The m502 is a 500 series opto compressor module.
From gentle dynamic smoothing to full tilt squash, this unit delivers open, musical dynamic control that is the perfect companion to any high fidelity mic preamplifiers or any recording chain. All your tracks can now have glorious, easy to use compression which regardless of how much you squeeze, will always end up with their sonic essence perfectly intact.
The heart of the compressor circuit is an optical attenuator - the purest, high fidelity gain control mechanism available. With careful attention to control circuit design, Grace are able to implement a feedback opto compressor that not only provides a wide range of dynamic control, but remains inherently neutral, open and musical.
Including input and output level, threshold, attack, release and ratio controls. The m502 includes connectivity for sidechain input, and stereo linking.