There is nothing to be gained from that, unless you had a very long run of cable.

Better cables, with lower AWGs and silver soldered gold plated connectors would
theoretically improve things though.

The amp will have to do a D/A conversion and unless you paid an extra $1000 for
the electronics in it, the pre/pro in the radio is much better equipped for this job.

Bit of A/V addict here, filtered pre/pro > monoblock balanced amps > Paradigm Reference
5.1 SACD and 7.1 DTSHD-MA in my basement cave.