Can confirm this device, https://www.amazon.com/dp/B005LXGGM2/ (Andrea Electronics C1-1021450-1 model USB-SA-1 High Fidelity External Digital Sound Card with Noise Reduction Technology) does work with 2017 iMac USB ports and mics, headphones, and mic/headphone headsets using 3.5mm audio jacks. Currently am using "PC" headsets with this adapter, which is just another way of saying headsets with 3.5 mm audio jacks. Sure wish iMacs came with 3.5mm mic and audio out jacks.
Posting this because, like other iMac users, I've occasionally had trouble with USB-terminated audio devices, especially mics, giving noise and feedback. It may be a somewhat-obscure issue for some of us, but it's been around for a long time. Even having an issue with an Apogee mic and my new 2017 27-inch iMac, sounds like tons of grounding noise and I simply cannot troubleshoot it; I think it's the mic.
But no issues with this USB-to-3.5 mm adapter, no noise on either line (mic line in; 2-channel stereo line out) and clean sound.
Posting this because, like other iMac users, I've occasionally had trouble with USB-terminated audio devices, especially mics, giving noise and feedback. It may be a somewhat-obscure issue for some of us, but it's been around for a long time. Even having an issue with an Apogee mic and my new 2017 27-inch iMac, sounds like tons of grounding noise and I simply cannot troubleshoot it; I think it's the mic.
But no issues with this USB-to-3.5 mm adapter, no noise on either line (mic line in; 2-channel stereo line out) and clean sound.
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