Audiophile Series: E2 - DAC

DCS Bartok ($15000)

To understand what a DAC (digital-to-analog converter) does, you must know that all the music you listen today is digital. It is stored in computers and the internet not as analog wave files (not to be confused with the .wav file extension), but as a digital file.And as you know, a digital file is nothing but a series of 1s and 0s, i.e. binary code. Your brain can’t hear binary code. So before you can hear a digital file, you need to convert the series of 1s and 0s into something that can be heard by human ears, i.e. an analog file. And how do you do this? Yeah, you need a so called “DAC”

Hold on… you have internal DAC

Yup, that’s right. Every computing device capable of playing audio already has a DAC built into it. Even a $5 chipset has an DAC. Otherwise you wouldn’t be able to play any audio at all.

So Why Do I Need an External DAC?

In short, just because the internal DACs of our smartphones and laptops are just ok for regular consumers, but not good enough for audiophiles. So, there are people who spend from $50 to $10000 just for DAC.

Digital music files are usually in the form of a “Pulse Code Modulation” (PCM). PCM is a method to digitally represent analog signals. This is done by tracing an analog signal and dividing it into small sections, like this:

For normal CD-quality audio (16 bit 44.1 kHz) this is a tremendous amount of computation – 44,100 measurements each second, 16-digits for each measurement (which equals 16 x 441000 = 705,600 digits per second). And that’s just for CD-quality audio. Even better audio files like 24 bit 192 kHz it means 4,608,000 calculations per second. As you can imagine, all these calculations aren’t easy. The DAC has to accurately estimate the amplitude of each wave and translate it into a binary code (and vice-versa). And it has to do it hundreds of thousands of times each second. If there are any errors in the estimation or calculation, the resulting sound will not be as accurate as the original analog signal.

You may see a digital timing error in the whole process. To accurately capture an analog signal, the DAC has to estimate the amplitude, play/store it, estimate again, and so on. If the digital circuitry is poorly designed, there can be minute lapses in this estimate-play process. This is called jitter, which can add extra distortion to a audio signal.

An external, standalone DAC will vastly improve the accuracy and “cleanliness” of the sound. Since there is less jitter, you won’t hear as much harmonic distortion. The difference between your computer’s DAC and an external DAC in terms of clarity is mind-blowing the first time you hear it.

DAC Classifications

For most users DACs can be classified into the following categories:

Desktop DACs

These DACs are typically small enough to fit on a desk, but not so tiny that you can carry them around in your pocket. Desktop DACs typically have a built-in amplifier and a headphone jack, powered by USB usually.

Portable DACs

These DACs are slightly bigger than a pendrive in size. Most portable DACs have built-in amps and headphone out (mostly 3.5mm minijacks) Portable DACs almost always run on USB power.

Component DACs

If you own a full-fledged home audio system and need a DAC that can give you enough juice to power it up, then you need a component DAC. These are large, expensive and complex devices with high-end circuitry designed to extract the best possible audio quality.

DCS Vivaldi ($110,000)

 Most component DACs have a number of ports, including RCA, XLR, etc. Component DACs typically use AC power though a few also take in USB. Component DACs tend to be expensive; expect to pay upwards of $500 for a competent one. While most of these DACs have built-in amps, a few very high-end models focus entirely on the audio processing and need external amps.

Hacks

 1. If you don’t have access to high-quality audio files (DSD, WAV, FLAC), don’t spend too much on a DAC. A $5,000 Benchmark DAC will fall flat if you feed it a highly compressed MP3 file.

2. Buy DAC according to the system you need to feed. A component DAC with four digit price tag is no good if you only have an entry level headphone.

3. At the very minimum, you should have an entry level, audiophile grade headphones/speakers before you buy a DAC. At least a set of Audio Technica M50x or beyerdynamic DT990PRO should be your baseline (~$150). Otherwise you’re going to have a stellar audio signal, but no way to actually hear it in all its glory.

4. In conventional standalone DACs, the signal output from the DAC is not strong enough to be heard over headphones/speakers. In such cases, you would need to add an amplifier to your mix. Of course, that’s only for high-end standalone DACs. Most of the best budget DACs often come with a built-in amplifier that can boost signals enough for headphones/speakers.

5. If you use a wireless headphone, you won't need a DAC, they have built in DAC inside headphone and you can't replace them.

Reference:
https://midination.com/
https://www.youtube.com/channel/UCQIcXQ2n0sa-7CD0NtqnrrA