Like hugh said there is a difference between a lossless sound and DTD/DD , but the true about why anyone change there receiver as to do with cutting on exixting wire like everything goes to the receiver and only one output to the tv , since before , me included we had a really good receiver but it was a pass-thru and in matter to enjoy some DD when need it another optical cable , multiplying that with PS3, 360 , BR , satellite/box receiver we just narrow down the amount of cables behind our sets .