This is the way of the turntable world: manufacturers have made their choices between hi and lo mass and hi and lo torque, and between direct-drive and belt-drive (and idler-drive). Then comes the technical justification for what each has done. Techdas, as you know, is by far not the first manufacturer to choose hi-mass platter combined with lo-torque motor. I think the first guys to go all the way with that were Lloyd Walker and David Fletcher (Nottingham Analog). The consortium in the American West that gave rise to Teres, Galibier, and Redpoint can also take some credit. It is merely up to us to listen and choose. Chronologically, I don't know where Final Audio fits; perhaps they were leaders too in implementing that idea. (Is "Techdas" coming from Dertonearm, by the way? I had not heard of this new brand, but I do know DT announced plans to bring a turntable to market, and he does preach very high mass/low torque.)
"The torque ripple or cogging torque will be lower"... I think a better way to put it is that the cogging of a motor spinning at 1800 rpm will occur at a higher frequency, for a given number of poles, and perhaps (really, perhaps) is less likely to be audible for that reason. But on the other hand, such a more rapidly spinning motor will be more likely to emit vibrations and noise, due to structural imperfections. Enter the belt-drive. Further, Kenwood, Pioneer Exclusive, Dual, and a few others back in the day used coreless motors to minimize if not eliminate totally the issue of cogging in their direct-drive turntables. Another wag on these pages or on VA has opined that cogging is essentially inaudible. I have no opinion on that.
Do you happen to know what is the rotational inertia of the L07D with the optional peripheral ring weight installed? I am using it with mine. Interestingly, when one uses the ring, one is also told to flip a switch on the outboard PS which I guess changes the servo so as to recognize the additional mass.
If you prefer your thread drive to any and all direct-drives you have ever heard, that is all well and good. I am sure it is superb. But I don't think you can prove from first principles that it is inherently superior to all direct drive.
"The torque ripple or cogging torque will be lower"... I think a better way to put it is that the cogging of a motor spinning at 1800 rpm will occur at a higher frequency, for a given number of poles, and perhaps (really, perhaps) is less likely to be audible for that reason. But on the other hand, such a more rapidly spinning motor will be more likely to emit vibrations and noise, due to structural imperfections. Enter the belt-drive. Further, Kenwood, Pioneer Exclusive, Dual, and a few others back in the day used coreless motors to minimize if not eliminate totally the issue of cogging in their direct-drive turntables. Another wag on these pages or on VA has opined that cogging is essentially inaudible. I have no opinion on that.
Do you happen to know what is the rotational inertia of the L07D with the optional peripheral ring weight installed? I am using it with mine. Interestingly, when one uses the ring, one is also told to flip a switch on the outboard PS which I guess changes the servo so as to recognize the additional mass.
If you prefer your thread drive to any and all direct-drives you have ever heard, that is all well and good. I am sure it is superb. But I don't think you can prove from first principles that it is inherently superior to all direct drive.