Nice start Peter....
Obviously something is wrong with the Denon.....but the SME 30/12 puts in a solid performance....particularly for a belt drive which mostly find it hard to compete with the old Japanese 'super' DD models?
This should be a chance to see how the much vaunted big Micro Seikis like the SX/RX-5000 and SX/RX 8000 models compete?
Also Dover's Final Parthenon which he claims is 'spot-on' with the Timeline?
This would also be an opportunity for the 'modern' turntable manufacturers to display their credentials....particularly against the 30-40 year-old Japanese DDs?
How about the top Clearaudios, the Walker Proscenium, the VPIs, the Linn Sondek, the Continuum Caliburn, the Brinkmann, the Basis, the Feikert, the Verdier, the Kuzma, the TW-Acustic, the SOTA....and particularly...the new AirForce One?
And how about the modern DD turntables like the new VPI, the Wave Kinetics NVS, the Monaco Grand Prix?
I would also love to see how the old Idler/Rim Drives perform?
Like the Garrard 301 and 401, the Thorens, the Lenco and particularly the legendary EMT 927?
And then there's the new Idlers like the Saskia which reports excellent performance?
I know there is a lot more to a great turntable than keeping absolute and/or consistent speed 'under load'......but surely that needs to the 'a priori' fundamental?
If that 'objective' quality can not be delivered.....all the bells and whistles which some tables claim to contain.....seem slightly redundant?
Of course two problems exist in trying to add these tables to the DataBank.....
1. An owner/manufacturer needs to have or borrow a Timeline
2. They need to know how to video it and upload it to YouTube
Good luck in your quest..... |
Were the TT's hooked up to any kind of speed control device? |
My SME has an adjustable motor controller. The SP10 has a controller that is not adjustable. The Denon has no controller and I'm not sure about Halcro's Victor. |
Makes sense in that the table is actually playing a record, though w/ a speed strobe there is a spinning disc. This is certainly easier to make out though. |
Damn that Led Zeppelin IV album is warped. I would not play it without a periphery ring. Also, watching Halcro's videos, it's interesting how some audiophiles just drop the cartridge on the record. I lower my Delos as gently as I possibly can. Seems like a good practice to prolong the suspension's life. |
Also, watching Halcro's videos, it's interesting how some audiophiles just drop the cartridge on the record. Perhaps you should buy a tonearm with hydraulic action lifting and lowering...as all my six arms have? No human can lower the cartridge more gently that these.... :-) |
|
ALL direct-drive turntables have a "motor controller" of one form or another, built in to the servo circuit. I suppose it is possible that a DD turntable could benefit from a standard AC regenerator, like a PS Audio power source, but such a device is different in purpose from a dedicated tt motor controller. You can assume that the TT101 has such a one. For one thing, the TT101 has a DC motor; the PS inside the chassis converts AC into +/-12VDC and +5VDC outputs. The Denon has a 3-phase AC motor that is "controlled" by a feedback circuit. So, it's able to adjust its speed. (I don't know whether the DP45 has adjustable speed option on the control panel, but the more expensive models in that line-up do/did.) |
I wish my DP45 had speed adjustability. I would have tried to get it a bit more accurate before taking the video. |
Halcro,
Yes, something must be wrong with the Denon, though it actually sounds pretty
good. Thanks for posting the results of the Raven. It appears to be slightly slow.
One of the design differences with the SME is that the length of "free
belt" between the platter and motor pulley is much less on the SME. Both
tables appear to have heavy platters and robust motors. Is the Raven motor
controller adjustable?
You wrote somewhere that despite the superior speed performance of your
Victor that you do enjoy the Raven for its "musicality." Can you
actually hear a difference in speed between the two tables, or do other factors
like table/arm/cartridge differences make the speed differences too difficult to
single out? Do you hear differences in timing, drive, rhythm, clarity in transients,
etc? Which table do you prefer to listen to overall?
I don't know how many new videos will be added. I hope some are. I've heard of
various TimeLine results with the NVS, TechDas and SP10MK3, but owners may
be reluctant to share these results publicly. I'm particularly interested in results
from the Micros, the TechDas, the Saskia and some of the modern DD tables.
This test really just measure average speed accuracy. It does not tell us much
about what is happening to the platter at the moment of a large transient.
Perhaps some information can be learned from the quality and length of the
TimeLine dash on the wall and how solid and consistent it is. There is also the
issue of the weight of the TimeLine itself introducing a different load to the
system being tested. I've read that this would effect an open loop system on
some belt-drives more than the closed loop system on your Victor and other DD
tables. This is one of the primary criticisms I've read of this TimeLine device. |
Hi Peter,
One thing I noticed on a couple of your videos, as you had mentioned, the red line is sometimes shorter. Do you see this when watching it live? I suspect that the occasional blip in the red line on the video is due to the shutter speed of the video camera. Do you know if you are recording at 24 fps, 30, fps or 60 fps? If you can, try changing the shutter speed and see if the issue is gone. |
Hello Tony, Those were my thoughts also. I'm using an iPhone and I don't know what the fps rate is. I'll look into it. However, I returned the TimeLine to Albert Porter on Tuesday because I had recorded the various turntables around me. I don't really notice this effect when watching live. They just look like red laser dashes blinking along.
I'm sure in a more controlled setting with an excellent microphone and professional camera, one could perhaps even hear slight variations in speed on certain recordings over the video.
I'm just hoping other upload videos to add to this database. |
Perhaps you should buy a tonearm with hydraulic action lifting and lowering...as all my six arms have?
No human can lower the cartridge more gently that these.... :-) Halcro, Perhaps I wasn't clear in my post. I actually do have a tonearm with a dampened lowering mechanism (VPI JMW-Classic), but the cartridge still has a distance to travel once it's released. If you simply flip the lever (as I have seen some audiophiles do it regularly), the stylus will still hit the record surface with some force, albeit weaker, IMO too hard to ignore and repeat with every flip of the record. I release the mechanism very close to the record to minimize the strain on the suspension. I thought every audiophile adhered to this practice with lowering mechanisms. |
Actusreus,
I wouldn't judge all tonearm lifters by the VPI one.......? |
Hi Halcro,
What piece of music is playing in your Raven AC-2 video? |
Forthcoming is the Saskia and at least one unlikely vintage turntable. Of interest to me is how the turntables behave at the very start when the record is cued. It would be nice to see that in the videos, too. |
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 suspect that the occasional blip in the red line on the video is due to the shutter speed of the video camera. It IS a function of the shutter speed. In reality...the dash is the same length every time. |
Richard, thanks for this GOLDMUND info. I once owned the Studio way back. And I wondered why there wasn´t pitch control for that expensive deck. This explains it quite well, pitch control wasn´t needed at all. The music that is playing defines the speed stability. A very intelligent system, very sophisticated anyway. It would be interesting to see complicated music been played with the Studio and TimeLine test. Firstly, the flimsy suspension must be tamed/eliminated to make a proper test though. And finally, does the music really sound right ? |
The Raven has a 'stepped' motor controller. This means unfortunately...that there is no 'analogue' control of the speed. It goes up or down by 'fixed' increments. There is little doubt that the Raven could be made to run accurately with a different motor controller? Perhaps that could be an upcoming up-grade from Thomas? ......please :-) Do you hear differences in timing, drive, rhythm, clarity in transients,
etc? Which table do you prefer to listen to overall? That's a difficult question to answer Peter......... When I first acquired the TT-101......the differences to the Raven presentation were noticeable and preferable. There was deeper, more solid and controlled bass presentation together with a more coherent rhythm and 'drive' to the music. The high frequencies shimmered more and seemed clearer with greater extension....particularly of the harmonics? What this did for me however....was to set a benchmark against which I tried changes to the Raven....to bring me closer to the Victor presentation? The first changes were to the platter mat....which had been the Millennium Carbon Fiber sent with the turntable and recommended by Thomas Woschnick. It has two sides but neither one produced the linearity of the Victor. I then tried the Rega felt mat, the Victor rubber mats (2 types) as well as the Victor pigskin mat. It was only when I placed the record directly on the copper platter surface that the performance began to match the Victor. A heavy record clamp made it so much better...... I then attempted to achieve the best speed consistency as shown by the Timeline. I tried it with one, two and three motors....and achieved the best consistency with two diametrically opposed motors. This also has the benefit of greater belt/platter contact area as well as balancing eccentric loads on the spindle. So the 'sound' of my Raven AC-2 has now been carefully 'matched' to the TT-101 although the TT-101 is still rather special to listen to.... When I switch back to the Raven.....it takes no time at all to relax and enjoy the musical presentation.....I don't 'miss' the Victor. But making improvements in any part of our systems does not negate the enjoyment we derived before those improvements? I never think back to my first Rega Planar 3 with Kebschull preamp and Perraux PM-1850 power amp....and think...."boy, what I was missing?". I derived the same enjoyment then as I do now.... This test really just measure average speed accuracy. It does not tell us much about what is happening to the platter at the moment of a large transient. I disagree. I believe the Timeline tells us more about the performance of a turntable under 'load' than any device we have previously had. The 'naysayers' I suspect.....are those who haven't seen the Timeline in action, are afraid that their turntables won't pass the Timeline test...or know that their turntables won't pass the Timeline test? |
What piece of music is playing in your Raven AC-2 video? Boy....I have had more response to this musical piece than to any of my previous posts :-) It is La FoliaBetter be quick if everyone who has contacted me orders one? :-) It really has 'killer' sonics as well as being just magical to listen to.... |
It would be nice to see that in the videos, too. You can see that with all three arms on my first TT-101 video....and you can also see and hear it on my second TT-101 video. |
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. Impossible to say this without actually testing it with the Timeline I would venture....? |
Didn't Goldmund source their dd motors from JVC ?
The Studio had quite the funky plinth, pretty flimsy if I remember correctly, what was Lerne thinking about ? |
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.
Provided the controller is properly adjusted, it will rotate at the correct average speed. This is the beauty of a synchronous motor. In other words, I would be surprised if a properly designed and adjusted DD TT using a synchronous motor failed the timeline test. This assumes a stable reference frequency, quartz.
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. 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.
For a DD drive, it has a reasonably high inertia platter but this was not enough to "push thru" these load changes.
The only way for the motor to slow down, on a continuous basis, if it's field is rotating at the correct speed, is for a massive retardation torque to be applied. This would be extremely violent as the rotor rode backwards over the poles.
Wrap a properly designed servo around this type of motor and the phase angle change with load is reduced. |
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) DDs ( comparable products in terms of market positioning ) have significantly higher inertia - 2-3 times higher. Of course the Micros 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 TTs. 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. |
Thanks for the great post, Richard. I think of a 3-phase AC synchronous motor is a cousin to a DC motor. In fact, the Victor TT101 does make +/-12VDC in its PS to supply its motor. Likewise, I thought the SP10s used DC motors. But the Denon uses a 3-phase AC motor. Whether or not all of that is correct is not my point or question. What I do wonder about are the "modern" DD turntables, such as the NVS, the Beat, and the new VPI, among others. Their adverts all claim that they've avoided the nasty [sic] effects of a servo by using a 3-phase AC synchronous motor that holds speed by virtue of the mechanism you've just described, sans any servo. At least 2 of those 3 mentioned use fairly massive platters, so it seems to me they are able to give up the servo mechanism by virtue of the mass effect afforded by their platters, much as is the case for some of the better belt-drives. But still, the platter must first slow enough to trigger the speed up commanded by the AC synchronicity. Do you have any thoughts on this?
Thanks. |
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.
|
Lew
The Beat appears to uses electromagnetic drag to "pre load" the motor. Moving the rotor back in phase relative to the rotating field. I am not sure about the other TTs mentioned. The theory being that this artificial torque demand is significantly higher than any seen due to stylus drag. It seems like an elegant solution. The question is of course how does it sound? I do know that we are very sensitive to micro pitch changes and that stylus drag is large. The choice of open loop or closed loop speed control in ones TT is a personal one and we all make that choice with open ears and hopefully open minds. |
Excellent Post from Dover.
Unfortunately no Audiophile will understand it :-) |
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 ( thats 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. |
Very interesting thread Peter. Thanks for getting it going. I'll volunteer my Grand Prix Monaco to be a test subject, as soon as I can barrow Albert's timeline...
The Grand Prix claims highly accurate speed control (from their web site):
"DSP Signal Processing / Active Feedback Loop Technology:
Our speed control features a CPU utilizing a Digital Signal Processor that interrogates and maintains the speed of the platter thousands of times each revolution and thereby ensures frequency accuracy and distortion free playback that is simply not possible with conventional types of drive systems. A highly accurate test procedure has demonstrated the speed error to be an extremely low .002%! Speed accuracy equals frequency accuracy, which means there is virtually no distortion on playback."
Peter, one thought on your SME, have you ever cleaned the motor pulley (and sub platter) and then flipped the belt over? I used to do this with my SME 20/2 every 9-12 months and it did seem to sound better...(that is unless you used a new belt for the test)...then I'd replace the belt every 18-24 months... |
Thanks Jfrech. I used to clean the belt on my SME Model 10 about once a year. I've just ordered two new belts for my 30/12 which was new in March 2012. I'll clean the belt I have in the next day or two and see if I notice a difference. I sent the TimeLine back to Albert. I just can't see spending $400 on a new one.
Your Grand Prix will be a good addition to the database. Thanks. |
HF Dover
You appear to have invented a whole new type of motor. One where the rotor follows the rotating field with zero phase lag.
Please explain to us all how such a motor produces any torque.
Also one which "Instantly" draws more current and supplies more torque.
Please explain to us how it senses the need for more torque.
Caution needs to be exercised when quoting manufacturers advertisements. |
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. |
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. |
"The Beat [like every other direct-drive turntable] has only one moving part, the bearing." The ad copy is correct; however the inference that this quality is exclusive to the Beat is exaggerated, to say the least. But I really really like the Beat. I think it may be the best buy in high end turntables, if $24K is a "buy", but I can live without the hype.
I think I mentioned this above; the Denon DP80 and other models use a genuine 3-phase AC synch motor. But they also built in quartz-referenced servo control. The servo can be defeated on the front panel. It would be interesting to compare its performance with vs without the servo engaged, but you might fairly say that the platter is not massive enough to give the momentum needed for the a non-servo dd to perform really well, even with an AC synch motor.
But isn't the argument that a massive platter and no servo is superior to a lower inertia platter WITH servo just an analog of an old argument among belt-drive aficionados, where the two sides argue over massive platter/weak motor vs lighter platter/torque-y motor? The more things change, the more they stay the same. Massive platters tend to "spread out" any speed error over time. Those who like them say that this is good. Those who don't don't.
And now we have "Mag-drive", because the buying public have been taught for 30 years that direct-drive is a dirty word. |
Motivated from Peter I tried to make my first Video ever :-) The first one I made in the evening, the Laser was seen very good but it was too dull overall, so I started a new one in daylight.The file is compressed from optical quality but I think it is ok. The Laser is seen in reality below 2 letters (the "CK") in the name Fruhbeck. I stopped after 2 minutes, I wanted to avoid the make the file too huge but the Laser was still below these 2 letters after 5 minutes. That's ok I think :-) The most other turntables I checked with that unit were out of specs after 5 seconds Seiki RX5000 |
I thought this thread was to be a database of timeline checked turntables - not a guessing session. So did I
.. There are many other Threads where you can proclaim the superiority of your choice of turntable
. Instead of the subjective, emotive and mostly unproven claims often made in those Mine is Bigger than Yours contests
this Thread was begun purely to demonstrate objectively (via the Timeline)
..the actual performance of turntables under load. Videos and comments/observations about those videos are most welcome. We have heard continually over the years
.the claims of superiority for the heavy-mass belt-drive turntables like the Micro Seikis and Dovers Final Parthenon and I have no reason to doubt these
. We know also that both Dover and Syntax have access to a Timeline and we have seen evidence of Syntaxs abilities with photography and computer up-loads
..so it puzzles me slightly that neither of these individuals appears brave enough to simply post his turntable's performances with the Timeline on this Thread? |
Halcro
For consistency, as you have done, it may be advisable for people posting videos to show say 1 minute of stylus raised followed by a time with it lowered playing some robust music. Something like the lovely piece you played.
While having the stylus raised presents no load, it would give us at least a guide of how the TT would perform when tracking very lightly modulated grooves followed by heavily modulated ones. |
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. |
Slightly, or a lot off topic! Just wondering, as very few have the timeline but most have a smart phone and a test tone record, if the Feickert app might be more readily accessible. See this Data Base.
http://www.stereo.net.au/forums/index.php?/topic/49224-turntable-speed/?hl=olderas#entry889328
It doesn't have the changing modulation variation that a piece of music has, but does have stylus drag, not quite the same thing, but a starting point. Seems like most of the TT's tested are absolutely fine with the timeline, but what about minor variations in speed resulting in small frequency shifts while maintaining overall 33 1/3 rotational speed? |
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 testHigh torque AC synchronous motor with decent power supply, 22kg Platter, silk thread and decent record clamp. No servos required. Anyone up for the challenge... |
Richardkrebs, For consistency, as you have done..... This would be ideal in my opinion.... Neither Peter nor Syntax have shown the effects of the stylus ON and OFF the record with their belt-drive turntables... I showed the effects of the stylus 'leaving' the record with the Raven AC-2....and it can be seen that the speed is stable in that situation whilst slightly 'slow' under load. There are many on this Forum who claim that a belt-drive turntable with a high-mass platter and well regulated motor....will not be subjected to 'stylus drag'. I am still skeptical about this....and we have seen no evidence with the Timeline that this is possible? Hopefully someone will demonstrate such a phenomena? |
Dinster, The whole idea of the "Timeline test", so far as it goes, is that it does indeed give you some notion of the instantaneous speed stability, as opposed to average speed accuracy, of a turntable. The time interval measured is akin to the time between laser flashes on your observational starting point. If speed deviates between flashes, such that the flash appears to move in either direction from start, it indicates that in that time interval the speed has deviated, up or down from 33.333. (I don't own a Timeline. I think there are 4 lasers built into it at 90 degree intervals around the pillar, but I could be wrong. 33.333 rpm corresponds to one rotation every ~1.8 seconds. You can figure out the rest.) |
Well, I think, we all do us a favor to say, the Timeline is just "another" strobe and has its own faults (which is, of course, wrong). It is super precise, or better said, the best tool today. It measures the REAL speed when the diamond is in the groove. The force (VTF) is remarkable.
The majority of turntables run quite well when the Diamond is Not in the groove, but honestly, who is interested in THAT????
Performance is with tone, not without.
When I did the tests with adjustable motors while playing, and they run out of specs (drift) and then I made the corrections, the difference in sonics is easy to hear. Deeper soundstage, no smeared cynics and much better modulated details.
Today we have two "religions":
The unit "does something", Product A has better bass, Product B is analytic and needs this or that cartridge/Arm for compensation or endless "updates" because the designer is unable to do something right, some call it Prat
or
the "Religion" is based on software reproduction. The emotion is coming from the recording, the purest form of a sonic truth...
"Religion 1" is"keep the business alive
"Religion 2" is "done right" |
Halcro,
I, for one, do not claim that a belt drive turntable with heavy platter is not subject to stylus drag. I thought I made the point quite obvious in my earlier comments. One can set the speed of the SME with no stylus in the groove. Then when the stylus is playing, the speed slows down slightly. In other words, the SME 30/12 IS susceptible to stylus drag. No one has denied this fact. I would make another video showing this with arm up and arm down, but I returned the Timeline to its owner.
I want the speed to be accurate when I listen to music with one cartridge in one tonearm playing one record. Therefore, I set the speed when the stylus is in the groove, and you see the results of that speed in my video with the TimeLine. It is 0.003% slow according to Tonywinsc who did the calculations in that other thread. The KAB is also designed to be set with music playing. In fact, Sutherland markets this as an advantage to his device, that it can be used while music is playing to check the speed.
One can also clearly see that your Victor with the three tonearms is also slightly slow because the Timeline dash does not stay centered on the blue tack. It in fact drifts to the left by about 3/8th of an inch.
There is no denying that a high torque DD table will not loose as much speed as a BD table with a rubber belt when a needle is dropped in the groove. Therefore, my recommendation is to set the speed while music is playing. |
Well, the Timeline is a strobe; but I do not say that with disdain. It is just a fact. It is a very precise strobe with reported 0.0002% accuracy. As with any measurement device it must be used properly. The results must be interpreted properly as well. I know it is too late in some cases; but I propose that when using the timeline, 9 minutes minimum should be the measurement cycle. That is just short of 1000 rotations of the platter. If turntable speed accuracy is in the 0.003% range like Peter's SME deck, then that will show an error of 0.03 rotations. For example, 0.03 rotations is 10.8 degrees. If the laser line is projected out to a wall 18" away, then the drift after 1000 rotations will be 3.4". Measuring 3.4" vs. less than 0.5" will reduce the affect of measurement error and give more accurate speed measurement results. |
