@luxmancl38, although I’m a great believer in isolation I wouldn’t try too hard in your case. The PD 171 is already one hell of a record deck.
Your existing stand/concrete floor will filter most of the higher level seismic garbage (a la Technics SP10 stands of yore). The decks own isolation system will do most of the rest. To go further you might need more than sorbothane ie high compliance springs. But then you risk lateral stability issues.
Taken from their website
http://www.luxman.com/product/detail.php?id=25
Under-slung system
Your existing stand/concrete floor will filter most of the higher level seismic garbage (a la Technics SP10 stands of yore). The decks own isolation system will do most of the rest. To go further you might need more than sorbothane ie high compliance springs. But then you risk lateral stability issues.
Taken from their website
http://www.luxman.com/product/detail.php?id=25
Under-slung system
All major parts are attached to a 15mm thick aluminum plate which connects to the main chassis by our original under-slung (hanging) method, successfully achieving both high rigidity and vibration damping.
The motor and the power supply transformer, which can cause vibration, are attached using floating mounts to achieve a higher signal to noise ratio.
Four large caliber spring-and-rubber insulator feet directly connected to the chassis prevent feedback and external vibration transmission.
In addition, the hybrid vibration damping structure of the metal chassis and wooden exterior contributes to a high level of sound quality.