Turnable database with TimeLine

01-03-14: Richardkrebs
Many years ago I owned a Goldmund Studio. In an attempt to improve it, I built a larger power supply. I scoped the supply output while playing a record. To my amazement I could see the supply output voltage being modulated by the music I was playing. There is only one conclusion that one can draw from this finding. ... The platter speed itself was being modulated by the music in the form of stylus drag. This was occurring even at quite high frequencies. It is likely that the Goldmund would do well in the time line test, since it's average speed would be close to the mark. But what was happening on a micro level was a completely different story.

I thought this thread was to be a database of timeline checked turntables - not a guessing session.
I heard that modified Goldmund mentioned above on numerous occasions and it got slaughtered by a stock standard unmodified Kenwood L07D. It was shown to be so bad in terms of musical timing that the owner promptly went and bought a Technics SP10. So either the mods were deleterious to the performance, or the Goldmund is not stable. Whether it would pass the timeline test is speculation. If it does then clearly the timeline test is not an indicator of whether a turntable will preserve the musical timing as recorded.

There is only one conclusion that one can draw from this finding. ... The platter speed itself was being modulated by the music in the form of stylus drag

Since you failed to measure the platter speed, then your conclusion is simply a guess.

01-03-14: Richardkrebs
Yes the Goldmund used a JVC motor.
Like, I suspect most DD designs, it is a synchronous motor. The rotor ( platter) is compelled to follow the rotating field, back slightly in phase.

I'll explain how the Goldmund motor really works.
Firstly Brushless DC motors require an electronic controller to continually switch the phase to the windings to keep the motor turning.
Secondly, the Goldmund Studio uses a coreless DC servo JVC motor. The JVC motor has a frequency generator which generates a frequency when the motor is running. A phase comparator then compares that motor generated frequency to a reference frequency generated separately by the Quartz Crystal. Any difference detected is then fed back to the servo controller to correct the speed. The motor will not run or hold speed without the servo running.

In a nutshell the speed accuracy of the Goldmund will be dependent on the quality of the electronic controller and the quality of the servo.

Note that Goldmund themselves then added lead mass to the platter to increase the inertia. They claimed that this was required to smooth out any speed irregularities. Clearly Goldmund themselves did not believe that properly designed servos are adequate in of themselves for accurate and consistent speed when they designed the Goldmund Studio. The Goldmund Reference TT was belt drive, high inertia.

Brinkmann allude to the issues of servos in their white papers. They have gone for a low torque minimally invasive ( S L O W ) servo action in the interests of sound quality.

It is interesting to note that in listening tests comparing the Goldmund Studio and the Kenwood L07D side by side, the Kenwood has better timing, despite the servos not kicking in until a speed error threshold of +-3% is reached. The Kenwood L07D relies on inertia and back emf within the motor to hold the speed.

01-03-14: Richardkrebs
The rotor lags in phase slightly behind the rotating field. If it didn't it would produce no torque. Increase the load and this phase angle increases and the motor draws more current. But the motor then continues rotating at the same speed. .

If the phase angle increases and the motor draws more current, this means that the motor has lost speed. The servo kicks in and brings the speed back up.

01-03-14: Richardkrebs
This is what I observed on the scope. The motor was responding to stylus drag, literally note by note. It was not showing a problem, it was showing the motor working properly and the relative enormity of stylus drag.

The conclusions from your testing are wrong. What you are measuring on the scope is the solution that Goldmund has provided to record playback. You are measuring the sum total of the quality of their controller, their motor, the inertia built in to the platter and the quality of engineering and design for THAT particular turntable. You have not measured the platter speed.
If you had scoped the power supply of a Garrard idler, Micro Seiki or EMT you would get different results.

01-03-14: Richardkrebs
For a DD drive, it has a reasonably high inertia platter but this was not enough to "push thru" these load changes. .

The Goldmund Studio does not have a high inertia platter. The Goldmund Studio platter weighs about 3kg. Both the Technics SP10mkIII (11kg) and Kenwood L07D (7.7kg with stabiliser) DD’s ( comparable products in terms of market positioning ) have significantly higher inertia - 2-3 times higher.
Of course the Micro’s are 10-15kg, EMT 927 5kg distributed to a 16” platter to achieve an equivalent 50kg, and my Final Audio has 22kg. These are what I would describe as high inertia TT’s.

01-03-14: Richardkrebs
Wrap a properly designed servo around this type of motor and the phase angle change with load is reduced. .

There is no consensus on what is a “properly designed servo” for Direct Drive turntables.
The Technics SP10 servos use algortihms to estimate predicted errors and employ rapid response times (limited by the technology of the day). The servo action includes error and overshoot.
The Victor/JVC decks use an averaging process to provide a smooth transition when servos call for speed correction.
The Kenwood L07D uses no servo, and relies on inertia and back emf unless the speed error is quite large, at which point the servos kick in and additional torque is applied.
The Brinkmann uses very slow servos for soft recovery.

In reality the L07D and Brinkmann DD's are closer in conception in maintaining accurate speed behaviour to a high inertia, non servo AC synchronous motor driven solution like the Micro or Final than they are to the Technics SP10. I also note that Brinkmann claim that 15kg is the minimum platter weight required for adequate speed stability.

Addendum to above post :
The big Micro's use DC motors with frequency generated servos built into the motor. So their response to speed issues has the same issues as the direct drive, the main advantage of the micro's is the large inertia. This would explain why some users prefer the Micros set up with a controlled slip by chalking the thread.
The Final Audio has a high torque ( the 22kg platter can achieve full speed in less than 1 turn ) AC synchronous motor with precision oscillators and 80 wpc power amplifier to lock the speed.
As Lewm alluded in his post the AC synchronous motor responds to phase lag by self correction. This is why AC synchronous motors can run accurately without servos. A DC synchronous motor will self correct to some degree, but the self correction is less sinusoidal and less smooth than an AC synchronous motor.
It is wrong to imply that the Technics SP10 relies on self correction of phase lag - its servos are active all the time, as is the case with the Victor/JVC and Goldmund.

Lewm
Interesting you mention the Kodo Beat. I have been following the evolution of this TT with interest, given it uses similar principles to the Final Audio.

01-04-14: Richardkrebs
The Beat appears to uses electromagnetic drag to "pre load" the motor. Moving the rotor back in phase relative to the rotating field.

Richardkrebs statement is wrong. It is the bearing that is preloaded in the Kodo. For those that have a grasp of basic engineering principles this is a common technique to assist with speed stability. Garrard used it with their eddy brakes. By including a drag component in a moving bearing the motor is always loaded to a minimum level. Preloading the motor so that it is working at a minimum level can help with speed stability.
I quote from the designer of the Kodo Beat review in Stereomojo :

The Beat has only one moving part: the bearing. Since this is the only internal source that can impart noise to the record, much care was taken to develop the bearing. Over engineering describes it nicely. It has a 25mm diameter spindle that is capable of handling a 100 pound plus platter (and yes, I did try one). There is a degree of resistance built in to the bearing and it too can be adjusted.

Now in terms of the AC motor itself, I quote from the manufacturers website:

The issue with DC motors is that their speed is affected by the load. That means they need a control circuit. The control circuit can make the average speed near perfect but this is achieved by constant speed adjustments so there will be constant small speed variations. Many high end tables have used extra mass in the driven rotational mass (platter) to help hide the speed corrections.

The answer came in the form of a huge 3 phase AC true synchronous motor. What makes this motor the best choice for a turntable is that its speed is not affected by load changes such as stylus drag and bearing oil temperature. When the load changes, such as stylus drag (yes, it is real) in complex music passages and heavy bass lines, a synchronous motor instantly draws more current and supplies more torque to the platter. This makes the controversial matter of stylus drag a non-issue. Because of this behavior, this type of motor does not need any form of servo circuit to control the speed when fed the proper power.

So contrary to the statement by Richardkrebs above, AC synchronous motors lock in and do not “phase lag”. If an AC synchronous motor sees additional load, it automatically draws more current and supplies more torque to the platter.
From the manufacturers website

This power is supplied via a sophisticated and very accurate power supply designed to give The Beat clean and consistent power with correct frequency, no matter how dirty your mains supply. This power supply also gives the audiophile another feature, adjustable motor torque. Every listener seems to enjoy a slightly different take on his music so The Beat lets you adjust the torque of the drive system.

In summary, the Kodo Beat TT includes:
High torque AC motor with no servos
Carefully designed platter weight (11kg) to match the high torque AC motor
Accurate power supply that provides the correct frequency to lock the AC motor regardless of the mains power
Adjustable torque controller to optimize the drive
1” bearing designed for loads to 100lbs+.

In comparison the Final Audio Parthenon, built in 1971 uses :
High torque AC motor with no servos
Carefully designed platter weight (22kg) to match the high torque AC motor
Accurate power supply that provides the correct frequency to lock the AC motor regardless of the mains power ( Sine & cosine wave generators and power amplifiers are used in the Final power supply )
Adjustable torque controller to optimize the drive ( prior to the Beat, the Final is the only TT I have seen with adjustable torque ).
1” bearing designed for loads to 100lbs+.

The differences between the Beat and the Final Audio Parthenon are :
The Beat utilises Magdrive, the Final Audio is thread drive.
The Beat appears to use a conventional T bearing ( that’s T for Topple in engineering terms ), whereas the Final uses an inverted bearing placing the centre of gravity of the platter well below the bearing point.

The closest equivalent for the Final Audio TT is its granddaughter - the Kondo Ginga at quoted retail prices of approximately US$80k

In my view the Kodo Beat is a well conceived design and at US$24000 appears to be a bargain.

01-05-14: Richardkrebs
Regarding the eddy current brake as used in the Beat TT

Please quote the authority to substantiate your assertion that the Beat uses an eddy brake ?

01-05-14: Richardkrebs
Regarding the eddy current brake as used in the Beat TT
Go to teresaudio.com and follow the link...micro precise speed technology.
The Certus motor.
As I said earlier, this is an elegant design.

You have incorrectly claimed that the Beat uses phase lag to pre load the motor.

01-04-14: Richardkrebs
The Beat appears to uses electromagnetic drag to "pre load" the motor. Moving the rotor back in phase relative to the rotating field.

The Certus does not preload the motor using phase lag as you incorrectly claimed in your post re the Beat TT.
The white paper you refer to confirms my comments that the motor is preloaded from additional drag provided by the eddy brake, not the phase lag as you have claimed.

Halcro = I dont own a timeline, I borrowed it from the local audio shop here. At some stage when I can get hold of it I'll post a video. The Albinoni is great.

Can anyone here emulate this -
The Final Audio turntable can maintain speed whilst someone is banging on the record with bare knuckles while it is playing ....
Bare Knuckle speed test
High torque AC synchronous motor with decent power supply, 22kg Platter, silk thread and decent record clamp. No servos required.
Anyone up for the challenge...

01-08-14: Richardkrebs
HF Dover
Phase lag is a result of drag, not a cause of it.

Yes, phase lag COULD be a result of stylus drag, but not necessarily exclusively.

As a matter of courtesy, I would ask you to address me correctly as "Dover" which is my name on this forum.

Richardkrebs - the music you inquired about is Cantigas de Santa Maria #77 - sounds like Jordi Savall - he performs in Auckland from time to time during his world tours. Highly recommended.

Halcro
You have mistakenly attributed the following quote to Richardkrebs.

01-09-14: Halcro
Richardkrebs is right.....
Why is speed so important? As you know, the primary job of any record player, including turntable, arm, and cartridge, is to accurately reproduce the waveform of the music as it was originally recorded onto a vinyl record....

This quote has been lifted from the pages of IAR Magazine compiled by J Peter Moncrieff - Article on the Rockport Sirius III turntable. I note the article is subject to copywrite. Following convention it would be appropriate to acknowledge the correct author.

01-07-14: Halcro
Peterayer,
I wasn't including you amongst those who have said that a very high-mass platter on a string or thread-drive turntable would be immune to stylus drag as you have admitted the fact......
Dertonearm and Dover I believe in the past (amongst many others previous to the advent of the Timeline)....have made such claims.

Halcro, I have not made the claim that a high mass platter is immune to stylus drag. No turntable is immune to stylus drag.
The unanswered question is how well do various turntables respond to stylus drag.

Proposed Test Procedure

In terms of Richardkrebs suggested testing procedure – stylus off and on: this is not is not a valid test. What we are wanting to quantify is the variation in stylus drag between a heavily modulated record groove and lightly modulated record groove. The test that Richardkrebs proposes compares no stylus drag to some undefined recording. This is unscientific as it lacks a control recording to standardise the test. The results will be random and the conclusions meaningless.

An accurate test procedure would be to agree on a specific record and tracks to be played. The record should contain a variety of tracks in terms of modulation. Then each person should play those tracks continuously from beginning to end. The sum total of the error at the end of this test will be truly comparable between turntables. As Tonywinsc suggested a meaningful sample would be 10 minutes, by which time any stylus drag error if it is significant would become apparent.

01-07-14: Halcro
Yet I have shown on my video of the Raven AC-2....the comparison when the stylus is NOT in the groove and I think that that gives a further comparison to both the motor, belt/string/thread and platter abilities of a belt-drive turntable......or ANY type of turntable.
Your comments (and Syntax's) about only being concerned by the performance when the stylus is tracking the record....is misleading.
I have recordings that have extremely modulated grooves and I have records which have very benignly modulated grooves.
I can adjust the motor controller to handle one or the other.....but unless the speed is manipulated for each and every record you play.......there will inevitable be a difference in the Timeline between different recordings.
This is why seeing the Timeline 'without load' in comparison to 'under load' is valuable. .

You make the claim that “unless the speed is adjusted for each and every record you play.. there will inevitably be a difference in the Timeline between different recordings.”. From your comments above this is only true of the Raven AC2. It is wrong to assume that all turntables behave the same as the Raven AC2. For example, do you find that you also have to adjust the speed on your Victor 101 for each record.

01-10-14: Lewm
It was very unfair of you to indirectly accuse Richard Krebs of plagiarizing Moncrief

Lewm, if you read my post correctly I said

Halcro
You have mistakenly attributed the following quote to Richardkrebs.

We may have a different interpretation of the english language, but I do not equate "mistakenly attributed" to mean "plagiarised". Do you not agree that one should acknowledge the correct source if one lifts several paragraphs directly from an article written by someone else - word for word ?

Halcro

01-10-14: Halcro
Dover,
You seem to be full of suggestions for how people should submit their tests....yet you have not posted a single video of your 'famous' Final Parthenon performing with the Timeline in any fashion whatsoever?
Up till now....my videos and that of the Fat Bob turntable used in the Timeline promotion on YouTube....are the only ones to my knowledge which demonstrate the reaction of the Timeline with the cartridge both playing the record and being dropped and/or lifted from the record.

Halcro - Did you miss the knuckle test I posted.
knuckletest

Regard the suggestions - the methodology of your Timeline test is flawed.
My proposal is for a more accurate and meaningful test that would provide consistant parameters under which all turntables can be evaluated.

01-10-14: Dover
Proposed Test Procedure

In terms of Richardkrebs suggested testing procedure – stylus off and on: this is not is not a valid test. What we are wanting to quantify is the variation in stylus drag between a heavily modulated record groove and lightly modulated record groove. The test that Richardkrebs proposes compares no stylus drag to some undefined recording. This is unscientific as it lacks a control recording to standardise the test. The results will be random and the conclusions meaningless.

An accurate test procedure would be to agree on a specific record and tracks to be played. The record should contain a variety of tracks in terms of modulation. Then each person should play those tracks continuously from beginning to end. The sum total of the error at the end of this test will be truly comparable between turntables. As Tonywinsc suggested a meaningful sample would be 10 minutes, by which time any stylus drag error if it is significant would become apparent.

Lewm, thanks for your kind words. I agree there is a lot of "junk food" on the net.

01-16-14: Richardkrebs
The goldmund feedback is very fast as observed on the scope current draw plot. Much faster than 0.3 sec . As I posted earlier, it was responding note by note. A startling observation.

I'm very keen to try this test on my Final Audio. Could you please explain, if I use Mahler's 2nd for the test, which instrument should I listen to for the "note by note" ? Tympani ? Violin ? 1st or 2nd ?...
Could you explain what scope you used and how you calculated your reported result of less than 0.3sec for the servo response.

Since you keep referring to the Goldmund Studio, could you explain the reasons you went about modifying the power supply - what were the deficiencies that you could hear that prompted you to modify the power supply. Goldmund claim in their brochures that they used a new motor with built in regulator and Quartz controlled speed with response times fast enough to be immune from power line variations and to use an unregulated power supply.

Could you also explain what differences you could hear when you sold the Goldmund to purchase your SP10mk3. I recall that you told me at the time that the SP10mk3 was the only Direct Drive TT that you could not hear cogging or servo correction derived artifices. You told me at the time that the SP10mk2 and Goldmund did not have enough torque and thats why we could hear timing problems.

Peterayer,
Halcros comments are contradictory. On the one hand he believes that DD TT's are inherently superior in timing to Belt Drives. Then he states that no one can hear any difference between his belt drive Raven and the DD Victor. This would only be possible if the system itself has poor timing and cannot demonstrate the superiority of the Direct Drive.
The other contradiction in Halcro's post is that he claims that he can hear the effect of a drop in speed from 33.33 to 33.32rpm. The Raven cannot hold the correct speed as shown in his timeline test above and has a speed error that exceeds the drop from 33.33 to 33.32rpm. Therefore either the statement "no one can hear any difference" is wrong or "I can hear the speed drop from 33.33 to 33.32rpm" is wrong.
The other observation is that Halcro runs different tonearms on the 2 turntables.
Given the level of investment in his system I would not be happy if I could not hear any differences between tonearms.
I can only assume that since Halcro seems happy with the belt drive Raven which cannot hold the correct speed then he must be be a member of both the subjective and objective groups.
Peyerayer, since I prefer my Final Audio Parthenon thread drive to both the SP10mkIII and Kenwood L07D, then by Halcros definition I am a subjectivist. I am quite happy with this, because if I was an objectivist then I would simply read the musical score to attain the perfect performance as no live performance or audio system can be "perfect" and music would only exist in theory.

Lewm,
I dont have any preference as to direct drive, thread drive or rim drive. I prefer to make my decisions based on listening. I have owned all 3 drive types at various stages. Turntables owned and/or used in my own system include - Garrard 301/401, Townsend, Well Tempered, Sota, Oracle, Pink Triangle, Logic, Kenwood DD, Oracle, Goldmund & Final Audio to name a few.
TT's with the ET2/Carnegie Model One I have heard include Townsend, Sota's ( many ), Oracle ( several ), Final Audio, Goldmund Studio ( 2 of ).
I also own a Dynavector DV501 & Dynavector Nova 13D cartridge ( along with many other cartridges and arms. Incredulous as it may seem a customer here in New Zealand had up until recently a Dynavector 501/Nova 13D combination mounted on an L07D. I have run the Dynavector 501/Nova 13D many times on the Final. The same Nova 13D has since been removed from the L07D/Dynavector 501 and remounted on to an SME20 with SME V arm.
With regard to the SP10mk3 I have heard Richarkrebs system many times over the past 30 years which evolved from a Goldmund Studio/ET2 to the SP10mk3/ET2 - I sold him a Madrigal Carnegie Model One for his ET2 years ago.
I also have to hand an SP10mk3/Technics EPA100 for extended listening.
So the answer to your question is yes and no. I have heard these TT's with the same arm/cartridge combinations many times, but not so in my current system as it is always evolving.
If I did not own the Final Audio, I do not know what I would buy as the nearest equivalent is the Kondo Ginga which is a derivative of the Final Audio, although the Kondo has less sophisticated speed control and a much smaller motor than my Final Audio.
http://app.audiogon.com/listings/turntables-turntable-ginga-kondo-ginga-2014-02-05-analog-italy-irwin-oh