D'Addario H412 MM Viola Strings

D'Addario Helicore Viola Single D String — Warm Tone, Quick Bow Response

The Helicore Viola Single D String is a drop-in replacement string sized for medium-scale violas with a body length of 15 to 15 3/4 inches and a 360 mm playing length. It uses D'Addario's signature multi-stranded steel core, the same construction that has made Helicore one of the most widely used orchestral string lines among students, teachers, and working professionals. The stranded core produces a clear, warm tone with a smaller string diameter that delivers quick bow response and easy playability under the left hand. Compared to many factory-installed strings, this D offers noticeably faster break-in time and more focused projection across the instrument's mid-range register. Each string ships in a uniquely designed sealed pouch that protects against corrosion before installation.

Technical Specifications

• String Type: Single replacement D string
• Instrument: Viola
• Scale: Medium scale (body length 15–15 3/4", playing length 360 mm)
• Tension: Medium
• Core: Multi-stranded steel
• Ending: Ball end
• Material: Stainless steel
• Country of Manufacture: USA

Who This String Is For

The Helicore Viola Single D String is the right choice for violists who need a reliable, fast-response replacement D string for a medium-scale instrument. It suits classical players who want a warm, focused tone without excessive brightness, as well as players working in alternative styles such as folk, bluegrass, jazz, or electric viola setups where quick bow response and a flexible feel matter most. The medium tension is optimized for the majority of players, making it a practical upgrade or replacement for students stepping up from a basic factory set, teachers who need a consistent backup string on hand, and working professionals who want a D that settles in quickly and holds pitch. Helicore strings have been endorsed by artists such as Brittany Haas and Jean-Luc Ponty for their adaptability across genres and playing environments.