Is it best to isolate??

Isolating always leads to depression, or stems from it, for me..

Withe CDPs though I've found nearly anything you put under or on top of it, and what you place it onto does matter as changes will occur.

The 'flavor' of the change IMO comes from more than just those pods, cones, pucks, or balls in direct contact with the player. The rack or resting place plays as much a part too. Some simply buy platforms for players. Simple.

I like the herbie's Audio Labs wooden Ebony balls atop the iso cups so far as the best I've used. Jesus I am cheap come to think of it. $60-$75 for 3.

Like Stan said though, and I've heard from a LOT OF OTHER PEOPLE those roller cups are a viable solution.

Find those folks who allow a trial term and get startted trying 'em out.

Good luck.

You might look into NOS Reflector 6H30-DR in the output stage, my experience is they are much better than Sovtek 6H30p. I haven't used them in an ARC product only my C/J pre where they made a big improvement.
Personally I would go for the tubes first, at least research them, then deal with leading edge grunge with isolation second.
The ARC equipment I've had,CD3 MK11 and VS-115, didn't need much isolation so be careful not to over isolate and lean out the sound.

Aurios MIB's under CD player work very well to improve resolution and bass. I have used them for years under CEC TL-1x transport with excellent results compared to nothing and other isolation/anti-resonance devices.

Neal

Isolate from what? Player vibrations, acoustic energy, foot falls, rack resonance? The most overlooked one is acoustic energy. To prove that just place your finger on the front of the player while playing your typical music, and not. You will be amazed.

some other throughts:

ISOLATION refers to the process of preventing (minimizing) externally generated vibratory energy from reaching a structure or component. Although this includes acoustic or air-borne vibration that is difficult to manage in exposed audio/video equipment, we are primarily concerned with the transfer of mechanical vibration. And, it is essential to understand that there is no significant mechanical isolation provided unless there is relative movement between the component and its supporting structure to prevent sympathetic movement with the supporting structure. Therefore, only a device or material that can compress like a spring or deform like an air-bag or a viscoelastic part, or “roll” like a bearing, can be an isolator. Exceptions to these “passive” examples include “active” systems that have electromechanical “self-leveling” capabilities. Obviously, hard “spikes” and (bare) "platforms" or "shelves" are not vibration isolators.

DAMPING is the dissipation of energy in an vibrating structure or component. It refers to the process of removing (minimizing) internally generated vibration that is inherent in a component AND any external vibration that, for lack of adequate isolation, may enter the component, by converting the mechanical vibratory energy of solids into heat energy - a process called hysteresis. Vibration damping is generally accomplished by the bonding of viscoelastic materials to the (vibrating) internal surfaces, mechanisms and parts of a component and by external coupling to viscoelastic materials or damping devices.