The N90-DRC/500 compressor also known as the David Rees Compressor is an API 500 format series compressor & gate. This product was originally conceived 20 years ago by David Rees but was never fully released.  The Phoenix N90-DRC/500 compressor/gate is designed around a VCA control with Class A discrete input and Class A transformer balanced output. The N90-DRC/500 is intended to be driven ‘by ear' .There are no optimum settings that would cover all situations.  It is intended to be very musical and smooth and has quite a wide ranging effect. Musically the progressive curves are very kind - there is no sudden change on passing the threshold and audio processing is virtually "seamless". Technically the progressive curves are achieved using linear detection combined with logarithmic attenuation inside a closed control loop. "Limiter sound" is still provided by the higher ratios and there is a choice of attack times. The gate is more conventional but it's release time is composite with a hold time followed by a fade time.  This makes the gate very versatile in that as well as basic noise reduction it can also provide quite subtle changes to ambience or background.