Pitch Accuracy of Different Cutting Machines, can you help ?

[JuanPabloCuervo]

Ive heard many great things about Technics SP-02, Neumann VMS-82, Scully...

Easy way to measure Turntable accuracy...

Items Needed:
#1. The Ultimate Analogue Test LP. Track1 Side1.

Side 1 General Reference:
1Khz reference tone 7cm/s Mono, in phase (Lateral).
#2. PC.. XP or Vista
#3. decent soundcard with Stable Clock (low drift) & Low Noise ADC: RME hdsp9632, Lynx AES16, SonicCore, Echo, M-Audio, ESI, etc...
#4. AP Tuner 3.08 (The most accurate Pitch Analizer with Zoom)
#5. Camtasia Studio Screen Capture Software.
#6. Orbit Downloader. (optional but useful)

Here is an example:
Old Stock/unmoddified Technics SL-1200MK2-A
screen capture video with & without pop-up light, (turned ON & OFF several times.)
OFF gives "worse" results.

http://pwp.etb.net.co/triada82/pop-up-light.avi
http://www.youtube.com/watch?v=sI6i9Yst4Tg
P.S. AP Tuner has much more Vertical & Horizontal Zoom but for this test... was OK.

if video does not play...
#9. Cole2k Media Pack for Windows Media Player 9/10/11, you must activate TSCC video codec.
http://www.cole2k.net/codec-pack-advanced.html
or (easier) VLC Player
http://www.videolan.org/
***
#10. To measure sound card clock accuracy is needed:
1x software generated 1khz Sine Tone .wav 44.1khz 16Bits.
and a digital or analog loop back cable. OUT-->IN.

AP.com has a free Waveform generator software.
APx Waveform Generator Utility v2.5 (WfmGeneration.exe)

AP Tuner must be set to 44.1khz 16-Bits, But 96khz 24-Bits works better.
96khz 24-Bits must be activated in the Windows Vista / Recording & Playback Sound Properties in the Control Panel.
or the AP Tuner wont recognize the sample rate.[/img]

[dubcutter89]

Hmm, that video doesn't work, at least on my computer...

You are right the SP-02 and Neumann VMS-80 motors are great, but
about measuring i have a few concerns on your method:

1. The Ultimate Analogue Test LP is also just a record that was cut on a
lathe, and so you have all the wow/flutter of it in your results. Further it
is only usable for playback, but the more interesting thing would be
cutting, since the cutting process will produce much more braking force
than regular playback...

2. The decent soundcard. I'm not sure, but I think most soundcards use
the same clock for D/A as well as for A/D conversion. So if you check it
simply by connecting the in to the out you won't have any wow. Again
I'm not sure about this...

In my opinion it would be more easy to record a reference tone with
99.99 Hz (approx. 3 times the 33 Rpm) and simple look at the pattern
and check for irregularity...

Just my opinion...

[flozki]

yes
thats bullshit to use that record.
you also have all the pressing errors. not sure how well centered that record is.
the error of that particular lathe.

some side infos about plating, pressing errors.
i received the sample of our new 7inch reference level disc. and on this one the levels differ after plating and pressing around 0.3 db or so...
so many errors can sum up....

dubcutter89 is right. easiest is to cut the testtone.watch the groove under the microscope.
and the you see hill against hill.

if its still accurate after a few rounds.....
and it is accurate with a technics sp02....
then you have a nice turntable motor.

with old lyrecs especially when the capacitor is out of specs or cutting too deep you will see how it drifts away.....

and beside all that
what does it changeor tell us ?
this is the reality
industrial standart is neumann vms70 with lyrec motor.
very few with technics sp-02
a few vms80
scully depending on condition of bearings and belts....


would be interesting to see how that changed during last 30 years..
a good indication to everyones lathe.
to estimate its condition
but as a general value it says nothing new.

we can check datasheets

i am sure neumann gave wow&flutter values
as well as technics....
scully i dont know but i guess also.

[JuanPabloCuervo]

Hmm, that video doesn't work, at least on my computer...

install orbitdownloader:
http://www.orbitdownloader.com/
then VLC player
http://www.videolan.org/
or install the demo version of Camtasia Screen Capture Software:
http://www.techsmith.com/camtasia.asp
it does install the TSCC codec, and WindowsMediaPlayer can play the file.
or Cole2K media pack advanced, and activate the TSCC video codec.
http://www.cole2k.net/codec-pack-advanced.html

[JuanPabloCuervo]

i have a few concerns on your method:

1. The Ultimate Analogue Test LP is also just a record that was cut on a
lathe, and so you have all the wow/flutter of it in your results. Further it
is only usable for playback, but the more interesting thing would be
cutting, since the cutting process will produce much more braking force
than regular playback...

yes, drift & jitter its accumulative, same happens in a different scale with AD&DA converters.

that means: the results are a bit better than they look.
for example: if the Neumann VMS80 has 1/100th of a note precision...
and the Stock 30 year old Technics SL-1200MK2-A measures 1/4 = 25cents, Minus Neuman VMS80 1/100 = 1 cent
24-1= 24cents.

1/100 is 1 cent.
1/50 is 2 cents.
1/20 is 5 cents of Note.
1/10 is 10Cents.
1/5 is 20 cents.
1/4 is 25 cents of a Note.

BUT SP-02 Specs say it has 1/10.000th precision.
so if technics measures 1/4 its 1/4 - 1/10.000

The test can also be done with RANE Serato Scratch CV02...
it has a constant 1Khz tone also, not sine wave, but close enough.

the CV02 was done with a SP-02, but Drift is higher than Ultimate Analogue Test LP. CV02 is 0.0026% max.

Native Instruments Traktor Scratch Vinyl does have a 2Khz tone, but higher tone has less drift = does not work for this test, unless the Cutting Machines are used at Half Speed for playback.

looking the Cutting Lathe machines like a Playback turntable...
just want to know the Pitch Precision of the High End Cutting Machines...
if used just like a turntable.

Apples vs. Apples
Apless vs. Apless
Torque is another story... but would be also interesting to measure.

that test is a bit more complex but can be done.

2. The decent soundcard. I'm not sure, but I think most soundcards use
the same clock for D/A as well as for A/D conversion. So if you check it
simply by connecting the in to the out you won't have any wow. Again
I'm not sure about this...

44.1khz should be a 2.8Mhz signal.. but not all clocks are made the same..
sadly clocks are the most unstable thing in the universe..
they are affected by temperature, altitude, vibrations, element used, purity of the element, the purity of the electric signal driving it, etc...

so... if you use an AES11-2003 Grade 1 Clock...
it will have drift under 100Hz, but will measure perfect over it. <<1PPM

with old lyrecs especially when the capacitor is out of specs or cutting too deep you will see how it drifts away.....

I just want to measure the Cutting Lathe Machines as a Playback Turntable, first, to have a base/reference level.

and beside all that
what does it changeor tell us ?
this is the reality
industrial standart is neumann vms70 with lyrec motor.
very few with technics sp-02
a few vms80
scully depending on condition of bearings and belts....

i just want to see if SP-02 Specs are True.
also how does compare to stock VMS-80 / 82.

would be interesting to see how that changed during last 30 years..
a good indication to everyones lathe.
to estimate its condition
but as a general value it says nothing new.

we can check datasheets

i am sure neumann gave wow&flutter values
as well as technics....
scully i dont know but i guess also.

Would be interesting to see the diferences between different Cutting Machines from same or different model/manufacturer.

Technics SP-02 Specs are incredible... i just want test them.
PDF say it has 0.001% precision, but does not tell at what frequency... or how its measured.

i guess its measured at the circuit with an osciloscope, but with a record ?

[markrob]

Hi,

I really don't get why you are so concered with absolute pitch accuracy. Its really hard to design a crystal oscillator that is off much more than .1%. If the motor speed is controlled by a quartz locked oscillator, than I think you are good. If you need better accuracy, then buy or rent a high accuracy lab standard frequency counter with a timebase that's been certified. Find the test point on the motor servo that is the measuring point for speed and take a reading. .1% accuracy represents about 2 cents pitch error. That's good enough for me. If I look at my guitar funny it goes out of tune more than that.

Using a record and sound card to do this is flawed in many ways. You don't even know the accuracy of the generator used to cut the 1Khz tone on the recording, let alone the lathe and turntable speeds. Its probably ok for a quick check.

The more important spec is wow, flutter, and other timbase errors. I don't know of any software that runs on a standard desktop computer that can do this test, but its certainly possible to write. I'm sure the jitter specs of the worst sound card are way better than any motor. So you should be able to get meaningful numbers. A simple tuning program or FFT spectrum is not going to cut it for this measurment. Again there is test equipment available to perform these measurments.

Trying to measure to the level of accuracy you are asking for requires serious test equipment and carefull attention to detail to get valid results.

Mark

[opcode66]

Hmm, that video doesn't work, at least on my computer...

install orbitdownloader:
http://www.orbitdownloader.com/
then VLC player
http://www.videolan.org/
or install the demo version of Camtasia Screen Capture Software:
http://www.techsmith.com/camtasia.asp
it does install the TSCC codec, and WindowsMediaPlayer can play the file.
or Cole2K media pack advanced, and activate the TSCC video codec.
http://www.cole2k.net/codec-pack-advanced.html

How about re-encoding your video in a common codec. To expect people load software or codecs to play a video is not cool. Not going to happen. Even just uploading to You Tube would work....

[opcode66]

Hey, how about instead of measuring a useless statistic in a flawed way, we all try to figure out a new motor control system and motor?

[JuanPabloCuervo]

Hi,

I really don't get why you are so concered with absolute pitch accuracy. Its really hard to design a crystal oscillator that is off much more than .1%. If the motor speed is controlled by a quartz locked oscillator, than I think you are good. If you need better accuracy, then buy or rent a high accuracy lab standard frequency counter with a timebase that's been certified. Find the test point on the motor servo that is the measuring point for speed and take a reading. .1% accuracy represents about 2 cents pitch error. That's good enough for me. If I look at my guitar funny it goes out of tune more than that.

Using a record and sound card to do this is flawed in many ways. You don't even know the accuracy of the generator used to cut the 1Khz tone on the recording, let alone the lathe and turntable speeds. Its probably ok for a quick check.

The more important spec is wow, flutter, and other timbase errors. I don't know of any software that runs on a standard desktop computer that can do this test, but its certainly possible to write. I'm sure the jitter specs of the worst sound card are way better than any motor. So you should be able to get meaningful numbers. A simple tuning program or FFT spectrum is not going to cut it for this measurment. Again there is test equipment available to perform these measurments.

Trying to measure to the level of accuracy you are asking for requires serious test equipment and carefull attention to detail to get valid results.

Mark

jitter is different than pitch drift.
but...
you can send the dub plates to my address in Miami FL
or the .wav files to my ftp.
i would analize them with my equipment and upload results here.

[JuanPabloCuervo]

How about re-encoding your video in a common codec. To expect people load software or codecs to play a video is not cool. Not going to happen. Even just uploading to You Tube would work....

TSCC is the best codec for Screen Capture video.
other files would be larger... or less quality.
its a real 30fps HD Screen Capture...

anyway.. ill try YouTube HD.
http://www.youtube.com/watch?v=sI6i9Yst4Tg
a Screen Capture video on YouTube,

The original File Týpe gives the illusion, like if you were doing the test your self in your pc, or here with my equipment, you dont get distracted thinking about the codec when looking the video...

[JuanPabloCuervo]

Hi,

I really don't get why you are so concered with absolute pitch accuracy.

Why bother being the best? or the fastest? the Strongest? or the most precise?

[blacknwhite]

I just want to measure the Cutting Lathe Machines as a Playback Turntable

Forgive my curiosity, but.... why?

Seems the only time you would ever, Ever care about the accuracy of a cutting turntable, is when cutting... Ever...

As others have mentioned, measuring playback without cutting seems like a pointless waste of time, since it gives no indication what-so-ever about how the turntable will perform while cutting.... A particular lathe may perform "relatively worst" without any resistance (slightly more miniscule errors/fluctuations) but same turntable may perform relatively BEST under cutting (best torque).

So the playback test has nothing to do with the Purpose of the lathe turntable, and doesn't show which turntable is better or worse for cutting...

Unless you're shopping around for an audiophile playback turntable

[Aussie0zborn]

To solve all these problems, just use the Rane PI14 when cutting. You can add a little bit of "this" and a little bit of "that" to compensate for all these problems. The stereo panning is excellent - with one knob you can pan from "here" to "there" and if you get lost along the way you can hit the "back again" button. Way too many features to list... full specs at http://www.rane.com/pi14.html

[JuanPabloCuervo]

I just want to measure the Cutting Lathe Machines as a Playback Turntable

Forgive my curiosity, but.... why?

Unless you're shopping around for an audiophile playback turntable

[opcode66]

To solve all these problems, just use the Rane PI14 when cutting. You can add a little bit of "this" and a little bit of "that" to compensate for all these problems. The stereo panning is excellent - with one knob you can pan from "here" to "there" and if you get lost along the way you can hit the "back again" button. Way too many features to list... check the spec sheet http://www.rane.com/pdf/pi14dat.pdf

The best response to a rediculous post!!!!!!!!!



Dude, I totally need a Glory switch on some of my gear...

[blacknwhite]

I just want to measure the Cutting Lathe Machines as a Playback Turntable

Forgive my curiosity, but.... why?

Unless you're shopping around for an audiophile playback turntable

Theres your answer folks...

NOW the thread makes perfect sense.

It is best to say up front what your intention is, so that folks won't be wondering what in the world you're trying to accomplish

[JuanPabloCuervo]

Dude, I totally need a Glory switch ...

Agree.

[mossboss]

Followed this with a high level of curiosity wondering what is this all about
I suspected some kind of audiophilia there
It would be his luck to fall in the grips of our "pitch Experts" here
Even though a rediculous post there are some good bits there as well
And that is what is all about finding the answers
Cheers

[andybee]

[Factorcuts]

Hey, how about instead of measuring a useless statistic in a flawed way, we all try to figure out a new motor control system and motor?

I totally agree...why not build a whole new turntable and pitch/depth control, designed with todays technology, that is meant to be used for cutting? Probably a pretty expensive endeavour, but a very worthy one!