Gabuli, sorry, but I'm having a little trouble understanding your last question. Let me try anyway to offer some helpful thoughts. The Sophia's are 87dB efficient with a minimum impedance of 3.1 Ohms. The Plinius is rated for 220 W class A into 4 Ohms, so I would expect it ought to be able to drive and control the Sophias without difficulty. The Cary's deliver 1000 WPC into 4. You have a bit more power with the Cary, but it is class A/B power. I have not heard the Plinius 103, but it is a well regarded amp. As much as I like my Carys, it is really hard for a class A/B amp to play in the same league as a good pure class A amp like the Plinius.
This is why I questioned if the unpleasant sound might be due to your Cary CD player. I haven't heard that player, but someone whose ears I trust told me that "Cary should stick to tube amps" after an audition with the 306 Pro.