I find most lower priced CD players sound a little bright / harsh. This can be down to a number of things, but is a definite symptom of a jittery / noisy clock. This is often because manufacturing costs and ease of assembly dictate compromises in board layout and simplicity of power supplies.
You'll often find the clock PSU is simply the digital circuitry PSU, which on cheap CD players is also derived from the same source as the analogue PSU. A separate regulated supply with its own rectification and reservoir caps can improve things, as can re-jigging the layout of the clock and its components - usually just a crystal and a few resistors / low value caps. On the Marantz, these are spread across around 2" of board, meaning noise induced into the traces from nearby noisy tracks, and even the inductance of the fine tracks connecting the clock components coming into the equation. With care it's possible to bring these components to within mm of the DAC and then encapsulate them. These are the sorts of things I've been experimenting with.
Tell you something though, jitter is a bugger to measure accurately. Even with the eye-wateringly expensive test kit I have at my disposal!
That TAG kit does look nicely made. I like the addition of the PCB ground plane on the analogue circuitry - though all that digital gubbins must have made for a noisy RF environment inside the box...
"Two very small men cutting steps in the roof of the world"