USB 2.0 External Sound Card 6 Channel 5.1 Surround Adapter Audio S/PDIF for PC -Blue

When obtaining simple USB to single analog adapters, check, whether they are outputs (DAC) and not inputs (ADC). Or better look for a fully functional decent external soundcard / interface. If you prefer the DAC of the receiver, you can use an external soundcard with digital outputs for your PC. They usually are rather optical than coaxial, functionally the same: https://www.amazon.com/Optimal-Shop-External-Channel-Surround/dp/B00Q4WQ7XW/ref=sr_1_18 One more option -- split the audio from the HDMI output of the PC. No idea about the iPhone, except of a BT receiver.

The problem with higher sample rates is that you don't get more bandwidth, like you'd expect. They win still have ADC anti aliasing filters and DAC reconstruction filters with cutoffs at 20kHz or so. You do get some improved dynamic range (lower quantization noise), though that may not be realized with all devices because of other specs. I've had good success with this one: https://www.amazon.com/dp/B00Q4WQ7XW And this one (not available, but you can probably find identical ones by searching): https://www.amazon.com/dp/B07VSHCGWD? I can't remember if they do 96kHz sampling or not, but HF works fine at 48kHz rates, especially if you're using an IQ tap situation like with the G90.