I am considering the purchase of a Focus 2. When I have to double, I'd like to be able to use the instrument channel for DB, since the high pass filter is particularly useful and only works with that channel. So that leaves the mic channel for BG (XLR input), which I assume would require a transformer or preamp/direct box with XLR out. Anybody do this or could speculate how/if it would work? Any drawbacks to this scenario? Or recommendations as far as what to use for the conversion? Thanks!