Thayer valve
The Thayer valve (also known as the axial valve ) is a new development of the conventional rotary valve on quart and bass trombones . It was first presented by Orla Ed Thayer in 1976 and represents the most important trombone innovation since the introduction of the quart valve in the middle of the 19th century by Christian Friedrich Sattler . Master Franz Monschau from Musik Haag AG Kreuzlingen / Wil / St. Gallen CH was the first in the world to install a Thayer valve in a series trombone.
problem
If a conventional rotary valve is operated, it diverts the air flow through a pipe loop with at least three additional bends, which often cover angles of 90 ° and more. This leads to deficiencies in response and sound differences compared to the "open" instrument.
With the trombone in particular, these disadvantages are much more noticeable than with other brass instruments, as the characteristic timbre of the instrument is a direct consequence of its largely straightforward construction: apart from any valves, trombones only have two bows and - especially in American design - an almost completely cylindrical length .
The difference in sound when the valve is activated is further exacerbated by the laying of the valve loop in narrow radii within the body, which was common practice until the 1980s (“traditional wrap”).
The softer sound of “horn-like” instruments, which can be clearly distinguished from trombones, is due not least to their largely conical length and their more intricate design with numerous windings and bows.
solution
The advantage of the Thayer valve with conical alternation is that it does not deflect the airflow by more than 25 degrees. This also makes laying the valve loop in a more straight line in softer arcs with larger radii ("open wrap") particularly effective. As a result, the response behavior and the sound hardly differ from the open instrument when the valve is operated - not even with bass trombones with two valves connected in series. Some trombonists even report that they respond more freely than open when the valve is activated .
criticism
Some trombonists and instrument makers complain about increased cleaning and maintenance requirements or even lower reliability of the Thayer valve compared to the conventional rotary valve. Others suspect that such problems are not construction-related, but rather stem from a lack of expertise.
Bass trombonists in particular sometimes take the view that a certain increased blowing resistance is even conducive to the response of lower valve tones (below Eb). This group feels that newer constructions with less resistance are more strenuous to play, and they sometimes criticize a “colder” sound.
The Openwrap construction method is largely independent of the valve used, but is sometimes criticized insofar as the valve loop is less well protected from damage when it is laid in this way than with the traditional construction method.
consequences
The Thayer valve triggered an "arms race" among the trombone manufacturers, which continues to this day. This is possibly due to the pronounced instinct to play many trombonists, while players of other instruments often prefer traditional construction methods rather than innovative constructions.