A DAC or Digital Analog Converter is a converter that transforms digital signals into analog signals so that you can listen to them through speakers or headphones. As you know, the music we listen to today usually comes in a digital format. The USB DAC is responsible for providing the necessary information to headphones or speakers transforming/encoding that same digital information from “ones” and “zeros” to waves.
We may not realize it, but most of us use some kind of digital-to-analog audio converter in our homes. They are integrated into computers, tablets, and smartphones. It is a fundamental piece for listening to digital music since it converts digital information into the analog signals necessary for the human ear to perceive them. Any device that acts as a source of digital sound, be it a CD or Bluray player, game consoles, or portable audio equipment, needs a DAC.
Traditional amplifiers do not amplify in digital, the speakers do not reproduce in digital and our ears do not hear in digital either: they need analog waves. Without a DAC, our music collection is nothing more than a collection of zeros and ones. The sounds that we hear in our day to day, such as traffic, people’s voices, etc, are transmitted in the form of sound waves, which travel through the air to our ears in an analog signal. Analog recordings were collected on vinyl records and cassettes, but unwanted noise and the fragility of the format gave way to the entry of CDs, which started the digital revolution at the end of the 20th century.
You should know that digital audio is very different from analog. Digital files are usually in the form of Pulse Code Modulation (PCM) and are created by measuring the amplitude of the analog music signal at regular intervals. The amplitude value is represented as binary numbers and the length of the numbers is commonly known as bit depth. The timing of the measurement intervals is known as the sampling rate. Digital audio information can be recorded at a variety of sample rates, bit depths, codes, and formats, but regardless of the differences, the work is done by means of a DAC, which translates the binary information as best it can to recover the original analog recording.
When is an external audio DAC necessary?
If every device that plays audio has an internal digital-to-analog audio converter, then why do I want an external one? What happens is that we are talking about sound quality, not whether it sounds or not. An external analog-digital converter can exponentially improve sound clarity.
Every laptop or desktop computer has a built-in DAC to reproduce the sound stored inside it digitally. The problem is that these parts are not of much interest to computer manufacturers, so they use cheap parts and end up being of dubious quality.
Generally, a more expensive DAC will have better audio quality. It generates less noise or distortion when compared to other lower quality. How good the sound gets is directly proportional to the money you invest, at least as far as DAC is concerned.
For example, a 280 dollar laptop produces an annoying noise when connecting headphones to the included port on the computer. It has enough volume to notice all the distortions thanks to the quality of the headphones. This is when we decided to purchase a DAC to improve the sound quality of what we hear.
How does a DAC work?
A DAC converts a finite abstract number (usually a fixed binary number) into a physical quantity (such as voltage). An ideal DAC converts the abstract numbers into a conceptual sequence of pulses that are then processed by a reconstruction filter, using some type of interpolation to fill in the information between the pulses. A DAC can reconstruct the original signal as long as it has the necessary bandwidth to perform the operation. On the other hand, a conventional practical DAC updates the analog voltage at regular sampling intervals, which are interpolated through the reconstruction filter.
How to use a DAC?
It is true that any digital audio equipment requires an analog-digital converter, not all are created with the same quality. For example, some may not support the information in certain audio files. Lower quality converters can introduce unwanted noise during playback, as well as some distortion and jitters. A jitter is something like a digital error with time or timing. The timing is vital for digital music. These problems, caused by poor DAC circuits, create the need for the use of external circuits to improve the sound when using computers or other digital devices.
Of course, to get the most out of a DAC we must use good audio formats. We cannot obtain miracles when we reproduce a highly compressed MP3, such as 128 Kbps. We perceive the best results when the DAC works with CD quality or higher, which is well compiled in formats such as FLAC, WAV, or ALAC (Mac), in addition to lossless PCM or DSD formats.
DAC for PC
Most of the analog-digital converters only need to be connected by means of a USB cable to one of the ports of our computer. Some DACs offer other connection options, such as FireWire, which handles audio input and output but does not provide power, unlike USB. There are also audio connection options through an XLR or RCA cable.
HIFI DAC for headphones and speakers.
Once we have connected a DAC to the PC, the next step is to synchronize the necessary equipment for the audio output. For music lovers, this may mean connecting the best speakers and headphones via a 3.5mm or RCA cable. This sends the output to an external amplifier to allow the listening experience. Some professional DACs offer us the option of XLR connections. Using a DAC can undoubtedly provide better sound quality, although this also depends on the other equipment we have. Using a good DAC may not cause differences in perception if we do not have good headphones.
DAC for laptop, iPhone, tablets and Android
As we have said, a DAC is used to convert digital information into analog sound signals. The audio DAC is low frequency and high resolution while a video DAC has a high frequency and low resolution. DACs have contributed a lot to the digital revolution. We can mention, for example, long-distance telephone calls. User voices are converted into electronic signals by a microphone, then the analog signal is converted back to digital by a DAC, which does the reverse of the DAC. The digital information is later divided into connectivity packages so that they can be received. The digital voice is then extracted and assembled,
What DAC to buy?
Analog-digital converters come in many shapes and sizes and offer different levels of options in terms of connectivity and functionality, so you have to think about what you need to use them for and your budget. Portable USB DACs offer portability and a reasonable price. They range from a size no larger than a USB stick, like the Audioquest DragonFly Black is not a too larger gadget for your home computer.
Most of the time they get energy from our computers or equipment, so there is no need for extra sources of energy. They have simple connections, headphone inputs, and some line output to synchronize it with sound systems. If you need more connectivity and are not worried about transporting the device, a larger desktop DAC may be a good option. These require their own power source but offer additional audio inputs. There are also devices designed to work as part of a large home audio system. These have more inputs, such as AES / EBU, and other additional features. They support the full range of hi-fi audio formats and can also offer Bluetooth connectivity for use with phones or tablets.
What is the best DAC on the market?
One of the most frequently asked questions is, in the case of needing an analog-digital converter, which one should we buy. We divide the DAC types into three, according to their quality and price: A, B, and C.
- A class A analog digital converter is for those users who really want the best sound quality no matter how much they have to invest. These are used by the most demanding audiophiles in order to seek the highest quality and fidelity.
- A class B converter is sufficient for most hobbyists. In general, a class B would be the best option in terms of quality / price. Its sound quality and price is inferior to class A DACs.
- Finally, class C devices are better suited to those users accustomed to the portable world or those looking for an easy way out of their connection problems. These DACs don’t have to sound bad, they’re just more versatile. These devices can perfectly replace a common sound card and are the best economic option.
We have written an additional article in which we take an in-depth look at several of the best DACs on the market across all three classes. You can check our Sound Culture page to find out about the technical specifications of these devices, turntables, and any music equipment. Meanwhile, we leave you with a video about the process of the DAC and ADC devices: