True to AVA's MO, differences between the new and old DVA Digital Preamplifier DACs aren't apparent from the specs. I do see DSD 256 doesn't appear to be supported by the new DAC, unless there is a typo there.
The hybrid mono amp may differ from the previous FET-Valve stereo amp by more than just its power output rating, since that is a significantly older design. I don't see resistance ratings, hopefully 8 & 4 Ohms, maybe due to certification status.
I'm sure more info is forthcoming, either from AVA and/or reviews. Regardless, I expect the new units will sound wonderful and are not just re-named previous models.