Not sure of A5 and D1. But NAD D3020 is one of NAD 3020 legendary amp line up. Come with a good DAC and amp, said by reviewer and seller. The speaker however so small. You can google the measurement and try imagine. I plan to get D3020 and get PSB Alpha B1 or Dali Zensor 1 speaker but Agong say no to me so I hunt cheap used hifi set. Now this is hifi zone, no more multimedia speaker.