Dear friends: I'm really surprised on almost all your answers on the overall subject.
Why surprised?, if there is true that some of us has no perfect pitch and can't detect " minute/tiny " speed deviations it is true too that other persons are way better in this regard and very sensitive about.
But, why that " no perfect pitch " or " I can't hear that minute deviations " or even " I don't care what I can't hear " where all these kind of opiniuons are only excuses to " protect " the TT already owned.
I'm not a designer of TT but if someday I take that road my very first and main target will be: no excuse, " perfect pitch " design: period.
If the customers can or can not detect it is does not matters, if during the recording proccess ( including those " great " R2R units. ) does not existed that " perfect pitch " it does not matters either even if the customers do not cares about IMHO any TT designer must look for that " perfect pitch " even absolute speed.
Dear audiophiles, please don't take it away the TT designers responsability. A TT exist because the LP needs to spin for we can listen and has to spin always at 331/3rpm or 45rpm: period.
We as a customers IMHO have to ask for excellence design level and not where almost everyone belongs: mediocrity/average level like the excuses that we don't have perfect pitch or that the electrical supply at home is non-adequate or that today is alittle " cold ".
How our hobby could improve when we are not asking for " more " for excellence but given reasons for the audio device designers does not cares about or at least does not cares enough about.
Halcro experiences with his Victor DD is not alone but several of us already experienced the same with some one of those DD vintage TT samples: exist a difference a difference that any one could hear.
Of course that if I own one of those BD dinosaur/mammoth we " accept " those minute/tiny speed deviations with no other explanation that " I can't hear " even if the timeline put in evidence the problem in our BD units.
Years ago and before the Timeline was in the market I posted several times that with heavy mass BD TT did not exist speed deviations due to stylus friction. Not easy to detect it but this fact does not means that I ask to TT designers : perfect pitch.
Our analog hobby is maybe the most imperfect reproduction medium where IMHO we have to take care in any single and " simple " stage where the cartridge signal must pass and where always suffer a degradation. As lower degradation on each one of those steps/links the cartridge signal suffer as better will be the sound that comes from our speakers and the higher the music enjoyment.
TT perfect pitch is one of those steps/links that degrade the cartridge signal even if we can't detect it or if " we don't care ".
As Teres pointed out: there is land for improvement about TT speed stability.
In this specific regard the DD experiences on many of us already showed that are a head to the BD ones.
Regards and enjoy the music,
R. |
Dear Frogman: We have to take care about. Unfortunately no one of us have control over the recording proccess where happen " terrible " things that " disturb " ( for say the least ) not only what you are pointed out but the " original " essence of the music.
We can't restore what already were degraded on that recording proccess but at least we can take care that that degradation be the lowest one and certainly the overall TT speed subject is vita. As I posted:
+++++++++ A TT exist because the LP needs to spin for we can listen it and has to spin always at 33.1/3rpm or 45rpm : period. " +++++ NO excuses here.
Regards and enjoy the music,
R. |
Dear Dougdeacon: ++++ " concluding that idler wheel/rim drive designs are inherently better than BD's would be going too far. We've had such a design in our system, made by Teres, and it was audibly inferior to our carefully worked out BD. Implementation is always critical and individual cases may trump general rules. " +++++
what do you mean with this? that Paul and you listened to two TTs bis a bis with similar tonearm/cartridges at the same sessions/comparisons?
I know both of you and I have no doubt on what you posted it is only for I can understand how that comparison was made.
In the other side, implementation as you said is critical on any audio device design or on tests as the one you mentioned.
Regards and enjoy the music,
R. |
Dear Syntax: Well Halcro has a wider black hole in the wall, right behind the TT. This TT is a DD 400.00 Victor TT.
So not big deal what you are showing against the humble Victor or my Denon one.
It is not here at speed accuracy/stability where belongs the " secret " for a top quality level that you till today can't even imagine could exist.
Have fun.
Regards and enjoy the music,
R. |
Syntax: In the other side why so that big deal with the thread when for so many years it was and is used. My Acoustic Signature TTs only accept thread drive and in my RX5000 I only use thread and hundreds of TTs out there are using thread for drive.
Maybe the thread drive is the new toy for you and as a rockie in that regards you are excited , come down you have to learn to much about.
Regards and enjoy the music,
R. |
Dear halcro: 1.5K?, ridiculous against that RX5000 that needs all that stuff to spin on target.
600.00 for my Denon and 250.00 for a Technics 1200 or 500.00 for the SP-10.
As I said: no big deal.
regards and enjoy the music,
R. |
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 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. |
Dear Dertonarm: Like with the Wave Kinetics and Onedof new TT designs now you follow dimish every new TT design like this one Air Force One.
Why in one way or the other do you want to dimish the other designers efforts even when you never heard those new designs?
I can't see any other TT designer that already dimished your coming TT?
We customers need alternatives and with out real and precise foundation why comment/dimish/attack a new TT design what/that you never heard it and never has on hand?
I know that your design is wrong but I don't care about because is your design not mine.
Regards and enjoy the music,
R. |
Dear friends: Do you think here could exist speed accuracy?
https://picasaweb.google.com/hfeiner/TWOTURNTABLES?authkey=Gv1sRgCOy02-j1puykKA#5678170499062229282
that's is a JC/TH/H contribution.
Regards and enjoy the music,
R. |
Dear Dertonarm/Syntax: +++++ " However IMHO speed accuracy is a basic - if not THE basic - request to ANY turntable.
As said before - this is a conditio sine qua non for any turntable.
As this is a basic feature, it is not contributing to the sound quality.... " +++++
IMHO that statement is plain wrong: it is as to say that a phono stage " basic request " is no RIAA deviation/gain with no noise or in an amplifier 0.01 ohms output impedance or in a cartridge flat ( cero deviation ) frequency response or whatever with any kind of audio items.
The premise that those are " basic request " audio device in the designs does not means the audio product already achieved only because are " main request ".
In our imperfect audio world there are almost none of that " main requests " in any design that fulfil those main requests.
So to assume that main requests are all there is IMHO a wrong assumption.
TT's is only an example both of you can take any audio item and you will and know that the " majority " does not fulfil even those main requests. Mediocrity is the name of the game with a few exceptions.
Now, speed is only one factor in the whole TT design and in the final quality level performance.
We will see how good the " main request " on a TT: neutral/accurate can be match by all those new designs including yours.
Regards and enjoy the music,
R. |
Dear Lewm: Yes, they did indeed. These are exerpts from a Sony research in 1975:
++++++++++++++++++++++++++++++++++++++++++++++++++++
Ordinary Motor Servo System
The design object of a turntable motor servo-control system is to
have the least amount of change in rotational speed when the motor
is subjected to changes. Load conditions, such as application of
stylus pressure on the record and the change in fractional resistance
between stylus and record groove. Fig. I shows the static characteristics
of the servo system.
When the motor load torque is to and the supply voltage is Vo, the
angular velocity is Po. If the load increases to tl, the angular
frequency goes down to Pi provided that the supply voltage is kept
at Vo. In this case, th8 amount of change in angular velocity per
unit change of load is as shown below.
6P Po-P_ I
KT- a_- - ?,-7o - Do I-o.
Do=Fluid resistance
In order to bring the angular velocity back as close as possible to
Po, the supply voltage must be increased when the angular frequency
is lowered from Po to Pl' The amount of change in angular velocity
of the motor per unit of supply voltage, Ky, is shown as follows:
81_ KT
Kv=_,V - 0o I-b
KT = Cons'i'anf of 'torque .generefion
The amount of change in voltage per unit angular velocity, K, is expressed
as follows:
aV
K- FC
AW
_p in FiE. 2 is the amount of change in angular velocity after the
servo system has stabilized and is shown as follows:
Ap = I+K Kv
_7 = chanqein Icedtorque
i + KKv in the preceding equation Is called the loop gain. From the
equation 1-a and 1-b the following is obtained:
f
P Do
---- I-C
Ay I+KKV
Thls shows that curve S In Fig. I which indicates the amount of change
In angular velocity after the serve has stabilized, is improved when
multipled by the loop gain over the change in angular velocity before
the serve is stabilized. Above, we discussed the function of the serve
system with a change in load torque under DC conditions. In the case
of a change In load torque under AC conditions, the relation among various
parameters in shown in Fig. 3.
The dotted lines in Fig. 3 show the characteristics of disturbance suppression
by the moment of inertia of the motor rotor and turntable.
The solid line shows the characteristics after the serve is stabilized.
Fig. 3 is also expressed In the following equation:
Po I -.f
glo= (I+KKv) j
I.
z_P(Jl) Do
A7 (,.Pt,) - I,KKv t-9
when J_ ¢ d'_co
Therefore,
aPfJ_)
I-h
/',7'(_'t,) J-d"bo
This indicates that in order to obtain higher suppression of external
disturbance, it is necessary to make the moment of inertia of motor
rotor and turntable as well as the angular velocity response of serve
system larger. For example, under the following conditions:
,.,T=ZOO(§.cTn. seci), J_o --Z/-(X lO (red/acc)
Stylus point from spindle = 15(cra)
Stylus pressure = 3f§)
Coefficienf of frichon, xz =0.4
_Y = I_ x 3 ×O.Z..=I-18 (9 .cra)
The amount of change in angular velocity of the motor spindle dP is,
therefore, expressed as follows:
2
Ap = J_L_ ' AZ = ZOOx Z 7_x IO X 18 = I,z+33XIO -3 (md/sec)
· = O.OI37(rpm)
This change in the standard speed of 33 1/3 rpm in percentage,_, is:
/
aP O.OI37
?_ ---- _P_3__- X IOO --- lOC X IOO = O,Oql (%)
3
Phase-locked Motor Servo System With Quartz Generator
As discussed above, conventional servo system requires detection in change
of angular velocity for compensation in changes of speed. Therefore, unless
the moment of inertia in the mechanical system is infinite or the
angular velocity of servo response is infinite, it is impossible to avoid
changes in speed totally. Increase in the moment of inertia will result
in shorter life of the motor/turntable bearings and slower start-up time.
Increase in angular velocity of servo response has also its limitations.
The phase-locked servo system utilizes the prinipal that if a change in
angular velocity is converted to a change in phase, the conversion constant
becomes infinite at DC. The change in angular velocity P(t) is expressed
as follows:
Pit) =A PcosJ1t &p: arnountchangedin
angular velocity
The change in phase f8 (rD;n this case is-
_(:t)=fPtt)dt- AP sin Zlz / ./ _b
Therefore, the transfer function H (_) is =
Therefore,¢h¢¢rans_r fu_ffion H(_) is:
H(g) = -p-=(t) ..I... 2-_
Pit) jJ_
The preceding equation 2-a indicates that when a change in angular
velocity (_) is zero (or DC), the conversion gain becomes infinite
and the phase is always 90° behind regardless of angular velocity.
The transfer function, HT (_-) is the change between angular velocity,
and voltage is expressed as follows: .
Ka
Hr (Z1,)= K,_ H(_%)=
K_: Cons-Cainntconvertingchange
inphase intochange in voltage
Fig. 4 shows the block diagram of the serve system with HT _ in the
serve loop, and Fig. 5 shows its disturbanee suppression characteristics.
In Fig. 5 the dotted lines show the disturbance suppression
3
characteristics of the moment of inertia in the mechanical system.
The solid line shows suppression of characteristic after the velocity
detection servo is stabilized. The broken line shows the characteristics
of servo system including the phase comparator system. As shown,
compared to the system only with velocity detection, the phase comparator
system improves the disturbance suppression characteristics when
the torque disturbance angle frequency is belowS; and when there is
no disturbance _.=O), the change in turntable angular velocity_p becomes
zero, or in perfect equilibrium. If there is an error in the reference
itself, to which the angular velocity of the motor is compared,
this will of course result in an error in motor speed. In the case of
the Sony PS-8750, a quartz generator is used as the reference source.
Since the speed error of the motor in this case is equal to that of the
generator, it is kept to below 0.003%.
The effect of the stylus pressure and friction between the stylus and
record groove is shown in Figures 6-1 and 6-2. Fig. 6-1 shows that
with "velocity only" servo systems a two-gram stylus pressure on the
outer grooves results in approximately 0.02% slow down inturntable
speed in addition to the speed fluctuations of about 0.014% caused by
the audio signal modulation in the record grooves. Fig. 6-2 shows
speed stability of the phase-locked servo system. As it is shown,
there is little effect from stylus pressure and the change in friction
between the stylus and grooves on the turntable speed. The frequency
of the external disturbance stays mostly below 1Hz. Therefore, as shown
in Fig. 5 it is suppressed very effectively with the phase-locked servo
system, j_In the PS-8750Jcase, the phase-locked servo responds below 1.4
Hz (fc =_-_= 1.4 (Hz). At around 0.07Hz where most of the disturbance is
found the suppression is approximately 20 times greater than that of
the "velocity only" servo system. If the same effect is to be obtained
with the servo system without a phase comparator, 20 times more moment
of inertia is required in the mechanical system.
++++++++++++++++++++++++++++++++++++++++++++++++++++++
Denon use/used that PLL system as other manufacturers.
Regards and enjoy the music,
R. |
Dear Decibell: Please email me.
Regards and enjoy the music,
R. |
hi there-------------------------------testing only. |
Dear Halcro: As Dover I'm using thread drive for all the years I can remember either the MS I owned till today and my Acoustic Signature ones.
What is weird is that only " today " many people is discovering when the option always been there.
I don't know you but even with a thread the DD ones performs overall better.
Btw, what Lewm posted and that M.Lavigne refered on other related thread and my own post ( not so specific as Lewm one. ) about that the Timeline is not accurate/perfect as we all are thinking finally there is a " light " that tell us on that non accurate device that already brought some TT owners to a " suicide ".
This could tell us that we have to analize this type of TT subject more carefully that what we are doing till today.
Maybe Mr. Sutherland can comes here to explain the overall Timeline design and to confirm or not that 0.00018 discrepancy.
Regards and enjoy the music,
R. |
Dear Dover: About thread/high mass platter my AS are not really high mass ( I think are around 12-14kg ) and works really fine with thread and the RX500 performs good as well. Yes, maybe different TT design works different but I can't see very clear the whole reasons about if there are some reasons.
Regards and enjoy the music,
R. |
Dear Halcro: You always can try a different thread's build material and see/hear what happen.
regards and enjoy the music,
R. |
Dear Halcro: A friend of mine brought his Timeline with him at my place two-trhee days ago and we made some tests in my Denon DP75 and both Acoustic Signature's.
We found out that DP-75 was and is right on target but the AS were off even that through a strobe showed were fine. So I dialed through the Timeline, something that's very simple task on the AS motor controler through trimpots. We tested with and with out cartridge playback and things were the same: non detected speed fluctuation because stylus drag ( two on the Denon. )
Before the test I was a little " worried " about the Denon becuase has no external pitch control as the DP-80, fortunately runs splendid.
Now, through the AS and before we aligned with the Timeline we heard three specific tracks : before and after correction and we were unaware to hear differences even that we " want " it and looking for.
Seems to me that depend how wide the speed is off we can or we can't hear differences and obviously depend on our skills/knowledge and system.
Btw, as Lewm posted every TT has a speed controler by design because is the way the TT speed was set up from factory. The DP-75 certainly has it internally as the Technics ones and every other TT.
Yes, I agree with some of you that posted that the primary target on a TT design is speed accuracy and speed stability, with out these there is no TT.
No, I don't think, for that price, that the Timeline is a must to have especially because with the AS we can't detect any differences but as you in other TT set ups things could be different and the Timeline is a necessary tool. Good trained ears and high knowledge audio/music level can tell you the whole " history " maybe better than the Timeline.
Anyway, worth those experiences I had.
Regards and enjoy the music,
R. |
Dear Dev: Seems to me that a high cost not only in a TT bearing has to see not only with its design and tolerance level but with the quantity you ordered and obviously marketing.
If that same item is builded in 10,000 pzs. instead 50 you will see the big big difference in price.
During our " long " tonearm design time we learnedd many things about and if you can and with some items/parts sometimes is better to build it at home by your self.
Regards and enjoy the music,
R. |
Dear Halcro: No doubt Timeline is a great tool for now. I think that the main subject around it is not only that we learn more about our each one TTs and its right set up but that today TT designers use the Timeline ( or similar tool. ) as a important part on its design and development of a TT.
That we can know that this or that TT has a " failure " about can't help enough, what can help to each one of us as customers is that today and future TT designs could come with the Timeline " certification ".
At the end that " certification " is or should be IMHO a TT's designer target not ours.
Btw, Halcro the stock MS TTs are not good enough about speed and speed stability, its motor controler are deficient about . Years ago in my unit and other units we have to make changes in there to improve this TT main desirable characteristic. IMHO and with today standards MS units are only an average ones.
Anyway, Timeline is here to stay: good.
Regards and enjoy the music,
R. |
