Replace the solid metal jumpers on the back of the NAD C320BEE that connects the Preamp OUT to Power Amp IN jacks with the Tara Labs The Missing Link or RSC Link. They are a pair of 6 inches long interconnects that costs about $35 new. They will smooth out the high frequencies, bring out more harmonics, air and ambience, take away some of the hardness overall and soften the midrange. An economic upgrade that is worthwhile.
As other have said, the biggest improvement will come from a new CD player like the Rega Planet and a good pair of interconnects.
As other have said, the biggest improvement will come from a new CD player like the Rega Planet and a good pair of interconnects.