Audio compressors that use a light source to control a Light Dependent Resistor (LDR) are not new, and indeed there are many classic optical compressor designs. The design goal of the SOC-1.1 was to further enhance the attributes of optical compression to provide the user with alot more functionality as well as improve the compressor response to real world audio signals. Buzz Audio has carefully examined the characteristics of the LDR and developed a truly unique process to control it. This process they call the Differential Drive Side Chain topology (DDSC).