How to output sound from two sound cards at the same time?

Question

Audio

There is a standard Realtek chip on the motherboard, you need to output it to the speakers, and there is a USB sound card (the cheapest, Chinese), you need to output it to the headphones. All this should work simultaneously , so as not to switch constantly, because. I will use constantly. Is it possible to implement this?
Thank you.

Answer 1

Maybe you can solve the problem with a virtual cable
software.muzychenko.net/eng/vac.htm