What are they?
A DAC is a device that turns a digital signal into an analogue one. To understand why we need it, we do need to understand a few concepts;
Sound that vibrates our ear drum is an ANALOGUE sound. When say a drum is beaten it creates a sound wave that vibrates air molecules. The sound wave consists of an amplitude and frequency. Generally the higher the amplitude the louder the sound will be. The frequency changes to create different pitches of sounds, so we can discern what the sound is.
So when a file of music file is streamed or downloaded from the internet or ripped from a CD and stored on a hard drive, it essentially involves storing a code of the music. This code is in 0’s and 1’s and is a digital code. It needs to be converted to analogue, so it can be heard, and hence why we need a DAC.
You probably would not have heard of them if you are a newbie to HiFi. They are the hidden component of pretty much all digital electronic devices from TVs, to phones and computers – anything than needs to turn digital into a sound we hear!
Relating to or using signals of information represented by a continuously variable physical quantityAnalogue
Expressed as a series of digits 0 and 1, typically represented by values of a physical quantityDigital Data
Types of DACs
There are various types of DACs from R2r ladder DACs, FPGA, or off the shelf chips from the likes of Wolfson, Burr Brown or ESS (eg Sabre). It is not essential to understand how they work because at the end of the day they can all sound very different and perform differently too.
Much of the sound qualities of DACs are not just in the converting electronics used but the implementation of the analogue electronic stages and power supplies involved. Contrary to beliefs on internet forums, it is is not possible to predict the sound qualities of a DAC based on the DAC chip it uses, simply because of these reasons.
Generally standalone DACs utilise left and right output channel connections that follow all the way through the audio chain to the speakers. They will connect to the line input connections of your pre-amplifier or integrated amplifier.