With Spirocore strings, the ground-breaking innovation of an ultra-flexible metal spiral core was perfected by Thomastik-Infeld in 1957. They rank among the most used cello strings due to their unsurpassed responsiveness, lifespan and sound.

The set Spirocore S31 represents a technical revolution of the early 1950s. Its strings´ spiral rope core has a much greater elasticity and therefore a higher vibration capacity with less damping than other rope core strings. This design enables strings to move quickly, making them extremely reactive to impulses of the bow. Due to their superb bowing hand agility, Spirocore strings respond exceptionally easily to various bowing techniques for articulations of all kinds. Their sound is nicely balanced, full and powerful. The two low-tensioned upper strings (A and D) provide a fine, bright and slightly metallic sound character which follows the unforgettable tradition of cello sound. The lower strings (G and C) have been recognized as "reference standard" worldwide and are a perfect match with other A- and D-strings from Thomastik-Infeld’s modular cello string selection. Spirocore strings have a good break-in time and a particularly long lifespan. The twin set S3233 includes the Spirocore G-string S32 and C-string S33. Their innovative design with a tungsten winding on an ultra-flexible spiral core was developed and perfected by Thomastik-Infeld as early as 1957. Since then, these strings have achieved an iconic status among cellists of all levels. Up until today, the Spirocore S32 and S33 are regarded as the most powerful, focused and high-performance cello strings. Their tonal essence is a wide, deeply resonating sound with a brilliant edge and clear focus. Their famous round „roaring“ growl with superb projection has inspired cellists all over the world as a role model of sound imagination. They can be heard on countless top-level recordings made in the past six decades. Their very accurate bow response allows an immediate reaction to a bowing hand impulse at any bow-speed and even high bow pressure. Their flexible and elastic spiral core assures best fifth purity even at highest volume. These strings are designed with an outstanding lifespan and unsurpassed durability. Cellists of different levels trust Spirocore as their preferred string choice for the most challenging concert conditions. Furthermore, S3233 combines perfectly with all A- and D-strings in Thomastik-Infeld’s modular string selection.