[LeonM]

Whats the problem with USB3 not carrying analog audio? Instead of placing the DAC in the phone, we now place it in the audio device, it makes no difference. One could argue it's better, as we now have choice in the quality of the DAC, instead of being stuck on the one in your device.

[pjc50]

The Apple 30 pin connector was introduced in 2003 when USB2.0 was all we had, and it's a right pain to enumerate a device and persuade it to start sending you digital audio over USB2. Whereas two analog pins Just Work.

Moving the audio to all-digital moves more NRE cost to the devices. It also means there's a potential for the "choice" of rubbish DACs to save cost.

[katastic]

>Whereas two analog pins Just Work.

Actually, they only work when they follow the standard physical layer. Try plugging a Line device into a Mic input, or a Line device into a speaker. Or an unbalanced into a balanced jack. It'll "work" but not "correctly."

And, just like saving money with "rubbish DACs", there's room for designing complete crap, noisey audio paths (and noisey amplifiers) in products.

If people could actually agree on a standard (USB3 seems a good choice), sending audio over a digital port seems fine.

The ONLY real problem, is digital audio isn't digital audio. It's a protocol with MANY audio formats. 44Khz. 48Khz. 96, 192khz. 2 channels, 4 channels, 7.1 channels. 16-bit, 24-bit, 32-bit float. Compressed with different compressions.

THAT'S where the real shitshow happens. Because now you're basically in the oldschool Modem situation where you have to try various standards and HOPE that the sender and the receiver both have compatible formats and in failing that, falling back to some standard required format like "stereo 44Khz PCM".

[dreamcompiler]

The number of ways analog audio can work (and equivalently, fail) is small: Mic vs. Line, Power vs. Voltage, Voltage vs. Current, and Balanced vs. Unbalanced. In practice, it's not a big problem because of connector conventions and smart signal detection.

Contrast this situation with digital audio, where the number of modes is exponentially larger by your own admission. Analog audio is more reliable.

This doesn't mean digital couldn't be more reliable; it's just that it hasn't typically been designed with the necessary metadata as part of the protocol.