[dougbrad81]

hi,
i'm still a newbie in the world of hifi. i can't seem to figure out what a DAC is supposed to do. the common one i see around the board mention is ART dio. from what i gather, you plug this into the optical out of a cd player. what does it do? can you still use a head amp? from i gather it improve sound quality. can it be used for minidisc units? thanks for any help in explaining the subject.

 

[chefbeldar]

HI-

Here's my stab at the definition of a DAC.
Digital to Analogue Converter. It take a digital signal either optical or coax and converts it into an analogue signal you can hear through your headphones or speakers. If your minidisc player has optical out you can use a DAC otherwise you'll need a CD player/DVD player that has a digital out.

Hope this helps clarify!
Chefbeldar

 

[dhwilkin]

chefbeldar is correct. Also, keep in mind all cdps/dvdps/mini-discs/etc... have two main parts: Transport and DAC. The transport is the part that holds the disc and reads the information off of it, typically consists of the disc tray and the laser. The DAC takes the digital information read by the transport and converts it into an analog signal, which is typically passed on to some type of amplifier. When people specifically refer to DACs, they usually mean an external DAC, meaning a separate piece of equipment from the cdp/dvdp/etc.... In this case, you have a normal cdp/dvdp/etc... whose only job is to act as a transport. You hook a digital cable (coaxial or optical, depending on what's available, usually coaxial) between it and an external DAC, like a DI/O. The DAC is hooked up w/ analog cables to some type of amp.

 

[dougbrad81]

thanks for the info. pretty much understand it now. so the purpose of buying an external DAC is to make for systems that might have a weak DAC? what are good affordable DAC's on the market?

 

[Hirsch]

Quote:

Originally posted by dougbrad81 what are good affordable DAC's on the market?

The most affordable quality DAC around is the ART DI/O (somebody had to say it

)

If you do a search, you'll turn up a lot of information. Another good place to look is the Digital Drive Forum at www.audioasylum.com You'll find out more than you ever wanted to know...

 

[Pace]

Quote:

Originally posted by chefbeldar ...Digital Audio Converter...

Otherwise I'm with you on that one, but I've always been under the impression that DAC stands for "Digital to Analog Converter"...

 

[chefbeldar]

Oops

made a lil booboo there thanks for pointing that out !!

 

[ixeo]

a noob question if i may..

if the source has analog outputs to the amp and then to the headphones..

why would you need the DAC?

wouldn't that be redundant? the headphones, afterall, are analog.

for example a CDP that has analog out, coax, optical even..you can just use the analog out, no? whats the difference?

 

[jpelg]

The DAC is built into your CD player. The digital signal is converted before it gets to the analog RCA-outs.

If your player also has a coax, and/or optical digital output (most full-sized players do), then this puts out a digital signal, which can be sent to a standalone DAC unit of your chosing, and then pass that onto an amp. In such a configuration, we say that the CD player is acting as a "transport" only.

To slightly complicate matters, some high-end manufacturers make dedicated transports - CD players without built-in DAC's - specifically for use with external DAC units.

Just more choices and options.

 

[DanT]

Quote:

Originally posted by ixeo a noob question if i may.. if the source has analog outputs to the amp and then to the headphones.. why would you need the DAC? wouldn't that be redundant? the headphones, afterall, are analog. for example a CDP that has analog out, coax, optical even..you can just use the analog out, no? whats the difference?

It depend on the quality of the DAC. For example if you buy a cheep portable cd-player the designer will put inside the cd-player a cheep DAC so they can sell you a non-expensive cd-player. If you want better quality you have a few choice you can either go and buy a new high end cd-player and use it. Or buy a high quality external DAC and use the old CD-player as transport(as long as it has digital out. And there is also the quality of the transport to take into account). If you go into high end gear you can buy cd-transport without DAC that have only digital out.

 

[markl]

Quote:

a noob question if i may.. if the source has analog outputs to the amp and then to the headphones.. why would you need the DAC? wouldn't that be redundant? the headphones, afterall, are analog.

All CDPs have DACs in them. A $150 CDP is not going to have as good a digital section as a $15,000 player. The point of adding an outboard DAC to your low-end CD player is the gamble that the DAC you are adding has sound superior to the internal DACs in your player. This begs the question, why not just buy a better CD player that will have an inherent DAC set that is superior to your current low-end CDP? The gamble is that for the price of the outboard DAC, you can get better sound than you could by spending the same amount on a whole new CD player. The thinking is that with the CD player, I'm paying for all these other devices/components that I don't have to pay for with a new DAC. Therefore, I'm gambling that an equally priced DAC will have greater value than an equally priced brand new CD player.

The problem is, the DAC section is not all there is to a CD player. There's the transport, analog section and power supply as well. There's the question of whether your low-end CDP can make for a good transport for your spiffy new outboard DAC. You might be sticking a very high-quality DAC on a very poor transport, potentially negating the advantage of adding the better DAC in the first place. It's possible that a brand new CDP at the same price of the outboard DAC has a better transport section, but maybe not as good a DAC and analog sections, therebby making it a wash between the two, with the new CDP performing roughly as good as the low-end CDP + DAC.

See, it's all very simple!

 

[ixeo]

so is it safe to say that... transports make no difference to the audio quality *unless the cd reader/player is that bad of a quality that it reads cd inaccurately* and the difference of cd players is the DAC?

since digital signals are just that, 0s and 1s. so player A and player B is the same, except for the DAC

thus when purchasing a CDP the DAC will decide whether it is a good source or not?

 

[markl]

No, transport quality is crucial. Do a search on "jitter". (Also, it's not about ones and zeroes, you aren't literally sending little ones and zeroes through your coax digital out

, it's a signal that is either "on" or "off".)

Also, the DAC chipset is only one component that is important. There's the clock, the power supply, and maybe most important the analog output section. There's only a handful of DAC chip makers, all CD manufacturers source from the same group. What separates a $15000 player from a $150 is not so much the DAC chipset itself, but the transport, the power supply, and analog output sections.

 

[kugino]

Quote:

Originally posted by markl No, transport quality is crucial. Do a search on "jitter". (Also, it's not about ones and zeroes, you aren't literally sending little ones and zeroes through your coax digital out , it's a signal that is either "on" or "off".) Also, the DAC chipset is only one component that is important. There's the clock, the power supply, and maybe most important the analog output section. There's only a handful of DAC chip makers, all CD manufacturers source from the same group. What separates a $15000 player from a $150 is not so much the DAC chipset itself, but the transport, the power supply, and analog output sections.

yes, markl is right about this. although DAC chips DO matter, most companies use the same chips in their systems. but it's not just the transport that incorporates jitter...the digital ouput (coax or toslink), cables, wiring, etc. all incorporate jitter into the system.