A new sinusoidal model based engine for FESTIVAL TTS system which performs the DSP (Digital Signal Pro- cessing) operations (i.e. converting a phonetic input into audio signal) of a diphone-based TTS concatenative sys- tem, taking as input the NLP (Natural Language Process- ing) data (a sequence of phonemes with length and into- nation values elaborated from the text script) computed by FESTIVAL is described. The engine aims to be an alternative to MBROLA and makes use of SMS ("Spectral Modeling Synthesis") repre- sentation, implemented with the CLAM (C++ Library for Audio and Music) framework. This program will be released with open source license (GPL), and will compile everywhere gcc and CLAM do (i.e.: Windows, Linux and Mac OS X operating systems).