does your yamaha amp have optical in? i think a desktop should have a optical out so u can try to use that connection, (transport the digital file to ur amp to decode) .
i'm using Audinst MX1 dac/headphone amp, it does have line out and optical out. but now it is more expensive than before.
suggest u go try cheap usb dac like our local Stoner acoustics products.

This post has been edited by barjoyai: Feb 21 2017, 01:05 PM

upgrade ur motherboard then
i think ur night and day diff u said earlier comparing with the PC speaker is bcoz of ur TDL speaker.
based on my exp, DAC didnt really give night and day diff, the biggest diff being the speakers/headphone/earphones and the amplifier used.