What is a DAC? Digital-to-analogue converters explained

If you listen to music a lot, chances are that it’ll be a digital music file you’re listening to.

However, what you might not realise is that in order to hear that file, you’ll need a DAC. Digital-to-analogue converters are built into every bit of kit capable of digital sound.

You’ll find a DAC in your phone or laptop, but also your TV or games console, in CD players, as well as wireless headphones, portable music players and more, taking analogue signals and turning them into the digital signal that you hear.

But what exactly are DACs, and why do they matter? Read on to understand why they hold such importance in the audio scene.

What is a DAC?

Before we get into exactly what a DAC is and does, let’s go through a quick re-cap. Human ears aren’t capable of hearing the 0s and 1s that make up digital music; unless you’re secretly an Android (or AI), us humans can only hear analogue signals.

Not just that, but the kit through which we hear music – whatever that may be – can’t play a digital signal either; it can only receive it. In order to transmit it, that signal must be converted into an analogue soundwave first, and that is where a DAC comes into the equation.

A DAC is the middleman within the whole process, unpacking the binary information stored in the digital file so the resulting sound most accurately represents the original analogue recording.

Of course, digital files can be stored in varying levels of quality/sample rates – from 256kbps MP3 streams to 24-bit/192kHz FLAC digital downloads – and this affects the amount of information they contain.

A DAC can only work with what it’s given though, its raison d’être is to make sense of what’s provided and translate it accurately from its binary format and return it as closely as possible to the original analogue recording.

Just be aware that feeding a good-quality DAC a poor-signal quality signal can make shortcomings in that recording clearer. Our review of the Eversolo DAC-Z10 is a good example of that.

Do I need an external DAC?

Not all DACs are created equal. Although every source of digital music contains a DAC, how well it does its job can vary widely.

For example, cheaper DACs might not support more unusual file data rates and are more likely (but not always) to have lesser quality circuitry that results in timing errors, distortion and noise in the sound that’s reproduced.

Timing errors are one of the biggest issues with lesser quality DACs, which is the reason devices such as mobile phones and laptops often aren’t the best source for digital music playback. The DAC included is not always the priority, especially in cheaper handsets.

Thankfully, you can improve what you already have and bypass a poor-quality internal DAC with a better quality external one with better internal circuitry that’s focused on making audio sound as good as it can be.

In particular, dedicated hi-fi DACs can tackle timing issues thanks to better, more advanced digital clock circuitry. This means the file conversion to analogue will be tighter, cleaner and more faithful to the original recording.

What type of DAC is right for you?

While any external DAC is likely to offer improvement on the sound pushed through something more basic, this isn’t a given – and its effectiveness will vary. As ever, it’s worth doing your research before you buy.

Device compatibility is an area to take note of, especially as pretty much all mobile devices have now ditched the 3.5mm jack that were common when this article was first published many moons ago.

You can spend thousands on a DAC if you’re rocking a system worthy of that kind of cash – Chord’s top-of-the-range DAVE comes can be had for £10,500.

Equally, if your wallet isn’t quite as flush with money, there are less expensive portable DACs such as the iFi Go Link 2 (£59) which could make all the difference to your audio setup.

This is the reason it’s important to think about how you most listen to digital music. What devices do you use and what functionality do you need?

External DACs can come with a USB-C on-the-go cable, helpful for connecting to Android devices or iOS devices. For added convenience, there are DACs that can connect wirelessly to devices over Bluetooth.

Portable DACs such as the Go Link 2 don’t require any external power as they take it from your device. They keep things simple, with just a USB input and headphone jack for playback.

Spend a bit more on something like the Chord Mojo 2, and you’ll keep the portability but add in coaxial and optical inputs for extra functionality.

A unit such as the Burson Playmate 3 on the other hand, is bigger and requires external power. That makes it one for either your desktop or the hi-fi rack rather. It does offer more connectivity options such as digital or analogue audio inputs, for those with more involved setups.

Make sure these types of DACs come with a built-in headphone amp if you intend to do some private listening through a pair of headphones as not all do.

Make sure you’ve got the best possible quality

Regardless of the DAC you end up choosing, you need to start out with good source material. A low-res Spotify stream just won’t cut it.

You’ll hear optimum results with CD-quality content and above, which is best stored in FLAC, WAV or ALAC (for Apple Macs) lossless PCM formats, or alternatively DSD if you prefer that format.

Again, it’s worth noting that the likes of FLAC and PCM and relatively accessible unless we’re talking about high bit-rates and sample rates. Something more exotic, such as DSD, is not as common, but in the right set-up, it can offer excellent audio quality.

If you’re unaware of what DSD is, it’s an audio format that stands for Direct Stream Digital, and is an alternative to PCM (Pulse Code Modulation).

It differs by offering a bit depth of just one, but much higher sampling rates – DSD64 at 2.8 MHz and DSD128 at 5.6 MHz. If you’re in the DSD camp, it’s worth checking if a DAC supports it as again not all of them do. The ones that are compatible with DSD, tend to be on the expensive side.

In any case, if you enjoy listening to music in the best quality possible, you’ll be well served by adding a DAC to whatever system you have.

Do some research, read reviews, and you’ll be on your way to audio nirvana.