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If you use a digital file to store the audio signal, then it can be said that there is no music without a digital-to-analog converter. You may not notice, but most of us use digital-to-analog converters every day, often referred to as DACs.
Dac is the most convenient key to decoding digital music, it is built into computers, tablets and smartphones and other devices, can convert digital signals into analog signals, and through power amplification so that the human ear can hear. Any device that acts as a digital sound source — whether it's a CD or Blu-ray player, dab radio, set-top box, game console, or portable music player — requires a dac to convert its digital signal into an analog output.
Power amplifiers can't amplify digital signals, speakers can't be driven with digital signals, and our ears certainly can't understand digital signals, so we need analog signal waveforms. Without daCs, your digital music collection is just a collection of "0s and 1s". So the question is, how to upgrade your DAC, restore the original analog signal more accurately to improve the sound quality of the system? We'll teach you today.
What is DAC? What does it do?
The sounds we hear every day —traffic, instruments, the cries of babies—travel through the air to our ears in a continuously changing analog signal. Analog recordings are stored on vinyl records and cassette tapes, but the format itself is not easy to preserve and is prone to unnecessary noise. Later, people invented a new carrier, cd, and the curtain of the digital audio revolution began.
Digital audio is a very different storage mechanism. Digital music files usually exist in the form of pulse code modulation (PCM), and the amplitude of the analog signal is measured with an equally spaced clock signal and replaced by a binary number. Amplitudes are represented as binary numbers (1 and 0), and the number of bits in that number is often referred to as bit depth. The measured time interval is called the sampling frequency. When the standard cd is recorded, 44100 samples per second are taken. Each of these signals is measured with a 16-bit precision, storing the result as a 16-bit binary number. On the other hand, if you want to record high-resolution music, you will take a bit depth of 24 bits, and the sampling rate will be 192,000 times per second (192khz).
Digital audio data can be stored in a variety of sample rate, bit depth, encoding, and compression formats, but no matter how it's done, it's the DAC that makes sense to these digital signals and converts them from their binary format to analog signals as accurately as possible.
Why do you need a separate DAC
While each decoder has a DAC circuit, it's clear that not all DACs are the same. Poor digital-to-analog converters can introduce noise during playback due to poorly designed circuitry, and they may not support all sampling frequencies, not to mention additional distortion due to jitter.
The jitter mentioned here is the numerical timing error. Digital-to-analog conversion requires a high-precision clock circuit to generate a high-precision clock signal. If not done correctly (usually due to a poorly designed digital clock circuit), conversion performance can be compromised. This jitter problem arises in each digital-to-analog conversion. In recent years, we have seen asynchronous DACs gradually increase their position in the market, even replacing the function of computer clocks.
Clocks in dedicated hi-fi DACs tend to be more precise than those used in ordinary PCs, so usually the sound will be better.
Audio files are everything
Of course, to get the best sound quality from the dac, you need to have good audio files – don't expect to get good sound from a 128kbps mp3 file. In fact, this kind of compressed signal has more obvious disadvantages under better decoding. Files stored in flac, wav or alac (mac) lossless pcm format are usually the best audio files, the best results you can hear the sound, and the cd quality of the same format is also very high.
DSD and pcm
DSD, or direct stream digital, is an alternative to pcm and was originally a format for super audio cd (SACD), provided by Sony and Philips in the late 90s and early 20th centuries.
Unlike pcm, it provides a bit depth of only one bit, but has a much higher sample rate. For example, dsd64 has a sampling frequency of 2.8 mhz and dsd128 has a sampling frequency of 5.6 mhz. The debate over which coding system is better continues. If you insist on choosing dsd, then be sure to first determine if your dac supports it.
Which DAC is right for you?
DaCs come in a variety of shapes and sizes, and offer different input interfaces and functions, so in addition to determining your purchase budget, you need to learn how to use it.
The compact USB DAC is advantageous at a reasonable price. They are usually no larger than usb sticks and can be connected to a computer via the USB interface. They use the USB interface to power them, so no additional power supply is required. However, USB DACs are convenient to use, but usually only have a headphone jack and line level output that allows it to hook up to an active speaker or other hi-fi system.
If you need more interfaces and don't want to take your device with you, a desktop DAC might be a better fit for you. These devices are usually large and require independent power supplies, but usually provide several additional interfaces. If you want to use headphones, be aware if they come with a headphone amplifier, as not all DACs offer this feature.
Finally, there are some DACs that are designed as part of a home audio system. These will usually have more input interfaces (especially the aes/ebu interface) to support more functionality, support music formats for all sample rates and provide Bluetooth connectivity. Some will even have integrated volume controls so they can be used as pre-equine.
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