Depending on what player you were considering, you could find youself in a scenario where using the 5.1 output could be beneficial sonically - a Denon 2910 or better could have better DAC's than your Yamaha, although it will come at the expense of any 6.1/7.1 processing (rear surround speakers will go unused). Of course, at that point you're spending more than you were probably thinking of for the player (the 2910 lists for $740, which is more than a Model 970 and two-thirds the cost of a Model 990). Your best bet is to upgrade the processor.