Bought this to connect my Raspberry Pi 3 with 7" touchscreen to the sound system in my workshop.
The receiver / amp is an older Onkyo and doesn't have HDMI in but does have S/PDIF and Coax digital in.
After connecting the USB to the Pi I was able to select the output type, connect to the receiver/amp via Optical and play music immediately.
Sound quality is outstanding when processing MP3, FLAC or even SACD.

Only one con. I left it running all night because I hadn't set up the remote app for the Pi. When I powered up the amp the next day there was a slight hissing / buzzing in the sound output. I thought maybe it was a grounding issue so I connected the HiFi USB to the amp with a small wire. No help.
I disconnected the USB, waited 10 seconds and reconnected. Hissing was gone.
If it happens again I will connect the Pi, HiFi USB and Receiver grounds to see if that helps.
Otherwise very happy with this product.
Bought this to connect my Raspberry Pi 3 with 7" touchscreen to the sound system in my workshop. The receiver / amp is an older Onkyo and doesn't have HDMI in but does have S/PDIF and Coax digital in. After connecting the USB to the Pi I was able to select the output type, connect to the receiver/amp via Optical and play music immediately. Sound quality is outstanding when processing MP3, FLAC or even SACD. Only one con. I left it running all night because I hadn't set up the remote app for the Pi. When I powered up the amp the next day there was a slight hissing / buzzing in the sound output. I thought maybe it was a grounding issue so I connected the HiFi USB to the amp with a small wire. No help. I disconnected the USB, waited 10 seconds and reconnected. Hissing was gone. If it happens again I will connect the Pi, HiFi USB and Receiver grounds to see if that helps. Otherwise very happy with this product.