Technology has improved by leaps and bounds in those 30 years.
If you can use the Marantz as a transport, I would invest in a good DAC like an Ayre Codex or Schiit Gungnir or Yggy. Not too much money, but lots of quality performance. And, they offer updates when available.
Also, I wouldn't spend more than $2K for a DAC, as they have been improving so quickly, and that $2K can get you something that will sound as good as something more expensive.
IMHO
Bob
If you can use the Marantz as a transport, I would invest in a good DAC like an Ayre Codex or Schiit Gungnir or Yggy. Not too much money, but lots of quality performance. And, they offer updates when available.
Also, I wouldn't spend more than $2K for a DAC, as they have been improving so quickly, and that $2K can get you something that will sound as good as something more expensive.
IMHO
Bob