Direct Drive vs. Idler Drive vs. Belt drive

Platter weight 9.8kg = ~21 lbs.  I see no conflict with what you previously wrote, if you're talking about the Bardo.

Mike, Platter of SP10 Mk3 is listed as "10kg" or "21 lbs", everywhere. Not near to 30 lbs. It's heavy enough as is.

Mike, Platter of SP10 Mk3 is listed as "10kg" or "21 lbs", everywhere. Not near to 30 lbs. It’s heavy enough as is

thanks Lew, my 9 year old memory was recalling how heavy the case was with the motor and platter and my guess was wrong.

but.......there is no ’heavy enough’. :-)

my CS Port has a 60 pound platter, the American Sound AS-2000 has a 200 pound platter.

In the past I would have dogmatically agreed that platter mass was a key point for good analog playback. I still think its a key contributor. 

However the Well Tempered Reference has shown me that is not a bit t Truth. I bet its platter does not weigh over 5 pounds, yet it has excellent sound quality, has solid speed stability, excellent bass response, and portrays space in a very believable manner. Is it the best table? No. But for its price point it was a very good table, and viable even in todays marketplace. It may not have a lot of techno wiz bang options, but it still gets to the heart of the music. Mass alone does not define SQ. 

obviously a belt drive tt uses the platter mass differently than a direct drive or idler. which we could write a book about.

but if you investigate the top performers of each drive type they all have relatively heavy platters; and you would find that within each drive type that performance differences would generally relate to platter and plinth mass. it’s not that simple.....but it sorta is.

inertia plays a big role in musical solidity and ease. for tape decks too when you observe solidity of the transports and the deck structure.