Do I need a DAC?

[bread29]

After doing some initial research, I came to the conclusion that I may need a DAC. I primarily listen to computer audio via Itunes converted to ALAC. I'm using a fairly new Creative Soundblaster audio card and running a Toslink cable to my Yamaha Rx-v863 receiver, powered by Emotiva UPA-5. I'm a fan of Emotiva and am interested in the XDA-1. My question is: do I actually need to purchase a DAC & if so, will it produce a noticable difference?

 

[Pyrrho]

No, you don't need a DAC. Unless something is malfunctioning, or there is some added processing aside from mere conversion, you will not hear a difference.

 

[audiofox]

The 663 and 863 both apparently have Burr Brown DACs (from a quick Google search plus a mention here on an Audioholics review), all of which have very respectable performance specs. I can't find a reference for the specific part they use, but many high end stand-alone DACs (and the majority of HT receivers) use Burr Brown DAC ICs, so you probably would not improve your system performance much, if at all, with an external DAC. In addition, if you have any multichannel hi-res files, most external DACs would be useless for playback, since most of them are two channel only, while the receiver is (usually) multichannel since it has to decode the TOSlink and/or coax SPDIF inputs from such things as DVD players, etc.

 

[TLS Guy]

After doing some initial research, I came to the conclusion that I may need a DAC. I primarily listen to computer audio via Itunes converted to ALAC. I'm using a fairly new Creative Soundblaster audio card and running a Toslink cable to my Yamaha Rx-v863 receiver, powered by Emotiva UPA-5. I'm a fan of Emotiva and am interested in the XDA-1. My question is: do I actually need to purchase a DAC & if so, will it produce a noticable difference?

If you are using compressed material from Itunes then you will not notice a difference. If you are converting compressed material to FLAC then you are wasting time and space. You only ever convert loss less audio to FLAC.

If it a professional computer work station you have then the sound card should never be in the computer case, or driven from the computer power supply. All the pros I know use an external DAC with its own power supply, out of the computer case.

 

[audiofox]

If you are using compressed material from Itunes then you will not notice a difference. If you are converting compressed material to FLAC then you are wasting time and space. You only ever convert loss less audio to FLAC.

If it a professional computer work station you have then the sound card should never be in the computer case, or driven from the computer power supply. All the pros I know use an external DAC with its own power supply, out of the computer case.

Mark, it appears Bread29 is not doing the D/A conversion at the computer but in his receiver (ie, the comment about the TOSlink between the PC and the receiver), so the issue I think he is asking about is whether or not an external DAC is an improvement over the built-in DAC(s) in his Rx (Bread, feel free to correct me if I am wrong!). I agree that one does not want to use the onboard DAC in the PC/Mac to do the D/A conversion but rather some form of external DAC, be it a dedicated converter or a receiver with acceptable quality built-in D/A capability. Since the pros that do this for a living don't have need for a HT receiver in their studio, the natural choice for them is an external DAC or audio interface, but for the home audio enthusiast, I think the most cost effective choice is using the receiver most already own rather than purchasing an external DAC that frequently has the same (or close enough) DAC chips as in many receivers. BTW, I agree with your MP3 comment-converting compressed source material to an uncompressed format is a waste of time and HD space.

 

[bread29]

I am fairly new to running computer audio through a home theater. I was basically investigating the advantages of an external DAC over what I already have in place. As far as Itunes is concerned; why do they give the option to convert to their lossless codec if it's a waste of time and HD space? I was under the impression that I was getting higher quality audio by doing that. My goal is to get just that: to get high quality audio (better than CD) from the computer. Any further suggestions or advise would be much appreciated!

 

[its phillip]

I am fairly new to running computer audio through a home theater. I was basically investigating the advantages of an external DAC over what I already have in place. As far as Itunes is concerned; why do they give the option to convert to their lossless codec if it's a waste of time and HD space? I was under the impression that I was getting higher quality audio by doing that. My goal is to get just that: to get high quality audio (better than CD) from the computer. Any further suggestions or advise would be much appreciated!

Lossless doesn't get you "better than CD quality." Lossless is simply a lossless version of the source (which is typically a cd), so it will be exactly the same as the source.

To better clarify for you what TLS Guy said: if you are converting lossy files (like mp3s or aacs) to lossless, you are getting no quality gains and are just wasting time and space. With lossy compression, you never get that data back...so a lossless version of an mp3 or whatever will sound the exact same as the mp3.

What exactly are you converting to ALAC?

 

[Pyrrho]

I am fairly new to running computer audio through a home theater. I was basically investigating the advantages of an external DAC over what I already have in place. As far as Itunes is concerned; why do they give the option to convert to their lossless codec if it's a waste of time and HD space? I was under the impression that I was getting higher quality audio by doing that. My goal is to get just that: to get high quality audio (better than CD) from the computer. Any further suggestions or advise would be much appreciated!

If you are buying lossless files, then they should sound as good as the source (normally, this will be CD quality, but you might want to investigate further for the specifics of what you are buying).

If you bought a "lossy" format, and then converted the file to a lossless format, that would not gain anything in fidelity, as the conversion cannot magically create information that is not in the file that is converted.

In other words, there appears to be a miscommunication that you are having with some of the people replying to you in this thread. You deciding to download lossless files is not you converting anything. Downloading lossless files should get you better sound than downloading "lossy" files.


Also, for 2 channel (or 1 channel) sound, there is no reason to find anything better than CD quality, as studies have shown that the CD format is transparent (as far as humans are concerned). See, for example:

http://www.bostonaudiosociety.org/bas_speaker/abx_testing2.htm

http://en.wikipedia.org/wiki/Super_Audio_CD#Audible_differences_compared_to_PCM.2FCD

http://www.audioxpress.com/magsdirx/ax/addenda/media/galo2941.pdf

http://www.bostonaudiosociety.org/explanation.htm

Although there are high resolution files that one can download that are higher resolution than CDs, it is a waste of money and file space, even though those are theoretically better. But theoretically better does not mean that it is audibly better.

 

[jinjuku]

I read the PDF from AudioXpress on the decline of SACD and I think the things they attribute to the decline of SACD are off the mark.

They listed lossy iTunes and their ilk as a major contributor to it's decline. I think it was the lack of being able to transcode SACD and put it on your iPod or similar that did SACD in. Who wants a clunky CD player on your arm whilst on the treadmill at the gym. For being really smart guys they don't 'get it'.

Thats reason #1 I NEVER purchased a SACD (but I own a decent number of DVD-A titles).

 

[AcuDefTechGuy]

Bottom line is, you don't need to buy an external DAC since the DAC in your receiver will sound the same to your ears as an external DAC.

 

[bread29]

Thanks for all the input, and I now have a somewhat clearer picture of computer audio. I was misinformed in reference to the "magical" capabilities of Itunes converting Mp3 to ALAC. I assumed that when I 'right-clicked' and hit 'convert to apple lossless', that I was getting a higher-quality product being that the bit rate increases as well as the size of the single file (sometimes 25mb! per song). I will be switching to FLAC, and sites like HDTracks. Thanks again.

 

[krzywica]

Thanks for all the input, and I now have a somewhat clearer picture of computer audio. I was misinformed in reference to the "magical" capabilities of Itunes converting Mp3 to ALAC. I assumed that when I 'right-clicked' and hit 'convert to apple lossless', that I was getting a higher-quality product being that the bit rate increases as well as the size of the single file (sometimes 25mb! per song). I will be switching to FLAC, and sites like HDTracks. Thanks again.

Correct...its basically converting dog poop into a cow pie.....larger pile, same shi..

 

[bikemig]

Is a dac ever needed?

I certainly wouldn't buy a dac if you have one in your AV receiver but an external DAC can make a difference if your system lacks one. I listened to my desktop system (audio engine N-22 amplifer and P-4) speakers for a long time before adding a dac (HRT music streamer ii) and it made a clear difference in how my music sounded. In fact, I ended up getting rid of a few ripped CDs where the SQ was simply not good enough for my now more revealing system.