Da Vinci AAS Gabriel

I still stand by any isolation system that isolates the motors and the turntable in 2 separate domains (2 separate isolation devices) will in fact induce wow & flutter as the turntable & motor will vibrate independent of each other. This in itself must be considered. So, then we can postulate the best isolation will be a wall mounted stand with the motor suspended apart from the turntable. Unfortunately not a possibility for me and for most.

So back to basics, it is important in the design of any turntable that the motor has as little vibration as possible. This can be measured but in fact no currently published magazines in the US ever do such a measurement. Neither do they measure speed accuracy. But if I remember correctly there are some magazines in Europe which do such measurements. I wonder what motors measured best in terms of speed stability (at the platter, not motor) and in terms of vibration at the motor directly and finally how much vibration is transmitted to the platter/LP from the motor. All good questions. So now, I will also suggest a good isolation system or stand will in fact absorb vibration from the motor and also keep it away from the all important stylus/LP interface.

Now, on to the theory behind more motors. I have thought extensively about this. I am by no means an expert but put forward the following points.

Syncronizing multiple motors does have its challenges and might lead to the less is more philosophy from this perspective.

While a motor pulls the belt on one side of the pully, it in fact pushes the belt & creates slack on the other side of the pully

Using 3 motors will have a "take up motor" that will pull the belt and reduce the slack amount of belt being pushed.

Also 3 motors allows for less contact area between the platter and belt. This results in less surface resistance and less induced vibration from the motor through the belt to the platter. But also, this results in less realized torque at the platter, as there is less contact between the belt and platter. Again 2 items in conflict with each other. Ultimately you will need to let your ears be the judge. I know I have, and have spoken privately about my conclusions with my audio friends.

Back to isolation, I am in agreement that more weight on top of a stand will give you a lower resonant frequency but I think there must be some way to come to an ideal number. I forget my physics as it is over 20 years ago but for anything to isolate it must vibrate. If it is too stiff it won't work. Just think of the difference between a Cadillac suspension compared to a sports car or BMW/Audi for the Germans. One is softer on your but while the other wobbles more. Ultimately I find the stiff suspension of a car better, but ask my father and he would say to opposite.

I am using springs for my stand as many have seen. I wonder if reducing the # of springs will improve isolation. I know reducing the mass on top of the stand sounded worse as the resonant frequency rose too high. But then I might as well use less springs. I wish I remembered my spring constants etc.

That's an interesting thought Dgad. I wonder if Thomas thought of using one motor and 2 passive pulleys. Arthur K from Funk Firm uses such a scheme and calls it Vector Drive.

Dgad, suspension in cars and isolation from periphery vibrating ground (shelves, floor, wall) has very little to do with each other.

While your thoughts do indeed reflect some popular high-end audio "theories", they are not on a solid physical basis and are not hitting the topic.

In resonance frequency and the isolation from parasite vibration "we" are - should..... - seek a resonance frequency below 1 Hz.
Check the website of Minus-K and other companies dealing and specializing in this to get some insight into this topic.

3 motors will introduce - as they can hardly be synchrozised - 3 sources of error into a rotating system.
To this just add the belts which do elastically speed up and slow down - i.e. introducing wow and flutter - the platter and you have a rotating system which is the very opposite of constant unaltered speed.

You don't hear that the TT sounds worse with multiple motors?
Most likely because the bearing is now force free if the motors are situated in a manner that the bearing is horizontal free of force or close to that.
As this will "better" the sound, most will credit this improvement to the multiple motor situation.
However - using only 1 motor and 2 counter-bearings in the positions of the other "motors" instead will further improve the sonic presentation.

Multiple motors is the very same conceptional error as with multi-tubes or multi-transistors output-stages. As the individual tube/transistor/motor is always NOT identical in all parameters to its "comrades" the resulting "signal" is itself not homogenous but "wobbling".
This is something to think about before telling me how wrong I am.

It has to do with strict logic and theoretical model without prejudice.
We should have some members here who do enjoy exactly these ...........

Ducati Rider,

Black Night get close and the fact that the motors are next to each other & contacting the belt almost at one point should be the best of all worlds. Syncronization would never be a problem in such a design.

Dertonarm,

I never said what I like better in these forums between multiple motors or not. Only in private, as my conclusions are not 100% verified. Further 3 motors in theory, can compensate for error as well. They would average the error of any one motor. Again, I am back to the argument there are no absolutes/

As for electron Microscopes and tonearms etc. I think we have to take into account 2 types of vibration. One would be "micro vibrations" and one would be Macro. There can be no one solution that is perfect for all scenarios. Imagine a sprung wood floor. A different isolation option would be needed for isolating footfalls as compared to airborne noise.

Dgad, any isolation platform deals with mechanical vibrations only - airborne pressure (loudspeaker etc.) do of course need different measures.
A isolation platform with a resonance frequency below 1 Hz however does deal with microvibrations as well as footfalls.