Isolation feet/cones for PS Audio NuWave DSD DAC

The rubber caster cups ghosthouse suggested are too soft, but a cheap alternative is available---chrome nickel plated, bowl shaped, drawer pulls. Screw each onto a little block of mdf or plywood, or a trio onto a small sheet of same.

@bdp24 - Curious what you mean by "too soft"...
Too soft as in won’t adequately act as a conduit for vibration? or too soft w/respect to deformation under the load of a component??

If the latter, not sure that is the case. Each cup can support up to 500# (so the product literature says) and the cups are some sort of rigid, hard plastic, not soft rubber. I have on in hand.  Only the bottom O-ring providing "grip" is rubber.

I do like your concave drawer pull idea. Another possibility is an "acrylic dimple block" used for displaying baseballs, mineral spheres, decorative eggs, etc. The "dimple" is a concave depression that can accommodate a bearing. They come in various sizes.

The reason both the metal balls and the curved based should be as hard as possible is because friction should be reduced to as close to zero as possible. This is why you see tungsten and cryo'd steel used for the balls and cups. I suspect NASA grade ceramics would work well, too. Remember, isolation can be defined as the ability to move freely in the direction of choice. In the case of roller bearings that means freedom of motion in the horizontal plane and twist (rotational) direction and to the event the ball can travel up long the curved surface of the cup in the other two rotational directions. The roller bearings don’t provide much of anything for the vertical direction, hence their use with springs. But five directions out of six is not chopped liver.

Ah. Thanks Mr. Kait. Okay. No doubt those plastic floor guards won’t be as smooth as the Ingress Audio pieces bdp pointed out. For the price though, worth a try. Certainly at least on par with Diament’s wooden egg cup suggestion; maybe better with the application of a little silicone to the surface. That should help get things rolling.

Apologies to the OP for contributing to the detour the discussion has taken.  Hopefully some of this extraneous discussion will be of interest.  

@ghosthouse  all is good. In general I am really interested in DIY and the topics discussed.
In this specific case, given the responses to the effectiveness of the DH cones and their current price, I don't think its worth the effort.
For pure experimentation though, maybe.