Yeah, the pre is fine, Busman Mod +. He was nice enough to offer up to look at it, but after mastering the recording more, especially the main sets, it became very clear that it only happened when a horn was "blasting," or "muted". I didn't notice that at first, but did after spending some quality time with the recording. It was totally predictable, and sometimes it was on the plus side and sometimes the minus side (this was a 10+ -piece big band), which still seems a bit odd, but that might have been a FOH issue between the mics/pres the FOH was using? Not sure, but it all sounded fine. Anyway, after some searching, I learned that asymmetircal waveforms are totally normal for horns. Funny thing is, the artists I asked had no clue WTF I was talking about or even asking. Well, now I know, but on that first set, I clipped the hell out of the one side. Oh well, live and learn.