My experience with the Hypex UCD-100 modules, which have a differential input with 1.8K input resistances is that the inputs sit at a DC level, and this cannot be disturbed, so Hypex requires the input caps in order for the module to work at all.
Ended up trying shorting out the caps. No big difference - probably the basic quality of the DSP etc is not HQ enough to reveal any difference. I have abandon these amps - maybe I use them for a "party system" with 4 RC 15" midbass drivers and a pair of Dayton amt4pro...
