Andreas Preuss

  • Content Count

  • Joined

  • Last visited

Everything posted by Andreas Preuss

  1. Now I know Sagmir Sonstwas, Geigen und Lauterzeug Macher, in Mitimwahn an der Irrsinn.
  2. Wasn't there a Sebastian Schelle somewhere? However, no idea if this fits.
  3. Thinking of German abbreviations with SS all sorts of things come to mind and some vulgar words made me laugh hard...
  4. Couldn't agree more. This is the very reason why my rule number one for changeing the design was: 'If a violinist steps out on the stage people in the audience in the first row should not be able to notice a difference.' My 'hero' in the field of successful form inventions is Hiroshi Iizuta who created his own fabulous viola model which got accepted by quite a number of viola players.
  5. Actually, yes this sounds about right for the recurve of the cross arching at the C bouts. Though we could go into a lengthy discussion if bending the wood wasn't the reason for curtate cycloid curves in the classical archings, which have a much wider radius there than modern violins. Anyway, what I see in most bending techniques is a sort of instant bending. I am inclined to think that a very slow bending (something which might take a whole day or even more) is less likely to fail even for a structure like a violin arch with curves and recurves.
  6. That's exactly what I want try to find out. And therefore there are two options: you start with a normal violin and thin it down in certain areas to find out any differences or you go the other way and make it too light and eventually too thin and flimsy and see where the addition of mass (or rather stiffness) makes an audible difference. It's in the end like the 'gluey' experiment Sam Zygmontovitch has done before. I don't see mass as a 'problem'. When I started this project it was anyway only my intention to play around with the goal of light weight and see what is coming up. However, now that I made this violin sound already pretty good, I am thinking also about a sound calibration system with small weights and would assume a rather light violin is more sensitive for doing this. Violin Restoration has added so many techniques to our repertoire and why not use it to make new instruments in combination with new materials. For the design, we should keep in mind that classical design patterns of Stradivari and Guarneei were made for music which didn't go beyond 5th position (not quite sure) but certainly did not use very high positions. I find it a sort of strange that this is accepted just with the argument 'there can't be any improvement.' I am saying 'yes there can be a better design, if we manouever cautiously to keep the balance between aesthetical appearance and acoustical necessities. I can only say that so far all violinists who thouched the super light violin liked the dropping shoulder and that the body feels short and handy. (The outline is diagonally in that direction 4mm shorter making it 347mm, that's almost 10mm less than a Strad pg model) Lets see...
  7. Hmmm, the pyramids and some violins share the same fate of man-made mysteries.
  8. I think this is open for test and trial. I would see bare gut strings played with a light bow as the key element for 'baroquish sound' If you are playing in a group, I would first try to change strings and bow, leave the modern bridge and see (or rather hear) if you can blend in with the other players. That's certainly not a solution if other members of the group are 'baroque puritans' and wouldn't allow such an instrument.
  9. I hate revolutions! Fortunately a Dutch rescue team saved the scattered pieces of the recordings and videos and is now rebuilding the baroque sound.
  10. On a general scheme it looks like this: When first finished the super light violin it was 317g, sound extremely woofy and basically unplayable. First change to improve sound: reducing weight of the back from the outside: No major changes weight around 295g. Second change: setting extremely heavy fernambuko neck. Weight c. 327g. No major improvements. Third change: Back to normal sized linings on the topside. Can't remember exactly the weight but something like 2-3G more. (At the same time some of the vertical rib bracings came off and I didn't put them back) First major sound improvement. Still a boxy sound but playable. Fourth change: Doubling the linings. The first change which went away from 'normal' violin making practices. Sound improved to almost normal. Weight at c. 332g. Fifth change: going back to a lightweight neck to reduce weight. No sound improvement expected. Weight down to c. 300g. 6th change: installing the Bayon bar adding 2g. No real improvement. More a shift of sound to more 'roundness'. 7th change: installing the cross bar. For what reason ever no measurable weight change. Boxiness somehow completely gone. Sound still on the dark side but with more grit (overtones). Summary: all significant changes stiffened the cross grain direction of the top. If the violin body is too loose in that direction it results in an unfocused boxy and woofy sound. At the same time this seems to prevent a good overtone range, but seems not to be entirely responsible for the optimal distribution of overtones. Right now there are two things I have in mind: correct the thickness of the back. There is a good chance that by thinning it down from the outside I went too far in the c bout region. So I would glue some patches there. Secondly make a bent top. This is more on the scheme same stiffness with less weight. Right now the top is 67g and it is even with a carved plate possible to get down to 60g (with BB). So maybe a bent plate can come down to 55g. Besides that there are a few changes playing around with some features: x shaped bass bar (I call it the spider bass bar) and adding a second cross bar below the ff. For both I expect however no dramatic changes for sound. I am not a motorcycle fan but maybe in the history of motorcycle engineering the weight of the flywheel changed by accelerating its rotation speed? In the end I can't abandon necessary structural elements on the violin neither but recalibrate the entire body for the same sound functionality. To take the example of the motorcycle I suppose that a higher flywheel rotation results in different driving properties. (Faster acceleration?) Addition: Being now down at 302g and having a violin of a functional sound it is the question if really 70g of additional mass is needed to make it sound really good. I guess not. What would be your guess?
  11. Ups, didn't write here what I changed. I made a raise pitch and put a new bridge, so it is a sort of reversible if I really wanted to. But somehow I am too lazy to do that just for one graph. Actually, I think I figured out what happened. I didn't plug in the mic properly So the computer switched automatically to the built-in mic resulting in those changes.
  12. Hi Jay, I am glad that this serves as inspiration for other makers. Initially my plan was really to beat the weight of carbon instruments telling myself, 'If I am a really capable craftsman, I can beat this.' My current result shows that in principle it is possible, though this is not some sort of top notch sound machine. Weight, as I was warned at the beginning from some knowledgeable MNetters, is not everything. Therefore I slightly changed the path for this violin from 'super light' to 'new concept'. Before I was trying to reduce weight no matter how, now I am still looking at the weight, but if I find that it is benficial to add mass somewhere for the improvement of sound I will do it. Concerning the braces, I think they are a necessary element when weight is minimized on the ribs. There are other concepts I am reviewing now. Maybe a thinner top (too thin in a traditional sense) can be counterbalanced by a new type of bass bar. In the end building this violin was the best teacher in violin acoustics I ever had. It is a highly recommended 'etude' for anyone who is interested in violin sound production, overtones, bow response etc. etc. PS. I still would be very curious to know to which weight Joe Curtin came down with his super light violin.
  13. Thanks, very helpful comments. I can't remember that I made the recordings in a totally different setup. I place the mic always in the same spot in the same direction and stand in the same spot playing the instrument. There must be something else wrong.
  14. Did you ever consider to attack the problem from the other end? There are some pretty descent sounding 3/4 violins around. Otherwise a skilled luthier can mitigate the problem pretty easily on your instrument by shortening the stop length. This doesn't even require an expensive neck graft or neck reset. I would shorten the fingerboard at the top nut 2mm and move the bridge 3mm up. This makes the bridge slightly displaced but not so much to be completely out of balance. 5mm less is a lot for hands of your size.
  15. Again a question to the scientists on this forum. I was just playing around with the audacity software and looking at graphs at different resolution. The two graphs are the latest development on the new concept violin. Left after and right before the latest change. Resolution is set at the lowest level of 128 what does the maximum sound level indicate? Is -35dB louder than -17dB? Does the small plateau between 5000Hz and 7000Hz have any significance? When I look at the same graph in high resolution it looks like this. (After the changes on the left before on the right) Most notable here is the difference of the integral volume (marked with red circles) Wouldn't this mean that the measured sound volume is less? Or is all this caused only by uncalibrated measuring setup?
  16. Latest small but importanat change. I made a raise pitch to get the bridge back to more normal height. The result was a clear improvement in the clarity all over. The previous boxiness is not an issue any more but this might be because of the cross bar installed inside. One slightly 'negative' effect I noticed is that on a light bowing the sound eventually collapses on some notes. But on the other hand trying to make the sound collapse with a very heavy bowing wasn’t possible for me. (Though I know some players who might be successful in doing that.) The bridge was recycled from another violin by refitting the feet. Because it had one ear broken off I decided to make a quick modern design. At the same time I thinned it down the bare neccessary minimum thickness of 3.5mm. The weight of the new bridge is only 1.6g. The new string angle is 157.5 degrees. Comparing the new sound graph (NCV42) with the previous one, there is especially an increase in higher frequencies which seems to be responsible for the improvement in clarity. This is just what Dunnwald and Buen have shown in their research. Thinking about further improvements I have to be very careful now because I might risk to destroy the result. One thing which can be made quickly without damage is to insert a second cross bar below the ff. I might try as well to find 'fat spots' on the top trying to reduce the weight another 5% (3-4g).Right now it is with the heavy Bayon bass bar 67g. Another reversible change would be to try a new bass bar. If the bending of the top turns out to be successful I will definitely try it with a bent top which should be theoretically lighter than a carved top. One thing I am not quite sure about is what will happen when I lower the ribs from this point. Right now the ribs are only 29mm and at the top block 28.
  17. Usually you can smoothen out everything with a very sharp scraper to finish the woodwork. Maybe you are scraping in the wrong direction? For a flamed surface vertical to the flames should take all bumps out. However, my personal take on that is that all machine instruments from factories have a super smooth surface similar to car body. For handmade instruments I find it by far more desirable to have surface texture which can't be done in a factory style working. If you are really thinking of fillers I would suggest to apply an uncolored (or slightly colored) ground varnish. this will not erase the effect but smoothen it.
  18. Hi Anders thank you for forwarding this link. Now finally I had time to read it. While it is interesting information there are a few thoughts on this test. The bending of the samples is compared to an arching pretty extreme. The paper is focusing small samples which are more or less like a short beam. I understand this as trying to simplify a model for better understanding. For bending a plate however we deal with a surface. The bending was done directly when the samples were exposed to steam or ammonia enviroment which means that basically no time was allowed for the samples to soak with ammonia or with steam (water) Most research is done for industrial use. This means they are looking for fast methods which mustn't be necessarily the best. If you take the arch of a violin as single beams aligned to each other you have nowhere such a curvature. After having bent top plates in an approach similar to Michetschlagers method, I see the biggest problem in the concave arching merging into a convex arching all around the plate. Therefore I have a bending process in mind which goes rather slow while the best enviroment to keep wood flexible is maintained. While in a steam chamber at 120-130Celsius seems to be ideal. Actually one of the important points seems to that the wood never cools down. Moist heat keeps the wood flexible. Though different from what I want to do I found this video about bending boat planks quite interesting.
  19. Rorschach test for violinists.
  20. I think the argument of loud sound isn't the only one here. I think a four stringed unfretted instrument could be used in a more versatile way especially for the soprano instruments (violin versus soprano viola da gamba) I don't think bent plates were the reason for a small sound. I think it is rather the entire construction with a flat back, C holes and a heavier string load of 6 or 7 strings on a body with high ribs. If it works, I'd be very happy to put the result in a blind test comparison. And if it works, maybe I won't think any more about buying a CNC.
  21. Kind of surprised to hear this statement from you, because yo are definitely not a traditionalist. Anyway for this kind of experiment I am not looking back on what old Italians have done. Its more the spirit of curiousity what we can do with wood. For the physics of such plates it is really the question if they get stiffer. In theory they should. However the alkali treatment an the heat bending process might take stiffness away. Are we not making chairs? Sometimes I don't know. We might be able to learn something from there. It's not so easy to make a chair which holds for a long time without that joints getting loose from the weight. (Or children who can't sit still and are tipping them in all sort of dangerous directions.)
  22. Still missing on the list perfect or near perfect symmetry using absolute measurements (instead of relative measurements.
  23. Hi Evan, I want to bend the top plate. So right now the 'formula' I have in mind is 1. Prolonged soaking of the boards in an alkaline solution. 2. Heating the boards in the solution. 3. Bending to an arch shaped form. Actually I want to sandwich it in between a positive and negative cast. 4. Slow drying (might take a few month) 5. The rest is trial and error. How thin do I need to make the plates, how long do I have to soak them, how long do I have to cook them. I have seen your thread about bending the back. Interesting method. You are pressing from two directions, horizontally and vertically, right?
  24. The wedge and hammer method looks a bit too brute to me. This is only neccessary if the planks for bending are too thick. No wonder that the wood got buckled cells. My assumption is that if you get as close as possible to the desired final thicknesses you can bend wood with no buckled cells inside. I see some alkali solutions as a helper to bend wood as natural as possible. Or if I don't need them, I wouldn't use them. If this is what you meant with 'naturally bent wood.