I've tested USB audio adaptors, ranging from cheapies from Amazon, to a PreSonus recording interface. In fact, without resorting to really fancy measurement gea

I've tested USB audio adaptors, ranging from cheapies from Amazon, to a PreSonus recording interface. In fact, without resorting to really fancy measurement gear, an audio adaptor is close to the only thing good enough to test an audio adaptor. I've also tested the audio output of phones, built-in PC audio jack, etc. I use PC audio to test analog audio circuits that I make, so I've made it my business to know the quality of my measurements. I've also checked out the specs on the chips used in those devices. The delta sigma conversion technique is one of the wonders of the modern world. The fact is that the audio quality coming out of those devices is stunning, and probably doesn't need to be better. I can see where a recording studio might want to spend more on "overkill" to make the artifacts of their digital interface a non-issue, but for the rest of us, we're living in a golden age of audio.