I use the Aurio 1.2 under my deHavilland Mercury preamp with a 1/4 " piece of maple between preamp and Aurio which took all the ringing out and is superb. I use the Sistrum under my amp which is fabulous and would probably be great under a preamp.
Tube Preamp Isolation
Currently using Vibrapod cone/isolater combo under my Music Reference RM5 MKIII. I've got it on a Billy Bags rack. I've got an Audio Research LS15 on the way and am wondering what you guys use (if anything) under your tube preamp?