Direct drive vs belt vs rim vs idler arm

The myth of Direct Drives and Lathes

Direct Drive devotees often refer to cutting lathes and make claims about the suitability of DD's for replay based on their use in record cutting lathes.
I would like to point out the following :
The Technics SP02 is considered one of the best DD lathe motors. Yes it is Direct Drive, but in most cutting lathes the platter is 70lbs or so ( Neumann for example ) and designed to act as a flywheel - more weight on the outer. So in other words cutting lathes are usually using very high inertia platters to provide stability in conjunction with whatever drive system is chosen.
Most of the best classical music in my view was recorded before the mid sixties, when multi miking became popular and the engineers took over the asylum. Most music was recorded on shaft driven or belt driven ( some Scully lathes for example ) lathes with very high inertia flywheel/platters.
This to me this is a compelling argument for using high inertia, irrespective of the drive methodology chosen.

I should have made it a bit clearer in the last post, most Technics SP02 cutting lathe motors I have seen are coupled to high mass flywheel/platters in the order of 70lbs/30kg.

I have a pragmatic question. I did some maintenance on my tt last weekend. I checked screw torques and surprisingly, all of the armboard screws turned about a quarter turn. I got it all back together and dialed in speed perfect. All is looking good. I put on Fresh Aire III again. Nice bass, a little tighter than before, I think. So I put on the CD version and give a listen to track 1. On the CD I can hear the skin on the drums; on the record- almost, but just not quite there. My question is: is that the smearing of detail you all are talking about? Is that really due to speed control, or could it be tonearm, preamp, etc?

Dear Dover, There you go again. Trying to "prove" that one drive system is "better" than another (or in this case, "worse") by arguing from first principles. First, I think there are a lot of holes in your arguments, and second, have we, or at least most of us, not agreed that execution is paramount? That each drive system has its failings?

By now I get it; you don't like direct-drive. You do like your Final Audio TT. Live and let live.

On terminology: Motor "slip" is a term I have only read in connection with induction motors. They must slip in order to generate torque. This would apply only to idlers, as the older idlers are the only TT's I know of that used induction type motors. Induction motor combined with eddy current or other type of "braking" can make for excellent speed stability. Also, "jitter" has a specific meaning in terms of digital to analog conversion. Let's not confuse matters further by using it to describe a phenomenon related to what? Cogging or servo correction? These two phenomena are entirely separate and independent of one another, and yet they are being lumped.

FWIW, The top end Denon DD's used 3-phase AC synchronous motors. The top end Technics DD's use what you would call DC motors. But Bill Thalmann told me in conversation that if you look at the actual circuit of the Technics, the distinction between the two is not so great. DC motors are used in some of the most expensive BD turntables, as well, and the manufacturer's tout the fact.

Hi Richard

02-02-13: Richardkrebs
Ct0517
Re the Bear that tries too hard.
He doesn't have to been so stressed.
I can help him relax.

Big smile when I read that. Thanks.
In the “bear room” when they are happy; I am happy.
They are picky about the type of honey they like. :^)

SP10MKII - Not being an electronics engineer I always attributed the phenomena to cogging, or the servo having to keep speed (always a little high or low) in order to stay at speed ? Your posts have shed new light on this. Dovers last posts :^) again raise a number of points. What is it about audiophiles from New Zealand? A competitive bunch.

To improve the SP10MKII based solely on what I hear I always thought;
A little less speed correction if possible - but enough to just keep it stable?

As an owner of one I will be interested to hear/read about any direct comparisons between SP10MKII’s and MKIII’s, which have your mod. Does the gap get closed? The SP10 is still my PET project, self pride is involved and I continue to learn from her.
Cheers Chris