I use upsample with the digital input from my Yamaha because I prefer the 990's DAC to the Yamaha's DAC (especially with the upsampling tossed into the mix). I've also experimented a bit with stereo analog set to bypass, which provides a pure analog signal path, which is how I determined my preference for the digital signal path. As for using the 7.1 Direct input, remember that the 990 converts the 7.1 analog input to digital and applies bass management if speakers are set to "small", so the pure output from your Pioneer is not necessarily as pure as you're thinking - if you like the 79AVi's DAC's, you might try running stereo analog outputs to the CD input and setting that input up as bypass mode.