What is a DAC?

[mikie]

I've seen alot of posts about DACs lately but it's not clear to me what a DAK is, what it's used for, or why I'd want to own one. Can someone enlighten me - in simple english? Am I missing something that every audio hobbiest needs to have? --Mikie

[lcaillo]

DAC = digital to analog converter. You already have several, probably, in your digital sources, such as CD players and DVD players, and perhaps in A/V recievers or Pre/Pros. Whether you need a unit that specifically does that task or not depends on whether you prefer the sound of a particular DAC over the ones in your digital devices, such as your CD player.

[Otto]

Hi Mikie,

A DAC is the device that takes the digital data and restores it into an analog audio signal that you can hear. Devices that use a digital storage medium (such as CDs, DVDs, etc.) must be converted back to analog before it makes any sense for a human to listen to them. This data is read from the meduim, potentially manipulated by the system (while the signal is still digital) and then those discrete, numerical values are translated into a fully continuous analog signal. That signal is then fed through your preamp, power amp and, finally, your speakers.

In general, a digital to analog converter must exist somewhere in your system. In a stand-alone CD player that feeds an analog signal to your preamp, the DAC is in the CD player. If you send a digital signal to your preamp (or receiver, as the case may be), the DAC is in your preamp, and it's doing the conversion.

You can also buy outboard DACs that take a digital signal in (usually via optical or coax, and sometimes AES/EBU or USB), and output an analog signal to your preamp. These range in price from <$100 to $10,000+++. The reason you might want one is for its audio sound quality. There are different things that can be done during the conversion stages that can affect the sound, which you may or may not like. One example of an implementation that will create a "different" sound is the use of vacuum tubes in the signal path.

Anyway, that's kind of the basics.

[mikie]

Thanks Otto, that helps. --Mikie

[bobgpsr]

Any AVR or Pre-Pro that has any type of digital input (coax or optical Toslink S/PDIF), HDMI audio, or iLink then it has to have DACs. One for each audio channel.