The HERCHILD Model 660 is a Tube-based Variable-Mu compressor meticulously designed to replicate the classic Fairchild sound. Featuring 11 valves and 5 transformers, it operates at high voltage for professional results. With 6 Attack and Release times, a unique DC THRESHOLD for ratio and knee control, and a SC FILTER for side chain frequency adjustment, it offers precise and versatile compression options for modern production needs.