Buyer's Guide: Audio Converters

A quality audio converter is one of the most crucial components in any modern studio. A cheap audio converter can make a million-dollar vocal chain sound like it was recorded through a dial-up modem. But a high-quality audio converter will add depth and detail to your recordings.

In this Buyer's Guide, we’ll break down everything you need to know about audio converters to help you find the perfect solution for your studio, including sample rates, bit depth, and advanced connectivity options. But before we get started, let’s talk about the history of audio converters.

History of Audio Converters

The world’s first digital recording was captured and released in 1971 using an experimental PCM recording system from the Japanese broadcasting company NHK.

Although commercial digital recordings were possible as early as the 70s, it wasn’t until Sony released the PCM-501ES digital audio processor in 1984 that CD-quality digital recording technology would become widely available.

Studios quickly realized the benefits of working in the digital domain, but they weren’t without their limits. In its infancy, digital recording devices were extremely expensive, and those that weren’t tended to sound harsh and shrill.

As technology continued to advance, the sound quality improved, and digital audio interfaces became commonplace in professional recording studios. In 1999, Ricky Martin’s "Livin’ la Vida Loca" was the first song recorded, edited, and mixed entirely in the box. Today, most professional studios rely entirely on digital audio systems, with much of the workload being carried by digital audio converters.

Differences Between Analog and Digital Audio

While digital audio converters have become the norm in modern recording studios, it's essential to understand the differences between analog and digital audio before making a decision.

Analog audio is a continuous electrical signal that corresponds directly to the sound wave being recorded. The quality of an analog signal is determined by the resolution of the signal chain and the quality of the equipment used. The downside of analog audio is that it can be easily degraded by noise or interference, and it's difficult to manipulate or edit once recorded.

Digital audio, on the other hand, converts the continuous analog signal into binary code. This conversion allows for editing and manipulation of the audio, as well as the ability to store and transfer it easily. Digital audio also has the advantage of being able to be copied and reproduced with no loss in quality.

However, converting the analog signal into a digital format can introduce distortion, which is why high-quality analog-to-digital converters are essential for achieving optimal sound quality. Additionally, the process of converting digital audio back into analog format can also introduce noise and distortion, which is why high-quality digital-to-analog converters are necessary.

What Is a Digital Audio Converter?

On a basic level, digital audio converters (DACs) convert audio signals from one type of signal to another.

What is an Analog To Digital Audio Converter?

Analog-to-digital (AD) converters transform analog audio signals, such as the output of a preamp or other piece of outboard gear, into digital audio signals that can be processed by your computer.

What is a Digital To Analog Audio Converter?

Digital to analog (DA) converters work in reverse, converting digital audio signals, such as those played by your DAW or web browser, into analog audio signals that can be recreated by your studio monitors or headphones.

Most modern audio interfaces include limited DACs to enable simple digital recording, but for high-quality recording or particularly large sessions, you’ll need a standalone DAC. Most DACs include both AD and DA converters in the same unit, as well as a few other pieces of technology.

What Does a DAC Do?

DACs are responsible for three main tasks in the conversion process. First, they sample the analog audio signal. No, not like sampling a song in hip hop, it’s more like taking a burst photo on your smartphone.

DACs take tens of thousands of ‘digital snapshots’ each second when sampling an analog audio signal. The more samples the DAC is able to capture, the more accurately it can recreate the audio signal in the digital domain. More on that later...

Once the analog audio has been sampled, the DAC assigns each sample to a different timestamp within the waveform through quantization—similar to lining up transients to the grid in your DAW.

Once the quantization occurs, the signal is converted into a binary code that your computer can process. This code represents the exact voltages of the waveform at any given time. By ‘connecting the dots’ of each sample, your speakers are able to accurately recreate the sound being played back from your DAW.

By adjusting the sample rate and bit depth of your DAC, you can control the quality of your digital audio recordings.

What Is Sample Rate?

Sample rate is a measurement of how many samples your DAC takes per second when sampling audio. Most professional DACs offer the following sample rates:

44.1 kHz / sec
48 kHz / sec
88.2 kHz / sec
96 kHz / sec
192 kHz / sec

The minimum sample rate for CD-quality audio is 44,100 samples per second. It may seem like an odd number to use, but it wasn’t selected randomly.

According to the Nyquist–Shannon sampling theorem: “the sampling frequency must be greater than twice the maximum frequency one wishes to reproduce.” Since the human hearing range maxes out at roughly 20 kHz, the sampling rate had to be greater than 40 kHz.

Digital audio was developed alongside digital video, and 44.1 kHz was deemed the highest usable rate compatible with both PAL and NTSC video. To this day 44.1 kHz remains the minimum standard resolution for digital audio.

However, by using a higher sample rate, your DAC is able to capture more information and more accurately recreate the audio signal. Using high sample rates comes at a cost. It also creates more stress on your processor, restricts the number of channels you can work with, and creates significantly larger audio files.

What Is Bit Depth?

Bit depth controls the amount of dynamic range in a digital audio recording or the amount of space between the loudest and quietest sounds. Most professional DACs operate at the following bit depths:

16-bit
24-bit
32-bit float

A bit is a binary digit or a single unit of code. A bit only has two values: 1, or 0. On, or off. Max volume, or mute. But with multiple bits, you can create more combinations, resulting in more values. For instance, with two bits you can create four combinations: 00, 01, 10, and 11. And each of those values can be assigned a different meaning.

In a digital audio system, each value is assigned a specific amplitude of the audio waveform. With a high resolution, you can accurately map the exact amplitude of each peak on a waveform. But with a low resolution, you’re not able to be as accurate, and the quality begins to suffer. For instance, in a 24-bit system, you have more than 16 million possible values to choose from, while in a 16-bit system, you have just over 65,000.

The minimum standard bit depth for CD-quality digital audio is 16 bits, but using a higher bit depth offers greater dynamic range, improved signal-to-noise ratio, and more headroom. Higher bit depths allow you to make the loud moments louder and quiet moments quieter without introducing additional noise.

What Is A Word Clock?

Antelope Audio Isochrone OCX HD Master Clock

A word clock, sample clock, or master clock is a precise oscillator used to synchronize multiple digital audio devices. Most DACs include built-in word clocks, although they are also available as standalone devices.

When working with multiple digital audio devices, you need to sync their internal clocks to ensure they record everything perfectly in time—down to the last sample. Otherwise, you run the risk of creating digital artifacts in the form of nasty clicks and pops.

In most home studio settings, the audio interface clock operates as the master clock for any additional devices. But in pro studios, which often require more complex signal routing, many engineers choose to use a stand-alone device.

Similar to upgrading from an all-in-one recording interface to standalone preamps and DACs, a dedicated word clock can offer a significant improvement over your sound.

How To Choose A DAC

ANTELOPE AUDIO PURE2 - 2-CHANNEL MASTERING CONVERTER

When it comes to choosing a DAC, it really comes down to three things: budget, sound quality, and connectivity.

Budget

There is a wide range of options in the world of DACs and finding something that works within your budget is incredibly easy. From audio interfaces that feature on-board AD/DA converters to modular systems like the Burl Audio B80 Mothership that offer scalability, you'll be able to select the right option for your price.

Sound Quality

As for sound quality, professional DACs typically strive for a neutral, transparent sound. However, some converters are known for adding a certain sonic signature. Some models deliver crystal-clear highs, while others offer deep lows. And then there’s the Burl B80 Mothership, which is loaded with transformers to add color, vibe, and soul to your tracks.

Connectivity

When it comes to connectivity, the first thing to consider is channel count. Mastering converters like the Antelope Audio Pure2 offer two channels of high-resolution AD/DA conversion. However, for most recording and mixing projects, you’ll need at least eight dedicated inputs and outputs.

Most DACs include both AD and DA converters in a single unit, and can seamlessly stream anywhere from 8 to 64 channels at a time, depending on the resolution. For large productions in need of more than 64 channels, you can chain multiple DACs together.

Some manufacturers create separate units for AD and DA Conversion. Typically, AD converters are optimized for recording, like the Grace Design m108 and Dangerous Music Convert-AD+, both of which feature built-in preamps.

DA converters, on the other hand, are optimized for mixing with ample outputs for interfacing with outboard gear, as well as surround sound support or even a built-in summing mixer like the Crane Song Egret.

DACs typically offer several options for interfacing with your computer. If you’re looking for a quick and easy way to connect with professional Pro Tools rigs, try a DAC with a Digilink or Digilink Mini output.

For those who need more flexibility for interfacing with multiple devices or rooms, many DACs offer Ethernet and AES outputs for advanced networking capabilities. And finally, if you’re just looking for a high-quality DAC to use with your laptop or desktop computer, most models come with USB, Thunderbolt, or FireWire connections.

Next, we'll further breakdown some of the preeminent converters available to help take your studio to the next level.

Find The Best Analog to Digital Audio Converters For Your Studio

Most professional studios are very familiar with running an Avid workflow. Avid Digilink connectivity (via Avid HDX systems) is the most common approach as it allows for full use of HD-level software features within Pro Tools. For an Avid-based converter solution, the brand's MTRX series is always a fantastic option.

Just because you work with Pro Tools doesn't mean you're confined to Avid converters. Many third-party manufacturers make systems that will run perfectly within your workflow.

BURL B80 Mothership audio interface and converter.

Burl Audio has been a popular option for studios all over the world, as the B80 and B16 Mothership offer many different kinds of connectivity including DigiLink, MADI, Waves SoundGrid, and Dante. When you purchase a Mothership chassis, you're able to build your own rig with the brand's daughter card system and take full advantage of discrete Class-A analog electronics.

Focusrite RedNet A16R Dante audio converter

When it comes to Dante connectivity, Focusrite's series of RedNet converters have become a major player in many studios that run Audio Over IP. The RedNet series includes an incredible number of different interfaces that make compiling a versatile system of converters for your studio extremely easy.

Another brand that has become known as a studio standard is Lynx. The Lynx Aurora line of converters is a fantastic option for any facility, as these converters are beloved for their extremely transparent results.

Audio Interfaces With Built-In Converters

Two Universal Audio Apollo audio interfaces sitting on a guitar amp.

The easiest all-in-one solution for studios that are smaller in size is to take advantage of audio interfaces that feature built-in converters. Universal Audio, Antelope Audio, Apogee, Solid State Logic, and many more have brought world-class conversion down to 19-inch rackmount and desktop-size interfaces.

If you need help deciding which audio converter is right for your studio, please contact a Vintage King Audio Consultant via email or by phone at 866.644.0160.