Update On 3rd Version of ADS?

[Johnny]

Actually we have a gorgeous 3D rendering of the chassis as well with a lot of other fantastic steps forward... but I'm not posting anything until I'm holding a near finished prototype in my hands

How about posting what features the new motor controller will have over the standard offering?

[Phoenix Engineering]

Working with AC sync motors is a dry hole IME. Even running them in dual phase is fairly limited in what you can accomplish. Beside the fact that these motors are cheaply built and have a number of mechanical issues, there is only so much you can do by controlling frequency, phase and voltage in a quadrature drive. Compared to 3 phase AC synch motors, it's like taking a shower with your clothes on. I've been running a 3 phase motor and controller for ~2 years and there is no comparison, it is night and day: No vibration, no belt squeal, 100:1 speed range with loads of available torque (even at 78 RPM), 33/45/78 RPM with a single pulley spindle, and speed easily controlled with frequency to 0.0005 Hz resolution with tachometer feedback.

Ask HW; the DD uses a 3 phase motor, although it is servo controlled which is similar to the hunting algorithms of the 70's direct drive tables (albeit with a heavy platter). This is totally unnecessary and can be handled so much more elegantly with the right controller. Others in this industry have discovered what a proper belt drive system is capable of. In time, the rest of the field will follow or get left behind.

[Packgrog]

I've been running a 3 phase motor and controller for ~2 years and there is no comparison, it is night and day: No vibration, no belt squeal, 100:1 speed range with loads of available torque (even at 78 RPM), 33/45/78 RPM with a single pulley spindle, and speed easily controlled with frequency to 0.0005 Hz resolution with tachometer feedback. ... Others in this industry have discovered what a proper belt drive system is capable of. In time, the rest of the field will follow or get left behind.

Or hopefully some 3rd party industrious soul can provide plug & play 3 phase motors with controllers at the same scale to fill that gap, like you all-too-briefly did with the Falcon/Eagle/Roadrunner, for those of us that lack the ability to build such things themselves. And that's not meant as snark, either: I'd *LOVE* to try something like your DIY motor setup, but I simply lack the skill (and necessary equipment/available training) to build it. I suspect that VPI's motor choices may be limited to providers that can meet their scale & cost demands (pure conjecture on my part), and their R&D focus seems to be elsewhere. But they're hardly against 3rd-party mods/upgrades, and I imagine they'd praise someone that provided a nice alternative for their user base.

[Number9]

Others in this industry have discovered what a proper belt drive system is capable of. In time, the rest of the field will follow or get left behind.

Well stated Bill. The three-phase drive is definitely the future. All that remains to happen in order for this to become accepted industry best practice is for Ivor Thiefenbrun to learn of this and then convince himself that it was all his very own brilliant idea and add the requisite number of zeros to the price of the technology.

Everything revealed during the protracted series of listening tests during the development of my Turntable Control Instrument pointed to the fact that the three-phase approach as being inherently superior.

I made a commercial decision to release the synchronous only implementation initially in order to people, even those without much technical prowess, to extract the maximum sonic performance from their existing turntable, as did you.

Fortunately, because we designed the waveform generator board to provide biphase drive for two motors, with precise control of the phase relationships between all four waveforms, it makes developing a three-phase output module, fully compatible with the existing hardware largely a firmware issue.

My plan is to develop a three-phase output module to complement the existing range of interchangeable modules. At present, while we have identified what we believe to be a workable chipset and some candidate motors. there is still a lot to do do, but I hope we can begin field trials in the next couple of months. I'm hoping to keep the price of the three-phase upgrade to around $US300 plus motor. In order the address the value concerns of Linn owners, we also make the same module available for $US3000.

Stay tuned!
Steve

[Stringreen]

What's wrong with the SDS....why would I want to change to an ADS?

[Mr_Putty]

Offer me a kit with full instructions and reasonable price. And I will be all ears!