uguntde

Members
  • Content Count

    328
  • Joined

  • Last visited

Posts posted by uguntde


  1. 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)


  2. 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.

     

     

     


  3. 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.


  4. 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 ...


  5. On 12/18/2018 at 5:29 PM, Don Noon said:

    A wolf is associated with a strong resonance of some kind, usually a major body resonance (B modes)... which are strong sound producers.  The E note is also not a normal location for the major body resonances (except as noted below), so I'd look for something vibrating that does not radiate sound, and the first thing I'd check would be the tailpiece... removing the movable mute, adding weights in various spots, etc. to see if anything changes.

    If that's not it, then there IS a resonance that could be in that range, the CBR, which is not a good sound producer.  Before tearing into the instrument to change the bass bar, or gluing on something, I mess around with chinrest weights and positions, which can have an effect.

    One oddity here is that the wolf is only on the G string, and not the identical note on the D string.  A resonance of the types above (or any other type I can think of) would likely be stronger on the G string, but should still be there on the D string.  

    You were spot-on with "so I'd look for something vibrating that does not radiate sound". This viola has a very thin fingerboard, made in Degani's style, hollow underneath. If I stick a piece of lead underneath with double sided tape the wolf is completely gone.

    How did you come to this guess? Because B modes can'e be around E or F?


  6. Knitl should have a signature on the back. I will have another close look whether there is anything faded, but I think not, I would have seen this. The pins, in particular the 3 in the button, could be later - although, why would anyone add 3 pins there??? Reminds me of Monty Python's Michelangelo in which he paints the Last SUpper with 3 Christs.


  7. I have a really good sounding viola with an annoying wolf on the E on the G-string. It doesn't rattle but the note sounds sick, much weaker. It is not there on the same note on the D-string, there the E is crystal clear. But I have to play many passages in 1st position that work better in 3rd.

    I know how to eliminate it. A little pair of magnets does the job - see the picture. I shifted it arond to find the optimal position. Further down it makes a worse wolf on F, but in this position all is gone.

    I do not like this magnet on the instrument and wonder what solution you would suggests. One could stick a piece of wood on the front through the f-hole, one could also fit a slightly higher bass bar.

     

    20181218_120424.jpg


  8. Here the dimensions, hard to measure over the high arch:

    Length of back over arch: 358mm

    Width:     upper bouts: 166mm
                     lower bouts: 204mm
                     mid C bouts: 114mm

    Rib heights: neck: 31-32mm, bottom 32-33mm, mid C bouts 31mm, corners (all 4) 32mm


  9. I will post dimensions when I have access to the instrument again later this week as I am currently travelling.

    I always wondered about the locating pins, the shape of the f holes, the one piece front and slab back. Also the square blocks, not the round half moon shape typical for Kloz instruments. More like what you see in later French violins.

     


  10. 3 hours ago, Davide Sora said:
    I share your perplexity, I have enough experience to know that the same varnish applied differently, with different dilutions, different thicknesses of the layers, different drying times between layers and all others possible variables in the application process can give very different results, from the perfect varnish to the worst aligatoring.
    So it is difficult to make absolute claims based only on a couple of cases, even if reported by reliable and experienced people.
     
    Having said that, also in my opinion it is not a good idea to follow Michelman's book to the letter, but the basic ideas are not to be thrown away.
    I also suspect that the causes of the bad alligatoring  can be found otherwise, for example if the impregnation with oil suggested by the book was used as a ground, it could be this to have caused problems and not the varnish itself, or insufficient drying time between layers or a too thick layer or......or.....or......:rolleyes: 

    What I wonder about Michelman is how this varnish dries, as the rosinate and drying oil are not fused. If you cook them together you get an extremely well drying varnish, I get a drying time of 3h in UVA.


  11. I recently dissolved rosin in alkaline solution and precipitate with Fe SO4. Air oxidises the Fe2+ quickly to Fe3+ which so redbrown. I added a little rosin and cook this briefly together, then added an equal amount of linseed oil and heated this for one hour. I get a relatively hard sticky substance that dissolves in turpentine.

    20181212_115937.jpg


  12. Let me ask this way. If I took it to H Köstler and asked for an expertise he would probably come up with something. If he assiged a name to it, would you believe him? If not, I'll call it Kevin Kloz from now on.


  13. 6 hours ago, Blank face said:

    Nice old Mittenwald, but why has it necessarily to be a "Kloz of some kind" and not a Sailer, Hornstainer, Karrner or one of the hundred other good makers?

    That's my question. Can we assign a name to it?


  14. 2 hours ago, JohnCockburn said:

    i think i see one.

    Yes there is a very well repaired crack in the back, left bottom, studded inside. Not close to the sound post. No soundpost patch on the front which is amazing for a fiddle this age.