You might not even think about it, but most of us use at least one digital-to-analog converter (more commonly known as a DAC) every day.
Integrated into computers, tablets and smartphones, the DAC is the fundamental key to unlocking the convenience of digital music. It converts the countless reams of digital information into an analog signal intelligible to speakers and headphones, as well as to the human ear.
Any device that acts as a source of digital sound – whether it’s a CD or Blu-ray player, digital TV box, game console, or portable music player – will need a DAC to convert its audio to an analog signal before it is output.
Traditional amplifiers don’t handle digital information, speakers certainly can’t read digital information, and our ears can’t interpret digital information – they all need an analog waveform. Without DACs, your digital music collection is nothing more than a large collection of “0’s and 1’s” (more on this shortly) that only make sense in the digital realm. In short, DACs play a big role in the promotion of digital music.
The biggest problem is that the DAC circuits used in many devices just aren’t efficient enough to do the original recording justice, so a DAC upgrade may be the easiest way to improve your music. digital and get the most out of your system. Whatever your configuration.
What is a DAC? What does it do?
The sounds we hear every day – traffic, instruments, that crying baby on your otherwise peaceful journey – are transmitted as sound waves, which travel through the air to our ears in a varying analog signal. permanently.
Analog recordings were stored on records like shellac (and later vinyl), and later still on magnetic cassettes – but the fragility and unwanted noise of these formats gave way to something new. The CD was born, kicking off the digital audio revolution in the process.
Digital audio takes a very different approach than analog. Digital music files typically come in the form of pulse code modulation (PCM) and are created by measuring the amplitude of the analog music signal at regular intervals.
The magnitude value is represented as a binary number (composed of 1s and 0s) and the length of this number is often referred to as the bit depth. The synchronization of the measurement intervals is called the sample rate.
When recording a standard CD, say, a sample is taken 44,100 times per second. Each of these samples is measured with 16-bit precision, storing the results in a 16-digit binary format.
Record a high-resolution track, on the other hand, and you’ll step forward up to 24-bit, with a sample taken as often as 192,000 times per second.
Digital audio data can be stored in a variety of sample rates, bit depths, encoding and compression formats – but no matter how it’s done, it’s the job of the DAC to give make sense to it all, translating it as accurately as possible from its binary format to make it as close as possible to the original analog recording.
Why do i need a separate DAC?
While it is true that almost all digital kits feature a DAC, it is equally true that not all DACs are created equal. For starters, they may not support all file data rates.
Bad converters can introduce unwanted noise during playback due to poorly designed circuitry, not to mention adding additional distortion due to jitter. (Jitter is best defined as digital timing errors. Accurate timing of a digital music stream is vital for high performance, and if not done correctly – usually because of a clock circuit. poorly designed digital – performance suffers.)
Jitter issues can arise any time a digital signal has to travel through a printed circuit board – and this is especially troublesome when the signal is transferred between devices. In recent years, we have seen the rise of the asynchronous DAC, which takes over the synchronization tasks of any computer it can be connected to for that reason alone.
Digital clocks found in dedicated hi-fi DACs tend to be more accurate than those used in the average PC, so generally the conversion process will be done more faithfully.
Source material is everything
Of course, to get the most out of a DAC you have to start with good source material – don’t expect miracles if all you throw in a converter are 128 kbps MP3s. In fact, better decoding of such a compressed signal can make the sound defects more evident.
You’ll hear optimal results with CD quality and higher content, which is best stored in lossless PCM formats FLAC, WAV, or ALAC (Mac), or alternatively DSD if you prefer.
What are DSD and PCM?
DSD, or Direct Stream Digital, is an alternative to PCM and was originally designed for Super Audio CDs (SACDs) – a format championed by Sony and Philips in the late 1990s and into the 2000s.
It’s a much more specialized format, different from PCM by offering a bit depth of just one, but much higher sample rates – typically DSD64 at 2.8 MHz and DSD128 at 5.6 MHz.
Arguments as to which encoding system is the best continue to rumble. Suffice to say, if you’re someone solidly seated in the DSD camp, it’s worth checking that the DAC you’re considering supports it – most, but not all, do.
What type of DAC is right for you?
DACs come in all shapes and sizes and offer varying levels of input options and features, so you’ll have to think about how you want to use it, not to mention the budget you’ve budgeted for.
Compact USB DACs offer portability and convenience at a reasonable price. They vary from USB sticks (such as the Audioquest DragonFly Red) which connect to a laptop, to more modern USB-C cable DACs (like the Astell & Kern AK USB-C Dual DAC cable above) which connect to connect to a phone with this connection. .
Most often, they use power from your computer or phone, so you don’t need an additional power source. They keep largely simple connections, with just a headphone jack and possibly a line-level output for connection to powered speakers or a hi-fi system.
If you need more connectivity and don’t want to take your DAC with you, a desktop USB drive may be more suitable. These are usually larger and require their own power source, but often offer several additional digital or analog audio inputs as well as a USB input for connection to your computer. Some, like the iFi Zen DAC V2, can be either USB Where mains powered.
Keep an eye out for a DAC with a headphone amp if you want to use headphones, because no all DACs offer this as an option – the award-winning Chord Qutest, for example, is a stand-alone DAC without any headphone functions, designed to slip into a system between a digital source and an amplifier.
Finally, there are the DACs which were born to function as part of a larger home audio system. These will usually have even more inputs – especially more niche sockets such as AES / EBU – and potentially more functionality as well. They’ll support the full range of hi-res music formats, for example, or offer Bluetooth connectivity for wireless streaming from your smartphone or tablet (which portable and desktop units also tend to offer these days). .
Some will even come with a volume control, so they can also be used as a preamp.
These can range from the sensible (the Audiolab M-DAC +, say) to the extravagant (the Chord DAVE) or, if money really isn’t an issue, the Nagra HD DAC / MPS.
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