I received an email back in September about this. The internal DAC has been updated but it's tough to find info on it.
From Gary Dayton's email,
Until now, the DAC option in our integrated amps and preamps has been limited to 96 kHz / 24 bit. Our new 2018 version supports 192 kHz / 24 bit and is based on our award winning BDA-3. Like our flagship DAC, this new card features an AKM 4490 DAC chipset and the same transformer isolated S/PDIF input. Though this card has a single DAC and therefore single ended output, it gets much closer to the performance of our top-of-the-line stand alone unit than the previous version which was already much loved. Most importantly, it's the same cost as the previous DAC!