Does USB cable length affect sound quality?
The longer the USB cable, the greater the chance of signal degradation through the resistance of the wire. This is why many manufacturers are switching to better, more high-quality conductors. Just for reference, the USB 2.0 spec limits the length of USB cables to 5 meters, while the USB 3.0 spec suggests 3 meters.
Can USB cables be used for audio?
USB audio is a digital audio connection used to send digital music from your computer to a digital to analogue converter (DAC). But why would you use this instead of other outputs? Let us enlighten you. The reason why many people choose USB audio is due to the poor quality built in DAC in a computer.
Is optical or USB better for DAC?
It doesn’t matter. Both are digital signals so in terms of audio, they will be virtually identical. There might be some very small differences in jitter but that won’t matter. If they aren’t identical then USB will most likely have the very slight edge (if async mode USB is used).