[CML86]

What is a dac? is it same as amp/headphone amp? Thanks!

 

[HiWire]

It's a digital-to-analog converter. Most CD players and MP3 players have them - it takes the digital series of 1s and 0s from your source (e.g., a Compact Disc or MP3 file) and turns them into an analog signal to drive things like an amplifier. Almost all amplified equipment (e.g. a headphone or speaker amplifier) use an analog signal.

For more on line level analog signals:

Line level - Wikipedia, the free encyclopedia

For more information on DACs:

Digital-to-analog converter - Wikipedia, the free encyclopedia

A DAC is not the same as a headphone amplifier. A lot of new products combine the 2 functions in one box because they are a popular way of upgrading your existing audio equipment, provided you have a digital audio output from your source (most commonly, an SPDIF jack - either optical or coax).

Here's an example of a DAC:

TEAC Esoteric

For example, you can take a digital signal from a DVD player or a PC soundcard and use a better DAC to improve the sound coming out... it's an easy upgrade because you get to keep your original equipment and just add one or two boxes.

Of course, you should only get a DAC if you think it will be better than whatever DAC is in your existing equipment... since getting a clean, low-jitter signal is more difficult than the mass-market producers would have you believe, the aftermarket DACs tend to be more elaborate than the chip solutions used in your average DVD or MP3 players. Usually, they'll have better specs and separate power supplies as well as improved clocks.

The device that feeds the DAC is called a transport - the really high-end audio companies produce disc players that are transport-only - that is, they don't contain a DAC themselves, but only output a digital signal to another box (usually sold by the same company). Often, you'll see people here asking whether they should use their existing equipment as a transport - this means that they are basically wondering whether their built-in DAC can be bettered by the output of a separate box.

Here's an example of a transport:

TEAC Esoteric

 

[CML86]

That's very helpful, thanks!