15. MASTER output (or Main or Mix) = channels 1-2 (2 x RCA, and 2 x 1/4” / 
6.35 mm mono jack), for connecting active speakers 
16. MIC (microphone) input (1/4” / 6.35 mm mono jack):  balanced input, 
compatible with both balanced and unbalanced microphones 
17. AUX (auxiliary) stereo input (2 x RCA, and 1 x 1/8” / 3.5 mm stereo mini-
jack) 
18. USB port (type B) 
19. Hercules Add-On Reserved: reserved extension port 
 
 
 
20. Stereo headphones output (1/4” / 6.35 mm stereo jack, and 1/8” / 3.5 
mm stereo mini-jack)