BeeBop, I had to edit this post. I found your owners manual on the web,
it was very uninformative, I couldn't find CD replay mentioned in it at all. Further searching on the web indicates that the options you mentioned are unlikely to be available when playing back Redbook CD's, these options are movie sound track related, and pertain to the encoding format used,
Dolby Digital or DTS. When playing back movies with Dolby Digital or DTS encoded soundtracks no PCM downconversion should be used and the Bitstream option should be selected. This will put the digital signal into the DSP in the receiver that properly decodes this information for the best surround sound field generation. Not selecting the Bitstream option will usually result in the player outputing a stereo PCM signal that the receiver would have to use Dolby Prologic to recreate a surround effect from.
From the information contained in the TI PDF docs relating to the chips used in the XR25/45 it would appear that the DSP engine is bypassed when 2ch PCM information is inputed unless specifically engaged to process the signal. If the PCM data is not manipulated by the DSP ,it is then converted to PWM and amplified, then it drives the loudspeakers. no internal DtoA
conversion appears to occurr until the output of the amplifier. I hope this is a more accurate answer. Rant about Denon owners manual, and owners manuals in general not posted.
