The Avr-985 is 120V 60Hz input, the 2805 is 230V 50Hz. From previous replies from Denon and looking at the PDF spec sheet for both, the Tuner frequency range is slightly different for each model too. I had been told that a US tuner section would not work fullly in Europe on a 5805 (or was it 5803!!) US model. Anyway, you get the picture.