Direct Drive turntables


I have been using belt drive tt's. I see some tt's around using direct drive and they are by far not as common as belt drive ones. Can someone enlighten me what are the pros and cons of direct drive vs belt drive on the sound? and why there are so few of direct drive tt's out there?
Thanks
128x128alectiong
I did not propose that the goal of measurements is accuracy. (Although in the determination of platter stability pertinent to belt drive versus direct drive, accuracy of constant rotational speed probably is the goal). For somebody who likes colorations, measurable inaccuracy may be the goal.

For example, Raul cites an audiophile who likes colorations. Raul appears to dislike artificial colorations. It is not my duty or right to tell somebody what they should like. It is conceivable that measurements, graphs and other repeatable and predictive forms of communication could help each of these two audiophiles get what they want.

So, I believe that if a consumer wants pitch stability that is suitable to his personal demands, reliable measurements that describe the differences between the platter rotation of belt drive versus direct drive would help the consumer (and not help turntable manufacturers who don't want to learn and improve).
Dear Teres: I agree on that 70's electronics example.

I want to argue not what happen in the 70's with electronic designs but what we have today. It is clear even today that there are audio items that could measures good but sounds awful because different factors: bad design, bad parts selection, bad execution design, wrong layout, bad quality circuit board material, use of negative feedback in the wrong place or exesive one, use of op-amps or IC chips that for lower distortions use hundreds of negative feedback, etc, etc; but with a decent design and good execution design with the right parts selection and the like something that measures good normally sounds good too.

The understand of mesures and its correlation with what we are hearing is difficult because ( example ) we can have an audio item with very low distortion figures and could sound bad because the distortion measures alone don't tell me the full " history ", we need to know which kind of distortions are generated on that audio item: even/odd harmonics and at what output level, many items has problems because inadequate phase frequency response and many other " ocult " factors that the manufacturer normally not disclose and only through specific measures we can know the why's/where what we are hearing.

Sure that could be that an amplifier with low output impedance ( say: 0.05 ohms. ) can/could sound bad and many examples like this tell us that our first step is that we have to understand what each single measure means, second step we have toknow what to measure, where to measure and how to measure and third ( not last step, there are more. ) how some of those measures are related to give us an answer of what we are hearing. I know is not an easy task but IMHO we all need to start an overall understanding about, this understanding IMHO could help to each one of us to improve the quality performance of what we have at home.

Teres, I'm for accurate good emotional sound: nothing less. If our ears are true trained on music we can discern between a good sound ( colored one ) and a good accurate sound, which one do you prefer?, certainly an accurate one if you are trained to discern it. Problem is that this is more easy to say that to achieve because to have this very high grade of discern require wide experience not only on music but on understanding of the different audio link performance in an audio chain, this means a wide experiences hearing a lot of different audio systems in different environments, in a few words: be an expert! with all what this word means.

Regards and enjoy the music,
Raul.
Raul your comments above 1-8-10 ending with Shame of us and Shame of industry we have ( with exceptions )

The burden of blame for promoted WAY over priced mediocre junk rests with the typical consumer involved in this hobby.

Of course slick marketing and promotion through the audio media helped steer this hobby where it is today.... They know the typical customer and know them well.

Just being a designer of any said component or reviewer certainly means nothing if you can't hear in the first place. However with the right distributor and other industry types your product will sell even at an highly inflated price....

Most certainly! there are exceptions to this.
I have two 30+ years old turntables, which are Luxman PD-444 using direct drive. These have co-existed over the years with Linn LP12, Pink Triangle, multiple VPIs, Mission, Rega, Systemdeck, Thorens, Lenco, Transcriptors, Michell, Sota, Kenwood, Pioneer and other turntables and have survived every challenge. There was a Luxman PD-441 little brother in the mix too -- excellent but not quite as lovely as the larger, heavier PD-444 that accommodates two tonearms.

Listen to a Luxman PD-4XX turntable and you will not doubt the ability of well-enegineered direct drive to deliver music with energy, flow and tone, against quiet backgrounds and audible speed stability.

These specific Luxmans also represented sound thinking with persistent validity. I recently disassembled and reassembled one of my PD-444s and was struck by how much it shares with the current rave, the belt drive VPI Classic. The VPI Classic has a solid plinth of MDF bonded to steel and compressed with through-bolts. The Luxman has a core of lower-density chipboard sandwiched tightly sandwiched between heavy iron plates with an aluminum overlay on top, and the whole sandwich is compressed via through-bolts. The VPI Classic has its belt-drive motor mounted directly to the plinth, which also holds the main bearing and tonearm. The Luxman's direct-drive motor is also mounted directly to the plinth incorporating its (mag-lev load reduced) main bearing and tonearm mount. The VPI has an actual weight around 55 lbs. The Luxman 444 weighs about the same.

But one difference aside from dd vs. belt drive is that the Luxman stands on very good (but dated) tuned-resiliance feet with spring, rubber and silicone elastic/damping elements. The VPI is mounted on solid feet of Delrin and metal. So I recently updated my Luxmans to solid footing. Living now in a slab-foundation house with wood-over-ply-over concrete floors, I have no concern with footfalls. So I removed the sprung feet from the Luxman and replaced them with heavy (nearly 1 lb. each, like Classic's feet) BBC brass cones attached to the PD-444 base by double-adhesive Herbie's Grungebuster dots, and the down-pointing cones sit in receiving cups that in turn fit perfectly on top of Aurios Classic media bearings.

Result? Vinyl sound that is firmly planted, digs deep, is loaded with tone, dynamically vivid, spatially generous as appropriate to the recording, and alive with realistic transient clarity. I will keep this sound over any belt-drive turntable I've owned. I do believe it can be exceeded in some significant ways for much more money by a contemporary belt or thread-drive design, but then too there's the ~$8,000 Brinkmann Oasis to consider. It is considerabily more difficult for an entrepreneurial company, usually undercapitalized or bootstrapped, to design and bring to market a well-executed direct drive turntable. What would a Luxman PD-444 that cost $795 in 1978 cost if developed and introduced today? In hifi economics it would be squarely in the realm of high end.

Phil
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