SWAM-S stands for Synchronous Waves Acoustic Modeling – Strings.
Differently from SWAM, sound is generated by pure Physical Modeling, so there are no samples at all.
We have performed an in-depth study of the Physical Modeling techniques, especially the Digital Waveguides Synthesis by prof. Julius O. Smith. Using this technique, adding new elements and performing an unceasing fine-tuning, we have built the best modeled Bowed Strings virtual instruments on the market, allowing the real-time control of bow speed, bow pressure, bow position, vibrato, portamento, harmonics, tremolo, pizzicato, and many other parameters in a realistic way, almost indistinguishable from the real instrument.
Ref. The Physics