When is the Apple Camera Adapter necessary?


I understand that the Apple Camera Adapter is necessary to connect an iOS device to a DAC with a USB-B input. (iOS —> camera adapter —> USB-A to USB-B cable—> DAC) But is the adapter necessary if the DAC has a USB-A input? For example, if I have a DAC that has an USB-A input, can I plug in an iOS device with the same lightning to USB cord that I use to charge it? (iOS —> Lightning to USB-A cord —> DAC) Or does the Camera Adapter do something to allow the DAC to extract the digital audio signal? I’ve looked on other websites such as iFi Audio and they are rather ambiguous about this subject. Thanks for the help!
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Showing 3 responses by saintsaens_op61

So I did some more digging and I found these pictures on the iFi website. Does this mean that the camera adapter is unnecessary for USB-A DACs, or is this just marketing?

https://ifi-audio.com/a-perfect-match-iphone-6-plus-micro-idsd/

@soix that make sense. Thanks guys. 
So now I’m confused again. The iFi website isn’t ambiguous, it’s contradictory. They have a picture of a iPhone connected to one of their DACs with a regular Lightning to male USB-A cable, but they also have this user manual: https://ifi-audio.com/wp-content/uploads/2018/07/nano_iDSD_BL_Manual.pdf (read the first bullet point). This is the only time that they have explicitly said that the regular charging cord won’t work.