In this article we will talk specifically about DACs, their role, types, features and selection criteria.

What is a DAC and why is it needed?


A DAC converts digital audio to analog. What is audio? In physical terms, it is mechanical vibrations in the form of analog waves that can be picked up by the human ear. Audio used to be recorded using an all-analog signal path. Audio engineers would capture sound waves directly from a microphone and record them onto magnetic tape or engraved onto vinyl as an electrical signal, from which it could then be read out using amplification. There was no need for conversion, as the same waveform was reproduced on a 1:1 scale.

This was the case until people learned to digitize an analog signal, namely, transfer it to an analog-to-digital converter (ADC), process it with a processor and convert it into binary code.

What did this mean for the world of audio? It meant that it was no longer necessary to store huge record collections of your favorite bands' albums — all that treasure, collected over the years, could now be contained on one tiny digital medium. The only thing left was to reproduce it. But the thing is, if you put binary code on a loudspeaker, nothing happens. For our ears to hear the sound, the ones and zeros need to be converted back into an analog wave. This task is taken care of by the DAC.

Built-in vs external DAC

There are two main types of digital-to-analog converters: built-in and external. The first is present in almost every modern device that can play audio: smartphones, tablets, MP3 players, computers, TVs, etc.

An external DAC is a separate device that connects to the audio source via a digital interface, such as USB, optical or coaxial, and produces an analog signal at its outputs.

When is an external DAC needed?

Often the characteristics of the built-in converter are not enough to reproduce high-quality audio. Many manufacturers save money on this component in the pursuit of sales growth in favor of compactness or cheapening their products. So if you're not happy with the way your cool new headphones or speakers play when paired with your smartphone or MP3 player, don't be disheartened, it may not be their problem at all.

An external DAC can help if you want:

  • improve the sound quality on your device;
  • expand the functionality of your audio source — add additional inputs or outputs, support for new formats or standards, the ability to connect to other devices.
  • get more control over audio — adjust various parameters such as volume, tonal balance, filters, operating modes, etc.

Different models of external DACs (and there are many of them) offer different features, so it is important to choose the most appropriate one for your needs. Let's find out what options the market offers.

DAC types

Let's mention at once that there is no clear division by DAC types, the only difference is in the case in which it is installed (the bigger it is, the more possibilities the device has), and whether this case has an amplifier. Based on this, digital-to-analog converters can be conditionally divided into three main types:

Portable DAC

A portable DAC is a compact device, usually the size of a flash drive or slightly larger. Ideal for those who want to improve the audio of their mobile devices, as well as for those who often listen to music in different places or on the move.

Typically powered by a built-in battery or an audio source, connected directly or via cable to the USB connector of a mobile device, has one or more inputs and outputs, and may have a built-in headphone amplifier. In the latter case, it is usually customary to talk about portable amplifiers, which can be used in conjunction with high-quality headphones.

A great example of an inexpensive portable DAC with a headphone amplifier is the M-AUDIO Micro DAC with analog volume control. The model is distinguished by a very clear, assertive, but not distorted audio, which is pleasant to listen to. The metal case and optical digital output are a nice bonus to the affordable price.

Portable Amplifiers

Stationary DAC

A stationary or desktop digital-to-analog converter differs from its portable counterpart in terms of larger size, the need for a network connection, multiple inputs and outputs, support for high audio quality, diverse settings, filters, and operating modes. When integrated into an audio system, these DACs significantly enhance sound detail, volume, and acoustic object localization. They can unveil previously elusive details even in familiar tracks. Stationary DACs encompass a broad range of devices, with costs escalating alongside their capabilities. These include DACs with or without amplifiers and stationary headphone amplifiers.

A good example of a stationary DAC is the Teac UD-505. The Bluetooth-enabled unit, with remote control and large, informative display, delivers crisp timing, smooth dynamics and plenty of room in a well-constructed stereo sound field. This DAC will definitely make you want to listen to all your songs again. You'll be surprised how good your music can sound, even from streaming services.

Stationary headphone amplifiers

Audio interface

The audio interface is designed for professional audio content creation rather than casual music listening. It facilitates the connection of musical instruments and microphones to a computer or mobile device, allowing processing through specialized programmes. Acting as both a DAC and an ADC, the audio interface converts analog audio to digital and vice versa. Essentially, it functions like an external sound card but with enhanced connectivity and sound processing capabilities. This device is ideal for recording, editing, and playing back audio files, enabling interference-free live music recording, podcast creation, streaming, and audio broadcasts.

The audio interface can be either portable or stationary. The most popular example of the first is IK Multimedia iRig HD, the second is the Tacsam brand model.

General tips for choosing a DAC

Consider it a fundamental principle that a DAC enables you to experience sound at the quality captured in the source file. If the original track is of low quality, the DAC cannot magically enhance it. Therefore, prioritize uncompressed formats like WAV, AIFF, RAW, DSD, DXD, or lossless formats such as FLAC, MQA, WavPack, etc., for optimal audio quality.

Not all DACs work with headphones. If you are going to connect headphones, make sure that the model you choose has a built-in amplifier.

The more inputs and outputs a DAC has, the more options you will have to connect different devices. Using a coaxial or optical cable, for example, you can connect your favorite DVD player, and connect more advanced and modern equipment through the XLR connector. The presence of a USB connector allows you to connect the DAC to a computer or USB drive, and the AUX to a smartphone or MP3 player.

Those who prefer to listen to wireless audio should consider DACs with Bluetooth and Wi-Fi wireless modules. To listen to content from the network via cable, you need models with an Ethernet connector.

Characteristics of a good DAC

Having considered our advice and determined the type of DAC you require, it's crucial not to make an error in selecting a specific model. While the price factor and brand reputation are noteworthy, technical characteristics play a more critical role. Although reputable brands generally offer high-quality specifications, it's essential to focus on specific characteristics. Below, we outline key features and the optimal ranges for a good DAC.

Bit Depth

Bit depth refers to the number of bits of information recorded for each digital audio sample. The higher it is, the less noise and distortion there will be in the processed file. Typically, DACs support bit resolutions from 16 to 32 bits. For Hi-Res audio, it is recommended to use a DAC with a bit depth of at least 24 bits.

Sampling Rate

Determines the number of samples collected per second when converting a signal. The higher this setting, the more detail and frequency can be recorded and played back, and the closer the digital audio is to analog. DACs typically support sampling rates from 44.1 to 384 kHz. For high-resolution audio, it is recommended to use a DAC with a sampling rate of at least 96 kHz.

Signal to Noise Ratio (SNR)

This parameter shows how much the audio signal exceeds the noise level. The higher it is, the cleaner and clearer the audio, and the less interference and background noise there is. For high-quality audio, it is recommended to use a DAC with an SNR of at least 100 dB.

Total Harmonic Distortion + Noise

A lower Total Harmonic Distortion plus Noise (THD+N) value signifies more accurate and authentic sound with reduced harmonics and noise. This parameter is usually measured in percentage (%) or decibels (dB). For superior audio quality, it's advisable to use a DAC with a THD+N below 0.01% or -80 dB.

What DAC do you need?

Now, when you know the ins and outs of digital-to-analog converters, the task of choosing the right model shouldn't be difficult. But we'll make it even easier for you by narrowing it down to the three most common scenarios.

Computer — speakers, headphones

If you want to connect a DAC to a computer or laptop and use it with speakers and headphones, you need a desktop DAC that has a USB input, an RCA output, and a headphone output. You also need to consider the consistency of the DAC with the operating system and your speakers and headphones. For example, if you want to drive high impedance headphones, you need an amplifier that has a lower output impedance. The speaker system must be powerful and accurate enough for you to feel the difference with and without a DAC. It doesn't matter how well a DAC converts digital code if the resulting signal is degraded on the speakers.

Recommended desktop DACs for PC:

Smartphone, MP3 player — headphones

To improve the sound in headphones from your smartphone or player, all you need is a compact, portable DAC that runs on battery or audio source, has a digital input compatible with your device, a corresponding headphone output, and is matched to the headphones in impedance and sensitivity. The compatibility of the reproduced formats should also be taken into account. For example, if you want to listen to music in DSD format, you need a DAC that supports this format.

Recommended portable headphone DACs:

Guitar, keyboards, microphone — headphones, audio system

For this purpose, you'll require an audio interface equipped with instrument and microphone inputs, phantom power for electret microphones, and suitable outputs like USB, AUX, RCA, etc., for connecting to a computer, speakers, or headphones during recording and sound processing. Additionally, consider the desired DAC resolution and sound quality, along with the availability of effects and operating modes for enhancing or altering instrument sounds. For example, if recording a guitar in PCM format, ensure the DAC supports this format. If you wish to incorporate effects like reverb, distortion, chorus, etc., the DAC should have built-in or plug-in effects processors. Crucially, prioritize minimal audio latency for a comfortable real-time playing experience. Recommended audio interfaces for musicians:

Summary

So, now you know how important a digital-to-analog converter is for lovers of high-quality audio. If you want to get real Hi-Fi, before buying a DAC, listen to each device if possible and choose the one that is most pleasant to the ear. If this is not possible, use our guide. We hope it helps you. Have a good audio and happy shopping with E-catalog!