There are a few items that can cause this. Old CDP laser, DAC, and preamp mostly. Replacing something as simple as the CDP laser can add clarity and separation. Your DAC can also be the issue. Preamps especially tube preamps can cause clarity issues especially if there are caps in the signal path. Caps sound different. Some are musical, some have better clarity, some can offer a mix. I would start by replacing the CDP laser if your CDP is an older model. This can be a simple cheap fix.
Happy Listening.
Happy Listening.