Review: Grand Prix Audio • Monaco 2.0 Turntable

tima · Jun 24, 2018

morricab said:
I would only buy a DD turntable if the motor was a coreless design. From the website it is not clear that this TT fits that category. All the speed regulation in the world will not fix the inherent issues in a cored motor. Only a coreless motor can deliver continuous smooth torque.

Hi Morricab - it may be semantics ... I'm not sure. The GPA Web site indicates: "The proprietary slotless motor has an infinite pole design with a custom controller using 74,000 line encoder disc..."

Whenever I've talked with Alvin Lloyd about the new drive system he refers to the motor as a "slotless motor." I've not heard him use the term "coreless."

My 2.0 review had to pass the normal manufacturer's technical accuracy assesment: "Lloyd replaced the brushless 12-pole DC motor of the 1.5 with a custom-made slotless motor. Slotless motor designs place only copper phase coils in the air gap of the motor; the discontinuous iron teeth found in a slotted motor design (those used in most direct-drive ‘tables) are gone. This virtually eliminates cogging or cogging torque -- the bane of turntable motors. Torque becomes a function of the applied phase current, and current gets into the windings very fast. This means much smoother motion with greater torque linearity than a traditional slotted design, and much less vibration and noise."

My understanding of a coreless motor is one without an iron core that normally holds the coil. I read slotless motor manufacturer's also refer to their product as ironless. I'm not a motor design guru, but my sense is that "slotless" and "coreless" may not be distinct designs and here the words are used interchangeably, but I'm willing to be educated.

microstrip · Jun 24, 2018

morricab said:
I would only buy a DD turntable if the motor was a coreless design. From the website it is not clear that this TT fits that category. All the speed regulation in the world will not fix the inherent issues in a cored motor. Only a coreless motor can deliver continuous smooth torque.

IMHO this a dogmatic view on turntables, ignoring the complexity of a turntable and the capabilities of electronics.

What is considered one of the best sounding drive system in the world, the Neumann VMS 66/70 Vinyl Cutting Lathe uses a cored Technics SP-02 direct drive motor.

If a turntable would suffer from issues due to the cores they would show clearly in the wow and flutter measurement spectra - FFTs are very powerful tool and would easily detect a peak that would have a frequency that is a multiple of the rotation speed times the number of poles.

BTW, turntables can not be compared with the most usual motor applications, where efficiency and torque maximization are key issues. No one in high end cares about it.

All IMHO, YMMV.

Solypsa · Jun 24, 2018

microstrip said:
snip-

What is considered one of the best sounding drive system in the world, the Neumann VMS 66/70 Vinyl Cutting Lathe uses a cored Technics SP-02 direct drive motor.

-snip.

Actually they used a cored lyrec motor that weighed a ton....like don't pick it up by yourself. And it sat on the floor below the lathe with a driveshaft. The SP02 was a latter aftermarket development (JVC made a drive as well).

When I sold my VMS70 I had a spare motor and platter...a broker bought it to sell to clients in Korea...

microstrip · Jun 24, 2018

tima said:
Hi Morricab - it may be semantics ... I'm not sure. The GPA Web site indicates: "The proprietary slotless motor has an infinite pole design with a custom controller using 74,000 line encoder disc..."

Whenever I've talked with Alvin Lloyd about the new drive system he refers to the motor as a "slotless motor." I've not heard him use the term "coreless."

My 2.0 review had to pass the normal manufacturer's technical accuracy assesment: "Lloyd replaced the brushless 12-pole DC motor of the 1.5 with a custom-made slotless motor. Slotless motor designs place only copper phase coils in the air gap of the motor; the discontinuous iron teeth found in a slotted motor design (those used in most direct-drive ‘tables) are gone. This virtually eliminates cogging or cogging torque -- the bane of turntable motors. Torque becomes a function of the applied phase current, and current gets into the windings very fast. This means much smoother motion with greater torque linearity than a traditional slotted design, and much less vibration and noise."

My understanding of a coreless motor is one without an iron core that normally holds the coil. I read slotless motor manufacturer's also refer to their product as ironless. I'm not a motor design guru, but my sense is that "slotless" and "coreless" may not be distinct designs and here the words are used interchangeably, but I'm willing to be educated.

It is explained in theoretical books about electrical motors - once they are optimally powered by modern electronics motors can become cog free and have uniform torque. You only feel the teeth when the motor is not powered - then the magnetic field is created only by the induction of the permanent magnetic rotor and is discontinuous. As soon as you power the motor, the magnetic field created by the several windings can create an constant torque and you do not feel cogging anymore.

Another issue is correcting the speed changes due to stylus drag, a much more complex and questionable subject.

tima said:
(...) Torque becomes a function of the applied phase current, and current gets into the windings very fast. This means much smoother motion with greater torque linearity than a traditional slotted design, and much less vibration and noise.[/I]"

This dubious sentence, intended to be simple to understand by children and audiophiles, is meaningless in a motor that turns at less than one turn per second, unless properly explained and documented.

But yes, I am prepared to accept that because of many other reasons, much harder to explain technically, the slotless version sounds better - this is an hobby of preferences, most of which we can not explain scientifically. In the end, most of the time it is the implementation that counts.

microstrip · Jun 24, 2018

Solypsa said:
Actually they used a cored lyrec motor that weighed a ton....like don't pick it up by yourself. And it sat on the floor below the lathe with a driveshaft. The SP02 was a latter aftermarket development (JVC made a drive as well).

When I sold my VMS70 I had a spare motor and platter...a broker bought it to sell to clients in Korea...

Thanks for correcting - I knew about it, I remember you already had told about it. I could have been more clear.

The Lyrec was really slotted!

https://www.youtube.com/watch?v=-uicyBjfvEQ

morricab · Jun 25, 2018

microstrip said:
IMHO this a dogmatic view on turntables, ignoring the complexity of a turntable and the capabilities of electronics.

What is considered one of the best sounding drive system in the world, the Neumann VMS 66/70 Vinyl Cutting Lathe uses a cored Technics SP-02 direct drive motor.

If a turntable would suffer from issues due to the cores they would show clearly in the wow and flutter measurement spectra - FFTs are very powerful tool and would easily detect a peak that would have a frequency that is a multiple of the rotation speed times the number of poles.

BTW, turntables can not be compared with the most usual motor applications, where efficiency and torque maximization are key issues. No one in high end cares about it.

All IMHO, YMMV.

This was the view of the entire Japanese DD industry, with the exception (at the time) of Technics and Denon. Now, even Technics has gone coreless in their new models. Kenwood, JVC, Yamaha, Sony, Pioneer, Sansui etc. all went coreless because of the obvious sonic advantages. Where they still skimped in many cases was the plinth, which were often cheap and light. Put the drive system in a solid plinth and then you have a world class TT if you give it a good arm.

You cannot compare a cutting lathe to a playback system. The forces while cutting a record are much higher than on playback and so a beastly high torque motor was probably required...but I would bet that replacing that motor with a coreless one of similar torque would work even better. You have to realize the revolution to coreless was a late 70s phenomenon, which I would guess the Neumann is older, no? To the best of my knowledge you cannot use a cutter for playback, so why would you call it the best sounding drive system? That is somewhat nonsensical.

It does show...but who is looking today? But most importantly, it shows sonically. Specs are always averages...never shows there.

Well, the coreless motors have significantly LESS torque for a given size due to the lack of iron in the stator, which strengthens the magnetic field. Smoothness matters much more for a TT motor and the coreless motors are the kings of this.

morricab · Jun 25, 2018

tima said:
Hi Morricab - it may be semantics ... I'm not sure. The GPA Web site indicates: "The proprietary slotless motor has an infinite pole design with a custom controller using 74,000 line encoder disc..."

Whenever I've talked with Alvin Lloyd about the new drive system he refers to the motor as a "slotless motor." I've not heard him use the term "coreless."

My 2.0 review had to pass the normal manufacturer's technical accuracy assesment: "Lloyd replaced the brushless 12-pole DC motor of the 1.5 with a custom-made slotless motor. Slotless motor designs place only copper phase coils in the air gap of the motor; the discontinuous iron teeth found in a slotted motor design (those used in most direct-drive ‘tables) are gone. This virtually eliminates cogging or cogging torque -- the bane of turntable motors. Torque becomes a function of the applied phase current, and current gets into the windings very fast. This means much smoother motion with greater torque linearity than a traditional slotted design, and much less vibration and noise."

My understanding of a coreless motor is one without an iron core that normally holds the coil. I read slotless motor manufacturer's also refer to their product as ironless. I'm not a motor design guru, but my sense is that "slotless" and "coreless" may not be distinct designs and here the words are used interchangeably, but I'm willing to be educated.

Slotless is normally referring to a motor with brushes (direct commutation) and a slot is where the brush makes electrical contact. A good example of a slotted motor was the TEAC motor from the TN400 early 70s TT.

http://www.vintagehificlub.com/quick-informations/teac-tn-400-giradischi/

It has an iron core but each of the diagonal windings is a slot that the brush makes and breaks contact with.

i have seen recently though some people using "slotless" and "coreless" to mean the lack of iron core and using only copper coils. This was traditionally called coreless. If it is using only copper coils and no iron then it is indeed coreless and likely a big improvement over the brushless (but cored) motor from before. What I heard at Munich suggested very good sound from this TT.

Examples of coreless motors

https://www.vinylengine.com/turntable_forum/gallery/image_page.php?album_id=106&image_id=29851
https://m.review33.com/forum_msg.php?db=1&topic=19120115115734
http://audio-database.com/PIONEER-EXCLUSIVE/player/pl-50lii-e.html
https://www.audioasylum.com/cgi/vt.mpl?f=vinyl&m=902191

Brinkmann now makes one like this as well...even for their belt drive (Sinus motor).

Now there are also coreless designs that aren't pancake designs but I think these are usually brushed models (ie. they have "slots"). Maybe this is what Grand Prix uses? This is a very viable option and would likely generate more torque (although Brinkmann clearly thinks high torque is bad...as does a company called Primary Control from Netherlands).

There is confusion about cogging and torque when the motor is active. Torque ripple is what must be minimized and this is not inherently eliminated when iron is removed but it is lessened significantly. The least ripple from a motor is actually a slotted (ie. with brushes) and coreless if there are 150 or so slots. These motors were designed for the computer tape industry originally but are very smooth and at low speeds quiet enough (brushes make a lot of noise at high speed).

This is why clear definitions are necessary. I read slotless on the Grand Prix website to mean "brushless" but they meant "coreless" it seems.

morricab · Jun 25, 2018

microstrip said:
It is explained in theoretical books about electrical motors - once they are optimally powered by modern electronics motors can become cog free and have uniform torque. You only feel the teeth when the motor is not powered - then the magnetic field is created only by the induction of the permanent magnetic rotor and is discontinuous. As soon as you power the motor, the magnetic field created by the several windings can create an constant torque and you do not feel cogging anymore.

Another issue is correcting the speed changes due to stylus drag, a much more complex and questionable subject.

This dubious sentence, intended to be simple to understand by children and audiophiles, is meaningless in a motor that turns at less than one turn per second, unless properly explained and documented.

But yes, I am prepared to accept that because of many other reasons, much harder to explain technically, the slotless version sounds better - this is an hobby of preferences, most of which we can not explain scientifically. In the end, most of the time it is the implementation that counts.

Torque ripple on a cored motor cannot be eliminated with electronic commutation. The torque is not constant.

microstrip · Jun 25, 2018

morricab said:
Torque ripple on a cored motor cannot be eliminated with electronic commutation. The torque is not constant.

There are many books and IEEE articles explaining how to eliminate it - it is a very researched subject.

See for example "Permanent Magnet Synchronous and Brushless DC Motor Drives" by Ramu Krishnan, CRC books 2017.

As I referred, the implementation problems became critical at high speed - speeds much over 3000 RPM, the typical applications of coreless motors. 33.33 RPM is a simple affair, even before high speed DSP. You will not find published research for such low speed, it is not challenging.

bonzo75 · Jun 25, 2018

Solypsa said:
Actually they used a cored lyrec motor that weighed a ton....like don't pick it up by yourself. And it sat on the floor below the lathe with a driveshaft. The SP02 was a latter aftermarket development (JVC made a drive as well).

When I sold my VMS70 I had a spare motor and platter...a broker bought it to sell to clients in Korea...

Is this the same as the ortofon lyrec? Recently heard some vinyl recorded on it which were fabulous.

DaveyF · Jun 25, 2018

At a recent Technics event that I attended, where they introduced their new table, which apparently is now immune to the 'cogging' effect; the rep stated that even today, they don't really believe that cogging was ever audible. The rep went on to say that it was an a'phile thing that was used by their competitors at the time to give them a leg up ( since none of them were developing the dd system). Nonetheless, their new motor cannot introduce this issue.

Solypsa · Jun 25, 2018

bonzo75 said:
Is this the same as the ortofon lyrec? Recently heard some vinyl recorded on it which were fabulous.

The Ortofon system was different altogether...the Ortofon cutterhead, while quite delicate, is highly regarded. The Neumann SX74 cutterhead could handle higher levels...

This record label / studio site offers some nice visuals to compare the various lathes
( http://www.organicmusic.de )

OP: sorry for taking this OT. Carry on!

morricab · Jun 25, 2018

DaveyF said:
At a recent Technics event that I attended, where they introduced their new table, which apparently is now immune to the 'cogging' effect; the rep stated that even today, they don't really believe that cogging was ever audible. The rep went on to say that it was an a'phile thing that was used by their competitors at the time to give them a leg up ( since none of them were developing the dd system). Nonetheless, their new motor cannot introduce this issue.

Whether it was clogging or torque ripple from having a cited motor, IME, they sound not as smooth and drier than coreless designs I have heard.

tima · Jun 26, 2018

morricab said:
Slotless is normally referring to a motor with brushes (direct commutation) and a slot is where the brush makes electrical contact. A good example of a slotted motor was the TEAC motor from the TN400 early 70s TT.

http://www.vintagehificlub.com/quick-informations/teac-tn-400-giradischi/

It has an iron core but each of the diagonal windings is a slot that the brush makes and breaks contact with.

i have seen recently though some people using "slotless" and "coreless" to mean the lack of iron core and using only copper coils. This was traditionally called coreless. If it is using only copper coils and no iron then it is indeed coreless and likely a big improvement over the brushless (but cored) motor from before. What I heard at Munich suggested very good sound from this TT.

Examples of coreless motors

https://www.vinylengine.com/turntable_forum/gallery/image_page.php?album_id=106&image_id=29851
https://m.review33.com/forum_msg.php?db=1&topic=19120115115734
http://audio-database.com/PIONEER-EXCLUSIVE/player/pl-50lii-e.html
https://www.audioasylum.com/cgi/vt.mpl?f=vinyl&m=902191

Brinkmann now makes one like this as well...even for their belt drive (Sinus motor).

Now there are also coreless designs that aren't pancake designs but I think these are usually brushed models (ie. they have "slots"). Maybe this is what Grand Prix uses? This is a very viable option and would likely generate more torque (although Brinkmann clearly thinks high torque is bad...as does a company called Primary Control from Netherlands).

There is confusion about cogging and torque when the motor is active. Torque ripple is what must be minimized and this is not inherently eliminated when iron is removed but it is lessened significantly. The least ripple from a motor is actually a slotted (ie. with brushes) and coreless if there are 150 or so slots. These motors were designed for the computer tape industry originally but are very smooth and at low speeds quiet enough (brushes make a lot of noise at high speed).

This is why clear definitions are necessary. I read slotless on the Grand Prix website to mean "brushless" but they meant "coreless" it seems.

This is helpful - thanks for taking your time to go through it. Fwiw, the motor used in the previous version 1.5 was a brushless 12-pole DC design and adapted from one used in the automated manufacture of IC circuit boards. For now and apart from mesaurement specs, GPA is mostly mum on actual drive system components and implementation details for the v2.0; its motor is custom built for its role in the 'table. I'll speculate that if you asked GPA, they'd say the real key to the motor's performance is in its controller software.

morricab · Jun 26, 2018

tima said:
This is helpful - thanks for taking your time to go through it. Fwiw, the motor used in the previous version 1.5 was a brushless 12-pole DC design and adapted from one used in the automated manufacture of IC circuit boards. For now and apart from mesaurement specs, GPA is mostly mum on actual drive system components and implementation details for the v2.0; its motor is custom built for its role in the 'table. I'll speculate that if you asked GPA, they'd say the real key to the motor's performance is in its controller software.

Don't get me wrong, I totally do not underestimate the importance of the speed control architecture. Motors of this type will not be speed stable under load without it. This was a second revolution (no pun intended) in the late 70s, early 80s. The big Japanese companies came up with far better control systems on their later decks (to go with the better motors) that all but eliminated the over/undershoot issues that have been attributed to DD control systems. JVC famously (and probably most successfully) came up with a double bi-directional servo that was also used in the Yamaha GT-2000 series TTs (Yamaha also used one of JVCs 4 pole coreless motors AND a 6kg platter for even smoother operation). Kenwood for the L07-D (and probably later coreless motored DDs like the KP-990 and KP-9010) had a very sophisticated double nested PLL design that was relatively "soft" and also had a 5 or 6Kg platter for inertia.

The Grand Prix is using a sophisticated optical encoder and software that is checking supposedly 300K per revolution. Beyond that I don't know what is being done, if anything additional. There is likely some algorithm that decides when the platter speed is outside of a window and requires a corrective push. The question is does that circuit also "pull"? Most servos only will push when the speed is too low. If it is too fast then it cannot act. So, undershoot is corrected actively but overshoot is corrected passively (i.e. it waits for the platter to naturally slow down). The question about the alogrithm of the Grand Prix is how tight is the regulation and is it in both directions or only one? Is it designed to allow soft speed adjustments rather than abrupt ones?

I know from some experience working with this type of motor and controller that the corrections can be made very abruptly if the motor has sufficient torque/platter mass and this would likely be pretty audible and detrimental to the sound quality.

I heard the GP 2.0 in Munich on the huge Living Voice system and that was a very good sounding demo. The comments and reviews about the earlier generations sounds like the comments one would hear about the early days direct drives from Japan and/or the cheap DJ tables. Punchy but dry and lacking the correct harmonic content. I can tell you that the Japanese solved this problem by the early 80s but not many were listening to them by then (outside of Japan that is). From what I heard of the 2.0, it sounds like GPA solved this now as well in this version. I bet that change of motor is far more significant than maybe you realize for just this kind of reason.

morricab · Jun 26, 2018

DaveyF said:
At a recent Technics event that I attended, where they introduced their new table, which apparently is now immune to the 'cogging' effect; the rep stated that even today, they don't really believe that cogging was ever audible. The rep went on to say that it was an a'phile thing that was used by their competitors at the time to give them a leg up ( since none of them were developing the dd system). Nonetheless, their new motor cannot introduce this issue.

Also, I bet their engineers, who spent a lot of time developing a new motor, would not be so inclined to say it makes no difference and is only a marketing tool...

microstrip · Jun 26, 2018

tima said:
This is helpful - thanks for taking your time to go through it. Fwiw, the motor used in the previous version 1.5 was a brushless 12-pole DC design and adapted from one used in the automated manufacture of IC circuit boards. For now and apart from mesaurement specs, GPA is mostly mum on actual drive system components and implementation details for the v2.0; its motor is custom built for its role in the 'table. I'll speculate that if you asked GPA, they'd say the real key to the motor's performance is in its controller software.

Yes, and as far as I remember no one complained that he was able to listen to "torque ripple effects" in the older design.

Unfortunately many times people listen with their eyes - it is why many times manufacturers hide technical details, avoiding audiophile stereotypes. Did you read in this forum anyone complaining that Mike NVS turntable suffers from "torque ripple effects"? Why does Kodo refer to its excellent DD motor as "three phase motor driven by a very sophisticated controller" (most brushless motors fall under this umbrella)?

IMHO the fundamental aspects of sound quality rely on the implementation. GPA seem to be masters in the control software. This extreme expertise makes generalization to inferior products almost impossible. And we should not mix our preference with performance. Just MHO, YMMV.

tima · Jun 26, 2018

microstrip said:
Yes, and as far as I remember no one complained that he was able to listen to "torque ripple effects" in the older design.

Unfortunately many times people listen with their eyes - it is why many times manufacturers hide technical details, avoiding audiophile stereotypes. Did you read in this forum anyone complaining that Mike NVS turntable suffers from "torque ripple effects"? Why does Kodo refer to its excellent DD motor as "three phase motor driven by a very sophisticated controller" (most brushless motors fall under this umbrella)?

IMHO the fundamental aspects of sound quality rely on the implementation. GPA seem to be masters in the control software. This extreme expertise makes generalization to inferior products almost impossible. And we should not mix our preference with performance. Just MHO, YMMV.

Yes - very good observations. It is both surprising and not surprising how many manufacturers are reluctant to expose technical details. Obviously some rightly fear design adoption (intellectual property theft) though there are as many who believe review readers have (or should have) little interest in what's under the covers. There's probably some truth there. Some readers only care if the thing will improve their system's sonics, provides ownership satisfaction, looks good (listening with their eyes as you say) and to some extent is accepted by their peers or yields status. As a writer I feel compelled to deliver more than marketing literature in describing what the thing is and how and/or why it works the way it does. (Call that my problem.) Sometimes it is a struggle and there are trade-offs. Smaller manufacturers along with those covered in patents are usually more open though the former are more fearful of losing their ideas, whereas large manufacturers who are well established or believe their reputation secure can be very close-mouthed about what's under the hood, beyond repeating what's in their marketing literature. It's their right to reveal what they will and I'm laying nothing at anyone's doorstep. I say listen for yourself. Coming out of the hyper-competitive, cut-throat, big-dollar world of auto racing, GPA is willing to publish performance specs but they will only go so far, saying their published numbers "as is normal practice for engineers" have a significant "safety factor" built in to ensure no unit long term will ever fall outside their claims.

morricab · Jun 26, 2018

microstrip said:
Yes, and as far as I remember no one complained that he was able to listen to "torque ripple effects" in the older design.

Unfortunately many times people listen with their eyes - it is why many times manufacturers hide technical details, avoiding audiophile stereotypes. Did you read in this forum anyone complaining that Mike NVS turntable suffers from "torque ripple effects"? Why does Kodo refer to its excellent DD motor as "three phase motor driven by a very sophisticated controller" (most brushless motors fall under this umbrella)?

IMHO the fundamental aspects of sound quality rely on the implementation. GPA seem to be masters in the control software. This extreme expertise makes generalization to inferior products almost impossible. And we should not mix our preference with performance. Just MHO, YMMV.

Well, the original was not that well received by Fremer at least. Our own Ked heard the 1.5 (or original) and was also not impressed. Not sure how you hear a motor buried in the chassis "with your eyes". As, I said, it was never clear whether GPA was using a cored or coreless motor but it seems that a motor upgrade in V2.0 did indeed go to a coreless design. I hear a problem with all of the Technics tables from the past (note: I haven't heard the SP10Mk3 but the earlier ones).

Also, how do you know the Kodo has an excellent motor? Have you heard that TT? From the description it is like you said but that also means it is likely not coreless. We will have to speculate on how that would sound...I would argue it would sound better if they too went coreless.

The mighty Caliburn, even though it was belt drive, was also using a coreless motor, according to the manufacturer (I talked with him many years ago in Munich). The latest Continuum uses a BRUSHED DC coreless motor...most interesting choice...

"The Caliburn uses a patented motor coil technology similar in principle to a voice coil.
By working with the underlying technology we reduced the mechanical and RF noise to a minimum resulting in a super quiet motor which does not pulse or cog.
Housed in a solid block of damped alloy with precision-engineered bearings the motor delivers new benchmark levels of performance and motion control.
When compared to the most expensive turntable motors the “true zero cogging” technology we employed delivers superior audio results."

You can get similar motors that are printed armature motors, which are pancakes, but don't have to be as the Continuum one is not.

Interestingly, this is exactly what Brinkmann has now done with their belt drive motor, the Sinus. It is a spinoff of their DD Oasis and Bardo and they realized clear gains even with belt-drive going coreless.

Last, but not least, Nakamichi went to direct drive with their cassette decks, the Dragon and ZX-9, using advanced coreless designs because they sounded better (they are still revered to this day). My colleague has a ZX-9 and I can tell you that is one awesome cassette deck...rivals pretty good R2R tape sound (He has a good one of those too).

I think the TT engineering world in the west largely ignored these lessens and their return to DD still has a taint that the motor itself is less important than the control circuits...but it isn't and now GPA seems to get that with V2.0. I have seen 20K+ belt drives with simple AC synchronous motors and a synthesized AC power, if you are lucky...tragic really and you can hear it sonically.

You can believe what you want about the importance of the motor technology, I am not fooled and it seems the serious designers have realized what the Japanese figured out nearly 40 years ago. It matters...a lot and those on this forum considering DD, or even a belt drive should look very critically at the motor type being implemented before laying down their hard earned money. A fancy control system will not solve all issues with a motor that are inherent in the motor design...just like negative feedback won't fix what is inherently wrong in an amp design...things have to be solved on a fundamental level not cleaned up later downstream.

microstrip · Jun 26, 2018

morricab said:
Well, the original was not that well received by Fremer at least. Our own Ked heard the 1.5 (or original) and was also not impressed. Not sure how you hear a motor buried in the chassis "with your eyes". As, I said, it was never clear whether GPA was using a cored or coreless motor but it seems that a motor upgrade in V2.0 did indeed go to a coreless design. I hear a problem with all of the Technics tables from the past (note: I haven't heard the SP10Mk3 but the earlier ones).

Also, how do you know the Kodo has an excellent motor? Have you heard that TT? From the description it is like you said but that also means it is likely not coreless. We will have to speculate on how that would sound...I would argue it would sound better if they too went coreless.

The mighty Caliburn, even though it was belt drive, was also using a coreless motor, according to the manufacturer (I talked with him many years ago in Munich). The latest Continuum uses a BRUSHED DC coreless motor...most interesting choice...

"The Caliburn uses a patented motor coil technology similar in principle to a voice coil.
By working with the underlying technology we reduced the mechanical and RF noise to a minimum resulting in a super quiet motor which does not pulse or cog.
Housed in a solid block of damped alloy with precision-engineered bearings the motor delivers new benchmark levels of performance and motion control.
When compared to the most expensive turntable motors the “true zero cogging” technology we employed delivers superior audio results."

You can get similar motors that are printed armature motors, which are pancakes, but don't have to be as the Continuum one is not.

Interestingly, this is exactly what Brinkmann has now done with their belt drive motor, the Sinus. It is a spinoff of their DD Oasis and Bardo and they realized clear gains even with belt-drive going coreless.

Last, but not least, Nakamichi went to direct drive with their cassette decks, the Dragon and ZX-9, using advanced coreless designs because they sounded better (they are still revered to this day). My colleague has a ZX-9 and I can tell you that is one awesome cassette deck...rivals pretty good R2R tape sound (He has a good one of those too).

I think the TT engineering world in the west largely ignored these lessens and their return to DD still has a taint that the motor itself is less important than the control circuits...but it isn't and now GPA seems to get that with V2.0. I have seen 20K+ belt drives with simple AC synchronous motors and a synthesized AC power, if you are lucky...tragic really and you can hear it sonically.

You can believe what you want about the importance of the motor technology, I am not fooled and it seems the serious designers have realized what the Japanese figured out nearly 40 years ago. It matters...a lot and those on this forum considering DD, or even a belt drive should look very critically at the motor type being implemented before laying down their hard earned money. A fancy control system will not solve all issues with a motor that are inherent in the motor design...just like negative feedback won't fix what is inherently wrong in an amp design...things have to be solved on a fundamental level not cleaned up later downstream.

Adding more opinions from manufactures who endorse and use coreless motors over or picking isolated reviewer opinions does not add nothing to this issue ... IMHO there are so many variables in turntable design and so many varieties that generalizations are not possible, and even then they are due to preferences. We have to look at the whole package before taking a decision.

Are you telling us we should not own, for example, a Micro Seiki 8000 because the motor is not coreless?

BTW, I also own a few top coreless cassette decks- two Nakamichi CR7 and one Revox B215 - a few weeks ago I have been cleaning, checking and listening to them, as I am considering reducing the collection.

Sorry, but no comparison is possible with the ultra heavy cored synchronous motor Studer A80 ... But yes, they are really enjoyable!

Review: Grand Prix Audio • Monaco 2.0 Turntable

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