I have the symphony ii+ with Bose (silver knobs, no tape deck), no Bluetooth
Music source is iPhone 6

Currently have my own auxiliary cable wires into the back of the deck and recoded the deck to run auxiliary input. Tried a few different cables, don't like the sound quality.

Will this cable work with my symphony ii+, and give me better sound via using the usb connection instead of auxiliary?
http://enfigcarstereo.com/ENFIG_AI2_IPDU_AUX.html

I don't need radio to control music from phone, do not need Bluetooth and do not need text in dash cluster.
Just looking for better sound connection
Thanks
I've called and emailed enfig, just feeling too impatient waiting to hear back
Thanks