October 18, 2012
| by EH Staff
Over the past few years digital music has become the darling of the audio world. People like it because they are able to access and store large libraries of music on their mobile device, their A/V receiver or some other product. In order to hear digital music, though, it must be converted to an analog signal that your speakers can reproduce. This is the job of a digital-to-analog converter, or DAC for short.
Digital-to-analog converters have been around for decades. They are used in cellphones, tablets, iPods, flatpanel televisions, iPod docks -even your children’s toys have them. All of these devices employ a DAC of some sort to convert digital signals so that you can hear them. The big news today is the USB DAC- the kind that plugs into your audio system or computer. When you add one of these standalone devices to your setup, that digital music will sound purer, clearer and closer to the actual recording. Not all DACs are created equal. The majority of ones we use every day are made to be affordable. Think of the average iPod dock you can get at your local pharmacy for $24.99. Odds are its internal DACs were designed for cost efficiency instead of sound quality. This isn’t to say you can’t enjoy the music it plays, but you’d probably prefer how the music sounds when played through an iPod dock that uses higher-quality DACs. Just think back to when you traded up from a standard-definition to a high-definition TV; the same experience is possible for your ear by investing in a quality DAC.
What Do DACs Do?
DACs have a very tough job. They are bombarded with a huge amount of data that takes the form of thousands of ones and zeroes in the digital signal. A standard CD has 16-bit resolution at 44.1 kHz (44,100 samples per second). This is a lot of information for a DAC to handle. If a DAC is implemented poorly, it can impact the complex transfer of data, creating timing errors that result in jitter. Digital jitter creates distortion and can negatively impact sound quality. With a high-quality DAC, it is possible to hear a natural and crystal-clear reproduction from a digital signal. With a budget DAC, you will most likely not be able to hear as deeply into the music.
There is a large variety of DAC manufacturers; some of the key ones are Texas Instruments, Analog Devices, Wolfson, ESS Technology and Cirrus Logic. These five companies make some of the most advanced and trusted DACs available. Some of these manufacturers have even ventured into upsampling—a process by which the sample rate of a signal is increased to help lower distortion and improve sound quality. The benefit of upsampling is a highly debated topic, but various companies have implemented it successfully.
Over the past 10 years the use of DACs has changed significantly. Homeowners are doing away with CD players and replacing them with standalone DACs that can stream music directly from your home network. IPod docks have evolved to where they can pull the data directly to the DAC built into the dock. This has allowed manufacturers to put their own design spin on how they believe a DAC should be implemented, and they no longer have to rely on the quality of the iPod/iPhone’s internal DAC to produce a quality sound.
DACs play a vital role in home cinema, as well. Bluray discs have brought lossless audio into the home, so consumers can hear copies that are identical to the original studio masters. Consequently, using a receiver with a high-quality DAC is crucial, because it will ensure that these digital signals are converted properly so you get the best sound quality possible when you’re watching a movie. DACs that are more accurate allow you to hear more deeply into a movie’s studio mix and notice subtle nuances that add to the realism of the film. The hottest type of DAC currently is a USB DAC.
This type of DAC is ideal if you want to turn your computer into a high-quality audio source. In their infancy, USB DACs were forced to adapt to the rate at which the computer sent data packets, and they had to adjust their master clock every millisecond to keep the audio data flowing without any dropouts.
Computer-based audio took a leap forward, however, when “asynchronous” designs hit the market. Asynchronous USB DACs take complete control of the data flow and allow for the data packets to be sent at a fixed rate dictated by the USB DAC’s own master clock. It is widely regarded that asynchronous USB DACs are the best sounding, and the majority of top-rated USB DACs have adopted this design.
If you have been sitting on the sidelines wondering if you should get into digital audio, now is the time to do it. Never before has it been so easy to improve the sound quality of your system. Whether you have a television, DVR, Blu-ray player, gaming system, an old CD player or one of each, they will all benefit from a high-quality DAC.
By running the digital audio through a quality DAC, you’ll be able to enhance the sound quality of your digital music and your listening pleasure.