Willson K56S K-Series Intermediate Bb Euphonium in Silver Plate SN K10007

Willson K56S Euphonium Overview

The Willson K56S K-Series euphonium combines the traditional 3+1 compensating format with a large-shank mouthpiece setup in a model positioned between Willson's foundational A Series and its higher-tier Q and Swiss Pro instruments. Willson is an established Swiss maker with a strong presence in the euphonium community, and the K56S is designed for musicians seeking a serious step-up instrument for concert band, brass band, and solo study.

Willson K56S Euphonium Specifications

• Key: Bb
• Valve Configuration: Three top-action pistons and one side piston with compensating system
• Bore Size: 0.590 in (15 mm)
• Bell Diameter: 11.5 in (290 mm)
• Bell Material: Yellow brass
• Finish: Silver plate
• Case: Willson padded case
• Accessories: Laskey 59D mouthpiece, valve oil, and polishing cloth
• Serial Number: K10007

Condition & Setup

This used euphonium is in excellent playing order and has been professionally serviced, set up, and play-tested. Its silver-plated surfaces remain bright and reflective, with minor scattered scratches and handling marks on the body, lower bow, and bell. The bell has localized residual scarring. The included case and accessories provide a practical outfit for transport and routine care.

Who the K56S Euphonium Is For

The K56S is well suited to advancing students, adult ensemble musicians, and school or college programs seeking a compensating euphonium beyond an entry-level design. Its yellow-brass bell follows a traditional, centered euphonium sound concept, while the 3+1 compensating system supports secure low-register fingering and intonation. Players who want these features without moving into Willson's Q or Swiss Pro lines should find the K56S particularly relevant.

Common Questions About the Willson K56S

What does the compensating system do?

The compensating system routes the air through additional tubing when the fourth valve is combined with the first three valves. This helps correct the sharp low-register tendencies found on noncompensating four-valve instruments.

How does the K56 differ from the Willson K46?

The K56 adds a compensating system and uses a 0.590-inch bore, while the K46 is a noncompensating model with a 0.571-inch bore. The K56 is therefore intended for players who need greater low-register flexibility and a more developed step-up configuration.

What mouthpiece shank does the K56S use?

The K56S uses a large-shank mouthpiece receiver. This instrument includes a Laskey 59D mouthpiece.

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