Tascam M-520 - M-520, Last 4 VU Meters & Function Switches AUX (1, 2 or 3, 4);I;ST MSTR (A or B); MON BUSS;(OFF);TAPE Signal Select Switches; MON Level Control (x8 in M-512, x16 in M-520); MON Pan Control (x8 in M-512, x16 in M-520)