The TUBE-TECH CL 1B Compressor is an optical, all tube based compressor targeted at single-track studio recordings: It is equally suited for delicate vocal recordings as well as critical instrument recordings such as lead guitar, drum solos etc.
Half rack mono compressor/limiter, using electro-optical attenuation. Designed to respond to RMS levels, this makes it more 'musical' than units designed primarily to protect against overloads.