📜 Historical Perspective
The Bach 50AF3 bass trombone with detachable bell flare, commonly referred to as a “screw bell” bass trombone, was developed to give professional players the full performance of a large orchestral bass trombone while solving one of the biggest practical challenges of modern musicians: travel and portability.
Traditional bass trombones require large hard cases that can be cumbersome when flying or navigating crowded urban environments. With the detachable bell design, the bell flare can be unscrewed from the bell tail, allowing the instrument to fit into a much smaller detachable bell travel case, such as those produced by Marcus Bonna and other professional case makers.
This particular Bach 50AF3 was converted to a detachable bell configuration and features a bell flare that has had the lacquer removed while the valve section and tuning slide retain their original lacquer finish. The result is a visually distinctive instrument that maintains the classic Bach bass trombone design while offering improved portability.
The instrument remained very lightly played, with the handslide and valve section in excellent condition. The slide is smooth and responsive, and the valve section functions properly without signs of wear or mechanical issues.
Included with the instrument was the original factory case and mouthpiece, both in excellent condition.
For players who travel frequently, walk long distances to rehearsals, or simply prefer the convenience of a smaller case, a screw bell bass trombone can dramatically reduce the risk of damage during transport, particularly to the bell flare — the most vulnerable part of the instrument.
When this instrument was originally offered, new Bach 50AF3 bass trombones were selling for over $6,700 factory new, with open-box examples sometimes advertised around $4,600. As of 2026, new Bach 50AF3 models commonly sell for over $7,000, reflecting the continued demand for professional bass trombones with detachable bell systems.
📸 Photography From Our Early Archive
Some of the photos shown on this page date back to the earlier years of The Brass Exchange. Over time our photography techniques have evolved significantly as we refined our studio lighting and developed methods specifically for photographing brass instruments.
While these earlier images may not reflect our current studio standards, they remain an important part of documenting the instrument’s condition and history at the time it passed through our shop.
Questions Trombone Players Often Ask
How does a detachable bell (screw bell) bass trombone play compared to a standard bell?
A detachable bell (screw bell) bass trombone typically plays very similarly to a traditional one-piece bell when the flare is properly installed and tightened. The threaded collar used for the detachable system does add a bit of extra weight to the bell section. Many players feel this added mass gives the sound a little more core and authority, especially in the low register. The trade-off is that the bell can require slightly more energy from the player to fully resonate, but most musicians adapt quickly. After a short adjustment period, many players find the instrument responds naturally while offering the significant advantage of improved portability for travel.
Why do players choose detachable bell bass trombones?
The main advantage is portability. Detachable bell instruments can fit into smaller travel cases, making them easier to transport on airplanes, public transit, or long walks to rehearsals and performances.
Can a detachable bell help protect the instrument when traveling?
Yes. With the bell flare removed, the instrument fits into compact cases designed to protect the bell separately, reducing the risk of dents or creases during travel.
🔧 Availability & Archive Status
This Bach 50AF3 screw bell bass trombone has been sold and is now shown here as part of The Brass Exchange historical archive.
Archive pages serve as a reference resource for musicians researching professional trombones and historically notable instruments that have passed through our shop.
👉 Looking for a professional bass trombone or detachable bell model?
Browse our current trombone inventory here:
https://thebrass-exchange.com/trombones
