I have a Beyerdynamic DT770 headphones and I'm using the 3.5 mm stereo cable to hook up to my motherboard. I noticed that my motherboard has both the green 3.5 mm sound output and an optical audio output. Currently I'm using the 3.5 mm output but I'm wondering if the optical audio will produce a better sound? My headphones use a 3.5 mm cable so I would have to adapt it for the optical audio. What are your thoughts on this?
Optical audio connection is just pass-through the digital signal from motherboard to a receiver. I doubt that your headphones can do something with digital input (optical). The 3.5mm jack connection of your motherboard and headphones will transmit analogue input/output. If you use a soundcard or motherboard audio solution, it will decode the digital signal to analogue signal. And there is no simple adapter, as a digital to analogue converter is needed, like a soundcard, a receiver or special converter only for this task. But that doesn't matter, as your headphone don't have digital input, only analogue input connection.