Toslink vs Coax...

I have a Cambridge Audio CXA80 ( 120watts/2 at 4ohms) driving Dynaudio  DM 3/7 towers. My source is blue tooth from my iPhone, Pioneer streamer N-30, as well as a Wadia 171i transport that by passes the DAC in the phone to go directly into the upgraded DAC that my Integrated Amp comes with. ( I have a Cambridge Bluetooth dongle plugged into the amp for Bluetooth)
I also have the entry level KimberKables  braids for  speaker wires, and a Shunyata venom conditioner plug in a low cost powerstrip without surge protection( the Shunyata covers surge and conditioning so no power is lost from a power strip with surge protection.)
 I think my set set up sounds really good but the iPhone plugged directly into the Wadia that is directly into the amp only sounds slightly better than the blue tooth option...

So my question is , would the sound quality of the Wadia/ phone/amp  connection be significantly..... improved with an expensive( for me) coax cable like the Audioquest Carbon ($160 range) that has 5% silver along with other amazing construction designs; instead of the $60 Kimber Toslink I’m using now? I have read some compelling opinions in favor of mid grade coax vs  Toslink for digital connections, but wanted to get some Audiogon peeps weighing in on the benefits of this potential upgrade.
(I do I have my 1 st power cable upgrade from stock PC on the way , an Audioquest NGR 3Y that will be plugged into my amp to the power strip.)

Thanks for  your thoughts.
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I tried a few different cables when I had an outboard dac. I liked and used the Wireworld starlight 8 coax cable ( red one is around 125.00) and the Gold which is 250.00.  In your case the red would be the way to go.  Open, airy and wonderful bass. 
 Buy a bluejeans coaxial cable. Pics of money you saved and put it towards a blue sound no to. That will sound much better than your phone! 
Oldtiger thank you for your resposnse.  I do have a hifi account with Tidal, so my phone is technically CD quality when it’s tapped to the Wadia transport.