Vincent Bach LT50A3LG double rotor bass trombone

The Bach Stradivarius 50A3 is a double rotor bass trombone with open wrap F and G-flat attachments which can be accessed independently using two Hagmann* rotary valves.

The LT50A3LG variant has a larger 10½-inch gold brass bell and lightweight nickel silver hand slide.

Note: model pictured is 50A3 standard model.

• Lacquer finish
• Bore size: 0.562 in. (14.27 mm)
• Key of B-flat/F/G-flat
• 10½-inch gold brass bell
• Double inline/independent Hagmann* valves
• Lightweight nickel silver hand slide
• Open wrap
• Bach 1½G mouthpiece
• Woodshell case

Along with a larger bore and bell diameter, bass trombones are often equipped with a second rotor to extend their low register. There are two double-rotor systems: ‘independent’ and ‘dependent’. An independent system has both rotors sitting side-by-side (or ‘inline’) on the neck-pipe, where they can function alone or in tandem. Dependent models locate the second rotor on the F attachment rather than the neck-pipe, hence the alternative descriptors ‘stacked’ or ‘offset’. In this configuration, use of the second rotor depends on the first rotor being simultaneously engaged.

Also available in the Bach 50B3 range:

Other model variant: ^†LT50A3LG

*The Hagmann free-flow valve appeared in the early 1990s as a further development away from the traditional rotary valve, following the introduction of the more complex Thayer axial-flow valve in the 1980s. The Hagmann design minimises distortion of the air flow inside the valve, resulting in a rich, full sound, and is easy to maintain using regular valve oil. Vincent Bach introduced the Hagmann valve into their Stradivarius trombone range in 1999.

Manufacturer’s website: conn-selmer.eu