What Is a DAC and Why Do You Need One?

What Is a DAC and Why Do You Need One?

What is a DAC?

If you’ve dipped your toes into the audiophile world, you’ve probably seen the term, “DAC” referenced in countless articles and online forums. Why? In short, a DAC can make your music sound better. But what is a DAC, and how does it work?

Simply put, DAC stands for “digital to audio converter.” You may be surprised to discover that you already use DACs all the time. For example, your phone has a DAC, as does your computer or any other digital device that emits sound. DACs are necessary because our ears can’t read digits. Rather, a digital signal must be converted into analogue form, which we hear as sound waves.

Why do you need a DAC?

If all our devices already have DACs, why do we need to buy more? Well, at the risk of oversimplifying the technology, some DACs are more effective at converting a digital signal into analogue waveform than others. For instance, your iPhone dongle offers up to 24-bit/48kHz resolution, which is technically hi-res quality. But if you’re a budding audiophile looking for the most premium sound quality from your streaming service or music files, you’re going to want an external DAC that can translate a higher bit depth/sample rate. For example, a Tidal file that’s 24-bit/192kHz FLAC (lossless) goes beyond what your iPhone dongle can deliver. So, before we move onto choosing the right DAC, it may be helpful to know what all this bit and sample rate stuff is about.

A Quick Hi-Res Rundown

Although there are a few different types of high-resolution technology, the most common one is Pulse Code Modulation (PCM). And for the purposes of this explanation, we’ll stick to the basics. PCM measures the amplitude of an analogue signal at even intervals. Bit depth determines how accurate these intervals are. Meanwhile, the speed at which these intervals are measured is called the “sample rate.” In theory, the higher the bit depth, the more precisely the amplitude of a soundwave is measured. In the same way, the faster the sample rate, the more “snapshots” we get of the audio signal. Yes, bigger is better in this case; higher bit depths and faster sample rates translate into better sound resolution. That was probably as boring for you to read as it was for me to write. But the point is that DACs have the potential deliver all the bits and kHz your precious ears could desire. Within reason. Hi-Res sound nowadays starts at 24-bit/96 kHz but can go all the way up to figures like 32-bit/192 kHz if you want to get obscene. Now, let’s get to the fun part.

Types of DACs

Depending on how and where you plan to listen to your music, you’ll want to consider which type of DAC is most suitable for you. Are you sitting at a desk, or are you listening to tunes on the go? And what about the amplifier? So, let’s look at some of the basic DAC features and applications.

Portable DAC/Amps

When it comes to headphones especially, the most common DACs are those that have amplifiers already built in. DAC/Amps are especially useful if you’re looking for a portable, all-in-one solution for your headphones or IEMs.

DACs like the iFi xDSD Gryphon DAC/Amp, featured below, can fit into your pocket, but still offers a surprising amount of power and numerous features. A key feature is its Bluetooth capability, which allows you to bypass any cable connection to your phone or computer. You can simply plug your headphone into the DAC and have a wire-free connection to your mobile or desktop device.

iFi audio xDSD Gryphon Portable Bluetooth DAC and Headphone Amp
iFi audio xDSD Gryphon Portable Bluetooth DAC and Headphone Amp

The DAC shown below, again from iFi Audio, is an example of a DAC/amp dongle. This is probably the most ideal option for those who want to listen to Hi-Res on the go. It may not be enough to power a high impedance headphone, but it’s perfect for driving your fancy earbuds or IEMs.

iFi audio GO link USB DAC and Headphone Amp
iFi audio GO link USB DAC and Headphone Amp

Desktop DAC/Amps

If you’re looking to power headphones that are harder to drive (or even passive speakers), you may want to consider a more powerful desktop model, like the one below.

FiiO K11 Desktop USB DAC and Headphone Amplifier
FiiO K11 Desktop USB DAC and Headphone Amplifier

DACs without an Amplifier

For audiophiles who love to tinker around with various DAC and amplifier combinations, a straight DAC will give you the flexibility to customize your setup. Alternatively, a lot of DAC/Amps allow you to bypass the amplifier and use the device as a pure DAC. This is another way you can combine a DAC with your preferred amplifier.

Do DACs Have Different Sound Characteristics?

While some DACs deliver a very neutral profile, others can enhance or reduce certain sound qualities of your headphones or speakers. For example, some DACs create a smoother sound, while others can boost the bass or brighten the higher frequencies.

What about DSD256 and MQA?

Also important to note is that not all DACs accommodate every digital format. DSD256, which is a technology that differs from PCM (and is often considered superior), or MQA rendering is not always available on every DAC product. So, for example, if you use Tidal streaming, you’ll want to make sure that your DAC can render MQA files.

Inputs and Outputs

Some other factors to consider when choosing your DAC are the inputs and outputs that the device offers. For example, if you’re planning to hook up your DAC to an old pair of bookshelf speakers, you might want to opt for a DAC with RCA outputs. Or if you’re looking for a balanced connection, you may want to consider outputs like a balanced 4.4mm or XLR. Certainly, when choosing your DAC or DAC/Amp, there are a lot of options and features to consider.

For more information about the featured DACs and their specifications, be sure to check out our iFi Audio and FiiO product pages. Or drop us a line below, and we’ll do our best to reply to your comments and questions.