What is a DAC?
A DAC, or digital-to-analogue converter, is an electronic device that converts digital audio signals into analogue audio signals. Most audio files, such as those found on CDs, MP3s, or streaming services, are stored in digital format, which means they need to be converted into an analogue signal before they can be played through speakers or headphones. This is where a DAC comes in.
A DAC takes the digital audio signal and converts it into an analogue signal that can be sent to an amplifier or directly to speakers or headphones. The quality of the DAC can have a significant impact on the overall sound quality, as a high-quality DAC can result in a more accurate and detailed audio signal. DACs can be found in various audio devices, including smartphones, computers, CD players, and dedicated DAC units. Some audio enthusiasts may choose to invest in a high-end DAC unit to enhance the audio quality of their music playback system.
How sound is generated and processed
Air pressure changes cause sound, which our ears translate into an electrical impulse that can be processed by the brain. Sound is an electrical signal, which behaves like a waveform with positive and negative values. The frequency, or number of cycles a wave completes each second, directly affects the pitch of a sound (higher frequencies result in higher notes). We can hear frequencies between about 20Hz and 20kHz (for more information on this subject, see our article on frequency response). Frequencies are measured in Hertz (Hz).
When a sound is recorded, it goes through the Analog to Digital Conversion process, in which waveforms are transformed into binary code so that technology can understand them. Fundamental knowledge of the reverse process, which goes as follows, is required to comprehend DACs.
An audio interface/soundcard’s ADC (Analog to Digital Converter) processes the audio waveform before sending it to the computer’s recording software. Binary code is used to record and encode the characteristics of this waveform so that they can be saved as data on a computer. Sample Rate, Bit Rate, and Bit Depth are the specifications typically relevant in this context.
The number of samples of the waveform that are taken each second is referred to as the sample rate. Film audio is typically set at 48kHz for better definition while CD-quality audio is typically sampled at 44,100 times per second (44.1kHz). Although there are other sample rates available, these are the most popular. Greater frequency definition and ultimately less noise in the recording correlate with a higher sample rate.
The converter’s ability to handle dynamic sounds depends on the bit depth.
Any volume above this threshold will result in unwanted noises (often clipping, an audio phenomenon where pops and scratches appear in the recording, similar to when you push the volume limit of a tiny Bluetooth speaker a little too hard). Low bit depth operates in a small volume range. Typically, a 16 or 24-bit setting is used for musical applications. Although Bit Rates aren’t really relevant to this discussion, it’s important to understand that they affect the overall definition and size of an audio file. A higher bit rate enables more samples to be recorded and stored, which leads to a more accurate recording.
A DAC converts binary information into an analogue signal.
Before worrying about DACs and where or how to use one in your system, it is important to make sure your digital music files are of high quality, as DACs will only amplify the sound of a track that is of low quality. Anything of CD quality or higher, preferably files in the.wav, FLAC, ALAC, or DSD formats, or at the very least, a high-quality mp3, are what I would advise.
If you’re serious about achieving superior sound quality, your listening medium is just as important as the source material in this case. If you don’t already have a good set of monitors or headphones, I’d suggest looking into some upgrades as well. Using stock mobile phone earphones or an entry-level Hi-Fi system will definitely hold you back. I’d suggest a set of flat-response reference monitors for the best audio quality or a set of open-back headphones that won’t significantly colour your source material and let the DAC do all of its magic.
Are DACs worth it?
DACs may be helpful, but are they priced fairly? It’s a difficult question to answer, and whoever you ask will determine the response you receive. It all comes down to what you hope to get from your audio experience, the sound equipment you already have, and your goals for the product.
In most cases, adding a DAC to your setup won’t produce the same experience as purchasing a new set of headphones, where the audio changes are frequently obvious. Instead, assuming you have the equipment that will be able to best utilize it, a DAC is able to add those few extra notches of quality for the critical listener.
It’s not uncommon to experience problems with the onboard DAC when using a computer, which can lead to static or other audio problems. These kinds of issues can sometimes be solved with the aid of an external DAC.
There is certainly something to be said for adding a DAC to one’s setup for audiophiles who pay close attention to each nuance, but casual music listeners are unlikely to ever truly benefit from having a DAC.
What kind of DAC do I need?
Your intended uses will have a significant impact on which type and model of DAC would be the most suitable for you. DACs come in a variety of form factors.
Units in the form and size of a USB stick for a laptop or PC or a small USB-C cable that can connect to your phone are available on the more portable side of the DAC market. These are helpful if you’re planning to use one to improve the audio capabilities of your phone or laptop, for example. These small units are typically powered by your device, negating the need for an external power source.
These are useful for carrying your DAC around, but they typically only provide USB and a 1/8-inch headphone jack for connectivity. The AudioQuest DragonFly is a great-sounding, compact DAC that can be used with a laptop or PC. It is only slightly bigger than a flash drive. It is USB-powered and has a supplied 1/8-inch minijack connection for connecting to headphones.
A desktop unit might be better for you if you want more connectivity but don’t intend to remove your DAC from its docking station. These can sit on your desk or TV unit and can provide highly versatile I/O like RCA, XLR, TS/TRS, or AES/EBU. These work best as part of your home theatre system or in studio and Hi-Fi applications. These DACs typically need their own power source, offer a variety of inputs and outputs, and these days, also support Bluetooth connectivity. Some desktop devices have their own volume controls as well, allowing you to use them as preamps if you so choose.
These kinds of DACs are widely used in the headphone audiophile communities in addition to studio applications. Purchasing a DAC almost becomes a necessity because getting the best sound quality is the name of the game for many audiophiles, especially if you’ve already made an investment in what is regarded as high-end speakers. The majority of headphone users continue to favour this style of desktop DAC.
I’d suggest something like the AudioEngine D1, which is reasonably portable but makes for a great permanent installation, for these applications. The D1 has its own output volume control, and because it is plug-and-play, you won’t need to reroute your computer’s sound every time you intend to use it.
Does a DAC need an amplifier?
Not always, unless you’re using a DAC for headphones. When using a DAC, you will require an amplifier to power your speakers if they are conventional passive speakers.
This is due to the fact that a DAC only functions as a signal converter; without an amplifier, it cannot provide enough power to your speakers. Users of headphones won’t typically need to use an additional amplifier because external DACs typically include a headphone amplifier. However, using a DAC with conventional speakers will require an additional amplifier in addition to the DAC.
All audiophiles can benefit from DACs, whether they want to maximize their speakers or headphones or improve the sound quality for gaming. DACs can be compared to a car’s spoiler in some ways. You can add a lot of spoilers to a Chevy Spark, but they won’t increase your speed. A DAC is probably not necessary and is unlikely to be beneficial for someone who doesn’t know the bitrate of their music files. Our recommendation would be to first concentrate on the speakers or headphones before picking up an external DAC if you feel that your built-in DAC is causing a bottleneck.