What is DAC, and Do You Need One?

A DAC, or digital-to-analog converter, converts digital signals into analog signals. DACs are built into various 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 a disc, and its accuracy determines the sound quality of the music we hear.

What Does an External DAC Do?

An external DAC is a separate component not built into a player, and it has many popular uses for audiophiles, gamers, and computer users. The most common use of an external DAC is to upgrade the DACs in an existing CD or DVD player. Digital technology is constantly changing, and even a five-year-old CD or DVD player has DACs that have probably seen improvements since then.

Adding an external DAC upgrades the player without replacing it, extending its useful life. Other uses for an external DAC include upgrading the sound of the music stored on a PC or Mac computer or enhancing the sound quality of video games. In short, it's an effective way to upgrade the sound quality of many audio sources without replacing them.

What Are the Benefits of an External DAC?

The main benefit of a good external DAC is sound quality. The audio quality of a digital-to-analog conversion is highly dependent upon bit rate, sampling frequency, digital filters, and other electronic processes. A specialized DAC is designed for the best audio performance. DACs are also improved year over year, and older DACs, such as those found in older CD and DVD players, do not perform as well as newer models. Computer audio also benefits from an external DAC because the DACs built into computers are generally not the best quality.

Features to Look for on External DACs

• Upsampling: A typical CD contains digital music stored at 16 bits of resolution and sampled at 44.1 kHz. 16-bit/44.1 kHz is known as Redbook CD, an industry standard. Many external DACs have upsampling, a feature that improves audio quality. For example, the resolution is 24-bit, and sampling is performed at 192 kHz. The sound quality differences include wider frequency response and higher dynamic range.
• Jitter Reduction: Jitter is a digital event that affects the timing of the digital pulses. It is sometimes described as 'shaky pulses' and can improve sound quality if controlled or eliminated. Most DACs employ some form of jitter reduction.
• Multiple Inputs: Some external DACs have a single digital input, and others have dual inputs for more than one component. The advantage of dual inputs is that they allow you to connect two sources, such as a CD player and PC, at the same time.
• USB Inputs: Many external DACs include a USB input to allow the audio output of a computer to connect to a DAC. An external DAC enhances the sound quality of computer audio sources.