Help finding a DAC

Hi, 

I have a PC that dual boots Mac OS and windows and in short the audio drivers for the motherboards on board audio aren't Mac compatible hence why I would like to get a external DAC. 

It has to be driverless or mac supported

Only need it for my audio technica ath-m50's

Would like it to be not too expensive without sounding like trash lol. 

Any help would be great, thanks in advance.