Set it and forget it! Our ELOP® Limiters make your job easy. The principle of operation is based around using a rectified sample of the audio to shine an LED (Light Emitting Diode) onto an LDR (Light Dependent Resistor). The photo-resistor in combination with a fixed resistor simply act as a changing voltage divider to attenuate the signal-- like a smart volume control. A similar principle was found in the older **Teletronix & Urei **LA-2A, LA-3, and LA-4 units which used a slower electro-luminescent panel-light on a conventional LDR encased in a light-tight enclosure. Ours uses modern VACTROL technology (but with a trick!) for exact sample-to-sample tracking and no high frequency loss while digging deep into limiting-- problems commonly associated with older LA-series limiters and other opto-based units.
The audio signal passes only through our super-clean single-ended vacuum tube line amplifiers in the Manley unit, and through all-discrete Class A amplifiers in the Langevin version. Each channel can be run separately or switched to stereo - link . Due to their inherently quick attack, these Electro-Optical Limiters are skilled soldiers for tracking vocals or individual instruments, although now with the addition of a very useful sidechain high-pass filter that can switch between 100Hz or 200Hz (or OUT) to allow the limiter to ignore heavy bass lines, the ELOP® limiter is proving more useful for modern urban music where you dont want the limiter only responding to the loudest thing i.e., the BIG bass. If you want the bass line to leave the rest of the mix alone, then this switch is for you !