Primary Control Kinea turntable

[marmota]

Hi!

I've tried to make this questions in another thread, but since there was no answer, I decided to open a thread about this gorgeus turntable.
Copy/paste:
https://www.whatsbestforum.com/thre...log-lines-to-the-usa.22825/page-3#post-583229

"The Kinea turntable looks lovely, I'm unable to afford to buy one at the moment, but I would like to make a couple of questions, just out of curiosity:

- Does it feature a servo for speed regulation? The Brinkmann direct drive turntables, while being low torque, use (a very small amount) of speed regulation, the only turntables I know of that are direct drive but do not use servos or speed regulation of any kind are the Kodo the Beat (40k with tonearm, ouch!) and the Teres Certus (discontinued).

- Is the record mat an integral part that plays "with a special synergy" on the turntable, or can it be changed for another one? To be honest, at least in pictures, looks a bit ugly, not in line with the sophisticated, really well thought out turntable IMHO.

The last one is just a suggestion, but they should put the PSU/speed controller in a nicer, CNC milled box, even if it raises the price 500-1000$, the box looks like something anyone could buy at Modushop or Audiophonics, it doesn't do justice to the beauty of the turntable, again IMHO. "

Just to add something, I've tried to google-fu about this gem but there's very, very little info about it on the web, just a couple of threads here, some show reports and some words on Vinyl Savor, but nothing in depth about the design.
Again, sorry if I come across as somewhat impatient/too curious, hope y'all have a nice week!

 

[ddk]

Hi!

I've tried to make this questions in another thread, but since there was no answer, I decided to open a thread about this gorgeus turntable.
Copy/paste:
https://www.whatsbestforum.com/thre...log-lines-to-the-usa.22825/page-3#post-583229

"The Kinea turntable looks lovely, I'm unable to afford to buy one at the moment, but I would like to make a couple of questions, just out of curiosity:

- Does it feature a servo for speed regulation? The Brinkmann direct drive turntables, while being low torque, use (a very small amount) of speed regulation, the only turntables I know of that are direct drive but do not use servos or speed regulation of any kind are the Kodo the Beat (40k with tonearm, ouch!) and the Teres Certus (discontinued).

- Is the record mat an integral part that plays "with a special synergy" on the turntable, or can it be changed for another one? To be honest, at least in pictures, looks a bit ugly, not in line with the sophisticated, really well thought out turntable IMHO.

The last one is just a suggestion, but they should put the PSU/speed controller in a nicer, CNC milled box, even if it raises the price 500-1000$, the box looks like something anyone could buy at Modushop or Audiophonics, it doesn't do justice to the beauty of the turntable, again IMHO. "

Just to add something, I've tried to google-fu about this gem but there's very, very little info about it on the web, just a couple of threads here, some show reports and some words on Vinyl Savor, but nothing in depth about the design.
Again, sorry if I come across as somewhat impatient/too curious, hope y'all have a nice week!

You can't have a dc motor without a controller so all direct drives with dc motors are controlled by a driver via some sort of feedback loop or servo controller. Like there's no such thing as a little pregnant there's no such thing as little or a lot of adjustment, there's always constant adjustment with dc motors.

You can always experiment with different mats!

david

 

[microstrip]

You can't have a dc motor without a controller so all direct drives with dc motors are controlled by a driver via some sort of feedback loop or servo controller. Like there's no such thing as a little pregnant there's no such thing as little or a lot of adjustment, there's always constant adjustment with dc motors.

You can always experiment with different mats!

david

We can use most DC motors without feedback or servo - just supplying them with three sinusoidal phases as people do with synchronous drives. I did it long ago with good results in an Oracle III, that used a brushless DC motor. The amplitude of the waveform should be adjusted for optimal drive and minimum noise.

 

[ddk]

We can use most DC motors without feedback or servo - just supplying them with three sinusoidal phases as people do with synchronous drives. I did it long ago with good results in an Oracle III, that used a brushless DC motor. The amplitude of the waveform should be adjusted for optimal drive and minimum noise.

I've never come across that in any commercial application with direct drive turntables. IME the problem with a dc motor is that it only knows where it's been but you have to tell it where to go and how fast.

Edit- I'm not saying that it can't be done but who's doing it that way?

david

 

[microstrip]

I've never come across that in any commercial application with direct drive turntables. IME the problem with a dc motor is that it only knows where it's been but you have to tell it where to go and how fast.

Edit- I'm not saying that it can't be done but who's doing it that way?

david

I can't remember the brand now, but Papst supplies the motors and controllers separately and a turntable manufacturer was buying just the motor and using it as a synchronous motor.

 

[ddk]

I can't remember the brand now, but Papst supplies the motors and controllers separately and a turntable manufacturer was buying just the motor and using it as a synchronous motor.

DD turntable without servo or feedback loop?

david

 

[tima]

IME the problem with a dc motor is that it only knows where it's been but you have to tell it where to go and how fast.

If the controller interface is fast enough the controller can know w/in microseconds where the platter is/was w/in microseconds (or less?). If the increment of measurement is very tiny, or the reads are very many within a given distance, the interface (and any adjustment) can come awfully close to 'real time.' If it's where it should be it keeps doing what it did to get there. If the number of adjustments (which the controller can know) is very small for a given distance the results can be favorable versus other types of motor or controller systems. I suspect the quality of the dc motor in terms of its reaction time - say the controller increases output voltage by a tenth a millimeter - is important.

edit: I'm not saying one technology is superior to another, just different ways to skin a cat.

 

[spiritofmusic]

David, I'm suprised in addition to yr advice on experimenting w mats you didn't say try different pwr cords to the tt motor.

Every little counts LOL.

 

[ddk]

If the controller interface is fast enough the controller can know w/in microseconds where the platter is/was w/in microseconds (or less?). If the increment of measurement is very tiny, or the reads are very many within a given distance, the interface (and any adjustment) can come awfully close to 'real time.' If it's where it should be it keeps doing what it did to get there. If the number of adjustments (which the controller can know) is very small for a given distance the results can be favorable versus other types of motor or controller systems. I suspect the quality of the dc motor in terms of its reaction time - say the controller increases output voltage by a tenth a millimeter - is important.

edit: I'm not saying one technology is superior to another, just different ways to skin a cat.

We’re not comparing technologies here just discussing direct drives and dc motors. I guess (because I haven’t verified if it’s true) faster reaction time ameliorates the problem but not eliminate it and depending on the number of adjustments per 3-6 revolutions those milliseconds add up quick.

david

 

[ddk]

David, I'm suprised in addition to yr advice on experimenting w mats you didn't say try different pwr cords to the tt motor.

Every little counts LOL.

That discovery is all yours Marc!

david

 

[microstrip]

DD turntable without servo or feedback loop?

david

No, belt driven DD motor turntable without servo or feedback loop.

But some DD turntables allowed you to disconnect the servo loop - at the price of not being .001% accurate.

 

[Lagonda]

David, I'm suprised in addition to yr advice on experimenting w mats you didn't say try different pwr cords to the tt motor.

Every little counts LOL.

Did you get your RoadRunner Marc ?

 

[spiritofmusic]

Milan, I'm considering it. Tbh my strobe disc is pretty good, other than pure curiosity I'm not sure how much more I would get going Roadrunner. Its on the "maybe" list of priorities. Thanks for the heads up on it.

 

[Lagonda]

Let me know how precise your speed
is, and how much variation on needle drop. If you end up doing it of course.
I’m just curious in general

 

[spiritofmusic]

Sure Milan, I'm v tempted. I know my direct rim drive/zero feedback loop tt is not the most accurate for speed precision, having some drift that needs adjustment every few days. It would be illuminating to see this in numerical terms.

Usual argument about absolute speed stability v average stability over time.

 

[marmota]

Wow, so many replies! Thank you very much!

@ddk Apparently, there're DD turntables without a servo or speed correction, such as Kodo the Beat or Teres Certus, but both use AC motors.
I didn't know that DC motors made that impossible, is nice to learn!

 

[Tango]

Sure Milan, I'm v tempted. I know my direct rim drive/zero feedback loop tt is not the most accurate for speed precision, having some drift that needs adjustment every few days. It would be illuminating to see this in numerical terms.

Usual argument about absolute speed stability v average stability over time.

Adjust speed every few days will keep you do foot work watching out for jabs like Muhammad Ali Marc.

 

[spiritofmusic]

Tang, I need that fancy footwork to argue my cause on WBF. Setting up a tt is dead easy compared to jousting here over the years.

 

[microstrip]

Wow, so many replies! Thank you very much!

@ddk Apparently, there're DD turntables without a servo or speed correction, such as Kodo the Beat or Teres Certus, but both use AC motors.
I didn't know that DC motors made that impossible, is nice to learn!

There is some confusion here. A brushless DC motor is just an AC motor, the AC waveforms are generated from the DC. As far as I could see the Kodo uses just the type of motor I described in post #3 https://www.whatsbestforum.com/threads/primary-control-kinea-turntable.28446/post-584736

We generally call AC motors those that are supposed to be connected directly to mains, commonly using a phasing capacitor.

The technical facts are extremely simple, manufacturer literature can make it confusing.

 

[ddk]

Wow, so many replies! Thank you very much!

@ddk Apparently, there're DD turntables without a servo or speed correction, such as Kodo the Beat or Teres Certus, but both use AC motors.
I didn't know that DC motors made that impossible, is nice to learn!

I didn't realize that Kodo the Beat used an AC motor, I learnt something too !

david