Incredible DSatz, thanks for the white paper of your own!
Let's get stuck in...
Only one wire (say, the one connected to XLR pin 2) is directly driven by the microphone's output circuit, which has a certain output impedance. The other wire (say, the one connected to XLR pin 3) is connected to a resistor that matches that output impedance. To improve the match at higher frequencies (which is important, since any interference is rejected only to the extent that the hookup is balanced at the frequency of the interfering signals), a series capacitor can also be used.
Aha! Aha Aha ahaha ha! I get it now
reading Chris319's link helped a lot too (cheers chris!). So THIS is what we're looking for (just with an added capacitor?):
So the clever bit (one thereof...) is that pin 3 [cold] is being subtracted from pin 2 [hot], but the cold wire isn't carrying any signal, just noise and interference, which will be cancelled! Great! One question - could both channels share one resistor and capacitor, or would I need one set for each channel?
So yup, alas the consumer/professional audio dialectic has not been throwing up any kind of positive synthesis, only trouble, trouble, and more trouble!
In terms of implementation then, it's got to be the Balance Box doesn't it. No way to really implement this in a cable as such..? Unfortunately I think building a boxed unit is probably above my present ability in these things, and certainly beyond my time and money resources, for now. But great to know theoretically how it would be done, really appreciate the knowledge imparted here, thanks.
I'm thinking I might go for the pseudo-balanced lifted sleeve approach mentioned before. I figure get a 5pin XLR to 2 x 3 pin XLR cable and swap the 5pin for a 3pin with the two sleeves disconnected. Add TRS adaptors for Microtrack. Hopefully, from what I've read, that will avoid the nasty MTII "sprinkler" noise, and give me a bit less noise going into the UA-5.
To be honest I'm even starting to worry whether I can afford to buy cables for this setup (was banking on getting a grant to go and conduct research this summer, but the grant fell through. Still going, just with little to no money!)
Whatever I end up doing, I'm damn glad to know all my options! If I do end up getting into building myself a Balance Box, or even trying to get these cable shenanigans to work, I'll post back to update (and most likely to weep "WHY WON'T IT WORRKKKK???")
Many thanks for the valuable info everyone, particularly DSatz, ya star