Why not just get a Raspberry Pi with a HAT card, and connect that to your Caiman Seg, you can stream to the RPI using Volumio with mobile phone or tablet or computer.
If you have a computer with a music library you can map to that over wifi using Volumio to play your digital music.
You can hook up to the Caiman Seg from TV using optical sound out or digital coax (if it has it), and optical/coax from CDP if it has it, you can even us USB from computer to Caiman SEG
This is how I use mine and get very good results, if you have not got a Dorado battery power supply from Beresford you might want to invest in one if you like the above as it improve the sound quite a bit.
Have a look at
https://www.hifiberry.com/shop/bundl...digi-bundle-4/ it works out to about £114 all in for RPI4, HIFIBERRY DIGI+ PRO, PSU, Micro Card and connection block. You might want to consider the HIFIBERRY DAC+ DSP combines a Burr-Brown DAC as we’re using it in our DAC+ Standard and Pro series with a an digital input and output and a powerful Digital Signal Processor and is on £28 more.
It will certainly get you started and without changing amplifier, unless you want to.