'Strain' on the computer is rendered irrelevent by the use of a USB Galvanic Isolator:
http://electronics-shop.dk/galvanically-usb_isolation
and a DAC which uses Asynchronous USB.
Beware some dodgy manufacturers (and I'm including some big names here) who work the word 'asynchronous' into their marketing drivel in devious ways. Their DACs might, for example, have asynchronous sample rate conversion (ASRC). This is completely unrelated to Asynchronous USB and is in any case not desirable. Sample rate conversion should be synchronous for best results. You might see weasel words like 'asynchronous signal processing' which is ambiguous meaningless bullshit. If it doesn't say 'Asynchronous USB' then it isn't and is best avoided.