2-channel modes

[UFObuster]

I just want to understand what the 2-channel options that I have really do. I think I know, but I'll float the question:
...I have the RSP-1068. I playback CDs with a Denon 3910. I also have a Yamaha DVD-C750 reserved for it's 5-tray "party-pack" playback of CDs.
...The RSP-1068 gives me options: 2-channel "bypass" , 2-channel stereo (sub is present) or 2-channel PCM. I have analog cables from the Denon and optical from the Denon and Yammi.
...I'm set up for 2 channel with a separate Rotel RB-1080 to my Klipsch speakers. I also have the 'pure direct' mode off of the Denon. I'm guessing that it's a matter of which DAC is used. I'm also guessing the the 'best' 2 channel that I'll get is from the Denon 'pure direct' to the 'bypass' mode of the 1068.
I'd love to have a better technical explaination of what is going on with these options.
Thanks
Roger

[Kevin D]

When using analog inputs (DAC's in the player)

2ch stereo Rotel digitises the incoming signal, applies bass management, contour, etc; then converts it back to analog.

2ch bypass Rotel leaves the signal alone, passes it through the volumes control in analog, then out the speakers.

When using a digital connection (DAC's in the Rotel)

2ch PCM is the standard format for a digital signal, same as 2ch stereo above except it's all ready digital coming in.


Pure direct on the Denon probably just shuts off the video circuits and any bass management done inside the player. Probably just applies to the analog outputs.


Kevin D.

[UFObuster]

2 channel

Thanks Kevin...I'm not an audio engineer but I want to understand what's happening. For anyone, see if I've got this right:
1) the CD is digital.....in PCM mode.
2) the CD player has a DAC onboard.
3) pre-pros and receivers have DACs onboard

So:
1) if I take analog from the CD player and use analog bypass in the Rotel...I am using the player's DAC and subject to it for quality. No bass management etc in the Rotel. Its only as good as the CD player makes it.
2) if I take the digital signal from the CD player..ie, thru the optical cable, then I'm using Rotel's DAC to convert to analog with the option of using bass management etc in the Rotel.

Question:
Unless the CD player is a damn good one with the most excellent DAC, why would anyone use the 2 channel bypass mode? Wouldn't it make sense to use the Rote'ls internals playing back in stereo or PCM mode?

Corollary question: if you had a Rotel CD player...how would you play it thru a 1068...bypass or not?

thanks again
Roger

[Kevin D]

You got it.

As far as your questions, a lot of people do have better players or external DAC's they prefer. On the bypass mode, some people believe that any processing is altering what the artist intended or don't feel subwoofers are needed for music.

Of course if you use analog but not in the bypass mode, you'll probably get a similar sound to using a digital connection; since it's going through the Rotel's ADC's and DAC's as well.

General consensus from the forum is analog for the 1072 and digital for the 1055.

Kevin D.

[pbarata]

I've both Rotel RCD-1070 and Denon 3910 and for CD reproduction I prefer Rotel over Denon, when compared using the analog stereo outs.

Denon has a very liquid sound with very sweet highs but doesn't have the low end dynamics of Rotel. In many CDs the Denon lacks the kick and velocity of RCD-1070 with percussion instruments.

Even with SACD the low end of Denon its too much laid back/slow for my taste.