@hilde45, yes good old squash balls which I have tried long ago and work surprisingly well. I found that depending on the load they carry the performance varies. If you're lucky and the combination ends up with a low enough resonant frequency then all well but if the component is too light then weight needs to be added which is a bit hit and miss. I recently placed some unlikely looking and inexpensive Vibrapods model 1 under my 'The Truth' line stage and am now enjoying a much cleaner sound particularly the removal of some annoying sibilance. They come in 3 different weight ranges.
I was hoping to save lots of juggling of shelves by someone's experience claiming that digital components would provide the most benefit for example. Well will just have to try the platform under different components. My feeling is CD or DAC may provide more improvement than amp because of the sensitivity to vibration of the clocks. When time permits I will find springs that will resonate at about 3 to 4Hz like Townshend's do for my speakers. Not difficult to DIY. No spikes for me🙄