I've tried BDR cones, Stillpoints and Feet of Silence under my DAC. The Feet of Silence made the most positive difference. The contrast with Stillpoints was instructive - using the Stillpoints the music lost its bloom, and sounded overdamped and constrained. The Feet of Silence let the music breathe mone freely. Frankly, the BDR cones made very little difference to the sound.
This is under an Audio Note DAC 4.1x Balanced, so I presume that the suspension provided by the Feet helped isolate the output tubes.
This is under an Audio Note DAC 4.1x Balanced, so I presume that the suspension provided by the Feet helped isolate the output tubes.