Why three motors?

Yeah, Hiho did alarmed me. For a while, I thought my 3 months TW Raven is obsolete.

I have never listened to any of these 3-motor tables, but the configuration shown, where the belt contacts the platter on only one side of the "triangle" would seem to be a worst-case set-up for "belt creep", as first described (to me) by Mark Kelly on Vinyl Asylum. In fact, to minimize belt creep, the belt should contact the platter over as much of its circumference as possible, e.g., the pulley of a single motor should be snug up as close as possible to the edge of the platter. Or you can use a capstan-like extra pulley to keep the belt in contact with the platter a la the Artemis turntable. (I think that's the one with the capstan. Could be wrong.) Other solutions or ways to at least ameliorate belt creep have been proposed but are not commercially available. But 3 motors makes no sense to me.

Donwunder: "Where did you get that information from?? Exactly where has TW changed course??"

I have seen the 3-motors version on their website before and now it's NOT listed on their website - http://www.tw-acustic.de/engl/turntables - so I made an assumption that they are not offering that anymore. I apologize for not making that clear earlier. But why is that option not on the website anymore, just curious? Let's say they didn't change course, the question remains what is the engineering reason behind such unconventional approach. Any suggestions for the discussion?

Speaking of 3 motors, their flagship Raven Black Night uses 3 motors in a single housing with THREE pulleys, which in itself a curious design. Is it to increase triple the torque and/or to combat belt slip or belt creep, etc?

Lewm: "the configuration shown, where the belt contacts the platter on only one side of the "triangle" would seem to be a worst-case set-up for "belt creep"...... 3 motors makes no sense to me."

Lewm, perhaps you can get some hint from their writing about the Black Night, if not the AC3:

"Thanks to the three-motor drive and the battery power supply, the Raven Black Night does its job with poise, serenity and composure, yet just like the other TW-Acustic turntables, it is highly dynamic, involving and rich in timbre. The Raven Black Night is incredibly musical, its spatial presentation is so three-dimensional and tangible that the music is always reproduced with the utmost authenticity."

You see, it just does its job.

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I am completely ignorant of the engineering principles that govern "poise, serenity, and composure". In particular, I am weak on the subject of serenity.

Seriously, the tables in question are probably superb sounding. I mean to cast no aspersions. Here we are talking about the why of it.

About the TW website, what I meant is that I didn't see the listing or any prompt button for the AC3. As seen in the picture, obviously they still offer the three motor option. Once again, I apologize for the confusion and my carelessness. Yes, TW STILL makes a 3-motor turntable with only one side of the belt touching the platter. Below is description of the system:

Three-motor drive for Raven and Raven AC turntables / Technical details:

Our three motors run absolutely syncronous thanks to a sophisticated motor control
The diameters of the drive pulleys are accurate to within half a hundredth of a millimetre
The drive belt thickness is ground to a tolerance of one hundredth of a millimetre

We have taken the advantages of our unique drive system to the limit and have developed a three-motor drive for the Raven One and Raven AC. We have achieved perfect syncronicity between all three motors with our new, highly developed motor control system.

The extremely precisely machined drive belt, coupled with finely toleranced and matched pulleys give the concept the optimal basis for the precision we demand. If you were of the opinion that the Raven's drive system was unique, then of course you were right! But the new three-motor drive picks up where our unique single motor drive leaves off. The Raven or Raven AC is now available as a three-motor version. Of course, any existing Raven One or Raven AC can also be upgraded.

There's no mention of the belt configuration. Can we get back to the why now? Anyone?

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