Conn 70H
Bb large-bore bass trombone · professional · vintage
Landmark early American single-valve bass trombone; warm, dark, resonant core with edge when pushed — George Roberts' studio sound.
| Type | bass |
|---|---|
| Key | Bb |
| Bore class | large |
| Bore size | .562″ |
| Valve configuration | F attachment |
| Valves | 1 |
| Rotor type | traditional rotary |
| Wrap | closed wrap |
| Bell diameter | 9.5″ |
| Bell material | yellow brass |
| Bell construction | two-piece yellow-brass bell |
| Slide | nickel-silver inner / gold-brass outer |
| Finish | clear lacquer |
| Level | professional |
| Era | vintage |
| Country | USA |
| Years | 1930s–50s Elkhart |
Features: Tuning-in-the-slide (TIS) with "opera-wheel" tuning on early examples; interchangeable valve slides. The horn that built the modern bass-trombone market.
Known players
Allen Ostrander, George Roberts