Excellent forum everyone. This is my first post. I recently purchaded a Denon 3806 as part of a HT set up and am very happy with the unit. As I am reading the manual and playing with the settings to learn how the unit works I noticed that when I play music if I select DTS neo 6 I get a certain sound, I get a slightly different one when switching to the Dolby setting, and yet a different sound (louder also) when I press the button marked 7ch. I am confused as to why I hear something different for each setting. I also noted that the CDs I have do not indicate that they were recorded and encoded with DD or DTS so what exactly is the receiver picking up as far as a signal? I listen mainly to stuff from the mid 60's to mid 70's such as Cream, Led Zeppelin, Black Sabath, etc..Can someone please help me understand this. Thank you in advance.