Turntable Platforms - Low mass? High mass? Why?

Goatwuss, what's important is "rock solid". Some interpret that to mean "high mass" but it's not necessarily true as long as it's solid and doesn't ring, which usually means a shelf with a "constrained layer" of damping. What's that you ask? It just means two layers of solid (not necessarily the same) material, with a sheet (or layer) of damping material (sorbothane, foam, gunk, peanut butter) in between.

From another thread, here's my little prepared speech on vibration control, including TT's:

If you want only to "drain off" internal vibrations created within a piece of equipment, then you need a "mechanical diode" like cones, rollerballs or graphite bags. (A "mechanical diode" BTW is something that lets the vibration travel in one direction but not back the other way.) Assuming a steady, rock solid surface on which the equipment sits, this works pretty well for both transports and electronics (i.e. amps that sometimes have transformer or tube vibration.)

If you want to protect a piece of equipment from external, non-airborne vibrations that are transferred to the equipment from whatever it's sitting on, then you need a vibration damper or shock absorber like Stillpoints, Sorbothane pucks, or springs. These can make the equipment somewhat more susceptible to airborne sound energy (-- not generally a problem I've found, unless it's sitting right in front of a loud speaker.)

So, except for turntables, which in my opinion always need both type of treatment (diode at the shelf, and squishy between the diode and the plinth) most situations only require the diode (again, assuming a rock solid non-vibrating surface on which the equipment sits.)

If you feel your situation requires both types, you could try at least 9 combinations of devices picking one from each category, and then multiply by 2 to allow for the squishy-over/under-diode variations and that gives you 18 ways to Sunday. My personal preference, if anyone gives a rat's a**, is cones under sorbothane, with Stillpoints replacing both for heavier equipment (rated at 200# capacity each I believe.)

Thanks Nsgarch, that approach does make sense.

Currently I have a Rega P25 sitting on a spiked Ikea Lack table - no mechanical diode as nsgarch calls out. I have been told that this is a good setup for this table. Would a Michell Gyrodeck work just as well on this end table? A Teres? Basis?

I guess I forgot to include spikes in the "mechanical diode" category. The Rega already has a "squishy" suspension right? So you're done!

The Rega philosophy is a light and rigid shelf or platform.Following this I had square piece of acrylic cut to size.Under the turntable you could have vibrapods under each foot.With a Rega P25 you have a 5 vibrapod at the back,a 2 at the next heaviest spot on the left and finally a normal vibrapod on the right where there is not too much weight.This sits on top of the acrylic shelf about 3/4 inch thick cut to size.You put some form of metal spiked feet under the shelf the same as those for speakers is o.k.The vibrapods were worked out after long testing and I can vouch it is effective on a Rega P2 although the original idea was worked out with a P25 and mentioned in the vinyl asylum and Stereophile.

That sounds like the way to go. How does it perform?

It cleans up the low-end quite noticeably and enhances detail.The vibrapods help the Rega feet drain away vibration as they are supposed to and the rigidity and decoupling effect of the shelf aids this also.

Bright Star Audio believes you should have a high mass (Big Rock 19) isolated with air Air Mass 19. Lots of mass isolated from enternal vibation. Problem is this stuff ain't cheap.

Dear Todd: Take a look at: www.vsengr.com/triorbs.html

These Van Slyke isolators do magic under your TT. I use it after try anything else. It really works.

Regards and enjoy the music.
Raul.