Just hook up the MacBook Pro to the USB on the back of the DAC section of the amp. It is not the best way to go buy for a garage that would be OK. For my office I use much better streaming approaches and do not let the computer touch the DAC section.
With Sennheiser’s HDVD 800, sound is perfect. The HDVD 800 is able to connect with digital sources and is equipped with a high-quality Burr-Brown digital/analog converter (DAC) that converts digital audio data into analog signals with a resolution of 24 bits and a sampling rate of up to 192 kHz. This enables the HDVD 800 to transmit the entire frequency spectrum of high-end audio sources without any loss of frequencies.
In addition to the symmetrical inputs, the HDVD 800 also has an asymmetrical input socket; incoming signals are symmetrized before further processing takes place. Digital sources can be connected to the rear of the unit via an XLR (AES/EBU) input, optical and coaxial (S/PDIF) digital inputs or USB. All digital inputs accept signals up to 24 bit at 192 KHz*. Designed and manufactured in Germany, this high-end, solid-state amplifier harmonize perfectly and deliver an ultimate acoustic performance when paired with any of Sennheiser’s audiophile headphones.