Dac's Amplifier Vs Allo Boss

Hi friends. I have the amplifier Rotel A12 which has a Wolfson DAC, model WM8740SEDS.
Today I have a Chromecast audio connected by optical cable to the amplifier, so I’m using the DAC amplifier.
In my house I have a raspberry 3.
If I bought a raspberry’s DAC like Allo Boss (or another), will be the audio quality improved? Or instead the DAC of my amplifier is already a good solution?
The last question: if you think that the DAC of my amplifier is already a good choice, if I bought a spdif output board for raspberry like hifiberry Digi+ (or another) to replace the Chromecast audio that I’m now using, could I have an improvement?
Thank you very much
Good music

I guess the Dac of your amp is quite good. But I don’t know if it is supported by Volumio…
Second point, the usb implementation of the RPI 3 is not good. You may experience glitches.
So using a i2s dac is a good way or using a Rpi4 or thinker board to feed the rotel.

Ok. So I haven’t to buy a dac board for Raspberry gpio because my amplifier dac Is good, have i good understend?
And so, I can buy a spdif output board for Raspberry gpio and connect It with optical cable to my amplifier, correct? But i have to change rpi3 with rpi4?

In this way, Will I have a quality improvment compared with Chromecast audio that i’m using now?

Your Rotel has USB input, so why not use that? Don’t worry too much about jitter, glitches, etc. When something is broken signal wise, you will most probably here it.

Just connect your pi via usb and enjoy the music. If you feel there is missing something, than feel free to change to spdif or whatsoever. I wouldn’t expect any changes though when using the same dac.