OBS being "Open Broadcaster Software"? (Full disclosure - I had to google that....)
Anyway "a lot of other things plugged in as well". What about the drivers and configuration settings for those "things"?
What do you see in Device Manager and Playback devices/Recording devices via the speaker icon (lower right screen corner)?
Could be some conflict between the devices, old drivers, buggy application software - who knows.
Can you add more explanation and some details regarding the scope of the setup you are using?