any body knows where at the "VOL" knob is 0dB ??? it goes from 0 to 10, so maybe its at 12 o`clock (5). other question, how does the "optical compressor" work? i can understand the standard (VCA) compressor, but ive been told that opticals had something to do with light... so what do the "drive" control does? (treshhold? rate? ¿?) and: what does the "sorce: dry/wet" does?¿ thancks!