USB stands for Universal Serial Bus which is used to connect peripherals to computers. USB is used for data transfer, audio, power delivery and more. The USB standards group has released three major versions of the standard.
In our daily lives, we use USB to charge all kinds of devices. The mouse and keyboard on your computer probably use USB interfaces in one way or another. We synchronize or transfer data between devices such as printing or file transfer to disk drives. The USB "stick" is another regular use case.
The universal aspect of USB does mean complexity. One example in the head picture of this post is the Chord Mojo DAC/Headphone amp. There are two Micro-USB connections on the Mojo. One is for power/charging, and the other is for data transfer to the DAC.
What I am here to talk about is USB audio. I am going to "gloss over" this subject as it is just too extensive. There are links below for further study. The USB standards group has released three variants of USB Audio. Almost all of our USB DACs use USB Audio Version 2.0. On macOS and Linux you usually do not need drivers; on Windows, drivers are almost always required.
The technology used to transfer audio between the computer and the DAC is NOT the same as transferring data files to a disk drive. Errors in this process that can and do influence/corrupt the audio data. It is an imperfect transfer mode.
Some of the factors that can cause issues in USB audio are listed here:
- Electrical noise from the computer
- Interference in the cable
- Grounding issues
- Imperfect clocking or jitter
Even with these issues, USB audio is one of the most used methods of getting digital or file-based audio to the DAC for audio playback. You can spend a lot of money in a system to up the odds of delivering better data to the DAC.
As I said above, there is a LOT more to talk about USB, and this is not exactly the right place for extended discussion it is an introduction!