I know this is an old thread, submitting this data for future reference. Just in case someone might need this later.
I searched the entire internet and finally had the thought of maybe actually asking the manufacturer (I know, crazy idea).... This is what they provided me.
This is for the CR-310, ten audio channel unit. The CR-320 is a twenty channel unit, and this should give you enough info to decipher (or guess-timate) the connections for the other 10 channels.
The input connector is a 50 pins (25 pairs) Amphenol type connector. The input impedance is 10K Ohm (1Khz) and above.
Line 1 = Pin 1 & Pin 26 (Ring & Tip)
Line 2 = Pin 2 & Pin 27 (Ring & Tip)
Line 3 = Pin 3 & Pin 28 (Ring & Tip)
Line 4 = Pin 4 & Pin 29 (Ring & Tip)
Line 5 = Pin 5 & Pin 30 (Ring & Tip)
Line 6 = Pin 6 & Pin 31 (Ring & Tip)
Line 7 = Pin 7 & Pin 32 (Ring & Tip)
Line 8 = Pin 8 & Pin 33 (Ring & Tip)
Line 9 = Pin 9 & Pin 34 (Ring & Tip)
Line 10 = Pin 10 & Pin 35 (Ring & Tip)
I have also attached a pdf of the pinouts for several other connectors on the back of the machine.
Happy scanning,
Rob