I use or have used Symposium shelves, couplers and rollerballs under CD players. The shelf provides both isolation from external vibration and dampening of self generated vibration. The shelf dissipates any energy transmitted to the shelf in its soft foam core. The couplers are made of aluminum and are brick shaped. They are designed to couple the bottom of the equipment to their shelves. The rollerblocs work on a different principle. With roller blocks vibrational energy is dissipated by the work required to roll the piece of gear uphill against gravity. These are very effective at reducing self generated vibration, such as from the mechanical moving parts in a cd player or from the power transformer vibrating.
I have heard the couplers, shelves, and rollerblocs under several different players. These are essentially tuning devices, so the result will be a change in sound, though not necessarily a favorable change. For example, in my system, the rollerblocs improved clarity a bit under a Sony SCD-1 player. Either the rollerblocs or the couplers under a friend's Aero Capitole player made his system sound too dry and analytical (a surprisingly big change). Either the rollerblocs or couplers under my current player, a Naim CD555, seem to make very little difference (the player sits on Symposium shelf).
Because they reduce what is supposedly unwanted vibrational energy, one might be inclined to think that isolation/dampening must be beneficial. I don't think that is necessarily the case. They can change the sound signficantly, but only a trial can determine if that change is positive or not.
I have heard the couplers, shelves, and rollerblocs under several different players. These are essentially tuning devices, so the result will be a change in sound, though not necessarily a favorable change. For example, in my system, the rollerblocs improved clarity a bit under a Sony SCD-1 player. Either the rollerblocs or the couplers under a friend's Aero Capitole player made his system sound too dry and analytical (a surprisingly big change). Either the rollerblocs or couplers under my current player, a Naim CD555, seem to make very little difference (the player sits on Symposium shelf).
Because they reduce what is supposedly unwanted vibrational energy, one might be inclined to think that isolation/dampening must be beneficial. I don't think that is necessarily the case. They can change the sound signficantly, but only a trial can determine if that change is positive or not.