The FET-type solution was first used for its application in the legendary UREI 1176 compressor from the 70s. The most important feature inspired by revision A is the input transformer used and pure class A output stage. The compressor is equipped with a relay bypass, 2:1 Ratio and Slam Mode accessible on the front panel. The 576 BS’s major selling point is its ultra-fast attack time — 20 µS. The 576 BS Ratio buttons allow four different modes of operation: 2:1 Ratio (soft compression); 4:1 ratio (moderate compression); 8:1 ratio (severe compression); 12:1 ratio (mild limiting); 20:1 ratio (hard limiting); S – SLAM, All Buttons In trick mode.