I just went through this same experiment with my VAC preamp. When I purchased the preamp I put the power supply on a piece of vinyl cover MDF left over from an old set of speaker stands that needed to be taller. It sounded great and after almost a year I wondered if it could be improved upon. All platforms tested are approximately 6x9 inches and from 3/4 to 2 inches thick. I tried slabs of granite, John Boos cutting board, solid cherry, and solid oak, with and without Audio Points either between the platform and the floor or between the power supply and the platform. In the end, I preferred my original platform sitting directly on the carpet as before. Each material had a definite sonic signature. The granite had the tightest bass and lower mids at the expense of top end extension and the oak was a satisfying all around but I still found my original platform the best compromise for me, and they all compromise something somewhere and you need to decide what is most important to you.
isolation of seperate preamp power supplies?
Does anyone have the same type of response that I am getting with my Pass X1 power supply? I notice that the sound I get from isolating the seperate power supply has a huge impact on the sound. I have the hybrid version of the X1 so the external power supply is a little black box that doesn't weigh very much but the differences in sound I get by different types of placement and isolation are dramatic. Today I decided to try isolating the supply with an isolation platform on top of 1/3" of marble slab on top of 1 and 1/2" brass cones that go into my carpet. The sound is quite nice.I am also using BDR cones between the power suopply and the isolation platform. I thought this was overkill which is why I didn't try it sooner. Previously I had my power supply on BDR cones#4 on top of a 2" piece of MDF on top of the brass cones and I thought this was more than sufficient but when I decided to experiment with my extra isolation platform(Skylan)I was pleasently surprised. Has anyone noticed that the isolation of pre outboard power supplies makes that much difference?