does MacBook Pro need a DAC?


Not an engineer with a basic question. Just got a new MacBook Pro. It has AudioMIDI setup with format up to 96k hz.
I am using it by plugging in a cable into a headphone jack with the other end going into the receiver. A friend suggested I get a DAC. but I don't see what purpose would an additional DAC serve. Isn't my MacBook Pro already converting digital to analog signal? and is it doing it efficiently? enough for high quality reproduction? thanks in advance to all who respond
petar3
Oh, hell yes...
 you. Definitely need a DAC for Mac Book Pro myself I’m replacing my PS Audio DAC III
with either a Schiit Audio Gungnir or if I can get my hands on Denafrips Ares II DAC
both are R2R DACs.
As many have stated a DAC will make for a significant improvement. Evan a simple USB driven one such as the Audioquest Dragon fly models or even a Schiit Modi 2. 
If you want to use the Mac port as a toslink connection, you will need to buy a miniplug extender for your toslink cable or buy a new toslink to miniplug cable.

if you want anything more than background music, you will need to use an external dac. As with most components, the better dacs will cost more.
quick comment: there is talk here of the headphone jack being optical as well. Maybe, maybe not, either way don;t use it. Toslink is merely the optical version of SPDIF. It has some disadvantages - limited to 96 kHz, and very jittery. Since you have USB, use that instead. Toslink is the last choice for great sound.