Sent my 840C in for repair, Dec 2009. I asked Audio Plus Serv. rep (North America) if the 840C had any design upgrades since my model was manufactured. He said they use better capacitors in the power supply now, which my player did not have. He said everything else has stayed the same since the player was first introduced. He said they install these power supply caps on any 840Cs returned for repair, normal practice. So evidently I have these new capacitors now installed. Sounds great.