Plugging a cable into BoB''s output 3-G automatically takes the unit out of 2x3 mode and puts it into Hex mode (enabling a separate output for each string). When you unplug from output 3-G, outputs 1-E and 2-B switch from outputting signal from the guitar''s first and second strings, respectively, to outputting signal from the three highest and three lowest strings, respectively. The state of BoB''s outputs 4-D, 5-A, and 6-E (plugged or unplugged) have no effect on 2x3 output mode and remain active whether or not output 3-G is in use. Therefore, you can output the separate signals from strings 4, 5, and 6 simultaneously with those from the summed three upper and summed three lower strings as long as output 3-G is unplugged.
BoB''s outputs deliver different signal levels depending on the mode used. Oddly, I found that outputs 1-E and 2-B provided levels roughly 8 dB lower in 2x3 mode compared to in Hex mode. BoB''s Classic output is about 14 dB weaker than output 1-E is in 2x3 mode, making the Classic output suitable for use only with a guitar amp; it provides much too weak a level for connecting directly to an I/O box. When in Hex mode, you''ll probably need to tweak output levels for each of the six strings in your DAW or mixer. My review unit produced output levels roughly 3 dB hotter for the second, fourth, and fifth strings compared with those for the other strings. Patching each string''s output into a separate input on a MOTU HD192 High Definition I/O box, strings picked hard, produced healthy levels ranging from –4 to 0 dBfs with the guitar''s master volume turned all the way up.