I have a Macbook Pro (13" Mid 2009 model). My 3.5mm analog headphone jack has stopped working. It produces sound but with a lot of hissing and at a volume that is 1/10th of what it used to be. Also if I crank up the volume really high I can notice that the lower range of the spectrum is not being reproduced and only some mid frequency's are being reproduced. The in-built speakers on the other hand are just working fine without any problems. I wanted to know that if I buy a DAC(Fiio D3) which utilizes a Optical output, will my system be able to output that through the jack, seeing that both the analog line and digital line share the same port? I cannot test it with an optical out as I don't have the required products with it. Is there any way of checking if it works? I'm not able to access any system which utilizes a digital out. As my system is out of warranty what will be the expected cost if I get it done/checked at the customer service center?