Optical.glass into plastic socket

Hi,I have a ar dac3.The optical  cable I have is glass and will only fit into the plastic optical socket.It sounds ok.is that likely to give me any problems. Thankyou
What do you mean by plastic socket?  Toslink i presume?
If your optical cable is a toslink with  glass fibers plugged into a toslink receiver on your dac, then you are ok.
The toslink receivers on electronics are really meant to work with aperture matching plastic fibers, but as long as your glass fibers are not fractured, it should not cause any issues.