Does iPhone have DAC?
DACs are built into Apple devices like the iPhone, but they are only mid-range DACs that max out at 24 bit at 48 kHz. Apple's Lightning to 3.5 mm Headphone Jack Adapter has a DAC, but it likely maxes out at the same bit depth and sample rate. via
What are the different types of DAC?
There are basically four types of Digital to Analog Converter circuits namely:
Does DAC make a difference?
TL;DR Rather loosely, a better DAC more accurately performs the conversion. Whether an expensive DAC provides an audible quality difference is debatable/subjective, but it's not likely to make a difference, unless you specifically want a DAC that "colors"/distorts the sound. A DAC is a Digital to Analog Converter. via