so, i'm now pretty much convinced that i've fixed the problem and established consistency in what the device is producing. but, the results of that aren't always positive. in some cases, it's pretty bad. i knew the gear wasn't really behaving, but i can only deal with what i can actually hear. the first three tracks are spot-on perfect. after that, it gets pretty messy.
the general problem is that the mixes are treble-heavy and sort of tinny. this is actually backwards; they're meant to be very bass-heavy. i guess the device was sort of exaggerating the bass, so i cranked the treble in response. then, when i was playing it back, it seemed like the bass was cutting in and out. but i can tell now that what was happening was that it was distorting and coming back, and i was mixing it in the distorted position, then getting pissed off when it righted itself.
so, i need to apologize for the bulk of the mixes i've uploaded over the last few weeks. they are not good. but, the gear was fucked.
that means i have more work to do than i thought. but i get the impression that these are fixes i can do at the master eq level; it's going to be mostly be an across the board cut around 10,000 Hz - and in most cases, it's going to be undoing what was actually a boost at that frequency.
moral of the story: don't mix on a broken mixer.
10 kHz was the frequency of the treble knob on the tascam that i mixed it on originally. i boosted at that frequency in an attempt to emulate what i know i did all those years ago. it seems high, but it's not arbitrary.