i think i may have figured this out ...
everything that is unbalanced does not matter, it already has "correct" polarity (for instance, a mic placed in frony kick drum moves forward from the speaker instead backward into the speaker when playing back) inherently since it is "hot" only.
when using a balanced line, if i use a "pin 2 hot" connector into a "pin 3 hot" input, i have a reversal. so all of my line signals going in are going to have a reversed polarity from all of my mic preamp signals!
if i use an external preamp, "pin 2 hot" with a "pin 2 hot" xlr, then go into the tape machine, the polarity will be correct. but then it will be mixed with my other tracks, some of which are correct (the ones that began as direct lines) and some of which are incorrect (the ones that began as mic/xlr).
so the only way for all of it to be correct polarity is to use "pin 3 hot" wired xlr, or use adapter cables like the previous poster suggested.
but after researching this issue, i am not sure that i care if the polarity is correct or not. it seems that in the 1960s (and before) and even into the '70s, there was no standard so "pin 2 hot" and "pin 3 hot" were used interchangably. for instance, if you recorded some tracks on an ampex machine, then played that tape back on a studer and overdubbed more tracks, you would have some tracks with correct polarity and some tracks with incorrect polarity.
of course, it also depends on how you recorded it in the first place. if you placed a mic on the drummer's side of the kick, the attack would recede from the speaker. if you reverse the polarity, the speaker would move forward.
i have no idea what happend if the mic was at the side of the kick!!!