Do you want to improve your sound or playing experience? You may have already noticed that there are different valves on trombones. There is the classic rotor valve, the Thayer valve and the Hagmann valve. I would like to explain the differences to you below:

Traditional rotary valve:

• This valve is the most common. Perhaps it is what you imagine when you hear the term "trombone valve". Basically, it is a simple cylindrical valve housing with a rotor inside. This rotates so that the air flow is diverted by 90°. Consequently, the length of the tube changes and thus the pitch. The sound of the resulting valve notes is often described as compact and direct.

Rotary valve of a Conn 88h

Thayer valve:

• The Thayer valve is a modern variant of the valve. Orla Ed Thayer invented it in 1976. The conical version that we know today was patented in 1985. It has a more open design with a conical rotor that allows the air to flow more efficiently. This results in a very open sound and almost resistance-free valve tones. Not everyone likes the ergonomics and appearance of the Thayer design. The lever travel tends to be a bit longer. In return, you have the smallest bend in the air column at just around 20°. This results in a sound rich in overtones.

Axial valve on a Bach 42AF

Hagmann valve:

• Another very popular variant is the Hagmann valve. It was invented by René Hagmann in 1990. He wanted to optimize the classic rotary valve. Consequently, his valve is low-maintenance. It avoids the sharp 90° curve that the rotary valve has. The air column only has a 45° bend here. As a result, it enables an open sound with little resistance.

Hagmann valve on a Bach 42A

These three valve designs are the predominant designs. The "Infinity" axial valve from Bach, for example, is based on the Thayer design. The Bach Miller valve or the Shires Tru-Bore are basically variations of the Hagmann design.
Every design has its advantages and disadvantages. Consequently, there are pros and cons in all areas of music. What suits you?