King 6B Duo Gravis
Bb/F/D large-bore bass trombone · professional · vintage
Landmark early-1970s dependent double-valve bass trombone; free-blowing with a lighter feel than modern independent basses.
| Type | bass |
|---|---|
| Key | Bb/F/D |
| Bore class | large |
| Bore size | .563″ |
| Valve configuration | Double valves (dependent) |
| Valves | 2 |
| Rotor type | traditional rotary |
| Wrap | closed wrap |
| Bell diameter | 9.625″ |
| Bell material | rose/gold brass |
| Slide | nickel silver |
| Finish | clear lacquer |
| Level | professional |
| Era | vintage |
| Country | USA |
| Years | early 1970s (H.N. White / Eastlake era) |
Features: King's first dual-valve bass trombone and one of the first American production DEPENDENT-double-valve basses; the 'Duo Gravis' name was applied to the dependent-valve model. Designed by George McCracken. 9 5/8" gold-brass bell.