Are DACs really different?
Feb 13, 2014 at 1:59 AM Thread Starter Post #1 of 18

TsukiNick

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Unless they are designed to color the sound do DACs function the same? I'd like to see some recordings from different DACs from different price ranges and see some scientific support of difference.
 
Feb 13, 2014 at 5:47 AM Post #3 of 18
Oh I don't really have any separate DACs other than the FiiO E18 if that really counts, I won't really put out the money for a DAC unless I see some compelling evidence of better output in some way.
 
Feb 13, 2014 at 9:06 AM Post #4 of 18
If you can hear big diference between your realtek sound card and your Fiio E18 it means that dacs are different. Compelling evidence would involve you walking to a store to audition a better DAC.
 
Feb 13, 2014 at 12:35 PM Post #5 of 18
Properly implemented differences between each DAC chip from another is smaller than most think it is. When there are huge differences it's usually in the output stage - some are either inadequate or deliberately made to add color to the sound, like choosing a Sun or Moon over Earth HDAM.
 
Even price isn't a good indicator. I've tried a bunch of CDPs* and I still prefer the internal USB DAC of my amp, which is built around the PCM2702 - in other DACs it is only used as a USB receiver. Cambridge 651C and 340C(I think) had the bass drum in front of the vocals; Marantz CD5004 and to a lesser extent the NAD C545 had the drums going around my head (not an issue with the NAD C521BEE); Rega Apollo was too dark. Surprisingly I enjoyed the Cayin CDT23 and CD-50T a lot better (also the Arcam CD72), but these will cost me too much.
 
 
*imagine these as DACs, but with a CD transport instead of digital inputs, but some do have both now
 
Feb 17, 2014 at 5:13 PM Post #6 of 18
  If you can hear big diference between your realtek sound card and your Fiio E18 it means that dacs are different. Compelling evidence would involve you walking to a store to audition a better DAC.

Yet to compare my Realtek Soundcard, have had it disabled for a long time since I put in the Creative Sound Blaster Z.
 
Feb 22, 2014 at 7:21 PM Post #7 of 18
The analog output stage in a DAC can have a very large effect on the sound.
 
Feb 25, 2014 at 4:02 PM Post #8 of 18
The depth of clarity and soundstage presentation are the two variables I've noticed when comparing. The better DACs will deal with digital filter harshness and spatial ques (soundstage). Some high end units can sound dead while being technically outstanding. But the DAC chips are pretty similar. Its the USB conversion, output circuitry and power supply that makes the unit.
 
Feb 25, 2014 at 10:42 PM Post #9 of 18
Interesting article where multiple DAC options for PCs were compared.

http://www.head-fi.org/t/707288/toms-hardware-hi-fi-equipment-test#post_10307105

Note that Tom's Hardware is a respected / independent PC equipment site.
 
Feb 26, 2014 at 12:55 AM Post #10 of 18
The depth of clarity and soundstage presentation are the two variables I've noticed when comparing. The better DACs will deal with digital filter harshness and spatial ques (soundstage). Some high end units can sound dead while being technically outstanding. But the DAC chips are pretty similar. Its the USB conversion, output circuitry and power supply that makes the unit.

 
I can understand the clarity part, but the soundstage? Still, I do not have any experience comparing DACs. I have the ODAC + O2 and C5D.  These are not higher-end DACs, but they do serve their purpose well. Your comment on DAC chips and what makes a difference between DAC units, particularly its analog part, I think are right on the money. Digital needs a good, clean, well-regulated power supply. I imagine a separate regulated power supply and ground between the audio and digital parts is a good idea. The USB conversion I understand has its pitfalls unless properly implemented. But a DAC that has been well-designed should also be transparent, in other words, genuine to the recorded material. I think if there are any differences between good DACs, it would be the analog part.
 
What do you think?
 
Bob Graham
 
Feb 26, 2014 at 6:19 AM Post #11 of 18
   
I can understand the clarity part, but the soundstage?


As a whole circuit the DAC (or CDP, which is a DAC with a transport instead of inputs) can affect the soundstage also. Check out the diagrams below - circles are percussion (ovals are bass drum), triangles are vocals, rectangles are electric guitars. These are simplified and as such I didn't include the synth, orchestra and choir. Tested with my Meier Cantate.2 and HD600 on the same day, with a spare pair of earpads (actually tested the first group first, on fresher pads).

Marantz CD5004; similar is NAD C545 but drums are moved forward a bit; Cambridge 651C and 340C(not sure, the cheapest one?) was otherwise normal though 2D, but the problem is that the bass drum is still inside my head
 

 
 
 
 
 
Meier Cantate.2 USB input, PCM2702 USB receiver used as a 16/44 DAC - notice how the smaller soundstage is at least coherent as to each instrument's placement relative to each other; similarly, Arcam CD72 has a wider stage (everything pushed back and out); Cayin CD50T slightly deeper but tonally a little "sweeter" in the midrange; Rega Apollo has similar soundstage but tonally very dark, well beyond just "smooth"

 
Surprising how some entry level CDPs sound that much worse compared to a cheap USB DAC built into a (really good) amp, which also is surprisingly close to some expensive CDPs, save for one that does well (or rather, normally) with the soundstage but failed on the tonality.
 
Feb 28, 2014 at 9:37 PM Post #12 of 18
quick question...
i notice that some DACs have digital out. 
What is the purpose of this ?
I thought the purpose of DACs were to change digital in to analogue out, so what's the point of digital in to digital out ?
 
Feb 28, 2014 at 11:58 PM Post #13 of 18
  quick question...
i notice that some DACs have digital out. 
What is the purpose of this ?
I thought the purpose of DACs were to change digital in to analogue out, so what's the point of digital in to digital out ?

 
Some DACs have that to convert a USB input signal to SPDIF coaxial. Basically if you have an existing speaker system with its own DAC you can hook up the computer to that using SPDIF, then the USB DAC's analogue output goes into a headphone amp. Or you just use the first one. Either way you get options.
 
Mar 1, 2014 at 12:16 AM Post #14 of 18
   
Some DACs have that to convert a USB input signal to SPDIF coaxial. Basically if you have an existing speaker system with its own DAC you can hook up the computer to that using SPDIF, then the USB DAC's analogue output goes into a headphone amp. Or you just use the first one. Either way you get options.

Thank you for the explanation
 
Mar 3, 2014 at 12:19 PM Post #15 of 18
I can understand the clarity part, but the soundstage? Still, I do not have any experience comparing DACs. I have the ODAC + O2 and C5D.  These are not higher-end DACs, but they do serve their purpose well. Your comment on DAC chips and what makes a difference between DAC units, particularly its analog part, I think are right on the money. Digital needs a good, clean, well-regulated power supply. I imagine a separate regulated power supply and ground between the audio and digital parts is a good idea. The USB conversion I understand has its pitfalls unless properly implemented. But a DAC that has been well-designed should also be transparent, in other words, genuine to the recorded material. I think if there are any differences between good DACs, it would be the analog part.

What do you think?
Bob Graham
Oh, it's probably the most variable of the equation. But I also think the USB conversion has something more to add. The USB to I2S method of converting seems to have more success at resolution and soundstage presentation. I think once the industry makes a protocol for this, our digital heads will become closer to vinyl. Right now, we have tinkerers making stunning results using I2S direct to the DAC.
 

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