Author: Jonas Lohse

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J. S. Thumhard 1816

On my workbench today: half a bass with a note reading “Johann Stephan Thumhard.” The handwritten date is barely legible. A bit of UV light helps me make it out and reveals what might be a “16.” This suggests the bass was made a year before his death.
The Thumharts (Dumbhart) were a large family of violin makers who lived and worked in Bavaria (Amberg, Straubing, Ingolstadt, Munich) during the 18th and 19th centuries. Lütgendorff writes about Johann Stephan Thumhard:

Thumhardt, Joh. Stephan — Straubing. *1749, † 26. Dezember 1817
According to the Straubing trade register, he established himself there in 1769 as a violin and string maker, married in 1773, and handed over his workshop and estate to his son Alois in 1817. He may have been a pupil of Buchstädter, whose work he imitated quite closely. His better violins display a characteristic narrow model with elongated scrolls and sound quite good; however, his brown-yellow or brown varnish has mostly lost its luster. His gravestone still stands in the St. Peter’s Cemetery in Straubing, and on it one reads: “He was esteemed by his fellow citizens, and posterity will still praise him for his works of art. R. J. P.” The twelve violins he allegedly made for a wealthy connoisseur and eccentric are considered his finest. For the first, he received one ducat, which seemed too little to him, yet he said nothing when he was immediately commissioned to make a second, even better one. The customer then paid two ducats for it and demanded an even better one, for which he paid three ducats, and so on up to twelve ducats. Because of their number—twelve—these violins are called “Apostle Violins”; one of them (from 1793) is still owned today by District Court Judge F. Ebner in Straubing. In the same collection is a viola from 1782; a viola from 1809 is owned by musician Schmid in Straubing. The church choir at St. Jakob there also owns two violins from 1814 and 1815, as well as a particularly beautiful bass (1815) by Stephan Th. His violins have already fetched quite good prices, and his basses even higher ones.

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Height-adjustable fingerboard

Height-adjustable double bass bridges are now widely used, and several bass makers have also experimented with adjustable necks. The goal here is to be able to adjust the string action (i.e., the distance between the strings and the fingerboard) in order to adapt the bass to varying humidity levels or different strings and playing requirements.

A customer recently brought me an interesting bass that had been fitted with a height-adjustable fingerboard (sic!) by the previous owner several decades ago. To achieve this, the fingerboard was screwed to the neck via a hinge beneath the nut. Beneath the fingerboard’s overhang, the angle of the fingerboard could be adjusted using a toggle lever. A stainless steel T-bar stabilized the neck, which would certainly have warped without the firmly glued fingerboard. Today, one would use a carbon insert here, but that material wasn’t available in the 1950s.

The whole design was very well executed from a craftsmanship standpoint—yet the customer still wanted it removed. Where the toggle clamp had been mounted on the neck block, I replaced the missing part of the top wood. The T-bar was not only screwed in but also glued—and could not be removed that easily. Milling it out was, of course, out of the question with stainless steel, as was applying significant force—so it stayed in place.

However, the bass is not entirely without adjustment options now: the bridge was fitted with Franz Moser’s height adjuster screws, as well as with a height-adjustable saddle.

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Plywood edge repair

On double basses, the protruding edges of the top and back sometimes break off or splinter. On laminated double basses, this often only affects the outer layers of plywood.

On some basses, however, the purfling is merely painted on — especially plywood basses, but also many old Bohemian basses have no inlaid purfling. In violin-making literature, inlaid purfling is said to have a protective effect: cracks that run from the edge to the center are virtually “stopped” by the purfling running perpendicular. But is this really the case?

The plywood bass shown here clearly shows how the missing (and already replaced) pieces extend exactly to the inlaid purfling. Continuous cracks, which the purfling could stop, do not generally occur in plywood. But with some plywood basses, I have the impression that the narrow veneer edge splinters more easily precisely because the veneer has been cut through for the inserted chip.

In this respect, a painted purfling on plywood basses is not a “cheap trick,” but rather offers structural advantages.

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Lufthansa changes rules for carrying (small) musical instruments

After violinist Caroline Widmann was forced to take her Guadagnini violin on board a flight without a protective case, she contacted the Lufthansa board. Her appeal was successful: the airline has now adjusted its rules for transporting musical instruments.

A sum rule is applied: the height plus width plus depth of the packed instrument must not exceed 125 centimeters in total. This allows instruments that are longer than the regular maximum length of 55 centimeters to be taken on board. We have reviewed and implemented the adjustment to the regulations for small musical instruments based on various customer feedback.

For the double bass, everything remains the same – but carrying a double bass bow may now be easier.

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… and another removable neck conversion

This bass came to my workshop because the neck had come loose. After I removed it completely, it became clear that there was so much air in the glue joint that it couldn’t hold…

The neck joint on this bass is designed as a hidden dovetail joint, but it is so imprecise and has so much play that the glue joint to the back plate alone actually bore the entire load. We therefore decided to chenge the neck joint to a screwed connection. The reason for converting to a detachable neck was not easier travelling, but the screw promises to be the most durable connection here (a completely new and cleanly inserted neck was ruled out for cost reasons).

During the renovation, it became apparent that someone had already attempted to solve the problem of the loose neck with a screw: someone had screwed it in from above through the neck foot, but it was crooked from every angle. It eventually broke, and during another repair attempt, the screw hole was doweled again. However, the broken-off remainder of the screw is still stuck in the neck block.

After patching the dovetail joint, the neck is now securely held in place by an M8 screw—the counter thread was inserted into the neck block from the inside (bottom).

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six stringer

A double bass with six strings?!? No, a violone. This instrument, which belongs to the viola da gamba family, looks quite similar to a double bass, but the body is slightly larger than that of a ½ bass, while the scale length is slightly smaller at 90 cm.
This G violone was built in 1962 by luthier Uebel in Celle/Germany. The tuning pegs are mounted in such a way that the direction of rotation of the pegs is the opposite of what you would expect from a bass. This means that you have to turn “downwards” to tune up. At first, I thought this was a mistake… something that can happen even to the most skilled instrument maker. However, I now assume that the tuning pegs were deliberately mounted this way so that the gut strings could be threaded over the pegs from below, rather than from above as is usually the case. This makes the angle at which the strings run over the nut slightly more acute, and the relatively thin and soft gut strings lie with a little pressure on the nut. The fairly wide notches in the original saddle indicate to me that the strings were previously strung in this way.