingly weak, but I"m sure it's there in the 400 - 440 range.

    FWIW, this is my VSA tone award winning viola (40 cm), analyzed with impact and bowed semitone scale.  The A0 and B modes are rather obvious, although I expect the bowed result shows a combination of B1- and CBR.  In my  experience, the CBR shows up much more strongly under bowing than it does for impact.  The bowed scale is also shown at lower resolution, to avoid the granularity of the single notes.

    11032440_Viola29.jpg.a1f76082b8376c80e523dfb841c4586b.jpg

     

    I agree with other posters that above 1400 Hz is definitely not "noise", although it is so chaotic you'd be tempted to ignore it.  Trying to analyze it to determine what it sounds like, or if it's good or bad, is a pretty impossible task... but the same thing can be said about any part of the response spectrum. 

    About the only thing you might be able to tell from the first two instruments is that the second one has lower resonances, and more power down low, so is likely to have a deeper sound.  You could probably say the same thing by just looking at the size difference.  Good or bad is far more difficult to determine, likely involves a lot of what is going on at the higher frequencies, and in the end is personal anyway.  About the only thing I can say is that huge gaps in the response are probably not a good thing, as well as excessively high peaks.  But then, trying to figure out what to DO about it is another impossible task.

     

    Thanks for this detailed response.


  9. Usually for violins only frequencies below 600Hz seem to be considered for A0, B0, B1, B1+

    http://www.catgutacoustical.org/research/articles/modetune/modechrt.html

    Schleske looks into the noise at higher frequencies but then one needs a more dampening window function. He also reads a lot out of some noise:

    http://www.schleske.de/en/research/introduction-violin-acoustics/sound-analysis.html

    One should average these signals, this is what we do in my field, NMR spectroscopy. We ust average equal signals until S/N is stronger. The type of frequency analysis is similar (except that you can't get a complex signal, i.e. two orthogonal signals, from a violin).

    Schleske also plots the x-axis chromatically, which I assume means log2 scale, as any double frequency is an octave. Audacity can't do this, but I can use matlab if I can figure out how to fft a signal that is not complex (i.e. of two rectangular channels). Maybe a HIlbert transform and then a power calculation?

    All this has been figured out before but is not well dcumented anywhere. At least I can't find it.

    My fundamental question is which resonances should be strongest for a good sounding viola.

     

     


  10. 2 hours ago, martin swan said:

    If it was a Testore, I don't think anyone capable of identifying it would say so here.

    If it's not a Testore, those people capable of identifying it will be happy to tell you so.

    It's not a Testore. 

    Are you any the wiser? 

    :lol:

    What does this tell us about you Martin? This means you might be able to identify it as it is not, but as it is not you are also happy to say so. And it is easier to identify it as not being a Testore than otherwise? B)


  11. I am trying to understand some frequency analysis of instruments, and wonder whether some of the experts here could give me some hints. Number 1 is a spectrum generated using Audacity with strings muted, by knocking on the bridge. Major frequencies are:862200803_Screenshot2018-12-23at13_34_53.thumb.png.c45e48df2873196435bacfb630adb388.png

    231Hz – largest/ widest peak overall

    Shoulders at 203 and 259Hz

    321 Hz
    374/385Hz
    453Hz – as large at 231Hz – about 2*231Hz
    489Hz
    534Hz (with shoulder to the left)

    566Hz - 591Hz - 636Hz - 665Hz - 713Hz - 781Hz - 817Hz - 873Hz - 945Hz - 977Hz

    Could someone help me assign what is what? This is a 402 body length viola, nicely resonant, very good C string, well balanced sound with an interesting edge to it.

     

    Here another instrument:

    1429988021_Screenshot2018-12-23at13_48_51.thumb.png.032e4e2b8c9e91eb28e127d92a8e6da5.png

    210Hz
    Shoulder at 245Hz

    342Hz

    417Hz/447HZ 480Hz
    592Hz - 567Hz - 594Hz - 636Hz - 661Hz - 714Hz - 781Hz - 821/ 851/ 867Hz - 941Hz

    This is a 41.6cm body length viola, very strong dark sound, extremely resonant on the C string, very large powerful sound. The better of the two, but the first one is also very new.

    I am trying to learn and hope some of you have the patience to look at this:
    What is B1, B1+, what are the other frequencies? Which sould would you predict from this analysis? Can provide a sound sample should someone be interested.

    I can later add some simpler Chinese instrument.

     

     

     


  12. On 12/21/2018 at 12:50 PM, martin swan said:

    JB Colin is a Laberte trade name drummed up to cash in on the success of Collin-Mézin. Violins with this label are very typical Mirecourt productions - here is a nice clean one https://bridgewoodandneitzert.london/product/violin-j-b-colin-mirecourt-1906/

    If we study the pegbox, scroll (in particular the pegbox cheeks and the fingerboard platform), corners, arching, varnish treatment, purfling, corners etc etc there really isn't much in common. 

    I agree that this is not a JB Collin, the varnish is completly different, and the underground untreated (dirty borwn where the wood comes through). But the fingerboard of the Bridgewood and Neitzert violin is also untypical as Mirecourt makers always rounded the corners of the fingerboard.


  13. On 12/21/2018 at 10:52 AM, martin swan said:

    Yes there were a few makers in Berlin. Do you think this cello relates to any of them?

    It's very hard for me to see how the Moeckels relate to Michael Doetsch - how are they part of a "school"?

    There were just some makers over the years. I also think you can't call it Berliner School. But I know at least one luthier in that area who has an interest in Berliner Geigenbauer. It is a little like the Scottish makers ...