How does one choose a DAC?

[davebot]

I'm suddenly thinking seriously about buying an external DAC, and I stumbled upon this forum.  What a surprise: folks here seem to value reasoning and evidence and understand the placebo effect!    A lot of the posts I've read elsewhere raise red flags for me by claiming that one competent DAC sounds dramatically different than another, or by sloppy methodology (EG, no level matching in tests), or by endorsing tweaks such as green pens and ultra clarifiers and cable conditioners.    If you believe in those things, that's fine with me, but it's not where I'm coming from. 
 
My specific situation is this: I'm getting an Oppo BDP-93 blu-ray player, and I'm wondering if it would be a smart move for me to use this for CD listening instead of my trusty NAD C541i CD player.  I know there are differences in the DAC *chips*, but I suspect that the more important differences may be in the analog output circuits. I was considering the Emotiva XDA-1 (which would also add a nice remote volume control capability to my Audio Research preamp);  I thought that the Oppo + XDA-1 might be an upgrade to the NAD.  Or perhaps not.
 
So I'm wondering: How good an external DAC would I need to be an upgrade from the NAD?
 
I would like to answer this question by blind listening tests with careful level matching, with CDs of my choosing, no time pressure, comparing multiple DACs.  Yeah, right.  Barring that, I'm wondering if you kind folks might have some advice for making such a decision in a rational manner?  I'm not sure this is the right forum for such a question, but I'm not sure I want to ask it "out there", where people seem to be making such decisions more with their gut than their head.
 
Are there objective reviews or shoot-outs for DACs?  Is there evidence for concluding that differences beyond a certain price point will be audible only to dogs, or to people who haven't matched the volume levels?  
 
 
 

 

[firev1]

For the high-end DACs, I value Stereophile's reviews quite a bit. That being said, isn't the Oppo BDP-93's DAC section pretty darn good? As for equipment wise, there has been a few comparisons made on AES but I myself do not know where to find those papers. 
 
As for differences between DACs/amps, it is usually caused by placebo or possible added distortion caused by real loads(which is not supposed to happen). 
 
 

 

[davebot]

I've read that the Oppo's DAC section is excellent.  But what about the quality of the analog output section?  I can imagine that being bested by the NAD -- or by the the higher priced Oppo player ($1000 instead of $500).

 

[BlackbeardBen]

Quote:

I've read that the Oppo's DAC section is excellent.  But what about the quality of the analog output section?  I can imagine that being bested by the NAD -- or by the the higher priced Oppo player ($1000 instead of $500).

The "analog output section" is integral to the DAC design/implementation.  It's not a separate entity, like a built-in pre-amp would be.

 

[davebot]

Oh!  Looks like a learning opportunity for me.
 
I think you're saying that there is no analog output circuit separate from the DAC itself.  I thought the DAC itself was a chip, and I suspected that a chip didn't have sufficient voltage (or proper impendence matching) to feed the RCA outputs that go to the preamp.  Do they?  For example, reading about a Bryston BDA-1 External DAC, I see that its feature set includes "Discrete Class A analog output stage".  Are you saying this is all on the chip?  If that's so, I think adding an external DAC device to the Oppo is even less compelling!
 
Thanks!
 
 

 

[BlackbeardBen]

Quote:

Oh!  Looks like a learning opportunity for me.
 
I think you're saying that there is no analog output circuit separate from the DAC itself.  I thought the DAC itself was a chip, and I suspected that a chip didn't have sufficient voltage (or proper impendence matching) to feed the RCA outputs that go to the preamp.  Do they?  For example, reading about a Bryston BDA-1 External DAC, I see that its feature set includes "Discrete Class A analog output stage".  Are you saying this is all on the chip?  If that's so, I think adding an external DAC device to the Oppo is even less compelling!
 
Thanks!
 
 

Well, it's not necessarily all on chip, but if you're talking about reviews of the player's DAC as a whole rather than it chip, it would of course include the output.
 
However, as far as I am aware of (others with more knowledge can confirm/correct me here), most DAC ICs are designed to output line level voltage directly, no amplification necessary.  Since DACs deliver into very high impedance loads from preamps/receivers/amplifiers, current isn't a problem either.

 

[khaos974]

If you are looking for pure objective measured performance, the newly released Anedio D2 has it in spades, otherwise I doubt most boutique are as good as the Oppo.
Well some probably are but you won't know unless they release their measurements.

 

[davebot]

Quote:

If you are looking for pure objective measured performance, the newly released Anedio D2 has it in spades, otherwise I doubt most boutique are as good as the Oppo.
Well some probably are but you won't know unless they release their measurements.

Very cool!  Unfortunately, it's 6 x the current clearance price of the Emotiva DAC that I was considering.  And, of course, the NAD C541i and the Oppo player are both free, since they're already sitting in my living room.    This gets to my other question, which is: at what point do the improvements stop making a difference?

 

[khaos974]

Quote:

Quote:

If you are looking for pure objective measured performance, the newly released Anedio D2 has it in spades, otherwise I doubt most boutique are as good as the Oppo.
Well some probably are but you won't know unless they release their measurements.

Very cool!  Unfortunately, it's 6 x the current clearance price of the Emotiva DAC that I was considering.  And, of course, the NAD C541i and the Oppo player are both free, since they're already sitting in my living room.    This gets to my other question, which is: at what point do the improvements stop making a difference?

According to DBT data and other objective criteria, the BD-93 is already beyond audible threshold of improvements. Subjectively? Who knows?
Personally I just want a D2 for because I like technical perfection, I may hear an improvement, but I certainly wouldn't discard my brain playing tricks on me.
 
 

 

[Willakan]

My advice for choosing any DAC is to choose one with a comprehensive set of measurements from a respected brand (more for reliability/warranty purposes than anything else).
I'm assuming you want S/PDIF input-equipped models rather than USB ones?

 

[anetode]

Quote:

However, as far as I am aware of (others with more knowledge can confirm/correct me here), most DAC ICs are designed to output line level voltage directly, no amplification necessary.  Since DACs deliver into very high impedance loads from preamps/receivers/amplifiers, current isn't a problem either.

I thought that most DAC ICs need an opamp for the I/V conversion, though there are some that integrate a line driver.
 
To the OP: DACs in products from reputable companies/designers like NAD or Oppo are of comparable quality, unless maybe you listen to 24 bit files at 120db+. Best to look for a product which offers the best feature set, and the Oppo is definitely a great buy in that regard.

 

[veritas aurum]

It depends on what kind of music you listen to , the rest of the system, and what you value in reproduction. I listen to classical primarily, and value soundstage reproduction above all else as I have found that if a DAC gets that right, everything else follows as proper soundstage reproduction depends upon the proper decoding of "small sounds"-reverberation primarily. I use the Anedio D1 as I found it to be the only reasonbly! priced DAC that performed that decoding to my satisfaction. That said, my system is brutally revealing (ASL Monsoon tube monoblocks modified with teflon caps, and Paradigm Sig1v3s all tied to toghether with solid silver interconnects and speaker cable-custom made to my specs. Your results may vary depending on your system and tastes. If you lsiten to primarily studio recordings and thru less revealing speakers, you may find that spending the money on a DAC is foolish. Regards

 

[JRG1990]

The dac's in the nad and oppo should be good enough that there completly transparent, most dac chips are transperant, there might actually be auidiable differences between some output stages especially with some discrete designs the compenents need to be perfectly matched and the circuit requires more effort to get right also a discrete design might output alot more than the standard 2vrms and cause other equipment in your chain to distort, other badly designed compents like the audio gd discrete op amps could cause audiable differences, some manufactures might even purposely add disortion or something to make there dac sound like tubes or give a coloured sound more likely its the higher end manufactures do this, id just be cautious of discrete or non feeback back etc dacs unless there backed up with measurements a basic analog output stage with an op-amp circuit is easyer and cheaper to get right even $20 dacs can get this right.

 

[liamstrain]

For me it's a matrix of features and outputs versus price. 
 
For instance:
I want a decent USB transport, coax in, and the option of balanced and standard analog outputs from the DAC. I have $500 to spend. 
 
At that price point, most all chip configurations are going to be pretty comparable from a technical standpoint (and almost all *should* be pretty sonically transparent). So it's a matter of finding one that is well built (good engineering, and power source noise isolation), that offers what I need. 
 
Other than that, its down to aesthetics and reputation. 

 

[NinjaSquirt]

Quote:

For me it's a matrix of features and outputs versus price. 
 
For instance:
I want a decent USB transport, coax in, and the option of balanced and standard analog outputs from the DAC. I have $500 to spend. 
 
At that price point, most all chip configurations are going to be pretty comparable from a technical standpoint (and almost all *should* be pretty sonically transparent). So it's a matter of finding one that is well built (good engineering, and power source noise isolation), that offers what I need. 
 
Other than that, its down to aesthetics and reputation. 

Cambridge Audio DacMagic, about $500, good USB, coax, balanced out and RCA out. Looks out. Three filters, a source selector, and an on/off button? What else could you ask for?