I have had the same PC setup for 2 years but a few days ago I noticed what I thought was an echo in my game recording. It turns out OBS was recording game audio from both my headset and mic with a very small delay so it sounds like an echo. I am using a set of Triton AX Pro headphones with a built in 3.5 mm detachable mic. The headphones go through an amp then into my PC with an optical cable and the mic is going to the PC through USB. I have looked all over the internet and haven't found a successful fix for this yet. I have "listen to this device" unchecked, made sure the headphones are the only output, went through the realtek options all with no luck. Any ideas?