Roger Hill

N-rays may be the fundamental cause of some of the effects heard by audiophiles. Oded: I have an old LP of some live recordings of Caruso, live. Some of the tracks are from 1904. I doubt that there is any information on those original tapes above 3,000Hz. The tape hiss is awful. The music is delightful.

Yes I am biased, but note that I also gave a definition of what is an improvement to me, additional detail that I can hear (and point out to others who then hear the same thing). It is not better because I made it, but because I can hear additional details in a variety of CD's and LP's. The equipment has produced an SPL that excites those little hairs in my ears, which my brain processes and said "yes, that is better". Two out of three of those things involve some physical process, density variations in the air, movement of the micro hairs in my inner ears, etc. When there is something that has no identifiable and credible physical process to explain it, then I start suspecting snake oil. Which is, of course, bias to the true believers in some of these things. In the case of violins, my feeling is that musicians are probably not the best subjects to do the listening. I have several friends who are musicians who listen to plainly lousy audio systems. They marvel at mine, but stop being concerned with what they are listening to when at home. They listen to the music.......the first time I hear a different system I am listening to the sounds. There was a blind test some years ago that used Isaac Stern, Pinchas Zuckerman and A big name violin dealer, whose name I can't recall. They couldn't discern which were the new violins and which were the Strads. Another example from the past was that Stern played his Zygmuntowicz violin at a rehearsal of some chamber music with Yo-Yo Ma and Isthak Perlman and neither noticed that he was not playing his Guarneri. But I would bet that any would notice the difference if they were playing the violin. Perhaps the best ears for evaluating violins from 15' away would belong to (say) oboe players. There is clearly prejudice in blind tests of sound, error can come in. There is also such a thing as snake oil.

The point is, that in addition to the field of inquiry, there is a sub-market for selling snake oil to those who are so open-minded as to what may produce improvements that they will buy anything and be self-deluded into thinking they hear an improvement in something or another.

Not implying that at all. I certainly qualify as an audiophile, having had audio as a hobby for about 45 years. I have designed and built my own tube-type amplifiers and pre-amplifiers for years. They are better than anything else I have ever heard, which is a lot of hi-end equipment. I have designed and built transient-perfect three-way speaker systems. They are as good from 50-Hz up as anything I have ever heard, again a lot of high-dollar speakers. My fundamental criterion for audio improvement is that more the more detail audibly produced is greater fidelity to what was actually recorded. When I listen to various "tweaks" and nothing new comes out, then I say "I don't hear an improvement." Many audio "tweaks" simply don't pass the laugh test, the brilliant pebbles for example; The C-37 for example. Peter Belt even contends that he can improve the reproduction of sound by your equipment by having you place a phone call to him, for which he charges. Some people say it actually works. I won't be trying it. To think that a 1/1000" length of solder in a junction that is a few millionths to hundredths of a square inch in area is audible just doesn't seem in any way reasonable to one with a technical education. There is a very high level of foolishness among a significant fraction of the audio community, and that is what I was referring to. Edit: read this http://www.belt.demon.co.uk/product/odl/One_Drop_Liquid.html I rest my case

The things that "audiophiles" can hear are simply amazing: different solders, different amplifier signal wire compositions, coating coupling capacitors with that famous C-37 varnish, elevating speaker wires off the floor, coloring the edges of CD's with green ink, placing small jars of smooth stones on the speakers and around the room. I've even read of placing quarters around the room improves the sound reproduction. Any blind test should surely be done with "audiophiles" as judges, bound to get better, more accurate and meaningful results.

I think that the fundamental issue is the thought processes of Nick, Tony and Joe. How did they think of the arches and what did they try to implement based upon those thoughts. If they thought of the arches as perfectly separable one dimensional curves, so be it. Are we, who attempt to recreate their magic, to quibble at their lack of mathematical sophistication? All we care about are the results of the thought process, regardless of the lack or rigor.

I suspect that the technology used arose from that used to make graphite fishing rods. Fly rods are made using spiral wraps on a tapered form, layered with the spirals in opposite directions. Linear fibers along the exterior. I am sure the Chinese manufacturers make a lot more fishing rods than violin bows.

one of them is, kept under lock and key. Cozio pawned the gold ones and used the money to buy dope..........

Well, you certainly don't want the minimum to go through the lower eyes of the F holes, or even too close to them. Maybe those dope-smoking hippies had some other "insights" that I wouldn't think of at my advanced age.

I agree, John, where the inflection is placed is a big deal. How you lay out the hourglass is the "art" for the maker to decide. My guess is that the old masters simply did it by "TLAR", ie "that looks about right" for whatever they wanted to try with that particular violin. Perhaps they did use an actual CC to set the inset of the hourglass from the ribs. The inset of the hourglass in the center bouts would certainly be different from that in the upper and lower bouts. I checked four of my posters for the distance (in mm) from the plate edge to the minimum point for the lower, center and upper bouts. The results are interesting: del Gesu: Kochanski 1741 14,10,10 Lord Wilton 1742 7,6,6 Stradivari: Viotti 1709 7,4,6 Kruse 1721 7,5,8 I think what we draw from such arching/inflection differences is that the old guys were experimenting, just as we are. I have to wonder if del Gesu was going back to a Strad arching when he carved the Lord Wilton.

Hi John: This method is essentially what I suggested in the thread I started on Cremonese arching and the inhomogeneous catenary. The method of construction generally follows that laid out by Torbjörn. The arch shape is decided using the appropriate chain and a horizontal line on the wall the length of the distance between the end blocks. The high point is decided upon and that point marked on the chain (for most cases, this isn’t necessary for the back curve). The high point is located on the plate and drilled to a depth equal to the desired (exterior) height of the arch minus the maximum thickness of the finished (graduated) plate. The longitudinal arch is carved using the appropriate chain between the end-blocks as template. The interior cross arching is then carved using the plain chain as a template. The depth of the longitudinal arch at any point defines the cross arch catenary. Once the interior is carved, the arching is transferred to the exterior using the graduation punch set to the maximum desired thickness of the plate. The punch is set up with a support post having a rounded top. After the top shape has been carved and scraped down to the punch marks the plate will be of uniform thickness. The support post on the graduation punch is next replaced with one having a hollowed center to allow the convex top surface to fit securely and rigidly into the hollow as the punch forces the wood onto the post. The interior is then punched and scraped to the final graduation pattern. A couple of observations: the marks on the top of the cello in the picture given by MD are totally consistent with the above procedure, as are the inside punch marks on the Strad violin. The punch is used twice, first on the outside, then on the inside. Secondly, there is no need to use a drill with a special end-point to begin the carving of a plate. Guarneri may have used one simply to save time. Thirdly, it is much quicker to make a few chains than to make templates for every desired arching shape. The principal difference is, of course, I suggest that the longitudinal arch be defined with a catenary of an inhomogeneous chain to set the depths of the cross arches. At this point, I would suggest drilling holes of the appropriate depth just in front of the end block locations and using those two points to plus the high point hole to define the longitudinal catenary. Note also that if the heavier sections of the inhomogeneous chain end near the widest points of the upper and lower bouts, the catenary along the length will be virtually identical to the cross catenary, and the "bellows" effect naturally results along two perpendicular axes. One observation I have made in the cat scans of the various violins is that the plates always join the ribs with a horizontal section of the plate perpendicular to the ribs. Rounding the edge between your hourglass edge of the catenary and the horizontal section will necessarily produce the underside of a curve that approximates that which would result from a CC on top transferred to the bottom of the plate with the thicknessing punch. In my opinion, based soley on study, not experience with building violins, the inside first roughing is more consistent with evidence than anything else I have seen. edit: one of the most instructive things I have seen regarding edges and recurve is the CT animation at Terry Borman's site of a 1735 del Gesu (maybe the Plowden?) http://www.bormanviolins.com/CTResearch.asp

O.K, I won't argue with you then. I respect your knowledge greatly, but I do not see how the beautiful side to side symmetry of the cross arches in the upper and lower bouts would result in so many different violins of different arching, graduation, elastic properties, etc. You may call me "Thomas"

Don't have dogs on my bench, only on my couch :) . In any event, it is the bending moment due to the sound post/bridge force couple that creates the asymmetry. It would take two oppositely directed bending moments along the center line to produce a realistic hope that the beautiful symmetry of the violin top would result. GMM22: Here in Colorado water flows uphill to money but not to violin makers . See post 53 on page three if this thread http://www.maestronet.com/forum/index.php?...rching&st=0 Note also that due to the similarity of parabolas and catenaries, the three parabola model that John used for his calculations is virtually identical to the inhomogeneous catenary I proposed some time ago. In any event, three curves seem to be required to produce the long arch: Two different CC's plus an arc if you use the model Michael Darnton champions, three catenaries if you believe in an inside first approach, using catenaries for most of the cross arch with the inflection and recurve added at the edges to create a CC cross arch.

Regarding whether the top longitudinal arch may simply flatten over time to the shapes we see, I suppose some industrious mechanical engineer might be able to construct a pathological violin shaped plate that would do so, but I think the likely hood of being able to do so ranks right in there with water flowing uphill. The bridge pressure and sound post create a bending moment that tries to flex the south end of the violin up and the area north of the bridge down. The moment is applied at a point east of the longitudinal center line so that the arching is high on one side of the applied couple and lower on the other. The stiffness of the plate varies all over the plate. To think that all this could work together to produce the beautiful symmetry we observe just doesn't add up.

A musical airing of some Hill family dirty laundry. The violin work is outstanding...........

Hi Maestrolover: Most everyone on the west side of Colorado Springs (near the mountains and National Forest) deals with wildlife, and most people have the sense not to feed them. We did have a bear that had to be destroyed a couple of weeks ago because she had become accustomed to people, naturally one idiot was feeding her. Last year we had the U.S. Senior open at the Broadmoor hotel here. Play was briefly interrupted when momma bear and two cubs crossed the course during play...........a sensation on the TV coverage. My wife Vicki and I have backpacked all over Colorado and the sum total of wildlife we have seen in the wilderness areas is two deer, a porcupine and some marmots. On the other hand, here in our neighborhood we have rabbits, deer by the herd, an occasional elk, coyotes, bobcats, foxes, bears and (rarely) mountain lions, to which we accord a wide berth. Newcomers to the area quickly learn not to put their refuse out the night before pickup. The biggest problem the wildlife cause is expressed by the new sign with a picture that appears on the street lamp posts about every two weeks: "lost cat.....Fluffy, children heartbroken, big reward" I usually think to myself, "well folks, it's time to explain to the kids that Fluffy got 'et." Small pets out at night keep the hunting skills of the predators honed to a very dull edge........they really are easy pickings for the predators. Again, most folks here soon accept the notion that there is a certain responsibility we have to our pets to not let them be eaten! I wouldn't change it if I could, and certainly never worry about the wildlife harming anyone. However, my wife has shed many tears at what the deer have done to her gardens............we have learned to buy plants the deer won't eat. So no, we just don't worry about the bears and other wildlife. They spend most of their time in the common areas (which were too steep to be developed into lots) and don't get to see them very often. We simply enjoy them when we do see them.

We've seen this before, but I don't recall the thread. Michael Darnton was very negative about it. IIRC, he stated that he could see tangent circles very clearly, which the spirals are not. BTW, if you haven't been to the Francois Denis site recently, he has now posted a complete animation that works step-by-step through the entire process of laying out an Andrea Guarneri viola plan form. http://www.traitedelutherie.com/ EDIT: see comments by Michael Darnton in this thread: http://www.maestronet.com/forum/index.php?...9&hl=spiral

Took these on Saturday, eight days ago. Little fellow awakened from a long winters nap with a powerful hunger for some birdseed. Chased him away after I took a few pics. Life in the wilds of Colorado Springs, Population 600,000.

NewNewbie: John's picture combined with Torbjörn's observations are what led me to the method I proposed in the thread I started on Cremonese arching. What I proposed certainly had its detractors, primarily Michael Darnton on the other forum. The main objection was that the catenary shapes I proposed for both the long and cross arches do not match the inflections near the edges of the plates. With Oded's recent work, there is reason to rethink how closely the inflections (i.e. recurves near the edges) should match the CC. Fascinating work going on here.

Hi William: I am rather ignorant. Would you mind telling me what is the definition of impedance as you are using it. What is the analogue of voltage? What is the analogue of current? Thanks, Roger Hill

That is pretty convincing, Oded. Do you have any feelings as to whether it might also have been common to do some adjustment near the ff holes by scraping the inside? Special tools shouldn't be all that difficult to make.

Hi Oded: Suppose you have carved your plates to Curtate Cycloid outer shape. After applying your method, how much (typically, in your experience) are the resulting arches distorted from CC's? Is the distortion from CC's visible?

is there any need for UV to cure the varnish when applied as an emulsion?

Hi John: Would you mind posting some pics of the various plates and the sequence of their use? Would be very helpful to me in visualizing your system. Thanks,