Golden Age Project PRE-573 MKIII 500 Series Microphone PreampTHE PRE 573 MKIII IS THE 500 SERIES RACK VERSION OF THE PRE 73 MKII WITH SOME ADDITIONAL FEATURES. The PRE 573 MKIII is a one width module for the api 500 format that has the sound and the features that made the PRE 73 so successful and a few additional ones. The circuit still uses the preamp and output section from the classic 1073 module, adapted to work in the api rack format. It has a total gain range from 10 to +80 dB. The 20 70 dB range is