IPhone/IPad - why do I need camera adapter to connect to DAC?

My understanding is you can use any lightening to USB cable, but I’ve only used a camera adapter so not sure if they all work or provide sufficient data transfer rates.  I have also heard the Apple Camera Adapter with the power port sounds a bit better but I haven’t confirmed this.  They’re not all that different in price so unless size is a factor I’d just buy the powered version.  I did buy a cheaper 3rd party cable with the power port and I found it sonically inferior to the base Apple CA without power port.  I haven’t looked but I have to believe there are higher-end lightening-to-USB adapters that sound better than either Apple cable, and that’s the direction I’m going next and will report back with any findings. 

As as far as your side question, I have no idea.  I know my AQ Dragonfly Red sounds better than the iphone’s or ipad’s DAC as one would expect.  My priority is sound quality, so I don’t buy Apple ‘phones of any kind and never looked into what DAC they use or where.  Hope this helps. 

Thank you for reply.

My question is “do I have to use Camera Adapter when I can directly connect iPhone to DAC by Lightning-USB A/B?”

From my basic understanding, less device, shorter case should sound better. So, using camera adapter (more device), so making the total sound travel distance longer(longer) seem counter-intuitive.

I thought that one of followings might be the reason.

1) due to certain Apple’s certain technical restriction, I can’t simply use a cable alone to bypass apple device’s internal DAC

or 

2) Camera Adapter has some sort of sound enhancing device.(?)

Have you tried connecting Apple device to external DAC without using Camera adapter?

In case of Dragonfly type DAC (Audioquest) I can see why I need a camera adapter simply to avoid error message. But in case of other self-powered external DAC, I do not understand why I need to go through camera adapter kind of external accesory.

Because Apple thinks you don't need it. 

If your DAC supports Apple AirPlay2 (like my Matrix Mini-i-3 Pro) use that wirelessly. I was surprised how well that works. I think the wireless maybe better because the noise of the phone is not directly connected to the DAC. I am not an expert in Apple crap but I am just using AirPlay2 temporarily until my DAC is ROON READY.

I think I will need a streamer. The DAC I happen to like it doesn’t have streaming function.

I like AirPlay2, and since I don’t have any better source than CD, the quality is just fine. 

I’ve been thinking about Roon, but simply doesn’t want to do any sort of subscription yet.

I believe the iPhone/iPad does not have enough electricity as a source. With the camera adapter the charging cable would support enough power to drive the iPhone.

When I connect the iPad to my Oppo 205, I use the Apple AV adaptor. Then use the HDMI cable plus the charging cable to make it work.