The necessity for absolute tt speed control

[morricab]

And about the same as SME.

Any idea about the exact motor type? The current model says it has a 3 phase, 8 pole, outrunner (external rotor) design that uses a microprocessor controlled feedback loop. Don't know if that is only the newest models or how far back in time that goes...how old is yours?

I think it is important to note that they are not just relying on a clean 50Hz AC with a synchronous motor...they are doing something significantly more advanced.

Funny thing was, I had a friend with a 20/2 (not sure the age) and when I first got my Allnic Speednic we measured it and found that it was not very accurate (but it was adjustable) but that with a record playing we could visibly see some fluctuations in the speed (the Speednic can be used while playing a record...quite useful to see if needle drag is affecting your speed). I think this was an older model so it could have less sophisticated motor and speed control than is current or yours...so I don't think it can necessarily be reflective of your TT.

We tried this on other TTs and only the SME was so visibly changing (others tried: Yamaha GT-2000, Voyd "The Voyd", Transrotor Turbillon with decoupled magnetic drive, Lenco L75, Luxman PD-444, Reed 1C in rim drive mode) but the Transrotor need some adjustment to get the speed correct...then it was stable under load.

 

[Vienna]

Any idea about the exact motor type? The current model says it has a 3 phase, 8 pole, outrunner (external rotor) design that uses a microprocessor controlled feedback loop. Don't know if that is only the newest models or how far back in time that goes...how old is yours?

I think it is important to note that they are not just relying on a clean 50Hz AC with a synchronous motor...they are doing something significantly more advanced.

Funny thing was, I had a friend with a 20/2 (not sure the age) and when I first got my Allnic Speednic we measured it and found that it was not very accurate (but it was adjustable) but that with a record playing we could visibly see some fluctuations in the speed (the Speednic can be used while playing a record...quite useful to see if needle drag is affecting your speed). I think this was an older model so it could have less sophisticated motor and speed control than is current or yours...so I don't think it can necessarily be reflective of your TT.

We tried this on other TTs and only the SME was so visibly changing (others tried: Yamaha GT-2000, Voyd "The Voyd", Transrotor Turbillon with decoupled magnetic drive, Lenco L75, Luxman PD-444, Reed 1C in rim drive mode) but the Transrotor need some adjustment to get the speed correct...then it was stable under load.

Two years ago i was considering 30/12 and had a demo at my home. It was using hall sensors and indeed the measurements were disappointing. Some months ago i was invited in an event of SME new dealership, the Synergy was measuring worse

 

[PeterA]

Brad, my former SME is 9 years old. 2012. I was reporting results I read in one of the British review magazines I think hi-fi news about the wow and flutter and rumble figures of the SME model 30/12. I just noticed that the figures are almost identical to the tecDAS air force one and three. I sold my SME.

 

[Lagonda]

That may depend on what counts as improvement in motor design.

Slotless stator construction or slotless motors open up design opportunites for turntable makers by freeing them from dealing with torque ripple or other cogging issues and not requiring heavy platters or flywheels to address those issues.

Put your music on high capacity and high quality hard drives? The just means more high capacity and high quality hard drives for redundancy and duplexed Raid 0 backup.

I have seen, listened and experienced that one of the fundamental factors of great tt sound is the accurate speed and stability.

This is resulting in correct timing. Correct timing is an attribute which can only be appreciated the moment that will be experienced for the first time.

The inaccurate and unstable speed means timing errors, the higher the speed and stability variation, the higher the timing errors will be. (perhaps there are listeners who like this, I know people who are enjoying the distorted sound from misaligned and worn cartridges)

It’s strange how we do care about the jitter, measured in picoseconds (deviation of time between the digital and analog samples ), in the digital music reproduction, the moment that many intentionally diminishing the importance of the wrong timing on the analogue reproduction.

P.S.1 I have auditioned many turntables the last four years. Some of them with noisy motors others with very silent ones. Always the turntables (of similar specs and level) with more silent motors were yielding less vibrations and resonance measurements; and acoustically more detail retrieval, better dynamics and separation.

P.S2, Power supplies are a strange thing. A year ago Bill Carlin made me a drive with two BLDC motors driven by Class D amplifier, to replace my Hurst based motors driven by VPI ADS. The sound improvement was phenomenal. He later made for me a high biased Class AB amplifier to drive the motors and again I was amazed with the sound improvement. When I replaced the switching power supply with Keces linear one, again the improvement was huge.

Currently with Brinkmann Ront tube power supply, I am experiencing that different rectifiers are providing different sound. The Metal Base GZ34 is the best by far with great dynamics and dimensionality followed by the red lined Mullard GZ34. Sovtek is providing the worse muddy sound ever and the solid state Brinkmann BZ34 rectifier dynamic but lifeless flat sound. I don’t know whether there is a scientific explanation for this but the differences are easy to hear.

Fundamentally i agree with you about the affect of speed variation on timing, and may i add even on drive and rhythm. But i also believe there is a threshold where the last decimals on the RoadRunner become unimportant , the micro variations of cogging, torque ripple and feedback adjustments are much more detrimental to the music signal. And apparently Brinkmann do too, they have gone to great lengths to reduce and eliminate these problems including flywheel and heavy platter. Yes measurements are good, but in audio the best sound, and magic often lies somewhere between good measurements and listening. It seems the Balanced could have even better measurements with feedback and a controller with tighter grip, but Helmut listened and preferred the sound of a tube controller, and no feedback. Your own preference of the Metal base GZ34 to the other offerings also indicate that there is something going on that can not quite be captured by measurements As for speed variations, the R2R recorders that some of the best recordings where made with often had notoriously unstable speed as they wore out of spec, on some recordings you can hear it, but on most it lies under the threshold of what we hear.

 

[spiritofmusic]

So Milan, what is the Monaco 2.0 doing so right that an extra 0.000.... speed precision leads to tangible additional realism for Tim over his previous 1.5?

 

[morricab]

So Milan, what is the Monaco 2.0 doing so right that an extra 0.000.... speed precision leads to tangible additional realism for Tim over his previous 1.5?

I heard this Monaco 2.0 and it was pretty darn good!

 

[Lagonda]

So Milan, what is the Monaco 2.0 doing so right that an extra 0.000.... speed precision leads to tangible additional realism for Tim over his previous 1.5?

I am not a expert, but maybe they have gotten the speed and application of feedback/correction that is so heavily relied on in this type of drivetrain just right, those very important micro variations Some of the best DD drives have until now ( MikeL. schooled me recently ) been using relative heavy platters as part of their design, maybe the Monaco has gotten the processing to the point where it can be done with a light platter.

 

[Mike Lavigne]

I am not a expert, but maybe they have gotten the speed and application of feedback/correction that is so heavily relied on in this type of drivetrain just right, those very important micro variations Some of the best DD drives have until now ( MikeL. schooled me recently ) been using relative heavy platters as part of their design, maybe the Monaco has gotten the processing to the point where it can be done with a light platter.

i do believe that platter mass has a tipping point of needed inertia. below which groove modulation has an unacceptable effect. likely steady-ness too is involved. i'm sure platter weight location/distribution, bearing type and drive type move this tipping point around as to how heavy is heavy enough.

Win mentioned that part of his design approach was to place the platter weight on the outside of the platter to attain the belt drive sort of ease and inertia with his idler drive design.

 

[morricab]

I am not a expert, but maybe they have gotten the speed and application of feedback/correction that is so heavily relied on in this type of drivetrain just right, those very important micro variations Some of the best DD drives have until now ( MikeL. schooled me recently ) been using relative heavy platters as part of their design, maybe the Monaco has gotten the processing to the point where it can be done with a light platter.

It's still a 6Kg platter...not that light...the chassis, which is out of carbon fiber, should be very light.

 

[Lagonda]

It's still a 6Kg platter...not that light...the chassis, which is out of carbon fiber, should be very light.

6 Kg, i have record weighs that are heavier !

 

[spiritofmusic]

Milan, are you weight training at 3am again?

 

[Lagonda]

Milan, are you weight training at 3am again?

Combining exercise and vinyl listening is the only way i get a workout done these days Marc

 

[morricab]

i do believe that platter mass has a tipping point of needed inertia. below which groove modulation has an unacceptable effect. likely steady-ness too is involved. i'm sure platter weight location/distribution, bearing type and drive type move this tipping point around as to how heavy is heavy enough.

Win mentioned that part of his design approach was to place the platter weight on the outside of the platter to attain the belt drive sort of ease and inertia with his idler drive design.

This is why the Yamaha GT-2000 (1982...perhaps Win was inspired by this platter?) has an oversized platter where they made the platter such that it has extra mass at the very outside of the platter to increase inertia. The specified inertia was 1.2t/cm2 with the 6kg platter...significantly higher with the 18Kg optional platter.




The original platter is 6Kg and the optional YGT-1 platter (the gun metal version ) is 18Kg. The bearing was over-engineered to allow the extra weight without modification.

That intertia from weight and platter design, coreless/slotless 4 phase motor and sophisticated bi-directional servo controller gave very good specs and a very smooth and powerful sound (noise of -85db is among the very best ever).

 

[morricab]

6 Kg, i have record weighs that are heavier !

Too much mass also has it's downsides...

 

[Lagonda]

This is why the Yamaha GT-2000 (1982...perhaps Win was inspired by this platter?) has an oversized platter where they made the platter such that it has extra mass at the very outside of the platter to increase inertia. The specified inertia was 1.2t/cm2 with the 6kg platter...significantly higher with the 18Kg optional platter.
View attachment 75784

View attachment 75785

The original platter is 6Kg and the optional YGT-1 platter (the gun metal version ) is 18Kg. The bearing was over-engineered to allow the extra weight without modification.

That intertia from weight and platter design, coreless/slotless 4 phase motor and sophisticated bi-directional servo controller gave very good specs and a very smooth and powerful sound (noise of -85db is among the very best ever).

Looks pretty cool too !

 

[morricab]

Looks pretty cool too !

The inner ring is the size of a 33 1/3 record. It is funny using a TT with a "normal" size platter, which looks so small!

 

[Lagonda]

Too much mass also has it's downsides...

To heavy record weights sound like crap, i found out the hard way, forgot to ask David first

 

[morricab]

To heavy record weights sound like crap, i found out the hard way, forgot to ask David first

I use vacuum holddown...

 

[microstrip]

Two years ago i was considering 30/12 and had a demo at my home. It was using hall sensors and indeed the measurements were disappointing. Some months ago i was invited in an event of SME new dealership, the Synergy was measuring worse

Can we know exactly what measurements were disappointing?

 

[microstrip]

i do believe that platter mass has a tipping point of needed inertia. below which groove modulation has an unacceptable effect. likely steady-ness too is involved. i'm sure platter weight location/distribution, bearing type and drive type move this tipping point around as to how heavy is heavy enough.

Win mentioned that part of his design approach was to place the platter weight on the outside of the platter to attain the belt drive sort of ease and inertia with his idler drive design.

Mike,

If we scale the forces created by the stylus tracking with the forces involved in the lacquer cutter when creating the groove we would conclude that the cutter machine platter should have many hundred kilograms or even tonnes ...

Although inertia can be very important to smooth the drive system fluctuations, the effects of groove modulation on the signal were never measured or proved. Surely high modulation increases drag, but it was were never shown to induce noise (micro acceleration and braking) in the platter movement. Mass and dimensions can also have a very important role in controlling platter resonances and absorption of the vinyl vibrations induced by the stylus reading.

Anyway, if audiophiles were really concerned with motor coupling to the platter they would ask for an hydrokinetic coupling, like those used in the old Newmann disk cutting lathes. Can we even imagine owning a Newmann VMS80 to play our cherished LPs?