2020 update : JC Verdier La Platine


A recent encounter with a JC Verdier dealer as well as a recent Audiogon discussion thread led to the start of this thread. He was in my house updating my La Platine which had been in storage for ten years with thread and oil. While he has high regards for the deck, his newer clients nevertheless prefer a Techdas iii than an 'old' La Platine. Given the proliferation of expensive decks in the past dozen years, La Platine has become very much under-appreciated. 

It's clear to me that the influence of the La Platine is everywhere to be found. Specifically, the magnetic suspension system that was employed 30+ years ago. Even SOTA offers their newer decks with mag. lev. features. And if you read this review: https://www.callas-audio.nl/Callas%20Platine%20Mod%20Kit%20Review.pdf, the Continuum Caliburn uses the same concept, which was not acknowledged in Fremer's review, albeit with more sophisticated , and expensive, execution.

It is also clear to me that there is much misunderstanding of the workings of the La Platine. I for one have contributed to this. The motor of the La Platine, for example, has been much maligned. The thread drive is another aspect of the turntable that have been described as inferior. With regard to the motor and thread drive, I have been set straight by Chris @ct0517 and Lyubomir @lbelchev. Experimenting with the different types of silk threads, the tightness to the platter  and a renewed understanding of the soundness of the Philips motor have been rewarded with better dynamics and transparency. 

The funny thing is that during the past two years of re-engagement with audio, I have questioned ownership of every components in my arsenal except the La Platine. It has always been a keeper. I wonder if La Platine owners would contribute to celebrating this 'old' deck with tales, advice, and insights?

Cheers!
ledoux1238

@dover Thanks for that tip, written by a true veteran. It took me until yesterday to try it out. I cannot hear a definite improvement, but certainly didn’t hurt.

I know you have moved on from the Verdier, but I am still continually intrigued so I muddle along quite happily.

@ledoux1238 

Been there, done that, It will sound a lot better again if you use 3 feet only.

I experimented with defeating the suspension of the Verdier using macassar ebony footers. These foorters were sourced locally, 2.5 cm dia. x 5 cm tall. They rest on a 1 cm dia. crystal ball and ebony cup. I use a total of six, four at each corner and two near the spindle. 

The result sonically is a blacker background, better clarity and smoothness on both ends of the frequencies, and more stable imaging with the soundstage. The width and depth of the soundstage seems unaffected. 

I have read in this forum thread from folks who advocate keeping the suspension intact, even for the black MDF plinth version which I own. However, re-reading information on motor control by Thom @thom_at_galibier_design , it seemed to make sense. He is an advocate of tight coupling of motor and platter. And it turns out in my case, I do hear improvement in sound quality. And this is a first step in the road to maybe improving the motor aligning myself with advocates of non-suspended plinth. 

I also use an air bearing linear tracking tonearm and often wondered might it not work better on a non-suspended plinth. Again, there are folks who use ET arms on the Verdier although most LT arms, that I know of, are used on the concrete polymer plinth. In any case, I am happy to report that this sound improving tweak  is working for me. YMMV

No worries,

Its from Vietnam both motor and controller.

The seller ended up sending me a unit that would not power up. Firstly i asked for the Steel casing he sent me aluminum casing for the motor housing. I was already pissed of about that, second, the motor controller was not working i asked him to send me another one. im still waiting for the controller,

I dont recommend this seller at all, he took the funds really fast kept changing my order, spec and sent me stuff that does not work.

This is why i am not dare to talk about the motor or conroller on here.

@phantom_av Sorry to be a nuisance, but I was wondering if your Japanese motor experiment is bearing fruit? 

@ledoux1238 

i sure will .

I am also considering the Grand Prix parabolica table. A direct drive table .

another totally different direction of music reproduction.

the platine with the magnet my  audio friends are advising against because of the magnet .  They are sure the flux magnetic head on the atr with the mr70 head amps will pick it up for sure . So the decision is between nouvelle vs parabolica. 

I plan to demo them within a month and decide .

 

 

@newtoncr If you do venture into a Verdier, I would sincerely appreciate a follow-up from you. My friend has a SME 30/2 with various arms / cartridge changes, and  I could never get a handle of the differences between the two TT, too many variables. In addition, he has a much more resolved system than mine with Dartzeel and Magico in the loop. I have always been curious about the the true measure of the 30/2. The Lyra Etna Lambda SL is high on my list of the next step up. 

 

@ledoux1238 

thank you for your kind comments about my system . It has significantly changed since I posted the pictures . With couple of rtr decks . Will be updating the pictures and the components in my system .

I will defenitely try to compare the platine and nouvelle platine in his shop . That would give me a good idea.

I am upgrading my catridge in my sme from lyra etna lambda sl to lyra atlas lambda sl . Expecting a good improvement.

I am so hooked to analogue with my reel tape machine and vinyl that I think a second table will be an investment that I will be listening to every day .

will listen in my dealers shop and then go from there .

 

I have a SUT, 20cm, and a tube phono stage, 40 cm, behind the PV. This set up induces hum. However, I have always manage to reduce or eliminate it. I have copper wires connected to the grounding posts of the SUT, tube phono, and a second SS phono. And this has solved the problem. 

I do not know if the magnets of the PV are directly  responsible for the hum, though I suspect they probably are. But hum issues has been a solvable problem for me. 

@newtoncr Having looked at your beautiful listening room and your SME 30, I was initially uncertain why you would looked into owning the PV. But as a second TT it would make sense. If your dealer does not allow a home trail, would you be able to A/B the La Platine and the Nouvelle at his shop? The oil thrust bearing of the Nouvelle is carried into the TOTL Magnum Verdier, though in a much more sophisticated version. 

@dover 

Placing the system in a separate rack is not an option for me .the pics in my shrek page are old many things have changed now .

Turntable I use now is a sme 30/2 with a sme v tone arm and a lyra etna sl catridge.

the verdier will be my second table … looking for a more musical table . The sme and lyra are very accurate.

the magnet is making me nervous ,

Any thoughts on the nouvelle platine with the oils imersion platter would that be a better option for me .

my local dealer unfortunately does not allow a home trial .

@newtoncr 

I have a lot of tube gear - tubes themselves are a near perfect antenna.

I would be surprised if the magnetic platter caused noise - more likely to distort low level signals - if you could even hear it. You could put a metal plate (non magnetic)  under the TT and earth it to shield your RTR headlamp.

However other potential issues are turntable power supply and umbilical often generate hum/noise in sensitive electronics and also occasionally TT motors can also be a source. Switch mode supplies on TT's which are becoming more common can generate interference/hum.

Maybe you could set up the TT to the right/left of your existing system with a phono stage and just run a longer phono cable to your preamp.

 

@dover 

thank you for your response .

the table will be alongside the tape decks . The atr 102 and otari mtr 10. My head amp for the otari , doshi evo tape head amp will be underneath the table. I think that can be a problem cause the head preamps pick up everything . 
 

@newtoncr 

I had a Platine Verdier - the magnetic fields are vertical from memory and contained  - so as long as the RTR is off to the side ( not above or below ) there should be no issue.

Having said that I rebuilt a Garrard 301 which outperformed the Verdier significantly in pitch and timing ( with the same arm/cartridge ) - although the Verdier is very grainless in its presentation and can be musical with carefully selected arm/cartridge. I sold mine to an SME 20 owner and it outperformed that TT quite comfortably.

Hi,

I am thinking about purchasing the la platine table. My concern is it will be sitting next to a atr 102 reel deck with a mr70 head amp. Will the magnetic field from the platter cause noise in my tape deck . Does anyone have experience placing this next to sensitive electronics like a tape deck . Would the other version with the oil suspension be a better choice to me . 

thanks in advance 

The PTP Solid Nine > PTP Bearing > NSC > AudioMods Series V Micrometer is not my 'go to' TT any longer.

It has been extensively compared in my system on the same mounting structure and footers as my DD TT's are placed on.

I don't know if it is a age/hearing related influence, but I have moved on from the Idler to DD TT's as my go to TT. The DD TT is without doubt able to present a taut, clean Bass Note which is my preference. 

Recently I put a Panzerholz Sub Plinth Structure under a Garrard 401 and this had a very positive impact on the performance, the group who were receiving the demonstration of the TT, were quite impressed with the addition of the Sub Plinth and then the 1.4Kg Puck weight that was introduced, hence the weight being loaned to the SP10 R owner.   

@pindac since you are using a PTP Solid 9 which I also had. I suggest you replace the aluminum footers it comes with something simpler (steel cone) and also remove the O rings around the platter. These 2 "tweaks" by Peter damps the sound a lot

I am not sensitive to this correction method being referred to and as said, it is not a topic I have heard discussed at any time by known SP10 MkII and a SP10 R owner.

At the end of next week I am taking my PTP Solid Nine with Speed Controller to the System with the SP10 R, the idea is to allow the HiFi Group to assess a range of Platter Mats and Weights used on both TT's.

The added aside, is that I will be creating a Two Tier Sub Plinth using Panzerholz Platforms and AT-616 Footers as the Base and Intermediate Suspension.

I will be keen to see if any of this discussion about speed is detectable with a A/B comparison between the TT's.

I am also sure that when the Group Member produces their Kaneta Design SP10 MkII with a New Platter design, this will be compared to the owned EE Overhauled and Modified SP10 MkII and the SP10 R.

I will be quite keen to see if the correction speed correction referred to is detectable by myself.  

@pindac you are probably missing the point. We are not talking about speed fluctuation, we are talking about speed correction. Every TT has speed fluctuations and there are different correcting mechanisms. In direct drive like Technics the speed is corrected by a electronic circuit using a quartz lock. This correction happens many times a second at micro speed level in a DD. It is required because a DD motor rotates at only 33.3 rpm and the platter is part of the rotor which is rotating. Hence the error correction has to be very aggressive. Even a 0.5 rpm change is devastating while listening. But a BD and ID have motors rotating at 300rpm+. The platter rotates at 10th of the motor speed. Even if the motor speed changes by 1 rpm, the audible effect at the platter is much lower hence the error correction used is much more benign.

The continuous aggressive error correction is what gives DDs a certain character which people refer as discontinuous, fatiguing, analytical and so on. Not every one is sensitive to this character though hence if you do not hear, I envy you. IMO DD is the easiest way to get awesome honest and accurate sound from Vinyl except for this distortion.

I have a take on the Technics Decks. 

I have not had an audition of a SP10 Mk III so can't comment on the performance of the TT in general or especially a individual one with a assessment being offered about a problem which is suggested as being a noticeable speed fluctuation, that when detected can become a detractor that is seemingly unattractive to the TT's owner.

I have received demonstrations of at least Five SP10 MkII's beyond my own one, a few of these have been heard for quite extended play times, and two of these have been encountered in an environment when there has been multiple guests present to take part in the events.

All SP10 MkII's I have had demonstrated are models overhauled by the same EE who has carried out work on my owned model.

 I have also heard the SP10 R for quite extended periods in the Company of DD, Idler and Belt Drive TT owners.

At no time from any recollections of conversations had, both as Group Discussion, or as a aside discussion, has the subject of noticeable speed fluctuation been on the agenda.

To take this one step further my own SP10 Mk II was used in a demonstration of my main HiFi System at a Public Event where 500 Public attended.

My Demonstration Suite was pretty much full to capacity for a large proportion of the day, and on a few occasions attendees in the room were very vociferous in making their observations known.

Not at any time was a discussion had about a noticeable speed fluctuation from the TT.

I don't disbelieve a speed fluctuation is detectable on a SP10 Model, in the same way I don't believe all Idler and Belt Drives have a detectable Speed Fluctuation, if the basic set up is correct the Idler and Belt Drive should rotate at a very accurate speed rotation.

Maybe the speed fluctuation being referred to on the SP10 is not ubiquitous to all SP10 Models and only shows if there is something not quite right with the basics of the TT.       

I have yet to audition the SP10R, so I don't know if they have solved, or lessen, the problem I have with the SP10MK3. However, since a lot of users are perfectly happy with the SP10R and SP10MK3, I suspect this problem may be user dependent, some of us are just more sensitive to it than the others. If you don't experience the fatigue, both of these tables could be a very good choice!

My experience with TT's has been to use a Belt Drive in the earliest days of building  a HiFi System.

For a Proportion of the 90's I used a Belt Drive TT.

From shortly before or shortly after the Millennium I started to use Idler Drive and it was the impression this TT was able to make, that got myself into learning about different ancillaries to be used with it.

I used this Idler Drive for 14 years and then changed it for a modern thought out approach to a Idler Drive, where I acquired a PTP Solid Nine > PTP Bearing and a Speed Controller.

Very shortly after this I was introduced to a Technics SP10 Mk II DD, where the TT belonged to an EE who had become very familiar with the TT and have their own Mod's to be used on it.

Various Idler Drives including my own and the DD was at a comparison day, and not one Idler Drive was able to impress me to the extent the DD was capable of.

I received a demonstration of the my Idler Drive and the DD are the home of the EE, where the outcome was that I signed the dotted line for the DD and Tonearm Purchase and have not looked back with any regret.

A Friend who is a long term Belt Drive owner/user, a short term Idler Drive owner /user, when hearing my TT, chose to go for the SP10 R > Glanz Tonearm to have the latest technology used in their system.

A similar story for another friend who is a long term Belt Drive user as well, following being demonstrated my DD TT and Tonearm, they purchased a identical set up.

Prior to my knowing these individuals through a local HiFi Club, they were both quite familiar with another members SME 20/12 > SME V, I have also through club participation become familiar with the SME TT.

The SME owner has now gone for a Idler Drive > Origin Live Illustrious in a lightweight Plinth Design, not adopting the usual Massey type.

When an individual becomes Wed to a performance offered by a TT, it looks like for some and probably many, they will follow their own instinct for what they feel is right for them.

Only the ears as the tool will enable the necessary information to be processed and allow the individual to confirm for themselves what is the most attractive to their unique preferences and a satisfactory assessment be carried out.

I do not see a description being the best method to be used to evaluate the  differences to the sonic trait that each drive mechanism can produce.                    

Personally, I find the SP10MK3 score hi on the "HIFI" criterion, but I start to develop listening fatigue about an hour into the listening session. Many audiophiles would attribute this to the rapid speed correction, so call hunting, of the SP10MK3.

 

I don't know whether the SP10R is in a similar situation, but can't help to wonder if the added weight actually smooth out the speed hunting by making it harder for the  motor to adjust the speed rapidly!

@thekong once your ears are catch the DD distortion you will always catch it, no matter which DD you hear. Every direct drive TT has this issue of hunting which results in a non-continuous flow. The brain works to fill/interpret the gaps hence the fatigue. I have tried many DDs now, it is true with every one of them. Dont bother with DDs if you cannot stop bothering with this aspect of distortion.

 

@thekong and @pindac The fact that you gentlemen responded to the SP10's in divergent ways points is very interesting: in the end to are affected by sound in very different ways.  However, I am wondering if there is a DD in general, or SP10 in particular, sound signature that you can point to that sets it apart from the Verdier. I have read about the DD sound or the idler sound, more attack, dynamic, ..etc. There must be a lowest common denominator in the SP10 sound signature that sets it apart. And therefore it appeals to most with a few detractors. Just curious,

I think the Copper Mat Helps allot, I have not touched the Copper Armboard, its packed now so i dare not experiment on the sound but i am sure the stainless steel and copper armboards will outperform the Alluminum armboards.

The SP10-R I have put up for Sale has the following:

 

Acoustand Solid Aluminium Plinth in XL Version, which is larger and heavier than the normal one they sell.

I have the Stainless Steel and Pure Copper Arm Boards Fabricated for this plinth which can accommodate any arm you want.

I was using it for about 2 weeks with a Acoustical AXIOM Anniversary Edition Tonearm which is also going up for sale soon.

never once did it feel fatiguing, however at all times i was using a heavy copper mat and heavy record weight.

 

It is a oustanding Peice of engineering, The Plinth really helps allot. I also have the Glanz Tonearms, Hanna Carts matches very well.

I have been listening to a SP10 R > Glanz 12" > Miyajima Cart'  in another system on quite a few occasions.

The listening sessions are usually arranged over 4 Hours with a break for lunch.

Not at any time have I detected a presentation that is perceived as fatiguing or strained.

I am not ware of anything that can be suggested as a detractor when LP's are used in this system as a source.

My own TT is a SP10 MkII that has been modified by a recognised EE in the UK who has many years of working with them.

Again the similarities to the SP10 R is quite noticeable and it is my TT that was the influence that encouraged to the SP10 R owner to buy this TT. 

Interesting discussion on adding heavy mat and record weight on the SP10R! While I have not auditioned the the SP10R, I do have experience with the older SP10MK3. Personally, I find the SP10MK3 score hi on the "HIFI" criterion, but I start to develop listening fatigue about an hour into the listening session. Many audiophiles would attribute this to the rapid speed correction, so call hunting, of the SP10MK3.

 

I don't know whether the SP10R is in a similar situation, but can't help to wonder if the added weight actually smooth out the speed hunting by making it harder for the  motor to adjust the speed rapidly!

@phantom_av Your description of the SP10R is much appropriated, a world class table that is ‘ plug and play’, not the tweaking Verdier. Fortunately for me, I am a boring person with really only one expensive hobby, so no other endeavors require funding. However, I have a self imposed moratorium on audio purchase this year ( tweaks no included ), the sale of your SP10R is really bad timing for me. 

I do want to mention that I have the habit of keeping the Verdier on the entire duration of the listening session, several hours at a time. I start by using a strobe, and letting the Verdier run faster than 33.3rpm, drop the needle and make the necessary adjustments. Granted every record affect speed differently, but I hear less speed fluctuations, or so it seems.

I actually like the SP10R allot and debated with my self constantly on selling the verdier and keeping the SP10R as the speed stability and overall SQ

once the SP10R is setup properly it excell in almost all aspect the bass on the SP10R is the best iv heard and best the verdier many times over.

. However the Verdier has been my oldest table, I have already put on order for the motor, spent allot on the Armboards which is made from copper and stainless steel and already spent allot on the platform and the Solid Wooden blocks made from burl to fit the the whole design interor of my new room.

 

I cant keep them all otherwise i need more arms and more carts and another phono stage and the cost keeps mounting up. I put in a order for the SP10R after i spent time at a friends house over a long period of getting familer with it so i love the table allot but Technics took so long in the delivery with maltitude of excuses on the production and since its limited it has a better chance of selling than the  verdier hence i let this one go to fund another Hobby of mine in Diving.

 

The SP10R is a absolute monster, With the right arm, right cart and right armboard and platter Mat it can compete with much higher costing table at a fraction of the price without the hassle of speed stability issues. Its plug and play.

@phantom_av May I ask the reason for keeping the Verdier and selling the SP10R? The SP10R should have no problem keeping speed. 

Btw their are other users of SP10R which are using 3-4KG copper matts for a long time no one ever has reported an issue.

I will advise on this forum soon as i have the motor system and setup for the Verdier Table, I need to experiement and make sure the dealer is genuine before i can let others know, if i get scammed i dont want others being scammed too based on my info.

Thats Strange, i was advised by a SP10R user the Copper mats are fine to use his been using his for months now with no issue.

 

I have about 6 copper Mats the lighters one is too thin, the second in line is a genuine Micro CU180 which sounds very good, the higher you go with the weight the better to my ears the sound gets. This is the same results a few of my friends had none of them have had issues, most people know the motor system on the SP10R is strong enough to handle it.

Anyway i decided to sell of my systems, not only the turntable but the bigger speakers i have and the amplifiers, we basically downgrading to smaller systems now.

I recently loaned a SP10 R owner after their hearing the impression it made,  one of my heavier Record Spindle Weights that is 1400grams(1.4Kg). 

When discussing the merits of the added weight with the supplier of the TT, they were informed that the TT has a max capacity for added weight as advised by the manufacturer of 1000grams (1Kg).

The following is from a review of the SP10 R and touches on the same subject about added weight to the Platter.

The main chassis is also cast aluminium. There are three speed selector buttons and a large square Start/Stop button. The unit runs at the default speeds unless adjusted, whereupon a small blue indicator LED turns orange. Turning power off then on returns to default speed, not last adjusted speed. However, dimmer and torque settings are retained at power off/on. A record clamp weight of up to 1kg is suitable, but not supplied. A rubber mat is supplied, but our pictures show the bare platter to reveal its construction.

@phantom_av Would you list the brands of the motor / controller? I would be interested. Thanks!

BTW, I saw your ad for the SP10R. I especially like the acoustand derilium plinth. It is beautiful!

So i decided to downgrade my rooms, Actually im oving out from the current property to a smaller one.

As a result i put up some of my Field Coils Speakers, OTL Amps and Pre-amps for sale.

I also put up my SP-10R up for sale which i only spent less than 3 weeks with, I think it is an absuly musical machine ones you put down a 5kg Copper Mat on to the Platter. The sound changes compleatly. It sounds more relaxed and laid back  but with a locked in sound stage.

Having too many machines and its is costing me more on arms and catridges and i need to sell off stuff to fund other hobbies which are not audio related. I love Diving so im taking that on another level now.

 

Back to Audio, I have ordered 3 Motor System with a sensor lets see how this works., The controller is from Japan and the motor is from korea. Uses a senstor to constantly adjust, i will experiement later once i have relocated to a new room.

@richardkrebs Thanks, Ricahrd for your insight, torque spec. ..etc.  My exploits will most definitely not scale the heights of K3 territory.  But from your description of the motor / controller search, it was truly a project from the gound up. 

@phantom_av  Please take a look at the SOTA Eclipse. SOTA has recently developed its own power supply that will run both the Condor motor and the Roadrunner. 

For my part, after a brief search on motors,  I will as a first step embark on a project to convert the existing motor control  into a battery operated one. May be the mostcost effective option to improve on the SQ . 

ledoux.

The motor I described is what I used in my design of the OMA K3 turntable. I found the constituent parts online after a 6 month search. I had to make the motor from these parts.  Being direct drive, I have optimised the motor for low speed. You need higher speed to suit the Verdier, but the same basic specs apply.  

The controller was also found after a 6 month search. The combined cost motor/controller is massive.  Ultra high count feedback adds $Thousands more. 

But there must be motors and controllers out there that are suitable. Look for 3 phase synchronous motor around 0.1 Nm or more torque, if you are intending to use thread drive and appropriate speed capability. A little higher torque and lower speed if idler.  Good motor manufacturers will specify torque ripple. Less is more.

I haven't researched the Eclipse controller but thekong mentions that it can drive a 3 phase synchronous motor, so that would be a good start.

 

@thekong I preface by saying I am really quite lost AC vs DC. However, in the case of SOTA Eclipse the Condor motor control is driving a 3 phase DC motor ( ? ). And the Longdog audio LDA is designed to drive an AC motor (? ).  According to Nick, the existing Verdier DC Philips motor cannot be controlled by the LDA, hence a search for an AC motor if I go this route. 

 

@richardkrebs Richard, given the issue at hand, the search for an after market motor / controller to drive a 18kg platter on magnetic bearing on the Verdier deck, how would you advice? 

@ledoux1238 , thanks! So, basically it regenerates the power and control speed by changing the output frequency! Unlike the SOTA Eclipse, the LDA doesn't have the feedback function, so you have to adjust speed with some sort of probe. I wonder what the adjustment steps are, ie 0.1Hz or 0.01Hz etc.

 

One of the advantages of the Eclipse is the 3-phase controller, which I found very beneficial for AC synchronous motors. On the other hand, the LDR webpage seems to indicate it would fit the asynchronous motors of vintage idler drive turntables better!  If you are getting either one, I would be very interested to know your findings!

 

Best,

 

 

@ledoux1238  This is good news that there is a option on the table, supported by a very skilled EE.

My thoughts on the the LDA Quartz Lock Controller, is that it was produced to be used in very similar situations, to bring a Vintage TT, into the modern world in relation to Speed Control .

Your own intentions will be very closely aligned to this purpose as well.

I am anticipating a positive outcome and your needs will hopefully seem to be more than surpassed.

AC vs DC. While I fundamentally agree with Dover, a few points he raises need expansion.

Not all AC motors lock on to the field frequency. What we should be talking about is synchronous motors.  In this design the rotor follows the rotating field in the stator at the same speed, but not the same phase angle. IOW the rotor is running slightly behind the rotating field in the stator, but at the same speed. There is an angular displacement between the two. No displacement, no torque. This angle is determined by the load the motor is seeing and the motors design. More load equals greater angle, where the motor momentarily slows until the torque it produces equals the higher torque demand. Maintain that higher load and the angle will stay at this higher figure. Reduce the load and the angle will similarly decrease and momentarily the rotor's speed will increase. The rotor maintains an average speed dictated by the rotating field, but when driving a dynamic load, its real-time speed is changing at microscopic rates. Some synchronous motors are very stiff. This means that the increase in displacement angle is very small for any given increase in load, others are comparatively loose where the angle increase with load is correspondingly larger. 

Further adding to the mix, the change in angle vs load is not linear. As the angle increases the motor draws more current to self correct, but it first needs to increase the angle, thus slow momentarily. It has go wrong to correct. It is feedback. The correction is sinusoidal so we can assume that this is more benign. But, as above, the point to point speed can be changing when playing a record. There is no free lunch.

Most synchronous motors used in TTs are 2 phase. We need a way to generate a phase shift between the two phases in order to make the motor rotate. This can be done with something as simple as a capacitor all the way up to sophisticated regenerator controllers. If you are targeting smooth, ultra low torque ripple you want to use a 3 phase synchronous motor. Well designed 3 phase synchronous motors are virtually linear torque devises. Of course the controller needs to be capable of driving such a motor by generating three phases, 120 degrees apart 

If one was designing a TT today, where we were aiming for great dynamic speed stability.  A logical strategy would be to use a 3 phase synchronous motor that is very stiff and of sufficient intrinsic torque to dominate the platter. Then wrap a very high speed, but gentle, feedback loop around this to make the drive even more speed stable. 
 

Cheers 

 

 

 

@pindac Thank you for the words of encouragement from the last post. 

Well, after some back and forth, Nick Gorman has agreed to adapt the LDA to a new motor, if I can source one. @dover is there a AC motor that you could readily recommend? Or would I be looking at vintage / idler type motors to adapt to? 

@ledoux1238 You have done the correct thing in contacting Nick Gorman, he is with knowledge levels that are beyond many EE's, if there is a method and a simplified one available Nick will see it.  

As for being out of your depth, nearly all that I own is bespoke built by EE's and Engineers who excel in certain disciplines within HiFi, this is where the two edge sword swings.

When the sword swings one way, I am most confused by what is under discussion, as a proportion of the methods employed are unique to the individual, with an area of the work to be being undertaken, being unique and their own stamp on a design, drawn from their years of experience.

When the sword swings the other way, the experience of the working design in use and as time of ownership passes, where comparisons have been undertaken and others have received demonstrations of the devices offering their assessments.

This furthering of the experiences does undoubtedly identify that something special has been done for you, and this knowledge is very satisfying, especially when some of your owned devices are being recognised as being more attractive in use than much more expensive 'off the shelf products' they have been compared against.

It is also nice to find a place of rest in the knowing the search for a particular device is definitely seen to be over.     

As all with many years of enjoying music replays on a HiFi System know, we are a 'curious old bunch' and always chasing a rainbow somewhere 😀.