Which has the better DAC; Receiver or CD Player? (1 Viewer)

Hey!

Just a question here. I have a Yamaha RX-V2200 receiver and a Yamaha CDC-685 5 disc carousel. I performed a little experiment by hooking up the player to the receiver with an optical cable AND a set of kimber cable interconnects. Basically, I wanted to A/B test the difference between the digital and analogue connections. To my surprise the digital connection sounded fuller and more musical, and had a cleaner and more vibrant top end. The difference was rather subtle but noticable. I should also mention that I performed this experiment before with cheaper RadioShack quality cables and notices a much greater difference in favour of the optical cable, but assumed that was only due to the cheapness of the analogue cables.

Anyway, now I'm wondering if the DAC in the CDC-685 simply isn't as good as the one found in the RX-V2200. I did some quick searching on the net and the best I could come up with is that the CDC-685 uses S-Bit DACs while the RX-V2200 uses 96 kHz/24-bit DACs. Other then that, I really don't know anything about their DACs and was wondering if anyone could shed some light on this.

Since I prefer the sound of the digital connection over the analogue one, I will continue to use it. My real question is, is the reason the sound quality is better with the optical connection because the CDC-685 uses inferior DACs and could I expect a much improved sound quality from a high-end CD player's DACs?

- Mike

This depends on many, many things.

First off, did you level match when you tested? (Digital connections are often "quieter" than analog due to the different levels, though this can vary from receiver to receiver).

Secondly, are you performing any bass management? If so, then the digital will likely sound better, simply because bass management is done in the digital domain. If you have an analog source connected, then the Yamaha receiver MAY be digitizing the signal in order to perform bass management (Thus another ADC/DAC conversion). Even if it is not doing bass management on the analog source, this could be the difference (Digital is bass managed -> amp load is less, bass will be improved as it's coming from the sub etc.)

Other factors could be ground noise from the analog connection (Optical has no ground connection at all (Ground == absense of light)) etc. etc.

Generally, I prefer digital connections as most receivers/speaker setups work better with bass management functioning - this means everything is digital until the DAC in the receiver (Just before the amps).

Hope this provides some insight. For what it's worth, I did a single blind test recently, and I could not tell the difference (Reliably) between the DAC in my NAD 522 player and the one in my NAD T752 receiver (I modded the 522 for the digital out). This was level matched, and everything set to large, sub off. (ie no bass management).

sounds reasonable

In addition to the analog outputs from the CD player going through an additonal ADC-DAC cycle in the receiver (unless the receiver supports a true analog pass-thru), were you using the CD Player's analog outputs without volume control?

I'm not sure about the specs on your CD player, but check to make sure the analog outputs are true LINE-OUTS and not the set of analog outputs connected to a volume control in the CD player itself (i.e. there may actually be two sets of analog outputs).

Hey guys,

Well, no bass management going on, I set the speakers to LARGE and bass to MAIN. To make double sure I also plugged the analogue inputs to the receiver's 6 channel inputs (normally for extrernal decoders) which bypasses bass management, DSP and other gimmicks.

So what did I find? Well, the sound quality is even closer now (it seems there was something going on the way I had it set up before). The one thing I notice now is that the music is louder with the digital connection. I'm not sure how to "level match" the two sources, although if I could that would make comparing the two practicle. Right now it's hard to say which one sounds cleaner or warmer or better because the difference in volume seems to distract me from that. It's also possible that's the only difference but I am curious to see if I could determine which is the digital connection and which is the analogue connection in a blind test once the levels have been matched (assuming that's possible with this set up).

Any suggestions on how to level match?

- Mike

Get an SPL meter.

ummmm...those are useless...you need to hook up a multimeter to the speaker outlets and play some sort of a test tone (burn a 1 kHz to a disk). yeah, it's a bit of work but that's the way it's done.

Mike,

I have a Accuphase DP 70 CDP as well as the S-Bit Plus Yamaha CDX-550. To me they sound warmer than the on board 192KHz D/A on my DSP-AZ1. I am comparing this to my DVD player connected to the coaxial in of the DSP-AZ1.

The DSP-AZ1 gives more dynamic and the highs seem to be slightly more pronounced, but for day to day listening I prefer the analog sound of the Accuphase and the CDX-550. The Accuphase sounds marvelous and it is connected directly to my Yamaha MX-1000U amp and NS-1000x speakers.