I have no specific experience with those brands of isolation feet, but, in general, don't find that hard feet do much unless they're used to couple to a good isolation platform. If you're placing the CDP on an open shelf or something that transmits vibration, you might even degrade performance. If you can't afford a good base at this time, I'd recommend going with a set of absorbative feet.

It's surprising how isolating a CDP can improve its sonic performance. It's not in the same league with isolating a TT, but it tends to provide a noticeable step up in resolution of lower leverl detail and stronger bass performance.

Dave

Unless the support shelf is itself isolated to some degree, cones and spikes and rollerballs are less than totally effective. If you feel your rack or support system is in odrder, then the rollerballs should offer a nice improvement. The question would be the cost vs benefit ratio. Just my opinion but I would try either a sandbox or something on the order of the Gingko products.

http://www.enjoythemusic.com/Magazine/equipment/0800/brightstar.htm
http://www.6moons.com/audioreviews/gingko/cloud10.html.

Both of these in combination might be in order and both can be experimented with on a diy basis.

http://www.cognitivevent.com/sandbox.html

As was mentioned in another current thread, an inner tube is an effective way to isolate your equipment from the external forces working on it.

http://forum.stereophile.com/forum/showf...part=1&vc=1

You can do a sandbox, but you will find greater effectiveness in using a set-up that drains resonant energy quickly and efficiently rather than provide isolation. Plus a sandbox is messy and potentially hazardous with anything with moving parts.

IMHO, you don't need to build a sandox. Simply put your CD Player on a partially inflated 12" Kenda biycle inner tube. Put one under your amp for that matter. Each inner tube will cost you about $3. Way cheaper than rollerblocks.

You will be very pleasantly surprised at the improvement, and, more importantly, the quality of the improvement it makes.

There is a common mistake that alot of people make and I'm not certain whether you are falling into the same wrong assumption or not. When the concept of something more sophisticated than tennis balls and inner tubes became popular in audio, the thinking for many components was a massive shelf unit that would drain away vibration entering from the room itself by the sheer mass of a shelfing unit. This works fine for certain components but not for everything. For example many turntables will sound much worse on a massive shelving unit than on a simple light open framework support.

Energy cannot be made to disappear so it must be dealt with in some manner. What happens in a massive structure is the energy is damped to only a small degree as what is damped is converted to heat. However, due to the mass itself, what is left over - which can be significant when dealing with a homemade structure - is held on to for an amount of time as it passes through the structure. When it is finally allowed to exit at the component end it is out of phase - out of sync - with the signal in the unit at that exact moment. Most especially in source units and particularly turntables where you are dealing with a mechanical system in contact with the disc this out of phase information that has been released by the support structure enters the player and causes time related distortions to appear which tend to smear fine detail, working to destroy imaging and the momentum of the performance.

This is why many manaufacturers suggest their equipment be placed on a light but rigid support system that allows the acoustic/mechanical feedback to release from the support quickly and hopefully closer to in sync with what is happening in the equipment at that moment.

Regarding whether to isolate or to couple, that is going to vary from component to component. Isolating a component from the mechanical feedback of the system and room does little if the component is still being affected by the mechanical vibration from within itself, vibration typically generated by a power transformer. Coupling the transformer to minimize the amount of vibration and hopefully drain what is lfet over into a solid support system will then very likely to be your best solution. This brings you to the point where in some cases you are trying to both isolate and couple the same component. Not an easy task but one that is often addressed by more sophisticated devices.

Spot on, Jan. Your comments mirror almost exactly a post by a member on AK that I read just yesterday.