A DAC, or digital-to-analog converter, converts digital signals into analog signals. DACs are built into a variety of audio devices, including CD and DVD players. The DAC has one of the most important jobs for sound quality: it creates an analog signal from the digital pulses stored on the disc, the precision of which determines the sound quality of the music we hear.
An external DAC is a separate component that is not built into the player, and it has many popular uses among audiophiles, gamers, and computer users. The most common use of external DACs is to upgrade the DAC in an existing CD or DVD player. Digital technology is constantly changing, and even a five-year-old CD or DVD player's DAC may have improved since then.
Adding an external DAC allows you to upgrade your player without replacing it, extending its lifespan. Other uses for external DACs include upgrading the sound of music stored on a PC or Mac computer or enhancing the sound quality of video games. In short, it's an effective way to improve your sound quality without changing your audio source.
The main benefit of a good external DAC is sound quality. The audio quality of digital-to-analog conversion is highly dependent on bit rate, sampling frequency, digital filters, and other electronic processes. Specialized DAC designed for optimal audio performance. DACs are also improving every year, and older DACs (such as those in older CD and DVD players) don't perform as well as newer models. Computer audio also benefits from an external DAC, since the DACs built into computers are often not the best quality.
- Upsampling : A typical CD contains digital music stored at 16-bit resolution and sampled at 44.1 kHz. 16-bit/44.1 kHz is known as Red Book CD and is an industry standard. Many external DACs have an upsampling feature that can improve audio quality. For example, the resolution is 24 bits and the sampling frequency is 192kHz. Sound quality differences include a wider frequency response and higher dynamic range.
- Jitter reduction : Jitter is a digital event that affects the timing of digital pulses. It is sometimes described as an "erratic pulse" and if controlled or eliminated, sound quality can be improved. Most DACs employ some form of jitter reduction technology.
- Multiple inputs : Some external DACs have a single digital input, while others have dual inputs for multiple components. The advantage of dual inputs is that they allow you to connect two sources at the same time, such as a CD player and a PC.
- USB input : Many external DACs include a USB input to allow the computer's audio output to be connected to the DAC. An external DAC can enhance the sound quality of computer audio sources.
