I’m still learning my way around audio. Swapping equipment has helped me understand how sound is converted, and I’ve gathered those lessons into a “Three-Part DAC Special Series” for other beginners.
Audio is a broad subject with plenty of knowledgeable people, so I approach it cautiously. If something needs expanding on, or you have more experience with a topic, I’d welcome your input. Sharing what we know and learning from one another is part of the hobby’s appeal.
Press play on a phone or computer, and you start a sophisticated chain of signal conversion.
Sound begins as a physical wave: changes in air density. This guide follows how those analog waves become numbers, the familiar 0s and 1s, and then return to physical energy that moves our eardrums.
A Beginner’s Guide to DACs: 3-Part Series
- Part 1: What is an Audio DAC? The First Gear to Buy When Sound Feels Dull
- Part 2: A 1-Minute Guide to Decoding DAC Specs for Beginners: 24-bit? SNR?
- Part 3: Which DAC Should I Buy? A Key Chipset Guide to Finding Your Sound
Recording an Analog Wave as Numbers: ADC and PCM
Before a performance can be stored as a file, its sound first has to become electricity. In a studio, the microphone receives the sound waves and translates them into tiny changes in voltage. The signal at that stage still follows a continuous wave. The ADC (Analog-to-Digital Converter) takes over the next part of the job: dividing that continuous signal into closely spaced moments and recording the measurements numerically. This is the step that turns the performance into something a digital system can store, rather than a physical wave that exists only as it is played.
Gemini. Analog → Digital → Analog
Think of the ADC as a camera taking tens of thousands of burst photos of a moving person every second. Play the frames back quickly and they appear to move continuously. PCM (Pulse Code Modulation), the most widely used digital audio format, works on a comparable principle. It’s the basis of familiar WAV and FLAC files.
Wikipedia. Comparison of analog and digital recording
The image above uses 4 bits (2^4) to illustrate the process: blue sampling points represent the red signal. With 24-bit high-resolution PCM, amplitude is divided into approximately 16 million (2^24) possible levels. Organize those measurements in order and you have the data that makes up an audio file.
What a DAC Does
The DAC (Digital-to-Analog Converter) is the subject of this three-part series. Its name describes its job: turning Digital (D) information into an Analog (A) signal.
It takes the audio stored as binary 0s and 1s on a computer or phone and turns it back into a continuous electrical waveform. That waveform can then become sound. DACs are already working in more of our everyday devices than we tend to notice.
(Left) Daiso Mall. Aux to C-type Adapter, (Right) SoriShop. Wadax DAC
The range of products hiding this conversion process is enormous. At one end is a 2,000 KRW earphone adapter from Daiso; at the other is a high-end home audio system costing 200 million KRW. The professional audio interface a musician uses for recording belongs in the same discussion. Their cases, prices, and intended uses could hardly be more different, but the essential conversion has the same purpose. Looking at the outside alone can obscure the fact that these devices share that basic task.
(Left-Bottom) SMSL DS20 Portable DAC/AMP, (Right-Top) SMSL DO400 Stationary DAC/AMP
I once saw someone in an audio community insist that an iPhone C-type earphone adapter wasn’t a DAC. If an adapter receives digital audio through USB-C and sends it to analog earphones, though, a small DAC inside has to turn that data into an electrical audio signal.
Whenever an electronic device plays sound through its own speaker or connected earphones, a DAC is generally doing that conversion somewhere along the way.
Following the Connections: Digital In, Analog Out
Understanding that conversion makes a DAC’s ports easier to follow. The ‘D (Digital)’ side accepts the incoming data; the ‘A (Analog)’ side sends out the converted audio signal.
The signal travels in one direction through the DAC:
- It arrives through a digital connection such as USB-C, USB-A, optical, or coaxial.
- It leaves through an analog connection such as RCA, XLR, or 3.5mm/4.4mm.
“Can I plug a C-to-C cable into a DAC to listen to speakers?”
This is where the connection types matter. The USB-C connection is the digital (D) path, rather than an output for the analog (A) waveform. Keeping that distinction in mind helps avoid a common cable mismatch.
“Can I unplug a cable from a DAP’s 4.4mm terminal and plug it into another DAC?”
The same distinction answers this question. The device’s 4.4mm connection has already produced an analog (A) signal. That cannot simply be fed into another DAC’s digital (D) input.
For these connections, follow the direction from the digital cable into the DAC, then out through an analog cable.
Why Buy a Separate DAC?
Why use a DAC at all?
If a phone or PC motherboard already includes a DAC, why spend hundreds of thousands of won on a separate box? That was one of my first questions in the hobby, and it stayed with me for a while. After trying different equipment, I see three main reasons people seek out a standalone DAC.
Precision and accuracy
Basic DACs can introduce small distortions during conversion or struggle to reproduce the waveform within the chipset’s processing limits. Higher-performance designs use precise clock components to convert the signal accurately, with smoother, clearer contours to the sound.
Tech Insights. Samsung Galaxy S10-Teardown
Isolation from noise
Look inside a phone or PC and the potential sources of interference are packed closely together: CPUs, GPUs, memory, and wireless communications hardware all occupy the same small space. Those components generate electromagnetic interference (EMI) and radio-frequency interference (RFI). The analog audio signal is vulnerable to that electrical environment, which can show up as background hiss or less distinct boundaries between instruments. Separating the conversion hardware is one reason people turn to an external DAC. A desktop or portable unit with its own power supply can house the circuitry independently and feed it cleaner power. The design is devoted to converting sound, rather than sharing its enclosure with the rest of a general-purpose computer. A quieter background is the aim of that physical separation.
Tone and texture
Chipset design and the analog output stage can also give a DAC a richer, denser character beyond the basic conversion. Faithful decoding of lossless high-resolution files remains a fundamental requirement for Hi-Fi equipment.
DACs and Amps Do Different Jobs
Portable dongle DACs often combine the converter and amplifier on one small board. Some mobile chipsets integrate both functions in a System-on-Chip (SoC). That packaging makes it easy for a beginner to assume a DAC and an amp are the same thing.
The two jobs are distinct, and understanding the difference makes the specification sheet much easier to read. Think of the DAC as the brain: it interprets the digital information and turns it into a small electrical audio signal. The amplifier is the muscle that receives that signal and increases it enough to move a speaker diaphragm. Putting brain and muscle on the same board doesn’t make them the same function. It simply packages conversion and amplification together, which is convenient in a small portable device. Keeping the roles separate in your mind helps explain why a product description may discuss both a DAC chipset and an amplifier circuit.
The Cirrus Logic CS43131 is an example of a chipset with an amplifier built in. Combining the stages reduces the number of parts and the board area needed, helping manufacturers build a compact device. The related CS43198 shares the DAC side but leaves amplification separate, providing a line output instead. That gives the device maker more freedom to design an independent amplifier circuit elsewhere on the board. The distinction is therefore about how the product can be put together, not simply about two nearly identical model names in a catalogue.
(Left) Fiio. BTR13, (Right) Fiio KA15
Fiio offers a useful comparison. The CS43131-based BTR13 doesn’t list a separate amplifier chip. The KA15 uses the CS43198 and emphasizes its separate SGM8262 OP-AMP rather than an internal amp. In other words, it separates the conversion and amplification jobs to create a more specialized arrangement.
The Gateway to Sound
Follow the signal like this: ‘Source file (data) → DAC (conversion) → Amp (amplification) → Earphone (sound).’
The DAC is where the stored 0s and 1s first become an analog waveform again. How that conversion is handled affects the clarity and texture we hear. For me, the urge to keep swapping DACs comes from wanting to hear even 1% more of a recording’s subtle decay and sense of space, beyond simply making it louder.
Part 2: Decoding DAC Specs (Preview)
Understanding the DAC’s role is a start, but shopping still means facing a long list of unfamiliar figures. In Part 2, I’ll explain what those specifications mean and how they relate to the earphones you actually use.
