Esoteric Grandioso T1 turntable arrives; G1X Master Clock coming.

[tima]

The speed probably is changing but less than your tools can measure.

Not according to Esoteric

View attachment 107365

Not according to Esoteric, soley based on the claim of "absolutely precise platter rotation". I'd like to know what that means. The implication of those words is perfect 33-1/3 rpm, but they don't say that. I'm not questioning their marketing, just looking for a more in depth explanation.

 

[andromedaaudio]

The speed probably is changing but less than your tools can measure.

Probable ???

, just looking for a more in depth explanation.

Me too

 

[morricab]

I'm trying to follow your discussion with Mike and Carlos. Maybe it is mentioned but this is the first I've read of speed correction and what you refer to as "the application time of speed corrections". I'm guessing the latter refers to the time between the detection of a need for correction and the correction instruction being issued. There is also the question of the number of corrections that can be issued in a given amount of time.

How do you believe speed monitoring is done -- what is monitored and what is the frequency of that monitoring, that is how many data points are gathered in what amount of time? I don't expect we have that last piece of information unless Esoteric discloses it.

I'm guessing (?) that the distance of the magnetic rotor to the platter and the ensuing torque adjustment and effect are mostly separate from the issue of speed control.

That distance probably affects the need for correction. I have seen no mention of how they monitor the speed (optical encoder, magnetic tape like Denon, hall elements etc.). One would assume a closed loop system of some kind or else the point of an exotic clock seems lost to me.

 

[morricab]

Not according to Esoteric, soley based on the claim of "absolutely precise platter rotation". I'd like to know what that means. The implication of those words is perfect 33-1/3 rpm, but they don't say that. I'm not questioning their marketing, just looking for a more in depth explanation.

I am questioning it just like I would a DAC claiming absolutely zero jitter. The physics just doesn’t support either assertion.

 

[tima]

That distance probably affects the need for correction. I have seen no mention of how they monitor the speed (optical encoder, magnetic tape like Denon, hall elements etc.). One would assume a closed loop system of some kind or else the point of an exotic clock seems lost to me.

Presumably the special clock is the reference for time / timing going out farther to the right of the decimal point. It provides data. Presumably there is also a programmed computer/CPU that uses the clock data along with monitoring input data to issue instructions to the motor. Perhaps the closer the magnetic rotor is to the platter the less uptake time on the platter's part to a speed adjustment in the rotor. If they measure both rotor speed and platter speed, they will know what that time difference is in maintaining sync. Speculation on my part.

I am questioning it [the claim of "absolutely precise platter rotation"] just like I would a DAC claiming absolutely zero jitter. The physics just doesn’t support either assertion.

Yes, of course. I was just willing to let marketing be marketing.

Mike I trust you are okay with us speculating on this new table in your thread.

 

[andromedaaudio]

• The speed stability of the lathe is achieved by massive moving parts which put a great demand on the bearings which support them. It has been possible to produce the main load supporting bearing in the reproduction turntable with a level of rumble performance better than that achievable in the lathe for many years4. Thus we can say that the lower bound of rumble performance is set by the lathe and is imprinted forever in the medium itself. This focuses attention on rumble filtering which is only achievable with digital, non-causal filters without introducing audible phase-shift NOT present on the recording.

I assume all mikes reproduction TT and most of the high end reproduction TT that are used on WBF would fall into the category .
Meaning the Lathe rumble performance is already engraved in the laquer and will be the limit as to what can be achieved.

Disc-cutting lathes

Stereo Lab recording lathes record lathes cutting lathes

pspatialaudio.com

 

[Mike Lavigne]

Presumably the special clock is the reference for time / timing going out farther to the right of the decimal point. It provides data. Presumably there is also a programmed computer/CPU that uses the clock data along with monitoring input data to issue instructions to the motor. Perhaps the closer the magnetic rotor is to the platter the less uptake time on the platter's part to a speed adjustment in the rotor. If they measure both rotor speed and platter speed, they will know what that time difference is in maintaining sync. Speculation on my part.

the plinth/bearing/platter assembly has zero connection to the motor/power supply. it is passive completely. the motor box has everything switchable and connectable. so there is no measuring going on the platter it self. it's a mechanical (standing off through magnetic force) connection only. FWIW the CS Port plinth is the same other than it uses a belt, not magnetic force, and also has air being pumped in. but nothing wired or measured.

Yes, of course. I was just willing to let marketing be marketing.

right on speed is what i hear. but healthy skepticism is expected. absolute speed is a relative term in reality. a bit of marketing but true 'enough' to fit i think. let's see what Fremer's measureing toys tell us in his review. might be world class absolute speed. hope he does it with and without the clock.

Mike I trust you are okay with us speculating on this new table in your thread.

by all means, as long as it's relevant to the T1. and the personal type comments are minimal so not to distract. have fun. i'm learning and the design is very interesting on many levels and worth wringing out a bit.

i reserve the right to whine about it later.

 

[Mike Lavigne]

playing around with the torque adjustment this morning on a piano concerto.

there is a 1mm adjustment range, with 4 turns of the micrometer adjustment between the 'soft/warm' at 2mm and the 'firm/neutral' at 3mm.

definitely more languorous/relaxed and maybe even a very very slightly lower noise floor at the 2mm 'soft/warm' setting. you hear slightly farther into the soundstage. the bass is a bit more majestic, expansive, expressive in an emotional sense. but tone and grainlessness is the same. so the speed is the same. flow is good.

at the 3mm setting, more tension, more propulsion, more focused, more touch, notes are more connected. like a slightly different pianist. the aspects that are less comparatively are not less in a negative sense, but those aspects don't come out as obviously. tone and grainlessness still the same.

musically equivalent so far to me.

i suspect i will eventually have spots on the dial i prefer for certain music. i think most listeners will gravitate to the warmer settings. but i think it will be cartridge dependent. the very neutral, if clear window Audio Technica probably will be best with some added warmth. still don't have my measure of the Ikeda arm and it's character.

enough for today......a friend/WBF member is coming over later and if he is in the mood we will play around some more with this.

 

[mtemur]

This focuses attention on rumble filtering which is only achievable with digital, non-causal filters without introducing audible phase-shift NOT present on the recording.

Analog filters introduce phase shift, that's true, but same is also true for digital filters. It is possible to minimize phase shift on digital filters but this time impulse response gets a big hit. Pre or post ringing or both becomes being etched to the original signal. Pre and post ringing are artificial and can be very disturbing. I prefer the sound of analog filters.

Pre and post ringing also applies for oversampling. Some people -including myself- prefer more pleasing sound of Non Over Sampling mode on a DAC even frequency response starts to roll off early.

The speed stability of the lathe is achieved by massive moving parts which put a great demand on the bearings which support them. It has been possible to produce the main load supporting bearing in the reproduction turntable with a level of rumble performance better than that achievable in the lathe for many years4.

I don't know if hi-end turntables have better bearings and lower rumble compared to lathes but I hope they do. That doesn't mean lathes have high rumble to be an area of concern. Lathes have oversized/over-engineered bearings which were well machined and manufactured. I wouldn't worry about that.

 

[mtemur]

I'm guessing (?) that the distance of the magnetic rotor to the platter and the ensuing torque adjustment and effect are mostly separate from the issue of speed control.

I agree with you.

How do you believe speed monitoring is done -- what is monitored and what is the frequency of that monitoring, that is how many data points are gathered in what amount of time? I don't expect we have that last piece of information unless Esoteric discloses it.

I don't know Esoteric's implementation and what type of motor is used, AC or DC. So I can only share my guess on this:
I believe there is a software, probably running on Linux SOC that is responsible for driving and controlling the motor. Software makes decisions on correction signal depending on the difference between the motor speed and platter speed. For example if platter is stopped, not spinning and 33.3rpm is pressed then software sends aggressive signals to quickly reach 33.3 rpm but if platter is spinning at 33rpm then software doesn't need to take aggressive measures to compensate for 0.3 rpm difference. Those motor control signals can vary in waveform and voltage and there can be infinite combinations. That's the beauty of using a software, it can judge readings from platter and motor and produce appropriate motor control signals depending on the situation. I believe those motor control signals are digitally produced by software then converted to analog and amplified. That certainly doesn't make the turntable in any way digital. I Know OMA K3 uses software to control the motor but apart from that I don't know OMA's implementation either.

Maybe it is mentioned but this is the first I've read of speed correction and what you refer to as "the application time of speed corrections". I'm guessing the latter refers to the time between the detection of a need for correction and the correction instruction being issued. There is also the question of the number of corrections that can be issued in a given amount of time.

I mentioned it regarding magnetic coupling between pulley and platter. Since magnetic coupling is not a physical connection, the pulley and platter are not locked like gears, the existence of slip between them is inevitable. When gap between them increases slippage increases too. Increase in slippage will lead to an increased duration of applied correctional signal. When the gap decreases slippage decreases as well as duration of signal cause platter will reach ordered speed by software more quickly. Shorter the gap higher the magnetic coupling and lower the slippage.

 

[andromedaaudio]

It defenetively looks cool micrometer adjustment .

(Something for wilson audio adjusting those mids and tw with a micrometer )

 

[morricab]

I agree with you.


I don't know Esoteric's implementation and what type of motor is used, AC or DC. So I can only share my guess on this:
I believe there is a software, probably running on Linux SOC that is responsible for driving and controlling the motor. Software makes decisions on correction signal depending on the difference between the motor speed and platter speed. For example if platter is stopped, not spinning and 33.3rpm is pressed then software sends aggressive signals to quickly reach 33.3 rpm but if platter is spinning at 33rpm then software doesn't need to take aggressive measures to compensate for 0.3 rpm difference. Those motor control signals can vary in waveform and voltage and there can be infinite combinations. That's the beauty of using a software, it can judge readings from platter and motor and produce appropriate motor control signals depending on the situation. I believe those motor control signals are digitally produced by software then converted to analog and amplified. That certainly doesn't make the turntable in any way digital. I Know OMA K3 uses software to control the motor but apart from that I don't know OMA's implementation either.


I mentioned it regarding magnetic coupling between pulley and platter. Since magnetic coupling is not a physical connection, the pulley and platter are not locked like gears, the existence of slip between them is inevitable. When gap between them increases slippage increases too. Increase in slippage will lead to an increased duration of applied correctional signal. When the gap decreases slippage decreases as well as duration of signal cause platter will reach ordered speed by software more quickly. Shorter the gap higher the magnetic coupling and lower the slippage.

I think when the magnets are very close to the platter there will be no slip to speak of and it will be like virtual gears, where the platter is at the mercy of the drive system. Move it away and the platter inertia can begin to assert itself.

 

[Mike Lavigne]

I don't know Esoteric's implementation and what type of motor is used, AC or DC.

power supply supplies DC to the motor.

 

[mtemur]

power supply supplies DC to the motor.

If you refer to the sentence below from Esoteric's page it doesn't say the motor is DC. It explains that required DC for control unit is supplied from an independent power supply and therefor possible interference with motor is eliminated.

"Furthermore, by supplying extremely pure DC from an independent
power supply unit, the transmission of unwanted vibrations to the motor unit is minimized."

A control unit, a software running SOC is a small computer and it runs on DC. Since it's a computer it can produce any signal for example 50Hz 3 phase. After that an amplifier amplifies that signal for example 19V and use it to drive 3 phase AC motor. Amplifier also runs on DC but amplifies AC. if a speed change is required then computer changes the frequency, 49-50-51Hz etc. I used a turntable with a simple version of what I described above. Besides producing AC a computer can easily produce DC too. So it can use a DC motor as well.

My guess is DC motor rather than AC but I couldn't find info to confirm maybe you can. Maybe it's written on manual or over the case.

 

[PeterA]

playing around with the torque adjustment this morning on a piano concerto.

there is a 1mm adjustment range, with 4 turns of the micrometer adjustment between the 'soft/warm' at 2mm and the 'firm/neutral' at 3mm.

definitely more languorous/relaxed and maybe even a very very slightly lower noise floor at the 2mm 'soft/warm' setting. you hear slightly farther into the soundstage. the bass is a bit more majestic, expansive, expressive in an emotional sense. but tone and grainlessness is the same. so the speed is the same. flow is good.

at the 3mm setting, more tension, more propulsion, more focused, more touch, notes are more connected. like a slightly different pianist. the aspects that are less comparatively are not less in a negative sense, but those aspects don't come out as obviously. tone and grainlessness still the same.

musically equivalent so far to me.

thank you Mike for these listening impressions. They are the opposite of what I would’ve expected. I thought the larger 3 mm gap would create the softer warmer sound and the smaller 2 mm gap would’ve been more tight and hard sounding. This is what happened with my string tension. I guess you are experiencing the opposite.

 

[emoonie]

playing around with the torque adjustment this morning on a piano concerto.

there is a 1mm adjustment range, with 4 turns of the micrometer adjustment between the 'soft/warm' at 2mm and the 'firm/neutral' at 3mm.

definitely more languorous/relaxed and maybe even a very very slightly lower noise floor at the 2mm 'soft/warm' setting. you hear slightly farther into the soundstage. the bass is a bit more majestic, expansive, expressive in an emotional sense. but tone and grainlessness is the same. so the speed is the same. flow is good.

at the 3mm setting, more tension, more propulsion, more focused, more touch, notes are more connected. like a slightly different pianist. the aspects that are less comparatively are not less in a negative sense, but those aspects don't come out as obviously. tone and grainlessness still the same.

musically equivalent so far to me.

i suspect i will eventually have spots on the dial i prefer for certain music. i think most listeners will gravitate to the warmer settings. but i think it will be cartridge dependent. the very neutral, if clear window Audio Technica probably will be best with some added warmth. still don't have my measure of the Ikeda arm and it's character.

enough for today......a friend/WBF member is coming over later and if he is in the mood we will play around some more with this.

Hi Mike,
Thank you for further insights. So is the 'soft/warm' at 2mm farther away from the platter and the 'firm/neutral' at 3mm closer to the platter? So COOL to have that option.

 

[Mike Lavigne]

thank you Mike for these listening impressions. They are the opposite of what I would’ve expected. I thought the larger 3 mm gap would create the softer warmer sound and the smaller 2 mm gap would’ve been more tight and hard sounding. This is what happened with my string tension. I guess you are experiencing the opposite.

there is a (i assume threaded) piston inside the micrometer. as you turn the micrometer either direction, the piston extends toward from the platter or retracts from the platter. the mm marks are engraved on the piston, so 2mm is less extended than 3mm. these mm marks emerge from under the micrometer barrel, or retract inside the barrel, slowly as you turn the micrometer.

the barrel has 20 steps, it's 4 turns of the barrel between 2mm and 3mm. so you have 80 repeatable steps of adjustment, and you can be between steps too. very simple to use. and a high level of fit and finish, seems like it is a forever piece and works solidly. obviously one variable is the motor chassis position, so it is important to use the carbon fiber template to check the motor chassis position regularly, especially if you are doing investigations about this.

today a friend was here and playing around we were able to 'like' best 28 steps from 3mm/52 steps above 2mm. our process was to first do both extremes, then in the middle (40 steps either way) then 20 steps from 3mm, which we then preferred the middle step, so we slowly moved the micrometer until we had the best result.

we did not try the other direction from the middle since as we adjusted it toward 3mm from the middle it got better then worse.

that was my friend's preference, i was at the tt turning the barrel. we just wanted to go through the process to see how it worked.

no difference than dialing in a cartridge by ear.

we stopped there, only used one cut, so not any long term reference, but the process was simple. i need my reference tonearms and cartridges and try to determine what is what before i get too carried away with this, but it's quite interesting.

when i get serious about it i will have to keep a log and note my experiences to find the best spot(s) for the particular music....or.....mood.....or visitor.

hopefully i did not get too wordy and make it confusing. easy to see how it works, challenging to put into words.

 

[tima]

the plinth/bearing/platter assembly has zero connection to the motor/power supply. it is passive completely. the motor box has everything switchable and connectable. so there is no measuring going on the platter it self. it's a mechanical (standing off through magnetic force) connection only. FWIW the CS Port plinth is the same other than it uses a belt, not magnetic force, and also has air being pumped in. but nothing wired or measured.

I'm going on an assumption that there are two things spinning here. The magnetic rotor (or whatever is its accepted name) spins and the platter spins, with the former engaging the latter through magnetic force but no physical connection between them. From that alone I don't think it follows that the speed of either is not measured. Not trying to argue with you, just speculation.

It could be that:
a) both rotations are monitored and compared for accuracy, or
b) that neither is monitored or
c) that the magnetic rotor speed alone is monitored.

In the case of a) the platter speed data could be used as data input to control the magnetic rotor.
In the case of b) neither rotor nor platter is controlled, and
in c) the rotor speed alone is controlled.

b) is kinda saying the sytem is fool-proof and makes no mistakes, or at least it isn't checked for speed differential. c) says total confidence in the rotor platter magnetic connection such that if the motor is correct, the platter is correct.

My sense is to believe the a) scenario is in effect, but again speculation.

Of course none of that may be true and something altogether different may be happening.

I believe there is a software, probably running on Linux SOC that is responsible for driving and controlling the motor. Software makes decisions on correction signal depending on the difference between the motor speed and platter speed. For example if platter is stopped, not spinning and 33.3rpm is pressed then software sends aggressive signals to quickly reach 33.3 rpm but if platter is spinning at 33rpm then software doesn't need to take aggressive measures to compensate for 0.3 rpm difference. Those motor control signals can vary in waveform and voltage and there can be infinite combinations. That's the beauty of using a software, it can judge readings from platter and motor and produce appropriate motor control signals depending on the situation. I believe those motor control signals are digitally produced by software then converted to analog and amplified. That certainly doesn't make the turntable in any way digital. I Know OMA K3 uses software to control the motor but apart from that I don't know OMA's implementation either.

I understand and agree. Your sentence that I bolded assumes that platter speed is monitored. What you describe is similar to how the Monaco 2 works where both the measure (166,289/sec) and correction (1000/sec) gradients are much much smaller than your example. (I realize what you wrote is meant only as an example.) In that TT, the monitoring is done through direct platter measurement (, and using a 40 mips computer the motor voltage can be kept to a stable 33-1/3. I described it as using modern digital technology in the service of analog accuracy. That this TT has a computer doesn't bother me a whit; I mention it as a known example for discussion purposes.

Since magnetic coupling is not a physical connection, the pulley and platter are not locked like gears, the existence of slip between them is inevitable. When gap between them increases slippage increases too. Increase in slippage will lead to an increased duration of applied correctional signal. When the gap decreases slippage decreases as well as duration of signal cause platter will reach ordered speed by software more quickly. Shorter the gap higher the magnetic coupling and lower the slippage.

I understand. If that's the case the bottom line is correction/adjustment occurs.

let's see what Fremer's measureing toys tell us in his review. might be world class absolute speed. hope he does it with and without the clock.

He has pretty consistently used the 'platter speed' phone app (no longer available but there are similar) as his measuring toy in his reviews. (And no offense to anyone, it is a fun toy. Most use the gyroscope in a phone and different phones can yield different results.) He takes a screen print of its output and it looks convincing. (ref. here, here, etc.) Maybe now he has a different tool. Yes with and without clock.

 

[Bonesy Jonesy]

If the T1 TT is not accurately measuring the platter speed (ideally at 33 1/3 rpm assuming the records being played have also been cut at this precise speed....(another topic for discussion), then adding / bolting on motors with very expensive and accurate speed monitoring and operation becomes in a way academic ! If this is the case with the T1 then for me it is a flawed design, no matter how accurate the platter motor itself is at spinning at a constant 33 1/3rpm !

For such an expensive turntable with such a relatively high technology in operating platter motor speed, Esoteric should also have included a relatively high technology and possibly brand new method in directly measuring the actual platter speed for their T1 (as Grand Prix Audio have done on their TTs !) even if it meant the price of the TT going up say another US$20k for one if not the most important parameter for a TT to produce. Esoteric could have also introduced new technology in accurately measuring and monitoring the actual TT platter speed with a patent for this (as they did for their magnetic platter motor drive system).

Also using magnets for the platter drive system as the T1 does, may also possibly have an influence on the sound with the possibility that the cartridge may be picking up magnetic waves / electromagnetic forces being emitted from the T1's platter & motor drive system with a proportion that could be projecting towards the cartridge ?

As for changing the distance between the motor and the platter, maybe Esoteric included this feature to 'dial in' the platter speed to run exactly at 33 1/3 rpm (assuming one has the right and calibrated tools & instruments to also measure the platter speed to this very high accuracy). Of course changing the platter speed ever so slightly will change the sound to some degree or another.

Just my 2 pennies worth of thoughts on what at face value by looks alone is a lovely looking turntable !

 

[mtemur]

Also using magnets for the platter drive system as the T1 does, may also possibly have an influence on the sound with the possibility that the cartridge may be picking up magnetic waves / electromagnetic forces being emitted from the T1's platter & motor drive system with a proportion

Even if there wouldn’t be a magnetic coupling there will still be magnetic flux. Magnetic flux that comes from motor. There is a motor in every turntable and all motors run by magnetic propulsion. If you think magnetic influence is strong enough to be an area of concern I recommend starting with motor not the magnetic coupling.

IMHO I don’t think Esoteric turntable or others have any magnetic influence that needs to be addressed. Verdier turntables use bigger magnets to lift the platter without any issues for decades. I think magnetic influence on well engineered turntables is not an issue. Otherwise we should be talking about magnetic influence of speaker drivers first. Especially the bass.