Rhythm is the heart of music. It is more important than melody, harmony, tone color etc. Ask any musician, and he/she will tell you that the most beautiful tone, sounding the most beautiful melody, but with bad rhythm is meaningless. There is a truism among musicians that "no-one ever got fired for having a bad sound". An exaggeration perhaps, but the point is that without a great sense of rhythm, resulting in beautiful, controlled expressiveness, everything else becomes irrelevant. That sense of rhythm/expressiveness is also the most fragile element of music. The slightest deviation/distortion, and the "feeling" of the music is destroyed; to a much greater degree than by deviations from an "ideal tone", whatever that might be.
I often feel that we audiophiles are not respectful enough of the fragility of music. The recording/playback process, even under the best conditions, can only destroy some of the expressiveness. What is left, to be retrieved by the stylus tracing the grooves is even more fragile, by virtue of the fact that there is less of it there, as compared to the original performance. This is the reason for being intimately familiar with the sound of live music. We simply won't know what we are missing otherwise.
What does all this have to do with the subject of this thread? To me, everything. After years of trying to make my belt-drive tables (currently a VPI TNT6) sound right, and having owned some of the less exotic direct-drive tables, I am coming to the conclusion that direct-drive is the way to go. I have not heard every heavy-hitter in either camp, but have heard enough of them to feel comfortable with this conclusion, for myself. My TNT is adequate in the speed stability department, but only adequate; most of the time. Tonally, I think it is great. The DD tables I have lived with (not the heavy hitters), have had great speed stability, but not the expressiveness. I think this is due to their inferior tonal characteristics. This is the tricky part of all this. The sense of rhythm/expressivenes of a turntable, regardless of it's drive technology, is affected by it's tonal qualities; which are the result of the resonance properties of the materials employed. But, as with musicians, if you don't start out with rock-solid speed stability, nothing else matters. For this I am now convinced, you need direct drive, and high(ish) torque. The only tables I have heard that struck what I consider a really great balance of rhythm/expressiveness and tone were of the DD/heavy plinth types. These were a replinthed SP-10 MK2, and a lowly replinthed Luxman DD, that as much as I hate to admit, made more music than my TNT.
So how do we explain the sense of rhythm/PRAT of the Linn-type tables. I believe that with those designs, the balance of rhythm/expressiveness and tone has been tilted in favor of a tonal balance that psychoacoustically "lifts" the sense of expresiveness, without actually being as rock-solid (accurate) as the direct drives. Kind of like those "low-fat" potato chips that have twice as much salt as the regular ones, in an effort to make them as satisfying.
Just some thoughts; fire away.
