Nothing wrong with starting with the amp. I would find out where the power transformer is and put one foot under that or under them both if your amp has two transformers as they create the most vibration. Joe (the designer) recommends four of the feet under each component instead of three, that’s why he includes different thickness metal shims which allows the user to shim the fourth foot so there is no rocking motion and the component is rock stable on the shelf. They’re designed to go flat under the chassis, not under the components factory foot. The are vey expensive but after hearing the improvement, I found it impossible to live without them. Enjoy!