Dunno, I was just under the impression that the HX FX only had the effects models from the Helix, and not the amp/cab/mic/IR capabilities.
It does have a BDDI model as an effect, but would that mean it was technically a preamp as well?
Is the B7K a preamp or a distortion/OD box?
Anyway, my point was that the HX FX doesn't have the same preamp capabilities of the HX Stomp/Stomp XL/LT/Floor/Rack or POD Go.