If you have your CDP on a reasonable rack and platform, my suggestion is adding EquaRack footers. Platforms alone are not adequate in my opinion. I have EquaRack footers under all my equipment. This is the best product I have tried and I have used many different types of isolation devices. These footers not only isolate your CDP but also significantly diminish the vibration in the player (sink vibration from the player into the footers). The whole idea is to decrease vibration in the player for best sound reproduction and this footer does that. Few isolation devices do both well. Web site www.equarack.com provides an excellent explanation of how the footers work. This is probably one if not the most sensitive pieces of equipment to vibration in your system if you are a digital guy. So this is probably where you will get the most bang for your buck in choosing the most effective means of controlling vibration. Lots of products out there so good luck in your quest in selecting the best product for vibration control for your CDP.
