How Can Two DACs Sound Different?

[Jim Naseum]

I see posts describing that one DAC sounds different than another. What? How can that possibly be?

If they do, then surely all digital products like CD players must also sound different. If so, it means digital is not an accurate medium, right? If not accurate, how can people say it is better than records?? You can't have it both ways..... Or can you?

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[paul79]

Yes, DAC's absolutely sound different from one another... Just like vinyl rigs. FE, a $5000 vinyl rig sounds different compared to a $50,000 vinyl rig.

 

The more expensive DAC's give much more transparency, dynamics, etc... DAC's are very good anymore, and I would go as far as saying, a $5K DAC could compete with a $5K vinyl rig.

 

Now, say you are comparing a top flight vinyl rig to a top flight DAC.... The vinyl rig will be better in this "endgame", but not by much.

[joessportster]

Dacs are like any other audio product, topology, parts,& implementation,  make all the difference in the world in the SQ, this fact has nothing to do with the digital file so while some may say digital =perfect reproduction I figure they are speaking about the file and not the reproduced sound coming from the speakers.

 

NO SOUND REPRODUCTION is perfect every piece analog, digital, tubes, SS, Horns, Direct radiating all have strengths and weakness

[joessportster]

Yes, DAC's absolutely sound different from one another... Just like vinyl rigs. FE, a $5000 vinyl rig sounds different compared to a $50,000 vinyl rig.

 

The more expensive DAC's give much more transparency, dynamics, etc... DAC's are very good anymore, and I would go as far as saying, a $5K DAC could compete with a $5K vinyl rig.

 

Now, say you are comparing a top flight vinyl rig to a top flight DAC.... The vinyl rig will be better in this "endgame", but not by much.

Not so sure you can place a $$$ amount that would account for a DAC being top flight,  Most of that 5g is asthetics

[Jim Naseum]

If the more expensive ones are better, it must be a result of the parts. If so, it would be simple to just say, "use these parts and you have the best DAC, the most accurate DAC."

But that's not what you see happening. You see guys saying, this $100 one sounds better than home $1000 one. And things like that.

More money= higher accuracy? Sounds very fishy. Parts have specifications that are very simple to compare. Don't they?

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Edited September 10, 2015 by jo56steph74

[muel]

You can't always assign $$ but most of the time quality costs more.

There are surprises though... one of my biggest improvements lately was with the $175 USB REGEN.

 

Yeah, digital is accurate as far as the 0s and 1s representing what they are the same every time.  It is all about the DELIVERY and conversion of that data over time to our ears.  You can talk about parts but in the end it is about all the parts together as a whole system and how well does it deliver without screwing things up.

[Jim Naseum]

No offense, but that doesn't make sense. Only certain operations are performed to convert 1s and 0s to an analog signal. It either converts or it doesn't, based on the number of bits and bit rate. Right? It's a mathematical process. 2+5=7 no matter what brand of calculator I use.

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[Jim Naseum]

There must be a measurement that explains why DAC1 sounds different from DAC2. Since it is only math.

My $2 calculator might be slower at square root than my expensive calculator, but that difference is a simple measurement that can be done. The square root of 9000 can't be better on one calculator than another, except by some specific measure, which anyone can discover with a few instruments. Such as speed, or digits of resolve.

Of I recall, people hated the magic flooby dust of analog audio. They liked that digital had no magic. But now, we are back to putting magic in digital!!!! Lol!!

Edited September 10, 2015 by jo56steph74

[muel]

Sometimes we call what we don't understand "magic."   

[Chris A]

Try reading on this thread: http://www.head-fi.org/t/566866/does-a-dac-make-a-giant-difference

 

I believe that there are many inaccuracies in this thread, including decision bias linked to perceived listening differences that were not ABX tested but that correlate instead to the perceived price of the device.

 

There must be a measurement that explains why DAC1 sounds different from DAC2. Since it is only math.

 

The real issue is  that a DAC is more of an analog device than a digital device, and many people forget that the DAC must have good analog output electronics.  The following is from Wikipedia:

 

DAC performance

DACs are very important to system performance. The most important characteristics of these devices are:

 

Resolution
The number of possible output levels the DAC is designed to reproduce. This is usually stated as the number of bits it uses, which is the base two logarithm of the number of levels. For instance a 1 bit DAC is designed to reproduce 2 (2¹) levels while an 8 bit DAC is designed for 256 (2⁸) levels. Resolution is related to the effective number of bits which is a measurement of the actual resolution attained by the DAC. Resolution determines color depth in video applications and audio bit depth in audio applications.

Maximum sampling rate
A measurement of the maximum speed at which the DACs circuitry can operate and still produce the correct output. As stated in the Nyquist–Shannon sampling theorem defines a relationship between the sampling frequency and bandwidth of the sampled signal.

Monotonicity
The ability of a DAC's analog output to move only in the direction that the digital input moves (i.e., if the input increases, the output doesn't dip before asserting the correct output.) This characteristic is very important for DACs used as a low frequency signal source or as a digitally programmable trim element.

Total harmonic distortion and noise (THD+N)
A measurement of the distortion and noise introduced to the signal by the DAC. It is expressed as a percentage of the total power of unwanted harmonic distortion and noise that accompany the desired signal. This is a very important DAC characteristic for dynamic and small signal DAC applications.

Dynamic range
A measurement of the difference between the largest and smallest signals the DAC can reproduce expressed in decibels. This is usually related to resolution and noise floor.

Other measurements, such as phase distortion and jitter, can also be very important for some applications, some of which (e.g. wireless data transmission, composite video) may even rely on accurate production of phase-adjusted signals.
 

Linear PCM audio sampling usually works on the basis of each bit of resolution being equivalent to 6 decibels of amplitude (a 2x increase in volume or precision).
 

Non-linear PCM encodings (A-law / μ-law, ADPCM, NICAM) attempt to improve their effective dynamic ranges by a variety of methods - logarithmic step sizes between the output signal strengths represented by each data bit (trading greater quantization distortion of loud signals for better performance of quiet signals)

 

DAC figures of merit

• Static performance:
  • Differential nonlinearity (DNL) shows how much two adjacent code analog values deviate from the ideal 1 LSB step.^[2]
  • Integral nonlinearity (INL) shows how much the DAC transfer characteristic deviates from an ideal one. That is, the ideal characteristic is usually a straight line; INL shows how much the actual voltage at a given code value differs from that line, in LSBs (1 LSB steps).
  • Gain
  • Offset
  • Noise is ultimately limited by the thermal noise generated by passive components such as resistors. For audio applications and in room temperatures, such noise is usually a little less than 1 μV (microvolt) of white noise. This limits performance to less than 20~21 bits even in 24-bit DACs.
• Frequency domain performance
  • Spurious-free dynamic range (SFDR) indicates in dB the ratio between the powers of the converted main signal and the greatest undesired spur.
  • Signal-to-noise and distortion ratio (SNDR) indicates in dB the ratio between the powers of the converted main signal and the sum of the noise and the generated harmonic spurs
  • i-th harmonic distortion (HDi) indicates the power of the i-th harmonic of the converted main signal
  • Total harmonic distortion (THD) is the sum of the powers of all HDi
  • If the maximum DNL error is less than 1 LSB, then the D/A converter is guaranteed to be monotonic. However, many monotonic converters may have a maximum DNL greater than 1 LSB.
• Time domain performance:
  • Glitch impulse area (glitch energy)
  • Response uncertainty
  • Time nonlinearity (TNL)

 

I believe that a lot of people obsess over DACs when they should be worried about other things--like

 

1) room acoustics and acoustic treatments,

2) placement of loudspeakers within the room and any nearfield objects in the way of the speakers - especially between the loudspeakers and the path to the listeners (including coffee tables, etc.), and

3) the performance characteristics of the loudspeakers themselves (including analog or digital crossover performance)--

 

There is far more variation in performance found in those things than in DACs.  That's not an opinion-that's fact.

 

Remember also that video DACs perform their duties at greater than 100x higher data rates and a couple of orders of magnitude more dynamic range than do audio DACs and human vision is a VERY discerning instrument compared to the human hearing system: any discrepancies in video DAC performance is quite visible.

 

Chris

Edited September 10, 2015 by Chris A

[Jim Naseum]

Sometimes we call what we don't understand "magic."   

 

Right! 

 

Yeah, that's kinda what I was getting at. Digital hasn't eliminated the audiphile magic at all. You could take the commentary from a 1975 review of tube amps, and apply it to a review of 2015 DACs, and they would both have the same magic talk. 

 

And yet......

Many people are trying to pose that digital is somehow surpassed old vinyl records. How can that be possible when both are magic systems? Funny, isn't it? Well, I thought so! Nothing much changes in audio. We are using 1948 speakers in 2015. And yet claiming something is better. Whoa! LOL! 

 

I see lotsa banter about a speaker being accurate. Sounds gooduntil you look at the frequency chart or the impulse chart. Do the Rocky Mountains look like a straight line? (maybe if viewed from the moon!) LOL Every speaker I ever looked at the chart is wildly INACCURATE! but they are called accurate! I never got that. When you look around at these graphs, it seems the best graphs come from little tiny "studio monitors" with little woofers and tweets. But in homes, you see massive gargantuan behemoths of speakers many times the size of studio monitors and then referred to as accurate. Nothing at all bad about this, but it makes me wonder if in the end of the day, the axctual only thing that is being said at all about any gear is this: "I like the sounds this one makes better than that one!"  There's no real science involved, right?

[Jim Naseum]

The real issue is  that a DAC is more of an analog device than a digital device, and many people forget that the DAC must have good analog output electronics.

--------------------------------------------------

 

Ahhhh. That certainly explains a lot. Any of the digital parts in a DAC can be rationally examined against specific measures, but the analog parts rule the day and determine the final perceived quality! Put simpler, we never escaped the magic of analog! LOL! I think the implication unless I missed the point is that the digital parts can be picked off a spec sheet by any engineer and tested to be as stated, but that the analog stuff which actually determines the sound will be subject to all the mystery of capacitors and wires and weird flooby dust, just as it always has been. 

 

so the difference from a $500 dac and a $5000 DAC is probably in the analog, since digital chips don't cost very much? Just a guess. 

[mark1101]

The difference between a $500 DAC and a $5000 DAC is not $4500 of electronics.  It's a lot less of a difference than that.

[joessportster]

"I believe that a lot of people obsess over DACs when they should be worried about other things--like

 

1) room acoustics and acoustic treatments,

2) placement of loudspeakers within the room and any nearfield objects in the way of the speakers - especially between the loudspeakers and the path to the listeners (including coffee tables, etc.), and

3) the performance characteristics of the loudspeakers themselves (including analog or digital crossover performance)--

 

There is far more variation in performance found in those things than in DACs.  That's not an opinion-that's fact.

 

Chris"

 

A fact based on What ?? I use Headphones and there are substantial differences between some dacs I have heard,  1 & 2  (above) would have zero bearing in my situation.

Edited September 10, 2015 by joessportster

[dtel]

I don't know but I would guess it's differences in the quality of parts and how there used. Somewhat like whole systems, some parts just seem to sound better matched with certain other parts, heard it called synergy before ?

 

It always seem to be both in digital and analog, some combinations just seem to sound better, and the combinations are almost limitless, it would be nice if it was just magic dust.

 

I don't know either, just a guess .

[joessportster]

The difference between a $500 DAC and a $5000 DAC is not $4500 of electronics.  It's a lot less of a difference than that.

Asthetics and name brand, you will for example see dacs that cost thousands using a sabre XXXX and amps costing only a few hundred using the exact same chip set  (a lot of what you are paying for is pretty box and a name)

[MyOwn]

 

"I believe that a lot of people obsess over DACs when they should be worried about other things--like

 

1) room acoustics and acoustic treatments,

2) placement of loudspeakers within the room and any nearfield objects in the way of the speakers - especially between the loudspeakers and the path to the listeners (including coffee tables, etc.), and

3) the performance characteristics of the loudspeakers themselves (including analog or digital crossover performance)--

 

There is far more variation in performance found in those things than in DACs.  That's not an opinion-that's fact.

 

Chris"

 

A fact based on What ?? I use Headphones and there are substantial differences between some dacs I have heard,  1 & 2  (above) would have zero bearing in my situation.

 

I know for a fact that my current Wyred4Sound DAC-2 DSDse completely obliterated the Cambridge Audio DacMagic Plus I use to have. The only thing that changed was the DAC everything else remained the same.

[Chris A]

A fact based on What ?? I use Headphones and there are substantial differences between some dacs I have heard, 1 & 2 (above) would have zero bearing in my situation.

 

Pick any set of measures posted above.  Compare those for a DAC to variations in loudspeaker + room performance.  It's not even close.

 

Headphones aren't really loudspeakers, so room acoustics are not part of that equation.  I actually hate listening through headphones:they have always given me headaches--all of them. (YMMV). 

 

I would hazard a guess that the differences that you are listening to are not the DAC chiip itself, but rather the downstream electronics that everyone seems to forget about.  All those electronics are analog, and usually not part of the performance specifications that silicon-based DAC manufacturers publish.  There, when using a high input impedance device like headphones, great differences in listening performance are possible.  However, that's not an area that appeals to me for the reason given above. 

 

Chris

[Jim Naseum]

A PCM1748 DAC chip from TI costs about $17 in single qty. A good analog opamp is around $5. Very hard to imagine how you get to $1000 retail unless the case if made of gold! LOL - just kidding, I know exactly how they get there! But seriously, were all back to square one with listening to magical analog! Kinda funny when you hear all the jabbering about "digital accuracy."

 

One has to assume it is the same story on the front end of the so-called digital process. A microhpne has to feed an ANALOG section, and then a cheap ADC chip to make 1s and 0s. Once more, I bet the magic is all inside the analog? Sure, why not? the more things change, the more they stay the same!

[Jim Naseum]

I know for a fact that my current Wyred4Sound DAC-2 DSDse completely obliterated the Cambridge Audio DacMagic Plus I use to have. The only thing that changed was the DAC everything else remained the same.

 

I liked the comments about this unit:

"Enhancing the already stellar performance of our DAC-2 series, the DAC-2 DSDse includes an array of highly upgraded components: Vishay Z-Foil resistors, ultra-low noise discrete regulators, ultra-fast recovery Scottkey diodes, premium grade inductors, green OLED display and a Rhodium-plated Furutech fuse. The culmination of these enhancements is refined audio performance down to the minutest nuances."