Why do turntables sound different?


Let's consider higher-end tables that all sound excellent. Same arm/cartridge and the rest of the chain. Turntable is a seemingly simple device but apparently not quite or not at all.
What do members of the 'scientific community' think?
inna
anvil_turntables
Very very good turntables, like other great components have exceptional transparency, which makes them sound more alike than different.
+1. And I would add that the very best turntable systems sound very much like the best digital.
moonglum,

Visited both of your links this morning. Again, I appreciate your solid information. Much food for thought here. Will definitely help and effect my future decision.

Best to You
Norb
Yesterday I saw the Avid contest again.

Three turntables (Diva II, Sequel, Acutus) same tonearm (SME IV)
and cartridge (Nagaoka MP-150).

It was astonishing agein to here such really significant differences in
performance.

Responding to "james1969"

In terms of TT Bearing Oil, no they are not created equal and I would highly recommend the proprietary bearing oil that George Merrill has developed. 
You and other readers may wish to consult the following:
   Turntable Design 1 http://hifigem.com/turntable-design-1.html
   Turntable Design 2 http://hifigem.com/turntable-design-2.html
   Turntable Weights & Clamps http://hifigem.com/record-weights-and-clamps.html
   The Phono System Chain http://hifigem.com/the-phono-system-chain.html
   Torque Recoil http://hifigem.com/torque-recoil.htmlhttp://hifigem.com/

Just interesting reading from a fellow enthusiast and turntable designer.  Hope some insight can be gained and either confirm or refute presumptions, assumptions, and the like.  Happy Listening!
Ralph, would you name those turntables you mentioned that were competent and sounded similar ?
I know, I know, you don't agree aloud that vinyl is inferior to tape medium. Theoretically, maybe not but in reality..
Kuzma Reference, Atma-Sphere 208, Technics SL1200 GAE with Triplanar arm, Technics SP-10MkIII with 12" Triplanar arm. I've heard a much longer list that I don't like and even longer than that are the ones I've simply not heard.

In addition to a solid plinth a robust drive seems to be really important to prevent shimmer in the soundstage. That is why the Lenco, Garrard 301s and some of the early Thorens have a following.

Regarding the tape/LP thing... Direct to Disc is really the only way for vinyl to really show off what it can do. So practically speaking, a tape with good proven provenance is likely to sound better... So in practice on this point I think we are in agreement. I mentioned that provenance thing because it appears that there are a lot of tapes out there that are questionable- its a bit of the Old Wild West on ebay for that stuff right now!