So, I finally got a Beta Lead(after a somewhat painful experience, courtesy of ebay), and though advertised as in perfect playing condition, of course the pots are scratchy, but most surprisingly was that the mid-range dial on the A channel causes some serious microphonic feedback. I'm pretty sure this isn't something intentional in the design, but I know the EQing on the Beta Lead is very particular, and I wanted to make sure(before I tear the seller's head off) that I wasn't doing something incorrect on my end.
To clarify, I have to have the mid rolled all the way back, otherwise it sort of pops, and then squeals. It sounds amazing otherwise, I'm just not really looking for that 'microphone pointed at a stage monitor' sound.