That is a an excellent method to evaluate cables. It is absolutely safe to connect 2 sets of interconnect to two different inputs. Ensure that the two inputs you use are high-level inputs --not a tape loop. Anytime you move cables and reconnect wait about 20 minutes or so until the cables re-settle in --then begin to compare. Do the test several times over some hours and jot down your listening observations. As a final test, use the IC's individually and listen again. That will confirm (or not) your listening tests with the Y conectors and determine if it had any sonic degradation upon the individual cables sound.
Have fun. It really is amazing the impact such so-called passive components make.
peter jasz
Have fun. It really is amazing the impact such so-called passive components make.
peter jasz