Tuesday, December 11, 2012

Variation on a Theme - A New Voboam

I just finished a new baroque guitar after the 1690 Jean Voboam, E.2087 Musée de la musique, Paris. Since I published four posts earlier this year ( Feb 8, 27 and Mar 6, 15) on a similar guitar I will only describe the variations that I made on this one.

I usually sculp the edges of my pegheads with one of the characteristic Voboam designs, veneer them in ebony and leave it at that. But with all of the repair work that I have had to do this year I have been feeling frustrated and depressed. I decided that I needed to make something elaborate and challenging.

René, Alexandre and Jean Voboam often decorated the pegheads of their elaborate guitars with parallel lines of ivory and ebony chevrons mounted by a panel inscribed with their name, place and date. The peghead photo at left is of the Jean Voboam guitar, E. 2087 that I model. I used the same general lay-out as Jean but I reversed the sequence of the ivory and ebony chevrons and omitted the border around the inscribed panel. Various combinations of these elements are found on other Voboam guitars. I also used holly, a fine textured white wood in place of ivory.  I cut the  straight letters with micro chisels and the curved ones with gouges after having made many practice samples.

Original bridges and their flourishes often have not survived. This photo of Royal College of Music No. 32 London, attributed to René Voboam, shows a replacement bridge with original flourishes. I liked the ornate delicacy of this example and decided to model it.

I drew an approproximate likeness and re-sized it to fit my guitar. I glued the pattern on a thin plate of ebony .8mm thick. Since there are many delicate elements in this design, I backed the ebony plate with a layer of paper for added security. Usually, I glue two plates of ebony together sandwiching a slip of paper between and then saw two flourishes together, carefully separating them when finished. In this way I am assured that the two flourishes will be symmetrical. But this time I sawed out each flourish separately and purposely altered the design slightly. Adding a top plate of holly and ebony parallelograms completed the design.

Inside, I made a significant change. In my post from February 8 I commented on current research that suggests that later additions made to the barring of the back and belly and the re-inforcements of the side ribs of Voboam guitars obscures the makers' original intent and affects the sound of the guitars if these additions are copied by modern makers.

Here I am concerned with the barring of the back. The back in this photo of the Smithsonian Voboam, MI*65.0591 taken by Thomas Georgi has no braces and the continuous re-inforcement strips over the joints suggest that it never did. 

When I examined E. 2087 in 2008 I was curious about the location of the braces on the back and by listening to tap tones I decided there was a single bar located across the lower bout. I have ignored this information but I this time I changed my mind. Making the back a little over 3mm thick I included a single bar and a number of small short tabs. The latter secured and maintained the back's outline.

The treble side is left.

I strung the guitar and tested it before I applied any finish. It responded with the usual silvery warmth, quickness and volume level that I expect, but with a degree of responsiveness that I found disturbing. I attributed this to the freely vibrating back. I wanted to retain the quality of sound that I could hear  the back was contributing, but some control needed to be added. I believe that musical instruments, at least lutes and guitars, are counter-intuitive. I lifted the belly and inserted a thin moderating bar behind the bridge as shown in the diagram. It is 70mm long, 3.8mm thick and 4.3mm high. It is located 58mm from the rear of the belly. The bridge is 104mm from the rear. It did the trick.

All photos by the author unless otherwise noted.


  1. Michael, I'm curious about the soundboard thicknesses for baroque guitars, especially in the french and italian tradition. What is your experience? And how many extant instruments we have measured (with original sounboards of course), I have the feeling that most drawings come without the soundb. thickness. Thank you for the picture of the Voboam soundboard that you posted but it is to small to read the numbers representing thickness.

  2. Paul, there isn't much information available. Most museum instruments are closed so, in my experience, there is no way to measure the belly thickness. Also, conservators and restorers seldom record these measurements. Here's what I have:
    Rene Voboam 1641 Ashmolean 2.5mm @edge. S. Barber drawing
    Voboam RCM 32 less than 2.0mm behind bridge. Schreiner
    Jean Voboam 1690 E.2087 Paris 1.7mm @edge. Schreiner
    Anonymous Guild of Amer. Luthiers plan 2.5-2.3
    Italian guitars generally have only two bars, one of each side of the rose and may have thicker tops. Voboam barring is described in my older posts. The thicknesses I used in this guitar, in thousandths of an inch, are: 85/1000 on treble side of bridge, 80 on the bass side, 78 around the treble contour and 76 and less around the bass. The upper half of the belly is near 90/1000.

  3. Thank you Michael, very informative.. Regarding the italian instruments, I have a Sellas drawing that gives soundboard thickness of about 2.2-2.4mm near the bridge and a bit thicker at edge of soundboard (I think 2.6-2.7mm I have to check it). But this guitar has a third bar above the bridge.

  4. Thanks for your comment, Paul. Which Sellas is this? I forget that I have plan for a large Sellas in Edinburgh that I have mis-placed. Also I forgot to mention the Stradivarius in the Ashmolean. Barber measured its belly at 1.5mm with only a diagonal below the rose.

  5. It's 1624. Sellas from Germanisches Nationalmuseum Nurnberg (MIR860). This is very important information about Stradivarious because it's very different from anything I heard till now, is it 1.5mm just near the bridge or also at the edges? Really lute-like thickness.
    Since we are talking about drawings, I have been trying to buy plans for some time now from Cite de la musique but they stoped selling the plans (because some problems within the museum). Is there a chance that you have some of the drawings, I'm looking for Jacob Stadler (previously anonymous 17.century on their web) E.30 guitar plans. If you have maybe we could swap plans, I have some.

  6. I wasn't aware of this guitar. I looked it up on MIMO. It certainly is interesting. The thickness measurement for the Ashmolean Strad is only given at the side of the drawing suggesting that the entire top is 1.5mm. I don't have either the Stadler or E.30 drawing.

  7. Thank you for the information.. and for the Checchucchi drawing that you made, it is nice to see someone is sharing his work to help other fellow luthiers.

  8. Paul, did you get the Stadler drawing?

  9. I did found one Stadler drawing, I'm not sure if it is original from Paris museum, but looks accurate.

  10. Hi Paul,
    Do you know about the database at http://homepages.ed.ac.uk/am/iwd.html#Guitars
    Four Voboam guitars are listed. The Ashmolean in Oxford has a 1641 Rene Voboam. The drawing is excellent and shows the construction of the through neck. It should be available at https://shop.ashmolean.org/index.php/prints/hill-drawings-instruments/40-guitar-by-rene-voboam.html
    The Royal College of Music, London also has an excellent drawing of Jean Voboam 1680, No. 32. The drawing should be available at

    1. Hi Michael,
      Thank you for the links, I am aware of the database, excellent resource. Ashmolean Voboam and Stradivarius were on my list to purchase a while ago, but I still don't have them. I can see these are excellent drawings. I have a Voboam drawing and vilhuela from Paris Museum.
      But the other plans from Paris (and Bruxelles) are very difficult to find, it seems most of them are not really for sale, despite being in the database. I was looking for baroque lutes and liuto attorbato etc. but many of these drawings are not available.