Assuming the wording you quoted is stated precisely, I would interpret it to mean that the number you should use is 100K.
"For each phase" would seem to mean 50K input impedance between "hot" (xlr pin 2) and ground; and 50K input impedance between "cold" (xlr pin 3) and ground. That would mean that the input impedance between pins 2 and 3 (which corresponds to the sum of the input impedances between each of the two input signal polarities and ground) is 100K.
Regards,
-- Al
"For each phase" would seem to mean 50K input impedance between "hot" (xlr pin 2) and ground; and 50K input impedance between "cold" (xlr pin 3) and ground. That would mean that the input impedance between pins 2 and 3 (which corresponds to the sum of the input impedances between each of the two input signal polarities and ground) is 100K.
Regards,
-- Al