Try innertube under and sand on top. Cheap solutions can work. Damping pads inside the top cover might help. Dont let anyone make you think you have to spend big bucks unless you want to.
Sand bags under a cdp - didn't work well
Last night I started the process of vibration control with the use of sand bags (3) under my Arcam cdp. What I found was that while everything became more focused/detailed it also became more sharp/harsh/forward/aggressive. I didn't know what to expect but it certaintly wasn't this. Van Morrison's voice on trk #5 on Sailing to Philadelphia was abnormally aggressive and in the end I preferred the sound without the bags. Any thoughts as to why things became too sharp & aggressive????