Dear Raul,
I know about the theoretical discussions you are referring to and so many people in this business. Regarding practical issues when it comes to listening it is not about the turntable adding something or not! This is not my point. You may bring down a turntable to neutrality and it sounds shitty or let's say clinical cold.I have heard so many totally neutral turntables and the owners were proud of their sound. Fine. The real art in turntable building or let's say also in dealing with different concepts/drives and comparing those is based on the ability of the turntable to transport the signal in an uncoloured and undistorted way - which does not mean that all turntables doing this are equal or coming with the same sonic footprint (!).
When you ever had the chance listening to an EMT 927 or to a very good DD or to a brillant belt concept ( lets take the Continuum as an example ), and I am sure you can, you will agree that although they are playing music in a wonderful way, they offer some differences. From my point of view it is the biggest missjudgement to put these differences (dynamics, musicality, bass grounding etc.) only to artifical add ons which should not be there.
Some people don't like the sound of idler wheels.I believe it is good listening to a well adjusted idler wheel. I have experienced the differences also of various prominent brands and models, good sounding and not good sounding idler wheels. An idler wheel can be very dynamically. Is this generally coloration or distortion in your definition? Or are you referring to not well adjusted tables - which is different.
If for example a SME is an absolutely neutral turntable in your or other people' s experience and you regard the sound it makes as a benchmark "in your undistorted world" perfect! For me it is not benchmark! But this is up to the preferences one has. I am sure we both must and will live with our different way of approaching practical listening experiences. What I am saying is: Too much in this forum is only and more or less theroretical based. Maybe we can bring some colour into it :-)
best @ fun only
best @ fun only |
Dear Thuchan: Please read this about " neutral ", this add more sense to what I posted and telling you that I'm not alone, btw your dear friend Syntax agree too:
++++ " Takeda San says, "I was always frustrated by modern cartridges -- including my own designs in the past -- because they always sounded clean and nice but failed to present a very important element of music. What was missing was the linearity of dynamics. Many cartridges can produce clean sound but the sound is only one element of music. They fail to present the flow of music. Listeners may not realize this if they are not familiar with music that requires a wide dynamic range and delicate gradations within it. Large orchestral works and certain piano recordings are typical examples. I also wanted my Standard to be tonally as neutral as possible. Many cartridges have some degree of coloration to make them sound appealing. I didn't want to do that with the Standard."
of course that you don't have to agree with the " neutral/accurate " subject as Takeda San said: ++ " have some degree of coloration to make them sound appealing. " ++, if you are on this side good for you because that's what you like it. Neutral/accurate is in the other side of " I like it ", neutral/accurate is the way " thigs " must be it does not matters if we like it or not.
IMHO, if you own a good audio system and you don't like neutral/accurate performances then that " good " system has one or several problems else where, or your ears or both.
Re-read Frogman's post and if you have time my post too and some Syntax ones on the subject on other threads.
Regards and enjoy the music,
R. |
To resolve this problem some BD makers use optical feedback - to measure the platter speed and adjust the motor speed "in time". I think the new "Micro Seiki" spaceship is equipped with such a speed management system. |
No variable ac line = no variation in motor control = better stability.
Problem for many dd turntables IMHO is the fact that the motor MUST control (by nature here ..) the platter very direct with minimum delay.
Thus the use of a heavy platter with high inertia is counterproductive to direct drive.
IMHO however, high mass platter made with some insight in energy transfer and damping have inevitable positive effect on analog reproduction.
A DD with high mass platter "looks" at a similar problem as a BD.
aBoth have a kind of "overhang" in their reaction between motor speed adjustment/correction and reaction by the platter. |
We have pretty good reports from TW Acustic owners, who have changed the standard PSU with battery motor control unit from Raven Black Night. |
Gosh, what is left to say or think after that?
I agree that direct-drive turntables can be highly "colored", in a bad way. I also completely disagree; speed stability is the sine qua non of a turntable, no matter the drive system. "Sound quality", if by that term you mean the degree to which the sound emanating from the speakers can be made to emulate "real life" does depend very much upon speed stability. From that comes rhythm. From rhythm comes verisimilitude, in part.
Sure, a tt with excellent speed stability can sound bad for other reasons.
Why is a battery power supply, per se, likely to be superior to all other approaches to power supply? |
In a way we should think different, because speed stability is one side, sound quality has absolutely nothing to do with it and a turntable which creates "something" is also a total different animal (Raul is absolutely right on that topic).
When you want speed stability, a direct drive has advantages because it always is in connection with the used voltage, it always correct its speed during play (accelerate-hold-reduce-accelerate-hold-reduce and so on).
Direct drives are good for those who believe, that this has something to do with superior sound quality. A listened to some really good designs and I know, this has absolutely no influence. A direct drive TT can sound thin, lifeless and boring. Maybe there are exceptions ...
A belt drive TT Designer has to solve some problems, see Belt quality for example. Most aren't even able to solve this properly, then we can't expect that those are able to design a proper speed control. and this story goes on and on.
When someone is reading this and has no time to read the former 3 sites
- go for any suspended Basis turntable with Basis Controller or Walker Controller
or
- ask Sorasound for an Amazon turntable, they have a Battery power supply.
That one is good.
- or SME 20/30
Others produce "something" what someone likes or not. Discussions about "this" are endless because one prefers black, white, heavy, expensive, rare, PRaT, catholic or islamic soundstage and so on. These "problems" were all solved years ago, unfortunately engineering is no longer part of High End Analog. It is replaced with "I like it". Analog is a following of steps done right. |
Dear Tony, Cogging is indeed a problem with motors, but what I described would not be strictly due to cogging. Mostly it is due to the servo hunting when its feedback loop is screwed up by the lack of a platter mass or in the other extreme, too much platter mass. Cogging will always be there and is an inherent property of the motor; some are less prone to cogging than others. |
Tony you may find Dovers record player interesting ,surely a heavy weight contender for ultra sophisticated speed control.
Henry if my memory is correct I seam to think that I read somewhere TW Acustics stated their motor speed control was designed to perform like a vintage direct drive. |
H Lewm, yes, you are correct. That is called cogging. I'm sure BD motors do it too if they are unloaded. You just can't see it with your eyes because they spin too fast. That is what I was saying before that designers use mass as a damper- mass damping. All motors have some level of cogging, or ripple. Even your car engine has it as each piston fires. The flywheel smoothes out those ripples just as the tt platter smoothes out the ripples from the motor. The typical tt specs showing Wow&Flutter below 0.03% shows how well these massive platters are doing their job. btw, the more poles that a motor has, the smaller the ripples. I notice some of these expensive tables have quite sophisticated motors. Caveat Emptor always applies, but I think you are getting what you pay for in some of these expensive motor designs. |
Tony,
The TT-101 does in fact reach its correct speed within a revolution as seen on the Timeline.
The actual specification states that 'starting time' is within 0.6sec.
Starting torque: 1.2Kg/cm
Speed deviation: 0.002%
Drift: 0.0004%
There appears to be some confusion about the functioning of the quartz locked positive and negative servo control of the TT-101?
It does not compensate for a speed deviation over a complete 'revolution' or series of 'revolutions'.
In other words......if there is a slowing down due to stylus drag........the servo does NOT speed up to 'compensate' for that 'lost' time and thus keep an 'average' continuum?
The servo does not know how many revolutions it is completing in any listening session....nor does it care.
It cares only about 'instantaneous' micro speed control.
What this means, is that if there were a slow-down due to stylus drag at any point of a record's playing cycle......that error would be permanently imprinted on the Timeline 'Blutak' marker on the wall. And any extra deviations would be accumulative so that the laser line of the Timeline would 'drift' further to the left with every revolution.
This you will appreciate if you ever use your own Timeline on your own turntable?
It truly puts into perspective the performance of the TT-101 which you have witnessed on the video? |
Thanks Dover, Chris, Thuchan & Banquo,
I appreciate your encouragement :^)...... John Gielgud (blush).
Dover is from New Zealand.....so of course I sound like an orator to him:^)
I was going to follow up with a video of the Raven AC-3 under test.......but I don't think it's fair?
Everyone can test his own turntable once armed with the Timeline.
There will be some shocks? |
Tony, What I meant was that in direct-drive turntables, the motor, the drive system (aka servo), and the platter together form a closed system. So indeed the mass of the platter has everything to do with it. If you don't see what I mean, try removing the platter from a direct-drive turntable. The result will be a pronounced herky-jerky motion as the servo goes searching for its proper load. If you dramatically increase the mass of the platter (yes, "m"), the servo can get similarly screwy, slow to correct for off-speed moments, but it is less easy to see. It is the servo that tells the motor "how much acceleration is enough" to get back to equilibrium.
None of this is to contradict what you say about LPs with off-center holes (i.e., most of them). That's a big, important, and separate issue. |
Dear Thuchan: I think you have a wrong concept of neutrality/accuracy on audio devices.
IMHO any audio device should let pass the LP/cartridge signal " untouched " and this means with accuracy/neutrality: IF THINGS ARE THAT THE THE TRACKS ON THAT LP ARE WARM/COLD/LIVELY/DYNAMICS/BRIGHT/DULL/DARK/ AND THE LIKE WHAT SUPPOSE THAT ANY AUDIO DEVICE/AUDIO LINK IN THE WHOLE AUDIO SYSTEM CHAIN MUST DO IS TO PASS ALL THOSE LP MUSIC RECORDED CHARACTERISTICS WITH NO ADDED DISTORTIONS/COLORATIONS BUT WITH ACCURACY/NEUTRALITY.
ALL THOSE MUSIC RECORDED CHARACTERISTICS came/comes in the LP and in theory are not part or be/bee need development by the audio links: what you hear must be what is in the recording: adding NOTHING!!!!! or do you think that your system is so good that can improve what comes in the recording?, no way my friend no system can do it!
Do you think that all those additional " stuff " in your Micro Seiki improves the sound?, NO only change and add different distortions with no real improvement.
Regards and enjoy the music,
R. |
Dear Halcro: I could listen to you reading the phone book and find it gripping. You speak with a deliberateness and cadence of several philosophy professors I know. Put differently, you're the John Gielgud of the audio world.
More videos! |
Ha Ha Ha - yes sure dialect. Its wonderful either way Henry :^)
And music is the common language here.
ACCENT vs DIALECT
NEUTRALITY vs COLORATIONS
What a great hobby |
Halcro - great demo, no accent.
I agree with Lewm on neutrality, different for different folks. We all know if we have a preamp with a dip at 3k say and we listen to it for a long enough, the ear/brain adjusts, and when you try something else that is neutral you think it has a peak at 3k.
I would suggest that speed and timing are far more important, as once you have lost the timing you cant recreate it in your head.
Re Wave Kinteics NVS that started this thread - did anyone notice that that original thread has disappeared. Do manufacturers get bad press/comments pulled from the forum ?? |
The mass of the platter has nothing to do with speed control other than it is the "m" in the equation, F=ma or T=J(Omega). The motor controls the speed. Its that simple. As shown by the equation, more mass means the motor must generate more torque to provide the same acceleration. How much acceleration is enough? Well, it depends on how well the designer wants to hold the exact rotational speed under dynamic conditions. I stated as a rule of thumb based on my knowledge and experience designing dynamic systems, (not turntables) that a tt motor should be able to accelerate the platter from 0 rev/s to 0.5556 rev/s within the first rotation. Some motors may be able to do better than that, but if it takes a motor more than one rotation to get the platter up to speed, then I think it might lack sufficient torque to maintain a stable speed. I could be wrong here, I've never designed a tt myself. But to carry it further, the motor is designed to spin at a certain speed. That control system for the motor can be as simple as being clocked to the 60Hz sine wave of the AC power to a very sophisticated electronic servo feedback control system. However it is done, the resolution and rate of response of this control system results in the level of stability of the platter speed. The system design dictates how much speed error can occur before it corrects it and how fast it can correct the speed. At this point I could get into the impact of an underdamped or over damped system, but the point is the tt designer must come up with a system that includes the motor torque, speed, resolution of the control loop, platter inertia.
I might be wrong here, but I have observed that DD turntables tend to have lower mass platters versus later BD tables. I'm guessing that the torque available from DD motors is less than for BD considering BD motors get a mechanical advantage from the pulleys. Higher mass platters offer a nice stable sink for the vinyl record to minimize vibrations. The added inertia of high mass platters is probably more of a problem for tt designers in terms of speed control- just because it requires more torque from the motor.
I'm starting to think the rhythm and pace might be linked more to the tonearm and stylus. The runout of the vinyl record, as I showed before, has more impact on Wow than does the tt. But the swaying of the tonearm, which is part of the Wow problem must also influence the tempo of the music I think. Couldn't the side to side movement of the stylus in the groove alter the tempo? Is that what tonearm damping is all about? I don't have damping. Does anyone have experience that says tonearm damping improves the tempo of the music? |
Henry , I think he meant your English dialect |
Your accent doesn't come through in the posts here. Accent??........I have an accent??! |
Tony, I don't quite see your "one revolution" hypothesis. The platter once in play never comes to a complete halt. I think the point is that the motor needs to have "enough" torque to keep speed stable. And the definition of "enough torque" is related to inertial mass of the platter and servo design. In bd turntables, the belt/thread/tape is an added factor in the equation. In idlers it's the idler drive system. |
Excellent video production Henry ! Your accent doesn't come through in the posts here. :^)
My American and UK co-workers tell me Canadians have strong accents too but I don't believe them - eh ?
I think this Utube stuff opens opportunities here for everyone and the gear.
Would love to see more of you out there with your wonderful gear.
Thuchan - how about a video demonstrating your favourite audio toy – you could speak Japanese too.
Wonder what Raul sounds like?
How about a 3 minute utube video Raul demonstrating your tonearm features to us ?
Technology awaits. All in fun
Frogman - I agree with you.
Tony – great info
Cheers Chris |
I am with you in this dilemma, which is why I hate the word "neutral" when used to describe an audio product. It can have any meaning that the user wishes it to have. One meaningful way to use it would be to say that "I have heard this or that LP many times in my own system using a wide variety of turntables, tonearms, and cartridges, and I find that this turntable/tonearm/cartridge seems to add less (or more) to the basic sound on this LP than does that turntable/tonearm/cartridge". Or something like that. |
"Mosin, as inertia is directly related to mass and friction.....are you saying that heavy platters have inherently greater inertia than light ones?"
What I'm saying is that sheer mass is less effective when it is capriciously used than when it is purposefully assigned to achieve an optimum moment of inertia. As far as mass on a platter, I feel that its benefit as an isolation component is another key reason to use it.
Of course, there are more ways than one to skin the proverbial cat, so lighter platters may also work with some designs. I work solely in the arena of idler drives, so that is where I spend my time looking at such things. Recipes vary, but the performance depends on the entity as a whole, and not just a single part because every part is critical to the outcome. Any shortcut is a compromise. At least, that's what I have come to believe. |
Dear Lewm,
ok didn't jump so far. Maybe I have a different / not typical understanding of footprint or better let's say character or personality of a turntable.
I know some audio gurus carry the philosophy of neutrality around the world, which should mean, the more neutral a turntable is the better for the reproduction. In their sense it is absolutely necessary that a turntable should not become musical - but neutral. A neutral turnable cannot be musical, warm or dynamical, or lively. It is and has to be just neutral. Everything else is coloration or distortion. Am I right? Okay. In this understanding I am happy to live with coloration & distortion - and I don't need to jump.
best @ fun only |
Correct speed with 500 arms? That is not a helpful statement since we don't know what the definition of "correct speed" is. What matters is to reduce the effect of a single stylus to below audibility. I don't think that anyone has been able to quantify what that specification is. But there is ample evidence that extremely small speed perturbations are audible.
It is is misnomer to assume that a massive platter fixes the stylus drag issue. A heavy platter results in a smaller perturbation spread over a longer period of time. A light platter will slow more but will recover more quickly. A heavy platter changes the problem but does nothing to eliminate it. I think that most people prefer the shallow but longer perturbation from a heavy platter, but ultimately it's a matter of taste, not superior stability. |
I found an article online about the Nak. Very interesting tt. The author had an excerpt from an interview with the designer. He substantiates my point exactly. He says vinyl record runout is the elephant in the room that tt designers ignore. As for inertia: Torque= J*omega, which is the angular term for F=ma. The tt motor provides the torque and the platter bearing and stylus apply a counter torque. The inertia of the platter determines the rate of change in speed (deceleration). Say for example the motor is uncoupled from the platter. The platter is spinning at 33.33 rpm. (ignore bearing friction for a moment) Now drop the stylus onto the record. A 20 kg platter is going to decelerate at a lower rate, for example, than a 2 kg platter.
Now let's hook the motor back up to our platter. The motor is either clocked to the 60Hz line frequency or is feedback servo controlled. So it holds the platter at 33.33 rpm. Any perturbation in the platter speed causes the torque output of the motor to change in order to restore 33.33 rpm. The motor could do it's job regardless of the amount of inertia in the platter. The stability of the platter speed is based on the control loop and torque of the motor combined with the system inertia. That means the designer has to couple a motor and platter as a system. The platter is designed to be a mass damper. We use mass dampers in dynamic systems. We use mass to tune System Natural Frequencies and keep them out of certain operating ranges. A bigger platter requires a higher torque motor in order to be stable. Perhaps the youtube example is a tt design with an undersized motor. I would say as a rule of thumb, the motor in a tt should be able to accelerate the platter up to speed within one rotation. To me that would indicate that the motor has sufficient torque to maintain a stable speed. btw- I just checked my tt and it is up to speed within one rotation. |
Halcro, as I posted on 11/16 the SP-10 Mk2 manual states that table will maintain correct speed if up to 500 arms could be lowered simultaneously while tracking at 2 g. Even with an error range of 10%, it should be correct with up to 450 arms! From that, your three arm test was not much of a challenge. ;-)
However I suppose the problem with the Technics statement is the table could "maintain correct speed" with up to 1K gram weight applied. That could be different from not maintaining speed at the moment the weight was applied. In other words, should one allow say one revolution to correct the speed with this weight? That would be a big difference in sonic terms.
So if I'm understanding this, your laser mark should be measured precisely at the moment each stylus is lowered onto the record with no time interval to allow your table to correct for the added drag. |
Dear Thuchan, Please do not jump, but isn't the answer to your question obvious? If the 3 tt's sound different, then they are introducing different "colorations". Or possibly one is "neutral" and the other two are introducing colorations. No matter how you say it, these colorations amount to distortion in one form or another. I would also say that it does not matter, as long as any of them can make you feel you are at a live event, or even if they make you feel alive. How about the Continuum, which you don't mention? |
well said Frogman, but I am not pairing sonic footprint and neutrality. Sonic Footprint in my understanding is that you recognise the turntable's abiliy in producing fine music. Just take the EMT R80 (927) as an example. Agree completly that Precision Control allows musicality. I for myself need both!
Some people argue that a turntable should just reproduce which is a funny statement. A Linn Lp 12 and some of the smaller new Thorens tables e.g. also reproduce - but with what kind of result. Of course some people may like it. good. Distortion is a wide field and I know someone in this community who loves the term.
In my understanding sonic footprint is not the result of distortions at all. The Nakamichi, or the EMT as well as the Micros do have a sonic footprint which is different. Does this mean I am surrounded by distortions, God beware. I would jump from the bridge...
best @ fun only |
Thuchan, I reluctantly admit to being a "neutrality apostle". But I am reluctant only because, IMO, the term neutrality is usually misunderstood. In your comment you pair the term neutrality with sonic-footprint. From my vantage point, sonic footprint is, by definition, usually the result of distortions. Neutrality (or however close a component gets to it) is a measure of musicality. In other words, a component that is truly musical IS closer to neutral. "Precision control" allows musicality.
Regards. |
Thanks, Tony, for introducing some science to the foregoing discussion. I know I am going to sound like one of Syntax's "fanboys", but I have been listening to my Technics SP10 Mk3 for the first time in extensive sessions over this past weekend. And I am astounded by the rhythm and drive this table can impart to music on LPs with which I am very familiar. Try "Art Pepper + Eleven", which contains just about every bebop rhythm one can imagine. There were tears in my eyes, literally. Yes, Tony, the Mk3 can bring its 21-lb platter up to speed in one rotation, probably sooner. I have been arguing this stuff on a theoretical basis; now I am a true believer. |
Henry,
you made a good point with the Timeline & the Nakamichi. The red signal keeps stable even when the needle runs down on the record. Ths is an advantage of the DD design (and I have to correct myself - no manual speed correction is necessary on all my TTs).
Tonywinsc,
if we start a competion by using a stopwatch I might win with the EMT ;-)
Frogman,
you are right, precision control is the one thing but musicality and a sonic footprint is the other one. Therefore I find it hard always following the neutrality apostles in our community - but there are not so many in this thread. Am I right?
best @ fun only |
Keep in mind that the effect of the vinyl record runout is worse at the inner groove. As the needle is further out from the spindle the radius of the runout is proportionally smaller so Wow will be less at the outer groove of the record. So effectively another problematic issue when playing the inner grooves of records. Does anyone notice a rhythm/timing difference in the music from the outer to inner tracks? |
It will show that the designer used a motor with sufficient torque to maintain a stable speed. |
Tonywinsc,
Your explanation makes a lot of sense to me....especially with my experiences with DD turntables compared to belt drive.
I'll try your experiment with the one revolution......although I'm not quite sure what it proves? |
Halcro, another way to do it is with a stopwatch if you are fast enough. The motor should be able to accelerate the platter from 0 to 33.33 rpm in less than 3.6 seconds. So you could start the laser then start the motor and stopwatch and time it until the laser spot stops moving. |
While there is tremendous value in technical explanations for some of the perceived problems with vinyl playback, I think it is important to remember that those possible explanations are incomplete, and don't fully address the fact that what we are ultimately concerning ourselves with is an impossibly complex and fragile thing: the FEELING in music. Small speed stability problems that affect the perceived feeling of the music, wether caused by run-out errors or rotational speed error, are probably beyond the capability of any known measuring system.
I have (like all of us posting on this thread) struggled to make my
expensive belt-drive turntable as speed-stable as possible. Thread drive and a motor controller have improved the situation to a barely acceptable point. I say barely acceptable because I can still hear problems compared to the rock solid stability, and fabulous swagger that live music can have. In addition, the very same LP that has no perceived run-out issues when I use thread drive, will sound speed unstable when played using the rubber belt. This, in spite of my strobe showing that the speed should be rock solid. NOT! |
Perfekt Henry!
What is the name of the red lamp fixed in the wall?
best @ fun only |
Halcro, can you turn on the laser with the platter stopped and then start the platter? See if the speed is stable within one rotation. It is a bit difficult. The best way to see it would be with instrumentation and a plotter. |
Chris, Your wish is my command :-) Please forgive the amateurish state of the movie but it was taken on my iphone4.....my first film..... and my first upload to utube! TT-101 |
I found an article online about the Nak. Very interesting tt. The author had an excerpt from an interview with the designer. He substantiates my point exactly. He says vinyl record runout is the elephant in the room that tt designers ignore. As for inertia: Torque= J*omega, which is the angular term for F=ma. The tt motor provides the torque and the platter bearing and stylus apply a counter torque. The inertia of the platter determines the rate of change in speed (deceleration). Say for example the motor is uncoupled from the platter. The platter is spinning at 33.33 rpm. (ignore bearing friction for a moment) Now drop the stylus onto the record. A 20 kg platter is going to decelerate at a lower rate, for example, than a 2 kg platter.
Now let's hook the motor back up to our platter. The motor is either clocked to the 60Hz line frequency or is feedback servo controlled. So it holds the platter at 33.33 rpm. Any perturbation in the platter speed causes the torque output of the motor to change in order to restore 33.33 rpm. The motor could do it's job regardless of the amount of inertia in the platter. The stability of the platter speed is based on the control loop and torque of the motor combined with the system inertia. That means the designer has to couple a motor and platter as a system. The platter is designed to be a mass damper. We use mass dampers in dynamic systems. We use mass to tune System Natural Frequencies and keep them out of certain operating ranges. A bigger platter requires a higher torque motor in order to be stable. Perhaps the youtube example is a tt design with an undersized motor. I would say as a rule of thumb, the motor in a tt should be able to accelerate the platter up to speed within one rotation. To me that would indicate that the motor has sufficient torque to maintain a stable speed. btw- I just checked my tt and it is up to speed within one rotation. |
Henry - I want to see a youtube of the 3 cartridges lowered onto the record at the same time. :>) |
My point is that inertia has to be addressed at the outset of a turntable's design, and that electronic speed control merely augments it. Mosin, as inertia is directly related to mass and friction.....are you saying that heavy platters have inherently greater inertia than light ones? If you are?.........how do you explain that the turntable in the Timeline video features the Fat Bob platter with a massive weight and slows down alarmingly when the the stylus hits the record? Yet my TT-101 has a puny 2.0 Kg cast aluminium platter which has zero deviation in speed with one, two or three cartridges lowered onto the same record? All speed control is via the direct drive with servo control. This instantaneous speed control I believe, is far more critical than inertia? |
Dear Thuchan,
The Victor TT-101 is quartz controlled direct drive and automatically runs at a true 33.3rpm or 45rpm.
It has pitch adjustment in 6hz increments in both positive and negative direction.....but I never use this feature.
The servo control is bi-lateral........it works to speed up AND slow down.
Most other servos only are capable of speeding up and then rely on natural friction (or stylus drag) to be detected as 'too slow'.......for it to 'then 'speed up'.
This natural time delay is too slow with too much speed variance to really be critically effective IMHO?
Do you notice this slow-down when the stylus lands.........on your Nakamichi as well as your belt drives? |
Halcro,
do you have an inbuilt realigning control unit which brings the speed always to 33 or 45?
best @ fun only |
on all my TTs I experience a change in speed when the needle hits the record. Thuchan, On my TT-101 there is zero speed change when the cartridge hits the record. Even with the low compliance heavy tracking XV-1s and FR-7f. |
Tonywinsc -- excellent post!
I was thinking of the Nak TX 1000 as I contemplated your thoughts...Thuchan knows a thing or two -- about audio, I mean, hehe :-)
It would be fascinating to run those tests with the TX 1000 as the DUT.
Best regards,
Sam
|
Tonywinsc,
interesting what you experienced during your test measurements. on all my TTs I experience a change in speed when the needle hits the record. Regarding the different carts and weights of the headshells I usually adjust speed by my speed controllers. Belt drive not necessarily needs to be a disadvantage (thread). I usually measure my wow & flutter with a test tone of 3150 Hz and on the EMT by 5000 Hz (J60s).
You are so right on the Influence of the exact spindle position of the record. Most turntable designs don't refer to this issue. I know one design which does optimise the center of rotation - the Nakamichi TX 1000.
Best @ Fun Only |
A point was stumbled upon here, but no one followed through with the observation.
Halcro noted, "...you would have seen.......about half way through the video......where he drops the cartridge on the record and immediately.....the speed decreases?
And this is only the beginning of the record. Not a heavily modulated passage?
Can you imagine what happens with a really heavily modulated passage? And that turntable in the video has a very heavy platter."
Of interest to me isn't that the speed controller, assuming there was one, is inaccurate. It may be perfectly designed; we don't know. So, what basic principle would cause the speed drop? It isn't electronics, so it must be mechanical. If that is the case, all the electronics in the world cannot fix a fault because of a faulty design in the parts that make the turntable. My point is that inertia has to be addressed at the outset of a turntable's design, and that electronic speed control merely augments it. I strongly believe that 100% success is not found unless the all the pieces work in unison.
Sure, you can improve a turntable by adding an electronic speed control. The true nature of the recording is best exemplified when inertia is a major consideration to the basic design, in my honest opinion. |
