The problems associated with direct-drive were well known to the guys who designed the very best direct-drive turntables of the 1970s and 1980s, which was not exactly the Dark Ages in terms of electronics and engineering. The very best direct-drive tables of those days dealt with the issues in very effective ways. In many cases, their work fell down, if it fell down at all, at the level of plinth design and implementation. Poorly designed plinths account more than anything else for the colorations that one perceives in the mid-level Denon turntables, for one example. With a little ingenuity, one can build much better plinths for these products which mitigates their sonic character. Another source of sonic coloration may be that the built-in motors radiate EMI that can possibly pollute the signal at the cartridge. We now have very effective shielding materials that can eliminate such problems. The DIY effort is well rewarded. The same is true for the best idler drive turntables, despite their dismissal by "Elizabeth". If you want great sound for less money than any comparable belt-drive table, I would encourage you to experiment with top quality direct- or idler-drive turntables of the good old days. |
Dertonearm, Have you seen the photos of the new "direct idler-drive" turntables to be marketed by TT Weights? There are two models, one megabuck and one for under $10K. But both sport VERY heavy platters in the 30-lb range and higher. I thought that would make you happy. (Unless your minimum criterion for Nirvana was >30kg, not >30lb.) Still, those are fascinating products. |
Dertonearm knows I do not necessarily concur with his gross generalization regarding platter mass, as it may apply to anything other than a belt drive turntable. But we have beaten the subject to death on another thread. However he is quite right; it would be folly to add a high mass platter to any direct-drive system that was designed for a relatively low mass platter, based on my reading of posts by other more knowledgeable persons (specifically "Steerpike" and Mark Kelly, over on DIYAudio, who were discussing the design of a modern controller for an SP10 MK2 or Mk3).
The Kenwood L07D is interesting in this regard. It has a "relatively" high mass platter, much of which mass is concentrated at the periphery of the platter, and the servo system is designed to cut in and out once the platter is up to speed, so in part it depends upon platter inertia to maintain stable speed, like a weak belt drive with a massive platter. In addition, the magnet assembly that forms part of the motor is actually affixed to the underside of the platter, as in the SP10 Mk3. Thus the platter is in effect part of the motor and in theory the only "noise" injected into the playback could be that from the bearing itself, much like any belt-drive. I hope to have my L07D up and running by the end of January. |
We have been here before. It is hard to say exactly why the best DD and the best idler-drive turntables seem to have more drive/pace/rhythm, because any differences in "speed accuracy" among all good turntables, including good belt-drive tables, are miniscule at most. One can invoke the factor of "stylus drag" and the ability of DD and idler-drives to maintain absolute stability in the face of this force. Yet one has to be skeptical that stylus drag could be of such magnitude as to play into this equation, especially as regards the massive platters of some BD tables that would seem to be able to overcome stylus drag by virtue of inertia. In any case, the measurements of speed accuracy that we read about are likely to have been derived by averaging the speed over a relatively long-ish time interval (even seconds constitute a long time in terms of musical transients). What I think we are hearing in DD and idler-drive tables that may distinguish them is speed stability over micro- or millisecond time intervals. Yet intuitively one wonders whether the servo mechanisms of dd tables can operate effectively in such a small time window. So, I don't know what's going on, but I like it. |
Actually, I was quite struck by the similarity between what someone else just up the thread a bit wrote about the M20FL Super, as compared to my own impressions. That other guy was likely using completely different ancillary equipment, yet his words could be substituted for my own in describing that cartridge. (It might have been Axel, who uses all solid state gear, whereas my electronics are all tubes except for my MM-dedicated phono stage.) I think this is because each of us becomes acutely sensitive to the "sound" of our own complete systems. As a result, there is remarkable consensus (by and large) on the "sound" of the transducers at either end of the chain. Our uncontrolled perceptions may not align so well if the item being evaluated is not converting mechanical energy to electrical or vice-versa. (I use the term "control" in the scientific sense, which is what Raul is really talking about.) |
Oops! The above post was meant for the thread on MM cartridges. Sorry. But the point is relevant to this discussion too. However I do apologize for bringing the mention of mm cartridges into this thread. |
Cjaronica, This is not to dispute your logic in ending up with a TTW turntable, but a turntable per se is not going to exaggerate "record surface noise". That phenomenon is typically due to the phono stage, the cartridge/tonearm combination, cartridge set-up, or a combination of all these elements. |
The experiment has been done by anyone who converted his Teres or VPI turntable from belt- to rim-drive using the motors now available from the respective manufacturers. In these instances, all other factors are held constant; only the drive system is changed. As far as I know, almost all end-users have preferred rim drive vs belt drive. One could be skeptical of those claims, because there is a lot of subconscious bias in favor of hearing an improvement, in my opinion, when one spends money for such "upgrades". (The very use of that term suggests a bias.) But I am inclined to believe that the benefits are real, based on my own completely uncontrolled experiments comparing a "good" belt drive table to various idler-and direct-drive ones. (I am a scientist by profession, so this stuff bothers me.) |
