Ultimate Opto Upgrade The T4b opto cell is the beating heart of the most iconic optical compressor ever made. Black Lion Audio — a company famous for their performance-chasing “hot-mod” design philosophy — collected a bevy of commercial and boutique opto cells and put them on the bench in an attempt to find one that met their stringent requirements. No dice. So, they designed their own. The Black Lion Audio T4BLA optical cell delivers the perfect “feel” and “sag” that engineers at GearNuts want from their own opto compressors. Tested and certified to be compatible with a range of today’s optical compressor units, the Black Lion Audio T4BLA opto element is an excellent upgrade that makes an immediate audible difference.About Black Lion Audio Founded in Chicago in 2006, Black Lion Audio has made their mark on the audio industry by hot rodding audio equipment and upgrading the sound quality of