The audio output in the MacBook Pro now recognizes which impedance the model used has and adjusts the output voltage accordingly: resistances when driven by the signal voltage. There is also an interesting new feature for headphone users: headphones come with different impedances, i.e. This is called High Resolution Audio in audio circles. In addition, the DAC supports up to 96 kHz sampling frequency. So, while the port no longer offers an optical output like previous examples, Apple claims that the internal DAC (that is, the analog-to-digital converter) is so good that you can feed the analog signal right into your stereo. However, on the latest MacBook Pro model, this port has learned a few new tricks. Apple has also improved an output on the new MacBook Pro that was actually thought to be dead, since it has not been found on iPhones for a long time: the 3.5 mm jack output.
