An external DAC can be of the same quality as the internal one, worse, or better. According to this site, http://www.kenrockwell.com/apple/lightning-adapter-au

An external DAC can be of the same quality as the internal one, worse, or better. According to this site, http://www.kenrockwell.com/apple/lightning-adapter-audio-quality.htm http://www.kenrockwell.com/apple/lightning-adapter-audio-qua..., Apple's dongle is roughly the same as the internal DACs on iPads and iPhones. Generic dongles purchased from Amazon can be expected to have lower quality DAC's, but most people that want to cheap out on something that only costs 9 dollars probably aren't using good enough headphones or speakers to care. People that really care about audio quality can purchase something like this, https://www.amazon.com/AudioQuest-DragonFly-Red-Headphone-Amplifier/dp/B01DFMV4NQ/ref=sr_1_2?ie=UTF8&qid=1517502600&sr=8-2&keywords=firefly+dac https://www.amazon.com/AudioQuest-DragonFly-Red-Headphone-Am..., which is higher quality than what you will find in any smartphone.