VPI SSM lacking bite

Sns, the explanation is simple. There are HF vibrations that move bidirectionally between TT and earth. A properly designed compliant suspension can be particularly effective in transforming HF vibration into benign LF mechanical energy. The complication is that compliance in the suspension must not allow fluctuations in horizontal geometry of the drive train-- easier said than done with a TT that like VPI has a detached motor.

Dave, is LF mechanical energy truly benign, slower oscillations should impact sonics as well, I prefer to drain off all energy maximally. The fluctuations between motor and tt are just another complication. I suspect it might be best to spike motor as well, haven't tried yet.

My take is that VPIs should be best situated with large mass spikes coupled to massive vibration sinks maximally decoupled from external vibrations, ie. wall mounted or cement slab decoupled from rest of flooring.

I will soon be building a huge sandbox (planning on over 300 lbs sand), changing out stock spikes for Star Sound large mass brass spikes, figure out some means to spike motor, all mounted on my de-coupled wall shelf. This should test my theories, based on previous exploration in this direction I expect much better performance.

Sns, conservation of energy principle says you can't get rid of energy, but rather can only change its form. Someone posted that if sand was enough, why can we still feel the pounding of surf through the beach? Throw a soft spring mattress down on the beach, and you will no longer feel the ocean.

Dave, I agree that a soft spring mattress on the beach decouples you from the surf, but this is more analogous to using something compliant underneath the the sandbox. Essentially you are de-coupling from external energy (the surf). Any vibrations within your body (assuming bodies vibrate :-) are still being reintroduced into your body from the compliant mattress.

My experience with TT is closer to your analogy of beach on mattress. I have an unsuspended VPI TNT on top of a heavy sandbox on top of large soft springs. It was the only way that I could definitively stop a knuckle rap to the rack below from traveling to the stylus. With this addition there was an obvious improvement in treble focus and smoothness. Now what is happening? Based on my arrangement of system, room, and rack, my speculation is that the springs absorb energy from inside TT as much as they isolate from earth-- perhaps even more so. Others have confirmed this speculation by testing the same system on a wall rack to further remove from earth and floor effects. The effect of long wavelength spring action is benign: I can force the soft springs into a gentle cycle of diminishing modulations without disturbing the arm or audibly effecting the stylus in motion. This forced low frequency long wavelength action is absorbing huge amounts of physical energy relative to what is generated from within the closed system of a TT and its motor. Why then should it not work just as well and remain stable when handling the much tinier vibrations generated by TT?

All sprung suspensions are not equal. Foot-steps across the room sets my lightly sprung Oracle TT on fire. But the massed-loaded combination of a 50lb unsprung VPI on a 100 lb. sandbox on top of springs behaves entirely differently.

A bigger sandbox is certainly better than a smaller one. But to complete the experiment, why not try even more decoupling?