Jump to content
Maestronet Forums

Torbjörn Zethelius

  • Posts

  • Joined

  • Last visited

  • Days Won


Everything posted by Torbjörn Zethelius

  1. Andreas, in addition to the information given in my article Arching the divide: I Segreti di Buttegha. The discussion about calculation of the focal axis is complex and I've heard from a Catalan friend, also a violin maker, that Dipper's translation is problematic. As an example, there's no mentioning of arching templates in the original Segreti text. We will be working on the original Italian/Catalan text which is included in the book, to try to work out our own interpretation. When talking about the measure of the internal archings, it says: "this is true for both the belly and back". I interpret this as meaning that the internal depth of the arch is the same for both the belly and the back. The Dizionario is interesting because it clearly explains how violins were made before the French method of copying took over. As a result, because of its clarity, it also illuminates how to understand the other texts. In none of the older texts there's any mentioning of tapping the plates to optimise the sound. In my view it is a practice started by Savart that the old makers never did.
  2. Both the 1716 Medici violin and 1690 Medici viola have breast patches in the belly.
  3. I very rarely bite visitors. I'll see you in September then.
  4. Peter, I'm curious of your violins. If you're ever in Stockholm, show me a violin (or two) and I'll tell you what I think. We can also ask an experienced violinist friend to play it. Always good to meet in real life.
  5. I don't see it that way. How can you carve an inside back arch to look like the outside of the belly? It doesn't make sense to me.
  6. My article 'Arching the divide' addresses this common concept among Italian makers. If we are looking for a concept, then we should also expect to re-evaluate our own conceptual ideas about how violins are made.
  7. It depends on the wood and the thicknesses, and possibly the climate. It's probably impossible to predict how much.
  8. The constant tension from the strings pushes the extreme areas of the belly upward and makes the belly arch flatter.
  9. No, it will not sink in, but the upper and lower bout areas will almost certainly rise, as David Burgess have explained. This will result in a flatter looking arch. Like this. That's why Del Gesus with their thicker graduations hold their shape better.
  10. Here's an arch of mine. The back arch is skewed in the photo. The lens is even with the belly's edge. I expect the belly's long arch to change from the string tension. As you can see it's not a catenary curve. I think that some might have the false impression that the long arch should be a catenary due to my use of a chain. But it doesn't have to be that way. I should add that it's up to the makers' choice how much to dig away in the extreme portions of the belly, near the end blocks. For this I have chosen to stay fairly close to Sacconi's illustration no 68 on page 72 which shows the internal long arch. It's my interpretation of Cremonese arches as they were originally. Due to the difference in thickness, the back arch is more curved than the belly. Now you can judge.
  11. Joe, you said it better than I ever could. It was my observation as well. Any substance in the wood is more likely to harm the sound rather than help it. IMO
  12. As the OP said, it penetrates a lot. If any oil has been found in Strads, it would be by accident, not by design. IMO
  13. I would seal the wood very carefully before putting any oil on it.
  14. Sound is of course no. 1 when choosing wood. A good maker can make a decent sounding instrument of almost any kind of wood. But violin making is a very traditional craft so we stick to the traditional wood.
  15. That's recommended. Yes, he is, as far as I know.
  16. Yes, you can do that. It won't help though. Violin sound is still a mystery.
  17. I don't need a rational explanation. Well, I wouldn't call it a secret, since I've explained everything that I do.
  18. I guess you'll have to find out for yourself.
  19. Yes, you should definitely take internal reflections into account.
  20. Is this from Euro Peluzzi's 1978 publication Tecnica Costruttiva Degli Antichi Liutai Italiani, or is it your own? How might the ancient philosophers have thought about it? You can't apply modern science to ancient techniques. Better to apply ancient philosophy. David, Dizionario delle Arti e de Mestieri, by Francesco Griselini and Marco Fassadoni, published in Venice 1770 The principal point for the goodness of the instrument is to find good, old and sonorous spruce for the belly: the best is from Tyrol. The cavity shapes given to this belly in a vault shape more or less high, the diverse thicknesses to be observed, the way that the bassbar is placed inside, to the side of the cordone, which is the thickest string of the violin, the height of the ribs, and finally the excavating of the back which has to correspond perfectly to that of the belly; all this together with the true way of positioning the two holes in the shape of S which are carved in the violin belly, the placement of the soundpost and the bridge, contribute in an essential way to the goodness of the instrument. Translation Luca Primon. Cozio di Salabue mentions the same thing. My article explains that also Antonio Stradivari may have followed the same principle. The key to understand it is twofold: that the inside is the focus, and David Burgess' explanation of the bulging of the long arch over time. Or you can ignore it and do your own thing. The question remains: how do you prevent the long arch from creep?
  21. The old texts that I've read says to make the top and back the same. Time will do the rest.
  22. The Messie Strad, Medici 1716 violin and 1690 Medici viola and the Lady Blunt. The best preserved Strads all have curved arches.
  23. My interpretation of the difference between Strad and del Gesu long arches is that Strad made his bellies thinner while del Gesu has thick bellies that retains their shape better. As David Burgess pointed out though, all bellies change over time.
  24. A short explanation wouldn't do any good. I've explained my method in detail in my article. This thread is about Stradivari's secret, not mine, so I won't waste time on it here. PM me if you're interested in reading it.
  • Create New...