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Fun with vinyl measurements

JP

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I found a service manual for the SL1200mk7. It seems one should be able to measure speed related signals directly from pins 1-3 on the main PCB. Speed is apparently measured using some kind of Hall sensor. The manual does not really give any details on what the different pulse signals are.

View attachment 199344

Likely the hall sensors are for commutation. There's like a separate speed sensor, or there are in their other designs (GR, G(AE))
 
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Balle Clorin

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Mistracking is easy to hear as a a buzzing noise in one or both channels. Using Ortofons gukdeline to set anti scate ( increase anti-skate if buzz heard in RIGHT/outer channel and not on left(inner channer). By subtracing LEFT from RIGHT channer in REW( trace arithmetic A/B RIGHT/LEFT) i get a plot that shows elevated noise and distorion in the mistracking channel.
70UM and below sounds completely fine, 80um has slight hint of occasional mistrack in right channel, 90um clearly mistracking right channel, buzzing sound.
ATOC9ML/II in SME V. 1.5g/antiscate 1.5. ClearAudio Trackabiliy test record.

1651394174099.png
 
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Balle Clorin

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Can someone please comment and inform Fremer that the first track has a peak lavel +1.7 db higher and average level 2.1db higher than track 2
That means track 1 will be preferred,




For some strange reason I cannot register to AnalogPlanet or Stereophile so I cannot comment on the invalidity of this test.


1652603700860-png.817302

1652603737844-png.817303



Red curves higher than green
1652609761981.png
 
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anmpr1

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Can someone please comment and inform Fremer that the first track has a peak lavel +1.7 db higher and average level 2.1db higher than track 2
That means track 1 will be preferred,




For some strange reason I cannot register to AnalogPlanet or Stereophile so I cannot comment on the invalidity of this test.






Red curves higher than green
Yes. That was noted at the time of the test (by a DaveW3009). His comment, copied below, reports the fact. Reading through the comments it is interesting how reactions were mixed. Some liked it hot, and others cold. There are certainly good reasons to prefer a higher output MM cartridge to a lower, all other things being equal, which they typically are not.

It's strange when it comes to preferences. FWIW, I have a two A/T cartridges, both with the MicroLine stylus (440ML and 740ML). It is clear to me that both A/T are 'objectively' better than, for instance, my antique Denon DL103. But in many ways I prefer the Denon. I would not come here and argue that the Denon has better specs, lower distortion, and better groove tracing. I would not do anything so ridiculous. But when it comes to preference...
____________________________________________________
First , I normalized each file in Audacity. File two was about 1.7 dB below file one. I amplified 2 by 1.7 dB before listening.

Second, I have recorded a fair number of Organ performances and have heard even more live. File two sounded much more like an organ to my ears and the brass was more natural. I had to force myself to listen all the way through File 1.

It's easy to assume that the higher level file was the 2M Blue, which has the higher output. I hope not, since I have a 2M Blue.
 
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Balle Clorin

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Likely the hall sensors are for commutation. There's like a separate speed sensor, or there are in their other designs (GR, G(AE))
I would very much like to correct him, but as I said the registration to his site does work for me,,,

edit: do not know What happened here,
 
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IPunchCholla

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Just thought I'd throw these up here. I have no way to verify the accuracy, but the precision seems pretty good. Technics SL-QD33.

IMG_0154.PNG
 
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Balle Clorin

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Some measurments of L and R distortion with 0 antiskate. 1.5 and 3 on my AT-OC9ML/II 1.5gram VTF on SME V on a Michell Gyro SE.
Clearaudio trackability test record 333 Hz lateral mono track
Seems like the SME setting at 1.5 is quite OK. The anti-skate function is still fine on this arm that is 30 years old.
With no anti-skating the cartridge jumps out of the groove at 90um

1653129256395.png
 
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IPunchCholla

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Not exactly measurements, but I remembered I had this 12 year old cheap USB sound card that I could use to capture the music directly from the turntable (other than going through the sound card. TT>sound card>Mac mini> Adobe Audition. Here are snapshots of the first recording. First image shows the needle drop onto the LP. The second is that plus the first 30 seconds or so of the song. LP was on the platter for a couple days and I didn't brush it off before hand. It is a publicity pressing of of Amnesiac from Radiohead's recently released Kid A Mnesia. I need a better ADC.

Screen Shot 2022-05-22 at 5.22.33 PM.png


Screen Shot 2022-05-22 at 5.34.01 PM.png
 
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Balle Clorin

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I want to use Ultimate Analog test records IMD test to set VTA. But none om my software can give anything else than THD

the seems to be a program that can be useful for distortion analysis , but I cannot install it properly.

I install and start theexe file en installes,,but never get a pop up menu when staring program. I tried to follow the readme.file without understanding it--
MATLAB Compiler

1. Prerequisites for Deployment

* Verify the MATLAB Compiler Runtime (MCR) is installed and ensure you
have installed version 7.10.

* If the MCR is not installed, run MCRInstaller, located in:

C:\Program Files\MATLAB\R2009a\toolbox\compiler\deploy\win32\MCRInstaller.exe

For more information on the MCR Installer, see the MATLAB Compiler
documentation.

2. Files to Deploy and Package

Files to package for Standalone
================================
-DATK_Create.exe
-MCRInstaller.exe
-include when building component by selecting "include MCR" option
in deploytool
-This read-me file

3. Definitions

MCR - MATLAB Compiler uses the MATLAB Compiler Runtime (MCR),
which is a standalone set of shared libraries that enable the execution
of M-files. The MCR provides complete support for all features of
MATLAB without the MATLAB GUI. When you package and distribute an
application to users, you include supporting files generated by the
builder as well as the MATLAB Compiler Runtime (MCR). If necessary,
run MCRInstaller to install the correct version of the MCR. For more
information about the MCR, see the MATLAB Compiler documentation.



4. Appendix

A. On the target machine, add the MCR directory to the system path
specified by the target system's environment variable.


i. Locate the name of the environment variable to set, using the
table below:

Operating System Environment Variable
================ ====================
Windows PATH


ii. Set the path by doing one of the following:

NOTE: <mcr_root> is the directory where MCR is installed
on the target machine.

On Windows systems:

* Add the MCR directory to the environment variable by opening
a command prompt and issuing the DOS command:

set PATH=<mcr_root>\v710\runtime\win32;%PATH%

Alternately, for Windows, add the following pathname:
<mcr_root>\v710\runtime\win32
to the PATH environment variable, by doing the following:
1. Select the My Computer icon on your desktop.
2. Right-click the icon and select Properties from the menu.
3. Select the Advanced tab.
4. Click Environment Variables.



NOTE: On Windows, the environment variable syntax utilizes
backslashes (\), delimited by semi-colons (;).

I managed so set this, but still no success
1653574492242.png
 
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Balle Clorin

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I used up the demo period too early for other things (wow &flutter)

Tried something in Adobe audition(CoolEditPro)
1653672322193.png


Maybe more correct.. like this
1653719598261.png




It turns out REW can analyser Intermodulation distortion . In the RTA window I open the two-tone wav file and voila!
1653752436307.png

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Balle Clorin

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To enable IMD you need to first set the generator to Dual tone with the relevant duel-tone signal, and then open RTA window and then open Wav file og record it
1653763996402.png
 
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Balle Clorin

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I suddenly got increased speed variations when I checked the speed, and tried to sort it out. nothing helped but then I remembered the trick from Michell "put talcum on the belt" and voila! peak to peak speed variation reduced by 22%

1655926849734.png


I had to celebrate by putting on this record I bought 46 years ago...
 
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Risto_H

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Since this thread is also about RIAA measurements, I'll share my humble attempt mo design and create a RIAA that would not alter sound too much. I did one version in 1989 for myself that I also used for some years before I jumped into CD era. Fortunately I saved my vinyls and TT as back then (see: https://www.audiosciencereview.com/...solute-requirement.27123/page-18#post-1226654) and found them in good condition recently. I also thought about updating my old RIAA design to use modern parts and made RH RIAA 2.0. It had only either MM or MC input with only one gain setting and I decided to create a version with both MM and MC inputs. Additionally it has 4 gain settings to allow wide range of cartridges to be connected. Naturally there's options to adjust cartridge loading too.

Here's the frequency response deviation of the new prototype with MM input and 44 dB of gain selected. Please note that the vertical Y axis span is one dB so at least the RIAA correction is OK. The small jumps noticeable at low frequencies are cause by the QA403 analyzer and not the RIAA. As you can see, there's no rumble filter since that would destroy the response accuracy. Instead, I rely on the Shure + Denon arm damping and so far the combination works perfectly.

I have made some distortion and S/N ratio measurements too and will share them as well if there's any interest in such things. :)


Frequency response blue proto Serial# 000.png


Here's the PCB without box:
IMG_20210709_151912.jpg
 
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