I just received the Apple USB-C dongle that I ordered on the UK Apple Store.
I did a few informal measurements on it, just to make sure I didn't get a weird variant. My results generally agree with amirm's. I measured an amazing 0.5 Ω output impedance, yay!
Hey, does anyone know if there's been some sort of silent update to apple's usb c to aux adapter? I bought one when they first started getting sold in stores, and found that it was quiet as hell playing off my pixel. Eventually I lost that one so I went and got another which get to a decent volume off my pixel at ~40%. At first I thought there was a driver update of some sort, but then I found the original, and it seems like they might have silently release a new version of the dongle
Sadly, the one I just bought (ordered 2019-02-18 on online Apple Store UK) still suffers from this gain issue with Android phones. I measured a paltry -26 dBV (0.05 Vrms) max output with my Pixel 3, which is way too low to be usable with anything other than very sensitive IEMs.
When using the dongle with Windows, it's the same output level initially, but that's because the default gain is -20 dB. In Windows you can adjust the gain, and get it up to -6 dBV (0.5 Vrms) max output, which is more reasonable. Sadly, in Android it looks like it's stuck at its default gain of -20 dB with no way to adjust it. That really sucks, that dongle would have been perfect for Android devices otherwise.
(By the way, the maximum output level I could measure when using the dongle with Windows was 0.5 Vrms, but amirm measured 1.0 Vrms. Not sure why I'm getting a different number there.)