Those are my ancient VPI Bricks that I repainted to match the SRA bases. They're iron bricks inside a thin wood skin. They're great mass loading dampers on anything as each weighs 5 or 6 pounds or so. They slightly improve the sense of focus and bass articulation. But frankly, the SRA bases do far more for the sonics. Those are made by a company that started out doing government contracts for isolation of vibration and sound attenuation on nuclear submarines. The rack is made by SRA too. THey call it a CRAZ rack, though I'm not sure why. The top dark shelves on the rack weigh well over 100 pounds each and are are isolated by bladders filled with a gel-like damping material mounted to the cherry rack frame. If you nudge one of the rack shelves it oscillates for a few seconds at around 5 or 7 hertz, just like a giant suspended belt drive turntable. The rack and bases are phenomenal at isolation. The character of the systems sound doesn't change from a whisper to full volume. Even fully cranked, subtle detail comes through without any smearing due to feedback or vibration.
Originally Posted by aRRR
Sanderman, Im curious; how do those blocks on top of the transformers affect the performance?