Introduction

Integrated into the motherboard and already present in every computer, a sound card is one of those pieces of hardware most people don't think about buying. In addition, owners of exceptionally cheap speakers, headphones, and headsets have little reason to invest in a discrete sound card as it will not bring them any significant benefits over an integrated solution.

Before moving forward with this educational article, let me be very clear: Not all integrated sound cards are horrible. Higher-quality motherboards usually come with better integrated sound cards, ones that have cleaner (less noisy) inputs and outputs, provide more power to the headphones, and offer more software features. However, there's still a lot to be gained from upgrading to a proper external USB sound card.



The computer case interior is a catastrophic environment for a sound card because each component can and will cause noise and electromagnetic interference, which negatively impact the proverbial "purity" of the audio signal, degrading the overall sound quality in the process. One of the more obvious examples is microphone background noise, which often appears when connecting a gaming headset to your computer's integrated sound card. Unaware that it would disappear entirely if the microphone were connected to the input of an external sound card, most users attribute the audible hiss and static noise of the microphone to the poor quality of the microphone itself.

A noisy microphone will not only make it difficult for your friends on Discord to understand what you are trying to tell them, but also creates problems with using such applications in the so-called voice activation mode, where the microphone is activated when you speak and automatically turns off when you're silent. If the microphone input has a lot of interference, it will be nearly impossible to adjust its sensitivity such that it seamlessly activates and deactivates when it should. As a result, you'll inevitably annoy your virtual comrades and end up having to use the so-called push-to-talk mode, which is both awkward and strenuous as it requires pressing the assigned key every time you want to say something. A possible solution to this problem is to buy a USB gaming headset (based on microphone quality alone, my recommendation and personal go-to choice is still the excellent Creative SXFI Gamer). However, should you want to keep using the headset you already have while getting the best possible microphone and sound quality with your upgrade, a proper external USB sound card is the way to go.

In this article, we'll first go over the critical parts of the digital audio chain. Then, we'll tackle some common misconceptions that constantly confuse those not entirely at home with DACs, headphone amplifiers, sound cards, and everything in between. Finally, I'll recommend three excellent USB sound card options, ones that have proven themselves in real life and I'm personally using on a daily basis.

Full disclosure: This article is sponsored by Creative, but thoughts and opinions expressed in it are 100% my own. It is written to be as informative and educational as possible, and accessible even if completely new to the world of digital audio. US-based TechPowerUp readers can take advantage of a 15% discount for the Creative Sound Blaster X4, Creative Sound Blaster GC7 and Creative Sound BlasterX G6 mentioned in this article, as well as all other Creative's external and internal sound cards, by using the POWERUP15 discount code in Creative's online store until July 31, 2022.

The Audio Chain

When we want to listen to some music, we click on the desired song, and it starts playing through our speakers or headphones. Have you ever thought more deeply about what happens in the background? What series of events has to occur for a digital audio file—a bunch of ones and zeroes—to transform into physical sound waves our brain then receives through our ears and interprets as sound? Let's go over the process.

Digital-to-Analog Conversion

First, your file has to go through digital-to-analog conversion. The audio signal can't be amplified or played back unless it's in an analog form, and that's where a digital-to-analog converter (DAC) steps in. A DAC is a chip that takes a digital file, "reads" it in its digitally sampled form, and turns it into an analog waveform corresponding to the digital samples contained in that file. The more digital samples an audio file has, the better a digital-to-analog conversion can be achieved. That's why one of the key technical specifications of a DAC chip is its maximum sample rate—the number of samples of data taken in a second. The sample rate is expressed in kilohertz (kHz). When it comes to specifications, we also look for bit depth—the amount of data recorded per sample, expressed in bits. A standard modern-day DAC should be capable of handling at least 24-bit/96 kHz audio files.


Here we're talking about Pulse-Code Modulation (PCM) audio files. PCM is the de facto standard non-proprietary digital sampling method in which samples are taken regularly at uniform intervals. Most if not all music files on your PC (MP3, OGG, FLAC, WAV, and AIFF), as well as almost everything you play from your music streaming service of choice, are sampled using PCM. The story is quite different with Direct Stream Digital (DSD) audio files, which are a result of a pulse-density modulation, as well as other "audiophile" audio compression formats, such as the controversial Master Quality Authenticated (MQA) available to Tidal HiFi Plus subscribers. While PCM digital audio files are supported by any device that can play music, DSD and MQA support is limited and device-specific.


The optimal bit depth and sample rate of PCM audio files is a subject of constant debate between audio enthusiasts (along with just about everything else). Some will easily discard a DAC that can't work with bit depths and sample rates higher than 24-bit/96 kHz. In reality, most users won't benefit from their DAC being capable of working with higher bit depths and sample rates because they'll never play an audio file recorded in such "quality." Even 24-bit/96 kHz is a stretch for most. For example, your Tidal HiFi or Apple Music subscriptions you're probably using because of their high quality max out at 16-bit/44.1 kHz. This isn't a drawback, though, as the fidelity of a 16-bit/44.1 kHz audio file is generally considered "CD quality" and high enough to reproduce all of the frequency and dynamic range an average person can hear.

Bit depth isn't to be confused with bitrate, a value that tells us the number of bits processed per second. Out of all numerical values describing the "quality" of an audio file, bitrate is probably the one average users are most familiar with. This dates back to the glory days of MP3 files when everyone knew that a 128 kbps bitrate song would sound much worse than a 320 kbps one. Nowadays, music streaming services offer 160, 256, or 320 kbps streams in their lossy subscription tiers, with the lossless (HiFi) ones going up to 1,411 kbps.

While we've only scratched the surface of digital audio file conversion, it's time to move on to the next step of the process: analog signal amplification.