My 7 year old Sony receiver is dying, I don't quite like it from the beginning and will never buy any Sony audio products any more. I'm looking into a new receiver with 7.1 capability and without HDMI (I never connect video through receiver). Panasonic XR55S came into mind with its digial amplifier technology. The description says:"With this sleek silver receiver Panasonic has coupled the benefits of digital technology with a high-quality amplifier. Digital amplifiers are much more efficient than traditional analog amplifiers, generating less heat and taking up less space while delivering an even larger amount of clean output power. Sound quality improves with the elimination of digital-to-analog conversion when connecting a digital source device (such as a DVD player) to an analog amplifier." I noticed that the size is significantly smaller and weight is significantly lighter than the so called traditional analog receiver, but I still don't understand the mechanism and physics of what's digital and what's analog. So if digial amplifier uses a digital chip to process the signal, what does analog amplifer use? Why digital amplifier generating less heat? Could someone explains this in plain English and plain physics? Thanks a lot