We’ve been in the digital age for quite some time now. Television signals are received digitally and music is usually stored in digital form. While there is no reason to cling to old tecnologies when it comes to television, there are some who argue for the supremacy of analog for music playback. This is probably because no matter how music is stored, it must be played back – and heard – as an analog signal; that is, as sine waves with frequency and amplitude.
The analog signal can, therefore, be thought of as the “pure” audio signal. If the original recording is not stored on vinyl or some other analog sound storage medium, it will have to be converted into digital. Since CDs and all sorts of digital music formats like MP3s and FLAC are by far the most popular way to store and transmit music these days, the vast majority of analog signals are converted into digital using pulse code modulation, or PCM for short. This breaks down the sound waves into discreet digital bits for storage.
In order for a digital signal to be played back, it will need to be converted back to analog. The devices that perform this task are known as digital to analog converters, or, more commonly, DACs.
You may never think about them, but DACs are everywhere
Digital to analog converters process digital signals so that they can be used by analog systems. MP3 and CD players, iPods, smartphones, PCs, laptops, most televisions and streaming speakers all include integrated digital to analog converters. If your smartphone didn’t contain a DAC, it would not be able to send the audio signal to your headphones via a 3.5 mm headphone connection.
Many amplifiers and A/V receivers on the market today include integrated DACs. For a really good sound, however, it’s not recommended to connect your playback device to your receiver or amplifier’s headphone output as the integrated audio converters don’t generate a good result, especially when compared to the digital connections such as the standard TOSLINK. These generally get the most out of digital devices.
Plug-&-play: Every day uses for DACs
There are many products that fulfill the same basic digital to analog conversion function with prices ranging from 20 to 2,000 euros or more. In the lower end of this spectrum are small DACs that look like little plastic boxes. On the front and back sides are the required audio connections. Some models even offer USB ports so that they can also be connected to a PC and used as an external sound card.
A volume regulator is advantageous, but does not come standard issue with all introductory model DACs. Most devices are limited to a DAC’s most basic function: Converting digital signals into analog signals. This makes them perfect intermediaries between televisions and music systems. Naturally, MP3 and Blu-ray players can also be attached, but truly hi-fi sound quality cannot be expected in the lower price segment. A lower-priced external DAC, however, can still do wonders for the sound produced by your PC as the sound cards that come with PCs are often compromised by noise generated by other components in the system.
Premium DACs prove that digital can be hi-fi
For those who want to convert digital signals into the highest quality analog signals won’t get very far with entry model DACs. As with the DACs built into many MP3 and CD players and even amplifiers, the technology used is not of the highest caliber. A truly high-end DAC, however, can be a true asset for your hi-fi system. Premium DACs will naturally cost more, but the investment can give a traditional hi-fi system a new lease on life. A high-performance DAC can make an audiophile’s transition from records to digital media, or from CDs to hi-res audio files completely painless. In the highest price segment are DACs such as the Audio Research Reference DAC. The device admittedly costs as much as a small car but completely lives up to its name as the reference in this area.
High-end DACs are much more than just digital to analog converters. Many are also amplifiers that include all possible connections for digital music listening. Many premium DACs can wirelessly connect to the internet, receive internet radio stations and offer an optical as well as a coaxial S/PDIF input as well as up to three USB connections – one for the computer and a special connection for iPod, iPhone and iPad as well as an input in the front for USB pen drives.
Coda: DACs let loudspeakers play back digital music
Any time a digital signal is played back on loudspeakers, a digital to analog converter is required. Most digital music players from MP3 players, smartphones, PCs, amplifiers and A/V receivers have integrated DACs. Since music streaming uses digital files, the speakers that receive and play back these signals will also have to have their own integrated DACs. Likewise, Bluetooth headphones that receive a digital signal wirelessly will need integrated digital to analog converters. The better the streaming speaker or headphone, the better the DAC, such as the hi-res DAC from Cirrus Logic built into the Raumfeld Stereo L.
Most integrated DACs, however, are serviceable at best and won’t support hi-res audio files. Using a semi-professional external DAC such as the Reference DAC from Audio Research will not only deliver the best sound quality, but also support the widest range of files. For audiophiles with serious digital music collections, this might be an attractive option, but – like all higher end audio gear – it’s going to cost you.
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