The Yamaha YSL-645 is a vintage medium bore professional trombone from the 1980s, serial number 010296. Built during a time when Yamaha’s pro models were gaining wide recognition for craftsmanship and durability, the YSL-645 features an 8 3/8" yellow brass bell and a straight .525 bore brass handslide with brass end crook — offering a bold, flexible tone that fits a wide range of playing styles.
This instrument received full shop service here, including a chemical bath and complete mechanical inspection. The handslide is fast and responsive with no plating issues, and the bell has a medium-weight feel — not overly light like some modern horns, which helps generate a strong, centered tone with excellent projection.
Tested with a small shank Bach 6½ AL mouthpiece (not included), it performed beautifully, but the horn can accommodate a range of mouthpiece sizes depending on your tonal goals. This model was Yamaha’s top-tier straight tenor at the time, and today it remains a great choice for advancing players in jazz, concert band, or chamber settings who want something more substantial than a .508 bore without stepping into large bore territory.
Cosmetically, the original bell lacquer is excellent, while the outer slide shows some typical grip wear. Original Yamaha case included and in very good condition.
What makes the Yamaha YSL-645 stand out among vintage straight tenor trombones?
The YSL-645 strikes a rare balance between agility and depth. With its .525 bore and medium-weight bell, it allows for a broader dynamic range and greater projection than smaller-bore horns, yet retains flexibility and ease of control. Many players today find it ideal for crossover work between jazz and classical styles.
This Yamaha YSL-645 has been sold and is now listed in our Archive of Sold Instruments. Interested in seeing what’s available now? Browse our current trombone inventory 🔎.
