Direct drive vs belt vs rim vs idler arm

Dover, While it's true that both the L07D and the Mk3 have heavy-ish platters compared to most DD turntables (the Mk3 having the heaviest platter I know of among all DDs), the two turntables are otherwise about as dissimilar in design philosophy as any two DDs can be. The Mk3 uses a mutipole cored motor and very tight servo control. The L07D uses a coreless motor and really very "loose" servo correction. The two turntables do sound different from one another.

Can't speak to Syntax's dismissal of the SP10 Mk3 without knowing the condition of the unit that he auditioned and what else was in that system. What Syntax may not have liked about a stock Mk3, even assuming it was working up to spec, is addressed by the Krebs mods to the Mk3 (and to the Mk2). Anyway, if one does not like DD turntables, one may still be a good person. And vice-versa with respect to belt-drive.

Syntax, had you heard depth and physical presence in that system before with a different turntable?

I read that Artisan Fidelity does modify the power supply and electronics in the table and controller. Perhaps not the same mod level as the Krebs, but it is not stock from my understanding.

Altering piano and trumpet tones sounds like speed deviation at a micro level, but isn't the Technics SP10 known for superior speed control, both accuracy and consistency?

Lewm,
Since this thread was started I have had further opportunity to listen to a Garrard 401/Raven/Zyx, Technics SP10mk2/Raven/Zyx ( both before and after full Krebs mod ) and Kenwood L07D all in the same system.

The Garrard 401 presented a more musically coherent sound than either of the other combinations. Specifically the SP10mk2 sounded like it was slewing around, the Kenwood L07D had a bottom end/midrange/top end that was discontiguous.

I have also had a listen to a Technics SP10mk3 with Ikeda arm/cartridge and SME V12/Air tight in the Porter plinth & Krebs mods and it sounded very good. So the only direct drive I have heard that is ok is the SP10mk3.

There is a vast gap in performance between the Krebs SP10mk2 and the mk3.
Having heard the SP10mk2 with and without the Krebs mods, my conclusion is that a Garrard 401 with decent plinth/arm/cartridge will outperform it.

I'm sure there may be better DD's out there - the Koda Beat looks interesting.
As far as I'm aware the Krebs mods are simple mechanical tweaks - there are no alterations to the error correction and servo system operating parameters which are limited by the 70's technology employed.

As an aside the Technics based cutter lathe SP02 motor had significantly more torque than the SP10mk3 motor, and used a 60lb flywheel in conjunction with the higher torque to achieve stability.

My Final Audio VTT1 with high mass platter/thread drive which came standard with a Sine/Cosine Wave generated power supply that requires a power amplifier to drive the motor, has far more solidity, explosiveness, micro dynamics and cohesiveness than any of the DD's I've heard. My second deck, the Platine Verdier, is unfortunately not in the league of the Final, but at least it has 78rpm and I use it as a test mule ( and it did outperform an SME 20/V in the same system ).

Dear Dover, You wrote, "As an aside the Technics based cutter lathe SP02 motor had significantly more torque than the SP10mk3 motor, and used a 60lb flywheel in conjunction with the higher torque to achieve stability."

Yes, the SP02 motor is even larger and has more torque than does the Mk3 motor, so what? The SP02 is designed with a different task in mind, that of driving the cutting of an LP. That said, the Mk3 motor is still the "torque-ist" motor among all the vintage Japanese DD turntables. I however would not use that fact to claim that the Mk3 must therefore be the best of the bunch; the Mk3 motor has to motivate a platter that is the heaviest of the bunch, and I would think that the high torque was deemed to be required to deal with controlling that excessive mass.

Now, as regards your dismissal (or seeming dismissal) of the Krebs mods, it would seem you misunderstand the intent. The Krebs mods are designed in part to stabilize the relationship between the rotor and stator of the motor. When a servo correction occurs that invokes a speed correction, this applies a force that can momentarily disorient the relationship between the two components of the motor (Newton's Third Law of Motion, again). This phenomenon can then induce a "false" signal for servo correction, and so on and on. The net result is frequent servo corrections that emanate from the instability of the rotor/stator interface. Perhaps this is responsible for the coloration that some do hear with the Technics SP10 Mk2 and less so with the Mk3. (I certainly heard it with an unmodified Mk2, much less with an unmodified Mk3 in a 100-lb plinth.) Richard Krebs has devised some methods to stabilize the motor structurally that largely ameliorates the problem and thereby reduces or eliminates it, resulting in much less frequent servo activation. Also, you are not correct in saying that there are no changes made to the power supply/servo module. Bill Thalmann has devised several updates that are part and parcel of a "Krebs mod". And finally, we were not exactly living in caves back in the late 70s and early 80s when these products were devised and marketed. The major improvements in servo technology have more to do with miniaturization than anything else.

Here I feel the need to repeat myself; none of the above is meant to imply that DD turntables, as a class are superior to BD turntables, as a class. I am sure your Final Solution TT is excellent. And I too love idler turntables; I would not ever give up my heavily tweaked Lenco. But I also adore my L07D, so I would like you to amplify on your critique: "Kenwood L07D had a bottom end/midrange/top end that was discontiguous". For example, did the unit you auditioned have a EMI shield between the motor and the underside of the platter?

I find that a fair point about the Sp10 mk3 having a torquier motor due to the heavy platter. It's engineered for purpose so to speak. the ratio of power to weight comes in mind and with it the EMT analogy that a needle/stylus is like driving a car up a hill - if it is small and powerful it can overcome obstacles and undulations quicker and better than say a truck. It is for this reason the EMT 950 platter weighs very little - so I guess it has a very high power to weight ratio. Simply put a single factor of itself needn't and often is not the only factor in an equation.