Digital vs Analog output on CD players

There are two primary parts inside each of your CD players, a transport that picks up the digital signal and then a digital-to-analog converter.

When you use the digital output on either the NAD or the Rotel you're picking up the signal after it leaves the transport but before it gets to the digital-to-analog converter in those players and sending it instead to a digital-to-analog converter in your A-V receiver.

So, with your three pieces of gear you've got two choices of transports and three choices of digital-to-analog converters. If the two transports are of equal quality and none of the three digital-to-analog converters are noticeably better than the other two you're not going to hear a big difference.

The advantage of using the digital output is primarily if you're going to send the digital signal to a separate D/A converter that is audibly superior to the one that's inside the CD player.

Thanks very much. Appreciate the education on this. It's always so much better to hear this from fellow hobbyists who speak in layman's terms. I'll continue to experiment and compare the sound. One thing I noticed was that on some CD-R's, the NAD becomes a bit jittery. With the digital cable, the jitteriness seems to have lessened. Perhaps this has something to do with a faster signal since the conversion is taking place in the receiver. I read in the NAD owners manual that the digital ouptut could help minimize or eliminate jitteriness. Thanks again.

Bottom line is; which unit has the better DAC. In your player? In your receiver?
Try and see.

Actually, there is another issue that has not been discussed yet. Most A/V receivers are basically digital devices so analog signals are first converted to digital (via a ADC) for processing through the receiver and then converted to analogue (via a DAC) for output to the speakers.

Option 1: Use Digital Output from CD Player
The outputs the digital signal to the A/V Receiver which processes the signal and then uses it's DAC to convert to analogue. A total of one conversion between Analog and Digital

Option 2: Use Analogue Output from CD Player
The CD player uses it's DAC to convert to analogue. The A/V receiver then uses its ADC to convert the input back to digital, processes the digital signal (volume, dolby or any other effects), runs it through it's DAC and outputs an analogue signal to the speakers. A total of three conversions between Analog and Digital.

Consequently, with an A/V receiver, it usually doesn't matter what quality of DAC you have in your CD player since there you are almost always stuck using the DAC in the A/V receiver. You might as well minimize the conversions and just feed the digital signal directly to the A/V receiver.

The exception to this is where the A/V receiver has a pure direct (or equivalent) mode; this mode will usually handle 2 channel analog signals as analog signals and you should not have the extra conversions so you may be better off with the CD players DAC.

For further information on this subject refer to the following link:
http://wiki.slimdevices.com/index.cgi?AVReceivers

Good post and it hits home to me. I have had cd separates for years, the Cal Audio Alpha and Delta. The dealer who sold me the units recommended a certain cable and I stuck with it for a few years. He then sold me a balanced interconnect when I chose to upgrade. I'm ashamed to ay that by accident I found out that I had been sold analog interconnects for that critical connection between transport and dac. I ordered a digital cable from Signal cable and did notice a difference right away. I fumed for a few days when I thought about not having the optimum connections for years.