Direct Drive vs. Idler Drive vs. Belt drive

The Saskia is driven from a very complex motor controller that probably synthesizes the AC supplied to the motor, designed and built by Mark Kelly for the Saskia. Mark probably also had a hand in selecting the type of motor (AC synchronous, etc) to be driven by his controller. Maybe Win Tinnon will chime in here.

Mijostyn, I wouldn’t be so sure about the value of adding the Eclipse system to a modern day SOTA turntable, unless I had heard an example both ways, playing music with and without the Eclipse. Have you done that? If not, maybe you shouldn't dismiss the Eclipse system so peremptorily. I don’t know how good is the base motor and power supply, so I too cannot say for sure that the Eclipse would improve SQ over the base PS and motor, but I do know that the Phoenix Eagle/Roadrunner system was a very worthwhile addition to my highly modified Lenco, which was beforehand being driven from an expensive "motor controller". The original motor controller was way better than AC from the wall, and the Eagle/Roadrunner was another step up from that. (If you don’t know, the Eagle/Roadrunner form the basis for the Eclipse system as licensed by SOTA, except SOTA add their own special motor to that package.)

neither the Saskia or CS port have servo controllers for their motors.

the Saskia does have an optical reader installed on the plinth in the platter well to allow for a feedback servo to be installed later for that feedback should that be preferred. Win has told me that he has no plans to do that.

obviously both my Wave Kinetics direct drive NVS and my direct drive EMT 948 have servos.

i view both the Saskia and CS Port as having the most steady tonal solidity of any turntable i have heard. the NVS and EMT are also very fine at that 'steady' and 'solid' type sound. only that the Saskia and CS Port are degrees more grainless and liquid, as well and greater tonal shading and density.

Dear @mikelavigne and frieds: Mike,with all respect servos per sé are not a devil it does not matters where you use it. For your coments in this thread seems to me that that word over distress you and with out any single reason/facts true3 facts or measured ones. You have a " feeling " about when you said:

"" i view both the Saskia and CS Port as having the most steady tonal solidity of any turntable i have heard. the NVS and EMT are also very fine at that ’steady’ and ’solid’ type sound. only that the Saskia and CS Port are degrees more grainless and liquid, as well and greater tonal shading and density ""

that’s what you like it and nothing wrong against that but the Saskia and CS Port TTs are both way different whole designs against the @jtinn great NVS DD design, even the CS Port comes with its dedicated LT tonearm.
Mike there is no way that those 3 different TT designs can sounds almost the same. Again that " degrees more gainless and liquid " is what you prefer.

Now, let me explain something in that overall rectification speed controllers subject including the servo " devil ":

exis different kind of servo designs using different " tools "/technologies to do it: cristal quartz look ( that normally we can disengage. ) is one of them and one of the technique used in the vintage DD TT and still today works really fine, there are servos that sense the speed over " thousands " times at each TT rpm and are " there " only when is need it a speed rectification even exist bi-directional servos as in JVC, Yamaha or Denon TTs.

Other than TTs subwoofers use servos and as the now defunct Velodyne they did it through an patented accelerometer that sense the wooffer movements over 80K times each second to mantain the THD lower than 0.5% at 20hz at 120db on SPL. Your speakers subs has to have some kind of controller to its low bass range stays with low distortion levels, you can’t avoid it.

This is what the motor designer of the Saskia posted:

https://db.audioasylum.com/mhtml/m.html?forum=vinyl&n=1081734&highlight=saskia&r=&se...

This was posted by Sakia manufacturer:

https://db.audioasylum.com/mhtml/m.html?forum=vinyl&n=1117513&highlight=saskia&r=&se...


Mike, you said:

"" the Saskia does have an optical reader installed ...."

I can think that that optical reader is to make speed rectification/corrections when is need it. Same function as any servo speed controller.
If you can detect the servo operation then you must detect this kind of rectification no matters what and if you don’t did it then both the servo and the optical controllers has no real/true intrusion in what any one ( including you. ) can listen or that can say exist an " intrusion " because in both cases exist a " change to the TT speed "/a correction to.


In 2014 @richardkrebs posted about that optical controller type:


""" Dougdeacon said...

"No strobe (Timeline or otherwise) operates in short enough increments of time to detect micro-/pico-/nano-second variations. Knowing that a TT is speed stable across a time span of minutes tells us nothing about how stable or unstable it may be across a few thousandths or millionths of a second. Such short-period variations are just as audible and musically important, arguably more so."

Brilliant. This is so true.

Tonywinsc also touched on the same point.

IMO it is the reduction of these tiny speed changes that is one key to a TTs performance. Do we have a way to objectively measure this? Maybe, with some of the new optical speed sensors capable of measuring greater than 1x10^6 counts per rev, but I sure know that we can hear it. """




In the other side and about the CS Port BD TT and only looking at its specs I can say that are really poor against today/vintage top standards in that regards. These are those specs and certainly you must listen to it:

"" Crystal follower non-feedback motor drive

XFD method.

Rotation transmission method Yarn drive (four-wire aramid fiber).
Drive motor DC coreless low-noise motor
Rotation speed33 1/3 ・ 45rpm (with switch selection and rotation fine adjustment)
Rotational speed accuracy±0.3%
Wow and flutter:

Wow 0.2%

Flutter 0.04% or less """

I already posted that I can’t detect any disturbances in what I listened or listen through Denon and Technics top models due to its servo speed controllers.

I can’t detect either any " intrusion " by speed motor drive corrections in my BD Acoustic Signature unit where I use as a belt either: aramid fiber thread or silk thread. Btw, I neither detect it speed controller intrusion with my Micro Seiki TT.

I have to say that I never had in my system an ID TT.

I insist in this " devil " TT subject because as I posted before the servo controllers are the ones used in all recording cutting lathe DD motors and no one can detect till today any trouble because of that in any of his LPs.

For me all those means exist no true problems about and certainly no objective facts.

I know that for all audiophiles and everywhere, including you, could be really a learning " sessions " that both: @mosin and @jtinn be so kindness to chime about because the issue is way critical.

Gentlemans both of you thank’s in advance and appreciated.

Regards and enjoy the MUSIC NOT DISTORTIONS,

R.

Dear @rauliruegas

i’m not anti-servo, but appreciate the liquidity and tonal density that absolute steady speed and continueousness can deliver. maybe this explanation will help you to understand what a properly designed non servo turntable can deliver.

In order to pick up sound accurately from the analog disc, the rotation of the platter must be rotated at a constant speed without any “fluctuation”. In general, accurate rotation is obtained by servo control by negative feedback, but at the micro level, if it rotates or becomes faster, it detects it and slows it, and repeats the operation to make it faster if it gets slower. Although this level and cycle are determined by the gain of the control system and the loop speed, the period of the speed control of the platter which is the mechanical system surely comes into the audio band. In general, accurate rotation is obtained by servo control by negative feedback, but at the micro level, if it rotates or becomes faster, it detects it and slows it, and repeats the operation to make it faster if it gets slower. If you try to measure a period with a small level, you can not measure the instantaneous state, so you measure the average value. Therefore, fine vibration generated by servo control can not be measured by the measuring instrument, it depends on the human ear.

my ears tell me it can be better (i prefer it mostly when properly executed) without the servo.

but this is not to say that turntables with servo’s are not fantastic at playing our records, they simply are not the pinnacle at steady-ness.......and the benefits that can bring.

at modest build levels this theoretical stuff is lost in the execution. it takes fairly heroic design and build efforts to allow non servo to show it’s stuff. 

Dear @mikelavigne : With servo or optical or whatever speed controller we use it happens exactly the same:

" but at the micro level, if it rotates or becomes faster, it detects it and slows it, and repeats the operation to make it faster if it gets slower. "

The TT platter rotation speed is affected by to many circumstances not only if the motor is DC or AC one and it does not matters the drive kind of design TT has.

Some of those circumstances that affects speed stability in the extremely short period of time are: stylus drag at high velocity LP recorded grooves and this could happens any time at any LP surface positions, electrical power source, even some one detected that static developed can impair the function of the speed controllers by million of a second time periods, non perfect flat leveled TT that could affects the platter bearing stability, as the cartridge stylus tip the TT bearing goes degrading through the time, belt degradation, pulleys suffers of that degradation too as the ID internal mechanical parts, even the speed controller has a time degradation too.
All those circumstances and many others makes a TT imperfect item suceptible for the speed controller goes in/out trying that the speed stays stable in the very short time.

That’s why I ask for mosin/jtinn or any other TT manufacturer in this thread but even if no one can comes the reality is that you can’t detect it those extremely fast speed rectifications because you can’t detect those speed rectifications that were do it for the cutting lathe through his speed servo controllers. The cutting lathe Technics motor ( SP02. ) use the same servo than the SP10MK3 ! !

But all those cutting lathe motors are way vintage designs and even that old speed controllers designs you can’t detect it those servos in any of your LPs played trhough the Saskia or CSPort ! !

You can stay entitled to your way of thinking but it’s only that " a way of thinking " a subjective way and not a true fact/objective because you can’t hear it in any TT drive design at any price levels.

Now, it’s not here if you are rigth or wrong but the matters is if really exist what you think or just does not exist as I support.

I know very well @lewm and he owns ID and DD different TTs and that I remember he never posted that can detect a problem about but it’s not the only audiophile because there is nothing that proves that non-existent symptom. Other gentleman is @cleeds and I can name you several more including the gentleman you know very well that’s an AS BD all metal design distributor or manufacturer ( I’m not sure about. ), the one I linked the wbf here.

Mike, with all respect: as a cartridge or speakers or electronics any TT design is the sum of its parts inside the whole design and you are taking only one part/characteristic/parameter of that whole design where things are that all TT designs, one way or the other, shares in between no matters what.

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.